Epigenetic and chemical approaches to generate function beta cells

描述（由申请人提供）：再生产生胰岛素的β细胞以及胰岛移植是治疗1型糖尿病（T1D）最有前途的长期解决方案。这种方法成功的一个主要障碍是器官供体的短缺和同种异体移植后终身免疫抑制的必要性。最近的两项进展，成功地将体细胞重编程为多能的胚胎干细胞样IPS（诱导多能干细胞）细胞，以及成功地将人类胚胎干细胞分化为功能性胰岛样细胞簇（ILCs），开启了通过将体细胞重编程为IPS细胞，然后进行引导分化，产生患者特异性胰岛素分泌ILCs的可能性。事实上，在一项概念验证研究中，我们最近已经证明，使用这种方法可以从人类皮肤成纤维细胞中产生胰岛素分泌细胞。尽管这一令人鼓舞的结果，几个障碍必须克服之前，该技术的价值可以实现临床。主要障碍包括：1)使用携带病毒载体的iPS细胞的安全性问题；2)现有方法在生成功能性β细胞方面效率较低；3)自体免疫破坏移植的β细胞。鉴于大型iPS细胞群体正在解决第一个问题，许多免疫学实验室正试图解决第三个问题，目前的建议计划使用表观遗传学、化学和ECM方法来解决第二个问题。具体目标是：

DESCRIPTION (provided by applicant): Regeneration of insulin-producing beta-cells as well as islet transplantation is the most promising long-term solutions for Type 1 diabetes (T1D) treatment. A major obstacle to the success of this approach is the shortage of organ donors and the necessity for life-long immunosupression after allograft transplantation. Two recent advances, the success in reprogramming somatic cells into pluripotent ES cell-like IPS (induced pluripotent stem) cells and the success in differentiation of human ES cells into functional islet-like clusters (ILCs), have opened the possibility of generating patient-specific insulin-secreting ILCs through the reprogramming of somatic cells into iPS cells followed by guided differentiation. Indeed, in a proof-of-concept study, we have recently demonstrated that insulin-secreting cells can be generated from human skin fibroblasts using this approach. Despite this encouraging result, several obstacles have to be overcome before the value of this technique can be realized clinically. The major obstacles include: 1) safety concerns over the use of iPS cells that harbor viral vectors; 2) low efficiency of current protocols in generating functional beta-cells; 3) autoimmune destruction of the transplanted beta-cells. Given that the large iPS cell community is attacking the first problem and many immunology labs are trying to solve the third problem, the current proposal plans to use epigenetic, chemical, and ECM approaches to attack the second issue. The Specific Aims are: 1) Characterization of epigenetic features of fetal and mature human beta-cells; 2) Characterization of epigenetic features of definitive endoderm, pancreatic progenitors, and endocrine progenitors; 3) Identification of chemical molecules that promote beta-cell differentiation; 4) Characterization of the effect of extracellular matrix and other environmental factors on beta-cell differentiation; PUBLIC HEALTH RELEVANCE: Beta cell regeneration is a promising longterm solution for diabetes treatment. In this study we propse to use a comprehensive approaches that include epigenetic, chemical, ECM and 3D culture to improve the efficiency of generating functional beta-cells from hES and hiPS cells for the development of a cell replacement therapy for T1D.