Eosinophil peroxidase signals via epidermal growth factor-2 to induce cell proliferation.
AffiliationDepartment of Medicine, Education and Research Centre, Royal College of Surgeons in Ireland, Dublin, Ireland. firstname.lastname@example.org
MeSHActive Transport, Cell Nucleus
Cyclin-Dependent Kinase Inhibitor p27
Epidermal Growth Factor
Focal Adhesion Protein-Tyrosine Kinases
MAP Kinase Signaling System
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CitationEosinophil peroxidase signals via epidermal growth factor-2 to induce cell proliferation. 2011, 45 (5):946-52 Am. J. Respir. Cell Mol. Biol.
JournalAmerican journal of respiratory cell and molecular biology
AbstractEosinophils exert many of their inflammatory effects in allergic disorders through the degranulation and release of intracellular mediators, including a set of cationic granule proteins that include eosinophil peroxidase. Studies suggest that eosinophils are involved in remodeling. In previous studies, we showed that eosinophil granule proteins activate mitogen-activated protein kinase signaling. In this study, we investigated the receptor mediating eosinophil peroxidase-induced signaling and downstream effects. Human cholinergic neuroblastoma IMR32 and murine melanoma B16.F10 cultures, real-time polymerase chain reaction, immunoprecipitations, and Western blotting were used in the study. We showed that eosinophil peroxidase caused a sustained increase in both the expression of epidermal growth factor-2 (HER2) and its phosphorylation at tyrosine 1248, with the consequent activation of extracellular-regulated kinase 1/2. This, in turn, promoted a focal adhesion kinase-dependent egress of the cyclin-dependent kinase inhibitor p27(kip) from the nucleus to the cytoplasm. Eosinophil peroxidase induced a HER2-dependent up-regulation of cell proliferation, indicated by an up-regulation of the nuclear proliferation marker Ki67. This study identifies HER2 as a novel mediator of eosinophil peroxidase signaling. The results show that eosinophil peroxidase, at noncytotoxic levels, can drive cell-cycle progression and proliferation, and contribute to tissue remodeling and cell turnover in airway disease. Because eosinophils are a feature of many cancers, these findings also suggest a role for eosinophils in tumorigenesis.