Comparison of the effect of fibroblasts from fetal versus adult origin on reconstructed skin pigmentation.

<p>PRS samples were reconstructed with either fetal fibroblasts (GM10) or adult (21 yr-old donor) fibroblasts within the dermal equivalent. Identical keratinocyte and melanocyte strains were used for the epidermal reconstruction. A drastic increase in pigmentation of the PRS and activation of melanocytes in the presence of fetal fibroblasts as compared to adult fibroblasts, were noted A<b>)</b> macroscopically (Macro), on histological sections stained with Fontana-Masson (FM) and by tyrosinase staining (Tyr) of tissue sections. The hyper-pigmentation observed in fetal versus adult fibroblast condition was quantified by <b>B</b>) a decrease in Luminance value and <b>C</b>) an increase in melanin content. TRP-1 labeling of tissue sections showed that melanocytes were correctly located at the basal layer in both conditions (<b>A</b>). TRP-1 staining of epidermal sheets revealed an increase in melanocyte numbers in the presence of fetal fibroblasts (<b>A</b>) which was confirmed by image analysis (<b>D</b>). CD13 staining revealed no change in fibroblast morphology or density (<b>A</b>). Values are expressed as the mean +/- SD calculated for 4 different samples in 2 independent experiments and analyzed using the two-tailed unpaired Student's t-test, *** p<0.001. Magnifications (<b>A</b>): FM, TYR, and TRP-1/section = x400, CD13/section = x200, TRP1/sheet = x50.