Novel mechanisms to increase beta cell regeneration by p27

p27 促进 β 细胞再生的新机制

• 批准号: 8318235
• 负责人: Senta K Georgia
• 金额: $ 3.04万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-10 至 2013-01-18
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8318235
• 关键词: Ablation; Address; Adult; American; Autoimmune Process; Award; Benchmarking; Beta Cell; Binding; Biological Assay; Biological Models; Biology; Blood Glucose; Bypass; Cell Culture Techniques; Cell Cycle; Cell Cycle Arrest; Cell Cycle Progression; Cell Cycle Regulation; Cell Differentiation process; Cell Proliferation; Cells; Cyclins; Data; Data Analyses; Development Plans; Diabetes Mellitus; Diet; Education; Educational process of instructing; Educational workshop; Embryo; Embryonic Development; Endocrine; Endocrinology; Enteroendocrine Cell; Environment; Equilibrium; Equipment; Exposure to; Faculty; Fostering; Freedom; Genetic; Genetic Transcription; Grant; Healthcare Systems; Human; Hyperglycemia; Immersion Investigative Technique; In Vitro; Insulin; Insulin Resistance; International; Knockout Mice; Mediating; Mentorship; Metabolic Diseases; Modeling; Monomeric GTP-Binding Proteins; Morphogenesis; Morphology; Mus; Natural regeneration; Organogenesis; Pancreas; Population; Positioning Attribute; Prediabetes syndrome; Production; Proteins; Public Health; Publications; Publishing; Regenerative Medicine; Research; Research Personnel; Research Proposals; Resources; Role; Small Interfering RNA; Stem cells; TC1 Cell; Techniques; Testing; Therapeutic Studies; Time; Transfection; Transgenic Mice; Tumor Cell Line; Up-Regulation; Work; adult stem cell; base; betacell therapy; career; career development; cell motility; cost; diabetic; diabetic patient; fetal; improved; in vivo; in vivo Model; inhibitor/antagonist; interest; islet; mouse model; novel; overexpression; postnatal; progenitor; programs; protein function; public health relevance; research study; response; self-renewal; stem cell population; symposium; therapy design; ubiquitin-protein ligase

DESCRIPTION (provided by applicant): As of 2008, approximately 81 million people in the US have diabetes or pre-diabetes. As complications arising from diabetes represent the single largest cost to the US health care system, it is an imperative public health crisis to develop better therapies that treat, and potentially cure, the underlying cause of diabetes: hyperglycemia resulting from insufficient insulin production, due to either autoimmune destruction of insulin-producing beta cells or an inadequate mass of functional insulin-producing beta cells. This application seeks to improve our understanding of how to increase beta cell mass by investigating the mechanisms that govern the expansion of beta mass during embryogenesis and in response to diet-induced insulin resistance. Specifically, we propose to investigate how mechanisms that govern the accumulation or degradation of p27, a protein that functions to inhibit the expansion of beta cell mass, can be exploited to expand beta cell mass. We propose that Spy1A, a cell novel cell cycle regulator that can bypass p27-mediated inhibition of cell expansion, can be overexpressed to increase beta cell mass. We have also identified that Rap1A, a small GTPase activated during beta cell differentiation, may induce cell cycle arrest by upregulation of p27. We will use transgenic mouse models to investigate if spy1A overexpression or rap1A deletion can increase beta cell mass. We have discovered previously unidentified roles for skp2 and p27 in enteroendocrine differentiation from gut progenitor cells, which will serve as an alternative in vivo model to understand how beta cells may differentiate from adult progenitor cells to expand beta cell mass. We will use purified cell populations, cell culture models, lentiviral transfections, and siRNA knockdown experiments to assess how these proteins activate or repress p27 transcription and degradation. We expect that the results from the proposed aims of this grant will directly contribute to potential therapies to regenerate functional beta cell mass for diabetic patients. The theme of this research directly addresses the Beta Cell Therapy Research Program programmatic thrust of the NIDDK's division of Diabetes, Endocrinology and Metabolic Diseases. The research proposed in this grant will foster the transition of Dr. Senta K. Georgia from junior faculty to an independent research career. The theme of this grant is an extension of her established publication record in the field of beta cell differentiation and regeneration. Though she is building on her previous publication record, the experiments proposed in this application expose her to new techniques and new model systems for understanding beta cell differentiation and expansion. Under the mentorship of Dr. Mart¿n Mart¿n and co-mentorship of Dr. Anil Bhushan, Dr. Georgia will pursue cutting edge research at UCLA, with access to state-of-the-art equipment, cores, and resources to facilitate the production and analysis of data. In addition to her research, this proposal outlines specific mentorship activities that will foster Dr. Georgia's independence, including (but not limited to) attendance at new investigator workshops, presentation of her work at relevant international conferences, and detailed benchmarking of her progress by a personalized career development plan. We expect that the research proposed in this application will result in 3 high impact publications within the next 5 years that will advance the field of regenerative medicine and islet biology. With protected research time, freedom from the responsibility of didactic teaching responsibilities, participation in intellectually stimulating and education seminars, exposure to new model systems and new techniques, immersion in a stimulating and supportive environment, and active mentorship to encourage critical assessment of data and publication, we are very confident that Dr. Georgia will be an outstanding candidate for a tenure track independent research position at the end of the granting period of this award. PUBLIC HEALTH RELEVANCE: The 81 million Americans that are diabetic or are pre-diabetic suffer from the condition because the body's insulin-producing cells, either because of autoimmune destruction or the inability of the cells to function properly, are unable to maintain normal blood sugar levels. The proposed studies are targeted to understand how functional insulin-producing cells normally reproduce themselves. Results from these studies will contribute to the design of therapies to generate more insulin-producing cells as an effective cure for diabetes.

描述(申请人提供)：截至2008年，美国约有8100万人患有糖尿病或糖尿病前期。由于糖尿病引起的并发症是美国医疗体系最大的单一成本，开发更好的疗法来治疗并有可能治愈糖尿病的根本原因：胰岛素分泌不足导致的高血糖，要么是产生胰岛素的β细胞的自身免疫破坏，要么是产生胰岛素的功能性β细胞数量不足，这是一场势在必行的公共卫生危机。 这项应用旨在通过研究在胚胎发育过程中控制β细胞质量扩大的机制以及对饮食诱导的胰岛素抵抗的反应来提高我们对如何增加β细胞质量的理解。具体地说，我们建议研究如何利用控制p27积累或降解的机制来扩大β细胞质量。p27是一种抑制β细胞团扩张的蛋白质。我们认为Spy1A是一种新的细胞周期调节因子，可以绕过p27介导的细胞扩张抑制，可以过表达来增加β细胞质量。我们还发现，在β细胞分化过程中激活的一种小GTP酶Rap1a可能通过上调p27而导致细胞周期停滞。我们将使用转基因小鼠模型来研究Spy1A的过度表达或Rap1A的缺失是否会增加β细胞质量。我们已经发现了之前未知的Skp2和p27在肠道前体细胞向肠内分泌分化中的作用，这将作为一种替代的体内模型来理解β细胞如何从成体前体细胞分化为扩张的β细胞团。我们将使用纯化的细胞群体、细胞培养模型、慢病毒转染和siRNA敲除实验来评估这些蛋白质如何激活或抑制p27的转录和降解。我们预计，这笔赠款拟议目标的结果将直接有助于潜在的治疗方法，为糖尿病患者再生功能性β细胞团。这项研究的主题直接涉及NIDDK糖尿病、内分泌学和代谢性疾病部门的Beta细胞治疗研究计划计划推力。 这项拨款中提议的研究将促进Senta K.乔治亚博士从初级教员到独立研究生涯的过渡。这笔赠款的主题是她在贝塔细胞分化和再生领域已有的出版记录的延伸。虽然她是建立在她之前的发表记录的基础上，但本申请中提出的实验使她接触到了了解β细胞分化和扩张的新技术和新模型系统。在马丁·马特恩博士和阿尼尔·布山博士的共同指导下，乔治亚博士将在加州大学洛杉矶分校从事尖端研究，获得最先进的设备、核心和资源，以促进数据的产生和分析。除了她的研究之外，这项提案还概述了将促进乔治亚博士独立的具体指导活动，包括(但不限于)参加新的研究人员研讨会，在相关国际会议上介绍她的工作，以及通过个性化的职业发展计划对她的进展进行详细的基准比较。 我们预计，这项申请中提出的研究将在未来5年内产生3篇影响力较大的出版物，推动再生医学和胰岛生物学领域的发展。有了受保护的研究时间，摆脱了教学责任的责任，参加了智力刺激和教育研讨会，接触到了新的模型系统和新技术，沉浸在一个激励和支持的环境中，以及积极的指导以鼓励对数据和出版物进行批判性评估，我们非常有信心，乔治亚博士将成为终身教职的杰出候选人，在本奖项授予期限结束时担任独立研究职位。 与公共健康相关：8100万患有糖尿病或糖尿病前期的美国人患有这种疾病，因为身体的胰岛素分泌细胞要么是由于自身免疫破坏，要么是因为细胞无法正常运作，无法维持正常的血糖水平。这项拟议的研究旨在了解功能正常的胰岛素产生细胞如何自我繁殖。这些研究的结果将有助于设计治疗方案，以产生更多的胰岛素产生细胞，作为治疗糖尿病的有效方法。