葱白提取物诱导PGC-1α活化非酒精性脂肪性肝病大鼠线粒体代谢的研究

Study of fistular onion stalk extract activating mitochondrial metabolism on non-alcoholic fatty liver disease rats by inducing PGC-1α

关键词:  葱白提取物  非酒精性脂肪性肝病  线粒体代谢  线粒体呼吸链

Key words:  fistular onion stalk extract  non-alcoholic fatty liver disease  mitochondrial metabolism  mitochondrial respiratory chain

摘要:

[目的] 探讨葱白提取物通过诱导过氧化物酶体增殖物受体γ辅助激活因子1α（PGC-1α）活化非酒精性脂肪性肝病（NAFLD）大鼠线粒体代谢的机制。[方法] 采用高脂饮食造模，将48只雄性大鼠随机分为空白组、模型组、葱白组、空转组、转染组、转染加葱白组，并运用小干扰RNA技术抑制PGC-1α的表达，实验检测血清总胆固醇（TC）、三酰甘油（TG）、高密度脂蛋白（HDL-C）、低密度脂蛋白（LDL-C）水平，实时荧光定量聚合酶链式反应（Realtime PCR）检测大鼠肝脏乙酰辅酶A羧化酶（ACCase）、肉毒碱棕榈酰基转移酶-1（CPT-1）mRNA的表达情况，观察肝脏组织病理改变，蛋白质印迹法（Western Blot）验证线粒体合成相关蛋白PGC-1α、核呼吸因子1（NRF-1）、线粒体转录因子A（TFAM）和线粒代谢相关蛋白细胞色素c氧化酶B（COX-B）、细胞色素c氧化酶合成蛋白（SCOX）、中链酰基辅酶A脱氢酶（MCAD）的表达。[结果] 与空白组相比，模型组大鼠肝脏出现明显脂肪变性；葱白提取物可降低TC、TG、LDL-C水平，升高HDL-C水平（P<0.01），同时ACCase mRNA表达水平降低（P<0.01），CPT-1 mRNA表达水平升高（P<0.01），缓解脂肪肝变性，并上调PGC-1α、NRF-1、TFAM、COX-B、SCOX、MCAD蛋白的表达（P<0.01）。同时，与模型组相比，在转染加葱白组的大鼠中上述检测指标，未见明显变化。[结论] PGC-1α是葱白提取物治疗NAFLD的重要靶点。葱白提取物可通过上调PGC-1α改善NAFLD模型大鼠线粒体功能，维持线粒体呼吸链稳定，从而起到活化线粒体代谢以及改善脂肪肝变性的效果。

Abstract:

[Objective] To investigate the mechanism of fistular onion stalk extract activating mitochondrial metabolism on non-alcoholic fatty liver disease(NAFLD) rats by inducing PGC-1α. [Methods] High fat feed was used to produce NAFLD rat model. Forty-eight male rats were randomly divided into 6 groups including normal group,model group,fistular onion group,transfection group,blank transfection group,and fistular onion transfection group. We used SiRNA technology to inhibit the expression of PGC-1α,detected levels of serum TC,TG,HDL-C,LDL-C. Realtime PCR was used to detect mRNA expressions of acetyl-coa carboxylase (ACCase) and carnitine palmityl transferase-1 (CPT-1) in rat liver,then we observed the pathological changes in liver tissue,and tested the synthesized mitochondrial proteins expression of PGC-1α,NRF-1,TFAM and the mitochondrial metabolism proteins COX-B,SCOX,MCAD by Western Blot. [Results] Compared with the blank group,the model group showed significant steatosis in the liver. Compare to the model group,fistular onion stalk extract can reduce levels of serum TC,TG,LDL-C,elevate HDL-C(P<0.01),decrease the expression level of ACCase mRNA (P<0.01) and increase the expression level of CPT-1 mRNA (P<0.01),relieve liver steatosis,and up-regulated the protein expression of PGC-1α,NRF-1,TFAM,COX-B,SCOX,MCAD (P<0.01). At the same time,compared with the model group,there were no significant changes in the above detection indexes in the fistular onion transfection group. [Conclusion] PGC-1 α is an important therapeutic target of fistular onion stalk extract in the treatment of NAFLD. Fistular onion stalk extract can improve mitochondrial function and maintain mitochondrial respiratory chain stability in NAFLD model rats by up-regulating PGC-1α,thus activating mitochondrial metabolism and improving fatty liver degeneration.