Age-induced and photoinduced changes in gene expression profiles in facial skin of Caucasian females across 6 decades of age

Abstract

Intrinsic and extrinsic factors, including ultraviolet irradiation, lead to visible signs of skin aging. We evaluated molecular changes occurring in photoexposed and photoprotected skin of white women 20 to 74years of age, some of whom appeared substantially younger than their chronologic age. Histologic and transcriptomics profiling were conducted on skin biopsy samples of photoexposed (face and dorsal forearm) or photoprotected (buttocks) body sites from 158 women. 23andMe genotyping determined genetic ancestry. Gene expression and ontologic analysis revealed progressive changes from the 20s to the 70s in pathways related to oxidative stress, energy metabolism, senescence, and epidermal barrier; these changes were accelerated in the 60s and 70s. The gene expression patterns from the subset of women who were younger-appearing were similar to those in women who were actually younger. Broader application of these findings (eg, across races and Fitzpatrick skin types) will require further studies. This study demonstrates a wide range of molecular processes in skin affected by aging, providing relevant targets for improving the condition of aging skin at different life stages and defining a molecular pattern of epidermal gene expression in women who appear younger than their chronologic age.