Cytoskeleton-mediated regulation of insulin secretion hot spots in pancreatic beta cells

细胞骨架介导的胰腺β细胞胰岛素分泌热点的调节

• 批准号: 10679903
• 负责人: Margret A Fye
• 金额: $ 3.3万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10679903
• 关键词: Actins; Actomyosin; Address; Adhesions; Architecture; Area; Beta Cell; Biological Assay; Blood Glucose; Blood Vessels; Cell membrane; Cell physiology; Cells; Compensation; Complex; Computer Analysis; Coupled; Couples; Cytoskeletal Modeling; Cytoskeleton; Diabetes Mellitus; Docking; Dominant-Negative Mutation; Dyes; Elements; Event; Exocytosis; Extracellular Matrix; Face; FluoZin-3; Fluorescence Resonance Energy Transfer; Focal Adhesions; Glucose; Guanine Nucleotide Exchange Factors; Hot Spot; Imaging Techniques; Insulin; Insulin Resistance; Islets of Langerhans; Knowledge; Label; Laboratories; Location; Mediating; Mediator; Microtubule Depolymerization; Microtubules; Minus End of the Microtubule; Modeling; Molecular; Monomeric GTP-Binding Proteins; Morphology; Mus; Myosin Type II; Neurons; Non-Insulin-Dependent Diabetes Mellitus; Nucleotides; Nutrient; Peripheral; Play; Plus End of the Microtubule; Positioning Attribute; Process; Proteins; Regulation; Role; Signal Transduction; Structure of beta Cell of islet; Testing; Therapeutic; Tissues; Total Internal Reflection Fluorescent; Visualization; blood glucose regulation; improved; insulin granule; insulin regulation; insulin secretion; islet; live cell imaging; novel; pharmacologic; sensor; therapeutic target; ultra high resolution; voltage

Project Summary Insulin secretion from pancreatic β cells is crucial to maintaining blood glucose homeostasis, allowing cells throughout the body to take up glucose from the blood and obtain nutrients for normal cellular processes. In type 2 diabetes, however, peripheral tissues become insulin resistant, β cells over-secrete insulin to compensate, and eventually β cells become dysfunctional. It is therefore necessary to thoroughly understand the mechanisms of insulin secretion in order to identify potential therapeutic targets for type 2 diabetes treatment. Insulin secretion is known to predominantly occur at the vascular face of the β cell, at regions termed “hot spots.” Hot spots are characterized by proteins common to the active zone of neurons as well as proteins of cortical microtubule-stabilizing complexes and focal adhesions. Our laboratory has also found that microtubule destabilization promotes insulin secretion specifically at hot spots. Others have shown that the actin cytoskeleton also plays a critical regulatory role in insulin secretion. Given the known connections of microtubules, focal adhesions, and actin with known hot spot proteins, it is likely that the interplay of these cytoskeletal elements is essential for the hot spot organization and function. I therefore hypothesize that insulin secretion hot spots are “secreting adhesions”: mechanosensitive subcellular domains which use cytoskeletal regulation to accomplish directed and clustered secretion. My specific aims are to 1) characterize the cytoskeleton networks, their interplay, and other hot spot components in β cells; and to 2) test if MT- regulated RhoA-dependent contractility promotes clustered secretion via secreting adhesion assembly. To address these aims, I will use high- and super-resolution fixed and live-cell imaging techniques combined with computational analyses. Improving the understanding of hot spot identity and establishment via the cytoskeleton will contribute to overall knowledge of insulin secretion, and potentially uncover novel targets for diabetes therapeutics.

项目摘要 胰腺β细胞的胰岛素分泌对于维持血糖稳态至关重要，允许细胞 通过身体从血液中摄取葡萄糖并获得正常细胞过程的营养。在 然而，2型糖尿病，周围组织成为胰岛素耐药性，β细胞过度分泌胰岛素 补偿，最终β细胞变得功能失调。因此有必要彻底理解 胰岛素分泌的机制，以鉴定2型糖尿病的潜在治疗靶点 治疗。已知胰岛素分泌主要发生在β细胞的血管面上，在区域 称为“热点”。热点的特征是神经元的活性区域和 皮质微管稳定复合物和焦点粘合剂的蛋白质。我们的实验室还发现 微管破坏稳定会促进专门在热点处的胰岛素分泌。其他人表明 肌动蛋白细胞骨架在胰岛素分泌中也起着关键的调节作用。鉴于已知的联系 微管，焦点广告和带有已知热点蛋白的肌动蛋白，这些相互作用很可能 细胞骨架元素对于热点组织和功能至关重要。因此，我假设胰岛素 分泌热点是“分泌广告”：使用细胞骨架的机械敏感亚细胞域 法规以完成定向和聚集的分泌。我的具体目的是1）表征 β细胞中的细胞骨架网络，它们的相互作用和其他热点成分； 2）测试是否 受调节的Rhoa依赖性收缩力通过分泌粘合剂促进聚类的分泌 集会。为了解决这些目标，我将使用高分辨率和超分辨率固定和现场电池成像技术 结合计算分析。通过通过 细胞骨架将有助于胰岛素分泌的总体知识，并有可能发现新颖的靶标 用于糖尿病治疗。