Immuno-histochemical study of the expression of ICAM-1 in the skin of mice under the effect of exposure to ultra violet rays type-B, before and after topical Retinoic acid

Abstract

The exposure to ultraviolet radiations (UVR) become a medical problem, not just cosmetics or aesthetic concern, but for their skin photoaging and photodamage. The naturally and synthetic derivatives of vitamin A (Retinoids) may have a role in treatment and prophylaxis against skin photodamage. The current work studied the effect of ultraviolet-B rays on the ICAM-1 expression of mice's skin, before and after topical retinoids acid. Thirty-six mice were subjected to ultraviolet-B rays in dose of 1.4J/cm2 for 15minutes every other day for 10weeks. The mice were subdivided into 3 equal groups; Radiated, Prophylactic, Treated, besides the non-exposed skin samples, which considered as control group. The prophylactic mice were subjected to topical Retinoic acid one day before UVR exposure, the mice of treated groups were subjected to topical Retinoic acid after the last UVR exposure 3times weekly for 10weeks. Paraffin sections slides were prepared and stained with Hematoxylin and eosin stains for study the morphology. The immuno-histochemical study for detection of ICAM-1 expression was performed using labeled streptavidin biotin technique (Dako) with the monoclonal antibody {ICAM-1 (G- 5)}. The ICAM-1 expression was evaluated as optical density, and the obtained data was statistically analyzed by using student's t-test. The study revealed a clinical signs of photodamaged skin only in radiated group mice. Histologically epidermal thickness associated with keratinocytic atypia, and necrotic cells were observed in radiated group mice. There was a statistically significant increase in the optical density of ICAM-1 expression in radiated and prophylactic groups mice (p<0.001 and p< 0.005 respectively).. The study concluded that retinoic acid given after UVB completely reversed the morphological, histological and ICAM-1 expression changes induced by UVB exposure and retinoic acid given before UVB prevented some of the morphological, histological and ICAM-1 expression changes induced by UVB exposure.