Department of Central Laboratory, Affiliated Yancheng Hospital, School of Medicine, Southeast University, West Xindu Road 2#, Yancheng, 224001, Jiangsu, People's Republic of China.
Department of Neurology, Drum Tower Hospital, Medical School of Nanjing University, Zhongshan Road 321#, Nanjing, 210008, Jiangsu, People's Republic of China.
Hum Cell. 2020 Oct;33(4):1026-1035. doi: 10.1007/s13577-020-00396-w. Epub 2020 Jul 18.
Ischemic stroke is characterized by loss of brain function because of cerebral ischemia. Evidence has been shown that miR-217-5p is significantly downregulated in infarcted brain areas following focal cerebral ischemia. However, the role of miR-217-5p in ischemic stroke is still unclear. To mimic ischemia/reperfusion (I/R) injury conditions in vitro, SH-SY5Y cells were treated with oxygen-glucose deprivation/reperfusion (OGD/R). Our data found that PTEN was the directly target of miR-217-5p in SH-SY5Y cells. The level of miR-217-5p was significantly decreased, while the level of PTEN was notably increased in SH-SY5Y cells following OGD/R treatment. Overexpression of miR-217-5p markedly promoted the proliferation and cell cycle progression, and inhibited apoptosis in OGD/R-treated SH-SY5Y cells. In addition, overexpression of miR-217-5p significantly decreased the expressions of PTEN and FOXO1, but increased the expression of p-Akt in OGD/R-treated SH-SY5Y cells. Moreover, methylation specific PCR (MSP) results indicated the CpG islands in the promoter region of miR-217-5p were hypermethylated in SH-SY5Y cells under OGD/R. Meanwhile, the DNA methylation of miR-217-5p promoter region decreased expression of miR-217-5p. Our data indicated that miR-217-5p could attenuate ischemic injury by inhibiting PTEN. In addition, DNA methylation-mediated silencing of miR-217-5p may serve as a promising therapeutic target of ischemic stroke.
缺血性脑卒中的特征是由于脑缺血导致的脑功能丧失。有证据表明，在局灶性脑缺血后，miR-217-5p 在梗死脑区显著下调。然而，miR-217-5p 在缺血性脑卒中中的作用仍不清楚。为了在体外模拟缺血/再灌注（I/R）损伤条件，用氧葡萄糖剥夺/再灌注（OGD/R）处理 SH-SY5Y 细胞。我们的数据发现，PTEN 是 SH-SY5Y 细胞中 miR-217-5p 的直接靶标。在 OGD/R 处理后，SH-SY5Y 细胞中 miR-217-5p 的水平显著降低，而 PTEN 的水平显著增加。miR-217-5p 的过表达显著促进了 OGD/R 处理的 SH-SY5Y 细胞的增殖和细胞周期进程，并抑制了细胞凋亡。此外，miR-217-5p 的过表达显著降低了 OGD/R 处理的 SH-SY5Y 细胞中 PTEN 和 FOXO1 的表达，而增加了 p-Akt 的表达。此外，甲基化特异性 PCR（MSP）结果表明，在 OGD/R 下，miR-217-5p 启动子区的 CpG 岛发生了高甲基化。同时，miR-217-5p 启动子区的 DNA 甲基化降低了 miR-217-5p 的表达。我们的数据表明，miR-217-5p 通过抑制 PTEN 来减轻缺血性损伤。此外，miR-217-5p 的 DNA 甲基化介导沉默可能成为缺血性脑卒中有前途的治疗靶点。
