Phenotypic Analysis of Young and Old Beta Cells

描述（由申请人提供）：我们的假设是，在新的和成熟的a细胞之间存在可证明的表型差异，这将提供关于β细胞出生和死亡的重要信息。使用激光捕获显微切割和Affyssin基因芯片，产生基因谱数据，比较部分胰腺切除术（Px）后来自相同大鼠的新的和成熟的胰岛的富含β细胞的核心和来自假手术动物的胰岛。成熟胰岛与假胰岛的比较反映了环境的变化，但新胰岛与成熟胰岛之间的比较反映了年龄差异。这些数据显示β细胞的年龄对差异基因表达的明显影响。第一个目标是开发可用于从早期阶段确定β细胞成熟的标记物，就像α细胞已经从前体/干细胞分化为成熟的功能性α细胞一样。几个这样的标记已经通过RT-PCR和免疫染色在再生胰腺以及新生胰岛中得到证实，其中所有的a细胞必须是新的。然后，这些标记物将用于第二个目标，以确定不同年龄动物中新的和成熟的β细胞的分布，这应该回答有关细胞生命史的基本问题。在第三个目标中，这些标记物将用于分离新的和成熟的α细胞，以得到相对纯的群体，用于分析它们在移植后的体外和体内功能。通过这些纯群体的基因分析，将确定β细胞在其生命史中不同阶段的遗传“指纹”;这些指纹对于评估干细胞衍生的胰岛素产生细胞的成熟度以及我们将来鉴定出生后产生细胞的前体/干细胞将是有价值的。这项研究的另一个重要成果应该是有价值的信息，这些实际问题是什么将导致成功的长期胰岛移植。

DESCRIPTION (provided by applicant): Our hypothesis is that there are demonstrable phenotypic differences between new and mature a cells that will provide important information about beta cell birth and death. Using laser capture microdissection and Affymetrix GeneChips, gene profiling data was generated comparing the beta cell-enriched cores of new and mature islets from the same rats after partial pancreatectomy (Px) and of islets from sham operated animals. The comparison of mature vs. sham islets reflects changes in environment but that between new vs. mature islets reflect age differences. These data show clear effects of age of beta cells on differential gene expression. The first aim is to develop markers that can be used for determining beta cell maturity from early stages just as the a cell has differentiated from precursor/stem cells to mature functional a cells. Several such markers have already been confirmed by RT-PCR and immunostaining within the regenerating pancreas as well as with neonatal islets, in which all a cells must be new. These markers will then be used in the second aim to determine the distribution of new and mature beta cells in different aged animals, which should answer fundamental questions about a cell life history. In the third aim these markers will be used to separate new and mature a cells to give relatively pure populations for analysis of their function both in vitro and in vivo following transplantation. With gene profiling of these pure populations the genetic "fingerprints" of the different stages of the beta cell through its life history will be determined; these fingerprints will be valuable for assessing the maturity of stem cell-derived insulin producing cells and in our future identification of the precursor/stem cells that give rise to a cells after birth. Another important outcome of this research should be valuable information about such practical questions as what will lead to successful long-term islet transplantation.