Helicobacter pylori Induces IκB Kinase α Nuclear Translocation and Chemokine Production in Gastric Epithelial Cells

ABSTRACT NF-κB is an important transcriptional factor that is involved in multiple cellular responses, such as inflammation and antiapoptosis. IκB kinase α (IKKα) and IKKβ, which are critical regulators of NF-κB activity, possess various mechanisms for NF-κB activation. This variability in NF-κB signaling may be associated with distinct inflammatory responses in specific cell types. The gastric pathogen Helicobacter pylori is known to activate NF-κB. However, the role of IKK in H. pylori infection remains unclear. In this report, we show that H. pylori activates both IKKα and IKKβ in gastric cancer cells and enhances NF-κB signaling in distinct manners. We found that IKKβ acted as an IκBα kinase during H. pylori infection, whereas IKKα did not. H. pylori induced IKKα nuclear translocation in time-, multiplicity of infection-, and cag pathogenicity island-dependent manners. In contrast, p100 processing, which is a known IKKα activity induced by several cytokines, was not induced by H. pylori. Both IKKs were responsible for chemokine secretion by infected cells. However, the antiapoptotic effect of H. pylori was merely transduced by IKKβ. Microarray analysis and real-time PCR indicated that both IKKs were involved in the transcriptional activation of genes associated with inflammation, antiapoptosis, and signal transduction. Our results indicate that H. pylori activates NF-κB via both IKKα and IKKβ using distinct mechanisms. IKKα nuclear translocation induced by H. pylori is indispensable for appropriate inflammatory responses but not for antiapoptosis, which suggests a critical role for IKKα in gastritis development.

[1]  S. Fukuda,et al.  The antiapoptosis protein survivin is associated with cell cycle entry of normal cord blood CD34(+) cells and modulates cell cycle and proliferation of mouse hematopoietic progenitor cells. , 2002, Blood.

[2]  E. Zandi,et al.  Bridging the Gap: Composition, Regulation, and Physiological Function of the IκB Kinase Complex , 1999, Molecular and Cellular Biology.

[3]  T. Deerinck,et al.  Abnormal Morphogenesis But Intact IKK Activation in Mice Lacking the IKKα Subunit of IκB Kinase , 1999 .

[4]  D. Green,et al.  The lymphotoxin-beta receptor induces different patterns of gene expression via two NF-kappaB pathways. , 2002, Immunity.

[5]  R. Surabhi,et al.  TAK1 is Critical for IκB Kinase-mediated Activation of the NF-κB Pathway , 2003 .

[6]  B E Dunn,et al.  Helicobacter pylori , 1997, Clinical microbiology reviews.

[7]  I. Verma,et al.  NF-κB regulation in the immune system , 2002, Nature Reviews Immunology.

[8]  E. Zandi,et al.  IKK-γ is an essential regulatory subunit of the IκB kinase complex , 1998, Nature.

[9]  R. Rappuoli,et al.  Helicobacter pylori virulence and genetic geography. , 1999, Science.

[10]  K. Ory,et al.  Apoptosis inhibition mediated by medroxyprogesterone acetate treatment of breast cancer cell lines , 2001, Breast Cancer Research and Treatment.

[11]  S. Akira,et al.  Toll-like receptors and innate immunity , 2006, Journal of Molecular Medicine.

[12]  M. Karin,et al.  The two NF-κB activation pathways and their role in innate and adaptive immunity , 2004 .

[13]  T. Kawabe,et al.  Helicobacter pylori Induces Antiapoptosis through Nuclear Factor–κB Activation , 2003 .

[14]  R. Peek,et al.  Differential activation of mitogen-activated protein kinases in AGS gastric epithelial cells by cag+ and cag- Helicobacter pylori. , 1999, Journal of immunology.

[15]  B. Mordmüller,et al.  Lymphotoxin and lipopolysaccharide induce NF‐κB‐p52 generation by a co‐translational mechanism , 2003, EMBO reports.

[16]  E. Zandi,et al.  The IκB Kinase Complex (IKK) Contains Two Kinase Subunits, IKKα and IKKβ, Necessary for IκB Phosphorylation and NF-κB Activation , 1997, Cell.

[17]  M. Karin,et al.  Inhibition of JNK activation through NF-κB target genes , 2001, Nature.

[18]  T. Kawabe,et al.  Helicobacter pylori Activates NF-κB via the Alternative Pathway in B Lymphocytes , 2005, The Journal of Immunology.

[19]  M. Upton,et al.  Helicobacter pylori infection activates NF-kappa B in gastric epithelial cells. , 1997, Gastroenterology.

[20]  S. Akira,et al.  Limb and skin abnormalities in mice lacking IKKalpha. , 1999, Science.

[21]  W. Greene,et al.  Shaping the nuclear action of NF-κB , 2004, Nature Reviews Molecular Cell Biology.

[22]  M. Blaser,et al.  Helicobacter pylori and gastrointestinal tract adenocarcinomas , 2002, Nature Reviews Cancer.

[23]  Y. Yamaji,et al.  H. pylori activates NF-κB through a signaling pathway involving IκB kinases, NF-κB—inducing kinase, TRAF2, and TRAF6 in gastric cancer cells☆ , 2000 .

[24]  M. Karin,et al.  Phosphorylation meets ubiquitination: the control of NF-[kappa]B activity. , 2000, Annual review of immunology.

[25]  T. Deerinck,et al.  The IKKβ Subunit of IκB Kinase (IKK) is Essential for Nuclear Factor κB Activation and Prevention of Apoptosis , 1999, The Journal of experimental medicine.

[26]  M. Karin,et al.  IκB kinase-α acts in the epidermis to control skeletal and craniofacial morphogenesis , 2004, Nature.

[27]  Michael Karin,et al.  NF-κB in cancer: from innocent bystander to major culprit , 2002, Nature Reviews Cancer.

[28]  Michael Karin,et al.  Activation by IKKα of a Second, Evolutionary Conserved, NF-κB Signaling Pathway , 2001, Science.

[29]  J. Ninomiya-Tsuji,et al.  The kinase TAK1 can activate the NIK-IκB as well as the MAP kinase cascade in the IL-1 signalling pathway , 1999, Nature.

[30]  Y. Masuho,et al.  cDNA microarray analysis of Helicobacter pylori-mediated alteration of gene expression in gastric cancer cells. , 2001, Biochemical and biophysical research communications.

[31]  M. Blaser,et al.  Infection with Helicobacter pylori strains possessing cagA is associated with an increased risk of developing adenocarcinoma of the stomach. , 1995, Cancer research.

[32]  R. Gaynor,et al.  Histone H3 phosphorylation by IKK-alpha is critical for cytokine-induced gene expression. , 2003, Nature.

[33]  Matthias Mann,et al.  IKK-1 and IKK-2: Cytokine-Activated IκB Kinases Essential for NF-κB Activation , 1997 .

[34]  D. Tompkins,et al.  Mucosal IgA recognition of Helicobacter pylori 120 kDa protein, peptic ulceration, and gastric pathology , 1991, The Lancet.

[35]  R. Gaynor,et al.  Histone H3 phosphorylation by IKK-α is critical for cytokine-induced gene expression , 2003, Nature.

[36]  Mike Rothe,et al.  IκB Kinase-β: NF-κB Activation and Complex Formation with IκB Kinase-α and NIK , 1997 .

[37]  Y. Yamaji,et al.  Helicobacter pylori Activates the Cyclin D1 Gene through Mitogen- Activated Protein Kinase Pathway in Gastric Cancer Cells , 2001, Infection and Immunity.

[38]  M. Borodovsky,et al.  cag, a pathogenicity island of Helicobacter pylori, encodes type I-specific and disease-associated virulence factors. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[39]  Inder M. Verma,et al.  Severe Liver Degeneration in Mice Lacking the IκB Kinase 2 Gene , 1999 .

[40]  Brian D. Strahl,et al.  A nucleosomal function for IκB kinase-α in NF-κB-dependent gene expression , 2003, Nature.

[41]  Leif E. Peterson,et al.  Screening of gene expression profiles in gastric epithelial cells induced by Helicobacter pylori using microarray analysis , 2002, Alimentary pharmacology & therapeutics.

[42]  Y. Shiratori,et al.  Distinct Mechanism of Helicobacter pylori-mediated NF-κB Activation between Gastric Cancer Cells and Monocytic Cells* , 2001, The Journal of Biological Chemistry.

[43]  P. Robinson,et al.  cDNA Array Analysis of cag Pathogenicity Island-Associated Helicobacter pylori Epithelial Cell Response Genes , 2001, Infection and Immunity.

[44]  S. Falkow,et al.  Cag pathogenicity island-specific responses of gastric epithelial cells to Helicobacter pylori infection , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[45]  David M. Rothwarf,et al.  A cytokine-responsive IκB kinase that activates the transcription factor NF-κB , 1997, Nature.

[46]  Sankar Ghosh,et al.  Signaling to NF-kappaB. , 2004, Genes & development.

[47]  M. Naumann,et al.  p21-activated Kinase 1 Activates the Nuclear Factor κB (NF-κB)-inducing Kinase-IκB Kinases NF-κB Pathway and Proinflammatory Cytokines in Helicobacter pyloriInfection* , 2000, The Journal of Biological Chemistry.

[48]  D. Green,et al.  The Lymphotoxin-β Receptor Induces Different Patterns of Gene Expression via Two NF-κB Pathways , 2002 .

[49]  Michael Karin,et al.  The IKK NF-κB system: a treasure trove for drug development , 2004, Nature Reviews Drug Discovery.

[50]  Y. Yamaoka,et al.  Chemokines in the gastric mucosa in Helicobacter pylori infection , 1998, Gut.

[51]  E. Zandi,et al.  IKK-gamma is an essential regulatory subunit of the IkappaB kinase complex. , 1998, Nature.

[52]  M. Chamaillard,et al.  NOD-LRR proteins: role in host-microbial interactions and inflammatory disease. , 2005, Annual review of biochemistry.

[53]  D. Goeddel,et al.  Identification and Characterization of an IκB Kinase , 1997, Cell.