Department of Dermatology, Second Affiliated Hospital, Zhejiang University School of Medicine, 88 Jiefang Road, Hangzhou 310009, Zhejiang, China.
Mol Biol Rep. 2012 Sep;39(9):8687-94. doi: 10.1007/s11033-012-1725-6. Epub 2012 Jun 16.
Vascular endothelial growth factor (VEGF) is a key regulator of physiological and pathological angiogenesis. The biological effects of VEGF are mediated by receptor tyrosine kinases. VEGF receptor-2, the primary receptor for VEGF, is thought to mediate most functional effects. In this study, we examined the expression and roles of VEGF receptor-2 on human outer root sheath cells (ORS). The expression of VEGFR-2 was determined at mRNA and protein levels by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. Localization of VEGFR-2 in ORS cells was detected by immunofluorescence. The effect of VEGF on ORS cell proliferation was determined by MTT assays. Our data showed the expression of VEGFR-2 on ORS cells at both mRNA and protein levels. Immunostaining for VEGFR-2 demonstrated strong signal on cultured ORS cells. Exogenous VEGF(165) stimulated proliferation of ORS cells and upregulated expression of VEGFR-2 in a dose-dependent manner. Moreover, VEGF(165) induced phosphorylation of VEGFR-2, PLC-γ1, PKC-α, MEK, and p44/42 MAPK (ERK1/2) in a time-dependent manner. Taken together, human ORS cells express functional VEGF receptor-2 and exogenous VEGF(165) upregulates expression of VEGFR-2 and stimulates proliferation of ORS cells via VEGFR-2 mediated ERK signaling pathway.
血管内皮生长因子（VEGF）是生理和病理血管生成的关键调节剂。VEGF 的生物学效应通过受体酪氨酸激酶介导。VEGF 受体-2 是 VEGF 的主要受体，被认为介导大多数功能效应。在这项研究中，我们研究了 VEGF 受体-2 在人毛外根鞘细胞（ORS）中的表达和作用。通过逆转录-聚合酶链反应（RT-PCR）和 Western blot 测定 VEGFR-2 在 mRNA 和蛋白质水平上的表达。通过免疫荧光检测 VEGFR-2 在 ORS 细胞中的定位。通过 MTT 测定法确定 VEGF 对 ORS 细胞增殖的影响。我们的数据显示 ORS 细胞在 mRNA 和蛋白质水平上均表达 VEGFR-2。VEGFR-2 的免疫染色在培养的 ORS 细胞上显示出强信号。外源性 VEGF(165)以剂量依赖性方式刺激 ORS 细胞增殖并上调 VEGFR-2 的表达。此外，VEGF(165)以时间依赖性方式诱导 VEGFR-2、PLC-γ1、PKC-α、MEK 和 p44/42 MAPK（ERK1/2）的磷酸化。总之，人 ORS 细胞表达功能性 VEGF 受体-2，外源性 VEGF(165)通过 VEGFR-2 介导的 ERK 信号通路上调 VEGFR-2 的表达并刺激 ORS 细胞增殖。
