组蛋白去甲基化酶JMJD3在维生素C作用下促进体细胞重编程的分子机理研究

Somatic cell reprogramming is a big breakthrough in the field of life science and medicine. To date, the molecular mechanism of somatic cell reprogramming is still poorly understood. Studying the molecular mechanism of somatic cell reprogramming would greatly promote the development of clinical and regenerative medicine. In our previous study, we found Vitamin C could enhance both human and mouse induced pluripotent cells (iPSCs) generation. Most recently, we found a histone H3K27me2/3 demethylase JMJD3 could further enhance reprogramming efficiency under Vitamin C condition. By using point mutation strategy, we found JMJD3 enhance reprogramming efficiency in a H3K27me2/3 demethylase dependent manner. Further, we found that overexpression of JMJD3 could promote mesenchymal to epithelial transition (MET) at early stage and upregulate the expression of pluripotent genes at middle-late stage. In order to study the molecular mechanism of JMJD3 in Vitamin C mediated reprogramming, we first aim to analyze the H3K27me2/3 modification level within promoters of MET and pluripotent related genes. Secondly, we aim to isolate JMJD3 functional protein complex during reprogramming by using tandem purification combined with LC-MS/MS. Then, we will use techniques of genetics, molecular and biochemical biology to dissect the role of JMJD3 and its interacting proteins in Vitamin C mediated somatic cell reprogramming. This study would help us to understand the molecular mechanism of somatic cell reprogramming.

体细胞重编程技术的出现是生命科学和医学领域的一项重大突破，但目前人们对体细胞重编程机理的认识尚不清楚，对体细胞重编程机理的研究将会在很大程度上促进该技术的临床应用和再生医学的发展。我们最近发现组蛋白去甲基化酶JMJD3在维生素C作用下显著提高重编程效率，且是H3K27me2/3组蛋白去甲基化酶依赖性的。进一步研究发现在维生素C存在条件下，过表达JMJD3能够促进重编程早期MET的发生及促进中晚期多能性基因的上调表达。为探索JMJD3促进体细胞重编程的机理，我们拟首先利用ChIP检测MET及多能性相关基因启动子区的H3K27me2/3水平，其次利用体内蛋白复合物纯化与LC-MS/MS技术相结合分离并鉴定体内JMJD3功能复合物的成员组成，接下来将利用分子、生化及遗传等手段来解析JMJD3及其互作蛋白在维生素C作用下促进体细胞重编程的分子机理。本研究将会增进人们对体细胞重编程发生机理的认识。