涤痰汤调控PPARγ-LXR-ABCA1/ABCG1通路介导胆固醇流出改善非酒精性脂肪肝的机制研究

Mechanism of Regulating Cholesterol Outflow Mediated by PPARγ-LXR-ABCA1/ABCG1 Pathway by Ditan Decoction(涤痰汤)to Improve Nonalcoholic Fatty Liver Disease

目的探讨涤痰汤改善非酒精性脂肪肝(non-alcoholic fatty liver disease,NAFLD)的机制是否与调控过氧化物酶体增殖物激活受体γ(peroxisome proliferator-activated receptorγ,PPARγ)-肝X受体(Liver X receptor,LXR)-腺苷三磷酸结合盒转运体A1(ATP-binding transporter A1,ABCA1)/腺苷三磷酸结合盒转运体G1(ATP-binding transporter G1,ABCG1)通路介导的胆固醇流出有关。方法45只SPF大鼠分为对照组、模型组、涤痰汤组,给予高脂饮食饲养12周制备NAFLD大鼠模型,于第9周灌胃给药,分别检测各组大鼠总胆固醇(total cholesterol,TC)、甘油三酯(triacylglyceride,TG)、低密度脂蛋白胆固醇(low-density lipoprotein cholesterol,LDL-C)、高密度脂蛋白胆固醇(high-density lipoprotein cholesterol,HDL-C)、丙氨酸氨基转移酶(alanine transaminase,ALT)、天冬氨酸氨基转移(aspartate transaminase,AST)水平,HE、油红O染色观察大鼠肝脏病理形态学变化,RT-qPCR和Wes全自动蛋白质印迹定量分析系统检测PPARγ、LXR、ABCA1、ABCG1基因mRNA及蛋白表达。结果与对照组相比,模型组大鼠血清TG、TC、LDL-C、ALT、AST水平显著升高(P<0.01),HDL-C水平显著降低(P<0.05),肝细胞排列紊乱,且脂肪空泡和脂质沉积明显,肝脏PPARγ、LXR、ABCA1、ABCG1基因及蛋白表达水平显著降低(P<0.05或P<0.01);给予涤痰汤干预后,血脂紊乱得以改善,ALT、AST水平显著降低(P<0.05或P<0.01),肝细胞肿胀减轻,脂肪空泡及脂质沉积减少,肝脏PPARγ、ABCG1基因及蛋白表达水平显著升高(P<0.05或P<0.01),ABCA1蛋白表达水平显著升高(P<0.01)。结论涤痰汤可能通过调控PPARγ-LXR-ABCA1/ABCG1通路介导的胆固醇流出改善非酒精性脂肪肝。

Objective To investigate whether the mechanism of Ditan Decoction(涤痰汤)in improving nonalcoholic fatty liver disease(non-alcoholic fatty liver disease,NAFLD)is related to the regulation of cholesterol outflow mediated by PPARγ-LXR-ABCA1/ABCG1 pathway.Method Forty-five SPF rats were divided into control group,model group and Ditan Decoction group,and a rat model of NAFLD was prepared by feeding a high-fat diet for 12 weeks,and administered by gavage at week 9.The levels of triglyceride(TG),total cholesterol(TC),low density lipoprotein cholesterol(LDL-C),high density lipoprotein cholesterol(HDL-C),alanine aminotransferase(ALT)and aspartate transaminase(AST)were detected in each group,and the pathological morphological changes of liver were observed by HE and oil red O staining.RT-qPCR and Wes automatic western blot quantitative analysis system detected gene mRNA and protein expressions of PPARγ,LXR,ABCA1 and ABCG1.Results Compared with those of the control group,the serum levels of TG,TC,LDL-C,ALT and AST in the model group increased significantly(P<0.01)and HDL-C levels decreased significantly(P<0.05).Hepatocyte arrangement was disordered,and fat vacuoles and lipid deposition were obvious.The expression levels of PPARγ,LXR,ABCA1 and ABCG1 genes and proteins in liver were significantly reduced(P<0.05 or P<0.01).After the intervention of Ditan Decoction,the dyslipidemia was improved,and the levels of ALT and AST were significantly reduced(P<0.05 or P<0.01).The hepatocyte swelling decreased and the fat vacuoles and lipid deposition decreased.The expression levels of PPARγ,ABCG1 genes and proteins in liver were significantly increased(P<0.05 or P<0.01),and the expression level of ABCA1 protein was significantly increased(P<0.01).Conclusion Ditan Decoction may improve NAFLD by regulating cholesterol outflow mediated by PPARγ-LXR-ABCA1/ABCG1 pathway.