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Sample records for leptin obesity protein

  1. Leptin, obesity and cardiovascular disease.

    Science.gov (United States)

    Correia, Marcelo Lima de Gusmao; Haynes, William Geoffrey

    2004-03-01

    Obesity is a risk factor for cardiovascular diseases. Leptin levels are increased in obesity and leptin exhibits cardiovascular actions that may contribute to increased cardiovascular risk. We review the sympathetic, renal and vascular actions of leptin and their relevance to cardiovascular disease. Leptin possesses cardio-renal actions potentially contributing to obesity-related hypertension including generalized sympathoactivation. However, given that leptin resistance occurs in obesity, it has been difficult to link hyperleptinemia with hypertension. One possibility is that leptin resistance is confined to the metabolic effects of leptin, with preservation of its sympathoexcitatory actions. Other mechanisms may contribute to the pressor effects of leptin. For instance, angiotensin II induces leptin generation. Leptin also potentiates the pressor effect of insulin. Therefore, interactions between angiotensin II and insulin with leptin could have deleterious cardiovascular effects in obesity. Additionally, leptin appears to stimulate vascular inflammation, oxidative stress and hypertophy. These actions may contribute to the pathogenesis of hypertension, atherosclerosis, and left ventricular hypertrophy. The potential actions of leptin in the pathophysiology of cardiovascular complications of obesity are diverse, despite evidence of leptin resistance to its metabolic actions. However, most information about cardiovascular actions of leptin derives from in-vitro and animal studies. Future research in humans is widely awaited.

  2. 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.

  3. Pro-inflammatory triggers in childhood obesity: correlation between leptin, adiponectin and high-sensitivity C-reactive protein in a group of obese Portuguese children.

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    Pires, António; Martins, Paula; Pereira, Ana Margarida; Marinho, Joana; Vaz Silva, Patrícia; Marques, Margarida; Castela, Eduardo; Sena, Cristina; Seiça, Raquel

    2014-11-01

    Pediatric obesity is increasingly prevalent in the Portuguese population. Adipocyte dysfunction results in the expression of pro-inflammatory mediators that are responsible for the low-grade inflammatory process that characterizes obesity. The aim of this study was to investigate the relationship between markers of adiposity, inflammation and adipokines in a Portuguese obese pediatric population. One hundred and twenty children of both sexes, aged 6-17 years, were included in this study. The control group consisted of 41 healthy normal-weight children. The variables analyzed were age, gender, body mass index, waist circumference, fat mass percentage, high-sensitivity C-reactive protein (hs-CRP), leptin and adiponectin. There were significant differences between controls and obese children for all parameters analyzed. In the obese group, after controlling for age and gender, hs-CRP (p=0.041), adiponectin (p=0.019) and leptin (p<0.001) still showed significant statistical differences. A direct correlation was found between hs-CRP, leptin, body mass index and waist circumference, the strongest being with leptin (r=0.568; p<0.001). This trend remained statistically significant, regardless of gender or pubertal age. Considering the role of leptin, adiponectin and hs-CRP in the genesis of endothelial dysfunction, they may be used in clinical practice for risk stratification, as well as in the assessment of weight control programs. Copyright © 2014 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  4. Serum leptin and insulin tests in obesity

    International Nuclear Information System (INIS)

    Yang Yin; Jiang Xiaojin; Leng Xiumei

    2001-01-01

    Objective: To study the clinical significance and the relations of leptin and insulin on obesity group. Methods: Leptin and insulin were tested with radioimmunoassay (RIA) in pre-obesity group and obesity group respectively. Results: Serum leptin and insulin levels were significantly elevated in obesity group compare with the controls (P<0.01). Conclusion: Changing with insulin, the elevation of leptin in obesity group has been identified as an important agent of diabetes mellitus (DM)

  5. Effects of 2 G on adiposity, leptin, lipoprotein lipase, and uncoupling protein-1 in lean and obese Zucker rats

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    Warren, L. E.; Horwitz, B. A.; Hamilton, J. S.; Fuller, C. A.

    2001-01-01

    Male Zucker rats were exposed to 2 G for 8 wk to test the hypothesis that the leptin regulatory pathway contributes to recovery from effects of 2 G on feeding, growth, and nutrient partitioning. After initial hypophagia, body mass-independent food intake of the lean rats exposed to 2 G surpassed that of the lean rats maintained at 1 G, but food intake of the obese rats exposed to 2 G remained low. After 8 wk at 2 G, body mass and carcass fat were less in both genotypes. Leptin and percent fat were lower in lean rats exposed to 2 G vs. 1 G but did not differ in obese rats exposed to 2 G vs. 1 G. Although exposure to 2 G did not alter uncoupling protein-1 levels, it did elicit white fat pad-specific changes in lipoprotein lipase activity in obese but not lean rats. We conclude that 2 G affects both genotypes but that the lean Zucker rats recover their food intake and growth rate and retain "normal" lipoprotein lipase activity to a greater degree than do the obese rats, emphasizing the importance of a functional leptin regulatory pathway in this acclimation.

  6. Response of Leptin and C-reactive Protein Serum Levels to 12 Weeks Moderate Intensity Aerobic Exercise in Obese Men

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    Sonia Ghiasi

    2017-01-01

    Full Text Available The aim of this study was to investigate the effect of 12 weeks moderate intensity aerobic exercise on leptin and C-reactive protein serum levels in obese men. The study was conducted in Urmia- Iran in 2015. Twenty-four obese men with an aged range 40-50 yrs. were enrolled into the study. Subjects were randomized to one of 2 groups exercise (n=12 and control groups (n=12. The exercise group performed aerobic exercise training up to 50-70 % heart rate reserve, three times a week for 12 weeks. Leptin and CRP serum level was measured by ELISA method before and after the 12 weeks. After 12 weeks exercise training, leptin and CRP serum level in the exercise group compared to the control group, were decreased significantly (P<0.05. To sum up, 12 weeks moderate intensity aerobic exercise in the reduction of CRP and leptin concentration had a prominent role that might be effective in reducing weight and improving cardiovascular risk factors.

  7. [Leptin].

    Science.gov (United States)

    Nedvídková, J

    1997-12-01

    Leptin (ob-protein), a previously unknown protein signal, is secreted from adipose tissue, circulates in the blood, probably bound to a family of binding proteins, and acts on central neural networks, that regulate weight and energy homeostasis. Leptin provides a communication link between fat tissue and the brain. Ob protein appears to play a major role in the control of body fat stores through coordinated regulation of feeding behavior, metabolism, autonomic nervous system and body energy balance in rodents, primates and humans. Leptin levels have pulsative and diurnal character. In lean subjects with relatively low adipose tissue, the majority of circulating leptin is in the bound form. On other hand, in obese individuals the majority of leptin circulates in free form presumably bioactive protein, and thus obese subjects are resistant to free leptin. Leptin's resistance is often coupled with insuline resistance postreceptor type. Leptin receptor is product of db genes. Ob-protein receptor belongs to the cytokine superfamily of receptors and has several variants. Leptin-receptor gene is expressed in abundant degree in ovary, uterus, testes, less in hypothalamus, hypophysis, and little in kidney. Leptin stimulates the reproductive endocrine system and may serve as a permissive signal to the reproductive system of normal animals. Ob-gene product, leptin is regulated by feedings patterns and hormones, such as insulin and glucocorticoids. There is assumed that neuropeptide Y (NPY) and melanocyte-stimulating hormone (MSH) and its receptor (MCR) are a critical components of the biological response to leptin levels. MCR in contrast to leptin receptors are coupled with G-transduction system.

  8. 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

  9. Kadar leptin saliva dan kejadian karies gigi anak obesitas (Salivary leptin levels and caries incidence in obese children

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    Elfrida Atzmaryanni

    2013-09-01

    Full Text Available Background: Children with obesity have a lower incidence of caries. Salivary leptin levels of obese children is higher than normal children. Leptin is protein hormone, contained in saliva. Salivary proteins maintain the balance of the ecosystem in the mouth. Purpose: The article was aimed to study the correlation of salivary leptin levels with caries incidence in obese children. Review: Mouth is reflection of the health status and so many changes occur as a weight gain. Child with obesity has a low incidence of caries than normal. This condition is associated with changes in oral cavity, especially the increase in salivary leptin. Caries is a disease of hard tissues cause by the activty of microorganisms, especially Streptococcus mutans. Salivary proteins maintain the balance of the ecosystem in the mouth. Leptin is a protein saliva, produced predominantly in adipose tissue and conduct active transport to saliva. Salivary leptin works in two ways: as an antimicrobial which prevents the attachment of bacteria on tooth surface or by inducing cytokine that affect the immune system in oral cavity. Conclusion: Salivary leptin is higher in obese children than in normal children. The low incidence of caries on obesity is associated with salivary leptin. Alteration in salivary composition and flow rate also decreased caries in obesity.Latar belakang: Anak yang mengalami obesitas memiliki insiden karies yang rendah. Kadar leptin saliva anak obesitas lebih tinggi dari anak normal. Leptin merupakan salah satu protein hormon yang terdapat di saliva. Protein saliva berfungsi untuk menjaga keseimbangan ekosistem di mulut. Tujuan: Artikel ini bertujuan mempelajari hubungan antara kadar leptin di dalam saliva dengan kejadian karies anak obesitas. Tinjauan pustaka: Rongga mulut merupakan cerminan dari status kesehatan dan banyak perubahan yang terjadi seiring peningkatan berat badan seseorang. Anak Obesitas memiliki insiden karies yang rendah jika dibandingkan

  10. Diet-induced obese mice retain endogenous leptin action.

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    Ottaway, Nickki; Mahbod, Parinaz; Rivero, Belen; Norman, Lee Ann; Gertler, Arieh; D'Alessio, David A; Perez-Tilve, Diego

    2015-06-02

    Obesity is characterized by hyperleptinemia and decreased response to exogenous leptin. This has been widely attributed to the development of leptin resistance, a state of impaired leptin signaling proposed to contribute to the development and persistence of obesity. To directly determine endogenous leptin activity in obesity, we treated lean and obese mice with a leptin receptor antagonist. The antagonist increased feeding and body weight (BW) in lean mice, but not in obese models of leptin, leptin receptor, or melanocortin-4 receptor deficiency. In contrast, the antagonist increased feeding and BW comparably in lean and diet-induced obese (DIO) mice, an increase associated with decreased hypothalamic expression of Socs3, a primary target of leptin. These findings demonstrate that hyperleptinemic DIO mice retain leptin suppression of feeding comparable to lean mice and counter the view that resistance to endogenous leptin contributes to the persistence of DIO in mice. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Analysis of the relationship of leptin, high-sensitivity C-reactive protein, adiponectin, insulin, and uric acid to metabolic syndrome in lean, overweight, and obese young females.

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    Abdullah, Abdul Ridha; Hasan, Haydar A; Raigangar, Veena L

    2009-02-01

    Over the last decade there has been a steady rise in obesity and co-morbidity, but little is known about the rate of metabolic dysfunction among young adults in the United Arab Emirates. Various factors have been implicated as biomarkers of metabolic syndrome. The objective of this study was to analyze the relationships of leptin, C-reactive protein (CRP), adiponectin, insulin, and uric acid to the metabolic syndrome components in lean, overweight, and obese young females. This was a cross-sectional study of 69 apparently healthy young females, who were classified according to their body mass index (BMI) (kg/m(2)) into three groups: lean (25 and or=30). Estimated biomarkers were: leptin, insulin, adiponectin, high-sensitivity [hs]-CRP, uric acid, blood sugar, high-density lipoprotein (HDL), low-density lipoprotein (LDL), total cholesterol, and triglycerides (TG). Anthropometric measures, blood pressure, and homeostasis model assessment-insulin resistance (HOMA-IR) were also measured. Serum leptin, hs-CRP, insulin, and uric acid increased significantly (p metabolic syndrome components was found in lean subjects (leptin vs. waist circumference r = 0.48) as opposed to six in the obese group (hs-CRP vs. waist circumference and systolic blood pressure [SBP], r = 0.45 and r = -0.41, respectively; insulin vs. diastolic blood pressure [DBP], r = 0.47; adiponectin vs. blood sugar, r = -0.44; and uric acid vs. waist circumference and TG, r = 0.5 and r = 0.51, respectively). Estimation of the levels of studied biomarkers could be an important tool for early detection of metabolic syndrome before the appearance of its frank components. Uric acid seems to be the most reliable biomarker to identify obese subjects with metabolic syndrome.

  12. Obesity-Related Hypertension: Focus on Leptin

    DEFF Research Database (Denmark)

    Asferg, Camilla Lundegaard

    Background: Hypertension is a leading cause of death worldwide. Population studies have shown that at least two-thirds of hypertension incidence can be attributed directly to overweight and obesity. The underlying mechanisms linking obesity to hypertension are not clear. Various factors have been...... suggested to play a role in obesity-related hypertension such as the renin-angiotensin-aldosterone system, the sympathetic nervous system, inflammation, insulin resistance, physical inactivity, and abnormal production of adipocytokines. Of all adipocytokines, leptin and adiponectin have received most...... attention and both hormones are considered as candidate intermediaries between adipose tissue and overweight and obesity-related disorders. Objectives: To study obesity-related hypertension with special focus on the hormone leptin. As obesity-related hypertension is multifactorial, other biological systems...

  13. Protein quantitative trait locus study in obesity during weight-loss identifies a leptin regulator

    DEFF Research Database (Denmark)

    Carayol, Jérôme; Chabert, Christian; Di Cara, Alessandro

    2017-01-01

    Thousands of genetic variants have been associated with complex traits through genomewide association studies. However, the functional variants or mechanistic consequences remain elusive. Intermediate traits such as gene expression or protein levels are good proxies of the metabolic state of an o...

  14. 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

  15. Leptin Resistance: A Possible Interface Between Obesity and Pulmonary-Related Disorders.

    Science.gov (United States)

    Rehman Khan, Abdul; Awan, Fazli Rabbi

    2016-01-01

    Under normal physiological conditions, leptin regulates body weight by creating a balance between food intake and energy expenditure. However, in obesity, serum leptin levels increase and become defective to retain energy balance. Elevated serum leptin levels are regarded as an established marker of obesity. It is also reported that obese asthmatic patients have maximum serum leptin levels compared to other groups such as non-obese asthmatics, and normal obese and non obese subjects without asthma. In addition to having an appetite suppressing effect, leptin also regulates certain acute-phase protein expressions including α-1 antitrypsin (A1AT) in the liver. A1AT is a protease inhibitor that counterbalances the activity of the neutrophil elastase (NE) enzyme. A1AT reductions in obese-leptin resistant subjects lead to increased NE activity. The overactivity of NE degrades lung tissue proteins, which may lead to pulmonary disorders including asthma. On the basis of prior studies, it could be hypothesized that, in obese asthmatic patients, the highest degree of leptin failure/resistance might lead to the creation of an imbalance between NE and its inhibitor A1AT. To ascertain this, large scale prospective studies are warranted to assess the comparative serum leptin and A1AT levels and NE activity in asthmatic non-obese and obese patients, simultaneously. Such studies might help to devise novel interventional therapies for the treatment of pulmonary-related problems including asthma, chronic obstructive pulmonary disorder (COPD), and other lung defects in susceptible obese subjects in the future.

  16. Leptin, Adiponectin, and Obesity among Caucasian and Asian Women

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    Shannon M. Conroy

    2011-01-01

    Full Text Available Ethnic differences in adipose tissue distribution may contribute to different chronic disease risks across ethnic groups, and adipokines may mediate the risk. In a cross-sectional study, we examined ethnic differences in adipokines and inflammatory markers as related to body mass index (BMI among 183 premenopausal women with Caucasian and Asian ancestry. General linear models were used to estimate adjusted mean levels of leptin, adiponectin, interleukin-6, and C-reactive protein (CRP. Asian women had significantly lower serum levels of leptin, adiponectin, and CRP than Caucasian participants (P≤.01 across all levels of BMI. Among overweight and obese women, Asians showed a stronger association of CRP with leptin (β=1.34 versus β=0.64 and with adiponectin (β=−0.95 versus β=−0.75 than Caucasians. Compared to Caucasians of similar BMI, Asians may experience a higher chronic disease risk due to lower levels of adiponectin despite their lower levels of leptin.

  17. Relation between obesity, lipid profile, leptin and atopic disorders in ...

    African Journals Online (AJOL)

    Background: Obesity has become a disease of great importance affecting children and adolescents. Obesity can cause atopy or inflammation, where there are some common factors that predispose to both obesity and atopy. Objective: To study the factors contributing to allergic disorders in obese children, the role of leptin ...

  18. Leptin receptor in peripheral adipose tissues of obese subjects

    International Nuclear Information System (INIS)

    Du Tongxin; Sun Junjiang; Wang Zizheng; Wang Shukui; Fu Lei; Han Liu

    2002-01-01

    Objective: To investigate the relationship between leptin receptor and obesity by studying the leptin receptor density B max and dissociation constant K d in peripheral adipose tissue in subjects with different body weight mass (BMI). Methods: Leptin receptor density B max and K d were assayed via radioligand method in 71 cases, including 32 classified as obese, 19 over-weight and 20 normal control. Results: With the escalating of BMI, the leptin receptor density significantly decreased in obese and over-weight group compared with that in normal control (both P d values were of no differences among all three groups suggesting no correlation between the binding ability of leptin to its receptor and BMI. A negative correlation between BMI and B max (r=-0.76, P<0.01) displayed after all. Conclusion: Leptin receptor density correlates with the BMI in obese cases and it suggests that the down-regulation of leptin receptor may contribute to the occurrence of leptin resistance and obesity after-wards

  19. Teasaponin improves leptin sensitivity in the prefrontal cortex of obese mice.

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    Yu, Yinghua; Wu, Yizhen; Szabo, Alexander; Wang, Sen; Yu, Shijia; Wang, Qing; Huang, Xu-Feng

    2015-12-01

    Obesity impairs cognition, and the leptin-induced increase of brain-derived neurotrophic factor (BDNF) and neurogenesis. Tea consumption improves cognition and increases brain activation in the prefrontal cortex. This study examined whether teasaponin, an active ingredient in tea, could improve memory and central leptin effects on neurogenesis in the prefrontal cortex of obese mice, and in vitro in cultured prefrontal cortical neurons. Teasaponin (10 mg/kg, intraperitoneal) for 21 days improved downstream leptin signaling (JAK2 and STAT3), and leptin's effect on BDNF, in the prefrontal cortex of high-fat diet (HFD) fed mice. Prefrontal cortical neurons were cultured with teasaponin and palmitic acid (the most abundant dietary saturated fatty acid) to examine their effects on neurogenesis and BDNF expression in response to leptin. Palmitic acid decreased leptin's effect on neurite outgrowth, postsynaptic density protein 95, and BDNF expression in cultured cortical neurons, which was reversed by teasaponin. Teasaponin improved the leptin sensitivity of prefrontal cortical neurons in obese mice or when treated by palmitic acid. This in turn increased BDNF expression and neurite growth. Therefore, teasaponin supplementation may be used to prevent obesity-associated neurodegeneration and improve cognitive function. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Obesity, diabetes and leptin: lessons learned from obese hyperglycemic mice

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    Meftun Ahmed

    2008-07-01

    Full Text Available The recent epidemic nature of obesity and association of obesity with the development of type 2 diabetes demands dissection of the pathophysiology of this morbid disorder which is essential for better understanding of the process of evolution of insulin resistance. Different animal models have been used to explore the mechanism linking obesity to insulin resistance and type 2 diabetes. The discovery of ob gene and its product, leptin, has revealed the signaling system regulating energy balance in rodents. The mice lacking this ob gene, ob/ob mice, display obesity, hyperglycemia and hyperinsulinemia and has been extensively used for the study of type 2 diabetes and for potential drug development. In this review, the features and development of obese hyperglycemic syndrome, the role of leptin in the pathogenesis of the syndrome and finally the applicability of the findings in rodents to body weight regulation and pathogenesis of insulin resistance in humans have been summarized. Ibrahim Med. Coll. J. 2008; 2(2: 72-84

  1. Comparison of leptin protein levels in Prader-Willi syndrome and control individuals.

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    Butler, M G; Moore, J; Morawiecki, A; Nicolson, M

    1998-01-06

    Prader-Willi syndrome (PWS) is characterized by early childhood obesity, mental deficiency, hypogonadism, hypotonia, hypopigmentation, short stature, small hands and feet, and a characteristic face. It is the most common genetic cause of obesity and obesity is the most significant health problem for PWS patients. Ob protein (leptin), which is produced by adipose tissue, is thought to play a significant role in obesity; thus, unusually low plasma leptin levels, or relative loss of sensitivity to leptin in PWS subjects, could be an important factor in their obesity. We measured plasma leptin levels in 19 obese and 14 non-obese PWS patients [mean body mass index (BMI) 37.2 and 22.0, respectively] and compared these levels to those of 28 obese controls (mean BMI 35.5) and 16 non-obese control individuals (mean BMI 21.6). The mean plasma leptin concentration (ng/ml) for obese PWS subjects was 33.4 and 23.6 for non-obese PWS subjects. Obese control leptin was 36.2 ng/ml and non-obese control was 9.9. Among the control groups, leptin levels in females were significantly higher than those in males; the obese males and females had significantly higher leptin than their respective non-obese counterparts. These differences did not hold true for the PWS subjects. Leptin levels in obese PWS males and females were similar, and the same was true of the non-obese PWS males and females. The differences between obese and non-obese PWS subjects of both sexes were small and not significant. Comparing control groups with their PWS counterparts revealed no significant differences, with one exception: circulating plasma leptin levels in non-obese PWS males were nearly five times higher than in non-obese control males with similar BMI. This difference may reflect a more female pattern of fat distribution and hypogonadism, which are characteristic of PWS males. Leptin levels in PWS patients were not obviously correlated with the chromosome 15 finding seen in the patients.

  2. [Obesity and leptin association in three Chilean aboriginal populations].

    Science.gov (United States)

    Pérez, F; Santos, J L; Albala, C; Calvillán, M; Carrasco, E

    2000-01-01

    Although there is a clear relationship between body mass index and leptin levels, few authors have addressed the possible influence of ethnic factors on these levels. To measure serum leptin in three different Chilean aboriginal populations. Fasting serum leptin and insulin levels were measured by radioimmunoassay in 345 rural mapuche individuals, 247 rural aymara subjects and 162 urban mapuche subjects. A body mass index of 27.5 kg/m2 was used as cutoff point to classify study subjects. Among the three ethnic groups, women had serum leptin levels three times higher than men. In all three ethnic groups, there was a significant association between leptin levels, body mass index and gender (r2 = 0.32 and 0.5 p mapuche, r2 = 0.32 and 0.5 p mapuche populations). No differences in leptin levels were observed for the interaction between age and insulin. The increments per quartile in leptin levels were lower among mapuche than aymara individuals. Rural mapuche individuals have a high frequency of obesity. However their leptin levels are lower than those of aymara or urban mapuche populations. The higher leptin levels observed in urban mapuche subjects could be due to environmental influences.

  3. Analysis of changes of serum leptin, C-peptide levels and peripheral fat tissue leptin receptor expression in obesity

    International Nuclear Information System (INIS)

    Du Tongxin; Sun Junjiang; Wang Shukui; Fu Lei

    2002-01-01

    Objective: To explore the mechanism of obesity and obesity accompanied type two diabetes mellitus by investigating changes of serum leptin, C-peptide (C-P) levels and leptin receptor expression in peripheral adipose tissues. Methods: Peripheral leptin receptor density was measured via radio-ligand binding method, serum leptin and C - P levels were measured via radioimmunoassay in 91 cases (38 in obesity group, 23 in over weight, and 30 in normal controls). Results: With the increase of body mass index (BMI), the peripheral leptin receptor density of the over weight and obese cases decreased and was mash less than that of normal cases (both p<0.01, respectively). There was no statistical differences for Kd value among the three groups, suggesting no associated change between the binding ability of leptin receptor to its ligand. There was a negative correlation between BMI and leptin receptor density (r = -0.70, p < 0.01). The serum leptin and C-P levels in weight excess and obese subjects with type two DM were both increased, but significantly higher in obese group than those in weight excess group (p < 0.01). The increase of C-P was much marked than that of leptin. Serum C-P level was positively correlated with BMI. Conclusion: Changes of serum leptin, C-P levels and peripheral leptin receptor expression in cases with simple obesity and obesity accompanied with type two DM were related closely with BMI. Type 2 DM in obese subjects was related with leptin resistance and insulin resistance

  4. Reduction of obesity, as induced by leptin, reverses endothelial dysfunction in obese (Lep(ob)) mice

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    Winters, B.; Mo, Z.; Brooks-Asplund, E.; Kim, S.; Shoukas, A.; Li, D.; Nyhan, D.; Berkowitz, D. E.

    2000-01-01

    Obesity is a major health care problem and is associated with significant cardiovascular morbidity. Leptin, a neuroendocrine hormone released by adipose tissue, is important in modulating obesity by signaling satiety and increasing metabolism. Moreover, leptin receptors are expressed on vascular endothelial cells (ECs) and mediate angiogenesis. We hypothesized that leptin may also play an important role in vasoregulation. We investigated vasoregulatory mechanisms in the leptin-deficient obese (ob/ob) mouse model and determined the influence of leptin replacement on endothelial-dependent vasorelaxant responses. The direct effect of leptin on EC nitric oxide (NO) production was also tested by using 4, 5-diaminofluorescein-2 diacetate staining and measurement of nitrate and nitrite concentrations. Vasoconstrictor responses to phenylephrine, norepinephrine, and U-46619 were markedly enhanced in aortic rings from ob/ob mice and were modulated by NO synthase inhibition. Vasorelaxant responses to ACh were markedly attenuated in mesenteric microvessels from ob/ob mice. Leptin replacement resulted in significant weight loss and reversal of the impaired endothelial-dependent vasorelaxant responses observed in ob/ob mice. Preincubation of ECs with leptin enhanced the release of NO production. Thus leptin-deficient ob/ob mice demonstrate marked abnormalities in vasoregulation, including impaired endothelial-dependent vasodilation, which is reversed by leptin replacement. These findings may be partially explained by the direct effect of leptin on endothelial NO production. These vascular abnormalities are similar to those observed in obese, diabetic, leptin-resistant humans. The ob/ob mouse may, therefore, be an excellent new model for the study of the cardiovascular effects of obesity.

  5. Relationship of obesity with serum concentrations of leptin, CRP and IL-6 in breast cancer survivors

    International Nuclear Information System (INIS)

    Babaei, Z; Mosapour, A.; Moslemi, D.; Parsian, H.; Pouramir, M.; Khafri, S.

    2015-01-01

    Introduction: Several mechanisms have been proposed to explain the adverse effect of obesity on quality of life among women with breast cancer, including alteration in some inflammatory markers. The aim of this study was to determine the status of serum levels of leptin, IL-6 and CRP in obese, overweight and normal weight breast cancer survivors in order to determine the relationship between inflammatory markers’ levels and obesity. Materials and methods: This cross-sectional study was done on 75 women with breast cancer, 30 obese, 15 overweight and 30 normal weight patients. Serum leptin, IL-6, CRP, total protein, albumin and lipid profile as well as anthropometric parameters were measured in three groups. Results: Serum leptin levels of obese patients were significantly higher than those of overweight and normal weight patients ( P < 0.05). Higher serum CRP and lower albumin levels were observed in obese patients in comparison with normal weight patients ( P < 0.05). HDL-C level was significantly different between overweight and normal weight patients ( P < 0.05). Significant differences in serum IL-6 levels were not observed between the study groups ( P > 0.05). Moreover, multiple regression analysis showed that leptin was significantly associated with BMI ( P < 0.001), while albumin was negatively correlated with BMI ( P < 0.05). CRP levels were significantly correlated with BMI and waist-to-hip ratio (WHR) ( P < 0.05). Conclusions: In conclusion, high leptin levels and alteration in acute phase proteins in obese patients may exaggerate the inflammation status. As inflammation has the potential to increase the susceptibility of the patients to metastasis development, it is necessary to decline its rate.

  6. Obesity, Serum Resistin and Leptin Levels Linked to Coronary Artery Disease

    Directory of Open Access Journals (Sweden)

    Farzaneh Montazerifar

    Full Text Available Abstract Background: Clinical studies have demonstrated that adipocytokines play an important role in developing atherosclerotic cardiovascular diseases. Objective: The aim of study was to evaluate the relationship between serum resistin and leptin levels with obesity and coronary artery disease (CAD. Methods: In a cross-sectional study, we assessed the levels of serum resistin and leptin, C-reactive protein (CRP, lipid profile and cardiac enzyme tests (AST, CPK, LDH, CK-MB in 40 CAD patients compared to 40 healthy controls. Anthropometric measurements including weight and height for calculating of body mass index (BMI, and waist circumference (WC were performed for evaluation of obesity. Results: CAD patients had increased levels of leptin and CRP, (p < 0.001, cholesterol (p < 0.05, triglyceride (p < 0.01, and WC (p < 0.05 compared to healthy controls. There was no statistical difference between CAD and control subjects for resistin (p = 0.058. In a multiple regression analysis, only an association between serum leptin with BMI (β = 0.480, p < 0.05 and WC (β = 1.386, p < 0.05 was found. Conclusions: The findings suggest that leptin is a better marker of fat mass value than resistin and may be considered an independent risk factor for cardiac disorders that is largely dependent on obesity. However, further prospective studies are needed to confirm these results.

  7. Changes of serum leptin and other related hormones levels in simple obese children

    International Nuclear Information System (INIS)

    Xiao Jinhua; Wang Yaping; Xu Yan; Gao Yufeng

    2001-01-01

    Objective: To measure the serum leptin concentration in simple obese children together with other four kinds of related hormones. Methods: Serum Leptin, Ins, T 3 , T 4 and GH levels were measured by radioimmunoassay in thirty-eight obese children and thirty healthy controls. Results: The levels of serum leptin, Ins and T 3 in obese group were dramatically higher than those in control group (all P 4 concentration between simple obese children and control group (P > 0.05), Serum GH levels was significantly decreased in simple obese children (P < 0.01). There was a positive correlation between serum leptin levels and lns levels (r = 0.46, P < 0.01). Conclusion: In simple obese children there were leptin resistance and endocrine metabolic disturbances, the later might be correlated with the increasing of serum leptin levels; It is suggested that Leptin resistance might play a key role in the development of obesity

  8. Leptin hormone in obese and non-obese stable and exacerbated cases of chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Ahmad Elsayed Mahmoud

    2015-07-01

    Conclusion: Serum leptin hormone level (ng/ml was significantly higher in obese COPD cases than in controls and non-obese cases and during exacerbation than in stability which indicates that leptin plays a role in the systemic inflammatory process. Serum leptin hormone level positively correlated with BMI (kg/m2.

  9. Structure of Leptin Receptor Related with Obesity

    DEFF Research Database (Denmark)

    Toleikis, Zigmantas

    of the receptor, while the D5 domain is the central leptin-binding domain, implicated in the first steps of activation. Both domains are characterized by a fibronectin type III fold and both contain a conserved WSXWS motif (X represents an unconserved amino acid residue), a distinct feature of the cytokine...... receptors. This motif is thought to play a major role in correct folding and activation of the receptor. The complex between leptin and the D5CA domain was analyzed using nuclear magnetic resonance spectroscopy and the amino acid residues implicated in the binding were determined. To investigate which parts...... interactions between the aromatic residues of the peptide. It may be speculated that these differences affect the ability of the full domains to form alternative structures around the WSXWS motif....

  10. Renaissance of leptin for obesity therapy

    DEFF Research Database (Denmark)

    Quarta, Carmelo; Sánchez-Garrido, Miguel A; Tschöp, Matthias H

    2016-01-01

    leptin coming back?' symposium at the 2015 annual meeting of the EASD. It is accompanied by two other reviews on topics from this symposium (by Thomas Meek and Gregory Morton, DOI: 10.1007/s00125-016-3898-3 , and by Gerald Shulman and colleagues, DOI: 10.1007/s00125-016-3909-4 ) and an overview...... by the Session Chair, Ulf Smith (DOI: 10.1007/s00125-016-3894-7 )....

  11. Common Genetic Components of Obesity Traits and Serum Leptin

    DEFF Research Database (Denmark)

    Hasselbalch, Ann L; Benyamin, Beben; Visscher, Peter M

    2008-01-01

    To estimate common and distinct genetic influences on a panel of obesity-related traits and serum leptin level in adults. In a cross-sectional study of 625 Danish, adult, healthy, monozygotic, and same-sex dizygotic twin pairs of both genders, we carried out detailed anthropometry (height, weight...... components, which suggests that it is important to distinguish between the different phenotypes in the search for genes involved in the development of obesity.Obesity (2008) doi:10.1038/oby.2008.440........ For leptin vs. the various measures of overall and local fatness the correlations ranged from 0.54 to 0.74 in men and from 0.48 to 0.75 in women. All correlations were significantly different genetic...

  12. Elevated serum leptin levels are associated with good nutritional status in non-obese chronic hemodialysis patients.

    Science.gov (United States)

    Kara, Ekrem; Ahbap, Elbis; Sahutoglu, Tuncay; Sakaci, Tamer; Basturk, Taner; Koc, Yener; Sevinc, Mustafa; Akgol, Cuneyt; Ucar, Zuhal Atan; Kayalar, Arzu Ozdemir; Bayraktar, Feyza; Unsal, Abdulkadir

    2015-03-01

    Leptin is a hormone and a proinflammatory cytokine secreted from adipocytes, which functions to suppress appetite in healthy persons. Serum leptin levels are significantly elevated in patients with end-stage renal disease (ESRD) primarily due to decreased clearance by the kidneys The consequence of hyperleptinemia in ESRD is not fully understood. We aimed to investigate the association between serum leptin levels and nutrition/inflammation status in non-obese chronic hemodialysis (HD) patients. 65 chronic, anuric, nonobese (body mass index (BMI) nutrition and inflammation status. Patients were classified into the 3 groups according to serum leptin levels; group 1 (low leptin, n = 9), group 2 (normal leptin, n = 31), and group 3 (high leptin, n = 25). Mean age and duration on dialysis of 65 patients (male/female: 34/31) were 51.6 ± 17.8 years and 78.0 ± 67.9 months, respectively. Serum leptin levels increased with older age, female gender, higher BMI and triceps skinfold thickness. Elevated serum leptin levels were significantly associated with good nutritional status parameters, such as higher albumin (p = 0.001), prealbumin (p = 0.033), total iron binding capacity (p = 0.045), total cholesterol (p = 0.041), and lower malnutrition inflammation score (MIS) (p = 0.002). Serum leptin levels remained a negative correlation with MIS after adjustments made for BMI. No correlation was established between leptin and inflammation parameters including ferritin, highly sensitive C-reactive protein (hs-CRP), and tumor necorsis factor alpha (TNF-α). Elevated serum leptin levels seem to be associated with good nutritional status. However, there was no correlation between leptin and inflammatory status.

  13. Clinical value of combined determining leptin, T and E2 in male teenager obesity patients

    International Nuclear Information System (INIS)

    Bai Zhenlian; Lv Tongqin; Wu Qiuhua

    2006-01-01

    To study clinical significance of combined detection of leptin, T and E 2 for teenager obesity patients, levels of leptin, T and E 2 in male teenagers obesity patients and male adult obesity patients were determined by RIA. The result showed that in all obesity patients, the levels of leptin and E 2 were much higher than those in normal controls and T was lower than that in normal controls. After treatment, leptin and E 2 were decreased and T was increased significantly in teenager obesity patients, but only leptin was decreased in adult obesity patients. All results indicate that combined detection of leptin, T and E 2 could find endocrine and metabolism disorder of obese teenagers at early stage, instituting prevention and treatment without delay.(authors)

  14. Neonatal exposure to leptin augments diet-induced obesity in leptin-deficient Ob/Ob mice.

    Science.gov (United States)

    Yura, Shigeo; Itoh, Hiroaki; Sagawa, Norimasa; Yamamoto, Hiroshi; Masuzaki, Hiroaki; Nakao, Kazuwa; Kawamura, Makoto; Mogami, Haruta; Ogawa, Yoshihiro; Fujii, Shingo

    2008-06-01

    Epidemiological evidence has revealed that undernutrition in utero is closely associated with obesity and related detrimental metabolic sequelae in adulthood. Recently, using a wild-type (wt) mouse model in which offspring were exposed to intrauterine undernutrition (UN offspring), we reported that the premature leptin surge during neonatal growth promotes lifelong changes in energy regulating circuitry in the hypothalamus, thus playing an important role in the development of pronounced obesity on a high-fat diet (HFD) in adulthood. Here, we further evaluate the essential involvement of leptin in the developmental origins of obesity using leptin-deficient ob/ob mice. We assessed the progression of obesity on an HFD in adult leptin-deficient ob/ob male mice that were exposed to intrauterine undernutrition by maternal food restriction (ob/ob UN offspring) or to leptin treatment during the neonatal period; this treatment is comparable to the premature leptin surge observed in the wt-UN offspring. On an HFD, the body weight of the male ob/ob UN offspring paralleled that of the ob/ob offspring exposed to normal intrauterine nutrition (ob/ob NN offspring). In contrast, early exposure to leptin in the ob/ob NN offspring during early neonatal growth reproduced the development of pronounced obesity on an HFD in adulthood. The presence of leptin and associated energy regulation are indispensable in the acceleration of obesity on an HFD caused by undernutrition in utero. The premature leptin surge plays an essential role in the developmental origins of obesity as a programming signal during the early neonatal period.

  15. Fasting and postprandial levels of ghrelin, leptin and insulin in lean, obese and anorexic subjects

    Science.gov (United States)

    Krauss, Hanna; Gibas-Dorna, Magdalena; Kupsz, Justyna; Piątek, Małgorzata; Piątek, Jacek

    2013-01-01

    Introduction Ghrelin, leptin and insulin are involved in neurohormonal regulation of energetic homeostasis. Aim We investigated the correlation between nutritional status and plasma levels of leptin, ghrelin and insulin in lean, obese and anorexic subjects. Material and methods Nineteen obese and 18 anorexic adults were enrolled in the study. Seventeen adults with normal body mass index (BMI) served as controls. Blood samples were taken twice: before breakfast and 2 h after breakfast. Fasting and postprandial ghrelin, leptin and insulin were examined. The following correlations were estimated: between BMI and basal level of tested hormones, between insulin and ghrelin, and between insulin and leptin. The threshold level of significance was p ≤ 0.05 for all calculations. Results Basal insulin level was lowest in anorexic patients and greatest in obese subjects. Fasting plasma ghrelin was lower in obesity and higher in anorexia as compared with the controls. Comparing with controls, fasting leptin levels were higher in obese and lower in anorexic subjects. There was positive correlation between BMI and basal leptin level in obesity. A significant postprandial increase was noted for insulin in all studied groups. Increased leptin and decreased ghrelin levels were detected 2 h after a meal in the control group. In obese patients, postprandial leptin was lower than before food intake, and fasting leptin showed positive correlation with basal insulin level. Conclusions Basal plasma ghrelin, leptin and insulin levels differ according to nutritional status. Impaired ghrelin and leptin secretion and insulin sensitivity may be involved in the pathogenesis of eating disorders. PMID:24868288

  16. Relationship between expression of leptin receptors mRNA in breast tissue, plasma leptin level in breast cancer patients with obesity and clinical pathologic data

    International Nuclear Information System (INIS)

    Li Chunrui; Liu Wenli; Sun Hanying; Zhou Jianfeng

    2007-01-01

    In order to investigate the expression of leptin receptors mRNA in breast tissue and plasma leptin levels in breast cancer patients with obesity and their relationship with clinical pathologic data, 124 subjects who were either obesity or had suffered from breast benign disease with obesity, or breast cancer with obesity were entered into this study. The levels of plasma leptin in all subjects were determined and leptin receptors mRNA expression levels were measured by RT-PCR in breast tissue of breast cancer patients with obesity and breast benign disease with obesity. The results showed that plasma leptin levels in breast cancer patients with obesity were significantly higher than those in breast benign disease with obesity and obesity patients alone (P<0.05). The expression of the leptin receptor long form [-Lep-R(L)-] mRNA and the leptin receptor short form [-Lep-R(S)-] mRNA in breast tissue of breast cancer patients with obesity were significantly higher than that in breast tissue of breast benign disease patients with obesity (P<0.05). The plasma leptin level had remarkable positive correlation with the expressions of the Lep-R(L) mRNA and the Lep-R(S) mRNA. The plasma leptin level and leptin receptors mRNA expression levels in patients were not correlated with the axillary node metastasis, menopause, the TNM stage or pathological type. Therefore, leptin may have a promoting effect on the carcinogenesis of breast cancer. (authors)

  17. Obesity-Related Hypertension: Focus on Leptin

    DEFF Research Database (Denmark)

    Asferg, Camilla Lundegaard

    distinguish obese normotensive men from obese hypertensives men. Methods: The following study designs were used: large-scale epidemiological studies using cross-sectional and prospective data from The Copenhagen City Heart Study (CCHS) and a detailed descriptive cross-sectional study of 130 males. The CCHS...

  18. 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

  19. Feeding and temperature responses to intravenous leptin infusion are differential predictors of obesity in rats

    NARCIS (Netherlands)

    Ruffin, M.; Adage, T; Kuipers, F; Strubbe, J H; Scheurink, A J W; van Dijk, G; Ruffin, Marie-Pierre

    2004-01-01

    Obesity is frequently associated with leptin resistance. The present study investigated whether leptin resistance in rats is present before obesity develops, and thus could underlie obesity induced by 16 wk exposure to a liquid, palatable, high-energy diet (HED). Before HED exposure, male Wistar

  20. Fatty acid-binding protein 2 Ala54Thr genotype is associated with insulin resistance and leptin levels changes after a high monounsaturated fat diet in obese non-diabetic patients.

    Science.gov (United States)

    de Luis, D A; Aller, R; Izaola, O; Gonzalez Sagrado, M; Conde, R

    2013-06-01

    It has been found that the expression of fatty acid binding protein 2 (FABP2) mRNA is under dietary control. This polymorphism was associated with high insulin resistance, and fasting insulin concentrations. The aim of our study was to investigate the influence of Thr54 polymorphism in the FABP2 gene on metabolic response, weight loss and serum adipokine levels secondary to a high monounsaturated fat hypocaloric diet. A sample of 122 obese patients was analyzed in a prospective way. The hypocaloric diet had 1342 kcal, 46.6% of carbohydrates, 34.1% of lipids and 19.2% of proteins, with a 67.5% of monounsaturated fats, and lasted 3 months. Fifty-five patients (45.1%) had the genotype Ala54/Ala54 (wild group) and 67 (64.9%) patients a mutant genotype, Ala54/Thr54 (54 patients, 44.3%) or Thr54/Thr54 (13 patients, 10.7%). In wild group, body mass index (-1.5±1.2 kg/m2), weight (-4.1±3.6 kg), fat mass (-3.6±3.3 kg), waist circumference (-4.9±2.9 cm), insulin (-1.7±3.6 mUI/l), homeostasis model assessment of insulin resistance (HOMA-IR) (-0.6±1.8 units) and leptin levels decreased (-7.6±7.1 ng/ml). In mutant group, anthropometric parameters improved, without changes in biochemical parameters. Carriers of Thr54 allele have a different response than wild type obese, with a lack of decrease of insulin levels, leptin levels and HOMA-IR.

  1. Positive association of plasma leptin with sleep quality in obese type 2 diabetes patients.

    Science.gov (United States)

    Hirota, Tomoe; Morioka, Tomoaki; Yoda, Koichiro; Toi, Norikazu; Hayashi, Noriyuki; Maruo, Saori; Yamazaki, Yuko; Kurajoh, Masafumi; Motoyama, Koka; Yamada, Shinsuke; Shoji, Tetsuo; Emoto, Masanori; Inaba, Masaaki

    2018-02-26

    Poor sleep quality is associated with obesity and diabetes. The adipocyte-derived hormone, leptin, was recently shown to underlie the link between abnormal sleep and obesity. We aimed to investigate the association between leptin and sleep quality in type 2 diabetes patients. In the present cross-sectional study, we studied 182 type 2 diabetes patients, among whom 113 were diagnosed with obesity (body mass index ≥25 kg/m 2 ). Fasting plasma leptin levels were measured, and sleep architecture was assessed using single-channel electroencephalography. Using unadjusted analyses, the obese type 2 diabetes patients, but not their non-obese counterparts, showed a positive correlation between plasma leptin levels and a parameter for deep sleep assessed by delta power during the first sleep cycle. Multivariate analysis showed that plasma leptin levels were positively associated with delta power, but not with the total sleep time, after adjusting for potential confounders including age, body mass index and the apnea-hypopnea index, in the obesity group. However, neither delta power nor total sleep time was associated with leptin in the non-obesity group. Plasma leptin levels are independently associated with sleep quality in obese, but not in non-obese, type 2 diabetes patients. The present study indicates a favorable relationship between leptin and sleep quality in obese type 2 diabetes patients. © 2018 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

  2. Milk Leptin Surge and Biological Rhythms of Leptin and Other Regulatory Proteins in Breastmilk.

    Science.gov (United States)

    Nozhenko, Yuriy; Asnani-Kishnani, Madhu; Rodríguez, Ana M; Palou, Andreu

    2015-01-01

    A significant number of chronic diseases are linked to perinatal nutrition, and prevention may be associated to naturally occurring components of breast milk. One key hormone in breast milk is leptin, related with the protection from obesity in the adulthood, thus knowing its changes through the day or lactation is crucial. We aimed to investigate the daily rhythms in the milk levels of leptin, together with other two related hormones, ghrelin and adiponectin, during lactation (days 5, 10 and 15) in rat dams, and the relation with morphometric parameters (dams and pups). Summarizing the main results, the existence of biological rhythms, but not daily and maybe circasemidian, was confirmed for the three hormones at the earliest period of lactation. The correlations performed generally showed a possible dependence of milk hormone levels on plasma levels at the early phase of lactation, while with the progression of lactation this dependence may fade and the hormone levels are suggested to be more dependent on mammary gland production/maturation. There was also a correlation between milk leptin and adiponectin levels, especially in the first half of lactation, suggesting a possible parallel regulation. Interestingly, we describe a milk leptin surge around the mid of lactation (at day 10) which may be related with pup's growth (males and females) and with the well-known (in the literature) plasma leptin surge in pups. All this knowledge may be crucial for future applications in the development of formula milk and in relation with the role of leptin surge during lactation.

  3. Leptin and Fasting Regulate Rat Gastric Glucose-Regulated Protein 58

    Directory of Open Access Journals (Sweden)

    Susana B. Bravo

    2011-01-01

    Full Text Available The stomach secretes a wide range of peptides with essential metabolic functions, and thereby plays an important role in the regulation of energy homeostasis. Disulfide isomerase glucose-regulated protein 58 (GRp58 is a molecular chaperone member of the endoplasmic reticulum (ER stress signaling pathway, which is a marker for human gastric cancer. Since GRp58 seems to be regulated by a phosphorylation/dephosphorylation pattern shift, we used the 2DE gel methodology and peptide mass fingerprinting-protein identification by means of MALDI-TOF mass spectrometry. We show that gastric mucosa GRp58 is dephosphorylated by fasting, and this effect is blunted when fasted rats are treated with leptin. Furthermore, we assessed the gene expression of GRp58 under different physiological settings known to be associated with energy homeostasis (fasting, leptin treatment and leptin deficiency. We found that intraperitoneal administration of leptin increases whereas leptin deficiency decreases GRp58 mRNA levels. However, GRp58 expression remains unchanged after fasting, indicating that leptin actions on GRp58 are no direct sensitivity to fasting. Dissection of the molecular pathways mediating the interactions between ER stress-related factors and nutrient availability, as well as their target genes, may open a new avenue for the study of obesity and other metabolic disorders.

  4. Placental ghrelin and leptin expression and cord blood ghrelin, adiponectin, leptin, and C-peptide levels in severe maternal obesity.

    Science.gov (United States)

    Allbrand, Marianne; Åman, Jan; Lodefalk, Maria

    2017-08-08

    The purpose of this study is to investigate placental ghrelin and leptin expression as well as cord blood ghrelin and adiponectin levels in maternal obesity and associations between placental ghrelin expression, cord blood ghrelin levels and maternal and infant variables. Placental ghrelin and leptin expression were analyzed by RT-PCR in 32 severely obese and 32 matched normal-weight women. Cord blood ghrelin, adiponectin, leptin, and C-peptide concentrations were analyzed by ELISA. Neither ghrelin nor leptin expression and neither cord blood ghrelin nor adiponectin levels differed between the groups. Placental ghrelin expression was associated with BMI at delivery in the obese women (r = 0.424, p = .016) and in the infants born to normal-weight women with their weight z-scores at six (r = -0.642, p = .010), nine (r = -0.441, p = .015), and 12 months of age (r = -0.402, p = .028). Placental ghrelin and leptin expression as well as cord blood ghrelin and adiponectin levels do not seem to be altered in severe maternal obesity. Placenta-derived ghrelin may influence the infants' postnatal weight gain, but possibly only when the mother has normal weight.

  5. 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

  6. [Role of leptin and leptin resistance in non-alcoholic fatty liver disease development in persons with obesity and overweight].

    Science.gov (United States)

    Livzan, M A; Lapteva, I V; Miller, T S

    2014-01-01

    To study the impact of leptin and leptinresistance on formation of non-alcoholic fatty liver disease (NAFLD) of people with obesity and overweight. 105 patients with obesity and overweight were examined, among them 19 men and 86 women, median age 58 (50-63) years. Risk factors development NAFLD, anthropometric indices, biochemical analysis of blood, abdominal ultrasonic studies, levels leptin and its soluble receptor were estimated. examined people with NAFLD were included into 2 groups: main group (patients NAFLD, n = 77) and comparison group (n = 28). Waist volume, body mass index, blood glucose were higher in group of patients with NAFLD (p liver development (rs = (0.376), p obesity and overweight negative correlation of moderate strength (rs = (-0.370), p obesity and excess body weight, phenomenon of leptinresistance arises to patients with obesity and can be considered as predictor of the development and progression of NAFLD among this category of patients.

  7. Neuroprotective effects of leptin in the context of obesity and metabolic disorders.

    Science.gov (United States)

    Davis, Cecilia; Mudd, Jeremy; Hawkins, Meredith

    2014-12-01

    As the population of the world ages, the prevalence of neurodegenerative disease continues to rise, accompanied by increases in disease burden related to obesity and metabolic disorders. Thus, it will be essential to develop tools for preventing and slowing the progression of these major disease entities. Epidemiologic studies have shown strong associations between obesity, metabolic dysfunction, and neurodegeneration, while animal models have provided insights into the complex relationships between these conditions. Experimentally, the fat-derived hormone leptin has been shown to act as a neuroprotective agent in various animal models of dementia, toxic insults, ischemia/reperfusion, and other neurodegenerative processes. Specifically, leptin minimizes neuronal damage induced by neurotoxins and pro-apoptotic conditions. Leptin has also demonstrated considerable promise in animal models of obesity and metabolic disorders via modulation of glucose homeostasis and energy intake. However, since obesity is known to induce leptin resistance, we hypothesize that resistance to the neuroprotective effects of leptin contributes to the pathogenesis of obesity-associated neurodegenerative diseases. This review aims to explore the literature pertinent to the role of leptin in the protection of neurons from the toxic effects of aging, obesity and metabolic disorders, to investigate the physiological state of leptin resistance and its causes, and to consider how leptin might be employed therapeutically in the prevention and treatment of neurodegenerative disease. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Serum Leptin and Skeletal Differences between Obese and Non-Obese Patients with Chronic Obstructive Pulmonary Disease

    Directory of Open Access Journals (Sweden)

    Marta Koršić

    2014-11-01

    Full Text Available Objective: Chronic obstructive pulmonary disease (COPD affects body composition, adipokine secretion, and skeletal integrity. The aim was to determine the association between leptin, body mass (BM and body composition parameters - fat mass (FM and fat mass index (FMI, lean tissue mass (LTM, lean tissue mass index (LTMI and bone mineral density (BMD in 67 male COPD patients. Methods: BM, body composition and biochemical indicators were measured or calculated using standard methods. Data were analyzed according to groups: non-obese (N = 48, BMI 21.0-29.9 kg/m2 and obese (N = 19, BMI ≥ 30.0 kg/m2. Results: In the non-obese group statistically significant correlations were observed: negative ones of age with most BMD T scores, positive ones of BMI with all T scores, FM, FMI, LTMI and leptin, of FMI with leptin and all T scores, and of LTMI with most T scores. In the obese group also statistically significant correlations were found: positive ones of BMI with FMI, LTM, leptin and T scores (trochanter, total hip; of FMI with leptin; and of leptin with total hip T score. Conclusion: A positive relationship between FMI and BMD was found only in non-obese but not in obese COPD patients. Leptin concentration was associated positively with the total hip T score only in obese COPD patients, suggesting its protective role on the skeleton of obese COPD patients.

  9. Serum leptin and skeletal differences between obese and non-obese patients with chronic obstructive pulmonary disease.

    Science.gov (United States)

    Koršić, Marta; Kušec, Vesna

    2014-01-01

    Chronic obstructive pulmonary disease (COPD) affects body composition, adipokine secretion, and skeletal integrity. The aim was to determine the association between leptin, body mass (BM) and body composition parameters - fat mass (FM) and fat mass index (FMI), lean tissue mass (LTM), lean tissue mass index (LTMI) and bone mineral density (BMD) in 67 male COPD patients. BM, body composition and biochemical indicators were measured or calculated using standard methods. Data were analyzed according to groups: non-obese (N = 48, BMI 21.0-29.9 kg/m(2)) and obese (N = 19, BMI ≥ 30.0 kg/m(2)). In the non-obese group statistically significant correlations were observed: negative ones of age with most BMD T scores, positive ones of BMI with all T scores, FM, FMI, LTMI and leptin, of FMI with leptin and all T scores, and of LTMI with most T scores. In the obese group also statistically significant correlations were found: positive ones of BMI with FMI, LTM, leptin and T scores (trochanter, total hip); of FMI with leptin; and of leptin with total hip T score. A positive relationship between FMI and BMD was found only in non-obese but not in obese COPD patients. Leptin concentration was associated positively with the total hip T score only in obese COPD patients, suggesting its protective role on the skeleton of obese COPD patients.

  10. Polymorphism in leptin receptor gene was associated with obesity in ...

    African Journals Online (AJOL)

    Pramudji Hastuti

    2016-01-11

    Jan 11, 2016 ... Abstract Background: Leptin is a hormone that regulates homeostasis energy through the cen- tral–peripheral mechanism as well as regulates hunger and satiety. Leptin receptor is important in leptin signal transduction that is located mainly in the hypothalamus. The mutation in leptin receptor (LEPR) gene ...

  11. Polymorphism in leptin receptor gene was associated with obesity in ...

    African Journals Online (AJOL)

    Background: Leptin is a hormone that regulates homeostasis energy through the central– peripheral mechanism as well as regulates hunger and satiety. Leptin receptor is important in leptin signal transduction that is located mainly in the hypothalamus. The mutation in leptin receptor (LEPR) gene causes splicing ...

  12. Milk Leptin Surge and Biological Rhythms of Leptin and Other Regulatory Proteins in Breastmilk.

    Directory of Open Access Journals (Sweden)

    Yuriy Nozhenko

    Full Text Available A significant number of chronic diseases are linked to perinatal nutrition, and prevention may be associated to naturally occurring components of breast milk. One key hormone in breast milk is leptin, related with the protection from obesity in the adulthood, thus knowing its changes through the day or lactation is crucial. We aimed to investigate the daily rhythms in the milk levels of leptin, together with other two related hormones, ghrelin and adiponectin, during lactation (days 5, 10 and 15 in rat dams, and the relation with morphometric parameters (dams and pups. Summarizing the main results, the existence of biological rhythms, but not daily and maybe circasemidian, was confirmed for the three hormones at the earliest period of lactation. The correlations performed generally showed a possible dependence of milk hormone levels on plasma levels at the early phase of lactation, while with the progression of lactation this dependence may fade and the hormone levels are suggested to be more dependent on mammary gland production/maturation. There was also a correlation between milk leptin and adiponectin levels, especially in the first half of lactation, suggesting a possible parallel regulation. Interestingly, we describe a milk leptin surge around the mid of lactation (at day 10 which may be related with pup's growth (males and females and with the well-known (in the literature plasma leptin surge in pups. All this knowledge may be crucial for future applications in the development of formula milk and in relation with the role of leptin surge during lactation.

  13. Serum leptin concentration, obesity, and insulin resistance in Western Samoans: cross sectional study.

    OpenAIRE

    Zimmet, P.; Hodge, A.; Nicolson, M.; Staten, M.; de Courten, M.; Moore, J.; Morawiecki, A.; Lubina, J.; Collier, G.; Alberti, G.; Dowse, G.

    1996-01-01

    OBJECTIVE: To measure serum leptin concentrations in the Polynesian population of Western Samoa and to examine epidemiological associations of leptin with anthropometric, demographic, behavioural, and metabolic factors in this population with a high prevalence of obesity and non-insulin dependent diabetes mellitus. DESIGN: Cross sectional study, leptin concentration being measured in a subgroup of a population based sample. SUBJECTS: 240 Polynesian men and women aged 28-74 years were selected...

  14. Astrocytes Modulate Distribution and Neuronal Signaling of Leptin in the Hypothalamus of Obese Avy Mice

    OpenAIRE

    Pan, Weihong; Hsuchou, Hung; Xu, Changlei; Wu, Xiaojun; Bouret, Sebastien G.; Kastin, Abba J.

    2010-01-01

    We tested the hypothesis that astrocytic activity modulates neuronal uptake and signaling of leptin in the adult-onset obese agouti viable yellow (Avy) mouse. In the immunohistochemical study, Avy mice were pretreated with the astrocyte metabolic inhibitor fluorocitrate or phosphate-buffered saline (PBS) vehicle intracerebroventricularly (icv) followed 1 h later by Alexa568-leptin. Confocal microscopy showed that fluorocitrate pretreatment reduced astrocytic uptake of Alexa568-leptin 30 min a...

  15. Role of leptin during perinatal metabolic programming and obesity.

    Science.gov (United States)

    Djiane, J; Attig, L

    2008-08-01

    The incidence of obesity is rapidly increasing all over the world in epidemic proportions.The epidemia now affects young children and accumulative evidences suggest that the origin of the disease may occur during foetal development and early life. This has introduced the concept of "developmental programming" supported by experimental studies in animal models and numerous epidemiological data. This concept supports the idea that nutritional and hormonal status during pregnancy and early life could interfere irreversibly on the development of the organs involved in the control of food intake and metabolism and particularly the hypothalamic structures responsible of the establishment of the ingestive behaviour and regulation of energy expenditure. The mechanisms responsible of this developmental programming remain poorly documented. However, recent research indicate that the adipokine leptin plays a critical role in this programming.

  16. Leptin, abdominal obesity, and onset of depression in older men and women

    NARCIS (Netherlands)

    Milaneschi, Y.; Simonsick, E.M.; Vogelzangs, N.; Strotmeyer, E.S.; Yaffe, K.; Harris, T.B.; Tolea, M.I.; Ferrucci, L.; Penninx, B.W.J.H.

    2012-01-01

    Objective: The mechanisms that underlie the association between abdominal obesity and depression risk in older persons are not well known, but the "leptin hypothesis" of depression suggests that leptin resistance may be involved in mood regulation. We tested whether high circulatory concentration of

  17. Leptin levels are associated with fat oxidation and dietary-induced weight loss in obesity

    DEFF Research Database (Denmark)

    Verdich, C; Toubro, S; Buemann, B

    2001-01-01

    To examine the relationship between fasting plasma leptin and 24-hour energy expenditure (EE), substrate oxidation, and spontaneous physical activity (SPA) in obese subjects before and after a major weight reduction compared with normal weight controls. To test fasting plasma leptin, substrate...... oxidations, and SPA as predictive markers of success during a standardized weight loss intervention....

  18. Leptin levels are associated with fat oxidation and dietary-induced weight loss in obesity

    DEFF Research Database (Denmark)

    Verdich, C; Toubro, S; Buemann, B

    2001-01-01

    To examine the relationship between fasting plasma leptin and 24-hour energy expenditure (EE), substrate oxidation, and spontaneous physical activity (SPA) in obese subjects before and after a major weight reduction compared with normal weight controls. To test fasting plasma leptin, substrate ox...... oxidations, and SPA as predictive markers of success during a standardized weight loss intervention....

  19. Reference values for serum leptin in healthy non-obese children and adolescents

    DEFF Research Database (Denmark)

    Lausten-Thomsen, Ulrik; Christiansen, Michael; Hedley, Paula Louise

    2016-01-01

    . Methods: A total of 1193 healthy, non-obese Danish schoolchildren (730 girls, 463 boys) aged 6–18 years (median 11.9) were examined by trained medical staff. Serum leptin and sOB-R concentrations in venous fasting blood samples were quantitated by immunoassay. Percentile curves of leptin, sOB-R, and free...

  20. Serum leptin concentration, obesity, and insulin resistance in Western Samoans: cross sectional study.

    Science.gov (United States)

    Zimmet, P; Hodge, A; Nicolson, M; Staten, M; de Courten, M; Moore, J; Morawiecki, A; Lubina, J; Collier, G; Alberti, G; Dowse, G

    1996-10-19

    To measure serum leptin concentrations in the Polynesian population of Western Samoa and to examine epidemiological associations of leptin with anthropometric, demographic, behavioural, and metabolic factors in this population with a high prevalence of obesity and non-insulin dependent diabetes mellitus. Cross sectional study, leptin concentration being measured in a subgroup of a population based sample. 240 Polynesian men and women aged 28-74 years were selected to cover the full range of age, body mass index, and glucose tolerance. Serum leptin, insulin, and glucose concentrations; anthropometric measures; physical activity; and area of residence. Leptin concentrations were correlated with body mass index (r = 0.80 in men, 0.79 in women) and waist circumference (r = 0.82 in men, 0.78 in women) but less so with waist to hip ratio. At any body mass index, leptin concentration was higher in women than men (geometric mean adjusted for body mass index 15.3 v 3.6 pg/l, P < 0.001). Leptin concentration also correlated with fasting insulin concentration (r = 0.63 in men, 0.64 in women) and insulin concentration 2 hours after a glucose load (r = 0.58 in men, 0.52 in women). These associations remained significant after controlling for body mass index; effects of physical activity and of rural or urban living on leptin concentration were eliminated after adjusting for obesity, except values remained high in urban men. 78% of variance in leptin was explained by a model including fasting insulin concentration, sex, body mass index, and a body mass index by sex interaction term. Similar results were obtained if waist circumference replaced body mass index. The strong relation of leptin with obesity is consistent with leptin production being proportional of mass to adipose tissue. The relation with insulin independent of body mass index suggests a possible role for leptin in insulin resistance or hyperinsulinaemia.

  1. 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

  2. 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......) exposure. Here we assess whether a single peptide possessing balanced coagonism at the glucagon-like peptide 1 (GLP-1) and glucagon receptors can restore leptin responsiveness in DIO mice maintained on a HFD. DIO mice were treated with PEG-GLP-1/glucagon (30 nmol/kg every fourth day) to induce an ∼15% body...

  3. Astrocytes modulate distribution and neuronal signaling of leptin in the hypothalamus of obese A vy mice.

    Science.gov (United States)

    Pan, Weihong; Hsuchou, Hung; Xu, Changlei; Wu, Xiaojun; Bouret, Sebastien G; Kastin, Abba J

    2011-03-01

    We tested the hypothesis that astrocytic activity modulates neuronal uptake and signaling of leptin in the adult-onset obese agouti viable yellow (A vy) mouse. In the immunohistochemical study, A vy mice were pretreated with the astrocyte metabolic inhibitor fluorocitrate or phosphate-buffered saline (PBS) vehicle intracerebroventricularly (icv) followed 1 h later by Alexa568-leptin. Confocal microscopy showed that fluorocitrate pretreatment reduced astrocytic uptake of Alexa568-leptin 30 min after icv while increasing neuronal uptake in the arcuate nucleus and dorsomedial hypothalamus. Fluorocitrate also induced mild astrogliosis and moderately increased pSTAT3 immunopositive neurons in response to Alexa568-leptin in the dorsomedial hypothalamus. In the Western blotting study, A vy mice were pretreated with either PBS or fluorocitrate, and received PBS or leptin 1 h later followed by determination of pSTAT3 and GFAP expression an additional 30 min afterward. The results show that fluorocitrate induced a mild pSTAT3 activation but attenuated leptin-induced pSTAT3 activation and decreased GFAP expression independently of leptin treatment. We conclude that inhibition of astrocytic activity resulted in enhanced neuronal leptin uptake and signaling. This suggests opposite roles of astrocytes and neurons in leptin's actions in the A vy mouse with adult-onset obesity.

  4. 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.

  5. Effects of weight loss on leptin, sex hormones, and measures of adiposity in obese children.

    Science.gov (United States)

    Sudi, K M; Gallistl, S; Borkenstein, M H; Payerl, D; Aigner, R; Möller, R; Tafeit, E

    2001-04-01

    Adipose tissue influences steroid conversion by paracrine and autocrine mechanisms. Leptin is secreted by adipocytes and influenced by sex hormones and adiposity. Short-term weight loss in the treatment of childhood obesity reduces leptin and adipose tissue. We therefore asked, Do alterations in sex hormones occur owing to weight loss? and can these alterations be explained by changes in fat mass or sc fat and are alterations in sex hormones directly related to the fall in leptin? Twenty obese boys and 40 obese girls were studied before and after 3 wk of low-calorie diet and physical activity. The weight loss program significantly lowered fat mass, abdominal fat distribution, sc fat (all p testosterone. Changes in leptin were related to changes in body mass and to changes in fat mass in boys. In girls, changes in leptin were related to changes in sc fatness and also to changes in insulin. In boys, the reduction in sc fat was positively correlated to changes in testosterone (r = 0.54; p testosterone (r = 0.33; p fat depots in boys whereas in girls changes in insulin might participate in changes in sex hormones. A greater fall in leptin owing to short-term weight loss is not associated with greater alterations in sex hormones and initial leptin is the best determinant to explain the variability in changes in leptin. The possibility of sex differences in changes in sex hormones secondary to the reduction in fatness warrants further study.

  6. Influence of dexamethasone and weight loss on the regulation of serum leptin levels in obese individuals

    Directory of Open Access Journals (Sweden)

    Lerario D.D.G.

    2001-01-01

    Full Text Available The adipocyte hormone leptin is thought to serve as a signal to the central nervous system reflecting the status of fat stores. Serum leptin levels and adipocyte leptin messenger RNA levels are clearly increased in obesity. Nevertheless, the factors regulating leptin production are not fully understood. The aim of this study was to determine the effects of in vivo administration of the synthetic glucocorticoid dexamethasone and weight loss on serum leptin levels in two independent protocols. Twenty-five obese subjects were studied (18 women and 7 men, mean age 26.6 ± 6 years, BMI 31.1 ± 2.5 kg/m², %fat 40.3 ± 8.3 and compared at baseline to 22 healthy individuals. Serum levels of leptin, insulin, proinsulin and glucose were assessed at baseline and after ingestion of dexamethasone, 4 mg per day (2 mg, twice daily for two consecutive days. To study the effects of weight loss on serum leptin, 17 of the obese subjects were submitted to a low-calorie dietary intervention trial for 8 weeks and again blood samples were collected. Serum leptin levels were significantly higher in the obese group compared to the control group and a high positive correlation between leptinemia and the magnitude of fat mass was found (r = 0.88, P<0.0001. After dexamethasone, there was a significant increase in serum leptin levels (22.9 ± 12.3 vs 51.4 ± 23.3 ng/ml, P<0.05. Weight loss (86.1 ± 15.1 vs 80.6 ± 14.2 kg, P<0.05 led to a reduction in leptin levels (25.13 ± 12.8 vs 15.9 ± 9.1 ng/ml, P<0.05. We conclude that serum leptin levels are primordially dependent on fat mass magnitude. Glucocorticoids at supraphysiologic levels are potent secretagogues of leptin in obese subjects and a mild fat mass reduction leads to a disproportionate decrease in serum leptin levels. This suggests that, in addition to the changes in fat mass, complex nutritional and hormonal interactions may also play an important role in the regulation of leptin levels.

  7. Relationships between changes in leptin and insulin resistance levels in obese individuals following weight loss

    Directory of Open Access Journals (Sweden)

    Tsu-Nai Wang

    2013-08-01

    Full Text Available Obesity can augment insulin resistance (IR, leading to increased risk of diabetes and heart disease. Leptin, ghrelin, and various fatty acids present in the cell membrane may modulate IR. In this study, we aimed to investigate the impact of weight loss on IR, serum leptin/ghrelin levels, and erythrocyte fatty acids, and studied the associations between changes in these variables. A total of 35 obese (body mass index ≥ 27 adults participated in a weight loss program for 3 months. IR was assessed using homeostasis model assessment for insulin resistance (HOMA-IR. The obese participants had a mean weight loss of 5.6 ± 3.8 kg followed by a 16.7% and 23.3% reduction in HOMA-IR and leptin (p  0.05 levels. After adjusting for age, gender, changes in ghrelin, and body fat, we found a significant correlation between decreases in leptin and less risk of no improvement in HOMA-IR levels [odds ratio (OR = 0.69, p = 0.039]. In conclusion, a moderate weight reduction in obese participants over a short period significantly improved IR. This weight reduction concomitantly decreased serum leptin, increased ghrelin, and elevated some erythrocyte unsaturates. Only leptin correlated independently with IR improvement upon multivariable logistic regression analysis, which indicates that leptin may play a role in the modulation of IR following weight loss.

  8. Reference values for serum leptin in healthy non-obese children and adolescents.

    Science.gov (United States)

    Lausten-Thomsen, Ulrik; Christiansen, Michael; Louise Hedley, Paula; Esmann Fonvig, Cilius; Stjernholm, Theresa; Pedersen, Oluf; Hansen, Torben; Holm, Jens-Christian

    2016-11-01

    Adipokines are biologically active, low-molecular weight peptides, which play a major role in metabolic homeostasis in humans. Leptin has gained increasing attention in pediatrics as a biomarker for various metabolic pathologies. Yet, its usefulness is hampered by the relative lack of reference values from pediatric settings. Accordingly, this study aims to evaluate serum concentrations of leptin, soluble leptin receptor (sOB-R), and free leptin index (FLI) in healthy Danish schoolchildren aged 6-18 years and subsequently to establish reference intervals across sex and age groups. A total of 1193 healthy, non-obese Danish schoolchildren (730 girls, 463 boys) aged 6-18 years (median 11.9) were examined by trained medical staff. Serum leptin and sOB-R concentrations in venous fasting blood samples were quantitated by immunoassay. Percentile curves of leptin, sOB-R, and free leptin index were calculated using the General Additive Model for Location Scale and Shape (GAMLSS). Significant age and sex-dependent differences in circulating leptin levels were found. In boys, the median leptin concentration for all ages combined was 3.35 μg/L (95%-interval: 0.71-22.47) and in girls, it was 9.89 ng/L (95%-interval: 2.06-41.49). For SOB-R, no sex-specific difference was found, and the median sOB-R concentration was 8.24 μg/L (IQR: 3.58-23.74; range: < 1.56-744.15). We demonstrated an age-dependent correlation with both serum leptin concentration and free leptin index with a gradual and significant increase in girls throughout childhood and adolescence and a significantly higher leptin concentration and free leptin index bell-shaped peak in early adolescence in boys.

  9. The influence of overweight and obesity on longitudinal trends in maternal serum leptin levels during pregnancy.

    Science.gov (United States)

    Misra, Vinod K; Trudeau, Sheri

    2011-02-01

    Maternal obesity influences a number of metabolic factors that can affect the course of pregnancy. Among these factors, leptin plays an important role in energy metabolism and fetal development during pregnancy. Our objective was to estimate the influence of maternal overweight/obesity on variation in the maternal serum leptin profile during pregnancy. In a prospective cohort of 143 adult gravidas with singleton pregnancies presenting for general prenatal care, we measured serum leptin levels at 6-10, 10-14, 16-20, 22-26, and 32-36 weeks' gestation. The longitudinal effects of maternal prepregnancy BMI, categorized as nonoverweight (≤ 26.0 kg/m(2)) and overweight/obese (>26.0 kg/m(2)), on serum leptin concentration were analyzed using linear mixed models. Overweight/obese women had significantly higher serum leptin concentrations than their nonoverweight counterparts throughout pregnancy (P influence leptin concentrations in overweight/obese women compared to normal-weight women during pregnancy. Such factors may contribute to differences in the intrauterine environment and its influence on pregnancy outcomes in the two groups.

  10. Psychiatric symptoms and leptin in obese patients who were bariatric surgery candidates

    Directory of Open Access Journals (Sweden)

    Changchien TC

    2015-08-01

    Full Text Available Te-Chang Changchien,1 Chi-Ming Tai,2 Chih-Kun Huang,3 Chia-Chang Chien,1 Yung-Chieh Yen1,4 1Department of Psychiatry, E-Da Hospital, 2Department of Internal Medicine, E-Da Hospital, 3Bariatric and Metabolic International Surgery Center, E-Da Hospital, 4School of Medicine, I-Shou University, Kaohsiung, Taiwan Objective: There is a significant relationship between obesity and common mental symptoms (depression and anxiety symptoms. But the association between depression (or anxiety symptoms and serum leptin is still unclear and controversial, despite the growing body of evidence supporting the existence of “leptin resistance” in obese persons. So we investigated whether common mental symptoms, obesity, and the interactive effect of these two factors have a relationship with leptin in obese patients who were candidates for bariatric surgery.Methods: In all, 139 participants (mean age: 31.4 years, standard deviation: 9.3 years, 73.4% female were enrolled at an obesity treatment center in southern Taiwan. Serum leptin levels and body mass index (BMI were measured. The Chinese Health Questionnaire and Taiwanese Depression Questionnaire were administered. Results: The mean BMI of our participants was 39.4 kg/m2 (±6.8, and the mean leptin level was 24.5 ng/mL (±9.4. In the multivariate regression models, Chinese Health Questionnaire-by-BMI and Taiwanese Depression Questionnaire-by-BMI interaction terms remained significant predictors of leptin level (β=0.16, P<0.0001; β=0.04, P<0.0001, respectively, after adjustment for age, sex, and history of hypertension, diabetes, and hyperlipidemia, despite the inverse correlation between Chinese Health Questionnaire (or Taiwanese Depression Questionnaire and leptin. In addition, female patients had significantly higher leptin levels than male patients.Conclusion: The present findings confirmed that the relationship between common mental symptoms and leptin is modulated by obesity in severely obese

  11. Age-related changes in acute central leptin effects on energy balance are promoted by obesity.

    Science.gov (United States)

    Rostás, I; Tenk, J; Mikó, A; Füredi, N; Soós, S; Solymár, M; Lengyel, A; Székely, M; Gaszner, B; Feller, D; Pétervári, E; Balaskó, M

    2016-12-01

    Leptin is a key catabolic regulator of food intake (FI) and energy expenditure. Both aging and obesity have been shown to induce leptin-resistance. The present study aimed to analyze age-related changes in the anorexigenic and hypermetabolic responsiveness to acute intracerebroventricular leptin administration in different age-groups of normally fed male Wistar rats (adult and old rats from 3 to 24months of age, NF3 to NF24, respectively). The expressions of the long form of the leptin receptor (Ob-Rb) and inhibitory SOCS3 genes were also assessed by quantitative RT-PCR in the arcuate nucleus (ARC). The influence of high-fat diet-induced obesity (HF) on the anorexigenic leptin effects were also tested in younger and older middle-aged groups (HF6 and HF12). Leptin-induced anorexia varied with age: leptin suppressed re-feeding FI (following 48-h fasting) strongly in young adult (NF3), but not in younger or older middle-aged (NF6 or NF12) or in aging (NF18) rats. However, anorexigenic leptin effects reached statistical significance again in old NF24 rats. Leptin-induced hypermetabolism, on the other hand, showed monotonous age-related decline and disappeared by old age. Ob-Rb expression declined until 12months of age followed by a partial recovery in NF18 and NF24 groups. On the other hand, SOCS3 expression was high in NF6 and NF18 and to some extent in NF24 rats. Age-related alterations of Ob-Rb and SOCS3 expression in the ARC may partly contribute to the explanation of age-related variations in anorexigenic but not hypermetabolic leptin effects. High-fat diet-induced obesity was associated with resistance to leptin-induced anorexia in HF6, similar to that seen in NF6. However, instead of the expected leptin-resistance in HF12, a strong leptin-induced suppression of re-feeding was detected in these obese middle-aged rats. Our results suggest that acute central effects of leptin on anorexia and hypermetabolism change in disparate ways during aging, implying separate

  12. [Leptin gene C2549A polymorphism in minority Hui and Uygur children with obesity].

    Science.gov (United States)

    Zhang, Ji-Hong; Zeng, Wen-Juan; Xu, Pei-Ru; Zhang, Wei-Ping

    2014-01-01

    To investigate the relationship of leptin gene polymorphism with obesity in ethnic minority Hui and Uygur children in China. Sixty-eight ethnic minority (35 Hui and 33 Uygur) children with obesity and 69 age-matched minority (36 Hui and 33 Uygur) children without obesity were recruited from six primary schools in the sub-urban areas of Urumqi. Venous blood was sampled from all subjects after fasting for 12 hours. Leptin gene C2549A polymorphism was determined by polymerase chain reaction (PCR) and restriction fragment length polymorphism methods. Blood concentrations of lipids, leptin and insulin were measured with biochemical methods and radioimmunoassys, respectively. In the 137 children tested, the prevalence of AA, AC and CC genotype was 9.5%, 33.6% and 56.9%, respectively. A allele frequency was significantly different between the two ethnic (i.e. Hui and Uygur) groups (P0.05). Blood leptin levels were not significantly different between obese and non-obese children with an AA+AC or CC genotype in both ethnic groups (P>0.05). Leptin gene polymorphisms exist in Hui and Uygur children. The C2549A polymorphism is not significantly associated with the prevalence of obesity in both Hui and Uygur children.

  13. 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

  14. Relation between obesity, lipid profile, leptin and atopic disorders in ...

    African Journals Online (AJOL)

    EL-HAKIM

    count, serum triglycerides and cholesterol, serum leptin (for control group also) and serum total immunoglobulin E (IgE) .... The DSL–10–23100 active Human Leptin ELISA was used. It is an enzymatically amplified 'two .... and the more highly allergenic foods such as eggs, peanuts, tree nuts and fish can be delayed for 2-3.

  15. Obesity and the Ageing Brain: Could Leptin Play a Role in Neurodegeneration?

    Directory of Open Access Journals (Sweden)

    G. H. Doherty

    2011-01-01

    Full Text Available Obesity and ageing are both characteristics of the human population that are on the increase across the globe. It has long been established that ageing is the major risk factor for neurodegenerative conditions such as Alzheimer's disease, and it is becoming increasingly evident that obesity is another such factor. Leptin resistance or insensitivity has been uncovered as a cause of obesity, and in addition the leptin signalling system is less potent in the elderly. Taken together, these findings reveal that this molecule may be a link between neurodegeneration and obesity or ageing. It is now known that leptin has beneficial effects on both the survival and neurophysiology of the neurons that are lost in Alzheimer's disease suggesting that it may be an important research target in the quest for strategies to prevent, halt, or cure this condition.

  16. Leptin, abdominal obesity and onset of depression in older men and women

    Science.gov (United States)

    Milaneschi, Yuri; Simonsick, Eleanor M; Vogelzangs, Nicole; Strotmeyer, Elsa S; Yaffe, Kristine; Harris, Tamara B; Tolea, Magdalena I; Ferrucci, Luigi; Penninx, Brenda W

    2012-01-01

    Objective The mechanisms that underlie the association between abdominal obesity and depression risk in older persons are not well known, but the “leptin hypothesis” of depression suggests that leptin resistance may be involved in mood regulation. We tested whether high circulatory concentration of leptin, alone and in combination with visceral adiposity, is associated with onset of depression in a sample of older persons. Method Participants were 1220 men and 1282 women aged 70–79 years, enrolled in the Health, Aging and Body Composition study. Plasma concentration of leptin and abdominal visceral fat ascertained by computed tomography were assessed at baseline (April 1997 – June 1998). Onset of depression was defined as a Center for Epidemiological Studies-Depression Scale 10-item score ≥ 10 and/or new antidepressant medication use at any annual visit over a 5-year follow-up. Results Higher leptin was associated with the risk of depression onset in men with high visceral fat (HR=1.25,95%CI=1.06–1.46, p=0.01) but not in those with normal visceral fat (HR=0.98,95%CI=0.80–1.19, p=0.80) (leptin*visceral fat p=0.04). No interaction between leptin and visceral fat was detected in the analysis focusing on women (p=0.90). Conclusion In older men, high leptin was associated with an increased onset of depressive symptoms especially in the presence of abdominal obesity, suggesting that underlying leptin resistance may play a role in this link. Differences in visceral fat levels and metabolic consequences may explain the absence of this association in women. These findings suggest a potential biological link between depression, obesity and their joint association with negative health outcomes. PMID:22687702

  17. Leptin, abdominal obesity, and onset of depression in older men and women.

    Science.gov (United States)

    Milaneschi, Yuri; Simonsick, Eleanor M; Vogelzangs, Nicole; Strotmeyer, Elsa S; Yaffe, Kristine; Harris, Tamara B; Tolea, Magdalena I; Ferrucci, Luigi; Penninx, Brenda W J H

    2012-09-01

    The mechanisms that underlie the association between abdominal obesity and depression risk in older persons are not well known, but the "leptin hypothesis" of depression suggests that leptin resistance may be involved in mood regulation. We tested whether high circulatory concentration of leptin, alone and in combination with visceral adiposity, is associated with onset of depression in a sample of older persons. Participants were 1,220 men and 1,282 women aged 70-79 years and enrolled in the Health, Aging, and Body Composition study. Serum concentration of leptin and abdominal visceral fat, ascertained by computed tomography, were assessed at baseline (April 1997-June 1998). Onset of depression, the primary outcome measure, was defined as a Center for Epidemiologic Studies-depression scale 10-item score ≥ 10 and/or new antidepressant medication use at any annual visit over a 5-year follow-up. Higher leptin level was associated with the risk of depression onset in men with high levels of visceral fat (hazard ratio [HR] = 1.25; 95% CI, 1.06-1.46; P = .01) but not in those with normal visceral fat (HR = 0.98; 95% CI, 0.80-1.19; P = .80) (leptin-by-visceral fat, P = .04). No interaction between leptin and visceral fat was detected in the analysis focusing on women (P = .90). In older men, high leptin level was associated with an increased onset of depressive symptoms, especially in the presence of abdominal obesity, suggesting that underlying leptin resistance may play a role in this link. Differences in visceral fat levels and metabolic consequences may explain the absence of this association in women. These findings suggest a potential biological link between depression, obesity, and their joint association with negative health outcomes. © Copyright 2012 Physicians Postgraduate Press, Inc.

  18. Effects of dopamine on leptin release and leptin gene (OB expression in adipocytes from obese and hypertensive patients

    Directory of Open Access Journals (Sweden)

    Alvarez-Aguilar C

    2013-11-01

    Full Text Available Cleto Alvarez-Aguilar,1–3 Alfonso Rafael Alvarez-Paredes,2 Bengt Lindholm,4 Peter Stenvinkel,4 Elvia García-López,4 Oliva Mejía-Rodríguez,5 Joel Edmundo López-Meza,6 Dante Amato,7 Ramon Paniagua8 1Hospital General Regional N°1, Instituto Mexicano del Seguro Social (IMSS, Morelia, 2Facultad de Ciencias Médicas y Biológicas "Dr. Ignacio Chávez" Universidad Michoacana de San Nicolás de Hidalgo (UMSNH, Morelia, Michoacán, 3División de Estudios Superiores, Universidad Nacional Autónoma de México (UNAM, México DF, México; 4Department of Clinical Science Intervention and Technology, Karolinska Institutet, Stockholm, Sweden; 5Coordinación Delegacional de Investigación en Salud, IMSS, Morelia, 6Centro Multidisciplinario de Estudios en Biotecnología (CMEB, UMSNH, Morelia, Michoacán, 7Facultad de Estudios Superiores Iztacala, UNAM, Tlalnepantla, 8Unidad de Investigación en Enfermedades Nefrológicas, Hospital de Especialidades, CMN Siglo XXI, IMSS, México DF, México Background: A reduction of dopaminergic (DAergic activity with increased prolactin levels has been found in obese and hypertensive patients, suggesting its involvement as a pathophysiological mechanism promoting hypertension. Similarly, leptin action increasing sympathetic activity has been proposed to be involved in mechanisms of hypertension. The aim of this study was to analyze the effects of DA, norepinephrine (NE, and prolactin on leptin release and leptin gene (OB expression in adipocytes from obese and hypertensive patients. Methods: Leptin release and OB gene expression were analyzed in cultured adipocytes from 16 obese and hypertensive patients treated with DA (0.001, 0.01, 0.1, and 1.0 µmol/L, NE (1.0 µmol/L, insulin (0.1 µmol/L, and prolactin (1.0 µmol/L, and from five nonobese and normotensive controls treated with DA (1 µmol/L, NE (1 µmol/L, insulin (0.1 µmol/L, and prolactin (1.0 µmol/L. Results: A dose-related reduction of leptin release and OB

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

    Science.gov (United States)

    Altintas, Mehmet M; Nayer, Behzad; Walford, Eric C; Johnson, Kevin B; Gaidosh, Gabriel; Reiser, Jochen; De La Cruz-Munoz, Nestor; Ortega, Luis M; Nayer, Ali

    2012-02-07

    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. 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 noted between ob/ob and control mice. This study

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

    Directory of Open Access Journals (Sweden)

    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

  1. Changes of serum leptin, adiponection and insulin levels in females with simple obesity

    International Nuclear Information System (INIS)

    Wei Tao; Duan Wennuo; Ma Yongxiu; Chen Yanping

    2004-01-01

    Objective: To study the changes of serum leptin, insulin and adiponectin levels and their relationship with BMI in females with simple obesity. Methods: Serum leptin, adiponectin and insulin levels were measured with RIA in 48 pre-obese females (BMI=23-24.9 kg/m 2 ), 40 females with simple obesity, (BMI≥25 kg/m 2 ) and 42 female controls (BMI 18-22.9 kg/m 2 ). Correlations among these variables were studied. Results: Serum leptin, insulin levels were significantly higher and serum adiponectin levels were significantly lower in both the pre-obese and obese females than those in controls. Serum leptin, insulin levels were positively correlated to BMI; Serum adiponectin levels were negatively correlated to BMI. Conclusion: Within normal range of BMI, the leptin-insulin feedback mechanism provided satisfactory self-regulation. However, with excessive BMI, this dynamic equilibrium would be disrupted. The defective equilibrium, together with the abnormal low adiponectin level, would predispose to the development of diabetes mellitus. (authors)

  2. Leptin enhances NR2B-mediated N-methyl-D-aspartate responses via a mitogen-activated protein kinase-dependent process in cerebellar granule cells.

    Science.gov (United States)

    Irving, A J; Wallace, L; Durakoglugil, D; Harvey, J

    2006-01-01

    It is well documented that the hormone leptin regulates energy balance via its actions in the hypothalamus. However, evidence is accumulating that leptin plays a key role in numerous CNS functions. Indeed, leptin receptors are expressed in many extrahypothalamic brain regions, with high levels found in the hippocampus and cerebellum. In the hippocampus leptin has been shown to facilitate N-methyl-D-aspartate receptor function and modulate synaptic plasticity. A role for leptin in cerebellar function is also indicated as leptin-deficient rodents display reduced mobility that is unrelated to obesity. Here we show that leptin receptor immunolabeling can be detected in cultured cerebellar granule cells, being expressed at the somatic plasma membrane and also concentrated at synapses. Furthermore, leptin facilitated NR2B N-methyl-D-aspartate receptor-mediated Ca2+ influx in cerebellar granule cells via a mitogen-activated protein kinase-dependent pathway. These findings provide the first direct evidence for a cellular action of leptin in cerebellar neurons. In addition, given that N-methyl-D-aspartate receptor activity in the cerebellum is crucial for normal locomotor function, these data also have important implications for the potential role of leptin in the control of movement.

  3. Relationship and significance of serum leptin with blood insulin and lipid in 6-13 years old obese children

    International Nuclear Information System (INIS)

    Sheng Chunyong; Wang Chunlan; Zhang Linong

    2005-01-01

    To explore relationship and significance of Serum Leptin with BMI, Insulin, triglyceride (TG) and total cholesterol (TC) in obese children aged 6-13 years. Serum Leptin of school-age children 118 (64 male, 54 female; normal non-obese 56 and obese 62) were deter- mined and compared with BMI, Insulin, TG and TC. The results showed that: (1) Each index of obese children was remarkably higher than that of non-obese children (P 0.05). (3) Leptin was poritinely corelation with BMI, insulin, TG and TC(P=0.001). Leptin level in serum may varied according to sex, BMI or blood lipid level. It is of great significance in prevention and treatment of obesity to use drug which may improve Leptin receptor effect. (authors)

  4. Influence of the core circadian gene "Clock" on obesity and leptin resistance in mice.

    Science.gov (United States)

    Xie, Xiaoping; Yang, Shuhong; Zou, Yan; Cheng, Shuting; Wang, Yuhui; Jiang, Zhou; Xiao, Jing; Wang, Zhengrong; Liu, Yanyou

    2013-01-23

    Alterations in metabolism could be due to cell-autonomous effects associated with altered expression of Clock in central nervous system feeding centers and/or peripheral tissues involved in metabolism. Clock mutant mice are hyperphagic and obese, which indicates that Clock is related to obesity. In the present study, we used intracerebroventricular injection of recombinant adenoviral vector harboring Clock genes to explore the role of Clock on diet induced obesity and the mechanisms involved in leptin resistance and leptin signaling in mice. The results demonstrated that expression of Clock in the arcuate nucleus of diet induced obesity mice was down-regulated. The recombinant adenoviral vector harboring Clock genes could reduce obesity indexes of diet induced obesity mice including body weight, BMI and total fat mass, attenuate hyperleptinemia, increase leptin sensitivity and decrease accumulated suppressor of cytokine signaling-3 in the arcuate nucleus. These results indicate that Clock plays an important role on obesity, which may be involved in leptin resistance and regulation of suppressor of cytokine signaling-3 in arcuate nucleus. Copyright © 2012 Elsevier B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. Leptin as an important link between obesity and cardiovascular risk factors in men with acute myocardial infarction.

    Science.gov (United States)

    Ekmen, Nergis; Helvaci, Aysen; Gunaldi, Meral; Sasani, Hadi; Yildirmak, Sembol Turkmen

    2016-01-01

    The levels of leptin, a major regulator of lipid metabolism, may increase in obesity, and contribute to the development of metabolic syndrome. Leptin is produced by adipose tissue and is a peptide hormone, which has strong association with obesity, elevated cardiovascular risk, and morbidity. The present study was designed to evaluate the relationships between leptin levels, obesity, and cardiovascular risk factors in men with acute myocardial infarction. Twenty-four obese and twenty-three nonobese male patients, who had experienced their first myocardial infarction, were included in the study. Their leptin levels, biochemical parameters, and anthropometric measures were obtained. Mean leptin levels were significantly higher in the obese group compared to the nonobese group (2.53ng/mL versus 1.23ng/mL; pobesity and diastolic blood pressure in male patients with myocardial infarction. Copyright © 2015 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

  7. Leptin-to-Adiponectin Ratio is Related to Low Grade Inflammation and Insulin Resistance Independent of Obesity in Non-Diabetic Taiwanese: A Cross-Sectional Cohort Study

    Science.gov (United States)

    Chou, Hsin-Hua; Hsu, Lung-An; Wu, Semon; Teng, Ming-Sheng; Sun, Yu-Chen; Ko, Yu-Lin

    2014-01-01

    Background Leptin and adiponectin are secreted from adipose tissue and exert opposing effects on C-reactive protein (CRP) levels and insulin resistance. As hypertrophic adipocytes secrete more leptin and less adiponectin, the leptin-to adiponectin ratio (LAR) has been proposed as a useful measure of insulin resistance and vascular risk. We investigated whether LAR may serve as a better predictor than either leptin or adiponectin alone for low-grade inflammation and insulin resistance independent of obesity in a non-diabetic Taiwanese population. Methods This study included 568 non-diabetic Taiwanese individuals (297 men, 271 women). CRP, leptin and adiponectin were measured using enzyme-linked immunosorbent assay. The degree of insulin resistance was determined using the homeostasis model assessment of insulin resistance (HOMA-IR). Results In the receiver operator characteristic analysis, the area under the curve of LAR in predicting individuals with elevated CRP and insulin resistance was significantly greater than that for either leptin (p = 0.0035 vs. elevated CRP, p HOMA-IR index (p HOMA-IR are greater than the association with leptin or adiponectin alone. PMID:27122790

  8. Clinical significance of determination of changes of serum leptin and E2 levels in females children with simple obesity

    International Nuclear Information System (INIS)

    Bai Hua; Qian Mingzhu

    2007-01-01

    Objective: To investigate the clinical significance of changes of serum leptin and E 2 levels in females children with simple obesity. Methods: Serum levels of leptin and E 2 were detected with RIA in 32 females children with simple obesity and 35 controls. Results: In the children with simple obesity the serum leptin and E 2 levels were significantly higher than those in controls (P 2 levels is of help for judgement of severity of obesity as well as outcome prediction in female children. (authors)

  9. Relation between plasma leptin and anthropometric and metabolic covariates in lean and obese diabetic and hyperlipidaemic Asian Northern Indian subjects.

    Science.gov (United States)

    Misra, A; Arora, N; Mondal, S; Pandey, R M; Jailkhani, B; Peshin, S; Chaudhary, D; Saluja, T; Singh, P; Chandna, S; Luthra, K; Vikram, N K

    2001-02-01

    This study investigated the relationship of plasma leptin to obesity, diabetes and hyperlipidaemia in Asian Northern Indian subjects, considered to have a predisposition to abdominal obesity and metabolic syndrome. A total of 72 subjects, subcategorised into lean and obese healthy subjects, lean and obese Type 2 diabetic and lean and obese non-diabetic hyperlipidaemic subjects were recruited. High leptin values were observed in all obese groups, and obese diabetic patients showed the highest levels. In lean and obese diabetic subjects, plasma leptin did not show any correlation to any index of glycaemia. When all lean and all obese subjects were analysed in two separate groups, body mass index (BMI), percent total body fat, and body density significantly correlated with the plasma leptin levels (p<0.05). Leptin values, when correlated to all variables in all patients taken together, showed the greatest magnitude of correlation with BMI (r=0.64), percent total body fat (r=0.67), and waist circumference (r=0.51). Strong inverse correlation was seen with body density (r=-0.67). Levels of serum insulin did not show any correlation with leptin levels in all subjects combined, and separately in various groups. Multiple linear regression analysis performed in obese, non-diabetic and normolipidaemic subjects, all Type 2 diabetic and all non-diabetic hyperlipidaemic subjects separately showed that percent total body fat is the only significant predictor of plasma leptin concentration in all the 3 groups. The present study suggests that plasma leptin has a strong positive correlation with percent total body fat in Asian Northern Indian subjects. Among other components of metabolic syndrome, only abdominal obesity is weakly correlated to serum leptin levels.

  10. Correlations of serum levels of leptin and other related factor (NPY, ADP) in female children with simple obesity

    International Nuclear Information System (INIS)

    Bai Hua; Wei Chunlei; Qian Mingzhu

    2008-01-01

    Objective: To study the changes of serum levels of leptin, NPY and ADP in female children with simple obesity. Methods: Serum levels of leptin, NPY and ADP were measured with radioimmunoassay (RIA) in 32 female children with simple obesity and 35 controls. Results: The serum levels of leptin, NPY were significantly higher in the obese children than those in controls (P<0.01), while the serum levels of ADP were significantly lower (P<0.01). Serum leptin levels were significantly positively correlated (r=0.6014, P<0.01) with NPY levels but were negatively correlated (r=-0.4786, P<0.01) with adiponectin (ADP) levels. Conclusion: Determination of serum leptin, NPY and ADP levels is of help for judgement of degree of obesity as wen as outcome prediction in female children. (authors)

  11. The cellular and molecular bases of leptin and ghrelin resistance in obesity.

    Science.gov (United States)

    Cui, Huxing; López, Miguel; Rahmouni, Kamal

    2017-06-01

    Obesity, a major risk factor for the development of diabetes mellitus, cardiovascular diseases and certain types of cancer, arises from a chronic positive energy balance that is often due to unlimited access to food and an increasingly sedentary lifestyle on the background of a genetic and epigenetic vulnerability. Our understanding of the humoral and neuronal systems that mediate the control of energy homeostasis has improved dramatically in the past few decades. However, our ability to develop effective strategies to slow the current epidemic of obesity has been hampered, largely owing to the limited knowledge of the mechanisms underlying resistance to the action of metabolic hormones such as leptin and ghrelin. The development of resistance to leptin and ghrelin, hormones that are crucial for the neuroendocrine control of energy homeostasis, is a hallmark of obesity. Intensive research over the past several years has yielded tremendous progress in our understanding of the cellular pathways that disrupt the action of leptin and ghrelin. In this Review, we discuss the molecular mechanisms underpinning resistance to leptin and ghrelin and how they can be exploited as targets for pharmacological management of obesity.

  12. Study of Serum Levels of Leptin, C-Reactive Protein and Nutritional Status in Hemodialysis Patients.

    Science.gov (United States)

    Montazerifar, Farzaneh; Karajibani, Mansour; Hassanpour, Zahra; Pourmofatteh, Mahla

    2015-08-01

    Leptin is secreted by adipose tissue and decreases appetite. However, the role of leptin in the pathogenesis of hemodialysis (HD)-related malnutrition has not been fully evaluated. The aim of study was to investigate the association between the serum leptin levels, serum C-reactive protein (CRP) levels, and nutritional status in hemodialysis patients. This analytical descriptive study included 45 hemodialysis patients and 40 healthy subjects. Biochemical parameters and serum leptin levels were measured. The nutritional status was evaluated using a food frequency questionnaire (FFQ) and the calculation of the body mass index (BMI). Serum leptin (P nutritional factors in hemodialysis patients.

  13. Obesity is associated with increased seminal insulin and leptin alongside reduced fertility parameters in a controlled male cohort.

    Science.gov (United States)

    Leisegang, Kristian; Bouic, Patrick J D; Menkveld, Roelof; Henkel, Ralf R

    2014-05-07

    Obesity appears to be associated with male reproductive dysfunction and infertility, although this has been inconsistent and inconclusive. Insulin and leptin are known mediators and modulators of the hypothalamus-pituitary-testes axis, contributing to the regulation of male reproductive potential and overall wellbeing. These hormones are also present in semen influencing sperm functions. Although abdominal obesity is closely associated with insulin resistance (hyperinsulinaemia), hyperleptinaemia and glucose dysfunction, changes in seminal plasma concentrations of insulin, leptin and glucose in obese males has not previously been investigated. This small case controlled study assessed serum and seminal concentrations of insulin, leptin and glucose in obese (BMI > =30; n = 23) and non-obese (BMI Obesity was associated with increased serum and seminal insulin and leptin, with no significant difference in seminal glucose. Serum and seminal concentrations of insulin and leptin were positively correlated. Furthermore, obesity was associated with decreased sperm concentration, sperm vitality and increased MMP and DF, with a non-significant impact on motility and morphology. Hyperinsulinaemia and hyperleptinaemia are associated with increased seminal insulin and leptin concentrations, which may negatively impact male reproductive function in obesity. Insulin was also found to be highly concentrated in the seminal plasma of both groups. This data will contribute to the contradictive information available in the literature on the impact of obesity and male reproduction.

  14. Daily rhythms of plasma melatonin, but not plasma leptin or leptin mRNA, vary between lean, obese and type 2 diabetic men.

    Directory of Open Access Journals (Sweden)

    Simone Mäntele

    Full Text Available Melatonin and leptin exhibit daily rhythms that may contribute towards changes in metabolic physiology. It remains unclear, however, whether this rhythmicity is altered in obesity or type 2 diabetes (T2DM. We tested the hypothesis that 24-hour profiles of melatonin, leptin and leptin mRNA are altered by metabolic status in laboratory conditions. Men between 45-65 years old were recruited into lean, obese-non-diabetic or obese-T2DM groups. Volunteers followed strict sleep-wake and dietary regimes for 1 week before the laboratory study. They were then maintained in controlled light-dark conditions, semi-recumbent posture and fed hourly iso-energetic drinks during wake periods. Hourly blood samples were collected for hormone analysis. Subcutaneous adipose biopsies were collected 6-hourly for gene expression analysis. Although there was no effect of subject group on the timing of dim light melatonin onset (DLMO, nocturnal plasma melatonin concentration was significantly higher in obese-non-diabetic subjects compared to weight-matched T2DM subjects (p<0.01 and lean controls (p<0.05. Two T2DM subjects failed to produce any detectable melatonin, although did exhibit plasma cortisol rhythms comparable to others in the group. Consistent with the literature, there was a significant (p<0.001 effect of subject group on absolute plasma leptin concentration and, when expressed relative to an individual's 24-hour mean, plasma leptin showed significant (p<0.001 diurnal variation. However, there was no difference in amplitude or timing of leptin rhythms between experimental groups. There was also no significant effect of time on leptin mRNA expression. Despite an overall effect (p<0.05 of experimental group, post-hoc analysis revealed no significant pair-wise effects of group on leptin mRNA expression. Altered plasma melatonin rhythms in weight-matched T2DM and non-diabetic individuals supports a possible role of melatonin in T2DM aetiology. However, neither

  15. Obesity as risk factor and study of obesity related proteins in ...

    African Journals Online (AJOL)

    Elevated serum leptin level was associated with components of the metabolic syndrome, including increased body-mass index, waist-to-hip ratio, serum triglyceride levels, fasting blood sugar, glyacated HbA1c, total serum proteins and decreased high-density lipoprotein cholesterol levels in obese diabetes as compared to ...

  16. Serum Leptin and Adiponectin Levels in Obese and Nonobese Asthmatic School Children in relation to Asthma Control

    Directory of Open Access Journals (Sweden)

    Atqah Abdul Wahab

    2013-01-01

    Full Text Available There is growing evidence of a positive correlation between asthma and obesity in children and adults. Leptin and adiponectin regulate several metabolic and inflammatory functions. This study aims to evaluate serum leptin and adiponectin concentrations in asthmatic school children to investigate their association with obesity and the degree of asthma control. Obese asthmatic (OA and nonobese asthmatic (NOA children, aged 7 to 14, were randomly enrolled in this prospective study. Data on demographic, anthropometric, serum lipids, and spirometric measures and allergy status were collected and analyzed. Serum leptin was significantly higher (25.8±11.1 versus 8.7±11.1; P<0.0001 and adiponectin levels were lower (2.5±1.2 versus 5.4±2.9; P<0.0001 in OA compared to NOA children. The uncontrolled group had higher leptin and lower adiponectin levels compared to well and partially controlled asthma. BMI was positively correlated with leptin (r=0.79; P<0.001 and negatively with adiponectin (r=-0.73; P<0.001. Mean BMI and leptin levels were observed to be higher in girls compared to boys. Stepwise multiple linear regression analysis showed that higher BMI and female gender had significant effect on serum leptin levels. Among asthmatic children higher serum leptin and lower adiponectin levels were significantly associated with obesity and showed no significant association with degree of asthma controls.

  17. Association of serum leptin with serum C-reactive protein in hemodialysis patients

    Directory of Open Access Journals (Sweden)

    Rastegari Ebrahim

    2012-04-01

    Full Text Available Introduction: Recent investigations have shown that leptin is cleared principally by the kidney. Objectives: To examine whether and how in patients on hemodialysis the level of C-reactive protein level correlate with serum leptin. Patients and Methods: The total patients were 36. The mean patients’ age were 46 (16 years. The median length of the time patients were on hemodialysis were 19 months. Results: The mean serum C-reactive protein was 8.7 (6.6 mg/l (median: 8 mg/l. The mean serum leptin was 9.4 (14 ng/ml (median: 5.75 ng/ml. In this study we found a significant inverse correlation of serum leptin with serum C-reactive protein (r= -0.57, p= 0.041 was seen. Conclusion: Our data supports, the positive effect of leptin on nutrition and support the theory of protective effects (reverse epidemiology of leptin in hemodialysis patients.

  18. Changes of serum leptin and their relationships with insulin resistance in patients with simple obesity and patients with type 2 diabetes mellitus complicated with obesity

    International Nuclear Information System (INIS)

    Zhang Lei; Changzhou Wujin People's Hospital of Jiangsu Province, Changzhou; Shi Linlin; Lu Dan; Zhang Lei; Wang Qing; Yao Wenhua

    2005-01-01

    Objective: To study the changes of serum leptin in patients with simple obesity and patients with type 2 diabetes mellitus complicated with obesity in order to explore the relationship of leptin and insulin resistance and the role of leptin in the occurrence of type 2 diabetes mellitus. Methods: 60 cases of simple obesity, 60 cases of type 2 diabetes mellitus and 30 cases of normal control were included according to the diagnostic criteria of obesity and type 2 diabetes mellitus. the levels of fasting serum leptin, fasting serum insulin, fasting glucose, fasting blood lipid were measured in all cases. The body mass index (BMI) and insulin action index were calculated. Results: The level of BMI, serum leptin, serum insulin, blood lipid were significantly higher in patients with simple obesity and with type 2 diabetes mellitus complicated with obesity than in normal control cases, while (IAI) was significantly lower. The levels of free serum leptin, serum insulin, free glucose, and blood lipid were significantly higher in patients with type 2 diabetes mellitus complicated with obesity than in patients with simple obesity, while IAI was significantly lower. The level of serum leptin was positively correlated with BMI (r=0.48, P<0.55) and fasting serum leptin (r=0.55, P<0.05) and negatively correlated with IAI (r=-0.47, P<0.05) in patients with type 2 diabetes complicated with obesity. Conclusion: The overexpression of serum leptin may play an important role in the occurrence of the insulin resistance and type 2 diabetes mellitus in obesity patients. (authors)

  19. Male fertility and obesity: are ghrelin, leptin and glucagon-like peptide-1 pharmacologically relevant?

    Science.gov (United States)

    Alves, Marco G; Jesus, Tito T; Sousa, Mário; Goldberg, Erwin; Silva, Branca M; Oliveira, Pedro F

    2016-01-01

    Obesity is rising to unprecedented numbers, affecting a growing number of children, adolescents and young adult men. These individuals face innumerous health problems, including subfertility or even infertility. Overweight and obese men present severe alterations in their body composition and hormonal profile, particularly in ghrelin, leptin and glucagon-like peptide-1 (GLP-1) levels. It is well known that male reproductive health is under the control of the individual's nutritional status and also of a tight network of regulatory signals, particularly hormonal signaling. However, few studies have been focused on the effects of ghrelin, leptin and GLP-1 in male reproduction and how energy homeostasis and male reproductive function are linked. These hormones regulate body glucose homeostasis and several studies suggest that they can serve as targets for anti-obesity drugs. In recent years, our understanding of the mechanisms of action of these hormones has grown significantly. Curiously, their effect on male reproductive potential, that is highly dependent of the metabolic cooperation established between testicular cells, remains a matter of debate. Herein, we review general concepts of male fertility and obesity, with a special focus on the effects of ghrelin, leptin and GLP-1 on male reproductive health. We also discuss the possible pharmacological relevance of these hormones to counteract the fertility problems that overweight and obese men face.

  20. Leptin activates oxytocin neurons of the hypothalamic paraventricular nucleus in both control and diet-induced obese rodents.

    Directory of Open Access Journals (Sweden)

    Mario Perello

    Full Text Available The adipocyte-derived hormone leptin acts in the brain to reduce body weight and fat mass. Recent studies suggest that parvocellular oxytocin (OXT neurons of the hypothalamic paraventricular nucleus (PVN can mediate body weight reduction through inhibition of food intake and increased energy expenditure. However, the role of OXT neurons of the PVN as a primary target of leptin has not been investigated. Here, we studied the potential role of OXT neurons of the PVN in leptin-mediated effects on body weight regulation in fasted rats. We demonstrated that intracerebroventricular (ICV leptin activates STAT3 phosphorylation in OXT neurons of the PVN, showed that this occurs in a subpopulation of OXT neurons that innervate the nucleus of the solitary tract (NTS, and provided further evidence suggesting a role of OXT to mediate leptin's actions on body weight. In addition, our results indicated that OXT neurons are responsive to ICV leptin and mediate leptin effects on body weight in diet induced obese (DIO rats, which are resistant to the anorectic effects of the hormone. Thus, we conclude that leptin targets a specific subpopulation of parvocellular OXT neurons of the PVN, and that this action may be important for leptin's ability to reduce body weight in both control and obese rats.

  1. The changes of serum leptin and insulin contents in elderly male patients with obesity-related hypertension

    International Nuclear Information System (INIS)

    Zhan Hao; Huang Daijuan; Yuan Bin; He Yong; Zhang Yongxue

    2004-01-01

    To study the contents of serum leptin and insulin in elderly male patients with obesity-related hypertension, the levels of serum leptin and insulin in 21 normotensive cases and 41 hypertensive cases of them were determined by RIA. The results showed that the levels of serum leptin and insulin between hypertensives and normotensives in the non-obese groups were not significantly different (P>0.05). Compared with normotensives, the levels of serum leptin and insulin of hypertensives in the obese groups remarkably increased 1.8μg/L and 2.7 mIU/L respectively (P<0.01). The levels of serum leptin and insulin in the patients with obesity - related hypertension were markedly higher than those in the patients with non-obesity-related hypertension and elevated 2.7μg/L and 4.7mIU/L (P<0.01) respectively. Insulin-sensitivity index (ISI) successively decreased in the groups of HBPOb, NBPOb, HBPNOb and NBPNOb (relative ISI 0.50, 0.68, 0.92, 1 respectively). It is concluded that leptin-resistance and insulin-resistance exist in male elderly patients with obesity-related hypertension

  2. The relationship between obesity, leptin, adiponectin and the ...

    African Journals Online (AJOL)

    Objectives: Obesity prevalence is increasing worldwide. In South Africa, older and urbanised African women have significantly higher rates of obesity. Limited information is available on the relationship between anthropometric parameters, adipokines and metabolic health status of African women. This study investigated the ...

  3. Relationship between obesity and leptin serum among low socioeconomic primary school children aged 5-7 years

    Directory of Open Access Journals (Sweden)

    Soenarto Soenarto

    2010-06-01

    Full Text Available Background Obesity has become a major health problem globally, indicates as an epidemic problem by World Health Organization (WHO. Adiposity rebound period may represent critical period for the development of adiposity. Recent data suggest that, in industrialized countries, people of low socioeconomic group are more likely to be obese than their high socioeconomic counterparts. Level of serum leptin was reported to be higher in obese subjects. There has been lack of data regarding leptin serum level in Indonesian obese children. Objective This study aimed to investigate leptin serum level in low socioeconomic obese children.  Methods This was a cross sectional study perfonned in Tuminting District, Manado. Obesity was defined based on body mass index for AsiaPacific condition, i.e., grade I obesity (BMI 25/29.9 kg/ mL, grade II (BM] 30-40 kg/ml, and grade III (BM] > 40 kg/m2 Low socioeconomic status was detennined based on Government's program Cash Direct Aid Program. loBod sample was obtained from inclusion subjects, consisted of leptin serum. Results Fiftytwo low socioeconomic obese children were eligible \\\\lith age ranged between 5 to 7 years. They were divided into grade ] obesity (43 or 82.7%, and grade II (9 or 17.3%. The lowest leptin blood level was 10,291 pg/mL, while the highest was 41,500 pg/dL. All girls had nonnal serum leptin level; in contrast all boys had increased serum leptin level.  Conclusions Leprin level increased in those subjects whose BMI increased.

  4. Comparitive Study of Serum Leptin Levels in Diabetic Obese Patients and Non-Diabetic Obese Individuals

    OpenAIRE

    M Afkhami-Ardakani; J Mohiti-Ardakani; H Sedghi

    2004-01-01

    Introduction: Leptin was first discovered from the "Ob Gene" by Friedwan and co-workers in 1994. It is a small peptide with 167 amino acids and molecular weight of 16 Kd . It is secreted by adipose tissues. Leptin has two type of receptors in Hypothalamus and other tissues including muscles, liver and intestines. Leptin inhibits neuropeptide Y resulting in decreased appetite and on the other hand increases the basic metabolic rate of the body resulting in homeostasis of body energy. Insulin v...

  5. The Effect of Eight Weeks Resistance Training on Leptin and Insulin Resistance in Obese Female

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    S. Khalili

    2013-04-01

    Full Text Available Introduction & Objective: Leptin , the main peptide secreted by adipose tissue, is considered an alarming factor in the regulation of body fat content . With regard to the physiological effect of exercise as one of the potential regulators of leptin secretion from adipose tissue , this study was performed to examine the effects of resistance exercise on leptin. Materials & Methods: Twenty inactive and obese female students (10 controls and 10 experi-mentals participated in this study. The subjects in the experimental group performed an 8 week resistance training program (chest press, leg press, lat pull down, leg curl, bicep curl, leg extension with 60 - 70 percent of 1RM. ELISA was used to measure leptin. Results: The results of this study showed that 8 weeks of resistance training significantly decreased BMI (31.32 kg/m2 versus 29.73 kg/m2 , P=0.0001, weight body (80.5kg versus 76.25kg, P=0.0001, WHR (0.93 ver-sus0.89, P=0.0001 and body fat percent (27.48 versus 24.85, P=0.0001 in EG. Statistically significant differ-ences were not seen in leptin (P=0.939, insulin (P=0.336, glucose (P=0.264 and insulin resistance (P=0.306 between CG and EG. Conclusion: The results of this study showed that , there was no significant difference in leptin levels and insulin resistance between the control and experimental groups, after 8 weeks of resistance training. (Sci J Hamadan Univ Med Sci 2013; 20 (1:59-65

  6. The cerebrospinal fluid/serum leptin ratio during pharmacological therapy for obesity.

    Science.gov (United States)

    Rodrigues, Adriane Maria; Radominski, Rosana Bento; Suplicy, Henrique de Lacerda; De Almeida, Sergio Monteiro; Niclewicz, Patricia Artigas; Boguszewski, Cesar Luiz

    2002-04-01

    The aim of the present study was to evaluate the cerebrospinal fluid (CSF)/serum leptin ratio during pharmacological therapy for obesity with centrally and peripherally acting drugs. Thirty-one obese women (mean age, 32.3 +/- 10 yr; body mass index, 38.2 +/- 5.2 kg/m(2); body fat, 43.3 +/- 5.4%) were studied before and 2 months after a weight loss program consisting of a balanced diet (1200 kcal/d) plus drug therapy. The patients were randomly assigned into three study groups: group I, fenproporex 25 mg/d (n = 10); group II, sibutramine 10 mg/d (n = 10); and group III, orlistat 120 mg tid (n = 11). Body fat, measured by dual-energy x-ray absorptiometry, and serum and CSF concentrations of leptin were examined at baseline and 2 months after therapy. At baseline, clinical and biochemical characteristics of the groups were similar. All of the women lost weight, approximately 7.0% of their initial body weight, and the reduction was not different among the groups. Serum leptin fell significantly after 2 months in all groups, and the decline was proportional to the reduction in body fat, because leptin levels adjusted for body fat did not change after treatment. CSF leptin levels showed a significant decrease after 2 months in all groups, and this decline was higher on group III compared with group I (P = 0.006). After therapy, the CSF/serum leptin ratio did not change in group I (1.57 +/- 0.3 to 1.72 +/- 0.62%) and group II (1.78 +/- 1.01 to 1.69 +/- 1.27%), whereas it declined significantly in group III (1.65 +/- 0.43 to 1.09 +/- 0.47%; P obese women treated during 2 months with orlistat, whereas this ratio did not change in this period of time in obese women treated with fenproporex and sibutramine.

  7. Mechanism of protein tyrosine phosphatase 1B-mediated inhibition of leptin signalling

    DEFF Research Database (Denmark)

    Lund, I K; Hansen, J A; Andersen, H S

    2005-01-01

    Upon leptin binding, the leptin receptor is activated, leading to stimulation of the JAK/STAT signal transduction cascade. The transient character of the tyrosine phosphorylation of JAK2 and STAT3 suggests the involvement of protein tyrosine phosphatases (PTPs) as negative regulators of this sign...

  8. Prenatal programming of postnatal obesity: fetal nutrition and the regulation of leptin synthesis and secretion before birth.

    Science.gov (United States)

    McMillen, I C; Muhlhausler, B S; Duffield, J A; Yuen, B S J

    2004-08-01

    Exposure to either an increased or decreased level of intrauterine nutrition can result in an increase in adiposity and in circulating leptin concentrations in later life. In animals such as the sheep and pig in which fat is deposited before birth, leptin is synthesised in fetal adipose tissue and is present in the fetal circulation throughout late gestation. In the sheep a moderate increase or decrease in the level of maternal nutrition does not alter fetal plasma leptin concentrations, but there is evidence that chronic fetal hyperglycaemia and hyperinsulinaemia increase fetal fat mass and leptin synthesis within fetal fat depots. Importantly, there is a positive relationship between the relative mass of the 'unilocular' component of fetal perirenal and interscapular adipose tissue and circulating fetal leptin concentrations in the sheep. Thus, as in the neonate and adult, circulating leptin concentrations may be a signal of fat mass in fetal life. There is also evidence that leptin can act to regulate the lipid storage, leptin synthetic capacity and potential thermogenic functions of fat before birth. Thus, leptin may act as a signal of energy supply and have a 'lipostatic' role before birth. Future studies are clearly required to determine whether the intrauterine and early postnatal nutrient environment programme the endocrine feedback loop between adipose tissue and the central and peripheral neuroendocrine systems that regulate energy balance, resulting in an enhanced risk of obesity in adult life.

  9. Role of leptin during childhood growth and development.

    Science.gov (United States)

    Roemmich, J N; Rogol, A D

    1999-12-01

    Leptin, the product of the ob/ob gene in rodents, regulates energy balance and fertility. Two genetic models, the ob/ob mouse (deletion of leptin protein) and the db/db mouse (deletion of leptin receptor) have markedly augmented research in obesity. Human obesity is more closely linked to leptin resistance than to the absence of leptin. Serum leptin concentrations reflect the size of the subcutaneous fat depot better than total fat mass or abdominal visceral fat. At the initiation of puberty there is a divergence in circulating leptin concentrations between boys and girls. In boys, leptin concentrations increase and then markedly decrease to prepubertal concentration levels. In girls there are only increasing concentrations. The authors believe these patterns are relevant to the markedly different alterations in the regional distribution of body fat that occurs in boys and girls at puberty.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Leptin level and oxidative stress contribute to obesity-induced low testosterone in murine testicular tissue.

    Science.gov (United States)

    Zhao, Jian; Zhai, Lingling; Liu, Zheng; Wu, Shuang; Xu, Liping

    2014-01-01

    This study evaluated the effects of obesity on the function of reproductive organs in male mice and the possible mechanism of male secondary hypogonadism (SH) in obesity. Ninety-six mice were randomly assigned to three groups: the control group, diet-induced obesity group, and diet-induced obesity resistant group for 8 weeks and 19 weeks. The effects of short- and long-term high-fat diet on the reproductive organs were determined by measuring sperm count and motility, relative testis weight, testosterone level, pathological changes and apoptosis of Leydig cells. Oxidative stress was evaluated by determining malondialdehyde, H2O2, NO levels, and GSH in testis tissues. CAT, SOD, GSH-Px and Nrf2 mRNA were measured by real-time PCR. Short- and long-term high-fat diet decreased sperm count and motility, relative testis weight, testosterone level; decreased CAT, SOD, GSH-Px and Nrf2 mRNA expression; increased MDA, H2O2, NO and leptin levels; inhibited the activity of CAT and GSH-Px enzymes. Pathological injury and apoptosis of Leydig cells were found in testis tissue. Pathological damage of Leydig cells, oxidative stress in testis tissue, and high level of leptin may provide some evidence to clarify the mechanisms of male SH in obesity.

  12. Leptin Level and Oxidative Stress Contribute to Obesity-Induced Low Testosterone in Murine Testicular Tissue

    Directory of Open Access Journals (Sweden)

    Jian Zhao

    2014-01-01

    Full Text Available Objective. This study evaluated the effects of obesity on the function of reproductive organs in male mice and the possible mechanism of male secondary hypogonadism (SH in obesity. Methods. Ninety-six mice were randomly assigned to three groups: the control group, diet-induced obesity group, and diet-induced obesity resistant group for 8 weeks and 19 weeks. The effects of short- and long-term high-fat diet on the reproductive organs were determined by measuring sperm count and motility, relative testis weight, testosterone level, pathological changes and apoptosis of Leydig cells. Oxidative stress was evaluated by determining malondialdehyde, H2O2, NO levels, and GSH in testis tissues. CAT, SOD, GSH-Px and Nrf2 mRNA were measured by real-time PCR. Results. Short- and long-term high-fat diet decreased sperm count and motility, relative testis weight, testosterone level; decreased CAT, SOD, GSH-Px and Nrf2 mRNA expression; increased MDA, H2O2, NO and leptin levels; inhibited the activity of CAT and GSH-Px enzymes. Pathological injury and apoptosis of Leydig cells were found in testis tissue. Conclusions. Pathological damage of Leydig cells, oxidative stress in testis tissue, and high level of leptin may provide some evidence to clarify the mechanisms of male SH in obesity.

  13. Leptin affects prolactin action on milk protein and fat synthesis in the bovine mammary gland.

    Science.gov (United States)

    Feuermann, Y; Mabjeesh, S J; Shamay, A

    2004-09-01

    Leptin, a protein hormone produced and secreted predominantly by white adipose tissue, has a critical role in the regulation and coordination of energy metabolism. Identification of leptin in the milk of several mammals, including humans, led us to investigate its presence and regulatory effect in the cow mammary gland. The expression of leptin receptor in tissue culture of lactating mammary gland was augmented approximately 25 times by prolactin, but had no effect on virgin calf mammary tissue. Expression of leptin in tissue culture from mammary glands of lactating cows was enhanced 2.2-fold by prolactin. No effect of prolactin on leptin and leptin receptor expression was found in mammary gland tissue culture from calves. Leptin-enhanced fatty acid synthesis in the presence of prolactin, but had no effect without presence of prolactin. A similar pattern was found in the expression of alpha-casein and beta-lactoglobulin in mammary gland explants from a lactating cow. Our findings indicate that leptin plays an important role in mammary gland lactogenesis, and that the expression of leptin requires the presence of prolactin.

  14. The effect of aerobic training on serum adiponectin and leptin levels and inflammatory markers of coronary heart disease in obese men.

    Science.gov (United States)

    Akbarpour, M

    2013-03-01

    The aim of this study was to investigate the effect of 12 weeks of aerobic training on the serum levels of adiponectin and leptin and on inflammatory markers of coronary heart disease in obese men. Sixteen non-athlete obese men were randomly assigned to one of two experimental groups. The experimental group underwent aerobic training consisting of three sessions per week for 12 weeks, while the control group did not participate in the training programme during the study period. Five millilitres of venous blood was taken from each participant at the beginning of the study, during week six and at the end of week 12 to measure the levels of leptin, adiponectin, C-reactive protein, interleukin-6 and tumour necrosis factor-α. The findings showed that aerobic training led to decreases in the levels of CRP (P = 0.002), IL-6 (P = 0.001) and leptin (P = 0.003) and an increase in the level of adiponectin (P = 0.002) in the experimental group relative to the control group. In addition, the level of TNF-α decreased in the experimental group after the 12-week aerobic training period, although this change was not statistically significant. According to the results of this study, regular aerobic exercise decreases the potential risk of coronary heart disease by improving the plasma levels of IL-6, adiponectin, leptin and CRP. Additionally, aerobic exercise can be used as effective non-pharmacological treatment to prevent diseases.

  15. 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.

  16. The peroxisome proliferator activated receptor gamma (PPARgamma) ligand rosiglitazone modulates bronchoalveolar lavage levels of leptin, adiponectin, and inflammatory cytokines in lean and obese mice.

    Science.gov (United States)

    Holguin, Fernando; Rojas, Mauricio; Hart, C Michael

    2007-12-01

    Obese mice that lack leptin receptor (db (-) /db (-)) have been shown to have innate bronchial hyperresponsiveness (BHR). It has been proposed that the obesity-mediated BHR may involve a combination of increased leptin and reduced systemic adiponectin levels. The aim of this study was to determine if obesity modifies the airway concentration of leptin and adiponectin and whether treatment with a synthetic peroxisome proliferator-activated receptor gamma (PPARgamma) ligand can reduce airway leptin and increase airway adiponectin. In this study, obese, leptin receptor-deficient (db (-) /db (-)), or lean (db ( + ) /db (-)) mice were treated with rosiglitazone (3 mg/kg/day) or vehicle by gavage daily for 1 week. Bronchioalveolar lavage (BAL) was subsequently performed to determine levels of leptin, adiponectin, and inflammatory cytokines. Treatment with rosiglitazone increased BAL adiponectin levels in lean (p = 0.04) and to a lesser extent in obese mice (p = 0.07). Rosiglitazone treatment lowered leptin levels in lean mice, but increased leptin levels in BAL fluid of obese mice (p < 0.01). The BAL levels of granulocyte-macrophage colony-stimulating factor (GM-CSF) were lower in the lean rosiglitazone-treated group compared with the obese vehicle-treated group and lower in the obese rosiglitazone-treated group compared with the obese vehicle-treated group. These results demonstrate that obesity is associated with alterations in adipokine and cytokine levels in the airways that can be modulated by treatment with roziglitazone.

  17. Leptin Dysregulation Is Specifically Associated With Major Depression With Atypical Features: Evidence for a Mechanism Connecting Obesity and Depression.

    Science.gov (United States)

    Milaneschi, Yuri; Lamers, Femke; Bot, Mariska; Drent, Madeleine L; Penninx, Brenda W J H

    2017-05-01

    Obesity-related dysregulation of leptin signaling (e.g., hyperleptinemia due to central functional resistance) may affect mood. However, evidence for leptin dysregulation in major depressive disorder (MDD) is conflicting. Inconclusive findings may be attributable to heterogeneity of MDD, aggregating biologically different subtypes. We examined the relationship of leptin with MDD, its common subtypes (typical and atypical), and clinical features. The sample consisted of participants (aged 18 to 65 years) from the Netherlands Study of Depression and Anxiety with current (n = 1062) or remitted (n = 711) MDD and healthy control subjects (n = 497). Diagnoses of MDD and subtypes were based on DSM-IV symptoms. Additional symptoms were measured with the Inventory of Depressive Symptomatology. Blood levels of leptin and adiposity indexes (body mass index and waist circumference) were assessed. As compared to control subjects, higher leptin was associated with the atypical MDD subtype both for remitted (n = 144, odds ratio = 1.53, 95% confidence interval = 1.16-2.03, p = .003) and current (n = 270, odds ratio = 1.90, 95% confidence interval = 1.51-2.93, p = 5.3e-8) cases. This association was stronger for increasing adiposity levels (leptin by body mass index interaction, p depressed patients, higher leptin was associated with key symptoms identifying the atypical subtype, such as hyperphagia, increased weight, and leaden paralysis. Leptin dysregulation (resistance) may represent an underlying mechanism connecting obesity and MDD with atypical features. Development of treatment effectively targeting leptin resistance may benefit patients with atypical depression characterized by obesity-related metabolic alterations. Copyright © 2017 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  18. Novel Leptin Receptor Mutations Identified in Two Girls with Severe Obesity Are Associated with Increased Bone Mineral Density

    NARCIS (Netherlands)

    S.E. Hannema (Sabine); Wit, J.M. (Jan M.); E.C.A.M. Houdijk (Mieke); A. van Haeringen (Arie); E.C. Bik (Elsa); A. Verkerk; A.G. Uitterlinden (André); S.G. Kant (Sarina); W. Oostdijk (Wilma); E. Bakker (Egbert); H.A. Delemarre-van de Waal (Henriette); M. Losekoot (Monique)

    2016-01-01

    textabstractBackground: Recessive mutations in the leptin receptor (LEPR) are a rare cause of hyperphagia and severe early-onset obesity. To date, the phenotype has only been described in 25 obese children, some of whom also had altered immune function, hypogonadotropic hypogonadism, reduced growth

  19. Testosterone interacts with the feedback mechanisms engaged by Tyr985 of the leptin receptor and diet-induced obesity.

    Science.gov (United States)

    Johnson, Joshua A; Calo, Sal; Nair, Lekshmi; IglayReger, Heidi B; Greenwald-Yarnell, Megan; Skorupski, Josh; Myers, Martin G; Bodary, Peter F

    2012-11-01

    Inhibitory signaling through Tyr985 of the leptin receptor contributes to the attenuation of anorectic leptin action in obese animals. Leptin receptor (LEPR-B) Tyr985Leu homozygote mutant mice (termed l/l) were previously generated to study Tyr985's contributions to inhibition of LEPR-B signaling; young female l/l mice display a lean, leptin-sensitive phenotype, while young male l/l are not significantly different from wild-type. We report here that testosterone (but not estrogen) determines the sex-specificity of the l/l phenotype. This provides additional insight into the cellular mechanism by which gonadal hormones determine central sensitivity to leptin, and may help elucidate the long-noted sex differences in leptin sensitivity. Additionally, we observed that Tyr985 signaling protects against a diet-dependent switch that exacerbates obesity with high fat feeding, such that the enhanced leptin sensitivity of l/l mice on a normal diet leads to increased adiposity in the face of chronic high-fat diet. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Melatonin Efficacy in Obese Leptin-Deficient Mice Heart

    Directory of Open Access Journals (Sweden)

    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.

  1. Adiponectin but not leptin is involved in early hepatic disease in morbidly obese patients.

    Science.gov (United States)

    Hindle, Anna Katharine; Edwards, Claire; Mendonsa, Alisha; Rojkind, Marcos; McCaffrey, Tim; Fu, Sidney; Brody, Fred

    2010-07-01

    Pathologic changes in the liver are common in morbidly obese patients, and insulin resistance may potentiate the progression of nonalcoholic steatohepatitis to fibrosis and cirrhosis. This study investigates the impact of leptin and adiponectin in morbidly obese diabetic and nondiabetic patients with regard to histopathologic changes in the liver. Thirty-seven morbidly obese patients who underwent bariatric surgery with liver biopsies were enrolled in the study. Fourteen were diabetic and 23 were nondiabetic. Intraoperative liver tissue was sent for histopathologic analysis and extraneous intraoperative tissue was snap-frozen in liquid nitrogen. Total RNA was extracted and RNA was reverse transcribed to cDNA. Real-time quantitative PCR was performed to determine relative gene expression levels. The data were analyzed using a logarithmic transformation and normalized by 18S ribosome expression. Student's t test was used for statistical analysis with p < or = 0.05 as significant. Adiponectin expression was downregulated 4.4-fold (p < or = 0.05) in liver samples with evidence of inflammation on pathology. When hepatic inflammation was evaluated separately, there were no statistically significant differences in adiponectin levels between the diabetic and nondiabetic patients. However, overall adiponectin levels in hepatic samples of diabetic patients were 3.8-fold higher than those of nondiabetic patients (p < or = 0.05). There were no significant differences in leptin levels regardless of hepatic pathology or diabetic status. This study illustrates that there is a downregulation of adiponectin in morbidly obese patients with inflammatory infiltrates in the liver. Variations in adiponectin levels could be an indicator of disease progression since inflammatory infiltrates are commonly associated with nonalcoholic steatohepatitis (NASH) in morbidly obese patients. Currently, we are using human myofibroblasts derived from livers of morbidly obese people to further

  2. [Association between feeding behavior, and genetic polymorphism of leptin and its receptor in obese Chilean children].

    Science.gov (United States)

    Valladares, Macarena; Obregón, Ana María; Weisstaub, Gerardo; Burrows, Raquel; Patiño, Ana; Ho-Urriola, Judith; Santos, José Luis

    2014-09-12

    Leptin (LEP) is mainly produced in adipose tissue and acts in the hypothalamus to regulate energy intake. Mutations in the LEP gene or its receptor (LEPR) that produce monogenic obesity are infrequent. However, LEP and LEPR polymorphisms have been associated with obesity multifactorial, due to the association found with body weight and eating behavior. Measure the association between LEP and LEPR polymorphisms with childhood obesity and eating behavior. 221 Chilean obese children (BMI above the 95th percentile) were recruited. Parents of 134 of these children were also recruited to determine the association between LEP and LEPR polymorphisms with obesity in a case study-parent trio. Eating behavior was measured through the questionnaire of three factors progenitors' version (TFEQ-P19) and eating behavior in children (CEBQ). No significant difference between the studied polymorphisms and childhood obesity, after correction for multiple comparisons, was observed. The dimensions; "Slow eating", "emotional eating", "enjoyment of food" and "uncontrolling eating" were significant associated with certain polymorphisms of LEP and LEPR. There would be an association between polymorphisms of the LEP and LEPR genes with eating behavior in Chilean obese children. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  3. Deconstructing obesity: the face of fatness before and after the discovery of leptin.

    Science.gov (United States)

    Grayson, B E; Seeley, R J

    2012-01-01

    The prevalence and severity of obesity have increased to epidemic proportions around the globe, and over two-thirds of the US population grapples with either being overweight or obese. Obesity and its comorbidities not only subtract from quality of overall life, but also claim a substantial cost to life. In this edition of 'Then and now', two seminal papers by D.L. Coleman, 'The influence of genetic background on the expression of the obese (ob) gene in the mouse' and 'Effects of parabiosis of obese with diabetes and normal mice', which featured in Diabetologia in 1973, are appraised for their merit and foresight regarding the present eruption of research into what has consequently been labelled 'the metabolic syndrome'. These two studies determined that a then-unknown circulating factor was responsible for the obese/diabetic state of the ob/ob mouse by using a parabiosis model. This circulating factor was later dubbed 'leptin'. The present commentary juxtaposes the astute deduction and simple methods used over 35 years ago and modern research methods as we go forth in our effort to successfully treat and prevent obesity, diabetes and their co-morbidities.

  4. High Leptin Level Attenuates Embryo Development in Overweight/Obese Infertile Women by Inhibiting Proliferation and Promotes Apoptosis in Granule Cell.

    Science.gov (United States)

    Lin, Xian-Hua; Wang, Hui; Wu, Dan-Dan; Ullah, Kamran; Yu, Tian-Tian; Ur Rahman, Tanzil; Huang, He-Feng

    2017-07-01

    Obesity appears to be associated with female reproductive dysfunction and infertility. Women with obesity undergoing in vitro fertilization (IVF) had poor oocyte quality, decreased embryo development, and poor pregnancy outcome. However, the mechanism linking obesity to poor reproductive outcomes is still unclear. Obesity is frequently accompanied with elevated leptin levels. Here we aimed to evaluate the effect of high leptin level in follicular fluid (FF) on the proliferation and apoptosis in granule cells and correlate these findings with poor reproductive outcomes in infertile women with overweight or obesity who underwent IVF treatment. We investigated clinical and ongoing pregnancy rates in 189 infertile women who underwent IVF. Leptin levels were quantified in peripheral blood and FF as well. In vitro cell model was used to explore the potential effect of high leptin on the proliferation and apoptosis in granulosa cells. Results showed reduced clinical and ongoing pregnancy rates in overweight/obesity women who underwent IVF compared to control with normal BMI. On the other hand, leptin levels presented significant increase in peripheral blood and FF in overweight/obese women. Leptin level in FF was negatively correlated to good quality embryo rate. Importantly, in vitro study showed that leptin inhibited cells proliferation and promoted apoptosis by upregulation of caspase-3 and downregulation of Bcl-2 in granulosa cells in a dose dependent manner. These observations suggest that leptin may acts as a local mediator to attenuate embryo development and reduce fertility in obese patients. © Georg Thieme Verlag KG Stuttgart · New York.

  5. Gender differences in serum leptin in obese people: relationships with testosterone, body fat distribution and insulin sensitivity.

    Science.gov (United States)

    Vettor, R; De Pergola, G; Pagano, C; Englaro, P; Laudadio, E; Giorgino, F; Blum, W F; Giorgino, R; Federspil, G

    1997-12-01

    Testosterone levels are decreased in obese men but increased in obese women. The interplay between gonadal steroids and leptin is, at present, far from being elucidated. This study was carried out to investigate the relationship between serum leptin, plasma insulin, insulin sensitivity and free testosterone in 46 men (29 obese and 17 lean) and 65 premenopausal women (42 obese and 23 lean). In all subjects, anthropometric parameters and serum levels of insulin, leptin, free testosterone (T), dehydroepiandrosterone sulphate and sex hormone-binding globulin were measured. An oral glucose tolerance test (OGTT) and an insulin tolerance test were also performed to determine the insulin sensitivity index. Our results show a significant difference in serum leptin between lean and obese men (3.19 +/- 0.71 vs. 20.28 +/- 0.26 ng mL-1; P < 0.0005) as well as between lean and obese women (10.78 +/- 2.14 vs. 34.79 +/- 2.26 ng mL-1; P < 0.00001). Basal T concentration in the obese men was significantly lower than in the control group (18.6 +/- 1.3 vs. 23.3 +/- 1.4 ng L-1; P < 0.01), whereas in the obese women it was significantly higher than in the control group (2.0 +/- 0.2 vs. 1.3 +/- 0.1 ng L-1; P < 0.05). When multiple linear regression was performed without body mass index (BMI) in the statistical model, leptin was correlated with basal insulin (P < 0.0001), insulin sensitivity (P < 0.0001) and T (P < 0.0001) in both men and women. When BMI was included in the model as an independent variable, leptin was significantly correlated only with BMI (P < 0.0001), the degree of insulin resistance (P < 0.05) and T (only in men, P < 0.05). This study confirms that serum leptin is strongly correlated with the degree of obesity and female sex. The negative correlation between leptin and T in men, independent of BMI, is consistent with the hypothesis that T may possess an inhibitory effect on adipocyte ob gene transcription.

  6. The Prader-Willi syndrome proteins MAGEL2 and necdin regulate leptin receptor cell surface abundance through ubiquitination pathways.

    Science.gov (United States)

    Wijesuriya, Tishani Methsala; De Ceuninck, Leentje; Masschaele, Delphine; Sanderson, Matthea R; Carias, Karin Vanessa; Tavernier, Jan; Wevrick, Rachel

    2017-11-01

    In Prader-Willi syndrome (PWS), obesity is caused by the disruption of appetite-controlling pathways in the brain. Two PWS candidate genes encode MAGEL2 and necdin, related melanoma antigen proteins that assemble into ubiquitination complexes. Mice lacking Magel2 are obese and lack leptin sensitivity in hypothalamic pro-opiomelanocortin neurons, suggesting dysregulation of leptin receptor (LepR) activity. Hypothalamus from Magel2-null mice had less LepR and altered levels of ubiquitin pathway proteins that regulate LepR processing (Rnf41, Usp8, and Stam1). MAGEL2 increased the cell surface abundance of LepR and decreased their degradation. LepR interacts with necdin, which interacts with MAGEL2, which complexes with RNF41 and USP8. Mutations in the MAGE homology domain of MAGEL2 suppress RNF41 stabilization and prevent the MAGEL2-mediated increase of cell surface LepR. Thus, MAGEL2 and necdin together control LepR sorting and degradation through a dynamic ubiquitin-dependent pathway. Loss of MAGEL2 and necdin may uncouple LepR from ubiquitination pathways, providing a cellular mechanism for obesity in PWS. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Leptin level correlates with obesity and health related quality of life in obstructive sleep apnea syndrome patients.

    Science.gov (United States)

    Dubey, Abhishek; Kant, Surya; Tiwari, Sunita; Agarwal, Sarita; Mahdi, Abbas Ali

    2015-04-01

    Leptin takes part in regulation of energy balance, neuronal functions, pain and mood. It may act as intermediary marker for various components of HRQOL in patients of obstructive sleep apnea syndrome. To document the correlation among leptin levels, obesity and HRQoL in OSAS patients. A tertiary care hospital based cross-sectional study was done in 224 subjects aged 18-65 years, after taking informed consent. Subjects with previous history of smoking, Liver disease, COPD, CHD, T2 DM, asthma, cancer, end stage renal disease, heart failure, any endocrine disorder including Cushing syndrome, thyroid, on systemic steroid or any continuous medication for last 6 months, on dieting or suffering from any disability condition (other than obesity and OSAS) affecting their HRQoL were excluded from the study. All subjects underwent Polysomnography. Leptin assay was done by ELISA method. Hindi version of HRQoL tool SF-36 was used to evaluate HRQoL. SPSS 20 was used to analyse data. Three groups (AHI 15) were compared. Significant differences were observed in BMI, NC, WC, WHR and ESS. Differences were not significant in sleep architecture and Leptin level. SF-36 HRQoL, scores were observed decreased with increase in severity of disease. Leptin level was found significantly correlated with "Role limitations due to physical health problems", "Social functioning", Hypopnea and obesity indices. In these subjects Obesity indices are the most important correlates of Leptin level. Oxygen desaturation indices with exception of Hypopnea and HRQoL may not be exclusively correlated to leptin levels. Copyright © 2015 Tuberculosis Association of India. Published by Elsevier B.V. All rights reserved.

  8. Biochemical characterisation of a Kunitz-type inhibitor from Tamarindus indica L. seeds and its efficacy in reducing plasma leptin in an experimental model of obesity.

    Science.gov (United States)

    Medeiros, Amanda Fernandes de; Costa, Izael de Sousa; Carvalho, Fabiana Maria Coimbra de; Kiyota, Sumika; Souza, Beatriz Blenda Pinheiro de; Sifuentes, Daniel Nogoceke; Serquiz, Raphael Paschoal; Maciel, Bruna Leal Lima; Uchôa, Adriana Ferreira; Santos, Elizeu Antunes Dos; Morais, Ana Heloneida de Araújo

    2018-12-01

    A trypsin inhibitor isolated from tamarind seed (TTI) has satietogenic effects in animals, increasing the cholecystokinin (CCK) in eutrophy and reducing leptin in obesity. We purified TTI (pTTI), characterised, and observed its effect upon CCK and leptin in obese Wistar rats. By HPLC, and after amplification of resolution, two protein fractions were observed: Fr1 and Fr2, with average mass of [M + 14H] +  = 19,594,690 Da and [M + 13H] +  = 19,578,266 Da, respectively. The protein fractions showed 54 and 53 amino acid residues with the same sequence. pTTI presented resistance to temperature and pH variations; IC 50 was 2.7 × 10 -10  mol.L -1 and Ki was 2.9 × 10 -11  mol.L -1 . The 2-DE revealed spots with isoelectric points between pH 5 and 6, and one near pH 8. pTTI action on leptin decrease was confirmed. We conclude that pTTI is a Kunitz trypsin inhibitor with possible biotechnological health-related application.

  9. 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, J E; Zhou, S; Giese, K; Williams, L T; Escobedo, J A; Dwarki, V J

    1997-12-09

    The ob/ob mouse is genetically deficient in leptin and exhibits a phenotype that includes obesity and non-insulin-dependent diabetes mellitus. 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.

  10. 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

  11. Protein tyrosine phosphatase-1B contributes to LPS-induced leptin resistance in male rats

    Science.gov (United States)

    Borges, Beatriz de Carvalho; Rorato, Rodrigo C.; Uchoa, Ernane Torres; Marangon, Paula B.; Elias, Carol F.; Antunes-Rodrigues, Jose

    2014-01-01

    Leptin resistance is induced by the feedback inhibitors tyrosine phosphatase-1B (PTP1B) and decreased Src homology 2 domain-containing tyrosine phosphatase-2 (SHP-2) signaling. To investigate the participation of PTP1B and SHP-2 in LPS-induced leptin resistance, we injected repeated (6-LPS) intraperitoneal LPS doses (100 μg/kg ip) for comparison with a single (1-LPS) treatment and evaluated the expression of SHP-2, PTP1B, p-ERK1/2, and p-STAT3 in the hypothalamus of male Wistar rats. The single LPS treatment increased the expression of p-STAT3 and PTP1B but not SHP-2. The repeated LPS treatment reduced SHP-2, increased PTP1B, and did not change p-STAT3. We observed that the PTP1B expression induced by the endotoxin was highly colocalized with leptin receptor cells in the hypothalamus of LepRb-IRES-Cre-tdTomato reporter mice. The single, but not the repeated, LPS treatment decreased the food intake and body weight. Leptin had no stimulatory effect on the hypophagia, body weight loss, or pSTAT3 expression in 6-LPS rats, indicating leptin unresponsiveness. Notably, the PTP1B inhibitor (3.0 nmol/rat in 5 μl icv) restored the LPS-induced hypophagia in 6-LPS rats and restored the ability of leptin to reduce food intake and body weight as well as to phosphorylate STAT3 in the arcuate, paraventricular, and ventromedial nuclei of the hypothalamus. The present data suggest that an increased PTP1B expression in the hypothalamus underlies the development of leptin resistance during repeated exposure to LPS. Our findings contribute to understanding the mechanisms involved in leptin resistance during low-grade inflammation as seen in obesity. PMID:25352433

  12. Protein tyrosine phosphatase-1B contributes to LPS-induced leptin resistance in male rats.

    Science.gov (United States)

    Borges, Beatriz de Carvalho; Rorato, Rodrigo C; Uchoa, Ernane Torres; Marangon, Paula B; Elias, Carol F; Antunes-Rodrigues, Jose; Elias, Lucila L K

    2015-01-01

    Leptin resistance is induced by the feedback inhibitors tyrosine phosphatase-1B (PTP1B) and decreased Src homology 2 domain-containing tyrosine phosphatase-2 (SHP-2) signaling. To investigate the participation of PTP1B and SHP-2 in LPS-induced leptin resistance, we injected repeated (6-LPS) intraperitoneal LPS doses (100 μg/kg ip) for comparison with a single (1-LPS) treatment and evaluated the expression of SHP-2, PTP1B, p-ERK1/2, and p-STAT3 in the hypothalamus of male Wistar rats. The single LPS treatment increased the expression of p-STAT3 and PTP1B but not SHP-2. The repeated LPS treatment reduced SHP-2, increased PTP1B, and did not change p-STAT3. We observed that the PTP1B expression induced by the endotoxin was highly colocalized with leptin receptor cells in the hypothalamus of LepRb-IRES-Cre-tdTomato reporter mice. The single, but not the repeated, LPS treatment decreased the food intake and body weight. Leptin had no stimulatory effect on the hypophagia, body weight loss, or pSTAT3 expression in 6-LPS rats, indicating leptin unresponsiveness. Notably, the PTP1B inhibitor (3.0 nmol/rat in 5 μl icv) restored the LPS-induced hypophagia in 6-LPS rats and restored the ability of leptin to reduce food intake and body weight as well as to phosphorylate STAT3 in the arcuate, paraventricular, and ventromedial nuclei of the hypothalamus. The present data suggest that an increased PTP1B expression in the hypothalamus underlies the development of leptin resistance during repeated exposure to LPS. Our findings contribute to understanding the mechanisms involved in leptin resistance during low-grade inflammation as seen in obesity. Copyright © 2015 the American Physiological Society.

  13. Chronic Kidney Disease, Obesity, and Hypertension: The Role of Leptin and Adiponectin

    Directory of Open Access Journals (Sweden)

    M. Tesauro

    2012-01-01

    Full Text Available Chronic kidney disease is a major public health problem and characterized by a progressive loss in renal function over a period of months or years as defined by structural or functional abnormalities of the kidney. Several elements contribute to determine a progression of the kidney injury, inducing a worsening of renal damage and accelerating the decline of renal function: obesity and hypertension are two known factors of kidney progression. Remarkable improvements have been recently achieved in the study of the endocrine features of the adipose tissue and have been able to produce hormone-like peptides named adipokines or adipocytokines. Among these adipocytokines, which represent a link between obesity, hypertension, and chronic nephropathy, leptins and adiponectin appear to play an important role. Leptin not only is a prohypertension element (renal progression factor through the activation sympathetic nervous, but also is able to induce prosclerotic effects directly on the kidney. In contrast, a decline of adiponectin levels has been shown to be related to a picture of hypertension: an endothelial dysfunction has been described as the main pathogenic mechanism responsible for this phenomenon.

  14. Proinflammatory Cytokines and Leptin Are Increased in Serum of Prepubertal Obese Children

    Directory of Open Access Journals (Sweden)

    A. Denizmen Aygun

    2005-01-01

    leptin concentration was significantly higher in the obese children at 19.9±7.4 ng/mL, than the control group (7.9±5.1 ng/mL. Serum IL-1β, IL-6, and TNF-α levels were also significantly higher in the obese group than controls (33.0±8.9, 45.2±11.8, and 9.2±2.3 pg/mL, versus 3.6±1.0, 13.1±3.9, and 3.9±1.0 pg/mL, resp. In controversy, serum IL-2 level was diminished in the obese group as 0.4±0.1 versus 0.9±0.1 U/L. Obesity may be a low-grade systemic inflammatory disease. Obese prepubertal children have elevated serum levels of IL-1β, IL-6, and TNF-α which are known as markers of inflammation.

  15. Taurine supplementation preserves hypothalamic leptin action in normal and protein-restricted mice fed on a high-fat diet.

    Science.gov (United States)

    Camargo, Rafael L; Batista, Thiago M; Ribeiro, Rosane A; Branco, Renato C S; Da Silva, Priscilla M R; Izumi, Clarice; Araujo, Thiago R; Greene, Lewis J; Boschero, Antonio C; Carneiro, Everardo M

    2015-11-01

    Malnutrition programs the neuroendocrine axis by disruption of food-intake control, leading to obesity. Taurine (Tau) is neuroprotective and improves anorexigenic actions in the hypothalamus. We evaluated the hypothalamic gene-expression profile and food-intake control in protein-restricted mice submitted to a high-fat diet (HFD) and Tau supplementation. Mice were fed on a control (14 % protein-C) or a protein-restricted diet (6 % protein-R) for 6 weeks. Thereafter, mice received, or not, HFD for 8 weeks (CH and RH) with or without 5 % Tau supplementation (CHT and RHT). Protein restriction led to higher food intake, but calories were matched to controls. Excessive calorie intake occurred in HFD mice and this was prevented by Tau supplementation only in the CH group. Additionally, RH and CH mice developed hypothalamic leptin resistance, which was prevented by Tau. Global alterations in the expressions of genes involved in hypothalamic metabolism, cellular defense, apoptosis and endoplasmic reticulum stress pathways were induced by dietary manipulations and Tau treatment. The orexigenic peptides NPY and AgRP were increased by protein restriction and lowered by the HFD. The anorexigenic peptide Pomc was increased by HFD, and this was prevented by Tau only in CH mice. Thus, food intake was disrupted by dietary protein restriction and obesity. HFD-induced alterations were not enhanced by previous protein deficiency, but the some beneficial effects of Tau supplementation upon food intake were blunted by protein restriction. Tau effects upon feeding behavior control are complex and involve interactions with a vast gene network, preventing hypothalamic leptin resistance.

  16. The Role of Obesity, Different Fat Compartments and Sleep Apnea Severity in Circulating Leptin Levels: The Icelandic Sleep Apnea Cohort Study

    Science.gov (United States)

    Arnardottir, Erna S.; Maislin, Greg; Jackson, Nick; Schwab, Richard J.; Benediktsdottir, Bryndis; Teff, Karen; Juliusson, Sigurdur; Pack, Allan I.; Gislason, Thorarinn

    2012-01-01

    Objectives To assess whether sleep apnea severity has an independent relationship with leptin levels in blood after adjusting for different measures of obesity and whether the relationship between OSA severity and leptin levels differs depending on obesity level. Methods Cross-sectional study of 452 untreated obstructive sleep apnea (OSA) patients (377 males and 75 females), in the Icelandic Sleep Apnea Cohort (ISAC), age 54.3±10.6 (mean±SD), BMI 32.7±5.3 kg/m2 and apnea-hypopnea index (AHI) 40.2 ± 16.1 events/hour. A sleep study and magnetic resonance imaging of abdominal visceral and subcutaneous fat volume were performed as well as fasting serum morning leptin levels measured. Results Leptin levels were more highly correlated with body mass index (BMI), total abdominal and subcutaneous fat volume than visceral fat volume per se. No relationship was found between sleep apnea severity and leptin levels, assessed within three BMI groups (BMI35 kg/m2). In a multiple linear regression model, adjusted for gender, BMI explained 38.7% of the variance in leptin levels, gender explained 21.2% but OSA severity did not have a significant role and no interaction was found between OSA severity and BMI on leptin levels. However, hypertension had a significant effect on the interaction between OSA severity and obesity (p=0.04). In post-hoc analysis for nonhypertensive OSA subjects (n=249), the association between leptin levels and OSA severity explained a minor but significant variance (3.2%) in leptin levels. This relationship was greatest for nonobese nonhypertensive subjects (significant interaction with obesity level). No relationship of OSA severity and leptin levels was found for hypertensive subjects (n=199). Conclusion Obesity and gender are the dominant determinants of leptin levels. OSA severity is not related to leptin levels except to a minor degree in nonhypertensive nonobese OSA subjects. PMID:22964793

  17. Modulation of leptin, insulin, and growth hormone in obese pony mares under chronic nutritional restriction and supplementation with ractopamine hydrochloride.

    Science.gov (United States)

    Buff, Preston R; Johnson, Philip J; Wiedmeyer, Charles E; Ganjam, Venkataseshu K; Messer Iv, Nat T; Keisler, Duane H

    2006-01-01

    Horses fed beyond their nutritional requirement and that are physically inactive will develop obesity, which is often accompanied by insulin resistance and heightened risk of laminitis. The use of pharmacologic agents in combination with nutritional restriction may promote weight loss in obese horses unable to exercise because of laminitic pain. This study shows that reducing feed intake of brome grass hay to 75% of ad libitum intake in obese pony mares reduces body weight without induced exercise. Additional supplementation of ractopamine hydrochloride for 6 weeks resulted in a tendency for increased weight loss. Subsequent modulation of obesity-associated hormones, leptin and insulin, as a result of caloric restriction was observed.

  18. Acute insulin-induced elevations of circulating leptin and feeding inhibition in lean but not obese rats.

    Science.gov (United States)

    Singh, Kimberly A; Boozer, Carol N; Vasselli, Joseph R

    2005-08-01

    Insulin has been shown to stimulate leptin mRNA expression acutely in rat adipose tissue, but its short-term effects on circulating leptin levels, and subsequent feeding behavior, have not been well described. We used 11-mo-old female selectively bred obesity-resistant (OR) and obesity-prone (OP) Sprague-Dawley rats maintained on laboratory chow to investigate this question. At testing, body weights and basal leptin levels of the OP rats were significantly elevated compared with the OR rats. In the 3-h fasted state, injection of 2.0 U insulin/kg ip resulted in significant elevations of plasma leptin at 4 h postinjection in both OP and OR groups (hour 4, +2.50 and +5.98 ng/ml, respectively). In separate feeding tests with the same groups, intake of laboratory chow pellets was significantly inhibited during hours 2-4 after 2.0 U/kg of insulin in the OR (-80.1%, P < 0.05), but not in the OP group, compared with intake after saline injections. In feeding tests with palatable moderately high-fat pellets after 2.0 and 3.0 U insulin/kg ip, significant decreases between hours 2 and 4 in intake were seen in the OR group only (-41.0 and -68.3%, respectively). Thus feeding inhibition coincides with insulin-induced elevations of plasma leptin in lean but not obese Sprague-Dawley rats. Our data suggest that elevations of leptin within the physiological range may contribute to short-term inhibition of food intake in rats and that this process may be stimulated by feeding-related insulin release.

  19. Longitudinal Analysis of Leptin Variation during Weight Regain after Weight Loss in Obese Children

    DEFF Research Database (Denmark)

    Jens-Christian, Holm; Michael, Gamborg; Leigh, Ward

    2009-01-01

    . Results: Children with the greatest increases in BMI standard deviation score (SDS) exhibited the largest leptin increments. The disproportionate reduction of leptin seen during weight loss recovered after weight loss. Leptin increases mirrored increases in BMI SDS during weight regain, and the leptin......-BMI SDS relationship seen during follow-up resembled the baseline leptin-BMI SDS relationship. Conclusion: Proportional increases of leptin and BMI SDS during weight regain suggests an intact leptin response during re-accumulation of fat. Following the pronounced reduction of leptin during weight loss......Objective: This study assessed if lower than predicted serum leptin concentrations seen during weight loss persisted during weight regain, with possible implications for weight control. Methods: 115 children were investigated during a 12-week weight loss program. 90 children completed the program...

  20. Longitudinal Analysis of Leptin Variation during Weight Regain after Weight Loss in Obese Children

    DEFF Research Database (Denmark)

    Holm, Jens-Christian; Gamborg, Michael; Ward, Leigh

    2009-01-01

    -BMI SDS relationship seen during follow-up resembled the baseline leptin-BMI SDS relationship. Conclusion: Proportional increases of leptin and BMI SDS during weight regain suggests an intact leptin response during re-accumulation of fat. Following the pronounced reduction of leptin during weight loss......Objective: This study assessed if lower than predicted serum leptin concentrations seen during weight loss persisted during weight regain, with possible implications for weight control. Methods: 115 children were investigated during a 12-week weight loss program. 90 children completed the program....... Results: Children with the greatest increases in BMI standard deviation score (SDS) exhibited the largest leptin increments. The disproportionate reduction of leptin seen during weight loss recovered after weight loss. Leptin increases mirrored increases in BMI SDS during weight regain, and the leptin...

  1. Longitudinal Analysis of Leptin Variation during Weight Regain after Weight Loss in Obese Children

    DEFF Research Database (Denmark)

    Jens-Christian, Holm; Michael, Gamborg; Leigh, Ward

    2009-01-01

    Objective: This study assessed if lower than predicted serum leptin concentrations seen during weight loss persisted during weight regain, with possible implications for weight control. Methods: 115 children were investigated during a 12-week weight loss program. 90 children completed the program....... Results: Children with the greatest increases in BMI standard deviation score (SDS) exhibited the largest leptin increments. The disproportionate reduction of leptin seen during weight loss recovered after weight loss. Leptin increases mirrored increases in BMI SDS during weight regain, and the leptin......-BMI SDS relationship seen during follow-up resembled the baseline leptin-BMI SDS relationship. Conclusion: Proportional increases of leptin and BMI SDS during weight regain suggests an intact leptin response during re-accumulation of fat. Following the pronounced reduction of leptin during weight loss...

  2. Maternal obesity programs reduced leptin signaling in the pituitary and altered GH/IGF1 axis function leading to increased adiposity in adult sheep offspring.

    Science.gov (United States)

    Tuersunjiang, Nuermaimaiti; Odhiambo, John F; Shasa, Desiree R; Smith, Ashley M; Nathanielsz, Peter W; Ford, Stephen P

    2017-01-01

    Studies in rodents highlight a role for leptin in stimulation of pituitary growth hormone (GH) secretion, with an impact on body composition regulation. We have reported that maternal obesity (MO) during ovine pregnancy results in hyperphagia, glucose-insulin dysregulation, increased adiposity, hypercortisolemia and hyperleptinemia in mature offspring subjected to a bout of ad libitum feeding. We hypothesized that MO reduces leptin signaling in the pituitary and down regulates the GH/IGF1 axis and increases circulating cortisol leading to increased adiposity in their adult offspring. Male lambs born to MO (n = 6) or control (CON, n = 6) ewes were fed only to requirements until placed on a 12 week ad libitum feeding trial at maturity. The pituitary, hypothalamic arcuate nucleus, and liver were collected at necropsy and mRNA and protein expression determined. Plasma cortisol concentrations were increased (P<0.05) in MO vs. CON offspring at the end of the feeding trial. Further, serum concentrations of IGF1 decreased (P<0.01) and GH tended to decrease (P<0.08) in MO vs. CON offspring. Pituitary mRNA and leptin receptor protein expression were decreased in MO vs. CON offspring in association with decreased GH mRNA expression, and decreased IGF1 mRNA and protein expression in liver. Liver 11β-hydroxysteroid dehydrogenase 1 (11βHSD1) expression was increased (P<0.01) and its cofactor hexose-6-phosphate dehydrogenase tended to increase (P<0.06) in MO vs. CON offspring. 11βHSD2 expression remained unchanged. These data indicate that MO induced an increase in liver conversion of cortisone to cortisol in adult offspring and support a role for leptin signaling in the pituitary in mediating offspring adiposity.

  3. Leptin and psychiatry

    African Journals Online (AJOL)

    QuickSilver

    obese and normal body weight controls, and negatively corre- lated with weight loss due to food restriction. Reports of studies of leptin in patients with anorexia nervosa are limited. In starved female anorectics at very low body weights, leptin levels are reduced significantly.15,16 Leptin in-. Fig. 2. A schematic representation ...

  4. Leptin, Leptin Soluble Receptor, and the Free Leptin Index following a Diet and Physical Activity Lifestyle Intervention in Obese Males and Females

    Directory of Open Access Journals (Sweden)

    Jeffrey E. Herrick

    2016-01-01

    Full Text Available Leptin (LEP is associated with appetite regulation and metabolism. Concentration is linear with adiposity, suggesting LEP resistance. LEP circulates freely and bound with its soluble receptor (sOB-r; the ratio is the free leptin index (FLI, an index of leptin resistance; lower FLI suggests reduced biological action. Purpose. The aim was to determine the effect of changes in adipose tissue distribution on LEP, sOB-r, and FLI following 6 months (6 M of a diet/exercise weight loss program (WLP. In addition, we aim to identify predictors of the FLI. Methods. 6 M WLP consisted of diet/lifestyle interventions following ADA guidelines. Body composition was assessed by DXA. LEP and sOB-r analysis were done via ELISA. Results. 10 adults completed the WLP. Significant reductions were seen in total fat percentage (% fat, nontrunk fat, (NTF, and trunk fat (TF from base to 3 m and 6 M (p≤0.05. The FLI were reduced at 3 M and 6 M for males and 6 M for females. Total body fat and body weight predicted the FLI in both sexes. Conclusions. LEP and FLI reductions following 6 M of WLP were achieved independent of sOB-r changes. We also demonstrate that the FLI can be predicted noninvasively through total fat mass and body weight in kilograms.

  5. Inactivation of SOCS3 in leptin receptor-expressing cells protects mice from diet-induced insulin resistance but does not prevent obesity a

    OpenAIRE

    Pedroso, João A.B.; Buonfiglio, Daniella C.; Cardinali, Lais I.; Furigo, Isadora C.; Ramos-Lobo, Angela M.; Tirapegui, Julio; Elias, Carol F.; Donato, Jose

    2014-01-01

    Therapies that improve leptin sensitivity have potential as an alternative treatment approach against obesity and related comorbidities. We investigated the effects of Socs3 gene ablation in different mouse models to understand the role of SOCS3 in the regulation of leptin sensitivity, diet-induced obesity (DIO) and glucose homeostasis. Neuronal deletion of SOCS3 partially prevented DIO and improved glucose homeostasis. Inactivation of SOCS3 only in LepR-expressing cells protected against lep...

  6. The Effects of Leptin on Breastfeeding Behaviour

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    Anna M. Cannon

    2015-09-01

    Full Text Available Breastfed infants have a reduced risk of becoming overweight and/or obese later in life. This protective effect has been partly attributed to leptin present in breastmilk. This study investigated 24-h variations of skim milk leptin and its relationship with breastmilk macronutrients and infant breastfeeding patterns. Exclusive breastfeeding mothers of term singletons (n = 19; age 10 ± 5 weeks collected pre- and post-feed breastmilk samples for every breastfeed over a 24-h period and test-weighed their infants to determine milk intake at every breastfeed over a 24-h period. Samples (n = 454 were analysed for leptin, protein, lactose and fat content. Skim milk leptin concentration did not change with feeding (p = 0.184. However, larger feed volumes (>105 g were associated with a decrease in post-feed leptin levels (p = 0.009. There was no relationship between the change in leptin levels and change in protein (p = 0.313 or lactose levels (p = 0.587 between pre- and post-feed milk, but there was a trend for a positive association with changes in milk fat content (p = 0.056. Leptin concentration significantly increased at night (p < 0.001 indicating a possible 24-h pattern. Leptin dose (ng was not associated with the time between feeds (p = 0.232. Further research should include analysis of whole breastmilk and other breastmilk fractions to extend these findings.

  7. Maternal obesity programs increased leptin gene expression in rat male offspring via epigenetic modifications in a depot-specific manner.

    Science.gov (United States)

    Lecoutre, Simon; Oger, Frederik; Pourpe, Charlène; Butruille, Laura; Marousez, Lucie; Dickes-Coopman, Anne; Laborie, Christine; Guinez, Céline; Lesage, Jean; Vieau, Didier; Junien, Claudine; Eberlé, Delphine; Gabory, Anne; Eeckhoute, Jérôme; Breton, Christophe

    2017-08-01

    According to the Developmental Origin of Health and Disease (DOHaD) concept, maternal obesity and accelerated growth in neonates predispose offspring to white adipose tissue (WAT) accumulation. In rodents, adipogenesis mainly develops during lactation. The mechanisms underlying the phenomenon known as developmental programming remain elusive. We previously reported that adult rat offspring from high-fat diet-fed dams (called HF) exhibited hypertrophic adipocyte, hyperleptinemia and increased leptin mRNA levels in a depot-specific manner. We hypothesized that leptin upregulation occurs via epigenetic malprogramming, which takes place early during development of WAT. As a first step, we identified in silico two potential enhancers located upstream and downstream of the leptin transcription start site that exhibit strong dynamic epigenomic remodeling during adipocyte differentiation. We then focused on epigenetic modifications (methylation, hydroxymethylation, and histone modifications) of the promoter and the two potential enhancers regulating leptin gene expression in perirenal (pWAT) and inguinal (iWAT) fat pads of HF offspring during lactation (postnatal days 12 (PND12) and 21 (PND21)) and in adulthood. PND12 is an active period for epigenomic remodeling in both deposits especially in the upstream enhancer, consistent with leptin gene induction during adipogenesis. Unlike iWAT, some of these epigenetic marks were still observable in pWAT of weaned HF offspring. Retained marks were only visible in pWAT of 9-month-old HF rats that showed a persistent "expandable" phenotype. Consistent with the DOHaD hypothesis, persistent epigenetic remodeling occurs at regulatory regions especially within intergenic sequences, linked to higher leptin gene expression in adult HF offspring in a depot-specific manner.

  8. Effects of leptin replacement alone and with exendin-4 on food intake and weight regain in weight-reduced diet-induced obese rats

    Science.gov (United States)

    Haver, Alvin; Chelikani, Prasanth K.; Apenteng, Bettye; Perriotte-Olson, Curtis; Anders, Krista; Steenson, Sharalyn; Blevins, James E.

    2012-01-01

    Weight loss in obese humans produces a relative leptin deficiency, which is postulated to activate potent orexigenic and energy conservation mechanisms to restrict weight loss and promote weight regain. Here we determined whether leptin replacement alone or with GLP-1 receptor agonist exendin-4 attenuates weight regain or promotes greater weight loss in weight-reduced diet-induced obese (DIO) rats. Forty percent restriction in daily intake of a high-fat diet in DIO rats for 4 wk reduced body weight by 12%, body fat by 29%, and plasma leptin by 67% and normalized leptin sensitivity. When food restriction ended, body weight, body fat, and plasma leptin increased rapidly. Daily administration of leptin [3-h intraperitoneal (ip) infusions (4 nmol·kg−1·h−1)] at onset and end of dark period for 3 wk did not attenuate hyperphagia and weight regain, nor did it affect mean daily meal sizes or meal numbers. Exendin-4 (50 pmol·kg−1·h−1) infusions during the same intervals prevented postrestriction hyperphagia and weight regain by normalizing meal size. Coadministration of leptin and exendin-4 did not reduce body weight more than exendin-4 alone. Instead, leptin began to attenuate the inhibitory effects of exendin-4 on food intake, meal size, and weight regain by the end of the second week of administration. Plasma leptin in rats receiving leptin was sevenfold greater than in rats receiving vehicle and 17-fold greater than in rats receiving exendin-4. Together, these results do not support the hypothesis that leptin replacement alone or with exendin-4 attenuates weight regain or promotes greater weight loss in weight-reduced DIO rats. PMID:22510712

  9. Pivotal role of leptin in insulin effects

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    R.B. Ceddia

    1998-06-01

    Full Text Available The OB protein, also known as leptin, is secreted by adipose tissue, circulates in the blood, probably bound to a family of binding proteins, and acts on central neural networks regulating ingestive behavior and energy balance. The two forms of leptin receptors (long and short forms have been identified in various peripheral tissues, a fact that makes them possible target sites for a direct action of leptin. It has been shown that the OB protein interferes with insulin secretion from pancreatic islets, reduces insulin-stimulated glucose transport in adipocytes, and increases glucose transport, glycogen synthesis and fatty acid oxidation in skeletal muscle. Under normoglycemic and normoinsulinemic conditions, leptin seems to shift the flux of metabolites from adipose tissue to skeletal muscle. This may function as a peripheral mechanism that helps control body weight and prevents obesity. Data that substantiate this hypothesis are presented in this review.

  10. Differential hypothalamic leptin sensitivity in obese rat offspring exposed to maternal and postnatal intake of chocolate and soft drink

    DEFF Research Database (Denmark)

    Gerstenberg, Marina Kjærgaard; Nilsson, C; Secher, A

    2017-01-01

    Background/objective: Intake of high-energy foods and maternal nutrient overload increases the risk of metabolic diseases in the progeny such as obesity and diabetes. We hypothesized that maternal and postnatal intake of chocolate and soft drink will affect leptin sensitivity and hypothalamic...... astrogliosis (Pobese despite lower energy intake than controls (Pfasting pSTAT3 activity...... assigned to either S or C diet, giving four groups until the end of the experiment at 26 weeks of age. Results: As expected, adult offspring fed the S diet post weaning became obese (body weight: P

  11. The p. N103K mutation of leptin (LEP gene and severe early onset obesity in Pakistan

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    Shabana

    Full Text Available BACKGROUND: Obesity is a complex disorder and has been increasing globally at alarming rates including Pakistan. However, there is scarce research on understanding obesity genetics in Pakistan. Leptin is a hormone secreted by adipocytes in response to satiety and correlates with body weight. Any mutations in the LEP gene have an adverse effect on energy regulation pathway and lead to severe, early onset obesity. To date, only eight mutations have been described in the LEP gene of which p. N103K is one. METHODS: We aimed to analyze the prevalence of this mutation in Pakistani subjects. A total of 475 subjects were genotyped by PCR-RFLP analysis and their serum profiling was done. RESULTS: Results showed that this mutation was present only in one male child with early onset obesity (10 year. He had very low serum leptin levels suggestive of functional impact of the mutation. The prevalence of such mutations is, however, low due to the drastic effects on the energy regulation. CONCLUSION: In conclusion, LEP gene mutations contribute significantly to the monogenic forms of obesity and are important due to the availability of treatment options. Such mutations may exert their effect by directly affecting energy regulation pathway and are more prominent in the early stages of life only.

  12. Genetic association study of selected candidate genes (ApoB, LPL, Leptin and telomere length in obese and hypertensive individuals

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    Saini Divyalakshmi

    2009-09-01

    Full Text Available Abstract Background A genetic study was carried out among obese and hypertensive individuals from India to assess allelic association, if any, at three candidate loci: Apolipoprotein B (ApoB minisatellite and two tetranucleotide repeat loci; LPL (Lipoprotein lipase and Leptin. Attempt has also been made to find out whether telomere length attrition is associated with hypertension and obese individuals. Methods Venous blood samples were collected from 37 normal, 35 obese and 47 hypertensive individuals. Genomic DNA was extracted from peripheral blood mononuclear cells (PBMC and PCR amplifications were achieved using locus specific primers. Genotyping of ApoB minisatellite was performed using 4% polyacrylamide gel electrophoresis (PAGE followed by silver staining, whereas LPL and Leptin loci were genotyped using ALF Express™ DNA sequencer. Telomere length was determined using a recently developed real time based quantitative PCR, where the relative telomere length was determined by calculating the relative ratio of telomere (T and single copy gene (S PCR products which is expressed as T/S ratio. Results All the three loci are highly polymorphic, display high heterozygosity and conform to Hardy-Weinberg's equilibrium expectations. ApoB minisatellite displayed 14 alleles, whereas LPL and Leptin tetranucleotide loci were having 9 and 17 alleles, respectively. Interestingly two new alleles (9 and 11 repeats were detected at ApoB locus for the first time. The alleles at Leptin locus were classified as Class I (lower alleles: 149-200 bp and Class II alleles (higher alleles: >217 bp. Higher alleles at ApoB (>39 repeats, predominant allele 9 at LPL and alleles 164 bp and 224 bp at Leptin loci have shown allelic association with hypertensive individuals. After adjusting the influence of age and gender, the analysis of co-variance (ANCOVA revealed the relative telomere length (T/S ratio in hypertensive individuals to be (1.01 ± 0.021, which was

  13. Racial difference in Acylation Stimulating Protein (ASP correlates to triglyceride in non-obese and obese African American and Caucasian women

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    Cianflone Katherine

    2009-04-01

    Full Text Available Abstract Background Acylation Stimulating Protein (ASP has been shown to influence adipose tissue triglyceride (TG storage. The aim was to examine ethnic differences in ASP and leptin levels in relation to lipid profiles and postprandial changes amongst African American (AA and Caucasian American (CA women matched for BMI. Methods 129 women were recruited in total (age 21 – 73 y: 24 non-obese (BMI 2 CA, 27 obese (BMI ≥ 30 kg/m2 CA, 13 obese diabetic CA, 25 non-obese AA, 25 obese AA, and 15 obese diabetic AA. Cholesterol, HDL-C, LDL-C, apoB, glucose and insulin were measured at baseline. TG, non-esterified fatty acids, leptin, and ASP were measured at baseline and postprandially following a fat meal. Results ASP, leptin, insulin and TG were significantly increased in obese subjects within each race. However, AA women had significantly lower ASP and TG than CA women at all BMI. Obese and diabetic AA women had significantly lower apoB levels than CA women when compared to their respective counterparts. For AA women, fasting ASP was positively correlated with BMI, cholesterol, apoB, LDL-C and glucose. For CA women, fasting ASP was positively correlated with BMI, leptin, glucose and insulin. However, for any given BMI, ASP was significantly reduced in AA vs CA (p = 0.0004. Similarly, for any given leptin level or TG levels, ASP was significantly lower in AA women (p = 0.041 and p = 0.003, respectively. Conclusion CA women have higher baseline TG levels and an earlier TG peak that is accompanied with higher ASP levels suggesting increased ASP resistance, while AA women have lower baseline TG levels and a later TG peak at lower ASP levels suggesting increased ASP sensitivity. This may explain why AA women may have fewer metabolic complications, such as diabetes and CVD, when compared to their Caucasian counterparts at the same level of obesity.

  14. Adiponectin, Leptin, and Chemerin in Elderly Patients with Type 2 Diabetes Mellitus: A Close Linkage with Obesity and Length of the Disease

    Science.gov (United States)

    Brandão Proença, Jorge; Neuparth, Maria João

    2014-01-01

    Obesity, insulin resistance, and aging are closely associated and adipokines seem to have a crucial role in their pathophysiology. We aim to study the relationship between aging and chemerin, adiponectin, and leptin levels in type 2 diabetes mellitus (T2DM). Age correlated positively with chemerin and leptin and inversely with adiponectin. Body mass index (BMI) correlated positively with leptin (in males) and chemerin and inversely with adiponectin. The patients with ≥65 years (n = 34) showed significantly higher leptin and chemerin and lower adiponectin levels than middle-aged (38–64 years) patients (n = 39) and controls (n = 20). After statistical adjustment for length of disease, there was a loss of significance, between T2DM groups, for adiponectin and, in female, for leptin. In the older group, BMI correlated with adiponectin and with leptin, but not with chemerin. Adiponectin and leptin levels in elderly T2DM patients seem to be closely linked to obesity and to length of the disease. In elderly T2DM patients, chemerin concentrations are increased and seem to be independent of length of disease and BMI, suggesting that adipocyte dysfunction is enhanced with aging. The understanding of the glucose homeostasis impairment in the elderly is mandatory in order to achieve ways to improve their quality of life and longevity. PMID:25105135

  15. Comparison of serum leptin, glucose, total cholesterol and total protein levels in fertile and repeat breeder cows

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    Saime Guzel

    2014-12-01

    Full Text Available In the present study we measured serum glucose, leptin, total cholesterol and total protein concentrations in repeat breeder cows and compared them with fertile cows. For this aim, 20 repeat breeder cows and 20 fertile cows were used as material. Repeat breeder cows were found to have lower levels of leptin and glucose as compared with fertile ones. No significant differences in total cholesterol and total protein levels were observed between the two groups. No significant correlation of leptin with glucose, total cholesterol and total protein was observed in fertile and repeat breeder cows. Low concentrations of glucose and leptin can have some effects on reproductive problems as repeat breeder and help to understand potential mechanisms impairing fertility in repeat breeder cows.

  16. Role of leptin in blood pressure regulation and arterial hypertension.

    Science.gov (United States)

    Bełtowski, Jerzy

    2006-05-01

    Leptin is a 16-kDa protein secreted by white adipose tissue that is primarily involved in the regulation of food intake and energy expenditure. Plasma leptin concentration is proportional to the amount of adipose tissue and is markedly increased in obese individuals. Recent studies suggest that leptin is involved in cardiovascular complications of obesity, including arterial hypertension. Acutely administered leptin has no effect on blood pressure, probably because it concomitantly stimulates the sympathetic nervous system and counteracting depressor mechanisms such as natriuresis and nitric oxide (NO)-dependent vasorelaxation. By contrast, chronic hyperleptinemia increases blood pressure because these acute depressor effects are impaired and/or additional sympathetic nervous system-independent pressor effects appear, such as oxidative stress, NO deficiency, enhanced renal Na reabsorption and overproduction of endothelin. Although the cause-effect relationship between leptin and high blood pressure in humans has not been demonstrated directly, many clinical studies have shown elevated plasma leptin in patients with essential hypertension and a significant positive correlation between leptin and blood pressure independent of body adiposity both in normotensive and in hypertensive individuals. In addition, leptin may contribute to end-organ damage in hypertensive individuals such as left ventricular hypertrophy, retinopathy and nephropathy, independent of regulating blood pressure. Here, current knowledge about the role of leptin in the regulation of blood pressure and in the pathogenesis of arterial hypertension is presented.

  17. Genetics Home Reference: congenital leptin deficiency

    Science.gov (United States)

    ... Description Congenital leptin deficiency is a condition that causes severe obesity beginning in the first few months of life. ... are unknown. Congenital leptin deficiency is a rare cause of obesity. Researchers are studying the factors involved in more ...

  18. Leptin deficiency in mice counteracts imiquimod (IMQ)-induced psoriasis-like skin inflammation while leptin stimulation induces inflammation in human keratinocytes.

    Science.gov (United States)

    Stjernholm, Theresa; Ommen, Pernille; Langkilde, Ane; Johansen, Claus; Iversen, Lars; Rosada, Cecilia; Stenderup, Karin

    2017-04-01

    Leptin is an adipocyte-derived cytokine secreted mostly by adipose tissue. Serum leptin levels are elevated in obese individuals and correlate positively with body mass index (BMI). Interestingly, serum leptin levels are also elevated in patients with psoriasis and correlate positively with disease severity. Psoriasis is associated with obesity; patients with psoriasis have a higher incidence of obesity, and obese individuals have a higher risk of developing psoriasis. Additionally, obese patients with psoriasis experience a more severe degree of psoriasis. In this study, we hypothesised that leptin may link psoriasis and obesity and plays an aggravating role in psoriasis. To investigate leptin's role in psoriasis, we applied the widely accepted imiquimod (IMQ)-induced psoriasis-like skin inflammation mouse model on leptin-deficient (ob/ob) mice and evaluated psoriasis severity. Moreover, we stimulated human keratinocytes with leptin and investigated the effect on proliferation and expression of pro-inflammatory proteins. In ob/ob mice, clinical signs of erythema, infiltration and scales in dorsal skin and inflammation in ear skin, as measured by ear thickness, were attenuated and compared with wt mice. Moreover, IL-17A and IL-22 mRNA expression levels, as well as increased epidermal thickness, were significantly less induced. In vitro, the effect of leptin stimulation on human keratinocytes demonstrated increased proliferation and induced secretion of several pro-inflammatory proteins; two hallmarks of psoriasis. In conclusion, leptin deficiency attenuated IMQ-induced psoriasis-like skin inflammation in a mouse model, and leptin stimulation induced a pro-inflammatory phenotype in human keratinocytes, thus, supporting an aggravating role of leptin in psoriasis. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. A strong association between biologically active testosterone and leptin in non-obese men and women is lost with increasing (central) adiposity.

    Science.gov (United States)

    Söderberg, S; Olsson, T; Eliasson, M; Johnson, O; Brismar, K; Carlström, K; Ahrén, B

    2001-01-01

    In both humans and rodents, males have lower levels of leptin than females at any level of adiposity. Experimental data support the idea that testosterone exerts a negative influence on leptin levels. There are, however, major inconsistencies in available data concerning the possible association between androgenicity and leptin in humans. Reasons could be the influence of androgenicity on leptin production being dependent on body composition, and incomplete measures of biologically active testosterone levels. In the present study we have characterized the relationship between biologically active testosterone and leptin after careful stratification for gender and adiposity. Healthy subjects (n=158; 85 men and 73 pre- and postmenopausal women) from the Northern Sweden MONICA (Monitoring of Trends and Determinants in Cardiovascular Disease) population were studied with a cross-sectional design. Anthropometric measurements (body mass index (BMI) and waist circumference) and oral glucose tolerance tests were performed. Circulating levels of leptin, insulin, testosterone, androstenedione, sex hormone-binding globulin (SHBG) and insulin-like growth factor-1 (IGF-1) were measured by radioimmunoassays or microparticle enzyme immunoassays. Apparent concentrations of free testosterone and non-SHBG-bound testosterone were calculated. After adjustments for age, BMI and insulin, leptin levels were inversely correlated to testosterone levels in non-obese men (r=-0.56, Ptestosterone correlated in a positive manner in non-obese women (r=0.59, Plow waist circumference (r=-0.59, Plow levels of biologically active testosterone and SHBG in men with low and medium waist circumference, insulin in men with high waist circumference, high levels of testosterone and insulin in non-obese women, and BMI in obese women. We conclude that low leptin levels are associated with androgenicity in non-obese men and women and that the direction of this association is dependent on gender and body fat

  20. Androgen receptor CAG repeat polymorphism is associated with serum testosterone levels, obesity and serum leptin in men with type 2 diabetes.

    Science.gov (United States)

    Stanworth, R D; Kapoor, D; Channer, K S; Jones, T H

    2008-12-01

    To determine the relationships between androgen receptor CAG repeat polymorphism length (AR CAG), sex hormones and clinical variables in men with type 2 diabetes (DM2). Men with DM2 are known to have a high prevalence of low testosterone levels. Studies suggest that testosterone replacement therapy may improve insulin sensitivity and glycaemic control in men with DM2 and reduces central obesity and serum leptin. AR CAG is known to correlate negatively with AR sensitivity and positively with body fat, insulin levels, and leptin in healthy men. Cross-sectional study set in a district general hospital diabetes centre. Sex hormones, AR CAG and symptoms of hypogonadism were assessed in 233 men with DM2. Associations were sought between these variables and others such as obesity, leptin, glycaemic control, and blood pressure. Testosterone was negatively associated and AR CAG positively associated with obesity and leptin. The associations of AR CAG with leptin and obesity were independent of testosterone, estradiol, gonadotropins, and age. AR CAG was also independently associated with total, bioavailable and free testosterone, LH, waist circumference, body mass index, leptin, and systolic blood pressure. There was no association of AR CAG with sex hormone binding globulin, estradiol, HbA(1C) or the symptoms of hypogonadism. The association of longer AR CAG with obesity and leptin suggests that shorter AR CAG may have an influence in maintaining healthy anthropomorphics and metabolism in men with DM2. Testosterone and LH levels are higher in men with longer AR CAG, probably reflecting reduced negative feedback through a less sensitive receptor.

  1. The association of asthma, nasal allergies, and positive skin prick tests with obesity, leptin, and adiponectin

    DEFF Research Database (Denmark)

    Newson, R. B.; Jones, M.; Forsberg, B.

    2014-01-01

    measures of fatness including body mass index and waist/hip ratio, current asthma, and specific skin prick and IgE sensitisation. We used inverse sampling-probability-weighted rank and regression statistics to measure population associations of disease outcomes with adipokines in males and females......, adjusting for confounders (area, age, smoking history, and number of elder siblings) and also mutually adjusting associations with adipokines and fatness measures. ResultsOne thousand nine hundred and fifty-five subjects aged 16-77years had information on leptin or adiponectin levels. Leptin and leptin...

  2. The influence of childhood protein energy malnutrition on serum ghrelin and leptin levels

    International Nuclear Information System (INIS)

    Mostafa, A.M.

    2007-01-01

    Protein-energy malnutrition (PEM) is a clinical problem caused by inadequate intake of one or more nutritional elements and remains as one of the most important health problems in developing countries. The aim of this study is to investigate the influence of PEM on ghrelin and leptin levels and to determine the relationships of ghrelin and leptin concentrations with anthropometric measurements in malnourished children. The study group consisted of 24 infants diagnosed as PEM. They were classified into marasmic group (10), kwashiorkor group (8) and marasmic kwashiorkor group (b). Ten healthy infants were enrolled as the control group. Serum ghrelin was evaluated by enzyme linked immuno absorbent assay (ELISA) while serum leptin was determined by radioimmunoassay (RIA). Patients with PEM established a significantly lower midarm circumference, skin fold thickness, (W/A) Z, (W/H) Z, BMI, total proteins, serum albumin, cholesterol and triglycerides compared with the age-matched control group. Markedly elevated mean serum ghrelin levels (448.7± 185.82, 293.83±155.02 and 354.1±90.1 vs 20.97± 8.61 pg/ml, p

  3. Zinc, vitamin A, and vitamin C status are associated with leptin concentrations and obesity in Mexican women: results from a cross-sectional study

    Directory of Open Access Journals (Sweden)

    García Olga

    2012-06-01

    Full Text Available Abstract Background The prevalence of obesity among Mexican women is high and it could be related to micronutrient status. We evaluated in a cross-sectional study the associations of zinc and vitamins A, C and E concentrations with BMI, central adiposity, body fat and leptin concentration. Methods Women aged 37 ± 7.5 years (n = 580 from 6 rural communities in Mexico were evaluated. Anthropometric measurements included weight, height, waist and hip circumference. A fasting blood sample was taken for the analysis of glucose, lipid profile, leptin, zinc, and vitamins A, C and E. Body composition was determined by DEXA (Hologic Mod Explorer. Results The prevalence of overweight and obesity was 36% (BMI > 25 Kg/m2 and 44% (BMI > 30 Kg/m2, respectively. Prevalence of zinc and vitamins C and E deficiencies were similar in obese, overweight and normal weight women. No vitamin A deficiency was found. Vitamin C was negatively associated with BMI, waist-to-height ratio, and leptin concentrations (p . Vitamin A was positively associated with leptin (p  Conclusion Zinc and vitamins A and C are associated with obesity, adiposity and leptin concentration in women from rural Mexico, and may play an important role in fat deposition. The causality of these associations needs to be confirmed.

  4. Is there a role for leptin in the reduction of depression symptoms during weight loss therapy in obese adolescent girls and boys?

    Science.gov (United States)

    de Carvalho-Ferreira, Joana Pereira; Masquio, Deborah Cristina Landi; da Silveira Campos, Raquel Munhoz; Dal Molin Netto, Bárbara; Corgosinho, Flavia Campos; Sanches, Priscila L; Tock, Lian; Tufik, Sergio; de Mello, Marco Túlio; Finlayson, Graham; Dâmaso, Ana R

    2015-03-01

    Several studies have sought to clarify the association between adolescent obesity and psychological distress. Recently, a biological link between leptin resistance and depression has been proposed. The aim of the present study was to examine changes in leptin concentrations as a potential predictor of reduced depression symptoms in obese adolescents during long-term interdisciplinary weight loss therapy. Seventy-five obese adolescents (age: 16.28±2.37 years; BMI: 35.65±4.64 kg/m2) engaged in a long-term interdisciplinary therapy for weight loss. They were evaluated at baseline and after 1 year of treatment for body composition, serum analyses and depression symptomatology. After therapy, body mass BMI, fat mass (% and kg), waist circumference, visceral, subcutaneous and visceral/subcutaneous fat and depression symptoms decreased and lean mass (%) increased significantly. There was an improvement in inflammatory profiles with a significant reduction in leptin and increase in adiponectin. Regression analyses showed that decreased leptin predicted amelioration in depression symptoms independent of age, gender and changes in visceral fat, body mass, fat mass (%) and leptin/adiponectin ratio. These associations appear stronger in girls than boys. The attenuation of hyperleptinemia appears to play an important role in the association between weight loss and depression, particularly in obese girls. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Influence of a monitored aerobic training and a low-energy diet on serum leptin concentration in obese women

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    K Sempolska

    2003-03-01

    Full Text Available The study focused on the influence of a 9-week monitored energy deficit on serum leptin level in 16 obese women. Additionally, measurements of body components and total cholesterol (CHO, HDL cholesterol (HDL and triacylglycerols (TRG concentration in blood were carried out, concentration of LDL cholesterol (LDL was evaluated. Energy deficit was induced by a diet and “fat burning” type exercises. Leptin concentration in blood serum was significantly higher before (41.7±16.5 ng/ml than after the accomplishment of experiment (24.7±16.2 ng/ml. Body mass decreased, which was mainly due to a drop in body fat (from 36.6±13.9 kg to 29.0±12.5 kg. All changes have been statistically significant at the level of P<0.001. A significant decrease of CHO (from 187.9±26.3 mg/dl to 167.1±25.4 mg/dl; P<0.001 and LDL (from 115.5±25.1 mg/dl to 102.3±21.5 mg/dl; P<0.05 concentration in blood was noticed. However, changes in HDL and TRG concentration were statistically insignificant. There was a statistically significant correlation (P<0.05 recorded between changes in leptin concentration in blood and changes in body mass, BMI and body fat (0.51; 0.58; 0.64 respectively. No correlation was observed between leptin and lean body mass, CHO, HDL, LDL or TRG.

  6. Genistein Precipitated Hypothyroidism, Altered Leptin and C-Reactive Protein Synthesis in Pregnant Rats.

    Science.gov (United States)

    Awobajo, F O; Onokpite, B O; Ali, Y M; Babaleye, T A; Uzor, P O; Tijani, K O

    2015-12-20

    Genistein is an isoflavone constituent of soya. This study examined the mechanism by which genistein produced adverse effects in pregnant laboratory rats. Pregnant rats were divided into control (Con) and genistein (Gen) force fed (2 mg/kg) groups. At terminal gestation day (GD) ranging from 0-20, the rats were sacrificed, and blood samples and amniotic fluids were collected. Thyroid hormone, C-reactive protein (CRP) and leptin assay was carried using the blood samples. Leptin was also assayed in the placenta and amniotic fluid supernatant. Oral exposure of pregnant rats to genistein significantly altered maternal T3, (GD18; Con 1.65 ± 0.01, Gen 1.03 ± 0.04 nmol/L), T4 (GD6; Con 29.60 ± 0.00, Gen 36.04 ± 1.29 nmol/L), Leptin (Placenta GD20; Con 0.08 ± 0.01, Gen 0.31 ± 0.02 ng/ml, amniotic fluid ;GD 20; Con 0.02 ± 0.00, Gen 0.35 ± 0.05 ng/ml) in genistein group. These changes were accompanied with loss of embryonic implants and a decrease in fetal and placental weights. The CRP level was significantly decreased and increased at the onset and toward late pregnancy respectively. Oral exposure of pregnant rats to genistein precipitated hypothyroidism, altered some metabolic hormones with a reduction in fetal and placental growth and increased resorption of embryonic implants.

  7. Assessment of leptin and resistin levels in non-obese multiple myeloma patients and their relation with Ig level and disease stage

    International Nuclear Information System (INIS)

    Esheba, N.E.; Shahba, A.; El Shora, O.

    2014-01-01

    Introduction: Multiple myeloma (MM) accounts for approximately 0.8% of all cancer diagnoses and 0.9% of cancer deaths. Leptin receptors were expressed on CD34 + cells. Resistin receptors were expressed on inflammatory cells and pro-inflammatory cytokines increase the expression of resistin on monocytes. Aim of work: To assess the level of leptin and resistin in non-obese multiple myeloma patients and to study their relation with Ig level and disease stage. Subjects and methods: 32 subjects were included; 16 patients diagnosed with MM and 16 healthy individuals served as control. All were subjected to history taking, clinical examination, routine laboratory investigations and leptin and resistin blood level. Laboratory investigations were done for diagnosis and staging for MM patients. Results: Leptin was significantly higher in MM patients compared with the control group, unlike resistin which showed no significant difference between the two groups. A significant positive relation was found between IgG level and leptin. Similarly, a significant difference in leptin level has been observed between stage I and stage II (higher in II). Conclusions: Leptin may play a role in the pathogenesis of MM and its level may be changed in different stages.

  8. Leptin stimulates both endothelin-1 and nitric oxide activity in lean subjects but not in patients with obesity-related metabolic syndrome.

    Science.gov (United States)

    Schinzari, Francesca; Tesauro, Manfredi; Rovella, Valentina; Di Daniele, Nicola; Mores, Nadia; Veneziani, Augusto; Cardillo, Carmine

    2013-03-01

    Leptin has nitric oxide (NO)-dependent vasodilator actions, but hyperleptinemia is an independent risk factor for cardiovascular disease. The objective of the study was to investigate whether, in the human circulation, properties of leptin to release NO are opposed by stimulation of vasculotoxic substances, such as endothelin (ET)-1, and whether this mechanism might contribute to vascular damage in hyperleptinemic states like obesity. Forearm blood flow responses (plethysmography) to ETA receptor antagonism (BQ-123, 10 nmol/min) and NO synthase inhibition [N(G)-monomethyl L-arginine (L-NMMA), 4 μmol/min] were assessed before and after intraarterial administration of leptin (2 μg/min) in lean controls (n = 8) and patients with obesity-related metabolic syndrome (MetS; n = 8). Baseline plasma leptin was higher in patients than in controls (P .05 vs before). These findings indicate that, under physiological conditions, leptin stimulates both ET-1 and NO activity in the human circulation. This effect is absent in hyperleptinemic patients with the MetS who are unresponsive to additional leptin. In these patients, therefore, hyperleptinemia may be a biomarker of vascular dysfunction, rather than a mediator of vascular damage.

  9. Phosphodiesterase-3B-cAMP pathway of leptin signalling in the hypothalamus is impaired during the development of diet-induced obesity in FVB/N mice.

    Science.gov (United States)

    Sahu, M; Anamthathmakula, P; Sahu, A

    2015-04-01

    The phosphodiesterase-3B (PDE3B)-cAMP pathway plays an important role in transducing the action of leptin in the hypothalamus. Obesity is usually associated with hyperleptinaemia and resistance to anorectic and body weight-reducing effects of leptin. To determine whether the hypothalamic PDE3B-cAMP pathway of leptin signalling is impaired during the development of diet-induced obesity (DIO), we fed male FVB/N mice a high-fat diet (HFD: 58% kcal as fat) or low-fat diet (LFD: 6% kcal as fat) for 4 weeks. HFD fed mice developed DIO in association with hyperphagia, hyperleptinaemia and hyperinsulinaemia. Leptin (i.p.) significantly increased hypothalamic PDE3B activity and phosphorylated (p)-Akt levels in LFD-fed but not in HFD-fed mice. However, basal p-Akt levels in hypothalamus were increased in DIO mice. Additionally, amongst six-microdissected brain nuclei examined, leptin selectively decreased cAMP levels in the arcuate nucleus (ARC) of LFD-fed mice but failed to do so in HFD-fed mice. We next tested whether both the PBE3B and Akt pathways of leptin signalling remained impaired in DIO mice on the HFD for 12 weeks (long-term). DIO mice were hyperinsulinaemic and hyperleptinaemic in association with impaired glucose and insulin tolerance. Although, in LFD-fed mice, leptin significantly increased PDE3B activity and p-Akt levels in the hypothalamus, it failed to do so in HFD-fed mice. Also, basal p-Akt levels in the hypothalamus were increased in DIO mice and leptin had no further effect. Similarly, immunocytochemistry showed that leptin increased the number of p-Akt-positive cells in the ARC of LFD-fed but not in HFD-fed mice, and there was an increased basal number of p-Akt positive cells in the ARC of DIO mice. These results suggest that the PDE3B-cAMP- and Akt-pathways of leptin signalling in the hypothalamus are impaired during the development of DIO. Thus, a defect in the regulation by leptin of the hypothalamic PDE3B-cAMP pathway and Akt signalling may be one

  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. The obesity paradox in men with coronary heart disease and heart failure: the role of muscle mass and leptin.

    Science.gov (United States)

    Wannamethee, S Goya; Shaper, A Gerald; Whincup, Peter H; Lennon, Lucy; Papacosta, Olia; Sattar, Naveed

    2014-01-15

    We have investigated the role of muscle mass, natriuretic peptides and adipokines in explaining the obesity paradox. The obesity paradox relates to the association between obesity and increased survival in patients with coronary heart disease (CHD) or heart failure (HF). Prospective study of 4046 men aged 60-79 years followed up for a mean period of 11 years, during which 1340 deaths occurred. The men were divided according to the presence of doctor diagnosed CHD and HF: (i) no CHD or HF ii), with CHD (no HF) and (iii) with HF. Overweight (BMI 25-9.9 kg/m(2)) and obesity (BMI ≥ 30 kg/m(2)) were associated with lower mortality risk compared to men with normal weight (BMI 18.5-24.9 kg/m(2)) in those with CHD [hazards ratio (HR) 0.71 (0.56,0.91) and 0.77 (0.57,1.04); p=0.04 for trend] and in those with HF [HR 0.57 (0.28,1.16) and 0.41 (0.16,1.09; p=0.04 for trend). Adjustment for muscle mass and NT-proBNP attenuated the inverse association in those with CHD (no HF) [HR 0.78 (0.61,1.01) and 0.96 (0.68,1.36) p=0.60 for trend) but made minor differences to those with HF [p=0.05]. Leptin related positively to mortality in men without HF but inversely to mortality in those with HF; adjustment for leptin abolished the BMI mortality association in men with HF [HR 0.82 (0.31,2.20) and 0.99 (0.27,3.71); p=0.98 for trend]. The lower mortality risk associated with excess weight in men with CHD without HF may be due to higher muscle mass. In men with HF, leptin (possibly reflecting cachexia) explain the inverse association. Copyright © 2013. Published by Elsevier Ireland Ltd.

  12. Correlation of insulin resistance with serum C-reactive protein, adiponectin and leptin levels in patients with type 2 diabetes

    International Nuclear Information System (INIS)

    Duan Yangqiang; Wang Zuobing; Yu Hui

    2012-01-01

    Objective: To explore the relationship between serum C-reactive protein (CRP), adiponectin (APN), leptin (Leptin) levels, insulin resistance index (HOMA-IR) and type 2 diabetes mellitus (T2DM) disease susceptibility. Methods: The plasma leptin and insulin (FINS) levels in the DM patients were determined by RIA, and the serum ANP levels were determined by ELSIA. The CRP, conventional serum fasting plasma glucose (FPG) levels were determine by automatic biochemistry analyzer. The insulin resistance index (HOMA-IR, FPG x FINS/22.5) was calculated. The result was analyzed with normal healthy control group. Results: The serum CRP and leptin, HOMA-IR levels in T2DM group were significantly higher than that of in control group (P< 0.01), and the serum ANP was significantly lower than in control group (P<0.01). The HOMA-IR in T2DM was positively correlated with serum CRP (r= 0.36, P<0.05) and leptin(r= 0.39, P<0.05), and was negatively correlated with serum APN (r=0.32, P<0.05). Conclusion: The high serum CRP and leptin and low APN levels hyperlipidaemia might be factors for diabetes, and their metabolic disorders may be closely related with insulin resistance in patients with type 2 diabetes. (authors)

  13. The photo biological effect of low level laser therapy on serum level of leptin, cholesterol and triglycerides in overweight and obese females

    International Nuclear Information System (INIS)

    Salem, E.S.; Tawfik, M.S.; Youssef, S.S.; Serry, Z.M.; Aboel magd, H.F.

    2013-01-01

    The use of low level laser for body contouring and weight reduction depends on the photochemical non thermal effect of laser light on the adipose tissue. LLLT was reported to liquefy or release stored fat in adipocytes by the opening of specialized yet not identified cell membrane-associated pores after a brief treatment The concentration of leptin in adipose tissue and serum closely parallel the mass of adipose tissue and adipocyte size and triglycerides content. Thus, leptin increases in obesity and falls with weight loss. The current study was conducted to evaluate the effect of the low level laser therapy (LLLT) on leptin hormone, Cholesterol and triglyceride in both overweight and obese females. Twenty women were included in this study. Their ages ranged from 30-40 years. They were divided into two equal groups. Group A (Overweight group): included 10 females with BMI between 25 and 29.9 Kg/m2 -Group B (Obese group): included 10 females with BMI . 30. Both groups received LLL to the abdomen using laser scanner for uniform distribution of the beam above and below the umbilicus. Duration of treatment was 30 minutes, 2 times per week for 8 weeks as a total period of treatment. Serum level of leptin was estimated by radioimmunoassay (RIA). As regards serum cholesterol and triglyceride they were determined by enzymatic colorimetric test. Biochemical assessments were done before and after treatment. Results of the present study showed that in the overweight group laser treatment resulted in highly significant reduction in leptin serum level accompanied by highly significant increase in serum triglycerides level. Meanwhile, the increase in cholesterol level was insignificant. As regards the obese group, alteration in serum leptin level caused by laser treatment was not significant. In this group the increase in triglycerides and cholesterol serum levels after treatment were highly significant

  14. Common genetic variation in the SERPINF1 locus determines overall adiposity, obesity-related insulin resistance, and circulating leptin levels.

    Directory of Open Access Journals (Sweden)

    Anja Böhm

    Full Text Available OBJECTIVE: Pigment epithelium-derived factor (PEDF belongs to the serpin family of peptidase inhibitors (serpin F1 and is among the most abundant glycoproteins secreted by adipocytes. In vitro and mouse in vivo data revealed PEDF as a candidate mediator of obesity-induced insulin resistance. Therefore, we assessed whether common genetic variation within the SERPINF1 locus contributes to adipose tissue-related prediabetic phenotypes in humans. SUBJECTS/METHODS: A population of 1,974 White European individuals at increased risk for type 2 diabetes was characterized by an oral glucose tolerance test with glucose and insulin measurements (1,409 leptin measurements and genotyped for five tagging SNPs covering 100% of common genetic variation (minor allele frequency ≥ 0.05 in the SERPINF1 locus. In addition, a subgroup of 486 subjects underwent a hyperinsulinaemic-euglycaemic clamp and a subgroup of 340 magnetic resonance imaging (MRI and spectroscopy (MRS. RESULTS: After adjustment for gender and age and Bonferroni correction for the number of SNPs tested, SNP rs12603825 revealed significant association with MRI-derived total adipose tissue mass (p = 0.0094 and fasting leptin concentrations (p = 0.0035 as well as nominal associations with bioelectrical impedance-derived percentage of body fat (p = 0.0182 and clamp-derived insulin sensitivity (p = 0.0251. The association with insulin sensitivity was completely abolished by additional adjustment for body fat (p = 0.8. Moreover, the fat mass-increasing allele of SNP rs12603825 was significantly associated with elevated fasting PEDF concentrations (p = 0.0436, and the PEDF levels were robustly and positively associated with all body fat parameters measured and with fasting leptin concentrations (p<0.0001, all. CONCLUSION: In humans at increased risk for type 2 diabetes, a functional common genetic variant in the gene locus encoding PEDF contributes to overall body adiposity

  15. Fasting leptin and glucose in normal weight, over weight and obese men and women diabetes patients with and without clinical depression.

    Science.gov (United States)

    Haleem, Darakhshan Jabeen; Sheikh, Shehnaz; Fawad, Asher; Haleem, Muhammad A

    2017-06-01

    A large number of diabetes patients suffer from major depression and are at high risk of mortality. In view of a role of leptin in diabetes, depression and energy homeostasis, the present study concerns circulating levels of leptin in different BMI groups of un-depressed and depressed diabetes patients. Six hundred thirty male and female patients with a primary diagnosis of diabetes were grouped according to BMI and with or without clinical symptoms of depression. Age matched healthy, normal weight male and female volunteers without clinical symptoms of depression or diabetes were taken as controls. Blood samples were obtained after an overnight fast of 12 h. Serum was stored for the determination of leptin and glucose. We found that there were more female than male diabetes patients with comorbid depression. Fasting leptin was higher in normal weight non-diabetes women than men; but comparable in normal weight men and women diabetes patients. Fasting glucose levels were higher in diabetes than non diabetes groups; values were comparable in men and women. Depression was associated with a decrease and increase in leptin respectively in normal-overweight and obese men and women diabetes patients. Glucose levels were also higher in obese depressed than un-depressed diabetes patients. The results suggested that the female gender is at greater risk to comorbid diabetes with depression. Adipo-insular axis plays an important role in diabetes, associated depression and in the greater risk of the female gender to comorbid diabetes with depression.

  16. Leptin-Induced CART (Cocaine- and Amphetamine-Regulated Transcript) Is a Novel Intraovarian Mediator of Obesity-Related Infertility in Females

    Science.gov (United States)

    Ma, Xiaoting; Hayes, Emily; Prizant, Hen; Srivastava, Rajesh K.; Hammes, Stephen R.

    2016-01-01

    Obesity is considered detrimental to women's reproductive health. Although most of the attention has been focused on the effects of obesity on hypothalamic function, studies suggest a multifactorial impact. In fact, obesity is associated with reduced fecundity even in women with regular cycles, indicating that there may be local ovarian effects modulating fertility. Here we describe a novel mechanism for leptin actions directly in the ovary that may account for some of the negative effects of obesity on ovarian function. We find that normal cycling, obese, hyperleptinemic mice fed with a high-fat diet are subfertile and ovulate fewer oocytes compared with animals fed with a normal diet. Importantly, we show that leptin induces expression of the neuropeptide cocaine- and amphetamine-regulated transcript (CART) in the granulosa cells (GCs) of ovarian follicles both in vitro and in vivo. CART then negatively affects intracellular cAMP levels, MAPK signaling, and aromatase mRNA expression, which leads to lower estradiol synthesis in GCs and altered ovarian folliculogenesis. Finally, in human samples from patients undergoing in vitro fertilization, we show a significant positive correlation between patient body mass index, CART mRNA expression in GCs, and CART peptide levels in follicular fluid. These observations suggest that, under obese conditions, CART acts as a local mediator of leptin in the ovary to cause ovarian dysfunction and reduced fertility. PMID:26730935

  17. Leptin-Induced CART (Cocaine- and Amphetamine-Regulated Transcript) Is a Novel Intraovarian Mediator of Obesity-Related Infertility in Females.

    Science.gov (United States)

    Ma, Xiaoting; Hayes, Emily; Prizant, Hen; Srivastava, Rajesh K; Hammes, Stephen R; Sen, Aritro

    2016-03-01

    Obesity is considered detrimental to women's reproductive health. Although most of the attention has been focused on the effects of obesity on hypothalamic function, studies suggest a multifactorial impact. In fact, obesity is associated with reduced fecundity even in women with regular cycles, indicating that there may be local ovarian effects modulating fertility. Here we describe a novel mechanism for leptin actions directly in the ovary that may account for some of the negative effects of obesity on ovarian function. We find that normal cycling, obese, hyperleptinemic mice fed with a high-fat diet are subfertile and ovulate fewer oocytes compared with animals fed with a normal diet. Importantly, we show that leptin induces expression of the neuropeptide cocaine- and amphetamine-regulated transcript (CART) in the granulosa cells (GCs) of ovarian follicles both in vitro and in vivo. CART then negatively affects intracellular cAMP levels, MAPK signaling, and aromatase mRNA expression, which leads to lower estradiol synthesis in GCs and altered ovarian folliculogenesis. Finally, in human samples from patients undergoing in vitro fertilization, we show a significant positive correlation between patient body mass index, CART mRNA expression in GCs, and CART peptide levels in follicular fluid. These observations suggest that, under obese conditions, CART acts as a local mediator of leptin in the ovary to cause ovarian dysfunction and reduced fertility.

  18. Leptin interferes with 3',5'-Cyclic Adenosine Monophosphate (cAMP signaling to inhibit steroidogenesis in human granulosa cells

    Directory of Open Access Journals (Sweden)

    HoYuen Basil

    2009-10-01

    Full Text Available Abstract Background Obesity has been linked to an increased risk of female infertility. Leptin, an adipocytokine which is elevated during obesity, may influence gonadal function through modulating steroidogenesis in granulosa cells. Methods The effect of leptin on progesterone production in simian virus 40 immortalized granulosa (SVOG cells was examined by Enzyme linked immunosorbent assay (ELISA. The effect of leptin on the expression of the steroidogenic enzymes (StAR, P450scc, 3betaHSD in SVOG cells was examined by real-time PCR and Western blotting. The mRNA expression of leptin receptor isoforms in SVOG cells were examined by using PCR. SVOG cells were co-treated with leptin and specific pharmacological inhibitors to identify the signaling pathways involved in leptin-reduced progesterone production. Silencing RNA against leptin receptor was used to determine that the inhibition of leptin on cAMP-induced steroidogenesis acts in a leptin receptor-dependent manner. Results and Conclusion In the present study, we investigated the cellular mechanisms underlying leptin-regulated steroidogenesis in human granulosa cells. We show that leptin inhibits 8-bromo cAMP-stimulated progesterone production in a concentration-dependent manner. Furthermore, we show that leptin inhibits expression of the cAMP-stimulated steroidogenic acute regulatory (StAR protein, the rate limiting de novo protein in progesterone synthesis. Leptin induces the activation of ERK1/2, p38 and JNK but only the ERK1/2 (PD98059 and p38 (SB203580 inhibitors attenuate the leptin-induced inhibition of cAMP-stimulated StAR protein expression and progesterone production. These data suggest that the leptin-induced MAPK signal transduction pathway interferes with cAMP/PKA-stimulated steroidogenesis in human granulosa cells. Moreover, siRNA mediated knock-down of the endogenous leptin receptor attenuates the effect of leptin on cAMP-induced StAR protein expression and progesterone

  19. Time course and determinants of leptin decline during weight loss in obese boys and girls

    DEFF Research Database (Denmark)

    Holm, Jens-Christian; Gamborg, Michael; Kaas-Ibsen, Karsten

    2007-01-01

    measures during a 12-week weight loss programme. SUBJECTS: Fifty-three boys and 62 girls (7.9-15.2 years) with body mass index (BMI) standard deviation scores (SDS) of median 2.78 and 2.70, respectively. MEASUREMENTS: Height, weight, fat mass percentage assessed by bioimpedance, Tanner stages, testicular......, puberty, baseline adiposity or concomitant changes in BMI SDS, fat mass percentage, rate of weight loss, physical activity scores or insulin concentrations. CONCLUSION: The biphasic leptin decline, which exceeded the level expected, was independent of puberty, baseline adiposity and changes in adiposity......OBJECTIVE: To investigate whether changes in leptin concentrations during weight loss can be explained by gender, puberty, baseline adiposity and changes in adiposity, body composition, rate of weight loss, physical activity and insulin concentrations. DESIGN: A longitudinal study with 9 repeated...

  20. Leptin hormone in obese and non-obese stable and exacerbated cases of chronic obstructive pulmonary disease

    OpenAIRE

    Mahmoud, Ahmad Elsayed; Omar, Magdy Mohammed; Abdelghaffar Hibah, Nabil A.; Issa, Hisham Ali

    2015-01-01

    Objective: The aim of this study was to assess the level of serum leptin hormone in chronic obstructive pulmonary disease patients during acute exacerbation and in stable conditions and also, to determine if these changes correlate with changes in the ventilatory functions. Methods: Sixty cases were included in this prospective study (40 COPD patients and 20 age related smokers without symptoms or signs of COPD and within normal pulmonary functions as a control). Patients and control were ...

  1. Serum Leptin and Skeletal Differences between Obese and Non-Obese Patients with Chronic Obstructive Pulmonary Disease

    OpenAIRE

    Koršić, Marta; Kušec, Vesna

    2014-01-01

    Objective: Chronic obstructive pulmonary disease (COPD) affects body composition, adipokine secretion, and skeletal integrity. The aim was to determine the association between leptin, body mass (BM) and body composition parameters - fat mass (FM) and fat mass index (FMI), lean tissue mass (LTM), lean tissue mass index (LTMI) and bone mineral density (BMD) in 67 male COPD patients. Methods: BM, body composition and biochemical indicators were measured or calculated using standard methods. Data...

  2. Amylin/leptin synergy is absent in extreme obesity and not restored by calorie restriction-induced weight loss in rats.

    Science.gov (United States)

    Trevaskis, J L; Wittmer, C; Athanacio, J; Griffin, P S; Parkes, D G; Roth, J D

    2016-12-01

    Co-administration of amylin and leptin induces synergistic and clinically meaningful (>10%) weight loss that is attenuated as the degree of obesity increases. We explored whether calorie restriction (CR) could restore amylin/leptin synergy in very obese rats. Sprague Dawley rats on high-fat diet (696 ± 8 g, n  = 72) were randomized to three cohorts (C1-C3). Rats in C1 were administered vehicle, rat amylin (50 µg kg -1  d -1 ), murine leptin (125 µg kg -1  d -1 ) or amylin and leptin for 28 days ( n  = 6 per group) via subcutaneous minipump. Simultaneously, C2 and C3 rats initiated CR. After moderate (12.4 ± 0.3%, 86.7 ± 2.8 g; C2) or severe (24.9 ± 0.3%, 172.7 ± 4.7 g; C3) weight loss, amylin and/or leptin was administered as described. In C1, leptin did not alter weight, and amylin induced 40.2 ± 6.1 g weight loss (-6.0 ± 0.9%), which was not enhanced by leptin (44.4 ± 4.9 g, -6.1 ± 0.8%). In C2, vehicle-treated (75.1 ± 7.8 g weight change from start of treatment, 1.1 ± 0.8% difference from start of pre-CR phase) and leptin-treated rats (68.6 ± 9.2 g, -1.3 ± 1.0%) rebounded to pre-restriction weight that was attenuated by amylin (29.2 ± 11.4 g, -6.2 ± 0.7%). Leptin did not enhance the effect of amylin (22.8 ± 11.7 g, -8.3 ± 1.5%). In C3, vehicle-treated and leptin-treated rats regained most of their weight (161.9 ± 11.8, -2.3 ± 0.8% and 144.6 ± 9.5 g, -2.3 ± 0.9%, respectively), which was attenuated by amylin (91.1 ± 16.8 g, -11.2 ± 0.7%), but not enhanced by leptin (83.0 ± 7.6 g, -10.7 ± 0.8%). Extreme obesity associated with leptin resistance perturbs amylin/leptin weight loss synergy in rats, which cannot be restored by pre-treatment weight loss.

  3. Leptin-Aldosterone-Neprilysin Axis: Identification of Its Distinctive Role in the Pathogenesis of the Three Phenotypes of Heart Failure in People With Obesity.

    Science.gov (United States)

    Packer, Milton

    2018-04-10

    Obesity (especially visceral adiposity) can be associated with 3 different phenotypes of heart failure: heart failure with a reduced ejection fraction, heart failure with a preserved ejection fraction, and high-output heart failure. All 3 phenotypes are characterized by an excessive secretion of aldosterone and sodium retention. In addition, obesity is accompanied by increased signaling through the leptin receptor, which can promote activation of both the sympathetic nervous system and the renin-angiotensin system and can directly stimulate the secretion of aldosterone. The deleterious interaction of leptin and aldosterone is potentiated by the simultaneous action of adiposity and the renal sympathetic nerves to cause overactivity of neprilysin; the loss of the counterbalancing effects of natriuretic peptides is exacerbated by an additional effect of both obesity and heart failure to interfere with adiponectin signaling. This intricate neurohormonal interplay leads to plasma volume expansion as well as to adverse ventricular remodeling and cardiac fibrosis. Furthermore, the activity of aldosterone and neprilysin is not only enhanced by obesity, but these mechanisms can also promote adipogenesis and adipocyte dysfunction, thereby enhancing the positive feedback loop. Last, in elderly obese women, changes in quantity and biology of epicardial adipose tissue further enhances the release of leptin and other proinflammatory adipokines, thereby leading to cardiac and systemic inflammation, end-organ fibrosis, and multiple comorbidities. Regardless of the phenotypic expression, activation of the leptin-aldosterone-neprilysin axis appears to contribute importantly to the evolution and progression of heart failure in people with obesity. Efforts to interfere with the detrimental interactions of this distinctive neurohormonal ecosystem with existing or novel therapeutic agents are likely to yield unique clinical benefits. © 2018 American Heart Association, Inc.

  4. 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

  5. Integral role of PTP1B in adiponectin-mediated inhibition of oncogenic actions of leptin in breast carcinogenesis.

    Science.gov (United States)

    Taliaferro-Smith, LaTonia; Nagalingam, Arumugam; Knight, Brandi Brandon; Oberlick, Elaine; Saxena, Neeraj K; Sharma, Dipali

    2013-01-01

    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 carcinoma in obese patients

  6. Lipids and leptin level in natives of Kyrgyzstan.

    Science.gov (United States)

    Mirrakhimov, Erkin; Kerimkulova, Alina; Lunegova, Olga; Mirrakhimov, Aibek; Alibaeva, Nazira; Nabiev, Malik

    2014-04-01

    A possible link between obesity and impaired lipid metabolism is leptin, the 167-amino acid protein, secreted by adipocytes. The content of leptin in the body is closely associated with body mass index (BMI). Data obtained from studies on the association of leptin with dyslipidemia are contradictory. The level of leptin has not been studied in the ethnic Kyrgyz population previously. The purpose of this study was to investigate the relationship between leptin and lipid parameters in a group of ethnic Kyrgyz. The study included 322 ethnic Kyrgyz (145 males, 177 females) aged ≥30 years, living in Kyrgyzstan. Measurement of anthropometric parameters (height, weight, waist circumference [WC], hip circumference [HC]) and blood pressure (BP) was done. Laboratory tests included blood glucose (fasting) in plasma, lipid profile (total cholesterol [TC], triglycerides [TG], high-density lipoprotein [HDL] cholesterol, low-density lipoprotein [LDL] cholesterol), and serum leptin. Leptin was positively correlated with BMI, WC and TG in both sexes and with TC in males. Leptin is associated with BMI, WC and TG in both sexes of Kyrgyz and with TC in Kyrgyz males.

  7. Effects of β-aminoisobutyric acid on leptin production and lipid homeostasis: mechanisms and possible relevance for the prevention of obesity.

    Science.gov (United States)

    Begriche, Karima; Massart, Julie; Fromenty, Bernard

    2010-06-01

    Beta-aminoisobutyric acid (BAIBA) is a catabolite of thymine and antiretroviral thymine analogues AZT and d4T. We recently discovered that this beta-amino acid is able to enhance fatty acid oxidation and reduce body weight in mice through an increased production of leptin by the white adipose tissue (WAT). Furthermore, BAIBA could have favourable effects on nonalcoholic steatohepatitis in a leptin-independent manner. In the present review, we shall recall the circumstances that led us to discover the effects of BAIBA on body fat mass and lipid homeostasis. In addition, we put forward several hypothetical mechanisms whereby BAIBA could enhance leptin secretion by WAT and present some anti-inflammatory effects in the liver. We also discuss in this review (i) the deleterious impacts caused by the absence of, or low leptin expression on lipid homeostasis and body weight in humans and animals and (ii) recent data from other investigators suggesting that increasing leptin levels and/or responsiveness may be indeed an attractive pharmacological strategy in order to prevent (and/or treat) obesity, at least in some individuals.

  8. HER2 induces expression of leptin in human breast epithelial cells

    Directory of Open Access Journals (Sweden)

    Aree Moon

    2012-12-01

    Full Text Available A close association between the obesity hormone leptin andbreast cancer progression has been suggested. The presentstudy investigated the molecular mechanism for enhancedleptin expression in breast cancer cells and its functionalsignificance in breast cancer aggressiveness. We examinedwhether leptin expression level is affected by the oncoproteinhuman epidermal growth factor receptor2 (HER2, which isoverexpressed in ∼30% of breast tumors. Here, we report, forthe first time, that HER2 induces transcriptional activation ofleptin in MCF10A human breast epithelial cells. We alsoshowed that p38 mitogen-activated protein kinase signalingwas involved in leptin expression induced by HER2. Weshowed a crucial role of leptin in the invasiveness ofHER2-MCF10A cells using an siRNA molecule targeting leptin.Taken together, the results indicate a molecular link betweenHER2 and leptin, providing supporting evidence that leptinrepresents a target for breast cancer therapy.

  9. Leptin as a critical regulator of hepatocellular carcinoma development through modulation of human telomerase reverse transcriptase

    Directory of Open Access Journals (Sweden)

    Stefanou Nikolaos

    2010-08-01

    Full Text Available Abstract Background Numerous epidemiological studies have documented that obesity is associated with hepatocellular carcinoma (HCC. The aim of this study was to investigate the biological actions regulated by leptin, the obesity biomarker molecule, and its receptors in HCC and the correlation between leptin and human telomerase reverse transcriptase (hTERT, a known mediator of cellular immortalization. Methods We investigated the relationship between leptin, leptin receptors and hTERT mRNA expression in HCC and healthy liver tissue samples. In HepG2 cells, chromatin immunoprecipitation assay was used to study signal transducer and activator of transcription-3 (STAT3 and myc/mad/max transcription factors downstream of leptin which could be responsible for hTERT regulation. Flow cytometry was used for evaluation of cell cycle modifications and MMP1, 9 and 13 expression after treatment of HepG2 cells with leptin. Blocking of leptin's expression was achieved using siRNA against leptin and transfection with liposomes. Results We showed, for the first time, that leptin's expression is highly correlated with hTERT expression levels in HCC liver tissues. We also demonstrated in HepG2 cells that leptin-induced up-regulation of hTERT and TA was mediated through binding of STAT3 and Myc/Max/Mad network proteins on hTERT promoter. We also found that leptin could affect hepatocellular carcinoma progression and invasion through its interaction with cytokines and matrix mettaloproteinases (MMPs in the tumorigenic microenvironment. Furthermore, we showed that histone modification contributes to leptin's gene regulation in HCC. Conclusions We propose that leptin is a key regulator of the malignant properties of hepatocellular carcinoma cells through modulation of hTERT, a critical player of oncogenesis.

  10. Leptin as a critical regulator of hepatocellular carcinoma development through modulation of human telomerase reverse transcriptase

    International Nuclear Information System (INIS)

    Stefanou, Nikolaos; Papanikolaou, Vassilis; Furukawa, Yoichi; Nakamura, Yusuke; Tsezou, Aspasia

    2010-01-01

    Numerous epidemiological studies have documented that obesity is associated with hepatocellular carcinoma (HCC). The aim of this study was to investigate the biological actions regulated by leptin, the obesity biomarker molecule, and its receptors in HCC and the correlation between leptin and human telomerase reverse transcriptase (hTERT), a known mediator of cellular immortalization. We investigated the relationship between leptin, leptin receptors and hTERT mRNA expression in HCC and healthy liver tissue samples. In HepG2 cells, chromatin immunoprecipitation assay was used to study signal transducer and activator of transcription-3 (STAT3) and myc/mad/max transcription factors downstream of leptin which could be responsible for hTERT regulation. Flow cytometry was used for evaluation of cell cycle modifications and MMP1, 9 and 13 expression after treatment of HepG2 cells with leptin. Blocking of leptin's expression was achieved using siRNA against leptin and transfection with liposomes. We showed, for the first time, that leptin's expression is highly correlated with hTERT expression levels in HCC liver tissues. We also demonstrated in HepG2 cells that leptin-induced up-regulation of hTERT and TA was mediated through binding of STAT3 and Myc/Max/Mad network proteins on hTERT promoter. We also found that leptin could affect hepatocellular carcinoma progression and invasion through its interaction with cytokines and matrix mettaloproteinases (MMPs) in the tumorigenic microenvironment. Furthermore, we showed that histone modification contributes to leptin's gene regulation in HCC. We propose that leptin is a key regulator of the malignant properties of hepatocellular carcinoma cells through modulation of hTERT, a critical player of oncogenesis

  11. Variability in the leptin, leptin receptor and heart fatty acid binding protein genes in relationship with meat quality traits in pigs

    Directory of Open Access Journals (Sweden)

    Renata Mikolášová

    2005-01-01

    Full Text Available The leptin (LEP-HinfI, leptin receptor (LEPR-HpaII and heart fatty acid binding protein (H-FABP-HinfI genes and their genotypes combination (LEP-HinfI *LEPR-HpaII were tested for associations with the pH1, pH24, myoglobin content (mg/100 g, intramuscular fat content (% and remission (%. The genotypes were determined in Large White, Landrace and Duroc breeds (n = 106, 56 and 4, respectively. The allele frequencies were: LEP-HinfI: C = 0.133 T = 0.867; LEPR-HpaII: A = 0.331 B = 0.669; H-FABP-HinfI: H = 0.745 h = 0.255. The populations of breeds were in the genetic equilibrium according to the χ2 test in the tested loci. The combinations of LEP-HinfI and LEPR-HpaII were significantly associated with the pH24 and remission. The H-FABP-HinfI locus was significantly associated with intramuscular fat content.

  12. Physiology of leptin: energy homeostasis, neuroendocrine function and metabolism.

    Science.gov (United States)

    Park, Hyeong-Kyu; Ahima, Rexford S

    2015-01-01

    Leptin is secreted by adipose tissue and regulates energy homeostasis, neuroendocrine function, metabolism, immune function and other systems through its effects on the central nervous system and peripheral tissues. Leptin administration has been shown to restore metabolic and neuroendocrine abnormalities in individuals with leptin-deficient states, including hypothalamic amenorrhea and lipoatrophy. In contrast, obese individuals are resistant to leptin. Recombinant leptin is beneficial in patients with congenital leptin deficiency or generalized lipodystrophy. However, further research on molecular mediators of leptin resistance is needed for the development of targeted leptin sensitizing therapies for obesity and related metabolic diseases. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Effects of sex steroid hormones and menopause on serum leptin concentrations.

    Science.gov (United States)

    Di Carlo, C; Tommaselli, G A; Nappi, C

    2002-12-01

    Leptin is a protein secreted by adipocytes; its circulating levels are correlated to fat mass and it acts on the hypothalamic centers regulating body weight. Leptin may also play an important role in regulating reproductive function. Indeed, ob/ob mice, lacking leptin due to a genetic mutation, are obese and infertile; administration of recombinant leptin to these animals reduces body weight and restores fertility. A sexual dimorphism in serum leptin levels has also been observed, with higher concentrations in women. Studies in vitro seem to indicate that estrogens stimulate leptin secretion, while in vivo studies are extremely discordant. In humans, several studies showed increased, unmodified and decreased leptin levels after the menopause. Furthermore, hormonal replacement therapy (HRT) after the menopause was reported to result in unmodified, increased or decreased leptin levels. It is likely that the effects of postmenopausal hypoestrogenism on leptin levels are masked by the postmenopausal changes in body composition. Indeed, after menopause, there is an increase in body weight, body mass index (BMI) and fat mass with a centralization of fat distribution. Administration of HRT may stop these changes and even restore a premenopausal pattern, leading then to decreased leptin levels.

  14. Amylin/leptin synergy is absent in extreme obesity and not restored by calorie restriction‐induced weight loss in rats

    Science.gov (United States)

    Wittmer, C.; Athanacio, J.; Griffin, P. S.; Parkes, D. G.; Roth, J. D.

    2016-01-01

    Summary Objective Co‐administration of amylin and leptin induces synergistic and clinically meaningful (>10%) weight loss that is attenuated as the degree of obesity increases. We explored whether calorie restriction (CR) could restore amylin/leptin synergy in very obese rats. Methods Sprague Dawley rats on high‐fat diet (696 ± 8 g, n = 72) were randomized to three cohorts (C1–C3). Rats in C1 were administered vehicle, rat amylin (50 µg kg−1 d−1), murine leptin (125 µg kg−1 d−1) or amylin and leptin for 28 days (n = 6 per group) via subcutaneous minipump. Simultaneously, C2 and C3 rats initiated CR. After moderate (12.4 ± 0.3%, 86.7 ± 2.8 g; C2) or severe (24.9 ± 0.3%, 172.7 ± 4.7 g; C3) weight loss, amylin and/or leptin was administered as described. Results In C1, leptin did not alter weight, and amylin induced 40.2 ± 6.1 g weight loss (−6.0 ± 0.9%), which was not enhanced by leptin (44.4 ± 4.9 g, −6.1 ± 0.8%). In C2, vehicle‐treated (75.1 ± 7.8 g weight change from start of treatment, 1.1 ± 0.8% difference from start of pre‐CR phase) and leptin‐treated rats (68.6 ± 9.2 g, −1.3 ± 1.0%) rebounded to pre‐restriction weight that was attenuated by amylin (29.2 ± 11.4 g, −6.2 ± 0.7%). Leptin did not enhance the effect of amylin (22.8 ± 11.7 g, −8.3 ± 1.5%). In C3, vehicle‐treated and leptin‐treated rats regained most of their weight (161.9 ± 11.8, −2.3 ± 0.8% and 144.6 ± 9.5 g, −2.3 ± 0.9%, respectively), which was attenuated by amylin (91.1 ± 16.8 g, −11.2 ± 0.7%), but not enhanced by leptin (83.0 ± 7.6 g, −10.7 ± 0.8%). Conclusions Extreme obesity associated with leptin resistance perturbs amylin/leptin weight loss synergy in rats, which cannot be restored by pre‐treatment weight loss. PMID:28090343

  15. Circulating leptin and thyroid dysfunction

    DEFF Research Database (Denmark)

    Zimmermann-Belsing, Tina; Brabant, Georg; Holst, Jens Juul

    2003-01-01

    the fields of nutrition, metabolism and endocrinology. Leptin is accepted as an adipose signal, and even though the underlying mechanisms are not fully clarified, leptin, in addition to the thyroid hormones, is believed to be involved in regulation during the switch from the fed to the starved state...... relationship between leptin and thyroid hormones, there might also be a peripheral relationship although this effect is not clear. Both thyroid hormones and leptin might be involved in the adaptive thermogenesis through mitochondrial uncoupling proteins and heat production because both thyroxine...... hormone involvement in thermogenesis and regulation of uncoupling proteins. In this review, we have focused on leptin in relation to thyroid pathophysiology....

  16. Molecular cloning of feline resistin and the expression of resistin, leptin and adiponectin in the adipose tissue of normal and obese cats.

    Science.gov (United States)

    Takashima, Satoshi; Nishii, Naohito; Kato, Akiko; Matsubara, Tatsuya; Shibata, Sanae; Kitagawa, Hitoshi

    2016-01-01

    Resistin, one of the adipokines that has a cycteine-rich C-terminus, is considered to relate to the development of insulin resistance in rats. However, in cats, there is little knowledge regarding resistin. In this study, we cloned the feline resistin cDNA from adipose tissue by RT-PCR. The feline resistin clone contained an entire open reading frame encoding 107 amino acids that had 72.8%, 75.4%, 50.9% and 51.8% homology with bovine, human, mouse and rat homologues, respectively. In both subcutaneous and visceral adipose tissues, the transcription levels of feline resistin mRNA were significantly higher in obese cats than normal cats, and those of feline adiponectin mRNA were significantly lower in obese cats than normal cats. However, there was no difference in the expression of feline leptin between normal and obese cats. On the other hand, in both normal and obese cats, there were no significant differences in resistin, leptin and adiponectin mRNA levels between subcutaneous and visceral adipose tissues. In cats, the altered expression of resistin and adiponectin mRNA with obesity may contribute to the pathogenesis of insulin resistance and subsequent diabetes mellitus. In addition to feline adiponectin, the feline resistin cDNA clone obtained in this study will be useful for further investigation of the pathogenesis of obesity in cats.

  17. Leptin upregulates telomerase activity and transcription of human telomerase reverse transcriptase in MCF-7 breast cancer cells

    International Nuclear Information System (INIS)

    Ren, He; Zhao, Tiansuo; Wang, Xiuchao; Gao, Chuntao; Wang, Jian; Yu, Ming; Hao, Jihui

    2010-01-01

    The aim was to analyze the mechanism of leptin-induced activity of telomerase in MCF-7 breast cancer cells. We found that leptin activated telomerase in a dose-dependent manner; leptin upregulated the expression of Human Telomerase Reverse Transcriptase (hTERT) at mRNA and protein levels; blockade of signal transducer and activator of transcription 3 (STAT3) phosphorylation significantly counteracted leptin-induced hTERT transcription and protein expression; chromatin immunoprecipitation analysis showed that leptin enhanced the binding of STAT3 to the hTERT promoter. This study uncovers a new mechanism of the proliferative effect of leptin on breast cancer cells and provides a new explanation of obesity-related breast cancer.

  18. Leptin upregulates telomerase activity and transcription of human telomerase reverse transcriptase in MCF-7 breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Ren, He, E-mail: herenrh@yahoo.com.cn [Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin Medical University Cancer Hospital, Tianjin (China); Zhao, Tiansuo; Wang, Xiuchao; Gao, Chuntao; Wang, Jian; Yu, Ming [Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin Medical University Cancer Hospital, Tianjin (China); Hao, Jihui, E-mail: jihuihao@yahoo.com [Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin Medical University Cancer Hospital, Tianjin (China)

    2010-03-26

    The aim was to analyze the mechanism of leptin-induced activity of telomerase in MCF-7 breast cancer cells. We found that leptin activated telomerase in a dose-dependent manner; leptin upregulated the expression of Human Telomerase Reverse Transcriptase (hTERT) at mRNA and protein levels; blockade of signal transducer and activator of transcription 3 (STAT3) phosphorylation significantly counteracted leptin-induced hTERT transcription and protein expression; chromatin immunoprecipitation analysis showed that leptin enhanced the binding of STAT3 to the hTERT promoter. This study uncovers a new mechanism of the proliferative effect of leptin on breast cancer cells and provides a new explanation of obesity-related breast cancer.

  19. Regulation of plasma agouti-related protein and its relationship with hunger in lean and obese men.

    Science.gov (United States)

    Hazell, Tom J; Sawula, Laura; Edgett, Brittany A; Walsh, Jeremy J; Gurd, Brendon J

    2016-12-01

    Agouti-related protein (AgRP) is an orexigenic (appetite stimulating) neuropeptide suggested to exert tonic control over long-term energy balance. While some have speculated AgRP is not involved in the episodic (i.e. meal to meal energy intake) control, acute decreases in plasma agouti-related protein (AgRP) following a meal have been observed in humans in a role consistent with episodic control for AgRP. Whether changes in plasma AgRP are associated with episodic, and/or tonic changes in appetite has yet to be directly examined. The present study examined the relationship between agouti-related protein (AgRP), leptin and the regulation of appetite following a 48-h fast and an acute meal challenge. Blood samples were obtained from young lean and obese men before and after a 48 h fast (lean n = 10; obese n = 7). Fasting resulted in an increase in AgRP and a decrease in leptin with these changes being greater in lean than obese. In addition, blood samples were obtained from lean men before and 1, 2, 3 and 4 h after a meal (n = 8). Following a meal, AgRP was reduced from 2 to 4 h, a change that was dissociated from both leptin and subjective measures of hunger and satiety. These results demonstrate that AgRP is not associated with changes in hunger or satiety, and can change without corresponding changes in leptin. This suggests that AgRP may not be involved in the episodic control of appetite and the release of AgRP may involve signals other than leptin. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Obesity and Postmenopausal Breast Cancer: Leptin-Estrogen Cross-Talk

    National Research Council Canada - National Science Library

    Surmacz, Eva

    2004-01-01

    Obesity is a risk factor for breast cancer development in postmenopausal women and correlates with shorter disease-free and overall survival in breast cancer patients, regardless of menopausal status...

  1. Obesity in BSB mice is correlated with expression of genes foriron homeostasis and leptin

    Energy Technology Data Exchange (ETDEWEB)

    Farahani, Poupak; Chiu, Sally; Bowlus, Christopher L.; Boffelli,Dario; Lee, Eric; Fisler, Janis S.; Krauss, Ronald M.; Warden, Craig H.

    2003-04-01

    Obesity is a complex disease. To date, over 100 chromosomal loci for body weight, body fat, regional white adipose tissue weight, and other obesity-related traits have been identified in humans and in animal models. For most loci, the underlying genes are not yet identified; some of these chromosomal loci will be alleles of known obesity genes, whereas many will represent alleles of unknown genes. Microarray analysis allows simultaneous multiple gene and pathway discovery. cDNA and oligonucleotide arrays are commonly used to identify differentially expressed genes by surveys of large numbers of known and unnamed genes. Two papers previously identified genes differentially expressed in adipose tissue of mouse models of obesity and diabetes by analysis of hybridization to Affymetrix oligonucleotide chips.

  2. 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.

  3. The association between depression and leptin is mediated by adiposity.

    Science.gov (United States)

    Morris, Alanna A; Ahmed, Yusuf; Stoyanova, Neli; Hooper, William Craig; De Staerke, Christine; Gibbons, Gary; Quyyumi, Arshed; Vaccarino, Viola

    2012-06-01

    Animal models suggest that impaired leptin production, or leptin resistance despite increased leptin levels, may contribute to depression. The link between leptin and depression could be mediated by obesity, which is more common in depression and increases leptin production. We administered the Beck Depression Inventory-II (BDI-II) to 537 participants (mean [standard deviation (SD)] age = 51 [9] years; female, 61%) enrolled in the Morehouse and Emory Team up to Eliminate Health Disparities (META-Health) study. Leptin levels were examined as continuous log-transformed values. Participants with moderate to severe depression had higher levels of leptin (median [interquartile range] 37.7 [17.6-64.9] ng/mL) than those with mild depression (22.9 [7.0-57.9] ng/mL) or minimal to no depression (19.8 ng/mL [7.8-39.1], p = .003). Participants with moderate to severe depression had higher body mass index (BMI) than those with mild or minimal depression (mean [SD] = 33 [8] versus 31 [9] versus 29 [7] kg/m(2), p = .001). After multivariate adjustment for age, sex, race, smoking status, hypertension, diabetes, blood pressure, lipids, and C-reactive protein, the BDI-II score remained a significant predictor of leptin levels (β = 0.093, p = .01). Further adjustment for BMI eliminated the association between the BDI-II score and leptin (β = 0.03, p = .3). Adjusting for waist circumference in place of BMI revealed similar findings. The association between depression and leptin seems to be mediated by increased adiposity in depressed individuals.

  4. Leptin Enhances Synthesis of Proinflammatory Mediators in Human Osteoarthritic Cartilage—Mediator Role of NO in Leptin-Induced PGE2, IL-6, and IL-8 Production

    Directory of Open Access Journals (Sweden)

    Katriina Vuolteenaho

    2009-01-01

    Full Text Available Obesity is an important risk factor for osteoarthritis (OA in weight-bearing joints, but also in hand joints, pointing to an obesity-related metabolic factor that influences on the pathogenesis of OA. Leptin is an adipokine regulating energy balance, and it has recently been related also to arthritis and inflammation as a proinflammatory factor. In the present paper, the effects of leptin on human OA cartilage were studied. Leptin alone or in combination with IL-1 enhanced the expression of iNOS and COX-2, and production of NO, PGE2, IL-6, and IL-8. The results suggest that the effects of leptin are mediated through activation of transcription factor nuclear factor κB (NF-κB and mitogen-activated protein kinase (MAPK pathway c-Jun NH2-terminal kinase (JNK. Interestingly, inhibition of leptin-induced NO production with a selective iNOS inhibitor 1400 W inhibited also the production of IL-6, IL-8, and PGE2, and this was reversed by exogenously added NO-donor SNAP, suggesting that the effects of leptin on IL-6, IL-8, and PGE2 production are dependent on NO. These findings support the idea of leptin as a factor enhancing the production of proinflammatory factors in OA cartilage and as an agent contributing to the obesity-associated increased risk for osteoarthritis.

  5. 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.

  6. Leptin deficient ob/ob mice and diet-induced obese mice responded differently to Roux-en-Y bypass surgery.

    Science.gov (United States)

    Hao, Z; Münzberg, H; Rezai-Zadeh, K; Keenan, M; Coulon, D; Lu, H; Berthoud, H-R; Ye, J

    2015-05-01

    Weight regain contributes to the therapeutic failure in 15-20% of type 2 diabetic patients after Roux-en-Y gastric bypass surgery (RYGB), and the mechanism remains largely unknown. This study was conducted to explore the mechanism of weight regain. Wild-type (WT) diet-induced obese (DIO) mice were used to mimic human obesity, and ob/ob mice were used for leptin deficiency-induced obesity. Two groups of mice were compared in weight regain for 10 months after RYGB. Weight loss, food intake, fecal energy loss and energy expenditure were monitored in the study of weight regain. Fasting insulin, insulin tolerance and homeostatic model assessment-insulin resistance were tested for insulin sensitivity under the weight regain. Weight loss from RYGB and calorie restriction was compared for the impact in insulin sensitivity. In WT mice, RYGB induced a sustained weight loss and insulin sensitization over the sham operation in this 10-month study. However, RYGB failed to generate the same effects in leptin-deficient ob/ob mice, which suffered a weight regain over the pre-surgery level. In ob/ob mice, body weight was reduced by RYGB transiently in the first week, recovered in the second week and increased over the baseline thereafter. Weight loss was induced by RYGB relative to that of sham mice, but the loss was not sufficient to keep body weight below the pre-surgery levels. In addition, insulin sensitivity was not improved by the weight loss. The response to RYGB was improved in ob/ob mice by 2 weeks of leptin treatment. Weight loss from calorie restriction had an equivalent effect on insulin sensitization compared with that of RYGB. Those data demonstrate that ob/ob mice and DIO mice responded differently to RYGB surgery, suggesting that leptin may be one of the factors required for RYGB to prevent weight regain and diabetes recurrence.

  7. Monitoring leptin activity using the chicken leptin receptor.

    Science.gov (United States)

    Hen, Gideon; Yosefi, Sera; Ronin, Ana; Einat, Paz; Rosenblum, Charles I; Denver, Robert J; Friedman-Einat, Miriam

    2008-05-01

    We report on the construction of a leptin bioassay based on the activation of chicken leptin receptor in cultured cells. A human embryonic kidney (HEK)-293 cell line, stably transfected with the full-length cDNA of chicken leptin receptor together with a STAT3-responsive reporter gene specifically responded to recombinant human and Xenopus leptins. The observed higher sensitivity of chicken leptin receptor to the former is in agreement with the degree of sequence similarity among these species (about 60 and 38% identical amino acids between humans and chickens, and between humans and Xenopus respectively). The specific activation of signal transduction through the chicken leptin receptor, shown here for the first time, suggests that the transition of Gln269 (implicated in the Gln-to-Pro Zucker fatty mutation in rats) to Glu in chickens does not impair its activity. Analysis of leptin-like activity in human serum samples of obese and lean subjects coincided well with leptin levels determined by RIA. Serum samples of pre- and post partum cows showed a tight correlation with the degree of adiposity. However, specific activation of the chicken leptin receptor in this assay was not observed with serum samples from broiler or layer chickens (representing fat and lean phenotypes respectively) or with those from turkey. Similar leptin receptor activation profiles were observed with cells transfected with human leptin receptor. Further work is needed to determine whether the lack of leptin-like activity in the chicken serum samples is due to a lack of leptin in this species or simply to a serum level of leptin that is below the detection threshold.

  8. Comparative measurement of ghrelin, leptin, adiponectin, EGF and IGF-1 in breast milk of mothers with overweight/obese and normal-weight infants.

    Science.gov (United States)

    Khodabakhshi, A; Ghayour-Mobarhan, M; Rooki, H; Vakili, R; Hashemy, S-I; Mirhafez, S R; Shakeri, M-T; Kashanifar, R; Pourbafarani, R; Mirzaei, H; Dahri, M; Mazidi, M; Ferns, G; Safarian, M

    2015-05-01

    Obese infants are more susceptible to develop adulthood obesity and its related comorbidities. Previous studies have shown the presence of hormones and growth factors in maternal breast milk that may influence infant adiposity. The aim of this study was to investigate differences in concentrations of three hormones and two growth factors in the breast milk of mothers with obese and non-obese infants. In this cross-sectional study, 40 mothers with overweight or obese infants (weight for length percentile >97) and 40 age-matched mothers with normal-weight infant (-10 milk concentrations of ghrelin and adiponectin, leptin, epithelial growth factor (EGF) and insulin-like growth factor-1 (IGF-1) were measured using enzyme-linked immunosorbent assay methods. The mean breast milk concentration of ghrelin was higher in mothers with normal-weight infants, 137.50 pg/ml, than in mothers with obese infants, 132.00 pg/ml (P=0.001). This was also true regarding the concentration of EGF in mothers with (0/04 ng/ml) and without (0/038 ng/ml) normal-weight infants (P=0.01). No significant differences were observed in concentrations of leptin, adiponectin and IGF-1 between two groups (P > 0.05). There was also a significant positive correlation between EGF and ghrelin in both groups. This study revealed that there was a correlation between ghrelin and EGF level in breast milk of mothers with obese and non-obese infants, suggesting a possible regulatory effect of these two hormones on weight in infants.

  9. Consequences of protein supplementation for anorexia, expression of immunity and plasma leptin concentrations in parasitized ewes of two breeds.

    Science.gov (United States)

    Zaralis, Konstantinos; Tolkamp, Bert J; Houdijk, Jos G M; Wylie, Alastair R G; Kyriazakis, Ilias

    2009-02-01

    The periparturient relaxation of immunity (PPRI) against parasites in ewes has a nutritional basis. We investigated whether ewes experience a reduction in food intake (anorexia) during PPRI and if the magnitude of anorexia is affected by host production potential and dietary protein supplementation. We also investigated whether nematode infection is linked to plasma leptin concentrations in periparturient ewes. The experiment was a 2 x 2 x 2 factorial design. Two breeds of twin-bearing/lactating ewes (Greyface cross, G (n 32) and Scottish Blackface, B (n 32)) were used. Half of the ewes were trickle infected with 30,000 larvae of the abomasal parasite Teladorsagia circumcincta per week and the other half were not. During the experiment, all ewes had ad libitum access to a low-protein diet that provided less protein than the recommended allowance. In addition, half of the ewes received a protein supplement that resulted in protein intakes that exceeded recommendations. Nematode infection resulted in a breakdown of immunity to parasites and a reduction in food intake in both breeds. The breeds differed in the extent of PPRI (G ewes having higher faecal egg counts than B ewes), but not in the magnitude of anorexia. Protein supplementation resulted in a reduction in faecal egg counts, but had no effect on the magnitude of anorexia. Plasma leptin concentrations changed significantly over time, but were not affected by protein supplementation or infection. It is concluded that infection with T. circumcincta in periparturient ewes results in anorexia that is not alleviated by protein supplementation and seems unrelated to plasma leptin concentrations.

  10. Novel Insights into How Overnutrition Disrupts the Hypothalamic Actions of Leptin

    Directory of Open Access Journals (Sweden)

    Stefanie Fruhwürth

    2018-03-01

    Full Text Available Obesity has become a worldwide health problem, but we still do not understand the molecular mechanisms that contribute to overeating and low expenditure of energy. Leptin has emerged as a major regulator of energy balance through its actions in the hypothalamus. Importantly, obese people exhibit high circulating levels of leptin, yet the hypothalamus no longer responds normally to this hormone to suppress appetite or to increase energy expenditure. Several well-known hypotheses have been proposed to explain impaired central responsiveness to the effects of leptin in obesity, including defective transit across the blood–brain barrier at the arcuate nucleus, hypothalamic endoplasmic reticulum stress, maladaptive sterile inflammation in the hypothalamus, and overexpression of molecules that may inhibit leptin signaling. We also discuss a new explanation that is based on our group’s recent discovery of a signaling pathway that we named “NSAPP” after its five main protein components. The NSAPP pathway consists of an oxide transport chain that causes a transient, targeted burst in intracellular hydrogen peroxide (H2O2 to inactivate redox-sensitive members of the protein tyrosine phosphatase gene family. The NSAPP oxide transport chain is required for full activation of canonical leptin signaling in neurons but fails to function normally in states of overnutrition. Remarkably, leptin and insulin both require the NSAPP oxide transport chain, suggesting that a defect in this pathway could explain simultaneous resistance to the appetite-suppressing effects of both hormones in obesity.

  11. The effects of bisphenol A (BPA) exposure on fat mass and serum leptin concentrations have no impact on bone mineral densities in non-obese premenopausal women.

    Science.gov (United States)

    Zhao, Hong-yan; Bi, Yu-fang; Ma, Lin-ying; Zhao, Lin; Wang, Tian-ge; Zhang, Lian-zhen; Tao, Bei; Sun, Li-hao; Zhao, Yong-ju; Wang, Wei-qing; Li, Xiao-yin; Xu, Man-yin; Chen, Jia-lun; Ning, Guang; Liu, Jian-min

    2012-12-01

    Bisphenol A (BPA) exposure may promote obesity, but its effect on bone mineral density (BMD) has not been reported in humans. We aimed to examine the relationships between BPA exposure, body composition, serum estradiol, leptin, osteocalcin levels and BMDs in healthy premenopausal women. In this cross-sectional study, a total of 246 healthy premenopausal women aged 20 years and older with regular menstrual cycles were investigated. Body mass index (BMI), fat mass, fat-free mass and BMDs were measured by DXA. Serum estradiol, leptin, osteocalcin, urinary BPA and NTx levels were also tested. Urinary BPA levels were positively associated with fat mass (r=0.193, p=0.006) and leptin (r=0.236, p=0.001) but not with fat-free mass after adjusting for age and BMI. BPA was not associated with serum estradiol levels, BMDs, or bone resorption marker NTx and bone formation parameter osteocalcin, either. A multivariate stepwise regression analysis confirmed that serum leptin levels were positively influenced by fat mass (β=0.746, pBPA (β=0.127, p=0.01) but negatively correlated with fat-free mass (β=-0.196, pBPA exposure. Although BPA exposure is related with increased amount of fat mass and elevated serum leptin levels, it has neutral effect on BMDs in premenopausal women, possibly due to the exclusive role of fat-free mass, which is unrelated to BPA in determining BMDs. Copyright © 2012 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  12. Relationship between serum leptin level and cardiovascular, nutrtional risk factors in non-diabetic hemodialysis.

    Directory of Open Access Journals (Sweden)

    Hyung-Jong Kim

    2012-06-01

    Full Text Available Many studies showed that obesity was associated with high level of serum leptin, hyperhomocysteinemia, and insulin resistance in general population. Obesity is associated with various cardiovascular and metabolic complications. However, in end stage renal failure, it has been reported that obesity is associated with a favorable survival of patients. The purpose of this observational study was to investigate the relationship between serum leptin level increased at obesity and cardiovascular, nutritional traditional markers, and the comparison of patient’s survival for 5 years according to obesity in non-diabetic hemodialysis. A cross-sectional study was performed in obese and non-obese subjects according to body mass index. Fifteen obese patients (BMI≥25 kg/m2 and 29 non-obese patients (BMI<25 kg/m2 were studied. For each subject, blood was sampled for measurement of serum leptin, insulin resistance, C-reactive protein (CRP and nutritional parameters before hemodialysis. Insulin resistance was calculated by HOMA-IR. Linear regression analysis was performed to determine the relationship among insulin resistance, serum leptin level and nutritional parameters. In results, serum leptin level was significant positive correlated with BMI, nPCR, pre-albumin and HOMA-IR (p<0.05. Serum leptin level was significant negative correlated with tCO2 and CRP (p<0.05. Five years survival by Kaplan-Meier analysis was more favorable in obese group but did not show statistical significance (p=0.053. In conclusion, serum leptin level was associated with obesity and good nutrition status. But in view of positive correlation of HOMA-IR, serum leptin level may be associated with cardiovascular complication in non-diabetic hemodialysis patients. Therefore, we thought that serum leptin level may be a good nutritional marker and a cardiovascular risk factor. We thought that the further study for the proper leptin level will be needed and help the improvement of

  13. Diet-induced obesity has neuroprotective effects in murine gastric enteric nervous system: involvement of leptin and glial cell line-derived neurotrophic factor.

    Science.gov (United States)

    Baudry, Charlotte; Reichardt, François; Marchix, Justine; Bado, André; Schemann, Michael; des Varannes, Stanislas Bruley; Neunlist, Michel; Moriez, Raphaël

    2012-02-01

    Nutritional factors can induce profound neuroplastic changes in the enteric nervous system (ENS), responsible for changes in gastrointestinal (GI) motility. However, long-term effects of a nutritional imbalance leading to obesity, such as Western diet (WD), upon ENS phenotype and control of GI motility remain unknown. Therefore, we investigated the effects of WD-induced obesity (DIO) on ENS phenotype and function as well as factors involved in functional plasticity. Mice were fed with normal diet (ND) or WD for 12 weeks. GI motility was assessed in vivo and ex vivo. Myenteric neurons and glia were analysed with immunohistochemical methods using antibodies against Hu, neuronal nitric oxide synthase (nNOS), Sox-10 and with calcium imaging techniques. Leptin and glial cell line-derived neurotrophic factor (GDNF) were studied using immunohistochemical, biochemical or PCR methods in mice and primary culture of ENS. DIO prevented the age-associated decrease in antral nitrergic neurons observed in ND mice. Nerve stimulation evoked a stronger neuronal Ca(2+) response in WD compared to ND mice. DIO induced an NO-dependent increase in gastric emptying and neuromuscular transmission in the antrum without any change in small intestinal transit. During WD but not ND, a time-dependent increase in leptin and GDNF occurred in the antrum. Finally, we showed that leptin increased GDNF production in the ENS and induced neuroprotective effects mediated in part by GDNF. These results demonstrate that DIO induces neuroplastic changes in the antrum leading to an NO-dependent acceleration of gastric emptying. In addition, DIO induced neuroplasticity in the ENS is likely to involve leptin and GDNF.

  14. Effects of dietary energy and protein density on plasma concentrations of leptin and metabolic hormones in dairy heifers.

    Science.gov (United States)

    Chelikani, P K; Ambrose, D J; Keisler, D H; Kennelly, J J

    2009-04-01

    The hormonal and metabolic signals that communicate the level of body energy reserves to the reproductive-mammary axis remain undefined in dairy cattle; consequently, our hypothesis was that leptin may fulfill this role. Our objectives were to determine the effects of diets differing in energy and protein density on dry matter intake (DMI), growth traits [body weight (BW), body condition score (BCS), back-fat (BF) thickness], and temporal changes in plasma concentrations of leptin, insulin, growth hormone (GH), insulin-like growth factor-1 (IGF-1), glucose, and nonesterified fatty acids (NEFA) in dairy heifers during the pre- and postpubertal periods. In period 1, heifers were randomly allotted (n = 10/diet) at 103 kg of BW to diets for a predicted average daily gain of 1.10 (high, H), 0.80 (medium, M), or 0.50 kg/d (low, L). Five heifers in each of the H and L groups were further studied during period 2, either at 12 mo of age (HA, LA) or at 330 kg of BW (HW, LW). The data provide evidence that 1) DMI (18%), BW (17%), and BF (5%) together explained 40% of the variation in plasma leptin concentrations (r(2) = 0.396); 2) unlike the acute postprandial increase in plasma insulin as a result of increased nutrient density (H 1.42 +/- 0.09, M 1.02 +/- 0.09, L 0.68 +/- 0.11 ng/mL), plasma leptin concentrations did not respond acutely with a distinct postprandial profile; 3) although plasma leptin concentrations increased with age, leptin at puberty did not differ among treatment groups (H 5.63 +/- 2.48, M 4.28 +/- 0.55, L 4.12 +/- 0.72 ng/mL) and there was no evidence of an abrupt transition in prepubertal plasma leptin concentrations; 4) plasma leptin concentrations may not be a critical trigger for puberty in rapidly growing heifers, but are apparently essential for puberty in heifers with normal or restricted growth rates; and 5) plasma concentrations of insulin (H 0.59 +/- 0.07, M 0.43 +/- 0.09, L 0.30 +/- 0.09 ng/mL), IGF-1 (H 151.08 +/- 16.47, L 82.51 +/- 17.47 ng

  15. Leptin: a cardiovascular perspective

    African Journals Online (AJOL)

    Review Article: Leptin: a cardiovascular perspective. 72. 2012 Volume 17 No 2. JEMDSA. Introduction. Within the realms of noncommunicable disease development in South Africa, obesity is a disease that causes concern. This especially holds true for type 2 diabetes and cardiovascular diseases. Disheartened.

  16. Hypothyroidism Induces Hypophagia Associated with Alterations in Protein Expression of Neuropeptide Y and Proopiomelanocortin in the Arcuate Nucleus, Independently of Hypothalamic Nuclei-Specific Changes in Leptin Signaling.

    Science.gov (United States)

    Calvino, Camila; Império, Güínever Eustáquio; Wilieman, Marianna; Costa-E-Sousa, Ricardo Henrique; Souza, Luana Lopes; Trevenzoli, Isis Hara; Pazos-Moura, Carmen Cabanelas

    2016-01-01

    Thyroid hormone and leptin are essential regulators of energy homeostasis. Both hormones stimulate energy expenditure but have opposite effects on appetite. The mechanisms behind food intake regulation in thyroid dysfunctions are poorly understood. It has been shown that hypothyroid rats exhibited impaired leptin anorexigenic effect and signaling in total hypothalamus, even though they were hypophagic. It was hypothesized that hypothyroidism modulates the expression of neuropeptides: orexigenic neuropeptide Y (NPY) and anorexigenic proopiomelanocortin (POMC), independently of inducing nuclei-specific changes in hypothalamic leptin signaling. Adult male rats were rendered hypothyroid by administration of 0.03% methimazole in the drinking water for 21 days. Protein content of NPY, POMC, and leptin signaling (the signal transducer and activator of transcription 3 [STAT3] pathway) were evaluated by Western blot, and mRNA levels by real time reverse transcription polymerase chain reaction in arcuate (ARC), ventromedial (VMN), and paraventricular (PVN) hypothalamic nuclei isolated from euthyroid (eu) and hypothyroid (hypo) rats. Leptin anorexigenic effect was tested by recording food intake for two hours after intracerebroventricular (i.c.v.) administration of leptin. Statistical differences were considered significant at p ≤ 0.05. Hypothyroidism was confirmed by decreased serum triiodothyronine, thyroxine, and increased thyrotropin, in addition to increased levels of pro-TRH mRNA in PVN and Dio2 mRNA in the ARC of hypo rats. Hypothyroidism decreased body weight and food intake associated with decreased protein content of NPY and increased content of POMC in the ARC. Conversely, hypothyroidism induced central resistance to the acute anorexigenic effect of leptin, since while euthyroid rats displayed reduced food intake after leptin i.c.v. injection, hypothyroid rats showed no response. Hypothyroid rats exhibited decreased leptin receptor (ObRb) protein content in

  17. Leptin Enhances NR2B-mediated NMDA Responses Via a MAPK-dependent Process in Cerebellar Granule Cells.

    Science.gov (United States)

    Irving, A. J.; Wallace, L; Durakoglugil, D; Harvey, J.

    2006-01-01

    It is well documented that the hormone leptin regulates energy balance via its actions in the hypothalamus. However, evidence is accumulating that leptin plays a key role in numerous CNS functions. Indeed, leptin receptors are expressed in many extrahypothalamic brain regions, with high levels found in the hippocampus and cerebellum. In the hippocampus, leptin has been shown to facilitate NMDA receptor function and modulate synaptic plasticity. A role for leptin in cerebellar function is also indicated as leptin-deficient rodents display reduced mobility that is unrelated to obesity. Here we show that leptin receptor immunolabeling can be detected in cultured cerebellar granule cells, being expressed at the somatic plasma membrane and also concentrated at synapses. Furthermore, leptin facilitated NR2B NMDA receptor-mediated Ca2+ influx in cerebellar granule cells via a mitogen-activated protein kinase-dependent pathway. These findings provide the first direct evidence for a cellular action of leptin in cerebellar neurons. In addition, given that NMDA receptor activity in the cerebellum is crucial for normal locomotor function, these data also have important implications for the potential role of leptin in the control of movement. PMID:16413128

  18. Leptin: A cardiovascular perspective | Schutte | Journal of ...

    African Journals Online (AJOL)

    The development of obesity, as well as resultant type 2 diabetes, hypertension and cardiovascular disease, is causing concern in South Africa. Following the discovery of leptin in 1994, hopes were raised that the manipulation of the leptin axis might yield successful therapy for obesity. Although hope still remains, the role of ...

  19. Maternal obesity programs increased leptin gene expression in rat male offspring via epigenetic modifications in a depot-specific manner

    Directory of Open Access Journals (Sweden)

    Simon Lecoutre

    2017-08-01

    Conclusions: Consistent with the DOHaD hypothesis, persistent epigenetic remodeling occurs at regulatory regions especially within intergenic sequences, linked to higher leptin gene expression in adult HF offspring in a depot-specific manner.

  20. Genistein Precipitated Hypothyroidism, Altered Leptin and C ...

    African Journals Online (AJOL)

    Genistein Precipitated Hypothyroidism, Altered Leptin and C-Reactive Protein Synthesis in Pregnant Rats. ... Thyroid hormone, C-reactive protein (CRP) and leptin assay was carried using the blood samples. Leptin was also assayed in the placenta and amniotic fluid supernatant. Oral exposure of pregnant rats to genistein ...

  1. Relevance of Serum Leptin and Leptin-Receptor Concentrations in Critically Ill Patients

    Directory of Open Access Journals (Sweden)

    Alexander Koch

    2010-01-01

    Full Text Available The adipocyte-derived cytokine leptin was implicated to link inflammation and metabolic alterations. We investigated the potential role of leptin components in critically ill patients, because systemic inflammation, insulin resistance, and hyperglycemia are common features of critical illness. Upon admission to Medical Intensive Care Unit (ICU, free leptin and soluble leptin-receptor serum concentrations were determined in 137 critically ill patients (95 with sepsis, 42 without sepsis and 26 healthy controls. Serum leptin or leptin-receptor did not differ between patients or controls and were independent of sepsis. However, serum leptin was closely associated with obesity and diabetes and clearly correlated with markers of metabolism and liver function. Leptin-receptor was an unfavourable prognostic indicator, associated with mortality during three years follow-up. Our study indicates a functional role of leptin in the pathogenesis of severe illness and emphasizes the impact of complex metabolic alterations on the clinical outcome of critically ill patients.

  2. Predictors of Subclinical Inflammatory Obesity: Plasma Levels of Leptin, Very Low-Density Lipoprotein Cholesterol and CD14 Expression of CD16+ Monocytes

    Directory of Open Access Journals (Sweden)

    Fernanda Leite

    2017-07-01

    Full Text Available Objective: Predictors of subclinical inflammatory obesity (SIO can be important tools for early therapeutic interventions in obesity-related comorbidities. Waist circumference (WC and BMI have different SIO sensitivity. We aimed to i identify SIO predictors and ii investigate whether CD16+ monocytes are associated with BMI- (generally or WC-defined (centrally obesity. Methods: Anthropometric and metabolic/endocrine (namely catecholamines, adrenaline and noradrenaline parameters were evaluated, and CD16+ monocytes were studied by flow cytometry in the peripheral blood from 63 blood donors, and compared and correlated to each other. Multiple linear regression analysis was performed to identify variables that best predict SIO. Results: CD16+ monocyte counts were similar in BMI and WC groups. CD16+ monocytes from centrally obese (CO showed a more inflammatory pattern, as compared to non-CO subjects. WC was sensitive to lipidemia and, in CO subjects, lipidemia was associated with a more inflammatory phenotype of CD16+ monocytes. These differences were not noticed between BMI groups. Adrenaline was correlated with CD16+ monocyte expansion with a lower inflammatory pattern. Leptin, very low-density lipoprotein cholesterol (VLDL-C, and CD14 expression of CD16+ monocytes were found to be CO predictors. Conclusions: WC-, but not BMI-defined obesity, was associated with a more inflammatory pattern of CD16+ monocytes, without monocyte expansion, suggesting that a monocyte maturation process rather than an independent arise of CD16+ monocytes occurs in CO. Thus, in a population with low cardiovascular risk, leptin, VLDL-C, and CD14 expression of CD16+ monocytes predict CO, constituting a putative tool for screening of SIO.

  3. Association of cocaine- and amphetamine-related transcript, leptin and leptin receptor gene polymorphisms with anthropometric obesity phenotype indicators in South African learners.

    Science.gov (United States)

    Yako, Y Y; Fanampe, B L; Hassan, M S; Erasmus, R T; van der Merwe, L; van Rensburg, S J; Matsha, T E

    2011-01-01

    Obesity has increased rapidly in South African children and adolescents. Genes involved in appetite regulation have been extensively studied worldwide, but their role in the obesity phenotype in South African Black and mixed-ancestry school adolescents is unknown. Seven common polymorphisms in LEP, GHRL, CART and LEPR were analysed for genotype and haplotype association with anthropometric obesity phenotype indicators in South African Black and mixed-ancestry adolescent school learners. The CART c.517A→G polymorphism was significantly associated with obesity susceptibility. The LEPR Lys(109)Arg G allele was associated with an average reduction of 2.36 kg/m(2) in body mass index (BMI), 5.66 cm in waist circumference (WC) and 1.61 cm in mid-upper-arm circumference (MUAC). This was confirmed by haplotype analysis. Additionally, a haplotype of the LEP polymorphisms significantly increased BMI, MUAC and hip circumference, while LEPR haplotypes were associated with differences in MUAC. Our findings suggest that c.517A→G and Lys(109)Arg contribute to the variation in anthropometric obesity phenotype indicators observed among Black African and mixed-ancestry South African learners. Furthermore, haplotypes of LEP, LEPR and GHRL polymorphisms were associated with varying measurements of weight, BMI and WC. Further studies are required to confirm our results in a larger and homogeneous study population group. Copyright © 2011 S. Karger AG, Basel.

  4. Correlation of the leptin

    DEFF Research Database (Denmark)

    Finucane, F; Luan, J; Wareham, N

    2009-01-01

    AIMS/HYPOTHESIS: Obesity is the dominant cause of insulin resistance. In adult humans it is characterised by a combination of adipocyte hypertrophy and, to a lesser extent, adipocyte hyperplasia. As hypertrophic adipocytes secrete more leptin and less adiponectin, the plasma leptin......:adiponectin ratio (LAR) has been proposed as a potentially useful measure of insulin resistance and vascular risk. We sought to assess the usefulness of the LAR as a measure of insulin resistance in non-diabetic white adults. METHODS: Leptin and adiponectin levels were measured in 2,097 non-diabetic individuals...... from the Ely and European Group for the Study of Insulin Resistance (EGIR) Relationship between Insulin Sensitivity and Cardiovascular Risk (RISC) study cohorts. LAR was compared with fasting insulin and HOMA-derived insulin sensitivity (HOMA-S) in all individuals and with the insulin sensitivity index...

  5. The association between leptin and depressive symptoms is modulated by abdominal adiposity

    NARCIS (Netherlands)

    Milaneschi, Y.; Sutin, A.R.; Terracciano, A.; Canepa, M.; Gravenstein, K.S.; Egan, J.M.; Vogelzangs, N.; Guralnik, J.M.; Bandinelli, S.; Penninx, B.W.J.H.; Ferrucci, L.

    2014-01-01

    Background: Evidence for a role of leptin in depression is limited and conflicting. Inconclusive findings may be explained by the complex effect of obesity on leptin signaling. In particular, both hyperleptinemia due to leptin resistance in obese persons as well as low leptin in lean persons can

  6. A ketogenic diet impairs energy and glucose homeostasis by the attenuation of hypothalamic leptin signaling and hepatic insulin signaling in a rat model of non-obese type 2 diabetes.

    Science.gov (United States)

    Park, Sunmin; Kim, Da Sol; Kang, Sunna; Daily, James W

    2011-02-01

    Ketogenic diets (KTD) are reported to have beneficial effects on the regulation of energy and glucose homeostasis, but remain controversial. We investigated the effects of KTD and ketones on insulin resistance and secretion in non-obese type 2 diabetic rats and their mechanism. KTD (82% energy as fat), intraperitoneal injection of β-hydroxybutyrate (IHB; 150 mg/kg bw/12 h) with a control diet (COD; 20% energy as fat) or saline injection with COD was given to 90% pancreatectomized (Px) diabetic rats for five weeks. KTD increased epididymal fat pads and serum leptin levels without increasing energy intake, but IHB decreased them. KTD, but not IHB, attenuated hypothalamic signal transducer and activator of transcription 3 and 5'-adenosine monophosphate-activated protein kinase (AMPK) phosphorylation in KTD. Serum glucagon levels were markedly higher in the KTD group than in other groups. During an oral glucose tolerance test, serum glucose levels slowly increased until 80 min in the KTD group and then decreased very slowly. Insulin secretion capacity during a hyperglycemic clamp was significantly lower in the IHB group than in other groups. However, a euglycemic hyperinsulinemic clamp revealed that KTD decreased glucose infusion rates and increased hepatic glucose output in hyperinsulinemic states while IHB had opposite effects to KTD. The increased hepatic glucose output in KTD was associated with increased hepatic phosphoenolpyruvate carboxykinase expression through attenuated tyrosine phosphorylation of IRS2 and phosphorylation of Akt(Ser473). Hepatic AMPK(Thr172) phosphorylation was reduced in KTD. In conclusion, KTD impairs energy and glucose homeostasis by exacerbating insulin resistance and attenuating hypothalamic leptin signaling in non-obese type 2 diabetic rats. These changes are not associated with increased serum ketone levels.

  7. QCM-4, a 5-HT₃ receptor antagonist ameliorates plasma HPA axis hyperactivity, leptin resistance and brain oxidative stress in depression and anxiety-like behavior in obese mice.

    Science.gov (United States)

    Kurhe, Yeshwant; Mahesh, Radhakrishnan; Devadoss, Thangaraj

    2015-01-02

    Several preclinical studies have revealed antidepressant and anxiolytic-like effect of 5-HT3 receptor antagonists. In our earlier study, we have reported the antidepressive-like effect of 3-methoxy-N-p-tolylquinoxalin-2-carboxamide (QCM-4) in obese mice subjected to chronic stress. The present study deals with the biochemical mechanisms associated with depression co-morbid with obesity. Mice were fed with high fat diet (HFD) for 14 weeks, further subjected for treatment with QCM-4 (1 and 2mg/kg p.o.) and standard antidepressant escitalopram (ESC) (10mg/kg p.o.) for 28 days. Behavioral assays for depression such as sucrose preference test (SPT), forced swim test (FST) and for anxiety such as light and dark test (LDT) and hole board test (HBT) were performed in obese mice. Biochemical assessments including plasma leptin and corticosterone concentration followed by brain oxidative stress parameters malonaldehyde (MDA) and reduced glutathione (GSH) were performed. Results confirmed that QCM-4 exhibits antidepressive effect by increasing the sucrose consumption in SPT, reducing immobility time in FST and anxiolytic effect by increasing transitions and time in light chamber in LDT, increasing head dip and crossing score in HBT. Furthermore, QCM-4 attenuated the hypothalamic-pituitary-adrenal (HPA) axis hyperactivity by reducing the plasma corticosterone, reversing altered plasma leptin, restoring the imbalance of brain MDA and GSH concentration. In conclusion, QCM-4 showed antidepressive and anxiolytic effect by reversing the behavioral alterations that were supported by biochemical estimations in obese mice. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Dietary proteins in obesity and in diabetes.

    Science.gov (United States)

    Keller, Ulrich

    2011-03-01

    Dietary proteins influence body weight by affecting four targets for body weight regulation: satiety, thermogenesis, energy efficiency, and body composition. Protein ingestion results in higher ratings of satiety than equicaloric amounts of carbohydrates or fat. Their effect on satiety is mainly due to oxidation of amino acids fed in excess; this effect is higher with ingestion of specific "incomplete" proteins (vegetal) than with animal proteins. Diet-induced thermogenesis is higher for proteins than for other macronutrients. The increase in energy expenditure is caused by protein and urea synthesis and by gluconeogenesis. This effect is higher with animal proteins containing larger amounts of essential amino acids than with vegetable proteins. Specifically, diet-induced thermogenesis increases after protein ingestion by 20 - 30 %, but by only 5 - 10 % after carbohydrates and 0 - 5 % after ingestion of fat. Consumption of higher amounts of protein during dietary treatment of obesity resulted in greater weight loss than with lower amounts of protein in dietary studies lasting up to one year. During weight loss and decreased caloric intake, a relatively increased protein content of the diet maintained fat-free mass (i. e. muscle mass) and increased calcium balance, resulting in preservation of bone mineral content. This is of particular importance during weight loss after bariatric surgery because these patients are at risk for protein malnutrition. Adequate dietary protein intake in diabetes type 2 is of specific importance since proteins are relatively neutral with regard to glucose and lipid metabolism, and they preserve muscle and bone mass, which may be decreased in subjects with poorly controlled diabetes. Ingestion of dietary proteins in diabetes type 1 exerts a delayed postprandial increase in blood glucose levels due to protein-induced stimulation of pancreatic glucagon secretion. Higher than minimal amounts of protein in the diet needed for nitrogen

  9. The Gene-Lifestyle Interaction on Leptin Sensitivity and Lipid Metabolism in Adults: A Population Based Study

    Directory of Open Access Journals (Sweden)

    Harry Freitag Luglio

    2017-07-01

    Full Text Available Background: Obesity has been associated with leptin resistance and this might be caused by genetic factors. The aim of this study was to investigate the gene-lifestyle interaction between −866G/A UCP2 (uncoupling protein 2 gene polymorphism, dietary intake and leptin in a population based study. Methods: This is a cross sectional study conducted in adults living at urban area of Yogyakarta, Indonesia. Data of adiposity, lifestyle, triglyceride, high density lipoprotein (HDL cholesterol, leptin and UCP2 gene polymorphism were obtained in 380 men and female adults. Results: UCP2 gene polymorphism was not significantly associated with adiposity, leptin, triglyceride, HDL cholesterol, dietary intake and physical activity (all p > 0.05. Leptin was lower in overweight subjects with AA + GA genotypes than those with GG genotype counterparts (p = 0.029. In subjects with AA + GA genotypes there was a negative correlation between leptin concentration (r = −0.324; p < 0.0001 and total energy intake and this correlation was not seen in GG genotype (r = −0.111; p = 0.188. Conclusions: In summary, we showed how genetic variation in −866G/A UCP2 affected individual response to leptin production. AA + GA genotype had a better leptin sensitivity shown by its response in dietary intake and body mass index (BMI and this explained the protective effect of A allele to obesity.

  10. The Gene-Lifestyle Interaction on Leptin Sensitivity and Lipid Metabolism in Adults: A Population Based Study.

    Science.gov (United States)

    Luglio, Harry Freitag; Sulistyoningrum, Dian Caturini; Huriyati, Emy; Lee, Yi Yi; Wan Muda, Wan Abdul Manan

    2017-07-07

    Obesity has been associated with leptin resistance and this might be caused by genetic factors. The aim of this study was to investigate the gene-lifestyle interaction between -866G/A UCP2 (uncoupling protein 2) gene polymorphism, dietary intake and leptin in a population based study. This is a cross sectional study conducted in adults living at urban area of Yogyakarta, Indonesia. Data of adiposity, lifestyle, triglyceride, high density lipoprotein (HDL) cholesterol, leptin and UCP2 gene polymorphism were obtained in 380 men and female adults. UCP2 gene polymorphism was not significantly associated with adiposity, leptin, triglyceride, HDL cholesterol, dietary intake and physical activity (all p > 0.05). Leptin was lower in overweight subjects with AA + GA genotypes than those with GG genotype counterparts ( p = 0.029). In subjects with AA + GA genotypes there was a negative correlation between leptin concentration ( r = -0.324; p correlation was not seen in GG genotype ( r = -0.111; p = 0.188). In summary, we showed how genetic variation in -866G/A UCP2 affected individual response to leptin production. AA + GA genotype had a better leptin sensitivity shown by its response in dietary intake and body mass index (BMI) and this explained the protective effect of A allele to obesity.

  11. Plasma leptin concentration in dogs with diabetes mellitus.

    Science.gov (United States)

    Nishii, Naohito; Yamasaki, Miho; Takasu, Masaki; Honjoh, Tsutomu; Shibata, Haruki; Otsuka, Yoshihiko; Takashima, Satoshi; Ohba, Yasunori; Kitagawa, Hitoshi

    2010-06-01

    The plasma leptin concentration was evaluated in dogs with diabetes mellitus. Twenty normal and sixteen diabetic dogs were divided into nonobese and obese groups based on body condition score, respectively. The obese normal dogs had significantly higher plasma leptin concentrations than the nonobese normal dogs, whereas there was no significant difference between the nonobese and obese diabetic dogs. In addition, the plasma leptin concentration in the obese diabetic dogs was significantly lower than that in the obese normal dogs. In conclusion, the plasma leptin concentrations in the diabetic dogs were affected by factors other than adiposity.

  12. Serotonin transporter (SERT and translocator protein (TSPO expression in the obese ob/ob mouse

    Directory of Open Access Journals (Sweden)

    Santini Ferruccio

    2011-02-01

    Full Text Available Abstract Background An ever growing body of evidences is emerging concerning metabolism hormones, neurotransmitters or stress-related biomarkers as effective modulators of eating behavior and body weight in mammals. The present study sought at examining the density and affinity of two proteins related to neurotransmission and cell metabolism, the serotonin transporter SERT and the cholesterol import-benzodiazepine site TSPO (translocator protein, in a rodent leptin-lacking mutant, the obese ob/ob mouse. Binding studies were thus carried out in brain or peripheral tissues, blood platelets (SERT and kidneys (TSPO, of ob/ob and WT mice supplied with a standard diet, using the selective radiochemical ligands [3H]-paroxetine and [3H]-PK11195. Results We observed comparable SERT number or affinity in brain and platelets of ob/ob and WT mice, whilst a significantly higher [3H]-PK11195 density was reported in the brain of ob/ob animals. TSPO binding parameters were similar in the kidneys of all tested mice. By [3H]-PK11195 autoradiography of coronal hypothalamic-hippocampal sections, an increased TSPO signal was detected in the dentate gyrus (hippocampus and choroids plexus of ob/ob mice, without appreciable changes in the cortex or hypothalamic-thalamic regions. Conclusions These findings show that TSPO expression is up-regulated in cerebral regions of ob/ob leptin-deficient mice, suggesting a role of the translocator protein in leptin-dependent CNS trophism and metabolism. Unchanged SERT in mutant mice is discussed herein in the context of previous literature as the forerunner to a deeper biochemical investigation.

  13. Central exercise action increases the AMPK and mTOR response to leptin.

    Directory of Open Access Journals (Sweden)

    Eduardo R Ropelle

    Full Text Available AMP-activated protein kinase (AMPK and mammalian Target of Rapamycin (mTOR are key regulators of cellular energy balance and of the effects of leptin on food intake. Acute exercise is associated with increased sensitivity to the effects of leptin on food intake in an IL-6-dependent manner. To determine whether exercise ameliorates the AMPK and mTOR response to leptin in the hypothalamus in an IL-6-dependent manner, rats performed two 3-h exercise bouts, separated by one 45-min rest period. Intracerebroventricular IL-6 infusion reduced food intake and pretreatment with AMPK activators and mTOR inhibitor prevented IL-6-induced anorexia. Activators of AMPK and fasting increased food intake in control rats to a greater extent than that observed in exercised ones, whereas inhibitor of AMPK had the opposite effect. Furthermore, the reduction of AMPK and ACC phosphorylation and increase in phosphorylation of proteins involved in mTOR signal transduction, observed in the hypothalamus after leptin infusion, were more pronounced in both lean and diet-induced obesity rats after acute exercise. Treatment with leptin reduced food intake in exercised rats that were pretreated with vehicle, although no increase in responsiveness to leptin-induced anorexia after pretreatment with anti-IL6 antibody, AICAR or Rapamycin was detected. Thus, the effects of leptin on the AMPK/mTOR pathway, potentiated by acute exercise, may contribute to appetite suppressive actions in the hypothalamus.

  14. Leptin as local inflammatory marker in COPD.

    Science.gov (United States)

    Broekhuizen, R; Vernooy, J H J; Schols, A M W J; Dentener, M A; Wouters, E F M

    2005-01-01

    Chronic inflammation of the lung is a characteristic finding in chronic obstructive pulmonary disease (COPD). Leptin is a pleiotropic cytokine thought to play a role in host response to inflammation. As recent studies have shown that leptin receptors are present in the lung, this study aimed to determine if leptin is detectable in induced sputum of COPD patients and if there is a relationship between leptin and other inflammatory markers in sputum. Sputum was induced in 14 male patients with moderate COPD (FEV1: 56 (15) % pred.). Leptin, total tumour necrosis factor (TNF)-alpha, and C-reactive protein (CRP) were analyzed in induced sputum supernatant by ELISA. Leptin was also determined in EDTA plasma. Leptin was detectable in induced sputum of 10 COPD patients. A significant relationship was found between sputum leptin and CRP (r = 0.943, P leptin and sputum leptin were inversely correlated (r = -0.643, P leptin is detectable in induced sputum of patients with moderate COPD and is related to other inflammatory markers. The observed correlations between leptin and inflammatory markers in sputum may indicate that leptin is involved in the local inflammatory response in COPD.

  15. Searching for Evidence of an Anti-Inflammatory Diet in Children: A Systematic Review of Randomized Controlled Trials for Pediatric Obesity Interventions With a Focus on Leptin, Ghrelin, and Adiponectin.

    Science.gov (United States)

    Lewis, Kimberly A; Brown, Sharon A

    2017-10-01

    To address the complex phenomenon of pediatric obesity, one must understand the physiological mechanisms regulating energy intake and inflammation. The peptide hormones leptin, ghrelin, and adiponectin are involved in both, but their functions are dysregulated in obesity. The purpose of this systematic review is (1) to characterize studies of nutrition interventions for weight management in children who measure these peptides as outcomes, (2) to assess risk of bias in the studies, and (3) to determine the relationships between these peptides and body mass index (BMI). Eligibility Criteria: Peer-reviewed articles written in English, published in 2001-2016, and describing randomized controlled trials of pediatric interventions involving a nutrition component with the outcome measures leptin, ghrelin, and/or adiponectin were included. Articles were excluded if the intervention involved pharmaceuticals, supplements, infant formula, breastfeeding, or surgery. The 25 international studies represented 2,153 obese children. Ten diets were identified. Successful interventions included both structured exercise and hypocaloric dietary components, with or without counseling, resistance training, or medical components. Direct measures of adiposity were used in 69% of studies. Comparison group designs were disparate. Leptin levels decreased as BMI decreased. Evidence regarding the relationships of ghrelin and adiponectin with BMI was inconclusive. Despite known effects of maturation on hormones, studies did not consistently differentiate findings by maturational stage. Common anti-inflammatory and disease risk modification diets were missing or underrepresented. Studies that include children with comorbidities are needed. BMI and leptin levels have a positive relationship, but evidence on ghrelin and adiponectin was inconclusive.

  16. The association of serum leptin levels with metabolic diseases

    Directory of Open Access Journals (Sweden)

    Jen-Pi Tsai

    2017-01-01

    Full Text Available Leptin is a 167-amino-acid protein released by white adipose tissue and encoded by the obese gene. It has a role as a negative regulator of appetite control through sending a satiety signal to act on receptors within the hypothalamus. At normal levels, leptin can exert its effects on weight regulation according to white fat mass, induce sodium excretion, maintain vascular tone, and repair the myocardium. Beyond these effects, elevated serum leptin levels have been implicated in the pathogenesis of metabolic syndrome, diabetes mellitus, hypertension, and multiple cardiovascular diseases. In addition, hyperleptinemia had been reported to contribute to renal diseases through multiple mechanisms resulting in glomerulopathy presenting with a decreased glomerular filtration rate, increased albuminuria, and related clinical symptoms, which are pathophysiological features of chronic kidney disease. Because these cardiovascular and metabolic disorders are great challenges for physicians, understanding the related pathophysiological association with leptin might become a valuable aid in handling patients in daily clinical practice. This review will discuss the roles of leptin in the regulation of biological functions of multiple organs beyond the maintenance of feeding and metabolism.

  17. O papel dos hormônios leptina e grelina na gênese da obesidade The role of leptin and ghrelin on the genesis of obesity

    Directory of Open Access Journals (Sweden)

    Carla Eduarda Machado Romero

    2006-02-01

    Full Text Available A prevalência da obesidade está aumentando e estudos prospectivos mostram que, em 2025, o Brasil será o quinto país do mundo a apresentar problemas de obesidade em sua população. A etiologia da obesidade não é de fácil identificação, uma vez que a mesma é caracterizada como uma doença multifatorial, ou seja, diversos fatores estão envolvidos em sua gênese, incluindo fatores genéticos, psicológicos, metabólicos e ambientais. Pesquisas recentes na área de metabolismo mostram que o adipócito é capaz de sintetizar várias substâncias e, diferentemente do que se supunha anteriormente, o tecido adiposo não é apenas um sítio de armazenamento de triglicérides, é hoje considerado um órgão endócrino. Dentre as diversas substâncias sintetizadas pelo adipócito, destacam-se a adiponectina, a angiotensina e a leptina. A leptina é um petídeo que desempenha importante papel na regulação da ingestão alimentar e no gasto energético, gerando um aumento na queima de energia e diminuindo a ingestão alimentar. Além dos avanços no estudo da célula adiposa, um novo hormôrnio relacionado ao metabolismo foi descoberto recentemente, a grelina. A grelina é um peptídeo produzido nas células do estômago, e está diretamente envolvida na regulação do balanço energético a curto prazo. Assim, este artigo abordará o papel da leptina e da grelina no controle do peso corporal e as limitações que ainda existem para tratar a obesidade em humanos.The prevalence of obesity is rising around the world and prospective studies show that in 2025, Brazil will be the fifth country in the world to have obesity problems. Multifactorial factors are involved in the genesis of obesity including genetic, psychological, metabolic and environmental factors. Recently, adipocytes have been considered an endocrine tissue capable of producing several substances, including adiponectin, angiotensin and leptin. Leptin is the main peptide produced by

  18. Correlation between maternal and cord blood leptin and fetal growth

    African Journals Online (AJOL)

    SERVER

    2007-09-05

    Sep 5, 2007 ... IL -2 and growth hormone. The long form of the leptin receptor functions similarly to cytokine ... regulation of leptin synthesis and the risk for obesity in the offspring. In species such as the human and sheep, ..... Hormonal regulation of leptin levels in the fetus and neonate might be different from the endocrine ...

  19. Circulating leptin and thyroid dysfunction

    DEFF Research Database (Denmark)

    Zimmermann-Belsing, Tina; Brabant, Georg; Holst, Jens Juul

    2003-01-01

    the fields of nutrition, metabolism and endocrinology. Leptin is accepted as an adipose signal, and even though the underlying mechanisms are not fully clarified, leptin, in addition to the thyroid hormones, is believed to be involved in regulation during the switch from the fed to the starved state....... It is not clear whether leptin and the melanocortin pathways interact with the thyroid axis under physiological conditions other than during starvation or in response to severe illness, both states in which the hypothalamo-pituitary-thyroid axis may be severely suppressed. In addition to the suggested central...... relationship between leptin and thyroid hormones, there might also be a peripheral relationship although this effect is not clear. Both thyroid hormones and leptin might be involved in the adaptive thermogenesis through mitochondrial uncoupling proteins and heat production because both thyroxine...

  20. Mother and Infant Body Mass Index, Breast Milk Leptin and Their Serum Leptin Values

    Directory of Open Access Journals (Sweden)

    Francesco Savino

    2016-06-01

    Full Text Available Purpose: This study investigates correlations between mother and infant Body Mass Index (BMI, their serum leptin values and breast milk leptin concentration in early infancy. Subjects and Methods: 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. Results: 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. Conclusion: 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.

  1. Lipid profile and levels of homocysteine, leptin, fibrinogen and C-reactive protein in hyperthyroid patients before and after treatment

    Directory of Open Access Journals (Sweden)

    Emine Sütken

    2010-03-01

    Full Text Available Objectives: The present study was carried out to determine whether thyroid hormones affect lipid profile and levels of erithrocyte sedimentation rate (ESR, serum total homocysteine (t-hcy, leptin, fibrinogen, C-reactive protein (CRP in patients with hyperthyroidism.Materials and methods: This study was carried out on 23 hyperthroid subjects (3 men / 20 women, mean age 41.8 ± 2.4 years. Serum levels of homocysteine, leptin, fibrinogen, CRP, total cholesterol (TC, high-density lipoprotein cholesterol (HDL-C, low-density lipoprotein cholesterol (LDL-C and ESR were measured and body mass index (BMI were calculated before and after treatment of hyperthyroidism.Results: Pretreatment t-hcy, TC, LDL-C, HDL-C levels and BMI of patients were significantly lower than those of the post-treatment (p<0.001, for each variable. However, fibrinogen and ESR decreased after the treatment (p<0.001 and p<0.05, respectively. There were no differences in leptin and CRP levels between pre- and post-treatment periods. Pre and post treatment TC and LDL-C levels were negatively correlated with free triiodothyronine (fT3 levels (r=-0.588, p<0.01; r=-0.534, p<0.01; r=-0.543, p<0.01 and r =-0.653, p<0.01, respectively. Pre-treatment HDL-C was inversely correlated with TSH (r=-0.423, p<0.05. Pre-post- treatment LDL-C was negatively correlated with free thyroxine (fT4 levels (r=-0.536, p<0.001 and r=- 0.422, p<0.05 respectively. Pre-treatment TC was inversely correlated with fT4 (r=-0.590, p<0.01.Conclusion: Hyperthyroidism is associated with high plasma fibrinogen and ESR levels. Elevated plasma fibrinogen and ESR levels may be a possible explanation for the high cardiovascular morbidity among hyperthyroidic subjects. These changes may reflect low-grade inflammation or disturbances in coagulation in hyperthyroidism.

  2. Hypoxic Living and Exercise Training Alter Adipose Tissue Leptin/Leptin Receptor in Rats

    Directory of Open Access Journals (Sweden)

    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.

  3. Relation of Absolute or Relative Adiposity to Insulin Resistance, Retinol Binding Protein-4, Leptin, and Adiponectin in Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    You Lim Kim

    2012-12-01

    Full Text Available BackgroundCentral fat mass (CFM correlates with insulin resistance and increases the risk of type 2 diabetes and cardiovascular complications; however, peripheral fat mass (PFM is associated with insulin sensitivity. The aim of this study was to investigate the relation of absolute and relative regional adiposity to insulin resistance index and adipokines in type 2 diabetes.MethodsTotal of 83 overweighted-Korean women with type 2 diabetes were enrolled, and rate constants for plasma glucose disappearance (KITT and serum adipokines, such as retinol binding protein-4 (RBP4, leptin, and adiponectin, were measured. Using dual X-ray absorptiometry, trunk fat mass (in kilograms was defined as CFM, sum of fat mass on the lower extremities (in kilograms as PFM, and sum of CFM and PFM as total fat mass (TFM. PFM/TFM ratio, CFM/TFM ratio, and PFM/CFM ratio were defined as relative adiposity.ResultsMedian age was 55.9 years, mean body mass index 27.2 kg/m2, and mean HbA1c level 7.12±0.84%. KITT was positively associated with PMF/TFM ratio, PMF/CFM ratio, and negatively with CFM/TFM ratio, but was not associated with TFM, PFM, or CFM. RBP4 levels also had a significant relationship with PMF/TFM ratio and PMF/CFM ratio. Adiponectin, leptin, and apolipoprotein A levels were related to absolute adiposity, while only adiponectin to relative adiposity. In correlation analysis, KITT in type 2 diabetes was positively related with HbA1c, fasting glucose, RBP4, and free fatty acid.ConclusionThese results suggest that increased relative amount of peripheral fat mass may aggravate insulin resistance in type 2 diabetes.

  4. Genome-wide meta-analysis uncovers novel loci influencing circulating leptin levels

    DEFF Research Database (Denmark)

    Kilpeläinen, Tuomas O; Carli, Jayne F Martin; Skowronski, Alicja A

    2016-01-01

    Leptin is an adipocyte-secreted hormone, the circulating levels of which correlate closely with overall adiposity. Although rare mutations in the leptin (LEP) gene are well known to cause leptin deficiency and severe obesity, no common loci regulating circulating leptin levels have been uncovered...

  5. Comparison with ancestral diets suggests dense acellular carbohydrates promote an inflammatory microbiota, and may be the primary dietary cause of leptin resistance and obesity

    Science.gov (United States)

    Spreadbury, Ian

    2012-01-01

    A novel hypothesis of obesity is suggested by consideration of diet-related inflammation and evolutionary medicine. The obese homeostatically guard their elevated weight. In rodent models of high-fat diet-induced obesity, leptin resistance is seen initially at vagal afferents, blunting the actions of satiety mediators, then centrally, with gastrointestinal bacterial-triggered SOCS3 signaling implicated. In humans, dietary fat and fructose elevate systemic lipopolysaccharide, while dietary glucose also strongly activates SOCS3 signaling. Crucially however, in humans, low-carbohydrate diets spontaneously decrease weight in a way that low-fat diets do not. Furthermore, nutrition transition patterns and the health of those still eating diverse ancestral diets with abundant food suggest that neither glycemic index, altered fat, nor carbohydrate intake can be intrinsic causes of obesity, and that human energy homeostasis functions well without Westernized foods containing flours, sugar, and refined fats. Due to being made up of cells, virtually all “ancestral foods” have markedly lower carbohydrate densities than flour- and sugar-containing foods, a property quite independent of glycemic index. Thus the “forgotten organ” of the gastrointestinal microbiota is a prime candidate to be influenced by evolutionarily unprecedented postprandial luminal carbohydrate concentrations. The present hypothesis suggests that in parallel with the bacterial effects of sugars on dental and periodontal health, acellular flours, sugars, and processed foods produce an inflammatory microbiota via the upper gastrointestinal tract, with fat able to effect a “double hit” by increasing systemic absorption of lipopolysaccharide. This model is consistent with a broad spectrum of reported dietary phenomena. A diet of grain-free whole foods with carbohydrate from cellular tubers, leaves, and fruits may produce a gastrointestinal microbiota consistent with our evolutionary condition

  6. Overexpression of leptin receptor predicts an unfavorable outcome in Middle Eastern ovarian cancer

    Directory of Open Access Journals (Sweden)

    Bavi Prashant

    2009-09-01

    Full Text Available Abstract Background Recent epidemiological studies have suggested that obesity is associated with ovarian cancer. Obesity hormone leptin and its receptor (Ob-R contribute to tumor development by enhancing cell growth and survival. This study was design to investigate the prevalence of leptin and Ob-R in Middle Eastern epithelial ovarian cancer (EOC and to analyze the role of leptin and the mechanisms under its action in EOC tissue sample and cell lines. Methods The expression of leptin and Ob-R was examined by immunohistochemistry in a tissue microarray of 156 EOC samples. Proliferation of EOC cells in response to leptin was assessed by MTT assays, and its anti-apoptotic effects were determined by flow cytometry. Effect of leptin on PI3K/AKT signaling pathway was further determined by western blotting. Results In clinical samples, Ob-R overexpression was seen in 59.2% EOCs and was significantly associated with poor progression free survival (p = 0.0032. Furthermore, Ob-R expression was associated with anti apoptotic proteins Bcl-XL (p = 0.0035 and XIAP (p = 0.0001. In vitro analysis using EOC cell lines showed that leptin stimulated cell proliferation and inhibits apoptosis via activation of PI3K/AKT signaling pathway. Inhibition of PI3K activity by LY294002, a specific inhibitor of PI3-kinase abrogated leptin mediated PI3K/AKT signaling. Gene silencing of Ob-R with Ob-R siRNA in EOC cells resulted in down regulation of phospho-AKT and its down stream targets. Conclusion Our findings have potential clinical implication for EOC development and progression.

  7. The role of leptin in human lipid and glucose metabolism: the effects of acute recombinant human leptin infusion in young healthy males

    DEFF Research Database (Denmark)

    Wolsk, Emil; Mygind, Helene; Grøndahl, Thomas S

    2011-01-01

    Obese and lean humans treated with leptin have not experienced convincing weight-loss results compared with the dramatic weight losses observed in obese rodents.......Obese and lean humans treated with leptin have not experienced convincing weight-loss results compared with the dramatic weight losses observed in obese rodents....

  8. Greater effects of high- compared with moderate-intensity interval training on cardio-metabolic variables, blood leptin concentration and ratings of perceived exertion in obese adolescent females

    Directory of Open Access Journals (Sweden)

    G Racil

    2016-04-01

    Full Text Available This study examined the effects of high- vs. moderate-intensity interval training on cardiovascular fitness, leptin levels and ratings of perceived exertion (RPE in obese female adolescents. Forty-seven participants were randomly assigned to one of three groups receiving either a 1:1 ratio of 15 s of effort comprising moderate-intensity interval training (MIIT at 80% maximal aerobic speed: MAS or high-intensity interval training (HIIT at 100% MAS, with matched 15 s recovery at 50% MAS, thrice weekly, or a no-training control group. The HIIT and MIIT groups showed improved (p˂0.05 body mass (BM, BMI Z-score, and percentage of body fat (%BF. Only the HIIT group showed decreased waist circumference (WC (p=0.017. The effect of exercise on maximal oxygen uptake (VO2max was significant (p=0.019, ES=0.48 and p=0.010, ES=0.57, HIIT and MIIT, respectively. The decrease of rate-pressure product (RPP (p<0.05, ES=0.53 and ES=0.46, HIIT and MIIT, respectively followed the positive changes in resting heart rate and blood pressures. Blood glucose, insulin level and the homeostasis model assessment index for insulin decreased (p<0.05 in both training groups. Significant decreases occurred in blood leptin (p=0.021, ES=0.67 and p=0.011, ES=0.73 and in RPE (p=0.001, ES=0.76 and p=0.017, ES=0.57 in HIIT and MIIT, respectively. In the post-intervention period, blood leptin was strongly associated with %BF (p<0.001 and VO2max (p<0.01 in the HIIT and MIIT groups, respectively, while RPE was strongly associated with BM (p<0.01 in the HIIT group. The results suggest that high-intensity interval training may produce more positive effects on health determinants in comparison with the same training mode at a moderate intensity.

  9. The impact of leptin on perinatal development and psychopathology.

    Science.gov (United States)

    Valleau, Jeanette C; Sullivan, Elinor L

    2014-11-01

    Leptin has long been associated with metabolism as it is a critical regulator of both food intake and energy expenditure, but recently, leptin dysregulation has been proposed as a mechanism of psychopathology. This review discusses the evidence supporting a role for leptin in mental health disorders and describes potential mechanisms that may underlie this association. Leptin plays a critical role in pregnancy and in fetal growth and development. Leptin's role and profile during development is examined in available human studies, and the validity of applying studies conducted in animal models to the human population are discussed. Rodents experience a postnatal leptin surge, which does not occur in humans or larger animal models. This suggests that further research using large mammal models, which have a leptin profile across pregnancy and development similar to humans, are of high importance. Maternal obesity and hyperleptinemia correlate with increased leptin levels in the umbilical cord, placenta, and fetus. Leptin levels are thought to impact fetal brain development; likely by activating proinflammatory cytokines that are known to impact many of the neurotransmitter systems that regulate behavior. Leptin is likely involved in behavioral regulation as leptin receptors are widely distributed in the brain, and leptin influences cortisol release, the mesoaccumbens dopamine pathway, serotonin synthesis, and hippocampal synaptic plasticity. In humans, both high and low levels of leptin are reported to be associated with psychopathology. This inconsistency is likely due to differences in the metabolic state of the study populations. Leptin resistance, which occurs in the obese state, may explain how both high and low levels of leptin are associated with psychopathology, as well as the comorbidity of obesity with numerous mental illnesses. Leptin resistance is likely to influence disorders such as depression and anxiety where high leptin levels have been correlated

  10. 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.

  11. Elsevier Trophoblast Research Award lecture: Molecular mechanisms underlying estrogen functions in trophoblastic cells--focus on leptin expression.

    Science.gov (United States)

    Gambino, Y P; Maymó, J L; Pérez Pérez, A; Calvo, J C; Sánchez-Margalet, V; Varone, C L

    2012-02-01

    The steroid hormone 17β-estradiol is an estrogen that influences multiple aspects of placental function and fetal development in humans. During early pregnancy it plays a role in the regulation of blastocyst implantation, trophoblast differentiation and invasiveness, remodeling of uterine arteries, immunology and trophoblast production of hormones such as leptin. Estradiol exerts some effects through the action of classical estrogen receptors ERα and ERβ, which act as ligand-activated transcription factors and regulate gene expression. In addition, estradiol can elicit rapid responses from membrane-associated receptors, like activation of protein-kinase pathways. Thus, the cellular effects of estradiol will depend on the specific receptors expressed and the integration of their signaling events. Leptin, the 16,000MW protein product of the obese gene, was originally considered an adipocyte-derived signaling molecule for the central control of metabolism. However, pleiotropic effects of leptin have been identified in reproduction and pregnancy. The leptin gene is expressed in placenta, where leptin promotes proliferation and survival of trophoblastic cells. Expression of leptin in placenta is highly regulated by key pregnancy molecules as hCG and estradiol. The aim of this paper is to review the molecular mechanisms underlying estrogen functions in trophoblastic cells; focusing on mechanisms involved in estradiol regulation of placental leptin expression. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Survivin upregulation, dependent on leptin-EGFR-Notch1 axis, is essential for leptin induced migration of breast carcinoma cells

    Science.gov (United States)

    Knight, Brandi B.; Oprea-Ilies, Gabriela M.; Nagalingam, Arumugam; Yang, Lily; Cohen, Cynthia; Saxena, Neeraj K.; Sharma, Dipali

    2012-01-01

    Obese breast cancer patients exhibit a higher risk for larger tumor burden and increased metastasis. Molecular effects of obesity on carcinogenesis are mediated by autocrine and paracrine effects of adipocytokine leptin. Leptin participates in tumor progression and metastasis of human breast. We show that leptin induces clonogenicity and migration potential of breast cancer cells. We found that survivin expression is induced in response to leptin. In this study, we examine the role and leptin-mediated regulation of survivin. Leptin treatment leads to survivin upregulation, due in part to the activation of Notch1 and release of transcriptionally active Notch1-intracellular-domain (NICD). ChIP analysis show that NICD gets recruited to survivin promoter at CSL-binding-site in response to leptin treatment. Inhibition of Notch1 activity inhibits leptin-induced survivin upregulation. Leptin-induced transactivation of EGFR is involved in leptin-mediated Notch1 and survivin upregulation showing a novel upstream role of leptin-EGFR-Notch1 axis. We further show that leptin-induced migration of breast cancer cells requires survivin, as overexpression of survivin further increases, whereas silencing survivin abrogates leptin-induced migration. Using a pharmacological approach to inhibit survivin, we show that 3-hydroxy-3-methylglutaryl-coenzyme-A-reductase inhibitors (HRIs), lovastatin, can effectively inhibit leptin-induced survivin expression and migration. Importantly, leptin increased breast tumor growth in nude mice. These data show a novel role for survivin in leptin-induced migration and put forth pharmacological survivin inhibition as a potential novel therapeutic target. This conclusion is supported by in vivo data showing overexpression of leptin and survivin in epithelial cells of high grade ductal carcinoma in situ and high grade invasive carcinoma. PMID:21555376

  13. Leptin responses to bovine interferon- α and insulin in cattle

    African Journals Online (AJOL)

    Leptin is a protein synthesized and secreted mainly by adipose tissue. Peripheral administration of different inflammatory cytokines increases both leptin protein and mRNA expression in rodents. We previously showed that injection of lipopolysaccharide (LPS) and tumor necrosis factor alpha (TNF-α) did not affect leptin ...

  14. [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

  15. Protein and Calorie Restriction Contribute Additively to Protection from Renal Ischemia Reperfusion Injury Partly via Leptin Reduction in Male Mice123

    Science.gov (United States)

    Robertson, Lauren T; Treviño-Villarreal, J Humberto; Mejia, Pedro; Grondin, Yohann; Harputlugil, Eylul; Hine, Christopher; Vargas, Dorathy; Zheng, Hanqiao; Ozaki, C Keith; Kristal, Bruce S; Simpson, Stephen J; Mitchell, James R

    2015-01-01

    Background: Short-term dietary restriction (DR) without malnutrition preconditions against surgical stress in rodents; however, the nutritional basis and underlying nutrient/energy-sensing pathways remain poorly understood. Objectives: We investigated the relative contribution of protein restriction (PR) vs. calorie restriction (CR) to protection from renal ischemia reperfusion injury (IRI) and changes in organ-autonomous nutrient/energy-sensing pathways and hormones underlying beneficial effects. Methods: Mice were preconditioned on experimental diets lacking total calories (0–50% CR) or protein/essential amino acids (EAAs) vs. complete diets consumed ad libitum (AL) for 1 wk before IRI. Renal outcome was assessed by serum markers and histology and integrated over a 2-dimensional protein/energy landscape by geometric framework analysis. Changes in renal nutrient/energy-sensing signal transduction and systemic hormones leptin and adiponectin were also measured. The genetic requirement for amino acid sensing via general control non-derepressible 2 (GCN2) was tested with knockout vs. control mice. The involvement of the hormone leptin was tested by injection of recombinant protein vs. vehicle during the preconditioning period. Results: CR-mediated protection was dose dependent up to 50% with maximal 2-fold effect sizes. PR benefits were abrogated by EAA re-addition and additive with CR, with maximal benefits at any given amount of CR occurring with a protein-free diet. GCN2 was not required for functional benefits of PR. Activation and repression of nutrient/energy-sensing kinases, AMP-activated protein kinase (AMPK) and mechanistic target of rapamycin complex 1 (mTORC1), respectively, on PR reflected a state of negative energy balance, paralleled by 13% weight loss and an 87% decrease in leptin, independent of calorie intake. Recombinant leptin administration partially abrogated benefits of dietary preconditioning against renal IRI. Conclusions: In male mice, PR

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

    Directory of Open Access Journals (Sweden)

    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.

  17. Maternal protein and folic acid intake during gestation does not program leptin transcription or serum concentration in rat progeny

    OpenAIRE

    Chmurzynska, Agata; Stachowiak, Monika; Pruszynska-Oszmalek, Ewa

    2011-01-01

    Maternal nutrition during gestation influences the development of the fetus, thereby determining its phenotype, including nutrient metabolism, appetite, and feeding behavior. The control of appetite is a very complex process and can be modulated by orexigenic and anorexigenic mediators such as leptin, which is involved in the regulation of energy homeostasis by controlling food intake and energy expenditure. Leptin transcription and secretion are regulated by numerous factors, nutrition being...

  18. Calcineurin /NFAT activation-dependence of leptin synthesis and vascular growth in response to mechanical stretch

    Directory of Open Access Journals (Sweden)

    Nadia Soudani

    2016-09-01

    Full Text Available Background and Aims- Hypertension and obesity are important risk factors of cardiovascular disease. They are both associated with high leptin levels and have been shown to promote vascular hypertrophy, through the RhoA/ROCK and ERK1/2 phosphorylation. Calcineurin/NFAT activation also induces vascular hypertrophy by upregulating various genes. This study aimed to decipher whether a crosstalk exists between the RhoA/ROCK pathway, Ca+2/calcineurin/NFAT pathway, and ERK1/2 phosphorylation in the process of mechanical stretch-induced vascular smooth muscle cell (VSMC hypertrophy and leptin synthesis. Methods and Results- Rat portal vein (RPV organ culture was used to investigate the effect of mechanical stretch and exogenous leptin (3.1 nM on VSMC hypertrophy and leptin synthesis. Results showed that stretching the RPV significantly upregulated leptin secretion, mRNA and protein expression, which were inhibited by the calcium channel blocker nifedipine (10 μM, the selective calcineurin inhibitor FK506 (1 nM and the ERK1/2 inhibitor PD98059 (1 μM. The transcription inhibitor actinomycin D (0.1M and the translation inhibitor cycloheximide (1 mM significantly decreased stretch-induced leptin protein expression. Mechanical stretch or leptin caused an increase in wet weight changes and protein synthesis, considered as hypertrophic markers, while they were inhibited by FK506 (0.1 nM; 1 nM. In addition, stretch or exogenous leptin significantly increased calcineurin activity and MCIP1 expression whereas leptin induced NFAT nuclear translocation in VSMCs. Moreover, in response to stretch or exogenous leptin, the Rho inhibitor C3 exoenzyme (30 ng/mL, the ROCK inhibitor Y-27632 (10 μM, and the actin depolymerization agents Latrunculin B (50 nM and cytochalasin D (1 μM reduced calcineurin activation and NFAT nuclear translocation. ERK1/2 phosphorylation was inhibited by FK506 and C3. Conclusions- Mechanical stretch-induced VSMC hypertrophy and leptin

  19. Maternal low protein decreases leptin expression in the brains of the neonatal rat offspring

    Science.gov (United States)

    Prenatal exposure to a maternal low protein diet has been known to cause cognitive deficits in the adult progeny. Maternal low protein diets induce visual and spatial memmy impai1ment, deficits in learning and memo1y, as well as a host of behavioral abno1malities in the adult progeny. However, the u...

  20. Complementary Effects of Genetic Variations in LEPR on Body Composition and Soluble Leptin Receptor Concentration after 3-Month Lifestyle Intervention in Prepubertal Obese Children

    Directory of Open Access Journals (Sweden)

    Joanna Gajewska

    2016-05-01

    Full Text Available In obese individuals, weight loss might be affected by variants of the adipokine-encoding genes. We verified whether selected functional single nucleotide polymorphisms in LEP, LEPR and ADIPOQ are associated with changes in serum levels of the respective adipokines and weight loss in 100 prepubertal obese (SDS-BMI > 2 Caucasian children undergoing lifestyle intervention. Frequencies of the -2548G > A LEP, Q223R LEPR, K656N LEPR, -11377C > G and -11426A > G ADIPOQ polymorphisms were analyzed by restriction fragment length polymorphism. Serum adipokine and soluble leptin receptor (sOB-R concentrations were measured using the ELISA method. Among the analyzed polymorphisms, only LEPR polymorphisms were associated with changes of SDS-BMI or sOB-R concentrations in children after therapy. Carriers of the wild-type K665N and at least one minor Q223R allele had the greatest likelihood of losing weight (OR = 5.09, p = 0.006, an increase in sOB-R (ptrend = 0.022 and decrease in SDS-BMI correlated with the decrease of fat mass (p < 0.001. In contrast, carrying of the wild-type Q223R and at least one minor K665N allele were associated with a decrease in sOB-R concentrations and a decrease in SDS-BMI correlated with a decrease in fat-free mass (p = 0.002. We suggest that the combination of different LEPR variants, not a single variant, might determine predisposition to weight loss in the prepubertal period.

  1. Comparison with ancestral diets suggests dense acellular carbohydrates promote an inflammatory microbiota, and may be the primary dietary cause of leptin resistance and obesity

    Directory of Open Access Journals (Sweden)

    Spreadbury I

    2012-07-01

    Full Text Available Ian SpreadburyGastrointestinal Diseases Research Unit, Queen's University, Kingston, Ontario, CanadaAbstract: A novel hypothesis of obesity is suggested by consideration of diet-related inflammation and evolutionary medicine. The obese homeostatically guard their elevated weight. In rodent models of high-fat diet-induced obesity, leptin resistance is seen initially at vagal afferents, blunting the actions of satiety mediators, then centrally, with gastrointestinal bacterial-triggered SOCS3 signaling implicated. In humans, dietary fat and fructose elevate systemic lipopolysaccharide, while dietary glucose also strongly activates SOCS3 signaling. Crucially however, in humans, low-carbohydrate diets spontaneously decrease weight in a way that low-fat diets do not. Furthermore, nutrition transition patterns and the health of those still eating diverse ancestral diets with abundant food suggest that neither glycemic index, altered fat, nor carbohydrate intake can be intrinsic causes of obesity, and that human energy homeostasis functions well without Westernized foods containing flours, sugar, and refined fats. Due to being made up of cells, virtually all "ancestral foods" have markedly lower carbohydrate densities than flour- and sugar-containing foods, a property quite independent of glycemic index. Thus the "forgotten organ" of the gastrointestinal microbiota is a prime candidate to be influenced by evolutionarily unprecedented postprandial luminal carbohydrate concentrations. The present hypothesis suggests that in parallel with the bacterial effects of sugars on dental and periodontal health, acellular flours, sugars, and processed foods produce an inflammatory microbiota via the upper gastrointestinal tract, with fat able to effect a "double hit" by increasing systemic absorption of lipopolysaccharide. This model is consistent with a broad spectrum of reported dietary phenomena. A diet of grain-free whole foods with carbohydrate from cellular

  2. Obesity and kidney disease

    Directory of Open Access Journals (Sweden)

    Geraldo Bezerra da Silva Junior

    Full Text Available Abstract Obesity has been pointed out as an important cause of kidney diseases. Due to its close association with diabetes and hypertension, excess weight and obesity are important risk factors for chronic kidney disease (CKD. Obesity influences CKD development, among other factors, because it predisposes to diabetic nephropathy, hypertensive nephrosclerosis and focal and segmental glomerulosclerosis. Excess weight and obesity are associated with hemodynamic, structural and histological renal changes, in addition to metabolic and biochemical alterations that lead to kidney disease. Adipose tissue is dynamic and it is involved in the production of "adipokines", such as leptin, adiponectin, tumor necrosis factor-α, monocyte chemoattractant protein-1, transforming growth factor-β and angiotensin-II. A series of events is triggered by obesity, including insulin resistance, glucose intolerance, dyslipidemia, atherosclerosis and hypertension. There is evidence that obesity itself can lead to kidney disease development. Further studies are required to better understand the association between obesity and kidney disease.

  3. Reduced anorexigenic efficacy of leptin, but not of the melanocortin receptor agonist melanotan-II, predicts diet-induced obesity in rats

    NARCIS (Netherlands)

    van Dijk, G; de Vries, K; Nyakas, C; Buwalda, B; Adage, T; Kuipers, F; Kas, M.J.H.; Adan, RAH; Wilkinson, CW; Thiele, TE; Scheurink, AJW

    2005-01-01

    Leptin gains access to the central nervous system where it influences activity of neuronal networks involved in ingestive behavior, neuroendocrine activity, and metabolism. In particular, the brain melanocortin (MC) system is important in leptin signaling and maintenance of energy balance. Although

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

    Directory of Open Access Journals (Sweden)

    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.

  5. Behavioral, hormonal and central serotonin modulating effects of injected leptin.

    Science.gov (United States)

    Haleem, Darakhshan J; Haque, Zeba; Inam, Qurrat-ul-Aen; Ikram, Huma; Haleem, Muhammad Abdul

    2015-12-01

    Leptin is viewed as an important target for developing novel therapeutics for obesity, depression/anxiety and cognitive dysfunctions. The present study therefore concerns behavioral, hormonal and central serotonin modulating effects of systemically injected leptin. Pharmacological doses (100 and 500 μg/kg) of leptin injected systemically decreased 24h cumulative food intake and body weight in freely feeding rats and improved acquisition and retention of memory in Morris water maze test. Potential anxiety reducing, hormonal and serotonin modulating effects of the peptide hormone were determined in a separate experiment. Animals injected with 100 or 500 μg/kg leptin were tested for anxiety in an elevated plus maze test 1h later. A significant increase in the number of entries and time passed in open arm of the elevated plus maze in leptin injected animals suggested pronounced anxiety reducing effect. Moreover, circulating levels of leptin correlated significantly with anxiety reducing effects of the peptide hormone. Serum serotonin increased and ghrelin decreased in leptin injected animals and correlated, positively and negatively respectively, with circulating leptin. Corticosterone increased at low dose and levels were normal at higher dose. Serotonin metabolism in the hypothalamus and hippocampus decreased only at higher dose of leptin. The results support a role of leptin in the treatment of obesity, anxiety and cognitive dysfunctions. It is suggested that hormonal and serotonin modulating effects of leptin can alter treatment efficacy in particularly comorbid conditions. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Benefits of leptin therapy in HIV patients

    Directory of Open Access Journals (Sweden)

    Uma Sinha

    2012-01-01

    Full Text Available Leptin therapy in human recombinant form has recently been used in HIV-associated lipodystrophy syndrome on experimental basis in some small short-term clinical trials. It has shown its beneficial effects only in hypoleptinemic HIV-infected patients by causing definite improvement in their insulin sensitivity, glucose tolerance, lipid status, and truncal obesity. Leptin prevents lipotoxicity and activates insulin signaling pathways through several postulated mechanisms. Central leptin insufficiency with peripheral hyperleptinemia has come out to be a significant contributor to the development of obesity and metabolic syndrome. In this article, we will review the basis of leptin therapy in HIV patients, with its promises. However, further larger clinical trials are needed to prove its long-term efficacy in the control of metabolic complications related to HIV therapy.

  7. Retinol binding protein 4, obesity, and insulin resistance in adolescents

    Directory of Open Access Journals (Sweden)

    Ronaldi Noor

    2017-02-01

    Full Text Available Background Obesity is a global problem. Even in poor and developing countries, obesity has reached alarming levels. In childhood, obesity may lead to insulin resistance. Retinol binding protein (RBP4, secreted primarily by liver and adipose tissues, was recently proposed as a link between obesity and insulin resistance. The role of RBP4 in pediatric obesity and its relationship with insulin resistance have not been well elucidated. Objective To compare RBP4 levels in obese and lean adolescents and to assess for a relationship between RBP4 levels and insulin resistance. Method This cross-sectional study was conducted in three senior high schools in Padang, West Sumatera, Indonesia. Subjects were adolescents aged 14-18 years, who were obese or normal weight (n=56. We measured subjects’ body mass index (BMI and serum RBP4 concentrations. Insulin resistance was assessed using the homeostasis model assessment of insulin resistance (HOMA-IR index. Results Similar RBP4 levels were found in the obese and normoweight groups (P>0.05. Higher RBP4 levels were found in the insulin resistant compared to the non-insulin resistant group, but the difference was not significant (P > 0.05. Conclusion There is no significant difference in mean RBP4 levels in obese adolescents compared to normoweight adolescents. Nor are mean RBP4 levels significantly different between obese adolescents with and without insulin resistance.

  8. Association between systemic leptin and neurotensin concentration in adult individuals with and without type 2 diabetes mellitus.

    Science.gov (United States)

    Barchetta, I; Ciccarelli, G; Cimini, F A; Ceccarelli, V; Orho-Melander, M; Melander, O; Cavallo, M G

    2018-02-07

    Leptin is an adipokine which regulates appetite and energy balance through a mechanism partially mediated by neurotensin (NT) in central nervous system. Besides acting as a neurotransmitter, NT is expressed in human intestine where it promotes fat absorption and its circulating levels associate with obesity, type 2 diabetes mellitus (T2DM) and cardiovascular disease. Whether a relation exists between circulating leptin and NT levels has not been investigated yet. The aim of this study was to test the hypothesis of an association between plasma leptin and NT concentration in adults with or without T2DM. We recruited a population of 72 subjects (M/F: 39/33; age: 49.5 ± 10.6 years; BMI: 26.5 ± 4.7 kg/m 2 ) including individuals with T2DM (n = 32) referring to our Diabetes Outpatient Clinics, Sapienza University of Rome, and healthy controls. Study participants underwent metabolic characterization; plasma leptin was measured by MILLIPLEX, Luminex, and proneurotensin (proNT), a stable precursor of NT, by chemiluminometric sandwich immunoassay. Circulating median (25°-75°) leptin levels were 2.75 (1.27-4.93) ng/mL and did not differ between T2DM and non-diabetic subjects. Leptin concentration directly correlated with proNT (r = 0.41; p = 0.015); higher leptin levels were also associated with age, male gender, obesity, higher HOMA-IR, systolic blood pressure and C-reactive protein. Belonging to the highest pro-NT quartile correlated with greater leptin levels independent of age, gender and other confounders (r 2  = 0.82, p = 0.02). Circulating leptin is associated with higher proNT levels independent of diabetes, obesity and metabolic syndrome components; besides its effects on central leptin signaling, NT may influence energy balance by modulating circulating leptin concentration likely through a mechanism involving gut fat absorption.

  9. Influence of age on leptin induced skeletal muscle signaling

    DEFF Research Database (Denmark)

    Guadalupe Grau, Amelia; Larsen, Steen; Guerra, Borja

    2014-01-01

    Age associated fat mass accumulation could be due to dysregulation of leptin signaling in skeletal muscle. Thus, we investigated total protein expression and phosphorylation levels of the long isoform of the leptin receptor (OB-Rb), and leptin signaling through Janus Kinase 2 (JAK2)/signal...... skeletal muscle of different age....

  10. Vascular endothelial growth factor receptor-2 couples cyclo-oxygenase-2 with pro-angiogenic actions of leptin on human endothelial cells.

    Directory of Open Access Journals (Sweden)

    Elena Garonna

    2011-04-01

    Full Text Available The adipocyte-derived hormone leptin influences the behaviour of a wide range of cell types and is now recognised as a pro-angiogenic and pro-inflammatory factor. In the vasculature, these effects are mediated in part through its direct leptin receptor (ObRb-driven actions on endothelial cells (ECs but the mechanisms responsible for these activities have not been established. In this study we sought to more fully define the molecular links between inflammatory and angiogenic responses of leptin-stimulated human ECs.Immunoblotting studies showed that leptin increased cyclo-oxygenase-2 (COX-2 expression (but not COX-1 in cultured human umbilical vein ECs (HUVEC through pathways that depend upon activation of both p38 mitogen-activated protein kinase (p38(MAPK and Akt, and stimulated rapid phosphorylation of vascular endothelial growth factor receptor 2 (VEGFR2 on Tyr(1175. Phosphorylation of VEGFR2, p38(MAPK and Akt, and COX-2 induction in cells challenged with leptin were blocked by a specific leptin peptide receptor antagonist. Pharmacological inhibitors of COX-2, the phosphatidylinositol 3-kinase (PI3K/Akt pathway and p38(MAPK abrogated leptin-induced EC proliferation (assessed by quantifying 5-bromo-2'-deoxyuridine incorporation, calcein fluorescence and propidium iodide staining, slowed the increased migration rate of leptin-stimulated cells (in vitro wound healing assay and inhibited leptin-induced capillary-like tube formation by HUVEC on Matrigel. Inhibition of VEGFR2 tyrosine kinase activity reduced leptin-stimulated p38(MAPK and Akt activation, COX-2 induction, and pro-angiogenic EC responses, and blockade of VEGFR2 or COX-2 activities abolished leptin-driven neo-angiogenesis in a chick chorioallantoic membrane vascularisation assay in vivo.We conclude that a functional endothelial p38(MAPK/Akt/COX-2 signalling axis is required for leptin's pro-angiogenic actions and that this is regulated upstream by ObRb-dependent activation of VEGFR2

  11. Excess of methyl donor in the perinatal period reduces postnatal leptin secretion in rat and interacts with the effect of protein content in diet.

    Directory of Open Access Journals (Sweden)

    Fanny Giudicelli

    Full Text Available Methionine, folic acid, betaine and choline interact in the one-carbon metabolism which provides methyl groups for methylation reactions. An optimal intake of these nutrients during pregnancy is required for successful completion of fetal development and evidence is growing that they could be involved in metabolic long-term programming. However, the biological pathways involved in the action of these nutrients are still poorly known. This study investigated the interaction between methyl donors and protein content in maternal diet during the preconceptual, pregnancy and lactation periods and the consequences on the rat offspring in the short and long term. Methyl donor supplementation reduced leptin secretion in offspring, whereas insulin levels were mostly affected by protein restriction. The joint effect of protein restriction and methyl donor excess strongly impaired postnatal growth in both gender and long term weight gain in male offspring only, without affecting food intake. In addition, rats born from protein restricted and methyl donor supplemented dams gained less weight when fed a hypercaloric diet. Methylation of the leptin gene promoter in adipose tissue was increased in methyl donor supplemented groups but not affected by protein restriction only. These results suggest that maternal methyl donor supplementation may influence energy homeostasis in a gender-dependent manner, without affecting food intake. Moreover, we showed that macronutrients and micronutrients in maternal diet interact to influence the programming of the offspring.

  12. Leptin promoter variant G2548A is associated with serum leptin and ...

    Indian Academy of Sciences (India)

    Leptin is a protein hormone synthesized by adipocytes and is involved in the regulation of food intake and energy expenditure. We hypothesized that any change in the promoter sequence can affect the expression of the gene and hence leptin protein levels in the serum. The aim of the current study was to investigate the ...

  13. Plasma cholesteryl ester transfer protein mass and phospholipid transfer protein activity are associated with leptin in type 2 diabetes mellitus

    NARCIS (Netherlands)

    Dullaart, R. P. F.; de Vries, R.; Dallinga-Thie, G. M.; van Tol, A.; Sluiter, W. J.

    Adipose tissue contributes to plasma levels of lipid transfer proteins and is also the major source of plasma adipokines. We hypothesized that plasma cholesteryl ester transfer protein (CETP) mass, phospholipid transfer protein (PLTP) activity and cholesteryl ester transfer (CET, a measure of CETP

  14. Short-term effects of a hypocaloric diet with low glycemic index and low glycemic load on body adiposity, metabolic variables, ghrelin, leptin, and pregnancy rate in overweight and obese infertile women: a randomized controlled trial.

    Science.gov (United States)

    Becker, Geórgia F; Passos, Eduardo P; Moulin, Cileide C

    2015-12-01

    Obesity is related to hormonal disorders that affect the reproductive system. Low-glycemic index (LGI) diets seem to exert a positive effect on weight loss and on metabolic changes that result from obesity. We investigated the effects of a hypocaloric diet with an LGI and low glycemic load on anthropometric and metabolic variables, ghrelin and leptin concentrations, and the pregnancy rate in overweight and obese infertile women who were undergoing in vitro fertilization (IVF). The study was a randomized block-design controlled trial in which we analyzed 26 overweight or obese infertile women. Patients were assigned to a hypocaloric LGI-diet group or a control group and followed the protocol for 12 wk. Body weight, body mass index (BMI), percentage of body fat, glucose, insulin, homeostasis model assessment of insulin resistance, serum lipids, reproductive hormones, leptin, acylated ghrelin, number of oocytes retrieved in the IVF cycle, and pregnancy rate were determined. There were greater reductions in body mass, BMI, percentage of body fat, waist:hip ratio, and leptin in the LGI-diet group than in the control group (P diet group had 85.4% more oocytes retrieved than did the control group (7.75 ± 1.44 and 4.18 ± 0.87, respectively; P = 0.039) in the IVF cycle. Three patients (21.4%) in the LGI group experienced a spontaneous pregnancy during the follow-up, which generated 3 live births. The hypocaloric LGI diet promoted a decrease in BMI, percentage of body fat, and leptin concentrations, which improved oocyte development and pregnancy rate. These results support the clinical recommendation to advise overweight and obese women to lose weight through a balanced diet before being submitted for treatment with assisted reproduction technologies. A hypocaloric diet combined with LGI foods seems to be beneficial for these patients, but additional studies are required before this treatment is recommended. This trial was registered at clinicaltrials.gov as NCT02416960

  15. Serum leptin levels in female patients with niddm

    International Nuclear Information System (INIS)

    Haque, Z.; Rahman, M.A.

    2003-01-01

    Objective: To compare serum leptin levels of diabetic and non-diabetic female subjects and also assess the relationship of hyperglycemia with serum insulin, C-peptide and leptin levels. Results: Serum leptin levels of obese diabetic and non-diabetic subjects were significantly higher as compared with lean diabetic patients and non-diabetic subjects (P<0.05). Leptin levels were positively correlated with serum insulin and C-peptide levels. Serum leptin increased with increase in body mass index and waist hip ratio was strongly related with insulin resistance in NIDDM. Conclusion: Leptin levels are increased in obesity and may play a role in development of insulin resistance and NIDDM. (author)

  16. Adipocyte iron regulates leptin and food intake.

    Science.gov (United States)

    Gao, Yan; Li, Zhonggang; Gabrielsen, J Scott; Simcox, Judith A; Lee, Soh-hyun; Jones, Deborah; Cooksey, Bob; Stoddard, Gregory; Cefalu, William T; McClain, Donald A

    2015-09-01

    Dietary iron supplementation is associated with increased appetite. Here, we investigated the effect of iron on the hormone leptin, which regulates food intake and energy homeostasis. Serum ferritin was negatively associated with serum leptin in a cohort of patients with metabolic syndrome. Moreover, the same inverse correlation was observed in mice fed a high-iron diet. Adipocyte-specific loss of the iron exporter ferroportin resulted in iron loading and decreased leptin, while decreased levels of hepcidin in a murine hereditary hemochromatosis (HH) model increased adipocyte ferroportin expression, decreased adipocyte iron, and increased leptin. Treatment of 3T3-L1 adipocytes with iron decreased leptin mRNA in a dose-dependent manner. We found that iron negatively regulates leptin transcription via cAMP-responsive element binding protein activation (CREB activation) and identified 2 potential CREB-binding sites in the mouse leptin promoter region. Mutation of both sites completely blocked the effect of iron on promoter activity. ChIP analysis revealed that binding of phosphorylated CREB is enriched at these two sites in iron-treated 3T3-L1 adipocytes compared with untreated cells. Consistent with the changes in leptin, dietary iron content was also directly related to food intake, independently of weight. These findings indicate that levels of dietary iron play an important role in regulation of appetite and metabolism through CREB-dependent modulation of leptin expression.

  17. Association of surfactant protein-d with obesity

    International Nuclear Information System (INIS)

    Jawed, S.

    2016-01-01

    Obesity is associated with inflammatory diseases and obese individual's poses high risk for infections. Surfactant protein D (SP-D) is an important regulator of immunity and inflammation. Latest studies have suggested that it is also involved in lipid homeostasis and obese subjects have decrease concentration of SPD as compared to normal weight peoples. The aim of the current study was to elucidate the relationship among serum SP-D and BMI. Method: This cross sectional study was performed at Dow University of health sciences (DUHS), Karachi. We analysed 90 obese and non-obese subjects for serum SP-D concentration. SP-D was estimated by ELISA. Data was analysed by SPSS 16. Mean SP-D level and demographical variables between the groups were compared by t test, Associations of SP-D with BMI investigated by regression analysis. Results: obese subjects have significant lower levels of Serum SP-D than non-obese and negatively associated with BMI in both genders (p=0.000). Conclusion: This study concluded that obese subjects have lower concentration of SP-D as compare to non-obese and there is an inverse association between the SP-D and BMI. (author)

  18. 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.

  19. Dietary components in the development of leptin resistance.

    Science.gov (United States)

    Vasselli, Joseph R; Scarpace, Philip J; Harris, Ruth B S; Banks, William A

    2013-03-01

    Classically, leptin resistance has been associated with increased body fat and circulating leptin levels, and the condition is believed to contribute to the onset and/or maintenance of obesity. Although a great deal is known about the central nervous system mechanisms mediating leptin resistance, considerably less is known about the role of diet in establishing and maintaining this altered hormonal state. An exciting new finding has recently been published demonstrating the existence of leptin resistance in normal-weight rats with lean leptin levels by feeding them a high-concentration-fructose diet. This finding has opened the possibility that specific macronutrients may be capable of inducing leptin resistance, independently of the amount of body fat or circulating leptin present in the treated animals. This review describes several lines of research that have recently emerged indicating that specific types of dietary sugars and fats are capable of inducing leptin resistance in experimental rodent models. The results further show that diet-induced leptin resistance is capable of increasing energy intake and elevating body weight gain under appropriate dietary challenges. It appears that biological mechanisms on multiple levels may underlie the dietary induction of leptin resistance, including alterations in the leptin blood-to-brain transport system, in peripheral glucose metabolism, and in central leptin receptor signaling pathways. What is clear from the findings reviewed here is that diet-induced leptin resistance can occur in the absence of elevated circulating leptin levels and body weight, rendering it a potential cause and/or predisposing factor to excess body weight gain and obesity.

  20. Dietary Components in the Development of Leptin Resistance123

    Science.gov (United States)

    Vasselli, Joseph R.; Scarpace, Philip J.; Harris, Ruth B. S.; Banks, William A.

    2013-01-01

    Classically, leptin resistance has been associated with increased body fat and circulating leptin levels, and the condition is believed to contribute to the onset and/or maintenance of obesity. Although a great deal is known about the central nervous system mechanisms mediating leptin resistance, considerably less is known about the role of diet in establishing and maintaining this altered hormonal state. An exciting new finding has recently been published demonstrating the existence of leptin resistance in normal-weight rats with lean leptin levels by feeding them a high-concentration-fructose diet. This finding has opened the possibility that specific macronutrients may be capable of inducing leptin resistance, independently of the amount of body fat or circulating leptin present in the treated animals. This review describes several lines of research that have recently emerged indicating that specific types of dietary sugars and fats are capable of inducing leptin resistance in experimental rodent models. The results further show that diet-induced leptin resistance is capable of increasing energy intake and elevating body weight gain under appropriate dietary challenges. It appears that biological mechanisms on multiple levels may underlie the dietary induction of leptin resistance, including alterations in the leptin blood-to-brain transport system, in peripheral glucose metabolism, and in central leptin receptor signaling pathways. What is clear from the findings reviewed here is that diet-induced leptin resistance can occur in the absence of elevated circulating leptin levels and body weight, rendering it a potential cause and/or predisposing factor to excess body weight gain and obesity. PMID:23493533

  1. Leptin and its cardiovascular effects: Focus on angiogenesis

    Directory of Open Access Journals (Sweden)

    Zoya Tahergorabi

    2015-01-01

    Full Text Available Leptin is an endocrine hormone synthesized by adipocytes. It plays a key role in the energy homeostasis in central and peripheral tissues and has additional roles are attributed to it, such as the regulation of reproduction, immune function, bone homeostasis, and angiogenesis. The plasma concentration of leptin significantly increases in obese individuals. In the present review, we give an introduction concerning leptin, its receptors, signaling pathways, and its effect on cardiovascular system, especially on angiogenesis.

  2. [Leptin and the feedback regulation of body weight].

    Science.gov (United States)

    Wang, X; Ye, G; Sun, J

    1999-09-30

    Body weight may be controlled by a negative feedback loop. Recent studies have identified that the ob gene product, leptin, apparently and exclusively expressed in adipose tissue, is a part of the negative feedback loop. Leptin is proposed to act as an afferent signal in the negative feedback loop to hypothalamus that limiting food-intake, controlling energy homeostasis and regulating the mass of adipose tissue. The dificiency of or resistance to leptin causes severe obesity.

  3. Leptin, adiponectin and pulmonary diseases.

    Science.gov (United States)

    Ali Assad, Nour; Sood, Akshay

    2012-10-01

    Adipose tissue produces leptin and adiponectin - energy-regulating adipokines that may also play a role in inflammatory pulmonary conditions, as suggested by some murine studies. Leptin and adiponectin and their respective receptors are expressed in the human lung. The association between systemic or airway leptin and asthma in humans is currently controversial, particularly among adults. The majority of the evidence among children however suggests that systemic leptin may be associated with greater asthma prevalence and severity, particularly among prepubertal boys and peripubertal/postpubertal girls. Systemic and airway leptin concentrations may also be disproportionately higher in chronic obstructive pulmonary disease (COPD) patients, particularly among women, and reflect greater airway inflammation and disease severity. Quite like leptin, the association between systemic and airway adiponectin and asthma in humans is also controversial. Some but not all studies, demonstrate that serum adiponectin concentrations are protective against asthma among premenopausal women and peripubertal girls. On the other hand, serum adiponectin concentrations are inversely associated with asthma severity among boys but positively associated among men. Further, systemic and airway adiponectin concentrations are higher in COPD patients than controls, as demonstrated by case-control studies of men. Systemic adiponectin is also positively associated with lung function in healthy adults but inversely associated with lung function in subjects with COPD. It is therefore possible that pro-inflammatory effects of adiponectin dominate under certain physiologic conditions and anti-inflammatory effects under others. The adipokine-lung disease literature has critical gaps that include a lack of adequately powered longitudinal or weight-intervention studies; inadequate adjustment for confounding effect of obesity; and unclear understanding of potential sex interactions. It is also uncertain

  4. Remodeling of energy metabolism and absence of electrophysiological changes in hearts of obese hyperleptinemic mice. New insights into the pleiotropic role of leptin

    Directory of Open Access Journals (Sweden)

    Rocío eGuzmán-Ruiz

    2013-11-01

    Full Text Available Dietary treatment with high-fat diets (HFD triggers diabetes and hyperleptinemia, concomitantly with a partial state of leptin resistance that affects hepatic and adipose tissue but not the heart. In this context, characterized by widespread steatosis, cardiac lipid content remains unchanged. As previously reported, HFD-evoked hyperleptinemia could be a pivotal element contributing to increase fatty acid (FA metabolism in the heart and to to prevent cardiac steatosis. This metabolic adaptation might theoretically reduce energy efficiency in cardiomyocytes and lead to cardiac electrophysiological remodeling. Therefore the aim of the current study has been to investigate the impact of long-term HFD on cardiac metabolism and electrophysiological properties of the principal ionic currents responsible of the action potential duration in mouse cardiomyocytes. Male C57BL/6J mice were fed a control (10% kcal from fat or HFD (45% kcal from fat during 32 weeks. Quantification of enzymatic activities regulating mitochondrial uptake of pyruvate and FA showed an increase of both carnitine-palmitoyltransferase and citrate synthase activities together with a decrease of lactate dehydrogenase and pyruvate dehydrogenase activities. Increased expression of uncoupling protein-3, Mn- and Cu/Zn-superoxide dismutases and catalase were also detected. Total glutathione/oxidized glutathione ratios were unaffected by HFD. These data suggest that HFD triggers adaptive mechanisms aimed at i facilitating FA catabolism, and ii preventing oxidative stress. All these changes did not affect the duration of action potentials in cardiomyocytes and only slightly modified electrocardiographic parameters.

  5. Leptin, adiponectin, leptin to adiponectin ratio and insulin resistance in depressive women.

    Science.gov (United States)

    Zeman, Miroslav; Jirak, Roman; Jachymova, Marie; Vecka, Marek; Tvrzicka, Eva; Zak, Ales

    2009-01-01

    Depressive disorder (DD) is associated with an increased risk of type 2 diabetes mellitus (DM2) and cardiovascular disease (CVD). It was suggested, that metabolic syndrome (MetS), cluster of metabolic and hormonal changes, such as insulin resistence (IR), abdominal obesity, dyslipidemia, arterial hypertension and elevated fasting glycaemia, could stand behind the connection. Recent findings have shown, that adipocytokines leptin and adiponectin might play a role in both depression and MetS. The aim of this pilot study was to observe the plasma concentrations of leptin, adiponectin, leptin-to-adiponectin ratio and indices of IR in women with depressive disorder. The plasma leptin, adiponectin, parameters of lipid and glucose homeostasis and indices of IR were investigated in a group of 38 women with DD. The results were compared with those of 38 healthy women of the control group, matched for age. Depressive women differed significantly from the controls in higher concentrations of plasma leptin (p DM2 or CVD.

  6. Obesity, adipokines, and lung disease.

    Science.gov (United States)

    Sood, Akshay

    2010-03-01

    This review summarizes the state of the current literature relating to the associations of lung disease on obesity and adipokines (proteins produced by adipose tissue) in humans. Obesity is an independent risk factor for asthma. Recent studies suggest that obesity is also an independent risk factor for chronic airflow obstruction, as is seen with chronic obstructive pulmonary disease (COPD). The mechanistic basis for these associations in humans is not established, although a possible role for adipokines has been invoked. Leptin, a proinflammatory adipokine, and adiponectin, an anti-inflammatory adipokine, are causally associated with asthma in mice. Although human studies are currently inconclusive, high-serum leptin and low-serum adiponectin concentrations predict asthma, independent of obesity, in select population groups, such as premenopausal women in the United States. In contradistinction, low-serum leptin and high-serum adiponectin concentrations are associated with stable COPD, although these associations are likely confounded by fat mass. Interestingly, leptin may promote systemic and airway inflammation in stable COPD patients. On the other hand, COPD may upregulate systemic and lung adiponectin expression. The precise mechanism and significance of the associations between these adipokines and lung disease at the current stage is confusing and frankly paradoxical in places. This area of research needs additional study that may open up novel therapeutic strategies for these lung diseases.

  7. 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...

  8. Role of leptin in the pathogenesis of breast cancer

    Directory of Open Access Journals (Sweden)

    Thayse Fachin Cormanique

    2015-12-01

    Full Text Available Leptin is a small polypeptide codified by the Obese Gene (OB, deeply related with the body fat mass and energetic balance. Due to its diverse biological effects and downstream signal transducers, multiple classifications have been attributed to leptin, as hormone, cytokine, adypokine, growth factor, and developmental factor, among others. This scenario gives us an idea of the size of the potential biological effects generated by this molecule. The concentration of leptin in the body is determined by the amount of adipose tissue; therefore, hyperleptinemia is a common finding in obese individuals. In addition, high levels of circulating leptin may confer a poor prognosis for any pathological condition. Although leptin history has been reported for more than 20 years, its relationship with cancer has gained notoriety in the past ten years, where studies focused on discussing the issue of obesity as a strong risk factor for cancer developing. Further, growing evidences have pointed leptin as a pivotal mediator of immune response, which aggravates the scenario of cancer occurrence in the presence of obesity. Therefore, leptin can present at least two faces in the pathogenesis of breast cancer, acting by immune and non-immune mechanisms. In this paper we review the dynamic of the leptin axis in breast cancer and further discuss its role in disease, immunopathogenesis and prognosis.

  9. Mexico City normal weight children exposed to high concentrations of ambient PM2.5 show high blood leptin and endothelin-1, vitamin D deficiency, and food reward hormone dysregulation versus low pollution controls. Relevance for obesity and Alzheimer disease.

    Science.gov (United States)

    Calderón-Garcidueñas, Lilian; Franco-Lira, Maricela; D'Angiulli, Amedeo; Rodríguez-Díaz, Joel; Blaurock-Busch, Eleonore; Busch, Yvette; Chao, Chih-kai; Thompson, Charles; Mukherjee, Partha S; Torres-Jardón, Ricardo; Perry, George

    2015-07-01

    Millions of Mexico, US and across the world children are overweight and obese. Exposure to fossil-fuel combustion sources increases the risk for obesity and diabetes, while long-term exposure to fine particulate matter (PM2.5) and ozone (O3) above US EPA standards is associated with increased risk of Alzheimer's disease (AD). Mexico City Metropolitan Area children are chronically exposed to PM2.5 and O3 concentrations above the standards and exhibit systemic, brain and intrathecal inflammation, cognitive deficits, and Alzheimer disease neuropathology. We investigated adipokines, food reward hormones, endothelial dysfunction, vitamin D and apolipoprotein E (APOE) relationships in 80 healthy, normal weight 11.1±3.2 year olds matched by age, gender, BMI and SES, low (n: 26) versus high (n:54) PM2.5 exposures. Mexico City children had higher leptin and endothelin-1 (pMexico City APOE 4 versus 3 children had higher glucose (p=0.009). Serum 25-hydroxyvitamin DMexico City children. Leptin is strongly positively associated to PM 2.5 cumulative exposures. Residing in a high PM2.5 and O3 environment is associated with 12h fasting hyperleptinemia, altered appetite-regulating peptides, vitamin D deficiency, and increases in ET-1 in clinically healthy children. These changes could signal the future trajectory of urban children towards the development of insulin resistance, obesity, type II diabetes, premature cardiovascular disease, addiction-like behavior, cognitive impairment and Alzheimer's disease. Increased efforts should be made to decrease pediatric PM2.5 exposures, to deliver health interventions prior to the development of obesity and to identify and mitigate environmental factors influencing obesity and Alzheimer disease. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Novel Molecular Aspects of Ghrelin and Leptin in the Control of Adipobiology and the Cardiovascular System

    Science.gov (United States)

    Rodríguez, Amaia

    2014-01-01

    Ghrelin and leptin show opposite effects on energy balance. Ghrelin constitutes a gut hormone that is secreted to the bloodstream in two major forms, acylated and desacyl ghrelin. The isoforms of ghrelin not only promote adiposity by the activation of hypothalamic orexigenic neurons but also directly stimulate the expression of several fat storage-related proteins in adipocytes, including ACC, FAS, LPL and perilipin, thereby stimulating intracytoplasmic lipid accumulation. Moreover, both acylated and desacyl ghrelin reduce TNF-α-induced apoptosis and autophagy in adipocytes, suggesting an anti-inflammatory role of ghrelin in human adipose tissue. On the other hand, leptin is an adipokine with lipolytic effects. In this sense, leptin modulates via PI3K/Akt/mTOR the expression of aquaglyceroporins such as AQP3 and AQP7 that facilitate glycerol efflux from adipocytes in response to the lipolytic stimuli via its translocation from the cytosolic fraction (AQP3) or lipid droplets (AQP7) to the plasma membrane. Ghrelin and leptin also participate in the homeostasis of the cardiovascular system. Ghrelin operates as a cardioprotective factor with increased circulating acylated ghrelin concentrations in patients with left ventricular hypertrophy (LVH) causally related to LV remodeling during the progression to LVH. Additionally, leptin induces vasodilation by inducible NO synthase expression (iNOS) in the vascular wall. In this sense, leptin inhibits the angiotensin II-induced Ca2+ increase, contraction and proliferation of VSMC through NO-dependent mechanisms. Together, dysregulation of circulating ghrelin isoforms and leptin resistance associated to obesity, type 2 diabetes, or the metabolic syndrome contribute to cardiometabolic derangements observed in these pathologies. PMID:24685565

  11. Role of leptin on the expression of low density lipoprotein receptor

    Directory of Open Access Journals (Sweden)

    Naval Kishor Yadav

    2014-01-01

    Full Text Available Background & objectives: Leptin resistance oriented hyperleptinaemia is a common problem in obese subjects in association with hypercholesterolaemia. The most common target for hypercholesterolaemia is impaired low density lipoprotein receptor (LDLR. This study was carried out to investigate whether any alteration in LDLR expression could explain the occurrence of hypercholesterolaemia in the event of hyperleptinaemia. Methods: Expression of LDLR and SREBP2 (sterol regulatory element binding protein 2 were examined in HepG2 cells by RT-PCR and Western blotting. JAK2 inhibitor II was used to verify the effect of JAK-STAT (Janus Kinase-Signal Transducer and Activator of Transcription pathway (common mediator for cytokine signaling. Co-localization of LDLR and insulin receptor (IR was examined by confocal microscopy. Results: Leptin was found to reduce the expression of LDLR and its transcription factor SREBP2. On the other hand, a weak signal for stimulation of LDLR by leptin was noted to be mediated by JAK2 pathway. But the joint effect of the two signaling pathways kept LDLR only in depressed mode in presence of leptin. Confocal microscopy showed that LDLR made an intensively co-localized complex with insulin receptor in presence of leptin. Interpretation & conclusions: Our results show that though leptin stimulates LDLR expression very weakly through JAK-STAT signaling pathway, it mainly imposes inhibition on LDLR expression by inhibiting transcription factor SREBP2. The inter-association between LDLR and IR may be a reason to render LDLR functionally inactive in presence of leptin.

  12. Analysis of the variation levels of APN, insulin, sensitive C-reactive protein and leptin in the serum of patients with type 2 diabetes mellitus

    International Nuclear Information System (INIS)

    Du Tongxing; Wang Zizheng; Wang Shukui; Qi Shaokang; Tao Xiaojun

    2005-01-01

    To study the mechanism of pancreatic 13 cell dysfunction and tissue resistance to insulin, and to provide basis for early diagnosis and therapy of the disease, the levels of APN, insulin, sensitive C-reactive protein and leptin in the serum of patients with type 2 diabetes mellitus were determined. Altogether 184 untreatea type 2 diabetes mellitus patients, 30 normal people as the control group, and another 75 type 2 diabetes mellitus patients who have been treated for a year were enrolled in this study. The serum levels of the above indexes were determined by chemiluminescence immunoassay, enzyme immunoassay and radioimmunoassay. The results showed that there were obvious differences in the levels of insulin, leptin, C-reacting protein and insulin antibody between the normal control group and the group of the untreated type 2 diabetes mellitus patients (P<0.01), especially there was significant difference in the level of APN(P<0. 001). Among the 75 type 2 diabetes meltitus patients who have received a year's treatment, all the indexes except for APN and insulin antibody were decreased statistically, while the APN level was increased significantly (P<0.01) than that before the treatment. The determination of markers of type 2 diabetes mellitus is of great significance for its early diagnosis, therapy, prognosis and mechanism research. (authors)

  13. Pharmacokinetics (PK), Pharmacodynamics (PD) and Integrated PK/PD Modeling of a Novel Long Acting FGF21 Clinical Candidate PF-05231023 in Diet-Induced Obese and Leptin-Deficient Obese Mice

    Science.gov (United States)

    Bernardo, Barbara; Yan, Qingyun; Zhu, Yimin; Brenner, Martin B.; Vage, Chandra; Logan, Alison; Calle, Roberto; Talukdar, Saswata

    2015-01-01

    Pharmacological administration of fibroblast growth factor 21 (FGF21) improves metabolic profile in preclinical species and humans. FGF21 exerts its metabolic effects through formation of beta-klotho (KLB)/FGF receptor 1c FGFR1c complex and subsequent signaling. Data from various in vitro systems demonstrate the intact C- and N-terminus of FGF21 is required for binding with KLB, and interaction with FGFR1c, respectively. However the relative roles of the termini for in vivo pharmacological effects are unclear. Here we report PF-05231023, a long-acting FGF21 analogue which is unique in that the half-life and subcutaneous (SC) bioavailability of the intact C-terminus are significantly different from those of the intact N-terminus (2 vs. 22 hr for half-life and 4~7 vs. ~50% SC bioavailability). Therefore, this molecule serves as a valuable tool to evaluate the relative roles of intact C-terminus vs. N-terminus in in vivo pharmacology studies in preclinical species. We determined the effects of PF-05231023 administration on body weight (BW) loss and glucose reduction during an oral glucose tolerance test (OGTT) following SC and intravenous (IV) administration in diet-induced obese (DIO) and leptin-deficient obese (ob/ob) mice, respectively. Our data show that the intact N-terminus of FGF21 in PF-05231023 appears to be sufficient to drive glucose lowering during OGTT and sustain BW loss in DIOs. Further, PK/PD modeling suggests that while the intact FGF21 C-terminus is not strictly required for glucose lowering during OGTT in ob/ob mice or for BW reduction in DIO mice, the higher potency conferred by intact C-terminus contributes to a rapid initiation of pharmacodynamic effects immediately following dosing. These results provide additional insight into the strategy of developing stabilized versions of FGF21 analogs to harness the full spectrum of its metabolic benefits. PMID:25790234

  14. Dietary Proteins, Developmental Programming, and Potential Implication in Maternal Obesity

    Directory of Open Access Journals (Sweden)

    Alireza Jahan-mihan

    2017-08-01

    Full Text Available Background: Proteins are known mainly based on their metabolic and nutritional functions including protein synthesis and a source of energy. In spite of various physiological properties attributed to proteins, their functions have neither been addressed by assessing quality of proteins nor by nutrition and dietetic practices. Methods: Studies were included if they were randomized animal studies, clinical trials and systematic reviews/meta-analysis published in English language. Results: The effect of maternal diet in general and dietary proteins in particular during development on health of offspring has been well-studied. Protein content as well as source of protein in the diet consumed during pregnancy and lactation influenced the risk of metabolic syndrome characteristics in offspring. Both high and low protein diets showed detrimental effects on health of offspring. Moreover, comparison of maternal casein-based diet with soy protein-based diet showed more favorable effect on body weight, body composition, blood pressure, and glucose metabolism in offspring. However, the role of maternal dietary proteins in developing the risk of metabolic syndrome characteristics in offspring in gestational obesity is still unclear and needs further study. Conclusions: Dietary proteins are determining factors in developmental programming. Both quantity and source of proteins in maternal diet influenced the development of metabolic syndrome characteristics in offspring. However, whether they have the same function in presence of gestational obesity is still unclear and needs further study.

  15. Influence of the metabolic syndrome on leptin and leptin receptor in breast cancer.

    Science.gov (United States)

    Carroll, Paul A; Healy, Laura; Lysaght, Joanne; Boyle, Terry; Reynolds, John V; Kennedy, M John; Pidgeon, Graham; Connolly, Elizabeth M

    2011-08-01

    Obesity and its associated metabolic syndrome (MetS) are recognized risk factors for breast cancer. The molecular basis for this association remains largely unknown. Adipokines, in particular leptin and adiponectin, are thought to form part of the mechanism linking obesity with cancer through their altered expression/production either systemically (endocrine pathway) or locally (paracrine/autocrine pathway). Using quantitative PCR, mRNA expression of adiponectin (AdipoQ) and leptin (Ob) in mammary adipose tissue (MAT), intratumoral leptin and associated ligand receptors (ObR, AdipoR1, and AdipoR2) was examined in 77 patients with complete anthropomorphic and serological data. Expression of Ob in MAT, and ObR in matched tumor tissue was significantly higher in patients with MetS compared to obese only or normal weight cancer patients (P < 0.005). There was no difference in intratumoral leptin adiponectin or its ligand receptors in the same groups. Individual features of MetS correlated with Ob and ObR expression, but not obesity markers (BMI, waist circumference). mRNA expression of leptin (Ob) and ObR, in adipose tissue and matched tumor samples, respectively, appear to be associated with obesity status in breast cancer. Increasing insulin resistance is a predominant feature of this higher Ob/ObR expression observed. These novel data indicate that the MetS may be an amenable risk factor for breast cancer. Copyright © 2011 Wiley-Liss, Inc.

  16. Clinical significance of changes of serum leptin and insulin levels in patients with polycystic ovary syndrome

    International Nuclear Information System (INIS)

    Chen Zhaojun; Zhang Lahong; Gao Ying; Ren Xiaohua

    2007-01-01

    Objective: To explore the relationship between the serum leptin, insulin levels and development of polycystic ovary syndrome (PCOS). Methods: Serum leptin and insulin levels (with RIA) were determined in 34 patients with PCOS and 30 controls. Results: The serum leptin and insulin levels in the 34 PCOS patients were significantly higher than those in controls (P<0. 01), and those in obese patients (n=22) were significantly higher than those in non-obese ones (n=12) too(P<0.01). Conclusion: Changes of serum leptin and insulin levels were closely related to the development of PCOS and leptin might be used as a diagnostic indicator for PCOS. (authors)

  17. Effect of leptin level upon lipid metabolism in climacteric women

    International Nuclear Information System (INIS)

    Peng Lijing; Yan Ruming; Sun Enhua

    2005-01-01

    To observe the relationship between leptin and obesity of climacteric women with their lipid metabolism, 110 cases of climacteric women were chosen as observation group, consisting of 69 cases obese subgroup and 45 cases non-obese group, and 60 cases of normal reproduction- age women were arranged as control group. Blood levels of leptin, INS, LDL-C, TG, HDL-C, apoA1, apoB, LH, FSH, E-2, T, and P were detected and BMI was calculated. The results showed that blood levels of leptin and INS of obese subgroup were significantly higher than those of non-obese sub-group and control group(P<0.01), and that LDL-C(5.01 mmol/L), TG(2.21mmal/L) and apoB(0.89g/L) levels in obese subgroup were significantly higher than those of control group. Furthermore, an important observation was that in climacteric women group, blood leptin level was positively and significantly correlated with insulin, BMI and several atherogenic blood lipid parameters, including LDL-C, TG and apoB. Thus, a preliminary conclusion might be reached as that the high climacteric level of leptin is associated with abnormal lipid metabolism related to atherogenity, and so leptin and lipid metabolism as a whole should be paid more attention in climateric women, especially those with obesity. (authors)

  18. Some metabolic and anthropometric variables in obes children by measuring serum insulin, and leptin

    International Nuclear Information System (INIS)

    Nour Eldin, A.M.

    2004-01-01

    The present study aimed to assess serum leptin level in obese children to study its correlation with some metabolic variables as serum insulin and serum glucose. The study was conducted on 30 obese children of age from 9-14 years with body mass index (BMI) > 27.8 Kg/m 2 . All children were subjected to history taking, clinical examination, anthropometric measurements and laboratory investigations including fasting serum leptin, insulin and blood glucose. Serum leptin was significantly higher in obese children (102.3± 56.2 ng/ml) compared to non-obese ones (48.15±26.1 ng/ml). The relation between serum leptin and anthropometric measurements and laboratory investigations including fasting serum insulin and blood glucose. Serum leptin was significantly higher in obese children (102.3± 56.2 ng/ml)compared to non-obese ones (48.15±26.1 ng/ml). The relation between serum leptin and anthropometric variables was positively correlated with BMI r s = 0.68, (p s = 0.59.(p<0.01). It is concluded that serum leptin is increased in obesity and its concentration effects the size of the body. Moreover, the relation of leptin and insulin suggests a positive role of leptin in insulin resistance, which are common metabolic disorders associated with obesity

  19. Expression and immunohistochemical localization of leptin in human periapical granulomas

    Science.gov (United States)

    Martín-González, Jénifer; Carmona-Fernández, Antonio; Pérez-Pérez, Antonio; Sánchez-Jiménez, Flora; Sánchez-Margalet, Víctor

    2015-01-01

    Background Leptin, initially described as an adipocyte-derived hormone to regulate weight control, is expressed in normal and inflamed human dental pulp, being up-regulated during pulp experimental inflammation. Leptin receptor (LER) has been identified in human periapical granulomas. The aim of this study was to analyze and characterize the expression of leptin in human periapical granulomas. Material and Methods Fifteen periapical inflammatory lesions were obtained from extracted human teeth and teeth which underwent periapical surgery. After their morphological categorization as periapical granulomas and gradation of the inflammatory infiltrate, they were examined by immunohistochemistry using human leptin policlonal antibodies. Leptin mRNA expression was also determined by quantitative real-time PCR (qRT-PCR) and the amount of leptin protein was analyzed by immunoblot. Results All periapical lesions exhibited the characteristic of chronic granulomatous inflammatory process with inflammatory infiltrate grade III. Leptin+ cells were detected in 13 periapical granulomas (86.6%). The median number of Leptin+ cells in periapical granulomas was 1.70 (0.00-7.4). Amongst the inflammatory cells in the periapical granulomas, only macrophages were reactive to leptin antibodies. Western blot analysis revealed the presence in all samples of a protein with apparent molecular weight of approximately 16 kDa, corresponding to the estimated molecular weights of leptin. The expression of leptin mRNA was confirmed by qRT-PCR analysis and the size of the amplified fragment (296 bp for leptin and 194 bp for cyclophilin) was assessed by agarose gel electrophoresis. Conclusions For the first time, it has been demonstrated that human periapical granuloma expresses the adipokine leptin. Key words: Apical granuloma, dental pulp, endodontics, leptin, leptin receptor, immune system, immunohistochemistry, periapical inflammatory response. PMID:25662559

  20. 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.

  1. C1q/TNF-related protein 6 (CTRP6) links obesity to adipose tissue inflammation and insulin resistance.

    Science.gov (United States)

    Lei, Xia; Seldin, Marcus M; Little, Hannah C; Choy, Nicholas; Klonisch, Thomas; Wong, G William

    2017-09-08

    Obesity is associated with chronic low-grade inflammation, and metabolic regulators linking obesity to inflammation have therefore received much attention. Secreted C1q/TNF-related proteins (CTRPs) are one such group of regulators that regulate glucose and fat metabolism in peripheral tissues and modulate inflammation in adipose tissue. We have previously shown that expression of CTRP6 is up-regulated in leptin-deficient mice and, conversely, down-regulated by the anti-diabetic drug rosiglitazone. Here, we provide evidence for a novel role of CTRP6 in modulating both inflammation and insulin sensitivity. We found that in obese and diabetic humans and mouse models, CTRP6 expression was markedly up-regulated in adipose tissue and that stromal vascular cells, such as macrophages, are a major CTRP6 source. Overexpressing mouse or human CTRP6 impaired glucose disposal in peripheral tissues in response to glucose and insulin challenge in wild-type mice. Conversely, Ctrp6 gene deletion improved insulin action and increased metabolic rate and energy expenditure in diet-induced obese mice. Mechanistically, CTRP6 regulates local inflammation and glucose metabolism by targeting macrophages and adipocytes, respectively. In cultured macrophages, recombinant CTRP6 dose-dependently up-regulated the expression and production of TNF-α. Conversely, CTRP6 deficiency reduced circulating inflammatory cytokines and pro-inflammatory macrophages in adipose tissue. CTRP6-overexpressing mice or CTRP6-treated adipocytes had reduced insulin-stimulated Akt phosphorylation and glucose uptake. In contrast, loss of CTRP6 enhanced insulin-stimulated Akt activation in adipose tissue. Together, these results establish CTRP6 as a novel metabolic/immune regulator linking obesity to adipose tissue inflammation and insulin resistance. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  2. Measurement of serum leptin levels in polycystic ovary syndrome with hyperandrogenemia and its significance

    International Nuclear Information System (INIS)

    Wang Yande; Zhang Zhiping; Lu Gen; Luo Beilei

    2002-01-01

    Objective: To investigate the serum leptin concentration in polycystic ovary syndrome (PCOS) with hyperandrogenemia (HA) and its relationship with testosterone (T) level and body mass index (BMI). Methods: Serum leptin levels were measured by radioimmunoassay in 53 patients with PCOS, in which 36 cases were of the in non-obesity group and 17 cases in obese group. 30 non-obese cases and 20 obese cases without PCOS served as controls. Results: The levels of leptin in PCOS with HA in obese and non-obese group were significantly higher than those in control group (all p < 0.01). There was a positive correlation between serum leptin levels and testosterone levels in both groups (r = 0.51, p < 0.01 and r = 0.58, p < 0.01). No correlation existed between serum leptin levels and body mass index (BMI) in PCOS patients of non-obese group but there was positive correlation in obesity group (r = 0.56, p < 0.01). Conclusion: High serum leptin levels is one of the characteristic in PCOS patients. The HA in PCOS patients is related to serum leptin levels and heavyweight or obese patients have the phenomenon of leptin resistance

  3. Leptin effects on the regenerative capacity of human periodontal cells.

    Science.gov (United States)

    Nokhbehsaim, Marjan; Keser, Sema; Nogueira, Andressa Vilas Boas; Jäger, Andreas; Jepsen, Søren; Cirelli, Joni Augusto; Bourauel, Christoph; Eick, Sigrun; Deschner, James

    2014-01-01

    Obesity is increasing throughout the globe and characterized by excess adipose tissue, which represents a complex endocrine organ. Adipose tissue secrets bioactive molecules called adipokines, which act at endocrine, paracrine, and autocrine levels. Obesity has recently been shown to be associated with periodontitis, a disease characterized by the irreversible destruction of the tooth-supporting tissues, that is, periodontium, and also with compromised periodontal healing. Although the underlying mechanisms for these associations are not clear yet, increased levels of proinflammatory adipokines, such as leptin, as found in obese individuals, might be a critical pathomechanistic link. The objective of this study was to examine the impact of leptin on the regenerative capacity of human periodontal ligament (PDL) cells and also to study the local leptin production by these cells. Leptin caused a significant downregulation of growth (TGFβ1, and VEGFA) and transcription (RUNX2) factors as well as matrix molecules (collagen, and periostin) and inhibited SMAD signaling under regenerative conditions. Moreover, the local expression of leptin and its full-length receptor was significantly downregulated by inflammatory, microbial, and biomechanical signals. This study demonstrates that the hormone leptin negatively interferes with the regenerative capacity of PDL cells, suggesting leptin as a pathomechanistic link between obesity and compromised periodontal healing.

  4. The importance of leptin in animal science

    Directory of Open Access Journals (Sweden)

    Mirela Ahmadi

    2016-05-01

    Full Text Available There are two different neurons that control the energetic homeostasis in animals: appetite-stimulating and appetite-suppressing neurons. Leptin is a peptide hormone (also known as “satiety hormone”, released by adipose cells, being an anorexigenic compound which inhibit the hunger. Leptin function in animal organism is opposite by the action of ghrelin – a peptide hormone acting as an orexigenic compound that activate the hunger sensation. The quantity of leptin produced in organism is correlated by the size and the number of adipocytes, and of course by the lipid tissue mass. The action of leptin is in accordance with the neuropeptide Y that signaling the brain to increase the appetite and make the animal to eat. When the animals lose weight, the mass of adipose tissue is diminished, that has as consequence a decrease the leptin concentration in the blood. Blood leptin is correlated also with other characteristics, such as: fasting for a short term, stress, physical activity, sleep duration (prehibernation and hibernation, insulin concentration, obesity and diabetes.

  5. Plasma levels of leptin, omentin, collagenous repeat-containing sequence of 26-kDa protein (CORS-26 and adiponectin before and after oral glucose uptake in slim adults

    Directory of Open Access Journals (Sweden)

    Schäffler Andreas

    2007-02-01

    Full Text Available Abstract Background Adipose tissue secreted proteins are collectively named adipocytokines and include leptin, adiponectin, resistin, collagenous repeat-containing sequence of 26-kDa protein (CORS-26 and omentin. Several of these adipocytokines influence insulin sensitivity and glucose metabolism and therefore systemic levels may be affected by oral glucose uptake. Whereas contradictory results have been published for leptin and adiponectin, resistin has not been extensively investigated and no reports on omentin and CORS-26 do exist. Methods Therefore the plasma levels of these proteins before and 120 min after an oral glucose load were analyzed in 20 highly-insulin sensitive, young adults by ELISA or immunoblot. Results Circulating leptin was reduced 2 h after glucose uptake whereas adiponectin and resistin levels are not changed. Distribution of adiponectin and CORS-26 isoforms were similar before and after glucose ingestion. Omentin is highly abundant in plasma and immunoblot analysis revealed no alterations when plasma levels before and 2 h after glucose intake were compared. Conclusion Taken together our data indicate that only leptin is reduced by glucose uptake in insulin-sensitive probands whereas adiponectin and resistin are not altered. CORS-26 was demonstrated for the first time to circulate as high molecular weight form in plasma and like omentin was not influenced by oral glucose load. Omentin was shown to enhance insulin-stimulated glucose uptake but systemic levels are not correlated to postprandial blood glucose.

  6. [CDNA cloning of human leptin and its expression].

    Science.gov (United States)

    Jia, Zhen-Yu; Fu, Xiao-Min; Jin, Ai-Hua; Cao, Jiang

    2003-07-01

    To clone cDNA of human leptin gene and obtain leptin protein for future study on leptin binding proteins. The cDNA of human leptin with 6 x his-tag was cloned by over-hang extension PCR protocol using human genomic DNA as template, and subcloned into in vitro expression vector pIVEX2.3MCS, and the fusion protein was expressed in vitro by Rapid Translation System (RTS) (RTS500 cycle primer Kit and RTS500 ProteoMaster of Roche company). The apparent molecular weight(19.46 kD) and the immuno-specificity of the fusion protein were confirmed by SDS-PAGE and Western blot, and the expressed fusion protein stayed mainly in the supernatant of the reaction mixture in soluble form. This work provides us solid basis for further study on new leptin-associated proteins.

  7. Pharmacokinetics (PK, pharmacodynamics (PD and integrated PK/PD modeling of a novel long acting FGF21 clinical candidate PF-05231023 in diet-induced obese and leptin-deficient obese mice.

    Directory of Open Access Journals (Sweden)

    Yan Weng

    Full Text Available Pharmacological administration of fibroblast growth factor 21 (FGF21 improves metabolic profile in preclinical species and humans. FGF21 exerts its metabolic effects through formation of beta-klotho (KLB/FGF receptor 1c FGFR1c complex and subsequent signaling. Data from various in vitro systems demonstrate the intact C- and N-terminus of FGF21 is required for binding with KLB, and interaction with FGFR1c, respectively. However the relative roles of the termini for in vivo pharmacological effects are unclear. Here we report PF-05231023, a long-acting FGF21 analogue which is unique in that the half-life and subcutaneous (s.c. bioavailability of the intact C-terminus are significantly different from those of the intact N-terminus (2 vs. 22 hr for half-life and 4~7 vs. ~50% SC bioavailability. Therefore, this molecule serves as a valuable tool to evaluate the relative roles of intact C-terminus vs. N-terminus in in vivo pharmacology studies in preclinical species. We determined the effects of PF-05231023 administration on body weight (BW loss and glucose reduction during an oral glucose tolerance test (OGTT following SC and intravenous (i.v. administration in diet-induced obese (DIO and leptin-deficient obese (ob/ob mice, respectively. Our data show that the intact N-terminus of FGF21 in PF-05231023 appears to be sufficient to drive glucose lowering during OGTT and sustain BW loss in DIOs. Further, PK/PD modeling suggests that while the intact FGF21 C-terminus is not strictly required for glucose lowering during OGTT in ob/ob mice or for BW reduction in DIO mice, the higher potency conferred by intact C-terminus contributes to a rapid initiation of pharmacodynamic effects immediately following dosing. These results provide additional insight into the strategy of developing stabilized versions of FGF21 analogs to harness the full spectrum of its metabolic benefits.

  8. Leptin as a Marker of Body Fat and Hyperinsulinemia in College Students

    Science.gov (United States)

    Kempf, Angela M.; Strother, Myra L.; Li, Chaoyang; Kaur, Harsohena; Huang, Terry T-K.

    2006-01-01

    Little is known about obesity and insulin resistance in college students. Leptin is a hormone secreted by fat cells and has been shown to strongly correlate with both obesity and insulin resistance in children and adults. We investigated associations of leptin with insulin secretion and action in 119 normal-weight students aged 18-24 years. Leptin…

  9. Leptin im Knochenstoffwechsel

    Directory of Open Access Journals (Sweden)

    Vock L

    2003-01-01

    Full Text Available Leptin ist ein in Adipozyten exprimiertes Hormon mit vielfältigen Funktionen im gesamten Organismus. Verschiedene Studien legen eine positive Wirkung von Leptin auf den Knochenstoffwechsel nahe. In vitro führte die Inkubation von Knochenmarkstromazellen mit Leptin zu deren Differenzierung zu Osteoblasten und Mineralisation der Matrix. Bei ovarektomierten Ratten konnte durch Leptin der Knochenverlust vermindert werden. Überraschenderweise zeigten andere Studien eine zentrale inhibitorische Wirkung von Leptin auf Osteoblasten bei Nagern. Diese einander scheinbar widersprechenden Ergebnisse zeigen, daß die molekularen Mechanismen, mit welchen Leptin auf den Knochenstoffwechsel wirkt, noch nicht ausreichend verstanden werden. In klinischen Studien findet sich eine protektive Wirkung von Fettmasse und "body mass index" (BMI auf die Knochendichte (postmenopausaler Frauen überwiegend bestätigt. Damit im Einklang, konnten erhöhte Leptinspiegel gefunden werden. Ob Leptin nun direkt in den Knochenstoffwechsel eingreift oder bloß indirekt etwa über eine erhöhte mechanische Belastung, läßt sich aus klinischen Studien allein nicht beantworten. Hingegen dürfte Leptin im Knochenstoffwechsel von Männern keine oder nur eine untergeordnete Rolle spielen. Die Situation bei Kindern und Jugendlichen ist noch unklar, wobei eine positive Wirkung von Leptin in fetalem Knochen relativ sicher ist. Leptin könnte jedoch auch im Wachstum und der Knochenreifung bei Kindern und Jugendlichen eine Rolle spielen.

  10. Leptin levels distribution and ethnic background in two populations from Chile: Caucasian and Mapuche groups.

    Science.gov (United States)

    Pérez-Bravo, F; Albala, C; Santos, J L; Yañez, M; Carrasco, E

    1998-10-01

    Leptin, the product of the human ob gene is increased in obese individuals, suggesting resistance to its effect. We examined the relationship of serum leptin levels with respect to obesity, gender and insulin levels in two populations with different ethnic compositions in Chile. Leptin and insulin levels were determined by radioimmunoassay (RIA) and correlated with body mass index (BMI), gender and ethnic background. 79 Caucasian subjects from Santiago and 65 Mapuche natives from the Araucania region, Chile, were included in this study. Leptin concentrations in obese subjects were significantly increased in both ethnic groups in relation to lean status: Caucasian and Mapuche obese 19.3 +/- 11.6 and 10.1 +/- 5.8 (P Mapuche lean 10.4 +/- 5.8 and 4.7 +/- 2.9 (P Mapuche and Caucasian groups, similar leptin levels were observed among the males of the two populations in both metabolic states (lean and obese). In contrast, the leptin level distributions between women showed a marked difference, having a minor value in the Mapuche women with a comparable value with the male group in this ethnic population. The leptin concentrations are associated with obesity in both ethnic groups in Chile. However, the leptin levels between the Mapuche natives were significantly decreased compared to the Caucasian group. The gender distribution does not seem to be important in the Mapuche natives. The ethnic composition seems to be important in the leptin distribution in the analysed populations.

  11. Drug disposition in obesity and protein-energy malnutrition.

    Science.gov (United States)

    Boullata, Joseph I

    2010-11-01

    Clinical response to medication can differ between patients. Among the known sources of variability is an individual's nutrition status. This review defines some pharmacokinetic terms, provides relevant body size metrics and describes the physiologic influences of protein-energy malnutrition and obesity on drug disposition. Weight-based drug dosing, which presumes a healthy BMI, can be problematic in the protein-energy malnourished or obese patient. The use of total body weight, lean body weight, or an adjusted body weight depends on the drug and how it is differently handled in malnutrition or obesity. Most of the recognized influences are seen in drug distribution and drug elimination as a result of altered body composition and function. Distribution characteristics of each drug are determined by several drug-related factors (e.g. tissue affinity) in combination with body-related factors (e.g. composition). Drug elimination occurs through metabolic and excretory pathways that can also vary with body composition. The current data are limited to select drugs that have been reported in small studies or case reports. In the meantime, a rational approach to evaluate the potential influences of malnutrition and obesity can be used clinically based on available information. Antimicrobials are discussed as a useful example of this approach. Further advancement in this field would require collaboration between experts in body composition and those in drug disposition. Until more data are available, routine monitoring by the clinician of the protein-energy malnourished or obese patient receiving weight-based drug regimens is necessary.

  12. [The importance of leptin in oncology--hypothesis or facts?].

    Science.gov (United States)

    Gaja, A; Churý, Z

    2001-04-01

    Leptin was described as a protein produced mostly by adipocytes which participates in regulation of caloric intake. This protein has further many physiological regulatory functions especially in hematopoesis and reproduction. The role of leptin in diseases is also considered. Maybe leptin is a part of the pathogenic mechanism or its metabolism can be influenced secondary to disease. Malignant tumours are the important area where leptin can acts. This imagination is supported by recent in vitro studies and some clinical observations. It is consider that some parameters of leptin metabolism can serve as usable marker for diagnosis and monitoring of some malignant tumours--especially breast cancer or some types of leukemia. The authors give a review of actual information of leptin metabolism changes in oncological diseases.

  13. The effect of four weeks restricted diet on serum soluble leptin receptor levels and adipocyte leptin receptor density in normoweight rattus norvegicus strain Wistar

    Directory of Open Access Journals (Sweden)

    M. R. Indra

    2006-09-01

    Full Text Available One of the five possible mechanisms of leptin resistance in human obesity is the defect in the leptin receptor (Ob-R. Evidence has accumulated that leptin-binding activity in human serum is related to a soluble form of the leptin receptor, and restriction of energy intake resulted a decrease in circulating leptin levels. Aim of this study is to examine the difference of serum soluble leptin receptor level and leptin receptor density in rat adipose tissue of adventitial aorta after four weeks treated with different restricted diets. Soluble leptin receptor level was measured by ELISA and leptin receptor density by using immuno-histochemistry. The soluble leptin receptor in group treated with 40% of normal daily calori diet was found significantly lower than control (p = 0.02. There were no any significant differences among group treated with 40 % of normal daily calori diet, “1 day fast-1day eat”, and ”1day fast-2 days eat” groups, and among 1 day fast-1 day eat”, ”day fast - 2 days eat” and control groups as well. On the other hand, leptin receptor density in adipose tissues was higher in restricted diet group than control. Diet of 40 % normal daily calorie for 4 weeks decreased soluble leptin receptor level, but increased adipocyte leptin receptor density of the adipose tissue of rat adventitial aorta. These changes may be resulted from an up regulation mechanism in relation with homeostatic maintenance. (Med J Indones 2006; 15:145-50 Keywords: restricted diet, leptin receptor, soluble leptin receptor, adipocyte, obesity

  14. Leptin distribution and metabolism in the pregnant rat: transplacental leptin passage increases in late gestation but is reduced by excess glucocorticoids.

    Science.gov (United States)

    Smith, Jeremy T; Waddell, Brendan J

    2003-07-01

    Leptin is essential for the establishment of pregnancy and appears to promote fetal growth, but the mechanisms regulating fetal leptin exposure remain unclear. In rodents, indirect evidence suggests that fetal leptin is partly derived from the maternal circulation via transplacental passage. Indeed, the placenta expresses mRNA for Ob-Ra, one of the short forms of the leptin receptor (Ob-R(S)) important in leptin transport, and this expression increases markedly in late pregnancy. Therefore, we determined the transplacental passage of maternal leptin to the fetus in the rat and whether this transport increases near term in association with a rise in placental expression of Ob-R(S) protein. Because of the proposed role of leptin in promoting fetal growth, we also assessed the effect of glucocorticoid-induced fetal growth retardation on placental leptin transport. Anesthetized rats received a constant infusion of (125)I-leptin via a jugular cannula before and at d 16 and 22 of pregnancy (term = d 23); plasma samples were obtained at 10, 20, 40, 60, 80, and 100 min, and fetuses and placentas were collected at the time of the final sample. The metabolic clearance rate of leptin fell (P pregnancy. Over this same period, Ob-R(S) protein expression in the placental labyrinth zone increased by almost 2-fold. Transplacental leptin passage was reduced (P pregnancy. Consistent with the proposed role of leptin as a fetal growth factor, transplacental leptin passage is reduced in association with glucocorticoid-induced fetal growth retardation.

  15. Leptin and cancer: Pathogenesis and modulation

    Directory of Open Access Journals (Sweden)

    Deep Dutta

    2012-01-01

    Full Text Available Leptin, a product of Ob gene from adipocytes regulates appetite, energy expenditure and body mass composition by decreasing orexigenic and increasing anorexigenic neuropeptide release from hypothalamus. Research over the past few years have suggested leptin/leptin receptor dysregulation to have a role in the development of a large variety of malignancies like breast ca, thyroid ca, endometrial ca and gastrointestinal malignancies, predominantly through JAK/STAT pathway which modulates PI3K/AKT3 signaling, ERK1/2 signaling, expression of antiapoptotic proteins (like XIAP, systemic inflammation (TNF-α, IL6, angiogenic factors (VEGF and hypoxia inducible factor-1a (HIF-1a expression. In this review, the current understanding of leptin′s role in carcinogenesis has been elaborated. Also a few agents modulating leptin signaling to inhibit cancer cell growth has been described.

  16. Increased leptin expression in common Carp (Cyprinus carpio) after food intake but not after fasting or feeding to satiation

    NARCIS (Netherlands)

    Huising, M.O.; Geven, E.J.W.; Kruiswijk, C.P.; Nabuurs, S.B.; Stolte, E.H.; Spanings, F.A.T.; Verburg-van Kemenade, B.M.L.; Flik, G.

    2006-01-01

    Leptin is a key factor in the regulation of food intake and is an important factor in the pathophysiology of obesity. However, more than a decade after the discovery of leptin in mouse, information regarding leptin in any nonmammalian species is still scant. We report the identification of duplicate

  17. Increased leptin expression in common carp (Cyprinus carpio) after food intake but not after fasting or feeding to satiation

    NARCIS (Netherlands)

    Huising, M.O.; Geven, E.J.; Kruiswijk, C.P.; Nabuurs, S.B.; Stolte, H.H.; Spanings, F.A.; Verburg-van Kemenade, B.M.L.; Flik, G.

    2006-01-01

    Leptin is a key factor in the regulation of food intake and is an important factor in the pathophysiology of obesity. However, more than a decade after the discovery of leptin in mouse, information regarding leptin in any nonmammalian species is still scant. We report the identification of duplicate

  18. Leptin but not Ciliary Neurotrophic Factor (CNTF) induces Phosphotyrosine Phosphatase-1B expression in human neuronal cells (SH-SY5Y): putative explanation of CNTF efficacy in leptin-resistant state

    OpenAIRE

    Benomar, Yacir; Berthou, Flavien; Vacher, Claire-Marie; Bailleux, Virginie; Gertler, Arieh; Djiane, Jean; Taouis, Mohammed

    2009-01-01

    Growing evidences suggest that obesity is associated with hypothalamic leptin resistance, leading to the alteration of food intake control. Alternative treatment using ciliary neurotrophic factor (CNTF) has been suggested because CNTF exerts a leptin-like effect, even in leptin-resistant states, but the mechanisms by which CNTF maintains this effect are not yet understood. Both leptin and CNTF act in the hypothalamus through similar signaling pathways including janus kinase-2/signal transduce...

  19. Leptin Level in Women with Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    Alexander V. Dreval, PhD, ScD

    2013-06-01

    Full Text Available A detailed study of the dynamics of leptin in the various types of disturbances in carbohydrate metabolism could reveal its role in the pathogenesis of Type 2 Diabetes Mellitus (T2DM. The aim of this study was to investigate the Fasting Leptin Level (FLL and effect of acute hyperinsulinemia during the Intravenous Glucose Tolerance Test (IVGTT on the leptin levels in women with Insulin Resistance Syndrome (IRS. Materials and Methods: In total, 59 obese women (54.0 [48.5-60.0] yrs; BMI – 33.2 [29.0-37.2] kg/m² with IRS (12 – obesity (NGT, 18 - ITG and 30 - T2DM were observed. The IVGTT test was done only in women with impaired glucose tolerance (IGT and T2DM. The leptin level was investigated during fasting conditions and again 120 min post glucose loading. Then the Hepatic glucose production Index (H-index was calculated using the IVGTT data. Results: The FLL in women with normal glucose tolerance (NGT was almost two times greater than in women with IGT and T2DM. A negative relationship was found to exist between FLL and HbA1c in T2DM (r=0.3, p8%. The leptin level significantly decreased at 120 min of IVGTT in both the IGT and T2DM groups (p<0.05. Conclusion: The FLL depended upon the degree of glucose metabolism impairment; postprandial leptin response to the glucose load was lower in the IGT group than in the T2DM subjects.

  20. The association between leptin and depressive symptoms is modulated by abdominal adiposity

    Science.gov (United States)

    Milaneschi, Yuri; Sutin, Angelina R; Terracciano, Antonio; Canepa, Marco; Gravenstein, Kristofer S; Egan, Josephine M; Vogelzangs, Nicole; Guralnik, Jack M; Bandinelli, Stefania; Penninx, Brenda WJH; Ferrucci, Luigi

    2014-01-01

    Background Evidence for a role of leptin in depression is limited and conflicting. Inconclusive findings may be explained by the complex effect of obesity on leptin signaling. In particular, both hyperleptinemia due to leptin resistance in obese persons as well as low leptin in lean persons can imply that low leptin biological signaling is associated with an increased risk of significant depressive symptoms. We tested whether the relationship between leptin and depressive symptoms is modulated by abdominal adiposity in two population-based studies. Methods Data were from 851 participants (65–94 years) of the InCHIANTI Study and 1,064 (26–93 years) of the Baltimore Longitudinal Study of Aging (BLSA). Plasma concentrations of leptin, waist circumference and depressive symptoms via the Center for Epidemiological Studies-Depression scale (CES-D) were assessed. In longitudinal InCHIANTI analyses onset of depressed mood (CES-D≥20) was evaluated over a 9-year follow-up. Results In pooled cross-sectional analyses the interaction between leptin and waist circumference was significantly associated with CES-D scores ((log)leptin-by-waist interaction p=0.01). Also in longitudinal analyses, the (log)leptin-by-waist interaction term significantly (p=0.04) predicted depressed mood onset over time; depressed mood risk was especially increased for high levels of both leptin and waist circumference. Conclusions The present findings suggest that low leptin signaling rather than low leptin concentration is a risk factor for depression. Future studies should develop proxy measures of leptin signaling by combining information on abdominal adiposity and leptin level to be used for clinical and research applications. PMID:24636496

  1. Leptin signaling molecular actions and drug target in hepatocellular carcinoma

    Directory of Open Access Journals (Sweden)

    Jiang N

    2014-11-01

    Full Text Available Nan Jiang,1,* Rongtong Sun,2,* Qing Sun3 1Shandong University School of Medicine, Jinan, Shandong Province, People’s Republic of China; 2Weihai Municipal Hospital, Weihai, Shandong Province, People’s Republic of China; 3Department of Pathology, QianFoShan Hospital Affiliated to Shandong University, Jinan, Shandong Province, People’s Republic of China *These authors contributed equally to this work Abstract: Previous reports indicate that over 13 different tumors, including hepatocellular carcinoma (HCC, are related to obesity. Obesity-associated inflammatory, metabolic, and endocrine mediators, as well as the functioning of the gut microbiota, are suspected to contribute to tumorigenesis. In obese people, proinflammatory cytokines/chemokines including tumor necrosis factor-alpha, interleukin (IL-1 and IL-6, insulin and insulin-like growth factors, adipokines, plasminogen activator inhibitor-1, adiponectin, and leptin are found to play crucial roles in the initiation and development of cancer. The cytokines induced by leptin in adipose tissue or tumor cells have been intensely studied. Leptin-induced signaling pathways are critical for biological functions such as adiposity, energy balance, endocrine function, immune reaction, and angiogenesis as well as oncogenesis. Leptin is an activator of cell proliferation and anti-apoptosis in several cell types, and an inducer of cancer stem cells; its critical roles in tumorigenesis are based on its oncogenic, mitogenic, proinflammatory, and pro-angiogenic actions. This review provides an update of the pathological effects of leptin signaling with special emphasis on potential molecular mechanisms and therapeutic targeting, which could potentially be used in future clinical settings. In addition, leptin-induced angiogenic ability and molecular mechanisms in HCC are discussed. The stringent binding affinity of leptin and its receptor Ob-R, as well as the highly upregulated expression of both

  2. Body Mass Influences Cortical Bone Mass Independent of Leptin Signaling

    OpenAIRE

    Iwaniec, U.T.; Dube, M.G.; Boghossian, S.; Song, H.; Helferich, W.G.; Turner, R.T.; Kalra, S.P.

    2008-01-01

    Obesity in humans is associated with increased bone mass. Leptin, a hormone produced by fat cells, functions as a sentinel of energy balance, and may mediate the putative positive effects of body mass on bone. We performed studies in male C57Bl/6 wild type (WT) and leptin-deficient ob/ob mice to determine whether body mass gain induced by high fat intake increases bone mass and, if so, whether this requires central leptin signaling. The relationship between body mass and bone mass and archite...

  3. Leptin as a Potential Regulator of FGF21

    Directory of Open Access Journals (Sweden)

    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.

  4. Piperidine alkaloids from Piperretrofractum Vahl. protect against high-fat diet-induced obesity by regulating lipid metabolism and activating AMP-activated protein kinase

    International Nuclear Information System (INIS)

    Kim, Kyung Jin; Lee, Myoung-Su; Jo, Keunae; Hwang, Jae-Kwan

    2011-01-01

    Highlights: → Piperidine alkaloids from Piperretrofractum Vahl. (PRPAs), including piperine, pipernonaline, and dehydropipernonaline, are isolated as the anti-obesity constituents. → PRPA administration significantly reduces body weight gain without altering food intake and fat pad mass. → PRPA reduces high-fat diet-induced triglyceride accumulation in liver. → PRPAs attenuate HFD-induced obesity by activating AMPK and PPARδ, and regulate lipid metabolism, suggesting their potential anti-obesity effects. -- Abstract: The fruits of Piperretrofractum Vahl. have been used for their anti-flatulent, expectorant, antitussive, antifungal, and appetizing properties in traditional medicine, and they are reported to possess gastroprotective and cholesterol-lowering properties. However, their anti-obesity activity remains unexplored. The present study was conducted to isolate the anti-obesity constituents from P. retrofractum Vahl. and evaluate their effects in high-fat diet (HFD)-induced obese mice. Piperidine alkaloids from P. retrofractum Vahl. (PRPAs), including piperine, pipernonaline, and dehydropipernonaline, were isolated as the anti-obesity constituents through a peroxisome proliferator-activated receptor δ (PPARδ) transactivation assay. The molecular mechanism was investigated in 3T3-L1 adipocytes and L6 myocytes. PRPA treatment activated AMP-activated protein kinase (AMPK) signaling and PPARδ protein and also regulated the expression of lipid metabolism-related proteins. In the animal model, oral PRPA administration (50, 100, or 300 mg/kg/day for 8 weeks) significantly reduced HFD-induced body weight gain without altering the amount of food intake. Fat pad mass was reduced in the PRPA treatment groups, as evidenced by reduced adipocyte size. In addition, elevated serum levels of total cholesterol, low-density lipoprotein cholesterol, total lipid, leptin, and lipase were suppressed by PRPA treatment. PRPA also protected against the development of

  5. Piperidine alkaloids from Piperretrofractum Vahl. protect against high-fat diet-induced obesity by regulating lipid metabolism and activating AMP-activated protein kinase

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Jin [Department of Biomaterials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Lee, Myoung-Su; Jo, Keunae [Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Hwang, Jae-Kwan, E-mail: jkhwang@yonsei.ac.kr [Department of Biomaterials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Translational Research Center for Protein Functional Control, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2011-07-22

    Highlights: {yields} Piperidine alkaloids from Piperretrofractum Vahl. (PRPAs), including piperine, pipernonaline, and dehydropipernonaline, are isolated as the anti-obesity constituents. {yields} PRPA administration significantly reduces body weight gain without altering food intake and fat pad mass. {yields} PRPA reduces high-fat diet-induced triglyceride accumulation in liver. {yields} PRPAs attenuate HFD-induced obesity by activating AMPK and PPAR{delta}, and regulate lipid metabolism, suggesting their potential anti-obesity effects. -- Abstract: The fruits of Piperretrofractum Vahl. have been used for their anti-flatulent, expectorant, antitussive, antifungal, and appetizing properties in traditional medicine, and they are reported to possess gastroprotective and cholesterol-lowering properties. However, their anti-obesity activity remains unexplored. The present study was conducted to isolate the anti-obesity constituents from P. retrofractum Vahl. and evaluate their effects in high-fat diet (HFD)-induced obese mice. Piperidine alkaloids from P. retrofractum Vahl. (PRPAs), including piperine, pipernonaline, and dehydropipernonaline, were isolated as the anti-obesity constituents through a peroxisome proliferator-activated receptor {delta} (PPAR{delta}) transactivation assay. The molecular mechanism was investigated in 3T3-L1 adipocytes and L6 myocytes. PRPA treatment activated AMP-activated protein kinase (AMPK) signaling and PPAR{delta} protein and also regulated the expression of lipid metabolism-related proteins. In the animal model, oral PRPA administration (50, 100, or 300 mg/kg/day for 8 weeks) significantly reduced HFD-induced body weight gain without altering the amount of food intake. Fat pad mass was reduced in the PRPA treatment groups, as evidenced by reduced adipocyte size. In addition, elevated serum levels of total cholesterol, low-density lipoprotein cholesterol, total lipid, leptin, and lipase were suppressed by PRPA treatment. PRPA also

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

    Science.gov (United States)

    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...

  7. Obesity

    DEFF Research Database (Denmark)

    Heitmann, B L; Westerterp, K R; Loos, R J F

    2012-01-01

    programming for obesity via epigenetic changes in response to a 'Western diet' results in production of lipid-poor milk and metabolically efficient pups, contributing to the perpetuation of obesity throughout generations. Evolutionary insight from comparative physiology and ecology indicates that over...... generations activity-induced energy expenditure has remained the same compared to wild mammals, that energy balance might be dependant on protein balance, while the function of taste changed from detection of poison or energy to social drinking and social behaviour. At present, the impact of assortative...

  8. Leptine: an hormone secreted by adipose tissue. First study in Uruguayan population sample

    International Nuclear Information System (INIS)

    Pisabarro, Raul; Irrazabal, Ernesto; Recalde, Alicia; Barrios, Enrique; Arocena, Beatriz; Garcia Loriente, Jose Maria; Lorenzo Bonifazio, Juan

    1999-01-01

    The recent discovery of leptine, an hormone secreted by adipose tissue which modulates the energetic expenditure has signified a gigantic advance in studying obesity facts. In spite of a recent description of absence of leptine in humans, the obesity human model answers to leptine resistance. In this paper, we revise the actual concepts and show leptine values of a sample of 101 middle aged uruguayans, male and female, of normal weight and over weighted (table 1), correlated with corporal mass index (CMI) as an indirect measure of total body fat and waist diameter as an indirect measure of visceral fat, and hips (periferical fat). Bioimpedance studies were carried out to get the corporal composition. Results: good correlation between corporal fat and leptine, but fat distribution was not found representative. All in all, this data set confirms the correlation between leptine and total body fat mass

  9. Genome-wide analysis identifies colonic genes differentially associated with serum leptin and insulin concentrations in C57BL/6J mice fed a high-fat diet.

    Directory of Open Access Journals (Sweden)

    Sung-Eun Kim

    Full Text Available Obesity-induced chronic inflammation is known to increase the risk of ulcerative colitis, Crohn's disease, and colorectal cancer. Accumulating evidence suggests that leptin and insulin are key molecules linking obesity with diseases of the lower intestine. Here, we identified serum phenotype-associated genes in the colon of diet-induced obese mice as early biomarkers of obesity-associated colonic diseases. C57BL/6J mice were fed with either normal diet (ND, 15% of fat calories or high-fat diet (HFD, 45% of fat calories for 8 weeks. Serum concentrations of insulin, insulin-like growth factor-1 (IGF-1, leptin, and adiponectin were measured as obesity-related phenotypic markers. Genome-wide gene expression profiles of colon tissue were determined, followed by statistical analyses to detect differentially expressed and serum phenotype-associated genes. HFD-fed mice showed higher serum concentrations of leptin (P < 0.001 and insulin (P < 0.01 than those in the ND group, whereas serum IGF-1 and adiponectin concentrations did not differ between the two dietary groups. Among differentially expressed genes affected by HFD, 135, 128, 110, and 341 genes were associated with serum levels of leptin, insulin, IGF-1, and adiponectin, respectively. We identified 17 leptin-associated genes and 4 insulin-associated genes that inversely responded to HFD and ND. Among these, leptin-associated Peli3 (Pellino E3 ubiquitin protein ligase family member 3, Creb1 (cAMP responsive element binding protein 1, and Enpp2 (ectonucleotide pyrophosphatase/phosphodiesterase 2, autotaxin and insulin-associated Centg1 (AGAP2, ArfGAP with GTPase domain are reported to play a role either in obesity or colonic diseases. mRNA expression of these genes was validated by RT-qPCR. Our data suggest Peli3, Creb1, Enpp2, and Centg1 as potential early biomarker candidates for obesity-induced pathophysiological changes in the colon. Future studies verifying the function of these candidates are

  10. Responses of gut microbiota and glucose and lipid metabolism to prebiotics in genetic obese and diet-induced leptin-resistant mice

    NARCIS (Netherlands)

    Everard, A.; Derrien, M.M.N.; Possemiers, S.; Vos, de W.M.; Delzenne, N.M.; Schrenzel, J.; Cani, P.D.

    2011-01-01

    OBJECTIVE To investigate deep and comprehensive analysis of gut microbial communities and biological parameters after prebiotic administration in obese and diabetic mice. RESEARCH DESIGN AND METHODS Genetic (ob/ob) or diet-induced obese and diabetic mice were chronically fed with prebiotic-enriched

  11. Uncoupled protein 3 and p38 signal pathways are involved in anti-obesity activity of Solanum tuberosum L. cv. Bora Valley.

    Science.gov (United States)

    Yoon, Sung-Soo; Rhee, Yun-Hee; Lee, Hyo-Jung; Lee, Eun-Ok; Lee, Min-Ho; Ahn, Kyoo-Seok; Lim, Hak-Tae; Kim, Sung-Hoon

    2008-08-13

    This study was undertaken to elucidate the anti-obesity mechanism of a new purple potato variety that has been used for the prevention of metabolic diseases as a folk remedy in Korea. Proliferation assay, differentiation assay, Western blotting, were performed in 3T3-L1 adipocytes, while blood chemistry for hyperlipidemic parameters, measurement of body weight and abdominal fats, reverse transcriptase-polymerase chain reaction (RT-PCR) analysis, magnetic resonance image (MRI) scanning were carried out in high fat diet fed Sprague-Dawley rats with ethanol extract of Solanum tuberosum L. cv. Bora Valley (ESTBV). ESTBV significantly inhibited the proliferation and differentiation of 3T3-L1 cells as well as reduced the cellular leptin level. ESTBV also significantly attenuated the levels of insulin and leptin at 500mg/kg in high fat diet fed rats. In addition, ESTBV significantly reduced total fat and whole body lipid in a therapeutic experiment, which was confirmed by MRI scanning and also significantly inhibited the retroperitoneal and epididymal fats in a preventive experiment compared with control. Similarly, the levels of total cholesterol, triglyceride and low density lipoprotein (LDL) were significantly reduced at a lower dose 200mg/kg of ESTBV in a preventive experiment than at 500mg/kg in a therapeutic experiment. Furthermore, body weight gain was significantly suppressed by over 4 weeks treatment of ESTBV compared with control. Interestingly, the expression of p38 mitogen-activated protein kinase (MAPK) was significantly downregulated in 3T3-L1 cells by ESTBV and the expression of uncoupled protein 3 (UCP-3) was activated in fats and liver tissues of ESTBV treated group compared with high fat diet control. ESTBV has anti-obesity potential via inhibition of lipid metabolism through p38 MAPK and UCP-3 pathways.

  12. The hypothalamic- pituitary -adrenal -leptin axis and metabolic health: A systems approach to resilience, robustness and control

    NARCIS (Netherlands)

    Aschbacher, K.; Rodriguez-Fernandez, M.; Wietmarschen, H. van; Tomiyama, A.; Jain, S.; Epel, E.; Doyle III, F.J.; Greef, J. van der

    2014-01-01

    Glucocorticoids contribute to obesity and metabolic syndrome; however, the mechanisms are unclear, and prognostic measures are unavailable. A systems level understanding of the hypothalamic-pituitary-adrenal (HPA) -leptin axis may reveal novel insights. Eighteen obese premenopausal women provided

  13. Adiponectin,leptin: focus on low-protein diet supplemented with keto acids in chronic glomerulonephritis with hbv patients

    Directory of Open Access Journals (Sweden)

    Shan Mou

    2012-06-01

    In conclusion: Short-term restriction of DPI 0.6–0.8 g of protein/ kg IBW/day is safe, when combined with keto acids, is associated with decreased of urinary protein and improvement of lipid metabolism

  14. Effect of body mass index on serum leptin levels

    International Nuclear Information System (INIS)

    Paul, R.F.; Hassan, M.; Nazar, H.S.

    2012-01-01

    Background: Leptin is product of ob gene, an adipose tissue derived hormone that plays a key role in the regulation of body fat mass by regulating appetite and metabolism while balancing energy intake and energy expenditure. The objective of the study was to evaluate possible association between serum leptin levels and Body Mass Index (BMI) of gender in adult age group. Methods: Two-hundred-seventy subjects aged 20-50 years were randomly selected from general population of Abbottabad. The subjects were grouped on the basis on BMI (89 normal, 92 overweight, and 89 obese). After complete evaluation, demographic data was recorded and BMI. Non-fasting venous blood samples were drawn to measure serum leptin and serum glucose levels. The data were analysed using SPSS-15 calculating mean, percentage, independent t-test and chi-square test. Correlation and regression curve analysis were obtained, and p and r values were calculated. Results: Serum leptin levels and differences between genders were significant in all body mass indices. For normal BMI group the mean values for leptin were 2.6+-1.5 gamma g/ml in men, and 17.3+9-10.2 gamma g/ml for women. For Group-2 mean leptin levels in men were 9.9+-6.8 gamma g/ml and in women were 34.8+-13.6 gamma g/ml. For Group-3 BMI comprising obese subjects mean values for men were 21.3+-14.2 gamma g/ml and for women were 48.21+-21.2 gamma g/ml (p<0.001). Conclusion: A progressive increase in serum leptin concentration was observed with an increase in BMI. Significant difference between leptin concentrations in either gender was found in normal, overweight and obese subjects. (author)

  15. Leptin impairs myogenesis in C2C12 cells through JAK/STAT and MEK signaling pathways.

    Science.gov (United States)

    Pijet, Maja; Pijet, Barbara; Litwiniuk, Anna; Pajak, Beata; Gajkowska, Barbara; Orzechowski, Arkadiusz

    2013-02-01

    Reduced lean body mass in genetically obese (ob/ob) or anorectic/cachectic subjects prompted us to verify the hypothesis whether leptin, white adipose tissue cytokine, might be a negative organizer of myogenesis. Recombinant leptin (100 ng/mL) stimulated mitogenesis together with the raise in T(202/)Y(204)P-ERK1/2 protein expression. Concomitantly, it impaired cell viability and muscle fiber formation from C2C12 mouse myoblasts. Detailed acute and chronic studies with the use of metabolic inhibitors revealed that both JAK/STAT3 and MEK/MAPK but not PI3-K/AKT/GSK-3β signaling pathways were activated by leptin, and that STAT3 (Y(705)P-STAT3) and MEK (T(202/)Y(204)P-ERK1/2) mediate these effects. In contrary, insulin evoked PI3-K-dependent phosphorylation of AKT (S(473)) and GSK-3β (S(9)) and insulin surpassed leptin-dependent inhibition of myogenic differentiation in PI3-K-dependent manner. GSK-3β seems to play dual role in muscle development. Insulin-dependent effect on GSK-3β (S(9)P-GSK-3β) led to accelerated myotube construction. In contrary, leptin through MEK-dependent manner caused GSK-3β phosphorylation (Y(216)P-GSK-3β) with resultant drop in myoblast fusion. Summing up, partially opposite effects of insulin and leptin on skeletal muscle growth emphasize the importance of interplay between these cytokines. They determine how muscle mass is gained or lost. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. 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.

  17. Leptin and its potential interest in assisted reproduction cycles.

    Science.gov (United States)

    Catteau, A; Caillon, H; Barrière, P; Denis, M G; Masson, D; Fréour, T

    2016-04-01

    Leptin, an adipose hormone, has been shown to control energy homeostasis and food intake, and exert many actions on female reproductive function. Consequently, this adipokine is a pivotal factor in studies conducted on animal models and humans to decipher the mechanisms behind the infertility often observed in obese women. A systematic PubMed search was conducted on all articles, published up to January 2015 and related to leptin and its actions on energy balance and reproduction, using the following key words: leptin, reproduction, infertility, IVF and controlled ovarian stimulation. The available literature was reviewed in order to provide an overview of the current knowledge on the physiological roles of leptin, its involvement in female reproductive function and its potential interest as a prognostic marker in IVF cycles. Animal and human studies show that leptin communicates nutritional status to the central nervous system and emerging evidence has demonstrated that leptin is involved in the control of reproductive functions by acting both directly on the ovaries and indirectly on the central nervous system. With respect to the clinical use of leptin as a biomarker in IVF cycles, a systematic review of the literature suggested its potential interest as a predictor of IVF outcome, as high serum and/or follicular fluid leptin concentrations have correlated negatively with cycle outcome. However, these preliminary results remain to be confirmed. Leptin regulates energy balance and female reproductive function, mainly through its action on hypothalamic-pituitary-ovarian function, whose molecular and cellular aspects are progressively being deciphered. Preliminary studies evaluating leptin as a biomarker in human IVF seem promising but need further confirmation. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. Important mitochondrial proteins in human omental adipose tissue show reduced expression in obesity

    Directory of Open Access Journals (Sweden)

    Peter W. Lindinger

    2015-09-01

    Full Text Available Obesity is associated with impaired mitochondrial function. This study compares mitochondrial protein expression in omental fat in obese and non-obese humans. Omental adipose tissue was obtained by surgical biopsy, adipocytes were purified and mitochondria isolated. Using anion-exchange chromatography, SDS-PAGE and mass-spectrometry, 128 proteins with potentially different abundances in patient groups were identified, 62 of the 128 proteins are mainly localized in the mitochondria. Further quantification of 12 of these 62 proteins by immune dot blot analysis revealed four proteins citrate synthase, HADHA, LETM1 and mitofilin being inversely associated with BMI, and mitofilin being inversely correlated with gender.

  19. Important mitochondrial proteins in human omental adipose tissue show reduced expression in obesity.

    Science.gov (United States)

    Lindinger, Peter W; Christe, Martine; Eberle, Alex N; Kern, Beatrice; Peterli, Ralph; Peters, Thomas; Jayawardene, Kamburapola J I; Fearnley, Ian M; Walker, John E

    2015-09-01

    Obesity is associated with impaired mitochondrial function. This study compares mitochondrial protein expression in omental fat in obese and non-obese humans. Omental adipose tissue was obtained by surgical biopsy, adipocytes were purified and mitochondria isolated. Using anion-exchange chromatography, SDS-PAGE and mass-spectrometry, 128 proteins with potentially different abundances in patient groups were identified, 62 of the 128 proteins are mainly localized in the mitochondria. Further quantification of 12 of these 62 proteins by immune dot blot analysis revealed four proteins citrate synthase, HADHA, LETM1 and mitofilin being inversely associated with BMI, and mitofilin being inversely correlated with gender.

  20. Serum leptin levels correlation with high blood pressure in adult females

    International Nuclear Information System (INIS)

    Haque, Z.; Shahid, K.U.; Mazahir, I.; Lakho, G.R.; Nafees, M.

    2006-01-01

    To measure serum leptin levels and compare them in lean and obese subjects and to identify correlation between serum leptin levels, heart rate and hypertension in lean and obese subjects among adult females. Seventy female subjects with different body mass indices were selected from OPD of Jinnah Medical and Dental College Hospital (OPD), Karachi. Heart rate was counted manually; blood pressure was measured by mercury sphygmomanometer while serum leptin was measured using enzyme-linked immunoassay. The outcomes hypertension and heart rate were correlated to risk factor leptin. Mean heart rate, systolic and diastolic blood pressure and serum leptin levels of obese people were 90+-1, 142+-2, 89+-1 and 24.13+-1.7 respectively, which were significantly higher as compared to lean subjects (p<0.05). All the parameters correlated positively and significantly with increasing BMI. There was a relationship of tachycardia and hypertension with high serum leptin levels in obesity. Serum leptin levels increase with the level of obesity. Hyper-leptinemia is associated with tachycardia and increases in both systolic and diastolic blood pressure in obesity via complex mechanisms. (author)

  1. Role of leptin as a link between metabolism and the immune system.

    Science.gov (United States)

    Pérez-Pérez, Antonio; Vilariño-García, Teresa; Fernández-Riejos, Patricia; Martín-González, Jenifer; Segura-Egea, Juan José; Sánchez-Margalet, Víctor

    2017-06-01

    Leptin is an adipocyte-derived hormone not only with an important role in the central control of energy metabolism, but also with many pleiotropic effects in different physiological systems. One of these peripheral functions of leptin is a regulatory role in the interplay between energy metabolism and the immune system, being a cornerstone of the new field of immunometabolism. Leptin receptor is expressed throughout the immune system and the regulatory effects of leptin include cells from both the innate and adaptive immune system. Leptin is one of the adipokines responsible for the inflammatory state found in obesity that predisposes not only to type 2 diabetes, metabolic syndrome and cardiovascular disease, but also to autoimmune and allergic diseases. Leptin is an important mediator of the immunosuppressive state in undernutrition status. Placenta is the second source of leptin and it may play a role in the immunomodulation during pregnancy. Finally, recent work has pointed to the participation of leptin and leptin receptor in the pathophysiology of inflammation in oral biology. Therefore, leptin and leptin receptor should be considered for investigation as a marker of inflammation and immune activation in the frontier of innate-adaptive system, and as possible targets for intervention in the immunometabolic mediated pathophysiology. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. What fans the fire: insights into mechanisms of leptin in metabolic syndrome-associated heart diseases.

    Science.gov (United States)

    Dong, Maolong; Ren, Jun

    2014-01-01

    Obesity and metabolic syndrome are one of the most devastating risk factors for cardiovascular diseases. The obesity gene product leptin plays a central role in the regulation of food intake and energy expenditure. The physiological and pathophysiological roles of leptin in cardiovascular system have been investigated extensively since its discovery in 1994. In addition to its well-established metabolic effects, more recent evidence have depicted a rather pivotal role of leptin in inflammation, oxidative stress, endoplasmic reticulum stress, apoptosis and tissue remodeling en route to the pathogenesis of type 2 diabetes mellitus, hypertension, atherosclerosis, and insulin resistance. Under physiological condition, leptin is known to reduce appetite, promote energy expenditure, increase sympathetic activity, facilitate glucose utilization and improve insulin sensitivity. In addition, leptin may regulate cardiac and vascular function through a nitric oxide-dependent mechanism. However, hyperleptinemia usually occurs with progressively increased body weight and metabolic syndrome development, leading to a state of global or selective leptin resistance. Both central and peripheral leptin resistance may be present under pathophysiological conditions such as inflammation, insulin resistance, hyperlipidemia and a cadre of other cardiovascular diseases including hypertension, atherosclerosis, obesity, ischemic heart disease and heart failure. In this review, we will discuss cardiovascular actions of leptin related to various components of metabolic syndrome. Particular emphasis will be given to insights derived from therapeutic interventions with lifestyle modification, cardiovascular drugs, anti-diabetic and anti-obesity drugs.

  3. Effect of Green Tea Extract-Enriched Diets on Insulin and Leptin Levels, Oxidative Stress Parameters and Antioxidant Enzymes Activities in Obese Mice

    Directory of Open Access Journals (Sweden)

    Bártíková Hana

    2017-09-01

    Full Text Available Green tea and green tea extracts (GTE are often incorporated into diet intended to weight reduction, although the information about their efficacy in obese individuals is insufficient. The present study was designed to follow up the effect of defined and standardized GTE in mice with obesity induced by monosodium L-glutamate. Obese mice were fed with GTE-supplemented diet in three dosage regimens: 28-day and 3-day intake of 1 g GTE in 1 kg of diet and 28-day intake of 0.1 g GTE in 1 kg of diet. The information on body weight, food intake, oxidation stress parameters in blood and antioxidant enzymes activity in liver and small intestine was obtained. High doses of GTE decreased the specific activities of glutathione reductase and catalase and increased concentrations of malondialdehyde in blood. Specific activities of antioxidant enzymes in the liver and small intestine were not altered after GTE treatment except the decrease of NAD(PH:quinone oxidoreductase activity. Our results showed that GTE did not affect average body weight and did not markedly improve antioxidant status in glutamate-induced obese mice. Moreover, intake of high doses of GTE made antioxidant defense in obese animals even worse.

  4. Leptin as immune mediator: Interaction between neuroendocrine and immune system.

    Science.gov (United States)

    Procaccini, Claudio; La Rocca, Claudia; Carbone, Fortunata; De Rosa, Veronica; Galgani, Mario; Matarese, Giuseppe

    2017-01-01

    Leptin is an adipocyte-derived hormone/cytokine that links nutritional status with neuroendocrine and immune functions. Initially described as an anti-obesity hormone, leptin has subsequently been shown to exert pleiotropic effects, being also able to influence haematopoiesis, thermogenesis, reproduction, angiogenesis, and more importantly immune homeostasis. As a cytokine, leptin can affect both innate and adaptive immunity, by inducing a pro-inflammatory response and thus playing a key role in the regulation of the pathogenesis of several autoimmune/inflammatory diseases. In this review, we discuss the most recent advances on the role of leptin as immune-modulator in mammals and we also provide an overview on its main functions in non-mammalian vertebrates. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Serum leptin is correlated to high turnover in osteoporosis.

    Science.gov (United States)

    Hipmair, Gunter; Böhler, Nikolaus; Maschek, Wilma; Soriguer, Federico; Rojo-Martínez, Gemma; Schimetta, Wolfgang; Pichler, Robert

    2010-01-01

    Clinical data have suggested that obesity protects against osteoporosis. Leptin, mainly secreted by white adipose tissue, might be involved by mediating an effect on bone metabolism. This study was conducted to investigate a possible relationship of leptin and bone turn-over in postmenopausal women with osteoporosis. We measured bone mineral density (BMD), serum leptin levels and markers of bone metabolism, including osteocalcin and cross-laps in 44 patients with osteoporosis. The main group consisted of 32 postmenopausal women. Mean serum leptin was 13.1 microg/L and showed no statistically significant difference to the levels measured in a collective of normal persons adjusted for age and BMI. When related to serum cross-laps as markers of bone resorption, a positive correlation (pturnover serum bone markers, at least in postmenopausal women with osteoporosis.

  6. Influence of ALA54THR polymorphism of fatty acid binding protein 2 on lifestyle modification response in obese subjects.

    Science.gov (United States)

    de Luis, D A; Aller, R; Izaola, O; Sagrado, M Gonzalez; Conde, R

    2006-01-01

    It has been found that the expression of fatty acid binding protein 2 (FABP2) mRNA is under dietary control. A G-to-A transition at codon 54 of FABP2 results in an amino acid substitution (from Ala 54 to Thr 54). This polymorphism was associated with high insulin resistance and high fasting insulin concentrations. The aim of our study was to investigate the influence of Thr54 polymorphism in the FABP2 protein on the response to a lifestyle modification (Mediterranean hypocaloric diet and exercise) in obese patients. A population of 69 obese (body mass index > 30) nondiabetic outpatients was analyzed in a prospective way. Before and after 3 months of the lifestyle modification program, indirect calorimetry, tetrapolar electrical bioimpedance measurement, blood pressure recording, serial assessment of the nutritional intake (3 days of written food records), and biochemical analysis were performed. The lifestyle modification program consisted of a hypocaloric diet (1,520 kcal; 52% carbohydrates, 25% lipids, and 23% proteins). The exercise program consisted of aerobic exercise for at least three times/week (60 min each). Statistical analysis was performed for combined Ala54/Thr54 and Thr54/Thr54 as a mutant group and wild-type Ala54/Ala54 as second group. The mean age was 45.5 +/- 16.7 years, the mean body mass index was 34.1 +/- 5.1, and there were 14 males (20.3%) and 55 females (79.7%) with a weight loss of 3.17 +/- 3.5 kg (3.5%). Thirty-seven patients (53.6%) had the genotype Ala54/Ala54 (wild-type group) and 32 (46.4%) patients either the genotype Ala54/Thr54 (26 patients, 30.2%) or the genotype Thr54/Thr54 (6 patients, 16.2%). The percentage of responders (weight loss) was similar in both groups (89.2 vs. 90.6%). In the wild-type group, body mass index, weight, fat mass, low-density lipoprotein cholesterol level, and waist circumference decreased, whereas the VO2 (oxygen consumption) increased. In the mutant group, glucose, body mass index, weight, waist

  7. Leptin and adiponectin DNA methylation levels in adipose tissues and blood cells are associated with BMI, waist girth and LDL-cholesterol levels in severely obese men and women.

    Science.gov (United States)

    Houde, Andrée-Anne; Légaré, Cécilia; Biron, Simon; Lescelleur, Odette; Biertho, Laurent; Marceau, Simon; Tchernof, André; Vohl, Marie-Claude; Hivert, Marie-France; Bouchard, Luigi

    2015-05-01

    Leptin (LEP) and adiponectin (ADIPOQ) genes encode adipokines that are mainly secreted by adipose tissues, involved in energy balance and suspected to play a role in the pathways linking adiposity to impaired glucose and insulin homeostasis. We have thus hypothesized that LEP and ADIPOQ DNA methylation changes might be involved in obesity development and its related complications. The objective of this study was to assess whether LEP and ADIPOQ DNA methylation levels measured in subcutaneous (SAT) and visceral adipose tissues (VAT) are associated with anthropometric measures and metabolic profile in severely obese men and women. These analyses were repeated with DNA methylation profiles from blood cells obtained from the same individuals to determine whether they showed similarities. Paired SAT, VAT and blood samples were obtained from 73 severely obese patients undergoing a bioliopancreatic diversion with duodenal switch. LEP and ADIPOQ DNA methylation and mRNA levels were quantified using bisulfite-pyrosequencing and qRT-PCR respectively. Pearson's correlation coefficients were computed to determine the associations between LEP and ADIPOQ DNA methylation levels, anthropometric measures and metabolic profile. DNA methylation levels at the ADIPOQ gene locus in SAT was positively associated with BMI and waist girth whereas LEP DNA methylation levels in blood cells were negatively associated with body mass index (BMI). Fasting LDL-C levels were found to be positively correlated with DNA methylation levels at LEP-CpG11 and -CpG17 in blood and SAT and with ADIPOQ DNA methylation levels in SAT (CpGE1 and CpGE3) and VAT (CpGE1). These results confirm that LEP and ADIPOQ epigenetic profiles are associated with obesity. We also report associations between LDL-C levels and both LEP and ADIPOQ DNA methylation levels suggesting that LDL-C might regulate their epigenetic profiles in adipose tissues. Furthermore, similar correlations were observed between LDL-C and LEP blood

  8. Benefits of resistance exercise in lean women with fibromyalgia: involvement of IGF-1 and leptin.

    Science.gov (United States)

    Bjersing, Jan L; Larsson, Anette; Palstam, Annie; Ernberg, Malin; Bileviciute-Ljungar, Indre; Löfgren, Monika; Gerdle, Björn; Kosek, Eva; Mannerkorpi, Kaisa

    2017-03-14

    Chronic pain and fatigue improves by exercise in fibromyalgia (FM) but underlying mechanisms are not known. Obesity is increased among FM patients and associates with higher levels of pain. Symptom improvement after aerobic exercise is affected by body mass index (BMI) in FM. Metabolic factors such as insulin-like growth factor 1 (IGF-1) and leptin may be involved. In this study, the aim was to evaluate the role of metabolic factors in lean, overweight and obese women during resistance exercise, in relation to symptom severity and muscle strength in women with FM. Forty-three women participated in supervised progressive resistance exercise, twice weekly for 15-weeks. Serum free and total IGF-1, IGF-binding protein 3 (IGFBP3), adiponectin, leptin and resistin were determined at baseline and after 15-weeks. Level of current pain was rated on a visual analogue scale (0-100 mm). Level of fatigue was rated by multidimensional fatigue inventory (MFI-20) subscale general fatigue (MFIGF). Knee extension force, elbow flexion force and handgrip force were assessed by dynamometers. Free IGF-1 (p = 0.047), IGFBP3 (p = 0.025) and leptin (p = 0.008) were significantly decreased in lean women (n = 18), but not in the overweight (n = 17) and the obese (n = 8). Lean women with FM benefited from resistance exercise with improvements in current pain (p= 0.039, n = 18), general fatigue (MFIGF, p = 0.022, n = 18) and improved elbow-flexion force (p = 0.017, n = 18). In overweight and obese women with FM there was no significant improvement in pain or fatigue but an improvement in elbow flexion (p = 0.049; p = 0.012) after 15 weeks of resistance exercise. The clearest clinical response to resistance exercise was found in lean patients with FM. In these individuals, individualized resistance exercise was followed by changes in IGF-1 and leptin, reduced pain, fatigue and improved muscular strength. In overweight and obese women FM

  9. Prenatal caffeine exposure induced a lower level of fetal blood leptin mainly via placental mechanism

    International Nuclear Information System (INIS)

    Wu, Yi-meng; Luo, Han-wen; Kou, Hao; Wen, Yin-xian; Shen, Lang; Pei, Ling-guo; Zhou, Jin; Zhang, Yuan-zhen; Wang, Hui

    2015-01-01

    It's known that blood leptin level is reduced in intrauterine growth retardation (IUGR) fetus, and placental leptin is the major source of fetal blood leptin. This study aimed to investigate the decreased fetal blood leptin level by prenatal caffeine exposure (PCE) and its underlying placental mechanisms. Pregnant Wistar rats were intragastrically administered caffeine (30–120 mg/kg day) from gestational day 9 to 20. The level of fetal serum leptin and the expression of placental leptin-related genes were analyzed. Furthermore, we investigated the molecular mechanism of the reduced placental leptin's expression by treatment with caffeine (0.8–20 μM) in the BeWo cells. In vivo, PCE significantly decreased fetal serum leptin level in caffeine dose-dependent manner. Meanwhile, placental mRNA expression of adenosine A2a receptor (Adora2a), cAMP-response element binding protein (CREB), a short-type leptin receptor (Ob-Ra) and leptin was reduced in the PCE groups. In vitro, caffeine significantly decreased the mRNA expression of leptin, CREB and ADORA2A in concentration and time-dependent manners. The addition of ADORA2A agonist or adenylyl cyclase (AC) agonist reversed the inhibition of leptin expression induced by caffeine. PCE induced a lower level of fetal blood leptin, which the primary mechanism is that caffeine inhibited antagonized Adora2a and AC activities to decreased cAMP synthesis, thus inhibited the expression of the transcription factor CREB and target gene leptin in the placenta. Meantime, the reduced transportation of maternal leptin by placental Ob-Ra also contributed to the reduced fetal blood leptin. Together, PCE decreased fetal blood leptin mainly via reducing the expression and transportation of leptin in the placenta. - Highlights: • Caffeine reduced fetal blood leptin level. • Caffeine inhibited placental leptin production and transport. • Caffeine down-regulated placental leptin expression via antagonizing ADORA2. • Caffeine

  10. Modification of the β-Adrenoceptor Stimulation Pathway in Zucker Obese and Obese Diabetic Rat Myocardium.

    Science.gov (United States)

    Jiang, Cheng; Carillion, Aude; Na, Na; De Jong, Audrey; Feldman, Sarah; Lacorte, Jean-Marc; Bonnefont-Rousselot, Dominique; Riou, Bruno; Amour, Julien

    2015-07-01

    Although metabolic syndrome is associated with increased sympathetic activity that chronically stimulates β-adrenoceptors, the β-adrenoceptor signaling pathway has been poorly studied in this situation. We studied the β-adrenoceptor signaling pathway in Zucker lean, obese, and obese diabetic rats. Experimental, prospective study. University medical research laboratory. Adult male Zucker lean (control), obese, and obese diabetic rats. The effects of β-adrenoceptor stimulation were investigated in vitro in isolated left ventricular papillary muscles in control, obese, and obese diabetic rats. β1-, β2-, and β3-adrenoceptors and multidrug resistance-associated protein 4 were quantified by Western Blotting. Triglyceride, cholesterol, leptin, adiponectin, and C-peptide plasma concentrations were measured. Data are mean ± SD. Hyperlipidemia, high leptin, and C-peptide concentrations were observed in obese and obese diabetic strains, whereas hyperglycemia occurred only in the diabetic strain. The positive inotropic effect of isoproterenol was slightly reduced in obese rats (183% ± 11% of baseline; p = 0.003; n = 7) and markedly reduced in obese diabetic rats (137% ± 18% of baseline; p < 0.001; n = 10) when compared with control rats (210% ± 17% of baseline; n = 9). β1-adrenoceptors were down-regulated in obese (-41%; p = 0.02) and diabetic (-54%; p = 0.003) when compared with control rats, whereas β3-adrenoceptors and multidrug resistance-associated protein expression remained unchanged. Direct stimulation of adenylate cyclase with forskolin or administration of 3',5'-cyclic adenosine monophosphate suggests that subtle impairments also occurred beside the down-regulation of β1-adrenoceptor. The positive inotropic effect of β-adrenoceptor stimulation is slightly decreased in Zucker obese rats and was more markedly decreased in Zucker diabetic rats. These decreases are mainly related to β1-adrenoceptor down-regulation.

  11. The Gln223Arg polymorphism in the leptin receptor is associated with familial combined hyperlipidemia.

    NARCIS (Netherlands)

    Vleuten, G.M. van der; Kluijtmans, L.A.J.; Hijmans, A.G.M.; Blom, H.J.; Stalenhoef, A.F.H.; Graaf, J. de

    2006-01-01

    OBJECTIVE: Familial combined hyperlipidemia (FCH) is characterized by elevated levels of total cholesterol (TC), triglycerides (TG) and apolipoprotein B (apo B) and is associated with premature cardiovascular disease (CVD). Other features of FCH are obesity and insulin resistance. Serum leptin

  12. Leptin concentrations do not predict weight gain: the Mexico City Diabetes Study.

    Science.gov (United States)

    Haffner, S M; Mykkänen, L A; Gonzalez, C C; Stern, M P

    1998-07-01

    Leptin, a hormone which is produced by adipose tissue, has been shown to inhibit food intake and increase energy expenditure. In humans, leptin levels are correlated with body fat. In addition, leptin levels decline in subjects who lose weight. Yet few data exist on whether leptin levels predict weight change, except for a recent report suggesting that low leptin levels predict weight gain in very obese middle-aged Pima Indians. We have examined the association between baseline leptin levels and subsequent weight gain over 3.25 y in 180 non-diabetic participants in the Mexico City Diabetes Study. At baseline, the correlation between leptin levels and body mass index (BMI) was 0.712 in men and 0.691 in women (both P BMI (+/- 2 kg/m2) at baseline. Baseline BMI was 25.3 kg/m2 in men and 27.2 kg/m2 in women. Baseline leptin levels (ng/ml) did not predict weight gain in either men (weight gainers: 4.3; weight stable: 5.8; and weight losers: 5.2) or women (weight gainers: 17.4; weight stable: 17.7; and weight losers: 17.4). We conclude that baseline leptin levels did not predict weight change in moderately obese individuals.

  13. [Relationship between leptin and body mass and metabolic syndrome in an adult population].

    Science.gov (United States)

    Martins, Maria do Carmo; Lima Faleiro, Luís; Fonseca, Aidil

    2012-11-01

    To analyze the relationship between leptin and obesity expressed as body mass index (BMI) and certain components of the metabolic syndrome (MS) in an adult population. The study included 103 subjects, 42 men and 61 women, aged over 30 years, clinically defined as non-diabetic but with personal or family history of cardiovascular disease. All subjects underwent fasting blood measurements of leptin, insulin, glucose, glucose after ingestion of 75g glucose, HDL cholesterol and triglycerides, and insulin resistance (IR) and BMI were calculated. BMI as an index of overall adiposity was strongly associated with serum leptin. BMI rose as serum leptin levels increased from the first to the third tertile; the correlation between leptin and BMI was strong, r=0.524 in men and r=0.603 in women, with high statistical significance (pcorrelations between leptin and IR, and leptin and insulinemia, were strong in both sexes. With regard to MS components, increased serum levels of the study variables were observed as leptin concentrations rose from the first to the third tertile (with the exception of HDL cholesterol, which decreased). Elevated serum leptin, particularly in obese individuals, should be taken as a warning sign of energy imbalance, poor diet, hyperinsulinemia, insulin resistance, or changes in other metabolic risk factors that are strongly associated with cardiovascular disease and type 2 diabetes. Copyright © 2011 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  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. 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.

  16. Maternal leptin and body composition in the first trimester of pregnancy.

    LENUS (Irish Health Repository)

    Fattah, Chro

    2012-02-01

    BACKGROUND: Leptin is produced mainly by adipocytes. Levels are increased in women with obesity and during pregnancy. Increased levels are also associated with pregnancy complications such as, pre-eclampsia and gestational diabetes mellitus. OBJECTIVE: We studied what component of body composition correlated best with maternal leptin in the first trimester of pregnancy and, whether maternal leptin correlated better with visceral fat rather than fat distributed elsewhere. SUBJECTS AND METHODS: Women were recruited in the first trimester. Maternal adiposity was measured using body mass index and advanced bioelectrical impedance analysis. Maternal leptin was measured using an enzyme-linked immunosorbent assay technique. RESULTS: Of the 100 subjects studied, the mean leptin concentration was 37.7 ng\\/ml (range: 2.1-132.8). Leptin levels did not correlate with gestational age in the first trimester, maternal age, parity or birth weight. Serum leptin correlated positively with maternal weight and body mass index, and with the different parameters of body composition. On multiple regression analysis, serum leptin correlated with visceral fat but not fat distributed elsewhere. CONCLUSIONS: Visceral fat is the main determinant of circulating maternal leptin in the first trimester of pregnancy. This raises the possibility that maternal leptin in early pregnancy may be a marker for the development of metabolic syndrome, including diabetes mellitus.

  17. Serum leptin concentration in patients with type 2 diabetes

    Directory of Open Access Journals (Sweden)

    Malecha-Jedraszek Arleta

    2015-12-01

    Full Text Available With the increasing importance of early type 2 diabetes (DM2 and obesity detection, it is useful to reevaluate leptin role in these conditions. Our study aimed at investigating circulating leptin concentrations in a group of patients with DM2, and at assessing in detail whether leptin concentrations correlate with selected biochemical, clinical parameters and markers of systemic inflammation in patients with DM2 and in healthy volunteers. In our work, we analysed samples and data drawn from 71 patients aged 61.4 ± 11.7 years, who have been diagnosed with type 2 diabetes, as well as from a healthy control group (HC consisting of 51 healthy subjects with a mean age of 57.8 ± 13.7 years. Therein, the concentration of leptin in the DM2 patients was significantly higher than in the HC (p < 0.01, with median value of 16.59 (IQR 8.58-33.39 ng/ml in the DM2, vs median value of 6.66 (IQR 4.52-21.40 ng/ml in the HC. In the analysis of variance, higher leptin concentrations were revealed in the DM2 group as compared to the HC, and this figure remained significant after adjusting for gender and age (p < 0.001. Moreover, it was independent of HOMA-IR (p = 0.003. However, the differences in leptin levels between the groups disappeared when additional adjustments for anthropometric parameters (BMI, waist circumference were applied (p = 0.088. Beyond the aforementioned, significant positive correlations were found in the DM 2 group between leptin level and CRP (r=0.256; p < 0.05 and IL-6 (r = 0.345; p < 0.01. Among the selected variables, only gender and BMI were included in the predictive model explaining the variability of leptin, and, in total, were responsible for 72.6% of the original variation of the studied adipocytokine. The results of this study have led to conclusion that leptin may participate in the complex pathogenesis of DM2 and be a predictor of the development of this disease. As higher concentrations of leptin coexist with obesity, and this

  18. The role of leptin in gastric cancer: Clinicopathologic features and molecular mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kang Nyeong [Department of Internal Medicine, Hanyang University College of Medicine, Seoul (Korea, Republic of); Choi, Ho Soon, E-mail: hschoi96@hanyang.ac.kr [Department of Internal Medicine, Hanyang University College of Medicine, Seoul (Korea, Republic of); Yang, Sun Young [Department of Internal Medicine, Healthcare Research Institute, Seoul National University Hospital Healthcare System Gangnam Center, Seoul (Korea, Republic of); Park, Hyun Ki; Lee, Young Yiul; Lee, Oh Young; Yoon, Byung Chul; Hahm, Joon Soo [Department of Internal Medicine, Hanyang University College of Medicine, Seoul (Korea, Republic of); Paik, Seung Sam [Pathology, Hanyang University College of Medicine, Seoul (Korea, Republic of)

    2014-04-18

    Highlights: • Leptin and Ob-R are expressed in gastric adenoma and early and advanced cancer. • Leptin is more likely associated with differentiated gastric cancer or cardia cancer. • Leptin proliferates gastric cancer cells via activating the STAT3 and ERK1/2 pathways. - Abstract: Obesity is associated with certain types of cancer, including gastric cancer. However, it is still unclear whether obesity-related cytokine, leptin, is implicated in gastric cancer. Therefore, we aimed to investigate the role of leptin in gastric cancer. The expression of leptin and its receptor, Ob-R, was assessed by immunohistochemical staining and was compared in patients with gastric adenoma (n = 38), early gastric cancer (EGC) (n = 38), and advanced gastric cancer (AGC) (n = 38), as a function of their clinicopathological characteristics. Gastric cancer cell lines were studied to investigate the effects of leptin on the signal transducer and activator of transcription-3 (STAT3) and extracellular receptor kinase 1/2 (ERK1/2) signaling pathways using MTT assays, immunoblotting, and inhibition studies. Leptin was expressed in gastric adenomas (42.1%), EGCs (47.4%), and AGCs (43.4%). Ob-R expression tended to increase from gastric adenoma (2%), through EGC (8%), to AGC (18%). Leptin induced the proliferation of gastric cancer cells by activating STAT3 and ERK1/2 and up-regulating the expression of vascular endothelial growth factor (VEGF). Blocking Ob-R with pharmacological inhibitors and by RNAi decreased both the leptin-induced activation of STAT3 and ERK1/2 and the leptin-induced expression of VEGF. Leptin plays a role in gastric cancer by stimulating the proliferation of gastric cancer cells via activating the STAT3 and ERK1/2 pathways.

  19. The role of leptin in gastric cancer: Clinicopathologic features and molecular mechanisms

    International Nuclear Information System (INIS)

    Lee, Kang Nyeong; Choi, Ho Soon; Yang, Sun Young; Park, Hyun Ki; Lee, Young Yiul; Lee, Oh Young; Yoon, Byung Chul; Hahm, Joon Soo; Paik, Seung Sam

    2014-01-01

    Highlights: • Leptin and Ob-R are expressed in gastric adenoma and early and advanced cancer. • Leptin is more likely associated with differentiated gastric cancer or cardia cancer. • Leptin proliferates gastric cancer cells via activating the STAT3 and ERK1/2 pathways. - Abstract: Obesity is associated with certain types of cancer, including gastric cancer. However, it is still unclear whether obesity-related cytokine, leptin, is implicated in gastric cancer. Therefore, we aimed to investigate the role of leptin in gastric cancer. The expression of leptin and its receptor, Ob-R, was assessed by immunohistochemical staining and was compared in patients with gastric adenoma (n = 38), early gastric cancer (EGC) (n = 38), and advanced gastric cancer (AGC) (n = 38), as a function of their clinicopathological characteristics. Gastric cancer cell lines were studied to investigate the effects of leptin on the signal transducer and activator of transcription-3 (STAT3) and extracellular receptor kinase 1/2 (ERK1/2) signaling pathways using MTT assays, immunoblotting, and inhibition studies. Leptin was expressed in gastric adenomas (42.1%), EGCs (47.4%), and AGCs (43.4%). Ob-R expression tended to increase from gastric adenoma (2%), through EGC (8%), to AGC (18%). Leptin induced the proliferation of gastric cancer cells by activating STAT3 and ERK1/2 and up-regulating the expression of vascular endothelial growth factor (VEGF). Blocking Ob-R with pharmacological inhibitors and by RNAi decreased both the leptin-induced activation of STAT3 and ERK1/2 and the leptin-induced expression of VEGF. Leptin plays a role in gastric cancer by stimulating the proliferation of gastric cancer cells via activating the STAT3 and ERK1/2 pathways

  20. Adipokines, Oxidized Low-Density Lipoprotein, and C-Reactive Protein Levels in Lean, Overweight, and Obese Portuguese Patients with Type 2 Diabetes

    Science.gov (United States)

    Neuparth, Maria João; Proença, Jorge Brandão; Santos-Silva, Alice; Coimbra, Susana

    2013-01-01

    Aim. Our aim was to study how different BMI scores may influence the levels of inflammation, oxidative stress, adipogenesis, glucose, and lipid metabolism, in lean, overweight, and obese Portuguese patients with type 2 diabetes mellitus (T2DM). Methods. We studied 28 lean, 38 overweight, and 17 obese patients with T2DM and 20 controls (gender and age matched). The circulating levels of oxLDL, CRP, and some adipokines—adiponectin, leptin, and chemerin—and the lipid profile were evaluated. Results. Obese patients presented significantly lower levels of adiponectin and higher leptin, oxLDL, and chemerin levels, as compared to the overweight, lean, and control groups. Overweight, compared to lean and control, subjects showed significantly lower adiponectin and higher leptin and chemerin levels; oxLDL values were significantly higher in overweight than in lean patients. Lean patients presented significantly higher chemerin values than the control. Obese patients presented significantly higher CRP values, as compared to lean patients and the control group. Obese and overweight patients presented significantly higher triglycerides values than lean patients. Except for CRP, all the observed significant changes between control and patients remained significant after statistical adjustment for the body mass index (BMI). Conclusion. The levels of leptin, adiponectin, oxLDL, CRP, and triglycerides in patients with T2DM seem to be more associated with obesity and less with diabetes. Chemerin levels were raised in lean, overweight, and obese patients, suggesting that, independently of BMI, an adipocyte dysfunction occurs. Moreover, chemerin may provide an important early biomarker of adipocyte dysfunction and a link between obesity and type 2 diabetes mellitus. PMID:24634792

  1. Role of the Polymorphisms of Uncoupling Protein Genes in Childhood Obesity and Their Association with Obesity-Related Disturbances.

    Science.gov (United States)

    Gul, Ali; Ateş, Ömer; Özer, Samet; Kasap, Tuba; Ensari, Emel; Demir, Osman; Sönmezgöz, Ergün

    2017-09-01

    Obesity, one of the most common disorders observed in clinical practice, has been associated with energy metabolism-related protein genes such as uncoupling proteins (UCPs). Herein, we evaluated UCPs as candidate genes for obesity and its morbidities. A total of 268 obese and 185 nonobese children and adolescents were enrolled in this study. To determine dyslipidemia, hypertension, and insulin resistance, laboratory tests were derived from fasting blood samples. UCP1-3826 A/G, UCP2 exon 8 deletion/insertion (del/ins), and UCP3-55C/T variants were also genotyped, and the relationships among the polymorphisms of these UCPs and obesity morbidities were investigated. The mean ages of the obese and control groups were 11.61 ± 2.83 and 10.74 ± 3.36 years, respectively. The respective genotypic frequencies of the AA, AG, and GG genotypes of UCP1 were 46.3%, 33.2%, and 20.5% in obese subjects and 46.5%, 42.2%, and 11.4% in the controls (p = 0.020). G alleles were more frequent in obese subjects with hypertriglyceridemia (42.9%; p = 0.048) than in those without, and the GG genotype presented an odds ratio for obesity of 2.02 (1.17-3.47; p = 0.010). The polymorphisms of UCP2 exon 8 del/ins and UCP3-55C/T did not influence obesity risk (p > 0.05). The I (ins) allele was associated with low HDL cholesterolemia (p = 0.023). The GG genotype of the UCP1-3826 A/G polymorphism appears to contribute to the onset of childhood obesity in Turkish children. The GG genotype of UCP1, together with the del/del genotype of the UCP2 polymorphism, may increase the risk of obesity with synergistic effects. The ins allele of the UCP2 exon 8 del/ins polymorphism may contribute to low HDL cholesterolemia.

  2. Leptin controls hair follicle cycling.

    Science.gov (United States)

    Watabe, Reiko; Yamaguchi, Takashi; Kabashima-Kubo, Rieko; Yoshioka, Manabu; Nishio, Daisuke; Nakamura, Motonobu

    2014-04-01

    Leptin is a cytokine well known for its ability to control body weight and energy metabolism. Several lines of evidence have recently revealed that leptin also plays an important role in wound healing and immune modulation in skin. Sumikawa et al. Exp Dermatol 2014 evaluated the effect of leptin on hair follicle cycling using mutant and wild-type mice. They report that leptin is produced in dermal papilla cells in hair follicles and that leptin receptor-deficient db/db mice show an abnormality in hair follicle cycling. Moreover, leptin injection induced the transition into the growth stage of the hair cycle (anagen). On this basis, it now deserves exploration whether leptin-mediated signalling is a key stimulus for anagen induction and whether this may be targeted to manage human hair disorders with defect in the control of hair follicle cycling. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Integral Role of PTP1B in Adiponectin-Mediated Inhibition of Oncogenic Actions of Leptin in Breast Carcinogenesis

    OpenAIRE

    LaTonia Taliaferro-Smith; Arumugam Nagalingam; Brandi Brandon Knight; Elaine Oberlick; Neeraj K. Saxena; Dipali Sharma

    2013-01-01

    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 inh...

  4. Evidence that plasma leptin and insulin levels are associated with body adiposity via different mechanisms.

    Science.gov (United States)

    Schwartz, M W; Prigeon, R L; Kahn, S E; Nicolson, M; Moore, J; Morawiecki, A; Boyko, E J; Porte, D

    1997-09-01

    Like insulin, the adipocyte hormone, leptin, circulates at levels proportionate to body adiposity. Because insulin may regulate leptin secretion, we sought to determine if plasma leptin levels are coupled to body adiposity via changes in circulating insulin levels or insulin sensitivity and whether leptin secretion from adipocytes is impaired in subjects with NIDDM. We used multiple linear regression to analyze relationships between BMI (a measure of body adiposity) and fasting plasma levels of leptin and insulin in 98 nondiabetic human subjects (68 men/30 women) and 38 subjects with NIDDM (27 men/11 women). The insulin sensitivity index (Si) was also determined in a subset of nondiabetic subjects (n = 38). Fasting plasma leptin concentrations were correlated to both BMI (r = 0.66, P = 0.0001) and fasting plasma insulin levels (r = 0.65, P = 0.0001) in nondiabetic men and women (r = 0.58, P = 0.0009 for BMI; r = 0.47, P = 0.01 for insulin). While the plasma leptin level was also inversely related to Si (r = -0.35; P = 0.03), this association was dependent on BMI, whereas the association between insulin and Si was not. Conversely, the relationship between plasma leptin and BMI was independent of Si, whereas that between insulin and BMI was dependent on Si. The relationship between plasma leptin levels and BMI did not differ significantly among NIDDM subjects from that observed in nondiabetic subjects. We conclude that 1) body adiposity, sex, and the fasting insulin level are independently associated with plasma leptin level; 2) because NIDDM does not influence leptin levels, obesity associated with NIDDM is unlikely to result from impaired leptin secretion; and 3) insulin sensitivity contributes to the association between body adiposity and plasma levels of insulin, but not leptin. The mechanisms underlying the association between body adiposity and circulating levels of these two hormones, therefore, appear to be different.

  5. Dietary Protein in the Prevention of Diet-Induced Obesity and Co-Morbidities

    DEFF Research Database (Denmark)

    Tastesen, Hanne Sørup

    Background: Obesity and related co‐morbidities are increasing problems worldwide and nutritional approaches to prevent and alleviate these diseases are thus of great interest. High‐protein diets have been shown to prevent and alleviate obesity and co‐morbidities in rodents and humans through...... protein, was found to be negligible in development of obesity and co‐morbidities in mice. Seafood protein with high endogenous taurine and glycine contents was found to prevent diet‐induced adiposity and dyslipidemia, both in ad libitum and pair‐fed settings. The ability of seafood proteins to prevent...... these metabolic disturbances was found to associate with the high endogenous taurine and glycine concentrations and to concur with increased energy expenditure and a tendency towards increased voluntary locomotor activity. Consumption of a seafood protein‐mixture prevented diet‐induced development of obesity...

  6. Polychlorinated biphenyls (PCB 101, PCB 153 and PCB 180) alter leptin signaling and lipid metabolism in differentiated 3T3-L1 adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Ferrante, Maria C. [Department of Veterinary Medicine and Animal Productions, Federico II University of Naples, Via Delpino 1, 80137 Naples (Italy); Amero, Paola; Santoro, Anna [Department of Pharmacy, Federico II University of Naples, Via Montesano 49, 80131 Naples (Italy); Monnolo, Anna [Department of Veterinary Medicine and Animal Productions, Federico II University of Naples, Via Delpino 1, 80137 Naples (Italy); Simeoli, Raffaele; Di Guida, Francesca [Department of Pharmacy, Federico II University of Naples, Via Montesano 49, 80131 Naples (Italy); Mattace Raso, Giuseppina, E-mail: mattace@unina.it [Department of Pharmacy, Federico II University of Naples, Via Montesano 49, 80131 Naples (Italy); Meli, Rosaria, E-mail: meli@unina.it [Department of Pharmacy, Federico II University of Naples, Via Montesano 49, 80131 Naples (Italy)

    2014-09-15

    Non-dioxin-like polychlorinated biphenyls (NDL-PCBs) are highly lipophilic environmental contaminants that accumulate in lipid-rich tissues, such as adipose tissue. Here, we reported the effects induced by PCBs 101, 153 and 180, three of the six NDL-PCBs defined as indicators, on mature 3T3-L1 adipocytes. We observed an increase in lipid content, in leptin gene expression and a reduction of leptin receptor expression and signaling, when cells were exposed to PCBs, alone or in combination. These modifications were consistent with the occurrence of “leptin-resistance” in adipose tissue, a typical metabolic alteration related to obesity. Therefore, we investigated how PCBs affect the expression of pivotal proteins involved in the signaling of leptin receptor. We evaluated the PCB effect on the intracellular pathway JAK/STAT, determining the phosphorylation of STAT3, a downstream activator of the transcription of leptin gene targets, and the expression of SOCS3 and PTP1B, two important regulators of leptin resistance. In particular, PCBs 153 and 180 or all PCB combinations induced a significant reduction in pSTAT3/STAT3 ratio and an increase in PTP1B and SOCS3, evidencing an additive effect. The impairment of leptin signaling was associated with the reduction of AMPK/ACC pathway activation, leading to the increase in lipid content. These pollutants were also able to increase the transcription of inflammatory cytokines (IL-6 and TNFα). It is worthy to note that the PCB concentrations used are comparable to levels detectable in human adipose tissue. Our data strongly support the hypothesis that NDL-PCBs may interfere with the lipid metabolism contributing to the development of obesity and related diseases. - Highlights: • NDL-PCBs alter lipid content and metabolism in 3T3-L1 adipocytes. • Impairment of leptin signaling was induced by NDL-PCBs. • NDL-PCBs reduce AMPK and ACC activation. • NDL-PCBs induce the synthesis of pro-inflammatory cytokine by

  7. Polychlorinated biphenyls (PCB 101, PCB 153 and PCB 180) alter leptin signaling and lipid metabolism in differentiated 3T3-L1 adipocytes

    International Nuclear Information System (INIS)

    Ferrante, Maria C.; Amero, Paola; Santoro, Anna; Monnolo, Anna; Simeoli, Raffaele; Di Guida, Francesca; Mattace Raso, Giuseppina; Meli, Rosaria

    2014-01-01

    Non-dioxin-like polychlorinated biphenyls (NDL-PCBs) are highly lipophilic environmental contaminants that accumulate in lipid-rich tissues, such as adipose tissue. Here, we reported the effects induced by PCBs 101, 153 and 180, three of the six NDL-PCBs defined as indicators, on mature 3T3-L1 adipocytes. We observed an increase in lipid content, in leptin gene expression and a reduction of leptin receptor expression and signaling, when cells were exposed to PCBs, alone or in combination. These modifications were consistent with the occurrence of “leptin-resistance” in adipose tissue, a typical metabolic alteration related to obesity. Therefore, we investigated how PCBs affect the expression of pivotal proteins involved in the signaling of leptin receptor. We evaluated the PCB effect on the intracellular pathway JAK/STAT, determining the phosphorylation of STAT3, a downstream activator of the transcription of leptin gene targets, and the expression of SOCS3 and PTP1B, two important regulators of leptin resistance. In particular, PCBs 153 and 180 or all PCB combinations induced a significant reduction in pSTAT3/STAT3 ratio and an increase in PTP1B and SOCS3, evidencing an additive effect. The impairment of leptin signaling was associated with the reduction of AMPK/ACC pathway activation, leading to the increase in lipid content. These pollutants were also able to increase the transcription of inflammatory cytokines (IL-6 and TNFα). It is worthy to note that the PCB concentrations used are comparable to levels detectable in human adipose tissue. Our data strongly support the hypothesis that NDL-PCBs may interfere with the lipid metabolism contributing to the development of obesity and related diseases. - Highlights: • NDL-PCBs alter lipid content and metabolism in 3T3-L1 adipocytes. • Impairment of leptin signaling was induced by NDL-PCBs. • NDL-PCBs reduce AMPK and ACC activation. • NDL-PCBs induce the synthesis of pro-inflammatory cytokine by

  8. Dissociated incretin hormone response to protein versus fat ingestion in obese subjects

    DEFF Research Database (Denmark)

    Lindgren, O; Carr, RD; Holst, Jens Juul

    2011-01-01

    kcal/kg) fat (olive oil) or protein (whey protein) was ingested by non-diabetic obese male volunteers [body mass index (BMI) >30 kg/m(2) ; n = 12] and plasma GIP and GLP-1 were determined. We found no difference in the early GIP or GLP-1 responses to fat versus protein. However, the total 300-min GIP...

  9. C-reactive protein and cardiometabolic risk factors in overweight or obese children and adolescents

    OpenAIRE

    Cardoso, Anajás da Silva; Cardoso, Renata Oliveira; Carvalho, Danielle Franklin de; Collet, Neusa; Medeiros, Carla Campos Muniz

    2014-01-01

    OBJECTIVE: To investigate the relationship between ultrasensitive C-reactive protein and cardiometabolic risk factors in overweight or obese childrenand adolescents. METHODS: Cross-sectional study conducted at the Center for Childhood Obesity in the period from April 2009 to April 2010, involving 185 overweight children and adolescents aged 2 to 18 years. Measures of ultrasensitive C-reactive protein according to age, nutritional status, gender, race, cardiometabolic risk factors (waist ...

  10. Longitudinal study of leptin levels in chronic hemodialysis patients

    Directory of Open Access Journals (Sweden)

    Averbukh Zhan

    2011-06-01

    Full Text Available Abstract Background The influence of serum leptin levels on nutritional status and survival in chronic hemodialysis patients remained to be elucidated. We conducted a prospective longitudinal study of leptin levels and nutritional parameters to determine whether changes of serum leptin levels modify nutritional status and survival in a cohort of prevalent hemodialysis patients. Methods Leptin, dietary energy and protein intake, biochemical markers of nutrition and body composition (anthropometry and bioimpedance analysis were measured at baseline and at 6, 12, 18 and 24 months following enrollment, in 101 prevalent hemodialysis patients (37% women with a mean age of 64.6 ± 11.5 years. Observation of this cohort was continued over 2 additional years. Changes in repeated measures were evaluated, with adjustment for baseline differences in demographic and clinical parameters. Results Significant reduction of leptin levels with time were observed (linear estimate: -2.5010 ± 0.57 ng/ml/2y; p Conclusions Thus leptin levels reflect fat mass depots, rather than independently contributing to uremic anorexia or modifying nutritional status and/or survival in chronic hemodialysis patients. The importance of such information is high if leptin is contemplated as a potential therapeutic target in hemodialysis patients.

  11. The correlation between hs C-reactive protein and left ventricular mass in obese women

    Directory of Open Access Journals (Sweden)

    Idrus Alwi

    2006-06-01

    Full Text Available Plasma C-reactive protein (CRP concentrations are increased in obese individuals. In this study, we examined the correlation between hsCRP and left ventricular mass (LV mass. Fourty five healthy obese women and fourty five healthy non obese women as the controls group were studied by echocardiography and hsCRP. There was no significant correlation between hsCRP and left ventricular mass in obese women (r = 0.29, p 0.06. There was a significant correlation between hs CRP and body mass index (r = 0.46, p 0,002, and also hsCRP and visceral fat (r= 0.33, p 0.03. (Med J Indones 2006; 15:100-4 Keywords: hs C-reactive protein, LV mass, obese women

  12. RELATIONSHIP OF ADIPOKINES AND PROINFLAMMATORY CYTOKINES AMONG ASIAN INDIANS WITH OBESITY AND YOUTH ONSET TYPE 2 DIABETES.

    Science.gov (United States)

    Gokulakrishnan, Kuppan; Amutha, Anandakumar; Ranjani, Harish; Bibin, Subramanian Y; Balakumar, Mahalingam; Pandey, Gautam Kumar; Anjana, Ranjit Mohan; Ali, Mohammed K; Narayan, K M Venkat; Mohan, Viswanathan

    2015-10-01

    It is well known that inflammation is associated with diabetes, but it is unclear whether obesity mediates this association in individuals with youth-onset type 2 diabetes mellitus (T2DM-Y). We recruited individuals with T2DM-Y (age at onset obesity and categorized as: nonobese NGT (n = 100), Obese NGT (n = 50), nonobese T2DM-Y (n = 50), and obese T2DM-Y (n = 50). We compared adipokines (adiponectin and leptin) and proinflammatory cytokines (tumor necrosis factor alpha [TNF-α] and monocyte chemotactic protein-1 [MCP-1]) across groups. Compared to nonobese NGT, the other 3 groups (obese NGT, nonobese T2DM-Y, and obese T2DM-Y) were found to have lower adiponectin (7.7 vs. 5.7, 4.2, 3.8 μg/mL, Pobese T2DM-Y (141 pg/mL, Pobese T2DM, respectively. However, adjusted for same factors, leptin, TNF-α, and MCP-1 were associated with markedly higher odds (5- to 14-fold) of nonobese and obese T2DM. In young Asian Indians, leptin and proinflammatory cytokines are positively, and adiponectin negatively, associated with both nonobese and obese T2DM-Y compared to nonobese NGT individuals.

  13. Energy budget, behavior and leptin in striped hamsters subjected to food restriction and refeeding.

    Directory of Open Access Journals (Sweden)

    Zhi-Jun Zhao

    Full Text Available Food restriction induces a loss of body mass that is often followed by rapid regaining of the lost weight when the restriction ends, consequently increasing a risk of development of obesity. To determine the physiological and behavioral mechanisms underlining the regaining, striped hamsters were restricted to 85% of initial food intake for 4 weeks and refed ad libitum for another 4 weeks. Changes in body mass, energy budget, activity, body composition and serum leptin level were measured. Body mass, body fat mass and serum leptin level significantly decreased in food-restricted hamsters, and increased when the restriction ended, showing a short "compensatory growth" rather than over-weight or obesity compared with ad libitum controls. During restriction, the time spent on activity increased significantly, which was opposite to the changes in serum leptin level. Food intake increased shortly during refeeding, which perhaps contributed to the rapid regaining of body mass. No correlation was observed between serum leptin and energy intake, while negative correlations were found in hamsters that were refed for 7 and 28 days. Exogenous leptin significantly decreased the time spent on activity during food restriction and attenuated the increase in food intake during refeeding. This suggests that low leptin in restricted animals may function as a starvation signal to induce an increase in activity behavior, and high leptin likely serves as a satiety signal to prevent activity during refeeding. Leptin may play a crucial role in controlling food intake when the restriction ends, and consequently preventing overweight.

  14. Leptin induces CYP1B1 expression in MCF-7 cells through ligand-independent activation of the ERα pathway

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    Khanal, Tilak; Kim, Hyung Gyun; Do, Minh Truong; Choi, Jae Ho; Won, Seong Su [Department of Toxicology, College of Pharmacy, Chungnam National University, Daejeon (Korea, Republic of); Kang, Wonku [College of Pharmacy, Yeungnam University, Gyeongsan (Korea, Republic of); Chung, Young Chul [Department of Food Science and Culinary, International University of Korea, Jinju (Korea, Republic of); Jeong, Tae Cheon, E-mail: taecheon@ynu.ac.kr [College of Pharmacy, Yeungnam University, Gyeongsan (Korea, Republic of); Jeong, Hye Gwang, E-mail: hgjeong@cnu.ac.kr [Department of Toxicology, College of Pharmacy, Chungnam National University, Daejeon (Korea, Republic of)

    2014-05-15

    Leptin, a hormone with multiple biological actions, is produced predominantly by adipose tissue. Among its functions, leptin can stimulate tumour cell growth. Oestrogen receptor α (ERα), which plays an essential role in breast cancer development, can be transcriptionally activated in a ligand-independent manner. In this study, we investigated the effect of leptin on CYP1B1 expression and its mechanism in breast cancer cells. Leptin induced CYP1B1 protein, messenger RNA expression and promoter activity in ERα-positive MCF-7 cells but not in ERα-negative MDA-MB-231 cells. Additionally, leptin increased 4-hydroxyoestradiol in MCF-7 cells. Also, ERα knockdown by siRNA significantly blocked the induction of CYP1B1 expression by leptin, indicating that leptin induced CYP1B1 expression via an ERα-dependent mechanism. Transient transfection with CYP1B1 deletion promoter constructs revealed that the oestrogen response element (ERE) plays important role in the up-regulation of CYP1B1 by leptin. Furthermore, leptin stimulated phosphorylation of ERα at serine residues 118 and 167 and increased ERE-luciferase activity, indicating that leptin induced CYP1B1 expression by ERα activation. Finally, we found that leptin activated ERK and Akt signalling pathways, which are upstream kinases related to ERα phosphorylation induced by leptin. Taken together, our results indicate that leptin-induced CYP1B1 expression is mediated by ligand-independent activation of the ERα pathway as a result of the activation of ERK and Akt in MCF-7 cells. - Highlights: • Leptin increased 4-hydroxyoestradiol in MCF-7 breast cancer cells. • Leptin activated ERK and Akt kinases related to ERα phosphorylation. • Leptin induces phosphorylation of ERα at serine residues 118 and 167. • Leptin induces ERE-luciferase activity.

  15. Leptin Antagonizes Peroxisome Proliferator-Activated Receptor-γ Signaling in Growth Plate Chondrocytes

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    Lai Wang

    2012-01-01

    Full Text Available Leptin is an obesity-associated cytokine-like hormone encoded by the ob gene. Recent studies reveal that leptin promotes proliferation and differentiation of chondrocytes, suggesting a peripheral role of leptin in regulating growth plate function. Peroxisome proliferator-activated receptor-γ (PPARγ is a transcriptional regulator of adipogenesis. Locally, PPARγ negatively regulates chondrogenic differentiation and terminal differentiation in the growth plate. The aim of this study was to test the hypothesis that leptin may suppress the inhibitory effects of PPARγ on growth plate chondrocytes. Chondrocytes were collected from distal femoral growth plates of newborn rats and were cultured in monolayer or cell pellets in the presence or absence of leptin and the PPARγ agonist ciglitazone. The results show that leptin attenuates the suppressive effects of PPARγ on chondrogenic differentiation and T3-mediated chondrocyte hypertrophy. Leptin treatment also leads to a mild downregulation of PPAR mRNA expression and a significant MAPK/ERK-dependent PPARγ phosphorylation at serine 112/82. Blocking MAPK/ERK function with PD98059 confirmed that leptin antagonizes PPARγ function in growth plate chondrocytes through the MAPK/ERK signaling pathway. Furthermore, leptin signaling in growth plate cells is also negatively modulated by activation of PPARγ, implying that these two signaling pathways are mutually regulated in growth plate chondrocytes.

  16. Human breast milk and adipokines--A potential role for the soluble leptin receptor (sOb-R) in the regulation of infant energy intake and development.

    Science.gov (United States)

    Zepf, F D; Rao, P; Moore, J; Stewart, R; Ladino, Yuli Martinez; Hartmann, B T

    2016-01-01

    Concentrations of different adipokines in human breast milk are thought to be able to affect energy intake of the infant. Leptin is a hormone synthesized by adipose tissue and the human placenta and favors satiety. The availability of leptin in breast milk is influenced by epithelial cells of the mammary gland that are known to be able to produce leptin, as well as leptin from maternal circulation that is transported to the breast milk, and which can thus in turn reach neonatal blood after absorption. Research so far as mainly focused on leptin concentrations in breast milk. However, evidence suggests that in addition to leptin concentrations levels of the so-called soluble leptin receptor (sOb-R), the main high-affinity binding protein for leptin in humans, are necessary in order to calculate the free leptin index (FLI) and to assess function of the leptin axis. FLI is calculated from the ratio of leptin to the sOb-R, and serves as the main parameter for assessing function of the leptin axis throughout maturation and development. Here we propose that assessing sOb-R levels in addition to leptin concentrations in breast milk could serve as a valuable tool to investigate effects of the leptin axis in breast milk because sOb-R concentrations can impact available leptin levels, and which in turn can have significant implications for infant energy intake and related development. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Development of a radioimmunoassay for the measurement of human leptin in serum

    International Nuclear Information System (INIS)

    Lagarde, A. R.; Nagy, K.; Forgach, T.; Janoki, G. A.

    2003-01-01

    Leptin is a 16 kDa polypeptide hormone encoded by the obese gene (ob) and secreted by adipose tissue. This hormone plays a major role in energy homeostasis and regulation of food intake and body weight. It also affects the metabolic, neuroendocrine and reproductive systems. Labelling of recombinant human leptin with 125I was best performed by the Chloramine-T method. New Zealand white rabbits were immunised with recombinant human leptin, cross-reaction of obtained antisera was analyzed with 10 different antigens. The separation of bound and free fractions was performed using the second antibody - PEG method. The obtained tracer had specific activities of 2.8-3.3 kBq/μg and had a stability of 5 weeks. A highly specific polyclonal antibody was obtained without measurable cross-reaction against the analysed antigens. Concentrations of human leptin were measured by a single overnight incubation assay with a sensitivity of 0.5 ng/ml and a measuring range of 0.5-100 ng/ml. The intra-assay and inter-assay coefficient of variation was under 6% and 8%, respectively. Recovery ranged from 88% to 106%. Serum human leptin concentrations can be accurately and precisely measured by this new radioimmunoassay. Preliminary results obtained from the measurement of serum leptin in lean, overweight and obese patients are presented. Serum leptin concentrations correlated with body mass index and were significantly higher in women than in men, except for obese patients. (author)

  18. Differential representation of liver proteins in obese human subjects suggests novel biomarkers and promising targets for drug development in obesity.

    Science.gov (United States)

    Caira, Simonetta; Iannelli, Antonio; Sciarrillo, Rosaria; Picariello, Gianluca; Renzone, Giovanni; Scaloni, Andrea; Addeo, Pietro

    2017-12-01

    The proteome of liver biopsies from human obese (O) subjects has been compared to those of nonobese (NO) subjects using two-dimensional gel electrophoresis (2-DE). Differentially represented proteins were identified by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS)-based peptide mass fingerprinting (PMF) and nanoflow-liquid chromatography coupled to electrospray-tandem mass spectrometry (nLC-ESI-MS/MS). Overall, 61 gene products common to all of the liver biopsies were identified within 65 spots, among which 25 ones were differently represented between O and NO subjects. In particular, over-representation of short-chain acyl-CoA dehydrogenase, Δ(3,5)-Δ(2,4)dienoyl-CoA isomerase, acetyl-CoA acetyltransferase, glyoxylate reductase/hydroxypyruvate reductase, fructose-biphosphate aldolase B, peroxiredoxin I, protein DJ-1, catalase, α- and β-hemoglobin subunits, 3-mercaptopyruvate S-transferase, calreticulin, aminoacylase 1, phenazine biosynthesis-like domain-containing protein and a form of fatty acid-binding protein, together with downrepresentation of glutamate dehydrogenase, glutathione S-transferase A1, S-adenosylmethionine synthase 1A and a form of apolipoprotein A-I, was associated with the obesity condition. Some of these metabolic enzymes and antioxidant proteins have already been identified as putative diagnostic markers of liver dysfunction in animal models of steatosis or obesity, suggesting additional investigations on their role in these syndromes. Their differential representation in human liver was suggestive of their consideration as obesity human biomarkers and for the development of novel antiobesity drugs.

  19. Leptin increases skeletal muscle lipoprotein lipase and postprandial lipid metabolism in mice.

    Science.gov (United States)

    Donahoo, William T; Stob, Nicole R; Ammon, Stefen; Levin, Nancy; Eckel, Robert H

    2011-03-01

    The ability of leptin to preserve lean tissue during weight loss may be in part due to differences in nutrient partitioning. Because lipoprotein lipase (LPL) plays a key role in partitioning lipid nutrients, this study was conducted to test the hypothesis that leptin would modify the tissue-specific regulation of LPL and result in increased lipid oxidation and decreased storage. The effects of daily intraperitoneal leptin injections (2 mg/kg body weight) over 2 weeks on LPL activity and postprandial lipid metabolism were tested in both wild-type (WT), leptin-deficient ob/ob obese mice and mice pair fed to the leptin-treated mice. On the experimental day, mice were given food by gavage, blood was drawn periodically, and adipose tissue and skeletal muscle were harvested for measurements of LPL activity at 240 minutes. After 2 weeks of leptin administration, skeletal muscle LPL (SMLPL) activity was increased in leptin-treated compared with pair-fed (P = .012) and WT (P = .002) mice. There was no effect of leptin or pair feeding on postprandial adipose tissue LPL activity. In ob/ob mice, leptin treatment normalized the decrease in postprandial free fatty acid concentration (P = .066). Leptin had no effect on either the area under the triglyceride (TG) excursion or the integrated area under the TG excursion in WT mice. In ob/ob mice, however, the TG excursion was lower in the leptin-treated than the pair-fed mice by area under the TG excursion (P = .012) and was lower than in the WT mice by integrated area under the TG excursion (P = .027). As expected, 2 weeks of leptin treatment decreased body weight in both the WT and ob/ob mice (-2.6% and -10.4%, respectively). Leptin treatment increased SMLPL, an effect that may have contributed to the leptin-induced weight loss. The leptin-induced decreased postprandial TG excursion in ob/ob mice suggests that leptin acts to augment clearance of postprandial TG-rich lipoprotein lipid and that this increase may in part be secondary

  20. MOLECULAR CLONING OF OVINE cDNA LEPTIN GENE

    Directory of Open Access Journals (Sweden)

    CLAUDIA TEREZIA SOCOL

    2008-05-01

    Full Text Available An efficient bacterial transformation system suitable for cloning the coding sequence of the ovine leptin gene in E. coli DH5α host cells using the pGEMT easy vector it is described in this paper. The necessity of producing leptin is based on the fact that the role of this molecule in the animal and human organism is still unknown, leptin not existing as commercial product on the Romanian market. The results obtained in the bacterial transformation, cloning, recombinant clones selection, control of the insertion experiments and DNA computational analysis represent the first steps in further genetic engineering experiments such as production of DNA libraries, DNA sequencing, protein expression, etc., for a further contribution in elucidating the role of leptin in the animal and human organism.

  1. Phospholipase C-related catalytically inactive protein can regulate obesity, a state of peripheral inflammation

    Directory of Open Access Journals (Sweden)

    Yosuke Yamawaki

    2017-02-01

    Full Text Available Obesity is defined as abnormal or excessive fat accumulation. Chronic inflammation in fat influences the development of obesity-related diseases. Many reports state that obesity increases the risk of morbidity in many diseases, including hypertension, dyslipidemia, type 2 diabetes, coronary heart disease, stroke, sleep apnea, and breast, prostate and colon cancers, leading to increased mortality. Obesity is also associated with chronic neuropathologic conditions such as depression and Alzheimer's disease. However, there is strong evidence that weight loss reduces these risks, by limiting blood pressure and improving levels of serum triglycerides, total cholesterol, low-density lipoprotein (LDL-cholesterol, and high-density lipoprotein (HDL-cholesterol. Prevention and control of obesity is complex, and requires a multifaceted approach. The elucidation of molecular mechanisms driving fat metabolism (adipogenesis and lipolysis aims at developing clinical treatments to control obesity. We recently reported a new regulatory mechanism in fat metabolism: a protein phosphatase binding protein, phospholipase C-related catalytically inactive protein (PRIP, regulates lipolysis in white adipocytes and heat production in brown adipocytes via phosphoregulation. Deficiency of PRIP in mice led to reduced fat accumulation and increased energy expenditure, resulting in a lean phenotype. Here, we evaluate PRIP as a new therapeutic target for the control of obesity.

  2. Hantaran Sinyal Leptin dan Obesitas: Hubungannya dengan Penyakit Kardiovaskuler

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    David Limanan

    2013-11-01

    Full Text Available Diperkirakan saat ini jumlah orang dengan obesitas melebihi 250 juta orang, yaitu 7% dari populasi orang dewasa di dunia. Mortalitas obesitas erat hubungannya dengan sindrom metabolik yang merupakan kelainan metabolik meliputi obesitas, resistensi insulin, gangguan toleransi glukosa, abnormalitas trigliserida dan hemostasis, disfungsi endotel dan hipertensi. Leptin dihasilkan adiposit dan merupakan anggota dari adipositokin; berperan dalam hantaran sinyal hormon jaringan adiposa. Kelainan leptin maupun reseptornyadapat menyebabkan seseorang mengalami obesitas, metabolik sindrom, diabetes dan penyakit kardiovaskuler. Kompleks leptin-reseptor mengaktifkan sistem transduksi sinyal, yang paling dominan adalah jalur janus kinase-signal transducer and activator of transcription-3 (JAK-STAT3, kemudian phospatidyl inositol 3- kinase (PI3K, mitogen-activated protein kinase (MAPK, 5’adenosine monophosphate-activated protein kinase (AMPK, dan mammalian target of rapamycin (mTOR. Jalur leptin-associated PI3K dengan ERK cascade berperan penting dalam proliferasi kardiomiosit dan melindungi jantung dari ischemia reperfusion injury. ERK1/2 mengaktifkan target gen seperti c-fos dan egr-1 yang berperan dalam proliferasi dan diferensiasi. Nuclear factor κB diduga sebagai target jalur p38 dan JNK MAPK. Faktor transkripsi inu berperan pentingdalam mengatur transkripsi sitokin proinflamasi seperti tumor necrosis factor (TNF-α dan interleukin (IL-1β. Leptin dapat meningkatkan pembentukan reactive oxygen species (ROS sel endotel pembuluh darah dan menstimulasi sekresi TNF-α dan IL-6 yang merupakan promotor hipertensi dan aterosklerosis.Kata Kunci: obesitas, leptin, sistem kardiovaskuler 

  3. Relationship between Acute Phase Proteins and Serum Fatty Acid Composition in Morbidly Obese Patients

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    Ricardo Fernandes

    2013-01-01

    Full Text Available Background. Obesity is considered a low-grade inflammatory state and has been associated with increased acute phase proteins as well as changes in serum fatty acids. Few studies have assessed associations between acute phase proteins and serum fatty acids in morbidly obese patients. Objective. To investigate the relationship between acute phase proteins (C-Reactive Protein, Orosomucoid, and Albumin and serum fatty acids in morbidly obese patients. Methods. Twenty-two morbidly obese patients were enrolled in this study. Biochemical and clinical data were obtained before bariatric surgery, and fatty acids measured in preoperative serum. Results. Orosomucoid was negatively correlated with lauric acid (P=0.027 and eicosapentaenoic acid (EPA (P=0.037 and positively with arachidonic acid (AA (P=0.035, AA/EPA ratio (P=0.005, and n-6/n-3 polyunsaturated fatty acids ratio (P=0.035. C-Reactive Protein (CRP was negatively correlated with lauric acid (P=0.048, and both CRP and CRP/Albumin ratio were negatively correlated with margaric acid (P=0.010, P=0.008, resp.. Albumin was positively correlated with EPA (P=0.027 and margaric acid (P=0.008. Other correlations were not statistically significant. Conclusion. Our findings suggest that serum fatty acids are linked to acute phase proteins in morbidly obese patients.

  4. Modulation of sweet taste sensitivities by endogenous leptin and endocannabinoids in mice.

    Science.gov (United States)

    Niki, Mayu; Jyotaki, Masafumi; Yoshida, Ryusuke; Yasumatsu, Keiko; Shigemura, Noriatsu; DiPatrizio, Nicholas V; Piomelli, Daniele; Ninomiya, Yuzo

    2015-06-01

    Potential roles of endogenous leptin and endocannabinoids in sweet taste were examined by using pharmacological antagonists and mouse models including leptin receptor deficient (db/db) and diet-induced obese (DIO) mice. Chorda tympani (CT) nerve responses of lean mice to sweet compounds were increased after administration of leptin antagonist (LA) but not affected by administration of cannabinoid receptor antagonist (AM251). db/db mice showed clear suppression of CT responses to sweet compounds after AM251, increased endocannabinoid levels in the taste organ, and enhanced expression of a biosynthesizing enzyme of endocannabinoids in taste cells. The effect of LA was gradually decreased and that of AM251 was increased during the course of obesity in DIO mice. These findings suggest that circulating leptin, but not local endocannabinoids, is a dominant modulator for sweet taste in lean mice and endocannabinoids become more effective modulators of sweet taste under conditions of deficient leptin signalling. Leptin is an anorexigenic mediator that reduces food intake by acting on hypothalamic receptor Ob-Rb. In contrast, endocannabinoids are orexigenic mediators that act via cannabinoid CB1 receptors in hypothalamus, limbic forebrain, and brainstem. In the peripheral taste system, leptin administration selectively inhibits behavioural, taste nerve and taste cell responses to sweet compounds. Opposing the action of leptin, endocannabinoids enhance sweet taste responses. However, potential roles of endogenous leptin and endocannabinoids in sweet taste remain unclear. Here, we used pharmacological antagonists (Ob-Rb: L39A/D40A/F41A (LA), CB1 : AM251) and examined the effects of their blocking activation of endogenous leptin and endocannabinoid signalling on taste responses in lean control, leptin receptor deficient db/db, and diet-induced obese (DIO) mice. Lean mice exhibited significant increases in chorda tympani (CT) nerve responses to sweet compounds after LA

  5. Acute differential effects of dietary protein quality on postprandial lipemia in obese non-diabetic subjects

    DEFF Research Database (Denmark)

    Holmer-Jensen, Jens; Mortensen, Lene S; Astrup, Arne

    2013-01-01

    Non-fasting triglyceridemia is much closer associated to cardiovascular risk compared to fasting triglyceridemia. We hypothesized that there would be acute differential effects of four common dietary proteins (cod protein, whey isolate, gluten, and casein) on postprandial lipemia in obese non......-diabetic subjects. To test the hypothesis we conducted a randomized, acute clinical intervention study with crossover design. We supplemented a fat rich mixed meal with one of four dietary proteins i.e. cod protein, whey protein, gluten or casein. Eleven obese non-diabetic subjects (age: 40-68, body mass index: 30.......3-42.0 kg/m(2)) participated and blood samples were drawn in the 8-h postprandial period. Supplementation of a fat rich mixed meal with whey protein caused lower postprandial lipemia (P = .048) compared to supplementation with cod protein and gluten. This was primarily due to lower triglyceride...

  6. Carbonylated plasma proteins as potential biomarkers of obesity induced type 2 diabetes mellitus.

    Science.gov (United States)

    Bollineni, Ravi Chand; Fedorova, Maria; Blüher, Matthias; Hoffmann, Ralf

    2014-11-07

    Protein carbonylation is a common nonenzymatic oxidative post-translational modification, which is often considered as biomarker of oxidative stress. Recent evidence links protein carbonylation also to obesity and type 2 diabetes mellitus (T2DM), though the protein targets of carbonylation in human plasma have not been identified. In this study, we profiled carbonylated proteins in plasma samples obtained from lean individuals and obese patients with or without T2DM. The plasma samples were digested with trypsin, carbonyl groups were derivatized with O-(biotinylcarbazoylmethyl)hydroxylamine, enriched by avidin affinity chromatography, and analyzed by RPC-MS/MS. Signals of potentially modified peptides were targeted in a second LC-MS/MS analysis to retrieve the peptide sequence and the modified residues. A total of 158 unique carbonylated proteins were identified, of which 52 were detected in plasma samples of all three groups. Interestingly, 36 carbonylated proteins were detected only in obese patients with T2DM, whereas 18 were detected in both nondiabetic groups. The carbonylated proteins originated mostly from liver, plasma, platelet, and endothelium. Functionally, they were mainly involved in cell adhesion, signaling, angiogenesis, and cytoskeletal remodeling. Among the identified carbonylated proteins were several candidates, such as VEGFR-2, MMP-1, argin, MKK4, and compliment C5, already connected before to diabetes, obesity and metabolic diseases.

  7. Obesity

    Science.gov (United States)

    Obesity means having too much body fat. It is different from being overweight, which means weighing too ... what's considered healthy for his or her height. Obesity happens over time when you eat more calories ...

  8. Serum adiponectin levels are inversely associated with overall and central fat distribution but are not directly regulated by acute fasting or leptin administration in humans: cross-sectional and interventional studies.

    Science.gov (United States)

    Gavrila, Alina; Chan, Jean L; Yiannakouris, Nikos; Kontogianni, Meropi; Miller, Lisa C; Orlova, Christine; Mantzoros, Christos S

    2003-10-01

    Adiponectin is an adipocyte-secreted protein that circulates in high concentrations in the serum and acts to increase insulin sensitivity. Previous studies have shown that serum adiponectin is inversely associated with fat mass and insulin resistance in humans and that acute fasting decreases adipose tissue adiponectin mRNA expression in rodents. Whether acute energy deprivation, body fat distribution, or serum hormone levels are associated with circulating adiponectin in humans remains largely unknown. To identify predictors of serum adiponectin levels, we evaluated the association of adiponectin with several anthropometric, metabolic, and hormonal variables in a cross-sectional study of 121 women without a known history of diabetes. We also performed interventional studies to assess whether fasting for 48 h and/or leptin administration regulates serum adiponectin in healthy men and women. Our cross-sectional study shows that, in addition to overall obesity, central fat distribution is an independent negative predictor of serum adiponectin and suggests that adiponectin may represent a link between central obesity and insulin resistance. In addition, estradiol is negatively and independently associated with adiponectin, whereas there is no association between serum adiponectin and leptin, cortisol, or free testosterone levels. Our interventional studies demonstrate that neither fasting for 48 h, resulting in a low leptin state, nor leptin administration at physiological or pharmacological doses alters serum adiponectin levels. Further studies are needed to fully elucidate the physiology of adiponectin in humans and its role in the pathogenesis of insulin-resistant states.

  9. Leptin but not ciliary neurotrophic factor (CNTF) induces phosphotyrosine phosphatase-1B expression in human neuronal cells (SH-SY5Y): putative explanation of CNTF efficacy in leptin-resistant state.

    Science.gov (United States)

    Benomar, Yacir; Berthou, Flavien; Vacher, Claire-Marie; Bailleux, Virginie; Gertler, Arieh; Djiane, Jean; Taouis, Mohammed

    2009-03-01

    Growing evidences suggest that obesity is associated with hypothalamic leptin resistance, leading to the alteration of food intake control. Alternative treatment using ciliary neurotrophic factor (CNTF) has been suggested because CNTF exerts a leptin-like effect, even in leptin-resistant states, but the mechanisms by which CNTF maintains this effect are not yet understood. Both leptin and CNTF act in the hypothalamus through similar signaling pathways including janus kinase-2/signal transducer and activator of transcription (STAT)-3 pathway. To explore the differences and interactions between leptin and CNTF signaling pathways, differentiated human neuroblastoma cells (SH-SY5Y) were exposed to either leptin or CNTF and then challenged for each cytokine. Leptin pretreatment completely abolished leptin-dependent STAT-3 and ERK 1/2 phosphorylations without affecting CNTF action. The lack of cross-desensitization between leptin and CNTF signaling pathways occurred despite the induction of suppressor of cytokine signaling-3 in response to both cytokines. Interestingly, leptin as well as insulin induced the expression of phosphotyrosine phosphatase (PTP)-1B, whereas CNTF treatment did not affect its expression. In addition, acute leptin treatment but not CNTF induced PTP-1B expression in mouse hypothalamic arcuate nucleus. Furthermore, the overexpression of human PTP-1B in SH-SY5Y cells completely abolished leptin- and insulin-dependent janus kinase-2, STAT-3, and ERK 1/2 phosphorylations, but CNTF action was not altered. Collectively, our results suggest that PTP-1B constitutes a key divergent element between leptin/insulin and CNTF signaling pathways at the neuronal level, which may constitute a possible mechanism that explains the efficacy of CNTF in leptin-resistant states.

  10. Leptin Involvement in Primary Brain and Pituitary Tumors: Therapeutic Potential, Prognostic Value, and Proposed Diagnostic Application.

    Science.gov (United States)

    Bikis, Christos; Tzanavari, Theodora; Alexandraki, Krystallenia I; Theocharis, Stamatios

    2018-02-20

    Brain tumors are associated with increased mortality and morbidity and are the most common cancer type in children and young adults. The present review focuses on the interplay between leptin, the most extensively studied adipokine, and the onset, development, and treatment of primary brain and intracranial tumors. The two main mechanisms for increased leptin levels in intracranial tumor survivors, leptin resistance caused by hypothalamic damage, or secondary to obesity, are discussed. The contradicting mechanistic observations on leptin being able to both promote tumorinogenesis (e.g., in gliomas) as well as inhibit it (e.g., in adenomas) are also reported. Additionally, the relevant current and future clinical applications, including most notably the proposed use of serum leptin measurements for non-invasive brain tumor diagnostics, are also reported.

  11. Psoriasis and Obesity

    Directory of Open Access Journals (Sweden)

    Mehmet Ali Gürer

    2012-03-01

    Full Text Available In recent years, it has been thought that a strong association exists between metabolic syndrome, specifically obesity, and psoriasis. Obesity is a multifactorial disease affected by both genetic and environmental factors. Adipokines (e.g. leptin secreted by the adipose tissue are believed to play a role in the pathogenesis of psoriasis. The main role of leptin is to adjust metabolism by controlling appetite. Serum leptin levels in patients with severe and moderate psoriasis were found to be higher than in normal control groups. In many similar studies, leptin secretion has been found to stimulate keratinocyte proliferation, which is one of the characteristics of psoriasis. Although many studies showed increased prevalence of obesity in psoriasis patients, few others reported development of obesity in psoriasis patients. Additionally, obesity was found to affect treatment responses not only in classical systemic/topical treatment approaches in psoriasis, but also in newer biological treatments. Overall, increasing epidemiological evidence suggests strong association between obesity and psoriasis, increase in serum leptin levels is thought to have a major role, and weight loss may have significant impact on response to treatment.

  12. Proresolving protein Annexin A1: The role in type 2 diabetes mellitus and obesity.

    Science.gov (United States)

    Pietrani, Nathalia T; Ferreira, Cláudia N; Rodrigues, Kathryna F; Perucci, Luiza O; Carneiro, Fernanda S; Bosco, Adriana A; Oliveira, Marina C; Pereira, Solange S; Teixeira, Antônio L; Alvarez-Leite, Jacqueline I; Ferreira, Adaliene V; Sousa, Lirlândia P; Gomes, Karina B

    2018-04-17

    Annexin A1 (AnxA1) is a protein involved in inflammation resolution that might be altered in obesity-associated type 2 diabetes mellitus (DM), which is a chronic inflammatory disease. The aim of this study was to evaluate AnxA1 serum levels in individuals with and without DM stratified according to the body mass index (BMI), and the dynamic of AnxA1 expression in adipose tissue from humans with obesity and non-obesity. Serum samples were obtained from 41 patients with DM (lean, overweight and obese) and 40 controls, and adipose tissue samples were obtained from 16 individuals with obesity (with or without DM), and 15 controls. DM patients showed similar AnxA1 serum levels when compared to controls. However, when the individuals were stratified according to BMI, AnxA1 levels were higher in individuals with obesity than lean or overweight, and in overweight compared to lean individuals. Moreover, AnxA1 was correlated positively with IL-6 levels. AnxA1 levels were also positively correlated with BMI, waist circumference and waist-to-hip ratio. Furthermore, higher levels of cleaved AnxA1 were observed in adipose tissue from individuals with obesity, independently of DM status. Enhanced levels of AnxA1 in serum of individuals with obesity suggest an attempt to counter-regulate the systemic inflammation process in this disease. However, the higher levels of cleaved AnxA1 in the adipose tissue of individuals with obesity could compromise its anti-inflammatory and proresolving actions, locally. Considering our data, AnxA1 cleavage in the adipose tissue, despite increased serum levels of this protein, and consequently the failure in inflammation resolution, suggests an important pathophysiological mechanism involved in inflammatory status observed in obesity. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  13. Leptin differentially increases sympathetic nerve activity and its baroreflex regulation in female rats: role of oestrogen

    Science.gov (United States)

    Shi, Zhigang; Brooks, Virginia L

    2015-01-01

    Key points Leptin increases sympathetic nerve activity (SNA) in males, which contributes to obesity-induced hypertension; however, whether leptin is equally effective in females is unknown. We report that leptin does increase SNA and heart rate in female rats; however, for lumbar and renal SNA, this action is only evident in pro-oestrus and in oestrogen-treated ovariectomized rats, but not in ovariectomized or dioestrus rats. Leptin increases SNA and heart rate similarly in male and pro-oestrus female rats; however, leptin increases arterial pressure only in males. Blockade of MC3/4 receptors in the paraventricular nucleus (PVN) with SHU9119 decreases SNA in leptin-treated pro-oestrus rats, suggesting that leptin increases SNA in part by increasing α-melanocyte-stimulating hormone drive of PVN presympathetic neurons. Our data establish sex differences in leptin's effects to increase SNA and arterial pressure, which emphasizes the need for enhanced recognition and investigation of sex differences in obesity-induced sympathoexcitation and hypertension. Abstract Obesity and hypertension are commonly associated, and activation of the sympathetic nervous system is considered to be a major contributor, at least in part due to the central actions of leptin. However, while leptin increases sympathetic nerve activity (SNA) in males, whether leptin is equally effective in females is unknown. Here, we show that intracerebroventricular (i.c.v.) leptin increases lumbar (LSNA) and renal (RSNA) SNA and baroreflex control of LSNA and RSNA in α-chloralose anaesthetized female rats, but only during pro-oestrus. In contrast, i.c.v. leptin increased basal and baroreflex control of splanchnic SNA (SSNA) and heart rate (HR) in rats in both the pro-oestrus and dioestrus states. The effects of leptin on basal LSNA, RSNA, SSNA and HR were similar in males and pro-oestrus females; however, i.c.v. leptin increased mean arterial pressure (MAP) only in males. Leptin did not alter LSNA or HR

  14. Influence of weeks of circadian misalignment on leptin levels

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    June Nguyen

    2009-12-01

    Full Text Available June Nguyen, Kenneth P Wright JrDepartment of Integrative Physiology, Sleep and Chronobiology Laboratory, University of Colorado, Boulder, CO, USAAbstract: The neurobiology of circadian, wakefulness–sleep, and feeding systems interact to influence energy homeostasis. Sleep and circadian disruptions are reported to be associated with increased risk of diabetes and obesity, yet the roles of energy balance hormones in these associations are largely unknown. Therefore, in the current study we aimed to assess the influence of several weeks of circadian misalignment (sleep and wakefulness occurring at an inappropriate biological time on the anorexigenic adipocyte hormone leptin. We utilized data from a previous study designed to assess physiological and cognitive consequences of changes in day length and light exposure as may occur during space flight, including exploration class space missions and exposure to the Martian Sol (day length. We hypothesized that circadian misalignment during an exploration class spaceflight simulation would reduce leptin levels. Following a three-week ~8 hours per night home sleep schedule, 14 healthy participants lived in the laboratory for more than one month. After baseline data collection, participants were scheduled to either 24.0 or 24.6 hours of wakefulness–sleep schedules for 25 days. Changes in the phase of the circadian melatonin rhythm, sleep, and leptin levels were assessed. Half of participants analyzed exhibited circadian misalignment with an average change in phase angle from baseline of ~4 hours and these participants showed reduced leptin levels, sleep latency, stage 2 and total sleep time (7.3 to 6.6 hours and increased wakefulness after sleep onset (all P < 0.05. The control group remained synchronized and showed significant increases in sleep latency and leptin levels. Our findings indicate that weeks of circadian misalignment, such as that which occurs in circadian sleep disorders, alters leptin

  15. Leptin and body mass index in polycystic ovary syndrome

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    Nasrin Jalilian

    2016-01-01

    Full Text Available Objective: Polycystic ovary syndrome (PCOS is a common endocrine disorder associated with obesity. Human and animal studies showed a direct relationship between leptin level and obesity, however, results from different studies were mixed. This study investigated the status of leptin level in PCOS and its relationship with body mass index (BMI in a group of Iranian women with PCOS. Methods: In this cross-sectional study, 40 women with PCOS and 36 healthy women were assigned to experimental and control groups, respectively. Those in the PCOS group were not prescribed any medications for 3 months prior to the study. Fasting blood samples were then collected during the 2nd or 3rd day of menstruation for laboratory measurement of serum total leptin, blood glucose (fasting blood sugar, serum insulin, follicle-stimulating hormone, and luteinizing hormone (LH. Results: Mean BMI of the PCOS and control groups were 26.62 ± 4.03 kg/m2 and 23.52 ± 2.52 kg/m2, respectively (P = 0.006. The mean total leptin in the PCO group was also 10.69 ± 5.37 ng/mL and 5.73 ± 2.36 ng/mL in the control group (P = 0.0001. A significant relationship was found between leptin level and BMI as well as LH level among women with PCOS (P 0.05. Conclusion: The results of this study indicated an increased leptin level among women with PCOS that positively associated with BMI and LH.

  16. Hepatic protein tyrosine phosphatase receptor gamma links obesity-induced inflammation to insulin resistance

    OpenAIRE

    Brenachot, Xavier; Ramadori, Giorgio; Ioris, Rafael M.; Veyrat-Durebex, Christelle; Altirriba, Jordi; Aras, Ebru; Ljubicic, Sanda; Kohno, Daisuke; Fabbiano, Salvatore; Clement, Sophie; Goossens, Nicolas; Trajkovski, Mirko; Harroch, Sheila; Negro, Francesco; Coppari, Roberto

    2017-01-01

    Obesity-induced inflammation engenders insulin resistance and type 2 diabetes mellitus (T2DM) but the inflammatory effectors linking obesity to insulin resistance are incompletely understood. Here, we show that hepatic expression of Protein Tyrosine Phosphatase Receptor Gamma (PTPR-γ) is stimulated by inflammation in obese/T2DM mice and positively correlates with indices of inflammation and insulin resistance in humans. NF-κB binds to the promoter of Ptprg and is required for inflammation-ind...

  17. 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.

  18. 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.

  19. The molecular mechanism of leptin secretion and expression induced by aristolochic acid in kidney fibroblast.

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    Tsung-Chieh Lin

    Full Text Available BACKGROUND: Leptin is a peptide hormone playing pivotal role in regulating food intake and energy expenditure. Growing evidence has suggested the pro-inflammatory and fibrogenic properties of leptin. In addition, patients with renal fibrosis have higher level of plasma leptin, which was due to the increased leptin production. Aristolochic acid (AA is a botanical toxin characterized to associate with the development of renal fibrosis including tubulointerstitial fibrosis. However, whether leptin is upregulated to participate in AA-induced kidney fibrosis remain completely unknown. METHODOLOGY/PRINCIPAL FINDINGS: In this study, leptin expression was increased by sublethal dose of AA in kidney fibroblast NRK49f determined by enzyme-linked immunosorbent assay and Western blot. Data from real-time reverse transcriptase-polymerase chain reaction revealed that leptin was upregulated by AA at transcriptional level. DNA binding activity of CCAAT enhancer binding protein α (C/EBP α, one of the transcription factors for leptin gene, was enhanced in DNA affinity precipitation assay and chromatin immunoprecipitation experiments. Knockdown of C/EBP α expression by small interfering RNA markedly reduced AA-induced leptin expression. Moreover, AA promoted Akt interaction with p-PDK1, and increased phosphorylated activation of Akt. Akt knockdown, and inhibition of Akt signaling by LY294002 and mTOR inhibitor rapamycin reduced leptin expression. Furthermore, treatment of LY294002 or rapamycin significantly suppressed AA-induced C/EBP α DNA-binding activity. These results suggest that Akt and C/EBP α activation were involved in AA-regulated leptin expression. CONCLUSIONS/SIGNIFICANCE: Our findings demonstrate the first that AA could induce secretion and expression of fibrogenic leptin in kidney fibroblasts, which reveal potential involvement of leptin in the progression of kidney fibrosis in aristolochic acid nephropathy.

  20. Association of leptin with hemodialysis-related muscle cramps: a cross-sectional study.

    Science.gov (United States)

    Hung, Chung-Ying; Chen, Yung-Liang; Chen, Chiou-Shya; Yang, Chwei-Shiun; Peng, Sheng-Jeng

    2009-01-01

    The mechanism of muscle cramp in hemodialysis patients is not well understood. Leptin, a middle molecule uremic toxin, is able to affect neuronal activity. This study aimed to determine the association between leptin and hemodialysis-related muscle cramps. A total of 79 hemodialysis patients were enrolled. The episodes of hemodialysis-related muscle cramps were recorded over a 28-day period. Serum levels of leptin were measured on the 15th day, a mid-week dialysis session. Frequent hemodialysis-related cramps were associated with old age and elevated serum leptin levels. The risk of frequent hemodialysis-related cramps increased with increasing tertiles of leptin concentration. This relationship remained significant after adjustment for age, mean ultrafiltration ratio, gender, body mass index, insulin, resistin, c-reactive protein, albumin, peripheral arterial disease, electrolytes, and beta(2)-microglobulin. Leptin levels are associated with frequent hemodialysis-related cramps. Further studies are necessary to elucidate the underlying mechanisms.

  1. Serum leptin level and its significance in chronic renal failure hemodialysis patients

    International Nuclear Information System (INIS)

    Zhang Yong; You Yuping; Chen Weizhen; Mo Congjian

    2003-01-01

    To study serum leptin level in chronic renal failure (CRF) hemodialysis patients and the relationship between serum leptin level and residue renal function, body composition, and indices of malnutrition, 31 end-stage CRF hemodialysis patients and 38 healthy people were enrolled. Serum leptin levels were detected by radioimmunoassay. BMI, %Fat and LBM were measured by bioelectrical impedance analysis device. Alb, Chol, Hgb, BUN, SCr and Ccr of the patients were also examined. Results showed that Serum leptin level in end-stage CRF hemodialysis patients was markedly higher than that in healthy controls (P 0.05). Conclusion: Hyperleptinemia existed in end-stage CRF hemodialysis patients and might cause the loss of LBM. The leptin level was not correlated with residue renal function, but it could reflect the fat content. However, serum leptin did not play a significant role in protein malnutrition in end-stage CRF hemodialysis patients

  2. Circulating leptin in patients with chronic obstructive pulmonary disease.

    Science.gov (United States)

    Takabatake, N; Nakamura, H; Abe, S; Hino, T; Saito, H; Yuki, H; Kato, S; Tomoike, H

    1999-04-01

    Unexplained weight loss is common in patients with chronic obstructive pulmonary disease (COPD). Since leptin, an obesity gene product, is known to play important roles in the control of body weight and energy expenditure, we investigated serum leptin levels, along with circulating tumor necrosis factor-alpha (TNF-alpha) and soluble TNF receptor (sTNF-R55 and -R75) levels, in 31 patients with COPD and 15 age-matched healthy controls. The body mass index (BMI) and percent body fat (%fat) were significantly lower in the COPD patients than in the healthy controls (BMI = 18.1 +/- 2.7 kg/m2 versus 22.8 +/- 2.2 kg/m2 [mean +/- SD]; p leptin levels were significantly lower in the COPD patients than in the healthy controls (1.14 +/- 1.17 ng/ml versus 2.47 +/- 2.01 ng/ml; p COPD patients than in the healthy controls. Importantly, circulating leptin levels (log transformed) did correlate well with BMI and %fat, but not with TNF-alpha or with sTNF-R levels in the COPD patients. These data suggest that circulating leptin is independent of the TNF-alpha system and is regulated physiologically even in the presence of cachexia in patients with COPD.

  3. 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.

  4. Serum leptin and its relationship with metabolic variables in Arabs with type 2 diabetes mellitus

    International Nuclear Information System (INIS)

    Al-Shoumer, Kamal A.; Doi, Suhail A.; Vasanthy, Bagavathy A.; Al-Asousi, Adnan A.

    2008-01-01

    Most studies on serum leptin in type 2 diabetes mellitus have focused on white populations. We studied serum leptin concentrations and parameters related to glycemic control and the association between leptin levels and anthropometric and metabolic factors in Arab patients with type 2 diabetes and in Arab control subjects. Ninety-two patients (65 females and 27 males) with type 2 diabetes and 69 matched normal and control subjects (48 females and 21 males) were included. Anthropometric measures (including body mass index (BMI) and waist: hip ratio) were assessed in all subjects. After an overnight fast, blood was collected for serum leptin assay. Other metabolic parameters include glucose, insulin, C-peptide, intact proinsulin, insulin resistance index (HOMA-IR), insulin-like growth factor 1 (IGF-1), lipids and hemoglobin A 1c (HbA) were determined. Fasting serum leptin levels, IGF-1 and high-density lipoprotein (HDL) cholesterol were similar in patients with type 2 diabetes and control subjects. When obese subjects (BMI>-30kg/m2) were analyzed separately, serum levels of leptin were significantly lower in patients compared to controls. In contrast, patients had higher fasting glucose, insulin, C-peptide, intact proinsulin, insulin resistance, total cholesterol, triglycerides, HbA, and a larger waist circumference and waist-to-hip ratio than controls. Serum leptin correlated positively with BM, negatively with waist-to-hip ratio, and demonstrated no relationship to other parameters. Patients with type 2 diabetes in an Arab ethnic population showed evidence of an unfavorable metabolic profile despite having leptin levels similar to controls. Obesity influences serum leptin levels more significantly in type 2 diabetes, in which leptin levels tends to be low. (author)

  5. Leptin/HER2 crosstalk in breast cancer: in vitro study and preliminary in vivo analysis

    International Nuclear Information System (INIS)

    Fiorio, Elena; Bonetti, Franco; Giordano, Antonio; Cetto, Gian Luigi; Surmacz, Eva; Mercanti, Anna; Terrasi, Marianna; Micciolo, Rocco; Remo, Andrea; Auriemma, Alessandra; Molino, Annamaria; Parolin, Veronica; Di Stefano, Bruno

    2008-01-01

    Obesity in postmenopausal women is associated with increased breast cancer risk, development of more aggressive tumors and resistance to certain anti-breast cancer treatments. Some of these effects might be mediated by obesity hormone leptin, acting independently or modulating other signaling pathways. Here we focused on the link between leptin and HER2. We tested if HER2 and the leptin receptor (ObR) can be coexpressed in breast cancer cell models, whether these two receptors can physically interact, and whether leptin can transactivate HER2. Next, we studied if leptin/ObR can coexist with HER2 in breast cancer tissues, and if presence of these two systems correlates with specific clinicopathological features. Expression of ObR, HER2, phospo-HER2 was assessed by immonoblotting. Physical interactions between ObR and HER2 were probed by immunoprecipitation and fluorescent immunostaining. Expression of leptin and ObR in breast cancer tissues was detected by immunohistochemistry (IHC). Associations among markers studied by IHC were evaluated using Fisher's exact test for count data. HER2 and ObR were coexpressed in all studied breast cancer cell lines. In MCF-7 cells, HER2 physically interacted with ObR and leptin treatment increased HER2 phosphorylation on Tyr 1248. In 59 breast cancers, the presence of leptin was correlated with ObR (the overall association was about 93%). This result was confirmed both in HER2-positive and in HER2-negative subgroups. The expression of leptin or ObR was numerically more frequent in larger (> 10 mm) tumors. Coexpression of HER2 and the leptin/ObR system might contribute to enhanced HER2 activity and reduced sensitivity to anti-HER2 treatments

  6. Dietary Protein in the Prevention of Diet-Induced Obesity and Co-Morbidities

    DEFF Research Database (Denmark)

    Tastesen, Hanne Sørup

    mice were fed obesity‐promoting diets with protein from different sources, in different forms and at different levels to evaluate the affect on development of obesity, glucose intolerance and dyslipidemia. Results: In the present study the dietary level of protein, 16 versus 32 percent energy from...... protein, was found to be negligible in development of obesity and co‐morbidities in mice. Seafood protein with high endogenous taurine and glycine contents was found to prevent diet‐induced adiposity and dyslipidemia, both in ad libitum and pair‐fed settings. The ability of seafood proteins to prevent...... that the source and form of protein has great impact on development and prevention of diet‐induced adiposity, dyslipidemia, hyperinsulinemia and impairment of glucose tolerance through modulations of voluntary locomotor activity, energy expenditure and energy substrate metabolism in mice...

  7. 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

  8. Genetic Association of Major Depression With Atypical Features and Obesity-Related Immunometabolic Dysregulations

    DEFF Research Database (Denmark)

    Milaneschi, Yuri; Lamers, Femke; Peyrot, Wouter J

    2017-01-01

    subgroups of patients with MDD stratified according to the A/W criterion had a different degree of genetic overlap with obesity-related traits (body mass index [BMI] and levels of C-reactive protein [CRP] and leptin). Design, Setting, and Patients: This multicenter study assembled genome-wide genotypic...... between atypical depressive symptoms and obesity-related traits may arise from shared pathophysiologic mechanisms in patients with MDD. Development of treatments effectively targeting immunometabolic dysregulations may benefit patients with depression and obesity, both syndromes with important disability....

  9. Hypothyroidism reduces ObRb-STAT3 leptin signalling in the hypothalamus and pituitary of rats associated with resistance to leptin acute anorectic action.

    Science.gov (United States)

    Calvino, Camila; Souza, Luana L; Costa-e-Sousa, Ricardo H; Almeida, Norma A S; Trevenzoli, Isis H; Pazos-Moura, Carmen C

    2012-10-01

    Leptin has been shown to regulate the hypothalamus-pituitary-thyroid axis, acting primarily through the STAT3 pathway triggered through the binding of leptin to the long-chain isoform of the leptin receptor, ObRb. We previously demonstrated that although hyperthyroid rats presented leptin effects on TSH secretion, those effects were abolished in hypothyroid rats. We addressed the hypothesis that changes in the STAT3 pathway might explain the lack of TSH response to leptin in hypothyroidism by evaluating the protein content of components of leptin signalling via the STAT3 pathway in the hypothalamus and pituitary of hypothyroid (0·03% methimazole in the drinking water/21 days) and hyperthyroid (thyroxine 5 μg/100 g body weight /5 days) rats. Hypothyroid rats exhibited decreased ObRb and phosphorylated STAT3 (pSTAT3) protein in the hypothalamus, and in the pituitary gland they exhibited decreased ObRb, total STAT3, pSTAT3 and SOCS3 (P<0·05). Except for a modest decrease in pituitary STAT3, no other alterations were observed in hyperthyroid rats. Moreover, unlike euthyroid rats, the hypothyroid rats did not exhibit a reduction in food ingestion after a single injection of leptin (0·5 mg/kg body weight). Therefore, hypothyroidism decreased ObRb-STAT3 signalling in the hypothalamus and pituitary gland, which likely contributes to the loss of leptin action on food intake and TSH secretion, as previously observed in hypothyroid rats.

  10. Developmental changes in the relationship between leptin and adiposity among Tsimané children and adolescents.

    Science.gov (United States)

    Sharrock, Katherine C B; Kuzawa, Christopher W; Leonard, William R; Tanner, Susan; Reyes-García, Victoria E; Vadez, Vincent; Huanca, Tomás; McDade, Thomas W

    2008-01-01

    Leptin is thought to signal energy stores, thus helping the body balance energy intake and expenditure. However, the strong relationship between leptin and adiposity in populations with adequate nutrition or common obesity is not universal across ecologic contexts, and leptin often correlates only weakly, or not at all, with adiposity in populations of lean or marginally-nourished males. To clarify whether the relationship between adiposity and leptin changes during development, this study examines leptin and body fat among children and adolescents of lowland Bolivia. Anthropometric measures of body composition and dried blood spot samples were collected from 487 Tsimane' ranging from 2 to 15 years of age. Leptin was assayed using an enzyme immunoassay protocol validated for use with blood spot samples. In this population, leptin concentrations were among the lowest reported in a human population (mean +/- SD: 1.26 +/- 0.5 and 0.57 +/- 0.3 in females and males). In addition, the relationship between leptin and adiposity follows distinct developmental trajectories in males and females. In males, leptin is weakly correlated with most measures of body composition at all ages investigated. However, in females, the level of body fat and the strength of the correlation between body fat and leptin (a measure of its strength as a signal of energy stores) both increase markedly with age. These findings suggest a more important role of leptin as a signal of energy stores among females as they approach reproductive maturity, while raising questions about the function of this hormone in lean males. Copyright 2008 Wiley-Liss, Inc.

  11. Childhood sleep duration and quality in relation to leptin concentration in two cohort studies.

    Science.gov (United States)

    Boeke, Caroline E; Storfer-Isser, Amy; Redline, Susan; Taveras, Elsie M

    2014-03-01

    Poor sleep in childhood is associated with increased obesity risk, possibly by affecting appetite-regulating hormones such as leptin. We examined short- and long-term sleep duration and quality in relation to leptin in two US pediatric cohorts. Analysis of data from two prospective cohort studies. Population-based. Adolescent polysomnography assessments performed in a clinical research unit. Children in Project Viva (n = 655) and adolescents in the Cleveland Children's Sleep & Health Study (n = 502). N/A. In Project Viva, mothers reported average child sleep duration annually from infancy through age 7, and we measured leptin at ages 3 and 7. In the Cleveland Children's Sleep & Health Study, we collected self-reported sleep duration, polysomnography-derived measures of sleep quality, and fasting leptin at ages 16-19. In sex-stratified linear regression analyses adjusted for sociodemographic characteristics and adiposity, chronic curtailed sleep was associated with lower leptin at age 7 in girls; a one-unit decrease in sleep score was associated with a 0.08 decrease in log leptin (95% CI: 0.01,0.15). The association was stronger in girls with greater adiposity (P = 0.01). Among adolescents, shorter sleep was associated with lower leptin in males; each one-hour decrease in sleep duration was associated with a 0.06 decrease in log leptin (95% CI: 0.00, 0.11). Sleep duration was not associated with leptin at other ages. Sleep quality indices were not associated with leptin. Our results suggest possible age-specific sexual dimorphism in the influence of sleep on leptin, which may partly explain inconsistencies in the literature.

  12. A Hypothalamic Leptin-Glutamate Interaction in the Regulation of Sympathetic Nerve Activity

    Directory of Open Access Journals (Sweden)

    Hong Zheng

    2017-01-01

    Full Text Available Accumulated evidence indicates that obesity-induced type 2 diabetes (T2D is associated with enhanced sympathetic activation. The present study was conducted to investigate the role for leptin-glutamate signaling within the hypothalamus in regulating sympathetic nerve activity. In anesthetized rats, microinjections of leptin (5 ng ~ 100 ng into the arcuate nucleus (ARCN and paraventricular nucleus (PVN induced increases in renal sympathetic nerve activity (RSNA, blood pressure (BP, and heart rate (HR. Prior microinjections of NMDA receptor antagonist AP5 (16 pmol into the ARCN or PVN reduced leptin-induced increases in RSNA, BP, and HR in both ARCN and PVN. Knockdown of a leptin receptor with siRNA inhibited NMDA-induced increases in RSNA, BP, and HR in the ARCN but not in the PVN. Confocal calcium imaging in the neuronal NG108 and astrocytic C6 cells demonstrated that preincubation with leptin induced an increase in intracellular calcium green fluorescence when the cells were challenged with glutamate. In high-fat diet and low-dose streptozotocin-induced T2D rats, we found that leptin receptor and NMDA NR1 receptor expressions in the ARCN and PVN were significantly increased. In conclusion, these studies provide evidence that within the hypothalamic nuclei, leptin-glutamate signaling regulates the sympathetic activation. This may contribute to the sympathoexcitation commonly observed in obesity-related T2D.

  13. Hormonal and adiposity state of women with polycystic ovary syndrome: implication of adiponectin and leptin

    Directory of Open Access Journals (Sweden)

    Aleksandra Atanasova Boshku

    2016-12-01

    Full Text Available Obesity and insulin resistance are frequently seen comorbidities in patients with polycystic ovary syndrome (PCOS, affecting the already disturbed metabolism of these patients. Disturbed secretion of adiponectin and leptin could be one of the contributing factors of obesity and insulin resistance in patients with PCOS. The aim of this study was to determine the levels of adiponectin and leptin in PCOS patients, as well as their association with other components of the syndrome. This cross-sectional study determined clinical, hormonal, and biochemical markers in 61 women with PCOS and 56 controls. There was a statistically significant difference in adiponectin and leptin between the groups (p>0.001. There was a significant negative correlation between adiponectin, body mass index (BMI, and waist circumference (r= -0.478; -0.452, p<0.001 and a negative correlation with testosterone, free androgen index (FAI, insulin, and the homeostasis model assessment for insulin resistance (HOMA-IR. A positive correlation between adiponectin, sex hormone binding globulin (SHGB, and fasting glucose levels was present. Correlation analysis of leptin with other metabolic parameters showed a positive correlation with BMI, waist circumference, insulin, and HOMA-IR. A significant inverse correlation was present between leptin and SHGB. In conclusion, adiponectin and leptin may serve as potential biomarkers of insulin resistance. Determining levels of adiponectin and leptin in the early course of this syndrome may enable earlier diagnosis of insulin resistance, or even early prevention in PCOS patients.

  14. Placental protein-13 (PP13) in combination with PAPP-A and free leptin index (fLI) in first trimester maternal serum screening for severe and early preeclampsia

    DEFF Research Database (Denmark)

    Villiers, Carin P.De; Hedley, Paula L.; Placing, Sophie

    2017-01-01

    +3-13+6) maternal serum from 120 PE pregnancies and 267 control pregnancies and was correlated with clinical parameters. The population screening performance of PP13 in combination with the PE markers pregnancy associated plasma protein A (PAPPA) and free leptin index (fLI) was assessed by Monte Carlo simulation....... In severe PE (including HELLP) cases (n=26) the median PP13 concentration was 35.8 pg/mL (range: 17.8-85.5 pg/mL) and in PE pregnancies (n=10) with birth prior to week 34, the median PP13 concentration was 30.6 pg/mL (13.1-50.1 pg/mL), compared to controls with a median of 54.8 pg/mL (range: 15.4-142.6 pg...

  15. Positive correlation of serum leptin with estradiol levels in patients with polycystic ovary syndrome

    Directory of Open Access Journals (Sweden)

    Mendonça H.C.

    2004-01-01

    Full Text Available Patients with polycystic ovary syndrome (PCOS usually are obese, insulin resistant and hyperinsulinemic. The known association between leptin, obesity andinsulin action suggests that leptin may have a role in PCOS but this has only been addressed peripherally. This study was designed to assess the relationship between serum leptin and the anthropometric, metabolic and endocrine variables of obese (body mass index, BMI ³30 kg/m² and non-obese (BMI <30 kg/m² PCOS patients. Twenty-eight PCOS patients and 24 control women subdivided into obese and non-obese groups were evaluated. Leptin, androgens, lipids, gonadotrophins and insulin-glucose response to the oral glucose tolerance test were measured by radioimmunoassay in all participants. The assays were done all in one time. The areas under the insulin curve (AUC-I and the glycemia curve were calculated to identify patients with insulin resistance. Mean leptin levels were not significantly higher in patients with PCOS compared to the control group (21.2 ± 10.2 vs 27.3 ± 12.4 ng/ml. Leptin levels were found to be significantly higher in the obese subgroups both in patients with PCOS (26.9 ± 9.3 vs 14.1 ± 7.0 ng/ml and in the control group (37.3 ± 15.5 vs 12.9 ± 5.8 ng/ml. The leptin of the PCOS group was correlated with BMI (r = 0.74; P < 0.0001 and estradiol (r = 0.48; P < 0.008 and tended to be correlated with the AUC-I (r = 0.36; P = 0.05. Of the parameters which showed a correlation with leptin in PCOS, only estradiol and probably insulinemia (AUC-I did not show a significant correlation with BMI, suggesting that the other parameters were correlated with leptin due to their correlation with BMI. Estradiol correlated with leptin in PCOS patients regardless of their weight.

  16. Weight Perturbation Alters Leptin Signal Transduction in a Region-Specific Manner throughout the Brain

    OpenAIRE

    Morabito, Michael V.; Ravussin, Yann; Mueller, Bridget R.; Skowronski, Alicja A.; Watanabe, Kazuhisa; Foo, Kylie S.; Lee, Samuel X.; Lehmann, Anders; Hjorth, Stephan; Zeltser, Lori M.; LeDuc, Charles A.; Leibel, Rudolph L.

    2017-01-01

    Diet-induced obesity (DIO) resulting from consumption of a high fat diet (HFD) attenuates normal neuronal responses to leptin and may contribute to the metabolic defense of an acquired higher body weight in humans; the molecular bases for the persistence of this defense are unknown. We measured the responses of 23 brain regions to exogenous leptin in 4 different groups of weight- and/or diet-perturbed mice. Responses to leptin were assessed by quantifying pSTAT3 levels in brain nuclei 30 minu...

  17. Mitofusin 2 in POMC neurons connects ER stress with leptin resistance and energy imbalance

    DEFF Research Database (Denmark)

    Schneeberger, Marc; Dietrich, Marcelo O; Sebastián, David

    2013-01-01

    Mitofusin 2 (MFN2) plays critical roles in both mitochondrial fusion and the establishment of mitochondria-endoplasmic reticulum (ER) interactions. Hypothalamic ER stress has emerged as a causative factor for the development of leptin resistance, but the underlying mechanisms are largely unknown....... This previously unrecognized role for MFN2 argues for a crucial involvement in mediating ER stress-induced leptin resistance........ Here, we show that mitochondria-ER contacts in anorexigenic pro-opiomelanocortin (POMC) neurons in the hypothalamus are decreased in diet-induced obesity. POMC-specific ablation of Mfn2 resulted in loss of mitochondria-ER contacts, defective POMC processing, ER stress-induced leptin resistance...

  18. Adiponectin and leptin as first trimester markers for gestational diabetes mellitus

    DEFF Research Database (Denmark)

    Thagaard, Ida Näslund; Krebs, Lone; Holm, Jens Christian

    2017-01-01

    Background: Gestational diabetes mellitus (GDM) is increasing partly due to the obesity epidemic. Adipocytokines have thus been suggested as first trimester screening markers for GDM. In this study we explore the associations between body mass index (BMI) and serum concentrations of adiponectin......, leptin, and the adiponectin/leptin ratio. Furthermore, we investigate whether these markers can improve the ability to screen for GDM in the first trimester. Methods: A cohort study in which serum adiponectin and leptin were measured between gestational weeks 6+0 and 14+0 in 2590 pregnant women...

  19. Training, leptin receptors and SOCS3 in human muscle.

    Science.gov (United States)

    Olmedillas, H; Guerra, B; Guadalupe-Grau, A; Santana, A; Fuentes, T; Dorado, C; Serrano-Sanchez, J A; Calbet, J A L

    2011-05-01

    Endurance exercise induces SUPPRESSOR of CYTOKINE SIGNALING 3 (SOCS3) mRNA expression in rodent skeletal muscle and endurance training overimposed on strength training blunts the hypertrophic response to strength training by an unknown mechanism. The aim of this study was to determine the effects of a concurrent strength and endurance training on fat mass, serum leptin concentration, muscle morphology, and muscle vastus lateralis leptin receptors (OB-Rb) and SOCS3 protein expression. 16 healthy young men were assigned to a control (C; n=7), and to a 12-week weightlifting (3 sessions/week)+endurance training program (T; n=9) group. Training enhanced maximal dynamic strength in lower and upper body exercises (18-54%), reduced fat mass by 1.8 kg and serum leptin concentration per kg of fat mass, and elicited muscle hypertrophy of type 2 (+18.5%, Ptraining. In conclusion, concurrent strength and endurance training reduces fat mass and serum leptin and the ratio leptin/fat mass without significant effects on vastus lateralis OB-Rb protein expression. Training does not increase the basal expression of SOCS3 protein in humans. © Georg Thieme Verlag KG Stuttgart · New York.

  20. Peri-implant parameters and C-reactive protein levels among patients with different obesity levels.

    Science.gov (United States)

    Vohra, Fahim; Alkhudhairy, Fahad; Al-Kheraif, Abdulaziz A; Akram, Zohaib; Javed, Fawad

    2017-11-16

    It is hypothesized that peri-implant conditions are worse with increasing severity of obesity, because systemic low-grade inflammatory marker (C-reactive protein [CRP]) is higher in severe form of obese individuals. The aim of the cross-sectional retrospective study was to compare clinical and radiographic peri-implant inflammatory parameters in patients with different levels of obesity and correlate these parameters with CRP levels. Eighty-four patients who participated in this study were divided into 4 groups: class I obese (group 1), class II obese (group 2), class III obese (group 3), and nonobese individuals (group 4) were included. Clinical (plaque index [PI], bleeding on probing [BOP], probing depth [PD]) and radiographic (marginal bone loss [MBL]) peri-implant parameters were recorded. Serum CRP were quantified using enzyme-linked immunosorbent assay (ELISA). Clinical peri-implant parameters and serum CRP concentrations were analyzed using 1-way analysis of variance. The Pearson correlation coefficient was used to analyze correlations of CRP levels with any of the clinical and radiographic parameters assessed. Peri-implant PI, BOP, PD, and MBL were significantly higher in group-1, -2, and -3 patients as compared to nonobese individuals (P implant PI, BOP, PD, and MBL were significantly higher in obese patients of group-2 and group-3 as compared to obese patients in group-1 (P  .05). A significant positive correlations were found between CRP levels and BOP (P = .0148) and PD (P = .0425); and significant negative correlation was found for MBL in group 3, respectively (P = .0212). Clinical and radiographic peri-implant inflammatory parameters and serum CRP were significantly high in patients with severe form of obesity. Serum CRP levels correlated with peri-implant bleeding in obese patients. These findings are preliminary and long-term controlled trials are recommended to support these outcomes. © 2017 Wiley Periodicals, Inc.

  1. Magel2 is required for leptin-mediated depolarization of POMC neurons in the hypothalamic arcuate nucleus in mice.

    Directory of Open Access Journals (Sweden)

    Rebecca E Mercer

    Full Text Available Prader-Willi Syndrome is the most common syndromic form of human obesity and is caused by the loss of function of several genes, including MAGEL2. Mice lacking Magel2 display increased weight gain with excess adiposity and other defects suggestive of hypothalamic deficiency. We demonstrate Magel2-null mice are insensitive to the anorexic effect of peripherally administered leptin. Although their excessive adiposity and hyperleptinemia likely contribute to this physiological leptin resistance, we hypothesized that Magel2 may also have an essential role in intracellular leptin responses in hypothalamic neurons. We therefore measured neuronal activation by immunohistochemistry on brain sections from leptin-injected mice and found a reduced number of arcuate nucleus neurons activated after leptin injection in the Magel2-null animals, suggesting that most but not all leptin receptor-expressing neurons retain leptin sensitivity despite hyperleptinemia. Electrophysiological measurements of arcuate nucleus neurons expressing the leptin receptor demonstrated that although neurons exhibiting hyperpolarizing responses to leptin are present in normal numbers, there were no neurons exhibiting depolarizing responses to leptin in the mutant mice. Additional studies demonstrate that arcuate nucleus pro-opiomelanocortin (POMC expressing neurons are unresponsive to leptin. Interestingly, Magel2-null mice are hypersensitive to the anorexigenic effects of the melanocortin receptor agonist MT-II. In Prader-Willi Syndrome, loss of MAGEL2 may likewise abolish leptin responses in POMC hypothalamic neurons. This neural defect, together with increased fat mass, blunted circadian rhythm, and growth hormone response pathway defects that are also linked to loss of MAGEL2, could contribute to the hyperphagia and obesity that are hallmarks of this disorder.

  2. Insulin and leptin levels in overweight and normal-weight Iranian adolescents: The CASPIAN-III study

    Directory of Open Access Journals (Sweden)

    Ehsan Bahrami

    2014-01-01

    Full Text Available Background: In this study, we aim to compare insulin and leptin levels in adolescents with or without excess weight and in those with or without abdominal obesity. Materials and Methods : This case-control study was conducted among 486 samples. We randomly selected 243 overweight and an equal number of normal-weight adolescents from among participants of the third survey of a national surveillance program entitled "Childhood and Adolescence Surveillance and PreventIon of Adult Non-communicable diseases study." Serum insulin and leptin were compared between two groups and their correlation was determined with other variables. Results: The mean age and body mass index (BMI of participants were 14.10 ± 2.82 years and 22.12 ± 6.49 kg/m 2 , respectively. Leptin and insulin levels were higher in overweight than in normal-weight adolescents (P < 0.05. Leptin level was higher in children with abdominal obesity than in their other counterparts (P < 0.001. Leptin level was correlated with age, fasting blood glucose, BMI, and insulin level. Conclusion: Insulin and leptin levels were higher among overweight and obese children, which may reflect insulin and leptin-resistance. Given the complications of excess weight from early life, prevention and controlling childhood obesity should be considered as a health priority.

  3. Discovery and characterization of the first genuine avian leptin gene in the rock dove (Columba livia).

    Science.gov (United States)

    Friedman-Einat, Miriam; Cogburn, Larry A; Yosefi, Sara; Hen, Gideon; Shinder, Dmitry; Shirak, Andrey; Seroussi, Eyal

    2014-09-01

    Leptin, the key regulator of mammalian energy balance, has been at the center of a great controversy in avian biology for the last 15 years since initial reports of a putative leptin gene (LEP) in chickens. Here, we characterize a novel LEP in rock dove (Columba livia) with low similarity of the predicted protein sequence (30% identity, 47% similarity) to the human ortholog. Searching the Sequence-Read-Archive database revealed leptin transcripts, in the dove's liver, with 2 noncoding exons preceding 2 coding exons. This unusual 4-exon structure was validated by sequencing of a GC-rich product (76% GC, 721 bp) amplified from liver RNA by RT-PCR. Sequence alignment of the dove leptin with orthologous leptins indicated that it consists of a leader peptide (21 amino acids; aa) followed by the mature protein (160 aa), which has a putative structure typical of 4-helical-bundle cytokines except that it is 12 aa longer than human leptin. Extra residues (10 aa) were located within the loop between 2 5'-helices, interrupting the amino acid motif that is conserved in tetrapods and considered essential for activation of leptin receptor (LEPR) but not for receptor binding per se. Quantitative RT-PCR of 11 tissues showed highest (P < .05) expression of LEP in the dove's liver, whereas the dove LEPR peaked (P < .01) in the pituitary. Both genes were prominently expressed in the gonads and at lower levels in tissues involved in mammalian leptin signaling (adipose; hypothalamus). A bioassay based on activation of the chicken LEPR in vitro showed leptin activity in the dove's circulation, suggesting that dove LEP encodes an active protein, despite the interrupted loop motif. Providing tools to study energy-balance control at an evolutionary perspective, our original demonstration of leptin signaling in dove predicts a more ancient role of leptin in growth and reproduction in birds, rather than appetite control.

  4. Integral Role of PTP1B in Adiponectin-Mediated Inhibition of Oncogenic Actions of Leptin in Breast Carcinogenesis1 2

    OpenAIRE

    Taliaferro-Smith, LaTonia; Nagalingam, Arumugam; Knight, Brandi Brandon; Oberlick, Elaine; Saxena, Neeraj K; Sharma, Dipali

    2013-01-01

    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 inh...

  5. Creating leptin-like biofunctions by active immunization against chicken leptin receptor in growing chickens.

    Science.gov (United States)

    Lei, M M; Wu, S Q; Shao, X B; Li, X W; Chen, Z; Ying, S J; Shi, Z D

    2015-01-01

    In this study, immunization against chicken leptin receptor (cLEPR) extracellular domain (ECD) was applied to investigate leptin regulation and LEPR biofunction in growing chicken pullets. A recombinant protein (cLEPR ECD) based on the cLEPR complemenary DNA sequence corresponding to the 582nd to 796th amino acid residues of cLEPR mature peptide was prepared and used as antigen. Immunization against cLEPR ECD in growing chickens increased anti-cLEPR ECD antibody titers in blood, enhanced proportions of phosphorylated janus kinase 2 (JAK2) and served as signal transducer and activator of transcription 3 (STAT3) protein in liver tissue. Chicken live weight gain and abdominal fat mass were significantly decreased (P chickens. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Subcloning, expression, purification, and characterization of recombinant human leptin-binding domain.

    Science.gov (United States)

    Sandowski, Yael; Raver, Nina; Gussakovsky, Eugene E; Shochat, Suzan; Dym, Orly; Livnah, Oded; Rubinstein, Menachem; Krishna, Radha; Gertler, Arieh

    2002-11-29

    A subdomain of the human leptin receptor encoding part of the extracellular domain (amino acids 428 to 635) was subcloned, expressed in a prokaryotic host, and purified to homogeneity, as evidenced by SDS-PAGE, with over 95% monomeric protein. The purified leptin-binding domain (LBD) exhibited the predicted beta structure, was capable of binding human, ovine, and chicken leptins, and formed a stable 1:1 complex with all mammalian leptins. The binding kinetics, assayed by surface plasmon resonance methodology, showed respective k(on) and k(off) values (mean +/- S.E.) of 1.20 +/- 0.23 x 10(-5) mol(-1) s(-1) and 1.85 +/- 0.30 x 10(-3) s(-1) and a K(d) value of 1.54 x 10(-8) m. Similar results were achieved with conventional binding experiments. LBD blocked leptin-induced, but not interleukin-3-induced, proliferation of BAF/3 cells stably transfected with the long form of human leptin receptor. The modeled LBD structure and the known three-dimensional structure of human leptin were used to construct a model of 1:1 LBD.human leptin complex. Two main residues, Phe-500, located in loop L3, and Tyr-441, located in L1, are suggested to contribute to leptin binding.

  7. Maternal obesity and inflammatory mediators: A controversial association.

    Science.gov (United States)

    Pendeloski, Karen Priscilla Tezotto; Ono, Erika; Torloni, Maria Regina; Mattar, Rosiane; Daher, Silvia

    2017-05-01

    The link between maternal obesity and inflammatory mediators is still unclear. Our aim was to summarize the main findings of recently published studies on this topic. We performed a search in Medline for studies published in the last years on obesity, human pregnancy, and inflammatory mediators. We report the findings of 30 studies. The characteristics and number of participants, study design, gestational age at sample collection, and type of sample varied widely. Approximately two-thirds of them investigated more than one mediator, and 50% included participants in only one trimester of pregnancy. The most frequently investigated mediators were leptin, tumour necrosis factor-alpha (TNF-α), and interleukin (IL)-6. Almost all studies reported an association between maternal obesity, leptin, and C-reactive protein (CRP) serum levels but not with IL-1β and IL-10. The association of IL-6, TNF-α, monocyte chemo-attractant protein-1 (MCP-1), adiponectin, and resistin with maternal obesity is still controversial. To clarify the physiopathological link between maternal obesity and inflammation, more high-quality studies are needed. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. The Impact of LEP G-2548A and LEPR Gln223Arg Polymorphisms on Adiposity, Leptin, and Leptin-Receptor Serum Levels in a Mexican Mestizo Population

    Science.gov (United States)

    Chavarria-Avila, Efraín; Gomez-Bañuelos, Eduardo; Ruiz-Quezada, Sandra-Luz; Castro-Albarran, Jorge; Sánchez-López, Lizeth; Martín-Marquez, Beatriz Teresita; Navarro-Hernández, Rosa-Elena

    2015-01-01

    The polymorphisms in leptin (LEP G-2548A) and leptin-receptor (LEPR Gln223Arg) seem to influence obesity and lipid metabolism among others. The aim of this study was to investigate the effect of these polymorphisms on adiposity, leptin (sLeptin), and leptin-receptor (sLeptin-receptor) serum concentrations as well as inflammation markers. We included 382 adults originally from Western Mexico. They were genotyped by PCR-RFLP. Obese individuals showed higher sLeptin (58.2 ± 31.35 ng/mL) but lower sLeptin-receptor (12.6 ± 3.74 ng/mL) levels than normal weight ones (17.6 ± 14.62 ng/mL, 17.4 ± 4.62 ng/mL, resp.), P < 0.001. Obese subjects carriers of Arg/Arg genotype had more (P = 0.016) sLeptin-receptor (14.7 ± 4.96 ng/mL) and less (P = 0.004) sLeptin (44.0 ± 28.12 ng/mL) levels than Gln/Gln genotype (11.0 ± 2.92 ng/mL, 80.3 ± 33.24 ng/mL, resp.). Body fat mass was lower (P from 0.003 to 0.045) for A/A (36.5% ± 6.80) or Arg/Arg (36.8% ± 6.82) genotypes with respect to G/G (41.3% ± 5.52) and G/A (41.6% ± 5.61) or Gln/Gln (43.7% ± 4.74) and Gln/Arg (41.0% ± 5.52) genotypes carriers. Our results suggest that LEP -2548A and LEPR 223Arg could be genetic markers of less body fat mass accumulation in obese subjects from Western Mexico. PMID:26064921

  9. Relationship between the visceral fat area and adipocytokine in hemodialysis patients. Usefulness of high molecular weight adiponectin-leptin ratio

    International Nuclear Information System (INIS)

    Tsushima, Megumi; Terayama, Yuriko; Tsutaya, Chikako; Momose, Akishi; Funyu, Tomihisa; Ohyama, Chikara; Hada, Ryukichi

    2007-01-01

    Adiponectin and leptin, adipose-specific secretory proteins, are associated with obesity. It has been reported that the plasma adiponectin and leptin concentrations were both higher in women than in men, and were markedly increased among hemodialysis patients in comparison with healthy controls. This study was conduced in 104 hemodialysis patients and 35 healthy controls. To obtain a novel indicator for the visceral fat area in hemodialysis patients, we measured total adiponectin (t-Adipo), high molecular weight adiponectin (h-Adipo) and leptin (Lep) in serum and evaluated visceral and subcutaneous fat areas using computed tomography. In addition, we calculated the percentage of the high molecular weight form per total adiponectin (h-Adipo/t-Adipo) and the ratio of adiponectin to leptin (Adipo/Lep ratio). Hemodialysis patients were divided into four groups based on their visceral fat area level (under 40 cm 2 ; group I, 40-70 cm 2 ; group II, 70-100 cm 2 ; group III, 100 cm 2 or more; group IV). T-Adipo, h-Adipo, leptin and h-Adipo/t-Adipo were significantly higher in women than in men. T-Adipo, h-Adipo and h-Adipo/t-Adipo were lower in group IV than in group I. Leptin were higher in group III and IV than in group I. The T-Adipo/Lep ratio and h-Adipo/Lep ratio were lower in group III and IV than in group I. Especially, the h-Adipo/Lep ratio in group IV was significantly decreased compared with that in group III. By simple regression analysis of the correlation between visceral fat area and each parameter of adipocytokine, the highest correlation coefficients were seen with the log transformed h-Adipo/Lep ratio. Log transformed h-Adipo/Lep ratio were inversely related to visceral fat area for men (y=-36.16 x +75.8, r=-0.558, p<0.001) and for women (y=-36.07 x +68.2, r=-0.725, p<0.001). The two regression lines between-gender difference were equivalent in slope. We conclude that h-Adipo/Lep ratio may be a marker for evaluating visceral fat area in hemodialysis

  10. The unique cysteine knot regulates the pleotropic hormone leptin.

    Directory of Open Access Journals (Sweden)

    Ellinor Haglund

    Full Text Available Leptin plays a key role in regulating energy intake/expenditure, metabolism and hypertension. It folds into a four-helix bundle that binds to the extracellular receptor to initiate signaling. Our work on leptin revealed a hidden complexity in the formation of a previously un-described, cysteine-knotted topology in leptin. We hypothesized that this unique topology could offer new mechanisms in regulating the protein activity. A combination of in silico simulation and in vitro experiments was used to probe the role of the knotted topology introduced by the disulphide-bridge on leptin folding and function. Our results surprisingly show that the free energy landscape is conserved between knotted and unknotted protein, however the additional complexity added by the knot formation is structurally important. Native state analyses led to the discovery that the disulphide-bond plays an important role in receptor binding and thus mediate biological activity by local motions on distal receptor-binding sites, far removed from the disulphide-bridge. Thus, the disulphide-bridge appears to function as a point of tension that allows dissipation of stress at a distance in leptin.

  11. Fetal life malnutrition was not reflected in the relative abundances of adiponectin and leptin mRNAs in adipose tissue in male mink kits at 9.5 weeks of age

    DEFF Research Database (Denmark)

    Matthiesen, Connie Frank; Tauson, Anne-Helene

    2016-01-01

    Background: Malnutrition in fetal life and during suckling have in some animal studies resulted in adaptive changes related to the fat and glucose metabolism, which in the long term might predispose the offspring for metabolic disorders such as obesity later in life. The objective was to study...... the effect of fetal life malnutrition in male mink on the gene expression of leptin and adiponectin in different adipose tissue sites. Results: Thirty-two male mink, strict carnivore species, exposed to low (FL) or adequate (FA) protein provision the last 16.3 ± 1.8 days of fetal life and randomly assigned.......5 weeks of age. Relative abundances of leptin and adiponectin mRNAs were different between adipose tissue sites and were significantly higher in subcutaneous than in perirenal and mesenteric tissues. Conclusion:Fetal life protein malnutrition in male mink, did not result in adaptive changes in the gene...

  12. Mechanism of attenuation of leptin signaling under chronic ligand stimulation

    Directory of Open Access Journals (Sweden)

    Bamberg-Lemper Simone

    2010-01-01

    Full Text Available Abstract Background Leptin is an adipocyte-derived hormone that acts via its hypothalamic receptor (LEPRb to regulate energy balance. A downstream effect essential for the weight-regulatory action of leptin is the phosphorylation and activation of the latent transcription factor STAT3 by LEPRb-associated Janus kinases (JAKs. Obesity is typically associated with chronically elevated leptin levels and a decreased ability of LEPRb to activate intracellular signal transduction pathways (leptin resistance. Here we have studied the roles of the intracellular tyrosine residues in the negative feedback regulation of LEPRb-signaling under chronic leptin stimulation. Results Mutational analysis showed that the presence of either Tyr985 and Tyr1077 in the intracellular domain of LEPRb was sufficient for the attenuation of STAT3 phosphorylation, whereas mutation of both tyrosines rendered LEPRb resistant to feedback regulation. Overexpression and RNA interference-mediated downregulation of suppressor of cytokine signaling 3 (SOCS3 revealed that both Tyr985 and Tyr1077 were capable of supporting the negative modulatory effect of SOCS3 in reporter gene assays. In contrast, the inhibitory effect of SOCS1 was enhanced by the presence of Tyr985 but not Tyr1077. Finally, the reduction of the STAT-phosphorylating activity of the LEPRb complex after 2 h of leptin stimulation was not accompanied by the dephosphorylation or degradation of LEPRb or the receptor-associated JAK molecule, but depended on Tyr985 and/or Tyr1077. Conclusions Both Tyr985 and Tyr1077 contribute to the negative regulation of LEPRb signaling. The inhibitory effects of SOCS1 and SOCS3 differ in the dependence on the tyrosine residues in the intracellular domain of LEPRb.

  13. Role of plasma adiponectin /C-reactive protein ratio in obesity and ...

    African Journals Online (AJOL)

    Background: Obesity is a modifiable risk factor for hypertension and T2D. Objective(s): We examined relations between fasting plasma adiponectin (ADIP), C-reactive protein (CRP) concentrations and markers of T2D in African Americans (AA). Methods: Fasting plasma ADIP, CRP, Insulin (IN), HOMA-IR, lipid profiles, body ...

  14. Circulating adipocyte fatty acid-binding protein, juvenile obesity, and metabolic syndrome

    NARCIS (Netherlands)

    Krzystek-Korpacka, Malgorzata; Patryn, Eliza; Bednarz-Misa, Iwona; Mierzchala, Magdalena; Hotowy, Katarzyna; Czapinska, Elzbieta; Kustrzeba-Wojcicka, Irena; Gamian, Andrzej; Noczynska, Anna

    2011-01-01

    Adipocyte fatty acid-binding protein (A-FABP) links obesity and metabolic syndrome (MetS) and might be targeted in future therapies. Its utility as a MetS biomarker has been suggested in adults but has not been examined in children/adolescents. Our objectives were to identify metabolic parameters

  15. Effect of soy protein on obesity-linked renal and pancreatic disorders in female rats

    International Nuclear Information System (INIS)

    Osman, H.F.; El-Sherbiny, E.M.

    2006-01-01

    The purpose of this study was to identify the effect of soy protein based diet on renal and pancreatic disorders in female obese rats. Animals assigned into group I in which 30 rats fed on a balanced diet. Group II contained 30 rats fed on a diet containing 30% fats for 4 weeks. At the end of the 4 th week, one-half of each group was treated as group III which contain 15 rats (half of group I) fed on diet containing 25% soy protein for 3 weeks and represents soy protein group, and the other half served as control. Group IV contained 15 rats (half of group II) fed on a diet containing 25% soy protein for 3 weeks and served as obese + soy protein group, and the other half fed on a normal balanced diet for 3 weeks and represents the obese group. Body weights of rats were recorded every week during the experimental period. Renal and pancreatic functions were measured as urea, creatinine, glomerular filtration rate (creatinine clearance), ammonia, sodium and potassium ions, total protein, albumin, globulin, glucose, insulin and alpha-amylase activity. Feeding with soy protein led to a very high significant increase in urea while creatinine was significantly decreased and creatinine clearance was significantly increased in the groups fed on soy protein. Ammonia concentration was increased in all groups and there was non-significant alteration in sodium and potassium ion concentrations. In soy protein groups (groups III and IV), total protein, albumin and globulin levels were increased. Glucose level was increased in obese rats and significantly decreased in groups III and IV. In group IV, insulin level was decreased which implicated to insulin excess in obesity. Soy protein decreased alpha-amylase activity in groups III and IV as compared to control rats. From these results, soy protein have a direct and protective effect on glomerular disorders and pancreatic secretions. This may be due to isoflavone contents in soy which can modulate the disturbance in metabolism

  16. Leptin and bone mineral density

    DEFF Research Database (Denmark)

    Morberg, Cathrine M.; Tetens, Inge; Black, Eva

    2003-01-01

    .001). An inverse relation between BMD adjusted for body weight and serum leptin emerged in both the control group (r = -0.186; P multiple linear regression, fat mass, lean body mass, and occupational physical activity were positively associated...

  17. Effect of nutritional recovery with soybean flour diet on body composition, energy balance and serum leptin concentration in adult rats

    Directory of Open Access Journals (Sweden)

    Boschero Antonio C

    2009-08-01

    Full Text Available Abstract Background Malnutrition in early life is associated with obesity in adulthood and soybean products may have a beneficial effect on its prevention and treatment. This study evaluated body composition, serum leptin and energy balance in adult rats subjected to protein restriction during the intrauterine stage and lactation and recovering on a soybean flour diet. Methods Five groups of the Wistar strain of albino rats were used: CC, offspring born to and suckled by mothers fed a control diet and fed the same diet after weaning; CS, offspring born to and suckled by mothers fed a control diet and fed a soybean diet with 17% protein after weaning; LL, offspring of mothers fed a low protein diet and fed the same diet after weaning; LC, offspring of mothers fed a low protein diet, but fed a control diet after weaning; LS, offspring of mothers fed a low protein diet, but fed a soybean diet with 17% protein after weaning. Food intake, body, perirenal and retroperitoneal adipose tissue were measured in grams. Leptin was quantified using the Enzyme Linked Immuno Sorbent Assay (ELISA and insulin by radioimmunoassay (RIA. Carcass composition was determined by chemical methods and energy expenditure was calculated by the difference between energy intake and carcass energy gain. Data were tested by analysis of variance (ANOVA. Results The LC and LS groups had higher energetic intake concerning body weight, lower energy expenditure, proportion of fat carcass and fat pads than CC and CS groups. The LS group showed reduced body weight gain and lower energy efficiency, which was reflected in less energy gain as protein and the proportion of carcass protein, and lower energy gain as lipid than in the LC groups, although both groups had eaten the same amount of diet and showed equal energy expenditure. Serum leptin did not differ among groups and was unrelated to food or energy intake and energy expenditure. Serum insulin was higher in the LS than in the LC

  18. Differential regulation of lipid and protein metabolism in obese vs. lean subjects before and after a 72-h fast

    DEFF Research Database (Denmark)

    Bak, Ann Mosegaard; Møller, Andreas Buch; Vendelbo, Mikkel Holm

    2016-01-01

    release in obese subjects under basal and fasting conditions. We therefore studied nine lean and nine obese subjects twice, after 12 and 72 h of fasting, using measurements of mRNA and protein expression and phosphorylation of lipolytic and protein metabolic signaling molecules in fat and muscle together...... in obese subjects and, correspondingly, adipose tissue hormone-sensitive lipase (HSL) phosphorylation and mRNA and protein levels of the adipose triglyceride lipase (ATGL) coactivator CGI58 were decreased. Fasting resulted in higher HSL phosphorylations and lower protein levels of the ATGL inhibitor G0S2...

  19. Association of Adipocyte Fatty Acid–Binding Protein (FABP4 Level with Obesity in Women

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    Hussein Jasim AL-Harbi

    2017-02-01

    Full Text Available Adipocyte Fatty Acid–Binding Protein(FABP 4 is produced by mature adipocytes, cytoplasmic lipid protein carrier, 132 amino acid and secretion increases during adipogenesis. Chemerin is adipocytokine anewly discovered novel adipokine that regulates adipocyte metabolism and adipogenesis, is The aim of this study is to investigated the relationship of chemerin and FABP4 level with obesity and identifing the usefulness of waist circumference (WC, hip circumference , waist-to-hip ratio (WHR, body mass index (BMI,, and body fat percentage( BF% in screening obesity . Anthropometric data were collected for 180 healthy women with an age range 35-60 years, divided into four groups due to body mass index: normalweight (18.5-24.9 kg/m2, overweight (25-29.9 kg/m2 , obese (30-39.9 kg/m2 and morbid(≥ 40 kg/m2. The results revealed that FABP4 and Chemerin circulating concentration were significantly increased (P<0.01 in healthy morbid and obese adult women when compared with lean healthy (normal and over weight women also significant increase of A-FABP and Chemerin with the body mass index (BMI, waist hip ratio, hip circumference, waist circumference, and with BF percentage. According to these finding suggest that the circulating chemerin and A-FABP levels can be used as Prediction marker of overall fat mass and obesity in women.

  20. Effects of a moderately high-protein diet and interval aerobic training combined with strength-endurance exercise on markers of bone metabolism, microarchitecture and turnover in obese Zucker rats.

    Science.gov (United States)

    Nebot, Elena; Aparicio, Virginia A; Coll-Risco, Irene; Camiletti-Moirón, Daniel; Schneider, Johannes; Kapravelou, Garyfallia; Heimel, Patrick; Martínez, Rosario; Andrade, Ana; Slezak, Paul; Redl, Heinz; Porres, Jesús M; López-Jurado, María; Pietschmann, Peter; Aranda, Pilar

    2016-11-01

    Weight loss is a public health concern in obesity-related diseases such as metabolic syndrome, and the protein level of the diets seem to be crucial for the development and maintenance of bone. The nature of exercise and whether exercise in combination with moderately high-protein dietary interventions could protect against potential bone mass deficits remains unclear. To investigate the effects of a moderately high-protein diet and interval aerobic training combined with strength-endurance exercise (IASE) protocol on bone status, and to assess potential interaction effects (i.e. diet*IASE). Male Zucker fatty rats were randomized distributed into 4 groups (n=8): normoprotein+sedentary; normoprotein+exercise; moderately high-protein+sedentary, and moderately high-protein+exercise. Training groups conducted an IASE program, 5days/week for 2months. Markers of bone metabolism were measured in plasma. Parameters of bone mass and 3D outcomes for trabecular and cortical bone microarchitecture were assessed by micro-computed tomography. Femur length, plasma osteocalcin, sclerostin, osteoprotegerin, receptor activator of nuclear factor kappa-B ligand, insulin, leptin, PTH, uric acid and urinary phosphorus levels were lower in the moderately high-protein compared to the normoprotein groups (all, palkaline phosphatase, aspartate aminotransferase, alanine transaminase, and urinary uric acid concentrations, and cortical total volume (TV) and bone volume (BV) were higher in the moderately high-protein (all, palkaline phosphatase levels were lower in the exercise compared to the sedentary (both, peffective to enhance trabecular bone microarchitecture and BMD, and has a partial impact on cortical bone in obese rats. Nevertheless, they do not induce any alteration on the bone turnover markers. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Leptin increases prostate cancer aggressiveness.

    Science.gov (United States)

    López Fontana, Constanza M; Maselli, María E; Pérez Elizalde, Rafael F; Di Milta Mónaco, Nicolás A; Uvilla Recupero, Ana L; López Laur, José D

    2011-12-01

    Recent studies indicate that adipose tissue and adipocytokines might affect the development of prostate cancer (PCa). Leptin would have a stimulating effect on prostate cancer cells by inducing promotion and progression, whereas adiponectin would have a protective effect. The aim of this study was to determine the relation between body composition, leptin, and adiponectin levels with the prevalence and aggressiveness of PCa in men of Mendoza, Argentina. Seventy volunteers between 50 and 80 years (35 healthy men as control group and 35 with PCa) were selected. The PCa group was subclassified according to the Gleason Score (GS). Digital rectal examination, transrectal ultrasound, and prostatic biopsy were performed; PSA, testosterone, leptin, and adiponectin levels were determined; and a nutritional interview including anthropometric measurements and a food frequen