Abstract
Abstract: :
Purpose: The role of proinflammatory chemokines and cytokines has received much interest in the pathogenesis of photokeratitis and UV related ocular diseases. In this study we examined the effects of UVB on human corneal epithelial cell (HCE-T) epithelial growth factor receptor (EGFR) phosphorylation, NF-ΚB activation, and subsequent proinflammatory cytokine production. Methods: HCE-T cells were irradiated with UVB (0-100mJ/cm2) and cultured in KGM media for varying amounts of time post irradiation. EGFR phosphorylation was measured by Western Blot analysis and ELISA 20 minutes after UVB irradiation. NF-ΚB activation was determined by immunofluorescent nuclear localization using an anti-human NF-ΚB monoclonal antibody and a fluorescein conjugated IgG antibody 30 minutes post UVB. Cytokine production was measured by quantitative RT-PCR and ELISA 1, 3, 12 and 24 hours after irradiation. PMA-treated cells served as a positive control for these studies. Results: Our results demonstrated that EGFR was rapidly phosphorylated after UVB exposure in HCE-T. This was followed by the rapid nuclear translocation of NF-ΚB and finally the production of high levels of IL-1, IL-6, IL-8, and TNFα were observed several hours post irradiation. Conclusion: These results demonstrate that acute ultraviolet exposure induces the rapid activation of HCE-T EGFR phosphorylation and NF-ΚB nuclear translocation which results in the production of various proinflammatory chemokines and cytokines. Understanding the corneal inflammatory mechanisms induced by UVB may lead to new therapeutic approaches to UV related ocular diseases.
Keywords: 372 cornea: epithelium • 437 inflammation • 515 phosphorylation