GROWTH VERSUS DIFFERENTIATION IN HUMAN BETA CELLS

表现为葡萄糖反应性的胰岛β细胞缺乏 胰岛素分泌一直是广泛性糖尿病发展的主要障碍。 适用于糖尿病的细胞移植疗法。要解决这个问题 先驱物。这将提供大量的细胞，在 在体外，保持对葡萄糖反应的胰岛素分泌或能力 来区分和获得这一财产。这样的电池然后被用来 糖尿病的细胞移植疗法。 人β细胞和内分泌细胞前体细胞的扩增群体 可以使用两种不同的方法在体外培养。第一个是 在细胞外基质(ECM)上培养原代细胞 肝细胞生长因子/分散因子(HGF/SF)。第二个是 在细胞中表达显性癌基因，导致基质和生长 因子非依赖性体外生长。然而，在刺激增长的情况下 无论采用哪种方法，细胞都会失去分化功能，尤其是 胰岛素基因的表达。考虑到相反的情况，这并不令人惊讶 存在于许多细胞中的生长和分化的关系 类型，包括内分泌胰腺。有趣的是，这种模式 分化功能的变化非常相似，不考虑 无论生长是由癌基因还是生长因子刺激的 细胞外基质。我们假设有共同的信号 由我们拥有的癌基因激活的转导通路 用来创造人类贝塔细胞在培养中分裂。此外，我们 假设这些途径会聚在一起作用于转录 决定贝塔细胞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，这项建议的重点是确定 并利用逆转录病毒载体表达这些因子。 人胰腺内分泌细胞系系列及扩增群体 原代人类贝塔细胞。

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.