Departments of Physiology and Pharmacology, Center for Basic and Translational Stroke Research; West Virginia University, Morgantown, West Virginia, 26506, USA.
Experimental Stroke Core, Center for Basic and Translational Stroke Research; West Virginia University, Morgantown, West Virginia, 26506, USA.
Sci Rep. 2020 Feb 24;10(1):3233. doi: 10.1038/s41598-020-59997-y.
Blood-brain barrier (BBB) dysfunction occurs in cerebrovascular diseases and neurodegenerative disorders such as stroke. Opening of the BBB during a stroke has a negative impact on acute outcomes. We have recently demonstrated that miR-34a regulates the BBB by targeting cytochrome c (CYC) in vitro. To investigate the role of miR-34a in a stroke, we purified primary cerebrovascular endothelial cells (pCECs) from mouse brains following 1 h transient middle cerebral artery occlusion (tMCAO) and measured real-time PCR to detect miR-34a levels. We demonstrate that the miR-34a levels are elevated in pCECs from tMCAO mice at the time point of BBB opening following 1 h tMCAO and reperfusion. Interestingly, knockout of miR-34a significantly reduces BBB permeability, alleviates disruption of tight junctions, and improves stroke outcomes compared to wild-type (WT) controls. CYC is decreased in the ischemic hemispheres and pCECs from WT but not in miR-34a mice following stroke reperfusion. We further confirmed CYC is a target of miR-34a by a dural luciferase reporter gene assay in vitro. Our study provides the first description of miR-34a affecting stroke outcomes and may lead to discovery of new mechanisms and treatments for cerebrovascular and neurodegenerative diseases such as stroke.
血脑屏障（BBB）功能障碍发生在脑血管疾病和神经退行性疾病中，如中风。中风期间 BBB 的开放对急性结果有负面影响。我们最近证明，miR-34a 通过靶向细胞色素 c（CYC）在体外调节 BBB。为了研究 miR-34a 在中风中的作用，我们在 1 小时短暂性大脑中动脉闭塞（tMCAO）后从小鼠脑中纯化原代脑血管内皮细胞（pCEC），并测量实时 PCR 以检测 miR-34a 水平。我们证明，在 1 小时 tMCAO 和再灌注后 BBB 开放时，tMCAO 小鼠的 pCEC 中 miR-34a 水平升高。有趣的是，与野生型（WT）对照相比，miR-34a 敲除显着降低 BBB 通透性，减轻紧密连接的破坏，并改善中风结果。CYC 在缺血半球和 WT 但不是 miR-34a 小鼠的 pCEC 中减少中风再灌注后。我们通过体外硬膜荧光素酶报告基因测定进一步证实 CYC 是 miR-34a 的靶标。我们的研究首次描述了 miR-34a 影响中风结果，并可能为中风等脑血管和神经退行性疾病的新机制和治疗方法的发现提供依据。
