达格列净促进高脂诱导肥胖小鼠肝脏脂肪酸氧化的初步机制研究

Preliminary mechanism of Dapagliflozin promoting fatty acid oxidation in liver of obese mice induced by high fat

摘要:

目的 探讨达格列净对高脂诱导肥胖小鼠肝脏脂代谢的影响及初步作用机制。方法 将16只高脂饮食12周的C57BL/6肥胖小鼠分为达格列净组和模型对照组（OC组），每组8只，另选取8只低脂饮食小鼠为正常对照组（NC组）。达格列净组按照10 mg/（kg·d）给予连续3周灌胃，OC组和NC组分别给予等量生理盐水。测量各组小鼠体重、血糖、葡萄糖耐量及胰岛素耐量；酶联免疫吸附试验检测小鼠血清胰岛素及脂质水平；实时荧光定量聚合酶链反应和Western blotting分别检测肝脏沉默信息调节因子2相关酶1（SIRT1）、过氧化物酶体增殖物激活受体γ共激活因子-1α（PGC-1α）及肉碱棕榈酰转移酶1A（CPT1A） mRNA和蛋白表达。结果 实验后达格列净组小鼠体重和空腹血糖水平较实验前下降最明显（P <0.05）。实验后达格列净组小鼠血浆胰岛素水平、葡萄糖耐量曲线下面积、胰岛素耐量曲线下面积及HOMA胰岛素抵抗指数均低于OC组（P <0.05）。与OC组比较，达格列净组小鼠血清甘油三酯和胆固醇水平均降低（P <0.05）。与OC组比较，达格列净组小鼠肝脏甘油三酯、胆固醇及肝脏重量均降低（P <0.05）。肝脏PGC-1α、SIRT1、CPT1A mRNA和蛋白相对表达量均升高（P <0.05）。结论 达格列净可能通过激活肝脏SIRT1/PGC-1α/CPT1A通路促进肥胖小鼠的肝脏脂肪酸氧化，减少肝脏脂肪蓄积，改善胰岛素抵抗。

Abstract:

Objective To investigate the effects of Dapagliflozin on liver lipid metabolism and its primary mechanism in adipose-induced obesity mice.Methods Sixteen obese C57BL/6 mice were divided into two groups,which were model control group (OC group) and Dapagliflozin group, with 8 mice in each group. In addition, 8 low-fat diet were selected as normal control group (NC group). Dapagliflozin group was given 10 mg/(kg·d) intragastric administration for 3 weeks, while NC and OC groups were given the same amount of normal saline. The body weight, blood glucose, glucose tolerance, and insulin tolerance of mice in each group were detected. Serum insulin and lipid levels were detected by ELISA. The mRNA and protein levels of silencing information regulator 2 related enzyme 1 (SIRT1), deacetylation of peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), and carnitine palmityl transferase 1A (CPT1A) in liver were detected by RT-PCR and Western blotting.Results Body weight and fasting plasma glucose in Dapagliflozin group decreased after experiment (P < 0.05). Compared with OC group, the body weight, fat content, fasting plasma glucose, serum insulin, serum triglyceride, and serum cholesterol decreased (P < 0.05); the area under glucose tolerance curve and insulin tolerance curve decreased (P < 0.05); liver weight, liver triglyceride level, and liver cholesterol level decreased (P < 0.05); the mRNA expression levels of SIRT1, PGC-1α, and CPT1A in liver increased (P < 0.05); the protein expression levels of SIRT1, CPT1A, and PGC-1α in liver increased (P < 0.05).Conclusion Dapagliflozin may enhance hepatic fatty acid oxidation, decrease hepatic fat accumulation, and improve insulin resistance in obese mice by activating SIRT1/ PGC-1α /CPT1A pathway.