LncRNA-uc.167致心脏发育畸形的分子机制研究

uc.167 is a novel long noncoding RNA that conserved in vertebrates and highly expressed in myocardial tissue of fetus with ventricular septal defect identified by lncRNA microarray. Our previous study found overexprssion of uc.167 inhibited cardiac differentiation of P19 cells and cardiac-specific overexpression of uc.167 induced ventricular septal defect phenotype in transgenic mice. Furthermore, bioinformatic analysis and experiments suggested MEF2C was its candidate target. Based on these data, we will analyse the temporal and spatial expression patterns of uc.167 during cardiac differentiation and development, and investigate the function of uc.167 in both p19 cells and cardiac-specific uc.167 transgenic mouse we generated before. In addition, we will explore the detailed mechanism of uc.167 interacted with MEF2C during the development of congenital heart defects. So far there is no report of human lncRNA uc.167 in cardiac development, thus this study have certain creativity and will provide a new potential target for the prevention and treatment of congenital heart disease.

人uc.167是我们采用lncRNA芯片筛选到的、脊椎动物中高度保守的、一条差异高表达于发育异常胚胎心脏组织中、功能未知的lncRNA。前期发现：①过表达uc.167显著抑制P19细胞向心肌细胞分化；②心脏特异过表达uc.167转基因鼠有室缺表型；③生物信息学与实验均提示MEF2C可能为uc.167调控靶标。研究拟分析uc.167在心脏发育中的时空表达规律；采用过表达与敲低策略，明确uc.167对心肌细胞功能的影响；应用已制备成功的心脏特异过表达uc.167转基因鼠，深入探讨uc.167对心脏发育的影响；以MEF2C为机制主线，探讨uc.167与MEF2C的相互作用及调控机制，以论证uc.167异常高表达通过调控MEF2C致心脏发育异常的新机制。研究有源头创新性，将揭示uc.167在心脏发育中的作用与机制，并为先心病防治提供潜在的干预靶标。

uc.167是我们通过芯片筛选得到的一条在不同物种间高度保守、且高表达于人发育异常胚胎心脏中的lncRNA。本项目在前期发现过表达uc.167显著抑制P19细胞向心肌细胞分化，生物信息学与实验均提示Mef2c可能为uc.167调控靶标。因此，以Mef2c为主线，深入探讨uc.167在胚胎心脏发育中的作用及致畸的可能机制。通过本课题的研究，我们发现①过表达LncRNA-uc.167可抑制细胞的增殖、促进细胞凋亡、显著抑制P19细胞向心肌细胞方向的分化；②Mef2c与uc.167共同过表达可挽救uc.167对P19细胞造成的不利影响，LncRNA-uc.167通过负向调控其邻近基因Mef2c发挥生物学功能；③uc.167过表达虽可产生明显的细胞表型，但uc.167转基因小鼠并未出现明显的心脏发育畸形，提示uc.167在心脏发育过程中可能具有一定的“微调节”作用，但可能不是唯一关键性的因素。