Liu Bi-Ying, Dai Zhao-Hui, Mao Li, Guo Ling-Zhi, Yang Zhong-Bao
Department of Basic Medicine, Changsha Health Vocational College, Changsha, 410600, Hunan, China.
Chest Pain Center of Changsha, The Affiliated Changsha Hospital of Hunan Normal University, Changsha, 410006, Hunan, China.
Sci Rep. 2025 Jul 1;15(1):22379. doi: 10.1038/s41598-025-07977-5.
The pathogenesis of myocardial ischemia-reperfusion injury (MIRI) is not fully clear. This study aims to investigate the role of mitochondrial-associated endoplasmic reticulum membrane (MAM)-related calcium overload in mitophagy. In vitro and in vivo models were established to simulate MIRI. Cellular injury, apoptosis and mitophagy were measured and gene expression was analysized. The expression levels of glucose-regulated protein 75 (GRP75), receptor for inositol 1,4,5-trisphosphate (IP3R3), voltage-dependent anion-selective channel 1 (VDAC1), and calmodulin (CaM) and the mitochondrial calcium content, mitophagy and apoptosis were significantly increased in MIRI or hypoxia/reoxygenation (H/R) cells when compared to controls, but the mitochondrial membrane potential and ATP significantly decreased. GRP75 knockdown significantly inhibited CaM expression, mitochondrial calcium overload and mitophagy of H9C2 cells, whereas had no significant effect on IP3R3 and VDAC1 expression. CaM knockdown had no significant effect on the expression of GRP75, IP3R3 and VDAC1, and on mitochondrial calcium concentration, ATP levels and mitochondrial membrane potential of H9C2 cells, but significantly inhibited mitophagy and apoptosis. Collectively, these data suggest that the IP3R3-GRP75-VDAC1/CaM axis plays an important role in mitochondrial autophagy injury during myocardial ischemia-reperfusion and that it is a potential target for MIRI treatment.
心肌缺血再灌注损伤（MIRI）的发病机制尚未完全明确。本研究旨在探讨线粒体相关内质网膜（MAM）相关的钙超载在细胞自噬中的作用。建立了体外和体内模型来模拟MIRI。检测细胞损伤、凋亡和细胞自噬，并分析基因表达。与对照组相比，MIRI或缺氧/复氧（H/R）细胞中葡萄糖调节蛋白75（GRP75）、肌醇1,4,5-三磷酸受体（IP3R3）、电压依赖性阴离子选择性通道1（VDAC1）和钙调蛋白（CaM）的表达水平以及线粒体钙含量、细胞自噬和凋亡均显著增加，但线粒体膜电位和ATP显著降低。GRP75基因敲低显著抑制H9C2细胞的CaM表达、线粒体钙超载和细胞自噬，而对IP3R3和VDAC1表达无显著影响。CaM基因敲低对H9C2细胞的GRP75、IP3R3和VDAC1表达以及线粒体钙浓度、ATP水平和线粒体膜电位无显著影响，但显著抑制细胞自噬和凋亡。总体而言，这些数据表明IP3R3-GRP75-VDAC1/CaM轴在心肌缺血再灌注期间的线粒体自噬损伤中起重要作用，并且它是MIRI治疗的潜在靶点。
