Pathophysiology of Chronic Pancreatitis Associated with Misfolded PNLIP Risk Variants

与错误折叠的 PNLIP 风险变异相关的慢性胰腺炎的病理生理学

基本信息

批准号：
10595017
负责人：
Xunjun Xiao
金额：
$ 45.11万
依托单位：
WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-04-01 至 2025-12-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10595017
关键词：
Acinar Cell Age Animal Model Animals Apoptotic Atrophic Automobile Driving Biological Biological Assay Cell Culture Techniques Cell Death Cells Chinese Complex Data Development Disease Disease Progression Endoplasmic Reticulum Enzymes Ethanol Event Exhibits Fibrosis Functional disorder Genes Genetic Predisposition to Disease Goals Human In Vitro Induced Mutation Infiltration Inflammation Inflammatory Knowledge Lipase Measures Mediating Modeling Mus Necrosis Onset of illness Pancreas Pancreatic Injury Pancreatic enzyme Pancreatitis Pathogenesis Pathogenicity Pathologic Pathology Pathway interactions Patients Peptide Hydrolases Phenotype Pre-Clinical Model Predisposition Prevalence Process Protein Isoforms Proteins Recurrence Research Risk Risk Factors Role Signal Pathway Signal Transduction Testing Therapeutic Trypsin Trypsinogen Variant Western Blotting acute pancreatitis age related chronic pancreatitis early onset end stage disease endoplasmic reticulum stress feeding gain of function genetic risk factor human model inhibitor insight misfolded protein mouse model mutant novel novel therapeutic intervention pre-clinical prevent protein degradation protein misfolding proteostasis proteotoxicity response risk variant stem targeted treatment theories therapeutic target therapy development transcriptome sequencing variant of interest variant of unknown significance

项目摘要

PROJECT SUMMARY The primary goal of this application is to determine the mechanisms by which pancreatic triglyceride lipase (PNLIP) variants increase the risk for chronic pancreatitis (CP) in humans. Proteotoxicity caused by misfolded mutant digestive enzymes has been recognized as a novel trypsin-independent mechanism for CP, referred to as misfolding CP. Recent studies indicate that the development of CP is often a process of discrete recurrent acute pancreatitis (RAP) driven by genetic risk factors. Restoring proteostasis in the presence of misfolded proteins is an attractive therapeutic strategy to stop RAP and prevent progression to end-stage disease in misfolding CP patients. Critical knowledge gaps remain in understanding how misfolded proteins contribute to pancreatitis onset and progression primarily stemming from the paucity of animal models that recapitulate misfolding CP in humans. We have developed a pre-clinical model of human PNLIP T221M disease. PNLIP has no known role in trypsinogen activation or trypsin inactivation. In vitro, PNLIP T221M misfolds and causes proteotoxicty by triggering unmitigated ER stress. Our preliminary data show that Pnlip T221M mice exhibit progressive pancreatic acinar atrophy, inflammatory cell infiltration, fibrosis, and apoptotic and necrotic cell death; the pathological changes occur as early as at 1 month and become severe at 3-4 month. Our working hypothesis is that proteins encoded by risk variants of PNLIP cause CP by gain-of-function proteotoxicity through protein misfolding. To test this hypothesis, first we will systematically characterize Pnlip T221 mice including CP-like phenotypes, secondary complications, and the susceptibility to pancreatic injury when being challenged with ethanol feeding. Second, we will methodically investigate early biological responses triggered by pancreatic expression of pathogenic PNLIP T221M in mice to uncover potential novel targets to halt or prevent disease onset and progression. Third, we will assess the prevalence of protein misfolding and proteotoxicity underlies the disease mechanism of PNLIP variants of uncertain significance (VUS) found in CP patients using cell cultures and another mouse model of Pnlip F300L. Completion of these studies will establish mutation-induced misfolding of digestive enzymes as a relevant disease mechanism in the pathogenesis of CP and will identify potential therapeutic targets to stop RAP and prevent CP.

项目概要本申请的主要目标是确定胰腺甘油三酯脂肪酶的作用机制 (PNLIP) 变异会增加人类患慢性胰腺炎 (CP) 的风险。错误折叠引起的蛋白质毒性突变消化酶已被认为是一种新型的不依赖胰蛋白酶的 CP 机制，称为作为错误折叠的CP。最近的研究表明，CP的发展往往是一个离散的、反复发生的过程。由遗传危险因素驱动的急性胰腺炎（RAP）。在存在错误折叠的情况下恢复蛋白质稳态蛋白质是一种有吸引力的治疗策略，可以阻止 RAP 并防止进展为终末期疾病错误折叠的 CP 患者。在理解错误折叠蛋白质如何促进胰腺炎的发病和进展主要是由于缺乏能够概括的动物模型人类的CP错误折叠。我们开发了人类 PNLIP T221M 疾病的临床前模型。 PNLIP 在胰蛋白酶原激活或胰蛋白酶失活中没有已知的作用。在体外，PNLIP T221M 错误折叠并导致通过触发未缓解的内质网应激而产生蛋白质毒性。我们的初步数据显示 Pnlip T221M 小鼠表现出进行性胰腺腺泡萎缩、炎症细胞浸润、纤维化、细胞凋亡和坏死死亡;病理变化最早在1个月时出现，3-4个月时病情加重。我们的工作假设是 PNLIP 风险变异编码的蛋白质通过功能获得性蛋白毒性导致 CP 通过蛋白质错误折叠。为了检验这一假设，首先我们将系统地表征 Pnlip T221 小鼠包括 CP 样表型、继发并发症以及胰腺损伤的易感性乙醇喂养的挑战。其次，我们将系统地研究引发的早期生物反应通过小鼠中致病性 PNLIP T221M 的胰腺表达来发现潜在的新靶标，以阻止或阻止预防疾病的发生和进展。第三，我们将评估蛋白质错误折叠的发生率和蛋白质毒性是 CP 中发现的意义不确定的 PNLIP 变异 (VUS) 疾病机制的基础使用细胞培养物和 Pnlip F300L 的另一种小鼠模型的患者。完成这些研究将建立突变诱导的消化酶错误折叠作为相关疾病机制 CP 的发病机制，并将确定阻止 RAP 和预防 CP 的潜在治疗靶点。