The Effect of Helicobacter pylori on Epidermal Growth Factor Receptor-Induced Signal Transduction and the Preventive Effect of Celecoxib in Gastric Cancer Cells

Background/Aims

Helicobacter pylori infection induces cyclooxygenase-2 (COX-2) and epidermal growth factor receptor (EGFR) overexpression, and these factors may engage in cross-talk. The aim of the present study was to evaluate the effect of H. pylori on EGFR signaling pathways and to determine whether celecoxib has an inhibitory effect on this pathway.

Methods

The AGS cell line was cocultured with H. pylori G27 and the isogenic cagE- mutant. The expression of COX-2, EGFR, heparin binding-epidermal growth factor (HB-EGF), and transforming growth factor-β (TGF-β) was measured by real time-polymerase chain reaction (RT-PCR). Next, Western blot analyses of COX-2, EGFR, total Akt, phosphorylated Akt (pAkt), and phosphorylated glycogen synthase kinase-3β (pGSK3β) were performed after incubating H. pylori-treated AGS cells for 24 hours with various concentrations of celecoxib (0, 10, 20, and 30 µmol/L).

Results

H. pylori infection upregulated the mRNA levels of COX-2, EGFR, HB-EGF, and TGF-β, as detected by RT-PCR. However, AGS cells treated with cagE- mutants, which have a defective type IV secretion system, did not exhibit EGFR upregulation. Celecoxib had inhibitory effects on the H. pylori-induced overexpression of COX-2 (p=0.015), EGFR (p=0.025), pAkt (p=0.025), and pGSK3β (p=0.029) by Western blot analysis.

Conclusions

H. pylori with an intact type IV secretion system activated the COX-2 and EGFR-Akt pathways in the AGS cell line. As celecoxib exhibited inhibitory effects on the EGFR signaling pathway, the cross-talk of COX-2 and EGFR likely mediates H. pylori-induced gastric cancer.     

Effect of Helicobacter pylori and its Virulence Factors on Portal Hypertensive Gastropathy and Interleukin (IL)-8, IL-10, and Tumor Necrosis Factor-alpha Levels

Background/Aim:

We aimed to assess the influence of Helicobacter pylori and its virulent factors, cytotoxin associated gene (cag) A and E, on portal hypertensive gastropathy (PHG) and the levels of interleukin (IL)-8, IL-10, and tumor necrosis factor-alpha (TNF-α).

Patients and Methods:

The patients with cirrhosis underwent screening endoscopy and the lesions related to PHG were graded. Biopsies were obtained for histology, and polymerase chain reaction (PCR) of H. pylori 16S rRNA, cagA, cagE, and tissue cytokine levels was carried out. Absent or mild PHG was compared with moderate to severe PHG.

Results:

One hundred and forty patients with cirrhosis were studied; males numbered 92 and the mean age of the patients was 50.3 ± 12.0 years, H. pylori positivity in 87 (62.1%) patients was associated with male gender (P = 0.032), younger age (P = 0.029), hepatitis D etiology (P = 0.005), higher serum albumin (0.000), lower Child Pugh score (P = 0.001), and lower portal vein diameter (P = 0.001). There was no significant difference in the levels of TNF-α and IL-8. However, a decrease in the anti-inflammatory cytokine IL-10 was noted with moderate to severe gastropathy. Four H. pylori strains were positive for both cagA and cagE, while four were positive for cagA only. All the four patients with both virulent factors had mild gastropathy only.

Conclusion:

The presence of H. pylori infection neither affected the severity of PHG nor augmented the IL-8 and TNF-α levels. There was a decline of virulent H. pylori strains and IL-10 levels in patients with advanced PHG.     

Asiatic acid inhibits cardiac hypertrophy by blocking interleukin-1β-activated nuclear factor-κB signaling in vitro and in vivo

Background

Activated interleukin (IL)-1β signaling pathway is closely associated with pathological cardiac hypertrophy. This study investigated whether asiatic acid (AA) could inhibit IL-1β-related hypertrophic signaling, and thus suppressing the development of cardiac hypertrophy.

Methods

Transverse aortic constriction (TAC) induced cardiac hypertrophy in C57BL/6 mice and cultured neonatal cardiac myocytes stimulated with IL-1β were used to evaluate the role of AA in cardiac hypertrophy. The expression of atrial natriuretic peptide (ANP) was evaluated by quantitative polymerase chain reaction (qPCR) and the nuclear factor (NF)-κB binding activity was measured by electrophoretic mobility shift assays (EMSA).

Results

AA pretreatment significantly attenuated the IL-1β-induced hypertrophic response of cardiomyocytes as reflected by reduction in the cardiomyocyte surface area and the inhibition of ANP mRNA expression. The protective effect of AA on IL-1β-stimulated cardiomyocytes was associated with the reduction of NF-κB binding activity. In addition, AA prevented TAC-induced cardiac hypertrophy in vivo. It was found that AA markedly reduced the excessive expression of IL-1β and ANP, and inhibited the activation of NF-κB in the hypertrophic myocardium.

Conclusions

Our data suggest that AA may be a novel therapeutic agent for cardiac hypertrophy. The inhibition of IL-1β-activated NF-κB signaling may be the mechanism through which AA prevents cardiac hypertrophy.     

Symmetric Dimethylarginine as a Proinflammatory Agent in Chronic Kidney Disease

Summary

Background & objectives

Chronic kidney disease (CKD) is characterized by chronic inflammation, considered a nontraditional risk factor for cardiovascular disease, the major cause of death in CKD. Symmetric dimethylarginine (SDMA) was recently demonstrated to induce reactive oxygen species in monocytes. The present study further investigates the inflammatory character of SDMA compared with its structural counterpart asymmetric dimethylarginine (ADMA).

Design, setting, participants, & measurements

In vitro, the effect of SDMA on intracellular monocytic expression of IL-6 and TNF-α was studied followed by an evaluation of nuclear factor (NF)–κB activation. Additionally, an association of SDMA with inflammatory parameters in consecutive stages of CKD was evaluated in vivo.

Results

Monocytes incubated with SDMA showed increased IL-6 and TNF-α expression and a rise in active NF-κB. N-acetylcysteine abrogated both these effects. No significant effects were observed with ADMA. In vivo, 142 patients (67 ± 12 years) at different stages of CKD showed an inverse association between serum SDMA and ADMA and renal function. Correlations between SDMA and IL-6, TNF-α, and albumin were more significant than for ADMA, while multiple regression analysis only retained TNF-α at a high significance for SDMA (P < 0.0001). In receiver operating characteristic analysis for inflammation, defined as an IL-6 level above 2.97 pg/ml (median), the discriminative power of SDMA (area under the curve [AUC]: 0.69 ± 0.05) directly followed that of C-reactive protein (AUC: 0.82 ± 0.04) and albumin (AUC: 0.72 ± 0.05; for all, P < 0.0001) and preceded that of ADMA (P = 0.002).

Conclusions

The present study shows that SDMA is involved in the inflammatory process of CKD, activating NF-κB and resulting in enhanced expression of IL-6 and TNF-α, which is corroborated by the clinical data pointing to an in vivo association of SDMA with inflammatory markers in CKD at different stages.     

Effects of radix curcumae-derived diterpenoid C on Helicobacter pylori-induced inflammation and nuclear factor kappa B signal pathways

AIM:To study effect of diterpenoid C extracted from radix curcumae on Helicobacter pylori(H.pylori)-infected inflammation,intestinal metaplasia,and nuclear factor kappa B(NF-κB)signaling pathway in vitro.METHODS:We used I-type H.pylori to infect human gastric epithelial gastric epithelium cell line(GES-1)cell lines,and then H.pylori-infected GES-1 cells were treated with radix curcumae(RC)-derived diterpenoid C of different concentrations(5,10,20μg/mL)and amoxicillin.The expression of p65,IκB kinase(IKK)αand IKKγproteins was detected with Western blotting,and the expression of interleukin(IL)-8,IL-6 and IL-4 was determined with enzyme-linked immunosorbent assay method.Data were analyzed using SPSS software ver18.0.For comparisons between groups of more than two unpaired values,one-way analysis of variance(ANOVA)was used.If an ANOVA F value was significant,post hoc comparisons were performed between groups.If results were not normally distributed,the Mann-Whitney U test was used to compare two groups of unpaired values,whereas for comparisons between groups of more than two unpaired values,the Kruskal-Wallis H test was used.Statistical significance was established at P<0.05.RESULTS:The MTT assay results revealed the inhibited rate of GES-1,and indicated that the IC5 of RCderived diterpenoid C and amoxicillin all were 5μg/mL for gastric GES-1 cells.The expression of IL-8 was significantly increased,especially at 12 h time point;and the expression of IL-4 was decreased in H.pyloriinfected GES-1 cells.After H.pylori-infected GES-1 cells were treated with RC-derived diterpenoid C of different concentrations and amoxicillin,the expression of IL-8was decreased at 12,24,48,72 h points(P<0.01),especially in high-concentration diterpenoid C(20μg/mL)group;and the expression of IL-4 was increased,especially in moderate and high-concentration diterpenoid C(10 and 20μg/mL)groups.RC-derived diterpenoid C had the inhibitory effects on H.pylori-induced p65 translocation from cytoplasm into cell nucleus,H.pylori-sti     

Sero-prevalence and factors associated with Helicobacter pylori infection in Eastern Sudan

Objective

To investigate the prevalence of Helicobacter pylori (H. pylori) among patients with dyspepsia and to evaluate the correlation between H. pylori infection and socio-demographic factors.

Methods

This cross-sectional hospital-based study, which ran from June to August 2012, determined seroprevalence of H. pylori among adult patients in Eastern Sudan. The presence of H. pylori was determined using ELISA.

Results

A total of 225 adult Sudanese patients were enrolled in the study. Of these, 148 (65.8%) tested positive for H. pylori. In logistic regression analysis, rural residency (OR=3.933, CI=1.337-11.26, P=0.01) was the only socio-demographic factor that was associated with H. pylori infection. The most common symptoms among seropositive patients were heartburn (OR=30.442, CI=9.478-97.776, P≤0.001) and/or epigastria pain (OR=28.225, CI=4.365-182.508, P≤0.001).

Conclusions

Clinical suspicion can facilitate the detection of H. pylori among patients with dyspeptic symptoms in a geographic area with high prevalence of H. pylori infection.     

The Effects of Broccoli Sprout Extract Containing Sulforaphane on Lipid Peroxidation and Helicobacter pylori Infection in the Gastric Mucosa

Background/Aims

The aims of this study were to investigate whether a broccoli sprout extract containing sulforaphane (BSES) inhibited the Helicobacter pylori infection density and exerted an antioxidative effect on gastric mucosal damage.

Methods

The enrolled subjects were randomized in a double-blinded manner into three groups. Finally, 33 H. pylori (+) BSES treatment subjects (group A), 28 H. pylori (+) placebo subjects (group B), and 28 H. pylori (−) BSES treatment subjects (group C) were studied. H. pylori infection density was indirectly quantified by a ¹³C-urea breath test (UBT), and the ammonia concentration in gastric juice aspirates was measured through gastroscopic examination. Malondialdehyde (MDA), an oxidative damage biomarker, and reduced glutathione (GSH), an antioxidant biomarker, were measured in the gastric mucosa by an enzyme-linked immunosorbent assay.

Results

BSES treatment did not significantly affect the UBT values or ammonia concentration in group A (p=0.634 and p=0.505, respectively). BSES treatment did significantly reduce mucosal MDA concentrations in group A (p<0.05) and group C (p<0.001), whereas the gastric mucosal GSH concentrations did not differ before and after treatment in any of the groups.

Conclusions

BSES did not inhibit the H. pylori infection density. However, BSES prevented lipid peroxidation in the gastric mucosa and may play a cytoprotective role in H. pylori-induced gastritis.     

Substitutions in Penicillin-Binding Protein 1 in Amoxicillin-Resistant Helicobacter pylori Strains Isolated from Korean Patients

Background/Aims

A worldwide increase in amoxicillin resistance in Helicobacter pylori is having an adverse effect on eradication therapy. In this study, we investigated the mechanism of the amoxicillin resistance of H. pylori in terms of amino acid substitutions in penicillin-binding protein 1 (PBP1).

Methods

In total, 150 H. pylori strains were isolated from 144 patients with chronic gastritis, peptic ulcers, or stomach cancer. The minimum inhibitory concentrations (MICs) of the strains were determined with a serial 2-fold agar dilution method. The resistance breakpoint for amoxicillin was defined as >0.5 µg/mL.

Results

Nine of 150 H. pylori strains showed amoxicillin resistance (6%). The MIC values of the resistant strains ranged from 1 to 4 µg/mL. A PBP1 sequence analysis of the resistant strains revealed multiple amino acid substitutions: Val16→Ile, Val45→Ile, Ser414→Arg, Asn562→Tyr, Thr593→Ala, Gly595→Ser, and Ala599→Thr. The natural transformation of these mutated genes into amoxicillin-sensitive strains was performed in two separate pbp1 gene segments. A moderate increase in the amoxicillin MIC was observed in the segment that contained the penicillin-binding motif of the C-terminal portion, the transpeptidase domain.

Conclusions

pbp1 mutation affects the amoxicillin resistance of H. pylori through the transfer of the penicillin-binding motif.     

Development of an ELISA for Quantitative Detection of Immunoglobulin G (IgG) and IgA Antibodies to Helicobacter pylori for Use in Korean Patients with H. pylori-Associated Diseases

Background/Aims

We aimed to develop a quantitative enzyme-linked immunosorbent assay (ELISA) using whole-cell lysates of Helicobacter pylori 51 and to investigate its validity.

Methods

Data from 300 plates were obtained by two different operators. Standard sera were used to make a standard curve to analyze the quantity of anti-H. pylori immunoglobulin G (IgG) and IgA antibody. We obtained reproducible data with fewer dilutions of samples by the addition of serially diluted standard serum to each ELISA plate. To evaluate the validity of this ELISA, the 114 H. pylori-positive and -negative subjects were stratified into four age groups, i.e., 0 to 4, 5 to 9, 10 to 15, and 20 to 29 years, before testing.

Results

The mean IgG-antibody titers in H. pylori-positive and -negative subjects were 1,766.4 IU/mL and 654.3 IU/mL (p<0.001). The mean IgA-antibody titers in H. pylori-positive and -negative subjects were 350.1 IU/mL and 193.5 IU/mL (p<0.001). Anti-H. pylori IgG and IgA titers in the four age groups were higher in H. pylori-positive subjects than in H. pylori-negative subjects (p<0.05).

Conclusions

Using the current ELISA based on whole-cell lysates of H. pylori 51, reliable anti-H. pylori antibody titers were obtained regardless of the subject''s age.     

Do we eradicate Helicobacter pylori in hospitalized patients with peptic ulcer disease?

BACKGROUND:

Helicobacter pylori infection is the most common chronic infection in humans. It is a major contributor to the cause of duodenal and gastric ulcers worldwide. Its eradication has been shown to reduce rates of H pylori-related ulcers as well as other complications such as gastric cancer.

OBJECTIVE:

To determine the rate of appropriate treatment in patients following a diagnosis of H pylori infection on biopsy during esophagoduodenoscopy for upper gastrointestinal bleeding over a four-year period at a tertiary centre in Vancouver, British Columbia. Also evaluated was the rate of eradication confirmation using the urea breath test.

METHODS:

A retrospective review of 1501 inpatients who underwent esophagoduodenoscopy for upper gastrointestinal bleeding (January 2006 to December 2010) was undertaken. Patients who were biopsy stain positive for H pylori were selected for drug review either via a provincial database (PharmaNet) or via records from patients’ family practitioners. Data were also obtained via two provincial laboratories that perform the urea breath test to determine the rates of confirmation of eradication.

RESULTS:

Ninety-eight patients had biopsy-proven H pylori. The mean (± SD) age was 56.13±17.9 years and 65 were male. Data were not available for 22 patients; the treatment rate was 52.6% (40 of 76). Of those treated, 12 patients underwent a post-treatment urea breath test for eradication confirmation.

CONCLUSION:

There was substantial discrepancy between the number of diagnosed H pylori infections and the rate of treatment as well as confirmation of eradication. Numerous approaches could be taken to improve treatment and eradication confirmation.     

Relationship between the Extent of DNA Damage and Gastritis in Normal and Helicobacter pylori-Infected Patients

Background/Aims

The role of Helicobacter pylori in gastric carcinogenesis is unclear, but H. pylori infection is thought to predispose carriers to gastric cancer. The aim of this study was to investigate the relationship between the extent of DNA damage in normal gastric epithelial cells and H. pylori-positive and -negative gastritis according to histological diagnosis. We also compared the percentage of cometed cells on the surface of the gastric epithelial cells to the percentage beneath the gastric mucosal cells using serial incubations times.

Methods

The comet assay is a rapid, efficient and reproducible measure of DNA damage in single cell and it was used in this study. DNA damage was evaluated in 52 cases using alkaline single cell gel electrophoresis (comet assay). Comparisons were made between 19 normal individuals, 19 patients with H. pylori-positive and -negative gastritis and 14 mixed cases with different histology gradings to determine if there was a relationship between histological diagnosis and DNA damage (comet percentage).

Results

The comet percentages in specimens from cases with normal histology were significantly higher than the comet percentages in specimens from cases with H. pylori-positive gastritis. In addition, there was a significant increase in the percentage of cometed cells on the surface of gastric epithelial cells in both normal and H. pylori-infected cells compared to the subsequent gastric cell layers of the same specimen.

Conclusions

A relationship between the comet percentage and the histological diagnosis was observed.     

Sero-prevalence of Helicobacter pylori infection among asymptomatic healthy Omani blood donors

Objective

To investigate the prevalence of Helicobacter pylori (H. pylori) infection, a cross-sectional epidemiological study, based on the age and gender-specific seroprevalence of H. pylori antibodies in asymptomatic healthy Omani blood donors attending the SQUH blood bank.

Methods

Analysis of the sera from 133 apparently healthy subjects, based on the serological determination of the IgM, IgG and IgA antibodies against H. pylori, was carried out using a commercially available kit ELISA (NovaLisa, NovaTec, Germany). While the presence of H. pylori-specific IgG antibodies is the marker for a “chronic” infection with this pathogen. Therefore, there was no indicator of the time of acquisition of the infection. However, the H. pylori-specific IgM antibody was a more specific marker for a recently acquired infection with H. pylori.

Results

Of the 133 subjects, there were 100 (74%) males and 33 (26%) females. The age range was 15 to 50 years with a mean of 25.75±3.75 years. The overall prevalence of H. pylori infection in our study was 69.5%. The overall seroprevalence was found to be increased 69%-86% with age. Subjects between 15–20 years of age showed 71% seroprevalence, while those between 21–40 years showed gradual increase (63%–70%) with age and reached up to 87% in subjects between 41–50 years of age. A significant inverse association was found between sex and age groups. This is when each age group was examined individually; a higher positive percentage of H. pylori antibodies increasing with age was seen in males between 21–40 years of age group in comparison to the females of the same age group. Male subjects with age group between 21 to 40 years were found to have a significant seropositivity compared to the female subjects within the same group. This may reflect how frequent were the male subjects being exposed to the outer environment and their conduct than the females in this society like Oman.

Conclusions

The seropositivity of H. pylori is moderately higher between ages of 21 to 30 more than any other age group.     

Seroprevalence of Helicobacter pylori Infection in Korean Health Personnel

Background/Aims

The aims of this study were to evaluate whether doctors and nurses in a single hospital were at an increased risk of acquiring Helicobacter pylori infection in 2011 and to identify risk factors for H. pylori seroprevalence.

Methods

Nurses (n=362), doctors (n=110), health personnel without patient contact (medical control, n=179), and nonhospital controls (n=359) responded to a questionnaire during a health check-up, which included questions on socioeconomic status, education level, working years, and occupation in 2011. The prevalence of H. pylori was measured by serology.

Results

The seroprevalence rate was 29.8% (nurses), 34.5% (doctors), 30.7% (medical control), and 52.9% (nonhospital control). Among younger subjects (<40 years of age), the nonhospital control had a higher seropositivity rate (48.1%) than nurses (29.2%), doctors (29.8%), and the medical control (24.8%), which was not observable in subjects ≥40 years of age. The risk factors for H. pylori seroprevalence were not different for health and nonhealth personnel. A multivariate analysis indicated that seropositivity significantly increased with age, the province of residence, and a gastroscopic finding of a peptic ulcer.

Conclusions

The medical occupation was not associated with H. pylori infection. The seroprevalence of H. pylori in one hospital in 2011 was found to be 38.7%, most likely due to the improvement in socioeconomic status and hospital hygiene policy in Korea.     

Effects of baicalin in CD4 + CD29 + T cell subsets of ulcerative colitis patients

AIM: To evaluate the role of baicalin in ulcerative colitis (UC) with regard to the CD4⁺CD29⁺ T helper cell, its surface markers and serum inflammatory cytokines.METHODS: Flow cytometry was used to detect the percentage of CD4⁺CD29⁺ cells in patients with UC. Real time polymerase chain reaction was used to detect expression of GATA-3, forkhead box P3, T-box expressed in T cells (T-bet), and retinoic acid-related orphan nuclear hormone receptor C (RORC). Western blotting was used to analyze expression of nuclear factor-κB (NF-κB) p65, phosphorylation of NF-κB (p-NF-κB) p65, STAT4, p-STAT4, STAT6 and p-STAT6. The concentrations of interferon-γ (IFN-γ), interleukin (IL)-4, IL-5, IL-6, IL-10 and TGF-β in serum were determined by ELISA assay.RESULTS: The percentages of CD4⁺CD29⁺ T cells were lower in treatment with 40 and 20 μmol/L baicalin than in the treatment of no baicalin. Treatment with 40 or 20 μmol/L baicalin significantly upregulated expression of IL-4, TGF-β1 and IL-10, increased p-STAT6/STAT6 ratio, but downregulated expression of IFN-γ, IL-5, IL-6, RORC, Foxp3 and T-bet, and decreased ratios of T-bet/GATA-3, p-STAT4/STAT4 and p-NF-κB/NF-κB compared to the treatment of no baicalin.CONCLUSION: The results indicate that baicalin regulates immune balance and relieves the ulcerative colitis-induced inflammation reaction by promoting proliferation of CD4⁺CD29⁺ cells and modulating immunosuppressive pathways.     

Does Helicobacter pylori Exacerbate Gastric Mucosal Injury in Users of Nonsteroidal Anti-Inflammatory Drugs? A Multicenter,Retrospective, Case-Control Study

Background/Aims

The interaction between nonsteroidal anti-inflammatory drugs (NSAIDs) and Helicobacter pylori remains controversial. We retrospectively investigated whether H. pylori infection exacerbates severe gastric mucosal injury among chronic NSAID users.

Methods

From January 2010 to December 2013, a total of 245 long-term NSAID (including low-dose aspirin) users who had undergone an esophagogastroduodenoscopy and had been evaluated for H. pylori infection were enrolled at Okayama University Hospital and Tsuyama Chuo Hospital. The degree of gastric mucosal injury was assessed according to the modified Lanza score (MLS). Severe gastric mucosal injury was defined as an MLS ≥4. Univariate and multivariate logistic regression analyses were performed.

Results

In the univariate analysis, age ≥75 years (odds ratio [OR], 2.4; 95% confidence interval [CI], 1.3 to 4.2), H. pylori-positivity (OR, 2.0; 95% CI, 1.2 to 3.5), and the concomitant use of proton pump inhibitors (PPIs) (OR, 0.48; 95% CI, 0.26 to 0.86) were significantly associated with severe gastric mucosal injury. The multivariate analysis was adjusted by age and sex and demonstrated that H. pylori-positivity (OR, 1.8; 95% CI, 1.0 to 3.3) and the concomitant use of PPIs (OR, 0.53; 95% CI, 0.28 to 0.99) significantly contributed to severe gastric mucosal injury.

Conclusions

H. pylori infection exacerbates severe gastric mucosal injury among chronic NSAID users.