活化转录因子3在静脉桥血管再狭窄早期内皮功能失调中的作用及调控机制的研究

The incidence of vein graft failure after coronary artery bypass grafting is high, and its pathogenesis processes is not clear and lack of effective interventions. Endothelial dysfunction induced by mechanical stretch is the key factor. Some researches revealed that transcription factors play an important role in vein graft failure, which may be the new therapy targets. Our previous study found that ATF3 expression increased significantly in endothelium of vein graft failure, and we found ATF3 may be involved in vein graft failure pathological process via MAPK pathway by using bioinformatic analysis. Therefore, we put forward the hypothesis:“ATF3 promotes vascular inflammation, inducing vein graft failure”. This project aims to detect ATF3 and inflammatory factor expression in patients with vein graft failure; using new CRISPR/Cas9 technique to build ATF3 silence and overexpressed endothelial cells, then observing the cell function, the target genes and inflammatory factors expression after being submitted to mechanical stretch; preparing gene knockout mice and building vein graft model; observing the effect of ATF3 in animal model. It will provide a new therapy target for vein graft failure.

冠脉搭桥术后静脉桥血管再狭窄发病率高，其发病机制尚不明确且缺少有效干预手段。机械牵张所致桥血管内皮功能失调是关键因素。研究表明转录因子在桥血管再狭窄中起重要作用，可成为新的干预靶点。申请人前期工作中发现活化转录因子3（ATF3）在人再狭窄的静脉桥血管内皮细胞中高表达，生物信息学分析发现ATF3可能通过MAPK信号通路调控桥血管再狭窄。故提出：“ATF3加重血管炎症导致桥血管再狭窄”假说。本项目拟观察患者再狭窄的静脉桥血管ATF3及炎症因子表达；运用CRISPR/Cas9新技术制备ATF3敲除和过表达内皮细胞，观察受机械牵张刺激后细胞功能、靶基因和炎症因子表达变化；制备基因敲除小鼠并复制静脉移植模型，观察ATF3敲除对静脉桥血管再狭窄的影响，进一步验证假说，提供早期干预靶点。

冠状动脉旁路移植术是重症冠心病的主要治疗方法，大隐静脉是目前最常用的桥血管材料，但中远期通畅率较低。因此，阐明静脉桥血管狭窄的分子机制已成为目前冠脉外科中亟需解决的科学问题。本课题通过小鼠下腔静脉移植模型、细胞牵拉模型等方法对转录因子ATF3在桥血管狭窄过程中的调控作用进行研究，发现在敲除ATF3基因明显减轻小鼠移植静脉内膜增生，同时通过测序及生物信息学等方法发现TGF-β是ATF3的下游基因，机械牵张刺激静脉内皮细胞后，转录因子ATF3表达上升，通过TGF-β及MAPK通路引起细胞炎症，导致静脉桥血管狭窄，为理解CABG术后静脉桥血管狭窄的分子机制提供了新的理论依据。