基于PERK-eIF2α通路探讨冠心康对LDLR-/-高脂血症小鼠血脂的调控机制

Study on the Mechanism of Guanxinkang on Blood Lipids in LDLR-/-Hyperlipidemia Mice Based on PERK-eIF2αPathway

目的观察中药复方冠心康对LDLR-/-高脂血症小鼠肝脏PERK-eIF2α信号通路以及ATP结合盒转运子亚家族成员1(ABCA1)和固醇调节元件结合蛋白-2(SREBP-2)的影响,探讨冠心康对高脂血症的调控机制。方法通过高脂饮食诱导30只LDLR-/-小鼠12周,构建高脂血症模型小鼠后随机分为模型组、冠心康组和辛伐他汀组,以10只同遗传背景的C57BL/6J小鼠为正常组。冠心康组以冠心康煎剂灌胃,辛伐他汀组以辛伐他汀水溶液进行灌胃。各组干预12周取材进行指标检测。生化仪检测血清血脂;HE染色观察肝脏病理形态变化;real-time PCR检测肝脏PERK、eIF2α、SREBP-2、ABCA1基因表达;Western blot法检测肝脏PERK、eIF2α磷酸化水平和SREBP-2、ABCA1蛋白表达。结果与模型组比较,冠心康组和辛伐他汀组的血清TG、TC下降(P<0.05),HDL-C升高(P<0.05),冠心康组和辛伐他汀组对蛋白PERK磷酸化以及SREBP-2水平有下调作用,对ABCA1有上调作用,差异具有统计学意义(P<0.05)。结论冠心康通过影响SREBP-2和ABCA1的表达,可显著调节LDLR-/-高脂血症小鼠的血脂水平,从而维持肝脏胆固醇稳态的平衡,其作用机制可能与PERK-eIF2α信号通路有关。

Objective Through observing the effects of Chinese medicine compound Guanxinkang on the liver PERKeIF2αsignaling pathway,ATP-binding cassette transporter subfamily member 1(ABCA1)and sterol regulatory element binding protein-2(SREBP-2)in LDLR-/-hyperlipidemic mice,to explore the regulation mechanisms of Guanxinkang on hyperlipidemia.Methods A total of 30 LDLR-/-mice were induced by high-fat diet for 12 weeks.The hyperlipidemia model mice were randomly divided into a model group,a Guanxinkang group and a simvastatin group.And 10 C57 BL/6 J mice with genetic background were set as a normal group.The Guanxinkang group was treated with Guanxinkang Decoction,and the western medicine group was fed with simvastatin aqueous solution.Each group was sacrificed after having been intervened for 12 weeks.Serum blood lipids were detected by biochemical analyzer;liver pathological changes were observed by HE staining;the expression levels of protein and gene of PERK,eIF2α,SREBP-2 and ABCA1 were determined by real-time fluorescence quantitative PCR and Western-blot.Results Compared with the model group,serum TG and TC distinctly decreased in the Guanxinkang group and the simvastatin group(P<0.05),and meanwhile HDL-C increased(P<0.05).Furthermore,the expression of PERK phosphorylation and SREBP-2 levels were down-regulated,while the expression of ABCA1 was up-regulated,and the difference was statistically significant(P<0.05).Conclusion By affecting the expression of SREBP-2 and ABCA1,Guanxinkang can significantly adjust the blood lipid level of LDLR-/-hyperlipidemia mice,thus maintaining the balance of liver cholesterol homeostasis.The mechanisms may be related to the PERK-eIF2αsignaling pathway.