Evaluation of the Prognostic Value of the sFlt-1/PlGF Ratio in Early-Onset Preeclampsia.

OBJECTIVE: Increased expression of soluble fms-like tyrosine kinase 1 (sFlt-1), associated with a decrease in placental growth factor (PlGF), plays a key role in the pathogenesis of preeclampsia (PE). We evaluated the prognostic value of the sFlt-1/PlGF ratio for the onset of adverse maternofetal outcomes (AMFO) in case of early-onset PE with attempted expectant management. STUDY DESIGN: From October 2016 through November 2018, all singleton pregnancies complicated by early-onset PE (before 34 weeks of gestation) were included in a cohort study. The plasma levels of sFlt-1 and PlGF were blindly measured on admission. For the statistical analysis, we performed a bivariate analysis, a comparison of the receiving operating characteristic curves and a survival analysis estimated by the Kaplan-Meier method. RESULTS: Among 109 early PE, AMFO occurred in 87 pregnancies (79.8%), mainly hemolysis, elevated liver enzymes, and low platelet count syndrome and severe fetal heart rate abnormalities requiring urgent delivery. The area under the curve (AUC) of sFlt-1/PlGF ratio was 0.82 (95% confidence interval [CI]: 0.73-0.88) for the risk of AMFO and the difference between the AUCs was significant for each separate standard parameter (p = 0.018 for initial diastolic blood pressure, p = 0.013 for alanine aminotransferase, p < 0.001 for uric acid). Pregnancies were best classified by a cutoff ratio of 293, with a sensitivity of 95% and a specificity of 50%. With a ratio value less than 293, no pregnancy was complicated or had been stopped during the first 5 days. A ratio more than 293 was associated with an increased risk of AMFO onset (hazard ratio [HR]: 3.61; 95% CI: 2.13-6.10; p < 0.001) and had a significant association with the length of time between the diagnosis of PE and delivery (HR: 2.49; 95% CI: 1.56-3.96; p < 0.001). CONCLUSION: The sFlt-1/PlGF ratio is an additional tool in the prediction of AMFO in proven early-onset PE, which is likely to improve care by anticipating severe complications. KEY POINTS: · The sFlt-1/PlGF ratio is associated with AMFO.. · It is an additional tool for physician.. · We proposed a 293 cutoff value for the ratio..

A role for 4-hydroxy-2-nonenal in premature placental senescence in preeclampsia and intrauterine growth restriction.

Premature placental senescence is a hallmark of pregnancy-related disorders such as intrauterine growth restriction (IUGR) and preeclampsia (PE), two major cause of maternal and neonatal morbidity and mortality. Oxidative stress and lipid peroxidation are involved in the pathogenesis of PE and IUGR, and may play a role in placental aging. In this study, we investigated whether 4-hydroxy-2-nonenal (HNE), a lipid peroxidation-derived aldehyde present in preeclamptic placentas, may contribute to premature senescence in placenta-related complications. Placentas from PE-affected women, exhibited several senescence patterns, such as an increased expression of phosphorylated (serine-139) histone γH2AX, a sensitive marker of double-stranded DNA breaks, the presence of lipofuscin granules, and an accumulation of high molecular weight cross-linked and ubiquitinated proteins. PE placentas showed an accumulation of acetylated proteins consistent with the presence of HNE-adducts on sirtuin 1 (SIRT1). Likewise, oxidative stress and senescence markers together with SIRT1 modification by HNE, were observed in murine placentas from mice treated with lipopolysaccharide during gestation and used as models of IUGR. The addition of HNE and ONE (4-oxo-2-nonenal), to cultured HTR-8/SVneo human trophoblasts activated the senescence-associated- ß-galactosidase, and generated an accumulation of acetylated proteins, consistent with a modification of SIRT1 by HNE. Altogether, these data emphasize the role of HNE and lipid peroxidation-derived aldehydes in premature placental senescence in PE and IUGR, and more generally in pathological pregnancies.

Role of oxidative stress in the dysfunction of the placental endothelial nitric oxide synthase in preeclampsia.

Preeclampsia (PE) is a multifactorial pregnancy disease, characterized by new-onset gestational hypertension with (or without) proteinuria or end-organ failure, exclusively observed in humans. It is a leading cause of maternal morbidity affecting 3-7% of pregnant women worldwide. PE pathophysiology could result from abnormal placentation due to a defective trophoblastic invasion and an impaired remodeling of uterine spiral arteries, leading to a poor adaptation of utero-placental circulation. This would be associated with hypoxia/reoxygenation phenomena, oxygen gradient fluctuations, altered antioxidant capacity, oxidative stress, and reduced nitric oxide (NO) bioavailability. This results in part from the reaction of NO with the radical anion superoxide (O2•-), which produces peroxynitrite ONOO-, a powerful pro-oxidant and inflammatory agent. Another mechanism is the progressive inhibition of the placental endothelial nitric oxide synthase (eNOS) by oxidative stress, which results in eNOS uncoupling via several events such as a depletion of the eNOS substrate L-arginine due to increased arginase activity, an oxidation of the eNOS cofactor tetrahydrobiopterin (BH4), or eNOS post-translational modifications (for instance by S-glutathionylation). The uncoupling of eNOS triggers a switch of its activity from a NO-producing enzyme to a NADPH oxidase-like system generating O2•-, thereby potentiating ROS production and oxidative stress. Moreover, in PE placentas, eNOS could be post-translationally modified by lipid peroxidation-derived aldehydes such as 4-oxononenal (ONE) a highly bioreactive agent, able to inhibit eNOS activity and NO production. This review summarizes the dysfunction of placental eNOS evoked by oxidative stress and lipid peroxidation products, and the potential consequences on PE pathogenesis.

Modification of endothelial nitric oxide synthase by 4-oxo-2(E)-nonenal(ONE) in preeclamptic placentas.

Preeclampsia (PE) is a leading cause of pregnancy complications, affecting 3-7% of pregnant women worldwide. The pathophysiology of preeclampsia involves a redox imbalance, oxidative stress and a reduced nitric oxide (NO) bioavailability. The molecular and cellular mechanisms leading to the dysfunction of the placental endothelial NO synthase (eNOS) are not clarified. This study was designed to investigate whether aldehydes generated by lipid peroxidation products (LPP), may contribute to placental eNOS dysfunction in PE. The analysis of placentas from PE-affected patients and normal pregnancies, showed a significant increase in protein carbonyl content, indicative of oxidative stress-induced protein modification, as shown by the accumulation of acrolein, 4-hydroxynonenal (HNE), and 4-oxo-2(E)-nonenal (ONE) adducts in PE placentas. In contrast, the levels of these LPP-adducts were low in placentas from normal pregnancies. Immunofluorescence and confocal experiments pointed out a colocalization of eNOS with ONE-Lys adducts, whereas eNOS was not modified in normal placentas. LC-MS/MS analysis of recombinant eNOS preincubated with ONE, allowed to identify several ONE-modified Lys-containing peptides, confirming that eNOS may undergo post-translational modification by LPP. The preincubation of HTR-8/SVneo human trophoblasts (HTR8) with ONE, resulted in ONE-Lys modification of eNOS and a reduced generation of NO. ONE inhibited the migration of HTR8 trophoblasts in the wound closure model, and this was partly restored by the NO donor, NOC-18, which confirmed the important role of NO in the invasive potential of trophoblasts. In conclusion, placental eNOS is modified by ONE in PE placentas, which emphasizes the sensitivity of this protein to oxidative stress in the disturbed redox environment of preeclamptic pregnancies.