Diminished Expression of Corticotropin-Releasing Hormone Receptor 2 in Human Colon Cancer Promotes Tumor Growth and Epithelial-to-Mesenchymal Transition via Persistent Interleukin-6/Stat3 Signaling

Cellular mechanisms in basic and clinical gastroenterology and hepatolog

Modification of Salmonella Typhimurium Motility by the Probiotic Yeast Strain Saccharomyces boulardii

BACKGROUND: Motility is an important component of Salmonella enterica serovar Typhimurium (ST) pathogenesis allowing the bacteria to move into appropriate niches, across the mucus layer and invade the intestinal epithelium. In vitro, flagellum-associated motility is closely related to the invasive properties of ST. The probiotic yeast Saccharomyces boulardii BIOCODEX (S.b-B) is widely prescribed for the prophylaxis and treatment of diarrheal diseases caused by bacteria or antibiotics. In case of Salmonella infection, S.b-B has been shown to decrease ST invasion of T84 colon cell line. The present study was designed to investigate the impact of S.b-B on ST motility. METHODOLOGY/PRINCIPAL FINDINGS: Experiments were performed on human colonic T84 cells infected by the Salmonella strain 1344 alone or in the presence of S.b-B. The motility of Salmonella was recorded by time-lapse video microscopy. Next, a manual tracking was performed to analyze bacteria dynamics (MTrackJ plugin, NIH image J software). This revealed that the speed of bacterial movement was modified in the presence of S.b-B. The median curvilinear velocity (CLV) of Salmonella incubated alone with T84 decreased from 43.3 µm/sec to 31.2 µm/sec in the presence of S.b-B. Measurement of track linearity (TL) showed similar trends: S.b-B decreased by 15% the number of bacteria with linear tract (LT) and increased by 22% the number of bacteria with rotator tract (RT). Correlation between ST motility and invasion was further established by studying a non-motile flagella-deficient ST strain. Indeed this strain that moved with a CLV of 0.5 µm/sec, presented a majority of RT and a significant decrease in invasion properties. Importantly, we show that S.b-B modified the motility of the pathogenic strain SL1344 and significantly decreased invasion of T84 cells by this strain. CONCLUSIONS: This study reveals that S.b-B modifies Salmonella's motility and trajectory which may account for the modification of Salmonella's invasion

Clostridial Glucosylating Toxins Enter Cells via Clathrin-Mediated Endocytosis

Clostridium difficile toxin A (TcdA) and toxin B (TcdB), C. sordellii lethal toxin (TcsL) and C. novyi α-toxin (TcnA) are important pathogenicity factors, which represent the family of the clostridial glucosylating toxins (CGTs). Toxin A and B are associated with antibiotic-associated diarrhea and pseudomembraneous colitis. Lethal toxin is involved in toxic shock syndrome after abortion and α-toxin in gas gangrene development. CGTs enter cells via receptor-mediated endocytosis and require an acidified endosome for translocation of the catalytic domain into the cytosol. Here we studied the endocytic processes that mediate cell internalization of the CGTs. Intoxication of cells was monitored by analyzing cell morphology, status of Rac glucosylation in cell lysates and transepithelial resistance of cell monolayers. We found that the intoxication of cultured cells by CGTs was strongly delayed when cells were preincubated with dynasore, a cell-permeable inhibitor of dynamin, or chlorpromazine, an inhibitor of the clathrin-dependent endocytic pathway. Additional evidence about the role of clathrin in the uptake of the prototypical CGT family member toxin B was achieved by expression of a dominant-negative inhibitor of the clathrin-mediated endocytosis (Eps15 DN) or by siRNA against the clathrin heavy chain. Accordingly, cells that expressed dominant-negative caveolin-1 were not protected from toxin B-induced cell rounding. In addition, lipid rafts impairment by exogenous depletion of sphingomyelin did not decelerate intoxication of HeLa cells by CGTs. Taken together, our data indicate that the endocytic uptake of the CGTs involves a dynamin-dependent process that is mainly governed by clathrin

Effects of adenosine A2A receptor activation and alanyl-glutamine in Clostridium difficile toxin-induced ileitis in rabbits and cecitis in mice

<p>Abstract</p> <p>Background</p> <p>Severe <it>Clostridium difficile </it>toxin-induced enteritis is characterized by exuberant intestinal tissue inflammation, epithelial disruption and diarrhea. Adenosine, through its action on the adenosine A_2Areceptor, prevents neutrophillic adhesion and oxidative burst and inhibits inflammatory cytokine production. Alanyl-glutamine enhances intestinal mucosal repair and decreases apoptosis of enterocytes. This study investigates the protection from enteritis by combination therapy with ATL 370, an adenosine A_2Areceptor agonist, and alanyl-glutamine in a rabbit and murine intestinal loop models of <it>C. difficile </it>toxin A-induced epithelial injury.</p> <p>Methods</p> <p>Toxin A with or without alanyl-glutamine was administered intraluminally to rabbit ileal or murine cecal loops. Animals were also given either PBS or ATL 370 parenterally. Ileal tissues were examined for secretion, histopathology, apoptosis, Cxcl1/KC and IL-10.</p> <p>Results</p> <p>ATL 370 decreased ileal secretion and histopathologic changes in loops treated with Toxin A. These effects were reversed by the A_2Areceptor antagonist, SCH 58261, in a dose-dependent manner. The combination of ATL 370 and alanyl-glutamine significantly further decreased ileal secretion, mucosal injury and apoptosis more than loops treated with either drug alone. ATL 370 and alanyl-glutamine also decreased intestinal tissue KC and IL-10.</p> <p>Conclusions</p> <p>Combination therapy with an adenosine A_2Areceptor agonist and alanyl-glutamine is effective in reversing <it>C. difficile </it>toxin A-induced epithelial injury, inflammation, secretion and apoptosis in animals and has therapeutic potential for the management of <it>C. difficile </it>infection.</p

Saccharomyces boulardii Improves Intestinal Cell Restitution through Activation of the α2β1 Integrin Collagen Receptor

Intestinal epithelial cell damage is frequently seen in the mucosal lesions of inflammatory bowel diseases such as ulcerative colitis or Crohn's disease. Complete remission of these diseases requires both the cessation of inflammation and the migration of enterocytes to repair the damaged epithelium. Lyophilized Saccharomyces boulardii (Sb, Biocodex) is a nonpathogenic yeast widely used as a therapeutic agent for the treatment and prevention of diarrhea and other gastrointestinal disorders. In this study, we determined whether Sb could accelerate enterocyte migration. Cell migration was determined in Sb force-fed C57BL6J mice and in an in vitro wound model. The impact on α2β1 integrin activity was assessed using adhesion assays and the analysis of α2β1 mediated signaling pathways both in vitro and in vivo. We demonstrated that Sb secretes compounds that enhance the migration of enterocytes independently of cell proliferation. This enhanced migration was associated with the ability of Sb to favor cell-extracellular matrix interaction. Indeed, the yeast activates α2β1 integrin collagen receptors. This leads to an increase in tyrosine phosphorylation of cytoplasmic molecules, including focal adhesion kinase and paxillin, involved in the integrin signaling pathway. These changes are associated with the reorganization of focal adhesion structures. In conclusion Sb secretes motogenic factors that enhance cell restitution through the dynamic regulation of α2β1 integrin activity. This could be of major importance in the development of novel therapies targeting diseases characterized by severe mucosal injury, such as inflammatory and infectious bowel diseases

Introduction and Validation of a Novel Acute Pancreatitis Digital Tool: Interrogating Large Pooled Data From 2 Prospectively Ascertained Cohorts

Objectives: Acute pancreatitis (AP) is a sudden onset, rapidly evolving inflammatory response with systemic inflammation and multiorgan failure (MOF) in a subset of patients. New highly accurate clinical decision support tools are needed to allow local doctors to provide expert care. Methods: Ariel Dynamic Acute Pancreatitis Tracker (ADAPT) is a digital tool to guide physicians in ordering standard tests, evaluate test results and model progression using available data, propose emergent therapies. The accuracy of the severity score calculators was tested using 2 prospectively ascertained Acute Pancreatitis Patient Registry to Examine Novel Therapies in Clinical Experience cohorts (pilot University of Pittsburgh Medical Center, n = 163; international, n = 1544). Results: The ADAPT and post hoc expert-calculated AP severity scores were 100% concordant in both pilot and international cohorts. High-risk criteria of all 4 severity scores at admission were associated with moderately-severe or severe AP and MOF (both P < 0.0001) and prediction of no MOF was 97.8% to 98.9%. The positive predictive value for MOF was 7.5% to 14.9%. Conclusions: The ADAPT tool showed 100% accuracy with AP predictive metrics. Prospective evaluation of ADAPT features is needed to determine if additional data can accurately predict and mitigate severe AP and MOF

Worldwide Variations in Demographics, Management, and Outcomes of Acute Pancreatitis

Background & Aims Few studies have compared regional differences in acute pancreatitis. We analyzed data from an international registry of patients with acute pancreatitis to evaluate geographic variations in patient characteristics, management, and outcomes. Methods We collected data from the APPRENTICE registry of patients with acute pancreatitis, which obtains information from patients in Europe (6 centers), India (3 centers), Latin America (5 centers), and North America (8 centers) using standardized questionnaires. Our final analysis included 1,612 patients with acute pancreatitis (median age, 49 years; 53% male, 62% white) enrolled from August 2015 through January 2018. Results Biliary (45%) and alcoholic acute pancreatitis (21%) were the most common etiologies. Based on the revised Atlanta classification, 65% of patients developed mild disease, 23% moderate, and 12% severe. The mean age of patients in Europe (58 years) was older than mean age for all 4 regions (46 years) and a higher proportion of patients in Europe had comorbid conditions (73% vs 50% overall). The predominant etiology of acute pancreatitis in Latin America was biliary (78%), whereas alcohol-associated pancreatitis accounted for the highest proportion of acute pancreatitis cases in India (45%). Pain was managed with opioid analgesics in 93% of patients in North America versus 27% of patients in the other 3 regions. Cholecystectomies were performed at the time of hospital admission for most patients in Latin America (60% vs 15% overall). A higher proportion of European patients with severe acute pancreatitis died during the original hospital stay (44%) compared with the other 3 regions (15%). Conclusions We found significant variation in demographics, etiologies, management practices, and outcomes of acute pancreatitis worldwide

Incidence and risk factors of oral feeding intolerance in acute pancreatitis: Results from an international, multicenter, prospective cohort study

Background: Inability to advance to an oral diet, or oral feeding intolerance, is a common complication in patients with acute pancreatitis associated with worse clinical outcomes. The factors related to oral feeding intolerance are not well studied. Objective: We aimed to determine the incidence and risk factors of oral feeding intolerance in acute pancreatitis. Methods: Patients were prospectively enrolled in the Acute Pancreatitis Patient Registry to Examine Novel Therapies in Clinical Experience, an international acute pancreatitis registry, between 2015 and 2018. Oral feeding intolerance was defined as worsening abdominal pain and/or vomiting after resumption of oral diet. The timing of the initial feeding attempt was stratified based on the day of hospitalization. Multivariable logistic regression was performed to assess for independent risk factors/predictors of oral feeding intolerance. Results: Of 1233 acute pancreatitis patients included in the study, 160 (13%) experienced oral feeding intolerance. The incidence of oral feeding intolerance was similar irrespective of the timing of the initial feeding attempt relative to hospital admission day (p = 0.41). Patients with oral feeding intolerance were more likely to be younger (45 vs. 50 years of age), men (61% vs. 49%), and active alcohol users (44% vs. 36%). They also had higher blood urea nitrogen (20 vs. 15 mg/dl; p < 0.001) and hematocrit levels (41.7% vs. 40.5%; p = 0.017) on admission; were more likely to have a nonbiliary acute pancreatitis etiology (69% vs. 51%), systemic inflammatory response syndrome of 2 or greater on admission (49% vs. 35%) and at 48 h (50% vs. 26%), develop pancreatic necrosis (29% vs. 13%), moderate to severe acute pancreatitis (41% vs. 24%), and have a longer hospital stay (10 vs. 6 days; all p < 0.04). The adjusted analysis showed that systemic inflammatory response syndrome of 2 or greater at 48 h (odds ratio 3.10; 95% confidence interval 1.83-5.25) and a nonbiliary acute pancreatitis etiology (odds ratio 1.65; 95% confidence interval 1.01-2.69) were independent risk factors for oral feeding intolerance. Conclusion: Oral feeding intolerance occurs in 13% of acute pancreatitis patients and is independently associated with systemic inflammatory response syndrome at 48 h and a nonbiliary etiology

Mortality in acute pancreatitis with persistent organ failure is determined by the number, type, and sequence of organ systems affected

Background: Persistent organ failure (POF) is the strongest determinant of mortality in acute pancreatitis (AP). There is a paucity of data regarding the impact of different POF attributes on mortality and the role of different characteristics of systemic inflammatory response syndrome (SIRS) in the risk of developing POF. Objective: We aimed to assess the association of POF dynamic features with mortality and SIRS characteristics with POF. Methods: We studied 1544 AP subjects prospectively enrolled at 22 international centers (APPRENTICE consortium). First, we estimated the association of onset, duration, and maximal score of SIRS with POF. Then, we evaluated the risk of mortality based on POF onset, duration, number, type, and sequence of organs affected. Analyses were adjusted for potential confounders. Results: 58% had SIRS, 11% developed POF, and 2.5% died. Early SIRS, persistent SIRS, and maximal SIRS score ≥ 3 were independently associated with higher risk of POF (p < 0.05). Mortality risk in POF was higher with two (33%, odds ratio [OR] = 10.8, 3.3-34.9) and three (48%, OR = 20.2, 5.9-68.6) organs failing, in comparison to single POF (4%). In subjects with multiple POF, mortality was higher when the cardiovascular and respiratory systems failed first or concurrently as compared to when the renal system failed first or concurrently with other organ (p < 0.05). In multivariate regression model, the number and sequence of organs affected in POF were associated with mortality (p < 0.05). Onset and duration of POF had no impact mortality. Conclusion: In AP patients with POF, the risk of mortality is influenced by the number, type, and sequence of organs affected. These results are useful for future revisions of AP severity classification systems