Skin damage induced by UVB radiation. Analysis of an in vitro model

DANIEL H. GONZÁLEZ MAGLIO; MARIELA L. PAZ; JUANITA BUSTAMANTE; JULIANA LEONI

San Carlos de Bariloche, Argentina

Congreso; XXXIX Congreso de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB). XXXII Congreso de la Sociedad Argentina de Biofísica (SAB); 2003

The ultraviolet irradiation is divided in A, B and C, being the UVB the most harmful for health. This radiation is involved in the development of non melanoma skin cancer and in the cutaneous photosensitivity processes showed by patients suffering from autoimmune diseases, like Systemic Lupus Erythematosus. Failures in cell cycle control, as well as programmed cell death disturbances, could mediate tumor development. In the cutaneous photosensitivity process there are certain autoantigens involved, like Ro/SS-A 52 and 60; these are nuclear antigens, which are relocated towards the cell membrane after UVB light exposure and, once relocated, they could be recognized by circulating autoantibodies. Keratinocytes are the cells which are more exposed to natural UVB radiation, this is the reason why we have chosen HaCat cells (human keratinocytes cell line) for the development of the present work. The cells were irradiated with variable doses of UVB light and the apoptosis morphology was evaluated by fluorescent microscopy. The cells were irradiated with 50 mJ/cm2 developed almost 100% of apoptosis within 24 hours after irradiation. In addition to the morphology analysis we will evaluate, by Western Blot, the expression of different proteins involved in the apoptotic pathways, like p53, caspases, Bax and bcl-2 and the autoantigens Ro/SS-A 52 and 60.