Comparative expression of PEDF and VEGF in human epidermal keratinocytes and dermal fibroblasts: from normal skin to psoriasis.

Vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF) have been shown to keep angiogenesis activation and inhibition in balance in normal and pathological conditions. In this study, we examined the expression of VEGF and PEDF in keratinocytes and fibroblasts from normal and psoriatic skin to evaluate their potential roles and interactions in the development of psoriasis. The expression of VEGF and PEDF was detected in normal and psoriatic skin ex vivo and in co-cultured keratinocytes and fibroblasts in vitro, and increased in keratinocytes and fibroblasts from psoriatic skin compared with those cells from normal skin. Our results suggest that PEDF act as a multipotent factor in the skin and the imbalance of PEDF and VEGF may be responsible for the transformation from normal skin to psoriasis.