【罂粟摘要】HUVECs分泌的外泌体通过抑制miR-21-3p来减弱缺氧/复氧诱导的神经细胞凋亡
HUVECs分泌的外泌体通过抑制miR-21-3p来减弱缺氧/复氧诱导的神经细胞凋亡
贵州医科大学 高鸿教授课题组
翻译：安丽 编辑：佟睿 审校：曹莹
远端缺血后处理（RIPostC）是防止重要器官因缺血/再灌注损伤而受损的有效策略。在目前的研究中，研究了远端外泌体转移microRNAs (miRs)如何影响RIPostC对中枢神经系统(CNS)的治疗效果。
将人脐静脉内皮细胞(HUVECs)进行低氧/复氧(H/R)处理，采用微阵列法研究其miR表达谱。通过靶基因的基因本体论(GO)注释和京都基因与基因组百科全书(KEGG)路径分析，分析与miRs失调相关的途径。进一步研究发现，在huvec衍生的外泌体对H/ r处理的神经细胞的保护作用中，miR-21-3p的下调最为显著。然后通过聚焦自噬相关12 (autophagy related 12, ATG12)蛋白的活性来探索miR-21-3p作用的途径。
H/R后HUVECs的 miR表达谱发生显著变化，其中104个miR表达上调，249个miR表达下调。根据GO和KEGG分析，筛选出的8个miRs的靶基因参与了多个生物通路，包括hippo信号通路和寿命调节通路。进一步的研究表明，huvec衍生的外泌体或特异性抑制剂抑制miR-21-3p可以阻断H/R处理的神经细胞凋亡过程。分子水平研究表明，miR-21-3p的抑制作用依赖于ATG12功能的恢复，从而激活自噬，抑制凋亡。
H/R诱导HUVECs外泌体miR表达明显改变，外泌体通过抑制miR-21-3p保护神经元免受H/R损伤。
Exosomes secreted by HUVECs attenuate hypoxia/reoxygenation-induced apoptosis in neural cells by suppressing miR-21-3p
Background: Remote ischemic postconditioning (RIPostC) is an effective strategy for preventing key organs from becoming impaired due to an ischemia/reperfusion injury. In the current study, we investigated how remote exosome transfer of microRNAs (miRs) may contribute to the treatment effect of RIPostC on the central nerve system (CNS).
Methods: Human umbilical vein endothelial cells (HUVECs) were subjected to hypoxia/reoxygenation (H/R) and their miR expression profiles were investigated using the microarray method. The pathways associated with dysregulated miRs were analyzed by gene ontology (GO) annotation of the target genes and a Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. The role played by the most significantly down-regulated miR (miR-21-3p) in the protective effect of HUVEC-derived exosomes on H/R-treated neural cells was further investigated. The pathway mediating the effect of miR-21-3p was then explored by focusing on activity of autophagy-related 12 (ATG12) protein.
Results: The miR expression profile of HUVECs significantly changed after H/R administration, with 104 miRs becoming upregulated and 249 miRs becoming downregulated. Based on the GO and KEGG analyses, the target genes of 8 selected miRs were involved in multiple biological pathways, including the hippo signaling pathway and longevity regulating pathway. Further studies showed that inhibition of miR-21-3p by HUVEC-derived exosomes or a specific inhibitor could the block apoptotic process in H/R-treated neural cells. Molecular level studies showed that the effect of miR-21-3p inhibition depended on the restored function of ATG12, which resulted in the activation of autophagy and suppression of apoptosis.
Conclusion: Taken together, these results suggest that H/R caused significant changes of miR expression in exosomes derived from H/R-treated HUVECs, and the exosomes protect neurons against H/R-induced injuries by suppressing miR-21-3p.