Intra-acinar trypsinogen activation mediates early stages of pancreatic injury but not inflammation in mice with acute pancreatitis.
Gastroenterology 2011;
141:2210-2217.e2. [PMID:
21875495 PMCID:
PMC3587766 DOI:
10.1053/j.gastro.2011.08.033]
[Citation(s) in RCA: 167] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Revised: 08/11/2011] [Accepted: 08/18/2011] [Indexed: 02/08/2023]
Abstract
BACKGROUND & AIMS
The role of trypsinogen activation in the pathogenesis of acute pancreatitis (AP) has not been clearly established.
METHODS
We generated and characterized mice lacking trypsinogen isoform 7 (T7) gene (T(-/-)). The effects of pathologic activation of trypsinogen were studied in these mice during induction of AP with cerulein. Acinar cell death, tissue damage, early intra-acinar activation of the transcription factor nuclear factor κB (NF-κB), and local and systemic inflammation were compared between T(-/-) and wild-type mice with AP.
RESULTS
Deletion of T7 reduced the total trypsinogen content by 60% but did not affect physiologic function. T(-/-) mice lacked pathologic activation of trypsinogen, which occurs within acinar cells during early stages of AP progression. Absence of trypsinogen activation in T(-/-) mice led to near complete inhibition of acinar cell death in vitro and a 50% reduction in acinar necrosis during AP progression. However, T(-/-) mice had similar degrees of local and systemic inflammation during AP progression and comparable levels of intra-acinar NF-κB activation, which was previously shown to occur concurrently with trypsinogen activation during early stages of pancreatitis.
CONCLUSIONS
T7 is activated during pathogenesis of AP in mice. Intra-acinar trypsinogen activation leads to acinar death during early stages of pancreatitis, which accounts for 50% of the pancreatic damage in AP. However, progression of local and systemic inflammation in AP does not require trypsinogen activation. NF-κB is activated early in acinar cells, independently of trypsinogen activation, and might be responsible for progression of AP.
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