The placenta growth factor in skin angiogenesis.

The placenta growth factor (PlGF) is a member of the vascular endothelial growth factor (VEGF) family that has been shown to play an important role in promoting adult pathological angiogenesis. Besides inducing its own signaling in endothelial cells, PlGF exerts its angiogenic action by synergising with VEGF. In the skin, PlGF expression is upregulated during wound healing and PlGF-deficient mice show delayed wound closure, indicating that this factor promotes angiogenesis during skin repair. Moreover, PlGF expression by melanoma cells has been linked to tumor growth. The analysis of a transgenic mouse model constitutively expressing high levels of PlGF in basal keratinocytes has shown that this factor has strong angiogenic properties in the skin during both embryonic and post-natal life. Furthermore, PlGF delivery to the skin via an adenoviral vector induces the formation of large and stable blood vessels, but contrary to VEGF application, does not affect lymphatic vessel functionality. Such evidence opens the possibility of employing PlGF for therapeutic modulation of skin angiogenesis.