申请者前期发现核仁素是一可能的心肌内源性保护蛋白，并从核仁素能与含核仁素结合元件的rRNA相结合的事实出发，提出核仁素也能与含有该元件的mRNA相结合从而从转录后水平调节某些心肌保护性基因表达并发挥心肌保护作用的假设，通过制备心肌中过表达核仁素的转基因小鼠和采用cDNA芯片已筛选到多个可能与核仁素结合的心肌保护性基因mRNA。在此基础上，拟采用上述核仁素转基因小鼠、核仁素过表达或RNA干扰的心肌细胞，分别制备心肌缺血-再灌注损伤和心肌细胞缺氧-再给氧损伤模型，深入探讨核仁素的心肌保护作用，采用生物信息学技术、RNA-EMSA、蛋白质-RNA免疫共沉淀、mRNA稳定性分析、荧光素酶报告基因等技术探讨核仁素与3-5个心肌保护性基因的相互作用，从转录后水平深入揭示其对这些基因的调控机制，从多个水平阐明核仁素的心肌保护机制。可望发现新的心肌保护分子和信号通路，为心肌损伤保护开辟新的研究领域。

In previous studies, the applicant found that nucleolin is a possible endogenous myocardial protective protein, and according to the fact that nucleolin could bind with rRNAs containing nucleolin-binding element, hypothesized that nucleolin could also bind with mRNAs containing nucleolin-binding element and regulate post-transcriptionally the expression of some myocardial protective genes and play roles in myocardial protection. By preparation of transgenic mice which specifically over-express nucleolin in myocardium and using cDNA array, the applicant identified some mRNAs of myocardial protective genes which might be bound with nucleolin. Based on these findings, the applicant is going to prepare an animal model of myocardial ischemia-reperfusion injury by using the above transgenic mice, and prepare a cell model of hypoxia-reoxygenation injury in cardiomyocytes with nucleolin over-expression or RNA interference (RNAi), and deeply explore the myocardial protective effects of nucleolin, and clarify the interaction of 3-5 myocardial protective genes and nucleolin by using bioinformatics technique, RNA-EMSA, protein-RNA immuno-precipitation, analysis of mRNA stability, luciferase reporter assay, and clarify the mechanisms by which nucleolin regulates these gene expression at post-transcriptional level and the mechanisms for myocardial protection by nucleolin. It was expected that the progress of this project might promote the discovery of some new myocardial protective molecules and signaling pathways, and open new avenues for the studies on myocardial protection.