高脂饮食诱导胰岛素抵抗小鼠骨骼肌胰岛素信号通路相关基因表达的变化

The changes of expression of insulin signaling related genes in skeletal muscle of high fat diet-induced insulin resistant mice

目的:利用基因芯片技术研究高脂饮食诱导的胰岛素抵抗(insulin resistance,IR)小鼠骨骼肌细胞胰岛素信号通路相关基因的改变,分析其变化规律,为寻找治疗IR的潜在药物作用靶点提供理论依据。方法:选用雄性C57BL/6小鼠40只,随机分为正常饮食组(NC组)和高脂饮食组(HC组)。分别饲养16周后,采用口服糖耐量试验(oral glucose tolerance test,OGTT)检测小鼠葡萄糖耐量;ELISA检测空腹血清胰岛素值(fasting insulin,FIN)以确定胰岛素抵抗模型成功;后分离小鼠股四头肌,提取总RNA,经过荧光标记后进行基因芯片杂交,利用芯片扫描仪记录荧光信号,并通过相关软件对所得数据进行统计学分析。结果:16周高脂饮食喂养结束后,HC组小鼠体重较NC组增加25.33%(P<0.05),FIN值较NC组增加77.19%(P<0.05)。OGTT峰值出现的时间较NC组延迟,血糖值在30min后下降缓慢,且在180min血糖值仍高于基础水平。胰岛素信号通路的差异表达基因有11个。表达上调的基因有3个,表达下调的基因有8个,这些基因涉及糖代谢、脂代谢、信号转导及转录等生物学过程。结论:16周的高脂饮食可以诱发C57BL/6小鼠产生IR。HC组小鼠骨骼肌胰岛素信号相关基因发生差异表达,这些基因与IR密切相关。本研究为寻找治疗IR潜在的药物靶点提供理论依据。

Objective： To detect the related gene expressions of insulin signaling pathway in skeletal muscle of insulin resistant（IR） mice induced by high fat diet with microarray technique, to provide theoretical evidence for searching potential drug targets of IR. Method： Forty male C57BL/6 mice were randomly divided into normal diet control group （NC） and high fat diet group （HC）. After 16-week different diets, oral glucose tolerance was detected by oral glucose tolerance test（OGTT）; fasting insulin（FIN） concentration was measured by ELISA. Total RNA was extracted from quadriceps femoris, then labeled with fluorescent dye for microarray hybridization. Hybridized microarray slides were scanned to generate gene lists with corresponding fluorescence intensity data. The data were analyzed using relevant computer software. Result： After 16-week high fat diet, in HC group the weight of mice increased significantly by 25.33%（P0.05）, and insulin level increased significantly by 77.19% compared with NC group（P0.05）. The peak value of OGTT curve in HC group increased significantly compared with NC group, and the time point of OGTT peak shifted backward. Data analysis showed that 11 genes of insulin signaling pathway differentially expressed in the HC group compared with NC group, among which 3 genes were up and 8 down-regulated, which involved in glycogen metabolism, lipid metabolism, signal transduction and transcription. Conclusion： Sixteen-week high fat diet induced IR of C57BL/6 mice. Differentially expressed genes of insulin signaling pathway in HC group were relevant with IR. This study provides theoretical evidence for searching potential drug targets of IR.