Molecular Mechanisms of Acute Pancreatitis

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DESCRIPTION (provided by applicant): Pancreatitis is an important clinical problem for which treatment is still largely supportive. We have identified the transcription factor NF-KappaB as a molecule that is activated early in the disease contributing to the initiation of an inflammatory cascade. Specific aim #1 is to determine the mechanisms and role of NF-KappaB activation in acute pancreatitis. We will extend our understanding of the significance of NF-KappaB activation by directly activating and inhibiting NF-KappaB within the pancreas using adenoviral expression of active and dominant negative subunits. We hypothesize that NF-KappaB plays a pro-inflammatory role and specifically drives expression of mob-1 and gro-alpha, two important chemokines. We will identify other genes activated by NF-KappaB within pancreatic acinar cells using a combination of adenovirus mediated delivery of an active subunit and oligonucleotide-directed microarray analysis. We will also test the hypothesis that trypsin activation is able to activate NF-KappaB within acinar cells using an adenoviral approach to directly active trypsin within acinar cells. Specific aim #2 is to identify the genes that are induced early in the course of acute pancreatitis. To further identify new molecules that are important in acute pancreatitis, we will utilize oligonucleotide directed microarrays to profile gene expression in rapid onset models of acute pancreatitis. We will specifically focus our search on genes for transcription factors and inflammatory mediators, as these may become targets of therapy for the disease. Specific aim #3 is to determine the mechanisms and role of the transcription factor EGR-1 in acute pancreatitis. Preliminary experiments have shown that the transcription factor EGR-1 is highly induced early in the course of caerulein induced acute pancreatitis. EGR-1 plays an important role in other inflammatory diseases and is a know regulator of tissue factor (TF). We will determine if this transcription factor is also induced in other models of acute pancreatitis, investigate the cellular mechanisms involved in its regulation, and determine the relationship between its activation and the severity of acute pancreatitis. We will also test the hypothesis that EGR-1 drives expression of TF in the pancreas, and identify other targets of this important transcription factor. Specific aim #4 is to determine the roles of pro-inflammatory effectors, mob-1, gro-alpha, TF and CGRP in acute pancreatitis. Of the pro-inflammatory molecules identified as up-regulated after treatment of animals with high concentrations of caerulein, we have selected these four as being especially likely to contribute to the severity of acute pancreatitis based upon their known functions in other diseases. Specifically, we will test the hypothesis that mob-1 and gro-alpha are important for chemoattraction of T-cells and neutrophils respectively, that TF is important for initiating blood coagulation in the pancreas, and that CGRP expression in acinar cells contributes to alterations in pancreatic and systemic blood flow.