非酒精性脂肪肝病大鼠肝脏PGC-1αmRNA表达的变化

Over-expression of PGC-1α genes in the liver of rats with induced by high-fat diet nonalcoholic fatty liver disease

目的观察非酒精性脂肪肝病(NAFLD)大鼠肝组织过氧化物酶体增殖物激活受体γ辅激活因子1α(PGC-1α)mRNA的动态表达,探讨PGC-1α在大鼠NAFLD发病中的作用。方法雄性SD大鼠42只随机分为高脂组及对照组,高脂组给予高脂饲料喂养,对照组以普通饲料饲养,分批于实验第2、4、8周各处死7只大鼠,检测血清中空腹血糖(FBG)及空腹胰岛素(FINS)并计算空腹胰岛素抵抗指数(FIRI),反转录PCR(RT-PCR)法检测肝脏PGC-1αmRNA表达。结果高脂组大鼠肝脏PGC-1αmRNA表达量在第4周及第8周较同期对照组明显增加(P<0.01),并且随着喂养时间的延长,其值较其前期差异均有统计学意义(P<0.05,P<0.01)。高脂组8周PGC-1αmRNA水平与FBS、FINS及FIRI均呈正相关(r=0.618、0.853、0.776,P<0.01)。结论高脂饮食诱导NAFLD大鼠肝组织PGC-1α的表达随着喂养时间的延长逐渐增加,且与胰岛素抵抗密切相关。

Objective To investigate the expression of mRNA of peroxisome proliferators-activated receptor-γ coactivator-1α （PGC-1α） in the livers of rats with developing nonalcoholic fatty liver disease （NAFLD） and explore the effects of PGC-1α in pathogenesis on the model of rats with NAFLD. Methods Forty-two male SD rats were randomly divided into 2 groups： high-fat group and control group. The rats in high-fat group were fed with high-fat diet; rats in control group were fed with standard diet. At the end of 2th, 4th, 8th week, the rats were sacrificed. The levels of FBS, FINS in serum were detected, and meanwhile the fasting insulin resistance index （FIRI） was calculated. The expression of PGC-1α mRNA was detected with RT-PCR. Results The expression level of PGC-1α mRNA in livers of rats in high-fat group was significantly higher than that in control group in the 4th and 8th week （P 〈0. 01 ） and increased significantly with the time （P 〈0. 05 ,P 〈0. 01 ） ; the level of PGC-1α mRNA in high-fat group in the 8th week had positive correlation with FBS, FINS, and FIRI （ r = 0. 618, 0. 853, 0. 776, P 〈 0. 01 ）.Conclusion The expression of PGC-1 α mRNA is up-regulated in liver of NAFLD rats, and closely related to IR.