miR503和/或miR135a靶向Zfp217调控间充质干细胞成脂定向的机制研究

间充质干细胞向前脂肪细胞定向由高度复杂协调的调控网络控制，早期转录因子具有关键作用。本团队前期鉴定出锌指蛋白Zfp217是一个新的干细胞成脂定向的早期关键转录因子，是miR503和miR135a的靶基因，但调控机制不明。项目提出Zfp217是成脂定向的关键调控因子之一，受miR503和/或miR135a调控，从而影响成脂定向的假设。拟开展4个研究：表达模式及功能获得/缺失研究证实Zfp217在成脂定向中的作用，基因芯片筛选受其调控的下游基因；用转染miRNA类似物或抑制物及荧光素酶等研究miR135a和/或miR503在成脂定向中的作用及对Zfp217的调控；构建Zfp217敲除小鼠及活体注射miRNA类似物或抑制物后研究对脂肪组织发育及MEFs成脂定向的作用机制。本研究将进一步完善miRNA和早期转录因子调控脂肪细胞生成的调控网络，阐明猪脂肪组织形成机制，为降低猪体脂沉积提供选育的靶标。

Commitment of pluripotent stem cell into preadipocytes is regulated by a complex and highly coordinated network,and lineage-specific transcription factors might play as the key regulators. By using RNA-Seq and siRNA scanning, we previously obtained a candidate transcription factor zinc finger protein 217 (Zfp217), which might play as a key regulator in adipose commitment, is a direct target gene of miR503 and miR135a. In the proposed study, we hypothesize that Zfp217 is one of the key regulator in adipogenesis, and expression of Zfp217 is regulated by miR-135a and miR-503. To test this hypothesis,we will firstly evaluate effect of overexpression and knockdown of Zfp217 on adipose commitment in mesenchymal stem cell (C3H10T1/2) and preadipocytes (3T3L1),and identify target genes of Zfp217 using microarray. Then by using miR-mimics or anti-miRNAs and luc-reporter system, the effect of miR-135a and miR-503 on adipose commitment and Zfp217 expression will be evaluate. Additionally, miRNA-mimics or anti-miRNAs will be injected to wild type or Zfp217 knockout mouse to assay effect of miRNAs and Zfp217 on development of adipose tissue in vivo and adipose commitment in mouse embryo Fibroblast (MEFs). The present study is of significant importance to improve transcriptional regulatory networks of adipose commitment,further reveal osteoporosis and obesity-related diseases,improve production performance of farm animals.