Ren Xiaoli, Wang Zhiyun, Guo Congfang
Department of Neurology, Tianjin First Central Hospital, Tianjin, 300192, People's Republic of China.
Department of Emergency, Tianjin First Central Hospital, Tianjin, 300192, People's Republic of China.
Neuropsychiatr Dis Treat. 2021 Apr 29;17:1231-1242. doi: 10.2147/NDT.S297975. eCollection 2021.
MiR-195-5p has been shown to play crucial roles in tumor inhibition, but its biological functions in cerebral ischemia-reperfusion (I/R) injury are unclear.
To mimic cerebral I/R injury, mice were induced by transient middle cerebral artery occlusion (MCAO). Human brain microvascular endothelial cells (HBMVECs) were treated with oxygen-glucose deprivation (OGD) to mimic I/R injury in vitro. The expression of miR-195-5p and PTEN was detected by qRT-PCR or Western blot. Cell viability was evaluated by CCK-8 assay. Cell apoptosis was detected by flow cytometer. Cell death was detected using specific lactate dehydrogenase (LDH) cytotoxicity kit. Infarct volume in mice brains was evaluated by TTC staining. Histopathological analysis was performed by HE staining and TUNEL staining. The interaction between miR-195-5p and PTEN was determined by TargetScan and luciferase reporter assay.
MiR-195-5p was significantly downregulated and PTEN was upregulated during cerebral I/R injury both in vitro and in vivo. Overexpression of miR-195-5p efficiently enhanced cell viability, while reduced LDH release and apoptotic rate of OGD-treated HBMVECs in vitro. MiR-195-5p could negatively regulate the expression of PTEN by directly binding to its 3'-UTR. Overexpression of PTEN obviously attenuated the protective effect of miR-195-5p mimics on cell viability, LDH release and apoptosis in OGD-treated HBMVECs. Meanwhile, overexpression of miR-195-5p increased the expression levels of p-AKT in OGD-treated HBMVECs, while this effect was reversed by overexpression of PTEN. Moreover, overexpression of miR-195-5p efficiently ameliorated brain injury of mice after MCAO treatment in vivo.
Overexpression of miR-195-5p ameliorated cerebral I/R injury by regulating the PTEN-AKT signaling pathway, providing a potential therapeutic target for cerebral I/R injury.
已有研究表明，miR-195-5p在肿瘤抑制中发挥关键作用，但其在脑缺血再灌注（I/R）损伤中的生物学功能尚不清楚。
为模拟脑I/R损伤，采用短暂大脑中动脉闭塞（MCAO）诱导小鼠发病。在体外，用人脑微血管内皮细胞（HBMVECs）进行氧糖剥夺（OGD）处理以模拟I/R损伤。通过qRT-PCR或蛋白质免疫印迹法检测miR-195-5p和PTEN的表达。采用CCK-8法评估细胞活力。用流式细胞仪检测细胞凋亡。使用特异性乳酸脱氢酶（LDH）细胞毒性试剂盒检测细胞死亡情况。通过TTC染色评估小鼠脑梗死体积。采用苏木精-伊红（HE）染色和TUNEL染色进行组织病理学分析。通过TargetScan和荧光素酶报告基因检测确定miR-195-5p与PTEN之间的相互作用。
在体外和体内脑I/R损伤过程中，miR-195-5p显著下调，PTEN上调。miR-195-5p过表达有效提高了细胞活力，同时降低了体外OGD处理的HBMVECs的LDH释放和凋亡率。miR-195-5p可通过直接结合PTEN的3'-UTR对其表达进行负调控。PTEN过表达明显减弱了miR-195-5p模拟物对OGD处理的HBMVECs细胞活力、LDH释放和凋亡的保护作用。同时，miR-195-5p过表达增加了OGD处理的HBMVECs中p-AKT的表达水平，而PTEN过表达则逆转了这种作用。此外，miR-195-5p过表达有效改善了体内MCAO处理后小鼠的脑损伤。
miR-195-5p过表达通过调节PTEN-AKT信号通路改善脑I/R损伤，为脑I/R损伤提供了一个潜在的治疗靶点。
