Mucins,a family of heavily glycosylated proteins,present mainly in epithelial cells.They function as essential barriers for epithelium and play important roles in cellular physiological processes.Aberrant expression and glycosylation of mucins in gastric epithelium occur at pathological conditions,such as Helicobacter pylori infection,chronic atrophic gastritis,intestinal metastasis,dysplasia,and gastric cancer.This review addresses the major roles played by mucins and associated O-glycan structures in normal gastric epithelium.Further,we expound the alterations of expression patterns and glycan signatures of mucins at those pathological conditions.
Gastric Mucosa/pathology* ; Glycosylation ; Helicobacter Infections/pathology* ; Helicobacter pylori/metabolism* ; Humans ; Mucins/metabolism* ; Stomach Neoplasms/pathology*

OBJECTIVES: Helicobacter pylori infection induces selective reduction of the number of antral D-cells and results in abnormal regulation of serum gastrin secretion. The purpose of this study was to investigate the relationship between H. pylori infection and the numbers of G-cells and D-cells. METHODS: The numbers of antral G-cells and D-cells, the ratio of G-cells to D-cells and fasting serum gastrin concentrations were compared between 37 patients with (29 with duodenal ulcers and 8 with gastric ulcers) and 33 without H. pylori infection (22 with duodenal ulcers and 11 with gastric ulcers). Serum gastrin concentrations were measured using the radioimmunoassay technique. Antral mucosal biopsy specimens were examined using immunohistochemical staining with antibodies specific for gastrin and somatostatin and the numbers of G-cells and D-cells per gastric gland were counted. RESULTS: Fasting serum gastrin concentrations were significantly higher in patients with H. pylori infection compared to patients without infection (80.3 +/- 23.5 vs 47.6 +/- 14.1 pg/ml, p < 0.001). The number of G-cells per gastric gland was similar in infected and uninfected patients (7.1 +/- 3.1 vs 7.3 +/- 3.9, respectively, p > 0.5). The number of D-cells was significantly lower in patients with H. pylori infection than in uninfected patients in both duodenal and gastric ulcer patients (1.3 +/- 0.4 vs 2.5 +/- 1.6, respectively, p < 0.001). The ratio of G-cells to D-cells was also significantly higher in infected patients compared with uninfected patients for both gastric and duodenal ulcers (5.7 +/- 2.7 vs 3.5 +/- 1.9, respectively, p < 0.001). CONCLUSIONS: These results strongly suggest that Helicobacter pylori infection induces reduction of the number of antral D-cells. The resulting relative hypofunction of the inhibitory action of D-cells against G-cells may be responsible for increased serum gastrin secretion.
Case-Control Studies ; D Cells/pathology ; D Cells/metabolism ; G Cells/pathology ; G Cells/metabolism ; Gastrins/metabolism ; Gastrins/blood ; Gastritis/pathology ; Gastritis/metabolism* ; Helicobacter Infections/pathology ; Helicobacter Infections/metabolism* ; Helicobacter pylori* ; Human ; Somatostatin/metabolism

BACKGROUND/AIMS: Oxidative stress may contribute to gastric epithelial damage and mutagenesis caused by Helicobacter pylori (H. pylori). H. pylori induces recruitment and activation of inflammatory cells, which produces reactive oxygen species. H. pylori extract directly induces the synthesis of reactive oxygen species in gastric epithelial cells and causes DNA damage. The aim of this study was to investigate the association between the levels of glutathione (GSH) and H. pylori density, histological findings, endoscopic findings, clinical variables, and virulence factors. METHODS: Gastric biopsy specimens were obtained from 73 consecutive patients. The 5,5'-dithiobis-(2-nitrobenzoic acid) reaction was used to determine GSH levels. RESULTS: The infection rate of H. pylori was 68.5%. The GSH level was not related to age, sex, alcohol intake, and endoscopic findings. The GSH level was lower in patients infected with H. pylori. GSH levels were not correlated significantly with the grades of neutrophil, intestinal metaplasia, and atrophy. However, the GSH levels were significantly correlated with H. pylori density (r=-0.296, p=0.01) and monocyte grade (r=-0.257, p=0.02). The GSH levels were not related to CagA, VacA, and UreA. CONCLUSIONS: This study suggests that H. pylori causes oxidative stresses which deplete GSH in gastric mucosa of patients infected with H. pylori.
Adolescent ; Adult ; Aged ; Female ; Gastric Mucosa/*metabolism/pathology ; Glutathione/*metabolism ; Helicobacter Infections/*metabolism/pathology ; *Helicobacter pylori ; Humans ; Male ; Middle Aged ; Oxidative Stress ; Stomach Diseases/*metabolism/microbiology/pathology

BACKGROUND/AIMS: Oxidative stress may contribute to gastric epithelial damage and mutagenesis caused by Helicobacter pylori (H. pylori). H. pylori induces recruitment and activation of inflammatory cells, which produces reactive oxygen species. H. pylori extract directly induces the synthesis of reactive oxygen species in gastric epithelial cells and causes DNA damage. The aim of this study was to investigate the association between the levels of glutathione (GSH) and H. pylori density, histological findings, endoscopic findings, clinical variables, and virulence factors. METHODS: Gastric biopsy specimens were obtained from 73 consecutive patients. The 5,5'-dithiobis-(2-nitrobenzoic acid) reaction was used to determine GSH levels. RESULTS: The infection rate of H. pylori was 68.5%. The GSH level was not related to age, sex, alcohol intake, and endoscopic findings. The GSH level was lower in patients infected with H. pylori. GSH levels were not correlated significantly with the grades of neutrophil, intestinal metaplasia, and atrophy. However, the GSH levels were significantly correlated with H. pylori density (r=-0.296, p=0.01) and monocyte grade (r=-0.257, p=0.02). The GSH levels were not related to CagA, VacA, and UreA. CONCLUSIONS: This study suggests that H. pylori causes oxidative stresses which deplete GSH in gastric mucosa of patients infected with H. pylori.
Adolescent ; Adult ; Aged ; Female ; Gastric Mucosa/*metabolism/pathology ; Glutathione/*metabolism ; Helicobacter Infections/*metabolism/pathology ; *Helicobacter pylori ; Humans ; Male ; Middle Aged ; Oxidative Stress ; Stomach Diseases/*metabolism/microbiology/pathology

No abstract availble.
Gastric Mucosa/*metabolism/microbiology/pathology ; Gastritis/*metabolism/microbiology/pathology ; Helicobacter Infections/*metabolism/microbiology ; *Helicobacter pylori ; Humans ; PPAR gamma/*metabolism ; Predictive Value of Tests

Helicobacter pylori (H. pylori) has been a major concern as a gastric pathogen with unique features since discovered in the end of the 20th century. Recent data on comparative genome study have revealed that H. pylori has successfully survived with its host though over 58,000 years of evolution and migration from continent to continent. To maintain the symbiotic relationship with human, H. pylori has come up with ways to induce host tolerance as well as exert harmful injuries. Studies about H. pylori have accumulated the knowledge about how the cellular and molecular interactions are controlled and regulated to decide whether the symbiotic relationship is directed to diseases or peaceful mutualism. We reviewed recent literatures and research outcomes about the H. pylori and host interaction in molecular and cellular basis.
Adaptive Immunity ; Epithelial Cells/metabolism/microbiology/pathology ; Helicobacter Infections/immunology/metabolism/*pathology ; Helicobacter pylori/*immunology ; *Host-Pathogen Interactions ; Humans ; Symbiosis ; T-Lymphocytes/immunology/metabolism

BACKGROUND/AIMS: The unavailability of human gastric cell lines representative of the normal gastric epithelial function such as polarized monolayer restricts the application of cell culture system in approaching the field of Helicobacter pylori (H. pylori) infected gastric mucosa models. The present investigation aimed at assessing the usefulness of NCI-N87 cell line as an adequate cellular model to study the pathophysiology of human H. pylori infection. METHODS: For the identification of epithelial phenotypes at low magnification, cells were observed on a phase-contrast microscope and confocal microscope. Transepithelial resistance (TER) was measured on NCI-N87 cells seeded on Transwell(R) to identify monolayer polarity two or three times a week after confluency. The IL-8 level was determined by ELISA at 24 hours after the administration of HP60190 and IL-1alpha on NCI-N87 cells. IL-8 level was compared in both upper and lower well with the control. RESULTS: A monolayer phenotype was observed in NCI-N87 cell lines by using confocal microscope. TER was measured as 400-500 (omega x cm2) at two or three weeks after cell culture. In NCI-N87 cell lines, IL-8 level was significantly increased after 24 hour compared to control, and was prominent in the lower well. CONCLUSIONS: These results suggest that NCI-N87 cell line may be useful in H. pylori infected gastric mucosa model.
Cell Line ; Enzyme-Linked Immunosorbent Assay ; Gastric Mucosa/*microbiology/pathology ; Helicobacter Infections/metabolism/*microbiology/pathology ; *Helicobacter pylori ; Humans ; Interleukin-8/metabolism ; Microscopy, Confocal ; Microscopy, Phase-Contrast ; Phenotype

OBJECTIVETo investigate the protein expression of cyclooxygenase 2 (COX-2) and nuclear factor kappa B (NF-kappaB) in gastric mucosa-associated lymphoid tissue (MALT) lymphoma and its clinical significance.

METHODSProtein expression of COX-2 and NF-kappaB in gastric MALT lymphoma were examined by immunohistochemistry of Envision two-step method. The correlations of COX-2 and NF-kappaB expression with Helicobacter pylori (Hp) infection, clinical stage, depth of tumor invasion, tumor size, recurrent rate and treatment were analyzed by univariate, multivariate and Pearson analysis.

RESULTSThe positive expression of COX-2 and NF-kappaB in gastric MALT lymphoma were 48.9%(23/47) and 36.2% (17/47) respectively, and a positive correlation was found between these two factors(r=0.326,P<0.05). Moreover, COX-2 expression was positively correlated with Hp infection,clinical stage, depth of invasion and tumor size (P<0.05). Univariate analysis showed that the overall survival of gastric MALT lymphoma patients with positive COX-2 protein (59.9 months) was shorter than that of patients with negative COX-2 protein (77.8 months), but the difference was not significant (P>0.05). The survival was significantly shorter in gastric MALT lymphoma patients with positive NF-kappaB protein (26 months) than that of patients with negative NF-kappaB protein (123.2 months)(P<0.05). Multivariate Cox regression analysis revealed that clinicopathological stage was independent prognostic factor, and associated with short survival.

CONCLUSIONUp-regulated expression of COX-2 and activation of NF-kappaB are associated with Hp infection in gastric MALT lymphoma, and their protein expression is correlated with the development of tumor and prognosis.

Cyclooxygenase 2 ; metabolism ; Female ; Gastric Mucosa ; metabolism ; microbiology ; Helicobacter Infections ; metabolism ; Helicobacter pylori ; Humans ; Lymphoma, B-Cell, Marginal Zone ; metabolism ; microbiology ; pathology ; Male ; Middle Aged ; NF-kappa B ; metabolism ; Neoplasm Staging ; Prognosis ; Stomach Neoplasms ; metabolism ; microbiology ; pathology

OBJECTIVETo evaluate the H. pylori and Epstein-Barr virus infection in cardiac and distal gastric adenocarcinoma tissues in residents in Cixian county, a high risk area of esophageal cancer in Hebei province, and to explore the putative role of H. pylori and Epstein-Barr virus infection in the carcinogenesis of adenocarcinoma at different subsites of stomach.

METHODSH. pylori and Epstein-Barr virus latent membrane protein 1 (EBV-LMP1) immunopositivities were determined by Elivision(TM) plus immunohistochemical staining in 190 gastric adenocarcinoma tissues including 144 cases of cardiac adenocarcinoma and 46 cases of distal gastric adenocarcinoma. The relationship between H. pylori and Epstein-Barr virus infection and the subsite, Laurén type as well as other clinicopathological features of gastric adenocarcinoma were analyzed.

RESULTSNo significant difference was found between the H. pylori detection rates in cardiac and distal gastric adenocarcinomas(56.9% vs. 65.2%, P > 0.05). The detection rate of H. pylori in intestinal type was significantly higher than that in the diffuse type distal gastric adenocarcinomas (71.8% vs. 28.6%, P < 0.05). No positive expression of EBV-LMP1 was found in the gastric adenocarcinomas in this study.

CONCLUSIONSNo significant differences in H. pylori and EBV-LMP1 infections were found between cardiac and distal gastric adenocarcinomas in Cixian county. H. pylori infection is related with the intestinal type of distal gastric adenocarcinoma.

Adenocarcinoma ; microbiology ; pathology ; virology ; Aged ; Cardia ; China ; Epstein-Barr Virus Infections ; pathology ; Female ; Helicobacter Infections ; pathology ; Helicobacter pylori ; isolation & purification ; Humans ; Male ; Middle Aged ; Stomach Neoplasms ; microbiology ; pathology ; virology ; Viral Matrix Proteins ; metabolism

OBJECTIVETo investigate the correlation between infection with L-form of Helicobacter pylori (Hp-L) and the expressions of macrophage migration inhibition factor (MIF), matrix metalloproteinase 9 (MMP9), and vascular endothelial growth factor (VEGF) in gastric cancer.

METHODSHp-L was examined in 80 gastric carcinoma and 50 adjacent normal tissues by Gram staining and immunohistochemical staining, and the expressions of MIF, MMP9 and VEGF were detected by immunohistochemical staining; the expression of MIF mRNA was detected by RT-PCR and the expression of MIF, MMP9 and VEGF proteins were detected by Western blotting in 30 fresh gastric cancer tissues and the corresponding adjacent tissues.

RESULTSOf the 80 gastric carcinoma tissues, 57 (71.25%) showed Hp-L positivity detected by both Gram staining and immunohistochemical staining, as compared with a rate of only 14% in the adjacent normal tissues (P<0.05). The gastric carcinoma tissues showed higher expression levels of MIF, MMP9 and VEGF proteins than the corresponding adjacent normal mucosa; the positivity MIF, MMP-9 and VEGF proteins were significantly higher in Hp-L-positive gastric carcinoma than in Hp-L-negative cases (P<0.05). Positive correlations were found between Hp-L positivity and the expressions of MIF, MMP-9 and VEGF (r=0.598, 0.292, 0.341, respectively, P<0.05). The 30 fresh gastric cancer tissues showed also significantly higher MIF mRNA expression and MIF, MMP-9 and VEGF protein expressions than the adjacent tissues (t=3.729, P<0.01). The expressions of MIF and MMP-9 were also related to the clinicopathological factors including lymph node metastasis and depth of invasion (P<0.05).

CONCLUSIONInfection with L-form of Hp-L can be an important factor that contributes to the invasion and metastasis of gastric carcinoma, the mechanism of which involves up-regulated expressions of MIF, MMP-9 and VEGF.

Adult ; Aged ; Aged, 80 and over ; Female ; Helicobacter Infections ; metabolism ; pathology ; Helicobacter pylori ; Humans ; L Forms ; Lymphatic Metastasis ; Macrophage Migration-Inhibitory Factors ; metabolism ; Male ; Matrix Metalloproteinase 9 ; metabolism ; Middle Aged ; Stomach Neoplasms ; metabolism ; microbiology ; pathology ; Vascular Endothelial Growth Factor A ; metabolism