有氧运动和白藜芦醇对非酒精性脂肪肝大鼠下丘脑Leptin-AMPK-mTOR通路相关蛋白的调节机制

Effcets and possible mechanisms of aerobic exercise and resveratrol on Leptin-AMPK-mTOR pathway-related proteins in hypothalamus of nonalcoholic fatty liver rats

目的:研究有氧运动和(或)白藜芦醇干预对NAFLD大鼠下丘脑瘦素抵抗介导的AMPK-mTOR信号通路变化的相关机制。方法:健康雄性SD大鼠分为正常对照组(C)、NAFLD高脂组(H)、NAFLD高脂运动组(HE)、NAFLD高脂给予白藜芦醇组(HR)、NAFLD高脂运动给予白藜芦醇组(HRE),运动组进行游泳训练,给予白藜芦醇组按照45 mg/kg/day进行干预。大鼠于冰面上迅速剥离脑组织,分离下丘脑。ELISA方法检测下丘脑NPY水平,QRT-PCR检测下丘脑LP-Rb、SOCS3、PGC1α、mTOR、S6K1 mRNA表达;Western-blot方法检测下丘脑SOCS3、AMPKα、mTOR、S6K1的蛋白表达。结果:1)模型组大鼠下丘脑NPY水平出现明显上升;HR、HE、HRE组与H组相比,NPY显著的降低(P<0.01),其中HE组下降最为明显,HR次之,HRE组NPY水平趋近于正常对照组;2)模型各组大鼠的下丘脑SOCS3 mRNA的表达均出现了不同程度的增加;LP-Rb mRNA的表达H组与C组相比分别降低将近0.66倍(P<0.01);3)高脂模型组单纯运动引起了下丘脑AMPKα蛋白的高表达,改善效果明显优于联合干预组,但对下游mTOR、S6K1蛋白表达的抑制作用,联合干预组抑制效果明显的优于单一干预。结论:改善非酒精性脂肪肝大鼠中枢瘦素抵抗单纯就瘦素受体的表达而言,高脂模型组中单纯运动效果优于单纯给予Res或联合干预。

Objective:To study the mechanisms of exercise training and resveratrol intervention on the changes of AMPK-mTOR signaling pathway in the hypothalamic leptin resistance of NAFLD rats.Methods:Healthy male Sprague-Dawley rats were divided into normal control group(C),NAFLD high-fat group(H),NAFLD high-fat&exercise group(HE),NAFLD high-fat&resveratrol group(HR),NAFLD high-fat&exercise&resveratrol group(HRE).The exercise groups performed swimming training and the resveratrol groups were intervened according to 45 mg/kg/day.The rat was quickly stripped of brain tissue on the ice and the hypothalamus was isolated.The NPY level of hypothalamus was detected by ELISA.The expressions of LP-Rb,SOCS3,PGC1α,mTOR and S6K1 mRNA in hypothalamus were detected by QRT-PCR.SOCS3,AMPKα,mTOR and S6K1 protein expression were detected by Western-blot method.Results:1)The NPY level of the hypothalamus in the model group increased significantly.Compared with the H group,the NPY was significantly decreased in the HR,HE,HRE group(P<0.01),and the HE group was the most obvious,followed by the HR.The NPY level in the HRE group approached the normal control group;2)The expression of SOCS3 mRNA in the hypothalamus of all groups in the model group showed different degrees of increase;LP-Rb mRNA expression in the H group,decreased by nearly 0.66 times compared with the C group(P<0.01);3)For the normal diet model group,8 weeks of exercise training and combined Res intervention could significantly up-regulate the protein expression of AMPKαin hypothalamic.For high fat model group,simple exercise caused high expression of AMPKαproteins in the hypothalamus.The improvement effect was better than that of the combined intervention group,but the inhibition effect of downstream mTOR and S6K1 protein expression in combined intervention groups is obviously better than the single stem.Conclusion:To improve the central leptin resistance in rats with nonalcoholic fatty liver disease,the terms of expression of leptin receptor showed that,the effect of simply giving Res in the normal diet model group is better than the simple exercise or combined intervention;the simple exercise effect in the high fat model group is better than simply giving Res or joint intervention.