皂术茵陈方对非酒精性脂肪性肝炎大鼠IRE1α-XBP1-STAT1信号通路的影响

Effects of Zaozhu Yinchen Recipe on IRE1α-XBP1-STAT1 Signaling Pathway in Nonalcoholic Steatohepatitis Rats

目的观察皂术茵陈方对非酒精性脂肪性肝炎(NASH)大鼠的作用特点及其对肝脏内质网应激肌醇需求酶1α(IRE1α)-X-盒结合蛋白1(XBP1)-信号转导与转录激活因子1(STAT1)信号通路的影响,探讨其治疗NASH的作用机制。方法大鼠适应性喂养1周后,按随机数表法随机分成4组,即模型组、正常组、皂术茵陈方组、吡格列酮组,每组8只。采用高脂饮食16周建立大鼠NASH模型,在造模第9周开始给药,皂术茵陈方组每天给予皂术茵陈方10 g/kg灌胃;吡格列酮组每天给予盐酸吡格列酮10 mg/kg灌胃;正常组和模型组给予10 mL/kg双蒸水灌胃;共8周。观察大鼠一般状态;生化法检测血清谷丙转氨酶(ALT)、谷草转氨酶(AST)活性和肝组织甘油三酯(TG)、丙二醛(MDA)、还原型谷胱甘肽(GSH)含量;苏木精-伊红(HE)染色观察肝组织病理学变化;实时荧光定量聚合酶链式反应法(RT-PCR)和酶联免疫吸附测定法(ELISA)分别检测肝组织IRE1α、XBP1、STAT1等的基因与蛋白表达。结果与正常组比较,模型组大鼠显示出典型的NASH组织学特征,经过皂术茵陈方治疗后,肝细胞脂肪变性、炎症浸润较模型组减轻。模型组大鼠肝湿重、血清ALT、AST活性、肝脏TG、MDA、GSH含量均显著升高(P<0.01),同时,肝组织IRE1α、XBP1、STAT1的蛋白及基因表达亦显著升高(P<0.01)。经过皂术茵陈方治疗后,上述指标均显著降低(P<0.05)。结论皂术茵陈方具有改善NASH大鼠肝细胞脂肪变性、气球样变性、炎症以及内质网应激损伤的药理效应,同时可显著降低肝组织IRE1α、XBP1、STAT1表达,提示皂术茵陈方治疗NASH的作用机制与调控内质网应激IRE1α-XBP1-STAT1信号通路有关。

Objective To observe the effect characters of Zaozhu Yinchen Recipe(ZYR)on nonalcoholic steatohepatitis(NASH)rats and its effect on IRE1α-XBP1-STAT1 signaling pathway of hepatic endoplasmic reticulum stress(ERS),and to study its mechanism on NASH.Methods After one week of adaptive feeding,the rats were divided into 4 groups according to random number table,i.e.,model group,normal group,ZYR group,and pioglitazone group,8 rats in each group.The Nash rat model was established by high-fat diet for 16 weeks.The drug was administered from the 9th week of modeling.Rats in ZYR group were administered with ZYR 10 g/kg by gastrogavage every day.Those in pioglitazone group were administered with pioglitazone hydrochloride 10 mg/kg by gastrogavage every day.Those in the normal group and model group were administered with 10 mL/kg double distilled water by gastrogavage every day.All treatment lasted for 8 successive weeks.The general states of rats were observed.The activities of serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST),and the contents of total triglyceride(TG),malondialdehyde(MDA),and glutathione(GSH)in liver tissue were detected by biochemical method.Hematoxylin eosin(HE)staining was used to observe the pathological changes of liver tissue.Real-time PCR and ELISA were used to detect gene and protein expressions of IRE1α,XBP1,STAT1 in liver tissue.Results Compared with the normal group,the rats in the model group showed typical histological characteristics of NASH.Compared with the model group,the steatosis and inflammatory infiltration of hepatocytes were attenuated in the ZYR group.The liver wet weight,The activities of serum ALT and AST,the contents of liver TG,MDA,and GSH in the model group significantly increased(P<0.01).Meanwhile,the protein and gene expressions of IRE1α,XBP1,and STAT1 also significantly increased(P<0.01).After treatment with ZYR,the above indices significantly decreased(P<0.05).Conclusion ZYR had pharmacological effects on improving steatosis,ballooning degeneration,inflammation and ERS injury in NASH rats,and significantly lowered the expressions of IRE1α,XBP1,and STAT1,which suggested the mechanism of ZYR for treating NASH was associated with regulating IRE1α-XBP1-STAT1signaling pathway of ERS.