Feto-placental nitric oxide, asymmetric dimethylarginine and vascular endothelial growth factor (VEGF) levels and VEGF gene polymorphisms in severe preeclampsia.

OBJECTIVE: To measure plasma nitric oxide (NO), asymmetric dimethylarginine (ADMA) and vascular endothelial growth factor (VEGF) levels and VEGF gene polymorphisms in fetal circulation in severe preeclampsia. METHODS: Cord vessels of singleton gestations complicated with severe preeclampsia 36 weeks or more (n = 31) and controls were sampled upon delivery for analyte measuring. Additionally, DNA was extracted from umbilical vein whole blood to determine the frequency of VEGF gene single nucleotide polymorphisms (SNPs): -2578 A/C, -1498 C/T, -1154 A/G, -634 C/G and +936 C/T. Coefficient correlations between analyte levels and placental and neonatal weight were calculated. RESULTS: NO plasma levels in umbilical vessels (artery and vein) were significantly higher in preeclampsia cases as compared to controls (4.67 ± 3.0 vs. 0.82 ± 0.90; 4.46 ± 3.0 vs. 0.82 ± 0.99 mmol/L, respectively, p = 0.0001 both). ADMA levels displayed a similar increased trend in both fetal vessels, but this did not reach statistical significance (2.57 ± 1.03 vs. 2.34 ± 0.57; 2.74 ± 0.94 vs. 2.42 ± 0.59 mmol/L, respectively, p > 0.05). VEGF was significantly lower in artery but not in vein in preeclampsia cases (200.48 ± 225.62 vs. 338.61 ± 287.03 pg/mL, p = 0.04). A significant positive correlation was found between NO and ADMA levels (artery and vein) among preeclampsia cases. Overall, the frequency of the studied VEGF gene SNPs did not differ among pre-eclamptic cases and controls; nevertheless, a significant trend toward lower umbilical vein VEGF levels was observed in pre-eclampsia cases in the presence of -2578 CC and -1154 AG genotypes. CONCLUSION: Near term gestations complicated with severe preeclampsia presented higher NO levels in fetal circulation, which correlated to ADMA and lower artery VEGF values. More research is warranted to confirm that selected VEGF SNPs may be associated with lower umbilical vein VEGF.

Estrogen regulates endothelial migration via plasminogen activator inhibitor (PAI-1).

Endothelial plasminogen activator inhibitor (PAI-1) controls vascular remodeling, angiogenesis and fibrinolysis. PAI-1 blood levels in women are related to estrogen. The aim of this study was to characterize the signaling pathways through which estrogen regulates PAI-1 in endothelial cells. Furthermore, we aimed to investigate whether PAI-1 is implicated in the control of endothelial migration by estrogen. Cultured human umbilical vein endothelial cells (HUVECs) and ovariectomized rats were used to test the effects of 17ß-estradiol (E(2)) on PAI-1 expression and its role on endothelial migration. At physiological concentrations, E(2) increases the expression of PAI-1 in HUVEC within 6-12 h through activation of a signaling cascade initiated by estrogen receptor α and involving G proteins, phosphatidylinositol-3-OH kinase and Rho-associated kinase II. ROCK-II activation turns into an over-expression of c-Jun and c-Fos that is required for E(2)-induced expression of PAI-1. Estrogen-induced PAI-1 expression is implicated in HUVEC horizontal migration. PAI-1 regulation is found also in vivo, in female rats, where ovariectomy is associated with reduced PAI-1 expression, while estrogen replacement counteracts this change. In conclusion, E(2) increases PAI-1 synthesis in human endothelial cells and in rodent aorta through a G protein-initiated signaling that targets early-immediate gene expression. This regulatory pathway is implicated in endothelial cell migration. These findings describe new mechanisms of action of estrogens in the vessels, which may be important for vascular remodeling and hemostasis.

Estrogen-like effects of wine extracts on nitric oxide synthesis in human endothelial cells.

Endothelial dysfunction frequently ensues during the climacteric due to hormonal and metabolic changes. Non-pharmacological interventions such as lifestyle and dietary modifications are emerging as valuable strategies to counteract the cardiovascular consequences of ageing. A number of chemical components of wine, including alcohol and some polyphenols, are known to be active on the vessels. However, the molecular mechanisms through which they modulate endothelial function are largely unclear. The aim of this study was to investigate the effects of non-alcoholic wine fractions from five different wines on the synthesis of nitric oxide (NO) via the expression and enzymatic activation of the endothelial nitric oxide synthase (eNOS) in human endothelial cells. All non-alcoholic fractions studied increased NO synthesis, although with different potencies. All wine extracts maximally enhanced NO production at doses in the range achieved with a moderate wine intake, with decreasing effects with further increases of the dose. Interestingly, a part of these actions was recruited via estrogen receptors (ERs). Within the polyphenols with known binding activity for ERs contained in the tested wines, resveratrol, epicatechin, syringic acid, apigenin, malvidin and ellagic acid were largely responsible for eNOS activation. These findings show that some of the non-alcoholic components of wine enhance the production of NO by the vessels acting on ERs, and suggest that a moderate intake of wine may benefit the cardiovascular system through estrogen-like effects.

Estrogen receptor-{alpha} promotes endothelial cell motility through focal adhesion kinase.

Sex steroids play a key role in cell movement and tissue organization. Cell migration requires the integration of events that induce changes in cell structure such as protrusion, polarization and traction toward the direction of migration. These actions are driven by actin remodeling and are stabilized by the development of adhesion sites to extracellular matrix via transmembrane receptors linked to the actin cytoskeleton. Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that facilitates cell migration via the control of the turnover of focal adhesion complexes. In this work, we demonstrated that 17ß-estradiol (E(2)) regulates actin remodeling and cell movement in human umbilical vein endothelial cells through the recruitment of FAK. E(2) induces phosphorylation of FAK and its translocation toward membrane sites where focal adhesion complexes are assembled. This process is triggered via a Gα/Gß protein-dependent, rapid extra-nuclear signaling of estrogen receptor-α (ERα) that interacts in a multiprotein complex with c-Src, phosphatidylinositol 3-OH kinase and FAK. Phosphorylation of FAK is fundamental for its activation, translocation to the plasmatic membrane and the subsequent formation of focal adhesion complexes. In conclusion, we found that ERα enhances endothelial cell motility through the dynamic control of actin arrangement and the formation of focal adhesion complexes. The identification of these processes broadens the understanding of the actions of estrogens on endothelial cells and could be relevant in physiological or pathological settings.