The specific objectives of the present grant proposal are to determine the role of chymotrypsin C (CTRC) in the regulation of digestive enzyme activation and degradation and to investigate the mechanism(s) by which CTRC mutants act as risk factors for chronic pancreatitis in humans. This project forms a part of a broad, long-term research program on the molecular pathomechanism of genetic risk factors associated with human chronic pancreatitis. The studies combine biochemical and cell biological approaches with data obtained from human genetic association studies to formulate a molecular disease model that underlies chronic pancreatitis. According to our working hypothesis chymotrypsin C is an essential regulator of digestive enzyme activation and degradation and mutation-induced defects in this regulatory function predisposes to chronic pancreatitis. An alternative hypothesis will be also explored, which suggests that intracellular misfolding of CTRC mutants would elicit endoplasmic reticulum stress;induce the unfolded protein response and trigger the inflammatory process through activation of nuclear factor ?B. Thus, a direct link might be established between mutations in the CTRC gene and pancreatic inflammation.

Public Health Relevance

The present grant proposal intends to characterize a novel genetic risk factor for chronic pancreatitis, an often debilitating and potentially fatal human disease. We wish to find out why mutations in the digestive enzyme chymotrypsin C can increase the risk of chronic pancreatitis in humans. The results can advance the development of novel diagnostic and therapeutic interventions for human pancreatitis.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK082412-05
Application #
8447568
Study Section
Clinical and Integrative Gastrointestinal Pathobiology Study Section (CIGP)
Program Officer
Serrano, Jose
Project Start
2009-04-01
Project End
2014-03-31
Budget Start
2013-04-01
Budget End
2014-03-31
Support Year
5
Fiscal Year
2013
Total Cost
$334,280
Indirect Cost
$128,569
Name
Boston University
Department
Biochemistry
Type
Schools of Dentistry
DUNS #
604483045
City
Boston
State
MA
Country
United States
Zip Code
02118
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
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
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
Szabó, András; Xiao, Xunjun; Haughney, Margaret et al. (2015) A novel mutation in PNLIP causes pancreatic triglyceride lipase deficiency through protein misfolding. Biochim Biophys Acta 1852:1372-9
Rygiel, Agnieszka Magdalena; Beer, Sebastian; Simon, Peter et al. (2015) Gene conversion between cationic trypsinogen (PRSS1) and the pseudogene trypsinogen 6 (PRSS3P2) in patients with chronic pancreatitis. Hum Mutat 36:350-6
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
Nakano, Eriko; Geisz, Andrea; Masamune, Atsushi et al. (2015) Variants in pancreatic carboxypeptidase genes CPA2 and CPB1 are not associated with chronic pancreatitis. Am J Physiol Gastrointest Liver Physiol 309:G688-94
Szabó, András; Radisky, Evette S; Sahin-Tóth, Miklós (2014) Zymogen activation confers thermodynamic stability on a key peptide bond and protects human cationic trypsin from degradation. J Biol Chem 289:4753-61
Beer, Sebastian; Sahin-Toth, Miklos (2014) Exonic variants affecting pre-mRNA splicing add to genetic burden in chronic pancreatitis. Gut 63:860-1

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