Acute pancreatitis, an inflammatory disease of the pancreas, causes death in over 30% of those with severe disease. Specific therapies to prevent pancreatitis or reduce injury are lacking. The disease usually originates in the pancreatic acinar cell after exposure to specific insults that cause pathologic acinar cell signaling. These changes in acinar cell signaling change the function of specific target proteins and cause organelle dysfunction. Among the most characteristic acinar cell early pancreatitis responses are intracellular activation of digestive enzymes (especially proteases) and inhibited secretion. Recent studies from Program investigators have also shown that there is decreased lysosomal function in acute pancreatitis. This Project will examine two recently characterized proteins (AP3 and D52) that can modulate zymogen activation, secretion, and may also affect autophagy and lysosomal function. We hypothesize that these two proteins regulate the biogenesis and trafficking of the minor secretory compartment (MSC), a pathway needed to form zymogen granules (ZG) from immature secretory granules (ISG). We posit that this compartment also regulates apical secretion and contributes to the normal function of the endo-lysosomal pathway. Finally, we propose a new model for zymogen activation at the onset of pancreatitis that begins with zymogen activation in the MSC then proceeds to decreased degradation of active enzymes by lysosomes.
Three Specific Aims relating to AP3 and D52 and its binding partner, Rab5, are planned: 1) Investigate their role in regulating physiologic secretion and membrane trafficking 2) Examine their expression and localization in pancreatitis models 3) Determine whether changing their expression levels affects pancreatitis responses. Finally, we will collaborate with other Projects to determine whether these molecules affect other pathways under study. Studies are planned using isolated mouse and human pancreatic acinar cells and in vivo mouse pancreatitis models. Our preliminary studies indicate that during pancreatitis, the levels of expression of these proteins change. Further, over-expression or deletion of these proteins by genetic or molecular means has dramatic effects on lysosomal protein trafficking, zymogen activation, and cell injury. Preliminary findings also suggest that the functions of AP3 and D52 may interact with pathways under study by other projects, such as Rab GTPases in Project 1, autophagic pathways in Project 3, and ER stress in Project 4. Extensive use of the Program's Animal and Pathology, Vector and Human Acinar, and Resource Management and Biostatistics Cores is planned.

Public Health Relevance

Project 2: Narrative Acute pancreatitis is an inflammatory disease of the pancreas that can cause death in 30% of those with severe disease. We have identified a new mechanism involving specific proteins that regulate trafficking in the pancreatic acinar cell and find that these can be manipulated to protect against pancreatitis. We will study these proteins to understand their role in health and disease with the goal of designing a therapy.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Program Projects (P01)
Project #
1P01DK098108-01A1
Application #
8743018
Study Section
Special Emphasis Panel (ZDK1)
Project Start
Project End
Budget Start
2014-09-01
Budget End
2015-06-30
Support Year
1
Fiscal Year
2014
Total Cost
Indirect Cost
Name
University of California Los Angeles
Department
Type
DUNS #
City
Los Angeles
State
CA
Country
United States
Zip Code
Waldron, Richard T; Su, Hsin-Yuan; Piplani, Honit et al. (2018) Ethanol Induced Disordering of Pancreatic Acinar Cell Endoplasmic Reticulum: An ER Stress/Defective Unfolded Protein Response Model. Cell Mol Gastroenterol Hepatol 5:479-497
Waldron, Richard T; Lugea, Aurelia; Gulla, Aiste et al. (2018) Proteomic Identification of Novel Plasma Biomarkers and Pathobiologic Pathways in Alcoholic Acute Pancreatitis. Front Physiol 9:1215
Buxbaum, James; Quezada, Michael; Chong, Bradford et al. (2018) The Pancreatitis Activity Scoring System predicts clinical outcomes in acute pancreatitis: findings from a prospective cohort study. Am J Gastroenterol 113:755-764
Zhao, Qinglan; Wei, Yi; Pandol, Stephen J et al. (2018) STING Signaling Promotes Inflammation in Experimental Acute Pancreatitis. Gastroenterology 154:1822-1835.e2
Biczo, Gyorgy; Vegh, Eszter T; Shalbueva, Natalia et al. (2018) Mitochondrial Dysfunction, Through Impaired Autophagy, Leads to Endoplasmic Reticulum Stress, Deregulated Lipid Metabolism, and Pancreatitis in Animal Models. Gastroenterology 154:689-703
Eibl, Guido; Cruz-Monserrate, Zobeida; Korc, Murray et al. (2018) Diabetes Mellitus and Obesity as Risk Factors for Pancreatic Cancer. J Acad Nutr Diet 118:555-567
Zheng, Han; You, Yang; Hua, Meiyun et al. (2018) Chlorophyllin Modulates Gut Microbiota and Inhibits Intestinal Inflammation to Ameliorate Hepatic Fibrosis in Mice. Front Physiol 9:1671
Lew, Daniel; Wu, Bechien U; Pandol, Stephen J et al. (2018) Disease Course Differences in Acute Pancreatitis Based on Etiology Using the Pancreatitis Activity Scoring System. Pancreas 47:e40-e41
Yuan, Jingzhen; Tan, Tanya; Geng, Meng et al. (2017) Novel Small Molecule Inhibitors of Protein Kinase D Suppress NF-kappaB Activation and Attenuate the Severity of Rat Cerulein Pancreatitis. Front Physiol 8:1014
Setiawan, Veronica Wendy; Monroe, Kristine R; Pandol, Stephen J (2017) Reply. Clin Gastroenterol Hepatol 15:1139

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