Antihypertensive methyldopa, labetalol, hydralazine, and clonidine reversed tumour necrosis factor-α inhibited endothelial nitric oxide synthase expression in endothelial-trophoblast cellular networks

Medications used to control hypertension in pregnancy also improve trophoblast and endothelial cellular interaction in vitro. Tumour necrosis factor-α (TNF-α) inhibits trophoblast and endothelial cellular interactions and simultaneously decreases endothelial nitric oxide synthase (eNOS) expression. This study investigated whether antihypertensive medications improved these cellular interactions by modulating eNOS and inducible nitric oxide synthase (iNOS) expression. Human uterine myometrial microvascular endothelial cells (UtMVECs) were pre-incubated with (or without) low dose TNF-α (0.5 ng/ml) or TNF-α plus soluble fms-like tyrosine kinase-1 (sFlt-1) (100 ng/ml). The endothelial cells were cultured on Matrigel. After endothelial cellular networks appeared, trophoblast derived HTR-8/SVneo cells were co-cultured in the presence of clinically relevant doses of methyldopa, labetalol, hydralazine or clonidine for 24 hours. Cells were retrieved from the Matrigel to extract mRNA and eNOS and iNOS expression were examined by quantitative PCR. Methyldopa, labetalol, hydralazine and clonidine reversed the inhibitory effect of TNF-α on eNOS mRNA expression. After pre-incubating endothelial cells with TNF-α and sFlt-1, all the medications except methyldopa lost their effect on eNOS mRNA expression. In the absence of TNF-α, antihypertensive medications did not change eNOS expression. The mRNA expression of iNOS was not affected by TNF-α or any medications. This study shows that selected antihypertensive medications used in the treatment of hypertension in pregnancy increase eNOS expression in vitro when induced by the inflammatory TNF-α. The antiangiogenic molecule sFlt-1 may antagonise the potential benefit of these medications by interfering with the NOS pathway

Nitric oxide (NO) reversed TNF-α inhibition of trophoblast interaction with endothelial cellular networks

Introduction. The interaction between trophoblast cells and maternal uterine endothelium is important for placental vascular modelling. Nitric oxide (NO) is a potent vasorelaxant that regulates systemic blood pressure and is reduced in preeclampsia. NO may affect placental cell interaction. Objectives. This study was to examine whether NO plays a role in regulating TNF-α induced inhibition of trophoblast cell integration into endothelial cellular networks in-vitro. Methods. Red fluorescent-labelled human uterine myometrial microvascular endothelial cells (UtMVECs) were seeded on Matrigel. After endothelial cellular networks formed, green fluorescent-labelled HTR-8/SVneo trophoblast cells were co-cultured with endothelial cells, together with/without TNF-α (0.5 ng/ml) and/or NO donor, sodium nitroprusside dihydrate (SNP) (100 μM). Images were captured after 24 h. The effects on HTR-8/SVneo cell integration were quantified by Image Analysis software. The cells were then recovered from Matrigel to extract mRNA. Quantitative PCR was performed to evaluate the expression of eNOS, VCAM-1 and E-selectin. The concentrations of sVCAM-1 and sE-selectin in the conditioned medium were measured by ELISA. Results. TNF-α inhibited HTR-8/SVneo trophoblast cell integration into endothelial cellular networks, as well as decreased eNOS mRNA expression. Increases in VCAM-1 and E-selectin in cellular mRNA and protein concentrations in the conditioned medium were also seen. The NO donor reversed the inhibitory effect of TNF-α on trophoblast integration and increased eNOS mRNA expression. SNP also reduced sE-selectin and sVCAM-1 expressions which were increased by TNF-α in the conditioned medium. Conclusion. Our data suggest the inhibitory effect of TNF-α on trophoblast integration may be mediated by NO, via reducing endothelial cell activation

Antihypertensive drugs methyldopa, labetalol, hydralazine, and clonidine improve trophoblast interaction with endothelial cellular networks in vitro

Ojectives: The interaction between trophoblasts and maternal endothelium is important for placental vascular modeling. Failure of uterine spiral artery transformation is linked to the etiopathology of preeclampsia. Antihypertensive medications used to control hypertension in early pregnancy can alter placental and circulating cytokines. This study investigated whether selected antihypertensive drugs can modulate the interaction between trophoblast and endothelial cells. Methods: Human uterine myometrial microvascular endothelial cells were preincubated with (or without) low-dose tumor necrosis factor-α (TNF-α; 0.5ng/ml) or TNF-α and soluble fms-like tyrosine kinase 1 (sFlt-1; 100ng/ml). Red fluorescent-labeled endothelial cells were then cultured on Matrigel. After appearance of endothelial cellular networks, green fluorescent-labeled HTR-8/SVneo trophoblast cells were cocultured in the presence of pharmacological doses of methyldopa, labetalol, hydralazine, and clonidine. Images were captured after 24h and drug effects on HTR-8/SVneo cell integration were quantified by Image Analysis software. The conditioned medium was collected to measure sFlt-1, vascular endothelial growth factor (VEGF), placental growth factor, interleukin-10, and interleukin-6 by ELISA. Results: Methyldopa, labetalol, hydralazine, and clonidine increased trophoblast integration into TNF-α-preincubated endothelial cellular networks. In conditioned medium, sFlt-1 was reduced by methyldopa, hydralazine, and clonidine alone. VEGF was increased by methyldopa. A decrease in placental growth factor was seen by methyldopa and also in nontreated endothelial cell coculture of the other three drugs. Conclusion: Some antihypertensive drugs used in pregnancy may improve the cellular interaction between trophoblast and endothelial cells exposed to TNF-α. Methyldopa, hydralazine, and clonidine reduced sFlt-1 concentration in culture medium, whereas labetalol increased trophoblast integration independently of sFlt-1. Methyldopa increased VEGF concentration. Some pregnancy-related antihypertensives may affect placental vascularization

TNF-α inhibits trophoblast integration into endothelial cellular networks

Preeclampsia has been linked to shallow trophoblast invasion and failure of uterine spiral artery transformation. Interaction between trophoblast cells and maternal uterine endothelium is critically important for this remodelling. The aim of our study was to investigate the effect of TNF-α on the interactions of trophoblast-derived JEG-3 cells into capillary-like cellular networks. We have employed an in vitro trophoblast-endothelial cell co-culture model to quantify trophoblast integration into endothelial cellular networks and to investigate the effects of TNF-α. Controlled co-cultures were also treated with anti-TNF-α antibody (5 μg/ml) to specifically block the effect of TNF-α. The invasion was evaluated by performing quantitative PCR (Q-PCR) to analyse gene expression of matrix metalloproteinases-2 (MMP-2), MMP-9, tissue inhibitor of matrix metalloproteinase (TIMP)-1, integrins (α1β1 and α6β4), plasminogen activator inhibitor (PAI)-1, E-cadherin and VE-cadherin. JEG-3 cell integration into endothelial networks was significantly inhibited by exogenous TNF-α. The inhibition was observed in the range of 0.2–5 ng/ml, to a maximum 56% inhibition at the highest concentration. This inhibition was reversed by anti-TNF-α antibody. Q-PCR analysis showed that mRNA expression of integrins α1β1 and MMP-2 was significantly decreased. VE-cadherin mRNA expression was significantly up-regulated (32–80%, p < 0.01) but its protein concentration in the cell lysates was significantly reduced (20–45%, p < 0.01). PAI-1, MMP-9, TIMP-1 and E-cadherin were not affected. In conclusion, TNF-α can inhibit trophoblast-like cells (JEG-3) integration into maternal endothelial cellular networks, and this process involves the inhibition of MMP-2 and a failure of integrins switch from α6β4 to α1β1. These molecular correlations reflect the changes identified in human preeclampsia

The protective effect of apolipoprotein in models of trophoblast invasion and preeclampsia

Preeclampsia is a hypertensive disorder of pregnancy. It is associated with abnormal placentation via poor placental invasion of the uterine vasculature by trophoblast cells, leading to poor placental perfusion, oxidative stress, and inflammation, all of which are implicated in its pathogenesis. A dyslipidemia characterized by low plasma levels of high-density lipoproteins (HDL) and elevated triglycerides has been described in preeclampsia. Apolipoprotein A-I (apoA-I), a constituent of HDL is an antiinflammatory agent. This study investigated whether apoA-I protects against hypertension and adverse placental changes in a proinflammatory cytokine (TNF-α)-induced model of preeclampsia. Further, this study investigated whether apoA-I protects against the inhibitory effect of TNF-α in a human in vitro model of trophoblast invasion. Administration of apoA-I to pregnant mice before infusion with TNF-α resulted in a significant reduction in the cytokine-induced increase in systolic blood pressure. MRI measurement of T2 relaxation, a parameter that is tissue specific and sensitive to physiological changes within tissues, showed a reversal of TNF-α-induced placental changes. Preincubation of endothelial cells with apoA-I protected against the TNF-α-induced inhibition of HTR-8/SVneo (trophoblast) cell integration into endothelial (UtMVEC) networks. These data suggest that a healthy lipid profile may affect pregnancy outcomes by priming endothelial cells in preparation for trophoblast invasion

Placental growth factor reduces blood pressure in a uteroplacental ischemia model of preeclampsia in nonhuman primates

An imbalance in the angiogenesis axis during pregnancy manifests as clinical preeclampsia because of endothelial dysfunction. Circulating soluble fms-like tyrosine kinase 1 (sFLT-1) increases and placental growth factor (PlGF) reduces before and during disease. We investigated the clinical and biochemical effects of replenishing the reduced circulating PlGF with recombinant human PlGF (rhPlGF) and thus restoring the angiogenic balance. Hypertensive proteinuria was induced in a nonhuman primate (Papio hamadryas) by uterine artery ligation at 136 days gestation (of a 182-day pregnancy). Two weeks after uteroplacental ischemia, rhPlGF (rhPlGF, n=3) or normal saline (control, n=4) was administered by subcutaneous injection (100 μg/kg per day) for 5 days. Blood pressure was monitored by intra-arterial radiotelemetry and sFLT-1 and PlGF by ELISA. Uteroplacental ischemia resulted in experimental preeclampsia evidenced by increased blood pressure, proteinuria, and endotheliosis on renal biopsy and elevated sFLT-1. PlGF significantly reduced after uteroplacental ischemia. rhPlGF reduced systolic blood pressure in the treated group (-5.2±0.8 mm Hg; from 132.6±6.6 mm Hg to 124.1±7.6 mm Hg) compared with an increase in systolic blood pressure in controls (6.5±3 mm Hg; from 131.3±1.5 mm Hg to 138.6±1.5 mm Hg). Proteinuria reduced in the treated group (-72.7±55.7 mg/mmol) but increased in the control group. Circulating levels of total sFLT-1 were not affected by the administration of PlGF; however, a reduction in placental sFLT-1 mRNA expression was demonstrated. There was no significant difference between the weights or lengths of the neonates in the rhPlGF or control group; however, this study was not designed to assess fetal safety or outcomes. Increasing circulating PlGF by the administration of rhPlGF improves clinical parameters in a primate animal model of experimental preeclampsia