Original Article
Insulin-Like Growth Factor-II Regulates the Expression of Vascular Endothelial Growth Factor by the Human Keratinocyte Cell Line HaCaT

https://doi.org/10.1111/j.0022-202X.2004.22735.xGet rights and content
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Psoriasis is a chronic, relapsing skin disease characterized by enhanced angiogenesis. The pathogenetic process resulting in hypervascularity remains to be further investigated. It has been reported that a potent angiogenic factor, vascular endothelial growth factor (VEGF) is overexpressed in psoriatic epidermis and that the level of insulin-like growth factor II (IGF-II) is significantly elevated in the tissue fluid and serum of the psoriatic lesion. We considered the possibility that IGF-II might function as a paracrine inducer of VEGF. Here, we demonstrated that exposure of HaCaT keratinocytes to IGF-II induced both mRNA and protein expression of VEGF through the MAP kinase (extracellular signal-regulated kinase (ERK2) pathway. Particularly, we determined that phosphorylation of ERK2 but not p38 and JNK1/2 was activated by IGF-II in a time-dependent manner. Additionally, we found that IGF-II treatment induced the expression of MDM2 through the MAP kinase pathway. Moreover, the increase of MDM2 resulted in decreased levels of p53 followed by increased expression of HIF-1α and VEGF. Taken together, these results suggest that IGF-II enhances the expression of VEGF in HaCaT cells by increasing HIF-1α levels.

Keyword

angiogenesis/HaCaT/IGF-II/VEGF

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