Syed Faisal Zaidi1,2,3, Alaa Refaat4,5, Yue Zhou6, Jibran Sualeh Muhammad1, Myoung-Sook Shin4, Ikuo Saiki4, Hiroaki Sakurai6, Toshiro Sugiyama1. 1. Department of Gastroenterology and Hematology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan. 2. Department of Basic Medical Sciences, College of Medicine, King Saud bin Abdulaziz University of Health Sciences, Jeddah, Saudi Arabia. 3. Department of Biological and Biomedical Sciences, Faculty of Health Sciences, Aga Khan University, Karachi, Pakistan. 4. Division of Pathogenic Biochemistry, Institute of Natural Medicine, University of Toyama, Toyama, Japan. 5. Center for Aging and Associated Diseases, Zewail City of Science and Technology, Giza, Egypt. 6. Department of Cancer Cell Biology, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, Toyama, Japan.
Abstract
BACKGROUND: The interaction of Helicobacter pylori with gastric epithelial cells can result in the activation of transcription factor NF-κB via TGF-β-activated kinase 1 (TAK1). In this study, we have demonstrated the role of H. pylori in the activation of EGFR via TAK1-mediated phosphorylation of p38. MATERIALS AND METHODS: Gastric epithelial AGS or MKN-45 cells were co-cultured with wild-type or cagA(-) H. pylori strains. H. pylori was added to the cells, and the activation of EGFR, p65 (NF-κB) subunit, p38, ERK, and TAK1 was examined by Western blotting. Infected cells were pretreated with or without ligands, chemical inhibitors, anti-HB-EGF antibody, and siRNAs to evaluate the effects on phosphorylation of various EGFR residues. Fluorescence microscopy and flow cytometry were performed to detect the internalization of EGFR. RESULTS: Incubating cells with wild-type and CagA(-) H. pylori strains resulted in the rapid and transient phosphorylation of serine residues of EGFR. RNAi experiments using siRNA against TAK1 and p38 pathways blocked the phosphorylation of serine residue. Immunofluorescence and flow cytometry revealed that EGFR was internalized in H. pylori-infected cells after EGFR phosphorylation in a p38-dependent manner. In contrast, pretreatment with gefitinib and anti-HB-EGF antibody did not block both the phosphorylation and internalization of EGFR. CONCLUSION: Helicobacter pylori induces internalization of EGFR via novel TAK1-p38-serine activation pathway which is independent of HB-EGF. The interaction between TAK1 and EGFR in H. pylori-infected cells might open new dimensions in understanding H. pylori-associated gastric carcinogenesis.
BACKGROUND: The interaction of Helicobacter pylori with gastric epithelial cells can result in the activation of transcription factor NF-κB via TGF-β-activated kinase 1 (TAK1). In this study, we have demonstrated the role of H. pylori in the activation of EGFR via TAK1-mediated phosphorylation of p38. MATERIALS AND METHODS: Gastric epithelial AGS or MKN-45 cells were co-cultured with wild-type or cagA(-) H. pylori strains. H. pylori was added to the cells, and the activation of EGFR, p65 (NF-κB) subunit, p38, ERK, and TAK1 was examined by Western blotting. Infected cells were pretreated with or without ligands, chemical inhibitors, anti-HB-EGF antibody, and siRNAs to evaluate the effects on phosphorylation of various EGFR residues. Fluorescence microscopy and flow cytometry were performed to detect the internalization of EGFR. RESULTS: Incubating cells with wild-type and CagA(-) H. pylori strains resulted in the rapid and transient phosphorylation of serine residues of EGFR. RNAi experiments using siRNA against TAK1 and p38 pathways blocked the phosphorylation of serine residue. Immunofluorescence and flow cytometry revealed that EGFR was internalized in H. pylori-infected cells after EGFR phosphorylation in a p38-dependent manner. In contrast, pretreatment with gefitinib and anti-HB-EGF antibody did not block both the phosphorylation and internalization of EGFR. CONCLUSION:Helicobacter pylori induces internalization of EGFR via novel TAK1-p38-serine activation pathway which is independent of HB-EGF. The interaction between TAK1 and EGFR in H. pylori-infected cells might open new dimensions in understanding H. pylori-associated gastric carcinogenesis.
Authors: Jibran Sualeh Muhammad; Naveed Ahmed Khan; Sutherland K Maciver; Ahmad M Alharbi; Hasan Alfahemi; Ruqaiyyah Siddiqui Journal: Antibiotics (Basel) Date: 2022-06-16
Authors: Marina Leite; Miguel S Marques; Joana Melo; Marta T Pinto; Bruno Cavadas; Miguel Aroso; Maria Gomez-Lazaro; Raquel Seruca; Ceu Figueiredo Journal: Cells Date: 2020-02-24 Impact factor: 6.600