Acinar Biology and Pancreatic Disease

腺泡生物学和胰腺疾病

基本信息

批准号：
8429457
负责人：
GUY E GROBLEWSKI
金额：
$ 30.91万
依托单位：
UNIVERSITY OF WISCONSIN-MADISON
依托单位国家：
美国
项目类别：
财政年份：
2006
资助国家：
美国
起止时间：
2006-03-08 至 2016-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8429457
关键词：
Acinar Cell Acinus organ component Acute Affect American Apical Biogenesis Biology Cell membrane Cells Cytoplasmic Granules Cytoplasmic Vesicles Data Development Digestion Disease Endocrine Endosomes Ensure Enzyme Activation Enzyme Inhibition Enzyme Precursors Enzymes Exocrine Glands Exocrine pancreas Exocytosis Food Functional disorder Gland Hybrids Hydrolase Intestines Knowledge Lead Lysosomes Malignant neoplasm of pancreas Mediating Membrane Membrane Proteins Metabolism Minor Molecular Mus Nutrient Pancreas Pancreatic Diseases Pancreatitis Pathway interactions Phase Phosphatidylinositol Phosphates Phosphorylation Physiological Play Population Process Proteins Reaction Regulation Regulatory Pathway Reporting Resistance Role System TPD52 gene Testing Therapeutic Vesicle Zymogen Granules absorption acute pancreatitis apical membrane base calcium-regulated heat-stable protein 28 cell type cellular targeting gastrointestinal system genetic regulatory protein insight mortality novel phosphatidylinositol 3,5-diphosphate premature receptor relating to nervous system research study response syntaxin 3 therapeutic development trafficking tumor vesicle-associated membrane protein

项目摘要

DESCRIPTION (provided by applicant): Exocrine pancreatic acinar cells manufacture, store and release large quantities of hydrolytic enzymes into the intestine that are essential for nutrient digestion and absorption. As food is derived from cellular material, acinar cells retain protective mechanisms to ensure digestive enzymes are not prematurely activated until reaching the intestine. Indeed, aberrant dysregulation of the acinar secretory pathway and premature activation of enzymes has been tied to the development of pancreatitis and pancreatic cancer, which affect over 48,000 Americans each year. It is widely believed that premature digestive enzyme activation is caused by abnormal interactions of the secretory and lysosomal pathways in acini. Thus, knowledge of the basic molecular mechanisms which orchestrate the normal interactions of these pathways is critical to understanding the pathophysiology of pancreatic disease. This proposal investigates a previously unrecognized and important regulatory pathway by which acinar cells modulate digestive enzyme trafficking within the secretory and lysosomal pathways and accordingly regulate digestive enzyme secretion. We recently reported that acinar cells express two distinct populations of zymogen granules (ZGs) based on the expression of the exocytic regulatory proteins VAMP2 and 8. Moreover, our data indicate that maturation of VAMP8 ZGs is directed by Tumor Protein D52 (aka CRHSP-28), which we have shown is uniquely expressed in acini and directly regulates Ca2+-dependent secretion. Unexpectedly, D52 was localized to a unique endosome and lysosome related compartment in acini that we term the endo-lysosomal compartment. Moreover, in CHO-K1 cells, D52 directly regulates lysosmal membrane exocytosis and when over-expressed induces a massive accumulation of cytoplasmic vesicles. This proposal aims to delineate the precise functional roles of VAMP2- and VAMP8- positive ZGs in the acinar secretory response and will test the central hypothesis that D52-regulated trafficking through the endo-lysosomal system controls the biogenesis/maturation of VAMP8-positive ZGs within a unique lysosome-related pathway. Specific Aim 1 will test the hypothesis that VAMP2-positive ZGs mediate the early immediate release of digestive enzymes, whereas VAMP8-positive ZGs mediate the sustained plateau phase of zymogen secretion following acinar stimulation. Specific Aim 2 will test the hypothesis that activation of PIKfyve to produce PtdIns(3,5)P2 in acini regulates endo-lysosomal trafficking to the lysosome and inhibits apical secretion during acinar hyperstimulation. Specific Aim 3 will test the hypothesis that D52 activation of the "minor regulated pathway" mediates the rapid insertion of important regulatory proteins into the apical membrane necessary for granule exocytosis. Understanding the basic molecular principles of how acini uniquely orchestrate the secretory or lysosomal compartments is key to the development of therapeutic strategies aimed at treating pancreatic disease.

描述（由申请人提供）：外分泌胰腺腺泡细胞制造、储存并向肠道释放大量水解酶，这些酶对于营养物质的消化和吸收至关重要。由于食物来源于细胞材料，腺泡细胞保留了保护机制，以确保消化酶在到达肠道之前不会过早激活。事实上，腺泡分泌途径的异常失调和酶的过早激活与胰腺炎和胰腺癌的发展有关，每年影响超过 48,000 名美国人。人们普遍认为消化酶的过早激活是由腺泡中的分泌途径和溶酶体途径的异常相互作用引起的。因此，了解协调这些途径正常相互作用的基本分子机制对于理解胰腺疾病的病理生理学至关重要。该提案研究了以前未被认识的重要调节途径，腺泡细胞通过该途径调节分泌和溶酶体途径内的消化酶运输，并相应地调节消化酶分泌。我们最近报道，基于胞吐调节蛋白 VAMP2 和 8 的表达，腺泡细胞表达两种不同的酶原颗粒 (ZG) 群体。此外，我们的数据表明 VAMP8 ZG 的成熟是由肿瘤蛋白 D52（又名 CRHSP-28）指导的。），我们已经证明它在腺泡中独特表达，并直接调节 Ca2+ 依赖性分泌。出乎意料的是，D52 定位于腺泡中独特的内体和溶酶体相关区室，我们称之为内溶酶体区室。此外，在 CHO-K1 细胞中，D52 直接调节溶酶膜胞吐作用，并且当过度表达时会诱导细胞质囊泡的大量积累。该提案旨在描述 VAMP2 和 VAMP8 阳性 ZG 在腺泡分泌反应中的精确功能作用，并将测试以下中心假设：D52 调节的通过内溶酶体系统的运输控制 VAMP8 阳性 ZG 的生物发生/成熟。独特的溶酶体相关途径。具体目标 1 将检验以下假设：VAMP2 阳性 ZG 介导消化酶的早期立即释放，而 VAMP8 阳性 ZG 介导腺泡刺激后酶原分泌的持续平台期。具体目标 2 将测试以下假设：激活 PIKfyve 在腺泡中产生 PtdIns(3,5)P2 可调节内溶酶体向溶酶体的运输，并在腺泡过度刺激期间抑制顶端分泌。具体目标 3 将检验以下假设：D52 激活“次要调节途径”介导重要调节蛋白快速插入到颗粒胞吐作用所需的顶膜中。了解腺泡如何独特地协调分泌或溶酶体区室的基本分子原理是制定旨在治疗胰腺疾病的治疗策略的关键。