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Motowo Mizuno

Publications and source records attributed to Motowo Mizuno.

At least 37 records · Page 2Linked to original sources
PubMed2004

Helicobacter pylori heat-shock protein 60 induces inflammatory responses through the Toll-like receptor-triggered pathway in cultured human gastric epithelial cells.

Contact between Helicobacter pylori and gastric epithelial cells results in activation of NF-kappaB followed by secretion of interleukin (IL)-8. However, host-cell receptor(s) and their ligands involved in H. pylori-related IL-8 production have yet to be fully defined. In this study, the interaction between Toll-like receptors (TLRs), which are host receptors for pathogens involved in the innate immune response, and heat-shock protein (HSP) 60, an immune-potent antigen of H. pylori, was examined during H. pylori-induced IL-8 secretion in vitro. Recombinant H. pylori HSP60 (rHpHSP60) was prepared and added to cultured KATO III human gastric epithelial cells with or without pre-incubation with mouse monoclonal anti-TLR2 or anti-TLR4 antibodies. IL-8 mRNA expression and IL-8 protein release were analysed by Northern blotting and immunoassay. Involvement of NF-kappaB activation was analysed immunocytochemically by anti-NF-kappaB p65 antibody and ammonium pyrrolidinedithiocarbamate (PDTC), an inhibitor of NF-kappaB-mediated transcriptional activation. rHpHSP60 induced IL-8 mRNA expression and IL-8 secretion in a dose-dependent manner in KATO III cells. Anti-TLR2 antibody inhibited rHpHSP60-induced IL-8 secretion by 75 %, and anti-TLR4 antibody inhibited it by 30 %. rHpHSP60 induced nuclear translocation of NF-kappaB p65, which was inhibited by pretreatment with anti-TLR2 antibody. Treatment with PDTC significantly decreased the secretion of IL-8 induced by rHpHSP60. These findings suggest that H. pylori HSP60 activates NF-kappaB and induces IL-8 production through TLR-triggered pathways in gastric epithelial cells. Thus, it is possible that H. pylori HSP60 and TLR interaction in host cells contributes to the development of gastric inflammation caused by H. pylori infection.

Animals↗
PubMed2004

Serum antibodies to Helicobacter pylori and its heat-shock protein 60 correlate with the response of gastric mucosa-associated lymphoid tissue lymphoma to eradication of H. pylori.

BACKGROUND AND AIMS: Eradication of Helicobacter pylori leads to regression of mucosa-associated lymphoid tissue (MALT) lymphomas. In this study, we measured serum antibodies to H. pylori and H. pylori-recombinant heat-shock protein 60 (rHSP60) in patients with gastric MALT lymphoma to determine whether humoral immune responses to the bacterial antigens correlate with the efficacy of eradication therapy. METHODS: Serum samples were obtained from 33 patients with H. pylori-positive gastric MALT lymphoma before undergoing therapy to eradicate the bacteria. Anti-H. pylori antibodies were measured in a commercial assay and in immunoassays to lysates and rHSP60 which were prepared from ATCC 43504 strain. RESULTS: Helicobacter pylori were eradicated in all 33 patients, and the lymphoma completely regressed histologically in 26 patients (79%). Pre-treatment titers of serum antibody to H. pylori and to rHSP60 in the patients whose tumor regressed were significantly higher than titers in patients whose tumors did not regress (p =.0011 and.035, respectively). By logistic regression analysis, age (odds ratio = 0.88, 95% confidence interval = 0.80-0.99), endoscopic appearance (0.053, 0.004-0.65), titers of anti-H. pylori antibodies (67.6, 2.5-1800), and titers of anti-rHSP60 antibody (6.4, 1.2-36) were identified as significantly associated factors with the outcome of MALT lymphoma. CONCLUSIONS: Measurement of serum antibodies to H. pylori and HSP60 might be useful for predicting the response of gastric MALT lymphoma to eradication of H. pylori.

Adult↗
PubMed2004

Complement regulatory proteins in normal human esophagus and esophageal squamous cell carcinoma.

BACKGROUND: Altered expression of three complement regulatory proteins, decay-accelerating factor (CD55), membrane cofactor protein (CD46) and homologous restriction factor 20 (CD59) has been identified in human gastrointestinal malignancies, but their expression in esophageal cancer has not been described. Therefore the purpose of the present paper was to study the distribution of these proteins in human normal and malignant esophageal mucosa. METHODS AND RESULTS: In the normal esophageal mucosa, CD55 predominantly stained on the cell membrane of squamous epithelium in the superficial and prickle cell layers, whereas CD46 most intensely stained on the cell membrane in the basal and parabasal cell layers. In contrast to this reciprocal expression of CD55 and CD46, CD59 was broadly distributed on the cell membrane in all layers. In the esophageal squamous cell carcinoma, CD55 staining was intense in the stroma but was negligible in the cancer cells. In contrast, CD46 and CD59 stained almost uniformly on the tumor cell membrane. There was a significant difference in the intensity of the staining of CD55 and CD46 among cells in various layers of normal esophageal mucosa and esophageal carcinoma cells, but not in the staining of CD59. Similar expression patterns of the three complement regulatory proteins in carcinoma cells and in normal epithelium in the basal and parabasal cell layers were observed. CONCLUSIONS: These observations on the expression of the three complement regulatory proteins would help understanding of the host immune responses involving the complement system against esophageal squamous cell carcinoma.

Antigens, CD↗
PubMed2004

[Interluekin-1 beta genetic polymorphism influences the impact of cytochrome P 2C19 genotype on the cure rate of H. pylori eradication therapy].

Genetic polymorphism of interleukin(IL)-1 beta is associated with differences in gastric acid suppression in response to H. pylori infection. Thus, the polymorphism might affect H. pylori eradication therapy since antibiotics used in treatment regimens may be acid-sensitive. We examined the impact of IL-1 beta genetic polymorphism on the cure rate of triple therapy for H. pylori in relation to cytochrome P(CYP)2C19 genotype. In the normal acid-secretion IL-1 beta genotype group, the cure rate among CYP2C19 poor metabolizers was significantly higher than among those in the CYP2C19 extensive metabolizer groups. IL-1 beta genetic polymorphism, although not an independent factor in treatment outcome, influences the impact of the CYP2C19 genotype on the cure rate of H. pylori eradication therapy.

Amoxicillin↗
PubMed2003

Release of decay-accelerating factor into stools of patients with colorectal cancer by means of cleavage at the site of glycosylphosphatidylinositol anchor.

The expression of decay-accelerating factor (DAF), a cell-membrane-complement regulator, is enhanced in colorectal cancer, and DAF is detected in the stools of patients with colorectal cancer. In this study, to elucidate mechanisms whereby DAF is released into the colonic lumen, we analyzed and compared the properties of DAF in stools and colorectal-cancer tissues. Stool specimens taken before surgery and tissue samples from surgically resected colorectal cancers were obtained from 21 patients. We analyzed DAF in stool and tissue specimens using immunoblotting, ultracentrifugation, and phase separation with Triton X-114. We analyzed the expression profile of DAF mRNA in cancer tissues using reverse transcription-polymerase chain reaction to determine whether DAF transcripts for a secretory form of DAF were present. With the use of immunoblotting, stool DAF was detected as a broad band with a molecular weight of around 70,000 kDa that migrated slightly more slowly than cancer-tissue DAF. About 90% of stool DAF was present as a soluble form that remained in the 100,000 g supernatant after ultracentrifugation. On phase separation with Triton X-114, the soluble stool DAF was partitioned mainly into the aqueous phase, indicating its hydrophilic nature and lack of the fatty-acid glycosylphosphatidylinositol anchor component. In colorectal cancer tissues, reverse transcription-polymerase chain reaction experiments revealed a nonspliced DAF messenger RNA that encodes a secretory form of DAF in just 2 of the 21 specimens examined. These data suggest that DAF is released from colorectal cancer cells by way of cleavage of membrane-bound DAF at the site of the glycosylphosphatidylinositol anchor.

Adult↗
PubMed2003

A monoclonal antibody to rat asialoglycoprotein receptor that recognizes an epitope specific to its major subunit.

We previously developed three mouse monoclonal antibodies (MoAbs) identifying the domain-specific plasma membrane proteins of rat hepatocytes. Based on the results of immunohistochemical and immunoblot analysis, one of them, clone 8D7, likely recognizes the rat asialoglycoprotein receptor (ASGPR), which consists of three polypeptide subunits: rat hepatic lectin (RHL)-1, RHL-2 and RHL-3. In this study, we examined the reactivity of MoAb 8D7 with these subunits in order to identify specifically the protein it recognizes. RHL-1 and RHL-2/3 were expressed in COS-1 mammalian kidney cells transfected with cloned cDNAs. Reactivity of MoAb 8D7 with these proteins was examined by flow cytometry, immunoblotting, and an immunofluorescence staining. By flow cytometry, MoAb 8D7 reacted with cell surface proteins on the COS-1 cells transfected with RHL-1 cDNA but not with RHL-2/3 cDNA. By immunoblotting, the antibody recognized proteins (molecular weights 45 and 96 kDa) in RHL-1-expressing cells but not in the RHL-2/3 cDNA-transfected cells. Immunoreactive staining with MoAb 8D7 was observed on the cell surface and in the cytoplasm of RHL-1-transfected COS-1 cells but not in cells expressing RHL-2/3. These findings indicate that MoAb 8D7 recognizes a subunit-specific epitope on RHL-1 of rat ASGPR.

Journal Article↗
PubMed2003

A crucial role of hepatocyte nuclear factor-4 expression in the differentiation of human ductular hepatocytes.

Ductular structures are suggested to be bipotential progenitor cells that may differentiate into hepatocytes or biliary epithelial cells (BEC). To better understand the differentiation process, we studied the expression of hepatocyte nuclear factor (HNF) in ductular structures. Matured hepatocytes in normal liver expressed HNF-1, HNF-4alpha, HNF-3beta, and C/EBPalpha in the nucleus. Normal BEC expressed HNF-1 but did not express HNF-4alpha, suggesting an important role of HNF-4alpha in maintaining the phenotype of matured hepatocytes. Ductular structures were classified into ductular cells and ductular hepatocytes. Ductular cells showed glandular or bile duct-like appearance and strongly expressed cytokeratin-7. Ductular hepatocytes showed features between BEC and hepatocytes and heterogeneously expressed cytokeratin-7. Both ductular cells and ductular hepatocytes expressed HNF-4alpha, but the nuclear localization of HNF-4alpha was more prominent in ductular hepatocytes. The expression of HNF-4alpha mRNA in ductular hepatocytes was demonstrated at the single cell level by laser capture microdissection. Regenerative hepatocytes strongly expressed all HNFs in the nucleus, whereas residual hepatocytes in massive necrosis showed low or cytoplasmic expression. These results suggest that HNF-4alpha plays an important role in the differentiation and maintenance of the matured hepatocyte phenotype and that nuclear localization of HNFs is implicated in the accomplishment of their function.

Adult↗
PubMed2003

Interleukin-1beta genetic polymorphism influences the effect of cytochrome P 2C19 genotype on the cure rate of 1-week triple therapy for Helicobacter pylori infection.

OBJECTIVES: Genetic polymorphism of interleukin (IL)-1beta is associated with differences in gastric acid suppression in response to Helicobacter pylori (H. pylori) infection. Thus, the polymorphism might affect H. pylori eradication therapy, as antibiotics used in treatment regimens may be acid sensitive. In this study, we examined the impact of IL-1beta genetic polymorphism on the cure rate of triple therapy for H. pylori in relation to cytochrome P (CYP) 2C19 genotype and antibiotic resistance. METHODS: A total 249 patients with peptic ulcer disease were randomized to receive one of the following regimens: amoxicillin and clarithromycin together with omeprazole, lansoprazole, or rabeprazole. CYP2C19 and IL-1beta-511 genetic polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: The intention-to-treat-based overall cure rate was 74.3% (95% CI=68-79%). In the normal acid secretion IL-1beta genotype group, the cure rate among CYP2C19 poor metabolizers (93.3%, 95% CI=56-99%) was significantly higher than among subjects in the CYP2C19 homozygous (60.0%, 95% CI=38-78%) and heterozygous (63.6%, 95% CI=46-78%), i.e., extensive metabolizer, groups (p<0.05). In the low acid secretion IL-1beta genotype group, there was no difference in the cure rate among the CYP2C19 genotype groups. Multiple logistic regression analysis identified susceptibility to clarithromycin (p<0.0001) and CYP2C19 genotype status (p=0.03) as significant independent factors for treatment failure. CONCLUSION: IL-1beta genetic polymorphism, although not an independent factor in treatment outcome, influences the impact of the CYP2C19 genotype on the cure rate of 1-wk triple therapy for H. pylori infection.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2003

Testing of multiple samples increases the sensitivity of stool decay-accelerating factor test for the detection of colorectal cancer.

OBJECTIVES: We previously reported that the measurements of stool decay-accelerating factor (DAF), a membrane-bound, complement regulatory protein, may be valuable for the detection of colorectal cancer. Recently we have refined the immunoassay for stool DAF. In the present study, using the refined assay, we measured stool DAF concentrations in multiple samples from patients with colorectal cancer and in healthy controls to determine whether testing of multiple samples would increase the sensitivity of the stool DAF test. METHODS: DAF was measured in three spontaneously passed stool samples from each of 100 patients with colorectal cancer and 100 control subjects without apparent colorectal disease. RESULTS: The stool DAF concentrations in the patients with colorectal cancer (median 11.1 ng/g stool; interquartile range 2.9-32.7 ng/g) were significantly higher than concentrations in the subjects without colorectal diseases (median 1.6 ng/g stool; interquartile range 0.4-3.4 ng/g) (p<0.0001). Testing of two samples from each patient significantly increased the sensitivity (72%) of the stool DAF test without significantly decreasing its specificity (92%). The stool DAF test was positive in more than one half of patients with colorectal cancer at a relatively early TNM stage or with negative fecal occult blood test. CONCLUSIONS: These findings suggest that stool DAF is a marker of colorectal cancer independent of fecal occult blood and testing of two samples increases the sensitivity of the stool DAF test. Measurement of stool DAF now seems worthy of further consideration as a noninvasive method for the detection of colorectal cancer.

Adult↗
PubMed2002

In situ expression of Granzyme B and Fas-ligand in the liver of viral hepatitis.

BACKGROUND/AIMS: The molecular mechanism involved in hepatocellular injury in viral hepatitis remains to be clarified. METHODS: We investigated the in situ expression of effector molecules of cytotoxic T lymphocytes such as Fas-ligand (Fas-L), perforin and Granzyme B (Gr-B) immunohistochemically in liver tissues from 20 patients with chronic hepatitis B (CHB) and C (CHC). The degree of cell infiltration was analysed semi-quantitatively and compared with the histological activity index (HAI). Fas-L was expressed in both CD4 and CD8 T-cells in the portal tract as well as in the parenchyma. RESULTS: Immunostaining of serial sections demonstrated that mononuclear cells at interface hepatitis and focal necrosis were mainly Fas-L positive CD8 T-cells. On the other hand, the expression of perforin or Gr-B was limited to a few mononuclear cells in the portal tract and parenchyma. Semi-quantitative analysis showed a positive correlation between HAI and the grade of infiltration of CD8 T-cells or Fas-L-positive cells, while the correlation was not apparent between HAI and the number of Gr-B positive cells. The expression of these molecules was not different between types of viruses. CONCLUSIONS: These results suggest that Fas-L-positive CD8 T-cells play a major role in the pathogenesis of liver cell injury in chronic hepatitis.

Adolescent↗
PubMed2002

Reinfection rate following effective therapy against Helicobacter pylori infection in Japan.

BACKGROUND AND AIM: In developed countries, reinfection of Helicobacter pylori (H. pylori) after eradication of the bacterium is unusual, while the reinfection rate in developing countries is variable. In this study, we determined the reinfection rate after successful H. pylori eradication in Japan, a country with a high prevalence of H. pylori infection. METHODS: After successful eradication, 377 patients were followed up by endoscopy and urea breath test annually. In reinfected patients, H. pylori strains isolated initially and after reinfection were compared by using random amplification of polymorphic DNA fingerprinting. RESULTS: H. pylori became positive in four of 337 patients (1.2) 1 year after eradication and in two of 133 patients (1.5) 2 years after eradication. One patient experienced an ulcer relapse 2 years after eradication therapy. Random amplification of polymorphic DNA fingerprinting of the isolated strains from four of the six patients showed two had identical strains (at 1 year) while the other two had different strains (one at 1 year and one at 2 years). When infection in the two patients reinfected with identical strains is considered a recrudescence, the true reinfection rate is < 0.8 per patient year. CONCLUSIONS: The reinfection rate after eradication of H. pylori is low in Japan despite the country's high prevalence of H. pylori infection.

Adult↗
PubMed2002

Distribution of collagen type IV alpha1-6 chains in human normal colorectum and colorectal cancer demonstrated by immunofluorescence staining using chain-specific epitope-defined monoclonal antibodies.

BACKGROUND AND AIM: Loss of basement membrane (BM) components, such as type IV collagen, has been demonstrated in colorectal cancer, but the fine diversity of the assembly of alpha (IV) chains, the composition of type IV collagen, and alterations in the collagen have not been fully analyzed. Here, we defined immunohistochemically the expression of alpha1-6 (IV) chains in colorectal cancer tissues and adjacent normal mucosa by the use of chain-specific monoclonal antibodies. METHODS: Tissue samples of tumor and adjacent normal mucosa obtained from patients with colorectal adenocarcinoma were stained with chain-specific monoclonal antibodies raised against synthetic peptides of individual alpha (IV) chains using an indirect immunofluorescence method. RESULTS: In the normal mucosa, alpha1 (IV), alpha2 (IV), alpha5 (IV), and alpha6 (IV) were found in the BM-delineating mucosal epithelium and the gland crypts, whereas alpha3 (IV) and alpha4 (IV) were limited to the BM of the luminal surface epithelium. In contrast, staining of alpha3-6 (IV) was rarely observed in the BM of cancer cells. Staining of alpha1 (IV) and alpha2 (IV) was reduced or lost from the cancer BM in relation to the degree of tumor differentiation: continuous staining in well-differentiated portions, discontinuous staining in moderately differentiated portions, and absence of staining in poorly differentiated portions. CONCLUSIONS: Our findings indicate that type IV collagen expression is altered in the BM of colorectal cancer as a result of changes of alpha (IV) chain expression, particularly alpha1 (IV) and alpha2 (IV), in relation to the degree of tumor differentiation.

Adenocarcinoma↗
PubMed2002

Randomized open trial for comparison of proton pump inhibitors in triple therapy for Helicobacter pylori infection in relation to CYP2C19 genotype.

BACKGROUND AND AIMS: Genetic polymorphism of cytochrome P450 (CYP) 2C19 influences the efficacy of Helicobacter pylori eradication therapy with a proton pump inhibitor (PPI) and amoxicillin. However, in triple therapy (PPI plus amoxicillin and clarithromycin), little is known about the impact of CYP2C19 polymorphism, or the use of rabeprazole, which is not well metabolized by CYP2C19. The efficacy of three PPI (omeprazole, lansoprazole, and rabeprazole) in a 1-week triple regimen were compared in relation to CYP2C19 polymorphism. METHOD: One hundred and eighty-three patients were randomized to receive one of the following regimens: amoxicillin 500 mg t.i.d., clarithromycin 200 mg t.i.d., and PPI (omeprazole 20 mg, lansoprazole 30 mg, or rabeprazole 10 mg) b.i.d. CYP2C19 polymorphism was analyzed by PCR restriction fragment length polymorphism. RESULTS: Intention-to-treat-based overall cure rates for omeprazole, lansoprazole or rabeprazole regimens were 83.1% (95% confidence interval (CI): 69-89%), 86.7% (CI: 75-93%), and 76.6% (CI: 64-85%), respectively, without significant difference. The cure rate of the rabeprazole regimen (but not the lansoprazole or omeprazole regimens) tended to be correlated with CYP2C19 genotypes (P = 0.076). In patients with a homozygous extensive metabolizer genotype, the per protocol-based cure rate with rabeprazole (62.5%) was significantly lower than that with lansoprazole (90.0%; P = 0.038). CONCLUSION: The overall cure rate of 1-week triple therapy for H. pylori eradication was not significantly different between regimens with omeprazole, lansoprazole or rabeprazole, but the impact of CYP2C19 genetic polymorphism on the cure rate appeared to differ between these PPI.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2002

Advances in the development of a reliable assay for the measurement of stool decay-accelerating factor in the detection of colorectal cancer.

We have previously shown that stool concentrations of decay-accelerating factor (DAF; CD55), a membrane-bound complement-regulatory protein, are significantly elevated in patients with colorectal cancer and that the measurement of stool DAF may be a valuable test for the detection of colorectal cancer. Accordingly, we are working to develop a clinically useful immunoassay for fecal DAF. A requirement for such assay is a plentiful and reliable supply of anti-DAF antibodies. We developed a sandwich enzyme-linked immunosorbent assay (ELISA) for DAF in stool specimens, using two monoclonal anti-DAF antibodies recognizing different epitopes on the DAF molecule. When we first used a biotin-labeled antibody and enzyme-linked streptavidin method, we often observed stool interference, probably due to the presence of a substance(s) with biotin activity which non-specifically bound to the Fc portion of IgG of the first anti-DAF antibody on the ELISA wells. By the use of inorganic salts in the sample-dilution buffer and HRP-labeled anti-DAF as second antibody, we circumvented the stool interference and established that the new ELISA system could reliably measure DAF at low concentrations in stool specimens. Because the new assay system uses only monoclonal antibodies, we can now consistently supply ample amounts of antibodies for routine measurement of stool DAF.

Adolescent↗
PubMed2002

Identification of a target antigen recognized by a mouse monoclonal antibody to the bile canalicular surface of rat hepatocytes with a random phage display library.

We developed a monoclonal antibody (MoAb) (clone 5E8) against an antigen on the bile canalicular membrane of rat hepatocyte. By immunoblotting, MoAb 5E8 detected a band of 110 kD. In this study, we used the phage display technique to identify the target antigen recognized by MoAb 5E8. We screened a random phage display library expressing 12-mer peptide sequences and identified a peptide sequence, FHFNPYTGHPLT, as an epitope. We compared this peptide sequence with those of dipeptidyl peptidase IV (DPP IV, E.C.3.4.14.5) and Cell-CAM105, which proteins were located by a database search based on the information of tissue localization and approximate molecular weight of the MoAb 5E8 antigen, and sequence similarity with a region in DPP IV (amino acids 225-233) but not with Cell-CAM105 was found. In addition, we immunohistochemically stained various tissues (liver, small intestine, and kidney) of Japanese Fischer 344 rats, known to be deficient for DPP IV, with MoAb 5E8 and showed that the expression of MoAb 5E8 antigen was negligible or weak. In contrast, tissues sampled from the same organs of Sprague-Dawley rats, known to express DPP IV, were positively stained. These findings suggest that the antigen recognized by MoAb 5E8 is DDPIV and its major epitope is located in amino acids at positions 225-233.

Amino Acid Sequence↗