Mechanisms of cell regeneration in the pancreas

描述(由申请人提供)：这项建议的总体目标是鉴定和鉴定成人胰腺中可能的干细胞/祖细胞。这类细胞的鉴定将有助于开发糖尿病患者的细胞替代疗法。这种疗法虽然非常有效，但目前受到身体组织可移植胰岛短缺的限制。成体祖细胞将是替代的产生胰岛素的β细胞分化的一个特别有吸引力的来源，因为它们可能从患者自己的胰腺中分离出来，从而避免与异体组织移植相关的免疫反应。然而，在胚胎时期之后，干细胞或祖细胞群体是否存在于胰腺中仍不清楚。在初步研究中，我们已经确定转录因子SOX9是胚胎胰腺中祖细胞的标志，并发现SOX9对它们的扩增和维持是必不可少的。值得注意的是，它仅在成人胰腺中的一部分导管细胞中持续表达，这种细胞类型被认为是胰腺干/祖细胞的潜在储存库。鉴于SOX9在维持未分化的、多能的胚胎胰腺祖细胞方面的关键作用，我们假设该因子也标记和维持成人胰腺中的干细胞隔室。实验的目的是测试SOX9是否在胰腺再生中发挥作用，以及成年胰腺中SOX9标记的细胞是否可以作为多能的胰腺祖细胞发挥作用。利用可诱导基因消融，目的1是确定Sox9在整个发育和成年期胰腺细胞分化和维持中的作用。目的2研究胰腺部分切除或STZ治疗后胰腺再生是否需要Sox9。目的3将确定表达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图谱和在细胞移植实验中跟踪它们的命运来进行测试。

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.