Growth Versus Differentiation in Human Beta Cells

描述（由申请人提供）：了解成熟内分泌细胞由内分泌前体发育的机制非常重要，因为它可以为糖尿病的细胞移植治疗提供无限的β细胞来源。糖尿病研究的一个目标是从人类内分泌胰腺中培养细胞系，这些细胞系可以无限量生长，并诱导其沿β细胞谱系分化，从而产生葡萄糖反应性胰岛素分泌。在过去的资助期内，在开发delta或beta细胞系方面取得了成功。这个建议的重点是探索谱系承诺的本质。人类胰腺内分泌细胞系分化为δ或β细胞系。该建议的中心假设是细胞系的不同谱系承诺反映了参与成熟内分泌细胞建立和维持的转录因子表达的差异。

DESCRIPTION (provided by applicant): Understanding the mechanism by which mature endocrine cells develop from endocrine precursors is of great importance as it could lead to the development of an unlimited source of beta cells for cell transplantation therapies for diabetes. A goal of diabetes research has been to develop cell lines from the human endocrine pancreas that can be grown in unlimited quantities and induced to differentiate along the beta cell lineage resulting in glucose-responsive insulin secretion. During the past funding period, success was achieved in developing cell lines that are committed to either the delta or beta cell lineages. This proposal is focused on exploring the nature of that lineage commitment. of human pancreatic endocrine cell lines to either the delta or beta cell lineages. The central hypothesis of this proposal is that the differential lineage commitment of the cell lines reflects differences in the expression of transcription factors that are involved in the establishment and maintenance of mature endocrine cells. Initially, the mechanism by which the bHLH transcription factor NeuroD1 acts to repress somatostatin promoter activity in a delta cell line, resulting in a partial switch to the beta cell lineage, will be studied. Other transcription factors that have been identified as candidates for being involved in delta versus beta cell lineage commitment will be studied using retroviral vector-mediated gene transfer into human pancreatic endocrine cell lines. Genes that are differentially expressed in delta versus beta cell lines and that are downstream of transcription factors that are important in b-cell development will be ascertained using DNA microarray technology. Finally, a genetic screen will be undertaken to isolate genes that upregulate insulin promoter activity.