Mehta Vedanta, Abi-Nader Khalil N, Shangaris Panicos, Shaw S W Steven, Filippi Elisa, Benjamin Elizabeth, Boyd Michael, Peebles Donald M, Martin John, Zachary Ian, David Anna L
Institute for Women's Health, UCL, London, United Kingdom; Centre for Cardiovascular Biology and Medicine, Division of Medicine, Rayne Building, UCL, London, United Kingdom.
Institute for Women's Health, UCL, London, United Kingdom.
PLoS One. 2014 Jun 30;9(6):e100021. doi: 10.1371/journal.pone.0100021. eCollection 2014.
The normal development of the uteroplacental circulation in pregnancy depends on angiogenic and vasodilatory factors such as vascular endothelial growth factor (VEGF). Reduced uterine artery blood flow (UABF) is a common cause of fetal growth restriction; abnormalities in angiogenic factors are implicated. Previously we showed that adenovirus (Ad)-mediated VEGF-A165 expression in the pregnant sheep uterine artery (UtA) increased nitric oxide synthase (NOS) expression, altered vascular reactivity and increased UABF. VEGF-D is a VEGF family member that promotes angiogenesis and vasodilatation but, in contrast to VEGF-A, does not increase vascular permeability. Here we examined the effect of Ad.VEGF-DΔNΔC vector encoding a fully processed form of VEGF-D, on the uteroplacental circulation.
UtA transit-time flow probes and carotid artery catheters were implanted in mid-gestation pregnant sheep (n = 5) to measure baseline UABF and maternal haemodynamics respectively. 7-14 days later, after injection of Ad.VEGF-DΔNΔC vector (5×10(11) particles) into one UtA and an Ad vector encoding β-galactosidase (Ad.LacZ) contralaterally, UABF was measured daily until scheduled post-mortem examination at term. UtAs were assessed for vascular reactivity, NOS expression and endothelial cell proliferation; NOS expression was studied in ex vivo transduced UtA endothelial cells (UAECs).
At 4 weeks post-injection, Ad.VEGF-DΔNΔC treated UtAs showed significantly lesser vasoconstriction (Emax144.0 v/s 184.2, p = 0.002). There was a tendency to higher UABF in Ad.VEGF-DΔNΔC compared to Ad.LacZ transduced UtAs (50.58% v/s 26.94%, p = 0.152). There was no significant effect on maternal haemodynamics. An increased number of proliferating endothelial cells and adventitial blood vessels were observed in immunohistochemistry. Ad.VEGF-DΔNΔC expression in cultured UAECs upregulated eNOS and iNOS expression.
Local over-expression of VEGF-DΔNΔC in the UtAs of pregnant mid-gestation sheep reduced vasoconstriction, promoted endothelial cell proliferation and showed a trend towards increased UABF. Studies in cultured UAECs indicate that VEGF-DΔNΔC may act in part through upregulation of eNOS and iNOS.
孕期子宫胎盘循环的正常发育依赖于血管生成和血管舒张因子，如血管内皮生长因子（VEGF）。子宫动脉血流减少（UABF）是胎儿生长受限的常见原因；血管生成因子异常与之相关。此前我们发现，腺病毒（Ad）介导的VEGF-A165在妊娠绵羊子宫动脉（UtA）中的表达可增加一氧化氮合酶（NOS）表达，改变血管反应性并增加UABF。VEGF-D是VEGF家族成员，可促进血管生成和血管舒张，但与VEGF-A不同的是，它不会增加血管通透性。在此，我们研究了编码完全加工形式VEGF-D的Ad.VEGF-DΔNΔC载体对子宫胎盘循环的影响。
在妊娠中期的绵羊（n = 5）体内植入UtA渡越时间血流探头和颈动脉导管，分别测量基线UABF和母体血流动力学。7 - 14天后，向一侧UtA注射Ad.VEGF-DΔNΔC载体（5×10¹¹颗粒），对侧注射编码β-半乳糖苷酶的Ad载体（Ad.LacZ），每天测量UABF，直至足月时进行预定的尸检。评估UtA的血管反应性、NOS表达和内皮细胞增殖；在体外转导的UtA内皮细胞（UAECs）中研究NOS表达。
注射后4周，Ad.VEGF-DΔNΔC处理的UtA显示出明显较小的血管收缩（Emax 144.0对184.2，p = 0.002）。与Ad.LacZ转导的UtA相比，Ad.VEGF-DΔNΔC处理的UtA有UABF升高的趋势（50.58%对26.94%，p = 0.152）。对母体血流动力学无显著影响。免疫组化观察到增殖的内皮细胞和外膜血管数量增加。培养的UAECs中Ad.VEGF-DΔNΔC的表达上调了eNOS和iNOS的表达。
妊娠中期绵羊UtA中VEGF-DΔNΔC的局部过表达减少了血管收缩，促进了内皮细胞增殖，并显示出UABF增加的趋势。在培养的UAECs中的研究表明，VEGF-DΔNΔC可能部分通过上调eNOS和iNOS起作用。
