Functional Deficits Precede Structural Lesions in Mice With High-Fat Diet-Induced Diabetic Retinopathy.

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Rajagopal, Rithwick; Bligard, Gregory W; Zhang, Sheng; Yin, Li; Lukasiewicz, Peter; Semenkovich, Clay F

2016-04-01

Obesity predisposes to human type 2 diabetes, the most common cause of diabetic retinopathy. To determine if high-fat diet-induced diabetes in mice can model retinal disease, we weaned mice to chow or a high-fat diet and tested the hypothesis that diet-induced metabolic disease promotes retinopathy. Compared with controls, mice fed a diet providing 42% of energy as fat developed obesity-related glucose intolerance by 6 months. There was no evidence of microvascular disease until 12 months, when trypsin digests and dye leakage assays showed high fat-fed mice had greater atrophic capillaries, pericyte ghosts, and permeability than controls. However, electroretinographic dysfunction began at 6 months in high fat-fed mice, manifested by increased latencies and reduced amplitudes of oscillatory potentials compared with controls. These electroretinographic abnormalities were correlated with glucose intolerance. Unexpectedly, retinas from high fat-fed mice manifested striking induction of stress kinase and neural inflammasome activation at 3 months, before the development of systemic glucose intolerance, electroretinographic defects, or microvascular disease. These results suggest that retinal disease in the diabetic milieu may progress through inflammatory and neuroretinal stages long before the development of vascular lesions representing the classic hallmark of diabetic retinopathy, establishing a model for assessing novel interventions to treat eye disease. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Photobiomodulation Mitigates Diabetes-Induced Retinopathy by Direct and Indirect Mechanisms: Evidence from Intervention Studies in Pigmented Mice.

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Alexandra Saliba

Full Text Available Daily application of far-red light from the onset of diabetes mitigated diabetes-induced abnormalities in retinas of albino rats. Here, we test the hypothesis that photobiomodulation (PBM is effective in diabetic, pigmented mice, even when delayed until weeks after onset of diabetes. Direct and indirect effects of PBM on the retina also were studied.Diabetes was induced in C57Bl/6J mice using streptozotocin. Some diabetics were exposed to PBM therapy (4 min/day; 670 nm daily. In one study, mice were diabetic for 4 weeks before initiation of PBM for an additional 10 weeks. Retinal oxidative stress, inflammation, and retinal function were measured. In some mice, heads were covered with a lead shield during PBM to prevent direct illumination of the eye, or animals were treated with an inhibitor of heme oxygenase-1. In a second study, PBM was initiated immediately after onset of diabetes, and administered daily for 2 months. These mice were examined using manganese-enhanced MRI to assess effects of PBM on transretinal calcium channel function in vivo.PBM intervention improved diabetes-induced changes in superoxide generation, leukostasis, expression of ICAM-1, and visual performance. PBM acted in part remotely from the retina because the beneficial effects were achieved even with the head shielded from the light therapy, and because leukocyte-mediated cytotoxicity of retinal endothelial cells was less in diabetics treated with PBM. SnPP+PBM significantly reduced iNOS expression compared to PBM alone, but significantly exacerbated leukostasis. In study 2, PBM largely mitigated diabetes-induced retinal calcium channel dysfunction in all retinal layers.PBM induces retinal protection against abnormalities induced by diabetes in pigmented animals, and even as an intervention. Beneficial effects on the retina likely are mediated by both direct and indirect mechanisms. PBM is a novel non-pharmacologic treatment strategy to inhibit early changes of diabetic

Immunomodulatory and Antidiabetic Effects of a New Herbal Preparation (HemoHIM on Streptozotocin-Induced Diabetic Mice

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Jong-Jin Kim

2014-01-01

Full Text Available HemoHIM (a new herbal preparation of three edible herbs: Angelica gigas Nakai, Cnidium officinale Makino, and Paeonia japonica Miyabe was developed to protect immune, hematopoietic, and self-renewal tissues against radiation. This study determined whether or not HemoHIM could alter hyperglycemia and the immune response in diabetic mice. Both nondiabetic and diabetic mice were orally administered HemoHIM (100 mg/kg once a day for 4 weeks. Diabetes was induced by single injection of streptozotocin (STZ, 200 mg/kg, i.p.. In diabetic mice, HemoHIM effectively improved hyperglycemia and glucose tolerance compared to the diabetic control group as well as elevated plasma insulin levels with preservation of insulin staining in pancreatic β-cells. HemoHIM treatment restored thymus weight, white blood cells, lymphocyte numbers, and splenic lymphocyte populations (CD4+ T and CD8+ T, which were reduced in diabetic mice, as well as IFN-γ production in response to Con A stimulation. These results indicate that HemoHIM may have potential as a glucose-lowering and immunomodulatory agent by enhancing the immune function of pancreatic β-cells in STZ-induced diabetic mice.

Effect of Vaccinium bracteatum Thunb. leaves extract on blood glucose and plasma lipid levels in streptozotocin-induced diabetic mice.

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Wang, Li; Zhang, Xue Tong; Zhang, Hai Yan; Yao, Hui Yuan; Zhang, Hui

2010-08-09

To investigate the hypoglycemic effects of Vaccinium bracteatum Thunb. leaves (VBTL) extract in streptozotocin-induced diabetic mice. After administration of VBTL extract for 4 weeks, the body weight, organ weight, blood glucose (BG), insulin and plasma lipid levels of streptozotocin-induced diabetic mice were measured. Body weights of diabetic mice treated with VBTL extract were partly recovered. The BG levels of AEG (diabetic mice treated with VBTL aqueous extract) were reduced to 91.52 and 85.82% at week 2 and week 4, respectively (P0.05). The insulin levels of AEG and EEG were obviously higher (P<0.05) than those of MC (diabetic mice in model control group). Comparing with MC, AEG and EEG had significantly lower (P<0.05) TC or TG levels and similar HDL-cholesterol or LDL-cholesterol levels. In comparison with non-diabetic control mice, AEG had similar plasma lipid levels except higher LDL-cholesterol level, while EEG had higher TC, TG and LDL-cholesterol levels and lower HDL-cholesterol levels. Both aqueous and ethanolic extract of VBTL possess a potential hypoglycemic effect in streptozotocin-induced diabetic mice. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

Anti-Diabetic Effects of Phenolic Extract from Rambutan Peels (Nephelium lappaceum) in High-Fat Diet and Streptozotocin-Induced Diabetic Mice.

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Ma, Qingyu; Guo, Yan; Sun, Liping; Zhuang, Yongliang

2017-07-26

Recent studies have shown that rambutan peel phenolic (RPP) extract demonstrate high antioxidant and antiglycation activities in vitro and in vivo. This study further evaluated the anti-diabetic activity of RPP in a mouse model of Type II diabetes induced by streptozotocin combined with high-fat diet. Results showed that RPP increased the body weight and reduced the fasting blood glucose level of the diabetic mice. RPP significantly reduced the serum levels of total cholesterol, triglyceride, creatinine, and glycated serum protein in diabetic mice in a dose-dependent manner. Glycogen content in mice liver was recovered by RPP, which further increased the activity of superoxide dismutase and glutathione peroxidase and reduced lipid peroxidation in diabetic mice. Histological analysis showed that RPP effectively protected the tissue structure of the liver, kidney, and pancreas. In addition, RPP decreased the mesangial index and inhibited the expression of TGF-β in the kidney of diabetic mice.

Urtica dioica modulates hippocampal insulin signaling and recognition memory deficit in streptozotocin induced diabetic mice.

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Patel, Sita Sharan; Gupta, Sahil; Udayabanu, Malairaman

2016-06-01

Diabetes mellitus has been associated with functional abnormalities in the hippocampus and performance of cognitive function. Urtica dioica (UD) has been used in the treatment of diabetes. In our previous report we observed that UD extract attenuate diabetes mediated associative and spatial memory dysfunction. The present study aimed to evaluate the effect of UD extract on mouse model of diabetes-induced recognition memory deficit and explore the possible mechanism behind it. Streptozotocin (STZ) (50 mg/kg, i.p. consecutively for 5 days) was used to induce diabetes followed by UD extract (50 mg/kg, oral) or rosiglitazone (ROSI) (5 mg/kg, oral) administration for 8 weeks. STZ induced diabetic mice showed significant decrease in hippocampal insulin signaling and translocation of glucose transporter type 4 (GLUT4) to neuronal membrane resulting in cognitive dysfunction and hypolocomotion. UD treatment effectively improved hippocampal insulin signaling, glucose tolerance and recognition memory performance in diabetic mice, which was comparable to ROSI. Further, diabetes mediated oxidative stress and inflammation was reversed by chronic UD or ROSI administration. UD leaves extract acts via insulin signaling pathway and might prove to be effective for the diabetes mediated central nervous system complications.

Early atherosclerosis and vascular inflammation in mice with diet-induced type 2 diabetes

DEFF Research Database (Denmark)

Bartels, E D; Bang, C A; Nielsen, L B

2009-01-01

and the median lesion area was 8.0 times higher than in fat-fed wild-type mice (P = 0.001). Intracellular adhesion molecule-1 staining of the aortic endothelium was most pronounced in the fat-fed apoB transgenic mice. CONCLUSIONS: Our findings suggest that diet-induced type 2 diabetes causes early......BACKGROUND: Obesity and type 2 diabetes increase the risk of atherosclerosis. It is unknown to what extent this reflects direct effects on the arterial wall or secondary effects of hyperlipidaemia. MATERIALS AND METHODS: The effect of obesity and type 2 diabetes on the development...

In Vivo Hypoglycemic Effect of Kigelia africana (Lam): Studies With Alloxan-Induced Diabetic Mice.

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Njogu, Stephen M; Arika, Wycliffe M; Machocho, Alex K; Ngeranwa, Joseph J N; Njagi, Eliud N M

2018-01-01

The claims by the traditional herbal medicine practitioners that Kigelia africana has bioactivity against several diseases, including diabetes mellitus, were investigated in this study. Type I diabetes mellitus was induced in mice by intraperitoneal administration of alloxan monohydrate followed by treatment with the therapeutic doses of the aqueous and ethyl acetate leaf extract of K africana to the experimentally diabetic mice. The treatment effects were compared with the normal control, diabetic control, and diabetic control rats treated with a standard antidiabetic drugs (insulin administered intraperitoneally at 1 IU/kg body weight in 0.1 mL physiological saline or glibenclamide administered orally at 3 mg/kg body weight in 0.1 mL physiological saline). Phytochemical composition of the leaf extract was assessed using standard procedures and mineral elements assessed using atomic absorption spectrophotometry and total reflection X-ray fluorescence system. Oral and intraperitoneal administration of the aqueous and ethyl acetate leaf extract caused a statistically significant dose-independent reduction in plasma glucose level in alloxan-induced diabetic mice. The observed hypoglycemic activity of this plant extract could be attributed to the observed phytochemicals and trace elements, which have been associated with exhibiting antidiabetic properties. Therefore, the data appear to support the hypoglycemic effects of K africana validating its folkloric usage.

Portulaca oleracea L. alleviates liver injury in streptozotocin-induced diabetic mice

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Peng, Hao; Gu, Wei; Li, Min; Chen, Zhe

2018-01-01

Purslane is a widespread succulent herb that exhibits various pharmacological effects. The purpose of this study was to evaluate the protective effect of Portulaca oleracea L. (purslane) on streptozotocin-induced diabetes in mice. Oral glucose-tolerance tests were carried out to assess blood glucose levels and body weight and food intake were recorded. The biochemical parameters anti-aspartate aminotransferase, alanine aminotransferase, insulin, triglycerides, total cholesterol, IL-6, IL-1β, and TNFα were also measured. The pathological condition of liver tissues were examined by hematoxylin–eosin staining. Rho, ROCK1, ROCK2, NFκBp65, p-NFκBp65, IκBα, and p-IκBα expression in liver tissue were analyzed by Western blot. Purslane increased body weight and decreased food intake. Purslane also significantly reduced concentrations of glucose, anti-aspartate aminotransferase, alanine aminotransferase, triglycerides, total cholesterol, IL-6, IL-1β, and TNFα in serum. Serum insulin was elevated with purslane treatment. In addition, pathologic liver changes in diabetic mice were also alleviated by purslane. Obtained data revealed that purslane restored the levels of Rho–NFκB signaling-related proteins in comparison with those of diabetic mice. Above all, it can be assumed that purslane might play a positive role in regulating streptozotocin-induced liver injury through suppressing the Rho–NFκB pathway. PMID:29343942

Rauwolfia serpentina improves altered glucose and lipid homeostasis in fructose-induced type 2 diabetic mice.

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Azmi, Muhammad Bilal; Qureshi, Shamim A

2016-09-01

Rauwolfia serpentina is well-reported in traditional medicines for the treatment of hypertensive and neurological disorders. However, its antidiabetic potential has been currently described in both alloxan-treated and normoglycemic mice. Present effort was carried out to investigate the effect of methanol root extract (MREt) of R.serpentina in fructose-induced type 2 diabetic mice. Experimental mice were grouped into normal control (distilled water 1ml/kg) and fructose-induced type 2 diabetic groups (10% fructose 1 ml/kg).The second group sub-divided into negative (0.05% DMSO 1ml/kg) control, positive (pioglitazone 15mg/kg) control and three test groups (MREt 10, 30 & 60 mg/kg). Each treatment was given orally for 14 days consecutively then mice were sacrificed in order to collect serum and liver samples to analyze physical, biochemical as well as hematological markers. MREt significantly improved percent body weight and glycemic change along with serum insulin, total cholesterol (TC), triglycerides (TG), low density lipoprotein (LDL-c), very low-density lipoprotein (VLDL-c), high-density lipoprotein-cholesterols (HDL-c), total hemoglobin, glycosylated hemoglobin, hepatic glycogen, coronary risk and fasting insulin resistance indices while suppressed down the activity of 3-hydroxy-3-methylglutaryl Coenzyme A reductase enzyme in test groups when compared with diabetic controls. The present findings conclude that MREt of R. serpentina can effectively betters the carbohydrate and lipid homeostasis by either inhibiting fructose absorption in intestine or decreasing insulin resistance in fructose-induced type 2 diabetic mice.

Ameliorative Effect of Hexane Extract of Phalaris canariensis on High Fat Diet-Induced Obese and Streptozotocin-Induced Diabetic Mice

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Rosa Martha Perez Gutierrez

2014-01-01

Full Text Available Obesity is one of the major factors to increase various disorders like diabetes. The present paper emphasizes study related to the antiobesity effect of Phalaris canariensis seeds hexane extract (Al-H in high-fat diet- (HFD- induced obese CD1 mice and in streptozotocin-induced mild diabetic (MD and severely diabetic (SD mice.AL-H was orally administered to MD and SD mice at a dose of 400 mg/kg once a day for 30 days, and a set of biochemical parameters were studied: glucose, cholesterol, triglycerides, lipid peroxidation, liver and muscle glycogen, ALP, SGOT, SGPT, glucose-6-phosphatase, glucokinase, hexokinase, SOD, CAT, GSH, GPX activities, and the effect on insulin level. HS-H significantly reduced the intake of food and water and body weight loss as well as levels of blood glucose, serum cholesterol, triglyceride, lipoprotein, oxidative stress, showed a protective hepatic effect, and increased HDL-cholesterol, serum insulin in diabetic mice. The mice fed on the high-fat diet and treated with AL-H showed inhibitory activity on the lipid metabolism decreasing body weight and weight of the liver and visceral adipose tissues and cholesterol and triglycerides in the liver. We conclude that AL-H can efficiently reduce serum glucose and inhibit insulin resistance, lipid abnormalities, and oxidative stress in MD and SD mice. Our results demonstrate an antiobesity effect reducing lipid droplet accumulation in the liver, indicating that its therapeutic properties may be due to the interaction plant components soluble in the hexane extract, with any of the multiple targets involved in obesity and diabetes pathogenesis.

Ameliorative Effect of Hexane Extract of Phalaris canariensis on High Fat Diet-Induced Obese and Streptozotocin-Induced Diabetic Mice.

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Perez Gutierrez, Rosa Martha; Madrigales Ahuatzi, Diana; Horcacitas, Maria Del Carmen; Garcia Baez, Efren; Cruz Victoria, Teresa; Mota-Flores, Jose Maria

2014-01-01

Obesity is one of the major factors to increase various disorders like diabetes. The present paper emphasizes study related to the antiobesity effect of Phalaris canariensis seeds hexane extract (Al-H) in high-fat diet- (HFD-) induced obese CD1 mice and in streptozotocin-induced mild diabetic (MD) and severely diabetic (SD) mice.AL-H was orally administered to MD and SD mice at a dose of 400 mg/kg once a day for 30 days, and a set of biochemical parameters were studied: glucose, cholesterol, triglycerides, lipid peroxidation, liver and muscle glycogen, ALP, SGOT, SGPT, glucose-6-phosphatase, glucokinase, hexokinase, SOD, CAT, GSH, GPX activities, and the effect on insulin level. HS-H significantly reduced the intake of food and water and body weight loss as well as levels of blood glucose, serum cholesterol, triglyceride, lipoprotein, oxidative stress, showed a protective hepatic effect, and increased HDL-cholesterol, serum insulin in diabetic mice. The mice fed on the high-fat diet and treated with AL-H showed inhibitory activity on the lipid metabolism decreasing body weight and weight of the liver and visceral adipose tissues and cholesterol and triglycerides in the liver. We conclude that AL-H can efficiently reduce serum glucose and inhibit insulin resistance, lipid abnormalities, and oxidative stress in MD and SD mice. Our results demonstrate an antiobesity effect reducing lipid droplet accumulation in the liver, indicating that its therapeutic properties may be due to the interaction plant components soluble in the hexane extract, with any of the multiple targets involved in obesity and diabetes pathogenesis.

Therapeutic Effects of Bupleurum Polysaccharides in Streptozotocin Induced Diabetic Mice.

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Lingyu Pan

Full Text Available Diabetes mellitus is related to low-grade chronic inflammation and oxidative stress. Bupleurum Polysaccharides (BPs, isolated from Bupleurum smithii var. parvifolium has anti-inflammatory and anti-oxidative properties. However, little is known about its therapeutic effects on diabetes. In this experiment, the effects of BPs on alleviation of diabetes and the underlying mechanisms were investigated. Diabetic mice model was established via successive intraperitoneal injections of streptozotocin (100 mg/kg body weight for two days. Mice with blood glucose levels higher than 16.8mmol/L were selected for experiments. The diabetic mice were orally administered with BPs (30 and 60 mg/kg once a day for 35 days. BPs not only significantly decreased levels of blood glucose, but also increased those of serum insulin and liver glycogen in diabetic mice compared to model mice. Additionally, BPs adminstration improved the insulin expression and suppressed the apoptosis in pancreas of the diabetic mice. Histopathological observations further demonstrated that BPs protected the pancreas and liver from oxidative and inflammatory damages. These results suggest that BPs protect pancreatic β cells and liver hepatocytes and ameliorate diabetes, which is associated with its anti-oxidative and anti-inflammatory properties.

[Nicorandil improves cognitive dysfunction in mice with streptozotocin-induced diabetes].

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Yan, Wen-Hui; Zhang, Chun-Xi; Xing, Tong; Gong, Xue; Yang, Yu-Xuan; Li, Yi-Nuo; Liu, Xuan; Ayijiang, Jiamaliding; Yu, Ye; Zhang, Meng; Chen, Li-Na

2018-04-20

To observe the protective effects of potassium channel opener nicorandil against cognitive dysfunction in mice with streptozotocin (STZ)-induced diabetes. C57BL/6J mouse models of type 1 diabetes mellitus (T1DM) were established by intraperitoneal injection of STZ and received daily treatment with intragastric administration of nicorandil or saline (model group) for 4 consecutive weeks, with normal C57BL/6J mice serving as control. Fasting blood glucose level was recorded every week and Morris water maze was used to evaluate the cognitive behavior of the mice in the 4th week. At the end of the experiment, the mice were sacrificed to observe the ultrastructural changes in the hippocampus and pancreas under transmission electron microscopy; the contents of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) in the hippocampus and SOD activity and MDA level in the brain tissue were determined. Compared with the control group, the model group showed significantly increased fasting blood glucose (P<0.001), significantly prolonged escape latency (P<0.05) and increased swimming distance (P<0.01) with ultrastructural damage of pancreatic β cells and in the hippocampus; GIP and GLP-1 contents in the hippocampus (P<0.01) and SOD activity in the brain were significantly decreased (P<0.05) and MDA content was significantly increased in the model group (P<0.05). Compared with the model group, nicorandil treatment did not cause significant changes in fasting blood glucose, but significantly reduced the swimming distance (P<0.05); nicorandil did not improve the ultrastructural changes in pancreatic β cells but obviously improved the ultrastructures of hippocampal neurons and synapses. Nicorandil also significantly increased the contents of GIP and GLP-1 in the hippocampus (P<0.05), enhanced SOD activity (P<0.05) and decreased MDA level (P<0.01) in the brain tissue. Nicorandil improves cognitive dysfunction in mice with STZ-induced diabetes by

Anti-Diabetic, Anti-Oxidant and Anti-Hyperlipidemic Activities of Flavonoids from Corn Silk on STZ-Induced Diabetic Mice.

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Zhang, Yan; Wu, Liying; Ma, Zhongsu; Cheng, Jia; Liu, Jingbo

2015-12-23

Corn silk is a well-known ingredient frequently used in traditional Chinese herbal medicines. This study was designed to evaluate the anti-diabetic, anti-oxidant and anti-hyperlipidemic activities of crude flavonoids extracted from corn silk (CSFs) on streptozotocin (STZ)-induced diabetic mice. The results revealed that treatment with 300 mg/kg or 500 mg/kg of CSFs significantly reduced the body weight loss, water consumption, and especially the blood glucose (BG) concentration of diabetic mice, which indicated their potential anti-diabetic activities. Serum total superoxide dismutase (SOD) and malondialdehyde (MDA) assays were also performed to evaluate the anti-oxidant effects. Besides, several serum lipid values including total cholesterol (TC), triacylglycerol (TG), low density lipoprotein cholesterol (LDL-C) were reduced and the high density lipoprotein cholesterol level (HDL-C) was increased. The anti-diabetic, anti-oxidant and anti-hyperlipidemic effect of the CSFs suggest a potential therapeutic treatment for diabetic conditions.

Capparis spinosa L. aqueous extract evokes antidiabetic effect in streptozotocin-induced diabetic mice

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Mohamed Eddouks

2017-02-01

Full Text Available Objective: As the aqueous extract of Capparis spinosa (CS possess antidiabetic effect, he present study aims to reveal the possible  mechanism of action of CS in diabetic mice.Materials and Methods: Both single and repeated oral administrations of aqueous extract of CS were performed in multi-low dose streptozotocin-induced (MLDS diabetic mice. Euglycemic hyperinsulinemic clamp was used in association with the endogenous glucose production (perfusion rate of 3-3H glucose to evaluate the effect of CS aqueous extract on insulin sensitivity.Results: Our study showed that aqueous extract of CS possess a potent hypoglycaemic activity in MLDS diabetic mice. Furthermore, the analysis perfusion of 3-3H glucose demonstrated  the parallel decrease of basal endogenous glucose production (EGP with the hypoglycaemic activity. EGP was lower in CS-Treated group when compared to the control group (p

Folic Acid Reduces Tau Phosphorylation by Regulating PP2A Methylation in Streptozotocin-Induced Diabetic Mice

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Zheng, Miaoyan; Zou, Chen; Li, Mengyue; Huang, Guowei; Gao, Yuxia; Liu, Huan

2017-01-01

High incidence rate of Alzheimer’s disease (AD) is observed in patients with type 2 diabetes. Aggregated β-amyloid (Aβ) and hyperphosphorylated tau are the hallmarks of AD. Hyperphosphorylated tau has been detected in diabetic animals as well as in diabetic patients. Folates mediate the transfer of one carbon unit, required in various biochemical reactions. The effect of folate on tau phosphorylation in diabetic models still remains unknown. In this study, we investigated the effect and mechanism of folic acid on hyperphosphorylation of tau in streptozotocin (STZ)-induced diabetic mice. Diabetic mice induced by STZ, at the age of 10 weeks, were administered with three levels of folic acid: folic acid-deficient diet, diet with normal folic acid content, and 120 μg/kg folic acid diet for 8 weeks. Levels of serum folate and blood glucose were monitored. Tau phosphorylation, protein phosphatase 2A (PP2A) methylation, and Glycogen synthase kinase 3β (GSK-3β) phosphorylation were detected using Western blot. The S-adenosyl methionine:S-adenosyl homocysteine ratio (SAM:SAH) in brain tissues was also determined. DNA methyltransferase (DNMT) mRNA expression levels were detected using real-time PCR. Folic acid reduced tau hyperphosphorylation at Ser396 in the brain of diabetes mellitus (DM) mice. In addition, PP2A methylation and DNMT1 mRNA expression were significantly increased in DM mice post folic acid treatment. GSK-3β phosphorylation was not regulated by folic acid administration. Folic acid can reduce tau phosphorylation by regulating PP2A methylation in diabetic mice. These results support that folic acid can serve as a multitarget neuronal therapeutic agent for treating diabetes-associated cognitive dysfunction. PMID:28422052

Hypoglycemic and hypolipidemic effects of triterpenoid-enriched Jamun (Eugenia jambolana Lam.) fruit extract in streptozotocin-induced type 1 diabetic mice.

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Xu, Jialin; Liu, Tingting; Li, Yuanyuan; Yuan, Chunhui; Ma, Hang; Seeram, Navindra P; Liu, Feifei; Mu, Yu; Huang, Xueshi; Li, Liya

2018-06-20

The edible berries of Eugenia jambolana Lam. (known as Jamun) are consumed in various parts of the world. Our previous studies revealed that a triterpenoid-enriched Jamun fruit extract (TJFE) showed beneficial effects on glucose homeostasis in non-diabetic mice. Herein, the anti-diabetic effects of TJFE (100 mg kg-1 by oral gavage for ten days) were evaluated in streptozotocin (STZ)-induced type 1 diabetic mice. TJFE significantly attenuated STZ-induced hyperglycemia and glucose intolerance, suppressed the abnormal elevation of hepatic gluconeogenesis, and improved dyslipidemia in the mice. Histopathology and mechanism-based studies revealed that TJFE preserved the architecture and function of pancreatic islets, attenuated insulin secretion deficiency, enhanced insulin/Akt signaling transduction, reduced lipogenic gene expression, and prevented the abnormal activation of Erk MAPK in the liver tissues of the STZ-induced diabetic mice. The current study adds to previously published data supporting the potential beneficial effects of this edible fruit on diabetes management.

Mitochondrial dysfunction contribute to diabetic neurotoxicity induced by streptozocin in mice: protective effect of Urtica dioica and pioglitazone.

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Shokrzadeh, Mohammad; Mirshafa, Atefeh; Yekta Moghaddam, Niusha; Birjandian, Behnoosh; Shaki, Fatemeh

2018-04-18

Uncontrolled chronic hyperglycemia in diabetic patients could result in various complications, including neurotoxicity. Urtica dioica L. (UD) is known for its hypoglycemic and antioxidant effects. In this study, we evaluated the efficacy of UD and pioglitazone (PIO) in reduction of neurotoxicity and oxidative stress in streptozocin-induced diabetic mice. Male mice were divided into seven groups: control, diabetic, dimethyl sulfoxide-treated control, PIO-treated, UD-treated, UD-PIO-treated, and vitamin E-treated. For induction of diabetes, streptozocin was injected in a single dose (65 mg/kg, i.p.). All treatments were performed for 5 weeks. Neurotoxicity was evaluated through hot plate and formalin test. Then, animals were killed, brain tissue was separated and the mitochondrial fraction was isolated with different centrifuge technique. Also, oxidative stress markers (reactive oxygen species, lipid peroxidation, protein carbonyl, glutathione) were measured in brain. Mitochondrial function was evaluated by MTT test in brain isolated mitochondria. Elevation of oxidative stress markers and mitochondrial damage were observed in diabetic mice compared to control group. Administration of PIO and UD ameliorated the oxidative stress and mitochondrial damage (p < 0.05) in diabetic mice. Also increase in pain score was shown in diabetic mice that treatment with UD and PIO diminished elevation of pain score in diabetic mice. Interestingly, simultaneous administration of PIO and UD showed synergism effect in attenuation of oxidative stress and hyperglycemia. UD showed a therapeutic potential for the attenuation of oxidative stress and diabetes-induced hyperglycemia that can be considered as co-treatment in treatment of diabetic neurotoxicity.

Immunomodulatory and Antidiabetic Effects of a New Herbal Preparation (HemoHIM) on Streptozotocin-Induced Diabetic Mice

OpenAIRE

Kim, Jong-Jin; Choi, Jina; Lee, Mi-Kyung; Kang, Kyung-Yun; Paik, Man-Jeong; Jo, Sung-Kee; Jung, Uhee; Park, Hae-Ran; Yee, Sung-Tae

2014-01-01

HemoHIM (a new herbal preparation of three edible herbs: Angelica gigas Nakai, Cnidium officinale Makino, and Paeonia japonica Miyabe) was developed to protect immune, hematopoietic, and self-renewal tissues against radiation. This study determined whether or not HemoHIM could alter hyperglycemia and the immune response in diabetic mice. Both nondiabetic and diabetic mice were orally administered HemoHIM (100 mg/kg) once a day for 4 weeks. Diabetes was induced by single injection of streptozo...

Suppressor of cytokine signaling 2 (SOCS2) deletion protects against multiple low dose streptozotocin-induced type 1 diabetes in adult male mice

DEFF Research Database (Denmark)

Alkharusi, Amira; Mirecki-Garrido, Mercedes; Ma, Zuheng

2016-01-01

Background: Diabetes type 1 is characterized by the failure of beta cells to produce insulin. Suppressor of cytokine signaling (SOCS) proteins are important regulators of the Janus kinase/signal transducer and activator of transcription (JAK-STAT) pathway. Previous studies have shown that GH can...... prevent the development of type I diabetes in mice and that SOCS2 deficiency mimics a state of increased GH sensitivity. Methodology: The elevated sensitivity of SOCS2-/- mice to GH and possibly to PRL was the rationale to analyze the effects of multiple low dose streptozotocin (MLDSTZ)-induced diabetes...... in SOCS2-/- mice. Results: We show that 6-month-old SOCS2-/- mice, but not 2-month-old mice, were less sensitive to MLDSTZ-induced diabetes, compared to controls. MLDSTZ treatment induced glucose intolerance in both SOCS2+/+ and SOCS2-/- mice, as shown by glucose tolerance tests, with SOCS2+/+ mice...

Anti-Diabetic, Anti-Oxidant and Anti-Hyperlipidemic Activities of Flavonoids from Corn Silk on STZ-Induced Diabetic Mice

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Yan Zhang

2015-12-01

Full Text Available Corn silk is a well-known ingredient frequently used in traditional Chinese herbal medicines. This study was designed to evaluate the anti-diabetic, anti-oxidant and anti-hyperlipidemic activities of crude flavonoids extracted from corn silk (CSFs on streptozotocin (STZ-induced diabetic mice. The results revealed that treatment with 300 mg/kg or 500 mg/kg of CSFs significantly reduced the body weight loss, water consumption, and especially the blood glucose (BG concentration of diabetic mice, which indicated their potential anti-diabetic activities. Serum total superoxide dismutase (SOD and malondialdehyde (MDA assays were also performed to evaluate the anti-oxidant effects. Besides, several serum lipid values including total cholesterol (TC, triacylglycerol (TG, low density lipoprotein cholesterol (LDL-C were reduced and the high density lipoprotein cholesterol level (HDL-C was increased. The anti-diabetic, anti-oxidant and anti-hyperlipidemic effect of the CSFs suggest a potential therapeutic treatment for diabetic conditions.

Petalonia improves glucose homeostasis in streptozotocin-induced diabetic mice

International Nuclear Information System (INIS)

Kang, Seong-Il; Jin, Young-Jun; Ko, Hee-Chul; Choi, Soo-Youn; Hwang, Joon-Ho; Whang, Ilson; Kim, Moo-Han; Shin, Hye-Sun; Jeong, Hyung-Bok; Kim, Se-Jae

2008-01-01

The anti-diabetic potential of Petalonia binghamiae extract (PBE) was evaluated in vivo. Dietary administration of PBE to streptozotocin (STZ)-induced diabetic mice significantly lowered blood glucose levels and improved glucose tolerance. The mode of action by which PBE attenuated diabetes was investigated in vitro using 3T3-L1 cells. PBE treatment stimulated 3T3-L1 adipocyte differentiation as evidenced by increased triglyceride accumulation. At the molecular level, peroxisome proliferator-activated receptor γ (PPARγ) and terminal marker protein aP2, as well as the mRNA of GLUT4 were up-regulated by PBE. In mature adipocytes, PBE significantly stimulated the uptake of glucose and the expression of insulin receptor substrate-1 (IRS-1). Furthermore, PBE increased PPARγ luciferase reporter gene activity in COS-1 cells. Taken together, these results suggest that the in vivo anti-diabetic effect of PBE is mediated by both insulin-like and insulin-sensitizing actions in adipocytes

In Vivo Hypoglycaemic Effect and Inhibitory Mechanism of the Branch Bark Extract of the Mulberry on STZ-Induced Diabetic Mice

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Hua-Yu Liu

2014-01-01

Full Text Available Branch bark extract (BBE derived from the mulberry cultivar Husang 32 (Morus multicaulis L. with aqueous alcohol solution has been investigated as an inhibitor of α-glycosidase in vitro. Mulberry BBE was orally administered to STZ-induced diabetic mice for three weeks, and it improved the weight gain and ameliorated the swelling of liver and kidney in diabetic mice. Obviously, mulberry BBE not only can reduce the abnormally elevated levels of serum insulin and ameliorate insulin resistance induced by STZ, but also it regulates dyslipidemia in diabetic mice. To understand this therapeutic effect and the regulatory mechanisms of BBE in diabetic mice, a qRT-PCR experiment was performed, indicating that the mulberry BBE can regulate the mRNA expression of glycometabolism genes in diabetic mice, including glucose-6-phosphatase (G6Pase, glucokinase (GCK, and phosphoenolpyruvate carboxykinase (PEPCK, thereby regulating sugar metabolism and reducing the blood glucose level in diabetic mice. The mulberry BBE can increase the mRNA expression of the genes Ins1, Ins2 and pancreatic duodenal homeobox-1 (PDX-1 and may decrease the insulin resistance in diabetic mice. Those results provide an important basis for making the best use of mulberry branch resources and producing biomedical drugs with added value.

Far infra-red therapy promotes ischemia-induced angiogenesis in diabetic mice and restores high glucose-suppressed endothelial progenitor cell functions

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Huang Po-Hsun

2012-08-01

Full Text Available Abstract Background Far infra-red (IFR therapy was shown to exert beneficial effects in cardiovascular system, but effects of IFR on endothelial progenitor cell (EPC and EPC-related vasculogenesis remain unclear. We hypothesized that IFR radiation can restore blood flow recovery in ischemic hindlimb in diabetic mice by enhancement of EPCs functions and homing process. Materials and methods Starting at 4 weeks after the onset of diabetes, unilateral hindlimb ischemia was induced in streptozotocine (STZ-induced diabetic mice, which were divided into control and IFR therapy groups (n = 6 per group. The latter mice were placed in an IFR dry sauna at 34°C for 30 min once per day for 5 weeks. Results Doppler perfusion imaging demonstrated that the ischemic limb/normal side blood perfusion ratio in the thermal therapy group was significantly increased beyond that in controls, and significantly greater capillary density was seen in the IFR therapy group. Flow cytometry analysis showed impaired EPCs (Sca-1+/Flk-1+ mobilization after ischemia surgery in diabetic mice with or without IFR therapy (n = 6 per group. However, as compared to those in the control group, bone marrow-derived EPCs differentiated into endothelial cells defined as GFP+/CD31+ double-positive cells were significantly increased in ischemic tissue around the vessels in diabetic mice that received IFR radiation. In in-vitro studies, cultured EPCs treated with IFR radiation markedly augmented high glucose-impaired EPC functions, inhibited high glucose-induced EPC senescence and reduced H2O2 production. Nude mice received human EPCs treated with IFR in high glucose medium showed a significant improvement in blood flow recovery in ischemic limb compared to those without IFR therapy. IFR therapy promoted blood flow recovery and new vessel formation in STZ-induced diabetic mice. Conclusions Administration of IFR therapy promoted collateral flow recovery and new vessel formation in STZ-induced

Anti-diabetic effect of balanced deep-sea water and its mode of action in high-fat diet induced diabetic mice.

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Ha, Byung Geun; Shin, Eun Ji; Park, Jung-Eun; Shon, Yun Hee

2013-10-29

In this study, we investigated the effects of balanced deep-sea water (BDSW) on hyperglycemia and glucose intolerance in high-fat diet (HFD)-induced diabetic C57BL/6J mice. BDSW was prepared by mixing deep-sea water (DSW) mineral extracts and desalinated water to give a final hardness of 500-2000. Mice given an HFD with BDSW showed lowered fasting plasma glucose levels compared to HFD-fed mice. Oral and intraperitoneal glucose tolerance tests showed that BDSW improves impaired glucose tolerance in HFD-fed mice. Histopathological evaluation of the pancreas showed that BDSW recovers the size of the pancreatic islets of Langerhans, and increases the secretion of insulin and glucagon in HFD-fed mice. Quantitative reverse transcription polymerase chain reaction results revealed that the expression of hepatic genes involved in glucogenesis, glycogenolysis and glucose oxidation were suppressed, while those in glucose uptake, β-oxidation, and glucose oxidation in muscle were increased in mice fed HFD with BDSW. BDSW increased AMP-dependent kinase (AMPK) phosphorylation in 3T3-L1 pre- and mature adipocytes and improved impaired AMPK phosphorylation in the muscles and livers of HFD-induced diabetic mice. BDSW stimulated phosphoinositol-3-kinase and AMPK pathway-mediated glucose uptake in 3T3-L1 adipocytes. Taken together, these results suggest that BDSW has potential as an anti-diabetic agent, given its ability to suppress hyperglycemia and improve glucose intolerance by increasing glucose uptake.

Effect of pregabalin on contextual memory deficits and inflammatory state-related protein expression in streptozotocin-induced diabetic mice.

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Sałat, Kinga; Gdula-Argasińska, Joanna; Malikowska, Natalia; Podkowa, Adrian; Lipkowska, Anna; Librowski, Tadeusz

2016-06-01

Diabetes mellitus is a metabolic disease characterized by hyperglycemia due to defects in insulin secretion or its action. Complications from long-term diabetes consist of numerous biochemical, molecular, and functional tissue alterations, including inflammation, oxidative stress, and neuropathic pain. There is also a link between diabetes mellitus and vascular dementia or Alzheimer's disease. Hence, it is important to treat diabetic complications using drugs which do not aggravate symptoms induced by the disease itself. Pregabalin is widely used for the treatment of diabetic neuropathic pain, but little is known about its impact on cognition or inflammation-related proteins in diabetic patients. Thus, this study aimed to evaluate the effect of intraperitoneal (ip) pregabalin on contextual memory and the expression of inflammatory state-related proteins in the brains of diabetic, streptozotocin (STZ)-treated mice. STZ (200 mg/kg, ip) was used to induce diabetes mellitus. To assess the impact of pregabalin (10 mg/kg) on contextual memory, a passive avoidance task was applied. Locomotor and exploratory activities in pregabalin-treated diabetic mice were assessed by using activity cages. Using Western blot analysis, the expression of cyclooxygenase-2 (COX-2), cytosolic prostaglandin E synthase (cPGES), nuclear factor (erythroid-derived 2)-like 2 (Nrf2), nuclear factor-ĸB (NF-ĸB) p50 and p65, aryl hydrocarbon receptor (AhR), as well as glucose transporter type-4 (GLUT4) was assessed in mouse brains after pregabalin treatment. Pregabalin did not aggravate STZ-induced learning deficits in vivo or influence animals' locomotor activity. We observed significantly lower expression of COX-2, cPGES, and NF-κB p50 subunit, and higher expression of AhR and Nrf2 in the brains of pregabalin-treated mice in comparison to STZ-treated controls, which suggested immunomodulatory and anti-inflammatory effects of pregabalin. Antioxidant properties of pregabalin in the brains of

Cannabinoid 2 Receptor Agonist Improves Systemic Sensitivity to Insulin in High-Fat Diet/Streptozotocin-Induced Diabetic Mice

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Xiuyuan Zhang

2016-12-01

Full Text Available Background/Aims: The endocannabinoid signalling (ECS system has been known to regulate glucose homeostasis. Previous studies have suggested that the cannabinoid 2 (CB2 receptor may play a regulatory role on insulin secretion, immune modulation and insulin resistance. Given that diabetes and insulin resistance are attributable to elevated inflammatory tone, we investigated the role of CB2 receptor on glucose tolerance and insulin sensitivity in high-fat diet (HFD/streptozotocin (STZ-induced mice. Methods: Diabetes was induced in male ICR mice by HFD/STZ and exposed to a CB2 receptor agonist, SER601, for 2- or 4-weeks via subcutaneous implantation of osmotic minipumps. Glucose and insulin tolerance tests were performed at the end of treatment. Islets were isolated for assessment of β-cell function. Pancreases and skeletal muscles were also obtained for histological analyses. Results: Despite a lack of impact on glucose tolerance, substantial improvement on insulin sensitivity was observed in SER601-treated mice, which could partly be attributed to improved islet β-cell function, shown as increased glucose-induced insulin secretion and insulin content. No changes on islet macrophage infiltration or skeletal muscle fat deposition were detectable from SER601-treated mice. However, a major decrease in body weight was recorded at the end of 4-week SER601 exposure, accompanied by a lack of epididymal adipose mass in SER601-treated mice. Conclusion: Our data suggest a lipolytic role of SER601 in HFD/STZ-induced diabetic mice, which results in significant improvement of systemic insulin sensitivity. Thus, the CB2 receptor may be considered a promising target for therapeutic development against insulin resistance and obesity-related diabetes.

Portulaca oleracea L. alleviates liver injury in streptozotocin-induced diabetic mice

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Zheng G

2017-12-01

Full Text Available Guoyin Zheng,1,* Fengfeng Mo,2,* Chen Ling,3,* Hao Peng,1 Wei Gu,1 Min Li,2 Zhe Chen1 1Department of Traditional Chinese Medicine, Changhai Hospital, 2Department of Military Hygiene, Second Military Medical University, 3Department of Biology, School of Life Science, Fudan University, Shanghai, People’s Republic of China *These authors contributed equally to this work Abstract: Purslane is a widespread succulent herb that exhibits various pharmacological effects. The purpose of this study was to evaluate the protective effect of Portulaca oleracea L. (purslane on streptozotocin-induced diabetes in mice. Oral glucose-tolerance tests were carried out to assess blood glucose levels and body weight and food intake were recorded. The biochemical parameters anti-aspartate aminotransferase, alanine aminotransferase, insulin, triglycerides, total cholesterol, IL-6, IL-1β, and TNFα were also measured. The pathological condition of liver tissues were examined by hematoxylin–eosin staining. Rho, ROCK1, ROCK2, NFκBp65, p-NFκBp65, IκBα, and p-IκBα expression in liver tissue were analyzed by Western blot. Purslane increased body weight and decreased food intake. Purslane also significantly reduced concentrations of glucose, anti-aspartate aminotransferase, alanine ­aminotransferase, triglycerides, total cholesterol, IL-6, IL-1β, and TNFα in serum. Serum insulin was elevated with purslane treatment. In addition, pathologic liver changes in diabetic mice were also alleviated by purslane. Obtained data revealed that purslane restored the levels of Rho–NFκB signaling-related proteins in comparison with those of diabetic mice. Above all, it can be assumed that purslane might play a positive role in regulating streptozotocin-induced liver injury through suppressing the Rho–NFκB pathway. Keywords: Portulaca oleracea L., diabetes, liver injury, Rho–NFκB

Contribution of neural cell death to depressive phenotypes of streptozotocin-induced diabetic mice

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Cheng Chen

2014-06-01

Full Text Available Major depression disorder (MDD or depression is highly prevalent in individuals with diabetes, and the depressive symptoms are more severe and less responsive to antidepressant therapies in these patients. The underlying mechanism is little understood. We hypothesized that the pathophysiology of comorbid depression was more complex than that proposed for MDD and that neural cell death played a role in the disease severity. To test this hypothesis, we generated streptozotocin (STZ-induced diabetic mice. These mice had blood glucose levels threefold above controls and exhibited depressive phenotypes as judged by a battery of behavioral tests, thus confirming the comorbidity in mice. Immunohistological studies showed markedly increased TUNEL-positive cells in the frontal cortex and hippocampus of the comorbid mice, indicating apoptosis. This finding was supported by increased caspase-3 and decreased Bcl-2 proteins in these brain regions. In addition, the serum brain-derived neurotrophic factor (BDNF level of comorbid mice was reduced compared with controls, further supporting the neurodegenerative change. Mechanistic analyses showed an increased expression of mitochondrial fission genes fission protein 1 (Fis1 and dynamin-related protein 1 (Drp1, and a decreased expression of mitochondrial fusion genes mitofusin 1 (Mfn1, mitofusin 2 (Mfn2 and optical atrophy 1 (Opa1. Representative assessment of the proteins Drp1 and Mfn2 mirrored the mRNA changes. The data demonstrated that neural cell death was associated with the depressive phenotype of comorbid mice and that a fission-dominant expression of genes and proteins mediating mitochondrial dynamics played a role in the hyperglycemia-induced cell death. The study provides new insight into the disease mechanism and could aid the development of novel therapeutics aimed at providing neuroprotection by modulating mitochondrial dynamics to treat comorbid depression with diabetes.

Mechanisms of Mycobacterium avium-induced resistance against insulin-dependent diabetes mellitus (IDDM) in non-obese diabetic (NOD) mice: role of Fas and Th1 cells.

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Martins, T C; Aguas, A P

1999-02-01

NOD mice spontaneously develop autoimmune diabetes. One of the manipulations that prevent diabetes in NOD mice is infection with mycobacteria or immunization of mice with mycobacteria-containing adjuvant. Infection of NOD mice with Mycobacterium avium, done before the mice show overt diabetes, results in permanent protection of the animals from diabetes and this protective effect is associated with increased numbers of CD4+ T cells and B220+ B cells. Here, we investigate whether the M. avium-induced protection of NOD mice from diabetes was associated with changes in the expression of Fas (CD95) and FasL by immune cells, as well as alterations in cytotoxic activity, interferon-gamma (IFN-gamma) and IL-4 production and activation of T cells of infected animals. Our data indicate that protection of NOD mice from diabetes is a Th1-type response that is mediated by up-regulation of the Fas-FasL pathway and involves an increase in the cytotoxicity of T cells. These changes are consistent with induction by the infection of regulatory T cells with the ability of triggering deletion or anergy of peripheral self-reactive lymphocytes that cause the autoimmune disease of NOD mice.

Shifts in renin-angiotensin system components, angiogenesis, and oxidative stress-related protein expression in the lamina cribrosa region of streptozotocin-induced diabetic mice.

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Qian, Xiaobing; Lin, Leilei; Zong, Yao; Yuan, Yongguang; Dong, Yanmin; Fu, Yue; Shao, Wanwen; Li, Yujie; Gao, Qianying

2018-03-01

This study aimed to analyse shifts in renin-angiotensin system (RAS) components, angiogenesis, and oxidative stress-related protein expression in the lamina cribrosa (LC) region in streptozotocin (STZ)-induced diabetic mice. Six months after diabetes induction, the retinal vessels of male C57BL/6 J mice were observed by colour photography, fundus fluorescein angiography (FFA), and immunofluorescent staining following incubation with CD31. Immunofluorescence for glial fibrillary acidic protein (GFAP), alpha-smooth muscle actin (α-SMA),and NG2 was also performed. Angiotensin-converting enzyme 1 (ACE1), angiotensin II type I receptor (AT1R), renin, hypoxia-inducible factor 1-alpha (HIF-1α), vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor 2 (VEGFR2), and haeme oxygenase 1 (HO-1) expression levels were confirmed by immunohistochemical and western blotting analyses. Compared with control mice, diabetic mice had significantly higher blood glucose concentrations (p diabetic mice; however, immunostaining of whole-mount retinas revealed an increased number of retinal vessels. Furthermore, histopathological staining showed significant reduction in the whole retinal thickness. GFAP expression was slightly higher, whereas fewer NG2 + pericytes were observed in diabetic mice than in control mice. ACE1, AT1R, renin, HIF-1α, VEGF, VEGFR2, and HO-1 expression were up-regulated in the LC of the STZ-induced diabetic mice. Collectively, ACE 1, AT1R, HIF-1α, VEGF, VEGFR2, and HO-1 activation in the LC region in diabetic mice may be involved in diabetes via the RAS and induction of angiogenesis and oxidative stress.

Antidiabetic activities of a cucurbitane‑type triterpenoid compound from Momordica charantia in alloxan‑induced diabetic mice.

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Jiang, Bowen; Ji, Mingli; Liu, Wei; Chen, Lili; Cai, Zhiyu; Zhao, Yuqing; Bi, Xiuli

2016-11-01

Momordica charantia has been used to treat a variety of diseases, including inflammation, diabetes and cancer. A cucurbitane‑type triterpenoid [(19R,23E)‑5β, 19‑epoxy‑19‑methoxy‑cucurbita‑6,23,25‑trien‑3 β‑o‑l] previously isolated from M. charantia was demonstrated to possess significant cytotoxicity against cancer cells. The current study investigated the effects of this compound (referred to as compound K16) on diabetes using an alloxan‑induced diabetic mouse model. C57BL/6J mice were intraperitoneally injected with alloxan (10 mg/kg body weight), and those with blood glucose concentration higher than 10 mM were selected for further experiments. Diabetic C57BL/6J mice induced by alloxan were administered 0.9% saline solution, metformine (10 mg/kg body weight), or K16 (25 or 50 mg/kg body weight) by gavage for 4 weeks, followed by analysis of blood glucose level, glucose tolerance, serum lipid levels and organ indexes. The results demonstrated that compound K16 significantly reduced blood glucose (31‑48.6%) and blood lipids (13.5‑42.8%; triglycerides and cholesterol), while improving glucose tolerance compared with diabetic mice treated with saline solution, suggesting a positive improvement in glucose and lipid metabolism following K16 treatment. Furthermore, similarly to metformine, compound K16 markedly upregulated the expression of a number of insulin signaling pathway‑associated proteins, including insulin receptor, insulin receptor substrate 1, glycogen synthase kinase 3β, Akt serine/threonine kinase, and the transcript levels of glucose transporter type 4 and AMP‑activated protein kinase α1. The results of the current study demonstrated that compound K16 alleviated diabetic metabolic symptoms in alloxan‑induced diabetic mice, potentially by affecting genes and proteins involved in insulin metabolism signaling.

Human LT-alpha-mediated resistance to autoimmune diabetes is induced in NOD, but not NOD-scid, mice and abrogated by IL-12.

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Miyaguchi, S; Satoh, J; Takahashi, K; Sakata, Y; Nakazawa, T; Miyazaki, J; Toyota, T

2001-01-01

Systemic administration of human lymphotoxin-alpha (hLT-alpha) made NOD mice resistant not only to spontaneous autoimmune type 1 diabetes mellitus but also to cyclophosphamide (CY)-induced diabetes and diabetes transfer by diabetic NOD spleen cells (triple resistance). In this study we analyzed the mechanisms of hLT-alpha-induced resistance, focusing on (1) hLT-alpha-induced resistance in the pancreatic beta cell, (2) CY-resistant suppressor cells, (3) suppression of induction or function of effector cells for beta cell destruction, or (4) others. To examine the first possibility in vitro, a NOD-derived beta cell line (MIN6N) was pretreated with hLT-alpha and then mixed with diabetic NOD spleen cells and MIN6N cell viability was measured. Treatment with hLT-alpha did not protect MIN6N cells but rather enhanced cytotoxicity. Next NOD-scid mice were pretreated with hLT-alpha and then transferred with diabetic NOD spleen. All the recipients developed diabetes. These results excluded the first possibility. The second possibility was also excluded by a cotransfer experiment, in which diabetic NOD spleen cells were cotransferred to NOD-scid mice with nontreated or hLT-alpha-treated nondiabetic NOD spleens. There was no significant difference in diabetes incidence between the two groups. To observe the third possibility, spleen cells of hLT-alpha-treated triple-resistant NOD mice were transferred to NOD-scid mice. Diabetes developed in the recipients, although the onset of diabetes was slightly delayed. Finally, hLT-alpha-treated triple-resistant NOD mice developed diabetes 1 week after daily IL-12 treatment. In summary, hLT-alpha administration made NOD mice resistant to effector cells for beta cell destruction. This resistance was induced in NOD, but not in NOD-scid, mice, indicating that lymphocytes were obligatory for the resistance. However, it was not mediated by transferable suppressor cells. Because effector cells were present in hLT-alpha-treated NOD spleen and

Ghrelin reverses experimental diabetic neuropathy in mice

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Kyoraku, Itaru; Shiomi, Kazutaka [Division of Neurology, Respirology, Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Kiyotake, Miyazaki 889-1692 (Japan); Kangawa, Kenji [Department of Biochemistry, National Cardiovascular Center Research Institute, Osaka 565-8565 (Japan); Nakazato, Masamitsu, E-mail: nakazato@med.miyazaki-u.ac.jp [Division of Neurology, Respirology, Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Kiyotake, Miyazaki 889-1692 (Japan)

2009-11-20

Ghrelin, an acylated peptide produced in the stomach, increases food intake and growth hormone secretion, suppresses inflammation and oxidative stress, and promotes cell survival and proliferation. We investigated the pharmacological potential of ghrelin in the treatment of polyneuropathy in uncontrolled streptozotocin (STZ)-induced diabetes in mice. Ghrelin or desacyl-ghrelin was administered daily for 4 weeks after STZ-induced diabetic polyneuropathy had developed. Ghrelin administration did not alter food intake, body weight gain, blood glucose levels, or plasma insulin levels when compared with mice given saline or desacyl-ghrelin administration. Ghrelin administration ameliorated reductions in motor and sensory nerve conduction velocities in diabetic mice and normalized their temperature sensation and plasma concentrations of 8-isoprostaglandin {alpha}, an oxidative stress marker. Desacyl-ghrelin failed to have any effect. Ghrelin administration in a mouse model of diabetes ameliorated polyneuropathy. Thus, ghrelin's effects represent a novel therapeutic paradigm for the treatment of this otherwise intractable disorder.

Ghrelin reverses experimental diabetic neuropathy in mice

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Kyoraku, Itaru; Shiomi, Kazutaka; Kangawa, Kenji; Nakazato, Masamitsu

2009-01-01

Ghrelin, an acylated peptide produced in the stomach, increases food intake and growth hormone secretion, suppresses inflammation and oxidative stress, and promotes cell survival and proliferation. We investigated the pharmacological potential of ghrelin in the treatment of polyneuropathy in uncontrolled streptozotocin (STZ)-induced diabetes in mice. Ghrelin or desacyl-ghrelin was administered daily for 4 weeks after STZ-induced diabetic polyneuropathy had developed. Ghrelin administration did not alter food intake, body weight gain, blood glucose levels, or plasma insulin levels when compared with mice given saline or desacyl-ghrelin administration. Ghrelin administration ameliorated reductions in motor and sensory nerve conduction velocities in diabetic mice and normalized their temperature sensation and plasma concentrations of 8-isoprostaglandin α, an oxidative stress marker. Desacyl-ghrelin failed to have any effect. Ghrelin administration in a mouse model of diabetes ameliorated polyneuropathy. Thus, ghrelin's effects represent a novel therapeutic paradigm for the treatment of this otherwise intractable disorder.

Olive leaf down-regulates the oxidative stress and immune dysregulation in streptozotocin-induced diabetic mice.

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Park, Jung-Hyun; Jung, Ji-Hye; Yang, Jin-Young; Kim, Hyun-Sook

2013-11-01

Type 1 diabetes is an endocrinologic disorder characterized by uncontrolled glucose regulation and oxidative stress. Olive leaves have been studied extensively for their antioxidant activity and capacity to improve immune function. We hypothesized that olive leaf powder supplementation will be effective in inhibiting the oxidative stress and immune dysregulation in streptozotocin (STZ)-induced diabetic mice. Mice were assigned to 1 of 5 groups: control (C), STZ-induced diabetes (D), and STZ-induced diabetes supplemented with very low dose (VLOL), low dose (LOL), or high dose of olive leaf powder (HOL). Blood glucose in the VLOL and LOL groups was lower than that in the D group (P LOL groups. Nitric oxide levels decreased in the VLOL and LOL groups, as compared with the D group. The messenger RNA expression levels of inducible nitric oxide synthase were significantly decreased in the VLOL and HOL groups, and interferon-γ levels were significantly decreased in the liver of the VLOL, LOL, and HOL groups compared with the levels in the D group. Interleukin-17 levels were significantly decreased in the VLOL and HOL groups. Th1 and Th17 cytokine levels were increased in the D group but decreased in all the experimental groups. Th2 cytokine levels were increased in all olive leaf-supplemented groups compared with those in the D group. These results indicate a reduction in the levels of proinflammatory cytokines, suggesting that olive leaves have the potential to provide therapeutic inhibition of diabetic complications. © 2013.

Influence of fluoride on streptozotocin induced diabetic nephrotoxicity in mice: Protective role of Asian ginseng (Panax ginseng & banaba (Lagerstroemia speciosa on mitochondrial oxidative stress

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Mahaboob P Basha

2013-01-01

Full Text Available Background & objectives: Chronic fluoride intoxication through drinking water is a serious health problem. Patients with diabetes are known to have impaired renal function and elimination of fluoride from the body is mainly done through kidney. Fluoride toxicity in diabetes patients may aggravate complications. In this study, the influence of fluoride was assessed on streptozotocin (STZ induced diabetes in mice as also the efficacy/protective effective of oral supplementation of ginseng (GE and banaba leaf extracts (BLE. Methods: The efficacy of plant extracts, GE and BLE at doses of 50, 150, 250 mg/kg b.w./day alone and in combination, was tested for a period of 15 days on fluoride treated STZ induced diabetic animals. Results: Fluoride exposure to mice with STZ-induced diabetes produced significant changes in OSI (organo-somatic index, fluoride content, blood glucose, urea, serum creatinine and oxidative stress indices in kidney tissues with evident histological alterations. Among the antioxidant treatments, combination therapy of GE and BLE at 150 mg/kg b.w. significantly normalized the impaired biochemical variables in kidney tissues of fluoride toxicated diabetic mice. Interpretations & conclusions: High fluoride uptake was found to be diabetogenic and further aggravated the renal oxidative damage and thereby the toxicity in mice with STZ induced diabetes mice. GE and BLE exposure individually or in combination at a dose of 150 mg/kg b.w./day for 15 days exhibited protective effects on fluoride toxicated STZ induced nephrotoxicity in mice.

Caffeine consumption prevents diabetes-induced memory impairment and synaptotoxicity in the hippocampus of NONcZNO10/LTJ mice.

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João M N Duarte

Full Text Available Diabetic conditions are associated with modified brain function, namely with cognitive deficits, through largely undetermined processes. More than understanding the underlying mechanism, it is important to devise novel strategies to alleviate diabetes-induced cognitive deficits. Caffeine (a mixed antagonist of adenosine A(1 and A(2A receptors emerges as a promising candidate since caffeine consumption reduces the risk of diabetes and effectively prevents memory deficits caused by different noxious stimuli. Thus, we took advantage of a novel animal model of type 2 diabetes to investigate the behavioural, neurochemical and morphological modifications present in the hippocampus and tested if caffeine consumption might prevent these changes. We used a model closely mimicking the human type 2 diabetes condition, NONcNZO10/LtJ mice, which become diabetic at 7-11 months when kept under an 11% fat diet. Caffeine (1 g/l was applied in the drinking water from 7 months onwards. Diabetic mice displayed a decreased spontaneous alternation in the Y-maze accompanied by a decreased density of nerve terminal markers (synaptophysin, SNAP25, mainly glutamatergic (vesicular glutamate transporters, and increased astrogliosis (GFAP immunoreactivity compared to their wild type littermates kept under the same diet. Furthermore, diabetic mice displayed up-regulated A(2A receptors and down-regulated A(1 receptors in the hippocampus. Caffeine consumption restored memory performance and abrogated the diabetes-induced loss of nerve terminals and astrogliosis. These results provide the first evidence that type 2 diabetic mice display a loss of nerve terminal markers and astrogliosis, which is associated with memory impairment; furthermore, caffeine consumption prevents synaptic dysfunction and astrogliosis as well as memory impairment in type 2 diabetes.

Caffeine consumption prevents diabetes-induced memory impairment and synaptotoxicity in the hippocampus of NONcZNO10/LTJ mice.

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Duarte, João M N; Agostinho, Paula M; Carvalho, Rui A; Cunha, Rodrigo A

2012-01-01

Diabetic conditions are associated with modified brain function, namely with cognitive deficits, through largely undetermined processes. More than understanding the underlying mechanism, it is important to devise novel strategies to alleviate diabetes-induced cognitive deficits. Caffeine (a mixed antagonist of adenosine A(1) and A(2A) receptors) emerges as a promising candidate since caffeine consumption reduces the risk of diabetes and effectively prevents memory deficits caused by different noxious stimuli. Thus, we took advantage of a novel animal model of type 2 diabetes to investigate the behavioural, neurochemical and morphological modifications present in the hippocampus and tested if caffeine consumption might prevent these changes. We used a model closely mimicking the human type 2 diabetes condition, NONcNZO10/LtJ mice, which become diabetic at 7-11 months when kept under an 11% fat diet. Caffeine (1 g/l) was applied in the drinking water from 7 months onwards. Diabetic mice displayed a decreased spontaneous alternation in the Y-maze accompanied by a decreased density of nerve terminal markers (synaptophysin, SNAP25), mainly glutamatergic (vesicular glutamate transporters), and increased astrogliosis (GFAP immunoreactivity) compared to their wild type littermates kept under the same diet. Furthermore, diabetic mice displayed up-regulated A(2A) receptors and down-regulated A(1) receptors in the hippocampus. Caffeine consumption restored memory performance and abrogated the diabetes-induced loss of nerve terminals and astrogliosis. These results provide the first evidence that type 2 diabetic mice display a loss of nerve terminal markers and astrogliosis, which is associated with memory impairment; furthermore, caffeine consumption prevents synaptic dysfunction and astrogliosis as well as memory impairment in type 2 diabetes.

Methanolic Root Extract of Rauwolfia serpentina Benth Improves the Glycemic, Antiatherogenic, and Cardioprotective Indices in Alloxan-Induced Diabetic Mice

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Muhammad Bilal Azmi

2012-01-01

Full Text Available The aim of the study was to evaluate the phytochemistry and the effect of methanolic root extract (MREt of Rauwolfia serpentina on alloxan-induced diabetic Wister male mice. Mice were divided in control (distilled water at 1 mL/kg and alloxan-induced diabetic mice which subdivided into diabetic (distilled water at 1 mL/kg, negative (0.05% dimethyl sulfoxide at 1 mL/kg, positive (glibenclamide at 5 mg/kg controls, and three test groups (MREt at 10, 30, and 60 mg/kg. All treatments were given orally for 14 days. Qualitatively MREt showed the presence of alkaloids, carbohydrates, flavonoids, glycosides, cardiac glycosides, phlobatannins, resins, saponins, steroids, tannins, and triterpenoids, while quantitatively extract was rich in total phenols. The flavonoids, saponins and alkaloids were also determined in root powder. MREt found effective in improving the body weights, glucose and insulin levels, insulin/glucose ratio, glycosylated and total hemoglobin in test groups as compared to diabetic control. Similarly, significantly decreased levels of total cholesterol, triglycerides, low-density lipoprotein (LDL-c, and very low-density lipoprotein (VLDL-c cholesterols were found in test groups. Significant lipolysis with improved glycogenesis was also found in liver tissues of all test groups. ALT levels were found normal in all groups. Thus, MREt improves the glycemic, antiatherogenic, coronary risk, and cardioprotective indices in alloxan-induced diabetic mice.

Methanolic Root Extract of Rauwolfia serpentina Benth Improves the Glycemic, Antiatherogenic, and Cardioprotective Indices in Alloxan-Induced Diabetic Mice.

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Azmi, Muhammad Bilal; Qureshi, Shamim A

2012-01-01

The aim of the study was to evaluate the phytochemistry and the effect of methanolic root extract (MREt) of Rauwolfia serpentina on alloxan-induced diabetic Wister male mice. Mice were divided in control (distilled water at 1 mL/kg) and alloxan-induced diabetic mice which subdivided into diabetic (distilled water at 1 mL/kg), negative (0.05% dimethyl sulfoxide at 1 mL/kg), positive (glibenclamide at 5 mg/kg) controls, and three test groups (MREt at 10, 30, and 60 mg/kg). All treatments were given orally for 14 days. Qualitatively MREt showed the presence of alkaloids, carbohydrates, flavonoids, glycosides, cardiac glycosides, phlobatannins, resins, saponins, steroids, tannins, and triterpenoids, while quantitatively extract was rich in total phenols. The flavonoids, saponins and alkaloids were also determined in root powder. MREt found effective in improving the body weights, glucose and insulin levels, insulin/glucose ratio, glycosylated and total hemoglobin in test groups as compared to diabetic control. Similarly, significantly decreased levels of total cholesterol, triglycerides, low-density lipoprotein (LDL-c), and very low-density lipoprotein (VLDL-c) cholesterols were found in test groups. Significant lipolysis with improved glycogenesis was also found in liver tissues of all test groups. ALT levels were found normal in all groups. Thus, MREt improves the glycemic, antiatherogenic, coronary risk, and cardioprotective indices in alloxan-induced diabetic mice.

Antioxidant Role of Vitamin D in mice with Alloxan-Induced Diabetes.

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Iqbal, Sarah; Khan, Saman; Naseem, Imrana

2017-12-04

The discovery of vitamin D receptors has revolutionized the understanding of vitamin D biology, which is now thought to influence a wide array of cell pathways. The antihyperglycemic actions of vitamin D involving calcium metabolism have been widely discussed, but studies are now suggesting a possibility of vitamin D-induced amelioration of oxidative stress. Despite its significance in disease pathogenesis, oxidative status remains poorly investigated with respect to vitamin D treatment in the biology of diabetes mellitus. The present study was aimed at assessing the antioxidant therapeutic potential of vitamin D in diabetes mellitus. Balb/c mice were induced to experimental diabetes with a single dose of alloxan. Following a 15-day treatment period, various parameters pertaining to glucose metabolism, oxidative stress, zinc concentration and DNA damage were analyzed. With the exception of superoxide dismutase and catalase, the antioxidant enzyme activities were slightly altered in various groups. However, improved glucose homeostasis and zinc concentration and reduced DNA damage were observed in the group treated with vitamin D. The present work accounts for the ubiquitous roles of vitamin D in various diseases and highlights its role as a therapeutic intervention in diabetes mellitus. Copyright © 2017 Diabetes Canada. Published by Elsevier Inc. All rights reserved.

Effects of angiotensin II type 1 receptor blocker on bones in mice with type 1 diabetes induced by streptozotocin.

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Zhang, Yan; Diao, Teng-Yue; Gu, Sa-Sa; Wu, Shu-Yan; Gebru, Yoseph A; Chen, Xi; Wang, Jing-Yu; Ran, Shu; Wong, Man-Sau

2014-09-01

This study was performed to address the pathological roles of the skeletal renin-angiotensin system (RAS) in type 1 diabetes-induced osteoporosis and the effects of the angiotensin II type 1 receptor blocker losartan on bones in diabetic mice. Bone histomorphology was detected by H&E staining, Safranin O staining and X-ray radiography. Micro-CT was performed for the analysis of bone parameters. Gene and protein expression were determined by RT-PCR and immunoblotting. Type 1 diabetic mice displayed osteopenia phenotype, and losartan treatment had no osteoprotective effects on diabetic mice as shown by the reduction of bone mineral density and microarchitectural parameters at the proximal metaphysis of the tibia. The mRNA expression of AGT, renin receptor and ACE, and protein expression of renin and AT1R were markedly up-regulated in the bones of vehicle-treated diabetic mice compared to those of non-diabetic mice. The treatment with losartan further significantly increased the expression of AGT, renin, angiotensin II and AT1R, and reduced the expression of AT2R receptor as compared to those of diabetic mice. Local bone RAS functionally played a role in the development of type 1 diabetic osteoporosis, and losartan had no bone-sparing function in diabetes mice because of enhance skeletal RAS activity. © The Author(s) 2013.

Quercetin Isolated from Toona sinensis Leaves Attenuates Hyperglycemia and Protects Hepatocytes in High-Carbohydrate/High-Fat Diet and Alloxan Induced Experimental Diabetic Mice

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Yali Zhang

2016-01-01

Full Text Available The development of diabetes mellitus is related to oxidant stress induced by a high carbohydrate/high-fat diet (HFD. Quercetin, as a major bioactive component in Toona sinensis leaves (QTL, is a natural antioxidant. However, the exact mechanism by which QTL ameliorate diabetes mellitus is still unknown. In this study, we investigated the hypoglycemic effects and hepatocytes protection of QTL on HFD and alloxan induced diabetic mice. Intragastric administration of QTL significantly reduced body weight gain, serum glucose, insulin, total cholesterol, triglyceride, low density lipoprotein-cholesterol, alanine aminotransferase, and aspartate aminotransferase serum levels compared to those of diabetic mice. Furthermore, it significantly attenuated oxidative stress, as determined by lipid peroxidation, nitric oxide content, and inducible nitric oxide synthase activity and as a result attenuated liver injury. QTL also significantly suppressed the diabetes-induced activation of the p65/NF-κB and ERK1/2/MAPK pathways, as well as caspase-9 and caspase-3 levels in liver tissues of diabetic mice. Finally, micrograph analysis of liver samples showed decreased cellular organelle injury in hepatocytes of QTL treated mice. Taken together, QTL can be viewed as a promising dietary agent that can be used to reduce the risk of diabetes mellitus and its secondary complications by ameliorating oxidative stress in the liver.

Urotensin II Induces ER Stress and EMT and Increase Extracellular Matrix Production in Renal Tubular Epithelial Cell in Early Diabetic Mice

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Xin-Xin Pang

2016-07-01

Full Text Available Background/Aims: Urotensin II (UII and its receptor are highly expressed in the kidney tissue of patients with diabetic nephropathy (DN. The aim of this study is to examine the roles of UII in the induction of endoplasmic reticulum stress (ER stress and Epithelial-mesenchymal transition (EMT in DN in vivo and in vitro. Methods: Kidney tissues were collected from patients with DN. C57BL/6 mice and mice with UII receptor knock out were injected with two consecutive doses of streptozotocin to induce diabetes and were sacrificed at 3th week for in vivo study. HK-2 cells in vitro were cultured and treated with UII. Markers of ER stress and EMT, fibronectin and type IV collagen were detected by immunohistochemistry, real time PCR and western blot. Results: We found that the expressions of protein of UII, GRP78, CHOP, ALPHA-SMA, fibronectin and type IV collagen were upregulated while E-cadherin protein was downregulated as shown by immunohistochemistry or western blot analysis in kidney of diabetic mice in comparison to normal control; moreover expressions of GRP78, CHOP, ALPHA-SMA, fibronectin and type IV collagen were inhibited while E-caherin expression was enhanced in kidney in diabetic mice with UII receptor knock out in comparison to C57BL/6 diabetic mice. In HK-2 cells, UII induced upregulation of GRP78, CHOP, ALPHA-SMA, fibroblast-specifc protein 1(FSP-1, fibronectin and type collagen and downregulation of E-cadherin. UII receptor antagonist can block UII-induced ER stress and EMT; moreover, 4-PBA can inhibit the mRNA expression of ALPHA-SMA and FSP1 induced by UII in HK-2 cells. Conclusions: We are the first to verify UII induces ER stress and EMT and increase extracellular matrix production in renal tubular epithelial cell in early diabetic mice. Moreover, UII may induce renal tubular epithelial EMT via triggering ER stress pathway in vitro, which might be the new pathogenic pathway for the development of renal fibrosis in DN.

Ameliorative effect of dietary genistein on diabetes induced hyper-inflammation and oxidative stress during early stage of wound healing in alloxan induced diabetic mice.

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Eo, Hyeyoon; Lee, Hea-Ji; Lim, Yunsook

2016-09-23

Among the diabetic complications, diabetic foot ulcer due to delayed wound healing is one of the most significant clinical problems. Early inflammatory stage is important for better prognosis during wound healing. Thus, regulation of inflammatory response during early stage of wound healing is main target for complete cutaneous recovery. This study investigated the role of genistein supplementation in inflammation and oxidative stress, which are related to NLRP3 inflammasome, NFκB and Nrf2 activation, during cutaneous wound healing in alloxan-induced diabetic mice. Mice with diabetes with fasting blood glucose (FBG) levels > 250 mg/dl were fed diets with AIN-93G rodent diet containing 0%, 0.025% (LG) or 0.1% (HG) genistein. After 2 weeks of genistein supplementation, excisional wounds were made by biopsy punches (4 mm). Genistein supplementation improved fasting glucose levels and wound closure rate. Moreover, genistein supplementation restored NLRP3 inflammasome (NLRP3, ASC and caspase-1) at the basal level and ameliorated both inflammation (TNFα, iNOS, COX2 and NFκB) and antioxidant defense system (Nrf2, HO-1, GPx, and catalase) during early stage of wound healing in diabetic mice. Taken together, genistein supplementation would be a potential therapeutic nutrient in prevention and treatment of delayed wound healing by modulation of inflammation and oxidative stress during inflammatory stage. Copyright © 2016. Published by Elsevier Inc.

Hypolipidemic and hypoglycemic activities of a oleanolic acid derivative from Malva parviflora on streptozotocin-induced diabetic mice.

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Gutiérrez, Rosa Martha Pérez

2017-05-01

One new oleanolic acid derivative, 2α,3β,23α,29α tetrahydroxyolean-12(13)-en-28-oic acid (1) was isolated from the aerial parts of Malva parviflora. Their structure was characterized by spectroscopic methods. The hypolipidemic and hypoglycemic activities of 1 was analyzed in in streptozotocin (STZ)-nicotinamide-induced type 2 diabetes in mice (MD) and type 1 diabetes in streptozotocin-induced diabetic mice (SD). Triterpene was administered orally at doses of 20 mg/kg for 4 weeks. Organ weight, body weight, glucose, fasting insulin, cholesterol-related lipid profile parameters, glutamate oxaloacetate transaminase (SGOT), glutamate pyruvate transaminase (SGPT), serum alkaline phosphatase (SALP), glucokinase, hexokinase, glucose-6-phosphatase activities and glycogen in liver were measured after 4 weeks of treatment. The results indicated that 1 regulate glucose metabolism, lipid profile, lipid peroxidation, increased body weight, glucokinase and hexokinase activities inhibited triglycerides, total cholesterol, low density lipoproteins level, SGOT, SGPT, SALP, glycogen in liver and glucose-6-phosphatase. In addition, improvement of insulin resistance and protective effect for pancreatic β-cells, also 1 may changes the expression of pro-inflammatory cytokine (IL-6 and TNF-α levels) and enzymes (PAL2, COX-2, and LOX). The results suggest that 1 has hypolipidemic and hypoglycemic, anti-inflammatory, activities, improve insulin resistance and hepatic enzymes in streptozotocin-induced diabetic mice.

Targeted delivery of antigen to intestinal dendritic cells induces oral tolerance and prevents autoimmune diabetes in NOD mice.

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Chen, Yulin; Wu, Jie; Wang, Jiajia; Zhang, Wenjing; Xu, Bohui; Xu, Xiaojun; Zong, Li

2018-03-15

The intestinal immune system is an ideal target to induce immune tolerance physiologically. However, the efficiency of oral protein antigen delivery is limited by degradation of the antigen in the gastrointestinal tract and poor uptake by antigen-presenting cells. Gut dendritic cells (DCs) are professional antigen-presenting cells that are prone to inducing antigen-specific immune tolerance. In this study, we delivered the antigen heat shock protein 65-6×P277 (H6P) directly to the gut DCs of NOD mice through oral vaccination with H6P-loaded targeting nanoparticles (NPs), and investigated the ability of this antigen to induce immune tolerance to prevent autoimmune diabetes in NOD mice. A targeting NP delivery system was developed to encapsulate H6P, and the ability of this system to protect and facilitate H6P delivery to gut DCs was assessed. NOD mice were immunised with H6P-loaded targeting NPs orally once a week for 7 weeks and the onset of diabetes was assessed by monitoring blood glucose levels. H6P-loaded targeting NPs protected the encapsulated H6P from degradation in the gastrointestinal tract environment and significantly increased the uptake of H6P by DCs in the gut Peyer's patches (4.1 times higher uptake compared with the control H6P solution group). Oral vaccination with H6P-loaded targeting NPs induced antigen-specific T cell tolerance and prevented diabetes in 100% of NOD mice. Immune deviation (T helper [Th]1 to Th2) and CD4 + CD25 + FOXP3 + regulatory T cells were found to participate in the induction of immune tolerance. In this study, we successfully induced antigen-specific T cell tolerance and prevented the onset of diabetes in NOD mice. To our knowledge, this is the first attempt at delivering antigen to gut DCs using targeting NPs to induce T cell tolerance.

Renal Protective Effect of Xiao-Chai-Hu-Tang on Diabetic Nephropathy of Type 1-Diabetic Mice

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Chun-Ching Lin

2012-01-01

Full Text Available Xiao-Chai-Hu-Tang (XCHT, a traditional Chinese medicine formula consisting of seven medicinal plants, is used in the treatment of various diseases. We show here that XCHT could protect type-1 diabetic mice against diabetic nephropathy, using streptozotocin (STZ-induced diabetic mice and high-glucose (HG-exposed rat mesangial cell (RMC as models. Following 4 weeks of oral administration with XCHT, renal functions and renal hypertrophy significantly improved in the STZ-diabetic mice, while serum glucose was only moderately reduced compared to vehicle treatment. Treatment with XCHT in the STZ-diabetic mice and HG-exposed RMC resulted in a decrease in expression levels of TGF-β1, fibronectin, and collagen IV, with concomitant increase in BMP-7 expression. Data from DPPH assay, DHE stain, and CM-H2DCFDA analysis indicated that XCHT could scavenge free radicals and inhibit high-glucose-induced ROS in RMCs. Taken together, these results suggest that treatment with XCHT can improve renal functions in STZ-diabetic mice, an effect that is potentially mediated through decreasing oxidative stress and production of TGF-β1, fibronectin, and collagen IV in the kidney during development of diabetic nephropathy. XCHT, therefore merits further investigation for application to improve renal functions in diabetic disorders.

Early myocardial dysfunction in streptozotocin-induced diabetic mice: a study using in vivo magnetic resonance imaging (MRI

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Chandrasekaran Suresh

2007-02-01

Full Text Available Abstract Background Diabetes is associated with a cardiomyopathy that is independent of coronary artery disease or hypertension. In the present study we used in vivo magnetic resonance imaging (MRI and echocardiographic techniques to examine and characterize early changes in myocardial function in a mouse model of type 1 diabetes. Methods Diabetes was induced in 8-week old C57BL/6 mice with two intraperitoneal injections of streptozotocin. The blood glucose levels were maintained at 19–25 mmol/l using intermittent low dosages of long acting insulin glargine. MRI and echocardiography were performed at 4 weeks of diabetes (age of 12 weeks in diabetic mice and age-matched controls. Results After 4 weeks of hyperglycemia one marker of mitochondrial function, NADH oxidase activity, was decreased to 50% of control animals. MRI studies of diabetic mice at 4 weeks demonstrated significant deficits in myocardial morphology and functionality including: a decreased left ventricular (LV wall thickness, an increased LV end-systolic diameter and volume, a diminished LV ejection fraction and cardiac output, a decreased LV circumferential shortening, and decreased LV peak ejection and filling rates. M-mode echocardiographic and Doppler flow studies of diabetic mice at 4 weeks showed a decreased wall thickening and increased E/A ratio, supporting both systolic and diastolic dysfunction. Conclusion Our study demonstrates that MRI interrogation can identify the onset of diabetic cardiomyopathy in mice with its impaired functional capacity and altered morphology. The MRI technique will lend itself to repetitive study of early changes in cardiac function in small animal models of diabetic cardiomyopathy.

Early myocardial dysfunction in streptozotocin-induced diabetic mice: a study using in vivo magnetic resonance imaging (MRI)

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Yu, Xichun; Tesiram, Yasvir A; Towner, Rheal A; Abbott, Andrew; Patterson, Eugene; Huang, Shijun; Garrett, Marion W; Chandrasekaran, Suresh; Matsuzaki, Satoshi; Szweda, Luke I; Gordon, Brian E; Kem, David C

2007-01-01

Background Diabetes is associated with a cardiomyopathy that is independent of coronary artery disease or hypertension. In the present study we used in vivo magnetic resonance imaging (MRI) and echocardiographic techniques to examine and characterize early changes in myocardial function in a mouse model of type 1 diabetes. Methods Diabetes was induced in 8-week old C57BL/6 mice with two intraperitoneal injections of streptozotocin. The blood glucose levels were maintained at 19–25 mmol/l using intermittent low dosages of long acting insulin glargine. MRI and echocardiography were performed at 4 weeks of diabetes (age of 12 weeks) in diabetic mice and age-matched controls. Results After 4 weeks of hyperglycemia one marker of mitochondrial function, NADH oxidase activity, was decreased to 50% of control animals. MRI studies of diabetic mice at 4 weeks demonstrated significant deficits in myocardial morphology and functionality including: a decreased left ventricular (LV) wall thickness, an increased LV end-systolic diameter and volume, a diminished LV ejection fraction and cardiac output, a decreased LV circumferential shortening, and decreased LV peak ejection and filling rates. M-mode echocardiographic and Doppler flow studies of diabetic mice at 4 weeks showed a decreased wall thickening and increased E/A ratio, supporting both systolic and diastolic dysfunction. Conclusion Our study demonstrates that MRI interrogation can identify the onset of diabetic cardiomyopathy in mice with its impaired functional capacity and altered morphology. The MRI technique will lend itself to repetitive study of early changes in cardiac function in small animal models of diabetic cardiomyopathy. PMID:17309798

Accumulation of pathogenic ΔmtDNA induced deafness but not diabetic phenotypes in mito-mice

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Nakada, Kazuto; Sato, Akitsugu; Sone, Hideyuki; Kasahara, Atsuko; Ikeda, Katsuhisa; Kagawa, Yasuo; Yonekawa, Hiromichi; Hayashi, Jun-Ichi

2004-01-01

Mito-mice carrying various proportions of deletion mutant mtDNA (ΔmtDNA) were generated by introduction of the ΔmtDNA from cultured cells into fertilized eggs of C57BL/6J (B6) strain mice. Great advantages of mito-mice are that they share exactly the same nuclear-genome background, and that their genetic variations are restricted to proportions of pathogenic ΔmtDNA. Since accumulation of ΔmtDNA to more than 75% induced respiration defects, the disease phenotypes observed exclusively in mito-mice carrying more than 75% ΔmtDNA should be due to accumulated ΔmtDNA. In this study, we focused on the expressions of hearing loss and diabetic phenotypes, since these common age-associated abnormalities have sometimes been reported to be inherited maternally and to be associated with pathogenic mutant mtDNAs. The results showed that accumulation of exogenously introduced ΔmtDNA was responsible for hearing loss, but not for expression of diabetic phenotypes in mito-mice

Effects of metformin on inflammation and short-term memory in streptozotocin-induced diabetic mice.

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Oliveira, Wilma Helena; Nunes, Ana Karolina; França, Maria Eduarda Rocha; Santos, Laise Aline; Lós, Deniele Bezerra; Rocha, Sura Wanessa; Barbosa, Karla Patrícia; Rodrigues, Gabriel Barros; Peixoto, Christina Alves

2016-08-01

The aim of the present study was to analyze the action of metformin on short-term memory, glial cell activation and neuroinflammation caused by experimental diabetic encephalopathy in C57BL/6 mice. Diabetes was induced by the intraperitoneal injection of a dose of 90mg/kg of streptozotocin on two successive days. Mice with blood glucose levels ≥200dl/ml were considered diabetic and were given metformin hydrochloride at doses of 100mg/kg and 200mg/kg (by gavage, twice daily) for 21 days. On the final day of treatment, the mice underwent a T-maze test. On the 22nd day of treatment all the animals were anesthetized and euthanized. Diabetic animals treated with metformin had a higher spatial memory score. The hippocampus of the diabetic animals presented reactive gliosis, neuronal loss, NF-kB signaling activation, and high levels of IL-1 and VEGF. In addition, the T-maze test scores of these animals were low. Treatment with metformin reduced the expression of GFAP, Iba-1 (astrocyte and microglial markers) and the inflammation markers (p-IKB, IL-1 and VEGF), while enhancing p-AMPK and eNOS levels and increasing neuronal survival (Fox-1 and NeuN). Treatment with metformin also improved the spatial memory scores of diabetic animals. In conclusion, the present study showed that metformin can significantly reduce neuroinflammation and can decrease the loss of neurons in the hippocampus of diabetic animals, which can subsequently promote improvements in spatial memory. Copyright © 2016 Elsevier B.V. All rights reserved.

Protective effects of total extracts of Averrhoa carambola L. (Oxalidaceae) roots on streptozotocin-induced diabetic mice.

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Xu, Xiaohui; Liang, Tao; Wen, Qingwei; Lin, Xing; Tang, Jingzhi; Zuo, Qiaoyun; Tao, Liqun; Xuan, Feifei; Huang, Renbin

2014-01-01

In Chinese culture, the roots of Averrhoa carambola L. have long been used for medical purposes due to their potent pharmaceutical activities, such as improving digestive function and treating diabetes. Recently, we prepared extracts of Averrhoa carambola L. root (EACR), which were isolated from Averrhoa carambola L. roots using ethanol or water. This study was designed to investigate the potential effects of EACR on streptozotocin (STZ) diabetic mice and to explore the underlying mechanism of these effects. Male mice were injected with STZ through the tail vein (120 mg/kg body weight) and were identified as a diabetic mouse model when the level of blood glucose was ≥11.1 mmol/L. Subsequently, the mice were administered EACR (150, 300, 600, 1200 mg/kg body weight/d) and metformin (320 mg/kg body weight/d) via intragastric gavage for three weeks. The results indicated that EACR significantly decreased the serum levels of blood glucose, total cholesterol (TC), triglycerides (TGs) and free fatty acids (FFAs), whereas the content of serum insulin was elevated. In addition, the expressions of apoptosis-related regulators (including caspase-3, caspase-8 and caspase-9) and the apoptosis-induced protein Bax were markedly down-regulated by EACR, whereas the expression of the anti-apoptotic Bcl-2 protein was notably increased. Furthermore, EACR could protect the diabetic mice against the STZ-induced apoptosis of pancreatic β cells. Taken together, these findings indicate that EACR plays an effective hyperglycemic role that is associated with ameliorating metabolic functions and with inhibiting apoptosis in pancreas tissue. © 2014 S. Karger AG, Basel.

Protective Effects of Total Extracts of Averrhoa carambola L. (Oxalidaceae Roots on Streptozotocin-Induced Diabetic Mice

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Xiaohui Xu

2014-04-01

Full Text Available Background: In Chinese culture, the roots of Averrhoa carambola L. have long been used for medical purposes due to their potent pharmaceutical activities, such as improving digestive function and treating diabetes. Methods: Recently, we prepared extracts of Averrhoa carambola L. root (EACR, which were isolated from Averrhoa carambola L. roots using ethanol or water. This study was designed to investigate the potential effects of EACR on streptozotocin (STZ diabetic mice and to explore the underlying mechanism of these effects. Male mice were injected with STZ through the tail vein (120 mg/kg body weight and were identified as a diabetic mouse model when the level of blood glucose was ≥11.1 mmol/L. Subsequently, the mice were administered EACR (150, 300, 600, 1200 mg/kg body weight/d and metformin (320 mg/kg body weight/d via intragastric gavage for three weeks. Results: The results indicated that EACR significantly decreased the serum levels of blood glucose, total cholesterol (TC, triglycerides (TGs and free fatty acids (FFAs, whereas the content of serum insulin was elevated. In addition, the expressions of apoptosis-related regulators (including caspase-3, caspase-8 and caspase-9 and the apoptosis-induced protein Bax were markedly down-regulated by EACR, whereas the expression of the anti-apoptotic Bcl-2 protein was notably increased. Furthermore, EACR could protect the diabetic mice against the STZ-induced apoptosis of pancreatic β cells. Conclusion: Taken together, these findings indicate that EACR plays an effective hyperglycemic role that is associated with ameliorating metabolic functions and with inhibiting apoptosis in pancreas tissue.

Antidiabetic activity and phytochemical screening of extracts of the leaves of Ajuga remota Benth on alloxan-induced diabetic mice.

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Tafesse, Tadesse Bekele; Hymete, Ariaya; Mekonnen, Yalemtsehay; Tadesse, Mekuria

2017-05-02

Ajuga remota Benth is traditionally used in Ethiopia for the management of diabetes mellitus. Since this claim has not been investigated scientifically, the aim of this study was to evaluate the antidiabetic effect and phytochemical screening of the aqueous and 70% ethanol extracts on alloxan-induced diabetic mice. After acute toxicity test, the Swiss albino mice were induced with alloxan to get experimental diabetes animals. The fasting mean blood glucose level before and after treatment for two weeks in normal, diabetic untreated and diabetic mice treated with aqueous and 70% ethanol extracts were performed. Data were statistically evaluated by using Statistical Package for the Social Sciences software version 20. P-value Phytochemical screening of both extracts indicated the presence of phenolic compounds, flavonoids, saponins, tannins, and steroids, which might contribute to the antidiabetic activity. The extracts, however, did not contain alkaloids and anthraquinones. The aqueous extract (500 mg/kg) showed the highest percentage reduction in blood glucose levels and the ability of A. remota extracts in reducing blood glucose levels presumably due to the presence of antioxidant constituents such as flavonoids. The effect of the extract supported the traditional claim of the plant.

Coronary arterial BK channel dysfunction exacerbates ischemia/reperfusion-induced myocardial injury in diabetic mice.

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Lu, Tong; Jiang, Bin; Wang, Xiao-Li; Lee, Hon-Chi

2016-09-01

The large conductance Ca(2+)-activated K(+) (BK) channels, abundantly expressed in coronary artery smooth muscle cells (SMCs), play a pivotal role in regulating coronary circulation. A large body of evidence indicates that coronary arterial BK channel function is diminished in both type 1 and type 2 diabetes. However, the consequence of coronary BK channel dysfunction in diabetes is not clear. We hypothesized that impaired coronary BK channel function exacerbates myocardial ischemia/reperfusion (I/R) injury in streptozotocin-induced diabetic mice. Combining patch-clamp techniques and cellular biological approaches, we found that diabetes facilitated the colocalization of angiotensin II (Ang II) type 1 receptors and BK channel α-subunits (BK-α), but not BK channel β1-subunits (BK-β1), in the caveolae of coronary SMCs. This caveolar compartmentation in vascular SMCs not only enhanced Ang II-mediated inhibition of BK-α but also produced a physical disassociation between BK-α and BK-β1, leading to increased infarct size in diabetic hearts. Most importantly, genetic ablation of caveolae integrity or pharmacological activation of coronary BK channels protected the cardiac function of diabetic mice from experimental I/R injury in both in vivo and ex vivo preparations. Our results demonstrate a vascular ionic mechanism underlying the poor outcome of myocardial injury in diabetes. Hence, activation of coronary BK channels may serve as a therapeutic target for cardiovascular complications of diabetes.

Fibronectin potentiates topical erythropoietin-induced wound repair in diabetic mice.

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Hamed, Saher; Ullmann, Yehuda; Egozi, Dana; Daod, Essam; Hellou, Elias; Ashkar, Manal; Gilhar, Amos; Teot, Luc

2011-06-01

Diabetes mellitus disrupts all phases of the wound repair cascade and leads to development of chronic wounds. We previously showed that topical erythropoietin (EPO) can promote wound repair in diabetic rats. Fibronectin (FN) has a critical role throughout the process of wound healing, yet it is deficient in wound tissues of diabetic patients. Therefore, we investigated the effect of topical treatment of both EPO and FN (EPO/FN) on wound repair in diabetic mice. Full-thickness excisional skin wounds in diabetic and nondiabetic mice were treated with a cream containing vehicle, EPO, FN, or EPO/FN. We assessed the rate of wound closure, angiogenesis, apoptosis, and expression of inflammatory cytokines, endothelial nitric oxide synthase (eNOS) and β1-integrin, in the wound tissues. We also investigated the effect of EPO, FN, and EPO/FN on human dermal microvascular endothelial cells and fibroblasts cultured on fibrin-coated plates, or in high glucose concentrations. EPO/FN treatment significantly increased the rate of wound closure and this effect was associated with increased angiogenesis, increased eNOS and β1-integrin expression, and reduced expression of inflammatory cytokines and apoptosis. Our findings show that EPO and FN have an additive effect on wound repair in diabetic mice.

Genetic disassociation of autoimmunity and resistance to costimulation blockade-induced transplantation tolerance in nonobese diabetic mice.

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Pearson, Todd; Markees, Thomas G; Serreze, David V; Pierce, Melissa A; Marron, Michele P; Wicker, Linda S; Peterson, Laurence B; Shultz, Leonard D; Mordes, John P; Rossini, Aldo A; Greiner, Dale L

2003-07-01

Curing type 1 diabetes by islet transplantation requires overcoming both allorejection and recurrent autoimmunity. This has been achieved with systemic immunosuppression, but tolerance induction would be preferable. Most islet allotransplant tolerance induction protocols have been tested in nonobese diabetic (NOD) mice, and most have failed. Failure has been attributed to the underlying autoimmunity, assuming that autoimmunity and resistance to transplantation tolerance have a common basis. Out of concern that NOD biology could be misleading in this regard, we tested the hypothesis that autoimmunity and resistance to transplantation tolerance in NOD mice are distinct phenotypes. Unexpectedly, we observed that (NOD x C57BL/6)F(1) mice, which have no diabetes, nonetheless resist prolongation of skin allografts by costimulation blockade. Further analyses revealed that the F(1) mice shared the dendritic cell maturation defects and abnormal CD4(+) T cell responses of the NOD but had lost its defects in macrophage maturation and NK cell activity. We conclude that resistance to allograft tolerance induction in the NOD mouse is not a direct consequence of overt autoimmunity and that autoimmunity and resistance to costimulation blockade-induced transplantation tolerance phenotypes in NOD mice can be dissociated genetically. The outcomes of tolerance induction protocols tested in NOD mice may not accurately predict outcomes in human subjects.

Effect of Curcumin on Blood Glucose Level and Some Neurobehavioral Responses in Alloxan-induced Diabetic Swiss Albino Mice

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U. A. Garkuwa; A. W. Alhassan; Y. Tanko

2017-01-01

The aim of this study was to evaluate the effect of curcumin on blood glucose level and neurobehavioral response in Alloxan-induced diabetic Swiss Albino mice. The animals were divided into five (5) groups of four each (n=4). Group I served as control and received distilled water, group II, III, IV and V were diabetic and received olive oil 1 ml/kg, glibenclamide 1 mg/kg, curcumin 50 mg/kg and curcumin 100 mg/kg respectively. Diabetes was induced using Alloxan (150 mg/kg). All administrations...

Decreased thyroidal response to thyrotropin in diabetic mice

International Nuclear Information System (INIS)

Bagchi, N.; Brown, T.R.; Shivers, B.; Lucas, S.; Mack, R.E.

1981-01-01

The effect of diabetes mellitus on the synthesis and secretion of thyroid hormone ws investigated in mice with streptozotocin-induced diabetes. Thyroid glands were labeled in vivo with 131I for 2 h. In control animals, TSH stimulated the synthesis of PB127I and 131I-labeled iodothyronines and simultaneously decreased the proportion of 131I-. These effects of TSH were not observed in diabetic animals but were demonstrable in diabetic animals treated with insulin. For studies of hormone secretion, labeled thyroid glands were cultured in vitro in medium containing 1 mM mononitrotyrosine. The rate of the hydrolysis of labeled thyroglobulin was measured as the proportion of 131I-labeled iodotyrosines and 131I-labeled iodothyronines recovered at the end of culture and was used as an index of thyroid secretion. TSH in vivo stimulated the rate of thyroglobulin hydrolysis for 6 h, with a peak occurring after 2 h. The diabetic mice had a diminished response to TSH, which improved on treatment with insulin. The addition of TSH and insulin to the culture medium significantly increased the rate of thyroglobulin hydrolysis in glands of diabetic mice over that resulting from the addition of dibutyryl cAMP alone. The generation of thyroidal cAMP in response to TSH was higher in diabetic mice than in controls. The rise in plasma T4 and T3 2 h after the administration of TSH was less in diabetic mice than in control mice or diabetic mice treated with insulin. Our studies, therefore, indicate that the thyroidal response to TSH is decreased in diabetes mellitus. The defect appears to be at a step beyond the generation of cAMP

Ludwigia octovalvis extract improves glycemic control and memory performance in diabetic mice.

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Lin, Wei-Sheng; Lo, Jung-Hsin; Yang, Jo-Hsuan; Wang, Hao-Wei; Fan, Shou-Zen; Yen, Jui-Hung; Wang, Pei-Yu

2017-07-31

Ludwigia octovalvis (Jacq.) P.H. Raven (Onagraceae) extracts have historically been consumed as a healthful drink for treating various conditions, including edema, nephritis, hypotension and diabetes. We have previously shown that Ludwigia octovalvis extract (LOE) can significantly extend lifespan and improve age-related memory deficits in Drosophila melanogaster through activating AMP-activated protein kinase (AMPK). Since AMPK has become a critical target for treating diabetes, we herein investigate the anti-hyperglycemic potential of LOE. Differentiated C2C12 muscle cells, HepG2 hepatocellular cells, streptozotocin (STZ)-induced diabetic mice and high fat diet (HFD)-induced diabetic mice were used to investigate the anti-hyperglycemic potential of LOE. The open field test and novel object recognition test were used to evaluate spontaneous motor activity and memory performance of HFD-induced diabetic mice. In differentiated C2C12 muscle cells and HepG2 hepatocellular cells, treatments with LOE and its active component (β-sitosterol) induced significant AMPK phosphorylation. LOE also enhanced uptake of a fluorescent glucose derivative (2-NBDG) and inhibited glucose production in these cells. The beneficial effects of LOE were completely abolished when an AMPK inhibitor, dorsomorphin, was added to the culture system, suggesting that LOE requires AMPK activation for its action in vitro. In streptozotocin (STZ)-induced diabetic mice, we found that both LOE and β-sitosterol induced an anti-hyperglycemic effect comparable to that of metformin, a drug that is commonly prescribed to treat diabetes. Moreover, LOE also improved glycemic control and memory performance of mice fed a HFD. These results indicate that LOE is a potent anti-diabetic intervention that may have potential for future clinical applications. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Anti-diabetic activity of Vaccinium bracteatum Thunb. leaves' polysaccharide in STZ-induced diabetic mice.

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Wang, Li; Zhang, Ying; Xu, Maochao; Wang, Yingyao; Cheng, Sujiao; Liebrecht, Alex; Qian, Haifeng; Zhang, Hui; Qi, Xiguang

2013-10-01

Vaccinium bracteatum Thunb. (VBT) is a traditional Chinese herbal medicine. The anti-diabetic activity of VBT leaves' polysaccharide (VBTLP) is studied in this paper. The results indicated VBTLP had a dose-dependent decrease on the blood glucose (BG) level, and the time effect of VBTLP on BG level was also significant. The insulin level of high dose group (HDG) was significantly higher (p<0.05) than that of model control (MC) group. Compared to MC, HDG and lose dose group (LDG) had significantly lower (p<0.05) TC and LDL-C levels, however, TG and HDL-C levels are similar. Compared to non-diabetic control (NC), HDG and LDG had similar plasma lipid levels except for higher LDL-C level. Although body weights of LDG and HDG were significant lower (p<0.05) than that of NC from week 2 to week 6, they were similar to that of PC. The results indicate VBTLP possesses a potential hypoglycemic effect in streptozotocin-induced diabetic mice. Copyright © 2013 Elsevier B.V. All rights reserved.

Effects of Tang Mai Kang Capsule on Angioneurotic Lesions in Alloxan-Induced Diabetic Mice

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李华; 王军; 高丽君; 郭永成

2004-01-01

The effects of Tang Mai Kang Capsule (糖脉康胶囊) on blood sugar level, gangrene of the tail-tip, pain threshold and learning and memory abilities were investigated in alloxan-induced diabetic mice. The results showed that Tang Mai Kang Capsule could significantly decrease blood sugar level and incidence rate of gangrene of the tail-tip, increase pain threshold, and strengthen learning and memory abilities, suggesting that Tang Mai Kang Capsule functions to decrease blood sugar level and improve the complicated angioneurotic lesions of diabetes.

Antidiabetic, hypolipidemic and hepatoprotective effects of Arctium lappa root’s hydro-alcoholic extract on nicotinamide-streptozotocin induced type 2 model of diabetes in male mice

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Akram Ahangarpour

2017-02-01

Full Text Available Objective: Arctium lappa (burdock, (A. lappa root has hypoglycemic and antioxidative effects, and has been used for treatment of diabetes in tradition medicine. This study was conducted to evaluate the antidiabetic and hypolipidemic properties of A. lappa root extract on nicotinamide-streptozotocin (NA-STZ-induced type2 diabetes in mice.Materials and Methods: In this investigation, 70 adult male NMRI mice (30-35g randomly divided into 7 groups (n=10 as follow: 1-control, 2-type 2 diabetic mice, 3-diabetic mice that received glibenclamide (0.25 mg/kg as an anti-diabetic drug, 4, 5, 6 and 7- diabetic and normal animals that were pre-treated with 200 and 300 mg/kg A. lappa root extract, respectively, for 28 days. Diabetes has been induced by intraperitoneal injection of NA and STZ. Finally, the blood sample was taken and insulin, glucose, SGOT, SGPT, alkaline phosphatase, leptin and lipid levels was evaluated.Results: Induction of diabetes decreased the level of insulin, leptin and high density lipoprotein (HDL and increased the level of other lipids, glucose, and hepatic enzymes significantly (p

Functional immunomics: microarray analysis of IgG autoantibody repertoires predicts the future response of mice to induced diabetes.

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Quintana, Francisco J; Hagedorn, Peter H; Elizur, Gad; Merbl, Yifat; Domany, Eytan; Cohen, Irun R

2004-10-05

One's present repertoire of antibodies encodes the history of one's past immunological experience. Can the present autoantibody repertoire be consulted to predict resistance or susceptibility to the future development of an autoimmune disease? Here, we developed an antigen microarray chip and used bioinformatic analysis to study a model of type 1 diabetes developing in nonobese diabetic male mice in which the disease was accelerated and synchronized by exposing the mice to cyclophosphamide at 4 weeks of age. We obtained sera from 19 individual mice, treated the mice to induce cyclophosphamide-accelerated diabetes (CAD), and found, as expected, that 9 mice became severely diabetic, whereas 10 mice permanently resisted diabetes. We again obtained serum from each mouse after CAD induction. We then analyzed, by using rank-order and superparamagnetic clustering, the patterns of antibodies in individual mice to 266 different antigens spotted on the chip. A selected panel of 27 different antigens (10% of the array) revealed a pattern of IgG antibody reactivity in the pre-CAD sera that discriminated between the mice resistant or susceptible to CAD with 100% sensitivity and 82% specificity (P = 0.017). Surprisingly, the set of IgG antibodies that was informative before CAD induction did not separate the resistant and susceptible groups after the onset of CAD; new antigens became critical for post-CAD repertoire discrimination. Thus, at least for a model disease, present antibody repertoires can predict future disease, predictive and diagnostic repertoires can differ, and decisive information about immune system behavior can be mined by bioinformatic technology. Repertoires matter.

Genistein modulation of streptozotocin diabetes in male B6C3F1 mice can be induced by diet

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Guo, Tai L.; Wang, Yunbiao; Xiong, Tao; Ling, Xiao; Zheng, Jianfeng

2014-01-01

Diet and phytoestrogens affect the development and progression of diabetes. The objective of the present study was to determine if oral exposure to phytoestrogen genistein (GE) by gavage changed blood glucose levels (BGL) through immunomodulation in streptozotocin (STZ)-induced diabetic male B6C3F1 mice fed with three different diets. These three diets were: NTP-2000 diet (NTP), soy- and alfalfa-free 5K96 diet (SOF) and high fat diet (HFD) with 60% of kcal from fat, primarily rendered fat of swine. The dosing regimen for STZ consisted of three 100 mg/kg doses (i.p.): the first dose was administered at approximately 2 weeks following the initiation of daily GE (20 mg/kg) gavage, and the second dose was on day 19 following the first dose, and the third dose was on day 57 following the first dose. In mice on the NTP diet, GE treatment decreased BGL with statistical significances observed on days 33 and 82 following the first STZ injection. In mice fed the HFD diet, GE treatment produced a significant decrease and a significant increase in BGL on days 15 and 89 following the first STZ injection, respectively. In mice fed the SOF diet, GE treatment had no significant effects on BGL. Although GE treatment affected phenotypic distributions of both splenocytes (T cells, B cells, natural killer cells and neutrophils) and thymocytes (CD4/CD8 and CD44/CD25), and their mitochondrial transmembrane potential and generation of reactive oxygen species, indicators of cell death (possibly apoptosis), GE modulation of neutrophils was more consistent with its diabetogenic or anti-diabetic potentials. The differential effects of GE on BGL in male B6C3F1 mice fed with three different diets with varied phytoestrogen contents suggest that the estrogenic properties of this compound may contribute to its modulation of diabetes. - Highlights: • Diets affected streptozotocin-induced diabetes in male B6C3F1 mice. • Genistein modulation of streptozotocin diabetes can be induced by diet. �

Genistein modulation of streptozotocin diabetes in male B6C3F1 mice can be induced by diet

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Guo, Tai L., E-mail: tlguo1@uga.edu [Department of Biosciences and Diagnostic Imaging, College of Veterinary Medicine, University of Georgia, Athens, GA 30602-7382 (United States); Wang, Yunbiao [Department of Biosciences and Diagnostic Imaging, College of Veterinary Medicine, University of Georgia, Athens, GA 30602-7382 (United States); Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102 (China); Xiong, Tao [College of Animal Science, Yangtze University, Jingzhou City, Hubei Province 434025 (China); Ling, Xiao [Institute for Food and Drug Control of Shandong Province, Jinan City, Shandong 250012 (China); Zheng, Jianfeng [Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA 23298-0613 (United States)

2014-11-01

Diet and phytoestrogens affect the development and progression of diabetes. The objective of the present study was to determine if oral exposure to phytoestrogen genistein (GE) by gavage changed blood glucose levels (BGL) through immunomodulation in streptozotocin (STZ)-induced diabetic male B6C3F1 mice fed with three different diets. These three diets were: NTP-2000 diet (NTP), soy- and alfalfa-free 5K96 diet (SOF) and high fat diet (HFD) with 60% of kcal from fat, primarily rendered fat of swine. The dosing regimen for STZ consisted of three 100 mg/kg doses (i.p.): the first dose was administered at approximately 2 weeks following the initiation of daily GE (20 mg/kg) gavage, and the second dose was on day 19 following the first dose, and the third dose was on day 57 following the first dose. In mice on the NTP diet, GE treatment decreased BGL with statistical significances observed on days 33 and 82 following the first STZ injection. In mice fed the HFD diet, GE treatment produced a significant decrease and a significant increase in BGL on days 15 and 89 following the first STZ injection, respectively. In mice fed the SOF diet, GE treatment had no significant effects on BGL. Although GE treatment affected phenotypic distributions of both splenocytes (T cells, B cells, natural killer cells and neutrophils) and thymocytes (CD4/CD8 and CD44/CD25), and their mitochondrial transmembrane potential and generation of reactive oxygen species, indicators of cell death (possibly apoptosis), GE modulation of neutrophils was more consistent with its diabetogenic or anti-diabetic potentials. The differential effects of GE on BGL in male B6C3F1 mice fed with three different diets with varied phytoestrogen contents suggest that the estrogenic properties of this compound may contribute to its modulation of diabetes. - Highlights: • Diets affected streptozotocin-induced diabetes in male B6C3F1 mice. • Genistein modulation of streptozotocin diabetes can be induced by diet. �

Antidiabetic, hypolipidemic and hepatoprotective effects of Arctium lappa root's hydro-alcoholic extract on nicotinamide-streptozotocin induced type 2 model of diabetes in male mice.

Science.gov (United States)

Ahangarpour, Akram; Heidari, Hamid; Oroojan, Ali Akbar; Mirzavandi, Farhang; Nasr Esfehani, Khalil; Dehghan Mohammadi, Zeinab

2017-01-01

Arctium lappa (burdock), (A. lappa) root has hypoglycemic and antioxidative effects, and has been used for treatment of diabetes in tradition medicine. This study was conducted to evaluate the antidiabetic and hypolipidemic properties of A. lappa root extract on nicotinamide-streptozotocin (NA-STZ)-induced type2 diabetes in mice. In this investigation, 70 adult male NMRI mice (30-35g) randomly divided into 7 groups (n=10) as follow: 1-control, 2-type 2 diabetic mice, 3-diabetic mice that received glibenclamide (0.25 mg/kg) as an anti-diabetic drug, 4, 5, 6 and 7- diabetic and normal animals that were pre-treated with 200 and 300 mg/kg A. lappa root extract, respectively, for 28 days. Diabetes has been induced by intraperitoneal injection of NA and STZ. Finally, the blood sample was taken and insulin, glucose, SGOT, SGPT, alkaline phosphatase, leptin and lipid levels was evaluated. Induction of diabetes decreased the level of insulin, leptin and high density lipoprotein (HDL) and increased the level of other lipids, glucose, and hepatic enzymes significantly (plappa root extract, at specific doses, has an anti-diabetic effect through its hypolipidemic and insulinotropic properties. Hence, this plant extract may be beneficial in the treatment of diabetes.

Antihyperglycemic Effects of Fermented and Nonfermented Mung Bean Extracts on Alloxan-Induced-Diabetic Mice

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Swee Keong Yeap

2012-01-01

Full Text Available Mung bean was reported as a potential antidiabetic agent while fermented food has been proposed as one of the major contributors that can reduce the risk of diabetes in Asian populations. In this study, we have compared the normoglycemic effect, glucose-induced hyperglycemic effect, and alloxan-induced hyperglycemic effect of fermented and nonfermented mung bean extracts. Our results showed that fermented mung bean extracts did not induce hypoglycemic effect on normal mice but significantly reduced the blood sugar levels of glucose- and alloxan-induced hyperglycemic mice. The serum levels of cholesterol, triglyceride (TG, and low-density lipoprotein (LDL were also lowered while insulin secretion and antioxidant level as measured by malonaldehyde (MDA assays were significantly improved in the plasma of the fermented mung bean-treated group in alloxan-induced hyperglycemic mouse. These results indicated that fermentation using Mardi Rhizopus sp. strain 5351 inoculums could enhance the antihyperglycemic and the antioxidant effects of mung bean in alloxan-treated mice. The improvement in the antihyperglycemic effect may also be contributed by the increased content of GABA and the free amino acid that are present in the fermented mung bean extracts.

Analysis of the antinociceptive interactions in two-drug combinations of gabapentin, oxcarbazepine and amitriptyline in streptozotocin-induced diabetic mice.

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Tomić, Maja A; Vucković, Sonja M; Stepanović-Petrović, Radica M; Micov, Ana M; Ugresić, Nenad D; Prostran, Milica S; Bosković, Bogdan

2010-02-25

Antiepileptic and antidepressant drugs are the primary treatments for pain relief in diabetic neuropathy. Combination therapy is a valid approach in pain treatment, where a reduction of doses could reduce side effects and still achieve optimal analgesia. We examined the effects of two-drug combinations of gabapentin, oxcarbazepine, and amitriptyline on nociception in diabetic mice and aimed to determine the type of interaction between components. The nociceptive responses in normal and diabetic mice were assessed by the tail-flick test. The testing was performed before and three weeks after the diabetes induction with streptozotocin (150mg/kg; i.p.), when the antinociceptive effects of gabapentin, oxcarbazepine, amitriptyline and their two-drug combinations were examined. Gabapentin (10-40mg/kg; p.o.) and oxcarbazepine (20-80mg/kg; p.o.) produced a significant, dose-dependent antinociception in diabetic mice while amitriptyline (5-60mg/kg; p.o.) produced weak antinociceptive effect. In normal mice, neither of the drugs produced antinociception. Gabapentin and oxcarbazepine, co-administered in fixed-dose fractions of the ED(50) to diabetic mice, induced significant, dose-dependent antinociception. Isobolographic analysis revealed synergistic interaction. Oxcarbazepine (10-60mg/kg; p.o.)+amitriptyline (5mg/kg; p.o.) and gabapentin (10-30mg/kg; p.o.)+amitriptyline (5mg/kg; p.o.) combinations significantly and dose-dependently reduced nociception in diabetic mice. Analysis of the log dose-response curves for oxcarbazepine or gabapentin in a presence of amitriptyline and oxcarbazepine or gabapentin applied alone, revealed a synergism in oxcarbazepine-amitriptyline and additivity in gabapentin-amitriptyline combination. These findings provide new information about the combination therapy of painful diabetic neuropathy and should be explored further in patients with diabetic neuropathy.

A Protein Isolate from Moringa oleifera Leaves Has Hypoglycemic and Antioxidant Effects in Alloxan-Induced Diabetic Mice

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Paulo C. Paula

2017-02-01

Full Text Available Moringa oleifera has been used in traditional medicine to treat diabetes. However, few studies have been conducted to relate its antidiabetic properties to proteins. In this study, a leaf protein isolate was obtained from M. oleifera leaves, named Mo-LPI, and the hypoglycemic and antioxidant effects on alloxan-induced diabetic mice were assessed. Mo-LPI was obtained by aqueous extraction, ammonium sulphate precipitation and dialysis. The electrophoresis profile and proteolytic hydrolysis confirmed its protein nature. Mo-LPI showed hemagglutinating activity, cross-reaction with anti-insulin antibodies and precipitation after zinc addition. Single-dose intraperitoneal (i.p. administration of Mo-LPI (500 mg/kg·bw reduced the blood glucose level (reductions of 34.3%, 60.9% and 66.4% after 1, 3 and 5 h, respectively. The effect of Mo-LPI was also evidenced in the repeated dose test with a 56.2% reduction in the blood glucose level on the 7th day after i.p. administration. Mo-LPI did not stimulate insulin secretion in diabetic mice. Mo-LPI was also effective in reducing the oxidative stress in diabetic mice by a decrease in malondialdehyde level and increase in catalase activity. Mo-LPI (2500 mg/kg·bw did not cause acute toxicity to mice. Mo-LPI is a promising alternative or complementary agent to treat diabetes.

Antidiabetic Effects of Carassius auratus Complex Formula in High Fat Diet Combined Streptozotocin-Induced Diabetic Mice

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Zhi-Hong Wang

2014-01-01

Full Text Available Carassius auratus complex formula, including Carassius auratus, Rhizoma dioscoreae, Lycium chinense, and Rehmannia glutinosa Libosch, is a combination prescription of traditional Chinese medicine, which has always been used to treat diabetes mellitus in ancient China. In this study, we provided experimental evidence for the use of Carassius auratus complex formula in the treatment of high fat diet combined streptozotocin- (STZ- induced type 2 diabetes. Carassius auratus complex formula aqueous extract was prepared and the effects of it on blood glucose, serum insulin, adipose tissue weight, oral glucose tolerance test (OGTT, total cholesterol, and triglyceride (TG levels in mice were measured. Moreover, adiponectin, TG synthesis related gene expressions, and the inhibitory effect of aldose reductase (AR were performed to evaluate its antidiabetic effects. After the 8-week treatment, blood glucose, insulin levels, and adipose tissue weight were significantly decreased. OGTT and HOMA-IR index showed improved glucose tolerance. It could also lower plasma TG, TC, and liver TG levels. Furthermore, Carassius auratus complex formula could inhibit the activity of AR and restore adiponectin expression in serum. Based on these findings, it is suggested that Carassius auratus complex formula possesses potent anti-diabetic effects on high fat diet combined STZ-induced diabetic mice.

Vasoconstrictor role of cyclooxygenase-1-mediated prostacyclin synthesis in non-insulin-dependent diabetic mice induced by high-fat diet and streptozotocin.

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Zhu, Ningxia; Liu, Bin; Luo, Wenhong; Zhang, Yingzhan; Li, Hui; Li, Shasha; Zhou, Yingbi

2014-08-01

This study tested the hypothesis that in diabetic arteries, cyclooxygenase (COX)-1 mediates endothelial prostacyclin (PGI2) synthesis, which evokes vasoconstrictor activity under the pathological condition. Non-insulin-dependent diabetes was induced to C57BL/6 mice and those with COX-1 deficiency (COX-1(-/-) mice) using a high-fat diet in combination with streptozotocin injection. In vitro analyses were performed 3 mo after. Results showed that in diabetic aortas, the endothelial muscarinic receptor agonist ACh evoked an endothelium-dependent production of the PGI2 metabolite 6-keto-PGF1α, which was abolished in COX-1(-/-) mice. Meanwhile, COX-1 deficiency or COX-1 inhibition prevented vasoconstrictor activity in diabetic abdominal aortas, resulting in enhanced relaxation evoked by ACh. In a similar manner, COX-1 deficiency increased the relaxation evoked by ACh in nitric oxide synthase-inhibited diabetic renal arteries. Also, in diabetic abdominal aortas and/or renal arteries, both PGI2 and the COX substrate arachidonic acid evoked contractions similar to those of nondiabetic mice. However, the contraction to arachidonic acid, but not that to PGI2, was abolished in vessels from COX-1(-/-) mice. Moreover, we found that 3 mo after streptozotocin injection, systemic blood pressure increased in diabetic C57BL/6 mice but not in diabetic COX-1(-/-) mice. These results explicitly demonstrate that in the given arteries from non-insulin-dependent diabetic mice, COX-1 remains a major contributor to the endothelial PGI2 synthesis that evokes vasoconstrictor activity under the pathological condition. Also, our data suggest that COX-1 deficiency prevents or attenuates diabetic hypertension in mice, although this could be related to the loss of COX-1-mediated activities derived from both vascular and nonvascular tissues. Copyright © 2014 the American Physiological Society.

iNOS inhibits hair regeneration in obese diabetic (ob/ob) mice.

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Sasaki, Mari; Shinozaki, Shohei; Morinaga, Hironobu; Kaneki, Masao; Nishimura, Emi; Shimokado, Kentaro

2018-07-02

Previous studies have shown that androgenic alopecia is associated with metabolic syndrome and diabetes. However, the detailed mechanism whereby diabetes causes alopecia still remains unclear. We focused on the inflammatory response that is caused by diabetes or obesity, given that inflammation is a risk factor for hair loss. Inducible nitric oxide synthase (iNOS) is known to be upregulated under conditions of acute or chronic inflammation. To clarify the potential role of iNOS in diabetes-related alopecia, we generated obese diabetic iNOS-deficient (ob/ob; iNOS-KO mice). We observed that ob/ob; iNOS-KO mice were potentiated for the transition from telogen (rest phase) to anagen (growth phase) in the hair cycle compared with iNOS-proficient ob/ob mice. To determine the effect of nitric oxide (NO) on the hair cycle, we administered an iNOS inhibitor intraperitoneally (compound 1400 W, 10 mg/kg) or topically (10% aminoguanidine) in ob/ob mice. We observed that iNOS inhibitors promoted anagen transition in ob/ob mice. Next, we administered an NO donor (S-nitrosoglutathione, GSNO), to test whether NO has the telogen elongation effects. The NO donor was sufficient to induce telogen elongation in wild-type mice. Together, our data indicate that iNOS-derived NO plays a role in telogen elongation under the inflammatory conditions associated with diabetes in mice. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

A mixture of extracts from Peruvian plants (black maca and yacon) improves sperm count and reduced glycemia in mice with streptozotocin-induced diabetes.

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Gonzales, Gustavo F; Gonzales-Castañeda, Cynthia; Gasco, Manuel

2013-09-01

We investigated the effect of two extracts from Peruvian plants given alone or in a mixture on sperm count and glycemia in streptozotocin-diabetic mice. Normal or diabetic mice were divided in groups receiving vehicle, black maca (Lepidium meyenii), yacon (Smallanthus sonchifolius) or three mixtures of extracts black maca/yacon (90/10, 50/50 and 10/90%). Normal or diabetic mice were treated for 7 d with each extract, mixture or vehicle. Glycemia, daily sperm production (DSP), epididymal and vas deferens sperm counts in mice and polyphenol content, and antioxidant activity in each extract were assessed. Black maca (BM), yacon and the mixture of extracts reduced glucose levels in diabetic mice. Non-diabetic mice treated with BM and yacon showed higher DSP than those treated with vehicle (p maca/yacon increased DSP, and sperm count in vas deferens and epididymis with respect to non-diabetic and diabetic mice treated with vehicle (p maca, and this was associated with higher antioxidant activity. The combination of two extracts improved glycemic levels and male reproductive function in diabetic mice. Streptozotocin increased 1.43 times the liver weight that was reversed with the assessed plants extracts. In summary, streptozotocin-induced diabetes resulted in reduction in sperm counts and liver damage. These effects could be reduced with BM, yacon and the BM+yacon mixture.

Pathological prolongation of action potential duration as a cause of the reduced alpha-adrenoceptor-mediated negative inotropy in streptozotocin-induced diabetic mice myocardium.

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Kanae, Haruna; Hamaguchi, Shogo; Wakasugi, Yumi; Kusakabe, Taichi; Kato, Keisuke; Namekata, Iyuki; Tanaka, Hikaru

2017-11-01

Effect of pathological prolongation of action potential duration on the α-adrenoceptor-mediated negative inotropy was studied in streptozotocin-induced diabetic mice myocardium. In streptozotocin-treated mouse ventricular myocardium, which had longer duration of action potential than that in control mice, the negative inotropic response induced by phenylephrine was smaller than that in control mice. 4-Aminopyridine prolonged the action potential duration and decreased the negative inotropy in control mice. Cromakalim shortened the action potential duration and increased the negative inotropy in streptozotocin-treated mice. These results suggest that the reduced α-adrenoceptor-mediated inotropy in the diabetic mouse myocardium is partly due to its prolonged action potential. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Antidiabetic, hypolipidemic and hepatoprotective effects of Arctium lappa root’s hydro-alcoholic extract on nicotinamide-streptozotocin induced type 2 model of diabetes in male mice

Science.gov (United States)

Ahangarpour, Akram; Heidari, Hamid; Oroojan, Ali Akbar; Mirzavandi, Farhang; Nasr Esfehani, Khalil; Dehghan Mohammadi, Zeinab

2017-01-01

Objective: Arctium lappa (burdock), (A. lappa) root has hypoglycemic and antioxidative effects, and has been used for treatment of diabetes in tradition medicine. This study was conducted to evaluate the antidiabetic and hypolipidemic properties of A. lappa root extract on nicotinamide-streptozotocin (NA-STZ)-induced type2 diabetes in mice. Materials and Methods: In this investigation, 70 adult male NMRI mice (30-35g) randomly divided into 7 groups (n=10) as follow: 1-control, 2-type 2 diabetic mice, 3-diabetic mice that received glibenclamide (0.25 mg/kg) as an anti-diabetic drug, 4, 5, 6 and 7- diabetic and normal animals that were pre-treated with 200 and 300 mg/kg A. lappa root extract, respectively, for 28 days. Diabetes has been induced by intraperitoneal injection of NA and STZ. Finally, the blood sample was taken and insulin, glucose, SGOT, SGPT, alkaline phosphatase, leptin and lipid levels was evaluated. Results: Induction of diabetes decreased the level of insulin, leptin and high density lipoprotein (HDL) and increased the level of other lipids, glucose, and hepatic enzymes significantly (plappa root extract, at specific doses, has an anti-diabetic effect through its hypolipidemic and insulinotropic properties. Hence, this plant extract may be beneficial in the treatment of diabetes. PMID:28348972

Food restriction by intermittent fasting induces diabetes and obesity and aggravates spontaneous atherosclerosis development in hypercholesterolaemic mice.

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Dorighello, Gabriel G; Rovani, Juliana C; Luhman, Christopher J F; Paim, Bruno A; Raposo, Helena F; Vercesi, Anibal E; Oliveira, Helena C F

2014-03-28

Different regimens of food restriction have been associated with protection against obesity, diabetes and CVD. In the present study, we hypothesised that food restriction would bring benefits to atherosclerosis- and diabetes-prone hypercholesterolaemic LDL-receptor knockout mice. For this purpose, 2-month-old mice were submitted to an intermittent fasting (IF) regimen (fasting every other day) over a 3-month period, which resulted in an overall 20 % reduction in food intake. Contrary to our expectation, epididymal and carcass fat depots and adipocyte size were significantly enlarged by 15, 72 and 68 %, respectively, in the IF mice compared with the ad libitum-fed mice. Accordingly, plasma levels of leptin were 50 % higher in the IF mice than in the ad libitum-fed mice. In addition, the IF mice showed increased plasma levels of total cholesterol (37 %), VLDL-cholesterol (195 %) and LDL-cholesterol (50 %). As expected, in wild-type mice, the IF regimen decreased plasma cholesterol levels and epididymal fat mass. Glucose homeostasis was also disturbed by the IF regimen in LDL-receptor knockout mice. Elevated levels of glycaemia (40 %), insulinaemia (50 %), glucose intolerance and insulin resistance were observed in the IF mice. Systemic inflammatory markers, TNF-α and C-reactive protein, were significantly increased and spontaneous atherosclerosis development were markedly increased (3-fold) in the IF mice. In conclusion, the IF regimen induced obesity and diabetes and worsened the development of spontaneous atherosclerosis in LDL-receptor knockout mice. Although being efficient in a wild-type background, this type of food restriction is not beneficial in the context of genetic hypercholesterolaemia.

Auto-mobilized adult hematopoietic stem cells advance neovasculature in diabetic retinopathy of mice

Institute of Scientific and Technical Information of China (English)

TIAN Bei; LI Xiao-xin; SHEN Li; ZHAO Min; YU Wen-zhen

2010-01-01

Background Hematopoietic stem cells (HSCs) can be used to deliver functionally active angiostatic molecules to the retinal vasculature by targeting active astrocytes and may be useful in targeting pre-angiogenic retinal lesions. We sought to determine whether HSC mobilization can ameliorate early diabetic retinopathy in mice.Methods Mice were devided into four groups: normal mice control group, normal mice HSC-mobilized group, diabetic mice control group and diabetic mice HSC mobilized group. Murine stem cell growth factor (murine SCF) and recombined human granulocyte colony stimulating factor (rhG-csf) were administered to the mice with diabetes and without diabetes for continuous 5 days to induce autologous HSCs mobilization, and subcutaneous injection of physiological saline was used as control. Immunohistochemical double staining was conducted with anti-mouse rat CD31 monoclonal antibody and anti-BrdU rat antibody.Results Marked HSCs clearly increased after SCF plus G-csf-mobilization. Non-mobilized diabetic mice showed more HSCs than normal mice (P=0.032), and peripheral blood significantly increased in both diabetic and normal mice (P=0.000).Diabetic mice showed more CD31 positive capillary vessels (P=0.000) and accelerated endothelial cell regeneration. Only diabetic HSC-mobilized mice expressed both BrdU and CD31 antigens in the endothelial cells of new capillaries.Conclusion Auto-mobilized adult hematopoietic stem cells advance neovasculature in diabetic retinopathy of mice.

Mice deficient in PAPP-A show resistance to the development of diabetic nephropathy.

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Mader, Jessica R; Resch, Zachary T; McLean, Gary R; Mikkelsen, Jakob H; Oxvig, Claus; Marler, Ronald J; Conover, Cheryl A

2013-10-01

We investigated pregnancy-associated plasma protein-A (PAPP-A) in diabetic nephropathy. Normal human kidney showed specific staining for PAPP-A in glomeruli, and this staining was markedly increased in diabetic kidney. To assess the possible contribution of PAPP-A in the development of diabetic nephropathy, we induced diabetes with streptozotocin in 14-month-old WT and Papp-A knockout (KO) mice. Renal histopathology was evaluated after 4 months of stable hyperglycemia. Kidneys from diabetic WT mice showed multiple abnormalities including thickening of Bowman's capsule (100% of mice), increased glomerular size (80% of mice), tubule dilation (80% of mice), and mononuclear cell infiltration (90% of mice). Kidneys of age-matched non-diabetic WT mice had similar evidence of tubule dilation and mononuclear cell infiltration to those of diabetic WT mice, indicating that these changes were predominantly age-related. However, thickened Bowman's capsule and increased glomerular size appeared specific for the experimental diabetes. Kidneys from diabetic Papp-A KO mice had significantly reduced or no evidence of changes in Bowman's capsule thickening and glomerular size. There was also a shift to larger mesangial area and increased macrophage staining in diabetic WT mice compared with Papp-A KO mice. In summary, elevated PAPP-A expression in glomeruli is associated with diabetic nephropathy in humans and absence of PAPP-A is associated with resistance to the development of indicators of diabetic nephropathy in mice. These data suggest PAPP-A as a potential therapeutic target for diabetic nephropathy.

Urtica dioica extract attenuates depressive like behavior and associative memory dysfunction in dexamethasone induced diabetic mice.

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Patel, Sita Sharan; Udayabanu, Malairaman

2014-03-01

Evidences suggest that glucocorticoids results in depression and is a risk factor for type 2 diabetes. Further diabetes induces oxidative stress and hippocampal dysfunction resulting in cognitive decline. Traditionally Urtica dioica has been used for diabetes mellitus and cognitive dysfunction. The present study investigated the effect of the hydroalcoholic extract of Urtica dioica leaves (50 and 100 mg/kg, p.o.) in dexamethasone (1 mg/kg, i.m.) induced diabetes and its associated complications such as depressive like behavior and cognitive dysfunction. We observed that mice administered with chronic dexamethasone resulted in hypercortisolemia, oxidative stress, depressive like behavior, cognitive impairment, hyperglycemia with reduced body weight, increased water intake and decreased hippocampal glucose transporter-4 (GLUT4) mRNA expression. Urtica dioica significantly reduced hyperglycemia, plasma corticosterone, oxidative stress and depressive like behavior as well as improved associative memory and hippocampal GLUT4 mRNA expression comparable to rosiglitazone (5 mg/kg, p.o.). Further, Urtica dioica insignificantly improved spatial memory and serum insulin. In conclusion, Urtica dioica reversed dexamethasone induced hyperglycemia and its associated complications such as depressive like behavior and cognitive dysfunction.

Islet-specific T cell clones transfer diabetes to nonobese diabetic (NOD) F1 mice.

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Peterson, J D; Pike, B; McDuffie, M; Haskins, K

1994-09-15

To investigate diabetes resistance to T cell-mediated disease transfer, we administered islet-specific T cell clones to the F1 progeny of nonobese diabetic (NOD) mice that were crossed with various nondiabetes-prone inbred mouse strains. We investigated four diabetogenic CD4+ T cell clones and all induced insulitis and full development of diabetes in (SWR x NOD)F1, (SJL x NOD)F1, and (C57BL/6 x NOD)F1 mice. In contrast, (BALB/c x NOD)F1 and (CBA x NOD)F1 mice were susceptible to disease transfer by some T cell clones but not others, and (C57/L x NOD)F1 mice seemed to be resistant to both insulitis and disease transfer by all of the clones tested. Disease induced by the T cell clones in susceptible F1 strains was age dependent and could only be observed in recipients younger than 13 days old. Full or partial disease resistance did not correlate with the presence or absence of I-E, different levels of Ag expression in islet cells, or differences in APC function. The results from this study suggest that there may be multiple factors contributing to susceptibility of F1 mice to T cell clone-mediated induction of diabetes, including non-MHC-related genetic background, the immunologic maturity of the recipient, and individual characteristics of the T cell clones.

Akt-mediated cardioprotective effects of aldosterone in type 2 diabetic mice.

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Fazal, Loubina; Azibani, Feriel; Bihry, Nicolas; Coutance, Guillaume; Polidano, Evelyne; Merval, Régine; Vodovar, Nicolas; Launay, Jean-Marie; Delcayre, Claude; Samuel, Jane-Lise

2014-06-01

Studies have shown that aldosterone would have angiogenic effects and therefore would be beneficial in the context of cardiovascular diseases. We thus investigated the potential involvement of aldosterone in triggering a cardiac angiogenic response in the context of type-2 diabetes and the molecular pathways involved. Male 3-wk-old aldosterone synthase (AS)-overexpressing mice and their control wild-type (WT) littermates were fed a standard or high-fat, high-sucrose (HFHS) diet. After 6 mo of diet treatment, mice were euthanized, and cardiac samples were assayed by RT-PCR, immunoblotting, and immunohistology. HFHS diet induced type-2 diabetes in WT (WT-D) and AS (AS-D) mice. VEGFa mRNAs decreased in WT-D (-43%, P<0.05 vs. WT) and increased in AS-D mice (+236%, P< 0.01 vs. WT-D). In WT-D mouse hearts, the proapoptotic p38MAPK was activated (P<0.05 vs. WT and AS-D), whereas Akt activity decreased (-64%, P<0.05 vs. WT). The AS mice, which exhibited a cardiac up-regulation of IGF1-R, showed an increase in Akt phosphorylation when diabetes was induced (P<0.05 vs. WT and AS-D). Contrary to WT-D mice, AS-D mouse hearts did not express inflammatory markers and exhibited a normal capillary density (P<0.05 vs. WT-D). To our knowledge, this is the first study providing new insights into the mechanisms whereby aldosterone prevents diabetes-induced cardiac disorders. © FASEB.

Neuronal human BACE1 knockin induces systemic diabetes in mice.

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Plucińska, Kaja; Dekeryte, Ruta; Koss, David; Shearer, Kirsty; Mody, Nimesh; Whitfield, Phillip D; Doherty, Mary K; Mingarelli, Marco; Welch, Andy; Riedel, Gernot; Delibegovic, Mirela; Platt, Bettina

2016-07-01

β-Secretase 1 (BACE1) is a key enzyme in Alzheimer's disease pathogenesis that catalyses the amyloidogenic cleavage of amyloid precursor protein (APP). Recently, global Bace1 deletion was shown to protect against diet-induced obesity and diabetes, suggesting that BACE1 is a potential regulator of glucose homeostasis. Here, we investigated whether increased neuronal BACE1 is sufficient to alter systemic glucose metabolism, using a neuron-specific human BACE1 knockin mouse model (PLB4). Glucose homeostasis and adiposity were determined by glucose tolerance tests and EchoMRI, lipid species were measured by quantitative lipidomics, and biochemical and molecular alterations were assessed by western blotting, quantitative PCR and ELISAs. Glucose uptake in the brain and upper body was measured via (18)FDG-PET imaging. Physiological and molecular analyses demonstrated that centrally expressed human BACE1 induced systemic glucose intolerance in mice from 4 months of age onward, alongside a fatty liver phenotype and impaired hepatic glycogen storage. This diabetic phenotype was associated with hypothalamic pathology, i.e. deregulation of the melanocortin system, and advanced endoplasmic reticulum (ER) stress indicated by elevated central C/EBP homologous protein (CHOP) signalling and hyperphosphorylation of its regulator eukaryotic translation initiation factor 2α (eIF2α). In vivo (18)FDG-PET imaging further confirmed brain glucose hypometabolism in these mice; this corresponded with altered neuronal insulin-related signalling, enhanced protein tyrosine phosphatase 1B (PTP1B) and retinol-binding protein 4 (RBP4) levels, along with upregulation of the ribosomal protein and lipid translation machinery. Increased forebrain and plasma lipid accumulation (i.e. ceramides, triacylglycerols, phospholipids) was identified via lipidomics analysis. Our data reveal that neuronal BACE1 is a key regulator of metabolic homeostasis and provide a potential mechanism for the high

Thioredoxin-1 overexpression in transgenic mice attenuates streptozotocin-induced diabetic osteopenia: a novel role of oxidative stress and therapeutic implications.

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Hamada, Yasuhiro; Fujii, Hideki; Kitazawa, Riko; Yodoi, Junji; Kitazawa, Sohei; Fukagawa, Masafumi

2009-05-01

Diabetes mellitus is associated with increased risk of osteopenia and bone fracture. However, the mechanisms accounting for diabetic bone disorder are unclear. We have previously reported that streptozotocin-induced diabetic mice develop low turnover osteopenia associated with increased oxidative stress in the diabetic condition. To determine the role of oxidative stress in the development of diabetic osteopenia, we presently investigated the effect of overexpression of thioredoxin-1 (TRX), a major intracellular antioxidant, on the development of diabetic osteopenia, using TRX transgenic mice (TRX-Tg). TRX-Tg are C57BL/6 mice that carry the human TRX transgene under the control of beta-actin promoter. Eight-week-old male TRX-Tg mice and wild type (WT) littermates were intraperitoneally injected with either streptozotocin or vehicle. Mice were grouped as 1) non-diabetic WT, 2) non-diabetic TRX-Tg, 3) diabetic WT, and 4) diabetic TRX-Tg. After 12 weeks of streptozotocin treatment, oxidative stress on the whole body and bone was evaluated, and the physical properties of the femora, and histomorphometry parameters of the tibiae were assessed. TRX overexpression did not affect either body weight or hemoglobin A1c levels. There were no significant differences in renal function and in serum levels of calcium, phosphate, and intact parathyroid hormone among the four groups. On the other hand, urinary excretion of 8-hydroxydeoxyguanosine (8-OHdG), a marker of oxidative DNA damage, was significantly elevated in diabetic WT and attenuated in diabetic TRX-Tg. Immunohistochemical staining for 8-OHdG revealed marked intensity in the bone tissue of diabetic WT compared with non-diabetic WT, while staining was attenuated in diabetic TRX-Tg. TRX overexpression partially restored reduced bone mineral density and prevented the suppression of bone formation observed in diabetic WT. Increased oxidative stress in diabetic condition contributes to the development of diabetic osteopenia

Diabetes Mellitus Induces Bone Marrow Microangiopathy

NARCIS (Netherlands)

Oikawa, Atsuhiko; Siragusa, Mauro; Quaini, Federico; Mangialardi, Giuseppe; Katare, Rajesh G.; Caporali, Andrea; van Buul, Jaap D.; van Alphen, Floris P. J.; Graiani, Gallia; Spinetti, Gaia; Kraenkel, Nicolle; Prezioso, Lucia; Emanueli, Costanza; Madeddu, Paolo

2010-01-01

Objective-The impact of diabetes on the bone marrow (BM) microenvironment was not adequately explored. We investigated whether diabetes induces microvascular remodeling with negative consequence for BM homeostasis. Methods and Results-We found profound structural alterations in BM from mice with

Multiple mechanisms involved in diabetes protection by lipopolysaccharide in non-obese diabetic mice

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Wang, Jun [Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Department of Pharmacology, College of Medicine, Wuhan University of Science and Technology, Wuhan (China); Cao, Hui [Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Wang, Hongjie [Section of Neurobiology, Torrey Pines Institute for Molecular Studies, Port Saint Lucie, FL (United States); Yin, Guoxiao; Du, Jiao; Xia, Fei; Lu, Jingli [Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Xiang, Ming, E-mail: xiangming@mails.tjmu.edu.cn [Department of Pharmacology, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China)

2015-06-15

Toll-like receptor 4 (TLR4) activation has been proposed to be important for islet cell inflammation and eventually β cell loss in the course of type 1 diabetes (T1D) development. However, according to the “hygiene hypothesis”, bacterial endotoxin lipopolysaccharide (LPS), an agonist on TLR4, inhibits T1D progression. Here we investigated possible mechanisms for the protective effect of LPS on T1D development in non-obese diabetic (NOD) mice. We found that LPS administration to NOD mice during the prediabetic state neither prevented nor reversed insulitis, but delayed the onset and decreased the incidence of diabetes, and that a multiple-injection protocol is more effective than a single LPS intervention. Further, LPS administration suppressed spleen T lymphocyte proliferation, increased the generation of CD4{sup +}CD25{sup +}Foxp3{sup +} regulatory T cells (Tregs), reduced the synthesis of strong Th1 proinflammatory cytokines, and downregulated TLR4 and its downstream MyD88-dependent signaling pathway. Most importantly, multiple injections of LPS induced a potential tolerogenic dendritic cell (DC) subset with low TLR4 expression without influencing the DC phenotype. Explanting DCs from repeated LPS-treated NOD mice into NOD/SCID diabetic mice conferred sustained protective effects against the progression of diabetes in the recipients. Overall, these results suggest that multiple mechanisms are involved in the protective effects of LPS against the development of diabetes in NOD diabetic mice. These include Treg induction, down-regulation of TLR4 and its downstream MyD88-dependent signaling pathway, and the emergence of a potential tolerogenic DC subset. - Highlights: • Administration of lipopolysaccharide (LPS) prevented type 1 diabetes in NOD mice. • Downregulating TLR4 level and MyD88-dependent pathway contributed to protection of LPS. • LPS administration also hampered DC maturation and promoted Treg differentiation.

Multiple mechanisms involved in diabetes protection by lipopolysaccharide in non-obese diabetic mice

International Nuclear Information System (INIS)

Wang, Jun; Cao, Hui; Wang, Hongjie; Yin, Guoxiao; Du, Jiao; Xia, Fei; Lu, Jingli; Xiang, Ming

2015-01-01

Toll-like receptor 4 (TLR4) activation has been proposed to be important for islet cell inflammation and eventually β cell loss in the course of type 1 diabetes (T1D) development. However, according to the “hygiene hypothesis”, bacterial endotoxin lipopolysaccharide (LPS), an agonist on TLR4, inhibits T1D progression. Here we investigated possible mechanisms for the protective effect of LPS on T1D development in non-obese diabetic (NOD) mice. We found that LPS administration to NOD mice during the prediabetic state neither prevented nor reversed insulitis, but delayed the onset and decreased the incidence of diabetes, and that a multiple-injection protocol is more effective than a single LPS intervention. Further, LPS administration suppressed spleen T lymphocyte proliferation, increased the generation of CD4 + CD25 + Foxp3 + regulatory T cells (Tregs), reduced the synthesis of strong Th1 proinflammatory cytokines, and downregulated TLR4 and its downstream MyD88-dependent signaling pathway. Most importantly, multiple injections of LPS induced a potential tolerogenic dendritic cell (DC) subset with low TLR4 expression without influencing the DC phenotype. Explanting DCs from repeated LPS-treated NOD mice into NOD/SCID diabetic mice conferred sustained protective effects against the progression of diabetes in the recipients. Overall, these results suggest that multiple mechanisms are involved in the protective effects of LPS against the development of diabetes in NOD diabetic mice. These include Treg induction, down-regulation of TLR4 and its downstream MyD88-dependent signaling pathway, and the emergence of a potential tolerogenic DC subset. - Highlights: • Administration of lipopolysaccharide (LPS) prevented type 1 diabetes in NOD mice. • Downregulating TLR4 level and MyD88-dependent pathway contributed to protection of LPS. • LPS administration also hampered DC maturation and promoted Treg differentiation

Evaluation of protective effect of cactus pear seed oil (Opuntia ficus-indica L. MILL.) against alloxan-induced diabetes in mice.

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Berraaouan, Ali; Abderrahim, Ziyyat; Hassane, Mekhfi; Abdelkhaleq, Legssyer; Mohammed, Aziz; Mohamed, Bnouham

2015-07-01

To evaluate the in vitro antioxidant power of cactus pear seed oil [Opuntia ficus-indica L. MILL. (CPSO)] and its protective effect against chemically induced diabetes mellitus in mice. The in vitro antioxidant effect of CPSO was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging assay. The preventive effect was conducted on Swiss albino mice treated with CPSO (2 mL/kg, per os), before and after a single intraperitoneal alloxan administration (100 mg/kg). Survival rate, body weight and fasting blood glucose were measured and histopathological analysis of pancreas was performed to evaluate alloxan-induced tissue injuries. CPSO exhibited an antioxidant effect in DPPH scavenging assay. Moreover, the administration of CPSO (2 mL/kg) significantly attenuated alloxan-induced death and hyperglycemia (P < 0.001) in treated mice. Morphometric study of pancreas revealed that CPSO significantly protected islets of langerhans against alloxan induced-tissue alterations. Based on theses results, CPSO can prevente alloxan-induced-diabetes by quenching free radicals produced by alloxan and inhibiting tissue injuries in pancreatic β-cells. Copyright © 2015 Hainan Medical College. Production and hosting by Elsevier B.V. All rights reserved.

Anti-Glycemic and Anti-Hepatotoxic Effects of Mangosteen Vinegar Rind from Garcinia mangostana Against HFD/STZ-Induced Type II Diabetes in Mice

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Karim Naymul

2018-06-01

Full Text Available This study focuses on anti-glycemic and anti-hepatotoxic effects of mangosteen vinegar rind (MVR on five weeks high-fat diet (HFD / single dose streptozotocin (STZ 30 mg/kg BW induced male ICR diabetic mice. Mice were randomly divided into five groups (n=6, normal control, diabetic control, and diabetic groups treated with MVR 100, 200 mg/kg BW and glibenclamide 60 mg/kg BW for one week. After the treatment, lipid profile, glycogen and bilirubin contents, oxidative damage (malondialdehyde, MDA, aspartate aminotransferase (AST and alanine aminotransferase (ALT activities, antioxidant enzymes: superoxide dismutase (SOD, catalase (CAT were measured in plasma and/or liver tissues. MVR and glibenclamide treatment to HFD/STZ-induced diabetic mice significantly reduced their plasma glucose, plasma lipid profile, and hepatic lipid profile (P<0.05. Increased hepatic glycogen content indicates improvement of insulin sensitivity. Moreover, oxidative damage markers were ameliorated in MVR- and glibenclamide-treated groups compared to the diabetic control group. MVR with phenolic compounds content of 75 mg GAE/g dry weight and antioxidant potential of 303 mmol/L Trolox/g dry weight acted as a hepatoprotective agent against oxidative damage.

Antidiabetic and protective effects of the aqueous extract of Arbutus unedo L. in streptozotocin-nicotinamide-induced diabetic mice.

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Mrabti, Hanae Naceiri; Sayah, Karima; Jaradat, Nidal; Kichou, Faouzi; Ed-Dra, Abdelaziz; Belarj, Badiaa; Cherrah, Yahia; Faouzi, My El Abbes

2018-02-21

Background Diabetes mellitus (DM) is currently a major health problem and the most common chronic disease worldwide. Traditional medicinal plants remedies remain a potential adjunct therapy to maintain better glycemic control while also imparting few side-effects. Arbutus unedo L. has been traditionally used to manage several diseases including diabetes. This study was undertaken to contribute the validation of the traditional use of Arbutus unedoL. (Ericaceae) in the treatment of diabetes. Methods In-vitro antidiabetic effect of the A. unedo roots aqueous extract was conducted using α-glucosidase and α-amylase assays. While in-vivo antidiabetic activity was conducted using streptozotocin-nicotinamide (STZ-NA) induced diabetic mice. Diabetic animals were orally administered the aqueous extract in 500 mg/kg of body weight to assess the antidiabetic effect. The blood glucose level and body weight of the experimental animals were monitored for 4 weeks. In addition, the histopathological examination of the treated mice pancreas was also conducted to observe the changes of β-cells during the treatment process. Results The extract produced a significant decrease in blood glucose level in diabetic mice. This decrease was equivalent to that which observed in mice treated with a standard after 2-4 weeks. In addition, the plant extract exhibited a potent inhibitory effect on α-amylase and α-glucosidase activity with IC50 values of 730.15±0.25 μg/mL and 94.81±5.99 μg/mL, respectively. Moreover, the histopathologic examination of the pancreas showed a restoration of normal pancreatic islet cell architecture which observed in the diabetic mice treated with plant extract. Conclusions The aqueous A. unedo roots extract has a significant in vitro and in vivo antidiabetic effects and improves metabolic alterations. The revealed results justify its traditional medicinal use.

Hypertension is a conditional factor for the development of cardiac hypertrophy in type 2 diabetic mice.

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Marc van Bilsen

Full Text Available BACKGROUND: Type 2 diabetes is frequently associated with co-morbidities, including hypertension. Here we investigated if hypertension is a critical factor in myocardial remodeling and the development of cardiac dysfunction in type 2 diabetic db/db mice. METHODS: Thereto, 14-wks-old male db/db mice and non-diabetic db/+ mice received vehicle or angiotensin II (AngII for 4 wks to induce mild hypertension (n = 9-10 per group. Left ventricular (LV function was assessed by serial echocardiography and during a dobutamine stress test. LV tissue was subjected to molecular and (immunohistochemical analysis to assess effects on hypertrophy, fibrosis and inflammation. RESULTS: Vehicle-treated diabetic mice neither displayed marked myocardial structural remodeling nor cardiac dysfunction. AngII-treatment did not affect body weight and fasting glucose levels, and induced a comparable increase in blood pressure in diabetic and control mice. Nonetheless, AngII-induced LV hypertrophy was significantly more pronounced in diabetic than in control mice as assessed by LV mass (increase +51% and +34%, respectively, p<0.01 and cardiomyocyte size (+53% and +31%, p<0.001. This was associated with enhanced LV mRNA expression of markers of hypertrophy and fibrosis and reduced activation of AMP-activated protein kinase (AMPK, while accumulation of Advanced Glycation End products (AGEs and the expression levels of markers of inflammation were not altered. Moreover, AngII-treatment reduced LV fractional shortening and contractility in diabetic mice, but not in control mice. CONCLUSIONS: Collectively, the present findings indicate that type 2 diabetes in its early stage is not yet associated with adverse cardiac structural changes, but already renders the heart more susceptible to hypertension-induced hypertrophic remodeling.

Mechanisms of Diabetes-Induced Endothelial Cell Senescence: Role of Arginase 1

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Esraa Shosha

2018-04-01

Full Text Available We have recently found that diabetes-induced premature senescence of retinal endothelial cells is accompanied by NOX2-NADPH oxidase-induced increases in the ureohydrolase enzyme arginase 1 (A1. Here, we used genetic strategies to determine the specific involvement of A1 in diabetes-induced endothelial cell senescence. We used A1 knockout mice and wild type mice that were rendered diabetic with streptozotocin and retinal endothelial cells (ECs exposed to high glucose or transduced with adenovirus to overexpress A1 for these experiments. ABH [2(S-Amino-6-boronohexanoic acid] was used to inhibit arginase activity. We used Western blotting, immunolabeling, quantitative PCR, and senescence associated β-galactosidase (SA β-Gal activity to evaluate senescence. Analyses of retinal tissue extracts from diabetic mice showed significant increases in mRNA expression of the senescence-related proteins p16INK4a, p21, and p53 when compared with non-diabetic mice. SA β-Gal activity and p16INK4a immunoreactivity were also increased in retinal vessels from diabetic mice. A1 gene deletion or pharmacological inhibition protected against the induction of premature senescence. A1 overexpression or high glucose treatment increased SA β-Gal activity in cultured ECs. These results demonstrate that A1 is critically involved in diabetes-induced senescence of retinal ECs. Inhibition of arginase activity may therefore be an effective therapeutic strategy to alleviate diabetic retinopathy by preventing premature senescence.

Arsenic induces diabetic effects through beta-cell dysfunction and increased gluconeogenesis in mice

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Liu, Su; Guo, Xuechao; Wu, Bing; Yu, Haiyan; Zhang, Xuxiang; Li, Mei

2014-11-01

Arsenic as a potential risk factor for type 2 diabetes has been received attention recently. However, the roles of arsenic on development of diabetes are unclear. In this study, we compared the influences of inorganic arsenic (iAs) on normal and diabetic mice by systems toxicology approaches. Although iAs exposure did not change glucose tolerance in normal mice, it caused the pancreatic β-cell dysfunction and increased gluconeogenesis and oxidative damages in liver. However, iAs exposure worsened the glucose tolerance in diabetic mice, which might be due to increased gluconeogenesis and impairment of pancreatic β-cell function. It is interesting that iAs exposure could improve the insulin sensitivity based on the insulin tolerance testing by the activation of glucose uptake-related genes and enzymes in normal and diabetic individuals. Our data suggested that iAs exposure could cause pre-diabetic effects by altering the lipid metabolism, gluconeogenesis and insulin secretion in normal individual, and worsen diabetic effects in diabetes individual by these processes. Insulin resistance might be not the reason of diabetic effects caused by iAs, indicating that mechanism of the diabetogenic effects of iAs exposure is different from the mechanism associated with traditional risk factors (such as obesity)-reduced type 2 diabetes.

Arsenic induces diabetic effects through beta-cell dysfunction and increased gluconeogenesis in mice.

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Liu, Su; Guo, Xuechao; Wu, Bing; Yu, Haiyan; Zhang, Xuxiang; Li, Mei

2014-11-04

Arsenic as a potential risk factor for type 2 diabetes has been received attention recently. However, the roles of arsenic on development of diabetes are unclear. In this study, we compared the influences of inorganic arsenic (iAs) on normal and diabetic mice by systems toxicology approaches. Although iAs exposure did not change glucose tolerance in normal mice, it caused the pancreatic β-cell dysfunction and increased gluconeogenesis and oxidative damages in liver. However, iAs exposure worsened the glucose tolerance in diabetic mice, which might be due to increased gluconeogenesis and impairment of pancreatic β-cell function. It is interesting that iAs exposure could improve the insulin sensitivity based on the insulin tolerance testing by the activation of glucose uptake-related genes and enzymes in normal and diabetic individuals. Our data suggested that iAs exposure could cause pre-diabetic effects by altering the lipid metabolism, gluconeogenesis and insulin secretion in normal individual, and worsen diabetic effects in diabetes individual by these processes. Insulin resistance might be not the reason of diabetic effects caused by iAs, indicating that mechanism of the diabetogenic effects of iAs exposure is different from the mechanism associated with traditional risk factors (such as obesity)-reduced type 2 diabetes.

Prophylactic fenbendazole therapy does not affect the incidence and onset of type 1 diabetes in non-obese diabetic mice.

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Franke, Deanna D H; Shirwan, Haval

2006-03-01

Fenbendazole (FBZ) is a common, highly efficacious broad-spectrum anthelmintic drug used to treat and limit rodent pinworm infections. However, the effect of its prophylactic use on the immune response of rodents is largely undefined. The non-obese diabetic (NOD) mouse is a model commonly used to study type 1 diabetes (T1D). Parasitic infections will inhibit diabetes development in NOD mice; thus, in the presence of contamination, prophylactic treatment with anthelmintics must be considered to maintain experimental research. Herein, we investigated the prophylactic use of FBZ in NOD mice to determine its effect on the incidence and onset of diabetes, lymphocyte sub-populations and T cell proliferative responses. NOD mice were separated into control and treatment groups. The treatment group received a diet containing FBZ. Animals were monitored for the incidence and onset of T1D. At matched time points, diabetic and non-diabetic mice were killed and splenic lymphocytes analyzed for various cell sub-populations and mitogen-induced proliferative responses using flow cytometry. Treated and control mice were monitored >23 weeks with no detectable effects on the incidence or onset of diabetes. Moreover, no significant differences were detected in lymphocyte sub-populations and mitogen-induced CD4(+) and CD8(+) proliferative responses between control and treatment groups. These results suggest that prophylactic FBZ treatment does not significantly alter the incidence or onset of diabetes in NOD mice. The prophylactic use of FBZ, therefore, presents a viable approach for the prevention of pinworm infection in precious experimental animals with substantial scientific and economic benefits.

Softened food reduces weight loss in the streptozotocin-induced male mouse model of diabetic nephropathy

DEFF Research Database (Denmark)

Nørgaard, Sisse A; Sand, Fredrik W; Sørensen, Dorte B

2018-01-01

The streptozotocin (STZ)-induced diabetic mouse is a widely used model of diabetes and diabetic nephropathy (DN). However, it is a well-known issue that this model is challenged by high weight loss, which despite supportive measures often results in high euthanization rates. To overcome...... these issues, we hypothesized that supplementing STZ-induced diabetic mice with water-softened chow in addition to normal chow would reduce weight loss, lower the need for supportive treatment, and reduce the number of mice reaching the humane endpoint of 20% weight loss. In a 15 week STZ-induced DN study we...... demonstrated that diabetic male mice receiving softened chow had reduced acute weight loss following STZ treatment ( p = 0.045) and additionally fewer mice were euthanized due to weight loss. By supplementing the diabetic mice with softened chow, no mice reached 20% weight loss whereas 37.5% of the mice...

The Protective Role of Curcumin against Gamma-Irradiation Induced Oxidative Stress in Diabetic Mice

International Nuclear Information System (INIS)

Nagiub, N.I.; Alkady, M.M.; Emam, W.A.

2012-01-01

The present work was aimed to evaluate the radioprotective effect of curcumin (CMN), a yellow pigment of turmeric on γ-radiation (IRR)-induced toxicity in diabetic mice and evaluate the anti-hyper glycemic properties of this compound on streptozotocin (STZ) (65 mg/kg of body weight)-induced diabetes. Serum lipid profiles, glucose level and Tumor necrosis factor-α (TNF-α) were determined. The level of blood glucose was elevated in diabetic animals. Circulatory lipid profiles, and TNF-α were increased significantly. Pretreatment with CMN (200 mg/kg, i.p.) for 5 consecutive days, resulted in a significant decrease in the levels of blood glucose and lipid profiles along with a significant decrease in the levels of TNF-α. The histological results obtained revealed that exposure to ionizing radiation or treatment with STZ caused histopathological damage, in the eye tissue, manifested as congestion in retinal blood capillaries, vacuolation in ganglionic cells and degeneration in nuclear cells of retina. The lens became coagulated, homogenous and oesinophilic. While the cornea showed vacuolations in its epithelium, edema and hyalinosis of substantia propria. Administration of CMN revealed a remarkable protective effect in biochemical and histological levels. Thus, pretreatment with CMN helps in protecting eye tissues against IRR and/or diabetic-induced cellular damage and can be developed in near future as an effective radioprotector during radiotherapy.

Evaluation of Anticonvulsive ٍEffect of Magnesium Oxide Nanoparticles in Comparison with Conventional MgO in Diabetic and Non-diabetic Male Mice

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Leila Jahangiri

2014-05-01

Full Text Available Introduction: Some studies show magnesium has anticonvulsive effect in some animal models. Despite of the availability of well-studied anticonvulsant drugs, this evaluation was not carried on new kind of magnesium supplement, magnesium oxide nanoparticles (nMgO. According to the interaction between magnesium and convulsion, this study was designed to evaluate the effect of nMgO on strychnine-induced convulsive model in compared to its conventional in diabetic and normal mice. Methods: Healthy male albino mice were divided to 10 groups. Diabete mellitus was induced by streptozocin in 5 groups. Conventional and nanoparticle MgO (5&10mg/kg in presence and absence diabetes injected to mice, then strychnine injected and onset of convulsions and time of death were measured after strychnine administration. Results: Convulsive parameters did not change in normal and diabetic mice. cMgO pretreatment did not have anticonvulsant effect in strychnine-induced convulsion in normal and diabetic mice. But nMgO significantly changed convulsion onset and death time after strychnine administration in normal and diabetic status. Discussion: According to our results It seems that nMgO may be important in prevention or treatment of epilepsy and has more efficacy than its conventional form to showing anticonvulsive effect that probably is related to the physicochemical properties of nMgO, specially in diabetic subjects, a point that need to further investigation.

Characterization of Momordica charantia L. polysaccharide and its protective effect on pancreatic cells injury in STZ-induced diabetic mice.

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Zhang, Cong; Chen, Hongman; Bai, Weiqi

2018-04-10

A polysaccharide with a molecular weight of 13,029Da was isolated from Momordica charantia (MCP) fruit and purified by ion-exchange and size-exclusion chromatography. The isolated polysaccharide MCPIIa contained L-Rha, D-GalA, D-Gal, D-Xyl, L-Ara in a molar ratio of 12:3.05:19.89:5.95:56. IR spectrum and NMR studies indicated that the MCPIIa sugar units were linked, via β-glycosidic bonds, to a large number of arabinofuranose, glucuronic acid, and xylopyranosyl residues. In addition, the hypoglycemic effect of MCPIIa was investigated in streptozotocin (STZ)-induced diabetic mice. After STZ-induction, MCPIIa (100, 200, or 300mg/kg body weight) was administered orally, once daily, for 28days. Glycemia in STZ-diabetogenic mice was significantly reduced, and compared with diabetes mellitus (DM) mice, serum insulin concentration increased significantly, following MCPIIa administration. Transmission electron microscopy showed an alleviation of STZ-lesions in pancreatic tissue from mice treated with MCPIIa. These results indicate that MCPIIa may be useful as an anti-diabetic agent. Copyright © 2018 Elsevier B.V. All rights reserved.

Valsartan ameliorates podocyte loss in diabetic mice through the Notch pathway.

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Gao, Feng; Yao, Min; Cao, Yanping; Liu, Shuxia; Liu, Qingjuan; Duan, Huijun

2016-05-01

The Notch pathway is known to be linked to diabetic nephropathy (DN); however, its underlying mechanism was poorly understood. In the present study, we examined the effect of Valsartan, an angiotensin II type 1 receptor antagonist, on the Notch pathway and podocyte loss in DN. Diabetes was induced in mice by an intraperitoneal injection of streptozotocin and and this was followed by treatment with Valsartan. Levels of blood glucose, kidney weight and body weight, as well as proteinuria were measured. Samples of the kidneys were also histologically examined. The relative levels of Jagged1, Notch1, Notch intracellular domain 1 (NICD1), Hes family BHLH transcription factor 1 (Hes1) and Hes-related family BHLH transcription factor with YRPW motif 1 expression (Hey1) in the glomeruli were determined by immunohistochemical analysis, western blot analysis and RT-qPCR. The B-Cell CLL/Lymphoma 2 (Bcl-2) and p53 pathways were examined by western blot analysis. Apoptosis and detachment of podocytes from the glomerular basement membrane were examined using a TUNEL assay, flow cytometric analysis and ELISA. The number of podocytes was quantified by measuring Wilms tumor-1 (WT-1) staining. We noted that the expression of Jagged1, Notch1, NICD1, Hes1 and Hey1 was increased in a time-dependent manner in the glomeruli of mice with streptozotocin (STZ)-induced diabetes. Moreover, in diabetic mice, Valsartan significantly reduced kidney weight and proteinuria, and mitigated the pathogenic processes in the kidneys. Valsartan also inhibited the activation of Notch, Bcl-2 and p53 pathways and ameliorated podocyte loss in the glomeruli of mice with STZ-induced diabetes. Taken together, these findings indicated that Valsartan exerted a beneficial effect on reducing podocyte loss, which is associated with inhibition of Notch pathway activation in the glomeruli of diabetic mice.

Chronic ingestion of advanced glycation end products induces degenerative spinal changes and hypertrophy in aging pre-diabetic mice.

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Illien-Jünger, Svenja; Lu, Young; Qureshi, Sheeraz A; Hecht, Andrew C; Cai, Weijing; Vlassara, Helen; Striker, Gary E; Iatridis, James C

2015-01-01

Intervertebral disc (IVD) degeneration and pathological spinal changes are major causes of back pain, which is the top cause of global disability. Obese and diabetic individuals are at increased risk for back pain and musculoskeletal complications. Modern diets contain high levels of advanced glycation end products (AGEs), cyto-toxic components which are known contributors to obesity, diabetes and accelerated aging pathologies. There is little information about potential effects of AGE rich diet on spinal pathology, which may be a contributing cause for back pain which is common in obese and diabetic individuals. This study investigated the role of specific AGE precursors (e.g. methylglyoxal-derivatives (MG)) on IVD and vertebral pathologies in aging C57BL6 mice that were fed isocaloric diets with standard (dMG+) or reduced amounts of MG derivatives (dMG-; containing 60-70% less dMG). dMG+ mice exhibited a pre-diabetic phenotype, as they were insulin resistant but not hyperglycemic. Vertebrae of dMG+ mice displayed increased cortical-thickness and cortical-area, greater MG-AGE accumulation and ectopic calcification in vertebral endplates. IVD morphology of dMG+ mice exhibited ectopic calcification, hypertrophic differentiation and glycosaminoglycan loss relative to dMG- mice. Overall, chronic exposure to dietary AGEs promoted age-accelerated IVD degeneration and vertebral alterations involving ectopic calcification which occurred in parallel with insulin resistance, and which were prevented with dMG- diet. This study described a new mouse model for diet-induced spinal degeneration, and results were in support of the hypothesis that chronic AGE ingestion could be a factor contributing to a pre-diabetic state, ectopic calcifications in spinal tissues, and musculoskeletal complications that are more generally known to occur with chronic diabetic conditions.

Chronic ingestion of advanced glycation end products induces degenerative spinal changes and hypertrophy in aging pre-diabetic mice.

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Svenja Illien-Jünger

Full Text Available Intervertebral disc (IVD degeneration and pathological spinal changes are major causes of back pain, which is the top cause of global disability. Obese and diabetic individuals are at increased risk for back pain and musculoskeletal complications. Modern diets contain high levels of advanced glycation end products (AGEs, cyto-toxic components which are known contributors to obesity, diabetes and accelerated aging pathologies. There is little information about potential effects of AGE rich diet on spinal pathology, which may be a contributing cause for back pain which is common in obese and diabetic individuals. This study investigated the role of specific AGE precursors (e.g. methylglyoxal-derivatives (MG on IVD and vertebral pathologies in aging C57BL6 mice that were fed isocaloric diets with standard (dMG+ or reduced amounts of MG derivatives (dMG-; containing 60-70% less dMG. dMG+ mice exhibited a pre-diabetic phenotype, as they were insulin resistant but not hyperglycemic. Vertebrae of dMG+ mice displayed increased cortical-thickness and cortical-area, greater MG-AGE accumulation and ectopic calcification in vertebral endplates. IVD morphology of dMG+ mice exhibited ectopic calcification, hypertrophic differentiation and glycosaminoglycan loss relative to dMG- mice. Overall, chronic exposure to dietary AGEs promoted age-accelerated IVD degeneration and vertebral alterations involving ectopic calcification which occurred in parallel with insulin resistance, and which were prevented with dMG- diet. This study described a new mouse model for diet-induced spinal degeneration, and results were in support of the hypothesis that chronic AGE ingestion could be a factor contributing to a pre-diabetic state, ectopic calcifications in spinal tissues, and musculoskeletal complications that are more generally known to occur with chronic diabetic conditions.

Prasugrel suppresses development of lithium-induced nephrogenic diabetes insipidus in mice.

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Zhang, Yue; Peti-Peterdi, János; Brandes, Anna U; Riquier-Brison, Anne; Carlson, Noel G; Müller, Christa E; Ecelbarger, Carolyn M; Kishore, Bellamkonda K

2017-06-01

Previously, we localized ADP-activated P2Y 12 receptor (R) in rodent kidney and showed that its blockade by clopidogrel bisulfate (CLPD) attenuates lithium (Li)-induced nephrogenic diabetes insipidus (NDI). Here, we evaluated the effect of prasugrel (PRSG) administration on Li-induced NDI in mice. Both CLPD and PRSG belong to the thienopyridine class of ADP receptor antagonists. Groups of age-matched adult male B6D2 mice (N = 5/group) were fed either regular rodent chow (CNT), or with added LiCl (40 mmol/kg chow) or PRSG in drinking water (10 mg/kg bw/day) or a combination of LiCl and PRSG for 14 days and then euthanized. Water intake and urine output were determined and blood and kidney tissues were collected and analyzed. PRSG administration completely suppressed Li-induced polydipsia and polyuria and significantly prevented Li-induced decreases in AQP2 protein abundance in renal cortex and medulla. However, PRSG either alone or in combination with Li did not have a significant effect on the protein abundances of NKCC2 or NCC in the cortex and/or medulla. Immunofluorescence microscopy revealed that PRSG administration prevented Li-induced alterations in cellular disposition of AQP2 protein in medullary collecting ducts. Serum Li, Na, and osmolality were not affected by the administration of PRSG. Similar to CLPD, PRSG administration had no effect on Li-induced increase in urinary Na excretion. However, unlike CLPD, PRSG did not augment Li-induced increase in urinary arginine vasopressin (AVP) excretion. Taken together, these data suggest that the pharmacological inhibition of P2Y 12 -R by the thienopyridine group of drugs may potentially offer therapeutic benefits in Li-induced NDI.

Hypoglycemic and hypolipidemic effects of Lactobacillus fermentum, fruit extracts of Syzygium cumini and Momordica charantia on diabetes induced mice.

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Yousaf, Sehar; Hussain, Abid; Rehman, Shafiqur; Aslam, Muhammad Shahbaz; Abbas, Zaigham

2016-09-01

A lot of treatment strategies available for diabetes but its complications are still a medical problem around the globe. It demands to find out some alternative therapeutic measures. In order to investigate the anti-diabetic potential of probiotics and natural extracts, this study was designed. Accordingly, a local source of yogurt probiotic strain Lactobacillus fermentum was isolated and characterized that showed its probiotic properties. Besides this, natural extracts of plants fruits like java plum (Syzygium cumini) and bitter gourd (M. charantia) were made. Lactobacillus fermentum and the extracts were administered individually as well as in combination to diabetes induced mice. Different parameters like body weight, blood glucose level and lipid profile including total cholesterol, HDL & LDL were analyzed before and after treatment. The results showed that Lactobacillus fermentum and natural extracts have hypoglycemic as well hypolipidemic activity against diabetic mice. This study can further investigated to screen potential compounds from these extracts to control the glucose and the lipid levels in diabetic patients.

Dendrobium officinale Kimura et Migo attenuates diabetic cardiomyopathy through inhibiting oxidative stress, inflammation and fibrosis in streptozotocin-induced mice.

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Zhang, Zhihao; Zhang, Duoduo; Dou, Mengmeng; Li, Zhubo; Zhang, Jie; Zhao, Xiaoyan

2016-12-01

Dendrobium officinale Kimura et Migo (Dendrobium catenatum Lindley), a prized traditional Chinese Medicine, has been used in China and Southeast Asian countries for centuries. The present study was aimed to investigate the effects and the possible mechanisms of the Dendrobium officinale extracts (DOE) on diabetic cardiomyopathy in mice. The diabetic model was induced by intraperitoneal injection of streptozotocin at the dose of 50mg/kg body weight for 5 consecutive days. After 8 weeks treatment of DOE, mice were sacrificed, blood sample and heart tissues were collected. Our results showed that Streptozotocin-induced diabetic model was effectively achieved and serum CK and LDH levels were significantly increased in mice with diabetic cardiomyopathy. Pretreatment with DOE decreased the heart-to-body weight ratio (HW/BW) and showed an evident hypoglycemic effect. DOE pretreatment significantly decreased CK, LDH, TC and TG levels, limited the production of MDA and increased the activities of T-SOD. The histological analysis of Oil red O staining and Sirius red staining showed an obvious amelioration of cardiac injury, inhibition of cardiac lipid accumulation and deposition of collagen when pretreatment with DOE. In addition, Western blot detection and analysis showed that DOE down-regulated the expression of TGF-β, collegan-1, fibronectin, NF-κB, TNF-α and IL-1β. In conclusion, our study suggested that DOE possesses the cardioprotective potential against diabetic cardiomyopathy, which may be due to the inhibition of oxidative stress, cardiac lipid accumulation, pro-inflammatory cytokines and cardiac fibrosis. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Protective Role of Emodin in Reducing The Gamma Rays Induced Hazardous Effects On The Tongue of Diabetic or Normoglycaemic Mice

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Haggag, M.G.; Kazem, H.H.

2013-01-01

Ionizing radiation leads to damage at various cellular and sub-cellular levels and can be prevented by radio protectors. There is a need for natural prospective radio protectors that protect normal tissues from ionizing radiation in patients receiving high doses of radiation for treating malignant neoplasms. The study aimed to evaluate the potential protective role of emodin in reducing the severity of gamma rays-induced hazardous damage in the tongue of normoglycaemic and diabetic mice. Sixty-four male mice were randomly divided into 8 experimental groups: control group received vehicle, emodin group received daily emodin dose of 4g/kg orally for a week, diabetes mellitus (DM) group in which DM was induced by streptozotocin (STZ) treatment, emodin + DM received emodin for a week + STZ treatment, irradiated group submitted to 4 Gy of gamma rays and received vehicle for a week, gamma rays + DM group received gamma rays + STZ treatment, gamma rays + emodin group received gamma rays + emodin for a week, and gamma rays + DM + emodin group received gamma rays + STZ treatment + emodin for a week. Tongue and serum of mice were biochemically examined for screening gamma radiation and diabetic damages and the efficacy of emodin in ameliorating these damaging effects. The levels of cellular thiols such as reduced glutathione (GSH), oxidized glutathione (GSSG), total thiols (TT) and lipid peroxidation products; malondialdehyde (MDA) and conjugated dienes (CD), were assessed in tongue tissues. Tongue antioxidant enzymes; gamma glutamyl transferase (GGT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glucose-6-phosphatase (G-6-P), were measured and serum glucose level was estimated. The results revealed alterations of the levels of cellular thiols and antioxidant enzymes in tongue and the level of glucose in serum of gamma irradiated diabetic mice were ameliorated in mice groups received emodin treatment. The results suggest that emodin treatment (4 g

Effect of aqueous and alcoholic extract of Sesbania sesban (Linn Merr. root on glycemic control in streptozotocin-induced diabetic mice

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Manjusha Choudhary

2014-01-01

Full Text Available Aim: The present study was carried out to investigate the hypoglycemic effects of the aqueous and ethanolic extracts of Sesbania sesban (SS (Merr. roots, which is widely used in inflammation, fever, ulcers, leucoderma and diabetes in various parts of India. Materials and Methods: SS extracts were administered orally at doses (500 and 1000 mg/kg to normal and streptozotocin (STZ induced Type-2 diabetic mice. The fasting blood glucose (FBG, biochemical parameters in serum viz., blood glucose, serum insulin, cholesterol, triglyceride (TG, high-density lipoprotein (HDL cholesterol, urea, creatinine and total protein, change in body weight, internal organs weight, food intake, water intake and glycogen level in liver were performed for the evaluation of hypoglycemic effects. Results: Both doses of aqueous and ethanolic SS extracts caused a marked decrease of FBG in STZ induced Type-2 diabetic mice. Both extracts decreased the cholesterol, TG, urea, creatinine level and increased the insulin, HDL cholesterol and total protein level. Decrease in body weight and glycogen level induced by STZ was restored. Increase in water and food intake induced by STZ was decreased. Conclusions: The results suggest that aqueous and ethanolic extracts of SS may have hypoglycemic potential for the Type-2 diabetes and support the traditional use of the roots of plant as a hypoglycemic agent.

Preventive effects of andrographolide on the development of diabetes in autoimmune diabetic NOD mice by inducing immune tolerance.

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Zhang, Chengliang; Gui, Ling; Xu, Yanjiao; Wu, Tao; Liu, Dong

2013-08-01

Andrographolide, an active component in traditional anti-diabetic herbal plants, is a diterpenoid lactone isolated from Andrographis paniculata because of its potent anti-inflammatory and hypoglycemic effects. However, the effect of andrographolide on the development of diabetes in autoimmune non-obese diabetic (NOD) mice remains unknown. This study aimed to investigate the protective effects of andrographolide on the development of autoimmune diabetes and clarify the underlying mechanism. NOD mice were randomly divided into four groups and administered with water and andrographolide at 50, 100, and 150mg/kg body weight for four weeks. ICR mice were also selected as the control group. Oral glucose tolerance and histopathological insulitis were examined. Th1/Th2/Th17 cytokine secretion was determined by ELISA. The transcriptional profiles of T-bet, GATA3, and RORγt in the pancreatic lymphatic node samples derived from the NOD mice were detected by RT-PCR. After four weeks of oral supplementation, andrographolide significantly inhibited insulitis, delayed the onset, and suppressed the development of diabetes in 30-week-old NOD mice in a dose dependent manner. This protective status was correlated with a substantially decreased production of interferon (IFN)-γ and interleukin (IL)-2, increased IL-10 and transforming growth factor (TGF)-β, and a reduced IL-17. Andrographolide also increased GATA3 mRNA expression but decreased T-bet and RORγt mRNA expressions. Our results suggested that andrographolide prevented type 1 diabetes by maintaining Th1/Th2/Th17 homeostasis. Copyright © 2013 Elsevier B.V. All rights reserved.

Early-Onset Diabetic E1-DN Mice Develop Albuminuria and Glomerular Injury Typical of Diabetic Nephropathy

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Mervi E. Hyvönen

2015-01-01

Full Text Available The transgenic E1-DN mice express a kinase-negative epidermal growth factor receptor in their pancreatic islets and are diabetic from two weeks of age due to impaired postnatal growth of β-cell mass. Here, we characterize the development of hyperglycaemia-induced renal injury in the E1-DN mice. Homozygous mice showed increased albumin excretion rate (AER at the age of 10 weeks; the albuminuria increased over time and correlated with blood glucose. Morphometric analysis of PAS-stained histological sections and electron microscopy images revealed mesangial expansion in homozygous E1-DN mice, and glomerular sclerosis was observed in the most hyperglycaemic mice. The albuminuric homozygous mice developed also other structural changes in the glomeruli, including thickening of the glomerular basement membrane and widening of podocyte foot processes that are typical for diabetic nephropathy. Increased apoptosis of podocytes was identified as one mechanism contributing to glomerular injury. In addition, nephrin expression was reduced in the podocytes of albuminuric homozygous E1-DN mice. Tubular changes included altered epithelial cell morphology and increased proliferation. In conclusion, hyperglycaemic E1-DN mice develop albuminuria and glomerular and tubular injury typical of human diabetic nephropathy and can serve as a new model to study the mechanisms leading to the development of diabetic nephropathy.

Psoralea corylifolia L. Seed Extract Ameliorates Streptozotocin-Induced Diabetes in Mice by Inhibition of Oxidative Stress

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Eunhui Seo

2014-01-01

Full Text Available Pancreatic beta-cell death is known to be the cause of deficient insulin production in diabetes mellitus. Oxidative stress is one of the major causes of beta-cell death. In this study, we investigated the effects of Psoralea corylifolia L. seed (PCS extract on beta-cell death. Oral administration of PCS extract resulted in a significant improvement of hyperglycemia in streptozotocin-induced diabetic mice. PCS extract treatment improved glucose tolerance and increased serum insulin levels. To study the mechanisms involved, we investigated the effects of PCS extract on H2O2-induced apoptosis in INS-1 cells. Treatment with PCS extract inhibited cell death. PCS extract treatment decreased reactive oxygen species level and activated antioxidative enzymes. Among the major components of PCS extract, psoralen and isopsoralen (coumarins, but not bakuchiol, showed preventive effects against H2O2-induced beta-cell death. These findings indicate that PCS extract may be a potential pharmacological agent to protect against pancreatic beta-cell damage caused by oxidative stress associated with diabetes.

Anti-diabetic effects of Inonotus obliquus polysaccharides-chromium (III) complex in type 2 diabetic mice and its sub-acute toxicity evaluation in normal mice.

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Wang, Cong; Chen, Zhongqin; Pan, Yuxiang; Gao, Xudong; Chen, Haixia

2017-10-01

Polysaccharides are important bioactive ingredients from Inonotus obliquus. This study aimed to synthesize and characterize a novel I. obliquus polysaccharides-chromium (III) complex (UIOPC) and investigate the anti-diabetic effects in streptozotocin (STZ) induced type 2 diabetes mellitus (T2DM) mice and sub-acute toxicity in normal mice. The molecular weight of UIOPC was about 11.5 × 10 4  Da with the chromium content was 13.01% and the chromium was linked with polysaccharides through coordination bond. After treatment of UIOPC for four weeks, the body weight, fasting blood glucose (FBG) levels, plasma insulin levels of the diabetic mice were significantly reduced when compared with those of the diabetic mice (p < 0.05). The results on serum profiles and antioxidant enzymes activities revealed that UIOPC had a positive effect on hypoglycemic and antioxidant ability. Histopathology results showed that UIOPC could effectively alleviate the STZ-lesioned tissues in diabetic mice. Furthermore, high dose administration of UIOPC had no obviously influence on serum profiles levels and antioxidant ability of the normal mice and the organ tissues maintained organized and integrity in the sub-acute toxicity study. These results suggested that UIOPC might be a good candidate for the functional food or pharmaceuticals in the treatment of T2DM. Copyright © 2017 Elsevier Ltd. All rights reserved.

CD40 in Retinal Müller Cells Induces P2X7-Dependent Cytokine Expression in Macrophages/Microglia in Diabetic Mice and Development of Early Experimental Diabetic Retinopathy.

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Portillo, Jose-Andres C; Lopez Corcino, Yalitza; Miao, Yanling; Tang, Jie; Sheibani, Nader; Kern, Timothy S; Dubyak, George R; Subauste, Carlos S

2017-02-01

Müller cells and macrophages/microglia are likely important for the development of diabetic retinopathy; however, the interplay between these cells in this disease is not well understood. An inflammatory process is linked to the onset of experimental diabetic retinopathy. CD40 deficiency impairs this process and prevents diabetic retinopathy. Using mice with CD40 expression restricted to Müller cells, we identified a mechanism by which Müller cells trigger proinflammatory cytokine expression in myeloid cells. During diabetes, mice with CD40 expressed in Müller cells upregulated retinal tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β), intracellular adhesion molecule 1 (ICAM-1), and nitric oxide synthase (NOS2), developed leukostasis and capillary degeneration. However, CD40 did not cause TNF-α or IL-1β secretion in Müller cells. TNF-α was not detected in Müller cells from diabetic mice with CD40 + Müller cells. Rather, TNF-α was upregulated in macrophages/microglia. CD40 ligation in Müller cells triggered phospholipase C-dependent ATP release that caused P2X 7 -dependent production of TNF-α and IL-1β by macrophages. P2X 7 -/- mice and mice treated with a P2X 7 inhibitor were protected from diabetes-induced TNF-α, IL-1β, ICAM-1, and NOS2 upregulation. Our studies indicate that CD40 in Müller cells is sufficient to upregulate retinal inflammatory markers and appears to promote experimental diabetic retinopathy and that Müller cells orchestrate inflammatory responses in myeloid cells through a CD40-ATP-P2X 7 pathway. © 2017 by the American Diabetes Association.

Mesenchymal Stem Cell-Like Cells Derived from Mouse Induced Pluripotent Stem Cells Ameliorate Diabetic Polyneuropathy in Mice

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Tatsuhito Himeno

2013-01-01

Full Text Available Background. Although pathological involvements of diabetic polyneuropathy (DPN have been reported, no dependable treatment of DPN has been achieved. Recent studies have shown that mesenchymal stem cells (MSCs ameliorate DPN. Here we demonstrate a differentiation of induced pluripotent stem cells (iPSCs into MSC-like cells and investigate the therapeutic potential of the MSC-like cell transplantation on DPN. Research Design and Methods. For induction into MSC-like cells, GFP-expressing iPSCs were cultured with retinoic acid, followed by adherent culture for 4 months. The MSC-like cells, characterized with flow cytometry and RT-PCR analyses, were transplanted into muscles of streptozotocin-diabetic mice. Three weeks after the transplantation, neurophysiological functions were evaluated. Results. The MSC-like cells expressed MSC markers and angiogenic/neurotrophic factors. The transplanted cells resided in hindlimb muscles and peripheral nerves, and some transplanted cells expressed S100β in the nerves. Impairments of current perception thresholds, nerve conduction velocities, and plantar skin blood flow in the diabetic mice were ameliorated in limbs with the transplanted cells. The capillary number-to-muscle fiber ratios were increased in transplanted hindlimbs of diabetic mice. Conclusions. These results suggest that MSC-like cell transplantation might have therapeutic effects on DPN through secreting angiogenic/neurotrophic factors and differentiation to Schwann cell-like cells.

Akita spontaneously type 1 diabetic mice exhibit elevated vascular arginase and impaired vascular endothelial and nitrergic function.

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Toque, Haroldo A; Nunes, Kenia P; Yao, Lin; Xu, Zhimin; Kondrikov, Dmitry; Su, Yunchao; Webb, R Clinton; Caldwell, Ruth B; Caldwell, R William

2013-01-01

Elevated arginase (Arg) activity is reported to be involved in diabetes-induced vascular endothelial dysfunction. It can reduce L-arginine availability to nitric oxide (NO) synthase (NOS) and NO production. Akita mice, a genetic non-obese type 1 diabetes model, recapitulate human diabetes. We determined the role of Arg in a time-course of diabetes-associated endothelial dysfunction in aorta and corpora cavernosa (CC) from Akita mice. Endothelium-dependent relaxation, Arg and NOS activity, and protein expression levels of Arg and constitutive NOS were assessed in aortas and CC from Akita and non-diabetic wild type (WT) mice at 4, 12 and 24 wks of age. Systolic blood pressure (SBP) was assessed by tail cuff. In aorta and CC, Akita mice exhibited a progressive impairment of vascular endothelial and nitrergic function increased Arg activity and expression (Arg1 in aorta and both Arg1 and Arg2 in CC) compared with that of age-matched WT mice. Treatment of aorta and CC from Akita mice with an Arg inhibitor (BEC or ABH) reduced diabetes-induced elevation of Arg activity and restored endothelial and nitrergic function. Reduced levels of phospho-eNOS at Ser(1177) (in aorta and CC) and nNOS expression (in CC) were observed in Akita mice at 12 and 24 wks. Akita mice also had decreased NOS activity in aorta and CC at 12 and 24 wks that was restored by BEC treatment. Further, Akita mice exhibited moderately increased SBP at 24 wks and increased sensitivity to PE-induced contractions in aorta and sympathetic nerve stimulation in CC at 12 and 24 wks. Over 24 wks of diabetes in Akita mice, both aortic and cavernosal tissues exhibited increased Arg activity/expression, contributing to impaired endothelial and nitrergic function and reduced NO production. Our findings demonstrate involvement of Arg activity in diabetes-induced impairment of vascular function in Akita mouse.

Akita spontaneously type 1 diabetic mice exhibit elevated vascular arginase and impaired vascular endothelial and nitrergic function.

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Haroldo A Toque

Full Text Available Elevated arginase (Arg activity is reported to be involved in diabetes-induced vascular endothelial dysfunction. It can reduce L-arginine availability to nitric oxide (NO synthase (NOS and NO production. Akita mice, a genetic non-obese type 1 diabetes model, recapitulate human diabetes. We determined the role of Arg in a time-course of diabetes-associated endothelial dysfunction in aorta and corpora cavernosa (CC from Akita mice.Endothelium-dependent relaxation, Arg and NOS activity, and protein expression levels of Arg and constitutive NOS were assessed in aortas and CC from Akita and non-diabetic wild type (WT mice at 4, 12 and 24 wks of age. Systolic blood pressure (SBP was assessed by tail cuff. In aorta and CC, Akita mice exhibited a progressive impairment of vascular endothelial and nitrergic function increased Arg activity and expression (Arg1 in aorta and both Arg1 and Arg2 in CC compared with that of age-matched WT mice. Treatment of aorta and CC from Akita mice with an Arg inhibitor (BEC or ABH reduced diabetes-induced elevation of Arg activity and restored endothelial and nitrergic function. Reduced levels of phospho-eNOS at Ser(1177 (in aorta and CC and nNOS expression (in CC were observed in Akita mice at 12 and 24 wks. Akita mice also had decreased NOS activity in aorta and CC at 12 and 24 wks that was restored by BEC treatment. Further, Akita mice exhibited moderately increased SBP at 24 wks and increased sensitivity to PE-induced contractions in aorta and sympathetic nerve stimulation in CC at 12 and 24 wks.Over 24 wks of diabetes in Akita mice, both aortic and cavernosal tissues exhibited increased Arg activity/expression, contributing to impaired endothelial and nitrergic function and reduced NO production. Our findings demonstrate involvement of Arg activity in diabetes-induced impairment of vascular function in Akita mouse.

Chronic Inhibition of PDE5 Limits Pro-Inflammatory Monocyte-Macrophage Polarization in Streptozotocin-Induced Diabetic Mice.

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Mary Anna Venneri

Full Text Available Diabetes mellitus is characterized by changes in endothelial cells that alter monocyte recruitment, increase classic (M1-type tissue macrophage infiltration and lead to self-sustained inflammation. Our and other groups recently showed that chronic inhibition of phosphodiesterase-5 (PDE5i affects circulating cytokine levels in patients with diabetes; whether PDE5i also affects circulating monocytes and tissue inflammatory cell infiltration remains to be established. Using murine streptozotocin (STZ-induced diabetes and in human vitro cell-cell adhesion models we show that chronic hyperglycemia induces changes in myeloid and endothelial cells that alter monocyte recruitment and lead to self-sustained inflammation. Continuous PDE5i with sildenafil (SILD expanded tissue anti-inflammatory TIE2-expressing monocytes (TEMs, which are known to limit inflammation and promote tissue repair. Specifically, SILD: 1 normalizes the frequency of circulating pro-inflammatory monocytes triggered by hyperglycemia (53.7 ± 7.9% of CD11b+Gr-1+ cells in STZ vs. 30.4 ± 8.3% in STZ+SILD and 27.1 ± 1.6% in CTRL, P<0.01; 2 prevents STZ-induced tissue inflammatory infiltration (4-fold increase in F4/80+ macrophages in diabetic vs. control mice by increasing renal and heart anti-inflammatory TEMs (30.9 ± 3.6% in STZ+SILD vs. 6.9 ± 2.7% in STZ, P <0.01, and 11.6 ± 2.9% in CTRL mice; 3 reduces vascular inflammatory proteins (iNOS, COX2, VCAM-1 promoting tissue protection; 4 lowers monocyte adhesion to human endothelial cells in vitro through the TIE2 receptor. All these changes occurred independently from changes of glycemic status. In summary, we demonstrate that circulating renal and cardiac TEMs are defective in chronic hyperglycemia and that SILD normalizes their levels by facilitating the shift from classic (M1-like to alternative (M2-like/TEM macrophage polarization. Restoration of tissue TEMs with PDE5i could represent an additional pharmacological tool to prevent

Softened food reduces weight loss in the streptozotocin-induced male mouse model of diabetic nephropathy.

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Nørgaard, Sisse A; Sand, Fredrik W; Sørensen, Dorte B; Abelson, Klas Sp; Søndergaard, Henrik

2018-01-01

The streptozotocin (STZ)-induced diabetic mouse is a widely used model of diabetes and diabetic nephropathy (DN). However, it is a well-known issue that this model is challenged by high weight loss, which despite supportive measures often results in high euthanization rates. To overcome these issues, we hypothesized that supplementing STZ-induced diabetic mice with water-softened chow in addition to normal chow would reduce weight loss, lower the need for supportive treatment, and reduce the number of mice reaching the humane endpoint of 20% weight loss. In a 15 week STZ-induced DN study we demonstrated that diabetic male mice receiving softened chow had reduced acute weight loss following STZ treatment ( p = 0.045) and additionally fewer mice were euthanized due to weight loss. By supplementing the diabetic mice with softened chow, no mice reached 20% weight loss whereas 37.5% of the mice without this supplement reached this humane endpoint ( p = 0.0027). Excretion of corticosterone metabolites in faeces was reduced in diabetic mice on softened chow ( p = 0.0007), suggesting lower levels of general stress. Finally, it was demonstrated that the water-softened chow supplement did not significantly affect the induction of key disease parameters, i.e. %HbA1C and albuminuria nor result in abnormal teeth wear. In conclusion, supplementation of softened food is refining the STZ-induced diabetic mouse model significantly by reducing stress, weight loss and the number of animals sacrificed due to humane endpoints, while maintaining the key phenotypes of diabetes and nephropathy.

Oligonol, a low-molecular-weight polyphenol derived from lychee fruit, attenuates diabetes-induced renal damage through the advanced glycation end product-related pathway in db/db mice.

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Park, Chan Hum; Yokozawa, Takako; Noh, Jeong Sook

2014-08-01

This study was conducted to examine whether oligonol, a low-molecular-weight polyphenol derived from lychee fruit, has an ameliorative effect on diabetes-induced alterations, such as advanced glycation end product (AGE) formation or apoptosis in the kidneys of db/db mice with type 2 diabetes. Oligonol [10 or 20 mg/(kg body weight · d), orally] was administered every day for 8 wk to prediabetic db/db mice, and its effect was compared with vehicle-treated db/db and normal control mice (m/m). The administration of oligonol decreased the elevated renal glucose concentrations and reactive oxygen species in db/db mice (P factor-α (P related variables, representing renoprotective effects against the development of diabetic complications in db/db mice with type 2 diabetes. © 2014 American Society for Nutrition.

Effects of dietary supplementation with docosahexaenoic acid (DHA on hippocampal gene expression in streptozotocin induced diabetic C57Bl/6 mice

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Jency Thomas

2015-08-01

Full Text Available A body of evidence has accumulated indicating diabetes is associated with cognitive impairments. Effective strategies are therefore needed that will delay or prevent the onset of these diabetes-related deficits. In this regard, dietary modification with the naturally occurring compound, docosahexaenoic acid (DHA, holds significant promise as it has been shown to have anti-inflammatory, anti-oxidant, and anti-apoptotic properties. The hippocampus, a limbic structure involved in cognitive functions such as memory formation, is particularly vulnerable to the neurotoxic effects related to diabetes, and we have previously shown that streptozotocin-induced diabetes alters hippocampal gene expression, including genes involved in synaptic plasticity and neurogenesis. In the present study, we explored the effects of dietary supplementation with DHA on hippocampal gene expression in C57Bl/6 diabetic mice. Diabetes was established using streptozotocin (STZ and once stable, the dietary intervention group received AIN93G diet supplemented with DHA (50 mg/kg/day for 6 weeks. Microarray based genome-wide expression analysis was carried out on the hippocampus of DHA supplemented diabetic mice and confirmed by real time polymerase chain reaction (RT-qPCR. Genome-wide analysis identified 353 differentially expressed genes compared to non-supplemented diabetic mice. For example, six weeks of dietary DHA supplementation resulted in increased hippocampal expression of Igf II and Sirt1 and decreased expression of Tnf-α, Il6, Mapkapk2 and ApoE, compared to non-supplemented diabetic mice. Overall, DHA supplementation appears to alter hippocampal gene expression in a way that is consistent with it being neuroprotective in the context of the metabolic and inflammatory insults associated with diabetes.

Effect of visfatin on lipid profile of obese and diabetic mice

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Naz, R.; Hussain, M.M.; Aslam, M.

2012-01-01

Objective: To determine the effect of visfatin on blood lipid levels in balb/c strain of albino mice. Design: Quasi experimental study. Place and duration of study: The study was carried out at the department of Physiology, Army Medical College, Rawalpindi and National Institute of Health Sciences, Islamabad from April to December 2007. Material and Methods: One hundred and twenty balb/c strain albino mice were procured from NIH, Islamabad. After taking base line blood samples, mice were divided randomly into four groups. Animals in groups I and II were made obese by feeding high fat / high carbohydrate diet whereas mice in Groups III and IV were induced diabetes mellitus by injecting streptozotocin. Groups I (obese) and III (diabetic) served as controls whereas groups II (obese treated) and IV (diabetic treated) were administered visfatin injection. Terminal intracardiac blood sample was used to measure the serum lipid and visfatin levels. Results: Serum lipid levels were found increased in obese and diabetic groups as compared to healthy mice. The administration of recombinant-histidine soluble (mice) visfatin significantly (p< 0.01) decreased the serum lipid levels with concomitant increase in HDL levels (p< 0.01) in obese and diabetic groups of mice and were comparable with baseline normal values of healthy controls. Conclusion: Visfatin is a potential antilipidemic adipocytokine that probably modulates insulin sensitivity and decreases atherogenic lipids (triglycerides, cholesterol, LDL and VLDL) with concomitant increase in HDL in obesity and diabetes mellitus. (author)

Inhibition of nuclear factor of activated T-cells (NFAT suppresses accelerated atherosclerosis in diabetic mice.

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Anna V Zetterqvist

Full Text Available OBJECTIVE OF THE STUDY: Diabetic patients have a much more widespread and aggressive form of atherosclerosis and therefore, higher risk for myocardial infarction, peripheral vascular disease and stroke, but the molecular mechanisms leading to accelerated damage are still unclear. Recently, we showed that hyperglycemia activates the transcription factor NFAT in the arterial wall, inducing the expression of the pro-atherosclerotic protein osteopontin. Here we investigate whether NFAT activation may be a link between diabetes and atherogenesis. METHODOLOGY AND PRINCIPAL FINDINGS: Streptozotocin (STZ-induced diabetes in apolipoprotein E(-/- mice resulted in 2.2 fold increased aortic atherosclerosis and enhanced pro-inflammatory burden, as evidenced by elevated blood monocytes, endothelial activation- and inflammatory markers in aorta, and pro-inflammatory cytokines in plasma. In vivo treatment with the NFAT blocker A-285222 for 4 weeks completely inhibited the diabetes-induced aggravation of atherosclerosis, having no effect in non-diabetic mice. STZ-treated mice exhibited hyperglycemia and higher plasma cholesterol and triglycerides, but these were unaffected by A-285222. NFAT-dependent transcriptional activity was examined in aorta, spleen, thymus, brain, heart, liver and kidney, but only augmented in the aorta of diabetic mice. A-285222 completely blocked this diabetes-driven NFAT activation, but had no impact on the other organs or on splenocyte proliferation or cytokine secretion, ruling out systemic immunosuppression as the mechanism behind reduced atherosclerosis. Instead, NFAT inhibition effectively reduced IL-6, osteopontin, monocyte chemotactic protein 1, intercellular adhesion molecule 1, CD68 and tissue factor expression in the arterial wall and lowered plasma IL-6 in diabetic mice. CONCLUSIONS: Targeting NFAT signaling may be a novel and attractive approach for the treatment of diabetic macrovascular complications.

Podocyte-specific deletion of Rac1 leads to aggravation of renal injury in STZ-induced diabetic mice

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Ishizaka, Masanori; Gohda, Tomohito; Takagi, Miyuki; Omote, Keisuke; Sonoda, Yuji; Oliva Trejo, Juan Alejandro; Asao, Rin; Hidaka, Teruo; Asanuma, Katsuhiko; Horikoshi, Satoshi; Tomino, Yasuhiko

2015-01-01

Rac1, a GTPase of the Rho subfamily, has a crucial role in cytoskeletal architecture, as well as the regulation of cell migration and growth. However, renal injury in mice with podocyte-specific deletion of Rac1 has yet to be elucidated fully due to conflicting findings. Herein, we identified a possible role for Rac1 in podocytes of streptozotocin- (STZ) induced diabetic mice. The urinary albumin/creatinine ratio (ACR) in the knockout (KO) group was significantly higher than that in the wild type (WT) group at any week of age. A more marked ACR increase was observed in STZ/KO group than STZ/WT group, although ACR did increase with weeks of age in both diabetic groups. The kidney sections from diabetic mice revealed a glomerular hypertrophy with mesangial expansion, but there was no appreciable difference in glomerular findings under a light microscope between STZ/WT and STZ/KO mice. However, an electron microscopy analysis revealed that regardless of the presence or absence of diabetes, both KO (KO and STZ/KO) groups had a higher rate of foot process effacement compared with both WT (WT and STZ/WT) groups. The expression levels of the slit diaphragm protein, podocin, was reduced with the induction of diabetes, and the levels in the STZ/KO group experienced a further reduction compared with the STZ/WT group. The number of WT1-positive cells in the STZ/KO group was more significantly decreased than that in the other three groups. In contrast, the numbers of cleaved caspase 3- and TUNEL-positive cells in the glomeruli of the STZ/KO group were more increased than those in the STZ/WT group. Thus, this study provides evidence that podocyte-specific deletion of Rac1 results in morphological alteration in podocytes, and that the induction of apoptosis or decreased expression of the slit diaphragm proteins by hyperglycemic stimuli are associated with the progression of diabetic nephropathy.

Podocyte-specific deletion of Rac1 leads to aggravation of renal injury in STZ-induced diabetic mice

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Ishizaka, Masanori [Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Gohda, Tomohito, E-mail: goda@juntendo.ac.jp [Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Takagi, Miyuki; Omote, Keisuke; Sonoda, Yuji [Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Oliva Trejo, Juan Alejandro [Laboratory for Kidney Research (TMK Project), Medical Innovation Center, Kyoto University Graduate School of Medicine, 53 Shogoin Kawaharacho, Sakyo-ku, Kyoto 606-8397 (Japan); Asao, Rin; Hidaka, Teruo [Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Asanuma, Katsuhiko [Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Laboratory for Kidney Research (TMK Project), Medical Innovation Center, Kyoto University Graduate School of Medicine, 53 Shogoin Kawaharacho, Sakyo-ku, Kyoto 606-8397 (Japan); Horikoshi, Satoshi [Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Tomino, Yasuhiko [Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Medical Corporation SHOWAKAI, 3-12-12 Nishishinjuku, Shinjuku-ku, Tokyo 160-0023 (Japan)

2015-11-20

Rac1, a GTPase of the Rho subfamily, has a crucial role in cytoskeletal architecture, as well as the regulation of cell migration and growth. However, renal injury in mice with podocyte-specific deletion of Rac1 has yet to be elucidated fully due to conflicting findings. Herein, we identified a possible role for Rac1 in podocytes of streptozotocin- (STZ) induced diabetic mice. The urinary albumin/creatinine ratio (ACR) in the knockout (KO) group was significantly higher than that in the wild type (WT) group at any week of age. A more marked ACR increase was observed in STZ/KO group than STZ/WT group, although ACR did increase with weeks of age in both diabetic groups. The kidney sections from diabetic mice revealed a glomerular hypertrophy with mesangial expansion, but there was no appreciable difference in glomerular findings under a light microscope between STZ/WT and STZ/KO mice. However, an electron microscopy analysis revealed that regardless of the presence or absence of diabetes, both KO (KO and STZ/KO) groups had a higher rate of foot process effacement compared with both WT (WT and STZ/WT) groups. The expression levels of the slit diaphragm protein, podocin, was reduced with the induction of diabetes, and the levels in the STZ/KO group experienced a further reduction compared with the STZ/WT group. The number of WT1-positive cells in the STZ/KO group was more significantly decreased than that in the other three groups. In contrast, the numbers of cleaved caspase 3- and TUNEL-positive cells in the glomeruli of the STZ/KO group were more increased than those in the STZ/WT group. Thus, this study provides evidence that podocyte-specific deletion of Rac1 results in morphological alteration in podocytes, and that the induction of apoptosis or decreased expression of the slit diaphragm proteins by hyperglycemic stimuli are associated with the progression of diabetic nephropathy.

The Protective Effects of Oral Low-dose Quercetin on Diabetic Nephropathy in Hypercholesterolemic Mice

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Isabele Beserra Santos Gomes

2015-09-01

Full Text Available Aims: Diabetic nephropathy (DN is one of the major causes of end-stage renal disease, and the incidence of DN is increasing worldwide. Considering our previous report indicating that chronic treatment with oral low-dose quercetin (10 mg/Kg demonstrated renoprotective, anti-oxidative and anti-apoptotic effects in the C57BL/6J model of diabetic nephropathy, we investigated whether this flavonoid could also have beneficial effects in concurrent DN and spontaneous atherosclerosis using the apolipoprotein E-deficient mouse (apoE-/-. Methods: DN was induced by streptozotocin (100 mg/kg/day, for 3 days in adult apoE-/-mice. Six weeks later, the mice were divided into the following groups: diabetic apoE-/- mice treated with quercetin (DQ, 10 mg/kg/day, 4 weeks, diabetic ApoE-/- mice treated with vehicle (DV and non-treated non-diabetic (ND mice.Results: Quercetin treatment caused a reduction in polyuria (~30%, glycemia (~25%, abolished the hypertriglyceridemia and had significant effects on renal function, including decreased proteinuria (~15% and creatininemia (~30%, which were accompanied by beneficial effects on the renal structural changes, including normalization of the index of glomerulosclerosis and kidney weight.Conclusions: Our data revealed that quercetin treatment significantly reduced DN in hypercholesterolemic mice by inducing biochemical and morphological modifications. Thus, this translational study highlights the importance of quercetin as a potential nutraceutical for the management of DN, including in diabetes associated with dyslipidemia.

Mitochondrial dysfunction and apoptosis in cumulus cells of type I diabetic mice.

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Qiang Wang

2010-12-01

Full Text Available Impaired oocyte quality has been demonstrated in diabetic mice; however, the potential pathways by which maternal diabetes exerts its effects on the oocyte are poorly understood. Cumulus cells are in direct contact with the oocyte via gap junctions and provide essential nutrients to support oocyte development. In this study, we investigated the effects of maternal diabetes on the mitochondrial status in cumulus cells. We found an increased frequency of fragmented mitochondria, a decreased transmembrane potential and an aggregated distribution of mitochondria in cumulus cells from diabetic mice. Furthermore, while mitochondrial biogenesis in cumulus cells was induced by maternal diabetes, their metabolic function was disrupted as evidenced by lower ATP and citrate levels. Moreover, we present evidence suggesting that the mitochondrial impairments induced by maternal diabetes, at least in part, lead to cumulus cell apoptosis through the release of cytochrome c. Together the deleterious effects on cumulus cells may disrupt trophic and signaling interactions with the oocyte, contributing to oocyte incompetence and thus poor pregnancy outcomes in diabetic females.

Antihyperglycemic effect of Sesbania grandiflora seed decoction on streptozotocin-induced diabetic mice: Inflammatory status and the role of interleukin-10

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Zamroni, Ahmad; Widjanarko, Simon B.; Rifa'i, Muhaimin; Zubaidah, Elok

2017-05-01

Diabetes is one of the fastest growing diseases in the world: its prevalence is estimated to reach 642 million people, or one-tenth of adults will have diabetes by 2040. Traditional herbal exploration and investigation are needed in order to discover medicines that have potential anti-diabetic activity, with no or lower side effects than the medicines clinically used today. In this research, we investigated the anti-hyperglycemic activity of an aqueous decoction of Sesbania grandiflora seeds in streptozotocin-induced diabetic mice, and analyzed the immune responses that occurred during the counter balance process to reach blood glucose homeostasis. Our results revealed that administration of the aqueous decoction (2.5 g/kg BW) could lower the blood glucose levels of diabetic mice from an initial blood glucose level of 435 mg/dl to 213 mg/dl within 18 days of treatment. Analysis of inflammatory markers showed that there was no significant difference in the relative amounts of CD4+CD62L-, CD8+CD62L-, TNF-α or IFN-γ between the experimental groups, which revealed that there were no pro-inflammatory responses involved either in hyperglycemia or in the blood glucose lowering process. On the other hand, an increased amount of interleukin-10 in diabetic mice treated with an S. grandiflora seed decoction indicated a role for IL-10 in maintaining blood glucose homeostasis.

Sodium fusidate ameliorates the course of diabetes induced in mice by multiple low doses of streptozotocin

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Nicoletti, F; Di Marco, R; Conget, I

2000-01-01

We studied the effects of the immunosuppressant sodium fusidate (fusidin) on murine immunoinflammatory diabetes mellitus (DM) induced by multiple low doses of streptozotocin (SZ). Fusidin was given by gavage to three strains of mice (C57KsJ, C57BL/6, CD1) at doses 10 or 100 mg/kg body weight every...... induced in vivo by ConA, reducing the levels of IFN-gamma, IL-2 and TNF-alpha and augmenting the level of IL-6. However, only the inhibitory effect of the drug on the synthesis/release of IFN-gamma seemed to be causally related to its capacity to counteract the SZ-induced DM. In fact, the disease...... other day. The drug was administered as an early or late prophylactic regime starting either 1 day prior to the first or after the fifth and last injection of SZ. In both situations the largest dose of fusidin successfully reduced the clinical, chemical and histological signs of DM, the treated mice...

Taenia crassiceps Infection Attenuates Multiple Low-Dose Streptozotocin-Induced Diabetes

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Arlett Espinoza-Jiménez

2010-01-01

Full Text Available Taenia crassiceps, like other helminths, can exert regulatory effects on the immune system of its host. This study investigates the effect of chronic T. crassiceps infection on the outcome of Multiple Low Dose Streptozotocin-Induced Diabetes (MLDS. Healthy or previously T. crassiceps-infected mice received MLDS and type 1 diabetes (T1D symptoms were evaluated for 6 weeks following the induction of MLDS. T. crassiceps-infected mice displayed lower blood glucose levels throughout the study. A significantly lower percentage of T. crassiceps-infected mice (40% developed T1D compared to the uninfected group (100%. Insulitis was remarkably absent in T. crassiceps-infected mice, which had normal pancreatic insulin content, whereas uninfected mice showed a dramatic reduction in pancreatic insulin. Infected mice that received MLDS did not show an increase in their regulatory T cell population, however, they had a greater number of alternatively activated macrophages, higher levels of the cytokine IL-4, and lower levels of TNF-α. Therefore, infection with T. crassiceps causes an immunomodulation that modifies the incidence and development of MLDS-induced autoimmune diabetes.

Adipose Tissue-Derived Mesenchymal Stem Cells Exert In Vitro Immunomodulatory and Beta Cell Protective Functions in Streptozotocin-Induced Diabetic Mice Model

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Hossein Rahavi

2015-01-01

Full Text Available Regenerative and immunomodulatory properties of mesenchymal stem cells (MSCs might be applied for type 1 diabetes mellitus (T1DM treatment. Thus, we proposed in vitro assessment of adipose tissue-derived MSCs (AT-MSCs immunomodulation on autoimmune response along with beta cell protection in streptozotocin- (STZ- induced diabetic C57BL/6 mice model. MSCs were extracted from abdominal adipose tissue of normal mice and cultured to proliferate. Diabetic mice were prepared by administration of multiple low-doses of streptozotocin. Pancreatic islets were isolated from normal mice and splenocytes prepared from normal and diabetic mice. Proliferation, cytokine production, and insulin secretion assays were performed in coculture experiments. AT-MSCs inhibited splenocytes proliferative response to specific (islet lysate and nonspecific (PHA triggers in a dose-dependent manner (P<0.05. Decreased production of proinflammatory cytokines, such as IFN-γ, IL-2, and IL-17, and increased secretion of regulatory cytokines such as TGF-β, IL-4, IL-10, and IL-13 by stimulated splenocytes were also shown in response to islet lysate or PHA stimulants (P<0.05. Finally, we demonstrated that AT-MSCs could effectively sustain viability as well as insulin secretion potential of pancreatic islets in the presence of reactive splenocytes (P<0.05. In conclusion, it seems that MSCs may provide a new horizon for T1DM cell therapy and islet transplantation in the future.

Effect of the Total Extract of Averrhoacarambola (Oxalidaceae Root on the Expression Levels of TLR4 and NF-κB in Streptozotocin-Induced Diabetic Mice

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Xiaohui Xu

2015-07-01

Full Text Available Background: Averrhoacarambola L., which is a folk medicine used in diabetes mellitus (DM in ancient China, has been reported to have anti-diabetic efficacy. Aims: The aim of this study was to evaluate the hypoglycemic effect of the extract of Averrhoacarambola L. root (EACR on the regulation of the Toll-like receptor 4 (TLR4-Nuclear-factor kappa B (NF-κB pathway in B pathway in streptozotocin (STZ-induced diabetic mice. Methods: the mice were injected with STZ (120 mg/kg body weight via a tail vein. After 72 h, the mice with FBG = 11.1 mmol/L were confirmed as having diabetes. Subsequently, the mice were treated intragastrically with EACR (300, 600, 1200 mg/kg body weight/d and metformin (320 mg/kg body weight/d for 14 days. Results: As a result the serum fasting blood glucose (FBG, interleukin-6 (IL-6 and tumor necrosis factor-a (TNF-a levels were decreased following EACR administration. Immunohistochemical analysis revealed that the pancreatic tissue expression levels of TLR4 and NF-κB were downregulated after EACR administration. EACR suppressed pancreatic mRNA expression level of TLR4 and blocked the downstream NF-κB pathway in the pancreas. According to Western blot analysis EACR suppressed pancreatic TLR4 and NF-κB protein expression levels. Histopathological examination of the pancreas showed that STZ-induced pancreas lesions were alleviated by the EACR treatment. Conclusion: These findings suggest that the modulation of the IL-6 and TNF-a inflammatory cytokines and the suppression of the TLR4-NF-κB pathway are most likely involved in the anti-hyperglycemic effect of EACR in STZ-induced diabetic mice.

Portulaca oleracea Ameliorates Diabetic Vascular Inflammation and Endothelial Dysfunction in db/db Mice

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Lee, An Sook; Lee, Yun Jung; Lee, So Min; Yoon, Jung Joo; Kim, Jin Sook; Kang, Dae Gill; Lee, Ho Sub

2012-01-01

Type 2 diabetes is associated with significantly accelerated rates of micro- and macrovascular complications such as diabetic vascular inflammation and endothelial dysfunction. In the present study, we investigated the protective effect of the aqueous extract of Portulaca oleracea L. (AP), an edible plant used as a folk medicine, on diabetic vascular complications. The db/db mice were treated with AP (300 mg/kg/day, p.o.) for 10 weeks, and AP treatment markedly lowered blood glucose, plasma triglyceride, plasma level of LDL-cholesterol, and systolic blood pressure in diabetic db/db mice. Furthermore, AP significantly increased plasma level of HDL-cholesterol and insulin level. The impairment of ACh- and SNP-induced vascular relaxation of aortic rings were ameliorated by AP treatment in diabetic db/db mice. This study also showed that overexpression of VCAM-1, ICAM-1, E-selectin, MMP-2, and ET-1 were observed in aortic tissues of untreated db/db mice, which were significantly suppressed by treatment with AP. We also found that the insulin immunoreactivity of the pancreatic islets remarkably increased in AP treated db/db mice compared with untreated db/db mice. Taken together, AP suppresses hyperglycemia and diabetic vascular inflammation, and prevents the development of diabetic endothelial dysfunction for the development of diabetes and its vascular complications. PMID:22474522

Differential anti-diabetic effects and mechanism of action of charantin-rich extract of Taiwanese Momordica charantia between type 1 and type 2 diabetic mice.

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Wang, Hsien-Yi; Kan, Wei-Chih; Cheng, Tain-Junn; Yu, Sung-Hsun; Chang, Liang-Hao; Chuu, Jiunn-Jye

2014-07-01

Momordica charantia Linn. (Cucurbitaceae), also called bitter melon, has traditionally been used as a natural anti-diabetic agent for anti-hyperglycemic activity in several animal models and clinical trials. We investigated the differences in the anti-diabetic properties and mechanism of action of Taiwanese M. charantia (MC) between type 1 diabetic (T1D) and type 2 diabetic (T2D) mice. To clarify the beneficial effects of MC, we measured non-fasting glucose, oral glucose tolerance, and plasma insulin levels in KK/HIJ mice with high-fat diet-induced diabetes (200 mg/kg/day of charantin-rich extract of MC [CEMC]) and in ICR mice with STZ-induced diabetes. After 8 weeks, all the mice were exsanguinated, and the expression of the insulin-signaling-associated proteins in their tissue was evaluated, in coordination with the protective effects of CEMC against pancreatic β-cell toxicity (in vitro). Eight weeks of data indicated that CEMC caused a significant decline in non-fasting blood glucose, plasma glucose intolerance, and insulin resistance in the KK/HIJ mice, but not in the ICR mice. Furthermore, CEMC decreased plasma insulin and promoted the sensitivity of insulin by increasing the expression of GLUT4 in the skeletal muscle and of IRS-1 in the liver of KK/HIJ mice; however, CEMC extract had no effect on the insulin sensitivity of ICR mice. In vitro study showed that CEMC prevented pancreatic β cells from high-glucose-induced cytotoxicity after 24 h of incubation, but the protective effect was not detectable after 72 h. Collectively, the hypoglycemic effects of CEMC suggest that it has potential for increasing insulin sensitivity in patients with T2D rather than for protecting patients with T1D against β-cell dysfunction. Copyright © 2014 Elsevier Ltd. All rights reserved.

Treated of type 1 diabetes mellitus in non-obese diabetic mice by transplantation of allogeneic bone marrow and pancreatic tissue

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Yasumizu, R.; Sugiura, K.; Iwai, H.

1987-01-01

Non-obese diabetic (NOD) mice provide a model for type 1 diabetes mellitus. We previously showed that allogeneic bone marrow transplantation (ABMT) can prevent and treat insulitis and overt diabetes in NOD mice. However, ABMT alone could not be used to treat overt diabetes in NOD mice whose islets had been completely destroyed. To provide insulin-producing cells, pancreatic tissue from newborn mice was grafted under the renal capsules in combination with ABMT. The aims of concomitant ABMT are as follows. (i) It induces immunological tolerance to the donor-type major histocompatibility complex determinants and permits the host to accept subsequent pancreatic allografts from the bone marrow donor. (ii) ABMT replaces abnormal stem cells with normal stem cells. After transplantation of bone marrow plus newborn pancreas, NOD mice showed reduction of the glycosuria and a normal response in the glucose-tolerance test. Immunohistological study revealed the presence of clustered insulin-containing beta cells in the grafted pancreatic transplants. ABMT may become a viable treatment of established type 1 diabetes mellitus in humans

Aktivitas Salep Ekstrak Rimpang Kunyit dalam Proses Persembuhan Luka pada Mencit yang Diinduksi Diabetes (THE ACTIVITY OF TURMERIC EXTRACT OINTMENT IN THE WOUND HEALING PROCESS OF INDUCED DIABETIC MICE

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Wiwin Winarsih

2013-07-01

Full Text Available The aim of this study was to evaluate the effectiveness of ethanol turmeric extract ointment in woundhealing process of streptozotocin-induced diabetic mice. Ethyl acetate and hexane fractions of ethanolturmeric extract were studied for their wound-healing properties in the formulation of ointment. Sixty micewere divided into 4 groups : group I was control (normal control, without treatment; group II was diabeticgroup (diabetic, without treatment; group III was diabetic and treated with ethyl acetate fraction ointment,group IV was diabetic and treated with hexane fraction ointment. The diabetic groups were i.p injectedwith 40mg/kg of streptozotocin and all groups were received incision 2 cm on their back skin. The ointmentsof ethyl acetate and hexane fraction were given topically twice a day. Three mice from each groups werenecropsied at 2nd, 4th, 7th, 14th and 21st days post incision (pi for gross pathological and histopathologicalevaluation of the injured skin. Gross examination revealed that the ethyl acetate and hexane fractionointment groups showed better result on wound-healing process compared to the diabetic group.Microscopically, the ethyl acetate and hexane fraction ointment groups showed faster neovascularizationand reepithelialization compared to the diabetic group. In comparison with the diabetic group, the ethylacetate and hexane fraction ointment groups showed fewer neutrophils infiltration which indicated antiinflammatory activities of ethyl acetate and hexane fractions. Based on the macroscopic and microscopicobservation, the ointments of ethyl acetate and hexane fraction have properties to promote wound healingin diabetic mice.

Sensitization to Gliadin Induces Moderate Enteropathy and Insulitis in Nonobese Diabetic-DQ8 Mice

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Galipeau, Heather J.; Rulli, Nestor E.; Jury, Jennifer; Huang, Xianxi; Araya, Romina; Murray, Joseph A.; David, Chella S.; Chirdo, Fernando G.; McCoy, Kathy D.; Verdu, Elena F.

2012-01-01

Celiac disease (CD) is frequently diagnosed in patients with type 1 diabetes (T1D), and T1D patients can exhibit Abs against tissue transglutaminase, the auto-antigen in CD. Thus, gliadin, the trigger in CD, has been suggested to have a role in T1D pathogenesis. The objective of this study was to investigate whether gliadin contributes to enteropathy and insulitis in NOD-DQ8 mice, an animal model that does not spontaneously develop T1D. Gliadin-sensitized NOD-DQ8 mice developed moderate enteropathy, intraepithelial lymphocytosis, and barrier dysfunction, but not insulitis. Administration of anti-CD25 mAbs before gliadin-sensitization induced partial depletion of CD25+Foxp3+ T cells and led to severe insulitis, but did not exacerbate mucosal dysfunction. CD4+ T cells isolated from pancreatic lymph nodes of mice that developed insulitis showed increased proliferation and proinflammatory cytokines after incubation with gliadin but not with BSA. CD4+ T cells isolated from nonsensitized controls did not response to gliadin or BSA. In conclusion, gliadin sensitization induced moderate enteropathy in NOD-DQ8 mice. However, insulitis development required gliadin-sensitization and partial systemic depletion of CD25+Foxp3+ T cells. This humanized murine model provides a mechanistic link to explain how the mucosal intolerance to a dietary protein can lead to insulitis in the presence of partial regulatory T cell deficiency. PMID:21911598

Endothelial arginine resynthesis contributes to the maintenance of vasomotor function in male diabetic mice

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Chennupati, Ramesh; Meens, Merlijn J P M T; Marion, Vincent

2014-01-01

AIM: Argininosuccinate synthetase (ASS) is essential for recycling L-citrulline, the by-product of NO synthase (NOS), to the NOS substrate L-arginine. Here, we assessed whether disturbed arginine resynthesis modulates endothelium-dependent vasodilatation in normal and diabetic male mice. METHODS...... of endothelial citrulline recycling to arginine did not affect blood pressure and systemic arterial vasomotor responses in healthy mice. EDNO-mediated vasodilatation was significantly more impaired in diabetic Ass-KOTie2 than in control mice demonstrating that endothelial arginine recycling becomes a limiting...... responses were studied in isolated saphenous arteries of 12- and 34-week-old Ass-KOTie2 and control animals. At the age of 10 weeks, diabetes was induced in control and Ass-KOTie2 mice by streptozotocin injections. Vasomotor responses of diabetic animals were studied 10 weeks later. MAP was similar...

Calcium dobesilate prevents the oxidative stress and inflammation induced by diabetes in the retina of db/db mice.

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Bogdanov, Patricia; Solà-Adell, Cristina; Hernández, Cristina; García-Ramírez, Marta; Sampedro, Joel; Simó-Servat, Olga; Valeri, Marta; Pasquali, Christian; Simó, Rafael

2017-10-01

Calcium dobesilate (CaD) is beneficial in early stages of diabetic retinopathy (DR), but its mechanisms of action remains to be elucidated. The aim was to investigate the effect of CaD on proinflammatory cytokines and oxidative stress. db/db mice were randomly assigned to daily oral treatment with CaD (200mg/kg/day) or vehicle for 15days. Biomarkers of oxidative stress (dihydroethidium, malondialdehyde), NF-κB, and proinflammatory cytokines (IL-1β, IL-6, IL-8, TNF-α, MCP-1) were examined in the retina by immunohistochemical analysis. Cultures of human retinal endothelial cells (HRECs) were used for complementary experiments. CaD significantly reduced the biomarkers of oxidative stress in the retina of db/db mice. In addition, CaD prevented the increase of NF-κB, IL-6, IL-8, TNF-α and MCP-1 induced by diabetes. CaD inhibited the activation of NF-kβ induced by IL-1β by preventing IKKB-α phosphorylation in HRECs and reduced the upregulation of IL-6 and IL-18 induced by TNF-α in a dose-dependent manner. Our results suggest that antioxidant and antiinflammatory effects are crucial in accounting for the effectiveness of CaD for treating DR. Copyright © 2017 Elsevier Inc. All rights reserved.

Muscle contractility decrement and correlated morphology during the pathogenesis of streptozotocin-diabetic mice.

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Fahim, M A; el-Sabban, F; Davidson, N

1998-06-01

Peripheral neuropathy of both motor and sensory nerves has been well documented in diabetes mellitus, but the evidence for physiological and correlated morphological changes during the pathogenesis of myopathy is scarce. In the present report, we have chosen the dorsiflexor muscle of adult male mice as a model for studying in situ muscle contraction and neuromuscular ultrastructure during the pathogenesis of streptozotocin-induced diabetes. Thirty mice (30 g bodyweight) were injected once i.p. with streptozotocin solution (200 mg/Kg) to induce experimental diabetes mellitus. Comparative analyses of in situ muscle isometric contractile characteristics were studied (at 1 Hz, 5 Hz and 30 Hz nerve stimulation) in urethane-anesthetized (2 mg/g, i.p.) control and diabetic mice at three time points, 2 weeks, 4 weeks, and 8 weeks postinjection. Synaptic delay was also recorded in diabetic and age-matched control mice. There was a significant increase in synaptic delay in both 4-week and 8-week diabetic mice compared with control mice (8.9 +/- 1.2 msec and 7.6 +/- 0.6 msec, respectively, compared with 6.1 +/- 0.5 msec). At all three stimulation frequencies, diabetes did not affect muscle contractile speed but significantly reduced the twitch tension after 8 weeks, with no changes at 2 weeks or 4 weeks. The recorded single-twitch tension values were 2.6 +/- 0.3 g, 2.1 +/- 0.6 g, 2.2 +/- 0.7 g, and 1.2 +/- 0.1 g for control, 2 weeks, 4 weeks, and 8 weeks, respectively. At 30 Hz, the recorded tension values were 4.6 +/- 1.6 g, 3.1 +/- 1.2 g, 3.1 +/- 1.1 g, and 2.1 +/- 1.0 g for control, 2 weeks, 4 weeks, and 8 weeks, respectively. Ultrastructural changes in neuromuscular junctions were similar to those that have been described in disuse and aging. These changes were observed after 8 weeks and included serve loss of synaptic vesicles, electron-dense bodies, and myelin-like figures as well as degeneration of mitochondria. The results reveal that streptozotocin-induced diabetes

The NADPH organizers NoxO1 and p47phox are both mediators of diabetes-induced vascular dysfunction in mice.

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Rezende, Flávia; Moll, Franziska; Walter, Maria; Helfinger, Valeska; Hahner, Fabian; Janetzko, Patrick; Ringel, Christian; Weigert, Andreas; Fleming, Ingrid; Weissmann, Norbert; Kuenne, Carsten; Looso, Mario; Rieger, Michael A; Nawroth, Peter; Fleming, Thomas; Brandes, Ralf P; Schröder, Katrin

2018-05-01

NADPH oxidases are important sources of reactive oxygen species (ROS). Several Nox homologues are present together in the vascular system but whether they exhibit crosstalk at the activity level is unknown. To address this, vessel function of knockout mice for the cytosolic Nox organizer proteins p47phox, NoxO1 and a p47phox-NoxO1-double knockout were studied under normal condition and during streptozotocin-induced diabetes. In the mouse aorta, mRNA expression for NoxO1 was predominant in smooth muscle and endothelial cells, whereas p47phox was markedly expressed in adventitial cells comprising leukocytes and tissue resident macrophages. Knockout of either NoxO1 or p47phox resulted in lower basal blood pressure. Deletion of any of the two subunits also prevented diabetes-induced vascular dysfunction. mRNA expression analysis by MACE (Massive Analysis of cDNA ends) identified substantial gene expression differences between the mouse lines and in response to diabetes. Deletion of p47phox induced inflammatory activation with increased markers of myeloid cells and cytokine and chemokine induction. In contrast, deletion of NoxO1 resulted in an attenuated interferon gamma signature and reduced expression of genes related to antigen presentation. This aspect was also reflected by a reduced number of circulating lymphocytes in NoxO1-/- mice. ROS production stimulated by NoxO1 and p47phox limit endothelium-dependent relaxation and maintain blood pressure in mice. However, NoxO1 and p47phox cannot substitute each other despite their similar effect on vascular function. Deletion of NoxO1 induced an anti-inflammatory phenotype, whereas p47phox deletion rather elicited a hyper-inflammatory response. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Facial nerve palsy after reactivation of herpes simplex virus type 1 in diabetic mice.

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Esaki, Shinichi; Yamano, Koji; Katsumi, Sachiyo; Minakata, Toshiya; Murakami, Shingo

2015-04-01

Bell's palsy is highly associated with diabetes mellitus (DM). Either the reactivation of herpes simplex virus type 1 (HSV-1) or diabetic mononeuropathy has been proposed to cause the facial paralysis observed in DM patients. However, distinguishing whether the facial palsy is caused by herpetic neuritis or diabetic mononeuropathy is difficult. We previously reported that facial paralysis was aggravated in DM mice after HSV-1 inoculation of the murine auricle. In the current study, we induced HSV-1 reactivation by an auricular scratch following DM induction with streptozotocin (STZ). Controlled animal study. Diabetes mellitus was induced with streptozotocin injection in only mice that developed transient facial nerve paralysis with HSV-1. Recurrent facial palsy was induced after HSV-1 reactivation by auricular scratch. After DM induction, the number of cluster of differentiation 3 (CD3)(+) T cells decreased by 70% in the DM mice, and facial nerve palsy recurred in 13% of the DM mice. Herpes simplex virus type 1 deoxyribonucleic acid (DNA) was detected in the facial nerve of all of the DM mice with palsy, and HSV-1 capsids were found in the geniculate ganglion using electron microscopy. Herpes simplex virus type 1 DNA was also found in some of the DM mice without palsy, which suggested the subclinical reactivation of HSV-1. These results suggested that HSV-1 reactivation in the geniculate ganglion may be the main causative factor of the increased incidence of facial paralysis in DM patients. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

L-citrulline protects from kidney damage in type 1 diabetic mice.

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Maritza J Romero

2013-12-01

Full Text Available Rationale. Diabetic nephropathy is a major cause of end-stage renal disease, associated with endothelial dysfunction. Chronic supplementation of L-arginine (L-arg, the substrate for endothelial nitric oxide synthase (eNOS, failed to improve vascular function. L-citrulline (L-cit supplementation not only increases L-arg synthesis, but also inhibits cytosolic arginase I (Arg I, a competitor of eNOS for the use of L-arg, in the vasculature. Aims. To investigate whether L-cit treatment reduces diabetic nephropathy in streptozotocin (STZ-induced type 1 diabetes in mice and rats and to study its effects on arginase II (ArgII function, the main renal isoform. Methods. STZ-C57BL6 mice received L-cit or vehicle supplemented in the drinking water. For comparative analysis, diabetic ArgII knock out mice and L-cit-treated STZ-rats were evaluated. Results. L-cit exerted protective effects in kidneys of STZ-rats, and markedly reduced urinary albumin excretion, tubulo-interstitial fibrosis and kidney hypertrophy, observed in untreated diabetic mice. Intriguingly, L-cit treatment was accompanied by a sustained elevation of tubular ArgII at 16 wks and significantly enhanced plasma levels of the anti-inflammatory cytokine IL-10. Diabetic ArgII knock out mice showed greater BUN levels, hypertrophy, and dilated tubules than diabetic wild type mice. Despite a marked reduction in collagen deposition in ArgII knock out mice, their albuminuria was not significantly different from diabetic wild type animals. L-cit also restored NO/ROS balance and barrier function in high glucose-treated monolayers of human glomerular endothelial cells. Moreover, L-cit also has the ability to establish an anti-inflammatory profile, characterized by increased IL-10 and reduced IL-1beta and IL-12(p70 generation in the human proximal tubular cells. Conclusions. L-cit supplementation established an anti-inflammatory profile and significantly preserved the nephron function during type 1

Aralia elata inhibits neurodegeneration by downregulating O-GlcNAcylation of NF-κB in diabetic mice

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Seong-Jae Kim

2017-08-01

Full Text Available AIM: To investigate the role of O-GlcNAcylation of nuclear factor-kappa B (NF-κB in retinal ganglion cell (RGC death and analysedthe effect of Aralia elata (AE on neurodegeneration in diabetic mice. METHODS: C57BL/6mice with streptozotocin-induced diabetes were fed daily with AE extract or control (CTL diet at the onset of diabetes mellitus (DM. Two months after injection of streptozotocin or saline, the degree of cell death and the expression of O-GlcNAc transferase (OGT, N-acetyl-b-D-glucosaminidase (OGA, O-GlcNAcylated proteins, and O-GlcNAcylation of NF-κB were examined. RESULTS: AE did not affect the metabolic status of diabetic mice. The decrease in the inner retinal thickness (P<0.001 vs CTL, P<0.01 vs DM and increases in RGCs with terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (P<0.001 vs CTL, P<0.0001 vs DM, glial activation, and active caspase-3 (P<0.0001 vs CTL, P<0.0001 vs DM were blocked in diabetic retinas of AE extract-fed mice. Expression levels of protein O-GlcNAcylation and OGT were increased in diabetic retinas (P<0.0001 vs CTL, and the level of O-GlcNAcylation of the NF-κB p65 subunit was higher in diabetic retinas than in controls (P<0.0001 vs CTL. AE extract downregulated O-GlcNAcylation of NF-κB and prevented neurodegeneration induced by hyperglycemia (P<0.0001 vs DM. CONCLUSION: O-GlcNAcylation of NF-κB is concerned in neuronal degeneration and that AE prevents diabetes-induced RGC apoptosis via downregulation of NF-κB O-GlcNAcylation. Hence, O-GlcNAcylation may be a new object for the treatment of DR, and AE may have therapeutic possibility to prevent diabetes-induced neurodegeneration.

Properties of Flavonoids Isolated from the Bark of Eysenhardtia polystachya and Their Effect on Oxidative Stress in Streptozotocin-Induced Diabetes Mellitus in Mice

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Garcia-Campoy, Abraham Heriberto; Muñiz-Ramirez, Alethia

2016-01-01

Six new flavonoids 2′,4′-dihydroxychalcone-6′-O-β-d-glucopyranoside (1), α,3,2′,4′-tetrahydroxy-4-methoxy-dihydrochalcone-3′-C-β-glucopyranosy-6′-O-β-d-glucopyranoside (2), 7-hydroxy-5,8′-dimethoxy-6′α-l-rhamnopyranosyl-8-(3-phenyl-trans-acryloyl)-1-benzopyran-2-one (3), 6′7-dihydroxy-5,8-dimethoxy-8(3-phenyl-trans-acryloyl)-1-benzopyran-2-one (4), 9-hydroxy-3,8-dimethoxy-4-prenylpterocarpan (5), and α,4,4′-trihydroxydihydrochalcone-2′-O-β-d-glucopyranoside (6) were isolated from bark of Eysenhardtia polystachya. Antidiabetic activity of compounds 1–5 in terms of their cellular antioxidant and free radical scavenging and also in streptozotocin- (STZ-) induced diabetic mice was evaluated on liver transaminases, lipid peroxidation, total bilirubin, total protein, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (CSH-Px), and glutathione reductase (GSH). Results indicated that 1–5 scavenged 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl (∙OH), nitric oxide radicals (NO∙), superoxide anion radical (O2 ∙−), radical cation (ABTS∙+), and hydrogen peroxide (H2O2) radical, and protection against H2O2 induced BSA damage was also observed. Furthermore, 1–5 showed ability to decrease the oxidative stress in H9c2 cell. Diabetic mice present high levels of lipid peroxide, total protein, SGPT, SGOT, ALP, and TB. However, treatment of STZ-induced diabetes in mice with 1–5 reduced levels of these enzymes leading to protector effect of liver. In addition, with treatment with 1–5, increases in radical scavenging enzymes of CSH-Px, SOD, GSH, and CAT have also been observed in diabetic mice. The antioxidant properties of compounds 1–5 are a promising strategy for ameliorating therapeutic effects by avoiding disorders in the normal redox reactions in healthy cells which consequently could alleviate complications of diabetes. PMID:27668038

Proteases in Plasma and Kidney of db/db Mice as Markers of Diabetes-Induced Nephropathy

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Hadler-Olsen, E.; Winberg, J.-O.; Reinholt, F. P.; Larsen, T.; Uhlin-Hansen, L.; Jenssen, T.; Berg, E.; Kolset, S. O.

2011-01-01

Db/db mice are overweight, dyslipidemic and develop diabetic complications, relevant for similar complications in human type 2 diabetes. We have used db/db and db/+ control mice to investigate alterations in proteinase expression and activity in circulation and kidneys by SDS-PAGE zymography, electron microscopy, immunohistochemistry, Western blotting, and in situ zymography. Plasma from db/db mice contained larger amounts of serine proteinases compared to db/+ mice. Kidneys from the db/db mice had a significantly larger glomerular surface area and somewhat thicker glomerular basement membranes compared to the db/+ mice. Furthermore, kidney extracts from db/+ mice contained metalloproteinases with M r of approximately 92000, compatible with MMP-9, not observed in db/db mice. These results indicate that higher levels of serine proteinases in plasma may serve as potential markers for kidney changes in db/db mice, whereas a decrease in MMP-9 in the kidney may be related to the glomerular changes. PMID:22363890

Critical role of IFN-gamma in CFA-mediated protection of NOD mice from diabetes development.

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Mori, Yoshiko; Kodaka, Tetsuro; Kato, Takako; Kanagawa, Edith M; Kanagawa, Osami

2009-11-01

IFN-gamma signaling-deficient non-obese diabetic (NOD) mice develop diabetes with similar kinetics to those of wild-type NOD mice. However, the immunization of IFN-gamma signaling-deficient NOD mice with CFA failed to induce long-term protection, whereas wild-type NOD mice receiving CFA remained diabetes-free. CFA also failed to protect IFN-gamma receptor-deficient (IFN-gammaR(-/-)) NOD mice from the autoimmune rejection of transplanted islets, as it does in diabetic NOD mice, and from disease transfer by spleen cells from diabetic NOD mice. These data clearly show that the pro-inflammatory cytokine IFN-gamma is necessary for the CFA-mediated protection of NOD mice from diabetes. There is no difference in the T(h)1/T(h)17 balance between IFN-gammaR(-/-) NOD and wild-type NOD mice. There is also no difference in the total numbers and percentages of regulatory T (Treg) cells in the lymph node CD4(+) T-cell populations between IFN-gammaR(-/-) NOD and wild-type NOD mice. However, pathogenic T cells lacking IFN-gammaR are resistant to the suppressive effect of Treg cells, both in vivo and in vitro. Therefore, it is likely that CFA-mediated protection against diabetes development depends on a change in the balance between Treg cells and pathogenic T cells, and IFN-gamma signaling seems to control the susceptibility of pathogenic T cells to the inhibitory activity of Treg cells.

Angiotensin converting enzyme 2 amplification limited to the circulation does not protect mice from development of diabetic nephropathy

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Wysocki, Jan; Ye, Minghao; Khattab, Ahmed M.; Fogo, Agnes; Martin, Aline; David, Nicolae Valentin; Kanwar, Yashpal; Osborn, Mark; Batlle, Daniel

2016-01-01

Blockers of the renin-angiotensin system are effective in the treatment of experimental and clinical diabetic nephropathy. An approach different from blocking the formation or action of angiotensin II(1-8) that could also be effective involves fostering its degradation. Angiotensin converting enzyme 2 (ACE2) is a monocarboxypeptidase than cleaves angiotensin II (1-8) to form angiotensin (1-7). Therefore, we examined the renal effects of murine recombinant ACE2 in mice with streptozotocin-induced diabetic nephropathy as well as that of amplification of circulating ACE2 using minicircle DNA delivery prior to induction of experimental diabetes. This delivery resulted in a long-term sustained and profound increase in serum ACE2 activity and enhanced ability to metabolize an acute angiotensin II (1-8) load. In mice with streptozotocin-induced diabetes pretreated with minicircle ACE2, ACE2 protein in plasma increased markedly and this was associated with a more than 100-fold increase in serum ACE2 activity. However, minicircle ACE2 did not result in changes in urinary ACE2 activity as compared to untreated diabetic mice. In both diabetic groups, glomerular filtration rate increased significantly and to the same extent as compared to non-diabetic controls. Albuminuria, glomerular mesangial expansion, glomerular cellularity and glomerular size, were all increased to a similar extent in minicircle ACE2-treated and untreated diabetic mice, as compared to non-diabetic controls. Recombinant mouse ACE2 given for 4 weeks by intraperitoneal daily injections in mice with streptozotocin-induced diabetic nephropathy also failed to improve albuminuria or kidney pathology. Thus, a profound augmentation of ACE2 confined to the circulation failed to ameliorate the glomerular lesions and hyperfiltration characteristic of early diabetic nephropathy. These findings emphasize the importance of targeting the kidney rather than the circulatory renin angiotensin system to combat diabetic

Effects of Hydro-alcoholic Extract from Arctium lappa L. (Burdock) Root on Gonadotropins, Testosterone, and Sperm Count and Viability in Male Mice with Nicotinamide/ Streptozotocin-Induced Type 2 Diabetes.

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Ahangarpour, Akram; Oroojan, Ali Akbar; Heidari, Hamid; Ghaedi, Ehsan; Taherkhani, Reza

2015-01-01

Reproductive dysfunction is a complication of diabetes. Arctium lappa (burdock) root has hypoglycemic and antioxidative properties, which are traditionally used for treatment of impotence and sterility. Therefore, the aim of this study is to investigate the effects of its hydro alcoholic extract on gonadotropin, testosterone, and sperm parameters in nicotinamide/ streptozotocin-induced diabetic mice. In this experimental study, 56 adult male Naval Medical Research Institute (NMRI) mice (30-35 g) were randomly divided into seven groups: control, diabetes, diabetes + glibenclamide (0.25 mg/kg), diabetes + extract (200 or 300 mg/kg), and extract (200 or 300 mg/kg). Diabetes was induced with intraperitoneal injection of nicotinamide (NA) and streptozotocin (STZ). Twenty-four hours after the last extract and drug administration, serum samples, testes, and cauda epididymis were removed immediately for experimental assessment. Body weight, serum luteinizing hormone (LH), follicle stimulating hormone (FSH), and testosterone levels, and sperm count (P lappa plant has an effect on the health of the reproductive system in order to improve diabetic conditions.

Endothelial arginine resynthesis contributes to the maintenance of vasomotor function in male diabetic mice.

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Ramesh Chennupati

Full Text Available Argininosuccinate synthetase (ASS is essential for recycling L-citrulline, the by-product of NO synthase (NOS, to the NOS substrate L-arginine. Here, we assessed whether disturbed arginine resynthesis modulates endothelium-dependent vasodilatation in normal and diabetic male mice.Endothelium-selective Ass-deficient mice (Assfl/fl/Tie2Cretg/- = Ass-KOTie2 were generated by crossing Assfl/fl mice ( = control with Tie2Cre mice. Gene ablation in endothelial cells was confirmed by immunohistochemistry. Blood pressure (MAP was recorded in 34-week-old male mice. Vasomotor responses were studied in isolated saphenous arteries of 12- and 34-week-old Ass-KOTie2 and control animals. At the age of 10 weeks, diabetes was induced in control and Ass-KOTie2 mice by streptozotocin injections. Vasomotor responses of diabetic animals were studied 10 weeks later. MAP was similar in control and Ass-KOTie2 mice. Depletion of circulating L-arginine by arginase 1 infusion or inhibition of NOS activity with L-NAME resulted in an increased MAP (10 and 30 mmHg, respectively in control and Ass-KOTie2 mice. Optimal arterial diameter, contractile responses to phenylephrine, and relaxing responses to acetylcholine and sodium nitroprusside were similar in healthy control and Ass-KOTie2 mice. However, in diabetic Ass-KOTie2 mice, relaxation responses to acetylcholine and endothelium-derived NO (EDNO were significantly reduced when compared to diabetic control mice.Absence of endothelial citrulline recycling to arginine did not affect blood pressure and systemic arterial vasomotor responses in healthy mice. EDNO-mediated vasodilatation was significantly more impaired in diabetic Ass-KOTie2 than in control mice demonstrating that endothelial arginine recycling becomes a limiting endothelial function in diabetes.

Low-Dose Radiation Activates Akt and Nrf2 in the Kidney of Diabetic Mice: A Potential Mechanism to Prevent Diabetic Nephropathy

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Xiao Xing

2012-01-01

Full Text Available Repetitive exposure of diabetic mice to low-dose radiation (LDR at 25 mGy could significantly attenuate diabetes-induced renal inflammation, oxidative damage, remodeling, and dysfunction, for which, however, the underlying mechanism remained unknown. The present study explored the effects of LDR on the expression and function of Akt and Nrf2 in the kidney of diabetic mice. C57BL/6J mice were used to induce type 1 diabetes with multiple low-dose streptozotocin. Diabetic and age-matched control mice were irradiated with whole body X-rays at either single 25 mGy and 75 mGy or accumulated 75 mGy (25 mGy daily for 3 days and then sacrificed at 1–12 h for examining renal Akt phosphorylation and Nrf2 expression and function. We found that 75 mGy of X-rays can stimulate Akt signaling pathway and upregulate Nrf2 expression and function in diabetic kidneys; single exposure of 25 mGy did not, but three exposures to 25 mGy of X-rays could offer a similar effect as single exposure to 75 mGy on the stimulation of Akt phosphorylation and the upregulation of Nrf2 expression and transcription function. These results suggest that single 75 mGy or multiple 25 mGy of X-rays can stimulate Akt phosphorylation and upregulate Nrf2 expression and function, which may explain the prevention of LDR against the diabetic nephropathy mentioned above.

GLUT2 in pancreatic islets: crucial target molecule in diabetes induced with multiple low doses of streptozotocin in mice.

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Wang, Z; Gleichmann, H

1998-01-01

In mice, diabetes can be induced by multiple low doses of streptozotocin (MLD-STZ), i.e., 40 mg/kg body wt on each of 5 consecutive days. In this model, diabetes develops only when STZ induces both beta-cell toxicity and T-cell-dependent immune reactions. The target molecule(s) of MLD-STZ-induced beta-cell toxicity are not known, however. In this study, we report that GLUT2 is a target molecule for MLD-STZ toxicity. Ex vivo, a gradual decrement of both GLUT2 protein and mRNA expression was found in pancreatic islets isolated from MLD-STZ-treated C57BL/6 male mice, whereas mRNA expression of beta-actin, glucokinase, and proinsulin remained unaffected. Significant reduction of both GLUT2 protein and mRNA expression was first noted 1 day after the third STZ injection, clearly preceding the onset of hyperglycemia. The extent of reduction increased with the number of STZ injections administered and increased over time, after the last, i.e., fifth, STZ injection. The STZ-induced reduction of GLUT2 protein and mRNA was not due to an essential loss of beta-cells, because ex vivo, not only the total RNA yield and protein content in isolated islets, but also proinsulin mRNA expression, failed to differ significantly in the differently treated groups. Furthermore, islets isolated from MLD-STZ-treated donors responded to the nonglucose secretagogue arginine in a pattern similar to that of solvent-treated donors. Interestingly, the MLD-STZ-induced reduction of both GLUT2 protein and mRNA was prevented by preinjecting mice with 5-thio-D-glucose before each STZ injection. Apparently, GLUT2 is a crucial target molecule of MLD-STZ toxicity, and this toxicity seems to precede the immune reactions against beta-cells.

Interleukin-6 stimulates Akt and p38 MAPK phosphorylation and fibroblast migration in non-diabetic but not diabetic mice.

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Tsubame Nishikai-Yan Shen

Full Text Available Persistent inflammatory environment and abnormal macrophage activation are characteristics of chronic diabetic wounds. Here, we attempted to characterize the differences in macrophage activation and temporal variations in cytokine expression in diabetic and non-diabetic wounds, with a focus on interleukin (IL-6 mRNA expression and the p38 MAPK and PI3K/Akt signaling pathways. Cutaneous wound closure, CD68- and arginase-1 (Arg-1-expressing macrophages, and cytokine mRNA expression were examined in non-diabetic and streptozotocin-induced type 1 diabetic mice at different time points after injury. The effect of IL-6 on p38 MAPK and Akt phosphorylation was investigated, and an in vitro scratch assay was performed to determine the role of IL-6 in primary skin fibroblast migration. Before injury, mRNA expression levels of the inflammatory markers iNOS, IL-6, and TNF-α were higher in diabetic mice; however, IL-6 expression was significantly lower 6 h post injury in diabetic wounds than that in non-diabetic wounds. Non-diabetic wounds exhibited increased p38 MAPK and Akt phosphorylation; however, no such increase was found in diabetic wounds. In fibroblasts from non-diabetic mice, IL-6 increased the phosphorylation of p38 MAPK and levels of its downstream factor CREB, and also significantly increased Akt phosphorylation and levels of its upstream factor P13K. These effects of IL-6 were not detected in fibroblasts derived from the diabetic mice. In scratch assays, IL-6 stimulated the migration of primary cultured skin fibroblasts from the non-diabetic mice, and the inhibition of p38 MAPK was found to markedly suppress IL-6-stimulated fibroblast migration. These findings underscore the critical differences between diabetic and non-diabetic wounds in terms of macrophage activation, cytokine mRNA expression profile, and involvement of the IL-6-stimulated p38 MAPK-Akt signaling pathway. Aberrant macrophage activation and abnormalities in the cytokine m

Targeting apoptosis signalling kinase-1 (ASK-1 does not prevent the development of neuropathy in streptozotocin-induced diabetic mice.

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Victoria L Newton

Full Text Available Apoptosis signal-regulating kinase-1 (ASK1 is a mitogen-activated protein 3 kinase (MAPKKK/MAP3K which lies upstream of the stress-activated MAPKs, JNK and p38. ASK1 may be activated by a variety of extracellular and intracellular stimuli. MAP kinase activation in the sensory nervous system as a result of diabetes has been shown in numerous preclinical and clinical studies. As a common upstream activator of both p38 and JNK, we hypothesised that activation of ASK1 contributes to nerve dysfunction in diabetic neuropathy. We therefore wanted to characterize the expression of ASK1 in sensory neurons, and determine whether the absence of functional ASK1 would protect against the development of neuropathy in a mouse model of experimental diabetes. ASK1 mRNA and protein is constitutively expressed by multiple populations of sensory neurons of the adult mouse lumbar DRG. Diabetes was induced in male C57BL/6 and transgenic ASK1 kinase-inactive (ASK1n mice using streptozotocin. Levels of ASK1 do not change in the DRG, spinal cord, or sciatic nerve following induction of diabetes. However, levels of ASK2 mRNA increase in the spinal cord at 4 weeks of diabetes, which could represent a future target for this field. Neither motor nerve conduction velocity deficits, nor thermal or mechanical hypoalgesia were prevented or ameliorated in diabetic ASK1n mice. These results suggest that activation of ASK1 is not responsible for the nerve deficits observed in this mouse model of diabetic neuropathy.

Diabetes mellitus induces bone marrow microangiopathy

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Oikawa, Atsuhiko; Siragusa, Mauro; Quaini, Federico; Mangialardi, Giuseppe; Katare, Rajesh G.; Caporali, Andrea; van Buul, Jaap D.; van Alphen, Floris P.J.; Graiani, Gallia; Spinetti, Gaia; Kraenkel, Nicolle; Prezioso, Lucia; Emanueli, Costanza; Madeddu, Paolo

2010-01-01

Objective The impact of diabetes on the bone marrow (BM) microenvironment was not adequately explored. We investigated whether diabetes induces microvascular remodeling with negative consequence for BM homeostasis. Methods and results We found profound structural alterations in BM from type-1 diabetic mice, with depletion of the hematopoietic component and fatty degeneration. Blood flow (fluorescent microspheres) and microvascular density (immunohistochemistry) were remarkably reduced. Flow cytometry verified the depletion of MECA-32pos endothelial cells (ECs). Cultured ECs from BM of diabetic mice showed higher levels of oxidative stress, increased activity of the senescence marker β-galactosidase, reduced migratory and network-formation capacities and increased permeability and adhesiveness to BM mononuclear cells. Flow cytometry analysis of lineageneg c-Kitpos Sca-1pos (LSK) cell distribution along an in vivo Hoechst-33342 dye perfusion gradient documented that diabetes depletes LSK cells predominantly in the low-perfused part of the marrow. Cell depletion was associated to increased oxidative stress, DNA damage and activation of apoptosis. Boosting the anti-oxidative pentose phosphate pathway by benfotiamine supplementation prevented microangiopathy, hypoperfusion and LSK cell depletion. Conclusions We provide novel evidence for the presence of microangiopathy impinging on the integrity of diabetic BM. These discoveries offer the framework for mechanistic solutions of BM dysfunction in diabetes. PMID:20042708

The dual role of scavenger receptor class A in development of diabetes in autoimmune NOD mice.

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Mami Shimizu

Full Text Available Human type 1 diabetes is an autoimmune disease that results from the autoreactive destruction of pancreatic β cells by T cells. Antigen presenting cells including dendritic cells and macrophages are required to activate and suppress antigen-specific T cells. It has been suggested that antigen uptake from live cells by dendritic cells via scavenger receptor class A (SR-A may be important. However, the role of SR-A in autoimmune disease is unknown. In this study, SR-A-/- nonobese diabetic (NOD mice showed significant attenuation of insulitis, lower levels of insulin autoantibodies, and suppression of diabetes development compared with NOD mice. We also found that diabetes progression in SR-A-/- NOD mice treated with low-dose polyinosinic-polycytidylic acid (poly(I:C was significantly accelerated compared with that in disease-resistant NOD mice treated with low-dose poly(I:C. In addition, injection of high-dose poly(I: C to mimic an acute RNA virus infection significantly accelerated diabetes development in young SR-A-/- NOD mice compared with untreated SR-A-/- NOD mice. Pathogenic cells including CD4+CD25+ activated T cells were increased more in SR-A-/- NOD mice treated with poly(I:C than in untreated SR-A-/- NOD mice. These results suggested that viral infection might accelerate diabetes development even in diabetes-resistant subjects. In conclusion, our studies demonstrated that diabetes progression was suppressed in SR-A-/- NOD mice and that acceleration of diabetes development could be induced in young mice by poly(I:C treatment even in SR-A-/- NOD mice. These results suggest that SR-A on antigen presenting cells such as dendritic cells may play an unfavorable role in the steady state and a protective role in a mild infection. Our findings imply that SR-A may be an important target for improving therapeutic strategies for type 1 diabetes.

Neurotensin-loaded collagen dressings reduce inflammation and improve wound healing in diabetic mice.

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Moura, Liane I F; Dias, Ana M A; Suesca, Edward; Casadiegos, Sergio; Leal, Ermelindo C; Fontanilla, Marta R; Carvalho, Lina; de Sousa, Hermínio C; Carvalho, Eugénia

2014-01-01

Impaired wound healing is an important clinical problem in diabetes mellitus and results in failure to completely heal diabetic foot ulcers (DFUs), which may lead to lower extremity amputations. In the present study, collagen based dressings were prepared to be applied as support for the delivery of neurotensin (NT), a neuropeptide that acts as an inflammatory modulator in wound healing. The performance of NT alone and NT-loaded collagen matrices to treat wounds in streptozotocin (STZ) diabetic induced mice was evaluated. Results showed that the prepared dressings were not-cytotoxic up to 72h after contact with macrophages (Raw 264.7) and human keratinocyte (HaCaT) cell lines. Moreover, those cells were shown to adhere to the collagen matrices without noticeable change in their morphology. NT-loaded collagen dressings induced faster healing (17% wound area reduction) in the early phases of wound healing in diabetic wounded mice. In addition, they also significantly reduced inflammatory cytokine expression namely, TNF-α (phealing, metalloproteinase 9 (MMP-9) is reduced in diabetic skin (pdiabetic wound enhancing the healing process. Nevertheless, a more prominent scar is observed in diabetic wounds treated with collagen when compared to the treatment with NT alone. © 2013.

Catalase therapy corrects oxidative stress-induced pathophysiology in incipient diabetic retinopathy.

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Giordano, Courtney R; Roberts, Robin; Krentz, Kendra A; Bissig, David; Talreja, Deepa; Kumar, Ashok; Terlecky, Stanley R; Berkowitz, Bruce A

2015-05-01

Preclinical studies have highlighted retinal oxidative stress in the pathogenesis of diabetic retinopathy. We evaluated whether a treatment designed to enhance cellular catalase reduces oxidative stress in retinal cells cultured in high glucose and in diabetic mice corrects an imaging biomarker responsive to antioxidant therapy (manganese-enhanced magnetic resonance imaging [MEMRI]). Human retinal Müller and pigment epithelial cells were chronically exposed to normal or high glucose levels and treated with a cell-penetrating derivative of the peroxisomal enzyme catalase (called CAT-SKL). Hydrogen peroxide (H2O2) levels were measured using a quantitative fluorescence-based assay. For in vivo studies, streptozotocin (STZ)-induced diabetic C57Bl/6 mice were treated subcutaneously once a week for 3 to 4 months with CAT-SKL; untreated age-matched nondiabetic controls and untreated diabetic mice also were studied. MEMRI was used to analytically assess the efficacy of CAT-SKL treatment on diabetes-evoked oxidative stress-related pathophysiology in vivo. Similar analyses were performed with difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase. After catalase transduction, high glucose-induced peroxide production was significantly lowered in both human retinal cell lines. In diabetic mice in vivo, subnormal intraretinal uptake of manganese was significantly improved by catalase supplementation. In addition, in the peroxisome-rich liver of treated mice catalase enzyme activity increased and oxidative damage (as measured by lipid peroxidation) declined. On the other hand, DFMO was largely without effect in these in vitro or in vivo assays. This proof-of-concept study raises the possibility that augmentation of catalase is a therapy for treating the retinal oxidative stress associated with diabetic retinopathy.

Effects of hydroalcoholic extract of Rhus coriaria seed on glucose and insulin related biomarkers, lipid profile, and hepatic enzymes in nicotinamide-streptozotocin-induced type II diabetic male mice.

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Ahangarpour, Akram; Heidari, Hamid; Junghani, Majid Salehizade; Absari, Reza; Khoogar, Mehdi; Ghaedi, Ehsan

2017-10-01

Type 2 diabetes often leads to dislipidemia and abnormal activity of hepatic enzymes. The purpose of this study was to evaluate the antidiabetic and hypolipidemic properties of Rhus coriaria ( R. coriaria ) seed extrac on nicotinamide-streptozotocin induced type 2 diabetic mice. In this experimental study, 56 male Naval Medical Research Institute mice (30-35 g) were randomly separated into seven groups: control, diabetic group, diabetic mice treated with glibenclamide (0.25 mg/kg, as standard antidiabetic drug) or R. coriaria seed extract in doses of 200 and 300 mg/kg, and control groups received these two doses of extract orally for 28 days. Induction of diabetes was done by intraperitoneal injection of nicotinamide and streptozotocin. Ultimately, body weight of mice, blood levels of glucose, insulin, hepatic enzymes, leptin, and lipid profile were assayed. After induction of type 2 diabetes, level of glucose, cholesterol, low density lipoprotein, serum glutamic oxaloacetic transaminase, and serum glutamic pyruvic transaminase increased and level of insulin and high density lipoprotein decreased remarkably. Administration of both doses of extract decreased level of glucose and cholesterol significantly in diabetic mice. LDL level decreased in treated group with dose of 300 mg/kg of the extract. Although usage of the extract improved level of other lipid profiles, insulin and hepatic enzymes, changes weren't significant. This study showed R. coriaria seeds administration has a favorable effect in controlling some blood parameters in type 2 diabetes. Therefore it may be beneficial in the treatment of diabetes.

Tetrahydrobiopterin Has a Glucose-Lowering Effect by Suppressing Hepatic Gluconeogenesis in an Endothelial Nitric Oxide Synthase–Dependent Manner in Diabetic Mice

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Abudukadier, Abulizi; Fujita, Yoshihito; Obara, Akio; Ohashi, Akiko; Fukushima, Toru; Sato, Yuichi; Ogura, Masahito; Nakamura, Yasuhiko; Fujimoto, Shimpei; Hosokawa, Masaya; Hasegawa, Hiroyuki; Inagaki, Nobuya

2013-01-01

Endothelial nitric oxide synthase (eNOS) dysfunction induces insulin resistance and glucose intolerance. Tetrahydrobiopterin (BH4) is an essential cofactor of eNOS that regulates eNOS activity. In the diabetic state, BH4 is oxidized to 7,8-dihydrobiopterin, which leads to eNOS dysfunction owing to eNOS uncoupling. The current study investigates the effects of BH4 on glucose metabolism and insulin sensitivity in diabetic mice. Single administration of BH4 lowered fasting blood glucose levels in wild-type mice with streptozotocin (STZ)-induced diabetes and alleviated eNOS dysfunction by increasing eNOS dimerization in the liver of these mice. Liver has a critical role in glucose-lowering effects of BH4 through suppression of hepatic gluconeogenesis. BH4 activated AMP kinase (AMPK), and the suppressing effect of BH4 on gluconeogenesis was AMPK-dependent. In addition, the glucose-lowering effect and activation of AMPK by BH4 did not appear in mice with STZ-induced diabetes lacking eNOS. Consecutive administration of BH4 in ob/ob mice ameliorated glucose intolerance and insulin resistance. Taken together, BH4 suppresses hepatic gluconeogenesis in an eNOS-dependent manner, and BH4 has a glucose-lowering effect as well as an insulin-sensitizing effect in diabetic mice. BH4 has potential in the treatment of type 2 diabetes. PMID:23649519

Methadone ameliorates multiple-low-dose streptozotocin-induced type 1 diabetes in mice

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Amirshahrokhi, K.; Dehpour, A.R.; Hadjati, J.; Sotoudeh, M.; Ghazi-Khansari, M.

2008-01-01

Type 1 diabetes is an autoimmune disease characterized by inflammation of pancreatic islets and destruction of β cells by the immune system. Opioids have been shown to modulate a number of immune functions, including T helper 1 (Th1) and T helper 2 (Th2) cytokines. The immunosuppressive effect of long-term administration of opioids has been demonstrated both in animal models and humans. The aim of this study was to determine the effect of methadone, a μ-opioid receptor agonist, on type 1 diabetes. Administration of multiple low doses of streptozotocin (STZ) (MLDS) (40mg/kg intraperitoneally for 5 consecutive days) to mice resulted in autoimmune diabetes. Mice were treated with methadone (10mg/kg/day subcutaneously) for 24days. Blood glucose, insulin and pancreatic cytokine levels were measured. Chronic methadone treatment significantly reduced hyperglycemia and incidence of diabetes, and restored pancreatic insulin secretion in the MLDS model. The protective effect of methadone can be overcome by pretreatment with naltrexone, an opioid receptor antagonist. Also, methadone treatment decreased the proinflammatory Th1 cytokines [interleukin (IL)-1β, tumor necrosis factor-α and interferon-γ] and increased anti-inflammatory Th2 cytokines (IL-4 and IL-10). Histopathological observations indicated that STZ-mediated destruction of β cells was attenuated by methadone treatment. It seems that methadone as an opioid agonist may have a protective effect against destruction of β cells and insulitis in the MLDS model of type 1 diabetes

The anti-ALS drug riluzole attenuates pericyte loss in the diabetic retinopathy of streptozotocin-treated mice

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Choi, Jeong A. [Neural Injury Research Center, Asan Institute for Life Sciences, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Chung, Yoo-Ri [Department of Ophthalmology, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Byun, Hyae-Ran [Neural Injury Research Center, Asan Institute for Life Sciences, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Park, Hwangseo [Department of Bioscience and Biotechnology, Sejong University, Seoul (Korea, Republic of); Koh, Jae-Young, E-mail: jkko@amc.seoul.kr [Neural Injury Research Center, Asan Institute for Life Sciences, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Yoon, Young Hee, E-mail: yhyoon@amc.seoul.kr [Department of Ophthalmology, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

2017-01-15

Loss of pericytes, considered an early hallmark of diabetic retinopathy, is thought to involve abnormal activation of protein kinase C (PKC). We previously showed that the anti-amyotrophic lateral sclerosis (ALS) drug riluzole functions as a PKC inhibitor. Here, we examined the effects of riluzole on pathological changes in diabetic retinopathy. Pathological endpoints examined in vivo included the number of pericytes and integrity of retinal vessels in streptozotocin (STZ)-induced diabetic mice. In addition, PKC activation and the induction of monocyte chemotactic protein (MCP1) were assessed in diabetic mice and in human retinal pericytes exposed to advanced glycation end product (AGE) or modified low-density lipoprotein (mLDL). The diameter of retinal vessels and the number of pericytes were severely reduced, and the levels of MCP1 and PKC were increased in STZ-induced diabetic mice. Administration of riluzole reversed all of these changes. Furthermore, the increased expression of MCP1 in AGE- or mLDL-treated cultured retinal pericytes was inhibited by treatment with riluzole or the PKC inhibitor GF109203X. In silico modeling showed that riluzole fits well within the catalytic pocket of PKC. Taken together, our results demonstrate that riluzole attenuates both MCP1 induction and pericyte loss in diabetic retinopathy, likely through its direct inhibitory effect on PKC. - Highlights: • The effects of riluzole were examined in streptozotocin-induced diabetic mice. • The diameter of retinal vessels and the number of pericytes were severely reduced. • The levels of MCP1 and PKC were increased, while riluzole reversed all changes. • Riluzole attenuated the level of MCP1 in AGE- or mLDL-treated retinal pericytes. • Riluzole attenuated both MCP1 induction and pericyte loss in diabetic retinopathy.

The anti-ALS drug riluzole attenuates pericyte loss in the diabetic retinopathy of streptozotocin-treated mice

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Choi, Jeong A.; Chung, Yoo-Ri; Byun, Hyae-Ran; Park, Hwangseo; Koh, Jae-Young; Yoon, Young Hee

2017-01-01

Loss of pericytes, considered an early hallmark of diabetic retinopathy, is thought to involve abnormal activation of protein kinase C (PKC). We previously showed that the anti-amyotrophic lateral sclerosis (ALS) drug riluzole functions as a PKC inhibitor. Here, we examined the effects of riluzole on pathological changes in diabetic retinopathy. Pathological endpoints examined in vivo included the number of pericytes and integrity of retinal vessels in streptozotocin (STZ)-induced diabetic mice. In addition, PKC activation and the induction of monocyte chemotactic protein (MCP1) were assessed in diabetic mice and in human retinal pericytes exposed to advanced glycation end product (AGE) or modified low-density lipoprotein (mLDL). The diameter of retinal vessels and the number of pericytes were severely reduced, and the levels of MCP1 and PKC were increased in STZ-induced diabetic mice. Administration of riluzole reversed all of these changes. Furthermore, the increased expression of MCP1 in AGE- or mLDL-treated cultured retinal pericytes was inhibited by treatment with riluzole or the PKC inhibitor GF109203X. In silico modeling showed that riluzole fits well within the catalytic pocket of PKC. Taken together, our results demonstrate that riluzole attenuates both MCP1 induction and pericyte loss in diabetic retinopathy, likely through its direct inhibitory effect on PKC. - Highlights: • The effects of riluzole were examined in streptozotocin-induced diabetic mice. • The diameter of retinal vessels and the number of pericytes were severely reduced. • The levels of MCP1 and PKC were increased, while riluzole reversed all changes. • Riluzole attenuated the level of MCP1 in AGE- or mLDL-treated retinal pericytes. • Riluzole attenuated both MCP1 induction and pericyte loss in diabetic retinopathy.

Effects of High Fat Feeding and Diabetes on Regression of Atherosclerosis Induced by Low-Density Lipoprotein Receptor Gene Therapy in LDL Receptor-Deficient Mice.

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Florian Willecke

Full Text Available We tested whether a high fat diet (HFD containing the inflammatory dietary fatty acid palmitate or insulin deficient diabetes altered the remodeling of atherosclerotic plaques in LDL receptor knockout (Ldlr-/- mice. Cholesterol reduction was achieved by using a helper-dependent adenovirus (HDAd carrying the gene for the low-density lipoprotein receptor (Ldlr; HDAd-LDLR. After injection of the HDAd-LDLR, mice consuming either HFD, which led to insulin resistance but not hyperglycemia, or low fat diet (LFD, showed regression compared to baseline. However there was no difference between the two groups in terms of atherosclerotic lesion size, or CD68+ cell and lipid content. Because of the lack of effects of these two diets, we then tested whether viral-mediated cholesterol reduction would lead to defective regression in mice with greater hyperglycemia. In both normoglycemic and streptozotocin (STZ-treated hyperglycemic mice, HDAd-LDLR significantly reduced plasma cholesterol levels, decreased atherosclerotic lesion size, reduced macrophage area and lipid content, and increased collagen content of plaque in the aortic sinus. However, reductions in anti-inflammatory and ER stress-related genes were less pronounced in STZ-diabetic mice compared to non-diabetic mice. In conclusion, HDAd-mediated Ldlr gene therapy is an effective and simple method to induce atherosclerosis regression in Ldlr-/- mice in different metabolic states.

Combination of exercise training and diet restriction normalizes limited exercise capacity and impaired skeletal muscle function in diet-induced diabetic mice.

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Suga, Tadashi; Kinugawa, Shintaro; Takada, Shingo; Kadoguchi, Tomoyasu; Fukushima, Arata; Homma, Tsuneaki; Masaki, Yoshihiro; Furihata, Takaaki; Takahashi, Masashige; Sobirin, Mochamad A; Ono, Taisuke; Hirabayashi, Kagami; Yokota, Takashi; Tanaka, Shinya; Okita, Koichi; Tsutsui, Hiroyuki

2014-01-01

Exercise training (EX) and diet restriction (DR) are essential for effective management of obesity and insulin resistance in diabetes mellitus. However, whether these interventions ameliorate the limited exercise capacity and impaired skeletal muscle function in diabetes patients remains unexplored. Therefore, we investigated the effects of EX and/or DR on exercise capacity and skeletal muscle function in diet-induced diabetic mice. Male C57BL/6J mice that were fed a high-fat diet (HFD) for 8 weeks were randomly assigned for an additional 4 weeks to 4 groups: control, EX, DR, and EX+DR. A lean group fed with a normal diet was also studied. Obesity and insulin resistance induced by a HFD were significantly but partially improved by EX or DR and completely reversed by EX+DR. Although exercise capacity decreased significantly with HFD compared with normal diet, it partially improved with EX and DR and completely reversed with EX+DR. In parallel, the impaired mitochondrial function and enhanced oxidative stress in the skeletal muscle caused by the HFD were normalized only by EX+DR. Although obesity and insulin resistance were completely reversed by DR with an insulin-sensitizing drug or a long-term intervention, the exercise capacity and skeletal muscle function could not be normalized. Therefore, improvement in impaired skeletal muscle function, rather than obesity and insulin resistance, may be an important therapeutic target for normalization of the limited exercise capacity in diabetes. In conclusion, a comprehensive lifestyle therapy of exercise and diet normalizes the limited exercise capacity and impaired muscle function in diabetes mellitus.

Growth factors and medium hyperglycemia induce Sox9+ ductal cell differentiation into β cells in mice with reversal of diabetes

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Zhang, Mingfeng; Lin, Qing; Qi, Tong; Wang, Tiankun; Chen, Ching-Cheng; Riggs, Arthur D.; Zeng, Defu

2016-01-01

We previously reported that long-term administration of a low dose of gastrin and epidermal growth factor (GE) augments β-cell neogenesis in late-stage diabetic autoimmune mice after eliminating insulitis by induction of mixed chimerism. However, the source of β-cell neogenesis is still unknown. SRY (sex-determining region Y)-box 9+ (Sox9+) ductal cells in the adult pancreas are clonogenic and can give rise to insulin-producing β cells in an in vitro culture. Whether Sox9+ ductal cells in the adult pancreas can give rise to β cells in vivo remains controversial. Here, using lineage-tracing with genetic labeling of Insulin- or Sox9-expressing cells, we show that hyperglycemia (>300 mg/dL) is required for inducing Sox9+ ductal cell differentiation into insulin-producing β cells, and medium hyperglycemia (300–450 mg/dL) in combination with long-term administration of low-dose GE synergistically augments differentiation and is associated with normalization of blood glucose in nonautoimmune diabetic C57BL/6 mice. Short-term administration of high-dose GE cannot augment differentiation, although it can augment preexisting β-cell replication. These results indicate that medium hyperglycemia combined with long-term administration of low-dose GE represents one way to induce Sox9+ ductal cell differentiation into β cells in adult mice. PMID:26733677

Annexin V Imaging Detects Diabetes-Accelerated Apoptosis and Monitors the Efficacy of Benfotiamine Treatment in Ischemic Limbs of Mice

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Kyung-Ho Jung

2014-05-01

Full Text Available The role of apoptosis imaging for monitoring treatment response in ischemic limbs has not been properly explored. In this study, we investigated the ability of annexin V (AnxV imaging to assess the efficacy of antiapoptotic treatment in ischemic limbs of diabetic mice. Normal C57BL/6 mice and streptozotocin-induced diabetic mice were subject to hindlimb ischemia. AnxV-conjugated fluorescent streptavidin probes were intravenously injected, and optical imaging was performed. Tissue apoptosis was quantified by histochemistry and Western blotting. The AnxV probes showed specific targeting to apoptotic cells on confocal microscopy and flow cytometry. Intravenous AnxV probes displayed substantially greater accumulation in ischemic limbs of diabetic mice. Benfotiamine (BFT treatment of diabetic mice led to better perfusion recovery on laser Doppler imaging and reduced AnxV binding on optical imaging. TUNEL staining and cleaved caspase-3 Western blots confirmed accelerated apoptosis by diabetes and its suppression by BFT treatment. Furthermore, AnxV-SAv-PEcy5.5 uptake in the ischemic limbs closely correlated to cleaved caspase-3 expression. Thus, AnxV imaging may be useful for monitoring the efficacy of therapeutic agents designed to suppress ischemia-induced apoptosis.

Annexin V imaging detects diabetes-accelerated apoptosis and monitors the efficacy of benfotiamine treatment in ischemic limbs of mice.

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Jung, Kyung-Ho; Lee, Jin Hee; Park, Jin Won; Paik, Jin Young; Quach, Cung Hoa Thien; Lee, Eun Jeong; Lee, Kyung-Han

2014-01-01

The role of apoptosis imaging for monitoring treatment response in ischemic limbs has not been properly explored. In this study, we investigated the ability of annexin V (AnxV) imaging to assess the efficacy of antiapoptotic treatment in ischemic limbs of diabetic mice. Normal C57BL/6 mice and streptozotocin-induced diabetic mice were subject to hindlimb ischemia. AnxV-conjugated fluorescent streptavidin probes were intravenously injected, and optical imaging was performed. Tissue apoptosis was quantified by histochemistry and Western blotting. The AnxV probes showed specific targeting to apoptotic cells on confocal microscopy and flow cytometry. Intravenous AnxV probes displayed substantially greater accumulation in ischemic limbs of diabetic mice. Benfotiamine (BFT) treatment of diabetic mice led to better perfusion recovery on laser Doppler imaging and reduced AnxV binding on optical imaging. TUNEL staining and cleaved caspase-3 Western blots confirmed accelerated apoptosis by diabetes and its suppression by BFT treatment. Furthermore, AnxV-SAv-PEcy5.5 uptake in the ischemic limbs closely correlated to cleaved caspase-3 expression. Thus, AnxV imaging may be useful for monitoring the efficacy of therapeutic agents designed to suppress ischemia-induced apoptosis.

Short term supplementation of dietary antioxidants selectively regulates the inflammatory responses during early cutaneous wound healing in diabetic mice

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Park Na-Young

2011-11-01

Full Text Available Abstract Background Diabetic foot ulcers are serious complications for diabetic patients, yet the precise mechanism that underlines the treatment of these diabetic complications remains unclear. We hypothesized that dietary antioxidant supplementation with vitamin C, combined either with vitamin E or with vitamin E and NAC, improves delayed wound healing through modulation of blood glucose levels, oxidative stress, and inflammatory response. Methods Diabetes was induced by administration of alloxan monohydrate. Mice were divided into 4 groups; CON (non-diabetic control mice fed AIN 93 G purified rodent diet, DM (diabetic mice fed AIN 93 G purified rodent diet, VCE (diabetic mice fed 0.5% vitamin C and 0.5% vitamin E supplemented diet, and Comb (diabetic mice fed 0.5% vitamin C, 0.5% vitamin E, and 2.5% NAC supplemented diet. After 10 days of dietary antioxidant supplementation, cutaneous full-thickness excisional wounds were performed, and the rate of wound closure was examined. TBARS as lipid peroxidation products and vitamin E levels were measured in the liver. Expression levels of oxidative stress and inflammatory response related proteins were measured in the cutaneous wound site. Results Dietary antioxidant supplementation improved blood glucose levels and wound closure rate and increased liver vitamin E, but not liver TBARS levels in the diabetic mice as compared to those of the CON. In addition, dietary antioxidant supplementation modulated the expression levels of pIκBα, HO-1, CuZnSOD, iNOS and COX-2 proteins in the diabetic mice. Conclusions These findings demonstrated that delayed wound healing is associated with an inflammatory response induced by hyperglycaemia, and suggests that dietary antioxidant supplementation may have beneficial effects on wound healing through selective modulation of blood glucose levels, oxidative stress, and inflammatory response.

Exposure to excess insulin (glargine) induces type 2 diabetes mellitus in mice fed on a chow diet.

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Yang, Xuefeng; Mei, Shuang; Gu, Haihua; Guo, Huailan; Zha, Longying; Cai, Junwei; Li, Xuefeng; Liu, Zhenqi; Cao, Wenhong

2014-06-01

We have previously shown that insulin plays an important role in the nutrient-induced insulin resistance. In this study, we tested the hypothesis that chronic exposure to excess long-acting insulin (glargine) can cause typical type 2 diabetes mellitus (T2DM) in normal mice fed on a chow diet. C57BL/6 mice were treated with glargine once a day for 8 weeks, followed by evaluations of food intake, body weight, blood levels of glucose, insulin, lipids, and cytokines, insulin signaling, histology of pancreas, ectopic fat accumulation, oxidative stress level, and cholesterol content in mitochondria in tissues. Cholesterol content in mitochondria and its association with oxidative stress in cultured hepatocytes and β-cells were also examined. Results show that chronic exposure to glargine caused insulin resistance, hyperinsulinemia, and relative insulin deficiency (T2DM). Treatment with excess glargine led to loss of pancreatic islets, ectopic fat accumulation in liver, oxidative stress in liver and pancreas, and increased cholesterol content in mitochondria of liver and pancreas. Prolonged exposure of cultured primary hepatocytes and HIT-TI5 β-cells to insulin induced oxidative stress in a cholesterol synthesis-dependent manner. Together, our results show that chronic exposure to excess insulin can induce typical T2DM in normal mice fed on a chow diet. © 2014 The authors.

Preventive effect of dipeptidyl peptidase-4 inhibitor on atherosclerosis is mainly attributable to incretin's actions in nondiabetic and diabetic apolipoprotein E-null mice.

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Michishige Terasaki

Full Text Available AIM: Several recent reports have revealed that dipeptidyl peptidase (DPP-4 inhibitors have suppressive effects on atherosclerosis in apolipoprotein E-null (Apoe (-/- mice. It remains to be seen, however, whether this effect stems from increased levels of the two active incretins, glucagon-like peptide-1 (GLP-1 and glucose-dependent insulinotropic polypeptide (GIP. METHODS: Nontreated Apoe (-/- mice, streptozotocin-induced diabetic Apoe (-/- mice, and db/db diabetic mice were administered the DPP-4 inhibitor vildagliptin in drinking water and co-infused with either saline, the GLP-1 receptor blocker, exendin(9-39, the GIP receptor blocker, (Pro(3GIP, or both via osmotic minipumps for 4 weeks. Aortic atherosclerosis and oxidized low-density lipoprotein-induced foam cell formation in exudate peritoneal macrophages were determined. RESULTS: Vildagliptin increased plasma GLP-1 and GIP levels without affecting food intake, body weight, blood pressure, or plasma lipid profile in any of the animals tested, though it reduced HbA1c in the diabetic mice. Diabetic Apoe (-/- mice exhibited further-progressed atherosclerotic lesions and foam cell formation compared with nondiabetic counterparts. Nondiabetic and diabetic Apoe (-/- mice showed a comparable response to vildagliptin, namely, remarkable suppression of atherosclerotic lesions with macrophage accumulation and foam cell formation in peritoneal macrophages. Exendin(9-39 or (Pro(3GIP partially attenuated the vildagliptin-induced suppression of atherosclerosis. The two blockers in combination abolished the anti-atherosclerotic effect of vildagliptin in nondiabetic mice but only partly attenuated it in diabetic mice. Vildagliptin suppressed macrophage foam cell formation in nondiabetic and diabetic mice, and this suppressive effect was abolished by infusions with exendin(9-39+(Pro(3GIP. Incubation of DPP-4 or vildagliptin in vitro had no effect on macrophage foam cell formation. CONCLUSIONS: Vildagliptin

GdCl3 reduces hyperglycaemia through Akt/FoxO1-induced suppression of hepatic gluconeogenesis in Type 2 diabetic mice.

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Wang, Qian; Wang, Ning; Dong, Mei; Chen, Fang; Li, Zhong; Chen, Yuanyuan

2014-07-01

GdCl3 (gadolinium chloride) has been shown to reduce blood glucose; however, the underlying mechanism remains unclear. Liver gluconeogenesis is an important pathway involved in the maintenance of glucose homoeostasis. The aim of the present study was to investigate the role of GdCl3 in hepatic gluconeogenesis and explore the precise molecular mechanism. Animals from a classical Type 2 diabetic mouse model, created by exposing C57BL/6J mice to a high-fat diet for 4 months, were treated with GdCl3 or saline. Body weight, blood glucose and insulin sensitivity were monitored. It was observed that GdCl3 significantly reduced blood glucose levels and improved insulin sensitivity. A pyruvate tolerance test showed further that GdCl3 suppressed gluconeogenesis in diabetic mice. In the livers of GdCl3-treated mice, the expression of Pepck (phosphoenolpyruvate carboxykinase) and G6pase (glucose-6-phosphatase), the key enzymes in gluconeogenesis, were dramatically reduced. Furthermore, experiments in hepatocarcinoma cells revealed that GdCl3 activated the Akt pathway to promote the phosphorylation of FoxO1 (forkhead box O1), leading to the suppression of gluconeogenesis by reducing the expression of PEPCK and G6Pase and resulting in decreased cellular production of glucose. Comparable results were observed in the livers of GdCl3-treated mice. In addition, we have shown that GdCl3 augmented the role of insulin to control hepatic glucose production. We conclude that GdCl3 reduces hyperglycaemia via the Akt/FoxO1-induced suppression of hepatic gluconeogenesis, both in Type 2 diabetic mice (in vivo) and in hepatocarcinoma cells (in vitro), suggesting that GdCl3 may be a potential therapeutic agent for diabetes.

Curcumin ameliorates skeletal muscle atrophy in type 1 diabetic mice by inhibiting protein ubiquitination.

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Ono, Taisuke; Takada, Shingo; Kinugawa, Shintaro; Tsutsui, Hiroyuki

2015-09-01

What is the central question of this study? We sought to examine whether curcumin could ameliorate skeletal muscle atrophy in diabetic mice by inhibiting protein ubiquitination, inflammatory cytokines and oxidative stress. What is the main finding and its importance? We found that curcumin ameliorated skeletal muscle atrophy in streptozotocin-induced diabetic mice by inhibiting protein ubiquitination without affecting protein synthesis. This favourable effect of curcumin was possibly due to the inhibition of inflammatory cytokines and oxidative stress. Curcumin may be beneficial for the treatment of muscle atrophy in type 1 diabetes mellitus. Skeletal muscle atrophy develops in patients with diabetes mellitus (DM), especially in type 1 DM, which is associated with chronic inflammation. Curcumin, the active ingredient of turmeric, has various biological actions, including anti-inflammatory and antioxidant properties. We hypothesized that curcumin could ameliorate skeletal muscle atrophy in mice with streptozotocin-induced type 1 DM. C57BL/6 J mice were injected with streptozotocin (200 mg kg(-1) i.p.; DM group) or vehicle (control group). Each group of mice was randomly subdivided into two groups of 10 mice each and fed a diet with or without curcumin (1500 mg kg(-1) day(-1)) for 2 weeks. There were significant decreases in body weight, skeletal muscle weight and cellular cross-sectional area of the skeletal muscle in DM mice compared with control mice, and these changes were significantly attenuated in DM+Curcumin mice without affecting plasma glucose and insulin concentrations. Ubiquitination of protein was increased in skeletal muscle from DM mice and decreased in DM+Curcumin mice. Gene expressions of muscle-specific ubiquitin E3 ligase atrogin-1/MAFbx and MuRF1 were increased in DM and inhibited in DM+Curcumin mice. Moreover, nuclear factor-κB activation, concentrations of the inflammatory cytokines tumour necrosis factor-α and interleukin-1β and oxidative

Transdermal deferoxamine prevents pressure-induced diabetic ulcers.

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Duscher, Dominik; Neofytou, Evgenios; Wong, Victor W; Maan, Zeshaan N; Rennert, Robert C; Inayathullah, Mohammed; Januszyk, Michael; Rodrigues, Melanie; Malkovskiy, Andrey V; Whitmore, Arnetha J; Walmsley, Graham G; Galvez, Michael G; Whittam, Alexander J; Brownlee, Michael; Rajadas, Jayakumar; Gurtner, Geoffrey C

2015-01-06

There is a high mortality in patients with diabetes and severe pressure ulcers. For example, chronic pressure sores of the heels often lead to limb loss in diabetic patients. A major factor underlying this is reduced neovascularization caused by impaired activity of the transcription factor hypoxia inducible factor-1 alpha (HIF-1α). In diabetes, HIF-1α function is compromised by a high glucose-induced and reactive oxygen species-mediated modification of its coactivator p300, leading to impaired HIF-1α transactivation. We examined whether local enhancement of HIF-1α activity would improve diabetic wound healing and minimize the severity of diabetic ulcers. To improve HIF-1α activity we designed a transdermal drug delivery system (TDDS) containing the FDA-approved small molecule deferoxamine (DFO), an iron chelator that increases HIF-1α transactivation in diabetes by preventing iron-catalyzed reactive oxygen stress. Applying this TDDS to a pressure-induced ulcer model in diabetic mice, we found that transdermal delivery of DFO significantly improved wound healing. Unexpectedly, prophylactic application of this transdermal delivery system also prevented diabetic ulcer formation. DFO-treated wounds demonstrated increased collagen density, improved neovascularization, and reduction of free radical formation, leading to decreased cell death. These findings suggest that transdermal delivery of DFO provides a targeted means to both prevent ulcer formation and accelerate diabetic wound healing with the potential for rapid clinical translation.

Dimethyl sulfoxide inhibits spontaneous diabetes and autoimmune recurrence in non-obese diabetic mice by inducing differentiation of regulatory T cells

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Lin, Gu-Jiun; Sytwu, Huey-Kang; Yu, Jyh-Cherng; Chen, Yuan-Wu; Kuo, Yu-Liang; Yu, Chiao-Chi; Chang, Hao-Ming; Chan, De-Chuan; Huang, Shing-Hwa

2015-01-01

Type 1 diabetes mellitus (T1D) is caused by the destruction of insulin-producing β cells in pancreatic islets by autoimmune T cells. Islet transplantation has been established as an effective therapeutic strategy for T1D. However, the survival of islet grafts can be disrupted by recurrent autoimmunity. Dimethyl sulfoxide (DMSO) is a solvent for organic and inorganic substances and an organ-conserving agent used in solid organ transplantations. DMSO also exerts anti-inflammatory, reactive oxygen species scavenger and immunomodulatory effects and therefore exhibits therapeutic potential for the treatment of several human inflammatory diseases. In this study, we investigated the therapeutic potential of DMSO in the inhibition of autoimmunity. We treated an animal model of islet transplantation (NOD mice) with DMSO. The survival of the syngeneic islet grafts was significantly prolonged. The population numbers of CD8, DC and Th1 cells were decreased, and regulatory T (Treg) cell numbers were increased in recipients. The expression levels of IFN-γ and proliferation of T cells were also reduced following DMSO treatment. Furthermore, the differentiation of Treg cells from naive CD4 T cells was significantly increased in the in vitro study. Our results demonstrate for the first time that in vivo DMSO treatment suppresses spontaneous diabetes and autoimmune recurrence in NOD mice by inhibiting the Th1 immune response and inducing the differentiation of Treg cells. - Highlights: • We report a therapeutic potential of DMSO in autoimmune diabetes. • DMSO exhibits an immune modulatory effect. • DMSO treatment increases regulatory T cell differentiation. • The increase in STAT5 signaling pathway explains the effect of DMSO in Tregs

Dimethyl sulfoxide inhibits spontaneous diabetes and autoimmune recurrence in non-obese diabetic mice by inducing differentiation of regulatory T cells

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Lin, Gu-Jiun [Department of Biology and Anatomy, National Defense Medical Center, Taipei, Taiwan, ROC (China); Sytwu, Huey-Kang [Department of Microbiology and Immunology, National Defense Medical Center, Taipei, Taiwan, ROC (China); Yu, Jyh-Cherng [Department of General Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC (China); Chen, Yuan-Wu [School of Dentistry, National Defense Medical Center, Taipei, Taiwan, ROC (China); Department of Oral and Maxillofacial Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC (China); Kuo, Yu-Liang [Department of Medical Imaging, Chung Shan Medical University Hospital, Taichung, Taiwan, ROC (China); School of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan, ROC (China); Yu, Chiao-Chi [Department of Biology and Anatomy, National Defense Medical Center, Taipei, Taiwan, ROC (China); Department of General Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC (China); Chang, Hao-Ming; Chan, De-Chuan [Department of General Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC (China); Huang, Shing-Hwa, E-mail: h610129@gmail.com [Department of Biology and Anatomy, National Defense Medical Center, Taipei, Taiwan, ROC (China); Department of General Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC (China)

2015-01-15

Type 1 diabetes mellitus (T1D) is caused by the destruction of insulin-producing β cells in pancreatic islets by autoimmune T cells. Islet transplantation has been established as an effective therapeutic strategy for T1D. However, the survival of islet grafts can be disrupted by recurrent autoimmunity. Dimethyl sulfoxide (DMSO) is a solvent for organic and inorganic substances and an organ-conserving agent used in solid organ transplantations. DMSO also exerts anti-inflammatory, reactive oxygen species scavenger and immunomodulatory effects and therefore exhibits therapeutic potential for the treatment of several human inflammatory diseases. In this study, we investigated the therapeutic potential of DMSO in the inhibition of autoimmunity. We treated an animal model of islet transplantation (NOD mice) with DMSO. The survival of the syngeneic islet grafts was significantly prolonged. The population numbers of CD8, DC and Th1 cells were decreased, and regulatory T (Treg) cell numbers were increased in recipients. The expression levels of IFN-γ and proliferation of T cells were also reduced following DMSO treatment. Furthermore, the differentiation of Treg cells from naive CD4 T cells was significantly increased in the in vitro study. Our results demonstrate for the first time that in vivo DMSO treatment suppresses spontaneous diabetes and autoimmune recurrence in NOD mice by inhibiting the Th1 immune response and inducing the differentiation of Treg cells. - Highlights: • We report a therapeutic potential of DMSO in autoimmune diabetes. • DMSO exhibits an immune modulatory effect. • DMSO treatment increases regulatory T cell differentiation. • The increase in STAT5 signaling pathway explains the effect of DMSO in Tregs.

The anti diabetic and anti obesity effect of Memecylon umbellatum extract in high fat diet induced obese mice.

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Sunil, V; Shree, Nitya; Venkataranganna, M V; Bhonde, Ramesh R; Majumdar, Mala

2017-05-01

In recent years, obesity and diabetes have become the epidemic mainly due to fast food and lifestyle changes. Several herbs have been claimed to control diabetes and obesity. However, there are a few which control both. Our aim was to evaluate the anti-diabetic and anti-obesity activity of methanolic extract of Memecylon umbellatum (MU) in alleviation of insulin resistance (IR). Diet induced obese (DIO) mice model was developed by feeding the mice on high fat diet (HFD) for 10 weeks resulting in hyperglycemia, obesity and IR. 250mg/kg body weight of extract was administered orally daily for 8 weeks. Fasting glucose and body weight were monitored throughout the experiment. At the end of the study, serum parameters, histological examinations and gene expression pattern were analyzed. There was a significant reduction in fasting glucose levels, body weight and triglycerides. Improvement in the glucose tolerance and amelioration of insulin resistance was observed as revealed by reduction in serum IL6, serum oxidised LDL, histological sections of liver and subcutaneous adipose. Gene expression studies demonstrated the anti-inflammatory activity of the extract by down regulating IL6, PAI1 and ApoB gene expression as compared to the untreated HFD control. Our results demonstrate for the first time that oral administration of methanolic extract of MU in DIO mice leads to reduction in hyperglycemia, body weight, triglycerides and ameliorates insulin resistance. Further, mechanism of action of the extract needs to be investigated by purifying the extract and analyzing the active ingredient playing the major role. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

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

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Toru Hosoi

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

Skeletal Muscle TRIB3 Mediates Glucose Toxicity in Diabetes and High- Fat Diet–Induced Insulin Resistance

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Wu, Mengrui; Kim, Teayoun; Jariwala, Ravi H.; Garvey, W. John; Luo, Nanlan; Kang, Minsung; Ma, Elizabeth; Tian, Ling; Steverson, Dennis; Yang, Qinglin; Fu, Yuchang

2016-01-01

In the current study, we used muscle-specific TRIB3 overexpressing (MOE) and knockout (MKO) mice to determine whether TRIB3 mediates glucose-induced insulin resistance in diabetes and whether alterations in TRIB3 expression as a function of nutrient availability have a regulatory role in metabolism. In streptozotocin diabetic mice, TRIB3 MOE exacerbated, whereas MKO prevented, glucose-induced insulin resistance and impaired glucose oxidation and defects in insulin signal transduction compared with wild-type (WT) mice, indicating that glucose-induced insulin resistance was dependent on TRIB3. In response to a high-fat diet, TRIB3 MOE mice exhibited greater weight gain and worse insulin resistance in vivo compared with WT mice, coupled with decreased AKT phosphorylation, increased inflammation and oxidative stress, and upregulation of lipid metabolic genes coupled with downregulation of glucose metabolic genes in skeletal muscle. These effects were prevented in the TRIB3 MKO mice relative to WT mice. In conclusion, TRIB3 has a pathophysiological role in diabetes and a physiological role in metabolism. Glucose-induced insulin resistance and insulin resistance due to diet-induced obesity both depend on muscle TRIB3. Under physiological conditions, muscle TRIB3 also influences energy expenditure and substrate metabolism, indicating that the decrease and increase in muscle TRIB3 under fasting and nutrient excess, respectively, are critical for metabolic homeostasis. PMID:27207527

Impaired Hedgehog signalling-induced endothelial dysfunction is sufficient to induce neuropathy: implication in diabetes.

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Chapouly, Candice; Yao, Qinyu; Vandierdonck, Soizic; Larrieu-Lahargue, Frederic; Mariani, John N; Gadeau, Alain-Pierre; Renault, Marie-Ange

2016-02-01

Microangiopathy, i.e. endothelial dysfunction, has long been suggested to contribute to the development of diabetic neuropathy, although this has never been fully verified. In the present paper, we have identified the role of Hedgehog (Hh) signalling in endoneurial microvessel integrity and evaluated the impact of impaired Hh signalling in endothelial cells (ECs) on nerve function. By using Desert Hedgehog (Dhh)-deficient mice, we have revealed, that in the absence of Dhh, endoneurial capillaries are abnormally dense and permeable. Furthermore, Smoothened (Smo) conditional KO mice clarified that this increased vessel permeability is specifically due to impaired Hh signalling in ECs and is associated with a down-regulation of Claudin5 (Cldn5). Moreover, impairment of Hh signalling in ECs was sufficient to induce hypoalgesia and neuropathic pain. Finally in Lepr(db/db) type 2 diabetic mice, the loss of Dhh expression observed in the nerve was shown to be associated with increased endoneurial capillary permeability and decreased Cldn5 expression. Conversely, systemic administration of the Smo agonist SAG increased Cldn5 expression, decreased endoneurial capillary permeability, and restored thermal algesia to diabetic mice, demonstrating that loss of Dhh expression is crucial in the development of diabetic neuropathy. The present work demonstrates the critical role of Dhh in maintaining blood nerve barrier integrity and demonstrates for the first time that endothelial dysfunction is sufficient to induce neuropathy. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Intermittent fasting preserves beta-cell mass in obesity-induced diabetes via the autophagy-lysosome pathway.

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Liu, Haiyan; Javaheri, Ali; Godar, Rebecca J; Murphy, John; Ma, Xiucui; Rohatgi, Nidhi; Mahadevan, Jana; Hyrc, Krzysztof; Saftig, Paul; Marshall, Connie; McDaniel, Michael L; Remedi, Maria S; Razani, Babak; Urano, Fumihiko; Diwan, Abhinav

2017-01-01

Obesity-induced diabetes is characterized by hyperglycemia, insulin resistance, and progressive beta cell failure. In islets of mice with obesity-induced diabetes, we observe increased beta cell death and impaired autophagic flux. We hypothesized that intermittent fasting, a clinically sustainable therapeutic strategy, stimulates autophagic flux to ameliorate obesity-induced diabetes. Our data show that despite continued high-fat intake, intermittent fasting restores autophagic flux in islets and improves glucose tolerance by enhancing glucose-stimulated insulin secretion, beta cell survival, and nuclear expression of NEUROG3, a marker of pancreatic regeneration. In contrast, intermittent fasting does not rescue beta-cell death or induce NEUROG3 expression in obese mice with lysosomal dysfunction secondary to deficiency of the lysosomal membrane protein, LAMP2 or haplo-insufficiency of BECN1/Beclin 1, a protein critical for autophagosome formation. Moreover, intermittent fasting is sufficient to provoke beta cell death in nonobese lamp2 null mice, attesting to a critical role for lysosome function in beta cell homeostasis under fasting conditions. Beta cells in intermittently-fasted LAMP2- or BECN1-deficient mice exhibit markers of autophagic failure with accumulation of damaged mitochondria and upregulation of oxidative stress. Thus, intermittent fasting preserves organelle quality via the autophagy-lysosome pathway to enhance beta cell survival and stimulates markers of regeneration in obesity-induced diabetes.

Agmatine ameliorates type 2 diabetes induced-Alzheimer's disease-like alterations in high-fat diet-fed mice via reactivation of blunted insulin signalling.

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Kang, Somang; Kim, Chul-Hoon; Jung, Hosung; Kim, Eosu; Song, Ho-Taek; Lee, Jong Eun

2017-02-01

The risk of Alzheimer's disease (AD) is higher in patients with type 2 diabetes mellitus (T2DM). Previous studies in high-fat diet-induced AD animal models have shown that brain insulin resistance in these animals leads to the accumulation of amyloid beta (Aβ) and the reduction in GSK-3β phosphorylation, which promotes tau phosphorylation to cause AD. No therapeutic treatments that target AD in T2DM patients have yet been discovered. Agmatine, a primary amine derived from l-arginine, has exhibited anti-diabetic effects in diabetic animals. The aim of this study was to investigate the ability of agmatine to treat AD induced by brain insulin resistance. ICR mice were fed a 60% high-fat diet for 12 weeks and received one injection of streptozotocin (100 mg/kg/ip) 4 weeks into the diet. After the 12-week diet, the mice were treated with agmatine (100 mg/kg/ip) for 2 weeks. Behaviour tests were conducted prior to sacrifice. Brain expression levels of the insulin signal molecules p-IRS-1, p-Akt, and p-GSK-3β and the accumulation of Aβ and p-tau were evaluated. Agmatine administration rescued the reduction in insulin signalling, which in turn reduced the accumulation of Aβ and p-tau in the brain. Furthermore, agmatine treatment also reduced cognitive decline. Agmatine attenuated the occurrence of AD in T2DM mice via the activation of the blunted insulin signal. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

L-ARGININE PREVENTS METABOLIC EFFECTS OF HIGH GLUCOSE IN DIABETIC MICE

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West, Matthew B.; Ramana, Kota V.; Kaiserova, Karin; Srivastava, Satish K.; Bhatnagar, Aruni

2008-01-01

We tested the hypothesis that activation of the polyol pathway and protein kinase C (PKC) during diabetes is due to loss of NO. Our results show that after 4 weeks of streptozotocin-induced diabetes, treatment with L-arginine restored NO levels and prevented tissue accumulation of sorbitol in mice, which was accompanied by an increase in glutathiolation of aldose reductase. L-arginine treatment decreased superoxide generation in the aorta, total PKC activity and PKC-βII phosphorylation in the...

Effect of an aqueous extract of Cucurbita ficifolia Bouché on the glutathione redox cycle in mice with STZ-induced diabetes.

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Díaz-Flores, M; Angeles-Mejia, S; Baiza-Gutman, L A; Medina-Navarro, R; Hernández-Saavedra, D; Ortega-Camarillo, C; Roman-Ramos, R; Cruz, M; Alarcon-Aguilar, F J

2012-10-31

Cucurbita ficifolia is used in Mexican traditional medicine as an anti-diabetic and anti-inflammatory agent and its actions can be mediated by antioxidant mechanisms. Disturbance in the homeostasis of glutathione has been implicated in the etiology and progression of diabetes mellitus and its complications. It was evaluated, the effect of an aqueous extract of Cucurbita ficifolia on glycemia, plasma lipid peroxidation; as well as levels of reduced (GSH) and oxidized (GSSG) glutathione and activities of enzymes involved in glutathione redox cycle: glutathione peroxidase (GPx) and glutathione reductase (GR) in liver, pancreas, kidney and heart homogenates of streptozotocin-induced diabetic mice. Increased blood glucose and lipid peroxidation, together with decreased of GSH concentration, GSH/GSSG ratio and its redox potential (E(h)), and enhanced activity of GPx and GR in liver, pancreas and kidney were the salient features observed in diabetic mice. Administration of the aqueous extract of Cucurbita ficifolia to diabetic mice for 30 days, used at a dose of 200 mg/kg, resulted in a significant reduction in glycemia, polydipsia, hyperphagia and plasma lipid peroxidation. Moreover, GSH was increased in liver, pancreas and kidney, and GSSG was reduced in liver, pancreas and heart, therefore GSH/GSSG ratio and its E(h) were restored. Also, the activities involved in the glutathione cycle were decreased, reaching similar values to controls. An aqueous extract of Cucurbita ficifolia with hypoglycemic action, improve GSH redox state, increasing glutathione pool, GSH, GSH/GSSG ratio and its E(h), mechanism that can explain, at least in part, its antioxidant properties, supporting its use as an alternative treatment for the control of diabetes mellitus, and prevent the induction of complications by oxidative stress. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Transdermal deferoxamine prevents pressure-induced diabetic ulcers

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Duscher, Dominik; Neofytou, Evgenios; Wong, Victor W.; Maan, Zeshaan N.; Rennert, Robert C.; Januszyk, Michael; Rodrigues, Melanie; Malkovskiy, Andrey V.; Whitmore, Arnetha J.; Galvez, Michael G.; Whittam, Alexander J.; Brownlee, Michael; Rajadas, Jayakumar; Gurtner, Geoffrey C.

2015-01-01

There is a high mortality in patients with diabetes and severe pressure ulcers. For example, chronic pressure sores of the heels often lead to limb loss in diabetic patients. A major factor underlying this is reduced neovascularization caused by impaired activity of the transcription factor hypoxia inducible factor-1 alpha (HIF-1α). In diabetes, HIF-1α function is compromised by a high glucose-induced and reactive oxygen species-mediated modification of its coactivator p300, leading to impaired HIF-1α transactivation. We examined whether local enhancement of HIF-1α activity would improve diabetic wound healing and minimize the severity of diabetic ulcers. To improve HIF-1α activity we designed a transdermal drug delivery system (TDDS) containing the FDA-approved small molecule deferoxamine (DFO), an iron chelator that increases HIF-1α transactivation in diabetes by preventing iron-catalyzed reactive oxygen stress. Applying this TDDS to a pressure-induced ulcer model in diabetic mice, we found that transdermal delivery of DFO significantly improved wound healing. Unexpectedly, prophylactic application of this transdermal delivery system also prevented diabetic ulcer formation. DFO-treated wounds demonstrated increased collagen density, improved neovascularization, and reduction of free radical formation, leading to decreased cell death. These findings suggest that transdermal delivery of DFO provides a targeted means to both prevent ulcer formation and accelerate diabetic wound healing with the potential for rapid clinical translation. PMID:25535360

Pivotal role of oxidative stress in tumor metastasis under diabetic conditions in mice.

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Ikemura, Mai; Nishikawa, Makiya; Kusamori, Kosuke; Fukuoka, Miho; Yamashita, Fumiyoshi; Hashida, Mitsuru

2013-09-10

Diabetic patients are reported to have a high incidence and mortality of cancer, but little is known about the linkage. In this study, we investigated whether high oxidative stress is involved in the acceleration of tumor metastasis in diabetic mice. Murine melanoma B16-BL6 cells stably labeled with firefly luciferase (B16-BL6/Luc) were inoculated into the tail vein of streptozotocin (STZ)-treated or untreated mice. A luciferase assay demonstrated that tumor cells were present largely in the lung of untreated mice, whereas large numbers of tumor cells were detected in both the lung and liver of STZ-treated mice. Repeated injections of polyethylene glycol-conjugated catalase (PEG-catalase), a long-circulating derivative, reduced the elevated fasting blood glucose levels and plasma lipoperoxide levels of STZ-treated mice, but had no significant effects on these parameters in untreated mice. In addition, the injections significantly reduced the number of tumor cells in the lung and liver in both untreated and STZ-treated mice. Culture of B16-BL6/Luc cells in medium containing over 45 mg/dl glucose hardly affected the proliferation of the cells, whereas the addition of plasma of STZ-treated mice to the medium significantly increased the number of cells. Plasma samples of STZ-treated mice receiving PEG-catalase exhibited no such effect on proliferation. These findings indicate that a hyperglycemia-induced increase in oxidative stress is involved in the acceleration of tumor metastasis, and the removal of systemic hydrogen peroxide by PEG-catalase can inhibit the progression of diabetic conditions and tumor metastasis in diabetes. Copyright © 2013 Elsevier B.V. All rights reserved.

Diabetes-Resistant NOR Mice Are More Severely Affected by Streptozotocin Compared to the Diabetes-Prone NOD Mice: Correlations with Liver and Kidney GLUT2 Expressions

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S. Kahraman

2015-01-01

Full Text Available Nonobese Diabetic (NOD mice are susceptible strains for Type 1 diabetes development, and Nonobese Diabetes-Resistant (NOR mice are defined as suitable controls for NOD mice in non-MHC-related research. Diabetes is often accelerated in NOD mice via Streptozotocin (STZ. STZ is taken inside cells via GLUT2 transmembrane carrier proteins, the major glucose transporter isoforms in pancreatic beta cells, liver, kidneys, and the small intestine. We observed severe adverse effects in NOR mice treated with STZ compared to NOD mice that were made diabetic with a similar dose. We suggested that the underlying mechanism could be differential GLUT2 expressions in pancreatic beta cells, yet immunofluorescent and immunohistochemical studies revealed similar GLUT2 expression levels. We also detected GLUT2 expression profiles in NOD and NOR hepatic and renal tissues by western blot analysis and observed considerably higher GLUT2 expression levels in liver and kidney tissues of NOR mice. Although beta cell GLUT2 expression levels are frequently evaluated as a marker predicting STZ sensitivity in animal models, we report here very different diabetic responses to STZ in two different animal strains, in spite of similar initial GLUT2 expressions in beta cells. Furthermore, use of NOR mice in STZ-mediated experimental diabetes settings should be considered accordingly.

Diacylglycerol kinase ζ inhibits myocardial atrophy and restores cardiac dysfunction in streptozotocin-induced diabetes mellitus

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Sasaki Toshiki

2008-02-01

Full Text Available Abstract Background Activation of the diacylglycerol (DAG-protein kinase C (PKC pathway has been implicated in the pathogenesis of a number of diabetic complications. Diacylglycerol kinase (DGK converts DAG to phosphatidic acid and acts as an endogenous regulator of PKC activity. Akt/PKB is associated with a downstream insulin signaling, and PKCβ attenuates insulin-stimulated Akt phosphorylation. Methods and Results We examined transgenic mice with cardiac-specific overexpression of DGKζ (DGKζ-TG compared to wild type (WT mice in streptozotocin-induced (STZ, 150 mg/kg diabetic and nondiabetic conditions. After 8 weeks, decreases in heart weight and heart weight/body weight ratio in diabetic WT mice were inhibited in DGKζ-TG mice. Echocardiography at 8 weeks after STZ-injection demonstrated that decreases in left ventricular end-diastolic diameter and fractional shortening observed in WT mice were attenuated in DGKζ-TG mice. Thinning of the interventricular septum and the posterior wall in diabetic WT hearts were blocked in DGKζ-TG mice. Reduction of transverse diameter of cardiomyocytes isolated from the left ventricle in diabetic WT mice was attenuated in DGKζ-TG mice. Cardiac fibrosis was much less in diabetic DGKζ-TG than in diabetic WT mice. Western blots showed translocation of PKCβ and δ isoforms to membrane fraction and decreased Akt/PKB phosphorylation in diabetic WT mouse hearts. However in diabetic DGKζ-TG mice, neither translocation of PKC nor changes Akt/PKB phosphorylation was observed. Conclusion DGKζ modulates intracellular signaling and improves the course of diabetic cardiomyopathy. These data may suggest that DGKζ is a new therapeutic target to prevent or reverse diabetic cardiomyopathy.

Marked augmentation of PLGA nanoparticle-induced metabolically beneficial impact of γ-oryzanol on fuel dyshomeostasis in genetically obese-diabetic ob/ob mice.

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Kozuka, Chisayo; Shimizu-Okabe, Chigusa; Takayama, Chitoshi; Nakano, Kaku; Morinaga, Hidetaka; Kinjo, Ayano; Fukuda, Kotaro; Kamei, Asuka; Yasuoka, Akihito; Kondo, Takashi; Abe, Keiko; Egashira, Kensuke; Masuzaki, Hiroaki

2017-11-01

Our previous works demonstrated that brown rice-specific bioactive substance, γ-oryzanol acts as a chaperone, attenuates exaggerated endoplasmic reticulum (ER) stress in brain hypothalamus and pancreatic islets, thereby ameliorating metabolic derangement in high fat diet (HFD)-induced obese diabetic mice. However, extremely low absorption efficiency from intestine of γ-oryzanol is a tough obstacle for the clinical application. Therefore, in this study, to overcome extremely low bioavailability of γ-oryzanol with super-high lipophilicity, we encapsulated γ-oryzanol in polymer poly (DL-lactide-co-glycolide) (PLGA) nanoparticles (Nano-Orz), and evaluated its metabolically beneficial impact in genetically obese-diabetic ob/ob mice, the best-known severest diabetic model in mice. To our surprise, Nano-Orz markedly ameliorated fuel metabolism with an unexpected magnitude (∼1000-fold lower dose) compared with regular γ-oryzanol. Furthermore, such a conspicuous impact was achievable by its administration once every 2 weeks. Besides the excellent impact on dysfunction of hypothalamus and pancreatic islets, Nano-Orz markedly decreased ER stress and inflammation in liver and adipose tissue. Collectively, nanotechnology-based developments of functional foods oriented toward γ-oryzanol shed light on the novel approach for the treatment of a variety of metabolic diseases in humans.

Prunus mume leaf extract lowers blood glucose level in diabetic mice.

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Lee, Min Woo; Kwon, Jung Eun; Lee, Young-Jong; Jeong, Yong Joon; Kim, Inhye; Cho, Young Mi; Kim, Yong-Min; Kang, Se Chan

2016-10-01

Context Diabetes is a common metabolic disease with long-term complications. Prunus mume Sieb. et Zucc. (Rosaceae) fruits have shown to ameliorate glucose intolerance. However, the antidiabetic effects of P. mume leaves have not been investigated. Objective This study evaluated the effects of P. mume leaf 70% ethanol extract (PMLE) on alleviating diabetes in vivo and in vitro. Materials and methods PMLE was fractionated into n-hexane, dichloromethane (CH2Cl2), ethyl acetate (EtOAc), n-butanol (BuOH) and water. Polyphenol and flavonoid contents in PMLE fractions were determined using Folin-Ciocalteu reagent and the aluminium chloride colorimetric method, respectively. We evaluated α-glucosidase inhibition using a microplate reader at 400 nm. Adipocyte differentiation by lipid accumulation was measured using Nile Red staining. Male imprinting control region (ICR) mice were injected with streptozotocin (STZ, 100 mg/kg, i.p.). High-fat diets were provided for three weeks prior to PMLE treatments to induce type 2 diabetes. PMLE (0, 5, 25 or 50 mg/kg) was administrated for four weeks with high-fat diets. Results The EtOAc fraction of PMLE inhibited α-glucosidase activity (IC50 = 68.2 μg/mL) and contained 883.5 ± 14.9 mg/g of polyphenols and 820.1 ± 7.7 mg/g of flavonoids. The 50 mg/kg PMLE supplement reduced 40% of blood glucose level compared to obese/diabetes mice. Obese/diabetic mice treated with 50 mg/kg PMLE showed a lower level of triacylglycerol (320.7 ± 20.73 mg/dL) compared to obese/diabetes mice (494.9 ± 14.80 mg/dL). Conclusion The data demonstrate that P. mume leaves exert antidiabetic effects that may be attributable to high concentrations of polyphenols and flavonoids.

Attenuation of inflammatory response by a novel chalcone protects kidney and heart from hyperglycemia-induced injuries in type 1 diabetic mice

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Fang, Qilu [Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang (China); Diabetes Center and Department of Endocrinology, the Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang (China); Wang, Jingying; Wang, Lintao; Zhang, Yali [Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang (China); Yin, Haimin [Diabetes Center and Department of Endocrinology, the Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang (China); Li, Yunzhou [Hunter Holmes McGuire VA Medical Center, Richmond, VA 23249 (United States); Tong, Chao [Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang (China); Liang, Guang, E-mail: wzmcliangguang@163.com [Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang (China); Zheng, Chao, E-mail: wallbb_1022@163.com [Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang (China); Diabetes Center and Department of Endocrinology, the Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang (China)

2015-10-15

High glucose-induced inflammatory response in diabetic complications plays an important role in disease occurrence and development. With inflammatory cytokines and signaling pathways as important mediators, targeting inflammation may be a new avenue for treating diabetic complications. Chalcones are a class of natural products with various pharmacological activities. Previously, we identified L2H17 as a chalcone with good anti-inflammatory activity, inhibiting LPS-induced inflammatory response in macrophages. In this study, we examined L2H17's effect on hyperglycemia-induced inflammation both in mouse peritoneal macrophages and a streptozotocin-induced T1D mouse model. Our results indicate that L2H17 exhibits a strong inhibitory effect on the expression of pro-inflammatory cytokines, cell adhesion molecules, chemokines and macrophage adhesion via modulation of the MAPK/NF-κB pathway. Furthermore, in vivo oral administration of L2H17 resulted in a significant decrease in the expression of pro-inflammatory cytokines and cell adhesion molecules, contributing to a reduction of key markers for renal and cardiac dysfunction and improvements in fibrosis and pathological changes in both renal and cardiac tissues of diabetic mice. These findings provide the evidence supporting targeting MAPK/NF-κB pathway may be effective therapeutic strategy for diabetic complications, and suggest that L2H17 may be a promising anti-inflammatory agent with potential as a therapeutic agent in the treatment of renal and cardiac diabetic complications. - Highlights: • Chalcones are a class of natural products with various pharmacological activities. • We identified L2H17 a chalcone with good anti-inflammatory activity. • L2H17 improved histological abnormalities both in diabetic heart and kidney. • L2H17 reduced inflammatory responses in HG-stimulated mouse peritoneal macrophages. • MAPKs/NF-κB pathway may be a promising therapeutic target for diabetic complications.

Attenuation of inflammatory response by a novel chalcone protects kidney and heart from hyperglycemia-induced injuries in type 1 diabetic mice

International Nuclear Information System (INIS)

Fang, Qilu; Wang, Jingying; Wang, Lintao; Zhang, Yali; Yin, Haimin; Li, Yunzhou; Tong, Chao; Liang, Guang; Zheng, Chao

2015-01-01

High glucose-induced inflammatory response in diabetic complications plays an important role in disease occurrence and development. With inflammatory cytokines and signaling pathways as important mediators, targeting inflammation may be a new avenue for treating diabetic complications. Chalcones are a class of natural products with various pharmacological activities. Previously, we identified L2H17 as a chalcone with good anti-inflammatory activity, inhibiting LPS-induced inflammatory response in macrophages. In this study, we examined L2H17's effect on hyperglycemia-induced inflammation both in mouse peritoneal macrophages and a streptozotocin-induced T1D mouse model. Our results indicate that L2H17 exhibits a strong inhibitory effect on the expression of pro-inflammatory cytokines, cell adhesion molecules, chemokines and macrophage adhesion via modulation of the MAPK/NF-κB pathway. Furthermore, in vivo oral administration of L2H17 resulted in a significant decrease in the expression of pro-inflammatory cytokines and cell adhesion molecules, contributing to a reduction of key markers for renal and cardiac dysfunction and improvements in fibrosis and pathological changes in both renal and cardiac tissues of diabetic mice. These findings provide the evidence supporting targeting MAPK/NF-κB pathway may be effective therapeutic strategy for diabetic complications, and suggest that L2H17 may be a promising anti-inflammatory agent with potential as a therapeutic agent in the treatment of renal and cardiac diabetic complications. - Highlights: • Chalcones are a class of natural products with various pharmacological activities. • We identified L2H17 a chalcone with good anti-inflammatory activity. • L2H17 improved histological abnormalities both in diabetic heart and kidney. • L2H17 reduced inflammatory responses in HG-stimulated mouse peritoneal macrophages. • MAPKs/NF-κB pathway may be a promising therapeutic target for diabetic complications.

Anti-Diabetic Effects of CTB-APSL Fusion Protein in Type 2 Diabetic Mice

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Yunlong Liu

2014-03-01

Full Text Available To determine whether cholera toxin B subunit and active peptide from shark liver (CTB-APSL fusion protein plays a role in treatment of type 2 diabetic mice, the CTB-APSL gene was cloned and expressed in silkworm (Bombyx mori baculovirus expression vector system (BEVS, then the fusion protein was orally administrated at a dose of 100 mg/kg for five weeks in diabetic mice. The results demonstrated that the oral administration of CTB-APSL fusion protein can effectively reduce the levels of both fasting blood glucose (FBG and glycosylated hemoglobin (GHb, promote insulin secretion and improve insulin resistance, significantly improve lipid metabolism, reduce triglycerides (TG, total cholesterol (TC and low density lipoprotein (LDL levels and increase high density lipoprotein (HDL levels, as well as effectively improve the inflammatory response of type 2 diabetic mice through the reduction of the levels of inflammatory cytokines tumor necrosis factor-α (TNF-α and interleukin-6 (IL-6. Histopathology shows that the fusion protein can significantly repair damaged pancreatic tissue in type 2 diabetic mice, significantly improve hepatic steatosis and hepatic cell cloudy swelling, reduce the content of lipid droplets in type 2 diabetic mice, effectively inhibit renal interstitial inflammatory cells invasion and improve renal tubular epithelial cell nucleus pyknosis, thus providing an experimental basis for the development of a new type of oral therapy for type 2 diabetes.

Resolvin D1 promotes corneal epithelial wound healing and restoration of mechanical sensation in diabetic mice.

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Zhang, Zhenzhen; Hu, Xiaoli; Qi, Xia; Di, Guohu; Zhang, Yangyang; Wang, Qian; Zhou, Qingjun

2018-01-01

To investigate the effect and mechanism of proresolving lipid mediator resolvin D1 (RvD1) on the corneal epithelium and the restoration of mechanical sensation in diabetic mice. Type 1 diabetes was induced in mice with intraperitoneal streptozocin injections. The healthy and diabetic mice underwent removal of the central corneal epithelium, and then 100 ng/ml RvD1 or its formyl peptide receptor 2 (FPR2) antagonist WRW4 was used to treat the diabetic mice. Regeneration of the corneal epithelium and nerves was observed with sodium fluorescein staining and whole-mount anti-β3-tubulin fluorescence staining. The inflammatory response level was measured with hematoxylin and eosin staining (inflammatory cell infiltration), enzyme-linked immunosorbent assay (tumor necrosis factor alpha and interleukin-1 beta content), myeloperoxidase activity, and fluorescence staining (macrophage content). The reactive oxygen species (ROS) and glutathione (GSH) levels were examined with incubation with fluorescent probes, and oxidative stress-related protein expression levels were evaluated with fluorescence staining and western blotting. Topical application of RvD1 promoted regeneration of the corneal epithelium in diabetic mice, accompanied by the reactivation of signaling and inflammation resolution related to regeneration of the epithelium. Furthermore, RvD1 directly attenuated the accumulation of ROS and nicotinamide adenine dinucleotide phosphate oxidase 2/4 expression, while RvD1 enhanced GSH synthesis and reactivated the Nrf2-ARE signaling pathway that was impaired in the corneal epithelium in the diabetic mice. More interestingly, topical application of RvD1 promoted regeneration of corneal nerves and completely restored impaired mechanical sensitivity of the cornea in diabetic mice. In addition, the promotion of corneal epithelial wound healing by RvD1 in diabetic mice was abolished by its FPR2 antagonist WRW4. Topical application of RvD1 promotes corneal epithelial wound

Increased plasma citrulline in mice marks diet-induced obesity and may predict the development of the metabolic syndrome.

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Manuela Sailer

Full Text Available In humans, plasma amino acid concentrations of branched-chain amino acids (BCAA and aromatic amino acids (AAA increase in states of obesity, insulin resistance and diabetes. We here assessed whether these putative biomarkers can also be identified in two different obesity and diabetic mouse models. C57BL/6 mice with diet-induced obesity (DIO mimic the metabolic impairments of obesity in humans characterized by hyperglycemia, hyperinsulinemia and hepatic triglyceride accumulation. Mice treated with streptozotocin (STZ to induce insulin deficiency were used as a type 1 diabetes model. Plasma amino acid profiling of two high fat (HF feeding trials revealed that citrulline and ornithine concentrations are elevated in obese mice, while systemic arginine bioavailability (ratio of plasma arginine to ornithine + citrulline is reduced. In skeletal muscle, HF feeding induced a reduction of arginine levels while citrulline levels were elevated. However, arginine or citrulline remained unchanged in their key metabolic organs, intestine and kidney. Moreover, the intestinal conversion of labeled arginine to ornithine and citrulline in vitro remained unaffected by HF feeding excluding the intestine as prime site of these alterations. In liver, citrulline is mainly derived from ornithine in the urea cycle and DIO mice displayed reduced hepatic ornithine levels. Since both amino acids share an antiport mechanism for mitochondrial import and export, elevated plasma citrulline may indicate impaired hepatic amino acid handling in DIO mice. In the insulin deficient mice, plasma citrulline and ornithine levels also increased and additionally these animals displayed elevated BCAA and AAA levels like insulin resistant and diabetic patients. Therefore, type 1 diabetic mice but not DIO mice show the "diabetic fingerprint" of plasma amino acid changes observed in humans. Additionally, citrulline may serve as an early indicator of the obesity-dependent metabolic

Anti-diabetic effects of rice hull smoke extract on glucose-regulating mechanism in type 2 diabetic mice

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The aim of this study is to determine the protective effect of a liquid rice hull smoke extract (RHSE) against type 2 diabetes induced by a high fat diet administered to mice. Dietary administration of 0.5% or 1% RHSE for 7 weeks results in significantly reduced blood glucose and triglyceride and to...

Anti-oxidant effect of gold nanoparticles restrains hyperglycemic conditions in diabetic mice

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Eom SooHyun

2010-07-01

Full Text Available Abstract Background Oxidative stress is imperative for its morbidity towards diabetic complications, where abnormal metabolic milieu as a result of hyperglycemia, leads to the onset of several complications. A biological antioxidant capable of inhibiting oxidative stress mediated diabetic progressions; during hyperglycemia is still the need of the era. The current study was performed to study the effect of biologically synthesized gold nanoparticles (AuNPs to control the hyperglycemic conditions in streptozotocin induced diabetic mice. Results The profound control of AuNPs over the anti oxidant enzymes such as GSH, SOD, Catalase and GPx in diabetic mice to normal, by inhibition of lipid peroxidation and ROS generation during hyperglycemia evidence their anti-oxidant effect during hyperglycemia. The AuNPs exhibited an insistent control over the blood glucose level, lipids and serum biochemical profiles in diabetic mice near to the control mice provokes their effective role in controlling and increasing the organ functions for better utilization of blood glucose. Histopathological and hematological studies revealed the non-toxic and protective effect of the gold nanoparticles over the vital organs when administered at dosage of 2.5 mg/kilogram.body.weight/day. ICP-MS analysis revealed the biodistribution of gold nanoparticles in the vital organs showing accumulation of AuNPs in the spleen comparatively greater than other organs. Conclusion The results obtained disclose the effectual role of AuNPs as an anti-oxidative agent, by inhibiting the formation of ROS, scavenging free radicals; thus increasing the anti-oxidant defense enzymes and creating a sustained control over hyperglycemic conditions which consequently evoke the potential of AuNPs as an economic therapeutic remedy in diabetic treatments and its complications.

Angiotensin-converting enzyme 2 amplification limited to the circulation does not protect mice from development of diabetic nephropathy.

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Wysocki, Jan; Ye, Minghao; Khattab, Ahmed M; Fogo, Agnes; Martin, Aline; David, Nicolae Valentin; Kanwar, Yashpal; Osborn, Mark; Batlle, Daniel

2017-06-01

Blockers of the renin-angiotensin system are effective in the treatment of experimental and clinical diabetic nephropathy. An approach different from blocking the formation or action of angiotensin II (1-8) that could also be effective involves fostering its degradation. Angiotensin-converting enzyme 2 (ACE2) is a monocarboxypeptidase that cleaves angiotensin II (1-8) to form angiotensin (1-7). Therefore, we examined the renal effects of murine recombinant ACE2 in mice with streptozotocin-induced diabetic nephropathy as well as that of amplification of circulating ACE2 using minicircle DNA delivery prior to induction of experimental diabetes. This delivery resulted in a long-term sustained and profound increase in serum ACE2 activity and enhanced ability to metabolize an acute angiotensin II (1-8) load. In mice with streptozotocin-induced diabetes pretreated with minicircle ACE2, ACE2 protein in plasma increased markedly and this was associated with a more than 100-fold increase in serum ACE2 activity. However, minicircle ACE2 did not result in changes in urinary ACE2 activity as compared to untreated diabetic mice. In both diabetic groups, glomerular filtration rate increased significantly and to the same extent as compared to non-diabetic controls. Albuminuria, glomerular mesangial expansion, glomerular cellularity, and glomerular size were all increased to a similar extent in minicircle ACE2-treated and untreated diabetic mice, as compared to non-diabetic controls. Recombinant mouse ACE2 given for 4 weeks by intraperitoneal daily injections in mice with streptozotocin-induced diabetic nephropathy also failed to improve albuminuria or kidney pathology. Thus, a profound augmentation of ACE2 confined to the circulation failed to ameliorate the glomerular lesions and hyperfiltration characteristic of early diabetic nephropathy. These findings emphasize the importance of targeting the kidney rather than the circulatory renin angiotensin system to combat diabetic

Effects of Hydro-alcoholic Extract from Arctium lappa L. (Burdock) Root on Gonadotropins, Testosterone, and Sperm Count and Viability in Male Mice with Nicotinamide/ Streptozotocin-Induced Type 2 Diabetes

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AHANGARPOUR, Akram; OROOJAN, Ali Akbar; HEIDARI, Hamid; GHAEDI, Ehsan; TAHERKHANI, Reza

2015-01-01

Background: Reproductive dysfunction is a complication of diabetes. Arctium lappa (burdock) root has hypoglycemic and antioxidative properties, which are traditionally used for treatment of impotence and sterility. Therefore, the aim of this study is to investigate the effects of its hydro alcoholic extract on gonadotropin, testosterone, and sperm parameters in nicotinamide/ streptozotocin-induced diabetic mice.

Cholera toxin subunit B peptide fusion proteins reveal impaired oral tolerance induction in diabetes-prone but not in diabetes-resistant mice.

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Presa, Maximiliano; Ortiz, Angela Zarama; Garabatos, Nahir; Izquierdo, Cristina; Rivas, Elisa I; Teyton, Luc; Mora, Conchi; Serreze, David; Stratmann, Thomas

2013-11-01

The cholera toxin B subunit (CTB) has been used as adjuvant to improve oral vaccine delivery in type 1 diabetes. The effect of CTB/peptide formulations on Ag-specific CD4(+) T cells has remained largely unexplored. Here, using tetramer analysis, we investigated how oral delivery of CTB fused to two CD4(+) T-cell epitopes, the BDC-2.5 T-cell 2.5 mi mimotope and glutamic acid decarboxylase (GAD) 286-300, affected diabetogenic CD4(+) T cells in nonobese diabetic (NOD) mice. When administered i.p., CTB-2.5 mi activated 2.5 mi(+) T cells and following intragastric delivery generated Ag-specific Foxp3(+) Treg and Th2 cells. While 2.5 mi(+) and GAD-specific T cells were tolerized in diabetes-resistant NODxB6.Foxp3(EGFP) F1 and nonobese resistant (NOR) mice, this did not occur in NOD mice. This indicated that NOD mice had a recessive genetic resistance to induce oral tolerance to both CTB-fused epitopes. In contrast to NODxB6.Foxp3(EGFP) F1 mice, oral treatment in NOD mice lead to strong 2.5 mi(+) T-cell activation and the sequestration of these cells to the effector-memory pool. Oral treatment of NOD mice with CTB-2.5 mi failed to prevent diabetes. These findings underline the importance of investigating the effect of oral vaccine formulations on diabetogenic T cells as in selected cases they may have counterproductive consequences in human patients. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Experimental treatment of diabetic mice with microencapsulated rat islet cells transplantation

International Nuclear Information System (INIS)

Luo Yun; Xue Yilong; Li Yanling; Li Xinjian

2006-01-01

To observe treatment effects of diabetic mice with microcapsulated and non-microcapsulated rat islet cell transplantation, pancreas of SD rat was perfused with collagenase through cloledchus, and then the pancreatic tissues were isolated and digested. Histopaque-1077 was used to purify the digested pancreas. Islet cells were collected and implanted into the peritoneal cavity of diabetic mice. The isolated islets had a response upon glucose stimulation. When the microcapsulated islets and non- microcapsulated islets were transplanted into diabetic mices the high blood glucose level could be decreased to normal. The normal blood glucose level in the diabetic mice transpanted with microcapsulated islets could be maintained for over 30 days,but it could be mainlained only for 2-3 days in the diabetic mice transplanted with non-microcapsulated islets. Thus it is believed that microcapsulated islet cell transplantation exerts good effect on diabetic mice and the microcapsules possessed good immunoisolating function. (authors)

Influence of TRPV1 on diabetes-induced alterations in thermal pain sensitivity

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Pauza Mary E

2008-03-01

Full Text Available Abstract A common complication associated with diabetes is painful or painless diabetic peripheral neuropathy (DPN. The mechanisms and determinants responsible for these peripheral neuropathies are poorly understood. Using both streptozotocin (STZ-induced and transgene-mediated murine models of type 1 diabetes (T1D, we demonstrate that Transient Receptor Potential Vanilloid 1 (TRPV1 expression varies with the neuropathic phenotype. We have found that both STZ- and transgene-mediated T1D are associated with two distinct phases of thermal pain sensitivity that parallel changes in TRPV1 as determined by paw withdrawal latency (PWL. An early phase of hyperalgesia and a late phase of hypoalgesia are evident. TRPV1-mediated whole cell currents are larger and smaller in dorsal root ganglion (DRG neurons collected from hyperalgesic and hypoalgesic mice. Resiniferatoxin (RTX binding, a measure of TRPV1 expression is increased and decreased in DRG and paw skin of hyperalgesic and hypoalgesic mice, respectively. Immunohistochemical labeling of spinal cord lamina I and II, dorsal root ganglion (DRG, and paw skin from hyperalgesic and hypoalgesic mice reveal increased and decreased TRPV1 expression, respectively. A role for TRPV1 in thermal DPN is further suggested by the failure of STZ treatment to influence thermal nociception in TRPV1 deficient mice. These findings demonstrate that altered TRPV1 expression and function contribute to diabetes-induced changes in thermal perception.

NETosis Delays Diabetic Wound Healing in Mice and Humans.

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Fadini, Gian Paolo; Menegazzo, Lisa; Rigato, Mauro; Scattolini, Valentina; Poncina, Nicol; Bruttocao, Andrea; Ciciliot, Stefano; Mammano, Fabio; Ciubotaru, Catalin Dacian; Brocco, Enrico; Marescotti, Maria Cristina; Cappellari, Roberta; Arrigoni, Giorgio; Millioni, Renato; Vigili de Kreutzenberg, Saula; Albiero, Mattia; Avogaro, Angelo

2016-04-01

Upon activation, neutrophils undergo histone citrullination by protein arginine deiminase (PAD)4, exocytosis of chromatin and enzymes as neutrophil extracellular traps (NETs), and death. In diabetes, neutrophils are primed to release NETs and die by NETosis. Although this process is a defense against infection, NETosis can damage tissue. Therefore, we examined the effect of NETosis on the healing of diabetic foot ulcers (DFUs). Using proteomics, we found that NET components were enriched in nonhealing human DFUs. In an independent validation cohort, a high concentration of neutrophil elastase in the wound was associated with infection and a subsequent worsening of the ulcer. NET components (elastase, histones, neutrophil gelatinase-associated lipocalin, and proteinase-3) were elevated in the blood of patients with DFUs. Circulating elastase and proteinase-3 were associated with infection, and serum elastase predicted delayed healing. Neutrophils isolated from the blood of DFU patients showed an increased spontaneous NETosis but an impaired inducible NETosis. In mice, skin PAD4 activity was increased by diabetes, and FACS detection of histone citrullination, together with intravital microscopy, showed that NETosis occurred in the bed of excisional wounds. PAD4 inhibition by Cl-amidine reduced NETting neutrophils and rescued wound healing in diabetic mice. Cumulatively, these data suggest that NETosis delays DFU healing. © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Deletion of the Men1 Gene Prevents Streptozotocin-Induced Hyperglycemia in Mice

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Yuqing Yang

2010-01-01

Full Text Available Diabetes ultimately results from an inadequate number of functional beta cells in the islets of Langerhans. Enhancing proliferation of functional endogenous beta cells to treat diabetes remains underexplored. Here, we report that excision of the Men1 gene, whose loss-of-function mutation leads to inherited multiple endocrine neoplasia type 1 (MEN1, rendered resistant to streptozotocin-induced hyperglycemia in a tamoxifen-inducible and temporally controlled Men1 excision mouse model as well as in a tissue-specific Men1 excision mouse model. Men1 excision prevented mice from streptozotocin-induced hyperglycemia mainly through increasing the number of functional beta cells. BrdU incorporation by beta cells, islet size, and circulating insulin levels were significantly increased in Men1-excised mice. Membrane localization of glucose transporter 2 was largely preserved in Men1-excised beta cells, but not in Men1-expressing beta cells. Our findings suggest that repression of menin, a protein encoded by the Men1 gene, might be a valuable means to maintain or increase the number of functional endogenous beta cells to prevent or ameliorate diabetes.

A bispecific protein capable of engaging CTLA-4 and MHCII protects non-obese diabetic mice from autoimmune diabetes.

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Hongmei Zhao

Full Text Available Crosslinking ligand-engaged cytotoxic T lymphocyte antigen-4 (CTLA-4 to the T cell receptor (TCR with a bispecific fusion protein (BsB comprised of a mutant mouse CD80 and lymphocyte activation antigen-3 (LAG-3 has been shown to attenuate TCR signaling and to direct T-cell differentiation toward Foxp3(+ regulatory T cells (Tregs in an allogenic mixed lymphocyte reaction (MLR. Here, we show that antigen-specific Tregs can also be induced in an antigen-specific setting in vitro. Treatment of non-obese diabetic (NOD female mice between 9-12 weeks of age with a short course of BsB elicited a transient increase of Tregs in the blood and moderately delayed the onset of autoimmune type 1 diabetes (T1D. However, a longer course of treatment (10 weeks of 4-13 weeks-old female NOD animals with BsB significantly delayed the onset of disease or protected animals from developing diabetes, with only 13% of treated animals developing diabetes by 35 weeks of age compared to 80% of the animals in the control group. Histopathological analysis of the pancreata of the BsB-treated mice that remained non-diabetic revealed the preservation of insulin-producing β-cells despite the presence of different degrees of insulitis. Thus, a bifunctional protein capable of engaging CTLA-4 and MHCII and indirectly co-ligating CTLA-4 to the TCR protected NOD mice from developing T1D.

A comparative profile of methanol extracts of Allium cepa and Allium sativum in diabetic neuropathy in mice

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Bhanot, Abhishek; Shri, Richa

2010-01-01

Introduction: Diabetic Neuropathy (DN) is a major microvascular complication of uncontrolled diabetes. This may result from increased oxidative stress that accompanies diabetes. Hence plants with antioxidant action play an important role in management of diabetes and its complications. Materials and Methods: This study was designed to evaluate preventive as well as curative effect of methanol extracts of outer scales and edible portions of two plants with established antioxidant action - Allium cepa and Allium sativum, in induced DN in albino mice. Mice were divided into control, diabetic and test extracts treated groups. Test extracts were administered daily at a dose of 200 mg/kg p.o. for 21 days, in the preventive group prior to onset of DN, and in the curative group after the onset of DN. Hyperalgesia and oxidative stress markers were assessed. STZ-diabetic mice showed a significant thermal hyperalgesia (as assessed by the tail-flick test), indicating development of DN. Results: Treatment with test extracts prevented loss in body weight, decreased plasma glucose level, and significantly ameliorated the hyperalgesia, TBARS, serum nitrite and GSH levels in diabetic mice. Conclusion: Methanol extract of outer scales of onion has shown most significant improvement; may be due to higher content of phenolic compounds in outer scales of A. cepa. PMID:21713142

B lymphocytes not required for progression from insulitis to diabetes in non-obese diabetic mice.

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Charlton, B; Zhang, M D; Slattery, R M

2001-12-01

Previous studies have implicated B lymphocytes in the pathogenesis of diabetes in the non-obese diabetic (NOD) mouse. While it is clear that B lymphocytes are necessary, it has not been clear at which stage of disease they play a role; early, late or both. To clarify when B lymphocytes are needed, T lymphocytes were transferred from 5-week-old NOD female mice to age-matched NOD/severe combined immunodeficiency (SCID) recipient mice. NOD/SCID mice, which lack functionally mature T and B lymphocytes, do not normally develop insulitis or insulin-dependent diabetes melitus (IDDM). The NOD/SCID mice that received purified T lymphocytes from 5-week-old NOD mice subsequently developed insulitis and diabetes even though they did not have detectable B lymphocytes. This suggests that while B lymphocytes may be essential for an initial priming event they are not requisite for disease progression in the NOD mouse.

Evaluation of the Effects of Novel Nafimidone Derivatives on Thermal Hypoalgesia in Mice with Diabetic Neuropathy

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Suat Kamışlı

2013-03-01

Full Text Available Objective: Diabetic neuropathy (DN is a common complication in Diabetes Mellitus. The streptozotocin-induced diabetic rodent is the most commonly used animal model of diabetes and increased sodium channel expression and activity were revealed in this model. At this study, we evaluated the effect of three different nafimidone derivatives which have possible anticonvulsant activity on disorders of thermal pain sensation in diabetic mice. Study Design: Randomized animal experiment. Material and Methods: Mice were divided randomly into five groups (5 mice per group: Control, Diabetes, Dibetes+C1, Diabetes+C2, Diabetes+C3. We used hot and cold plate, and tail-immersion tests for assessment of thermal nociceptive responses. Results: Compared with the control group, the hot-plate response time and the number of paw liftings on cold plate as important indicators of loss of sensation increased, but no significant difference (p>0.05 was found in tail-immersion response time test in diabetes group. C3 compound moved it back to control group levels in the all of three tests. C1 and C2 compounds were effective only in cold-plate test. Conclusion: Nafimidone derivatives may be effective in the cases where epilepsy and diabetes occur together since it has shown efficacy against “loss of sensation” which evolves in diabetic neuropathy over time as well as its antiepileptic effect.

Inhibiting Heat-Shock Protein 90 Reverses Sensory Hypoalgesia in Diabetic Mice

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Michael J Urban

2010-07-01

Full Text Available Increasing the expression of Hsp70 (heat-shock protein 70 can inhibit sensory neuron degeneration after axotomy. Since the onset of DPN (diabetic peripheral neuropathy is associated with the gradual decline of sensory neuron function, we evaluated whether increasing Hsp70 was sufficient to improve several indices of neuronal function. Hsp90 is the master regulator of the heat-shock response and its inhibition can up-regulate Hsp70. KU-32 (N-{7-[(2R, 3R, 4S, 5R-3, 4-dihydroxy-5-methoxy-6, 6-dimethyl-tetrahydro-2H-pyran-2-yloxy]-8-methyl-2-oxo-2H-chromen-3-yl}acetamide was developed as a novel, novobiocin-based, C-terminal inhibitor of Hsp90 whose ability to increase Hsp70 expression is linked to the presence of an acetamide substitution of the prenylated benzamide moiety of novobiocin. KU-32 protected against glucose-induced death of embryonic DRG (dorsal root ganglia neurons cultured for 3 days in vitro. Similarly, KU-32 significantly decreased neuregulin 1-induced degeneration of myelinated Schwann cell DRG neuron co-cultures prepared from WT (wild-type mice. This protection was lost if the co-cultures were prepared from Hsp70.1 and Hsp70.3 KO (knockout mice. KU-32 is readily bioavailable and was administered once a week for 6 weeks at a dose of 20 mg/kg to WT and Hsp70 KO mice that had been rendered diabetic with streptozotocin for 12 weeks. After 12 weeks of diabetes, both WT and Hsp70 KO mice developed deficits in NCV (nerve conduction velocity and a sensory hypoalgesia. Although KU-32 did not improve glucose levels, HbA1c (glycated haemoglobin or insulin levels, it reversed the NCV and sensory deficits in WT but not Hsp70 KO mice. These studies provide the first evidence that targeting molecular chaperones reverses the sensory hypoalgesia associated with DPN.

Direct Renin Inhibition with Aliskiren Improves Ischemia-Induced Neovasculogenesis in Diabetic Animals via the SDF-1 Related Mechanism.

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Ting-Ting Chang

Full Text Available Aliskiren is a direct renin inhibitor which is suggested to modify proangiogenic cells in addition to lower blood pressure. Given that angiogenesis is impaired in the presence of diabetes mellitus, we would like to investigate whether and how aliskiren enhances endothelial progenitor cells (EPCs and improves ischemic-induced neovasculogenesis by an effect independent of blood pressure reduction in diabetic animals.Streptozotocin-induced diabetic mice were administered with either aliskiren (5 or 25 mg/kg/day using an osmotic pump or hydralazine (2 or 10 mg/kg/day given in drinking water for two weeks prior to a hind-limb ischemia surgery. Laser Doppler imaging and flow cytometry were used to evaluate the degree of neovasculogenesis and the circulating levels of EPCs, respectively.In streptozotocin-induced diabetic mice, aliskiren enhanced the recovery of limb perfusion and capillary density, increased the number of circulating Sca-1+/Flk-1+ EPC-like cells, and elevated the levels of the plasma vascular endothelial growth factor (VEGF and stromal cell-derived factor (SDF-1α in a dose-dependent manner, whereas there were no such effects in hydralazine-treated mice. Intraperitoneal administration of anti-SDF-1 neutralizing monoclonal antibodies abolished the effects of aliskiren.Independent of the reduction of blood pressure, aliskiren enhanced ischemia-induced neovasculogenesis in a dose-dependent manner via VEGF/SDF-1α related mechanisms in diabetic mice.

NOX2-Induced Activation of Arginase and Diabetes-Induced Retinal Endothelial Cell Senescence

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Modesto Rojas

2017-06-01

Full Text Available Increases in reactive oxygen species (ROS and decreases in nitric oxide (NO have been linked to vascular dysfunction during diabetic retinopathy (DR. Diabetes can reduce NO by increasing ROS and by increasing activity of arginase, which competes with nitric oxide synthase (NOS for their commons substrate l-arginine. Increased ROS and decreased NO can cause premature endothelial cell (EC senescence leading to defective vascular repair. We have previously demonstrated the involvement of NADPH oxidase 2 (NOX2-derived ROS, decreased NO and overactive arginase in DR. Here, we investigated their impact on diabetes-induced EC senescence. Studies using diabetic mice and retinal ECs treated with high glucose or H2O2 showed that increases in ROS formation, elevated arginase expression and activity, and decreased NO formation led to premature EC senescence. NOX2 blockade or arginase inhibition prevented these effects. EC senescence was also increased by inhibition of NOS activity and this was prevented by treatment with a NO donor. These results indicate that diabetes/high glucose-induced activation of arginase and decreases in NO bioavailability accelerate EC senescence. NOX2-generated ROS contribute importantly to this process. Blockade of NOX2 or arginase represents a strategy to prevent diabetes-induced premature EC senescence by preserving NO bioavailability.

Rapamycin-ameliorated diabetic symptoms involved in increasing adiponectin expression in diabetic mice on a high-fat diet.

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Gong, Fang-Hua; Ye, Yan-Na; Li, Jin-Meng; Zhao, Hai-Yang; Li, Xiao-Kun

2017-07-01

Recent studies showed that rapamycin improved diabetic complications. Here, we investigated the metabolic effects of rapamycin in type 2 diabetes model (T2DM) mice. Mice were treated with a daily intraperitoneal injection of rapamycin at 2 mg/kg or vehicle only for 3 weeks and were maintained on a high-fat diet. The treated diabetic mice exhibited decreased body weight, blood glucose levels, and fat mass. FGF21 expression was suppressed in C57B/L6 mice, but adiponectin expression increased both in FGF21 KO and C57B/L6 mice. These results suggest that rapamycin may alleviate FGF21 resistance in mice on a high-fat diet. The reduction of adipose tissue mass of the diabetic mice may be due to the increased adiponectin. Copyright © 2017. Published by Elsevier Taiwan.

Dysregulation of the unfolded protein response in db/db mice with diet induced steatohepatitis

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Rinella, Mary E.; Siddiqui, M. Shaddab; Gardikiotes, Konstantina; Gottstein, Jeanne; Elias, Marc; Green, Richard M.

2011-01-01

In humans with non-alcoholic fatty liver, diabetes is associated with more advanced disease. We have previously shown that diabetic db/db mice are highly susceptible to methionine choline deficient diet (MCD) induced hepatic injury. Since activation of the unfolded protein response (UPR) is an important adaptive cellular mechanism in diabetes, obesity and fatty liver, we hypothesized that dysregulation of the UPR may partially explain how diabetes could promote liver injury.

Spironolactone treatment attenuates vascular dysfunction in type 2 diabetic mice by decreasing oxidative stress and restoring NO/GC signaling

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Marcondes Alves Barbosa Da Silva

2015-10-01

Full Text Available Type 2 diabetes (DM2 increases the risk of cardiovascular disease. Aldosterone, which has pro-oxidative and pro-inflammatory effects in the cardiovascular system, is positively regulated in DM2. We assessed whether blockade of mineralocorticoid receptors (MR with spironolactone decreases ROS-associated vascular dysfunction and improves vascular NO signaling in diabetes. Leptin receptor knockout [LepRdb/LepRdb (db/db] mice, a model of DM2, and their counterpart controls [LepRdb/LepR+, (db/+ mice] received spironolactone (50 mg/kg body weight/day or vehicle (ethanol 1% via oral per gavage for 6 weeks. Spironolactone treatment abolished the endothelial dysfunction and increased endothelial nitric oxide synthase (eNOS phosphorylation (Ser1177, determined by acetylcholine-induced relaxation and Western Blot analysis, respectively. MR antagonist therapy also abrogated augmented ROS-generation in aorta from diabetic mice, determined by lucigenin luminescence assay. Spironolactone treatment increased superoxide dismutase-1 (SOD1 and catalase expression, improved sodium nitroprusside (SNP and BAY 41-2272-induced relaxation, as well as increased soluble guanylyl cyclase (sGC subunit β protein expression in arteries from db/db mice. Our results demonstrate that spironolactone decreases diabetes-associated vascular oxidative stress and prevents vascular dysfunction through processes involving increased expression of antioxidant enzymes and sGC. These findings further elucidate redox-sensitive mechanisms whereby spironolactone protects against vascular injury in diabetes.

Transmaternal bisphenol A exposure accelerates diabetes type 1 development in NOD mice.

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Bodin, Johanna; Bølling, Anette Kocbach; Becher, Rune; Kuper, Frieke; Løvik, Martinus; Nygaard, Unni Cecilie

2014-02-01

Diabetes mellitus type 1 is an autoimmune disease with a genetic predisposition that is triggered by environmental factors during early life. Epidemiological studies show that bisphenol A (BPA), an endocrine disruptor, has been detected in about 90% of all analyzed human urine samples. In this study, BPA was found to increase the severity of insulitis and the incidence of diabetes in female non obese diabetic (NOD) mice offspring after transmaternal exposure through the dams' drinking water (0, 0.1, 1, and 10mg/l). Both the severity of insulitis in the pancreatic islets at 11 weeks of age and the diabetes prevalence at 20 weeks were significantly increased for female offspring in the highest exposure group compared to the control group. Increased numbers of apoptotic cells, a reduction in tissue resident macrophages and an increase in regulatory T cells were observed in islets prior to insulitis development in transmaternally exposed offspring. The detectable apoptotic cells were identified as mostly glucagon producing alpha-cells but also tissue resident macrophages and beta-cells. In the local (pancreatic) lymph node neither regulatory T cell nor NKT cell populations were affected by maternal BPA exposure. Maternal BPA exposure may have induced systemic immune changes in offspring, as evidenced by alterations in LPS- and ConA-induced cytokine secretion in splenocytes. In conclusion, transmaternal BPA exposure, in utero and through lactation, accelerated the spontaneous diabetes development in NOD mice. This acceleration appeared to be related to early life modulatory effects on the immune system, resulting in adverse effects later in life.

Intracavernous Delivery of a Designed Angiopoietin-1 Variant Rescues Erectile Function by Enhancing Endothelial Regeneration in the Streptozotocin-Induced Diabetic Mouse

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Jin, Hai-Rong; Kim, Woo Jean; Song, Jae Sook; Piao, Shuguang; Choi, Min Ji; Tumurbaatar, Munkhbayar; Shin, Sun Hwa; Yin, Guo Nan; Koh, Gou Young; Ryu, Ji-Kan; Suh, Jun-Kyu

2011-01-01

OBJECTIVE Patients with diabetic erectile dysfunction often have severe endothelial dysfunction and respond poorly to oral phosphodiesterase-5 inhibitors. We examined the effectiveness of the potent angiopoietin-1 (Ang1) variant, cartilage oligomeric matrix protein (COMP)-Ang1, in promoting cavernous endothelial regeneration and restoring erectile function in diabetic animals. RESEARCH DESIGN AND METHODS Four groups of mice were used: controls; streptozotocin (STZ)-induced diabetic mice; STZ-induced diabetic mice treated with repeated intracavernous injections of PBS; and STZ-induced diabetic mice treated with COMP-Ang1 protein (days −3 and 0). Two and 4 weeks after treatment, we measured erectile function by electrical stimulation of the cavernous nerve. The penis was harvested for histologic examinations, Western blot analysis, and cGMP quantification. We also performed a vascular permeability test. RESULTS Local delivery of the COMP-Ang1 protein significantly increased cavernous endothelial proliferation, endothelial nitric oxide (NO) synthase (NOS) phosphorylation, and cGMP expression compared with that in the untreated or PBS-treated STZ-induced diabetic group. The changes in the group that received COMP-Ang1 restored erectile function up to 4 weeks after treatment. Endothelial protective effects, such as marked decreases in the expression of p47phox and inducible NOS, in the generation of superoxide anion and nitrotyrosine, and in the number of apoptotic cells in the corpus cavernosum tissue, were noted in COMP-Ang1–treated STZ-induced diabetic mice. An intracavernous injection of COMP-Ang1 completely restored endothelial cell-cell junction proteins and decreased cavernous endothelial permeability. COMP-Ang1–induced promotion of cavernous angiogenesis and erectile function was abolished by the NOS inhibitor, N-nitro-L-arginine methyl ester, but not by the NADPH oxidase inhibitor, apocynin. CONCLUSIONS These findings support the concept of cavernous

Exercise Increases Insulin Content and Basal Secretion in Pancreatic Islets in Type 1 Diabetic Mice

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Han-Hung Huang

2011-01-01

Full Text Available Exercise appears to improve glycemic control for people with type 1 diabetes (T1D. However, the mechanism responsible for this improvement is unknown. We hypothesized that exercise has a direct effect on the insulin-producing islets. Eight-week-old mice were divided into four groups: sedentary diabetic, exercised diabetic, sedentary control, and exercised control. The exercised groups participated in voluntary wheel running for 6 weeks. When compared to the control groups, the islet density, islet diameter, and β-cell proportion per islet were significantly lower in both sedentary and exercised diabetic groups and these alterations were not improved with exercise. The total insulin content and insulin secretion were significantly lower in sedentary diabetics compared to controls. Exercise significantly improved insulin content and insulin secretion in islets in basal conditions. Thus, some improvements in exercise-induced glycemic control in T1D mice may be due to enhancement of insulin content and secretion in islets.

Recovery of Corneal Sensitivity and Increase in Nerve Density and Wound Healing in Diabetic Mice After PEDF Plus DHA Treatment.

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He, Jiucheng; Pham, Thang Luong; Kakazu, Azucena; Bazan, Haydee E P

2017-09-01

Diabetic keratopathy decreases corneal sensation and tear secretion and delays wound healing after injury. In the current study, we tested the effect of treatment with pigment epithelium-derived factor (PEDF) in combination with docosahexaenoic acid (DHA) on corneal nerve regeneration in a mouse model of diabetes with or without corneal injury. The study was performed in streptozotocin-induced diabetic mice (C57BL/6). Ten weeks after streptozotocin injection, diabetic mice showed significant decreases of corneal sensitivity, tear production, and epithelial subbasal nerve density when compared with age-matched normal mice. After diabetic mice were wounded in the right eye and treated in both eyes with PEDF+DHA for 2 weeks, there was a significant increase in corneal epithelial nerve regeneration and substance P-positive nerve density in both wounded and unwounded eyes compared with vehicle-treated corneas. There also was elevated corneal sensitivity and tear production in the treated corneas compared with vehicle. In addition, PEDF+DHA accelerated corneal wound healing, selectively recruited type 2 macrophages, and prevented neutrophil infiltration in diabetic wounded corneas. These results suggest that topical treatment with PEDF+DHA promotes corneal nerve regeneration and wound healing in diabetic mice and could potentially be exploited as a therapeutic option for the treatment of diabetic keratopathy. © 2017 by the American Diabetes Association.

Circulatory and Renal Consequences of Pregnancy in Diabetic NOD Mice

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Burke, S.D.; Barrette, V.F.; David, S.; Khankin, E. V.; Adams, M.A.; Croy, B.A.

2011-01-01

Objectives Women with diabetes have elevated gestational risks for severe hemodynamic complications, including preeclampsia in mid- to late pregnancy. This study employed continuous, chronic radiotelemetry to compare the hemodynamic patterns in non-obese diabetic (NOD) mice who were overtly diabetic or normoglycemic throughout gestation. We hypothesized that overtly diabetic, pregnant NOD mice would develop gestational hypertension and provide understanding of mechanisms in progression of this pathology. Study Design Telemeter-implanted, age-matched NOD females with and without diabetes were assessed for six hemodynamic parameters (mean, systolic, diastolic, pulse pressures, heart rate and activity) prior to mating, over pregnancy and over a 72 hr post-partum interval. Urinalysis, serum biochemistry and renal histopathology were also conducted. Results Pregnant, normoglycemic NOD mice had a hemodynamic profile similar to other inbred strains, despite insulitis. This pattern was characterized by an interval of pre-implantation stability, post implantation decline in arterial pressure to mid gestation, and then a rebound to pre-pregnancy baseline during later gestation. Overtly diabetic NOD mice had a blood pressure profile that was normal until mid-gestation then become mildly hypotensive (−7mmHg, Ppost-partum (−10% pre-pregnancy pressure and HR, P<0.05). Conclusions Pregnancy accelerates circulatory and renal pathologies in overtly diabetic NOD mice and is characterized by depressed arterial pressure from mid-gestation and birth of growth 45 restricted offspring. PMID:22014504

Fluoride Exposure Aggravates the Testicular Damage and Sperm Quality in Diabetic Mice: Protective Role of Ginseng and Banaba.

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Sm, Saumya; Mahaboob Basha, P

2017-06-01

Fluoride toxicity is known to pose infertility in fluoride-intoxicated animals as well as in people residing in fluoride endemic zones. The present study addresses the degree of impairments caused due to co-exposure of high fluoride toxicity in diabetic mice. Swiss mice, Mus musculus, were subjected to fluoride toxicity by providing fluoride-supplemented drinking water (600 ppm NaF) for a period of 30 days after the confirmation of streptozotocin-induced diabetes(STZ, 50 mg/kgbw). Consequently, aggravated hyperglycemia and tissue fluoride accumulation were witnessed in fluoride-intoxicated diabetic mice; later, these toxicated mice were treated with ginseng extract (GE) and banaba leaf extract, (BLE) at dose of 150 mg/kgbw/day alone and in combination for 15 and 30-day duration to check the efficacy of phytoextracts in reversing the toxicity. The spermatological indices studied, such as sperm density, motility, viability and morphology as well as the testicular biochemical parameters showed enhanced impairment in reproductive status of fluoride-intoxicated diabetic mice. Further, 15-days administration of GE and BLE in combination at a dose of 150 mg/kgbw/day was found to be beneficial in normalizing the alterations observed upon fluoride intoxication to diabetic mice. However, the correlates showed moderate association between blood glucose levels and the spermatological as well as biochemical indices wherein the tissue fluoride levels correlate least.

Use of acetazolamide in lithium-induced nephrogenic diabetes insipidus: a case report.

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Macau, Ricardo A; da Silva, Tiago Nunes; Silva, Joana Rego; Ferreira, Ana Gonçalves; Bravo, Pedro

2018-01-01

Lithium-induced nephrogenic diabetes insipidus (Li-NDI) is a rare and difficult-to-treat condition. A study in mice and two recent papers describe the use of acetazolamide in Li-NDI in 7 patients (a case report and a 6 patient series). We describe the case of a 63-year-old woman with bipolar disorder treated with lithium and no previous history of diabetes insipidus. She was hospitalized due to a bowel obstruction and developed severe dehydration after surgery when she was water deprived. After desmopressin administration and unsuccessful thiazide and amiloride treatment, acetazolamide was administrated to control polyuria and hydroelectrolytic disorders without significant side effects. To our knowledge, this is the third publication on acetazolamide use in Li-NDI patients. Treatment of lithium-induced nephrogenic diabetes insipidus might be challenging.Vasopressin, amiloride and thiazide diuretics have been used in lithium-induced nephrogenic diabetes insipidus treatment.Acetazolamide might be an option to treat lithium-induced nephrogenic diabetes insipidus patients who fail to respond to standard treatment.The use of acetazolamide in lithium-induced nephrogenic diabetes insipidus must be monitored, including its effects on glomerular filtration rate.

Diabetes-induced microvascular complications at the level of the spinal cord; a contributing factor in diabetic neuropathic pain.

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Ved, N; Da Vitoria Lobo, M E; Bestall, S M; L Vidueira, C; Beazley-Long, N; Ballmer-Hofer, K; Hirashima, M; Bates, D O; Donaldson, L F; Hulse, R P

2018-05-17

Abnormalities of neurovascular interactions within the central nervous system of diabetic patients is associated with the onset of many neurological disease states. However, to date, the link between the neurovascular network within the spinal cord and regulation of nociception has not been investigated despite neuropathic pain being common in diabetes. We hypothesised that hyperglycaemia-induced endothelial degeneration in the spinal cord, due to suppression of VEGF-A/VEGFR2 signalling, induces diabetic neuropathic pain. Nociceptive pain behaviour was investigated in a chemically induced model of type 1 diabetes (streptozotocin induced, insulin supplemented; either vehicle or VEGF-A 165 b treated) and an inducible endothelial knockdown of VEGFR2 (tamoxifen induced). Diabetic animals developed mechanical allodynia and heat hyperalgesia. This was associated with a reduction in the number of blood vessels and reduction in Evans blue extravasation in the lumbar spinal cord of diabetic animals versus age-matched controls. Endothelial markers occludin, CD31 and VE-cadherin were downregulated in the spinal cord of the diabetic group versus controls, as well as a concurrent reduction of VEGF-A 165 b expression. In diabetic animals, VEGF-A 165 b treatment (biweekly intraperitoneal, 20 ng g -1 ) restored normal Evans blue extravasation and prevented vascular degeneration, diabetes-induced central neuron activation and neuropathic pain. Inducible knockdown of VEGFR2 (tamoxifen treated Tie2CreER T2 -vegfr2 flfl mice) led to a reduction in blood vessel network volume in the lumbar spinal cord and development of heat hyperalgesia. These findings indicate that hyperglycaemia leads to a reduction in the VEGF-A/VEGFR2 signalling cascade resulting in endothelial dysfunction in the spinal cord, which could be an undiscovered contributing factor to diabetic neuropathic pain. This article is protected by copyright. All rights reserved. This article is protected by copyright. All

Effects of Averrhoa carambola L. (Oxalidaceae) juice mediated on hyperglycemia, hyperlipidemia, and its influence on regulatory protein expression in the injured kidneys of streptozotocin-induced diabetic mice.

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Pham, Hoa Thi Thai; Huang, Wansu; Han, Chuangye; Li, Juman; Xie, Qiuqiao; Wei, Jinbin; Xu, Xiaohui; Lai, Zefeng; Huang, Xiang; Huang, Renbin; Wen, Qingwei

2017-01-01

Recently, many reports have shown that Averrhoa carambola L. (Oxalidaceae) juice (EACJ) could reduce blood glucose in humans. However, its mechanisms have not been well explored; therefore, our study aimed to investigate the beneficial effects of EACJ on hyperglycemia, hyperlipidemia and renal injury in streptozotocin (STZ)-induced diabetic mice. Those mice were injected with STZ via the tail vein (120 mg/kg body weight) and were identified as diabetic mice when the level of blood glucose was ≥ 11.1 mmol/L. Those mice were intragastriced gavage with saline, EACJ (25, 50, 100 g/kg body weight/d) and metformin (320 mg/kg body weight/d) for 21 days. The fasting blood glucose (FBG), free fatty acids (FFA), total cholesterol (TC), triglycerides (TG), Scr (CREA) and blood urea nitrogen (BUN) were significantly decreased, while the sorbitol dehydrogenase (SDH), Cyclic Adenosine monophosphate (cAMP), malondialdehyde (MDA), superoxide dismutase (SOD), and insulin were elevated. Diabetes-dependent alterations in the kidney, such as glomerular hypertrophy, thicken and tubular basement membrane, were improved after 21 days of EACJ treatment. Hyperglycemia, renal formation and the expressions of related proteins such as connective tissue growth factor (CTGF) and transforming growth factor beta 1 (TGF-β1) were markedly decreased by EACJ. These results indicate that EACJ treatment decrease hyperglycemia, hyperlipidemia and inhibit the progression of diabetic nephropathy (DN), which may be linked to regulating several pharmacological targets for treating or preventing DN.

Effects of Chimonanthus nitens Oliv. Leaf Extract on Glycolipid Metabolism and Antioxidant Capacity in Diabetic Model Mice

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Hui Chen

2017-01-01

Full Text Available The paper investigated the antihyperglycemic and antihyperlipidemic efficacy and antioxidant capacity of Chimonanthus nitens Oliv. leaf extract (COE in combination of high-glucose-fat diet-fed and streptozotocin-induced diabetic model mice. Various physiological indexes in diabetic model mice were well improved especially by oral administration of high dose of COE; the results were listed as follows. Fast blood glucose (FBG level and serum triglyceride (TC, total cholesterol (TG, low-density lipoprotein cholesterol (LDLC, and malondialdehyde (MDA as well as MDA in liver were significantly reduced; fasting serum insulin (FINS and insulin sensitivity index (ISI were both increased; high-density lipoprotein cholesterol (HDLC in serum was significantly increased; total antioxidant capacity (T-AOC, activities of superoxide dismutase (SOD, glutathione peroxidase (GSH-Px, and catalase (CAT in serum and liver were apparently enhanced; liver coefficient (LC, liver transaminase, and alkaline phosphatase (ALP were decreased. Furthermore, pancreas islets and liver in diabetic model mice showed some extend of improvement in morphology and function after 4 weeks of COE treatment. In consequence, COE was advantageous to regulate glycolipid metabolism and elevate antioxidant capacity in diabetic model mice. Thus, the present study will provide a scientific evidence for the use of COE in the management of diabetes and its related complications.

ß-cell specific overexpression of suppressor of cytokine signalling-3 does not protect against multiple low dose streptozotocin induced type 1 diabetes in mice

DEFF Research Database (Denmark)

Börjesson, A; Rønn, S G; Karlsen, A E

2011-01-01

We investigated the impact of ß-cell specific overexpression of suppressor of cytokine signalling-3 (SOCS-3) on the development of multiple low dose streptozotocin (MLDSTZ) induced Type 1 diabetes and the possible mechanisms involved. MLDSTZ treatment was administered to RIP-SOCS-3 transgenic......RNA in islet cells and secretion of IL-1Ra into culture medium. MLDSTZ treatment caused gradual hyperglycemia both in the wt mice and in the transgenic mice with the latter tending to be more sensitive. In vitro experiments on wt and transgenic islets did not reveal any differences in sensitivity to damaging...

Effect of tocotrienol on aortic atherosclerosis in diabetic mice

International Nuclear Information System (INIS)

Kiani, M.R.B.; Butt, S.A.; Ahmed, T.

2015-01-01

Effect of tocotrienol on aortic atherosclerosis in diabetic mice To study the histomorphological effect of tocotrienol on aortic atherosclerosis in diabetic mice having high fat diet. Study Design: Lab based randomized controlled trial. Place and Duration of Study: Army Medical College, Rawalpindi and National Institute of Health, Islamabad from November 2009 to June 2010. Material and Methods: Forty five female BALB/c mice were randomly divided into three groups. The diabetic mice model was established by intraperitoneal injection of streptozotocin (STZ) 40 mg/kg body weight. Group A was given normal laboratory diet, group B high fat diet and group C was given tocotrienol along with high fat diet for 32 weeks. At the end of experiment the mice were sacrificed. The hearts of animals were dissected out and ascending aortae were taken out. The specimen was fixed in 10% formol calcium and processed for paraffin embedding. Five micrometer thick sections were made for haematoxylin and eosin, and Verhoeff's staining. After staining, histomorphologic changes in slides were noted. Results: In contrast to group A, atheroscelrosis developed in groups B and C. Statistically significant atherosclerotic changes were found in the aortae of diabetic mice in group B when compared to group A. On comparison of group A to C, atherosclerotic changes were statistically insignificant. However when group B was compared with group C, the aortic atherosclerotic changes decreased significantly in group C. Conclusion: In diabetics with high fat diet intake, there is an increase in development of atherosclerosis in aorta which can be reduced by tocotrienol. (author)

Nuclear factor erythroid 2-related factor 2 deletion impairs glucose tolerance and exacerbates hyperglycemia in type 1 diabetic mice.

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Aleksunes, Lauren M; Reisman, Scott A; Yeager, Ronnie L; Goedken, Michael J; Klaassen, Curtis D

2010-04-01

The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) induces a battery of cytoprotective genes after oxidative stress. Nrf2 aids in liver regeneration by altering insulin signaling; however, whether Nrf2 participates in hepatic glucose homeostasis is unknown. Compared with wild-type mice, mice lacking Nrf2 (Nrf2-null) have lower basal serum insulin and prolonged hyperglycemia in response to an intraperitoneal glucose challenge. In the present study, blood glucose, serum insulin, urine flow rate, and hepatic expression of glucose-related genes were quantified in male diabetic wild-type and Nrf2-null mice. Type 1 diabetes was induced with a single intraperitoneal dose (200 mg/kg) of streptozotocin (STZ). Histopathology and serum insulin levels confirmed depleted pancreatic beta-cells in STZ-treated mice of both genotypes. Five days after STZ, Nrf2-null mice had higher blood glucose levels than wild-type mice. Nine days after STZ, polyuria occurred in both genotypes with more urine output from Nrf2-null mice (11-fold) than wild-type mice (7-fold). Moreover, STZ-treated Nrf2-null mice had higher levels of serum beta-hydroxybutyrate, triglycerides, and fatty acids 10 days after STZ compared with wild-type mice. STZ reduced hepatic glycogen in both genotypes, with less observed in Nrf2-null mice. Increased urine output and blood glucose in STZ-treated Nrf2-null mice corresponded with enhanced gluconeogenesis (glucose-6-phosphatase and phosphoenolpyruvate carboxykinase)- and reduced glycolysis (pyruvate kinase)-related mRNA expression in their livers. Furthermore, the Nrf2 activator oltipraz lowered blood glucose in wild-type but not Nrf2-null mice administered STZ. Collectively, these data indicate that the absence of Nrf2 worsens hyperglycemia in type I diabetic mice and Nrf2 may represent a therapeutic target for reducing circulating glucose levels.

Hypoglycemic Effect of Aqueous and Methanolic Extract of Artemisia afra on Alloxan Induced Diabetic Swiss Albino Mice

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Idris Ahmed Issa

2015-01-01

Full Text Available Diabetes mellitus is metabolic syndrome that causes disability, early death, and many other complications. Currently insulin and many synthetic drugs are used in diabetes treatment. However, these pharmaceutical drugs are too expensive particularly for sub-Saharan population in addition to their undesirable side effects. The present study was aimed to evaluate antidiabetic effect and toxicity level of Artemisia afra which was collected from its natural habitat in Bale Zone, around Goba town, 455 km southeast of Addis Ababa. Air dried aerial parts of Artemisia afra were separately extracted with both distilled water and 95% methanol. Oral acute toxicity test was conducted on healthy Swiss albino mice. Antidiabetic effect of the aqueous and methanolic extracts of Artemisia afra was separately evaluated on alloxan induced diabetic mice at doses of 500, 750, and 1000 mg/Kg body weight orally. The results indicate that mean lethal dose (LD50 for aqueous extract of Artemisia afra was 9833.4 mg/Kg. Blood glucose level was significantly decreased by 24% (p<0.005 and 56.9% (p<0.0004 in groups that received aqueous extract of Artemisia afra at dose of 500 mg/Kg and 750 mg/Kg, respectively. The methanolic extract of Artemisia afra also significantly lowered blood glucose by 49.8% (p<0.0001 at doses of 1000 mg/kg on the 5th hr. Aqueous extract of Artemisia afra was regarded as nontoxic and safe since its LD50 was found above 5000 mg/Kg. Aqueous extract showed higher effect at relatively lower dose as compared to methanolic extract. The aqueous extract was screened positive for phytochemicals like flavonoids, polyphenols, and tannins that were reported to have antioxidant activity.

Overexpression of PTPN2 in Visceral Adipose Tissue Ameliorated Atherosclerosis via T Cells Polarization Shift in Diabetic Apoe-/- Mice

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Ya Li

2018-03-01

Full Text Available Background/Aims: Dysregulated inflammation in adipose tissue, marked by increased pro-inflammatory T-cell accumulation and reduced regulatory T cells (Treg, contributes to diabetes-associated insulin resistance and atherosclerosis. However, the molecular mechanisms underlying T-cell-mediated inflammation in adipose tissue remain largely unknown. Methods: Sixty apolipoprotein E (ApoE-/- mice were randomly divided into chow and diabetes groups. Diabetes was induced by a high-fat and high-sugar diet combined with low-dose streptozotocin. Then we transferred a recombinant adenovirus carrying the protein tyrosine phosphatase non-receptor type 2 (PTPN2 gene into epididymal white adipose tissue (EWAT of ApoE-/- mice. After transfection, all mice were euthanized to evaluate the effects of PTPN2 on T cells polarization and atherosclerosis. Results: PTPN2 was downregulated in EWAT of diabetic ApoE-/- mice. PTPN2 overexpression in EWAT reversed the high Th1/Treg and Th17/Treg ratios in EWAT of diabetic mice. In addition, PTPN2 overexpression in EWAT could significantly reduce macrophages infiltration, the ratio of M1/M2 macrophages and the expression of pro-inflammatory cytokines in EWAT, improving insulin resistance. In aortic root lesions, the vulnerability index were significantly decreased by overexpression of PTPN2 in EWAT. Conclusion: These data suggested that PTPN2 overexpression in EWAT would inhibit systemic inflammation and increase the plaque stability via T cells polarization shift in diabetic mice.

Histidine Decarboxylase Deficiency Prevents Autoimmune Diabetes in NOD Mice

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Manal Alkan

2015-01-01

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

Antioxidant rich grape pomace extract suppresses postprandial hyperglycemia in diabetic mice by specifically inhibiting alpha-glucosidase

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Hogan Shelly

2010-08-01

Full Text Available Abstract Background Postprandial hyperglycemia is an early defect of type 2 diabetes and one of primary anti-diabetic targets. Treatment of postprandial hyperglycemia can be achieved by inhibiting intestinal α-glucosidase, the key enzyme for oligosaccharide digestion and further glucose absorption. Grape pomace is winemaking byproduct rich in bioactive food compounds such as phenolic antioxidants. This study evaluated the anti-diabetic potential of two specific grape pomace extracts by determining their antioxidant and anti-postprandial hyperglycemic activities in vitro and in vivo. Methods The extracts of red wine grape pomace (Cabernet Franc and white wine grape pomace (Chardonnay were prepared in 80% ethanol. An extract of red apple pomace was included as a comparison. The radical scavenging activities and phenolic profiles of the pomace extracts were determined through the measurement of oxygen radical absorbance capacity, DPPH radical scavenging activity, total phenolic content and flavonoids. The inhibitory effects of the pomace extracts on yeast and rat intestinal α-glucosidases were determined. Male 6-week old C57BLKS/6NCr mice were treated with streptozocin to induce diabetes. The diabetic mice were then treated with vehicle or the grape pomace extract to determine whether the oral intake of the extract can suppress postprandial hyperglycemia through the inhibition of intestinal α-glucosidases. Results The red grape pomace extract contained significantly higher amounts of flavonoids and phenolic compounds and exerted stronger oxygen radical absorbance capacity than the red apple pomace extract. Both the grape pomace extracts but not the apple pomace extract exerted significant inhibition on intestinal α-glucosidases and the inhibition appears to be specific. In the animal study, the oral intake of the grape pomace extract (400 mg/kg body weight significantly suppressed the postprandial hyperglycemia by 35% in streptozocin-induced

Antioxidant rich grape pomace extract suppresses postprandial hyperglycemia in diabetic mice by specifically inhibiting alpha-glucosidase.

Science.gov (United States)

Hogan, Shelly; Zhang, Lei; Li, Jianrong; Sun, Shi; Canning, Corene; Zhou, Kequan

2010-08-27

Postprandial hyperglycemia is an early defect of type 2 diabetes and one of primary anti-diabetic targets. Treatment of postprandial hyperglycemia can be achieved by inhibiting intestinal α-glucosidase, the key enzyme for oligosaccharide digestion and further glucose absorption. Grape pomace is winemaking byproduct rich in bioactive food compounds such as phenolic antioxidants. This study evaluated the anti-diabetic potential of two specific grape pomace extracts by determining their antioxidant and anti-postprandial hyperglycemic activities in vitro and in vivo. The extracts of red wine grape pomace (Cabernet Franc) and white wine grape pomace (Chardonnay) were prepared in 80% ethanol. An extract of red apple pomace was included as a comparison. The radical scavenging activities and phenolic profiles of the pomace extracts were determined through the measurement of oxygen radical absorbance capacity, DPPH radical scavenging activity, total phenolic content and flavonoids. The inhibitory effects of the pomace extracts on yeast and rat intestinal α-glucosidases were determined. Male 6-week old C57BLKS/6NCr mice were treated with streptozocin to induce diabetes. The diabetic mice were then treated with vehicle or the grape pomace extract to determine whether the oral intake of the extract can suppress postprandial hyperglycemia through the inhibition of intestinal α-glucosidases. The red grape pomace extract contained significantly higher amounts of flavonoids and phenolic compounds and exerted stronger oxygen radical absorbance capacity than the red apple pomace extract. Both the grape pomace extracts but not the apple pomace extract exerted significant inhibition on intestinal α-glucosidases and the inhibition appears to be specific. In the animal study, the oral intake of the grape pomace extract (400 mg/kg body weight) significantly suppressed the postprandial hyperglycemia by 35% in streptozocin-induced diabetic mice following starch challenge. This is the

Lamp-2 deficiency prevents high-fat diet-induced obese diabetes via enhancing energy expenditure

International Nuclear Information System (INIS)

Yasuda-Yamahara, Mako; Kume, Shinji; Yamahara, Kosuke; Nakazawa, Jun; Chin-Kanasaki, Masami; Araki, Hisazumi; Araki, Shin-ichi; Koya, Daisuke; Haneda, Masakzu; Ugi, Satoshi; Maegawa, Hiroshi; Uzu, Takashi

2015-01-01

Autophagy process is essential for maintaining intracellular homeostasis and consists of autophagosome formation and subsequent fusion with lysosome for degradation. Although the role of autophagosome formation in the pathogenesis of diabetes has been recently documented, the role of the latter process remains unclear. This study analyzed high-fat diet (HFD)-fed mice lacking lysosome-associated membrane protein-2 (lamp-2), which is essential for the fusion with lysosome and subsequent degradation of autophagosomes. Although lamp-2 deficient mice showed little alteration in glucose metabolism under normal diet feeding, they showed a resistance against high-fat diet (HFD)-induced obesity, hyperinsulinemic hyperglycemia and tissues lipid accumulation, accompanied with higher energy expenditure. The expression levels of thermogenic genes in brown adipose tissue were significantly increased in HFD-fed lamp-2-deficient mice. Of some serum factors related to energy expenditure, the serum level of fibroblast growth factor (FGF) 21 and its mRNA expression level in the liver were significantly higher in HFD-fed lamp-2-deficient mice in an ER stress-, but not PPARα-, dependent manner. In conclusion, a lamp-2-depenedent fusion and degradation process of autophagosomes is involved in the pathogenesis of obese diabetes, providing a novel insight into autophagy and diabetes. - Highlights: • Lamp-2 is essential for autophagosome fusion with lysosome and its degradation. • Lamp-2 deficiency lead to a resistance to diet-induced obese diabetes in mice. • Lamp-2 deficiency increased whole body energy expenditure under HFD-feeding. • Lamp-2 deficiency elevated the serum level of FGF21 under HFD-feeding

Lamp-2 deficiency prevents high-fat diet-induced obese diabetes via enhancing energy expenditure

Energy Technology Data Exchange (ETDEWEB)

Yasuda-Yamahara, Mako [Department of Medicine, Shiga University of Medical Science, Otsu, Shiga (Japan); Kume, Shinji, E-mail: skume@belle.shiga-med.ac.jp [Department of Medicine, Shiga University of Medical Science, Otsu, Shiga (Japan); Yamahara, Kosuke; Nakazawa, Jun; Chin-Kanasaki, Masami; Araki, Hisazumi; Araki, Shin-ichi [Department of Medicine, Shiga University of Medical Science, Otsu, Shiga (Japan); Koya, Daisuke [Department of Diabetology and Endocrinology, Kanazawa Medical University, Kahoku-Gun, Ishikawa (Japan); Haneda, Masakzu [Division of Metabolism and Biosystemic Science, Asahikawa Medical University, Asahikawa, Hokkaido (Japan); Ugi, Satoshi; Maegawa, Hiroshi; Uzu, Takashi [Department of Medicine, Shiga University of Medical Science, Otsu, Shiga (Japan)

2015-09-18

Autophagy process is essential for maintaining intracellular homeostasis and consists of autophagosome formation and subsequent fusion with lysosome for degradation. Although the role of autophagosome formation in the pathogenesis of diabetes has been recently documented, the role of the latter process remains unclear. This study analyzed high-fat diet (HFD)-fed mice lacking lysosome-associated membrane protein-2 (lamp-2), which is essential for the fusion with lysosome and subsequent degradation of autophagosomes. Although lamp-2 deficient mice showed little alteration in glucose metabolism under normal diet feeding, they showed a resistance against high-fat diet (HFD)-induced obesity, hyperinsulinemic hyperglycemia and tissues lipid accumulation, accompanied with higher energy expenditure. The expression levels of thermogenic genes in brown adipose tissue were significantly increased in HFD-fed lamp-2-deficient mice. Of some serum factors related to energy expenditure, the serum level of fibroblast growth factor (FGF) 21 and its mRNA expression level in the liver were significantly higher in HFD-fed lamp-2-deficient mice in an ER stress-, but not PPARα-, dependent manner. In conclusion, a lamp-2-depenedent fusion and degradation process of autophagosomes is involved in the pathogenesis of obese diabetes, providing a novel insight into autophagy and diabetes. - Highlights: • Lamp-2 is essential for autophagosome fusion with lysosome and its degradation. • Lamp-2 deficiency lead to a resistance to diet-induced obese diabetes in mice. • Lamp-2 deficiency increased whole body energy expenditure under HFD-feeding. • Lamp-2 deficiency elevated the serum level of FGF21 under HFD-feeding.

Activation of α7nAChR Promotes Diabetic Wound Healing by Suppressing AGE-Induced TNF-α Production.

Science.gov (United States)

Dong, Miao-Wu; Li, Ming; Chen, Jie; Fu, Tong-Tong; Lin, Ke-Zhi; Ye, Guang-Hua; Han, Jun-Ge; Feng, Xiang-Ping; Li, Xing-Biao; Yu, Lin-Sheng; Fan, Yan-Yan

2016-04-01

Diabetes frequently presents accumulation of advanced glycation end products (AGEs), which might induce excessive TNF-α production from macrophages to cause impaired wound healing. Recent studies have shown that activation of α7 nicotinic acetylcholine receptor (α7nAChR) on macrophages efficiently suppressed TNF-α synthesis. The aim of this study was to investigate the accumulation of AGEs in the wounds and determine whether PNU282987, an α7nAChR agonist, can improve wound repair by inhibiting AGE-mediated TNF-α production in a streptozotocin (STZ)-induced diabetic mouse model. Animals were assigned into four groups: wounded control group, wounded diabetic group, wounded diabetic group treated intraperitoneally with PNU282987, or wounded diabetic group treated intraperitoneally with vehicle. Compared with the non-diabetic control mice, the diabetic mice exhibited delayed wound healing that was characterized by elevated accumulation of AGEs, increased TNF-α level and macrophage infiltration, and decreased fibroblast number and collagen deposition at the late stage of repair. Besides, macrophages of diabetic wounds showed expression of α7nAChR. During late repair, PNU282987 treatment of diabetic mice significantly reduced the level of TNF-α, accelerated wound healing, and elevated fibroblast number and collagen deposition. To investigate the cellular mechanism of these observations, RAW 264.7 cells, a macrophage cell line, were incubated with AGEs in the presence or absence of PNU282987. TNF-α production from AGE-stimulated macrophages was significantly decreased by PNU282987 in a dose-dependent manner. Furthermore, PNU282987 significantly inhibited AGE-induced nuclear factor-κB (NF-κB) activation and receptor for AGE (RAGE) expression. These results strongly suggest that activating α7nAChR can promote diabetic wound healing by suppressing AGE-induced TNF-α production, which may be closely associated with the blockage of NF-κB activation in macrophages.

Albumin stimulates renal tubular inflammation through an HSP70-TLR4 axis in mice with early diabetic nephropathy

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Jheng, Huei-Fen; Tsai, Pei-Jane; Chuang, Yi-Lun; Shen, Yi-Ting; Tai, Ting-An; Chen, Wen-Chung; Chou, Chuan-Kai; Ho, Li-Chun; Tang, Ming-Jer; Lai, Kuei-Tai A.; Sung, Junne-Ming; Tsai, Yau-Sheng

2015-01-01

ABSTRACT Increased urinary albumin excretion is not simply an aftermath of glomerular injury, but is also involved in the progression of diabetic nephropathy (DN). Whereas Toll-like receptors (TLRs) are incriminated in the renal inflammation of DN, whether and how albumin is involved in the TLR-related renal inflammatory response remains to be clarified. Here, we showed that both TLR2 and TLR4, one of their putative endogenous ligands [heat shock protein 70 (HSP70)] and nuclear factor-κB promoter activity were markedly elevated in the kidneys of diabetic mice. A deficiency of TLR4 but not of TLR2 alleviated albuminuria, tubulointerstitial fibrosis and inflammation induced by diabetes. The protection against renal injury in diabetic Tlr4−/− mice was associated with reduced tubular injuries and preserved cubilin levels, rather than amelioration of glomerular lesions. In vitro studies revealed that albumin, a stronger inducer than high glucose (HG), induced the release of HSP70 from proximal tubular cells. HSP70 blockade ameliorated albumin-induced inflammatory mediators. HSP70 triggered the production of inflammatory mediators in a TLR4-dependent manner. Moreover, HSP70 inhibition in vivo ameliorated diabetes-induced albuminuria, inflammatory response and tubular injury. Finally, we found that individuals with DN had higher levels of TLR4 and HSP70 in the dilated tubules than non-diabetic controls. Thus, activation of the HSP70-TLR4 axis, stimulated at least in part by albumin, in the tubular cell is a newly identified mechanism associated with induction of tubulointerstitial inflammation and aggravation of pre-existing microalbuminuria in the progression of DN. PMID:26398934

Human fibrocyte-derived exosomes accelerate wound healing in genetically diabetic mice

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Geiger, Adolf, E-mail: ageiger@dreirosen-pharma.com; Walker, Audrey, E-mail: awalker@dreirosen-pharma.com; Nissen, Erwin, E-mail: enissen@dreirosen-pharma.com

2015-11-13

Diabetic ulcers represent a substantial societal and healthcare burden worldwide and scarcely respond to current treatment strategies. This study was addressed to evaluate the therapeutic potential of exosomes secreted by human circulating fibrocytes, a population of mesenchymal progenitors involved in normal wound healing via paracrine signaling. The exosomes released from cells sequentially stimulated with platelet-derived growth factor-BB and transforming growth factor-β1, in the presence of fibroblast growth factor 2, did not show potential immunogenicity. These exosomes exhibited in-vitro proangiogenic properties, activated diabetic dermal fibroblasts, induced the migration and proliferation of diabetic keratinocytes, and accelerated wound closure in diabetic mice in vivo. Important components of the exosomal cargo were heat shock protein-90α, total and activated signal transducer and activator of transcription 3, proangiogenic (miR-126, miR-130a, miR-132) and anti-inflammatory (miR124a, miR-125b) microRNAs, and a microRNA regulating collagen deposition (miR-21). This proof-of-concept study demonstrates the feasibility of the use of fibrocytes-derived exosomes for the treatment of diabetic ulcers. - Highlights: • Fibrocytes have shown potent wound healing properties in vitro and in vivo. • Their clinical use is precluded by low numbers and antigen-presenting function. • We isolated exosomes with no immunogenicity potential from human fibrocytes. • Their cargo included microRNAs and proteins that are known healing promoters. • They accelerated wound closure in diabetic mice in a dose-dependent manner.

Diabetes preventive gluten-free diet decreases the number of caecal bacteria in non-obese diabetic mice

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Hansen, Axel Kornerup; Ling, Fenjung; Anne, Kaas

2006-01-01

disease prevention. Methods Two groups of NOD mice from the age of 3 weeks were fed either a gluten-free diet or a standard diet. Each diabetic mouse, when diagnosed, along with a non-diabetic mouse from the same diet group and two nondiabetic mice from the alternate diet group were euthanized and sampled...... qualitatively and quantitatively substantially altered the composition of the caecal bacterial flora in NOD mice. Although Gram-positive bacteria might influence the beta cells through certain digestive products, it is more likely to assume that any effect on diabetes incidence is immunological. Copyright (c...

Immune cell-derived c3 is required for autoimmune diabetes induced by multiple low doses of streptozotocin.

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Lin, Marvin; Yin, Na; Murphy, Barbara; Medof, M Edward; Segerer, Stephan; Heeger, Peter S; Schröppel, Bernd

2010-09-01

The complement system contributes to autoimmune injury, but its involvement in promoting the development of autoimmune diabetes is unknown. In this study, our goal was to ascertain the role of complement C3 in autoimmune diabetes. Susceptibility to diabetes development after multiple low-dose streptozotocin treatment in wild-type (WT) and C3-deficient mice was analyzed. Bone marrow chimeras, luminex, and quantitative reverse transcription PCR assays were performed to evaluate the phenotypic and immunologic impact of C3 in the development of this diabetes model. Coincident with the induced elevations in blood glucose levels, we documented alternative pathway complement component gene expression within the islets of the diabetic WT mice. When we repeated the experiments with C3-deficient mice, we observed complete resistance to disease, as assessed by the absence of histologic insulitis and the absence of T-cell reactivity to islet antigens. Studies of WT chimeras bearing C3-deficient bone marrow cells showed that bone marrow cell-derived C3, and not serum C3, is involved in the induction of diabetes in this model. The data reveal a key role for immune cell-derived C3 in the pathogenesis of murine multiple low-dose streptozotocin-induced diabetes and support the concept that immune cell mediated diabetes is in part complement-dependent.

Dysregulated LIF-STAT3 pathway is responsible for impaired embryo implantation in a Streptozotocin-induced diabetic mouse model

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Tong-Song Wang

2015-07-01

Full Text Available The prevalence of diabetes is increasing worldwide with the trend of patients being young and creating a significant burden on health systems, including reproductive problems, but the effects of diabetes on embryo implantation are still poorly understood. Our study was to examine effects of diabetes on mouse embryo implantation, providing experimental basis for treating diabetes and its complications. Streptozotocin (STZ was applied to induce type 1 diabetes from day 2 of pregnancy or pseudopregnancy in mice. Embryo transfer was used to analyze effects of uterine environment on embryo implantation. Our results revealed that the implantation rate is significantly reduced in diabetic mice compared to controls, and the change of uterine environment is the main reason leading to the decreased implantation rate. Compared to control, the levels of LIF and p-STAT3 are significantly decreased in diabetic mice on day 4 of pregnancy, and serum estrogen level is significantly higher. Estrogen stimulates LIF expression under physiological level, but the excessive estrogen inhibits LIF expression. LIF, progesterone or insulin supplement can rescue embryo implantation in diabetic mice. Our data indicated that the dysregulated LIF-STAT3 pathway caused by the high level of estrogen results in the impaired implantation in diabetic mice, which can be rescued by LIF, progesterone or insulin supplement.

Evaluation of PMI-5011, an ethanolic extract of Artemisia dracunculus L., on peripheral neuropathy in streptozotocin-diabetic mice.

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Watcho, Pierre; Stavniichuk, Roman; Tane, Pierre; Shevalye, Hanna; Maksimchyk, Yury; Pacher, Pal; Obrosova, Irina G

2011-03-01

We previously reported that PMI-5011, an ethanolic extract of Artemisia dracunculus L., alleviates peripheral neuropathy in high fat diet-fed mice, a model of prediabetes and obesity developing oxidative stress and pro-inflammatory changes in the peripheral nervous system. This study evaluated PMI-5011 on established functional, structural, and biochemical changes associated with Type I diabetic peripheral neuropathy. C57Bl6/J mice with streptozotocin-induced diabetes of a 12-week duration, developed motor and sensory nerve conduction velocity deficits, thermal and mechanical hypoalgesia, tactile allodynia, and intra-epidermal nerve fiber loss. PMI-5011 (500 mg/kg/day for 7 weeks) alleviated diabetes-induced nerve conduction slowing, small sensory nerve fiber dysfunction, and increased intra-epidermal nerve fiber density. PMI-5011 blunted sciatic nerve and spinal cord 12/15-lipoxygenase activation and oxidative-nitrosative stress, without ameliorating hyperglycemia or reducing sciatic nerve sorbitol pathway intermediate accumulation. In conclusion, PMI-5011, a safe and non-toxic botanical extract, may find use in the treatment of diabetic peripheral neuropathy.

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

International Nuclear Information System (INIS)

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

2006-01-01

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

Overexpression of thioredoxin in islets transduced by a lentiviral vector prolongs graft survival in autoimmune diabetic NOD mice

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Sytwu Huey-Kang

2009-08-01

Full Text Available Abstract Pancreatic islet transplantation is considered an appropriate treatment to achieve insulin independence in type I diabetic patients. However, islet isolation and transplantation-induced oxidative stress and autoimmune-mediated destruction are still the major obstacles to the long-term survival of graft islets in this potential therapy. To protect islet grafts from inflammatory damage and prolong their survival, we transduced islets with an antioxidative gene thioredoxin (TRX using a lentiviral vector before transplantation. We hypothesized that the overexpression of TRX in islets would prolong islet graft survival when transplanted into diabetic non-obese diabetic (NOD mice. Methods Islets were isolated from NOD mice and transduced with lentivirus carrying TRX (Lt-TRX or enhanced green fluorescence protein (Lt-eGFP, respectively. Transduced islets were transplanted under the left kidney capsule of female diabetic NOD mice, and blood glucose concentration was monitored daily after transplantation. The histology of the islet graft was assessed at the end of the study. The protective effect of TRX on islets was investigated. Results The lentiviral vector effectively transduced islets without altering the glucose-stimulating insulin-secretory function of islets. Overexpression of TRX in islets reduced hydrogen peroxide-induced cytotoxicity in vitro. After transplantation into diabetic NOD mice, euglycemia was maintained for significantly longer in Lt-TRX-transduced islets than in Lt-eGFP-transduced islets; the mean graft survival was 18 vs. 6.5 days (n = 9 and 10, respectively, p Conclusion We successfully transduced the TRX gene into islets and demonstrated that these genetically modified grafts are resistant to inflammatory insult and survived longer in diabetic recipients. Our results further support the concept that the reactive oxygen species (ROS scavenger and antiapoptotic functions of TRX are critical to islet survival after

Early initiation of low-level parenteral dextrose induces an accelerated diabetic phenotype in septic C57BL/6J mice.

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Singamsetty, Srikanth; Shah, Faraaz Ali; Guo, Lanping; Watanabe, Yoshio; McDonald, Sherie; Sharma, Rohit; Zhang, Yingze; Alonso, Laura C; O'Donnell, Christopher P; McVerry, Bryan J

2016-01-01

Development of hyperglycemia during sepsis is associated with increased morbidity and mortality. Nutritional support is common practice in the intensive care unit, but the metabolic effects are not well understood. The purpose of this study is to determine the effect of early low-level calorie provision on the development of hyperglycemia in a clinically relevant murine model of sepsis. C57BL/6J mice underwent femoral arterial and venous catheterization followed by cecal ligation and puncture (CLP) or sham surgery and low-dose intravenous dextrose or saline infusion. Blood glucose, plasma insulin, and cytokines were measured after 24 h. Additional septic mice underwent hyperinsulinemic-euglycemic clamps or received intravenous insulin concurrent with dextrose to determine whole-body insulin sensitivity and test the efficacy of insulin to reverse hyperglycemia. Neither dextrose infusion nor CLP alone induced hyperglycemia. Early initiation of low-level dextrose in septic mice produced a variable glycemic response: 49% maintained euglycemia (blood glucose dextrose (∼ 20% daily caloric requirements) precipitated hyperglycemia akin to an acute diabetic phenotype in septic mice characterized by decreased insulin sensitivity, decreased insulin secretion, and an increased inflammatory response.

Polyinosine-polycytidylic acid promotes excessive iodine intake induced thyroiditis in non-obese diabetic mice via Toll-like receptor 3 mediated inflammation.

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Shi, Ya-nan; Liu, Feng-hua; Yu, Xiu-jie; Liu, Ze-bing; Li, Qing-xin; Yuan, Ji-hong; Zang, Xiao-yi; Li, Lan-ying

2013-02-01

Excessive iodine intake and viral infection are recognized as both critical factors associated with autoimmune thyroid diseases. Toll-like receptors (TLRs) have been reported to play an important role in autoimmune and inflammatory disorders. In this study, we aimed to clarify the possible mechanism of TLR3 involved in polyinosine-polycytidylic acid (poly(I:C)) promoting excessive iodine intake induced thyroiditis in non-obese diabetic (NOD) mice. Both NOD and BALB/c mice were randomly assigned to four groups: control group (n = 5), high iodine intake (HI) group (n = 7), poly(I:C) group (n = 7) and combination of excessive iodine and poly(I:C) injection (HIP) group (n = 7). After 8 weeks, mice were weighed and blood samples were collected. All the mice were sacrificed before dissection of spleen and thyroid gland. Then, thyroid histology, thyroid secreted hormone, expression of CD3(+) cells and TLR3 as well as inflammatory mRNA level were evaluated. Both NOD and BALB/c mice from HI and HIP group represented goiter and increasing thyroid relative weight. Thyroid histology evidence indicated that only HIP group of NOD mice showed severe thyroiditis with lymphocytes infiltration in majority of thyroid tissue, severe damage of follicles and general fibrosis. Immunofluorescence staining results displayed a large number of CD3(+) cells in HIP NOD mice. Real-time polymerase chain reaction (PCR) results suggested interferon (IFN)-α increased over 30 folds and IFN-γ expression was doubled compared with control group, but interleukin (IL)-4 remained unchanged in HIP group of NOD mice thyroid. Meanwhile, over one third decrease of blood total thyroxine (TT4) and increased thyroid-stimulating hormone (TSH) was observed in HIP group of NOD mice. Only HIP group of NOD mice represented significantly elevation of TLR3 expression. Poly(I:C) enhanced excessive dietary iodine induced thyroiditis in NOD mice through increasing TLR3 mediated inflammation.

Hyperglycaemia exacerbates choroidal neovascularisation in mice via the oxidative stress-induced activation of STAT3 signalling in RPE cells.

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Xia Li

Full Text Available Choroidal neovascularisation (CNV that occurs as a result of age-related macular degeneration (AMD causes severe vision loss among elderly patients. The relationship between diabetes and CNV remains controversial. However, oxidative stress plays a critical role in the pathogenesis of both AMD and diabetes. In the present study, we investigated the influence of diabetes on experimentally induced CNV and on the underlying molecular mechanisms of CNV. CNV was induced via photocoagulation in the ocular fundi of mice with streptozotocin-induced diabetes. The effect of diabetes on the severity of CNV was measured. An immunofluorescence technique was used to determine the levels of oxidative DNA damage by anti-8-hydroxy-2-deoxyguanosine (8-OHdG antibody, the protein expression of phosphorylated signal transducer and activator of transcription 3 (p-STAT3 and vascular endothelial growth factor (VEGF, in mice with CNV. The production of reactive oxygen species (ROS in retinal pigment epithelial (RPE cells that had been cultured under high glucose was quantitated using the 2',7'-dichlorofluorescein diacetate (DCFH-DA method. p-STAT3 expression was examined using Western blot analysis. RT-PCR and ELISA processes were used to detect VEGF expression. Hyperglycaemia exacerbated the development of CNV in mice. Oxidative stress levels and the expression of p-STAT3 and VEGF were highly elevated both in mice and in cultured RPE cells. Treatment with the antioxidant compound N-acetyl-cysteine (NAC rescued the severity of CNV in diabetic mice. NAC also inhibited the overexpression of p-STAT3 and VEGF in CNV and in RPE cells. The JAK-2/STAT3 pathway inhibitor AG490 blocked VEGF expression but had no effect on the production of ROS in vitro. These results suggest that hyperglycaemia promotes the development of CNV by inducing oxidative stress, which in turn activates STAT3 signalling in RPE cells. Antioxidant supplementation helped attenuate the development of CNV

Hypoglycemic effect of methanolic extract of Musa paradisiaca (Musaceae) green fruits in normal and diabetic mice.

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Ojewole, J A O; Adewunmi, C O

2003-01-01

Diabetes mellitus is a debilitating hormonal disorder in which strict glycemic control and prevention of associated complications are of crucial importance. This study was designed to evaluate the hypoglycemic effect of methanolic extract of mature, green fruits of Musa paradisiaca (MEMP) in normal (normoglycemic) and streptozotocin (STZ)-treated, diabetic (hyperglycemic) mice, using chlorpropamide as the reference antidiabetic agent. MEMP (100-800 mg/kg p.o.) induced significant, dose-related (p < 0.05-0.001) reductions in the blood glucose concentrations of both normal and diabetic mice. Chlorpropamide (250 mg/kg p.o.) also produced significant (p < 0.01-0.001) reductions in the blood glucose concentrations of normal and diabetic mice. The results of this experimental study indicate that, in the mammalian model used, MEMP possesses hypoglycemic activity. Although the precise mechanism of the hypoglycemic action of MEMP is still unclear and will have to await further studies, it could be due, at least in part, to stimulation of insulin production and subsequent glucose utilization. Nevertheless, the findings of this experimental animal study indicate that MEMP possesses hypoglycemic activity, and thus lends credence to the suggested folkloric use of the plant in the management and/or control of adult-onset, type-2 diabetic mellitus among the Yoruba-speaking people of South-Western Nigeria.

Recovery from diabetes in neonatal mice after a low-dose streptozotocin treatment

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Kataoka, Masateru; Kawamuro, Yuki; Shiraki, Nobuaki [Department of Stem Cell Biology, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Honjo 2-2-1, Chuo-ku, Kumamoto 860-0811 (Japan); Miki, Rika; Sakano, Daisuke [Department of Stem Cell Biology, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Honjo 2-2-1, Chuo-ku, Kumamoto 860-0811 (Japan); The Global COE Cell Fate Regulation Research and Education Unit, Kumamoto University, Honjo 2-2-1, Chuo-ku, Kumamoto 860-0811 (Japan); Yoshida, Tetsu; Yasukawa, Takanori; Kume, Kazuhiko [Department of Stem Cell Biology, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Honjo 2-2-1, Chuo-ku, Kumamoto 860-0811 (Japan); Kume, Shoen, E-mail: skume@kumamoto-u.ac.jp [Department of Stem Cell Biology, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Honjo 2-2-1, Chuo-ku, Kumamoto 860-0811 (Japan); The Global COE Cell Fate Regulation Research and Education Unit, Kumamoto University, Honjo 2-2-1, Chuo-ku, Kumamoto 860-0811 (Japan)

2013-01-18

Highlights: ► We monitored long-term beta cell regeneration in neonatal mice treated with low dose STZ. ► Low-dose STZ neonatal female mice recovered blood glucose in 150 days. ► Glucose intolerance of the STZ treated mice significantly improved in 150 days. -- Abstract: Administration of streptozotocin (STZ) induces destruction of β-cells and is widely used as an experimental animal model of type I diabetes. In neonatal rat, after low-doses of STZ-mediated destruction of β-cells, β-cells regeneration occurs and reversal of hyperglycemia was observed. However, in neonatal mice, β-cell regeneration seems to occur much slowly compared to that observed in the rat. Here, we described the time dependent quantitative changes in β-cell mass during a spontaneous slow recovery of diabetes induced in a low-dose STZ mice model. We then investigated the underlying mechanisms and analyzed the cell source for the recovery of β-cells. We showed here that postnatal day 7 (P7) female mice treated with 50 mg/kg STZ underwent the destruction of a large proportion of β-cells and developed hyperglycemia. The blood glucose increased gradually and reached a peak level at 500 mg/dl on day 35–50. This was followed by a spontaneous regeneration of β-cells. A reversal of non-fasting blood glucose to the control value was observed within 150 days. However, the mice still showed impaired glucose tolerance on day 150 and day 220, although a significant improvement was observed on day 150. Quantification of the β-cell mass revealed that the β-cell mass increased significantly between day 100 and day 150. On day 150 and day 220, the β-cell mass was approximately 23% and 48.5% of the control, respectively. Of the insulin-positive cells, 10% turned out to be PCNA-positive proliferating cells. Our results demonstrated that, β-cell duplication is one of the cell sources for β-cell regeneration.

Recovery from diabetes in neonatal mice after a low-dose streptozotocin treatment

International Nuclear Information System (INIS)

Kataoka, Masateru; Kawamuro, Yuki; Shiraki, Nobuaki; Miki, Rika; Sakano, Daisuke; Yoshida, Tetsu; Yasukawa, Takanori; Kume, Kazuhiko; Kume, Shoen

2013-01-01

Highlights: ► We monitored long-term beta cell regeneration in neonatal mice treated with low dose STZ. ► Low-dose STZ neonatal female mice recovered blood glucose in 150 days. ► Glucose intolerance of the STZ treated mice significantly improved in 150 days. -- Abstract: Administration of streptozotocin (STZ) induces destruction of β-cells and is widely used as an experimental animal model of type I diabetes. In neonatal rat, after low-doses of STZ-mediated destruction of β-cells, β-cells regeneration occurs and reversal of hyperglycemia was observed. However, in neonatal mice, β-cell regeneration seems to occur much slowly compared to that observed in the rat. Here, we described the time dependent quantitative changes in β-cell mass during a spontaneous slow recovery of diabetes induced in a low-dose STZ mice model. We then investigated the underlying mechanisms and analyzed the cell source for the recovery of β-cells. We showed here that postnatal day 7 (P7) female mice treated with 50 mg/kg STZ underwent the destruction of a large proportion of β-cells and developed hyperglycemia. The blood glucose increased gradually and reached a peak level at 500 mg/dl on day 35–50. This was followed by a spontaneous regeneration of β-cells. A reversal of non-fasting blood glucose to the control value was observed within 150 days. However, the mice still showed impaired glucose tolerance on day 150 and day 220, although a significant improvement was observed on day 150. Quantification of the β-cell mass revealed that the β-cell mass increased significantly between day 100 and day 150. On day 150 and day 220, the β-cell mass was approximately 23% and 48.5% of the control, respectively. Of the insulin-positive cells, 10% turned out to be PCNA-positive proliferating cells. Our results demonstrated that, β-cell duplication is one of the cell sources for β-cell regeneration

Glyoxalase 1 overexpression does not affect atherosclerotic lesion size and severity in ApoE-/- mice with or without diabetes

DEFF Research Database (Denmark)

Hanssen, Nordin M J; Brouwers, Olaf; Gijbels, Marion J

2014-01-01

are higher in rupture-prone plaques. We here investigated whether overexpression of human GLO1 in ApoE(-/-) mice could reduce the development of atherosclerosis. METHODS AND RESULTS: We crossed C57BL/6 ApoE(-/-) mice with C57BL/6 GLO1 overexpressing mice (huGLO1(+/-)) to generate ApoE(-/-) (n = 16) and Apo......E(-/-) huGLO1(+/-) (n = 20) mice. To induce diabetes, we injected a subset with streptozotocin (STZ) to generate diabetic ApoE(-/-) (n = 8) and ApoE(-/-) huGLO1(+/-) (n = 13) mice. All mice were fed chow and sacrificed at 25 weeks of age. The GLO1 activity was three-fold increased in huGLO1(+/-) aorta......, but aortic root lesion size and phenotype did not differ between mice with and without huGLO1(+/-) overexpression. We detected no differences in gene expression in aortic arches, in AGE levels and cytokines, in circulating cells, and endothelial function between ApoE(-/-) mice with and without huGLO1...

Hepatitis C virus induces a prediabetic state by directly impairing hepatic glucose metabolism in mice.

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Lerat, Hervé; Imache, Mohamed Rabah; Polyte, Jacqueline; Gaudin, Aurore; Mercey, Marion; Donati, Flora; Baudesson, Camille; Higgs, Martin R; Picard, Alexandre; Magnan, Christophe; Foufelle, Fabienne; Pawlotsky, Jean-Michel

2017-08-04

Virus-related type 2 diabetes is commonly observed in individuals infected with the hepatitis C virus (HCV); however, the underlying molecular mechanisms remain unknown. Our aim was to unravel these mechanisms using FL-N/35 transgenic mice expressing the full HCV ORF. We observed that these mice displayed glucose intolerance and insulin resistance. We also found that Glut-2 membrane expression was reduced in FL-N/35 mice and that hepatocyte glucose uptake was perturbed, partly accounting for the HCV-induced glucose intolerance in these mice. Early steps of the hepatic insulin signaling pathway, from IRS2 to PDK1 phosphorylation, were constitutively impaired in FL-N/35 primary hepatocytes via deregulation of TNFα/SOCS3. Higher hepatic glucose production was observed in the HCV mice, despite higher fasting insulinemia, concomitant with decreased expression of hepatic gluconeogenic genes. Akt kinase activity was higher in HCV mice than in WT mice, but Akt-dependent phosphorylation of the forkhead transcription factor FoxO1 at serine 256, which triggers its nuclear exclusion, was lower in HCV mouse livers. These findings indicate an uncoupling of the canonical Akt/FoxO1 pathway in HCV protein-expressing hepatocytes. Thus, the expression of HCV proteins in the liver is sufficient to induce insulin resistance by impairing insulin signaling and glucose uptake. In conclusion, we observed a complete set of events leading to a prediabetic state in HCV-transgenic mice, providing a valuable mechanistic explanation for HCV-induced diabetes in humans. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Effects of the use of assisted reproductive technologies and an obesogenic environment on resistance artery function and diabetes biomarkers in mice offspring.

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Francisco I Ramirez-Perez

Full Text Available Maternal obesity affects the incidence of cardiovascular disease and diabetes in offspring. Also the use of assisted reproductive technologies (ART has been associated with cardiovascular deficiencies in offspring. Obese women often suffer from infertility and use ART to achieve a pregnancy, but the combined effects of maternal obesity and ART on cardiovascular health and incidence of diabetes in the offspring is not known. Here, we report the effects of the use of ART within an obesogenic environment, consisting of feeding a western diet (WD to dams and offspring, on resistance artery function and presence of diabetes biomarkers in juvenile mice offspring. Our results indicate that WD and ART interacted to induce endothelial dysfunction in mesenteric resistance arteries isolated from 7-week-old mice offspring. This was determined by presence of a reduced acetylcholine-induced dilation compared to controls. The arteries from these WD-ART mice also had greater wall cross-sectional areas and wall to lumen ratios indicative of vascular hypertrophic remodeling. Of the diabetes biomarkers measured, only resistin was affected by a WD×ART interaction. Serum resistin was significantly greater in WD-ART offspring compared to controls. Diet and sex effects were observed in other diabetes biomarkers. Our conclusion is that in mice the use of ART within an obesogenic environment interacts to favor the development of endothelial dysfunction in the resistance arteries of juvenile offspring, while having marginal effects on diabetes biomarkers.

Long-term obestatin treatment of mice type 2 diabetes increases insulin sensitivity and improves liver function.

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Kołodziejski, Paweł A; Pruszyńska-Oszmałek, Ewa; Strowski, Mathias Z; Nowak, Krzysztof W

2017-06-01

Obestatin and ghrelin are peptides encoded by the preproghrelin gene. Obestatin inhibits food intake, in addition to regulation of glucose and lipid metabolism. Here, we test the ability of obestatin at improving metabolic control and liver function in type 2 diabetic animals (type 2 diabetes mellitus). The effects of chronic obestatin treatment of mice with experimentally induced type 2 diabetes mellitus on serum levels of glucose and lipids, and insulin sensitivity are characterized. In addition, alterations of hepatic lipid and glycogen contents are evaluated. Obestatin reduced body weight and decreased serum glucose, fructosamine, and β-hydroxybutyrate levels, as well as total and low-density lipoprotein fractions of cholesterol. In addition, obestatin increased high-density lipoproteins cholesterol levels and enhanced insulin sensitivity in mice with type 2 diabetes mellitus. Moreover, obestatin diminished liver mass, hepatic triglycerides and cholesterol contents, while glycogen content was higher in livers of healthy and mice with type 2 diabetes mellitus treated with obestatin. These changes were accompanied by reduction of increased alanine aminotransferase, aspartate aminotransferase, and gamma glutamyl transpeptidase in T2DM mice with type 2 diabetes mellitus. Obestatin increased adiponectin levels and reduced leptin concentration. Obestatin influenced the expression of genes involved in lipid and carbohydrate metabolism by increasing Fabp5 and decreasing G6pc, Pepck, Fgf21 mRNA in the liver. Obestatin increased both, AKT and AMPK phosphorylation, and sirtuin 1 (SIRT1) protein levels as well as mRNA expression in the liver. Obestatin improves metabolic abnormalities in type 2 diabetes mellitus, restores hepatic lipid contents and decreases hepatic enzymes. Therefore, obestatin could potentially have a therapeutic relevance in treating of insulin resistance and metabolic dysfunctions in type 2 diabetes mellitus.

Spectratyping analysis of the islet-reactive T cell repertoire in diabetic NOD Igμnull mice after polyclonal B cell reconstitution

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Sercarz Eli E

2011-07-01

Full Text Available Abstract Background Non Obese Diabetic mice lacking B cells (NOD.Igμnull mice do not develop diabetes despite their susceptible background. Upon reconstitution of B cells using a chimera approach, animals start developing diabetes at 20 weeks of age. Methods We have used the spectratyping technique to follow the T cell receptor (TCR V beta repertoire of NOD.Igμnull mice following B cell reconstitution. This technique provides an unbiased approach to understand the kinetics of TCR expansion. We have also analyzed the TCR repertoire of reconstituted animals receiving cyclophosphamide treatment and following tissue transplants to identify common aggressive clonotypes. Results We found that B cell reconstitution of NOD.Igμnull mice induces a polyclonal TCR repertoire in the pancreas 10 weeks later, gradually diversifying to encompass most BV families. Interestingly, these clonotypic BV expansions are mainly confined to the pancreas and are absent from pancreatic lymph nodes or spleens. Cyclophosphamide-induced diabetes at 10 weeks post-B cell reconstitution reorganized the predominant TCR repertoires by removing potential regulatory clonotypes (BV1, BV8 and BV11 and increasing the frequency of others (BV4, BV5S2, BV9, BV16-20. These same clonotypes are more frequently present in neonatal pancreatic transplants under the kidney capsule of B-cell reconstituted diabetic NOD.Igμnull mice, suggesting their higher invasiveness. Phenotypic analysis of the pancreas-infiltrating lymphocytes during diabetes onset in B cell reconstituted animals show a predominance of CD19+ B cells with a B:T lymphocyte ratio of 4:1. In contrast, in other lymphoid organs (pancreatic lymph nodes and spleens analyzed by FACS, the B:T ratio was 1:1. Lymphocytes infiltrating the pancreas secrete large amounts of IL-6 and are of Th1 phenotype after CD3-CD28 stimulation in vitro. Conclusions Diabetes in NOD.Igμnull mice appears to be caused by a polyclonal repertoire of T cell

Diabetes susceptibility of BALB/cBOM mice treated with streptozotocin. Inhibition by lethal irradiation and restoration by splenic lymphocytes

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Paik, S.G.; Blue, M.L.; Fleischer, N.; Shin, S.

1982-01-01

In genetically susceptible strains of mice, repeated injections of a subdiabetogenic dose of streptozotocin induces the development of progressive insulin-dependent hyperglycemia. We showed previously that host T-cell functions play an obligatory etiologic role in this experimental disease by demonstrating that the athymic nude mouse is resistant to diabetes induction unless its T-cell functions are reconstituted by thymus graft. Here we show that lethal irradiation of euthymic (+/nu) mice of BALB/cBOM background causes selective resistance of the mice to the diabetogenic effects of the multiple low doses of streptozotocin without affecting their sensitivity to a high pharmacologic dose of the toxin. We also show that reconstitution of the irradiated mice with splenic lymphocytes causes the restoration of diabetes susceptibility. Lethally irradiated mice thus represent a useful experimental model for analyzing the host functions involved in the development of this disease. These results provide an additional support for the hypothesis that the induction of diabetes in this model system is mediated by an autoimmune amplification mechanism

Differential response of biochemical parameters to EMS and MMS treatments and their dose effect relationship on chromosomes in induced diabetic mouse

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B.B.D. Khalandar

2015-10-01

Conclusion: (1 Even though alkylating agents induce chromosomal aberrations in diabetic mice, MMS, a methylating agent is a more potent inducer of chromatid type of aberrations than EMS, an ethylating agent. (2 Diabetic mouse is more resistant than the non diabetic to alkylating agents and (3 the tested agents altered the analyzed biochemical parameters.

Renal Protective Effects of Low Molecular Weight of Inonotus obliquus Polysaccharide (LIOP on HFD/STZ-Induced Nephropathy in Mice

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Yen-Jung Chou

2016-09-01

Full Text Available Diabetic nephropathy (DN is the leading cause of end-stage renal disease in diabetes mellitus. Oxidative stress, insulin resistance and pro-inflammatory cytokines have been shown to play an important role in pathogeneses of renal damage on type 2 diabetes mellitus (DM. Inonotus obliquus (IO is a white rot fungus that belongs to the family Hymenochaetaceae; it has been used as an edible mushroom and exhibits many biological activities including anti-tumor, anti-oxidant, anti-inflammatory and anti-hyperglycemic properties. Especially the water-soluble Inonotus obliquus polysaccharides (IOPs have been previously reported to significantly inhibit LPS-induced inflammatory cytokines in mice and protect from streptozotocin (STZ-induced diabetic rats. In order to identify the nephroprotective effects of low molecular weight of IOP fraction (LIOP, from the fruiting bodies of Inonotus obliquus, high-fat diet (HFD plus STZ-induced type 2-like diabetic nephropathy C57BL/6 mice were investigated in this study. Our data showed that eight weeks of administration of 10–100 kDa, LIOP (300 mg/kg had progressively increased their sensitivity to glucose (less insulin tolerance, reduced triglyceride levels, elevated the HDL/LDL ratio and decreased urinary albumin/creatinine ratio(ACR compared to the control group. By pathological and immunohistochemical examinations, it was indicated that LIOP can restore the integrity of the glomerular capsules and increase the numbers of glomerular mesangial cells, associated with decreased expression of TGF-β on renal cortex in mice. Consistently, three days of LIOP (100 μg/mL incubation also provided protection against STZ + AGEs-induced glucotoxicity in renal tubular cells (LLC-PK1, while the levels of NF-κB and TGF-β expression significantly decreased in a dose-dependent manner. Our findings demonstrate that LIOP treatment could ameliorate glucolipotoxicity-induced renal fibrosis, possibly partly via the inhibition of NF

Effects of two antioxidants; α-lipoic acid and fisetin against diabetic cataract in mice.

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Kan, Emrah; Kiliçkan, Elif; Ayar, Ahmet; Çolak, Ramis

2015-02-01

The purpose of this study was to determine whether α-lipoic acid and fisetin have protective effects against cataract in a streptozotocin-induced experimental cataract model. Twenty-eight male BALB/C mice were made diabetic by the intraperitoneal administration of streptozotocin (200 mg/kg). Three weeks after induction of diabetes, mice were divided randomly into 4 groups in which each group contained 7 mice; fisetin-treated group (group 1), α-lipoic acid-treated group (group 2), fisetin placebo group (group 3), α-lipoic acid placebo group (group 4). Fisetin and α-lipoic acid were administered intraperitoneally weekly for 5 weeks. Cataract development was assessed at the end of 8 weeks by slit lamp examination, and cataract formation was graded using a scale. All groups developed at least grade 1 cataract formation. In the fisetin-treated group, the cataract stages were significantly lower than in the placebo group (p = 0.02). In the α-lipoic acid-treated group, the cataract stages were lower than in the placebo group but it did not reach to a significant value. Both fisetin and α-lipoic acid had a protective effect on cataract development in a streptozotocin-induced experimental cataract model. The protective effect of fisetin appears as though more effective than α-lipoic acid.

Hyperhomocysteinemia potentiates diabetes-impaired EDHF-induced vascular relaxation: Role of insufficient hydrogen sulfide

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Zhongjian Cheng

2018-06-01

Full Text Available Insufficient hydrogen sulfide (H2S has been implicated in Type 2 diabetic mellitus (T2DM and hyperhomocysteinemia (HHcy-related cardiovascular complications. We investigated the role of H2S in T2DM and HHcy-induced endothelial dysfunction in small mesenteric artery (SMA of db/db mice fed a high methionine (HM diet. HM diet (8 weeks induced HHcy in both T2DM db/db mice and non-diabetic db/+ mice (total plasma Hcy: 48.4 and 31.3 µM, respectively, and aggravated the impaired endothelium-derived hyperpolarization factor (EDHF-induced endothelium-dependent relaxation to acetylcholine (ACh, determined by the presence of eNOS inhibitor N(ω-nitro-L-arginine methyl ester (L-NAME and prostacyclin (PGI2 inhibitor indomethacin (INDO, in SMA from db/db mice but not that from db/+ mice. A non-selective Ca2+-active potassium channel (KCa opener NS309 rescued T2DM/HHcy-impaired EDHF-mediated vascular relaxation to ACh. EDHF-induced relaxation to ACh was inhibited by a non-selective KCa blocker TEA and intermediate-conductance KCa blocker (IKCa Tram-34, but not by small-conductance KCa (SKCa blocker Apamin. HHcy potentiated the reduction of free sulfide, H2S and cystathionine γ-lyase protein, which converts L-cysteine to H2S, in SMA of db/db mice. Importantly, a stable H2S donor DATS diminished the enhanced O2- production in SMAs and lung endothelial cells of T2DM/HHcy mice. Antioxidant PEG-SOD and DATS improved T2DM/HHcy impaired relaxation to ACh. Moreover, HHcy increased hyperglycemia-induced IKCa tyrosine nitration in human micro-vascular endothelial cells. EDHF-induced vascular relaxation to L-cysteine was not altered, whereas such relaxation to NaHS was potentiated by HHcy in SMA of db/db mice which was abolished by ATP-sensitive potassium channel blocker Glycolamide but not by KCa blockers. Conclusions: Intermediate HHcy potentiated H2S reduction via CSE-downregulation in microvasculature of T2DM mice. H2S is justified as an EDHF. Insufficient H2S

Impaired Leptomeningeal Collateral Flow Contributes to the Poor Outcome following Experimental Stroke in the Type 2 Diabetic Mice

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Akamatsu, Yosuke; Nishijima, Yasuo; Lee, Chih Cheng; Yang, Shih Yen; Shi, Lei; An, Lin; Wang, Ruikang K.; Tominaga, Teiji

2015-01-01

Collateral status is an independent predictor of stroke outcome. However, the spatiotemporal manner in which collateral flow maintains cerebral perfusion during cerebral ischemia is poorly understood. Diabetes exacerbates ischemic brain damage, although the impact of diabetes on collateral dynamics remains to be established. Using Doppler optical coherent tomography, a robust recruitment of leptomeningeal collateral flow was detected immediately after middle cerebral artery (MCA) occlusion in C57BL/6 mice, and it continued to grow over the course of 1 week. In contrast, an impairment of collateral recruitment was evident in the Type 2 diabetic db/db mice, which coincided with a worse stroke outcome compared with their normoglycemic counterpart db/+, despite their equally well-collateralized leptomeningeal anastomoses. Similar to the wild-type mice, both db/+ and db/db mice underwent collateral growth 7 d after MCA stroke, although db/db mice still exhibited significantly reduced retrograde flow into the MCA territory chronically. Acutely induced hyperglycemia in the db/+ mice did not impair collateral flow after stroke, suggesting that the state of hyperglycemia alone was not sufficient to impact collateral flow. Human albumin was efficacious in improving collateral flow and outcome after stroke in the db/db mice, enabling perfusion to proximal MCA territory that was usually not reached by retrograde flow from anterior cerebral artery without treatment. Our results suggest that the impaired collateral status contributes to the exacerbated ischemic injury in mice with Type 2 diabetes, and modulation of collateral flow has beneficial effects on stroke outcome among these subjects. PMID:25740515

Characterization and comparison of SGLT2 inhibitors: Part 3. Effects on diabetic complications in type 2 diabetic mice.

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Tahara, Atsuo; Takasu, Toshiyuki; Yokono, Masanori; Imamura, Masakazu; Kurosaki, Eiji

2017-08-15

In this study, we investigated and compared the effects of all six sodium-glucose cotransporter (SGLT) 2 inhibitors commercially available in Japan on diabetes-related diseases and complications in type 2 diabetic mice. Following 4-week repeated administration to diabetic mice, all SGLT2 inhibitors showed significant improvement in diabetes-related diseases and complications, including obesity; abnormal lipid metabolism; steatohepatitis; inflammation; endothelial dysfunction; and nephropathy. While all SGLT2 inhibitors exerted comparable effects in reducing hyperglycemia, improvement of these diabetes-related diseases and complications was more potent with the two long-acting drugs (ipragliflozin and dapagliflozin) than with the four intermediate-acting four drugs (tofogliflozin, canagliflozin, empagliflozin, and luseogliflozin), albeit without statistical significance. These findings demonstrate that SGLT2 inhibitors alleviate various diabetic pathological conditions in type 2 diabetic mice, and suggest that SGLT2 inhibitors, particularly long-acting drugs, might be useful not only for hyperglycemia but also in diabetes-related diseases and complications, including nephropathy in type 2 diabetes. Copyright © 2017 Elsevier B.V. All rights reserved.

Gluten-free but also gluten-enriched (gluten+) diet prevent diabetes in NOD mice; the gluten enigma in type 1 diabetes.

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Funda, David P; Kaas, Anne; Tlaskalová-Hogenová, Helena; Buschard, Karsten

2008-01-01

Environmental factors such as nutrition or exposure to infections play a substantial role in the pathogenesis of type 1 diabetes (T1D). We have previously shown that gluten-free, non-purified diet largely prevented diabetes in non-obese diabetic (NOD) mice. In this study we tested hypothesis that early introduction of gluten-enriched (gluten+) diet may increase diabetes incidence in NOD mice. Standard, gluten-free, gluten+ modified Altromin diets and hydrolysed-casein-based Pregestimil diet were fed to NOD females and diabetes incidence was followed for 310 days. Insulitis score and numbers of gut mucosal lymphocytes were determined in non-diabetic animals. A significantly lower diabetes incidence (p gluten-free diet (5.9%, n = 34) and Pregestimil diet (10%, n = 30) compared to mice on the standard Altromin diet (60.6%, n = 33). Surprisingly, gluten+ diet also prevented diabetes incidence, even at the level found with the gluten-free diet (p gluten+, gluten-free, Pregestimil) diets, did that slightly later compared to those on the standard diet. Lower insulitis score compared to control mice was found in non-diabetic NOD mice on the gluten-free, and to a lesser extent also gluten+ and Pregestimil diets. No substantial differences in the number of CD3(+), TCR-gammadelta(+), and IgA(+) cells in the small intestine were documented. Gluten+ diet prevents diabetes in NOD mice at the level found with the non-purified gluten-free diet. Possible mechanisms of the enigmatic, dual effect of dietary gluten on the development of T1D are discussed. 2007 John Wiley & Sons, Ltd

Benfotiamine alleviates diabetes-induced cerebral oxidative damage independent of advanced glycation end-product, tissue factor and TNF-alpha.

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Wu, Shan; Ren, Jun

2006-02-13

Diabetes mellitus leads to thiamine deficiency and multiple organ damage including diabetic neuropathy. This study was designed to examine the effect of benfotiamine, a lipophilic derivative of thiamine, on streptozotocin (STZ)-induced cerebral oxidative stress. Adult male FVB mice were made diabetic with a single injection of STZ (200 mg/kg, i.p.). Fourteen days later, control and diabetic (fasting blood glucose >13.9 mM) mice received benfotiamine (100 mg/kg/day, i.p.) for 14 days. Oxidative stress and protein damage were evaluated by glutathione/glutathione disulfide (GSH/GSSG) assay and protein carbonyl formation, respectively. Pro-oxidative or pro-inflammatory factors including advanced glycation end-product (AGE), tissue factor and tumor necrosis factor-alpha (TNF-alpha) were evaluated by immunoblot analysis. Four weeks STZ treatment led to hyperglycemia, enhanced cerebral oxidative stress (reduced GSH/GSSG ratio), elevated TNF-alpha and AGE levels without changes in protein carbonyl or tissue factor. Benfotiamine alleviated diabetes-induced cerebral oxidative stress without affecting levels of AGE, protein carbonyl, tissue factor and TNF-alpha. Collectively, our results indicated benfotiamine may antagonize diabetes-induced cerebral oxidative stress through a mechanism unrelated to AGE, tissue factor and TNF-alpha.

Altered metabolic signature in pre-diabetic NOD mice.

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Rasmus Madsen

Full Text Available Altered metabolism proceeding seroconversion in children progressing to Type 1 diabetes has previously been demonstrated. We tested the hypothesis that non-obese diabetic (NOD mice show a similarly altered metabolic profile compared to C57BL/6 mice. Blood samples from NOD and C57BL/6 female mice was collected at 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13 and 15 weeks and the metabolite content was analyzed using GC-MS. Based on the data of 89 identified metabolites OPLS-DA analysis was employed to determine the most discriminative metabolites. In silico analysis of potential involved metabolic enzymes was performed using the dbSNP data base. Already at 0 weeks NOD mice displayed a unique metabolic signature compared to C57BL/6. A shift in the metabolism was observed for both strains the first weeks of life, a pattern that stabilized after 5 weeks of age. Multivariate analysis revealed the most discriminative metabolites, which included inosine and glutamic acid. In silico analysis of the genes in the involved metabolic pathways revealed several SNPs in either regulatory or coding regions, some in previously defined insulin dependent diabetes (Idd regions. Our result shows that NOD mice display an altered metabolic profile that is partly resembling the previously observation made in children progressing to Type 1 diabetes. The level of glutamic acid was one of the most discriminative metabolites in addition to several metabolites in the TCA cycle and nucleic acid components. The in silico analysis indicated that the genes responsible for this reside within previously defined Idd regions.

Plasma lipid oxidation predicts atherosclerotic status better than cholesterol in diabetic apolipoprotein E deficient mice

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Petersen, Karen Ekkelund; Lykkesfeldt, Jens; Raun, Kirsten

2017-01-01

Increased levels of oxidative stress have been suggested to play a detrimental role in the development of diabetes-related vascular complications. Here, we investigated whether the concentration of malondialdehyde, a marker of lipid oxidation correlated to the degree of aortic plaque lesions...... in a proatherogenic diabetic mouse model. Three groups of apolipoprotein E knockout mice were studied for 20 weeks, a control, a streptozotocin-induced diabetic, and a diabetic enalapril-treated group. Enalapril was hypothesized to lower oxidative stress level and thus the plaque burden. Both diabetic groups were...... significantly different from the control group as they had higher blood glucose, HbA1c, total cholesterol, low-density lipoprotein, very low-density lipoprotein, together with a lower high-density lipoprotein concentration and body weight. Animals in the diabetic group had significantly higher plaque area...

Inhibition mechanism of compound ethanol extracts from wuweizi (fructus schisandrae chinensis) on renal interstitial fibrosis in diabetic nephropathy model mice.

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Zhang, Yanqiu; Zhang, Daning; Zhang, Mianzhi

2012-12-01

To evaluate inhibition effect and mechanism of compound ethanol extracts from Wuweizi (Fructus Schisandrae Chinensis), Chuanxiong (Rhizoma Chuanxiong) and Muli (Cocha Ostreae) (FRC) on glomerular and tubular interstitial fibrosis in streptozocin (STZ)-induced diabetic nephropathy (ND) model mice. Twenty-seven male C57BL/6 mice were divided randomly into 3 groups: nondibetic (ND), STZ-induced diabetic (D), and STZ-induced diabetic that were treated with 5 g x kg(-1) x day(-1) of FRC by oral gavage (D(FRC)), with 9 in each group. The protein expressions of E-cadherin, alpha-smooth muscle actin (alpha-SMA), Plasminogen Activator Inhibitor-1 (PAL-1) in renal tissues were investigated by Western blotting. The expressions of fibronectin (FN) and alpha-SMA were detected by immunohistochemical method. The morphological changes of renal tissues were observed under a microscope. Renal tissues in the D(FRC) group showed a lessened degree of fibrosis. Meanwhile, the expressions of FN, alpha-SMA and PAI-1 were significantly lower in the D(FRC) group than those in the D group (all P < 0.05). FRC can ameliorate the DN in the C57BL/6 mice, and its mechanism may relate to inhibition on the epithelial to mesenchymal transdifferentiation, endothelial-myofibroblast transition and PAL-1 expression.

Aldose Reductase-Deficient Mice Develop Nephrogenic Diabetes Insipidus

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

2000-01-01

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

Anti-diabetic potential of the essential oil of Pinus koraiensis leaves toward streptozotocin-treated mice and HIT-T15 pancreatic β cells.

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Joo, Hye-Eun; Lee, Hyo-Jung; Sohn, Eun Jung; Lee, Min-Ho; Ko, Hyun-Suk; Jeong, Soo-Jin; Lee, Hyo-Jeong; Kim, Sung-Hoon

2013-01-01

The metabolic syndrome creates risk factors for coronary heart disease, diabetes, fatty liver, obesity and several cancers. Our group has already reported that the essential oil from leaves of Pinus koraiensis SIEB (EOPK) exerted antihyperlipidemic effects by upregulating the low-density lipoprotein receptor and inhibiting acyl-coenzyme A, cholesterol acyltransferases. We evaluated in the current study the anti-diabetic effects of EOPK on mice with streptozotocin (STZ)-induced type I diabetes and on HIT-T15 pancreatic β cells. EOPK significantly protected HIT-T15 cells from STZ-induced cytotoxicity and reduced the blood glucose level in STZ-induced diabetic mice when compared with the untreated control. EOPK consistently and significantly suppressed the α-amylase activity in a dose-dependent manner and enhanced the expression of insulin at the mRNA level in STZ-treated HIT-T15 cells, while the expression of insulin was attenuated. EOPK also significantly abrogated the population of reactive oxygen species when compared to the untreated control in STZ-treated HIT-T15 cells. Furthermore, EOPK significantly reduce nitric oxide production, suppressed the phosphorylation of endothelial nitric oxide (NO) synthase and suppressed the production of vascular endothelial growth factor (VEGF) in STZ-treated HIT-T15 cells, implying its potential application to diabetic retinopathy. Overall, our findings suggest that EOPK had hypoglycemic potential by inhibiting reactive oxygene species (ROS), endothelial NO synthase (eNOS) and VEGF in STZ-treated mice and HIT-T15 pancreatic β cells as a potent anti-diabetic agent.

Bezafibrate ameliorates diabetes via reduced steatosis and improved hepatic insulin sensitivity in diabetic TallyHo mice

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Andras Franko

2017-03-01

Full Text Available Objective: Recently, we have shown that Bezafibrate (BEZ, the pan-PPAR (peroxisome proliferator-activated receptor activator, ameliorated diabetes in insulin deficient streptozotocin treated diabetic mice. In order to study whether BEZ can also improve glucose metabolism in a mouse model for fatty liver and type 2 diabetes, the drug was applied to TallyHo mice. Methods: TallyHo mice were divided into an early (ED and late (LD diabetes progression group and both groups were treated with 0.5% BEZ (BEZ group or standard diet (SD group for 8 weeks. We analyzed plasma parameters, pancreatic beta-cell morphology, and mass as well as glucose metabolism of the BEZ-treated and control mice. Furthermore, liver fat content and composition as well as hepatic gluconeogenesis and mitochondrial mass were determined. Results: Plasma lipid and glucose levels were markedly reduced upon BEZ treatment, which was accompanied by elevated insulin sensitivity index as well as glucose tolerance, respectively. BEZ increased islet area in the pancreas. Furthermore, BEZ treatment improved energy expenditure and metabolic flexibility. In the liver, BEZ ameliorated steatosis, modified lipid composition and increased mitochondrial mass, which was accompanied by reduced hepatic gluconeogenesis. Conclusions: Our data showed that BEZ ameliorates diabetes probably via reduced steatosis, enhanced hepatic mitochondrial mass, improved metabolic flexibility and elevated hepatic insulin sensitivity in TallyHo mice, suggesting that BEZ treatment could be beneficial for patients with NAFLD and impaired glucose metabolism. Keywords: Bezafibrate, Glucose metabolism, Insulin resistance, Lipid metabolism, NAFLD

Exenatide improves glucocorticoid-induced glucose intolerance in mice

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Ruiying Zhao

2011-01-01

Full Text Available Ruiying Zhao1,2*, Enrique Fuentes-Mattei1,2*, Guermarie Velazquez-Torres1,3, Chun-Hui Su1,2, Jian Chen1, Mong-Hong Lee1,2, Sai-Ching Jim Yeung4,51Department of Molecular and Cellular Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, USA; 2Program in Genes and Development, 3Program in Cancer Biology, Graduate School of Biomedical Sciences, University of Texas Health Science Center in Houston, Houston, TX, USA; 4Department of Endocrine Neoplasia and Hormonal Disorders, 5Department of Emergency Medicine, University of Texas MD Anderson Cancer Center, Houston, TX, USA *Both authors contributed equally.Abstract: Exenatide is an incretin mimetic that is recently available in the US for the treatment of diabetes. There is a paucity of information on the effects of exenatide in glucocorticoid (GC-induced diabetes. Although the effect of continuous intravenous infusion of exenatide on GC-induced glucose intolerance has been investigated before in healthy human males receiving oral prednisolone, we investigated the efficacy of a single subcutaneous dose of exenatide (3 µg/kg in lowering blood glucose in GC-induced glucose intolerance in C57BL/6 mice. In a longitudinal experiment, the area under the curve (AUC of oral glucose tolerance tests (OGTT significantly increased after dexamethasone (P = 0.004, which was subsequently decreased by exenatide (P < 0.001. A cross-sectional experiment showed that exenatide improved glucose tolerance compared with placebo in a mouse model of dexamethasone-induced glucose intolerance. AUC of OGTT in the exenatide group were significantly (P < 0.001 lower than in the placebo group. Insulin tolerance tests (ITT demonstrated that exenatide decreased the ability of the mice to tolerate insulin compared with placebo. The AUC of ITT in the exenatide group were also significantly (P = 0.006 lower than in the placebo group. In conclusion, a single dose of exenatide was able to decrease glucose intolerance and

Comparison of cerebral microcirculation of alloxan diabetes and healthy mice using laser speckle contrast imaging

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Timoshina, Polina A.; Shi, Rui; Zhang, Yang; Zhu, Dan; Semyachkina-Glushkovskaya, Oxana V.; Tuchin, Valery V.; Luo, Qingming

2015-03-01

The study of blood microcirculation is one of the most important problems of the medicine. This paper presents results of experimental study of cerebral blood flow microcirculation in mice with alloxan-induced diabetes using Temporal Laser Speckle Imaging (TLSI). Additionally, a direct effect of glucose water solution (concentration 20% and 45%) on blood flow microcirculation was studied. In the research, 20 white laboratory mice weighing 20-30 g were used. The TLSI method allows one to investigate time dependent scattering from the objects with complex dynamics, since it possesses greater temporal resolution. Results show that in brain of animal diabetic group diameter of sagittal vein is increased and the speed of blood flow reduced relative to the control group. Topical application of 20%- or 45%-glucose solutions also causes increase of diameter of blood vessels and slows down blood circulation. The results obtained show that diabetes development causes changes in the cerebral microcirculatory system and TLSI techniques can be effectively used to quantify these alterations.

Effects of Bauhinia forficata Tea on Oxidative Stress and Liver Damage in Diabetic Mice.

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Salgueiro, Andréia Caroline Fernandes; Folmer, Vanderlei; da Silva, Marianne Pires; Mendez, Andreas Sebastian Loureiro; Zemolin, Ana Paula Pegoraro; Posser, Thaís; Franco, Jeferson Luis; Puntel, Robson Luiz; Puntel, Gustavo Orione

2016-01-01

This study was designed to evaluate the effects of Bauhinia forficata Link subsp. pruinosa (BF) tea on oxidative stress and liver damage in streptozotocin (STZ)-induced diabetic mice. Diabetic male mice have remained 30 days without any treatment. BF treatment started on day 31 and continued for 21 days as a drinking-water substitute. We evaluated (1) BF chemical composition; (2) glucose levels; (3) liver/body weight ratio and liver transaminases; (4) reactive oxygen species (ROS), lipid peroxidation, and protein carbonylation in liver; (5) superoxide dismutase (SOD) and catalase (CAT) activities in liver; (6) δ-aminolevulinate dehydratase (δ-ALA-D) and nonprotein thiols (NPSH) in liver; (7) Nrf2, NQO-1, and HSP70 levels in liver and pancreas. Phytochemical analyses identified four phenols compounds. Diabetic mice present high levels of NQO-1 in pancreas, increased levels of ROS and lipid peroxidation in liver, and decrease in CAT activity. BF treatment normalized all these parameters. BF did not normalize hyperglycemia, liver/body weight ratio, aspartate aminotransferase, protein carbonyl, NPSH levels, and δ-ALA-D activity. The raised oxidative stress seems to be a potential mechanism involved in liver damage in hyperglycemic conditions. Our results indicated that BF protective effect could be attributed to its antioxidant capacity, more than a hypoglycemic potential.

Effects of Bauhinia forficata Tea on Oxidative Stress and Liver Damage in Diabetic Mice

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Andréia Caroline Fernandes Salgueiro

2016-01-01

Full Text Available This study was designed to evaluate the effects of Bauhinia forficata Link subsp. pruinosa (BF tea on oxidative stress and liver damage in streptozotocin (STZ-induced diabetic mice. Diabetic male mice have remained 30 days without any treatment. BF treatment started on day 31 and continued for 21 days as a drinking-water substitute. We evaluated (1 BF chemical composition; (2 glucose levels; (3 liver/body weight ratio and liver transaminases; (4 reactive oxygen species (ROS, lipid peroxidation, and protein carbonylation in liver; (5 superoxide dismutase (SOD and catalase (CAT activities in liver; (6 δ-aminolevulinate dehydratase (δ-ALA-D and nonprotein thiols (NPSH in liver; (7 Nrf2, NQO-1, and HSP70 levels in liver and pancreas. Phytochemical analyses identified four phenols compounds. Diabetic mice present high levels of NQO-1 in pancreas, increased levels of ROS and lipid peroxidation in liver, and decrease in CAT activity. BF treatment normalized all these parameters. BF did not normalize hyperglycemia, liver/body weight ratio, aspartate aminotransferase, protein carbonyl, NPSH levels, and δ-ALA-D activity. The raised oxidative stress seems to be a potential mechanism involved in liver damage in hyperglycemic conditions. Our results indicated that BF protective effect could be attributed to its antioxidant capacity, more than a hypoglycemic potential.

Hypoglycemic effect of DL-aminocarnitine in streptozotocin diabetic mice: inhibition of gluconeogenesis

International Nuclear Information System (INIS)

Jenkins, D.L.; Griffith, O.W.

1986-01-01

DL-Aminocarnitine and palmitoyl-DL-aminocarnitine are potent, non-covalent inhibitors of carnitine palmitoyl transferase. In both diabetic and non-diabetic fasted mice, DL-aminocarnitine (0.3 mmol/kg) and palmitoyl-DL-aminocarnitine (0.1 mmol/kg) decrease the blood concentration of ketone bodies to levels observed in fed control mice. Both carnitine palmitoyltransferase inhibitors also normalize plasma glucose levels in diabetic mice. The hypoglycemic effect is maximal at 8 hours, the continues for at least 12 hours. In the present studies the authors have used [ 14 C]alanine, a pyruvate precursor, to prove the effect of aminocarnitine on gluconeogenesis. Diabetic mice given L-[U- 14 C]alanine (1 mmol/kg) by intraperitoneal injection convert 10-15% of the administered dose to [ 14 C]glucose after 10 min; less than 0.1% of the radioactivity is recovered in glycogen. If 0.3 mmol/kg aminocarnitine is given subcutaneously 1 hr prior to giving [ 14 C]analine, the radioactivity recovered in plasma glucose is reduced by approximately 40%. The authors conclude that the hypoglycemic effect of DL-aminocarnitine in diabetic mice is due, at least in part, to inhibition of gluconeogenesis. The possibility that aminocarnitine also stimulates glucose utilization in diabetic animals is not excluded

Severe pulmonary metastasis in obese and diabetic mice.

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Mori, Akinori; Sakurai, Hiroaki; Choo, Min-Kyung; Obi, Ryosuke; Koizumi, Keiichi; Yoshida, Chiho; Shimada, Yutaka; Saiki, Ikuo

2006-12-15

Although obesity is known as a risk factor for several human cancers, the association of obesity with cancer recurrence and metastasis remains to be characterized. Here, B16-BL6 melanoma and Lewis lung carcinoma cells were intravenously injected into diabetic (db/db) and obese (ob/ob) mice. The number of experimental lung colonies was markedly promoted in these mice when compared with C57BL/6 mice. In contrast, tumor growth at the implanted site was comparable when cells were inoculated orthotopically. The use of B16-BL6 cells stably transfected with the luciferase gene revealed that the increased metastasis reflected a difference mainly within 6 hr after the intravenous inoculation of tumor cells. Administration of recombinant leptin in ob/ob mice abolished the increase in metastasis early on as well as the decrease in the splenic NK cell number. In addition, depletion of NK cells by an anti-asialo-GM1 antibody abrogated the enhanced metastasis in db/db mice. These results demonstrate that metastasis is markedly promoted in diabetic and obese mice mainly because of decreased NK cell function during the early phase of metastasis. Copyright 2006 Wiley-Liss, Inc.

Gluten-free but also gluten-enriched (gluten+) diet prevent diabetes in NOD mice; the gluten enigma in type 1 diabetes

DEFF Research Database (Denmark)

Funda, D.P.; Kaas, A.; Tlaskalova-Hogenova, H.

2008-01-01

BACKGROUND: Environmental factors such as nutrition or exposure to infections play a substantial role in the pathogenesis of type 1 diabetes (T1D). We have previously shown that gluten-free, non-purified diet largely prevented diabetes in non-obese diabetic (NOD) mice. In this study we tested...... hypothesis that early introduction of gluten-enriched (gluten+) diet may increase diabetes incidence in NOD mice. METHODS: Standard, gluten-free, gluten+ modified Altromin diets and hydrolysed-casein-based Pregestimil diet were fed to NOD females and diabetes incidence was followed for 310 days. Insulitis...... score and numbers of gut mucosal lymphocytes were determined in non-diabetic animals. RESULTS: A significantly lower diabetes incidence (p diet (5.9%, n = 34) and Pregestimil diet (10%, n = 30) compared to mice on the standard Altromin diet (60.6%, n...

Comparison of biochemical properties of liver arginase from streptozocin-induced diabetic and control mice.

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Spolarics, Z; Bond, J S

1989-11-01

Arginase activity is elevated in livers of diabetic animals compared to controls and there is evidence that this is due in part to increased specific activity (activity/mg arginase protein). To investigate the molecular basis of this increased activity, the physicochemical and kinetic properties of hepatic arginase from diabetic and control mice were compared. Two types of arginase subunits with molecular weights of 35,000 and 38,000 were found in both the diabetic and control animals and the subunits in these animals had similar, multiple ionic forms. Kinetic parameters of purified preparations of arginase for arginine (apparent Km and Vmax values) and the thermal stability of these preparations from diabetics and controls were also similar. Furthermore, no difference was found in the distribution of arginase activity among different subcellular liver fractions. Separation of basic and acidic oligomeric forms of arginase by fast-protein liquid chromatography resulted in a slightly different distribution of activity among the forms in the normal and diabetic group. The apparent Km values for Mn2+ of the basic form of the enzyme were 25 and 33 microM for the enzyme from normal and diabetic animals, respectively; for acidic forms, for which two apparent Km values were measured, the values were 8 and 197 microM for arginase from controls and 35 and 537 microM from diabetics. These results indicate that in diabetes, while no marked changes in the physicochemical characteristics of arginase are obvious, some changes are found in the interaction of arginase with its cofactor Mn.

Bisphenol A (BPA) aggravates multiple low-dose streptozotocin-induced Type 1 diabetes in C57BL/6 mice.

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Cetkovic-Cvrlje, Marina; Thinamany, Sinduja; Bruner, Kylie A

2017-12-01

Type 1 diabetes (T1D) is a T-cell-mediated autoimmune disorder characterized by destruction of insulin-producing pancreatic β-cells. Whereas epidemiological data implicate environmental factors in the increasing incidence of T1D, their identity remains unknown. Though exposure to bisphenol A (BPA) has been associated with several disorders, no epidemiologic evidence has linked BPA exposure and T1D. The goal of this study was to elucidate diabetogenic potentials of BPA and underlying mechanisms in the context of T-cell immunity, in a multiple low-dose streptozotocin (MLDSTZ)-induced autoimmune mouse T1D model. C57BL/6 mice were orally exposed to 1 or 10 mg BPA/L starting at 4 wk of age; diabetes was induced at 9 wk of age with STZ. T-cell composition, function, and insulitis levels were studied at Days 11 and 50 during diabetes development (i.e. post-first STZ injection). Results showed both BPA doses increased diabetes incidence and affected T-cell immunity. However, mechanisms of diabetogenic action appeared divergent based on dose. Low-dose BPA fits a profile of an agent that exhibits pro-diabetogenic effects via T-cell immunomodulation in the early stages of disease development, i.e. decreases in splenic T-cell subpopulations [especially CD4 + T-cells] along with a trend in elevation of splenic T-cell formation of pro-inflammatory cytokines (IFN-γ, TNF-α, and IL-6). In contrast, high-dose BPA did not affect T-cell populations and led to decreased levels of IFN-γ and TNF-α. Both treatments did not affect insulitis levels at the disease early stage, but aggravated it later on. By the study end, besides decreasing T-cell proliferative capacity, low-dose BPA did not affect other T-cell-related parameters, including cytokine secretion, comparable to the effects of high-dose BPA. In conclusion, this study confirmed BPA as a potential diabetogenic compound with immunomodulatory mechanisms of action - in the context of T-cell immunity - that seemed to be dose

Type 2 diabetes mellitus induces congenital heart defects in murine embryos by increasing oxidative stress, endoplasmic reticulum stress, and apoptosis.

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Wu, Yanqing; Reece, E Albert; Zhong, Jianxiang; Dong, Daoyin; Shen, Wei-Bin; Harman, Christopher R; Yang, Peixin

2016-09-01

Maternal type 1 and 2 diabetes mellitus are strongly associated with high rates of severe structural birth defects, including congenital heart defects. Studies in type 1 diabetic embryopathy animal models have demonstrated that cellular stress-induced apoptosis mediates the teratogenicity of maternal diabetes leading to congenital heart defect formation. However, the mechanisms underlying maternal type 2 diabetes mellitus-induced congenital heart defects remain largely unknown. We aim to determine whether oxidative stress, endoplasmic reticulum stress, and excessive apoptosis are the intracellular molecular mechanisms underlying maternal type 2 diabetes mellitus-induced congenital heart defects. A mouse model of maternal type 2 diabetes mellitus was established by feeding female mice a high-fat diet (60% fat). After 15 weeks on the high-fat diet, the mice showed characteristics of maternal type 2 diabetes mellitus. Control dams were either fed a normal diet (10% fat) or the high-fat diet during pregnancy only. Female mice from the high-fat diet group and the 2 control groups were mated with male mice that were fed a normal diet. At E12.5, embryonic hearts were harvested to determine the levels of lipid peroxides and superoxide, endoplasmic reticulum stress markers, cleaved caspase 3 and 8, and apoptosis. E17.5 embryonic hearts were harvested for the detection of congenital heart defect formation using India ink vessel patterning and histological examination. Maternal type 2 diabetes mellitus significantly induced ventricular septal defects and persistent truncus arteriosus in the developing heart, along with increasing oxidative stress markers, including superoxide and lipid peroxidation; endoplasmic reticulum stress markers, including protein levels of phosphorylated-protein kinase RNA-like endoplasmic reticulum kinase, phosphorylated-IRE1α, phosphorylated-eIF2α, C/EBP homologous protein, and binding immunoglobulin protein; endoplasmic reticulum chaperone gene

In vivo imaging of oxidative stress in the kidney of diabetic mice and its normalization by angiotensin II type 1 receptor blocker

International Nuclear Information System (INIS)

Sonta, Toshiyo; Inoguchi, Toyoshi; Matsumoto, Shingo; Yasukawa, Keiji; Inuo, Mieko; Tsubouchi, Hirotaka; Sonoda, Noriyuki; Kobayashi, Kunihisa; Utsumi, Hideo; Nawata, Hajime

2005-01-01

This study was undertaken to evaluate oxidative stress in the kidney of diabetic mice by electron spin resonance (ESR) imaging technique. Oxidative stress in the kidney was evaluated as organ-specific reducing activity with the signal decay rates of carbamoyl-PROXYL probe using ESR imaging. The signal decay rates were significantly faster in corresponding image pixels of the kidneys of streptozotocin-induced diabetic mice than in those of controls. This technique further demonstrated that administration of angiotensin II type 1 receptor blocker (ARB), olmesartan (5 mg/kg), completely restored the signal decay rates in the diabetic kidneys to control values. In conclusion, this study provided for the first time the in vivo evidence for increased oxidative stress in the kidneys of diabetic mice and its normalization by ARB as evaluated by ESR imaging. This technique would be useful as a means of further elucidating the role of oxidative stress in diabetic nephropathy

Gastro-Resistant Insulin Receptor-Binding Peptide from Momordica charantia Improved the Glucose Tolerance in Streptozotocin-Induced Diabetic Mice via Insulin Receptor Signaling Pathway.

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Lo, Hsin-Yi; Li, Chia-Cheng; Chen, Feng-Yuan; Chen, Jaw-Chyun; Hsiang, Chien-Yun; Ho, Tin-Yun

2017-10-25

Momordica charantia is a commonly used food and has been used for the management of diabetes. Our previous study has identified an insulin receptor (IR)-binding protein (mcIRBP) from Momordica charantia. Here we identified the gastro-resistant hypoglycemic bioactive peptides from protease-digested mcIRBP. By in vitro digestion and IR kinase activity assay, we found that a 9-amino-acid-residue peptide, mcIRBP-9, was a gastro-resistant peptide that enhanced IR kinase activities. mcIRBP-9 activated IR signaling transduction pathway, which resulted in the phosphorylation of IR, the translocation of glucose transporter 4, and the uptake of glucose in cells. Intraperitoneal and oral administration of mcIRBP-9 stimulated the glucose clearance by 30.91 ± 0.39% and 32.09 ± 0.38%, respectively, in streptozotocin-induced diabetic mice. Moreover, a pilot study showed that daily ingestion of mcIRBP-9 for 30 days decreased the fasting blood glucose levels and glycated hemoglobin (HbA1c) levels by 23.62 ± 6.14% and 24.06 ± 1.53%, respectively. In conclusion, mcIRBP-9 is a unique gastro-resistant bioactive peptide generated after the digestion of mcIRBP. Furthermore, oral administration of mcIRBP-9 improves both the glucose tolerance and the HbA1c levels in diabetic mice via targeting IR signaling transduction pathway.

Cardiac-specific overexpression of catalase prevents diabetes-induced pathological changes by inhibiting NF-κB signaling activation in the heart.

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Cong, Weitao; Ruan, Dandan; Xuan, Yuanhu; Niu, Chao; Tao, Youli; Wang, Yang; Zhan, Kungao; Cai, Lu; Jin, Litai; Tan, Yi

2015-12-01

Catalase is an antioxidant enzyme that specifically catabolizes hydrogen peroxide (H2O2). Overexpression of catalase via a heart-specific promoter (CAT-TG) was reported to reduce diabetes-induced accumulation of reactive oxygen species (ROS) and further prevent diabetes-induced pathological abnormalities, including cardiac structural derangement and left ventricular abnormity in mice. However, the mechanism by which catalase overexpression protects heart function remains unclear. This study found that activation of a ROS-dependent NF-κB signaling pathway was downregulated in hearts of diabetic mice overexpressing catalase. In addition, catalase overexpression inhibited the significant increase in nitration levels of key enzymes involved in energy metabolism, including α-oxoglutarate dehydrogenase E1 component (α-KGD) and ATP synthase α and β subunits (ATP-α and ATP-β). To assess the effects of the NF-κB pathway activation on heart function, Bay11-7082, an inhibitor of the NF-κB signaling pathway, was injected into diabetic mice, protecting mice against the development of cardiac damage and increased nitrative modifications of key enzymes involved in energy metabolism. In conclusion, these findings demonstrated that catalase protects mouse hearts against diabetic cardiomyopathy, partially by suppressing NF-κB-dependent inflammatory responses and associated protein nitration. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of low dose radiation on kidney function and morphology of diabetic mice

International Nuclear Information System (INIS)

Zhang Chi; Li Xiaokun; Gong Shouliang; Meng Tao; Li Cai; Cai Lu

2010-01-01

Objective: To study the effect of low dose radiation (LDR) on the kidney function and morphology in C57BL/6J mice with diabetic nephropathy (DN) induced by streptozotocin (STZ) and illuminate the protective function of LDR on kidney damage caused by diabetes mellitus (DM). Methods: The healthy and right age C57BL/6J mice were divided into 4 groups including control, DM, LDR and DM/LDR. The mice in DM and DM/LDR groups were injected intraperitoneally with STZ to set up DM models. The mice in DM/LDR and LDR groups were irradiated with 25 mGy X-rays every other day for 4 weeks. The changes of blood glucose level, urine index level and the morphology of glomerular were detected at 2, 4, 8, 12, 16 weeks after radiation. Results: The blood glucose levels of mice in DM and DM/LDR groups after STZ-induced DM model preparation were higher than those in LDR and control groups (P<0.05). After treated with LDR for 2 weeks, the blood glucose level in DM/LDR group was supressed and significantly lower than that in DM group (P<0.05). Moreover the the change had been kept to 16 weeks. In addition, compared with DM group, the level of urine micro albumin(MALB) in DM/LDR group was decreased and the urine creatinine (Cre) level was increased. Compared with DM group, the morphological results showed that the glomerular mesangial expansion and mesangial cell proliferation were significantly supressed in DM/LDR group (P<0.05). Conclusion: LDR can promote the decease of blood glucose level efficiently, relief the change of kidney function, supress and delay the pathological changes of DN. (authors)

Role of endoplasmic reticulum stress in 12/15-lipoxygenase-induced retinal microvascular dysfunction in a mouse model of diabetic retinopathy.

Science.gov (United States)

Elmasry, Khaled; Ibrahim, Ahmed S; Saleh, Heba; Elsherbiny, Nehal; Elshafey, Sally; Hussein, Khaled A; Al-Shabrawey, Mohamed

2018-05-01

Our earlier studies have established the role of 12/15-lipoxygenase (LO) in mediating the inflammatory reaction in diabetic retinopathy. However, the exact mechanism is still unclear. The goal of the current study was to identify the potential role of endoplasmic reticulum (ER) stress as a major cellular stress response in the 12/15-LO-induced retinal changes in diabetic retinopathy. We used in vivo and in vitro approaches. For in vivo studies, experimental diabetes was induced in wild-type (WT) mice and 12/15-Lo (also known as Alox15) knockout mice (12/15-Lo -/- ); ER stress was then evaluated after 12-14 weeks of diabetes. We also tested the effect of intravitreal injection of 12-hydroxyeicosatetraenoic acid (HETE) on retinal ER stress in WT mice and in mice lacking the catalytic subunit of NADPH oxidase, encoded by Nox2 (also known as Cybb) (Nox2 -/- mice). In vitro studies were performed using human retinal endothelial cells (HRECs) treated with 15-HETE (0.1 μmol/l) or vehicle, with or without ER stress or NADPH oxidase inhibitors. This was followed by evaluation of ER stress response, NADPH oxidase expression/activity and the levels of phosphorylated vascular endothelial growth factor receptor-2 (p-VEGFR2) by western blotting and immunoprecipitation assays. Moreover, real-time imaging of intracellular calcium (Ca 2+ ) release in HRECs treated with or without 15-HETE was performed using confocal microscopy. Deletion of 12/15-Lo significantly attenuated diabetes-induced ER stress in mouse retina. In vitro, 15-HETE upregulated ER stress markers such as phosphorylated RNA-dependent protein kinase-like ER-regulated kinase (p-PERK), activating transcription factor 6 (ATF6) and protein disulfide isomerase (PDI) in HRECs. Inhibition of ER stress reduced 15-HETE-induced-leucocyte adhesion, VEGFR2 phosphorylation and NADPH oxidase expression/activity. However, inhibition of NADPH oxidase or deletion of Nox2 had no effect on ER stress induced by the 12/15-LO

Diabetic db/db mice do not develop heart failure upon pressure overload: a longitudinal in vivo PET, MRI, and MRS study on cardiac metabolic, structural, and functional adaptations.

Science.gov (United States)

Abdurrachim, Desiree; Nabben, Miranda; Hoerr, Verena; Kuhlmann, Michael T; Bovenkamp, Philipp; Ciapaite, Jolita; Geraets, Ilvy M E; Coumans, Will; Luiken, Joost J F P; Glatz, Jan F C; Schäfers, Michael; Nicolay, Klaas; Faber, Cornelius; Hermann, Sven; Prompers, Jeanine J

2017-08-01

Heart failure is associated with altered myocardial substrate metabolism and impaired cardiac energetics. Comorbidities like diabetes may influence the metabolic adaptations during heart failure development. We quantified to what extent changes in substrate preference, lipid accumulation, and energy status predict the longitudinal development of hypertrophy and failure in the non-diabetic and the diabetic heart. Transverse aortic constriction (TAC) was performed in non-diabetic (db/+) and diabetic (db/db) mice to induce pressure overload. Magnetic resonance imaging, 31P magnetic resonance spectroscopy (MRS), 1H MRS, and 18F-fluorodeoxyglucose-positron emission tomography (PET) were applied to measure cardiac function, energy status, lipid content, and glucose uptake, respectively. In vivo measurements were complemented with ex vivo techniques of high-resolution respirometry, proteomics, and western blotting to elucidate the underlying molecular pathways. In non-diabetic mice, TAC induced progressive cardiac hypertrophy and dysfunction, which correlated with increased protein kinase D-1 (PKD1) phosphorylation and increased glucose uptake. These changes in glucose utilization preceded a reduction in cardiac energy status. At baseline, compared with non-diabetic mice, diabetic mice showed normal cardiac function, higher lipid content and mitochondrial capacity for fatty acid oxidation, and lower PKD1 phosphorylation, glucose uptake, and energetics. Interestingly, TAC affected cardiac function only mildly in diabetic mice, which was accompanied by normalization of phosphorylated PKD1, glucose uptake, and cardiac energy status. The cardiac metabolic adaptations in diabetic mice seem to prevent the heart from failing upon pressure overload, suggesting that restoring the balance between glucose and fatty acid utilization is beneficial for cardiac function. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions

Resistin: A Potential Biomarker for Periodontitis Influenced Diabetes Mellitus and Diabetes Induced Periodontitis

Directory of Open Access Journals (Sweden)

Archana Devanoorkar

2014-01-01

Full Text Available Biomarkers are highly specific and sensitive indicators of disease activity. Resistin is a recently discovered adipocytokine, having a potent biomarker quality. Initially resistin was thought to be produced by adipocytes alone; however, emerging evidence suggests that it is also produced in abundance by various cells of the immunoinflammatory system, indicating its role in various chronic inflammatory diseases. Data suggests that resistin plays a role in obesity, insulin resistance, cardiovascular diseases, and periodontitis. Resistin derived its name from the original observation that it induced insulin resistance (resist-in: resist insulin in mice and is downregulated in mature murine adipocytes cultured in the presence of insulin sensitizing drugs like thiazolidinediones. It is well recognized that obesity, is associated with insulin resistance and diabetes. A three-way relationship has been established between diabetes, obesity and periodontitis. Recent evidence also suggests an association between obesity and increased risk for periodontitis. Our previous research showed incremental elevation of resistin with periodontal disease activity and a reduced level of resistin, after periodontal therapy. Thus resistin would be one of the molecular links connecting obesity, periodontitis, and diabetes and may serve as a marker that links periodontal disease with other systemic diseases. A Medline/PubMed search was carried out for keywords “Diabetes Mellitus,” “Periodontitis,” and “Resistin,” and all relevant research papers from 1990 in English were shortlisted and finalized based on their importance. This review provides an insight into the biological action of resistin and its possible role in periodontitis influenced diabetes mellitus and diabetes induced periodontitis.

Daintain/AIF-1 (Allograft Inflammatory Factor-1) accelerates type 1 diabetes in NOD mice

Energy Technology Data Exchange (ETDEWEB)

Zhao, Yan-Ying, E-mail: biozyy@163.com [College of Life Science and Technology, Southwest University for Nationalities, Chengdu 610041 (China); Huang, Xin-Yuan [College of Life Science and Technology, Hubei Engineering University, Xiaogan 432000 (China); Chen, Zheng-Wang [Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China)

2012-10-26

Highlights: Black-Right-Pointing-Pointer Daintain/AIF-1 is over-expressed in the blood of NOD mice suffering from insulitis. Black-Right-Pointing-Pointer Daintain/AIF-1 stimulates white blood cell proliferation in NOD mice. Black-Right-Pointing-Pointer Daintain/AIF-1 increases blood glucose levels and triggers type 1 diabetes. Black-Right-Pointing-Pointer Daintain/AIF-1 accelerates insulitis, while its antibody prevents insulitis. Black-Right-Pointing-Pointer Daintain/AIF-1 enhances the levels of nitric oxide in the pancreases of NOD mice. -- Abstract: A large body of experimental evidence suggests that cytokines trigger pancreatic {beta}-cell death in type 1 diabetes mellitus. Daintain/AIF-1 (Allograft Inflammatory Factor-1), a specific marker for activated macrophages, is accumulated in the pancreatic islets of pre-diabetic BB rats. In the present study, we demonstrate that daintain/AIF-1 is released into blood and the levels of daintain/AIF-1 in the blood of type 1 diabetes-prone non-obese diabetic (NOD) mice suffering from insulitis are significantly higher than that in healthy NOD mice. When injected intravenously into NOD mice, daintain/AIF-1 stimulates white blood cell proliferation, increases the concentrations of blood glucose, impairs insulin expression, up-regulates nitric oxide (NO) production in pancreases and accelerates diabetes in NOD mice, while the antibody against daintain/AIF-1 delays or prevents insulitis in NOD mice. These results imply daintain/AIF-1 triggers type 1 diabetes probably via arousing immune cells activation and induction of NO production in pancreas of NOD mice.

Evaluation of Porcine Pancreatic Islets Transplanted in the Kidney Capsules of Diabetic Mice Using a Clinically Approved Superparamagnetic Iron Oxide (SPIO) and a 1.5T MR Scanner

International Nuclear Information System (INIS)

Kim, Hoe Suk; Kim, Hyoung Su; Park, Kyong Soo; Moon, Woo Kyung

2010-01-01

To evaluate transplanted porcine pancreatic islets in the kidney capsules of diabetic mice using a clinically approved superparamagnetic iron oxide (SPIO) and a 1.5T MR scanner. Various numbers of porcine pancreatic islets labeled with Resovist, a carboxydextran-coated SPIO, were transplanted into the kidney capsules of normal mice and imaged with a 3D FIESTA sequence using a 1.5T clinical MR scanner. Labeled (n = 3) and unlabeled (n = 2) islets were transplanted into the kidney capsules of streptozotocin-induced diabetic mice. Blood glucose levels and MR signal intensities were monitored for 30 days post-transplantation. There were no significant differences in viability or insulin secretion between labeled and unlabeled islets. A strong correlation (γ 2 > 0.94) was evident between the number of transplanted islets and T 2 relaxation times quantified by MRI. Transplantation with labeled or unlabeled islets helped restore normal sustained glucose levels in diabetic mice, and nephrectomies induced the recurrence of diabetes. The MR signal intensity of labeled pancreatic islets decreased by 80% over 30 days. The transplantation of SPIO-labeled porcine islets into the kidney capsule of diabetic mice allows to restore normal glucose levels, and these islets can be visualized and quantified using a 1.5T clinical MR scanner