候选microRNAs调控泛素蛋白酶体系统影响心肌重构实验研究

Ischemia heart disease represents the primary cause of human morbidity and mortality. Especially those patients who didn't accepted coronary vascular reconstruction display a dynamic myocardium remodeling and deceasing heart function. It is formidable to seek perfect therapeutic strategy for those patients. The pathological process of ischemic heart is myocardium remodling associated with myocardial cell apoptosis and myocardial fibrosis. .The implications of miRNAs in the pathological process of cardiovascular system have recently been recognized. MicroRNAs are endogenous, no encoding small RNA regulating the post- transcription of target gene, which play upstream regulation action in pathogenesis of heart failure. Ubiquitin-proteasome system (UPS) is high expression in impaired myocardium, responsible for the degradation of majority of impaired and olden cellular proteins and playing essential roles in DNA repair. MicroRNA control gene expression in transcriptional and post-transcriptional level and UPS regulate cell apoptosis in protein and translation level. However, without satisfy reply about the relationship between the two important systems up now. . According to our previous work demonstrated that candidate miRNAs (miR-1, miR-133，miR-21，miR-195) expression are disorder and UPS protein(19S proteasome,20s proteasome and E2) are damage in the pathophysiology of ischemia mouse heart. This research will apply antisense oligonucleotide to block and viral vector to over express candidate microRNAs and to explore the probable action and mechanism by which UPS influence myocardium remolding potential regulated by candidate microRNAs..Finally to suggest that candidate miRNAs regulated UPS related mRNA expression, influence UPS related protein synthesis and thereby conducting key regulated action in myocardial cell apoptosis and myocardial fibrosis. In addition, we focus on the development of miRNA antagonists (antagomirs) to target miRNAs, compare the effects of antagomirs and UPS inhibitor to delay the myocardium remodeling and recommend antagomirs may translate into novel therapeutic strategies for ischemia heart disease in the future.

未能血运重建的缺血性心脏病患者进行性心肌重构、心功能下降是棘手的治疗难题，其病理基础主要是心肌细胞凋亡及心肌纤维化。MicroRNs是在转录后水平调控基因表达的细胞内非编码小RNA，在心力衰竭病程进展中起着上游调控的作用。泛素－蛋白酶体系统(Ubiquitin-proteasome system，UPS)在病损心肌中是高表达的，执行清除损伤或陈旧蛋白质, 参与DNA修复等下游调控作用。这两个起始及终末调控系统在进展性心肌重构中的相互作用及可能的影响，目前并无良好回答。此项研究将采用反义寡核苷酸阻断及构建病毒载体过表达等方法调节几种候选miRNAs表达并观察miRNAs通过UPS调控心肌重构的作用及可能机制,最终提出候选miRNAs通过干扰UPS系统相关mRNA而影响其蛋白合成从而影响心肌细胞凋亡、心肌纤维化进程，反义寡核苷酸阻断技术将成为一种新的抑制心肌重构的方法。

本课题的研究内容和目标是候选miRNAs（miR-1, miR-133，miR-21，miR-195）.分子表达变化对心力衰竭心肌重构存在影响，通过干扰UPS系统发挥调控心肌重构的作用。MiRNAs水平的基因调控治疗对心肌细胞的保护作用优于单纯抑制剂的应用,蛋白酶体阻断剂可能无逆向调控候选miRNAs的作用。从而证明基miRNAs的干预治疗成为减少心力衰竭后心肌重构新的治疗思路。经过三年的实验研究,取得了初步的研究成果及进展：1）候选microRNA（miR-1, miR-133，miR-21，miR-195）及UPS中主要组份（26S蛋白酶体中主要活性成分19S蛋白酶体、20S蛋白酶、泛素结合酶E2）在心力衰竭心肌细胞不同时间表达不同与不同的纤维化进程有关。2) miRNA的表达改变（过表达或抑制）可调节泛素蛋白酶体系统，加强或减弱其清除损伤蛋白的作用。3)靶miRNA表达的改变及UPS蛋白酶体阻断剂对心力衰竭心肌纤维化的影响作用不同。 4）研究期间发表SCI论文4篇，2篇正在修改，参加国际会议1次，培养研究生4名。