The Role of Clec16a in the Pancreatic Islet

Clec16a 在胰岛中的作用

• 批准号: 8394578
• 负责人: Scott Soleimanpour
• 金额: $ 15.51万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8394578
• 关键词: Affect; Alleles; Area; Autophagocytosis; Autophagosome; Award; Biogenesis; Biological Assay; Cell Line; Cell Proliferation; Cell physiology; Cells; Co-Immunoprecipitations; Complex; Confocal Microscopy; Data; Development; Diabetes Mellitus; Doctor of Medicine; Doctor of Philosophy; Drosophila genus; Electron Microscopy; Electron Transport; Endosomes; Environment; Evaluation; Faculty; Family; Future; Genes; Genetic; Genomics; Glucose; Goals; Growth Factor; Homeobox; Human; Immune; Insulin; Insulin-Dependent Diabetes Mellitus; Islets of Langerhans; Label; Lectin; Ligand Binding; Maintenance; Mediating; Medicine; Mentors; Mentorship; Mission; Mitochondria; Mus; Oxygen Consumption; Pancreas; Pathogenesis; Pathway interactions; Pennsylvania; Physicians; Physiologic pulse; Population; Presynaptic Terminals; Production; Proteins; Regulation; Research; Research Training; Resources; Respiration; Role; Scientist; Signal Pathway; Signal Transduction; Sirolimus; Supervision; Susceptibility Gene; Testing; Tracer; Universities; base; blood glucose regulation; career; career development; didactic education; gene function; glucose tolerance; improved; in vivo; insulin secretion; islet; late endosome; loss of function; medical schools; member; mouse model; novel; professor; receptor; release of sequestered calcium ion into cytoplasm; research study; trafficking; transcription factor

DESCRIPTION (provided by applicant: This proposal details the research and training plan for Scott Soleimanpour, M.D. to develop his academic career as a physician-scientist focused on the thorough understanding of factors which regulate pancreatic ¿-cell replication and survival, with the eventual goal of improving treatment of type 1 diabetes. The career development portion of the proposed K08 award includes an advanced didactic curriculum and formal research mentoring under the supervision of the primary mentor, Doris A. Stoffers, M.D., Ph.D., Associate Professor of Medicine at the University of Pennsylvania School of Medicine, and a multi-disciplinary mentorship committee. The University of Pennsylvania School of Medicine offers a research-rich environment with open access to a wide assortment of expert faculty and resources that will be beneficial in the scientific and professional development of Dr. Soleimanpour. The research proposed in this K08 application will focus on the ¿-cell specific role of Clec16a (C-lectin domain family 16, member A), a type 1 diabetes susceptibility gene and novel target of the essential ¿-cell transcription factor Pdx1. The Drosophila orthologue of Clec16a, Ema, is an endosomal protein vital to endosomal maturation through direct interaction with the Vps-C HOPS complex, which regulates key transitions in endosome and autophagosome maturation. Loss of Ema function leads to increased growth factor signaling due to decreased clearance of ligand bound receptors with resultant synaptic terminal overgrowth. While Clec16a has been suggested to have restricted expression to immune cells, our preliminary evidence indicates that Clec16a is highly expressed in mouse and human islets. Further, loss of function experiments suggest that Clec16a regulates late endosome accumulation, cell replication, insulin secretion, and mitochondrial respiration in ¿-cell lines. Therefore, we hypothesize that Clec16a regulates the ¿ -cell endosomal pathway and the maintenance of ¿-cell mass and function in vivo. Specific Aim I. To test the hypothesis that Clec16a is critical to ¿-cell mass and maintenance of glucose homeostasis. This aim will determine the role of Clec16a via ¿-cell specific loss-of-function experiments in vivo using a conditional Clec16a loxP allele. Experiments will focus on determinations of glucose tolerance and insulin secretion, as well as morphologic analysis of ¿-cell mass related to changes in ¿ -cell proliferation and/or survival. Specific Aim II. To test the hypothesis that the Pdx1 target Clec16a regulates essential aspects of endosome, autophagosome, and mitochondrial function. Experiments will determine the role of Clec16a in endosomal and autophagosome maturation, endosomal trafficking, and mitochondrial biogenesis and calcium flux. In addition, the upstream regulatory role of Pdx1 in regulation of Clec16a and the ¿ -cell endosomal pathway will be determined. Through these specific aims, we will establish the role and functional mechanism for a novel Pdx1 target in the regulation of ¿ -cell mass and function. We will also determine the importance of a target in the endosomal pathway to ¿ -cell function, including insulin secretion, replication/survival, mitochondrial function, and regulation of autophagy, that may open a new areas for future research.

描述（由申请人提供：本提案详细说明了Scott Soleimanpour，M.D.的研究和培训计划。作为一名医生科学家，他致力于深入了解调节胰腺细胞复制和存活的因素，最终目标是改善1型糖尿病的治疗。拟议的K 08奖的职业发展部分包括一个先进的教学课程和正式的研究指导下的主要导师，多丽丝A。Stoffers，医学博士，博士学位、宾夕法尼亚大学医学院医学副教授，以及多学科导师委员会。宾夕法尼亚大学医学院提供了一个研究丰富的环境，可以开放访问各种各样的专家教师和资源，这将有利于Soleimanpour博士的科学和专业发展。这项K 08申请中提出的研究将集中在Clec 16 a（C-凝集素结构域家族16，成员A）的<$-细胞特异性作用上，Clec 16 a是1型糖尿病易感基因，也是必需<$-细胞转录因子Pdx 1的新靶点。果蝇Clec 16 a的直系同源物Ema是一种内体蛋白，通过与Vps-C HOPS复合物直接相互作用对内体成熟至关重要，Vps-C HOPS复合物调节内体和自噬体成熟的关键转变。Ema功能的丧失导致生长因子信号传导增加，这是由于配体结合受体的清除减少，导致突触末端过度生长。虽然Clec 16 a被认为对免疫细胞具有限制性表达，但我们的初步证据表明Clec 16 a在小鼠和人胰岛中高度表达。此外，功能丧失实验表明，Clec 16 a调节晚期内体积累、细胞复制、胰岛素分泌和细胞系中的线粒体呼吸。因此，我们假设Clec 16 a调节了<$-细胞内体途径，并维持了<$-细胞的质量和功能。具体目标一。为了验证Clec 16 a对细胞质量和维持葡萄糖稳态至关重要的假设。该目的将通过使用条件Clec 16 a loxP等位基因的体内细胞特异性功能丧失实验来确定Clec 16 a的作用。实验将侧重于葡萄糖耐量和胰岛素分泌的测定，以及与细胞增殖和/或存活变化相关的细胞质量的形态学分析。具体目标二。检验Pdx 1靶点Clec 16 a调节内体、自噬体和线粒体功能的基本方面的假设。实验将确定Clec 16 a在内体和自噬体成熟、内体运输、线粒体生物发生和钙通量中的作用。此外，还将确定Pdx 1在调节Clec 16 a和细胞内体途径中的上游调节作用。通过这些特定的目标，我们将建立一个新的Pdx 1靶点在调节细胞质量和功能中的作用和功能机制。我们还将确定内体途径中靶点对细胞功能的重要性，包括胰岛素分泌，复制/存活，线粒体功能和自噬调节，这可能为未来的研究开辟新的领域。