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Shasha Duan,1– 3,* Chao Wang,1,2,* Xiangli Xu,4 Xiaoshan Zhang,3 Gaofeng Su,1,2 You Li,1,2 Shuai Fu,1,2 Ping Sun,1,2 Jiawei Tian1 1Department of Ultrasound, the Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, People’s Republic of China; 2The Key Laboratory of Myocardial Ischemia, Harbin Medical University, Ministry of Education, Harbin, Heilongjiang Province, People’s Republic of China; 3Department of Ultrasound, The Affiliated Hospital of Inner Mongolia Medical University, Hohhot, People’s Republic of China; 4Department of Ultrasound, the Second Hospital of Harbin city, Harbin, Heilongjiang Province, People’s Republic of China*These authors contributed equally to this workCorrespondence: Jiawei Tian; Ping Sun, Department of Ultrasound, the Second Affiliated Hospital of Harbin Medical University, No. 246 Xuefu Road, Nangang District, Harbin, Heilongjiang Province, 150086, People’s Republic of China, Tel +86 451-86605811, Fax +86 451-86605745, Email jwtian2004@163.com; sunpinghmu@163.comPurpose: Angiogenesis is required for improving myocardial function and is a key factor in long-term prognosis after an acute myocardial infarction (AMI). Although exosomes are known to play a crucial role in angiogenesis, the role of peripheral exosomes in angiogenic signal transduction in patients with AMI remains unclear. Here, we explored the effect of exosomes extracted from the peripheral serum of AMI patients on angiogenesis and elucidated the downstream pathways.Patients and Methods: Serum exosomes were obtained from patients with AMI (AMI-Exo) and healthy individuals (Con-Exo). The exosomes were cocultured with human umbilical vein endothelial cells (HUVECs) in vitro, with aortic rings ex vivo, and were used to treat mouse hind-limb ischemia and mouse AMI model in vivo.Results: AMI-Exo raised HUVEC proliferation, tube formation, and migration, and enhanced microvessel sprouting from aortic rings compared to Con-Exo, both in vitro and ex vivo. Quantitative reverse transcription-polymerase chain reaction revealed that the abundance of miR-126-3p, a crucial regulator of angiogenesis, was increased in AMI-Exo. The inhibition of miR-126-3p decreased the benefits of AMI-Exo treatment, and miR-126-3p upregulation enhanced the benefits of Con-Exo treatment in HUVECs, aortic rings, the mouse hind-limb ischemia model, and the mouse AMI model. Knockdown and overexpression analyses revealed that miR-126-3p regulated angiogenesis in HUVECs by directly targeting tuberous sclerosis complex 1 (TSC1). Moreover, we found that miR-126-3p could inhibit TSC1 expression, which further activated mTORC1 signaling and increased HIF-1α and VEGFA expression, ultimately promoting angiogenesis.Conclusion: Collectively, our results provide a novel understanding of the function of exosomes in angiogenesis post AMI. We demonstrated that exosomes from the peripheral serum of AMI patients promote angiogenesis via the miR-126-3p/TSC1/mTORC1/HIF-1α signaling pathway.Keywords: acute myocardial infarction, angiogenesis, exosomes, miR-126-3p, tuberous sclerosis complex 1 |
