GROWTH VERSUS DIFFERENTIATION IN HUMAN BETA CELLS

缺乏表现出葡萄糖响应性的胰腺β细胞 胰岛素分泌一直是广泛发展的主要障碍， 适用于糖尿病的细胞移植疗法。 为了解决这个 前体 这将提供大量的细胞， 体外，其保留葡萄糖响应性胰岛素分泌或 来区分和获得这种属性。 这样的细胞可以用于 细胞移植治疗糖尿病 人β细胞和内分泌细胞前体的扩增群体 可以通过两种不同的方法在体外培养。一是 使原代细胞在细胞外基质（ECM）上生长， 肝细胞生长因子/分散因子（HGF/SF）。 二是 在细胞中表达显性癌基因，导致基质和生长 体外非依赖因子生长。 然而，在生长刺激下， 无论哪种方法，细胞都失去了分化功能， 胰岛素基因表达。 这并不奇怪，因为相反的 存在于许多细胞中生长和分化之间的关系 包括内分泌胰腺。有趣的是， 分化功能的变化非常相似，无论 生长是否受到致癌基因或生长因子的刺激， 细胞外基质 我们假设有共同的信号 我们体内的致癌基因激活了 用于制造人类β细胞在培养中分裂。 而且我们 假设这些通路会聚作用于转录， 决定β细胞中基因表达模式的因素， 尤其是那些在胰岛素基因表达中起作用的基因。 因此，本建议的重点是确定 表达，并使用逆转录病毒载体在体外表达这些因子。 一系列人胰腺内分泌细胞系和扩增群体 人类原代β细胞

The shortage of pancreatic Beta-cells exhibiting glucose-responsive insulin secretion has been a major obstacle to the development of widely applicable cell transplantation therapies for diabetes. To address this precursors. This would provide a large quantity of cells, grown in vitro, that retain glucose-responsive insulin secretion or the ability to differentiate and acquire this property. Such cells then be used for cell transplantation therapies for diabetes. Expanded populations of human Beta-cells and endocrine cell precursors can be grown in vitro using two distinct approaches. The first is to grow primary cells on extracellular matrix (ECM) in the presence of hepatocyte growth factor/scatter factor (HGF/SF). The second is to express dominant oncogenes in the cells, resulting in matrix and growth factor independent growth in vitro. However, upon growth stimulation by either method, the cells lose differentiated function, particularly insulin gene expression. This is not surprising given the inverse relationship between growth and differentiation that exists in many cell types, including the endocrine pancreas. Interestingly, the pattern of changes in differentiated function is very similar, regardless of whether growth is stimulated with oncogenes or with growth factor and extracellular matrix. We hypothesize that there are common signal transduction pathways that are activated by the oncogenes that we have used to create human Beta-cells to divide in culture. Furthermore, we hypothesize that these pathways converge to act on the transcription factors that determine the pattern of gene expression in Beta-cells, especially those that play a role in insulin gene expression. Therefore, the focus of this proposal is to determine the pattern of expression and to use retroviral vectors to express those factors in a series of human pancreatic endocrine cell lines and expanded populations of primary human Beta-cells.