High Fecal Proteolytic Activity That Precedes Ulcerative Colitis Likely Results From Impaired Inactivation of Pancreatic Proteases Rather Than Bacteria

2021 ◽  
Author(s):  
Xiaofa Qin
Keyword(s):  
Ulcerative Colitis ◽  
Proteolytic Activity ◽  
Pancreatic Proteases

scholarly journals A210 ADLERCREUTZIA IS DEPLETED IN UC PATIENTS, EVEN BEFORE CLINICAL DIAGNOSIS, AND INVERSELY CORRELATES WITH FECAL ELASTOLYTIC ACTIVITY

2020 ◽  
Vol 3 (Supplement_1) ◽  
pp. 82-83
Author(s):  
A Santiago Badenas ◽  
J Libertucci ◽  
W Turpin ◽  
H J Galipeau ◽  
K Croitoru ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
At Risk ◽  
Microbial Community ◽  
Proteolytic Activity ◽  
Clinical Diagnosis ◽  
Community Analysis ◽  
Microbial Community Analysis ◽  
Healthy Controls ◽  
Fecal Samples ◽  
Elastolytic Activity

Abstract Background A combination of genetics, environmental, and immune factors contribute to the development of ulcerative colitis (UC). Host proteolytic imbalance has been reported in active UC. Preliminary results from our lab suggest microbial proteolytic activity is increased before as well as after onset of UC, and transfer of this activity to mice contributes to inflammation. Aims Our aim was to correlate the elastolytic activity of fecal samples from individuals at risk for IBD, before and after onset of ulcerative colitis, with their fecal microbiota profiles Methods We first investigated proteolytic activity in fecal samples from individuals at risk to develop UC (pre-UC, n=12) prior to disease onset and after UC diagnosis (post-UC, n=7) and matched healthy controls (n=66). Microbial community analysis was performed by sequencing the V4 region of the 16S rRNA gene region using Illumina MiSeq platform. Sequences were analyzed with QIIMEv1.9.0. We measured bacterial proteolytic activity, using a FITC-elastin assay. Results Microbial community analysis revealed that the overall diversity (both richness and evenness) in UC patients was decreased compared to healthy controls as well as pre-UC patients. The relative abundance of the genus Adlercreutzia was decreased by 3.1 fold in pre-UC patients compared to healthy controls and was further decreased in post-UC (3.8 fold). The presence of Adlercreutzia was also found to be negatively correlated (r=-0.47, p<0.0001) with elastolytic activity in stool supernatant, suggesting a possible protective role in the disease. Conclusions We found novel potentially protective bacteria, Adlercreutzia, which was depleted in UC patients, even before clinical diagnosis and correlated negatively with proinflammatory elastolytic activity described previously in IBD. The protective mechanisms are under investigation. On behalf of the CCC-GEM Project consortiumand Supported by a CCC GIA to EFV Funding Agencies CCC

scholarly journals A35 MICROBIAL PROTEOLYTIC SIGNATURE IN ULCERATIVE COLITIS INDUCES AN INFLAMMATORY SIGNATURE IN MICROBIOTA-HUMANIZED MICE

2020 ◽  
Vol 3 (Supplement_1) ◽  
pp. 42-43
Author(s):  
H J Galipeau ◽  
W Turpin ◽  
A Caminero Fernandez ◽  
A Santiago ◽  
J Libertucci ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
At Risk ◽  
Proteolytic Activity ◽  
Intestinal Microbiota ◽  
Inflammatory Responses ◽  
Critical Role ◽  
Low Grade ◽  
Polymorphonuclear Cells ◽  
Fecal Samples ◽  
Patients At Risk

Abstract Background Altered gut microbiota composition has been associated with inflammatory bowel diseases (IBD) including ulcerative colitis (UC), but causality and bacterially-driven mechanisms, are unclear. Proteases within the gastrointestinal tract play a critical role in maintaining homeostasis and are tightly regulated by anti-proteases. Host-derived proteolytic imbalances have been described in IBD, including UC, however, the role of intestinal microbiota as a source of proteases and anti-proteases has largely been ignored. Aims To study microbial proteolytic activity and intestinal microbiota profiles in a cohort of individuals at-risk for IBD, and in those individuals that develop UC at follow-up. Methods Fecal samples were collected from healthy individuals at-risk for IBD and who went on to develop UC (pre-UC; n=14) and again after UC diagnosis (post-UC, n=10). Fecal samples from matched at-risk individuals that did not develop UC were used as healthy controls (n=52). Overall fecal proteolytic and elastolytic activity was measured. We performed metagenomics sequencing in 4 UC subjects (pre and post) and 4 matched HC using Illumina Hi-Seq from stool DNA. To investigate bacterial origin and functional significance, pregnant germ-free (GF) mice were colonized with a fecal sample from a selected UC subject (pre and post) and a matched HC. Naturally colonized litters were followed for 12 weeks, after which proteolytic activities and signs of inflammation were measured. Results Fecal proteolytic and elastase activity was increased in pre- and post-UC samples compared to HCs. Metagenomics revealed over 20k genes were significantly different between HC and pre-UC samples, and of these, 440 related to proteases and peptidases. Increased fecal proteolytic activity, higher lipocalin levels, and increased colonic polymorphonuclear cells in colonic H&E sections was observed in pre- and post-UC colonized mice compared to HC colonized mice. Mice colonized with pre-UC microbiota showed increased mRNA expression of genes linked to immunological disease, antimicrobial and inflammatory responses (ie. Tlr2, Tlr5, Nod2, and Il1b) as compared to HC colonized mice. Conclusions These results suggest increased fecal proteolytic activity is observed prior to the onset and clinical diagnosis of UC in patients at-risk for IBD, and upon transfer to mice born from colonized GF dams, low-grade inflammation develops. These pathways could be developed as novel non-invasive biomarkers to monitor at-risk populations. Submitted on behalf of the CCC-GEM Project consortium. Supported by CCC GIA to EF Verdu Funding Agencies CCC

scholarly journals A29 NOVEL FECAL BIOMARKERS THAT PRECEDE CLINICAL DIAGNOSIS OF ULCERATIVE COLITIS

2021 ◽  
Vol 4 (Supplement_1) ◽  
pp. 268-269
Author(s):  
H J Galipeau ◽  
A CAMINERO FERNANDEZ ◽  
W Turpin ◽  
M Bermudez-Brito ◽  
A Santiago ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
At Risk ◽  
Gut Microbiota ◽  
Proteolytic Activity ◽  
Clinical Diagnosis ◽  
Elastase Activity ◽  
Microbial Composition ◽  
Fecal Samples ◽  
And Function

Abstract Background Altered gut microbiota composition and function has been associated with inflammatory bowel diseases (IBD) including ulcerative colitis (UC), but causality and mechanisms remain unknown. Most studies have examined patients with active or treated disease and little is known about microbial compositional or functional changes that occur before disease onset. Aims We studied a longitudinal cohort of subjects at risk for IBD to define the fecal microbial composition and function in subjects prior to UC onset (pre-UC) and at diagnosis (post-UC), and in matched at-risk subjects that remained healthy. Methods Fecal samples were collected from healthy individuals at-risk for IBD (pre-UC; n=13) and subjects were followed longitudinally until UC diagnosis (post-UC, n=9), at which point another fecal sample was collected. Fecal samples from a cohort of matched at-risk individuals that did not develop UC were used as healthy controls (n=48). We applied 16S rRNA gene sequencing, next generation shotgun sequencing, in vitro proteolytic assays and gnotobiotic colonizations to define the microbial composition and proteolytic function in fecal samples. Results The microbiota of post-UC subjects clustered separately from pre-UC and HC subjects, based on bray-curtis and unweighted UniFrac, had reduced alpha-diversity, and had reduced abundance of Aldercreutzia compared to pre-UC and HC. In vitro functional analysis revealed increased fecal proteolytic and elastase activity in pre-UC and post-UC samples compared to HC. Metagenomics identified pathways and gene families related to protein metabolism and proteases/peptides that were significantly different between HC and pre-UC samples, suggesting a bacterial component to the pre-UC proteolytic signature. Elastase activity inversely correlated with the relative abundance of Adlercreutzia, and other potentially beneficial taxa, and directly correlated with Bacteroides vulgatus, a known proteolytic taxon. High elastase activity was confirmed in Bacteroides isolates from fecal samples. Bacterial contribution and functional significance of the proteolytic signature was investigated in germ-free adults and litters born from dams colonized with HC, pre-UC or post-UC microbiota. Mice colonized with pre-UC microbiota at adulthood or neonatally developed higher fecal proteolytic activity and an inflammatory immune tone compared with HC colonized mice. Conclusions We have identified increased fecal proteolytic activity that precedes clinical diagnosis of UC and associates with gut microbiota changes. This may constitute a non-invasive biomarker of inflammation to monitor at-risk populations that can be targeted therapeutically with anti-proteases. Funding Agencies CAG, CCC, CIHR

Sem Observations in Gastric Mucosa Exposed to Progressive Enzymatic Etching

1980 ◽  
Vol 38 ◽  
pp. 570-571
Author(s):  
C.A.E. Lemmi ◽  
D. Booth ◽  
G.E. Adomian
Keyword(s):  
Gastric Mucosa ◽  
Critical Point ◽  
Proteolytic Activity ◽  
Etching Process ◽  
Cellular Types

In order to enrich populations of homogeneous cellular types we dissociated gastric mucosa by enzymatic techniques. In addition, we used SEM to monitor the progressive etching of the mucosa. Two enzymes were tested: collagenase III with minimum proteolytic activity and Pronase with broader proteolytic effects. The gastric mucosa was exposed to the effect of the enzymes using everted stomach preparations. In this way the digestive action occured progressively from the lumen of the stomach toward the base of the glands. This “etching” process could be monitored conveniently by SEM. After incubation for periods varying from 30 to 210 minutes the tissues were stretched on dental wax, fixed in 2 % glutaralheyde, post-fixed in osmium, dehydrated, critical point dryed and coated with gold. A model MSM-5 “Mini-SEM” was used for observation. Gentle uncurling of the preparation before coating with gold produced fractures which revealed the structure of the gastric glandsin more detail.

Mannan-binding lectin gene polymorphisms in ulcerative colitis and Crohn's disease

2001 ◽  
Vol 120 (5) ◽  
pp. A459-A459
Author(s):  
A RECTOR ◽  
P LEMEY ◽  
W LAFFUT ◽  
E KEYAERTS ◽  
F STRUYF ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Gene Polymorphisms ◽  
Lectin Gene ◽  
Mannan Binding Lectin ◽  
Binding Lectin
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