Project description:Population based studies have established that androgen deficiency in males correlates with type 2 diabetes, visceral adiposity, and metabolic syndrome. Androgen therapy has been investigated as a possible treatment regime to combat these disorders. However, the molecular mechanism of androgen effects on these diseases still remain poorly understood. The zucker diabetic fatty (ZDF) rat, containing a mutation in the leptin receptor, is a well-investigated model of obesity and type 2 diabetes. Male rats are characterized as androgen deficient and spontaneously develop obese, hyperlipidemia, hyperglycemia and hyperinsulinemia. In this study, we used ZDF male rats as a model of metabolic syndrome to investigate the effects of testosterone administration on the development of the metabolic conditions. Methods: Male ZDF rats at six week of age were randomly divided into two groups and administered testosterone undecanoate(TU) or vehicle alone every three days for three weeks. After three weeks, overnight fasted blood glucose and insulin concentrations were significantly higher and glucose tolerance and insulin sensitivity were impaired in TU treated ZDF rats compared to vehicle controls. Moreover, increased serum triglycerides and VLDL were observed in TU treated rats. To further explore the observed metabolic changes in TU treated ZDF rats, whole-genome microarray analysis were performed on isolated liver mRNA. Results: Array analysis revealed that many hepatic lipogenic genes were increased in male ZDF rat livers treated with TU. Interestingly, SREBP-1c, a key transcriptional activator of lipogenic genes and PGC-1 , an activator of SREBP-1c were induced while small heterodimer partner, a transcriptional inhibitor of lipogenic genes was suppressed by TU treatment. Exploring signaling pathways for these effects, we observed that the hepatic activated forms of STAT3 and AMPK, two known inhibitors of hepatic lipogenesis, were decreased in TU treated rat. Moreover, we observed that DHT could block the induction of STAT3 and AMPK phosphorylation in treated primary human hepatocytes. Preliminarily, in the leptin receptor positive zucker diabetic lean male rats, we observed that TU treatment has an oppose effect on the hepatic lipogenic genes, suggesting that hepatic leptin signaling may influence androgen signaling. Further insight into the relationship between androgen deficiency and the leptin system may help improve treatment of the metabolic syndrome. Population based studies have established that androgen deficiency in males correlates with type 2 diabetes, visceral adiposity, and metabolic syndrome. Androgen therapy has been investigated as a possible treatment regime to combat these disorders. However, the molecular mechanism of androgen effects on these diseases still remain poorly understood. The zucker diabetic fatty (ZDF) rat, containing a mutation in the leptin receptor, is a well-investigated model of obesity and type 2 diabetes. Male rats are characterized as androgen deficient and spontaneously develop obese, hyperlipidemia, hyperglycemia and hyperinsulinemia. In this study, we used ZDF male rats as a model of metabolic syndrome to investigate the effects of testosterone administration on the development of the metabolic conditions. Two-condition experiment. (1) lean ZDF rats (control) vs. lean ZDF rats (testosterone treated). (2) obese ZDF rats (control) vs. obese ZDF rats (testosterone treated). Biological replicates: 4 control replicates, 4 treated replicates.

Project description:Population based studies have established that androgen deficiency in males correlates with type 2 diabetes, visceral adiposity, and metabolic syndrome. Androgen therapy has been investigated as a possible treatment regime to combat these disorders. However, the molecular mechanism of androgen effects on these diseases still remain poorly understood. The zucker diabetic fatty (ZDF) rat, containing a mutation in the leptin receptor, is a well-investigated model of obesity and type 2 diabetes. Male rats are characterized as androgen deficient and spontaneously develop obese, hyperlipidemia, hyperglycemia and hyperinsulinemia. In this study, we used ZDF male rats as a model of metabolic syndrome to investigate the effects of testosterone administration on the development of the metabolic conditions. Methods: Male ZDF rats at six week of age were randomly divided into two groups and administered testosterone undecanoate(TU) or vehicle alone every three days for three weeks. After three weeks, overnight fasted blood glucose and insulin concentrations were significantly higher and glucose tolerance and insulin sensitivity were impaired in TU treated ZDF rats compared to vehicle controls. Moreover, increased serum triglycerides and VLDL were observed in TU treated rats. To further explore the observed metabolic changes in TU treated ZDF rats, whole-genome microarray analysis were performed on isolated liver mRNA. Results: Array analysis revealed that many hepatic lipogenic genes were increased in male ZDF rat livers treated with TU. Interestingly, SREBP-1c, a key transcriptional activator of lipogenic genes and PGC-1 , an activator of SREBP-1c were induced while small heterodimer partner, a transcriptional inhibitor of lipogenic genes was suppressed by TU treatment. Exploring signaling pathways for these effects, we observed that the hepatic activated forms of STAT3 and AMPK, two known inhibitors of hepatic lipogenesis, were decreased in TU treated rat. Moreover, we observed that DHT could block the induction of STAT3 and AMPK phosphorylation in treated primary human hepatocytes. Preliminarily, in the leptin receptor positive zucker diabetic lean male rats, we observed that TU treatment has an oppose effect on the hepatic lipogenic genes, suggesting that hepatic leptin signaling may influence androgen signaling. Further insight into the relationship between androgen deficiency and the leptin system may help improve treatment of the metabolic syndrome. Population based studies have established that androgen deficiency in males correlates with type 2 diabetes, visceral adiposity, and metabolic syndrome. Androgen therapy has been investigated as a possible treatment regime to combat these disorders. However, the molecular mechanism of androgen effects on these diseases still remain poorly understood. The zucker diabetic fatty (ZDF) rat, containing a mutation in the leptin receptor, is a well-investigated model of obesity and type 2 diabetes. Male rats are characterized as androgen deficient and spontaneously develop obese, hyperlipidemia, hyperglycemia and hyperinsulinemia. In this study, we used ZDF male rats as a model of metabolic syndrome to investigate the effects of testosterone administration on the development of the metabolic conditions.

Project description:In previous in vitro study, we reported potential mechanism of cholesterol-lowering effect of Lactobacillus brevis119-2 (119-2) isolated from turnip M-bM-^@M-^\Tsuda kabuM-bM-^@M-^] is due to incorporation of cholesterol into 119-2 cell. In this study, we analyzed serum cholesterol and hepatic gene expression of Sprague-Dawley (SD) rat fed diet containing cholesterol with or without 119-2 for 2 weeks, to evaluate the cholesterol-lowering effect of 119-2 in vivo. Serum cholesterol of SD rat fed diet with 119-2 significantly decreased compared to SD rat fed diet without 119-2, and both viable and dead 119-2 indicated the effect. The result of hepatic gene analysis using DNA microarray suggested that potential mechanism of the cholesterol-lowering effect of 119-2 in vivo is inhibiting the activity of 3-hydroxy-3-methylglutaryl-CoA reductase by Insig (insulin induced gene) that is endoplasmic reticulum membrane protein, and catabolizing cholesterol to bile acid by Cyp7a1 (cytochrome P450 a1) that is the rate-limiting enzyme in the synthesis of bile acid from cholesterol. In addition, we concluded feeding 119-2 decreased serum low density lipoprotein (LDL) cholesterol by overexpression of Ldlr (LDL receptor gene). On the other hand, feeding Lactobacillus acidophilus ATCC43121 (ATCC) increased high density lipoprotein (HDL) cholesterol by over expression of Abca1 (ATP binding cassette sub-family A member 1 gene) and Angplt3 (Angiopoietin-like 3). These results suggested that 119-2 decrease the risk of atherosclerosis by serum cholesterol-lowering effect and improving effect of fatty liver and the LH (LDL cholesterol / HDL cholesterol) ratio. Lactobacillus brevis119-2 (119-2) was isolated from turnip M-bM-^@M-^\Tsuda kabuM-bM-^@M-^] harvested in Matsue city, Shimane Prefecture, Japan, and was stored at Shimane Institute for industrial Technology. Male Jcl: SD rat (4 weeks of age) were obtained from CLEA Japan, Inc. (Tokyo, Japan). Rats were maintained under controlled environmental conditions (temperature 23 M-BM-1 3 M-KM-^ZC, relative humidity 55% M-BM-1 25%, 12/12hr light - dark cycle) and given food and water ad libitum. All rats were acclimated 1 week prior to the experiment. Two groups of 11 rats each were treated respective group diets for 2weeks. Control group was fed high-cholesterol diet containing 10 g cholesterol/kg, 5 g cholic acid/kg, 985 g mouse & rat & rabbit diet (CRF-1) /kg obtained from Oriental yeast Co., Ltd (Tokyo, Japan). The other group was fed same highcholesterol diet with 10 g freeze-dried viable 119-2 /kg. This study and all procedures were approved by regulations and code of ethics in experimental animals Chitose Japan Food Research Laboratories.

Dataset Information

SRNA sequencing of liver from lean rats and ZDF rats treated with vehicle or colesevelam

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets