Exosomal circHIPK3 Released from Hypoxia-Pretreated Cardiomyocytes Regulates Oxidative Damage in Cardiac Microvascular Endothelial Cells via the miR-29a/IGF-1 Pathway
Exosomal circHIPK3 Released from Hypoxia-Pretreated Cardiomyocytes Regulates Oxidative Damage in Cardiac Microvascular Endothelial Cells via the miR-29a/IGF-1 Pathway
复制标题
缺氧预处理的心肌细胞释放的外泌体 circHIPK3 通过 miR-29a/IGF-1 途径调节心脏微血管内皮细胞的氧化损伤
DOI：
10.1155/2019/7954657
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发表时间：
2019-12-05
影响因子：
--
通讯作者：
Shi, Bei
中科院分区：
文献类型：
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作者：
Wang, Yan;Zhao, Ranzun;Shi, Bei
背景/目的 环状 RNA (circRNA) 是一类调节真核生物基因表达的内源性非编码 RNA。最近，来自心肌细胞（CM）的外泌体被发现可以通过运输各种生物活性分子（包括circRNA）来促进细胞增殖和存活。然而，外泌体circRNA的功能尚不清楚。本研究旨在确定从缺氧预处理的 CM 中释放的 circHIPK3 是否通过外泌体转移到心脏微血管内皮细胞 (CMVEC) 中，并在氧化应激条件下在 CMVEC 中变得功能活跃。方法采用定量聚合酶链反应检测氧化应激下CMVECs中circHIPK3的表达模式。进行Annexin V-FITC/碘化丙啶（PI）染色测定、TUNEL测定、ROS测定和Western印迹分析来检测外泌体circHIPK3在体外CMVEC功能中的作用。体外进行荧光素酶活性测定和 RNA 免疫沉淀研究，以揭示 circHIPK3 介导的 CMVEC 功能的机制。结果 与常氧外泌体 (Nor-exos) 相比，缺氧外泌体 (HPC-exos) 中 circHIPK3 表达显着上调。此外，HPC-exos 比 Nor-exos 诱导更强的抗氧化作用。 circHIPK3 的沉默或过度表达改变了 CMVEC 在体外氧化条件下的存活率。此外，HPC-exos 中的 circHIPK3 沉默消除了 HPC-exos 对 CMVEC 的保护作用，如凋亡、ROS、MDA 和促凋亡蛋白水平增加所示。 circHIPK3 作为内源性 miR-29a 海绵来隔离和抑制 miR-29a 活性，从而导致 IGF-1 表达增加。 miR-29a 的异位表达模拟了体外 CMVEC 中 circHIPK3 沉默的效果。结论 HPC-exos 中的 circHIPK3 通过 miR-29a 介导的 IGF-1 表达在氧化条件下的 CMVEC 中发挥作用，从而减少氧化应激诱导的 CMVEC 功能障碍。这些数据表明，CM 中的外泌体 circRNA 是氧化条件下控制 CMVEC 功能障碍的潜在靶点。
Background/Aims Circular RNAs (circRNAs) are a class of endogenous noncoding RNAs that regulate gene expression in eukaryotes. Recently, exosomes from cardiomyocytes (CMs) have been found to facilitate cell proliferation and survival by transporting various bioactive molecules, including circRNA. However, the functions of exosomal circRNAs are not clear. The present research is aimed at determining whether circHIPK3 released from hypoxia-pretreated CMs is transferred into cardiac microvascular endothelial cells (CMVECs) by exosomes and becomes functionally active in the CMVECs under oxidative stress conditions. Methods Quantitative polymerase chain reactions were conducted to detect the expression pattern of circHIPK3 in CMVECs under oxidative stress. Annexin V-FITC/propidium iodide (PI) staining assays, TUNEL assays, ROS assays, and Western blot analysis were conducted to detect the role of exosomal circHIPK3 in CMVEC function in vitro. Luciferase activity assays and RNA immunoprecipitation studies were conducted in vitro to reveal the mechanism of circHIPK3-mediated CMVEC function. Results circHIPK3 expression was significantly upregulated in hypoxic exosomes (HPC-exos) compared with normoxic exosomes (Nor-exos). Moreover, HPC-exos induced stronger antioxidant effects than Nor-exos. The silencing or overexpression of circHIPK3 changed CMVEC survival under oxidative conditions in vitro. Furthermore, circHIPK3 silencing in HPC-exos abrogated the protective effects of HPC-exos in CMVECs, as shown by increased levels of apoptosis, ROS, MDA, and proapoptotic proteins. circHIPK3 acted as an endogenous miR-29a sponge to sequester and inhibit miR-29a activity, which led to increased IGF-1 expression. The ectopic expression of miR-29a mimicked the effect of circHIPK3 silencing in CMVECs in vitro. Conclusions circHIPK3 in HPC-exos plays a role in CMVECs under oxidative conditions through miR-29a-mediated IGF-1 expression, leading to a decrease in oxidative stress-induced CMVECs dysfunction. These data suggest that the exosomal circRNA in CMs is a potential target to control CMVECs dysfunction under oxidative conditions.