Department of Neurosurgery, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China.
J Cell Biochem. 2018 Jan;119(1):327-337. doi: 10.1002/jcb.26181. Epub 2017 Sep 22.
Ischemic stroke is the leading cause of disabilities worldwide. MicroRNA-377 (miR-377) plays important roles in ischemic injury. The present study focused on the mechanisms of miR-377 in protecting ischemic brain injury in rats. Cerebral ischemia was induced by middle cerebral artery occlusion (MCAO) in rats. Primary rat microglial cells and brain microvascular endothelial cells (BMECs) were exposed to oxygen-glucose deprivation (OGD). The concentrations of cytokines (TNF-α, IL-1β, IL-6, IFN-γ, TGF-β, MMP2, COX2, and iNOS) in the culture medium were measured by specific ELISA. Tube formation assay was for the in vitro study of angiogenesis. Luciferase reporter assay was performed to confirm whether VEGF and EGR2 were direct targets of miR-377. The MCAO rats were intracerebroventricular (ICV) injection of miR-377 inhibitor to assess its protective effects in vivo. MiR-377 levels were decreased in the rat brain tissues at 1, 3, and 7 d after MCAO. Both microglia cells and BMECs under OGD showed markedly lower expression levels of miR-377 while higher expression levels of EGR2 and VEGF compared to those under normoxia conditions. Knockdown of miR-377 inhibited microglial activation and the release of pro-inflammatory cytokines after OGD. Suppression of miR-377 promoted the capillary-like tube formation and cell proliferation and migration of BMECs. The anti-inflammation effect of EGR2 and the angiogenesis effect of VEGF were regulated by miR-377 after OGD. Inhibition of miR-377 decreased cerebral infarct volume and suppressed cerebral inflammation but promoted angiogenesis in MCAO rats. Knockdown of miR-377 lessened the ischemic brain injury through promoting angiogenesis and suppressing cerebral inflammation. J. Cell. Biochem. 119: 327-337, 2018. © 2017 Wiley Periodicals, Inc.
缺血性脑卒中是全球致残的主要原因。微小 RNA-377（miR-377）在缺血性损伤中发挥重要作用。本研究重点探讨 miR-377 保护大鼠缺血性脑损伤的机制。通过大脑中动脉闭塞（MCAO）诱导大鼠脑缺血。将原代大鼠小胶质细胞和脑微血管内皮细胞（BMEC）暴露于氧葡萄糖剥夺（OGD）中。通过特定的 ELISA 测量培养基中细胞因子（TNF-α、IL-1β、IL-6、IFN-γ、TGF-β、MMP2、COX2 和 iNOS）的浓度。管形成试验用于体外研究血管生成。荧光素酶报告基因检测用于确认 VEGF 和 EGR2 是否为 miR-377 的直接靶标。通过向 MCAO 大鼠脑室内（ICV）注射 miR-377 抑制剂来评估其体内的保护作用。MCAO 后 1、3 和 7 天，大鼠脑组织中 miR-377 水平降低。与正常氧条件相比，OGD 下的小胶质细胞和 BMEC 表现出明显较低的 miR-377 表达水平，而 EGR2 和 VEGF 的表达水平更高。下调 miR-377 抑制 OGD 后小胶质细胞的激活和促炎细胞因子的释放。抑制 miR-377 促进 BMEC 的毛细血管样管形成以及细胞增殖和迁移。OGD 后，miR-377 调节 EGR2 的抗炎作用和 VEGF 的血管生成作用。抑制 miR-377 减少 MCAO 大鼠的脑梗死体积并抑制脑炎症，但促进血管生成。下调 miR-377 通过促进血管生成和抑制脑炎症减轻缺血性脑损伤。J. Cell. Biochem. 119: 327-337, 2018. © 2017 Wiley Periodicals, Inc.
