Increased faecal serine protease activity in diarrhoeic IBS patients: a colonic lumenal factor impairing colonic permeability and sensitivity

Abstract

Elevated colonic lumenal serine protease activity of IBS-D patients evokes a PAR-2-mediated colonic epithelial barrier dysfunction and subsequent allodynia in mice, suggesting a novel organic background in the pathogenesis of IBS.

Review article: associations between immune activation, intestinal permeability and the irritable bowel syndrome

“…35 Alterations in the production of these pro-inflammatory cytokines (primarily produced by monocytes and macrophages) are suggestive of an increase in innate immune activity in IBS patients. Accordingly, data collected from D-IBS patients indicate an increase in protease activity in the stool 39 and jejunal fluid 40 and an increase in NO release in the rectal mucosa, 41 indicating the potential involvement of mast cells in the increased release of inflammatory mediators. This finding is consistent with data indicating an increase in blood levels of lipid inflammatory mediators such as prostaglandin E2 and leukotriene B4, which are known to be released from newly formed mast cells.…”

“…Two studies have reported a correlation between mast cell density and increased intestinal permeability in IBS patients. 39,71 Finally, several studies have correlated mast cell number with the severity of abdominal pain symptoms, 64,68,73,116 especially when mast cells were found close to enteric nerves. 68,73 Further investigation is required to determine the activation state of mast cells (e.g.…”

Blastocystis subtypes in irritable bowel syndrome and inflammatory bowel disease in Ankara, Turkey

“…Serine proteases become neurologically active at high levels, producing abdominal aches, muscular contractions and widespread pain. These high levels of serine proteases are not found in viral or bacterial enteritis (Gecse et al 2008). Proteases are produced by protozoa to degrade host immunological factors, such as IgA (Puthia et al 2005).…”

Epithelial Integrity Is Maintained by a Matriptase-Dependent Proteolytic Pathway

“…In particular, the specific contribution of extracellular serine proteases and their cognate inhibitors to epithelial tight junction formation, maintenance, and regulation of barrier function is unclear. [3][4][5][6]20,21 Matriptase is a trypsin-like transmembrane serine protease encoded by the ST14 gene that belongs to the recently emerged type II transmembrane serine protease family. Orthologs of matriptase have been found in all vertebrate species analyzed to date, and homologs of the type II transmembrane serine proteases are present in bees and fruit flies.…”