Salmonella enterica serovar Typhimurium adhesion and cytotoxicity during epithelial cell stress is reduced by Lactobacillus rhamnosus GG

Background

Physiological stressors may alter susceptibility of the host intestinal epithelium to infection by enteric pathogens. In the current study, cytotoxic effect, adhesion and invasion of Salmonella enterica serovar Typhimurium (S. Typhimurium) to Caco-2 cells exposed to thermal stress (41°C, 1 h) was investigated. Probiotic bacteria have been shown to reduce interaction of pathogens with the epithelium under non-stress conditions and may have a significant effect on epithelial viability during infection; however, probiotic effect on pathogen interaction with epithelial cells under physiological stress is not known. Therefore, we investigated the influence of Lactobacillus rhamnosus GG and Lactobacillus gasseri on Salmonella adhesion and Salmonella-induced cytotoxicity of Caco-2 cells subjected to thermal stress.

Results

Thermal stress increased the cytotoxic effect of both S. Typhimurium (P = 0.0001) and nonpathogenic E. coli K12 (P = 0.004) to Caco-2 cells, and resulted in greater susceptibility of cell monolayers to S. Typhimurium adhesion (P = 0.001). Thermal stress had no significant impact on inflammatory cytokines released by Caco-2 cells, although exposure to S. Typhimurium resulted in greater than 80% increase in production of IL-6 and IL-8. Blocking S. Typhimurium with anti-ShdA antibody prior to exposure of Salmonella decreased adhesion (P = 0.01) to non-stressed and thermal-stressed Caco-2 cells. Pre-exposure of Caco-2 cells to L. rhamnosus GG significantly reduced Salmonella-induced cytotoxicity (P = 0.001) and Salmonella adhesion (P = 0.001) to Caco-2 cells during thermal stress, while L. gasseri had no effect.

Conclusion

Results suggest that thermal stress increases susceptibility of intestinal epithelial Caco-2 cells to Salmonella adhesion, and increases the cytotoxic effect of Salmonella during infection. Use of L. rhamnosus GG as a probiotic may reduce the severity of infection during epithelial cell stress. Mechanisms by which thermal stress increases susceptibility to S. Typhimurium colonization and by which L. rhamnosus GG limits the severity of infection remain to be elucidated.     

NOD2 exonic variations in Iranian Crohn's disease patients

Purpose

The NOD2 gene is known to have a strong association with Crohn??s disease, but different trends were reported in occurrence of NOD2 variants in distinct ethnicities. The aim of this study was to assess all exonic sequences of the NOD2 gene in Iranian Crohn's disease patients and healthy controls to identify any existing variation and evaluate their association with Crohn's disease.

Methods

A total of 90 non-related Crohn's disease patients and 120 sex- and age-matched healthy controls of Iranian origin were enrolled in this study. The participants were referred to a tertiary center in a 2-year period (2006?C2008). The exonic regions of the NOD2 gene were amplified by polymerase chain reaction and evaluated by direct sequencing.

Results

A total of 21 sequence variations were identified among all exonic regions of the NOD2 gene, of which eight had an allele frequency of more than 5%. Eight new mutations (one in exon 2 and seven in exon 4) were observed. The three main variants (R702W, G908R, and 1007fs) showed allele frequencies of 13.3%, 2.2%, and 1.7%, respectively. Three new variations (P371T, A794P, and Q908H) and R702W mutation were significantly more frequent in Crohn's disease patients compared to controls.

Conclusions

Eight novel mutations were identified in the NOD2 exons, but the pathophysiological importance of these variants remains unclear. Iranian patients with their different genetic reservoirs may demonstrate some novel characteristics for disease susceptibility.     

Granulomas of Intestinal Tuberculosis and Crohn's Disease Can Be Differentiated by CD73 Cell Surface Marker Expression: A Pilot Study

Background

Intestinal tuberculosis (ITB) and Crohn's disease are similar granulomatous disorders. Granulomas are present in both and difficult to differentiate on histopathology alone. A recent study demonstrated recruitment of mesenchymal cells (MSCs) at the periphery of granulomas in lymph node tuberculosis which suppressed T cell responses. We hypothesized that granulomas of ITB would also recruit MSCs to evade host immune response.

Aim

The purpose of this study was to demonstrate MSC markers in granulomas of ITB and evaluate whether distribution of MSC markers could differentiate between granulomas of Crohn's and ITB.

Methods

We initially retrospectively enrolled 17 patients with confirmed ITB (8) or Crohn's (9) with granulomas on histopathology. Tissues were evaluated by immunofluorescence for MSC markers CD29, CD90, CD73 and absence of haematopoietic markers CD31, CD34, CD45 and CD14. Double-staining was done to confirm presence of MSCs. Subsequently, 23 postoperative specimens of Crohn's (18) and ITB (5) were analyzed for validation.

Results

Overall, 27 Crohn's and 13 ITB cases were assessed. CD29 and CD90 positive cells were noted around both ITB and Crohn's granulomas. MSC marker CD73 was expressed around the granulomas of ITB alone and was completely absent in the Crohn's. The subsequent assessment of granulomas in postoperative specimens of Crohn's and ITB also showed similar results.

Conclusion

Granulomas of ITB and Crohn's disease can be differentiated by CD73 MSC surface marker expression. The differential CD73 expression around ITB granuloma indicates that Mycobacterium tuberculosis evades host immunity by recruiting MSCs with CD73 expression. MSCs with increased CD73 expression could be the future for therapeutic intervention in Crohn's.     

Campylobacter jejuni isolates in Finnish patients differ according to the origin of infection

Background

Recent epidemiological analyses have implicated acute Campylobacter enteritis as a factor that may incite or exacerbate inflammatory bowel disease (IBD) in susceptible individuals. We have demonstrated previously that C. jejuni disrupts the intestinal barrier function by rapidly inducing epithelial translocation of non-invasive commensal bacteria via a transcellular lipid raft-mediated mechanism ('transcytosis'). To further characterize this mechanism, the aim of this current study was to elucidate whether C. jejuni utilizes M cells to facilitate transcytosis of commensal intestinal bacteria.

Results

C. jejuni induced translocation of non-invasive E. coli across confluent Caco-2 epithelial monolayers in the absence of disrupted transepithelial electrical resistance or increased permeability to a 3 kDa dextran probe. C. jejuni -infected monolayers displayed increased numbers of cells expressing the M cell-specific marker, galectin-9, reduced numbers of enterocytes that stained with the absorptive enterocyte marker, Ulex europaeus agglutinin-1, and reduced activities of enzymes typically associated with absorptive enterocytes (namely alkaline phosphatase, lactase, and sucrase). Furthermore, in Campylobacter -infected monolayers, E. coli were observed to be internalized specifically within epithelial cells displaying M-like cell characteristics.

Conclusion

These data indicate that C. jejuni may utilize M cells to promote transcytosis of non-invasive bacteria across the intact intestinal epithelial barrier. This mechanism may contribute to the inflammatory immune responses against commensal intestinal bacteria commonly observed in IBD patients.     

Truncation in the tcdC region of the Clostridium difficile PathLoc of clinical isolates does not predict increased biological activity of Toxin B or Toxin A

Background

The increased severity of disease associated with the NAP1 strain of Clostridium difficile has been attributed to mutations to the tcdC gene which codes for a negative regulator of toxin production. To assess the role of hyper-production of Toxins A and B in clinical isolates of Clostridium difficile, two NAP1-related and five NAP1 non-related strains were compared.

Methods

Sequencing was performed on tcdC, tcdR, and tcdE to determine if there were differences that might account for hyper-production of Toxin A and Toxin B in NAP1-related strains. Biological activity of Toxin B was evaluated using the HFF cell CPE assay and Toxin A biological activity was assessed using the Caco-2 Trans-membrane resistance assay.

Results

Our results confirm that Toxin A and Toxin B production in NAP1-related strains and ATCC 43255 occurs earlier in the exponential growth phase compared to most NAP1-nonrelated clinical isolates. Despite the hyper-production observed in ATCC 43255 it had no mutations in tcdC, tcdR or tcdE. Analysis of the other clinical isolates indicated that the kinetics and ultimate final concentration of Toxin A and B did not correlate with the presence or lack of alterations in tcdC, tcdR or tcdE.

Conclusion

Our data do not support a direct role for alterations in the tcdC gene as a predictor of hyperproduction of Toxin A and B in NAP1-related strains.     

Ras-related C3 botulinum toxin substrate 1 (RAC1) regulates glucose-stimulated insulin secretion via modulation of F-actin

Aims/hypothesis

The small G-protein ras-related C3 botulinum toxin substrate 1 (RAC1) plays various roles in mammalian cells, such as in the regulation of cytoskeletal organisation, cell adhesion, migration and morphological changes. The present study examines the effects of RAC1 ablation on pancreatic beta cell function.

Methods

Isolated islets from pancreatic beta cell-specific Rac1-knockout (betaRac1 ^?/?) mice and RAC1 knockdown INS-1 insulinoma cells treated with small interfering RNA were used to investigate insulin secretion and cytoskeletal organisation in pancreatic beta cells.

Results

BetaRac1 ^?/? mice showed decreased glucose-stimulated insulin secretion, while there were no apparent differences in islet morphology. Isolated islets from the mice had blunted insulin secretion in response to high glucose levels. In RAC1 knockdown INS-1 cells, insulin secretion was also decreased in response to high glucose levels, consistent with the phenotype of betaRac1 ^?/? mice. Even under high glucose levels, RAC1 knockdown INS-1 cells remained intact with F-actin, which inhibits the recruitment of the insulin granules, resulting in an inhibition of insulin secretion.

Conclusions/interpretation

In RAC1-deficient pancreatic beta cells, F-actin acts as a barrier for insulin granules and reduces glucose-stimulated insulin secretion.     

Evaluation of Early Atherosclerosis in Patients with Inflammatory Bowel Disease

Background

Data regarding early atherosclerosis and inflammatory bowel disease are limited and conflicting results are present.

Aims

The purpose of this study was to evaluate serological and sonographical evidence of subclinical vascular involvement in patients with inflammatory bowel disease.

Methods

Thirty-nine patients with inflammatory bowel disease (20 Crohn's disease, and 19 ulcerative colitis patients) and 31 healthy controls were consecutively enrolled in the study. Flow mediated dilatation of the brachial artery and intima media thickness assessments of the common carotid artery were measured sonographically. Soluble CD40 ligand levels were evaluated. Crohn's disease activity index and modified Truelove-Witt’s criteria were also noted.

Results

Age, sex distribution, serum lipids, smoking status, and intima media thickness of the common carotid artery were similar between the inflammatory bowel disease patients and controls (p > 0.05). However, both endothelium dependent and independent flow mediated dilatation values were significantly impaired in the inflammatory bowel disease group compared with healthy controls (p < 0.05). Erythrocyte sedimentation rate, C-reactive protein and soluble CD40 ligand values were significantly increased in inflammatory bowel disease patients compared with controls (p < 0.05), and soluble CD40 ligand was negatively correlated with flow mediated dilatation (r = ?0.3, p < 0.05). Flow mediated dilatation was significantly predicted from the concentrations of C-reactive protein and soluble CD40 ligand.

Conclusion

Functional atherosclerosis is present in inflammatory bowel disease before early structural changes occur in vasculature. Higher sCD40L may indicate worse vascular outcome for IBD.     

Osteoprotegerin Exerts Its Pro-inflammatory Effects Through Nuclear Factor-κB Activation

Background

Osteoprotegerin (OPG), a soluble member of the tumor necrosis factor (TNF) receptor super-family, is a key factor inhibiting the differentiation and activation of osteoclasts. It has recently been implicated as a disease marker for inflammatory bowel disease (IBD) yet its role in the intestinal epithelial inflammatory response remains unknown.

Aim

The primary objective of this study was to investigate whether OPG has a role in intestinal inflammation and a potential role in IBD pathogenesis.

Methods

Caco-2 and HT-29 cells were grown in vitro to confluence on culture-permeable supports and then co-cultured with either TNF-α or OPG. After exposure to either TNF-α or OPG, interleukin (IL)-8 protein and mRNA levels were evaluated. Ussing chamber, western blotting, real-time polymerase chain reaction, and immunofluorescence were used to further investigate the effect of OPG on intestinal barrier integrity and function.

Results

Similar to TNF-α, treatment of monolayers with OPG caused increased monolayer permeability and diminished tight junction function and integrity, with loss of tight junction proteins from cell membranes. This was accompanied by elevated IL-8 protein and gene levels (P < 0.05). Western blotting also revealed that OPG, similar to TNF-α, induced NF-κB activation, as shown by inhibition of NF-κB kinase subunit-α phosphorylation.

Conclusions

These results indicate that OPG has pro-inflammatory properties because it induces gut barrier dysfunction and secretion of other pro-inflammatory cytokines. These results also provide evidence that OPG is likely to exert its pro-inflammatory effects through NF-κB activation and may potently contribute to IBD pathogenesis.     

A stringent preemptive protocol reduces cytomegalovirus disease in the first 6 months after kidney transplantation

Background

The optimal strategy to prevent cytomegalovirus (CMV) disease after kidney transplantation continues to be open to debate. The preemptive approach requires regular determination of CMV viremia and prompt initiation of therapy.

Methods

We retrospectively compared the incidence of CMV disease during two periods at our center: A first phase (P1, n?=?84 kidney recipients), during which time the intensity of surveillance was determined by the responsible physician, was compared to a second phase (P2, n?=?74), when a stringent protocol of CMV surveillance was required for all patients. The preemptive approach was applied for all CMV risk groups; prophylaxis was optional in the case of treatment for rejection or delayed graft function in the intermediate- and high-risk group. Follow-up was truncated at 6?months after transplant surgery. CMV syndrome was differentiated from asymptomatic replication by the presence of at least one systemic symptom, while diagnosis of CMV end-organ disease required histological confirmation.

Results

Immunosuppression was similar in the two periods. CMV prophylaxis was used equally (26?%) in both periods. The probability for asymptomatic viremia episodes was not different for patients in P1 and P2 regardless of the prevention strategy. For patients following the preemptive strategy, the probability for CMV disease was increased during P1 (p?=?0.016), despite fewer PCR assays being performed in phase 2. Protocol violations were only observed during P1.

Conclusions

The probability of CMV disease episodes (CMV syndrome and CMV end-organ disease) was substantially reduced using a very stringent protocol. This study highlights the crucial importance of a stringent protocol with optimal adherence by all caregivers if the preemptive strategy is to be successful.     

Presence of intestinal Mycobacterium avium subspecies paratuberculosis (MAP) DNA is not associated with altered MMP expression in ulcerative colitis

Background

Mycobacterium avium subspecies paratuberculosis (MAP) is suspected to be a causative agent in human Crohn's disease (CD). Recent evidence suggests that pathogenic mycobacteria and MAP can induce the expression of Matrix Metalloproteinases (MMP), which are the main proteases in the pathogenesis of mucosal ulcerations in inflammatory bowel disease (IBD). Within this study we assessed the prevalence of intestinal MAP specific DNA in patients with Crohn's disease, ulcerative colitis (UC), and healthy controls. We further analysed regulation patterns of MMPs in mucosal tissues of UC patients with and without intestinal MAP DNA detection.

Methods

Colonic biopsy samples were obtained from 63 Norwegian and German IBD patients and 21 healthy controls. RNA was quantified by quantitative real-time polymerase chain reaction (PCR) to study MMP gene expression in both pathological and healthy mucosal specimens. The presence of MAP DNA in colonic mucosa was examined using MAP specific PCR.

Results

MAP DNA was detected in 20% of UC patients and 33% of healthy controls but only in 7% of patients with CD. UC patients treated with corticosteroids exhibited a significantly increased frequency of intestinal MAP DNA compared to those not receiving corticosteroids. Expression of MMP-1, -2, -7, -9, -13, -19, -28 and TNF-α did not differ between UC patients with presence of intestinal MAP DNA compared to those without. MMP-2, MMP-9 and MMP-13 were significantly decreased in UC patients receiving corticosteroids.

Conclusions

The presence of intestinal MAP specific DNA is not associated with altered MMP expression in UC in vivo. Corticosteroids are associated with increased detection of intestinal MAP DNA and decreased expression of certain MMPs. Frequent detection of MAP DNA in healthy controls might be attributable to the wide environmental distribution of MAP and its presence in the food-chain.     

Clinical benefit of surgery for stage IV colorectal cancer with synchronous peritoneal metastasis

Background

Peritoneal metastasis is well-known as a poor prognostic factor in patients with colorectal cancer. It is important to improve the prognosis of patients with colorectal cancer and synchronous peritoneal metastasis. This study aimed to clarify the factors affecting R0 resection and the prognosis of colorectal cancer patients with synchronous peritoneal metastasis.

Methods

We investigated the data of patients with stage IV colorectal cancer between 1991 and 2007 in 16 hospitals that were members of the Japanese Society for Cancer of the Colon and Rectum.

Results

Of the 564 colorectal cancer patients with synchronous peritoneal metastases, 341 also had hematogenous metastases. The 5-year overall survival rates in patients with and without R0 resection were 32.4 and 4.7 %, respectively. A Cox proportional hazards model showed that histologic type of poorly differentiated adenocarcinoma, regional lymph node metastasis, liver metastasis, chemotherapy after surgery, R0 resection, the Japanese classification of peritoneal metastasis, and the size of peritoneal metastases were independent prognostic factors. Of the 564 patients, 28.4 % had R0 resection. The Japanese classification of peritoneal metastasis (P1–P2, p = 0.0024) and absence of hematogenous metastases (p < 0.0001) were associated with R0 resection.

Conclusions

P1–P2 peritoneal metastasis and the absence of hematogenous metastasis were the most favorable factors benefiting from synchronous resection of peritoneal metastasis. In addition, chemotherapy after surgery was essential.     

Combined probiotic bacteria promotes intestinal epithelial barrier function in interleukin-10-gene-deficient mice

AIM:To investigate the protective effects of combinations of probiotic(Bifico)on interleukin(IL)-10-genedeficient(IL-10 KO)mice and Caco-2 cell monolayers.METHODS:IL-10 KO mice were used to assess the benefits of Bifico in vivo.IL-10 KO and control mice received approximately 1.5×108 cfu/d of Bifico for 4 wk.Colons were then removed and analyzed for epithelial barrier function by Ussing Chamber,while an ELISA was used to evaluate proinflammatory cytokines.The colon epithelial cell line,Caco-2,was used to test the benefit of Bifico in vitro.Enteroinvasive Escherichia coli(EIEC)and the probiotic mixture Bifico,or single probiotic strains,were applied to cultured Caco-2 monolayers.Barrier function was determined by measuring transepithelial electrical resistance and tight junction protein expression.RESULTS:Treatment of IL-10 KO mice with Bifico partially restored body weight,colon length,and epithelial barrier integrity to wild-type levels.In addition,IL-10 KO mice receiving Bifico treatment had reduced mucosal secretion of tumor necrosis factor-αand interferon-γ,and attenuated colonic disease.Moreover,treatment of Caco-2 monolayers with Bifico or singlestrain probiotics in vitro inhibited EIEC invasion and reduced the secretion of proinflammatory cytokines.CONCLUSION:Bifico reduced colon inflammation in IL-10 KO mice,and promoted and improved epithelialbarrier function,enhanced resistance to EIEC invasion,and decreased proinflammatory cytokine secretion.     

The gastrointestinal electrical mapping suite (GEMS): software for analyzing and visualizing high-resolution (multi-electrode) recordings in spatiotemporal detail

Background

Intestinal hyper-permeability plays a critical role in the etiopathogenesis of inflammatory bowel disease (IBD) by affecting the penetration of pathogens, toxic compounds and macromolecules. 1,25-dihydroxyvitamin D₃ [1,25(OH)₂D₃], the active form of vitamin D, has been shown to be an important regulator of IBD and recent epidemiology suggests that patients with IBD have an impaired vitamin D status. The purpose of this study is to investigate the possible protective effects of 1,25(OH)₂D₃ on mucosal injury and epithelial barrier disruption on dextran sulfate sodium (DSS)-induced acute colitis model.

Methods

We used DSS-induced acute colitis model to investigate the protective effects of 1,25(OH)₂D₃ on mucosal injury and epithelial barrier integrity. Severity of colitis was evaluated by disease activity index (DAI), body weight (BW) change, colon length, histology, myeloperoxidase (MPO) activity, and proinflammatory cytokine production including tumor necrosis factor-?? (TNF-??) and interferon-?? (IFN-??). In vitro the protective role of 1,25(OH)₂D₃ was assessed by incubating Caco-2 cells with or without DSS and measuring transepithelial electrical resistance (TEER) and fluorescein isothiocyanate dextran (FITC-D). The intestinal permeability was analyzed by FITC-D, bacterial translocation and measurement of lipopolysaccharide (LPS). Ultrastructural features of the colon tissue and Caco-2 cell monolayer were observed by electron microscopy. Expressions of tight junction (TJ) proteins in the colon mucosa and Caco-2 cells were detected by immunohistochemistry, immunofluorescence, Western blot and real-time fluorescent quantitative PCR, respectively.

Results

DSS-induced acute colitis model was characterized by a reduced BW, AUC of BW, serum calcium, higher DAI, AUC of DAI, shortened colon length, elevated MPO activity, worsened histologic inflammation, increased mononuclear cell numbers in mesenteric lymph nodes (MLNs) and colonic lamina propria (LP), and enhanced proteins and mRNA levels of TNF-?? and IFN-??. 1,25(OH)₂D₃ markedly increased expressions of TJ proteins and mRNA and decreased the FITC-D permeability and the level of LPS. Furthermore, 1,25(OH)₂D₃ abrogated bacterial translocation to MLNs and ameliorated ultrastructural features of the colon epithelium by scanning electron microscopy (SEM). In vitro, 1,25(OH)₂D₃ increased TEER, TJ proteins and mRNA expressions, decreased the FITC-D permeability, and preserved structural integrity of the TJ in Caco-2 cells.

Conclusions

1,25(OH)₂D₃ may play a protective role in mucosal barrier homeostasis by maintaining the integrity of junction complexes and in healing capacity of the colon epithelium. 1,25(OH)₂D₃ may represent an attractive and novel therapeutic agent for the adjuvant therapy of IBD.     

Video-assisted anal fistula treatment (VAAFT) combined with advancement flap repair in Crohn’s disease

Background

It was the aim of this prospective study to analyze both the feasibility and preliminary results of video-assisted anal fistula treatment (VAAFT) combined with advancement flap repair for complex fistulas in Crohn's disease.

Methods

All patients with perianal Crohn's disease suffering from complex fistulas who underwent definitive surgery using VAAFT combined with advancement flap repair were prospectively enrolled in the study. Only complex fistulas with concurrent stable disease and without any evidence of severe inflammatory activity or perianal sepsis were treated using the VAAFT technique. Patients with Crohn's proctitis or prior proctectomy were not candidates for the procedure. VAAFT was performed by using the VAAFT equipment (Karl Storz, Tuttlingen, Germany). Key steps included visualization of the fistula tract and/or side tracts using the fistuloscope and correct localization of the internal fistula opening under direct vision with irrigation. Diagnostic fistuloscopy was followed by advancement flap repair. In addition to feasibility, primary end points included detection of side tracts, success and continence status (assessed by the Cleveland Clinic Incontinence Score). Success was defined as closure of both internal and external openings, absence of drainage without further intervention and absence of abscess formation. Follow-up information was derived from clinical examination 3, 6 and 9 months postoperatively.

Results

Within a 3-month observation period (September to November 2011), VAAFT was attempted in 13 patients with Crohn's associated complex fistulas. The completion rate was 85 % (11/13). In these 11 patients (median age 34 years, 64 % females), complex fistulas were transsphincteric (8), suprasphincteric (2) and recto-vaginal (1). Forty-six percent (5/11) had concomitant therapy with biologic drugs. In 36 % (4/11), VAAFT was performed with fecal diversion. Median duration of surgery was 22 (range 18–42) minutes. Using VAAFT, additional side tracts not detected preoperatively could be identified in 64 % (7/11). No morbidity occurred. After a mean follow-up of 9 months, the success rate was 82 % (9/11). No deterioration of continence was documented (Cleveland Clinic Incontinence Score 2.4 vs. 1.6, p > 0.05).

Conclusion

Preliminary results of the addition of the VAAFT technique to advancement flap repair in Crohn's fistulas demonstrate that this leads to a high identification rate of occult side tracts with encouraging short-term healing rates. Moreover, a completion rate of 85 % seems promising.     

The PSCA polymorphisms derived from genome-wide association study are associated with risk of gastric cancer: a meta-analysis

Purpose

Prostate stem cell antigen (PSCA) is a glycosylphosphatidylinositol-anchored 123-aa protein related to the cell-proliferation inhibition and/or cell-death induction activity. Many studies had reported the role of PSCA rs2294008 C?>?T and rs2976392 G?>?A polymorphisms on gastric cancer risk.

Methods

To investigate a more precise estimation of the relationships, we performed a meta-analysis on 9 case–control studies included 10,746 cases and 9,158 controls. Odds ratios (ORs) and 95?% confidence intervals (CIs) were used to assess the strength of the association.

Results

For PSCA rs2294008 C?>?T polymorphism, there was a significantly increased risk of gastric cancer in all genetic models (TT/TC vs. CC: OR?=?1.61, 95?% CI?=?1.35–1.91; TT vs. TC/CC: OR?=?1.33, 95?% CI?=?1.24–1.42). Similar results were also observed for PSCA rs2976392 G?>?A polymorphism (AA/AG vs. GG: OR?=?1.69, 95?% CI?=?1.24–2.31; AA vs. AG/GG: OR?=?1.36, 95?% CI?=?1.24–1.50). In the stratified analysis by ethnicity of rs2294008, an increased gastric cancer risk was found in both Asians (TT vs. TC/CC: OR?=?1.31, 95?% CI?=?1.22–1.42) and Europeans (TT/TC vs. CC: OR?=?1.42, 95?% CI?=?1.18–1.71). Furthermore, when stratified by clinicopathologic characteristics of tumor location and histology, a higher risk on non-cardia compared with cardia gastric cancer (TT vs. TC/CC: OR?=?1.43, 95?% CI?=?1.12–1.83) as same as diffused compared with intestinal gastric cancer (TT vs. TC/CC: OR?=?1.29, 95?% CI?=?1.13–1.49) was observed.

Conclusion

These findings supported that PSCA rs2294008 C?>?T and rs2976392 G?>?A polymorphisms may contribute to the susceptibility to gastric cancer, particular in non-cardia or diffused gastric cancer.     

Global microRNA expression profiles in insulin target tissues in a spontaneous rat model of type 2 diabetes

Aims/hypothesis

MicroRNAs regulate a broad range of biological mechanisms. To investigate the relationship between microRNA expression and type 2 diabetes, we compared global microRNA expression in insulin target tissues from three inbred rat strains that differ in diabetes susceptibility.

Methods

Using microarrays, we measured the expression of 283 microRNAs in adipose, liver and muscle tissue from hyperglycaemic (Goto–Kakizaki), intermediate glycaemic (Wistar Kyoto) and normoglycaemic (Brown Norway) rats (n?=?5 for each strain). Expression was compared across strains and validated using quantitative RT-PCR. Furthermore, microRNA expression variation in adipose tissue was investigated in 3T3-L1 adipocytes exposed to hyperglycaemic conditions.

Results

We found 29 significantly differentiated microRNAs (p _adjusted?<?0.05): nine in adipose tissue, 18 in liver and two in muscle. Of these, five microRNAs had expression patterns that correlated with the strain-specific glycaemic phenotype. MiR-222 (p _adjusted?=?0.0005) and miR-27a (p _adjusted?=?0.006) were upregulated in adipose tissue; miR-195 (p _adjusted?=?0.006) and miR-103 (p _adjusted?=?0.04) were upregulated in liver; and miR-10b (p _adjusted?=?0.004) was downregulated in muscle. Exposure of 3T3-L1 adipocytes to increased glucose concentration upregulated the expression of miR-222 (p?=?0.008), miR-27a (p?=?0.02) and the previously reported miR-29a (p?=?0.02). Predicted target genes of these differentially expressed microRNAs are involved in pathways relevant to type 2 diabetes.

Conclusion

The expression patterns of miR-222, miR-27a, miR-195, miR-103 and miR-10b varied with hyperglycaemia, suggesting a role for these microRNAs in the pathophysiology of type 2 diabetes, as modelled by the Gyoto–Kakizaki rat. We observed similar patterns of expression of miR-222, miR-27a and miR-29a in adipocytes as a response to increased glucose levels, which supports our hypothesis that altered expression of microRNAs accompanies primary events related to the pathogenesis of type 2 diabetes.     

Genetic variants of membrane metallopeptidase genes in inflammatory bowel diseases

Background

The substance P pathway modulates neuroimmune interactions during intestinal inflammation.

Aims

To analyse mucosal expression and genetic variants of the genes coding for substance P, neurokinin-1 receptor and neutral endopeptidase in patients with inflammatory bowel disease.

Methods

qRT-PCR was used to analyse mRNA levels in matched, paired samples of inflamed colonic mucosa and adjacent non-inflamed endoscopic tissue from 26 Crohn's disease and 25 ulcerative colitis patients. Allele and genotype frequencies of tag-SNPs were determined in 908 Crohn's disease, 929 ulcerative colitis, and 853 controls. Expression levels and genotype distributions were examined within patients’ clinical sub-phenotypes.

Results

All 3 evaluated genes were overexpressed in inflamed tissues from Crohn's disease (P = 0.033, P = 4 × 10⁻⁵, P = 0.001), while in ulcerative colitis only higher levels of the gene coding for neutral endopeptidase were statistically significant (P = 2.5 × 10⁻⁵). Smoking habit and perianal disease were significantly associated with substance P (P = 0.002) and neurokinin-1 receptor levels (P = 0.02) in Crohn's disease. Neutral endopeptidase rs701109 variant was associated with inflammatory bowel disease (Crohn's disease: P = 0.022; ulcerative colitis: P = 0.045), and with the need for colectomy in ulcerative colitis (P = 0.008, OR = 2.46, 95% CI = 1.27–4.76).

Conclusions

Genetic variants of the gene coding for neutral endopeptidase might affect the neuroimmune interaction during intestinal inflammation and influence clinical sub-phenotypes in patients with inflammatory bowel disease.     

Opioid Use is Associated with Decreased Quality of Life in Patients with Crohn's Disease

Background/Aims:

Quality of life is an important consideration in the management of patients with Crohn''s disease. Previous studies suggest that Crohn''s disease patients using opioids may have decreased quality of life and increased risk of mortality. Our aim was to determine the association between health-related quality of life (HRQoL) and opioid use in patients with Crohn''s disease while controlling for disease severity.

Patients and Methods:

We conducted a cross-sectional study recruiting Crohn''s disease patients at our center. Disease activity was measured using the Harvey-Bradshaw Index (HBI), and HRQoL was measured using the Inflammatory Bowel Disease Questionnaire (IBDQ).

Results:

We enrolled 38 Crohn''s disease patients using opioids and 62 patients not using opioids. Patients using opioids had an increased duration of disease (median 18.5 vs. 9 years, P = 0.005), increased surgeries related to Crohn''s disease (median 3 vs. 0, P < 0.001), and increased prednisone use (29% vs. 11.3%, P = 0.03). Patients using opioids had increased disease activity (median HBI score 9.0 vs. 3.0, P < 0.001). Quality of life was lower in patients using opioids (mean IBDQ score 109.3 vs. 162.9, P < 0.001). This finding was significant when controlling for HBI scores, number of previous surgeries, and prednisone use (P = 0.003).

Conclusions:

Opioid use in Crohn''s disease patients appears to be associated with disease activity and severity. HRQoL is markedly decreased in patients using opioids and this association is significant even when controlling for variables reflecting disease severity. Our findings suggest that Crohn''s disease patients using opioids are likely to be significantly impacted by their disease.