Deletion of IFN-gamma reduces fumonisin-induced hepatotoxicity in mice via alterations in inflammatory cytokines and apoptotic factors.

Fumonisin B(1) (FB(1)) produces species-specific and organ-specific toxicity, including equine leukoencephalomalacia, porcine pulmonary edema, and hepatic or renal damage in other animals. FB(1) causes inhibition of ceramide synthase, leading to accumulation of free sphingoid bases. We previously reported that such cytokines as tumor necrosis factor-alpha (TNF-alpha) modify FB(1)-induced hepatic apoptosis in male mice. FB(1) also caused induction of interferon-gamma (IFN-gamma) in mouse liver, and, therefore, it was worthwhile to determine the role IFN-gamma plays in FB(1) toxicity. In the current study, male IFN-gamma-knockout (GKO) mice and their wild-type (WT) counterparts, C57BL/6J, were treated subcutaneously (s.c.) with 2.25 mg/kg/day of FB(1) for 5 days and sampled 1 day after the last injection. The levels of circulating liver enzymes were increased in WT animals but considerably less in GKO mice. Reduced hepatotoxicity in GKO mice was evident by histologic evaluation and enumeration of apoptotic cells. The induction of TNF-alpha and interleukin-12 (IL-12) p40 by FB(1) in liver was less in GKO mice compared with WT animals. The GKO mice also had a reduced accumulation of liver sphinganine than did WT mice after FB(1) treatment. Results suggested the implication of IFN-gamma in FB(1)-induced hepatotoxicity, which can be explained by a lack of TNF-alpha and IL-12 amplification in the liver of the GKO mice. In addition, the GKO mice had altered expression of various apoptotic and antiapoptotic factors in liver. These changes were accompanied by a greater number of proliferating cells in the liver of GKO mice after FB(1) treatment, which may also contribute to the reduced hepatotoxicity of FB(1) in GKO mice. Whereas the GKO mice show reduced sensitivity to FB(1) and FB(1) treatment elevates IFN-gamma expression, decreased hepatotoxicity to FB(1) could result from alterations in sphingolipid metabolism in the GKO strain.     

Induction of atrophic gastritis in ICR mice by the administration of an allogenic antigen

In an attempt to produce experimental autoimmunity in small animals the experiment was sought to induce atrophic gastritis in ICR/JCL mice. The stomach antigen of ICR mice was extracted and emulsified with an equal volume of Freund's complete adjuvant. This was subcutaneously injected in 5-week-old ICR/JCL mice at 1 week intervals for a total of 1 to 4 administrations. The stomach antibody in the serum gradually increased up to 2(6) until four weeks after the last injection of the stomach antigen. At the same time pyknosis and a decrease in number of the gastric mucosal cells, which ultimately led to the atrophying of gastric mucosa, developed. Thereafter, concomitant with the decrease in serum antibody against mucous cells, regeneration of mucous cells was especially remarkable, but atrophy of the fundic gland continued.     

Interferon-γ directly induces gastric epithelial cell death and is required for progression to metaplasia

Chronic inflammation of the gastric mucosa, often caused by autoimmune gastritis and/or infection with Helicobacter pylori, can lead to atrophy of acid-secreting parietal cells with metaplasia of remaining cells. The histological pattern marks a critical step in the progression from chronic gastritis to gastric cancer, yet underlying mechanism(s) of inflammation-induced cell death of gastric epithelial cells are poorly understood. We investigated direct effects of a type 1 cytokine associated with autoimmunity and infection, interferon-γ (IFN-γ), on gastric epithelial cells. IFN-γ was applied to three-dimensional organoid cultures of gastric epithelial cells derived from gastric corpus gland (gastroids) of control and IFN-γ receptor-deficient mice. Gastroids were also treated with supernatants from activated immune cells isolated from a mouse model of autoimmune-mediated atrophic gastritis (TxA23) with and without IFN-γ expression. Finally, histopathological analysis of atrophy and metaplasia severity was performed in TxA23 mice and compared to TxA23 × Ifng^−/− mice. Gastric epithelial cells in gastroid cultures expressed IFN-γ receptor in the basolateral membrane, and gastroids died when treated with IFN-γ in an IFN-γ receptor-dependent manner. Supernatants from immune cells containing high levels of IFN-γ were highly toxic to gastroids, and toxicity was tempered when IFN-γ was either neutralized using a monoclonal antibody or when supernatants from Ifng^−/− mouse immune cells were used. Finally, TxA23 × Ifng^−/− mice showed near-complete abrogation of pre-cancerous histopathological atrophy and metaplasia versus IFN-γ-sufficient controls. We identify IFN-γ as a critical promoter of parietal cell atrophy with metaplasia during the progression of gastritis to gastric atrophy and metaplasia. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

INDUCTION OF ATROPHIC GASTRITIS IN ICR MICE BY THE ADMINISTRATION OF AN ALLOGENIC ANTIGEN

In an attempt to produce experimental autoimmunity in small animals the experiment was sought to induce atrophic gastritis in IGR/JGL mice. The stomach antigen of ICR mice was extracted and emulsified with an equal volume of Freund's complete adjuvant. This was subcutaneously injected in 5-week-old IGR/JGL mice at 1 week intervals for a total of 1 to 4 administrations. The stomach antibody in the serum gradually increased up to 2⁶ until four weeks after the last injection of the stomach antigen. At the same time pyknosis and a decrease in number of the gastric mucosal cells, which ultimately led to the atrophying of gastric mucosa, developed. Thereafter, concomitant with the decrease in serum antibody against mucous cells, regeneration of mucous cells was especially remarkable, but atrophy of the fundic gland continued. ACTA PATH. JAP. 27: 799-808, 1977.     

First-degree relatives of early-onset gastric cancer patients show a high risk for gastric cancer: phenotype and genotype profile

First-degree relatives (FDR) of early-onset gastric cancer (EOGC) is presumed to be a population with a distinct molecular and phenotypic profile, regarding the prevalence of gastric premalignant conditions and the association with Helicobacter pylori infection and host proinflammatory gene polymorphisms. A case–control study was conducted with FDR of EOGC patients (n?=?103) and age and gender matched controls (n?=?101; ranging from spouses to neighbors and dyspeptics). Upper endoscopy was performed, Operative Link on Gastritis Assessment (OLGA) system used for staging and H. pylori (cagA and vacA) and host IL1B-511, IL1RN intron2 VNTR and IFNGR1-56 genotyping. Seventy percent of cases showed atrophy, while 19 % presented with high-stage gastritis (OLGA stage III or IV) (p?<?0.001); gastric dysplasia was present in seven cases (vs none in controls) (p?=?0.007). In cases, H. pylori was present in 82 % (vs 62 % in controls; p?=?0.004) with vacA s1 and vacA m1 + strains significantly associated with the presence of atrophy; individuals homozygous for IL1B–511*T present a significantly higher risk for dysplasia. An increased global prevalence of IFNGR1-56*T/*T polymorphism (37 % in cases vs 24 % in controls; p?=?0.03) was observed with no association with atrophic changes or dysplasia. All trends observed were kept when comparing FDR of EOGC with spouses, neighbors, or dyspeptic controls. We demonstrated that FDR of EOGC patients have an increased prevalence of high-risk OLGA stages and dysplasia that seem to be associated with high virulence H. pylori strains and pro-inflammatory host genotypes, including a possible population-specific risk marker. FDR of EOGC patients may merit specific management through endoscopic and histopathological adequate assessment of gastric mucosa and surveillance.     

Characterization of bifunctional sphingolipid Δ4-desaturases/C4-hydroxylases of trypanosomatids by liquid chromatography-electrospray tandem mass spectrometry

Six genes encoding putative sphingolipid desaturases have been identified in trypanosomatid genomes: one in Trypanosoma brucei (TbSLdes protein), one in Trypanosoma cruzi (TcSLdes) and four in Leishmania major (LmSLdes1-4), tandemly arrayed on chromosome 26. The six amino acid sequences showed the three characteristic histidine boxes, with a long spacer between the first and second box, as in fungal desaturases and bifunctional desaturases/hydroxylases, to which they are phylogenetically related. We functionally characterized the trypanosomatid enzymes by their expression in Saccharomyces cerevisiae sur2Δ mutant, which lacks C4-hydroxylase activity. The sphingoid base profile (dinitrophenyl derivatives) of each yeast mutant transformed with each one of the different parasite genes was analyzed by HPLC, using a sur2Δ mutant expressing the Schyzosaccharomyces pombe sphingolipid desaturase (SpSLdes) as positive control. TbSLdes was capable of desaturating endogenous sphingolipids at levels comparable to those found in SpSLdes. By contrast, L. major and T. cruzi enzymes showed either no or negligible activities. Using the HPLC system coupled to electrospray tandem quadrupole/time of flight mass spectrometry we were able to detect significant levels of desaturated and hydroxylated sphingoid bases in extracts of all transformed yeast mutants, except for those transformed with the empty vector. These results indicate that S. pombe, T. brucei, T. cruzi and L. major enzymes are all bifunctional. Using the same methodology, desaturated and hydroxylated sphingoid bases were detected in T. cruzi epimastigotes and L. major promastigote cells, as described previously, and in T. brucei procyclic and bloodstream forms for the first time.     

Quantitative assessment of gastric atrophy using the syntactic structure analysis

AIM: To assess the topographical relation between gastric glands, using the minimum spanning tree (MST), to derive both a model of neighbourhood and quantitative representation of the tissue's architecture, to assess the characteristic features of gastric atrophy, and to assess the grades of gastric atrophy. METHODS: Haematoxylin and eosin stained sections from corporal and antral biopsy specimens (n = 139) from normal patients and from patients with nonatrophic gastritis and atrophic gastritis of grades 1, 2, and 3 (Sydney system) were assessed by image analysis system (Prodit 5.2) and 11 syntactic structure features were derived. These included both line and connectivity features. RESULTS: Syntactic structure analysis was correlated with the semiquantitative grading system of gastric atrophy. The study showed significant reductions in the number of points and the length of MST in both body and antrum. The standard deviation of the length of MST was significantly increased in all grades of atrophy. The connectivity to two glands was the highest and most affected by the increased grade of atrophy. The reciprocal values of the Wiener, Randic, and Balaban indices showed significant changes in the volume of gland, abnormality in the shape of glands, and changes in irregularity and branching of the glands in both types of gastric mucosa. There was a complete separation in the MST, connectivity, and index values between low grade and high grade gastric atrophy. CONCLUSIONS: (1) Gastric atrophy was characterised by loss of the gland, variation in the volume, reduction in the neighbourhood, irregularity in spacing, and abnormality in the shape of the glands. (2) Syntactic structure analysis significantly differentiated minor changes in gastric gland (low grade atrophy) from high grade atrophy of clinical significance. (3) Syntactic structure analysis is a simple, fast, and highly reproducible technique and appears a promising method for quantitative assessment of atrophy.     

Rat kidney pathology induced by chronic exposure to fumonisin B1 includes rare variants of renal tubule tumor.

The carcinogenicity of fumonisin B1 (FB1), a worldwide contaminant of corn produced by Fusaria species of fungi, has been tested recently in 2-year feeding studies in Fischer F344 rats and B6C3F1 mice. Inclusion of FB1 at 50 and 80 ppm in the diet induced liver tumors in female mice, and at 50 and 150 ppm induced renal tumors in male rats (22). In the present study, the kidneys from the rat bioassay were examined to characterize the various histopathological changes associated with renal tumor induction. In all high-dose (150 ppm) and mid-dose (50 ppm) male rats, and to a lesser extent in high-dose (100 ppm) female rats, there was evidence of sustained nephrotoxicity manifested as basophilia, apoptosis, cell regeneration, and simple tubule hyperplasia, affecting proximal convoluted tubules in the deep cortex, extending into the outer region of the outer stripe of outer medulla. A further alteration consisted of sporadic areas of interstitial hyalinization in deep cortex, suggestive of expanded basement membrane, coupled with tubule atrophy. The continued presence of nephrotoxicity throughout chronic exposure to FB1 suggested that renal tumor development may have been an outcome of sustained cell loss and compensatory regeneration. In some cases, preneoplastic tubules or incipient renal tumors presented an immature or fetal form in association with interstitial hyalinization. The renal tubule tumors induced by FB1 were typified by a rare, highly malignant, anaplastic variant capable of growth by infiltration. Of the 10 renal tubule tumors diagnosed in the mid-dose males, and the 16 in the high-dose males, 8 and 10, respectively, were graded as carcinomas. Anaplastic variants represented 50% of the mid-dose carcinomas and 80% of the high-dose carcinomas. One of the anaplastic carcinomas in a mid-dose male was a true sarcomatoid phenotype not previously recorded in the rodent. Metastatic invasion of the lung occurred with 25% of the mid-dose carcinomas and 50% of the high-dose carcinomas. It was speculated that FB1 may have been influencing the growth characteristics of the induced renal tumors via its inhibitory action on the synthesis of sphingolipids, which in turn, participate in regulating cell contact, growth, and differentiation, or alternatively by affecting cell adhesion molecules.     

Effects of Fumonisin B1 on Biomechanics and Cytoskeleton of Human Umbilical Vein Endothelial Cells

Objective Fumonisin B1(FB1)is an important mycotoxin in nature worldwide.The biomechanical properties of cells are closely related to their structure and function,and the cytoskeleton is the structural and functional basis of cells motility,and therefore,from a biomechanical point of view,the purpose of this study is to investigate the effects of FB1 on the biomechanical properties,migration capacity and cytoskeletal structure of human umbilical vein endothelial cells(HUVECs),which may lay an experimental foundation for further exploration of the toxicity mechanism of fumonisin.Methods HUVECs were cultured and treated with different concentrations of FB1.Then,CCK-8 kit was used to detect the effect of FB1 on the survival rate.The osmotic fragility of the cells was measured after treatment with different osmotic pressures for30 min.The cell membrane fluidity was measured by fluorescence polarization method.The cell electrophoretic mobility was measured by cell electrophoretic apparatus.The migration capacity of the cells was observed by scratch repair assay.The changes of reactive oxygen species and cytoskeletal structure were observed by confocal laser scanning microscopy.Finally,the mRNA and protein relative expression levels of cytoskeletal binding proteins were detected by real-time PCR,Western blotting and confocal laser scanning.Results The results of CCK-8 showed that FB1 could significantly inhibit the proliferation of HUVECs in a dose-and time-dependent manner.After treatment of HUVECs with FB1,the hypotonic resistance of the cell,cell surface charge,cell membrane fluidity and migration capacity were all weakened,while reactive oxygen species were significantly increased and the cytoskeletal structure was significantly reorganized.Furthermore,RTPCR results showed that the mRNA relative expression levels of cytoskeletal binding proteins,exception of actin,were down-regulated after treated with FB1.Besides,Western blotting and statistical analysis based on fluorescence intensity of laser confocal microscopy confirmed theses changes in protein level.Conclusions FB1 can significantly affect the biomechanical properties and motility of HUVECs,which may be directly correlated to the remodel of F-actin cytoskeleton,as well as the relative expression changes of cytoskeletal binding proteins.It is significant for further exploring the toxicity mechanism of fumonisin.     

Natural zeolite clinoptilolite increases the concentrations of sphingoid bases in the yeast Yarrowia lipolytica

In the present paper, we studied the effect of natural zeolite clinoptilolite on sphingolipid metabolism in the yeast Yarrowia lipolytica. We also investigated if zeolite addition had any impact on cell shape and size, as well as on the pH alterations during the culture growth. High performance liquid chromatography analysis of sphingoid bases obtained by acid hydrolysis of complex sphingolipids from Y. lipolytica showed that their concentrations markedly rose upon the zeolite addition. The largest increase among the identified molecular species of sphingoid bases was seen in C18 phytosphingosine, whose levels rose 6.2-fold and 22.3-fold after culturing cells for 24 and 36 hours respectively in the presence of finely ground zeolite. pH measurements of the culture medium showed a similarity between pH profiles of control and zeolite-supplemented cells, suggesting that ion-exchange capacity was not probably responsible for the observed change in sphingolipid metabolism. Scanning electron microscopy revealed that zeolite affected cell size and shape. Y. lipolytica cells grown in the absence of zeolite were oval-shaped with an average cell size of 0.7-2.7 microns, whereas when cultured with zeolite, they were round-shaped and larger, having an average cell size of 1.3-2.9 microns.     

Modifications of gastric mucosa in diffuse and intestinal cancer

The study was made of 29 intestinal type gastric carcinomas, 37 diffuse type gastric carcinomas and stomach mucosa (SM). Both carcinomas slightly differed by frequency of the fundal glands atrophy. Intestinal type was characterized by a higher frequency of antral glands atrophy, intestinal metaplasia, particularly of colon type. Intestinal cell differentiation was about the same in both types. Hyperplasia of lining and endocrine cells in the fundal part of the mucosa was more frequent and neuroendocrine differentiation was more pronounced in diffuse stomach carcinoma. It is suggested that environmental impacts including helicobacter pylori result in proliferation of the epithelium, intestinal metaplasia, dysplasia and carcinoma of the intestinal type. Diffuse carcinoma is associated with proliferation of glandular epithelium (parietal, endocrine, cervical) due to genetic factors, hypergastrinemia caused by fundal gland atrophy, alkalization of the mucosa due to Helicobacter pylori infection.     

Interleukin-1 Gene Polymorphisms in Chronic Gastritis Patients Infected with Helicobacter pylori as Risk Factors of Gastric Cancer Development

Epidemiological investigations indicated association of the Helicobacter pylori infections with the occurrence of inflammatory conditions of the gastric mucosa and development of chronic gastritis and intestinal type of gastric cancer. IL1A and IL1B genes have been proposed as key factors in determining risk of gastritis and malignant transformation. The aim of this paper was to evaluate association of interleukin-1 gene polymorphisms with chronic gastritis, atrophy, intestinal metaplasia, dysplasia and intestinal type of gastric cancer in H. pylori-infected patients. Patients subjected to analysis represent group of 144 consecutive cases that suffered from dyspepsia with coexisting infection of H. pylori and chronic gastritis, chronic atrophic gastritis, intestinal metaplasia, dysplasia or gastric cancer. Molecular studies involved analysis of –889C>T polymorphism of IL1A gene and +3954C>T polymorphism of IL1B gene. Statistical analysis of association of polymorphism –889C>T of gene IL1A with changes in gastric mucosa showed lack of significance, whereas +3954C>T polymorphism of IL1B gene showed significant association. Frequency of allele T of +3954C>T polymorphism of IL1B gene was higher in group of patients with chronic gastritis, atrophy, intestinal metaplasia, dysplasia or intestinal type of gastric cancer (32.1 %) as compared with population group (23 %), χ² = 4.61 and p = 0.03. This corresponds to odds ratio: 1.58, 95 % CI: 1.04–2.4. Our results indicate that +3954C>T polymorphism of IL1B gene increase susceptibility to inflammatory response of gastric mucosa H. pylori-infected patients and plays a significant role in the development of chronic gastritis, atrophy, intestinal metaplasia, dysplasia and the initiation of carcinogenesis.     

Local and systemic immune responses in murine Helicobacter felis active chronic gastritis.

Helicobacter felis inoculated per os into germfree mice and their conventional non-germfree counterparts caused a persistent chronic gastritis of approximately 1 year in duration. Mononuclear leukocytes were the predominant inflammatory cell throughout the study, although polymorphonuclear cell infiltrates were detected as well. Immunohistochemical analyses of gastric mucosa from H. felis-infected mice revealed the presence of mucosal B220+ cells coalescing into lymphoid follicles surrounded by aggregates of Thy-1.2+ T cells; CD4+, CD5+, and alpha beta T cells predominated in organized gastric mucosal and submucosal lymphoid tissue, and CD11b+ cells occurred frequently in the mucosa. Follicular B cells comprised immunoglobulin M+ (IgM+) and IgA+ cells. Numerous IgA-producing B cells were present in the gastric glands, the lamina propria, and gastric epithelium. Infected animals developed anti-H. felis serum IgM antibody responses up to 8 weeks postinfection and significant levels of IgG anti-H. felis antibody in serum, which remained elevated throughout the 50-week course of the study.     

法莫替丁对肝硬化大鼠肝门阻断时胃粘膜的保护作用

目的：探讨法莫替丁对肝门阻断所致的肝硬化大鼠胃粘膜损伤的影响及其机制。 方法： 雄性Wistar大鼠50只，随机分为5组，每组10只;A组为健康未行肝门阻断对照组；B组为健康大鼠行肝门阻断组；C组为肝硬化未行肝门阻断组；D组为肝硬化行肝门阻断组；E组为肝硬化行肝门阻断+法莫替丁保护组。E组在手术前从尾静脉注入80 mg/kg体重的法莫替丁，而其余各组以等量生理盐水替代。观察各组的胃液pH、胃结合粘液量、胃粘膜血流及胃粘膜损伤指数。 结果： B组与A组比较，各指标差异无显著(P>0.05)；C组、D组和E组的胃液pH和胃结合粘液量明显低于A组(P<0.05)，胃粘膜血流也明显少于A组(P<0.01),损伤指数明显大于A组(P<0.01)；且D组各指标的变化均较C组明显(P<0.01)；而E组与C组相比，差异无显著(P>0.05)。 结论： 肝门阻断可引起肝硬化大鼠胃粘膜损伤的加重，法莫替丁可能通过改善胃粘膜的微循环而对肝硬化大鼠胃粘膜起保护作用。     

Propylene glycol monomethyl ether (PGME): inhalation toxicity and carcinogenicity in Fischer 344 rats and B6C3F1 mice

A series of inhalation studies with propylene glycol monomethyl ether (PGME) vapor were undertaken to characterize its subchronic toxicity in mice and chronic toxicity/oncogenicity in rats and mice. Groups of male and female Fischer 344 rats and B6C3F1 mice were exposed to 0, 300, 1,000, or 3,000 ppm vapor from 1 week to 2 years. Primary treatment-related effects included: initial sedation of animals exposed to 3,000 ppm and its subsequent resolution correlating with induction of hepatic mixed function oxidase activity and S-phase DNA synthesis; elevated mortality in high-exposure male rats and mice (chronic study); elevated deposition of alpha2u-globulin (alpha2U-G) and associated nephropathy and S-phase DNA synthesis in male rat kidneys; accelerated atrophy of the adrenal gland X-zone in female mice (subchronic study only); and increased occurrence and/or severity of eosinophilic foci of altered hepatocytes in male rats. No toxicologically relevant statistically significant increases in neoplasia occurred in either species. A numerical increase in the incidence of kidney adenomas occurred in intermediate-exposure male rats; however, the association with alpha2U-G nephropathy, a male rat specific effect, indicated a lack of relevance for human risk assessment.     

Dual Roles of Gastric Gland Mucin-specific O-glycans in Prevention of Gastric Cancer

Gastric gland mucin is secreted from gland mucous cells, including pyloric gland cells and mucous neck cells located in the lower layer of the gastric mucosa. These mucins typically contain O-glycans carrying terminal α1,4-linked N-acetylglucosamine residues (αGlcNAc) attached to the scaffold protein MUC6, and biosynthesis of the O-glycans is catalyzed by the glycosyltransferase, α1,4-N-acetylglucosaminyltransferase (α4GnT). We previously used expression cloning to isolate cDNA encoding α4GnT, and then demonstrated that αGlcNAc functions as natural antibiotic against Helicobacter pylori, a microbe causing various gastric diseases including gastric cancer. More recently, it was shown that αGlcNAc serves as a tumor suppressor for differentiated-type adenocarcinoma. This review summarizes these findings and identifies dual roles for αGlcNAc in gastric cancer.     

Helicobacter pylori regulates TLR4 and TLR9 during gastric carcinogenesis

Objective: To investigated the influence of H. pylori on TLR4 and TLR9 in gastric mucosa during gastric carcinogenesis. Methods: Gastric biopsy specimens were taken from 148 patients and divided into five groups, including normal group (n = 10), chronic superficial gastritis group (n = 35), atrophy/intestinal metaplasia group (n = 35), dysplasia group (n = 34) and gastric carcinoma group (n = 34). Immunohistochemistry was used to detect the expression of TLR4 and TLR9. Geimsa staining and rapid urea test were used for determine H. pylori infection. Results: TLR4 was detected in gastric epithelium and monocytes/macrophages in superficial gastritis, atrophy/intestinal metaplasia, dysplasia or carcinoma. TLR9 was mainly accentuated in monocytes/macrophages. TLR4 positive cells in epithelium and in monocytes/macrophages with H. pylori infection were much more than those without H. pylori infection. Similar results were also found in TLR9. When gastric epithelium was accompanied with H. pylori infection, TLR4 was significant higher in superficial gastritis and atrophy/intestinal metaplasia groups compared with dysplasia and carcinoma groups. When gastric epithelium was infected by H. pylori, TLR9 was significant higher in carcinoma group compared with superficial gastritis, atrophy/intestinal metaplasia and dysplasia. TLR4 and TLR9 show significant correlation with the severity of inflammation. Conclusions: H. pylori infection was associated with increased expression of TLR4 and TLR9 in gastric mucosa. In superficial gastritis and atrophy/intestinal metaplasia the inflammation was predominately mediated by TLR4, while in gastric cancer the inflammation was mainly mediated by TLR9.