Abstract 177: Promotion Of Nitroso-redox Balance By Beta 3 Adrenoceptor Agonism: Therapeutic Implications For Cardiovascular Complications Of Diabetes

Rationale: Disrupted balance between NO and O2.- is central in pathobiology of diabetes-induced cardiomyopathy and vascular dysfunction. We examined if stimulation of β3 adrenergic receptors (β3 ARs), coupled to endothelial nitric oxide synthase (eNOS) activation, would re-establish NO/O2.- balance, relieve oxidative inhibition of key caveolar proteins and protect against diabetes-induced cardiovascular dysfunction. Methods/Results: A hyperglycemic, hyperinsulinemic state was established in male White New Zealand rabbits by infusion of the insulin receptor antagonist S961 (12 μg/kg/h). Diabetes induced NADPH oxidase-dependent glutathionylation (GSS-) of the caveolar proteins Na+-K+ pump’s β1 subunit and eNOS in cardiac myocytes and aorta, an oxidative modification that inhibits the pump and uncouples eNOS. Consistent with this, diabetes was associated with reduced electrogenic Na+-K+ pump current in voltage-clamped cardiac myocytes and impaired endothelium-dependent vasorelaxation. Selective β3 AR agonist CL316243 (CL, 40 μg/kg/h) restored NO levels analysed by spin-trapping of NO-Fe(DETC)2 complexes; decreased diabetes-induced elevation in O2.- measured by HPLC analysis of dihydroethidium oxidation products, improved endothelium-dependent vasorelaxation, and restored the Na+-K+ pump function in cardiac myocytes. These effects were mediated by CL abolishing diabetes-induced increase in eNOS-GSS and β1-GSS through a decrease in forward reaction rate for glutathionylation by suppressing diabetes-induced NADPH oxidase activation, which was further amplified by promotion of de-glutathionylation via enhancement in association of glutaredoxine-1, the enzyme catalysing de-glutathionylation, with eNOS and Na+-K+ pump. Conclusion: β3 AR activation re-established nitroso-redox balance and relieved oxidative inhibition of key caveolar proteins in diabetes. β3 AR agonists are promising in treatment of diabetes-induced cardiovascular complications.

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β3-Adrenoceptor activation relieves oxidative inhibition of the cardiac Na+-K+ pump in hyperglycemia induced by insulin receptor blockade

AJP Cell Physiology ◽

10.1152/ajpcell.00071.2015 ◽

2015 ◽

Vol 309 (5) ◽

pp. C286-C295 ◽

Cited By ~ 17

Author(s):

Keyvan Karimi Galougahi ◽

Chia-Chi Liu ◽

Alvaro Garcia ◽

Natasha A. Fry ◽

Elisha J. Hamilton ◽

...

Keyword(s):

Oxidative Stress ◽

Nadph Oxidase ◽

Insulin Receptor ◽

Cardiac Myocytes ◽

Cardiac Myocyte ◽

Ex Vivo ◽

Pump Current ◽

Cardiovascular Complications ◽

Oxidative Modification

Dysregulated nitric oxide (NO)- and superoxide (O2·−)-dependent signaling contributes to the pathobiology of diabetes-induced cardiovascular complications. We examined if stimulation of β3-adrenergic receptors (β3-ARs), coupled to endothelial NO synthase (eNOS) activation, relieves oxidative inhibition of eNOS and the Na+-K+ pump induced by hyperglycemia. Hyperglycemia was established in male New Zealand White rabbits by infusion of the insulin receptor antagonist S961 for 7 days. Hyperglycemia increased tissue and blood indexes of oxidative stress. It induced glutathionylation of the Na+-K+ pump β1-subunit in cardiac myocytes, an oxidative modification causing pump inhibition, and reduced the electrogenic pump current in voltage-clamped myocytes. Hyperglycemia also increased glutathionylation of eNOS, which causes its uncoupling, and increased coimmunoprecipitation of cytosolic p47 phox and membranous p22 phox NADPH oxidase subunits, consistent with NADPH oxidase activation. Blocking translocation of p47 phox to p22 phox with the gp91ds-tat peptide in cardiac myocytes ex vivo abolished the hyperglycemia-induced increase in glutathionylation of the Na+-K+ pump β1-subunit and decrease in pump current. In vivo treatment with the β3-AR agonist CL316243 for 3 days eliminated the increase in indexes of oxidative stress, decreased coimmunoprecipitation of p22 phox with p47 phox, abolished the hyperglycemia-induced increase in glutathionylation of eNOS and the Na+-K+ pump β1-subunit, and abolished the decrease in pump current. CL316243 also increased coimmunoprecipitation of glutaredoxin-1 with the Na+-K+ pump β1-subunit, which may reflect facilitation of deglutathionylation. In vivo β3-AR activation relieves oxidative inhibition of key cardiac myocyte proteins in hyperglycemia and may be effective in targeting the deleterious cardiac effects of diabetes.

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Stimulation of the cardiac myocyte Na+-K+ pump due to reversal of its constitutive oxidative inhibition

AJP Cell Physiology ◽

10.1152/ajpcell.00392.2014 ◽

2015 ◽

Vol 309 (4) ◽

pp. C239-C250 ◽

Cited By ~ 13

Author(s):

Karin K. M. Chia ◽

Chia-Chi Liu ◽

Elisha J. Hamilton ◽

Alvaro Garcia ◽

Natasha A. Fry ◽

...

Keyword(s):

Nitric Oxide ◽

Protein Kinase ◽

Nadph Oxidase ◽

Cardiac Myocytes ◽

Cardiac Myocyte ◽

Pump Current ◽

Reciprocal Relationship ◽

Ang Ii ◽

Α Subunit

Protein kinase C can activate NADPH oxidase and induce glutathionylation of the β1-Na+-K+ pump subunit, inhibiting activity of the catalytic α-subunit. To examine if signaling of nitric oxide-induced soluble guanylyl cyclase (sGC)/cGMP/protein kinase G can cause Na+-K+ pump stimulation by counteracting PKC/NADPH oxidase-dependent inhibition, cardiac myocytes were exposed to ANG II to activate NADPH oxidase and inhibit Na+-K+ pump current ( Ip). Coexposure to 3-(5′-hydroxymethyl-2′-furyl)-1-benzylindazole (YC-1) to stimulate sGC prevented the decrease of Ip. Prevention of the decrease was abolished by inhibition of protein phosphatases (PP) 2A but not by inhibition of PP1, and it was reproduced by an activator of PP2A. Consistent with a reciprocal relationship between β1-Na+-K+ pump subunit glutathionylation and pump activity, YC-1 decreased ANG II-induced β1-subunit glutathionylation. The decrease induced by YC-1 was abolished by a PP2A inhibitor. YC-1 decreased phosphorylation of the cytosolic p47 phox NADPH oxidase subunit and its coimmunoprecipitation with the membranous p22 phox subunit, and it decreased O2·−-sensitive dihydroethidium fluorescence of myocytes. Addition of recombinant PP2A to myocyte lysate decreased phosphorylation of p47 phox indicating the subunit could be a substrate for PP2A. The effects of YC-1 to decrease coimmunoprecipitation of p22 phox and p47 phox NADPH oxidase subunits and decrease β1-Na+-K+ pump subunit glutathionylation were reproduced by activation of nitric oxide-dependent receptor signaling. We conclude that sGC activation in cardiac myocytes causes a PP2A-dependent decrease in NADPH oxidase activity and a decrease in β1 pump subunit glutathionylation. This could account for pump stimulation with neurohormonal oxidative stress expected in vivo.

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Sustained Maternal Smoking Triggers Endothelial-Mediated Oxidative Stress in the Umbilical Cord Vessels, Resulting in Vascular Dysfunction

Antioxidants ◽

10.3390/antiox10040583 ◽

2021 ◽

Vol 10 (4) ◽

pp. 583

Author(s):

Szabolcs Zahorán ◽

Péter R. Szántó ◽

Nikolett Bódi ◽

Mária Bagyánszki ◽

József Maléth ◽

...

Keyword(s):

Nitric Oxide ◽

Umbilical Cord ◽

Maternal Smoking ◽

Ex Vivo ◽

Vascular Dysfunction ◽

Redox Balance ◽

Heavy Smoking ◽

Long Term Effect ◽

Oxide Synthase ◽

Endothelial Nitric Oxide

Nitric oxide (NO) bioavailability is fundamental in the regulation of redox balance and functionality of the endothelium, especially in the case of the umbilical cord (UC), which has no innervation. The analysis of UC vessel-related complications could serve as a useful tool in the understanding of the pathophysiological mechanisms leading to neonatal cardiovascular disorders. Therefore, the aim of this study was to characterize the mechanisms that rule the severity of prenatal endothelial dysfunction, induced by the long-term effect of maternal smoking. Our analysis describes the initiation and the consequences of endothelial nitric oxide synthase (NOS3) deactivation, along with the up-regulation of possible compensatory pathways, using structural, molecular and biochemical approaches. This study was carried out on both the UC arteries and veins originated from neonates born to non-smoking and heavy-smoking mothers. The alterations stimulated by maternal smoking are vessel-specific and proportional to the level of exposure to harmful materials passed through the placenta. Typically, in the primarily exposed veins, an increased formation of reactive oxygen species and an up-regulation of the highly-efficient NOS2-NO producing pathway were detected. Despite all the extensive structural and functional damages, the ex vivo heat and cadmium ion-treated UC vein pieces still support the potential for stress response.

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20-HETE increases superoxide production and activates NAPDH oxidase in pulmonary artery endothelial cells

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00278.2007 ◽

2008 ◽

Vol 294 (5) ◽

pp. L902-L911 ◽

Cited By ~ 49

Author(s):

Meetha Medhora ◽

Yuenmu Chen ◽

Stephanie Gruenloh ◽

Daniel Harland ◽

Sreedhar Bodiga ◽

...

Keyword(s):

Endothelial Cells ◽

Pulmonary Artery ◽

Nadph Oxidase ◽

Oxidation Products ◽

Dependent Manner ◽

Ros Production ◽

Concentration Dependent Manner ◽

Physiological Processes ◽

Contraction And Relaxation ◽

Endothelial Nitric Oxide

Reactive oxygen species (ROS) signal vital physiological processes including cell growth, angiogenesis, contraction, and relaxation of vascular smooth muscle. Because cytochrome P-450 family 4 (CYP4)/20-hydroxyeicosatetraenoic acid (20-HETE) has been reported to enhance angiogenesis, pulmonary vascular tone, and endothelial nitric oxide synthase function, we explored the potential of this system to stimulate bovine pulmonary artery endothelial cell (BPAEC) ROS production. Our data are the first to demonstrate that 20-HETE increases ROS in BPAECs in a time- and concentration-dependent manner as detected by enhanced fluorescence of oxidation products of dihydroethidium (DHE) and dichlorofluorescein diacetate. An analog of 20-HETE elicits no increase in ROS and blocks 20-HETE-evoked increments in DHE fluorescence, supporting its function as an antagonist. Endothelial cells derived from bovine aortas exhibit enhanced ROS production to 20-HETE quantitatively similar to that of BPAECs. 20-HETE-induced ROS production in BPAECs is blunted by pretreatment with polyethylene-glycolated SOD, apocynin, inhibition of Rac1, and a peptide-based inhibitor of NADPH oxidase subunit p47phox association with gp91. These data support 20-HETE-stimulated, NADPH oxidase-derived, and Rac1/2-dependent ROS production in BPAECs. 20-HETE promotes translocation of p47phox and tyrosine phosphorylation of p47phox in a time-dependent manner as well as increased activated Rac1/2, providing at least three mechanisms through which 20-HETE activates NADPH oxidase. These observations suggest that 20-HETE stimulates ROS production in BPAECs at least in part through activation of NADPH oxidase within minutes of application of the lipid.

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Differential expression of α2D-adrenoceptor and eNOS in aortas from early and later stages of diabetes in Goto-Kakizaki rats

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.01074.2003 ◽

2004 ◽

Vol 287 (1) ◽

pp. H135-H148 ◽

Cited By ~ 40

Author(s):

Tsuneo Kobayashi ◽

Takayuki Matsumoto ◽

Kazuyuki Ooishi ◽

Katsuo Kamata

Keyword(s):

Vascular Reactivity ◽

Matched Control ◽

Early Stage ◽

Vascular Dysfunction ◽

Spontaneous Diabetes ◽

Relaxation Response ◽

No Production ◽

Gk Rats ◽

Oxide Synthase ◽

Endothelial Nitric Oxide

The aim of the present study was to compare vascular dysfunction between the early (12 wk old) and later (36 wk old) stages of spontaneous diabetes in Goto-Kakizaki (GK) rats. We also evaluated the aortic expression of the α2D-adrenoceptor and endothelial nitric oxide synthase (eNOS). Vascular reactivity was assessed in thoracic aortas from age-matched control rats and 12- and 36-wk GK rats. Using RT-PCR and immunoblots, we also examined the changes in expression of the α2D-adrenoceptor and eNOS. In aortas from GK rats (vs. those from age-matched control rats): 1) the relaxation response to ACh was enhanced at 12 wk but decreased at 36 wk; 2) the relaxation response to sodium nitroprusside was decreased at both 12 and 36 wk, 3) norepinephrine (NE)-induced contractility was decreased at 12 wk but not at 36 wk, 4) the expressions of α1B- and α1D-adrenoceptors were unaffected, whereas those of α2D-adrenoceptor and eNOS mRNAs were increased at both 12 and 36 wk; and 5) NE- and ACh-stimulated NOx (nitrite and nitrate) levels were increased at 12 wk, although at 36 wk ACh-stimulated NOx was lower, whereas NE-stimulated NOx showed no change. These results clearly demonstrate that enhanced ACh-induced relaxation and impaired NE-induced contraction, due to NO overproduction via eNOS and increased α2D-adrenoceptor expression, occur in early-stage GK rats and that the impaired ACh-induced relaxation in later-stage GK rats is due to reductions in both NO production and NO responsiveness (but not in eNOS expression).

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In vivo gene transfer of endothelial nitric oxide synthase to carotid arteries from hypercholesterolemic rabbits enhances endothelium-dependent relaxations but does not reverse vascular dysfunction

Atherosclerosis ◽

10.1016/s0021-9150(99)80224-x ◽

1999 ◽

Vol 144 ◽

pp. 58

Author(s):

T. O'Brien ◽

J. Sato ◽

T. Mohasci ◽

A. Noel ◽

P. Gloviczki ◽

...

Keyword(s):

Nitric Oxide ◽

Nitric Oxide Synthase ◽

Gene Transfer ◽

Endothelial Nitric Oxide Synthase ◽

Carotid Arteries ◽

Vascular Dysfunction ◽

Oxide Synthase ◽

Endothelial Nitric Oxide ◽

In Vivo Gene Transfer

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Grape pomace enzymatic extract restores vascular dysfunction evoked by endothelin-1 and DETCA via NADPH oxidase downregulation and SOD activation

Journal of Functional Foods ◽

10.1016/j.jff.2013.07.012 ◽

2013 ◽

Vol 5 (4) ◽

pp. 1673-1683 ◽

Cited By ~ 7

Author(s):

Cristina Perez-Ternero ◽

Rosalia Rodriguez-Rodriguez ◽

Juan Parrado ◽

Maria Alvarez de Sotomayor

Keyword(s):

Nadph Oxidase ◽

Vascular Dysfunction ◽

Grape Pomace ◽

Enzymatic Extract ◽

Endothelin 1

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Abstract 103: ACE2 Overexpression Prevents DOCA-Salt Hypertension by Modulating Oxidative Stress and Nitric Oxide in the Central Nervous System

Hypertension ◽

10.1161/hyp.60.suppl_1.a103 ◽

2012 ◽

Vol 60 (suppl_1) ◽

Author(s):

Srinivas Sriramula ◽

Huijing Xia ◽

Eric Lazartigues

Keyword(s):

Oxidative Stress ◽

Nitric Oxide ◽

Central Nervous System ◽

Nervous System ◽

Nadph Oxidase ◽

Salt Treatment ◽

Salt Hypertension ◽

The Central Nervous System ◽

Oxide Synthase ◽

Endothelial Nitric Oxide

Elevated reactive oxygen species (ROS) in the central nervous system (CNS) through NADPH oxidase and diminished Nitric oxide (NO) levels are involved in the pathogenesis of hypertension. We previously reported that central Angiotensin Converting Enzyme 2 (ACE2) overexpression prevents the development of hypertension induced by DOCA-salt in a transgenic mouse model (syn-hACE2; SA) with human ACE2 targeted selectively to neurons in the CNS. While baseline blood pressure (BP; telemetry) was not different among genotypes, DOCA-salt treatment (1mg/g body wt DOCA, 1% saline in drinking water for 3 weeks) resulted in significantly lower BP level in SA mice (122 ±3 mmHg, n=12) compared to non-transgenic (NT) littermates (138 ±3 mmHg, n=8). To elucidate the mechanisms involved in this response, we investigated the paraventricular nucleus (PVN) expression of Nox-2 (catalytic subunit of NADPH oxidase), 3-nitrotyrosine, and endothelial nitric oxide synthase (eNOS) and anti-oxidant enzymes superoxide dismutase (SOD) and catalase in the hypothalamus. DOCA-salt treatment resulted in decreased catalase (95.2 ±5.6 vs. 113.8 ±17.6 mmol/min/ml, p<0.05) and SOD (4.1 ±0.4 vs. 5.9 ±0.2 U/ml, p<0.01) activities in hypothalamic homogenates of NT mice, which was prevented by ACE2 overexpression (141.8 ±9.9 vs. 142.1 ±9.2 mmol/min/ml and 5.9 ±0.3 vs. 7.9 ±0.2 U/ml, respectively). NT mice treated with DOCA-salt showed increased oxidative stress as indicated by increased expression of Nox-2 (61 ±5 % increase, n=9, p<0.001 vs. NT) and 3-nitrotyrosine (89 ±32 % increase, n=9, p<0.01 vs. NT) in the PVN which was attenuated in SA mice. Furthermore, DOCA-salt hypertension resulted in decreased phosphorylation of eNOS-ser1177 in the PVN (33 ±5 % decrease, n=9, p<0.05 vs NT) and this decrease was prevented by ACE2 overexpression. Taken together, these data provide evidence that brain ACE2 regulates the balance between NO and ROS levels, thereby preventing the development of DOCA-salt hypertension.

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Exposure to Ti4Al4V Titanium Alloy Leads to Redox Abnormalities, Oxidative Stress, and Oxidative Damage in Patients Treated for Mandible Fractures

Oxidative Medicine and Cellular Longevity ◽

10.1155/2018/3714725 ◽

2018 ◽

Vol 2018 ◽

pp. 1-10 ◽

Cited By ~ 20

Author(s):

Jan Borys ◽

Mateusz Maciejczyk ◽

Bożena Antonowicz ◽

Adam Krętowski ◽

Danuta Waszkiel ◽

...

Keyword(s):

Titanium Alloy ◽

Oxidative Damage ◽

Activity Concentration ◽

Maxillofacial Surgery ◽

Redox Balance ◽

Passive Layer ◽

Oxidative Modification ◽

Mandibular Fractures ◽

Mandible Fractures ◽

Increased Activity

Due to the high biotolerance, favourable mechanical properties, and osseointegration ability, titanium is the basic biomaterial used in maxillofacial surgery. The passive layer of titanium dioxide on the surface of the implant effectively provides anticorrosive properties, but it can be damaged, resulting in the release of titanium ions to the surrounding tissues. The aim of our work was to evaluate the influence of Ti6Al4V titanium alloy on redox balance and oxidative damage in the periosteum surrounding the titanium miniplates and screws as well as in plasma and erythrocytes of patients with mandibular fractures. The study included 31 previously implanted patients (aged 21–29) treated for mandibular fractures and 31 healthy controls. We have demonstrated increased activity/concentration of antioxidants both in the mandibular periosteum and plasma/erythrocytes of patients with titanium mandibular fixations. However, increased concentrations of the products of oxidative protein and lipid modifications were only observed in the periosteum of the study group patients. The correlation between the products of oxidative modification of the mandible and antioxidants in plasma/erythrocytes suggests a relationship between the increase of oxidative damage at the implantation site and central redox disorders in patients with titanium miniplates and screws.

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