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Sample records for leptin-deficient mice improves

  1. Leptin Increases Striatal Dopamine D2 Receptor Binding in Leptin-Deficient Obese (ob/ob) Mice

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    Pfaffly, J.; Michaelides, M.; Wang, G-J.; Pessin, J.E.; Volkow, N.D.; Thanos, P.K.

    2010-06-01

    Peripheral and central leptin administration have been shown to mediate central dopamine (DA) signaling. Leptin-receptor deficient rodents show decreased DA D2 receptor (D2R) binding in striatum and unique DA profiles compared to controls. Leptin-deficient mice show increased DA activity in reward-related brain regions. The objective of this study was to examine whether basal D2R-binding differences contribute to the phenotypic behaviors of leptin-deficient ob/ob mice, and whether D2R binding is altered in response to peripheral leptin treatment in these mice. Leptin decreased body weight, food intake, and plasma insulin concentration in ob/ob mice but not in wild-type mice. Basal striatal D2R binding (measured with autoradiography [{sup 3}H] spiperone) did not differ between ob/ob and wild-type mice but the response to leptin did. In wild-type mice, leptin decreased striatal D2R binding, whereas, in ob/ob mice, leptin increased D2R binding. Our findings provide further evidence that leptin modulates D2R expression in striatum and that these effects are genotype/phenotype dependent.

  2. Abalation of Ghrelin receptor in leptin-deficient mice has paradoxical effects on glucose homeostasis compared to Ghrelin-abalated Leptin-deficient mice

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    Ghrelin is produced predominantly in stomach and is known to be the endogenous ligand of the growth hormone secretagogue receptor (GHSR). Ghrelin is a GH stimulator and an orexigenic hormone. In contrast, leptin is an anorexic hormone, and leptin-deficient ob/ob mice are obese and diabetic. To study...

  3. Impaired clearance of influenza A virus in obese, leptin receptor deficient mice is independent of leptin signaling in the lung epithelium and macrophages.

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    Kathryn A Radigan

    Full Text Available During the recent H1N1 outbreak, obese patients had worsened lung injury and increased mortality. We used a murine model of influenza A pneumonia to test the hypothesis that leptin receptor deficiency might explain the enhanced mortality in obese patients.We infected wild-type, obese mice globally deficient in the leptin receptor (db/db and non-obese mice with tissue specific deletion of the leptin receptor in the lung epithelium (SPC-Cre/LepR fl/fl or macrophages and alveolar type II cells (LysM-Cre/Lepr fl/fl with influenza A virus (A/WSN/33 [H1N1] (500 and 1500 pfu/mouse and measured mortality, viral clearance and several markers of lung injury severity.The clearance of influenza A virus from the lungs of mice was impaired in obese mice globally deficient in the leptin receptor (db/db compared to normal weight wild-type mice. In contrast, non-obese, SP-C-Cre+/+/LepR fl/fl and LysM-Cre+/+/LepR fl/fl had improved viral clearance after influenza A infection. In obese mice, mortality was increased compared with wild-type mice, while the SP-C-Cre+/+/LepR fl/fl and LysM-Cre+/+/LepR fl/fl mice exhibited improved survival.Global loss of the leptin receptor results in reduced viral clearance and worse outcomes following influenza A infection. These findings are not the result of the loss of leptin signaling in lung epithelial cells or macrophages. Our results suggest that factors associated with obesity or with leptin signaling in non-myeloid populations such as natural killer and T cells may be associated with worsened outcomes following influenza A infection.

  4. Loss of stearoyl-CoA desaturase 1 rescues cardiac function in obese leptin-deficient mice.

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    Dobrzyn, Pawel; Dobrzyn, Agnieszka; Miyazaki, Makoto; Ntambi, James M

    2010-08-01

    The heart of leptin-deficient ob/ob mice is characterized by pathologic left ventricular hypertrophy along with elevated triglyceride (TG) content, increased stearoyl-CoA desaturase (SCD) activity, and increased myocyte apoptosis. In the present study, using an ob/ob;SCD1(-/-) mouse model, we tested the hypothesis that lack of SCD1 could improve steatosis and left ventricle (LV) function in leptin deficiency. We show that disruption of the SCD1 gene improves cardiac function in ob/ob mice by correcting systolic and diastolic dysfunction without affecting levels of plasma TG and FFA. The improvement is associated with reduced expression of genes involved in FA transport and lipid synthesis in the heart, as well as reduction in cardiac FFA, diacylglycerol, TG, and ceramide levels. The rate of FA beta-oxidation is also significantly lower in the heart of ob/ob;SCD1(-/-) mice compared with ob/ob controls. Moreover, SCD1 deficiency reduces cardiac apoptosis in ob/ob mice due to increased expression of antiapoptotic factor Bcl-2 and inhibition of inducible nitric oxide synthase and caspase-3 activities. Reduction in myocardial lipid accumulation and inhibition of apoptosis appear to be one of the main mechanisms responsible for improved LV function in ob/ob mice caused by SCD1 deficiency.

  5. Leptin rapidly improves glucose homeostasis in obese mice by increasing hypothalamic insulin sensitivity.

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    Koch, Christiane; Augustine, Rachael A; Steger, Juliane; Ganjam, Goutham K; Benzler, Jonas; Pracht, Corinna; Lowe, Chrishanthi; Schwartz, Michael W; Shepherd, Peter R; Anderson, Greg M; Grattan, David R; Tups, Alexander

    2010-12-01

    Obesity is associated with resistance to the actions of both leptin and insulin via mechanisms that remain incompletely understood. To investigate whether leptin resistance per se contributes to insulin resistance and impaired glucose homeostasis, we investigated the effect of acute leptin administration on glucose homeostasis in normal as well as leptin- or leptin receptor-deficient mice. In hyperglycemic, leptin-deficient Lep(ob/ob) mice, leptin acutely and potently improved glucose metabolism, before any change of body fat mass, via a mechanism involving the p110α and β isoforms of phosphatidylinositol-3-kinase (PI3K). Unlike insulin, however, the anti-diabetic effect of leptin occurred independently of phospho-AKT, a major downstream target of PI3K, and instead involved enhanced sensitivity of the hypothalamus to insulin action upstream of PI3K, through modulation of IRS1 (insulin receptor substrate 1) phosphorylation. These data suggest that leptin resistance, as occurs in obesity, reduces the hypothalamic response to insulin and thereby impairs peripheral glucose homeostasis, contributing to the development of type 2 diabetes.

  6. Transgenic neuronal expression of proopiomelanocortin attenuates hyperphagic response to fasting and reverses metabolic impairments in leptin-deficient obese mice.

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    Mizuno, Tooru M; Kelley, Kevin A; Pasinetti, Giulio M; Roberts, James L; Mobbs, Charles V

    2003-11-01

    Hypothalamic proopiomelanocortin (POMC) gene expression is reduced in many forms of obesity and diabetes, particularly in those attributable to deficiencies in leptin or its receptor. To assess the functional significance of POMC in mediating metabolic phenotypes associated with leptin deficiency, leptin-deficient mice bearing a transgene expressing the POMC gene under control of the neuron-specific enolase promoter were produced. The POMC transgene attenuated fasting-induced hyperphagia in wild-type mice. Furthermore, the POMC transgene partially reversed obesity, hyperphagia, and hypothermia and effectively normalized hyperglycemia, glucosuria, glucose intolerance, and insulin resistance in leptin-deficient mice. Effects of the POMC transgene on glucose homeostasis were independent of the partial correction of hyperphagia and obesity. Furthermore, the POMC transgene normalized the profile of hepatic and adipose gene expression associated with gluconeogenesis, glucose output, and insulin sensitivity. These results indicate that central POMC is a key modulator of glucose homeostasis and that agonists of POMC products may provide effective therapy in treating impairments in glucose homeostasis when hypothalamic POMC expression is reduced, as occurs with leptin deficiency, hypothalamic damage, and aging.

  7. Protection against high-fat diet-induced obesity in Helz2-deficient male mice due to enhanced expression of hepatic leptin receptor.

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    Yoshino, Satoshi; Satoh, Tetsurou; Yamada, Masanobu; Hashimoto, Koshi; Tomaru, Takuya; Katano-Toki, Akiko; Kakizaki, Satoru; Okada, Shuichi; Shimizu, Hiroyuki; Ozawa, Atsushi; Tuchiya, Takafumi; Ikota, Hayato; Nakazato, Yoichi; Mori, Munemasa; Matozaki, Takashi; Sasaki, Tsutomu; Kitamura, Tadahiro; Mori, Masatomo

    2014-09-01

    Obesity arises from impaired energy balance, which is centrally coordinated by leptin through activation of the long form of leptin receptor (Leprb). Obesity causes central leptin resistance. However, whether enhanced peripheral leptin sensitivity could overcome central leptin resistance remains obscure. A peripheral metabolic organ targeted by leptin is the liver, with low Leprb expression. We here show that mice fed a high-fat diet (HFD) and obese patients with hepatosteatosis exhibit increased expression of hepatic helicase with zinc finger 2, a transcriptional coactivator (Helz2), which functions as a transcriptional coregulator of several nuclear receptors, including peroxisome proliferator-activated receptor γ in vitro. To explore the physiological importance of Helz2, we generated Helz2-deficient mice and analyzed their metabolic phenotypes. Helz2-deficient mice showing hyperleptinemia associated with central leptin resistance were protected against HFD-induced obesity and had significantly up-regulated hepatic Leprb expression. Helz2 deficiency and adenovirus-mediated liver-specific exogenous Leprb overexpression in wild-type mice significantly stimulated hepatic AMP-activated protein kinase on HFD, whereas Helz2-deficient db/db mice lacking functional Leprb did not. Fatty acid-β oxidation was increased in Helz2-deficeint hepatocytes, and Helz2-deficient mice revealed increased oxygen consumption and decreased respiratory quotient in calorimetry analyses. The enhanced hepatic AMP-activated protein kinase energy-sensing pathway in Helz2-deficient mice ameliorated hyperlipidemia, hepatosteatosis, and insulin resistance by reducing lipogenic gene expression and stimulating lipid-burning gene expression in the liver. These findings together demonstrate that Helz2 deficiency ameliorates HFD-induced metabolic abnormalities by stimulating endogenous hepatic Leprb expression, despite central leptin resistance. Hepatic HELZ2 might be a novel target molecule for

  8. Impaired Coronary and Renal Vascular Function in Spontaneously Type 2 Diabetic Leptin-Deficient Mice.

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    Helena U Westergren

    Full Text Available Type 2 diabetes is associated with macro- and microvascular complications in man. Microvascular dysfunction affects both cardiac and renal function and is now recognized as a main driver of cardiovascular mortality and morbidity. However, progression of microvascular dysfunction in experimental models is often obscured by macrovascular pathology and consequently demanding to study. The obese type 2 diabetic leptin-deficient (ob/ob mouse lacks macrovascular complications, i.e. occlusive atherosclerotic disease, and may therefore be a potential model for microvascular dysfunction. The present study aimed to test the hypothesis that these mice with an insulin resistant phenotype might display microvascular dysfunction in both coronary and renal vascular beds.In this study we used non-invasive Doppler ultrasound imaging to characterize microvascular dysfunction during the progression of diabetes in ob/ob mice. Impaired coronary flow velocity reserve was observed in the ob/ob mice at 16 and 21 weeks of age compared to lean controls. In addition, renal resistivity index as well as pulsatility index was higher in the ob/ob mice at 21 weeks compared to lean controls. Moreover, plasma L-arginine was lower in ob/ob mice, while asymmetric dimethylarginine was unaltered. Furthermore, a decrease in renal vascular density was observed in the ob/ob mice.In parallel to previously described metabolic disturbances, the leptin-deficient ob/ob mice also display cardiac and renal microvascular dysfunction. This model may therefore be suitable for translational, mechanistic and interventional studies to improve the understanding of microvascular complications in type 2 diabetes.

  9. Ablation of ghrelin receptor in leptin-deficient ob/ob mice has paradoxical effects on glucose homeostasis when compared with ablation of ghrelin in ob/ob mice

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    The orexigenic hormone ghrelin is important in diabetes because it has an inhibitory effect on insulin secretion. Ghrelin ablation in leptin-deficient ob/ob (Ghrelin(-/-):ob/ob) mice increases insulin secretion and improves hyperglycemia. The physiologically relevant ghrelin receptor is the growth ...

  10. Leptin deficiency-induced obesity affects the density of mast cells in abdominal fat depots and lymph nodes in mice

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    Altintas Mehmet M

    2012-02-01

    Full Text Available Abstract Background Mast cells are implicated in the pathogenesis of obesity and insulin resistance. Here, we explored the effects of leptin deficiency-induced obesity on the density of mast cells in metabolic (abdominal fat depots, skeletal muscle, and liver and lymphatic (abdominal lymph nodes, spleen, and thymus organs. Fourteen-week-old male leptin-deficient ob/ob mice and their controls fed a standard chow were studied. Tissue sections were stained with toluidine blue to determine the density of mast cells. CD117/c-kit protein expression analysis was also carried out. Furthermore, mast cells containing immunoreactive tumor necrosis factor-α (TNF-α, a proinflammatory cytokine involved in obesity-linked insulin resistance, were identified by immunostaining. Results ob/ob mice demonstrated adiposity and insulin resistance. In abdominal fat depots, mast cells were distributed differentially. While most prevalent in subcutaneous fat in controls, mast cells were most abundant in epididymal fat in ob/ob mice. Leptin deficiency-induced obesity was accompanied by a 20-fold increase in the density of mast cells in epididymal fat, but a 13-fold decrease in subcutaneous fat. This finding was confirmed by CD117/c-kit protein expression analysis. Furthermore, we found that a subset of mast cells in epididymal and subcutaneous fat were immunoreactive for TNF-α. The proportion of mast cells immunoreactive for TNF-α was higher in epididymal than in subcutaneous fat in both ob/ob and control mice. Mast cells were also distributed differentially in retroperitoneal, mesenteric, and inguinal lymph nodes. In both ob/ob mice and lean controls, mast cells were more prevalent in retroperitoneal than in mesenteric and inguinal lymph nodes. Leptin deficiency-induced obesity was accompanied by increased mast cell density in all lymph node stations examined. No significant difference in the density of mast cells in skeletal muscle, liver, spleen, and thymus was

  11. Growth restriction, leptin, and the programming of adult behavior in mice.

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    Meyer, Lauritz R; Zhu, Vivian; Miller, Alise; Roghair, Robert D

    2014-12-15

    Prematurity and neonatal growth restriction (GR) are risk factors for autism and attention deficit hyperactivity disorder (ADHD). Leptin production is suppressed during periods of undernutrition, and we have shown that isolated neonatal leptin deficiency leads to adult hyperactivity while neonatal leptin supplementation normalizes the brain morphology of GR mice. We hypothesized that neonatal leptin would prevent the development of GR-associated behavioral abnormalities. From postnatal day 4-14, C57BL/6 mice were randomized to daily injections of saline or leptin (80ng/g), and GR was identified by a weanling weight below the tenth percentile. The behavioral phenotypes of GR and control mice were assessed beginning at 4 months. Within the tripartite chamber, GR mice had significantly impaired social interaction. Baseline escape times from the Barnes maze were faster for GR mice (65+/-6s vs 87+/-7s for controls, phormone leptin mitigates these effects. We speculate neonatal leptin deficiency may contribute to the adverse neurodevelopmental outcomes associated with postnatal growth restriction, and postnatal leptin therapy may be protective. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Whole-Body Vibration Mimics the Metabolic Effects of Exercise in Male Leptin Receptor-Deficient Mice.

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    McGee-Lawrence, Meghan E; Wenger, Karl H; Misra, Sudipta; Davis, Catherine L; Pollock, Norman K; Elsalanty, Mohammed; Ding, Kehong; Isales, Carlos M; Hamrick, Mark W; Wosiski-Kuhn, Marlena; Arounleut, Phonepasong; Mattson, Mark P; Cutler, Roy G; Yu, Jack C; Stranahan, Alexis M

    2017-05-01

    Whole-body vibration (WBV) has gained attention as a potential exercise mimetic, but direct comparisons with the metabolic effects of exercise are scarce. To determine whether WBV recapitulates the metabolic and osteogenic effects of physical activity, we exposed male wild-type (WT) and leptin receptor-deficient (db/db) mice to daily treadmill exercise (TE) or WBV for 3 months. Body weights were analyzed and compared with WT and db/db mice that remained sedentary. Glucose and insulin tolerance testing revealed comparable attenuation of hyperglycemia and insulin resistance in db/db mice following TE or WBV. Both interventions reduced body weight in db/db mice and normalized muscle fiber diameter. TE or WBV also attenuated adipocyte hypertrophy in visceral adipose tissue and reduced hepatic lipid content in db/db mice. Although the effects of leptin receptor deficiency on cortical bone structure were not eliminated by either intervention, exercise and WBV increased circulating levels of osteocalcin in db/db mice. In the context of increased serum osteocalcin, the modest effects of TE and WBV on bone geometry, mineralization, and biomechanics may reflect subtle increases in osteoblast activity in multiple areas of the skeleton. Taken together, these observations indicate that WBV recapitulates the effects of exercise on metabolism in type 2 diabetes.

  13. Kefir improves fatty liver syndrome by inhibiting the lipogenesis pathway in leptin-deficient ob/ob knockout mice.

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    Chen, H-L; Tung, Y-T; Tsai, C-L; Lai, C-W; Lai, Z-L; Tsai, H-C; Lin, Y-L; Wang, C-H; Chen, C-M

    2014-09-01

    Fatty liver disease is commonly associated with obesity, insulin resistance and diabetes. Severe fatty liver is sometimes accompanied by steatohepatitis and may lead to the development of hepatocellular carcinoma. At present, there is no effective treatment for non-alcoholic fatty liver disease (NAFLD); thus, recent investigations have focused on developing effective therapeutics to treat this condition. This study aimed to evaluate the effects of kefir on the hepatic lipid metabolism of ob/ob mice, which are commonly used to model fatty liver disease. In this study, we used leptin receptor-deficient ob/ob mice as an animal disease model of NAFLD. Six-week-old ob/ob mice were orally administered the dairy product kefir (140 mg kg(-1) of body weight (BW) per day) for 4 weeks. The data demonstrated that kefir improved fatty liver syndrome on BW, energy expenditure and basal metabolic rate by inhibiting serum glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT) activities (Pkefir administration also significantly reduced the macrovesicular fat quantity in liver tissue. In addition, kefir markedly decreased the expression of the genes sterol regulatory element-binding protein 1 (SREBP1), fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC) (Pkefir improves NAFLD on BW, energy expenditure and basal metabolic rate by inhibiting the lipogenesis pathway and that kefir may have the potential for clinical application to the prevention or treatment of NAFLD.

  14. Validity of leptin receptor-deficiency (db/db) type 2 diabetes mellitus mice as a model of secondary osteoporosis

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    Huang, Le; You, Yong-Ke; Zhu, Tracy Y.; Zheng, Li-Zhen; Huang, Xiao-Ru; Chen, Hai-Yong; Yao, Dong; Lan, Hui-Yao; Qin, Ling

    2016-06-01

    This study aimed to evaluate the validation of the leptin receptor-deficient mice model for secondary osteoporosis associated with type 2 diabetes mellitus (T2DM) at bone micro-architectural level. Thirty three 36-week old male mice were divided into four groups: normal control (db/m) (n = 7), leptin receptor-deficient T2DM (db/db) (n = 8), human C-reactive protein (CRP) transgenic normal control (crp/db/m) (n = 7), and human CRP transgenic T2DM (crp/db/db) (n = 11). Lumber vertebrae (L5) and bilateral lower limbs were scanned by micro-CT to analyze trabecular and cortical bone quality. Right femora were used for three-point bending to analyze the mechanical properties. Trabecular bone quality at L5 was better in db/db or crp/db/db group in terms of bone mineral density (BMD), bone volume fraction, connectivity density, trabecular number and separation (all p  0.05). Maximum loading and energy yield in mechanical test were similar among groups while the elastic modulus in db/db and crp/db/db significantly lower than db/m. The leptin-receptor mice is not a proper model for secondary osteoporosis associated with T2DM.

  15. Leptin Is Required for Glucose Homeostasis after Roux-en-Y Gastric Bypass in Mice.

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    Mohamad Mokadem

    Full Text Available Leptin, the protein product of the ob gene, increases energy expenditure and reduces food intake, thereby promoting weight reduction. Leptin also regulates glucose homeostasis and hepatic insulin sensitivity via hypothalamic proopiomelanocortin neurons in mice. Roux-en-Y gastric bypass (RYGB induces weight loss that is substantial and sustained despite reducing plasma leptin levels. In addition, patients who fail to undergo diabetes remission after RYGB are hypoletinemic compared to those who do and to lean controls. We have previously demonstrated that the beneficial effects of RYGB in mice require the melanocortin-4 receptor, a downstream effector of leptin action. Based on these observations, we hypothesized that leptin is required for sustained weight reduction and improved glucose homeostasis observed after RYGB.To investigate this hypothesis, we performed RYGB or sham operations on leptin-deficient ob/ob mice maintained on regular chow. To investigate whether leptin is involved in post-RYGB weight maintenance, we challenged post-surgical mice with high fat diet.RYGB reduced total body weight, fat and lean mass and caused reduction in calorie intake in ob/ob mice. However, it failed to improve glucose tolerance, glucose-stimulated plasma insulin, insulin tolerance, and fasting plasma insulin. High fat diet eliminated the reduction in calorie intake observed after RYGB in ob/ob mice and promoted weight regain, although not to the same extent as in sham-operated mice. We conclude that leptin is required for the effects of RYGB on glucose homeostasis but not body weight or composition in mice. Our data also suggest that leptin may play a role in post-RYGB weight maintenance.

  16. Congenital leptin deficiency and thyroid function

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    Paz-Filho Gilberto

    2009-11-01

    Full Text Available Abstract Thyroid function is closely related to leptin's secretion by the adipose tissue. In states of leptin-deficiency, the circadian rhythm of TSH is altered, leading to central hypothyroidism in animal models. In humans, central hypothyroidism has also been described in rare cases of congenital leptin deficiency. However, the thyroid phenotype in these cases is heterogeneous, with the occurrence of central hypothyroidism in a minority of cases. Here we describe thyroid function in four leptin-deficient humans (2 males aged 5 and 27, and 2 females aged 35 and 40, before and during leptin replacement with recombinant human methionyl leptin (r-metHuLeptin. The child was evaluated for four years, and the adults, for eight years. In addition, the adults were submitted to a brief withdrawal of leptin during six weeks in the sixth year. Our results show that, regardless of leptin replacement, our leptin-deficient patients have normal thyroid function. In spite of having an important role in regulating the hypothalamic-pituitary-thyroidal axis, leptin is not required for normal thyroid function. Trial Registration ClinicalTrials.gov Identifiers: NCT00659828 and NCT00657605

  17. Mechanical Vibration Mitigates the Decrease of Bone Quantity and Bone Quality of Leptin Receptor-Deficient Db/Db Mice by Promoting Bone Formation and Inhibiting Bone Resorption.

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    Jing, Da; Luo, Erping; Cai, Jing; Tong, Shichao; Zhai, Mingming; Shen, Guanghao; Wang, Xin; Luo, Zhuojing

    2016-09-01

    Leptin, a major hormonal product of adipocytes, is involved in regulating appetite and energy metabolism. Substantial studies have revealed the anabolic actions of leptin on skeletons and bone cells both in vivo and in vitro. Growing evidence has substantiated that leptin receptor-deficient db/db mice exhibit decreased bone mass and impaired bone microstructure despite several conflicting results previously reported. We herein systematically investigated bone microarchitecture, mechanical strength, bone turnover and its potential molecular mechanisms in db/db mice. More importantly, we also explored an effective approach for increasing bone mass in leptin receptor-deficient animals in an easy and noninvasive manner. Our results show that deterioration of trabecular and cortical bone microarchitecture and decreases of skeletal mechanical strength-including maximum load, yield load, stiffness, energy, tissue-level modulus and hardness-in db/db mice were significantly ameliorated by 12-week, whole-body vibration (WBV) with 0.5 g, 45 Hz via micro-computed tomography (μCT), three-point bending, and nanoindentation examinations. Serum biochemical analysis shows that WBV significantly decreased serum tartrate-resistant acid phosphatase 5b (TRACP5b) and CTx-1 levels and also mitigated the reduction of serum osteocalcin (OCN) in db/db mice. Bone histomorphometric analysis confirmed that decreased bone formation-lower mineral apposition rate, bone formation rate, and osteoblast numbers in cancellous bone-in db/db mice were suppressed by WBV. Real-time PCR assays show that WBV mitigated the reductions of tibial alkaline phosphatase (ALP), OCN, Runt-related transcription factor 2 (RUNX2), type I collagen (COL1), BMP2, Wnt3a, Lrp6, and β-catenin mRNA expression, and prevented the increases of tibial sclerostin (SOST), RANK, RANKL, RANL/osteoprotegerin (OPG) gene levels in db/db mice. Our results show that WBV promoted bone quantity and quality in db/db mice with obvious

  18. Deficiency of leptin receptor in myeloid cells disrupts hypothalamic metabolic circuits and causes body weight increase

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    Yuanqing Gao

    2018-01-01

    Conclusions: Myeloid cell leptin receptor deficient mice partially replicate the db/db phenotype. Leptin signaling in hypothalamic microglia is important for microglial function and a correct formation of the hypothalamic neuronal circuit regulating metabolism.

  19. Leptin Production by Encapsulated Adipocytes Increases Brown Fat, Decreases Resistin, and Improves Glucose Intolerance in Obese Mice.

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    David J DiSilvestro

    Full Text Available The neuroendocrine effects of leptin on metabolism hold promise to be translated into a complementary therapy to traditional insulin therapy for diabetes and obesity. However, injections of leptin can provoke inflammation. We tested the effects of leptin, produced in the physiological adipocyte location, on metabolism in mouse models of genetic and dietary obesity. We generated 3T3-L1 adipocytes constitutively secreting leptin and encapsulated them in a poly-L-lysine membrane, which protects the cells from immune rejection. Ob/ob mice (OB were injected with capsules containing no cells (empty, OB[Emp], adipocytes (OB[3T3], or adipocytes overexpressing leptin (OB[Lep] into both visceral fat depots. Leptin was found in the plasma of OB[Lep], but not OB[Emp] and OB[3T3] mice at the end of treatment (72 days. The OB[Lep] and OB[3T3] mice have transiently suppressed appetite and weight loss compared to OB[Emp]. Only OB[Lep] mice have greater brown fat mass, metabolic rate, and reduced resistin plasma levels compared to OB[Emp]. Glucose tolerance was markedly better in OB[Lep] vs. OB[Emp] and OB[3T3] mice as well as in wild type mice with high-fat diet-induced obesity and insulin resistance treated with encapsulated leptin-producing adipocytes. Our proof-of-principle study provides evidence of long-term improvement of glucose tolerance with encapsulated adipocytes producing leptin.

  20. Leptin deficiency: clinical implications and opportunities for therapeutic interventions.

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    Blüher, Susan; Shah, Sunali; Mantzoros, Christos S

    2009-10-01

    The discovery of leptin has significantly advanced our understanding of the metabolic importance of adipose tissue and has revealed that both leptin deficiency and leptin excess are associated with severe metabolic, endocrine, and immunological consequences. We and others have shown that a prominent role of leptin in humans is to mediate the neuroendocrine adaptation to energy deprivation. Humans with genetic mutations in the leptin and leptin receptor genes have deregulated food intake and energy expenditure leading to a morbidly obese phenotype and a disrupted regulation in neuroendocrine and immune function and in glucose and fat metabolism. Observational and interventional studies in humans with (complete) congenital leptin deficiency caused by mutations in the leptin gene or with relative leptin deficiency as seen in states of negative energy balance such as lipoatrophy, anorexia nervosa, or exercise-induced hypothalamic and neuroendocrine dysfunction have contributed to the elucidation of the pathophysiological role of leptin in these conditions and of the clinical significance of leptin administration in these subjects. More specifically, interventional studies have demonstrated that several neuroendocrine, metabolic, or immune disturbances in these states could be restored by leptin administration. Leptin replacement therapy is currently available through a compassionate use program for congenital complete leptin deficiency and under an expanded access program to subjects with leptin deficiency associated with congenital or acquired lipoatrophy. In addition, leptin remains a potentially forthcoming treatment for several other states of energy deprivation including anorexia nervosa or milder forms of hypothalamic amenorrhea pending appropriate clinical trials.

  1. Enhanced leptin sensitivity and improved glucose homeostasis in mice lacking suppressor of cytokine signaling-3 in POMC-expressing cells.

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    Kievit, Paul; Howard, Jane K; Badman, Michael K; Balthasar, Nina; Coppari, Roberto; Mori, Hiroyuki; Lee, Charlotte E; Elmquist, Joel K; Yoshimura, Akihiko; Flier, Jeffrey S

    2006-08-01

    Suppressor of cytokine signaling-3 (Socs-3) negatively regulates the action of various cytokines, as well as the metabolic hormones leptin and insulin. Mice with haploinsufficiency of Socs-3, or those with neuronal deletion of Socs-3, are lean and more leptin and insulin sensitive. To examine the role of Socs-3 within specific neurons critical to energy balance, we created mice with selective deletion of Socs-3 within pro-opiomelanocortin (POMC)-expressing cells. These mice had enhanced leptin sensitivity, measured by weight loss and food intake after leptin infusion. On chow diet, glucose homeostasis was improved despite normal weight gain. On a high-fat diet, the rate of weight gain was reduced, due to increased energy expenditure rather than decreased food intake; glucose homeostasis and insulin sensitivity were substantially improved. These studies demonstrate that Socs-3 within POMC neurons regulates leptin sensitivity and glucose homeostasis, and plays a key role in linking high-fat diet to disordered metabolism.

  2. Leptin Reduces the Expression and Increases the Phosphorylation of the Negative Regulators of GLUT4 Traffic TBC1D1 and TBC1D4 in Muscle of ob/ob Mice

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    Sáinz, Neira; Rodríguez, Amaia; Catalán, Victoria; Becerril, Sara; Ramírez, Beatriz; Lancha, Andoni; Burgos-Ramos, Emma; Gómez-Ambrosi, Javier; Frühbeck, Gema

    2012-01-01

    Leptin improves insulin sensitivity in skeletal muscle. Our goal was to determine whether proteins controlling GLUT4 traffic are altered by leptin deficiency and in vivo leptin administration in skeletal muscle of wild type and ob/ob mice. Leptin-deficient ob/ob mice were divided in three groups: control, leptin-treated (1 mg/kg/d) and leptin pair-fed ob/ob mice. Microarray analysis revealed that 1,546 and 1,127 genes were regulated by leptin deficiency and leptin treatment, respectively. Among these, we identified 24 genes involved in intracellular vesicle-mediated transport in ob/ob mice. TBC1 domain family, member 1 (Tbc1d1), a negative regulator of GLUT4 translocation, was up-regulated (P = 0.001) in ob/ob mice as compared to wild types. Importantly, leptin treatment reduced the transcript levels of Tbc1d1 (P<0.001) and Tbc1d4 (P = 0.004) in the leptin-treated ob/ob as compared to pair-fed ob/ob animals. In addition, phosphorylation levels of TBC1D1 and TBC1D4 were enhanced in leptin-treated ob/ob as compared to control ob/ob (P = 0.015 and P = 0.023, respectively) and pair-fed ob/ob (P = 0.036 and P = 0.034, respectively) mice. Despite similar GLUT4 protein expression in wild type and ob/ob groups a different immunolocalization of this protein was evidenced in muscle sections. Leptin treatment increased GLUT4 immunoreactivity in gastrocnemius and extensor digitorum longus sections of leptin-treated ob/ob mice. Moreover, GLUT4 protein detected in immunoprecipitates from TBC1D4 was reduced by leptin replacement compared to control ob/ob (P = 0.013) and pair-fed ob/ob (P = 0.037) mice. Our findings suggest that leptin enhances the intracellular GLUT4 transport in skeletal muscle of ob/ob animals by reducing the expression and activity of the negative regulators of GLUT4 traffic TBC1D1 and TBC1D4. PMID:22253718

  3. Hypothalamic Leptin Gene Therapy Reduces Bone Marrow Adiposity in ob/ob Mice Fed Regular and High Fat Diets

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    Laurence B Lindenmaier

    2016-08-01

    Full Text Available Low bone mass is often associated with increased bone marrow adiposity. Since osteoblasts and adipocytes are derived from the same mesenchymal stem cell progenitor, adipocyte formation may increase at the expense of osteoblast formation. Leptin is an adipocyte-derived hormone known to regulate energy and bone metabolism. Genetic (e.g., leptin deficiency and high fat diet-induced (e.g., leptin resistance obesity are associated with increased marrow adipose tissue (MAT and reduced bone formation. Short-duration studies suggest that leptin treatment reduces MAT and increases bone formation in leptin-deficient ob/ob mice fed a regular diet. Here, we determined the long-duration impact of increased hypothalamic leptin on marrow adipocytes and osteoblasts in ob/ob mice using recombinant adeno-associated virus (rAAV gene therapy. In a first study, eight- to ten-week-old male ob/ob mice were randomized into 4 groups: (1 untreated, (2 rAAV-Lep, (3 rAAV-green fluorescent protein (rAAV-GFP, or (4 pair-fed to rAAV-Lep. For vector administration, mice were placed in a Kopf stereotaxic apparatus, and injected intracerebroventricularly with either rAAV-Lep or rAAV-GFP (9 × 107 particles in 1.5 µl. The mice were maintained for 30 weeks following vector administration. In a second study, the impact of increased hypothalamic leptin levels on MAT was determined in mice fed high fat diets. Eight- to ten-week-old male ob/ob mice were randomized into 2 groups and treated with either rAAV-Lep or rAAV-GFP. At 7 weeks post-vector administration, half the mice in each group were switched to a high fat diet for 8 weeks. Wild type (WT controls included age-matched mice fed regular or high fat diet. Hypothalamic leptin gene therapy increased osteoblast perimeter and osteoclast perimeter with minor change in cancellous bone architecture. The gene therapy decreased MAT levels in ob/ob mice fed regular or high fat diet to values similar to WT mice fed regular diet. These

  4. Leptin Deficiency: Clinical Implications and Opportunities for Therapeutic Interventions

    OpenAIRE

    Bl?her, Susan; Shah, Sunali; Mantzoros, Christos S.

    2009-01-01

    The discovery of leptin has significantly advanced our understanding of the metabolic importance of adipose tissue and has revealed that both leptin deficiency and leptin excess are associated with severe metabolic, endocrine, and immunological consequences. We and others have shown that a prominent role of leptin in humans is to mediate the neuroendocrine adaptation to energy deprivation. Humans with genetic mutations in the leptin and leptin receptor genes have deregulated food intake and e...

  5. Control of blood pressure, appetite, and glucose by leptin in mice lacking leptin receptors in proopiomelanocortin neurons.

    Science.gov (United States)

    do Carmo, Jussara M; da Silva, Alexandre A; Cai, Zhengwei; Lin, Shuying; Dubinion, John H; Hall, John E

    2011-05-01

    Although the central nervous system melanocortin system is an important regulator of energy balance, the role of proopiomelanocortin (POMC) neurons in mediating the chronic effects of leptin on appetite, blood pressure, and glucose regulation is unknown. Using Cre/loxP technology we tested whether leptin receptor deletion in POMC neurons (LepR(flox/flox)/POMC-Cre mice) attenuates the chronic effects of leptin to increase mean arterial pressure (MAP), enhance glucose use and oxygen consumption, and reduce appetite. LepR(flox/flox)/POMC-Cre, wild-type, LepR(flox/flox), and POMC-Cre mice were instrumented for MAP and heart rate measurement by telemetry and venous catheters for infusions. LepR(flox/flox)/POMC-Cre mice were heavier, hyperglycemic, hyperinsulinemic, and hyperleptinemic compared with wild-type, LepR(flox/flox), and POMC-Cre mice. Despite exhibiting features of metabolic syndrome, LepR(flox/flox)/POMC-Cre mice had normal MAP and heart rate compared with LepR(flox/flox) but lower MAP and heart rate compared with wild-type mice. After a 5-day control period, leptin was infused (2 μg/kg per minute, IV) for 7 days. In control mice, leptin increased MAP by ≈5 mm Hg despite decreasing food intake by ≈35%. In contrast, leptin infusion in LepR(flox/flox)/POMC-Cre mice reduced MAP by ≈3 mm Hg and food intake by ≈28%. Leptin significantly decreased insulin and glucose levels in control mice but not in LepR(flox/flox)/POMC-Cre mice. Leptin increased oxygen consumption in LepR(flox/flox)/POMC-Cre and wild-type mice. Activation of POMC neurons is necessary for the chronic effects of leptin to raise MAP and reduce insulin and glucose levels, whereas leptin receptors in other areas of the brain other than POMC neurons appear to play a key role in mediating the chronic effects of leptin on appetite and oxygen consumption.

  6. Leptin regulates bone formation via the sympathetic nervous system

    Science.gov (United States)

    Takeda, Shu; Elefteriou, Florent; Levasseur, Regis; Liu, Xiuyun; Zhao, Liping; Parker, Keith L.; Armstrong, Dawna; Ducy, Patricia; Karsenty, Gerard

    2002-01-01

    We previously showed that leptin inhibits bone formation by an undefined mechanism. Here, we show that hypothalamic leptin-dependent antiosteogenic and anorexigenic networks differ, and that the peripheral mediators of leptin antiosteogenic function appear to be neuronal. Neuropeptides mediating leptin anorexigenic function do not affect bone formation. Leptin deficiency results in low sympathetic tone, and genetic or pharmacological ablation of adrenergic signaling leads to a leptin-resistant high bone mass. beta-adrenergic receptors on osteoblasts regulate their proliferation, and a beta-adrenergic agonist decreases bone mass in leptin-deficient and wild-type mice while a beta-adrenergic antagonist increases bone mass in wild-type and ovariectomized mice. None of these manipulations affects body weight. This study demonstrates a leptin-dependent neuronal regulation of bone formation with potential therapeutic implications for osteoporosis.

  7. Voluntary exercise improves high-fat diet-induced leptin resistance independent of adiposity.

    Science.gov (United States)

    Krawczewski Carhuatanta, Kimberly A; Demuro, Giovanna; Tschöp, Matthias H; Pfluger, Paul T; Benoit, Stephen C; Obici, Silvana

    2011-07-01

    The efficacy of exercise as primary prevention of obesity is the subject of intense investigation. Here, we show that voluntary exercise in a mouse strain susceptible to diet-induced obesity (C57B6J) decreases fat mass and increases energy expenditure. In addition, exercise attenuates obesity in mice fed a high-fat diet (HFD). Using FosB immunoreactivity as a marker of chronic neuronal activation, we found that exercise activates leptin receptor-positive neurons in the ventromedial hypothalamic nucleus, involved in homeostatic control of energy balance. FosB immunoreactivity in the ventromedial hypothalamic nucleus is decreased in sedentary mice exposed to HFD but is increased in exercised mice independent of adiposity. To determine whether the antiobesity effects of voluntary exercise improve central nervous system (CNS) leptin action, we measured the anorectic and weight reducing effects of intracerebroventricular (ICV) leptin in sedentary and exercised mice exposed to HFD (EH), as well as in sedentary mice that have been calorie restricted (SR) to match the fat mass of EH mice. ICV leptin was ineffective in lowering food intake and body weight (BW) in sedentary mice exposed to HFD mice. The anorectic potency of leptin was partially restored in EH and SR groups. However, ICV leptin significantly lowered BW in EH but not SR mice. Thus, exercise leads to the maintenance of a lower BW and leaner composition, as well as to improved CNS leptin action, independent of fat mass. These results support the notion that physical exercise directly influences the responsiveness of the CNS circuits involved in energy homeostasis by allowing the defense of a lowered BW.

  8. Leptin differentially regulates STAT3 activation in the ob/ob mice adipose mesenchymal stem cells

    Science.gov (United States)

    Leptin-deficient genetically obese ob/ob mice exhibit adipocyte hypertrophy and hyperplasia as well as elevated adipose tissue and systemic inflammation. Studies have shown that multipotent stem cells isolated from adult adipose tissue can differentiate into adipocytes ex vivo and thereby contribute...

  9. Stearoyl-CoA desaturase deficiency, hypercholesterolaemia, cholestasis and diabetes

    NARCIS (Netherlands)

    Attie, Alan D.; Flowers, Matthew T.; Flowers, Jessica B.; Groen, Albert K.; Kuipers, Folkert; Ntambi, James M.

    2007-01-01

    Previous studies have shown that mice deficient in Scd1 have a dramatically reduced level of liver triglyceride and an improvement in insulin sensitivity. The mice are lean and partially protected from obesity induced by leptin deficiency or high fat diets. These results predicted that Scd1(-/-)

  10. Leptin deficiency-induced obesity exacerbates ultraviolet B radiation-induced cyclooxygenase-2 expression and cell survival signals in ultraviolet B-irradiated mouse skin

    International Nuclear Information System (INIS)

    Sharma, Som D.; Katiyar, Santosh K.

    2010-01-01

    Obesity has been implicated in several inflammatory diseases and in different types of cancer. Chronic inflammation induced by exposure to ultraviolet (UV) radiation has been implicated in various skin diseases, including melanoma and nonmelanoma skin cancers. As the relationship between obesity and susceptibility to UV radiation-caused inflammation is not clearly understood, we assessed the role of obesity on UVB-induced inflammation, and mediators of this inflammatory response, using the genetically obese (leptin-deficient) mouse model. Leptin-deficient obese (ob/ob) mice and wild-type counterparts (C57/BL6 mice) were exposed to UVB radiation (120 mJ/cm 2 ) on alternate days for 1 month. The mice were then euthanized and skin samples collected for analysis of biomarkers of inflammatory responses using immunohistochemistry, western blotting, ELISA and real-time PCR. Here, we report that the levels of inflammatory responses were higher in the UVB-exposed skin of the ob/ob obese mice than those in the UVB-exposed skin of the wild-type non-obese mice. The levels of UVB-induced cyclooxygenase-2 expression, prostaglandin-E 2 production, proinflammatory cytokines (i.e., tumor necrosis factor-α, interleukin-1β, interleukin-6), and proliferating cell nuclear antigen and cell survival signals (phosphatidylinositol-3-kinase and p-Akt-Ser 473 ) were higher in the skin of the ob/ob obese mice than the those in skin of their wild-type non-obese counterparts. Compared with the wild-type non-obese mice, the leptin-deficient obese mice also exhibited greater activation of NF-κB/p65 and fewer apoptotic cells in the UVB-irradiated skin. Our study suggests for the first time that obesity in mice is associated with greater susceptibility to UVB-induced inflammatory responses and, therefore, obesity may increase susceptibility to UVB-induced inflammation-associated skin diseases, including the risk of skin cancer.

  11. Selective Deletion of Leptin Signaling in Endothelial Cells Enhances Neointima Formation and Phenocopies the Vascular Effects of Diet-Induced Obesity in Mice.

    Science.gov (United States)

    Hubert, Astrid; Bochenek, Magdalena L; Schütz, Eva; Gogiraju, Rajinikanth; Münzel, Thomas; Schäfer, Katrin

    2017-09-01

    Obesity is associated with elevated circulating leptin levels and hypothalamic leptin resistance. Leptin receptors (LepRs) are expressed on endothelial cells, and leptin promotes neointima formation in a receptor-dependent manner. Our aim was to examine the importance of endothelial LepR (End.LepR) signaling during vascular remodeling and to determine whether the cardiovascular consequences of obesity are because of hyperleptinemia or endothelial leptin resistance. Mice with loxP-flanked LepR alleles were mated with mice expressing Cre recombinase controlled by the inducible endothelial receptor tyrosine kinase promoter. Obesity was induced with high-fat diet. Neointima formation was examined after chemical carotid artery injury. Morphometric quantification revealed significantly greater intimal hyperplasia, neointimal cellularity, and proliferation in End.LepR knockout mice, and similar findings were obtained in obese, hyperleptinemic End.LepR wild-type animals. Analysis of primary endothelial cells confirmed abrogated signal transducer and activator of transcription-3 phosphorylation in response to leptin in LepR knockout and obese LepR wild-type mice. Quantitative PCR, ELISA, and immunofluorescence analyses revealed increased expression and release of endothelin-1 in End.LepR-deficient and LepR-resistant cells, and ET receptor A/B antagonists abrogated their paracrine effects on murine aortic smooth muscle cell proliferation. Reduced expression of peroxisome proliferator-activated receptor-γ and increased nuclear activator protein-1 staining was observed in End.LepR-deficient and LepR-resistant cells, and peroxisome proliferator-activated receptor-γ antagonization increased endothelial endothelin-1 expression. Our findings suggest that intact endothelial leptin signaling limits neointima formation and that obesity represents a state of endothelial leptin resistance. These observations and the identification of endothelin-1 as soluble mediator of the

  12. Genetic ablation of phosphatidylcholine transfer protein/StarD2 in ob/ob mice improves glucose tolerance without increasing energy expenditure.

    Science.gov (United States)

    Krisko, Tibor I; LeClair, Katherine B; Cohen, David E

    2017-03-01

    Phosphatidylcholine transfer protein (PC-TP; synonym StarD2) is highly expressed in liver and oxidative tissues. PC-TP promotes hepatic glucose production during fasting and aggravates glucose intolerance in high fat fed mice. However, because PC-TP also suppresses thermogenesis in brown adipose tissue (BAT), its direct contribution to obesity-associated diabetes in mice remains unclear. Here we examined the effects of genetic PC-TP ablation on glucose homeostasis in leptin-deficient ob/ob mice, which exhibit both diabetes and altered thermoregulation. Mice lacking both PC-TP and leptin (Pctp -/- ;ob/ob) were prepared by crossing Pctp -/- with ob/+ mice. Glucose homeostasis was assessed by standard assays, and energy expenditure was determined by indirect calorimetry using a comprehensive laboratory animal monitoring system, which also recorded physical activity and food intake. Body composition was determined by NMR and hepatic lipids by enzymatic assays. Core body temperature was measured using a rectal thermocouple probe. Pctp -/- ;ob/ob mice demonstrated improved glucose homeostasis, as evidenced by markedly improved glucose and pyruvate tolerance tests, without changes in insulin tolerance. However, there were no differences in EE at any ambient temperature. There were also no effects of PC-TP expression on physical activity, food intake or core body temperature. Improved glucose tolerance in Pctp -/- ;ob/ob mice in the absence of increases in energy expenditure or core body temperature indicates a direct pathogenic role for PC-TP in diabetes in leptin deficient mice. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. ROLE OF LEPTIN ON CYTOCHROME P-450 AND SOME LIVER MICROSOMAL ENZYMES ACTIVITIES IN THE OBESE AND LEAN MICE

    International Nuclear Information System (INIS)

    HEBEISHY, M.I.A.; MAZEN, G.M.A.; SHAHIN, M.I

    2008-01-01

    Leptin is a hormone that is secreted by adipocytes and regulates body weight through its effect on satiety and energy metabolism. The obese mouse is deficient in this protein and is characterized by obesity and other metabolic disorders. This study investigated the alterations of several hepatic cytochrome P 4 -5 0 (CYP), conjugation and antioxidant enzymes in lean and obese mice and the role of leptin in the modulation of these enzymes. Lean and obese male mice were injected with leptin (100 μg / rat) for 15 days. The obtained results revealed that administration of leptin to lean mice caused a significant elevation in the level of blood glucose, serum insulin, 6α, 6β, 16α- hydroxylation of testosterone, the activity of CYP 1 A 1 , CYP 4 A and GSH reductase in liver microsomes while serum corticosterone and the activity of total GSH were significantly decreased when compared to lean control mice. Moreover, obese mice treated with leptin recorded significant reduction in body weight, blood glucose concentration, serum levels of insulin and corticosterone, 7α and 16α- hydroxylation of testosterone, the activity of CYP 1A 1, CYP 2 B 1 and CYP 4 A and GST in liver microsomes. On the other hand, 6α, 6β-hydroxylation of testosterone, the activity of CYP 2 E 1 and GSH reductase in liver microsome were significantly increased when compared to obese control mice. The mechanism for the observed alterations may be due to direct leptin effects or via indirect alterations in insulin, corticosterone and/or growth hormone

  14. Geranylgeranylacetone prevents stress-induced decline of leptin secretion in mice.

    Science.gov (United States)

    Itai, Miki; Kuwano, Yuki; Nishikawa, Tatsuya; Rokutan, Kazuhito; Kensei, Nishida

    2018-01-01

    Geranylgeranylacetone (GGA) is a chaperon inducer that protects various types of cell and tissue against stress. We examined whether GGA modulated energy intake and expenditure under stressful conditions. After mice were untreated or treated orally with GGA (0.16 g per kg body weight per day) for 10 days, they were subjected to 2-h restraint stress once or once a day for 5 consecutive days. GGA administration did not affect corticosterone response to the stress. Restraint stress rapidly decreased plasma leptin levels in control mice. GGA significantly increased circulating leptin levels without changing food intake and prevented the stress-induced decline of circulating leptin. However GGA-treated mice significantly reduced food intake during the repeated stress, compared with control mice. GGA prevented the stress-induced decline of leptin mRNA and its protein levels in epidydimal adipose tissues. We also found that GGA decreased ghrelin mRNA expression in gastric mucosa before the stress, whereas GGA-treated mice recovered the ghrelin mRNA expression to the baseline level after the repeated stress. Leptin and ghrelin are now recognized as regulators of anxiety and depressive mood. Our results suggest that GGA may regulate food intake and relief stress-induced mood disturbance through regulating leptin and ghrelin secretions. J. Med. Invest. 65:103-109, February, 2018.

  15. Increased susceptibility to diet-induced obesity in histamine-deficient mice

    DEFF Research Database (Denmark)

    Jørgensen, Emilie A; Vogelsang, Thomas W; Knigge, Ulrich

    2006-01-01

    in the development of high-fat diet (HFD)-induced obesity. METHODS: Histamine-deficient histidine decarboxylase knock-out (HDC-KO) mice and C57BL/6J wild-type (WT) mice were given either a standard diet (STD) or HFD for 8 weeks. Body weight, 24-hour caloric intake, epididymal adipose tissue size, plasma leptin...... weeks, whereas a significant difference in body weight gain was first observed after 5 weeks in WT mice. After 8 weeks 24-hour caloric intake was significantly lower in HFD- than in STD-fed WT mice. In HDC-KO mice no difference in caloric intake was observed between HFD- and STD-fed mice. After 8 weeks...

  16. Bilirubin Increases Insulin Sensitivity in Leptin-Receptor Deficient and Diet-Induced Obese Mice Through Suppression of ER Stress and Chronic Inflammation

    Science.gov (United States)

    Dong, Huansheng; Huang, Hu; Yun, Xinxu; Kim, Do-sung; Yue, Yinan; Wu, Hongju; Sutter, Alton; Chavin, Kenneth D.; Otterbein, Leo E.; Adams, David B.; Kim, Young-Bum

    2014-01-01

    Obesity-induced endoplasmic reticulum (ER) stress causes chronic inflammation in adipose tissue and steatosis in the liver, and eventually leads to insulin resistance and type 2 diabetes (T2D). The goal of this study was to understand the mechanisms by which administration of bilirubin, a powerful antioxidant, reduces hyperglycemia and ameliorates obesity in leptin-receptor-deficient (db/db) and diet-induced obese (DIO) mouse models. db/db or DIO mice were injected with bilirubin or vehicle ip. Blood glucose and body weight were measured. Activation of insulin-signaling pathways, expression of inflammatory cytokines, and ER stress markers were measured in skeletal muscle, adipose tissue, and liver of mice. Bilirubin administration significantly reduced hyperglycemia and increased insulin sensitivity in db/db mice. Bilirubin treatment increased protein kinase B (PKB/Akt) phosphorylation in skeletal muscle and suppressed expression of ER stress markers, including the 78-kDa glucose-regulated protein (GRP78), CCAAT/enhancer-binding protein (C/EBP) homologous protein, X box binding protein (XBP-1), and activating transcription factor 4 in db/db mice. In DIO mice, bilirubin treatment significantly reduced body weight and increased insulin sensitivity. Moreover, bilirubin suppressed macrophage infiltration and proinflammatory cytokine expression, including TNF-α, IL-1β, and monocyte chemoattractant protein-1, in adipose tissue. In liver and adipose tissue of DIO mice, bilirubin ameliorated hepatic steatosis and reduced expression of GRP78 and C/EBP homologous protein. These results demonstrate that bilirubin administration improves hyperglycemia and obesity by increasing insulin sensitivity in both genetically engineered and DIO mice models. Bilirubin or bilirubin-increasing drugs might be useful as an insulin sensitizer for the treatment of obesity-induced insulin resistance and type 2 diabetes based on its profound anti-ER stress and antiinflammatory properties. PMID

  17. Modest phenotypic improvements in ASA-deficient mice with only one UDP-galactose:ceramide-galactosyltransferase gene

    Directory of Open Access Journals (Sweden)

    De Deyn PP

    2006-08-01

    Full Text Available Summary Background Arylsulfatase A (ASA-deficient mice are a model for the lysosomal storage disorder metachromatic leukodystrophy. This lipidosis is characterised by the lysosomal accumulation of the sphingolipid sulfatide. Storage of this lipid is associated with progressive demyelination. We have mated ASA-deficient mice with mice heterozygous for a non-functional allele of UDP-galactose:ceramide-galactosyltransferase (CGT. This deficiency is known to lead to a decreased synthesis of galactosylceramide and sulfatide, which should reduce sulfatide storage and improve pathology in ASA-deficient mice. Results ASA-/- CGT+/- mice, however, showed no detectable decrease in sulfatide storage. Neuronal degeneration of cells in the spiral ganglion of the inner ear, however, was decreased. Behavioural tests showed small but clear improvements of the phenotype in ASA-/- CGT+/- mice. Conclusion Thus the reduction of galactosylceramide and sulfatide biosynthesis by genetic means overall causes modest improvements of pathology.

  18. CORRELATION BETWEEN GUT MICROBIOTA AND DEVELOPMENT OF GLUCOSE INTOLERANCE IN B6.V-Lepob/J LEPTIN DEFICIENT MICE

    DEFF Research Database (Denmark)

    Ellekilde, Merete; Hansen, Camilla Hartmann Friis; Nielsen, Dennis Sandris

    , a large proportion of laboratory animals are used to study such diseases, but inter-individual variation in these animal models leads to the need for larger group sizes to reach statistical significance and adequate power. By standardizing the microbial and immunological status of laboratory animals we...... may therefore be able to produce animals with a more standardized response and less variation. This would lead to more precise results and a reduced number of animals needed for statistical significance. The aim of the present study was to investigate if the composition of the GM of B6.V...... the mechanisms of how the GM influences disease development is necessary, but based on these results it seems reasonable to assume, that by controlling the GM we may also influence disease development of type 2 diabetes in B6.V-Lepob/J leptin deficient mice, and thereby produce animals with less variation, which...

  19. Epac2a-null mice exhibit obesity-prone nature more susceptible to leptin resistance.

    Science.gov (United States)

    Hwang, M; Go, Y; Park, J-H; Shin, S-K; Song, S E; Oh, B-C; Im, S-S; Hwang, I; Jeon, Y H; Lee, I-K; Seino, S; Song, D-K

    2017-02-01

    The exchange protein directly activated by cAMP (Epac), which is primarily involved in cAMP signaling, has been known to be essential for controlling body energy metabolism. Epac has two isoforms: Epac1 and Epac2. The function of Epac1 on obesity was unveiled using Epac1 knockout (KO) mice. However, the role of Epac2 in obesity remains unclear. To evaluate the role of Epac2 in obesity, we used Epac2a KO mice, which is dominantly expressed in neurons and endocrine tissues. Physiological factors related to obesity were analyzed: body weight, fat mass, food intake, plasma leptin and adiponectin levels, energy expenditure, glucose tolerance, and insulin and leptin resistance. To determine the mechanism of Epac2a, mice received exogenous leptin and then hypothalamic leptin signaling was analyzed. Epac2a KO mice appeared to have normal glucose tolerance and insulin sensitivity until 12 weeks of age, but an early onset increase of plasma leptin levels and decrease of plasma adiponectin levels compared with wild-type mice. Acute leptin injection revealed impaired hypothalamic leptin signaling in KO mice. Consistently, KO mice fed a high-fat diet (HFD) were significantly obese, presenting greater food intake and lower energy expenditure. HFD-fed KO mice were also characterized by greater impairment of hypothalamic leptin signaling and by weaker leptin-induced decrease in food consumption compared with HFD-fed wild-type mice. In wild-type mice, acute exogenous leptin injection or chronic HFD feeding tended to induce hypothalamic Epac2a expression. Considering that HFD is an inducer of hypothalamic leptin resistance and that Epac2a functions in pancreatic beta cells during demands of greater work load, hypothalamic Epac2a may have a role in facilitating leptin signaling, at least in response to higher metabolic demands. Thus, our data indicate that Epac2a is critical for preventing obesity and thus Epac2a activators may be used to manage obesity and obesity-mediated metabolic

  20. HF diets increase hypothalamic PTP1B and induce leptin resistance through both leptin-dependent and -independent mechanisms

    Science.gov (United States)

    White, Christy L.; Whittington, Amy; Barnes, Maria J.; Wang, Zhong; Bray, George A.; Morrison, Christopher D.

    2009-01-01

    Protein tyrosine phosphatase 1B (PTP1B) contributes to leptin resistance by inhibiting intracellular leptin receptor signaling. Mice with whole body or neuron-specific deletion of PTP1B are hypersensitive to leptin and resistant to diet-induced obesity. Here we report a significant increase in PTP1B protein levels in the mediobasal hypothalamus (P = 0.003) and a concomitant reduction in leptin sensitivity following 28 days of high-fat (HF) feeding in rats. A significant increase in PTP1B mRNA levels was also observed in rats chronically infused with leptin (3 μg/day icv) for 14 days (P = 0.01) and in leptin-deficient ob/ob mice infused with leptin (5 μg/day sc for 14 days; P = 0.003). When saline-infused ob/ob mice were placed on a HF diet for 14 days, an increase in hypothalamic PTP1B mRNA expression was detected (P = 0.001) despite the absence of circulating leptin. In addition, although ob/ob mice were much more sensitive to leptin on a low-fat (LF) diet, a reduction in this sensitivity was still observed following exposure to a HF diet. Taken together, these data indicate that hypothalamic PTP1B is specifically increased during HF diet-induced leptin resistance. This increase in PTP1B is due in part to chronic hyperleptinemia, suggesting that hyperleptinemia is one mechanism contributing to the development of leptin resistance. However, these data also indicate that leptin is not required for the increase in hypothalamic PTP1B or the development of leptin resistance. Therefore, additional, leptin-independent mechanisms must exist that increase hypothalamic PTP1B and contribute to leptin resistance. PMID:19017730

  1. Leptin differentially regulate STAT3 activation in ob/ob mouse adipose mesenchymal stem cells

    Directory of Open Access Journals (Sweden)

    Zhou Zhou

    2012-12-01

    Full Text Available Abstract Background Leptin-deficient ob/ob mice exhibit adipocyte hypertrophy and hyperplasia as well as elevated adipose tissue and systemic inflammation. Multipotent stem cells isolated from adult adipose tissue can differentiate into adipocytes ex vivo and thereby contribute toward increased adipocyte cell numbers, obesity, and inflamm ation. Currently, information is lacking regarding regulation of adipose stem cell numbers as well as leptin-induced inflammation and its signaling pathway in ob/ob mice. Methods Using leptin deficient ob/ob mice, we investigated whether leptin injection into ob/ob mice increases adipose stem cell numbers and adipose tissue inflammatory marker MCP-1 mRNA and secretion levels. We also determined leptin mediated signaling pathways in the adipose stem cells. Results We report here that adipose stem cell number is significantly increased following leptin injection in ob/ob mice and with treatment of isolated stem cells with leptin in vitro. Leptin also up-regulated MCP-1 secretion in a dose- and time-dependent manner. We further showed that increased MCP-1 mRNA levels were due to increased phosphorylation of Signal Transducer and Activator of Transcription 3 (STAT3 Ser727 but not STAT3 Tyr705 phosphorylation, suggesting differential regulation of MCP-1 gene expression under basal and leptin-stimulated conditions in adipose stem cells. Conclusions Taken together, these studies demonstrate that leptin increases adipose stem cell number and differentially activates STAT3 protein resulting in up-regulation of MCP-1 gene expression. Further studies of mechanisms mediating adipose stem cell hyperplasia and leptin signaling in obesity are warranted and may help identify novel anti-obesity target strategies.

  2. FTO is a relevant factor for the development of the metabolic syndrome in mice.

    Directory of Open Access Journals (Sweden)

    Kathrin Ikels

    Full Text Available The metabolic syndrome is a worldwide problem mainly caused by obesity. FTO was found to be a obesity-risk gene in humans and FTO deficiency in mice led to reduction in adipose tissue. Thus, FTO is an important factor for the development of obesity. Leptin-deficient mice are a well characterized model for analysing the metabolic syndrome. To determine the relevance of FTO for the development of the metabolic syndrome we analysed different parameters in combined homozygous deficient mice (Lep(ob/ob;Fto(-/-. Lep(ob/ob;Fto(-/- mice showed an improvement in analysed hallmarks of the metabolic syndrome in comparison to leptin-deficient mice wild type or heterozygous for Fto. Lep(ob/ob;Fto(-/- mice did not develop hyperglycaemia and showed an improved glucose tolerance. Furthermore, extension of beta-cell mass was prevented in Lep(ob/ob;Fto(-/-mice and accumulation of ectopic fat in the liver was reduced. In conclusion this study demonstrates that FTO deficiency has a protective effect not only on the development of obesity but also on the metabolic syndrome. Thus, FTO plays an important role in the development of metabolic disorders and is an interesting target for therapeutic agents.

  3. Effects of leptin treatment and Western diet on wheel running in selectively bred high runner mice.

    Science.gov (United States)

    Meek, Thomas H; Dlugosz, Elizabeth M; Vu, Kim T; Garland, Theodore

    2012-05-15

    The role of leptin in regulating physical activity is varied. The behavioral effects of leptin signaling depend on the type of activity and the animal's physiological state. We used mice from lines selectively bred for high voluntary wheel running to further study how leptin regulates volitional exercise. Mice from four replicate high runner (HR) lines typically run ~3-fold more revolutions per day than those from four non-selected control (C) lines. HR mice have altered dopamine function and differences from C in brain regions known to be important in leptin-mediated behavior. Furthermore, male HR mice have been found to dramatically increase running when administered Western diet, an effect possibly mediated through leptin signaling. Male mice from generation 61 (representing three HR lines and one C line) were allowed wheel access at 24 days of age and given either Western diet (high in fat and with added sucrose) or standard chow. After four weeks, Western diet significantly increased circulating leptin, insulin, C-peptide, gastric inhibitory polypeptide, and inflammatory hormone resistin concentrations in HR mice (C mice not measured). Western diet increased running in HR mice, but did not significantly affect running in C mice. During the fifth week, all mice received two days of intra-peritoneal sham injections (physiological saline) followed by three days of murine recombinant leptin injections, and then another six days of sham injections. Leptin treatment significantly decreased caloric intake (adjusted for body mass) and body mass in all groups. Wheel running significantly increased with leptin injections in HR mice (fed Western or standard diet), but was unaffected in C mice. Whether Western diet and leptin treatment stimulate wheel running in HR mice through the same physiological pathways awaits future study. These results have implications for understanding the neural and endocrine systems that control locomotor activity, food consumption, and body

  4. Ablation of the Leptin receptor in Myeloid Cells Impairs Pulmonary Clearance of Streptococcus Pneumoniae and Alveolar Macrophage Bactericidal Function.

    Science.gov (United States)

    Mancuso, Peter; Curtis, Jeffrey L; Freeman, Christine M; Peters-Golden, Marc; Weinberg, Jason B; Myers, Martin G

    2018-03-22

    Leptin is a pleiotropic hormone produced by white adipose tissue that regulates appetite and many physiologic functions including the immune response to infection. Genetic leptin deficiency in humans and mice impairs host defenses against respiratory tract infections. Since leptin deficiency is associated with obesity and other metabolic abnormalities, we generated mice that lack the leptin receptor (LepRb) in cells of the myeloid linage (LysM-LepRb-KO) to evaluate its impact in lean metabolically normal mice in a murine model of pneumococcal pneumonia. We observed higher lung and spleen bacterial burdens in LysM-LepRb-KO mice following an intratracheal challenge with S. pneumoniae. Although numbers of leukocytes recovered from bronchoalveolar lavage fluid did not differ between groups, we did observe higher levels of pulmonary IL-13 and TNFα in LysM-LepRb-KO mice 48 h post-infection. Phagocytosis and killing of ingested S. pneumoniae were also impaired in alveolar macrophages (AM)s from LysM-LepRb-KO mice in vitro, and was associated with reduced LTB4 and enhanced PGE2 synthesis in vitro. Pretreatment of AMs with LTB4 and the cyclooxygenase inhibitor, indomethacin, restored phagocytosis but not bacterial killing in vitro. These results, confirm our previous observations in leptin-deficient (ob/ob) and fasted mice, and demonstrate that decreased leptin action, as opposed to metabolic irregularities associated with obesity or starvation, are responsible for the defective host defense against pneumococcal pneumonia. They also provide novel targets for therapeutic intervention in humans with bacterial pneumonia.

  5. Early childhood BMI trajectories in monogenic obesity due to leptin, leptin receptor, and melanocortin 4 receptor deficiency.

    Science.gov (United States)

    Kohlsdorf, Katja; Nunziata, Adriana; Funcke, Jan-Bernd; Brandt, Stephanie; von Schnurbein, Julia; Vollbach, Heike; Lennerz, Belinda; Fritsch, Maria; Greber-Platzer, Susanne; Fröhlich-Reiterer, Elke; Luedeke, Manuel; Borck, Guntram; Debatin, Klaus-Michael; Fischer-Posovszky, Pamela; Wabitsch, Martin

    2018-02-27

    To evaluate whether early childhood body mass index (BMI) is an appropriate indicator for monogenic obesity. A cohort of n = 21 children living in Germany or Austria with monogenic obesity due to congenital leptin deficiency (group LEP, n = 6), leptin receptor deficiency (group LEPR, n = 6) and primarily heterozygous MC4 receptor deficiency (group MC4R, n = 9) was analyzed. A control group (CTRL) was defined that consisted of n = 22 obese adolescents with no mutation in the above mentioned genes. Early childhood (0-5 years) BMI trajectories were compared between the groups at selected time points. The LEP and LEPR group showed a tremendous increase in BMI during the first 2 years of life with all patients displaying a BMI >27 kg/m 2 (27.2-38.4 kg/m 2 ) and %BMI P95 (percentage of the 95th percentile BMI for age and sex) >140% (144.8-198.6%) at the age of 2 years and a BMI > 33 kg/m 2 (33.3-45.9 kg/m 2 ) and %BMI P95  > 184% (184.1-212.6%) at the age of 5 years. The MC4R and CTRL groups had a later onset of obesity with significantly lower BMI values at both time points (p BMI trajectories in this pediatric cohort with monogenic obesity we suggest that BMI values >27.0 kg/m 2 or %BMI P95  > 140% at the age of 2 years and BMI values >33.0 kg/m 2 or %BMI P95  > 184% at the age of 5 years may be useful cut points to identify children who should undergo genetic screening for monogenic obesity due to functionally relevant mutations in the leptin gene or leptin receptor gene.

  6. Nrf2 deficiency improves glucose tolerance in mice fed a high-fat diet

    International Nuclear Information System (INIS)

    Zhang, Yu-Kun Jennifer; Wu, Kai Connie; Liu, Jie; Klaassen, Curtis D.

    2012-01-01

    Nrf2, a master regulator of intracellular redox homeostasis, is indicated to participate in fatty acid metabolism in liver. However, its role in diet-induced obesity remains controversial. In the current study, genetically engineered Nrf2-null, wild-type (WT), and Nrf2-activated, Keap1-knockdown (K1-KD) mice were fed either a control or a high-fat Western diet (HFD) for 12 weeks. The results indicate that the absence or enhancement of Nrf2 activity did not prevent diet-induced obesity, had limited effects on lipid metabolism, but affected blood glucose homeostasis. Whereas the Nrf2-null mice were resistant to HFD-induced glucose intolerance, the Nrf2-activated K1-KD mice exhibited prolonged elevation of circulating glucose during a glucose tolerance test even on the control diet. Feeding a HFD did not activate the Nrf2 signaling pathway in mouse livers. Fibroblast growth factor 21 (Fgf21) is a liver-derived anti-diabetic hormone that exerts glucose- and lipid-lowering effects. Fgf21 mRNA and protein were both elevated in livers of Nrf2-null mice, and Fgf21 protein was lower in K1-KD mice than WT mice. The inverse correlation between Nrf2 activity and hepatic expression of Fgf21 might explain the improved glucose tolerance in Nrf2-null mice. Furthermore, a more oxidative cellular environment in Nrf2-null mice could affect insulin signaling in liver. For example, mRNA of insulin-like growth factor binding protein 1, a gene repressed by insulin in hepatocytes, was markedly elevated in livers of Nrf2-null mice. In conclusion, genetic alteration of Nrf2 does not prevent diet-induced obesity in mice, but deficiency of Nrf2 improves glucose homeostasis, possibly through its effects on Fgf21 and/or insulin signaling. -- Highlights: ► Nrf2 deficiency improves glucose tolerance in mice fed a high-fat diet. ► The anti-diabetic hormone, Fgf21, is highly expressed in livers of Nrf2-null mice. ► The absence of Nrf2 increases the insulin-regulated Igfbp-1 mRNA in liver.

  7. Nrf2 deficiency improves glucose tolerance in mice fed a high-fat diet

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yu-Kun Jennifer; Wu, Kai Connie; Liu, Jie; Klaassen, Curtis D., E-mail: cklaasse@kumc.edu

    2012-11-01

    Nrf2, a master regulator of intracellular redox homeostasis, is indicated to participate in fatty acid metabolism in liver. However, its role in diet-induced obesity remains controversial. In the current study, genetically engineered Nrf2-null, wild-type (WT), and Nrf2-activated, Keap1-knockdown (K1-KD) mice were fed either a control or a high-fat Western diet (HFD) for 12 weeks. The results indicate that the absence or enhancement of Nrf2 activity did not prevent diet-induced obesity, had limited effects on lipid metabolism, but affected blood glucose homeostasis. Whereas the Nrf2-null mice were resistant to HFD-induced glucose intolerance, the Nrf2-activated K1-KD mice exhibited prolonged elevation of circulating glucose during a glucose tolerance test even on the control diet. Feeding a HFD did not activate the Nrf2 signaling pathway in mouse livers. Fibroblast growth factor 21 (Fgf21) is a liver-derived anti-diabetic hormone that exerts glucose- and lipid-lowering effects. Fgf21 mRNA and protein were both elevated in livers of Nrf2-null mice, and Fgf21 protein was lower in K1-KD mice than WT mice. The inverse correlation between Nrf2 activity and hepatic expression of Fgf21 might explain the improved glucose tolerance in Nrf2-null mice. Furthermore, a more oxidative cellular environment in Nrf2-null mice could affect insulin signaling in liver. For example, mRNA of insulin-like growth factor binding protein 1, a gene repressed by insulin in hepatocytes, was markedly elevated in livers of Nrf2-null mice. In conclusion, genetic alteration of Nrf2 does not prevent diet-induced obesity in mice, but deficiency of Nrf2 improves glucose homeostasis, possibly through its effects on Fgf21 and/or insulin signaling. -- Highlights: ► Nrf2 deficiency improves glucose tolerance in mice fed a high-fat diet. ► The anti-diabetic hormone, Fgf21, is highly expressed in livers of Nrf2-null mice. ► The absence of Nrf2 increases the insulin-regulated Igfbp-1 mRNA in liver.

  8. The adipokine leptin increases skeletal muscle mass and significantly alters skeletal muscle miRNA expression profile in aged mice

    International Nuclear Information System (INIS)

    Hamrick, Mark W.; Herberg, Samuel; Arounleut, Phonepasong; He, Hong-Zhi; Shiver, Austin; Qi, Rui-Qun; Zhou, Li; Isales, Carlos M.

    2010-01-01

    Research highlights: → Aging is associated with muscle atrophy and loss of muscle mass, known as the sarcopenia of aging. → We demonstrate that age-related muscle atrophy is associated with marked changes in miRNA expression in muscle. → Treating aged mice with the adipokine leptin significantly increased muscle mass and the expression of miRNAs involved in muscle repair. → Recombinant leptin therapy may therefore be a novel approach for treating age-related muscle atrophy. -- Abstract: Age-associated loss of muscle mass, or sarcopenia, contributes directly to frailty and an increased risk of falls and fractures among the elderly. Aged mice and elderly adults both show decreased muscle mass as well as relatively low levels of the fat-derived hormone leptin. Here we demonstrate that loss of muscle mass and myofiber size with aging in mice is associated with significant changes in the expression of specific miRNAs. Aging altered the expression of 57 miRNAs in mouse skeletal muscle, and many of these miRNAs are now reported to be associated specifically with age-related muscle atrophy. These include miR-221, previously identified in studies of myogenesis and muscle development as playing a role in the proliferation and terminal differentiation of myogenic precursors. We also treated aged mice with recombinant leptin, to determine whether leptin therapy could improve muscle mass and alter the miRNA expression profile of aging skeletal muscle. Leptin treatment significantly increased hindlimb muscle mass and extensor digitorum longus fiber size in aged mice. Furthermore, the expression of 37 miRNAs was altered in muscles of leptin-treated mice. In particular, leptin treatment increased the expression of miR-31 and miR-223, miRNAs known to be elevated during muscle regeneration and repair. These findings suggest that aging in skeletal muscle is associated with marked changes in the expression of specific miRNAs, and that nutrient-related hormones such as leptin

  9. The adipokine leptin increases skeletal muscle mass and significantly alters skeletal muscle miRNA expression profile in aged mice

    Energy Technology Data Exchange (ETDEWEB)

    Hamrick, Mark W., E-mail: mhamrick@mail.mcg.edu [Department of Cellular Biology and Anatomy, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Department of Orthopaedic Surgery, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Herberg, Samuel; Arounleut, Phonepasong [Department of Cellular Biology and Anatomy, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Department of Orthopaedic Surgery, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); He, Hong-Zhi [Henry Ford Immunology Program, Henry Ford Health System, Detroit, MI (United States); Department of Dermatology, Henry Ford Health System, Detroit, MI (United States); Shiver, Austin [Department of Cellular Biology and Anatomy, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Department of Orthopaedic Surgery, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Qi, Rui-Qun [Henry Ford Immunology Program, Henry Ford Health System, Detroit, MI (United States); Department of Dermatology, Henry Ford Health System, Detroit, MI (United States); Zhou, Li [Henry Ford Immunology Program, Henry Ford Health System, Detroit, MI (United States); Department of Dermatology, Henry Ford Health System, Detroit, MI (United States); Department of Internal Medicine, Henry Ford Health System, Detroit, MI (United States); Isales, Carlos M. [Department of Cellular Biology and Anatomy, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); Department of Orthopaedic Surgery, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA (United States); others, and

    2010-09-24

    Research highlights: {yields} Aging is associated with muscle atrophy and loss of muscle mass, known as the sarcopenia of aging. {yields} We demonstrate that age-related muscle atrophy is associated with marked changes in miRNA expression in muscle. {yields} Treating aged mice with the adipokine leptin significantly increased muscle mass and the expression of miRNAs involved in muscle repair. {yields} Recombinant leptin therapy may therefore be a novel approach for treating age-related muscle atrophy. -- Abstract: Age-associated loss of muscle mass, or sarcopenia, contributes directly to frailty and an increased risk of falls and fractures among the elderly. Aged mice and elderly adults both show decreased muscle mass as well as relatively low levels of the fat-derived hormone leptin. Here we demonstrate that loss of muscle mass and myofiber size with aging in mice is associated with significant changes in the expression of specific miRNAs. Aging altered the expression of 57 miRNAs in mouse skeletal muscle, and many of these miRNAs are now reported to be associated specifically with age-related muscle atrophy. These include miR-221, previously identified in studies of myogenesis and muscle development as playing a role in the proliferation and terminal differentiation of myogenic precursors. We also treated aged mice with recombinant leptin, to determine whether leptin therapy could improve muscle mass and alter the miRNA expression profile of aging skeletal muscle. Leptin treatment significantly increased hindlimb muscle mass and extensor digitorum longus fiber size in aged mice. Furthermore, the expression of 37 miRNAs was altered in muscles of leptin-treated mice. In particular, leptin treatment increased the expression of miR-31 and miR-223, miRNAs known to be elevated during muscle regeneration and repair. These findings suggest that aging in skeletal muscle is associated with marked changes in the expression of specific miRNAs, and that nutrient

  10. Ciliary neurotrophic factor activates leptin-like pathways and reduces body fat, without cachexia or rebound weight gain, even in leptin-resistant obesity.

    Science.gov (United States)

    Lambert, P D; Anderson, K D; Sleeman, M W; Wong, V; Tan, J; Hijarunguru, A; Corcoran, T L; Murray, J D; Thabet, K E; Yancopoulos, G D; Wiegand, S J

    2001-04-10

    Ciliary Neurotrophic Factor (CNTF) was first characterized as a trophic factor for motor neurons in the ciliary ganglion and spinal cord, leading to its evaluation in humans suffering from motor neuron disease. In these trials, CNTF caused unexpected and substantial weight loss, raising concerns that it might produce cachectic-like effects. Countering this possibility was the suggestion that CNTF was working via a leptin-like mechanism to cause weight loss, based on the findings that CNTF acts via receptors that are not only related to leptin receptors, but also similarly distributed within hypothalamic nuclei involved in feeding. However, although CNTF mimics the ability of leptin to cause fat loss in mice that are obese because of genetic deficiency of leptin (ob/ob mice), CNTF is also effective in diet-induced obesity models that are more representative of human obesity, and which are resistant to leptin. This discordance again raised the possibility that CNTF might be acting via nonleptin pathways, perhaps more analogous to those activated by cachectic cytokines. Arguing strongly against this possibility, we now show that CNTF can activate hypothalamic leptin-like pathways in diet-induced obesity models unresponsive to leptin, that CNTF improves prediabetic parameters in these models, and that CNTF acts very differently than the prototypical cachectic cytokine, IL-1. Further analyses of hypothalamic signaling reveals that CNTF can suppress food intake without triggering hunger signals or associated stress responses that are otherwise associated with food deprivation; thus, unlike forced dieting, cessation of CNTF treatment does not result in binge overeating and immediate rebound weight gain.

  11. Leptin differentially regulates chondrogenesis in mouse vertebral and tibial growth plates.

    Science.gov (United States)

    Yu, Bo; Jiang, Kaibiao; Chen, Bin; Wang, Hantao; Li, Xinfeng; Liu, Zude

    2017-05-31

    Leptin plays an important role in mediating chondrogenesis of limb growth plate. Previous studies suggest that bone structures and development of spine and limb are different. The expression of Ob-Rb, the gene that encodes leptin receptors, is vertebral and appendicular region-specific, suggesting the regulation of leptin on VGP and TGP chondrogenesis may be very different. The aim of the present study was to investigate the differential regulation of leptin on the chondrogenesis of vertebral growth plate (VGP) and tibial growth plate (TGP). We compared the VGP and TGP from wild type (C57BL/6) and leptin-deficient (ob/ob) mice. We then generated primary cultures of TGP and VGP chondrocytes. By treating the primary cells with different concentrations of leptin in vitro, we analyzed proliferation and apoptosis of the primary chondrocytes from TGP and VGP. We further measured expression of chondrogenic-related genes in these cells that had been incubated with different doses of leptin. Leptin-deficient mice of 8-week-old had shorter tibial and longer vertebral lengths than the wide type mice. Disturbed columnar structure was observed for TGP but not for VGP. In primary chondrocyte cultures, leptin inhibited VGP chondrocyte proliferation but promoted their apoptosis. Collagen IIA and aggrecan mRNA, and the protein levels of proliferation- and chondrogenesis-related markers, including PCNA, Sox9, and Smad4, were downregulated by leptin in a dose-dependent manner. In contrast, leptin stimulated the proliferation and chondrogenic differentiation of TGP chondrocytes at physiological levels (i.e., 10 and 50 ng/mL) but not at high levels (i.e., 100 and 1000 ng/mL). Leptin exerts a stimulatory effect on the proliferation and chondrogenic differentiation of the long bone growth plate but an inhibitory effect on the spine growth plate. The ongoing study will shed light on the regulatory mechanisms of leptin in bone development and metabolism.

  12. Ageing Fxr deficient mice develop increased energy expenditure, improved glucose control and liver damage resembling NASH.

    Directory of Open Access Journals (Sweden)

    Mikael Bjursell

    Full Text Available Nuclear receptor subfamily 1, group H, member 4 (Nr1h4, FXR is a bile acid activated nuclear receptor mainly expressed in the liver, intestine, kidney and adrenal glands. Upon activation, the primary function is to suppress cholesterol 7 alpha-hydroxylase (Cyp7a1, the rate-limiting enzyme in the classic or neutral bile acid synthesis pathway. In the present study, a novel Fxr deficient mouse line was created and studied with respect to metabolism and liver function in ageing mice fed chow diet. The Fxr deficient mice were similar to wild type mice in terms of body weight, body composition, energy intake and expenditure as well as behaviours at a young age. However, from 15 weeks of age and onwards, the Fxr deficient mice had almost no body weight increase up to 39 weeks of age mainly because of lower body fat mass. The lower body weight gain was associated with increased energy expenditure that was not compensated by increased food intake. Fasting levels of glucose and insulin were lower and glucose tolerance was improved in old and lean Fxr deficient mice. However, the Fxr deficient mice displayed significantly increased liver weight, steatosis, hepatocyte ballooning degeneration and lobular inflammation together with elevated plasma levels of ALT, bilirubin and bile acids, findings compatible with non-alcoholic steatohepatitis (NASH and cholestasis. In conclusion, ageing Fxr deficient mice display late onset leanness associated with elevated energy expenditure and improved glucose control but develop severe NASH-like liver pathology.

  13. Ageing Fxr deficient mice develop increased energy expenditure, improved glucose control and liver damage resembling NASH.

    Science.gov (United States)

    Bjursell, Mikael; Wedin, Marianne; Admyre, Therése; Hermansson, Majlis; Böttcher, Gerhard; Göransson, Melker; Lindén, Daniel; Bamberg, Krister; Oscarsson, Jan; Bohlooly-Y, Mohammad

    2013-01-01

    Nuclear receptor subfamily 1, group H, member 4 (Nr1h4, FXR) is a bile acid activated nuclear receptor mainly expressed in the liver, intestine, kidney and adrenal glands. Upon activation, the primary function is to suppress cholesterol 7 alpha-hydroxylase (Cyp7a1), the rate-limiting enzyme in the classic or neutral bile acid synthesis pathway. In the present study, a novel Fxr deficient mouse line was created and studied with respect to metabolism and liver function in ageing mice fed chow diet. The Fxr deficient mice were similar to wild type mice in terms of body weight, body composition, energy intake and expenditure as well as behaviours at a young age. However, from 15 weeks of age and onwards, the Fxr deficient mice had almost no body weight increase up to 39 weeks of age mainly because of lower body fat mass. The lower body weight gain was associated with increased energy expenditure that was not compensated by increased food intake. Fasting levels of glucose and insulin were lower and glucose tolerance was improved in old and lean Fxr deficient mice. However, the Fxr deficient mice displayed significantly increased liver weight, steatosis, hepatocyte ballooning degeneration and lobular inflammation together with elevated plasma levels of ALT, bilirubin and bile acids, findings compatible with non-alcoholic steatohepatitis (NASH) and cholestasis. In conclusion, ageing Fxr deficient mice display late onset leanness associated with elevated energy expenditure and improved glucose control but develop severe NASH-like liver pathology.

  14. Irbesartan increased PPARγ activity in vivo in white adipose tissue of atherosclerotic mice and improved adipose tissue dysfunction

    International Nuclear Information System (INIS)

    Iwai, Masaru; Kanno, Harumi; Senba, Izumi; Nakaoka, Hirotomo; Moritani, Tomozo; Horiuchi, Masatsugu

    2011-01-01

    Research highlights: → Atherosclerotic apolipoprotein E-deficient (ApoEKO) mice were treated with irbesartan. → Irbesartan decreased white adipose tissue weight without affecting body weight. → DNA-binding for PPARγ was increased in white adipose tissue in vivo by irbesartan. → Irbesartan increased adipocyte number in white adipose tissue. → Irbesatan increased the expression of adiponectin and leptin in white adipose tissue. -- Abstract: The effect of the PPARγ agonistic action of an AT 1 receptor blocker, irbesartan, on adipose tissue dysfunction was explored using atherosclerotic model mice. Adult male apolipoprotein E-deficient (ApoEKO) mice at 9 weeks of age were treated with a high-cholesterol diet (HCD) with or without irbesartan at a dose of 50 mg/kg/day for 4 weeks. The weight of epididymal and retroperitoneal adipose tissue was decreased by irbesartan without changing food intake or body weight. Treatment with irbesartan increased the expression of PPARγ in white adipose tissue and the DNA-binding activity of PPARγ in nuclear extract prepared from adipose tissue. The expression of adiponectin, leptin and insulin receptor was also increased by irbesartan. These results suggest that irbesartan induced activation of PPARγ and improved adipose tissue dysfunction including insulin resistance.

  15. Behavioral changes induced by cocaine in mice are modified by a hyperlipidic diet or recombinant leptin

    Directory of Open Access Journals (Sweden)

    E. Erhardt

    2006-12-01

    Full Text Available The objective of the present study was to determine if the acute behavioral effects of cocaine acutely administered intraperitoneally (ip at doses of 5, 10 and 20 mg/kg on white male CF1 mice, 90 days of age, would be influenced by leptin acutely administered ip (at doses of 5, 10 and 20 µg/kg or by endogenous leptin production enhanced by a high-fat diet. The acute behavioral effects of cocaine were evaluated in open-field, elevated plus-maze and forced swimming tests. Results were compared between a group of 80 mice consuming a balanced diet and a high-fat diet, and a group of 80 mice fed a commercially available rodent chow formula (Ralston Purina but receiving recombinant leptin (rLeptin or saline ip. Both the high-fat-fed and rLeptin-treated mice showed decreased locomotion in the open-field test, spent more time in the open arms of the elevated plus-maze and showed less immobility time in the forced swimming test (F(1,68 = 7.834, P = 0.007. There was an interaction between diets and cocaine/saline treatments in locomotion (F(3,34 = 3.751, P = 0.020 and exploration (F(3,34 = 3.581, P = 0.024. These results suggest that anxiolytic effects and increased general activity were induced by leptin in cocaine-treated mice and that low leptin levels are associated with behavioral depression. Chronic changes in diet composition producing high leptin levels or rLeptin treatment may result in an altered response to cocaine in ethologic tests that measure degrees of anxiety and depression, which could be attributed to an antagonistic effect of leptin.

  16. Thymidine kinase 2 deficiency-induced mitochondrial DNA depletion causes abnormal development of adipose tissues and adipokine levels in mice.

    Directory of Open Access Journals (Sweden)

    Joan Villarroya

    Full Text Available Mammal adipose tissues require mitochondrial activity for proper development and differentiation. The components of the mitochondrial respiratory chain/oxidative phosphorylation system (OXPHOS are encoded by both mitochondrial and nuclear genomes. The maintenance of mitochondrial DNA (mtDNA is a key element for a functional mitochondrial oxidative activity in mammalian cells. To ascertain the role of mtDNA levels in adipose tissue, we have analyzed the alterations in white (WAT and brown (BAT adipose tissues in thymidine kinase 2 (Tk2 H126N knockin mice, a model of TK2 deficiency-induced mtDNA depletion. We observed respectively severe and moderate mtDNA depletion in TK2-deficient BAT and WAT, showing both tissues moderate hypotrophy and reduced fat accumulation. Electron microscopy revealed altered mitochondrial morphology in brown but not in white adipocytes from TK2-deficient mice. Although significant reduction in mtDNA-encoded transcripts was observed both in WAT and BAT, protein levels from distinct OXPHOS complexes were significantly reduced only in TK2-deficient BAT. Accordingly, the activity of cytochrome c oxidase was significantly lowered only in BAT from TK2-deficient mice. The analysis of transcripts encoding up to fourteen components of specific adipose tissue functions revealed that, in both TK2-deficient WAT and BAT, there was a consistent reduction of thermogenesis related gene expression and a severe reduction in leptin mRNA. Reduced levels of resistin mRNA were found in BAT from TK2-deficient mice. Analysis of serum indicated a dramatic reduction in circulating levels of leptin and resistin. In summary, our present study establishes that mtDNA depletion leads to a moderate impairment in mitochondrial respiratory function, especially in BAT, causes substantial alterations in WAT and BAT development, and has a profound impact in the endocrine properties of adipose tissues.

  17. Thymidine kinase 2 deficiency-induced mitochondrial DNA depletion causes abnormal development of adipose tissues and adipokine levels in mice.

    Science.gov (United States)

    Villarroya, Joan; Dorado, Beatriz; Vilà, Maya R; Garcia-Arumí, Elena; Domingo, Pere; Giralt, Marta; Hirano, Michio; Villarroya, Francesc

    2011-01-01

    Mammal adipose tissues require mitochondrial activity for proper development and differentiation. The components of the mitochondrial respiratory chain/oxidative phosphorylation system (OXPHOS) are encoded by both mitochondrial and nuclear genomes. The maintenance of mitochondrial DNA (mtDNA) is a key element for a functional mitochondrial oxidative activity in mammalian cells. To ascertain the role of mtDNA levels in adipose tissue, we have analyzed the alterations in white (WAT) and brown (BAT) adipose tissues in thymidine kinase 2 (Tk2) H126N knockin mice, a model of TK2 deficiency-induced mtDNA depletion. We observed respectively severe and moderate mtDNA depletion in TK2-deficient BAT and WAT, showing both tissues moderate hypotrophy and reduced fat accumulation. Electron microscopy revealed altered mitochondrial morphology in brown but not in white adipocytes from TK2-deficient mice. Although significant reduction in mtDNA-encoded transcripts was observed both in WAT and BAT, protein levels from distinct OXPHOS complexes were significantly reduced only in TK2-deficient BAT. Accordingly, the activity of cytochrome c oxidase was significantly lowered only in BAT from TK2-deficient mice. The analysis of transcripts encoding up to fourteen components of specific adipose tissue functions revealed that, in both TK2-deficient WAT and BAT, there was a consistent reduction of thermogenesis related gene expression and a severe reduction in leptin mRNA. Reduced levels of resistin mRNA were found in BAT from TK2-deficient mice. Analysis of serum indicated a dramatic reduction in circulating levels of leptin and resistin. In summary, our present study establishes that mtDNA depletion leads to a moderate impairment in mitochondrial respiratory function, especially in BAT, causes substantial alterations in WAT and BAT development, and has a profound impact in the endocrine properties of adipose tissues. © 2011 Villarroya et al.

  18. GLP-1/glucagon coagonism restores leptin responsiveness in obese mice chronically maintained on an obesogenic diet

    DEFF Research Database (Denmark)

    Clemmensen, Christoffer; Chabenne, Joseph; Finan, Brian

    2014-01-01

    We recently reported restoration of leptin responsiveness in diet-induced obese (DIO) mice using a pharmacologically optimized, polyethylene-glycolated (PEG)-leptin analog in combination with exendin-4 or FGF21. However, the return of leptin action required discontinuation of high-fat diet (HFD...... cotreatment. In summary, we report that GLP-1/glucagon coagonism restores leptin responsiveness in mice maintained on a HFD, thus emphasizing the translational value of this polypharmacotherapy for the treatment of obesity and diabetes....

  19. Meta-analysis of melanin-concentrating hormone signaling-deficient mice on behavioral and metabolic phenotypes.

    Directory of Open Access Journals (Sweden)

    Kenkichi Takase

    Full Text Available The demand for meta-analyses in basic biomedical research has been increasing because the phenotyping of genetically modified mice does not always produce consistent results. Melanin-concentrating hormone (MCH has been reported to be involved in a variety of behaviors that include feeding, body-weight regulation, anxiety, sleep, and reward behavior. However, the reported behavioral and metabolic characteristics of MCH signaling-deficient mice, such as MCH-deficient mice and MCH receptor 1 (MCHR1-deficient mice, are not consistent with each other. In the present study, we performed a meta-analysis of the published data related to MCH-deficient and MCHR1-deficient mice to obtain robust conclusions about the role of MCH signaling. Overall, the meta-analysis revealed that the deletion of MCH signaling enhanced wakefulness, locomotor activity, aggression, and male sexual behavior and that MCH signaling deficiency suppressed non-REM sleep, anxiety, responses to novelty, startle responses, and conditioned place preferences. In contrast to the acute orexigenic effect of MCH, MCH signaling deficiency significantly increased food intake. Overall, the meta-analysis also revealed that the deletion of MCH signaling suppressed the body weight, fat mass, and plasma leptin, while MCH signaling deficiency increased the body temperature, oxygen consumption, heart rate, and mean arterial pressure. The lean phenotype of the MCH signaling-deficient mice was also confirmed in separate meta-analyses that were specific to sex and background strain (i.e., C57BL/6 and 129Sv. MCH signaling deficiency caused a weak anxiolytic effect as assessed with the elevated plus maze and the open field test but also caused a weak anxiogenic effect as assessed with the emergence test. MCH signaling-deficient mice also exhibited increased plasma corticosterone under non-stressed conditions, which suggests enhanced activity of the hypothalamic-pituitary-adrenal axis. To the best of our

  20. ENU mutagenesis identifies mice with morbid obesity and severe hyperinsulinemia caused by a novel mutation in leptin.

    Directory of Open Access Journals (Sweden)

    Chen-Jee Hong

    Full Text Available BACKGROUND: Obesity is a multifactorial disease that arises from complex interactions between genetic predisposition and environmental factors. Leptin is central to the regulation of energy metabolism and control of body weight in mammals. METHODOLOGY/PRINCIPAL FINDINGS: To better recapitulate the complexity of human obesity syndrome, we applied N-ethyl-N-nitrosourea (ENU mutagenesis in combination with a set of metabolic assays in screening mice for obesity. Mapping revealed linkage to the chromosome 6 within a region containing mouse Leptin gene. Sequencing on the candidate genes identified a novel T-to-A mutation in the third exon of Leptin gene, which translates to a V145E amino acid exchange in the leptin propeptide. Homozygous Leptin(145E/145E mutant mice exhibited morbid obesity, accompanied by adipose hypertrophy, energy imbalance, and liver steatosis. This was further associated with severe insulin resistance, hyperinsulinemia, dyslipidemia, and hyperleptinemia, characteristics of human obesity syndrome. Hypothalamic leptin actions in inhibition of orexigenic peptides NPY and AgRP and induction of SOCS1 and SOCS3 were attenuated in Leptin(145E/145E mice. Administration of exogenous wild-type leptin attenuated hyperphagia and body weight increase in Leptin(145E/145E mice. However, mutant V145E leptin coimmunoprecipitated with leptin receptor, suggesting that the V145E mutation does not affect the binding of leptin to its receptor. Molecular modeling predicted that the mutated residue would form hydrogen bond with the adjacent residues, potentially affecting the structure and formation of an active complex with leptin receptor within that region. CONCLUSIONS/SIGNIFICANCE: Thus, our evolutionary, structural, and in vivo metabolic information suggests the residue 145 as of special function significance. The mouse model harboring leptin V145E mutation will provide new information on the current understanding of leptin biology and novel mouse

  1. Hormone-sensitive lipase deficiency suppresses insulin secretion from pancreatic islets of Lepob/ob mice

    International Nuclear Information System (INIS)

    Sekiya, Motohiro; Yahagi, Naoya; Tamura, Yoshiaki; Okazaki, Hiroaki; Igarashi, Masaki; Ohta, Keisuke; Takanashi, Mikio; Kumagai, Masayoshi; Takase, Satoru; Nishi, Makiko; Takeuchi, Yoshinori; Izumida, Yoshihiko; Kubota, Midori; Ohashi, Ken; Iizuka, Yoko; Yagyu, Hiroaki; Gotoda, Takanari; Nagai, Ryozo; Shimano, Hitoshi; Yamada, Nobuhiro

    2009-01-01

    It has long been a matter of debate whether the hormone-sensitive lipase (HSL)-mediated lipolysis in pancreatic β-cells can affect insulin secretion through the alteration of lipotoxicity. We generated mice lacking both leptin and HSL (Lep ob/ob /HSL -/- ) and explored the role of HSL in pancreatic β-cells in the setting of obesity. Lep ob/ob /HSL -/- developed elevated blood glucose levels and reduced plasma insulin levels compared with Lep ob/ob /HSL +/+ in a fed state, while the deficiency of HSL did not affect glucose homeostasis in Lep +/+ background. The deficiency of HSL exacerbated the accumulation of triglycerides in Lep ob/ob islets, leading to reduced glucose-stimulated insulin secretion. The deficiency of HSL also diminished the islet mass in Lep ob/ob mice due to decreased cell proliferation. In conclusion, HSL affects insulin secretary capacity especially in the setting of obesity.

  2. Long-term correction of obesity and diabetes in genetically obese mice by a single intramuscular injection of recombinant adeno-associated virus encoding mouse leptin

    Science.gov (United States)

    Murphy, John E.; Zhou, Shangzhen; Giese, Klaus; Williams, Lewis T.; Escobedo, Jaime A.; Dwarki, Varavani J.

    1997-01-01

    The ob/ob mouse is genetically deficient in leptin and exhibits a phenotype that includes obesity and non-insulin-dependent diabetes melitus. This phenotype closely resembles the morbid obesity seen in humans. In this study, we demonstrate that a single intramuscular injection of a recombinant adeno-associated virus (AAV) vector encoding mouse leptin (rAAV-leptin) in ob/ob mice leads to prevention of obesity and diabetes. The treated animals show normalization of metabolic abnormalities including hyperglycemia, insulin resistance, impaired glucose tolerance, and lethargy. The effects of a single injection have lasted through the 6-month course of the study. At all time points measured the circulating levels of leptin in the serum were similar to age-matched control C57 mice. These results demonstrate that maintenance of normal levels of leptin (2–5 ng/ml) in the circulation can prevent both the onset of obesity and associated non-insulin-dependent diabetes. Thus a single injection of a rAAV vector expressing a therapeutic gene can lead to complete and long-term correction of a genetic disorder. Our study demonstrates the long-term correction of a disease caused by a genetic defect and proves the feasibility of using rAAV-based vectors for the treatment of chronic disorders like obesity. PMID:9391128

  3. Improved muscle function and quality after diet intervention with leucine-enriched whey and antioxidants in antioxidant deficient aged mice.

    Science.gov (United States)

    van Dijk, Miriam; Dijk, Francina J; Bunschoten, Annelies; van Dartel, Dorien A M; van Norren, Klaske; Walrand, Stephane; Jourdan, Marion; Verlaan, Sjors; Luiking, Yvette

    2016-04-05

    Antioxidant (AOX) deficiencies are commonly observed in older adults and oxidative stress has been suggested to contribute to sarcopenia. Here we investigate if 1) low levels of dietary antioxidants had a negative impact on parameters of muscle mass, function and quality, and 2) to study if nutritional interventions with AOX and/or leucine-enriched whey protein could improve these muscle parameters in aged mice. 18-months-old mice were fed a casein-based antioxidant-deficient (lowox) diet or a casein-based control-diet (CTRL) for 7 months. During the last 3 months, lowox-mice were subjected to either: a) continued lowox, b) supplementation with vitamin A/E, Selenium and Zinc (AOX), c) substitution of casein with leucine-enriched whey protein (PROT) or d) a combination of both AOX and PROT (TOTAL). After 7 months lowox-mice displayed lower muscle strength and more muscle fatigue compared to CTRL. Compared to lowox-mice, PROT-mice showed improved muscle power, grip strength and less muscle fatigue. AOX-mice showed improved oxidative status, less muscle fatigue, improved grip strength and mitochondrial dynamics compared to lowox-mice. The TOTAL-mice showed the combined effects of both interventions compared to lowox-mice. In conclusion, nutritional intervention with AOX and/or leucine-enriched whey protein can play a role in improving muscle health in a AOX-deficient mouse model.

  4. Presence and distribution of leptin and leptin receptor in the canine gallbladder.

    Science.gov (United States)

    Lee, Sungin; Lee, Aeri; Kweon, Oh-Kyeong; Kim, Wan Hee

    2016-09-01

    The hormone leptin is produced by mature adipocytes and plays an important role in regulating food intake and energy metabolism through its interaction with the leptin receptor. In addition to roles in obesity and obesity-related diseases, leptin has been reported to affect the components and secretion of bile in leptin-deficient mice. Furthermore, gallbladder diseases such as cholelithiasis are known to be associated with serum leptin concentrations in humans. We hypothesized that the canine gallbladder is a source of leptin and that the leptin receptor may be localized in the gallbladder, where it plays a role in regulating the function of this organ. The aim of this study was to demonstrate the presence and expression patterns of leptin and its receptors in normal canine gallbladders using reverse transcriptase-PCR (RT-PCR) and immunohistochemistry. Clinically normal gallbladder tissue samples were obtained from four healthy beagle dogs with similar body condition scores. RT-PCR and sequencing of the amplified PCR products revealed the presence of leptin mRNA and its receptors in the gallbladder. Immunohistochemical investigations demonstrated the expression of leptin and its receptors in the luminal single columnar and tubuloalveolar glandular epithelial cells. In conclusion, the results of this study demonstrated the presence of leptin and its receptors in the gallbladders of dogs. Leptin and its receptor were both localized throughout the cytoplasm of luminal and glandular epithelial cells. These results suggested that the gallbladder is not only a source of leptin, but also a target of leptin though autocrine/paracrine mechanisms. The results of this study could increase the understanding of both the normal physiological functions of the gallbladder and the pathophysiological mechanisms of gallbladder diseases characterized by leptin system dysfunction. Copyright © 2016 The Authors. Published by Elsevier GmbH.. All rights reserved.

  5. Inhibitory effect of leptin on rosiglitazone-induced differentiation of primary adipocytes prepared from TallyHO/Jng mice

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Young; Kim, Joo Young; Sung, Yoon-Young; Jung, Won Hoon; Kim, Hee-Youn; Park, Ji Seon; Cheon, Hyae Gyeong [Medicinal Science Division, Korea Research Institute of Chemical Technology, 100 Jang-dong, Yuseong, 305-600 Daejon (Korea, Republic of); Rhee, Sang Dal, E-mail: sdrhee@krict.re.kr [Medicinal Science Division, Korea Research Institute of Chemical Technology, 100 Jang-dong, Yuseong, 305-600 Daejon (Korea, Republic of)

    2011-03-25

    Research highlights: {yields} In this study, we investigated the effects of leptin on adipocyte differentiation prepared from subcutaneous fat of TallyHo mice. {yields} Leptin inhibited the adipocytes differentiation at physiological concentration via inhibition of PPAR{gamma} expression. {yields} Inhibitors of ERK and STAT1 restored the leptin's inhibitory activity both in vitro and in vivo. -- Abstract: The effects of leptin on rosiglitazone-induced adipocyte differentiation were investigated in the primary adipocytes prepared from subcutaneous fat of TallyHO/Jng (TallyHO) mouse, a recently developed model animal for type 2 diabetes mellitus (T2DM). The treatment of leptin inhibited the rosiglitazone-induced adipocyte differentiation with a decreased expression of peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}) a key adipogenic transcription factor, both in mRNA and protein levels. Leptin (10 nM) was sufficient to inhibit the adipocyte differentiation, which seemed to come from increased expression of leptin receptor genes in the fat of TallyHO mice. The inhibition of adipogenesis by leptin was restored by the treatment of inhibitors for extracellular-signal-regulated kinase (ERK) (PD98059) and signal transducer and activator of transcription-1 (STAT1) (fludarabine). Furthermore, in vivo intraperitoneal administration of PD98059 and fludarabine increased the PPAR{gamma} expression in the subcutaneous fat of TallyHO mice. These data suggest that leptin could inhibit the PPAR{gamma} expression and adipocyte differentiation in its physiological concentration in TallyHO mice.

  6. Three months of high-fructose feeding fails to induce excessive weight gain or leptin resistance in mice.

    Directory of Open Access Journals (Sweden)

    Erik J Tillman

    Full Text Available High-fructose diets have been implicated in obesity via impairment of leptin signaling in humans and rodents. We investigated whether fructose-induced leptin resistance in mice could be used to study the metabolic consequences of fructose consumption in humans, particularly in children and adolescents. Male C57Bl/6 mice were weaned to a randomly assigned diet: high fructose, high sucrose, high fat, or control (sugar-free, low-fat. Mice were maintained on their diets for at least 14 weeks. While fructose-fed mice regularly consumed more kcal and expended more energy, there was no difference in body weight compared to control by the end of the study. Additionally, after 14 weeks, both fructose-fed and control mice displayed similar leptin sensitivity. Fructose-feeding also did not change circulating glucose, triglycerides, or free fatty acids. Though fructose has been linked to obesity in several animal models, our data fail to support a role for fructose intake through food lasting 3 months in altering of body weight and leptin signaling in mice. The lack of impact of fructose in the food of growing mice on either body weight or leptin sensitivity over this time frame was surprising, and important information for researchers interested in fructose and body weight regulation.

  7. Irbesartan increased PPAR{gamma} activity in vivo in white adipose tissue of atherosclerotic mice and improved adipose tissue dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Iwai, Masaru; Kanno, Harumi; Senba, Izumi; Nakaoka, Hirotomo; Moritani, Tomozo [Department of Molecular Cardiovascular Biology and Pharmacology, Ehime University Graduate School of Medicine, Shitsukawa, Tohon, Ehime 791-0295 (Japan); Horiuchi, Masatsugu, E-mail: horiuchi@m.ehime-u.ac.jp [Department of Molecular Cardiovascular Biology and Pharmacology, Ehime University Graduate School of Medicine, Shitsukawa, Tohon, Ehime 791-0295 (Japan)

    2011-03-04

    Research highlights: {yields} Atherosclerotic apolipoprotein E-deficient (ApoEKO) mice were treated with irbesartan. {yields} Irbesartan decreased white adipose tissue weight without affecting body weight. {yields} DNA-binding for PPAR{gamma} was increased in white adipose tissue in vivo by irbesartan. {yields} Irbesartan increased adipocyte number in white adipose tissue. {yields} Irbesatan increased the expression of adiponectin and leptin in white adipose tissue. -- Abstract: The effect of the PPAR{gamma} agonistic action of an AT{sub 1} receptor blocker, irbesartan, on adipose tissue dysfunction was explored using atherosclerotic model mice. Adult male apolipoprotein E-deficient (ApoEKO) mice at 9 weeks of age were treated with a high-cholesterol diet (HCD) with or without irbesartan at a dose of 50 mg/kg/day for 4 weeks. The weight of epididymal and retroperitoneal adipose tissue was decreased by irbesartan without changing food intake or body weight. Treatment with irbesartan increased the expression of PPAR{gamma} in white adipose tissue and the DNA-binding activity of PPAR{gamma} in nuclear extract prepared from adipose tissue. The expression of adiponectin, leptin and insulin receptor was also increased by irbesartan. These results suggest that irbesartan induced activation of PPAR{gamma} and improved adipose tissue dysfunction including insulin resistance.

  8. Leptin Suppresses Mouse Taste Cell Responses to Sweet Compounds.

    Science.gov (United States)

    Yoshida, Ryusuke; Noguchi, Kenshi; Shigemura, Noriatsu; Jyotaki, Masafumi; Takahashi, Ichiro; Margolskee, Robert F; Ninomiya, Yuzo

    2015-11-01

    Leptin is known to selectively suppress neural and behavioral responses to sweet-tasting compounds. However, the molecular basis for the effect of leptin on sweet taste is not known. Here, we report that leptin suppresses sweet taste via leptin receptors (Ob-Rb) and KATP channels expressed selectively in sweet-sensitive taste cells. Ob-Rb was more often expressed in taste cells that expressed T1R3 (a sweet receptor component) than in those that expressed glutamate-aspartate transporter (a marker for Type I taste cells) or GAD67 (a marker for Type III taste cells). Systemically administered leptin suppressed taste cell responses to sweet but not to bitter or sour compounds. This effect was blocked by a leptin antagonist and was absent in leptin receptor-deficient db/db mice and mice with diet-induced obesity. Blocking the KATP channel subunit sulfonylurea receptor 1, which was frequently coexpressed with Ob-Rb in T1R3-expressing taste cells, eliminated the effect of leptin on sweet taste. In contrast, activating the KATP channel with diazoxide mimicked the sweet-suppressing effect of leptin. These results indicate that leptin acts via Ob-Rb and KATP channels that are present in T1R3-expressing taste cells to selectively suppress their responses to sweet compounds. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  9. Cutting edge: Leptin-induced RORγt expression in CD4+ T cells promotes Th17 responses in systemic lupus erythematosus.

    Science.gov (United States)

    Yu, Yiyun; Liu, Yaoyang; Shi, Fu-Dong; Zou, Hejian; Matarese, Giuseppe; La Cava, Antonio

    2013-04-01

    Th17 CD4(+) cells promote inflammation and autoimmunity. In this study, we report that Th17 cell frequency is reduced in ob/ob mice (that are genetically deficient in the adipokine leptin) and that the administration of leptin to ob/ob mice restored Th17 cell numbers to values comparable to those found in wild-type animals. Leptin promoted Th17 responses in normal human CD4(+) T cells and in mice, both in vitro and in vivo, by inducing RORγt transcription. Leptin also increased Th17 responses in (NZB × NZW)F1 lupus-prone mice, whereas its neutralization in those autoimmune-prone mice inhibited Th17 responses. Because Th17 cells play an important role in the development and maintenance of inflammation and autoimmunity, these findings envision the possibility to modulate abnormal Th17 responses via leptin manipulation, and they reiterate the link between metabolism/nutrition and susceptibility to autoimmunity.

  10. Leptin in humans: lessons from translational research.

    Science.gov (United States)

    Blüher, Susann; Mantzoros, Christos S

    2009-03-01

    Leptin has emerged over the past decade as a key hormone in not only the regulation of food intake and energy expenditure but also in the regulation of neuroendocrine and immune function as well as the modulation of glucose and fat metabolism as shown by numerous observational and interventional studies in humans with (complete) congenital or relative leptin deficiency. These results have led to proof-of-concept studies that have investigated the effect of leptin administration in subjects with complete (congenital) leptin deficiency caused by mutations in the leptin gene as well as in humans with relative leptin deficiency, including states of lipoatrophy or negative energy balance and neuroendocrine dysfunction, as for instance seen with hypothalamic amenorrhea in states of exercise-induced weight loss. In those conditions, most neuroendocrine, metabolic, or immune disturbances can be restored by leptin administration. Leptin replacement therapy is thus a promising approach in several disease states, including congenital complete leptin deficiency, states of energy deprivation, including anorexia nervosa or milder forms of hypothalamic amenorrhea, as well as syndromes of insulin resistance seen in conditions such as congenital or acquired lipodystrophy. In contrast, states of energy excess such as garden-variety obesity are associated with hyperleptinemia that reflects either leptin tolerance or leptin resistance. For those conditions, development of leptin sensitizers is currently a focus of pharmaceutical research. This article summarizes our current understanding of leptin's role in human physiology and its potential role as a novel therapeutic option in human disease states associated with a new hormone deficiency, ie, leptin deficiency.

  11. Leptin promotes wound healing in the skin.

    Directory of Open Access Journals (Sweden)

    Susumu Tadokoro

    Full Text Available Leptin, a 16 kDa anti-obesity hormone, exhibits various physiological properties. Interestingly, skin wound healing was proven to delay in leptin-deficient ob/ob mice. However, little is known on the mechanisms of this phenomenon. In this study, we attempted to elucidate a role of leptin in wound healing of skin.Immunohistochemical analysis was performed to confirm the expression of the leptin receptor (Ob-R in human and mouse skin. Leptin was topically administered to chemical wounds created in mouse back skin along with sustained-release absorbable hydrogel. The process of wound repair was histologically observed and the area of ulceration was measured over time. The effect of leptin on the proliferation, differentiation and migration of human epidermal keratinocytes was investigated.Ob-R was expressed in epidermal cells of human and mouse skin. Topical administration of leptin significantly promoted wound healing. Histological analysis showed more blood vessels in the dermal connective tissues in the leptin-treated group. The proliferation, differentiation/function and migration of human epidermal keratinocytes were enhanced by exogenous leptin.Topically administered leptin was proven to promote wound healing in the skin by accelerating proliferation, differentiation/function and migration of epidermal keratinocytes and enhancing angiogenesis around the wounded area. These results strongly suggest that topical administration of leptin may be useful as a treatment to promote wound healing in the skin.

  12. Narrative review: the role of leptin in human physiology: emerging clinical applications.

    Science.gov (United States)

    Kelesidis, Theodore; Kelesidis, Iosif; Chou, Sharon; Mantzoros, Christos S

    2010-01-19

    Leptin is a hormone secreted by adipose tissue in direct proportion to amount of body fat. The circulating leptin levels serve as a gauge of energy stores, thereby directing the regulation of energy homeostasis, neuroendocrine function, and metabolism. Persons with congenital deficiency are obese, and treatment with leptin results in dramatic weight loss through decreased food intake and possible increased energy expenditure. However, most obese persons are resistant to the weight-reducing effects of leptin. Recent studies suggest that leptin is physiologically more important as an indicator of energy deficiency, rather than energy excess, and may mediate adaptation by driving increased food intake and directing neuroendocrine function to converse energy, such as inducing hypothalamic hypogonadism to prevent fertilization. Current studies investigate the role of leptin in weight-loss management because persons who have recently lost weight have relative leptin deficiency that may drive them to regain weight. Leptin deficiency is also evident in patients with diet- or exercise-induced hypothalamic amenorrhea and lipoatrophy. Replacement of leptin in physiologic doses restores ovulatory menstruation in women with hypothalamic amenorrhea and improves metabolic dysfunction in patients with lipoatrophy, including lipoatrophy associated with HIV or highly active antiretroviral therapy. The applications of leptin continue to grow and will hopefully soon be used therapeutically.

  13. Leptin-dependent neuronal NO signaling in the preoptic hypothalamus facilitates reproduction.

    Science.gov (United States)

    Bellefontaine, Nicole; Chachlaki, Konstantina; Parkash, Jyoti; Vanacker, Charlotte; Colledge, William; d'Anglemont de Tassigny, Xavier; Garthwaite, John; Bouret, Sebastien G; Prevot, Vincent

    2014-06-01

    The transition to puberty and adult fertility both require a minimum level of energy availability. The adipocyte-derived hormone leptin signals the long-term status of peripheral energy stores and serves as a key metabolic messenger to the neuroendocrine reproductive axis. Humans and mice lacking leptin or its receptor fail to complete puberty and are infertile. Restoration of leptin levels in these individuals promotes sexual maturation, which requires the pulsatile, coordinated delivery of gonadotropin-releasing hormone to the pituitary and the resulting surge of luteinizing hormone (LH); however, the neural circuits that control the leptin-mediated induction of the reproductive axis are not fully understood. Here, we found that leptin coordinated fertility by acting on neurons in the preoptic region of the hypothalamus and inducing the synthesis of the freely diffusible volume-based transmitter NO, through the activation of neuronal NO synthase (nNOS) in these neurons. The deletion of the gene encoding nNOS or its pharmacological inhibition in the preoptic region blunted the stimulatory action of exogenous leptin on LH secretion and prevented the restoration of fertility in leptin-deficient female mice by leptin treatment. Together, these data indicate that leptin plays a central role in regulating the hypothalamo-pituitary-gonadal axis in vivo through the activation of nNOS in neurons of the preoptic region.

  14. iPLA2β deficiency attenuates obesity and hepatic steatosis in ob/ob mice through hepatic fatty-acyl phospholipid remodeling.

    Science.gov (United States)

    Deng, Xiuling; Wang, Jiliang; Jiao, Li; Utaipan, Tanyarath; Tuma-Kellner, Sabine; Schmitz, Gerd; Liebisch, Gerhard; Stremmel, Wolfgang; Chamulitrat, Walee

    2016-05-01

    PLA2G6 or GVIA calcium-independent PLA2 (iPLA2β) is identified as one of the NAFLD modifier genes in humans, and thought to be a target for NAFLD therapy. iPLA2β is known to play a house-keeping role in phospholipid metabolism and remodeling. However, its role in NAFLD pathogenesis has not been supported by results obtained from high-fat feeding of iPLA2β-null (PKO) mice. Unlike livers of human NAFLD and genetically obese rodents, fatty liver induced by high-fat diet is not associated with depletion of hepatic phospholipids. We therefore tested whether iPLA2β could regulate obesity and hepatic steatosis in leptin-deficient mice by cross-breeding PKO with ob/ob mice to generate ob/ob-PKO mice. Here we observed an improvement in ob/ob-PKO mice with significant reduction in serum enzymes, lipids, glucose, insulin as well as improved glucose tolerance, and reduction in islet hyperplasia. The improvement in hepatic steatosis measured by liver triglycerides, fatty acids and cholesterol esters was associated with decreased expression of PPARγ and de novo lipogenesis genes, and the reversal of β-oxidation gene expression. Notably, ob/ob livers contained depleted levels of lysophospholipids and phospholipids, and iPLA2β deficiency in ob/ob-PKO livers lowers the former, but replenished the latter particularly phosphatidylethanolamine (PE) and phosphatidylcholine (PC) that contained arachidonic (AA) and docosahexaenoic (DHA) acids. Compared with WT livers, PKO livers also contained increased PE and PC containing AA and DHA. Thus, iPLA2β deficiency protected against obesity and ob/ob fatty liver which was associated with hepatic fatty-acyl phospholipid remodeling. Our results support the deleterious role of iPLA2β in severe obesity associated NAFLD. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Temporal changes in nutritional state affect hypothalamic POMC peptide levels independently of leptin in adult male mice.

    Science.gov (United States)

    Mercer, Aaron J; Stuart, Ronald C; Attard, Courtney A; Otero-Corchon, Veronica; Nillni, Eduardo A; Low, Malcolm J

    2014-04-15

    Hypothalamic proopiomelanocortin (POMC) neurons constitute a critical anorexigenic node in the central nervous system (CNS) for maintaining energy balance. These neurons directly affect energy expenditure and feeding behavior by releasing bioactive neuropeptides but are also subject to signals directly related to nutritional state such as the adipokine leptin. To further investigate the interaction of diet and leptin on hypothalamic POMC peptide levels, we exposed 8- to 10-wk-old male POMC-Discosoma red fluorescent protein (DsRed) transgenic reporter mice to either 24-48 h (acute) or 2 wk (chronic) food restriction, high-fat diet (HFD), or leptin treatment. Using semiquantitative immunofluorescence and radioimmunoassays, we discovered that acute fasting and chronic food restriction decreased the levels of adrenocorticotropic hormone (ACTH), α-melanocyte-stimulating hormone (α-MSH), and β-endorphin in the hypothalamus, together with decreased DsRed fluorescence, compared with control ad libitum-fed mice. Furthermore, acute but not chronic HFD or leptin administration selectively increased α-MSH levels in POMC fibers and increased DsRed fluorescence in POMC cell bodies. HFD and leptin treatments comparably increased circulating leptin levels at both time points, suggesting that transcription of Pomc and synthesis of POMC peptide products are not modified in direct relation to the concentration of plasma leptin. Our findings indicate that negative energy balance persistently downregulated POMC peptide levels, and this phenomenon may be partially explained by decreased leptin levels, since these changes were blocked in fasted mice treated with leptin. In contrast, sustained elevation of plasma leptin by HFD or hormone supplementation did not significantly alter POMC peptide levels, indicating that enhanced leptin signaling does not chronically increase Pomc transcription and peptide synthesis.

  16. Histidine Decarboxylase Deficiency Prevents Autoimmune Diabetes in NOD Mice

    Directory of Open Access Journals (Sweden)

    Manal Alkan

    2015-01-01

    Full Text Available Recent evidence has highlighted the role of histamine in inflammation. Since this monoamine has also been strongly implicated in the pathogenesis of type-1 diabetes, we assessed its effect in the nonobese diabetic (NOD mouse model. To this end, we used mice (inactivated knocked out for the gene encoding histidine decarboxylase, the unique histamine-forming enzyme, backcrossed on a NOD genetic background. We found that the lack of endogenous histamine in NOD HDC−/− mice decreased the incidence of diabetes in relation to their wild-type counterpart. Whereas the proportion of regulatory T and myeloid-derived suppressive cells was similar in both strains, histamine deficiency was associated with increased levels of immature macrophages, as compared with wild-type NOD mice. Concerning the cytokine pattern, we found a decrease in circulating IL-12 and IFN-γ in HDC−/− mice, while IL-6 or leptin remained unchanged, suggesting that histamine primarily modulates the inflammatory environment. Paradoxically, exogenous histamine given to NOD HDC−/− mice provided also protection against T1D. Our study supports the notion that histamine is involved in the pathogenesis of diabetes, thus providing additional evidence for its role in the regulation of the immune response.

  17. Leptin does not mediate short-term fasting-induced changes in growth hormone pulsatility but increases IGF-I in leptin deficiency states.

    Science.gov (United States)

    Chan, Jean L; Williams, Catherine J; Raciti, Patricia; Blakeman, Jennifer; Kelesidis, Theodore; Kelesidis, Iosif; Johnson, Michael L; Thorner, Michael O; Mantzoros, Christos S

    2008-07-01

    States of acute and chronic energy deficit are characterized by increased GH secretion and decreased IGF-I levels. The objective of the study was to determine whether changes in levels of leptin, a key mediator of the adaptation to starvation, regulate the GH-IGF system during energy deficit. We studied 14 healthy normal-weight men and women during three conditions: baseline fed and 72-h fasting (to induce hypoleptinemia) with administration of placebo or recombinant methionyl human leptin (r-metHuLeptin) (to reverse the fasting associated hypoleptinemia). We also studied eight normal-weight women with exercise-induced chronic energy deficit and hypothalamic amenorrhea at baseline and during 2-3 months of r-metHuLeptin treatment. GH pulsatility, IGF levels, IGF and GH binding protein (GHBP) levels were measured. During short-term energy deficit, measures of GH pulsatility and disorderliness and levels of IGF binding protein (IGFBP)-1 increased, whereas leptin, insulin, IGF-I (total and free), IGFBP-4, IGFBP-6, and GHBP decreased; r-metHuLeptin administration blunted the starvation-associated decrease of IGF-I. In chronic energy deficit, total and free IGF-I, IGFBP-6, and GHBP levels were lower, compared with euleptinemic controls; r-metHuLeptin administration had no major effect on GH pulsatility after 2 wk but increased total IGF-I levels and tended to increase free IGF-I and IGFBP-3 after 1 month. The GH/IGF system changes associated with energy deficit are largely independent of leptin deficiency. During acute energy deficit, r-metHuLeptin administration in replacement doses blunts the starvation-induced decrease of IGF-I, but during chronic energy deficit, r-metHuLeptin administration increases IGF-I and tends to increase free IGF-I and IGFBP-3.

  18. Modeling the Impact of Growth and Leptin Deficits on the Neuronal Regulation of Blood Pressure

    Science.gov (United States)

    Steinbrekera, Baiba; Roghair, Robert

    2016-01-01

    The risk of hypertension is increased by intrauterine growth restriction (IUGR) and preterm birth. In the search for modifiable etiologies for this life-threatening cardiovascular morbidity, a number of pathways have been investigated, including excessive glucocorticoid exposure, nutritional deficiency, and aberration in sex hormone levels. As a neurotrophic hormone intimately involved in cardiovascular regulation whose levels are influenced by glucocorticoids, nutritional status and sex hormones, leptin has emerged as a putative etiologic and thus therapeutic agent. As a product of maternal and late fetal adipocytes as well as the placenta, circulating leptin typically surges late in gestation and declines following delivery until the infant consumes sufficient leptin-containing breast milk or accrues sufficient leptin-secreting adipose tissue to reestablish circulating levels. The leptin deficiency seen in IUGR infants is a multifactorial manifestation of placental insufficiency, exaggerated glucocorticoid exposure and fetal adipose deficit. The preterm infant suffers from the same cascade of events, including separation from the placenta, antenatal steroid exposure and persistently underdeveloped adipose depots. Preterm infants remain leptin deficient beyond term gestation, rendering them susceptible to neurodevelopmental impairment and subsequent cardiovascular dysregulation. This pathologic pathway is efficiently modeled by placing neonatal mice into atypically large litters, thereby recapitulating the perinatal growth restriction-adult hypertension phenotype. In this model, neonatal leptin supplementation restores the physiologic leptin surge, attenuates leptin-triggered sympathetic activation in adulthood and prevents leptin- or stress-evoked hypertension. Further pathway interrogation and clinical translation are needed to fully test the therapeutic potential of perinatal leptin supplementation. PMID:27613336

  19. Acute inhibition of central c-Jun N-terminal kinase restores hypothalamic insulin signalling and alleviates glucose intolerance in diabetic mice.

    Science.gov (United States)

    Benzler, J; Ganjam, G K; Legler, K; Stöhr, S; Krüger, M; Steger, J; Tups, A

    2013-05-01

    The hypothalamus has been identified as a main insulin target tissue for regulating normal body weight and glucose metabolism. Recent observations suggest that c-Jun-N-terminal kinase (JNK)-signalling plays a crucial role in the development of obesity and insulin resistance because neuronal JNK-1 ablation in the mouse prevented high-fat diet-induced obesity (DIO) and increased energy expenditure, as well as insulin sensitivity. In the present study, we investigated whether central JNK inhibition is associated with sensitisation of hypothalamic insulin signalling in mice fed a high-fat diet for 3 weeks and in leptin-deficient mice. We determined whether i.c.v. injection of a pharmacological JNK-inhibitor (SP600125) improved impaired glucose homeostasis. By immunohistochemistry, we first observed that JNK activity was increased in the arcuate nucleus (ARC) and the ventromedial hypothalamus (VMH) in both mouse models, relative to normoglycaemic controls. This suggests that up-regulation of JNK in these regions is associated with glucose intolerance and obesity, independent of leptin levels. Acute i.c.v. injection of SP600125 ameliorated glucose tolerance within 30 min in both leptin-deficient and DIO mice. Given the acute nature of i.c.v. injections, these effects cannot be attributed to changes in food intake or energy balance. In a hypothalamic cell line, and in the ARC and VMH of leptin-deficient mice, JNK inhibition by SP600125 consistently improved impaired insulin signalling. This was determined by a reduction of phospho-insulin receptor substrate-1 [IRS-1(Ser612)] protein in a hypothalamic cell line and a decline in the number of pIRS-1(Ser612) immunoreactive cells in the ARC and VMH. Serine 612 phosphorylation of IRS-1 is assumed to negatively regulate insulin signalling. In leptin-deficient mice, in both nuclei, central inhibition of JNK increased the number of cells immunoreactive for phospho-Akt (Ser473) and phospho-GSK-3β (Ser9), which are important

  20. Weight-dependent changes of immune system in adipose tissue: Importance of leptin

    International Nuclear Information System (INIS)

    Caspar-Bauguil, S.; Cousin, B.; Andre, M.; Nibbelink, M.; Galinier, A.; Periquet, B.; Casteilla, L.; Penicaud, L.

    2006-01-01

    Ancestral lymphoid cells reside in adipose tissues, and their numbers are highly altered in obesity. Leptin, production of which is correlated to fat mass, is strongly involved in the relationships between adipose tissues and immune system. We investigated in epididymal (EPI) and inguinal (ING) fat pads to determine whether 1) lymphocyte phenotypes were correlated to the tissue weight and 2) leptin was involved in such relationships. Immunohistological analyses revealed a tight relationship between the T and NK lymphocytes of the stromal vascular fraction and adipocytes. We identified a significant negative and positive correlation between EPI weight and the percentage of NK and total T cells respectively by cytofluorometric analyses. The NK and ancestral γδ T cell contents were directly dependent of leptin since they increased significantly in high-fat (HF) diet mice but not in leptin-deficient (ob/ob) mice as compared to control. By contrast, the αβ T cell content seemed independent of leptin because their percentages increased significantly with the EPI weight whatever the type of mice (control, HF, ob/ob). The present study suggests that adipose tissues present, according to their localization, different immunological mechanisms that might be involved in the regulation of adipose cells functions and proliferations

  1. Role of Shp2 in forebrain neurons in regulating metabolic and cardiovascular functions and responses to leptin.

    Science.gov (United States)

    do Carmo, J M; da Silva, A A; Sessums, P O; Ebaady, S H; Pace, B R; Rushing, J S; Davis, M T; Hall, J E

    2014-06-01

    We examined whether deficiency of Src homology 2 containing phosphatase (Shp2) signaling in forebrain neurons alters metabolic and cardiovascular regulation under various conditions and if it attenuates the anorexic and cardiovascular effects of leptin. We also tested whether forebrain Shp2 deficiency alters blood pressure (BP) and heart rate (HR) responses to acute stress. Forebrain Shp2(-/-) mice were generated by crossing Shp2(flox/flox) mice with CamKIIα-cre mice. At 22-24 weeks of age, the mice were instrumented for telemetry for measurement of BP, HR and body temperature (BT). Oxygen consumption (VO2), energy expenditure and motor activity were monitored by indirect calorimetry. Shp2/CamKIIα-cre mice were heavier (46±3 vs 32±1 g), hyperglycemic, hyperleptinemic, hyperinsulinemic and hyperphagic compared to Shp2(flox/flox) control mice. Shp2/CamKIIα-cre mice exhibited reduced food intake responses to fasting/refeeding and impaired regulation of BT when exposed to 15 and 30 °C ambient temperatures. Despite being obese and having many features of metabolic syndrome, Shp2/CamKIIα-cre mice had similar daily average BP and HR compared to Shp2(flox/flox) mice (112±2 vs 113±1 mm Hg and 595±34 vs 650±40 b.p.m.), but exhibited increased BP and HR responses to cold exposure and acute air-jet stress test. Leptin's ability to reduce food intake and to raise BP were markedly attenuated in Shp2/CamKIIα-cre mice. These results suggest that forebrain Shp2 signaling regulates food intake, appetite responses to caloric deprivation and thermogenic control of body temperature during variations in ambient temperature. Deficiency of Shp2 signaling in the forebrain is associated with augmented cardiovascular responses to cold and acute stress but attenuated BP responses to leptin.

  2. Effects of high-fat diet and/or body weight on mammary tumor leptin and apoptosis signaling pathways in MMTV-TGF-α mice

    Science.gov (United States)

    Dogan, Soner; Hu, Xin; Zhang, Yan; Maihle, Nita J; Grande, Joseph P; Cleary, Margot P

    2007-01-01

    Introduction Obesity is a risk factor for postmenopausal breast cancer and is associated with shortened mammary tumor (MT) latency in MMTV-TGF-α mice with dietary-induced obesity. One link between obesity and breast cancer is the adipokine, leptin. Here, the focus is on diet-induced obesity and MT and mammary fat pad (MFP) leptin and apoptotic signaling proteins. Methods MMTV-TGF-α mice were fed low-fat or high-fat diets from 10 to 85 weeks of age. High-Fat mice were divided into Obesity-Prone and Obesity-Resistant groups based on final body weights. Mice were followed to assess MT development and obtain serum, MFP, and MT. Results Incidence of palpable MTs was significantly different: Obesity-Prone > Obesity-Resistant > Low-Fat. Serum leptin was significantly higher in Obesity-Prone compared with Obesity-Resistant and Low-Fat mice. Low-Fat mice had higher MFP and MT ObRb (leptin receptor) protein and Jak2 (Janus kinase 2) protein and mRNA levels in comparison with High-Fat mice regardless of body weight. Leptin (mRNA) and pSTAT3 (phosphorylated signal transducer and activator of transcription 3) (mRNA and protein) also were higher in MTs from Low-Fat versus High-Fat mice. Expression of MT and MFP pro-apoptotic proteins was higher in Low-Fat versus High-Fat mice. Conclusion These results confirm a connection between body weight and MT development and between body weight and serum leptin levels. However, diet impacts MT and MFP leptin and apoptosis signaling proteins independently of body weight. PMID:18162139

  3. CXCL14 deficiency in mice attenuates obesity and inhibits feeding behavior in a novel environment.

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    Kosuke Tanegashima

    Full Text Available BACKGROUND: CXCL14 is a chemoattractant for macrophages and immature dendritic cells. We recently reported that CXCL14-deficient (CXCL14(-/- female mice in the mixed background are protected from obesity-induced hyperglycemia and insulin resistance. The decreased macrophage infiltration into visceral adipose tissues and the increased insulin sensitivity of skeletal muscle contributed to these phenotypes. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we performed a comprehensive study for the body weight control of CXCL14(-/- mice in the C57BL/6 background. We show that both male and female CXCL14(-/- mice have a 7-11% lower body weight compared to CXCL14(+/- and CXCL14(+/+ mice in adulthood. This is mainly caused by decreased food intake, and not by increased energy expenditure or locomotor activity. Reduced body weight resulting from the CXCL14 deficiency was more pronounced in double mutant CXCL14(-/-ob/ob and CXCL14(-/-A(y mice. In the case of CXCL14(-/-A(y mice, oxygen consumption was increased compared to CXCL14(+/-A(y mice, in addition to the reduced food intake. In CXCL14(-/- mice, fasting-induced up-regulation of Npy and Agrp mRNAs in the hypothalamus was blunted. As intracerebroventricular injection of recombinant CXCL14 did not change the food intake of CXCL14(-/- mice, CXCL14 could indirectly regulate appetite. Intriguingly, the food intake of CXCL14(-/- mice was significantly repressed when mice were transferred to a novel environment. CONCLUSIONS/SIGNIFICANCE: We demonstrated that CXCL14 is involved in the body weight control leading to the fully obese phenotype in leptin-deficient or A(y mutant mice. In addition, we obtained evidence indicating that CXCL14 may play an important role in central nervous system regulation of feeding behavior.

  4. Modest phenotypic improvements in ASA-deficient mice with only one UDP-galactose:ceramide-galactosyltransferase gene

    OpenAIRE

    Franken, S; Wittke, D; Mansson, JE; D'Hooge, R; De Deyn, PP; Lüllmann-Rauch, R; Matzner, U; Gieselmann, V

    2006-01-01

    Summary Background Arylsulfatase A (ASA)-deficient mice are a model for the lysosomal storage disorder metachromatic leukodystrophy. This lipidosis is characterised by the lysosomal accumulation of the sphingolipid sulfatide. Storage of this lipid is associated with progressive demyelination. We have mated ASA-deficient mice with mice heterozygous for a non-functional allele of UDP-galactose:ceramide-galactosyltransferase (CGT). This deficiency is known to lead to a decreased synthesis of gal...

  5. Effects of obesity and exercise on testicular leptin signal transduction and testosterone biosynthesis in male mice.

    Science.gov (United States)

    Yi, Xuejie; Gao, Haining; Chen, Dequan; Tang, Donghui; Huang, Wanting; Li, Tao; Ma, Tie; Chang, Bo

    2017-04-01

    To explore the role of the testicular leptin and JAK-STAT[leptin (LEP)-JAK-STAT] pathway in testosterone biosynthesis during juvenile stages and exercise for weight loss, male C57BL/6J mice were randomly divided into normal-diet and high-fat diet groups. After 10 wk, mice in the high-fat diet-fed group were further divided randomly into obese control, obese moderate-volume exercise, and obese high-volume exercise groups. Mice in the obese moderate-volume exercise group were provided with 2 h/day, 6 days/wk swimming exercise for 8 wk, and mice in the obese high-volume exercise group underwent twice the amount of daily exercise intervention as the obese moderate-volume exercise group. The results showed that a high-fat diet causes obesity, leptin resistance, inhibition of the testicular LEP-JAK-STAT pathway, decreased mRNA and protein expression of steroidogenic factor-1, steroidogenic acute regulatory protein, and the P -450 side-chain cleavage enzyme, a decrease in the serum testosterone-to-estradiol ratio, and declines in sperm quality parameters. Both moderate and high-volume exercise were able to reduce body fat and increase the mRNA and protein expression of LEP-JAK-STAT, but only moderate exercise significantly increased the mRNA and protein expression of steroidogenic factor-1, steroidogenic acute regulatory protein, and P -450 side-chain cleavage enzyme and significantly reversed the serum testosterone-to-estradiol ratio and sperm quality parameters. These findings suggest that by impairing the testicular LEP-JAK-STAT pathway, early-stage obesity inhibits the biosynthesis of testosterone and sexual development and reduces male reproductive potential. Long-term moderate and high-volume exercise can effectively reduce body fat and improve obesity-induced abnormalities in testicular leptin signal transduction, whereas only moderate-volume exercise can reverse the negative impacts of obesity on male reproductive function. Copyright © 2017 the American

  6. Improved Insulin Sensitivity despite Increased Visceral Adiposity in Mice Deficient for the Immune Cell Transcription Factor T-bet

    Science.gov (United States)

    Stolarczyk, Emilie; Vong, Chi Teng; Perucha, Esperanza; Jackson, Ian; Cawthorne, Michael A.; Wargent, Edward T.; Powell, Nick; Canavan, James B.; Lord, Graham M.; Howard, Jane K.

    2013-01-01

    Summary Low-grade inflammation in fat is associated with insulin resistance, although the mechanisms are unclear. We report that mice deficient in the immune cell transcription factor T-bet have lower energy expenditure and increased visceral fat compared with wild-type mice, yet paradoxically are more insulin sensitive. This striking phenotype, present in young T-bet−/− mice, persisted with high-fat diet and increasing host age and was associated with altered immune cell numbers and cytokine secretion specifically in visceral adipose tissue. However, the favorable metabolic phenotype observed in T-bet-deficient hosts was lost in T-bet−/− mice also lacking adaptive immunity (T-bet−/−xRag2−/−), demonstrating that T-bet expression in the adaptive rather than the innate immune system impacts host glucose homeostasis. Indeed, adoptive transfer of T-bet-deficient, but not wild-type, CD4+ T cells to Rag2−/− mice improved insulin sensitivity. Our results reveal a role for T-bet in metabolic physiology and obesity-associated insulin resistance. PMID:23562076

  7. Circulating Irisin Levels Are Not Regulated by Nutritional Status, Obesity, or Leptin Levels in Rodents.

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    Quiñones, Mar; Folgueira, Cintia; Sánchez-Rebordelo, Estrella; Al-Massadi, Omar

    2015-01-01

    Irisin is a cleaved and secreted fragment of fibronectin type III domain containing 5 (FNDC5) that is mainly released by skeletal muscle and was proposed to mediate the beneficial effects of exercise on metabolism. In the present study we aim to investigate the regulation of the circulating levels of irisin in obese animal models (diet-induced obese (DIO) rats and leptin-deficient (ob/ob) mice), as well as the influence of nutritional status and leptin. Irisin levels were measured by Enzyme-Linked Immunosorbent Assay (ELISA) and Radioimmunoassay (RIA). Serum irisin levels remained unaltered in DIO rats and ob/ob mice. Moreover, its circulating levels were also unaffected by fasting, leptin deficiency, and exogenous leptin administration in rodents. In spite of these negative results we find a negative correlation between irisin and insulin in DIO animals and a positive correlation between irisin and glucose under short-term changes in nutritional status. Our findings indicate that serum irisin levels are not modulated by different physiological settings associated to alterations in energy homeostasis. These results suggest that in rodents circulating levels of irisin are not involved in the pathophysiology of obesity and could be unrelated to metabolic status; however, further studies should clarify its precise role in states of glucose homeostasis imbalance.

  8. Circulating Irisin Levels Are Not Regulated by Nutritional Status, Obesity, or Leptin Levels in Rodents

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    Mar Quiñones

    2015-01-01

    Full Text Available Irisin is a cleaved and secreted fragment of fibronectin type III domain containing 5 (FNDC5 that is mainly released by skeletal muscle and was proposed to mediate the beneficial effects of exercise on metabolism. In the present study we aim to investigate the regulation of the circulating levels of irisin in obese animal models (diet-induced obese (DIO rats and leptin-deficient (ob/ob mice, as well as the influence of nutritional status and leptin. Irisin levels were measured by Enzyme-Linked Immunosorbent Assay (ELISA and Radioimmunoassay (RIA. Serum irisin levels remained unaltered in DIO rats and ob/ob mice. Moreover, its circulating levels were also unaffected by fasting, leptin deficiency, and exogenous leptin administration in rodents. In spite of these negative results we find a negative correlation between irisin and insulin in DIO animals and a positive correlation between irisin and glucose under short-term changes in nutritional status. Our findings indicate that serum irisin levels are not modulated by different physiological settings associated to alterations in energy homeostasis. These results suggest that in rodents circulating levels of irisin are not involved in the pathophysiology of obesity and could be unrelated to metabolic status; however, further studies should clarify its precise role in states of glucose homeostasis imbalance.

  9. Myeloid differentiation factor 88 (MyD88-deficiency increases risk of diabetes in mice.

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    Toru Hosoi

    Full Text Available BACKGROUND: Multiple lines of evidence suggest innate immune response pathways to be involved in the development of obesity-associated diabetes although the molecular mechanism underling the disease is unknown. Recent observations suggest that saturated fatty acids can act as a ligand for toll-like receptor (TLR 4, which is thought to mediate obesity-associated insulin resistance. Myeloid differentiation factor 88 (MyD88 is an adapter protein for TLR/IL-1 receptor signaling, which is involved in the activation of inflammatory pathways. To evaluate molecular mechanisms linking obesity-associated diabetes down-stream of TLR4, we investigated physiological role of MyD88 in high-fat diet (HFD-induced obesity. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, we found MyD88-deficient mice fed a HFD had increased circulating levels of insulin, leptin and cholesterol, as well as liver dysfunction (increased induction of ALT levels, increased activation of JNK and cleavage of PARP, which were linked to the onset of severe diabetes. On the other hand, TNF-alpha would not be involved in HFD-induced diabetes in MyD88-deficient mice, because TNF-alpha level was attenuated in MyD88-deficient mice fed with HFD. CONCLUSIONS/SIGNIFICANCE: The present finding of an unexpected role for MyD88 in preventing diabetes may provide a potential novel target/strategy for treating metabolic syndrome.

  10. Effects of chronic vs. intermittent calorie restriction on mammary tumor incidence and serum adiponectin and leptin levels in MMTV-TGF-α mice at different ages

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    DOGAN, SONER; ROGOZINA, OLGA P.; LOKSHIN, ANNA E.; GRANDE, JOSEPH P.; CLEARY, MARGOT P.

    2010-01-01

    Calorie restriction prevents mammary tumor (MT) development in rodents. Usually, chronic calorie restriction (CCR) has been implemented. In contrast, intermittent calorie restriction (ICR) has been less frequently used. Recent studies indicate that when a direct comparison of the same degree of CCR vs. ICR was made using MMTV-TGF-α mice which develop MTs in the second year of life, ICR provided greater protection than CCR in delaying MT detection and reducing tumor incidence. Adiponectin and leptin are two adipocytokines secreted from adipose tissue which have opposite effects on many physiological functions, including proliferation of human breast cancer cells. A recent study indicated that a low adiponectin/leptin ratio was associated with breast cancer. We evaluated the relationship of adiponectin and leptin to MT development in MMTV-TGF-α calorie-restricted mice at several ages. Mice were enrolled at 10 weeks of age and subjected to 25% caloric reduction implemented either chronically or intermittently. Mice were euthanized at designated time points up to 74 weeks of age. Serum samples were collected to measure adiponectin and leptin concentrations. Both CCR and ICR mice had significantly reduced MT incidence. For the groups studied, serum leptin increased over time, while there was a trend for an increase in serum adiponectin levels in ad libitum and ICR mice, with no change in CCR mice between 10 and 74 weeks of age. The adiponectin/leptin ratio was significantly reduced as mice aged, but this ratio in ICR mice was significantly higher than that for ad libitum and CCR mice. No correlation was noted between serum adiponectin and leptin. These findings demonstrate that intermittent calorie restriction delays the early development of MTs. This delay was associated with reduced serum leptin levels following the restriction phases of the protocol. Additionally, serum leptin levels correlated with body weight and body fat in the groups studied. PMID:22966277

  11. Skin wound healing in MMP2-deficient and MMP2 / plasminogen double-deficient mice

    DEFF Research Database (Denmark)

    Frøssing, Signe; Rønø, Birgitte; Hald, Andreas

    2010-01-01

    -sensitive MMPs during wound healing. To address whether MMP2 is accountable for the galardin-induced healing deficiency in wildtype and Plg-deficient mice, incisional skin wounds were generated in MMP2 single-deficient mice and in MMP2/Plg double-deficient mice and followed until healed. Alternatively, tissue...... was isolated 7 days post wounding for histological and biochemical analyses. No difference was found in the time from wounding to overt gross restoration of the epidermal surface between MMP2-deficient and wildtype control littermate mice. MMP2/Plg double-deficient mice were viable and fertile, and displayed...... an unchallenged general phenotype resembling that of Plg-deficient mice, including development of rectal prolapses. MMP2/Plg double-deficient mice displayed a slight increase in the wound length throughout the healing period compared with Plg-deficient mice. However, the overall time to complete healing...

  12. Myostatin deficiency partially rescues the bone phenotype of osteogenesis imperfecta model mice.

    Science.gov (United States)

    Oestreich, A K; Carleton, S M; Yao, X; Gentry, B A; Raw, C E; Brown, M; Pfeiffer, F M; Wang, Y; Phillips, C L

    2016-01-01

    Mice with osteogenesis imperfecta (+/oim), a disorder of bone fragility, were bred to mice with muscle over growth to test whether increasing muscle mass genetically would improve bone quality and strength. The results demonstrate that femora from mice carrying both mutations have greater mechanical integrity than their +/oim littermates. Osteogenesis imperfecta is a heritable connective tissue disorder due primarily to mutations in the type I collagen genes resulting in skeletal deformity and fragility. Currently, there is no cure, and therapeutic strategies encompass the use of antiresorptive pharmaceuticals and surgical bracing, with limited success and significant potential for adverse effects. Bone, a mechanosensing organ, can respond to high mechanical loads by increasing new bone formation and altering bone geometry to withstand increased forces. Skeletal muscle is a major source of physiological loading on bone, and bone strength is proportional to muscle mass. To test the hypothesis that congenic increases in muscle mass in the osteogenesis imperfecta murine model mouse (oim) will improve their compromised bone quality and strength, heterozygous (+/oim) mice were bred to mice deficient in myostatin (+/mstn), a negative regulator of muscle growth. The resulting adult offspring were evaluated for hindlimb muscle mass, and bone microarchitecture, physiochemistry, and biomechanical integrity. +/oim mice deficient in myostatin (+/mstn +/oim) were generated and demonstrated that myostatin deficiency increased body weight, muscle mass, and biomechanical strength in +/mstn +/oim mice as compared to +/oim mice. Additionally, myostatin deficiency altered the physiochemical properties of the +/oim bone but did not alter bone remodeling. Myostatin deficiency partially improved the reduced femoral bone biomechanical strength of adult +/oim mice by increasing muscle mass with concomitant improvements in bone microarchitecture and physiochemical properties.

  13. [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3, small molecule synthetic peptide leptin mimetics, improve glycemic control in diet-induced obese (DIO) mice.

    Science.gov (United States)

    Wang, Anke; Anderson, Brian M; Novakovic, Zachary M; Grasso, Patricia

    2018-03-01

    We have previously shown that following oral delivery in dodecyl maltoside (DDM), [D-Leu-4]-OB3 and its myristic acid conjugate, MA-[D-Leu-4]-OB3, improved energy balance and glucose homeostasis in genetically obese/diabetic mouse models. More recently, we have provided immunohistochemical evidence indicating that these synthetic peptide leptin mimetics cross the blood-brain barrier and concentrate in the area of the arcuate nucleus of the hypothalamus in normal C57BL/6J and Swiss Webster mice, in genetically obese ob/ob mice, and in diet-induced obese (DIO) mice. In the present study, we describe the effects of oral delivery of [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3 on glycemic control in diet-induced (DIO) mice, a non-genetic rodent model of obesity and its associated insulin resistance, which more closely recapitulates common obesity and diabetes in humans. Male C57BL/6J and DIO mice, 17, 20, and 28 weeks of age, were maintained on a low-fat or high-fat diet and given vehicle (DDM) alone or [D-Leu-4]-OB3 or MA-[D-Leu-4]-OB3 in DDM by oral gavage for 12 or 14 days. Body weight gain, food and water intake, fasting blood glucose, oral glucose tolerance, and serum insulin levels were measured. Our data indicate that (1) [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3 restore glucose tolerance in male DIO mice maintained on a high-fat diet to levels comparable to those of non-obese C57BL/6J wild-type mice of the same age and sex maintained on a low-fat diet; and (2) the influence of [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3 on glycemic control appears to be independent of their effects on energy balance. These results suggest that [D-Leu-4]-OB3 and/or MA-[D-Leu-4]-OB3 may have application to the management of the majority of cases of common obesity in humans, a state characterized at least in part, by leptin resistance resulting from a defect in leptin transport across the blood-brain barrier. They further suggest that these small molecule synthetic peptide leptin mimetics, through their

  14. Melatonin Efficacy in Obese Leptin-Deficient Mice Heart

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    Alessandra Stacchiotti

    2017-12-01

    Full Text Available Cardiomyocytes are particularly sensitive to oxidative damage due to the link between mitochondria and sarcoplasmic reticulum necessary for calcium flux and contraction. Melatonin, important indoleamine secreted by the pineal gland during darkness, also has important cardioprotective properties. We designed the present study to define morphological and ultrastructural changes in cardiomyocytes and mainly in mitochondria of an animal model of obesity (ob/ob mice, when treated orally or not with melatonin at 100 mg/kg/day for 8 weeks (from 5 up to 13 week of life. We observed that ob/ob mice mitochondria in sub-sarcolemmal and inter-myofibrillar compartments are often devoid of cristae with an abnormally large size, which are called mega-mitochondria. Moreover, in ob/ob mice the hypertrophic cardiomyocytes expressed high level of 4hydroxy-2-nonenal (4HNE, a marker of lipid peroxidation but scarce degree of mitofusin2, indicative of mitochondrial sufferance. Melatonin oral supplementation in ob/ob mice restores mitochondrial cristae, enhances mitofusin2 expression and minimizes 4HNE and p62/SQSTM1, an index of aberrant autophagic flux. At pericardial fat level, adipose tissue depot strictly associated with myocardium infarction, melatonin reduces adipocyte hypertrophy and inversely regulates 4HNE and adiponectin expressions. In summary, melatonin might represent a safe dietary adjuvant to hamper cardiac mitochondria remodeling and the hypoxic status that occur in pre-diabetic obese mice at 13 weeks of life.

  15. Shp2 signaling in POMC neurons is important for leptin's actions on blood pressure, energy balance, and glucose regulation.

    Science.gov (United States)

    do Carmo, Jussara M; da Silva, Alexandre A; Ebaady, Sabira E; Sessums, Price O; Abraham, Ralph S; Elmquist, Joel K; Lowell, Bradford B; Hall, John E

    2014-12-15

    Previous studies showed that Src homology-2 tyrosine phosphatase (Shp2) is an important regulator of body weight. In this study, we examined the impact of Shp2 deficiency specifically in proopiomelanocortin (POMC) neurons on metabolic and cardiovascular function and on chronic blood pressure (BP) and metabolic responses to leptin. Mice with Shp2 deleted in POMC neurons (Shp2/Pomc-cre) and control mice (Shp2(flox/flox)) were implanted with telemetry probes and venous catheters for measurement of mean arterial pressure (MAP) and leptin infusion. After at least 5 days of stable control measurements, mice received leptin infusion (2 μg·kg(-1)·day(-1) iv) for 7 days. Compared with Shp2(flox/flox) controls, Shp2/Pomc-cre mice at 22 wk of age were slightly heavier (34 ± 1 vs. 31 ± 1 g) but consumed a similar amount of food (3.9 ± 0.3 vs. 3.8 ± 0.2 g/day). Leptin infusion reduced food intake in Shp2(flox/flox) mice (2.6 ± 0.5 g) and Shp2/Pomc-cre mice (3.2 ± 0.3 g). Despite decreasing food intake, leptin infusion increased MAP in control mice, whereas no significant change in MAP was observed in Shp2/Pomc-cre mice. Leptin infusion also decreased plasma glucose and insulin levels in controls (12 ± 1 to 6 ± 1 μU/ml and 142 ± 12 to 81 ± 8 mg/100 ml) but not in Shp2/Pomc-cre mice. Leptin increased V̇o2 by 16 ± 2% in controls and 7 ± 1% in Shp2/Pomc-cre mice. These results indicate that Shp2 signaling in POMC neurons contributes to the long-term BP and antidiabetic actions of leptin and may play a modest role in normal regulation of body weight. Copyright © 2014 the American Physiological Society.

  16. Leptin Signaling Is Required for Adaptive Changes in Food Intake, but Not Energy Expenditure, in Response to Different Thermal Conditions

    Science.gov (United States)

    Kaiyala, Karl J.; Ogimoto, Kayoko; Nelson, Jarrell T.; Schwartz, Michael W.; Morton, Gregory J.

    2015-01-01

    Survival of free-living animals depends on the ability to maintain core body temperature in the face of rapid and dramatic changes in their thermal environment. If food intake is not adjusted to meet the changing energy demands associated with changes of ambient temperature, a serious challenge to body energy stores can occur. To more fully understand the coupling of thermoregulation to energy homeostasis in normal animals and to investigate the role of the adipose hormone leptin to this process, comprehensive measures of energy homeostasis and core temperature were obtained in leptin-deficient ob/ob mice and their wild-type (WT) littermate controls when housed under cool (14°C), usual (22°C) or ∼ thermoneutral (30°C) conditions. Our findings extend previous evidence that WT mice robustly defend normothermia in response to either a lowering (14°C) or an increase (30°C) of ambient temperature without changes in body weight or body composition. In contrast, leptin-deficient, ob/ob mice fail to defend normothermia at ambient temperatures lower than thermoneutrality and exhibit marked losses of both body fat and lean mass when exposed to cooler environments (14°C). Our findings further demonstrate a strong inverse relationship between ambient temperature and energy expenditure in WT mice, a relationship that is preserved in ob/ob mice. However, thermal conductance analysis indicates defective heat retention in ob/ob mice, irrespective of temperature. While a negative relationship between ambient temperature and energy intake also exists in WT mice, this relationship is disrupted in ob/ob mice. Thus, to meet the thermoregulatory demands of different ambient temperatures, leptin signaling is required for adaptive changes in both energy intake and thermal conductance. A better understanding of the mechanisms coupling thermoregulation to energy homeostasis may lead to the development of new approaches for the treatment of obesity. PMID:25756181

  17. Importance of leptin signaling and signal transducer and activator of transcription-3 activation in mediating the cardiac hypertrophy associated with obesity.

    Science.gov (United States)

    Leifheit-Nestler, Maren; Wagner, Nana-Maria; Gogiraju, Rajinikanth; Didié, Michael; Konstantinides, Stavros; Hasenfuss, Gerd; Schäfer, Katrin

    2013-07-11

    The adipokine leptin and its receptor are expressed in the heart, and leptin has been shown to promote cardiomyocyte hypertrophy in vitro. Obesity is associated with hyperleptinemia and hypothalamic leptin resistance as well as an increased risk to develop cardiac hypertrophy and heart failure. However, the role of cardiac leptin signaling in mediating the cardiomyopathy associated with increased body weight is unclear, in particular, whether it develops subsequently to cardiac leptin resistance or overactivation of hypertrophic signaling pathways via elevated leptin levels. The cardiac phenotype of high-fat diet (HFD)-induced obese wildtype (WT) mice was examined and compared to age-matched genetically obese leptin receptor (LepR)-deficient (LepRdb/db) or lean WT mice. To study the role of leptin-mediated STAT3 activation during obesity-induced cardiac remodeling, mice in which tyrosine residue 1138 within LepR had been replaced with a serine (LepRS1138) were also analyzed. Obesity was associated with hyperleptinemia and elevated cardiac leptin expression in both diet-induced and genetically obese mice. Enhanced LepR and STAT3 phosphorylation levels were detected in hearts of obese WT mice, but not in those with LepR mutations. Moreover, exogenous leptin continued to induce cardiac STAT3 activation in diet-induced obese mice. Although echocardiography revealed signs of cardiac hypertrophy in all obese mice, the increase in left ventricular (LV) mass and diameter was significantly more pronounced in LepRS1138 animals. LepRS1138 mice also exhibited an increased activation of signaling proteins downstream of LepR, including Jak2 (1.8-fold), Src kinase (1.7-fold), protein kinase B (1.3-fold) or C (1.6-fold). Histological analysis of hearts revealed that the inability of leptin to activate STAT3 in LepRdb/db and LepRS1138 mice was associated with reduced cardiac angiogenesis as well as increased apoptosis and fibrosis. Our findings suggest that hearts from obese mice

  18. Obese Neuronal PPARγ Knockout Mice Are Leptin Sensitive but Show Impaired Glucose Tolerance and Fertility.

    Science.gov (United States)

    Fernandez, Marina O; Sharma, Shweta; Kim, Sun; Rickert, Emily; Hsueh, Katherine; Hwang, Vicky; Olefsky, Jerrold M; Webster, Nicholas J G

    2017-01-01

    The peroxisome-proliferator activated receptor γ (PPARγ) is expressed in the hypothalamus in areas involved in energy homeostasis and glucose metabolism. In this study, we created a deletion of PPARγ brain-knockout (BKO) in mature neurons in female mice to investigate its involvement in metabolism and reproduction. We observed that there was no difference in age at puberty onset between female BKOs and littermate controls, but the BKOs gave smaller litters when mated and fewer oocytes when ovulated. The female BKO mice had regular cycles but showed an increase in the number of cycles with prolonged estrus. The mice also had increased luteinizing hormone (LH) levels during the LH surge and histological examination showed hemorrhagic corpora lutea. The mice were challenged with a 60% high-fat diet (HFD). Metabolically, the female BKO mice showed normal body weight, glucose and insulin tolerance, and leptin levels but were protected from obesity-induced leptin resistance. The neuronal knockout also prevented the reduction in estrous cycles due to the HFD. Examination of ovarian histology showed a decrease in the number of primary and secondary follicles in both genotypes due to the HFD, but the BKO ovaries showed an increase in the number of hemorrhagic follicles. In summary, our results show that neuronal PPARγ is required for optimal female fertility but is also involved in the adverse effects of diet-induced obesity by creating leptin resistance potentially through induction of the repressor Socs3. Copyright © 2017 by the Endocrine Society.

  19. Averrhoa carambola free phenolic extract ameliorates nonalcoholic hepatic steatosis by modulating mircoRNA-34a, mircoRNA-33 and AMPK pathways in leptin receptor-deficient db/db mice.

    Science.gov (United States)

    Pang, Daorui; You, Lijun; Zhou, Lin; Li, Tong; Zheng, Bisheng; Liu, Rui Hai

    2017-12-13

    The objective of the present study is to investigate the hepatic steatosis relieving effect of Averrhoa carambola free phenolic extract (ACF) on leptin receptor-deficient (db/db) mice and elucidate the modulation hepatic lipogenesis mechanisms. The serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) assays, accompanying hematoxylin and eosin (H&E) staining, were applied to identify the alleviation of liver histopathological changes. Serum and hepatic lipid assays, combined with oil red O staining, were used to investigate the amelioration of lipid accumulation. Further assessments by quantitative real-time PCR and western blot assays were used to elucidate the suppression of the fatty acid and triglyceride (TG) synthesis mechanisms underlying ACF protection. These results indicated that ACF treatment significantly reduced the liver TG of db/db mice (p < 0.05). The mechanisms are partly through phosphorylation of AMPK α and down-regulation of SREBP-1c expression, and further down-regulation of FAS and SCD1 (p < 0.05). In addition, the expression levels of mircoRNA-34a and mircoRNA-33, which modulate this signaling pathway, were significantly down-regulated by ACF treatment (p < 0.05). Collectively, these results revealed that ACF exhibited a potent hepatic steatosis relieving effect partly by inhibiting the signal transduction of hepatic lipogenesis.

  20. Impaired LDL receptor-related protein 1 translocation correlates with improved dyslipidemia and atherosclerosis in apoE-deficient mice.

    Directory of Open Access Journals (Sweden)

    Philip L S M Gordts

    Full Text Available OBJECTIVE: Determination of the in vivo significance of LDL receptor-related protein 1 (LRP1 dysfunction on lipid metabolism and atherosclerosis development in absence of its main ligand apoE. METHODS AND RESULTS: LRP1 knock-in mice carrying an inactivating mutation in the NPxYxxL motif were crossed with apoE-deficient mice. In the absence of apoE, relative to LRP1 wild-type animals, LRP1 mutated mice showed an increased clearance of postprandial lipids despite a compromised LRP1 endocytosis rate and inefficient insulin-mediated translocation of the receptor to the plasma membrane, likely due to inefficient slow recycling of the mutated receptor. Postprandial lipoprotein improvement was explained by increased hepatic clearance of triglyceride-rich remnant lipoproteins and accompanied by a compensatory 1.6-fold upregulation of LDLR expression in hepatocytes. One year-old apoE-deficient mice having the dysfunctional LRP1 revealed a 3-fold decrease in spontaneous atherosclerosis development and a 2-fold reduction in LDL-cholesterol levels. CONCLUSION: These findings demonstrate that the NPxYxxL motif in LRP1 is important for insulin-mediated translocation and slow perinuclear endosomal recycling. These LRP1 impairments correlated with reduced atherogenesis and cholesterol levels in apoE-deficient mice, likely via compensatory LDLR upregulation.

  1. CYP2E1-dependent and leptin-mediated hepatic CD57 expression on CD8 + T cells aid progression of environment-linked nonalcoholic steatohepatitis

    International Nuclear Information System (INIS)

    Seth, Ratanesh Kumar; Das, Suvarthi; Kumar, Ashutosh; Chanda, Anindya; Kadiiska, Maria B.; Michelotti, Gregory; Manautou, Jose; Diehl, Anna Mae; Chatterjee, Saurabh

    2014-01-01

    Environmental toxins induce a novel CYP2E1/leptin signaling axis in liver. This in turn activates a poorly characterized innate immune response that contributes to nonalcoholic steatohepatitis (NASH) progression. To identify the relevant subsets of T-lymphocytes in CYP2E1-dependent, environment-linked NASH, we utilized a model of diet induced obese (DIO) mice that are chronically exposed to bromodichloromethane. Mice deficient in CYP2E1, leptin (ob/ob mice), or both T and B cells (Pfp/Rag2 double knockout (KO) mice) were used to delineate the role of each of these factors in metabolic oxidative stress-induced T cell activation. Results revealed that elevated levels of lipid peroxidation, tyrosyl radical formation, mitochondrial tyrosine nitration and hepatic leptin as a consequence of metabolic oxidative stress caused increased levels of hepatic CD57, a marker of peripheral blood lymphocytes including NKT cells. CD8 + CD57 + cytotoxic T cells but not CD4 + CD57 + cells were significantly decreased in mice lacking CYP2E1 and leptin. There was a significant increase in the levels of T cell cytokines IL-2, IL-1β, and IFN-γ in bromodichloromethane exposed DIO mice but not in mice that lacked CYP2E1, leptin or T and B cells. Apoptosis as evidenced by TUNEL assay and levels of cleaved caspase-3 was significantly lower in leptin and Pfp/Rag2 KO mice and highly correlated with protection from NASH. The results described above suggest that higher levels of oxidative stress-induced leptin mediated CD8 + CD57 + T cells play an important role in the development of NASH. It also provides a novel insight of immune dysregulation and may be a key biomarker in NASH. - Highlights: • Metabolic oxidative stress caused increased levels of hepatic CD57 expression. • CD8+ CD57+ cytotoxic T cells were decreased in mice lacking CYP2E1 and leptin. • There was a significant increase in T cell cytokines in toxin-treated mice. • Apoptosis was significantly lower in leptin and Pfp

  2. CYP2E1-dependent and leptin-mediated hepatic CD57 expression on CD8 + T cells aid progression of environment-linked nonalcoholic steatohepatitis

    Energy Technology Data Exchange (ETDEWEB)

    Seth, Ratanesh Kumar; Das, Suvarthi [Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208 (United States); Kumar, Ashutosh [Free Radical Metabolism Group, Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 (United States); Chanda, Anindya [Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208 (United States); Kadiiska, Maria B. [Free Radical Metabolism Group, Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 (United States); Michelotti, Gregory [Division of Gastroenterology, Duke University, Durham, NC 27707 (United States); Manautou, Jose [Dept. of Pharmaceutical Sciences, University of Connecticut, Storrs, CT 06269-3092 (United States); Diehl, Anna Mae [Division of Gastroenterology, Duke University, Durham, NC 27707 (United States); Chatterjee, Saurabh, E-mail: schatt@mailbox.sc.edu [Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208 (United States)

    2014-01-01

    Environmental toxins induce a novel CYP2E1/leptin signaling axis in liver. This in turn activates a poorly characterized innate immune response that contributes to nonalcoholic steatohepatitis (NASH) progression. To identify the relevant subsets of T-lymphocytes in CYP2E1-dependent, environment-linked NASH, we utilized a model of diet induced obese (DIO) mice that are chronically exposed to bromodichloromethane. Mice deficient in CYP2E1, leptin (ob/ob mice), or both T and B cells (Pfp/Rag2 double knockout (KO) mice) were used to delineate the role of each of these factors in metabolic oxidative stress-induced T cell activation. Results revealed that elevated levels of lipid peroxidation, tyrosyl radical formation, mitochondrial tyrosine nitration and hepatic leptin as a consequence of metabolic oxidative stress caused increased levels of hepatic CD57, a marker of peripheral blood lymphocytes including NKT cells. CD8 + CD57 + cytotoxic T cells but not CD4 + CD57 + cells were significantly decreased in mice lacking CYP2E1 and leptin. There was a significant increase in the levels of T cell cytokines IL-2, IL-1β, and IFN-γ in bromodichloromethane exposed DIO mice but not in mice that lacked CYP2E1, leptin or T and B cells. Apoptosis as evidenced by TUNEL assay and levels of cleaved caspase-3 was significantly lower in leptin and Pfp/Rag2 KO mice and highly correlated with protection from NASH. The results described above suggest that higher levels of oxidative stress-induced leptin mediated CD8 + CD57 + T cells play an important role in the development of NASH. It also provides a novel insight of immune dysregulation and may be a key biomarker in NASH. - Highlights: • Metabolic oxidative stress caused increased levels of hepatic CD57 expression. • CD8+ CD57+ cytotoxic T cells were decreased in mice lacking CYP2E1 and leptin. • There was a significant increase in T cell cytokines in toxin-treated mice. • Apoptosis was significantly lower in leptin and Pfp

  3. Leptin and reproduction: a review.

    Science.gov (United States)

    Moschos, Stergios; Chan, Jean L; Mantzoros, Christos S

    2002-03-01

    To review recent advances in understanding the role of leptin in the physiology and pathophysiology of reproduction, with a focus on relevant clinical situations. A MEDLINE computer search was performed to identify relevant articles. Leptin, an adipocyte hormone important in regulating energy homeostasis, interacts with the reproductive axis at multiple sites, with stimulatory effects at the hypothalamus and pituitary and inhibitory actions at the gonads. More recently, leptin has been shown to play a role in other target reproductive organs, such as the endometrium, placenta, and mammary gland, with corresponding influences on important physiologic processes such as menstruation, pregnancy, and lactation. As a marker of whether nutritional stores are adequate, leptin may act in concert with gonadotropins and the growth hormone axis to initiate the complex process of puberty. Conditions in which nutritional status is suboptimal, such as eating disorders, exercise-induced amenorrhea, and functional hypothalamic amenorrhea, are associated with low serum leptin levels; and conditions with excess energy stores or metabolic disturbances, such as obesity and polycystic ovarian syndrome, often have elevated serum or follicular fluid leptin levels, raising the possibility that relative leptin deficiency or resistance may be at least partly responsible for the reproductive abnormalities that occur with these conditions. Leptin may act as the critical link between adipose tissue and the reproductive system, indicating whether adequate energy reserves are present for normal reproductive function. Future interventional studies involving leptin administration are expected to further clarify this role of leptin and may provide new therapeutic options for the reproductive dysfunction associated with states of relative leptin deficiency or resistance.

  4. Impact of diesel exhaust exposure on the liver of mice fed on omega-3 polyunsaturated fatty acids-deficient diet.

    Science.gov (United States)

    Umezawa, Masakazu; Nakamura, Masayuki; El-Ghoneimy, Ashraf A; Onoda, Atsuto; Shaheen, Hazem M; Hori, Hiroshi; Shinkai, Yusuke; El-Sayed, Yasser S; El-Far, Ali H; Takeda, Ken

    2018-01-01

    Exposure to diesel exhaust (DE) exacerbates non-alcoholic fatty liver disease, and may systemically affect lipid metabolism. Omega-3 polyunsaturated fatty acids (n-3 PUFA) have anti-inflammatory activity and suppresses hepatic triacylglycerol accumulation, but many daily diets are deficient in this nutrient. Therefore, the effect of DE exposure in mice fed n-3 PUFA-deficient diet was investigated. Mice were fed control chow or n-3 PUFA-deficient diet for 4 weeks, then exposed to clean air or DE by inhalation for further 4 weeks. Liver histology, plasma parameters, and expression of fatty acid synthesis-related genes were evaluated. N-3 PUFA-deficient diet increased hepatic lipid droplets accumulation and expression of genes promoting fatty acid synthesis: Acaca, Acacb, and Scd1. DE further increased the plasma leptin and the expression of fatty acid synthesis-related genes: Acacb, Fasn, and Scd1. N-3 PUFA-deficient diet and DE exposure potentially enhanced hepatic fatty acid synthesis and subsequently accumulation of lipid droplets. The combination of low-dose DE exposure and intake of n-3 PUFA-deficient diet may be an additional risk factor for the incidence of non-alcoholic fatty liver disease. The present study suggests an important mechanism for preventing toxicity of DE on the liver through the incorporation of n-3 PUFAs in the diet. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. ADAM12 overexpression does not improve outcome in mice with laminin alpha2-deficient muscular dystrophy

    DEFF Research Database (Denmark)

    Guo, Ling T; Shelton, G Diane; Wewer, Ulla M

    2005-01-01

    We have recently shown that overexpression of ADAM12 results in increased muscle regeneration and significantly reduced pathology in mdx, dystrophin deficient mice. In the present study, we tested the effect of overexpressing ADAM12 in dy(W) laminin-deficient mice. dy mice have a very severe...... clinical phenotype and would be expected to benefit greatly from enhanced regeneration. We found that dy(W) mice overexpressing ADAM12 indeed have increased muscle regeneration, as evidenced by increased numbers of muscle fibers expressing fetal myosin. However, overexpression of ADAM12 had no significant...

  6. Puberty is delayed in male mice with dextran sodium sulfate colitis out of proportion to changes in food intake, body weight, and serum levels of leptin.

    Science.gov (United States)

    Deboer, Mark D; Li, Yongli

    2011-01-01

    In boys, inflammatory bowel disease often results in delayed puberty associated with decreased bone mineral density and decreased linear growth. Our goal was to investigate whether pubertal timing and levels of leptin differed between prepubertal male mice with colitis and food-restricted (FR) mice maintained at a similar weight. We induced colitis in 32-d-old male mice using dextran sodium sulfate (DSS), resulting in 10 d of worsening colitis. We followed up these mice for separation of the prepuce from the glans penis as a marker of pubertal progression. Compared with free-feeding control mice, DSS and FR mice had significantly lower weight on d 7-10 of treatment. DSS mice had later puberty than control and FR mice. DSS mice also had smaller testes, lower FSH levels, increased systemic cytokines, and increased colonic inflammation by histology. Leptin levels were similar between DSS and FR mice, whereas both had decreases in leptin compared with controls. We conclude that DSS colitis causes delayed puberty in sexually immature male mice beyond what is seen among FR mice of similar weight, food intake, and leptin levels. These experiments provide support for the hypothesis that pubertal delay in colitis is influenced by factors beyond poor weight gain alone.

  7. Neuropeptide Y deficiency attenuates responses to fasting and high-fat diet in obesity-prone mice.

    Science.gov (United States)

    Patel, Hiralben R; Qi, Yong; Hawkins, Evan J; Hileman, Stanley M; Elmquist, Joel K; Imai, Yumi; Ahima, Rexford S

    2006-11-01

    Neuropeptide Y (NPY) stimulates feeding and weight gain, but deletion of the NPY gene does not affect food intake and body weight in mice bred on a mixed genetic background. We reasoned that the orexigenic action of NPY would be evident in C57Bl/6J mice susceptible to obesity. NPY deficiency has no significant effect in mice fed a normal rodent diet. However, energy expenditure is elevated during fasting, and hyperphagia and weight gain are blunted during refeeding. Expression of agouti-related peptide (AGRP) in the hypothalamus is increased in NPY knockout (NPYko) than wild-type mice, but unlike wild type there is no further increase in AGRP when NPYko mice are fasted. Moreover, NPYko mice have higher oxygen consumption and uncoupling protein-1 expression in brown adipose tissue during fasting. The failure of an increase in orexigenic peptides and higher thermogenesis may contribute to attenuation of weight gain when NPYko mice are refed. C57Bl/6J mice lacking NPY are also less susceptible to diet-induced obesity (DIO) as a result of reduced feeding and increased energy expenditure. The resistance to DIO in NPYko mice is associated with a reduction in nocturnal feeding and increased expression of anorexigenic hypothalamic peptides. Insulin, leptin, and triglyceride levels increase with adiposity in both wild-type and NPYko mice.

  8. Leptin, immune responses and autoimmune disease. Perspectives on the use of leptin antagonists.

    Science.gov (United States)

    Peelman, F; Iserentant, H; Eyckerman, S; Zabeau, L; Tavernier, J

    2005-01-01

    The pivotal role of leptin in regulating body weight and energy homeostasis is very well established. More recently, leptin also emerged as an important regulator of T-cell-dependent immunity. Reduced leptin levels, as observed during periods of starvation, correlate with an impaired cellular immune response, whereby especially the T(H)1 pro-inflammatory immune response appears to be affected. Physiologically, this could reflect the high energy demand of such processes, which are suppressed in animals or people with nutrient shortage. Several autoimmune diseases are T(H)1 T-cell dependent. In line with a pro-inflammatory role for leptin, animal models of leptin deficiency are markedly resistant to a variety of T-cell dependent autoimmune diseases. Here, we review the role of leptin in immune responses, with emphasis on autoimmune diseases. The design and potential use of leptin antagonists is also discussed.

  9. Anaplerotic Triheptanoin Diet Enhances Mitochondrial Substrate Use to Remodel the Metabolome and Improve Lifespan, Motor Function, and Sociability in MeCP2-Null Mice

    Science.gov (United States)

    Li, Qun; Degano, Alicia L.; Penati, Judith; Zhuo, Justin; Roe, Charles R.; Ronnett, Gabriele V.

    2014-01-01

    Rett syndrome (RTT) is an autism spectrum disorder (ASD) caused by mutations in the X-linked MECP2 gene that encodes methyl-CpG binding protein 2 (MeCP2). Symptoms range in severity and include psychomotor disabilities, seizures, ataxia, and intellectual disability. Symptom onset is between 6-18 months of age, a critical period of brain development that is highly energy-dependent. Notably, patients with RTT have evidence of mitochondrial dysfunction, as well as abnormal levels of the adipokines leptin and adiponectin, suggesting overall metabolic imbalance. We hypothesized that one contributor to RTT symptoms is energy deficiency due to defective nutrient substrate utilization by the TCA cycle. This energy deficit would lead to a metabolic imbalance, but would be treatable by providing anaplerotic substrates to the TCA cycle to enhance energy production. We show that dietary therapy with triheptanoin significantly increased longevity and improved motor function and social interaction in male mice hemizygous for Mecp2 knockout. Anaplerotic therapy in Mecp2 knockout mice also improved indicators of impaired substrate utilization, decreased adiposity, increased glucose tolerance and insulin sensitivity, decreased serum leptin and insulin, and improved mitochondrial morphology in skeletal muscle. Untargeted metabolomics of liver and skeletal muscle revealed increases in levels of TCA cycle intermediates with triheptanoin diet, as well as normalizations of glucose and fatty acid biochemical pathways consistent with the improved metabolic phenotype in Mecp2 knockout mice on triheptanoin. These results suggest that an approach using dietary supplementation with anaplerotic substrate is effective in improving symptoms and metabolic health in RTT. PMID:25299635

  10. Obese mice on a high-fat alternate-day fasting regimen lose weight and improve glucose tolerance.

    Science.gov (United States)

    Joslin, P M N; Bell, R K; Swoap, S J

    2017-10-01

    Alternate-day fasting (ADF) causes body weight (BW) loss in humans and rodents. However, it is not clear that ADF while maintaining a high-fat (HF) diet results in weight loss and the accompanying improvement in control of circulating glucose. We tested the hypotheses that a high-fat ADF protocol in obese mice would result in (i) BW loss, (ii) improved glucose control, (iii) fluctuating phenotypes on 'fasted' days when compared to 'fed' days and (iv) induction of torpor on 'fasted days'. We evaluated the physiological effects of ADF in diet-induced obese mice for BW, heart rate (HR), body temperature (T b ), glucose tolerance, insulin responsiveness, blood parameters (leptin, insulin, free fatty acids) and hepatic gene expression. Diet-induced obese male C57BL/6J mice lost one-third of their pre-diet BW while on an ADF diet for 10 weeks consisting of HF food. The ADF protocol improved glucose tolerance and insulin sensitivity, although mice on a fast day were less glucose tolerant than the same mice on a fed day. ADF mice on a fast day had low circulating insulin, but had an enhanced response to an insulin-assisted glucose tolerance test, suggesting the impaired glucose tolerance may be a result of insufficient insulin production. On fed days, ADF mice were the warmest, had a high HR and displayed hepatic gene expression and circulating leptin that closely mimicked that of mice fed an ad lib HF diet. ADF mice never entered torpor as assessed by HR and T b . However, on fast days, they were the coolest, had the slowest HR, and displayed hepatic gene expression and circulating leptin that closely mimicked that of Chow-Fed mice. Collectively, the ADF regimen with a HF diet in obese mice results in weight loss, improved blood glucose control, and daily fluctuations in selected physiological and biochemical parameters in the mouse. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

  11. 20 years of leptin: leptin and reproduction: past milestones, present undertakings, and future endeavors.

    Science.gov (United States)

    Chehab, Farid F

    2014-10-01

    The association between leptin and reproduction originated with the leptin-mediated correction of sterility in ob/ob mice and initiation of reproductive function in normal female mice. The uncovering of a central leptin pathway regulating food intake prompted the dissection of neuroendocrine mechanisms involving leptin in the metabolic control of reproduction. The absence of leptin receptors on GnRH neurons incited a search for intermediary neurons situated between leptin-responsive and GnRH neurons. This review addresses the most significant findings that have furthered our understanding of recent progress in this new field. The role of leptin in puberty was impacted by the discovery of neurons that co-express kisspeptin, neurokinin B, and dynorphin and these could act as leptin intermediates. Furthermore, the identification of first-order leptin-responsive neurons in the premammilary ventral nucleus and other brain regions opens new avenues to explore their relationship to GnRH neurons. Central to these advances is the unveiling that agouti-related protein/neuropeptide Y neurons project onto GnRH and kisspeptin neurons, allowing for a crosstalk between food intake and reproduction. Finally, while puberty is a state of leptin sensitivity, mid-gestation represents a state of leptin resistance aimed at building energy stores to sustain pregnancy and lactation. The mechanisms underlying leptin resistance in pregnancy have lagged; however, the establishment of this natural state is significant. Reproduction and energy balance are tightly controlled and backed up by redundant mechanisms that are critical for the survival of our species. It will be the goal of the following decade to shed new light on these complex and essential pathways. © 2014 Society for Endocrinology.

  12. Deletion of protein tyrosine phosphatase 1b in proopiomelanocortin neurons reduces neurogenic control of blood pressure and protects mice from leptin- and sympatho-mediated hypertension.

    Science.gov (United States)

    Bruder-Nascimento, Thiago; Butler, Benjamin R; Herren, David J; Brands, Michael W; Bence, Kendra K; Belin de Chantemèle, Eric J

    2015-12-01

    Protein tyrosine phosphatase 1b (Ptp1b), which represses leptin signaling, is a promising therapeutic target for obesity. Genome wide deletion of Ptp1b, increases leptin sensitivity, protects mice from obesity and diabetes, but alters cardiovascular function by increasing blood pressure (BP). Leptin-control of metabolism is centrally mediated and involves proopiomelanocortin (POMC) neurons. Whether these neurons contribute to leptin-mediated increases in BP remain unclear. We hypothesized that increasing leptin signaling in POMC neurons with Ptp1b deletion will sensitize the cardiovascular system to leptin and enhance neurogenic control of BP. We analyzed the cardiovascular phenotype of Ptp1b+/+ and POMC-Ptp1b-/- mice, at baseline and after 7 days of leptin infusion or sympatho-activation with phenylephrine. POMCPtp1b deletion did not alter baseline cardiovascular hemodynamics (BP, heart rate) but reduced BP response to ganglionic blockade and plasma catecholamine levels that suggests a decreased neurogenic control of BP. In contrast, POMC-Ptp1b deletion increased vascular adrenergic reactivity and aortic α-adrenergic receptors expression. Chronic leptin treatment reduced vascular adrenergic reactivity and blunted diastolic and mean BP increases in POMC-Ptp1b-/- mice only. Similarly POMC-Ptp1b-/- mice exhibited a blunted increased in diastolic and mean BP accompanied by a gradual reduction in adrenergic reactivity in response to chronic vascular sympatho-activation with phenylephrine. Together these data rule out our hypothesis but suggest that deletion of Ptp1b in POMC neurons protects from leptin- and sympatho-mediated increases in BP. Vascular adrenergic desensitization appears as a protective mechanism against hypertension, and POMC-Ptp1b as a key therapeutic target for the treatment of metabolic and cardiovascular dysfunctions associated with obesity. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. [Role of leptin in human reproduction (anorexia, bulimia)].

    Science.gov (United States)

    Pilka, L; Rumpík, D; Pilka, R

    2012-12-01

    Leptin may act as the critical link between adipose tissue and the reproductive system, indicating whether adequate energy reserves are presenting for normal reproductive functions. Future interventional studies involving leptin administration are excepted to further clarify this role of leptin and may provide new therapeutic options for the reproductive dysfunctions associated with states of relative leptin deficiency or resistance.

  14. Intermittent hypoxia increases insulin resistance in genetically obese mice.

    Science.gov (United States)

    Polotsky, Vsevolod Y; Li, Jianguo; Punjabi, Naresh M; Rubin, Arnon E; Smith, Philip L; Schwartz, Alan R; O'Donnell, Christopher P

    2003-10-01

    Obstructive sleep apnoea, a syndrome that leads to recurrent intermittent hypoxia, is associated with insulin resistance in obese individuals, but the mechanisms underlying this association remain unknown. We utilized a mouse model to examine the effects of intermittent hypoxia on insulin resistance in lean C57BL/6J mice and leptin-deficient obese (C57BL/6J-Lepob) mice. In lean mice, exposure to intermittent hypoxia for 5 days (short term) resulted in a decrease in fasting blood glucose levels (from 173 +/- 11 mg dl-1 on day 0 to 138 +/- 10 mg dl-1 on day 5, P obese mice, short-term intermittent hypoxia led to a decrease in blood glucose levels accompanied by a 607 +/- 136 % (P intermittent hypoxia was completely abolished by prior leptin infusion. Obese mice exposed to intermittent hypoxia for 12 weeks (long term) developed a time-dependent increase in fasting serum insulin levels (from 3.6 +/- 1.1 ng ml-1 at baseline to 9.8 +/- 1.8 ng ml-1 at week 12, P intermittent hypoxia is dependent on the disruption of leptin pathways.

  15. Reanalysis of parabiosis of obesity mutants in the age of leptin.

    Science.gov (United States)

    Zeng, Wenwen; Lu, Yi-Hsueh; Lee, Jonah; Friedman, Jeffrey M

    2015-07-21

    In this study we set out to explain the differing effects of parabiosis with genetically diabetic (db) mice versus administration of recombinant leptin. Parabiosis of db mutant, which overexpress leptin, to wildtype (WT) or genetically obese (ob) mice has been reported to cause death by starvation, whereas leptin infusions do not produce lethality at any dose or mode of delivery tested. Leptin is not posttranslationally modified other than a single disulphide bond, raising the possibility that it might require additional factor(s) to exert the maximal appetite-suppressing effect. We reconfirmed the lethal effect of parabiosis of db mutant on WT mice and further showed that this lethality could not be rescued by administration of ghrelin or growth hormone. We then initiated a biochemical fractionation of a high-molecular-weight leptin complex from human plasma and identified clusterin as a major component of this leptin-containing complex. However, in contrast to previous reports, we failed to observe a leptin-potentiating effect of either exogenous or endogenous clusterin, and parabiosis of db clusterin(-/-) double-mutant to WT mice still caused lethality. Intriguingly, in parabiotic pairs of two WT mice, leptin infusion into one of the mice led to an enhanced starvation response during calorie restriction as evidenced by increased plasma ghrelin and growth-hormone levels. Moreover, leptin treatment resulted in death of the parabiotic pairs. These data suggest that the appetite suppression in WT mice after parabiosis to db mutants is the result of induced hyperleptinemia combined with the stress or other aspect(s) of the parabiosis procedure.

  16. Hyperleptinemia is required for the development of leptin resistance.

    Directory of Open Access Journals (Sweden)

    Zachary A Knight

    2010-06-01

    Full Text Available Leptin regulates body weight by signaling to the brain the availability of energy stored as fat. This negative feedback loop becomes disrupted in most obese individuals, resulting in a state known as leptin resistance. The physiological causes of leptin resistance remain poorly understood. Here we test the hypothesis that hyperleptinemia is required for the development of leptin resistance in diet-induced obese mice. We show that mice whose plasma leptin has been clamped to lean levels develop obesity in response to a high-fat diet, and the magnitude of this obesity is indistinguishable from wild-type controls. Yet these obese animals with constant low levels of plasma leptin remain highly sensitive to exogenous leptin even after long-term exposure to a high fat diet. This shows that dietary fats alone are insufficient to block the response to leptin. The data also suggest that hyperleptinemia itself can contribute to leptin resistance by downregulating cellular response to leptin as has been shown for other hormones.

  17. Neuronal Rap1 Regulates Energy Balance, Glucose Homeostasis, and Leptin Actions

    Directory of Open Access Journals (Sweden)

    Kentaro Kaneko

    2016-09-01

    Full Text Available The CNS contributes to obesity and metabolic disease; however, the underlying neurobiological pathways remain to be fully established. Here, we show that the small GTPase Rap1 is expressed in multiple hypothalamic nuclei that control whole-body metabolism and is activated in high-fat diet (HFD-induced obesity. Genetic ablation of CNS Rap1 protects mice from dietary obesity, glucose imbalance, and insulin resistance in the periphery and from HFD-induced neuropathological changes in the hypothalamus, including diminished cellular leptin sensitivity and increased endoplasmic reticulum (ER stress and inflammation. Furthermore, pharmacological inhibition of CNS Rap1 signaling normalizes hypothalamic ER stress and inflammation, improves cellular leptin sensitivity, and reduces body weight in mice with dietary obesity. We also demonstrate that Rap1 mediates leptin resistance via interplay with ER stress. Thus, neuronal Rap1 critically regulates leptin sensitivity and mediates HFD-induced obesity and hypothalamic pathology and may represent a potential therapeutic target for obesity treatment.

  18. Short-Term High-Fat Diet Increases Leptin Activation of CART Neurons and Advances Puberty in Female Mice.

    Science.gov (United States)

    Venancio, Jade Cabestre; Margatho, Lisandra Oliveira; Rorato, Rodrigo; Rosales, Roberta Ribeiro Costa; Debarba, Lucas Kniess; Coletti, Ricardo; Antunes-Rodrigues, Jose; Elias, Carol F; Elias, Lucila Leico K

    2017-11-01

    Leptin is a permissive factor for puberty initiation, participating as a metabolic cue in the activation of the kisspeptin (Kiss1)-gonadotropin-releasing hormone neuronal circuitry; however, it has no direct effect on Kiss1 neurons. Leptin acts on hypothalamic cocaine- and amphetamine-regulated transcript (CART) neurons, participating in the regulation of energy homeostasis. We investigated the influence of a short-term high-fat diet (HFD) on the effect of leptin on puberty timing. Kiss1-hrGFP female mice received a HFD or regular diet (RD) after weaning at postnatal day (PN)21 and were studied at PN28 and PN32. The HFD increased body weight and plasma leptin concentrations and decreased the age at vaginal opening (HFD, 32 ± 0.53 days; RD, 38 ± 0.67 days). Similar colocalization of neurokinin B and dynorphin in Kiss1-hrGFP neurons of the arcuate nucleus (ARC) was observed between the HFD and RD groups. The HFD increased CART expression in the ARC and Kiss1 messenger RNA expression in the anteroventral periventricular (AVPV)/anterior periventricular (Pe). The HFD also increased the number of ARC CART neurons expressing leptin-induced phosphorylated STAT3 (signal transducer and activator of transcription 3) at PN32. Close apposition of CART fibers to Kiss1-hrGFP neurons was observed in the ARC of both RD- and HFD-fed mice. In conclusion, these data reinforce the notion that a HFD increases kisspeptin expression in the AVPV/Pe and advances puberty initiation. Furthermore, we have demonstrated that the HFD-induced earlier puberty is associated with an increase in CART expression in the ARC. Therefore, these data indicate that CART neurons in the ARC can mediate the effect of leptin on Kiss1 neurons in early puberty induced by a HFD. Copyright © 2017 Endocrine Society.

  19. Gender affects skin wound healing in plasminogen deficient mice.

    Directory of Open Access Journals (Sweden)

    Birgitte Rønø

    Full Text Available The fibrinolytic activity of plasmin plays a fundamental role in resolution of blood clots and clearance of extravascular deposited fibrin in damaged tissues. These vital functions of plasmin are exploited by malignant cells to accelerate tumor growth and facilitate metastases. Mice lacking functional plasmin thus display decreased tumor growth in a variety of cancer models. Interestingly, this role of plasmin has, in regard to skin cancer, been shown to be restricted to male mice. It remains to be clarified whether gender also affects other phenotypic characteristics of plasmin deficiency or if this gender effect is restricted to skin cancer. To investigate this, we tested the effect of gender on plasmin dependent immune cell migration, accumulation of hepatic fibrin depositions, skin composition, and skin wound healing. Gender did not affect immune cell migration or hepatic fibrin accumulation in neither wildtype nor plasmin deficient mice, and the existing differences in skin composition between males and females were unaffected by plasmin deficiency. In contrast, gender had a marked effect on the ability of plasmin deficient mice to heal skin wounds, which was seen as an accelerated wound closure in female versus male plasmin deficient mice. Further studies showed that this gender effect could not be reversed by ovariectomy, suggesting that female sex-hormones did not mediate the accelerated skin wound healing in plasmin deficient female mice. Histological examination of healed wounds revealed larger amounts of fibrotic scars in the provisional matrix of plasmin deficient male mice compared to female mice. These fibrotic scars correlated to an obstruction of cell infiltration of the granulation tissue, which is a prerequisite for wound healing. In conclusion, the presented data show that the gender dependent effect of plasmin deficiency is tissue specific and may be secondary to already established differences between genders, such as skin

  20. Studies on leptin utilizing to obesity

    International Nuclear Information System (INIS)

    Zhao Minghui

    2001-01-01

    Leptin is a hormone synthesized and secreted by lipid cells. It is a product encoded and expressed by the obese gene. Administration of recombinant leptin decreases food intake, increases energy expenditure and promotes weight loss. Most studies indicate that leptin is a main regulating factor of catabolism and anabolism of adipose tissue. The circulating leptin level is a sensitive index which indicates the confusion of the rate of lipid metabolism such as hyperlipemia, lipo-liver and so on. The human leptin radioimmunoassay has been developed to quantitate human leptin in plasma or serum, and to further investigate the relationship between serum leptin concentration and body fat, gender, age, sexual hormones, endocrine of insulin, etc. Especially, serum leptin concentrations are correlated with body-mass-index (BMI), suggesting that most obese persons are resistant to leptin; Those who are relatively deficient of leptin may become the good candidates of leptin treatment in the future. The discovery and application of leptin make the study of obesity, non-insulin dependent diabetes and other correlation diseases enter a new stage

  1. Chronic sleep fragmentation during the sleep period induces hypothalamic endoplasmic reticulum stress and PTP1b-mediated leptin resistance in male mice.

    Science.gov (United States)

    Hakim, Fahed; Wang, Yang; Carreras, Alba; Hirotsu, Camila; Zhang, Jing; Peris, Eduard; Gozal, David

    2015-01-01

    Sleep fragmentation (SF) is highly prevalent and may constitute an important contributing factor to excessive weight gain and the metabolic syndrome. Increased endoplasmic reticulum (ER) stress and activation of the unfolded protein response (UPR) leading to the attenuation of leptin receptor signaling in the hypothalamus leads to obesity and metabolic dysfunction. Mice were exposed to SF and sleep control (SC) for varying periods of time during which ingestive behaviors were monitored. UPR pathways and leptin receptor signaling were assessed in hypothalami. To further examine the mechanistic role of ER stress, changes in leptin receptor (ObR) signaling were also examined in wild-type mice treated with the ER chaperone tauroursodeoxycholic acid (TUDCA), as well as in CHOP-/+ transgenic mice. Fragmented sleep in male mice induced increased food intake starting day 3 and thereafter, which was preceded by increases in ER stress and activation of all three UPR pathways in the hypothalamus. Although ObR expression was unchanged, signal transducer and activator of transcription 3 (STAT3) phosphorylation was decreased, suggesting reduced ObR signaling. Unchanged suppressor of cytokine signaling-3 (SOCS3) expression and increases in protein-tyrosine phosphatase 1B (PTP1B) expression and activity emerged with SF, along with reduced p-STAT3 responses to exogenous leptin. SF-induced effects were reversed following TUDCA treatment and were absent in CHOP -/+ mice. SF induces hyperphagic behaviors and reduced leptin signaling in hypothalamus that are mediated by activation of ER stress, and ultimately lead to increased PTP1B activity. ER stress pathways are therefore potentially implicated in SF-induced weight gain and metabolic dysfunction, and may represent a viable therapeutic target. © 2014 Associated Professional Sleep Societies, LLC.

  2. Transplantation of Gene-Edited Hepatocyte-like Cells Modestly Improves Survival of Arginase-1-Deficient Mice

    Directory of Open Access Journals (Sweden)

    Yuan Yan Sin

    2018-03-01

    Full Text Available Progress in gene editing research has been accelerated by utilizing engineered nucleases in combination with induced pluripotent stem cell (iPSC technology. Here, we report transcription activator-like effector nuclease (TALEN-mediated reincorporation of Arg1 exons 7 and 8 in iPSCs derived from arginase-1-deficient mice possessing Arg1Δ alleles lacking these terminal exons. The edited cells could be induced to differentiate into hepatocyte-like cells (iHLCs in vitro and were subsequently used for transplantation into our previously described (Sin et al., PLoS ONE 2013 tamoxifen-inducible Arg1-Cre arginase-1-deficient mouse model. While successful gene-targeted repair was achieved in iPSCs containing Arg1Δ alleles, only minimal restoration of urea cycle function could be observed in the iHLC-transplanted mice compared to control mice, and survival in this lethal model was extended by up to a week in some mice. The partially rescued phenotype may be due to inadequate regenerative capacity of arginase-1-expressing cells in the correct metabolic zones. Technical hurdles exist and will need to be overcome for gene-edited iPSC to iHLC rescue of arginase-1 deficiency, a rare urea cycle disorder.

  3. TrpC5 Mediates Acute Leptin and Serotonin Effects via Pomc Neurons

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    Yong Gao

    2017-01-01

    Full Text Available The molecular mechanisms underlying acute leptin and serotonin 2C receptor-induced hypophagia remain unclear. Here, we show that neuronal and pro-opiomelanocortin (Pomc-specific loss of transient receptor potential cation 5 (TrpC5 subunits is sufficient to decrease energy expenditure and increase food intake resulting in elevated body weight. Deficiency of Trpc5 subunits in Pomc neurons is also sufficient to block the anorexigenic effects of leptin and serotonin 2C receptor (Ht2Cr agonists. The loss of acute anorexigenic effects of these receptors is concomitant with a blunted electrophysiological response to both leptin and Ht2Cr agonists in arcuate Pomc neurons. We also demonstrate that the Ht2Cr agonist lorcaserin-induced improvements in glucose and insulin tolerance are blocked by TrpC5 deficiency in Pomc neurons. Together, our results link TrpC5 subunits in the brain with leptin- and serotonin 2C receptor-dependent changes in neuronal activity, as well as energy balance, feeding behavior, and glucose metabolism.

  4. Characterization of the gut microbiota in leptin deficient obese mice

    DEFF Research Database (Denmark)

    Ellekilde, Merete; Krych, Lukasz; Hansen, Camilla Hartmann Friis

    2014-01-01

    Gut microbiota have been implicated as a relevant factor in the development of type 2 diabetes mellitus (T2DM), and its diversity might be a cause of variation in animal models of T2DM. In this study, we aimed to characterise the gut microbiota of a T2DM mouse model with a long term vision of being...... able to target the gut microbiota to reduce the number of animals used in experiments. Male B6.V-Lep(ob)/J mice were characterized according to a number of characteristics related to T2DM, inflammation and gut microbiota. All findings were thereafter correlated to one another in a linear regression...... model. The total gut microbiota profile correlated to glycated haemoglobin, and high proportions of Prevotellaceae and Lachnospiraceae correlated to impaired or improved glucose intolerance, respectively. In addition, Akkermansia muciniphila disappeared with age as glucose intolerance worsened. A high...

  5. Elevated hypothalamic TCPTP in obesity contributes to cellular leptin resistance

    Science.gov (United States)

    Loh, Kim; Fukushima, Atsushi; Zhang, Xinmei; Galic, Sandra; Briggs, Dana; Enriori, Pablo J.; Simonds, Stephanie; Wiede, Florian; Reichenbach, Alexander; Hauser, Christine; Sims, Natalie A.; Bence, Kendra K.; Zhang, Sheng; Zhang, Zhong-Yin; Kahn, Barbara B.; Neel, Benjamin G.; Andrews, Zane B.; Cowley, Michael A.; Tiganis, Tony

    2011-01-01

    SUMMARY In obesity, anorectic responses to leptin are diminished, giving rise to the concept of ‘leptin resistance’. Increased expression of protein tyrosine phosphatase 1B (PTP1B) has been associated with the attenuation of leptin signaling and development of cellular leptin resistance. Here we report that hypothalamic levels of the tyrosine phosphatase TCPTP are also elevated in obesity to attenuate the leptin response. We show that mice that lack TCPTP in neuronal cells have enhanced leptin sensitivity and are resistant to high fat diet-induced weight gain and the development of leptin resistance. Also, intracerebroventricular administration of a TCPTP inhibitor enhances leptin signaling and responses in mice. Moreover, the combined deletion of TCPTP and PTP1B in neuronal cells has additive effects in the prevention of diet-induced obesity. Our results identify TCPTP as a critical negative regulator of hypothalamic leptin signaling and causally link elevated TCPTP to the development of cellular leptin resistance in obesity. PMID:22000926

  6. Improvement of diabetes, obesity and hypertension in type 2 diabetic KKAy mice by bis(allixinato)oxovanadium(IV) complex

    International Nuclear Information System (INIS)

    Adachi, Yusuke; Yoshikawa, Yutaka; Yoshida, Jiro; Kodera, Yukihiro; Katoh, Akira; Takada, Jitsuya; Sakurai, Hiromu

    2006-01-01

    Previously, we found that bis(allixinato)oxovanadium(IV) (VO(alx) 2 ) exhibits a potent hypoglycemic activity in type 1-like diabetic mice. Since the enhancement of insulin sensitivity is involved in one of the mechanisms by which vanadium exerts its anti-diabetic effects, VO(alx) 2 was further tested in type 2 diabetes with low insulin sensitivity. The effect of oral administration of VO(alx) 2 was examined in obesity-linked type 2 diabetic KKA y mice. Treatment of VO(alx) 2 for 4 weeks normalized hyperglycemia, glucose intolerance, hyperinsulinemia, hypercholesterolemia and hypertension in KKA y mice; however, it had no effect on hypoadiponectinemia. VO(alx) 2 also improved hyperleptinemia, following attenuation of obesity in KKA y mice. This is the first example in which a vanadium compound improved leptin resistance in type 2 diabetes by oral administration. On the basis of these results, VO(alx) 2 is proposed to enhance not only insulin sensitivity but also leptin sensitivity, which in turn improves diabetes, obesity and hypertension in an obesity-linked type 2 diabetic animal

  7. IGF-1 deficiency impairs cerebral myogenic autoregulation in hypertensive mice.

    Science.gov (United States)

    Toth, Peter; Tucsek, Zsuzsanna; Tarantini, Stefano; Sosnowska, Danuta; Gautam, Tripti; Mitschelen, Matthew; Koller, Akos; Sonntag, William E; Csiszar, Anna; Ungvari, Zoltan

    2014-12-01

    Aging impairs autoregulatory protection in the brain, exacerbating hypertension-induced cerebromicrovascular injury, neuroinflammation, and development of vascular cognitive impairment. Despite the importance of the age-related decline in circulating insulin-like growth factor-1 (IGF-1) levels in cerebrovascular aging, the effects of IGF-1 deficiency on functional adaptation of cerebral arteries to high blood pressure remain elusive. To determine whether IGF-1 deficiency impairs autoregulatory protection, hypertension was induced in control and IGF-1-deficient mice (Igf1(f/f)+TBG-iCre-AAV8) by chronic infusion of angiotensin-II. In hypertensive control mice, cerebral blood flow (CBF) autoregulation was extended to higher pressure values and the pressure-induced tone of middle cerebral arteries (MCAs) was increased. In hypertensive IGF-1-deficient mice, autoregulation was markedly disrupted, and MCAs did not show adaptive increases in myogenic tone. In control mice, the mechanism of adaptation to hypertension involved upregulation of TRPC channels in MCAs and this mechanism was impaired in hypertensive IGF-1-deficient mice. Likely downstream consequences of cerebrovascular autoregulatory dysfunction in hypertensive IGF-1-deficient mice included exacerbated disruption of the blood-brain barrier and neuroinflammation (microglia activation and upregulation of proinflammatory cytokines and chemokines), which were associated with impaired hippocampal cognitive function. Collectively, IGF-1 deficiency impairs autoregulatory protection in the brain of hypertensive mice, potentially exacerbating cerebromicrovascular injury and neuroinflammation mimicking the aging phenotype.

  8. Leptin recruits Creb-regulated transcriptional coactivator 1 to improve hyperglycemia in insulin-deficient diabetes

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    Geun Hyang Kim

    2015-03-01

    Conclusions: Our study reveals that Crtc1 functions as a conduit for leptin's glucoregulatory actions in insulin-dependent diabetes. This study also highlights a new role for Crtc1 in modulating peripheral glucose metabolism.

  9. Neuronal Rap1 Regulates Energy Balance, Glucose Homeostasis, and Leptin Actions.

    Science.gov (United States)

    Kaneko, Kentaro; Xu, Pingwen; Cordonier, Elizabeth L; Chen, Siyu S; Ng, Amy; Xu, Yong; Morozov, Alexei; Fukuda, Makoto

    2016-09-13

    The CNS contributes to obesity and metabolic disease; however, the underlying neurobiological pathways remain to be fully established. Here, we show that the small GTPase Rap1 is expressed in multiple hypothalamic nuclei that control whole-body metabolism and is activated in high-fat diet (HFD)-induced obesity. Genetic ablation of CNS Rap1 protects mice from dietary obesity, glucose imbalance, and insulin resistance in the periphery and from HFD-induced neuropathological changes in the hypothalamus, including diminished cellular leptin sensitivity and increased endoplasmic reticulum (ER) stress and inflammation. Furthermore, pharmacological inhibition of CNS Rap1 signaling normalizes hypothalamic ER stress and inflammation, improves cellular leptin sensitivity, and reduces body weight in mice with dietary obesity. We also demonstrate that Rap1 mediates leptin resistance via interplay with ER stress. Thus, neuronal Rap1 critically regulates leptin sensitivity and mediates HFD-induced obesity and hypothalamic pathology and may represent a potential therapeutic target for obesity treatment. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  10. Leptin and zinc relation : In regulation of food intake and immunity

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    Abdulkerim Kasim Baltaci

    2012-01-01

    Full Text Available Leptin is synthesized and released by the adipose tissue. Leptin, which carries the information about energy reserves of the body to the brain, controls food intake by acting on neuropeptide Y (NPY, which exercises a food-intake-increasing effect through relevant receptors in the hypothalamus. Zinc deficiency is claimed to result in anorexia, weight loss, poor food efficiency, and growth impairment. The fact that obese individuals have low zinc and high leptin levels suggests that there is a relation between zinc and nutrition, and consequently also between zinc and leptin. Leptin deficiency increases the predisposition to infections and this increase is associated with the impairments in the production of cytokines. Zinc has a key role in the sustenance of immune resistance against infections. Dietary zinc deficiency negatively affects CD +4 cells, Th functions, and consequently, cell-mediated immunity by causing a decrease in the production of IL-2, IF-γ, and TNF-α, which are Th1 products. The relation between zinc and the concerned cytokines in particular, and the fact that leptin has a part in the immune responses mediated by these cytokines demonstrate that an interaction among cellular immunity, leptin and zinc is inevitable. An overall evaluation of the information presented above suggests that there are complex relations among food intake, leptin and zinc on one hand and among cellular immunity, leptin and zinc on the other. The aim of the present review was to draw attention to the possible relation between zinc and leptin in dietary regulation and cellular immunity.

  11. MCPIP1 deficiency in mice results in severe anemia related to autoimmune mechanisms.

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    Zhou Zhou

    Full Text Available Autoimmune gastritis is an organ-specific autoimmune disease of the stomach associated with pernicious anemia. The previous work from us and other groups identified MCPIP1 as an essential factor controlling inflammation and immune homeostasis. MCPIP1(-/- developed severe anemia. However, the mechanisms underlying this phenotype remain unclear. In the present study, we found that MCPIP1 deficiency in mice resulted in severe anemia related to autoimmune mechanisms. Although MCPIP1 deficiency did not affect erythropoiesis per se, the erythropoiesis in MCPIP1(-/- bone marrow erythroblasts was significantly attenuated due to iron and vitamin B12 (VB12 deficiency, which was mainly resulted from autoimmunity-associated gastritis and parietal cell loss. Consistently, exogenous supplement of iron and VB12 greatly improved the anemia phenotype of MCPIP1(-/- mice. Finally, we have evidence suggesting that autoimmune hemolysis may also contribute to anemia phenotype of MCPIP1(-/- mice. Taken together, our study suggests that MCPIP1 deficiency in mice leads to the development of autoimmune gastritis and pernicious anemia. Thus, MCPIP1(-/- mice may be a good mouse model for investigating the pathogenesis of pernicious anemia and testing the efficacy of some potential drugs for treatment of this disease.

  12. Circadian behaviour in neuroglobin deficient mice

    DEFF Research Database (Denmark)

    Hundahl, Christian A; Fahrenkrug, Jan; Hay-Schmidt, Anders

    2012-01-01

    on circadian behavior. Ngb-deficient and wild-type (wt) mice were placed in running wheels and their activity rhythms, endogenous period and response to light stimuli were investigated. The effect of Ngb deficiency on the expression of Period1 (Per1) and the immediate early gene Fos was determined after light...

  13. Normal macrophage function in copper deficient mice

    International Nuclear Information System (INIS)

    Lukasewycz, O.A.; Kolquist, K.L.; Prohaska, J.R.

    1986-01-01

    Copper deficiency (-Cu) was produced in C57 BL and C58 mice by feeding a low copper diet (modified AIN-76A) from birth. Mice given supplemental copper in the drinking water (+Cu) served as controls. Copper status was monitored by assay of ceruloplasmin (CP) activity. Macrophages (M0) were obtained from matched +Cu and -Cu male 7 week-old mice by peritoneal lavage 3 days after thioglycollate stimulation. M0 were assayed in terms of lipopolysaccharide-induced hexose monophosphate shunt activity by monitoring 14 CO 2 production from [1- 14 C]-glucose and by the determination of phagocytic index using fluorescein labelled latex bead ingestion. M0 from -Cu mice were equivalent to those of +Cu mice in both these parameters. However, superoxide dismutase and cytochrome oxidase activities were both significantly lower in -Cu M0, confirming a functional copper deficiency. Previous results from this laboratory have shown that -Cu mice have a decreased antibody response to sheep erythrocyte antigens and a diminished reactivity to B and T cell mitogens. These immunological insufficiencies appear to be proportional to the severity of copper depletion as determined by CP levels. Furthermore, -Cu lymphocytes exhibit depressed mixed lymphocyte reactivity consistent with alterations at the membrane surface. The present results suggest that M0/monocytes are less severely affected than lymphocytes in copper deficiency states

  14. Cluster Differentiating 36 (CD36) Deficiency Attenuates Obesity-Associated Oxidative Stress in the Heart.

    Science.gov (United States)

    Gharib, Mohamed; Tao, Huan; Fungwe, Thomas V; Hajri, Tahar

    2016-01-01

    Obesity is often associated with a state of oxidative stress and increased lipid deposition in the heart. More importantly, obesity increases lipid influx into the heart and induces excessive production of reactive oxygen species (ROS) leading to cell toxicity and metabolic dysfunction. Cluster differentiating 36 (CD36) protein is highly expressed in the heart and regulates lipid utilization but its role in obesity-associated oxidative stress is still not clear. The aim of this study was to determine the impact of CD36 deficiency on cardiac steatosis, oxidative stress and lipotoxicity associated with obesity. Studies were conducted in control (Lean), obese leptin-deficient (Lepob/ob) and leptin-CD36 double null (Lepob/obCD36-/-) mice. Compared to lean mice, cardiac steatosis, and fatty acid (FA) uptake and oxidation were increased in Lepob/ob mice, while glucose uptake and oxidation was reduced. Moreover, insulin resistance, oxidative stress markers and NADPH oxidase-dependent ROS production were markedly enhanced. This was associated with the induction of NADPH oxidase expression, and increased membrane-associated p47phox, p67phox and protein kinase C. Silencing CD36 in Lepob/ob mice prevented cardiac steatosis, increased insulin sensitivity and glucose utilization, but reduced FA uptake and oxidation. Moreover, CD36 deficiency reduced NADPH oxidase activity and decreased NADPH oxidase-dependent ROS production. In isolated cardiomyocytes, CD36 deficiency reduced palmitate-induced ROS production and normalized NADPH oxidase activity. CD36 deficiency prevented obesity-associated cardiac steatosis and insulin resistance, and reduced NADPH oxidase-dependent ROS production. The study demonstrates that CD36 regulates NADPH oxidase activity and mediates FA-induced oxidative stress.

  15. Essential fatty acid deficiency in mice impairs lactose digestion

    NARCIS (Netherlands)

    Lukovac, S.; Los, E. L.; Stellaard, F.; Rings, E. H. H. M.; Verkade, H. J.

    Essential fatty acid (EFA) deficiency in mice induces fat malabsorption. We previously reported indications that the underlying mechanism is located at the level of the intestinal mucosa. We have investigated the effects of EFA deficiency on small intestinal morphology and function. Mice were fed an

  16. PTP1B and SHP2 in POMC neurons reciprocally regulate energy balance in mice

    Science.gov (United States)

    Banno, Ryoichi; Zimmer, Derek; De Jonghe, Bart C.; Atienza, Marybless; Rak, Kimberly; Yang, Wentian; Bence, Kendra K.

    2010-01-01

    Protein tyrosine phosphatase 1B (PTP1B) and SH2 domain–containing protein tyrosine phosphatase–2 (SHP2) have been shown in mice to regulate metabolism via the central nervous system, but the specific neurons mediating these effects are unknown. Here, we have shown that proopiomelanocortin (POMC) neuron–specific deficiency in PTP1B or SHP2 in mice results in reciprocal effects on weight gain, adiposity, and energy balance induced by high-fat diet. Mice with POMC neuron–specific deletion of the gene encoding PTP1B (referred to herein as POMC-Ptp1b–/– mice) had reduced adiposity, improved leptin sensitivity, and increased energy expenditure compared with wild-type mice, whereas mice with POMC neuron–specific deletion of the gene encoding SHP2 (referred to herein as POMC-Shp2–/– mice) had elevated adiposity, decreased leptin sensitivity, and reduced energy expenditure. POMC-Ptp1b–/– mice showed substantially improved glucose homeostasis on a high-fat diet, and hyperinsulinemic-euglycemic clamp studies revealed that insulin sensitivity in these mice was improved on a standard chow diet in the absence of any weight difference. In contrast, POMC-Shp2–/– mice displayed impaired glucose tolerance only secondary to their increased weight gain. Interestingly, hypothalamic Pomc mRNA and α–melanocyte-stimulating hormone (αMSH) peptide levels were markedly reduced in POMC-Shp2–/– mice. These studies implicate PTP1B and SHP2 as important components of POMC neuron regulation of energy balance and point to what we believe to be a novel role for SHP2 in the normal function of the melanocortin system. PMID:20160350

  17. An oral Na(V)1.8 blocker improves motor function in mice completely deficient of myelin protein P-0

    DEFF Research Database (Denmark)

    Rosberg, Mette R.; Alvarez Herrero, Susana; Krarup, Christian

    2016-01-01

    Mice deficient of myelin protein P0 are established models of demyelinating Charcot-Marie-Tooth (CMT) disease. Dysmyelination in these mice is associated with an ectopic expression of the sensory neuron specific sodium channel isoform NaV1.8 on motor axons. We reported that in P0+/−, a model of CMT......1B, the membrane dysfunction could be acutely improved by a novel oral NaV1.8 blocker referred to as Compound 31 (C31, Bioorg. Med. Chem. Lett. 2010, 20, 6812; AbbVie Inc.). The aim of this study was to investigate the extent to which C31 treatment could also improve the motor axon function in P0......-of-concept that treatment with oral subtype-selective NaV1.8 blockers could be used to improve the motor function in severe forms of demyelinating CMT....

  18. Oral delivery of [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3, synthetic peptide leptin mimetics: Immunofluorescent localization in the mouse hypothalamus.

    Science.gov (United States)

    Anderson, Brian M; Jacobson, Lauren; Novakovic, Zachary M; Grasso, Patricia

    2017-06-01

    This study describes the localization of [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3, synthetic peptide leptin mimetics, in the hypothalamus of Swiss Webster and C57BL/6J wild-type mice, leptin-deficient ob/ob mice, and leptin-resistant diet-induced obese (DIO) mice. The mice were given [D-Leu-4]-OB3 or MA-[D-Leu-4]-OB3 in 0.3% dodecyl maltoside by oral gavage. Once peak serum concentrations were reached, the mice received a lethal dose of pentobarbital and were subjected to intracardiac perfusion fixation. The brains were excised, post-fixed in paraformaldehyde, and cryo-protected in sucrose. Free-floating frozen coronal sections were cut at 25-µm and processed for imaging by immunofluorescence microscopy. In all four strains of mice, dense staining was concentrated in the area of the median eminence, at the base and/or along the inner wall of the third ventricle, and in the brain parenchyma at the level of the arcuate nucleus. These results indicate that [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3 cross the blood-brain barrier and concentrate in an area of the hypothalamus known to regulate energy balance and glucose homeostasis. Most noteworthy is the localization of [D-Leu-4]-OB3 immunoreactivity within the hypothalamus of DIO mice via a conduit that is closed to leptin in this rodent model, and in most cases of human obesity. Together with our previous studies describing the effects of [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3 on energy balance, glucose regulation, and signal transduction pathway activation, these findings are consistent with a central mechanism of action for these synthetic peptide leptin mimetics, and suggest their potential usefulness in the management of leptin-resistant obesity and type 2 diabetes in humans. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Transport across the blood-brain barrier of pluronic leptin.

    Science.gov (United States)

    Price, Tulin O; Farr, Susan A; Yi, Xiang; Vinogradov, Serguei; Batrakova, Elena; Banks, William A; Kabanov, Alexander V

    2010-04-01

    Leptin is a peptide hormone produced primarily by adipose tissue that acts as a major regulator of food intake and energy homeostasis. Impaired transport of leptin across the blood-brain barrier (BBB) contributes to leptin resistance, which is a cause of obesity. Leptin as a candidate for the treatment of this obesity is limited because of the short half-life in circulation and the decreased BBB transport that arises in obesity. Chemical modification of polypeptides with amphiphilic poly(ethylene oxide)-poly(propylene oxide) block copolymers (Pluronic) is a promising technology to improve efficiency of delivery of polypeptides to the brain. In the present study, we determined the effects of Pluronic P85 (P85) with intermediate hydrophilic-lipophilic balance conjugated with leptin via a degradable SS bond [leptin(ss)-P85] on food intake, clearance, stability, and BBB uptake. The leptin(ss)-P85 exhibited biological activity when injected intracerebroventricularly after overnight food deprivation and 125I-leptin(ss)-P85 was stable in blood, with a half-time clearance of 32.3 min (versus 5.46 min for leptin). 125I-Leptin(ss)-P85 crossed the BBB [blood-to-brain unidirectional influx rate (K(i)) = 0.272 +/- 0.037 microl/g x min] by a nonsaturable mechanism unrelated to the leptin transporter. Capillary depletion showed that most of the 125I-leptin(ss)-P85 taken up by the brain reached the brain parenchyma. Food intake was reduced when 3 mg of leptin(ss)-P85 was administered via tail vein in normal body weight mice [0-30 min, p penetration by a mechanism-independent BBB leptin transporter.

  20. Adaptive gene regulation in the Striatum of RGS9-deficient mice.

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    Kathy Busse

    Full Text Available BACKGROUND: RGS9-deficient mice show drug-induced dyskinesia but normal locomotor activity under unchallenged conditions. RESULTS: Genes related to Ca2+ signaling and their functions were regulated in RGS9-deficient mice. CONCLUSION: Changes in Ca2+ signaling that compensate for RGS9 loss-of-function can explain the normal locomotor activity in RGS9-deficient mice under unchallenged conditions. SIGNIFICANCE: Identified signaling components may represent novel targets in antidyskinetic therapy. The long splice variant of the regulator of G-protein signaling 9 (RGS9-2 is enriched in striatal medium spiny neurons and dampens dopamine D2 receptor signaling. Lack of RGS9-2 can promote while its overexpression prevents drug-induced dyskinesia. Other animal models of drug-induced dyskinesia rather pointed towards overactivity of dopamine receptor-mediated signaling. To evaluate changes in signaling pathways mRNA expression levels were determined and compared in wild-type and RGS9-deficient mice. Unexpectedly, expression levels of dopamine receptors were unchanged in RGS9-deficient mice, while several genes related to Ca2+ signaling and long-term depression were differentially expressed when compared to wild type animals. Detailed investigations at the protein level revealed hyperphosphorylation of DARPP32 at Thr34 and of ERK1/2 in striata of RGS9-deficient mice. Whole cell patch clamp recordings showed that spontaneous synaptic events are increased (frequency and size in RGS9-deficient mice while long-term depression is reduced in acute brain slices. These changes are compatible with a Ca2+-induced potentiation of dopamine receptor signaling which may contribute to the drug-induced dyskinesia in RGS9-deficient mice.

  1. Circadian behaviour in neuroglobin deficient mice.

    Directory of Open Access Journals (Sweden)

    Christian A Hundahl

    Full Text Available Neuroglobin (Ngb, a neuron-specific oxygen-binding globin with an unknown function, has been proposed to play a key role in neuronal survival. We have previously shown Ngb to be highly expressed in the rat suprachiasmatic nucleus (SCN. The present study addresses the effect of Ngb deficiency on circadian behavior. Ngb-deficient and wild-type (wt mice were placed in running wheels and their activity rhythms, endogenous period and response to light stimuli were investigated. The effect of Ngb deficiency on the expression of Period1 (Per1 and the immediate early gene Fos was determined after light stimulation at night and the neurochemical phenotype of Ngb expressing neurons in wt mice was characterized. Loss of Ngb function had no effect on overall circadian entrainment, but resulted in a significantly larger phase delay of circadian rhythm upon light stimulation at early night. A light-induced increase in Per1, but not Fos, gene expression was observed in Ngb-deficient mice. Ngb expressing neurons which co-stored Gastrin Releasing Peptide (GRP and were innervated from the eye and the geniculo-hypothalamic tract expressed FOS after light stimulation. No PER1 expression was observed in Ngb-positive neurons. The present study demonstrates for the first time that the genetic elimination of Ngb does not affect core clock function but evokes an increased behavioural response to light concomitant with increased Per1 gene expression in the SCN at early night.

  2. Select cognitive deficits in Vasoactive Intestinal Peptide deficient mice

    Directory of Open Access Journals (Sweden)

    Hagopian Arkady

    2008-07-01

    Full Text Available Abstract Background The neuropeptide vasoactive intestinal peptide (VIP is widely distributed in the adult central nervous system where this peptide functions to regulate synaptic transmission and neural excitability. The expression of VIP and its receptors in brain regions implicated in learning and memory functions, including the hippocampus, cortex, and amygdala, raise the possibility that this peptide may function to modulate learned behaviors. Among other actions, the loss of VIP has a profound effect on circadian timing and may specifically influence the temporal regulation of learning and memory functions. Results In the present study, we utilized transgenic VIP-deficient mice and the contextual fear conditioning paradigm to explore the impact of the loss of this peptide on a learned behavior. We found that VIP-deficient mice exhibited normal shock-evoked freezing behavior and increases in corticosterone. Similarly, these mutant mice exhibited no deficits in the acquisition or recall of the fear-conditioned behavior when tested 24-hours after training. The VIP-deficient mice exhibited a significant reduction in recall when tested 48-hours or longer after training. Surprisingly, we found that the VIP-deficient mice continued to express circadian rhythms in the recall of the training even in those individual mice whose wheel running wheel activity was arrhythmic. One mechanistic explanation is suggested by the finding that daily rhythms in the expression of the clock gene Period2 continue in the hippocampus of VIP-deficient mice. Conclusion Together these data suggest that the neuropeptide VIP regulates the recall of at least one learned behavior but does not impact the circadian regulation of this behavior.

  3. Involvement of Amylin and Leptin in the Development of Projections from the Area Postrema to the Nucleus of the Solitary Tract

    Directory of Open Access Journals (Sweden)

    Kathrin Abegg

    2017-11-01

    Full Text Available The area postrema (AP and the nucleus of the solitary tract (NTS are important hindbrain centers involved in the control of energy homeostasis. The AP mediates the anorectic action and the inhibitory effect on gastric emptying induced by the pancreatic hormone amylin. Amylin’s target cells in the AP project to the NTS, an integrative relay center for enteroceptive signals. Perinatal hormonal and metabolic factors influence brain development. A postnatal surge of the adipocyte-derived hormone leptin represents a developmental signal for the maturation of projections between hypothalamic nuclei controlling energy balance. Amylin appears to promote neurogenesis in the AP in adult rats. Here, we examined whether amylin and leptin are required for the development of projections from the AP to the NTS in postnatal and adult mice by conducting neuronal tracing studies with DiI in amylin- (IAPP−/− and leptin-deficient (ob/ob mice. Compared to wild-type littermates, postnatal (P10 and adult (P60 IAPP−/− mice showed a significantly reduced density of AP-NTS projections. While AP projections were also reduced in postnatal (P14 ob/ob mice, AP-NTS fiber density did not differ between adult ob/ob and wild-type animals. Our findings suggest a crucial function of amylin for the maturation of neuronal brainstem pathways controlling energy balance and gastrointestinal function. The impaired postnatal development of neuronal AP-NTS projections in ob/ob mice appears to be compensated in this experimental model during later brain maturation. It remains to be elucidated whether an amylin- and leptin-dependent modulation in neuronal development translates into altered AP/NTS-mediated functions.

  4. Adipose tissue deficiency of hormone-sensitive lipase causes fatty liver in mice.

    Science.gov (United States)

    Xia, Bo; Cai, Guo He; Yang, Hao; Wang, Shu Pei; Mitchell, Grant A; Wu, Jiang Wei

    2017-12-01

    Fatty liver is a major health problem worldwide. People with hereditary deficiency of hormone-sensitive lipase (HSL) are reported to develop fatty liver. In this study, systemic and tissue-specific HSL-deficient mice were used as models to explore the underlying mechanism of this association. We found that systemic HSL deficient mice developed fatty liver in an age-dependent fashion between 3 and 8 months of age. To further explore the mechanism of fatty liver in HSL deficiency, liver-specific HSL knockout mice were created. Surprisingly, liver HSL deficiency did not influence liver fat content, suggesting that fatty liver in HSL deficiency is not liver autonomous. Given the importance of adipose tissue in systemic triglyceride metabolism, we created adipose-specific HSL knockout mice and found that adipose HSL deficiency, to a similar extent as systemic HSL deficiency, causes age-dependent fatty liver in mice. Mechanistic study revealed that deficiency of HSL in adipose tissue caused inflammatory macrophage infiltrates, progressive lipodystrophy, abnormal adipokine secretion and systemic insulin resistance. These changes in adipose tissue were associated with a constellation of changes in liver: low levels of fatty acid oxidation, of very low density lipoprotein secretion and of triglyceride hydrolase activity, each favoring the development of hepatic steatosis. In conclusion, HSL-deficient mice revealed a complex interorgan interaction between adipose tissue and liver: the role of HSL in the liver is minimal but adipose tissue deficiency of HSL can cause age-dependent hepatic steatosis. Adipose tissue is a potential target for treating the hepatic steatosis of HSL deficiency.

  5. Analysis of glomerulosclerosis and atherosclerosis in lecithin cholesterol acyltransferase-deficient mice.

    Science.gov (United States)

    Lambert, G; Sakai, N; Vaisman, B L; Neufeld, E B; Marteyn, B; Chan, C C; Paigen, B; Lupia, E; Thomas, A; Striker, L J; Blanchette-Mackie, J; Csako, G; Brady, J N; Costello, R; Striker, G E; Remaley, A T; Brewer, H B; Santamarina-Fojo, S

    2001-05-04

    To evaluate the biochemical and molecular mechanisms leading to glomerulosclerosis and the variable development of atherosclerosis in patients with familial lecithin cholesterol acyl transferase (LCAT) deficiency, we generated LCAT knockout (KO) mice and cross-bred them with apolipoprotein (apo) E KO, low density lipoprotein receptor (LDLr) KO, and cholesteryl ester transfer protein transgenic mice. LCAT-KO mice had normochromic normocytic anemia with increased reticulocyte and target cell counts as well as decreased red blood cell osmotic fragility. A subset of LCAT-KO mice accumulated lipoprotein X and developed proteinuria and glomerulosclerosis characterized by mesangial cell proliferation, sclerosis, lipid accumulation, and deposition of electron dense material throughout the glomeruli. LCAT deficiency reduced the plasma high density lipoprotein (HDL) cholesterol (-70 to -94%) and non-HDL cholesterol (-48 to -85%) levels in control, apoE-KO, LDLr-KO, and cholesteryl ester transfer protein-Tg mice. Transcriptome and Western blot analysis demonstrated up-regulation of hepatic LDLr and apoE expression in LCAT-KO mice. Despite decreased HDL, aortic atherosclerosis was significantly reduced (-35% to -99%) in all mouse models with LCAT deficiency. Our studies indicate (i) that the plasma levels of apoB containing lipoproteins rather than HDL may determine the atherogenic risk of patients with hypoalphalipoproteinemia due to LCAT deficiency and (ii) a potential etiological role for lipoproteins X in the development of glomerulosclerosis in LCAT deficiency. The availability of LCAT-KO mice characterized by lipid, hematologic, and renal abnormalities similar to familial LCAT deficiency patients will permit future evaluation of LCAT gene transfer as a possible treatment for glomerulosclerosis in LCAT-deficient states.

  6. Leptin in humans: lessons from translational research1234

    OpenAIRE

    Blüher, Susann; Mantzoros, Christos S

    2009-01-01

    Leptin has emerged over the past decade as a key hormone in not only the regulation of food intake and energy expenditure but also in the regulation of neuroendocrine and immune function as well as the modulation of glucose and fat metabolism as shown by numerous observational and interventional studies in humans with (complete) congenital or relative leptin deficiency. These results have led to proof-of-concept studies that have investigated the effect of leptin administration in subjects wi...

  7. Preferential effects of leptin on CD4 T cells in central and peripheral immune system are critically linked to the expression of leptin receptor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, So Yong; Lim, Ju Hyun [Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746 (Korea, Republic of); Choi, Sung Won [Department of Molecular Biology, School of Arts and Sciences (S.W.C), Cornell University, Ithaca, NY 18450 (United States); Kim, Miyoung; Kim, Seong-Tae [Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746 (Korea, Republic of); Kim, Min-Seon; Cho, You Sook [Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul 138-600 (Korea, Republic of); Chun, Eunyoung, E-mail: chun.eunyoung@gmail.com [Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746 (Korea, Republic of); Lee, Ki-Young, E-mail: thylee@med.skku.ac.kr [Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746 (Korea, Republic of)

    2010-04-09

    Leptin can enhance thymopoiesis and modulate the T-cell immune response. However, it remains controversial whether these effects correlate with the expression of leptin receptor, ObR. We herein addressed this issue by using in vivo animal models and in vitro culture systems. Leptin treatment in both ob/ob mice and normal young mice induced increases of CD4 SP thymocytes in thymus and CD4 T cells in the periphery. Interestingly, expression of the long form ObR was significantly restricted to DN, DP and CD4 SP, but not CD8 SP thymocytes. Moreover, in the reaggregated DP thymocyte cultures with leptin plus TSCs, leptin profoundly induced differentiation of CD4 SP but not CD8 SP thymocytes, suggesting that the effects of leptin on thymocyte differentiation might be closely related to the expression of leptin receptor in developing thymocytes. Surprisingly, ObR expression was markedly higher in peripheral CD4 T cells than that in CD8 T cells. Furthermore, leptin treatment with or without IL-2 and PHA had preferential effects on cell proliferation of CD4 T cells compared to that of CD8 T cells. Collectively, these data provide evidence that the effects of leptin on differentiation and proliferation of CD4 T cells might be closely related to the expression of leptin receptor.

  8. Preferential effects of leptin on CD4 T cells in central and peripheral immune system are critically linked to the expression of leptin receptor

    International Nuclear Information System (INIS)

    Kim, So Yong; Lim, Ju Hyun; Choi, Sung Won; Kim, Miyoung; Kim, Seong-Tae; Kim, Min-Seon; Cho, You Sook; Chun, Eunyoung; Lee, Ki-Young

    2010-01-01

    Leptin can enhance thymopoiesis and modulate the T-cell immune response. However, it remains controversial whether these effects correlate with the expression of leptin receptor, ObR. We herein addressed this issue by using in vivo animal models and in vitro culture systems. Leptin treatment in both ob/ob mice and normal young mice induced increases of CD4 SP thymocytes in thymus and CD4 T cells in the periphery. Interestingly, expression of the long form ObR was significantly restricted to DN, DP and CD4 SP, but not CD8 SP thymocytes. Moreover, in the reaggregated DP thymocyte cultures with leptin plus TSCs, leptin profoundly induced differentiation of CD4 SP but not CD8 SP thymocytes, suggesting that the effects of leptin on thymocyte differentiation might be closely related to the expression of leptin receptor in developing thymocytes. Surprisingly, ObR expression was markedly higher in peripheral CD4 T cells than that in CD8 T cells. Furthermore, leptin treatment with or without IL-2 and PHA had preferential effects on cell proliferation of CD4 T cells compared to that of CD8 T cells. Collectively, these data provide evidence that the effects of leptin on differentiation and proliferation of CD4 T cells might be closely related to the expression of leptin receptor.

  9. Twentieth Anniversary of Leptin discovery and the Approval of Myalept by FDA

    Directory of Open Access Journals (Sweden)

    Ata Mahmoodpoor

    2015-04-01

    Full Text Available Leptin is a 16 kDa hormone that is mainly expressed in adipose tissues (1. The major target of leptin is hypothalamus and it suppresses food intake and energy consumption, consequently diminishing adipose deposits and body weight (2, 3. The OB gene was isolated by Friedman in 1994 (4.  Based on the suggestion of Roger Guillemin, Friedman named this new hormone "leptin" from the Greek lepto meaning thin (5, 6. Since leptin discovery, numerous studies have been conducted on its physiological effects and its function in pathological conditions. Most of studies on leptin concentrated on its metabolic actions (7, receptors (8 and further broad functions such as immunity modulation (9 and memory processing (10. Considering such a vast range of functions, it is clear that patients with lack of leptin physiologically need pharmacological interventions. At this moment, we are in the twentieth year of leptin discovery. Finally, FDA approved a drug named Myalept (metreleptin for injection on February 2014 to treat rare metabolic disease caused by leptin deficiency. Congenital generalized lipodystrophy is a disorder with partial lack of fat tissues (11. The trial for the safety and effectiveness of Myalept demonstrated decrease in HbA1c, fasting blood glucose, and triglycerides (11. Nevertheless, there are some limitations to the usage of Myalept in HIV-related lipodystrophy and some metabolic disorders (11. Moreover, it may increase the risk of lymphoma by producing anti-metreleptin antibodies neutralizing endogenous leptin. Considering these concerns, Myalept is available only through a limited profile under a Risk Evaluation and Mitigation Strategy (REMS. Myalept is contraindicated in patients with general obesity not related to congenital leptin deficiency (12. Even though, Myalept has very limited indications for use in general population, it is considered a milestone towards the discovery of novel treatments for Leptin deficiencies and disorders

  10. Role of GABA Release From Leptin Receptor-Expressing Neurons in Body Weight Regulation

    Science.gov (United States)

    Xu, Yuanzhong; O'Brien, William G.; Lee, Cheng-Chi; Myers, Martin G.

    2012-01-01

    It is well established that leptin regulates energy balance largely through isoform B leptin receptor-expressing neurons (LepR neurons) in the brain and that leptin activates one subset of LepR neurons (leptin-excited neurons) while inhibiting the other (leptin-inhibited neurons). However, the neurotransmitters released from LepR neurons that mediate leptin action in the brain are not well understood. Previous results demonstrate that leptin mainly acts on γ-aminobutyric acid (GABA)ergic neurons to reduce body weight, and that leptin activates proopiomelanocortin neuron activity by reducing GABA release onto these neurons, suggesting a body weight-promoting role for GABA released from leptin-inhibited neurons. To directly examine the role of GABA release from LepR neurons in body weight regulation, mice with disruption of GABA release specifically from LepR neurons were generated by deletion of vesicular GABA transporter in LepR neurons. Interestingly, these mice developed mild obesity on chow diet and were sensitive to diet-induced obesity, which were associated with higher food intake and lower energy expenditure. Moreover, these mice showed blunted responses in both food intake and body weight to acute leptin administration. These results demonstrate that GABA plays an important role in mediating leptin action. In combination with the previous studies that leptin reduces GABA release onto proopiomelanocortin neurons through leptin-inhibited neurons and that disruption of GABA release from agouti gene-related protein neurons, one subset of LepR-inhibited neurons, leads to a lean phenotype, our results suggest that, under our experimental conditions, GABA release from leptin-excited neuron dominates over leptin-inhibited ones. PMID:22334723

  11. Proinflammatory adipokine leptin mediates disinfection byproduct bromodichloromethane-induced early steatohepatitic injury in obesity

    International Nuclear Information System (INIS)

    Das, Suvarthi; Kumar, Ashutosh; Seth, Ratanesh Kumar; Tokar, Erik J.; Kadiiska, Maria B.; Waalkes, Michael P.; Mason, Ronald P.; Chatterjee, Saurabh

    2013-01-01

    Today's developed world faces a major public health challenge in the rise in the obese population and the increased incidence in fatty liver disease. There is a strong association among diet induced obesity, fatty liver disease and development of nonalcoholic steatohepatitis but the environmental link to disease progression remains unclear. Here we demonstrate that in obesity, early steatohepatitic lesions induced by the water disinfection byproduct bromodichloromethane are mediated by increased oxidative stress and leptin which act in synchrony to potentiate disease progression. Low acute exposure to bromodichloromethane (BDCM), in diet-induced obesity produced oxidative stress as shown by increased lipid peroxidation, protein free radical and nitrotyrosine formation and elevated leptin levels. Exposed obese mice showed histopathological signs of early steatohepatitic injury and necrosis. Spontaneous knockout mice for leptin or systemic leptin receptor knockout mice had significantly decreased oxidative stress and TNF-α levels. Co-incubation of leptin and BDCM caused Kupffer cell activation as shown by increased MCP-1 release and NADPH oxidase membrane assembly, a phenomenon that was decreased in Kupffer cells isolated from leptin receptor knockout mice. In obese mice that were BDCM-exposed, livers showed a significant increase in Kupffer cell activation marker CD68 and, increased necrosis as assessed by levels of isocitrate dehydrogenase, events that were decreased in the absence of leptin or its receptor. In conclusion, our results show that exposure to the disinfection byproduct BDCM in diet-induced obesity augments steatohepatitic injury by potentiating the effects of leptin on oxidative stress, Kupffer cell activation and cell death in the liver. - Highlights: ► BDCM acute exposure sensitizes liver to increased free radical stress in obesity. ► BDCM-induced higher leptin contributes to early steatohepatitic lesions. ► Increased leptin mediates protein

  12. Proinflammatory adipokine leptin mediates disinfection byproduct bromodichloromethane-induced early steatohepatitic injury in obesity

    Energy Technology Data Exchange (ETDEWEB)

    Das, Suvarthi [Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208 (United States); Kumar, Ashutosh [Free Radical Metabolism Group, Laboratory of Toxicology and Pharmacology, Research Triangle Park, NC 27709 (United States); Seth, Ratanesh Kumar [Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208 (United States); Tokar, Erik J. [Inorganic Toxicology Group, National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 (United States); Kadiiska, Maria B. [Free Radical Metabolism Group, Laboratory of Toxicology and Pharmacology, Research Triangle Park, NC 27709 (United States); Waalkes, Michael P. [Inorganic Toxicology Group, National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 (United States); Mason, Ronald P. [Free Radical Metabolism Group, Laboratory of Toxicology and Pharmacology, Research Triangle Park, NC 27709 (United States); Chatterjee, Saurabh, E-mail: schatt@mailbox.sc.edu [Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208 (United States)

    2013-06-15

    Today's developed world faces a major public health challenge in the rise in the obese population and the increased incidence in fatty liver disease. There is a strong association among diet induced obesity, fatty liver disease and development of nonalcoholic steatohepatitis but the environmental link to disease progression remains unclear. Here we demonstrate that in obesity, early steatohepatitic lesions induced by the water disinfection byproduct bromodichloromethane are mediated by increased oxidative stress and leptin which act in synchrony to potentiate disease progression. Low acute exposure to bromodichloromethane (BDCM), in diet-induced obesity produced oxidative stress as shown by increased lipid peroxidation, protein free radical and nitrotyrosine formation and elevated leptin levels. Exposed obese mice showed histopathological signs of early steatohepatitic injury and necrosis. Spontaneous knockout mice for leptin or systemic leptin receptor knockout mice had significantly decreased oxidative stress and TNF-α levels. Co-incubation of leptin and BDCM caused Kupffer cell activation as shown by increased MCP-1 release and NADPH oxidase membrane assembly, a phenomenon that was decreased in Kupffer cells isolated from leptin receptor knockout mice. In obese mice that were BDCM-exposed, livers showed a significant increase in Kupffer cell activation marker CD68 and, increased necrosis as assessed by levels of isocitrate dehydrogenase, events that were decreased in the absence of leptin or its receptor. In conclusion, our results show that exposure to the disinfection byproduct BDCM in diet-induced obesity augments steatohepatitic injury by potentiating the effects of leptin on oxidative stress, Kupffer cell activation and cell death in the liver. - Highlights: ► BDCM acute exposure sensitizes liver to increased free radical stress in obesity. ► BDCM-induced higher leptin contributes to early steatohepatitic lesions. ► Increased leptin mediates

  13. Exhaustion of CTL memory and recrudescence of viremia in lymphocytic choriomeningitis virus-infected MHC class II-deficient mice and B cell-deficient mice

    DEFF Research Database (Denmark)

    Thomsen, Allan Randrup; Johansen, J; Marker, O

    1996-01-01

    To study the contribution of CD4+ T cells and B cells to antiviral immunity and long term virus control, MHC class II-deficient and B cell-deficient mice were infected with lymphocytic choriomeningitis virus. In class II-deficient mice, which lack CD4+ T cells, the primary CTL response is virtually...... this phenomenon could reflect participation of B cells and/or Abs in long term virus control, similar experiments were performed with mice that do not have mature B cells because of a disrupted membrane exon of the mu chain gene. In these mice, the cell-mediated immune response was slightly delayed, but transient...... and that in their absence, the virus-specific CTL potential becomes exhausted. Together our results indicate that while CD8+ cells play a dominant role in acute virus control, all three major components of the immune system are required for long term virus control....

  14. Dual specificity phosphatase 6 deficiency is associated with impaired systemic glucose tolerance and reversible weight retardation in mice.

    Directory of Open Access Journals (Sweden)

    Katrin Pfuhlmann

    Full Text Available Here, we aimed to investigate the potential role of DUSP6, a dual specificity phosphatase, that specifically inactivates extracellular signal-regulated kinase (ERK, for the regulation of body weight and glucose homeostasis. We further assessed whether metabolic challenges affect Dusp6 expression in selected brain areas or white adipose tissue. Hypothalamic Dusp6 mRNA levels remained unchanged in chow-fed lean vs. high fat diet (HFD fed obese C57Bl/6J mice, and in C57Bl/6J mice undergoing prolonged fasting or refeeding with fat free diet (FFD or HFD. Similarly, Dusp6 expression levels were unchanged in selected brain regions of Lepob mice treated with 1 mg/kg of leptin for 6 days, compared to pair-fed or saline-treated Lepob controls. Dusp6 expression levels remained unaltered in vitro in primary adipocytes undergoing differentiation, but were increased in eWAT of HFD-fed obese C57Bl/6J mice, compared to chow-fed lean controls. Global chow-fed DUSP6 KO mice displayed reduced body weight and lean mass and slightly increased fat mass at a young age, which is indicative for early-age weight retardation. Subsequent exposure to HFD led to a significant increase in lean mass and body weight in DUSP6 deficient mice, compared to WT controls. Nevertheless, after 26 weeks of high-fat diet exposure, we observed comparable body weight, fat and lean mass in DUSP6 WT and KO mice, suggesting overall normal susceptibility to develop obesity. In line with the increased weight gain to compensate for early-age weight retardation, HFD-fed DUSP6 KO displayed increased expression levels of anabolic genes involved in lipid and cholesterol metabolism in the epididymal white adipose tissue (eWAT, compared to WT controls. Glucose tolerance was perturbed in both chow-fed lean or HFD-fed obese DUSP6 KO, compared to their respective WT controls. Overall, our data indicate that DUSP6 deficiency has limited impact on the regulation of energy metabolism, but impairs systemic

  15. Uptakes of trace elements in Zn-deficient mice

    International Nuclear Information System (INIS)

    Ohyama, T.; Yanaga, M.; Yoshida, T.; Maetsu, H.; Suganuma, H.; Omori, T.

    2002-01-01

    A multitracer technique was used to obtain uptake rates of essential trace elements in various organs and tissues in Zn-deficient mice. A multitracer solution, containing more than 20 radioisotopes, was injected intraperitoneally into Zn-deficient state mice and control ones. Uptake rates of the radioisotopes were compared with concentrations of trace elements determined by instrumental neutron activation analysis (INAA) in order to study a specific metabolism of Zn and other essential trace elements, such as Mn, Co, Se, Rb, and Sr. The result suggests that Zn is supplied from bone to other organs and tissues and an increase in Co concentration in all organs and tissues depends on its chemical form, under the Z-deficient state. (author)

  16. Fucosylation Deficiency in Mice Leads to Colitis and Adenocarcinoma

    Science.gov (United States)

    Wang, Yiwei; Huang, Dan; Chen, Kai-Yuan; Cui, Min; Wang, Weihuan; Huang, Xiaoran; Awadellah, Amad; Li, Qing; Friedman, Ann; Xin, William W.; Di Martino, Luca; Cominelli, Fabio; Miron, Alex; Chan, Ricky; Fox, James; Xu, Yan; Shen, Xiling; Kalady, Mathew F.; Markowitz, Sanford; Maillard, Ivan; Lowe, John B.; Xin, Wei; Zhou, Lan

    2016-01-01

    Background & Aims De novo synthesis of GDP-fucose, a substrate for fucosylglycans, requires sequential reactions mediated by GDP-mannose 4,6-dehydratase (GMDS) and GDP-4-keto-6-deoxymannose 3,5-epimerase-4-reductase (FX or TSTA3). GMDS deletions and mutations are found in 6%–13% of colorectal cancers; these mostly affect ascending and transverse colon. We investigated whether lack of fucosylation consequent to loss of GDP-fucose synthesis contributes to colon carcinogenesis. Methods FX deficiency and GMDS deletion produce the same biochemical phenotype of GDP-fucose deficiency. We studied a mouse model of fucosylation deficiency (Fx–/– mice) and mice with the full-length Fx gene (controls). Mice were placed on standard chow or fucose-containing diet (equivalent to a control fucosylglycan phenotype). Colon tissues were collected and analyzed histologically or by ELISAs to measure cytokine levels; T cells were also collected and analyzed. Fecal samples were analyzed by 16s rRNA sequencing. Mucosal barrier function was measured by uptake of fluorescent dextran. We transplanted bone marrow cells from Fx–/– or control mice (Ly5.2) into irradiated 8-week old Fx–/– or control mice (Ly5.1). We performed immunohistochemical analyses for expression of Notch and the hes family bHLH transcription factor (HES1) in colon tissues from mice and a panel of 60 human colorectal cancer specimens (27 left-sided, 33 right-sided). Results Fx–/– mice developed colitis and serrated-like lesions. The intestinal pathology of Fx–/– mice was reversed by addition of fucose to the diet, which restored fucosylation via a salvage pathway. In the absence of fucosylation, dysplasia appeared and progressed to adenocarcinoma in up to 40% of mice, affecting mainly the right colon and cecum. Notch was not activated in Fx–/– mice fed standard chow, leading to decreased expression of its target Hes1. Fucosylation deficiency altered the composition of the fecal microbiota, reduced

  17. Increased leptin/leptin receptor pathway affects systemic and airway inflammation in COPD former smokers

    Directory of Open Access Journals (Sweden)

    Bruno A

    2011-05-01

    Full Text Available Andreina Bruno1, Marinella Alessi2, Simona Soresi2, Anna Bonanno1, Loredana Riccobono1, Angela Marina Montalbano1, Giusy Daniela Albano1, Mark Gjomarkaj1, Mirella Profita11Institute of Biomedicine and Molecular Immunology, Italian National Research Council, Palermo, Italy; 2Dipartimento Biomedico di Biomedicina Interna e Specialistica, University Palermo, ItalyBackground: Leptin, a hormone produced mainly by adipose tissue, regulates food intake and energy expenditure. It is involved in inflammatory diseases such as chronic obstructive pulmonary disease (COPD and its deficiency is associated with increased susceptibility to the infection. The leptin receptor is expressed in the lung and in the neutrophils.Methods: We measured the levels of leptin, tumor necrosis factor alpha (TNF-a and soluble form of intercellular adhesion molecule-1 (sICAM-1 in sputum and plasma from 27 smoker and former smoker patients with stable COPD using ELISA methods. Further we analyzed leptin and its receptor expression in sputum cells from 16 COPD patients using immunocytochemistry.Results: In plasma of COPD patients, leptin was inversely correlated with TNF-a and positively correlated with the patient weight, whereas the levels of sICAM-1 were positively correlated with TNF-a. In sputum of COPD patients leptin levels were correlated with forced expiratory volume in 1 second/forced vitality capacity. Additionally, increased levels of sputum leptin and TNF-a were observed in COPD former smokers rather than smokers. Further the expression of leptin receptor in sputum neutrophils was significantly higher in COPD former smokers than in smokers, and the expression of leptin and its receptor was positively correlated in neutrophils of COPD former smokers.Conclusion: Our findings suggest a role of leptin in the local and systemic inflammation of COPD and, taking into account the involvement of neutrophils in this inflammatory disease, describe a novel aspect of the leptin/leptin

  18. SOCS-1 deficiency does not prevent diet-induced insulin resistance

    DEFF Research Database (Denmark)

    Emanuelli, Brice; Macotela, Yazmin; Boucher, Jérémie

    2008-01-01

    Obesity is associated with inflammation and increased expression of suppressor of cytokine signaling (SOCS) proteins, which inhibit cytokine and insulin signaling. Thus, reducing SOCS expression could prevent the development of obesity-induced insulin resistance. Using SOCS-1 knockout mice, we...... investigated the contribution of SOCS-1 in the development of insulin resistance induced by a high-fat diet (HFD). SOCS-1 knockout mice on HFD gained 70% more weight, displayed a 2.3-fold increase in epididymal fat pads mass and increased hepatic lipid content. This was accompanied by increased mRNA expression...... of leptin and the macrophage marker CD68 in white adipose tissue and of SREBP1c and FAS in liver. HFD also induced hyperglycemia in SOCS-1 deficient mice with impairment of glucose and insulin tolerance tests. Thus, despite the role of SOCS proteins in obesity-related insulin resistance, SOCS-1 deficiency...

  19. Enhanced glucose cycling and suppressed de novo synthesis of glucose-6-phosphate result in a net unchanged hepatic glucose output in ob/ob mice

    NARCIS (Netherlands)

    Bandsma, RHJ; Grefhorst, A; van Dijk, TH; van der Sluijs, FH; Hammer, A; Reijngoud, DJ; Kuipers, F

    2004-01-01

    Aims/hypothesis. Leptin-deficient ob/ob mice are hyperinsulinaemic and hyperglycaemic; however, the cause of hyperglycaemia remains largely unknown. Methods. Glucose metabolism in vivo in 9-h fasted ob/ob mice and lean littermates was studied by infusing [U-C-13]-glucose, [2-C-13]-glycerol,

  20. Toll-like receptor 4 (TLR4) deficient mice are protected from adipose tissue inflammation in aging.

    Science.gov (United States)

    Ghosh, Amiya K; O'Brien, Martin; Mau, Theresa; Yung, Raymond

    2017-09-07

    Adipose tissue (AT) inflammation is a central mechanism for metabolic dysfunction in both diet-induced obesity and age-associated obesity. Studies in diet-induced obesity have characterized the role of Fetuin A (Fet A) in Free Fatty Acids (FFA)-mediated TLR4 activation and adipose tissue inflammation. However, the role of Fet A & TLR4 in aging-related adipose tissue inflammation is unknown. In the current study, analysis of epidymymal fat pads of C57/Bl6 male mice, we found that, in contrast to data from diet-induced obesity models, adipose tissue from aged mice have normal Fet A and TLR4 expression. Interestingly, aged TLR4-deficient mice have diminished adipose tissue inflammation compared to normal controls. We further demonstrated that reduced AT inflammation in old TLR4-deficient mice is linked to impaired ER stress, augmented autophagy activity, and diminished senescence phenomenon. Importantly, old TLR4-deficient mice have improved glucose tolerance compared to age-matched wild type mice, suggesting that the observed reduced AT inflammation in aged TLR4-deficient mice has important physiological consequences. Taken together, our present study establishes novel aspect of aging-associated AT inflammation that is distinct from diet-induced AT inflammation. Our results also provide strong evidence that TLR4 plays a significant role in promoting aging adipose tissue inflammation.

  1. Absence of Wip1 partially rescues Atm deficiency phenotypes in mice

    Science.gov (United States)

    Darlington, Yolanda; Nguyen, Thuy-Ai; Moon, Sung-Hwan; Herron, Alan; Rao, Pulivarthi; Zhu, Chengming; Lu, Xiongbin; Donehower, Lawrence A.

    2011-01-01

    Wildtype p53-Induced Phosphatase 1 (WIP1) is a serine/threonine phosphatase that dephosphorylates proteins in the ataxia telangiectasia mutated (ATM)-initiated DNA damage response pathway. WIP1 may play a homeostatic role in ATM signaling by returning the cell to a normal pre-stress state following completion of DNA repair. To better understand the effects of WIP1 on ATM signaling, we crossed Atm-deficient mice to Wip1-deficient mice and characterized phenotypes of the double knockout progeny. We hypothesized that the absence of Wip1 might rescue Atm deficiency phenotypes. Atm null mice, like ATM-deficient humans with the inherited syndrome ataxia telangiectasia, exhibit radiation sensitivity, fertility defects, and are T-cell lymphoma prone. Most double knockout mice were largely protected from lymphoma development and had a greatly extended lifespan compared to Atm null mice. Double knockout mice had increased p53 and H2AX phosphorylation and p21 expression compared to their Atm null counterparts, indicating enhanced p53 and DNA damage responses. Additionally, double knockout splenocytes displayed reduced chromosomal instability compared to Atm null mice. Finally, doubly null mice were partially rescued from infertility defects observed in Atm null mice. These results indicate that inhibition of WIP1 may represent a useful strategy for cancer treatment in general and A-T patients in particular. PMID:21765465

  2. Reduced metastasis of transgenic mammary cancer in urokinase-deficient mice

    DEFF Research Database (Denmark)

    Almholt, Kasper; Lund, L.R.; Rygaard, Jørgen

    2005-01-01

    A prominent phenotype of plasmin deficiency in mice is reduced metastasis in the MMTV-PymT transgenic breast cancer model. Proteolytically active plasmin is generated from inactive plasminogen by one of 2 activators, uPA or tPA. We now find that uPA deficiency alone significantly reduces metastasis...... >7-fold in the MMTV-PymT model. We studied a cohort of 55 MMTV-PymT transgenic mice, either uPA-deficient or wild-type controls. Tumor incidence, latency, growth rate and final primary tumor burden were not significantly affected by uPA deficiency. In contrast, average lung metastasis volume...

  3. Role of proopiomelanocortin neuron Stat3 in regulating arterial pressure and mediating the chronic effects of leptin.

    Science.gov (United States)

    Dubinion, John H; do Carmo, Jussara M; Adi, Ahmad; Hamza, Shereen; da Silva, Alexandre A; Hall, John E

    2013-05-01

    Although signal transducer and activator of transcription 3 (Stat3) is a key second messenger by which leptin regulates appetite and body weight, its role in specific neuronal populations in metabolic regulation and in mediating the chronic effects of leptin on blood pressure is unknown. The current study tested the hypothesis that Stat3 signaling in proopiomelanocortin (POMC) neurons mediates the chronic effects of leptin on mean arterial pressure (MAP), as well as on glucose regulation, energy expenditure, and food intake. Stat3(flox/flox) mice were crossed with POMC-Cre mice to generate mice with Stat3 deletion specifically in POMC neurons (Stat3(flox/flox)/POMC-Cre). Oxygen consumption (Vo2), carbon dioxide respiration (Vco2), motor activity, heat production, food intake, and MAP were measured 24 hours/d. After baseline measurements, leptin was infused (4 μg/kg per min, IP) for 7 days. Stat3(flox/flox)/POMC-Cre mice were hyperphagic, heavier, and had increased respiratory quotients compared with control Stat3(flox/flox) mice. Baseline MAP was not different between the groups, and chronic leptin infusion reduced food intake similarly in both groups (27 versus 29%). Vo2, Vco2, and heat production responses to leptin were not significantly different in control and Stat3(flox/flox)/POMC-Cre mice. However, leptin-mediated increases in MAP were completely abolished, and blood pressure responses to acute air-jet stress were attenuated in male Stat3(flox/flox)/POMC-Cre mice. These results indicate that Stat3 signaling in POMC neurons is essential for leptin-mediated increases in MAP, but not for anorexic or thermogenic effects of leptin.

  4. Intermittent hypoxia induces hyperlipidemia in lean mice.

    Science.gov (United States)

    Li, Jianguo; Thorne, Laura N; Punjabi, Naresh M; Sun, Cheuk-Kwan; Schwartz, Alan R; Smith, Philip L; Marino, Rafael L; Rodriguez, Annabelle; Hubbard, Walter C; O'Donnell, Christopher P; Polotsky, Vsevolod Y

    2005-09-30

    Obstructive sleep apnea, a syndrome leading to recurrent intermittent hypoxia (IH), has been associated previously with hypercholesterolemia, independent of underlying obesity. We examined the effects of experimentally induced IH on serum lipid levels and pathways of lipid metabolism in the absence and presence of obesity. Lean C57BL/6J mice and leptin-deficient obese C57BL/6J-Lep(ob) mice were exposed to IH for five days to determine changes in serum lipid profile, liver lipid content, and expression of key hepatic genes of lipid metabolism. In lean mice, exposure to IH increased fasting serum levels of total cholesterol, high-density lipoprotein (HDL) cholesterol, phospholipids (PLs), and triglycerides (TGs), as well as liver TG content. These changes were not observed in obese mice, which had hyperlipidemia and fatty liver at baseline. In lean mice, IH increased sterol regulatory element binding protein 1 (SREBP-1) levels in the liver, increased mRNA and protein levels of stearoyl-coenzyme A desaturase 1 (SCD-1), an important gene of TG and PL biosynthesis controlled by SREBP-1, and increased monounsaturated fatty acid content in serum, which indicated augmented SCD-1 activity. In addition, in lean mice, IH decreased protein levels of scavenger receptor B1, regulating uptake of cholesterol esters and HDL by the liver. We conclude that exposure to IH for five days increases serum cholesterol and PL levels, upregulates pathways of TG and PL biosynthesis, and inhibits pathways of cholesterol uptake in the liver in the lean state but does not exacerbate the pre-existing hyperlipidemia and metabolic disturbances in leptin-deficient obesity.

  5. Aldose Reductase-Deficient Mice Develop Nephrogenic Diabetes Insipidus

    Science.gov (United States)

    Ho, Horace T. B.; Chung, Sookja K.; Law, Janice W. S.; Ko, Ben C. B.; Tam, Sidney C. F.; Brooks, Heddwen L.; Knepper, Mark A.; Chung, Stephen S. M.

    2000-01-01

    Aldose reductase (ALR2) is thought to be involved in the pathogenesis of various diseases associated with diabetes mellitus, such as cataract, retinopathy, neuropathy, and nephropathy. However, its physiological functions are not well understood. We developed mice deficient in this enzyme and found that they had no apparent developmental or reproductive abnormality except that they drank and urinated significantly more than their wild-type littermates. These ALR2-deficient mice exhibited a partially defective urine-concentrating ability, having a phenotype resembling that of nephrogenic diabetes insipidus. PMID:10913167

  6. Gender affects skin wound healing in plasminogen deficient mice

    DEFF Research Database (Denmark)

    Rønø, Birgitte; Engelholm, Lars Henning; Lund, Leif Røge

    2013-01-01

    closure in female versus male plasmin deficient mice. Further studies showed that this gender effect could not be reversed by ovariectomy, suggesting that female sex-hormones did not mediate the accelerated skin wound healing in plasmin deficient female mice. Histological examination of healed wounds...... functional plasmin thus display decreased tumor growth in a variety of cancer models. Interestingly, this role of plasmin has, in regard to skin cancer, been shown to be restricted to male mice. It remains to be clarified whether gender also affects other phenotypic characteristics of plasmin deficiency...... or if this gender effect is restricted to skin cancer. To investigate this, we tested the effect of gender on plasmin dependent immune cell migration, accumulation of hepatic fibrin depositions, skin composition, and skin wound healing. Gender did not affect immune cell migration or hepatic fibrin accumulation...

  7. PLAG1 deficiency impairs spermatogenesis and sperm motility in mice.

    Science.gov (United States)

    Juma, Almas R; Grommen, Sylvia V H; O'Bryan, Moira K; O'Connor, Anne E; Merriner, D Jo; Hall, Nathan E; Doyle, Stephen R; Damdimopoulou, Pauliina E; Barriga, Daniel; Hart, Adam H; Van de Ven, Wim J M; De Groef, Bert

    2017-07-13

    Deficiency in pleomorphic adenoma gene 1 (PLAG1) leads to reduced fertility in male mice, but the mechanism by which PLAG1 contributes to reproduction is unknown. To investigate the involvement of PLAG1 in testicular function, we determined (i) the spatial distribution of PLAG1 in the testis using X-gal staining; (ii) transcriptomic consequences of PLAG1 deficiency in knock-out and heterozygous mice compared to wild-type mice using RNA-seq; and (iii) morphological and functional consequences of PLAG1 deficiency by determining testicular histology, daily sperm production and sperm motility in knock-out and wild-type mice. PLAG1 was sparsely expressed in germ cells and in Sertoli cells. Genes known to be involved in spermatogenesis were downregulated in the testes of knock-out mice, as well as Hsd17b3, which encodes a key enzyme in androgen biosynthesis. In the absence of Plag1, a number of genes involved in immune processes and epididymis-specific genes were upregulated in the testes. Finally, loss of PLAG1 resulted in significantly lowered daily sperm production, in reduced sperm motility, and in several animals, in sloughing of the germinal epithelium. Our results demonstrate that the subfertility seen in male PLAG1-deficient mice is, at least in part, the result of significantly reduced sperm output and sperm motility.

  8. Metabolic Effects of CX3CR1 Deficiency in Diet-Induced Obese Mice.

    Directory of Open Access Journals (Sweden)

    Rachana Shah

    Full Text Available The fractalkine (CX3CL1-CX3CR1 chemokine system is associated with obesity-related inflammation and type 2 diabetes, but data on effects of Cx3cr1 deficiency on metabolic pathways is contradictory. We examined male C57BL/6 Cx3cr1-/- mice on chow and high-fat diet to determine the metabolic effects of Cx3cr1 deficiency. We found no difference in body weight and fat content or feeding and energy expenditure between Cx3cr1-/- and WT mice. Cx3cr1-/- mice had reduced glucose intolerance assessed by intraperitoneal glucose tolerance tests at chow and high-fat fed states, though there was no difference in glucose-stimulated insulin values. Cx3cr1-/- mice also had improved insulin sensitivity at hyperinsulinemic-euglycemic clamp, with higher glucose infusion rate, rate of disposal, and hepatic glucose production suppression compared to WT mice. Enhanced insulin signaling in response to acute intravenous insulin injection was demonstrated in Cx3cr1-/- by increased liver protein levels of phosphorylated AKT and GSK3β proteins. There were no differences in adipose tissue macrophage populations, circulating inflammatory monocytes, adipokines, lipids, or inflammatory markers. In conclusion, we demonstrate a moderate and reproducible protective effect of Cx3cr1 deficiency on glucose intolerance and insulin resistance.

  9. Long-term correction of type 1 and 2 diabetes by central leptin gene therapy independent of effects on appetite and energy expenditure

    Directory of Open Access Journals (Sweden)

    Masako Nakano

    2012-01-01

    Full Text Available Adipocyte-derived leptin is a hormone associated with the regulation of energy homeostasis, including glucose metabolism. Hyperleptinemia, induced by the consumption of energy-enriched diets, inhibits leptin transport across the blood-brain barrier, and thereby produces leptin insufficiency in the hypothalamus. As a result of sustained leptin insufficiency, the hypothalamic restraint on pancreatic insulin secretion is lost. Additionally, both glucose metabolism and energy expenditure are also diminished, and both type 1 and type 2 diabetes are induced. A replication-deficient recombinant adeno-associated virus vector engineered to encode the leptin gene (rAVV-LEP has been used in models of diabetes as a novel therapeutic approach. After rAVV-LEP injection in ob/ob mice, hypothalamic leptin expression was increased, body weight was suppressed, and hyperinsulinemia was ameliorated. Additionally injection of rAVV-LEP into the hypothalamus suppressed the expression of orexigenic neuropeptide Y (NPY and enhanced anorexigenic pro-opiomelanocortin (POMC in the arcuate nucleus (ARC in rats. It is proposed that central leptin gene therapy should be tested clinically to reduce the worldwide epidemic of obesity, diabetes, and shortened life span. In this article, the information has been assembled from published review articles on this topic.

  10. Enhanced radiosensitivity in 1,25-dihydroxyvitamin D3 deficient mice

    International Nuclear Information System (INIS)

    Zhang Zengli; Ding Xiaofei; Tong Jian; Li Bingyan

    2011-01-01

    To investigate whether impaired osteogenesis resulting from vitamin D deficiency can influence hematopoiesis recovery after radiation, the 25-hydroxyvitamin D-1α-hydroxylase (1α-hydroxylase) gene knockout (KO) mice and wild type (WT) mice were subjected to different doses of gamma ray. The survival rates, peripheral blood cell counts and bone marrow cellularity were studied after irradiation (IR). The survival rates of the KO mice were significantly lower than that of WT mice after 6 or 8 Gy dose of radiation. The recovery of white blood cells in KO mice was significantly delayed compared with that in WT mice after radiation. The red blood cell number in WT mice was observed to increase more than that in KO mice at days 14 and 28 after radiation. The nadir platelet count in KO mice was nearly half of that in WT mice. Dramatically higher bone marrow cell numbers were found in WT mice compared with KO mice. Our findings demonstrate the enhanced radiosensitivity in 1,25-dihydroxyvitamin D3 (1,25-(OH) 2 D 3 ) deficient mice. (author)

  11. Effect of adiponectin deficiency on intestinal damage and hematopoietic responses of mice exposed to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Ponemone, Venkatesh; Fayad, Raja; Gove, Melissa E.; Pini, Maria [Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL 60612 (United States); Fantuzzi, Giamila, E-mail: giamila@uic.edu [Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL 60612 (United States)

    2010-08-07

    Adiponectin (APN) is an adipose tissue-derived cytokine that regulates insulin sensitivity and inflammation. It is also involved in modulation of cell proliferation by binding to various growth factors. Based on its known effects in modulating cell proliferation and oxidative stress, APN may potentially be involved in regulating tissue damage and repair following irradiation. Adiponectin KO mice and their WT littermates were exposed to a single whole-body dose of 3 or 6 Gy gamma radiation. Radiation-induced alterations were studied in jejunum, blood, bone marrow and thymus at days 1 and 5 post-irradiation and compared with sham-irradiated groups. In WT mice, irradiation did not significantly alter serum APN levels while inducing a significant decrease in serum leptin. Irradiation caused a significant reduction in thymocyte cellularity, with concomitant decrease in CD4{sup +}, CD8{sup +} and CD4{sup +}CD8{sup +} T cell populations, with no significant differences between WT and APN KO mice. Irradiation resulted in a significantly higher increase in the frequency of micronucleated reticulocytes in the blood of APN KO compared with WT mice, whereas frequency of micronucleated normochromatic erythrocytes in the bone marrow at day 5 was significantly higher in WT compared with APN KO mice. Finally, irradiation induced similar alterations in villus height and crypt cell proliferation in the jejunum of WT and APN KO mice. Jejunum explants from sham-irradiated APN KO mice produced higher levels of IL-6 compared with tissue from WT animals, but the difference was no longer apparent following irradiation. Our data indicate that APN deficiency does not play a significant role in modulating radiation-induced gastrointestinal injury in mice, while it may participate in regulation of damage to the hematopoietic system.

  12. Effect of adiponectin deficiency on intestinal damage and hematopoietic responses of mice exposed to gamma radiation

    International Nuclear Information System (INIS)

    Ponemone, Venkatesh; Fayad, Raja; Gove, Melissa E.; Pini, Maria; Fantuzzi, Giamila

    2010-01-01

    Adiponectin (APN) is an adipose tissue-derived cytokine that regulates insulin sensitivity and inflammation. It is also involved in modulation of cell proliferation by binding to various growth factors. Based on its known effects in modulating cell proliferation and oxidative stress, APN may potentially be involved in regulating tissue damage and repair following irradiation. Adiponectin KO mice and their WT littermates were exposed to a single whole-body dose of 3 or 6 Gy gamma radiation. Radiation-induced alterations were studied in jejunum, blood, bone marrow and thymus at days 1 and 5 post-irradiation and compared with sham-irradiated groups. In WT mice, irradiation did not significantly alter serum APN levels while inducing a significant decrease in serum leptin. Irradiation caused a significant reduction in thymocyte cellularity, with concomitant decrease in CD4 + , CD8 + and CD4 + CD8 + T cell populations, with no significant differences between WT and APN KO mice. Irradiation resulted in a significantly higher increase in the frequency of micronucleated reticulocytes in the blood of APN KO compared with WT mice, whereas frequency of micronucleated normochromatic erythrocytes in the bone marrow at day 5 was significantly higher in WT compared with APN KO mice. Finally, irradiation induced similar alterations in villus height and crypt cell proliferation in the jejunum of WT and APN KO mice. Jejunum explants from sham-irradiated APN KO mice produced higher levels of IL-6 compared with tissue from WT animals, but the difference was no longer apparent following irradiation. Our data indicate that APN deficiency does not play a significant role in modulating radiation-induced gastrointestinal injury in mice, while it may participate in regulation of damage to the hematopoietic system.

  13. Improved leptin sensitivity as a potential candidate responsible for the spontaneous food restriction of the Lou/C rat.

    Directory of Open Access Journals (Sweden)

    Christelle Veyrat-Durebex

    Full Text Available The Lou/C rat, an inbred strain of Wistar origin, was described as a model of resistance to age- and diet-induced obesity. Although such a resistance involves many metabolic parameters described in our previous studies, Lou/C rats also exhibit a spontaneous food restriction due to decreased food consumption during the nocturnal period. We then attempted to delineate the leptin sensitivity and mechanisms implicated in this strain, using different protocols of acute central and peripheral leptin administration. A first analysis of the meal patterns revealed that Lou/C rats eat smaller meals, without any change in meal number compared to age-matched Wistar animals. Although the expression of the recognized leptin transporters (leptin receptors and megalin measured in the choroid plexus was normal in Lou/C rats, the decreased triglyceridemia observed in these animals is compatible with an increased leptin transport across the blood brain barrier. Improved hypothalamic leptin signaling in Lou/C rats was also suggested by the higher pSTAT3/STAT3 (signal transducer and activator of transcription 3 ratio observed following acute peripheral leptin administration, as well as by the lower hypothalamic mRNA expression of the suppressor of cytokine signaling 3 (SOCS3, known to downregulate leptin signaling. To conclude, spontaneous hypophagia of Lou/C rats appears to be related to improved leptin sensitivity. The main mechanism underlying such a phenomenon consists in improved leptin signaling through the Ob-Rb leptin receptor isoform, which seems to consequently lead to overexpression of brain-derived neurotrophic factor (BDNF and thyrotropin-releasing hormone (TRH.

  14. Leptin and Reproduction: Past Milestones, Present Undertakings and Future Endeavors

    Science.gov (United States)

    Chehab, Farid F.

    2014-01-01

    The association between leptin and reproduction originated with the leptin-mediated correction of sterility in ob/ob mice and initiation of reproductive function in normal female mice. The uncovering of a central leptin pathway regulating food intake prompted the dissection of neuroendocrine mechanisms involving leptin in the metabolic control of reproduction. The absence of leptin receptors on GnRH neurons incited a search for intermediary neurons situated between leptin responsive and GnRH neurons. This review addresses the most significant findings that have furthered our understanding of recent progress in this new field. The role of leptin in puberty was impacted by the discovery of neurons that co-express kisspeptin, neurokinin B and dynorphin and that could act as leptin intermediates. Furthermore, the identification of first-order leptin-responsive neurons in the premammilary ventral nucleus and other brain regions opens new avenues to explore their relationship to GnRH neurons. Central to these advances is the unveiling that AgRP/NPY neurons project onto GnRH and kisspeptin neurons, allowing a crosstalk between food intake and reproduction. Finally, whereas puberty is a state of leptin sensitivity, mid-gestation represents a state of leptin resistance aimed at building energy stores to sustain pregnancy and lactation. Mechanisms underlying leptin resistance in pregnancy have lagged, however the establishment of this natural state is significant. Reproduction and energy balance are tightly controlled and backed up by redundant mechanisms that are critical for the survival of our species. It will be the goal of the next decade to shed new light on these complex and essential pathways. PMID:25118207

  15. Leptin is an effective treatment for hypothalamic amenorrhea.

    Science.gov (United States)

    Chou, Sharon H; Chamberland, John P; Liu, Xiaowen; Matarese, Giuseppe; Gao, Chuanyun; Stefanakis, Rianna; Brinkoetter, Mary T; Gong, Huizhi; Arampatzi, Kalliopi; Mantzoros, Christos S

    2011-04-19

    Hypothalamic amenorrhea (HA) is associated with dysfunction of the hypothalamic-pituitary-peripheral endocrine axes, leading to infertility and bone loss, and usually is caused by chronic energy deficiency secondary to strenuous exercise and/or decreased food intake. Energy deficiency also leads to hypoleptinemia, which has been proposed, on the basis of observational studies as well as an open-label study, to mediate the neuroendocrine abnormalities associated with this condition. To prove definitively a causal role of leptin in the pathogenesis of HA, we performed a randomized, double-blinded, placebo-controlled trial of human recombinant leptin (metreleptin) in replacement doses over 36 wk in women with HA. We assessed its effects on reproductive outcomes, neuroendocrine function, and bone metabolism. Leptin replacement resulted in recovery of menstruation and corrected the abnormalities in the gonadal, thyroid, growth hormone, and adrenal axes. We also demonstrated changes in markers of bone metabolism suggestive of bone formation, but no changes in bone mineral density were detected over the short duration of this study. If these data are confirmed, metreleptin administration in replacement doses to normalize circulating leptin levels may prove to be a safe and effective therapy for women with HA.

  16. The daidzein- and estradiol- induced anorectic action in CCK or leptin receptor deficiency rats.

    Science.gov (United States)

    Fujitani, Mina; Mizushige, Takafumi; Bhattarai, Keshab; Iwahara, Asami; Aida, Ryojiro; Kishida, Taro

    2015-01-01

    We investigated the effect of daidzein feeding and estradiol treatment on food intake in cholecystokinin-1 receptor (CCK1R) deficiency, leptin receptor (ObRb) deficiency rats and their wild-type rats. These rats underwent an ovariectomy or a sham operation. For the 5 week experiment, each rat was divided in three groups: control, daidzein (150 mg/kg diet), and estradiol (4.2 μg/rat/day) groups. In both CCK1R+ and CCK1R- rats, daidzein feeding and estradiol treatment significantly decreased food intake. Daidzein feeding significantly reduced food intake in ovariectomized ObRb- rats, although not in ObRb+ rats. Estradiol treatment significantly lowered food intake in ovariectomized ObRb+ and ObRb- rats. In the ovariectomized rats, estradiol treatment significantly increases uterine weight, while daidzein feeding did not change it, suggesting that daidzein might have no or weak estrogenic effect in our experiment. These results suggest that CCK1R and ObRb signalings were not essential for the daidzein- and estradiol-induced anorectic action.

  17. Weight-loss changes PPAR expression, reduces atherosclerosis and improves cardiovascular function in obese insulin-resistant mice

    Energy Technology Data Exchange (ETDEWEB)

    Verreth, Wim; Verhamme, Peter; Pelat, Michael; Ganame, Javier; Bielicki, John K.; Mertens, Ann; Quarck, Rozenn; Benhabiles, Nora; Marguerie, Gerard; Mackness, Bharti; Mackness, Mike; Ninio, Ewa; Herregods, Marie-Christine; Balligand, Jean-Luc; Holvoet, Paul

    2003-09-01

    Weight-loss in obese insulin-resistant, but not in insulin-sensitive, persons reduces CHD risk. It is not known to what extent changes in the adipose gene expression profile are important for reducing CHD risk. We studied the effect of diet restriction-induced weight-loss on gene expression in adipose tissue, atherosclerosis and cardiovascular function in mice with combined leptin and LDL-receptor deficiency. Obesity, hypertriglyceridemia and insulin-resistance are associated with hypertension, impaired left ventricle function and accelerated atherosclerosis in those mice. Diet restriction during 12 weeks caused a 45% weight-loss and changes in the gene expression in adipose tissue of PPARa and PPAR? and of key genes regulating glucose transport and insulin sensitivity, lipid metabolism, oxidative stress and inflammation, most of which are under the transcriptional control of PPARs. These changes were associated with increased insulin-sensitivity, decreased hypertriglyceridemia, reduced mean 24-hour blood pressure and heart rate, restored circadian variations of blood pressure and heart rate, increased ejection fraction, and reduced atherosclerosis. Thus, induction of PPARa and PPAR? in adipose tissue is a key mechanism for reducing atherosclerosis and improving cardiovascular function resulting from weight-loss. Our observations point to the critical role of PPARs in the pathogenesis of cardiovascular features of the metabolic syndrome.

  18. Inner ear dysfunction in caspase-3 deficient mice

    Directory of Open Access Journals (Sweden)

    Woo Minna

    2011-10-01

    Full Text Available Abstract Background Caspase-3 is one of the most downstream enzymes activated in the apoptotic pathway. In caspase-3 deficient mice, loss of cochlear hair cells and spiral ganglion cells coincide closely with hearing loss. In contrast with the auditory system, details of the vestibular phenotype have not been characterized. Here we report the vestibular phenotype and inner ear anatomy in the caspase-3 deficient (Casp3-/- mouse strain. Results Average ABR thresholds of Casp3-/- mice were significantly elevated (P Casp3+/- mice and Casp3+/+ mice at 3 months of age. In DPOAE testing, distortion product 2F1-F2 was significantly decreased (P Casp3-/- mice, whereas Casp3+/- and Casp3+/+ mice showed normal and comparable values to each other. Casp3-/- mice were hyperactive and exhibited circling behavior when excited. In lateral canal VOR testing, Casp3-/- mice had minimal response to any of the stimuli tested, whereas Casp3+/- mice had an intermediate response compared to Casp3+/+ mice. Inner ear anatomical and histological analysis revealed gross hypomorphism of the vestibular organs, in which the main site was the anterior semicircular canal. Hair cell numbers in the anterior- and lateral crista, and utricle were significantly smaller in Casp3-/- mice whereas the Casp3+/- and Casp3+/+ mice had normal hair cell numbers. Conclusions These results indicate that caspase-3 is essential for correct functioning of the cochlea as well as normal development and function of the vestibule.

  19. Increased susceptibility to Yersinia enterocolitica Infection of Tff2 deficient mice.

    Science.gov (United States)

    Shah, Aftab A; Mihalj, Martina; Ratkay, Ivana; Lubka-Pathak, Maria; Balogh, Peter; Klingel, Karin; Bohn, Erwin; Blin, Nikolaus; Baus-Loncar, Mirela

    2012-01-01

    TFF2 is one of the members of the trefoil factor family, known for its role in protection of gastrointestinal epithelia upon injury; however, recent studies suggest that TFF2 could also play an important role in the immune system. In the present study Tff2 deficient and wild type mice were infected by Y. enterocolitica which resulted in a lethal outcome in all Tff2 deficient mice, but not in WT animals. Yersinia invaded Peyer's patches more efficiently as shown by high bacterial titers in the KO mice while wild type mice displayed lower titers and a visible bacterial accumulation in the intestine. Bacterial accumulation in Peyer's patches of Tff2 deficient mice was accompanied by increased recruitment of macrophages. While an increased level of MAC-1 positive cells was observed in the spleens of both Tff2 deficient and WT mice at third day post infection, bacterial dissemination to liver, lung and kidneys was observed only in Tff2 knock-out mice. Analysis of the cellular composition of spleen did not reveal any substantial alteration to WT animals, suggesting possible disregulation of hemopoietic cells involved in immune response to Y. enterocolitica. These new data indicate that Tff2 plays an important role in immune response by protecting the organism from consequences of infection and that Tff2 knock-out mice react adversely to bacterial infections, in this case specifically to Y. enterocolitica. Copyright © 2012 S. Karger AG, Basel.

  20. Fucosylation Deficiency in Mice Leads to Colitis and Adenocarcinoma.

    Science.gov (United States)

    Wang, Yiwei; Huang, Dan; Chen, Kai-Yuan; Cui, Min; Wang, Weihuan; Huang, Xiaoran; Awadellah, Amad; Li, Qing; Friedman, Ann; Xin, William W; Di Martino, Luca; Cominelli, Fabio; Miron, Alex; Chan, Ricky; Fox, James G; Xu, Yan; Shen, Xiling; Kalady, Mathew F; Markowitz, Sanford; Maillard, Ivan; Lowe, John B; Xin, Wei; Zhou, Lan

    2017-01-01

    De novo synthesis of guanosine diphosphate (GDP)-fucose, a substrate for fucosylglycans, requires sequential reactions mediated by GDP-mannose 4,6-dehydratase (GMDS) and GDP-4-keto-6-deoxymannose 3,5-epimerase-4-reductase (FX or tissue specific transplantation antigen P35B [TSTA3]). GMDS deletions and mutations are found in 6%-13% of colorectal cancers; these mostly affect the ascending and transverse colon. We investigated whether a lack of fucosylation consequent to loss of GDP-fucose synthesis contributes to colon carcinogenesis. FX deficiency and GMDS deletion produce the same biochemical phenotype of GDP-fucose deficiency. We studied a mouse model of fucosylation deficiency (Fx-/- mice) and mice with the full-length Fx gene (controls). Mice were placed on standard chow or fucose-containing diet (equivalent to a control fucosylglycan phenotype). Colon tissues were collected and analyzed histologically or by enzyme-linked immunosorbent assays to measure cytokine levels; T cells also were collected and analyzed. Fecal samples were analyzed by 16s ribosomal RNA sequencing. Mucosal barrier function was measured by uptake of fluorescent dextran. We transplanted bone marrow cells from Fx-/- or control mice (Ly5.2) into irradiated 8-week-old Fx-/- or control mice (Ly5.1). We performed immunohistochemical analyses for expression of Notch and the hes family bHLH transcription factor (HES1) in colon tissues from mice and a panel of 60 human colorectal cancer specimens (27 left-sided, 33 right-sided). Fx-/- mice developed colitis and serrated-like lesions. The intestinal pathology of Fx-/- mice was reversed by addition of fucose to the diet, which restored fucosylation via a salvage pathway. In the absence of fucosylation, dysplasia appeared and progressed to adenocarcinoma in up to 40% of mice, affecting mainly the right colon and cecum. Notch was not activated in Fx-/- mice fed standard chow, leading to decreased expression of its target Hes1. Fucosylation deficiency

  1. Synchronization of the seminiferous epithelium after vitamin A replacement in vitamin A-deficient mice

    NARCIS (Netherlands)

    van Pelt, A. M.; de rooij, D. G.

    1990-01-01

    The effect of vitamin A deficiency and vitamin A replacement on spermatogenesis was studied in mice. Breeding pairs of Cpb-N mice were given a vitamin A-deficient diet for at least 4 wk. The born male mice received the same diet and developed signs of vitamin A deficiency at the age of 14-16 wk. At

  2. Sick sinus syndrome in HCN1-deficient mice.

    Science.gov (United States)

    Fenske, Stefanie; Krause, Stefanie C; Hassan, Sami I H; Becirovic, Elvir; Auer, Franziska; Bernard, Rebekka; Kupatt, Christian; Lange, Philipp; Ziegler, Tilman; Wotjak, Carsten T; Zhang, Henggui; Hammelmann, Verena; Paparizos, Christos; Biel, Martin; Wahl-Schott, Christian A

    2013-12-17

    Sinus node dysfunction (SND) is a major clinically relevant disease that is associated with sudden cardiac death and requires surgical implantation of electric pacemaker devices. Frequently, SND occurs in heart failure and hypertension, conditions that lead to electric instability of the heart. Although the pathologies of acquired SND have been studied extensively, little is known about the molecular and cellular mechanisms that cause congenital SND. Here, we show that the HCN1 protein is highly expressed in the sinoatrial node and is colocalized with HCN4, the main sinoatrial pacemaker channel isoform. To characterize the cardiac phenotype of HCN1-deficient mice, a detailed functional characterization of pacemaker mechanisms in single isolated sinoatrial node cells, explanted beating sinoatrial node preparation, telemetric in vivo electrocardiography, echocardiography, and in vivo electrophysiology was performed. On the basis of these experiments we demonstrate that mice lacking the pacemaker channel HCN1 display congenital SND characterized by bradycardia, sinus dysrhythmia, prolonged sinoatrial node recovery time, increased sinoatrial conduction time, and recurrent sinus pauses. As a consequence of SND, HCN1-deficient mice display a severely reduced cardiac output. We propose that HCN1 stabilizes the leading pacemaker region within the sinoatrial node and hence is crucial for stable heart rate and regular beat-to-beat variation. Furthermore, we suggest that HCN1-deficient mice may be a valuable genetic disease model for human SND.

  3. Hypothalamic leptin action is mediated by histone deacetylase 5

    DEFF Research Database (Denmark)

    Kabra, Dhiraj G; Pfuhlmann, Katrin; García-Cáceres, Cristina

    2016-01-01

    Hypothalamic leptin signalling has a key role in food intake and energy-balance control and is often impaired in obese individuals. Here we identify histone deacetylase 5 (HDAC5) as a regulator of leptin signalling and organismal energy balance. Global HDAC5 KO mice have increased food intake and...

  4. Bone mass regulation of leptin and postmenopausal osteoporosis with obesity.

    Science.gov (United States)

    Legiran, Siswo; Brandi, Maria Luisa

    2012-09-01

    Leptin has been known to play a role in weight regulation through food intake and energy expenditure. Leptin also has an important role in bone metabolism. The role of leptin is determined by leptin receptors, either central or peripheral to the bones. We discuss the role of leptin on bone and molecular genetics of osteoporosis in postmenopausal obese women. The role of leptin in bone preserves bone mineral density (BMD) through increased OPG levels leading to bind RANKL, resulting in reducing osteoclast activity. The estrogen role on bone is also mediated by RANKL and OPG. In postmenopausal women who have estrogen deficiency, it increases the rate of RANKL, which increases osteoclastogenesis. Obese individuals who have a high level of leptin will be effected by bone protection. There are similarities in the mechanism between estrogen and leptin in influencing the process of bone remodeling. It may be considered that the role of estrogen can be replaced by leptin. Molecular genetic aspects that play a role in bone remodeling, such as leptin, leptin receptors, cytokines (e.g. RANK, RANKL, and OPG), require further study to be useful, especially regarding osteoporosis therapy based on genetic analysis.

  5. Increasing brain serotonin corrects CO2 chemosensitivity in methyl-CpG-binding protein 2 (Mecp2)-deficient mice

    Science.gov (United States)

    Toward, Marie A.; Abdala, Ana P.; Knopp, Sharon J.; Paton, Julian F. R.; Bissonnette, John M.

    2013-01-01

    Mice deficient in the transcription factor methyl-CpG-binding protein 2 (Mecp2), a mouse model of Rett syndrome, display reduced CO2 chemosensitivity, which may contribute to their breathing abnormalities. In addition, patients with Rett syndrome and male mice that are null for Mecp2 show reduced levels of brain serotonin (5-HT). Serotonin is known to play a role in central chemosensitivity, and we hypothesized that increasing the availability of 5-HT in this mouse model would improve their respiratory response to CO2. Here we determined the apnoeic threshold in heterozygous Mecp2-deficient female mice and examined the effects of blocking 5-HT reuptake on the CO2 response in Mecp2-null male mice. Studies were performed in B6.129P2(C)-Mecp2τm1.1Bird null males and heterozygous females. In an in situ preparation, seven of eight Mecp2-deficient heterozygous females showed arrest of phrenic nerve activity when arterial CO2 was lowered to 3%, whereas the wild-types maintained phrenic nerve amplitude at 53 ± 3% of maximal. In vivo plethysmography studies were used to determine CO2 chemosensitivity in null males. These mice were exposed sequentially to 1, 3 and 5% CO2. The percentage increase in minute ventilation in response to increased inspired CO2 was less in Mecp2−/y than in Mecp2+/y mice. Pretreatment with citalopram, a selective 5-HT reuptake inhibitor (2.5 mg kg−1 I.P.), 40 min prior to CO2 exposure, in Mecp2−/y mice resulted in an improvement in CO2 chemosensitivity to wild-type levels. These results suggest that decreased 5-HT in Mecp2-deficient mice reduces CO2 chemosensitivity, and restoring 5-HT levels can reverse this effect. PMID:23180809

  6. Impaired IL-13-mediated functions of macrophages in STAT6-deficient mice.

    Science.gov (United States)

    Takeda, K; Kamanaka, M; Tanaka, T; Kishimoto, T; Akira, S

    1996-10-15

    IL-13 shares many biologic responses with IL-4. In contrast to well-characterized IL-4 signaling pathways, which utilize STAT6 and 4PS/IRS2, IL-13 signaling pathways are poorly understood. Recent studies performed with STAT6-deficient mice have demonstrated that STAT6 plays an essential role in IL-4 signaling. In this study, the functions of peritoneal macrophages of STAT6-deficient mice in response to IL-13 were analyzed. In STAT6-deficient mice, neither morphologic changes nor augmentation of MHC class II expression in response to IL-13 was observed. In addition, IL-13 did not decrease the nitric oxide production by activated macrophages. Taken together, these results suggest that the macrophage functions in response to IL-13 were impaired in STAT6-deficient mice, indicating that IL-13 and IL-4 share the signaling pathway via STAT6.

  7. Endothelial dysfunction of resistance vessels in female apolipoprotein E-deficient mice

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    Vasquez Elisardo C

    2010-05-01

    Full Text Available Abstract Background The effects of hypercholesterolemia on vasomotricity in apolipoprotein E-deficient (ApoE mice, a murine model of spontaneous atherosclerosis, are still unclear. The studies were mostly performed in conductance vessels from male mice fed a high-fat diet. In the present study, we evaluated the endothelial function of resistance vessels from normal C57BL/6 (C57 and hypercholesterolemic (ApoE female mice in both normal and ovariectomized conditions. Methods Twenty week-old C57 and ApoE mice underwent ovariectomy or sham surgery and were studied 30 days later. The vascular reactivities to norepinephrine (NE, 10-9 to 2 × 10-3 mol/L, acetylcholine (ACh and sodium nitroprusside (SNP (10-10 to 10-3 mol/L were evaluated in the isolated mesenteric arteriolar bed through dose-response curves. Results ACh-induced relaxation was significantly reduced (P 50 (-5.67 ± 0.18 vs. -6.23 ± 0.09 mol/L. Ovariectomy caused a significant impairment in ACh-induced relaxation in the C57 group (maximal response: 61 ± 4% but did not worsen the deficient state of relaxation in ApoE animals (maximal response: 39 ± 5%. SNP-induced vasorelaxation and NE-induced vasoconstriction were similar in ApoE and C57 female mice. Conclusion These data show an impairment of endothelial function in the resistance vessels of spontaneously atherosclerotic (ApoE-deficient female mice compared with normal (C57 female mice. The endothelial dysfunction in hypercholesterolemic animals was so marked that ovariectomy, which impaired endothelial function in C57 mice, did not cause additional vascular damage in ApoE-deficient mice.

  8. Wound Healing in Mac-1 Deficient Mice

    Science.gov (United States)

    2017-05-01

    Dentistry, University of Illinois at Chicago, Chicago, IL, USA. 2 Department of Defense Biotechnology High Performance Computing Software...study, we used a commercially available Mac-1 deficient strain to examine whether this deficit 5 extends to slightly smaller wounds and incisional...levels of Collagen I and Collagen III in wounds from the two strains of mice at any time point. Unwounded skin from both WT and Mac-1 -/- mice contained

  9. Presynaptic Regulation of Leptin in a Defined Lateral Hypothalamus-Ventral Tegmental Area Neurocircuitry Depends on Energy State.

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    Liu, Jing-Jing; Bello, Nicholas T; Pang, Zhiping P

    2017-12-06

    Synaptic transmission controls brain activity and behaviors, including food intake. Leptin, an adipocyte-derived hormone, acts on neurons located in the lateral hypothalamic area (LHA) to maintain energy homeostasis and regulate food intake behavior. The specific synaptic mechanisms, cell types, and neural projections mediating this effect remain unclear. In male mice, using pathway-specific retrograde tracing, whole-cell patch-clamp recordings and post hoc cell type identification, we found that leptin reduces excitatory synaptic strength onto both melanin-concentrating hormone- and orexin-expressing neurons projecting from the LHA to the ventral tegmental area (VTA), which may affect dopamine signaling and motivation for feeding. A presynaptic mechanism mediated by distinct intracellular signaling mechanisms may account for this regulation by leptin. The regulatory effects of leptin depend on intact leptin receptor signaling. Interestingly, the synaptic regulatory function of leptin in the LHA-to-VTA neuronal pathway is highly sensitive to energy states: both energy deficiency (acute fasting) and excessive energy storage (high-fat diet-induced obesity) blunt the effect of leptin. These data revealed that leptin may regulate synaptic transmission in the LHA-to-VTA neurocircuitry in an inverted "U-shape" fashion dependent on plasma glucose levels and related to metabolic states. SIGNIFICANCE STATEMENT The lateral hypothalamic area (LHA) to ventral tegmental area (VTA) projection is an important neural pathway involved in balancing whole-body energy states and reward. We found that the excitatory synaptic inputs to both orexin- and melanin-concentrating hormone expressing LHA neurons projecting to the VTA were suppressed by leptin, a peptide hormone derived from adipocytes that signals peripheral energy status to the brain. Interestingly, energy states seem to affect how leptin regulates synaptic transmission since both the depletion of energy induced by acute food

  10. Functional substitution by TAT-utrophin in dystrophin-deficient mice.

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    Kevin J Sonnemann

    2009-05-01

    Full Text Available The loss of dystrophin compromises muscle cell membrane stability and causes Duchenne muscular dystrophy and/or various forms of cardiomyopathy. Increased expression of the dystrophin homolog utrophin by gene delivery or pharmacologic up-regulation has been demonstrated to restore membrane integrity and improve the phenotype in the dystrophin-deficient mdx mouse. However, the lack of a viable therapy in humans predicates the need to explore alternative methods to combat dystrophin deficiency. We investigated whether systemic administration of recombinant full-length utrophin (Utr or DeltaR4-21 "micro" utrophin (muUtr protein modified with the cell-penetrating TAT protein transduction domain could attenuate the phenotype of mdx mice.Recombinant TAT-Utr and TAT-muUtr proteins were expressed using the baculovirus system and purified using FLAG-affinity chromatography. Age-matched mdx mice received six twice-weekly intraperitoneal injections of either recombinant protein or PBS. Three days after the final injection, mice were analyzed for several phenotypic parameters of dystrophin deficiency. Injected TAT-muUtr transduced all tissues examined, integrated with members of the dystrophin complex, reduced serum levels of creatine kinase (11,290+/-920 U versus 5,950+/-1,120 U; PBS versus TAT, the prevalence of muscle degeneration/regeneration (54%+/-5% versus 37%+/-4% of centrally nucleated fibers; PBS versus TAT, the susceptibility to eccentric contraction-induced force drop (72%+/-5% versus 40%+/-8% drop; PBS versus TAT, and increased specific force production (9.7+/-1.1 N/cm(2 versus 12.8+/-0.9 N/cm(2; PBS versus TAT.These results are, to our knowledge, the first to establish the efficacy and feasibility of TAT-utrophin-based constructs as a novel direct protein-replacement therapy for the treatment of skeletal and cardiac muscle diseases caused by loss of dystrophin.

  11. Concentrating carbohydrates before sleep improves feeding regulation and metabolic and inflammatory parameters in mice.

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    Sofer, Sigal; Eliraz, Abraham; Madar, Zecharia; Froy, Oren

    2015-10-15

    New evidance highlights the importance of food timing. Recently, we showed that a low-calorie diet with carbohydrates eaten mostly at dinner changed diurnal hormone secretion and led to greater weight loss and improved metabolic status in obese people. Herein, we set out to test whether concentrated-carbohydrates diet (CCD), in which carbohydrates are fed only before sleep, leads to an improved metabolic status in mouse hypothalamus and peripheral tissues. Diet-induced obese mice were given concentrated or distributed carbohydrate diet for 6 weeks. Obese mice fed CCD ate 8.3% less, were 9.3% leaner and had 39.7% less fat mass. Leptin, ghrelin and adiponectin displayed altered secretion. In addition, these mice exhibited an improved biochemical and inflammatory status. In the hypothalamus, anorexigenic signals were up-regulated and orexigenic signals were down-regulated. In peripheral tissues, CCD promoted adiponectin signaling, repressed gluconeogenesis, enhanced lipid oxidation and lowered inflammation, thus ameliorating the major risk factors of obesity. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  12. PD-L1 Deficiency within Islets Reduces Allograft Survival in Mice.

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    Dongxia Ma

    Full Text Available Islet transplantation may potentially cure type 1 diabetes mellitus (T1DM. However, immune rejection, especially that induced by the alloreactive T-cell response, remains a restraining factor for the long-term survival of grafted islets. Programmed death ligand-1 (PD-L1 is a negative costimulatory molecule. PD-L1 deficiency within the donor heart accelerates allograft rejection. Here, we investigate whether PD-L1 deficiency in donor islets reduces allograft survival time.Glucose Stimulation Assays were performed to evaluate whether PD-L1 deficiency has detrimental effects on islet function. Islets isolated from PDL1-deficient mice or wild- type (WT mice (C57BL/6j were implanted beneath the renal capsule of streptozotocin (STZ-induced diabetic BALB/c mice. Blood glucose levels and graft survival time after transplantation were monitored. Moreover, we analyzed the residual islets, infiltrating immune cells and alloreactive cells from the recipients.PD-L1 deficiency within islets does not affect islet function. However, islet PD-L1 deficiency increased allograft rejection and was associated with enhanced inflammatory cell infiltration and recipient T-cell alloreactivity.This is the first report to demonstrate that PD-L1 deficiency accelerated islet allograft rejection and regulated recipient alloimmune responses.

  13. Strategies to rescue the consequences of inducible arginase-1 deficiency in mice.

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    Laurel L Ballantyne

    Full Text Available Arginase-1 catalyzes the conversion of arginine to ornithine and urea, which is the final step of the urea cycle used to remove excess ammonia from the body. Arginase-1 deficiency leads to hyperargininemia in mice and man with severe lethal consequences in the former and progressive neurological impairment to varying degrees in the latter. In a tamoxifen-induced arginase-1 deficient mouse model, mice succumb to the enzyme deficiency within 2 weeks after inducing the knockout and retain <2 % enzyme in the liver. Standard clinical care regimens for arginase-1 deficiency (low-protein diet, the nitrogen-scavenging drug sodium phenylbutyrate, ornithine supplementation either failed to extend lifespan (ornithine or only minimally prolonged lifespan (maximum 8 days with low-protein diet and drug. A conditional, tamoxifen-inducible arginase-1 transgenic mouse strain expressing the enzyme from the Rosa26 locus modestly extended lifespan of neonatal mice, but not that of 4-week old mice, when crossed to the inducible arginase-1 knockout mouse strain. Delivery of an arginase-1/enhanced green fluorescent fusion construct by adeno-associated viral delivery (rh10 serotype with a strong cytomegalovirus-chicken β-actin hybrid promoter rescued about 30% of male mice with lifespan prolongation to at least 6 months, extensive hepatic expression and restoration of significant enzyme activity in liver. In contrast, a vector of the AAV8 serotype driven by the thyroxine-binding globulin promoter led to weaker liver expression and did not rescue arginase-1 deficient mice to any great extent. Since the induced arginase-1 deficient mouse model displays a much more severe phenotype when compared to human arginase-1 deficiency, these studies reveal that it may be feasible with gene therapy strategies to correct the various manifestations of the disorder and they provide optimism for future clinical studies.

  14. SAP deficiency mitigated atherosclerotic lesions in ApoE(-/-) mice.

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    Zheng, Lingyun; Wu, Teng; Zeng, Cuiling; Li, Xiangli; Li, Xiaoqiang; Wen, Dingwen; Ji, Tianxing; Lan, Tian; Xing, Liying; Li, Jiangchao; He, Xiaodong; Wang, Lijing

    2016-01-01

    Serum amyloid P conpoent (SAP), a member of the pentraxin family, interact with pathogens and cell debris to promote their removal by macrophages and neutrophils and is co-localized with atherosclerotic plaques in patients. However, the exact mechanism of SAP in atherogenesis is still unclear. We investigated whether SAP influence macrophage recruitment and foam cell formation and ultimately affect atherosclerotic progression. we generated apoE(-/-); SAP(-/-) (DKO) mice and fed them western diet for 4 and 8 weeks to characterize atherosclerosis development. SAP deficiency effectively reduced plaque size both in the aorta (p = 0.0006 for 4 wks; p = 0.0001 for 8 wks) and the aortic root (p = 0.0061 for 4 wks; p = 0.0079 for 8wks) compared with apoE(-/-) mice. Meanwhile, SAP deficiency inhibited oxLDL-induced foam cell formation (p = 0.0004) compared with apoE(-/-) mice and SAP treatment increases oxLDL-induced foam cell formation (p = 0.002) in RAW cells. Besides, SAP deficiency reduced macrophages recruitment (p = 0.035) in vivo and in vitro (p = 0.026). Furthermore, SAP treatment enhanced CD36 (p = 0.007) and FcγRI (p = 0.031) expression induced by oxLDL through upregulating JNK and p38 MAPK phosphorylation whereas specific JNK1/2 inhibitor reduced CD36 (p = 0.0005) and FcγRI (P = 0.0007) expression in RAW cell. SAP deficiency also significantly decreased the expression of M1 and M2 macrophage markers and inflammatory cytokines in oxLDL-induced macrophages. SAP deficiency mitigated foam cell formation and atherosclerotic development in apoE(-/-) mice, due to reduction in macrophages recruitment, polarization and pro-inflammatory cytokines and inhibition the CD36/FcγR-dependent signaling pathway. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  15. Adipocyte Versus Pituitary Leptin in the Regulation of Pituitary Hormones: Somatotropes Develop Normally in the Absence of Circulating Leptin

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    Odle, Angela K.; Haney, Anessa; Allensworth-James, Melody; Akhter, Noor

    2014-01-01

    Leptin is a cytokine produced by white fat cells, skeletal muscle, the placenta, and the pituitary gland among other tissues. Best known for its role in regulating appetite and energy expenditure, leptin is produced largely by and in proportion to white fat cells. Leptin is also important to the maintenance and function of the GH cells of the pituitary. This was shown when the deletion of leptin receptors on somatotropes caused decreased numbers of GH cells, decreased circulating GH, and adult-onset obesity. To determine the source of leptin most vital to GH cells and other pituitary cell types, we compared two different leptin knockout models with Cre-lox technology. The global Lep-null model is like the ob/ob mouse, whereby only the entire exon 3 is deleted. The selective adipocyte-Lep-null model lacks adipocyte leptin but retains pituitary leptin, allowing us to investigate the pituitary as a potential source of circulating leptin. Male and female mice lacking adipocyte leptin (Adipocyte-lep-null) did not produce any detectable circulating leptin and were infertile, suggesting that the pituitary does not contribute to serum levels. In the presence of only pituitary leptin, however, these same mutants were able to maintain somatotrope numbers and GH mRNA levels. Serum GH trended low, but values were not significant. However, hypothalamic GHRH mRNA was significantly reduced in these animals. Other serum hormone and pituitary mRNA differences were observed, some of which varied from previous results reported in ob/ob animals. Whereas pituitary leptin is capable of maintaining somatotrope numbers and GH mRNA production, the decreased hypothalamic GHRH mRNA and low (but not significant) serum GH levels indicate an important role for adipocyte leptin in the regulation of GH secretion in the mouse. Thus, normal GH secretion may require the coordinated actions of both adipocyte and pituitary leptin. PMID:25116704

  16. Attentional processing in C57BL/6J mice exposed to developmental vitamin D deficiency.

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    Lauren R Harms

    Full Text Available Epidemiological evidence suggests that Developmental Vitamin D (DVD deficiency is associated with an increased risk of schizophrenia. DVD deficiency in mice is associated with altered behaviour, however there has been no detailed investigation of cognitive behaviours in DVD-deficient mice. The aim of this study was to determine the effect of DVD deficiency on a range of cognitive tasks assessing attentional processing in C57BL/6J mice. DVD deficiency was established by feeding female C57BL/6J mice a vitamin D-deficient diet from four weeks of age. After six weeks on the diet, vitamin D-deficient and control females were mated with vitamin D-normal males and upon birth of the pups, all dams were returned to a diet containing vitamin D. The adult offspring were tested on a range of cognitive behavioural tests, including the five-choice serial reaction task (5C-SRT and five-choice continuous performance test (5C-CPT, as well as latent inhibition using a fear conditioning paradigm. DVD deficiency was not associated with altered attentional performance on the 5C-SRT. In the 5C-CPT DVD-deficient male mice exhibited an impairment in inhibiting repetitive responses by making more perseverative responses, with no changes in premature or false alarm responding. DVD deficiency did not affect the acquisition or retention of cued fear conditioning, nor did it affect the expression of latent inhibition using a fear conditioning paradigm. DVD-deficient mice exhibited no major impairments in any of the cognitive domains tested. However, impairments in perseverative responding in DVD-deficient mice may indicate that these animals have specific alterations in systems governing compulsive or reward-seeking behaviour.

  17. IL-25 inhibits atherosclerosis development in apolipoprotein E deficient mice.

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    Polyxeni T Mantani

    Full Text Available IL-25 has been implicated in the initiation of type 2 immunity and in the protection against autoimmune inflammatory diseases. Recent studies have identified the novel innate lymphoid type 2 cells (ILC2s as an IL-25 target cell population. The purpose of this study was to evaluate if IL-25 has any influence on atherosclerosis development in mice.Administration of 1 μg IL-25 per day for one week to atherosclerosis-prone apolipoprotein (apoE deficient mice, had limited effect on the frequency of T cell populations, but resulted in a large expansion of ILC2s in the spleen. The expansion was accompanied by increased levels of anti-phosphorylcholine (PC natural IgM antibodies in plasma and elevated levels of IL-5 in plasma and spleen. Transfer of ILC2s to apoE deficient mice elevated the natural antibody-producing B1a cell population in the spleen. Treatment of apoE/Rag-1 deficient mice with IL-25 was also associated with extensive expansion of splenic ILC2s and increased plasma IL-5, suggesting ILC2s to be the source of IL-5. Administration of IL-25 in IL-5 deficient mice resulted in an expanded ILC2 population, but did not stimulate generation of anti-PC IgM, indicating that IL-5 is not required for ILC2 expansion but for the downstream production of natural antibodies. Additionally, administration of 1 μg IL-25 per day for 4 weeks in apoE deficient mice reduced atherosclerosis in the aorta both during initiation and progression of the disease.The present findings demonstrate that IL-25 has a protective role in atherosclerosis mediated by innate responses, including ILC2 expansion, increased IL-5 secretion, B1a expansion and natural anti-PC IgM generation, rather than adaptive Th2 responses.

  18. Age-related retinopathy in NRF2-deficient mice.

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    Zhenyang Zhao

    2011-04-01

    Full Text Available Cumulative oxidative damage is implicated in the pathogenesis of age-related macular degeneration (AMD. Nuclear factor erythroid 2-related factor 2 (NRF2 is a transcription factor that plays key roles in retinal antioxidant and detoxification responses. The purposes of this study were to determine whether NRF2-deficient mice would develop AMD-like retinal pathology with aging and to explore the underlying mechanisms.Eyes of both wild type and Nrf2(-/- mice were examined in vivo by fundus photography and electroretinography (ERG. Structural changes of the outer retina in aged animals were examined by light and electron microscopy, and immunofluorescence labeling. Our results showed that Nrf2(-/- mice developed age-dependent degenerative pathology in the retinal pigment epithelium (RPE. Drusen-like deposits, accumulation of lipofuscin, spontaneous choroidal neovascularization (CNV and sub-RPE deposition of inflammatory proteins were present in Nrf2(-/- mice after 12 months. Accumulation of autophagy-related vacuoles and multivesicular bodies was identified by electron microscopy both within the RPE and in Bruch's membrane of aged Nrf2(-/- mice.Our data suggest that disruption of Nfe2l2 gene increased the vulnerability of outer retina to age-related degeneration. NRF2-deficient mice developed ocular pathology similar to cardinal features of human AMD and deregulated autophagy is likely a mechanistic link between oxidative injury and inflammation. The Nrf2(-/- mice can provide a novel model for mechanistic and translational research on AMD.

  19. IMPORTANCE OF THE LEPTIN/GRELIN RATIO AS A BIOMARKER IN DIETARY INDUCED HYPERLIPIDEMIA IN FEMALE C57Black/6 MICE

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    N. A. Riger

    2018-01-01

    Full Text Available Visceral obesity, dyslipidemia and insulin resistance are considered the main causes of metabolic disorders in metabolic syndrome. Leptin and ghrelin are the most important factors involved in regulation of the metabolic processes. The purpose of this study was to evaluate the significance of leptin-to-ghrelin ratio (L/Gh and cytokine profiles as biomarkers of metabolic and immune disorders in an in vivo model of a dietary induced dyslipidemia in mice.The studies were carried out on 48 female C57Black/6 mice, which were divided into 6 groups of 8 animals. Group 1 (control received the AIN93 diet; group 2, excess fat administration (30% dry weight; the mice from group 3 were supplied with 20% fructose in drinking water added to the main diet; group 4 got fats and fructose excess, group 5, cholesterol excess (0.5% dry weight; group 6 was fed with cholesterol and fructose in excess. Duration of the experiment was 63 days. In all animals, the relative mass of internal organs was determined. The levels of cytokines, leptin and ghrelin in plasma were determined by means of Luminex 200 analyzer using Bio-Plex kits.There were no significant differences for plasma leptin and ghrelin concentrations between the control and most of experimental groups, except of the 6th group (combined diet with excess fructose and cholesterol which a significantly lower leptin levels as compared to the controls (group 6: 2.12 pg/ml, min 1.57 – max 3.83 vs group 1: 3.92 pg/ml, min 2.45 – max 27.88, p < 0.05. The changes in plasma ghrelin contents, depending on the diet, showed a generally opposite trend when compared to leptin levels.The value of L/Gh ratio in mice fed with excess fat (group 2 and cholesterol (group 5 showed a statistically unsignificant trend for increase. Fructose added to a diet with fat or cholesterol excess caused a significant decrease in L/Gh ratio (p < 0.05. In animals of the 6th group (fructose + cholesterol with minimal L/Gh values, the lowest

  20. Insulin and Leptin Signaling Interact in the Mouse Kiss1 Neuron during the Peripubertal Period.

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    Xiaoliang Qiu

    Full Text Available Reproduction requires adequate energy stores for parents and offspring to survive. Kiss1 neurons, which are essential for fertility, have the potential to serve as the central sensors of metabolic factors that signal to the reproductive axis the presence of stored calories. Paradoxically, obesity is often accompanied by infertility. Despite excess circulating levels of insulin and leptin, obese individuals exhibit resistance to both metabolic factors in many neuron types. Thus, resistance to insulin or leptin in Kiss1 neurons could lead to infertility. Single deletion of the receptors for either insulin or the adipokine leptin from Kiss1 neurons does not impair adult reproductive dysfunction. However, insulin and leptin signaling pathways may interact in such a way as to obscure their individual functions. We hypothesized that in the presence of genetic or obesity-induced concurrent insulin and leptin resistance, Kiss1 neurons would be unable to maintain reproductive function. We therefore induced a chronic hyperinsulinemic and hyperleptinemic state in mice lacking insulin receptors in Kiss1 neurons through high fat feeding and examined the impact on fertility. In an additional, genetic model, we ablated both leptin and insulin signaling in Kiss1 neurons (IR/LepRKiss mice. Counter to our hypothesis, we found that the addition of leptin insensitivity did not alter the reproductive phenotype of IRKiss mice. We also found that weight gain, body composition, glucose and insulin tolerance were normal in mice of both genders. Nonetheless, leptin and insulin receptor deletion altered pubertal timing as well as LH and FSH levels in mid-puberty in a reciprocal manner. Our results confirm that Kiss1 neurons do not directly mediate the critical role that insulin and leptin play in reproduction. However, during puberty kisspeptin neurons may experience a critical window of susceptibility to the influence of metabolic factors that can modify the onset of

  1. Effects of genetic deficiency of cyclooxygenase-1 or cyclooxygenase-2 on functional and histological outcomes following traumatic brain injury in mice

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    Scheff Stephen W

    2009-08-01

    Full Text Available Abstract Background Neuroinflammation contributes to the pathophysiology of acute CNS injury, including traumatic brain injury (TBI. Although prostaglandin lipid mediators of inflammation contribute to a variety of inflammatory responses, their importance in neuroinflammation is not clear. There are conflicting reports as to the efficacy of inhibiting the enzymes required for prostaglandin formation, cyclooxygenase (COX -1 and COX-2, for improving outcomes following TBI. The purpose of the current study was to determine the role of the COX isoforms in contributing to pathological processes resulting from TBI by utilizing mice deficient in COX-1 or COX-2. Results Following a mild controlled cortical impact injury, the amount of cortical tissue loss, the level of microglial activation, and the capacity for functional recovery was compared between COX-1-deficient mice or COX-2-deficient mice, and their matching wild-type controls. The deficiency of COX-2 resulted in a minor (6%, although statistically significant, increase in the sparing of cortical tissue following TBI. The deficiency of COX-1 resulted in no detectable effect on cortical tissue loss following TBI. As determined by 3[H]-PK11195 autoradiography, TBI produced a similar increase in microglial activation in multiple brain regions of both COX-1 wild-type and COX-1-deficient mice. In COX-2 wild-type and COX-2-deficient mice, TBI increased 3[H]-PK11195 binding in all brain regions that were analyzed. Following injury, 3[H]-PK11195 binding in the dentate gyrus and CA1 region of the hippocampus was greater in COX-2-deficient mice, as compared to COX-2 wild-type mice. Cognitive assessment was performed in the wild-type, COX-1-deficient and COX-2-deficient mice following 4 days of recovery from TBI. There was no significant cognitive effect that resulted from the deficiency of either COX-1 or COX-2, as determined by acquisition and spatial memory retention testing in a Morris water maze

  2. COMP-angiopoietin-1 recovers molecular biomarkers of neuropathy and improves vascularisation in sciatic nerve of ob/ob mice.

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    Joanna Kosacka

    Full Text Available BACKGROUND: Leptin-deficient ob/ob mice are a model of type 2 diabetes induced peripheral neuropathy. Ob/ob mice exhibit obesity, insulin resistance, hyperglycaemia, and alterations of peripheral nerve fibres and endoneural microvessels. Here we test the hypothesis that cartilage oligomeric matrix protein (COMP-Ang-1, a soluble and stabile form of Ang-1 which promotes angiogenesis and nerve growth, improves regeneration of nerve fibres and endoneural microvessels in ob/ob mice. METHODS AND FINDINGS: COMP-Ang-1 (100 ng/ml or NaCl were intraperitoneally (i.p. injected into male (N = 184, 3-month old, ob/ob or ob/+ mice for 7 and 21 days. We measured expression of Nf68, GAP43, Cx32, Cx26, Cx43, and TNFα in sciatic nerves using Western blot analysis. To investigate the inflammation in sciatic nerves, numbers of macrophages and T-cells were counted after immunofluorescence staining. In ultrathin section, number of myelinated/non-mylinated nerve fibers, g-ratio, the thickness of Schwann cell basal lamina and microvessel endothelium were investigated. Endoneural microvessels were reconstructed with intracardial FITC injection. Treatment with COMP-Ang-1 over 21 days significantly reduced fasting blood glucose and plasma cholesterol concentrations compared to saline treated ob/ob mice. In addition, COMP-Ang-1 treatment: 1 up-regulated expression of Nf68 and GAP43; 2 improved expression of gap junction proteins including connexin 32 and 26; 3 suppressed the expression of TNFα and Cx43 and 4 led to decreased macrophage and T-cell infiltration in sciatic nerve of ob/ob mice. The significant changes of sciatic nerve ultrastructure were not observed after 21-day long COMP-Ang-1 treatment. COMP-Ang-1 treated ob/ob mice displayed regeneration of small-diameter endoneural microvessels. Effects of COMP-Ang-1 corresponded to increased phosphorylation of Akt and p38 MAPK upon Tie-2 receptor. CONCLUSIONS: COMP-Ang-1 recovers molecular biomarkers of neuropathy

  3. Amelioration of behavioral abnormalities in BH(4-deficient mice by dietary supplementation of tyrosine.

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    Sang Su Kwak

    Full Text Available This study reports an amelioration of abnormal motor behaviors in tetrahydrobiopterin (BH4-deficient Spr (-/- mice by the dietary supplementation of tyrosine. Since BH4 is an essential cofactor for the conversion of phenylalanine into tyrosine as well as the synthesis of dopamine neurotransmitter within the central nervous system, the levels of tyrosine and dopamine were severely reduced in brains of BH4-deficient Spr (-/- mice. We found that Spr (-/- mice display variable 'open-field' behaviors, impaired motor functions on the 'rotating rod', and dystonic 'hind-limb clasping'. In this study, we report that these aberrant motor deficits displayed by Spr (-/- mice were ameliorated by the therapeutic tyrosine diet for 10 days. This study also suggests that dopamine deficiency in brains of Spr (-/- mice may not be the biological feature of aberrant motor behaviors associated with BH4 deficiency. Brain levels of dopamine (DA and its metabolites in Spr (-/- mice were not substantially increased by the dietary tyrosine therapy. However, we found that mTORC1 activity severely suppressed in brains of Spr (-/- mice fed a normal diet was restored 10 days after feeding the mice the tyrosine diet. The present study proposes that brain mTORC1 signaling pathway is one of the potential targets in understanding abnormal motor behaviors associated with BH4-deficiency.

  4. Effects of Nrf2 deficiency on arsenic metabolism in mice.

    Science.gov (United States)

    Wang, Huihui; Zhu, Jiayu; Li, Lu; Li, Yongfang; Lv, Hang; Xu, Yuanyuan; Sun, Guifan; Pi, Jingbo

    2017-12-15

    Inorganic arsenic (iAs) is a known toxicant and carcinogen. Worldwide arsenic exposure has become a threat to human health. The severity of arsenic toxicity is strongly correlated with the speed of arsenic metabolism (methylation) and clearance. Furthermore, oxidative stress is recognized as a major mechanism for arsenic-induced toxicity. Nuclear factor-E2-related factor 2 (Nrf2), a key regulator in cellular adaptive antioxidant response, is clearly involved in alleviation of arsenic-induced oxidative damage. Multiple studies demonstrate that Nrf2 deficiency mice are more vulnerable to arsenic-induced intoxication. However, what effect Nrf2 deficiency might have on arsenic metabolism in mice is still unknown. In the present study, we measured the key enzymes involved in arsenic metabolism in Nrf2-WT and Nrf2-KO mice. Our results showed that basal transcript levels of glutathione S-transferase omega 2 (Gsto2) were significantly higher and GST mu 1 (Gstm1) lower in Nrf2-KO mice compared to Nrf2-WT control. Arsenic speciation and methylation rate in liver and urine was then studied in mice treated with 5mg/kg sodium arsenite for 12h. Although there were some alterations in arsenic metabolism enzymes between Nrf2-WT and Nrf2-KO mice, the Nrf2 deficiency had no significant effect on arsenic methylation. These results suggest that the Nrf2-KO mice are more sensitive to arsenic than Nrf2-WT mainly because of differences in adaptive antioxidant detoxification capacity rather than arsenic methylation capacity. Copyright © 2017. Published by Elsevier Inc.

  5. Restoration of leptin responsiveness in diet-induced obese mice using an optimized leptin analog in combination with exendin-4 or FGF21

    NARCIS (Netherlands)

    Müller, Timo D.; Sullivan, Lorraine M.; Habegger, Kirk; Yi, Chun-Xia; Kabra, Dhiraj; Grant, Erin; Ottaway, Nickki; Krishna, Radha; Holland, Jenna; Hembree, Jazzminn; Perez-Tilve, Diego; Pfluger, Paul T.; DeGuzman, Michael J.; Siladi, Marc E.; Kraynov, Vadim S.; Axelrod, Douglas W.; DiMarchi, Richard; Pinkstaff, Jason K.; Tschöp, Matthias H.

    2012-01-01

    The identification of leptin as a mediator of body weight regulation provided much initial excitement for the treatment of obesity. Unfortunately, leptin monotherapy is insufficient in reversing obesity in rodents or humans. Recent findings suggest that amylin is able to restore leptin sensitivity

  6. Cadm2 regulates body weight and energy homeostasis in mice

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    Xin Yan

    2018-02-01

    Full Text Available Objective: Obesity is strongly linked to genes regulating neuronal signaling and function, implicating the central nervous system in the maintenance of body weight and energy metabolism. Genome-wide association studies identified significant associations between body mass index (BMI and multiple loci near Cell adhesion molecule2 (CADM2, which encodes a mediator of synaptic signaling enriched in the brain. Here we sought to further understand the role of Cadm2 in the pathogenesis of hyperglycemia and weight gain. Methods: We first analyzed Cadm2 expression in the brain of both human subjects and mouse models and subsequently characterized a loss-of-function mouse model of Cadm2 for alterations in glucose and energy homeostasis. Results: We show that the risk variant rs13078960 associates with increased CADM2 expression in the hypothalamus of human subjects. Increased Cadm2 expression in several brain regions of Lepob/ob mice was ameliorated after leptin treatment. Deletion of Cadm2 in obese mice (Cadm2/ob resulted in reduced adiposity, systemic glucose levels, and improved insulin sensitivity. Cadm2-deficient mice exhibited increased locomotor activity, energy expenditure rate, and core body temperature identifying Cadm2 as a potent regulator of systemic energy homeostasis. Conclusions: Together these data illustrate that reducing Cadm2 expression can reverse several traits associated with the metabolic syndrome including obesity, insulin resistance, and impaired glucose homeostasis. Keywords: Cadm2/SynCAM2, Energy homeostasis, Insulin sensitivity, Genome-wide association studies, Leptin signaling

  7. Cross-talk between estrogen and leptin signaling in the hypothalamus.

    Science.gov (United States)

    Gao, Qian; Horvath, Tamas L

    2008-05-01

    Obesity, characterized by enhanced food intake (hyperphagia) and reduced energy expenditure that results in the accumulation of body fat, is a major risk factor for various diseases, including diabetes, cardiovascular disease, and cancer. In the United States, more than half of adults are overweight, and this number continues to increase. The adipocyte-secreted hormone leptin and its downstream signaling mediators play crucial roles in the regulation of energy balance. Leptin decreases feeding while increasing energy expenditure and permitting energy-intensive neuroendocrine processes, such as reproduction. Thus, leptin also modulates the neuroendocrine reproductive axis. The gonadal steroid hormone estrogen plays a central role in the regulation of reproduction and also contributes to the regulation of energy balance. Estrogen deficiency promotes feeding and weight gain, and estrogen facilitates, and to some extent mimics, some actions of leptin. In this review, we examine the functions of estrogen and leptin in the brain, with a focus on mechanisms by which leptin and estrogen cooperate in the regulation of energy homeostasis.

  8. A synthetic fragment of leptin increase hematopoietic stem cell population and improve its engraftment ability.

    Science.gov (United States)

    Dias, Carolina C; Nogueira-Pedro, Amanda; Tokuyama, Paula Yumi; Martins, Marta N C; Segreto, Helena Regina Comodo; Buri, Marcus V; Miranda, Antonio; Paredes-Gamero, Edgar J

    2015-07-01

    Several studies have shown the important actions of cytokine leptin that regulates food intake and energy expenditure. Additionally, the ability to modulate hematopoiesis has also been demonstrated. Previous reports have shown that some synthetic sequences of leptin molecules can activate leptin receptor. Herein, decapeptides encompassing amino acids from positions 98 to 122 of the leptin molecule were constructed to evaluate their effects on hematopoiesis. Among them, the synthetic peptide Lep(110-119)-NH2 (LEP F) was the only peptide that possessed the ability to increase the percentage of hematopoietic stem cells (HSC). Moreover, LEP F also produced an increase of granulocyte/macrophage colony-forming units and activated leptin receptor. Furthermore, LEP F also improves the grafting of HSC in bone marrow, but did not accelerate the recovery of bone marrow after ablation with 5-fluorouracil. These results show that LEP F is a positive modulator of the in vivo expansion of HSC and could be useful in bone marrow transplantation. © 2015 Wiley Periodicals, Inc.

  9. Reduced hepatic tumor incidence in cyclin G1-deficient mice

    DEFF Research Database (Denmark)

    Jensen, Michael Rugaard; Factor, Valentina M; Fantozzi, Anna

    2003-01-01

    found that the p53 levels in the cyclin G1-deficient mice are 2-fold higher that in wild-type mice. Moreover, we showed that treatment of mice with the alkylating agent 1,4-bis[N,N'-di(ethylene)-phosphamide]piperazine (Dipin), followed by partial hepatectomy, decreased G1-S transition in cyclin G1-null...

  10. Impaired bone formation in Pdia3 deficient mice.

    Directory of Open Access Journals (Sweden)

    Yun Wang

    Full Text Available 1α,25-Dihydroxyvitamin D3 [1α,25(OH2D3] is crucial for normal skeletal development and bone homeostasis. Protein disulfide isomerase family A, member 3 (PDIA3 mediates 1α,25(OH2D3 initiated-rapid membrane signaling in several cell types. To understand its role in regulating skeletal development, we generated Pdia3-deficient mice and examined the physiologic consequence of Pdia3-disruption in embryos and Pdia3+/- heterozygotes at different ages. No mice homozygous for the Pdia3-deletion were found at birth nor were there embryos after E12.5, indicating that targeted disruption of the Pdia3 gene resulted in early embryonic lethality. Pdia3-deficiency also resulted in skeletal manifestations as revealed by µCT analysis of the tibias. In comparison to wild type mice, Pdia3 heterozygous mice displayed expanded growth plates associated with decreased tether formation. Histomorphometry also showed that the hypertrophic zone in Pdia3+/- mice was more cellular than seen in wild type growth plates. Metaphyseal trabecular bone in Pdia3+/- mice exhibited an age-dependent phenotype with lower BV/TV and trabecular numbers, which was most pronounced at 15 weeks of age. Bone marrow cells from Pdia3+/- mice exhibited impaired osteoblastic differentiation, based on reduced expression of osteoblast markers and mineral deposition compared to cells from wild type animals. Collectively, our findings provide in vivo evidence that PDIA3 is essential for normal skeletal development. The fact that the Pdia3+/- heterozygous mice share a similar growth plate and bone phenotype to nVdr knockout mice, suggests that PDIA3-mediated rapid membrane signaling might be an alternative mechanism responsible for 1α,25(OH2D3's actions in regulating skeletal development.

  11. Bicarbonate-sensitive calcification and lifespan of klotho-deficient mice.

    Science.gov (United States)

    Leibrock, Christina B; Voelkl, Jakob; Kohlhofer, Ursula; Quintanilla-Martinez, Leticia; Kuro-O, Makoto; Lang, Florian

    2016-01-01

    Klotho, a protein counteracting aging, is a powerful inhibitor of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] formation and regulator of mineral metabolism. In klotho hypomorphic (kl/kl) mice, excessive 1,25(OH)2D3 formation leads to hypercalcemia, hyperphosphatemia and vascular calcification, severe growth deficits, accelerated aging and early death. Kl/kl mice further suffer from extracellular volume depletion and hypotension, leading to the stimulation of antidiuretic hormone and aldosterone release. A vitamin D-deficient diet, restriction of dietary phosphate, inhibition of mineralocorticoid receptors with spironolactone, and dietary NaCl all extend the lifespan of kl/kl mice. Kl/kl mice suffer from acidosis. The present study explored whether replacement of tap drinking water by 150 mM NaHCO3 affects the growth, tissue calcification, and lifespan of kl/kl mice. As a result, NaHCO3 administration to kl/kl mice did not reverse the growth deficit but substantially decreased tissue calcification and significantly increased the average lifespan from 78 to 127 days. NaHCO3 did not significantly affect plasma concentrations of 1,25(OH)2D3 and Ca(2+) but significantly decreased plasma phosphate concentration and plasma aldosterone concentration. The present study reveals a novel effect of bicarbonate, i.e., a favorable influence on vascular calcification and early death of klotho-deficient mice. Copyright © 2016 the American Physiological Society.

  12. Folate Deficiency Could Restrain Decidual Angiogenesis in Pregnant Mice

    Directory of Open Access Journals (Sweden)

    Yanli Li

    2015-08-01

    Full Text Available The mechanism of birth defects induced by folate deficiency was focused on mainly in fetal development. Little is known about the effect of folate deficiency on the maternal uterus, especially on decidual angiogenesis after implantation which establishes vessel networks to support embryo development. The aim of this study was to investigate the effects of folate deficiency on decidual angiogenesis. Serum folate levels were measured by electrochemiluminescence. The status of decidual angiogenesis was examined by cluster designation 34 (CD34 immunohistochemistry and the expression of angiogenic factors, including vascular endothelial growth factor A (VEGFA, placental growth factor (PLGF, and VEGF receptor 2 (VEGFR2 were also tested. Serum levels of homocysteine (Hcy, follicle stimulating hormone (FSH, luteinizing hormone (LH, prolactin (PRL, progesterone (P4, and estradiol (E2 were detected by Enzyme-linked immunosorbent assay. The folate-deficient mice had a lower folate level and a higher Hcy level. Folate deficiency restrained decidual angiogenesis with significant abnormalities in vascular density and the enlargement and elongation of the vascular sinus. It also showed a reduction in the expressions of VEGFA, VEGFR2, and PLGF. In addition, the serum levels of P4, E2, LH, and PRL were reduced in folate-deficient mice, and the expression of progesterone receptor (PR and estrogen receptor α (ERα were abnormal. These results indicated that folate deficiency could impaire decidual angiogenesis and it may be related to the vasculotoxic properties of Hcy and the imbalance of the reproductive hormone.

  13. Leptin, An Adipokine With Central Importance in the Global Obesity Problem.

    Science.gov (United States)

    Mechanick, Jeffrey I; Zhao, Shan; Garvey, W Timothy

    2017-12-13

    Leptin has central importance in the global obesity and cardiovascular disease problem. Leptin is principally secreted by adipocytes and acts in the hypothalamus to suppress appetite and food intake, increase energy expenditure, and regulate body weight. Based on clinical translation of specific and networked actions, leptin affects the cardiovascular system and may be a marker and driver of cardiometabolic risk factors with interventions that are actionable by cardiologists. Leptin subnetwork analysis demonstrates a statistically significant role for ethnoculturally and socioeconomically appropriate lifestyle intervention in cardiovascular disease. Emergent mechanistic components and potential diagnostic or therapeutic targets include hexokinase 3, urocortins, clusterin, sialic acid-binding immunoglobulin-like lectin 6, C-reactive protein, platelet glycoprotein VI, albumin, pentraxin 3, ghrelin, obestatin prepropeptide, leptin receptor, neuropeptide Y, and corticotropin-releasing factor receptor 1. Emergent associated symptoms include weight change, eating disorders, vascular necrosis, chronic fatigue, and chest pain. Leptin-targeted therapies are reported for lipodystrophy and leptin deficiency, but they are investigational for leptin resistance, obesity, and other chronic diseases. Copyright © 2017 World Heart Federation (Geneva). Published by Elsevier B.V. All rights reserved.

  14. Euglycemia Restoration by Central Leptin in Type 1 Diabetes Requires STAT3 Signaling but Not Fast-Acting Neurotransmitter Release.

    Science.gov (United States)

    Xu, Yuanzhong; Chang, Jeffrey T; Myers, Martin G; Xu, Yong; Tong, Qingchun

    2016-04-01

    Central leptin action is sufficient to restore euglycemia in insulinopenic type 1 diabetes (T1D); however, the underlying mechanism remains poorly understood. To examine the role of intracellular signal transducer and activator of transcription 3 (STAT3) pathways, we used LepRs/s mice with disrupted leptin-phosphorylated STAT3 signaling to test the effect of central leptin on euglycemia restoration. These mice developed streptozocin-induced T1D, which was surprisingly not associated with hyperglucagonemia, a typical manifestation in T1D. Further, leptin action on euglycemia restoration was abrogated in these mice, which was associated with refractory hypercorticosteronemia. To examine the role of fast-acting neurotransmitters glutamate and γ-aminobutyric acid (GABA), two major neurotransmitters in the brain, from leptin receptor (LepR) neurons, we used mice with disrupted release of glutamate, GABA, or both from LepR neurons. Surprisingly, all mice responded normally to leptin-mediated euglycemia restoration, which was associated with expected correction from hyperglucagonemia and hyperphagia. In contrast, mice with loss of glutamate and GABA appeared to develop an additive obesity effect over those with loss of single neurotransmitter release. Thus, our study reveals that STAT3 signaling, but not fast-acting neurotransmitter release, is required for leptin action on euglycemia restoration and that hyperglucagonemia is not required for T1D. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  15. Puberty Is Delayed in Male Mice With Dextran Sodium Sulfate Colitis Out of Proportion to Changes in Food Intake, Body Weight, and Serum Levels of Leptin

    OpenAIRE

    DEBOER, MARK D.; LI, YONGLI

    2011-01-01

    In boys, inflammatory bowel disease often results in delayed puberty associated with decreased bone mineral density and decreased linear growth. Our goal was to investigate whether pubertal timing and levels of leptin differed between prepubertal male mice with colitis and food-restricted (FR) mice maintained at a similar weight. We induced colitis in 32-d-old male mice using dextran sodium sulfate (DSS), resulting in 10 d of worsening colitis. We followed up these mice for separation of the ...

  16. Ipragliflozin Improves Hepatic Steatosis in Obese Mice and Liver Dysfunction in Type 2 Diabetic Patients Irrespective of Body Weight Reduction.

    Directory of Open Access Journals (Sweden)

    Chikara Komiya

    Full Text Available Type 2 diabetes mellitus (T2DM is associated with a high incidence of non-alcoholic fatty liver disease (NAFLD related to obesity and insulin resistance. Currently, medical interventions for NAFLD have focused on diet control and exercise to reduce body weight, and there is a requirement for effective pharmacological therapies. Sodium-glucose cotransporter 2 (SGLT2 inhibitors are oral antidiabetic drugs that promote the urinary excretion of glucose by blocking its reabsorption in renal proximal tubules. SGLT2 inhibitors lower blood glucose independent of insulin action and are expected to reduce body weight because of urinary calorie loss. Here we show that an SGLT2 inhibitor ipragliflozin improves hepatic steatosis in high-fat diet-induced and leptin-deficient (ob/ob obese mice irrespective of body weight reduction. In the obese mice, ipragliflozin-induced hyperphagia occurred to increase energy intake, attenuating body weight reduction with increased epididymal fat mass. There is an inverse correlation between weights of liver and epididymal fat in ipragliflozin-treated obese mice, suggesting that ipragliflozin treatment promotes normotopic fat accumulation in the epididymal fat and prevents ectopic fat accumulation in the liver. Despite increased adiposity, ipragliflozin ameliorates obesity-associated inflammation and insulin resistance in epididymal fat. Clinically, ipragliflozin improves liver dysfunction in patients with T2DM irrespective of body weight reduction. These findings provide new insight into the effects of SGLT2 inhibitors on energy homeostasis and fat accumulation and indicate their potential therapeutic efficacy in T2DM-associated hepatic steatosis.

  17. Essential Role for Hypothalamic Calcitonin Receptor‒Expressing Neurons in the Control of Food Intake by Leptin.

    Science.gov (United States)

    Pan, Warren; Adams, Jessica M; Allison, Margaret B; Patterson, Christa; Flak, Jonathan N; Jones, Justin; Strohbehn, Garth; Trevaskis, James; Rhodes, Christopher J; Olson, David P; Myers, Martin G

    2018-04-01

    The adipocyte-derived hormone leptin acts via its receptor (LepRb) on central nervous system neurons to communicate the repletion of long-term energy stores, to decrease food intake, and to promote energy expenditure. We generated mice that express Cre recombinase from the calcitonin receptor (Calcr) locus (Calcrcre mice) to study Calcr-expressing LepRb (LepRbCalcr) neurons, which reside predominantly in the arcuate nucleus (ARC). Calcrcre-mediated ablation of LepRb in LepRbCalcrknockout (KO) mice caused hyperphagic obesity. Because LepRb-mediated transcriptional control plays a crucial role in leptin action, we used translating ribosome affinity purification followed by RNA sequencing to define the transcriptome of hypothalamic Calcr neurons, along with its alteration in LepRbCalcrKO mice. We found that ARC LepRbCalcr cells include neuropeptide Y (NPY)/agouti-related peptide (AgRP)/γ-aminobutyric acid (GABA) ("NAG") cells as well as non-NAG cells that are distinct from pro-opiomelanocortin cells. Furthermore, although LepRbCalcrKO mice exhibited dysregulated expression of several genes involved in energy balance, neither the expression of Agrp and Npy nor the activity of NAG cells was altered in vivo. Thus, although direct leptin action via LepRbCalcr cells plays an important role in leptin action, our data also suggest that leptin indirectly, as well as directly, regulates these cells.

  18. Adipocyte and leptin accumulation in tumor-induced thymic involution.

    Science.gov (United States)

    Lamas, Alejandro; Lopez, Elena; Carrio, Roberto; Lopez, Diana M

    2016-01-01

    Cell-mediated immunity is an important defense mechanism against pathogens and developing tumor cells. The thymus is the main lymphoid organ involved in the formation of the cell-mediated immune response by the maturation and differentiation of lymphocytes that travel from the bone marrow, through the lymphatic ducts, to become T lymphocytes. Thymic involution has been associated with aging; however, other factors such as obesity, viral infection and tumor development have been shown to increase the rate of shrinkage of this organ. The heavy infiltration of adipocyte fat cells has been reported in the involuted thymuses of aged mice. In the present study, the possible accumulation of such cells in the thymus during tumorigenesis was examined by immunohistochemistry. A significant number of adipocytes around and infiltrating the thymuses of tumor-bearing mice was observed. Leptin is a pro-inflammatory adipocytokine that enhances thymopoiesis and modulates T cell immune responses. The levels of leptin and adiponectin, another adipocytokine that has anti-inflammatory properties, were examined by western blot analysis. While no changes were observed in the amounts of adiponectin present in the thymuses of the normal and tumor-bearing mice, significantly higher levels of leptin were detected in the thymocytes of the tumor-bearing mice. This correlated with an increase in the expression of certain cytokines, such as interleukin (IL)-2, interferon (IFN)-γ and granulocyte-macrophage colony-stimulating factor (GM-CSF). The co-culture of thymocytes isolated from normal mice with ex vivo isolated adipocytes from tumor-bearing mice yielded similar results. Our findings suggest that the infiltration and accumulation of adipocytes in the thymuses of tumor-bearing mice play an important role in their altered morphology and functions.

  19. Immunity to sporozoite-induced malaria infection in mice. I. The effect of immunization of T and B cell-deficient mice

    International Nuclear Information System (INIS)

    Chen, D.H.; Tigelaar, R.E.; Weinbaum, F.I.

    1977-01-01

    The cellular basis of immunity to sporozoites was investigated by examining the effect of immunization of T and B cell-deficient C57BL/6N x BALB/c AnN F 1 (BLCF 1 ) mice compared to immunocompetent controls. Immunization of T cell-deficient (ATX-BM-ATS) BLCF 1 mice with x-irradiated sporozoites did not result in the generation of protective immunity. The same immunization protocols protected all immunocompetent controls. In contrast, B cell-deficient (μ-suppressed) BLCF 1 mice were protected by immunization in the majority of cases. The absence of detectable serum circumsporozoite precipitins or sporozoite neutralizing activity in the μ-suppressed mice that resisted a sporozoite challenge suggests a minor role for these humoral factors in protection. These data demonstrate a preeminent role for T cells in the induction of protective immunity in BLCF 1 mice against a P. berghei sporozoite infection

  20. Melanocortin 1 Receptor Deficiency Promotes Atherosclerosis in Apolipoprotein E-/- Mice.

    Science.gov (United States)

    Rinne, Petteri; Kadiri, James J; Velasco-Delgado, Mauricio; Nuutinen, Salla; Viitala, Miro; Hollmén, Maija; Rami, Martina; Savontaus, Eriika; Steffens, Sabine

    2018-02-01

    The MC1-R (melanocortin 1 receptor) is expressed by monocytes and macrophages where it mediates anti-inflammatory actions. MC1-R also protects against macrophage foam cell formation primarily by promoting cholesterol efflux through the ABCA1 (ATP-binding cassette transporter subfamily A member 1) and ABCG1 (ATP-binding cassette transporter subfamily G member 1). In this study, we aimed to investigate whether global deficiency in MC1-R signaling affects the development of atherosclerosis. Apoe -/- (apolipoprotein E deficient) mice were crossed with recessive yellow (Mc1r e/e ) mice carrying dysfunctional MC1-R and fed a high-fat diet to induce atherosclerosis. Apoe -/- Mc1r e/e mice developed significantly larger atherosclerotic lesions in the aortic sinus and in the whole aorta compared with Apoe -/- controls. In terms of plaque composition, MC1-R deficiency was associated with less collagen and smooth muscle cells and increased necrotic core, indicative of more vulnerable lesions. These changes were accompanied by reduced Abca1 and Abcg1 expression in the aorta. Furthermore, Apoe -/- Mc1r e/e mice showed a defect in bile acid metabolism that aggravated high-fat diet-induced hypercholesterolemia and hepatic lipid accumulation. Flow cytometric analysis of leukocyte profile revealed that dysfunctional MC1-R enhanced arterial accumulation of classical Ly6C high monocytes and macrophages, effects that were evident in mice fed a normal chow diet but not under high-fat diet conditions. In support of enhanced arterial recruitment of Ly6C high monocytes, these cells had increased expression of L-selectin and P-selectin glycoprotein ligand 1. The present study highlights the importance of MC1-R in the development of atherosclerosis. Deficiency in MC1-R signaling exacerbates atherosclerosis by disturbing cholesterol handling and by increasing arterial monocyte accumulation. © 2017 The Authors.

  1. Marginal Biotin Deficiency Is Teratogenic in ICR Mice1,2

    OpenAIRE

    Mock, Donald M.; Mock, Nell I.; Stewart, Christopher W.; LaBorde, James B.; Hansen, Deborah K.

    2003-01-01

    The incidence of marginal biotin deficiency in normal human gestation is approximately one in three. In ICR mice, maternal biotin deficiency results in cleft palate, micrognathia, microglossia and limb hypoplasia. However, the relationships among the severity of maternal biotin deficiency, fetal biotin status and malformations have not been reported. This study utilized validated indices of biotin status to investigate the relationships among maternal biotin status, fetal biotin status and th...

  2. Leptin, soluble leptin receptor, and free leptin index in patients with metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Elena N. Smirnova

    2017-06-01

    Full Text Available Aim. To assess the levels of leptin, its soluble receptor, and index of the formation of free leptin in metabolic syndrome (MS. Materials and methods. The study included 110 individuals with obesity and overweight. The group 1 consisted of 70 patients with MS (IDF, 2005, the average body mass index (BMI 38.4 ± 4.4 kg/m2, aged 48.2 ± 2.4 years, with arterial hypertension (AH 1–2 degree, without regular antihypertensive therapy. Group 2 – "healthy" obesity accounted for 40 patients aged 38.4 ± 6.2 years, BMI 36.0 ± 5.5 kg/m2 without hypertension and metabolic disorders. Group 3 consisted of 30 healthy persons, BMI 27.1 ± 1.3 kg/m2. All patients were evaluated for insulin, HOMA index, leptin, leptin receptor, leptin free index (calculated as the ratio of leptin (ng/ml to the leptin receptor (ng/ml, multiplied by 100. Results: In patients with MS as compared to other two groups there were higher levels of HOMA IR index, leptin and free leptin index. Values of leptin receptor in groups 1 and 2 did not differ significantly and were lower than in healthy persons. The free leptin index was significantly higher in MS group relative to the group 2 and 15 times higher than in the healthy individuals. Free leptin index correlated with values of BMI (R = 0.32; p = 0.02, blood pressure (R = 0.3; p = 0.04, uric acid (R = 0.27; p = 0.04, triglycerides (R = 0.42; p = 0.02, index HOMA-IR (R = 0.45; p = 0.02. Conclusions: Reduction of soluble leptin receptor, depending on the degree of abdominal obesity, may cause progression of leptin resistance in patients with MS. The levels of leptin and soluble leptin receptor appears to have dramatical gender differences. Calculation of free leptin index should be used for the objective evaluation of leptin resistance, regardless of gender, degree of obesity, and other metabolic parameters.

  3. Cystathionine-gamma-lyase deficient mice are protected against the development of multiorgan failure and exhibit reduced inflammatory response during burn.

    Science.gov (United States)

    Ahmad, Akbar; Druzhyna, Nadiya; Szabo, Csaba

    2017-08-01

    Considering the role of H 2 S in critical illness, the aim of this study was to compare the outcome of burn in wild-type mice and in mice deficient in CSE, one of the principal mammalian H 2 S-generating enzymes. Animals were subjected to scald burn. Outcome variables included indices of organ injury, clinical chemistry parameters and plasma levels of inflammatory mediators. Plasma levels of H 2 S significantly increased in response to burn in wild-type mice, but remained unchanged in CSE -/- mice. Expression of the three H 2 S-producing enzymes (CSE, CBS and 3-MST) in the lung and liver, and the capacity of tissue homogenates to produce H 2 S, however, was not affected by burn. In CSE deficient mice there was a significant amelioration of burn-induced accumulation of myeloperoxidase levels in heart, lung, liver and kidney and significantly lower degree of malon dialdehyde accumulation in the heart, lung and kidney than in wild-type mice. CSE deficient mice, compared to wild-type mice, showed a significant attenuation of the burn-induced elevation in circulating alkaline aminotransferase and blood urea nitrogen and creatinine levels, indicative of protective effects of CSE deficiency against burn-induced hepatic, and renal functional impairment. Multiple burn-induced inflammatory mediators (TNF-α, IL-1β, IL-4, IL-6, IL-10 and IL-12) were significantly lower in the plasma of CSE -/- animals after burn than in the plasma of wild-type controls subjected to burns. In conclusion, CSE deficiency improves organ function and attenuates the inflammatory response in a murine model of burn. Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.

  4. Increased susceptibility to diet-induced obesity in GPRC6A receptor knockout mice

    DEFF Research Database (Denmark)

    Clemmensen, Christoffer; Smajilovic, Sanela; Madsen, Andreas N

    2013-01-01

    locomotor activity. Moreover, diet-induced obese Gprc6a KO mice had increased circulating insulin and leptin levels relative to WT animals, thereby demonstrating that endocrine abnormalities associate with the reported disturbances in energy balance. The phenotype was further accompanied by disruptions...... complications is still elusive. In the present study, we investigated the impact of GPRC6A deficiency in a murine model of diet-induced obesity (DIO). Male Gprc6a knockout (KO) mice and WT littermates were subjected to a high-fat diet (HFD) for 25 weeks and exposed to comprehensive metabolic phenotyping...

  5. Transplantation of bone marrow-derived mesenchymal stem cells rescues partially rachitic phenotypes induced by 1,25-Dihydroxyvitamin D deficiency in mice

    OpenAIRE

    Zhang, Zengli; Yin, Shaomeng; Xue, Xian; Ji, Ji; Tong, Jian; Goltzman, David; Miao, Dengshun

    2016-01-01

    To determine whether the transplantation of bone marrow-derived mesenchymal stem cells (BM-MSCs) can improve the 1,25(OH)2D deficiency-induced rachitic phenotype, 2×106 BM-MSCs from wild-type mice or vehicle were transplanted by tail vein injection into mice deficient in 1,25(OH)2D due to targeted deletion of 1α(OH)ase (1α(OH)ase-/-). Our results show that 1α(OH)ase mRNA was expressed in the BM-MSCs derived from wild-type mice, and was detected in long bone, kidney and intestine from BM-MSC-t...

  6. Vaccination against lymphocytic choriomeningitis virus infection in MHC class II-deficient mice

    DEFF Research Database (Denmark)

    Holst, Peter Johannes; Christensen, Jan Pravsgaard; Thomsen, Allan Randrup

    2011-01-01

    response could be elicited in MHC class II-deficient mice by vaccination with adenovirus encoding lymphocytic choriomeningitis virus (LCMV) glycoprotein tethered to MHC class II-associated invariant chain. Moreover, the response induced conferred significant cytolytic CD8(+) T cell-mediated protection...... against challenge with a high dose of the invasive clone 13 strain of LCMV. In contrast, vaccination with adenovirus encoding unlinked LCMV glycoprotein induced weak virus control in the absence of CD4(+) T cells, and mice may die of increased immunopathology associated with incomplete protection. Acute...... mortality was not observed in any vaccinated mice following infection with the less-invasive Traub strain. However, LCMV Traub infection caused accelerated late mortality in unvaccinated MHC class II-deficient mice; in this case, we observed a strong trend toward delayed mortality in vaccinated mice...

  7. Uroguanylin levels in intestine and plasma are regulated by nutritional status in a leptin-dependent manner.

    Science.gov (United States)

    Folgueira, C; Sanchez-Rebordelo, E; Barja-Fernandez, S; Leis, R; Tovar, S; Casanueva, F F; Dieguez, C; Nogueiras, R; Seoane, L M

    2016-03-01

    Uroguanylin (UGN) is a 16 amino acid peptide produced mainly by intestinal epithelial cells. Nutrients intake increases circulating levels of prouroguanylin that is processed and converted to UGN to activate the guanylyl cyclase 2C receptor (GUCY2C). Given that the UGN-GUCY2C system has been proposed as a novel gut-brain endocrine axis regulating energy balance, the aim of the present study was to investigate the regulation of UGN protein levels in duodenum and circulating levels in lean and obese mice under different nutritional conditions and its potential interaction with leptin. Swiss, C57BL/6 wild-type and ob/ob male adult mice under different nutritional conditions were used: fed ad libitum standard diet (control); 48 h fasting (fasted); 48 h fasting followed by 24 h of feeding (refed); and fed high-fat diet (45 %) during 10 weeks. In addition, peripheral leptin administration was performed. Intestinal uroguanylin expression was studied by Western blot analysis; plasma levels were measured by ELISA. Food deprivation significantly reduced plasma UGN levels, which were correlated with the lower protein levels of UGN in duodenum. These effects were reverted after refeeding and leptin challenge. Consistently, in ob/ob mice UGN expression was decreased, whereas leptin treatment up-regulated UGN levels in duodenum in these genetically modified mice compared to WT. Diet-induced obese mice displayed increased UGN levels in intestine and plasma in comparison with lean mice. Our findings suggest that UGN levels are correlated with energy balance status and that the regulation of UGN by nutritional status is leptin-dependent.

  8. Mice deficient in transmembrane prostatic acid phosphatase display increased GABAergic transmission and neurological alterations.

    Directory of Open Access Journals (Sweden)

    Heidi O Nousiainen

    Full Text Available Prostatic acid phosphatase (PAP, the first diagnostic marker and present therapeutic target for prostate cancer, modulates nociception at the dorsal root ganglia (DRG, but its function in the central nervous system has remained unknown. We studied expression and function of TMPAP (the transmembrane isoform of PAP in the brain by utilizing mice deficient in TMPAP (PAP-/- mice. Here we report that TMPAP is expressed in a subpopulation of cerebral GABAergic neurons, and mice deficient in TMPAP show multiple behavioral and neurochemical features linked to hyperdopaminergic dysregulation and altered GABAergic transmission. In addition to increased anxiety, disturbed prepulse inhibition, increased synthesis of striatal dopamine, and augmented response to amphetamine, PAP-deficient mice have enlarged lateral ventricles, reduced diazepam-induced loss of righting reflex, and increased GABAergic tone in the hippocampus. TMPAP in the mouse brain is localized presynaptically, and colocalized with SNARE-associated protein snapin, a protein involved in synaptic vesicle docking and fusion, and PAP-deficient mice display altered subcellular distribution of snapin. We have previously shown TMPAP to reside in prostatic exosomes and we propose that TMPAP is involved in the control of GABAergic tone in the brain also through exocytosis, and that PAP deficiency produces a distinct neurological phenotype.

  9. Modulation of leptin resistance by food compounds.

    Science.gov (United States)

    Aragonès, Gerard; Ardid-Ruiz, Andrea; Ibars, Maria; Suárez, Manuel; Bladé, Cinta

    2016-08-01

    Leptin is mainly secreted by white adipose tissue and regulates energy homeostasis by inhibiting food intake and stimulating energy expenditure through its action in neuronal circuits in the brain, particularly in the hypothalamus. However, hyperleptinemia coexists with the loss of responsiveness to leptin in common obese conditions. This phenomenon has been defined as leptin resistance and the restoration of leptin sensitivity is considered to be a useful strategy to treat obesity. This review summarizes the existing literature on potentially valuable nutrients and food components to reverse leptin resistance. Notably, several food compounds, such as teasaponins, resveratrol, celastrol, caffeine, and taurine among others, are able to restore the leptin signaling in neurons by overexpressing anorexigenic peptides (proopiomelanocortin) and/or repressing orexigenic peptides (neuropeptide Y/agouti-related peptide), thus decreasing food intake. Additionally, some nutrients, such as vitamins A and D, can improve leptin transport through the blood-brain barrier. Therefore, food components can improve leptin resistance by acting at different levels of the leptin pathway; moreover, some compounds are able to target more than one feature of leptin resistance. However, systematic studies are necessary to define the actual effectiveness of each compound. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Role of leptin in female reproduction.

    Science.gov (United States)

    Pérez-Pérez, Antonio; Sánchez-Jiménez, Flora; Maymó, Julieta; Dueñas, José L; Varone, Cecilia; Sánchez-Margalet, Víctor

    2015-01-01

    Reproductive function is dependent on energy resources. The role of weight, body composition, fat distribution and the effect of diet have been largely investigated in experimental female animals as well as in women. Any alteration in diet and/or weight may induce abnormalities in timing of sexual maturation and fertility. However, the cellular mechanisms involved in the fine coordination of energy balance and reproduction are largely unknown. The brain and hypothalamic structures receive endocrine and/or metabolic signals providing information on the nutritional status and the degree of fat stores. Adipose tissue acts both as a store of energy and as an active endocrine organ, secreting a large number of biologically important molecules termed adipokines. Adipokines have been shown to be involved in regulation of the reproductive functions. The first adipokine described was leptin. Extensive research over the last 10 years has shown that leptin is not only an adipose tissue-derived messenger of the amount of energy stores to the brain, but also a crucial hormone/cytokine for a number of diverse physiological processes, such as inflammation, angiogenesis, hematopoiesis, immune function, and most importantly, reproduction. Leptin plays an integral role in the normal physiology of the reproductive system with complex interactions at all levels of the hypothalamic-pituitary gonadal (HPG) axis. In addition, leptin is also produced by placenta, where it plays an important autocrine function. Observational studies have demonstrated that states of leptin excess, deficiency, or resistance can be associated with abnormal reproductive function. This review focuses on the leptin action in female reproduction.

  11. Slitrk1-deficient mice display elevated anxiety-like behavior and noradrenergic abnormalities.

    Science.gov (United States)

    Katayama, K; Yamada, K; Ornthanalai, V G; Inoue, T; Ota, M; Murphy, N P; Aruga, J

    2010-02-01

    Mutations in SLITRK1 are found in patients with Tourette's syndrome and trichotillomania. SLITRK1 encodes a transmembrane protein containing leucine-rich repeats that is produced predominantly in the nervous system. However, the role of this protein is largely unknown, except that it can modulate neurite outgrowth in vitro. To clarify the role of Slitrk1 in vivo, we developed Slitrk1-knockout mice and analyzed their behavioral and neurochemical phenotypes. Slitrk1-deficient mice exhibited elevated anxiety-like behavior in the elevated plus-maze test as well as increased immobility time in forced swimming and tail suspension tests. Neurochemical analysis revealed that Slitrk1-knockout mice had increased levels of norepinephrine and its metabolite 3-methoxy-4-hydroxyphenylglycol. Administration of clonidine, an alpha2-adrenergic agonist that is frequently used to treat patients with Tourette's syndrome, attenuated the anxiety-like behavior of Slitrk1-deficient mice in the elevated plus-maze test. These results lead us to conclude that noradrenergic mechanisms are involved in the behavioral abnormalities of Slitrk1-deficient mice. Elevated anxiety due to Slitrk1 dysfunction may contribute to the pathogenesis of neuropsychiatric diseases such as Tourette's syndrome and trichotillomania.

  12. Vitamin D deficiency in mice impairs colonic antibacterial activity and predisposes to colitis.

    Science.gov (United States)

    Lagishetty, Venu; Misharin, Alexander V; Liu, Nancy Q; Lisse, Thomas S; Chun, Rene F; Ouyang, Yi; McLachlan, Sandra M; Adams, John S; Hewison, Martin

    2010-06-01

    Vitamin D insufficiency is a global health issue. Although classically associated with rickets, low vitamin D levels have also been linked to aberrant immune function and associated health problems such as inflammatory bowel disease (IBD). To test the hypothesis that impaired vitamin D status predisposes to IBD, 8-wk-old C57BL/6 mice were raised from weaning on vitamin D-deficient or vitamin D-sufficient diets and then treated with dextran sodium sulphate (DSS) to induce colitis. Vitamin D-deficient mice showed decreased serum levels of precursor 25-hydroxyvitamin D(3) (2.5 +/- 0.1 vs. 24.4 +/- 1.8 ng/ml) and active 1,25-dihydroxyvitamin D(3) (28.8 +/- 3.1 vs. 45.6 +/- 4.2 pg/ml), greater DSS-induced weight loss (9 vs. 5%), increased colitis (4.71 +/- 0.85 vs. 1.57 +/- 0.18), and splenomegaly relative to mice on vitamin D-sufficient chow. DNA array analysis of colon tissue (n = 4 mice) identified 27 genes consistently (P < 0.05) up-regulated or down-regulated more than 2-fold in vitamin D-deficient vs. vitamin D-sufficient mice, in the absence of DSS-induced colitis. This included angiogenin-4, an antimicrobial protein involved in host containment of enteric bacteria. Immunohistochemistry confirmed that colonic angiogenin-4 protein was significantly decreased in vitamin D-deficient mice even in the absence of colitis. Moreover, the same animals showed elevated levels (50-fold) of bacteria in colonic tissue. These data show for the first time that simple vitamin D deficiency predisposes mice to colitis via dysregulated colonic antimicrobial activity and impaired homeostasis of enteric bacteria. This may be a pivotal mechanism linking vitamin D status with IBD in humans.

  13. Medium-chain triglycerides promote macrophage reverse cholesterol transport and improve atherosclerosis in ApoE-deficient mice fed a high-fat diet.

    Science.gov (United States)

    Zhang, Xinsheng; Zhang, Yong; Liu, Yinghua; Wang, Jin; Xu, Qing; Yu, Xiaoming; Yang, Xueyan; Liu, Zhao; Xue, Changyong

    2016-09-01

    We previously observed that medium-chain triglycerides (MCTs) could reduce body fat mass and improve the metabolism of cholesterol. We hypothesized that MCTs can improve atherosclerosis by promoting the reverse cholesterol transport (RCT) process. Therefore, the objective of this study was to investigate the roles of MCTs in macrophage RCT and the progression of atherosclerosis. To test this hypothesis, 30 4-week-old ApoE-deficient (ApoE(-/-)) mice were randomly divided into 2 groups and fed a diet of 2% MCTs or long-chain triglycerides (LCTs) for 16 weeks. Ten age- and sex-matched C57BL/6J mice were fed a diet of 2% LCTs as the control. Macrophage-to-feces RCT was assessed in vivo by intraperitoneal injection of RAW 264.7 macrophages containing (3)H-labeled cholesterol, and atherosclerotic plaques were measured. The mRNA and protein expressions were determined by reverse transcriptase polymerase chain reaction and Western blot analyses, respectively. There was a greater decrease in body fat mass, atherosclerotic plaques, and an improvement in serum lipid profiles. In addition, the MCT mice group showed an increase in (3)H-tracer in the feces and a decrease in the liver. Significantly higher levels of mRNA and protein expression of hepatic ATP-binding cassette transporter A1, ATP-binding cassette transporter G5, cholesterol 7α-hydroxylase, and intestinal ATP-binding cassette transporter G8, as well as lower levels of expression of intestinal Niemann-Pick C1-like 1, were found in the MCT group. These results suggest that MCTs could obviously promote macrophage RCT and improve atherosclerosis in ApoE(-/-) mice, indicating that MCTs have the potential to prevent cardiovascular disease. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Bortezomib partially improves laminin α2 chain-deficient muscular dystrophy.

    Science.gov (United States)

    Körner, Zandra; Fontes-Oliveira, Cibely C; Holmberg, Johan; Carmignac, Virginie; Durbeej, Madeleine

    2014-05-01

    Congenital muscular dystrophy, caused by mutations in LAMA2 (the gene encoding laminin α2 chain), is a severe and incapacitating disease for which no therapy is yet available. We have recently demonstrated that proteasome activity is increased in laminin α2 chain-deficient muscle and that treatment with the nonpharmaceutical proteasome inhibitor MG-132 reduces muscle pathology in laminin α2 chain-deficient dy(3K)/dy(3K) mice. Here, we explore the use of the selective and therapeutic proteasome inhibitor bortezomib (currently used for treatment of relapsed multiple myeloma and mantle cell lymphoma) in dy(3K)/dy(3K) mice and in congenital muscular dystrophy type 1A muscle cells. Outcome measures included quantitative muscle morphology, gene and miRNA expression analyses, proteasome activity, motor activity, and survival. Bortezomib improved several histological hallmarks of disease, partially normalized miRNA expression (miR-1 and miR-133a), and enhanced body weight, locomotion, and survival of dy(3K)/dy(3K) mice. In addition, bortezomib reduced proteasome activity in congenital muscular dystrophy type 1A myoblasts and myotubes. These findings provide evidence that the proteasome inhibitor bortezomib partially reduces laminin α2 chain-deficient muscular dystrophy. Investigation of the clinical efficacy of bortezomib administration in congenital muscular dystrophy type 1A clinical trials may be warranted. Copyright © 2014 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  15. Comprehensive Behavioral Analysis of Activating Transcription Factor 5-Deficient Mice

    Directory of Open Access Journals (Sweden)

    Mariko Umemura

    2017-07-01

    Full Text Available Activating transcription factor 5 (ATF5 is a member of the CREB/ATF family of basic leucine zipper transcription factors. We previously reported that ATF5-deficient (ATF5-/- mice demonstrated abnormal olfactory bulb development due to impaired interneuron supply. Furthermore, ATF5-/- mice were less aggressive than ATF5+/+ mice. Although ATF5 is widely expressed in the brain, and involved in the regulation of proliferation and development of neurons, the physiological role of ATF5 in the higher brain remains unknown. Our objective was to investigate the physiological role of ATF5 in the higher brain. We performed a comprehensive behavioral analysis using ATF5-/- mice and wild type littermates. ATF5-/- mice exhibited abnormal locomotor activity in the open field test. They also exhibited abnormal anxiety-like behavior in the light/dark transition test and open field test. Furthermore, ATF5-/- mice displayed reduced social interaction in the Crawley’s social interaction test and increased pain sensitivity in the hot plate test compared with wild type. Finally, behavioral flexibility was reduced in the T-maze test in ATF5-/- mice compared with wild type. In addition, we demonstrated that ATF5-/- mice display disturbances of monoamine neurotransmitter levels in several brain regions. These results indicate that ATF5 deficiency elicits abnormal behaviors and the disturbance of monoamine neurotransmitter levels in the brain. The behavioral abnormalities of ATF5-/- mice may be due to the disturbance of monoamine levels. Taken together, these findings suggest that ATF5-/- mice may be a unique animal model of some psychiatric disorders.

  16. Macrophage JAK2 deficiency protects against high-fat diet-induced inflammation.

    Science.gov (United States)

    Desai, Harsh R; Sivasubramaniyam, Tharini; Revelo, Xavier S; Schroer, Stephanie A; Luk, Cynthia T; Rikkala, Prashanth R; Metherel, Adam H; Dodington, David W; Park, Yoo Jin; Kim, Min Jeong; Rapps, Joshua A; Besla, Rickvinder; Robbins, Clinton S; Wagner, Kay-Uwe; Bazinet, Richard P; Winer, Daniel A; Woo, Minna

    2017-08-09

    During obesity, macrophages can infiltrate metabolic tissues, and contribute to chronic low-grade inflammation, and mediate insulin resistance and diabetes. Recent studies have elucidated the metabolic role of JAK2, a key mediator downstream of various cytokines and growth factors. Our study addresses the essential role of macrophage JAK2 in the pathogenesis to obesity-associated inflammation and insulin resistance. During high-fat diet (HFD) feeding, macrophage-specific JAK2 knockout (M-JAK2 -/- ) mice gained less body weight compared to wildtype littermate control (M-JAK2 +/+ ) mice and were protected from HFD-induced systemic insulin resistance. Histological analysis revealed smaller adipocytes and qPCR analysis showed upregulated expression of some adipogenesis markers in visceral adipose tissue (VAT) of HFD-fed M-JAK2 -/- mice. There were decreased crown-like structures in VAT along with reduced mRNA expression of some macrophage markers and chemokines in liver and VAT of HFD-fed M-JAK2 -/- mice. Peritoneal macrophages from M-JAK2 -/- mice and Jak2 knockdown in macrophage cell line RAW 264.7 also showed lower levels of chemokine expression and reduced phosphorylated STAT3. However, leptin-dependent effects on augmenting chemokine expression in RAW 264.7 cells did not require JAK2. Collectively, our findings show that macrophage JAK2 deficiency improves systemic insulin sensitivity and reduces inflammation in VAT and liver in response to metabolic stress.

  17. DRP1 Suppresses Leptin and Glucose Sensing of POMC Neurons.

    Science.gov (United States)

    Santoro, Anna; Campolo, Michela; Liu, Chen; Sesaki, Hiromi; Meli, Rosaria; Liu, Zhong-Wu; Kim, Jung Dae; Diano, Sabrina

    2017-03-07

    Hypothalamic pro-opiomelanocortin (POMC) neurons regulate energy and glucose metabolism. Intracellular mechanisms that enable these neurons to respond to changes in metabolic environment are ill defined. Here we show reduced expression of activated dynamin-related protein (pDRP1), a mitochondrial fission regulator, in POMC neurons of fed mice. These POMC neurons displayed increased mitochondrial size and aspect ratio compared to POMC neurons of fasted animals. Inducible deletion of DRP1 of mature POMC neurons (Drp1 fl/fl -POMC-cre:ER T2 ) resulted in improved leptin sensitivity and glucose responsiveness. In Drp1 fl/fl -POMC-cre:ER T2 mice, POMC neurons showed increased mitochondrial size, ROS production, and neuronal activation with increased expression of Kcnj11 mRNA regulated by peroxisome proliferator-activated receptor (PPAR). Furthermore, deletion of DRP1 enhanced the glucoprivic stimulus in these neurons, causing their stronger inhibition and a greater activation of counter-regulatory responses to hypoglycemia that were PPAR dependent. Together, these data unmasked a role for mitochondrial fission in leptin sensitivity and glucose sensing of POMC neurons. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Spontaneous chondroma formation in CD2-Cre-driven Erk-deficient mice.

    Science.gov (United States)

    Shiokawa, Moe; Lu, Xiuyuan; Miyake, Yasunobu; Ishikawa, Eri; Pagès, Gilles; Pouysségur, Jacques; Ogata, Masato; Yamasaki, Sho

    2017-12-18

    Lineage-specific Cre Tg mice are widely used to delineate the functions of genes in a tissue-specific manner. Several T-cell-specific promoter cassettes have been developed; however, the activities of those promoters in non-T cells have not been investigated extensively. Here, we report that CD2-Cre-mediated deletion of Erk proteins by generating CD2-Cre × Erk1-/-Erk2flox/flox (Erk∆CD2-Cre) mice results in abnormal cartilage hyperplasia. Histological analysis revealed that this abnormality is caused by aberrant hyperplasia of chondrocytes. The presence of Erk-deficient T cells is not required for this chondroma formation, as it was similarly observed in the absence of T cells in a CD3ε-deficient background. In addition, adoptive transfer of bone marrow cells from Erk∆CD2-Cre mice to wild-type recipients did not cause chondroma formation, suggesting that Erk-deficient non-immune cells are responsible for this abnormality. By tracing Cre-expressed tissues using a ROSA26-STOP-RFP allele, we found that the chondroma emitted RFP fluorescence, indicating that functional Cre is expressed in hyperplastic chondrocytes in Erk∆CD2-Cre mice. Furthermore, RFP+ chondrocytes were also found in an Erk-sufficient background, albeit without aberrant growth. These results suggest that unexpected expression of CD2-driven Cre in chondrocytes generates Erk-deficient chondrocytes, resulting in hyperplastic cartilage formation. Recently, two independent reports showed that CD4-Cre-mediated Ras-Erk signaling ablation led to similar abnormal cartilage formation (Guittard, G., Gallardo, D. L., Li, W. et al. 2017. Unexpected cartilage phenotype in CD4-Cre-conditional SOS-deficient mice. Front. Immunol. 8:343; Wehenkel, M., Corr, M., Guy, C. S. et al. 2017. Extracellular signal-regulated kinase signaling in CD4-expressing cells inhibits osteochondromas. Front. Immunol. 8:482). Together with these reports, our study suggests that an unexpected link exists between T-like cell and

  19. Inducing maternal inflammation promotes leptin production in offspring but does not improve allergic symptoms in a mouse model of allergic rhinitis

    Directory of Open Access Journals (Sweden)

    Atsuko Imai

    2017-06-01

    Full Text Available Aims: The intrauterine environment is considered to affect immunological development in fetus, leading to an increased risk of developing allergy. In particular, maternal lipopolysaccharides (LPS administration might regulate the development of allergic disease in offspring. Several studies have shown that being obese relates to a higher prevalence of allergic diseases compared to normal weight. The present study explored the effects of inducing maternal inflammation with LPS before pregnancy on body weight, physical composition including body fat, adipokine production, and pathology of allergic rhinitis in offspring. Main methods: Female mice received a single intraperitoneal injection of LPS (2 μg/g BW. After 5 days of LPS administration, female mice were mated with males, and experimental allergic rhinitis was induced in female offspring. Immunization and nasal challenge with ovalbumin (OVA were performed at 7 and 8 weeks of age. Allergic rhinitis-like symptoms, OVA-specific IgE and adipokines in sera, body weight, fat pad weight, and cytokine production by splenocytes in these 9-week-old offspring. Key findings: Maternal LPS administration results in a significant increase in body weight, visceral fat accumulation, and serum leptin concentration, and the dominance of Th1 in Th balance. Nevertheless, there was no statistical difference in OVA-specific IgE titer and allergic-like symptoms between the groups. Significance: In conclusion, maternal LPS promoted leptin production and altered Th balance in mice offspring, but not improved allergic symptoms in a mouse model of allergic rhinitis. It might suggest that inflammation during pregnancy plays a role in the adipose tissue function which could diversely influence allergic inflammation in offspring. Keywords: Immunology, Metabolism, Nutrition, Health Sciences

  20. Cell type-specific deficiency of c-kit gene expression in mutant mice of mi/mi genotype.

    Science.gov (United States)

    Isozaki, K.; Tsujimura, T.; Nomura, S.; Morii, E.; Koshimizu, U.; Nishimune, Y.; Kitamura, Y.

    1994-01-01

    The mi locus of mice encodes a novel member of the basic-helix-loop-helix-leucine zipper protein family of transcription factors (hereafter called mi factor). In addition to microphthalmus, osteopetrosis, and lack of melanocytes, mice of mi/mi genotype are deficient in mast cells. Since the c-kit receptor tyrosine kinase plays an important role in the development of mast cells, and since the c-kit expression by cultured mast cells from mi/mi mice is deficient in both mRNA and protein levels, the mast cell deficiency of mi/mi mice has been attributed at least in part to the deficient expression of c-kit. However, it remained to be examined whether the c-kit expression was also deficient in tissues of mi/mi mice. In the present study, we examined the c-kit expression by mi/mi skin mast cells using in situ hybridization and immunohistochemistry. Moreover, we examined the c-kit expression by various cells other than mast cells in tissues of mi/mi mice. We found that the c-kit expression was deficient in mast cells but not in erythroid precursors, testicular germ cells, and neurons of mi/mi mice. This suggested that the regulation of the c-kit transcription by the mi factor was dependent on cell types. Mice of mi/mi genotype appeared to be a useful model to analyze the function of transcription factors in the whole-animal level. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:7524330

  1. Correction of lysosomal enzyme deficiency in various organs of beta-glucuronidase-deficient mice by allogeneic bone marrow transplantation

    NARCIS (Netherlands)

    Hoogerbrugge, P. M.; Poorthuis, B. J.; Mulder, A. H.; Wagemaker, G.; Dooren, L. J.; Vossen, J. M.; van Bekkum, D. W.

    1987-01-01

    The correction of lysosomal enzyme deficiency was investigated for various organs of beta-glucuronidase-deficient C3H/Rij mice after allogeneic bone marrow transplantation from an enzymatically normal donor strain (C57BL/Rij). In the hemopoietic organs, the enzyme level increased to levels found in

  2. Defective bone repair in mast cell-deficient Cpa3Cre/+ mice.

    Directory of Open Access Journals (Sweden)

    Jose Luis Ramirez-GarciaLuna

    Full Text Available In the adult skeleton, cells of the immune system interact with those of the skeleton during all phases of bone repair to influence the outcome. Mast cells are immune cells best known for their pathologic role in allergy, and may be involved in chronic inflammatory and fibrotic disorders. Potential roles for mast cells in tissue homeostasis, vascularization and repair remain enigmatic. Previous studies in combined mast cell- and Kit-deficient KitW-sh/W-sh mice (KitW-sh implicated mast cells in bone repair but KitW-sh mice suffer from additional Kit-dependent hematopoietic and non- hematopoietic deficiencies that could have confounded the outcome. The goal of the current study was to compare bone repair in normal wild type (WT and Cpa3Cre/+ mice, which lack mast cells in the absence of any other hematopoietic or non- hematopoietic deficiencies. Repair of a femoral window defect was characterized using micro CT imaging and histological analyses from the early inflammatory phase, through soft and hard callus formation, and finally the remodeling phase. The data indicate 1 mast cells appear in healing bone of WT mice but not Cpa3Cre/+ mice, beginning 14 days after surgery; 2 re-vascularization of repair tissue and deposition of mineralized bone was delayed and dis-organised in Cpa3Cre/+ mice compared with WT mice; 3 the defects in Cpa3Cre/+ mice were associated with little change in anabolic activity and biphasic alterations in osteoclast and macrophage activity. The outcome at 56 days postoperative was complete bridging of the defect in most WT mice and fibrous mal-union in most Cpa3Cre/+ mice. The results indicate that mast cells promote bone healing, possibly by recruiting vascular endothelial cells during the inflammatory phase and coordinating anabolic and catabolic activity during tissue remodeling. Taken together the data indicate that mast cells have a positive impact on bone repair.

  3. Defective bone repair in mast cell-deficient Cpa3Cre/+ mice.

    Science.gov (United States)

    Ramirez-GarciaLuna, Jose Luis; Chan, Daniel; Samberg, Robert; Abou-Rjeili, Mira; Wong, Timothy H; Li, Ailian; Feyerabend, Thorsten B; Rodewald, Hans-Reimer; Henderson, Janet E; Martineau, Paul A

    2017-01-01

    In the adult skeleton, cells of the immune system interact with those of the skeleton during all phases of bone repair to influence the outcome. Mast cells are immune cells best known for their pathologic role in allergy, and may be involved in chronic inflammatory and fibrotic disorders. Potential roles for mast cells in tissue homeostasis, vascularization and repair remain enigmatic. Previous studies in combined mast cell- and Kit-deficient KitW-sh/W-sh mice (KitW-sh) implicated mast cells in bone repair but KitW-sh mice suffer from additional Kit-dependent hematopoietic and non- hematopoietic deficiencies that could have confounded the outcome. The goal of the current study was to compare bone repair in normal wild type (WT) and Cpa3Cre/+ mice, which lack mast cells in the absence of any other hematopoietic or non- hematopoietic deficiencies. Repair of a femoral window defect was characterized using micro CT imaging and histological analyses from the early inflammatory phase, through soft and hard callus formation, and finally the remodeling phase. The data indicate 1) mast cells appear in healing bone of WT mice but not Cpa3Cre/+ mice, beginning 14 days after surgery; 2) re-vascularization of repair tissue and deposition of mineralized bone was delayed and dis-organised in Cpa3Cre/+ mice compared with WT mice; 3) the defects in Cpa3Cre/+ mice were associated with little change in anabolic activity and biphasic alterations in osteoclast and macrophage activity. The outcome at 56 days postoperative was complete bridging of the defect in most WT mice and fibrous mal-union in most Cpa3Cre/+ mice. The results indicate that mast cells promote bone healing, possibly by recruiting vascular endothelial cells during the inflammatory phase and coordinating anabolic and catabolic activity during tissue remodeling. Taken together the data indicate that mast cells have a positive impact on bone repair.

  4. [Effect of extracts from Dendrobii ifficinalis flos on hyperthyroidism Yin deficiency mice].

    Science.gov (United States)

    Lei, Shan-shan; Lv, Gui-yuan; Jin, Ze-wu; Li, Bo; Yang, Zheng-biao; Chen, Su-hong

    2015-05-01

    Some unhealthy life habits, such as long-term smoking, heavy drinking, sexual overstrain and frequent stay-up could induce the Yin deficiency symptoms of zygomatic red and dysphoria. Stems of Dendrobii officinalis flos (DOF) showed the efficacy of nourishing Yin. In this study, the hyperthyroidism Yin deficiency model was set up to study the yin nourishing effect and action mechanism of DOF, in order to provide the pharmacological basis for developing DOF resources and decreasing resource wastes. ICR mice were divided into five groups: the normal control group, the model control group, the positive control group and DOF extract groups (6.4 g · kg(-1)). Except for the normal group, the other groups were administrated with thyroxine for 30 d to set up the hyperthyroidism yin deficiency model. At the same time, the other groups were administrated with the corresponding drugs for 30 d. After administration for 4 weeks, the signs (facial temperature, pain domain, heart rate and autonomic activity) in mice were measured, and the facial and ear micro-circulation blood flow were detected by laser Doppler technology. After the last administration, all mice were fasted for 12 hours, blood were collected from their orbits, and serum were separated to detect AST, ALT, TG and TP by the automatic biochemistry analyzer and test T3, T4 and TSH levels by ELISA. (1) Compared with the normal control group, the model control group showed significant increases in facial and ear micro-circulation blood flow, facial temperature and heart rate (P effects by impacting thyroxin substance metabolism, improving micro-circulation and reducing heart rate.

  5. Cardiovascular phenotype in Smad3 deficient mice with renovascular hypertension.

    Science.gov (United States)

    Kashyap, Sonu; Warner, Gina; Hu, Zeng; Gao, Feng; Osman, Mazen; Al Saiegh, Yousif; Lien, Karen R; Nath, Karl; Grande, Joseph P

    2017-01-01

    Renovascular hypertension (RVH) has deleterious effects on both the kidney and the heart. TGF-β signaling through Smad3 directs tissue fibrosis in chronic injury models. In the 2-kidney 1-clip (2K1C) model of RVH, employing mice on the 129 genetic background, Smad3 deficiency (KO) protects the stenotic kidney (STK) from development of interstitial fibrosis. However, these mice have an increased incidence of sudden cardiac death following 2K1C surgery. The purpose of this study was to characterize the cardiovascular phenotype of these mice. Renal artery stenosis (RAS) was established in Wild-type (WT) and Smad3 KO mice (129 genetic background) by placement of a polytetrafluoroethylene cuff on the right renal artery. Mortality was 25.5% for KO mice with RAS, 4.1% for KO sham mice, 1.2% for WT with RAS, and 1.8% for WT sham mice. Myocardial tissue of mice studied at 3 days following surgery showed extensive myocyte necrosis in KO but not WT mice. Myocyte necrosis was associated with a rapid induction of Ccl2 expression, macrophage influx, and increased MMP-9 activity. At later time points, both KO and WT mice developed myocardial fibrosis. No aortic aneurysms or dissections were observed at any time point. Smad3 KO mice were backcrossed to the C57BL/6J strain and subjected to RAS. Sudden death was observed at 10-14 days following surgery in 62.5% of mice; necropsy revealed aortic dissections as the cause of death. As observed in the 129 mice, the STK of Smad3 KO mice on the C57BL/6J background did not develop significant chronic renal damage. We conclude that the cardiovascular manifestations of Smad3 deficient mice are strain-specific, with myocyte necrosis in 129 mice and aortic rupture in C57BL/6J mice. Future studies will define mechanisms underlying this strain-specific effect on the cardiovascular system.

  6. Cardiovascular phenotype in Smad3 deficient mice with renovascular hypertension.

    Directory of Open Access Journals (Sweden)

    Sonu Kashyap

    Full Text Available Renovascular hypertension (RVH has deleterious effects on both the kidney and the heart. TGF-β signaling through Smad3 directs tissue fibrosis in chronic injury models. In the 2-kidney 1-clip (2K1C model of RVH, employing mice on the 129 genetic background, Smad3 deficiency (KO protects the stenotic kidney (STK from development of interstitial fibrosis. However, these mice have an increased incidence of sudden cardiac death following 2K1C surgery. The purpose of this study was to characterize the cardiovascular phenotype of these mice. Renal artery stenosis (RAS was established in Wild-type (WT and Smad3 KO mice (129 genetic background by placement of a polytetrafluoroethylene cuff on the right renal artery. Mortality was 25.5% for KO mice with RAS, 4.1% for KO sham mice, 1.2% for WT with RAS, and 1.8% for WT sham mice. Myocardial tissue of mice studied at 3 days following surgery showed extensive myocyte necrosis in KO but not WT mice. Myocyte necrosis was associated with a rapid induction of Ccl2 expression, macrophage influx, and increased MMP-9 activity. At later time points, both KO and WT mice developed myocardial fibrosis. No aortic aneurysms or dissections were observed at any time point. Smad3 KO mice were backcrossed to the C57BL/6J strain and subjected to RAS. Sudden death was observed at 10-14 days following surgery in 62.5% of mice; necropsy revealed aortic dissections as the cause of death. As observed in the 129 mice, the STK of Smad3 KO mice on the C57BL/6J background did not develop significant chronic renal damage. We conclude that the cardiovascular manifestations of Smad3 deficient mice are strain-specific, with myocyte necrosis in 129 mice and aortic rupture in C57BL/6J mice. Future studies will define mechanisms underlying this strain-specific effect on the cardiovascular system.

  7. Leptin, NPY, Melatonin and Zinc Levels in Experimental Hypothyroidism and Hyperthyroidism: The Relation to Zinc.

    Science.gov (United States)

    Baltaci, Abdulkerim Kasım; Mogulkoc, Rasim

    2017-06-01

    Since zinc mediates the effects of many hormones or is found in the structure of numerous hormone receptors, zinc deficiency leads to various functional impairments in the hormone balance. And also thyroid hormones have important activity on metabolism and feeding. NPY and leptin are affective on food intake and regulation of appetite. The present study is conducted to determine how zinc supplementation and deficiency affect thyroid hormones (free and total T3 and T4), melatonin, leptin, and NPY levels in thyroid dysfunction in rats. The experiment groups in the study were formed as follows: Control (C); Hypothyroidism (PTU); Hypothyroidism+Zinc (PTU+Zn); Hypothyroidism+Zinc deficient; Hyperthyroidism (H); Hyperthyroidism+Zinc (H+Zn); and Hyperthyroidism+Zinc deficient. Thyroid hormone parameters (FT 3 , FT 4 , TT 3 , and TT 4 ) were found to be reduced in hypothyroidism groups and elevated in the hyperthyroidism groups. Melatonin values increased in hyperthyroidism and decreased in hypothyroidism. Leptin and NPY levels both increased in hypo- and hyperthyroidism. Zinc levels, on the other hand, decreased in hypothyroidism and increased in hyperthyroidism. Zinc supplementation, particularly when thyroid function is impaired, has been demonstrated to markedly prevent these changes.

  8. Primer for non-immunologists on immune-deficient mice and their applications in research.

    Science.gov (United States)

    Croy, B A; Linder, K E; Yager, J A

    2001-08-01

    Studies of immune deficiencies have a history as long as that of immunology. However, reports of two key spontaneous recessive mutations in mice (nude in 1966-1968 and scid in 1983) laid the foundations for widespread application of immune-deficient rodents to a broad range of research topics. More recently, technologies modifying the mouse genome by transgenesis, gene ablation and crossbreeding for lines with multiple immune deficits have provided a large number of new types of immunologically impaired mice. The primary goals of this overview are to help non-immunologists understand key differences between some of the immunodeficient strains, develop an appreciation for the value of information derived from immunodeficient mouse-based research and to encourage expanded, creative use of these specialized research animals. Secondary goals are to promote greater awareness of unexpected outcomes that can arise when working with genetically immune-deficient mice, the need for vigilance in maintaining these research animals, and the care required in interpretation of the data that immune-deficient modeling provides. Two illustrations on developing appropriate immune deficient animal models for a new research application conclude the review.

  9. Relative Tissue Factor Deficiency Attenuates Ventilator-Induced Coagulopathy but Does Not Protect against Ventilator-Induced Lung Injury in Mice

    Directory of Open Access Journals (Sweden)

    Esther K. Wolthuis

    2012-01-01

    Full Text Available Preventing tissue-factor-(TF- mediated systemic coagulopathy improves outcome in models of sepsis. Preventing TF-mediated pulmonary coagulopathy could attenuate ventilator-induced lung injury (VILI. We investigated the effect of relative TF deficiency on pulmonary coagulopathy and inflammation in a murine model of VILI. Heterozygous TF knockout (TF+/− mice and their wild-type (TF+/+ littermates were sedated (controls or sedated, tracheotomized, and mechanically ventilated with either low or high tidal volumes for 5 hours. Mechanical ventilation resulted in pulmonary coagulopathy and inflammation, with more injury after mechanical ventilation with higher tidal volumes. Compared with TF+/+ mice, TF+/− mice demonstrated significantly lower pulmonary thrombin-antithrombin complex levels in both ventilation groups. There were, however, no differences in lung wet-to-dry ratio, BALF total protein levels, neutrophil influx, and lung histopathology scores between TF+/− and TF+/+ mice. Notably, pulmonary levels of cytokines were significantly higher in TF+/− as compared to TF+/+ mice. Systemic levels of cytokines were not altered by the relative absence of TF. TF deficiency is associated with decreased pulmonary coagulation independent of the ventilation strategy. However, relative TF deficiency does not reduce VILI and actually results in higher pulmonary levels of inflammatory mediators.

  10. Regulation of Blood Pressure, Appetite, and Glucose by Leptin After Inactivation of Insulin Receptor Substrate 2 Signaling in the Entire Brain or in Proopiomelanocortin Neurons.

    Science.gov (United States)

    do Carmo, Jussara M; da Silva, Alexandre A; Wang, Zhen; Freeman, Nathan J; Alsheik, Ammar J; Adi, Ahmad; Hall, John E

    2016-02-01

    Insulin receptor substrate 2 (IRS2) is one of the 3 major leptin receptor signaling pathways, but its role in mediating the chronic effects of leptin on blood pressure, food intake, and glucose regulation is unclear. We tested whether genetic inactivation of IRS2 in the entire brain (IRS2/Nestin-cre mice) or specifically in proopiomelanocortin (POMC) neurons (IRS2/POMC-cre mice) attenuates the chronic cardiovascular, metabolic, and antidiabetic effects of leptin. Mice were instrumented with telemetry probes for measurement of blood pressure and heart rate and with venous catheters for intravenous infusions. After a 5-day control period, mice received leptin infusion (2 μg/kg per minute) for 7 days. Compared with control IRS2(flox/flox) mice, IRS2/POMC-cre mice had similar body weight and food intake (33±1 versus 35±1 g and 3.6±0.5 versus 3.8±0.2 g per day) but higher mean arterial pressure (MAP) and heart rate (110±2 versus 102±2 mm Hg and 641±9 versus 616±5 bpm). IRS2/Nestin-cre mice were heavier (38±2 g), slightly hyperphagic (4.5±1.0 g per day), and had higher MAP and heart rate (108±2 mm Hg and 659±9 bpm) compared with control mice. Leptin infusion gradually increased MAP despite decreasing food intake by 31% in IRS2(flox/flox) and in Nestin-cre control mice. In contrast, leptin infusion did not change MAP in IRS2/Nestin-cre or IRS2/POMC-cre mice. The anorexic and antidiabetic effects of leptin, however, were similar in all 3 groups. These results indicate that IRS2 signaling in the central nervous system, and particularly in POMC neurons, is essential for the chronic actions of leptin to raise MAP but not for its anorexic or antidiabetic effects. © 2015 American Heart Association, Inc.

  11. Ultrastructural analysis of development of myocardium in calreticulin-deficient mice

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    Michalak Marek

    2006-11-01

    Full Text Available Abstract Background Calreticulin is a Ca2+ binding chaperone of the endoplasmic reticulum which influences gene expression and cell adhesion. The levels of both vinculin and N-cadherin are induced by calreticulin expression, which play important roles in cell adhesiveness. Cardiac development is strictly dependent upon the ability of cells to adhere to their substratum and to communicate with their neighbours. Results We show here that the levels of N-cadherin are downregulated in calreticulin-deficient mouse embryonic hearts, which may lead to the disarray and wavy appearance of myofibrils in these mice, which we detected at all investigated stages of cardiac development. Calreticulin wild type mice exhibited straight, thick and abundant myofibrils, which were in stark contrast to the thin, less numerous, disorganized myofibrils of the calreticulin-deficient hearts. Interestingly, these major differences were only detected in the developing ventricles while the atria of both calreticulin phenotypes were similar in appearance at all developmental stages. Glycogen also accumulated in the ventricles of calreticulin-deficient mice, indicating an abnormality in cardiomyocyte metabolism. Conclusion Calreticulin is temporarily expressed during heart development where it is required for proper myofibrillogenesis. We postulate that calreticulin be considered as a novel cardiac fetal gene.

  12. Clearance of Giardia muris infection in mice deficient in natural killer cells.

    OpenAIRE

    Heyworth, M F; Kung, J E; Eriksson, E C

    1986-01-01

    Immunocompetent C57BL/6J mice and beige mice (which are deficient in natural killer cells) were infected with Giardia muris. Both types of mice cleared G. muris infection at similar rates. This observation suggests that clearance of G. muris parasites from the mouse intestine is not mediated by natural killer cells.

  13. Inducible arginase 1 deficiency in mice leads to hyperargininemia and altered amino acid metabolism.

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    Yuan Yan Sin

    Full Text Available Arginase deficiency is a rare autosomal recessive disorder resulting from a loss of the liver arginase isoform, arginase 1 (ARG1, which is the final step in the urea cycle for detoxifying ammonia. ARG1 deficiency leads to hyperargininemia, characterized by progressive neurological impairment, persistent growth retardation and infrequent episodes of hyperammonemia. Using the Cre/loxP-directed conditional gene knockout system, we generated an inducible Arg1-deficient mouse model by crossing "floxed" Arg1 mice with CreER(T2 mice. The resulting mice (Arg-Cre die about two weeks after tamoxifen administration regardless of the starting age of inducing the knockout. These treated mice were nearly devoid of Arg1 mRNA, protein and liver arginase activity, and exhibited symptoms of hyperammonemia. Plasma amino acid analysis revealed pronounced hyperargininemia and significant alterations in amino acid and guanidino compound metabolism, including increased citrulline and guanidinoacetic acid. Despite no alteration in ornithine levels, concentrations of other amino acids such as proline and the branched-chain amino acids were reduced. In summary, we have generated and characterized an inducible Arg1-deficient mouse model exhibiting several pathologic manifestations of hyperargininemia. This model should prove useful for exploring potential treatment options of ARG1 deficiency.

  14. [Leptin: aspects on energetic balance, physical exercise and athletic amenorhea].

    Science.gov (United States)

    Ribeiro, Sandra Maria Lima; dos Santos, Zirlene Adriana; da Silva, Renata Juliana; Louzada, Eliana; Donato, José; Tirapegui, Julio

    2007-02-01

    The aim of this manuscript was to review the knowledge about leptin, detailing its relationship with energetic intake and physical activity. Leptin is an adipocyte hormone, recognized mainly for its putative role in control of energy expenditure, food intake, body weight and reproductive function. Leptin has still important peripheral actions, including its role on the ovarian tissue. The intracellular signaling mechanisms are recognized in hypothalamus, but in peripheral tissue are not fully understood. The exercise, when practiced by women, if not appropriately planned according to food intake, can modify the leptin release. When energy imbalances induced by exercise and/or deficient food ingestion occurs, low leptin levels are observed, leading to a reduction in GnRH (gonadotropin-release hormone), in LH (luteinizing hormone) and FSH (follicle-stimulating hormone) in pituitary, and consequently a minor release of ovarian estrogens. This process is named hypothalamic amenorrhea, and has repercussions in the woman's health. In this perspective, it is important to emphasize the need to evaluate the energy expenditure from exercise and to formulate adequate alimentary plans to these individuals.

  15. The proton pump inhibitor lansoprazole improves the skeletal phenotype in dystrophin deficient mdx mice.

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    Arpana Sali

    Full Text Available In Duchenne muscular dystrophy (DMD, loss of the membrane stabilizing protein dystrophin results in myofiber damage. Microinjury to dystrophic myofibers also causes secondary imbalances in sarcolemmic ion permeability and resting membrane potential, which modifies excitation-contraction coupling and increases proinflammatory/apoptotic signaling cascades. Although glucocorticoids remain the standard of care for the treatment of DMD, there is a need to investigate the efficacy of other pharmacological agents targeting the involvement of imbalances in ion flux on dystrophic pathology.We designed a preclinical trial to investigate the effects of lansoprazole (LANZO administration, a proton pump inhibitor, on the dystrophic muscle phenotype in dystrophin deficient (mdx mice. Eight to ten week-old female mice were assigned to one of four treatment groups (n = 12 per group: (1 vehicle control; (2 5 mg/kg/day LANZO; (3 5 mg/kg/day prednisolone; and (4 combined treatment of 5 mg/kg/day prednisolone (PRED and 5 mg/kg/day LANZO. Treatment was administered orally 5 d/wk for 3 months. At the end of the study, behavioral (Digiscan and functional outcomes (grip strength and Rotarod were assessed prior to sacrifice. After sacrifice, body, tissue and organ masses, muscle histology, in vitro muscle force, and creatine kinase levels were measured. Mice in the combined treatment groups displayed significant reductions in the number of degenerating muscle fibers and number of inflammatory foci per muscle field relative to vehicle control. Additionally, mice in the combined treatment group displayed less of a decline in normalized forelimb and hindlimb grip strength and declines in in vitro EDL force after repeated eccentric contractions.Together our findings suggest that combined treatment of LANZO and prednisolone attenuates some components of dystrophic pathology in mdx mice. Our findings warrant future investigation of the clinical efficacy of LANZO and

  16. Leptin Receptor Deficiency is Associated With Upregulation of Cannabinoid 1 Receptors in Limbic Brain Regions

    Science.gov (United States)

    THANOS, PANAYOTIS K.; RAMALHETE, ROBERTO C.; MICHAELIDES, MICHAEL; PIYIS, YIANNI K.; WANG, GENE-JACK; VOLKOW, NORA D.

    2009-01-01

    Leptin receptor dysfunction results in overeating and obesity. Leptin regulates hypothalamic signaling that underlies the motivation to hyperphagia, but the interaction between leptin and cannabinoid signaling is poorly understood. We evaluated the role of cannabinoid 1 receptors (CB1R) in overeating and the effects of food deprivation on CB1R in the brain. One-month-old Zucker rats were divided into unrestricted and restricted (fed 70% of unrestricted rats) diet groups and maintained until adulthood (4 months). Levels of relative binding sites of CB1R (CB1R binding levels) were assessed using [3H] SR141716A in vitro autoradiography. These levels were higher (except cerebellum and hypothalamus) at 4 months than at 1 month of age. One month CB1R binding levels for most brain regions did not differ between Ob and Lean (Le) rats (except in frontal and cingulate cortices in Le and in the hypothalamus in Ob). Four month Ob rats had higher CB1R binding levels than Le in most brain regions and food restriction was associated with higher CB1R levels in all brain regions in Ob, but not in Le rats. CB1R binding levels increased between adolescence and young adulthood which we believe was influenced by leptin and food availability. The high levels of CB1R in Ob rats suggest that leptin's inhibition of food-intake is in part mediated by downregulation of CB1R and that leptin interferes with CB1R upregulation under food-deprivation conditions. These results are consistent with prior findings showing increased levels of endogenous cannabinoids in the Ob rats corroborating the regulation of cannabinoid signaling by leptin. PMID:18563836

  17. Adaptation of enterovirus 71 to adult interferon deficient mice.

    Directory of Open Access Journals (Sweden)

    Elizabeth A Caine

    Full Text Available Non-polio enteroviruses, including enterovirus 71 (EV71, have caused severe and fatal cases of hand, foot and mouth disease (HFMD in the Asia-Pacific region. The development of a vaccine or antiviral against these pathogens has been hampered by the lack of a reliable small animal model. In this study, a mouse adapted EV71 strain was produced by conducting serial passages through A129 (α/β interferon (IFN receptor deficient and AG129 (α/β, γ IFN receptor deficient mice. A B2 sub genotype of EV71 was inoculated intraperitoneally (i.p. into neonatal AG129 mice and brain-harvested virus was subsequently passaged through 12 and 15 day-old A129 mice. When tested in 10 week-old AG129 mice, this adapted strain produced 100% lethality with clinical signs including limb paralysis, eye irritation, loss of balance, and death. This virus caused only 17% mortality in same age A129 mice, confirming that in the absence of a functional IFN response, adult AG129 mice are susceptible to infection by adapted EV71 isolates. Subsequent studies in adult AG129 and young A129 mice with the adapted EV71 virus examined the efficacy of an inactivated EV71 candidate vaccine and determined the role of humoral immunity in protection. Passive transfer of rabbit immune sera raised against the EV71 vaccine provided protection in a dose dependent manner in 15 day-old A129 mice. Intramuscular injections (i.m. in five week-old AG129 mice with the alum adjuvanted vaccine also provided protection against the mouse adapted homologous strain. No clinical signs of disease or mortality were observed in vaccinated animals, which received a prime-and-boost, whereas 71% of control animals were euthanized after exhibiting systemic clinical signs (P<0.05. The development of this animal model will facilitate studies on EV71 pathogenesis, antiviral testing, the evaluation of immunogenicity and efficacy of vaccine candidates, and has the potential to establish correlates of protection

  18. Novel Toll-like receptor-4 deficiency attenuates trastuzumab (Herceptin induced cardiac injury in mice

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    Yousif Nasser

    2011-10-01

    Full Text Available Abstract Background Cardiac inflammation and generation of oxidative stress are known to contribute to trastuzumab (herceptin induced cardiac toxicity. Toll-like receptors (TLRs are a part of the innate immune system and are involved in cardiac stress reactions. Since TLR4 might play a relevant role in cardiac inflammatory signaling, we investigated whether or not TLR4 is involved in trastuzumab induced cardiotoxicity. Methods Seven days after a single injection of herceptin (2 mg/kg; i.p., left ventricular pressure volume loops were measured in HeN compotent (TLR4+/+ and HeJ mutant (TLR4-/- treated with trastuzumab and control mice. Immunofluorescent staining for monocyte infiltration and analyses of plasma by (ELISAs for different chemokines including: MCP-1and tumor necrosis factor-α (TNF-α, Western immunoblotting assay for ICAM-1, and used troponin I for cardiac injury marker. Results Trastuzumab injection resulted in an impairment of left ventricular function in TLR-4 competent (HeN, in contrast TLR4-/- trastuzumab mice showed improved left ventricular function EF%, CO; p -/-; p -/-, marked reduction of myocardial troponin-I levels in TLR4-deficient mice. Data are presented as means ± SE; n = 8 in each group p Conclusions Treatment with trastuzumab induces an inflammatory response that contributes to myocardial tissue TLR4 mediates chemokine expression (TNF-α, MCP-1and ICAM-1, so in experimental animals TLR4 deficiency improves left ventricular function and attenuates pathophysiological key mechanisms in trastuzumab induced cardiomyopathy.

  19. Altered lipid partitioning and glucocorticoid availability in CBG-deficient male mice with diet-induced obesity.

    Science.gov (United States)

    Gulfo, José; Ledda, Angelo; Serra, Elisabet; Cabot, Cristina; Esteve, Montserrat; Grasa, Mar

    2016-08-01

    To evaluate how deficiency in corticosteroid-binding globulin (CBG), the specific carrier of glucocorticoids, affects glucocorticoid availability and adipose tissue in obesity. C57BL/6 (WT) and CBG-deficient (KO) male mice were fed during 12 weeks with standard or hyperlipidic diet (HL). Glucocorticoid availability and metabolic parameters were assessed. Body weight and food intake were increased in KO compared with WT mice fed a standard diet and were similar when fed a HL diet. Expression of CBG was found in white adipose tissue by immunochemistry, real-time PCR, and Western blot. In obesity, the subcutaneous depot developed less in KO mice compared with WT, which was associated with a minor adipocyte area and peroxisome proliferator-activated receptor-γ expression. Conversely, the epididymal depot displayed higher weight and adipocyte area in KO than in WT mice. CBG deficiency caused a fall of hepatic 11β-hydroxysteroid dehydrogenase type 2 expression and an increase in epidymal adipose tissue, particularly in HL mice. Deficiency in CBG drives lipid partitioning from subcutaneous to visceral adipose depot under a context of lipid excess and differentially modulates 11β-hydroxysteroid dehydrogenase type 2 expression. © 2016 The Obesity Society.

  20. Pervasive and stochastic changes in the TCR repertoire of regulatory T-cell-deficient mice.

    Science.gov (United States)

    Zheng, Lingjie; Sharma, Rahul; Kung, John T; Deshmukh, Umesh S; Jarjour, Wael N; Fu, Shu Man; Ju, Shyr-Te

    2008-04-01

    We hypothesize that regulatory T-cell (Treg)-deficient strains have an altered TCR repertoire in part due to the expansion of autoimmune repertoire by self-antigen. We compared the Vbeta family expression profile between B6 and Treg-lacking B6.Cg-Foxp3(sf)(/Y) (B6.sf) mice using fluorescent anti-Vbeta mAbs and observed no changes. However, while the spectratypes of 20 Vbeta families among B6 mice were highly similar, the Vbeta family spectratypes of B6.sf mice were remarkably different from B6 mice and from each other. Significant spectratype changes in many Vbeta families were also observed in Treg-deficient IL-2 knockout (KO) and IL-2Ralpha KO mice. Such changes were not observed with anti-CD3 mAb-treated B6 mice or B6 CD4+CD25- T cells. TCR transgenic (OT-II.sf) mice displayed dramatic reduction of clonotypic TCR with concomitant increase in T cells bearing non-transgenic Vbeta and Valpha families, including T cells with dual receptors expressing reduced levels of transgenic Valpha and endogenous Valpha. Collectively, the data demonstrate that Treg deficiency allows polyclonal expansion of T cells in a stochastic manner, resulting in widespread changes in the TCR repertoire.

  1. Leptin and insulin responses to a four-day energy-deficient diet in men with different weight history

    NARCIS (Netherlands)

    Mars, M.; de Graaf, C; Rossum, C.T.M; de Groot, C.P.G.M.; Seidell, J C; Kok, F. J.

    2003-01-01

    OBJECTIVE: To assess the leptin responses to a 4-day energy-restricted diet in men with different weight history; high retrospective weight gain was expected to be associated with a small decline in leptin. DESIGN: Changes in fasting leptin and insulin were measured during a 4-day controlled

  2. Deletion of Suppressor of Cytokine Signaling 3 from Forebrain Neurons Delays Infertility and Onset of Hypothalamic Leptin Resistance in Response to a High Caloric Diet.

    Science.gov (United States)

    McEwen, Hayden J L; Inglis, Megan A; Quennell, Janette H; Grattan, David R; Anderson, Greg M

    2016-07-06

    The cellular processes that cause high caloric diet (HCD)-induced infertility are poorly understood but may involve upregulation of suppressor of cytokine signaling (SOCS-3) proteins that are associated with hypothalamic leptin resistance. Deletion of SOCS-3 from brain cells is known to protect mice from diet-induced obesity, but the effects on HCD-induced infertility are unknown. We used neuron-specific SOCS3 knock-out mice to elucidate this and the effects on regional hypothalamic leptin resistance. As expected, male and female neuron-specific SOCS3 knock-out mice were protected from HCD-induced obesity. While female wild-type mice became infertile after 4 months of HCD feeding, infertility onset in knock-out females was delayed by 4 weeks. Similarly, knock-out mice had delayed leptin resistance development in the medial preoptic area and anteroventral periventricular nucleus, regions important for generation of the surge of GnRH and LH that induces ovulation. We therefore tested whether the suppressive effects of HCD on the estradiol-induced GnRH/LH surge were overcome by neuron-specific SOCS3 knock-out. Although only 20% of control HCD-mice experienced a preovulatory-like LH surge, LH surges could be induced in almost all neuron-specific SOCS3 knock-out mice on this diet. In contrast to females, HCD-fed male mice did not exhibit any fertility decline compared with low caloric diet-fed males despite their resistance to the satiety effects of leptin. These data show that deletion of SOCS3 delays the onset of leptin resistance and infertility in HCD-fed female mice, but given continued HCD feeding this state does eventually occur, presumably in response to other mechanisms inhibiting leptin signal transduction. Obesity is commonly associated with infertility in humans and other animals. Treatments for human infertility show a decreased success rate with increasing body mass index. A hallmark of obesity is an increase in circulating leptin levels; despite this, the

  3. Therapeutic potential of flurbiprofen against obesity in mice.

    Science.gov (United States)

    Hosoi, Toru; Baba, Sachiko; Ozawa, Koichiro

    2014-06-20

    Obesity is associated with several diseases including diabetes, nonalcoholic steatohepatitis (NASH), hypertension, cardiovascular disease, and cancer. Therefore, anti-obesity drugs have the potential to prevent these diseases. In the present study, we demonstrated that flurbiprofen, a nonsteroidal anti-inflammatory drug (NSAID), exhibited therapeutic potency against obesity. Mice were fed a high-fat diet (HFD) for 6 months, followed by a normal-chow diet (NCD). The flurbiprofen treatment simultaneously administered. Although body weight was significantly decreased in flurbiprofen-treated mice, growth was not affected. Flurbiprofen also reduced the HFD-induced accumulation of visceral fat. Leptin resistance, which is characterized by insensitivity to the anti-obesity hormone leptin, is known to be involved in the development of obesity. We found that one of the possible mechanisms underlying the anti-obesity effects of flurbiprofen may have been mediated through the attenuation of leptin resistance, because the high circulating levels of leptin in HFD-fed mice were decreased in flurbiprofen-treated mice. Therefore, flurbiprofen may exhibit therapeutic potential against obesity by reducing leptin resistance. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Estrogen deficiency heterogeneously affects tissue specific stem cells in mice

    Science.gov (United States)

    Kitajima, Yuriko; Doi, Hanako; Ono, Yusuke; Urata, Yoshishige; Goto, Shinji; Kitajima, Michio; Miura, Kiyonori; Li, Tao-Sheng; Masuzaki, Hideaki

    2015-01-01

    Postmenopausal disorders are frequently observed in various organs, but their relationship with estrogen deficiency and mechanisms remain unclear. As tissue-specific stem cells have been found to express estrogen receptors, we examined the hypothesis that estrogen deficiency impairs stem cells, which consequently contributes to postmenopausal disorders. Six-week-old C57BL/6 female mice were ovariectomized, following which they received 17β-estradiol replacement or vehicle (control). Sham-operated mice were used as healthy controls. All mice were killed for evaluation 2 months after treatments. Compared with the healthy control, ovariectomy significantly decreased uterine weight, which was partially recovered by 17β-estradiol replacement. Ovariectomy significantly increased the numbers of c-kit-positive hematopoietic stem/progenitor cells in bone marrow, but impaired their capacity to grow mixed cell-type colonies in vitro. Estrogen replacement further increased the numbers of c-kit-positive hematopoietic stem/progenitor cells in bone marrow, without significantly affecting colony growth in vitro. The number of CD105-positive mesenchymal stem cells in bone marrow also significantly decreased after ovariectomy, but completely recovered following estrogen replacement. Otherwise, neither ovariectomy nor estrogen replacement changed the number of Pax7-positive satellite cells, which are a skeletal muscle-type stem cell. Estrogen deficiency heterogeneously affected tissue-specific stem cells, suggesting a likely and direct relationship with postmenopausal disorders. PMID:26245252

  5. Thrombospondin1 deficiency reduces obesity-associated inflammation and improves insulin sensitivity in a diet-induced obese mouse model.

    Directory of Open Access Journals (Sweden)

    Yanzhang Li

    Full Text Available Obesity is prevalent worldwide and is associated with insulin resistance. Advanced studies suggest that obesity-associated low-grade chronic inflammation contributes to the development of insulin resistance and other metabolic complications. Thrombospondin 1 (TSP1 is a multifunctional extracellular matrix protein that is up-regulated in inflamed adipose tissue. A recent study suggests a positive correlation of TSP1 with obesity, adipose inflammation, and insulin resistance. However, the direct effect of TSP1 on obesity and insulin resistance is not known. Therefore, we investigated the role of TSP1 in mediating obesity-associated inflammation and insulin resistance by using TSP1 knockout mice.Male TSP1-/- mice and wild type littermate controls were fed a low-fat (LF or a high-fat (HF diet for 16 weeks. Throughout the study, body weight and fat mass increased similarly between the TSP1-/- mice and WT mice under HF feeding conditions, suggesting that TSP1 deficiency does not affect the development of obesity. However, obese TSP1-/- mice had improved glucose tolerance and increased insulin sensitivity compared to the obese wild type mice. Macrophage accumulation and inflammatory cytokine expression in adipose tissue were reduced in obese TSP1-/- mice. Consistent with the local decrease in pro-inflammatory cytokine levels, systemic inflammation was also decreased in the obese TSP1-/- mice. Furthermore, in vitro data demonstrated that TSP1 deficient macrophages had decreased mobility and a reduced inflammatory phenotype.TSP1 deficiency did not affect the development of high-fat diet induced obesity. However, TSP1 deficiency reduced macrophage accumulation in adipose tissue and protected against obesity related inflammation and insulin resistance. Our data demonstrate that TSP1 may play an important role in regulating macrophage function and mediating obesity-induced inflammation and insulin resistance. These data suggest that TSP1 may serve as a

  6. Modulating the gut microbiota improves glucose tolerance, lipoprotein profile and atherosclerotic plaque development in ApoE-deficient mice

    DEFF Research Database (Denmark)

    Rune, Ida; Rolin, Bidda; Larsen, Christian Schiøth

    2016-01-01

    cause of cardiovascular disease (CVD), and to increase CVD risk factors. Popular interest in the role of the intestine in a variety of disease states has now resulted in a significant proportion of individuals without coeliac disease switching to gluten-free diets. The effect of gluten-free diets...... on atherosclerosis and cardiovascular risk factors is largely unknown. We therefore investigated the effect of a gluten-free high-fat cholesterol-rich diet, as compared to the same diet in which the gluten peptide gliadin had been added back, on atherosclerosis and several cardiovascular risk factors...... in apolipoprotein E-deficient (Apoe-/-) mice. The gluten-free diet transiently altered GM composition in these mice, as compared to the gliadin-supplemented diet, but did not alter body weights, glucose tolerance, insulin levels, plasma lipids, or atherosclerosis. In parallel, other Apoe-/- mice fed the same diets...

  7. Bile acids override steatosis in farnesoid X receptor deficient mice in a model of non-alcoholic steatohepatitis

    International Nuclear Information System (INIS)

    Wu, Weibin; Liu, Xijun; Peng, Xiaomin; Xue, Ruyi; Ji, Lingling; Shen, Xizhong; Chen, She; Gu, Jianxin; Zhang, Si

    2014-01-01

    Highlights: • FXR deficiency enhanced MCD diet-induced hepatic fibrosis. • FXR deficiency attenuated MCD diet-induced hepatic steatosis. • FXR deficiency repressed genes involved in fatty acid uptake and triglyceride accumulation. - Abstract: Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver diseases, and the pathogenesis is still not well known. The farnesoid X receptor (FXR) is a member of the nuclear hormone receptor superfamily and plays an essential role in maintaining bile acid and lipid homeostasis. In this study, we study the role of FXR in the pathogenesis of NFALD. We found that FXR deficient (FXR −/− ) mice fed methionine- and choline-deficient (MCD) diet had higher serum ALT and AST activities and lower hepatic triglyceride levels than wild-type (WT) mice fed MCD diet. Expression of genes involved in inflammation (VCAM-1) and fibrosis (α-SMA) was increased in FXR −/− mice fed MCD diet (FXR −/− /MCD) compared to WT mice fed MCD diet (WT/MCD). Although MCD diet significantly induced hepatic fibrosis in terms of liver histology, FXR −/− /MCD mice showed less degree of hepatic steatosis than WT/MCD mice. Moreover, FXR deficiency synergistically potentiated the elevation effects of MCD diet on serum and hepatic bile acids levels. The super-physiological concentrations of hepatic bile acids in FXR −/− /MCD mice inhibited the expression of genes involved in fatty acid uptake and triglyceride accumulation, which may be an explanation for less steatosis in FXR −/− /MCD mice in contrast to WT/MCD mice. These results suggest that hepatic bile acids accumulation could override simple steatosis in hepatic injury during the progression of NAFLD and further emphasize the role of FXR in maintaining hepatic bile acid homeostasis in liver disorders and in hepatic protection

  8. Bile acids override steatosis in farnesoid X receptor deficient mice in a model of non-alcoholic steatohepatitis

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Weibin; Liu, Xijun; Peng, Xiaomin [Gene Research Center, Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Xue, Ruyi [Department of Gastroenterology and Hepatology, Zhongshan Hospital, Shanghai Institute of Liver Disease, Fudan University, Shanghai 200032 (China); Ji, Lingling [Gene Research Center, Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Shen, Xizhong [Department of Gastroenterology and Hepatology, Zhongshan Hospital, Shanghai Institute of Liver Disease, Fudan University, Shanghai 200032 (China); Chen, She, E-mail: shechen@fudan.edu.cn [Gene Research Center, Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Gu, Jianxin [Gene Research Center, Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Zhang, Si, E-mail: zhangsi@fudan.edu.cn [Gene Research Center, Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China)

    2014-05-23

    Highlights: • FXR deficiency enhanced MCD diet-induced hepatic fibrosis. • FXR deficiency attenuated MCD diet-induced hepatic steatosis. • FXR deficiency repressed genes involved in fatty acid uptake and triglyceride accumulation. - Abstract: Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver diseases, and the pathogenesis is still not well known. The farnesoid X receptor (FXR) is a member of the nuclear hormone receptor superfamily and plays an essential role in maintaining bile acid and lipid homeostasis. In this study, we study the role of FXR in the pathogenesis of NFALD. We found that FXR deficient (FXR{sup −/−}) mice fed methionine- and choline-deficient (MCD) diet had higher serum ALT and AST activities and lower hepatic triglyceride levels than wild-type (WT) mice fed MCD diet. Expression of genes involved in inflammation (VCAM-1) and fibrosis (α-SMA) was increased in FXR{sup −/−} mice fed MCD diet (FXR{sup −/−}/MCD) compared to WT mice fed MCD diet (WT/MCD). Although MCD diet significantly induced hepatic fibrosis in terms of liver histology, FXR{sup −/−}/MCD mice showed less degree of hepatic steatosis than WT/MCD mice. Moreover, FXR deficiency synergistically potentiated the elevation effects of MCD diet on serum and hepatic bile acids levels. The super-physiological concentrations of hepatic bile acids in FXR{sup −/−}/MCD mice inhibited the expression of genes involved in fatty acid uptake and triglyceride accumulation, which may be an explanation for less steatosis in FXR{sup −/−}/MCD mice in contrast to WT/MCD mice. These results suggest that hepatic bile acids accumulation could override simple steatosis in hepatic injury during the progression of NAFLD and further emphasize the role of FXR in maintaining hepatic bile acid homeostasis in liver disorders and in hepatic protection.

  9. Learning and memory in mice with neuropathic pain: impact of old age and progranulin deficiency

    Directory of Open Access Journals (Sweden)

    Boris eAlbuquerque

    2013-11-01

    Full Text Available Persistent neuropathic pain is a frequent consequence of peripheral nerve injuries, particularly in the elderly. Using the IntelliCage we studied if a sciatic nerve injury obstructed learning and memory in young and aged mice, each in wild type and progranulin deficient mice, which develop premature signs of brain aging and are more susceptible to nerve injury evoked nociceptive hypersensitivity and hence allow to assess a potential mutual aggravation of pain and old age. Both young and aged mice developed long-term nerve injury-evoked hyperalgesia and allodynia but, in both genotypes, only aged mice with neuropathic pain showed high error rates in place avoidance acquisition tasks. Once learnt however, aged mice with neuropathic pain maintained the aversive memory longer, i.e. the extinction was significantly slowed. In addition, nerve injury in progranulin deficient mice impaired the learning of spatial sequences of awarded places, particularly in aged mice, whereas easy place preference learning was not affected by nerve injury or progranulin deficiency. The sequencing task required a discrimination of clockwise and anti-clockwise sequences and spatial flexibility to re-learn a novel sequence. The loss of spatial flexibility did not occur in sham operated mice, i.e. was a consequence of nerve injury and suggests that neuropathic pain accelerates manifestations of old age and progranulin deficiency. Neuropathic pain at old age, irrespective of the genotype, resulted in a long maintenance of aversive memory suggesting a negative alliance and possibly mutual aggravation of chronic neuropathic pain and aversive memory at old age.

  10. p53-upregulated-modulator-of-apoptosis (PUMA) deficiency affects food intake but does not impact on body weight or glucose homeostasis in diet-induced obesity.

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    Litwak, Sara A.; Loh, Kim; Stanley, William J.; Pappas, Evan G.; Wali, Jibran A.; Selck, Claudia; Strasser, Andreas; Thomas, Helen E.; Gurzov, Esteban N.

    2016-01-01

    BCL-2 proteins have been implicated in the control of glucose homeostasis and metabolism in different cell types. Thus, the aim of this study was to determine the role of the pro-apoptotic BH3-only protein, p53-upregulated-modulator-of-apoptosis (PUMA), in metabolic changes mediated by diet-induced obesity, using PUMA deficient mice. At 10 weeks of age, knockout and wild type mice either continued consuming a low fat chow diet (6% fat), or were fed with a high fat diet (23% fat) for 14–17 weeks. We measured body composition, glucose and insulin tolerance, insulin response in peripheral tissues, energy expenditure, oxygen consumption, and respiratory exchange ratio in vivo. All these parameters were indistinguishable between wild type and knockout mice on chow diet and were modified equally by diet-induced obesity. Interestingly, we observed decreased food intake and ambulatory capacity of PUMA knockout mice on high fat diet. This was associated with increased adipocyte size and fasted leptin concentration in the blood. Our findings suggest that although PUMA is dispensable for glucose homeostasis in lean and obese mice, it can affect leptin levels and food intake during obesity. PMID:27033313

  11. Wfs1-deficient mice display altered function of serotonergic system and increased behavioural response to antidepressants

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    Tanel eVisnapuu

    2013-07-01

    Full Text Available It has been shown that mutations in the WFS1 gene make humans more susceptible to mood disorders. Besides that, mood disorders are associated with alterations in the activity of serotonergic and noradrenergic systems. Therefore, in this study, the effects of imipramine, an inhibitor of serotonin (5-HT and noradrenaline (NA reuptake, and paroxetine, a selective inhibitor of 5-HT reuptake, were studied in tests of behavioural despair. The tail suspension test (TST and forced swimming test (FST were performed in Wfs1-deficient mice. Simultaneously, gene expression and monoamine metabolism studies were conducted to evaluate changes in 5-HT- and NA-ergic systems of Wfs1-deficient mice. The basal immobility time of Wfs1-deficient mice in TST and FST did not differ from that of their wild-type littermates. However, a significant reduction of immobility time in response to lower doses of imipramine and paroxetine was observed in homozygous Wfs1-deficient mice, but not in their wild-type littermates. In gene expression studies, the levels of 5-HT transporter (SERT were significantly reduced in the pons of homozygous animals. Monoamine metabolism was assayed separately in the dorsal and ventral striatum of naive mice and mice exposed for 30 minutes tobrightly lit motility boxes. We found that this aversive challenge caused a significant increase in the levels of 5-HT and 5-hydroxyindoleacetic acid (5-HIAA, a metabolite of 5-HT, in the ventral and dorsal striatum of wild-type mice, but not in their homozygous littermates. Taken together, the blunted 5-HT metabolism and reduced levels of SERT are a likely reason for the elevated sensitivity of these mice to the action of imipramine and paroxetine. These changes in the pharmacological and neurochemical phenotype of Wfs1-deficient mice may help to explain the increased susceptibility of Wolfram syndrome patients to depressive states.

  12. Germline mutation rates at tandem repeat loci in DNA-repair deficient mice

    International Nuclear Information System (INIS)

    Barber, Ruth C.; Miccoli, Laurent; Buul, Paul P.W. van; Burr, Karen L.-A.; Duyn-Goedhart, Annemarie van; Angulo, Jaime F.; Dubrova, Yuri E.

    2004-01-01

    Mutation rates at two expanded simple tandem repeat (ESTR) loci were studied in the germline of non-exposed and irradiated severe combined immunodeficient (scid) and poly(ADP-ribose) polymerase (PARP-1 -/- ) deficient male mice. Non-exposed scid and PARP -/- male mice showed considerably elevated ESTR mutation rates, far higher than those in wild-type isogenic mice and other inbred strains. The irradiated scid and PARP-1 -/- male mice did not show any detectable increases in their mutation rate, whereas significant ESTR mutation induction was observed in the irradiated wild-type isogenic males. ESTR mutation spectra in the scid and PARP-1 -/- strains did not differ from those in the isogenic wild-type strains. Considering these data and the results of previous studies, we propose that a delay in repair of DNA damage in scid and PARP-1 -/- mice could result in replication fork pausing which, in turn, may affect ESTR mutation rate in the non-irradiated males. The lack of mutation induction in irradiated scid and PARP-1 -/- can be explained by the high cell killing effects of irradiation on the germline of deficient mice

  13. Discovery of the elusive leptin in birds: identification of several 'missing links' in the evolution of leptin and its receptor.

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    Jeremy W Prokop

    Full Text Available Leptin is a pleiotropic protein best known for regulation of appetite and fat storage in mammals. While many leptin orthologs have been identified among vertebrates, an authentic leptin in birds has remained elusive and controversial. Here we identify leptin sequence from the Peregrine falcon, Falco peregrinus (pfleptin, and identify sequences from two other birds (mallard and zebra finch, and 'missing' vertebrates (elephant shark, alligator, Indian python, Chinese soft-shelled turtle, and coelacanth. The pattern of genes surrounding leptin (snd1, rbm28 is syntenic between the falcon and mammalian genomes. Phylogenetic analysis of all known leptin protein sequences improves our understanding of leptin's evolution. Structural modeling of leptin orthologs highlights a highly conserved hydrophobic core in the four-helix cytokine packing domain. A docked model of leptin with the leptin receptor for Peregrine falcon reveals several conserved amino acids important for the interaction and possible coevolution of leptin with its receptor. We also show for the first time, an authentic avian leptin sequence that activates the JAK-STAT signaling pathway. These newly identified sequences, structures, and tools for avian leptin and its receptor will allow elucidation of the function of these proteins in feral and domestic birds.

  14. Diminished exercise capacity and mitochondrial bc1 complex deficiency in tafazzin-knockdown mice.

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    Corey ePowers

    2013-04-01

    Full Text Available The phospholipid, cardiolipin, is essential for maintaining mitochondrial structure and optimal function. Cardiolipin-deficiency in humans, Barth syndrome, is characterized by exercise intolerance, dilated cardiomyopathy, neutropenia and 3-methyl-glutaconic aciduria. The causative gene is the mitochondrial acyl-transferase, tafazzin that is essential for remodeling acyl chains of cardiolipin. We sought to determine metabolic rates in tafazzin-deficient mice during resting and exercise, and investigate the impact of cardiolipin deficiency on mitochondrial respiratory chain activities. Tafazzin knockdown in mice markedly impaired oxygen consumption rates during an exercise, without any significant effect on resting metabolic rates. CL-deficiency resulted in significant reduction of mitochondrial respiratory reserve capacity in neonatal cardiomyocytes that is likely to be caused by diminished activity of complex-III, which requires CL for its assembly and optimal activity. Our results may provide mechanistic insights of Barth syndrome pathogenesis.

  15. Adult vitamin D deficiency exacerbates impairments caused by social stress in BALB/c and C57BL/6 mice.

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    Groves, Natalie J; Zhou, Mei; Jhaveri, Dhanisha J; McGrath, John J; Burne, Thomas H J

    2017-12-01

    Vitamin D deficiency is prevalent in adults throughout the world. Epidemiological studies have shown significant associations between vitamin D deficiency and an increased risk of various neuropsychiatric and neurodegenerative disorders, such as schizophrenia, depression, Alzheimer's disease and cognitive impairment. However, studies based on observational epidemiology cannot address questions of causality; they cannot determine if vitamin D deficiency is a causal factor leading to the adverse health outcome. The main aim of this study was to determine if AVD deficiency would exacerbate the effects of a secondary exposure, in this case social stress, in BALB/c mice and in the more resilient C57BL/6 mice. Ten-week old male BALB/c and C57BL/6 mice were fed a control or vitamin D deficient diet for 10 weeks, and the mice were further separated into one of two groups for social treatment, either Separated (SEP) or Social Defeat (DEF). SEP mice were placed two per cage with a perforated Plexiglas divider, whereas the DEF mice underwent 10days of social defeat prior to behavioural testing. We found that AVD-deficient mice were more vulnerable to the effects of social stress using a social avoidance test, and this was dependent on strain. These results support the hypothesis that vitamin D deficiency may exacerbate behavioural outcomes in mice vulnerable to stress, a finding that can help guide future studies. Importantly, these discoveries support the epidemiological link between vitamin D deficiency and neuropsychiatric and neurodegenerative disorders; and has provided clues that can guide future studies related to unravelling the mechanisms of action linking adult vitamin D deficiency and adverse brain related outcomes. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  16. Taste bud leptin: sweet dampened at initiation site.

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    Travers, Susan P; Frank, Marion E

    2015-05-01

    The intriguing observation that leptin decreases sweet-evoked peripheral gustatory responses has aroused much interest (Kawai K, Sugimoto K, Nakashima K, Miura H, Ninomiya Y. 2000. Leptin as a modulator of sweet taste sensitivities in mice. Proc Natl Acad Sci U S A. 97(20):11044-11049.) due to its implied importance in controlling appetite. The effects of this anorexic hormone, however, appear more conditional than originally believed. In this issue of Chemical Senses, a careful study by Glendinning and colleagues, find no effects of leptin on sweet-evoked chorda tympani responses, whereas an equally careful study by Meredith and colleagues, find decreased release of ATP and increased release of 5-HT from taste buds in response to sweet stimuli. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Effect of high fat diet on pulmonary expression of parathyroid hormone-related protein and its downstream targets

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    Learta Oruqaj

    2016-10-01

    Full Text Available Aims: Parathyroid hormone-related protein (PTHrP is involved in lung development and surfactant production. The latter one requires a paracrine interaction between type II alveolar cells and lipofibroblasts in which leptin triggers PTHrP-induced effects. Whether increased plasma leptin levels, as they occur in high fat diet, modify the expression of PTHrP remains unclear. Furthermore, the effect of high fat diet under conditions of forced pulmonary remodelling such as response to post myocardial infarction remains to be defined. Materials and methods: C57 bl/6 mice were randomized to either normal diet or high fat diet at an age of 6 weeks. Seven months later, the mice were euthanized and the lung was removed and frozen in fluid nitrogen until use. Samples were analyzed by real-time RT-PCR and western blot. Leptin deficient mice were used to investigate the effect of leptin on pulmonary expression of PTHrP more directly. A subgroup of mice with and without high fat diet underwent in vivo ischemia (45 min and reperfusion (4 weeks. Finally, experiments were repeated with prolonged high-fat diet. Key findings: High fat diet increased plasma leptin levels by 30.4% and the pulmonary mRNA expression of PTHrP (1,447-fold, PTH-1 receptor (4.21-fold, and PTHrP-downstream targets ADRP (7.54-fold and PPARγ (5.27-fold. Pulmonary PTHrP expression was reduced in leptin deficient mice by 88% indicating leptin dependent regulation. High fat diet further improved changes in pulmonary adaptation caused by ischemia/reperfusion (1.48-fold increased PTH-1 receptor protein expression. These effects were lost during prolonged high fat diet. Significance: This study established that physiological regulation of leptin plasma levels by high fat diet affects the pulmonary PTHrP expression and of PTHrP downstream targets. Modification of pulmonary expression of PTH-1 receptors by high fat diet after myocardial infarction suggests that the identified interaction may

  18. RIPK3 Mediates Necroptosis during Embryonic Development and Postnatal Inflammation in Fadd-Deficient Mice

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    Qun Zhao

    2017-04-01

    Full Text Available RIPK3 mediates cell death and regulates inflammatory responses. Although genetic studies have suggested that RIPK3-MLKL-mediated necroptosis leads to embryonic lethality in Fadd or Caspase-8-deficient mice, the exact mechanisms are not fully understood. Here, we generated Ripk3 mutant mice by altering the RIPK3 kinase domain (Ripk3Δ/Δ mice, thus abolishing its kinase activity. Ripk3Δ/Δ cells were resistant to necroptosis stimulation in vitro, and Ripk3Δ/Δ mice were protected from necroptotic diseases. Although the Ripk3Δ/Δ mutation rescued embryonic lethality in Fadd−/− embryos, Fadd−/− Ripk3Δ/Δ mice died within 1 day after birth due to massive inflammation. These results indicate that Ripk3 ablation rescues embryonic lethality in Fadd-deficient mice by suppressing two RIPK3-mediating processes: necroptosis during embryogenesis and inflammation during postnatal development in Fadd−/− mice.

  19. Alleviation of lipopolysaccharide/d-galactosamine-induced liver injury in leukocyte cell-derived chemotaxin 2 deficient mice

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    Akinori Okumura

    2017-12-01

    Full Text Available Leukocyte cell-derived chemotaxin 2 (LECT2 is a secreted pleiotropic protein that is mainly produced by the liver. We have previously shown that LECT2 plays an important role in the pathogenesis of inflammatory liver diseases. Lipopolysaccharide/d-galactosamine (LPS/d-GalN-induced acute liver injury is a known animal model of fulminant hepatic failure. Here we found that this hepatic injury was alleviated in LECT2-deficient mice. The levels of TNF-α and IFN-γ, which mediate this hepatitis, had significantly decreased in these mice, with the decrease in IFN-γ production notably greater than that in TNF-α. We therefore analyzed IFN-γ-producing cells in liver mononuclear cells. Flow cytometric analysis showed significantly reduced IFN-γ production in hepatic NK and NKT cells in LECT2-deficient mice compared with in wild-type mice. We also demonstrated a decrease in IFN-γ production in LECT2-deficient mice after systemic administration of recombinant IL-12, which is known to induce IFN-γ in NK and NKT cells. These results indicate that a decrease of IFN-γ production in NK and NKT cells was involved in the alleviation of LPS/d-GalN-induced liver injury in LECT2-deficient mice.

  20. TAP1-deficiency does not alter atherosclerosis development in Apoe-/- mice.

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    Daniel Kolbus

    Full Text Available Antigen presenting cells (APC have the ability to present both extra-cellular and intra-cellular antigens via MHC class I molecules to CD8(+ T cells. The cross presentation of extra-cellular antigens is reduced in mice with deficient Antigen Peptide Transporter 1 (TAP1-dependent MHC class I antigen presentation, and these mice are characterized by a diminished CD8(+ T cell population. We have recently reported an increased activation of CD8(+ T cells in hypercholesterolemic Apoe(-/- mice. Therefore, this study included TAP1-deficient Apoe(-/- mice (Apoe(-/-Tap1(-/- to test the atherogenicity of CD8(+ T cells and TAP1-dependent cross presentation in a hypercholesterolemic environment. As expected the CD8(+ T cell numbers were low in Apoe(-/-Tap1(-/- mice in comparison to Apoe(-/- mice, constituting ~1% of the lymphocyte population. In spite of this there were no differences in the extent of atherosclerosis as assessed by en face Oil Red O staining of the aorta and cross-sections of the aortic root between Apoe(-/-Tap1(-/- and Apoe(-/- mice. Moreover, no differences were detected in lesion infiltration of macrophages or CD3(+ T cells in Apoe(-/-Tap1(-/- compared to Apoe(-/- mice. The CD3(+CD4(+ T cell fraction was increased in Apoe(-/-Tap1(-/- mice, suggesting a compensation for the decreased CD8(+ T cell population. Interestingly, the fraction of CD8(+ effector memory T cells was increased but this appeared to have little impact on the atherosclerosis development.In conclusion, Apoe(-/-Tap1(-/- mice develop atherosclerosis equal to Apoe(-/- mice, indicating a minor role for CD8(+ T cells and TAP1-dependent antigen presentation in the disease process.

  1. Activation of c-Raf-1 kinase signal transduction pathway in alpha(7) integrin-deficient mice.

    Science.gov (United States)

    Saher, G; Hildt, E

    1999-09-24

    Integrin alpha(7)-deficient mice develop a novel form of muscular dystrophy. Here we report that deficiency of alpha(7) integrin causes an activation of the c-Raf-1/mitogen-activated protein (MAP) 2 kinase signal transduction pathway in muscle cells. The observed activation of c-Raf-1/MAP2 kinases is a specific effect, because the alpha(7) integrin deficiency does not cause unspecific stress as determined by measurement of the Hsp72/73 level and activity of the JNK2 kinase. Because an increased level of activated FAK was found in muscle of alpha(7) integrin-deficient mice, the activation of c-Raf-1 kinase is triggered most likely by an integrin-dependent pathway. In accordance with this, in the integrin alpha(7)-deficient mice, part of the integrin beta(1D) variant in muscle is replaced by the beta(1A) variant, which permits the FAK activation. A recent report describes that integrin activity can be down-modulated by the c-Raf-1/MAP2 kinase pathway. Specific activation of the c-Raf-1/MAP2 kinases by cell-permeable peptides in skeletal muscle of rabbits causes degeneration of muscle fibers. Therefore, we conclude that in alpha(7) integrin-deficient mice, the continuous activation of c-Raf-1 kinase causes a permanent reduction of integrin activity diminishing integrin-dependent cell-matrix interactions and thereby contributing to the development of the dystrophic phenotype.

  2. Leptin in pediatrics: A hormone from adipocyte that wheels several functions in children

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    Ashraf T Soliman

    2012-01-01

    Full Text Available The protein leptin, a pleiotropic hormone regulates appetite and energy balance of the body and plays important roles in controlling linear growth, pubertal development, cardiovascular function, and immunity. Recent findings in the understanding of the structure, functional roles, and clinical significance of conditions with increased and decreased leptin secretion are summarized. Balance between leptin and other hormones is significantly regulated by nutritional status. This balance influences many organ systems, including the brain, liver, and skeletal muscle, to mediate the essential adaptation process. The aim of this review is to summarize the possible physiological functions of leptin and its signaling pathways during childhood and adolescence including control of food intake, energy regulation, growth and puberty, and immunity. Moreover, its secretion and possible roles in the adaptation process during different disease states (obesity, malnutrition, eating disorders, delayed puberty, congenital heart diseases and hepatic disorders are discussed. The clinical manifestations and the successful management of patients with genetic leptin deficiency and the application of leptin therapy in other diseases including lipodystrophy, states with severe insulin resistance, and diabetes mellitus are discussed.

  3. Leptin in pediatrics: A hormone from adipocyte that wheels several functions in children

    Science.gov (United States)

    Soliman, Ashraf T.; Yasin, Mohamed; Kassem, Ahmed

    2012-01-01

    The protein leptin, a pleiotropic hormone regulates appetite and energy balance of the body and plays important roles in controlling linear growth, pubertal development, cardiovascular function, and immunity. Recent findings in the understanding of the structure, functional roles, and clinical significance of conditions with increased and decreased leptin secretion are summarized. Balance between leptin and other hormones is significantly regulated by nutritional status. This balance influences many organ systems, including the brain, liver, and skeletal muscle, to mediate the essential adaptation process. The aim of this review is to summarize the possible physiological functions of leptin and its signaling pathways during childhood and adolescence including control of food intake, energy regulation, growth and puberty, and immunity. Moreover, its secretion and possible roles in the adaptation process during different disease states (obesity, malnutrition, eating disorders, delayed puberty, congenital heart diseases and hepatic disorders) are discussed. The clinical manifestations and the successful management of patients with genetic leptin deficiency and the application of leptin therapy in other diseases including lipodystrophy, states with severe insulin resistance, and diabetes mellitus are discussed. PMID:23565493

  4. Relationship between peripheral leptin receptor and leptin in obese subjects

    International Nuclear Information System (INIS)

    Sun Junjiang; Du Tongxin; Wang Zizheng; Wang Shukui; Huang Min

    2002-01-01

    Objective: To investigate the relationship between leptin resistance and leptin receptor in obese subjects. Methods: Forty-four individuals undergoing surgery, exclusive of diabetic mellitus, chronic inflammatory and malignant diseases, were divided into 3 groups according to the body mass index (BMI), normal controls (n=15), weight excess (n=14), and obesity group (n=15). Fasting serum leptin were detected via ELISA kits, leptin receptor (Bmax) in peripheral adipose tissues was detected by radioligand assay. Results: Serum leptin levels were higher significantly in weight excess and obesity cases groups (10.3±4.45 and 13.2±3.26 vs 5.51±3.23 μg/L, both P<0.05, respectively) compared with normal control group, suggesting the existence of leptin resistance, while the leptin receptor of the weight excess and obese groups decreased significantly than that of normal control group (36.9 ± 5.89 and 24.3 ± 3.95 vs 76.5 ± 35.3 fmol/mg protein, both P<0.01, respectively), there was no statistical differences for Kd value among three groups. Also, there was a negative correlation between BMI and leptin receptor (r=-0.613, P<0.05), and no significant correlation was found between serum leptin and peripheral leptin receptor. Conclusion: The result suggested that there was expression of leptin receptor in peripheral adipose tissues and low level of leptin receptor expression may contribute to the development of leptin resistance and obesity

  5. Angiotensin II blockade causes acute renal failure in eNOS-deficient mice

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    Jürgen Schnermann

    2001-03-01

    Full Text Available Compared with wild-type mice, adult endothelial nitric oxide synthase (eNOS knockout mice (eight months of age have increased blood pressure (BP (126±9 mmHg vs. 100±4 mmHg, and an increased renal vascular resistance (155±16 vs. 65±4 mmHg.min/ml. Renal vascular resistance responses to i.v. administration of noradrenaline were markedly enhanced in eNOS knockout mice. Glomerular filtration rate (GFR of anaesthetised eNOS -/- mice was 324±57 µl/min gKW, significantly lower than the GFR of 761±126 µl/min.gKW in wild-type mice. AT1-receptor blockade with i.v. candesartan (1—1.5 mg/kg reduced arterial blood pressure and renal vascular resistance, and increased renal blood flow (RBF to about the same extent in wild-type and eNOS -/- mice. Candesartan did not alter GFR in wild-type mice (761±126 vs. 720±95 µl/min.gKW, but caused a marked decrease in GFR in eNOS -/- mice (324.5±75.2 vs. 77±18 µl/min.gKW. A similar reduction in GFR of eNOS deficient mice was also caused by angiotensin-converting enzyme (ACE inhibition. Afferent arteriolar granularity, a measure of renal renin expression, was found to be reduced in eNOS -/- compared with wild-type mice. In chronically eNOS-deficient mice, angiotensin II (Ang II is critical for maintaining glomerular filtration pressure and GFR, presumably through its effect on efferent arteriolar tone.

  6. Delayed onset of experimental autoimmune encephalomyelitis in Olig1 deficient mice.

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    Xiaoli Guo

    Full Text Available BACKGROUND: Olig1 is a basic helix-loop-helix (bHLH transcription factor that is essential for oligodendrogenesis and efficient remyelination. However, its role in neurodegenerative disorders has not been well-elucidated. METHODOLOGY/PRINCIPAL FINDINGS: Here we investigated the effects of Olig1 deficiency on experimental autoimmune encephalomyelitis (EAE, an animal model of multiple sclerosis (MS. We show that the mean disease onset of myelin oligodendrocyte glycoprotein (MOG-induced EAE in Olig1(-/- mice is significantly slower than wide-type (WT mice (19.8 ± 2.2 in Olig1(-/- mice and 9.5 ± 0.3 days in WT mice. In addition, 10% of Olig1(-/- mice did not develop EAE by the end of the observation periods (60 days. The severity of EAE, the extent of demyelination, and the activation of microglial cells and astrocytes in spinal cords, were significantly milder in Olig1(-/- mice compared with WT mice in the early stage. Moreover, the visual function, as assessed by the second-kernel of multifocal electroretinograms, was better preserved, and the number of degenerating axons in the optic nerve was significantly reduced in Olig1(-/- mice. Interestingly, Olig1 deficiency had no effect on T cell response capability, however, it reduced the expression of myelin proteins such as MOG, myelin basic protein (MBP and myelin-associated glycoprotein (MAG. The expression of Olig2 remained unchanged in the optic nerve and brain, and it was reduced in the spinal cord of Olig1(-/- mice. CONCLUSIONS/SIGNIFICANCE: Our results suggest that the Olig1 signaling pathways may be involved in the incidence rate and the severity of neurological symptoms in MS.

  7. Serotonin 5-HT2C receptor-independent expression of hypothalamic NOR1, a novel modulator of food intake and energy balance, in mice

    International Nuclear Information System (INIS)

    Nonogaki, Katsunori; Kaji, Takao; Ohba, Yukie; Sumii, Makiko; Wakameda, Mamoru; Tamari, Tomohiro

    2009-01-01

    NOR1, Nur77 and Nurr1 are orphan nuclear receptors and members of the NR4A subfamily. Here, we report that the expression of hypothalamic NOR1 was remarkably decreased in mildly obese β-endorphin-deficient mice and obese db/db mice with the leptin receptor mutation, compared with age-matched wild-type mice, whereas there were no genotypic differences in the expression of hypothalamic Nur77 or Nurr1 in these animals. The injection of NOR1 siRNA oligonucleotide into the third cerebral ventricle significantly suppressed food intake and body weight in mice. On the other hand, the decreases in hypothalamic NOR1 expression were not found in non-obese 5-HT2C receptor-deficient mice. Moreover, systemic administration of m-chlorophenylpiperazine (mCPP), a 5-HT2C/1B receptor agonist, had no effect on hypothalamic NOR1 expression, while suppressing food intake in β-endorphin-deficient mice. These findings suggest that 5-HT2C receptor-independent proopiomelanocortin-derived peptides regulate the expression of hypothalamic NOR1, which is a novel modulator of feeding behavior and energy balance.

  8. Serotonin 5-HT2C receptor-independent expression of hypothalamic NOR1, a novel modulator of food intake and energy balance, in mice

    Energy Technology Data Exchange (ETDEWEB)

    Nonogaki, Katsunori, E-mail: knonogaki-tky@umin.ac.jp [Center of Excellence, Division of Molecular Metabolism and Diabetes, Tohoku University Graduate School of Medicine (Japan); Department of Lifestyle Medicine, Biomedical Engineering Center, Tohoku University (Japan); Kaji, Takao [Department of Lifestyle Medicine, Biomedical Engineering Center, Tohoku University (Japan); Ohba, Yukie; Sumii, Makiko [Center of Excellence, Division of Molecular Metabolism and Diabetes, Tohoku University Graduate School of Medicine (Japan); Wakameda, Mamoru; Tamari, Tomohiro [Charles River Laboratories Japan, Inc. (Japan)

    2009-08-21

    NOR1, Nur77 and Nurr1 are orphan nuclear receptors and members of the NR4A subfamily. Here, we report that the expression of hypothalamic NOR1 was remarkably decreased in mildly obese {beta}-endorphin-deficient mice and obese db/db mice with the leptin receptor mutation, compared with age-matched wild-type mice, whereas there were no genotypic differences in the expression of hypothalamic Nur77 or Nurr1 in these animals. The injection of NOR1 siRNA oligonucleotide into the third cerebral ventricle significantly suppressed food intake and body weight in mice. On the other hand, the decreases in hypothalamic NOR1 expression were not found in non-obese 5-HT2C receptor-deficient mice. Moreover, systemic administration of m-chlorophenylpiperazine (mCPP), a 5-HT2C/1B receptor agonist, had no effect on hypothalamic NOR1 expression, while suppressing food intake in {beta}-endorphin-deficient mice. These findings suggest that 5-HT2C receptor-independent proopiomelanocortin-derived peptides regulate the expression of hypothalamic NOR1, which is a novel modulator of feeding behavior and energy balance.

  9. Autism-like Deficits in Shank3-Deficient Mice Are Rescued by Targeting Actin Regulators

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    Lara J. Duffney

    2015-06-01

    Full Text Available Haploinsufficiency of the Shank3 gene, which encodes a scaffolding protein at glutamatergic synapses, is a highly prevalent and penetrant risk factor for autism. Using combined behavioral, electrophysiological, biochemical, imaging, and molecular approaches, we find that Shank3-deficient mice exhibit autism-like social deficits and repetitive behaviors, as well as the significantly diminished NMDA receptor (NMDAR synaptic function and synaptic distribution in prefrontal cortex. Concomitantly, Shank3-deficient mice have a marked loss of cortical actin filaments, which is associated with the reduced Rac1/PAK activity and increased activity of cofilin, the major actin depolymerizing factor. The social deficits and NMDAR hypofunction are rescued by inhibiting cofilin or activating Rac1 in Shank3-deficient mice and are induced by inhibiting PAK or Rac1 in wild-type mice. These results indicate that the aberrant regulation of synaptic actin filaments and loss of synaptic NMDARs contribute to the manifestation of autism-like phenotypes. Thus, targeting actin regulators provides a strategy for autism treatment.

  10. Leptin actions on food intake and body temperature are mediated by IL-1.

    Science.gov (United States)

    Luheshi, G N; Gardner, J D; Rushforth, D A; Loudon, A S; Rothwell, N J

    1999-06-08

    Leptin regulates energy balance through its actions in the brain on appetite and energy expenditure and also shares properties with cytokines such as IL-1. We report here that leptin, injected into rats intracerebroventricularly or peripherally, induces significant dose-dependent increases in core body temperature as well as suppression of appetite. Leptin failed to affect food intake or body temperature in obese (fa/fa) Zucker rats, which posses a defective leptin receptor. Furthermore, injection of leptin increased levels of the proinflammatory cytokine IL-1beta in the hypothalamus of normal Sprague-Dawley rats. Central injection of IL-1 receptor antagonist (IL-1ra) inhibited the suppression of food intake caused by central or peripheral injection of leptin (60 and 84%, respectively) and abolished the leptin-induced increase in body temperature in both cases. Mice lacking (gene knockout) the main IL-1 receptor (80 kDa, R1) responsible for IL-1 actions showed no reduction in food intake in response to leptin. These data indicate that leptin actions in the brain depend on IL-1, and we show further that the effect of leptin on fever, but not food intake, is abolished by a cyclooxygenase inhibitor. Thus, we propose that in addition to its role in body weight regulation, leptin may mediate neuroimmune responses via actions in the brain dependent on release of IL-1 and prostaglandins.

  11. Somato-dendritic localization and signaling by leptin receptors in hypothalamic POMC and AgRP neurons.

    Directory of Open Access Journals (Sweden)

    Sangdeuk Ha

    Full Text Available Leptin acts via neuronal leptin receptors to control energy balance. Hypothalamic pro-opiomelanocortin (POMC and agouti-related peptide (AgRP/Neuropeptide Y (NPY/GABA neurons produce anorexigenic and orexigenic neuropeptides and neurotransmitters, and express the long signaling form of the leptin receptor (LepRb. Despite progress in the understanding of LepRb signaling and function, the sub-cellular localization of LepRb in target neurons has not been determined, primarily due to lack of sensitive anti-LepRb antibodies. Here we applied light microscopy (LM, confocal-laser scanning microscopy (CLSM, and electron microscopy (EM to investigate LepRb localization and signaling in mice expressing a HA-tagged LepRb selectively in POMC or AgRP/NPY/GABA neurons. We report that LepRb receptors exhibit a somato-dendritic expression pattern. We further show that LepRb activates STAT3 phosphorylation in neuronal fibers within several hypothalamic and hindbrain nuclei of wild-type mice and rats, and specifically in dendrites of arcuate POMC and AgRP/NPY/GABA neurons of Leprb (+/+ mice and in Leprb (db/db mice expressing HA-LepRb in a neuron specific manner. We did not find evidence of LepRb localization or STAT3-signaling in axon-fibers or nerve-terminals of POMC and AgRP/NPY/GABA neurons. Three-dimensional serial EM-reconstruction of dendritic segments from POMC and AgRP/NPY/GABA neurons indicates a high density of shaft synapses. In addition, we found that the leptin activates STAT3 signaling in proximity to synapses on POMC and AgRP/NPY/GABA dendritic shafts. Taken together, these data suggest that the signaling-form of the leptin receptor exhibits a somato-dendritic expression pattern in POMC and AgRP/NPY/GABA neurons. Dendritic LepRb signaling may therefore play an important role in leptin's central effects on energy balance, possibly through modulation of synaptic activity via post-synaptic mechanisms.

  12. Lessons learned from mice deficient in lectin complement pathway molecules

    DEFF Research Database (Denmark)

    Genster, Ninette; Takahashi, Minoru; Sekine, Hideharu

    2014-01-01

    in turn activate downstream complement components, ultimately leading to elimination of the pathogen. Mice deficient in the key molecules of lectin pathway of complement have been generated in order to build knowledge of the molecular mechanisms of the lectin pathway in health and disease. Despite......The lectin pathway of the complement system is initiated when the pattern-recognition molecules, mannose-binding lectin (MBL), ficolins or collectin-11, bind to invading pathogens or damaged host cells. This leads to activation of MBL/ficolin/collectin-11 associated serine proteases (MASPs), which...... differences in the genetic arrangements of murine and human orthologues of lectin pathway molecules, the knockout mice have proven to be valuable models to explore the effect of deficiency states in humans. In addition, new insight and unexpected findings on the diverse roles of lectin pathway molecules...

  13. Cardiac dysfunction in Pkd1-deficient mice with phenotype rescue by galectin-3 knockout

    Science.gov (United States)

    Balbo, Bruno E.; Amaral, Andressa G.; Fonseca, Jonathan M.; de Castro, Isac; Salemi, Vera M.; Souza, Leandro E.; dos Santos, Fernando; Irigoyen, Maria C.; Qian, Feng; Chammas, Roger; Onuchic, Luiz F.

    2016-01-01

    Alterations in myocardial wall texture stand out among ADPKD cardiovascular manifestations, in hypertensive and normotensive patients. To elucidate their pathogenesis, we analyzed the cardiac phenotype in Pkd1cond/cond:Nestincre (CYG+) cystic mice exposed to increased blood pressure, at 5–6 and 20–24 weeks of age, and Pkd1+/− (HTG+) noncystic mice at 5–6 and 10–13 weeks. Echocardiographic analyses revealed decreased myocardial deformation and systolic function in CYG+ and HTG+ mice, as well as diastolic dysfunction in older CYG+ mice, compared to their Pkd1cond/cond and Pkd1+/+ controls. Hearts from CYG+ and HTG+ mice presented reduced polycystin-1 expression, increased apoptosis and mild fibrosis. Since galectin-3 has been associated with heart dysfunction, we studied it as a potential modifier of the ADPKD cardiac phenotype. Double-mutant Pkd1cond/cond:Nestincre;Lgals3−/− (CYG−) and Pkd1+/−;Lgals3−/− (HTG−) mice displayed improved cardiac deformability and systolic parameters compared to single-mutants, not differing from their controls. CYG− and HTG− showed decreased apoptosis and fibrosis. Analysis of a severe cystic model (Pkd1V/V; VVG+) showed that Pkd1V/V;Lgals3−/− (VVG−) mice have longer survival, decreased cardiac apoptosis and improved heart function compared to VVG+. CYG− and VVG− animals showed no difference in renal cystic burden compared to CYG+ and VVG+ mice. Thus, myocardial dysfunction occurs in different Pkd1-deficient models and suppression of galectin-3 expression rescues this phenotype. PMID:27475230

  14. Intranasal siRNA administration reveals IGF2 deficiency contributes to impaired cognition in Fragile X syndrome mice.

    Science.gov (United States)

    Pardo, Marta; Cheng, Yuyan; Velmeshev, Dmitry; Magistri, Marco; Eldar-Finkelman, Hagit; Martinez, Ana; Faghihi, Mohammad A; Jope, Richard S; Beurel, Eleonore

    2017-03-23

    Molecular mechanisms underlying learning and memory remain imprecisely understood, and restorative interventions are lacking. We report that intranasal administration of siRNAs can be used to identify targets important in cognitive processes and to improve genetically impaired learning and memory. In mice modeling the intellectual deficiency of Fragile X syndrome, intranasally administered siRNA targeting glycogen synthase kinase-3β (GSK3β), histone deacetylase-1 (HDAC1), HDAC2, or HDAC3 diminished cognitive impairments. In WT mice, intranasally administered brain-derived neurotrophic factor (BDNF) siRNA or HDAC4 siRNA impaired learning and memory, which was partially due to reduced insulin-like growth factor-2 (IGF2) levels because the BDNF siRNA- or HDAC4 siRNA-induced cognitive impairments were ameliorated by intranasal IGF2 administration. In Fmr1 -/- mice, hippocampal IGF2 was deficient, and learning and memory impairments were ameliorated by IGF2 intranasal administration. Therefore intranasal siRNA administration is an effective means to identify mechanisms regulating cognition and to modulate therapeutic targets.

  15. Increased demyelination and axonal damage in metallothionein I+II-deficient mice during experimental autoimmune encephalomyelitis

    DEFF Research Database (Denmark)

    Penkowa, M; Espejo, C; Martínez-Cáceres, E M

    2003-01-01

    Metallothioneins I+II (MT-I+II) are antioxidant, neuroprotective factors. We previously showed that MT-I+II deficiency during experimental autoimmune encephalomyelitis (EAE) leads to increased disease incidence and clinical symptoms. Moreover, the inflammatory response of macrophages and T cells......, oxidative stress, and apoptotic cell death during EAE were increased by MT-I+II deficiency. We now show for the first time that demyelination and axonal damage are significantly increased in MT-I+II deficient mice during EAE. Furthermore, oligodendroglial regeneration, growth cone formation, and tissue...... repair including expression of trophic factors were significantly reduced in MT-I+II-deficient mice during EAE. Accordingly, MT-I+II have protective and regenerative roles in the brain....

  16. LEPTIN AND OBESITY – NEUROENDOCRINE , METABOLIC AND ATHEROGENIC EFFECTS OF LEPTIN

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    Mišo Šabovič

    2003-01-01

    Full Text Available Background. Leptin is an adipocyte-derived hormone that was recently discovered. Leptin and leptin resistance play an important role in the pathogenesis of obesity. Leptin acts by binding to specific receptors in the hypothalamus to alter the expression of several neuropeptides that regulate food intake and energy expenditure. As commonly found, obese persons have leptin resistance and consequently attenuated effects of leptin. Mechanism underlying leptin resistance has not been explained yet: it might be the result of a receptor or post receptor defect, impaired transport of leptin through cerebrovascular barrier or inactivation of leptin by binding proteins. Phase I and II clinical trials proved that recombinant leptin administration to humans is safe. First results of the current phase III clinical trials demonstrated that leptin is moderately effective in the treatment of obesity.Conclusions. Beside anti-obesity effect, leptin can have important metabolic and neuroendocrine effects. It is involved in glucose metabolism and insulin secretion, pathogenesis of polymetabolic syndrome, diabetes and arterial hypertension. In addition it affects some processes of atherothrombosis. It interacts with and significantly influences hypothalamic-pituitaryadrenal, thyroid, sexual glands and growth hormone axes. Explaining the mechanism of leptin resistance could be important for understanding the pathogenesis of obesity and associated pathologic states as polymetabolic syndrom, diabetes, arterial hipertension and atherothrombosis.

  17. Leptin reverses hyperglycemia and hyperphagia in insulin deficient diabetic rats by pituitary-independent central nervous system actions.

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    Alexandre A da Silva

    Full Text Available The hypothalamic-pituitary-adrenal (HPA axis has been postulated to play a major role in mediating the antidiabetic effects of leptin. We tested if the pituitary is essential for the chronic central nervous system mediated actions of leptin on metabolic and cardiovascular function in insulin-dependent diabetic and non-diabetic rats. Male 12-week-old hypophysectomized Sprague-Dawley rats (Hypo, n = 5 were instrumented with telemetry probes for determination of mean arterial pressure (MAP and heart rate (HR 24-hrs/day and an intracerebroventricular (ICV cannula was placed into the brain lateral ventricle for continuous leptin infusion. In additional groups of Hypo and control rats (n = 5/group, diabetes was induced by single injection of streptozotocin (50 mg/kg, IP. Hypo rats were lighter, had lower MAP and HR (83±4 and 317±2 vs 105±4 mmHg and 339±4 bpm, with similar caloric intake per kilogram of body weight and fasting plasma glucose levels (84±4 vs 80±4 mg/dl compared to controls. Chronic ICV leptin infusion (7 days, 0.62 μg/hr in non-diabetic rats reduced caloric intake and body weight (-10% in Hypo and control rats and markedly increased HR in control rats (~25 bpm while causing only modest HR increases in Hypo rats (8 bpm. In diabetic Hypo and control rats, leptin infusion reduced caloric intake, body weight and glucose levels (323±74 to 99±20 and 374±27 to 108±10 mg/dl, respectively; however, the effects of leptin on HR were abolished in Hypo rats. These results indicate that hypophysectomy attenuates leptin's effect on HR regulation without altering leptin's ability to suppress appetite or normalize glucose levels in diabetes.

  18. Deficiency of the Erc/mesothelin gene ameliorates renal carcinogenesis in Tsc2 knockout mice.

    Science.gov (United States)

    Zhang, Danqing; Kobayashi, Toshiyuki; Kojima, Tetsuo; Kanenishi, Kenji; Hagiwara, Yoshiaki; Abe, Masaaki; Okura, Hidehiro; Hamano, Yoshitomo; Sun, Guodong; Maeda, Masahiro; Jishage, Kou-ichi; Noda, Tetsuo; Hino, Okio

    2011-04-01

    Genetic crossing experiments were performed between tuberous sclerosis-2 (Tsc2) KO and expressed in renal carcinoma (Erc) KO mice to analyze the function of the Erc/mesothelin gene in renal carcinogenesis. We found the number and size of renal tumors were significantly less in Tsc2+/-;Erc-/- mice than in Tsc2+/-;Erc+/+ and Tsc2+/-;Erc+/- mice. Tumors from Tsc2+/-;Erc-/- mice exhibited reduced cell proliferation and increased apoptosis, as determined by proliferating cell nuclear antigen (Ki67) and TUNEL analysis, respectively. Adhesion to collagen-coated plates in vitro was enhanced in Erc-restored cells and decreased in Erc-suppressed cells with siRNA. Tumor formation by Tsc2-deficient cells in nude mice was remarkably suppressed by stable knockdown of Erc with shRNA. Western blot analysis showed that the phosphorylation of focal adhesion kinase, Akt and signal transducer and activator of transcription protein 3 were weaker in Erc-deficient/suppressed cells compared with Erc-expressed cells. These results indicate that deficiency of the Erc/mesothelin gene ameliorates renal carcinogenesis in Tsc2 KO mice and inhibits the phosphorylation of several kinases of cell adhesion mechanism. This suggests that Erc/mesothelin may have an important role in the promotion and/or maintenance of carcinogenesis by influencing cell-substrate adhesion via the integrin-related signal pathway. © 2011 Japanese Cancer Association.

  19. Live attenuated S. Typhimurium vaccine with improved safety in immuno-compromised mice.

    Directory of Open Access Journals (Sweden)

    Balamurugan Periaswamy

    Full Text Available Live attenuated vaccines are of great value for preventing infectious diseases. They represent a delicate compromise between sufficient colonization-mediated adaptive immunity and minimizing the risk for infection by the vaccine strain itself. Immune defects can predispose to vaccine strain infections. It has remained unclear whether vaccine safety could be improved via mutations attenuating a vaccine in immune-deficient individuals without compromising the vaccine's performance in the normal host. We have addressed this hypothesis using a mouse model for Salmonella diarrhea and a live attenuated Salmonella Typhimurium strain (ssaV. Vaccination with this strain elicited protective immunity in wild type mice, but a fatal systemic infection in immune-deficient cybb(-/-nos2(-/- animals lacking NADPH oxidase and inducible NO synthase. In cybb(-/-nos2(-/- mice, we analyzed the attenuation of 35 ssaV strains carrying one additional mutation each. One strain, Z234 (ssaV SL1344_3093, was >1000-fold attenuated in cybb(-/-nos2(-/- mice and ≈100 fold attenuated in tnfr1(-/- animals. However, in wt mice, Z234 was as efficient as ssaV with respect to host colonization and the elicitation of a protective, O-antigen specific mucosal secretory IgA (sIgA response. These data suggest that it is possible to engineer live attenuated vaccines which are specifically attenuated in immuno-compromised hosts. This might help to improve vaccine safety.

  20. Zinc deficiency with reduced mastication impairs spatial memory in young adult mice.

    Science.gov (United States)

    Kida, Kumiko; Tsuji, Tadataka; Tanaka, Susumu; Kogo, Mikihiko

    2015-12-01

    Sufficient oral microelements such as zinc and fully chewing of foods are required to maintain cognitive function despite aging. No knowledge exists about the combination of factors such as zinc deficiency and reduced mastication on learning and memory. Here we show that tooth extraction only in 8-week-old mice did not change the density of glial fibrillary acidic protein-labeled astrocytes in the hippocampus or spatial memory parameters. However, tooth extraction followed by zinc deprivation strongly impaired spatial memory and led to an increase in astrocytic density in the hippocampal CA1 region. The impaired spatial performance in the zinc-deficient only (ZD) mice also coincided well with the increase in the astrocytic density in the hippocampal CA1 region. After switching both zinc-deficient groups to a normal diet with sufficient zinc, spatial memory recovered, and more time was spent in the quadrant with the goal in the probe test in the mice with tooth extraction followed by zinc deprivation (EZD) compared to the ZD mice. Interestingly, we found no differences in astrocytic density in the CA1 region among all groups at 22 weeks of age. Furthermore, the escape latency in a visible probe test at all times was longer in zinc-deficient groups than the others and demonstrated a negative correlation with body weight. No significant differences in escape latency were observed in the visible probe test among the ZD, EZD, and normal-fed control at 4 weeks (CT4w) groups in which body weight was standardized to that of the EZD group, or in the daily reduction in latency between the normal-fed control and CT4w groups. Our data showed that zinc-deficient feeding during a young age impairs spatial memory performance and leads to an increase in astrocytic density in the hippocampal CA1 region and that zinc-sufficient feeding is followed by recovery of the impaired spatial memory along with changes in astrocytic density. The combination of the two factors, zinc deficiency

  1. Severe osteogenesis imperfecta in cyclophilin B-deficient mice.

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    Jae Won Choi

    2009-12-01

    Full Text Available Osteogenesis Imperfecta (OI is a human syndrome characterized by exquisitely fragile bones due to osteoporosis. The majority of autosomal dominant OI cases result from point or splice site mutations in the type I collagen genes, which are thought to lead to aberrant osteoid within developing bones. OI also occurs in humans with homozygous mutations in Prolyl-3-Hydroxylase-1 (LEPRE1. Although P3H1 is known to hydroxylate a single residue (pro-986 in type I collagen chains, it is unclear how this modification acts to facilitate collagen fibril formation. P3H1 exists in a complex with CRTAP and the peptidyl-prolyl isomerase cyclophilin B (CypB, encoded by the Ppib gene. Mutations in CRTAP cause OI in mice and humans, through an unknown mechanism, while the role of CypB in this complex has been a complete mystery. To study the role of mammalian CypB, we generated mice lacking this protein. Early in life, Ppib-/- mice developed kyphosis and severe osteoporosis. Collagen fibrils in Ppib-/- mice had abnormal morphology, further consistent with an OI phenotype. In vitro studies revealed that in CypB-deficient fibroblasts, procollagen did not localize properly to the golgi. We found that levels of P3H1 were substantially reduced in Ppib-/- cells, while CRTAP was unaffected by loss of CypB. Conversely, knockdown of either P3H1 or CRTAP did not affect cellular levels of CypB, but prevented its interaction with collagen in vitro. Furthermore, knockdown of CRTAP also caused depletion of cellular P3H1. Consistent with these changes, post translational prolyl-3-hydroxylation of type I collagen by P3H1 was essentially absent in CypB-deficient cells and tissues from CypB-knockout mice. These data provide significant new mechanistic insight into the pathophysiology of OI and reveal how the members of the P3H1/CRTAP/CypB complex interact to direct proper formation of collagen and bone.

  2. Severe Osteogenesis Imperfecta in Cyclophilin B–Deficient Mice

    Science.gov (United States)

    Choi, Jae Won; Sutor, Shari L.; Lindquist, Lonn; Evans, Glenda L.; Madden, Benjamin J.; Bergen, H. Robert; Hefferan, Theresa E.; Yaszemski, Michael J.; Bram, Richard J.

    2009-01-01

    Osteogenesis Imperfecta (OI) is a human syndrome characterized by exquisitely fragile bones due to osteoporosis. The majority of autosomal dominant OI cases result from point or splice site mutations in the type I collagen genes, which are thought to lead to aberrant osteoid within developing bones. OI also occurs in humans with homozygous mutations in Prolyl-3-Hydroxylase-1 (LEPRE1). Although P3H1 is known to hydroxylate a single residue (pro-986) in type I collagen chains, it is unclear how this modification acts to facilitate collagen fibril formation. P3H1 exists in a complex with CRTAP and the peptidyl-prolyl isomerase cyclophilin B (CypB), encoded by the Ppib gene. Mutations in CRTAP cause OI in mice and humans, through an unknown mechanism, while the role of CypB in this complex has been a complete mystery. To study the role of mammalian CypB, we generated mice lacking this protein. Early in life, Ppib-/- mice developed kyphosis and severe osteoporosis. Collagen fibrils in Ppib-/- mice had abnormal morphology, further consistent with an OI phenotype. In vitro studies revealed that in CypB–deficient fibroblasts, procollagen did not localize properly to the golgi. We found that levels of P3H1 were substantially reduced in Ppib-/- cells, while CRTAP was unaffected by loss of CypB. Conversely, knockdown of either P3H1 or CRTAP did not affect cellular levels of CypB, but prevented its interaction with collagen in vitro. Furthermore, knockdown of CRTAP also caused depletion of cellular P3H1. Consistent with these changes, post translational prolyl-3-hydroxylation of type I collagen by P3H1 was essentially absent in CypB–deficient cells and tissues from CypB–knockout mice. These data provide significant new mechanistic insight into the pathophysiology of OI and reveal how the members of the P3H1/CRTAP/CypB complex interact to direct proper formation of collagen and bone. PMID:19997487

  3. Severe osteogenesis imperfecta in cyclophilin B-deficient mice.

    Science.gov (United States)

    Choi, Jae Won; Sutor, Shari L; Lindquist, Lonn; Evans, Glenda L; Madden, Benjamin J; Bergen, H Robert; Hefferan, Theresa E; Yaszemski, Michael J; Bram, Richard J

    2009-12-01

    Osteogenesis Imperfecta (OI) is a human syndrome characterized by exquisitely fragile bones due to osteoporosis. The majority of autosomal dominant OI cases result from point or splice site mutations in the type I collagen genes, which are thought to lead to aberrant osteoid within developing bones. OI also occurs in humans with homozygous mutations in Prolyl-3-Hydroxylase-1 (LEPRE1). Although P3H1 is known to hydroxylate a single residue (pro-986) in type I collagen chains, it is unclear how this modification acts to facilitate collagen fibril formation. P3H1 exists in a complex with CRTAP and the peptidyl-prolyl isomerase cyclophilin B (CypB), encoded by the Ppib gene. Mutations in CRTAP cause OI in mice and humans, through an unknown mechanism, while the role of CypB in this complex has been a complete mystery. To study the role of mammalian CypB, we generated mice lacking this protein. Early in life, Ppib-/- mice developed kyphosis and severe osteoporosis. Collagen fibrils in Ppib-/- mice had abnormal morphology, further consistent with an OI phenotype. In vitro studies revealed that in CypB-deficient fibroblasts, procollagen did not localize properly to the golgi. We found that levels of P3H1 were substantially reduced in Ppib-/- cells, while CRTAP was unaffected by loss of CypB. Conversely, knockdown of either P3H1 or CRTAP did not affect cellular levels of CypB, but prevented its interaction with collagen in vitro. Furthermore, knockdown of CRTAP also caused depletion of cellular P3H1. Consistent with these changes, post translational prolyl-3-hydroxylation of type I collagen by P3H1 was essentially absent in CypB-deficient cells and tissues from CypB-knockout mice. These data provide significant new mechanistic insight into the pathophysiology of OI and reveal how the members of the P3H1/CRTAP/CypB complex interact to direct proper formation of collagen and bone.

  4. Effects of aqueous extract of Portulaca oleracea L. on oxidative stress and liver, spleen leptin, PARα and FAS mRNA expression in high-fat diet induced mice.

    Science.gov (United States)

    Chen, Bendong; Zhou, Haining; Zhao, Wenchao; Zhou, Wenyan; Yuan, Quan; Yang, Guangshun

    2012-08-01

    We reported that an aqueous extract of Portulaca oleracea L. inhibited high-fat-diet-induced oxidative injury in a dose-dependent manner. Male kunming mice (5-weeks-old, 24 g) were used in this experiment. After a 4-day adaptation period, animals were randomly divided into four groups (n = 10 in each group); Group 1: animals received normal powdered rodent diet; Group 2: animals received high fat diet; Groups 3 and 4: animals received high fat diet and were fed by gavage to mice once a day with aqueous extract at the doses of 100 and 200 mg/kg body weight, respectively. In mice fed with high-fat diet, blood and liver lipid peroxidation level was significantly increased, whereas antioxidant enzymes activities were markedly decreased compared to normal control mice. Administration of an aqueous extract of P. oleracea L. significantly dose-dependently reduced levels of blood and liver lipid peroxidation and increased the activities of blood and liver antioxidant enzymes activities in high fat mice. Moreover, administration of an aqueous extract of P. oleracea L. significantly dose-dependently increase liver Leptin/β-actin (B), and Liver PPARα/β-actin, decrease liver, spleen FAS mRNA, p-PERK and p-PERK/PERK protein expression levels. Taken together, these data demonstrate that aqueous extract of P. oleracea L. can markedly alleviate high fat diet-induced oxidative injury by enhancing blood and liver antioxidant enzyme activities, modulating Leptin/β-actin (B), and Liver PPARα/β-actin, decrease liver, spleen FAS mRNA, p-PERK and p-PERK/PERK protein expression levels in mice.

  5. The anti-tumor activity of a neutralizing nanobody targeting leptin receptor in a mouse model of melanoma.

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    Travis McMurphy

    Full Text Available Environmental and genetic activation of a brain-adipocyte axis inhibits cancer progression. Leptin is the primary peripheral mediator of this anticancer effect in a mouse model of melanoma. In this study we assessed the effect of a leptin receptor antagonist on melanoma progression. Local administration of a neutralizing nanobody targeting the leptin receptor at low dose adjacent to tumor decreased tumor mass with no effects on body weight or food intake. In contrast, systemic administration of the nanobody failed to suppress tumor growth. Daily intraperitoneal injection of high-dose nanobody led to weight gain, hyperphagia, increased adiposity, hyperleptinemia, and hyperinsulinemia, and central effects mimicking leptin deficiency. The blockade of central actions of leptin by systemic delivery of nanobody may compromise its anticancer effect, underscoring the need to develop peripherally acting leptin antagonists coupled with efficient cancer-targeting delivery.

  6. The anti-tumor activity of a neutralizing nanobody targeting leptin receptor in a mouse model of melanoma.

    Science.gov (United States)

    McMurphy, Travis; Xiao, Run; Magee, Daniel; Slater, Andrew; Zabeau, Lennart; Tavernier, Jan; Cao, Lei

    2014-01-01

    Environmental and genetic activation of a brain-adipocyte axis inhibits cancer progression. Leptin is the primary peripheral mediator of this anticancer effect in a mouse model of melanoma. In this study we assessed the effect of a leptin receptor antagonist on melanoma progression. Local administration of a neutralizing nanobody targeting the leptin receptor at low dose adjacent to tumor decreased tumor mass with no effects on body weight or food intake. In contrast, systemic administration of the nanobody failed to suppress tumor growth. Daily intraperitoneal injection of high-dose nanobody led to weight gain, hyperphagia, increased adiposity, hyperleptinemia, and hyperinsulinemia, and central effects mimicking leptin deficiency. The blockade of central actions of leptin by systemic delivery of nanobody may compromise its anticancer effect, underscoring the need to develop peripherally acting leptin antagonists coupled with efficient cancer-targeting delivery.

  7. Human cathepsin L rescues the neurodegeneration and lethality incathepsin B/L double deficient mice

    Energy Technology Data Exchange (ETDEWEB)

    Sevenich, Lisa; Pennacchio, Len A.; Peters, Christoph; Reinheckel, Thomas

    2006-01-09

    Cathepsin B (CTSB) and cathepsin L (CTSL) are two widelyexpressed cysteine proteases thought to predominantly reside withinlysosomes. Functional analysis of CTSL in humans is complicated by theexistence of two CTSL-like homologues (CTSL and CTSL2), in contrast tomice which contain only one CTSL enzyme. Thus transgenic expression ofhuman CTSL in CTSL deficient mice provides an opportunity to study the invivo functions of this human protease without interference by its highlyrelated homologue. While mice with single gene deficiencies for murineCTSB or CTSL survive without apparent neuromuscular impairment, murineCTSB/CTSL double deficient mice display degeneration of cerebellarPurkinje cells and neurons of the cerebral cortex, resulting in severehypotrophy, motility defects, and lethality during their third to fourthweek of life. Here we show that expression of human CTSL through agenomic transgene results in widespread expression of human CTSL in themouse which is capable of rescuing the lethality found in CTSB/CTSLdouble-deficient animals. Human CTSL is expressed in the brain of thesecompound mutants predominantly in neurons of the cerebral cortex and inPurkinje cells of the cerebellum, where it appears to prevent neuronalcell death.

  8. Enzyme replacement therapy rescues weakness and improves muscle pathology in mice with X-linked myotubular myopathy.

    Science.gov (United States)

    Lawlor, Michael W; Armstrong, Dustin; Viola, Marissa G; Widrick, Jeffrey J; Meng, Hui; Grange, Robert W; Childers, Martin K; Hsu, Cynthia P; O'Callaghan, Michael; Pierson, Christopher R; Buj-Bello, Anna; Beggs, Alan H

    2013-04-15

    No effective treatment exists for patients with X-linked myotubular myopathy (XLMTM), a fatal congenital muscle disease caused by deficiency of the lipid phosphatase, myotubularin. The Mtm1δ4 and Mtm1 p.R69C mice model severely and moderately symptomatic XLMTM, respectively, due to differences in the degree of myotubularin deficiency. Contractile function of intact extensor digitorum longus (EDL) and soleus muscles from Mtm1δ4 mice, which produce no myotubularin, is markedly impaired. Contractile forces generated by chemically skinned single fiber preparations from Mtm1δ4 muscle were largely preserved, indicating that weakness was largely due to impaired excitation contraction coupling. Mtm1 p.R69C mice, which produce small amounts of myotubularin, showed impaired contractile function only in EDL muscles. Short-term replacement of myotubularin with a prototypical targeted protein replacement agent (3E10Fv-MTM1) in Mtm1δ4 mice improved contractile function and muscle pathology. These promising findings suggest that even low levels of myotubularin protein replacement can improve the muscle weakness and reverse the pathology that characterizes XLMTM.

  9. Differential effect of ionizing radiation on transcription in repair-deficient and repair-proficient mice

    International Nuclear Information System (INIS)

    Munson, G.P.; Woloschak, G.E.

    1990-01-01

    Experiments were designed to examine in vivo changes in total transcription and in the expression of the c-fos gene following whole-body exposure of mice to JANUS fission-spectrum neutrons. Radiation repair-deficient (wst/wst) and -proficient (wst/., C57BL/6 x C3H F1) mice were exposed to JANUS fission-spectrum neutrons calibrated to deliver a gut dose of 50 cGy. Animals were sacrificed less than 10 or at 60 min postirradiation, and gut tissues were removed for study. Our results revealed that, in repair-proficient mice, an immediate depression (relative to untreated control) in total transcription was evident that continued through 1 h postirradiation. Conversely, radiation-sensitive wst/wst mice displayed doubled transcription levels postirradiation. Expression of c-fos was consistently depressed following radiation exposure in control and wst/wst mice. However, the depression of c-fos mRNA was delayed in wst/wst mice relative to controls. These results demonstrate abnormal regulation of transcription and of c-fos mRNA accumulation in repair-deficient wasted mice following exposure to ionizing radiation. In addition, this work documents rapid total transcriptional depression in normal mice following radiation exposure

  10. Aged PROP1 deficient dwarf mice maintain ACTH production.

    Directory of Open Access Journals (Sweden)

    Igor O Nasonkin

    Full Text Available Humans with PROP1 mutations have multiple pituitary hormone deficiencies (MPHD that typically advance from growth insufficiency diagnosed in infancy to include more severe growth hormone (GH deficiency and progressive reduction in other anterior pituitary hormones, eventually including adrenocorticotropic hormone (ACTH deficiency and hypocortisolism. Congenital deficiencies of GH, prolactin, and thyroid stimulating hormone have been reported in the Prop1(null (Prop1(-/- and the Ames dwarf (Prop1(df/df mouse models, but corticotroph and pituitary adrenal axis function have not been thoroughly investigated. Here we report that the C57BL6 background sensitizes mutants to a wasting phenotype that causes approximately one third to die precipitously between weaning and adulthood, while remaining homozygotes live with no signs of illness. The wasting phenotype is associated with severe hypoglycemia. Circulating ACTH and corticosterone levels are elevated in juvenile and aged Prop1 mutants, indicating activation of the pituitary-adrenal axis. Despite this, young adult Prop1 deficient mice are capable of responding to restraint stress with further elevation of ACTH and corticosterone. Low blood glucose, an expected side effect of GH deficiency, is likely responsible for the elevated corticosterone level. These studies suggest that the mouse model differs from the human patients who display progressive hormone loss and hypocortisolism.

  11. Growth hormone modulates hypothalamic inflammation in long-lived pituitary dwarf mice.

    Science.gov (United States)

    Sadagurski, Marianna; Landeryou, Taylor; Cady, Gillian; Kopchick, John J; List, Edward O; Berryman, Darlene E; Bartke, Andrzej; Miller, Richard A

    2015-12-01

    Mice in which the genes for growth hormone (GH) or GH receptor (GHR(-/-) ) are disrupted from conception are dwarfs, possess low levels of IGF-1 and insulin, have low rates of cancer and diabetes, and are extremely long-lived. Median longevity is also increased in mice with deletion of hypothalamic GH-releasing hormone (GHRH), which leads to isolated GH deficiency. The remarkable extension of longevity in hypopituitary Ames dwarf mice can be reversed by a 6-week course of GH injections started at the age of 2 weeks. Here, we demonstrate that mutations that interfere with GH production or response, in the Snell dwarf, Ames dwarf, or GHR(-/-) mice lead to reduced formation of both orexigenic agouti-related peptide (AgRP) and anorexigenic proopiomelanocortin (POMC) projections to the main hypothalamic projection areas: the arcuate nucleus (ARH), paraventricular nucleus (PVH), and dorsomedial nucleus (DMH). These mutations also reduce hypothalamic inflammation in 18-month-old mice. GH injections, between 2 and 8 weeks of age, reversed both effects in Ames dwarf mice. Disruption of GHR specifically in liver (LiGHRKO), a mutation that reduces circulating IGF-1 but does not lead to lifespan extension, had no effect on hypothalamic projections or inflammation, suggesting an effect of GH, rather than peripheral IGF-1, on hypothalamic development. Hypothalamic leptin signaling, as monitored by induction of pStat3, is not impaired by GHR deficiency. Together, these results suggest that early-life disruption of GH signaling produces long-term hypothalamic changes that may contribute to the longevity of GH-deficient and GH-resistant mice. © 2015 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  12. Failure of pulmonary clearance of Rhodococcus equi infection in CD4+ T-lymphocyte-deficient transgenic mice.

    OpenAIRE

    Kanaly, S T; Hines, S A; Palmer, G H

    1993-01-01

    Pulmonary clearance of Rhodococcus equi requires functional T lymphocytes. In this study, CD8+ T-lymphocyte-deficient transgenic mice cleared virulent R. equi from the lungs while infection in CD4+ T-lymphocyte-deficient transgenic mice persisted. Although both CD4+ and CD8+ T cells function early in pulmonary defense against R. equi, clearance is dependent on CD4+ T lymphocytes.

  13. Increased numbers of spleen colony forming units in B cell deficient CBA/N mice

    International Nuclear Information System (INIS)

    Wiktor-Jedrzejczak, W.; Krupienicz, A.; Scher, I.

    1986-01-01

    The formation of exogenous and endogenous spleen colonies was studied in immune-defective mice expressing the CBA/N X-linked xid gene. Bone marrow and spleen cells of immune deficient mice formed increased numbers of eight-day exogenous spleen colonies when transferred to either normal or B cell deficient lethally irradiated recipients. Moreover, defective mice showed increased formation of five-day endogenous spleen colonies (derived from transient endogenous colony forming units; T-CFU) and of ten-day endogenous spleen colonies (derived from CFU-S). Among the possible mechanisms responsible for the observed effects, the most probable appears the one in which decreased numbers of B cell precursors stimulate stem cell pools through a feedback mechanism. (orig.) [de

  14. Leptin Suppresses the Rewarding Effects of Running via STAT3 Signaling in Dopamine Neurons.

    Science.gov (United States)

    Fernandes, Maria Fernanda A; Matthys, Dominique; Hryhorczuk, Cécile; Sharma, Sandeep; Mogra, Shabana; Alquier, Thierry; Fulton, Stephanie

    2015-10-06

    The adipose hormone leptin potently influences physical activity. Leptin can decrease locomotion and running, yet the mechanisms involved and the influence of leptin on the rewarding effects of running ("runner's high") are unknown. Leptin receptor (LepR) signaling involves activation of signal transducer and activator of transcription-3 (STAT3), including in dopamine neurons of the ventral tegmental area (VTA) that are essential for reward-relevant behavior. We found that mice lacking STAT3 in dopamine neurons exhibit greater voluntary running, an effect reversed by viral-mediated STAT3 restoration. STAT3 deletion increased the rewarding effects of running whereas intra-VTA leptin blocked it in a STAT3-dependent manner. Finally, STAT3 loss-of-function reduced mesolimbic dopamine overflow and function. Findings suggest that leptin influences the motivational effects of running via LepR-STAT3 modulation of dopamine tone. Falling leptin is hypothesized to increase stamina and the rewarding effects of running as an adaptive means to enhance the pursuit and procurement of food. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Female Nur77-deficient mice show increased susceptibility to diet-induced obesity.

    Directory of Open Access Journals (Sweden)

    Sonia Perez-Sieira

    Full Text Available Adipose tissue is essential in the regulation of body weight. The key process in fat catabolism and the provision of energy substrate during times of nutrient deprivation or enhanced energy demand is the hydrolysis of triglycerides and the release of fatty acids and glycerol. Nur77 is a member of the NR4A subfamily of nuclear receptors that plays an important metabolic role, modulating hepatic glucose metabolism and lipolysis in muscle. However, its endogenous role on white adipose tissue, as well as the gender dependency of these mechanisms, remains largely unknown. Male and female wild type and Nur77 deficient mice were fed with a high fat diet (45% calories from fat for 4 months. Mice were analyzed in vivo with the indirect calorimetry system, and tissues were analyzed by real-time PCR and Western blot analysis. Female, but not male Nur77 deficient mice, gained more weight and fat mass when compared to wild type mice fed with high fat diet, which can be explained by decreased energy expenditure. The lack of Nur77 also led to a decreased pHSL/HSL ratio in white adipose tissue and increased expression of CIDEA in brown adipose tissue of female Nur77 deficient mice. Overall, these findings suggest that Nur77 is an important physiological modulator of lipid metabolism in adipose tissue and that there are gender differences in the sensitivity to deletion of the Nur77 signaling. The decreased energy expenditure and the actions of Nur77 on liver, muscle, brown and white adipose tissue contribute to the increased susceptibility to diet-induced obesity in females lacking Nur77.

  16. Hypothalamic glycogen synthase kinase 3β has a central role in the regulation of food intake and glucose metabolism.

    Science.gov (United States)

    Benzler, Jonas; Ganjam, Goutham K; Krüger, Manon; Pinkenburg, Olaf; Kutschke, Maria; Stöhr, Sigrid; Steger, Juliane; Koch, Christiane E; Ölkrug, Rebecca; Schwartz, Michael W; Shepherd, Peter R; Grattan, David R; Tups, Alexander

    2012-10-01

    GSK3β (glycogen synthase kinase 3β) is a ubiquitous kinase that plays a key role in multiple intracellular signalling pathways, and increased GSK3β activity is implicated in disorders ranging from cancer to Alzheimer's disease. In the present study, we provide the first evidence of increased hypothalamic signalling via GSK3β in leptin-deficient Lep(ob/ob) mice and show that intracerebroventricular injection of a GSK3β inhibitor acutely improves glucose tolerance in these mice. The beneficial effect of the GSK3β inhibitor was dependent on hypothalamic signalling via PI3K (phosphoinositide 3-kinase), a key intracellular mediator of both leptin and insulin action. Conversely, neuron-specific overexpression of GSK3β in the mediobasal hypothalamus exacerbated the hyperphagia, obesity and impairment of glucose tolerance induced by a high-fat diet, while having little effect in controls fed standard chow. These results demonstrate that increased hypothalamic GSK3β signalling contributes to deleterious effects of leptin deficiency and exacerbates high-fat diet-induced weight gain and glucose intolerance.

  17. Beneficial Effect of Leptin on Spatial Learning and Memory in Streptozotocin-Induced Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Mohsen Ghasemi

    2016-02-01

    Full Text Available Background: Diabetes mellitus is a chronic disease which may be accompanied by cognitive impairments. The expression of the obesity gene (ob is decreased in insulin-deficient diabetic animals and increased after the administration of insulin or leptin. Plasma leptin levels are reduced in the streptozotocin (STZ-induced diabetic rats. Therefore, the deleterious effects of diabetes on memory may be due to the reduction of leptin. Aims: Investigate the effect of subcutaneous injection of leptin on spatial learning and memory in STZ-induced diabetic rats. Study Design: Animal experimentation. Methods: The rats were divided into three groups: 1- control, 2- diabetic, and 3- diabetic-leptin. Diabetes was induced in groups 2 and 3 by STZ injection (55 mg/kg intraperitoneally (i.p. The animals received leptin (0.1 mg/kg or saline subcutaneously (s.c for 10 days before behavioral studies. Then, they were examined in the Morris water maze over 3 blocks after 3 days of the last injection of leptin. Results: The travelled path length and time spent to reach the platform significantly increased in the diabetic group (p<0.001 and decreased with leptin treatment (p<0.01 & p<0.001 respectively; also, a significant increase in path length and time was observed between the diabetic-leptin group and the diabetic group (p<0.01, p<0.001, respectively in the probe test. Conclusion: Leptin can exert positive effects on memory impairments in diabetic rats.

  18. Crif1 Deficiency Reduces Adipose OXPHOS Capacity and Triggers Inflammation and Insulin Resistance in Mice

    Science.gov (United States)

    Ryu, Min Jeong; Kim, Soung Jung; Kim, Yong Kyung; Choi, Min Jeong; Tadi, Surendar; Lee, Min Hee; Lee, Seong Eun; Chung, Hyo Kyun; Jung, Saet Byel; Kim, Hyun-Jin; Jo, Young Suk; Kim, Koon Soon; Lee, Sang-Hee; Kim, Jin Man; Kweon, Gi Ryang; Park, Ki Cheol; Lee, Jung Uee; Kong, Young Yun; Lee, Chul-Ho; Chung, Jongkyeong; Shong, Minho

    2013-01-01

    Impaired mitochondrial oxidative phosphorylation (OXPHOS) has been proposed as an etiological mechanism underlying insulin resistance. However, the initiating organ of OXPHOS dysfunction during the development of systemic insulin resistance has yet to be identified. To determine whether adipose OXPHOS deficiency plays an etiological role in systemic insulin resistance, the metabolic phenotype of mice with OXPHOS–deficient adipose tissue was examined. Crif1 is a protein required for the intramitochondrial production of mtDNA–encoded OXPHOS subunits; therefore, Crif1 haploinsufficient deficiency in mice results in a mild, but specific, failure of OXPHOS capacity in vivo. Although adipose-specific Crif1-haploinsufficient mice showed normal growth and development, they became insulin-resistant. Crif1-silenced adipocytes showed higher expression of chemokines, the expression of which is dependent upon stress kinases and antioxidant. Accordingly, examination of adipose tissue from Crif1-haploinsufficient mice revealed increased secretion of MCP1 and TNFα, as well as marked infiltration by macrophages. These findings indicate that the OXPHOS status of adipose tissue determines its metabolic and inflammatory responses, and may cause systemic inflammation and insulin resistance. PMID:23516375

  19. Alanyl-glutamine attenuates 5-fluorouracil-induced intestinal mucositis in apolipoprotein E-deficient mice

    Directory of Open Access Journals (Sweden)

    C.V. Araújo

    2015-06-01

    Full Text Available Apolipoprotein E (APOE=gene, apoE=protein is a known factor regulating the inflammatory response that may have regenerative effects during tissue recovery from injury. We investigated whether apoE deficiency reduces the healing effect of alanyl-glutamine (Ala-Gln treatment, a recognized gut-trophic nutrient, during tissue recovery after 5-FU-induced intestinal mucositis. APOE-knockout (APOE-/- and wild-type (APOE+/+ C57BL6J male and female mice (N=86 were given either Ala-Gln (100 mM or phosphate buffered saline (PBS by gavage 3 days before and 5 days after a 5-fluorouracil (5-FU challenge (450 mg/kg, via intraperitoneal injection. Mouse body weight was monitored daily. The 5-FU cytotoxic effect was evaluated by leukometry. Intestinal villus height, villus/crypt ratio, and villin expression were monitored to assess recovery of the intestinal absorptive surface area. Crypt length, mitotic, apoptotic, and necrotic crypt indexes, and quantitative real-time PCR for insulin-like growth factor-1 (IGF-1 and B-cell lymphoma 2 (Bcl-2 intestinal mRNA transcripts were used to evaluate intestinal epithelial cell turnover. 5-FU challenge caused significant weight loss and leukopenia (P<0.001 in both mouse strains, which was not improved by Ala-Gln. Villus blunting, crypt hyperplasia, and reduced villus/crypt ratio (P<0.05 were found in all 5-FU-challenged mice but not in PBS controls. Ala-Gln improved villus/crypt ratio, crypt length and mitotic index in all challenged mice, compared with PBS controls. Ala-Gln improved villus height only in APOE-/- mice. Crypt cell apoptosis and necrotic scores were increased in all mice challenged by 5-FU, compared with untreated controls. Those scores were significantly lower in Ala-Gln-treated APOE+/+ mice than in controls. Bcl-2 and IGF-1 mRNA transcripts were reduced only in the APOE-/--challenged mice. Altogether our findings suggest APOE-independent Ala-Gln regenerative effects after 5-FU challenge.

  20. Alanyl-glutamine attenuates 5-fluorouracil-induced intestinal mucositis in apolipoprotein E-deficient mice

    Energy Technology Data Exchange (ETDEWEB)

    Araújo, C.V. [Laboratório da Biologia da Cicatrização, Ontogenia e Nutrição de Tecidos, INCT - Instituto de Biomedicina do Semiárido Brasileiro, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil); Lazzarotto, C.R. [Laboratório de Biologia Molecular e do Desenvolvimento, Universidade de Fortaleza, Fortaleza, CE (Brazil); Aquino, C.C.; Figueiredo, I.L.; Costa, T.B.; Oliveira Alves, L.A. de [Laboratório da Biologia da Cicatrização, Ontogenia e Nutrição de Tecidos, INCT - Instituto de Biomedicina do Semiárido Brasileiro, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil); Ribeiro, R.A. [Laboratório da Inflamação e Câncer, INCT - Instituto de Biomedicina do Semiárido Brasileiro, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil); Bertolini, L.R. [Laboratório de Biologia Molecular e do Desenvolvimento, Universidade de Fortaleza, Fortaleza, CE (Brazil); Lima, A.A.M. [Laboratório de Doenças Infecciosas, INCT - Instituto de Biomedicina do Semiárido Brasileiro, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil); Brito, G.A.C. [Laboratório da Inflamação e Câncer, INCT - Instituto de Biomedicina do Semiárido Brasileiro, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil); Oriá, R.B. [Laboratório da Biologia da Cicatrização, Ontogenia e Nutrição de Tecidos, INCT - Instituto de Biomedicina do Semiárido Brasileiro, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, CE (Brazil)

    2015-04-28

    Apolipoprotein E (APOE=gene, apoE=protein) is a known factor regulating the inflammatory response that may have regenerative effects during tissue recovery from injury. We investigated whether apoE deficiency reduces the healing effect of alanyl-glutamine (Ala-Gln) treatment, a recognized gut-trophic nutrient, during tissue recovery after 5-FU-induced intestinal mucositis. APOE-knockout (APOE{sup -/-}) and wild-type (APOE{sup +/+}) C57BL6J male and female mice (N=86) were given either Ala-Gln (100 mM) or phosphate buffered saline (PBS) by gavage 3 days before and 5 days after a 5-fluorouracil (5-FU) challenge (450 mg/kg, via intraperitoneal injection). Mouse body weight was monitored daily. The 5-FU cytotoxic effect was evaluated by leukometry. Intestinal villus height, villus/crypt ratio, and villin expression were monitored to assess recovery of the intestinal absorptive surface area. Crypt length, mitotic, apoptotic, and necrotic crypt indexes, and quantitative real-time PCR for insulin-like growth factor-1 (IGF-1) and B-cell lymphoma 2 (Bcl-2) intestinal mRNA transcripts were used to evaluate intestinal epithelial cell turnover. 5-FU challenge caused significant weight loss and leukopenia (P<0.001) in both mouse strains, which was not improved by Ala-Gln. Villus blunting, crypt hyperplasia, and reduced villus/crypt ratio (P<0.05) were found in all 5-FU-challenged mice but not in PBS controls. Ala-Gln improved villus/crypt ratio, crypt length and mitotic index in all challenged mice, compared with PBS controls. Ala-Gln improved villus height only in APOE{sup -/-} mice. Crypt cell apoptosis and necrotic scores were increased in all mice challenged by 5-FU, compared with untreated controls. Those scores were significantly lower in Ala-Gln-treated APOE{sup +/+} mice than in controls. Bcl-2 and IGF-1 mRNA transcripts were reduced only in the APOE{sup -/-}-challenged mice. Altogether our findings suggest APOE-independent Ala-Gln regenerative effects after 5-FU

  1. Alanyl-glutamine attenuates 5-fluorouracil-induced intestinal mucositis in apolipoprotein E-deficient mice

    International Nuclear Information System (INIS)

    Araújo, C.V.; Lazzarotto, C.R.; Aquino, C.C.; Figueiredo, I.L.; Costa, T.B.; Oliveira Alves, L.A. de; Ribeiro, R.A.; Bertolini, L.R.; Lima, A.A.M.; Brito, G.A.C.; Oriá, R.B.

    2015-01-01

    Apolipoprotein E (APOE=gene, apoE=protein) is a known factor regulating the inflammatory response that may have regenerative effects during tissue recovery from injury. We investigated whether apoE deficiency reduces the healing effect of alanyl-glutamine (Ala-Gln) treatment, a recognized gut-trophic nutrient, during tissue recovery after 5-FU-induced intestinal mucositis. APOE-knockout (APOE -/- ) and wild-type (APOE +/+ ) C57BL6J male and female mice (N=86) were given either Ala-Gln (100 mM) or phosphate buffered saline (PBS) by gavage 3 days before and 5 days after a 5-fluorouracil (5-FU) challenge (450 mg/kg, via intraperitoneal injection). Mouse body weight was monitored daily. The 5-FU cytotoxic effect was evaluated by leukometry. Intestinal villus height, villus/crypt ratio, and villin expression were monitored to assess recovery of the intestinal absorptive surface area. Crypt length, mitotic, apoptotic, and necrotic crypt indexes, and quantitative real-time PCR for insulin-like growth factor-1 (IGF-1) and B-cell lymphoma 2 (Bcl-2) intestinal mRNA transcripts were used to evaluate intestinal epithelial cell turnover. 5-FU challenge caused significant weight loss and leukopenia (P<0.001) in both mouse strains, which was not improved by Ala-Gln. Villus blunting, crypt hyperplasia, and reduced villus/crypt ratio (P<0.05) were found in all 5-FU-challenged mice but not in PBS controls. Ala-Gln improved villus/crypt ratio, crypt length and mitotic index in all challenged mice, compared with PBS controls. Ala-Gln improved villus height only in APOE -/- mice. Crypt cell apoptosis and necrotic scores were increased in all mice challenged by 5-FU, compared with untreated controls. Those scores were significantly lower in Ala-Gln-treated APOE +/+ mice than in controls. Bcl-2 and IGF-1 mRNA transcripts were reduced only in the APOE -/- -challenged mice. Altogether our findings suggest APOE-independent Ala-Gln regenerative effects after 5-FU challenge

  2. Progressive Retinal Degeneration and Accumulation of Autofluorescent Lipopigments in Progranulin Deficient Mice

    Science.gov (United States)

    Hafler, Brian P.; Klein, Zoe A.; Zhou, Z. Jimmy; Strittmatter, Stephen M.

    2014-01-01

    Prior investigations have shown that patients with neuronal ceroid lipofuscinosis (NCL) develop neurodegeneration characterized by vision loss, motor dysfunction, seizures, and often early death. Neuropathological analysis of patients with NCL shows accumulation of intracellular autofluorescent storage material, lipopigment, throughout neurons in the central nervous system including in the retina. A recent study of a sibling pair with adult onset NCL and retinal degeneration showed linkage to the region of the progranulin (GRN) locus and a homozygous mutation was demonstrated in GRN. In particular, the sibling pair with a mutation in GRN developed retinal degeneration and optic atrophy. This locus for this form of adult onset neuronal ceroid lipofuscinosis was designated neuronal ceroid lipofuscinosis-11 (CLN11). Based on these clinical observations, we wished to determine whether Grn-null mice develop accumulation of autofluorescent particles and retinal degeneration. Retinas of both wild-type and Progranulin deficient mice were examined by immunostaining and autofluorescence. Accumulation of autofluorescent material was present in Progranulin deficient mice at 12 months. Degeneration of multiple classes of neurons including photoreceptors and retinal ganglion cells was noted in mice at 12 and 18 months. Our data shows that Grn−/− mice develop degenerative pathology similar to features of human CLN11. PMID:25234724

  3. Abnormalities in osteoclastogenesis and decreased tumorigenesis in mice deficient for ovarian cancer G protein-coupled receptor 1.

    Directory of Open Access Journals (Sweden)

    Hui Li

    2009-05-01

    Full Text Available Ovarian cancer G protein-coupled receptor 1 (OGR1 has been shown to be a proton sensing receptor in vitro. We have shown that OGR1 functions as a tumor metastasis suppressor gene when it is over-expressed in human prostate cancer cells in vivo. To examine the physiological functions of OGR1, we generated conditional OGR1 deficient mice by homologous recombination. OGR1 deficient mice were viable and upon gross-inspection appeared normal. Consistent with in vitro studies showing that OGR1 is involved in osteoclastogenesis, reduced osteoclasts were detected in OGR1 deficient mice. A pH-dependent osteoclasts survival effect was also observed. However, overall abnormality in the bones of these animals was not observed. In addition, melanoma cell tumorigenesis was significantly inhibited in OGR1 deficient mice. OGR1 deficient mice in the mixed background produced significantly less peritoneal macrophages when stimulated with thioglycolate. These macrophages also showed altered extracellular signal-regulated kinases (ERK activation and nitric oxide (NO production in response to lipopolysaccharide. OGR1-dependent pH responses assessed by cAMP production and cell survival in macrophages or brown fat cells were not observed, presumably due to the presence of other proton sensing receptors in these cells. Our results indicate that OGR1's role in osteoclastogenesis is not strong enough to affect overall bone development and its role in tumorigenesis warrants further investigation. The mice generated can be potentially used for several disease models, including cancers or osteoclast-related diseases.

  4. Colonic lesions, cytokine profiles, and gut microbiota in plasminogen-deficient mice

    DEFF Research Database (Denmark)

    Vestergaard, Bill; Krych, Lukasz; Lund, Leif R.

    2015-01-01

    Plasminogen-deficient (FVB/NPan-plg(tm1Jld), plg(tm1Jld)) mice, which are widely used as a wound-healing model, are prone to spontaneous rectal prolapses. The aims of this study were 1) to evaluate the fecal microbiome of plg(tm1Jld) mice for features that might contribute to the development...... the composition of the gut microbiota, and none of the clinical or biochemical parameters correlated with the gut microbiota composition....

  5. Hypothalamic growth hormone receptor (GHR controls hepatic glucose production in nutrient-sensing leptin receptor (LepRb expressing neurons

    Directory of Open Access Journals (Sweden)

    Gillian Cady

    2017-05-01

    Full Text Available Objective: The GH/IGF-1 axis has important roles in growth and metabolism. GH and GH receptor (GHR are active in the central nervous system (CNS and are crucial in regulating several aspects of metabolism. In the hypothalamus, there is a high abundance of GH-responsive cells, but the role of GH signaling in hypothalamic neurons is unknown. Previous work has demonstrated that the Ghr gene is highly expressed in LepRb neurons. Given that leptin is a key regulator of energy balance by acting on leptin receptor (LepRb-expressing neurons, we tested the hypothesis that LepRb neurons represent an important site for GHR signaling to control body homeostasis. Methods: To determine the importance of GHR signaling in LepRb neurons, we utilized Cre/loxP technology to ablate GHR expression in LepRb neurons (LeprEYFPΔGHR. The mice were generated by crossing the Leprcre on the cre-inducible ROSA26-EYFP mice to GHRL/L mice. Parameters of body composition and glucose homeostasis were evaluated. Results: Our results demonstrate that the sites with GHR and LepRb co-expression include ARH, DMH, and LHA neurons. Leptin action was not altered in LeprEYFPΔGHR mice; however, GH-induced pStat5-IR in LepRb neurons was significantly reduced in these mice. Serum IGF-1 and GH levels were unaltered, and we found no evidence that GHR signaling regulates food intake and body weight in LepRb neurons. In contrast, diminished GHR signaling in LepRb neurons impaired hepatic insulin sensitivity and peripheral lipid metabolism. This was paralleled with a failure to suppress expression of the gluconeogenic genes and impaired hepatic insulin signaling in LeprEYFPΔGHR mice. Conclusion: These findings suggest the existence of GHR-leptin neurocircuitry that plays an important role in the GHR-mediated regulation of glucose metabolism irrespective of feeding. Keywords: Growth hormone receptor, Hypothalamus, Leptin receptor, Glucose production, Liver

  6. Impaired Latent Inhibition in GDNF-Deficient Mice Exposed to Chronic Stress

    Directory of Open Access Journals (Sweden)

    Mona Buhusi

    2017-10-01

    Full Text Available Increased reactivity to stress is maladaptive and linked to abnormal behaviors and psychopathology. Chronic unpredictable stress (CUS alters catecholaminergic neurotransmission and remodels neuronal circuits involved in learning, attention and decision making. Glial-derived neurotrophic factor (GDNF is essential for the physiology and survival of dopaminergic neurons in substantia nigra and of noradrenergic neurons in the locus coeruleus. Up-regulation of GDNF expression during stress is linked to resilience; on the other hand, the inability to up-regulate GDNF in response to stress, as a result of either genetic or epigenetic modifications, induces behavioral alterations. For example, GDNF-deficient mice exposed to chronic stress exhibit alterations of executive function, such as increased temporal discounting. Here we investigated the effects of CUS on latent inhibition (LI, a measure of selective attention and learning, in GDNF-heterozygous (HET mice and their wild-type (WT littermate controls. No differences in LI were found between GDNF HET and WT mice under baseline experimental conditions. However, following CUS, GDNF-deficient mice failed to express LI. Moreover, stressed GDNF-HET mice, but not their WT controls, showed decreased neuronal activation (number of c-Fos positive neurons in the nucleus accumbens shell and increased activation in the nucleus accumbens core, both key regions in the expression of LI. Our results add LI to the list of behaviors affected by chronic stress and support a role for GDNF deficits in stress-induced pathological behaviors relevant to schizophrenia and other psychiatric disorders.

  7. Mcph1-deficient mice reveal a role for MCPH1 in otitis media.

    Directory of Open Access Journals (Sweden)

    Jing Chen

    Full Text Available Otitis media is a common reason for hearing loss, especially in children. Otitis media is a multifactorial disease and environmental factors, anatomic dysmorphology and genetic predisposition can all contribute to its pathogenesis. However, the reasons for the variable susceptibility to otitis media are elusive. MCPH1 mutations cause primary microcephaly in humans. So far, no hearing impairment has been reported either in the MCPH1 patients or mouse models with Mcph1 deficiency. In this study, Mcph1-deficient (Mcph1(tm1a (/tm1a mice were produced using embryonic stem cells with a targeted mutation by the Sanger Institute's Mouse Genetics Project. Auditory brainstem response measurements revealed that Mcph1(tm1a (/tm1a mice had mild to moderate hearing impairment with around 70% penetrance. We found otitis media with effusion in the hearing-impaired Mcph1(tm1a (/tm1a mice by anatomic and histological examinations. Expression of Mcph1 in the epithelial cells of middle ear cavities supported its involvement in the development of otitis media. Other defects of Mcph1(tm1a (/tm1a mice included small skull sizes, increased micronuclei in red blood cells, increased B cells and ocular abnormalities. These findings not only recapitulated the defects found in other Mcph1-deficient mice or MCPH1 patients, but also revealed an unexpected phenotype, otitis media with hearing impairment, which suggests Mcph1 is a new gene underlying genetic predisposition to otitis media.

  8. Upregulation of miR21 and repression of Grhl3 by leptin mediates sinusoidal endothelial injury in experimental nonalcoholic steatohepatitis.

    Directory of Open Access Journals (Sweden)

    Sahar Pourhoseini

    Full Text Available Sinusoidal endothelial dysfunction (SED has been found to be an early event in nonalcoholic steatohepatitis (NASH progression but the molecular mechanisms underlying its causation remains elusive. We hypothesized that adipokine leptin worsens sinusoidal injury by decreasing functionally active nitric oxide synthase 3 (NOS3 via miR21. Using rodent models of NASH, and transgenic mice lacking leptin and leptin receptor, results showed that hyperleptinemia caused a 4-5 fold upregulation of hepatic miR21 as assessed by qRTPCR. The upregulation of miR21 led to a time-dependent repression of its target protein Grhl3 levels as shown by western blot analyses. NOS3-p/NOS3 ratio which is controlled by Grhl3 was significantly decreased in NASH models. SED markers ICAM-1, VEGFR-2, and E-selectin as assessed by immunofluorescence microscopy were significantly up regulated in the progressive phases of NASH. Lack of leptin or its receptor in vivo, reversed the upregulation of miR21 and restored the levels of Grhl3 and NOS3-p/NOS3 ratio coupled with decreased SED dysfunction markers. Interestingly, leptin supplementation in mice lacking leptin, significantly enhanced miR21 levels, decreased Grhl3 repression and NOS3 phosphorylation. Leptin supplementation in isolated primary endothelial cells, Kupffer cells and stellate cells showed increased mir21 expression in stellate cells while sinusoidal injury was significantly higher in all cell types. Finally miR21 KO mice showed increased NOS3-p/NOS3 ratio and reversed SED markers in the rodent models of NASH. The experimental results described here show a close association of leptin-induced miR21 in aiding sinusoidal injury in NASH.

  9. CDKL5 deficiency entails sleep apneas in mice.

    Science.gov (United States)

    Lo Martire, Viviana; Alvente, Sara; Bastianini, Stefano; Berteotti, Chiara; Silvani, Alessandro; Valli, Alice; Viggiano, Rocchina; Ciani, Elisabetta; Zoccoli, Giovanna

    2017-08-01

    A recently discovered neurodevelopmental disorder caused by the mutation of the cyclin-dependent kinase-like 5 gene (CDKL5) entails complex autistic-like behaviours similar to Rett syndrome, but its impact upon physiological functions remains largely unexplored. Sleep-disordered breathing is common and potentially life-threatening in patients with Rett syndrome; however, evidence is limited in children with CDKL5 disorder, and is lacking altogether in adults. The aim of this study was to test whether the breathing pattern during sleep differs between adult Cdkl5 knockout (Cdkl5-KO) and wild-type (WT) mice. Using whole-body plethysmography, sleep and breathing were recorded non-invasively for 8 h during the light period. Sleep apneas occurred more frequently in Cdkl5-KO than in WT mice. A receiver operating characteristic (ROC) analysis discriminated Cdkl5-KO significantly from WT mice based on sleep apnea occurrence. These data demonstrate that sleep apneas are a core feature of CDKL5 disorder and a respiratory biomarker of CDKL5 deficiency in mice, and suggest that sleep-disordered breathing should be evaluated routinely in CDKL5 patients. © 2017 European Sleep Research Society.

  10. The Beneficial Effects of Leptin on REM Sleep Deprivation-Induced Cognitive Deficits in Mice

    Science.gov (United States)

    Chang, Hsiao-Fu; Su, Chun-Lin; Chang, Chih-Hua; Chen, Yu-Wen; Gean, Po-Wu

    2013-01-01

    Leptin, a 167 amino acid peptide, is synthesized predominantly in the adipose tissues and plays a key role in the regulation of food intake and body weight. Recent studies indicate that leptin receptor is expressed with high levels in many brain regions that may regulate synaptic plasticity. Here we show that deprivation of rapid eye movement…

  11. GRAF1 deficiency blunts sarcolemmal injury repair and exacerbates cardiac and skeletal muscle pathology in dystrophin-deficient mice.

    Science.gov (United States)

    Lenhart, Kaitlin C; O'Neill, Thomas J; Cheng, Zhaokang; Dee, Rachel; Demonbreun, Alexis R; Li, Jianbin; Xiao, Xiao; McNally, Elizabeth M; Mack, Christopher P; Taylor, Joan M

    2015-01-01

    The plasma membranes of striated muscle cells are particularly susceptible to rupture as they endure significant mechanical stress and strain during muscle contraction, and studies have shown that defects in membrane repair can contribute to the progression of muscular dystrophy. The synaptotagmin-related protein, dysferlin, has been implicated in mediating rapid membrane repair through its ability to direct intracellular vesicles to sites of membrane injury. However, further work is required to identify the precise molecular mechanisms that govern dysferlin targeting and membrane repair. We previously showed that the bin-amphiphysin-Rvs (BAR)-pleckstrin homology (PH) domain containing Rho-GAP GTPase regulator associated with focal adhesion kinase-1 (GRAF1) was dynamically recruited to the tips of fusing myoblasts wherein it promoted membrane merging by facilitating ferlin-dependent capturing of intracellular vesicles. Because acute membrane repair responses involve similar vesicle trafficking complexes/events and because our prior studies in GRAF1-deficient tadpoles revealed a putative role for GRAF1 in maintaining muscle membrane integrity, we postulated that GRAF1 might also play an important role in facilitating dysferlin-dependent plasma membrane repair. We used an in vitro laser-injury model to test whether GRAF1 was necessary for efficient muscle membrane repair. We also generated dystrophin/GRAF1 doubledeficient mice by breeding mdx mice with GRAF1 hypomorphic mice. Evans blue dye uptake and extensive morphometric analyses were used to assess sarcolemmal integrity and related pathologies in cardiac and skeletal muscles isolated from these mice. Herein, we show that GRAF1 is dynamically recruited to damaged skeletal and cardiac muscle plasma membranes and that GRAF1-depleted muscle cells have reduced membrane healing abilities. Moreover, we show that dystrophin depletion exacerbated muscle damage in GRAF1-deficient mice and that mice with dystrophin/GRAF1

  12. Consumption of a low-carbohydrate and high-fat diet (the ketogenic diet) exaggerates biotin deficiency in mice.

    Science.gov (United States)

    Yuasa, Masahiro; Matsui, Tomoyoshi; Ando, Saori; Ishii, Yoshie; Sawamura, Hiromi; Ebara, Shuhei; Watanabe, Toshiaki

    2013-10-01

    Biotin is a water-soluble vitamin that acts as a cofactor for several carboxylases. The ketogenic diet, a low-carbohydrate, high-fat diet, is used to treat drug-resistant epilepsy and promote weight loss. In Japan, the infant version of the ketogenic diet is known as the "ketone formula." However, as the special infant formulas used in Japan, including the ketone formula, do not contain sufficient amounts of biotin, biotin deficiency can develop in infants who consume the ketone formula. Therefore, the aim of this study was to evaluate the effects of the ketogenic diet on biotin status in mice. Male mice (N = 32) were divided into the following groups: control diet group, biotin-deficient (BD) diet group, ketogenic control diet group, and ketogenic biotin-deficient (KBD) diet group. Eight mice were used in each group. At 9 wk, the typical symptoms of biotin deficiency such as hair loss and dermatitis had only developed in the KBD diet group. The total protein expression level of biotin-dependent carboxylases and the total tissue biotin content were significantly decreased in the KBD and BD diet groups. However, these changes were more severe in the KBD diet group. These findings demonstrated that the ketogenic diet increases biotin bioavailability and consumption, and hence, promotes energy production by gluconeogenesis and branched-chain amino acid metabolism, which results in exaggerated biotin deficiency in biotin-deficient mice. Therefore, biotin supplementation is important for mice that consume the ketogenic diet. It is suggested that individuals that consume the ketogenic diet have an increased biotin requirement. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Aldose reductase deficiency protects from autoimmune- and endotoxin-induced uveitis in mice.

    Science.gov (United States)

    Yadav, Umesh C S; Shoeb, Mohammed; Srivastava, Satish K; Ramana, Kota V

    2011-10-17

    To investigate the effect of aldose reductase (AR) deficiency in protecting the chronic experimental autoimmune (EAU) and acute endotoxin-induced uveitis (EIU) in c57BL/6 mice. The WT and AR-null (ARKO) mice were immunized with human interphotoreceptor retinoid-binding peptide (hIRPB-1-20), to induce EAU, or were injected subcutaneously with lipopolysaccharide (LPS; 100 μg) to induce EIU. The mice were killed on day 21 for EAU and at 24 hours for EIU, when the disease was at its peak, and the eyes were immediately enucleated for histologic and biochemical studies. Spleen-derived T-lymphocytes were used to study the antigen-specific immune response in vitro and in vivo. In WT-EAU mice, severe damage to the retinal wall, especially to the photoreceptor layer was observed, corresponding to a pathologic score of ∼2, which was significantly prevented in the ARKO or AR inhibitor-treated mice. The levels of cytokines and chemokines increased markedly in the whole-eye homogenates of WT-EAU mice, but not in ARKO-EAU mice. Further, expression of inflammatory marker proteins such as inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, tumor necrosis factor (TNF)-α, and vascular cell adhesion molecule (VCAM)-1 was increased in the WT-EIU mouse eyes but not in the ARKO-EIU eyes. The T cells proliferated vigorously when exposed to the hIRPB antigen in vitro and secreted various cytokines and chemokines, which were significantly inhibited in the T cells isolated from the ARKO mice. These findings suggest that AR-deficiency/inhibition protects against acute as well as chronic forms of ocular inflammatory complications such as uveitis.

  14. Glutamic acid ameliorates estrogen deficiency-induced menopausal-like symptoms in ovariectomized mice.

    Science.gov (United States)

    Han, Na-Ra; Kim, Hee-Yun; Yang, Woong Mo; Jeong, Hyun-Ja; Kim, Hyung-Min

    2015-09-01

    Some amino acids are considered alternative therapies for improving menopausal symptoms. Glutamic acid (GA), which is abundant in meats, fish, and protein-rich plant foods, is known to be a neurotransmitter or precursor of γ-aminobutyric acid. Although it is unclear if GA functions in menopausal symptoms, we hypothesized that GA would attenuate estrogen deficiency-induced menopausal symptoms. The objective to test our hypothesis was to examine an estrogenic effect of GA in ovariectomized (OVX) mice, estrogen receptor (ER)-positive human osteoblast-like MG-63 cells, and ER-positive human breast cancer MCF-7 cells. The results demonstrated that administration with GA to mice suppressed body weight gain and vaginal atrophy when compared with the OVX mice. A microcomputed tomographic analysis of the trabecular bone showed increases in bone mineral density, trabecular number, and connectivity density as well as a significant decrease in total porosity of the OVX mice treated with GA. In addition, GA increased serum levels of alkaline phosphatase and estrogen compared with the OVX mice. Furthermore, GA induced proliferation and increased ER-β messenger RNA (mRNA) expression, estrogen response element (ERE) activity, extracellular signal-regulated kinase phosphorylation, and alkaline phosphatase activity in MG-63 cells. In MCF-7 cells, GA also increased proliferation, Ki-67 mRNA expression, ER-β mRNA expression, and ERE activity. Estrogen response element activity increased by GA was inhibited by an estrogen antagonist. Taken together, our data demonstrated that GA has estrogenic and osteogenic activities in OVX mice, MG-63 cells, and MCF-7 cells. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Citrullus lanatus `Sentinel' (Watermelon) Extract Reduces Atherosclerosis in LDL Receptor Deficient Mice

    Science.gov (United States)

    Poduri, Aruna; Rateri, Debra L.; Saha, Shubin K.; Saha, Sibu; Daugherty, Alan

    2012-01-01

    Watermelon (Citrullus lanatus or C. lanatus) has many potentially bioactive compounds including citrulline, which may influence atherosclerosis. In this study, we determined the effects of C. lanatus, provided as an extract of the cultivar `sentinel', on hypercholesterolemia-induced atherosclerosis in mice. Male LDL receptor deficient mice at 8 weeks old were given either C. lanatus `sentinel' extract (2% vol/vol; n=10) or a mixture of matching carbohydrates (2% vol/vol; n=8) as the control in drinking water, while fed a saturated fat-enriched diet for 12 weeks ad libitum. Mice consuming C. lanatus `sentinel' extract had significantly increased plasma citrulline concentrations. Systolic blood pressure was comparable between the two groups. Consumption of C. lanatus `sentinel' extract led to lower body weight and fat mass without influencing lean mass. There were no differences in food and water intake, and urine output between the two groups. C. lanatus `sentinel' extract administration decreased plasma cholesterol concentrations that were attributed to reductions of intermediate/low density lipoprotein cholesterol. Plasma concentrations of MCP-1 and IFN-γ were decreased and IL-10 increased in mice consuming C. lanatus `sentinel' extract. Intake of C. lanatus `sentinel' extract resulted in reductions of atherosclerosis in both aortic arch and thoracic regions. In conclusion, consumption of C. lanatus `sentinel' extract led to reduced body weight gain, decreased plasma cholesterol concentrations, improved homeostasis of pro- and anti-inflammatory cytokines, and attenuated development of atherosclerosis without affecting systolic blood pressure in hypercholesterolemic mice. PMID:22902326

  16. Rejection of class I MHC-deficient haemopoietic cells by irradiated MHC-matched mice

    International Nuclear Information System (INIS)

    Bix, M.; Nanshih Liao; Raulet, D.; Zijlstra, M.; Loring, J.; Jaenisch, R.

    1991-01-01

    Irradiated MHC-heterozygous mice often reject bone marrow cells transplanted from one of the homozygous parental strains, a phenomenon ('hybrid resistance') that appears to violate the laws of transplantation. Rejection of parental and allogeneic marrow cells also differs from conventional T cell-mediated rejection mechanisms as it is effected by NK1.1 + cells. To account for the unusual specificity of bone marrow rejection, it has been proposed that NK1.1 + cells destroy marrow cells that fail to express the full complement of self MHC class I (MHC-I) molecules. We show here that NK1.1 + cells in normal mice reject haemopoietic transplants from mice that are deficient for normal cell-surface MHC-I expression because of a targeted mutation in the β 2 -microglobulin gene. These findings demonstrate that deficient expression of MHC-I molecules renders marrow cells susceptible to rejection. (author)

  17. Ablation of neurons expressing melanin-concentrating hormone (MCH) in adult mice improves glucose tolerance independent of MCH signaling.

    Science.gov (United States)

    Whiddon, Benjamin B; Palmiter, Richard D

    2013-01-30

    Melanin-concentrating hormone (MCH)-expressing neurons have been ascribed many roles based on studies of MCH-deficient mice. However, MCH neurons express other neurotransmitters, including GABA, nesfatin, and cocaine-amphetamine-regulated transcript. The importance of these other signaling molecules made by MCH neurons remains incompletely characterized. To determine the roles of MCH neurons in vivo, we targeted expression of the human diphtheria toxin receptor (DTR) to the gene for MCH (Pmch). Within 2 weeks of diphtheria toxin injection, heterozygous Pmch(DTR/+) mice lost 98% of their MCH neurons. These mice became lean but ate normally and were hyperactive, especially during a fast. They also responded abnormally to psychostimulants. For these phenotypes, ablation of MCH neurons recapitulated knock-out of MCH, so MCH appears to be the critical neuromodulator released by these neurons. In contrast, MCH-neuron-ablated mice showed improved glucose tolerance when compared with MCH-deficient mutant mice and wild-type mice. We conclude that MCH neurons regulate glucose tolerance through signaling molecules other than MCH.

  18. Goldfish Leptin-AI and Leptin-AII: Function and Central Mechanism in Feeding Control

    Directory of Open Access Journals (Sweden)

    Ai-Fen Yan

    2016-05-01

    Full Text Available In mammals, leptin is a peripheral satiety factor that inhibits feeding by regulating a variety of appetite-related hormones in the brain. However, most of the previous studies examining leptin in fish feeding were performed with mammalian leptins, which share very low sequence homologies with fish leptins. To elucidate the function and mechanism of endogenous fish leptins in feeding regulation, recombinant goldfish leptin-AI and leptin-AII were expressed in methylotrophic yeast and purified by immobilized metal ion affinity chromatography (IMAC. By intraperitoneal (IP injection, both leptin-AI and leptin-AII were shown to inhibit the feeding behavior and to reduce the food consumption of goldfish in 2 h. In addition, co-treatment of leptin-AI or leptin-AII could block the feeding behavior and reduce the food consumption induced by neuropeptide Y (NPY injection. High levels of leptin receptor (lepR mRNA were detected in the hypothalamus, telencephalon, optic tectum and cerebellum of the goldfish brain. The appetite inhibitory effects of leptins were mediated by downregulating the mRNA levels of orexigenic NPY, agouti-related peptide (AgRP and orexin and upregulating the mRNA levels of anorexigenic cocaine-amphetamine-regulated transcript (CART, cholecystokinin (CCK, melanin-concentrating hormone (MCH and proopiomelanocortin (POMC in different areas of the goldfish brain. Our study, as a whole, provides new insights into the functions and mechanisms of leptins in appetite control in a fish model.

  19. Sex differences in obesity development in pair-fed neuronal lipoprotein lipase deficient mice

    Directory of Open Access Journals (Sweden)

    Hong Wang

    2016-10-01

    Full Text Available Objective: Compared to men, postmenopausal women suffer from a disproportionate burden of many co-morbidities associated with obesity, e.g. cardiovascular disease, cancer, and dementia. The underlying mechanism for this sex difference is not well understood but is believed to relate to absence of the protective effect of estrogen through the action of estrogen receptor alpha (ERα in the central nervous system. With the recently developed neuron-specific lipoprotein lipase deficient mice (NEXLPL−/− (Wang et al., Cell Metabolism, 2011 [15], we set to explore the possible role of lipid sensing in sex differences in obesity development. Methods: Both male and female NEXLPL−/− mice and littermate WT controls were subjected to pair feeding (pf where daily food amount given was adjusted according to body weight to match the food intake of ad libitum (ad fed control WT mice. Food intake and body weight were measured daily, and pair feeding was maintained to 42 wk in male mice and to 38 wk in female mice. Various brain regions of the mice were harvested, and ERα gene expression was examined in both male and female NEXLPL−/− and WT control mice under both ad- and pf-fed conditions. Results: Although both male and female NEXLPL−/− mice developed obesity similarly on standard chow, male NEXLPL−/− mice still developed obesity under with pair feeding, but on a much delayed time course, while female NEXLPL−/− mice were protected from extra body weight and fat mass gain compared to pair-fed WT control mice. Pair feeding alone induced extra fat mass gain in both male and female WT mice, and this was mostly driven by the reduction in physical activity. LPL deficiency resulted in an increase in ERα mRNA in the hypothalamus of ad-fed female mice, while pair feeding alone also resulted in an increase of ERα in both female WT control and NEXLPL−/− mice. The effect on increasing ERα by pair feeding and LPL deficiency was additive in

  20. Sida rhomboidea. Roxb leaf extract down-regulates expression of PPARγ2 and leptin genes in high fat diet fed C57BL/6J Mice and retards in vitro 3T3L1 pre-adipocyte differentiation.

    Science.gov (United States)

    Thounaojam, Menaka C; Jadeja, Ravirajsinh N; Ramani, Umed V; Devkar, Ranjitsinh V; Ramachandran, A V

    2011-01-01

    Sida rhomboidea. Roxb leaf extract (SRLE) is being used by the populace of North-East India to alleviate symptoms of diabetes and obesity. We have previously reported its hypolipidemic and anti-diabetic properties. In this study, we report the effect of SRLE on (i) in vivo modulation of genes controlling high fat diet (HFD) induced obesity and (ii) in vitro 3T3L1 pre-adipocyte differentiation and leptin release. Supplementation with SRLE significantly prevented HFD induced increment in bodyweight, plasma lipids and leptin, visceral adiposity and adipocyte hypertrophy. Also, SRLE supplementation reduced food intake, down regulated PPARγ2, SREBP1c, FAS and LEP expressions and up-regulated CPT-1 in epididymal adipose tissue compared to obese mice. In vitro adipogenesis of 3T3L1 pre-adipocytes was significantly retarded in the presence of SRLE extract. Also decreased triglyceride accumulation, leptin release and glyceraldehyde-3-Phosphate dehydrogenase activity along with higher glycerol release without significant alteration of viability of 3T3L1 pre-adipocytes, was recorded. Our findings suggest that prevention of HFD induced visceral adiposity is primarily by down regulation of PPARγ2 and leptin gene expression coupled with attenuation of food intake in C57BL/6J mice. SRLE induced prevention of pre-adipocytes differentiation, and leptin release further substantiated these findings and scientifically validates the potential application of SRLE as a therapeutic agent against obesity.

  1. Primary coenzyme Q deficiency in Pdss2 mutant mice causes isolated renal disease.

    Directory of Open Access Journals (Sweden)

    Min Peng

    2008-04-01

    Full Text Available Coenzyme Q (CoQ is an essential electron carrier in the respiratory chain whose deficiency has been implicated in a wide variety of human mitochondrial disease manifestations. Its multi-step biosynthesis involves production of polyisoprenoid diphosphate in a reaction that requires the enzymes be encoded by PDSS1 and PDSS2. Homozygous mutations in either of these genes, in humans, lead to severe neuromuscular disease, with nephrotic syndrome seen in PDSS2 deficiency. We now show that a presumed autoimmune kidney disease in mice with the missense Pdss2(kd/kd genotype can be attributed to a mitochondrial CoQ biosynthetic defect. Levels of CoQ9 and CoQ10 in kidney homogenates from B6.Pdss2(kd/kd mutants were significantly lower than those in B6 control mice. Disease manifestations originate specifically in glomerular podocytes, as renal disease is seen in Podocin/cre,Pdss2(loxP/loxP knockout mice but not in conditional knockouts targeted to renal tubular epithelium, monocytes, or hepatocytes. Liver-conditional B6.Alb/cre,Pdss2(loxP/loxP knockout mice have no overt disease despite demonstration that their livers have undetectable CoQ9 levels, impaired respiratory capacity, and significantly altered intermediary metabolism as evidenced by transcriptional profiling and amino acid quantitation. These data suggest that disease manifestations of CoQ deficiency relate to tissue-specific respiratory capacity thresholds, with glomerular podocytes displaying the greatest sensitivity to Pdss2 impairment.

  2. Leptin and insulin responses to a four-day energy-deficient diet in men with different weight history.

    Science.gov (United States)

    Mars, M; de Graaf, C; van Rossum, C T M; de Groot, C P G M; Seidell, J C; Kok, F J

    2003-05-01

    To assess the leptin responses to a 4-day energy-restricted diet in men with different weight history; high retrospective weight gain was expected to be associated with a small decline in leptin. Changes in fasting leptin and insulin were measured during a 4-day controlled intervention, in which men with high retrospective weight gain and men who had stable weight consumed 35% of their estimated energy needs. A total of 44 healthy men (age: 31-52 y, BMI: 22.7-39.8 kg/m(2)) were recruited from a cohort study: 22 men who had gained weight (weight change >1 kg/y) and 22 men whose weight had remained stable (weight change +/-0.3 kg/y) between the first (1987-1991) and the second measurement (1993-1997) of the cohort study. The intervention study was carried out in 2001. After intervention, changes in fasting leptin levels were similar for both groups of retrospective weight gain: -2.2 microlU/ml (95% CI: -2.8; -1.7) and -2.4 microlU/ml (95% CI: -3.2; -1.7) respectively (P=0.69). Proportional changes in fasting leptin levels were different: -43.3% (95% CI: -47.8; -38.4) in the participants whose weight had remained stable (n=22) and -35.2% (95% CI: -42.4; -27.1) in those who had gained weight (n=22)(Pmen (n=18), in which the contrast in weight history was more pronounced than in the total group, did not show this difference. A higher proportional decrease in insulin levels was seen in men whose weight remained stable than in those who had gained weight: -35.4% (95% CI: -46.9; -21.3) and -12.8% (95% CI: -28.1; 5.7), respectively. The proportional decrease in leptin was positively associated with the proportional decrease in insulin (r=0.52; Pmen with retrospective weight gain, our study does not show convincing evidence that men who gained weight are less leptin responsive to changes in energy balance than those who were weight stable.

  3. Brain transcriptional responses to high-fat diet in Acads-deficient mice reveal energy sensing pathways.

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    Claudia Kruger

    Full Text Available How signals from fatty acid metabolism are translated into changes in food intake remains unclear. Previously we reported that mice with a genetic inactivation of Acads (acyl-coenzyme A dehydrogenase, short-chain, the enzyme responsible for mitochondrial beta-oxidation of C4-C6 short-chain fatty acids (SCFAs, shift consumption away from fat and toward carbohydrate when offered a choice between diets. In the current study, we sought to indentify candidate genes and pathways underlying the effects of SCFA oxidation deficiency on food intake in Acads-/- mice.We performed a transcriptional analysis of gene expression in brain tissue of Acads-/- and Acads+/+ mice fed either a high-fat (HF or low-fat (LF diet for 2 d. Ingenuity Pathway Analysis revealed three top-scoring pathways significantly modified by genotype or diet: oxidative phosphorylation, mitochondrial dysfunction, and CREB signaling in neurons. A comparison of statistically significant responses in HF Acads-/- vs. HF Acads+/+ (3917 and Acads+/+ HF vs. LF Acads+/+ (3879 revealed 2551 genes or approximately 65% in common between the two experimental comparisons. All but one of these genes were expressed in opposite direction with similar magnitude, demonstrating that HF-fed Acads-deficient mice display transcriptional responses that strongly resemble those of Acads+/+ mice fed LF diet. Intriguingly, genes involved in both AMP-kinase regulation and the neural control of food intake followed this pattern. Quantitative RT-PCR in hypothalamus confirmed the dysregulation of genes in these pathways. Western blotting showed an increase in hypothalamic AMP-kinase in Acads-/- mice and HF diet increased, a key protein in an energy-sensing cascade that responds to depletion of ATP.Our results suggest that the decreased beta-oxidation of short-chain fatty acids in Acads-deficient mice fed HF diet produces a state of energy deficiency in the brain and that AMP-kinase may be the cellular energy

  4. Leptin promotor mutations affect leptin levels and performance traits in dairy cows

    NARCIS (Netherlands)

    Liefers, S.C.; Pas, te M.F.W.; Veerkamp, R.F.; Platje, M.; Delavaud, C.; Chilliard, Y.; Lende, van der T.

    2005-01-01

    Leptin concentrations in body fluids and tissues undergo dynamic changes during the periparturient period. Polymorphisms in the leptin gene have been shown to be associated with differences in leptin concentration during late pregnancy but not during lactation. As the promoter of leptin regulates

  5. Cerebrospinal fluid hypocretin 1 deficiency, overweight, and metabolic dysregulation in patients with narcolepsy.

    Science.gov (United States)

    Heier, Mona S; Jansson, Tine S; Gautvik, Kaare M

    2011-12-15

    The possible relationship between cerebrospinal fluid (CSF) hypocretin and leptin levels, overweight, and association to risk factors for diabetes 2 in narcolepsy with cataplexy were compared to patients with idiopathic hypersomnia and controls. 26 patients with narcolepsy, cataplexy, and hypocretin deficiency; 23 patients with narcolepsy, cataplexy, and normal hypocretin values; 11 patients with idiopathic hypersomnia; and 43 controls. Body mass index (BMI), serum leptin, and HbA1C were measured in patients and controls; and CSF hypocretin 1 and leptin measured in all patients. Female and male patients with narcolepsy and hypocretin deficiency had the highest mean BMI (27.8 and 26.2, respectively), not statistically different from patients with narcolepsy and normal hypocretin or controls, but statistically higher than the patients with idiopathic hypersomnia (p 30) was increased in both narcolepsy groups. Serum and CSF leptin levels correlated positively to BMI in patients and controls, but not to CSF hypocretin concentrations. HbA1C was within normal levels and similar in all groups. The study confirms a moderate tendency to obesity (BMI > 30) and overweight in patients with narcolepsy and cataplexy. Obesity was not correlated to hypocretin deficiency or reduced serum or CSF leptin concentrations. We suggest that overweight and possible metabolic changes previously reported in narcolepsy, may be caused by other mechanisms.

  6. Baseline leptin and leptin reduction predict improvements in metabolic variables and long-term fat loss in obese children and adolescents: a prospective study of an inpatient weight-loss program

    NARCIS (Netherlands)

    Murer, S.B.; Knopfli, B.H.; Aeberli, I.; Jung, A.; Wildhaber, J.; Wildhaber-Brooks, J.; Zimmermann, M.B.

    2011-01-01

    Background: It is unclear whether high plasma leptin in obese individuals represents leptin resistance or whether individuals with marked reductions in leptin concentrations in response to weight loss may be at greater risk of regaining weight. Moreover, whether changes in leptin predict metabolic

  7. Circadian rhythms and food anticipatory behavior in Wfs1-deficient mice

    DEFF Research Database (Denmark)

    Luuk, Hendrik; Fahrenkrug, Jan; Hannibal, Jens

    2012-01-01

    in significantly lower body weight and reduced wheel-running activity. Circadian rhythmicity of behavior was normal in Wfs1-deficient mice under ad libitum feeding apart from elongated free-running period in constant light. The amount of food anticipatory activity induced by restricted feeding...

  8. Sustained beta-cell dysfunction but normalized islet mass in aged thrombospondin-1 deficient mice.

    Directory of Open Access Journals (Sweden)

    Carl Johan Drott

    Full Text Available Pancreatic islet endothelial cells have in recent years been shown to support beta-cell mass and function by paracrine interactions. Recently, we identified an islets endothelial-specific glycoprotein, thrombospondin-1 (TSP-1, that showed to be of importance for islet angiogenesis and beta-cell function in young mice. The present study aimed to investigate long-term consequences for islet morphology and beta-cell function of TSP-1 deficiency. Islet and beta-cell mass were observed increased at 10-12 weeks of age in TSP-1 deficient mice, but were normalized before 16 weeks of age when compared to wild-type controls. Islet vascularity was normal in 10-12 and 16-week-old TSP-1 deficient animals, whereas islets of one-year-old animals lacking TSP-1 were hypervascular. Beta-cell dysfunction in TSP-1 deficient animals was present at similar magnitudes between 10-12 and 52 weeks of age, as evaluated by glucose tolerance tests. The insulin secretion capacity in vivo of islets in one-year-old TSP-1 deficient animals was only ∼15% of that in wild-type animals. Using a transplantation model, we reconstituted TSP-1 in adult TSP-deficient islets. In contrast to neonatal TSP-1 deficient islets that we previously reported to regain function after TSP-1 reconstitution, adult islets failed to recover. We conclude that TSP-1 deficiency in islets causes changing vascular and endocrine morphological alterations postnatally, but is coupled to a chronic beta-cell dysfunction. The beta-cell dysfunction induced by TSP-1 deficiency is irreversible if not substituted early in life.

  9. CMKLR1 deficiency maintains ovarian steroid production in mice treated chronically with dihydrotestosterone.

    Science.gov (United States)

    Tang, Mi; Huang, Chen; Wang, Yu-Fei; Ren, Pei-Gen; Chen, Li; Xiao, Tian-Xia; Wang, Bao-Bei; Pan, Yan-Fei; Tsang, Benjamin K; Zabel, Brian A; Ma, Bao-Hua; Zhao, Hui-Ying; Zhang, Jian V

    2016-02-19

    Elevated serum chemerin levels correlate with increased severity of polycystic ovary syndrome (PCOS). However, the role of CMKLR1 signaling in ovarian biology under conditions of excess DHT remains unclear. In this study we compared the effects of continuous 90-day high dose DHT exposure (83.3 □g/day) on wild type and CMKLR1-deficient mice. DHT induced PCOS-like clinical signs in wild type mice as well as significant changes in the expression of hormone receptors, steroid synthesis enzymes, and BMPs and their receptors. In contrast, CMKLR1-deficient mice significantly attenuated DHT-induced clinical signs of PCOS and alterations in ovarian gene expression. To determine whether the BMP4 signaling pathway was involved in the pathogenic effects of CMKLR1 signaling in DHT-induced ovarian steroidogenesis, antral follicles were isolated from wild type and CMKLR1 knockout (KO) mice and treated in vitro with combinations of hCG, DHT, and BMP4 inhibitors. BMP4 inhibition attenuated the induction effects of hCG and DHT on estrogen and progesterone secretion in CMKLR1 KO mice, but not in WT mice, implicating the BMP4 signaling pathway in the CMKLR1-dependent response to DHT. In conclusion, CMKLR1 gene deletion attenuates the effects of chronic DHT treatment on ovarian function in experimental PCOS, likely via BMP4 signaling.

  10. Dietary magnesium deficiency affects gut microbiota and anxiety-like behaviour in C57BL/6N mice.

    Science.gov (United States)

    Pyndt Jørgensen, Bettina; Winther, Gudrun; Kihl, Pernille; Nielsen, Dennis S; Wegener, Gregers; Hansen, Axel K; Sørensen, Dorte B

    2015-10-01

    Magnesium deficiency has been associated with anxiety in humans, and rodent studies have demonstrated the gut microbiota to impact behaviour. We investigated the impact of 6 weeks of dietary magnesium deficiency on gut microbiota composition and anxiety-like behaviour and whether there was a link between the two. A total of 20 C57BL/6 mice, fed either a standard diet or a magnesium-deficient diet for 6 weeks, were tested using the light-dark box anxiety test. Gut microbiota composition was analysed by denaturation gradient gel electrophoresis. We demonstrated that the gut microbiota composition correlated significantly with the behaviour of dietary unchallenged mice. A magnesium-deficient diet altered the gut microbiota, and was associated with altered anxiety-like behaviour, measured by decreased latency to enter the light box. Magnesium deficiency altered behavior. The duration of magnesium deficiency is suggested to influence behaviour in the evaluated test.

  11. Pleckstrin homology-like domain family A, member 3 (PHLDA3 deficiency improves islets engraftment through the suppression of hypoxic damage.

    Directory of Open Access Journals (Sweden)

    Naoaki Sakata

    Full Text Available Islet transplantation is a useful cell replacement therapy that can restore the glycometabolic function of severe diabetic patients. It is known that many transplanted islets failed to engraft, and thus, new approaches for overcoming graft loss that may improve the outcome of future clinical islet transplantations are necessary. Pleckstrin homology-like domain family A, member 3 (PHLDA3 is a known suppressor of neuroendocrine tumorigenicity, yet deficiency of this gene increases islet proliferation, prevents islet apoptosis, and improves their insulin-releasing function without causing tumors. In this study, we examined the potential use of PHLDA3-deficient islets in transplantation. We observed that: 1 transplanting PHLDA3-deficient islets into diabetic mice significantly improved their glycometabolic condition, 2 the improved engraftment of PHLDA3-deficient islets resulted from increased cell survival during early transplantation, and 3 Akt activity was elevated in PHLDA3-deficient islets, especially under hypoxic conditions. Thus, we determined that PHLDA3-deficient islets are more resistant against stresses induced by islet isolation and transplantation. We conclude that use of islets with suppressed PHLDA3 expression could be a novel and promising treatment for improving engraftment and consequent glycemic control in islet transplantation.

  12. Crybb2 deficiency impairs fertility in female mice

    International Nuclear Information System (INIS)

    Gao, Qian; Sun, Li-Li; Xiang, Fen-Fen; Gao, Li; Jia, Yin; Zhang, Jian-Rong; Tao, Hai-Bo; Zhang, Jun-Jie; Li, Wen-Jie

    2014-01-01

    Highlights: • Crybb2 deletion impaired female fertility. • Crybb2 deletion dramatically affected the production of reproduction-related hormones and hormone response. • Crybb2 deletion impaired follicular development and inhibited the proliferation of granulosa cells. • Crybb2 deletion promoted follicular atresia and apoptosis in granulosa cells. - Abstract: Beta-B2-crystallin (CRYBB2), encoded by Crybb2 gene, is a major protein in the mammalian eye lens that plays an important role in maintaining the transparency of the ocular lens. However, CRYBB2 also plays important roles in many extra-lenticular tissues and organs such as the retina, brain and testis. Our previous studies demonstrated that male Crybb2 deficient (Crybb2 −/− ) mice have reduced fertility compared with wild-type (WT) mice, while female Crybb2 −/− mice exhibited reduced ovary weights and shorter estrous cycle percentages. Here we specifically investigated the role of CRYBB2 in the female reproductive system. Our studies revealed that ovaries from female Crybb2 −/− mice exhibited significantly reduced numbers of primordial, secondary and pre-ovulatory follicles when compared with WT mice, while the rate of atretic follicles was also increased. Additionally, fewer eggs were collected from the oviduct of Crybb2 −/− female mice after superovulation. Estrogen levels were higher in the metestrus and diestrus cycles of female Crybb2 −/− mice, while progesterone levels were lower in diestrus cycles. Furthermore, the expression of survival and cell cycle genes, Bcl-2, Cdk4 and Ccnd2, were significantly decreased in granulosa cells isolated from female Crybb2 −/− mice, consistent with the predominant expression of CRYBB2 in ovarian granulosa cells. Our results reveal a critical role for CRYBB2 in female fertility and specific effects on the proliferation and survival status of ovarian granulosa cells

  13. Crybb2 deficiency impairs fertility in female mice

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Qian [Department of Laboratory Diagnosis, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Sun, Li-Li [Aviation Medical Evaluation and Training Center of Airforce in Dalian, Dalian, Liaoning Province 116013 (China); Department of Laboratory Diagnosis, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Xiang, Fen-Fen [Department of Laboratory Medicine, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200062 (China); Gao, Li [Department of Pathology, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Jia, Yin; Zhang, Jian-Rong; Tao, Hai-Bo [Department of Laboratory Diagnosis, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Zhang, Jun-Jie, E-mail: zhangjj910@163.com [Department of Obstetrics and Gynecology, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Li, Wen-Jie, E-mail: wenjieli@pku.org.cn [Department of Laboratory Diagnosis, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China)

    2014-10-10

    Highlights: • Crybb2 deletion impaired female fertility. • Crybb2 deletion dramatically affected the production of reproduction-related hormones and hormone response. • Crybb2 deletion impaired follicular development and inhibited the proliferation of granulosa cells. • Crybb2 deletion promoted follicular atresia and apoptosis in granulosa cells. - Abstract: Beta-B2-crystallin (CRYBB2), encoded by Crybb2 gene, is a major protein in the mammalian eye lens that plays an important role in maintaining the transparency of the ocular lens. However, CRYBB2 also plays important roles in many extra-lenticular tissues and organs such as the retina, brain and testis. Our previous studies demonstrated that male Crybb2 deficient (Crybb2{sup −/−}) mice have reduced fertility compared with wild-type (WT) mice, while female Crybb2{sup −/−} mice exhibited reduced ovary weights and shorter estrous cycle percentages. Here we specifically investigated the role of CRYBB2 in the female reproductive system. Our studies revealed that ovaries from female Crybb2{sup −/−} mice exhibited significantly reduced numbers of primordial, secondary and pre-ovulatory follicles when compared with WT mice, while the rate of atretic follicles was also increased. Additionally, fewer eggs were collected from the oviduct of Crybb2{sup −/−} female mice after superovulation. Estrogen levels were higher in the metestrus and diestrus cycles of female Crybb2{sup −/−} mice, while progesterone levels were lower in diestrus cycles. Furthermore, the expression of survival and cell cycle genes, Bcl-2, Cdk4 and Ccnd2, were significantly decreased in granulosa cells isolated from female Crybb2{sup −/−} mice, consistent with the predominant expression of CRYBB2 in ovarian granulosa cells. Our results reveal a critical role for CRYBB2 in female fertility and specific effects on the proliferation and survival status of ovarian granulosa cells.

  14. Hypothalamic CART is a new anorectic peptide regulated by leptin.

    Science.gov (United States)

    Kristensen, P; Judge, M E; Thim, L; Ribel, U; Christjansen, K N; Wulff, B S; Clausen, J T; Jensen, P B; Madsen, O D; Vrang, N; Larsen, P J; Hastrup, S

    1998-05-07

    The mammalian hypothalamus strongly influences ingestive behaviour through several different signalling molecules and receptor systems. Here we show that CART (cocaine- and amphetamine-regulated transcript), a brain-located peptide, is a satiety factor and is closely associated with the actions of two important regulators of food intake, leptin and neuropeptide Y. Food-deprived animals show a pronounced decrease in expression of CART messenger RNA in the arcuate nucleus. In animal models of obesity with disrupted leptin signalling, CART mRNA is almost absent from the arcuate nucleus. Peripheral administration of leptin to obese mice stimulates CART mRNA expression. When injected intracerebroventricularly into rats, recombinant CART peptide inhibits both normal and starvation-induced feeding, and completely blocks the feeding response induced by neuropeptide Y. An antiserum against CART increases feeding in normal rats, indicating that CART may be an endogenous inhibitor of food intake in normal animals.

  15. IL-6 Improves Energy and Glucose Homeostasis in Obesity via Enhanced Central IL-6 trans-Signaling.

    Science.gov (United States)

    Timper, Katharina; Denson, Jesse Lee; Steculorum, Sophie Marie; Heilinger, Christian; Engström-Ruud, Linda; Wunderlich, Claudia Maria; Rose-John, Stefan; Wunderlich, F Thomas; Brüning, Jens Claus

    2017-04-11

    Interleukin (IL)-6 engages similar signaling mechanisms to leptin. Here, we find that central application of IL-6 in mice suppresses feeding and improves glucose tolerance. In contrast to leptin, whose action is attenuated in obesity, the ability of IL-6 to suppress feeding is enhanced in obese mice. IL-6 suppresses feeding in the absence of neuronal IL-6-receptor (IL-6R) expression in hypothalamic or all forebrain neurons of mice. Conversely, obese mice exhibit increased soluble IL-6R levels in the cerebrospinal fluid. Blocking IL-6 trans-signaling in the CNS abrogates the ability of IL-6 to suppress feeding. Furthermore, gp130 expression is enhanced in the paraventricular nucleus of the hypothalamus (PVH) of obese mice, and deletion of gp130 in the PVH attenuates the beneficial central IL-6 effects on metabolism. Collectively, these experiments indicate that IL-6 trans-signaling is enhanced in the CNS of obese mice, allowing IL-6 to exert its beneficial metabolic effects even under conditions of leptin resistance. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  16. IL-6 Improves Energy and Glucose Homeostasis in Obesity via Enhanced Central IL-6 trans-Signaling

    Directory of Open Access Journals (Sweden)

    Katharina Timper

    2017-04-01

    Full Text Available Interleukin (IL-6 engages similar signaling mechanisms to leptin. Here, we find that central application of IL-6 in mice suppresses feeding and improves glucose tolerance. In contrast to leptin, whose action is attenuated in obesity, the ability of IL-6 to suppress feeding is enhanced in obese mice. IL-6 suppresses feeding in the absence of neuronal IL-6-receptor (IL-6R expression in hypothalamic or all forebrain neurons of mice. Conversely, obese mice exhibit increased soluble IL-6R levels in the cerebrospinal fluid. Blocking IL-6 trans-signaling in the CNS abrogates the ability of IL-6 to suppress feeding. Furthermore, gp130 expression is enhanced in the paraventricular nucleus of the hypothalamus (PVH of obese mice, and deletion of gp130 in the PVH attenuates the beneficial central IL-6 effects on metabolism. Collectively, these experiments indicate that IL-6 trans-signaling is enhanced in the CNS of obese mice, allowing IL-6 to exert its beneficial metabolic effects even under conditions of leptin resistance.

  17. Glut2-dependent glucose-sensing controls thermoregulation by enhancing the leptin sensitivity of NPY and POMC neurons.

    Science.gov (United States)

    Mounien, Lourdes; Marty, Nell; Tarussio, David; Metref, Salima; Genoux, David; Preitner, Frédéric; Foretz, Marc; Thorens, Bernard

    2010-06-01

    The physiological contribution of glucose in thermoregulation is not completely established nor whether this control may involve a regulation of the melanocortin pathway. Here, we assessed thermoregulation and leptin sensitivity of hypothalamic arcuate neurons in mice with inactivation of glucose transporter type 2 (Glut2)-dependent glucose sensing. Mice with inactivation of Glut2-dependent glucose sensors are cold intolerant and show increased susceptibility to food deprivation-induced torpor and abnormal hypothermic response to intracerebroventricular administration of 2-deoxy-d-glucose compared to control mice. This is associated with a defect in regulated expression of brown adipose tissue uncoupling protein I and iodothyronine deiodinase II and with a decreased leptin sensitivity of neuropeptide Y (NPY) and proopiomelanocortin (POMC) neurons, as observed during the unfed-to-refed transition or following i.p. leptin injection. Sites of central Glut-2 expression were identified by a genetic tagging approach and revealed that glucose-sensitive neurons were present in the lateral hypothalamus, the dorsal vagal complex, and the basal medulla but not in the arcuate nucleus. NPY and POMC neurons were, however, connected to nerve terminals from Glut2-expressing neurons. Thus, our data suggest that glucose controls thermoregulation and the leptin sensitivity of NPY and POMC neurons through activation of Glut2-dependent glucose-sensing neurons located outside of the arcuate nucleus.

  18. Magnesium deficiency induces anxiety-and depression-like behavior and metabolic dysfunction in C57Bl/6J mice

    DEFF Research Database (Denmark)

    Winther, G.; Wang, T.; Singewald, N.

    2012-01-01

    ) in mice through depression-and anxiety phenotyping experiments, namely the forced swim test and light-dark box respectively. We determined the behavioural effects 30 minutes after treatment with imipramine (20 mg/kg), diazepam (2 mg/kg) and ketamine (3 mg/kg). The glucose tolerance test was used to assess...... metabolic function in Mg deficient mice. Results: We found that, compared to control (n=10), mice receiving Mg deficient diet (n=10) (10 % RDA), were more immobile in the forced swim test....

  19. Turmeric Supplementation Improves Serum Glucose Indices and Leptin Levels in Patients with Nonalcoholic Fatty Liver Diseases.

    Science.gov (United States)

    Navekar, Roya; Rafraf, Maryam; Ghaffari, Aida; Asghari-Jafarabadi, Mohammad; Khoshbaten, Manouchehr

    2017-01-01

    Insulin and leptin resistance are important risk factors for non-alcoholic fatty liver disease (NAFLD). There is limited evidence regarding the effects of turmeric on NAFLD. The aim of this study was to investigate the effects of turmeric supplementation on glycemic status and serum leptin levels in patients with NAFLD. This double-blind randomized controlled clinical trial was conducted on 46 patients with NAFLD (21males and 25 females) aged 20-60 years old and body mass index (BMI) between 24.9 and 40 kg/m2. The turmeric group (n = 23) was given six turmeric capsules daily for 12 weeks. Each capsule contained 500 mg turmeric powder (6×500 mg). The placebo group (n = 23) was given six placebo capsules daily for the same period. Fasting blood samples, anthropometric measurements, and physical activity levels were collected at the baseline and at the end of the study. Daily dietary intakes also were obtained throughout the study. Data were analyzed by independent t test, paired t test and analysis of covariance. Turmeric consumption decreased serum levels of glucose, insulin, HOMA-IR and leptin (by 1.22, 17.69, 19.48 and 21.33% respectively, p Turmeric supplementation improved glucose indexes and serum leptin levels and may be useful in the control of NAFLD complications.

  20. Loss of synaptic zinc transport in progranulin deficient mice may contribute to progranulin-associated psychopathology and chronic pain.

    Science.gov (United States)

    Hardt, Stefanie; Heidler, Juliana; Albuquerque, Boris; Valek, Lucie; Altmann, Christine; Wilken-Schmitz, Annett; Schäfer, Michael K E; Wittig, Ilka; Tegeder, Irmgard

    2017-11-01

    Affective and cognitive processing of nociception contributes to the development of chronic pain and vice versa, pain may precipitate psychopathologic symptoms. We hypothesized a higher risk for the latter with immanent neurologic diseases and studied this potential interrelationship in progranulin-deficient mice, which are a model for frontotemporal dementia, a disease dominated by behavioral abnormalities in humans. Young naïve progranulin deficient mice behaved normal in tests of short-term memory, anxiety, depression and nociception, but after peripheral nerve injury, they showed attention-deficit and depression-like behavior, over-activity, loss of shelter-seeking, reduced impulse control and compulsive feeding behavior, which did not occur in equally injured controls. Hence, only the interaction of 'pain x progranulin deficiency' resulted in the complex phenotype at young age, but neither pain nor progranulin deficiency alone. A deep proteome analysis of the prefrontal cortex and olfactory bulb revealed progranulin-dependent alterations of proteins involved in synaptic transport, including neurotransmitter transporters of the solute carrier superfamily. In particular, progranulin deficiency was associated with a deficiency of nuclear and synaptic zinc transporters (ZnT9/Slc30a9; ZnT3/Slc30a3) with low plasma zinc. Dietary zinc supplementation partly normalized the attention deficit of progranulin-deficient mice, which was in part reminiscent of autism-like and compulsive behavior of synaptic zinc transporter Znt3-knockout mice. Hence, the molecular studies point to defective zinc transport possibly contributing to progranulin-deficiency-associated psychopathology. Translated to humans, our data suggest that neuropathic pain may precipitate cognitive and psychopathological symptoms of an inherent, still silent neurodegenerative disease. Copyright © 2017. Published by Elsevier B.V.

  1. High Mutation Levels are Compatible with Normal Embryonic Development in Mlh1-Deficient Mice.

    Science.gov (United States)

    Fan, Xiaoyan; Li, Yan; Zhang, Yulong; Sang, Meixiang; Cai, Jianhui; Li, Qiaoxia; Ozaki, Toshinori; Ono, Tetsuya; He, Dongwei

    2016-10-01

    To elucidate the role of the mismatch repair gene Mlh1 in genome instability during the fetal stage, spontaneous mutations were studied in Mlh1-deficient lacZ-transgenic mouse fetuses. Mutation levels were high at 9.5 days post coitum (dpc) and gradually increased during the embryonic stage, after which they remained unchanged. In addition, mutations that were found in brain, liver, spleen, small intestine and thymus showed similar levels and no statistically significant difference was found. The molecular nature of mutations at 12.5 dpc in fetuses of Mlh1 +/+ and Mlh1 -/- mice showed their own unique spectra, suggesting that deletion mutations were the main causes in the deficiency of the Mlh1 gene. Of note, fetuses of irradiated mice exhibited marked differences such as post-implantation loss and Mendelian distribution. Collectively, these results strongly suggest that high mutation ofMlh1 -/- -deficient fetuses has little effect on the fetuses during their early developmental stages, whereas Mlh1 -/- -deficient fetuses from X-ray irradiated mothers are clearly effected.

  2. Telomerase-Deficient Mice Exhibit Bone Loss Owing to Defects in Osteoblasts and Increased Osteoclastogenesis by Inflammatory Microenvironment

    DEFF Research Database (Denmark)

    Saeed, H.; Abdallah, B. M.; Ditzel, N.

    2011-01-01

    Telomere shortening owing to telomerase deficiency leads to accelerated senescence of human skeletal (mesenchymal) stem cells (MSCs) in vitro, whereas overexpression leads to telomere elongation, extended life span, and enhanced bone formation. To study the role of telomere shortening in vivo, we...... studied the phenotype of telomerase-deficient mice (Terc(-/-)).Terc(-/-) mice exhibited accelerated age-related bone loss starting at 3 months of age and during 12 months of follow-up revealed by dual-energy X-ray absorptiometric (DXA) scanning and by micro-computed tomography (mu CT). Bone...... histomorphometry revealed decreased mineralized surface and bone-formation rate as well as increased osteoclast number and size in Terc(-/-) mice. Also, serum total deoxypyridinoline (tDPD) was increased in Terc(-/-) mice. MSCs and osteoprogenitors isolated from Terc(-l-) mice exhibited intrinsic defects...

  3. Interleukin 1α-Deficient Mice Have an Altered Gut Microbiota Leading to Protection from Dextran Sodium Sulfate-Induced Colitis.

    Science.gov (United States)

    Nunberg, Moran; Werbner, Nir; Neuman, Hadar; Bersudsky, Marina; Braiman, Alex; Ben-Shoshan, Moshe; Ben Izhak, Meirav; Louzoun, Yoram; Apte, Ron N; Voronov, Elena; Koren, Omry

    2018-01-01

    Inflammatory bowel diseases (IBD) are a group of chronic inflammatory disorders of the intestine, with as-yet-unclear etiologies, affecting over a million people in the United States alone. With the emergence of microbiome research, numerous studies have shown a connection between shifts in the gut microbiota composition (dysbiosis) and patterns of IBD development. In a previous study, we showed that interleukin 1α (IL-1α) deficiency in IL-1α knockout (KO) mice results in moderate dextran sodium sulfate (DSS)-induced colitis compared to that of wild-type (WT) mice, characterized by reduced inflammation and complete healing, as shown by parameters of weight loss, disease activity index (DAI) score, histology, and cytokine expression. In this study, we tested whether the protective effects of IL-1α deficiency on DSS-induced colitis correlate with changes in the gut microbiota and whether manipulation of the microbiota by cohousing can alter patterns of colon inflammation. We analyzed the gut microbiota composition in both control (WT) and IL-1α KO mice under steady-state homeostasis, during acute DSS-induced colitis, and after recovery using 16S rRNA next-generation sequencing. Additionally, we performed cohousing of both mouse groups and tested the effects on the microbiota and clinical outcomes. We demonstrate that host-derived IL-1α has a clear influence on gut microbiota composition, as well as on severity of DSS-induced acute colon inflammation. Cohousing both successfully changed the gut microbiota composition and increased the disease severity of IL-1α-deficient mice to levels similar to those of WT mice. This study shows a strong and novel correlation between IL-1α expression, microbiota composition, and clinical outcomes of DSS-induced colitis. IMPORTANCE Here, we show a connection between IL-1α expression, microbiota composition, and clinical outcomes of DSS-induced colitis. Specifically, we show that the mild colitis symptoms seen in IL-1α-deficient

  4. Reprogramming the body weight set point by a reciprocal interaction of hypothalamic leptin sensitivity and Pomc gene expression reverts extreme obesity

    Directory of Open Access Journals (Sweden)

    Kavaljit H. Chhabra

    2016-10-01

    Conclusions: Pomc reactivation in previously obese, calorie-restricted ArcPomc−/− mice normalized energy homeostasis, suggesting that their body weight set point was restored to control levels. In contrast, massively obese and hyperleptinemic ArcPomc−/− mice or those weight-matched and treated with PASylated leptin to maintain extreme hyperleptinemia prior to Pomc reactivation converged to an intermediate set point relative to lean control and obese ArcPomc−/− mice. We conclude that restoration of hypothalamic leptin sensitivity and Pomc expression is necessary for obese ArcPomc−/− mice to achieve and sustain normal metabolic homeostasis; whereas deficits in either parameter set a maladaptive allostatic balance that defends increased adiposity and body weight.

  5. Gender-specific effects of endogenous testosterone: female alpha-estrogen receptor-deficient C57Bl/6J mice develop glomerulosclerosis.

    Science.gov (United States)

    Elliot, S J; Berho, M; Korach, K; Doublier, S; Lupia, E; Striker, G E; Karl, M

    2007-08-01

    Young female mice on a C57Bl/6J (B6) background are considered glomerulosclerosis (GS)-resistant but aging B6 mice develop mild GS. Estrogen deficiency accelerates while estrogen replacement retards GS in young sclerosis-prone oligosyndactyly mutant mice on an ROP background. To explore the effects of sex hormones on glomerular structure and function in the context of gender and genetic background, we studied mice in which the estrogen-receptor (ER) genes alpha- or -beta were deleted (alpha- or betaER knockout (KO)) and crossed into the B6 background. We also studied ovariectomized (Ovx) B6 mice given testosterone. Male and female betaERKO and male alphaERKO mice had no glomerular dysfunction at 9 months of age; however, alphaERKO female mice displayed albuminuria and GS. Ovx prevented glomerular dysfunction in alphaERKO female mice by eliminating endogenous testosterone production while exogenous testosterone induced GS in Ovx B6 mice. Androgen receptor (AR) expression and function was found in microdissected glomeruli and cultured mesangial cells. Testosterone compared to placebo increased both AR expression and TGF-beta1 mRNA levels in glomeruli isolated from female B6 mice. Estrogen deficiency had no deleterious effects on the glomeruli in B6 mice. Our study shows that genetic traits strongly influence the GS-promoting effects of estrogen deficiency while testosterone induces GS in a gender-specific manner.

  6. Citrullus lanatus 'sentinel' (watermelon) extract reduces atherosclerosis in LDL receptor-deficient mice.

    Science.gov (United States)

    Poduri, Aruna; Rateri, Debra L; Saha, Shubin K; Saha, Sibu; Daugherty, Alan

    2013-05-01

    Watermelon (Citrullus lanatus or C. lanatus) has many potentially bioactive compounds including citrulline, which may influence atherosclerosis. In this study, we determined the effects of C. lanatus, provided as an extract of the cultivar 'sentinel,' on hypercholesterolemia-induced atherosclerosis in mice. Male low-density lipoprotein receptor-deficient mice at 8 weeks old were given either C. lanatus 'sentinel' extract (2% vol/vol; n=10) or a mixture of matching carbohydrates (2% vol/vol; n=8) as the control in drinking water while being fed a saturated fat-enriched diet for 12 weeks ad libitum. Mice consuming C. lanatus 'sentinel' extract had significantly increased plasma citrulline concentrations. Systolic blood pressure was comparable between the two groups. Consumption of C. lanatus 'sentinel' extract led to lower body weight and fat mass without influencing lean mass. There were no differences in food and water intake and in urine output between the two groups. C. lanatus 'sentinel' extract administration decreased plasma cholesterol concentrations that were attributed to reductions of intermediate-/low-density lipoprotein cholesterol. Plasma concentrations of monocyte chemoattractant protein-1 and interferon-gamma were decreased and those of interleukin-10 were increased in mice consuming C. lanatus 'sentinel' extract. Intake of C. lanatus 'sentinel' extract resulted in reductions of atherosclerosis in both aortic arch and thoracic regions. In conclusion, consumption of C. lanatus 'sentinel' extract led to reduced body weight gain, decreased plasma cholesterol concentrations, improved homeostasis of pro- and anti-inflammatory cytokines, and attenuated development of atherosclerosis without affecting systolic blood pressure in hypercholesterolemic mice. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. [Serum leptin levels and soluble leptin receptors in female patients with anorexia nervosa].

    Science.gov (United States)

    Jiskra, J; Haluzík, M; Svobodová, J; Haluzíková, D; Nedvídková, J; Parízková, J; Kotrlíková, E

    2000-10-25

    Leptin action in peripheral tissues is enabled by an interaction with specific transmembrane receptors. Several of leptin receptor isoforms were identified, including soluble leptin receptor isoform structurally identical to extracellular domain of the the long leptin receptor isoform. The soluble receptor isoform is released to the circulation and acts probably as leptin-binding factor. The aim of our study was to measure serum concentrations of the soluble leptin receptor in patients with anorexia nervosa and in the control group of healthy women. Relationships of soluble leptin receptor levels to body mass index (BMI), body fat content, serum leptin, TNF-alpha and insulin levels were also studied. 16 patients with anorexia nervosa and 16 age-matched lean healthy women were included into the study. All of the subjects were measured and weighed, the body fat content was estimated from the skinfold thickness measurement. The blood for the determination of leptin, soluble leptin receptor and other hormonal parameters was obtained from all subjects after the overnight fasting. BMI, body fat content, serum leptin and insulin levels in patients with anorexia nervosa were significantly lower than in the control group (BMI: 14.98 +/- 2.32 vs. 22.21 +/- 2.48, p anorexia nervosa were significantly higher compared the to control group (24.67 +/- 8.3 U.ml-1 vs. 15.71 +/- 2.79 U.ml-1, p anorexia nervosa were significantly higher in comparison with the healthy subjects. Except of the negative correlation between serum soluble leptin receptor levels and BMI no statistically significant relationships between serum soluble leptin receptor and the rest of parameters studied were found.

  8. Hypothalamic growth hormone receptor (GHR) controls hepatic glucose production in nutrient-sensing leptin receptor (LepRb) expressing neurons.

    Science.gov (United States)

    Cady, Gillian; Landeryou, Taylor; Garratt, Michael; Kopchick, John J; Qi, Nathan; Garcia-Galiano, David; Elias, Carol F; Myers, Martin G; Miller, Richard A; Sandoval, Darleen A; Sadagurski, Marianna

    2017-05-01

    The GH/IGF-1 axis has important roles in growth and metabolism. GH and GH receptor (GHR) are active in the central nervous system (CNS) and are crucial in regulating several aspects of metabolism. In the hypothalamus, there is a high abundance of GH-responsive cells, but the role of GH signaling in hypothalamic neurons is unknown. Previous work has demonstrated that the Ghr gene is highly expressed in LepRb neurons. Given that leptin is a key regulator of energy balance by acting on leptin receptor (LepRb)-expressing neurons, we tested the hypothesis that LepRb neurons represent an important site for GHR signaling to control body homeostasis. To determine the importance of GHR signaling in LepRb neurons, we utilized Cre/loxP technology to ablate GHR expression in LepRb neurons (Lepr EYFPΔGHR ). The mice were generated by crossing the Lepr cre on the cre-inducible ROSA26-EYFP mice to GHR L/L mice. Parameters of body composition and glucose homeostasis were evaluated. Our results demonstrate that the sites with GHR and LepRb co-expression include ARH, DMH, and LHA neurons. Leptin action was not altered in Lepr EYFPΔGHR mice; however, GH-induced pStat5-IR in LepRb neurons was significantly reduced in these mice. Serum IGF-1 and GH levels were unaltered, and we found no evidence that GHR signaling regulates food intake and body weight in LepRb neurons. In contrast, diminished GHR signaling in LepRb neurons impaired hepatic insulin sensitivity and peripheral lipid metabolism. This was paralleled with a failure to suppress expression of the gluconeogenic genes and impaired hepatic insulin signaling in Lepr EYFPΔGHR mice. These findings suggest the existence of GHR-leptin neurocircuitry that plays an important role in the GHR-mediated regulation of glucose metabolism irrespective of feeding.

  9. Deficiency of cyclin-dependent kinase inhibitors p21Cip1 and p27Kip1 accelerates atherogenesis in apolipoprotein E-deficient mice

    International Nuclear Information System (INIS)

    Akyuerek, Levent M.; Boehm, Manfred; Olive, Michelle; Zhou, Alex-Xianghua; San, Hong; Nabel, Elizabeth G.

    2010-01-01

    Cyclin-dependent kinase inhibitors, p21 Cip1 and p27 Kip1 , are upregulated during vascular cell proliferation and negatively regulate growth of vascular cells. We hypothesized that absence of either p21 Cip1 or p27 Kip1 in apolipoprotein E (apoE)-deficiency may increase atherosclerotic plaque formation. Compared to apoE -/- aortae, both apoE -/- /p21 -/- and apoE -/- /p27 -/- aortae exhibited significantly more atherosclerotic plaque following a high-cholesterol regimen. This increase was particularly observed in the abdominal aortic regions. Deficiency of p27 Kip1 accelerated plaque formation significantly more than p21 -/- in apoE -/- mice. This increased plaque formation was in parallel with increased intima/media area ratios. Deficiency of p21 Cip1 and p27 Kip1 accelerates atherogenesis in apoE -/- mice. These findings have significant implications for our understanding of the molecular basis of atherosclerosis associated with excessive proliferation of vascular cells.

  10. Development of hepatocellular adenomas and carcinomas in mice with liver-specific G6Pase-α deficiency

    Directory of Open Access Journals (Sweden)

    Roberta Resaz

    2014-09-01

    Full Text Available Glycogen storage disease type 1a (GSD-1a is caused by a deficiency in glucose-6-phosphatase-α (G6Pase-α, and is characterized by impaired glucose homeostasis and a high risk of developing hepatocellular adenomas (HCAs. A globally G6Pase-α-deficient (G6pc−/− mouse model that shows pathological features similar to those of humans with GSD-1a has been developed. These mice show a very severe phenotype of disturbed glucose homeostasis and rarely live beyond weaning. We generated liver-specific G6Pase-α-deficient (LS‑G6pc−/− mice as an alternative animal model for studying the long-term pathophysiology of the liver and the potential treatment strategies, such as cell therapy. LS‑G6pc−/− mice were viable and exhibited normal glucose profiles in the fed state, but showed significantly lower blood glucose levels than their control littermates after 6 hours of fasting. LS‑G6pc−/− mice developed hepatomegaly with glycogen accumulation and hepatic steatosis, and progressive hepatic degeneration. Ninety percent of the mice analyzed developed amyloidosis by 12 months of age. Finally, 25% of the mice sacrificed at age 10–20 months showed the presence of multiple HCAs and in one case late development of hepatocellular carcinoma (HCC. In conclusion, LS‑G6pc−/− mice manifest hepatic symptoms similar to those of human GSD-1a and, therefore, represent a valid model to evaluate long-term liver pathogenesis of GSD-1a.

  11. Leptin Inhibits the Proliferation of Vascular Smooth Muscle Cells Induced by Angiotensin II through Nitric Oxide-Dependent Mechanisms

    Directory of Open Access Journals (Sweden)

    Amaia Rodríguez

    2010-01-01

    Full Text Available Objective. This study was designed to investigate whether leptin modifies angiotensin (Ang II-induced proliferation of aortic vascular smooth muscle cells (VSMCs from 10-week-old male Wistar and spontaneously hypertensive rats (SHR, and the possible role of nitric oxide (NO. Methods. NO and NO synthase (NOS activity were assessed by the Griess and 3H-arginine/citrulline conversion assays, respectively. Inducible NOS (iNOS and NADPH oxidase subutnit Nox2 expression was determined by Western-blot. The proliferative responses to Ang II were evaluated through enzymatic methods. Results. Leptin inhibited the Ang II-induced proliferative response of VSMCs from control rats. This inhibitory effect of leptin was abolished by NOS inhibitor, NMMA, and iNOS selective inhibitor, L-NIL, and was not observed in leptin receptor-deficient fa/fa rats. SHR showed increased serum leptin concentrations and lipid peroxidation. Despite a similar leptin-induced iNOS up-regulation, VSMCs from SHR showed an impaired NOS activity and NO production induced by leptin, and an increased basal Nox2 expression. The inhibitory effect of leptin on Ang II-induced VSMC proliferation was attenuated. Conclusion. Leptin blocks the proliferative response to Ang II through NO-dependent mechanisms. The attenuation of this inhibitory effect of leptin in spontaneous hypertension appears to be due to a reduced NO bioavailability in VSMCs.

  12. Factor XI Deficiency Alters the Cytokine Response and Activation of Contact Proteases during Polymicrobial Sepsis in Mice.

    Directory of Open Access Journals (Sweden)

    Charles E Bane

    Full Text Available Sepsis, a systemic inflammatory response to infection, is often accompanied by abnormalities of blood coagulation. Prior work with a mouse model of sepsis induced by cecal ligation and puncture (CLP suggested that the protease factor XIa contributed to disseminated intravascular coagulation (DIC and to the cytokine response during sepsis. We investigated the importance of factor XI to cytokine and coagulation responses during the first 24 hours after CLP. Compared to wild type littermates, factor XI-deficient (FXI-/- mice had a survival advantage after CLP, with smaller increases in plasma levels of TNF-α and IL-10 and delayed IL-1β and IL-6 responses. Plasma levels of serum amyloid P, an acute phase protein, were increased in wild type mice 24 hours post-CLP, but not in FXI-/- mice, supporting the impression of a reduced inflammatory response in the absence of factor XI. Surprisingly, there was little evidence of DIC in mice of either genotype. Plasma levels of the contact factors factor XII and prekallikrein were reduced in WT mice after CLP, consistent with induction of contact activation. However, factor XII and PK levels were not reduced in FXI-/- animals, indicating factor XI deficiency blunted contact activation. Intravenous infusion of polyphosphate into WT mice also induced changes in factor XII, but had much less effect in FXI deficient mice. In vitro analysis revealed that factor XIa activates factor XII, and that this reaction is enhanced by polyanions such polyphosphate and nucleic acids. These data suggest that factor XI deficiency confers a survival advantage in the CLP sepsis model by altering the cytokine response to infection and blunting activation of the contact (kallikrein-kinin system. The findings support the hypothesis that factor XI functions as a bidirectional interface between contact activation and thrombin generation, allowing the two processes to influence each other.

  13. Role of PTP1B in POMC neurons during chronic high-fat diet: sex differences in regulation of liver lipids and glucose tolerance.

    Science.gov (United States)

    Aberdein, Nicola; Dambrino, Robert J; do Carmo, Jussara M; Wang, Zhen; Mitchell, Laura E; Drummond, Heather A; Hall, John E

    2018-03-01

    Protein tyrosine phosphatase 1B (PTP1B) is a negative regulator of leptin receptor signaling and may contribute to leptin resistance in diet-induced obesity. Although PTP1B inhibition has been suggested as a potential weight loss therapy, the role of specific neuronal PTP1B signaling in cardiovascular and metabolic regulation and the importance of sex differences in this regulation are still unclear. In this study, we investigated the impact of proopiomelanocortin (POMC) neuronal PTP1B deficiency in cardiometabolic regulation in male and female mice fed a high-fat diet (HFD). When compared with control mice (PTP1B flox/flox ), male and female mice deficient in POMC neuronal PTP1B (PTP1B flox/flox /POMC-Cre) had attenuated body weight gain (males: -18%; females: -16%) and fat mass (males: -33%; female: -29%) in response to HFD. Glucose tolerance was improved by 40%, and liver lipid accumulation was reduced by 40% in PTP1B/POMC-Cre males but not in females. When compared with control mice, deficiency of POMC neuronal PTP1B did not alter mean arterial pressure (MAP) in male or female mice (males: 112 ± 1 vs. 112 ± 1 mmHg in controls; females: 106 ± 3 vs. 109 ± 3 mmHg in controls). Deficiency of POMC neuronal PTP1B also did not alter MAP response to acute stress in males or females compared with control mice (males: Δ32 ± 0 vs. Δ29 ± 4 mmHg; females: Δ22 ± 2 vs. Δ27 ± 4 mmHg). These data demonstrate that POMC-specific PTP1B deficiency improved glucose tolerance and attenuated diet-induced fatty liver only in male mice and attenuated weight gain in males and females but did not enhance the MAP and HR responses to a HFD or to acute stress.

  14. Timing of growth hormone treatment affects trabecular bone microarchitecture and mineralization in growth hormone deficient mice.

    Science.gov (United States)

    Kristensen, Erika; Hallgrímsson, Benedikt; Morck, Douglas W; Boyd, Steven K

    2010-08-01

    Growth hormone (GH) is essential in the development of bone mass, and a growth hormone deficiency (GHD) in childhood is frequently treated with daily injections of GH. It is not clear what effect GHD and its treatment has on bone. It was hypothesized that GHD would result in impaired microarchitecture, and an early onset of treatment would result in a better recovery than late onset. Growth hormone deficient homozygous (lit/lit) mice of both sexes were divided into two treatment groups receiving daily injections of GH, starting at an early (21 days of age) or a late time point (35 days of age, corresponding to the end of puberty). A group of heterozygous mice with normal levels of growth hormone served as controls. In vivo micro-computed tomography scans of the fourth lumbar vertebra were obtained at five time points between 21 and 60 days of age, and trabecular morphology and volumetric BMD were analyzed to determine the effects of GH on bone microarchitecture. Early GH treatment led to significant improvements in bone volume ratio (p=0.006), tissue mineral density (p=0.005), and structure model index (p=0.004) by the study endpoint (day 60), with no detected change in trabecular thickness. Trabecular number increased and trabecular separation decreased in GHD mice regardless of treatment compared to heterozygous mice. This suggests fundamental differences in the structure of trabecular bone in GHD and GH treated mice, reflected by an increased number of thinner trabeculae in these mice compared to heterozygous controls. There were no significant differences between the late treatment group and GHD mice except for connectivity density. Taken together, these results indicate that bone responds to GH treatment initiated before puberty but not to treatment commencing post-puberty, and that GH treatment does not rescue the structure of trabecular bone to that of heterozygous controls. Copyright 2010 Elsevier Inc. All rights reserved.

  15. Leptin as a Potential Regulator of FGF21

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    Mohamed Asrih

    2016-03-01

    Full Text Available Background/Aims: Fibroblast growth factor 21 (FGF21, a potent metabolic regulator, has been shown to improve insulin sensitivity in animal models of insulin resistance. Several studies have focused on identifying mediators of FGF21 effects. However, the identification of factors involved in FGF21 regulation is far from complete. As leptin is a potent metabolic modulator as well, we aimed at characterizing whether leptin may regulate FGF21. Methods: We investigated a potential regulation of FGF21 by leptin in vivo in Wistar rats and in vitro using human derived hepatocarcinoma HepG2 cells. This model was chosen as the liver is considered the main FGF21 expression site. Results: We found that leptin injections increased plasma FGF21 levels in adult Wistar rats. This was confirmed in vitro, as leptin increased FGF21 expression in HepG2 cells. We also showed that the leptin effect on FGF21 expression was mediated by STAT3 activation in HepG2 cells. Conclusion: New findings regarding a leptin-STAT3-FGF21 axis were provided in this study, although investigating the exact mechanisms linking leptin and FGF21 are still needed. These results are of great interest in the context of identifying potential new clinical approaches to treat metabolic diseases associated with insulin resistance, such as obesity and type 2 diabetes.

  16. BTB and CNC homolog 1 (Bach1) deficiency ameliorates TNBS colitis in mice: role of M2 macrophages and heme oxygenase-1.

    Science.gov (United States)

    Harusato, Akihito; Naito, Yuji; Takagi, Tomohisa; Uchiyama, Kazuhiko; Mizushima, Katsura; Hirai, Yasuko; Higashimura, Yasuki; Katada, Kazuhiro; Handa, Osamu; Ishikawa, Takeshi; Yagi, Nobuaki; Kokura, Satoshi; Ichikawa, Hiroshi; Muto, Akihiko; Igarashi, Kazuhiko; Yoshikawa, Toshikazu

    2013-01-01

    BTB and CNC homolog 1 (Bach1) is a transcriptional repressor of heme oxygenase-1 (HO-1), which plays an important role in the protection of cells and tissues against acute and chronic inflammation. However, the role of Bach1 in the gastrointestinal mucosal defense system remains little understood. HO-1 supports the suppression of experimental colitis and localizes mainly in macrophages in colonic mucosa. This study was undertaken to elucidate the Bach1/HO-1 system's effects on the pathogenesis of experimental colitis. This study used C57BL/6 (wild-type) and homozygous Bach1-deficient C57BL/6 mice in which colonic damage was induced by the administration of an enema of 2,4,6-trinitrobenzene sulfonic acid (TNBS). Subsequently, they were evaluated macroscopically, histologically, and biochemically. Peritoneal macrophages from the respective mice were isolated and analyzed. Then, wild-type mice were injected with peritoneal macrophages from the respective mice. Acute colitis was induced similarly. TNBS-induced colitis was inhibited in Bach1-deficient mice. TNBS administration increased the expression of HO-1 messenger RNA and protein in colonic mucosa in Bach1-deficient mice. The expression of HO-1 mainly localized in F4/80-immunopositive and CD11b-immunopositive macrophages. Isolated peritoneal macrophages from Bach1-deficient mice highly expressed HO-1 and also manifested M2 macrophage markers, such as Arginase-1, Fizz-1, Ym1, and MRC1. Furthermore, TNBS-induced colitis was inhibited by the transfer of Bach1-deficient macrophages into wild-type mice. Deficiency of Bach1 ameliorated TNBS-induced colitis. Bach1-deficient macrophages played a key role in protection against colitis. Targeting of this mechanism is applicable to cell therapy for human inflammatory bowel disease.

  17. Leptin responsiveness to energy restriction: genetic variation in the leptin receptor gene.

    Science.gov (United States)

    Mars, Monica; van Rossum, Caroline T M; de Graaf, Cees; Hoebee, Barbara; De Groot, Lisette C P G M; Kok, Frans J

    2004-03-01

    Serum leptin concentrations are an important afferent signal in energy balance homeostasis. It has been speculated that the leptin responsiveness to energy restriction is affected by the functionality of the leptin receptor. The purpose of this analysis was to explore the effect of polymorphisms in the LEPR gene on the acute decline in leptin after 4 days of 65% energy restriction. Leptin concentrations of the study group (n = 44; all men) declined by 2.3 +/- 1.5 micro g/L [-39.4% (95% confidence interval: -43.6 to -34.9)]. Leptin responses did not statistically differ between noncarriers and carriers of three mutant variants of the polymorphisms: Lys109/Lys109 (-41.4%) vs. Arg109/+ (-37.0%) (p = 0.33); Gln223/Gln223 (-41.5%) vs. Arg223/+ (-37.8%) (p = 0.40); Lys656/Lys656 (-39.5%) vs. Asn656/+ (-39.3%) (p = 0.96). No effect of the assessed polymorphisms in the LEPR gene on the acute decline in leptin after energy restriction was observed. Power calculations are provided for future studies on the leptin responsiveness to energy restriction.

  18. Mother and Infant Body Mass Index, Breast Milk Leptin and Their Serum Leptin Values.

    Science.gov (United States)

    Savino, Francesco; Sardo, Allegra; Rossi, Lorenza; Benetti, Stefania; Savino, Andrea; Silvestro, Leandra

    2016-06-21

    This study investigates correlations between mother and infant Body Mass Index (BMI), their serum leptin values and breast milk leptin concentration in early infancy. We determined serum leptin values in 58 healthy infants and leptin values in their mothers' breast milk, using radioimmunoassay (RIA). Infant and maternal anthropometrics were measured. Median leptin concentration was 3.9 ng/mL (interquartile range (IQR): 2.75) in infant serum, 4.27 ng/mL (IQR: 5.62) in maternal serum and 0.89 ng/mL (IQR: 1.32) in breast milk. Median maternal BMI and weight were 24 kg/m² (IQR: 4.41) and 64 kg (IQR: 15). Median infant BMI was 15.80 kg/cm² (IQR: 4.02), while average weight was 5.130 kg (IQR: 1.627). Infants serum leptin values positively correlated with infants' BMI (p = 0.001; r = 0.213) and breast milk leptin (p = 0.03; r = 0.285). Maternal serum leptin values positively correlated with maternal BMI (p = 0.000, r = 0.449) and breast milk leptin ones (p = 0.026; r = 0.322). Breast milk leptin and maternal BMI could influence infant serum leptin values. Further studies are needed to better elucidate the role of genetics and environment on infant leptin production and risk of obesity later in life.

  19. Improved Human Erythropoiesis and Platelet Formation in Humanized NSGW41 Mice

    Directory of Open Access Journals (Sweden)

    Susann Rahmig

    2016-10-01

    Full Text Available Human erythro-megakaryopoiesis does not occur in humanized mouse models, preventing the in vivo analysis of human hematopoietic stem cell (HSC differentiation into these lineages in a surrogate host. Here we show that stably engrafted KIT-deficient NOD/SCID Il2rg−/− KitW41/W41 (NSGW41 mice support much improved human erythropoiesis and platelet formation compared with irradiated NSG recipients. Considerable numbers of human erythroblasts and mature thrombocytes are present in the bone marrow and blood, respectively. Morphology, composition, and enucleation capacity of de novo generated human erythroblasts in NSGW41 mice are comparable with those in human bone marrow. Overexpression of human erythropoietin showed no further improvement in human erythrocyte output, but depletion of macrophages led to the appearance of human erythrocytes in the blood. Human erythropoiesis up to normoblasts and platelet formation is fully supported in NSGW41 mice, allowing the analysis of human HSC differentiation into these lineages, the exploration of certain pathophysiologies, and the evaluation of gene therapeutic approaches.

  20. Deficient Mechanical Activation of Anabolic Transcripts and Post-Traumatic Cartilage Degeneration in Matrilin-1 Knockout Mice.

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    Yupeng Chen

    Full Text Available Matrilin-1 (Matn1, a cartilage-specific peri-cellular and extracellular matrix (ECM protein, has been hypothesized to regulate ECM interactions and transmit mechanical signals in cartilage. Since Matn1 knock-out (Matn1-/- mice exhibit a normal skeleton, its function in vivo is unclear. In this study, we found that the anabolic Acan and Col2a transcript levels were significantly higher in wildtype (Matn1+/+ mouse cartilage than that of MATN1-/- mice in vivo. However, such difference was not observed between Matn1+/+ and MATN1-/- chondrocytes cultured under stationary conditions in vitro. Cyclic loading significantly stimulated Acan and Col2a transcript levels in Matn1+/+ but not in MATN1-/- chondrocytes. This suggests that, while Matn1+/+ chondrocytes increase their anabolic gene expression in response to mechanical loading, the MATN1-/- chondrocytes fail to do so because of the deficiency in mechanotransduction. We also found that altered elastic modulus of cartilage matrix in Matn1-/- mice, suggesting the mechanotransduction has changed due to the deficiency of Matn1. To understand the impact of such deficiency on joint disease, mechanical loading was altered in vivo by destabilization of medial meniscus. While Matn1+/+ mice exhibited superficial fissures and clefts consistent with mechanical damage to the articular joint, Matn1-/- mice presented more severe cartilage lesions characterized by proteoglycan loss and disorganization of cells and ECM. This suggests that Matn1 deficiency affects pathogenesis of post-traumatic osteoarthritis by failing to up-regulate anabolic gene expression. This is the first demonstration of Matn1 function in vivo, which suggests its protective role in cartilage degeneration under altered mechanical environment.

  1. Gene therapy/bone marrow transplantation in ADA-deficient mice: roles of enzyme-replacement therapy and cytoreduction.

    Science.gov (United States)

    Carbonaro, Denise A; Jin, Xiangyang; Wang, Xingchao; Yu, Xiao-Jin; Rozengurt, Nora; Kaufman, Michael L; Wang, Xiaoyan; Gjertson, David; Zhou, Yang; Blackburn, Michael R; Kohn, Donald B

    2012-11-01

    Gene therapy (GT) for adenosine deaminase-deficient severe combined immune deficiency (ADA-SCID) can provide significant long-term benefit when patients are given nonmyeloablative conditioning and ADA enzyme-replacement therapy (ERT) is withheld before autologous transplantation of γ-retroviral vector-transduced BM CD34+ cells. To determine the contributions of conditioning and discontinuation of ERT to the therapeutic effects, we analyzed these factors in Ada gene knockout mice (Ada(-/-)). Mice were transplanted with ADA-deficient marrow transduced with an ADA-expressing γ-retroviral vector without preconditioning or after 200 cGy or 900 cGy total-body irradiation and evaluated after 4 months. In all tissues analyzed, vector copy numbers (VCNs) were 100- to 1000-fold greater in mice receiving 900 cGy compared with 200 cGy (P < .05). In mice receiving 200 cGy, VCN was similar whether ERT was stopped or given for 1 or 4 months after GT. In unconditioned mice, there was decreased survival with and without ERT, and VCN was very low to undetectable. When recipients were conditioned with 200 cGy and received transduced lineage-depleted marrow, only recipients receiving ERT (1 or 4 months) had detectable vector sequences in thymocytes. In conclusion, cytoreduction is important for the engraftment of gene-transduced HSC, and short-term ERT after GT did not diminish the capacity of gene-corrected cells to engraft and persist.

  2. Niemann-Pick C1-deficient mice lacking sterol O-acyltransferase 2 have less hepatic cholesterol entrapment and improved liver function.

    Science.gov (United States)

    Lopez, Adam M; Jones, Ryan Dale; Repa, Joyce J; Turley, Stephen D

    2018-06-07

    Cholesteryl esters are generated at multiple sites in the body by sterol O-acyltransferase 1 (SOAT1) or sterol O-acyltransferase 2 (SOAT2) in various cell types, and lecithin cholesterol acyltransferase (LCAT) in plasma. Esterified cholesterol (EC) and triacylglycerol (TAG) contained in lipoproteins cleared from the circulation via receptor-mediated or bulk-phase endocytosis are hydrolyzed by lysosomal acid lipase (LAL) within the late endosomal/lysosomal (E/L) compartment. Then, through the successive actions of Niemann-Pick C2 (NPC2) and Niemann-Pick C1 (NPC1), unesterified cholesterol (UC) is exported from the E/L compartment to the cytosol. Mutations in either NPC1 or NPC2 lead to continuing entrapment of UC in all organs, resulting in multisystem disease which includes hepatic dysfunction and in some cases liver failure. These studies investigated primarily whether elimination of SOAT2 in NPC1-deficient mice impacted hepatic UC sequestration, inflammation, and transaminase activities. Measurements were made in 7 wk-old mice fed a low-cholesterol chow diet or one enriched with cholesterol starting 2 wk before study. In the chow-fed mice, NPC1:SOAT2 double knockouts, compared to their littermates lacking only NPC1, had 20% less liver mass, 28% lower hepatic UC concentrations, and plasma ALT and AST activities that were decreased by 48% and 36%, respectively. mRNA expression levels for several markers of inflammation were all significantly lower in the NPC1 mutants lacking SOAT2. The existence of a new class of potent and selective SOAT2 inhibitors provides an opportunity for exploring if suppression of this enzyme could potentially become an adjunctive therapy for liver disease in NPC1 deficiency.

  3. Honokiol Improves Liver Steatosis in Ovariectomized Mice

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    Yeon-Hui Jeong

    2018-01-01

    Full Text Available Nonalcoholic fatty liver disease (NAFLD is the most common liver disease, and is associated with the development of metabolic syndrome. Postmenopausal women with estrogen deficiency are at a higher risk of progression to NAFLD. Estrogen has a protective effect against the progression of the disease. Currently, there are no safe and effective treatments for these liver diseases in postmenopausal women. Honokiol (Ho, a bioactive natural product derived from Magnolia spp, has anti-inflammatory, anti-angiogenic, and anti-oxidative properties. In our study, we investigated the beneficial effects of Ho on NAFLD in ovariectomized (OVX mice. We divided the mice into four groups, as follows: SHAM, OVX, OVX+β-estradiol (0.4 mg/kg of bodyweight, and OVX+Ho (50 mg/kg of diet. Mice were fed diets with/without Ho for 12 weeks. The bodyweight, epidermal fat, and weights of liver tissue were lower in the OVX group than in the other groups. Ho improved hepatic steatosis and reduced proinflammatory cytokine levels. Moreover, Ho markedly downregulated plasma lipid levels. Our results indicate that Ho ameliorated OVX-induced fatty liver and inflammation, as well as associated lipid metabolism. These findings suggest that Ho may be hepatoprotective against NAFLD in postmenopausal women.

  4. Base excision repair deficient mice lacking the Aag alkyladenine DNA glycosylase.

    NARCIS (Netherlands)

    B.P. Engelward (Bevin); G. Weeda (Geert); M.D. Wyatt; J.L.M. Broekhof (Jose'); J. de Wit (Jan); I. Donker (Ingrid); J.M. Allan (James); B. Gold (Bert); J.H.J. Hoeijmakers (Jan); L.D. Samson (Leona)

    1997-01-01

    textabstract3-methyladenine (3MeA) DNA glycosylases remove 3MeAs from alkylated DNA to initiate the base excision repair pathway. Here we report the generation of mice deficient in the 3MeA DNA glycosylase encoded by the Aag (Mpg) gene. Alkyladenine DNA glycosylase turns out to be the major DNA

  5. Monocyte chemotactic protein-1 deficiency attenuates and high-fat diet exacerbates bone loss in mice with Lewis lung carcinoma.

    Science.gov (United States)

    Yan, Lin; Nielsen, Forrest H; Sundaram, Sneha; Cao, Jay

    2017-04-04

    Bone loss occurs in obesity and cancer-associated complications including wasting. This study determined whether a high-fat diet and a deficiency in monocyte chemotactic protein-1 (MCP-1) altered bone structural defects in male C57BL/6 mice with Lewis lung carcinoma (LLC) metastases in lungs. Compared to non-tumor-bearing mice, LLC reduced bone volume fraction, connectivity density, trabecular number, trabecular thickness and bone mineral density and increased trabecular separation in femurs. Similar changes occurred in vertebrae. The high-fat diet compared to the AIN93G diet exacerbated LLC-induced detrimental structural changes; the exacerbation was greater in femurs than in vertebrae. Mice deficient in MCP-1 compared to wild-type mice exhibited increases in bone volume fraction, connectivity density, trabecular number and decreases in trabecular separation in both femurs and vertebrae, and increases in trabecular thickness and bone mineral density and a decrease in structure model index in vertebrae. Lewis lung carcinoma significantly decreased osteocalcin but increased tartrate-resistant acid phosphatase 5b (TRAP 5b) in plasma. In LLC-bearing mice, the high-fat diet increased and MCP-1 deficiency decreased plasma TRAP 5b; neither the high-fat diet nor MCP-1 deficiency resulted in significant changes in plasma concentration of osteocalcin. In conclusion, pulmonary metastasis of LLC is accompanied by detrimental bone structural changes; MCP-1 deficiency attenuates and high-fat diet exacerbates the metastasis-associated bone wasting.

  6. Behavioral Characteristics of Ubiquitin-Specific Peptidase 46-Deficient Mice

    Science.gov (United States)

    Imai, Saki; Kano, Makoto; Nonoyama, Keiko; Ebihara, Shizufumi

    2013-01-01

    We have previously identified Usp46, which encodes for ubiquitin-specific peptidase 46, as a quantitative trait gene affecting the immobility time of mice in the tail suspension test (TST) and forced swimming test. The mutation that we identified was a 3-bp deletion coding for lysine (Lys 92), and mice with this mutation (MT mice), as well as Usp46 KO mice exhibited shorter TST immobility times. Behavioral pharmacology suggests that the gamma aminobutyric acid A (GABAA) receptor is involved in regulating TST immobility time. In order to understand how far Usp46 controls behavioral phenotypes, which could be related to mental disorders in humans, we subjected Usp46 MT and KO mice to multiple behavioral tests, including the open field test, ethanol preference test, ethanol-induced loss of righting reflex test, sucrose preference test, novelty-suppressed feeding test, marble burying test, and novel object recognition test. Although behavioral phenotypes of the Usp46 MT and KO mice were not always identical, deficiency of Usp46 significantly affected performance in all these tests. In the open field test, activity levels were lower in Usp46 KO mice than wild type (WT) or MT mice. Both MT and KO mice showed lower ethanol preference and shorter recovery times after ethanol administration. Compared to WT mice, Usp46 MT and KO mice exhibited decreased sucrose preference, took longer latency periods to bite pellets, and buried more marbles in the sucrose preference test, novelty-suppressed feeding test, and marble burying test, respectively. In the novel object recognition test, neither MT nor KO mice showed an increase in exploration of a new object 24 hours after training. These findings indicate that Usp46 regulates a wide range of behavioral phenotypes that might be related to human mental disorders and provides insight into the function of USP46 deubiquitinating enzyme in the neural system. PMID:23472206

  7. Behavioral characteristics of ubiquitin-specific peptidase 46-deficient mice.

    Directory of Open Access Journals (Sweden)

    Saki Imai

    Full Text Available We have previously identified Usp46, which encodes for ubiquitin-specific peptidase 46, as a quantitative trait gene affecting the immobility time of mice in the tail suspension test (TST and forced swimming test. The mutation that we identified was a 3-bp deletion coding for lysine (Lys 92, and mice with this mutation (MT mice, as well as Usp46 KO mice exhibited shorter TST immobility times. Behavioral pharmacology suggests that the gamma aminobutyric acid A (GABAA receptor is involved in regulating TST immobility time. In order to understand how far Usp46 controls behavioral phenotypes, which could be related to mental disorders in humans, we subjected Usp46 MT and KO mice to multiple behavioral tests, including the open field test, ethanol preference test, ethanol-induced loss of righting reflex test, sucrose preference test, novelty-suppressed feeding test, marble burying test, and novel object recognition test. Although behavioral phenotypes of the Usp46 MT and KO mice were not always identical, deficiency of Usp46 significantly affected performance in all these tests. In the open field test, activity levels were lower in Usp46 KO mice than wild type (WT or MT mice. Both MT and KO mice showed lower ethanol preference and shorter recovery times after ethanol administration. Compared to WT mice, Usp46 MT and KO mice exhibited decreased sucrose preference, took longer latency periods to bite pellets, and buried more marbles in the sucrose preference test, novelty-suppressed feeding test, and marble burying test, respectively. In the novel object recognition test, neither MT nor KO mice showed an increase in exploration of a new object 24 hours after training. These findings indicate that Usp46 regulates a wide range of behavioral phenotypes that might be related to human mental disorders and provides insight into the function of USP46 deubiquitinating enzyme in the neural system.

  8. Reversible skeletal abnormalities in gamma-glutamyl transpeptidase-deficient mice

    Science.gov (United States)

    Levasseur, Regis; Barrios, Roberto; Elefteriou, Florent; Glass, Donald A 2nd; Lieberman, Michael W.; Karsenty, Gerard

    2003-01-01

    Gamma-glutamyl transpeptidase (GGT) is a widely distributed ectopeptidase responsible for the degradation of glutathione in the gamma-glutamyl cycle. This cycle is implicated in the metabolism of cysteine, and absence of GGT causes a severe intracellular decrease in this amino acid. GGT-deficient (GGT-/-) mice have multiple metabolic abnormalities and are dwarf. We show here that this latter phenotype is due to a decreased of the growth plate cartilage total height resulting from a proliferative defect of chondrocytes. In addition, analysis of vertebrae and tibiae of GGT-/- mice revealed a severe osteopenia. Histomorphometric studies showed that this low bone mass phenotype results from an increased osteoclast number and activity as well as from a marked decrease in osteoblast activity. Interestingly, neither osteoblasts, osteoclasts, nor chondrocytes express GGT, suggesting that the observed defects are secondary to other abnormalities. N-acetylcysteine supplementation has been shown to reverse the metabolic abnormalities of the GGT-/- mice and in particular to restore the level of IGF-1 and sex steroids in these mice. Consistent with these previous observations, N-acetylcysteine treatment of GGT-/- mice ameliorates their skeletal abnormalities by normalizing chondrocytes proliferation and osteoblastic function. In contrast, resorbtion parameters are only partially normalized in GGT-/- N-acetylcysteine-treated mice, suggesting that GGT regulates osteoclast biology at least partly independently of these hormones. These results establish the importance of cysteine metabolism for the regulation of bone remodeling and longitudinal growth.

  9. Functional evolution of leptin of Ochotona curzoniae in adaptive thermogenesis driven by cold environmental stress.

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    Jie Yang

    Full Text Available BACKGROUND: Environmental stress can accelerate the directional selection and evolutionary rate of specific stress-response proteins to bring about new or altered functions, enhancing an organism's fitness to challenging environments. Plateau pika (Ochotona curzoniae, an endemic and keystone species on Qinghai-Tibetan Plateau, is a high hypoxia and low temperature tolerant mammal with high resting metabolic rate and non-shivering thermogenesis to cope in this harsh plateau environment. Leptin is a key hormone related to how these animals regulate energy homeostasis. Previous molecular evolutionary analysis helped to generate the hypothesis that adaptive evolution of plateau pika leptin may be driven by cold stress. METHODOLOGY/PRINCIPAL FINDINGS: To test the hypothesis, recombinant pika leptin was first purified. The thermogenic characteristics of C57BL/6J mice injected with pika leptin under warm (23±1°C and cold (5±1°C acclimation is investigated. Expression levels of genes regulating adaptive thermogenesis in brown adipose tissue and the hypothalamus are compared between pika leptin and human leptin treatment, suggesting that pika leptin has adaptively and functionally evolved. Our results show that pika leptin regulates energy homeostasis via reduced food intake and increased energy expenditure under both warm and cold conditions. Compared with human leptin, pika leptin demonstrates a superior induced capacity for adaptive thermogenesis, which is reflected in a more enhanced β-oxidation, mitochondrial biogenesis and heat production. Moreover, leptin treatment combined with cold stimulation has a significant synergistic effect on adaptive thermogenesis, more so than is observed with a single cold exposure or single leptin treatment. CONCLUSIONS/SIGNIFICANCE: These findings support the hypothesis that cold stress has driven the functional evolution of plateau pika leptin as an ecological adaptation to the Qinghai-Tibetan Plateau.

  10. Trichloroethylene exposure aggravates behavioral abnormalities in mice that are deficient in superoxide dismutase.

    Science.gov (United States)

    Otsuki, Noriyuki; Homma, Takujiro; Fujiwara, Hiroki; Kaneko, Kenya; Hozumi, Yasukazu; Shichiri, Mototada; Takashima, Mizuki; Ito, Junitsu; Konno, Tasuku; Kurahashi, Toshihiro; Yoshida, Yasukazu; Goto, Kaoru; Fujii, Satoshi; Fujii, Junichi

    2016-08-01

    Trichloroethylene (TCE) has been implicated as a causative agent for Parkinson's disease (PD). The administration of TCE to rodents induces neurotoxicity associated with dopaminergic neuron death, and evidence suggests that oxidative stress as a major player in the progression of PD. Here we report on TCE-induced behavioral abnormality in mice that are deficient in superoxide dismutase 1 (SOD1). Wild-type (WT) and SOD1-deficient (Sod1(-/-)) mice were intraperitoneally administered TCE (500 mg/kg) over a period of 4 weeks. Although the TCE-administrated Sod1(-/-) mice showed marked abnormal motor behavior, no significant differences were observed among the experimental groups by biochemical and histopathological analyses. However, treating mouse neuroblastoma-derived NB2a cells with TCE resulted in the down regulation of the SOD1 protein and elevated oxidative stress under conditions where SOD1 production was suppressed. Taken together, these data indicate that SOD1 plays a pivotal role in protecting motor neuron function against TCE toxicity. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. IGF-1 deficiency impairs neurovascular coupling in mice: implications for cerebromicrovascular aging.

    Science.gov (United States)

    Toth, Peter; Tarantini, Stefano; Ashpole, Nicole M; Tucsek, Zsuzsanna; Milne, Ginger L; Valcarcel-Ares, Noa M; Menyhart, Akos; Farkas, Eszter; Sonntag, William E; Csiszar, Anna; Ungvari, Zoltan

    2015-12-01

    Aging is associated with marked deficiency in circulating IGF-1, which has been shown to contribute to age-related cognitive decline. Impairment of moment-to-moment adjustment of cerebral blood flow (CBF) via neurovascular coupling is thought to play a critical role in the genesis of age-related cognitive impairment. To establish the link between IGF-1 deficiency and cerebromicrovascular impairment, neurovascular coupling mechanisms were studied in a novel mouse model of IGF-1 deficiency (Igf1(f/f) -TBG-Cre-AAV8) and accelerated vascular aging. We found that IGF-1-deficient mice exhibit neurovascular uncoupling and show a deficit in hippocampal-dependent spatial memory test, mimicking the aging phenotype. IGF-1 deficiency significantly impaired cerebromicrovascular endothelial function decreasing NO mediation of neurovascular coupling. IGF-1 deficiency also impaired glutamate-mediated CBF responses, likely due to dysregulation of astrocytic expression of metabotropic glutamate receptors and impairing mediation of CBF responses by eicosanoid gliotransmitters. Collectively, we demonstrate that IGF-1 deficiency promotes cerebromicrovascular dysfunction and neurovascular uncoupling mimicking the aging phenotype, which are likely to contribute to cognitive impairment. © 2015 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  12. Maternal Vitamin D Deficiency and Fetal Programming - Lessons Learned from Humans and Mice

    Directory of Open Access Journals (Sweden)

    Christoph Reichetzeder

    2014-09-01

    Full Text Available Background/Aims: Cardiovascular disease partially originates from poor environmental and nutritional conditions in early life. Lack of micronutrients like 25 hydroxy vitamin D3 (25OHD during pregnancy may be an important treatable causal factor. The present study explored the effect of maternal 25OHD deficiency on the offspring. Methods: We performed a prospective observational study analyzing the association of maternal 25OHD deficiency during pregnancy with birth outcomes considering confounding. To show that vitamin D deficiency may be causally involved in the observed associations, mice were set on either 25OHD sufficient or insufficient diets before and during pregnancy. Growth, glucose tolerance and mortality was analyzed in the F1 generation. Results: The clinical study showed that severe 25OHD deficiency was associated with low birth weight and low gestational age. ANCOVA models indicated that established confounding factors such as offspring sex, smoking during pregnancy and maternal BMI did not influence the impact of 25OHD on birth weight. However, there was a significant interaction between 25OHD and gestational age. Maternal 25OHD deficiency was also independently associated with low APGAR scores 5 minutes postpartum. The offspring of 25OHD deficient mice grew slower after birth, had an impaired glucose tolerance shortly after birth and an increased mortality during follow-up. Conclusions: Our study demonstrates an association between maternal 25OHD and offspring birth weight. The effect of 25OHD on birth weight seems to be mediated by vitamin D controlling gestational age. Results from an animal experiment suggest that gestational 25OHD insufficiency is causally linked to adverse pregnancy outcomes. Since birth weight and prematurity are associated with an adverse cardiovascular outcome in later life, this study emphasizes the need for novel monitoring and treatment guidelines of vitamin D deficiency during pregnancy.

  13. Dysregulation of Aldosterone Secretion in Mast Cell-Deficient Mice.

    Science.gov (United States)

    Boyer, Hadrien-Gaël; Wils, Julien; Renouf, Sylvie; Arabo, Arnaud; Duparc, Céline; Boutelet, Isabelle; Lefebvre, Hervé; Louiset, Estelle

    2017-12-01

    Resident adrenal mast cells have been shown to activate aldosterone secretion in rat and man. Especially, mast cell proliferation has been observed in adrenal tissues from patients with aldosterone-producing adrenocortical adenoma. In the present study, we show that the activity of adrenal mast cells is stimulated by low-sodium diet and correlates with aldosterone synthesis in C57BL/6 and BALB/c mice. We have also investigated the regulation of aldosterone secretion in mast cell-deficient C57BL/6 Kit W-sh/W-sh mice in comparison with wild-type C57BL/6 mice. Kit W-sh/W-sh mice submitted to normal sodium diet had basal plasma aldosterone levels similar to those observed in wild-type animals. Conversely, low-sodium diet unexpectedly induced an exaggerated aldosterone response, which seemed to result from an increase in adrenal renin and angiotensin type 1 receptor expression. Severe hyperaldosteronism was associated with an increase in systolic blood pressure and marked hypokalemia, which favored polyuria. Adrenal renin and angiotensin type 1 receptor overexpression may represent a compensatory mechanism aimed at activating aldosterone production in the absence of mast cells. Finally, C57BL/6 Kit W-sh/W-sh mice represent an unexpected animal model of primary aldosteronism, which has the particularity to be triggered by sodium restriction. © 2017 American Heart Association, Inc.

  14. Cardiac remodeling after myocardial infarction is impaired in IGF-1 deficient mice

    NARCIS (Netherlands)

    Palmen, M.; Daemen, M. J.; Bronsaer, R.; Dassen, W. R.; Zandbergen, H. R.; Kockx, M.; Smits, J. F.; van der Zee, R.; Doevendans, P. A.

    2001-01-01

    To obtain more insight in the role of IGF-1 in cardiac remodeling and function after experimental myocardial infarction. We hypothesized that cardiac remodeling is altered in IGF-1 deficient mice, which may affect cardiac function. A myocardial infarction was induced by surgical coronary artery

  15. Identifying activated T cells in reconstituted RAG deficient mice using retrovirally transduced Pax5 deficient pro-B cells.

    Directory of Open Access Journals (Sweden)

    Nadesan Gajendran

    Full Text Available Various methods have been used to identify activated T cells such as binding of MHC tetramers and expression of cell surface markers in addition to cytokine-based assays. In contrast to these published methods, we here describe a strategy to identify T cells that respond to any antigen and track the fate of these activated T cells. We constructed a retroviral double-reporter construct with enhanced green fluorescence protein (EGFP and a far-red fluorescent protein from Heteractis crispa (HcRed. LTR-driven EGFP expression was used to enrich and identify transduced cells, while HcRed expression is driven by the CD40Ligand (CD40L promoter, which is inducible and enables the identification and cell fate tracing of T cells that have responded to infection/inflammation. Pax5 deficient pro-B cells that can give rise to different hematopoietic cells like T cells, were retrovirally transduced with this double-reporter cassette and were used to reconstitute the T cell pool in RAG1 deficient mice that lack T and B cells. By using flow cytometry and histology, we identified activated T cells that had developed from Pax5 deficient pro-B cells and responded to infection with the bacterial pathogen Listeria monocytogenes. Microscopic examination of organ sections allowed visual identification of HcRed-expressing cells. To further characterize the immune response to a given stimuli, this strategy can be easily adapted to identify other cells of the hematopoietic system that respond to infection/inflammation. This can be achieved by using an inducible reporter, choosing the appropriate promoter, and reconstituting mice lacking cells of interest by injecting gene-modified Pax5 deficient pro-B cells.

  16. Vitamin E-deficiency did not exacerbate partial skin reactions in mice locally irradiated with X-rays

    International Nuclear Information System (INIS)

    Chi, C.; Hayashi, Daisuke; Nemoto, Masato; Nyui, Minako; Anzai, Kazunori; Urano, Shiro

    2011-01-01

    We previously showed that free radicals and oxidative stress are involved in radiation-induced skin reactions. Since vitamin E (VE) is a particularly important lipophilic antioxidant, VE-deficient mice were used to examine its effects on radiation-induced skin damage. The VE content of the skin was reduced to one fourth of levels of normal mice. Neither the time of onset nor the extent of the reactions quantified with a scoring system differed between normal and VE-deficient mice after local X-irradiation (50 Gy). Similarly, there was no difference in the levels of the ascorbyl radical between the groups, although they were higher in irradiated skin than non-irradiated skin. X-irradiation increased the amount of Bax protein in the skin of normal mice both in the latent and acute inflammatory stages, time- and dose-dependently. The increase was associated with an increase in cytochrome c in the cytosolic fraction, indicating that apoptosis was also promoted by the irradiation. The increase in Bax protein correlated well with the thickness of the skin. Although a deficiency in VE should lower resistance to free radicals in the mitochondrial membrane and thus enhance radiation-induced Bax expression and apoptosis, it actually attenuated the increase in Bax protein caused by irradiation. (author)

  17. Ghrelin and leptin interplay in prevention of testicular damage due to cryptochidism

    Science.gov (United States)

    Ghrelin, the endogenous ligand to the growth hormone secretagogue receptor (ghsr), is centrally implicated in body weight homeostasis. A novel murine model for ghrelin and its physiologic antagonist, leptin, was developed at this institution. Mice with a deletion of ghsr (ghsr -/-) or a targeted dis...

  18. Aberrant Muscle Antigen Exposure in Mice Is Sufficient to Cause Myositis in a Treg Cell–Deficient Milieu

    Science.gov (United States)

    Young, Nicholas A; Sharma, Rahul; Friedman, Alexandra K; Kaffenberger, Benjamin H; Bolon, Brad; Jarjour, Wael N

    2013-01-01

    Objective Myositis is associated with muscle-targeted inflammation and is observed in some Treg cell–deficient mouse models. Because an autoimmune pathogenesis has been strongly implicated, the aim of this study was to investigate the hypothesis that abnormal exposure to muscle antigens, as observed in muscle injury, can induce autoimmune-mediated myositis in susceptible hosts. Methods FoxP3 mutant (scurfy) mice were mated to synaptotagmin VII (Syt VII) mutant mice, which resulted in a new mouse strain that combines impaired membrane resealing with Treg cell deficiency. Lymphocyte preparations from double-mutant mice were adoptively transferred intraperitoneally, with or without purified Treg cells, into recombination-activating gene 1 (RAG-1)–null recipients. Lymph node cells from mice with the FoxP3 mutation were transferred into RAG-1–null mice either 1) intraperitoneally in conjunction with muscle homogenate or purified myosin protein or 2) intramuscularly with or without cotransfer of purified Treg cells. Results FoxP3-deficient mouse lymph node cells transferred in conjunction with myosin protein or muscle homogenate induced robust skeletal muscle inflammation. The infiltrates consisted predominantly of CD4+ and CD8+ T cells, a limited number of macrophages, and no B cells. Significant inflammation was also seen in similar experiments using lymph node cells from FoxP3/Syt VII double-mutant mice but was absent in experiments using adoptive transfer of FoxP3 mutant mouse cells alone. The cotransfer of Treg cells completely suppressed myositis. Conclusion These data, derived from a new, reproducible model, demonstrate the critical roles of Treg cell deficiency and aberrant muscle antigen exposure in the priming of autoreactive cells to induce myositis. This mouse system has multifaceted potential for examining the interplay in vivo between tissue injury and autoimmunity. PMID:24022275

  19. Na(v)1.8 channelopathy in mutant mice deficient for myelin protein zero is detrimental to motor axons

    DEFF Research Database (Denmark)

    Moldovan, Mihai; Alvarez Herrero, Susana; Pinchenko, Volodymyr

    2011-01-01

    Myelin protein zero mutations were found to produce Charcot-Marie-Tooth disease phenotypes with various degrees of myelin impairment and axonal loss, ranging from the mild 'demyelinating' adult form to severe and early onset forms. Protein zero deficient homozygous mice ( ) show a severe and prog......Myelin protein zero mutations were found to produce Charcot-Marie-Tooth disease phenotypes with various degrees of myelin impairment and axonal loss, ranging from the mild 'demyelinating' adult form to severe and early onset forms. Protein zero deficient homozygous mice ( ) show a severe...... and progressive dysmyelinating neuropathy from birth with compromised myelin compaction, hypomyelination and distal axonal degeneration. A previous study using immunofluorescence showed that motor nerves deficient of myelin protein zero upregulate the Na(V)1.8 voltage gated sodium channel isoform, which...... is normally present only in restricted populations of sensory axons. The aim of this study was to investigate the function of motor axons in protein zero-deficient mice with particular emphasis on ectopic Na(V)1.8 voltage gated sodium channel. We combined 'threshold tracking' excitability studies...

  20. Growth hormone abolishes beneficial effects of calorie restriction in long-lived Ames dwarf mice.

    Science.gov (United States)

    Gesing, Adam; Al-Regaiey, Khalid A; Bartke, Andrzej; Masternak, Michal M

    2014-10-01

    Disruption of the growth hormone (GH) axis promotes longevity and delays aging. In contrast, GH over-expression may lead to accelerated aging and shorter life. Calorie restriction (CR) improves insulin sensitivity and may extend lifespan. Long-lived Ames dwarf (df/df) mice have additional extension of longevity when subjected to 30% CR. The aim of the study was to assess effects of CR or GH replacement therapy separately and as a combined (CR+GH) treatment in GH-deficient df/df and normal mice, on selected metabolic parameters (e.g., insulin, glucose, cholesterol), insulin signaling components (e.g., insulin receptor [IR] β-subunit, phosphorylated form of IR [IR pY1158], protein kinase C ζ/λ [p-PKCζ/λ] and mTOR [p-mTOR]), transcription factor p-CREB, and components of the mitogen-activated protein kinase (MAPK) signaling (p-ERK1/2, p-p38), responsible for cell proliferation, differentiation and survival. CR decreased plasma levels of insulin, glucose, cholesterol and leptin, and increased hepatic IR β-subunit and IR pY1158 levels as well as IR, IRS-1 and GLUT-2 gene expression compared to ad libitum feeding, showing a significant beneficial diet intervention effect. Moreover, hepatic protein levels of p-PKCζ/λ, p-mTOR and p-p38 decreased, and p-CREB increased in CR mice. On the contrary, GH increased levels of glucose, cholesterol and leptin in plasma, and p-mTOR or p-p38 in livers, and decreased plasma adiponectin and hepatic IR β-subunit compared to saline treatment. There were no GH effects on adiponectin in N mice. Moreover, GH replacement therapy did not affect IR, IRS-1 and GLUT-2 gene expression. GH treatment abolishes the beneficial effects of CR; it may suggest an important role of GH-IGF1 axis in mediating the CR action. Suppressed somatotrophic signaling seems to predominate over GH replacement therapy in the context of the examined parameters and signaling pathways. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Effect of Lowering Asymmetric Dimethylarginine (ADMA on Vascular Pathology in Atherosclerotic ApoE-Deficient Mice with Reduced Renal Mass

    Directory of Open Access Journals (Sweden)

    Johannes Jacobi

    2014-03-01

    Full Text Available The purpose of the work was to study the impact of the endogenous nitric oxide synthase (NOS inhibitor asymmetric dimethylarginine (ADMA and its degrading enzyme, dimethylarginine dimethylaminohydrolase (DDAH1, on atherosclerosis in subtotally nephrectomized (SNX ApoE-deficient mice. Male DDAH1 transgenic mice (TG, n = 39 and C57Bl/6J wild-type littermates (WT, n = 27 with or without the deletion of the ApoE gene underwent SNX at the age of eight weeks. Animals were sacrificed at 12 months of age, and blood chemistry, as well as the extent of atherosclerosis within the entire aorta were analyzed. Sham treated (no renal mass reduction ApoE-competent DDAH1 transgenic and wild-type littermates (n = 11 served as a control group. Overexpression of DDAH1 was associated with significantly lower ADMA levels in all treatment groups. Surprisingly, SNX mice did not exhibit higher ADMA levels compared to sham treated control mice. Furthermore, the degree of atherosclerosis in ApoE-deficient mice with SNX was similar in mice with or without overexpression of DDAH1. Overexpression of the ADMA degrading enzyme, DDAH1, did not ameliorate atherosclerosis in ApoE-deficient SNX mice. Furthermore, SNX in mice had no impact on ADMA levels, suggesting a minor role of this molecule in chronic kidney disease (CKD in this mouse model.

  2. The effect of iron-deficiency anemia on cytolytic activity of mice spleen and peritoneal cells against allogenic tumor cells

    International Nuclear Information System (INIS)

    Kuvibidila, S.R.; Baliga, B.S.; Suskind, R.M.

    1983-01-01

    The capacity of spleen and peritoneal cells from iron deficient mice, ad libitum fed control mice, and pair-fed mice to kill allogenic tumor cells (mastocytoma tumor P815) has been investigated. In the first study, mice were sensitized in vivo with 10(7) viable tumor cells 51 and 56 days after weaning. The capacity of splenic cells and peritoneal cells from sensitized and nonsensitized mice to kill tumor cells was evaluated 5 days after the second dose of tumor cells. At ratios of 2.5:1 to 100:1 of attacker to target cells, the percentage 51 Cr release after 4 h of incubation was significantly less in iron-deficient mice than control and/or pair-fed mice (p less than 0.05). Protein-energy undernutrition in pair-fed mice had no significant effect. In the second study, spleen cells and enriched T cell fractions were incubated in vitro for 5 days with uv irradiated Balb/C spleen cells in a 2:1 ratio. The cytotoxic capacity against the same allogenic tumor cells was again evaluated. The percentage chromium release at different attacker to target cells was less than 30% in the iron-deficient group compared to either control or pair-fed supporting the results of in vivo sensitized cells. The possible mode of impairment of the cytotoxic capacity is discussed

  3. Neuronal SH2B1 is essential for controlling energy and glucose homeostasis.

    Science.gov (United States)

    Ren, Decheng; Zhou, Yingjiang; Morris, David; Li, Minghua; Li, Zhiqin; Rui, Liangyou

    2007-02-01

    SH2B1 (previously named SH2-B), a cytoplasmic adaptor protein, binds via its Src homology 2 (SH2) domain to a variety of protein tyrosine kinases, including JAK2 and the insulin receptor. SH2B1-deficient mice are obese and diabetic. Here we demonstrated that multiple isoforms of SH2B1 (alpha, beta, gamma, and/or delta) were expressed in numerous tissues, including the brain, hypothalamus, liver, muscle, adipose tissue, heart, and pancreas. Rat SH2B1beta was specifically expressed in neural tissue in SH2B1-transgenic (SH2B1(Tg)) mice. SH2B1(Tg) mice were crossed with SH2B1-knockout (SH2B1(KO)) mice to generate SH2B1(TgKO) mice expressing SH2B1 only in neural tissue but not in other tissues. Systemic deletion of the SH2B1 gene resulted in metabolic disorders in SH2B1(KO) mice, including hyperlipidemia, leptin resistance, hyperphagia, obesity, hyperglycemia, insulin resistance, and glucose intolerance. Neuron-specific restoration of SH2B1beta not only corrected the metabolic disorders in SH2B1(TgKO) mice, but also improved JAK2-mediated leptin signaling and leptin regulation of orexigenic neuropeptide expression in the hypothalamus. Moreover, neuron-specific overexpression of SH2B1 dose-dependently protected against high-fat diet-induced leptin resistance and obesity. These observations suggest that neuronal SH2B1 regulates energy balance, body weight, peripheral insulin sensitivity, and glucose homeostasis at least in part by enhancing hypothalamic leptin sensitivity.

  4. Morphological study of tooth development in podoplanin-deficient mice.

    Directory of Open Access Journals (Sweden)

    Kenyo Takara

    Full Text Available Podoplanin is a mucin-type highly O-glycosylated glycoprotein identified in several somatyic cells: podocytes, alveolar epithelial cells, lymphatic endothelial cells, lymph node stromal fibroblastic reticular cells, osteocytes, odontoblasts, mesothelial cells, glia cells, and others. It has been reported that podoplanin-RhoA interaction induces cytoskeleton relaxation and cell process stretching in fibroblastic cells and osteocytes, and that podoplanin plays a critical role in type I alveolar cell differentiation. It appears that podoplanin plays a number of different roles in contributing to cell functioning and growth by signaling. However, little is known about the functions of podoplanin in the somatic cells of the adult organism because an absence of podoplanin is lethal at birth by the respiratory failure. In this report, we investigated the tooth germ development in podoplanin-knockout mice, and the dentin formation in podoplanin-conditional knockout mice having neural crest-derived cells with deficiency in podoplanin by the Wnt1 promoter and enhancer-driven Cre recombinase: Wnt1-Cre;PdpnΔ/Δmice. In the Wnt1-Cre;PdpnΔ/Δmice, the tooth and alveolar bone showed no morphological abnormalities and grow normally, indicating that podoplanin is not critical in the development of the tooth and bone.

  5. Morphological study of tooth development in podoplanin-deficient mice.

    Science.gov (United States)

    Takara, Kenyo; Maruo, Naoki; Oka, Kyoko; Kaji, Chiaki; Hatakeyama, Yuji; Sawa, Naruhiko; Kato, Yukinari; Yamashita, Junro; Kojima, Hiroshi; Sawa, Yoshihiko

    2017-01-01

    Podoplanin is a mucin-type highly O-glycosylated glycoprotein identified in several somatyic cells: podocytes, alveolar epithelial cells, lymphatic endothelial cells, lymph node stromal fibroblastic reticular cells, osteocytes, odontoblasts, mesothelial cells, glia cells, and others. It has been reported that podoplanin-RhoA interaction induces cytoskeleton relaxation and cell process stretching in fibroblastic cells and osteocytes, and that podoplanin plays a critical role in type I alveolar cell differentiation. It appears that podoplanin plays a number of different roles in contributing to cell functioning and growth by signaling. However, little is known about the functions of podoplanin in the somatic cells of the adult organism because an absence of podoplanin is lethal at birth by the respiratory failure. In this report, we investigated the tooth germ development in podoplanin-knockout mice, and the dentin formation in podoplanin-conditional knockout mice having neural crest-derived cells with deficiency in podoplanin by the Wnt1 promoter and enhancer-driven Cre recombinase: Wnt1-Cre;PdpnΔ/Δmice. In the Wnt1-Cre;PdpnΔ/Δmice, the tooth and alveolar bone showed no morphological abnormalities and grow normally, indicating that podoplanin is not critical in the development of the tooth and bone.

  6. Indomethacin induced gastropathy in CD18, intercellular adhesion molecule 1, or P-selectin deficient mice

    Science.gov (United States)

    Morise, Z; Granger, D; Fuseler, J; Anderson, D; Grisham, M

    1999-01-01

    BACKGROUND—Neutrophil-endothelial cell interactions are thought to play a critical role in the pathophysiology of non-steroidal anti-inflammatory drug (NSAID) induced gastropathy.
AIMS—To optimise a mouse model of NSAID induced gastropathy and to evaluate the importance of adhesion molecules using adhesion molecule deficient mice.
METHODS—Gastropathy was induced in C57BL/6 mice or their adhesion molecule deficient counterparts via oral administration of indomethacin (20 mg/kg). Lesion scores, mucosal permeability, and histopathology were used to assess gastric mucosal injury.
RESULTS—Intragastric administration of indomethacin induced linear haemorrhagic mucosal lesions, primarily in the corpus of the stomach that were first observed at six hours. These lesions continued to develop over the next six hours with maximal lesion scores and mucosal permeabilities at 12 hours. When indomethacin was administered to mice deficient in CD18, intercellular adhesion molecule 1 (ICAM-1), or P-selectin, there were significant decreases in lesion scores compared with their C57BL/6 controls. In addition, mucosal permeabilities were found to be significantly lower in CD18 or ICAM-1 deficient mice observed at 12 hours.
CONCLUSION—Certain leucocyte and endothelial cell adhesion molecules are important determinants for full expression of indomethacin induced gastropathy. It is proposed that this modification of the mouse model may be useful for the investigation of other pathophysiological mechanisms of NSAID induced gastropathy.


Keywords: indomethacin; gastropathy; cyclooxygenase; intercellular adhesion molecule; VCAM; vascular cell adhesion molecule; P-selectin PMID:10486359

  7. Leptin responsiveness to energy restriction: genetic variation in the leptin receptor gene

    NARCIS (Netherlands)

    Mars, M.; Rossum, van C.T.M.; Graaf, de C.; Hoebee, B.; Groot, de C.P.G.M.; Kok, F.J.

    2004-01-01

    Serum leptin concentrations are an important afferent signal in energy balance homeostasis. It has been speculated that the leptin responsiveness to energy restriction is affected by the functionality of the leptin receptor. The purpose of this analysis was to explore the effect of polymorphisms in

  8. Genomic instability in mice is greater in Fanconi anemia caused by deficiency of Fancd2 than Fancg.

    Science.gov (United States)

    Reliene, Ramune; Yamamoto, Mitsuko L; Rao, P Nagesh; Schiestl, Robert H

    2010-12-01

    Fanconi anemia (FA) results from mutations in the FANC genes and is characterized by bone marrow failure, birth defects, and a high incidence of cancer. FANCG is a part of the FA core complex that is responsible for monoubiquitination of FANCD2 and FANCI. The precise role of the FA pathway is not well understood, although it may be involved in homologous recombination (HR), nonhomologous end joining, and translesion synthesis (TLS). Fancd2(-/-) mice have a more severe phenotype than Fancg(-/-), and other FA core complex-deficient mice, although both Fancg and Fancd2 belong to the same FA pathway. We hypothesized that Fancd2 deficiency results in a more severe phenotype because Fancd2 also has a FA pathway-independent function in the maintenance of genomic integrity. To test this hypothesis, we determined the level of DNA damage and genomic instability in Fancd2(-/-), Fancg(-/-), and wild-type controls. Fancd2(-/-) mice displayed a higher magnitude of chromosomal breakage and micronucleus formation than the wild-type or Fancg(-/-) mice. Also, DNA strand breaks were increased in Fancd2(-/-) but not in Fancg(-/-) mice. In addition, Fancd2(-/-) mice displayed an elevated frequency of DNA deletions, resulting from HR at the endogenous p(un) locus. In contrast, in Fancg(-/-) mice, the frequency of DNA deletions was decreased. Thus, Fancd2 but not Fancg deficiency results in elevated chromosomal/DNA breakage and permanent genome rearrangements. This provides evidence that Fancd2 plays an additional role in the maintenance of genomic stability than Fancg, which might explain the higher predisposition to cancer seen in the Fancd2(-/-) mice.

  9. Gene therapy/bone marrow transplantation in ADA-deficient mice: roles of enzyme-replacement therapy and cytoreduction

    Science.gov (United States)

    Jin, Xiangyang; Wang, Xingchao; Yu, Xiao-Jin; Rozengurt, Nora; Kaufman, Michael L.; Wang, Xiaoyan; Gjertson, David; Zhou, Yang; Blackburn, Michael R.; Kohn, Donald B.

    2012-01-01

    Gene therapy (GT) for adenosine deaminase–deficient severe combined immune deficiency (ADA-SCID) can provide significant long-term benefit when patients are given nonmyeloablative conditioning and ADA enzyme-replacement therapy (ERT) is withheld before autologous transplantation of γ-retroviral vector-transduced BM CD34+ cells. To determine the contributions of conditioning and discontinuation of ERT to the therapeutic effects, we analyzed these factors in Ada gene knockout mice (Ada−/−). Mice were transplanted with ADA-deficient marrow transduced with an ADA-expressing γ-retroviral vector without preconditioning or after 200 cGy or 900 cGy total-body irradiation and evaluated after 4 months. In all tissues analyzed, vector copy numbers (VCNs) were 100- to 1000-fold greater in mice receiving 900 cGy compared with 200 cGy (P < .05). In mice receiving 200 cGy, VCN was similar whether ERT was stopped or given for 1 or 4 months after GT. In unconditioned mice, there was decreased survival with and without ERT, and VCN was very low to undetectable. When recipients were conditioned with 200 cGy and received transduced lineage-depleted marrow, only recipients receiving ERT (1 or 4 months) had detectable vector sequences in thymocytes. In conclusion, cytoreduction is important for the engraftment of gene-transduced HSC, and short-term ERT after GT did not diminish the capacity of gene-corrected cells to engraft and persist. PMID:22833548

  10. Mice with Sort1 deficiency display normal cognition but elevated anxiety-like behavior.

    Science.gov (United States)

    Ruan, Chun-Sheng; Yang, Chun-Rui; Li, Jia-Yi; Luo, Hai-Yun; Bobrovskaya, Larisa; Zhou, Xin-Fu

    2016-07-01

    Exposure to stressful life events plays a central role in the development of mood disorders in vulnerable individuals. However, the mechanisms that link mood disorders to stress are poorly understood. Brain-derived neurotrophic factor (BDNF) has long been implicated in positive regulation of depression and anxiety, while its precursor (proBDNF) recently showed an opposing effect on such mental illnesses. P75(NTR) and sortilin are co-receptors of proBDNF, however, the role of these receptors in mood regulation is not established. Here, we aimed to investigate the role of sortilin in regulating mood-related behaviors and its role in the proBDNF-mediated mood abnormality in mice. We found that sortilin was up-regulated in neocortex (by 78.3%) and hippocampus (by 111%) of chronically stressed mice as assessed by western blot analysis. These changes were associated with decreased mobility in the open field test and increased depression-like behavior in the forced swimming test. We also found that sortilin deficiency in mice resulted in hyperlocomotion in the open field test and increased anxiety-like behavior in both the open field and elevated plus maze tests. No depression-like behavior in the forced swimming test and no deficit in spatial cognition in the Morris water maze test were found in the Sort1-deficient mice. Moreover, the intracellular and extracellular levels of mature BDNF and proBDNF were not changed when sortilin was absent in vivo and in vitro. Finally, we found that both WT and Sort1-deficient mice injected with proBDNF in lateral ventricle displayed increased depression-like behavior in the forced swimming test but not anxiety-like behaviors in the open field and elevated plus maze tests. The present study suggests that sortilin functions as a negative regulator of mood performance and can be a therapeutic target for the treatment of mental illness. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

  11. Transient impairment of the adaptive response to fasting in FXR-deficient mice

    NARCIS (Netherlands)

    Cariou, B; van Harmelen, K; Duran-Sandoval, D; van Dijk, T; Grefhorst, A; Bouchaert, E; Fruchart, JC; Gonzalez, FJ; Kuipers, F; Staels, B

    2005-01-01

    The farnesoid X receptor (FXR) has been suggested to play a role in gluconeogenesis. To determine whether FXR modulates the response to fasting in vivo, FXR-deficient (FXR-/-) and wild-type mice were submitted to fasting for 48 h. Our results demonstrate that FXR modulates the kinetics of

  12. PKA-RIIB Deficiency Induces Brown Fatlike Adipocytes in Inguinal WAT and Promotes Energy Expenditure in Male FVB/NJ Mice.

    Science.gov (United States)

    Su, Jing; Wu, Wei; Huang, Shan; Xue, Ruidan; Wang, Yi; Wan, Yun; Zhang, Lv; Qin, Lang; Zhang, Qiongyue; Zhu, Xiaoming; Zhang, Zhaoyun; Ye, Hongying; Wu, Xiaohui; Li, Yiming

    2017-03-01

    Obesity has become the most common metabolic disorder worldwide. Promoting brown adipose tissue (BAT) and beige adipose tissue formation, and therefore, a functional increase in energy expenditure, may counteract obesity. Mice lacking type IIβ regulatory subunit of adenosine 3',5' cyclic monophosphate (cAMP)-dependent protein kinase A (PKA-RIIB) display reduced adiposity and resistance to diet-induced obesity. PKA-RIIB, encoded by the Prkar2b gene, is most abundant in BAT and white adipose tissue (WAT) and in the brain. In this study, we show that mice lacking PKA-RIIB have increased energy expenditure, limited weight gain, and improved glucose metabolism. PKA-RIIB deficiency induces brownlike adipocyte in inguinal WAT (iWAT). PKA-RIIB deficiency also increases the expression of uncoupling protein 1 and other thermogenic genes in iWAT and primary preadipocytes from iWAT through a mechanism involving increased PKA activity, which is represented by increased phosphorylation of PKA substrate, cAMP response element binding protein, and P38 mitogen-activated protein kinase. Our study provides evidence for the role of PKA-RIIB deficiency in regulating thermogenesis in WAT, which may potentially have therapeutic implications for the treatment of obesity and related metabolic disorders. Copyright © 2017 by the Endocrine Society.

  13. The administration of long-term high-fat diet in ovariectomized wistar rat (Study on Daily Food Intake, Lee Index, Abdominal Fat Mass and Leptin Serum Levels)

    OpenAIRE

    Fitriani, Dita; Meliala, Andreanyta; Agustiningsih, Denny

    2016-01-01

    Background: Leptin and estrogen are the hormone that has an important function in energy homeostasis through anorexic effects on the central nervous system. Leptin and estrogen action can decrease food intake, increases energy expenditure and thermogenesis. However, the administration of long-term high-fat diet can lead to impaired leptin function. In addition, estrogen deficiency is also considered a risk factor that may increase the occurrence of obesity in menopause. Objective: This st...

  14. PPARγ ablation sensitizes proopiomelanocortin neurons to leptin during high-fat feeding.

    Science.gov (United States)

    Long, Lihong; Toda, Chitoku; Jeong, Jing Kwon; Horvath, Tamas L; Diano, Sabrina

    2014-09-01

    Activation of central PPARγ promotes food intake and body weight gain; however, the identity of the neurons that express PPARγ and mediate the effect of this nuclear receptor on energy homeostasis is unknown. Here, we determined that selective ablation of PPARγ in murine proopiomelanocortin (POMC) neurons decreases peroxisome density, elevates reactive oxygen species, and induces leptin sensitivity in these neurons. Furthermore, ablation of PPARγ in POMC neurons preserved the interaction between mitochondria and the endoplasmic reticulum, which is dysregulated by HFD. Compared with control animals, mice lacking PPARγ in POMC neurons had increased energy expenditure and locomotor activity; reduced body weight, fat mass, and food intake; and improved glucose metabolism when exposed to high-fat diet (HFD). Finally, peripheral administration of either a PPARγ activator or inhibitor failed to affect food intake of mice with POMC-specific PPARγ ablation. Taken together, our data indicate that PPARγ mediates cellular, biological, and functional adaptations of POMC neurons to HFD, thereby regulating whole-body energy balance.

  15. Suppressive effects of cacao polyphenols on the development of atherosclerosis in apolipoprotein E-deficient mice.

    Science.gov (United States)

    Natsume, Midori; Baba, Seigo

    2014-01-01

    Previous studies in humans have shown that the cacao polyphenols, (-)-epicatechin and its oligomers, prevent in vitro and ex vivo low-density lipoprotein oxidation mediated by free radical generators and metal ions and also reduce plasma LDL-cholesterol levels. The aim of this study was to examine the effects of cacao polyphenols on the development of atherosclerosis in apolipoprotein E-deficient (-/-) mice. Mice aged 8 weeks (n = 90) were randomized into three groups, and fed either normal mouse chow (controls) or chow supplemented with 0.25 or 0.40 % cacao polyphenols for 16 weeks. The mean plaque area in cross-sections of the brachiocephalic trunk was measured and found to be lower in the 0.25 % cacao polyphenol group than in the control group (p cacao polyphenol group (p cacao polyphenols inhibit the development of atherosclerosis in apolipoprotein E-deficient (-/-) mice by reducing oxidative stress and inflammatory responses.

  16. Physical training improves body weight and energy balance but does not protect against hepatic steatosis in obese mice.

    Science.gov (United States)

    Evangelista, Fabiana S; Muller, Cynthia R; Stefano, Jose T; Torres, Mariana M; Muntanelli, Bruna R; Simon, Daniel; Alvares-da-Silva, Mario R; Pereira, Isabel V; Cogliati, Bruno; Carrilho, Flair J; Oliveira, Claudia P

    2015-01-01

    This study sought to determine the role of physical training (PT) on body weight (BW), energy balance, histological markers of nonalcoholic fatty liver disease (NAFLD) and metabolic gene expression in the liver of ob/ob mice. Adult male ob/ob mice were assigned into groups sedentary (S; n = 8) and trained (T; n = 9). PT consisted in running sessions of 60 min at 60% of maximal speed conducted five days per week for eight weeks. BW of S group was higher from the 4(th) to 8(th) week of PT compared to their own BW at the beginning of the experiment. PT decreased daily food intake and increased resting oxygen consumption and energy expenditure in T group. No difference was observed in respiratory exchange ratio, but the rates of carbohydrate and lipids oxidation, and maximal running capacity were greater in T than S group. Both groups showed liver steatosis but not inflammation. PT increased CPT1a and SREBP1c mRNA expression in T group, but did not change MTP, PPAR-α, PPAR-γ, and NFKB mRNA expression. In conclusion, PT prevented body weight gain in ob/ob mice by inducing negative energy balance and increased physical exercise tolerance. However, PT did not change inflammatory gene expression and failed to prevent liver steatosis possible due to an upregulation in the expression of SREBP1c transcription factor. These findings reveal that PT has positive effect on body weight control but not in the liver steatosis in a leptin deficiency condition.

  17. Leptin signaling in GABA neurons, but not glutamate neurons, is required for reproductive function.

    Science.gov (United States)

    Zuure, Wieteke A; Roberts, Amy L; Quennell, Janette H; Anderson, Greg M

    2013-11-06

    The adipocyte-derived hormone leptin acts in the brain to modulate the central driver of fertility: the gonadotropin releasing hormone (GnRH) neuronal system. This effect is indirect, as GnRH neurons do not express leptin receptors (LEPRs). Here we test whether GABAergic or glutamatergic neurons provide the intermediate pathway between the site of leptin action and the GnRH neurons. Leptin receptors were deleted from GABA and glutamate neurons using Cre-Lox transgenics, and the downstream effects on puberty onset and reproduction were examined. Both mouse lines displayed the expected increase in body weight and region-specific loss of leptin signaling in the hypothalamus. The GABA neuron-specific LEPR knock-out females and males showed significantly delayed puberty onset. Adult fertility observations revealed that these knock-out animals have decreased fecundity. In contrast, glutamate neuron-specific LEPR knock-out mice displayed normal fertility. Assessment of the estrogenic hypothalamic-pituitary-gonadal axis regulation in females showed that leptin action on GABA neurons is not necessary for estradiol-mediated suppression of tonic luteinizing hormone secretion (an indirect measure of GnRH neuron activity) but is required for regulation of a full preovulatory-like luteinizing hormone surge. In conclusion, leptin signaling in GABAergic (but not glutamatergic neurons) plays a critical role in the timing of puberty onset and is involved in fertility regulation throughout adulthood in both sexes. These results form an important step in explaining the role of central leptin signaling in the reproductive system. Limiting the leptin-to-GnRH mediators to GABAergic cells will enable future research to focus on a few specific types of neurons.

  18. Aromatase deficiency causes altered expression of molecules critical for calcium reabsorption in the kidneys of female mice *.

    NARCIS (Netherlands)

    Oz, O.K.; Hajibeigi, A.; Howard, K.; Cummins, C.L.; Abel, M. van; Bindels, R.J.M.; Word, R.A.; Kuro-o, M.; Pak, C.Y.; Zerwekh, J.E.

    2007-01-01

    Kidney stones increase after menopause, suggesting a role for estrogen deficiency. ArKO mice have hypercalciuria and lower levels of calcium transport proteins, whereas levels of the klotho protein are elevated. Thus, estrogen deficiency is sufficient to cause altered renal calcium handling.

  19. Gene Expression of Leptin and Long Leptin Receptor Isoform in Endometriosis: A Case-Control Study

    Directory of Open Access Journals (Sweden)

    Andrea Prestes Nácul

    2013-01-01

    Full Text Available In this study, leptin/BMI ratio in serum and peritoneal fluid and gene expression of leptin and long form leptin receptor (OB-RL were assessed in eutopic and ectopic endometria of women with endometriosis and controls. Increased serum leptin/BMI ratio was found in endometriosis patients. Leptin and OB-RL gene expression was significantly higher in ectopic versus eutopic endometrium of patients and controls. A positive, significant correlation was observed between leptin and OB-RL transcripts in ectopic endometria and also in eutopic endometria in endometriosis and control groups. A negative and significant correlation was found between OB-RL mRNA expression and peritoneal fluid leptin/BMI ratio only in endometriosis. These data suggest that, through a modulatory interaction with its active receptor, leptin might play a role in the development of endometrial implants.

  20. The role of CD4+ T cells in cell-mediated immunity to LCMV: studies in MHC class I and class II deficient mice

    DEFF Research Database (Denmark)

    Christensen, Jan Pravsgaard; Marker, O; Thomsen, Allan Randrup

    1994-01-01

    Parameters of the virus-specific T-cell response were analysed in order to dissect the contribution of CD4+ and CD8+ T cells to cell-mediated immunity to lymphocytic choriomeningitis virus. In MHC class II deficient mice, initial T-cell responsiveness was not impaired, but virus clearance...... was delayed, and virus-specific Td activity declined more rapidly. Furthermore, class I restricted Tc memory appeared to be impaired in these mice. To directly evaluate the role of CD4+ cells in virus clearance and T-cell mediated inflammation, MHC class I deficient mice were also studied. No virus...... exudate. This low-grade response was associated with some degree of virus control as organ titres were lower in these animals than in matched T-cell deficient nu/nu mice or class I deficient mice treated with anti-CD4 monoclonal antibody. This confirms that CD4+ cells are not needed to induce a virus...

  1. Impact of PACAP and PAC1 receptor deficiency on the neurochemical and behavioral effects of acute and chronic restraint stress in male C57BL/6 mice.

    Science.gov (United States)

    Mustafa, Tomris; Jiang, Sunny Zhihong; Eiden, Adrian M; Weihe, Eberhard; Thistlethwaite, Ian; Eiden, Lee E

    2015-01-01

    Acute restraint stress (ARS) for 3 h causes corticosterone (CORT) elevation in venous blood, which is accompanied by Fos up-regulation in the paraventricular nucleus (PVN) of male C57BL/6 mice. CORT elevation by ARS is attenuated in PACAP-deficient mice, but unaffected in PAC1-deficient mice. Correspondingly, Fos up-regulation by ARS is greatly attenuated in PACAP-deficient mice, but much less so in PAC1-deficient animals. We noted that both PACAP- and PAC1-deficiency greatly attenuate CORT elevation after ARS when CORT measurements are performed on trunk blood following euthanasia by abrupt cervical separation: this latter observation is of critical importance in assessing the role of PACAP neurotransmission in ARS, based on previous reports in which serum CORT was sampled from trunk blood. Seven days of chronic restraint stress (CRS) induces non-habituating CORT elevation, and weight loss consequent to hypophagia, in wild-type male C57BL/6 mice. Both CORT elevation and weight loss following 7-day CRS are severely blunted in PACAP-deficient mice, but only slightly in PAC1-deficient mice. However, longer periods of daily restraint (14-21 days) resulted in sustained weight loss and elevated CORT in wild-type mice, and these effects of long-term chronic stress were attenuated or abolished in both PACAP- and PAC1-deficient mice. We conclude that while a PACAP receptor in addition to PAC1 may mediate some of the PACAP-dependent central effects of ARS and short-term (7 days) CRS.

  2. High circulatory leptin mediated NOX-2-peroxynitrite-miR21 axis activate mesangial cells and promotes renal inflammatory pathology in nonalcoholic fatty liver disease

    Directory of Open Access Journals (Sweden)

    Firas Alhasson

    2018-07-01

    Full Text Available High circulatory insulin and leptin followed by underlying inflammation are often ascribed to the ectopic manifestations in non-alcoholic fatty liver disease (NAFLD but the exact molecular pathways remain unclear. We have shown previously that CYP2E1-mediated oxidative stress and circulating leptin in NAFLD is associated with renal disease severity. Extending the studies, we hypothesized that high circulatory leptin in NAFLD causes renal mesangial cell activation and tubular inflammation via a NOX2 dependent pathway that upregulates proinflammatory miR21. High-fat diet (60% kcal was used to induce fatty liver phenotype with parallel insulin and leptin resistance. The kidneys were probed for mesangial cell activation and tubular inflammation that showed accelerated NASH phenotype and oxidative stress in the liver. Results showed that NAFLD kidneys had significant increases in α-SMA, a marker of mesangial cell activation, miR21 levels, tyrosine nitration and renal inflammation while they were significantly decreased in leptin and p47 phox knockout mice. Micro RNA21 knockout mice showed decreased tubular immunotoxicity and proinflammatory mediator release. Mechanistically, use of NOX2 siRNA or apocynin,phenyl boronic acid (FBA, DMPO or miR21 antagomir inhibited leptin primed-miR21-mediated mesangial cell activation in vitro suggesting a direct role of leptin-mediated NOX-2 in miR21-mediated mesangial cell activation. Finally, JAK-STAT inhibitor completely abrogated the mesangial cell activation in leptin-primed cells suggesting that leptin signaling in the mesangial cells depended on the JAK-STAT pathway. Taken together the study reports a novel mechanistic pathway of leptin-mediated renal inflammation that is dependent on NOX-2-miR21 axis in ectopic manifestations underlying NAFLD-induced co-morbidities. Keywords: Leptin, NOX-2, NADPH, Mesangial cells, miR21, Oxidative stress, NAFLD, JAK/STAT, siRNA

  3. The transport of triglycerides through the secretory pathway of hepatocytes is impaired in apolipoprotein E deficient mice.

    NARCIS (Netherlands)

    Mensenkamp, A.R.; Luyn, M.J.A. van; Havinga, R.; Teusink, B.; Waterman, I.J.; Mann, C.J.; Elzinga, B.M.; Verkade, H.J.; Zammit, V.A.; Havekes, L.M.; Shoulders, C.C.; Kuipers, F.

    2004-01-01

    BACKGROUND/AIMS: Apolipoprotein E (apoE)-deficient mice develop hepatic steatosis and secrete reduced levels of VLDL-TG. METHODS AND RESULTS: We examined the effects of apoE-deficiency on intracellular lipid homeostasis and secretion of triglycerides (TG). We show that intracellular TG turnover and

  4. The transport of triglycerides through the secretory pathway of hepatocytes is impaired in apolipoprotein E deficient mice

    NARCIS (Netherlands)

    Mensenkamp, AR; van Luyn, MJA; Havinga, R; Teusink, B; Waterman, IJ; Mann, CJ; Elzinga, BM; Verkade, HJ; Zammit, VA; Havekes, LM; Shoulders, CC; Kuipers, F

    Background/Aims: Apolipoprotein E (apoE)-deficient mice develop hepatic steatosis and secrete reduced levels of VLDL-TG. Methods and results: We examined the effects of apoE-deficiency on intracellular lipid homeostasis and secretion of triglycerides (TG). We show that intracellular TG turnover and

  5. Improvement of cardiac contractile function by peptide-based inhibition of NF-κB in the utrophin/dystrophin-deficient murine model of muscular dystrophy

    Directory of Open Access Journals (Sweden)

    Guttridge Denis C

    2011-05-01

    Full Text Available Abstract Background Duchenne muscular dystrophy (DMD is an inherited and progressive disease causing striated muscle deterioration. Patients in their twenties generally die from either respiratory or cardiac failure. In order to improve the lifespan and quality of life of DMD patients, it is important to prevent or reverse the progressive loss of contractile function of the heart. Recent studies by our labs have shown that the peptide NBD (Nemo Binding Domain, targeted at blunting Nuclear Factor κB (NF-κB signaling, reduces inflammation, enhances myofiber regeneration, and improves contractile deficits in the diaphragm in dystrophin-deficient mdx mice. Methods To assess whether cardiac function in addition to diaphragm function can be improved, we investigated physiological and histological parameters of cardiac muscle in mice deficient for both dystrophin and its homolog utrophin (double knockout = dko mice treated with NBD peptide. These dko mice show classic pathophysiological hallmarks of heart failure, including myocyte degeneration, an impaired force-frequency response and a severely blunted β-adrenergic response. Cardiac contractile function at baseline and frequencies and pre-loads throughout the in vivo range as well as β-adrenergic reserve was measured in isolated cardiac muscle preparations. In addition, we studied histopathological and inflammatory markers in these mice. Results At baseline conditions, active force development in cardiac muscles from NBD treated dko mice was more than double that of vehicle-treated dko mice. NBD treatment also significantly improved frequency-dependent behavior of the muscles. The increase in force in NBD-treated dko muscles to β-adrenergic stimulation was robustly restored compared to vehicle-treated mice. However, histological features, including collagen content and inflammatory markers were not significantly different between NBD-treated and vehicle-treated dko mice. Conclusions We conclude

  6. Hypothalamic glycogen synthase kinase 3β has a central role in the regulation of food intake and glucose metabolism

    OpenAIRE

    Benzler, Jonas; Ganjam, Goutham K.; Krüger, Manon; Pinkenburg, Olaf; Kutschke, Maria; Stöhr, Sigrid; Steger, Juliane; Koch, Christiane E.; Ölkrug, Rebecca; Schwartz, Michael W.; Shepherd, Peter R.; Grattan, David R.; Tups, Alexander

    2012-01-01

    GSK3β (glycogen synthase kinase 3β) is a ubiquitous kinase that plays a key role in multiple intracellular signalling pathways, and increased GSK3β activity is implicated in disorders ranging from cancer to Alzheimer’s disease. In the present study, we provide the first evidence of increased hypothalamic signalling via GSK3β in leptin-deficient Lepob/ob mice and show that intracerebroventricular injection of a GSK3β inhibitor acutely improves glucose tolerance in these mice. The beneficial ef...

  7. Effects of Vector Backbone and Pseudotype on Lentiviral Vector-mediated Gene Transfer: Studies in Infant ADA-Deficient Mice and Rhesus Monkeys

    Science.gov (United States)

    Carbonaro Sarracino, Denise; Tarantal, Alice F; Lee, C Chang I.; Martinez, Michele; Jin, Xiangyang; Wang, Xiaoyan; Hardee, Cinnamon L; Geiger, Sabine; Kahl, Christoph A; Kohn, Donald B

    2014-01-01

    Systemic delivery of a lentiviral vector carrying a therapeutic gene represents a new treatment for monogenic disease. Previously, we have shown that transfer of the adenosine deaminase (ADA) cDNA in vivo rescues the lethal phenotype and reconstitutes immune function in ADA-deficient mice. In order to translate this approach to ADA-deficient severe combined immune deficiency patients, neonatal ADA-deficient mice and newborn rhesus monkeys were treated with species-matched and mismatched vectors and pseudotypes. We compared gene delivery by the HIV-1-based vector to murine γ-retroviral vectors pseudotyped with vesicular stomatitis virus-glycoprotein or murine retroviral envelopes in ADA-deficient mice. The vesicular stomatitis virus-glycoprotein pseudotyped lentiviral vectors had the highest titer and resulted in the highest vector copy number in multiple tissues, particularly liver and lung. In monkeys, HIV-1 or simian immunodeficiency virus vectors resulted in similar biodistribution in most tissues including bone marrow, spleen, liver, and lung. Simian immunodeficiency virus pseudotyped with the gibbon ape leukemia virus envelope produced 10- to 30-fold lower titers than the vesicular stomatitis virus-glycoprotein pseudotype, but had a similar tissue biodistribution and similar copy number in blood cells. The relative copy numbers achieved in mice and monkeys were similar when adjusted to the administered dose per kg. These results suggest that this approach can be scaled-up to clinical levels for treatment of ADA-deficient severe combined immune deficiency subjects with suboptimal hematopoietic stem cell transplantation options. PMID:24925206

  8. Effects of vector backbone and pseudotype on lentiviral vector-mediated gene transfer: studies in infant ADA-deficient mice and rhesus monkeys.

    Science.gov (United States)

    Carbonaro Sarracino, Denise; Tarantal, Alice F; Lee, C Chang I; Martinez, Michele; Jin, Xiangyang; Wang, Xiaoyan; Hardee, Cinnamon L; Geiger, Sabine; Kahl, Christoph A; Kohn, Donald B

    2014-10-01

    Systemic delivery of a lentiviral vector carrying a therapeutic gene represents a new treatment for monogenic disease. Previously, we have shown that transfer of the adenosine deaminase (ADA) cDNA in vivo rescues the lethal phenotype and reconstitutes immune function in ADA-deficient mice. In order to translate this approach to ADA-deficient severe combined immune deficiency patients, neonatal ADA-deficient mice and newborn rhesus monkeys were treated with species-matched and mismatched vectors and pseudotypes. We compared gene delivery by the HIV-1-based vector to murine γ-retroviral vectors pseudotyped with vesicular stomatitis virus-glycoprotein or murine retroviral envelopes in ADA-deficient mice. The vesicular stomatitis virus-glycoprotein pseudotyped lentiviral vectors had the highest titer and resulted in the highest vector copy number in multiple tissues, particularly liver and lung. In monkeys, HIV-1 or simian immunodeficiency virus vectors resulted in similar biodistribution in most tissues including bone marrow, spleen, liver, and lung. Simian immunodeficiency virus pseudotyped with the gibbon ape leukemia virus envelope produced 10- to 30-fold lower titers than the vesicular stomatitis virus-glycoprotein pseudotype, but had a similar tissue biodistribution and similar copy number in blood cells. The relative copy numbers achieved in mice and monkeys were similar when adjusted to the administered dose per kg. These results suggest that this approach can be scaled-up to clinical levels for treatment of ADA-deficient severe combined immune deficiency subjects with suboptimal hematopoietic stem cell transplantation options.

  9. Remodeling of Sensorimotor Brain Connectivity in Gpr88-Deficient Mice.

    Science.gov (United States)

    Arefin, Tanzil Mahmud; Mechling, Anna E; Meirsman, Aura Carole; Bienert, Thomas; Hübner, Neele Saskia; Lee, Hsu-Lei; Ben Hamida, Sami; Ehrlich, Aliza; Roquet, Dan; Hennig, Jürgen; von Elverfeldt, Dominik; Kieffer, Brigitte Lina; Harsan, Laura-Adela

    2017-10-01

    Recent studies have demonstrated that orchestrated gene activity and expression support synchronous activity of brain networks. However, there is a paucity of information on the consequences of single gene function on overall brain functional organization and connectivity and how this translates at the behavioral level. In this study, we combined mouse mutagenesis with functional and structural magnetic resonance imaging (MRI) to determine whether targeted inactivation of a single gene would modify whole-brain connectivity in live animals. The targeted gene encodes GPR88 (G protein-coupled receptor 88), an orphan G protein-coupled receptor enriched in the striatum and previously linked to behavioral traits relevant to neuropsychiatric disorders. Connectivity analysis of Gpr88-deficient mice revealed extensive remodeling of intracortical and cortico-subcortical networks. Most prominent modifications were observed at the level of retrosplenial cortex connectivity, central to the default mode network (DMN) whose alteration is considered a hallmark of many psychiatric conditions. Next, somatosensory and motor cortical networks were most affected. These modifications directly relate to sensorimotor gating deficiency reported in mutant animals and also likely underlie their hyperactivity phenotype. Finally, we identified alterations within hippocampal and dorsal striatum functional connectivity, most relevant to a specific learning deficit that we previously reported in Gpr88 -/- animals. In addition, amygdala connectivity with cortex and striatum was weakened, perhaps underlying the risk-taking behavior of these animals. This is the first evidence demonstrating that GPR88 activity shapes the mouse brain functional and structural connectome. The concordance between connectivity alterations and behavior deficits observed in Gpr88-deficient mice suggests a role for GPR88 in brain communication.

  10. LEPTIN RESISTANCE AND TYPE 2 DIABETES

    Directory of Open Access Journals (Sweden)

    O. M. Oleshchuk

    2017-07-01

    Full Text Available Leptin is one of adipocyte-secreted hormones. It signals to the brain and other tissues about the status of body energy reserves. Circulating leptin levels are directly proportional to the amount of the body fat. Leptin concentration increases when surfeit and decreases during fasting. Obese patients are hyperleptinemic compared with thin persons and they are tolerant to the central hypothalamic effects of leptin. The reduced sensitivity toward exogenous and endogenous leptin is commonly referred to as leptin resistance. Alterations in the signaling of the long isoform of the leptin receptor play the crucial role in leptin resistance. Surfeit may induce leptin resistance and other metabolic sequelae of obesity. Leptin insensitivity and insulin resistance play a major role in the development of type 2 diabetes. Metformin remains the preferred first-line pharmacologic agent for the treatment of type 2 diabetes. It reduces hepatic glucose production, increases glucose uptake in peripheral tissue and can lead to weight loss. Metformin decreases both insulin and leptin concentration, restores the sensitivity to these hormones. But some studies have shown poor relationship between metformin action and leptin level. And the mechanism of metformin action on leptin resistance remains unclear. Thus, these issues should be studied as well as polymorphisms in genes encoding metformin action.

  11. ZiBuPiYin recipe protects db/db mice from diabetes-associated cognitive decline through improving multiple pathological changes.

    Directory of Open Access Journals (Sweden)

    Jing Chen

    Full Text Available Multiple organ systems, including the brain, which undergoes changes that may increase the risk of cognitive decline, are adversely affected by diabetes mellitus (DM. Here, we demonstrate that type 2 diabetes mellitus (T2DM db/db mice exhibited hippocampus-dependent memory impairment, which might associate with a reduction in dendritic spine density in the pyramidal neurons of brain, Aβ1-42 deposition in the prefrontal cortex (PFC and hippocampus, and a decreased expression of neurostructural proteins including microtubule-associated protein (MAP2, a marker of dendrites, and postsynaptic density 95 (PSD95, a marker of excitatory synapses. To investigate the effects of the ZiBuPiYin recipe (ZBPYR, a traditional Chinese medicine recipe, on diabetes-related cognitive decline (DACD, db/db mice received daily administration of ZBPYR over an experimental period of 6 weeks. We then confirmed that ZBPYR rescued learning and memory performance impairments, reversed dendritic spine loss, reduced Aβ1-42 deposition and restored the expression levels of MAP2 and PSD95. The present study also revealed that ZBPYR strengthened brain leptin and insulin signaling and inhibited GSK3β overactivity, which may be the potential mechanism or underlying targets of ZBPYR. These findings conclude that ZBPYR prevents DACD, most likely by improving dendritic spine density and attenuating brain leptin and insulin signaling pathway injury. Our findings provide further evidence for the effects of ZBPYR on DACD.

  12. Truncated recombinant human SP-D attenuates emphysema and type II cell changes in SP-D deficient mice

    Directory of Open Access Journals (Sweden)

    Mühlfeld Christian

    2007-10-01

    Full Text Available Abstract Background Surfactant protein D (SP-D deficient mice develop emphysema-like pathology associated with focal accumulations of foamy alveolar macrophages, an excess of surfactant phospholipids in the alveolar space and both hypertrophy and hyperplasia of alveolar type II cells. These findings are associated with a chronic inflammatory state. Treatment of SP-D deficient mice with a truncated recombinant fragment of human SP-D (rfhSP-D has been shown to decrease the lipidosis and alveolar macrophage accumulation as well as production of proinflammatory chemokines. The aim of this study was to investigate if rfhSP-D treatment reduces the structural abnormalities in parenchymal architecture and type II cells characteristic of SP-D deficiency. Methods SP-D knock-out mice, aged 3 weeks, 6 weeks and 9 weeks were treated with rfhSP-D for 9, 6 and 3 weeks, respectively. All mice were sacrificed at age 12 weeks and compared to both PBS treated SP-D deficient and wild-type groups. Lung structure was quantified by design-based stereology at the light and electron microscopic level. Emphasis was put on quantification of emphysema, type II cell changes and intracellular surfactant. Data were analysed with two sided non-parametric Mann-Whitney U-test. Main Results After 3 weeks of treatment, alveolar number was higher and mean alveolar size was smaller compared to saline-treated SP-D knock-out controls. There was no significant difference concerning these indices of pulmonary emphysema within rfhSP-D treated groups. Type II cell number and size were smaller as a consequence of treatment. The total volume of lamellar bodies per type II cell and per lung was smaller after 6 weeks of treatment. Conclusion Treatment of SP-D deficient mice with rfhSP-D leads to a reduction in the degree of emphysema and a correction of type II cell hyperplasia and hypertrophy. This supports the concept that rfhSP-D might become a therapeutic option in diseases that are

  13. Early-Life Persistent Vitamin D Deficiency Alters Cardiopulmonary Responses to Particulate Matter-Enhanced Atmospheric Smog in Adult Mice

    Science.gov (United States)

    This study demonstrates that early-life persistent vitamin D deficiency alters the cardiopulmonary response to smog in mice and may increase risk of adverse effects. Early life nutritional deficiencies can lead to increased cardiovascular susceptibility to environme...

  14. Amplification of EDHF-type vasodilatations in TRPC1-deficient mice

    DEFF Research Database (Denmark)

    Schmidt, Kjestine; Dubrovska, Galyna; Nielsen, Gorm

    2010-01-01

    -deficient mice (TRPC1-/-). Experimental approach. Vascular responses were studied using pressure/wire-myography and intravital microscopy. We performed electrophysiological measurements, and confocal Ca(2+) imaging for studying K(Ca)-channel functions and Ca(2+)sparks. Key results. TRPC1-deficiency...... in carotid arteries produced a twofold augmentation of TRAM-34- and UCL1684-sensitive EDHF-type vasodilatations and of endothelial hyperpolarization to acetylcholine. NO-mediated vasodilatations were unchanged. TRPC1-/- exhibited enhanced EDHF-type vasodilatations in resistance-sized arterioles in vivo...... associated with reduced spontaneous tone. Endothelial IK(Ca)/SK(Ca)-type K(Ca) currents, smooth muscle cell Ca(2+) sparks and associated BK(Ca)-mediated spontaneous transient outward currents (STOC) were unchanged in TRPC1-/-. Smooth muscle contractility induced by receptor-operated Ca(2+) influx or Ca(2...

  15. Kaempferol regulates OPN–CD44 pathway to inhibit the atherogenesis of apolipoprotein E deficient mice

    International Nuclear Information System (INIS)

    Xiao, Hong-Bo; Lu, Xiang-Yang; Sun, Zhi-Liang; Zhang, Heng-Bo

    2011-01-01

    Recent studies show that osteopontin (OPN) and its receptor cluster of differentiation 44 (CD44) are two pro-inflammatory cytokines contributing to the development of atherosclerosis. The objective of this study was to explore the inhibitory effect of kaempferol, a naturally occurring flavonoid compound, on atherogenesis and the mechanisms involved. The experiments were performed in aorta and plasma from C57BL/6J control and apolipoprotein E-deficient (ApoE −/− ) mice treated or not with kaempferol (50 or 100 mg/kg, intragastrically) for 4 weeks. Kaempferol treatment decreased atherosclerotic lesion area, improved endothelium-dependent vasorelaxation, and increased the maximal relaxation value concomitantly with decrease in the half-maximum effective concentration, plasma OPN level, aortic OPN expression, and aortic CD44 expression in ApoE −/− mice. In addition, treatment with kaempferol also significantly decreased reactive oxygen species production in mice aorta. The present results suggest that kaempferol regulates OPN–CD44 pathway to inhibit the atherogenesis of ApoE −/− mice. -- Graphical abstract: Kaempferol regulates OPN–CD44 pathway to inhibit the atherogenesis of ApoE −/− mice. Highlights: ► OPN–CD44 pathway plays a critical role in the development of atherosclerosis. ► We examine lesion area, OPN and CD44 changes after kaempferol treatment. ► Kaempferol treatment decreased atherosclerotic lesion area in ApoE −/− mice. ► Kaempferol treatment decreased aortic OPN and CD44 expressions in ApoE −/− mice. ► Kaempferol regulates OPN–CD44 pathway to inhibit the atherogenesis.

  16. Kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis of apolipoprotein E deficient mice

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Hong-Bo, E-mail: xhbzhb@yahoo.com [College of Veterinary Medicine, Hunan Agricultural University, Changsha 410128 (China); Lu, Xiang-Yang; Sun, Zhi-Liang [Hunan Agricultural University, Changsha 410128 (China); Zhang, Heng-Bo [Furong District Red Cross Hospital, Changsha 410126 (China)

    2011-12-15

    Recent studies show that osteopontin (OPN) and its receptor cluster of differentiation 44 (CD44) are two pro-inflammatory cytokines contributing to the development of atherosclerosis. The objective of this study was to explore the inhibitory effect of kaempferol, a naturally occurring flavonoid compound, on atherogenesis and the mechanisms involved. The experiments were performed in aorta and plasma from C57BL/6J control and apolipoprotein E-deficient (ApoE{sup -/-}) mice treated or not with kaempferol (50 or 100 mg/kg, intragastrically) for 4 weeks. Kaempferol treatment decreased atherosclerotic lesion area, improved endothelium-dependent vasorelaxation, and increased the maximal relaxation value concomitantly with decrease in the half-maximum effective concentration, plasma OPN level, aortic OPN expression, and aortic CD44 expression in ApoE{sup -/-} mice. In addition, treatment with kaempferol also significantly decreased reactive oxygen species production in mice aorta. The present results suggest that kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis of ApoE{sup -/-} mice. -- Graphical abstract: Kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis of ApoE{sup -/-} mice. Highlights: Black-Right-Pointing-Pointer OPN-CD44 pathway plays a critical role in the development of atherosclerosis. Black-Right-Pointing-Pointer We examine lesion area, OPN and CD44 changes after kaempferol treatment. Black-Right-Pointing-Pointer Kaempferol treatment decreased atherosclerotic lesion area in ApoE{sup -/-} mice. Black-Right-Pointing-Pointer Kaempferol treatment decreased aortic OPN and CD44 expressions in ApoE{sup -/-} mice. Black-Right-Pointing-Pointer Kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis.

  17. Genetic variation in the leptin receptor gene, leptin, and weight gain in young Dutch adults.

    Science.gov (United States)

    van Rossum, Caroline T M; Hoebee, Barbara; van Baak, Marleen A; Mars, Monica; Saris, Wim H M; Seidell, Jacob C

    2003-03-01

    To investigate the association between leptin levels, polymorphisms in the leptin receptor (LEPR) gene, and weight gain. From two large prospective cohorts in The Netherlands (n = 17,500), we compared the baseline leptin of 259 subjects who had gained an average of 12.6 kg (range 5.5 to 33 kg) with 277 subjects who kept stable weight (range -2.6 to 3.1 kg) after a mean follow-up of 6.8 years. Three polymorphisms in the LEPR gene (Lys109Arg, Gln223Arg, and Lys656Asn) were determined. Weight gainers had significantly higher baseline leptin levels than those who kept stable weight (odds ratio = 1.27, 95% confidence interval 1.1 to 1.5, per SD increase in log(e)-transformed leptin). Weight gainers with the Arg109 or the Arg223 alleles had higher leptin levels compared with the noncarriers of these alleles. Only among men, the association between leptin and weight gain tended to be stronger among those with an Arg223 allele compared with those without this mutation. Relatively high leptin levels predict weight gain, suggesting that leptin resistance plays a role in the development of obesity in the general population. Higher leptin levels for those with a Lys109Arg or Gln223Arg mutation (or a linked other marker) may imply that these subjects have a modified functional leptin receptor. However, the role of these mutations on weight gain is limited.

  18. Hepatic tissue environment in NEMO-deficient mice critically regulates positive selection of donor cells after hepatocyte transplantation.

    Directory of Open Access Journals (Sweden)

    Michaela Kaldenbach

    Full Text Available BACKGROUND: Hepatocyte transplantation (HT is a promising alternative treatment strategy for end-stage liver diseases compared with orthotopic liver transplantation. A limitation for this approach is the low engraftment of donor cells. The deletion of the I-kappa B kinase-regulatory subunit IKKγ/NEMO in hepatocytes prevents nuclear factor (NF-kB activation and triggers spontaneous liver apoptosis, chronic hepatitis and the development of liver fibrosis and hepatocellular carcinoma. We hypothesized that NEMOΔhepa mice may therefore serve as an experimental model to study HT. METHODS: Pre-conditioned NEMOΔhepa mice were transplanted with donor-hepatocytes from wildtype (WT and mice deficient for the pro-apoptotic mediator Caspase-8 (Casp8Δhepa. RESULTS: Transplantation of isolated WT-hepatocytes into pre-conditioned NEMOΔhepa mice resulted in a 6-7 fold increase of donor cells 12 weeks after HT, while WT-recipients showed no liver repopulation. The use of apoptosis-resistant Casp8Δhepa-derived donor cells further enhanced the selection 3-fold after 12-weeks and up to 10-fold increase after 52 weeks compared with WT donors. While analysis of NEMOΔhepa mice revealed strong liver injury, HT-recipient NEMOΔhepa mice showed improved liver morphology and decrease in serum transaminases. Concomitant with these findings, the histological examination elicited an improved liver tissue architecture associated with significantly lower levels of apoptosis, decreased proliferation and a lesser amount of liver fibrogenesis. Altogether, our data clearly support the therapeutic benefit of the HT procedure into NEMOΔhepa mice. CONCLUSION: This study demonstrates the feasibility of the NEMOΔhepa mouse as an in vivo tool to study liver repopulation after HT. The improvement of the characteristic phenotype of chronic liver injury in NEMOΔhepa mice after HT suggests the therapeutic potential of HT in liver diseases with a chronic inflammatory phenotype and

  19. Leptin Regulation of Gonadotrope Gonadotropin-Releasing Hormone Receptors As a Metabolic Checkpoint and Gateway to Reproductive Competence

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    Angela K. Odle

    2018-01-01

    Full Text Available The adipokine leptin signals the body’s nutritional status to the brain, and particularly, the hypothalamus. However, leptin receptors (LEPRs can be found all throughout the body and brain, including the pituitary. It is known that leptin is permissive for reproduction, and mice that cannot produce leptin (Lep/Lep are infertile. Many studies have pinpointed leptin’s regulation of reproduction to the hypothalamus. However, LEPRs exist at all levels of the hypothalamic–pituitary–gonadal axis. We have previously shown that deleting the signaling portion of the LEPR specifically in gonadotropes impairs fertility in female mice. Our recent studies have targeted this regulation to the control of gonadotropin releasing hormone receptor (GnRHR expression. The hypotheses presented here are twofold: (1 cyclic regulation of pituitary GnRHR levels sets up a target metabolic checkpoint for control of the reproductive axis and (2 multiple checkpoints are required for the metabolic signaling that regulates the reproductive axis. Here, we emphasize and explore the relationship between the hypothalamus and the pituitary with regard to the regulation of GnRHR. The original data we present strengthen these hypotheses and build on our previous studies. We show that we can cause infertility in 70% of female mice by deleting all isoforms of LEPR specifically in gonadotropes. Our findings implicate activin subunit (InhBa mRNA as a potential leptin target in gonadotropes. We further show gonadotrope-specific upregulation of GnRHR protein (but not mRNA levels following leptin stimulation. In order to try and understand this post-transcriptional regulation, we tested candidate miRNAs (identified with in silico analysis that may be binding the Gnrhr mRNA. We show significant upregulation of one of these miRNAs in our gonadotrope-Lepr-null females. The evidence provided here, combined with our previous work, lay the foundation for metabolically regulated post

  20. Fetal skeletal muscle progenitors have regenerative capacity after intramuscular engraftment in dystrophin deficient mice.

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    Hiroshi Sakai

    Full Text Available Muscle satellite cells (SCs are stem cells that reside in skeletal muscles and contribute to regeneration upon muscle injury. SCs arise from skeletal muscle progenitors expressing transcription factors Pax3 and/or Pax7 during embryogenesis in mice. However, it is unclear whether these fetal progenitors possess regenerative ability when transplanted in adult muscle. Here we address this question by investigating whether fetal skeletal muscle progenitors (FMPs isolated from Pax3(GFP/+ embryos have the capacity to regenerate muscle after engraftment into Dystrophin-deficient mice, a model of Duchenne muscular dystrophy. The capacity of FMPs to engraft and enter the myogenic program in regenerating muscle was compared with that of SCs derived from adult Pax3(GFP/+ mice. Transplanted FMPs contributed to the reconstitution of damaged myofibers in Dystrophin-deficient mice. However, despite FMPs and SCs having similar myogenic ability in culture, the regenerative ability of FMPs was less than that of SCs in vivo. FMPs that had activated MyoD engrafted more efficiently to regenerate myofibers than MyoD-negative FMPs. Transcriptome and surface marker analyses of these cells suggest the importance of myogenic priming for the efficient myogenic engraftment. Our findings suggest the regenerative capability of FMPs in the context of muscle repair and cell therapy for degenerative muscle disease.

  1. Experimental approach to IGF-1 therapy in CCl4-induced acute liver damage in healthy controls and mice with partial IGF-1 deficiency.

    Science.gov (United States)

    Morales-Garza, Luis A; Puche, Juan E; Aguirre, Gabriel A; Muñoz, Úrsula; García-Magariño, Mariano; De la Garza, Rocío G; Castilla-Cortazar, Inma

    2017-05-04

    Cell necrosis, oxidative damage, and fibrogenesis are involved in cirrhosis development, a condition in which insulin-like growth factor 1 (IGF-1) levels are diminished. This study evaluates whether the exogenous administration of low doses of IGF-1 can induce hepatoprotection in acute carbon tetrachloride (CCl 4 )-induced liver damage compared to healthy controls (Wt Igf +/+ ). Additionally, the impact of IGF-1 deficiency on a damaged liver was investigated in mice with a partial deficit of this hormone (Hz Igf1 +/- ). Three groups of 25 ± 5-week-old healthy male mice (Wt Igf +/+ ) were included in the protocol: untreated controls (Wt). Controls that received CCl 4 (Wt + CCl 4 ) and Wt + CCl 4 were treated subcutaneously with IGF-1 (2 µg/100 g body weight/day) for 10 days (Wt + CCl 4  + IGF1). In parallel, three IGF-1-deficient mice (Hz Igf1 +/- ) groups were studied: untreated Hz, Hz + CCl 4 , and Hz + CCl 4  + IGF-1. Microarray and real-time quantitative polymerase chain reaction (RT-qPCR) analyses, serum aminotransferases levels, liver histology, and malondialdehyde (MDA) levels were assessed at the end of the treatment in all groups. All data represent mean ± SEM. An altered gene coding expression pattern for proteins of the extracellular matrix, fibrosis, and cellular protection were found, as compared to healthy controls, in which IGF-1 therapy normalized in the series including healthy mice. Liver histology showed that Wt + CCl 4  + IGF1 mice had less oxidative damage, fibrosis, lymphocytic infiltrate, and cellular changes when compared to the Wt + CCl 4 . Moreover, there was a correlation between MDA levels and the histological damage score (Pearson's r = 0.858). In the IGF-1-deficient mice series, similar findings were identified, denoting a much more vulnerable hepatic parenchyma. IGF1 treatment improved the biochemistry, histology, and genetic expression of pro-regenerative and cytoprotective factors in both series

  2. Firing properties of dopamine neurons in freely moving dopamine-deficient mice: Effects of dopamine receptor activation and anesthesia

    OpenAIRE

    Robinson, Siobhan; Smith, David M.; Mizumori, Sheri J. Y.; Palmiter, Richard D.

    2004-01-01

    To examine the regulation of midbrain dopamine neurons, recordings were obtained from single neurons of freely moving, genetically engineered dopamine-deficient (DD) mice. DD mice were tested without dopamine signaling (basal state) and with endogenous dopamine signaling (after L-dopa administration). In the basal state, when dopamine concentration in DD mice is

  3. Effect of zinc supplementation on body mass index and serum levels of zinc and leptin in pediatric hemodialysis patients

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    El-Shazly AN

    2015-12-01

    Full Text Available Ahmed Nabih El-Shazly,1 Soha Abd El-Hady Ibrahim,1 Ghada Mohamed El-Mashad,2 Jehan H Sabry,3 Nashwa Said Sherbini11Department of Pediatrics, Faculty of Medicine, Benha University, Banha, 2Department of Pediatrics, Faculty of Medicine, Menoufia University, Shibin Al Kawm, 3Department of Clinical and Chemical Pathology, Faculty of Medicine, Benha University, Banha, Egypt Introduction: Zinc is an essential trace element for human nutrition, and its deficiency is associated with anorexia, poor food efficiency, growth retardation, and impaired neurological and immune systems. The zinc-deficiency rate is particularly high in many disease states, such as with end-stage renal disease patients undertaking hemodialysis. The aim of this study was to determine the effect of zinc supplementation on body mass index (BMI and serum levels of zinc and leptin in pediatric hemodialysis patients. Patients and methods: This was a prospective clinical trial study in which 60 hemodialysis patients were randomly divided into two groups: group I received 50–100 mg zinc sulfate (equivalent to 11–22 mg elemental zinc according to age, sex, and nutritional status of the child; and group II received placebo (cornstarch twice daily for 90 days. Anthropometric measurements were taken, and serum zinc and leptin levels were determined by colorimetric test with 5-Br-3'-phosphoadenosine-5'-phosphosulfate and enzyme-linked immunosorbent assay, respectively, at days 0 and 90 of the study. Results: Zinc supplementation resulted in a significant increase in mean serum zinc level and BMI. Serum leptin decreased significantly after supplementation in children under hemodialysis. A significant negative correlation was observed between serum zinc and leptin levels as a result of zinc supplementation. Conclusion: There was an increase in serum zinc level and BMI and decreased serum leptin after zinc supplementation in children under hemodialysis. Keywords: serum zinc, serum leptin

  4. Selenoprotein-deficient transgenic mice exhibit enhanced exercise-induced muscle growth.

    Science.gov (United States)

    Hornberger, Troy A; McLoughlin, Thomas J; Leszczynski, Jori K; Armstrong, Dustin D; Jameson, Ruth R; Bowen, Phyllis E; Hwang, Eun-Sun; Hou, Honglin; Moustafa, Mohamed E; Carlson, Bradley A; Hatfield, Dolph L; Diamond, Alan M; Esser, Karyn A

    2003-10-01

    Dietary intake of selenium has been implicated in a wide range of health issues, including aging, heart disease and cancer. Selenium deficiency, which can reduce selenoprotein levels, has been associated with several striated muscle pathologies. To investigate the role of selenoproteins in skeletal muscle biology, we used a transgenic mouse (referred to as i6A-) that has reduced levels of selenoproteins due to the introduction and expression of a dominantly acting mutant form of selenocysteine transfer RNA (tRNA[Ser]Sec). As a consequence, each organ contains reduced levels of most selenoproteins, yet these mice are normal with regard to fertility, overall health, behavior and blood chemistries. In the present study, although skeletal muscles from i6A- mice were phenotypically indistinguishable from those of wild-type mice, plantaris muscles were approximately 50% heavier after synergist ablation, a model of exercise overload. Like muscle in wild-type mice, the enhanced growth in the i6A- mice was completely blocked by inhibition of the mammalian target of rapamycin (mTOR) pathway. Muscles of transgenic mice exhibited increased site-specific phosphorylation on both Akt and p70 ribosomal S6 kinase (p70S6k) (P accounting for the enhanced response to synergist ablation. Thus, a single genetic alteration resulted in enhanced skeletal muscle adaptation after exercise, and this is likely through subtle changes in the resting phosphorylation state of growth-related kinases.

  5. PNPLA1 Deficiency in Mice and Humans Leads to a Defect in the Synthesis of Omega-O-Acylceramides

    Science.gov (United States)

    Grond, Susanne; Eichmann, Thomas O.; Dubrac, Sandrine; Kolb, Dagmar; Schmuth, Matthias; Fischer, Judith; Crumrine, Debra; Elias, Peter M.; Haemmerle, Guenter; Zechner, Rudolf; Lass, Achim; Radner, Franz P.W.

    2017-01-01

    Mutations in PNPLA1 have been identified as causative for autosomal recessive congenital ichthyosis in humans and dogs. So far, the underlying molecular mechanisms are unknown. In this study, we generated and characterized PNPLA1-deficient mice and found that PNPLA1 is crucial for epidermal sphingolipid synthesis. The absence of functional PNPLA1 in mice impaired the formation of omega-O-acylceramides and led to an accumulation of nonesterified omega-hydroxy-ceramides. As a consequence, PNPLA1-deficient mice lacked a functional corneocyte-bound lipid envelope leading to a severe skin barrier defect and premature death of newborn animals. Functional analyses of differentiated keratinocytes from a patient with mutated PNPLA1 demonstrated an identical defect in omega-O-acylceramide synthesis in human cells, indicating that PNPLA1 function is conserved among mammals and indispensable for normal skin physiology. Notably, topical application of epidermal lipids from wild-type onto Pnpla1-mutant mice promoted rebuilding of the corneocyte-bound lipid envelope, indicating that supplementation of ichthyotic skin with omega-O-acylceramides might be a therapeutic approach for the treatment of skin symptoms in individuals affected by omega-O-acylceramide deficiency. PMID:27751867

  6. Abnormal brain iron metabolism in Irp2 deficient mice is associated with mild neurological and behavioral impairments.

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    Kimberly B Zumbrennen-Bullough

    Full Text Available Iron Regulatory Protein 2 (Irp2, Ireb2 is a central regulator of cellular iron homeostasis in vertebrates. Two global knockout mouse models have been generated to explore the role of Irp2 in regulating iron metabolism. While both mouse models show that loss of Irp2 results in microcytic anemia and altered body iron distribution, discrepant results have drawn into question the role of Irp2 in regulating brain iron metabolism. One model shows that aged Irp2 deficient mice develop adult-onset progressive neurodegeneration that is associated with axonal degeneration and loss of Purkinje cells in the central nervous system. These mice show iron deposition in white matter tracts and oligodendrocyte soma throughout the brain. A contrasting model of global Irp2 deficiency shows no overt or pathological signs of neurodegeneration or brain iron accumulation, and display only mild motor coordination and balance deficits when challenged by specific tests. Explanations for conflicting findings in the severity of the clinical phenotype, brain iron accumulation and neuronal degeneration remain unclear. Here, we describe an additional mouse model of global Irp2 deficiency. Our aged Irp2-/- mice show marked iron deposition in white matter and in oligodendrocytes while iron content is significantly reduced in neurons. Ferritin and transferrin receptor 1 (TfR1, Tfrc, expression are increased and decreased, respectively, in the brain from Irp2-/- mice. These mice show impairments in locomotion, exploration, motor coordination/balance and nociception when assessed by neurological and behavioral tests, but lack overt signs of neurodegenerative disease. Ultrastructural studies of specific brain regions show no evidence of neurodegeneration. Our data suggest that Irp2 deficiency dysregulates brain iron metabolism causing cellular dysfunction that ultimately leads to mild neurological, behavioral and nociceptive impairments.

  7. Opposing effects of CXCR3 and CCR5 deficiency on CD8+ T cell-mediated inflammation in the central nervous system of virus-infected mice

    DEFF Research Database (Denmark)

    de Lemos, Carina; Christensen, Jeanette Erbo; Nansen, Anneline

    2005-01-01

    and therefore protect mice against the otherwise fatal CD8+ T cell-mediated immune attack. Contrary to expectations, the accumulation of mononuclear cells in cerebrospinal fluid was only slightly delayed compared with mice with normal expression of both receptors. Even more surprising, CXCR3/CCR5 double-deficient......T cells play a key role in the control of viral infection in the CNS but may also contribute to immune-mediated cell damage. To study the redundancy of the chemokine receptors CXCR3 and CCR5 in regulating virus-induced CD8+ T cell-mediated inflammation in the brain, CXCR3/CCR5 double-deficient mice...... mice were more susceptible to intracerebral infection than CXCR3-deficient mice. Analysis of effector T cell generation revealed an accelerated antiviral CD8+ T cell response in CXCR3/CCR5 double-deficient mice. Furthermore, while the accumulation of CD8+ T cells in the neural parenchyma...

  8. The role of interleukin-5 (IL-5 in vivo: studies with IL-5 deficient mice

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    Klaus I Matthaei

    1997-12-01

    Full Text Available Eosinophil recruitment is a characteristic feature of a number of pathological conditions and was the topic of the recent International Symposium on allergic inflammation, asthma, parasitic and infectious diseases (Rio de Janeiro, June 3-5, 1996. Since interleukin5 (IL5 is believed to regulate the growth, differentiation and activation of eosinophils (Coffman et al. 1989, Sanderson 1992, the role of eosinophils and IL5 are closely linked. Although IL5 specifically regulates eosinophilia in vivo and this is its most well established activity, it is becoming clear that IL5 also has other biological effects. The recent derivation of an IL5 deficient mouse (Kopf et al. 1996, provides a model for exploring not only the role of IL5 and eosinophils but also other novel activities of IL5. Of note is that although the IL5 deficient mice cannot elicit a pronounced eosinophilia in response to inflammatory stimulation following aeroallergen challenge or parasite infection they still produce basal levels of eosinophils that appear to be morphologically and functionally normal. However, the basal levels of eosinophils appear insufficient for normal host defence as IL5 deficiency has now been shown to compromise defence against several helminth infections. In addition, IL5 deficient mice appear to have functional deficiencies in B-1 B lymphocytes and in IgA production.

  9. Chronic mild stress impairs latent inhibition and induces region-specific neural activation in CHL1-deficient mice, a mouse model of schizophrenia.

    Science.gov (United States)

    Buhusi, Mona; Obray, Daniel; Guercio, Bret; Bartlett, Mitchell J; Buhusi, Catalin V

    2017-08-30

    Schizophrenia is a neurodevelopmental disorder characterized by abnormal processing of information and attentional deficits. Schizophrenia has a high genetic component but is precipitated by environmental factors, as proposed by the 'two-hit' theory of schizophrenia. Here we compared latent inhibition as a measure of learning and attention, in CHL1-deficient mice, an animal model of schizophrenia, and their wild-type littermates, under no-stress and chronic mild stress conditions. All unstressed mice as well as the stressed wild-type mice showed latent inhibition. In contrast, CHL1-deficient mice did not show latent inhibition after exposure to chronic stress. Differences in neuronal activation (c-Fos-positive cell counts) were noted in brain regions associated with latent inhibition: Neuronal activation in the prelimbic/infralimbic cortices and the nucleus accumbens shell was affected solely by stress. Neuronal activation in basolateral amygdala and ventral hippocampus was affected independently by stress and genotype. Most importantly, neural activation in nucleus accumbens core was affected by the interaction between stress and genotype. These results provide strong support for a 'two-hit' (genes x environment) effect on latent inhibition in CHL1-deficient mice, and identify CHL1-deficient mice as a model of schizophrenia-like learning and attention impairments. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Hematopoietic sphingosine 1-phosphate lyase deficiency decreases atherosclerotic lesion development in LDL-receptor deficient mice.

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    Martine Bot

    Full Text Available AIMS: Altered sphingosine 1-phosphate (S1P homeostasis and signaling is implicated in various inflammatory diseases including atherosclerosis. As S1P levels are tightly controlled by S1P lyase, we investigated the impact of hematopoietic S1P lyase (Sgpl1(-/- deficiency on leukocyte subsets relevant to atherosclerosis. METHODS AND RESULTS: LDL receptor deficient mice that were transplanted with Sgpl1(-/- bone marrow showed disrupted S1P gradients translating into lymphopenia and abrogated lymphocyte mitogenic and cytokine response as compared to controls. Remarkably however, Sgpl1(-/- chimeras displayed mild monocytosis, due to impeded stromal retention and myelopoiesis, and plasma cytokine and macrophage expression patterns, that were largely compatible with classical macrophage activation. Collectively these two phenotypic features of Sgpl1 deficiency culminated in diminished atherogenic response. CONCLUSIONS: Here we not only firmly establish the critical role of hematopoietic S1P lyase in controlling S1P levels and T cell trafficking in blood and lymphoid tissue, but also identify leukocyte Sgpl1 as critical factor in monocyte macrophage differentiation and function. Its, partly counterbalancing, pro- and anti-inflammatory activity spectrum imply that intervention in S1P lyase function in inflammatory disorders such as atherosclerosis should be considered with caution.

  11. Sheep oocyte expresses leptin and functional leptin receptor mRNA

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    Seyyed Jalil Taheri

    2016-09-01

    Conclusions: The result of present study reveals that leptin and its functional receptor (Ob-Rb mRNA are expressed in sheep oocyte and further studies should investigate the role(s of leptin on sheep oocyte physiology and embryo development.

  12. Characterization of Leptin Intracellular Trafficking

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    E Walum

    2009-12-01

    Full Text Available Leptin is produced by adipose tissue, and its concentration in plasma is related to the amount of fat in the body. The leptin receptor (OBR is a member of the class I cytokine receptor family and several different isoforms, produced by alternative mRNA splicing are found in many tissues, including the hypothalamus. The two predominant isoforms includes a long form (OBRl with an intracellular domain of 303 amino acids and a shorter form (OBRs with an intracellular domain of 34 amino acids. Since OBRl is mainly expressed in the hypotalamus, it has been suggested to be the main signalling form. The peripheral production of leptin by adipocyte tissue and its effects as a signal of satiety in the central nervous system imply that leptin gains access to regions of the brain regulating in energy balance by crossing the blood-brain barrier. In an attempt to characterize the intracellular transport of leptin, we have followed binding internalization and degradation of leptin in HEK293 cells. We have also monitored the intracellular transport pathway of fluorescent conjugated leptin in HEK293 cells. Phenylarsine oxide, a general inhibitor of endocytosis, as well as incubation at mild hypertonic conditions, prevented the uptake of leptin, confirming a receptor-mediated internalization process. When internalized, 125I-leptin was rapidly accumulated inside the cells and reached a maximum after 10 min. After 70 minutes about 40-50% of total counts in each time point were found in the medium as TCA-soluble material. Leptin sorting, at the level of early endosomes, did not seem to involve recycling endosomes, since FITC-leptin was sorted from Cy3- transferrin containing compartments at 37°C. At 45 minutes of continuos internalization, FITC-leptin appeared mainly accumulated in late endocytic structures colocalizing with internalized rhodamine coupled epidermial growth factor (EGF and the lysosomal marker protein lamp-1. The transport of leptin was also shown

  13. Elevated circulating leptin levels in arterial hypertension: relationship to arteriovenous overflow and extraction of leptin

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik Sahl; Holst, J J; Moller, S

    2000-01-01

    Leptin, a peptide hormone produced mainly in fat cells, appears to be important for the regulation of metabolism, insulin secretion/sensitivity and body weight. Recently, elevated plasma leptin levels have been reported in patients with arterial hypertension. Because a change in circulating leptin...... concentrations in such patients could be caused by altered rates of production or disposal, or both, the aim of the present study was to identify regions of leptin overflow into the bloodstream and of leptin extraction. Patients with arterial hypertension (n=12) and normotensive controls (n=20) were studied...... during catheterization with elective blood sampling from different vascular beds (artery, and renal, hepatic, iliac and cubital veins). Plasma leptin was determined by a radioimmunoassay. Patients with hypertension had significantly elevated levels of circulating leptin (12.8 ng/l, compared with 4.1 ng...

  14. Metabolomics Approach Reveals Integrated Metabolic Network Associated with Serotonin Deficiency

    Science.gov (United States)

    Weng, Rui; Shen, Sensen; Tian, Yonglu; Burton, Casey; Xu, Xinyuan; Liu, Yi; Chang, Cuilan; Bai, Yu; Liu, Huwei

    2015-07-01

    Serotonin is an important neurotransmitter that broadly participates in various biological processes. While serotonin deficiency has been associated with multiple pathological conditions such as depression, schizophrenia, Alzheimer’s disease and Parkinson’s disease, the serotonin-dependent mechanisms remain poorly understood. This study therefore aimed to identify novel biomarkers and metabolic pathways perturbed by serotonin deficiency using metabolomics approach in order to gain new metabolic insights into the serotonin deficiency-related molecular mechanisms. Serotonin deficiency was achieved through pharmacological inhibition of tryptophan hydroxylase (Tph) using p-chlorophenylalanine (pCPA) or genetic knockout of the neuronal specific Tph2 isoform. This dual approach improved specificity for the serotonin deficiency-associated biomarkers while minimizing nonspecific effects of pCPA treatment or Tph2 knockout (Tph2-/-). Non-targeted metabolic profiling and a targeted pCPA dose-response study identified 21 biomarkers in the pCPA-treated mice while 17 metabolites in the Tph2-/- mice were found to be significantly altered compared with the control mice. These newly identified biomarkers were associated with amino acid, energy, purine, lipid and gut microflora metabolisms. Oxidative stress was also found to be significantly increased in the serotonin deficient mice. These new biomarkers and the overall metabolic pathways may provide new understanding for the serotonin deficiency-associated mechanisms under multiple pathological states.

  15. Leptin acts on neoplastic behavior and expression levels of genes related to hypoxia, angiogenesis, and invasiveness in oral squamous cell carcinoma.

    Science.gov (United States)

    Sobrinho Santos, Eliane Macedo; Guimarães, Talita Antunes; Santos, Hércules Otacílio; Cangussu, Lilian Mendes Borborema; de Jesus, Sabrina Ferreira; Fraga, Carlos Alberto de Carvalho; Cardoso, Claudio Marcelo; Santos, Sérgio Henrique Souza; de Paula, Alfredo Maurício Batista; Gomez, Ricardo Santiago; Guimarães, André Luiz Sena; Farias, Lucyana Conceição

    2017-05-01

    Leptin, one of the main hormones controlling energy homeostasis, has been associated with different cancer types. In oral cancer, its effect is not well understood. We investigated, through in vitro and in vivo assays, whether leptin can affect the neoplastic behavior of oral squamous cell carcinoma. Expression of genes possibly linked to the leptin pathway was assessed in leptin-treated oral squamous cell carcinoma cells and also in tissue samples of oral squamous cell carcinoma and oral mucosa, including leptin, leptin receptor, hypoxia-inducible factor 1-alpha, E-cadherin, matrix metalloproteinase-2, matrix metalloproteinase-9, Col1A1, Ki67, and mir-210. Leptin treatment favored higher rates of cell proliferation and migration, and reduced apoptosis. Accordingly, leptin-treated oral squamous cell carcinoma cells show decreased messenger RNA caspase-3 expression, and increased levels of E-cadherin, Col1A1, matrix metalloproteinase-2, matrix metalloproteinase-9, and mir-210. In tissue samples, hypoxia-inducible factor 1-alpha messenger RNA and protein expression of leptin and leptin receptor were high in oral squamous cell carcinoma cases. Serum leptin levels were increased in first clinical stages of the disease. In animal model, oral squamous cell carcinoma-induced mice show higher leptin receptor expression, and serum leptin level was increased in dysplasia group. Our findings suggest that leptin seems to exert an effect on oral squamous cell carcinoma cells behavior and also on molecular markers related to cell proliferation, migration, and tumor angiogenesis.

  16. Treatment with N- and C-Terminal Peptides of Parathyroid Hormone-Related Protein Partly Compensate the Skeletal Abnormalities in IGF-I Deficient Mice

    Science.gov (United States)

    Portal-Núñez, Sergio; Murillo-Cuesta, Silvia; Lozano, Daniel; Cediel, Rafael; Esbrit, Pedro

    2014-01-01

    Insulin-like growth factor-I (IGF-I) deficiency causes growth delay, and IGF-I has been shown to partially mediate bone anabolism by parathyroid hormone (PTH). PTH-related protein (PTHrP) is abundant in bone, and has osteogenic features by poorly defined mechanisms. We here examined the capacity of PTHrP (1–36) and PTHrP (107–111) (osteostatin) to reverse the skeletal alterations associated with IGF-I deficiency. Igf1-null mice and their wild type littermates were treated with each PTHrP peptide (80 µg/Kg/every other day/2 weeks; 2 males and 4 females for each genotype) or saline vehicle (3 males and 3 females for each genotype). We found that treatment with either PTHrP peptide ameliorated trabecular structure in the femur in both genotypes. However, these peptides were ineffective in normalizing the altered cortical structure at this bone site in Igf1-null mice. An aberrant gene expression of factors associated with osteoblast differentiation and function, namely runx2, osteoprotegerin/receptor activator of NF-κB ligand ratio, Wnt3a , cyclin D1, connexin 43, catalase and Gadd45, as well as in osteocyte sclerostin, was found in the long bones of Igf1-null mice. These mice also displayed a lower amount of trabecular osteoblasts and osteoclasts in the tibial metaphysis than those in wild type mice. These alterations in Igf1-null mice were only partially corrected by each PTHrP peptide treatment. The skeletal expression of Igf2, Igf1 receptor and Irs2 was increased in Igf1-null mice, and this compensatory profile was further improved by treatment with each PTHrP peptide related to ERK1/2 and FoxM1 activation. In vitro, PTHrP (1–36) and osteostatin were effective in promoting bone marrow stromal cell mineralization in normal mice but not in IGF-I-deficient mice. Collectively, these findings indicate that PTHrP (1–36) and osteostatin can exert several osteogenic actions even in the absence of IGF-I in the mouse bone. PMID:24503961

  17. Reducing inflammation and rescuing FTD-related behavioral deficits in progranulin-deficient mice with α7 nicotinic acetylcholine receptor agonists.

    Science.gov (United States)

    Minami, S Sakura; Shen, Vivian; Le, David; Krabbe, Grietje; Asgarov, Rustam; Perez-Celajes, Liberty; Lee, Chih-Hung; Li, Jinhe; Donnelly-Roberts, Diana; Gan, Li

    2015-10-15

    Mutations in the progranulin gene cause frontotemporal dementia (FTD), a debilitating neurodegenerative disease that involves atrophy of the frontal and temporal lobes and affects personality, behavior, and language. Progranulin-deficient mouse models of FTD exhibit deficits in compulsive and social behaviors reminiscent of patients with FTD, and develop excessive microgliosis and increased release of inflammatory cytokines. Activation of nicotinic acetylcholine receptors (nAChRs) by nicotine or specific α7 nAChR agonists reduces neuroinflammation. Here, we investigated whether activation of nAChRs by nicotine or α7 agonists improved the excessive inflammatory and behavioral phenotypes of a progranulin-deficient FTD mouse model. We found that treatment with selective α7 agonists, PHA-568487 or ABT-107, strongly suppressed the activation of NF-κB in progranulin-deficient cells. Treatment with ABT-107 also reduced microgliosis, decreased TNFα levels, and reduced compulsive behavior in progranulin-deficient mice. Collectively, these data suggest that targeting activation of the α7 nAChR pathway may be beneficial in decreasing neuroinflammation and reversing some of the behavioral deficits observed in progranulin-deficient FTD. Copyright © 2015. Published by Elsevier Inc.

  18. Toll-like receptor 2 or toll-like receptor 4 deficiency does not modify lupus in MRLlpr mice.

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    Simon J Freeley

    Full Text Available Systemic lupus erythematosus is an autoimmune disease with a high morbidity and nephritis is a common manifestation. Previous studies in murine lupus models have suggest a role for Toll-like receptor 2 and 4. We examined the role of these molecules in MRL lpr mice which is one of the most established and robust murine models. We compared disease parameters in Toll-like receptor 2 or Toll-like receptor 4 deficient mice with their littermate controls. We found no difference in the severity of glomerulonephritis as assessed by histology, serum creatinine and albuminuria when Toll-like receptor 2 or Toll-like receptor 4 deficient MRLlpr mice were compared with Toll-like receptor sufficient controls. We also found similar levels of anti-dsDNA and anti-ssDNA antibodies. These results show that Toll-like receptor 2 and Toll-like receptor 4 do not play a significant role in MRLlpr mice, and therefore they may not be important in human lupus.

  19. [Effects and mechanism of Angelicae Sinensis Radix on Th1/Th2 and Th17/Treg in mice with asthma and Yin deficiency syndrome].

    Science.gov (United States)

    Ma, Ting-Ting; Feng, Xing-Zhong; Wang, Xue-Yan

    2017-02-01

    Angelicae Sinensis Radix, with nourishing Yin, promoting blood circulation, and moisturizing dryness functions, is commonly used in clinical medicine. In order to investigate the effects and mechanism of Angelica sinensis(AS) on Th1/Th2 and Th17/Treg in mice with asthma and Yin deficiency syndrome, asthmatic and Yin deficiency syndrome Balb/c mice models were established by injecting and inhaling ovalbumin(OVA) and thyroxin. The models were treated with dexamethasone(DXM), AS extract and AS extract+DXM, respectively. Pathological examination of lung tissues was conducted by HE staining, and ELISA was used to detect the levels of IL-4, IL-17, IFN-γ, TGF-β as well as retinoic acid receptor-related orphan receptor (RORγt). Results showed that AS could significantly improve the situation of inflammation infiltration, increase ratios of IFN-γ/IL-4 and TGF-β/IL-17, decrease the levels of RORγt in lung tissues. The AS+DXM group showed a best treatment effect. The results indicated that AS played a therapeutic role for asthma with Yin deficiency syndrome and improved airway inflammation by inhibiting the expression of RORγt in lung tissues and regulating the balance of Th1/Th2 and Th17/Treg. Copyright© by the Chinese Pharmaceutical Association.

  20. Probiotics modulate gut microbiota and improve insulin sensitivity in DIO mice.

    Science.gov (United States)

    Bagarolli, Renata A; Tobar, Natália; Oliveira, Alexandre G; Araújo, Tiago G; Carvalho, Bruno M; Rocha, Guilherme Z; Vecina, Juliana F; Calisto, Kelly; Guadagnini, Dioze; Prada, Patrícia O; Santos, Andrey; Saad, Sara T O; Saad, Mario J A

    2017-12-01

    Obesity and type 2 diabetes are characterized by subclinical inflammatory process. Changes in composition or modulation of the gut microbiota may play an important role in the obesity-associated inflammatory process. In the current study, we evaluated the effects of probiotics (Lactobacillus rhamnosus, L. acidophilus and Bifidobacterium bifidumi) on gut microbiota, changes in permeability, and insulin sensitivity and signaling in high-fat diet and control animals. More importantly, we investigated the effects of these gut modulations on hypothalamic control of food intake, and insulin and leptin signaling. Swiss mice were submitted to a high-fat diet (HFD) with probiotics or pair-feeding for 5 weeks. Metagenome analyses were performed on DNA samples from mouse feces. Blood was drawn to determine levels of glucose, insulin, LPS, cytokines and GLP-1. Liver, muscle, ileum and hypothalamus tissue proteins were analyzed by Western blotting and real-time polymerase chain reaction. In addition, liver and adipose tissues were analyzed using histology and immunohistochemistry. The HFD induced huge alterations in gut microbiota accompanied by increased intestinal permeability, LPS translocation and systemic low-grade inflammation, resulting in decreased glucose tolerance and hyperphagic behavior. All these obesity-related features were reversed by changes in the gut microbiota profile induced by probiotics. Probiotics also induced an improvement in hypothalamic insulin and leptin resistance. Our data demonstrate that the intestinal microbiome is a key modulator of inflammatory and metabolic pathways in both peripheral and central tissues. These findings shed light on probiotics as an important tool to prevent and treat patients with obesity and insulin resistance. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Hypoxic Living and Exercise Training Alter Adipose Tissue Leptin/Leptin Receptor in Rats

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    Yingli Lu

    2016-11-01

    Full Text Available Background: Hypobaric hypoxia results in weight loss in obese individuals, and exercise training is advocated for the treatment of obesity and its related metabolic dysfunctions. The purpose of this study was to investigate the effects of hypoxic living and exercise training on obesity and adipose tissue leptin/leptin receptor in dietary-induced obese rats. Methods: One hundred and thirty high-fat diet fed Sprague-Dawley rats were assigned into one of the following groups (n=10 each: control, sedentary hypoxic living for 1 to 4 weeks (SH1, SH2, SH3, and SH4, living and exercise training in normoxic conditions for 1 to 4 weeks (TN1, TN2, TN3, and TN4, and living and exercise training in hypoxic conditions for 1 to 4 weeks (TN1, TN2, TN3, and TN4. Epididymal adipose tissue expression levels of leptin and leptin receptor were determined. Results: Compared to hypoxic living and living and exercise training in normoxic conditions, living and exercise training in hypoxic conditions for 3-4 weeks resulted in lower Lee index (P<0.05 to P<0.01, and higher expression of leptin and leptin receptor (P<0.05 to P<0.01 in adipose tissue. Conclusion: In a rodent model of altitude training, living and exercise training in hypoxic conditions resulted in greater alterations in obesity and adipose tissue leptin/leptin receptor than hypoxic living alone and living and exercise training in normoxic conditions.

  2. Leptin as well as Free Leptin Receptor Is Associated with Polycystic Ovary Syndrome in Young Women

    Science.gov (United States)

    Rizk, Nasser M.; Sharif, Elham

    2015-01-01

    Background and Aim. Leptin has two forms in the circulation: free and bound forms. The soluble leptin receptor (sOB-R) circulates in the blood and can bind to leptin. The aim of this study is to assess the concentrations of the leptin and the sOB-R in PCOS and its relation to adiposity, insulin resistance, and androgens. Methods. A cross-sectional study included 78 female students aged 17–25 years. Fasting serum leptin and sOB-R concentrations were measured. The anthropometric variables and the hormonal profile such as insulin, female and male sex hormones, and prolactin were assessed. Results. In PCOS, leptin level (ng/ml) and free leptin index (FLI) increased significantly while sOB-R (ng/ml) significantly decreased compared to control subjects. In age-matched subjects, obese PCOS had increased leptin level in ng/ml (median level with interquartile levels) of 45.67 (41.98–48.04) and decreased sOB-R in ng/ml 11.47 (7.59–16.44) compared to lean PCOS 16.97 (10.60–45.55) for leptin and 16.62 (11.61–17.96) for sOB-R with p values 0.013 and 0.042, respectively. However, body mass index (BMI) is significantly correlated with leptin and s-OBR, while no significant correlations with parameters of insulin resistance were detected. Conclusion. PCOS is associated with hyperleptinemia and increased free leptin index. Decreased sOB-R could be a compensatory mechanism for the defective action of leptin. PMID:26180527

  3. Leptin as well as Free Leptin Receptor Is Associated with Polycystic Ovary Syndrome in Young Women

    Directory of Open Access Journals (Sweden)

    Nasser M. Rizk

    2015-01-01

    Full Text Available Background and Aim. Leptin has two forms in the circulation: free and bound forms. The soluble leptin receptor (sOB-R circulates in the blood and can bind to leptin. The aim of this study is to assess the concentrations of the leptin and the sOB-R in PCOS and its relation to adiposity, insulin resistance, and androgens. Methods. A cross-sectional study included 78 female students aged 17–25 years. Fasting serum leptin and sOB-R concentrations were measured. The anthropometric variables and the hormonal profile such as insulin, female and male sex hormones, and prolactin were assessed. Results. In PCOS, leptin level (ng/ml and free leptin index (FLI increased significantly while sOB-R (ng/ml significantly decreased compared to control subjects. In age-matched subjects, obese PCOS had increased leptin level in ng/ml (median level with interquartile levels of 45.67 (41.98–48.04 and decreased sOB-R in ng/ml 11.47 (7.59–16.44 compared to lean PCOS 16.97 (10.60–45.55 for leptin and 16.62 (11.61–17.96 for sOB-R with p values 0.013 and 0.042, respectively. However, body mass index (BMI is significantly correlated with leptin and s-OBR, while no significant correlations with parameters of insulin resistance were detected. Conclusion. PCOS is associated with hyperleptinemia and increased free leptin index. Decreased sOB-R could be a compensatory mechanism for the defective action of leptin.

  4. 45 CFR 1304.60 - Deficiencies and quality improvement plans.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Deficiencies and quality improvement plans. 1304... must correct the deficiency either immediately or pursuant to a Quality Improvement Plan. (c) An Early... Improvement Plan must submit to the responsible HHS official a Quality Improvement Plan specifying, for each...

  5. Using "Mighty Mouse" to understand masticatory plasticity: myostatin-deficient mice and musculoskeletal function.

    Science.gov (United States)

    Ravosa, Matthew J; López, Elisabeth K; Menegaz, Rachel A; Stock, Stuart R; Stack, M Sharon; Hamrick, Mark W

    2008-09-01

    Knockout mice lacking myostatin (Mstn), a negative regulator of the growth of skeletal muscle, develop significant increases in the relative mass of masticatory muscles as well as the ability to generate higher maximal muscle forces. Wild-type and Mstn-deficient mice were compared to investigate the postnatal influence of elevated masticatory loads due to increased jaw-adductor and bite forces on the biomineralization of mandibular articular and cortical bone, the internal structure of the jaw joints, and the composition of temporomandibular joint (TMJ) articular cartilage. To provide an interspecific perspective on the long-term responses of mammalian jaw joints to altered loading conditions, the findings on mice were compared to similar data for growing rabbits subjected to long-term dietary manipulation. Statistically significant differences in joint proportions and bone mineral density between normal and Mstn-deficient mice, which are similar to those observed between rabbit loading cohorts, underscore the need for a comprehensive analysis of masticatory tissue plasticity vis-à-vis altered mechanical loads, one in which variation in external and internal structure are considered. Differences in the expression of proteoglycans and type-II collagen in TMJ articular cartilage between the mouse and rabbit comparisons suggest that the duration and magnitude of the loading stimulus will significantly affect patterns of adaptive and degradative responses. These data on mammals subjected to long-term loading conditions offer novel insights regarding variation in ontogeny, life history, and the ecomorphology of the feeding apparatus.

  6. Alteration of brain insulin and leptin signaling promotes energy homeostasis impairment and neurodegenerative diseases

    Directory of Open Access Journals (Sweden)

    Taouis Mohammed

    2011-09-01

    cerebrospinal fluid of AD patients is diminished. Taken together, these data clearly links deficiency of leptin and insulin signaling to both alterations of energy homeostasis control and predisposition to AD. Furthermore, environment changes leading to insulin and leptin-resistance may promote these defects, such as high fat diet.

  7. Kinetics of leptin binding to the Q223R leptin receptor.

    Directory of Open Access Journals (Sweden)

    Hans Verkerke

    Full Text Available Studies in human populations and mouse models of disease have linked the common leptin receptor Q223R mutation to obesity, multiple forms of cancer, adverse drug reactions, and susceptibility to enteric and respiratory infections. Contradictory results cast doubt on the phenotypic consequences of this variant. We set out to determine whether the Q223R substitution affects leptin binding kinetics using surface plasmon resonance (SPR, a technique that allows sensitive real-time monitoring of protein-protein interactions. We measured the binding and dissociation rate constants for leptin to the extracellular domain of WT and Q223R murine leptin receptors expressed as Fc-fusion proteins and found that the mutant receptor does not significantly differ in kinetics of leptin binding from the WT leptin receptor. (WT: ka 1.76×106±0.193×106 M-1 s-1, kd 1.21×10-4±0.707×10-4 s-1, KD 6.47×10-11±3.30×10-11 M; Q223R: ka 1.75×106±0.0245×106 M-1 s-1, kd 1.47×10-4±0.0505×10-4 s-1, KD 8.43×10-11±0.407×10-11 M. Our results support earlier findings that differences in affinity and kinetics of leptin binding are unlikely to explain mechanistically the phenotypes that have been linked to this common genetic variant. Future studies will seek to elucidate the mechanism by which this mutation influences susceptibility to metabolic, infectious, and malignant pathologies.

  8. Methamphetamine Increases Locomotion and Dopamine Transporter Activity in Dopamine D5 Receptor-Deficient Mice

    OpenAIRE

    Hayashizaki, Seiji; Hirai, Shinobu; Ito, Yumi; Honda, Yoshiko; Arime, Yosefu; Sora, Ichiro; Okado, Haruo; Kodama, Tohru; Takada, Masahiko

    2013-01-01

    Dopamine regulates the psychomotor stimulant activities of amphetamine-like substances in the brain. The effects of dopamine are mediated through five known dopamine receptor subtypes in mammals. The functional relevance of D5 dopamine receptors in the central nervous system is not well understood. To determine the functional relevance of D5 dopamine receptors, we created D5 dopamine receptor-deficient mice and then used these mice to assess the roles of D5 dopamine receptors in the behaviora...

  9. Caspase-1 deficiency in mice reduces intestinal triglyceride absorption and hepatic triglyceride secretion

    NARCIS (Netherlands)

    Diepen, J.A. van; Stienstra, R.; Vroegrijk, I.O.C.M.; Berg, S.A.A. van den; Salvatori, D.; Hooiveld, G.J.; Kersten, S.; Tack, C.J.; Netea, M.G.; Smit, J.W.A.; Joosten, L.A.B.; Havekes, L.M.; Dijk, K.W. van; Rensen, P.C.N.

    2013-01-01

    Caspase-1 is known to activate the proinflammatory cytokines IL-1β and IL-18. Additionally, it can cleave other substrates, including proteins involved in metabolism. Recently, we showed that caspase-1 deficiency in mice strongly reduces high-fat diet-induced weight gain, at least partly caused by

  10. New function for an old enzyme: NEP deficient mice develop late-onset obesity.

    Directory of Open Access Journals (Sweden)

    Matthias Becker

    Full Text Available BACKGROUND: According to the World Health Organization (WHO there is a pandemic of obesity with approximately 300 million people being obese. Typically, human obesity has a polygenetic causation. Neutral endopeptidase (NEP, also known as neprilysin, is considered to be one of the key enzymes in the metabolism of many active peptide hormones. METHODOLOGY/PRINCIPAL FINDINGS: An incidental observation in NEP-deficient mice was a late-onset excessive gain in body weight exclusively from a ubiquitous accumulation of fat tissue. In accord with polygenetic human obesity, mice were characterized by deregulation of lipid metabolism, higher blood glucose levels, with impaired glucose tolerance. The key role of NEP in determining body mass was confirmed by the use of the NEP inhibitor candoxatril in wild-type mice that increased body weight due to increased food intake. This is a peripheral and not a central NEP action on the switch for appetite control, since candoxatril cannot cross the blood-brain barrier. Furthermore, we demonstrated that inhibition of NEP in mice with cachexia delayed rapid body weight loss. Thus, lack in NEP activity, genetically or pharmacologically, leads to a gain in body fat. CONCLUSIONS/SIGNIFICANCE: In the present study, we have identified NEP to be a crucial player in the development of obesity. NEP-deficient mice start to become obese under a normocaloric diet in an age of 6-7 months and thus are an ideal model for the typical human late-onset obesity. Therefore, the described obesity model is an ideal tool for research on development, molecular mechanisms, diagnosis, and therapy of the pandemic obesity.

  11. Delayed allogeneic skin graft rejection in CD26-deficient mice.

    Science.gov (United States)

    Zhao, Xiangli; Zhang, Kai; Daniel, Peter; Wisbrun, Natali; Fuchs, Hendrik; Fan, Hua

    2018-03-23

    Organ transplantation is an effective therapeutic tool for treating many terminal diseases. However, one of the biggest challenges of transplantation is determining how to achieve the long-term survival of the allogeneic or xenogeneic transplant by, for example, preventing transplant rejection. In the current study, CD26 gene-knockout mice were used to investigate the potential role of CD26/dipeptidyl peptidase-4 (DPPIV) in allogeneic skin graft rejection by tail-skin transplantation. Compared with wild-type (CD26 +/+ ) counterparts, CD26 -/- mice showed reduced necrosis of grafts and delayed graft rejection after skin transplantation. Concentrations of serum IgG, including its subclasses IgG1 and IgG2a, were significantly reduced in CD26 -/- mice during graft rejection. Moreover, after allogeneic skin transplantation, the secretion levels of the cytokines IFN-γ, IL-2, IL-6, IL-4, and IL-13 were significantly reduced, whereas the level of the cytokine IL-10 was increased in the serum of CD26 -/- mice compared with that in the serum of CD26 +/+ mice. Additionally, the concentration of IL-17 in serum and the percentage of cells secreting IL-17 in mouse peripheral blood lymphocytes (MPBLs) were both significantly lower, while the percentage of regulatory T cells (Tregs) was significantly higher in MPBLs of CD26 -/- mice than in those of CD26 +/+ mice. Furthermore, a lower percentage of CD8 + T cells in MPBLs and fewer infiltrated macrophages and T cells in graft tissues of CD26 -/- mice were detected during graft rejection. These results indicate that CD26 is involved in allogeneic skin graft rejection and provides another hint that CD26 deficiency leads to less rejection due to lower activation and proliferation of host immune cells.

  12. Integral Role of PTP1B in Adiponectin-Mediated Inhibition of Oncogenic Actions of Leptin in Breast Carcinogenesis

    Directory of Open Access Journals (Sweden)

    LaTonia Taliaferro-Smith

    2013-01-01

    Full Text Available The molecular effects of obesity are mediated by alterations in the levels of adipocytokines. High leptin level associated with obese state is a major cause of breast cancer progression and metastasis, whereas adiponectin is considered a “guardian angel adipocytokine” for its protective role against various obesity-related pathogenesis including breast cancer. In the present study, investigating the role of adiponectin as a potential inhibitor of leptin, we show that adiponectin treatment inhibits leptin-induced clonogenicity and anchorage-independent growth. Leptin-stimulated migration and invasion of breast cancer cells is also effectively inhibited by adiponectin. Analyses of the underlying molecular mechanisms reveal that adiponectin suppresses activation of two canonical signaling molecules of leptin signaling axis: extracellular signal-regulated kinase (ERK and Akt. Pretreatment of breast cancer cells with adiponectin protects against leptin-induced activation of ERK and Akt. Adiponectin increases expression and activity of the physiological inhibitor of leptin signaling, protein tyrosine phosphatase 1B (PTP1B, which is found to be integral to leptin-antagonist function of adiponectin. Inhibition of PTP1B blocks adiponectin-mediated inhibition of leptin-induced breast cancer growth. Our in vivo studies show that adenovirus-mediated adiponectin treatment substantially reduces leptin-induced mammary tumorigenesis in nude mice. Exploring therapeutic strategies, we demonstrate that treatment of breast cancer cells with rosiglitazone results in increased adiponectin expression and inhibition of migration and invasion. Rosiglitazone treatment also inhibits leptin-induced growth of breast cancer cells. Taken together, these data show that adiponectin treatment can inhibit the oncogenic actions of leptin through blocking its downstream signaling molecules and raising adiponectin levels could be a rational therapeutic strategy for breast

  13. Ghrelin did not change coronary angiogenesis in diet-induced obese mice.

    Science.gov (United States)

    Khazaei, M; Tahergorabi, Z

    2017-02-28

    Ghrelin is a 28 amino acids peptide that initially was recognized as an endogenous ligand for growth hormone secretagogue receptor (GHSR). Recently, a number of studies demonstrated that ghrelin is a cardiovascular hormone with a series cardiovascular effect. The main objective of this study was to investigate the effect of systemic ghrelin administration on angiogenesis in the heart and its correlation with serum leptin levels in normal and diet-induced obese mice. 24 male C57BL/6 mice were randomly divided into four groups: normal diet (ND) or control, ND+ghrelin, high-fat-diet (HFD) or obese and HFD+ghrelin (n=6/group). Obese and control groups received HFD or ND, respectively, for 14 weeks. Then, the ghrelin was injected subcutaneously 100µg/kg twice daily. After 10 days, the animals were sacrificed, blood samples were taken and the hearts were removed. The angiogenic response in the heart was assessed by immunohisochemical staining. HFD significantly increased angiogenesis in the heart expressed as the number of CD31 positive cells than standard diet. Ghrelin did not alter angiogenesis in the heart in both obese and control groups, however, it reduced serum nitric oxide (NO) and leptin levels in obese mice. There was a strong positive correlation between the number of CD31 positive cells and serum leptin concentration (r=0.74). Leptin as an angiogenic factor has a positive correlation with angiogenesis in the heart. Although systemic administration of ghrelin reduced serum leptin and NO levels in obese mice, however, it could not alter coronary angiogenesis.

  14. Altered gut microbiota and endocannabinoid system tone in obese and diabetic leptin-resistant mice: impact on apelin regulation in adipose tissue

    Directory of Open Access Journals (Sweden)

    Lucie eGeurts

    2011-07-01

    Full Text Available Growing evidence supports the role of gut microbiota in the development of obesity, type 2 diabetes and low-grade inflammation. The endocrine activity of adipose tissue has been found to contribute to the regulation of glucose homeostasis and low-grade inflammation. Among the key hormones produced by this tissue, apelin has been shown to regulate glucose homeostasis. Recently, it has been proposed that gut microbiota participate in adipose tissue metabolism via the endocannabinoid system and gut microbiota-derived compounds, namely lipopolysaccharide (LPS. We have investigated gut microbiota composition in obese and diabetic leptin-resistant mice (db/db by combining pyrosequencing and phylogenetic microarray analysis of 16S ribosomal RNA gene sequences. We observed a significant higher abundance of Firmicutes, Proteobacteria and Fibrobacteres phyla in db/db mice compared to lean mice. The abundance of 10 genera was significantly affected by the genotype. We identified the roles of the endocannabinoid system and LPS in the regulation of apelinergic system tone (apelin and APJ mRNA expression in genetic obese and diabetic mice. By using in vivo and in vitro models, we have demonstrated that both the endocannabinoid system and low-grade inflammation differentially regulate apelin and APJ mRNA expression in adipose tissue. Finally, deep-gut microbiota profiling revealed that the gut microbial community of type 2 diabetic mice is significantly different from that of their lean counterparts. This indicates specific relationships between the gut microbiota and the regulation of the apelinergic system. However, the exact roles of specific bacteria in shaping the phenotype of db/db mice remain to be determined.

  15. Hematopoietic Kit Deficiency, rather than Lack of Mast Cells, Protects Mice from Obesity and Insulin Resistance.

    Science.gov (United States)

    Gutierrez, Dario A; Muralidhar, Sathya; Feyerabend, Thorsten B; Herzig, Stephan; Rodewald, Hans-Reimer

    2015-05-05

    Obesity, insulin resistance, and related pathologies are associated with immune-mediated chronic inflammation. Kit mutant mice are protected from diet-induced obesity and associated co-morbidities, and this phenotype has previously been attributed to their lack of mast cells. We performed a comprehensive metabolic analysis of Kit-dependent Kit(W/Wv) and Kit-independent Cpa3(Cre/+) mast-cell-deficient mouse strains, employing diet-induced or genetic (Lep(Ob/Ob) background) models of obesity. Our results show that mast cell deficiency, in the absence of Kit mutations, plays no role in the regulation of weight gain or insulin resistance. Moreover, we provide evidence that the metabolic phenotype observed in Kit mutant mice, while independent of mast cells, is immune regulated. Our data underscore the value of definitive mast cell deficiency models to conclusively test the involvement of this enigmatic cell in immune-mediated pathologies and identify Kit as a key hematopoietic factor in the pathogenesis of metabolic syndrome. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Effect of ultraviolet irradiation on mast cell-deficient W/Wv mice

    International Nuclear Information System (INIS)

    Ikai, K.; Danno, K.; Horio, T.; Narumiya, S.

    1985-01-01

    The effect of UV irradiation on the skin was investigated in (WB-W/+) X (C57BL/6J-Wv/+)F1-W/Wv mice, which are genetically deficient in tissue mast cells. Their congenic littermates (+/+) and normal albino mice (ICR or BALB/c) were used as controls. Mice were irradiated with 500 mJ/cm2 of UVB and the increment of ear thickness was measured before and 6, 12, and 24 h after irradiation. Ear swelling in W/Wv mice at 12 and 24 h after irradiation was significantly smaller than that in +/+ and ICR mice. In contrast, the number of sunburn cells formed 24 h after UVB irradiation (200 or 500 mJ/cm2) was similar in W/Wv, +/+ and ICR mice. On the other hand, when mice were treated with 8-methoxy-psoralen (0.5%) plus UVA irradiation (4 J/cm2) (topical PUVA), ears of W/Wv and BALB/c mice, which were both white in color, were thickened similarly 72 h after treatment, but less swelling was observed in +/+ mice, which were black in skin color. The amount of prostaglandin D2 (PGD2) in ears, determined by radioimmunoassay specific for PGD2, was elevated 3-fold in +/+ and ICR mice at 3 h after irradiation with 500 mJ/cm2 of UVB in comparison with basal level without irradiation. However, such elevation was not observed in W/Wv mice. These results suggest that mast cells play an important role in UVB-induced inflammation, and PGs from mast cells are responsible at least in part for the development of this reaction. However, neither mast cells nor PGs contribute to the sunburn cell formation and ear swelling response by PUVA treatment

  17. Impaired inflammatory response and increased oxidative stress and neurodegeneration after brain injury in interleukin-6-deficient mice

    DEFF Research Database (Denmark)

    Penkowa, M; Giralt, M; Carrasco, J

    2000-01-01

    of the antioxidants Cu/Zn-superoxide dismutase (Cu/Zn-SOD), Mn-SOD, and catalase remained unaffected by the IL-6 deficiency. The lesioned mice showed increased oxidative stress, as judged by malondialdehyde (MDA) and nitrotyrosine (NITT) levels and by formation of inducible nitric oxide synthase (iNOS). IL-6KO mice...

  18. Acceleration of bone development and regeneration through the Wnt/β-catenin signaling pathway in mice heterozygously deficient for GSK-3β

    International Nuclear Information System (INIS)

    Arioka, Masaki; Takahashi-Yanaga, Fumi; Sasaki, Masanori; Yoshihara, Tatsuya; Morimoto, Sachio; Takashima, Akihiko; Mori, Yoshihide; Sasaguri, Toshiyuki

    2013-01-01

    Highlights: •The Wnt/β-catenin signaling pathway was activated in GSK-3β +/− mice. •The cortical and trabecular bone volumes were increased in GSK-3β +/− mice. •Regeneration of a partial bone defect was accelerated in GSK-3β +/− mice. -- Abstract: Glycogen synthase kinase (GSK)-3β plays an important role in osteoblastogenesis by regulating the Wnt/β-catenin signaling pathway. Therefore, we investigated whether GSK-3β deficiency affects bone development and regeneration using mice heterozygously deficient for GSK-3β (GSK-3β +/− ). The amounts of β-catenin, c-Myc, cyclin D1, and runt-related transcription factor-2 (Runx2) in the bone marrow cells of GSK-3β +/− mice were significantly increased compared with those of wild-type mice, indicating that Wnt/β-catenin signals were enhanced in GSK-3β +/− mice. Microcomputed tomography of the distal femoral metaphyses demonstrated that the volumes of both the cortical and trabecular bones were increased in GSK-3β +/− mice compared with those in wild-type mice. Subsequently, to investigate the effect of GSK-3β deficiency on bone regeneration, we established a partial bone defect in the femur and observed new bone at 14 days after surgery. The volume and mineral density of the new bone were significantly higher in GSK-3β +/− mice than those in wild-type mice. These results suggest that bone formation and regeneration in vivo are accelerated by inhibition of GSK-3β, probably through activation of the Wnt/β-catenin signaling pathway

  19. Black bear parathyroid hormone has greater anabolic effects on trabecular bone in dystrophin-deficient mice than in wild type mice.

    Science.gov (United States)

    Gray, Sarah K; McGee-Lawrence, Meghan E; Sanders, Jennifer L; Condon, Keith W; Tsai, Chung-Jui; Donahue, Seth W

    2012-09-01

    Duchenne muscular dystrophy (DMD) is an X-linked neuromuscular disease that has deleterious consequences in muscle and bone, leading to decreased mobility, progressive osteoporosis, and premature death. Patients with DMD experience a higher-than-average fracture rate, particularly in the proximal and distal femur and proximal tibia. The dystrophin-deficient mdx mouse is a model of DMD that demonstrates muscle degeneration and fibrosis and osteoporosis. Parathyroid hormone, an effective anabolic agent for post-menopausal and glucocorticoid-induced osteoporosis, has not been explored for DMD. Black bear parathyroid hormone (bbPTH) has been implicated in the maintenance of bone properties during extended periods of disuse (hibernation). We cloned bbPTH and found 9 amino acid residue differences from human PTH. Apoptosis was mitigated and cAMP was activated by bbPTH in osteoblast cultures. We administered 28nmol/kg of bbPTH 1-84 to 4-week old male mdx and wild type mice via daily (5×/week) subcutaneous injection for 6 weeks. Vehicle-treated mdx mice had 44% lower trabecular bone volume fraction than wild type mice. No changes were found in femoral cortical bone geometry or mechanical properties with bbPTH treatment in wild type mice, and only medio-lateral moment of inertia changed with bbPTH treatment in mdx femurs. However, μCT analyses of the trabecular regions of the distal femur and proximal tibia showed marked increases in bone volume fraction with bbPTH treatment, with a greater anabolic response (7-fold increase) in mdx mice than wild type mice (2-fold increase). Trabecular number increased in mdx long bone, but not wild type bone. Additionally, greater osteoblast area and decreased osteoclast area were observed with bbPTH treatment in mdx mice. The heightened response to PTH in mdx bone compared to wild type suggests a link between dystrophin deficiency, altered calcium signaling, and bone. These findings support further investigation of PTH as an anabolic

  20. Gene expression deregulation in postnatal skeletal muscle of TK2 deficient mice reveals a lower pool of proliferating myogenic progenitor cells.

    Directory of Open Access Journals (Sweden)

    João A Paredes

    Full Text Available Loss of thymidine kinase 2 (TK2 causes a heterogeneous myopathic form of mitochondrial DNA (mtDNA depletion syndrome (MDS in humans that predominantly affects skeletal muscle tissue. In mice, TK2 deficiency also affects several tissues in addition to skeletal muscle, including brain, heart, adipose tissue, kidneys and causes death about 3 weeks after birth. We analysed skeletal muscle and heart muscle tissues of Tk2 knockout mice at postnatal development phase and observed that TK2 deficient pups grew slower and their skeletal muscles appeared significantly underdeveloped, whereas heart was close to normal in size. Both tissues showed mtDNA depletion and mitochondria with altered ultrastructure, as revealed by transmission electron microscopy. Gene expression microarray analysis showed a strong down-regulation of genes involved in cell cycle and cell proliferation in both tissues, suggesting a lower pool of undifferentiated proliferating cells. Analysis of isolated primary myoblasts from Tk2 knockout mice showed slow proliferation, less ability to differentiate and signs of premature senescence, even in absence of mtDNA depletion. Our data demonstrate that TK2 deficiency disturbs myogenic progenitor cells function in postnatal skeletal muscle and we propose this as one of the causes of underdeveloped phenotype and myopathic characteristic of the TK2 deficient mice, in addition to the progressive mtDNA depletion, mitochondrial damage and respiratory chain deficiency in post-mitotic differentiated tissue.

  1. Gene expression deregulation in postnatal skeletal muscle of TK2 deficient mice reveals a lower pool of proliferating myogenic progenitor cells.

    Science.gov (United States)

    Paredes, João A; Zhou, Xiaoshan; Höglund, Stefan; Karlsson, Anna

    2013-01-01

    Loss of thymidine kinase 2 (TK2) causes a heterogeneous myopathic form of mitochondrial DNA (mtDNA) depletion syndrome (MDS) in humans that predominantly affects skeletal muscle tissue. In mice, TK2 deficiency also affects several tissues in addition to skeletal muscle, including brain, heart, adipose tissue, kidneys and causes death about 3 weeks after birth. We analysed skeletal muscle and heart muscle tissues of Tk2 knockout mice at postnatal development phase and observed that TK2 deficient pups grew slower and their skeletal muscles appeared significantly underdeveloped, whereas heart was close to normal in size. Both tissues showed mtDNA depletion and mitochondria with altered ultrastructure, as revealed by transmission electron microscopy. Gene expression microarray analysis showed a strong down-regulation of genes involved in cell cycle and cell proliferation in both tissues, suggesting a lower pool of undifferentiated proliferating cells. Analysis of isolated primary myoblasts from Tk2 knockout mice showed slow proliferation, less ability to differentiate and signs of premature senescence, even in absence of mtDNA depletion. Our data demonstrate that TK2 deficiency disturbs myogenic progenitor cells function in postnatal skeletal muscle and we propose this as one of the causes of underdeveloped phenotype and myopathic characteristic of the TK2 deficient mice, in addition to the progressive mtDNA depletion, mitochondrial damage and respiratory chain deficiency in post-mitotic differentiated tissue.

  2. Metabolomics of the Wolfram Syndrome 1 Gene (Wfs1) Deficient Mice.

    Science.gov (United States)

    Porosk, Rando; Terasmaa, Anton; Mahlapuu, Riina; Soomets, Ursel; Kilk, Kalle

    2017-12-01

    Wolfram syndrome 1 is a rare autosomal recessive neurodegenerative disease characterized by diabetes insipidus, diabetes mellitus, optic atrophy, and deafness. Mutations in the WFS1 gene encoding the wolframin glycoprotein can lead to endoplasmic reticulum stress and unfolded protein responses in cells, but the pathophysiology at whole organism level is poorly understood. In this study, several organs (heart, liver, kidneys, and pancreas) and bodily fluids (trunk blood and urine) of 2- and 6-month old Wfs1 knockout (KO), heterozygote (HZ), and wild-type (WT) mice were analyzed by untargeted and targeted metabolomics using liquid chromatography-mass spectrometry. The key findings were significant perturbations in the metabolism of pancreas and heart before the onset of related clinical signs such as glycosuria that precedes hyperglycemia and thus implies a kidney dysfunction before the onset of classical diabetic nephropathy. The glucose use and gluconeogenesis in KO mice are intensified in early stages, but later the energetic needs are mainly covered by lipolysis. Furthermore, in young mice liver and trunk blood hypouricemia, which in time turns to hyperuricemia, was detected. In summary, we show that the metabolism in Wfs1-deficient mice markedly differs from the metabolism of WT mice in many aspects and discuss the future biological and clinical relevance of these observations.

  3. Leptin: A biomarker for sleep disorders?

    OpenAIRE

    Pan, Weihong; Kastin, Abba J.

    2013-01-01

    Leptin, a pleiotropic protein hormone produced mainly by fat cells, regulates metabolic activity and many other physiological functions. The intrinsic circadian rhythm of blood leptin is modulated by gender, development, feeding, fasting, sleep, obesity, and endocrine disorders. Hyperleptinemia is implicated in leptin resistance. To determine the specificity and sensitivity of leptin concentrations in sleep disorders, we summarize here the alterations of leptin in four conditions in animal an...

  4. Metastasis of transgenic breast cancer in plasminogen activator inhibitor-1 gene-deficient mice

    DEFF Research Database (Denmark)

    Almholt, Kasper; Nielsen, Boye Schnack; Frandsen, Thomas Leth

    2003-01-01

    , high levels of PAI-1 as well as uPA are equally associated with poor prognosis in cancer patients. PAI-1 is thought to play a vital role for the controlled extracellular proteolysis during tumor neovascularization. We have studied the effect of PAI-1 deficiency in a transgenic mouse model...... of metastasizing breast cancer. In these tumors, the expression pattern of uPA and PAI-1 resembles that of human ductal breast cancer and plasminogen is required for efficient metastasis. In a cohort of 63 transgenic mice that were either PAI-1-deficient or wild-type sibling controls, primary tumor growth...

  5. Leptin regulates glutamate and glucose transporters in hypothalamic astrocytes

    Science.gov (United States)

    Fuente-Martín, Esther; García-Cáceres, Cristina; Granado, Miriam; de Ceballos, María L.; Sánchez-Garrido, Miguel Ángel; Sarman, Beatrix; Liu, Zhong-Wu; Dietrich, Marcelo O.; Tena-Sempere, Manuel; Argente-Arizón, Pilar; Díaz, Francisca; Argente, Jesús; Horvath, Tamas L.; Chowen, Julie A.

    2012-01-01

    Glial cells perform critical functions that alter the metabolism and activity of neurons, and there is increasing interest in their role in appetite and energy balance. Leptin, a key regulator of appetite and metabolism, has previously been reported to influence glial structural proteins and morphology. Here, we demonstrate that metabolic status and leptin also modify astrocyte-specific glutamate and glucose transporters, indicating that metabolic signals influence synaptic efficacy and glucose uptake and, ultimately, neuronal function. We found that basal and glucose-stimulated electrical activity of hypothalamic proopiomelanocortin (POMC) neurons in mice were altered in the offspring of mothers fed a high-fat diet. In adulthood, increased body weight and fasting also altered the expression of glucose and glutamate transporters. These results demonstrate that whole-organism metabolism alters hypothalamic glial cell activity and suggest that these cells play an important role in the pathology of obesity. PMID:23064363

  6. Phocid seal leptin: tertiary structure and hydrophobic receptor binding site preservation during distinct leptin gene evolution.

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    John A Hammond

    Full Text Available The cytokine hormone leptin is a key signalling molecule in many pathways that control physiological functions. Although leptin demonstrates structural conservation in mammals, there is evidence of positive selection in primates, lagomorphs and chiropterans. We previously reported that the leptin genes of the grey and harbour seals (phocids have significantly diverged from other mammals. Therefore we further investigated the diversification of leptin in phocids, other marine mammals and terrestrial taxa by sequencing the leptin genes of representative species. Phylogenetic reconstruction revealed that leptin diversification was pronounced within the phocid seals with a high dN/dS ratio of 2.8, indicating positive selection. We found significant evidence of positive selection along the branch leading to the phocids, within the phocid clade, but not over the dataset as a whole. Structural predictions indicate that the individual residues under selection are away from the leptin receptor (LEPR binding site. Predictions of the surface electrostatic potential indicate that phocid seal leptin is notably different to other mammalian leptins, including the otariids. Cloning the grey seal leptin binding domain of LEPR confirmed that this was structurally conserved. These data, viewed in toto, support a hypothesis that phocid leptin divergence is unlikely to have arisen by random mutation. Based upon these phylogenetic and structural assessments, and considering the comparative physiology and varying life histories among species, we postulate that the unique phocid diving behaviour has produced this selection pressure. The Phocidae includes some of the deepest diving species, yet have the least modified lung structure to cope with pressure and volume changes experienced at depth. Therefore, greater surfactant production is required to facilitate rapid lung re-inflation upon surfacing, while maintaining patent airways. We suggest that this additional

  7. Adult exposure to tributyltin affects hypothalamic neuropeptide Y, Y1 receptor distribution, and circulating leptin in mice.

    Science.gov (United States)

    Bo, E; Farinetti, A; Marraudino, M; Sterchele, D; Eva, C; Gotti, S; Panzica, G

    2016-07-01

    Tributyltin (TBT), a pesticide used in antifouling paints, is toxic for aquatic invertebrates. In vertebrates, TBT may act in obesogen- inducing adipogenetic gene transcription for adipocyte differentiation. In a previous study, we demonstrated that acute administration of TBT induces c-fos expression in the arcuate nucleus. Therefore, in this study, we tested the hypothesis that adult exposure to TBT may alter a part of the nervous pathways controlling animal food intake. In particular, we investigated the expression of neuropeptide Y (NPY) immunoreactivity. This neuropeptide forms neural circuits dedicated to food assumption and its action is mediated by Y1 receptors that are widely expressed in the hypothalamic nuclei responsible for the regulation of food intake and energy homeostasis. To this purpose, TBT was orally administered at a dose of 0.025 mg/kg/day/body weight to adult animals [male and female C57BL/6 (Y1-LacZ transgenic mice] for 4 weeks. No differences were found in body weight and fat deposition, but we observed a significant increase in feed efficiency in TBT-treated male mice and a significant decrease in circulating leptin in both sexes. Computerized quantitative analysis of NPY immunoreactivity and Y1-related β-galactosidase activity demonstrated a statistically significant reduction in NPY and Y1 transgene expression in the hypothalamic circuit controlling food intake of treated male mice in comparison with controls. In conclusion, the present results indicate that adult exposure to TBT is profoundly interfering with the nervous circuits involved in the stimulation of food intake. © 2016 American Society of Andrology and European Academy of Andrology.

  8. Differential effects of silver nanoparticles on DNA damage and DNA repair gene expression in Ogg1-deficient and wild type mice.

    Science.gov (United States)

    Nallanthighal, Sameera; Chan, Cadia; Murray, Thomas M; Mosier, Aaron P; Cady, Nathaniel C; Reliene, Ramune

    2017-10-01

    Due to extensive use in consumer goods, it is important to understand the genotoxicity of silver nanoparticles (AgNPs) and identify susceptible populations. 8-Oxoguanine DNA glycosylase 1 (OGG1) excises 8-oxo-7,8-dihydro-2-deoxyguanine (8-oxoG), a pro-mutagenic lesion induced by oxidative stress. To understand whether defects in OGG1 is a possible genetic factor increasing an individual's susceptibly to AgNPs, we determined DNA damage, genome rearrangements, and expression of DNA repair genes in Ogg1-deficient and wild type mice exposed orally to 4 mg/kg of citrate-coated AgNPs over a period of 7 d. DNA damage was examined at 3 and 7 d of exposure and 7 and 14 d post-exposure. AgNPs induced 8-oxoG, double strand breaks (DSBs), chromosomal damage, and DNA deletions in both genotypes. However, 8-oxoG was induced earlier in Ogg1-deficient mice and 8-oxoG levels were higher after 7-d treatment and persisted longer after exposure termination. AgNPs downregulated DNA glycosylases Ogg1, Neil1, and Neil2 in wild type mice, but upregulated Myh, Neil1, and Neil2 glycosylases in Ogg1-deficient mice. Neil1 and Neil2 can repair 8-oxoG. Thus, AgNP-mediated downregulation of DNA glycosylases in wild type mice may contribute to genotoxicity, while upregulation thereof in Ogg1-deficient mice could serve as an adaptive response to AgNP-induced DNA damage. However, our data show that Ogg1 is indispensable for the efficient repair of AgNP-induced damage. In summary, citrate-coated AgNPs are genotoxic in both genotypes and Ogg1 deficiency exacerbates the effect. These data suggest that humans with genetic polymorphisms and mutations in OGG1 may have increased susceptibility to AgNP-mediated DNA damage.

  9. Should leptin replace insulin as a lifetime monotherapy for diabetes type 1 and 2?

    Science.gov (United States)

    Kalra, Satya P

    2013-10-01

    Evidence accumulated during the last decade has affirmed that adipocyte leptin insufficiency in the hypothalamus is the primary etiological factor in the pathogenesis of diabetes type 1 and 2 and related metabolic morbidities. Leptin insufficiency disrupts the relay of hypothalamic regulatory information along three descending pathways to the organs in the periphery that normally participate in maintenance of glucose homeostasis on a minute-to-minute basis throughout lifetime. Reinstatement of leptin sufficiency in the hypothalamus by either systemic or central injections, or its provision selectively in the hypothalamus with the aid of gene therapy extinguished hyperglycemia and normalized blood glucose stably during the entire course of treatment in a variety of animal models of diabetes type 1 and 2. In follow-up clinical trials, twice daily leptin treatment in leptinopenic and insulinopenic type 1 diabetics and leptinopenic and hyperinsulinemic type 2 diabetics with congenital lipodystrophy or acquired lipoatrophy normalized blood glucose without any discernible adverse effects during the extended course of treatment. Taken together, these findings have amply endorsed the efficacy of leptin therapy to restore glucose homeostasis in insulin-deficient as well as hyperinsulinemic diabetic patients. Consequently, restoration of optimal hypothalmic signaling to reinstate glucose homeostasis with leptin is a highly suitable new therapeutic strategy to ameliorate diabetes type 1 and 2 for the lifetime and to replace the currently in vogue insulin monotherapy. In view of the relentless challenges posed by the worldwide epidemic of diabetes and soaring treatment costs, taken together with the well-known shortcomings of therapies based on restoring insulin signaling, it is highly critical and timely to undertake new clinical trials that ascertain appropriate dosage and route of leptin delivery to the hypothalamus capable of safely sustaining stable glycemia for lifetime.

  10. Should leptin replace insulin as a lifetime monotherapy for diabetes type 1 and 2?

    Directory of Open Access Journals (Sweden)

    Satya P Kalra

    2013-01-01

    Full Text Available Evidence accumulated during the last decade has affirmed that adipocyte leptin insufficiency in the hypothalamus is the primary etiological factor in the pathogenesis of diabetes type 1 and 2 and related metabolic morbidities. Leptin insufficiency disrupts the relay of hypothalamic regulatory information along three descending pathways to the organs in the periphery that normally participate in maintenance of glucose homeostasis on a minute-to-minute basis throughout lifetime. Reinstatement of leptin sufficiency in the hypothalamus by either systemic or central injections, or its provision selectively in the hypothalamus with the aid of gene therapy extinguished hyperglycemia and normalized blood glucose stably during the entire course of treatment in a variety of animal models of diabetes type 1 and 2. In follow-up clinical trials, twice daily leptin treatment in leptinopenic and insulinopenic type 1 diabetics and leptinopenic and hyperinsulinemic type 2 diabetics with congenital lipodystrophy or acquired lipoatrophy normalized blood glucose without any discernible adverse effects during the extended course of treatment. Taken together, these findings have amply endorsed the efficacy of leptin therapy to restore glucose homeostasis in insulin-deficient as well as hyperinsulinemic diabetic patients. Consequently, restoration of optimal hypothalmic signaling to reinstate glucose homeostasis with leptin is a highly suitable new therapeutic strategy to ameliorate diabetes type 1 and 2 for the lifetime and to replace the currently in vogue insulin monotherapy. In view of the relentless challenges posed by the worldwide epidemic of diabetes and soaring treatment costs, taken together with the well-known shortcomings of therapies based on restoring insulin signaling, it is highly critical and timely to undertake new clinical trials that ascertain appropriate dosage and route of leptin delivery to the hypothalamus capable of safely sustaining stable

  11. Cellular dysfunction in the diabetic fibroblast: impairment in migration, vascular endothelial growth factor production, and response to hypoxia.

    Science.gov (United States)

    Lerman, Oren Z; Galiano, Robert D; Armour, Mary; Levine, Jamie P; Gurtner, Geoffrey C

    2003-01-01

    Although it is known that systemic diseases such as diabetes result in impaired wound healing, the mechanism for this impairment is not understood. Because fibroblasts are essential for wound repair, we compared the in vitro behavior of fibroblasts cultured from diabetic, leptin receptor-deficient (db/db) mice with wild-type fibroblasts from mice of the same genetic background in processes important during tissue repair. Adult diabetic mouse fibroblast migration exhibited a 75% reduction in migration compared to normal fibroblasts (P under basal or hypoxic conditions, confirming that the results from db/db fibroblasts in mature mice resulted from the diabetic state and were not because of alterations in the leptin-leptin receptor axis. Markers of cellular viability including proliferation and senescence were not significantly different between diabetic and wild-type fibroblasts. We conclude that, in vitro, diabetic fibroblasts show selective impairments in discrete cellular processes critical for tissue repair including cellular migration, VEGF production, and the response to hypoxia. The VEGF abnormalities developed concurrently with the onset of hyperglycemia and were not seen in normoglycemic, leptin receptor-deficient db/db mice. These observations support a role for fibroblast dysfunction in the impaired wound healing observed in human diabetics, and also suggest a mechanism for the poor clinical outcomes that occur after ischemic injury in diabetic patients.

  12. Multiple non-cell-autonomous defects underlie neocortical callosal dysgenesis in Nfib-deficient mice

    Directory of Open Access Journals (Sweden)

    Sunn Nana

    2009-12-01

    Full Text Available Abstract Background Agenesis of the corpus callosum is associated with many human developmental syndromes. Key mechanisms regulating callosal formation include the guidance of axons arising from pioneering neurons in the cingulate cortex and the development of cortical midline glial populations, but their molecular regulation remains poorly characterised. Recent data have shown that mice lacking the transcription factor Nfib exhibit callosal agenesis, yet neocortical callosal neurons express only low levels of Nfib. Therefore, we investigate here how Nfib functions to regulate non-cell-autonomous mechanisms of callosal formation. Results Our investigations confirmed a reduction in glial cells at the midline in Nfib-/- mice. To determine how this occurs, we examined radial progenitors at the cortical midline and found that they were specified correctly in Nfib mutant mice, but did not differentiate into mature glia. Cellular proliferation and apoptosis occurred normally at the midline of Nfib mutant mice, indicating that the decrease in midline glia observed was due to deficits in differentiation rather than proliferation or apoptosis. Next we investigated the development of callosal pioneering axons in Nfib-/- mice. Using retrograde tracer labelling, we found that Nfib is expressed in cingulate neurons and hence may regulate their development. In Nfib-/- mice, neuropilin 1-positive axons fail to cross the midline and expression of neuropilin 1 is diminished. Tract tracing and immunohistochemistry further revealed that, in late gestation, a minor population of neocortical axons does cross the midline in Nfib mutants on a C57Bl/6J background, forming a rudimentary corpus callosum. Finally, the development of other forebrain commissures in Nfib-deficient mice is also aberrant. Conclusion The formation of the corpus callosum is severely delayed in the absence of Nfib, despite Nfib not being highly expressed in neocortical callosal neurons. Our

  13. Leptin-induced endothelium-dependent vasorelaxation of peripheral arteries in lean and obese rats: role of nitric oxide and hydrogen sulfide.

    Directory of Open Access Journals (Sweden)

    Anna Jamroz-Wiśniewska

    Full Text Available Adipose tissue hormone leptin induces endothelium-dependent vasorelaxation mediated by nitric oxide (NO and endothelium-derived hyperpolarizing factors (EDHF. Previously it has been demonstrated that in short-term obesity the NO-dependent and the EDHF-dependent components of vascular effect of leptin are impaired and up-regulated, respectively. Herein we examined the mechanism of the EDHF-dependent vasodilatory effect of leptin and tested the hypothesis that alterations of acute vascular effects of leptin in obesity are accounted for by chronic hyperleptinemia. The study was performed in 5 groups of rats: (1 control, (2 treated with exogenous leptin for 1 week to induce hyperleptinemia, (3 obese, fed highly-palatable diet for 4 weeks, (4 obese treated with pegylated superactive rat leptin receptor antagonist (PEG-SRLA for 1 week, (5 fed standard chow and treated with PEG-SRLA. Acute effect of leptin on isometric tension of mesenteric artery segments was measured ex vivo. Leptin relaxed phenylephrine-preconstricted vascular segments in NO- and EDHF-dependent manner. The NO-dependent component was impaired and the EDHF-dependent component was increased in the leptin-treated and obese groups and in the latter group both these effects were abolished by PEG-SRLA. The EDHF-dependent vasodilatory effect of leptin was blocked by either the inhibitor of cystathionine γ-lyase, propargylglycine, or a hydrogen sulfide (H2S scavenger, bismuth (III subsalicylate. The results indicate that NO deficiency is compensated by the up-regulation of EDHF in obese rats and both effects are accounted for by chronic hyperleptinemia. The EDHF-dependent component of leptin-induced vasorelaxation is mediated, at least partially, by H2S.

  14. Interleukin-18 gene-deficient mice show enhanced defense and reduced inflammation during pneumococcal meningitis

    NARCIS (Netherlands)

    Zwijnenburg, Petra J. G.; van der Poll, Tom; Florquin, Sandrine; Akira, Shizuo; Takeda, Kiyoshi; Roord, John J.; van Furth, A. Marceline

    2003-01-01

    To determine the role of endogenous interleukin-18 (IL-18) in pneumococcal meningitis, meningitis was induced in IL-18 gene-deficient (IL-18(-/-)) and wild-type (WT) mice by intranasal inoculation of Streptococcus pneumoniae with hyaluronidase. Induction of meningitis resulted in an upregulation of

  15. Interleukin-18 gene-deficient mice show enhanced defense and reduced inflammation during pneumococcal meningitis.

    NARCIS (Netherlands)

    Zwijnenburg, P.J.G.; Poll, van der T.; Florquin, S; Akira, S; Takeda, K; Roord, J.J.; Furth, van A.M.

    2003-01-01

    To determine the role of endogenous interleukin-18 (IL-18) in pneumococcal meningitis, meningitis was induced in IL-18 gene-deficient (IL-18(-/-)) and wild-type (WT) mice by intranasal inoculation of Streptococcus pneumoniae with hyaluronidase. Induction of meningitis resulted in an upregulation of

  16. Induction of premalignant host responses by cathepsin x/z-deficiency in Helicobacter pylori-infected mice.

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    Sabine Krueger

    Full Text Available Helicobacter pylori are responsible for the induction of chronic gastric inflammation progressing to atrophy, metaplasia, and gastric cancer. The overexpression of Cathepsin X/Z (Ctsz in H. pylori-infected mucosa and gastric cancer is mediated predominantly by an augmented migration of ctsz(-/-positive macrophages and the up-regulation of Ctsz in tumor epithelium. To explore the Ctsz-function in the context of chronic inflammation and the development of preneoplastic lesions, we used Ctsz-deficient mice in a H. pylori gastritis model. Ctsz (-/- and wild-type (wt mice were infected with H. pylori strain SS1. The mice were sacrificed at 24, 36, and 50 weeks post infection (wpi. The stomach was removed, and gastric strips were snap-frozen or embedded and stained with H&E. Tissue sections were scored for epithelial lesions and inflammation. Ki-67 and F4/80 immunostaining were used to measure epithelial cell proliferation and macrophage infiltration, respectively. The upregulation of compensating cathepsins and cytokines were confirmed by Western blotting and quantitative RT-PCR. SS1-infected wt and ctsz (-/- mice showed strong inflammation, foveolar hyperplasia, atrophy, and cystically-dilated glands. However, at 50 wpi, ctsz (-/- mice developed significantly more severe spasmolytic polypeptide-expressing metaplasia (SPEM, showed enhanced epithelial proliferation, and higher levels of infiltrating macrophages. Induction of cytokines was higher and significantly prolonged in ctsz (-/- mice compared to wt. Ctsz deficiency supports H. pylori-dependent development of chronic gastritis up to metaplasia, indicating a protective, but not proteolytic, function of Ctsz in inflammatory gastric disease.

  17. mTOR (Mechanistic Target of Rapamycin) Inhibition Decreases Mechanosignaling, Collagen Accumulation, and Stiffening of the Thoracic Aorta in Elastin-Deficient Mice.

    Science.gov (United States)

    Jiao, Yang; Li, Guangxin; Li, Qingle; Ali, Rahmat; Qin, Lingfeng; Li, Wei; Qyang, Yibing; Greif, Daniel M; Geirsson, Arnar; Humphrey, Jay D; Tellides, George

    2017-09-01

    Elastin deficiency because of heterozygous loss of an ELN allele in Williams syndrome causes obstructive aortopathy characterized by medial thickening and fibrosis and consequent aortic stiffening. Previous work in Eln -null mice with a severe arterial phenotype showed that inhibition of mTOR (mechanistic target of rapamycin), a key regulator of cell growth, lessened the aortic obstruction but did not prevent early postnatal death. We investigated the effects of mTOR inhibition in Eln -null mice partially rescued by human ELN that manifest a less severe arterial phenotype and survive long term. Thoracic aortas of neonatal and juvenile mice with graded elastin deficiency exhibited increased signaling through both mTOR complex 1 and 2. Despite lower predicted wall stress, there was increased phosphorylation of focal adhesion kinase, suggestive of greater integrin activation, and increased transforming growth factor-β-signaling mediators, associated with increased collagen expression. Pharmacological blockade of mTOR by rapalogs did not improve luminal stenosis but reduced mechanosignaling (in delayed fashion after mTOR complex 1 inhibition), medial collagen accumulation, and stiffening of the aorta. Rapalog administration also retarded somatic growth, however, and precipitated neonatal deaths. Complementary, less-toxic strategies to inhibit mTOR via altered growth factor and nutrient responses were not effective. In addition to previously demonstrated therapeutic benefits of rapalogs decreasing smooth muscle cell proliferation in the absence of elastin, we find that rapalogs also prevent aortic fibrosis and stiffening attributable to partial elastin deficiency. Our findings suggest that mTOR-sensitive perturbation of smooth muscle cell mechanosensing contributes to elastin aortopathy. © 2017 American Heart Association, Inc.

  18. Parasitic infection improves survival from septic peritonitis by enhancing mast cell responses to bacteria in mice.

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    Rachel E Sutherland

    Full Text Available Mammals are serially infected with a variety of microorganisms, including bacteria and parasites. Each infection reprograms the immune system's responses to re-exposure and potentially alters responses to first-time infection by different microorganisms. To examine whether infection with a metazoan parasite modulates host responses to subsequent bacterial infection, mice were infected with the hookworm-like intestinal nematode Nippostrongylus brasiliensis, followed in 2-4 weeks by peritoneal injection of the pathogenic bacterium Klebsiella pneumoniae. Survival from Klebsiella peritonitis two weeks after parasite infection was better in Nippostrongylus-infected animals than in unparasitized mice, with Nippostrongylus-infected mice having fewer peritoneal bacteria, more neutrophils, and higher levels of protective interleukin 6. The improved survival of Nippostrongylus-infected mice depends on IL-4 because the survival benefit is lost in mice lacking IL-4. Because mast cells protect mice from Klebsiella peritonitis, we examined responses in mast cell-deficient Kit(W-sh/Kit(W-sh mice, in which parasitosis failed to improve survival from Klebsiella peritonitis. However, adoptive transfer of cultured mast cells to Kit(W-sh/Kit(W-sh mice restored survival benefits of parasitosis. These results show that recent infection with Nippostrongylus brasiliensis protects mice from Klebsiella peritonitis by modulating mast cell contributions to host defense, and suggest more generally that parasitosis can yield survival advantages to a bacterially infected host.

  19. Rearrangement of RAG-1 recombinase gene in DNA-repair deficient ``wasted`` mice

    Energy Technology Data Exchange (ETDEWEB)

    Woloschak, G.E.; Libertin, C.R.; Weaver, P. [Loyola Univ., Chicago, IL (United States); Churchill, M.; Chang-Liu, C.M. [Argonne National Lab., IL (United States)

    1993-11-01

    Mice recessive for the autosomal gene ``wasted`` wst display a disease pattern which includes increased sensitivity to the killing effects of ionizing radiation, immunodeficiency, and neurologic dysfunction. The recent cloning and characterization of recombinase genes (RAG-l/RAG-2) expressed in lymphoid and possibly central nervous system tissues prompted us to examine expression of these genes in DNA repair-deficient/immunodeficient wasted mice. Our results revealed expression of RAG-1 mRNA in spinal cord (but not brain) of control mice; no expression of RAG-1 mRNA was detected in spinal cord or brain from wst/wst mice or their normal littermates (wst/{center_dot}mice). In thymus tissue, a small RAG-1 transcript (1.0 kb) was detected in wst/wst mice that was not evident in thymus from control mice. In wst/{center_dot}mice, a two-fold increase in RAG-1 mRNA was evident in thymus tissue. RAG-2 mRNA could only be detected in thymus tissue from wst/{center_dot} and not from wst/wst or parental control BCF{sub 1} mice. Southern blots revealed a rearrangement/deletion within the RAG-1 gene of affected wasted mice, not evident in known strain-specific parental or littermate controls. These results support the idea that the RAG-1 gene may map at or near the locus for the wasted mutation. In addition, they suggest the importance of recombinase function in normal immune and central nervous system development as well as the potential contribution of this gene family to the normal repair of radiation-induced DNA damage.

  20. Increased Plasmodium chabaudi malaria mortality in mice with nutritional iron deficiency can be reduced by short-term adjunctive iron supplementation

    DEFF Research Database (Denmark)

    Castberg, Filip C; Maretty, Lasse; Staalsoe, Trine

    2018-01-01

    infected mice had extramedullary splenic haematopoiesis, and iron-supplemented mice had visually detectable intracellular iron stores. CONCLUSIONS: Blood transfusions are the only currently available means to correct severe anaemia in children with malaria. The potential of carefully timed, short...... parts of the world. This has rendered interventions against iron deficiency in malaria-endemic areas controversial. METHODS: The effect of nutritional iron deficiency on the clinical outcome of Plasmodium chabaudi AS infection in A/J mice and the impact of intravenous iron supplementation with ferric...... deficiency was associated with increased mortality from P. chabaudi malaria. This increased mortality could be partially offset by carefully timed, short-duration adjunctive iron supplementation. Moribund animals were characterized by low levels of hepcidin and high levels of fibroblast growth factor 23. All...