scholarly journals Persistent oxidative stress following renal ischemia-reperfusion injury increases ANG II hemodynamic and fibrotic activity

2012 ◽  
Vol 302 (11) ◽  
pp. F1494-F1502 ◽  
Author(s):  
David P. Basile ◽  
Ellen C. Leonard ◽  
Alisa G. Beal ◽  
Devin Schleuter ◽  
Jessica Friedrich

ANG II is a potent renal vasoconstrictor and profibrotic factor and its activity is enhanced by oxidative stress. We sought to determine whether renal oxidative stress was persistent following recovery from acute kidney injury (AKI) induced by ischemia-reperfusion (I/R) injury in rats and whether this resulted in increased ANG II sensitivity. Rats were allowed to recover from bilateral renal I/R injury for 5 wk and renal blood flow responses were measured. Post-AKI rats showed significantly enhanced renal vasoconstrictor responses to ANG II relative to sham-operated controls and treatment of AKI rats with apocynin (15 mM, in the drinking water) normalized these responses. Recovery from AKI for 5 wk resulted in sustained oxidant stress as indicated by increased dihydroethidium incorporation in renal tissue slices and was normalized in apocynin-treated rats. Surprisingly, the renal mRNA expression for common NADPH oxidase subunits was not altered in kidneys following recovery from AKI; however, mRNA screening using PCR arrays suggested that post-AKI rats had decreased renal Gpx3 mRNA and an increased expression other prooxidant genes such as lactoperoxidase, myeloperoxidase, and dual oxidase-1. When rats were infused for 7 days with ANG II (100 ng·kg−1·min−1), renal fibrosis was not apparent in sham-operated control rats, but it was enhanced in post-AKI rats. The profibrotic response was significantly attenuated in rats treated with apocynin. These data suggest that there is sustained renal oxidant stress following recovery from AKI that alters both renal hemodynamic and fibrotic responses to ANG II, and may contribute to the transition to chronic kidney disease following AKI.

2015 ◽  
Vol 3 (3) ◽  
pp. 116-125 ◽  
Author(s):  
Bulent Ergin ◽  
Coert J. Zuurbier ◽  
Rick Bezemer ◽  
Asli Kandil ◽  
Emre Almac ◽  
...  

AbstractBackground and objectives: Acute kidney injury (AKI) is a clinical condition associated with a degree of morbidity and mortality despite supportive care, and ischemia/reperfusion injury (I/R) is one of the main causes of AKI. The pathophysiology of I/R injury is a complex cascade of events including the release of free oxygen radicals followed by damage to proteins, lipids, mitochondria, and deranged tissue oxygenation. In this study, we investigated whether the antioxidant ascorbic acid would be able to largely prevent oxidative stress and consequently, reduce I/R-related injury to the kidneys in terms of oxygenation, inflammation, and renal failure. Materials and methods: Rats were divided into three groups (n = 6/group): (1) a time control group; (2) a group subjected to renal ischemia for 60 min by high aortic occlusion followed by 2 h of reperfusion (I/R); and (3) a group subjected to I/R and treated with an i.v. 100 mg/kg bolus ascorbic acid 15 min before ischemia and continuous infusion of 50 mg/kg/hour for 2 h during reperfusion (I/R + AA). We measured renal tissue oxidative stress, microvascular oxygenation, renal oxygen delivery and consumption, and renal expression of inflammatory and injury markers. Results: We demonstrated that aortic clamping and release resulted in increased oxidative stress and inflammation that was associated with a significant fall in systemic and renal hemodynamics and oxygenation parameters. The treatment of ascorbic acid completely abrogated oxidative stress and inflammatory parameters. However, it only partly improved microcirculatory oxygenation and was without any effect on anuria. Conclusion: The ascorbic acid treatment partly improves microcirculatory oxygenation and prevents oxidative stress without restoring urine output in a severe I/R model of AKI.


2021 ◽  
Author(s):  
Priyanka N Prem ◽  
Gino A Kurian

Abstract Purpose Renal ischemic reperfusion (IR) injury is one of the major source of mortality and morbidity associated with acute kidney injury (AKI). Several flavonoids have shown to be renal protective against many nephrotoxic agents causing AKI. Fisetin, a promising flavonoid, is effective in the management of septic AKI, expected to ameliorate renal IR injury. Present study aim to generate evidence for fisetin mediated renal protection against IR injury Methodology: Male wistar rats of 200-250 g subjected to IR protocol by performing bilateral clamping for 45 minutes and reperfusion for 24 hours. Fisetin administrated 30 minutes ( 20 mg/kg b.wt, ip) before the surgery. Renal injury was evaluated by measuring the biomarkers in plasma, examining the ultrastructure of kidney and analyzing the apoptotic changes. Oxidative stress, antioxidant levels and mitochondrial function were analysed in the renal tissue. Results Fisetin administration significantly reduced the renal damages associated with IR, by improving estimated glomerular filtration rate (eGFR: IR-0.35 ml/min, F_IR-9.03 ml/min), reducing plasma creatinine level (IR-2.2 mg/dl, F_IR-0.92 mg/dl) and lowering urinary albumin/creatinine ratio (IR- 6.09 F_IR-2.16), caspase activity, decreased DNA fragmentation and reduced tubular injury score (IR- 11 F_IR-6.5). At cellular level, fisetin significantly reduced renal oxidative stress and augmented the antioxidant levels. Fisetin found to preserve mitochondrial electron transport chain activities and improved the ATP producing capacity in the renal tissue upon IR injury. Conclusion fisetin pre-treatment attenuate renal IR injury by improving the renal function, reducing the renal injury mediated by apoptosis, reducing free radical release, and augmenting mitochondrial function.


2021 ◽  
Vol 16 (1) ◽  
pp. 537-543
Author(s):  
Mei Zhang ◽  
Jing Yuan ◽  
Rong Dong ◽  
Jingjing Da ◽  
Qian Li ◽  
...  

Abstract Background Hyperhomocysteinemia (HHcy) plays an important role in the progression of many kidney diseases; however, the relationship between HHcy and ischemia-reperfusion injury (IRI)-induced acute kidney injury (IRI-induced AKI) is far from clear. In this study, we try to investigate the effect and possible mechanisms of HHcy on IRI-induced AKI. Methods Twenty C57/BL6 mice were reared with a regular diet or high methionine diet for 2 weeks (to generate HHcy mice); after that, mice were subgrouped to receive sham operation or ischemia-reperfusion surgery. Twenty four hour after reperfusion, serum creatinine, blood urea nitrogen, and Malondialdehyde (MDA) were measured. H&E staining for tubular injury, western blot for γH2AX, JNK, p-JNK, and cleaved caspase 3, and TUNEL assay for tubular cell apoptosis were also performed. Results Our results showed that HHcy did not influence the renal function and histological structure, as well as the levels of MDA, γH2AX, JNK, p-JNK, and tubular cell apoptosis in control mice. However, in IRI-induced AKI mice, HHcy caused severer renal dysfunction and tubular injury, higher levels of oxidative stress, DNA damage, JNK pathway activation, and tubular cell apoptosis. Conclusion Our results demonstrated that HHcy could exacerbate IRI-induced AKI, which may be achieved through promoting oxidative stress, DNA damage, JNK pathway activation, and consequent apoptosis.


2021 ◽  
Author(s):  
Hui Li ◽  
Shuaiwei Wang ◽  
Shuangshuang An ◽  
Biao Gao ◽  
Tieshan Teng ◽  
...  

Abstract Background Renal ischemia-reperfusion injury (IRI) is a major cause of acute kidney injury. Hydrogen sulfide (H2S) exerts a protective effect in renal IRI. The present study was carried out to investigate the effects of exogenous H2S on renal IRI by regulating autophagy in mice. Methods Mice were randomly assigned to control, IRI, and NaHS (28, 56 and 100 µmol/kg) groups. Renal IRI was induced by clamping the bilateral renal pedicles for with non-traumatic arterial clamp for 45 min and then reperfused for 24 h. Mice were administered intraperitoneally with NaHS 20 min prior to renal ischemia. Sham group mice underwent the same procedures without clamping. Serum and kidney tissues were harvested 24 h after reperfusion for functional, histological, oxidative stress, and autophagic determination. Results Compared with the control group, the concentrations of serum creatinine (Scr), blood urea nitrogen (BUN), and malondialdehyde (MDA), the protein levels of LC3II/I, Beclin-1, and P62, as well as the number of autophagosomes were significantly increased, but the activity of superoxide dismutase (SOD) was decreased after renal IRI. NaHS pretreatment dramatically attenuated renal IRI-induced renal dysfunction, histological changes, MDA concentration, and p62 expression in a dose-dependent manner. However, NaHS increased the SOD activity and the protein levels of LC3II/I and Beclin-1. Conclusions These results indicate that exogenous H2S protects the kidney from IRI through enhancement of autophagy and reduction of oxidative stress. Novel H2S donors could be developed in the treatment of renal IRI.


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