Restoration of Endocrine Pancreas Function

本计划项目申请（PPA）提出的研究的总体目标是探索利用干细胞/祖细胞和修饰胰岛作为细胞疗法恢复胰腺内分泌功能，从而治愈糖尿病的潜在疗效。这一PPA的动机是几个偶然事件的发生：(1)三位哈佛研究者，Susan Bonner-Weir博士（乔斯林），Joel Habener博士（麻省总医院）和Richard Mulligan博士（儿童医院）独立发现了胰腺干细胞；(2) Douglas Helton博士（哈佛大学）提供的包含胰腺中表达的所有基因的规范化胰腺cDNA阵列；(3) Dennis Sgroi博士（马萨诸塞州总医院）开发了一种制备基因表达谱探针的方法，Bennis Sgroi博士（马萨诸塞州总医院）开发了一种从激光捕获显微解剖获得的微量组织中制备基因表达谱探针的方法；(4) Melissa Thomas博士（马萨诸塞州总医院）在成人胰腺胰岛中发现了活跃的刺猬信号；(5)Gordon Weir博士（Joslin）从先前存在的胰岛移植核心实验室获得了高质量的人类胰岛。该申请提出了三个科学项目和两个科学核心，它们将协同工作以实现目标。项目1：用于β细胞再生的胰腺源性干细胞/祖细胞（PI: Dr. Bonnor-Weir）有三个目标：(1)分析不同的导管源性干细胞/祖细胞群体；(2)人导管源性干细胞与胰岛源性干细胞/祖细胞分化过程中基因表达谱的比较；(3)通过移植干细胞/祖细胞在糖尿病动物模型（大鼠部分胰腺切除术）中再生β细胞。项目2：胰岛移植的调节（PI: Dr. Weir）有三个目标：(1)通过表达谱评估人类胰岛；(2)确定人类胰岛移植后的命运；(3)移植干细胞/祖细胞（NIPs、导管祖细胞、SP细胞等）的分化。项目3：胰岛发育过程中的形态素信号传导（PI: Dr. Thomas）有三个目的：(1)hedgehog信号传导调节同源结构域蛋白IDX-1表达的机制；(2) hedgehog信号在胰腺源性干细胞/祖细胞向β细胞分化中的作用；(3)体内β细胞发育中的刺猬信号传导。两个科学核心是：核心B：胰岛分离和移植（CD: Dr. Weir）和核心C：激光捕获显微解剖和基因表达谱（co -CD: Dr. Weir）。Sgroi和Melton)。这三个项目都将大量使用这两个核心。事实上。这两个核心是项目的核心，没有它们，项目的目标就无法实现。这两个科学核心已经建立起来，并作为哈佛JDRF胰岛移植中心的组成部分运行。此外，本PPA申请的所有参与者都是niddk资助的两个糖尿病内分泌研究中心之一的成员（Joslin和MGH-based）。这项PPA的一个重要方面是，参与者将是第一批在cDNA阵列上分析基因表达的人之一，该阵列包含了胰腺中表达的所有基因，并允许确定健康与患病胰岛中表达的基因差异，以及干细胞/祖细胞5向β细胞分化过程中表达的基因。这份PPA提出了通过再生医学方法治疗糖尿病的初步研究。

The overall objectives of the studies proposed in this Program Project Application (PPA) are to explore the potential efficacies of using stem/progenitor cells and modified pancreatic islets as cellular therapies to restore endocrine pancreas function and to thereby cure diabetes mellitus. The motivation for this PPA is the fortuitous occurrence of several events: (1) the independent discoveries of pancreatic stem cells by three Harvard investigators, Dr. Susan Bonner-Weir (Joslin), Dr. Joel Habener (Massachusetts General Hospital), and Dr. Richard Mulligan (Childrens' Hospital); (2) the availability from Dr. Douglas Helton (Harvard University) of normalized pancreas cDNA arrays that contain all of the genes express in the pancreas; (3) the development by Dr. Dennis Sgroi (Massachusetts General Hospital) of a means to prepare gene expression profiling probes by Dr. Bennis Sgroi (Massachusetts General Hospital) of a means to prepare gene expression profiling probes from minuscule amounts of tissue obtained by laser capture microdissection; (4) the discovery by Dr. Melissa Thomas (Massachusetts General Hospital) of active hedgehog signaling in the islets of the adult pancreas and (5) the availability from Dr. Gordon Weir (Joslin) of high quality human islets from a preexisting islet transplantation core laboratory. The application proposes three scientific projects and two scientific cores that will work synergistically together to achieve the objectives. Project 1: Pancreas-derived stem/progenitor cells for the regeneration of beta cells (PI: Dr. Bonnor-Weir) has three aims: (1) analysis of distinct populations of duct-derived stem/progenitor cells; (2) gene expression profiling comparisons of human duct-derived versus islet derived stem/progenitor cells during their differentiation; (3) regeneration of beta-cells via transplantation of stem/progenitor cells in animal models of diabetes (rat partial pancreatectomy). Project 2: Modulation of pancreatic islets for transplantation (PI: Dr. Weir) has three aims: (1) evaluation of human islets by expression profiling; (2) determination of the fate of human islets after transplantation; (3) differentiation of transplanted stem/progenitor cells (NIPs, ductal progenitors, SP cells, and others. Project 3: Morphogen signaling during pancreatic islet development (PI: Dr. Thomas) has three aims: (1) mechanisms by which hedgehog signaling regulates expression of homeodomain protein IDX-1; (2) role of hedgehog signaling in the differentiation of pancreas-derived stem/progenitor cells into beta-cells; (3) hedgehog signaling in beta-cell development in vivo. The two scientific cores are: Core B: Islet isolation and transplantation (CD: Dr. Weir) and Core C: Laser capture microdissection and gene expression profiling (Co-CDs: Drs. Sgroi and Melton). All three projects will be heavy users of the two cores. In fact. The cores are the heart of the project, without which the objectives of the project could not be accomplished The two scientific cores are already established and running as components of the Harvard JDRF Islet Transplantation Center. In addition, all participants in this PPA application are members of one of the two NIDDK-funded Diabetes Endocrinology Research Centers (Joslin and MGH-based). An important aspect of this PPA is that the participants will be amongst the first to profile gene expression on cDNA arrays that incorporate all of the genes expressed in the pancreas and allow for determinations of the differences in genes expressed in healthy versus diseased islets and the genes expressed during the differentiation of stem/progenitor5 cells into beta-cells. This PPA proposes the initial studies on the way to providing a cure for diabetes via the approaches for regenerative medicine.