These findings suggest that in addition to the stimulated expression of the ET-1/ET(B)R cascade, the accentuated expression of SCF in lesional skin plays an important role in the mechanism involved in the epidermal hyperpigmentation of LS.
The endothelin-1-inducible cytokine, tumor necrosis factor alpha, was consistently upregulated in the lentigo senilis lesional epidermis as determined at the transcriptional level and by immunostaining, whereas interleukin-1alpha was downregulated.
In this study, we found that secreted frizzled-related protein 2 (sFRP2) is overexpressed in the hyperpigmentary skin of melasma and solar lentigo and in acutely UV-irradiated skin.
In summary, MCP-1 may participate in the development of SL by affecting epidermal constituent cells, for example, by inducing melanocyte proliferation and keratinocyte senescence.
Reverse transcriptase polymerase chain reaction analysis concomitantly demonstrated accentuated expression of transcripts for endothelin-1 and for the endothelin B receptor in lentigo senilis lesional skin, which was accompanied by a similar accentuated expression of tyrosinase mRNA compared with the perilesional control.
The endothelin-1-inducible cytokine, tumor necrosis factor alpha, was consistently upregulated in the lentigo senilis lesional epidermis as determined at the transcriptional level and by immunostaining, whereas interleukin-1alpha was downregulated.