牡荆素调节自噬对小鼠肝缺血/再灌注损伤的保护作用

摘要

目的：探讨牡荆素（Vitexin）对小鼠肝缺血/再灌注损伤（HIRI）的作用并阐述可能的机制。方法选取18只体重为20～25 g的健康雄性C57BL/6小鼠，随机分为假手术组（Sham组）、缺血/再灌注组（I/R组）和牡荆素组（Vitexin组），每组6只小鼠。Vitexin组于术前6 h腹腔注射10 mg/kg牡荆素。Sham组与I/R组腹腔注射等量生理盐水。I/R组和Vitexin组建立小鼠肝脏HIRI模型，Sham组仅进行开腹和关腹操作。检测各组小鼠血清中丙氨酸转氨酶（ALT）和天冬氨酸转氨酶（AST）水平，光镜下观察肝组织病理学改变， TUNEL法检测肝细胞凋亡情况；通过蛋白质免疫印迹试验（Western Blot）检测自噬调控因子Beclin1、抗凋亡相关基因Bcl-2、微管相关蛋白轻链3（LC3）与天冬氨酸特异性半胱氨酸蛋白酶3（caspase-3）的表达水平。结果与I/R组相比较，Vitexin组小鼠血清ALT和AST水平明显降低〔ALT（U/L）：201.57±77.12比444.31±92.61，AST（U/L）：311.72±90.91比623.54±112.05，均P＜0.05〕，且在光镜下可见肝细胞损伤减轻；同时凋亡的肝细胞数量明显减少；肝组织中Beclin1、LC3和caspase-3蛋白的表达水平明显降低，而Bcl-2蛋白的表达水平明显增加。结论牡荆素能够减轻小鼠HIRI，其机制可能与牡荆素抑制再灌注时肝细胞自噬有关。%Objective To explore the effect of vitexin on hepatic ischemia-reperfusion injury(HIRI) by regulating autophagy in mice.Methods Eighteen male C57BL/6 mice weigh20-25g were selected and divided into Sham group, Ischemia-Reperfusion(I/R) group and Vitexin group, respectively, with6 mice in each group. Vitexin group received intraperitoneal injection of vitexin10 mg/kg6 h preoperatively. Sham group and I/R group received equal amount of normal saline. HIRI model was constructed in I/R group and Vitexin group. Sham group received abdomen open and closure only. Serum alanine transaminase(ALT) and aspartate aminotransferase (AST) levels were detected in all groups, histopathological features were observed by hematoxylin-eosin(HE) staining, apoptosis was detected by Terminal-deoxynucleoitidyl Transferase Mediate Nick End Labeling (TUNEL)assay and expression of Beclin1, Bcl-2, LC3, caspase-3 proteins were detected by Western Blot.Results Compared with I/R group, Vitexin group had a significantly lower levels of ALT and AST in serum〔ALT(U/L):201.57±77.12 vs.444.31±92.61,AST(U/L):311.72±90.91 vs.623.54±112.05, all P<0.05〕, decreased injury of liver cells were shown in microscope and apoptotic cells marked by TUNEL assay, and the expressions of Beclin1, LC3, caspase-3 proteins were decreased while the expression of Bcl-2 protein increased at the same time.Conclusion Vitexin can attenuate HIRI in mice, which may be related to the inhibition of hepatocyte autophagy.