Differential in vitro responses of elastin expression to basic fibroblast growth factor and transforming growth factor beta 1 in upper, middle and lower dermal fibroblasts.

Elastin mRNA levels were measured in cultured skin fibroblasts derived from upper, middle and lower dermal layers. The elastin mRNA levels were highest in the fibroblasts from the upper dermal layer and lowest in the lower dermal fibroblasts. Modulation of elastin expression by basic fibroblast growth factor and transforming growth factor beta 1 in the dermal fibroblasts was also studied. Basic fibroblasts growth factor downregulated elasin expression in the upper dermal fibroblasts but did not significantly change elastin expression in the middle and lower dermal fibroblasts. Upregulation of elastin expression by transforming growth factor beta 1 was greater in the upper dermal fibroblasts than in the middle and lower dermal fibroblasts. Platelet-derived growth factor induced no significant changes in the three types of dermal fibroblasts. The results suggest that the differential responses of elastin expression to potent modulators may be at least partially responsible for the abnormal elastin metabolism specifically observed in the upper dermal layer.