Group of Molecular and Cellular Cardiology, Department of Circulation and Medical Imaging, Faculty of Medicine and Health, Norwegian University of Science and Technology (NTNU), 7034 Trondheim, Norway.
Department of Cardiothoracic Surgery, St. Olavs University Hospital, 7030 Trondheim, Norway.
Int J Mol Sci. 2022 Aug 19;23(16):9375. doi: 10.3390/ijms23169375.
Apoptotic cell death is a deleterious consequence of hypoxia-induced cellular stress. The master , microRNA-210 (miR-210), is considered the primary driver of the cellular response to hypoxia stress. We have recently demonstrated that miR-210 attenuates hypoxia-induced apoptotic cell death. In this paper, we unveil that the miR-210-induced inhibition of the serine/threonine kinase Glycogen Synthase Kinase 3 beta (GSK3β) in AC-16 cardiomyocytes subjected to hypoxia stress underlies the salutary protective response of miR-210 in mitigating the hypoxia-induced apoptotic cell death. Using transient overexpression vectors to augment miR-210 expression concomitant with the ectopic expression of the GSK3β S9A mutant (-GSK3β S9A), we exhaustively performed biochemical and molecular assays to determine the status of the hypoxia-induced intrinsic apoptosis cascade. Caspase-3 activity analysis coupled with DNA fragmentation assays cogently demonstrate that the inhibition of GSK3β kinase activity underlies the miR-210-induced attenuation in the hypoxia-driven apoptotic cell death. Further elucidation and delineation of the upstream cellular events unveiled an indispensable role of the inhibition of GSK3β kinase activity in mediating the miR-210-induced mitigation of the hypoxia-driven BAX and BAK insertion into the () and the ensuing release into the cytosol. Our study is the first to unveil that the inhibition of GSK3β kinase activity is indispensable in mediating the miR-210-orchestrated protective cellular response to hypoxia-induced apoptotic cell death.
细胞凋亡是缺氧诱导细胞应激的有害后果。主调控 microRNA-210（miR-210）被认为是细胞对缺氧应激反应的主要驱动因素。我们最近证明，miR-210 可减轻缺氧诱导的细胞凋亡。在本文中，我们揭示了 miR-210 在缺氧应激下抑制丝氨酸/苏氨酸激酶糖原合成酶激酶 3β（GSK3β）的作用，这是 miR-210 抑制缺氧诱导的细胞凋亡的有益保护反应的基础。我们使用瞬时过表达载体来增加 miR-210 的表达，同时过表达 GSK3β S9A 突变体（-GSK3β S9A），我们进行了详尽的生化和分子实验，以确定缺氧诱导的内在凋亡级联的状态。Caspase-3 活性分析结合 DNA 片段化分析有力地证明了 GSK3β 激酶活性的抑制是 miR-210 减轻缺氧诱导的细胞凋亡的基础。进一步阐明和描述细胞上游事件揭示了抑制 GSK3β 激酶活性在介导 miR-210 诱导的减轻缺氧驱动的 BAX 和 BAK 插入 () 以及随后的 () 释放到细胞质中的不可或缺的作用。我们的研究首次揭示了抑制 GSK3β 激酶活性在介导 miR-210 协调的对缺氧诱导的细胞凋亡的保护细胞反应中是不可或缺的。
