Estrogen, angiogenesis, immunity and cell metabolism: Solving the puzzle

Estrogen plays an important role in the regulation of cardiovascular physiology and the immune system by inducing direct effects on multiple cell types including immune and vascular cells. Sex steroid hormones are implicated in cardiovascular protection, including endothelial healing in case of arterial injury and collateral vessel formation in ischemic tissue. Estrogen can exert potent modulation effects at all levels of the innate and adaptive immune systems. Their action is mediated by interaction with classical estrogen receptors (ERs), ER\u3b1 and ER\u3b2, as well as the more recently identified G-protein coupled receptor 30/G-protein estrogen receptor 1 (GPER1), via both genomic and non-genomic mechanisms. Emerging data from the literature suggest that estrogen deficiency in menopause is associated with an increased potential for an unresolved inflammatory status. In this review, we provide an overview through the puzzle pieces of how 17\u3b2-estradiol can influence the cardiovascular and immune systems

Metabolic Syndrome, Inflammation and Atherosclerosis

The inflammatory component of atherogenesis has been increasingly recognized over the last decade. Inflammation participates in all stages of atherosclerosis, not only during initiation and during evolution of lesions, but also with precipitation of acute thrombotic complications. The metabolic syndrome is associated with increased risk for development of both cardiovascular disease and type-2 diabetes in humans. Central obesity and insulin resistance are thought to represent common underlying factors of the syndrome, which features a chronic low-grade inflammatory state. Diagnosis of the metabolic syndrome occurs using defined threshold values for waist circumference, blood pressure, fasting glucose and dyslipidemia. The metabolic syndrome appears to affect a significant proportion of the population. Therapeutic approaches that reduce the levels of proinflammatory biomarkers and address traditional risk factors are particularly important in preventing cardiovascular disease and, potentially, diabetes. The primary management of metabolic syndrome involves healthy lifestyle promotion through moderate calorie restriction, moderate increase in physical activity and change in dietary composition. Treatment of individual components aims to control atherogenic dyslipidemia using fibrates and statins, elevated blood pressure, and hyperglycemia. While no single treatment for the metabolic syndrome as a whole yet exists, emerging therapies offer potential as future therapeutic approaches

Effects of ω-3 PUFA-enriched diet on growth parameters in a syngenic murine model of breast adenocarcinoma: a possible role for estrogen receptor alpha

Background: Breast cancer (BC) is the most common tumour among women and 75% of BC are estrogen receptor (ER)dependent. In particular, ERα promotes tumour growth, while ERβ has an anti-proliferative effect [1]. Epidemiological data have linked ω-3 polyunsaturated fatty acid (PUFA) consumption to lower incidence of BC and several experimental studies showed the anti-proliferative effects of ω-3 fish oil in different tumour models [2,3]. Chia seed oil is rich in α-linolenic acid (ALA 18:3 ω-3), while corn oil is rich in linoleic acid (LA 18:2 ω-6), precursors of eicosapentaenoic acid (EPA) and arachidonic acid (AA), respectively. Based on substrate availability, these FAs give rise to different eicosanoid signatures with opposite effects in cancer [4]. ω-3 PUFAs generate both anti-inflammatory prostanoids and reactive oxygen species (ROS), which in turn could affect NF-κB. Indeed, NF-κB belongs to a family of transcription factors with a key role in inflammation and oxidative stress, but its role in tumour development is still controversial [5]. The aim of the study was to determine possible processes that are activated by dietary lipids regulating BC growth and metastasis.Fil: Vara Messler, Marianela. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Instituto de Biología Celular; Argentina.Fil: Vara Messler, Marianela. Universidad de Padova. Departamento de Ciencias Farmacéuticas y Farmacológicas; Italia.Fil: Pasqualini, María Eugenia. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Instituto de Biología Celular; Argentina.Fil: Comba, Andrea. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Instituto de Biología Celular. Cátedra de Biología, Histología y Embriología; Argentina.Fil:Comba, Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ciencias de la Salud; Argentina.Fil: Toniolo, Alicia. Universidad de Padova. Departamento de Ciencias Farmacéuticas y Farmacológicas; Italia.Fil: Trenti, Annalisa. Universidad de Padova. Departamento de Ciencias Farmacéuticas y Farmacológicas; Italia.Fil: Quiroga, Patricia. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Instituto de Biología Celular; Argentina.Fil: Valentich, Mirta Ana. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Instituto de Biología Celular; Argentina.Fil: Valentich, Mirta Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ciencias de la Salud; Argentina.Fil: Bolego, Chiara. Universidad de Padova. Departamento de Ciencias Farmacéuticas y Farmacológicas; Italia.Otras Ciencias de la Salu

The Glycolytic Enzyme PFKFB3 Is Involved in Estrogen-Mediated Angiogenesis via GPER1 s

ABSTRACT The endogenous estrogen 17b-estradiol (E2) is a key factor in promoting endothelial healing and angiogenesis. Recently, proangiogenic signals including vascular endothelial growth factor and others have been shown to converge in endothelial cell metabolism. Because inhibition of the glycolytic enzyme activator phosphofructokinase-2/fructose-2,6-bisphosphatase 3 (PFKFB3) reduces pathologic angiogenesis and estrogen receptor (ER) signaling stimulates glucose uptake and glycolysis by inducing PFKFB3 in breast cancer, we hypothesized that E2 triggers angiogenesis in endothelial cells via rapid ER signaling that requires PFKFB3 as a downstream effector. We report that treatment with the selective G protein-coupled estrogen receptor (GPER1) agonist G-1 (10 210 to 10 27 M) mimicked the chemotactic and proangiogenic effect of E2 as measured in a number of short-term angiogenesis assays in human umbilical vein endothelial cells (HUVECs); in addition, E2 treatment upregulated PFKFB3 expression in a time-and concentrationdependent manner. Such an effect peaked at 3 hours and was also induced by G-1 and abolished by pretreatment with the GPER1 antagonist G-15 or GPER1 siRNA, consistent with engagement of membrane ER. Experiments with the PFKFB3 inhibitor 3-(3-pyridinyl)-1-(4-pyridinyl)-2-propen-1-one showed that PFKFB3 activity was required for estrogen-mediated HUVEC migration via GPER1. In conclusion, E2-induced angiogenesis was mediated at least in part by the membrane GPER1 and required upregulation of the glycolytic activator PFKFB3 in HUVECs. These findings unravel a previously unrecognized mechanism of estrogen-dependent endocrine-metabolic crosstalk in HUVECs and may have implications in angiogenesis occurring in ischemic or hypoxic tissues

Bisdemethoxycurcumin and Its Cyclized Pyrazole Analogue Differentially Disrupt Lipopolysaccharide Signalling in Human Monocyte-Derived Macrophages

Several studies suggest that curcumin and related compounds possess antioxidant and anti-inflammatory properties including modulation of lipopolysaccharide- (LPS-) mediated signalling in macrophage cell models. We here investigated the effects of curcumin and the two structurally unrelated analogues GG6 and GG9 in primary human blood-derived macrophages as well as the signalling pathways involved. Macrophages differentiated from peripheral blood monocytes for 7 days were activated with LPS or selective Toll-like receptor agonists for 24 h. The effects of test compounds on cytokine production and immunophenotypes evaluated as CD80+/CCR2+ and CD206+/CD163+ subsets were examined by ELISA and flow cytometry. Signalling pathways were probed by Western blot. Curcumin (2.5–10 μM) failed to suppress LPS-induced inflammatory responses. While GG6 reduced LPS-induced IκB-α degradation and showed a trend towards reduced interleukin-1β release, GG9 prevented the increase in proinflammatory CD80+ macrophage subset, downregulation of the anti-inflammatory CD206+/CD163+ subset, increase in p38 phosphorylation, and increase in cell-bound and secreted interleukin-1β stimulated by LPS, at least in part through signalling pathways not involving Toll-like receptor 4 and nuclear factor-κB. Thus, the curcumin analogue GG9 attenuated the LPS-induced inflammatory response in human blood-derived macrophages and may therefore represent an attractive chemical template for macrophage pharmacological targeting

Effects of androgens on endothelial progenitor cells in vitro and in vivo

The beneficial or detrimental effects of androgens on the cardiovascular system are debated. Endothelial progenitor cells are bone-marrow-derived cells involved in endothelial healing and angiogenesis, which promote cardiovascular health. Oestrogens are potent stimulators of endothelial progenitor cells, and previous findings have indicated that androgens may improve the biology of these cells as well. In the present study, we show that testosterone and its active metabolite dihydrotestosterone exert no effects on the expansion and function of late endothelial progenitors isolated from the peripheral blood of healthy human adult males, whereas they positively modulate early ‘monocytic’ endothelial progenitor cells. In parallel, we show that castration in rats is followed by a decrease in circulating endothelial progenitor cells, but that testosterone and dihydrotestosterone replacement fails to restore endothelial progenitor cells towards normal levels. This is associated with persistently low oestrogen levels after androgen replacement in castrated rats. In a sample of 62 healthy middle-aged men, we show that circulating endothelial progenitor cell levels are more directly associated with oestradiol, rather than with testosterone, concentrations. In conclusion, our results collectively demonstrate that androgens exert no direct effects on endothelial progenitor cell biology in vitro and in vivo

Pro-asthmatic cytokines regulate unliganded and ligand-dependent glucocorticoid receptor signaling in airway smooth muscle

To elucidate the regulation of glucocorticoid receptor (GR) signaling under pro-asthmatic conditions, cultured human airway smooth muscle (HASM) cells were treated with proinflammatory cytokines or GR ligands alone and in combination, and then examined for induced changes in ligand-dependent and -independent GR activation and downstream signaling events. Ligand stimulation with either cortisone or dexamethsone (DEX) acutely elicited GR translocation to the nucleus and, comparably, ligand-independent stimulation either with the Th2 cytokine, IL-13, or the pleiotropic cytokine combination, IL-1β/TNFα, also acutely evoked GR translocation. The latter response was potentiated by combined exposure of cells to GR ligand and cytokine. Similarly, treatment with either DEX or IL-13 alone induced GR phosphorylation at its serine-211 residue (GRSer211), denoting its activated state, and combined treatment with DEX+IL-13 elicited heightened and sustained GRSer211phosphorylation. Interestingly, the above ligand-independent GR responses to IL-13 alone were not associated with downstream GR binding to its consensus DNA sequence or GR transactivation, whereas both DEX-induced GR:DNA binding and transcriptional activity were significantly heightened in the presence of IL-13, coupled to increased recruitment of the transcriptional co-factor, MED14. The stimulated GR signaling responses to DEX were prevented in IL-13-exposed cells wherein GRSer211 phosphorylation was suppressed either by transfection with specific serine phosphorylation-deficient mutant GRs or treatment with inhibitors of the MAPKs, ERK1/2 and JNK. Collectively, these novel data highlight a heretofore-unidentified homeostatic mechanism in HASM cells that involves pro-asthmatic cytokine-driven, MAPK-mediated, non-ligand-dependent GR activation that confers heightened glucocorticoid ligand-stimulated GR signaling. These findings raise the consideration that perturbations in this homeostatic cytokine-driven GR signaling mechanism may be responsible, at least in part, for the insensirtivity to glucocorticoid therapy that is commonly seen in individuals with severe asthma