Senescent Cells in Skin Contribute to the Formation of Age Spots, and Can be Destroyed by Radiofrequency Treatment

In this study, we reveal what we believe is a novel mechanism whereby aged fibroblasts contribute to the local regulation of melanogenesis. We show that as an individual ages, pigmented skin contains an increasing proportion of senescent fibroblasts. Phenotype switching in these cells results in the loss of SDF1, and SDF1 deficiency appears to be a potent stimulus for the melanogenic processes that contribute to uneven pigmentation. These changes might be epigenetic. For example, the level of hypermethylation of the SDF1 promoter was remarkably different between hyperpigmented and perilesional skin. The human skin, unlike other organs, undergoes photo-ageing in addition to natural ageing processes, and photo-ageing has been attributed to ageing pigmentation. Both processes are cumulative, and the most noticeable age-related changes therefore occur in the superficial layer of the skin. In the present study, we show that cellular senescence is especially likely to occur in fibroblasts located in the upper dermis of pigmented skin. Senescent fibroblasts are expected to influence melanocytes via cross-talk that can readily occur through a damaged basement membrane. We showed that senescent fibroblasts play a stimulatory role in pigmentation by upregulating the expression of the melanogenesis regulators MITF and tyrosinase in melanocytes. Moreover, the impact of senescent fibroblasts on skin pigmentation was directly demonstrated when eliminating senescent cells wit...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs