利拉鲁肽对RNAi介导的脂联素基因抑制ApoE基因敲除小鼠糖脂代谢的影响

目的 探讨利拉鲁肽对脂联素基因表达缺陷的ApoE基因敲除(ApoE-/-)小鼠糖脂代谢的影响.方法 采用静脉葡萄糖耐量试验(IVGTT)评价利拉鲁肽的量效关系.利用扩展高胰岛素钳夹技术评价各组小鼠糖脂代谢和胰岛素敏感性变化.结果 在IVGTT中,利拉鲁肽1 mg/kg组,糖负荷后5、15和30 min血糖值均明显低于其它剂量组(均P＜0.01),而血浆胰岛素水平在5、15 min均明显高于其他3组(均P＜0.01).联合注射利拉鲁肽和脂联素RNAi腺病毒组体重、空腹血糖、血浆游离脂肪酸、总胆固醇、甘油三酯、血浆胰岛素和低密度脂蛋白胆固醇(LDL-C)水平显著低于脂联素RNAi腺病毒组(P＜0.05或P＜0.01),而高密度脂蛋白胆固醇(HDL-C)则明显高于脂联素RNAi组(P＜0.05).钳夹稳态时,脂联素RNAi组血浆胰岛素明显高于利拉鲁肽组(P＜0.01),游离脂肪酸、总胆固醇、甘油三酯虽被抑制,但仍明显高于利拉鲁肽组(P＜0.05).利拉鲁肽组葡萄糖输注率(GIR)则明显高于脂联素RNAi组(P＜0.01).钳夹结束时,脂联素RNAi组葡萄糖清除率(GRd)明显低于利拉鲁肽组(P＜0.01),而肝糖输出率则明显高于利拉鲁肽组(P＜0.01).结论 长期的利拉鲁肽干预上调了脂联素基因表达缺陷ApoE-/-小鼠血浆脂联素水平,并改善了其胰岛素抵抗.

Effects of liraglutide on glucose-lipid metabolism in ApoE-/-mice with RNAi-mediated adiponectin gene inhibition

Objective To investigate the effects of liraglutide on glucose-lipid metabolism in ApoE-/-mice with RNAi-mediated adiponectin gene inhibition. Methods The dose-effective relationship of liraglutide was evaluated by intravenous glucose tolerance test (IVGTT), and the insulin sensitivity and glucose-lipid metabolism were assessed by the hyperinsulinemic-euglycemic clamp technique using 3-3 H]-glucose as a tracer. Results In the IVGTT, blood glucose was significantly lower in the 1 mg/kg liraglutide group than that in other groups ( all P＜0. 01 ) at the points of 5, 15, and 30 min after glucose load. However, plasma insulin was significantly higher at the points of 5 and 15 min (all P＜0. 01 ). Fasting blood glucose (FBG), body weight, free fatty acids (FFA),total cholesterol, triglycerides, low-density lipoprotein-cholesterol ( LDL-C), and fasting plasma insulin in ApoE-/-mice with co-injection of liraglutide and adiponectin shRNA adenovirus ( HEA group ) were significantly lower than those in ApoE-/-mice with adiponectin shRNA adenovirus injection ( ADI group, P＜0. 05 or P＜0. 01 ). However,high-density lipoprotein-cholesterol (HDL-C) was significantly higher than the latter (P＜0. 05 ). During the steady-state of clamp, plasma insulin in ADI group was significantly higher than that in HEA group (P＜0. 01 ). Although FFA, total cholesterol, and triglycerides were suppressed in all groups, they were still higher in ADI group than those in HEA group (P＜0. 05). Glucose infusion rate (GIR) in HEA group were significantly higher than that in ADI group ( P ＜ 0. 01 ). At the end of clamp, glucose disappearance rate ( GRd ) was significantly lower, and hepatic glucose production significantly higher in ADI group than those in HEA group (P＜0.01 ). Conclusion Administration of liraglutide may ameliorate insulin resistance via increasing plasma adiponectin level in ApoE-/-mice with RNAi-mediated adiponectin gene inhibition.