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M1166 PepT1 Associated with Lipid Rafts Modulates Bacterial-Epithelial Interactions
years, p=0.03) and a shorter disease duration (5.6 years vs. 8.6 years, p=0.04) than those who had not required colectomy. Seven colectomies were at the time of or within 1 year of diagnosis, a further 3 colectomies were within 2 years. Colectomy patients were significantly more likely to have been on infliximab therapy (51.8% vs. 22.4%, p=0.001) but no more likely to have been on immunomodulator therapy (74.1% vs. 59.4%, p=0.14). Patients who required medical hospitalization for UC were more likely to require future colectomy (20.4% vs. 4.2%, p <0.001) than those who had not required hospitalization. On multivariate analysis after adjusting for age of onset, extent and duration of disease, immunomodulator or biologic therapy, and smoking history, the only significant variables predictive of future colectomy were requiring medical hospitalization for management of UC (OR 5.37, 95% CI 2.00 - 14.46) and ever requiring infliximab therapy (OR 3.12, 95% CI 1.21 - 8.07). Conclusion: Requiring medical hospitalization predicts future need for colectomy in UC patients. This data implies that prevention of clinical deterioration requiring hospitalization is an important goal in UC medical management. Aggressive medical management with biologic and immunomodulator therapy may help decrease the likelihood of needing colectomy.
AGA Abstracts
joints. Future cohort and controlled studies are mandated to further evaluate the relationship between IBD and osteonecrosis. Results
M1165 Bacterial Effector Avra Stabilizes Cell Tight Junctions to Inhibit Inflammation in Intestinal Epithelial Cells Anne P. Liao, Elaine O. Petrof, Sumalatha Kuppireddi, Erika C. Claud, Jun Sun The type III secretory system (TTSS) is a protein transport device using by Gram-negative pathogenic bacteria, including Salmonella, enteropathogenic Escherichia coli, enterohaemorrhagic E. coli, or Pseudomonas spp. The TTSS allows bacteria to inject virulence proteins, called effectors, into the cytosol of their eukaryotic host cells. These effectors are responsible for the alteration of tight junction (TJ) structure and function in intestinal epithelial cells. AvrA is a newly described bacterial effector found in Salmonella and E. coli. We report here that AvrA expression stabilizes cell permeability/tight junctions in intestinal epithelial cells. Cells colonized with an AvrA-deficient bacterial strain (AvrA-) had decrease of cell permeability, disruption of TJs, and increased inflammatory response. In contrast, cells colonized with AvrA-sufficient bacteria maintained cell permeability and stabilized TJ structure. The transelectrical resistance decreased and this occurred after AvrA- colonization for only 30 min. Western blot data showed that TJ proteins, such as ZO-1, claudin, decreased after AvrA- colonization for only I hour, and this decrease lasted for over 24 hours. This difference was confirmed In Vivo. Fluorescent tracer showed that increased fluorescence was found in the blood of mice infected with AvrA- compared to those infected with the AvrA sufficient strains. AvrA- disrupted TJ structure and function and increased inflammation In Vivo, compared to the AvrA sufficient strain. Our data further demonstrate that the TJ disruption is regulated directly by AvrA rather than indirectly through inflammatory cytokine regulation. An intriguing aspect of this study is that AvrA stabilized the TJs, even though the other TTSS proteins, SopB, SopE, SopE2, and SpiA, are known to disrupt TJs. This is consistent with other studies demonstrating a different role of AvrA in eliciting fluid accumulation compared to the other effector proteins such as sopA, sopB, sopD, or sopE2. We have also previously shown that AvrA attenuates the key proinflammatory NF-κB transcription factor, activate the β-catenin transcription factor, and inhibit cell apoptosis in mouse epithelial cells. Thus, AvrA may play a role as an anti-inflammatory protein to stabilize TJs and prevent cell death, and balance the opposing action of other bacterial effectors. Our findings indicate an important role for the bacterial effector AvrA in regulating on TJs of intestinal epithelial cells during inflammation. The role of AvrA represents a highly refined bacterial strategy that helps the bacteria survive in the host and dampen inflammatory response.
M1163 Depression in Inflammatory Bowel Disease Patients Katja Grubelic Ravic, Zeljko Krznaric, Silvija Cukovic-Cavka, Marko Brinar, Marina Grubic, Boris N. Vucelic Psychological disorders are highly prevalent in patients with inflammatory bowel disease (IBD). Depression may influence the clinical course of IBD and affect patient's quality of life. Objective. To determine the prevalence of depression in patient with IBD and the correlation between depression , patients age, disease duration and number of hospitalizations. Methods. 157 IBD patients from tertiary referral centre( 91 with Crohn's disease (CD), 62 with ulcerrative colitis (UC) and 3 unspecified ) completed the Zung Self-rating Depression Scale (SDS). The mean age of patients was 40 yr (15 - 69), and the mean duration of disease were 11,64 yr (1-40), the mean of number of hospitalization was 6,85 (0 - 30). Results. The mean SDS scores for the entire group were 43,43 (st.dev. 11.17) and the percentage of subjects with depression is 51,6%. There is no differences bettween patients with CD and those with UC in depression scores. There is no statistically significant correlation neither between patients age and depression scores nor between duration of illness and depression scores. Though, significant correlation has been found between depression and number of hospitalization. Conclusion. The patients with IBD have high rate of depression, independently to their age and disease duration. Patients who experience more hospitalizations score higher on depression scale. It is important for clinicians to assess depression among patients with IBD and recommend psychological treatment.
M1166 PepT1 Associated with Lipid Rafts Modulates Bacterial-Epithelial Interactions Hang Thi Thu Nguyen, Guillaume Dalmasso, Shanthi V. Sitaraman, Didier Merlin Background and Aims: PepT1 is a di/tripeptide transporter normally expressed in the small intestine and induced in colon under inflammatory conditions such as inflammatory bowel disease. We previously showed the localization of PepT1 in lipid rafts (LR) of epithelial cells. Our aim was to investigate the role of PepT1associated with LR in inflamed colonic epithelial cells. Methods: human colonic epithelial HT29-Cl.19A cells, which do not express human PepT1 (hPepT1) under normal conditions, were infected with enteropathogenic E. coli (EPEC). hPepT1 promoter activity was determined by luciferase assay. hPepT1 expression was assessed by RT-PCR, Western blot and immunofluorescence staining. hPepT1 transport activity was measured by uptake experiments. The presence of hPepT1 in LR fractions prepared from EPEC-infected HT29-Cl.19A cells was determined by Western blot analysis. HT29-Cl.19A cells stably transfected with wild type hPepT1 (HT29-Cl.19A/hPepT1) or its mutated forms that were not found in LR were examined for EPEC-induced expression of pro-inflammatory cytokine IL8 by real time RT-PCR and ELISA. Results: EPEC induced hPepT1 promoter activity, mRNA and protein expression and transport activity in HT29Cl.19A cells. Furthermore, hPepT1 co-localized with LR marker GM1 in EPEC-infected HT29-Cl.19A cells indicating its association with LR. Remarkably, expression of PepT1 in LR resulted in reduced EPEC attachment on HT29-Cl.19A/hPepT1 cells. Higher IL8 expression level and stronger activation of p38 MAP kinase were detected in HT29-Cl.19A/hPepT1 cells compared to cells transfected with empty vector upon EPEC infection. Conclusion: 1) EPEC induces functional expression of hPepT1 in colonocytes, 2) hPepT1 is involved in EPEC-mediated inflammation, and 3) LR-associated PepT1 plays a role in modulating bacterial-epithelial interactions in the colon, suggesting a novel function of this transporter in epithelial cells.
M1164 History of Medical Hospitalization Predicts Future Need for Colectomy in Patients with Ulcerative Colitis Ashwin N. Ananthakrishnan, Mazen Issa, Dawn B. Beaulieu, Susan Skaros, Joshua F. Knox, Kathryn Lemke, Jeanne Emmons, Sarah J. Lundeen, Mary F. Otterson, David G. Binion Introduction: Patients who require hospitalization for the management of ulcerative colitis (UC) form a subset with severe disease. These patients may be more likely to require colectomy. There is limited data examining whether medical hospitalization is predictive of subsequent colectomy. Methods: This was a retrospective case control study utilizing the Inflammatory Bowel Disease center database at our academic referral center. Cases comprised UC patients who underwent colectomy for disease refractory to medical management. Patients who underwent colectomy for other reasons including dysplasia were excluded. Patients who had undergone colectomy elsewhere prior to seeking care at our center were also excluded. The control population comprised of all patients with UC who had not undergone colectomy. Results: There were a total of 246 UC patients included in our study with 103 being hospitalized sometime in their disease course (41.9%). A total of 27 patients underwent colectomy (11%). The mean age of the patients was 43.6 years (range 19 - 87 years) with 53% women. Colectomy patients had a younger mean age of diagnosis (29.0 years vs. 35.6
AGA Abstracts
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AGA Abstracts
joints. Future cohort and controlled studies are mandated to further evaluate the relationship between IBD and osteonecrosis. Results
M1165 Bacterial Effector Avra Stabilizes Cell Tight Junctions to Inhibit Inflammation in Intestinal Epithelial Cells Anne P. Liao, Elaine O. Petrof, Sumalatha Kuppireddi, Erika C. Claud, Jun Sun The type III secretory system (TTSS) is a protein transport device using by Gram-negative pathogenic bacteria, including Salmonella, enteropathogenic Escherichia coli, enterohaemorrhagic E. coli, or Pseudomonas spp. The TTSS allows bacteria to inject virulence proteins, called effectors, into the cytosol of their eukaryotic host cells. These effectors are responsible for the alteration of tight junction (TJ) structure and function in intestinal epithelial cells. AvrA is a newly described bacterial effector found in Salmonella and E. coli. We report here that AvrA expression stabilizes cell permeability/tight junctions in intestinal epithelial cells. Cells colonized with an AvrA-deficient bacterial strain (AvrA-) had decrease of cell permeability, disruption of TJs, and increased inflammatory response. In contrast, cells colonized with AvrA-sufficient bacteria maintained cell permeability and stabilized TJ structure. The transelectrical resistance decreased and this occurred after AvrA- colonization for only 30 min. Western blot data showed that TJ proteins, such as ZO-1, claudin, decreased after AvrA- colonization for only I hour, and this decrease lasted for over 24 hours. This difference was confirmed In Vivo. Fluorescent tracer showed that increased fluorescence was found in the blood of mice infected with AvrA- compared to those infected with the AvrA sufficient strains. AvrA- disrupted TJ structure and function and increased inflammation In Vivo, compared to the AvrA sufficient strain. Our data further demonstrate that the TJ disruption is regulated directly by AvrA rather than indirectly through inflammatory cytokine regulation. An intriguing aspect of this study is that AvrA stabilized the TJs, even though the other TTSS proteins, SopB, SopE, SopE2, and SpiA, are known to disrupt TJs. This is consistent with other studies demonstrating a different role of AvrA in eliciting fluid accumulation compared to the other effector proteins such as sopA, sopB, sopD, or sopE2. We have also previously shown that AvrA attenuates the key proinflammatory NF-κB transcription factor, activate the β-catenin transcription factor, and inhibit cell apoptosis in mouse epithelial cells. Thus, AvrA may play a role as an anti-inflammatory protein to stabilize TJs and prevent cell death, and balance the opposing action of other bacterial effectors. Our findings indicate an important role for the bacterial effector AvrA in regulating on TJs of intestinal epithelial cells during inflammation. The role of AvrA represents a highly refined bacterial strategy that helps the bacteria survive in the host and dampen inflammatory response.
M1163 Depression in Inflammatory Bowel Disease Patients Katja Grubelic Ravic, Zeljko Krznaric, Silvija Cukovic-Cavka, Marko Brinar, Marina Grubic, Boris N. Vucelic Psychological disorders are highly prevalent in patients with inflammatory bowel disease (IBD). Depression may influence the clinical course of IBD and affect patient's quality of life. Objective. To determine the prevalence of depression in patient with IBD and the correlation between depression , patients age, disease duration and number of hospitalizations. Methods. 157 IBD patients from tertiary referral centre( 91 with Crohn's disease (CD), 62 with ulcerrative colitis (UC) and 3 unspecified ) completed the Zung Self-rating Depression Scale (SDS). The mean age of patients was 40 yr (15 - 69), and the mean duration of disease were 11,64 yr (1-40), the mean of number of hospitalization was 6,85 (0 - 30). Results. The mean SDS scores for the entire group were 43,43 (st.dev. 11.17) and the percentage of subjects with depression is 51,6%. There is no differences bettween patients with CD and those with UC in depression scores. There is no statistically significant correlation neither between patients age and depression scores nor between duration of illness and depression scores. Though, significant correlation has been found between depression and number of hospitalization. Conclusion. The patients with IBD have high rate of depression, independently to their age and disease duration. Patients who experience more hospitalizations score higher on depression scale. It is important for clinicians to assess depression among patients with IBD and recommend psychological treatment.
M1166 PepT1 Associated with Lipid Rafts Modulates Bacterial-Epithelial Interactions Hang Thi Thu Nguyen, Guillaume Dalmasso, Shanthi V. Sitaraman, Didier Merlin Background and Aims: PepT1 is a di/tripeptide transporter normally expressed in the small intestine and induced in colon under inflammatory conditions such as inflammatory bowel disease. We previously showed the localization of PepT1 in lipid rafts (LR) of epithelial cells. Our aim was to investigate the role of PepT1associated with LR in inflamed colonic epithelial cells. Methods: human colonic epithelial HT29-Cl.19A cells, which do not express human PepT1 (hPepT1) under normal conditions, were infected with enteropathogenic E. coli (EPEC). hPepT1 promoter activity was determined by luciferase assay. hPepT1 expression was assessed by RT-PCR, Western blot and immunofluorescence staining. hPepT1 transport activity was measured by uptake experiments. The presence of hPepT1 in LR fractions prepared from EPEC-infected HT29-Cl.19A cells was determined by Western blot analysis. HT29-Cl.19A cells stably transfected with wild type hPepT1 (HT29-Cl.19A/hPepT1) or its mutated forms that were not found in LR were examined for EPEC-induced expression of pro-inflammatory cytokine IL8 by real time RT-PCR and ELISA. Results: EPEC induced hPepT1 promoter activity, mRNA and protein expression and transport activity in HT29Cl.19A cells. Furthermore, hPepT1 co-localized with LR marker GM1 in EPEC-infected HT29-Cl.19A cells indicating its association with LR. Remarkably, expression of PepT1 in LR resulted in reduced EPEC attachment on HT29-Cl.19A/hPepT1 cells. Higher IL8 expression level and stronger activation of p38 MAP kinase were detected in HT29-Cl.19A/hPepT1 cells compared to cells transfected with empty vector upon EPEC infection. Conclusion: 1) EPEC induces functional expression of hPepT1 in colonocytes, 2) hPepT1 is involved in EPEC-mediated inflammation, and 3) LR-associated PepT1 plays a role in modulating bacterial-epithelial interactions in the colon, suggesting a novel function of this transporter in epithelial cells.
M1164 History of Medical Hospitalization Predicts Future Need for Colectomy in Patients with Ulcerative Colitis Ashwin N. Ananthakrishnan, Mazen Issa, Dawn B. Beaulieu, Susan Skaros, Joshua F. Knox, Kathryn Lemke, Jeanne Emmons, Sarah J. Lundeen, Mary F. Otterson, David G. Binion Introduction: Patients who require hospitalization for the management of ulcerative colitis (UC) form a subset with severe disease. These patients may be more likely to require colectomy. There is limited data examining whether medical hospitalization is predictive of subsequent colectomy. Methods: This was a retrospective case control study utilizing the Inflammatory Bowel Disease center database at our academic referral center. Cases comprised UC patients who underwent colectomy for disease refractory to medical management. Patients who underwent colectomy for other reasons including dysplasia were excluded. Patients who had undergone colectomy elsewhere prior to seeking care at our center were also excluded. The control population comprised of all patients with UC who had not undergone colectomy. Results: There were a total of 246 UC patients included in our study with 103 being hospitalized sometime in their disease course (41.9%). A total of 27 patients underwent colectomy (11%). The mean age of the patients was 43.6 years (range 19 - 87 years) with 53% women. Colectomy patients had a younger mean age of diagnosis (29.0 years vs. 35.6
AGA Abstracts
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