Abstract 138: Altered Vascular Reactivity in Mice Overexpressing Adipocyte Mineralocorticoid Receptors - Role of Rho Kinase.

Aldosterone (aldo) plays a role in cardiovascular diseases, including hypertension and obesity. We previously demonstrated that adipocyte-derived factors regulate vascular function and cell signaling in cultured vascular smooth muscle cells. Moreover, adipocytes are able to produce aldo, which influences vascular reactivity. Plasma levels of aldo are positively correlated with obesity and hypertension. However, the pathophysiological role of aldo and mineralocorticoid receptors (MR) in adipose tissue and its interactions with the vasculature remains elusive. In our study, we investigated molecular mechanisms whereby activation of MR, in adipocytes, leads to release of vascular reactive factors and regulation of vascular tone, using a conditional transgenic mouse model that overexpresses MR only in the adipocytes. Vascular reactivity of resistance mesenteric arteries to acetylcholine (Ach), sodium nitroprusside and phenylephrine (Phe), in the absence or presence of fat conditioned medium (Fcm) from control and adipocyte overexpressing MR (DT) mice, was performed by myography. In basal conditions, endothelial dysfunction was not observed in DT or control mice. However, in the presence of Fcm from DT mice, relaxation to Ach was impaired in control mice (Ach 10 -6 M: 77.5±9.6% no Fcm vs. 49.8±7.5% Fcm, p<0.05), an effect blocked by N-acetyl-cysteine (anti-oxidant) (Ach 10 -6 M: 82.2±6.6%). Resistance arteries from DT mice had decreased Phe-induced contraction, compared to control mice (Phe 10 -5 M: 2.7±0.2 mN/mm CT vs. 1.7±0.2 mN/mm DT, p<0.05). Phosphorylation of ezrin, a marker of Rho kinase activation, measured by immunoblotting, was decreased in white and brown adipose tissues of DT (CT: 3.1±0.7 vs. DT: 0.6±0.1, arbitrary units, p<0.05). In conclusion, MR in adipocytes may play an important role in the regulation of vascular function, and may be involved in vascular oxidative stress. MR in adipocytes is also important to the anti-contractile properties of the adipose tissue through downregulation of Rho kinase signaling. Our study identiy novel mechanisms linking vascular and adipose biology through adipocyte MRs.

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Abstract 66: Altered Vascular Reactivity in Mice Overexpressing Adipocyte Mineralocorticoid Receptors - Role of Oxidative Stress and Rho Kinase

Hypertension ◽

10.1161/hyp.62.suppl_1.a66 ◽

2013 ◽

Vol 62 (suppl_1) ◽

Author(s):

Aurelie Nguyen Dinh Cat ◽

Glaucia E Callera ◽

Tayze T Antunes ◽

Augusto C Montezano ◽

Ying He ◽

...

Keyword(s):

Adipose Tissue ◽

Endothelial Dysfunction ◽

Vascular Function ◽

Vascular Reactivity ◽

Vascular Dysfunction ◽

Rho Kinase ◽

Mesenteric Arteries ◽

Resistance Arteries ◽

Tissue Interactions

Aldosterone (aldo) plays a role in obesity and cardiovascular diseases, such as hypertension. We previously demonstrated that adipocyte-derived factors regulate vascular function and vascular smooth muscle cells signaling. Moreover, adipocytes express aldosterone synthase (CYP11B2) and produce aldo. The mineralocorticoid receptor (MR), which is responsible for aldo signaling, is also found in these cells, but its role in regulating adipose tissue interactions with the vasculature is unknown. In this study, we investigated mechanisms whether MR activation in adipocytes regulates vascular reactivity. Conditional transgenic mice that overexpress MR in an adipocyte-specific manner were studied. Vascular reactivity of resistance mesenteric arteries to acetylcholine (Ach), sodium nitroprusside and phenylephrine (Phe), in the absence or presence of fat conditioned medium (Fcm) from control and adipocyte overexpressing MR (MROE) mice, was performed by myography. In basal conditions, endothelial dysfunction was not observed in MROE or control (Ctr) mice. However, exposure of arteries from control mice to Fcm from MROE mice induces endothelial dysfunction (Ach 10 -6 M: 77.5±9.6% no Fcm vs. 49.8±7.5% Fcm, p<0.05), an effect blocked by N-acetyl-cysteine (an antioxidant) (Ach 10 -6 M: 82.2±6.6%). Resistance arteries from MROE mice had decreased Phe-induced contraction, compared to control mice (Phe 10 -5 M: 2.7±0.2 mN/mm Ctr vs. 1.7±0.2 mN/mm MROE, p<0.05). Rho Kinase activity, which regulates vascular contraction, is decreased in arteries and adipo tissue from MROE (mesenteric arteries, Ctr: 100±16.2% vs. MROE: 31.1±6.1%, arbitrary units, p<0.01; adipose tissue, Ctr: 100±12.6% vs. MROE: 51.3±9.3%, arbitrary units, p<0.01). In conclusion, MR in adipocytes may play an important role in the regulation of vascular function, through redox-sensitive pathways and activation of Rho kinase. Our study identifies novel mechanisms linking vascular/adipose tissue biology and aldo/MR activation, which may be particularly important in vascular dysfunction associated with hypertension and hyperaldosteronism.

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Abstract 2474: Rho-Kinase Inhibition Improves Endothelium-Dependent Vasodilation during Hyperinsulinemia in Patients with Metabolic Syndrome

Circulation ◽

10.1161/circ.118.suppl_18.s_733-a ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Francesca Schinzari ◽

Manfredi Tesauro ◽

Valentina Rovella ◽

Augusto Veneziani ◽

Nadia Mores ◽

...

Keyword(s):

Insulin Resistance ◽

Metabolic Syndrome ◽

Vascular Function ◽

Vascular Reactivity ◽

Rho Kinase ◽

Serine Phosphorylation ◽

No Donor ◽

Kinase Inhibition ◽

Impaired Insulin

Impaired insulin-mediated vasodilation in the skeletal muscle may be involved in the development of hypertension in patients with metabolic syndrome (MetS) and contribute to insulin resistance by diminishing the glucose uptake. Rho-kinase, an effector of the small G protein Rho A, plays an important role in hypertension and is reported to interfere with insulin signaling through serine phosphorylation of insulin receptor substrate-1 in blood vessels. We therefore examined the role of Rho-kinase in the pathophysiology of impaired vascular reactivity in patients with MetS by evaluating the effect of Rho-kinase inhibition on NO-dependent vasodilation during hyperinsulinemia. Forearm blood flow (FBF) responses to acetylcholine (ACh), a stimulus for endothelial release of NO, and sodium nitroprusside (SNP), an exogenous NO donor, were assessed during insulin administration (0.1 mU/Kg/min) using the forearm perfusion technique in patients with MetS (n=10) and matched controls (n=10). Patients with MetS were then randomized to intra-arterial infusion of either fasudil (inhibitor of Rho-kinase, 200 μg/min) or placebo and reactivity to ACh and SNP was reassessed. During hyperinsulinemia, vasodilator responses to both ACh and SNP were blunted in patients with MetS (both P>0.001 vs. controls). In patients who received fasudil, its administration did not change unstimulated FBF (P=0.75 vs. insulin alone); the vasodilator response to ACh, however, was significantly enhanced by fasudil (P=0.009 vs. insulin alone), while the response to SNP was not significantly changed (P=0.56). In patients with MetS who received placebo, vascular reactivity to both ACh and SNP was not different than before (both P>0.05). In conclusion, Rho-kinase inhibition during hyperinsulinemia improves endothelium-dependent vasodilator responsiveness in patients with MetS. This suggests that, under those conditions, intravascular activation of Rho-kinase is involved in the pathophysiology of endothelial dysfunction and may constitute a critical mediator linking metabolic and hemodynamic abnormalities in insulin resistance. As a consequence, targeting Rho-kinase might beneficially impact both vascular function and insulin sensitivity in patients with MetS.

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Abstract P217: Nox Compartmentalization, Protein Oxidation and ER Stress in Vascular Smooth Muscle Cells in Hypertension

Hypertension ◽

10.1161/hyp.70.suppl_1.p217 ◽

2017 ◽

Vol 70 (suppl_1) ◽

Author(s):

Livia L Camargo ◽

Augusto C Montezano ◽

Adam Harvey ◽

Sofia Tsiropoulou ◽

Katie Hood ◽

...

Keyword(s):

Er Stress ◽

Protein Oxidation ◽

Vascular Function ◽

Vascular Reactivity ◽

Stress Proteins ◽

Vascular Dysfunction ◽

Mesenteric Arteries ◽

Resistance Arteries ◽

Post Translational Modification ◽

Wistar Kyoto

In hypertension, activation of NADPH oxidases (Noxs) is associated with oxidative stress and vascular dysfunction. The exact role of each isoform in hypertension-associated vascular injury is still unclear. We investigated the compartmentalization of Noxs in VSMC from resistance arteries of Wistar Kyoto (WKY) and spontaneously hypertensive rats (SHR). Expression of Nox1 and Nox4 was increased in SHR cells (96.6±28.7% and 48.2±21.2% vs WKY, p<0.05), as well as basal ROS levels measured by chemiluminescence (110.2±26.4% vs WKY, p<0.05) and amplex red (105.2±33.2% vs WKY, p<0.05). Phosphorylation of unfolded protein response activators, PERK and IRE1α, and expression of ER chaperone BiP were elevated in SHR cells (p<0.05 vs WKY), indicating activation of ER stress response. Immunoblotting after organelle fractionation demonstrated that Noxs are expressed in an organelle-specific manner, with Nox1, 2 and 4 present in plasma membrane, ER and nucleus, but not in mitochondria. In SHR cells, NoxA1ds (Nox1 inhibitor, 10μM) and GKT136901 (Nox1/4 inhibitor, 10μM) decreased AngII-induced ROS levels (p<0.001 vs Ctl). Additionally, mito-tempol (mitochondrial-targeted antioxidant, 50nM) and 4-PBA (ER stress inhibitor, 1mM) decreased basal ROS levels in SHR cells (p<0.05 vs Ctl). Furthermore, oxidation of the antioxidant enzymes Peroxiredoxins (Prx) was increased in SHRSP compared to WKY (2.51±0.14 vs 0.56±0.07, p<0.001). One-dimensional isoelectric focusing revealed that cytosolic Prx2 and mitochondrial Prx3 were more oxidized in SHRSP than WKY cells. Using a biotin-tagged dimedone-based probe (DCP-Bio) we identified oxidation of ER stress proteins BiP and IRE1. To investigate the effect of protein oxidation in vascular function, vascular reactivity was evaluated in isolated mesenteric arteries. Inhibition of general oxidation (DTT 1mM; Emax: 111.7±33.1) and peroxiredoxin (Conoidin A 10nM; Emax: 116.0±7.3) reduces vascular contraction in response to noradrenalin in WKY rats (Emax: 166.6±30.2; p<0.05). These findings suggest an important role for Nox1/4 in redox-dependent organelle dysfunction and post-translational modification of proteins, processes that may play an important role in vascular dysfunction in hypertension.

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Alteration of perivascular adipose tissue function in angiotensin II-induced hypertension

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y09-088 ◽

2009 ◽

Vol 87 (11) ◽

pp. 944-953 ◽

Cited By ~ 28

Author(s):

Robert M.K.W. Lee ◽

Lili Ding ◽

Chao Lu ◽

Li-Ying Su ◽

Yu-Jing Gao

Keyword(s):

Blood Pressure ◽

Adipose Tissue ◽

Angiotensin Ii ◽

Vascular Function ◽

Wistar Rats ◽

Mesenteric Arteries ◽

Resistance Arteries ◽

Hypertensive Rats ◽

Perivascular Adipose Tissue ◽

And Control

We studied the role of perivascular adipose tissue (PVAT) in the control of vascular function in an in vivo experimental model of hypertension produced by angiotensin II infusion by osmotic minipump in adult male Wistar rats. Two weeks after infusion with angiotensin II, blood pressure in treated rats was significantly elevated but heart rate was reduced compared with control rats infused with physiological saline. Contraction of aorta from the 2 groups of rats in response to phenylephrine or serotonin was significantly attenuated by the presence of PVAT in both the presence and absence of endothelium. This attenuation effect on contraction to phenylephrine was higher, however, in vessels from control rats than in vessels from hypertensive rats in the absence of endothelium. In the mesenteric resistance arteries, lumen diameter was larger in both hypertensive and control vessels with intact PVAT than in vessels with PVAT removed. The medial wall was thicker in arteries from hypertensive rats. The presence of PVAT potentiated the contraction induced by KCl in mesenteric arteries from control rats, but not in hypertensive rats. PVAT also attenuated the contraction of mesenteric arteries in response to phenylephrine or serotonin in both hypertensive and control groups. Mesenteric arteries from hypertensive rats were more responsive to stimulation by serotonin than those from control rats. We conclude that the increased blood pressure of Wistar rats that occurred after infusion with angiotensin II was associated with changes in the functions of PVAT in the aorta and mesenteric arteries and in the structure and function of resistance arteries.

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The role of perivascular adipose tissue in vasoconstriction, arterial stiffness, and aneurysm

Hormone Molecular Biology and Clinical Investigation ◽

10.1515/hmbci-2014-0048 ◽

2015 ◽

Vol 21 (2) ◽

Cited By ~ 14

Author(s):

Luis Villacorta ◽

Lin Chang

Keyword(s):

Adipose Tissue ◽

Arterial Stiffness ◽

Vascular Function ◽

Molecular Mechanisms ◽

Inflammatory Cells ◽

Phenotypic Change ◽

Neointimal Formation ◽

Perivascular Adipose Tissue ◽

Fat Depots ◽

Brown Adipose

AbstractSince the “rediscovery” of brown adipose tissue in adult humans, significant scientific efforts are being pursued to identify the molecular mechanisms to promote a phenotypic change of white adipocytes into brown-like cells, a process called “browning”. It is well documented that white adipose tissue (WAT) mass and factors released from WAT influence the vascular function and positively correlate with cardiac arrest, stroke, and other cardiovascular complications. Similar to other fat depots, perivascular adipose tissue (PVAT) is an active endocrine organ and anatomically surrounds vessels. Both brown-like and white-like PVAT secrete various adipokines, cytokines, and growth factors that either prevent or promote the development of cardiovascular diseases (CVDs) depending on the relative abundance of each type and their bioactivity in the neighboring vasculature. Notably, pathophysiological conditions, such as obesity, hypertension, or diabetes, induce the imbalance of PVAT-derived vasoactive products that promote the infiltration of inflammatory cells. This then triggers derangements in vascular smooth muscle cells and endothelial cell dysfunction, resulting in the development of vascular diseases. In this review, we discuss the recent advances on the contribution of PVAT in CVDs. Specifically, we summarize the current proposed roles of PVAT in relationship with vascular contractility, endothelial dysfunction, neointimal formation, arterial stiffness, and aneurysm.

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Abstract MP08: Syndecan-1 is Involved in Osteoprotegerin-induced Vascular Dysfunction

Hypertension ◽

10.1161/hyp.66.suppl_1.mp08 ◽

2015 ◽

Vol 66 (suppl_1) ◽

Author(s):

Augusto C Montezano ◽

Karla B Neves ◽

Rheure A Lopes ◽

Susan Leckerman ◽

Anastasiya Strembitska ◽

...

Keyword(s):

Protein Oxidation ◽

Vascular Reactivity ◽

Molecular Mechanisms ◽

Vascular Dysfunction ◽

Vascular Inflammation ◽

Rho Kinase ◽

Nitric Oxide Donor ◽

H2o2 Production ◽

Resistance Arteries ◽

Vascular Effects

Osteoprotegerin (OPG), an inhibitor of vascular calcification, has pleiotropic vascular effects independently of its actions on calcification. OPG has been associated with vascular inflammation and remodelling and may be important in cardiovascular disease where OPG levels may be elevated. Molecular mechanisms and functional consequences of OPG stimulation in the vasculature are unclear. We propose that syndecan-1, a membrane glycoprotein, may be important and that reactive oxygen species (ROS) play a role in OPG signalling. Vascular reactivity of resistance arteries from WKY rats was studied by wire myography in the presence or absence of OPG (50 ng/mL) and/or synstatin (SSNT - 10-6M - syndecan-1 inhibitor). Rat endothelial cells (EC) and vascular smooth muscle cells (VSMC) were studied. Levels of ROS were measured by chemiluminescence, Amplex Red (H2O2) and ELISA (nitrotyrosine; peroxynitrite - ONOO-). Protein oxidation and levels were measured by immunoblotting. Exposure of resistance arteries to OPG induced endothelial (decreased relaxation to acetylcholine) and VSMC (decreased relaxation to sodium nitroprusside - SNP) dysfunction, as well as, increased contraction to phenylephrine. All responses were blocked by SSNT, N-acetylcisteine (antioxidant) and ML171 (Nox inhibitor). In EC, OPG-induced ROS production (240±46.1% increase vs. veh, p<0.05) was blocked by SSNT. OPG decreased H2O2 production/release (61±5.4% vs. veh) and increased eNOS Thr 495 phosphorylation (inhibitory site) (100±24% vs. veh, p<0.05). In VSMC, OPG increased H2O2 (69±3%) and ONOO- (43±12%) levels, protein oxidation (61±15%), Rho kinase (200±39%) and myosin light chain activation (55±3%) (all vs. veh, p<0.05). Increase in OPG-induced ONOO- levels was exacerbated by SNP (130±16% vs. veh, p<0.05), a nitric oxide donor. In conclusion, vascular dysfunction elicited by OPG is mediated by syndecan-1 and ROS. Whether syndecan-1 also impacts on OPG-sensitive calcification is unclear. Our data identify a novel molecular mechanism through syndecan- 1/ROS that may underlie injurious effects of OPG.

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Abstract P627: The β3 Adrenergic Receptor is Partially Responsible for Anti-contractile Effect of Perivascular Adipose Tissue in Rat Mesenteric Resistance Arteries

Hypertension ◽

10.1161/hyp.66.suppl_1.p627 ◽

2015 ◽

Vol 66 (suppl_1) ◽

Author(s):

Theodora Szasz ◽

Takayuki Matsumoto ◽

Camilla F Wenceslau ◽

R Clinton Webb

Keyword(s):

Adipose Tissue ◽

Adrenergic Receptor ◽

Metabolic Diseases ◽

Mesenteric Arteries ◽

Resistance Arteries ◽

Perivascular Adipose Tissue ◽

Contractile Responses ◽

Contractile Effect ◽

Brown Adipose ◽

Male Wistar Rats

In normal conditions, perivascular adipose tissue (PVAT) decreases contractile responses non-specifically in various vascular beds. This anti-contractile effect of PVAT is reduced in metabolic diseases and hypertension. The β3 adrenergic receptor (β3AR) is a G protein-coupled receptor expressed in adipocytes and involved in lipolysis and thermoregulation. We have previously demonstrated that chronic systemic infusion with a β3AR agonist induces white-to-brown adipose tissue remodeling and enhanced anti-contractile effects of PVAT via activation of cystathionine gamma lyase, enzyme involved in hydrogen sulfide synthesis. We hypothesized that the β3AR is directly mediating release of PVAT relaxing factors. Endothelium-intact mesenteric resistance arteries from adult male Wistar rats were used to measure contractile responses in the presence and absence of PVAT. In the absence of PVAT, the β3AR agonist CL316243 (1 nM-10 μM) did not directly induce relaxation of U46619-contracted arteries. In control conditions, norepinephrine (NE)-induced contraction was significantly reduced in the presence of PVAT. In contrast, incubation with the selective β3AR antagonist L-748337 (100 nM) led to a significant increase in NE-induced contraction in PVAT-intact arteries, while no change was observed in the absence of PVAT (figure). These data suggest that β3AR mediates the anti-contractile effect of PVAT on NE-induced contraction in resistance mesenteric arteries. Considering the structural and functional alterations of PVAT in hypertension, future studies may reveal a potential novel therapeutic approach via targeting of the PVAT β3AR pathway.

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Association of Gut Hormones and Microbiota with Vascular Dysfunction in Obesity

Nutrients ◽

10.3390/nu13020613 ◽

2021 ◽

Vol 13 (2) ◽

pp. 613

Author(s):

Valentina Rovella ◽

Giuseppe Rodia ◽

Francesca Di Daniele ◽

Carmine Cardillo ◽

Umberto Campia ◽

...

Keyword(s):

Adipose Tissue ◽

Endothelial Dysfunction ◽

Gut Microbiota ◽

Vascular Function ◽

Vascular Reactivity ◽

Metabolic Diseases ◽

Gut Hormones ◽

Perivascular Adipose Tissue ◽

Complex Mechanisms

In the past few decades, obesity has reached pandemic proportions. Obesity is among the main risk factors for cardiovascular diseases, since chronic fat accumulation leads to dysfunction in vascular endothelium and to a precocious arterial stiffness. So far, not all the mechanisms linking adipose tissue and vascular reactivity have been explained. Recently, novel findings reported interesting pathological link between endothelial dysfunction with gut hormones and gut microbiota and energy homeostasis. These findings suggest an active role of gut secretome in regulating the mediators of vascular function, such as nitric oxide (NO) and endothelin-1 (ET-1) that need to be further investigated. Moreover, a central role of brain has been suggested as a main player in the regulation of the different factors and hormones beyond these complex mechanisms. The aim of the present review is to discuss the state of the art in this field, by focusing on the processes leading to endothelial dysfunction mediated by obesity and metabolic diseases, such as insulin resistance. The role of perivascular adipose tissue (PVAT), gut hormones, gut microbiota dysbiosis, and the CNS function in controlling satiety have been considered. Further understanding the crosstalk between these complex mechanisms will allow us to better design novel strategies for the prevention of obesity and its complications.

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A Differential Pattern of Batokine Expression in Perivascular Adipose Tissue Depots From Mice

Frontiers in Physiology ◽

10.3389/fphys.2021.714530 ◽

2021 ◽

Vol 12 ◽

Author(s):

Alberto Mestres-Arenas ◽

Joan Villarroya ◽

Marta Giralt ◽

Francesc Villarroya ◽

Marion Peyrou

Keyword(s):

Adipose Tissue ◽

Growth Factor ◽

Thoracic Aorta ◽

Abdominal Aorta ◽

Vascular Function ◽

Vascular System ◽

Mesenteric Arteries ◽

Fibroblast Growth Factor 21 ◽

Perivascular Adipose Tissue ◽

Brown Adipose

Depending on its anatomical placement, perivascular adipose tissue (PVAT) has been found to possess features more (e.g., aortic thoracic) or less (e.g., aortic abdominal) similar to brown/beige adipose tissue in mice, whereas PVAT surrounding the mesenteric arteries and the caudal part of abdominal aorta is similar to white fat. PVAT is thought to influence vascular function through the effects of adipose-secreted molecules on vessels. Brown adipose tissue was recently shown to play differential secretory role via secretion of the so-called batokines but the involvement of differential batokine production in PVAT brown/beige plasticity was unclear. The current study characterizes for the first time the expression of batokines at aortic thoracic PVAT (tPVAT) and aortic abdominal PVAT (aPVAT) in comparison with typical brown and white adipose depots, in basal and thermogenically activated conditions. We found that both PVAT depots increased their expression of genes encoding the batokines bone morphogenetic protein-8b (BMP8B), fibroblast growth factor-21 (FGF21), and kininogen-2 (KNG2) in response to cold, indicating that, under cold-induced thermogenic activation, both thoracic aorta and abdominal aorta would experience intense local exposure to these PVAT-secreted batokines. In contrast, the gene expression levels of growth/differentiation factor-15 and vascular endothelial growth factor-A were induced only in tPVAT. Under short-term high-fat diet-induced thermogenic activation, the thoracic aorta would be specifically exposed to a local increase in PVAT-originating BMP8B, FGF21, and KNG2. Our data support the notion that acquisition of a brown/beige phenotype in PVAT is associated with upregulation of batokines, mainly BMP8B, FGF21, and KNG2, that can differentially target the vascular system.

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