Phenotypic Analysis of Young and Old Beta Cells

描述（由申请人提供）：我们的假设是新细胞和成熟细胞之间存在明显的表型差异，这将提供有关β细胞出生和死亡的重要信息。利用激光捕获显微解剖技术和Affymetrix基因芯片，对同一只大鼠部分胰腺切除术（Px）后的新胰岛和成熟胰岛与假手术动物的胰岛的富含β细胞的核心进行了基因分析数据的比较。成熟与假胰岛的比较反映了环境的变化，而新生与成熟胰岛的比较反映了年龄的差异。这些数据显示了细胞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确定β细胞成熟度的标记物，就像细胞从前体细胞/干细胞分化到成熟的功能细胞一样。在再生的胰腺和新生儿胰岛中，已经有几个这样的标记物被RT-PCR和免疫染色所证实，其中所有的细胞都必须是新的。然后，这些标记将用于第二个目标，以确定不同年龄动物中新生和成熟β细胞的分布，这将回答有关细胞生活史的基本问题。在第三个目标中，这些标记将用于分离新细胞和成熟细胞，以提供相对纯净的群体，以便在移植后分析它们在体外和体内的功能。有了这些纯种群的基因图谱，细胞在其生命历程中不同阶段的基因“指纹”将被确定；这些指纹对于评估干细胞衍生的胰岛素生成细胞的成熟度以及我们未来鉴定出生后产生细胞的前体/干细胞具有重要价值。这项研究的另一个重要成果应该是关于诸如什么将导致成功的长期胰岛移植等实际问题的有价值的信息。

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.