Role for protease activity in visceral pain in irritable bowel syndrome.
Mediators involved in the generation of symptoms in patients with irritable bowel syndrome (IBS) are poorly understood. Here we show that colonic biopsy samples from IBS patients release increased levels of proteolytic activity (arginine cleavage) compared to asymptomatic controls. This was dependent on the activation of NF-kappaB. In addition, increased proteolytic activity was measured in vivo, in colonic washes from IBS compared with control patients. Trypsin and tryptase expression and release were increased in colonic biopsies from IBS patients compared with control subjects. Biopsies from IBS patients (but not controls) released mediators that sensitized murine sensory neurons in culture. Sensitization was prevented by a serine protease inhibitor and was absent in neurons lacking functional protease-activated receptor-2 (PAR2). Supernatants from colonic biopsies of IBS patients, but not controls, also caused somatic and visceral hyperalgesia and allodynia in mice, when administered into the colon. These pronociceptive effects were inhibited by serine protease inhibitors and a PAR2 antagonist and were absent in PAR2-deficient mice. Our study establishes that proteases are released in IBS and that they can directly stimulate sensory neurons and generate hypersensitivity symptoms through the activation of PAR2.
Cenac
Nicolas
N
Department of Pharmacology and Therapeutics, University of Calgary, Calgary, Alberta, Canada.
Andrews
Christopher N
CN
Holzhausen
Marinella
M
Chapman
Kevin
K
Cottrell
Graeme
G
Andrade-Gordon
Patricia
P
Steinhoff
Martin
M
Barbara
Giovanni
G
Beck
Paul
P
Bunnett
Nigel W
NW
Sharkey
Keith A
KA
Ferraz
Jose Geraldo P
JG
Shaffer
Eldon
E
Vergnolle
Nathalie
N
D015746:Abdominal Pain / Q000201:enzymology* / Q000209:etiology; D000328:Adult; D003106:Colon / Q000201:enzymology / Q000294:innervation / Q000473:pathology; D010450:Endopeptidases / Q000032:analysis / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006801:Humans; D006930:Hyperalgesia / Q000201:enzymology* / Q000209:etiology; D043183:Irritable Bowel Syndrome / Q000150:complications* / Q000201:enzymology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D016328:NF-kappa B / Q000378:metabolism; D009475:Neurons, Afferent / Q000187:drug effects / Q000378:metabolism*; D044464:Receptor, PAR-2 / Q000819:agonists; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology; D014357:Trypsin / Q000032:analysis / Q000187:drug effects / Q000378:metabolism; D053802:Tryptases / Q000032:analysis / Q000037:antagonists & inhibitors / Q000378:metabolism; D000515:alpha 1-Antitrypsin / Q000032:analysis / Q000378:metabolism
D016328:NF-kappa B; D044464:Receptor, PAR-2; C043392:SERPINA1 protein, human; D015842:Serine Proteinase Inhibitors; D000515:alpha 1-Antitrypsin; D010450:Endopeptidases; D014357:Trypsin; D053802:Tryptases