scholarly journals The role of renal superoxide dismutase (sod) on the slow pressor effects of angiotensin ii

2004 ◽  
Vol 17 (5) ◽  
pp. S20
Author(s):  
W WELCH
Keyword(s):  
Superoxide Dismutase ◽  
Angiotensin Ii

scholarly journals Deletion of Superoxide Dismutase 1 Blunted Inflammatory Aortic Remodeling in Hypertensive Mice under Angiotensin II Infusion

Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 471
Author(s):  
Yasunaga Shiraishi ◽  
Norio Ishigami ◽  
Takehiko Kujiraoka ◽  
Atsushi Sato ◽  
Masanori Fujita ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Angiotensin Ii ◽  
Superoxide Dismutase 1 ◽  
Superoxide Anions ◽  
Vascular Hypertrophy ◽  
Blood Pressures ◽  
Aortic Remodeling ◽  
Deficient Mice ◽  
Cytosolic Sod

Superoxide dismutase (SOD) is an enzyme that catalyzes the dismutation of two superoxide anions (O2·−) into hydrogen peroxide (H2O2) and oxygen (O2) and is generally known to protect against oxidative stress. Angiotensin II (AngII) causes vascular hypertrophic remodeling which is associated with H2O2 generation. The aim of this study is to investigate the role of cytosolic SOD (SOD1) in AngII-induced vascular hypertrophy. We employed C57/BL6 mice (WT) and SOD1 deficient mice (SOD1−/−) with the same background. They received a continuous infusion of saline or AngII (3.2 mg/kg/day) for seven days. The blood pressures were equally elevated at 1.5 times with AngII, however, vascular hypertrophy was blunted in SOD1−/− mice compared to WT mice (WT mice 91.9 ± 1.13 µm versus SOD1−/− mice 68.4 ± 1.41 µm p < 0.001). The elevation of aortic interleukin 6 (IL-6) and phosphorylation of pro-inflammatory STAT3 due to AngII were also blunted in SOD1−/− mice’s aortas. In cultured rat vascular smooth muscle cells (VSMCs), reducing expression of SOD1 with siRNA decreased AngII induced IL-6 release as well as phosphorylation of STAT3. Pre-incubation with polyethylene glycol (PEG)-catalase also attenuated phosphorylation of STAT3 due to AngII. These results indicate that SOD1 in VSMCs plays a role in vascular hypertrophy due to increased inflammation caused by AngII, probably via the production of cytosolic H2O2.

Abstract 15061: Essential Hypertension is Linked to Acetylation of Mitochondrial Superoxide Dismutase and Deacetylation Mimetic Mutation of Lysine 68 to Arginine Protects From Oxidative Stress and Hypertension

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Anna Dikalova ◽  
Liliya Tkachuk ◽  
Marcos G Lopez ◽  
Frederic T Billings ◽  
Sergey Dikalov
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Superoxide Dismutase ◽  
Essential Hypertension ◽  
Angiotensin Ii ◽  
Wild Type ◽  
Mitochondrial Superoxide ◽  
Induced Hypertension ◽  
Lysine Residues

Almost one-half of adults have hypertension, and blood pressure is poorly controlled in a third of patients despite use of multiple drugs, likely due to mechanisms contributing to blood pressure elevation that are not affected by current treatments. Hypertension is linked to oxidative stress; however, common antioxidants are ineffective. We found that hypertension is associated with inactivation of key mitochondrial antioxidant, superoxide dismutase 2 (SOD2), due to acetylation of lysine residues at the catalytic center. The role of specific SOD2 lysine residues in hypertension, however, has not been defined. Hypothesis: We proposed that inactivation of key intrinsic antioxidant, SOD2, in hypertension is linked to acetylation of Lysine 68, and mutation of K68 to Arginine mimics SOD2 deacetylation, inhibits vascular oxidative stress and attenuates angiotensin II-induced hypertension. To test this hypothesis, we have investigated SOD2 acetylation in arterioles from patients with essential hypertension and developed a new deacetylation mimic SOD2 mutant K68R mice (SOD2-K68R). Western blot of arterioles isolated from human mediastinal fat showed 3-fold increase in SOD2 acetylation in hypertensive patients compared with normotensive subjects while SOD2 levels were not affected. To define the functional significance of K68 acetylation we performed studies in vivo in SOD2-K68R mice using angiotensin II model of vascular dysfunction and hypertension. Angiotensin II infusion in wild-type C57Bl/6J mice induced vascular inflammation and oxidative stress, and increased blood pressure to 160 mm Hg. Mutation of Lysine 68 to Arginine in SOD2-K68R mice completely prevented the increase in mitochondrial superoxide and significantly attenuated the angiotensin II induced hypertension (135 mm Hg). Angiotensin II and TNFα co-operatively induce SOD2 acetylation and hypertension. Treatment of wild-type aortas with angiotensin II and TNFα in organoid culture increased mitochondrial superoxide by 2-fold which was completely prevented in aortas isolated from SOD2-K68R mice. Conclusions: These data support an important role of SOD2-K68 acetylation in hypertension and targeting Sirt3-mediated deacetylation of SOD2 may have therapeutic potential.

Abstract P080: Mutation Of Lysine 68 To Arginine Mimics Deacetylation Of Mitochondrial Superoxide Dismutase, Protects From Vascular Oxidative Stress And Attenuates Angiotensin II-Induced Hypertension

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Anna Dikalova ◽  
Liliya Tkachuk ◽  
Marcos G Lopez ◽  
Frederic T Billings ◽  
Sergey I Dikalov
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Superoxide Dismutase ◽  
Angiotensin Ii ◽  
Wild Type ◽  
Mitochondrial Superoxide ◽  
Induced Hypertension ◽  
Lysine Residues ◽  
Vascular Oxidative Stress

By recent guidelines, almost one-half of adults have hypertension, and blood pressure is poorly controlled in a third of patients despite use of multiple drugs, likely due to mechanisms contributing to blood pressure elevation that are not affected by current treatments. Hypertension is linked to oxidative stress; however, common antioxidants are ineffective. We found that hypertension is associated with inactivation of key mitochondrial antioxidant, superoxide dismutase 2 (SOD2), due to acetylation of lysine residues at the catalytic center. The role of specific SOD2 lysine residues in hypertension, however, has not been defined. We proposed that inactivation of key intrinsic antioxidant, SOD2, in hypertension is linked to acetylation of Lysine 68, and mutation of K68 to Arginine mimics SOD2 deacetylation, inhibits vascular oxidative stress and attenuates angiotensin II-induced hypertension. To test this hypothesis, we have investigated SOD2 acetylation in arterioles from patients with essential hypertension and developed a new deacetylation mimic SOD2 mutant K68R mice (SOD2-K68R). Western blot analysis of arterioles isolated from human mediastinal fat showed 3-fold increase in SOD2 acetylation in hypertensive patients compared with normotensive subjects while SOD2 levels were not affected. To define the functional significance of K68 acetylation we performed studies in vivo in SOD2-K68R mice using angiotensin II model of vascular dysfunction and hypertension. Angiotensin II infusion in wild-type C57Bl/6J mice induced vascular inflammation and oxidative stress, and increased blood pressure to 160 mm Hg. Mutation of Lysine 68 to Arginine in SOD2-K68R mice completely prevented the increase in mitochondrial superoxide and significantly attenuated the angiotensin II induced hypertension (135 mm Hg). Angiotensin II and TNFα co-operatively induce SOD2 acetylation and hypertension. Treatment of wild-type aortas with angiotensin II and TNFα in organoid culture increased mitochondrial superoxide by 2-fold which was completely prevented in aortas isolated from SOD2-K68R mice. These data support an important role of SOD2-K68 acetylation in hypertension, and strategies to reduce mitochondrial acetylation may have therapeutic potential.

ACE2/Angiotensin-(1-7)/Mas Receptor Axis in Human Cancer: Potential Role for Pediatric Tumors

2020 ◽  
Vol 21 (9) ◽  
pp. 892-901 ◽  
Author(s):  
Ana Luiza Ataide Carneiro de Paula Gonzaga ◽  
Vitória Andrade Palmeira ◽  
Thomas Felipe Silva Ribeiro ◽  
Larissa Braga Costa ◽  
Karla Emília de Sá Rodrigues ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Angiotensin Ii ◽  
Pediatric Cancer ◽  
Pediatric Patients ◽  
Human Cancer ◽  
Experimental Studies ◽  
At1 Receptor ◽  
Pediatric Tumors ◽  
Mas Receptor

Background: Pediatric tumors remain the highest cause of death in developed countries. Research on novel therapeutic strategies with lesser side effects is of utmost importance. In this scenario, the role of Renin-Angiotensin System (RAS) axes, the classical one formed by angiotensinconverting enzyme (ACE), Angiotensin II and AT1 receptor and the alternative axis composed by ACE2, Angiotensin-(1-7) and Mas receptor, have been investigated in cancer. Objective: This review aimed to summarize the pathophysiological role of RAS in cancer, evidence for anti-tumor effects of ACE2/Angiotensin-(1-7)/Mas receptor axis and future therapeutic perspectives for pediatric cancer. Methods: Pubmed, Scopus and Scielo were searched in regard to RAS molecules in human cancer and pediatric patients. The search terms were “RAS”, “ACE”, “Angiotensin-(1-7)”, “ACE2”, “Angiotensin II”, “AT1 receptor”, “Mas receptor”, “Pediatric”, “Cancer”. Results: Experimental studies have shown that Angiotensin-(1-7) inhibits the growth of tumor cells and reduces local inflammation and angiogenesis in several types of cancer. Clinical trials with Angiotensin-( 1-7) or TXA127, a pharmaceutical grade formulation of the naturally occurring peptide, have reported promising findings, but not enough to recommend medical use in human cancer. In regard to pediatric cancer, only three articles that marginally investigated RAS components were found and none of them evaluated molecules of the alternative RAS axis. Conclusion: Despite the potential applicability of Angiotensin-(1-7) in pediatric tumors, the role of this molecule was never tested. Further clinical trials are necessary, also including pediatric patients, to confirm safety and efficiency and to define therapeutic targets.

Anti-Hypertensive Potential and Epigenetics of Angiotensin II type 2 Receptor (AT2R)

2020 ◽  
Vol 16 ◽  
Author(s):  
Mayank Chaudhary
Keyword(s):  
Blood Pressure ◽  
Angiotensin Ii ◽  
Renin Angiotensin System ◽  
Blood Pressure Regulation ◽  
Biologically Active ◽  
Pressure Regulation ◽  
Tissue Remodelling ◽  
Critical Pathway

Background:: Renin angiotensin system (RAS) is a critical pathway involved in blood pressure regulation. Octapeptide, angiotensin II (Ang aII), is biologically active compound of RAS pathway which mediates its action by binding to either angiotensin II type 1 receptor (AT1R) or angiotensin II type 2 receptor (AT2R). Binding of Ang II to AT1R facilitates blood pressure regulation whereas AT2R is primarily involved in wound healing and tissue remodelling. Objective:: Recent studies have highlighted additional role of AT2R to counter balance detrimental effects of AT1R. Activation of angiotensin II type 2 receptor using AT2R agonist has shown effect on natriuresis and release of nitric oxide. Additionally, AT2R activation has been found to inhibit angiotensin converting enzyme (ACE) and enhance angiotensin receptor blocker (ARB) activity. These findings highlight the potential of AT2R as novel therapeutic target against hypertension. Conclusion:: The potential role of AT2R highlights the importance of exploring additional mechanisms that might be crucial for AT2R expression. Epigenetic mechanisms including DNA methylation and histone modification have been explored vastly with relation to cancer but role of such mechanisms on expression of AT2R has recently gained interest.

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