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.

Effects of red clover extracts on breast cancer cell migration and invasion.

Postmenopausal hormone therapy is associated with increased incidence of breast cancer. For this reason alternative therapeutic options to treat menopausal symptoms have been developed. Red clover extracts (RCE) are rich in isoflavones, particularly genistein and daidzein and they have been proved to be effective in reducing vasomotor symptoms in a number of studies. Due to their partial selectivity of action on estrogen receptors (ERs) these compounds have been claimed to be safer on the breast. In this article, we explored the action of RCE on motility and invasion of ER positive breast cancer cells and we partially characterized the signaling mechanisms. The principal isoflavones contained in RCE acted as weak estrogenic compounds when administered alone. However, when provided in association with physiological amounts of estradiol, RCE acted as estrogen antagonist on remodeling of actin cytoskeleton that are requested to enact cell movement and with related modifications of the activity of actin-binding proteins, such as moesin. These results offer novel information on the molecular actions of isoflavones contained in red clover on breast cancer cells, supporting a possible action of these molecules as natural selective estrogen receptor modulators in the presence of physiological amounts of estrogens.

Dydrogesterone exerts endothelial anti-inflammatory actions decreasing expression of leukocyte adhesion molecules.

Clinical observations and basic studies show that progesterone and progestins have a variable influence on endothelial function. Dydrogesterone (DG) is a widely used progestin, but its endothelial actions have not been thoroughly assessed. In this study, we investigated the effects of DG and its metabolite 20-α-dihydro-dydrogesterone (DHD), natural progesterone as well as medroxyprogesterone acetate, on the expression of leukocyte adhesion molecules in human endothelial cells using an in vitro experimental endothelial inflammation system. Our findings show that all progestins significantly suppress endothelial expression of vascular cell adhesion molecule-1 (VCAM-1) and inter-cellular adhesion molecule-1 (ICAM-1) induced by bacterial lypopolysaccharide (LPS). These inhibitory effects of DG and DHD require activation of progesterone receptor. DG and DHD decrease adhesion molecule expression associated with LPS administration by preventing nuclear translocation of the pro-inflammatory transcription factor nuclear factor-κB. In addition, DG and DHD do not alter the anti-inflammatory effects of 17ß-estradiol. In conclusion, DG and DHD decrease endothelial inflammatory responses induced by LPS, via reduced expression of the pro-atherogenic adhesion molecules VCAM-1 and ICAM-1. These actions may be relevant for the vascular effects of DG.

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.