Project description:The mechanisms behind acute mucosal injury responses in humans are poorly investigated.We thus examined the acute responses to mucosal barrier injury in humans with and without UC. A standardized mucosal wound extending to the muscularis mucosa layer was inflicted in the sigmoid colon of 6 patients with quiescent UC and 6 control subjects. Macroscopic, microscopic and molecular injury responses were assessed at 24 and 48 hours by repeated high resolution imaging and collection of biopsies across the wounds which were assessed by RNA sequencing.
Project description:Transcriptional profiling of microscopically laser dissected murine colonic tissue from 3 separate normal crypts, wound associated epithelium (WAE), normal epithelium, and regenerating crypts (day 6 only) at days 2,4,and 6 after colonic mucosal injury. Injury model performed as described in: H. Seno et al., Efficient colonic mucosal wound repair requires Trem2 signaling. Proc. Natl. Acad. Sci. USA 106, 256-261 (2009)
Project description:Poly(ADP-ribose) polymerases (PARPs) synthesize and bind branched polymers of ADP-ribose to acceptor proteins using NAD as a substrate, and participate to the control of gene transcription and DNA repair. PARP1, the most abundant isoform, regulates the expression of proinflammatory mediator - cytokines, chemokines and adhesion molecules, and inhibition of PARP1 enzymatic activity reduced or ameliorated autoimmune diseases in several experimental models, including colitis. However, the mechanism(s) underlying the protective effects of PARP1 inhibition in colitis and the cell types in which Parp1 deletion has the most significant impact are unknown. The objective of the current study was to determine the impact of Parp1 deletion on the innate immune response to mucosal injury. Genome-wide analysis of the colonic transcriptome was performed. Compared to WT, we demonstrated that Parp1-/-were protected from DSS-induced colitis and that this protection was associated with a dramatic transcriptional reprogramming in the colon. WT or Parp1-/- mice were treated with drinking water administered ad libitum without ot with 4% dextran sulfate (DSS) for seven days. Whole colon was collected for RNA extraction and hybridization on Affymetrix microarrays. Thee mice from each genotype/treatment groups were used in the analysis.
Project description:Poly(ADP-ribose) polymerases (PARPs) synthesize and bind branched polymers of ADP-ribose to acceptor proteins using NAD as a substrate, and participate to the control of gene transcription and DNA repair. PARP1, the most abundant isoform, regulates the expression of proinflammatory mediator - cytokines, chemokines and adhesion molecules, and inhibition of PARP1 enzymatic activity reduced or ameliorated autoimmune diseases in several experimental models, including colitis. However, the mechanism(s) underlying the protective effects of PARP1 inhibition in colitis and the cell types in which Parp1 deletion has the most significant impact are unknown. The objective of the current study was to determine the impact of Parp1 deletion on the innate immune response to mucosal injury. Genome-wide analysis of the colonic transcriptome was performed. Compared to WT, we demonstrated that Parp1-/-were protected from DSS-induced colitis and that this protection was associated with a dramatic transcriptional reprogramming in the colon.
Project description:Leber2015 - Mucosal immunity and gut
microbiome interaction during C. difficile infection
This model is described in the article:
Systems Modeling of
Interactions between Mucosal Immunity and the Gut Microbiome
during Clostridium difficile Infection.
Leber A, Viladomiu M, Hontecillas R,
Abedi V, Philipson C, Hoops S, Howard B, Bassaganya-Riera
J.
PLoS ONE 2015; 10(7): e0134849
Abstract:
Clostridium difficile infections are associated with the use
of broad-spectrum antibiotics and result in an exuberant
inflammatory response, leading to nosocomial diarrhea, colitis
and even death. To better understand the dynamics of mucosal
immunity during C. difficile infection from initiation through
expansion to resolution, we built a computational model of the
mucosal immune response to the bacterium. The model was
calibrated using data from a mouse model of C. difficile
infection. The model demonstrates a crucial role of T helper 17
(Th17) effector responses in the colonic lamina propria and
luminal commensal bacteria populations in the clearance of C.
difficile and colonic pathology, whereas regulatory T (Treg)
cells responses are associated with the recovery phase. In
addition, the production of anti-microbial peptides by inflamed
epithelial cells and activated neutrophils in response to C.
difficile infection inhibit the re-growth of beneficial
commensal bacterial species. Computational simulations suggest
that the removal of neutrophil and epithelial cell derived
anti-microbial inhibitions, separately and together, on
commensal bacterial regrowth promote recovery and minimize
colonic inflammatory pathology. Simulation results predict a
decrease in colonic inflammatory markers, such as neutrophilic
influx and Th17 cells in the colonic lamina propria, and length
of infection with accelerated commensal bacteria re-growth
through altered anti-microbial inhibition. Computational
modeling provides novel insights on the therapeutic value of
repopulating the colonic microbiome and inducing regulatory
mucosal immune responses during C. difficile infection. Thus,
modeling mucosal immunity-gut microbiota interactions has the
potential to guide the development of targeted fecal
transplantation therapies in the context of precision medicine
interventions.
This model is hosted on
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and identified by:
BIOMD0000000583.
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To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
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Project description:Background & Aims: Genome-wide gene expression (GWGE) profiles of mucosal colonic biopsies have suggested the existence of a continuous inflammatory state in quiescent ulcerative colitis (UC). The aim of this study was to use DNA microarray-based GWGE profiling of mucosal colonic biopsies and isolated colonocytes from UC patients and controls in order to identify the cell types responsible for the continuous inflammatory state. Methods: Adjacent mucosal colonic biopsies were obtained endoscopically from the descending colon in patients with active UC (n=8), quiescent UC (n=9), and with irritable bowel syndrome (controls, n=10). After isolation of colonocytes and subsequent extraction of total RNA, GWGE data were acquired using Human Genome U133 Plus 2.0 GeneChip Array (Affymetrix, Santa Clara, CA). Data analysis was carried out by principal component analysis and projection to latent structure-discriminant analysis using the SIMCA-P11 software (Umetrics, Umeå, Sweden). Results: A clear separation between active UC, quiescent UC and control biopsies were found, whereas the model for the colonocytes was unable to distinguish between quiescent UC and controls. The differentiation between quiescent UC and control biopsies was governed by unique profiles containing gene expressions with significant fold changes. These primarily belonged to the family of homeostatic chemokines revealing a plausible explanation to the abnormal regulated innate immune response seen in patients with UC. Conclusion: This study has demonstrated the presence of a continuous inflammatory state in quiescent UC, which seems to reflect an altered gene expression profile of lamina propria cells. Keywords: Colonocytes, continuous inflammation, mucosal colonic biopsies, gene expression profiles Adjacent mucosal colonic biopsies were attained endoscopically from the descending colon in patients with active UC (n=8), quiescent UC (n=9), and in controls (n=10). After extraction of total RNA, genome-wide gene expression data were acquired using Human Genome U133 Plus 2.0 GeneChip Array (Affymetrix, Santa Clara, CA). Amplification was required to obtain sufficient amounts of labelled complementary RNA (cRNA) target for analysis with arrays. Data analysis was carried out by principal component analysis and projection to latent structure-discriminant analysis using the SIMCA-P11 software (Umetrics, Umeå, Sweden).
Project description:Comparison of murine colonic mucosal gene expression between postanatal day 90 (P90) to postnatal day 30 (P30) by whole genomic expression microarray. Gene expression profiling of colonic mucosal DNA between P90 and P30 mice. Agilent Technologies two-color labelling kit and genomic hybridization protocol was utilized.
Project description:Citrobacter rodentium is commonly used to elucidate mucosal responses to infection in mice developing mild disease (e.g. C57BL/6), while little is known about host responses to infection in mice developing severe disease (e.g. C3H/HeN). We report that the phyla Bacteroidetes is a minor component of the tissue-associated microbiome in uninfected C3H/HeN mice. Following infection, C. rodentium rapidly and uniformly colonises the C3H/HeN colonic mucosa, which coincides with downregulation of proteins involved in the TCA cycle and oxidative phosphorylation in intestinal epithelial cells (IECs). In contrast, we observed upregulation of DNA replication and DNA damage repair processes, as well as cholesterol biogenesis, import and export, nutritional immunity, IL-22 and INFg responses, and expression of NLRP3, in IECs. Moreover, C. rodentium triggers a staggered cell proliferation response from 3 days post infection, which correlated with a higher abundance of SLC5A9 and reduced abundance of the IEC differentiation markers SLC26A3 and CA4. Uniquely, C. rodentium triggers differential secretion of gel-forming mucins, with the number of goblet cells filled with acidic and neutral mucins dramatically increasing and decreasing, respectively. Together, these results show that despite vigorous responses, C3H/HeN mice succumb to C. rodentium infection, possibly as a result of excessive and disordered mucosal responses.
Project description:Background & Aims: Genome-wide gene expression (GWGE) profiles of mucosal colonic biopsies have suggested the existence of a continuous inflammatory state in quiescent ulcerative colitis (UC). The aim of this study was to use DNA microarray-based GWGE profiling of mucosal colonic biopsies and isolated colonocytes from UC patients and controls in order to identify the cell types responsible for the continuous inflammatory state. Methods: Adjacent mucosal colonic biopsies were obtained endoscopically from the descending colon in patients with active UC (n=8), quiescent UC (n=9), and with irritable bowel syndrome (controls, n=10). After isolation of colonocytes and subsequent extraction of total RNA, GWGE data were acquired using Human Genome U133 Plus 2.0 GeneChip Array (Affymetrix, Santa Clara, CA). Data analysis was carried out by principal component analysis and projection to latent structure-discriminant analysis using the SIMCA-P11 software (Umetrics, Umeå, Sweden). Results: A clear separation between active UC, quiescent UC and control biopsies were found, whereas the model for the colonocytes was unable to distinguish between quiescent UC and controls. The differentiation between quiescent UC and control biopsies was governed by unique profiles containing gene expressions with significant fold changes. These primarily belonged to the family of homeostatic chemokines revealing a plausible explanation to the abnormal regulated innate immune response seen in patients with UC. Conclusion: This study has demonstrated the presence of a continuous inflammatory state in quiescent UC, which seems to reflect an altered gene expression profile of lamina propria cells. Keywords: Colonocytes, continuous inflammation, mucosal colonic biopsies, gene expression profiles
Project description:Purpose: to characterise the steady state gene expression and transcriptomic characteristic of tissue residernt human colonic mucosal gd T cells from controls undergoing routine colonoscopy.