Hypoxic-ischemic brain damage (HIBD) is a relatively common malignant complication that occurs in newborn infants, but promising therapies remain limited. In this study, we focused on the role of miR-326 and its target gene δ-opioid receptor (DOR) in the pathogenesis of neonatal HIBD. The expression levels of miR-326 and DOR after hypoxic-ischemic injury were examined both in vivo and in vitro. The direct relationship between miR-326 and DOR was confirmed by a dual-luciferase reporter assay. Further, effects of miR-326 on cell viability and apoptosis levels under oxygen glucose deprivation (OGD) were analyzed. The expression levels of miR-326 were significantly lower and DOR levels were significantly higher in the HIBD group than the control group both in vivo and in vitro. Overexpression of miR-326 downregulated the expression of DOR, while suppression of miR-326 upregulated the expression of DOR. The dual-luciferase reporter assay further confirmed that DOR could be directly targeted and regulated by miR-326. MiR-326 knockdown improved cell survival and decreased cell apoptosis by decreasing the expression levels of Caspase-3 and Bax and increasing Bcl-2 expression in PC12 cells after exposure to OGD. Moreover, DOR knockdown rescued the effect of the improved cell survival and suppressed cell apoptosis induced by silencing miR-326. Our findings indicated that inhibition of miR-326 may improve cell survival and decrease cell apoptosis in neonatal HIBD through the target gene DOR.

中文翻译：

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通过靶向δ阿片受体，miR-326在新生儿缺氧缺血性脑损伤发病机制中的作用。

新生儿缺氧缺血性脑损伤（HIBD）是一种相对常见的恶性并发症，但有希望的疗法仍然有限。在这项研究中，我们集中于miR-326及其靶基因δ阿片受体（DOR）在新生儿HIBD发病机理中的作用。在体内和体外检查了缺氧缺血性损伤后miR-326和DOR的表达水平。miR-326和DOR之间的直接关系已通过双重萤光素酶报告基因测定得以证实。此外，分析了miR-326对氧葡萄糖剥夺（OGD）下细胞活力和凋亡水平的影响。在体内和体外，HIBD组的miR-326的表达水平明显低于对照组，而DOR的水平则明显高于对照组。miR-326的过表达下调了DOR的表达，而抑制miR-326则上调DOR的表达。双重荧光素酶报告基因测定法进一步证实，DOR可以直接被miR-326靶向和调控。通过降低Caspase-3和Bax的表达水平以及增加OGD暴露后PC12细胞中Bcl-2的表达，MiR-326的组合降低了细胞的存活率并降低了细胞的凋亡。此外，DOR组合式挽救了通过沉默miR-326诱导的细胞存活率提高和抑制细胞凋亡的作用。我们的发现表明，通过靶基因DOR抑制miR-326可改善新生儿HIBD中的细胞存活率并减少细胞凋亡。通过降低Caspase-3和Bax的表达水平以及增加OGD暴露后PC12细胞中Bcl-2的表达，MiR-326的组合降低了细胞的存活率并降低了细胞的凋亡。此外，DOR组合式挽救了通过沉默miR-326诱导的细胞存活率提高和抑制细胞凋亡的作用。我们的发现表明，通过靶基因DOR抑制miR-326可改善新生儿HIBD中的细胞存活率并减少细胞凋亡。通过降低Oasp暴露后PC12细胞中Caspase-3和Bax的表达水平以及增加Bcl-2的表达，MiR-326的组合降低了细胞的存活率并降低了细胞的凋亡。此外，DOR组合式挽救了沉默miR-326诱导的细胞存活率提高和抑制细胞凋亡的作用。我们的发现表明，通过靶基因DOR抑制miR-326可改善新生儿HIBD中的细胞存活率并减少细胞凋亡。