银杏叶提取物通过Wnt减轻内质网应激诱导的心肌细胞损伤

目的 探讨银杏叶提取物（EGB）对内质网应激诱导心肌细胞损伤的影响以及Wnt通路在其中的作用。方法 取1d龄乳鼠心肌细胞培养后，应用衣霉素（Tm）构建心肌细胞损伤模型，随机分为对照组、Tm组、Tm＋EGB组、EGB组。噻唑蓝（MTT）比色法检测心肌细胞存活率，双荧光报告系统检测Wnt活性，实时定量PCR检测C-myc、CyclinD1基因水平。结果 Tm降低了心肌细胞存活率，EGB处理改善了心肌细胞存活率；与对照组比较，Tm组Wnt活性显著降低，与Tm组比较，Tm＋EGB组Wnt活性、C-myc、CyclinD1水平明显升高，而应用Wnt抑制剂分泌型卷曲相关蛋白（sFRP），Wnt活性显著下调，C-myc、CyclinD1水平下调，EGB的保护作用显著下降。结论 EGB可以抑制Tm诱导的大鼠心肌细胞损伤，其机制可能与改善Wnt信号有关。

EGB attenuates endoplasmic reticulum stress-induced injury in cultured rat neonatal cardiomyocytes through Wnt signal pathway

Objective To determine the effect of the extracts of Ginkgo biloba leaf (EGB) on the endoplasmic reticulum stress-induced cardiomyocyte injury and investigate the role of Wnt signal pathway in this process. Methods Tunicamycin(Tm) was used to establish the endoplasmic reticulum stress model in rat cardiomyocytes which were isolated from neonatal rats in 1d after born and then cultured for 48h. There were 4 groups of cardiomyocytes, that is, control, Tm treated, Tm+EGB treated and EGB treated. MTT assay was used to detect cell viability. The dual-luciferase report system was used to measure Wnt activity. C-myc and CyclinD1 were detected by real-time PCR. Results Compared to control cells, Tm treatment resulted in significantly decreased cell viability, but the presence of EGB markedly attenuated the cell injury. The treatment also decreased the activity of Wnt, whereas co-treatment of Tm and EGB led to not only the increase in Wnt activity, but also recovery of the C-myc and CyclinD1 levels. However, Wnt inhibitor, secreted frizzled-related protein (sFRP) decreased Wnt activity, C-myc and CyclinD1 levels, and inversed EGB-induced protective effect. Conclusion These findings demonstrate that EGB protects cardiomyocytes against Tm-induced injury through improving Wnt activity.