scholarly journals Early superoxide scavenging accelerates renal microvascular rarefaction and damage in the stenotic kidney

2012 ◽  
Vol 303 (4) ◽  
pp. F576-F583 ◽  
Author(s):  
Silvia Kelsen ◽  
Xiaochen He ◽  
Alejandro R. Chade
Keyword(s):  
Oxidative Stress ◽  
Renal Injury ◽  
Ex Vivo ◽  
Early Stage ◽  
Renal Perfusion ◽  
Redox Status ◽  
Renal Tissue ◽  
Tissue Sections ◽  
And Function

Renal artery stenosis (RAS), the main cause of chronic renovascular disease (RVD), is associated with significant oxidative stress. Chronic RVD induces renal injury partly by promoting renal microvascular (MV) damage and blunting MV repair in the stenotic kidney. We tested the hypothesis that superoxide anion plays a pivotal role in MV dysfunction, reduction of MV density, and progression of renal injury in the stenotic kidney. RAS was induced in 14 domestic pigs and observed for 6 wk. Seven RAS pigs were chronically treated with the superoxide dismutase mimetic tempol (RAS+T) to reduce oxidative stress. Single-kidney hemodynamics and function were quantified in vivo using multidetector computer tomography (CT) and renal MV density was quantified ex vivo using micro-CT. Expression of angiogenic, inflammatory, and apoptotic factors was measured in renal tissue, and renal apoptosis and fibrosis were quantified in tissue sections. The degree of RAS and blood pressure were similarly increased in RAS and RAS+T. Renal blood flow (RBF) and glomerular filtration rate (GFR) were reduced in the stenotic kidney (280.1 ± 36.8 and 34.2 ± 3.1 ml/min, P < 0.05 vs. control). RAS+T kidneys showed preserved GFR (58.5 ± 6.3 ml/min, P = not significant vs. control) but a similar decreases in RBF (293.6 ± 85.2 ml/min) and further decreases in MV density compared with RAS. These changes were accompanied by blunted angiogenic signaling and increased apoptosis and fibrosis in the stenotic kidney of RAS+T compared with RAS. The current study shows that tempol administration provided limited protection to the stenotic kidney. Despite preserved GFR, renal perfusion was not improved by tempol, and MV density was further reduced compared with untreated RAS, associated with increased renal apoptosis and fibrosis. These results suggest that a tight balance of the renal redox status is necessary for a normal MV repair response to injury, at least at the early stage of RVD, and raise caution regarding antioxidant strategies in RAS.

Comparison of acute and chronic antioxidant interventions in experimental renovascular disease

2004 ◽  
Vol 286 (6) ◽  
pp. F1079-F1086 ◽  
Author(s):  
Alejandro R. Chade ◽  
James D. Krier ◽  
Martin Rodriguez-Porcel ◽  
Jerome F. Breen ◽  
Michael A. McKusick ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Tissue Injury ◽  
Ex Vivo ◽  
Renal Tissue ◽  
Renal Hemodynamics ◽  
Tissue Growth ◽  
Renovascular Disease ◽  
And Function

Reactive oxygen species (ROS) can modulate renal hemodynamics and function both directly, by leading to vasoconstriction, and indirectly, by inducing renal inflammation and tissue growth. The involvement of oxidative stress in the pathogenesis of renovascular disease (RVD) is increasingly recognized, but the relative contribution of long-term tissue injury to renal dysfunction remains unclear. We hypothesized that functional and structural alterations elicited by oxidative stress in RVD would be more effectively modulated by chronic than by acute antioxidant intervention. Renal hemodynamics and function were quantified in vivo in pigs using electron-beam computed tomography at baseline and after vasoactive challenge (ACh and sodium nitroprusside); after 12 wk of RVD (simulated by concurrent hypercholesterolemia and renal artery stenosis, n = 7); RVD acutely infused with the SOD-mimetic tempol (RVD+tempol, n = 7); RVD chronically supplemented with antioxidant vitamins C (1 g) and E (100 IU/kg; RVD+vitamins, n = 7); or control (normal, n = 7). Renal tissue was studied ex vivo using immunoblotting and immunohistochemistry. Basal renal blood flow (RBF) and glomerular filtration rate were similarly decreased in all RVD groups. ACh-stimulated RBF remained unchanged in RVD, increased in RVD+tempol, but further increased (similarly to normal) in RVD+vitamins ( P < 0.05 vs. RVD). Furthermore, RVD+vitamins also showed a decreased presence of superoxide anion, decreased NAD(P)H-oxidase and nitrotyrosine expression, increased endothelial nitric oxide synthase expression, and attenuated renal fibrosis. Chronic antioxidant intervention in early RVD improved renal hemodynamic responses more effectively than acute intervention, likely due to increased nitric oxide bioavailability and decreased structural injury. These suggest that chronic tissue changes play an important role in renal compromise mediated by oxidative stress in RVD.

Vascular responses in vivo to 8-epiPGF2α in normal and hypercholesterolemic pigs

2002 ◽  
Vol 283 (2) ◽  
pp. R303-R308 ◽  
Author(s):  
James D. Krier ◽  
Martin Rodriguez-Porcel ◽  
Patricia J. M. Best ◽  
J. Carlos Romero ◽  
Amir Lerman ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Systemic Circulation ◽  
Renal Perfusion ◽  
High Dose ◽  
Functional Responses ◽  
Vascular Effects ◽  
Prostaglandin F ◽  
And Function ◽  
Single Kidney

Hypercholesterolemia (HC) is characterized by increased circulating 8- epi-prostaglandin-F2α (isoprostane), a vasoconstrictor, marker, and mediator of increased oxidative stress, whose vascular effects might be augmented in HC. Anesthetized pigs were studied in vivo with electron beam computed tomography after a 12-wk normal ( n = 8) or HC ( n = 8) diet. Mean arterial pressure (MAP), single-kidney perfusion, and glomerular filtration rate (GFR) were quantified before and during unilateral intrarenal infusions of U46619 (10 ng · kg−1 · min−1) or isoprostane (1 μg · kg−1 · min−1). Basal renal perfusion and function were similar, and isoprostane infusion elevated its systemic levels similarly in normal and HC (333 ± 89 vs. 366 ± 48 pg/ml, respectively, P < 0.01 vs. baseline). Both drugs markedly and comparably decreased cortical perfusion and GFR in both groups, whereas medullary perfusion decreased significantly only in HC. Moreover, MAP increased significantly only in HC (+9 ± 3 and +11 ± 3 mmHg, respectively, P≤ 0.05). Hence, in HC, renal functional responses to high-dose isoprostane are largely similar to normal, but the systemic circulation exhibits augmented sensitivity to pathophysiological levels of isoprostane and U46619 , which may potentially play a role in development of hypertension and vascular injury associated with increased oxidative stress.

scholarly journals Transplanted senescent renal scattered tubular-like cells induce injury in the mouse kidney

2020 ◽  
Vol 318 (5) ◽  
pp. F1167-F1176 ◽  
Author(s):  
Seo Rin Kim ◽  
Kai Jiang ◽  
Christopher M. Ferguson ◽  
Hui Tang ◽  
Xiaojun Chen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cellular Senescence ◽  
Ex Vivo ◽  
Kidney Injury ◽  
Renal Tissue ◽  
Plasma Creatinine ◽  
Plasma Creatinine Level ◽  
Renal Markers ◽  
And Function

Cellular senescence, a permanent arrest of cell proliferation, is characterized by a senescence-associated secretory phenotype (SASP), which reinforces senescence and exerts noxious effects on adjacent cells. Recent studies have suggested that transplanting small numbers of senescent cells suffices to provoke tissue inflammation. We hypothesized that senescent cells can directly augment renal injury. Primary scattered tubular-like cells (STCs) acquired from pig kidneys were irradiated by 10 Gy of cesium radiation, and 3 wk later cells were characterized for levels of senescence and SASP markers. Control or senescent STCs were then prelabeled and injected (5 × 105 cells) into the aorta of C57BL/6J mice. Four weeks later, renal oxygenation was studied in vivo using 16.4-T magnetic resonance imaging and function by plasma creatinine level. Renal markers of SASP, fibrosis, and microvascular density were evaluated ex vivo. Per flow cytometry, irradiation induced senescence in 80–99% of STCs, which showed increased gene expression of senescence and SASP markers, senescence-associated β-galactosidase staining, and cytokine levels (especially IL-6) secreted in conditioned medium. Four weeks after injection, cells were detected engrafted in the mouse kidneys with no evidence for rejection. Plasma creatinine and renal tissue hypoxia increased in senescent compared with control cells. Senescent kidneys were more fibrotic, with fewer CD31+ endothelial cells, and showed upregulation of IL-6 gene expression. Therefore, exogenously delivered senescent renal STCs directly injure healthy mouse kidneys. Additional studies are needed to determine the role of endogenous cellular senescence in the pathogenesis of kidney injury and evaluate the utility of senolytic therapy.

scholarly journals Endothelin-A receptor blockade slows the progression of renal injury in experimental renovascular disease

2011 ◽  
Vol 301 (1) ◽  
pp. F218-F225 ◽  
Author(s):  
Silvia Kelsen ◽  
John E. Hall ◽  
Alejandro R. Chade
Keyword(s):  
Growth Factor ◽  
Renal Injury ◽  
Ex Vivo ◽  
Three Dimensional ◽  
Renal Tissue ◽  
Renal Hemodynamics ◽  
Microvascular Density ◽  
Receptor Blockade ◽  
Renovascular Disease

Endothelin (ET)-1, a potent renal vasoconstrictor with mitogenic properties, is upregulated by ischemia and has been shown to induce renal injury via the ET-A receptor. The potential role of ET-A blockade in chronic renovascular disease (RVD) has not, to our knowledge, been previously reported. We hypothesized that chronic ET-A receptor blockade would preserve renal hemodynamics and slow the progression of injury of the stenotic kidney in experimental RVD. Renal artery stenosis, a major cause of chronic RVD, was induced in 14 pigs and observed for 6 wk. In half of the pigs, chronic ET-A blockade was initiated (RVD+ET-A, 0.75 mg·kg−1·day−1) at the onset of RVD. Single-kidney renal blood flow, glomerular filtration rate, and perfusion were quantified in vivo after 6 wk using multidetector computer tomography. Renal microvascular density was quantified ex vivo using three-dimensional microcomputer tomography, and growth factors, inflammation, apoptosis, and fibrosis were determined in renal tissue. The degree of stenosis and increase in blood pressure were similar in RVD and RVD+ET-A pigs. Renal hemodynamics, function, and microvascular density were decreased in the stenotic kidney but preserved by ET-A blockade, accompanied by increased renal expression of vascular endothelial growth factor, hepatocyte growth factor, and downstream mediators such as phosphorilated-Akt, angiopoietins, and endothelial nitric oxide synthase. ET-A blockade also reduced renal apoptosis, inflammation, and glomerulosclerosis. This study shows that ET-A blockade slows the progression of renal injury in experimental RVD and preserves renal hemodynamics, function, and microvascular density in the stenotic kidney. These results support a role for ET-1/ET-A as a potential therapeutic target in chronic RVD.

Adenosine Diphosphate (ADP)-Induced ⍺-Granules Release from Platelets of Native Whole Blood Is Reduced by Ticlopidine but Not by Aspirin or Dipyridamole

1986 ◽  
Vol 56 (02) ◽  
pp. 147-150 ◽  
Author(s):  
V Pengo ◽  
M Boschello ◽  
A Marzari ◽  
M Baca ◽  
L Schivazappa ◽  
...  
Keyword(s):  
Whole Blood ◽  
Light Transmission ◽  
Ex Vivo ◽  
Early Stage ◽  
Shape Change ◽  
Adenosine Diphosphate ◽  
Dose Dependent ◽  
Plateletderived Growth Factor ◽  
Platelet Shape

SummaryA brief contact between native whole blood and ADP promotes a dose-dependent release of platelet a-granules without a fall in the platelet number. We assessed the “ex vivo” effect of three widely used antiplatelet drugs, aspirin dipyridamole and ticlopidine, on this system. Aspirin (a single 800 mg dose) and dipyridamole (300 mg/die for four days) had no effect, while ticlopidine (500 mg/die for four days) significantly reduced the a-granules release for an ADP stimulation of 0.4 (p <0.02), 1.2 (p <0.01) and 2 pM (p <0.01). No drug, however, completeley inhibits this early stage of platelet activation. The platelet release of α-granules may be related to platelet shape change of the light transmission aggregometer and may be important “in vivo” by enhancing platelet adhesiveness and by liberating the plateletderived growth factor.

scholarly journals Cyclic Voltammetry in Biological Samples: A Systematic Review of Methods and Techniques Applicable to Clinical Settings

Signals ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 138-158
Author(s):  
Hsiang-Wei Wang ◽  
Cameron Bringans ◽  
Anthony J. R. Hickey ◽  
John A. Windsor ◽  
Paul A. Kilmartin ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Systematic Review ◽  
Cyclic Voltammetry ◽  
Clinical Setting ◽  
Biological Samples ◽  
Antioxidant Status ◽  
Redox Status ◽  
Electrochemical Technique ◽  
Processing And Storage

Oxidative stress plays a pivotal role in the pathogenesis of many diseases, but there is no accurate measurement of oxidative stress or antioxidants that has utility in the clinical setting. Cyclic Voltammetry is an electrochemical technique that has been widely used for analyzing redox status in industrial and research settings. It has also recently been applied to assess the antioxidant status of in vivo biological samples. This systematic review identified 38 studies that used cyclic voltammetry to determine the change in antioxidant status in humans and animals. It focusses on the methods for sample preparation, processing and storage, experimental setup and techniques used to identify the antioxidants responsible for the voltammetric peaks. The aim is to provide key information to those intending to use cyclic voltammetry to measure antioxidants in biological samples in a clinical setting.

scholarly journals Alcohol-and-HIV-Induced Lysosomal Dysfunction Regulates Extracellular Vesicles Secretion in Vitro and in Liver-Humanized Mice

Biology ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 29
Author(s):  
Raghubendra Singh Dagur ◽  
Moses New-Aaron ◽  
Murali Ganesan ◽  
Weimin Wang ◽  
Svetlana Romanova ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Extracellular Vesicles ◽  
Treated Group ◽  
Human Hepatocytes ◽  
In Vivo Studies ◽  
People Living With Hiv ◽  
Humanized Mouse Model ◽  
And Function

Background: Alcohol abuse is common in people living with HIV-1 and dramaticallyenhances the severity of HIV-induced liver damage by inducing oxidative stress and lysosomaldysfunction in the liver cells. We hypothesize that the increased release of extracellular vesicles(EVs) in hepatocytes and liver humanized mouse model is linked to lysosome dysfunction. Methods:The study was performed on primary human hepatocytes and human hepatoma RLWXP-GFP (Huh7.5 cells stably transfected with CYP2E1 and XPack-GFP) cells and validated on ethanol-fed liverhumanizedfumarylacetoacetate hydrolase (Fah)-/-, Rag2-/-, common cytokine receptor gamma chainknockout (FRG-KO) mice. Cells and mice were infected with HIV-1ADA virus. Results: We observedan increase in the secretion of EVs associated with a decrease in lysosomal activity and expressionof lysosomal-associated membrane protein 1. Next-generation RNA sequencing of primary humanhepatocytes revealed 63 differentially expressed genes, with 13 downregulated and 50 upregulatedgenes in the alcohol–HIV-treated group. Upstream regulator analysis of differentially expressedgenes through Ingenuity Pathway Analysis identified transcriptional regulators affecting downstreamgenes associated with increased oxidative stress, lysosomal associated disease, and function andEVs biogenesis. Our in vitro findings were corroborated by in vivo studies on human hepatocytetransplantedhumanized mice, indicating that intensive EVs’ generation by human hepatocytes andtheir secretion to serum was associated with increased oxidative stress and reduction in lysosomalactivities triggered by HIV infection and ethanol diet. Conclusion: HIV-and-ethanol-metabolisminducedEVs release is tightly controlled by lysosome status in hepatocytes and participates in thedevelopment of double-insult-induced liver injury.

scholarly journals NAC and Vitamin D Restore CNS Glutathione in Endotoxin-Sensitized Neonatal Hypoxic-Ischemic Rats

Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 489
Author(s):  
Lauren E. Adams ◽  
Hunter G. Moss ◽  
Danielle W. Lowe ◽  
Truman Brown ◽  
Donald B. Wiest ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Vitamin D ◽  
Redox Status ◽  
Therapeutic Window ◽  
Post Injury ◽  
Artery Ligation ◽  
Cellular Redox ◽  
Carotid Artery Ligation ◽  
Drug Concentrations

Therapeutic hypothermia does not improve outcomes in neonatal hypoxia ischemia (HI) complicated by perinatal infection, due to well-described, pre-existing oxidative stress and neuroinflammation that shorten the therapeutic window. For effective neuroprotection post-injury, we must first define and then target CNS metabolomic changes immediately after endotoxin-sensitized HI (LPS-HI). We hypothesized that LPS-HI would acutely deplete reduced glutathione (GSH), indicating overwhelming oxidative stress in spite of hypothermia treatment in neonatal rats. Post-natal day 7 rats were randomized to sham ligation, or severe LPS-HI (0.5 mg/kg 4 h before right carotid artery ligation, 90 min 8% O2), followed by hypothermia alone or with N-acetylcysteine (25 mg/kg) and vitamin D (1,25(OH)2D3, 0.05 μg/kg) (NVD). We quantified in vivo CNS metabolites by serial 7T MR Spectroscopy before, immediately after LPS-HI, and after treatment, along with terminal plasma drug concentrations. GSH was significantly decreased in all LPS-HI rats compared with baseline and sham controls. Two hours of hypothermia alone did not improve GSH and allowed glutamate + glutamine (GLX) to increase. Within 1 h of administration, NVD increased GSH close to baseline and suppressed GLX. The combination of NVD with hypothermia rapidly improved cellular redox status after LPS-HI, potentially inhibiting important secondary injury cascades and allowing more time for hypothermic neuroprotection.

Resolution of renal inflammation: a new role for NF-κB1 (p50) in inflammatory kidney diseases

2009 ◽  
Vol 297 (2) ◽  
pp. F429-F439 ◽  
Author(s):  
Ulf Panzer ◽  
Oliver M. Steinmetz ◽  
Jan-Eric Turner ◽  
Catherine Meyer-Schwesinger ◽  
Claudia von Ruffer ◽  
...  
Keyword(s):  
Tissue Injury ◽  
Kidney Diseases ◽  
Renal Tissue ◽  
Induction Phase ◽  
Nuclear Compartment ◽  
Renal Inflammation ◽  
Proinflammatory Gene ◽  
And Function ◽  
Proinflammatory Gene Expression

In renal tissue injury, activation of the transcription factor NF-κB has a central role in the induction of proinflammatory gene expression, which are involved in the development of progressive renal inflammatory disease. The function of NF-κB during the switch from the inflammatory process toward resolution, however, is largely unknown. Therefore, we assessed the time-dependent activation and function of NF-κB in two different models of acute nephritis. Our experiments demonstrate a biphasic activation of NF-κB in the anti-Thy-1 model of glomerulonephritis in rats and the LPS-induced nephritis in mice, with a first peak during the induction phase and a second peak during the resolution period. After induction of glomerular immune injury in rats, predominantly NF-κB p65/p50 heterodimer complexes are shifted to the nucleus whereas during the resolution phase predominantly p50 homodimers could be demonstrated in the nuclear compartment. In addition, we could demonstrate that p50 protein plays a pivotal role in the resolution of LPS-induced renal inflammation since NF-κB p50 knockout mice demonstrate significantly higher chemokine expression, prolonged renal inflammatory cell infiltration with consecutive tissue injury, and reduced survival. In conclusion, our studies indicate that NF-κB subunit p50 proteins have critical in vivo functions in immunologically mediated renal disease by downregulating inflammation during the resolution period.

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