1291 PPAR-γ signaling is dysregulated in keloids

Abstract

Stem cell factor (SCF) is developmentally critical for melanocyte migration, differentiation, and survival. Recently, SCF expression in hair shaft progenitor cells has been shown to be absolutely required for the pigmentation in hair shafts, as evidenced by the complete loss of hair pigmentation in mice without SCF in these epithelial cells. Interestingly, this fully disruption of hair pigmentation only targets melanogenic mature monocytes in the upper hair bulb, but not melanocyte precursors below. This shows an important role of SCF in the determination of mature melanocytes to their destination. Here we report that the skin pigmentation in the dermis layer appears to follow the same mechanism for the distribution of dermal melanocytes. We employed multiple cell-type specific Scf knockout mice to characterize the sources and contribution of SCF to dermal pigmentation. Our results show that dermal melanocytes are also sustained by SCF. However, in contrast to hair pigmentation, dermal pigmentation appears to be supported by SCF expression in a selective population of dermal cells. This study reveals a faithful distribution of melanogenic melanocytes in distinct skin compartments guided by selective populations of SCF expressing cells. Our findings suggest that manipulation of SCF expression in the skin cells might be a potential target to manage hyper-or hypo-pigmented skin manifestations in clinic.