OBJECTIVES: The significance of the coccoid forms of H. pylori is still controversial and the questions of whether these forms are viable and infective or degenerative are still open. We induced conversion from rod to coccoid forms and studied morphological changes and antigenic evolutions during this conversion and, thereby, elucidated the viability of coccoid forms. METHODS: The H. pylori strain (C001) used for Western blotting was isolated from the patient with gastric cancer. The antigenic evolution during coccoid conversion of H. pylori was studied by Western blotting, using different sera from thirty patients known to be culture positive. These sera were used to reveal the total antigens of the strain cultured for 2 days (100% rod) and 15 days (> 99% coccoid). After SDS-PAGE, with 10% separating gel of total antigens (rod and coccoid), transblotting (Trans-Blot electrophoretic cell, Bio-Rad) was taken onto a nitrocellulose membrane (Bio-Rad). Then, the blots, with human sera diluted at 1/100, were developed with color reaction by goat serum anti-human IgG with alkaline phosphatase and BCIP. RESULTS: The antigenic profiles were not changed in 46.7% (14/30 cases) and were changed in 53.3% (16/30 cases) during coccoid conversion. Antigenic fractions changed during coccoid conversion were protein band at 120 kDa and band at 35 kDa, and were not detected in coccus forms. The rest of the profiles were identical between rod and coccoid forms. The protein which disappeared include CagA (120 kDa) and porin, or adhesin (35 kDa). The morphological changes during coccoid conversion were U shaped at day 7, doughnut shaped at day 9 and full coccoid at day 15. CONCLUSIONS: The results showed that coccoid forms of H. pylori retain cellular structures similar to rod form, and some of the antigens (CagA and porin) disappeared during coccoid conversion. Therefore, coccoid form might be viable and represent one of the stages of H. pylori biological cycle.
Adaptation, Physiological ; Antigens, Bacterial/isolation & purification* ; Gastritis/microbiology ; Helicobacter Infections/microbiology ; Helicobacter pylori/ultrastructure* ; Helicobacter pylori/immunology* ; Helicobacter pylori/growth & development ; Human ; Microscopy, Electron ; Stomach Neoplasms/microbiology ; Virulence

In vitro subcultures of bacteria can lead to genetic and phenotypic changes. This study aimed at investigating the effect of repeated subcultures on the adhesion, motility, cytotoxicity, and gastric inflammation caused by Helicobacter pylori. H.pylori SS1 strain was subcultured 64 times on agar plates containing Brucella broth and 5% bovine calf serum. The adhesion, motility, cytotoxicity, and gastric inflammation produced in Mongolian gerbils were compared between the first and 64th subcultured strain. The adhesion rates, following 3 hr exposure of AGS cells to either the first strain or the 64th-transferred strain, were 21% and 12%, respectively. The motility of the 64th-transferred strain decreased significantly when compared to the 1st strain (9.1 mm vs. 15.1 mm). The cytotoxicity index tended to be higher in the first strain than in the 64th-transferred strain (73.7% vs. 69.2%). The initial infection rate on the gerbils showed no difference between the two strains. However, chronic gastric inflammation of the first strain-infected gerbils was somewhat more severe than that of the 64th-transferred strain-infected gerbils. Therefore, the use of repeatedly subcultured strains of H. pylori in virulence experiments can lead to different results from thoses of the original strain.
Animals ; Bacterial Adhesion ; Gastritis/immunology/*microbiology ; Gerbillinae ; Helicobacter Infections/immunology/*microbiology ; Helicobacter pylori/growth & development/*pathogenicity ; Male ; Virulence

BACKGROUND/AIMS: Transforming growth factor-beta (TGF-β) is a cytokine implicated in the susceptibility, development, and progression of gastrointestinal cancer and certain other neoplasms. In the later stages of cancer, TGF-β not only acts as a bystander of host-immune response, but also contributes to cell growth, invasion, and metastasis. In the current study, we generated gastric mucosal cells that stably express Smad7, and explored the Helicobacter pylori-associated biological changes between mock-transfected and Smad7-transfected RGM1 cells. METHODS: RGM1 cells stably transfected with Smad7 were infected with H. pylori, and molecular changes in apoptotic markers and inflammatory mediators were examined. Several candidate genes were explored in Smad7-overexpressing cells after H. pylori infection. RESULTS: Overexpression of Smad7 in RGM1 cells significantly increased the H. pylori-induced cytotoxicity compared to mock-transfected cells. Exaggerated increases in inflammatory mediators, cyclooxygenase 2, inducible NO synthase, and augmented apoptosis were noted in Smad7-overexpressing cells, whereas mitigated heme oxygenase 1 was noted in Smad7- overexpressing cells. These phenomena were reversed in cells transfected with Smad7 siRNA. CONCLUSIONS: These data suggest that inhibition of Smad7 is a possible target for mitigating H. pylori-associated inflammation.
Apoptosis ; Cyclooxygenase 2 ; Gastritis ; Gastrointestinal Neoplasms ; Helicobacter pylori ; Helicobacter* ; Heme Oxygenase-1 ; Inflammation ; Neoplasm Metastasis ; Nitric Oxide Synthase ; RNA, Small Interfering ; Transforming Growth Factor beta

Adolescent ; Child ; Child, Preschool ; Female ; Gastric Mucosa ; microbiology ; Gastrointestinal Diseases ; diagnosis ; microbiology ; Helicobacter Infections ; diagnosis ; microbiology ; Helicobacter pylori ; growth & development ; isolation & purification ; Humans ; Infant ; Male ; Mouth Mucosa ; microbiology

BACKGROUND/AIMS: Helicobacter pylori infection induces cyclooxygenase-2 (COX-2) and epidermal growth factor receptor (EGFR) overexpression, and these factors may engage in cross-talk. The aim of the present study was to evaluate the effect of H. pylori on EGFR signaling pathways and to determine whether celecoxib has an inhibitory effect on this pathway. METHODS: The AGS cell line was cocultured with H. pylori G27 and the isogenic cagE- mutant. The expression of COX-2, EGFR, heparin binding-epidermal growth factor (HB-EGF), and transforming growth factor-beta (TGF-beta) was measured by real time-polymerase chain reaction (RT-PCR). Next, Western blot analyses of COX-2, EGFR, total Akt, phosphorylated Akt (pAkt), and phosphorylated glycogen synthase kinase-3beta (pGSK3beta) were performed after incubating H. pylori-treated AGS cells for 24 hours with various concentrations of celecoxib (0, 10, 20, and 30 micromol/L). RESULTS: H. pylori infection upregulated the mRNA levels of COX-2, EGFR, HB-EGF, and TGF-beta, as detected by RT-PCR. However, AGS cells treated with cagE- mutants, which have a defective type IV secretion system, did not exhibit EGFR upregulation. Celecoxib had inhibitory effects on the H. pylori-induced overexpression of COX-2 (p=0.015), EGFR (p=0.025), pAkt (p=0.025), and pGSK3beta (p=0.029) by Western blot analysis. CONCLUSIONS: H. pylori with an intact type IV secretion system activated the COX-2 and EGFR-Akt pathways in the AGS cell line. As celecoxib exhibited inhibitory effects on the EGFR signaling pathway, the cross-talk of COX-2 and EGFR likely mediates H. pylori-induced gastric cancer.
Blotting, Western ; Cell Line ; Cyclooxygenase 2 ; Epidermal Growth Factor ; Glycogen Synthase ; Helicobacter ; Helicobacter pylori ; Heparin ; Intercellular Signaling Peptides and Proteins ; Pyrazoles ; Receptor, Epidermal Growth Factor ; RNA, Messenger ; Signal Transduction ; Stomach Neoplasms ; Sulfonamides ; Transforming Growth Factor beta ; Up-Regulation

BACKGROUND/AIMS: Loss of transforming growth factor beta1 (TGF-beta1) exhibits a similar pathology to that seen in a subset of individuals infected with Helicobacter pylori, including propagated gastric inflammation, oxidative stress, and autoimmune features. We thus hypothesized that gastric mucosal TGF-beta1 levels could be used to determine the outcome after H. pylori infection. METHODS: Northern blot for the TGF-beta1 transcript, staining of TGF-beta1 expression, luciferase reporter assay, and enzyme-linked immunosorbent assay for TGF-beta1 levels were performed at different times after H. pylori infection. RESULTS: The TGF-beta1 level was markedly lower in patients with H. pylori-induced gastritis than in patients with a similar degree of gastritis induced by nonsteroidal anti-inflammatory drugs. There was a significant negative correlation between the severity of inflammation and gastric mucosal TGF-beta1 levels. SNU-16 cells showing intact TGF-beta signaling exhibited a marked decrease in TGF-beta1 expression, whereas SNU-638 cells defective in TGF-beta signaling exhibited no such decrease after H. pylori infection. The decreased expressions of TGF-beta1 in SNU-16 cells recovered to normal after 24 hr of H. pylori infection, but lasted very spatial times, suggesting that attenuated expression of TGF-beta1 is a host defense mechanism to avoid attachment of H. pylori. CONCLUSIONS: H. pylori infection was associated with depressed gastric mucosal TGF-beta1 for up to 24 hr, but this apparent strategy for rescuing cells from H. pylori attachment exacerbated the gastric inflammation.
Blotting, Northern ; Enzyme-Linked Immunosorbent Assay ; Gastritis ; Helicobacter pylori ; Humans ; Inflammation ; Luciferases ; Oxidative Stress ; Transforming Growth Factor beta ; Transforming Growth Factor beta1 ; Ulcer

BACKGROUND: Though infections of Helicobacter pylori (H. pylori) are closely associated with activation of host angiogenesis, the underlying mechanisms, as well as the strategy for its prevention, have not been identified. Here, we investigated a causal role of H. pylori infection in angiogenesis of gastric mucosa and a potent inhibitory effect of a gastric proton pump inhibitor (PPI) on the gastropathy. MATERIALS AND METHODS: A comparative analysis of CD 34 expression in tissues obtained from 20 H. pylori-associated gastritis and 18 H. pylori-negative gastritis patients was performed. Expression of HIF-1alpha and VEGF were tested by using RT-PCR. To evaluate the direct effect of H. pylori infection on differentiation of endothelial HUVEC cells, we carried out an in vitro angiogenesis assay. RESULTS: H. pylori-associated gastritis tissues showed significantly higher density of CD34+ blood vessels than did H. pylori-negative gastritis tissues, and the levels were well correlated with expressions of HIF-1alpha. Conditioned media from H. pylori-infected gastric mucosal cells stimulated a tubular formation of HUVEC cells. We also found a significant inhibitory effect of PPI, an agent frequently used for H. pylori eradication, on H. pylori-induced angiogenesis. This drug effectively inhibited the phosphorylation of MAP kinase ERK1/2, which is a principal signal for H. pylori-induced angiogenesis. CONCLUSION: The fact that PPIs can down-regulate H. pylori-induced angiogenesis suggest that anti-angiogenic treatment using PPI may be a preventive approach for H. pylori-associated carcinogenesis.
Blood Vessels ; Carcinogenesis ; Culture Media, Conditioned ; Gastric Mucosa ; Gastritis ; Helicobacter pylori ; Helicobacter* ; Human Umbilical Vein Endothelial Cells ; Humans ; Phosphorylation ; Phosphotransferases ; Proton Pumps* ; Protons* ; Stomach Neoplasms ; Vascular Endothelial Growth Factor A

Adult ; Aged ; Aged, 80 and over ; Female ; Helicobacter Infections ; metabolism ; Helicobacter pylori ; classification ; pathogenicity ; Humans ; Lymphatic Metastasis ; Male ; Microvessels ; pathology ; Middle Aged ; Neoplasm Invasiveness ; Neovascularization, Pathologic ; microbiology ; pathology ; Stomach Neoplasms ; blood supply ; metabolism ; microbiology ; Vascular Endothelial Growth Factors ; 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

BACKGROUND/AIMS: Helicobacter pylori (H. pylori) infection is the cause of peptic ulcer diseases, and gastric cancer. Hydrolysis of urea generating ammonia may cause cytotoxic effects on the gastric epithelium. The ammonia may induce the synthesis of epidermal growth factor (EGF) in gastric epithelium as an adaptive cytoprotective mechanism. The first aim was to examine the concentration of ammonia and EGF in gastric juice before and after H. pylori eradication in functional dyspepsia patients. The second aim was to examine the correlation among ammonia concentration, EGF concentration, and inflammatory score of gastritis. METHODS: The concentration of ammonia and EGF were measured by ELISA. The grade and severity of gastritis were measured according to the updated Sydney system. RESULTS: The concentration of ammonia in gastric juice was much higher in the H. pylori positive subjects (10,787 +/- 6,584 micro mol/L) than in the negative subjects (2,339 +/- 1,158 micro mol/L, p<0.0001). The concentrations of EGF in gastric juice was much higher in the positive subjects (1,462 +/- 393 pg/mL) than in the negative subjects (1,088 +/- 499 pg/mL, p<0.005). The concentration of ammonia and EGF in gastric juice showed significant correlation (r=0.63, p<0.0001). The concentrations of ammonia and histologic severities showed significant correlation (r=0.41, p<0.0001). Moreover, the level of EGF in gastric juice and histologic severities showed positive correlation (r=0.20, p<0.005). CONCLUSIONS: As the concentration of ammonia in gastric juices increased, the concentration of EGF was also increased in functional dyspepsia with H. pylori infection. The concentration of EGF in gastric juice may play a role in the adaptive cytoprotection in H. pylori- induced gastritis.
Adult ; Ammonia/*analysis ; English Abstract ; Epidermal Growth Factor/*analysis ; Female ; Gastric Juice/*chemistry ; Gastritis/drug therapy/*metabolism/microbiology/pathology ; Helicobacter Infections/drug therapy/*metabolism ; *Helicobacter pylori ; Humans ; Male ; Middle Aged