Expression of VEGFR-2 on HaCaT cells is regulated by VEGF and plays an active role in mediating VEGF induced effects.
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.
Yang
Xiao-Hong
XH
Department of Dermatology, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, China.
Man
Xiao-Yong
XY
Cai
Sui-Qing
SQ
Yao
Yong-Gang
YG
Bu
Zhang-Yu
ZY
Zheng
Min
M
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*
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