G Protein Mediated Mechanisms of Beta Cell Death Dysfunction and Decompensation in Diabetes

G蛋白介导的糖尿病β细胞死亡功能障碍和失代偿机制

• 批准号: 9898293
• 负责人: Michelle E Kimple
• 金额: --
• 依托单位: WM S. MIDDLETON MEMORIAL VETERANS HOSP
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-04-01 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9898293
• 关键词: Aging; Alpha Cell; B-Cell Activation; Beta Cell; Blood Circulation; Blood Glucose; C-terminal; Caring; Cell Death; Cell membrane; Cell physiology; Cells; Chemicals; Child; Chronic Disease; Communication; Complex; Coupled; Coupling; Critical Pathways; Cyclic AMP; Data; Diabetes Mellitus; Diabetes prevention; Dinoprostone; Etiology; Exocytosis; Exposure to; Failure; Financial compensation; Fluorescence Resonance Energy Transfer; Functional disorder; GLP-I receptor; GTP-Binding Protein alpha Subunits; GTP-Binding Protein alpha Subunits, Gs; GTP-Binding Proteins; General Population; Glucose; Goals; Growth; Health; Hormones; Human; Hyperglycemia; Image; Immune; Individual; Insulin; Islet Cell; Knockout Mice; Label; Laboratories; Life Style; Link; Longevity; Mediating; Membrane; Methods; Microscopy; Molecular; Mus; Obesity; Pancreas; Paracrine Communication; Pathway interactions; Pharmaceutical Preparations; Population; Pre-Clinical Model; Prediabetes syndrome; Prevalence; Prevention therapy; Process; Production; Proteins; Public Health; RNA Splicing; Regulation; Research; Residual state; Resistance; Role; Signal Pathway; Signal Transduction; Signaling Molecule; Structure of beta Cell of islet; Sulfonylurea Compounds; Tail; Testing; Therapeutic; Time; Tissues; Variant; Veterans; Work; autocrine; base; cell type; cellular targeting; cost; diabetes risk; diabetic; diabetic patient; diabetogenic; experimental study; functional loss; glucagon-like peptide 1; improved; innovation; islet; lifetime risk; mimetics; mouse model; novel; overexpression; paracrine; patch clamp; patient population; preservation; prevent; programs; receptor; recruit; therapeutic target

Diabetes is a costly and complex chronic illness and a serious public health problem. Currently, the prevalence of diabetes in the VA patient population is approximately 25%, with many more Veterans at risk for diabetes due to obesity, aging, and poor lifestyle, as well as exposure to known diabetogenic chemicals in the line of duty. The number of Veterans with diabetes is certain to increase over the next decades, as the children of today have an estimated overall lifetime risk of developing diabetes of nearly 50%. Therefore, developing new methods for preventing diabetes and identifying and properly treating diabetic patients is very timely and of great significance. By definition, diabetes occurs when insufficient insulin is produced from the β-cells of the pancreas to properly stimulate the body cells to take up glucose from the blood and shut off production of more glucose. While they have different etiologies, the pathophysiology of type 1 (immune-mediated) and type 2 (obesity-related) diabetes is increasingly being linked by dysfunctional cellular and molecular signaling processes that act in the insulin-secreting β-cells. One molecule that is a cornerstone of our research program, termed Gαz, has the potential to act as a hub in one or more signaling processes impacting on β-cell function, replication, growth and/or survival. Thus, targeting these dysfunctional Gαz signaling processes could potentially help to improve functional β-cell mass in both types of diabetes. Our long-term goal is to fully characterize the Gαz activation and signaling pathways in the diabetic state at the organismal, tissue, cellular, and molecular levels, guiding us in modulating this pathway for preventative and therapeutic purposes. The overall objective of this work, which is the next logical step in pursuit of our goal, is to characterize the molecular and cellular signaling pathways responsible for the impact of Gαz signaling on diabetes pathophysiology. Our central hypothesis is activated β-cell Gαz negatively modulates specific intracellular and autocrine/paracrine signaling pathways critical for β-cell compensation, ultimately leading to β-cell death and dysfunction and exacerbating the diabetic condition. We will test our central hypothesis in multiple pre-clinical models of diabetes and, thereby, accomplish the objective of this application, by pursuing the following three specific aims: (1) Determine the differential effects of EP3 receptor variant/Gαz coupling on mechansims mediating insulin exocytosis; (2) Elucidate the mechanisms underlying the cAMP- independent regulation of beta-cell function by Gαz; and (3) Elucidate the effect of Gαz signaling on intra-islet communication pathways that regulate beta-cell replication and survival. With the completion of these aims, we anticipate a much more complete understanding of the role of the β-cell and its signaling molecules in the pathophysiology of diabetes. Ultimately, isolating Gαz effects to the β-cell and fully characterizing its signaling mechanisms will aid in rationally and specifically targeting this pathway in the β-cell to improve diabetic β-cell dysfunction and loss of functional β-cell mass.

糖尿病是一种昂贵而复杂的慢性疾病，也是一个严重的公共卫生问题。目前，