Genetic variants in matrix metalloproteinase genes are associated with development of gastric ulcer in H. Pylori infection

Matrix Metalloproteinases in Helicobacter pylori-Associated Gastritis and Gastric Cancer

Gastric cancer is one of the leading causes of the cancer-related mortality worldwide. The etiology of this disease is complex and involves genetic predisposition and environmental factors, including Helicobacter pylori. Infection of the stomach with H. pylori leads to gastritis and gastric atrophy, which can progress stepwise to gastric cancer. Matrix metalloproteinases (MMPs) actively participate in the pathology development. The further progression of gastric cancer seems to be less dependent on bacteria but of intra-tumor cell dynamics. Bioinformatics data confirmed an important role of the extracellular matrix constituents and specific MMPs in stomach carcinoma invasion and metastasis, and revised their potential as predictors of the disease outcome. In this review, we describe, in detail, the impact of MMPs in H. pylori-associated gastritis and gastric cancer.

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.

Intervention effects of lotus leaf flavonoids on gastric mucosal lesions in mice infected with Helicobacter pylori

Helicobacter pylori (H. pylori) is one of the main factors that cause gastric lesions. The lotus leaf is an edible plant used in traditional Eastern medicine. This study evaluates the intervention effects of lotus leaf flavonoids (LLF) on gastric mucosal lesions in mice infected with H. pylori and explores their mechanism of action. High-performance liquid chromatography analysis reveals that LLF contain kaempferitrin (kaempferol-3,7-dirhamnoside), hypericin, astragalin (kaempferol-3-glucoside), phlorizin, and quercetin. LLF can reduce the number of gastric mucosal lesions and tissue lesions in mice with H. pylori-induced gastric lesions. LLF can increase the levels of somatostatin and vasoactive intestinal peptide in the serum of mice with gastric lesions and decrease the levels of substance P and endothelin-1 to inhibit gastric lesions. LLF can also reduce the levels of interleukin (IL)-6, IL-12, tumor necrosis factor (TNF)-α, and interferon-gamma cytokines in the serum of mice with gastric lesions. Using a quantitative polymerase chain reaction assay it can be seen that LLF can downregulate mRNA expressions of TNF-α, IL-1β, myeloperoxidase, keratin (KRT) 16, KRT6b, and transglutaminase 3 epidermal in the gastric tissues of mice with gastric lesions. Western blot analysis indicates that LLF can downregulate the protein expressions of caspase-1, Nod-like receptor protein 3, IL-1β, TNF-α, and Toll-like receptor 4 in the gastric tissues of mice with gastric lesions. LLF have beneficial effects on gastric lesions induced by H. pylori. Meanwhile LLF is more active in competition with ranitidine. LLF represent an active substance that can inhibit H. pylori-induced gastric lesions. The flavones of LLF may enhance the inhibition of gastric mucosal lesions by promoting the interaction between the compounds.

The association of matrix metalloproteinase-9 promoter polymorphisms with gastric cancer risk: a meta-analysis

Purpose

A variety of studies have observed that the single nucleotide polymorphisms (SNPs) matrix metalloproteinase-9 (MMP-9) gene may be associated with the risk of gastric cancer(GC), and a cytosine (C) to thymine (T) mutation at the -1562 site of the MMP-9 gene promoter is reported to be closely related to the susceptibility. However, because of the conflicting results of these studies, we undertook a systematic meta-analysis to assess the association between the SNPs and the risk of gastric cancer.

Materials and Methods

A computerised literature search was conducted within the databases of PubMed, EMBASE, and ISI Web of Knowledge for studies on the genetic association of MMP-9-1562C/T and gastric cancer published from 2004 to 2015. The pooled odds ratio (OR) and 95% confidence intervals (CI) were estimated for each genotype using the dominant, recessive, co-dominant, and allelic models of the matrix metalloproteinase 9.

Results

Our analysis indicated a significant association of MMP-9-1562C/T with gastric cancer (dominant model [CT+TT/CC]: OR = 1.121, 95% CI = 0.965–1.304; recessive model [CC+CT/TT]: OR = 1.663, 95% CI = 1.148–2.408; co-dominant model [TT/CC]: OR = 1.666, 95% CI = 1.127–2.461; [CT/CC]: OR = 1.078, 95% CI = 0.923–1.259; allelic model [T/C]: OR = 1.150, 95% CI =1.014–1.304).

Conclusions

Our meta-analysis results demonstrated that MMP-9-1562C/T promoter polymorphisms increase the risk of developing gastric cancer.

cag Pathogenicity island-dependent upregulation of matrix metalloproteinase-7 in infected patients with Helicobacter pylori

Helicobacter pylori (H. pylori) infection has been involved in the pathogenesis of most important gastroduodenal diseases. Matrix metalloproteinases (MMPs) are a large family of zincendopeptidases which play important roles in degradation of extracellular matrix (ECM) and various inflammatory diseases. Therefore, we examined MMP-7 mRNA levels in the gastric mucosa of patients with H. pylori infection and evaluated the effects of virulence factors, such as vacA (vacuolating cytotoxin A) and cagA (cytotoxin-associated gene), in H. pylori-infected patients upon the MMP-7 mRNA mucosal levels. We also determined the correlation between mucosal MMP-7 mRNA levels and the types of disease. Total RNA was extracted from gastric biopsies of 50 H. pylori-infected patients and 50 uninfected individuals. Mucosal MMP-7 mRNA expression level in H. pylori-infected and non-infected gastric biopsies was determined by real-time polymerase chain reaction (PCR). The presences of cagA and vacA virulence factors was evaluated using PCR. MMP-7 expression was significantly higher in biopsies of patients infected with H .pylori compared to uninfected individuals. In addition, mucosal MMP-7 mRNA expression in H. pylori-infected patients significantly associated with the cagA status and the types of disease. Our results suggest that MMP-7 might be involved in the pathogenesis of H. pylori. Peptic ulcer was associated with cag pathogenicity island-dependent MMP-7 upregulation.

Microscopic Colitis: What Do We Know About Pathogenesis?

Microscopic colitis (MC) is a common cause of chronic diarrhea. The 2 most frequent forms of MC are collagenous colitis and lymphocytic colitis. Over the past years, the incidence and prevalence of microscopic colitis are rising and this is largely attributed to a greater awareness, and concomitantly an increasing number of diagnoses. Patients with microscopic colitis report watery, nonbloody diarrhea of chronic course, abdominal pain, weight loss, and fatigue that may impair patient's health-related quality of life. The underlying mechanisms involved in the pathogenesis of microscopic colitis remain unspecified but is probably multifactorial. Collagenous colitis and lymphocytic colitis may represent specific mucosal responses to different luminal agents in predisposed individuals, resulting in an uncontrolled immune response. Genetic predisposition, altered modulation of cytokines and miRNAs, and aberrant response to drugs seem to be involved in the development of MC. Despite the progress of knowledge, still many questions remain unsolved regarding the etiology, pathophysiology, and optimal management of MC. This review gives an update on the immunological aspects of collagenous colitis and lymphocytic colitis.

Increased expression of matrix metalloproteinase-9 associated with gastric ulcer recurrence

AIM: To compare matrix metalloproteinase (MMP)-9 and tissue inhibitor of metalloproteinase (TIMP)-1 in gastric ulcer (GU) and chronic superficial gastritis (CSG).

METHODS: This study enrolled 63 patients with GU and 25 patients with CSG. During upper gastroduodenal endoscopy, we took samples of gastric mucosa from the antrum and ulcer site from patients with GU, and samples of antral mucosa from patients with CSG. Mucosal biopsy tissues were cultured for 24 h, and the culture supernatant was measured for levels of MMP-9 and TIMP-1. After receiving eradication therapy for Helicobacter pylori (H. pylori) and 8 wk proton-pump inhibitor therapy for GU, follow-up endoscopy examination was performed after 6 mo and whenever severe symptoms occurred.

RESULTS: Levels of MMP-9 and TIMP-1 at the ulcer site or in the antrum were significantly higher in GU than CSG patients. MMP-9 levels at the ulcer site were significantly higher than in the antrum in GU patients, and had a significantly positive correlation with TIMP-1. MMP-9 levels were significantly higher in H. pylori-positive than H. pylori-negative GU and CSG patients. Levels of MMP-9 or TIMP-1 at the ulcer site were associated with the histological severity of activity and inflammation. About 57 GU patients were followed up, and seven had GU recurrence. H. pyloriinfection and MMP-9 levels were risk factors for the recurrence of GU adjusted for age and sex by multiple logistic regression analysis.

CONCLUSION: MMP-9 may perform an important function in gastric ulcer formation and recurrence.

Allelic variation of the matrix metalloproteinase-9 gene is associated with collagenous colitis

BACKGROUND

Collagenous colitis is a chronic inflammatory bowel disease of unknown origin characterized by a thickened subepithelial collagen layer. Differential expression of matrix-metalloproteinases (MMPs) have been implicated in the pathogenesis of collagenous colitis. The aim was to assess genetic polymorphisms of MMP-1, -7, and -9 in a case-control setting for susceptibility to collagenous colitis.

METHODS

Seventy-five patients with symptomatic collagenous colitis and 334 healthy blood donors were genotyped for single nucleotide polymorphisms (SNPs) in MMP-1-1607, MMP-7-153, MMP-7-181, and MMP-9 exon 6 using TaqMan technology. Susceptibility to collagenous colitis was tested by comparison of the carrier status of the rare allele.

RESULTS

The carrier frequency of the allele GG of the coding SNP MMP-9 in exon 6 was 24% in patients with collagenous colitis and 14.3% in healthy blood donors (P = 0.039). The carriage of the allele GG significantly increased the risk for collagenous colitis with an odds ratio of 1.9 (95% confidence interval: 1.0-3.5). None of the other SNPs of MMP-1, MMP-7-153, and MMP-7-181 were associated with collagenous colitis.

CONCLUSIONS

Allelic variation in the MMP-9 gene may be part of a complex genetic risk profile for collagenous colitis. Further studies are needed to confirm this observation and to explore the functional role of this gene polymorphism in collagenous colitis.

Association of matrix metalloproteinase-7 (-181A>G) polymorphism with risk of esophageal squamous cell carcinoma in Kashmir Valley

BACKGROUND/AIM

Degradation of the basement membrane and extracellular matrix by matrix metalloproteinases (MMPs) is believed to be an essential step in the complicated process of hematogenous metastasis. Matrix metalloproteinase-7 (MMP-7) is a small secreted proteolytic enzyme with a broad substrate specificity, and its expression has been shown to be associated with tumor invasion and metastasis for various cancers.

PATIENTS AND METHODS

To document the role of MMP-7 polymorphism in esophageal carcinogenesis, a case-control study was performed comprising 135 patients with esophageal cancer (EC) and 195 healthy controls. Genotyping was done by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Data were statistically analyzed using χ2 - test and logistic regression models.

RESULTS

Carriers for the MMP-7 (-181A>G) GG were associated with an increased risk for EC [odds ratio (OR = 2.17; 95% confidence interval (CI) = 1.21-3.92; P = 0.010; P-trend = 0.04]. Also, in a recessive model, our results showed that MMP-7 (-181A>G) GG allele conferred significantly higher risk for EC (OR =2.16; 95% CI = 1.31-3.54; P = 0.003). The high risk due to MMP-7 (-181GG) genotype was limited to squamous cell histology of EC (OR = 2.41; 95% CI = 1.27-4.56; P = 0.007). Although smoking (Hukka) and high consumption of salted tea are independent risk factors for EC, the interaction of MMP-7 (-181A>G) genotypes with these factors did not further modulate the risk of EC.

CONCLUSIONS

In conclusion, our results show that MMP-7 (-181A>G) GG carriers are at a higher risk of esophageal squamous cell carcinoma in Kashmir valley.

Twin study indicates loss of interaction between microbiota and mucosa of patients with ulcerative colitis

BACKGROUND & AIMS

Interactions between genetic and environmental factors are believed to be involved in onset and initiation of inflammatory bowel disease. We analyzed the interaction between gastrointestinal mucosal microbiota and host genes in twin pairs discordant for ulcerative colitis (UC) to study the functional interaction between microbiota and mucosal epithelium.

METHODS

Biopsy were collected from sigmoid colon of UC patients and their healthy twins (discordant twin pairs) and from twins without UC. Microbiota profiles were determined from analysis of 16S ribosomal DNA libraries; messenger RNA profiles were determined by microarray analysis.

RESULTS

Patients with UC had dysbiotic microbiota, characterized by less bacterial diversity and more Actinobacteria and Proteobacteria than that of their healthy siblings; healthy siblings from discordant twins had more bacteria from the Lachnospiraceae and Ruminococcaceae families than twins who were both healthy. In twins who were both healthy, 34 mucosal transcripts correlated with bacterial genera, whereas only 25 and 11 correlated with bacteria genera in healthy individuals and their twins with UC, respectively. Transcripts related to oxidative and immune responses were differentially expressed between patients with UC and their healthy twins.

CONCLUSIONS

The transcriptional profile of the mucosa appears to interact with the colonic microbiota; this interaction appears to be lost in colon of patients with UC. Bacterial functions, such as butyrate production, might affect mucosal gene expression. Patients with UC had different gene expression profiles and lower levels of biodiversity than their healthy twins, as well as unusual aerobic bacteria. Patients with UC had lower percentages of potentially protective bacterial species than their healthy twins.

Helicobacter pylori and gastric cancer: factors that modulate disease risk

Helicobacter pylori is a gastric pathogen that colonizes approximately 50% of the world's population. Infection with H. pylori causes chronic inflammation and significantly increases the risk of developing duodenal and gastric ulcer disease and gastric cancer. Infection with H. pylori is the strongest known risk factor for gastric cancer, which is the second leading cause of cancer-related deaths worldwide. Once H. pylori colonizes the gastric environment, it persists for the lifetime of the host, suggesting that the host immune response is ineffective in clearing this bacterium. In this review, we discuss the host immune response and examine other host factors that increase the pathogenic potential of this bacterium, including host polymorphisms, alterations to the apical-junctional complex, and the effects of environmental factors. In addition to host effects and responses, H. pylori strains are genetically diverse. We discuss the main virulence determinants in H. pylori strains and the correlation between these and the diverse clinical outcomes following H. pylori infection. Since H. pylori inhibits the gastric epithelium of half of the world, it is crucial that we continue to gain understanding of host and microbial factors that increase the risk of developing more severe clinical outcomes.

Matrix metalloproteinase-3 promoter polymorphisms but not dupA-H. pylori correlate to duodenal ulcers in H. pylori-infected females

Background

This study investigated if the H. pylori dupA genotype and certain host single nucleotide polymorphisms (SNPs) of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs), including MMP-3, MMP-7, MMP-9, TIMP-1 and TIMP-2, might correlate with ulcer risk of H. pylori-infected Taiwanese patients.

Results

Of the 549 H. pylori-infected patients enrolled, 470 patients (265 with gastritis, 118 with duodenal ulcer, and 87 with gastric ulcer) received SNPs analysis of MMP-3_{-1612 6A > 5A}, MMP-7_{-181 A > G}, MMP-9_{exon 6 A > G}, TIMP-1_{372 T > C} and TIMP-2_{-418 G > C} by PCR-RFLP. The 181 collected H. pylori isolates were detected for the dupA genotype by PCR. The rates of dupA-positive H. pylori infection were similar among patients with duodenal ulcer (22.8%), gastric ulcer (20.0%), and gastritis (25.5%) (p > 0.05). Males had higher rates of duodenal ulcer and gastric ulcer than females (p < 0.01). Of H. pylori-infected patients, the MMP-3 6A6A genotype were more common in patients with duodenal ulcers than in those with gastritis (87.7% vs. 74.9%, p < 0.05) in females. This genotype had a 2.4-fold (95% CI: 1.02-5.66) increased risk of duodenal ulcer, compared to those with the 5A carrier. Combining the MMP-3/TIMP-1 genotype as 6A6A/CC, the risk of duodenal ulcer increased up to 3.6 fold (p < 0.05) in H. pylori-infected females.

Conclusions

The MMP-3 promoter polymorphism, but not the dupA-status, may correlate with susceptibility to duodenal ulcer after H. pylori infection in Taiwanese females.

Transforming growth factor-B1 and matrix metalloproteinase-7 promoter variants induce risk for Helicobacter pylori-associated gastric precancerous lesions

The expression of growth factors, proteolytic enzymes, fibrogenic factors, and cytokines is altered in the Helicobacter pylori-infected gastric mucosa. Therefore, we aimed to evaluate the association of functional promoter variants of transforming growth factor (TGF)-B1 and matrix metalloproteinase (MMP)-7 genes with gastritis and gastric precancerous lesions. After upper gastrointestinal endoscopy, a total of 130 rapid urease test-positive patients with nonulcer dyspepsia were examined for H. pylori infection using modified Giemsa stain and IgG anti-CagA ELISA. All patients and 200 asymptomatic controls were genotyped for TGF-B1 (-509 C>T) and MMP-7 (-181 A>G) substitutions using PCR-RFLP. The genotype and allele frequencies of TGF-B1 and MMP-7 polymorphisms did not differ between patients and controls (p > 0.05). However, the CagA-positive patients with TGF-B1 -509 T allele had higher risk for gastric atrophy (p = 0.026, odds ratio [OR] = 2.38) and lymphoid follicle development (p = 0.028, OR = 2.29). In addition, CagA-positive patients carrying MMP-7 -181 G allele had risk for lymphoid follicle formation (p = 0.027, OR = 2.30). Thus, the present study revealed significant association of functional MMP-7 and TGF-B1 gene variants toward susceptibility to H. pylori-induced precancerous gastric lesions.

Enhanced systemic matrix metalloproteinase response in Helicobacter pylori gastritis

BACKGROUND

Helicobacter pylori causes chronic gastritis, peptic ulcer disease, and is the most important risk factor for non-cardia gastric cancer, and has been shown to upregulate matrix metalloproteinases (MMPs) in infected gastric mucosa. MMPs are proteolytic enzymes regulated by tissue inhibitors of metalloproteinases (TIMPs).

AIMS

We set up this study to find out whether H. pylori gastritis induces systemic MMP response.

METHODS

Serum samples were collected from patients undergoing gastroscopy; 26 patients had H. pylori gastritis and 18 were H. pylori-negative controls with normal gastric mucosa. Serum MMP levels were analysed by enzyme-linked immunosorbent assay.

RESULTS

Significantly elevated serum levels of collagenase-2 (MMP-8), gelatinase B (MMP-9), neutrophil elastase (NE), and myeloperoxidase (MPO), and reduced serum levels of gelatinase A (MMP-2) and TIMP-1 were demonstrated in patients with H. pylori gastritis as compared to H. pylori-negative controls. No significant differences were shown in serum matrilysin-1 (MMP-7) levels.

CONCLUSIONS

For the first time, we show enhanced MMP-8 response in H. pylori infection together with other neutrophil degranulation products (MMP-9, MPO, NE). Elevated circulating neutrophil degranulation product levels in serum of H. pylori-positive patients reflect accelerated proteolysis and oxidative stress, and may contribute to extraintestinal sequelae, such as cardiovascular diseases.

Polymorphisms of matrix metalloproteinase-7 and chymase are associated with susceptibility to and progression of gastric cancer in Japan

BACKGROUND

Matrix metalloproteinases (MMPs) are a family of enzymes that degrade most macromolecules making up the extracellular matrix. MMPs are involved in not only the gastric mucosal inflammatory response but also the pathogenesis of Helicobacter pylori-associated diseases. In the renin-angiotensin system, chymase (CMA) is related to gastric carcinogenesis and angiogenesis in H. pylori-infected patients. We aimed to clarify the association of MMP-7-181 and CMA/B polymorphisms with susceptibility to gastric cancer and cancer progression in H. pylori-infected patients.

METHODS

We assessed the MMP-7-181 and CMA/B polymorphisms in H. pylori-positive patients with gastric cancer (n = 160), gastric ulcer (n = 157), duodenal ulcer (n = 121), and H. pylori-positive gastritis alone as controls (n = 156).

RESULTS

For gastric cancer risk, the age-and sex-adjusted odds ratio (OR) of the MMP-7-181 G allele carrier relative to the A/A genotype was significantly increased [OR, 2.32; 95% confidence interval (CI), 1.24-4.35], especially in patients with noncardia cancer (OR, 2.31; 95% CI, 1.22-4.36) and those with clinical stage III or IV cancer (OR, 3.66; 95% CI, 1.54-8.73). Carriage of the CMA/B A allele was significantly associated with gastric cancer development (OR, 1.73; 95% CI, 1.10-2.71). Simultaneous carriage of both the MMP-7-181 G allele and the CMA/B A allele dramatically increased the gastric cancer risk (OR, 8.18; 95% CI, 2.79-23.93).

CONCLUSIONS

In Japan, carriage of the MMP-7-181 G allele and of the CMA/B A allele were each associated with an increased risk for H. pylori-related noncardia gastric cancer development. MMP-7-181 and CMA/B genotyping tests might be useful tools for screening for individuals with higher gastric cancer risk.

p120 and Kaiso regulate Helicobacter pylori-induced expression of matrix metalloproteinase-7

Helicobacter pylori is the strongest known risk factor for gastric adenocarcinoma, yet only a fraction of infected persons develop cancer. One H. pylori constituent that augments disease risk is the cytotoxin-associated gene (cag) pathogenicity island, which encodes a secretion system that translocates bacterial effector molecules into host cells. Matrix metalloproteinase (MMP)-7, a member of a family of enzymes with tumor-initiating properties, is overexpressed in premalignant and malignant gastric lesions, and H. pylori cag(+) strains selectively increase MMP-7 protein levels in gastric epithelial cells in vitro and in vivo. We now report that H. pylori-mediated mmp-7 induction is transcriptionally regulated via aberrant activation of p120-catenin (p120), a component of adherens junctions. H. pylori increases mmp-7 mRNA levels in a cag- and p120-dependent manner and induces translocation of p120 to the nucleus in vitro and in a novel ex vivo gastric gland culture system. Nuclear translocation of p120 in response to H. pylori relieves Kaiso-mediated transcriptional repression of mmp-7, which is implicated in tumorigenesis. These results indicate that selective and coordinated induction of mmp-7 expression by H. pylori cag(+) isolates may explain in part the augmentation in gastric cancer risk associated with these strains.

MMP-7 (-181A>G) promoter polymorphisms and risk for cervical cancer

OBJECTIVES

Matrix metalloproteinase (MMP-7) is a secreted matrilysin, which contributes to tumor progression through breakdown of basement membranes and angiogenesis. Therefore, we aimed to investigate the association of MMP-7 -181A>G gene polymorphism with risk of cervical cancer.

METHODS

In the present case control study, we enrolled a total of 150 cervical cancer patients confirmed by histopathology and 162 unrelated healthy individuals. Polymorphism for MMP-7 gene (-181A>G) was genotyped by polymerase chain reaction and restriction enzyme length polymorphism.

RESULTS

Frequency of MMP-7 -181GG genotype and -181G allele differed significantly between patients with cervical cancer (29.3%) and healthy individuals (19.4%) (P=0.041; OR(GG)=1.94 and P=0.048; OR(G)=1.94). Individuals with MMP-7 -181GG genotype were at higher risk of stage II of cervical cancer with borderline significance (P=0.05, OR=2.78; 95%CI: 0.89-8.69). However, interaction of MMP-7 -181AG and GG genotypes with tobacco usage did not modulate the cervical cancer risk significantly (OR 2.21, 95%CI=0.59-8.1 and OR 3.17, 95%CI=0.64-15.7).

CONCLUSION

Individuals with MMP-7 -181GG genotype were at significantly higher risk of cervical cancer.

The role of matrix metalloproteinases in stromal/epithelial interactions in the gut

The gastrointestinal mucosa is an extremely soft, highly vascularised tissue, with a single layer of epithelium separating the gut lumen from the host. Epithelial cells adhere to a thin basement membrane that is produced by both epithelial cells and the underlying stromal cells. Signals passing between epithelial cells and stromal cells are needed for normal gut structure. In gut diseases, however, epithelial cells and stromal cells produce large amounts of matrix degrading enzymes (matrix metalloproteinases), the function of which is only beginning to be elucidated. Here, we review the role of matrix metalloproteonases (MMPs) in the gut in health, in gut inflammation, and in cancer.

Altered gastric corpus expression of tissue inhibitors of metalloproteinases in human and murine Helicobacter infection

BACKGROUND

Matrix metalloproteinases (MMPs) have roles in inflammation and other processes relevant to the architectural disturbances seen in the gastric mucosa in response to Helicobacter pylori infection. Upregulation of MMPs has been reported in H pylori infection, but there are no detailed reports regarding altered production of their inhibitors, the tissue inhibitors of metalloproteinases (TIMPs).

AIMS

To investigate changes in the abundance of TIMPs in human gastric corpus mucosa and murine stomach in Helicobacter infection, and to study cellular sources in man.

METHODS

Gastric corpus biopsy samples were assessed for abundance of mRNA or protein for TIMP-1 to -4 by real-time quantitative PCR or western blotting, respectively. Antral and corpus biopsies were processed for histology, H pylori status and inflammatory scoring. Cellular sources of TIMP-1, -3 and -4 were examined by indirect immunohistochemistry. Circulating gastrin was measured by radioimmunoassay. Also, abundance of TIMP-1, -3 and -4 mRNA in the stomach of Helicobacter felis infected mice post-infection was compared with that of uninfected control animals.

RESULTS

Compared with uninfected patients, mRNA and protein for TIMP-1, -3 and -4 were significantly more abundant in the gastric corpus of H pylori infected subjects. Gastric TIMP expression did not differ significantly between hyper- and normogastrinaemic subjects within the H pylori negative and positive groups. There was no difference in mRNA abundance for MMP-3 or -8. Immunohistochemistry showed TIMP proteins localised to gastric epithelial, stromal cells and inflammatory cells. Murine H felis infection was associated with upregulation of TIMP-1 and -3 mRNA.

CONCLUSIONS

Helicobacter infection is associated with upregulation of specific TIMPs (TIMP-1 and -3) in glandular epithelium and stroma. It is suggested that increased expression of specific protease inhibitors in the corpus mucosa may exert important effects on extracellular matrix remodelling and influence the outcome of H pylori infection.

Gastric gelatinase B/matrix metalloproteinase-9 is rapidly increased in Helicobacter felis-induced gastritis

It has previously been shown that matrix metalloproteinase-9 (MMP-9) levels, originating from macrophages, are considerably increased in human Helicobacter pylori-associated gastritis. Here, the early kinetics of the MMP-9 response resulting from Helicobacter infection in C57BL/6 and MMP-9 knock-out mice using the murine Helicobacter felis model were examined. H. felis infection induced severe gastritis in the murine stomach at just 2 weeks after infection. Before gastritis, an increase was observed in MMP-9-positive cells detected by immunohistochemistry in the basal lamina propria. This finding was corroborated by gelatin zymography of stomach samples. As the gastritis increased so did the concentration of MMP-9 and the incidence of gastric MMP-9-positive cells, their location corresponding to that of macrophages. In contrast, systemic levels of MMP-9 remained unchanged. When MMP-9-deficient mice were infected with H. felis, no significant difference in gastritis development was detected compared with disease development in wild-type animals. We conclude that MMP-9 production is an early event in the response to gastric Helicobacter infection, a feature that may favor the recruitment of immune cells early during infection. At later stages, however, the increased levels of MMP-9 may damage the integrity of the stomach mucosa.

Eradication of Helicobacter pylori infection favourably affects altered gastric mucosal MMP-9 levels

BACKGROUND

Helicobacter pylori gastritis is recognized as an important pathogenetic factor in peptic ulcer disease and gastric carcinogenesis, and is accompanied by strongly enhanced gastric mucosal matrix metalloproteinase-9 (MMP-9) levels.

AIM

This study was performed to investigate whether H. pylori-affected gastric mucosal MMP-2 and MMP-9 levels are reversible by successful treatment of the infection.

PATIENTS AND METHODS

Fifty-eight patients with H. pylori-associated gastritis were treated with a combination regimen of acid inhibitory therapy and antibiotics for 14 days. The levels and isoforms of MMP-2 and MMP-9 were measured by semiquantitative gelatin-zymography, bioactivity assay and enzyme-linked immunosorbent assay in gastric mucosal biopsy homogenates.

RESULTS

Latent, active, and total MMP-9 levels decreased consistently and significantly by successful H. pylori eradication, in antrum as well as corpus mucosa, compared with those prior to treatment, irrespective of the therapy regimen used. The elevated levels remained unchanged, however, when treatment failed. MMP-2 levels did not show major alterations after H. pylori therapy.

CONCLUSION

Elevated MMP-9 levels in H. pylori-infected gastric mucosa are reversible by eradication of the infection. No major changes in mucosal MMP-2 levels were observed by H. pylori eradication.

IL-21 is highly produced in Helicobacter pylori-infected gastric mucosa and promotes gelatinases synthesis

Helicobacter pylori (Hp) infection is associated with gastric inflammation and ulceration. The pathways of tissue damage in Hp-infected subjects are complex, but evidence indicates that T cell-derived cytokines enhance the synthesis of matrix metalloproteinases (MMP) that contribute to mucosal ulceration and epithelial damage. In this study, we have examined the role of the T cell cytokine IL-21 in Hp-infected gastric mucosa and evaluated whether IL-21 regulates MMP production by gastric epithelial cells. We show that IL-21 is constitutively expressed in gastric mucosa and is more abundant in biopsy specimens and purified mucosal CD3(+) T cells from Hp-infected patients compared with normal patients and disease controls. We also demonstrate that IL-21R is expressed by primary gastric epithelial cells, as well as by the gastric epithelial cell lines AGS and MKN28. Consistently, AGS cells respond to IL-21 by increasing production of MMP-2 and MMP-9, but not MMP-1, MMP-3, MMP-7, or tissue inhibitors of MMP. Analysis of signaling pathways leading to MMP production reveals that IL-21 enhances NF-kappaB but not MAPK activation, and inhibition of NF-kappaB activation reduces IL-21-induced MMP-2 and MMP-9 production. Finally, we show that treatment of Hp-infected gastric explants with anti-IL-21 reduces epithelial cell-derived MMP-2 and MMP-9 production. These data indicate that IL-21 is overexpressed in Hp-infected gastric mucosa where it could contribute to increased epithelial gelatinase production.

Helicobacter pylori and benign upper digestive disease

Acute infection with Helicobacter pylori causes hypochlorhydria and gastrointestinal upset. As the infection persists, patients develop chronic antral-predominant or pangastritis. Gastric and duodenal ulcers arise from chronic mucosal inflammation and disordered acid secretion in the stomach. With successful eradication of H. pylori, non-NSAID-related gastric and duodenal ulcers heal even without long-term acid suppression. More importantly, peptic ulcers and their complications rarely recur. Clearing H. pylori infection also reduces the risk of mucosal injury in NSAID and aspirin users; the protective effects are more pronounced in NSAID-naïve and aspirin users. H. pylori is unlikely to be the cause of gastro-oesophageal reflux disease. However, a patient's reflux symptoms may be more difficult to control after clearing the infection. Although there is little evidence to support a causal relationship between H. pylori and non-ulcer dyspepsia, treatment of the infection gives a modest improvement of symptoms.