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.

Public Health Relevance

The present grant proposal investigates how mutations in the gene for the pancreatic digestive enzyme chymotrypsin C (CTRC) increase the risk for chronic pancreatitis, a progressive inflammatory disease of the pancreas. Results from this study can advance the development of novel diagnostic and therapeutic interventions for all forms of human pancreatitis.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
2R01DK082412-06
Application #
8627388
Study Section
Clinical, Integrative and Molecular Gastroenterology Study Section (CIMG)
Program Officer
Serrano, Jose
Project Start
2008-12-01
Project End
2018-03-31
Budget Start
2014-04-01
Budget End
2015-03-31
Support Year
6
Fiscal Year
2014
Total Cost
Indirect Cost
Name
Boston University
Department
Biochemistry
Type
Schools of Dentistry/Oral Hygn
DUNS #
City
Boston
State
MA
Country
United States
Zip Code
02118
Hegyi, Eszter; Sahin-Tóth, Miklós (2017) Genetic Risk in Chronic Pancreatitis: The Trypsin-Dependent Pathway. Dig Dis Sci 62:1692-1701
Wu, Hao; Zhou, Dai-Zhan; Berki, Dorottya et al. (2017) No significant enrichment of rare functionally defective CPA1 variants in a large Chinese idiopathic chronic pancreatitis cohort. Hum Mutat 38:959-963
Boros, Eszter; Szabó, András; Zboray, Katalin et al. (2017) Overlapping Specificity of Duplicated Human Pancreatic Elastase 3 Isoforms and Archetypal Porcine Elastase 1 Provides Clues to Evolution of Digestive Enzymes. J Biol Chem 292:2690-2702
Jancsó, Zsanett; Sahin-Tóth, Miklós (2016) Tighter Control by Chymotrypsin C (CTRC) Explains Lack of Association between Human Anionic Trypsinogen and Hereditary Pancreatitis. J Biol Chem 291:12897-905
Balázs, Anita; Németh, Balázs Csaba; Ördög, Balázs et al. (2016) A Common CCK-B Receptor Intronic Variant in Pancreatic Adenocarcinoma in a Hungarian Cohort. Pancreas 45:541-5
Párniczky, Andrea; Hegyi, Eszter; Tóth, Anna Zsófia et al. (2016) Genetic Analysis of Human Chymotrypsin-Like Elastases 3A and 3B (CELA3A and CELA3B) to Assess the Role of Complex Formation between Proelastases and Procarboxypeptidases in Chronic Pancreatitis. Int J Mol Sci 17:2148
Balázs, Anita; Hegyi, Péter; Sahin-Tóth, Miklós (2016) Pathogenic cellular role of the p.L104P human cationic trypsinogen variant in chronic pancreatitis. Am J Physiol Gastrointest Liver Physiol 310:G477-86
Szabó, András; Pilsak, Claudia; Bence, Melinda et al. (2016) Complex Formation of Human Proelastases with Procarboxypeptidases A1 and A2. J Biol Chem 291:17706-16
Derikx, Monique H M; Geisz, Andrea; Kereszturi, Éva et al. (2015) Functional significance of SPINK1 promoter variants in chronic pancreatitis. Am J Physiol Gastrointest Liver Physiol 308:G779-84
Szabó, András; Ludwig, Maren; Hegyi, Eszter et al. (2015) Mesotrypsin Signature Mutation in a Chymotrypsin C (CTRC) Variant Associated with Chronic Pancreatitis. J Biol Chem 290:17282-92

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