Children's Health Research Institute, The University of Western Ontario, London, Ontario, Canada.
J Proteome Res. 2011 Apr 1;10(4):1495-504. doi: 10.1021/pr100879z. Epub 2011 Mar 10.
Placental vascular malformations result in fetal hypoxia, a serious pregnancy complication. Recent studies have linked liver-secreted and hemostatic proteins with angiogenesis. We therefore evaluated liver protein secretion changes following hypoxia, and their effect on angiogenesis, to identify potential angiogenic protein changes in the plasma of hypoxic newborns. Human vascular endothelial cells exhibited 10-fold increased tube formation with secretions from HepG2 cells cultured in 1% O(2) and 3-fold in 4% O(2) (p < 0.0001, p < 0.05) compared to 20% O(2). 2-DGE profiling of the secretions revealed significant density changes (p < 0.05) in spots identified as angiogenic proteins by LC-MS/MS. Clusterin decreased (-1.6-fold), whereas two spots of plasminogen activator inhibitor-1 (PAI-1) (2.4, and 3.6-fold), and three spots of transferrin (1.3, 1.5, and 2.6-fold) increased with 1% O(2). The levels of these proteins, subsequently determined in fetal plasma by immunoassays, strongly correlate with the fetal blood oxygen level at birth; PAI-1 and transferrin increase with low venous pO(2) (r = -0.70, p = 0.02, and r = -0.66, p = 0.04), clusterin and fibrinogen decrease (r = 0.82, p = 0.002, and r = 0.70, p = 0.02). These findings demonstrate that low oxygen levels in utero lead to pro-angiogenic changes in liver secreted plasma proteins. The pro-vascular plasma environment in hypoxic pregnancies may be acting to mitigate the compromised vasculature.
胎盘血管畸形导致胎儿缺氧，这是一种严重的妊娠并发症。最近的研究将肝脏分泌的和止血的蛋白与血管生成联系起来。因此，我们评估了缺氧后肝脏蛋白分泌的变化及其对血管生成的影响，以确定缺氧新生儿血浆中潜在的血管生成蛋白变化。与 20% O(2)相比，在 1% O(2)和 4% O(2)下培养的 HepG2 细胞的分泌液可使人类血管内皮细胞的管腔形成增加 10 倍，增加 3 倍（p < 0.0001，p < 0.05）。分泌液的 2-DGE 分析显示，通过 LC-MS/MS 鉴定为血管生成蛋白的斑点密度发生了显著变化（p < 0.05）。与 20% O(2)相比，clusterrin 减少了（-1.6 倍），而纤溶酶原激活物抑制剂-1（PAI-1）的两个斑点（2.4 和 3.6 倍）和转铁蛋白的三个斑点（1.3、1.5 和 2.6 倍）增加了 1% O(2)。随后通过免疫测定法在胎儿血浆中测定这些蛋白质的水平，与出生时胎儿血液中的氧气水平强烈相关；PAI-1 和转铁蛋白随着静脉 pO(2)的降低而增加（r = -0.70，p = 0.02 和 r = -0.66，p = 0.04），clusterrin 和纤维蛋白原减少（r = 0.82，p = 0.002 和 r = 0.70，p = 0.02）。这些发现表明，子宫内的低氧水平导致肝脏分泌的血浆蛋白发生促血管生成变化。缺氧妊娠中促血管的血浆环境可能有助于缓解血管损伤。
