Taku Tsukui

Case-control study on the association of upper gastrointestinal bleeding and nonsteroidal anti-inflammatory drugs in Japan.

ObjectiveStudies in Western populations have shown the association of nonsteroidal anti-inflammatory drugs (NSAIDs) and upper gastrointestinal bleeding (UGIB). The role of Helicobacter pylori infection in NSAIDs-related UGIB remains to be studied. We conducted a case-control study in Japan to investigate these related topics.MethodsCases of UGIB due to duodenal or gastric ulcer, or gastritis were identified in 14 study hospitals in various areas of Japan. For each case, two controls were identified from population registries in the same district. Information on drugs and other risk factors was obtained from 175 cases and 347 controls by telephone interviews. Anti-H. pylori antibody in the urine was measured in a single laboratory for all the cases and 225 controls.ResultsThe odds ratio (OR) of UGIB was 5.5 for aspirin and 6.1 for other NSAIDs (NANSAIDs) (p<0.01). The OR for regular use was higher than for occasional use both for aspirin (7.7 vs 2.0) and NANSAIDs (7.3 vs 4.1). Loxoprofen (5.9), frequently used in Japan as a safe ‘prodrug’, was significantly associated with UGIB. The odds ratio for H. pylori infection was 4.9 and the relative excess risk due to the interaction between H. pylori and the use of NSAID was 1.2 (95% CI: −5.8–8.1).ConclusionNSAIDs including loxoprofen increase the risk of UGIB in Japan as in Western countries, with a similar magnitude of association. There was no evidence of biological interaction between NSAIDs and H. pylori infection.

Localisation of cyclooxygenase 1 and cyclooxygenase 2 in Helicobacter pylori related gastritis and gastric ulcer tissues in humans

BACKGROUND Prostaglandin endoperoxide synthase/cyclooxygenase (COX) is the key enzyme in gastric mucosal protection and repair but its cellular localisation in the human stomach is still unclear. AIMS To investigate immunohistochemically the cellular distribution of COX-1 and COX-2 proteins in the human stomach with or without gastritis or ulceration. PATIENTS AND METHODS Tissues were obtained by surgical resection of gastric ulcers associated with perforation (n=9) or by biopsy from Helicobacter pylori positive patients with gastric ulcers (n=45) and H pylori negative healthy subjects (n=15). COX expression was detected by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR), western blotting, and light and electron microscopic immunohistochemistry. RESULTS COX-2 mRNA and protein were detected in gastric ulcer tissues but not in intact gastric mucosa. COX-1 mRNA and protein were detected in the intact mucosa. COX-2 immunostaining was exclusively localised in macrophages and fibroblasts between necrotic and granulation tissues of the ulcer bed. The percentage of COX-2 expressing cells was significantly higher in open than in closed ulcers, and in gastritis than in gastric mucosa without H pylori infection. COX-1 immunoreactivity localised in lamina propria mesenchymal cells was similar in various stages of ulcer disease and in intact gastric mucosa. Electron microscopic immunohistochemistry revealed both COX-1 and COX-2 on the luminal surfaces of the endoplasmic reticulum and nuclear envelope of macrophages and fibroblasts. CONCLUSIONS Our results showed that COX-2 protein was induced in macrophages and fibroblasts in gastric ulcers and H pylorirelated gastritis, suggesting its involvement in the tissue repair process.

Effect of Helicobacter pylori infection on ghrelin expression in human gastric mucosa.

OBJECTIVES:One of the counter-effects of Helicobacter pylori eradication therapy is subsequent obesity. Ghrelin is a recently discovered growth hormone releasing peptide. This endogenous secretagogue increases appetite and facilitates fat storage. The majority of circulating ghrelin is produced in the gastric mucosa. Therefore, we aimed at investigating changes in ghrelin immunoreactivity in gastric mucosa tissues of patients infected with H. pylori.METHODS:Sixty-one patients with H. pylori infection (25 cases each of duodenal and gastric ulcer, and 11 cases of gastritis) and 22 healthy controls without H. pylori infection were included in the study. H. pylori-infected patients received standard proton pump-based triple therapy followed by histological examination and 13C-urea breath test to confirm H. pylori eradication. H. pylori was eradicated in 50 out of 61 patients. Biopsy specimens were obtained from antrum and corpus before and 3 months following eradication. Ghrelin expression was evaluated immunohistochemically with an anti-ghrelin antibody, and the number of ghrelin-positive cells determined per 1 mm2 of the lamina propria mucosa.RESULTS:There was no relationship between ghrelin immunoreactivity and body weight or body mass index for healthy controls. The number of ghrelin-positive cells was significantly lower for H. pylori-infected patients than for healthy controls. However, the ghrelin-positive cell number increased significantly following H. pylori eradication without significant change in severity of atrophy.CONCLUSIONS:These data indicated that H. pylori infection affected ghrelin expression. After H. pylori eradication, gastric tissue ghrelin concentration increased significantly. This could lead to the increased appetite and weight gain seen following H. pylori eradication.

Comparison of gastric emptying and plasma ghrelin levels in patients with functional dyspepsia and non-erosive reflux disease.

Background and Aims: The symptoms of postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS), the two subtypes of functional dyspepsia (FD) under the new Rome III classification, tend to overlap with those of non-erosive reflux disease (NERD). Plasma ghrelin levels have been associated with gastric motility; however, clinical studies have yet to examine this relationship among patients with PDS, EPS or NERD. Thus, this study aims to evaluate the correlation between gastric emptying and ghrelin levels as possible candidate factors for gastric motility in these diseases. Methods: One hundred and fifty-one patients presenting with typical symptoms of FD (EPS, n = 36; PDS, n = 76) or NERD (n = 39), and 20 healthy volunteers were enrolled. Gastric motility was evaluated with the Tmax value as a marker of gastric emptying using the 13C-acetate breath test. We used Rome III criteria to evaluate upper abdominal symptoms, and SRQ-D scores to determine depression status. We measured both acylated and des-acylated ghrelin levels by ELISA methods. Results: The Tmax value in PDS patients was significantly higher than in healthy volunteers. Acylated ghrelin levels were significantly lower in NERD and PDS patients than in healthy volunteers. Interestingly, there was significant correlation between the acylated ghrelin levels and Tmax value in PDS patients but not in EPS or NERD patients. Conclusion: Our results suggest that acylated ghrelin might play an important role in the pathophysiology of PDS patients through its effect on gastric emptying.

Monocyte chemoattractant protein 1 and macrophage cyclooxygenase 2 expression in colonic adenoma.

Background and aims: Cyclooxygenase 2 (COX-2) expression in subepithelial macrophages of colorectal adenoma has been suggested as the first in a series of steps leading to colorectal tumorigenesis. We tested the hypothesis that chemokines released from human colorectal adenoma epithelium might be involved in COX-2 expression in macrophages of the lamina propria. Methods: Endoscopic samples of sporadic colorectal adenomas were tested by enzyme linked immunosorbent assay for chemokines involved in macrophage chemotaxis. Localisation of adenoma macrophage chemoattractant protein 1 (MCP-1) and COX-2 were determined by immunohistochemistry. The effects of MCP-1, in the presence or absence of celecoxib, on COX-2 expression, and prostaglandin (PG) E2 and vascular endothelial growth factor (VEGF) release, were examined in human macrophages isolated from peripheral blood. Results: MCP-1 levels were markedly higher in adenoma with mild-moderate dysplasia (129.7 (19.9) pg/mg protein) and severe dysplasia (227.9 (35.4) pg/mg protein) than in normal colonic mucosa (55.8 (4.2) pg/mg protein). Other chemokine levels, macrophage inflammatory proteins (MIP)-1α and MIP-1β, and the chemokine regulated on activation of normal T cell expressed and secreted (RANTES) did not vary significantly between adenoma and normal mucosa. MCP-1 levels in both adenoma and normal colonic mucosa increased significantly three hours after tissue cultivation in vitro. MCP-1 immunoreactivity was restricted to the adenoma epithelium, with no reactivity seen in adjacent normal epithelial cells. MCP-1 stimulated COX-2 expression and PGE2 and VEGF release in human macrophages. Celecoxib, a selective COX-2 inhibitor, inhibited MCP-1-induced PGE2 and VEGF release in macrophages. Addition of exogenous PGE2 reversed this inhibitory effect on VEGF release, suggesting that MCP-1 in adenoma epithelial cells might be involved in COX-2 expression and subsequent macrophage activation. Conclusions: MCP-1 in colorectal adenoma epithelial cells might be involved in macrophage migration and COX-2 expression, leading to the subsequent development of colonic adenoma.

Microsomal prostaglandin E synthase (mPGES)-1, mPGES-2 and cytosolic PGES expression in human gastritis and gastric ulcer tissue

Recently, three different prostaglandin E2 synthases have been identified: microsomal prostaglandin E synthase (mPGES)-1, cytosolic PGES (cPGES), and mPGES-2; however, their role and connection to cyclooxygenase (COX)-2 in the gastric ulcer repair process remain unknown. Therefore, we examined mPGES-1, cPGES, and mPGES-2 expression and localization in the stomach in vitro and in vivo. Tissues were obtained from Helicobacter pylori (H. pylori)-infected patients and consisted of surgical resections of gastric ulcers, or biopsies of gastric ulcers or gastritis. mPGES-1 mRNA and protein expression levels were examined by real-time polymerase chain reaction (PCR) and Western blot analysis, respectively. mPGES-1, cPGES, and mPGES-2 localization were analyzed immunohistochemically. Induction of PGES expression in response to interleukin (IL)-1β was examined in vitro in the cultured human gastric fibroblast line Hs262.St. Real-time PCR analysis of mPGES-1 mRNA expression in biopsy samples showed significantly higher expression levels in open than in closed gastric ulcer tissue. Western blot analysis showed mPGES-1 protein expression limited to open ulcer tissue, while mPGES-2 and cPGES immunoreactivities were seen in both open and closed ulcer tissue. Immunohistochemical analysis showed strong mPGES-1 expression in fibroblasts and macrophages of the ulcer bed, paralleling COX-2 expression. cPGES and mPGES-2 expression levels were seen in both fibroblasts of the ulcer bed and in epithelial cells. Furthermore, stronger cPGES and mPGES-2 immunoreactivities were seen in scattered mast cell-like cells and neuroendocrine-like cells, respectively. Induction of mPGES-1 expression in response to IL-1β was seen in cultured gastric fibroblasts in vitro, and double immunostaining showed mPGES-1 coexpression with COX-2 in fibroblasts of the ulcer bed in vivo. In conclusion, mPGES-1, cPGES, and mPGES-2 are all expressed in gastric ulcer tissue, but only mPGES-1 parallels COX-2 expression in mesenchymal and inflammatory cells of the ulcer bed, suggesting a key role for this enzyme in the ulcer repair process.

Monocyte chemoattractant protein 1 (MCP-1) released from Helicobacter pylori stimulated gastric epithelial cells induces cyclooxygenase 2 expression and activation in T cells

Background and aims: To clarify the interaction between gastric epithelial and mucosal T cells, we examined the role of cytokines released from epithelial cells in response to Helicobacter pylori water extract protein (HPWEP) in regulating T cell cyclooxygenase 2 (COX-2) expression and activation. Methods: Media from MKN-28 cells incubated with HPWEP for 48 hours were added to Jurkat T cells and human peripheral T cells. C–C and CXC chemokine concentrations in MKN-28 cell media, and COX-2 expression, interferon γ (IFN-γ), and interleukin (IL)-4 secretions in T cells were determined by western blot analysis and ELISA methods. Distributions of COX-2 positive T cells and monocyte chemoattractant protein 1 (MCP-1) in tissue specimens with H pylori associated gastritis were determined as single or double labelling by immunohistochemistry. Results: MCP-1, IL-7, IL-8, and RANTES were detected in media from MKN-28 cells incubated with HPWEP. Media as a whole, and MCP-1 alone, stimulated COX-2 expression and peripheral T cell proliferation. Anti-MCP-1 antibody inhibited media stimulated COX-2 mRNA expression in Jurkat T cells. Media stimulated IFN-γ but not IL-4 secretion from peripheral T cells, while MCP-1 stimulated IL-4 but not IFN-γ secretion. Both stimulated cytokine release, and peripheral T cell proliferation was partially inhibited by NS-398, a specific COX-2 inhibitor. In mucosa with gastritis, COX-2 was expressed in T cells and MCP-1 was localised mainly in epithelial and mononuclear cells. MCP-1 levels and the intensity of COX-2 expression in tissue samples were closely related. Conclusions: Cytokines such as MCP-1, released from gastric epithelial cells in response to HPWEP, seem to modulate T cell immune responses, at least in part via COX-2 expression.

Impact of quadruple regimen of clarithromycin added to metronidazole-containing triple therapy against Helicobacter pylori infection following clarithromycin-containing triple-therapy failure.

Background: The establishment of an optimal second‐line regimen for Helicobacter pylori infection is required. Although quadruple therapy should overcome resistance to either clarithromycin or metronidazole, the effects of a quadruple regimen in second‐line therapy are unknown. This study aims to evaluate the efficacy of triple therapy composed of proton pump inhibitor/amoxicillin plus metronidazole with the combined additive effects of clarithromycin as a second‐line quadruple therapy against H. pylori infection.

COX-1 and COX-2 conversely promote and suppress ischemia-reperfusion gastric injury in mice

Objective. Neutrophil activation followed by free radical production is a feature that is common to the various forms of gastric injury. However, the roles of cyclooxygenase (COX)-1 and -2 in neutrophil activation have yet to be clarified in the gastric mucosa. We examined the roles of both COX-1 and COX-2 in neutrophil activation and free radical production in ischemia-reperfusion (IR) injury in the gastric mucosa of mice. Material and methods. Ischemia was induced by clamping the celiac artery for 30 min, then removing the clamp for 90 min. SC-560, a selective COX-1 inhibitor; NS-398, a selective COX-2 inhibitor; or rebamipide, a mucoprotective agent, was administered to mice 60 min before ischemia. Gastric damage was evaluated histologically and by measuring myeloperoxidase (MPO) activity. Expressions of COX protein and intercellular adhesion molecule (ICAM)-1 were evaluated by Western blot analysis and ELISA, respectively. Effects of these drugs on thiobarbituric acid reactive substances (TBARS) and gastric blood flow were also evaluated. Results. COX-2 expression was induced in gastric mucosa 60 min after reperfusion, whereas COX-1 expression remained unaltered. Localization of COX-1 and ICAM-1 in IR-injured mucosa was observed mainly in endothelial cells, while COX-2 expression was detected in mesenchymal cells such as mononuclear cells, spindle-like cells and endothelial cells. SC-560 significantly decreased gastric blood flow at the reperfusion point and reduced gastric mucosal injury in IR mice. Furthermore, SC-560 pretreatment significantly reduced MPO activity, TBARS levels and ICAM-1 expression. In contrast, NS-398 significantly increased ICAM-1 expression, MPO activity and TBARS levels, and aggravated gastric damage in IR mice. Rebamipide pretreatment reduced both COX-2 expression and IR injury. Conclusions. In IR mice, COX-2 protects the gastric mucosa by down-regulating ICAM-1 expression, whereas COX-1 is involved in up-regulating reperfusion flow, thereby aggravating the mucosa.

Monocyte chemoattractant protein 1 and CD40 ligation have a synergistic effect on vascular endothelial growth factor production through cyclooxygenase 2 upregulation in gastric cancer

BackgroundRecent studies have reported that expression of monocyte chemoattractant protein 1 (MCP-1) and its receptor (CCR2) and CD40 ligation on mesenchymal cells play important roles in tumor development. Cyclooxygenase 2 (COX-2) has also been shown to contribute to tumor angiogenesis. We examined the interaction between MCP-1 and CD40 ligation in mesenchymal cells in gastric cancer to determine the effect of these factors on vascular endothelial growth factor (VEGF) production via upregulation of COX-2 expression.MethodsCOX-2, prostaglandin E2 (PGE2), and VEGF production were evaluated in CD40 ligand (CD40L)-stimulated macrophages. CD40L and MCP-1 mRNA levels in gastric cancer tissues were evaluated by real-time polymerase chain reaction (PCR). Localizations of MCP-1, CD40L, CD34, CD40, and CCR2 in 34 gastric cancer tissue specimens were evaluated by single-or double-label immunohistochemistry.ResultsCOX-2 expression levels were significantly higher in CD40L-stimulated macrophages and correlated with increased PGE2 and VEGF production. Addition of MCP-1 to CD40L-stimulated macrophages had a synergistic effect on COX-2 expression and subsequent PGE2 and VEGF production. CD40L and MCP-1 mRNA levels were significantly higher in poorly differentiated gastric cancers than in H. pylori-infected gastritis patients. High microvessel density was significantly associated with MCP-1 and CCR2 scores and lymph node metastasis.ConclusionsMCP-1 and CD40L had a synergistic effect on COX-2 expression and subsequent VEGF production in gastric cancer.