Phenotypic Analysis of Young and Old Beta Cells

描述(由申请人提供)：我们的假设是，新的和成熟的a细胞之间存在明显的表型差异，这将提供关于β细胞出生和死亡的重要信息。使用激光捕获显微解剖和Affymetrix GeneChips，生成基因图谱数据，比较相同大鼠部分胰腺切除(PX)后新的和成熟的胰岛和假手术动物的胰岛的β细胞丰富核心。成熟和假胰岛的比较反映了环境的变化，但新的和成熟的胰岛之间的比较反映了年龄差异。这些数据表明，β细胞的年龄对差异基因表达有明显的影响。第一个目标是开发可用于从早期阶段确定β细胞成熟度的标记，就像a细胞从前体/干细胞分化为成熟的功能性a细胞一样。一些这样的标记已经通过RT-PCR和免疫染色在再生的胰腺和新生胰岛中得到确认，其中所有的a细胞都必须是新的。然后，这些标记将被用于第二个目标，以确定新的和成熟的β细胞在不同年龄动物中的分布，这将回答关于细胞生活史的基本问题。在第三个目标中，这些标记将被用来分离新的和成熟的a细胞，以获得相对纯净的群体，用于分析它们在体外和移植后的体内功能。通过对这些纯种群的基因图谱分析，将确定β细胞在其生活史的不同阶段的遗传“指纹”；这些指纹将对评估干细胞来源的胰岛素产生细胞的成熟度以及在我们未来识别在出生后形成细胞的前体/干细胞方面有价值。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.