Senescent fibroblasts in melasma pathophysiology.

It has been proposed that melasma is a photoageing skin disorder. The photoaged fibroblasts have been suggested as an important source of melanogenic factors which are involved in the regulation of pigmentation. To investigate whether melasma includes senescent cells, lesional and perilesional normal skin from 38 melasma patients was assessed using a cell senescence marker, p16INK4A . The results showed that lesional dermal skin had more p16INK4A -positive senescent cells than perilesional skin. The impact of senescent fibroblasts was further investigated in a pilot study using radiofrequency (RF) intervention for melasma. It showed that the RF therapy decreased the number of senescent cells with increased expression of procollagen-1, which were associated with reduced epidermal pigmentation. This leads us to the speculation that senescent fibroblasts may contribute to drive melasma and might be considered as a potential therapeutic target.