Cerebral stroke is a major cause of brain injury due to the production of hypoxic conditions, and new therapeutic interventions are required for its management. Here, we evaluated the protective effect of miR-668 inhibitor against ischemia/reperfusion (I/R)-induced stroke. Cerebral stroke was induced by cerebral artery occlusion in rats, followed by treatment with miR-668 inhibitor for 10 minutes before reperfusion. The neuroprotective effect of miR-668 inhibitor was determined by estimating the neurological deficit score, cerebral infarct area and blood-brain barrier (BBB) permeability. In addition, the levels of inflammatory cytokines, and the expression of NLRP3, zonula occludens-1 (ZO-1), dynamin-related protein 1 (Drp1) and occludin proteins, were estimated by ELISA and Western blotting, respectively. TUNEL assay and immunohistochemical analyses were performed to examine the effects of miR-668 inhibitor against I/R-induced stroke rats. The miR-668 inhibitor treatment group showed reductions in the infarct area, BBB permeability and neurological score compared to the stroke group. The levels of cytokines and reactive oxygen species were reduced in the miR-668 inhibitor treatment group compared to the stroke group. These observations suggested that inhibition of miR-668 reduces neuronal apoptosis by ameliorating the expression of caspase 3, Bax and Bcl-2 protein in I/R stroke rats. The expression of NLRP3, ZO-1 and occludin proteins was attenuated in the brain tissue of the miR-668 inhibitor treatment group compared to the stroke group. Moreover, the phosphorylation of Drp1 protein was reduced in the miR-668 inhibitor group compared to the stroke group. In conclusion, the results of the present study indicated that inhibition of miR-668 prevented neuronal apoptosis in cerebral I/R-induced stroke by modulating mitochondrial function and regulating NLRP3 signalling.

中文翻译：

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miR-668抑制剂可减弱线粒体膜电位并防止脑缺血性中风的神经元凋亡。

脑缺氧是由于缺氧导致的脑损伤的主要原因，因此需要新的治疗方法来治疗。在这里，我们评估了miR-668抑制剂对缺血/再灌注（I / R）诱发的中风的保护作用。大鼠脑动脉阻塞可诱发脑中风，然后在再灌注前用miR-668抑制剂治疗10分钟。通过评估神经功能缺损评分，脑梗死面积和血脑屏障（BBB）通透性来确定miR-668抑制剂的神经保护作用。另外，分别通过ELISA和Western印迹法评估了炎性细胞因子的水平，以及NLRP3，小带闭合蛋白-1（ZO-1），动力蛋白相关蛋白1（Drp1）和闭合蛋白的表达。进行了TUNEL测定和免疫组化分析以检查miR-668抑制剂对I / R诱导的中风大鼠的作用。与中风组相比，miR-668抑制剂治疗组显示梗塞面积，BBB通透性和神经学评分降低。与中风组相比，miR-668抑制剂治疗组的细胞因子和活性氧水平降低。这些观察结果表明，抑制miR-668可通过改善I / R中风大鼠中caspase 3，Bax和Bcl-2蛋白的表达来减少神经元凋亡。与中风组相比，miR-668抑制剂治疗组的脑组织中NLRP3，ZO-1和闭合蛋白的表达减弱。此外，与中风组相比，miR-668抑制剂组中Drp1蛋白的磷酸化降低。总之，本研究结果表明，抑制miR-668可以通过调节线粒体功能和调节NLRP3信号传导来阻止脑I / R诱发的中风的神经元凋亡。