Hypoxia modulates human eosinophil function
Open Access
- 19 July 2010
- journal article
- Published by Springer Science and Business Media LLC in Clinical and Molecular Allergy
- Vol. 8 (1), 10
- https://doi.org/10.1186/1476-7961-8-10
Abstract
Background Eosinophils are involved in various inflammatory processes including allergic inflammation during which angiogenesis has been documented. Angiogenesis is most likely connected to the hypoxia which characterizes inflamed tissues. Eosinophils produce VEGF and are pro-angiogenic. However, to the best of our knowledge no study has been performed to verify the existence of a direct link between eosinophils, hypoxia and angiogenesis in allergic inflammation. Objective To characterize eosinophil function and angiogenic potential under hypoxic conditions. Methods Human peripheral blood eosinophils were cultured in normoxic or hypoxic conditions with or without cytokines. Viability and apoptosis were assessed by Annexin V/PI staining. Anti- or pro-apoptotic protein levels, HIF-1α levels and MAPK phosphorylation were analyzed by immunoblot analysis. Angiogenic mediator release was evaluated by ELISA. Results Hypoxic eosinophils were more viable than normoxic ones after up to three days. In addition in hypoxia, anti-apoptotic Bcl-XL protein levels increased more than pro-apoptotic Bax levels. Hypoxia increased VEGF and IL-8 release. In hypoxic eosinophils high levels of HIF-1α were observed, particularly in the presence of GM-CSF. MAPK, particularly ERK1/2 inhibitors, decreased hypoxia-mediated VEGF release and HIF-1α expression. Conclusion Eosinophils respond to hypoxia by up-regulation of survival and of some of their pro-angiogenic functions indicating a correlation between eosinophilic inflammation and angiogenesis.Keywords
This publication has 36 references indexed in Scilit:
- Osteopontin is expressed and functional in human eosinophilsAllergy, 2010
- THE EOSINOPHILAnnual Review of Immunology, 2006
- The inhibitory receptor IRp60 (CD300a) suppresses the effects of IL-5, GM-CSF, and eotaxin on human peripheral blood eosinophilsBlood, 2006
- Angiogenesis in life, disease and medicineNature, 2005
- Human peripheral blood eosinophils induce angiogenesisThe International Journal of Biochemistry & Cell Biology, 2005
- Vascular endothelial growth factor in nasal polyps: a comparison of asthmatic and non-asthmatic patientsClinical Otolaryngology, 2004
- A role for eosinophils in airway remodelling in asthmaTrends in Immunology, 2004
- Oxygen and the inflammatory cellNature, 2003
- Quantitative and morphological analysis of the vascular bed in bronchial biopsy specimens from asthmatic and non-asthmatic subjectsThorax, 2001
- Opposing Effects of Sodium Salicylate and Haematopoietic Cytokines IL-3, IL-5 and GM-CSF on Mitogen-Activated Protein Kinases and Apoptosis of EOL-1 CellsImmunological Investigations, 1999