不同脂肪含量饮食对小鼠脂肪细胞肥胖相关基因表达的影响

Effects of the dietary fat on adipose-associated gene expressions of adipocytes in mice

目的探讨饮食中的脂肪含量对小鼠营养性肥胖症的作用。方法将40只C57BL／6小鼠随机分为4组，分别喂养含量不同的猪油餐。第1—4组猪油所提供热量分别为0％、20％、40％和60％，单位重量饲料的总热量不变。第7周末测定小鼠的血糖、血脂等指标，并取肝脏和肾脏作病理切片，取白色脂肪组织做基因芯片分析。结果第4组小鼠的体重、血糖、血脂、胰岛素、肥胖指数与第1组小鼠比较有统计学差异；肝细胞和。肾近曲小管细胞有大量脂质沉积；脂肪细胞中的肥胖相关基因有13个的表达是2倍以上上调，有8个的表达是2倍以下下调。结论高脂饮食通过调节小鼠脂肪细胞中刺激食欲的基因、抑制食欲的基因和能量消耗相关基因使小鼠发生肥胖、高胰岛素血症和脂质代谢异常。

Objective To observe the effect of dietary fat on diet-induced obesity in mice. Methods Forty 3-week-old male C57BL/6 mice were randomly divided into four groups （1-4） fed with diets of different amounts of lard [0%, 20%, 40% and 60% of total energy （kcal）]. Plasma glucose, lipids, insulin and other parameters were measured after 7 weeks. Moreover, the livers and kidneys were taken for histopathological evaluation and white fatty tissues were taken to analyse adipose-associated gene expressions using gene chip technology. Results There were statistically significant differences in weight, blood glucose, triglyceride, total cholesterol, high-density lipoprotein-cholesterol, low-density lipoproteincholesterol, insulin and adiposity index between the 1st and the 4th group. Obvious lipid deposition in the liver and kidney sections was found in the 4th group. Thirteen adipose-associated genes were up-regulated in expression and 8 genes down-regulated by over 2-fold in the adipocytes of the 4th group. Conclusions The mice fed with high-fat diet developed evident obesity, insulin resistance and abnormal lipid metabolism. The obesity was induced by high-fat diet via regulating some of the orexigenic genes, anorexigenic genes and the genes involved in energy expenditure in adipocytes of mice.