牛磺酸对肥胖大鼠甘油三酯和胆固醇代谢的影响

Effects of taurine on triglyceride and cholesterol metabolism in obese rats

中文关键词:  牛磺酸  肥胖  脂肪酸合成酶  肝脏甾醇调节元件结合蛋白1c  胆固醇7α羟化酶

英文关键词:taurine  obesity  fatty acid synthase  sterol regulatory element-binding protein-1c  cholesterol 7α-hydroxylase

中文摘要:

      目的 探讨长期经饮水方式补充牛磺酸对高脂膳食所致肥胖大鼠降脂减重作用, 对甘油三酯合成关键分子和胆固醇7α羟化酶(cholesterol 7α-hydroxylase, CYP7A1)表达调控关键分子的影响。方法 根据血清胆固醇水平和体重, SD大鼠被分为3组, 为对照组(normal, N)饲喂基础维持饲料, 肥胖组(high fat, HF)和牛磺酸组(high fat taurine, HFT)饲喂高脂饲料。N组和HF组自由饮水, 而HFT组给予牛磺酸溶液代替水, 持续12周。结果 与HF组相比, 给予牛磺酸的HFT组大鼠体重、附睾周围脂肪重量、血清总胆固醇和低密度脂蛋白胆固醇、游离脂肪酸、固醇调节元件结合蛋白-1c (sterol regulatory element-binding protein-1c, SREBP-1c)和脂肪酸合成酶(fatty acid synthase, FAS)基因表达显著降低, 粪便胆汁酸水平、脂蛋白脂肪酶(lipoprotein lipase, LPL)活性以及CYP7A1和Ser63 p-c-Jun的蛋白表达显著增加, 但肝细胞核因子4α (hepatocyte nuclear factor 4α, HNF4α)没有明显变化。结论 牛磺酸通过增加LPL活性促进血浆甘油三酯分解代谢、抑制SREBP-1c和FAS而减少甘油三酯合成; 通过激活c-Jun, 但不影响HNF4α表达的途径增强CYP7A1转录进而促进胆固醇转化为胆汁酸, 以此改善脂代谢和脂质沉积, 发挥减肥降脂作用。

英文摘要:

      Objective To explore the effects of taurine supplementation through drinking water for a long time on reducing blood fat and weight in obese rats induced by high-fat diet, and on key molecules of triglyceride synthesis and expression regulation of cholesterol 7α-hydroxylase (CYP7A1). Methods According to serum cholesterol level and body weight, SD rats were divided into three groups. The normal (N) was fed with basic maintenance diet, and the high fat (HF) and high fat taurine (HFT) were fed with high-fat diet. The rats in the N and HF groups were given free water, while those in the HFT group were given taurine solution instead of water for 12 weeks. Results Rats in the taurine-administered HFT group compared with the HF group had body weight, periepididymal fat weight, serum total cholesterol and low density lipoprotein cholesterol, free fatty acids, sterol regulatory element-binding protein-1c (SREBP-1c) and fatty acid synthase (FAS) gene expressions were significantly decreased, while the HFT group also significantly increased fecal bile acid levels, lipoprotein lipase (LPL) activity, and protein expression of CYP7A1 and Ser63 p-c-Jun, but hepatocyte nuclear factor 4α (HNF4α) was not significantly change. Conclusion Taurine can promote plasma triglyceride catabolism by increasing LPL activity, inhibit SREBP-1c and FAS, and reduce triglyceride synthesis. By activating c-Jun, but not affecting the expression of HNF4α, the transcription of CYP7A1 can be enhanced, and then cholesterol can be converted into bile acid, so as to improve lipid metabolism and lipid deposition, and play a role in reducing weight and lipid.