Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Shock. 2024 May 1;61(5):791-800. doi: 10.1097/SHK.0000000000002333. Epub 2024 Feb 7.
Intestinal ischemia-reperfusion injury (IIRI) is a serious disease with high morbidity and mortality. This study aims to investigate the potential regulatory mechanisms involving protein arginine methyltransferase 6 (PRMT6), Forkhead box O3a (FoxO3a), and Parkin in IIRI and elucidate their roles in mediating cell apoptosis. The IIRI animal model was established and confirmed using hematoxylin and eosin staining. Oxygen-glucose deprivation and reperfusion (OGD/R) cell model was established to mimic ischemic injury in vitro . Transient transfection was used to overexpress or knock down genes. Cell death or apoptosis was assessed by propidium iodide staining, terminal deoxynucleotidyl transferase dUTP nick end labeling assay, and flow cytometry. The expression of proteins was detected by western blot. The histopathology observed by hematoxylin and eosin staining suggested that the IIRI animal model was successfully established. Our findings revealed that IIRI resulted in increased Bax and decreased Bcl-2 levels. In vitro experiments showed that overexpression of Parkin decreased OGD/R injury and suppressed elevation of Bax/Bcl-2. PRMT6 regulated the methylation level of FoxO3a. Moreover, FoxO3a directly binds to Parkin, and FoxO3a overexpression reduced OGD/R-induced cell death and regulation of Parkin. Overexpression of PRMT6 can attenuate the downregulation of Parkin and elevation of Bax/Bcl-2 caused by OGD/R. Knockdown of PRMT6 promoted apoptosis in intestinal epithelial cells of OGD/R group, while PRMT6 overexpression exhibited the opposite effect. Notably, the levels of PRMT6, FoxO3a, and Parkin were decreased in IIRI mouse intestinal tissue. Knocking out PRMT6 causes a significant decrease in the lifespan of mice. Altogether, our results demonstrated that PRMT6 upregulated the expression of Parkin by regulating FoxO3a methylation level, attenuating the apoptosis induced by IIRI.
肠缺血再灌注损伤（IIRI）是一种发病率和死亡率都很高的严重疾病。本研究旨在探讨涉及蛋白质精氨酸甲基转移酶 6（PRMT6）、叉头框蛋白 O3a（FoxO3a）和 Parkin 的潜在调节机制，阐明它们在介导细胞凋亡中的作用。通过苏木精和伊红染色来确认 IIRI 动物模型的建立和确认。建立氧葡萄糖剥夺和再灌注（OGD/R）细胞模型来模拟体外缺血损伤。瞬时转染用于过表达或敲低基因。通过碘化丙啶染色、末端脱氧核苷酸转移酶 dUTP 缺口末端标记法和流式细胞术评估细胞死亡或凋亡。通过 Western blot 检测蛋白质的表达。苏木精和伊红染色观察到的组织病理学表明，IRI 动物模型成功建立。我们的研究结果表明，IRI 导致 Bax 增加和 Bcl-2 减少。体外实验表明，Parkin 的过表达降低了 OGD/R 损伤并抑制了 Bax/Bcl-2 的升高。PRMT6 调节 FoxO3a 的甲基化水平。此外，FoxO3a 直接与 Parkin 结合，FoxO3a 的过表达减少了 OGD/R 诱导的细胞死亡和 Parkin 的调节。PRMT6 的过表达可以减轻 OGD/R 引起的 Parkin 下调和 Bax/Bcl-2 升高。PRMT6 的敲低促进了 OGD/R 组肠上皮细胞的凋亡，而 PRMT6 的过表达则表现出相反的效果。值得注意的是，PRMT6、FoxO3a 和 Parkin 的水平在 IIRI 小鼠肠组织中降低。敲除 PRMT6 导致小鼠的寿命显著缩短。总之，我们的研究结果表明，PRMT6 通过调节 FoxO3a 甲基化水平上调 Parkin 的表达，减轻 IIRI 引起的细胞凋亡。
