Cardio-renal Exosomes in Myocardial Infarction Serum Regulate Proangiogenic Paracrine Signaling in Adipose Mesenchymal Stem Cells
Cardio-renal Exosomes in Myocardial Infarction Serum Regulate Proangiogenic Paracrine Signaling in Adipose Mesenchymal Stem Cells
复制标题
心肌梗死血清中的心肾外泌体调节脂肪间充质干细胞中的促血管生成旁分泌信号传导
DOI：
10.7150/thno.37678
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发表时间：
2020-01-01
期刊：
影响因子：
12.4
通讯作者：
Zhu, Hongming
中科院分区：
文献类型：
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作者：
Gao, Lei;Mei, Shuya;Zhu, Hongming
基本原理：间充质干细胞（MSCs）在组织修复和再生中发挥重要作用。然而，MSC激活的分子机制在很大程度上仍然未知，从而阻碍了它们的临床转化。外泌体是作为细胞间信使的小囊泡，其在病理条件下激活干细胞的潜力尚未完全表征。在这里，我们的目的是研究血清外泌体是否参与心肌梗死（MI）后MSC的远程激活。方法：采用结扎冠状动脉左前降支分支的方法建立小鼠心肌梗死模型。然后，通过差速离心从对照（Con Exo）和MI小鼠（MI Exo）分离血清外泌体。通过透射电子显微镜和纳米颗粒跟踪分析表征外泌体。CCK-8和EdU掺入法检测细胞增殖率。分别使用qRT-PCR和蛋白质印迹法评估外泌体miRNA和蛋白质水平。通过ELISA定量上清液和血清中的VEGF水平。基质胶塞和管形成测定用于评估血管生成。为了探索miR-1956的作用，分别使用模拟物和抑制剂进行过表达和敲低实验。最后，使用荧光素酶报告基因测定确认miR-1956靶基因。结果：两种exosomes均具有典型的细胞学特征，并能被脂肪来源的间充质干细胞（adipose-derived MSCs，ADMSCs）内化。MI Exo通过激活ERK 1/2促进ADMSCs增殖。功能获得和功能丧失研究允许验证miR-1956（在MI Exo中富集）作为通过下调Notch-1刺激ADMSC介导的血管生成和旁分泌VEGF信号传导的功能性信使。最后，我们发现缺血心肌和肾脏可能是MI后血清exosomes释放的主要来源。结论：MI后ADMSC中的肾外泌体递送miR-1956并激活旁分泌促血管生成VEGF信号传导;该过程还涉及Notch-1，其作为核心介质发挥作用。
Rationale: Mesenchymal stem cells (MSCs) play important roles in tissue repair and regeneration. However, the molecular mechanisms underlying MSCs activation remain largely unknown, thus hindering their clinical translation. Exosomes are small vesicles that act as intercellular messengers, and their potential for stem cell activation in pathological conditions has not been fully characterized yet. Here, we aim to investigate whether serum exosomes are involved in the remote activation of MSCs after myocardial infarction (MI). Methods: We established MI mouse model by ligating the left anterior descending branch of the coronary artery. Afterwards, serum exosomes were isolated from control (Con Exo) and MI mice (MI Exo) by differential centrifugation. Exosomes were characterized through transmission electron microscopy and nanoparticle tracking analysis. The cell proliferation rate was evaluated by CCK-8 and EdU incorporation assays. Exosomal miRNA and protein levels were assessed using qRT-PCR and western blotting, respectively. VEGF levels in the supernatant and serum were quantified by ELISA. Matrigel plug and tube formation assays were used to evaluate angiogenesis. To explore miR-1956 roles, overexpression and knock-down experiments were performed using mimic and inhibitor, respectively. Finally, miR-1956 target genes were confirmed using the luciferase reporter assay. Results: Both types of exosomes exhibited typical characteristics and could be internalized by adipose-derived MSCs (ADMSCs). MI Exo enhanced ADMSCs proliferation through the activation of ERK1/2. Gain- and loss-of-function studies allowed the validation of miR-1956 (enriched in MI Exo) as the functional messenger that stimulates ADMSCs-mediated angiogenesis and paracrine VEGF signaling, by downregulating Notch-1. Finally, we found that the ischemic myocardium and kidney may be the main sources that release serum exosomes after MI. Conclusions: Cardio-renal exosomes deliver miR-1956 and activate paracrine proangiogenic VEGF signaling in ADMSCs after MI; this process also involves Notch-1, which functions as the core mediator.