Vaughan John E, Walsh Scott W
Department of Obstetrics and Gynecology, Virginia Commonwealth University Medical Center, Richmond, VA 23298-0034, USA.
Hypertens Pregnancy. 2012;31(2):243-51. doi: 10.3109/10641955.2011.642436. Epub 2012 Mar 1.
Placentas are oxidatively stressed during preeclampsia and produce more tumor necrosis factor α (TNFα) and more thromboxane than normal. Oxidative stress may cause these abnormalities by activating nuclear factor-κB (NF-κB). We measured the levels of activated NF-κB in normal and preeclamptic placentas and determined whether oxidative stress activates NF-κB in a trophoblast-like cell line.
We used immunohistochemistry to determine the percentage of the total tissue area that stained for the p65 subunit of NF-κB in placentas obtained from normal and preeclamptic pregnancies. In a second set of experiments, we used a reporter plasmid bearing the NF-κB binding site and transfected it into trophoblast-like cells. The cells were incubated with medium control, linoleic acid (LA), an oxidizing solution (Ox), or Ox enriched with LA (OxLA), TNFα, or OxLA plus TNFα for 20 h. Cell lysates were analyzed using a dual luciferase assay kit.
Placentas obtained from women with preeclampsia showed nearly a 10-fold increase in the extent of area stained for activated NF-κB as compared to normal placentas. In cell culture experiments, Ox and OxLA induced a threefold increase in NF-κB activation as compared to medium control or LA. TNFα induced a threefold increase in NF-κB activation. The combination of TNFα with OxLA caused a 10-fold increase in NF-κB activation.
Placental NF-κB is activated nearly 10-fold in preeclampsia. Oxidative stress causes NF-κB activation in a trophoblast-like cell line, which is enhanced by TNFα. These data suggest that oxidative stress is likely an important in vivo activator of placental NF-κB in preeclampsia.
子痫前期时胎盘存在氧化应激，且与正常胎盘相比，会产生更多的肿瘤坏死因子α（TNFα）和血栓素。氧化应激可能通过激活核因子-κB（NF-κB）导致这些异常情况。我们测量了正常胎盘和子痫前期胎盘组织中活化NF-κB的水平，并确定氧化应激是否能在滋养层样细胞系中激活NF-κB。
我们采用免疫组化法测定从正常妊娠和子痫前期妊娠获取的胎盘中，NF-κB p65亚基染色的组织总面积百分比。在另一组实验中，我们使用携带NF-κB结合位点的报告质粒，并将其转染至滋养层样细胞中。将细胞与培养基对照、亚油酸（LA）、氧化溶液（Ox）、富含LA的氧化溶液（OxLA）、TNFα或OxLA加TNFα一起孵育20小时。使用双荧光素酶检测试剂盒分析细胞裂解物。
与正常胎盘相比，子痫前期孕妇的胎盘组织中，活化NF-κB染色面积增加了近10倍。在细胞培养实验中，与培养基对照或LA相比，Ox和OxLA诱导NF-κB活化增加了3倍。TNFα诱导NF-κB活化增加了3倍。TNFα与OxLA联合使用导致NF-κB活化增加了10倍。
子痫前期时胎盘NF-κB的活化程度增加了近10倍。氧化应激可导致滋养层样细胞系中的NF-κB活化，TNFα可增强这种活化作用。这些数据表明，氧化应激可能是子痫前期胎盘NF-κB在体内的重要激活因子。
