Effects of vitamin D-induced supernatant of placental explants from preeclamptic women on oxidative stress and nitric oxide bioavailability in human umbilical vein endothelial cells

The study evaluated the effect of the supernatant of placental explants from preeclamptic (PE) and normotensive (NT) pregnant women after tissue treatment with or without vitamin D (VD) on oxidative stress and nitric oxide (NO) bioavailability in human umbilical vein endothelial cells (HUVEC). Placental explants were prepared from eight NT and eight PE women, and supernatants were obtained after incubation with or without hydrogen peroxide (H2O2) and/or VD. HUVEC were cultured for 24 h with supernatants, and the following parameters were analyzed in HUVEC cultures: NO, nitrate (NO3-), and nitrite (NO2-) levels, lipid peroxidation, and intracellular reactive oxygen species (ROS). Results showed that the production of NO3-, NO2-, malondialdehyde (MDA), and ROS were significantly higher in HUVEC treated with explant supernatant from PE compared to NT pregnant women, while the supernatant of PE explants treated with VD led to a decrease in these parameters. A significantly high production of NO was detected in HUVEC cultured with control supernatant of NT group, and in cultures treated with supernatant of PE explants treated with VD. Taken together, these results demonstrated that cultures of placental explants from PE women with VD treatment generated a supernatant that decreased oxidative stress and increased the bioavailability of NO in endothelial cells.

本研究评估了子痫前期（preeclamptic, PE）与血压正常（normotensive, NT）孕妇的胎盘外植体经维生素D（VD）或不经维生素D处理后的上清液，对人脐静脉内皮细胞（human umbilical vein endothelial cells, HUVEC）内氧化应激与一氧化氮（NO）生物利用度的影响。研究从8名NT孕妇与8名PE孕妇体内分离制备胎盘外植体，在添加或不添加过氧化氢（hydrogen peroxide, H2O2）和/或VD的条件下进行孵育，随后获取各组上清液。将HUVEC与上述上清液共培养24小时后，对HUVEC培养物中的以下指标进行检测：NO、硝酸盐（nitrate, NO3-）、亚硝酸盐（nitrite, NO2-）水平，脂质过氧化程度以及细胞内活性氧（reactive oxygen species, ROS）水平。结果表明，相较于血压正常孕妇来源的胎盘外植体上清液处理组，PE组来源的上清液处理组HUVEC内NO3-、NO2-、丙二醛（malondialdehyde, MDA）与ROS的生成量显著升高；而经VD预处理的PE组胎盘外植体上清液可显著降低上述指标的水平。此外，在NT组对照上清液培养的HUVEC以及经VD处理的PE组外植体上清液处理的HUVEC中，均检测到显著升高的NO生成量。综合上述实验结果，本研究证实经VD处理的PE孕妇胎盘外植体所分泌的上清液，可降低内皮细胞内的氧化应激水平并提升一氧化氮的生物利用度。