Conflicts of interest None declared.
Role of fibroblast-derived growth factors in regulating hyperpigmentation of solar lentigo
Version of Record online: 19 JUL 2010
© 2010 The Authors. BJD © 2010 British Association of Dermatologists
British Journal of Dermatology
Volume 163, Issue 5, pages 1020–1027, November 2010
How to Cite
Kovacs, D., Cardinali, G., Aspite, N., Cota, C., Luzi, F., Bellei, B., Briganti, S., Amantea, A., Torrisi, M.R. and Picardo, M. (2010), Role of fibroblast-derived growth factors in regulating hyperpigmentation of solar lentigo. British Journal of Dermatology, 163: 1020–1027. doi: 10.1111/j.1365-2133.2010.09946.x
The first two authors contributed equally to this work.
- Issue online: 26 OCT 2010
- Version of Record online: 19 JUL 2010
- Accepted for publication 1 July 2010
- melanogenic growth factors;
- solar lentigo
Background Cutaneous pigmentation is regulated by a complex melanogenic network in which both keratinocytes and fibroblasts synthesize growth factors and cytokines. Solar lentigo (SL) is characterized by hyperpigmented lesions occurring on photodamaged skin areas. Despite the association of SL to ultraviolet (UV) exposure, the mechanisms underlying the development of these spots are not completely defined.
Objectives To analyse the involvement of the fibroblast-derived growth factors, hepatocyte growth factor (HGF), keratinocyte growth factor (KGF) and stem cell factor (SCF) in SL hyperpigmentation; to evaluate whether the photoageing process occurring in fibroblasts could be responsible for the altered expression of these cytokines; and to investigate a new possible role of KGF in regulating pigmentation through the specific induction of melanogenic cytokines by keratinocytes.
Methods We performed immunohistochemical analysis of HGF, KGF and SCF on SL biopsies. We analysed the mRNA expression of these cytokines using an in vitro model of photoageing induced on fibroblasts. Finally, we evaluated the effects of KGF on the expression of melanogenic cytokines at the mRNA and protein levels on keratinocytes.
Results We found positive staining for HGF, KGF and SCF in the upper dermis of SL lesions and a significant induction of the three cytokines in photoaged fibroblasts. We also demonstrated the contribution of KGF to pigmentation, showing its ability specifically to modulate the expression of SCF in keratinocytes.
Conclusions Fibroblasts may be persistently activated by UV exposure to release melanogenic growth factors; this inducible cytokine network acts both directly and indirectly through keratinocytes and may contribute to the hyperpigmentation of SL.