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Chymotrypsin activity signals to intestinal epithelium by Protease-Activated Receptor-dependent mechanisms
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  • Simon Guignard,
  • Mahmoud Saifeddine,
  • Koichiro Mihara,
  • Majid Motahhary,
  • Magali Savignac,
  • Laura Guiraud,
  • David Sagnat,
  • mireille sebbag,
  • Sokchea Khou,
  • Corinne Rolland,
  • Barbara Bournet,
  • Louis Buscail,
  • Etienne Buscail,
  • Laurent Alric,
  • Caroline Camare,
  • Mouna Ambli,
  • Nathalie Vergnolle,
  • Morley Hollenberg,
  • Celine Deraison,
  • Chrystelle Bonnart
Simon Guignard
Inserm U1220
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Mahmoud Saifeddine
Uinversity of Calgary
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Koichiro Mihara
Uinversity of Calgary
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Majid Motahhary
Uinversity of Calgary
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Magali Savignac
Toulouse Institute for Infectious and Inflammatory Diseases (Infinity) INSERM UMR1291
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Laura Guiraud
Inserm U1220
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David Sagnat
Inserm U1220
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mireille sebbag
INSERM UMR 1220
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Sokchea Khou
Inserm U1220
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Corinne Rolland
INSERM
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Barbara Bournet
Gastroenterology department Toulouse university Hospital
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Louis Buscail
Gastroenterology department Toulouse university Hospital
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Etienne Buscail
Inserm U1220
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Laurent Alric
Toulouse University Department of Internal Medicine and Digestive Diseases, Rangueil, Toulouse 3 University Hospital, Toulouse, France.
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Caroline Camare
Toulouse University Hospitals, Department of Clinical Biochemistry, Toulouse, France
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Mouna Ambli
Inserm U1220
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Nathalie Vergnolle
Inserm U1220

Corresponding Author:[email protected]

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Morley Hollenberg
University of Calgary
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Celine Deraison
Inserm U1220
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Chrystelle Bonnart
Inserm U1220
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Abstract

Background and purpose Chymotrypsin is a serine protease produced by the pancreas and secreted into the lumen of the small intestine, where it digests food proteins. Due to its presence in the gut lumen, we hypothesized that chymotrypsin activity may be found close to epithelial cells and signals to them via Protease-activated receptors (PARs). We deciphered molecular pharmacology mechanisms for chymotrypsin signaling in intestinal epithelial cells. Experimental approaches The presence and activity of chymotrypsin were evaluated by western blot (WB) and enzymatic activity tests in luminal and mucosal compartments of murine and human gut samples. The ability of chymotrypsin to cleave the extracellular domain of PAR1 or PAR2 was assessed using cell lines expressing N-terminally-tagged receptors. The cleavage site of chymotrypsin on PAR1 and PAR2 was determined by HPLC-MS analysis. To study the pharmacology of chymotrypsin signals, we investigated calcium signaling and ERK1/2 activation using calcium mobilization assays and WB in CMT93 intestinal epithelial cells. Key results We found that chymotrypsin was present and active in the vicinity of the murine and human colonic epithelium. Molecular pharmacology studies evidenced that chymotrypsin cleaved both PARs receptors. While chymotrypsin activated calcium and ERK1/2 signaling pathways through PAR2, it disarmed PAR1, preventing further activation by its canonical agonist thrombin. CONCLUSION Our work suggests that the function of chymotrypsin in the gut lumen goes well beyond a simple digestive role. Our results highlight the ability of chymotrypsin to signal to intestinal epithelial cells via PARs, which may have important physiological consequences in gut homeostasis.
29 Jun 2023Submitted to British Journal of Pharmacology
29 Jun 2023Assigned to Editor
29 Jun 2023Submission Checks Completed
29 Jun 2023Review(s) Completed, Editorial Evaluation Pending
05 Jul 2023Reviewer(s) Assigned
18 Aug 2023Editorial Decision: Revise Minor