Wnt/β-catenin信号在高糖诱导H9c2心肌细胞损伤与凋亡中的作用

Role of Wnt/β-catenin pathway on high glucose-induced H9c2 myocardial cell injury and apoptosis

目的:探讨Wnt/β-catenin信号通路是否参与体外培养条件下高糖诱导的H9c2心肌细胞损伤凋亡,及其与细胞自噬的关系。方法:构建高糖诱导H9c2心肌细胞凋亡细胞模型,CCK-8法和流式细胞仪检测细胞存活率和凋亡率,Western blot检测H9c2心肌细胞caspase-3、LC3-Ⅱ/LC3-Ⅰ、Axin-1和β-catenin的表达。结果:与对照组相比,50 mmol/L高糖处理H9c2心肌细胞48 h后,细胞存活率急速下降,caspase-3表达增强;其次,Western blot实验结果显示高糖促进wnt/β-catenin的激活,表现为Axin-1表达抑制,β-catenin表达显著升高,并伴随细胞内LC3-Ⅱ/LC3-Ⅰ比值降低;DKK预处理能削弱高糖引起的H9c2心肌细胞凋亡,下调Axin-1活性,增强β-catenin表达和LC3-Ⅱ/LC3-Ⅰ比值。结论:Wnt/β-catenin通路在高糖致H9c2心肌细胞损伤与凋亡过程中被激活,且其的激活抑制了自噬通路的活化。而当添加D-葡萄糖(Dickkopf-1,DKK-1)抑制Wnt/β-catenin后,自噬作用增强,高糖诱导的H9c2心肌细胞凋亡率明显下降。

Objective： To investigate role of Wnt/β-catenin pathway on high glucose-induced H9c2 myocardial cell apoptosis, and evaluate the relationship between Wnt/β-catenin and autophagy.Methods： H9c2 myocardial cell apoptosis model induced by high glucose was constructed, cell viability and apoptosis ratio was determined by CCK-8 and flow cytometry, Western blot analysis was used to detect the expression of caspase-3, LC3-Ⅱ/LC3-Ⅰ, Axin-1 and β-catenin in H9c2 myocardial cell.Results： Cell viability fell sharply, and protein expression of caspase-3 were remarkably increased in H9c2 myocardial cell treatment with 50 mmol/L high glucose for 48 h compared with control cells. Furthermore, Western blot analysis revealed that high glucose triggered Wnt pathways, thus suppressed the expression level of Axin-1 and promoted β-catenin expression and LC3-Ⅱ/LC3-Ⅰ ratio. Pretreatment by 〈br〉 dickkopf-1（DKK-1） attenuated HG-induced apoptosis of H9c2 myocardial cell, down-regulated the activity of Axin-1, and significantly increased the expression of β-catenin and LC3-Ⅱ/LC3-Ⅰ ratio, and reduced the production of β-catenin.Conclusion：This study has demonstrated that Wnt/β-catenin pathway was activated on HG-induced injury and apoptosis in H9c2 cells and that was associated with inhibition of autophagy pathways. Furthermore, blocking the Wnt/β-catenin signaling with the selective antagonist DKK-1 resulted in enhancement of autophagy, and inhibition of the apoptotic index in high glucose-induced H9c2 myocardial cell.