GSK3β/Fis1信号通路在甲基乙二醛诱导成骨细胞凋亡中的作用及机制

Role and Mechanism of GSK3β/Fis1 Signaling Pathway in the Apoptosis of Osteoblast Induced by Methylglyoxal

目的探讨糖原合成酶激酶3β(glycogen synthase kinase 3β,GSK3β)/线粒体分裂蛋白1(fission protein 1,Fis1)信号通路在甲基乙二醛(methylglyoxal,MG)诱导成骨细胞凋亡中的作用及机制。方法采用LiCl作为GSK3β抑制剂,将细胞随机分为4组,即对照组、MG组、LiCl组和LiCl+MG组。采用MTT法检测细胞增殖活性,Tunel染色法分析细胞凋亡情况,Western blot法检测GSK3β、Fis1蛋白表达水平,MitoTracker Deep Red染色法分析线粒体形态。结果MTT法检测结果表明,MG抑制了成骨细胞增殖活性。Tunel染色法检测结果显示,MG诱导成骨细胞凋亡。Western blot法检测结果表明,MG处理后GSK3β蛋白磷酸化水平降低,Fis1蛋白表达水平增加。MitoTracker Deep Red染色法分析结果显示,MG处理后线粒体呈碎片化。在加入GSK3β抑制剂LiCl干预后,与MG组比较,其显著恢复了MG抑制的细胞增殖活性、减少细胞凋亡,同时GSK3β蛋白磷酸化水平升高,Fis1蛋白表达水平降低,并且恢复了线粒体形态。结论MG可能通过调控GSK3β/Fis1信号通路促进线粒体分裂增加,诱导成骨细胞凋亡。

Objective To explore the role and mechanism of glycogen synthase kinase 3β(GSK3β)/fission protein 1(Fis1)signaling pathway in the apoptosis of osteoblast induced by methylglyoxal.Methods LiCl was used as GSK3βinhibitor,and the cells were randomly divided into 4groups:control group,MG group,LiCl group,LiCl+MG group.The cell proliferation activity was detected by MTT assays.The cell apoptosis was analyzed by Tunel assays.The protein expression levels of GSK3βand Fis1 were detected by Western blot.Mitochondrial morphology was analyzed by MitoTracker Deep Red.Results MTT assay showed that MG inhibited the proliferation activity of osteoblast.Tunel staining showed that MG induced osteoblast apoptosis.Western blot assay showed that the phosphorylation level of GSK3βdecreased and the expression level of Fis1 protein increased after MG treatment.MitoTracker Deep Red staining showed that mitochondrion were fragmented after MG treatment.After the addition of GSK3βinhibitor LiCl,compared with the MG group,the MG-inhibited cell proliferation activity and apoptosis were significantly restored.Meanwhile,the phosphorylation level of GSK3βprotein was increased,the expression level of Fis1 protein was decreased,and the mitochondrial morphology was restored.Conclusion MG may promote the increase of mitochondrial division and induce osteoblast apoptosis by regulating GSK3β/Fis1signaling pathway.