Shoko Edogawa 1 , Adam L Edwinson 1 , Stephanie A Peters 1 , Lakshmikanth L Chikkamenahalli 1 , Wendy Sundt 1 , Sara Graves 1 , Sakteesh V Gurunathan 1 , Margaret Breen-Lyles 1 , Stephen Johnson 2 , Roy Dyer 3 , Rondell Graham 4 , Jun Chen 5 , Purna Kashyap 1 , Gianrico Farrugia 1 , Madhusudan Grover 1 Show Affiliations »
Abstract
OBJECTIVE: The intestinal lumen contains several proteases. Our aim was to determine the role of faecal proteases in mediating barrier dysfunction and symptoms in IBS. DESIGN: 39 patients with IBS and 25 healthy volunteers completed questionnaires, assessments of in vivo permeability, ex vivo colonic barrier function in Ussing chambers, tight junction (TJ) proteins, ultrastructural morphology and 16 s sequencing of faecal microbiota rRNA. A casein-based assay was used to measure proteolytic activity (PA) in faecal supernatants (FSNs). Colonic barrier function was determined in mice (ex-germ free) humanised with microbial communities associated with different human PA states. RESULTS: Patients with IBS had higher faecal PA than healthy volunteers. 8/20 postinfection IBS (PI-IBS) and 3/19 constipation- predominant IBS had high PA (>95th percentile). High-PA patients had more and looser bowel movements, greater symptom severity and higher in vivo and ex vivo colonic permeability. High-PA FSNs increased paracellular permeability, decreased occludin and increased phosphorylated myosin light chain (pMLC) expression. Serine but not cysteine protease inhibitor significantly blocked high-PA FSN effects on barrier. The effects on barrier were diminished by pharmacological or siRNA inhibition of protease activated receptor-2 (PAR-2). Patients with high-PA IBS had lower occludin expression, wider TJs on biopsies and reduced microbial diversity than patients with low PA. Mice humanised with high-PA IBS microbiota had greater in vivo permeability than those with low-PA microbiota. CONCLUSION: A subset of patients with IBS, especially in PI-IBS, has substantially high faecal PA, greater symptoms, impaired barrier and reduced microbial diversity. Commensal microbiota affects luminal PA that can influence host barrier function. © Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.
OBJECTIVE: The intestinal lumen contains several proteases. Our aim was to determine the role of faecal proteases in mediating barrier dysfunction and symptoms in IBS. DESIGN: 39 patients with IBS and 25 healthy volunteers completed questionnaires, assessments of in vivo permeability, ex vivo colonic barrier function in Ussing chambers, tight junction (TJ) proteins, ultrastructural morphology and 16 s sequencing of faecal microbiota rRNA. A casein-based assay was used to measure proteolytic activity (PA) in faecal supernatants (FSNs). Colonic barrier function was determined in mice (ex-germ free) human ised with microbial communities associated with different human PA states. RESULTS: Patients with IBS had higher faecal PA than healthy volunteers. 8/20 postinfection IBS (PI-IBS) and 3/19 constipation - predominant IBS had high PA (>95th percentile). High-PA patients had more and looser bowel movements , greater symptom severity and higher in vivo and ex vivo colonic permeability. High-PA FSNs increased par acellular permeability, decreased occludin and increased phosphorylated myosin light chain (pMLC ) expression. Serine but not cysteine protease inhibitor significantly blocked high-PA FSN effects on barrier. The effects on barrier were diminished by pharmacological or siRNA inhibition of protease activated receptor-2 (PAR-2 ). Patients with high-PA IBS had lower occludin expression, wider TJs on biopsies and reduced microbial diversity than patients with low PA. Mice human ised with high-PA IBS microbiota had greater in vivo permeability than those with low-PA microbiota. CONCLUSION: A subset of patients with IBS, especially in PI-IBS, has substantially high faecal PA, greater symptoms, impaired barrier and reduced microbial diversity. Commensal microbiota affects luminal PA that can influence host barrier function. © Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.
Entities: CellLine
Chemical
Disease
Gene
Species
Keywords:
zzm321990Campylobacterzzm321990; gastroenteritis; germ-free mice; microbiome; trypsin
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Year: 2019
PMID： 30923071 PMCID： PMC6765451 DOI： 10.1136/gutjnl-2018-317416
Source DB: PubMed Journal: Gut ISSN： 0017-5749 Impact factor: 23.059