Meis2在小鼠心脏内膜垫发育和房室分隔中的作用及其机制研究

Defects of cardiac septation are the most common type of congenital heart disease. The development of endocardial cushion is the key step to form cardiac septum. Myeloid ecotropic viral Integration Site homolog 2 (Meis2) is a typical transcriptional factor containing homobox domain. The effect of Meis2 on heart development is poorly understood. We previously generated Meis2 knockout mouse and found the embryonic lethality in homozygous mice with the defects in endocardial cushion, atrialventricular valve and ventricular septum. This primary data revealed a new role of Meis2 in heart development. To deeply investigate the role of Meis2 in mouse endocardial cushion development and cardiac septation, embryonic heart sections from knockout mice will be serially analyzed by staining. Moreover, to explore the molecular mechanism underlying this function of Meis2 , different approaches such as RNA deep sequence, ChIP－Sequence, CoIP-Mass, and in situ hybridization will be applied to identify key target genes and interacting proteins of Meis2 during this process. We will provide insight into potential targets and novel ideas for diagnosis and prevention of congenital heart disease.

房室分隔缺陷在先天性心脏病发病中占绝对比重，心内膜垫的正常发育是房室分隔形成的关键。同源盒转录因子Meis2在心脏发育中的作用鲜有报道，对其分子机制更是缺乏了解。我们前期成功制备Meis2基因敲除小鼠，首次发现纯合鼠胚胎致死，并伴有心脏内膜垫发育与房室分隔缺陷。本课题将采用组织切片染色、转录组测序、体内ChIP-Seq（染色质免疫共沉淀-测序）、CoIP-Mass（免疫共沉淀-质谱）、原位杂交等手段，从分子、细胞、组织及动物模型多层次明确Meis2在小鼠心内膜垫发育和房室分隔不同阶段的作用以及基因敲除对应的胚胎心脏缺陷；利用敲除鼠胚胎心脏组织体内筛选鉴定这一发育调控作用中Meis2的关键靶基因与相互作用蛋白分子，结合体外验证以及特异性敲除小鼠模型，阐明其作用的分子机制。本研究将为先天性心脏病尤其房室分隔缺陷的诊断治疗提供潜在靶点和新思路。