The vascular microenvironment and its stem cells regulate vascular homeostasis

The vascular microenvironment comprises of anatomical structures, extracellular matrix components, and various cell populations, which play a crucial role in regulating vascular homeostasis and influencing vascular structure and function. Under physiological conditions, intrinsic regulation of the vascular microenvironment is required to sustain vascular homeostasis. In contrast, under pathological conditions, alterations to this microenvironment lead to vascular injury and pathological remodeling. According to the anatomy, the vascular microenvironment can be subdivided into three sections from the inside out. The vascular endothelial microenvironment, centered on vascular endothelial cells (VECs), includes the extracellular matrix and various vascular physicochemical factors. The VECs interact with vascular physicochemical factors to regulate the function of various parenchymal cells, including hepatocytes, neurons and tumor cells. The vascular wall microenvironment, comprising the vasa vasorum and their unique stem/progenitor cell niches, plays a pivotal role in vascular inflammation and pathological remodeling. Additionally, the perivascular microenvironment, which includes perivascular adipose tissue, consists of adipocytes and stem cells, which contribute to the pathological processes of atherosclerosis. It is anticipated that targeted regulation of the vascular microenvironment will emerge as a novel approach for the treatment of various diseases. Accordingly, this review will examine the structure of the vascular microenvironment, the regulation of vascular function by vascular cells and stem/progenitor cells, and the role of the vascular microenvironment in regulating cardiovascular diseases.

Advances in the design and development of chemical modulators of the voltage-gated potassium channels KV7.4 and KV7.5

INTRODUCTION

Hypertension remains a major public health concern, with significant morbidity and mortality worldwide. Despite the availability of various antihypertensive medications, blood pressure control remains suboptimal in many individuals. During the last decades, KV7.4 and KV7.5, which were already known from the view of neuronal regulation, emerged as possible important players in the regulation of vascular tone and blood pressure.

AREAS COVERED

This review covers physiological functions and current advancements in the development of KV7.4 and KV7.5 channel modulators. The authors highlight the structural elements likely to be important for the future design of KV7 subtype-selective modulators, underscoring their potential as an innovative hypertension treatment.

EXPERT OPINION

Extensive research has been focused on targeting neuronal KV7.2 and KV7.3 channels, while KV7.4 and KV7.5 attracted less attention. Many of the developed compounds represent derivatives of flupirtine or retigabine, whereby subtype channel selectivity has only been demonstrated for a handful of individual compounds. Novel substances address additional sites within the binding pocket by incorporating new functional groups. A comprehensive and systematic evaluation of a compound set with significant subtype selectivity should be performed. The discovery of new highly active, less toxic, and selective compounds, therefore, remains the goal of further research in the coming years.

The Implications of Aging on Vascular Health

Vascular aging encompasses structural and functional changes in the vasculature, significantly contributing to cardiovascular diseases, which are the leading cause of death globally. The incidence and prevalence of these diseases increase with age, with most morbidity and mortality attributed to myocardial infarction and stroke. Diagnosing and intervening in vascular aging while understanding the mechanisms behind age-induced vascular phenotypic and pathophysiological alterations offers the potential for delaying and preventing cardiovascular mortality in an aging population. This review delves into various aspects of vascular aging by examining age-related changes in arterial health at the cellular level, including endothelial dysfunction, cellular senescence, and vascular smooth muscle cell transdifferentiation, as well as at the structural level, including arterial stiffness and changes in wall thickness and diameter. We also explore aging-related changes in perivascular adipose tissue deposition, arterial collateralization, and calcification, providing insights into the physiological and pathological implications. Overall, aging induces phenotypic changes that augment the vascular system's susceptibility to disease, even in the absence of traditional risk factors, such as hypertension, diabetes, obesity, and smoking. Overall, age-related modifications in cellular phenotype and molecular homeostasis increase the vulnerability of the arterial vasculature to structural and functional alterations, thereby accelerating cardiovascular risk. Increasing our understanding of these modifications is crucial for success in delaying or preventing cardiovascular diseases. Non-invasive techniques, such as measuring carotid intima-media thickness, pulse wave velocity, and flow-mediated dilation, as well as detecting vascular calcifications, can be used for the early detection of vascular aging. Targeting specific pathological mechanisms, such as cellular senescence and enhancing angiogenesis, holds promise for innovative therapeutic approaches.

KCNQ5 Controls Perivascular Adipose Tissue-Mediated Vasodilation

BACKGROUND

Small arteries exhibit resting tone, a partially contracted state that maintains arterial blood pressure. In arterial smooth muscle cells, potassium channels control contraction and relaxation. Perivascular adipose tissue (PVAT) has been shown to exert anticontractile effects on the blood vessels. However, the mechanisms by which PVAT signals small arteries, and their relevance remain largely unknown. We aimed to uncover key molecular components in adipose-vascular coupling.

METHODS

A wide spectrum of genetic mouse models targeting Kcnq3, Kcnq4, and Kcnq5 genes (Kcnq3-/-, Kcnq4-/-, Kcnq5-/-, Kcnq5dn/dn, Kcnq4-/-/Kcnq5dn/dn, and Kcnq4-/-/Kcnq5-/-), telemetry blood pressure measurements, targeted lipidomics, RNA-Seq profiling, wire-myography, patch-clamp, and sharp-electrode membrane potential measurements was used.

RESULTS

We show that PVAT causes smooth muscle cell KV7.5 family of voltage-gated potassium (K+) channels to hyperpolarize the membrane potential. This effect relaxes small arteries and regulates blood pressure. Oxygenation of polyunsaturated fats generates oxylipins, a superclass of lipid mediators. We identified numerous oxylipins released by PVAT, which potentiate vasodilatory action in small arteries by opening smooth muscle cell KV7.5 family of voltage-gated potassium (K+) channels.

CONCLUSIONS

Our results reveal a key molecular function of the KV7.5 family of voltage-gated potassium (K+) channels in the adipose-vascular coupling, translating PVAT signals, particularly oxylipins, to the central physiological function of vasoregulation. This novel pathway opens new therapeutic perspectives.

The Role of Perivascular Adipose Tissue in the Pathogenesis of Endothelial Dysfunction in Cardiovascular Diseases and Type 2 Diabetes Mellitus

Cardiovascular diseases (CVDs) and type 2 diabetes mellitus (T2DM) are two of the four major chronic non-communicable diseases (NCDs) representing the leading cause of death worldwide. Several studies demonstrate that endothelial dysfunction (ED) plays a central role in the pathogenesis of these chronic diseases. Although it is well known that systemic chronic inflammation and oxidative stress are primarily involved in the development of ED, recent studies have shown that perivascular adipose tissue (PVAT) is implicated in its pathogenesis, also contributing to the progression of atherosclerosis and to insulin resistance (IR). In this review, we describe the relationship between PVAT and ED, and we also analyse the role of PVAT in the pathogenesis of CVDs and T2DM, further assessing its potential therapeutic target with the aim of restoring normal ED and reducing global cardiovascular risk.

Perivascular adipose tissue: Fine-tuner of vascular redox status and inflammation

Perivascular adipose tissue (PVAT) refers to the aggregate of adipose tissue surrounding the vasculature, exhibiting the phenotypes of white, beige and brown adipocytes. PVAT has emerged as an active modulator of vascular homeostasis and pathogenesis of cardiovascular diseases in addition to its structural role to provide mechanical support to blood vessels. More specifically, PVAT is closely involved in the regulation of reactive oxygen species (ROS) homeostasis and inflammation along the vascular tree, through the tight interaction between PVAT and cellular components of the vascular wall. Furthermore, the phenotype-genotype of PVAT at different regions of vasculature varies corresponding to different cardiovascular risks. During ageing and obesity, the cellular proportions and signaling pathways of PVAT vary in favor of cardiovascular pathogenesis by promoting ROS generation and inflammation. Physiological means and drugs that alter PVAT mass, components and signaling may provide new therapeutic insights in the treatment of cardiovascular diseases. In this review, we aim to provide an updated understanding towards PVAT in the context of redox regulation, and to highlight the therapeutic potential of targeting PVAT against cardiovascular complications.

Arterial myogenic response and aging

The arterial myogenic response is an inherent property of resistance arteries. Myogenic tone is crucial for maintaining a relatively constant blood flow in response to changes in intraluminal pressure and protects delicate organs from excessive blood flow. Although this fundamental physiological phenomenon has been extensively studied, the underlying molecular mechanisms are largely unknown. Recent studies identified a crucial role of mechano-activated angiotensin II type 1 receptors (AT1R) in this process. The development of myogenic response is affected by aging. In this review, we summarize recent progress made to understand the role of AT1R and other mechanosensors in the control of arterial myogenic response. We discuss age-related alterations in myogenic response and possible underlying mechanisms and implications for healthy aging.

Conductance Artery Wall Layers and Their Respective Roles in the Clearance Functions

Evolutionary organization of the arterial wall into layers occurred concomitantly with the emergence of a highly muscularized, pressurized arterial system that facilitates outward hydraulic conductance and mass transport of soluble substances across the arterial wall. Although colliding circulating cells disperse potential energy within the arterial wall, the different layers counteract this effect: (1) the endothelium ensures a partial barrier function; (2) the media comprises smooth muscle cells capable of endocytosis/phagocytosis; (3) the outer adventitia and perivascular adipocytic tissue are the final receptacles of convected substances. While the endothelium forms a physical and a biochemical barrier, the medial layer is avascular, relying on the specific permeability properties of the endothelium for metabolic support. Different components of the media interact with convected molecules: medial smooth muscle cells take up numerous molecules via scavenger receptors and are capable of phagocytosis of macro/micro particles. The outer layers-the highly microvascularized innervated adventitia and perivascular adipose tissue-are also involved in the clearance functions of the media: the adventitia is the seat of immune response development, inward angiogenesis, macromolecular lymphatic drainage, and neuronal stimulation. Consequently, the clearance functions of the arterial wall are physiologically essential, but also may favor the development of arterial wall pathologies. This review describes how the walls of large conductance arteries have acquired physiological clearance functions, how this is determined by the attributes of the endothelial barrier, governed by endocytic and phagocytic capacities of smooth muscle cells, impacting adventitial functions, and the role of these clearance functions in arterial wall diseases.

Sex Differences in Cardiovascular Impact of Early Metabolic Impairment: Interplay between Dysbiosis and Adipose Inflammation

The evolving view of gut microbiota has shifted toward describing the colonic flora as a dynamic organ in continuous interaction with systemic physiologic processes. Alterations of the normal gut bacterial profile, known as dysbiosis, has been linked to a wide array of pathologies. Of particular interest is the cardiovascular-metabolic disease continuum originating from positive energy intake and high-fat diets. Accumulating evidence suggests a role for sex hormones in modulating the gut microbiome community. Such a role provides an additional layer of modulation of the early inflammatory changes culminating in negative metabolic and cardiovascular outcomes. In this review, we will shed the light on the role of sex hormones in cardiovascular dysfunction mediated by high-fat diet-induced dysbiosis, together with the possible involvement of insulin resistance and adipose tissue inflammation. Insights into novel therapeutic interventions will be discussed as well. SIGNIFICANCE STATEMENT: Increasing evidence implicates a role for dysbiosis in the cardiovascular complications of metabolic dysfunction. This minireview summarizes the available data on the sex-based differences in gut microbiota alterations associated with dietary patterns leading to metabolic impairment. A role for a differential impact of adipose tissue inflammation across sexes in mediating the cardiovascular detrimental phenotype following diet-induced dysbiosis is proposed. Better understanding of this pathway will help introduce early approaches to mitigate cardiovascular deterioration in metabolic disease.

Associations of Visceral Adipose Tissue, Circulating Protein Biomarkers, and Risk of Cardiovascular Diseases: A Mendelian Randomization Analysis

Aim: To evaluate the genetic associations of visceral adipose tissue (VAT) mass with metabolic risk factors and cardiovascular disease (CVD) endpoints and to construct a network analysis about the underlying mechanism using Mendelian randomization (MR) analysis.

Methods and Results: Using summary statistics from genome-wide association studies (GWAS), we conducted the two-sample MR to assess the effects of VAT mass on 10 metabolic risk factors and 53 CVD endpoints. Genetically predicted VAT mass was associated with metabolic risk factors, including triglyceride (odds ratio, OR, 1.263 [95% confidence interval, CI, 1.203–1.326]), high-density lipoprotein cholesterol (OR, 0.719 [95% CI, 0.678–0.763]), type 2 diabetes (OR, 2.397 [95% CI, 1.965–2.923]), fasting glucose (OR, 1.079 [95% CI, 1.046–1.113]), fasting insulin (OR, 1.194 [95% CI, 1.16–1.229]), and insulin resistance (OR, 1.204 [95% CI, 1.16–1.25]). Genetically predicted VAT mass was associated with CVD endpoints, including atrial fibrillation (OR, 1.414 [95% CI, 1.332 = 1.5]), coronary artery disease (OR, 1.573 [95% CI, 1.439 = 1.72]), myocardial infarction (OR, 1.633 [95% CI, 1.484 =1.796]), heart failure (OR, 1.711 [95% CI, 1.599–1.832]), any stroke (OR, 1.29 [1.193–1.394]), ischemic stroke (OR, 1.292 [1.189–1.404]), large artery stroke (OR, 1.483 [1.206–1.823]), cardioembolic stroke (OR, 1.261 [1.096–1.452]), and intracranial aneurysm (OR, 1.475 [1.235–1.762]). In the FinnGen study, the relevance of VAT mass to coronary heart disease, stroke, cardiac arrhythmia, vascular diseases, hypertensive heart disease, and cardiac death was found. In network analysis to identify the underlying mechanism between VAT and CVDs, VAT mass was positively associated with 23 cardiovascular-related proteins (e.g., Leptin, Hepatocyte growth factor, interleukin-16), and inversely with 6 proteins (e.g., Galanin peptides, Endothelial cell-specific molecule 1). These proteins were further associated with 32 CVD outcomes.

Conclusion: Mendelian randomization analysis has shown that VAT mass was associated with a wide range of CVD outcomes including coronary heart disease, cardiac arrhythmia, vascular diseases, and stroke. A few circulating proteins may be the mediators between VAT and CVDs.

Aging Affects KV7 Channels and Perivascular Adipose Tissue-Mediated Vascular Tone

Aging is an independent risk factor for hypertension, cardiovascular morbidity, and mortality. However, detailed mechanisms linking aging to cardiovascular disease are unclear. We studied the aging effects on the role of perivascular adipose tissue and downstream vasoconstriction targets, voltage-dependent K_V7 channels, and their pharmacological modulators (flupirtine, retigabine, QO58, and QO58-lysine) in a murine model. We assessed vascular function of young and old mesenteric arteries in vitro using wire myography and membrane potential measurements with sharp electrodes. We also performed bulk RNA sequencing and quantitative reverse transcription-polymerase chain reaction tests in mesenteric arteries and perivascular adipose tissue to elucidate molecular underpinnings of age-related phenotypes. Results revealed impaired perivascular adipose tissue-mediated control of vascular tone particularly via K_V7.3–5 channels with increased age through metabolic and inflammatory processes and release of perivascular adipose tissue-derived relaxation factors. Moreover, QO58 was identified as novel pharmacological vasodilator to activate XE991-sensitive KCNQ channels in old mesenteric arteries. Our data suggest that targeting inflammation and metabolism in perivascular adipose tissue could represent novel approaches to restore vascular function during aging. Furthermore, K_V7.3–5 channels represent a promising target in cardiovascular aging.

Sexual dimorphism in prostacyclin-mimetic responses within rat mesenteric arteries: A novel role for KV 7.1 in shaping IP-receptor mediated relaxation

Background and Purpose

Prostacyclin mimetics express potent vasoactive effects via prostanoid receptors that are not unequivocally defined, as to date no study has considered sex as a factor. The aim of this study was to determine the contribution of IP and EP₃ prostanoid receptors to prostacyclin mimetic iloprost‐mediated responses, whether K_V7.1–5 channels represent downstream targets of selective prostacyclin‐IP‐receptor agonist MRE‐269 and the impact of the oestrus cycle on vascular reactivity.

Experimental Approach

Within second‐order mesenteric arteries from male and female Wistar rats, we determined (1) relative mRNA transcripts for EP_1–4 (Ptger_1–4), IP (Ptgi) and TXA₂ (Tbxa) prostanoid receptors via RT‐qPCR; (2) the effect of iloprost, MRE‐269, isoprenaline and ML277 on precontracted arterial tone in the presence of inhibitors of prostanoid receptors, potassium channels and the molecular interference of K_V7.1 via wire‐myograph; (3) oestrus cycle stage via histological changes in cervical cell preparations.

Key Results

Iloprost evoked a biphasic response in male mesenteric arteries, at concentrations ≤100 nmol·L⁻¹ relaxing, then contracting the vessel at concentration ≥300 nmol·L⁻¹, a process attributed to IP and EP₃ receptors respectively. Secondary contraction was absent in the females, which was associated with a reduction in Ptger3. Pharmacological inhibition and molecular interference of K_V7.1 significantly attenuated relaxations produced by the selective IP receptor agonist MRE‐269 in male and female Wistar in dioestrus/metoestrus, but not pro‐oestrus/oestrus.

Conclusions and Implications

Stark sexual dimorphisms in iloprost‐mediated vasoactive responses are present within mesenteric arteries. K_V7.1 is implicated in IP receptor‐mediated vasorelaxation and is impaired by the oestrus cycle.

Purinergic signalling in the cardiovascular system-a tribute to Geoffrey Burnstock

Geoffrey Burnstock made groundbreaking discoveries on the physiological roles of purinergic receptors and led on P2 purinergic receptor classification. His knowledge, vision and leadership inspired and influenced the international scientific community. I had the privilege of spending over 10 years (from 1985) with Geoff at the Department of Anatomy and Developmental Biology, initially as a PhD student and then as a postdoctoral research fellow. I regarded him with enormous admiration and affection. This review on purinergic signalling in the cardiovascular system is a tribute to Geoff. It includes some personal recollections of Geoff.

Elementary calcium signaling in arterial smooth muscle

Vascular smooth muscle cells (VSMCs) of small peripheral arteries contribute to blood pressure control by adapting their contractile state. These adaptations depend on the VSMC cytosolic Ca²⁺ concentration, regulated by complex local elementary Ca²⁺ signaling pathways. Ca²⁺ sparks represent local, transient, rapid calcium release events from a cluster of ryanodine receptors (RyRs) in the sarcoplasmic reticulum. In arterial SMCs, Ca²⁺ sparks activate nearby calcium-dependent potassium channels, cause membrane hyperpolarization and thus decrease the global intracellular [Ca²⁺] to oppose vasoconstriction. Arterial SMC Ca_v1.2 L-type channels regulate intracellular calcium stores content, which in turn modulates calcium efflux through RyRs. Ca_v3.2 T-type channels contribute to a minor extend to Ca²⁺ spark generation in certain types of arteries. Their localization within cell membrane caveolae is essential. We summarize present data on local elementary calcium signaling (Ca²⁺ sparks) in arterial SMCs with focus on RyR isoforms, large-conductance calcium-dependent potassium (BK_Ca) channels, and cell membrane-bound calcium channels (Ca_v1.2 and Ca_v3.2), particularly in caveolar microdomains.

Perivascular adipose tissue in age-related vascular disease

Perivascular adipose tissue (PVAT), a crucial regulator of vascular homeostasis, is actively involved in vascular dysfunction during aging. PVAT releases various adipocytokines, chemokines and growth factors. In an endocrine and paracrine manner PVAT-derived factors regulate vascular signalling and inflammation modulating functions of adjacent layers of the vasculature. Pathophysiological conditions such as obesity, type 2 diabetes, vascular injury and aging can cause PVAT dysfunction, leading to vascular endothelial and smooth muscle cell dysfunctions. We and others have suggested that PVAT is involved in the inflammatory response of the vascular wall in diet induced obesity animal models leading to vascular dysfunction due to disappearance of the physiological anticontractile effect. Previous studies confirm a crucial role for pinpointed PVAT inflammation in promoting vascular oxidative stress and inflammation in aging, enhancing the risk for development of cardiovascular disease. In this review, we discuss several studies and mechanisms linking PVAT to age-related vascular diseases. An overview of the suggested roles played by PVAT in different disorders associated with the vasculature such as endothelial dysfunction, neointimal formation, aneurysm, vascular contractility and stiffness will be performed. PVAT may be considered a potential target for therapeutic intervention in age-related vascular disease.

A New Function for Perivascular Adipose Tissue (PVAT): Assistance of Arterial Stress Relaxation

In health, PVAT secretes anti-contractile factors that relax the underlying artery. PVAT’s contributions to vascular function include more than production of vasoactive substances. We hypothesized that PVAT benefits the artery by assisting the function of stress (–induced) relaxation. Thoracic aorta rings from Sprague Dawley rats were mounted in isolated tissue baths with (+) and without (−) PVAT. A cumulative length tension (0–6 grams) was generated. The tension to which the tissue stress relaxed over 30 minutes was recorded; the tension lost was stress relaxation. The presence of PVAT increased the amount of stress relaxation (final tension in mgs; aortic ring −PVAT = 4578 ± 190; aortic ring + PVAT = 2730 ± 274, p < 0.05). PVAT left attached but not encompassing the aorta provided no benefit in cumulative stress relaxation (aortic ring +/− PVAT = 4122 ± 176; p > 0.05 vs −PVAT). A PVAT ring separated from the aorta demonstrated more profound stress relaxation than did the aortic ring itself. Finally, PVAT-assisted stress relaxation was observed in an artery with white fat (superior mesenteric artery) and in aorta from both male and female of another rat strain, the Dahl S rat. Knowledge of this new PVAT function supports PVAT as an essential player in vascular health.

Adipokines and Adipose Tissue-Related Metabolites, Nuts and Cardiovascular Disease

Adipose tissue is a complex structure responsible for fat storage and releasing polypeptides (adipokines) and metabolites, with systemic actions including body weight balance, appetite regulation, glucose homeostasis, and blood pressure control. Signals sent from different tissues are generated and integrated in adipose tissue; thus, there is a close connection between this endocrine organ and different organs and systems such as the gut and the cardiovascular system. It is known that functional foods, especially different nuts, may be related to a net of molecular mechanisms contributing to cardiometabolic health. Despite being energy-dense foods, nut consumption has been associated with no weight gain, weight loss, and lower risk of becoming overweight or obese. Several studies have reported beneficial effects after nut consumption on glucose control, appetite suppression, metabolites related to adipose tissue and gut microbiota, and on adipokines due to their fatty acid profile, vegetable proteins, l-arginine, dietary fibers, vitamins, minerals, and phytosterols. The aim of this review is to briefly describe possible mechanisms implicated in weight homeostasis related to different nuts, as well as studies that have evaluated the effects of nut consumption on adipokines and metabolites related to adipose tissue and gut microbiota in animal models, healthy individuals, and primary and secondary cardiovascular prevention.

Ecklonia Cava Extract Attenuates Endothelial Cell Dysfunction by Modulation of Inflammation and Brown Adipocyte Function in Perivascular Fat Tissue

It is well known that perivascular fat tissue (PVAT) dysfunction can induce endothelial cell (EC) dysfunction, an event which is related with various cardiovascular diseases. In this study, we evaluated whether Ecklonia cava extract (ECE) and pyrogallol-phloroglucinol-6,6-bieckol (PPB), one component of ECE, could attenuate EC dysfunction by modulating diet-induced PVAT dysfunction mediated by inflammation and ER stress. A high fat diet (HFD) led to an increase in the number and size of white adipocytes in PVAT; PPB and ECE attenuated those increases. Additionally, ECE and PPB attenuated: (i) an increase in the number of M1 macrophages and the expression level of monocyte chemoattractant protein-1 (MCP-1), both of which are related to increases in macrophage infiltration and induction of inflammation in PVAT, and (ii) the expression of pro-inflammatory cytokines (e.g., tumor necrosis factor-α (TNF-α) and interleukin (IL)-6, chemerin) in PVAT which led to vasoconstriction. Furthermore, ECE and PPB: (i) enhanced the expression of adiponectin and IL-10 which had anti-inflammatory and vasodilator effects, (ii) decreased HFD-induced endoplasmic reticulum (ER) stress and (iii) attenuated the ER stress mediated reduction in sirtuin type 1 (Sirt1) and peroxisome proliferator-activated receptor γ (PPARγ) expression. Protective effects against decreased Sirt1 and PPARγ expression led to the restoration of uncoupling protein -1 (UCP-1) expression and the browning process in PVAT. PPB or ECE attenuated endothelial dysfunction by enhancing the pAMPK-PI3K-peNOS pathway and reducing the expression of endothelin-1 (ET-1). In conclusion, PPB and ECE attenuated PVAT dysfunction and subsequent endothelial dysfunction by: (i) decreasing inflammation and ER stress, and (ii) modulating brown adipocyte function.

Single-Cell RNA-Sequencing and Metabolomics Analyses Reveal the Contribution of Perivascular Adipose Tissue Stem Cells to Vascular Remodeling

OBJECTIVE

Perivascular adipose tissue (PVAT) plays a vital role in maintaining vascular homeostasis. However, most studies ascribed the function of PVAT in vascular remodeling to adipokines secreted by the perivascular adipocytes. Whether mesenchymal stem cells exist in PVAT and play a role in vascular regeneration remain unknown. Approach and Results: Single-cell RNA-sequencing allowed direct visualization of the heterogeneous PVAT-derived mesenchymal stem cells (PV-ADSCs) at a high resolution and revealed 2 distinct subpopulations, among which one featured signaling pathways crucial for smooth muscle differentiation. Pseudotime analysis of cultured PV-ADSCs unraveled their smooth muscle differentiation trajectory. Transplantation of cultured PV-ADSCs in mouse vein graft model suggested the contribution of PV-ADSCs to vascular remodeling through smooth muscle differentiation. Mechanistically, treatment with TGF-β1 (transforming growth factor β1) and transfection of microRNA (miR)-378a-3p mimics induced a similar metabolic reprogramming of PV-ADSCs, including upregulated mitochondrial potential and altered lipid levels, such as increased cholesterol and promoted smooth muscle differentiation.

CONCLUSIONS

Single-cell RNA-sequencing allows direct visualization of PV-ADSC heterogeneity at a single-cell level and uncovers 2 subpopulations with distinct signature genes and signaling pathways. The function of PVAT in vascular regeneration is partly attributed to PV-ADSCs and their differentiation towards smooth muscle lineage. Mechanistic study presents miR-378a-3p which is a potent regulator of metabolic reprogramming as a potential therapeutic target for vascular regeneration.

Distinguishing Between Biological and Technical Replicates in Hypertension Research on Isolated Arteries

Perivascular adipose tissue (PVAT) is implicated in the pathophysiology of cardiovascular disease, especially in obese individuals in which the quantity of renal and visceral PVAT is markedly increased. The control of arterial tone by PVAT has emerged as a relatively new field of experimental hypertension research. The discovery of this prototype of vasoregulation has been mostly inferred from data obtained using wire myography. Currently, there is a major discussion on distinguishing between biological vs. technical replicates in biomedical studies, which resulted in numerous guidelines being published on planning studies and publishing data by societies, journals, and associations. Experimental study designs are determined depending on how the experimentator distinguishes between biological vs. technical replicates. These definitions determine the ultimate standards required for making submissions to certain journals. In this article, we examine possible outcomes of different experimental study designs on PVAT control of arterial tone using isolated arteries. Based on experimental data, we determine the sample size and power of statistical analyses for such experiments. We discuss whether n-values should correspond to the number of arterial rings and analyze the resulting effects if those numbers are averaged to provide a single N-value per animal, or whether the hierarchical statistical method represents an alternative for analyzing such kind of data. Our analyses show that that the data (logEC50) from (+) PVAT to (-) PVAT arteries are clustered. Intraclass correlation (ICC) was 31.4%. Moreover, it appeared that the hierarchical approach was better than regular statistical tests as the analyses revealed by a better goodness of fit (v2-2LL test). Based on our results, we propose to use at least three independent arterial rings from each from three animals or at least seven arterial rings from each from two animals for each group, i.e., (+) PVAT vs. (-) PVAT. Finally, we discuss a clinical situation where distinguishing between biological vs. technical replicates can lead to absurd situations in clinical decision makings. We conclude that discrimination between biological vs. technical replicates is helpful in experimental studies but is difficult to implement in everyday's clinical practice.

Loss of miR-146b-3p Inhibits Perivascular Adipocyte Browning with Cold Exposure During Aging

PURPOSE

Pathological changes of the perivascular adipose tissue (PVAT) are directly associated with increased risk of age-related vascular diseases. MicroRNAs regulate adipocyte biological functions including adipogenic differentiation and white adipocyte browning. The present study aims to determine whether miR-146b-3p is involved in the regulation of perivascular adipocyte browning during aging.

METHODS

We utilized a cold-induced animal model to investigate the effect of aging on perivascular adipocyte browning. We also detected the miR-146b-3p expression in the PVAT of young or old mice after cold stimulus. We further investigated the role of miR-146b-3p in regulating perivascular adipocyte browning in vitro and in vivo via administrating miRNA mimics or inhibitors.

RESULTS

Old mice showed decrease of perivascular adipocyte browning and downregulation of miR-146b-3p expression in the PVAT after cold stimulus. Oil red O staining and qPCR indicated that aging perturbed preadipocyte to brown adipocyte differentiation, and expression of miR-146b-3p gradually increased during differentiation. MiR-146b-3p inhibitors blocked brown adipocyte differentiation in young preadipocytes, whereas miR-146b-3p mimics rescued the differentiation of the old preadipocytes. Finally, miR-146b-3p knocks down inhibited perivascular adipocyte browning in young mice after cold stimulus.

CONCLUSION

Aging inhibits perivascular adipocyte browning, and loss of miR-146b-3p is a potential regulator for this process.

Perivascular Adipose Tissue: the Sixth Man of the Cardiovascular System

Perivascular adipose tissue (PVAT) refers to the local aggregate of adipose tissue surrounding the vascular tree, exhibiting phenotypes from white to brown and beige adipocytes. Although PVAT has long been regarded as simply a structural unit providing mechanical support to vasculature, it is now gaining reputation as an integral endocrine/paracrine component, in addition to the well-established modulator endothelium, in regulating vascular tone. Since the discovery of anti-contractile effect of PVAT in 1991, the use of multiple rodent models of reduced amounts of PVAT has revealed its regulatory role in vascular remodeling and cardiovascular implications, including atherosclerosis. PVAT does not only release PVAT-derived relaxing factors (PVRFs) to activate multiple subsets of endothelial and vascular smooth muscle potassium channels and anti-inflammatory signals in the vasculature, but it does also provide an interface for neuron-adipocyte interactions in the vascular wall to regulate arterial vascular tone. In this review, we outline our current understanding towards PVAT and attempt to provide hints about future studies that can sharpen the therapeutic potential of PVAT against cardiovascular diseases and their complications.

Developmental and functional characteristics of the thoracic aorta perivascular adipocyte

Thoracic aorta perivascular adipose tissue (T-PVAT) has critical roles in regulating vascular homeostasis. However, the developmental characteristics and cellular lineage of adipocyte in the T-PVAT remain unclear. We show that T-PVAT contains three long strip-shaped fat depots, anterior T-PVAT (A-T-PVAT), left lateral T-PVAT (LL-T-PVAT), and right lateral T-PVAT (RL-T-PVAT). A-T-PVAT displays a distinct transcriptional profile and developmental origin compared to the two lateral T-PVATs (L-T-PVAT). Lineage tracing studies indicate that A-T-PVAT adipocytes are primarily derived from SM22α+ progenitors, whereas L-T-PVAT contains both SM22α+ and Myf5+ cells. We also show that L-T-PVAT contains more UCP1+ brown adipocytes than A-T-PVAT, and L-T-PVAT exerts a greater relaxing effect on aorta than A-T-PVAT. Angiotensin II-infused hypertensive mice display greater macrophage infiltration into A-T-PVAT than L-T-PVAT. These combined results indicate that L-T-PVAT has a distinct development from A-T-PVAT with different cellular lineage, and suggest that L-T-PVAT and A-T-PVAT have different physiological and pathological functions.

Impaired Vascular Redox Signaling in the Vascular Complications of Obesity and Diabetes Mellitus

Significance: Oxidative stress, a crucial regulator of vascular disease pathogenesis, may be involved in the vascular complications of obesity, systemic insulin resistance (IR), and diabetes mellitus (DM). Recent Advances: Excessive production of reactive oxygen species in the vascular wall has been linked with vascular disease pathogenesis. Recent evidence has revealed that vascular redox state is dysregulated in cases of obesity, systemic IR, and DM, potentially participating in the well-known vascular complications of these disease entities. Critical Issues: The detrimental effects of obesity and the metabolic syndrome on vascular biology have been extensively described at a clinical level. Further, vascular oxidative stress has often been associated with the presence of obesity and IR as well as with a variety of detrimental vascular phenotypes. However, the mechanisms of vascular redox state regulation under conditions of obesity and systemic IR, as well as their clinical relevance, are not adequately explored. In addition, the notion of vascular IR, and its relationship with systemic parameters of obesity and systemic IR, is not fully understood. In this review, we present all the important components of vascular redox state and the evidence linking oxidative stress with obesity and IR. Future Directions: Future studies are required to describe the cellular effects and the translational potential of vascular redox state in the context of vascular disease. In addition, further elucidation of the direct vascular effects of obesity and IR is required for better management of the vascular complications of DM.

Coronary artery hypoxic vasorelaxation is augmented by perivascular adipose tissue through a mechanism involving hydrogen sulphide and cystathionine-β-synthase

AIM

Hypoxia causes vasodilatation of coronary arteries which protects the heart from ischaemic damage through mechanisms including the generation of hydrogen sulphide (H₂ S), but the influence of the perivascular adipose tissue (PVAT) and myocardium is incompletely understood. This study aimed to determine whether PVAT and the myocardium modulate the coronary artery hypoxic response and whether this involves hydrogen sulphide.

METHODS

Porcine left circumflex coronary arteries were prepared as cleaned segments and with PVAT intact, myocardium intact or both PVAT and myocardium intact, and contractility investigated using isometric tension recording. Immunoblotting was used to measure levels of H₂ S-synthesizing enzymes: cystathionine-β-synthase (CBS), cystathionine γ-lyase (CSE) and 3-mercaptopyruvate sulphurtransferase (MPST).

RESULTS

All three H₂ S-synthesizing enzymes were detected in the artery and myocardium, but only CBS and MPST were detected in PVAT. Hypoxia elicited a biphasic response in cleaned artery segments consisting of transient contraction followed by prolonged relaxation. In arteries with PVAT intact, hypoxic contraction was attenuated and relaxation augmented. In arteries with myocardium intact, hypoxic contraction was attenuated, but relaxation was unaffected. In replacement experiments, replacement of dissected PVAT and myocardium attenuated artery contraction and augmented relaxation to hypoxia, mimicking the effect of in situ PVAT and indicating involvement of a diffusible factor(s). In arteries with intact PVAT, augmentation of hypoxic relaxation was reversed by amino-oxyacetate (CBS inhibitor), but not DL-propargylglycine (CSE inhibitor) or aspartate (inhibits MPST pathway).

CONCLUSION

PVAT augments hypoxic relaxation of coronary arteries through a mechanism involving H₂ S and CBS, pointing to an important role in regulation of coronary blood flow during hypoxia.

Perivascular adipose tissue and the dynamic regulation of Kv 7 and Kir channels: Implications for resistant hypertension

Resistant hypertension is defined as high blood pressure that remains uncontrolled despite treatment with at least three antihypertensive drugs at adequate doses. Resistant hypertension is an increasingly common clinical problem in older age, obesity, diabetes, sleep apnea, and chronic kidney disease. Although the direct vasodilator minoxidil was introduced in the early 1970s, only recently has this drug been shown to be particularly effective in a subgroup of patients with treatment-resistant or uncontrolled hypertension. This pharmacological approach is interesting from a mechanistic perspective as minoxidil is the only clinically used K⁺ channel opener today, which targets a subclass of K⁺ channels, namely K_ATP channels in VSMCs. Beside K_ATP channels, two other classes of VSMC K⁺ channels could represent novel effective targets for treatment of resistant hypertension, namely K_v 7 (KCNQ) and inward rectifier potassium (K_ir 2.1) channels. Interestingly, these channels are unique among VSMC potassium channels. First, both have been implicated in the control of microvascular tone by perivascular adipose tissue. Second, they exhibit biophysical properties strongly controlled and regulated by membrane voltage, but not intracellular calcium. This review focuses on K_v 7 (K_v 7.1-5) and K_ir (K_ir 2.1) channels in VSMCs as potential novel drug targets for treatment of resistant hypertension, particularly in comorbid conditions such as obesity and metabolic syndrome.

Plasticity of Adipose Tissue-Derived Stem Cells and Regulation of Angiogenesis

Adipose tissue is recognized as an important organ with metabolic, regulatory, and plastic roles. Adipose tissue-derived stem cells (ASCs) with self-renewal properties localize in the stromal vascular fraction (SVF) being present in a vascular niche, thereby, contributing to local regulation of angiogenesis and vessel remodeling. In the past decades, ASCs have attracted much attention from biologists and bioengineers, particularly, because of their multilineage differentiation potential, strong proliferation, and migration abilities in vitro and high resistance to oxidative stress and senescence. Current data suggest that the SVF serves as an important source of endothelial progenitors, endothelial cells, and pericytes, thereby, contributing to vessel remodeling and growth. In addition, ASCs demonstrate intriguing metabolic and interlineage plasticity, which makes them good candidates for creating regenerative therapeutic protocols, in vitro tissue models and microphysiological systems, and tissue-on-chip devices for diagnostic and regeneration-supporting purposes. This review covers recent achievements in understanding the metabolic activity within the SVF niches (lactate and NAD+ metabolism), which is critical for maintaining the pool of ASCs, and discloses their pro-angiogenic potential, particularly, in the complex therapy of cardiovascular and cerebrovascular diseases.

RXFP1 Receptor Activation by Relaxin-2 Induces Vascular Relaxation in Mice via a Gαi2-Protein/PI3Kß/γ/Nitric Oxide-Coupled Pathway

Background: Relaxins are small peptide hormones, which are novel candidate molecules that play important roles in cardiometablic syndrome. Relaxins are structurally related to the insulin hormone superfamily, which provide vasodilatory effects by activation of G-protein-coupled relaxin receptors (RXFPs) and stimulation of endogenous nitric oxide (NO) generation. Recently, relaxin could be demonstrated to activate G_i proteins and phosphoinositide 3-kinase (PI3K) pathways in cultured endothelial cells in vitro. However, the contribution of the G_i-PI3K pathway and their individual components in relaxin-dependent relaxation of intact arteries remains elusive.

Methods: We used Gα_i2- (Gnai2^-/-) and Gα_i3-deficient (Gnai3^-/-) mice, pharmacological tools and wire myography to study G-protein-coupled signaling pathways involved in relaxation of mouse isolated mesenteric arteries by relaxins. Human relaxin-1, relaxin-2, and relaxin-3 were tested.

Results: Relaxin-2 (∼50% relaxation at 10^-11 M) was the most potent vasodilatory relaxin in mouse mesenteric arteries, compared to relaxin-1 and relaxin-3. The vasodilatory effects of relaxin-2 were inhibited by removal of the endothelium or treatment of the vessels with N (G)-nitro-L-arginine methyl ester (L-NAME, endothelial nitric oxide synthase (eNOS) inhibitor) or simazine (RXFP1 inhibitor). The vasodilatory effects of relaxin-2 were absent in arteries of mice treated with pertussis toxin (PTX). They were also absent in arteries isolated from Gnai2^-/- mice, but not from Gnai3^-/- mice. The effects were not affected by FR900359 (Gα_q protein inhibitor) or PI-103 (PI3Kα inhibitor), but inhibited by TGX-221 (PI3Kβ inhibitor) or AS-252424 (PI3Kγ inhibitor). Simazine did not influence the anti-contractile effect of perivascular adipose tissue.

Conclusion: Our data indicate that relaxin-2 produces endothelium- and NO-dependent relaxation of mouse mesenteric arteries by activation of RXFP1 coupled to G_i2-PI3K-eNOS pathway. Targeting vasodilatory G_i-protein-coupled RXFP1 pathways may provide promising opportunities for drug discovery in endothelial dysfunction and cardiometabolic disease.

The interplay between adipose tissue and the cardiovascular system: is fat always bad?

Obesity is a risk factor for cardiovascular disease (CVD). However, clinical research has revealed a paradoxically protective role for obesity in patients with chronic diseases including CVD, suggesting that the biological 'quality' of adipose tissue (AT) may be more important than overall AT mass or body weight. Importantly, AT is recognised as a dynamic organ secreting a wide range of biologically active adipokines, microRNAs, gaseous messengers, and other metabolites that affect the cardiovascular system in both endocrine and paracrine ways. Despite being able to mediate normal cardiovascular function under physiological conditions, AT undergoes a phenotypic shift characterised by acquisition of pro-oxidant and pro-inflammatory properties in cases of CVD. Crucially, recent evidence suggests that AT depots such as perivascular AT and epicardial AT are able to modify their phenotype in response to local signals of vascular and myocardial origin, respectively. Utilisation of this unique property of certain AT depots to dynamically track cardiovascular biology may reveal novel diagnostic and prognostic tools against CVD. Better understanding of the mechanisms controlling the 'quality' of AT secretome, as well as the communication links between AT and the cardiovascular system, is required for the efficient management of CVD.

Palmitic Acid Methyl Ester and Its Relation to Control of Tone of Human Visceral Arteries and Rat Aortas by Perivascular Adipose Tissue

Background: Perivascular adipose tissue (PVAT) exerts anti-contractile effects on visceral arteries by release of various perivascular relaxing factors (PVRFs) and opening voltage-gated K⁺ (K_v) channels in vascular smooth muscle cells (VSMCs). Palmitic acid methyl ester (PAME) has been proposed as transferable PVRF in rat aorta. Here, we studied PVAT regulation of arterial tone of human mesenteric arteries and clarified the contribution of K_v channels and PAME in the effects.

Methods: Wire myography was used to measure vasocontractions of mesenteric artery rings from patients undergoing abdominal surgery. Isolated aortic rings from Sprague-Dawley rats were studied for comparison. PVAT was either left intact or removed from the arterial rings. Vasocontractions were induced by external high K⁺ (60 mM), serotonin (5-HT) or phenylephrine. PAME (10 nM−3 μM) was used as vasodilator. K_v channels were blocked by XE991, a K_v7 (KCNQ) channel inhibitor, or by 4-aminopyridine, a non-specific K_v channel inhibitor. PAME was measured in bathing solutions incubated with rat peri-aortic or human visceral adipose tissue.

Results: We found that PVAT displayed anti-contractile effects in both human mesenteric arteries and rat aortas. The anti-contractile effects were inhibited by XE991 (30 μM). PAME (EC₅₀ ~1.4 μM) was capable to produce relaxations of PVAT-removed rat aortas. These effects were abolished by XE991 (30 μM), but not 4-aminopyridine (2 mM) or NDGA (10 μM), a lipoxygenases inhibitor. The cytochrome P450 epoxygenase inhibitor 17-octadecynoic acid (ODYA 10 μM) and the soluble epoxide hydrolase inhibitor 12-(3-adamantan-1-ylureido)-dodecanoic acid (AUDA 10 μM) slightly decreased PAME relaxations. PAME up to 10 μM failed to induce relaxations of PVAT-removed human mesenteric arteries. 5-HT induced endogenous PAME release from rat peri-aortic adipose tissue, but not from human visceral adipose tissue.

Conclusions: Our data also suggest that K_v7 channels are involved in the anti-contractile effects of PVAT on arterial tone in both rat aorta and human mesenteric arteries. PAME could contribute to PVAT relaxations by activating K_v7 channels in rat aorta, but not in human mesenteric arteries.

Renal perivascular adipose tissue: Form and function

Renal sympathetic activity affects blood pressure in part by increasing renovascular resistance via release of norepinephrine (NE) from sympathetic nerves onto renal arteries. Here we test the idea that adipose tissue adjacent to renal blood vessels, i.e. renal perivascular adipose tissue (RPVAT), contains a pool of NE which can be released to alter renal vascular function. RPVAT was obtained from around the main renal artery/vein of the male Sprague Dawley rats. Thoracic aortic PVAT and mesenteric PVAT also were studied as brown-like and white fat comparators respectively. RPVAT was identified as a mix of white and brown adipocytes, because of expression of both brown-like (e.g. uncoupling protein 1) and white adipogenic genes. All PVATs contained NE (ng/g tissue, RPVAT:524 ± 68, TAPVAT:740 ± 16, MPVAT:96 ± 24). NE was visualized specifically in RPVAT adipocytes by immunohistochemistry. The presence of RPVAT (+RPVAT) did not alter the response of isolated renal arteries to NE compared to responses of arteries without RPVAT (-RPVAT). By contrast, the maximum contraction to the sympathomimetic tyramine was ~2× greater in the renal artery +PVAT versus -PVAT. Tyramine-induced contraction in +RPVAT renal arteries was reduced by the α₁-adrenoceptor antagonist prazosin and the NE transporter inhibitor nisoxetine. These results suggest that tyramine caused release of NE from RPVAT. Renal denervation significantly (>50%) reduced NE content of RPVAT but did not modify tyramine-induced contraction of +RPVAT renal arteries. Collectively, these data support the existence of a releasable pool of NE in RPVAT that is independent of renal sympathetic innervation and has the potential to change renal arterial function.

Vascular dysfunction in obese diabetic db/db mice involves the interplay between aldosterone/mineralocorticoid receptor and Rho kinase signaling

Activation of aldosterone/mineralocorticoid receptors (MR) has been implicated in vascular dysfunction of diabetes. Underlying mechanisms are elusive. Therefore, we investigated the role of Rho kinase (ROCK) in aldosterone/MR signaling and vascular dysfunction in a model of diabetes. Diabetic obese mice (db/db) and control counterparts (db/+) were treated with MR antagonist (MRA, potassium canrenoate, 30 mg/kg/day, 4 weeks) or ROCK inhibitor, fasudil (30 mg/kg/day, 3 weeks). Plasma aldosterone was increased in db/db versus db/+. This was associated with enhanced vascular MR signaling. Norepinephrine (NE)-induced contraction was increased in arteries from db/db mice. These responses were attenuated in mice treated with canrenoate or fasudil. Db/db mice displayed hypertrophic remodeling and increased arterial stiffness, improved by MR blockade. Vascular calcium sensitivity was similar between depolarized arteries from db/+ and db/db. Vascular hypercontractility in db/db mice was associated with increased myosin light chain phosphorylation and reduced expression of PKG-1α. Vascular RhoA/ROCK signaling and expression of pro-inflammatory and pro-fibrotic markers were exaggerated in db/db mice, effects that were attenuated by MRA. Fasudil, but not MRA, improved vascular insulin sensitivity in db/db mice, evidenced by normalization of Irs1 phosphorylation. Our data identify novel pathways involving MR-RhoA/ROCK-PKG-1 that underlie vascular dysfunction and injury in diabetic mice.

C1q/TNF-related protein 9 improves the anti-contractile effects of perivascular adipose tissue via the AMPK-eNOS pathway in diet-induced obese mice

The anti-contractile property of perivascular adipose tissue (PVAT) is abolished through an endothelium-dependent pathway in obesity. C1q/tumor necrosis factor-related protein (CTRP)9 improved endothelial function by promoting endothelium-dependent vasodilatation. The aims of this study were to investigate whether CTRP9 improves the anti-contractile effect of PVAT and protects against PVAT dysfunction in obese mice. The mice were treated with a high-fat diet with or without CTRP9 treatment. Thoracic aortas with or without PVAT (PVAT+ or PVAT-) were prepared, and concentration-dependent responses to phenylephrine were measured. Obese mice showed a significantly increased contractile response, which was suppressed by CTRP9 treatment both with and without PVAT. PVAT significantly reduced the anti-contractile effect in obese mice, which was partially restored by CTRP9 treatment. Treatment of the aortic rings (PVAT+) with inhibitors of AMP protein kinase (AMPK), Akt and endothelial nitric oxide synthase (eNOS) attenuated the beneficial effect of CTRP9 on PVAT. Similar results were observed when we pretreated the aortic rings with CTRP9 ex vivo. CTRP9 significantly enhanced the phosphorylation levels of AMPK, Akt and eNOS, and reduced superoxide production and TNF-α levels in PVAT from obese mice. Our study suggests that CTRP9 enhanced the anti-contractile effect of PVAT and improved PVAT function by activating the AMPK-eNOS pathway in obese mice.

Role of Perivascular Adipose Tissue in Health and Disease

Perivascular adipose tissue (PVAT) is cushion of fat tissue surrounding blood vessels, which is phenotypically different from other adipose tissue depots. PVAT is composed of adipocytes and stromal vascular fraction, constituted by different populations of immune cells, endothelial cells, and adipose-derived stromal cells. It expresses and releases an important number of vasoactive factors with paracrine effects on vascular structure and function. In healthy individuals, these factors elicit a net anticontractile and anti-inflammatory paracrine effect aimed at meeting hemodynamic and metabolic demands of specific organs and regions of the body. Pathophysiological situations, such as obesity, diabetes or hypertension, induce changes in its amount and in the expression pattern of vasoactive factors leading to a PVAT dysfunction in which the beneficial paracrine influence of PVAT is shifted to a pro-oxidant, proinflammatory, contractile, and trophic environment leading to functional and structural cardiovascular alterations and cardiovascular disease. Many different PVATs surrounding a variety of blood vessels have been described and exhibit regional differences. Both protective and deleterious influence of PVAT differs regionally depending on the specific vascular bed contributing to variations in the susceptibility of arteries and veins to vascular disease. PVAT therefore, might represent a novel target for pharmacological intervention in cardiovascular disease. © 2018 American Physiological Society. Compr Physiol 8:23-59, 2018.

The Kv7 Channel and Cardiovascular Risk Factors

Potassium channels play a pivotal role in the regulation of excitability in cells such as neurons, cardiac myocytes, and vascular smooth muscle cells. The KCNQ (Kv7) family of voltage-activated K⁺ channels hyperpolarizes the cell and stabilizes the membrane potential. Here, we outline how Kv7 channel activity may contribute to the development of the cardiovascular risk factors such as hypertension, diabetes, and obesity. Questions and hypotheses regarding previous and future research have been raised. Alterations in the Kv7 channel may contribute to the development of cardiovascular disease (CVD). Pharmacological modification of Kv7 channels may represent a possible treatment for CVD in the future.