Factors influencing the expression of Fas and Fas ligand on newborn murinekeratinocytes and fibroblasts

Objective To investigate the expression of Fas, Fast mRNA and proteins on k eratinocytes and fibroblasts, and the influence by retinoid acid (RA) and d examethasone (Dex). Methods RNase protection assay and flow cytometry were used. Results Fas mRNA was expressed on neonatal murine keratinocytes and was up- regulated by all-trans retinoid acid and down-regulated by Dex. RA and Dex also increased the Fas protein expression on keratinocytes. Newborn murine keratinocytes express Fast mRNA, which was up-regulated by RA and Dex, whil e its protein expression was moderately induced by RA. Newborn murine fibro blasts also expressed Fas and Fast mRNA, which were up-regulated by the RA and Dex. Conclusions The results indicated that RA and Dex might regulate apoptosis of keratinocytes and fibroblasts via the Fas-FasL system.