移植物炎症因子-1表达促晚发育内皮细胞增殖和迁移及其机制研究

Some variety of cells, in an immune or inflammatory environment or at culture, express or overexpress allograft inflammatory factor-1 (AIF-1), resulting in enhancement of their migratory and proliferative abilities. For this reason AIF-1 expressed in vascular endothelial cells (ECs) is thought to taking part in the occurrence and development of restenosis. Late-outgrowth ECs (OECs) are a type of endothelial progenitor cells in the body and are rare and diffused. Our recently published results have showed that transfusion of autologous OECs amplified in vitro by culture could accelerate the endothelial repair and ameliorate the abnormal AIF-1 expression in vascular wall after injury, leading to inhibition of the restenosis. Therefore, we propose the novel hypothesis that AIF-1 expression promotes the proliferation and migration of OECs to involve in the endothelial repair. The study applying will test the hypothesis. It will verify, by decreasing AIF-1 expression via RNA interference and increasing AIF-1 expression via gene transfection plus serum inducement, that AIF-1 expression promotes the proliferation and migration of OECs. It will verify that AIF-1 overexpression enhances the amplifying, homing and endothelium-repairing efficacies of OECs. It will determine roles AIF-1 plays in the transduction, in OECs, of proliferation and migration signals, induced by vascular endothelial growth factor-A (VEGF-A,also known as VEGF) via its membrane receptor, VEGFR2. The achievement of the study might advance the understandings of the actions of AIF-1 and the transduction of VEGF-A/VEGFR2 signaling in cytoplasm, and might provide a way to simplify the preparation of OECs to facilitate the autologous OECs therapy.

某些种类细胞在免疫或炎症环境下或培养时表达或过表达移植物炎症因子-1（AIF-1）促其迁移和增殖。故血管内皮细胞表达AIF-1被认为参与再狭窄形成。晚发育内皮细胞（OECs）是一种内皮前体细胞，稀有且散在分布体内。我们前期研究证明输入培养扩增的自体OECs可加快内皮修复，改善血管壁AIF-1异常表达，防止再狭窄。据此提出AIF-1表达促OECs增殖和迁移，参与修复内皮新假说。本项目拟验证之。通过沉默表达（RNA干扰）和过表达（基因转染加血清诱导）验证AIF-1促OECs增殖、迁移；验证过表达AIF-1促OECs扩增、归巢及修复内皮；初步研究AIF-1在血管内皮生长因子-A（VEGF-A）通过膜受体VEGFR2诱导OECs增殖、迁移的信号转导中的作用。研究成果将丰富对AIF-1作用和对VEGF-A/VEGFR2信号胞内转导的认识；还有望简化OECs准备，便于临床实施自体OECs回输抗再狭窄。

晚发育内皮细胞（OECs）是一种内皮前体细胞，稀有且散在分布体内。我们此前已证明OECs参与修复内皮并通过旁分泌控制VSMCs排列，血管成形术后早期输入自体OECs防止再狭窄。但作为稀有细胞，OECs扩增成本高，且取种子细胞须抽取大量血或骨髓，不方便。某些种类细胞在免疫或炎症环境下或在体外培养时表达或过表达移植物炎症因子-1（AIF-1）促其迁移和增殖，血管内皮细胞表达AIF-1被认为参与再狭窄形成。本研究项目提出并验证AIF-1促OECs增殖、迁移，利用高表达AIF-1提高OECs扩增、归巢及修复内皮效率。我们通过腺病毒转导AIF-1 siRNA和cDNA分别敲减或增加OECs表达AIF-1，取得以下主要成：1）证明了AIF-1表达参与OECs增殖和迁移过程；2）证明了AIF-1过表达提高OECs扩增效率；3）证明了利用过表达AIF-1扩增的OECs自体回输，其归巢和内皮修复能力增强，有效防止再狭窄，新内皮不表达AIF-1；4）证明了AIF-1是通过接头或招募作用参与VEGF-A/VEGFR2诱导OECs增殖和迁移的胞浆内信号转导。该研究成果提示可通过AIF-1高表达加快OECs体外数量扩增和体内内皮修复，有助于临床实施自体OECs回输抗再狭窄，有应用价值；该研究成果证明AIF-1作为支架蛋白参与VEGF-A/VEGFR2诱导的OECs迁移和增殖信号转导，丰富了对AIF-1生物意义的了解，也是首次正面理解AIF-1的作用。此外，本项目实施中设计的利用兔耳中动脉实时观察荧光标记血管干细胞归巢、粘附受损血管壁的方法以及以压簧为核心的离体器官恒压灌流支架分别在相关生物医学研究中有普遍适用性。