scholarly journals The NADPH Oxidase Isoform 1 Contributes to Angiotensin II-Mediated DNA Damage in the Kidney

Antioxidants ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 586
Author(s):  
Anna Zimnol ◽  
Nora Spicker ◽  
Ronja Balhorn ◽  
Katrin Schröder ◽  
Nicole Schupp
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Dna Damage ◽  
Angiotensin Ii ◽  
Knockout Mice ◽  
Dna Lesions ◽  
Mouse Strains ◽  
Nadph Oxidases ◽  
Systemic Oxidative Stress ◽  
The Impact

In higher concentrations, the blood pressure regulating hormone angiotensin II leads to vasoconstriction, hypertension, and oxidative stress by activating NADPH oxidases which are a major enzymatic source of reactive oxygen species (ROS). With the help of knockout animals, the impact of the three predominant NADPH oxidases present in the kidney, i.e., Nox1, Nox2 and Nox4 on angiotensin II-induced oxidative damage was studied. Male wildtype (WT) C57BL/6 mice, Nox1-, Nox2- and Nox4-deficient mice were equipped with osmotic minipumps, delivering either vehicle (PBS) or angiotensin II, for 28 days. Angiotensin II increased blood pressure and urinary albumin levels significantly in all treated mouse strains. In Nox1 knockout mice these increases were significantly lower than in WT, or Nox2 knockout mice. In WT mice, angiotensin II also raised systemic oxidative stress, ROS formation and DNA lesions in the kidney. A local significantly increased ROS production was also found in Nox2 and Nox4 knockout mice but not in Nox1 knockout mice who further had significantly lower systemic oxidative stress and DNA damage than WT animals. Nox2 and Nox4 knockout mice had increased basal DNA damage, concealing possible angiotensin II-induced increases. In conclusion, in the kidney, Nox1 seemed to play a role in angiotensin II-induced DNA damage.

Angiotensin II type 1a receptor-deficient mice develop angiotensin II-induced oxidative stress and DNA damage without blood pressure increase

2017 ◽  
Vol 313 (6) ◽  
pp. F1264-F1273 ◽  
Author(s):  
Anna Zimnol ◽  
Kerstin Amann ◽  
Philipp Mandel ◽  
Christina Hartmann ◽  
Nicole Schupp
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Dna Damage ◽  
Angiotensin Ii ◽  
Systolic Pressure ◽  
Wild Type ◽  
Concurrent Administration ◽  
Increased Risk ◽  
Genomic Damage ◽  
Deficient Mice

Hypertensive patients have an increased risk of developing kidney cancer. We have shown in vivo that besides elevating blood pressure, angiotensin II causes DNA damage dose dependently. Here, the role of blood pressure in the formation of DNA damage is studied. Mice lacking one of the two murine angiotensin II type 1 receptor (AT1R) subtypes, AT1aR, were equipped with osmotic minipumps, delivering angiotensin II during 28 days. Parameters of oxidative stress and DNA damage of kidneys and hearts of AT1aR-knockout mice were compared with wild-type (C57BL/6) mice receiving angiotensin II, and additionally, with wild-type mice treated with candesartan, an antagonist of both AT1R subtypes. In wild-type mice, angiotensin II induced hypertension, reduced kidney function, and led to a significant formation of reactive oxygen species (ROS). Furthermore, genomic damage was markedly increased in this group. All these responses to angiotensin II could be attenuated by concurrent administration of candesartan. In AT1aR-deficient mice treated with angiotensin II, systolic pressure was not increased, and renal function was not affected. However, angiotensin II still led to an increase of ROS in kidneys and hearts of these animals. Additionally, genomic damage in the form of double-strand breaks was significantly induced in kidneys of AT1aR-deficient mice. Our results show that angiotensin II induced ROS production and DNA damage even without the presence of AT1aR and independently of blood pressure changes.

scholarly journals ‘Liver let die’: oxidative DNA damage and hepatotropic viruses

2014 ◽  
Vol 95 (5) ◽  
pp. 991-1004 ◽  
Author(s):  
Martin R. Higgs ◽  
Philippe Chouteau ◽  
Hervé Lerat
Keyword(s):  
Oxidative Stress ◽  
Dna Damage ◽  
Cellular Response ◽  
Oxidative Dna Damage ◽  
Molecular Mechanisms ◽  
Large Body ◽  
Clinical Importance ◽  
Dna Lesions ◽  
Chronic Infections ◽  
The Impact

Chronic infections by the hepatotropic viruses hepatitis B virus (HBV) and hepatitis C virus (HCV) are major risk factors for the development of hepatocellular carcinoma (HCC). It is estimated that more than 700 000 individuals per year die from HCC, and around 80 % of HCC is attributable to HBV or HCV infection. Despite the clear clinical importance of virus-associated HCC, the underlying molecular mechanisms remain largely elusive. Oxidative stress, in particular DNA lesions associated with oxidative damage, play a major contributory role in carcinogenesis, and are strongly linked to the development of many cancers, including HCC. A large body of evidence demonstrates that both HBV and HCV induce hepatic oxidative stress, with increased oxidative DNA damage being observed both in infected individuals and in murine models of infection. Here, we review the impact of HBV and HCV on the incidence and repair of oxidative DNA damage. We begin by giving a brief overview of oxidative stress and the repair of DNA lesions induced by oxidative stress. We then review in detail the evidence surrounding the mechanisms by which both viruses stimulate oxidative stress, before focusing on how the viral proteins themselves may perturb the cellular response to oxidative DNA damage, impacting upon genome stability and thus hepatocarcinogenesis.

scholarly journals Deletion of proton-sensing receptor GPR4 associates with lower blood pressure and lower binding of angiotensin II receptor in SFO

2016 ◽  
Vol 311 (6) ◽  
pp. F1260-F1266 ◽  
Author(s):  
Xuming Sun ◽  
Ellen Tommasi ◽  
Doris Molina ◽  
Renu Sah ◽  
K. Bridget Brosnihan ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Angiotensin Ii ◽  
Fractional Excretion ◽  
Urine Osmolality ◽  
Brain Regions ◽  
Lower Blood Pressure ◽  
Angiotensin Ii Receptor ◽  
Lower Blood ◽  
Fractional Excretion Of Sodium ◽  
The Impact

Diets rich in grains and meat and low in fruits and vegetables (acid-producing diets) associate with incident hypertension, whereas vegetarian diets associate with lower blood pressure (BP). However, the pathways that sense and mediate the effects of acid-producing diets on BP are unknown. Here, we examined the impact of the deletion of an acid sensor GPR4 on BP. GPR4 is a proton-sensing G protein-coupled receptor and an acid sensor in brain, kidney, and blood vessels. We found that GPR4 mRNA was higher in subfornical organ (SFO) than other brain regions. GPR4 protein was abundant in SFO and present in capillaries throughout the brain. Since SFO partakes in BP regulation through the renin-angiotensin system (RAS), we measured BP in GPR4−/− and GPR4+/+ mice and found that GPR4 deletion associated with lower systolic BP: 87 ± 1 mmHg in GPR4−/− ( n = 35) vs. 99 ± 2 mmHg ( n = 29) in GPR4+/+; P < 0.0001, irrespective of age and sex. Angiotensin II receptors detected by 125I-Sarthran binding were lower in GPR4−/− than GPR4+/+ mice in SFO and in paraventricular nucleus of hypothalamus. Circulating angiotensin peptides were comparable in GPR4−/− and GPR4+/+ mice, as were water intake and excretion, serum and urine osmolality, and fractional excretion of sodium, potassium, or chloride. A mild metabolic acidosis present in GPR4−/− mice did not associate with elevated BP, implying that deficiency of GPR4 may preclude the effect of chronic acidosis on BP. Collectively, these results posit the acid sensor GPR4 as a novel component of central BP control through interactions with the RAS.

scholarly journals A Subpressor Dose of Angiotensin II Elevates Blood Pressure in a Normotensive Rat Model by Oxidative Stress

2015 ◽  
pp. 153-159 ◽  
Author(s):  
M. M. GOVENDER ◽  
A. NADAR
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Angiotensin Ii ◽  
Mrna Expression ◽  
Rat Model ◽  
Wistar Rat ◽  
Control Group ◽  
Sod Activity ◽  
Male Wistar Rats ◽  
Experimental Group

Oxidative stress is an imbalance between free radicals and antioxidants, and is an important etiological factor in the development of hypertension. Recent experimental evidence suggests that subpressor doses of angiotensin II elevate oxidative stress and blood pressure. We aimed to investigate the oxidative stress related mechanism by which a subpressor dose of angiotensin II induces hypertension in a normotensive rat model. Normotensive male Wistar rats were infused with a subpressor dose of angiotensin II for 28 days. The control group was sham operated and infused with saline only. Plasma angiotensin II and H2O2 levels, whole-blood glutathione peroxidase, and AT-1a, Cu/Zn SOD, and p22phox mRNA expression in the aorta was assessed. Systolic and diastolic blood pressures were elevated in the experimental group. There was no change in angiotensin II levels, but a significant increase in AT-1a mRNA expression was found in the experimental group. mRNA expression of p22phox was increased significantly and Cu/Zn SOD decreased significantly in the experimental group. There was no significant change to the H2O2 and GPx levels. Angiotensin II manipulates the free radical-antioxidant balance in the vasculature by selectively increasing O2− production and decreasing SOD activity and causes an oxidative stress induced elevation in blood pressure in the Wistar rat.

scholarly journals A multibiomarker approach in rats to assess the impact of pollution on Sinos River, Southern Brazil

2010 ◽  
Vol 70 (4 suppl) ◽  
pp. 1223-1230 ◽  
Author(s):  
C. Rechenmacher ◽  
AM. Siebel ◽  
A. Goldoni ◽  
CR. Klauck ◽  
T. Sartori ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Water Quality ◽  
Dna Damage ◽  
Quality Analysis ◽  
Microbiological Analysis ◽  
Southern Brazil ◽  
Anthropogenic Contamination ◽  
Water Analyses ◽  
The Impact ◽  
The Relationship

The aim of this study was to determine the feasibility of combining water quality analysis with different biomarkers to characterise the relationship between anthropogenic contamination and biotic response in the Sinos River, southern Brazil. Wistar rats were studied using three biomarkers combined with physical, chemical and microbiological analysis to assess the effects of pollution at four sampling sites. The induction of oxidative stress was quantified by MDA levels in peripheral blood, lymphocyte DNA damage was determined using the comet assay, and histopathological changes were analysed in the liver. After sampling, animals were allowed to drink the river water during a 48 hours period. No increase in oxidative stress and DNA damage was observed. However, liver damage was observed in the animals exposed to water samples, indicating that the Sinos River is contaminated with hepatotoxic substances. Water analyses confirmed that water quality decreased downriver.

Dysregulation of X-Ray Repair Cross Complementing 4 Expression in the Eutopic Endometrium of Women with Endometriosis

Reproduction ◽  
2022 ◽  
Author(s):  
Kashmira Bane ◽  
Junita Desouza ◽  
Asma Rojewale ◽  
Rajendra Katkam ◽  
Gwendolyn Fernandes ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Dna Damage ◽  
Critical Role ◽  
Dna Lesions ◽  
Dna Breaks ◽  
Eutopic Endometrium ◽  
Nhej Pathway ◽  
X Ray ◽  
Protein Levels ◽  
Ishikawa Cells

Recent data suggest that the DNA damage response (DDR) is altered in the eutopic endometrium (EE) of women with endometriosis and this probably ensues in response to higher DNA damage encountered by the EE in endometriosis. DDR operates in a tissue-specific manner and involves different pathways depending on the type of DNA lesions. Among these pathways, the non-homologous end joining (NHEJ) pathway plays a critical role in the repair of double-stranded DNA breaks. The present study was undertaken to explore whether NHEJ is affected in the EE of women with endometriosis. Towards this, we focused on the X-Ray Repair Cross-Complementing 4 (XRCC4) protein, one of the core components of the NHEJ pathway. Endometrial XRCC4 protein levels in the mid-proliferative phase were found significantly (p<0.05) downregulated in women with endometriosis, compared to control women. Investigation of a microarray-based largest dataset in the GEO database (GSE51981) revealed a similar trend at the transcript level in the EE of women with endometriosis, compared to control women. Further in-vitro studies were undertaken to explore the effects of H2O2-induced oxidative stress on DNA damage, as assessed by γ-H2AFX and 8-hydroxy-2’-deoxyguanosine (8-OHdG) immunolocalization, and XRCC4 protein levels in endometrial stromal (ThESCs) and epithelial (Ishikawa) cells. A significant decrease in XRCC4 protein levels and significantly higher localization of γ-H2AFX and 8-OHdG were evident in ThESCs and Ishikawa cells experiencing oxidative stress. Overall, the study demonstrates that the endometrial XRCC4 expression is dysregulated in women with endometriosis and this could be due to higher oxidative stress in endometriosis.

Abstract 598: Deletion of Microsomal PGE Synthase-1 Decreases Oxidative Stress and Protects Against Abdominal Aortic Aneurysm Formation in Angiotensin II-Infused Mice

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Miao Wang ◽  
Jane Stubbe ◽  
Eric Lee ◽  
Wenliang Song ◽  
Emanuela Ricciotti ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Angiotensin Ii ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Aortic Aneurysms ◽  
Ang Ii ◽  
Abdominal Aortic ◽  
Density Lipoprotein Receptor ◽  
The Impact

Microsomal (m) prostaglandin (PG) E 2 synthase(S)-1, an enzyme that catalyzes the isomerization of the cyclooxygenase (COX) product, PGH 2 , into PGE 2 , is a major source of PGE 2 in vivo . mPGES-1 deletion in mice was found to modulate experimentally evoked pain and inflammation and atherogenesis is retarded in mPGES-1 knockout (KO) mice. The impact of mPGES-1 deletion on formation of angiotensin II (Ang II)-induced abdominal aortic aneurysms (AAA) was studied in mice lacking the low density lipoprotein receptor (LDLR −/− ). AngII infusion increased aortic macrophage recruitment and nitrotyrosine staining while upregulating both mPGES-1 and COX-2 and urinary excretion of the major metabolite of PGE 2 (PGE-M). Deletion of mPGES-1 decreased both the incidence and severity of AAA and depressed excretion of both PGE-M and 8, 12-iso-iPF 2a -VI, which reflects lipid peroxidation in vivo . While Ang II infusion augmented prostaglandin biosynthesis, deletion of mPGES-1 resulted in rediversion to PGD 2 , reflected by its major urinary metabolite. However, deletion of the PGD 2 receptor, DP1, did not affect AAA in Ang II infused LDLR −/− mice. These observations indicate that deletion of mPGES-1 protects against AAA formation by AngII in hyperlipidemic mice, perhaps by decreasing oxidative stress. Inhibition of mPGES-1 may represent an effective treatment to limit aneurysm occurrence and expansion.

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