Maternal Plasma From Pregnant Women With Umbilical Placental Vascular Disease Does Not Affect Endothelial Cell mRNA Expression of Nitric Oxide Synthase

OBJECTIVE

In placental vascular disease identified by umbilical artery Doppler study we have shown the existence of a factor in fetal plasma that causes activation of endothelial cells in culture with expression of cell adhesion molecules and nitric oxide synthase, apoptosis, and proinflammatory cytokine production. The present work was carried out to investigate a maternal origin for this factor active in the fetal circulation.

METHODS

We collected maternal plasma from pregnant women with Doppler-defined umbilical placental vascular disease and examined its effect on endothelial cells in culture. Aliquots from a common culture of human umbilical vein endothelial cells (HUVEC) were incubated with maternal plasma from women with normal pregnancy (n = 23), umbilical placental vascular disease defined by abnormal umbilical artery Doppler (n = 30, with or without preeclampsia), and preeclampsia with normal umbilical artery Doppler (n = 14). The expression of mRNA for inducible and endothelial constitutive nitric oxide synthase (iNOS and ecNOS, respectively) was assessed by reverse transcriptase polymerase chain reaction.

RESULTS

There was no significant increase in either the iNOS or the ecNOS mRNA expression by HUVEC cultured with maternal plasma from pregnancies with umbilical placental vascular disease compared with normal pregnancy (iNOS 1.49 +/- 0.35 versus 1.38 +/- 0.25; ecNOS 1.51 +/- 0.35 versus 1.25 +/- 0.27; P >.05). In the placental vascular disease group the results were similar for the presence or absence of maternal preeclampsia. In the samples from women with preeclampsia with normal umbilical Doppler, both iNOS and ecNOS mRNA expression (iNOS 1.42 +/- 0.53; ecNOS 1.46 +/- 0.39; P >.05) did not differ from normal.

CONCLUSION

Maternal plasma from pregnancies with umbilical placental vascular disease did not affect endothelial cell expression of nitric oxide synthase. This finding does not support a maternal origin for the factor demonstrated in fetal plasma. These results suggest separate pathogenic pathways for the endothelial cell activation seen in preeclampsia and fetal growth restriction associated with abnormal umbilical artery Doppler flow velocity waveforms. These findings are also consistent with the concept that the vascular pathology in the fetal placenta may be primary and that the uteroplacental circulation is reduced in response rather than acts as a constraint.

Fetuses Delivered Following Preterm Prelabor Rupture of the Membranes are Capable of Stimulating a Proinflammatory Response in Endothelial Cells

OBJECTIVE

Preterm premature rupture of the membranes (PROM) has been attributed to ascending infection and a choriodecidual inflammatory response (ie, on the maternal side). However, on the fetal side those most at risk of morbidity have a systemic proinflammatory cytokine response. We have recently defined a similar proinflammatory response in pregnancies complicated by vascular disease on the fetal side of the placenta. A factor(s) present in fetal plasma from these pregnancies can stimulate human umbilical vein endothelial cells (HUVECs) to express mRNA for the proinflammatory cytokines, interleukin (IL)-6 and IL-8. The hypothesis of this study was that a similar factor(s) was present in preterm PROM.

METHODS

A standard culture of HUVECs was incubated with fetal plasma, obtained immediately following delivery, from normal pregnancies delivering vaginally at term (n=16) and pregnancies delivering following preterm PROM (n=19). Expression of mRNA for IL-6 and IL-8 was assessed by reverse transcription polymerase chain reaction (RT-PCR) and standardized to GAPDH mRNA expression.

RESULTS

Endothelial cell expression of IL-6 mRNA (median [25-75th centile] 0.295 [0.252-0.507] vs term vaginal delivery 0.208 [0.151-0.307]; P=.009) was enhanced in response to the fetal plasma from PROM cases compared to pregnancies delivering vaginally at term. In contrast, mRNA expression of IL-8 (median [25-75th centile] preterm PROM 0.41 [0.21-0.78] vs term vaginal delivery 0.49 [0.16-0.68]; P=.46) was not different in the two groups.

CONCLUSIONS

We have demonstrated that in fetuses delivered following preterm PROM there is a factor(s) capable of stimulating a local endothelial cell proinflammatory cytokine (IL-6) response. This factor(s) that we have demonstrated may be responsible for the increased cytokine production seen in fetuses with the fetal inflammatory response syndrome.

Terminal monosaccharide expression on amniotic glycoproteins as biomarkers of fetus maturity

Glycotypes, particularly those that terminate with sialic acid and fucose are known to play a fundamental role in human development, during implantation, growth and differentiation of fetal tissues. The present review describes changes in the exposition of terminal sialic acid and fucose isoforms in the amniotic fluid glycoconjugates, α1-acid glycoprotein and fibronectin during critical stages of pregnancy, i.e. second and third trimester, perinatal period, delivery and post-date pregnancy. The distinct amniotic glycoforms are suggested to be implicated in regulatory processes to ensure homoeostasis during pregnancy and to protect the fetus. These may have the potential of becoming additional laboratory makers in obstetrics to monitor pregnancy.

Anti-inflammatory therapy in an ovine model of fetal hypoxia induced by single umbilical artery ligation

Perinatal morbidity and mortality are significantly higher in pregnancies complicated by chronic hypoxia and intrauterine growth restriction (IUGR). Clinically, placental insufficiency and IUGR are strongly associated with a fetoplacental inflammatory response. To explore this further, hypoxia was induced in one fetus in twin-bearing pregnant sheep (n = 9) by performing single umbilical artery ligation (SUAL) at 110 days gestation. Five ewes were administered the anti-inflammatory drug sulfasalazine (SSZ) daily, beginning 24 h before surgery. Fetal blood gases and inflammatory markers were examined. In both SSZ- and placebo-treated ewes, SUAL fetuses were hypoxic and growth-restricted at 1 week (P < 0.05). A fetoplacental inflammatory response was observed in SUAL pregnancies, with elevated pro-inflammatory cytokines, activin A and prostaglandin E2. SSZ did not mitigate this inflammatory response. It is concluded that SUAL induces fetal hypoxia and a fetoplacental inflammatory response and that SSZ does not improve oxygenation or reduce inflammation. Further studies to explore whether alternative anti-inflammatory treatments may improve IUGR outcomes are warranted.