Faculty Profiles - NAKAYAMA Masaaki

Enhanced Expression of CXCL13 in Human Helicobacter pylori-Associated Gastritis (共著) Reviewed

Yujiro Nakashima, Hajime Isomoto, Kayoko Matsushima, Akira Yoshida, Toshiyuki Nakayama, Masaaki Nakayama, Junzo Hisatsune, Tatsuki Ichikawa, Fuminaoa Takeshima, TomayoshiHayashi, Kazuhiko Nakao, Toshiya Hirayama, and Shigeru Kohno

Digestive Diseases and Sciences 2011.11

Enhanced Expression of CXCL13 in Human Helicobacter pylori-Associated Gastritis

Yujiro Nakashima, Hajime Isomoto, Kayoko Matsushima, Akira Yoshida, Toshiyuki Nakayama, Masaaki Nakayama, Junzo Hisatsune, Tatsuki Ichikawa, Fuminao Takeshima, Tomayoshi Hayashi, Kazuhiko Nakao, Toshiya Hirayama, Shigeru Kohno

DIGESTIVE DISEASES AND SCIENCES 56 ( 10 ) 2887 - 2894 2011.10

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

Chemokine CXC ligand 13 (CXCL13) and CXC receptor type 5 (CXCR5) are constitutively expressed in tertiary lymphoid follicles where the CXCL13/CXCR5 system regulates B lymphocytes homing. In this study, we sought to examine CXCL13 expression in the H. pylori-infected and -uninfected gastric mucosa and to elucidate the implication in the pathogenesis of HAG in humans.Using endoscopic biopsies taken from the gastric antrum of 29 subjects infected with Helicobacter pylori and 22 uninfected subjects, mucosal CXCL13 mRNA and protein levels were measured by real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively.The CXCL13 expression levels were significantly more elevated in H. pylori-positive patients than uninfected ones. The CXCL13 expression levels correlated with the degree of chronic gastritis and bacterial colonization. Immunohistochemistry and in vitro infection assay showed that CXCL13 was not produced by the gastric epithelium, but the alpha-smooth muscle antigen expressing mesenchymal cells were the possible source of CXCL13 within H. pylori-infected gastric mucosa. CXCR5 immunostaining was seen in the CD20-positive lymphoid aggregates.The enhanced induction of CXCL13 may be involved in the pathogenesis of H. pylori-associated gastritis.

DOI： 10.1007/s10620-011-1717-8

Helicobacter pylori VacA reduces the cellular expression of STAT3 and pro-survival Bcl-2 family proteins, Bcl-2 and Bcl-XL, leading to apoptosis in gastric epithelial cells (共著) Reviewed

Ayako Matsumoto, Hajime Isomoto, Masaaki Nakayama, Junzo Hisatsune, Yoshito Nishi, Yujiro Nakashima, Kayoko Matsushima, Hisao Kurazono, Kazuhiko Nakao, Toshiya Hirayama, and Shigeru Kohno

Digestive Diseases and Sciences 2011.4

Helicobacter pylori VacA Reduces the Cellular Expression of STAT3 and Pro-survival Bcl-2 Family Proteins, Bcl-2 and Bcl-X-L, Leading to Apoptosis in Gastric Epithelial Cells

Ayako Matsumoto, Hajime Isomoto, Masaaki Nakayama, Junzo Hisatsune, Yoshito Nishi, Yujiro Nakashima, Kayoko Matsushima, Hisao Kurazono, Kazuhiko Nakao, Toshiya Hirayama, Shigeru Kohno

DIGESTIVE DISEASES AND SCIENCES 56 ( 4 ) 999 - 1006 2011.4

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

Helicobacter pylori vacuolating cytotoxin, VacA, stimulates apoptosis via a mitochondria-dependent pathway. VacA induces apoptosis via activation of the pro-apoptotic B-cell lymphoma (Bcl)-2 family proteins, Bcl-2-associated X protein (Bax) and Bcl-2 homologous antagonist/killer (Bak), while the implication of such pro-survival Bcl-2 family members as Bcl-2 and Bcl-X-L in the VacA-induced apoptosis remains unknown. Signal transduction and activator of transcription 3 (STAT3) is a pivotal transcription factor that upregulates Bcl-2 and Bcl-X-L.This study was conducted to elicit the implication of STAT3 and pro-survival Bcl-2 and Bcl-X-L in the intrinsic apoptosis.Immunoblot and reverse transcriptase real-time polymerase chain reaction (RT-PCR) were employed to assess the cellular expression of STAT3, Bcl-2, and Bcl-X-L in response to purified VacA in gastric adenocarcinoma cell lines. VacA-induced apoptosis was quantitated morphologically following knockdown by each specific small interfering RNA (siRNA) or in the presence of pharmacological inhibitors.VacA reduced STAT3, Bcl-2, and Bcl-X-L expression in a dose-dependent manner. Knockdown of STAT3, Bcl-2, and Bcl-X-L by siRNA induced apoptosis to a similar extent in the case of sufficient VacA inoculation. The VacA-mediated reduction of STAT3 expression was independent of cellular vacuolization, since a vacuolar-type ATPase inhibitor, bafilomycin A1, did not inhibit VacA-induced reduction of STAT3, Bcl-2, and Bcl-X-L expression. Instead, a c-JUN NH2-terminal kinase (JNK) inhibitor, SP600125, restored the VacA-induced reduction of STAT3 expression to the basal level.VacA-induced apoptosis may be, in part, implicated in the reduction of STAT3 linking to the downregulation of Bcl-2 and Bcl-X-L, in association with JNK activity.

DOI： 10.1007/s10620-010-1420-1

MicroRNA signatures in Helicobacter pylori-infected gastric mucosa (共著) Reviewed

Kayoko Matsushima, Hajime Isomoto, Naoki Inoue, Toshiyuki Nakayama, Tomayoshi Hayashi, Masaaki Nakayama, Kazuhiko Nakao, Toshiya Hirayama, and Shigeru Kohno

International journal of cancer 2011.1

Enhanced expression of CCL20 in human Helicobacter pylori-associated gastritis Reviewed

YOSHIDA A

Clin. Immunol. 130 290 - 297 2009.3

Helicobacter pylori VacA-induced inhibition of GSK3 through the PI3K/Akt signaling pathway Reviewed

NAKAYAMA M.

J. Biol. Chem. 284 ( 3 ) 1612 - 1619 2009.1

Molecular Characterization of Helicobacter pylori VacA Induction of IL-8 in U937 Cells Reveals a Prominent Role for p38MAPK in Activating Transcription Factor-2, cAMP Response Element Binding Protein, and NF-κB Activation (共著) Reviewed

Junzo Hisatsune, Masaaki Nakayama, Hajime Isomoto, Hisao Kurazono, Naofumi Mukaida, Asish K. Mukhopadhyay, Takeshi Azuma, Yoshio Yamaoka, Jan Sap, Eiki Yamasaki, Kinnosuke Yahiro, Joel Moss, and Toshiya Hirayama

The Journal of Immunology 180 ( 7 ) 5017 - 5027 2008.4

Molecular characterization of Helicobacter pylori VacA induction of IL-8 in U937 cells reveals a prominent role for p38MAPK in activating transcription factor-2, cAMP response element binding protein, and NF-kappa B activation Reviewed

JOURNAL OF IMMUNOLOGY 180 ( 7 ) 5017 - 5027 2008.4

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER ASSOC IMMUNOLOGISTS

Helicobacterpylori VacA induces multiple effects on susceptible cells, including vacuolation, mitochondrial damage, inhibition of cell growth, and enhanced cyclooxygenase-2 expression. To assess the ability of H. pylori to modulate the production of inflammatory mediators, we examined the mechanisms by which VacA enhanced IL-8 production by promonocytic U937 cells, which demonstrated the greatest VacA-induced IL-8 release of the cells tested. Inhibitors of p38 MAPK (SB203580), ERK1/2 (PD98059), IKBa ((E)-3-(4-methylphenyisulfonyl)-2-propenenitrile), Ca2+ entry (SKF96365), and intracellular Ca 21 channels (dantrolene) blocked VacA-induced IL-8 production. Furthermore, an intracellular Ca2+ chelator (BAPTA-AM), which inhibited VacA-activated p38 MAPK, caused a dose-dependent reduction in VacA-induced IL-8 secretion by U937 cells, implying a role for intracellular Ca 21 in mediating activation of MAPK and the canonical NF-kappa B pathway. VacA stimulated translocation of NF-kappa Bp65 to the nucleus, consistent with enhancement of IL-8 expression by activation of the NF-kappa B pathway. In addition, small interfering RNA of activating transcription factor (ATF)-2 or CREB, which is a p38MAPK substrate and binds to the AP-1 site of the IL-8 promoter, inhibited VacA-induced IL-8 production. VacA activated an IL-8 promoter containing an NF-IL-6 site, but not a mutated AP-1 or NF-kappa B site, suggesting direct involvement of the ATF-2/CREB binding region or NF-kappa B-binding regions in VacA-induced IL-8 promoter activation. Thus, in U937 cells, VacA directly increases IL-8 production by activation of the p38 MAPK via intracellular Ca2+ release, leading to activation of the transcription factors, ATF-2, CREB, and NF-kappa B.

DOI： 10.4049/jimmunol.180.7.5017

Helicobacter pylori VacA enhances prostaglandin E2 production through induction of cyclooxygenase 2 expression via a p38 mitogen-activated protein kinase/activating transcription factor 2 cascade in AZ-521 cells

Junzo Hisatsune, Eiki Yamasaki, Masaaki Nakayama, Daisuke Shirasaka, Hisao Kurazono, Yohtaro Katagata, Hiroyasu Inoue, Jiahuai Han, Jan Sap, Kinnosuke Yahiro, Joel Moss, Toshiya Hirayama

Infection and Immunity 75 ( 9 ) 4472 - 4481 2007.9

Language：English Publishing type：Research paper (scientific journal)

Treatment of AZ-521 cells with Helicobacter pylori VacA increased cyclooxygenase 2 (COX-2) mRNA in a time- and dose-dependent manner. A p38 mitogen-activated protein kinase (MAPK) inhibitor, SB203580, blocked elevation of COX-2 mRNA levels, whereas PD98059, which blocks the Erk1/2 cascade, partially suppressed the increase. Consistent with involvement of p38 MAPK, VacA-induced accumulation of COX-2 mRNA was reduced in AZ-521 cells overexpressing a dominant-negative p38 MAPK (DN-p38). Phosphatidylinositol- specific phospholipase C, which inhibits VacA-induced p38 MAPK activation, blocked VacA-induced COX-2 expression. In parallel with COX-2 expression, VacA increased prostaglandin E2 (PGE2) production, which was inhibited by SB203580 and NS-398, a COX-2 inhibitor. VacA-induced PGE 2 production was markedly attenuated in AZ-521 cells stably expressing DN-p38. VacA increased transcription of a COX-2 promoter reporter gene and activated a COX-2 promoter containing mutated NF-κB or NF-interleukin-6 sites but not a mutated cis-acting replication element (CRE) site, suggesting direct involvement of the activating transcription factor 2 (ATF-2)/CREB-binding region in VacA-induced COX-2 promoter activation. The reduction of ATF-2 expression in AZ-521 cells transformed with ATF-2-small interfering RNA duplexes resulted in suppression of COX-2 expression. Thus, VacA enhances PGE2 production by AZ-521 cells through induction of COX-2 expression via the p38 MAPK/ATF-2 cascade, leading to activation of the CRE site in the COX-2 promoter. Copyright © 2007, American Society for Microbiology. All Rights Reserved.

DOI： 10.1128/IAI.00500-07

Scopus

Helicobacter pylori Vacuolating Cytotoxin Induces Activation of the Proapoptotic Proteins Bax and Bak, Leading to Cytochrome c Release and Cell Death, Independent of Vacuolation Reviewed

Helicobacter pylori VacA enhances PGE2 production through induction of COX-2 expression via a p38 MAP kinase/ ATF-2 cascade in AZ-521 cells (共著) Reviewed

Junzo Hisatsune, Eiki Yamasaki, Masaaki Nakayama, Daisuke Shirasaka, Hisao Kurazono, Yohtaro Katagata, Hiroyasu Inoue, Jiahuai Han, Jan Sap, Kinnosuke Yahiro, Joel Moss, and Toshiya Hirayama

Infection and Immunity 75 ( 9 ) 4472 - 4481 2007.6

Helicobacter pylori VacA clustering in lipid rafts, mediated by its receptor, RPTPβ, is required for VacA-induced vacuolation in AZ-521 cells. Reviewed

Masaaki Nakayama, Akihiro Wada, Junzo Hisatsune, Eiki Yamasaki, Yoshito Nishi, Kinnosuke Yahiro, Hisao Kurazono, Joel Moss, and Toshiya Hirayama

Infection and Immunity 74 ( 12 ) 6571 - 6580 2006.12

Eiki Yamasaki, Akihiro Wada, Atsushi Kumatori, Ichiro Nakagawa, Junko Funao, Masaaki Nakayama, Junzo Hisatsune, Miyuki Kimura, Joel Moss, Toshiya Hirayama

Journal of Biological Chemistry 281 ( 16 ) 11250 - 11259 2006.4

[Structure and intoxication of VacA].

Toshiya Hirayama, Akihiro Wada, Masaaki Nakayama, Yoshito Nishi, Jyunzo Hisatsune

Nihon rinsho. Japanese journal of clinical medicine 63 Suppl 11 53 - 7 2005.11

Cytotoxicity and recognition of receptor-like protein tyrosine phosphatases, RPTPalpha and RPTPbeta, by Helicobacter pylori m2VacA. Reviewed International journal

Blanquita B De Guzman, Junzo Hisatsune, Masaaki Nakayama, Kinnosuke Yahiro, Akihiro Wada, Eiki Yamasaki, Yoshito Nishi, Shiho Yamazaki, Takeshi Azuma, Yoshiyuki Ito, Masahiro Ohtani, Thea van der Wijk, Jeroen den Hertog, Joel Moss, Toshiya Hirayama

Cellular microbiology 7 ( 9 ) 1285 - 1293 2005.9

Language：English Publishing type：Research paper (scientific journal)

Helicobacter pylori vacuolating cytotoxin, VacA, induces vacuolation in mammalian cell lines. Sequence differences in the middle of VacA molecules define two families, termed m1VacA and m2VacA, which differ in cell specificity. Similar to m1VacA, m2VacA is activated by acid or alkali, which enhances its binding to cells. Immunoprecipitation experiments showed that, in AZ-521 cells, activated m2VacA, similar to m1VacA, binds to two receptor-like protein tyrosine phosphatases, RPTPalpha and RPTPbeta suggesting that activated m2VacA as well as m1VacA may contribute to gastrointestinal disease following H. pylori infection. G401 cells express RPTPalpha, not RPTPbeta, and responded to both m1VacA and m2VacA. HeLa cells likewise expressed RPTPalpha, not RPTPbeta, but, in contrast to other cell lines, responded poorly to m2VacA. m1VacA associated with RPTPalpha of HeLa cells to an extent similar to that in other toxin-sensitive cells, whereas activated m2VacA bound HeLa cell RPTPalpha less well, consistent with its low vacuolating activity against these cells. The molecular mass of RPTPalpha from HeLa cells is less than that of the protein from G401 cells, although their extracellular amino acid sequences are virtually identical, with only two amino acid differences noted. Different post-translational modifications of RPTPalpha in HeLa cells may be responsible for the reduced susceptibility to m2VacA.

Essential domain of receptor tyrosine phosphatase beta (RPTPbeta) for interaction with Helicobacter pylori vacuolating cytotoxin. Reviewed International journal

Kinnosuke Yahiro, Akihiro Wada, Eiki Yamasaki, Masaaki Nakayama, Yoshito Nishi, Jyunzou Hisatsune, Naoko Morinaga, Jan Sap, Masatoshi Noda, Joel Moss, Toshiya Hirayama

The Journal of biological chemistry 279 ( 49 ) 51013 - 51021 2004.12

Language：English Publishing type：Research paper (scientific journal)

Helicobacter pylori produces a potent exotoxin, VacA, which causes progressive vacuolation as well as gastric injury. Although VacA was able to interact with two receptor-like protein tyrosine phosphatases, RPTPbeta and RPTPalpha, RPTPbeta was found to be responsible for gastric damage caused by VacA. To define the region of RPTPbeta involved in VacA binding, we made mutants of human cDNA RPTPbeta-B, a short receptor form of RPTPbeta. Immunoprecipitation experiments to assess VacA binding to RPTPbeta-B mutants indicated that five residues (QTTQP) at positions 747-751 of the extracellular domain of RPTPbeta-B (which is commonly retained in RPTPbeta-A, a long form of RPTPbeta) play a crucial role in its interaction with VacA, resulting in vacuolation as well as Git-1 phosphorylation. Transfected cells expressing deletion mutant Delta752, which lacks QTTQP, or the double point mutant Delta747 (T748A,T749A) had diminished vacuolation in response to VacA. Treatment of RPTPbeta-B and Delta747 (which have QTTQP at 747-751) with neuraminidase and O-glycosidase diminished their VacA binding, whereas chondroitinase ABC did not have an effect. No inhibitory effect of pleiotrophin, a natural RPTPbeta ligand, on VacA binding to RPTPbeta-B or Delta747 was observed, supporting the conclusion that the extracellular region of RPTPbeta-B responsible for VacA binding is different from that involved in binding pleiotrophin. These data define the region in the RPTPbeta extracellular domain critical for VacA binding, in particular the sequence QTTQP at positions 747-751 with crucial threonines at positions 748 and 749 and are consistent with a role for terminal sialic acids possibly because of threonine glycosylation.