Modulation of neointimal lesion formation by endogenous androgens is independent of vascular androgen receptor

Cardiovascular disease burden in patients with urological cancers: The new discipline of uro-cardio-oncology

Cancer remains a major cause of mortality worldwide, and urological cancers are the most common cancers among men. Several therapeutic agents have been used to treat urological cancer, leading to improved survival for patients. However, this has been accompanied by an increase in the frequency of survivors with cardiovascular complications caused by anticancer medications. Here, we propose the novel discipline of uro-cardio-oncology, an evolving subspecialty focused on the complex interactions between cardiovascular disease and urological cancer. In this comprehensive review, we discuss the various cardiovascular toxicities induced by different classes of antineoplastic agents used to treat urological cancers, including androgen deprivation therapy, vascular endothelial growth factor receptor tyrosine kinase inhibitors, immune checkpoint inhibitors, and chemotherapeutics. In addition, we discuss possible mechanisms underlying the cardiovascular toxicity associated with anticancer therapy and outline strategies for the surveillance, diagnosis, and effective management of cardiovascular complications. Finally, we provide an analysis of future perspectives in this emerging specialty, identifying areas in need of further research.

Sex hormones impact early maturation and immune response in the arteriovenous fistula mouse model

Arteriovenous fistulae (AVF) fail to mature more frequently in female patients compared with male patients, leading to inferior outcomes and decreased utilization. Since our mouse AVF model recapitulates sex differences in human AVF maturation, we hypothesized that sex hormones mediate these differences during AVF maturation. C57BL/6 mice (9-11 wk) were treated with aortocaval AVF surgery and/or gonadectomy. AVF hemodynamics were measured via ultrasound (days 0-21). Blood was collected for FACS and tissue for immunofluorescence and ELISA (days 3 and 7); wall thickness was assessed by histology (day 21). Inferior vena cava shear stress was higher in male mice (P = 0.0028) after gonadectomy, and they had increased wall thickness (22.0 ± 1.8 vs. 12.7 ± 1.2 µm; P < 0.0001). Conversely, female mice had decreased wall thickness (6.8 ± 0.6 vs. 15.3 ± 0.9 µm; P = 0.0002). Intact female mice had higher proportions of circulating CD3+ T cells on day 3 (P = 0.0043), CD4+ (P = 0.0003) and CD8+ T cells (P = 0.005) on day 7, and CD11b+ monocytes on day 3 (P = 0.0046). After gonadectomy, these differences disappeared. In intact female mice, CD3+ T cells (P = 0.025), CD4+ T cells (P = 0.0178), CD8+ T cells (P = 0.0571), and CD68+ macrophages (P = 0.0078) increased in the fistula wall on days 3 and 7. This disappeared after gonadectomy. Furthermore, female mice had higher IL-10 (P = 0.0217) and TNF-α (P = 0.0417) levels in their AVF walls than male mice. Sex hormones mediate AVF maturation, suggesting that hormone receptor signaling may be a target to improve AVF maturation.NEW & NOTEWORTHY After arteriovenous fistula creation, females have lower rates of maturation and higher rates of failure than males. In a mouse model of venous adaptation that recapitulates human fistula maturation, sex hormones may be mechanisms of the sexual dimorphism: testosterone is associated with reduced shear stress, whereas estrogen is associated with increased immune cell recruitment. Modulating sex hormones or downstream effectors suggests sex-specific therapies and could address disparities in sex differences in clinical outcomes.

The Oscillometric Pulse Wave Analysis Is Useful in Evaluating the Arterial Stiffness of Obese Children with Relevant Cardiometabolic Risks

Early detection of all complications of childhood obesity is imperative in order to minimize effects. Obesity causes vascular disruptions, including early increased arterial stiffness and high blood pressure. This study’s aim is to assess the reliability of pulse wave analysis (PWA) in obese children and how additional risk factors influence the evaluated parameters. We analyzed 55 children aged 6–18 years old by measuring their pulse wave velocity (PWV), augmentation index (AIx), peripheral blood pressure (SBP, DBP), heart rate, central blood pressure (cSBP, cDBP) and central pulse pressure (cPP). We used the oscillometric IEM Mobil-O-Graph and performed a single-point brachial measurement. The subjects were divided into two groups: obese (n = 30) and normal-weight (n = 25) and were clinically and anamnestically assessed. BMI and waist circumference are significantly correlated to higher values for PWV, SBP, DBP, cSBP, and cDBP. Weight significantly predicts PWV, SBP, DBP and cPP. The risk factors that significantly influence the PWA and BP values are: a cardiometabolically risky pregnancy (higher PWV, AIx, SBP), active and passive smoking (higher PWV, SBP, cSBP, cDBP), sleep deprivation (higher PWV, SBP, cSBP) and sedentariness (higher PWV, AIx, peripheral and central BP). We conclude that obese children with specific additional cardiometabolic risk factors present increased arterial stiffness and higher blood pressure values.

Enhanced Angiogenesis by 11βHSD1 Blockage Is Insufficient to Improve Reperfusion Following Hindlimb Ischaemia

Background: Critical limb ischaemia (CLI), which is estimated to affect 2 million people in the United States, reduces quality of life, is associated with high morbidity and mortality, and has limited treatment options. Direct stimulation of angiogenesis using proangiogenic growth factors has been investigated as a therapeutic strategy to improve reperfusion in the ischaemic leg. Despite positive outcomes in animal studies, there has been little success in clinical translation. This investigation addressed the hypothesis that angiogenesis could be stimulated indirectly in the ischaemic hindlimb by blocking 11β-hydroxysteroid dehydrogenase 1 (11βHSD1)-mediated reactivation of anti-angiogenic glucocorticoids. Method and Results: Corticosterone suppressed ex vivo angiogenesis in the mouse aortic ring assay. 11βHSD1 deletion (Hsd11b1^Del1/Del1) or pharmacological inhibition (with 300 nM UE2316) which block the reactivation of glucocorticoid (i.e., the conversion of 11-dehydrocorticosterone (11DHC) to bioactive corticosterone) significantly reduced 11DHC-induced suppression of angiogenesis. In a sponge implantation model, 11βHSD1 deletion, but not pharmacological inhibition, enhanced inflammation-induced angiogenesis. By contrast, in the mouse hindlimb ischaemia model, post-ischaemic reperfusion and vascular density were not affected by either deletion or pharmacological inhibition of 11βHSD1 in young or aged mice. 3D vascular imaging suggested that hind limb reperfusion in the 1st week following induction of ischaemia may be driven by the rapid expansion of collateral arteries rather than by angiogenesis. Conclusion: 11βHSD1-mediated glucocorticoid reactivation suppressed angiogenesis ex vivo and in vivo. However, regulation of angiogenesis alone was insufficient to promote reperfusion in hindlimb ischaemia. Future investigation of post-ischaemic reperfusion should include other aspects of systemic vascular remodeling including arteriogenesis and collateral formation.

Endothelial dysfunction after androgen deprivation therapy and the possible underlying mechanisms

INTRODUCTION

Androgen deprivation therapy (ADT) is a key treatment modality in the management of prostate cancer (PCa), especially for patients with metastatic disease. Increasing evidences suggest that patients who received ADT have increased incidence of diabetes, myocardial infarction, stroke, and even mortality. It is important to understand the pathophysiological mechanisms on how ADT increases cardiovascular risk and induces cardiovascular events, which would provide important information for potential implementation of preventive measures.

METHODS

Twenty-six 12-week-old male SD rats were divided into four groups for different types of ADTs including: the bilateral orchidectomy group (Orx), LHRH agonist group (leuprolide), LHRH antagonist group (degarelix), and control group. After treated with drug or adjuvant injection every 3 weeks for 24 weeks, all rats were sacrificed and total blood were collected. Aorta, renal arteries, and kidney were preserved for functional assay, immunohistochemistry, western blot, and quantitative reverse-transcription polymerase chain reaction.

RESULTS

In vascular reactivity assays, aorta, intrarenal, and coronary arteries of all three ADT groups showed endothelial dysfunction. AT1R and related molecules at protein and messenger RNA (mRNA) level were tested, and AT1R pathway was shown to be activated and played a role in endothelial dysfunction. Both ACE and AT1R mRNA levels were doubled in the aorta in the leuprolide group while Orx and degarelix groups showed upregulation of AT1R in the kidney tissues. By immunohistochemistry, our result showed higher expression of AT1R in the intrarenal arteries of leuprolide and degarelix groups. The role of reactive oxygen species in endothelial dysfunction was confirmed by DHE fluorescence, nitrotyrosine overexpression, and upregulation of NOX2 in the different ADT treatment groups.

CONCLUSION

ADT causes endothelial dysfunction in male rats. GnRH receptor agonist compared to GnRH receptor antagonist, showed more impairment of endothelial function in the aorta and intrarenal arteries. Such change might be associated with upregulation and activation of AngII-AT1R-NOX2 induced oxidative stress in the vasculature. These results help to explain the different cardiovascular risks and outcomes related to different modalities of ADT treatment.

Sex moderations in the relationship between aortic stiffness, cognition, and cerebrovascular reactivity in healthy older adults

It is well established that sex differences exist in the manifestation of vascular diseases. Arterial stiffness (AS) has been associated with changes in cerebrovascular reactivity (CVR) and cognitive decline in aging. Specifically, older adults with increased AS show a decline on executive function (EF) tasks. Interestingly, the relationship between AS and CVR is more complex, where some studies show decreased CVR with increased AS, and others demonstrate preserved CVR despite higher AS. Here, we investigated the possible role of sex on these hemodynamic relationships. Acquisitions were completed in 48 older adults. Pseudo-continuous arterial spin labeling (pCASL) data were collected during a hypercapnia challenge. Aortic pulse wave velocity (PWV) data was acquired using cine phase contrast velocity series. Cognitive function was assessed with a comprehensive neuropsychological battery, and a composite score for EF was calculated using four cognitive tests from the neuropsychological battery. A moderation model test revealed that sex moderated the relationship between PWV and CVR and PWV and EF, but not between CVR and EF. Together, our results indicate that the relationships between central stiffness, cerebral hemodynamics and cognition are in part mediated by sex.

Predictive Importance of Blood Pressure Characteristics With Increasing Age in Healthy Men and Women: The MORGAM Project

[Figure: see text].

The Temporal Pattern of Arterial Stiffness during Aging: A Large-Scale Cross-Sectional Study

Brachial-ankle pulse wave velocity (baPWV) is a noninvasive clinical test that provides quantification for the stiffness of both the aorta and peripheral arteries by measuring the brachial and tibial arterial wave velocities. The temporal pattern of baPWV values during aging was investigated in this paper. A gradual increase in baPWV with respect to age was observed, suggesting an increase in the stiffness of arterial vessels as age increases. The ΔbaPWV value, defined as the absolute value of the difference between bilateral baPWV, also showed a positive correlation with aging. Many underlying physiological conditions such as hyperlipidemia, hypertension, diabetes, and hyperglycemia have previously been shown to elevate baPWV and contribute to the decline of arterial function. The effect of factors including biological sex, blood pressure, and blood glucose levels on the baPWV temporal pattern were also investigated. Between the ages of 18 and 50, men in the study had significantly higher baPWV readings than females of comparable age on average. However, after the age of 50, mean baPWV values increased at a greater rate in females than in males. In addition, blood pressure and blood glucose were shown to be associated with baPWV values. The results will improve existing prediction models for future cardiovascular episodes induced by arterial hardening in different age groups.

Approaching Sex Differences in Cardiovascular Non-Coding RNA Research

Cardiovascular disease (CVD) is the biggest cause of sickness and mortality worldwide in both males and females. Clinical statistics demonstrate clear sex differences in risk, prevalence, mortality rates, and response to treatment for different entities of CVD. The reason for this remains poorly understood. Non-coding RNAs (ncRNAs) are emerging as key mediators and biomarkers of CVD. Similarly, current knowledge on differential regulation, expression, and pathology-associated function of ncRNAs between sexes is minimal. Here, we provide a state-of-the-art overview of what is known on sex differences in ncRNA research in CVD as well as discussing the contributing biological factors to this sex dimorphism including genetic and epigenetic factors and sex hormone regulation of transcription. We then focus on the experimental models of CVD and their use in translational ncRNA research in the cardiovascular field. In particular, we want to highlight the importance of considering sex of the cellular and pre-clinical models in clinical studies in ncRNA research and to carefully consider the appropriate experimental models most applicable to human patient populations. Moreover, we aim to identify sex-specific targets for treatment and diagnosis for the biggest socioeconomic health problem globally.

Gonadotropin-releasing hormone agonists, anti-androgens and the risk of cardio-cerebrovascular disease in prostate cancer patients: an asian population-based observational study

Purpose: To conduct a population-based study to determine whether the use of GnRH agonist and antiandrogens are associated with an increased risk of cardio-cerebrovascular disease (CCVD) in Asian patients with prostate cancer using the National Health Insurance Service-Elderly Cohort Database (NHIS-ECD). Materials and Methods: We included a total of 2,413 men aged 60 years or older with prostate cancer between January 2003 and December 2008. Outcomes of interest included the first occurrence of cardiovascular events [acute myocardial infarction (AMI), ischemic heart disease (IHD)] and cerebrovascular events [ischemic stroke (IS), and cerebrovascular disease (CVD)]. Results: The 5-year AMI-free rates of patients diagnosed with prostate cancer and treated with GnRH agonists, antiandrogens alone, or androgen deprivation therapy (ADT)-naïve interventions were 97.0%, 96.5%, and 98.3%, respectively, while the 5-year IHD-free rates were 93.2%, 92.3%, and 94.5%, respectively. Exposure to GnRH agonists or antiandrogen regimens did not significantly increase the risk of AMI or IHD compared to ADT-naïve treatment in multivariate Cox proportional-hazards models after adjusting for other covariates. Five-year IS-free rates of patients exposed to GnRH agonists, antiandrogens alone, and those with ADT-naïve prostate cancer were 94.8%, 94.7%, and 95.5%, respectively, while the five-year CVD-free rates were 92.9%, 93.3%, and 94.6%, respectively. Cox proportional-hazards models also failed to show that men who received GnRH agonist or antiandrogen treatment alone carried a significantly increased risk for IS or CVD compared to ADT-naïve patients. Conclusions: The current study based on Asian population suggests that treatment with neither GnRH agonist nor antiandrogens increases the risk of cardio-cerebrovascular disease compared to patients with ADT-naïve prostate cancer.

Sex differences in mechanisms of arterial stiffness

Arterial stiffness progressively increases with aging and is an independent predictor of cardiovascular disease (CVD) risk. Evidence supports that there are sex differences in the time course of aging-related arterial stiffness and the associated CVD risk, which increases disproportionately in postmenopausal women. The association between arterial stiffness and mortality is almost twofold higher in women versus men. The differential clinical characteristics of the development of arterial stiffness between men and women indicate the involvement of sex-specific mechanisms. This review summarizes the current literature on sex differences in vascular stiffness induced by aging, obesity, hypertension, and sex-specific risk factors as well as the impact of hormonal status, diet, and exercise on vascular stiffness in males and females. An understanding of the mechanisms driving sex differences in vascular stiffness has the potential to identify novel sex-specific therapies to lessen CVD risk, the leading cause of death in males and females. LINKED ARTICLES: This article is part of a themed section on The Importance of Sex Differences in Pharmacology Research. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.21/issuetoc.

Mechanisms of Sex Disparities in Cardiovascular Function and Remodeling

Epidemiological studies demonstrate disparities between men and women in cardiovascular disease prevalence, clinical symptoms, treatments, and outcomes. Enrollment of women in clinical trials is lower than men, and experimental studies investigating molecular mechanisms and efficacy of certain therapeutics in cardiovascular disease have been primarily conducted in male animals. These practices bias data interpretation and limit the implication of research findings in female clinical populations. This review will focus on the biological origins of sex differences in cardiovascular physiology, health, and disease, with an emphasis on the sex hormones, estrogen and testosterone. First, we will briefly discuss epidemiological evidence of sex disparities in cardiovascular disease prevalence and clinical manifestation. Second, we will describe studies suggesting sexual dimorphism in normal cardiovascular function from fetal life to older age. Third, we will summarize and critically discuss the current literature regarding the molecular mechanisms underlying the effects of estrogens and androgens on cardiac and vascular physiology and the contribution of these hormones to sex differences in cardiovascular disease. Fourth, we will present cardiovascular disease risk factors that are positively associated with the female sex, and thus, contributing to increased cardiovascular risk in women. We conclude that inclusion of both men and women in the investigation of the role of estrogens and androgens in cardiovascular physiology will advance our understanding of the mechanisms underlying sex differences in cardiovascular disease. In addition, investigating the role of sex-specific factors in the development of cardiovascular disease will reduce sex and gender disparities in the treatment and diagnosis of cardiovascular disease. © 2019 American Physiological Society. Compr Physiol 9:375-411, 2019.

The role of androgen receptors in atherosclerosis

Male disadvantage in cardiovascular health is well recognised. However, the influence of androgens on atherosclerosis, one of the major causes of many life-threatening cardiovascular events, is not well understood. With the dramatic increase in clinical prescription of testosterone in the past decade, concerns about the cardiovascular side-effects of androgen supplementation or androgen deprivation therapy are increasing. Potential atheroprotective effects of testosterone could be secondary to (aromatase-mediated) conversion into oestradiol or, alternatively, to direct activation of androgen receptors (AR). Recent development of animal models with cell-specific AR knockout has indicated a complex role for androgen action in atherosclerosis. Most studies suggest androgens are atheroprotective but the precise role of AR remains unclear. Increased use of AR knockout models should clarify the role of AR in atherogenesis and, thus, lead to exploitation of this pathway as a therapeutic target.

Increased Intimal Hyperplasia After Vascular Injury in Male Androgen Receptor-Deficient Mice

Intimal hyperplasia is a vascular pathological process involved in the pathogenesis of atherosclerosis. Data suggest that T, the most important sex steroid hormone in males, protects men from atherosclerotic cardiovascular disease. T mainly acts via the androgen receptor (AR), and in this study we evaluated formation of intimal hyperplasia in male AR knockout (ARKO) mice using a vascular injury model. Two weeks after ligation of the carotid artery, male ARKO mice showed increased intimal area and intimal thickness compared with controls. After endothelial denudation by an in vivo scraping injury, there was no difference in the reendothelialization in ARKO compared with control mice. Ex vivo, we observed increased outgrowth of vascular smooth muscle cells from ARKO compared with control aortic tissue explants; the number of outgrown cells was almost doubled in ARKO. In vitro, stimulation of human aortic vascular smooth muscle cells with a physiological T concentration inhibited both migration and proliferation of the cells. Analyzing the expression of central regulators of cell proliferation and migration, we found that mRNA and protein levels of p27 were lower in uninjured arteries from ARKO mice and that T replacement to castrated male mice increased p27 mRNA in an AR-dependent manner. In conclusion, AR deficiency in male mice increases intimal hyperplasia in response to vascular injury, potentially related to the effects of androgens/AR to inhibit proliferation and migration of smooth muscle cells.

Influence of Androgen Receptor in Vascular Cells on Reperfusion following Hindlimb Ischaemia

Aims

Studies in global androgen receptor knockout (G-ARKO) and orchidectomised mice suggest that androgen accelerates reperfusion of the ischaemic hindlimb by stimulating angiogenesis. This investigation used novel, vascular cell-specific ARKO mice to address the hypothesis that the impaired hindlimb reperfusion in G-ARKO mice was due to loss of AR from cells in the vascular wall.

Methods and Results

Mice with selective deletion of AR (ARKO) from vascular smooth muscle cells (SM-ARKO), endothelial cells (VE-ARKO), or both (SM/VE-ARKO) were compared with wild type (WT) controls. Hindlimb ischaemia was induced in these mice by ligation and removal of the femoral artery. Post-operative reperfusion was reduced in SM-ARKO and SM/VE-ARKO mice. Immunohistochemistry indicated that this was accompanied by a reduced density of smooth muscle actin-positive vessels but no change in the density of isolectin B4-positive vessels in the gastrocnemius muscle. Deletion of AR from the endothelium (VE-ARKO) did not alter post-operative reperfusion or vessel density. In an ex vivo (aortic ring culture) model of angiogenesis, AR was not detected in vascular outgrowths and angiogenesis was not altered by vascular ARKO or by exposure to dihydrotestosterone (DHT 10⁻¹⁰–10^-7M; 6 days).

Conclusion

These results suggest that loss of AR from vascular smooth muscle, but not from the endothelium, contributes to impaired reperfusion in the ischaemic hindlimb of G-ARKO. Impaired reperfusion was associated with reduced collateral formation rather than reduced angiogenesis.

Ablation of the androgen receptor from vascular smooth muscle cells demonstrates a role for testosterone in vascular calcification

Vascular calcification powerfully predicts mortality and morbidity from cardiovascular disease. Men have a greater risk of cardiovascular disease, compared to women of a similar age. These gender disparities suggest an influence of sex hormones. Testosterone is the primary and most well-recognised androgen in men. Therefore, we addressed the hypothesis that exogenous androgen treatment induces vascular calcification. Immunohistochemical analysis revealed expression of androgen receptor (AR) in the calcified media of human femoral artery tissue and calcified human valves. Furthermore, in vitro studies revealed increased phosphate (Pi)-induced mouse vascular smooth muscle cell (VSMC) calcification following either testosterone or dihydrotestosterone (DHT) treatment for 9 days. Testosterone and DHT treatment increased tissue non-specific alkaline phosphatase (Alpl) mRNA expression. Testosterone-induced calcification was blunted in VSMC-specific AR-ablated (SM-ARKO) VSMCs compared to WT. Consistent with these data, SM-ARKO VSMCs showed a reduction in Osterix mRNA expression. However, intriguingly, a counter-intuitive increase in Alpl was observed. These novel data demonstrate that androgens play a role in inducing vascular calcification through the AR. Androgen signalling may represent a novel potential therapeutic target for clinical intervention.

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.