P53 Expression in the Lens After Ultraviolet Radiation (UVR) Exposure

Abstract

Abstract: : Purpose: The tumor–suppressor gene p53 encodes a phosphoprotein involved in the control of cell growth. Its expression and function have been documented in malignancy, apoptosis, and other abnormal cell proliferation processes. Apoptosis due to UVR is a well–described process in the lens. Recently, expression of p53 has been demonstrated in the normal murine eye. P53 is a well–known studied gene in skin and melanoma. The purpose of this study was to localize p53 in the albino rat lens and to study if p53 expression increases or decreases due to UVR exposure. Methods: altogether 10 Sprague–Dawley albino rats were unilaterally exposed to UVR meanwhile the other eye was used as control. 1 week after exposure the rats were sacrificed, lenses were extracted, 8 lenses (4 exposed and 4 no exposed) were analysed by immunohistochemistry to localize p53 and 12 lenses (6 exposed and 6 no exposed) were analysed by real–time PCR to estimate p53 expression. Results: All lenses exposed to UVR showed cataract. Immunohistochemistry localized p53 in the lens epithelial cells. Real–time PCR showed that p53 expression was significant higher (150%) in lenses exposed to UVR than in no exposed lenses. Conclusions: Apoptosis in the lens due to UVR exposure seems to be mediated through p53 increased expression.

Keywords: gene/expression • cataract • radiation damage: light/UV