Search for new MODY genes and molecular studies of their function in beta cells

寻找新的 MODY 基因并对其在 β 细胞中的功能进行分子研究

• 批准号: 8107365
• 负责人: Alessandro Doria
• 金额: $ 69.58万
• 依托单位: JOSLIN DIABETES CENTER
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-08-05 至 2015-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8107365
• 关键词: 3' Untranslated Regions; 4q32; 5' Flanking Region; Adult; Affect; Amputation; Animals; Apoptosis; BLK gene; Beta Cell; Biological; Blindness; Build-it; Cataloging; Catalogs; Cell Line; Cell physiology; Cells; Chromosomes; Chronic Kidney Failure; Code; Collaborations; Collection; Computer Simulation; Congenital Abnormality; Custom; DNA Resequencing; Data; Databases; Development; Diabetes Mellitus; Diagnosis; Drug Delivery Systems; Epidemic; Epidemiologist; Etiology; Family; Frequencies; Funding; Genes; Genetic; Genetic Markers; Genetic Translation; Genomics; Glucose; Goals; Grant; Haplotypes; Heart Diseases; Human; In Vitro; Inheritance Patterns; Insulin; Intervention; Knockout Mice; Knowledge; Lead; Limb structure; Link; Location; Methods; Molecular; Mus; Mutate; Non-Insulin-Dependent Diabetes Mellitus; Oligonucleotide Microarrays; Oral; Pancreas; Pathway interactions; Peripheral; Pharmaceutical Preparations; Phenotype; Phosphorylation; Physiological; Protein Tyrosine Kinase; Proteins; Research; Risk Factors; Role; Stroke; System; Technology; Tissues; Variant; base; blood glucose regulation; burden of illness; cell type; drug development; early onset; gene function; glucose metabolism; in vivo; insight; insulin secretion; islet; loss of function; mRNA Stability; member; next generation; novel; overexpression; positional cloning; prevent; promoter; response; transcription factor

DESCRIPTION (provided by applicant): Despite many advances in treatment, diabetes continues to be the leading cause of chronic renal failure, adult blindness and limb amputation, and a major risk factor for heart disease, stroke and birth defects. To decrease the burden of this disease, a better understanding of the molecular mechanisms regulating insulin secretion by b-cell and insulin action in peripheral tissues is urgently needed, so that new interventions can be developed. Our strategy is to gain this knowledge through genetic studies of maturity-onset diabetes of the young (MODY) - an autosomal dominant form of early-onset diabetes. This approach has led during the previous funding period to the identification of the tyrosine kinase BLK as a previously unrecognized modulator of b-cell function that acts as a stimulator of insulin synthesis and secretion in response to glucose. In this grant renewal application, we propose to continue this research by seeking further insights onto the molecular mechanisms through which BLK modulates b-cell function and by pursuing the positional cloning of a new MODY gene placed on chromosome 4q32, where we have observed significant linkage in the Joslin collection of MODY families. Our specific aims are: 1. To investigate the molecular mechanisms by which the MODY gene BLK impacts b-cell function. We will perform in vitro and in vivo studies to systematically examine the effects of the BLK gene on b-cell function, proliferation, and survival. We will first investigate the effects of gain or loss of function of BLK in MIN6 b-cells. We will then study an existing global BLK KO mouse as well as an inducible-b-cell-specific BLK KO mouse that we will create during this grant. Mice will be phenotyped through detailed physiological studies to characterize their glucose homeostasis and b-cell function. 2. To identify and functionally characterize the sequence variants underlying the new MODY locus on chromosome 4q32. We will use next-gen sequencing technologies to compile a comprehensive catalog of the rare variants carried by the diabetes-linked haplotypes at 4q32. From these, we will select a set of candidate variants that have a high in silico likelihood of being involved in the etiology of MODY in these families. We will then determine which of these variants are causally linked to diabetes by means of functional studies. Several important features distinguish our proposal. First, it is based on extensive preliminary data concerning the role of BLK in b-cell physiology and demonstrating the feasibility of using next-gen sequencing for positional cloning. Second, it takes advantage of one of the largest available collections of MODY families unaccounted for by known MODY genes. Third, it builds on the ongoing collaboration between a genetic epidemiologist and a b-cell molecular physiologist with complementary expertise. Finally, and most importantly, our proposal has an especially high translational value, potentially leading to the identification of novel drug targets, with critical implications for the development of new interventions to curb the on-going diabetes epidemic. PUBLIC HEALTH RELEVANCE: The goal of this project is to identify genes involved in the development of MODY and understand the mechanisms through which these affect glucose homeostasis. Availability of new genetic markers of MODY would facilitate the diagnosis of this form of diabetes, with implications for treatment optimization (e.g., for transferring previously undiagnosed MODY from insulin therapy to oral medications). Perhaps more importantly, understanding the function of the genes may point to as yet undiscovered molecular pathways regulating insulin secretion and action, which may in turn suggest novel targets for the development of new drugs to prevent or treat common, multifactorial forms of type 2 diabetes.

描述（由申请人提供）：尽管在治疗方面取得了许多进步，但糖尿病仍然是慢性肾衰竭、成人失明和截肢的主要原因，也是心脏病、中风和出生缺陷的主要危险因素。为了减轻这种疾病的负担，迫切需要更好地了解b细胞调节胰岛素分泌和外周组织胰岛素作用的分子机制，从而开发新的干预措施。我们的策略是通过对年轻人成熟型糖尿病（MODY）的遗传研究来获得这些知识，MODY是一种常染色体显性早发型糖尿病。在之前的资助期内，这种方法已经确定了酪氨酸激酶BLK作为b细胞功能的一种以前未被识别的调节剂，作为胰岛素合成和分泌的刺激物，以响应葡萄糖。在本次续期申请中，我们建议通过进一步深入了解BLK调节b细胞功能的分子机制，并通过对放置在染色体4q32上的一个新的MODY基因进行定位克隆来继续这项研究，我们已经在Joslin收集的MODY家族中观察到显著的连锁。我们的具体目标是：1。探讨MODY基因BLK影响b细胞功能的分子机制。我们将进行体外和体内研究，系统地检查BLK基因对b细胞功能、增殖和存活的影响。我们将首先研究BLK在MIN6 b细胞中功能的获得或丧失的影响。然后，我们将研究现有的全球BLK KO小鼠以及我们将在此授权期间创建的可诱导b细胞特异性BLK KO小鼠。小鼠将通过详细的生理研究来表征其葡萄糖稳态和b细胞功能。2. 鉴定4q32染色体上新的MODY位点的序列变异并对其进行功能表征。我们将使用新一代测序技术，对4q32上与糖尿病相关的单倍型携带的罕见变异进行全面的编目。从中，我们将选择一组候选变异，这些变异在这些家庭中有很高的硅可能性参与MODY的病因学。然后，我们将通过功能研究确定哪些变异与糖尿病有因果关系。我们的建议有几个重要的特点。首先，它是基于大量关于BLK在b细胞生理学中的作用的初步数据，并证明了使用下一代测序进行定位克隆的可行性。其次，它利用了已知的MODY基因中最大的MODY家族集合之一。第三，它建立在遗传流行病学家和具有互补专业知识的b细胞分子生理学家之间持续合作的基础上。最后，也是最重要的是，我们的建议具有特别高的转化价值，可能导致识别新的药物靶点，对开发新的干预措施以遏制持续的糖尿病流行具有重要意义。