Testosterone and estradiol modulate TNF-alpha-induced expression of adhesion molecules in endothelial cells

Influences of Sex and Estrogen in Arterial and Valvular Calcification

Vascular and cardiac valvular calcification was once considered to be a degenerative and end stage product in aging cardiovascular tissues. Over the past two decades, however, a critical mass of data has shown that cardiovascular calcification can be an active and highly regulated process. While the incidence of calcification in the coronary arteries and cardiac valves is higher in men than in age-matched women, a high index of calcification associates with increased morbidity, and mortality in both sexes. Despite the ubiquitous portending of poor outcomes in both sexes, our understanding of mechanisms of calcification under the dramatically different biological contexts of sex and hormonal milieu remains rudimentary. Understanding how the critical context of these variables inform our understanding of mechanisms of calcification-as well as innovative strategies to target it therapeutically-is essential to advancing the fields of both cardiovascular disease and fundamental mechanisms of aging. This review will explore potential sex and sex-steroid differences in the basic biological pathways associated with vascular and cardiac valvular tissue calcification, and potential strategies of pharmacological therapy to reduce or slow these processes.

Androgen deprivation therapy and cardiovascular disease: what is the linking mechanism?

The past decade has brought increased awareness of the potential adverse effects of androgen deprivation therapy (ADT) in men with prostate cancer. Arguably the most important and controversial of these is the increased risk of cardiovascular morbidity and mortality. Although multiple observational studies have shown that men treated with ADT are at increased risk of developing atherosclerotic cardiovascular disease, our understanding of the biological mechanisms that might underlie this phenomenon is still evolving. In this review, we discuss some of the mechanisms that have been proposed to date, including ADT-induced metabolic changes that promote the development and progression of atherosclerotic plaques as well as direct local effects of hormonal factors on plaque growth, rupture and thrombosis.

Association of the polymorphism in the androgen receptor gene and endothelial function in men with type 2 diabetes

In recent years, actively studied the effect of androgen deficiency on the cardiovascular system, including endothelial function. Genomic effects of testosterone caused by the length of CAG repeats polymorphism in the androgen receptor (AR) gene.Aim. To examine the association of the polymorphism in the AR gene and carbohydrate, lipid metabolism, endothelial function in men with type 2 diabetes.Materials and methods. We examined 88 men, aged 40-65 years (mean age 53±6,4years) with type 2 diabetes. All patients underwent the study of carbohydrate and lipid metabolism, the assessment of vasomotor endothelial function of the brachial artery by ultrasound sonography, were studied biochemical markers of endothelial dysfunction – ICAM-1, VCAM-1, p-selectin, e-selectin, resistin and number of CAG-repeats in the AR gene. Statistical analysis was performed using the application package SPSS 21,0 using regression analysis.Results. The number of CAG repeats had a significant positive regression to the level of total testosterone, a weak negative regression of the number of CAG repeats in the AR gene and lipid metabolism: triglycerides, LDL, atherogenic index. The assessment of the brachial artery ultrasonography revealed negative regression of the baseline brachial artery diameter and blood flow velocity in the endothelium-dependent vasodilation. The number of CAG repeats was significantly correlated with the levels of p-selectin and resistin. Thus, increasing the number of CAG repeats in the AR gene via a weakening of sensitivity to androgens leads to disruption of endothelial function in men with type 2 diabetes. Increasing the number of CAG repeats in the AR gene leads to deterioration of linear flow velocity during the test with reactive hyperemia with increasing production of p-selectin and resistin.Conclusions. The number of CAG repeats in the AR gene can be regarded as a predictor of the development and progression of cardiovascular lesions in men with type 2 diabetes.

Testosterone-derived estradiol production by male endothelium is robust and dependent on p450 aromatase via estrogen receptor alpha

Vascular endothelium expresses both the estrogen receptors (ERs) α and β, and ERα mediates development of early atherosclerosis in male mice. This process is thought to be testosterone-dependent. We hypothesized that male murine aortic endothelium produces robust levels of estradiol by aromatase conversion of testosterone, and that regulation of this process is mediated by the presence of ERs, primarily ERα. Aortic endothelium was isolated from ERα knockout (ERα -/-) and wild-type (ERα +/+) male mice and treated with testosterone or the 5α reduction product dihydrotestosterone (DHT), with or without the P450 aromatase inhibitor anastrazole, or a non-specific estrogen receptor antagonist. Aromatase gene expression and estradiol production were assayed. Treatment with testosterone, but not DHT, caused increased aromatase expression and estradiol production in ERα +/+ endothelium that was attenuated by disruption of ERα in the ERα -/- group. Anastrazole inhibition of aromatase reduced testosterone-induced aromatase expression and estradiol levels in both ERα -/- and ERα +/+ endothelium. Antagonism of both ERs decreased testosterone-induced aromatase expression in both wild-type and knockout groups. The effects of the receptor antagonist on estradiol production differed between the two groups, however, with a reduction in estradiol release from the ERα +/+ cells and complete abolition of estradiol release from the ERα -/- cells. Thus, estradiol production in vascular endothelium from male mice is robust, depends on the aromatic conversion of testosterone and requires functional ERα to achieve maximal levels of estradiol generation. Local vascular production of aromatase-mediated estradiol in response to circulating testosterone may affect ERα-dependent mechanisms to increase susceptibility to early atheroma formation in male mice. This pathway may have important therapeutic relevance for reducing the risk of atherosclerotic cardiovascular disease in human males.

Blockade of p-selectin is sufficient to reduce MHC I antibody-elicited monocyte recruitment in vitro and in vivo

Donor-specific HLA antibodies significantly lower allograft survival, but as yet there are no satisfactory therapies for prevention of antibody-mediated rejection. Intracapillary macrophage infiltration is a hallmark of antibody-mediated rejection, and macrophages are important in both acute and chronic rejection. The purpose of this study was to investigate the Fc-independent effect of HLA I antibodies on endothelial cell activation, leading to monocyte recruitment. We used an in vitro model to assess monocyte binding to endothelial cells in response to HLA I antibodies. We confirmed our results in a mouse model of antibody-mediated rejection, in which B6.RAG1(-/-) recipients of BALB/c cardiac allografts were passively transferred with donor-specific MHC I antibodies. Our findings demonstrate that HLA I antibodies rapidly increase intracellular calcium and endothelial presentation of P-selectin, which supports monocyte binding. In the experimental model, donor-specific MHC I antibodies significantly increased macrophage accumulation in the allograft. Concurrent administration of rPSGL-1-Ig abolished antibody-induced monocyte infiltration in the allograft, but had little effect on antibody-induced endothelial injury. Our data suggest that antagonism of P-selectin may ameliorate accumulation of macrophages in the allograft during antibody-mediated rejection.

G-protein coupled receptor 30 (GPR30): a novel regulator of endothelial inflammation

Estrogen, the female sex hormone, is known to exert anti-inflammatory and anti-atherogenic effects. Traditionally, estrogen effects were believed to be largely mediated through the classical estrogen receptors (ERs). However, there is increasing evidence that G-protein coupled receptor 30 (GPR30), a novel estrogen receptor, can mediate many estrogenic effects on the vasculature. Despite this, the localization and functional significance of GPR30 in the human vascular endothelium remains poorly understood. Given this background, we examined the subcellular location and potential anti-inflammatory roles of GPR30 using human umbilical vein endothelial cells as a model system. Inflammatory changes were induced by treatment with tumor necrosis factor (TNF), a pro-inflammatory cytokine involved in atherogenesis and many other inflammatory conditions. We found that GPR30 was located predominantly in the endothelial cell nuclei. Treatment with the selective GPR30 agonist G-1 partially attenuated the TNF induced upregulation of pro-inflammatory proteins such as intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). This effect was completely abolished by the selective GPR30 antagonist G-15, suggesting that it was indeed mediated in a GPR30 dependent manner. Interestingly, estrogen alone had no effects on TNF-treated endothelium. Concomitant activation of the classical ERs blocked the anti-inflammatory effects of G-1, indicating opposing effects of GPR30 and the classical ERs. Our findings demonstrate that endothelial GPR30 is a novel regulator of the inflammatory response which could be a potential therapeutic target against atherosclerosis and other inflammatory diseases.

Estradiol modulates tumor necrosis factor-induced endothelial inflammation: role of tumor necrosis factor receptor 2

The sex hormone estradiol (E(2)) appears to mediate both anti-atherogenic and pro-inflammatory effects in premenopausal women, suggesting a complex immunomodulatory role. Tumor necrosis factor (TNF) is a key pro-inflammatory cytokine involved in the pathogenesis of atherosclerosis and other inflammatory diseases. Alterations at the TNF receptors (TNFRs) and their downstream signaling/transcriptional pathways can affect inflammatory responses. Given this background, we hypothesized that chronic E(2) exposure would alter endothelial inflammatory response involving modulation at the levels of TNFRs and signaling pathways. HUVECs were used as the model system. Pre-treatment with E(2) did not significantly alter TNF-induced upregulation of pro-inflammatory molecules ICAM-1 (3-6 times) and VCAM-1 (5-7 times). However, pharmacological inhibition of transcriptional pathways suggested a partial shift from NF-ĸB (from 97 to 64%) towards the JNK/AP-1 pathway in ICAM-1 upregulation on E(2) treatment. In contrast, VCAM-1 expression remained NF-ĸB dependent in both control (∼96%) and E(2) treated (∼85%) cells. The pro-inflammatory TNF effects were mediated by TNFR1. Interestingly, E(2) pre-treatment increased TNFR2 levels in these cells. Concomitant TNFR2 activation (but not TNFR1 activation alone) led to the shift towards JNK/AP-1-mediated ICAM-1 upregulation in E(2)-treated cells, suggesting the effects of chronic E(2) to be dependent on TNFR2 signaling.

Androgens inhibit tumor necrosis factor-α-induced cell adhesion and promote tube formation of human coronary artery endothelial cells

Endothelial cells contribute to the function and integrity of the vascular wall, and a functional aberration may lead to atherogenesis. There is increasing evidence on the atheroprotective role of androgens. Therefore, we studied the effect of the androgens-testosterone and dihydrotestosterone-and estradiol on human coronary artery endothelial cell (HCAEC) function. We found by MTT assay that testosterone is not cytotoxic and enhances HCAEC proliferation. The effect of testosterone (10-50 nM), dihydrotestosterone (5-50 nM), and estradiol (0.1-0.4 nM) on the adhesion of tumor necrosis factor-α (TNF-α)-stimulated HCAECs was determined at different time points (12-96 h) by assessing their binding with human monocytic THP-1 cells. In addition, the expression of adhesion molecules, vascular cell adhesion molecule-1 (VCAM-1) and intracellular adhesion molecule-1 (ICAM-1), was determined by ELISA and Western blot analysis. Both testosterone and dihydrotestosterone attenuated cell adhesion and the expression of VCAM-1 and ICAM-1 in a dose- and time-dependent manner. Furthermore, androgen treatment for a longer duration inhibited cell migration, as demonstrated by wound-healing assay, and promoted tube formation on a Matrigel. Western blot analysis demonstrated that the expression of phosphorylated endothelial nitric oxide synthase (eNOS) increased, whereas that of inducible nitric oxide synthase (iNOS) decreased following the 96-h steroid treatment of TNF-α-stimulated HCAECs. Our findings suggest that androgens modulate endothelial cell functions by suppressing the inflammatory process and enhancing wound-healing and regenerative angiogenesis, possibly through an androgen receptor (AR)-dependent mechanism.

The effect of diet and exercise on markers of endothelial function in overweight and obese women with polycystic ovary syndrome

BACKGROUND

Women with polycystic ovary syndrome (PCOS) present with vascular abnormalities, including elevated markers of endothelial dysfunction. There is limited evidence for the effect of lifestyle modification and weight loss on these markers. The aim of this study was to determine if 20 weeks of a high-protein energy-restricted diet with or without exercise in women with PCOS could improve endothelial function.

METHODS

This is a secondary analysis of a subset of 50 overweight/obese women with PCOS (age: 30.3 ± 6.3 years; BMI: 36.5 ± 5.7 kg/m(2)) from a previous study. Participants were randomly assigned by computer generation to one of three 20-week interventions: diet only (DO; n = 14, ≈ 6000 kJ/day), diet and aerobic exercise (DA; n = 16, ≈ 6000 kJ/day and five walking sessions/week) and diet and combined aerobic-resistance exercise (DC; n = 20, ≈ 6000 kJ/day, three walking and two strength sessions/week). At Weeks 0 and 20, weight, markers of endothelial function [vascular cell adhesion molecule-1 (sVCAM-1), inter-cellular adhesion molecule-1 (sICAM-1), plasminogen activator inhibitor-1 (PAI-1) and asymmetric dimethylarginine (ADMA)], insulin resistance and hormonal profile were assessed.

RESULTS

All three treatments resulted in significant weight loss (DO 7.9 ± 1.2%, DA 11.0 ± 1.6%, DC 8.8 ± 1.1; P < 0.001 for time; P = 0.6 time × treatment). sVCAM-1, sICAM-1 and PAI-1 levels decreased with weight loss (P≤ 0.01), with no differences between treatments (P ≥ 0.4). ADMA levels did not change significantly (P = 0.06). Testosterone, sex hormone-binding globulin and the free androgen index (FAI) and insulin resistance also improved (P < 0.001) with no differences between treatments (P ≥ 0.2). Reductions in sVCAM-1 were correlated to reductions in testosterone (r = 0.32, P = 0.03) and FAI (r = 0.33, P = 0.02) as well as weight loss (r= 0.44, P = 0.002). Weight loss was also associated with reductions in sICAM-1 (r= 0.37, P = 0.008).

CONCLUSIONS

Exercise training provided no additional benefit to following a high-protein, hypocaloric diet on markers of endothelial function in overweight/obese women with PCOS.

Sex-specific effects of estrogen and androgen on gene expression in human monocyte-derived osteoclasts

Estrogen and androgen are both critical for the maintenance of bone, but the target cells, mechanisms, and responses could be sex-specific. To compare sex-specific actions of estrogen and androgen on osteoclasts, human peripheral blood mononuclear precursor cells from adult Caucasian males (n = 3) and females (n = 3) were differentiated into osteoclasts and then treated for 24 h with 17β-estradiol (10 nM) or testosterone (10 nM). Gene expression was studied with a custom designed qPCR-based array containing 94 target genes related to bone and hormone action. In untreated osteoclasts, 4 genes showed significant gender differences. 17β-estradiol significantly affected 12 genes in osteoclasts from females and 6 genes in osteoclasts from males. Fifteen of the 18 17β-estradiol-responsive genes were different in the cells from the two sexes; 2 genes affected by 17β-estradiol in both sexes were regulated oppositely in the two sexes. Testosterone significantly affected 6 genes in osteoclasts from females and 2 genes in osteoclasts from males; all except one were different in the two sexes. 17β-estradiol and testosterone largely affected different genes, suggesting that conversion of testosterone to 17β-estradiol had a limited role in the responses. The findings indicate that although osteoclasts from both sexes respond to 17β-estradiol and testosterone, the effects of both 17β-estradiol and testosterone differ in the two sexes, highlighting the importance of considering gender in the design of therapy.

Testosterone, endothelial health, and erectile function

Experimental and clinical studies have reported that testosterone has a critical role in the maintenance of homeostatic and morphologic corpus cavernosum components, essential for normal erectile physiology. Although the exact mechanisms mediated by testosterone in erectile function are still under investigation, recent research has suggested an important role in the regulation of endothelial cell (EC) biological functions. Besides stimulating the production of EC mediators, testosterone is also thought to promote the vasculogenic reendothelialization process, mediated by bone marrow-derived endothelial progenitor cells. Additionally, testosterone seems to modulate other erectile tissue components, including trabecular smooth muscle cells, nerve fibers, and tunica albuginea structure, all essential for the erectile process. This paper summarizes current data regarding testosterone-induced cellular and molecular mechanisms that regulate penile tissue components, focusing particularly on the role of testosterone in endothelial health and erectile function.

Role of androgen excess on metabolic aberrations and cardiovascular risk in women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is associated with a clustering of metabolic and cardiovascular risk factors. Insulin resistance is implicated as the major player in the metabolic abnormalities and contributes to the increased cardiovascular risk associated with the syndrome. However, androgen excess appears to participate as an independent parameter, which further aggravates the cardiovascular and metabolic aberrations in affected women with PCOS. The resultant impact of hyperandrogenemia possibly acquires clinical significance for women's health in the context of PCOS, particularly since recent data support an increased incidence of coronary artery disease and of cardiovascular events directly related to androgen levels in women with the syndrome.

Vascular abnormalities and low-grade chronic inflammation in women with polycystic ovary syndrome: Relationships with insulin resistance, obesity and hyperandrogenemia

Polycystic ovary syndrome (PCOS) is possibly the most common endocrinopathy of reproductive age, characterized by hyperandrogenism and oligomenorrhea. Additionally, approximately one-third to one-half of all women and adolescent girls with PCOS tend to fulfill many of the metabolic syndrome criteria, and many view PCOS as a premetabolic syndrome condition, predisposing to a high risk for cardiovascular disease. Endothelial dysfunction, impaired arterial structure, or proinflammatory markers are early features of atherosclerosis, and can be used as surrogate indicators of future coronary artery disease in women with PCOS. However, as the latest studies show, these symptoms are the result of deleterious effects that cardiovascular risk factors, in particular insulin resistance and obesity, produce on the vascular wall, rather than to the presence of PCOS per se. The relationship between hyperandrogenemia and the risk of cardiovascular disease is controversial and needs to be clarified. Further research is warranted to understand the pathogenesis of cardiovascular disease in PCOS, and to identify subtypes of PCOS in which the presence of cardiovascular risk factors may result in increased cardiovascular events, leading to high morbidity or mortality rates caused by cardiovascular disease.

Inflammatory and endothelial markers in women with polycystic ovary syndrome

BACKGROUND

Women with polycystic ovary syndrome (PCOS) carry a pattern of cardiovascular risk factors. Endothelial dysfunction and chronic inflammation are early findings in the atherosclerotic process. The purpose of the study was to investigate the coexistence of active inflammation markers and endothelial dysfunction in young women with PCOS, and their relationship with metabolic and hormonal abnormalities of the syndrome.

MATERIALS AND METHODS

Twenty-five young women with PCOS and 25 controls of similar age and body mass index (BMI) were studied. Endothelial function was assessed by flow-mediated dilatation (FMD) on the brachial artery and smooth muscle cells injury was excluded by nitrate-induced dilatation (NID). Plasma levels of endothelin-1 (ET-1), soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1) and high sensitivity C-reactive protein (hsCRP) were measured. Hormonal and metabolic profiles were determined in both groups.

RESULTS

Flow-mediated dilatation (FMD) was statistically lower in PCOS (P < 0.001), whereas nitrate-induced dilatation (NID) was similar within the two groups. Polycystic ovary syndrome (PCOS) had statistically higher levels of ET-1 (P = 0.03), sICAM-1 (P = 0.01), sVCAM-1 (P = 0.02) and hsCRP (P = 0.01). Furthermore FMD was statistically higher in PCOS population with hsCRP 1 mg L(-1) when compared with PCOS population with hsCRP > 1 mg L(-1) (P = 0.02). Flow-mediated dilatation (FMD) was negatively related to hsCRP (r = -0.512, P = 0.015); ET-1 was positively related to free androgen index (r = 0.27, P = 0.05) and negatively to sex hormone-binding globulin (r = -0.465, P = 0.022); sVCAM-1 was positively related to total testosterone (r = 0.431, P = 0.036); hsCRP was positively related to BMI (r = 0.647, P = 0.001), and negatively related to FMD (r = -0.512, P = 0.015), quantitative insulin sensitivity check index (QUICKI) (r = -0.499, P = 0.018), and MATSUDA index (r = -0.445, P = 0.038).

CONCLUSIONS

The present study demonstrates that endothelial dysfunction coexists and is influenced by the presence of increased serum levels of inflammation and endothelial activation markers in young women with PCOS. These parameters appear to be interrelated with hyperandrogenaemia in this insulin-resistant population.

Periodontal status in men with hypergonadotropic hypogonadism: effects of testosterone deficiency

BACKGROUND

The purpose of this clinical study was to evaluate the possible influence of testosterone hormone on common clinical measurements of periodontal disease in men with hypergonadotropic hypogonadism.

METHODS

Twenty-four hypergonadotropic hypogonadal men (H) and 24 systemically healthy men (S) were divided into two groups as chronic periodontitis and clinically healthy controls after clinical examinations and radiographs. The H group consisted of 12 control (H/C) and 12 chronic periodontitis (H/P) patients, and the S group consisted of 12 control (S/C) and 12 chronic periodontitis (S/P) patients. Plaque index (PI), gingival index (GI), bleeding on probing (BOP), probing depth (PD), and clinical attachment loss (CAL) scores were recorded.

RESULTS

The mean of all clinical parameters (PI, GI, BOP, PD, and CAL) were significantly (P<0.05) higher in periodontitis groups (H/P and S/P) than controls (H/C and S/C). There were no significant differences in the PD and CAL scores between periodontitis groups (S/P and H/P). The mean of GI and BOP scores were statistically higher in the H/P group than the S/P group (P<0.05). There was a negative correlation between GI and free testosterone levels (r=-0.794; P<0.05).

CONCLUSION

According to these results, serum testosterone levels may possibly influence periodontal disease in men, and testosterone may have an inhibitory effect on gingival inflammation.

Sympathoadrenal-dependent sexually dimorphic effect of nonhabituating stress on in vivo neutrophil recruitment in the rat

Since stress both activates the sympathoadrenal axis and profoundly affects inflammation and inflammatory diseases, many of which are sexually dimorphic, we tested whether the effect of stress on neutrophil recruitment, a primary component of the acute inflammatory response, is sexually dimorphic. The effect of intermittent sound (over 4 days), a nonhabituating stress, on lipopolysaccharide (LPS)-induced recruitment of neutrophils was evaluated in vivo in the rat air pouch model. At 24 h following the last stress exposure, LPS-induced neutrophil recruitment was enhanced in male rats, but not in females. When gonadectomized prepubertally and tested as adults, stress significantly inhibited the magnitude of LPS-induced neutrophil recruitment in males, while it still had no effect in gonadectomized females. In males, following adrenal denervation, the increase in LPS-induced neutrophil recruitment produced by stress was prevented. Since these data suggest that the effect of stress is dependent on the sympathoadrenal axis, we tested the hypothesis that catecholamines mediate the stress effects. In male rats, the effect of stress on LPS-induced neutrophil recruitment was significantly attenuated by continuous administration of the beta-adrenergic receptor antagonist, propranolol (4 mg kg(-1) day(-1)), during sound stress exposure, and administration of isoproterenol (10 nmoles, i.v.) significantly increased neutrophil recruitment in males, an effect that was qualitatively and quantitatively similar to the effect of stress. Propranolol significantly increased neutrophil recruitment in nonstressed female rats, but did not significantly affect neutrophil recruitment in stressed females. These findings indicate a marked male sex hormone-dependent sexual dimorphism in the sympathoadrenal-dependent effect of stress on neutrophil migration, a primary component of the inflammatory response, and suggest that the sympathoadrenal axis contributes to this effect via release of epinephrine.