Myocardial infarction (MI) is a severe disease that often associated with dysfunction of angiogenesis. Cell-based therapies for MI using mesenchymal stem cell (MSC)-derived exosomes have been well studied due to their strong proangiogenic effect. Genetic modification is one of the most common methods to enhance exosome therapy. This study investigated the proangiogenic and cardioprotective effect of exosomes derived from hypoxia-inducible factor 1-alpha (HIF-1α)-modified MSCs. Lentivirus containing HIF-1α overexpressing vector was packaged and used to infect MSCs. Exosomes were isolated from MSC-conditioned medium by ultracentrifugation. Human umbilical vein endothelial cells (HUVECs) were treated under hypoxia condition for 48 h co-cultured with PBS, control exosomes, or HIF-1α-overexpressed exosomes, respectively. Then the preconditioned HUVECs were subjected to tube formation assay, Transwell assay, and EdU assay to evaluate the protective effect of exosomes. Meanwhile, mRNA and secretion levels of proangiogenic factors were measured by RT-qPCR and ELISA assays. In vivo assays were conducted using the rat myocardial infarction model. PBS, control exosomes, or HIF-1α-overexpressed exosomes were injected through tail vein after MI surgery. Heart function was assessed by echocardiography at days 3, 14, and 28. At day 7, mRNA and protein expression levels of proangiogenic factors in the peri-infarction area and circulation were evaluated, respectively. At day 28, hearts were collected and subjected to H&E staining, Masson’s trichrome staining, and immunofluorescent staining. HIF-1α-overexpressed exosomes rescued the impaired angiogenic ability, migratory function, and proliferation of hypoxia-injured HUVECs. Simultaneously, HIF-1α-overexpressed exosomes preserved heart function by promoting neovessel formation and inhibiting fibrosis in the rat MI model. In addition, both in vitro and in vivo proangiogenic factors mRNA and protein expression levels were elevated after HIF-1α-overexpressed exosome application. HIF-1α-overexpressed exosomes could rescue the impaired angiogenic ability, migration, and proliferation of hypoxia-pretreated HUVECs in vitro and mediate cardioprotection by upregulating proangiogenic factors and enhancing neovessel formation.

中文翻译：

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间充质干细胞衍生的外泌体中 HIF-1α 过表达通过增强血管生成介导心肌梗死的心脏保护作用。

心肌梗死（MI）是一种严重的疾病，通常与血管生成功能障碍有关。使用间充质干细胞 (MSC) 衍生的外泌体进行基于细胞的 MI 疗法由于其强大的促血管生成作用而得到了很好的研究。基因改造是增强外泌体治疗的最常用方法之一。本研究调查了源自缺氧诱导因子 1-α (HIF-1α) 修饰的 MSCs 的外泌体的促血管生成和心脏保护作用。将含有 HIF-1α 过表达载体的慢病毒包装并用于感染 MSCs。通过超速离心从 MSC 条件培养基中分离外泌体。人脐静脉内皮细胞 (HUVEC) 在缺氧条件下处理 48 小时，分别与 PBS、对照外泌体或 HIF-1α 过表达的外泌体共培养。然后对预处理的 HUVECs 进行管形成试验、Transwell 试验和 EdU 试验，以评估外泌体的保护作用。同时，通过 RT-qPCR 和 ELISA 测定法测量促血管生成因子的 mRNA 和分泌水平。使用大鼠心肌梗塞模型进行体内测定。MI手术后通过尾静脉注射PBS、对照外泌体或HIF-1α过表达的外泌体。在第 3、14 和 28 天通过超声心动图评估心脏功能。在第 7 天，分别评估了梗死周围区域和循环中促血管生成因子的 mRNA 和蛋白质表达水平。在第 28 天，收集心脏并进行 H&E 染色、Masson 三色染色和免疫荧光染色。HIF-1α 过表达的外泌体挽救了受损的血管生成能力，迁移功能和缺氧损伤 HUVECs 的增殖。同时，HIF-1α 过表达的外泌体通过促进新血管形成和抑制大鼠 MI 模型中的纤维化来保持心脏功能。此外，在 HIF-1α 过表达的外泌体应用后，体外和体内促血管生成因子 mRNA 和蛋白质表达水平均升高。HIF-1α 过表达的外泌体可以在体外挽救缺氧预处理的 HUVECs 受损的血管生成能力、迁移和增殖，并通过上调促血管生成因子和增强新血管形成来介导心脏保护。应用 HIF-1α 过表达的外泌体后，体外和体内促血管生成因子 mRNA 和蛋白质表达水平均升高。HIF-1α 过表达的外泌体可以在体外挽救缺氧预处理的 HUVECs 受损的血管生成能力、迁移和增殖，并通过上调促血管生成因子和增强新血管形成来介导心脏保护。应用 HIF-1α 过表达的外泌体后，体外和体内促血管生成因子 mRNA 和蛋白质表达水平均升高。HIF-1α 过表达的外泌体可以在体外挽救缺氧预处理的 HUVECs 受损的血管生成能力、迁移和增殖，并通过上调促血管生成因子和增强新血管形成来介导心脏保护。