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Aims A blood pressure (BP)-independent metabolic shift towards a catabolic state upon high sodium (Na+) diet, ultimately favouring body fluid preservation, has recently been described in pre-clinical controlled settings. We sought to investigate the real-life impact of high Na+ intake on measures of renal Na+/water handling and metabolic signatures, as surrogates for cardiovascular risk, in hypertensive patients. Methods and results We analysed clinical and biochemical data from 766 consecutive patients with essential hypertension, collected at the time of screening for secondary causes. The systematic screening protocol included 24 h urine (24 h-u-) collection on usual diet and avoidance of renin–angiotensin–aldosterone system-confounding medications. Urinary 24 h-Na+ excretion, used to define classes of Na+ intake (low ≤2.3 g/day; medium 2.3–5 g/day; high >5 g/day), was an independent predictor of glomerular filtration rate after correction for age, sex, BP, BMI, aldosterone, and potassium excretion [P = 0.001; low: 94.1 (69.9–118.8) vs. high: 127.5 (108.3–147.8) mL/min/1.73 m2]. Renal Na+ and water handling diverged, with higher fractional excretion of Na+ and lower fractional excretion of water in those with evidence of high Na+ intake [FENa: low 0.39% (0.30–0.47) vs. high 0.81% (0.73–0.98), P, Graphical Abstract

Introduction COVID‐19 is primarily a respiratory disease associated with cardiovascular risk. SARS‐CoV‐2, the virus causing COVID‐19, uses ACE2, an important enzyme in the cardiovascular system that regulates the conversion of Ang II (deleterious/pro‐hypertensive) to Ang 1‐7 (protective/anti‐hypertensive), as a receptor for host cell entry and infection. Considering the relationship between the viral S1‐protein and the host's ACE2, it is unclear whether this interaction is merely a mechanism of infection or whether it also contributes to cardiovascular damage associated with COVID‐19. We hypothesisedthat SARS‐Cov‐2‐ACE2 interaction induces activation of vascular cell inflammatory responses that are influenced by ACE2 dependent and/or independent enzymatic Ang‐(1‐7) production. Methods Human microvascular endothelial cells (MEC) were used and stimulated with SARS‐CoV‐2 recombinant S1 protein (rS1p) (0.66 μg/mL) at 10/30 min (acute) and 5/24h (chronic). Activation of pro‐inflammatory signaling pathways (immunoblotting, real‐time PCR), microparticle (MP) generation (NanoSight), and cytokine production (ELISA) were assessed. In some experiments, cells were pre‐incubated with an ACE2 activator (DIZE – 190 nM) and inhibitor (MLN‐4760 – 440 pM). Results rS1P increased NFκB activation (Control ©=0.99±0.06 vs. 1.38±0.19 AU; p

A link between oxidative stress and hypertension has been firmly established in multiple animal models of hypertension but remains elusive in humans. While initial studies focused on inactivation of nitric oxide by superoxide, our understanding of relevant reactive oxygen species (superoxide, hydrogen peroxide, and peroxynitrite) and how they modify complex signaling pathways to promote hypertension has expanded significantly. In this review, we summarize recent advances in delineating the primary and secondary sources of reactive oxygen species (nicotinamide adenine dinucleotide phosphate oxidases, uncoupled endothelial nitric oxide synthase, endoplasmic reticulum, and mitochondria), the posttranslational oxidative modifications they induce on protein targets important for redox signaling, their interplay with endogenous antioxidant systems, and the role of inflammasome activation and endoplasmic reticular stress in the development of hypertension. We highlight how oxidative stress in different organ systems contributes to hypertension, describe new animal models that have clarified the importance of specific proteins, and discuss clinical studies that shed light on how these processes and pathways are altered in human hypertension. Finally, we focus on the promise of redox proteomics and systems biology to help us fully understand the relationship between ROS and hypertension and their potential for designing and evaluating novel antihypertensive therapies.

The two axes of the renin–angiotensin system include the classical ACE/Ang II/AT1 axis and the counter-regulatory ACE2/Ang-(1-7)/Mas1 axis. ACE2 is a multifunctional monocarboxypeptidase responsible for generating Ang-(1-7) from Ang II. ACE2 is important in the vascular system where it is found in arterial and venous endothelial cells and arterial smooth muscle cells in many vascular beds. Among the best characterized functions of ACE2 is its role in regulating vascular tone. ACE2 through its effector peptide Ang-(1-7) and receptor Mas1 induces vasodilation and attenuates Ang II-induced vasoconstriction. In endothelial cells activation of the ACE2/Ang-(1-7)/Mas1 axis increases production of the vasodilator’s nitric oxide and prostacyclin’s and in vascular smooth muscle cells it inhibits pro-contractile and pro-inflammatory signaling. Endothelial ACE2 is cleaved by proteases, shed into the circulation and measured as soluble ACE2. Plasma ACE2 activity is increased in cardiovascular disease and may have prognostic significance in disease severity. In addition to its enzymatic function, ACE2 is the receptor for severe acute respiratory syndrome (SARS)-coronavirus (CoV) and SARS-Cov-2, which cause SARS and coronavirus disease-19 (COVID-19) respectively. ACE-2 is thus a double-edged sword: it promotes cardiovascular health while also facilitating the devastations caused by coronaviruses. COVID-19 is associated with cardiovascular disease as a risk factor and as a complication. Mechanisms linking COVID-19 and cardiovascular disease are unclear, but vascular ACE2 may be important. This review focuses on the vascular biology and (patho)physiology of ACE2 in cardiovascular health and disease and briefly discusses the role of vascular ACE2 as a potential mediator of vascular injury in COVID-19.

SARS-CoV-2 viral attachment and entry into host cells is mediated by a direct interaction between viral spike glycoproteins and membrane bound angiotensin-converting enzyme 2 (ACE2). The receptor binding motif (RBM), located within the S1 subunit of the spike protein, incorporates the majority of known ACE2 contact residues responsible for high affinity binding and associated virulence. Observation of existing crystal structures of the SARS-CoV-2 receptor binding domain (SRBD)–ACE2 interface, combined with peptide array screening, allowed us to define a series of linear native RBM-derived peptides that were selected as potential antiviral decoy sequences with the aim of directly binding ACE2 and attenuating viral cell entry. RBM1 (16mer): S443KVGGNYNYLYRLFRK458, RBM2A (25mer): E484GFNCYFPLQSYGFQPTNGVGYQPY508, RBM2B (20mer): F456NCYFPLQSYGFQPTNGVGY505 and RBM2A-Sc (25mer): NYGLQGSPFGYQETPYPFCNFVQYG. Data from fluorescence polarisation experiments suggested direct binding between RBM peptides and ACE2, with binding affinities ranging from the high nM to low μM range (Kd = 0.207–1.206 μM). However, the RBM peptides demonstrated only modest effects in preventing SRBD internalisation and showed no antiviral activity in a spike protein trimer neutralisation assay. The RBM peptides also failed to suppress S1-protein mediated inflammation in an endogenously expressing ACE2 human cell line. We conclude that linear native RBM-derived peptides are unable to outcompete viral spike protein for binding to ACE2 and therefore represent a suboptimal approach to inhibiting SARS-CoV-2 viral cell entry. These findings reinforce the notion that larger biologics (such as soluble ACE2, ‘miniproteins’, nanobodies and antibodies) are likely better suited as SARS-CoV-2 cell-entry inhibitors than short-sequence linear peptides.

The development of novel, non-invasive techniques and standardization of protocols to assess microvascular dysfunction have elucidated the key role of microvascular changes in the evolution of cardiovascular (CV) damage, and their capacity to predict an increased risk of adverse events. These technical advances parallel with the development of novel biological assays that enabled the ex vivo identification of pathways promoting microvascular dysfunction, providing novel potential treatment targets for preventing cerebral-CV disease. In this article, we provide an update of diagnostic testing strategies to detect and characterize microvascular dysfunction and suggestions on how to standardize and maximize the information obtained from each microvascular assay. We examine emerging data highlighting the significance of microvascular dysfunction in the development CV disease manifestations. Finally, we summarize the pathophysiology of microvascular dysfunction emphasizing the role of oxidative stress and its regulation by epigenetic mechanisms, which might represent potential targets for novel interventions beyond conventional approaches, representing a new frontier in CV disease reduction., Graphical Abstract

Vascular smooth muscle cell (VSMC) function is regulated by Nox-derived reactive oxygen species (ROS) and redox-dependent signaling in discrete cellular compartments. Whether cholesterol-rich microdomains (lipid rafts/caveolae) are involved in these processes is unclear. Here we examined the sub-cellular compartmentalization of Nox isoforms in lipid rafts/caveolae and assessed the role of these microdomains in VSMC ROS production and pro-contractile and growth signaling. Intact small arteries and primary VSMCs from humans were studied. Vessels from Cav-1−/− mice were used to test proof of concept. Human VSMCs express Nox1, Nox4, Nox5 and Cav-1. Cell fractionation studies showed that Nox1 and Nox5 but not Nox4, localize in cholesterol-rich fractions in VSMCs. Angiotensin II (Ang II) stimulation induced trafficking into and out of lipid rafts/caveolae for Nox1 and Nox5 respectively. Co-immunoprecipitation studies showed interactions between Cav-1/Nox1 but not Cav-1/Nox5. Lipid raft/caveolae disruptors (methyl-β-cyclodextrin (MCD) and Nystatin) and Ang II stimulation variably increased O2− generation and phosphorylation of MLC20, Ezrin-Radixin-Moesin (ERM) and p53 but not ERK1/2, effects recapitulated in Cav-1 silenced (siRNA) VSMCs. Nox inhibition prevented Ang II-induced phosphorylation of signaling molecules, specifically, ERK1/2 phosphorylation was attenuated by mellitin (Nox5 inhibitor) and Nox5 siRNA, while p53 phosphorylation was inhibited by NoxA1ds (Nox1 inhibitor). Ang II increased oxidation of DJ1, dual anti-oxidant and signaling molecule, through lipid raft/caveolae-dependent processes. Vessels from Cav-1−/− mice exhibited increased O2− generation and phosphorylation of ERM. We identify an important role for lipid rafts/caveolae that act as signaling platforms for Nox1 and Nox5 but not Nox4, in human VSMCs. Disruption of these microdomains promotes oxidative stress and Nox isoform-specific redox signalling important in vascular dysfunction associated with cardiovascular diseases.

Mas and ET B receptors physically interact in endothelial cells (ECs) and are involved in the protective actions of angiotensin 1-7 (Ang (1-7)). We assessed whether the MAS/ET B R interaction plays a role in EC signalling and whether strategies to enhance MAS/ET B R association influence vascular responses. Human ECs were stimulated with Ang (1-7) (10 -7 M) in the presence/absence of A779 (Mas receptor antagonist, 10 -5 M) and BQ788 (ET B R antagonist, 10 -5 M). Protein expression and signalling activation were assessed by immunoblotting. NO production was evaluated by DAF-FM fluorescence and ROS production by chemiluminescence (superoxide anion) or amplex red (hydrogen peroxide (H 2 O 2 )). mRNA expression was assessed by qPCR. Endothelial function was assessed in mouse intact arteries by myography. Ang (1-7), through Mas and ET B R induced phosphorylation of eNOS (35%); followed by an increase in NO production (2.0 fold) (pB R interaction. Fluorescence polarization assays were used to further select the most potent enhancers and define their working concentration for testing in ECs (Enh1-4: 10 -5 M). Enh4 increased superoxide anion (55.6±26.3% vs ctl, p2 O 2 production (54.7±11.1% vs ctl, p2 O 2 generation (48.1±15.4% vs ctl, pNrf2 (3.0 fold), Sod1 (2.0 fold) and Nqo1 (3.1 fold) mRNA expression (pB R interaction with specific enhancers augments protective signalling in ECs and promotes endothelial-dependent vasorelaxation, particularly with Enh4. In conclusion, enhancing interactions between MasR and ET B R may be a new vasoprotective strategy to improve vascular function in cardiovascular disease.

Magnesium regulates numerous cellular functions and enzymes and abnormal magnesium homeostasis contributes to vascular dysfunction and the development of hypertension. The transient receptor potential melastatin 7 (TrpM7) has emerged as a key player in cardiovascular magnesium homeostasis. This bifunctional channel/kinase is ubiquitously expressed and regulates embryonic development. Its integral membrane ion channel domain regulates transmembrane movement of divalent cations, primarily Ca 2+ , Mg 2+ and Zn 2+ , and its kinase domain controls gene expression via histone phosphorylation. TrpM7 not only localizes on the cell surface to serve as a critical regulator of transmembrane Mg 2+ flux, but also forms an intracellular Zn 2+ release channel in vesicles of unknown origin. Palmitoylation is a dynamic reversible posttranslational modification, which regulates ion channel activity, stability, and subcellular localization. We found that TrpM7 is palmitoylated in multiple cell types. Here we sought to identify palmitoylated cysteines and the functional consequences of TrpM7 palmitoylation in HEK cells. Mutation of Cysteines 1143, 1144 and 1146 on TrpM7 (TrpM7-AAA) to alanines reduced its palmitoylation by 68.4±8% (n=13; P P P P P

Epidermal growth factor (EGF), signals throught the EGF receptor (EGFR) and plays an important role in the pathogenesis of vascular remodeling. Transient receptor potential melastatin 7 (TRPM7) is a channel bound to a kinase domain important for Mg 2+ , Zn 2+ and Ca 2+ homeostasis. Cancer patients treated with EGFR inhibitors develop hypomagnesemia, suggesting a relationship between EGFR and TRPM7. Here we investigated the role of TRPM7 in EGF signaling in vascular smooth muscle cell (VSMC) from humans (hVSMC) and rats (rVSMC). VSMCs were stimulated with EGF (50ng/ml) for 5min and 24h with/without pretreatment of gefitinib (1μM), PP2 (10μM), 2APB (30μM) and NS8593 (40μM), inhibitors of EGFR, c-Src kinase and TRPM7 respectively. Aortas were isolated from wild type (WT), TRPM7-deficient (TRPM7 +/Δkinase ) and kinase-dead (TRPM7 R/R ) mice. Protein expression was assessed by immunoblotting. Ca 2+ and Mg 2+ were assessed using Cal-520 and Mg-green probes respectively. EGFR/TRPM7 interaction was investigated by proximity ligation assay (PLA), immunoprecipitation and confocal microscopy. VSMC migration and proliferation were examined by wound healing and CFSE proliferation assays. In hVSMC and rVSMC, EGF increased TRPM7 expression (47%) and phosphorylation (21%), (p2+ and Ca 2+ influx was attenuated by gefitinib (4% and 8% respectively), NS8593 (5% for Mg 2+ ) and 2-APB (6% and 13% respectively). EGF enhanced ERK1/2 phosphorylation (3-fold) through c-Src, EGFR and TRPM7, p+/Δkinase showed reduced EGFR expression (73%), phospho-c-Src (22%), and phospho-ERK1/2 (90%). Aortas from TRPM7 R/R exhibited reduced phospho-EGFR (63%) and phospho-ERK1/2 (36%). Vessels from TRPM7 +/Δkinase showed reduced wall thickness (35%). Our findings demonstrate that interaction between EGFR/TRPM7 is a key process underlying EGF-induced VSMC migration and growth. This novel EGF-c-Src-EGFR-TRPM7 pathway may play an important role in vascular remodeling.

Although studies demonstrate an important role for fetuin-A (FetA) in the inhibition of vascular calcification, convincing evidence suggests that fetuin-A is also involved in insulin resistance, inflammation and cardiovascular damage. The present study seeks to unravel FetA vascular effects and associated molecular mechanisms, focusing on oxidative stress and toll-like receptor 4 (TLR4). Vascular function studies were performed in mesenteric resistance arteries from WKY rats, wild-type, Nox1 KO, Nox4 KO and Ang II-dependent hypertensive mice (LinA3) and rat aortic endothelial cells (RAEC). ROS production (chemiluminescence, Amplex Red, ELISA) and pro-inflammatory markers expression (RT-PCR) were measured in VSMCs from WKY rats and RAEC. FetA impaired endothelium-dependent (LogEC50 7.320±0.08 M vs control 8.025±0.06) and endothelium-independent vasorelaxation (LogEC50 6.48±0.19 M vs control 7.38±0.12), p

Numerous molecular mechanisms have been implicated in processes underlying vascular phenotypic changes and alterations in hypertension, including microRNAs (miRNAs), oxidative stress and perturbed endoplasmic reticulum (ER) function. The interplay between these elements is unclear. We assessed the VSMC miRNAs profile in hypertension focusing on oxidative and ER stress pathways. VSMCs from small arteries from normotensive (NT) and hypertensive (HT) subjects were used. miRNA profiling of 758 miRNAs was performed using TaqMan advanced miRNA assay (TaqMan Low Density Array Human microRNA). Ingenuity Pathway Analysis (IPA) was used for miRNA target prediction. Expression of vascular genes and proteins was detected by RT-PCR and immunoblotting. ROS generation (chemiluminescence) was assessed in the absence and presence of ER stress inducer tunicamycin (5μg/ml, 24h). miRNA array identified 25 miRNAs uniquely expressed in HT and 21 miRNAs uniquely expressed in NT (CT1.5), while 136 miRNAs were significantly downregulated in HT (fold change >1.5). miRNAs that were altered in hypertension, targeted genes involved in oxidative and ER stress. Pro-oxidant [Nox1 mRNA (1.71 fold), Nox4 (1.59 fold), Nox5 (2.04 fold)] and antioxidant [SOD2 mRNA (4.43 fold), GPx1 (1.97 fold)] enzymes protein levels upregulated in HT (p

TRPM7 has cation channel and kinase properties, is permeable to Mg 2+ , Ca 2+ , and Zn 2+ and is protective in the cardiovascular system. Hyperaldosteronism, which induces hypertension and cardiovascular fibrosis, is associated with Mg 2+ wasting. Here we questioned whether TRPM7 plays a role in aldosterone- induced hypertension and fibrosis and whether it influences cation regulation. Wild-type (WT) and TRPM7-deficient (M7+/Δ) mice were treated with aldosterone (600μg/Kg/day) and/or 1% NaCl (drinking water) (aldo, salt or aldo-salt) for 4 weeks. Blood pressure (BP) was evaluated by tail-cuff. Vessel structure was assessed by pressure myography. Molecular mechanisms were investigated in cardiac fibroblasts (CF) from WT and M7+/Δ mice. Protein expression was assessed by western-blot and histology. M7+/Δ mice exhibited reduced TRPM7 expression (30%) and phosphorylation (62%), levels that were recapitulated in WT aldo-salt mice. M7+/Δ exhibited increased BP by aldo, salt and aldo-salt (135-140mmHg) vs M7+/Δ-veh (117mmHg) (p2+ -dependent phosphatase, was reduced (3-fold) only in M7+/Δ mice. M7+/Δ CF showed reduced proliferation (30%) and PPM1A (4-fold) and increased expression of TGFβ, IL-11 and IL-6 (2-3-fold), activation of Stat1 (2-fold), Smad3 (9-fold) and ERK1/2 (8-fold) compared with WT. Mg 2+ supplementation normalized cell proliferation and reduced protein phosphorylation in M7+/Δ CF (p2+ -dependent mechanisms.

CADASIL, a monogenic condition due to Notch3 mutations, is a very aggressive small vessel disease of the brain resulting in premature vascular dementia and stroke. Changes in cerebral vessels include vascular dysfunction and narrowing, and accumulation of granular osmiophilic material (GOM). It is not clear whether small peripheral arteries undergo similar damage. Therefore, our aim is to assess vascular dysfunction and associated mechanisms in mesenteric resistance arteries from CADASIL mice. Mesenteric arteries (MA) from male CADASIL-causing Notch3 mutation (TgNotch3 R169C ) and wildtype (TgNotch3 WT ) mice (6 months old) were investigated. GOM deposits in MA from CADASIL mice were identified by electron microscopy. mRNA expression of Notch3 (WT: 2.0±0.5 vs. 6.0±1.3) and its downstream target HeyL (WT: 1.1±0.4 vs. 2.9±0.6) was augmented in CADASIL mice (p2 7.8±0.1 vs. 6.8±0.3); effects associated with increased eNOS inhibition (p-Thr 495 ) (1.8-fold increase) and decreased cGMP levels (1.2±0.2 vs. 0.59±0.2) (pR169C mice; processes associated with upregulation of soluble guanylate cyclase (sGC) oxidation and decreased sGC activity. H 2 O 2 levels were decreased in TgNotch3 R169C mice (1.9±0.2 vs. 1.1±1.9; pR169C mice were recapitulated in human CADASIL, where ROS levels (0.8±0.1 vs. 4.1±2.7; p

NOX4-induced H 2 O 2 production promotes vasodilation and is cardiovascular protective. H 2 O 2 also regulates TRPM2, a redox-sensitive channel that regulates Ca 2 influx. eNOS is a Ca 2+ -dependent enzyme, and hypertension-associated endothelial dysfunction involves eNOS inactivation. As NOX4-derived H 2 O 2 regulates TRPM2 and consequently Ca 2+ influx, we questioned whether downregulation of the H 2 O 2 -TRPM2-Ca 2+ axis in endothelial cells may contributes to impaired vascular relaxation in hypertension. WT and TTRhRen hypertensive mice were crossed with Nox4 KO mice. Vascular function was studied in mesenteric resistance arteries by wire myography. Ca 2+ influx was assessed by fluorescence microscopy in aortic endothelial cells, eNOS activation and TRPM2 expression were assessed by immunoblotting and immunohistochemistry, respectively. Blood pressure in TTRhRen (130.3±7.0 mmHg) and TTRhRen/NOX4 KO mice (141.3±18 mmHg) was significantly increased compared to control mice (98.1±8.0 mmHg). Endothelium-dependent relaxation was impaired in TTRhRen mice (Emax: WT 83.5±4.03 vs TTRhRen 59.1±3.5), effects worsened by NOX4 KO (37.9±5.4), p2 O 2 incubation (74.2±15.4), p2 O 2 generation (% of control: 138.23±9.04) followed by Ca 2+ influx (AUC - Ca 2+ : 19401.25±1940.21), an important regulator of eNOS. These processes were reduced by TRPM2 inhibition (AUC - Ca 2+ : 8-br-cADPR 15232.2±1052.0; Olaparib 14260±843.2 and 2-APB 13095.2±277.4, p2+ : Ang II 107357±1940.2 vs GKT 15067.5±255.6, p2 O 2 due to Nox4 downregulation is a major driver of this process. We identify a new axis in endothelial cells involving Nox4-H 2 O 2 -mediated activation of TRPM2-Ca 2+ -eNOS signalling which is vasoprotective.

Nox5 is the major ROS-generating Nox isoform in human vascular smooth muscle cells (VSMC). The role of Nox5 in oxidative stress and redox signaling underlying vascular dysfunction in hypertension is unclear. We examined molecular processes that regulate VSMC Nox5-induced ROS generation, focusing on c-Src. VSMC isolated from small arteries from normotensive (NT) and hypertensive (HT) subjects were studied. Nox5 expression and phosphorylation (immunoblotting, immunoprecipitation); ROS generation (chemiluminescence); activation of contractile signaling pathways (immunoblotting), Ca 2+ influx (Cal-520AM fluorescence), reversible protein oxidation (cysteine sulfenic acid probe BCN-E-BCN), actin polymerization (phalloidin staining) and migration (wound healing assay) were assessed in absence/presence of Nox5 (melittin) and Src (PP2) inhibitors. To study Nox5-specific effects, we used p22phox-silenced VSMCs (siRNA). Vascular function in VSMC-specific Nox5 transgenic mice was studied by wire myography. In HT, ROS levels (139±27%), Nox5 expression (103±23%) and phosphorylation were increased (77±17.93%) (p20 (416±71%) and Ang II-induced Ca 2+ influx (574±44 vs NT:451±26) were also increased in HT (p20 (89±22% vs Ctl) phosphorylation, effects blocked by melittin and PP2 (p2+ influx, actin polymerization and migration in HT. Hypercontractility observed in Nox5 mice was abolished by melittin and PP2. Our findings demonstrate that Nox5 is upregulated in human hypertension. This is associated with activation of c-Src, increased redox signaling and VSMC cytoskeletal reorganization, migration and vascular contraction. We define a novel Nox5-ROS-c-Src signaling pathway that may play a role in vascular remodeling/dysfunction in hypertension.

Our understanding of Na+ homeostasis has recently been reshaped by the notion of skin as a depot for Na+ accumulation in multiple cardiovascular diseases and risk factors. The proposed water-independent nature of tissue Na+ could induce local pathogenic changes, but lacks firm demonstration. Here, we show that tissue Na+ excess upon high Na+ intake is a systemic, rather than skin-specific, phenomenon reflecting architectural changes, i.e. a shift in the extracellular-to-intracellular compartments, due to a reduction of the intracellular or accumulation of water-paralleled Na+ in the extracellular space. We also demonstrate that this accumulation is unlikely to justify the observed development of experimental hypertension if it were water-independent. Finally, we show that this isotonic skin Na+ excess, reflecting subclinical oedema, occurs in hypertensive patients and in association with aging. The implications of our findings, questioning previous assumptions but also reinforcing the importance of tissue Na+ excess, are both mechanistic and clinical., Na+ has been suggested to accumulate in tissues, particularly skin, in a hypertonic manner and to exert local pathogenic effects. Here, we reappraise this phenomenon which is systemic in nature and reflects isotonic changes in the relative extracellular volume in tissues, e.g. subclinical oedema; as such, it occurs in human hypertension and aging.

NOX5 (NADPH oxidase 5) is a homolog of the gp91

The etiology of hypertension involves complex interactions among genetic, environmental, and pathophysiologic factors that influence many regulatory systems. Hypertension is characteristically associated with vascular dysfunction, cardiovascular remodelling, renal dysfunction, and stimulation of the sympathetic nervous system. Emerging evidence indicates that the immune system is also important and that activated immune cells migrate and accumulate in tissues promoting inflammation, fibrosis, and target-organ damage. Common to these processes is oxidative stress, defined as an imbalance between oxidants and antioxidants in favour of the oxidants that leads to a disruption of oxidation-reduction (redox) signalling and control and molecular damage. Physiologically, reactive oxygen species (ROS) act as signalling molecules and influence cell function through highly regulated redox-sensitive signal transduction. In hypertension, oxidative stress promotes posttranslational modification (oxidation and phosphorylation) of proteins and aberrant signalling with consequent cell and tissue damage. Many enzymatic systems generate ROS, but NADPH oxidases (Nox) are the major sources in cells of the heart, vessels, kidneys, and immune system. Expression and activity of Nox are increased in hypertension and are the major systems responsible for oxidative stress in cardiovascular disease. Here we provide a unifying concept where oxidative stress is a common mediator underlying pathophysiologic processes in hypertension. We focus on some novel concepts whereby ROS influence vascular function, aldosterone/mineralocorticoid actions, and immunoinflammation, all important processes contributing to the development of hypertension.

Background: Sex hormones influence vascular function. Whether boys with hypospadias who have insufficient androgen exposure during the masculinisation programming window have altered vascular function is unknown. Objective: To investigate whether vascular function is impaired in boys with hypospadias and to explore the putative role of eNOS. Methods: Peripheral arteries from excess foreskin tissue obtained from boys undergoing hypospadias repair (cases) or circumcision (controls) were used. Vascular function was assessed by myography. mRNA expression was measured by qPCR in vascular smooth muscle cells (VSMCs). Nitric oxide (NO) was measured by DAF fluorescence assay and peroxynitrite levels measured via ELISA. Results: 23 boys with hypospadias and 34 age-matched controls were studied. There were 18 (52%) cases of distal, 7 (22%) of midshaft and 9 (26%) of proximal hypospadias and none of them had biochemical evidence of hypogonadism or a variant in AR. Clinical cardiometabolic parameters were similar between groups. Endothelium-dependent relaxation to acetylcholine (ACh) and endothelium-independent relaxation to sodium nitroprusside (SNP) were reduced in arteries from cases vs controls (Emax %U46619: 72.4 vs 1.2, p

Objective Our traditionally nephrocentric view of Na+ homeostasis has recently been challenged by the concept of Na+ accumulation in tissues, predominantly skin, observed in hypertension. Its proposed water-independent (hypertonic) nature, carrying pathogenic potential, lacks firm demonstration. This study investigates the nature and clinical correlates of skin Na+ accumulation in hypertensive patients. Design and Method Responses to a validated salt intake questionnaire, measures of transepidermal water loss (TEWL), blood samples and a skin punch biopsy were collected from adult, non-pregnant and consenting hypertensive patients at the Glasgow Blood Pressure Clinic. Histochemical analysis was conducted by splitting the skin into epidermis/superficial dermis (ESD) and deep dermis (DD) layers. Water was measured by gravimetric approach (wet weight – dry weight), and Na+ and K+ by flame photometry. Results Seventy-six patients consented to skin biopsy (age: 58±15, range 22–86 years; females = 47.4%; BMI: 30.3, IQR 27.5–36.3). Na+ concentration ([Na+]) and K+ concentration ([K+]) was lower and higher in ESD (richer in cellularity) compared to DD, respectively (112.6±8.57 and 30.17±4.88 vs 119.0±11.81 and 17.28±3.62 mmol/l), respectively (p Conclusions Skin Na+ accumulation in hypertensive patients is isotonic, prevalent and reflects subclinical oedema. Tissue architecture considerably impacts on Na+ content and concentration, whereas TEWL has minimal effect. These results have mechanistic, diagnostic and therapeutic implications.

Introduction: Abnormal development of the genital tract during the first trimester can lead to hypospadias. This stage coincides with the programming window during which androgens are required for normal masculinisation of the genital tract. Since fetal development may also be associated with long-term effects on cardiometabolic outcome and testosterone is itself an important vascular hormone, we questioned whether adults with a history of hypospadias are at increased risk of long-term cardiovascular and metabolic disease. Aim: This retrospective study determined if hypospadias is associated with increased risk of cardiometabolic disease later in life. Methods: Cardiovascular and diabetes admissions data were extracted through record linkage for all males with a history of hypospadias (ICD10 Q54) from 1981 to 2019 through the NHS Scotland Information Services Division after ethics approval. Controls were matched for age, birthweight, gestation and deprivation index. Incident admissions for angina, arrhythmia, diabetes, heart failure, ischaemic heart disease, myocardial infarction, peripheral arterial disease, renal failure and stroke were obtained for each individual. Case control analysis was performed using Chi square test using R. Results: Admission data on 13,481 men with hypospadias and 9,615 matched controls were reviewed. Men with hypospadias had a 10- fold higher risk of diabetes (9.7 [8.4-11.2], p

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) leads to premature stroke and vascular dementia. Mechanism-specific therapies for this aggressive cerebral small vessel disease are lacking. CADASIL is caused by NOTCH3 mutations that influence vascular smooth muscle cell (VSMC) function through unknown processes. We investigated molecular mechanisms underlying the vasculopathy in CADASIL focusing on endoplasmic reticulum (ER) stress and RhoA/Rho kinase (ROCK). Peripheral small arteries and VSMCs were isolated from gluteal biopsies of CADASIL patients and mesentery of TgNotch3R169C mice (CADASIL model). CADASIL vessels exhibited impaired vasorelaxation, blunted vasoconstriction, and hypertrophic remodeling. Expression of NOTCH3 and ER stress target genes was amplified and ER stress response, Rho kinase activity, superoxide production, and cytoskeleton-associated protein phosphorylation were increased in CADASIL, processes associated with Nox5 upregulation. Aberrant vascular responses and signaling in CADASIL were ameliorated by inhibitors of Notch3 (γ-secretase inhibitor), Nox5 (mellitin), ER stress (4-phenylbutyric acid), and ROCK (fasudil). Observations in human CADASIL were recapitulated in TgNotch3R169C mice. These findings indicate that vascular dysfunction in CADASIL involves ER stress/ROCK interplay driven by Notch3-induced Nox5 activation and that NOTCH3 mutation–associated vascular pathology, typical in cerebral vessels, also manifests peripherally. We define Notch3-Nox5/ER stress/ROCK signaling as a putative mechanism-specific target and suggest that peripheral artery responses may be an accessible biomarker in CADASIL., ER stress and Rho kinase are potentially druggable targets in CADASIL, the most aggressive form of small vessel disease and dementia.

Background and Purpose: Inflammation plays a key role in atherosclerosis. The protective role of angiotensin 1–7 (Ang-(1–7)) in vascular pathologies suggested the therapeutic use of low MW, non-peptide Ang-(1–7) mimetics, such as AVE0991. The mechanisms underlying the vaso-protective effects of AVE0991, a Mas receptor agonist, remain to be explored. Experimental Approach: We investigated the effects of AVE0991 on the spontaneous atherosclerosis in apolipoprotein E (ApoE)−/− mice, in the context of vascular inflammation and plaque stability. Key Results: AVE0991 has significant anti-atherosclerotic properties in ApoE−/− mice and increases plaque stability, by reducing plaque macrophage content, without effects on collagen. Using the descending aorta of chow-fed ApoE−/− mice, before significant atherosclerotic plaque develops, we gained insight to early events in atherosclerosis. Interestingly, perivascular adipose tissue (PVAT) and adventitial infiltration with macrophages and T-cells precedes atherosclerotic plaque or the impairment of endothelium-dependent NO bioavailability (a measure of endothelial function). AVE0991 inhibited perivascular inflammation, by reducing chemokine expression in PVAT and through direct actions on monocytes/macrophages inhibiting their activation, characterized by production of IL-1β, TNF-α, CCL2 and CXCL10, and differentiation to M1 phenotype. Pretreatment with AVE0991 inhibited migration of THP-1 monocytes towards supernatants of activated adipocytes (SW872). Mas receptors were expressed in PVAT and in THP-1 cells in vitro, and the anti-inflammatory effects of AVE0991 were partly Mas dependent. Conclusions and Implications: The selective Mas receptor agonist AVE0991 exhibited anti-atherosclerotic and anti-inflammatory actions, affecting monocyte/macrophage differentiation and recruitment to the perivascular space during early stages of atherosclerosis in ApoE−/− mice. Linked Articles: This article is part of a themed section on Targeting Inflammation to Reduce Cardiovascular Disease Risk. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.22/issuetoc and http://onlinelibrary.wiley.com/doi/10.1111/bcp.v82.4/issuetoc

Hypospadias is usually associated with androgen insufficiency. As androgens regulate Ca 2+ influx, Nox activity and redox signalling, we sought to ascertain where these may be implicated in vascular dysfunction seen in boys with hypospadias. Peripheral arteries dissected from excess foreskin tissue from hypospadias (cases) or circumcision (controls) were used. Vascular function was assessed by wire myography.VSMCs were cultured and ROS production was measured by amplex red and chemiluminescence. mRNA expression was measured by qPCR and Ca 2+ influx by fluorescence microscopy. 20 boys with hypospadias and 29 age-matched controls were enrolled in this study (median age 1.9 (range 1.3, 12.2) years). Arteries from cases demonstrated increased constriction to U46619 vs controls (Emax %KCl: 175.6 vs 66.3 p2 0 2 (3.3 fold) levels were increased in cases compared to controls (pAR and GPRC6A) between cases and controls but cases had higher expression of the oestrogen receptors, ESR1 (2.7 fold), ESR2 (2.6 fold) and GPR30 (2.9 fold) (p2+ influx between controls and boys with hypospadias.Testosterone and oestradiol stimulation reduced expression of Ca 2+ channels (p2+ influx in boys with hypospadias. Vascular dysfunction observed in small arteries from boys with hypospadias may be due to Nox5 activation and altered Ca 2+ regulation. These data suggest a role for androgens in the regulation of vascular Nox5-Ca 2+ signaling, which when perturbed may predispose to cardiovascular risk.

CADASIL, a monogenic condition due to Notch3 mutations is a small vessel disease of the brain resulting in premature vascular dementia and stroke. CADASIL patients have cerebral vascular narrowing, progressive SMCs loss and granular osmiophilic material (GOM) deposition, however it is unclear whether peripheral arteries also exhibit dysfunction. We studied mice harbouring the CADASIL-causing Notch3 mutation (TgNotch3 R169C ), which recapitulates human CADASIL, to evaluate whether peripheral small arteries exhibit vascular dysfunction. Mesenteric arteries (MA) from male TgNotch3 R169C and wildtype (TgNotch3 WT ) mice (6 months old) were investigated. Vascular structure and function were assessed by myography. No changes were observed in blood pressure and cardiac function in CADASIL mice, measured by tail cuff and echocardiography respectively. Expression of Notch3 and target genes was augmented in MA from CADASIL mice ( Notch3 : 2.0±0.5 vs. 6.0±1.3; HeyL: 1.1±0.4 vs. 2.9±0.6, p2 7.8±0.1 vs 6.8±0.3) relaxation and increased reactivity in response to AngII (Emax 33.7±6.8 vs. 72.8±4.4), phenylephrine (Emax: 70.6±7.2 vs. 92.1±4.2), and U46619 (Emax: 123.4±4.4 vs. 215.1±24.4) (pWT ); effects attenuated by fasudil (Rho-kinase inhibitor) and 4-PBA (ER stress inhibitor) (pR169C ). MA from CADASIL mice also had hypotrophic remodelling. U46619-induced calcium influx was increased in VSMCs (AUC: 1.3 fold increase) from TgNotch3 R169C and gene expression of Rho GEFs (LARG: 1.1±0.1 vs. 2.1±0.3; PDZ: 0.9±0.1 vs. 2.9±0.4) was increased in MA from TgNotch3 R169C vs. TgNotch3 WT mice (p495 ) and BiP expression (ER stress marker) were increased in vessels from CADASIL mice (eNOS: 1.8 fold increase; Bip: 1.7 fold increase; pWT ). In conclusion, our data demonstrated that the vasculopathy associated with Notch3 mutation is also present in peripheral small vessels where the interplay between Notch3, Rho-kinase and ER stress may be important. We identify potential new therapeutic targets in CADASIL, for which there are no disease-specific treatments.

Patients with coronary microvascular dysfunction (CMD), a potential cause of heart ischemia, have systemic vascular dysfunction, characterized by increased vascular contraction to ET-1 and a thromboxane A2 analogue (U46619). Nox5 regulates vascular contraction and is involved in cardiovascular diseases. In our study, we questioned whether Nox5 plays a role in systemic vascular dysfunction in heart ischemia. As Nox5 expression has been described in the cardiovascular system of rabbits, a model of ischaemic cardiomyopathy (IC) was used. Coronary artery ligation was performed in Male New Zealand White rabbits. After 8 weeks, skin and mesenteric arteries were isolated and vascular function assessed by wire myography. Vascular contraction to NA (EMax %KCl: 122±4 vs sham 97±3.7) and U46619 (EMax %KCl: 82±3 vs sham 67±4) were exacerbated in skin arteries from IC (p2+ channels, but an increase in RyR was observed (2^-ddCT: 1.67±0.15 vs sham 0.98±0.08) in VSMCs isolated from IC animals. Peroxiredoxin (Prdx), antioxidant, mRNA was increased in IC (2^-ddCT: 1.95±0.4 vs sham 0.88±0.1, p11 /mL: 4.8±0.6 vs control 1.75±0.2), where Nox5 expression was also increased (AU: 0.11±0.02 vs control MP 0.03±0.006) (p

TRPM7 is a chanzyme that influences cellular Mg 2+ homeostasis and vascular signaling. We demonstrated that aldosterone mediates cellular effects through TRPM7-dependent signaling pathways. Since hyperaldosteronism causes hypertension and Mg 2+ wasting, we questioned whether TRPM7 plays a role in aldosterone-induced hypertension. Wild-type (WT) and TRPM7-deficient (M7+/Δ) mice were treated with aldosterone (600μg/Kg/day) and/or 1% NaCl (drinking water) (aldo, salt or aldo/salt) for 4 weeks. Blood pressure (BP) was evaluated by tail-cuff. Vessel function was investigated in mesenteric arteries by wire and pressure myography. Protein expression was assessed by western-blot and histology. Cardiac fibroblasts (CF) were isolated from WT and M7+/Δ. M7+/Δ exhibited increased BP by aldo (140mmHg), salt (135mmHg) and aldo/salt (137mmHg) vs M7+/Δ-veh (117mmHg) (p

Notch3 is implicated in CADASIL and pulmonary arterial hypertension (PAH), two diseases characterized by vascular dysfunction and remodelling. Mice harbouring the CADASIL-causing Notch3 mutation (TgNotch3 R169C ) exhibit gain-of-function Notch3 signalling. As increased Notch3 signalling has been demonstrated in several PAH models, we investigated the contribution of R169C mutation to pulmonary vascular dysfunction and PAH development. Briefly, vascular reactivity was studied by wire myography using pulmonary intralobar arteries from 24-week male mice overexpressing either a WT or R169C mutant Notch3 gene. Further mice were exposed to 2 weeks of normoxia or chronic hypobaric hypoxia (10% O 2 ) before assessing PAH development by in vivo haemodynamic measurements. Notch3 effector gene Hes5, implicated in PAH development, was significantly increased in R169C but not WT lung (8.7 fold change vs WT) suggesting increased pulmonary Notch3 activation. Hypercontractility of R169C pulmonary arteries to both 5HT (Emax R169C 146 ± 10% vs WT 92 ± 6%) and ET-1 (Emax R169C 211 ± 15% vs WT 154 ± 32%) was observed; an effect attenuated by ROCK inhibitor Fasudil (5HT Emax R169C + Fas. 117% ± 20%, ET-1 R169C + Fas. 154 ± 11%) (p

Objective: This study sought to investigate whether aldosterone may induce vascular functional and structural alterations in part through p66shc-dependent processes. Design and method: P66shc -/- mice (14 weeks, 6 per group) and age-matched wild type (WT) control mice were treated or not with aldosterone (300 μg /kg/ day) for 4 weeks. Systolic blood pressure (SBP) was measured by tail-cuff method. Endothelium-dependent and independent relaxation was assessed by concentration-response curves to acetylcholine ± L-NAME (100 μM) and sodium nitroprusside (SNP) respectively, in mesenteric arteries pre-contracted with norepinephrine (10 μM). Media-to-lumen ratio (M/L) and cross sectional area (CSA) were evaluated in vessels as pressurized preparations. Reactive oxigen species (ROS) production was evaluated by DHE staining in aorta. Nox 1 expression was evaluated by immunoblotting. Results: SBP was similar in WT and p66shc -/- mice before treatment and was significantly increased after aldosterone treatment in both WT (192.3±4.522 vs 103.3±2.996; p-/- mice (176.8±5.313 vs 105.3±1.542; p-/- mice treated with aldosterone as compared to WT treated mice (176.8±5.313 vs 192.3±4.522, p-/- mice and was significantly reduced only in WT after treatment. Acetylcholine induced relaxation was blunted by L-NAME in all the groups although at less extent in WT. Endothelium-independent vasodilation was similarly preserved in all the groups. M/L ratio was similar in both WT and p66shc -/- before treatment and was significantly increased by aldosterone only in WT group (p-/- mice and were significantly increased after treatment only in WT (+20% and +2,5 fold respectively, P Conclusions: Despite BP increase, aldosterone induced endothelial dysfunction and vascular remodeling with associated increased oxidative stress in WT but not in p66shc -/- mice. Thus, p66shc may play a role in molecular mechanisms of endothelial dysfunction and vascular remodeling in aldosterone-induced hypertension.

TRPM6 and 7 are channels important in Mg 2+ and Ca 2+ homeostasis. We demonstrated that TRPM7 is influenced by angiotensin II. TRPM6 is influenced by EGF and cancer patients treated with EGFR inhibitors exhibit hypomagnesemia and hypertension by unclear mechanisms. Whether growth factors influence vascular TRPM7 is unknown. Here we questioned if VEGF/EGF mediate vascular effects through TRPM7. Studies were performed in human VSMC, wild type (WT) and TRPM7-deficient (M7+/Δ) mice. VSMC were stimulated with VEGF or EGF (50ng/ml) in the absence/presence of vatalanib, gefitinib (1μM), 2APB (30μM) and NS8593 (40μM), inhibitors of VEGFR, EGFR and TRPM7 respectively. Ca 2+ and Mg 2+ levels were assessed by Cal-520 and Mg-green. VEGF/EGF signaling was assessed by immunoblotting and vascular function by myography in mesenteric arteries from WT and M7+/Δ mice and treated with EGF or VEGF (50ng/ml). TRPM7 expression in aortas and kidneys from WT treated with vatalanib or gefitinib (100mg/Kg/day, 2 weeks) was assessed by immunoblotting. VEGF and EGF increased TRPM7 expression (50% and 67% respectively) and phosphorylation (2-fold), promoted influx of Ca 2+ (8% and 10%) and Mg 2+ (8%), effects that were reduced by vatalanib, gefitinib, NS8593, and 2-APB. EGF but not VEGF increased phosphorylation of PKC (43%), p38MAPK (47%), and ERK1/2 (120%). These responses were reduced by gefitinib, however only ERK1/2 phosphorylation was inhibited by NS8593, and 2-APB. Mice treated with vatalanib or gefitinib showed reduced expression of TRPM7 in aortas (50% and 74% respectively) and kidneys (36% and 66% respectively). Vessels exposed to EGF were less responsive to acetylcholine (ACh)-induced relaxation, [Emax %: WT (veh 97±3 vs EGF 63±10, p2+ and Ca 2+ are important.

Background: A metabolic shift in energy expenditure toward a catabolic state upon high sodium (Na + ) diet, ultimately favouring endogenous water accrual and body fluid preservation, has recently been described in a rodent model. Objective: To investigate the impact of high Na + intake on renal Na + /water handling and metabolic signatures in a large real-life cohort of patients. Methods and Results: We analysed biochemical data from 767 hypertensive patients (429 males, 55.9%; age 47 ± 13 years; BMI 25.6 [23.0-29.0] kg/m 2 ) in washout from drugs affecting the renin-angiotensin-aldosterone system at the time of screening for secondary causes and with a conclusive diagnosis of essential hypertension (2012-2017). Classes of Na + intake ( L ow ≤2.3g/d; M edium 2.3-5g/d; H igh >5g/d) were defined based on urinary 24h Na + excretion (uNaV). The fractional excretion (FE) of Na + increased with increasing Na + intake (L: 0.39% [0.30-0.47] vs H: 0.81% [0.73-0.98], p < 0.001), while FE of free water decreased (L: 1.13% [0.73-1.72] vs H: 0.89% [0.69-1.12], p = 0.015). uNaV was an independent predictor of glomerular filtration rate (GFR, estimated by creatinine clearance; H: 130 ± 33 vs M: 111 ± 52 and L: 96 ± 39 ml/min/1.73m 2 ; p < 0.001 for comparisons) after correction for age, sex, BMI, renin, aldosterone and uKV (p = 0.001). This resulted in a marked increase in the 24h tubular Na + reabsorption and, accordingly, in the estimated energy expenditure (Δ H vs L= 18 [12-24] kcal/d, p < 0.001). At non-targeted LC/MS metabolomics (n = 67), metabolites increased (p < 0.05) in H vs L Na + intake mostly entailed intermediates or end products of the urea cycle and products of protein catabolism. Urinary 24h cortisol excretion, as a potential determinant of catabolism, increased with Na + intake (n = 137; L: 63 [36-72] nmol, M: 60 [47-86] nmol, H: 86 [75-139] nmol; p < 0.001), but its strongest predictor at multivariate regression analysis was GFR (p = 0.001). Conclusions: Kidneys can effectively dissociate Na + and water handling upon high Na + diet, at the cost of glomerular hyperfiltration, enhanced glomerulotubular balance, increased tubular energy expenditure and, ultimately, protein catabolism from endogenous or excess exogenous sources. This has broad implications on global cardiovascular risk.

We previously reported that Nox5 regulates contraction through mechanisms involving ROS and Ca 2+ channels in the endoplasmic reticulum (ER). In young mice expressing human Nox5 in VSMCs (Nox5+SM22+), we observed hypercontractility, without changes in blood pressure. Here we tested the hypothesis that Nox5 influences ER Ca 2+ homeostasis and vascular function and that Nox5 amplifies aging-associated vascular dysfunction through processes involving ER stress. Female WT and Nox5+SM22+ mice aged 20 and 35weeks were studied. Blood pressure (BP) was assessed by tail-cuff and vascular function/structure by myography. BP was similar in all groups. Vascular contraction to U46619, a TXA2 analogue, was increased in aged Nox5+SM22+ (EMax - %KCl: 114±2.8 vs WT 95±2.4, p2+ channel blocker - 0.01 mM, EMax: 67±4.2%) (p2+ homeostasis and channel function, as a molecular target of Nox5. As Nox regulates signalling by oxidation, we assessed calreticulin oxidation by pulldown using dimedone based probe (DCP-Bio). Calreticulin oxidation was increased in mesenteric arteries, aorta and VSMCs from 35 week Nox5+SM22+. Moreover, expression of calreticulin (23.5±2%) and BIP (27.6±9%) was increased by U46619 in VSMCs from Nox5+SM22+ (p

Growing evidence indicates that cells are able to communicate with neighbouring and distant cells in the body by production of extracellular vesicles (EV). EV are classified according to their size and mechanisms of formation. Exosomes and microparticles are the most extensively studied clinically relevant forms of EV, and they often reflect the activation status of the parent cell, by carrying similar surface markers and cargo. Because of these molecular characteristics, EV are considered to be mediators of cell activation by transferring molecules (e.g., proteins, lipids, and nucleic acids) to neighbouring or distant cell populations. Increased levels of circulating EV have been observed in various diseases, including hypertension, atherosclerosis, kidney diseases, and cancer. In this chapter, we will address the formation of different EV and their importance in cell-cell communication, controlling basic cellular functions in homeostatic and pathologic conditions associated with cardiovascular diseases. In addition, we highlight their role as biomarkers and discuss the potential of EV as therapeutic tools.

The vascular system comprises large-, medium- and small-sized vessels, classified as arteries or veins. This system is extremely diverse in structure, architecture and physiology. The vascular wall is composed of three layers: intima, media and adventitia. The intima layer is mainly formed by a monolayer of endothelial cells, which are important to the regulation of vascular smooth cell relaxation and contraction by the production of endothelial-derived relaxing and constricting factors. The media layer is mostly composed by vascular smooth muscle cells that play a major role in changes of vascular diameter and maintenance of vascular tone. In the adventitia, the perivascular adipose tissue has been described as an important regulator of vascular function and inflammation. In this chapter, we will describe the phenotype of endothelial cells, vascular smooth muscle cells and perivascular adipose tissue, focusing on their role to maintain vascular tone and integrity in health and disease.