Association of interleukin 1 gene family polymorphisms with duodenal ulcer disease

Association of the functionally significant polymorphisms of the MMP9 gene with H. pylori-positive gastric ulcer in the Caucasian population of Central Russia

Background and purpose

The study analyzed the association of functionally significant polymorphisms of matrix metalloproteinases (MMPs) genes with the development of gastric ulcer (GU) in Caucasians from Central Russia.

Methods

The 781 participants, including 434 patients with GU (196 Helicobacter pylori (H. pylori)-positive and 238 H. pylori-negative) and 347 controls (all H. pylori-negative) were recruited for the study. Ten SNPs of the MMP1 (rs1799750), MMP2 (rs243865), MMP3 (rs679620), MMP8 (rs1940475), and MMP9 (rs3918242, rs3918249, rs3787268, rs17576, rs17577, and rs2250889) genes were considered for association with GU using multiple logistic regression. The SNPs associated with GU and loci linked (r²≥0.8) to them were analyzed in silico for their functional assignments.

Results

The SNPs of the MMP9 gene were associated with H. pylori-positive GU: alleles C of rs3918249 (OR = 2.02, p_perm = 0.008) and A of rs3787268 (OR = 1.60–1.82, p_perm ≤ 0.016), and eight haplotypes of all studied MMP9 gene SNPs (OR = 1.85–2.04, p_perm ≤ 0.016) increased risk for H. pylori-positive GU. None of the analyzed SNPs was independently associated with GU and H. pylori-negative GU. Two haplotypes of the MMP9 gene (contributed by rs3918242, rs3918249, rs17576, and rs3787268) increased risk for GU (OR = 1.62–1.65, p_perm ≤ 0.006). Six loci of the MMP9 gene, which are associated with H. pylori-positive GU, and 65 SNPs linked to them manifest significant epigenetic effects, have pronounced eQTL (17 genes) and sQTL (6 genes) values.

Conclusion

SNPs of the MMP9 were associated with H. pylori-positive GU but not with H. pylori-negative GU in Caucasians of Central Russia.

Functionally significant polymorphisms of the MMP-9 gene are associated with peptic ulcer disease in the Caucasian population of Central Russia

This study analyzed the association of functionally significant SNPs of matrix metalloproteinase (MMP) genes in the development of peptic ulcer disease (PUD) in Caucasians from Central Russia. Ten SNPs of the MMP-1, MMP-2, MMP-3, MMP-8, and MMP-9 genes were analyzed for association with PUD in a cohort of 798 patients with PUD (including 404 H. pylori-positive and 394 H. pylori-negative) and 347 H. pylori-negative controls using logistic regression and assuming the additive, recessive, and dominant genetic models. The variants of MMP-1, MMP-2, MMP-3, and MMP-8 did not manifest any significant associations with the diseases. Five SNPs of the MMP-9 gene demonstrated such association. Allele G of the rs17576 MMP-9 locus conferred a higher risk for PUD (OR_adj = 1.31, p_perm = 0.016), haplotype AACG of loci rs17576-rs3787268-rs2250889-rs17577 of the MMP-9 gene decreased risk for PUD (OR_adj = 0.17, p_perm = 0.003). Also, allele C of rs3918249, allele G of rs17576 and haplotype CG of rs3918249-rs17576 of the MMP-9 gene increased risk for H. pylori-positive PUD (OR_adj = 1.82, p_perm = 0.002; OR_adj = 1.53–1.95 p_perm = 0.001–0.013 and OR_adj = 1.49 p_perm = 0.009 respectively). The above loci and 50 linked to them possess significant regulatory effects and may affect the alternative splicing of four genes and the expression of 17 genes in various organs and tissues related to the PUD pathogenesis.

Genetic polymorphisms associated with upper gastrointestinal bleeding: a systematic review

Non-variceal upper gastrointestinal bleeding (non-variceal UGIB) is a frequent and severe adverse drug reaction. Idiosyncratic responses due to genetic susceptibility to non-variceal UGIB has been suggested. A systematic review was conducted to assess the association between genetic polymorphisms and non-variceal UGIB. Twenty-one publications and 7134 participants were included. Thirteen studies evaluated genetic polymorphism in patients exposed to non-steroidal anti-inflammatory drugs, low-dose aspirin, and warfarin. Eight studies present at least one methodological problem. Only six studies clearly defined that the outcome evaluated was non-variceal UGIB. Genetic polymorphisms involved in platelet activation and aggregation, angiogenesis, inflammatory process, and drug metabolism were associated with risk of non-variceal UGIB (NOS3, COX-1; COX-2; PLA2G7; GP1BA; GRS; IL1RN; F13A1; CDKN2B-AS1; DPP6; TBXA2R; TNF-alpha; VKORC1; CYP2C9; and AGT). Further well-designed studies are needed (e.g., clear restriction to non-variceal UGIB; proper selection of participants; and adjustment of confounding factors) to provide strong evidence for pharmacogenetic and personalized medicine.

The association between interleukin polymorphism and recurrent aphthous stomatitis: A meta-analysis

OBJECTIVE

To assess the association between interleukin gene polymorphism and recurrent aphthous stomatitis (RAS).

DESIGNS

Two electronic databases, PubMed and Embase, were utilized to assemble potentially relevant studies meeting the inclusion criteria. A meta-analysis was conducted using Revman 5.3 software (London, UK), and the pooled odds ratio (OR) and 95% confidence interval (CI) were then used to evaluate the strength of the relationship between the gene polymorphisms of IL-1beta(-511C/T), IL-1beta(+3954C/T), IL-6(-174G/C) and IL-10(-1082G/A) and the risk of RAS.

RESULTS

Ten studies were included in the final meta-analysis, with 884 cases and 1104 controls participating. The results demonstrated that the polymorphism of IL-1beta(-511C/T) significantly increased the probability of the development of RAS in Europeans. (T vs. C: OR = 1.35, 95%CI = 1.09-1.67; CC vs. CT + TT: OR = 1.77, 95%CI = 1.24-2.53; CC vs. TT: OR = 1.86, 95%CI = 1.18-2.95). Furthermore, the C allele in IL-1beta(+3954C/T) was determined to be related to the risk of RAS in Americans (C vs. T: OR = 1.52, 95%CI = 1.07-2.17) and the presence of the C gene was considered a risk variant (CC + CT vs. TT: OR = 1.46, 95%CI = 1.01-2.11), but no relationship was found between the polymorphism of IL-10(-1082G/A) and the risk of RAS.

CONCLUSIONS

The meta-analysis suggested that the mutation of IL-1beta(-511C/T) in Europe and IL-1beta(+3954C/T) in America tend to increase the risk of RAS, but the polymorphism of IL-10(-1082G/A) appears to have no association with RAS risk in America. Further study is required to confirm the above conclusions.

Non-variceal upper gastrointestinal bleeding

Non-variceal upper gastrointestinal bleeding (NVUGIB) is bleeding that develops in the oesophagus, stomach or proximal duodenum. Peptic ulcers, caused by Helicobacter pylori infection or use of NSAIDs and low-dose aspirin (LDA), are the most common cause. Although the incidence and mortality associated with NVUGIB have been decreasing owing to considerable advances in the prevention and management of NVUGIB over the past 20 years, it remains a common clinical problem with an annual incidence of ∼67 per 100,000 individuals in the United States in 2012. NVUGIB is a medical emergency, and mortality is in the range ∼1-5%. After resuscitation and initial assessment, early (within 24 hours) diagnostic and therapeutic endoscopy together with intragastric pH control with proton pump inhibitors (PPIs) form the basis of treatment. With a growing ageing population treated with antiplatelet and/or anticoagulant medications, the clinical management of NVUGIB is complex as the risk between gastrointestinal bleeding events and adverse cardiovascular events needs to be balanced. The best clinical approach includes identification of risk factors and prevention of bleeding; available strategies include continuous treatment with PPIs or H. pylori eradication in those at increased risk of developing NVUGIB. Treatment with PPIs and/or use of cyclooxygenase-2-selective NSAIDs should be implemented in those patients at risk of NVUGIB who need NSAIDs and/or LDA.

Peptic ulcer disease

The rapidly declining prevalence of Helicobacter pylori infection and widespread use of potent anti-secretory drugs means peptic ulcer disease has become substantially less prevalent than it was two decades ago. Management has, however, become more challenging than ever because of the threat of increasing antimicrobial resistance worldwide and widespread use of complex anti-thrombotic therapy in the ageing population. Peptic ulcers not associated with H pylori infection or the use of non-steroidal anti-inflammatory drugs are now also imposing substantial diagnostic and therapeutic challenges. This Seminar aims to provide a balanced overview of the latest advances in the pathogenetic mechanisms of peptic ulcers, guidelines on therapies targeting H pylori infection, approaches to treatment of peptic ulcer complications associated with anti-inflammatory analgesics and anti-thrombotic agents, and the unmet needs in terms of our knowledge and management of this increasingly challenging condition.

Challenges of deciphering gastric cancer heterogeneity

Gastric cancer is in decline in most developed countries; however, it still accounts for a notable fraction of global mortality and morbidity related to cancer. High-throughput methods are rapidly changing our view and understanding of the molecular basis of gastric carcinogenesis. Today, it is widely accepted that the molecular complexity and heterogeneity, both inter- and intra-tumour, of gastric adenocarcinomas present significant obstacles in elucidating specific biomarkers for early detection of the disease. Although genome-wide sequencing and gene expression studies have revealed the intricate nature of the molecular changes that occur in tumour landscapes, the collected data and results are complex and sometimes contradictory. Several aberrant molecules have already been tested in clinical trials, although their diagnostic and prognostic utilities have not been confirmed thus far. The gold standard for the detection of sporadic gastric cancer is still the gastric endoscopy, which is considered invasive. In addition, genome-wide association studies have confirmed that genetic variations are important contributors to increased cancer risk and could participate in the initiation of malignant transformation. This hypothesis could in part explain the late onset of sporadic gastric cancers. The elaborate interplay of polymorphic low penetrance genes and lifestyle and environmental risk factors requires additional research to decipher their relative impacts on tumorigenesis. The purpose of this article is to present details of the molecular heterogeneity of sporadic gastric cancers at the DNA, RNA, and proteome levels and to discuss issues relevant to the translation of basic research data to clinically valuable tools. The focus of this work is the identification of relevant molecular changes that could be detected non-invasively.

To be or not to be: The host genetic factor and beyond in Helicobacter pylori mediated gastro-duodenal diseases

Helicobacter pylori (H. pylori) have long been associated with a spectrum of disease outcomes in the gastro-duodenal system. Heterogeneity in bacterial virulence factors or strains is not enough to explain the divergent disease phenotypes manifested by the infection. This review focuses on host genetic factors that are involved during infection and eventually are thought to influence the disease phenotype. We have summarized the different host genes that have been investigated for association studies in H. pylori mediated duodenal ulcer or gastric cancer. We discuss that as the bacteria co-evolved with the host; these host gene also show much variation across different ethnic population. We illustrate the allelic distribution of interleukin-1B, across different population which is one of the most popular candidate gene studied with respect to H. pylori infections. Further, we highlight that several polymorphisms in the pathway gene can by itself or collectively affect the acid secretion pathway axis (gastrin: somatostatin) thereby resulting in a spectrum of disease phenotype

Associations of a TLR4 single-nucleotide polymorphism with H. pylori associated gastric diseases in Iranian patients

OBJECTIVE

Helicobacter pylori (H. pylori) is associated with gastric ulcer and gastric adenocarcinoma. Polymorphisms in the host genes coding for toll-like receptors (TLRs) may influence the innate and adaptive immune response to the infection, affecting the susceptibility to H. pylori or the disease outcomes. But the details and association to different polymorphisms and different clinical expressions in patients infected with H. pylori (different clinical expression of H. pylori infection) remain unclear.

METHODS

A case-control study consisting of 195 patients with H. pylori infection and 241 H. pylori uninfection was conducted. Genomic DNA was extracted and genotypes of TLR4Asp299Gly polymorphism were assessed through polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Presence of cagA was evaluated using PCR.

RESULTS

TLR4 (Asp299Gly) G and DG alleles frequency in H. pylori infected population was significantly higher in the chronic gastritis group than in the chronic active gastritis group (P=0.021; OR, 2.409; 95% CI, 1.124-5.162). Grade mononuclear (MN) infiltration in H. pylori infected patients with DG genotype of TLR-4 Asp299Gly increased significantly. CagA positivity was more frequently associated with chronic active gastritis (P=0.017, OR=2.26, 95% CI=1.144-4.462) and grade polymorphonucler (PMN) infiltration.

CONCLUSION

TLR-4 Asp299Gly G allele substitution may be modified pattern of immune response in the gastric mucosa of H. pylori infected patients and may be H. pylori infected patients with gastritis have increased risk for the development of chronic gastritis. CagA positivity may be a risk factor for development of gastritis.

Chronic gastric ulceration causes matrix metalloproteinases-9 and -3 augmentation: alleviation by melatonin

Matrix metalloproteinases (MMPs) are a family of zinc-dependent enzymes capable of degradation of extracellular matrix (ECM) and key player in various inflammatory diseases. We investigated the regulation of MMPs in chronic gastric ulceration in mice. We generated chronic gastric ulcers in mice by indomethacin and examined the activity and expression of MMP-9 and -3 in stomach. Melatonin (N-acetyl-5-methoxytryptamine) treatment has also been applied to mice to characterize the changes in expression and activities of MMPs in gastric tissues. We observed significant upregulation of MMP-9 and -3 expressions and activities in stomach with increasing doses and duration of indomethacin that corroborated with increased activity of activator protein (AP)-1. Substantial damage in gastric epithelial layer was found during chronic ulceration. Melatonin suppressed MMP-9 and -3 expressions and activities during prevention and healing of chronic gastric ulcers. It also suppressed protein oxidation, lipid peroxidation and antioxidant enzymes. Additionally, expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-8 was significantly high in ulcerated stomachs while melatonin treatment blocked them to control level. We found elevated phosphorylation of extracellular-regulated kinase (ERK)1/2 and c-Jun N-terminal kinase (JNK) during chronic gastric ulceration, which were significantly reversed by melatonin. Moreover, expression of NF-κB, c-fos and c-jun were inhibited by melatonin resulting down regulation of MMP-9 and -3 expressions. In summary, oxidative stress is preceded by chronic inflammation that enhances the expression of MMP-9 and -3, while melatonin arrests both of them via reduction of AP-1 activity during protection of ulcer.

No association between IL-1β -31 C/T polymorphism and the risk of duodenal ulcer: a meta-analysis of 3793 subjects

The aim of this study was to perform a meta-analysis to investigate a more authentic association between IL-1β -31 C/T polymorphism and duodenal ulcer (DU). Systematic searches of electronic databases Embase, PubMed and Web of Science were performed. Study selection, data abstraction and study quality evaluation were independently conducted in duplicate. Statistical analyses were conducted using software Stata 11.0. The pooled odds ratios (ORs) with 95% confidence intervals (95%CIs) were applied. Publication bias was tested by Begg's funnel plot and Egger's regression test. A total of 12 studies including 1151 cases and 2642 controls were included in our final meta-analysis. There was no evidence of significant association between IL-1β -31 C/T polymorphism and DU (allelic model: OR=0.96, 95%CI=0.86-1.07; additive model: OR=0.85, 95%CI=0.67-1.07; dominant model: OR=0.95, 95%CI=0.81-1.13; and recessive model: OR=0.95, 95%CI=0.79-1.15). Significant association was found in additive model for PB subgroup (OR=0.65, 95%CI=0.44-0.96) and recessive model for non-Asian subgroup (OR=0.72, 95%CI=0.52-0.99). In conclusion, our meta-analysis suggested that there was no evidence of significant association between IL-1β -31 C/T polymorphism and DU with or without Helicobacter pylori infection in overall population, whereas significant association was found by subgroup analyses which showed protective effect of C/C genotype against DU risk.

No association between IL-1β -511 C/T polymorphism and the risk of duodenal ulcer: a meta-analysis of 4667 subjects

Epidemiological studies have evaluated the association between IL-1β -511 C/T polymorphism and duodenal ulcer (DU) risk. However, the results remain conflicting. The aim of this study was to perform a meta-analysis to investigate a more authentic association between IL-1β -511 C/T polymorphism and DU. Systematic searches of electronic databases Embase, PubMed and Web of Science as well as hand searching of the references of identified articles and the meeting abstracts were performed. Study selection, data abstraction and study quality evaluation were independently conducted in duplicate. Statistical analyses were performed using software Stata 11.0. The pooled odds ratios (ORs) with 95% confidence intervals (95% CIs) were performed. Publication bias was tested by Begg's funnel plot and Egger's regression test. A total of 14 studies including 1887 cases and 2780 controls were included in our final meta-analysis. There was no evidence of significant association between IL-1β -511 C/T polymorphism and DU (for T allele vs. C allele: OR=0.93, 95% CI=0.82-1.06; for T/T vs. C/C: OR=0.83, 95% CI=0.64-1.08; for dominant model: OR=0.93, 95% CI=0.80-1.07; and for recessive model: OR=0.87, 95% CI=0.69-1.11). Significant association was found in all genetic models for the PB subgroup and sensitivity analyses. In conclusion, our meta-analysis suggests that there was no evidence of a significant association between IL-1β -511 C/T polymorphism and DU with or without Helicobacter pylori infection, whereas a significant association was found by sensitivity analyses which showed a protective effect of the T allele against DU risk.

IL-1 polymorphisms in children with peptic symptoms in South China

BACKGROUND

Polymorphisms of IL-1 gene cluster are reported to be associated with histological changes and IL-1β expression in the gastric mucosa in adults, especially in Helicobacter pylori-infected subjects. As H. pylori infecting adults and children own different virulence genotypes, the aim of this study was to investigate whether IL-1 polymorphisms are risk factors in young children in South China.

MATERIALS AND METHODS

A total of 128 children with peptic symptoms were enrolled in this study. Polymorphisms of IL-1B-511 and IL-1B-31 were identified by dual fluorescence PCR. Variable number of tandem repeat region in IL-1RN was detected by conventional PCR and IL-1β mRNA expression by real-time PCR ddCT assay.

RESULTS

IL-1B-31T and IL-1B-511C were completely linked in this study. Significant differences of IL-1B-511/-31 genotypes were observed among different clinical outcomes (p = .001). The IL-1B-511TT/-31CC was mostly found in the moderate gastritis and the above (severe gastritis or gastric ulcer) groups, with percentage of 60.7%. While no association was observed between IL-1RN genotypes and the gastric mucosal histological changes (p = .128). Also no relationships were found between IL-1 polymorphisms and H. pylori infection or gastric mucosal IL-1β mRNA expression level.

CONCLUSION

Children with IL-1B-511TT/-31CC may have a risk to develop relatively severe gastric mucosal histological changes in South China.

Association of IL1B -511C/-31T haplotype and Helicobacter pylori vacA genotypes with gastric ulcer and chronic gastritis

Background

The association between proinflammatory cytokine gene polymorphisms and gastric diseases related to Helicobacter pylori varies by population and geographic area.

Our objective was to determine if the IL-1B -511 T>C and -31 C>T polymorphisms and H. pylori vacA genotypes are associated with risk of chronic gastritis and gastric ulcer in a Mexican population.

Methods

We conducted endoscopic studies in 128 patients with symptoms of dyspepsia. We took two biopsies from the body, antrum, or ulcer edge from each patient, and classified our histopathological findings according to the Sydney System. H. pylori infection and vacA genotyping were accomplished via PCR from total DNA of the gastric biopsies. We confirmed the presence of anti-H. pylori serum IgG and IgM in 102 control subjects. In both case subjects and control subjects, the IL-1B -511 T>C polymorphism was genotyped by PCR-RFLPs and the IL-1B -31 C>T polymorphism was genotyped by pyrosequencing.

Results

Sixty-two point seven (62.7%) of the 102 control subjects were H. pylori-seropositive. Among the case subjects, 100 were diagnosed with chronic gastritis and 28 with gastric ulcer. We found that 77% of the patients with chronic gastritis and 85.7% of the patients with gastric ulcer were H. pylori-positive. The predominant H. pylori genotype was vacA s1m1 (58.4%) and the most frequent subtype was vacA s1. The -511 TC, (rs16944 -511 T>C) genotype and the -511C allele were associated with chronic gastritis (OR = 3.1, 95% CI = 1.4-6.8 and OR = 3.0, 95% CI = 1.4-6.0, respectively). The subjects carrying -31T (rs1143627 -31 C>T) were found to be at a higher risk of having chronic gastritis (OR = 2.8, 95% CI = 1.3-5.8). The IL-1B -511C/-31T haplotype was associated with chronic gastritis (OR = 2.1, 95% CI = 1.2-3.8) but not with gastric ulcer.

Conclusions

The H. pylori vacA genotypes identified herein were similar to those reported for other regions of Mexico. The vacA s1m1 genotype was not associated with gastric ulcer. In the southern Mexican population, the IL-1B -511C and -31T alleles and the -511C/-31T and -511T/-31T haplotypes are associated with increased risk of chronic gastritis and gastric ulcer.

Association between interleukin-1 beta polymorphism (+3953) and obesity

It now appears that obesity is associated with a low-grade inflammation of white adipose tissue resulting from chronic activation of the innate immune system as interleukin-1 beta (IL-1). Previous investigations have described a positive association between IL-1 beta +3953 (C>T) gene polymorphism (rs 1143634) and obesity, suggesting functional effects on fat mass, fat metabolism and body mass. However, it is necessary to determine if these results occur in other populations and if they are influenced by sex and age. Therefore, we performed a case-control study using 880 Caucasian subjects (59.7+/-11.9 years old) from the Brazilian Aging Research Program (non-overweight=283, overweight=334, obese=263) previously investigated in genetic studies, in whom we analyzed the IL-1 beta +3953C/T polymorphism. We observed higher T allele (CT/TT) frequency in non-overweight than overweight and obese groups. The odds ratio showed 1.340 (95% CI: 1.119-1.605) times more chance of the obese group being CC carriers compared to non-overweight group independent of sex and age. This study corroborates the idea that the IL-1 system is linked to the development of obesity.

Interleukin-1 beta single-nucleotide polymorphism's C allele is associated with elevated risk of gastric cancer in Helicobacter pylori-infected Peruvians

Particular alleles of the interleukin-1B (IL-1B) gene have been correlated with increased risk of atrophic gastritis and gastric cancer in the populations of East Asia and Europe. No such data exist from Peru, a developing country with a population genotypically different from others studied and with a high prevalence of Helicobacter pylori infection and gastric cancer. We conducted a case-control study comparing 334 hospitalized patients with atrophic gastritis or gastric cancer with 158 nonatrophic gastritis patients (controls). Conditional logistic regression analysis revealed that an increased risk of atrophic gastritis (odds ratio, 5.60) and gastric cancer (odds ratio, 2.36) was associated with the IL-1B-511 C allele. Our study is the first to establish this allele as a risk for these conditions. Given the high prevalence of H. pylori and recurrence rate after treatment, IL-1B-511 single-nucleotide polymorphism analysis may identify those individuals who would benefit most from robust H. pylori eradication efforts in Peru.

Immune reactions against elongation factor 2 kinase: specific pathogenesis of gastric ulcer from Helicobacter pylori infection

Helicobacter pylori (H. pylori) infection is a definite causative factor for gastric ulcers (GUs). In the present study we detected a specific antigen of gastric epithelial cells (HGC-27) using cell ELISA, which was recognized by the sera of GU patients (n = 20) but not in patients with chronic gastritis (CG; n = 20) or in healthy volunteers (HC; n = 10). This antigen was over-expressed by a stressful (heat-stressed) environment, and was identified as elongation factor 2 kinase (EF-2K) by western blotting. The GU patients' lymphocytes stimulated by H. pylori specifically disrupted heat-stressed HGC-27 cells in a cytotoxic assay. In flow cytometry, the effector cells (lymphocytes) from GU patients were significantly differentiated to T helper type 1 lymphocyte (Th1) and cytotoxic T lymphocyte (CTL) as opposed to those from CG patients. The target cells (HGC-27) expressed EF-2K and MHC-class I together with costimulatory molecules from heat stress. This antigen specific immune mechanism could have a prominent role in the pathogenesis of GU.

The effects of genetic polymorphisms of IL-6, IL-8, and IL-10 on Helicobacter pylori-induced gastroduodenal diseases in Korea

BACKGROUND

The genes that encode proinflammatory and anti-inflammatory cytokines are good candidate markers of host susceptibility to gastroduodenal disease. The present study was performed to evaluate whether or not the genetic polymorphisms of IL-6, IL-8, and IL-10 are associated with gastroduodenal disease in the Korean population.

METHODS

This study enrolled 1187 patients, including controls, those with gastric cancer (GC), benign gastric ulcer (BGU), and duodenal ulcer patients. Six polymorphisms were genotyped, 3 of IL-10 (at -592, -819, and -1082), 1 of IL-8 (at -251), and 2 of IL-6 (at -174 and -572), by polymerase chain reaction-restriction fragment length polymorphism analysis.

RESULTS

The frequency of IL-10-1082 G carriers was higher in cases of a diffuse type GC [odds ratio (OR) 1.8, 95% confidence interval (CI): 1.0-3.1, P=0.041] or BGU (OR 1.6, 95% CI: 1.0-2.5, P=0.040), than in the control group regardless of Helicobacter pylori infection. The IL-8-251 A/A genotype was more common in H. pylori-positive patients with GC (OR 2.0, 95% CI: 1.2-3.6, P=0.013) or BGU (OR 2.7, 95% CI: 1.5-4.8, P=0.001) than in H. pylori-positive controls. In addition, the frequencies of IL-6-572 G/G (OR 0.3, 95% CI: 0.1-0.9, P=0.027) and of G carriers (OR 0.5, 95% CI: 0.4-0.8, P=0.003) were lower in H. pylori-positive duodenal ulcer patients than in H. pylori-positive controls. IL-10-592 C/C (OR 0.4, 95% CI: 0.2-0.9, P=0.028) was an independent factor associated with a decreased risk of the intestinal type of GC by multivariate analysis. Furthermore, a synergistic effect was observed between IL-10-592 A/A and IL-8-251 A/A with respect to the development of GC or BGU.

CONCLUSIONS

These results suggest that the genetic polymorphisms of these 3 inflammation-related cytokines, IL-10, IL-8, and IL-6, are associated with the development of H. pylori-associated gastroduodenal disease.

IL1B promoter polymorphism regulates the expression of gastric acid stimulating hormone gastrin

It is important to dissect the effect of the alternative alleles of a functional SNP on the entire biochemical pathway for the complete understanding of the mechanism of the manifestation of complex diseases. IL1B-511C>T and -31C>T promoter polymorphisms have been suggested as potential susceptibility loci for Helicobacter pylori associated gastroduodenal diseases. We report that altered expression of IL1B due to a specific polymorphism in its promoter modulates the expression of gastrin, an acid regulating hormone. Treatment of gastric carcinoma cells, AGS, with IL1B resulted in a 20-fold reduction in gastrin expression. Gastrin promoter assay showed that IL1B inhibits gastrin expression at the transcriptional level and part of this inhibitory process is mediated via activation of NFkappaB and involvement of HDACs. An almost 3-fold increase in IL1B expression was observed when AGS cells were transfected with -31TIL1B expression plasmid in comparison to -31CIL1B. The -31TIL1B induced a 2-fold greater repression of the gastrin luciferase activity compared to -31CIL1B. This signaling of the -31TIL1B variant allele driven IL1B revealed an almost 1.5-fold greater expression of NFkappaB. Thus, this study showed that a single base substitution at the -31 position of the IL1B promoter brought about differential expression of IL1B which differentially altered both NFkappaB activation and gastrin expression.

Common variants in interleukin-1-Beta gene are associated with intracranial hemorrhage and susceptibility to brain arteriovenous malformation

BACKGROUND

Polymorphisms in the proinflammatory cytokine interleukin (IL)-1beta gene have been associated with systemic atherogenesis, thrombosis and rupture. The aim of this study was to investigate associations between single nucleotide polymorphisms (SNPs) in IL-1beta and intracranial hemorrhage (ICH) in the natural course of brain arteriovenous malformation (BAVM) patients.

METHOD

Two IL-1beta promoter SNPs (-511C-->T, -31T-->C) and 1 synonymous coding SNP in exon 5 at +3953C-->T (Phe) were genotyped in 410 BAVM patients. We performed a survival analysis of time to subsequent ICH, censoring cases at first treatment, death or last follow-up. A Cox regression analysis was performed to obtain hazard ratios (HRs) for genotypes adjusted for age, sex, Caucasian race/ethnicity and hemorrhagic presentation.

RESULTS

Subjects with the -31 CC genotype (HR = 2.7; 95% CI 1.1-6.6; p = 0.029) or the -511 TT genotype (HR = 2.6; 95% CI 1.1-6.5; p = 0.039) had a greater risk of subsequent ICH compared with reference genotypes, adjusting for covariates. The +3953C-->T SNP was not significantly associated with an increased ICH risk (p = 0.22). The IL-1beta promoter polymorphisms were also associated with BAVM susceptibility among a subset of 235 BAVM cases and 255 healthy controls of Caucasian race/ethnicity (p < 0.001).

CONCLUSION

IL-1beta promoter polymorphisms were associated with an increased risk of ICH in BAVM clinical course and with BAVM susceptibility. These results suggest that inflammatory pathways, including the IL-1beta cytokine, may play an important role in ICH.

TLR4 single-nucleotide polymorphisms alter mucosal cytokine and chemokine patterns in Mexican patients with Helicobacter pylori-associated gastroduodenal diseases

Helicobacter pylori is associated with peptic ulcer and gastric adenocarcinoma. Toll-like receptors (TLRs) participate in H. pylori recognition, and single-nucleotide polymorphisms (SNPs) in TLRs are associated with impaired immune response. We aimed to evaluate the association of TLR2/R753Q and TLR4/D299G/T399I SNPs with gastroduodenal diseases; and study the effect of SNPs on cytokine and chemokine expression in the gastric mucosa. Study included 450 Mexican patients with gastroduodenal diseases. SNPs in TLRs 2 and 4 genes were analyzed by allele-specific PCR. Cytokines and chemokines were assessed by qRT-PCR and immunoassay. TLR4/D299G/T399I polymorphisms were more frequent in duodenal ulcer and showed a trend in gastric cancer, when compared with non-atrophic gastritis. Patients with TLR4 polymorphisms expressed significantly lower levels of IL-1beta, IL-6, IL-8 and GRO-alpha; and higher levels of TNF-alpha, IL-10, MCP-1 and MIP-1alpha . SNPs in TLR4 gene had an association with severe H. pylori-associated disease and with modified pattern of inflammatory cytokines and chemokines in the gastric mucosa. These results suggest that TLR4 SNPs contributes importantly to the clinical outcome of H. pylori infection.

C314T polymorphism in histamine N-methyltransferase gene and susceptibility to duodenal ulcer in Chinese population

BACKGROUND

Histamine is a regulator of gastric acid secretion, which is involved in the development of duodenal ulcer (DU). Histamine is metabolized by both histamine N-methyltransferase (HNMT) and diamine oxidase, and its local action is terminated primarily by methylation which is catalyzed by HNMT.

METHODS

Polymerase chain reaction-restriction fragment length polymorphism assay was used to identify the polymorphism of the point mutation C314T of HNMT gene of 498 Chinese patients with DU and 151 healthy individuals.

RESULTS

In normal controls, the allele frequency of HNMT T314 was 3.3%, which was significantly lower than American Caucasians. The HNMT T314 allele was detected in 3.5% of the DU patients. In cases and controls, the frequency of C/C genotypes were 93.0% and 93.4%, respectively. The HNMT T/T genotype was not found in this population. No significant differences were seen in both genotype frequencies and allele frequencies between DU groups and controls. After stratified by H. pylori infection, they also could not reach significant differences in our current study.

CONCLUSION

The HNMT T314 allele frequency is lower in Chinese population than in American Caucasians. No association can be found in the involvement of HNMT C314T polymorphism in the susceptibility to duodenal ulcer.

Analysis of common transforming growth factor beta-1 gene polymorphisms in gastric and duodenal ulcer disease: pilot study

BACKGROUND AND AIM

Transforming growth factor-beta1 (TGF-beta1) has been shown to be an important cytokine that plays a role in cell proliferation, differentiation, tissue injury repair and ulcer healing. The purpose of this pilot study was to investigate if common polymorphisms Leu10Pro, Arg25Pro and C-509T within the TGF-beta1 gene are associated with susceptibility to gastric and duodenal ulcer disease in Russians.

METHOD

Blood samples from 377 unrelated patients with gastric and duodenal ulcer disease and 226 sex- and age-matched healthy controls were used to determine TGF-beta1 gene polymorphisms by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

Leu10Pro substitution in the signal peptide of TGF-beta1 has been found to be associated with susceptibility to gastric ulcer (odds ratio [OR] 1.76, 95% confidence interval [CI] 1.12-2.77). A genotype combination of 10Leu/Leu x 25Arg/Arg x -509C/C was also associated with susceptibility to gastric ulcer disease (OR 1.81, P = 0.01). In addition, the frequency of a combination of genotypes 10Pro/Pro x 25Arg/Pro x -509C/T was statistically lower in patients with duodenal ulcer than in controls (OR 0.42, P = 0.05). A significant difference (P = 0.04) in the distribution of rare haplotypes of the TGF-beta1 gene between patients with duodenal ulcer and healthy controls has been found. Polymorphism Leu10Pro was in positive linkage disequilibrium with C-509T polymorphism (coefficient D = 0.191; P < 0.0001).

CONCLUSIONS

These findings indicate that the Leu10Pro and C-509T polymorphisms may be involved in the modulation of expression of the TGF-beta1 gene, and therefore a predisposition to peptic ulcer disease could be linked to particular alleles of this gene. In particular, a possible role of TGF-beta1 in the pathogenesis of gastric ulcer disease is discussed.

GABRA6 genetic polymorphism is associated with the risk of functional heartburn in Chinese

BACKGROUND AND AIM

Polymorphisms of GABA(A)alpha6 (GABRA6)-1521 and IL-1beta-511 have been linked with susceptibility to stress and gastric acid secretion. The aim of this study was to assess psychiatric profiles and GABRA6 and IL-1beta genotypes in functional heartburn, an important esophageal reflux condition.

METHODS

Psychological symptoms were assessed with a Brief Symptom Rating Scale and personality traits with a short-form Maudsley Personality Inventory. DNA from 452 healthy controls, 80 controls with neurosis, and 122 patients with functional heartburn was genotyped with PCR-RFLP technique.

RESULTS

Symptom-scale parameters (except hostility) were significantly higher in patients with functional heartburn than in healthy controls; their neuroticism scores were also higher, but extroversion scores were lower. Distribution of GABRA6 genotypes in patients with functional heartburn showed more heterozygotes than among healthy controls and neurotic subjects, but distributions of IL-1beta genotypes were similar. Multiple logistic regression analysis showed GABRA6 heterozygosity was significantly associated with functional heartburn (odds ratio, 2.37; 95% confidence interval, 1.36-4.12; P < 0.01) even after adjustment for age, sex, Helicobacter pylori infection, General Symptom Index, and score of neuroticism.

CONCLUSIONS

Chinese patients with certain psychiatric characteristics and GABRA6 heterozygosity are probably predisposed to functional heartburn, providing insight into this condition's psychopathology and genetics.

Different effects of polymorphisms of tumor necrosis factor-alpha and interleukin-1 beta on development of peptic ulcer and gastric cancer

BACKGROUND AND AIM

In Western countries, polymorphism of pro-inflammatory cytokine genes is associated with the development of gastric cancer and duodenal ulcer. The aim of this study was to clarify the association of polymorphisms of interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha with susceptibility to peptic ulcer diseases and gastric cancer in Japan.

METHODS

The IL-1beta-511/-31 and TNF-alpha-308/-857/-863/-1031 genotypes were determined in Helicobacter pylori-positive patients with gastritis only (n = 164), gastric ulcers (n = 110), duodenal ulcers (n = 94), or gastric cancers (n = 105), and in H. pylori-negative controls (n = 172).

RESULTS

Carriage of the alleles TNF-alpha-857 T (odd ratio [OR], 1.826; 95% confidence interval [CI], 1.097-3.039), TNF-alpha-863 A (OR, 1.788; 95% CI, 1.079-2.905) and TNF-alpha-1031 C (OR, 1.912; 95% CI, 1.152-3.171) was associated with increased risk for gastric ulcer development. Carriage of the alleles TNF-alpha-857 T (OR, 1.686; 95% CI, 1.003-2.832), TNF-alpha-863 A (OR, 1.863; 95% CI, 1.118-3.107) and TNF-alpha-1031 C (OR 2.074; 95% CI, 1.244-3.457) was also associated with increased risk of gastric cancer development. There was no relationship between the development of H. pylori-related diseases and polymorphisms of IL-1beta-511/-31 and TNF-alpha-308. The simultaneous carriage of three different high-producer alleles of TNF-alpha-857/-863/-1031 significantly increased the risk of gastric ulcer (OR, 6.57; 95% CI, 2.34-18.40) and gastric cancer (OR, 5.20; 95% CI, 1.83-14.78).

CONCLUSIONS

Polymorphisms in TNF-alpha rather than IL-1beta are associated with increased risk for gastric ulcers and gastric cancer in Japan. The simultaneous carriage of more than one high-producer allele of TNF-alpha further increased the risks for gastric ulcer and cancer.

Effects of haplotypes in the interleukin 1beta promoter on lipopolysaccharide-induced interleukin 1beta expression

Previous studies have indicated that there are 3 common haplotypes composed of the -1470, -511, and -31 loci in the interleukin 1beta (IL-1beta) promoter in the Chinese population. The purpose of this study was to investigate the relationship between these haplotypes and lipopolysaccharide (LPS)-stimulated IL-1beta expression by whole blood leukocytes in vitro and to evaluate the effects of these haplotypes on IL-1beta gene transcription. Genomic DNAs were obtained from 105 healthy subjects. The genotypes at the 3 sites of the IL-1beta promoter were determined by restriction fragment length polymorphism analysis. Haplotype frequency was evaluated by using the Arlequin software. Plasma IL-1beta level was measured by enzyme-linked immunosorbent assay. The transcriptional activity of the haplotypes was determined by in vitro reporter gene. The results indicated that after the exposure to LPS, whole blood leukocytes from subjects with the homozygous haplotype -1470G, -511C, and -31T (G-C-T) produced more IL-1beta in vitro than those from subjects with haplotype -1470C, -511T, and -31C (C-T-C) and that the transcriptional activity of the haplotype G-C-T was also higher than that of the haplotype C-T-C. It is suggested that the haplotypes of the IL-1beta promoter influence the expression and transcriptional activity of the IL-1beta gene and that the upregulation of IL-1beta gene expression after LPS exposure in subjects with haplotype G-C-T may be due to an increased transcriptional activity of the haplotype.

Interaction between IL1B gene promoter polymorphisms in determining susceptibility to Helicobacter pylori associated duodenal ulcer

It has been speculated that IL-1 genes play a crucial role in the genetic predisposition to duodenal ulcer upon H. pylori infection by modulating the host immune response. In the present study, 310 individuals from Eastern India were subjected to a case-control study to determine the IL1B and IL1RN risk genotypes to H. pylori mediated duodenal ulcer. An analysis of genotype frequency revealed a significantly higher frequency of IL1B -511TT (NT_022135.14:g.2302610C>T), OR=4.22 (95% CI=1.8-9.4) and -31CC (NT_022135.14:g.2302130C>T), OR=2.16 (95% CI 1.12-4.15) genotypes in H. pylori-infected individuals with duodenal ulcer compared to infected individuals with normal mucosa. Moreover, the T/C haplotype of IL1B -511 and IL1B -31 loci was present in a significantly higher frequency in H. pylori-infected duodenal ulcer patients than in infected controls (OR=2.47, CI=1.27-4.8). Quantitative analysis of the mucosal IL1B mRNA revealed that among H. pylori-infected individuals, carriers of the -31CC genotype had significantly lower IL1B transcript levels than carriers of the CT (P<0.001) and TT (P<0.001) genotypes, independently of disease status. An IL1B promoter activity assay showed that the promoter with -31T had a 10-fold increase in activity compared to the one with -31C. The IL1B promoter bearing the different combinations of both polymorphic loci showed an interaction between the -511 and -31 loci. Our results show that H. pylori-infected individuals with the -31CC genotype secrete less IL1B and are susceptible to duodenal ulcers. They also suggest that the allelic interaction between the -511 and -31 polymorphic sites determines the overall strength of the IL1B promoter.

Gastroduodenal disease, Helicobacter pylori, and genetic polymorphisms

Over the past 20 years, there has been marked progress in our understanding of the role of genetic and environmental factors in the etiology of gastroduodenal disease. Helicobacter pylori infection now is recognized to be the most important environmental factor for both noncardia gastric cancer and peptic ulcer disease. The likelihood of the infection resulting in significant disease depends on genetic polymorphisms influencing the virulence of the organism. However, the specific pattern of disease induced by the infection is determined to a great extent by genetic polymorphisms in the host that govern the local gastric immune response elicited. Genetic factors also are important in the treatment of gastroduodenal diseases. Polymorphisms of host CYP2C19 influence the pharmacokinetics and clinical efficacy of proton pump inhibitor therapy.

Role of cytokine polymorphisms in the risk of distal gastric cancer development

We review the current information concerning the role of cytokine polymorphisms and the risk of develop distal gastric cancer in different populations. We have included populations colonized with Helicobacter pylori as well as populations without colonization. We found that the study of polymorphisms alone seems insufficient to assess gastric cancer risk and it is necessary to examine environmental factors in different ethnic groups and geographic areas along with the study of H. pylori strains to define better the risk factors associated with distal gastric cancer.

Influence of IL-1 gene cluster polymorphisms on the development of H. pylori associated gastric ulcer

BACKGROUND AND AIMS

Chronic H. pylori infection is the main cause of ulcer disease which depicts a major burden of our healthy care systems. The individual host immune response plays a pivotal role in the outcome of the infection but genetic susceptibility to develop gastric ulcer is unknown. IL-1beta and its natural receptor antagonist IL-1ra are involved in the inflammatory response to H. pylori infection. Thus, we investigated the influence of functional genetic variants in the IL-1 gene cluster on the development of gastric ulcer disease.

PATIENTS AND METHODS

390 H. pylori infected patients were genotyped for IL-1B -31 and +3954 by TaqMan technology. Alleles of IL-1RN 86VNTR were determined by gel electrophoresis after amplification. Three hundred and sixty healthy blood donors were included as healthy controls.

RESULTS

Carriage of the IL-1B -31 C allele conferred a increased but not significant risk for H. pylori infection (OR: 1.3, Wald 95% CI: 0.8<OR<2.1). Patients carrying short allele 2 of IL-1RN had a 1.6-fold significantly increased risk for the development of gastric ulcer (Pearson's=4.0, p=0.044, OR: 1.6, Wald 95% CI: 1.0<OR<2.4).

CONCLUSION

Our results underline the crucial role of the host immune response to H. pylori infection and confirm the importance of polymorphisms in the IL-1 cluster as a factor to give rise to different clinical outcomes. Further studies are needed to fully understand the pathophysiological effect of polymorphisms in the IL-1 cluster in H. pylori associated ulcer disease and susceptibility to infection itself.

Haplotype analysis of the CD11 gene cluster in patients with chronic Helicobacter pylori infection and gastric ulcer disease

Helicobacter pylori infection leads to a broad spectrum of disease manifestations such as gastritis, ulcer disease, and even gastric carcinoma. The genetically determined immune response and subsequent inflammation influence the degree of mucosal damage. Adhesion molecules of the CD11 cluster play an important role in adherence of neutrophils to endothelial cells in inflammation. We conducted a haplotype-based analysis of the CD11 cluster in a sample of 315 patients with H. pylori infection and investigated associations with gastric erosions and ulcer disease. Twelve single nucleotide polymorphisms (SNPs) covering the genes CD11a, CD11b, and CD11c were genotyped by Taqman technology. Linkage disequilibrium (LD) was assessed within the CD11 cluster and haplotype case-control analysis was conducted. Sliding window haplotype analysis identified a haplotype consisting of the markers CD11c exon 15 and intron 31 associated with gastric ulcer disease. Patients carrying the haplotype GA bear a 2.4-fold increased risk. No significant associations of single markers with disease outcome were found. High-density LD mapping and mutation detection of CD11c in larger samples will be necessary to confirm our findings and identify the causative variant. Thus, we conclude that genetic variants in the CD11 cluster may play a role in the development of gastric ulcer in chronic H. pylori infection presumably by influencing leukocyte adhesion. The biological effect of genetic variants of CD11c in gastric inflammation needs further clarification.

Matrix metalloproteinase secretion by gastric epithelial cells is regulated by E prostaglandins and MAPKs

Because matrix metalloproteinases (MMPs) play roles in inflammatory tissue injury, we asked whether MMP secretion by gastric epithelial cells may contribute to gastric injury in response to signals involved in Helicobacter pylori-induced inflammation and/or cyclooxygenase inhibition. Tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and epidermal growth factor (EGF) stimulated gastric cell MMP-1 secretion, indicating that MMP-1 secretion occurs in inflammatory as well as non-inflammatory situations. MMP-1 secretion required activation of the MAPK Erk and subsequent protein synthesis but was down-regulated by the alternate MAPK, p38. In contrast, secretion of MMP-13 was stimulated by TNF-alpha/IL-1beta but not EGF and was Erk-independent and mediated by p38. MMP-13 secretion was more rapid (peak, 6 h) than MMP-1 (peak > or =30 h) and only partly depended on protein synthesis, suggesting initial release of a pre-existing MMP-13 pool. Therefore, MMP-1 and MMP-13 secretion are differentially regulated by MAPKs. MMP-1 secretion was regulated by E prostaglandins (PGEs) in an Erk-dependent manner. PGEs enhanced Erk activation and MMP-1 secretion in response to EGF but inhibited Erk and MMP-1 when TNF-alpha and IL-1beta were the stimuli, indicating that the effects of PGEs on gastric cell responses are context-dependent. These data show that secretion of MMPs is differentially regulated by MAPKs and suggest mechanisms through which H. pylori infection and/or cyclooxygenase inhibition may induce epithelial cell signaling to contribute to gastric ulcerogenesis.

Helicobacter pylori and nonmalignant diseases

This paper reviews the new literature from the past year on the association between colonization with Helicobacter pylori and non-malignant disease of the upper gastrointestinal tract. This issue has, in the past year, remained a topic of wide research interest yielding many important new data. These data show that H. pylori eradication is the most effective therapy for peptic ulcer disease, but that a considerable proportion of ulcer patients remain to have dyspeptic symptoms. The discussion on the interaction between H. pylori and NSAID use in the etiology of ulcer disease has not yet been settled. Several studies, both from Asia and Europe, now reported that H. pylori eradication has a minimal effect on the primary prevention of ulcer disease in NSAID users, but eradication appears of relevance for the secondary prevention of ulcer disease in addition to proton pump inhibitor maintenance therapy. Various studies brought further support for the hypothesis that H. pylori eradication is of some benefit for patients with non-ulcer dyspepsia, although the effects are limited. The prevalence of H. pylori is lower among GERD patients than among controls, but H. pylori eradication has not been consistently shown to increase the risk for the newly development of GERD in an individual subject undergoing H. pylori eradication. The discussion on H. pylori and GERD should not preclude us from treating H. pylori-infected patients for accepted clinical indications. In patients using proton pump inhibitors for GERD, H. pylori eradication leads to a resolution of their corpus-predominant pangastritis, without impairing the efficacy of PPI therapy.

Helicobacter pylori infection: anything new should we know?

Over the past year, 2003-4, there have been a number of studies consolidating previous work in relation to pathogenesis of disease, diagnosis and management of Helicobacter pylori. Studies into the pathogenesis of disease have identified the main adhesin of H. pylori as an important virulence marker and as a potential target for therapy. Molecular investigations of both the strain and host variations have identified the action of several of the virulence factors, e.g. cagA, vacA, on disrupting host cell signalling and the consequences in respect of the release of chemokines from the damaged gastric epithelium and the effect on apoptosis. Over the past year, there have been further diagnostic kits developed based on modifications of current technology. Two promising areas of research for diagnosis are the use of host/strain genome polymorphisms as a means of identifying high-risk patients who may develop severe disease and the use of proteomics to identify potential antigens of diagnostic (or therapeutic) use. The three main antibiotics that are used in first-line eradication regimens are clarithromycin, metronidazole and amoxycillin. Of these, metronidazole has the highest prevalence of resistance, followed by clarithromycin; amoxycillin resistance is only rarely reported. The decreasing success of current first-line therapy is the driving force for the development of new antibiotic combinations and a search for novel sources for chemotherapeutic agents and novel therapeutic targets.