Li Han-Geng, Tian Wen-Hua, Qin Cun-Lan, Ye Rong-Rong, Liu Dong-Hua, Liu Hui-Wen
Department of Histology and Embryology, College of Basic Medicine, Harbin Medical University, Harbin 150081, China.
Emergency Department, The Fourth Hospital of Harbin Medical University, Harbin 150081, China.
Aging (Albany NY). 2021 Mar 19;13(7):9704-9718. doi: 10.18632/aging.202722.
The regulation of mTOR and the dimethylation of histone H3 on lysine 9 (H3K9me2) H3K9me2 by Uhrf1 and the mechanism of autophagy regulation in myocardial ischemia-reperfusion injury (MIRI) were studied and . An I/R injury model was established using the primary mouse cardiomyocytes treated with HO. Subsequent analysis by qRT-PCR, western blot, and immunofluorescence indicated that overexpression of Uhrf1 significantly inhibited apoptosis of the HO-treated cardiomyocytes, reduced expression of apoptosis factors caspase-3 and Bax, and increased expression of apoptosis inhibitory factor Bcl-2. Furthermore, Uhrf1 was found to increase cardiomyocyte proliferation and promote the expression of mTOR, while the four expression peaks of H3K9me2 on the mTOR gene were inhibited by overexpression of Uhrf1. The expression of autophagy factors LC3, Beclin-1, and p-mTOR in Uhrf1-overexpressed cardiomyocytes was dramatically increased, and P62 expression was dramatically decreased. When an H3K9me2 inhibitor was added to the Uhrf1-knockdown cardiomyocytes, the expression of mTOR was increased, the expression of LC3, Beclin-1, and p-mTOR was decreased, and P62 expression was significantly increased. In the present study, Uhrf1 exhibits a protective function in MIRI, reducing the apoptosis of cardiomyocytes while increasing their proliferation and viability.
研究了Uhrf1对mTOR的调控以及组蛋白H3赖氨酸9位点二甲基化（H3K9me2）在心肌缺血再灌注损伤（MIRI）中的自噬调控机制。采用HO处理的原代小鼠心肌细胞建立I/R损伤模型。随后通过qRT-PCR、蛋白质印迹法和免疫荧光分析表明，Uhrf1的过表达显著抑制了HO处理的心肌细胞的凋亡，降低了凋亡因子caspase-3和Bax的表达，并增加了凋亡抑制因子Bcl-2的表达。此外，发现Uhrf1可增加心肌细胞增殖并促进mTOR的表达，而Uhrf1的过表达抑制了mTOR基因上H3K9me2的四个表达峰。Uhrf1过表达的心肌细胞中自噬因子LC3、Beclin-1和p-mTOR的表达显著增加，而P62表达显著降低。当向Uhrf1敲低的心肌细胞中添加H3K9me2抑制剂时，mTOR的表达增加，LC3、Beclin-1和p-mTOR的表达降低，P62表达显著增加。在本研究中，Uhrf1在MIRI中发挥保护作用，减少心肌细胞凋亡，同时增加其增殖和活力。
