Correction: The Probiotic Mixture VSL#3 Accelerates Gastric Ulcer Healing by Stimulating Vascular Endothelial Growth Factor.

[This corrects the article DOI: 10.1371/journal.pone.0058671.].

The probiotic mixture VSL#3 accelerates gastric ulcer healing by stimulating vascular endothelial growth factor.

Studies assessing the effect and mechanism of probiotics on diseases of the upper gastrointestinal tract (GI) including gastric ulcers are limited despite extensive work and promising results of this therapeutic option for other GI diseases. In this study, we investigated the mechanisms by which the probiotic mixture VSL#3 (a mixture of eight probiotic bacteria including Lactobacilli, Bifidobacteria and Streptococcus species) heals acetic acid induced gastric ulcer in rats. VSL#3 was administered orally at low (6 × 10(9) bacteria) or high (1.2 × 10(10) bacteria) dosages from day 3 after ulcer induction for 14 consecutive days. VSL#3 treatments significantly enhanced gastric ulcer healing in a dose-dependent manner. To assess the mechanism(s) whereby VSL#3 exerted its protective effects, we quantified the gene expression of several pro-inflammatory cytokines, protein and expression of stomach mucin-Muc5ac, regulatory cytokine-IL-10, COX-2 and various growth factors. Of all the components examined, only expression and protein production of VEGF was increased 332-fold on day 7 in the ulcerated tissues of animals treated with VSL#3. Predictably, animals treated with VEGF neutralizing antibody significantly delayed gastric ulcer healing in VSL#3 treated animals. This is the first report to demonstrate high efficacy of the probiotic mixture VSL#3 in enhancing gastric ulcer healing. Probiotic efficacy was effective at higher concentrations of VSL#3 by specifically increasing the expression and production of angiogenesis promoting growth factors, primarily VEGF.

Tumor necrosis factor-α and Muc2 mucin play major roles in disease onset and progression in dextran sodium sulphate-induced colitis.

The sequential events and the inflammatory mediators that characterize disease onset and progression of ulcerative colitis (UC) are not well known. In this study, we evaluated the early pathologic events in the pathogenesis of colonic ulcers in rats treated with dextran sodium sulfate (DSS). Following a lag phase, day 5 of DSS treatment was found clinically most critical as disease activity index (DAI) exhibited an exponential rise with severe weight loss and rectal bleeding. Surprisingly, on days 1-2, colonic TNF-α expression (70-80-fold) and tissue protein (50-fold) were increased, whereas IL-1ß only increased on days 7-9 (60-90-fold). Days 3-6 of DSS treatment were characterized by a prominent down regulation in the expression of regulatory cytokines (40-fold for IL-10 and TGFß) and mucin genes (15-18 fold for Muc2 and Muc3) concomitant with depletion of goblet cell and adherent mucin. Remarkably, treatment with TNF-α neutralizing antibody markedly altered DSS injury with reduced DAI, restoration of the adherent and goblet cell mucin and IL-1ß and mucin gene expression. We conclude that early onset colitis is dependent on TNF-α that preceded depletion of adherent and goblet cell mucin prior to epithelial cell damage and these biomarkers can be used as therapeutic targets for UC.

Fusobacterium nucleatum infection of colonic cells stimulates MUC2 mucin and tumor necrosis factor alpha.

The etiology of inflammatory bowel disease is not completely known, but it is influenced by the presence of normal gut microflora as well as yet-unrecognized pathogens. The anaerobic, Gram-negative bacterial species Fusobacterium nucleatum is a common resident of the human mouth and gut and varies in its pathogenic potential. In this study, we demonstrate that highly invasive F. nucleatum isolates derived from the inflamed guts of Crohn's disease patients evoked significantly greater MUC2 and tumor necrosis factor alpha (TNF-α) gene expression than minimally invasive strains isolated from the noninflamed gut in human colonic epithelial cells and in a rat ligated colonic loop model of infection. Only live F. nucleatum induced mucin secretion and TNF-α expression in direct contact with and/or during invasion of colonic cells. In rat colons, mucin secretion was augmented in response to a highly invasive F. nucleatum isolate but was unaffected by treatment with a minimally invasive strain. Taken together, these studies reveal that F. nucleatum may represent a challenging pathogen in the etiology of gut inflammatory diseases and highlight the importance of different pathotypes of candidate bacterial species in disease pathogenesis.

Muc-2-deficient mice display a sex-specific, COX-2-related impairment of gastric mucosal repair.

Mucus is known to contribute significantly to the prevention and repair of mucosal damage throughout the gastrointestinal tract. Although not normally expressed in the stomach, mucin-2 (MUC-2, encoded by the MUC2 gene) is expressed in certain disease states. The aim of this study was to determine in a mouse model whether the absence of Muc-2 would result in impaired susceptibility to and healing of gastric mucosal injury. Acute gastric damage was induced in mice deficient in Muc-2 and in wild-type controls, through oral administration of indomethacin. Chronic gastric ulcers were induced by serosal application of acetic acid. The extent of injury and the extent of healing of the damage over time were examined in both models. Indomethacin administration caused similar levels of gastric damage in Muc-2-deficient and wild-type mice, but the erosions healed more slowly in the former. Acetic acid-induced gastric ulcers were initially similar in size in Muc-2-deficient and wild-type mice of both sexes, but ulcer healing was significantly impaired in male Muc-2-deficient mice. Induction of cyclooxygenase-2 in the stomach, in response to indomethacin- or acetic acid-induced ulceration, was significantly reduced in male Muc-2-deficient mice. This phenomenon, and the sex specificity, was also apparent in bone marrow-derived macrophages stimulated with endotoxin. These results demonstrate a marked impairment of gastric mucosal repair in male Muc-2-deficient mice that may be related to an insufficient induction of cyclooxygenase-2, an enzyme known to contribute to mucosal repair.

Role of intestinal mucins in innate host defense mechanisms against pathogens.

Gastrointestinal mucins produced by goblet cells comprise the main structural components of the mucus layer. Mucins play a critical role in the maintenance of mucosal homeostasis and are responsible for the differential effector and regulatory responses against a plethora of microorganisms, including commensals and pathogens. In this review, we present a comprehensive overview on mucin biology, its properties, classification and gene assembly. We also consider the structure of the mucin gene, its proteins and its role in innate host defenses. We compare the various mucin secretagogues and the differential regulatory pathways involved in mucin biosynthesis and secretion during normal and diverse pathogenic conditions. Finally, we summarize the putative uncharted aspects of mucin-derived innate host defenses, whose exploration will help drug developers to identify factors that can strengthen mucosal integrity and will facilitate basic science research into curative treatments for gastrointestinal diseases.

Biologic therapies against inflammatory bowel disease: a dysregulated immune system and the cross talk with gastrointestinal mucosa hold the key.

Inflammatory bowel disease (IBD) is a GI tract disorder that manifests as either Ulcerative colitis (UC) or Crohn's disease (CD). The precise etiology of IBD is still not completely elucidated but research into the immunopathogenesis of IBD suggests that dysfunctions of the intestinal immune system and cross-reactivity against host epithelial cells hold the key. In both UC and CD, polarized immune activity towards Th1 (marked by upregulation of TNF-alpha, IL-1beta, IFN-gamma, IL-6) and Th17 (marked by IL-17 secretion) response is reported, while UC appears to exhibit an added contribution of Th2 responses (characterized by secretion of IL-4, IL-5, and IL-13). Additionally, other molecules involved in leukocyte trafficking (adhesion molecules), chemokines (IL-8) and tissue repair molecules (PGE(2) and its receptors) are also crucial. Emergence of these new paradigms in the pathogenesis of IBD led to a recent trend of novel biological therapies that specifically inhibit molecules involved in the inflammatory cascade. In this review, we critically discuss recent advances in the pathogenesis of IBD, drug therapies (conventional versus biologic), drug efficacy and pharmacokinetics (murine versus human versus chimeric) and their adverse effects. We also discuss emerging novel biological therapies targeting pro-inflammatory cytokines including TNF-alpha and IFN-gamma, cytokine receptors and those targeting adhesion molecules-anti-integrin and anti-ICAM antibodies. Other potential approaches using anti-inflammatory cytokines (IL-10), anti-sense oligonucleotide and probiotics are also discussed. Finally, we summarized few imperative targets whose more detailed exploration can help to pave the way for an efficacious IBD therapy.

High prevalence of ACE DD genotype among north Indian end stage renal disease patients.

BACKGROUND: The Renin-Angiotensin system (RAS) is a key regulator of both blood pressure and kidney functions and their interaction. In such a situation, genetic variability in the genes of different components of RAS is likely to contribute for its heterogeneous association in the renal disease patients. Angiotensin converting enzyme-1 (ACE-1) is an important component of RAS which determines the vasoactive peptide Angiotensin-II. METHODS: In the present study, we have investigated 127 ESRD patients and 150 normal healthy controls from north India to deduce the association between ACE gene polymorphism and ESRD. The inclusion criteria for patients included a constantly elevated serum creatinine level above normal range (ranging from 3.4 to 15.8) and further the patients were recommended for renal transplantation. A total of 150 normal healthy controls were also genotyped for ACE I/D polymorphism. The criterion of defining control sample as normal was totally based on the absence of any kidney disease determined from the serum creatinin level. Genotyping of ACE I/D were assayed by polymerase chain reaction (PCR) based DNA amplification using specific flanking primers Based on the method described elsewhere. RESULTS: The difference of DD and II genotypes was found highly significant among the two groups (p = 0.025; OR = 3.524; 95% CI = 1.54-8.07). The combined genotype DD v/s ID+II comparison validated that DD genotype is a high risk genotype for ESRD (p = 0.001; OR = 5.74; 95% CI limit = 3.4-8.5). However, no correlation was obtained for different biochemical parameters of lipid profile and renal function among DD and non DD genotype. Interestingly, approximately 87% of the DD ESRD patients were found hypertensive in comparison to the 65% patients of non DD genotype CONCLUSION: Based on these observations we conclude that ACE DD genotype implicate a strong possible role in the hypertensive state and in renal damage among north Indians. The study will help in predetermining the timing, type and doses of anti-hypertensive therapy for ESRD patients.

Desmodium gangeticum: a potent anti-ulcer agent.

The present study was designed to investigate anti-ulcerogenic property of ethanolic extract of Desmodium gangeticum (DG) against cold restraint (CRU, 2 hr cold restraint stress), aspirin (ASP, 150 mg/kg orally), alcohol (AL, absolute alcohol 1 ml/200gm) and pyloric ligation (PL, 4 hr pylorus ligation) induced gastric ulcer models in Sprague Dawley rats, and histamine (HST, 0.25 mg/kg) induced duodenal ulcer in guinea pigs. We found that DG at a dose of 200mg/kg, (orally), markedly decreased the incidence of ulcers in all the above models. DG showed significant protection against CRU (68.37%), AL (88.87%), ASP (38.2%), PL (40.63%) and HST (63.15%) induced ulcer models, whereas standard drug omeprazole (OMZ) showed protection index of 83.86, 56.35, 70.31 and 84.21%, respectively in CRU, ASP, PL and HST models. Sucralfate as standard drug showed 92.64% protection in AL model. DG significantly reduced acid secretion 41.61%, whereas OMZ produced 43.13% reduction. Treatment with DG showed increase in mucin secretion by 56.17%, whereas OMZ showed 12.45% increase. Anti-ulcer effect of DG may be due to its cytoprotective effect along with antisecretory activity and could act as a potent therapeutic agent against peptic ulcer disease.

Allophylus serratus: a plant with potential anti-ulcerogenic activity.

Allophylus serratus is known to possess various therapeutic properties. We evaluated the anti-ulcerogenic property of crude ethanolic extract of Allophylus serratus (AS) in different ulcer models in Sprague-Dawley rats. The extract at 400 mg/kg body weight, once daily, orally has a significant effect in cold restraint (CRU, 2 h cold restraint stress), aspirin (ASA, 150 mg/kg body weight, orally), alcohol (AL, 1 ml/200 gm of absolute alcohol) and pyloric ligation (PL, 4h ligation) induced gastric ulcer models as it showed protection index of 71.28, 62.50, 90.84 and 64.29% protection, respectively whereas, standard drug omeprazole (OMZ, 10mg/kg body weight) has shown protection index of 85.70, 74.99 and 74.99 in CRU, ASA and PL model respectively. Sucralfate (SUC, 500 mg/kg body weight) as a standard drug in AL model has 93.20% protection. Furthermore, AS has significantly decreased the free acidity (72.41%), total acidity (47.97%) and peptic activity (24.59%), respectively as well as has significantly increased the mucus secretion (29.41%). Conclusively the ulcer protective effect of AS may be due to its anti-secretory along with cytoprotective mechanism.

Evaluation of anti-ulcerogenic and ulcer-healing properties of Ocimum sanctum Linn.

Ocimum sanctum (OS) is known to possess various therapeutic properties. We evaluated its anti-ulcerogenic activity in cold restraint (CRU), aspirin (ASP), alcohol (AL), pyloric ligation (PL) induced gastric ulcer models in Sprague-Dawley rats, histamine-induced duodenal (HST) ulcer in guinea pigs, and ulcer-healing activity, in acetic acid-induced (AC) chronic ulcer model. We found that OS, decreased the incidence of ulcers and also enhanced the healing of ulcers. OS at a dose of 100 mg/kg was found to be effective in CRU (65.07%), ASP (63.49%), AL (53.87%), PL (62.06%), and HST (61.76%) induced ulcer models and significantly reduced free, total acidity and peptic activity by 72.58, 58.63, 57.6%, respectively, and increased mucin secretion by 34.61%. Additionally, OS completely healed the ulcers within 20 days of treatment in AC. We observed that anti-ulcer effect of OS may be due to its cytoprotective effect rather than antisecretory activity. Conclusively, OS was found to possess potent anti-ulcerogenic as well as ulcer-healing properties and could act as a potent therapeutic agent against peptic ulcer disease.