Abstract P341: Osteoprotegerin-induced ROS Production and Redox Signalling is Exacerbated in Hypertension and Involves Syndecan-1 and TRPM2 Activation

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Augusto C Montezano ◽  
Ross Hepburn ◽  
Delyth Graham ◽  
Rhian M Touyz
Keyword(s):  
Vascular Function ◽  
Molecular Mechanisms ◽  
Metabolic Diseases ◽  
Vascular Dysfunction ◽  
Ros Generation ◽  
Ros Production ◽  
Redox Signalling ◽  
Wky Rats ◽  
Amplex Red ◽  
Src Activation

Osteoprotegerin (OPG) levels are increased in metabolic diseases, and are a biomarker of vascular dysfunction and cardiovascular risk. Mechanisms related to OPG-induced vascular dysfunction and its role in hypertension are not fully understood, but we previously demonstrated that OPG induces vascular dysfunction through ROS-dependent mechanisms. Here we assessed the molecular mechanisms whereby OPG regulates ROS and vascular function, with a focus on syndecan-1. VSMCs from normotensive (WKY) and hypertensive (SHRSP) rats were stimulated with OPG (50 ng/mL). ROS production was measured by lucigenin, amplex red and ELISA. In VSMCs from WKY rats, OPG increased ROS generation (158±15% vs veh, p<0.05). This effect was blocked by the syndecan-1 inhibitor (synstatin) and by removal of syndecan-1 sulfate proteoglycans side chains, chondroitinase and heparinase. OPG also increased H 2 O 2 (2 fold) and ONOO - (1.5 fold) levels in VSMCs (p<0.05). H 2 O 2 further stimulates ROS levels and redox signalling through activation of TRPM2, a redox-sensitive Ca 2+ channel. TRPM2 inhibitors, 8-bromo-ADPR (8Br) and N-(p-amylcinnamoyl)anthranilic acid (ACA), did not block OPG-induced ROS generation in VSMCs from WKY rats. Syndecan-1 activation leads to FAK and c-Src activation, which are redox-sensitive signalling proteins. FAK, but not c-Src, activation (117±2%, p<0.05) was observed after OPG stimulation of WKY VSMCs. In VSMCS from SHRSP rats, OPG effects on ROS generation were exacerbated (230±40%, p<0.05) and inhibited by synstatin, 8Br and ACA. OPG also increased FAK (118±2) and c-Src (113±1) activation (p<0.05) in VSMCs from SHRSP rats. In conclusion, OPG regulation of oxidative stress is increased in hypertension and involves not only syndecan-1, but also TRPM2 channels, which may lead to activation of redox-sensitive proteins and vascular damage.

Abstract P083: Fetuin-a Induces Vascular Dysfunction Through Toll-like Receptor 4 And Nox1/4 Activation

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Karla B Neves ◽  
Rheure A Lopes ◽  
Anastasiya Strembitska ◽  
Ross Hepburn ◽  
Wendy Beattie ◽  
...  
Keyword(s):  
Vascular Function ◽  
Molecular Mechanisms ◽  
Vascular Dysfunction ◽  
Convincing Evidence ◽  
Ros Production ◽  
Toll Like Receptor ◽  
Vascular Effects ◽  
Toll Like Receptor 4 ◽  
Fetuin A ◽  
Wky Rats

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<0.05; effects blocked by tempol (superoxide dismutase mimetic), Nox1 inhibitor, ML171, and TLR4 inhibitor, CLI095. We did not observe any changes in contraction. FetA increased ROS production (62%) and peroxynitrite levels (158%) in VSMCs; while in RAEC, FetA increased ROS production (105%) followed by a decrease in H2O2 (62%) levels (p<0.05 vs control). FetA-induced effects on ROS were inhibited by ML171 and GKT137831 (Nox1/Nox4 inhibitor), as well as CLI095. Vascular dysfunction in arteries from Nox1 and Nox4 KO mice was unaffected by FetA. Activation of the FetA/TLR4/Nox axis led to an increase in IL-1β (190%), Il-6 (124%) and RANTES mRNA expression(116%) in RAEC, p<0.05 vs control. FetA enhanced vascular dysfunctionin LinA3 mice. Together, these results suggest that FetA through TLR4/Nox1 and 4-derived ROS leads to vascular dysfunction and inflammation, which may play an important role in the development of vascular injury during hypertension.

Abstract 263: Differential Effects of 17ß-Estradiol and 16a-Hydroxyestrone in Oxidative Stress and Proliferative Responses in Human Pulmonary Artery Smooth Muscle Cells - Implications in Pulmonary Arterial Hypertension

Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Katie Y Hood ◽  
Augusto C Montezano ◽  
Margaret R MacLean ◽  
Rhian M Touyz
Keyword(s):  
Oxidative Stress ◽  
Pulmonary Arterial Hypertension ◽  
Cell Growth ◽  
Arterial Hypertension ◽  
Molecular Mechanisms ◽  
Antioxidant Systems ◽  
Ros Generation ◽  
Ros Production ◽  
Differential Effects ◽  
Pulmonary Arterial

Women develop pulmonary arterial hypertension (PAH) more frequently than men. This may relate, in part, to metabolism of 17β-estradiol (E2), leading to formation of the deleterious metabolite, 16α-hydroxyestrone (16α OHE1), which plays a role in the remodelling of pulmonary arteries. Molecular mechanisms whereby 16αOHE1 influences PASMC remodelling are unclear but ROS may be important, since oxidative stress has been implicated in the pathogenesis of PAH. We hypothesised that E2 and 16αOHE1 leads to Nox-induced ROS production, which promotes PASMC damage. Cultured PASMCs were stimulated with either E2 (1nM) or 16αOHE1 (1nM) in the presence/absence of EHT1864 (100μM, Rac1 inhibitor) or tempol (antioxidant; 10μM). ROS production was assessed by chemiluminescence (O2-) and Amplex Red (H2O2). Antioxidants (thioredoxin, peroxiredoxin 1 and NQ01), regulators of Nrf2 (BACH1, Nrf2) and, marker of cell growth (PCNA) were determined by immunoblotting. E2 increased O2- production at 4h (219 ± 30% vs vehicle; p<0.05), an effect blocked by EHT1864 and tempol. E2 also increased H2O2 generation (152 ± 4%; p<0.05). Thioredoxin, NQ01 and peroxiredoxin1 (71 ± 6%; 78 ± 9%; 69 ± 8%; p<0.05 respectively) levels were decreased by E2 as was PCNA expression (72 ± 2%; p<0.05). 16αOHE1 exhibited a rapid (5 min) and exaggerated increase in ROS production (355 ± 41%; p<0.05), blocked by tempol and EHT1864. This was associated with an increase in Nox4 expression (139 ± 11% vs vehicle, p<0.05). 16αOHE1 increased BACH1, (129 ± 3%; p<0.05), a competitor of Nrf2, which was decreased (92 ± 2%). In contrast, thioredoxin expression was increased by 16aOHE1 (154 ± 22%; p<0.05). PCNA (150 ± 5%) expression was also increased after exposure to 16αOHE1. In conclusion, E2 and 16αOHE1 have differential effects on redox processes associated with PASMC growth. Whereas E2 stimulates ROS production in a slow and sustained manner without effect on cell growth, 16αOHE1 upregulates Nox4 with associated rapid increase in ROS generation and downregulation of antioxidant systems, affecting proliferation. Our findings suggest that E2 -derived metabolites may promote a pro-proliferative PASMC phenotype through Nox4-derived ROS generation. These deleterious effects may impact on vascular remodeling in PAH.

scholarly journals Vascular Aging in Rodent Models: Contrasting Mechanisms Driving the Female and Male Vascular Senescence

2021 ◽  
Vol 2 ◽  
Author(s):  
Paula R. Barros ◽  
Tiago J. Costa ◽  
Eliana H. Akamine ◽  
Rita C. Tostes
Keyword(s):  
Sex Differences ◽  
Animal Models ◽  
Vascular Function ◽  
Metabolic Diseases ◽  
Vascular Dysfunction ◽  
Laboratory Animals ◽  
Aging Research ◽  
Aging Studies ◽  
Inflammatory Processes ◽  
Vascular Senescence

Increasing scientific interest has been directed to sex as a biological and decisive factor on several diseases. Several different mechanisms orchestrate vascular function, as well as vascular dysfunction in cardiovascular and metabolic diseases in males and females. Certain vascular sex differences are present throughout life, while others are more evident before the menopause, suggesting two important and correlated drivers: genetic and hormonal factors. With the increasing life expectancy and aging population, studies on aging-related diseases and aging-related physiological changes have steeply grown and, with them, the use of aging animal models. Mouse and rat models of aging, the most studied laboratory animals in aging research, exhibit sex differences in many systems and physiological functions, as well as sex differences in the aging process and aging-associated cardiovascular changes. In the present review, we introduce the most common aging and senescence-accelerated animal models and emphasize that sex is a biological variable that should be considered in aging studies. Sex differences in the cardiovascular system, with a focus on sex differences in aging-associated vascular alterations (endothelial dysfunction, remodeling and oxidative and inflammatory processes) in these animal models are reviewed and discussed.

Abstract 010: Adipocyte-derived Aldosterone And Cortisol Are Nox1/4 Dependent: Implications In Obesity-associated Vascular Dysfunction.

Hypertension ◽  
2014 ◽  
Vol 64 (suppl_1) ◽  
Author(s):  
Sarah E Even ◽  
Francisco J Rios ◽  
Aurélie Nguyen Dinh Cat ◽  
Tayze T Antunes ◽  
Marie Briet ◽  
...  
Keyword(s):  
Gene Expression ◽  
Vascular Function ◽  
Culture Media ◽  
Vascular Dysfunction ◽  
Ros Generation ◽  
High Dose ◽  
H2o2 Production ◽  
Ang Ii ◽  
Obese Mice ◽  
Human Adipocytes

We previously demonstrated that aldosterone (aldo) is produced by adipocytes, an effect associated with reactive oxygen species (ROS) production and adipokine production, which influences vascular function. These processes are exaggerated in obesity. Whether ROS themselves play a role in adipocyte-derived aldo is unclear. Studies were performed in db/m (lean) and db/db (obese) mice, treated with low (20mg/kg/day) or high dose (60mg/kg/day) GKT137831 (GKT, Nox1/4 inhibitor, 16 weeks). Epididymal (EVAT) and perivascular (PVAT) fat were collected. Human adipocytes (SW872) were also studied. Aldo and corticosterone levels were measured by ELISA. Gene expression was assessed by qPCR. ROS generation was assessed by chemiluminescence and amplex red. Plasma aldo levels in db/db (pg/mL: 518 vs. 272g) and aldo levels in culture media from db/db adipocytes were increased (pg/mL/μg RNA: 1964 vs. 388), p<0.05. All effects were decreased by high dose GKT. In PVAT, CYP11B2 gene expression was increased in db/db (2.6±0.8 vs control 1.1±0.1, p<0.05), an effect blocked by Nox1/4 inhibition. Corticosterone levels in culture media from db/db adipocytes were also increased. Gene expression of adipocyte differentiation marker, AP2, was increased (3.5±1.1 vs control 1.4±0.4) in obese mice. GKT decreased AP2 levels. In human adipocytes, AngII stimulation increased aldo (6 fold) and cortisol (4 fold) production, as well as superoxide (1 fold) and H2O2 (2 fold) levels (p<0.05 vs vehicle). Increased levels of superoxide by Ang II were blocked by GKT and ML171 (Nox1 inhibitor); while Ang II-induced H2O2 production was inhibited only by GKT. Ang II-induced aldo production was blocked by tempol (SOD mimetic), GKT and ML171. In contrast, cortisol was only blocked by tempol and GKT. In conclusion, aldo production in adipocytes is dependent on ROS formation and involves Nox1 and Nox4. Nox4 also influences adipocyte-derived cortisol. These data suggest that Nox1/4 may play a role in adipocyte-derived aldosterone and cortisol production, effects that are amplified in obesity. Our findings suggest that adipocyte Nox1/4 may be a putative therapeutic target in obesity-associated hyperaldosteronism and cardiovascular damage.

Abstract P090: Nox5 Induces Vascular Damage Through C-src Activation In Human Hypertension

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Livia L Camargo ◽  
Augusto C Montezano ◽  
Misbah Hussain ◽  
Yu Wang ◽  
Zhiguo Zou ◽  
...  
Keyword(s):  
Vascular Function ◽  
Actin Polymerization ◽  
Vascular Dysfunction ◽  
Redox Signaling ◽  
Ros Generation ◽  
Ang Ii ◽  
Human Hypertension ◽  
Src Signaling ◽  
Specific Effects ◽  
And Migration

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%) (p<0.05, vs NT). Activation of c-Src (101±26%), PKC (96±33%), MLC 20 (416±71%) and Ang II-induced Ca 2+ influx (574±44 vs NT:451±26) were also increased in HT (p<0.05, vs NT). Melittin reduced Ang II-induced ROS generation in both groups (p<0.05 vs Ctl). In contrast, p22phox silencing increased ROS in both groups, an effect blocked by melittin (p<0.05 vs Ctl). Nox5 inhibition reduced Ang II-induced c-Src phosphorylation and oxidation. In HT, p22phox silencing was associated with sustained Ang II-induced PKC (83±21% vs Ctl) and MLC 20 (89±22% vs Ctl) phosphorylation, effects blocked by melittin and PP2 (p<0.05 vs Ctl). Nox5 and c-Src inhibition reduced Ca 2+ 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.

scholarly journals 30 YEARS OF THE MINERALOCORTICOID RECEPTOR: The role of the mineralocorticoid receptor in the vasculature

2017 ◽  
Vol 234 (1) ◽  
pp. T67-T82 ◽  
Author(s):  
Jennifer J DuPont ◽  
Iris Z Jaffe
Keyword(s):  
Blood Pressure ◽  
Vascular Function ◽  
Mineralocorticoid Receptor ◽  
Molecular Mechanisms ◽  
Vascular Dysfunction ◽  
Vascular Inflammation ◽  
Kidney Injury ◽  
Vascular Pathology ◽  
The Impact

Since the mineralocorticoid receptor (MR) was cloned 30 years ago, it has become clear that MR is expressed in extra-renal tissues, including the cardiovascular system, where it is expressed in all cells of the vasculature. Understanding the role of MR in the vasculature has been of particular interest as clinical trials show that MR antagonism improves cardiovascular outcomes out of proportion to changes in blood pressure. The last 30 years of research have demonstrated that MR is a functional hormone-activated transcription factor in vascular smooth muscle cells and endothelial cells. This review summarizes advances in our understanding of the role of vascular MR in regulating blood pressure and vascular function, and its contribution to vascular disease. Specifically, vascular MR contributes directly to blood pressure control and to vascular dysfunction and remodeling in response to hypertension, obesity and vascular injury. The literature is summarized with respect to the role of vascular MR in conditions including: pulmonary hypertension; cerebral vascular remodeling and stroke; vascular inflammation, atherosclerosis and myocardial infarction; acute kidney injury; and vascular pathology in the eye. Considerations regarding the impact of age and sex on the function of vascular MR are also described. Further investigation of the precise molecular mechanisms by which MR contributes to these processes will aid in the identification of novel therapeutic targets to reduce cardiovascular disease (CVD)-related morbidity and mortality.

scholarly journals Bufalin Induces Reactive Oxygen Species Dependent Bax Translocation and Apoptosis in ASTC-a-1 Cells

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Lei Sun ◽  
Tongsheng Chen ◽  
Xiaoping Wang ◽  
Yun Chen ◽  
Xunbin Wei
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Molecular Mechanisms ◽  
Caspase 3 ◽  
Temporal Dynamics ◽  
Reactive Oxygen ◽  
Ros Generation ◽  
Ros Production ◽  
Oxygen Species ◽  
Induced Apoptosis

Bufalin has been shown to induce cancer cell death through apoptotic pathways. However, the molecular mechanisms are not well understood. In this study, we used the confocal fluorescence microscopy (CFM) to monitor the spatio-temporal dynamics of reactive oxygen species (ROS) production, Bax translocation and caspase-3 activation during bufalin-induced apoptosis in living human lung adenocarcinoma (ASTC-a-1) cells. Bufalin induced ROS production and apoptotic cell death, demonstrated by Hoechst 33258 staining as well as flow cytometry analysis. Bax redistributed from cytosol to mitochondria from 12 to 48 h after bufalin treatment in living cells expressed with green fluorescent protein Bax. Treatment with the antioxidantN-acetyl-cysteine (NAC), a ROS scavenger, inhibited ROS generation and Bax translocation and led to a significant protection against bufalin-induced apoptosis. Our results also revealed that bufalin induced a prominent increase of caspase-3 activation blocked potently by NAC. Taken together, bufalin induced ROS-mediated Bax translocation, mitochondrial permeability transition and caspase-3 activation, implying that bufalin induced apoptosis via ROS-dependent mitochondrial death pathway in ASTC-a-1 cells.

scholarly journals ROS-induced ROS release in vascular biology: redox-redox signaling

2011 ◽  
Vol 301 (3) ◽  
pp. H647-H653 ◽  
Author(s):  
Natalya S. Zinkevich ◽  
David D. Gutterman
Keyword(s):  
Reactive Oxygen Species ◽  
Adaptive Response ◽  
Vascular Function ◽  
Common Mechanism ◽  
Ros Generation ◽  
Ros Production ◽  
Oxygen Species ◽  
Signaling Function ◽  
A Cell ◽  
Lines Of Evidence

The involvement of reactive oxygen species (ROS) in regulating vascular function both in normal vessels and as part of an adaptive response during disease has been intensively studied. From the recognition that ROS serve as important signaling molecules has emerged multiple lines of evidence that there is a functional connectivity between intracellular sites of ROS production. This cross talk has been termed ROS-induced ROS release (RIRR) and is supported by a variety of observations showing that RIRR is a common mechanism for ROS amplification and regional ROS generation. The compartmentalization of ROS production within a cell is critical to its signaling function and is facilitated by microlocalization of specific scavengers. This review will provide descriptions and examples of important mechanisms of RIRR.

scholarly journals Regulation of ROS Production and Vascular Function by Carbon Monoxide

2012 ◽  
Vol 2012 ◽  
pp. 1-17 ◽  
Author(s):  
Yoon Kyung Choi ◽  
Elaine D. Por ◽  
Young-Guen Kwon ◽  
Young-Myeong Kim
Keyword(s):  
Carbon Monoxide ◽  
Vascular Function ◽  
Biological Effects ◽  
Ros Generation ◽  
Ros Production ◽  
Cellular Mechanisms ◽  
Mitochondrial Energy Metabolism ◽  
Cellular Redox ◽  
Cellular Events ◽  
Exogenous Delivery

Carbon monoxide (CO) is a gaseous molecule produced from heme by heme oxygenase (HO). CO interacts with reduced iron of heme-containing proteins, leading to its involvement in various cellular events via its production of mitochondrial reactive oxygen species (ROS). CO-mediated ROS production initiates intracellular signal events, which regulate the expression of adaptive genes implicated in oxidative stress and functions as signaling molecule for promoting vascular functions, including angiogenesis and mitochondrial biogenesis. Therefore, CO generated either by exogenous delivery or by HO activity can be fundamentally involved in regulating mitochondria-mediated redox cascades for adaptive gene expression and improving blood circulation (i.e., O2delivery) via neovascularization, leading to the regulation of mitochondrial energy metabolism. This paper will highlight the biological effects of CO on ROS generation and cellular redox changes involved in mitochondrial metabolism and angiogenesis. Moreover, cellular mechanisms by which CO is exploited for disease prevention and therapeutic applications will also be discussed.

scholarly journals Vascular Dysfunction in Diabetes and Obesity: Focus on TRP Channels

2021 ◽  
Vol 12 ◽  
Author(s):  
Raiana dos Anjos Moraes ◽  
R. Clinton Webb ◽  
Darízy Flávia Silva
Keyword(s):  
Molecular Mechanisms ◽  
Transient Receptor Potential ◽  
Metabolic Diseases ◽  
Trp Channels ◽  
Vascular Dysfunction ◽  
Vascular Complications ◽  
Sensory Nerves ◽  
Perivascular Adipose Tissue ◽  
Cardiometabolic Diseases ◽  
Diabetes And Obesity

Transient receptor potential (TRP) superfamily consists of a diverse group of non-selective cation channels that has a wide tissue distribution and is involved in many physiological processes including sensory perception, secretion of hormones, vasoconstriction/vasorelaxation, and cell cycle modulation. In the blood vessels, TRP channels are present in endothelial cells, vascular smooth muscle cells, perivascular adipose tissue (PVAT) and perivascular sensory nerves, and these channels have been implicated in the regulation of vascular tone, vascular cell proliferation, vascular wall permeability and angiogenesis. Additionally, dysfunction of TRP channels is associated with cardiometabolic diseases, such as diabetes and obesity. Unfortunately, the prevalence of diabetes and obesity is rising worldwide, becoming an important public health problems. These conditions have been associated, highlighting that obesity is a risk factor for type 2 diabetes. As well, both cardiometabolic diseases have been linked to a common disorder, vascular dysfunction. In this review, we briefly consider general aspects of TRP channels, and we focus the attention on TRPC (canonical or classical), TRPV (vanilloid), TRPM (melastatin), and TRPML (mucolipin), which were shown to be involved in vascular alterations of diabetes and obesity or are potentially linked to vascular dysfunction. Therefore, elucidation of the functional and molecular mechanisms underlying the role of TRP channels in vascular dysfunction in diabetes and obesity is important for the prevention of vascular complications and end-organ damage, providing a further therapeutic target in the treatment of these metabolic diseases.

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