多能性相关lncRNA Osclr8调控细胞重编程的机制研究

细胞重编程机理不清、效率低、耗时，是诱导多能干细胞（iPS）至今未能用于临床治疗的最大路障。近期研究提示lncRNA在决定干细胞命运中起到关键作用,但在重编程中lncRNA如何与多能基因互作，如何调控干细胞多能性，能否促进iPS细胞诱导，这些研究尚属空白。 .本课题组发现一条命名为Osclr8的全新lncRNA，在重编程中呈差异表达并能结合到多能基因启动子上，参与染色质内环结构形成；若将其敲除，干细胞将走向分化。提示该lncRNA与干细胞命运决定关系密切。.本研究拟采用人工诱导DNA成环、RNA逆转录结合捕获测序、染色质构象捕获、体内重编程等技术，研究Osclr8 如何通过招募转录因子、参与多元高级转录复合结构形成、促进细胞重编程，并最终通过操纵以lncRNA为媒介的转录复合结构，达到提高干细胞诱导效率的目的。本研究将为诱导细胞重编程开辟新方向，对促进iPS产品临床应用具有重要意义。

The terminally differentiated-somatic cells can be reprogrammed into “induced pluripotent stem” (iPS) cells. The technology has been honored with the 2012 Nobel Prize for its breakthrough discovery in stem cell research. Nonetheless, this reprogramming process is extremely inefficient and time consuming, thus significantly impeding its highly anticipated clinical application. Recent studies suggest that long noncoding RNAs (lncRNAs) may play a key role in determining the fate of stem cells. However, whether lncRNAs are able to overcome epigenetic bottleneck to promote pluripotency remains poorly defined..In studying the mechanism underlying cell reprogramming, we have recently identified Osclr8, a novel lncRNA that interacts with the promoters of multiple pluripotency-associated genes. Knockdown of Osclr8 causes loss of intrachromosomal looping and induces the exit of iPS cells from pluripotency. In the present study, we propose to utilize several technologies established in our lab to explore the role and mechanisms of this lncRNA in cell reprogramming, including “Cas9-induced chromosomal looping”, “RNA in situ reverse transcription-associated trap sequencing” (RAT-Seq), “chromosome conformation capture” (3C), “RNA-guided chromosome conformation capture” (R3C), and “chromosomal loop screening” approaches. We will examine how this lncRNA controls pluripotency by orchestrating intrachromosomal looping and altering epigenetic modifications. Finally, we will test if Osclr8 is able to promote cell reprograming. ..The overall objective of this study is aimed to revolutionize the existing approaches to robustly induce iPS reprograming for regenerative medicine.