Ahmed A, Li X F, Dunk C, Whittle M J, Rushton D I, Rollason T
Centre for Clinical Research in Immunology and Signalling, Medical School, University of Birmingham, Edgbaston, UK.
Growth Factors. 1995;12(3):235-43. doi: 10.3109/08977199509036883.
Vascular endothelial growth factor (VEGF) is an angiogenic protein which acts on both endothelial and trophoblast cells. In first trimester placenta, VEGF immunoreactive protein was detected in cytotrophoblast shell suggesting a role in the regulation of cytotrophoblast growth and differentiation as they also expressed VEGF receptor (flt-1) protein. VEGF and flt-1 immunoreactive proteins were expressed in Hofbauer cells within the villous mesenchyme, macrophages and in maternal decidual cells while weak VEGF immunoreactive protein was seen in syncytiotrophoblast surrounding the placental villi in first and second trimester placentae. At term, there was relatively weak VEGF and flt-1 immunostaining in the syncytiotrophoblast while intense VEGF immunostaining was seen in the Hofbauer and maternal decidual cells. Extravillous trophoblast showed immunostaining for flt-1 but no staining for VEGF. Both amnion and chorion expressed strong VEGF immunoreactivity throughout gestation. Smooth muscle cells surrounding the vein and arteries of the umbilical cord showed weak VEGF immunoreactivity while no immunoreactivity was localised in endothelial cells. VEGF stimulated parathyroid hormone-related protein (PTHrP) release (mean (+/- SD): basal, 0.96 +/- 0.03; 10 ng/ml VEGF165, 2.07 +/- 0.18 and 20 ng/ml VEGF165, 2.43 +/- 0.18 pmol/l/well of PTHrP1-86) in condition medium from immortalised first trimester trophoblast cell line. These results suggest that VEGF in addition to acting as an autocrine mitogen for trophoblast proliferation may also function as a paracrine mediator of vascular tone by releasing vasorelaxants from trophoblasts.
血管内皮生长因子（VEGF）是一种血管生成蛋白，作用于内皮细胞和滋养层细胞。在孕早期胎盘的细胞滋养层壳中检测到VEGF免疫反应蛋白，这表明其在调节细胞滋养层生长和分化中发挥作用，因为它们也表达VEGF受体（flt-1）蛋白。VEGF和flt-1免疫反应蛋白在绒毛间充质中的霍夫鲍尔细胞、巨噬细胞以及母体蜕膜细胞中表达，而在孕早期和孕中期胎盘绒毛周围的合体滋养层中可见较弱的VEGF免疫反应蛋白。足月时，合体滋养层中的VEGF和flt-1免疫染色相对较弱，而在霍夫鲍尔细胞和母体蜕膜细胞中可见强烈的VEGF免疫染色。绒毛外滋养层显示flt-1免疫染色，但无VEGF染色。羊膜和绒毛膜在整个妊娠期均表达强烈的VEGF免疫反应性。脐带静脉和动脉周围的平滑肌细胞显示较弱的VEGF免疫反应性，而在内皮细胞中未检测到免疫反应性。VEGF刺激来自永生化孕早期滋养层细胞系的条件培养基中甲状旁腺激素相关蛋白（PTHrP）的释放（平均值（±标准差）：基础值，0.96±0.03；10 ng/ml VEGF165，2.07±0.18；20 ng/ml VEGF165，2.43±0.18 pmol/l/孔PTHrP1-86）。这些结果表明，VEGF除了作为滋养层增殖的自分泌有丝分裂原外，还可能通过从滋养层释放血管舒张剂而作为血管张力的旁分泌介质发挥作用。
