VSMCs源性外泌体miRNAs介导内皮损伤在糖尿病血管重构中的作用及机制研究

Vascular remodeling is the common pathological basis of diabetic vascular complications and the injury of vascular endothelial cells (ECs) is a major cause of vascular remodeling. Exosome miRNAs play an important role in cell communication. It has been demonstrated that exosomes derived from vascular smooth muscle cells (VSMCs) are involved in the development of vascular proliferative diseases. However, it is not clear whether VSMCs-derived exosomes could participate in diabetic vascular remodeling by injurying ECs through carrying miRNAs. Previously, we have demonstrated that VSMCs may influence ECs function by secreting exosome miRNA-24. The present study aims to investigate VSMCs-derived exosome miRNAs (1) effects on the proliferation, migration and repair of ECs;(2) mechanism in regulating the biological activities of ECs; (3) effects on reendothelialization of injured vascular endothelium in diabetic rats. The ultimate purpose of this study is to elucidate the biological information transmission of VSMCs-derived exosome miRNAs between VSMCs and ECs under high glucose condition and determine their target genes, which will present a new clue for early prevention and treatment of diabetic vascular remodeling.

血管重构是糖尿病血管并发症的共同病理基础，内皮细胞（ECs）损伤是引起血管重构的重要原因。细胞分泌的外泌体可通过携带miRNAs在细胞间发挥信息传递作用。已有研究证实血管平滑肌细胞（VSMCs）源性外泌体miRNAs参与了血管增生性疾病的发生发展，但VSMCs源性外泌体miRNAs是否可通过介导内皮损伤而参与糖尿病血管重构尚不清楚。我们既往研究提示VSMCs可能通过分泌外泌体miRNA-24而影响ECs功能。因此，本研究将从细胞和动物水平进一步探讨：VSMCs源性外泌体miRNAs（1）对ECs增殖、迁移及修复功能的影响；（2）对ECs细胞功能学调控的分子机制；（3）对球囊损伤后的糖尿病大鼠颈动脉内皮修复的影响。以上研究，旨在阐明高糖条件下VSMCs源性外泌体miRNAs在VSMCs与ECs间的信息传递作用，并明确其在ECs内发挥生物学调节作用的靶基因，从而为糖尿病血管重构的防治提供新靶点。

血管重构是糖尿病血管并发症的共同病理基础，内皮细胞（ECs）损伤是引起血管重构的重要原因。细胞分泌的外泌体可通过携带miRNAs在细胞间发挥信息传递作用，研究血管平滑肌细胞（VSMCs）源性外泌体miRNAs对内皮功能的影响及机制对于防治糖尿病血管并发症具有重大意义。本课题组结合前期研究基础，以VSMCs、ECs及糖尿病大鼠为研究对象：（1）观察VSMCs源性外泌体中miRNAs的表达情况；（2）探索VSMCs源性外泌体对ECs功能的影响及机制；（3）探索VSMCs源性外泌体中差异表达的miRNAs对球囊损伤后的糖尿病大鼠颈动脉内皮修复的影响及机制。目前已取得的研究结果如下：（1）完成高糖刺激VSMCs源性外泌体透射电子显微镜的观察及鉴定，同时测序获得VSMCs源性外泌体中miRNAs的表达变化情况；（2）发现高糖刺激VSMCs分泌的外泌体与ECs共孵育后，可明显抑制ECs的迁移能力，结合miRNAs的表达变化，进一步研究证实miRNA-486/PIK3R1/AKT信号通路参与了该过程；（3）结合miRNAs的表达变化，证实miRNA-24可通过调节NLRP3/caspase-1/IL-1β及PI3K/Akt信号轴的表达而有效抑制糖代谢异常血管损伤后的炎症反应及血管内膜增生，并促进内皮修复。总之，本项目研究结果表明，高糖刺激VSMCs分泌的外泌体miRNAs（如miRNA-24、miRNA-486）可通过影响ECs功能而参与调节糖尿病血管重构，这进一步深化了对糖尿病血管重构发病机制的认识，通过改变相关miRNAs的表达水平可为糖尿病血管重构的防治提供新的干预靶点。