FOXO4调控NEAT1转录介导冠状动脉慢血流左心室心肌血流灌注的作用机制研究

Decrease of left ventricular myocardial perfusion was established in coronary slow flow (CSF), however, the underlying mechanisms remain obscure. Our previous study had demonstrated that serum ICAM-1 increased and negatively correlated with left ventricular myocardial perfusion in patients with CSF. Further, we found via bioinformatics prediction and identification in endothelial cell models that ICAM-1 expression was inhibited by binding between NEAT1 and miR-299-3p; binding between FOXO4 and the promoter region of NEAT1 increased activity of NEAT1. Therefore, we hypothesized that high expression of FOXO4 in CSF vascular endothelial cells induced NEAT1 transcription, and NEAT1 binding to miR-299-3p by sponge adsorption resulted in decrease of myocardial perfusion through weakening the downregulation of miR-299-3p to its target gene ICAM-1 and thereby upregulating the ICAM-1 expression, which contributed to the development of CSF. Combining in vitro and in vivo approach, the current study aims to investigate the mechanisms of affecting the downregulation of miR-299-3p to its target gene ICAM-1 via FOXO4 regulating NEAT1 transcription and the target binding between NEAT1 and miR-299-3p, and to finally determine the mechanisms of FOXO4 regulating transcription of NEAT1 to affect left ventricular myocardial perfusion in CSF. Our findings will provide CSF diagnosis and treatment novel insights into both biomarkers and targets.

冠状动脉慢血流(CSF)可导致左心室心肌血流灌注减低，但机制不清。前期发现CSF患者血清ICAM-1增高，与左心室心肌血流灌注负相关。生信预测并在内皮细胞模型中验证NEAT1可与miR-299-3p结合，靶向抑制ICAM-1表达；FOXO4可与NEAT1启动子区结合并增加其活性。建立假说：CSF血管内皮细胞中高表达的FOXO4促进NEAT1转录，NEAT1通过海绵吸附作用结合miR-299-3p，减弱miR-299-3p对靶基因ICAM-1负性调控作用，从而上调ICAM-1表达，进而减低心肌血流灌注，参与CSF发生发展。本项目结合体内外实验，研究FOXO4调控NEAT1转录，NEAT1与miR-299-3p结合，影响miR-299-3p负性调控ICAM-1的机制；进而明确FOXO4调控NEAT1转录介导CSF左心室心肌血流灌注的作用机制。研究结果将为CSF诊治提供新的生物学标志物和新靶标。

冠状动脉慢血流 (CSF) 是指在排除继发因素后，冠状动脉造影显示冠状动脉无明显狭窄，但末端充盈延迟的现象。负责人前期发现CSF患者左心室心肌灌注减低，然而CSF心肌灌注减低的机制尚不明确。.研究首先构建FOXO4与NEAT1过表达与表达沉默的细胞模型，研究转录因子FOXO4调控NEAT1的转录，进而影响血管内皮细胞ICAM-1表达的机制；构建NEAT1与miR-299-3p过表达与表达沉默的细胞模型，研究NEAT1与miR-299-3p结合，进而影响血管内皮细胞ICAM-1表达的机制；构建miR-299-3p与ICAM-1过表达与表达沉默的细胞模型，研究miR-299-3p与ICAM-1靶向结合，进而影响血管内皮细胞ICAM-1表达的机制；检测CSF患者及对照者血清中NEAT1、miR-299-3p的表达以及ICAM-1的含量，采用心肌声学造影评估左心室心肌血流灌注，明确CSF患者血清中NEAT1、miR-299-3p和ICAM-1含量与左心室心肌血流灌注和冠状动脉血流cTFC的相关性。.研究结果表明，CSF血管内皮细胞中高表达的FOXO4促进了NEAT1的转录，NEAT1可通过海绵吸附作用结合miR-299-3p，从而减弱了miR-299-3p对靶基因ICAM-1的负向调控作用，上调ICAM-1的表达，进而影响了左心室心肌血流灌注，参与CSF的发生发展。且NEAT1、miR-299-3p及ICAM-1可作为诊断CSF的血清生物学标志物。.本研究以CSF患者心肌灌注减低为切入点，从非编码RNA为核心的调控网络，深入研究心肌灌注减低的分子机制，揭示了CSF发病新机制。同时明确了FOXO4、NEAT1、miR-299-3p及ICAM-1分子可作为诊断CSF的生物学标志物。研究结果为阐明CSF心肌血流灌注减低的机制提供了新思路，为寻找治疗靶点及改善心肌血流灌注提供了新方向，同时为诊断CSF提供了血清生物学标志物，对于CSF的诊治具有重要的临床价值，已发表论文10篇，其中SCI论文9篇。