mTert-GFP and Pancreatic Progenitor Cells

mTert-GFP 和胰腺祖细胞

• 批准号: 7425982
• 负责人: David T Breault
• 金额: $ 20.7万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7425982
• 关键词: Acinar Cell; Adult; Animals; Autoimmune Process; Beta Cell; Biological Models; Bone Marrow; Cells; Condition; Cultured Cells; Development; Diabetes Mellitus; Disease; Ductal; Event; Future; Germ Cells; Goals; Green Fluorescent Proteins; Healthcare Systems; Hematopoietic stem cells; Histocytochemistry; Human; Immunohistochemistry; In Vitro; Injection of therapeutic agent; Insulin; Insulin-Dependent Diabetes Mellitus; Intestines; Islet Cell; Islets of Langerhans; Label; Localized; Methods; Modeling; Mus; Natural regeneration; Pancreas; Pancreatectomy; Patients; Phenotype; Physiological; Population; Production; Regenerative Medicine; Source; Stem cells; Stimulus; Structure; Structure of beta Cell of islet; Telomerase; Testis; Tissues; Transgenic Mice; Transgenic Organisms; Transplantation; Wound Healing; adult stem cell; blastocyst; crypt cell; design; exenatide; in vivo Model; innovation; intestinal crypt; islet; male; mouse model; novel; progenitor; response; validation studies

DESCRIPTION (provided by applicant): Adult stem cells hold great promise for regenerative medicine, tissue repair and for the study of early developmental events. The identification of new sources of insulin-producing cells would potentially give rise to novel treatment options for patients suffering from diabetes in all its forms. In response to partial pancreatectomy or physiologic stimuli, pancreatic ¿ cells can regenerate by replication of existing ¿ cells and by ¿ cell neogenesis. Pancreatic progenitor/stem cells (PPSC) have been postulated to be the cellular origin of neogenesis, though their existence remains controversial. We hypothesize (1) that a population of PPSC exists, which express telomerase (mTert) as a marker of their stem cell phenotype, (2) that PPSC can be isolated and expanded using mTert-GFP transgenic mice and (3) that with transplantation their differentiation will recapitulate normal islet cell development. We have used an innovative method to generate transgenic mice with endogenous stem cells labeled with GFP. We currently have two independent mTert-GFP transgenic mouse lines, from which GFP+ cells are being evaluated for their stem cell potential. Validation studies in bone marrow and testis have demonstrated GFP expression within two adult stem cell populations: hematopoietic stem cells and male germ cells. In addition, this model has allowed for the identification and isolation of a putative intestinal stem cell population, as defined by the ability of GFP+ intestinal crypt cells to specifically engraft the intestinal stem cell niche following blastocyst injection and to persist long-term in adult chimeric animals. Recent studies in pancreas, following short-term Exendin-4 stimulation, demonstrate an inducible population of GFP+ cells using both FACS analysis and immunohistochemistry (IHC) in both lines of mice. GFP expression is localized to cells within ductal structures and is absent from islets and acinar cells. This proposal aims to validate the identity and developmental potential of GFP+ putative pancreatic progenitor/stem cells isolated from mTert-GFP transgenic mice. Specifically, we will use in vitro and in vivo model systems, e.g., cell culture, transplantation and blastocyst injection, to establish the potential of these cells to develop into insulin secreting cells. In addition, we propose lineage-tracing studies, using mTert-CreERT2 transgenic mice, to further study the developmental potential of mTert expressing cells in adult pancreas. Type I Diabetes is a major cause of human suffering and results from the destruction of pancreatic beta cells and the loss of insulin production. The ultimate treatment for this condition will involve (1) reversal of the destructive autoimmune attack on beta cells and (2) regeneration of normal beta cells. The identification of new sources of insulin producing cells would have an enormous impact on the future of patients with this disease and on the health care system. Our proposal uses an innovative new model to search for pancreatic progenitor cells in mice with the goal to identify these elusive cells.

描述（由应用提供）：成年干细胞对再生医学，组织修复以及对早期发育事件的研究有着巨大的希望。鉴定出胰岛素产生细胞的新来源可能会为患有糖尿病患者的各种形式的患者提供新的治疗选择。为了响应部分胰腺切除术或生理刺激，胰腺细胞可以通过复制现有细胞和细胞新生成来再生。胰腺祖细胞/干细胞（PPSC）已被认为是新生成的细胞起源，尽管它们的存在仍然存在争议。我们假设（1）存在PPSC的群体，这些群体表达远程酶（MTERT）是其干细胞表型的标记，（2）可以使用MTERT-GFP转基因小鼠和（3）分离PPSC并扩展PPSC，并且随着移植的分化，它们会重新调整正常胰岛细胞的发育。我们已经使用了一种创新方法来产生具有GFP标记的内源性干细胞的转基因小鼠。我们目前有两个独立的MTERT-GFP转基因小鼠系，从中评估了其干细胞电位的GFP+细胞。骨髓和睾丸的验证研究表明，在两个成年干细胞群体中的GFP表达：造血干细胞和雄性生殖细胞。此外，该模型还允许鉴定和隔离推定的肠道干细胞群，这是由GFP+肠道加密细胞在胚泡注射后特异性地植入肠道干细胞小生态位的能力所定义的，并在成年奇物菌中长期持续了长期。短期Exendin-4模拟后，最近在胰腺中进行的研究表明，两种小鼠的GFP+细胞都有诱导的GFP+细胞种群。 GFP表达位于导管结构内的细胞中，胰岛和腺泡细胞不存在。该提案旨在验证从MTERT-GFP转基因小鼠分离的GFP+推定胰祖细胞/干细胞的身份和发育潜力。具体而言，我们将使用体外和体内模型系统，例如细胞培养，移植和胚泡注射，以确定这些细胞发展为胰岛素分泌细胞的潜力。此外，我们提出了使用MTERT-CREERT2转基因小鼠进行谱系追踪研究，以进一步研究成年胰腺中MTERT表达细胞的发育潜力。 I型糖尿病是人类痛苦的主要原因，是胰腺β细胞破坏和胰岛素产生的丧失。对这种情况的最终处理将涉及（1）逆转对β细胞的破坏性自身免疫攻击和（2）正常β细胞的再生。鉴定新的胰岛素产生细胞来源将对这种疾病患者和医疗保健系统的未来产生增强的影响。我们的建议使用创新的新模型来搜索小鼠中的胰腺祖细胞，其目标是识别这些难以捉摸的细胞。