Chymotrypsin C in pancreatitis

描述（由申请人提供）：本资助的主要目的是确定凝乳胰蛋白酶C （CTRC）突变作为人类慢性胰腺炎危险因素的机制。该项目是我们广泛的长期研究计划的一部分，旨在了解与人类胰腺炎相关的遗传风险因素的分子机制。迄今为止，这些研究将生化和细胞生物学方法与人类遗传关联研究获得的数据结合起来，建立了复发性急性和慢性胰腺炎的分子疾病模型。我们目前的工作假设是胰腺炎的遗传风险是通过两种独立的病理途径介导的，这可能导致腺泡细胞损伤。在胰蛋白酶依赖的病理途径中，胰蛋白酶原对活性胰蛋白酶的胰腺内自激活是导致细胞损伤的原因；而在错误折叠依赖的病理途径中，错误折叠突变蛋白的保留可以通过诱导内质网应激来损害腺泡细胞。在之前的资助期内，我们确定了CTRC突变是慢性胰腺炎的高度重要危险因素，这些突变主要通过胰蛋白酶依赖途径发挥作用，而CTRC突变的一个子集也参与错误折叠依赖途径。在下一个资助期，我们的目标是在体内验证我们的结论，并创建和表征小鼠模型，以测试小鼠Ctrc基因缺失是否会增加胰腺内胰蛋白酶原激活和胰腺炎反应；以及在小鼠胰腺中转基因表达错误折叠的人CTRC突变体是否会导致内质网应激、腺泡细胞损伤和对胰腺炎的易感性增加。

DESCRIPTION (provided by applicant): The main objective of this grant is to determine the mechanisms by which chymotrypsin C (CTRC) mutations act as risk factors for chronic pancreatitis in humans. The project forms a part of our broad, long-term research program to understand the molecular mechanisms of genetic risk factors associated with human pancreatitis. These studies so far combined biochemical and cell biological approaches with data obtained from human genetic association studies to formulate a molecular disease model for recurrent acute and chronic pancreatitis. Our current working hypothesis is that genetic risk in pancreatitis is mediated via two independent pathological pathways, which can result in acinar cell damage. In the trypsin-dependent pathological pathway intra-pancreatic autoactivation of trypsinogen to active trypsin is responsible for cell injury; whereas in the misfolding-dependent pathological pathway retention of misfolded mutant proteins can damage acinar cells through induction of endoplasmic reticulum stress. In the previous funding period we established that CTRC mutations are highly significant risk factors for chronic pancreatitis and these mutations exert their effect primarily through the trypsin-dependent pathway, while a subset of CTRC mutants also engages the misfolding-dependent pathway. In the next funding period our aim is to validate our conclusions in vivo and create and characterize mouse models that will test whether genetic deletion of mouse Ctrc increases intra-pancreatic trypsinogen activation and pancreatitis responses; and whether transgenic expression of a misfolding human CTRC mutant in the mouse pancreas causes endoplasmic reticulum stress, acinar cell damage and increased susceptibility to pancreatitis.