MIR155HG上调NF-κB通路促进间充质干细胞迁移联合外泌体药物传递靶向治疗心脏移植物血管病的机制研究

Cardiac allograft vasculopathy（CAV）is the main cause of transplanted heart dysfunction. The endothelial injury of coronary artery induced by rejection played the vital role in the development of CAV. Mesenchymal stem cells (MSCs) have low immunogenicity and can home to the transplanted organ to promote endothelial repair under the chemotaxis of inflammatory factors. MSCs are expected to become the important strategy for the prevention and control of CAV. MSCs could secrete exosome which contains miRNA and mRNA. The genetic material from exosome could regulate mRNA level and protein translation of target cells, and play the role in improving inflammation and apoptosis. Our previous studies have found that the NF-κB pathway was involved in directional migration of MSCs. And the lncRNA MIR155HG could effectively activate NF-κB pathway. Therefore, we attempted to promote MSCs to home to the sites of vascular injury by up-regulation MIR155HG, and meanwhile use the drug delivery of exosome to promote endothelial repair. This study intends to transfect MSCs with adenovirus vector of MIR155HG in vitro and collect secreted exosome to observe the improving migration of MSCs and the protective effect of exosome on endothelial cells. Then the transfected MSCs and modified exosome were transplanted into the coronary artery of cardiac allograft models. The homing of MSCs, apoptosis of coronary endothelium and intimal hyperplasia will be detected to reveal the role and mechanism of MIR155HG up-regulated MSCs and drug delivery of exosome in prevention and control of CAV.

心脏移植物血管病（CAV）是导致移植心脏功能丧失的主要原因，冠脉内皮损伤是其始动环节。间充质干细胞（MSCs）在炎症趋化下可归巢到移植器官，修复受损血管内皮，有望成为防治CAV的重要策略。MSCs分泌的外泌体富含遗传物质，可调节目的细胞mRNA水平，调控蛋白翻译，改善炎症和凋亡。研究发现NF-κB通路参与了MSCs的迁移过程，并且MIR155HG可有效活化NF-κB通路。因此，我们试图上调MIR155HG以促进MSCs向血管损伤部位迁移，并利用外泌体的药物传递作用，促进损伤内皮修复。我们构建MIR155HG腺病毒载体，体外转染MSCs，并收集外泌体，观察MSCs迁移活性的改善及外泌体对内皮细胞的保护作用。再将经修饰的MSCs及外泌体输注到移植心脏冠状动脉，进行MSCs示踪、冠脉内皮凋亡及内膜增生情况的检测，以揭示MIR155HG上调的MSCs移植及外泌体药物传递在防治CAV中的作用及机制。

心脏移植物血管病（CAV）是导致移植心脏功能丧失的主要原因，冠脉内皮损伤是其始动环节。间充质干细胞（MSCs）在炎症趋化下可归巢到移植器官，修复受损血管内皮，有望成为防治CAV的重要策略。MSCs分泌的外泌体富含遗传物质，可调节目的细胞mRNA水平，调控蛋白翻译，改善炎症和凋亡。但是在应激反应等体内环境中，MSCs的存活能力及生物活性明显减弱，MSCs的治疗效果也显著降低。.因此我们试图利用一种lncRNA来调控MSCs，以增强MSCs的治疗效果。研究发现NF-κB通路参与了MSCs的迁移过程，并且lncRNA MIR155HG可有效活化NF-κB通路。因此，我们试图上调lncRNA MIR155HG以促进MSCs向血管损伤部位迁移，并利用外泌体的药物传递作用，促进损伤内皮修复。我们构建MIR155HG慢病毒载体，体外转染MSCs，并收集外泌体，观察MSCs迁移活性的改善及外泌体对内皮细胞的保护作用。再将经修饰的MSCs及外泌体输注到移植血管，进行MSCs示踪、内皮凋亡及内膜增生情况的检测，以揭示MIR155HG上调的MSCs移植及外泌体药物传递在防治CAV中的作用及机制。.实验中我们模拟体内氧化应激环境，并研究是否lncRNA MIR155HG 可以促进MSCs在该环境中的存活及迁移功能。结果证实，MIR155HG可以通过上调NF‑κB通路调控MSCs的生物活性，并促进MSCs的增殖及迁移功能。MIR155HG也可通过活化NF‑κB通路，明显降低氧化应激诱导的MSCs凋亡。另外，我们还研究了转染MIR155HG的MSCs来源外泌体对于血管内皮细胞的保护作用。结果显示MSCs分泌的富含lncRNA MIR155HG的外泌体可通过胞吞作用被内皮细胞所摄取。上调MIR155HG的外泌体可有效促进血管内皮细胞的迁移，并减轻内皮细胞凋亡。通过动物实验证实，联合应用转染MIR155HG的MSCs及外泌体注射入动物模型体内，可明显减轻移植血管的炎症反应，促进内皮修复，从而有效缓解血管内膜增生。MIR155HG对于MSCs及内皮细胞的生物活性具有强大的调控作用，该分子作为治疗CAV的靶点，具有重要意义及应用前景。