Institute of Neuroscience, Kunming Medical University, Kunming 650500, Yunnan, China; Department of Neurology, Second Affiliated Hospital of Kunming Medical University, Kunming 650101, Yunnan, China.
Institute of Neuroscience, Kunming Medical University, Kunming 650500, Yunnan, China.
Brain Res Bull. 2022 Jul;185:39-48. doi: 10.1016/j.brainresbull.2022.04.006. Epub 2022 Apr 20.
Remote ischemic postconditioning (RIPostC) is a protective procedure for brain damage caused by ischemia/reperfusion (IR), yet the mechanism of this treatment remains to be elucidated. Circular RNAs (circRNAs) are endogenous non-coding RNAs that have recently been recognized to play vital roles in ischemic brain injury. The aim of this study was to explore the role of circRNAs in the protective mechanism of RIPostC and to analyze the circRNA-microRNA (miRNA) regulation network in RIPostC. Nine rats were assigned randomly into three groups (three rats per group): sham, IR, and RIPostC. Their brain tissues were extracted for next-generation RNA sequencing and bioinformatics analysis was performed for two comparisons: sham vs. IR and IR vs. RIPostC. The expression patterns of selected circRNAs and miRNAs were validated by quantitative real-time PCR (qPCR). We detected 82 upregulated and 51 downregulated circRNAs and 137 upregulated and 127 downregulated miRNAs in the IR group compared with the sham group, and 41 upregulated and 100 downregulated circRNAs and 45 upregulated and 64 downregulated miRNAs in the RIPostC group compared with the IR group. The proposed competitive endogenous RNA (ceRNA) network, which included 24 circRNAs, 20 miRNAs, and 145 mRNAs, indicated that the dysregulated circRNAs played important roles in brain IR injury. On the basis of the expression patterns of selected circRNAs, miRNAs, and mRNAs obtained by qPCR, we proposed a circRNA_0002286-miR-124-3p-VLCAD pathway. In PC12 cell, the expression level of miR-124-3p was significantly upregulated when the expression of circRNA_0002286 was repressed and the expression level of VLCAD (very-long chain acyl-CoA dehydrogenase) was significantly downregulated, which suggested that circRNA_0002286 may act as a miRNA sponge for miR-124-3p to regulate the expression of VLCAD. We found that upregulation of circRNA_0002286 attenuated IR injury and was associated with downregulation of miR-124-3p and upregulation of VLCAD. This is the first time that circRNAs have been shown to be closely related to brain IR injury and RIPostC and suggests that targeting the circRNA_0002286-miR-124-3p-VLCAD pathway might attenuate brain IR injury.
远程缺血后处理（RIPostC）是一种针对缺血/再灌注（IR）引起的脑损伤的保护措施，但这种治疗的机制仍有待阐明。环状 RNA（circRNAs）是最近被认为在缺血性脑损伤中发挥重要作用的内源性非编码 RNA。本研究旨在探讨 circRNAs 在 RIPostC 保护机制中的作用，并分析 RIPostC 中的 circRNA-微小 RNA（miRNA）调控网络。将 9 只大鼠随机分为三组（每组 3 只）：假手术组、IR 组和 RIPostC 组。提取其脑组织进行下一代 RNA 测序，并对两个比较进行生物信息学分析：假手术组与 IR 组比较，IR 组与 RIPostC 组比较。通过定量实时 PCR（qPCR）验证选定的 circRNAs 和 miRNAs 的表达模式。与 sham 组相比，IR 组中检测到 82 个上调和 51 个下调的 circRNAs 和 137 个上调和 127 个下调的 miRNAs，与 IR 组相比，RIPostC 组中检测到 41 个上调和 100 个下调的 circRNAs 和 45 个上调和 64 个下调的 miRNAs。所提出的竞争内源 RNA（ceRNA）网络包括 24 个 circRNAs、20 个 miRNAs 和 145 个 mRNAs，表明失调的 circRNAs 在脑 IR 损伤中发挥重要作用。基于 qPCR 获得的选定 circRNAs、miRNAs 和 mRNAs 的表达模式，我们提出了 circRNA_0002286-miR-124-3p-VLCAD 通路。在 PC12 细胞中，当 circRNA_0002286 的表达受到抑制时，miR-124-3p 的表达水平显著上调，而 VLCAD（非常长链酰基辅酶 A 脱氢酶）的表达水平显著下调，这表明 circRNA_0002286 可能作为 miR-124-3p 的 miRNA 海绵来调节 VLCAD 的表达。我们发现，circRNA_0002286 的上调可减轻 IR 损伤，并与 miR-124-3p 的下调和 VLCAD 的上调相关。这是首次表明 circRNAs 与脑 IR 损伤和 RIPostC 密切相关，并表明靶向 circRNA_0002286-miR-124-3p-VLCAD 通路可能减轻脑 IR 损伤。
