MDR1 C3435T polymorphism has no influence on developing Helicobacter pylori infection-related gastric cancer and peptic ulcer in Japanese

AIMS: P-glycoprotein, the gene product of multidrug-resistant transporter-1 (MDR1), confers multidrug resistance against antineoplastic agents but also affects the kinetic disposition of some drugs and carcinogens. MDR1 C3435T polymorphism influences the development of colon cancer and adult acute myeloid leukemia by the association with transporting carcinogen. The aim of this study was to clarify the association of MDR1 C3435T polymorphism with susceptibility to gastric cancer and peptic ulcers in patients with Japanese H. pylori infection. MAIN METHODS: We assessed the MDR1 C3435T polymorphism in H. pylori-positive gastritis alone patients (n=150), gastric cancer (n=292), gastric ulcer (n=215), and duodenal ulcer (n=163) and H. pylori-negative subjects (n=168) as control by a PCR-based method. KEY FINDINGS: No significant difference existed in frequencies of MDR1 C3435T polymorphisms between H. pylori-negative controls and H. pylori-positive gastritis alone patients. Moreover, MDR1-3435 T allele carriage didn't affect the risk of gastric cancer or peptic ulcer development. The age- and sex-adjusted odds ratios (ORs) of MDR1 3435 T allele carriers relative to the C/C genotype group for gastric cancer, gastric ulcer and duodenal ulcer risk were 0.96 (95%CI: 0.56-1.66), 1.16 (95%CI: 0.72-1.84) and 1.00 (95%CI: 0.61-1.62), respectively. SIGNIFICANCE: In this preliminary data, the association with MDR1 C3435T polymorphism and risk for developing H. pylori-related gastric cancer and peptic ulcer in Japanese was low. P-glycoprotein might not be involved in the carcinogenesis of H. pylori-related gastric cancer.     

Expression of heat shock protein 32 (hemoxygenase-1) in the normal and inflamed human stomach and colon: an immunohistochemical study

Heat shock protein 32 (Hsp32, hemoxygenase-1) is induced by reactive oxygen metabolites (ROM) and degrades heme leading to the formation of antioxidant bilirubin. Increased mucosal generation of ROM occurs in gastritis and inflammatory bowel disease. We aimed to assess mucosal expression of Hsp32 in normal stomach and colon and to test the hypothesis that disease-related differential expression occurs in inflamed tissue. Gastric body and antral mucosal biopsies were obtained from 33 patients comprising Helicobacter pylori-negative normal controls (n = 8), H pylori-negative gastritis patients (n = 11), and H pylori-positive gastritis patients (n = 14). Forty-seven archival colonic mucosal biopsies selected comprised normal histology (n = 10), active ulcerative colitis (UC) (n = 9), inactive UC (n = 8), active Crohn's disease (CD) (n = 8), inactive CD (n = 6), and other colitides (n = 6). Hsp32 expression in formalin-fixed sections was assessed by avidin-biotin peroxidase immunohistochemistry using a polyclonal rabbit anti-Hsp32 as the primary antibody. Immunohistochemical staining identified Hsp32 in all groups. Diffuse cytoplasmic staining was seen in gastric and colonic epithelial and lamina proprial inflammatory cells. Staining scores for Hsp32 were higher in antral H pylori-positive (P = 0.002) and H pylori-negative (P = 0.02) gastritis than in controls and in body H pylori-positive gastritis than in the other 2 groups (P < 0.01). Expression of Hsp32 was increased in active UC compared with inactive disease (P = 0.03) and normal controls (P = 0.02). In conclusion, Hsp32 is expressed constitutively in normal gastric and colonic mucosa, and differential expression occurs in these tissues when they are inflamed. Upregulation of Hsp32 may be an adaptive response to protect mucosa from oxidative injury in patients with gastritis and inflammatory bowel disease.     

Local and peripheral cytokine response and CagA status of Helicobacter pylori-positive patients with duodenal ulcer

The mucosal production of TNF-alpha, IL-6, IL-8, IL-10 and nitrotyrosine was investigated in H. pylori-positive patients with duodenal ulcer (DU). The concentrations of these cytokines in gastric antrum mucosal specimens from patients infected with H. pylori (n = 40) were determined by ELISA and compared with data on mucosal specimens from H. pylori-negative patients (n = 12). Nitrotyrosine was determined by ECL Western blotting. It was additionally investigated whether the tissue levels of the cytokines correlated with the peripheral cytokine levels, and the CagA status of the patients. The local TNF-a, IL-6 and IL-8 concentrations in the antral biopsy samples were significantly higher (p < 0.001) in the patients infected with H. pylori than in the samples from the H. pylori-negative subjects. There was a negative correlation between the TNF-alpha and IL-10 concentrations. Further more, in 23 of the 40 biopsy specimens, considerable nitrotyrosine production was detected by ECL Western blotting. There was no significant difference in peripheral TNF-a and IL-6 production between the DU patients and healthy blood donors (n = 100; 58% of whom were also H. pylori-positive). Only the in vitro IL-8-producing capacity was higher in the peripheral blood of the DU group after ex vivo induction with H. pylori. CagA positivity was demonstrated in 39 (97.5%) of the 40 patients with DU, and in 41 (70.7%) of the 58 H. pylori-positive, healthy blood donors. This study suggests that besides the bacterial virulence factor, the host response, with an increased mucosal production of inflammatory cytokines and reactive oxygen and nitrogen species could be relevant to the gastric pathophysiology in H. pylori-induced DU. There is no generalized cytokine overproduction in these DU patients, but the moderate increase in in vitro IL-8 production might be of pathophysiological importance.     

Helicobacter pylori-induced immunological responses in patients with duodenal ulcer and in patients with cardiomyopathies

The interaction between the bacteria and the host is a key factor determining the clinical consequences of H. pylori infection. The immune system plays an important role in either promoting or preventing the disease. The mucosal production of TNF-alpha, IL-6, IL-8 and IL-10 and the CagA status were investigated in H. pylori-positive patients with duodenal ulcer (DU). The concentrations of these cytokines in gastric antral mucosal specimens from patients infected with H. pylori (n = 40) were determined by ELISA and compared with data on mucosal specimens from H. pylori-negative patients (n = 12). The local TNF-alpha, IL-6 and IL-8 concentrations in the antral biopsy samples were significantly higher (p < 0.001) in the patients infected with H. pylori than in the samples from the H. pylori-negative subjects. CagA positivity was demonstrated in 39 (97.5%) of the 40 patients with DU, and in 41 (70.7%) of H. pylori-positive (58 of 100) healthy blood donors. In complementary studies focusing on extragastric disease, it was found that 57% of patients with ischaemic heart disease were seropositive as concerns H. pylori, and 91% of them had antibodies against human heat shock protein 60, too. This study suggests that, besides the bacterial virulence factor, the host response of an increased mucosal production of inflammatory cytokines can be relevant to the gastric pathophysiology in H. pylori-induced DU. At the same time, in ischaemic heart diseases the role of autoimmune processes induced by H. pylori cannot be excluded.     

The prevalence of peptic ulcer not related to Helicobacter pylori or non-steroidal anti-inflammatory drug use is negligible in southern Europe

BACKGROUND AND AIM: Helicobacter pylori is the major cause of peptic ulcer disease, but the proportion of H. pylori-negative peptic ulcers seems to be increasing in developed countries. We investigated the frequency of H. pylori-negative peptic ulcer without intake of nonsteroidal anti-inflammatory drugs (NSAIDs) in a Mediterranean European country. MATERIALS AND METHODS: We prospectively collected consecutive patients with an endoscopically verified active peptic ulcer over 6 months from different areas of Spain. Helicobacter pylori infection was assessed by rapid urease test and histologic examination (corpus and antral biopsies). A (13)C-urea breath test was performed if H. pylori was not detected with the invasive test. Patients were considered H. pylori-negative if all three tests were negative. NSAID use was determined by structured data collection. RESULTS: Of 754 consecutive peptic ulcer patients, 16 (2.1%) were H. pylori-negative and had not used NSAIDs before the diagnosis. Of the 472 patients who had duodenal ulcers, 95.7% (n = 452) were H. pylori-positive and only 1.69% (n = 8) were negative for both H. pylori infection and NSAID use; 193 patients had benign gastric ulcers and 87% (n = 168) of them were infected by H. pylori (p <.001 vs. duodenal ulcers). NSAID intake was more frequent in gastric ulcer patients (52.8%) than in duodenal ulcer patients (25.4%; p <.001). Consequently, the frequency of H. pylori-negative gastric ulcer in patients not using NSAID was 4.1% (n = 8). CONCLUSION: Peptic ulcer disease is still highly associated with H. pylori infection in southern Europe, and only 1.6% of all duodenal ulcers and 4.1% of all gastric ulcers were not associated with either H. pylori infection or NSAID use.     

Cytokine gene polymorphisms in gastric cancer patients from two Italian areas at high and low cancer prevalence

Polymorphisms of interleukin-1beta (IL-1beta), IL-1 receptor antagonist (IL1-RN), and tumor necrosis factor-alpha (TNF-alpha) genes are supposed to be key determinants of gastric cancer risk. Our aim was to study the association between these polymorphisms and gastric cancer in two areas characterized by high (Pavia/Bologna, North Italy) and low (San Giovanni Rotondo, South Italy) gastric cancer prevalence. Genomic DNA was obtained from 216 healthy donors and 98 gastric cancer patients from Pavia and Bologna, and 146 healthy donors and 86 gastric cancer patients from San Giovanni Rotondo. Two SNP in IL-1beta (-511 C/T) and TNF-alpha (-308 G/A) as well as the VNTR polymorphism of IL-1RN locus were studied. A significant linkage disequilibrium was found between IL-1beta -511 and IL-1RN. Genotype and allele frequencies at the IL-1beta, IL-1RN, and TNF-alpha loci in gastric cancer cases were not significantly different from controls. An epistatic effect between IL-1beta -511 and IL-1RN was found with the IL-1beta -511C/IL-1RN*2 haplotype conferring a significant protection against the intestinal-type of gastric cancer in the Southern population. In conclusion, IL-1beta, IL1-RN, and TNF-alpha genotypes are not associated with gastric cancer in Italian patients. An epistatic interrelationship between IL-1beta -511 and IL-1RN confers protection against gastric cancer in low-risk Italian population.     

Comparison of localized gastric mucosa-associated lymphoid tissue (MALT) lymphoma with and without Helicobacter pylori infection

BACKGROUND: The clinical features and clinical course of Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue (MALT) lymphoma are unclear and a treatment strategy has not yet been established. AIM: To clarify the clinical differences between H. pylori-positive and H. pylori-negative gastric MALT lymphoma, we compared these two types of gastric MALT lymphoma. MATERIALS AND METHODS: Fifty-seven patients with localized gastric MALT lymphoma were studied. H. pylori infection was present in 41 and absent in 16. Treatment consisted of antibiotic therapy and/or 30 Gy radiation therapy. Response assessment was performed every 3-6 months by esophagogastroduodenoscopy including gathering biopsy samples, endoscopic ultrasonography, clinical examination, and various imaging procedures. The median follow-up period was 37 months. RESULTS: There were no significant differences between H. pylori-positive and H. pylori-negative gastric MALT lymphoma patients in terms of sex, age, stage, gross phenotype, affected area of the stomach, or the presence of monoclonality. Complete regression was achieved with antibiotic therapy against H. pylori-negative gastric MALT lymphoma in one of nine patients (11.1%), compared to 28 of 38 patients (73.7%) with H. pylori-positive gastric MALT lymphoma (p < .001). Radiation therapy showed high effectiveness for the local control of H. pylori-negative or antibiotic-resistant gastric MALT lymphoma (92.9%), although distant recurrence was recognized in three of 14 patients (21.4%). Two of 16 patients (12.5%) with H. pylori-negative gastric MALT lymphoma died because of the transformation of the disease into diffuse large B-cell lymphoma. There was a significant difference in both the overall and cause-specific survival rate between the two groups (p = .038). CONCLUSION: Radiation therapy is the effective treatment for H. pylori-negative or antibiotic-resistant localized gastric MALT lymphoma. However, careful systemic follow-up for distant involvement should be required. Transformation into diffuse large B-cell lymphoma is thought to be the important cause of death in patients with gastric MALT lymphoma.     

Diethylmaleate and buthionine sulfoximine, glutathione-depleting agents, differentially inhibit expression of inducible nitric oxide synthase in endotoxemic mice.

Diethylmaleate (DEM) and buthionine sulfoximine (BSO), glutathione (GSH)-depleting agents, reduced the metabolic activity and the protein level of iNOS in both macrophages and hepatocytes activated by lipopolysaccharide (LPS). In this study, we examined the effects of DEM and BSO on iNOS expression in LPS-treated mice under the assumption that the level of GSH may alter the expression of nitric oxide synthase. Serum levels of interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) were also determined. DEM markedly decreased the levels of hepatic GSH in response to LPS. Treatment of mice with DEM significantly reduced serum nitrite/nitrate levels and hepatic iNOS protein and mRNA induction by LPS. Although BSO inhibited the level of hepatic GSH in LPS-treated mice, the agent did not alter serum nitrite/nitrate levels and hepatic iNOS expression. DEM completely inhibited an increase of serum IL-1beta level by LPS, whereas BSO failed to inhibit it. Neither DEM nor BSO significantly affected the induction of serum TNF-alpha level by LPS. These results showed that DEM and BSO differentially affect the expression of iNOS in endotoxemic mice, suggesting the possibility that suppression of iNOS expression by DEM may be associated with the inhibition of IL-1beta but not of TNF-alpha.     

E-cadherin gene promoter hypermethylation in H. pylori-induced enlarged fold gastritis

BACKGROUND: Promoter hypermethylation of E-cadherin plays an important role on gastric carcinogenesis. We have previously reported that the odds ratio for gastric carcinoma and the prevalence of diffuse-type early gastric carcinoma in Helicobacter pylori-induced enlarged fold gastritis increased with increasing fold width. Thus, we examined E-cadherin methylation in gastric mucosa from H. pylori-induced enlarged fold gastritis before and after H. pylori eradication. Moreover, we analyzed the mechanism of H. pylori infection-induced E-cadherin hypermethylation. MATERIALS AND METHODS: Twenty-three H. pylori-positive patients with enlarged folds, 18 H. pylori-positive and seven H. pylori-negative patients without enlarged folds, were involved in the study. E-cadherin promoter methylation was studied using quantitative methylation-specific polymerase chain reaction. We investigated methylation percentage and DNA methyltransferase activity in gastric cancer cell lines treated with EGF, TNFalpha, and MG132. RESULTS: E-cadherin methylation percentage of the gastric antral and body mucosa in H. pylori-positive patients with enlarged folds was much greater than that in both H. pylori-positive and -negative patients without enlarged folds. After H. pylori eradication, the methylation percentage in six patients with enlarged fold gastritis decreased significantly from 15.6 +/- 3.9 to 8.8 +/- 2.2 (p < .05). Moreover, the methylation was induced by TNFalpha, MG132, and EGF treatment, and DNA methyltransferase activity was induced by EGF treatment in MKN-1 cells. CONCLUSIONS: Our findings suggest that the hypermethylation of E-cadherin promoter might be involved in the process of gastric carcinoma through the specialized factors in H. pylori-induced enlarged fold gastritis.     

Involvement of endothelin-1 in up-regulation of gastric mucosal inflammatory responses to Helicobacter pylori lipopolysaccharide

In this study, we investigated gastric mucosal inflammatory responses during Helicobacter pylori lipopolysaccharide-induced gastritis by analyzing the interplay between mucosal expression of endothelin-1 (ET-1), interleukin-4 (IL-4) and tumor necrosis factor-alpha (TNF-alpha). The assays conducted 4 days after intragastric dose of H. pylori lipopolysaccharide demonstrated a pattern of acute mucosal reaction characterized by the inflammatory infiltration of the lamina propria, hyperemia, and epithelial hemorrhage. This was accompanied by a 3.1-fold increase in the mucosal expression of ET-1 and a 9-fold enhancement in TNF-alpha, while the level of IL-4 showed a 20.8% decline. The results implicate ET-1 in gastric mucosal responses to H. pylori, and suggest that an increase in its level, combined with a loss of compensatory action by IL-4, may be responsible for the induction of TNF-alpha and triggering apoptotic events that exacerbate the inflammatory process.     

Genetic polymorphism of interleukin-8 (IL-8) is associated with Helicobacter pylori-induced duodenal ulcer

BACKGROUND AND AIMS: Helicobacter pylori infection almost invariably causes chronic gastritis, but only a proportion of the infected subjects develop peptic ulcers. The local inflammation associated with H. pylori infection is characterized by an increased production of the proinflammatory cytokines IL-1-B, IL-6, IL-8 and TNF-alpha. Since such cytokine production is often determined by the genetic polymorphism of regions regulating cytokine gene expression, we investigated the relationship between TNF-alpha and IL-8 polymorphisms and the development of duodenal ulcer disease. We also sought a correlation between the promoter polymorphism of the lipopolysaccharide (LPS) receptor CD14 and the formation of peptic ulcer, because CD14 plays a crucial role in the initiation of the cytokine cascade. METHODS: Genomic DNA extracted from the peripheral blood of 69 patients with H. pylori-positive duodenal ulcer disease and 47 H. pylori-positive healthy controls was analyzed for TNF-alpha -308 promoter polymorphism by RFLP, and for IL-8 -251 polymorphism by ARMS. Genetic polymorphism within the promoter of the CD14 gene was identified using the LightCycler instrument via melting point analysis. RESULTS: No significant correlation could be revealed between the TNF-alpha and CD14 promoter polymorphisms and the clinical outcome of H. pylori infection. The IL-8 A/T heterozygote mutant variant was detected with a significantly higher frequency (65.22%) among the ulcer patients than among the healthy, H. pylori-positive blood donors (36.17%), while the frequency of the normal allelic genotype (TT) was significantly higher in the control group (44.6% vs 15.9%). CONCLUSION: Analysis of the genetic predisposition to enhanced cytokine production revealed a significant association only for the IL-8 polymorphism. This observation draws attention to the possible importance of IL-8 polymorphism as a genetic predisposing factor in the pathomechanism of H. pylori-induced duodenal ulcer disease, and to the relative protection from duodenal ulcer disease that is associated with the TT genotype.     

Postoperative changes in serum cytokines profile and nitric oxide levels in patients with cystic echinococcosis

The aim of the present study was to examine serum cytokines and nitric oxide (NO) levels in patients with cystic echinococcosis (CE). 28 patients with CE were studied and all underwent surgery. Serum levels of tumour necrosis factor-alpha (TNF-alpha), interleukin IL-1beta, receptor of soluble IL-2R (sIL-2R), IL-6, IL-8, nitrate/nitrite, and C-reactive protein (CRP) were determined before and after induction of treatment. Data were compared with those obtained from 28 healthy volunteers. IL-6 was elevated in all CE patients (100%). IL-8 was increased in 11/28 (39.3%). Increased levels of IL-2R and TNF-alpha were found in a limited number of them particularly those showing cysts in the central area of the liver (5/28, 6/28). IL-1beta level was not elevated in any patient except in secondary severe CE. CRP and nitrate/nitrite levels were also increased. A positive correlation between CRP and IL-6 (r = 0.74; p < 0.001) was found confirming the link between inflammation due to CE and activation of monocytes. All patients completely recovered and the levels of the studied parameters reverted to normal levels except one patient in whom severe recurrent disease occurred two years after the first operation. These results suggest that there are different immunoregulatory events and cytokines response during CE and may be in part related to slight monocytosis and in part to Th2 activation. IL-6, NO and CRP were unambiguously involved in the host parasite interaction and therefore may be useful markers in monitoring CE management and evaluating surgical stress.     

Release of tumour necrosis factor alpha into bronchial alveolar lavage fluid following antigen challenge in passively sensitized guinea-pigs

Five groups of ten female guinea-pigs were passively sensitized against ovalbumin (OA) (n = 9) or control guinea-pig serum (n = 1). 24 h later, they received mepyramine (0.5 mg/kg, i.p.) and 30 min later inhaled aerosols of: (A) OA (2 in 0.9% saline, 8 min, n = 4/9); (B) saline (40 min, n = 4/9); (C) LPS (40 min, Escherichia coli 0111:B4, 150 ng/kg in PBS, n = 1/9); and (D) the control animal was treated as in (C) (n = 1). Their tracheas were cannulated under pentobarbital anaesthesia and bronchial alveolar lavage (BAL) was performed with 2 x 5 ml PBS containing BSA (1%) (n = 1 group), or BSA (1%) and aprotinin (1000 KIU/ml) (n = 4 groups), at 30, 60, 90 or 120 min post-inhalations. BAL fluids recovered were centrifuged, the supernatants recovered and frozen until assayed for tumour necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1) and interleukin-6 (IL-6). No TNF-alpha could be detected unless aprotinin was present in the lavaging solution. BAL fluid from OA-sensitized and control animals that had inhaled LPS contained high levels of TNF-alpha that peaked at 90 min. BAL fluid from OA sensitized animals that inhaled OA aerosols contained no detectable TNF-alpha at 30 min, but it was found in increasing amounts at 60, 90 and 120 min; TNF-alpha was not detected in fluid from any of the animals that inhaled saline. As BAL fluids were toxic to the cells used in the assays, neither IL-1 nor IL-6 could be measured. We conclude that the monokine TNF-alpha is released into BAL fluid following anaphylactic challenge of passively sensitized guinea-pigs. The presence of the antiprotease, aprotinin, in the lavaging solution is essential for the detection and measurement of TNF-alpha in BAL fluid.     

Relationship between vitamin B12, folate and homocysteine levels and H. pylori infection in patients with functional dyspepsia: A cross-section study

ABSTRACT: BACKGROUND: H. pylori infection has been associated with many micronutrient deficiencies. There is a dearth of data from communities with nutritional deficiencies and high prevalence of H. pylori infection. The aim of this study was to determine the impact of H. pylori infection on serum levels of vitamin B12, folate and homocysteine in patients with functional dyspepsia (FD). METHODS: One hundred and thirty-two patients with FD undergoing gastroscopy were enrolled. The serum was analyzed for B12, folate and homocysteine levels before gastroscopy. H. pylori infection was diagnosed by histopathological examination of gastric biopsies and urea breath test. An independent sample t-test and the Mann-Whitney test were used to compare mean serum concentrations of biomarkers between H. pylori-positive and H. pylori-negative groups of patients. A Chi-square test was performed to assess the differences among proportions, while Spearman's rho was used for correlation analysis between levels of B12 and homocysteine. RESULTS: The mean age of the group was 40.3 +/- 11.5 (19-72) years. Folate deficiency was seen in 43 (34.6%), B12 deficiency in 30 (23.1%) and hyperhomocysteinemia in 60 (46.2%) patients. H. pylori was present in 80 (61.5%) patients with FD while it was absent in 50 (38.5%). Mean serum levels of B12, folate and homocysteine in the H. pylori-positive group of patients were not significantly different from the levels in the H. pylori-negative group (357 +/- 170 vs. 313 +/- 136 pg/mL; p = 0.13), (4.35 +/- 1.89 vs. 4.42 +/- 1.93 ng/mL; p = 0.84); (15.88 +/- 8.97 vs. 16.62 +/- 7.82 mumol/L; p = 0.24); respectively. B12 deficiency ([less than or equal to]200 pg/mL) was 23.8% in the H. pylori-positive patients versus 22.0% in the H. pylori-negative patients. Folate deficiency ([less than or equal to]3.5 ng/mL) was 33.8% in the H. pylori-positive group versus 36% in the H. pylori-negative group. Hyperhomocysteinemia (>15 mumol/L) was present in 46.2% of H. pylori-positive patients compared to 44% in the H. pylori-negative group. Correlation analysis indicated that serum B12 levels were inversely associated with serum levels of homocysteine in patients with FD (rho = 0.192; p = 0.028). CONCLUSIONS: This study demonstrated an inverse relationship between serum levels of B12 and homocysteine in patients with FD. Moreover, no impact of the presence of H. pylori was found on B12, folate and homocysteine levels in such patients.     

Comparative immunoproteomics of identification and characterization of virulence factors from Helicobacter pylori related to gastric cancer

Helicobacter pylori is an important risk factor of gastric cancer (GC). Although many H. pylori virulence factors have been reported, the pathogenic mechanism by which H. pylori infection causes GC remains unclear. The aims of this study were to identify GC-related antigens from H. pylori and characterize their roles in the development of GC. As GC and duodenal ulcer (DU) are considered clinically divergent, we compared two-dimensional immunoblots of an acid-glycine extract of H. pylori probed with serum samples from 15 patients with GC and 15 with DU to find GC-related antigens, which were subsequently identified by mass spectrometry. Many protein spots were recognized by more than one serum, and 24 of these were better recognized by GC sera. The proteins showing higher frequency of recognition in GC group are threonine synthase, rod shape-determining protein, S-adenosylmethionine synthetase, peptide chain release factor 1, DNA-directed RNA polymerase alpha subunit, co-chaperonin GroES (monomeric and dimeric forms), response regulator OmpR, and membrane fusion protein. Of these proteins, GroES was identified as a dominant GC-related antigen with a much higher seropositivity of GC samples (64.2%, n = 95) compared with 30.9% for gastritis (n = 94) and 35.5% for DU (n = 124). GroES seropositivity was more commonly associated with antral GC than with non-antral GC (odds ratio = 2.7; 95% confidence interval, 1.1-6.7). In peripheral blood mononuclear cells, GroES stimulated production of interleukin (IL)-8, IL-6, granulocyte macrophage colony-stimulating factor, IL-1beta, tumor necrosis factor-alpha, cyclooxygenase-2, and prostaglandin E(2). Moreover when incubated with gastric epithelial cells, GroES induced expression of IL-8, cell proliferation, and up-regulation of c-jun, c-fos, and cyclin D1 but caused down-regulation of p27(Kip1). We conclude that GroES of H. pylori is a novel GC-associated virulence factor and may contribute to gastric carcinogenesis via induction of inflammation and promotion of cell proliferation.     

Interleukin-2 gene polymorphisms associated with increased risk of gastric atrophy from Helicobacter pylori infection

BACKGROUND: Gastric atrophy induced by Helicobacter pylori is thought to predispose patients to noncardiac gastric cancer development. However, the host genetic factors that influence the progression of gastric atrophy have not been elucidated. In this study, we examined the effects of cytokine polymorphisms on H. pylori-induced gastric atrophy. METHODS: Blood samples were taken from 454 Japanese subjects. The interleukin-2 (IL-2; T-330G), IL-4 (C-33T), and IL-13 (C-1111T) polymorphisms were genotyped by polymerase chain reaction with confronting two-pair primers (PCR-CTPP). Anti-H. pylori IgG antibody and pepsinogen I and II were measured to diagnose H. pylori infection and atrophic gastritis. RESULTS: The odds ratios (ORs) for the association between IL-2 polymorphism [OR = 2.78, 95% CI (confidence interval) = 1.26-6.17 (T/T to G/G)] or IL-4 polymorphism [OR = 2.22, 95% CI = 1.01-4.89 (T/C to C/C)] were increased significantly with gastric atrophy, whereas the corresponding OR of IL-13 polymorphism was decreased with gastric atrophy [OR = 0.61, 95% CI = 0.39-0.96 (C/T and T/T to C/C)]. There were no significant H. pylori seropositivity-related differences between these polymorphisms. We examined the relationship between these polymorphisms and gastric atrophy separately in H. pylori-seropositive and -seronegative groups. In the H. pylori-seropositive group, the IL-2 T/T (OR = 2.78, 95% CI = 1.12-6.93) had a significant association with gastric atrophy. CONCLUSIONS: These results reveal that the IL-2 gene polymorphism is associated with an increased risk of gastric atrophy induced by H. pylori infection and might predispose to gastric cancer.     

Genetic polymorphisms of NOD1 and IL-8, but not polymorphisms of TLR4 genes, are associated with Helicobacter pylori-induced duodenal ulcer and gastritis

BACKGROUND: Intracellular pathogen receptor NOD1 is involved in the epithelial cell sensing Helicobacter pylori, which results in a considerable interleukin (IL)-8 production. The aim of this study was to evaluate the relationship between NOD1 and IL-8 genetic polymorphisms and the development of H. pylori-induced gastritis and duodenal ulcer (DU), as compared with TLR4 polymorphisms. MATERIALS AND METHODS: Eighty-five patients with DU and 135 patients with gastritis were enrolled in the study. Seventy-five serologically H. pylori-positive subjects without gastric or duodenal symptoms served as controls. The G796A (E266K) NOD1 polymorphism was determined by restriction fragment length polymorphism, and the -251 IL-8 polymorphism by amplification refractory mutation system method. The TLR4 (ASP/299/Gly and Thr/399/Ile) gene polymorphisms were examined by melting point analysis. RESULTS: AA homozygote mutant variants of NOD1 were detected in 20% of the H. pylori-positive patients with DU versus 7% of H. pylori-positive patients with gastritis and versus 6% of the H. pylori-positive healthy controls. The IL-8 heterozygote mutant variant was detected with a significantly higher frequency among the DU patients and those with gastritis than among the H. pylori-positive controls. However, no significant correlation concerning the frequency of the TLR4 gene polymorphism could be revealed between any group of patients and the controls. CONCLUSION: E266K CARD4/NOD1, but not the TLR4 gene polymorphism increases the risk of peptic ulceration in H. pylori-positive patients. The -251 IL-8 polymorphism was significantly associated with either gastritis or DU in H. pylori-infected subjects. Host factors including intracellular pathogen receptors and IL-8 production play an important role in H. pylori-induced gastric mucosal damage.     

Apoptosis in different gastric lesions and gastric cancer: relationship with Helicobacter pylori, overexpression of p53 and aneuploidy

Apoptosis has an essential function in maintaining the integrity of the gastrointestinal mucosa. Its deregulation is associated with the occurrence of lesions such as in atrophic gastritis, peptic ulcers, intestinal metaplasia, and stomach tumorigenesis. Thus, the aim of the present study was to investigate the frequency of apoptotic cells (apoptotic index, AI) by using two different immunohistochemical techniques, TUNEL and anti-activated caspase-3 antibody (CPP32), in gastric dyspepsia [chronic gastritis (CG, N = 34), chronic atrophic gastritis (CAG, N = 11), gastric ulcer (GU, N = 17), and intestinal metaplasia (IM, N = 15)], normal gastric mucosae (NM, N = 8), and gastric adenocarcinoma (GC, N = 12). The relationship was investigated between the AI and Helicobacter pylori infection, diagnosed by PCR, overexpression of p53 protein determined by immunohistochemistry, and aneuploidy by fluorescence in situ hybridization, as performed by our laboratory in previous studies. No significant differences were observed in AI between the different groups, whether by the TUNEL technique (F = 1.60; p = 0.1670) or by CPP32 antibody (F = 1.70; p = 0.1420). Nonetheless, CAG and CG groups had AI statistically higher than those of normal mucosae. These two groups (CAG and CG) also showed a higher frequency of apoptosis-positive cases (TUNEL+ or CPP32+). Generally, there was no correlation between the AI detected by the TUNEL and CPP32 techniques in the groups studied, except in the GC group (r = 0.70). Moreover, there was no significant association between apoptosis and H. pylori infection, overexpression of p53 protein and aneuploidy, but the H. pylori-positive cases only of GU (p = 0.0233) and IM (p = 0.0253) groups displayed a statistically higher AI compared to H. pylori-negative NM, when the CPP32 antibody technique was used. Thus, CG and CAG have increased apoptosis, which may occur independent of an association with H. pylori infection, aneuploidy and overexpression of p53 protein.     

Helicobacter pylori stimulates a mixed adaptive immune response with a strong T-regulatory component in human gastric mucosa

BACKGROUND: Host factors play an important role in the pathophysiology of Helicobacter pylori infection and development of gastritis and related disease. The established opinion is that the T-cell-mediated immune response to H. pylori infection is of Th1 type. Our earlier immune cell phenotype studies indicate a mixed Th1-Th2 profile of the effector cells. Therefore, an extensive adaptive and regulatory cytokine gene expression profile was conducted by quantitative real-time polymerase chain reaction (qPCR). MATERIALS AND METHODS: Biopsies from gastric mucosa of 91 patients diagnosed as H. pylori negative, H. pylori positive with gastritis, or H. pylori positive with peptic ulcer were obtained by endoscopy. Gene expressions of nine cytokines and CagA status were measured by qPCR. RESULTS: All cytokine genes showed higher expression levels in the presence of H. pylori when compared to H. pylori-negative samples (fold increase: IL8: x 11.2; IL12A: x 2.4; TNF-alpha: x 5.2; IFN-gamma: x 4.3; IL4: x 3.6; IL6: x 14.7; and IL10: x 6.7). Patients infected with CagA-positive strains had higher expression of IL1-beta and IL18 compared to patients infected with CagA-negative strains (x 1.6 for IL1-beta and x 2.0 for IL18). Patients with duodenal ulcer had a lower antral Th1/Th2 ratio than other H. pylori-positive patients. CONCLUSIONS: The cytokine profile of H. pylori-infected gastric mucosa shows a mixed Th1-Th2 profile. Furthermore, a high IL10 expression may indicate that also regulatory T cells play a role in the chronic phase of H. pylori infection.     

Epithelial cell kinetics of the gastric mucosa during Helicobacter pylori infection

Helicobacter pylori is an important pathogen in major gastroduodenal diseases, including inflammation with ulceration and gastric malignancies. Alterations in H. pylori associated cell turnover in gastric epithelial cells are examined in relation to inflammatory activity, bacteria load and cytokines which may improve knowledge concerning the outcome of gastric diseases caused by H. pylori. Antral biopsies from 42 dyspeptic patients including 27 H. pylori-positive and 15 H. pylori-negative patients were tested for apoptotic activity by the TUNEL assay, and immuno-histochemically for p53 and the proliferative marker Ki-67. H. pylori infection, bacteria load and inflammatory activity were associated with increased cell turnover as judged by enhanced activities of TUNEL, p53 and Ki-67. Only p53 was significantly correlated to IFN-gamma, IL-8 and IL-10. The H. pylori-positive state was furthermore accompanied by varying degrees of altered distribution pattern of the markers studied, with occasional presence of apoptosis in the deeper pit zones, upward extension of Ki-67 and to a lesser degree of p53. Given a similar pattern of change in proliferation and apoptosis in some neoplastic lesions in other parts of the gastrointestinal tract, such studies in cell turnover may provide insights valuable in the investigations of potential precursors of gastric malignancies.