胚胎干细胞(ESCs)是研究发育体系、药物筛选及细胞治疗的理想模型，关于其定向分化为成体细胞的研究有助于向临床应用转化。研究表明表观遗传调控在ESCs的分化中发挥重要的作用。我们前期研究证实两个非编码RNA，miR-29b与lncRNA-Gas5，均能与DNA去甲基酶Tet1相互作用共同调控ESCs向内胚层的分化。生物信息学预测Gas5是miR-29b的潜在靶点，结合文献报道miR29b、Gas5与Tet1在胰岛β细胞中的作用，我们提出本课题的科学假说：miR29b-Gas5-Tet1形成的表观遗传通路共同调控ESCs-内胚层-胰岛β细胞的分化。本课题拟利用CRISPR-Cas9构建所需ESCs，通过体外分化、体内移植、RNA测序等方法阐明miR29b-Gas5-Tet1通路在ESCs-胰岛β细胞分化中的作用及机制。这将为临床上开发基于胰岛β细胞的相关细胞治疗（如糖尿病）提供实验基础。

Embryonic stem cells (ESCs) are ideal model for investigation of developmental system, drug-screening and cell therapy, ESCs-somatic cells differentiation related study contributes to transition of clinical application. Related studies show that epigenetic regulation play an important role in ESCs differentiation. Our previous reports demonstrate that two non-coding RNA, microRNA-29b and lncRNA-Gas5, both regulate ESCs-endoderm differentiation via interacting with DNA demethylase Tet1. Bioinformatics predict that Gas5 is a potential target of miR-29b. By integrating other associated reports about miR-29b, Gas5 and Tet1 in pancreatic β cells, we come up with the hypothesis of this project: the epigenetic regulatory pathway miR-29b-Gas5-Tet1 synergistically modulate differentiation of ESCs-endoderm-pancreatic β cells. By using CRISPR-Cas9 to construct needed ESCs, in vitro differentiation, in vivo transplantation, RNA-seq etc., we try to prove the function and mechanism of miR-29b-Gas5-Tet1 pathway in the differentiation of ESCs-pancreatic β cells, which will provide experimental foundation of development of pancreatic β cells-based cell therapy, such as diabetes, in clinic.