Exosomes from linc00511-Overexpressing ADSCs Accelerates Angiogenesis in Diabetic Foot Ulcers Healing by Suppressing of PAQR3-Induced Twist1 Degradation

Abstract

Background: Exosomes from ADSCs (adipose-derived stem cells) possess various therapeutic effects, but their roles in diabetic foot ulcers are poorly understood. We aimed to investigate the role of ADSCs-derived exosomes on regulating angiogenesis in diabetic foot ulcers healing. Methods: EPCs (endothelial progenitor cells) from human peripheral blood were applied as in vitro model of angiogenesis. Exosomes isolated from ADSCs culture medium were characterized by electron microscopy, size distribution and biomarker expression. Cell proliferation, migration, apoptosis and angiogenesis were detected by CCK-8 and EdU staining, wound healing, flow cytometry and tube formation assays, respectively. Expression of inflammatory factors and related genes in serum and cell culture or tissues were detected by ELISA, IF, qRT-PCR and western blotting as appropriate. The PAQR3-BTRC-Twist1 interaction was verified using Co-immunoprecipitation. Rat diabetic foot model was further constructed for the evaluation of wound healing and histological alterations. Findings: EPCs from diabetes showed suppressed proliferation, migration and angiogenesis and decreased Twist1 protein. Similarly, high glucose repressed the proliferation, migration and angiogenesis of EPCs, which also elevated PAQR3 and suppressed Twist1 expression. However, these impaired EPCs biological functions were recovered by the application of exosomes from linc00511-overexpressing ADSCs, along with increased Twist1 and decreased PAQR3. Mechanistically, PAQR3 overexpression reduced Twist1 protein level in EPCs by enhancing BTRC-mediated Twist1 ubiquitin degradation. Exosomes from linc00511-overexpressing ADSCs alleviated rat diabetic foot ulcers by inhibiting Twist1 ubiquitination to promote angiogenesis. Interpretation: Exosomes from linc00511-overexpressing ADSCs promotes diabetic foot ulcers healing by accelerating angiogenesis via suppressing PAQR3-induced Twist1 ubiquitin degradation. Funding Statement: None. Declaration of Interests: The authors declare that there is no conflict of interest. Ethics Approval Statement: The study with human blood samples were approved by the Ethics Committee of Central South University (Changsha, China). Written informed consents were obtained from all DM patients and volunteers before blood sample collection. Above animal operations were approved by the Research Animal Ethics Committee of Central South University and carried out following the Guide for the Care and Use of Laboratory Animals (NIH).