基于肌醇需求激酶1α/c-Jun氨基末端激酶信号通路探讨胆宁片干预非酒精性脂肪性肝病的作用及机制

Effect and Mechanism of Danning Tablets in the Intervention of Non-Alcoholic Fatty Liver Disease Based on IRE1α/JNK Signaling Pathway

目的基于肌醇需求激酶1α/c-Jun氨基末端激酶(IRE1α/JNK)信号通路,探讨胆宁片对非酒精性脂肪性肝病(NAFLD)模型大鼠的作用及机制。方法将32只SD大鼠随机分为正常饮食组(A组,等体积生理盐水,8只)和高脂饮食组(24只);高脂饮食组大鼠喂养10周复制NAFLD模型成功后,再随机分为模型组(B组,等体积生理盐水)、多烯磷脂酰胆碱组[C组,142.5 mg/(kg·d)]和胆宁片组[D组,562.5 mg/(kg·d)],各8只。各组小鼠均灌胃相应药物干预6周。测定大鼠的体质量、血糖(GLU);采用苏木精-伊红染色(HE)法观察大鼠肝组织病理形态变化,采用油红染色法观察肝组织脂质沉积;检测血清胰岛素(INS)、总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)、游离脂肪酸(NEFA)、丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)水平;采用免疫印迹(Western blot)法检测肝组织IRE1α、JNK1、磷酸化胰岛素受体底物1(p-IRS1)的蛋白表达水平。结果与B组比较,D组大鼠血糖和TC,TG,LDL-C,NEFA,ALT,AST水平均显著降低(P<0.01),血清INS和HDL-C水平显著升高(P<0.01);脂肪变性程度及细胞肿胀明显减轻,脂滴空泡体积缩小,数量减少;肝脏IRE1α,JNK1,p-IRS1蛋白表达水平均显著降低(P<0.01)。结论胆宁片可能通过下调IRE1α/JNK信号通路,减轻肝脏脂肪变性,从而改善NAFLD。

Objective To investigate the effect and mechanism of Danning Tablets on non-alcoholic fatty liver disease(NAFLD)model rats based on inositol requiring enzyme 1α/c-Jun N-terminal kinase(IRE1α/JNK)signaling pathway.Methods A total of 32 SD rats were randomly divided into the normal diet group(group A,equal volume of normal saline,n=8)and the high-fat diet group(n=24).The rats in the high-fat diet group were fed for 10 weeks to replicate the NAFLD model,and they were randomly divided into the model group(group B,equal volume of normal saline),polyene phosphatidylcholine group[group C,142.5 mg/(kg·d)]group and Danning Tablets group[group D,562.5 mg/(kg·d)],eight mice in each group.Mice in each group were orally administered with corresponding drugs for six weeks.The body weight and blood glucose of rats were determined.The pathological morphological changes and lipid deposition in liver tissue were observed by hematoxylin-eosin(HE)staining and oil red staining respectively.The levels of serum insulin(INS),total cholesterol(TC),triglycerides(TG),low-density lipoprotein cholesterol(LDL-C),high-density lipoprotein cholesterol(HDL-C),free fatty acids(NEFA),alanine aminotransferase(ALT),and aspartate aminotransferase(AST)were detected.The expression levels of IRE1α,JNK1 and phosphorylated insulin receptor substrate 1(p-IRS1)protein were detected by Western blot.Results Compared with those in group B,the levels of blood glucose,TC,TG,LDL-C,NEFA,ALT,and AST in group D were significantly lower(P<0.01),while the levels of serum INS and HDL-C in group D were significantly higher(P<0.01);the degree of fat degeneration and cell swelling of rats in group D significantly reduced,and the volume and number of lipid droplet vacuoles in group D decreased;the expression levels of IRE1α,JNK1 and p-IRS1 protein significantly decreased(P<0.01).Conclusion Danning Tablets may alleviate hepatic steatosis and improve NAFLD by down-regulating the RElα/JNK signaling pathway.