Transforming growth factor-beta1 and ultraviolet A1 radiation increase production of vascular endothelial growth factor but not endothelin-1 in human dermal fibroblasts

Abstract

Background Normal and dysregulated wound healing involves fibroblast activation and angiogenesis, in which polypeptide factors such as transforming growth factor (TGF)-b, vascular endothelial growth factor (VEGF) and endothelin-1 (ET-1) play an important part. Ultraviolet (UV) A1 (365 nm) has recently received attention as a possible treatment for some dermal fibrotic disorders.Objectives The aim of this study was to evaluate the effects of TGF-b1 and UVA1 radiation, as well as that of cobalt chloride, reported to mimic hypoxia both in vivo and in vitro, on the expression of VEGF and ET-1 by cultured human dermal fibroblasts. Methods Levels of VEGF and ET-1 were measured by enzyme-linked immunosorbent assay and expression of neutral endopeptidase (NEP, CD10), known to degrade ET-1, was quantified by flow cytometric analysis after cell trypsinization.Results Our results showed that the cells released minor amounts of VEGF and ET-1. Both TGF-b1 and UVA1 strongly increased VEGF secretion in a dose-and time-dependent manner, without significantly affecting ET-1 release. Irradiation of TGF-b1-stimulated fibroblasts resulted in a synergistic effect on increasing levels of VEGF but not ET-1 after 48 h. Cobalt chloride stimulated the secretion of VEGF by fibroblasts; the effects of TGF-b1 and cobalt were additive. However, no significant effect of cobalt chloride on ET-1 secretion was observed, suggesting that ET-1 production in fibroblasts is not oxygen-sensitive. The expression of NEP was not modified by TGF-b1 or UVA1 radiation. Addition of a neutralizing anti-CD10 antibody to fibroblast cultures downregulated CD10 expression at the cell surface without changing ET-1 levels in cell supernatants after 24 or 48 h. This suggests that membrane-bound NEP has minimal or no activity against secreted ET-1. Conclusions Taken together, these results underline the major role played by TGF-b1 in increasing VEGF secretion by fibroblasts. This, as well as the documented effect of UVA1 on increasing VEGF production, may have implications for wound healing in vivo.

Ultraviolet-A radiation induces changes in cyclin G gene expression in mouse melanoma B16-F1 cells

“…The expression of vascular endothelial growth factor (VEGF) gene was upregulated in a statistically significant manner in this study, what is consistent with previously published observations, where UVA was shown to induce VEGF in dermal fibroblasts [19] and keratinocyte-derived cell lines [20]. This result suggests that UVA might affect melanoma tumor angiogenesis, via enhanced VEGF expression, and this hypothesis will be studied further in a separate project.…”

Transforming growth factor-β signaling: emerging stem cell target in metastatic breast cancer?

“…In contrast to MDA-MB-231 cells that rely on PTHrP, the bone tropism of ER-positive MCF7, ZR75-1 and T47D cells appeared to be dependent on endothelin-1 ( EDN1 ) [115, 116]. Interestingly, EDN1 gene expression is also strongly induced by TGFβ [67, 117, 118]. Thus, one might speculate that T47D bone metastases may be driven by release of TGFβ from bone matrix followed by induction of endothelin-1 in a stromal cell population, which in turn, stimulates osteoblast activity.…”

Enhancement of tumor invasion depends on transdifferentiation of skin fibroblasts mediated by reactive oxygen species

“…TGF␤1 was shown earlier to be a potent inducer of IL-6 mRNA and protein in primary human lung fibroblasts (Eickelberg et al, 1999) and of VEGF in human dermal fibroblasts (Trompezinski et al, 2000). Furthermore, tumorderived TGF␤1 induced a myofibroblast-like phenotype of primary oral fibroblasts, which, in turn, secreted significantly higher levels of HGF (Lewis et al, 2004).…”