Mechanisms of cell regeneration in the pancreas

描述（由申请人提供）：本提案的总体目标是鉴定和表征成人胰腺中假定的干细胞/祖细胞。这些细胞的鉴定将促进糖尿病患者细胞替代疗法的发展。这种疗法虽然非常有效，但目前由于缺乏可从尸体组织中移植的胰岛而受到限制。成人祖细胞将是一个特别有吸引力的替代胰岛素生产β细胞分化来源，因为它们可能从患者自身的胰腺中分离出来，从而避免与外来组织移植相关的免疫反应。然而，目前尚不清楚胚胎期以后胰腺中是否存在干细胞或祖细胞群。在初步研究中，我们已经确定了转录因子SOX9作为胚胎胰腺祖细胞的标记物，并发现SOX9对胚胎胰腺祖细胞的扩增和维持至关重要。引人注目的是，它在成人胰腺中仅在导管细胞亚群中持续表达；一种被认为是胰腺干细胞/祖细胞潜在储存库的细胞类型。鉴于SOX9在维持胚胎胰腺未分化的多能祖细胞方面的关键作用，我们假设该因子也标记并维持成人胰腺中的干细胞区室。我们提出实验来验证SOX9是否在胰腺再生中发挥作用，以及成人胰腺中SOX9标记的细胞是否具有多能胰腺祖细胞的功能。使用诱导基因消融，目的1是确定Sox9在发育和成年期间胰腺细胞分化和维持中的作用。目的2检查部分胰腺切除术或STZ治疗后胰腺再生是否需要Sox9。Aim 3将定义表达sox9的细胞是否具有多潜能干细胞/祖细胞的特征和特性。这将通过分离细胞的转录谱分析和在细胞移植实验中追踪它们的命运来检验。

DESCRIPTION (provided by applicant): The overall objective of this proposal is to identify and characterize putative stem/progenitor cells in the adult pancreas. The identification of such cells would facilitate the development of a cell replacement therapy for patients with diabetes. Such therapy, though highly effective, is currently limited by the shortage of transplantable islets from cadaver tissue. Adult progenitors would be a particularly attractive source for the differentiation of replacement insulin-producing beta-cells, as they could possibly be isolated from the patient's own pancreas, thereby avoiding the immune response associated with the transplantation of foreign tissue. It is, however, still unclear whether a stem or progenitor cell population resides in the pancreas beyond the embryonic period. In preliminary studies, we have identified the transcription factor SOX9 as a marker for progenitor cells in the embryonic pancreas and found that Sox9 is essential for their expansion and maintenance. Strikingly, its expression persists in the adult pancreas exclusively in a subset of ductal cells; a cell type that is regarded as a potential reservoir of pancreatic stem/progenitor cells. Given the crucial role of SOX9 in maintaining undifferentiated, pluripotent progenitors of the embryonic pancreas, we hypothesize that this factor also marks and maintains a stem cell compartment in the adult pancreas. Experiments are proposed to test whether SOX9 plays a role in pancreas regeneration and whether the cells marked by SOX9 in adult pancreas can function as pluripotent pancreas progenitor cells. Using inducible gene ablation, Aim 1 is to define the role of Sox9 in pancreatic cell differentiation and maintenance throughout development and adulthood. Aim 2 examines if Sox9 is required for pancreas regeneration after partial pancreatectomy or STZ treatment. Aim 3 will define whether Sox9-expressing cells have characteristics and properties of multipotential stem/progenitor cells. This will be tested by transcriptional profiling of isolated cells and by tracking their fate in cell transplantation experiments.