MicroRNA调控小鼠Sca-1+CD31-心脏干细胞分化和干性维持的分子网络及作用研究

Cardiac resident stem/progenitor cells (CSC/CPCs) are critical to the cellular and functional integrity of the heart by maintaining myocardial cell homeostasis. MicroRNAs are important modulators of development, which regulate the self-renewal and differentiate of stem cells, however the precise function of microRNA, especially in different subtypes CSC/CPCs for differentiation and stemness maintenance is unclear. Our previous studies indicated that mouse heart-derived Sca-1+CD31−cells were multipotent, and then analyzed the microRNA and mRNA expression microarray. This project focuses on mouse heart-derived Sca-1+CD31−cells on the basis of previous studies, will be carried out two aspects: 1) integrated analysis of microRNA and mRNA expression microarray by bioinformation combining meta-analysis; to build molecule network of mouse Sca-1+CD31−cells differentiation and stemness maintenance by microRNA regulation；2) to determine the role and pathway of some key differences expression microRNAs(for micro-322 and micro-505-5p) in the regulation of mouse stem cell self-renewal and differentiation by genetic modification techniques (knockdown and overexpression) and cytology methods. The results will not only to clarify the role of microRNA in cardiac resident stem/progenitor cells, and enrich the overall molecular regulatory networks of adult stem cell differentiation and regulation,but for affording the foundation of new theory and technology for treatment of cardiovascular diseases and will greatly enhance our basic biological characteristics for cardiac stem cells.

心脏干细胞在维持心脏自稳态和损伤修复中起关键作用，microRNA参与多种干细胞自我更新和分化的调节，但针对不同亚群心脏干细胞分化和干性维持的作用特性尚不清楚。我们的前期研究表明，小鼠心脏Sca-1+CD31-细胞具有多向分化潜能，并利用基因芯片检测了Sca-1+CD31-细胞的mRNA 和microRNA表达谱。本课题拟在前期研究基础上，1）利用生物信息学对mRNA 和microRNA表达谱数据关联分析，结合meta分析，构建microRNA调控小鼠Sca-1+CD31-心脏干细胞分化和干性维持的分子网络；2）选择关键调控的microRNA如micro-322和micro-505-5p，利用病毒转染及细胞学手段研究其在Sca-1+CD31-细胞分化中的功能以及调控细胞分化的作用途径。这些工作将极大地提升对心脏干细胞基本生物学特性的理解，为发展新的心血管疾病细胞治疗策略提供理论和技术基础。

心脏干细胞在维持心脏自稳态和损伤修复中起关键作用。本课题利用生物信息学对Sca-1+不同亚群心脏干细胞的mRNA 和microRNA表达谱数据关联分析，并从中筛选到miR-322-5p、节律基因Nr1d1可能是Sca-1+心脏干细胞分化调控和干性维持的关键因子；利用病毒转染及细胞学手段，研究miR-322-5p、Nr1d1在Sca-1+细胞分化中的功能以及调控细胞增殖、凋亡、衰老的作用。结果显示，尽管miR322-5P在两类心脏干细胞亚群中的表达水平有显著差异，但miR322-5P仅影响了Sca-1+细胞向血管内皮细胞分化的能力，不是干性维持的关键调控因子；Nr1d1则主要影响细胞的自我更新能力，可与Nr4a3相互作用，靶向调控serpina3的表达，进而调控细胞周期和增殖。这些工作将极大地提升对心脏干细胞基本生物学特性的理解，为心血管疾病的细胞治疗提供理论基础。