title: Expression of VEGFR-2 on HaCaT cells is regulated by VEGF and plays an active role in mediating VEGF induced effects.
abstract: Vascular endothelial growth factor (VEGF) and its receptor VEGFR-2 play important roles in mitogenesis and chemotaxis of endothelial cells. In normal human skin, VEGF is expressed and secreted by epidermal keratinocytes. Emerging data suggest that keratinocyte-derived VEGF targets other cell types besides the dermal endothelial cells. We have recently showed that keratinocytes from human normal skin expressed all five known VEGF receptors and co-receptors (neuropilin 1 and 2). To define the functional significance of VEGFR-2 in epidermis, we examined its role in a keratinocyte cell line, HaCaT cells, in response to VEGF treatment. Expression of VEGFR-2 on HaCaT cells was confirmed at both RNA and protein levels and was regulated by VEGF165 treatment. Treatment of HaCaT cells with VEGF165 induced tyrosine-autophosphorylation of VEGFR-2 and phosphorylation of PLC-gamma and p44/42 MAPK in a time-dependent manner. Preincubation with a neutralizing antibody for VEGFR-2 (MAB3571) completely abrogated these phosphorylation effects. Furthermore, VEGF165 stimulated proliferation and migration of HaCaT cells, and this effect was significantly blocked by a pretreatment with MAB3571. Neutralizing VEGFR-2 in HaCaT cells increased cell adhesion during culture. Our results suggest that VEGFR-2 expressed on HaCaT cells plays a crucial role in VEGF-mediated regulation of cell activity.
authors.affiliation: Department of Dermatology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, China.
authors.forename: Xiao-Hong
authors.initials: XH
authors.lastname: Yang
authors.forename: Xiao-Yong
authors.initials: XY
authors.lastname: Man
authors.forename: Sui-Qing
authors.initials: SQ
authors.lastname: Cai
authors.forename: Yong-Gang
authors.initials: YG
authors.lastname: Yao
authors.forename: Zhang-Yu
authors.initials: ZY
authors.lastname: Bu
authors.forename: Min
authors.initials: M
authors.lastname: Zheng
mesh_terms: D002448:Cell Adhesion; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D015603:Keratinocytes / Q000378:metabolism; D039942:Neuropilin-1 / Q000378:metabolism; D039943:Neuropilin-2 / Q000378:metabolism; D051966:Phospholipase C gamma / Q000378:metabolism; D010766:Phosphorylation; D012313:RNA / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism / Q000502:physiology*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000096:biosynthesis*
chemical_list: D039943:Neuropilin-2; D042461:Vascular Endothelial Growth Factor A; D039942:Neuropilin-1; D012313:RNA; D040301:Vascular Endothelial Growth Factor Receptor-2; D051966:Phospholipase C gamma