乳酸脱氢酶A通过AMPK信号通路抑制人脑胶质瘤细胞线粒体自噬

该研究旨在探讨乳酸脱氢酶A(lactate dehydrogenase A,LDHA)对人脑胶质瘤细胞线粒体自噬的影响。用质粒sh-EGFP或sh-LDHA转染人脑胶质瘤细胞株U87MG,qRT-PCR和Western blot检测干扰效率,荧光染色技术检测线粒体ROS水平及线粒体膜电位,Western blot检测线粒体自噬相关蛋白及AMPK信号通路相关蛋白表达。结果表明,与sh-EGFP组相比较,sh-LDHA组人脑胶质瘤细胞U87MG中LDHA的mRNA及蛋白质水平均显著降低,线粒体ROS的产生增加,线粒体膜电位明显降低,线粒体自噬相关蛋白PINK1、Parkin及BNIP3、BNIP3L的表达增高,AMPK的磷酸化水平明显升高,而mTOR的磷酸化水平降低。研究结果表明,LDHA能够通过抑制AMPK信号通路,降低线粒体ROS水平,提高线粒体膜电位,抑制线粒体自噬。

Lactate Dehydrogenase A Inhibits Mitophagy in Human Glioma Cells via AMPK Signaling Pathway

The aim of the study was to investigate the effect of LDHA on mitophagy in human glioma cells.The sh-LDHA or sh-EGFP plasmids were transfected into the glioma cells U87MG,respectively.qRT-PCR and Western blot were used to detect the efficiency of plasmid knockdown.The expression levels of mitophagy-related proteins and AMPK signaling pathway-related proteins were detected by Western blot.Then mitochondrial ROS and mitochondrial membrane potential levels were detected by fluorescence staining.Compared with sh-EGFP group,the mRNA and protein levels of LDHA were significantly decreased,and mitochondrial ROS level raised,mitochondrial membrane potential declined in the sh-LDHA group.Also,the expression of mitophagy-related proteins PINK1,Parkin,BNIP3,BNIP3L and AMPK signaling pathway-related proteins p-AMPK were significantly increased,while p-mTOR was decreased under these processing conditions in the sh-LDHA group.In summary,LDHA inhibits AMPK signaling pathway,reducing mitochondrial ROS levels,enhancing mitochondrial membrane potential,and inhibits mitophagy.