8-hydroxy-2--deoxyguanosine and Kidney-Diseases

Since co-administration of ezetimibe, a specific inhibitor of cholesterol absorption into the intestine, has been shown to augment lipid-lowering effects of statins, ezetimibe plus statins is a novel therapeutic strategy for the treatment of dyslipidemia in high-risk patients. Statins have been shown to ameliorate renal function and reduce proteinuria in patients with chronic kidney disease (CKD). However, effects of co-administration of ezetimibe with statins on renal damage and dysfunction in CKD patients remain unknown. In this study, we examined whether co-administration of ezetimibe with pitavastatin could augment renoprotective properties of pitavastatin in non-diabetic CKD patients with dyslipidemia. Total cholesterol, LDL-cholesterol and triglycerides levels were reduced more by co-administration of ezetimibe (10mg/day) with pitavastatin (2mg/day) (n=10) than by pitavastatin alone (n=10). In addition, ezetimibe plus pitavastatin treatment produced significant incremental reduction in proteinuria related to pitavastatin therapy alone. In univariate analyses, proteinuria was correlated with plasma levels of total cholesterol, LDL-cholesterol, triglycerides, HDL-cholesterol (inversely), asymmetric dimethylarginine, an endogenous nitric oxide synthase inhibitor, and urinary excretion levels of L-fatty acid binding protein (L-FABP), a marker of tubular injury and 8-hydroxydeoxyguanosine (8-OHdG), an oxidative stress marker. Multiple stepwise regression analysis revealed that LDL-cholesterol (p<0.001) and urinary excretion levels of L-FABP (p=0.001) and 8-OHdG (p<0.001) were independently related to proteinuria (R(2)=0.969). Our present study demonstrated for the first time that co-administration of ezetimibe enhanced proteinuria-lowering effects of pitavastatin in non-diabetic CKD patients partly via a cholesterol-independent manner. Ezetimibe may have pleiotropic actions that could contribute to renoprotective properties of this lipid-lowering agent.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Anticholesteremic Agents; Arginine; Azetidines; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Deoxyguanosine; Drug Therapy, Combination; Dyslipidemias; Ezetimibe; Fatty Acid-Binding Proteins; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Kidney Diseases; Male; Middle Aged; Proteinuria; Quinolines; Severity of Illness Index; Treatment Outcome; Triglycerides

Concurrent exposure to ionizing radiation (IR) and psychological stress (PS) may affect the development of adverse health consequences in scenarios such as space missions, radiotherapy and nuclear accidents. IR can induce DNA damage and cell apoptosis in the kidneys, thus potentially leading to renal fibrosis, which is the ultimate outcome of various chronic progressive nephropathies and the morphological manifestation of a continuous coordinated response after renal injury. However, little is known regarding the effects of concurrent IR exposure and PS on renal damage, particularly renal fibrosis. In this study, using a chronic restraint-induced PS (CRIPS) model, we exposed

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Apoptosis; Female; Fibrosis; Humans; Ions; Iron; Kidney; Kidney Diseases; Male; Mice; Mice, Inbred C57BL; Whole-Body Irradiation

Aging kidneys are characterized by an increased vulnerability to glomerulosclerosis and a measurable decline in renal function. Evidence suggests that renal and systemic klotho and sirtuin 1 (SIRT1) deficiencies worsen kidney damage induced by exogenous stresses. The aim of this study was to explore whether resveratrol would attenuate concanavalin A (Con A)-induced renal oxidative stress and advanced glomerulosclerosis in aged mice. Aged male C57BL/6 mice were treated orally with resveratrol (30 mg/kg) seven times (12 h intervals) prior to the administration of a single tail-vein injection of Con A (20 mg/kg). The plasma and urinary levels of kidney damage markers were evaluated. The kidney histopathology, renal parameters, and oxidative stress levels were measured. Furthermore, klotho was downregulated in mouse kidney mesangial cells that were pretreated with 25 µM resveratrol followed by 20 µg/mL Con A. The urinary albumin/creatinine ratio, blood urea nitrogen, kidney mesangial matrix expansion, tubulointerstitial fibrosis, and renal levels of α-smooth muscle actin, transforming growth factor beta, fibronectin, procollagen III propeptide, and collagen type I significantly increased in Con A-treated aged mice. Aged mice kidneys also showed markedly increased levels of 8-hydroxydeoxyguanosine (8-OH-dG) and reactive oxygen species (ROS), with reduced superoxide dismutase activity and levels of glutathione, klotho, and SIRT1 after Con A challenge. Furthermore, in kidney mesangial cells, klotho silencing abolished the effects of resveratrol on the Con A-mediated elevation of the indices of oxidative stress and the expression of glomerulosclerosis-related factors. These findings suggest that resveratrol protects against Con A-induced advanced glomerulosclerosis in aged mice, ameliorating renal oxidative stress via the SIRT1-mediated klotho expression.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aging; Animals; Cell Line; Concanavalin A; Fibronectins; Fibrosis; Glucuronidase; Kidney; Kidney Diseases; Klotho Proteins; Male; Mesangial Cells; Mice; Mice, Inbred C57BL; Oxidative Stress; Reactive Oxygen Species; Resveratrol; Signal Transduction; Sirtuin 1; Superoxide Dismutase; Up-Regulation

Preclinical studies have demonstrated that maternal inflammation or neonatal hyperoxia adversely affects kidney maturation. This study explored whether prenatal lipopolysaccharide (LPS) exposure can augment neonatal hyperoxia-induced kidney injury.. Pregnant Sprague-Dawley rats received intraperitoneal injections of LPS (0.5 mg/kg) in normal saline (NS) or NS on 20 and 21 days of gestation. The pups were reared in room air (RA) or 2 weeks of 85% O. The rats exposed to maternal LPS or neonatal hyperoxia exhibited significantly higher kidney injury score, lower glomerular number, higher toll-like receptor 4 (TLR4), myeloperoxidase (MPO), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) expressions, and higher MPO activity compared with the rats exposed to maternal NS and neonatal RA. The rats exposed to both maternal LPS and neonatal hyperoxia exhibited significantly lower glomerular number, higher kidney injury score, TLR4, MPO, and 8-OHdG expressions compared with the rats exposed to maternal LPS or neonatal hyperoxia.. Maternal inflammation exacerbates neonatal hyperoxia-induced kidney injury and the underlying mechanism may be related to activation of TLR4 and increased oxidative stress.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Animals, Newborn; Antibodies; Body Weight; Chorioamnionitis; Cytokines; Female; Hyperoxia; Inflammation; Kidney Diseases; Lipopolysaccharides; Maternal Exposure; Organ Size; Oxidative Stress; Oxygen; Peroxidase; Pregnancy; Pregnancy Complications; Prenatal Exposure Delayed Effects; Rats; Rats, Sprague-Dawley; Toll-Like Receptor 4

Astragalus membranaceus, a traditional Chinese medicine (TCM), has been widely used in the treatment of chronic kidney disease (CKD) in China. Astragaloside IV is one of the major compounds of Astragalus membranaceus. Recent research has shown that astragaloside IV demonstrates pharmacological effects, such as anti-inflammatory, anti-fibrotic and anti-oxidative stress activities. Our aim was to investigate the effects of astragaloside IV on indoxyl sulfate (IS)-induced kidney injury in vivo, and to study the underlying mechanism.. Forty C57BL/6 mice with ½ nephrectomy were divided into four groups: control group (n = 10), IS group (n = 10), IS plus 10 mg/kg of astragaloside IV group (n = 10) and IS plus 20 mg/kg of astragaloside IV group (n = 10). IS intraperitoneal injection and astragaloside IV treatment were administered continuously for 1 month. Next, the blood urea nitrogen (BUN) level, serum IS level, tubulointerstitial injury, renal oxidative stress and inflammatory injury were assessed.. The IS intraperitoneal injection mouse group showed increasing levels of serum IS, BUN, tubulointerstitial injury, renal oxidative stress and inflammatory injury. Astragaloside IV treatment couldn't reduce the serum IS level or renal nuclear factor-κB and interleukin-1β levels. However, 20 mg/kg astragaloside IV treatment reduced the BUN level and significantly attenuated IS-induced tubulointerstitial injury. Renal oxidative stress was decreased by the administration of astragaloside IV.. These results suggest that astragaloside IV prevents IS-induced tubulointerstitial injury by ameliorating oxidative stress and may be a promising agent for the treatment of uremia toxin-induced injury.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Antioxidants; Deoxyguanosine; Indican; Interleukin-1beta; Interleukin-6; Kidney; Kidney Diseases; Male; Malondialdehyde; Mice, Inbred C57BL; Oxidative Stress; Saponins; Superoxide Dismutase; Triterpenes

This study was carried out to determine the effect of zinc on oxidative DNA damage in rats with experimental acute and chronic kidney deficiency. Six groups of five Wistar-Albino rats each were assigned as controls (C), acute kidney deficiency (AKD), zinc-supplemented (+Zn), acute kidney deficiency, zinc-supplemented (AKD + Zn), chronic kidney deficiency (CKD) and zinc-supplemented chronic kidney deficiency (CKD + Zn). The levels of 8-Oxo-2'-deoxyguanosine (8-OHdG) were determined, being the lowest in the CKD group (p < 0.05), higher in the C group than those of rats with CKD but lower than that of all the other groups (p < 0.05). There were no significant differences between the controls and the CKD + Zn group, or between the AKD and the +Zn groups. Among all groups, the highest 8-OHdG level was found in the AKD + Zn group (p < 0.05). DNA damage was greater in acute renal failure than in rats with chronic renal failure. The DNA damage in the zinc group was significantly higher than in the controls.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Deoxyguanosine; Dietary Supplements; DNA Damage; Kidney Diseases; Male; Rats; Rats, Wistar; Zinc

Context Ginseng is a widely used herbal medicine in China but its mechanism of action remains unclear. Objective The objectives of this work were to study the protective effect of ginsenoside Rg1 on subacute murine renal damage induced by d-galactose and its mechanism. Materials and methods C57BL/6J mice were injected with 120 mg/kg/d (sc) d-galactose for 1 week, followed by a combined treatment of Rg1 20 mg/kg/d (ip) and 120 mg/kg/d d-galactose (sc) for 5 weeks. Mice were injected with the 0.9% saline 0.2 mL/d (sc) and 120 mg/kg/d d-galactose (sc) for 6 weeks in the control group and the d-galactose group, respectively. After 6 weeks, urea, creatinine, uric acid, cystatin (Cys-C), senescence-associated β-galactosidase (SA-β-gal) staining positive kidney cells, superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), malondialdehyde (MDA), glycation end products (AGEs) and 8-hydroxy-2 deoxyguanosine (8-OH-dG) were measured. Results Treatment with Rg1 ameliorated kidney function and aging state (urea from 17.19 ± 1.09 to 15.77 ± 1.22 mmol·L (-) (1), creatinine from 29.40 ± 5.72 to 22.60 ± 3.97 μmol·L (-) (1), uric acid from 86.80 ± 5.97 to 72.80 ± 10.61 μmol·L (-) (1), Cys-C from 0.23 ± 0.03 to 0.18 ± 0.05 mg·L (-) (1), ROD of SA-β-gal from 56.32 ± 10.48 to 26.78 ± 7.34, SOD from 150.22 ± 19.07 to 190.56 ± 15.83 U·(mg·prot) (-1), MDA from 9.28 ± 1.59 to 3.17 ± 0.82 nmol·(mg·prot) (-1), GSH-PX from 15.68 ± 2.11 to 20.32 ± 2.96 U·(mg·prot) (-1) as well as regulated glomerulus morphology (glomerulus diameter from 775.77 ± 18.41 to 695.04 ± 14.61 μm, renal capsule width from 39.56 ± 3.51 to 31.42 ± 2.70 μm, glomerulus basement membrane from 206.03 ± 16.22 to 157.27 ± 15.70 nm, podocyte slit from 55.21 ± 8.55 to 37.63 ± 6.65 nm). Conclusions Ginsenoside Rg1 can antagonise d-galactose subacute renal damage in mice and this may occur due to alleviating oxidative stress injury.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Antioxidants; Biomarkers; Cytoprotection; Deoxyguanosine; Disease Models, Animal; DNA Damage; Galactose; Ginsenosides; Glutathione Peroxidase; Glycation End Products, Advanced; Kidney; Kidney Diseases; Male; Malondialdehyde; Mice, Inbred C57BL; Oxidative Stress; Superoxide Dismutase

This study aimed to investigate the possible protective effect of paricalcitol on experimental amikacin-induced nephrotoxicity model in rats. Wistar albino rats (n = 32) were allocated into four equal groups of eight each, the control (Group C), paricalcitol (Group P), amikacin-induced nephrotoxicity (Group A), and paricalcitol-treated amikacin-induced nephrotoxicity (Group A + P) groups. Paricalcitol was given intra-peritoneally at a dose of 0.4 μg/kg/d for 5 consecutive days prior to induction of amikacin-induced nephrotoxicity. Intra-peritoneal amikacin (1.2 g/kg) was used to induce nephrotoxicity at day 4. Renal function parameters, oxidative stress biomarkers, oxidative DNA damage (8-hydroxy-2'-deoxyguanosine/deoxyguanosine ratio), kidney histology, and vascular endothelial growth factor (VEGF) immunoexpression were determined. Group A + P had lower mean fractional sodium excretion (p < 0.001) as well as higher creatinine clearance (p = 0.026) than the amikacin group (Group A). Renal tissue malondialdehyde levels (p = 0.035) and serum 8-hydroxy-2'-deoxyguanosine/deoxyguanosine ratio (8-OHdG/dG ratio) (p < 0.001) were significantly lower; superoxide dismutase (p = 0.024) and glutathione peroxidase (p = 0.007) activities of renal tissue were significantly higher in group A + P than in group A. The mean scores of tubular necrosis (p = 0.024), proteinaceous casts (p = 0.038), medullary congestion (p = 0.035), and VEGF immunoexpression (p = 0.018) were also lower in group A + P when compared with group A. This study demonstrates the protective effect of paricalcitol in the prevention of amikacin-induced nephrotoxicity in an experimental model. Furthermore, it is the first study to demonstrate that paricalcitol improves oxidative DNA damage in an experimental acute kidney injury model.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Amikacin; Animals; Anti-Bacterial Agents; Bone Density Conservation Agents; Deoxyguanosine; Disease Models, Animal; DNA Damage; Ergocalciferols; Kidney; Kidney Diseases; Kidney Function Tests; Malondialdehyde; Oxidative Stress; Rats; Rats, Wistar; Vascular Endothelial Growth Factor A

Our previous clinical indicated that urinary cyclophilin A was a good marker for diabetic nephropathy.. We used animal and cell models of diabetic nephropathy to examine the role of cyclophilin A in disease progression.. Significantly increased urinary cyclophilin A could be detected in db/db at the 8th week. Linagliptin (3mg/kg/day and 15mg/kg/day) could suppress urinary 8-hydroxy-2'-deoxyguanosine at the 8th and 16th week but only the high dose Linagliption could suppress cyclophilin A at the 8th week. Compared to 8-hydroxy-2'-deoxyguanosine, cyclophilin A was a stronger, earlier, and more sensitive marker. Immunohistochemical staining for cyclophilin A was also positive for db/db. In cell studies, oxidative stress and hyperglycemia could stimulate MES-13 and HK-2 cells to secrete cyclophilin A. Hyperglycemia stimulated HK-2 cells to secrete TGFβ1, which caused secretion of cyclophilin A. The secreted cyclophilin A further stimulated CD 147 to move outward from cytosol onto cell membrane in confocal microscopy, which was associated with the p38 MAPK pathway in the downstream.. Secreted cyclophilin A may play an important role in diabetic nephropathy in the mouse model and is associated with TGFβ1, CD 147, and the p38 MAPK pathway.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Cells, Cultured; Cyclophilin A; Deoxyguanosine; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Kidney Diseases; Linagliptin; Mice; Mice, Transgenic

Calcineurin inhibitor nephrotoxicity is major problem after organ transplantation. It is multifactorial, but oxidative stress may have an important role in this process. It has been shown that angiotensin II receptor blockers have renoprotective effects but their molecular mechanism is largely unknown. Antioxidative effect is an important role of the recently known anti-aging protein, klotho. This study aimed to evaluate effect of valsartan in alleviation of cyclosporine A nephrotoxicity via a probable increase in serum klotho levels or decreasing oxidative stress.. Thirty-two Sprague-Dawley rats were divided into 4 groups to receive 1 mL/kg/d of olive oil as control; 30 mg/kg/d of cyclosporine; 30 mg/kg/d of cyclosporine and 50 mg/kg/d of valsartan; and 50 mg/kg/d of valsartan. After the 6 weeks of administration period, serum levels of klotho and 8-hydroxydeoxyguanosine were measured using an enzyme-linked immunosorbent assay. Serum malondialdehyde level was measured spectrophotometrically.. The mean serum level of klotho was significantly lower in the cyclosporine group compared with control and valsartan groups. Klotho level in the valsartan group was significantly higher than those in the other groups. The cyclosporine group was detected to have significantly higher serum 8-hydroxydeoxyguanosine and malondialdehyde levels compared with the other study groups. The levels of klotho were negatively correlated with 8-hydroxydeoxyguanosine and malondialdehyde levels.. Administration of valsartan may lead to attenuation of the nephrotoxic side effect of cyclosporine via enhancing klotho and decreasing oxidative stress levels.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Angiotensin Receptor Antagonists; Animals; Calcineurin Inhibitors; Cyclosporine; Deoxyguanosine; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Glucuronidase; Kidney; Kidney Diseases; Klotho Proteins; Malondialdehyde; Oxidative Stress; Random Allocation; Rats; Rats, Sprague-Dawley; Spectrophotometry; Valsartan

The objective of this study was to assess the risk of genotoxicity of d-phenothrin by measuring the oxidative stress it causes in rat liver and kidney. The level of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG)/10(6) 2'-deoxyguanosine (dG) was measured by using high performance liquid chromatography (HPLC) with a diode array (DAD) and an electrochemical detector (ECD). Sixty male Wistar albino rats were randomly divided into five experimental groups and one control group of 10 rats/group. d-phenothrin was administered intraperitoneally (IP) to the five experimental groups at 25 mg/kg (Group I), 50 mg/kg (Group II), 66.7 mg/kg (Group III), 100 mg/kg (Group IV), and 200 mg/kg (Group V) for 14 consecutive days, and the control group received only the vehicle, dimethyl sulfoxide (DMSO). DNA from samples frozen in liquid nitrogen was isolated with a DNA isolation kit. Following digestion with nuclease P1 and alkaline phosphatase (ALP), hydrolyzed DNA was subjected to HPLC. The dG and 8-oxodG levels were analyzed with a DAD and ECD, respectively. In the experimental groups, the mean 8-oxodG/10(6) dG levels were 48.15 ± 7.43, 68.92 ± 20.66, 82.07 ± 14.15, 85.08 ± 28.50, and 89.14 ± 21.73 in livers and 39.06 ± 7.63, 59.69 ± 14.22, 61.13 ± 17.46, 65.13 ± 23.40, and 72.66 ± 19.04 in kidneys of Groups I, II, III, IV, and V, respectively. The mean 8-oxodG/10(6) dG levels in the control groups were 44.96 ± 12.66 for the liver and 39.07 ± 4.80 for the kidney. A statistically significant (p < 0.05), dose-dependent increase in oxidative DNA damage was observed in both organs of animals exposed to d-phenothrin when compared to controls. Furthermore, the liver showed a significantly higher level of oxidative DNA damage than the kidney (p < 0.01). In conclusion, d-phenothrin administered to rats intraperitoneally for 14 consecutive days generated free radical species in a dose-dependent manner and caused oxidative DNA damage in the liver and kidney.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Calibration; Chemical and Drug Induced Liver Injury; Chromatography, High Pressure Liquid; Deoxyguanosine; DNA Damage; Electrochemistry; Insecticides; Kidney Diseases; Male; Oxidative Stress; Pyrethrins; Rats; Rats, Wistar; Reproducibility of Results

Human and animal studies have demonstrated that neonatal hyperoxia increases oxidative stress and adversely affects glomerular and tubular maturity. This study was undertaken to determine how exposure to neonatal hyperoxia affected kidney morphology and fibrosis and to elucidate the relationship between connective tissue growth factor (CTGF) and collagen expression in rat kidneys.. Sprague-Dawley rat pups were exposed to either hyperoxia or ambient air. The control groups were maintained in ambient air for 1 week and 3 weeks. The hyperoxia groups were exposed to >95% O2 for 1 week and subsequently placed in an environment of 60% O2 for an additional 2 weeks. The animals were euthanized on Postnatal Day 7 or 21 and the kidneys underwent histological analyses and oxidative stress and total collagen measurements.. The rats reared in O2-enriched air exhibited significantly higher tubular injury scores (1.4 ± 0.5 vs. 0.7 ± 0.7 on Day 7; 1.4 ± 0.5 vs. 0.6 ± 0.5 on Day 21), a larger proportion of the cortex occupied by glomeruli (25.5 ± 4.1 vs. 21.3 ± 3.1% on Day 7; 20.1 ± 3.5 vs. 17.1 ± 1.7% on Day 21), larger glomerular sizes (84.7 ± 5.8 vs. 77.5 ± 6.1 μm on Day 7; 88.4 ± 2.9 vs. 84.9 ± 3.1 μm on Day 21), and higher total collagen content (54.1 ± 27.5 vs. 18.3 ± 6.3 μg/mg protein on Day 7; 397.4 ± 32.8 vs. 289.5 ± 80.0 μg/mg protein on Day 21) than did rats reared in ambient air. Immunohistochemical expressions of oxidative stress marker 8-hydroxy-2'-deoxyguanosine and CTGF immunoreactivities were significantly higher in the rats reared in O2-enriched air compared with the rats reared in ambient air on Postnatal Days 7 and 21.. Neonatal hyperoxia exposure contributes to kidney fibrosis, which is probably caused by activated CTGF expression.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Animals, Newborn; Collagen; Connective Tissue Growth Factor; Deoxyguanosine; Female; Fibrosis; Humans; Hyperoxia; Kidney; Kidney Diseases; Maternal Exposure; Oxidative Stress; Pregnancy; Prenatal Exposure Delayed Effects; Rats; Rats, Sprague-Dawley

Contrast-induced nephropathy (CIN) refers to acute renal damage that occurs after the use of contrast agents. This study investigated the renal protective effect of probucol in a rat model of contrast-induced nephropathy and the mechanism of its effect.. Twenty-eight Wistar rats were randomly divided into the control group, model group, N-acetylcysteine(NAC) group, and probucol group. We used a rat model of iopromide-induced CIN. One day prior to modeling, the rats received gavage. At 24 h after the modeling, blood biochemistry and urine protein were assessed. Malondialdehyde (MDA) and superoxide dismutase (SOD) were measured in renal tissue. Kidney sections were created for histopathological examination.. The model group of rats showed significantly elevated levels of blood creatinine, urea nitrogen, 24-h urine protein, histopathological scores, and parameters of oxidative stress (P<0.05). Both the NAC and probucol groups demonstrated significantly lower Scr, BUN, and urine protein levels compared to the model group (P<0.05), with no significant difference between these 2 groups. The NAC group and the probucol group had significantly lower MDA and higher SOD than the model group at 24 h after modeling (P<0.05). The 8-OHdG-positive tubule of the probucol group and NAC group were significantly lower than those of the model group (p=0.046, P=0.0008), with significant difference between these 2 groups (P=0.024).. Probucol can effectively reduce kidney damage caused by contrast agent. The underlying mechanism may be that probucol accelerates the recovery of renal function and renal pathology by reducing local renal oxidative stress.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Acetylcysteine; Animals; Antioxidants; Contrast Media; Creatinine; Deoxyguanosine; Disease Models, Animal; Immunohistochemistry; Kidney; Kidney Diseases; Male; Malondialdehyde; Nitrogen; Oxidative Stress; Probucol; Rats; Rats, Wistar; Superoxide Dismutase

To explore the protective effect of Angelica sinensis polysaccharides(ASP) on subacute renal damages induced by D-galactose in mice and its mechanism. Male C57BL/6J mice were randomly divided into 3 groups, with 10 mice in each group. The D-galactose model group was subcutaneously injected with D-galactose (120 mg x kg(-1)), qd x 42; the ASP + D-galactose model group was intraperitoneally injected with ASP since the 8th day of the replication of the D-galactose model, qd x 35; and the normal control group was subcutaneously injected with saline at the same dose and time. On the 2nd day of after the injection, the peripheral blood was collected to measure the content of BUN, Crea, UA, Cys-C; paraffin sections were made to observe the renal histomorphology by HE staining; senescence-associated β-g-alactosidase (SA-β-Gal) stain was used to observe the relative optical density (ROD) in renal tissues; transmission electron microscopy was assayed to observe the renal ultrastructure; the renal tissue homogenate was prepared to measure the content of SOD, GSH-PX, MDA; the content of AGEs and 8-OH-dG were measured by ELISA. According to the result, compared with the D-galactose model group, the ASP + D-galactose model group showed obviously decreases in the content of BUN, Crea, UA, Cysc, AGES, 8-OH-dG, the number of hardening renal corpuscle, renal capsular space and renal tubular lumen, ROD of SA-β-Gal staining positive kidney cells, mesangial cells, basement membrane thickness, podocyte secondary processes fusion and MDA and increases in the number of normal renal corpuscle, ribosome and rough endoplasmic reticulum in podocytes, the activity of SOD and GSH-PX. In Conclusion, A. sinensis polysaccharides can antagonize kidney subacute damages induced by D-galactose in mice. Its protective mechanism may be correlated with the inhibition of the oxidative stress injury.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Angelica sinensis; Animals; Deoxyguanosine; Drugs, Chinese Herbal; Galactose; Humans; Kidney; Kidney Diseases; Male; Mice; Mice, Inbred C57BL; Oxidative Stress; Polysaccharides; Protective Agents

Experiments determined whether the combination of endothelin A (ETA) receptor antagonist [ABT-627, atrasentan; (2R,3R,4S)-4-(1,3-benzodioxol-5-yl)-1-[2-(dibutylamino)-2-oxoethyl]-2-(4-methoxyphenyl)pyrrolidine-3-carboxylic acid] and a thiazide diuretic (chlorthalidone) would be more effective at lowering blood pressure and reducing renal injury in a rodent model of metabolic syndrome compared with either treatment alone. Male Dahl salt-sensitive rats were fed a high-fat (36% fat), high-salt (4% NaCl) diet for 4 weeks. Separate groups of rats were then treated with vehicle (control), ABT-627 (ABT; 5 mg/kg per day, in drinking water), chlorthalidone (CLTD; 5 mg/kg per day, in drinking water), or both ABT plus CLTD. Mean arterial pressure (MAP) was recorded continuously by telemetry. After 4 weeks, both ABT and CLTD severely attenuated the development of hypertension, whereas the combination further reduced MAP compared with ABT alone. All treatments prevented proteinuria. CLTD and ABT plus CLTD significantly reduced nephrin (a podocyte injury marker) and kidney injury molecule-1 (a tubulointerstitial injury marker) excretion. ABT, with or without CLTD, significantly reduced plasma 8-oxo-2'-deoxyguanosine, a measure of DNA oxidation, whereas CLTD alone had no effect. All treatments suppressed the number of ED1(+) cells (macrophages) in the kidney. Plasma tumor necrosis factor receptors 1 and 2 were reduced only in the combined ABT and CLTD group. These results suggest that ABT and CLTD have antihypertensive and renal-protective effects in a model of metabolic syndrome that are maximally effective when both drugs are administered together. The findings support the hypothesis that combined ETA antagonist and diuretic treatment may provide therapeutic benefit for individuals with metabolic syndrome consuming a Western diet.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Antihypertensive Agents; Arterial Pressure; Atrasentan; Cell Adhesion Molecules; Chlorthalidone; Deoxyguanosine; Disease Models, Animal; Diuretics; Drug Combinations; Endothelin A Receptor Antagonists; Endothelins; Hypertension; Inflammation; Kidney Diseases; Male; Membrane Proteins; Metabolic Syndrome; Oxidative Stress; Proteinuria; Pyrrolidines; Rats; Rats, Inbred Dahl; Rats, Sprague-Dawley; Receptor, Endothelin A; Sodium Chloride, Dietary

Arsenic trioxide (As(2)O(3)) is an environmental toxicant and a potent antineoplastic agent. Exposure to arsenic causes renal cancer. Resveratrol is a well-known polyphenolic compound that is reported to reduce As(2)O(3)-induced cardiotoxicity. The present study aimed to investigate the effect of resveratrol on As(2)O(3)-induced nephrotoxicity and arsenic metabolism. Chinese Dragon-Li cats were injected with 1 mg/kg As(2)O(3) on alternate days; resveratrol (3 mg/kg) was administered via the forearm vein 1 h before the As(2)O(3) treatment. On the sixth day, the cats were killed to determine the histological renal damage, renal function, the accumulation of arsenic, and antioxidant activities in the kidney. Urine samples were taken for arsenic speciation. In the resveratrol + As(2)O(3)-treated group, activities of glutathione peroxidase, catalase, and superoxide dismutase, the ratio of reduced glutathione to oxidized glutathione, the total arsenic concentrations, and the percentage of methylated arsenic in urine were significantly increased. The concentrations of renal malondialdehyde, reactive oxygen species, 8-hydroxydeoxyguanosine, serum creatinine, blood urea nitrogen, and renal arsenic accumulation were significantly decreased and reduced renal morphologic injury was observed compared with the As(2)O(3)-treated group. These results demonstrate that resveratrol could significantly scavenge reactive oxygen species, inhibit As(2)O(3)-induced oxidative damage, and significantly attenuate the accumulation of arsenic in renal tissues by facilitating As(2)O(3) metabolism. These data suggest that use of resveratrol as postremission therapy for acute promyelocytic leukemia as well as adjunctive therapy in patients with exposure to arsenic may decrease arsenic nephrotoxicity.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Antioxidants; Arsenic Trioxide; Arsenicals; Blood Urea Nitrogen; Catalase; Cats; Creatinine; Cytoprotection; Deoxyguanosine; Glutathione; Glutathione Peroxidase; Injections, Intravenous; Kidney; Kidney Diseases; Malondialdehyde; Oxidative Stress; Oxides; Resveratrol; Stilbenes; Superoxide Dismutase

Bromate (BrO3(-)), a by-product of ozonation of drinking water, induces nephrotoxicity in male rats at much lower doses than in female rats. This difference appears to be related to the development of α-2u-globulin nephropathy in males. To determine sex-dependent changes in mRNA and protein expression in the renal cortex attributable to α-2u-globulin nephropathy, we performed microarray and immunohistochemical analyses in proximal renal tubules of male and female F344 rats treated with KBrO3 for 28 days. Particular attention was paid to molecular biomarkers of renal tubular injury. Microarray analysis of male and female rats treated with BrO3(-) at low doses (125 mg/L KBrO3) displayed marked sex-dependent changes in renal gene expression. The greatest differences were seen in genes encoding for cellular differentiation, apoptosis, ion transport, and cell proliferation. Differences by sex were especially prominent for the cell cycle checkpoint gene p21, the renal injury protein Kim-1, and the kidney injury and cancer biomarker protein osteopontin. Dose-related nephrotoxicity, assessed by hematoxylin and eosin staining, was greater in males compared to female rats, as was cellular proliferation, assessed by bromodeoxyuridine staining. The fraction of proximal renal cells with elevated 8-oxodeoxyguanosine (8-OH-dG) was only increased at the high dose and did not differ by sex. Dose-dependent increases in the expression of osteopontin were detected immunohistochemically only in male rats and were localized in proximal tubule cells. Similarly, BrO3(-) treatment increased clusterin and Kim-1 staining in the proximal tubules; however, staining for these proteins did not differ appreciably between males and females. These data demonstrate both qualitative and quantitative differences in the response of male versus female kidneys to BrO3(-)-treatment. These sex-dependent effects likely contribute to renal carcinogenesis of BrO3(-) in the male rat.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Bromates; Cell Adhesion Molecules; Cell Proliferation; Clusterin; Deoxyguanosine; Female; Gene Expression; Immunohistochemistry; Kidney Cortex; Kidney Diseases; Kidney Tubules; Male; Microarray Analysis; Oncogene Protein p21(ras); Osteopontin; Polymerase Chain Reaction; Protein Biosynthesis; Rats; Rats, Inbred F344; RNA, Messenger

Cyclosporine A (CsA)-associated oxidative stress has been proposed as an important mechanism of renal injury. This study was designed to examine whether N-acetylcysteine (NAC), a well-known antioxidant, affects Klotho, antiaging gene, expression and its signaling pathway in an experimental model of chronic CsA nephropathy.. Mice maintained on a low-sodium diet were given vehicle (olive oil, 1 mL/kg/day), CsA (30 mg/kg/day), NAC (150 mg/kg/day), or a combination of CsA and NAC for 4 weeks. The effect of NAC on CsA-induced renal injury was evaluated with basic parameters, histopathology, and markers of oxidative stress [8-hydroxy-2'-deoxyguanosine (8-OHdG) excretion and manganese superoxide dismutase (MnSOD) expression]. The influence of NAC on Klotho and its signal pathway (p-AKT and p-FoxO1) in CsA-treated mouse kidney was evaluated with immunohistochemistry and/or immunoblot.. Concomitant administration of CsA and NAC significantly improved renal function and attenuated tubulointerstitial fibrosis, and these changes were accompanied by decreased urinary 8-OHdG level and increased MnSOD expression. NAC treatment preserved Klotho gene expression compared with CsA treatment alone (P < 0.05), and this correlated with urinary 8-OHdG excretion (r = -0.934) and MnSOD expression (r = 0.873, P < 0.001 for both). Concomitant treatment of CsA and NAC translocated FoxO1 from the cytoplasm to the nucleus, implicating dephosphorylation of FoxO1 by NAC in p-AKT/p-FoxO1 pathway.. NAC treatment preserves Klotho expression and modifies p-AKT/p-FoxO1 pathway in chronic CsA nephropathy.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Acetylcysteine; Animals; Antioxidants; Apoptosis; Chronic Disease; Cyclosporine; Deoxyguanosine; Disease Models, Animal; Forkhead Box Protein O1; Forkhead Transcription Factors; Gene Expression; Glucuronidase; Immunosuppressive Agents; Kidney Diseases; Klotho Proteins; Male; Mice; Mice, Inbred ICR; Oxidative Stress; Proto-Oncogene Proteins c-akt; Signal Transduction; Superoxide Dismutase

Oxidative stress (OS) is directly involved in the formation of atheroma plaque and has been shown to be present since the early stages of Chronic Kidney Disease (CKD); however, the net role that dialytica techniques may play in OS process is yet to be determined. We studied three groups: hemodialysis (HD, n = 30), peritoneal dialysis (PD, n = 31), predialysis (pre-D, n = 32), and one control group (C, n = 67). Using highresolution liquid chromatography columns (HPLC), the superoxide dismutase (SOD), glutathione oxidized/reduced ratio (GSSG/GSH), and nuclear, as well as mitochondrial 8-oxo-dG (8-oxo-dG mit) were measured in lymphocytes. Protein carbonyls and F2-isoprostanes were measured in plasma. The antioxidant enzyme activity was evaluated by a spectrophotometric assay of catalase, glutathione peroxidase (GPX), glutathione reductase (GSR), and superoxide dismutase (SOD). Compared to the control group, all groups had significantly higher levels of products derived from molecular oxidation with a significant decrease in antioxidant enzymes. Patients in the pre-D group showed higher values for most of the oxidized molecules. The PD group showed a better oxidative balance, with no significant differences in levels of mitochondrial 8-oxo-dG when compared to the control group. We speculated that the better control of OS observed in patients receiving PD might be explained by the fact that this technique is more biocompatible, and this might help reduce the risk of cardiovascular events.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Aged; Biomarkers; Case-Control Studies; Catalase; Chi-Square Distribution; Chromatography, High Pressure Liquid; Cross-Sectional Studies; Deoxyguanosine; DNA Damage; F2-Isoprostanes; Female; Glutathione; Glutathione Peroxidase; Glutathione Reductase; Humans; Kidney Diseases; Linear Models; Lipid Peroxidation; Male; Middle Aged; Multivariate Analysis; Oxidative Stress; Peritoneal Dialysis; Protein Carbonylation; Renal Dialysis; Superoxide Dismutase; Treatment Outcome; Up-Regulation

Iron metabolism is an important factor of anemia in chronic kidney disease (CKD). Hepcidin is a regulator of iron homeostasis and has a major role in the anemia of chronic disease (ACD). Oxidative stress (OS) is also associated with iron metabolism. However, the clinical utility of hepcidin, especially its association with OS, in CKD patients not receiving dialysis is still unclear.. We recruited 117 patients (62 ± 15 years, 85 males, and median estimated glomerular filtration rate (eGFR) 22 ml/min/1.73 m2) with CKD not receiving dialysis. Serum 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker of DNA oxidative injury, and serum hepcidin-25 were measured by ELISA and by liquid chromatography tandem mass spectrometry, respectively.. Hepcidin-25 was associated positively with ferritin, high-sensitive C-reactive protein (hsCRP) and 8-OHdG, and negatively with eGFR and hemoglobin. Sex, oral iron, hemoglobin, transferrin saturation (TSAT), ferritin, and hsCRP were independently associated with hepcidin-25 in a multiple regression model. In contrast, neither eGFR nor 8-OHdG independently affected hepcidin- 25.. The close association between hepcidin and serum ferritin, oral iron and hsCRP indicates that it plays a key role in the pathogenesis of anemia in patients with CKD not receiving dialysis. In contrast, effects of eGFR and OS were not apparent.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Aged; Antimicrobial Cationic Peptides; C-Reactive Protein; Chronic Disease; Deoxyguanosine; Erythropoietin; Female; Hepcidins; Humans; Kidney Diseases; Male; Middle Aged; Oxidative Stress; Renal Dialysis

The study was performed to investigate the influence of cyclosporine A (CsA)-induced renal injury on autophagy in an experimental model of chronic CsA nephropathy.. Three dosages of CsA (7.5, 15, and 30 mg/kg/day) were administered to mice for 4 weeks. The formation of autophagosomes was measured with microtubule-associated protein 1 light chain 3 phospholipid-conjugated form (LC3-II) and beclin-1, and the ability of autophagic clearance was examined with sequestosome-1 (p62). Autophagic vacuoles were visualized and counted using electron microscopy. Double immunolabeling of LC3-II and active caspase-3 was performed to evaluate the association between autophagy and apoptosis. Oxidative stress was evaluated by measuring urinary 8-hydroxy-2'-deoxyguanosine excretion, demonstrating oxidative DNA damage. Antioxidative drugs, pravastatin and N-acetylcysteine, were used to evaluate the role of CsA-induced oxidative stress on autophagy.. CsA treatment increased the expressions of LC3-II and beclin-1 in the kidney in a dose-dependent manner. The number of p62-positive cells was also significantly increased in a CsA dose-dependent manner. Electron microscopy revealed excessive autophagic vacuoles in the CsA group compared with the vehicle group. Expression of active caspase-3 was increased in a CsA dose-dependent manner and was colocalized with LC3-II in the injured area of CsA-treated kidneys. Concurrent pravastatin or N-acetylcysteine treatment reduced urinary excretion of 8-hydroxy-2'-deoxyguanosine and subsequently decreased LC3-II expression and the number of p62-positive cells compared with the CsA group.. Chronic CsA nephropathy is a state of excessive autophagic vacuoles and decreased autophagic clearance. Oxidative stress may play an importation role in the induction of autophagy.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Acetylcysteine; Animals; Antioxidants; Apoptosis; Autophagy; Caspase 3; Cyclosporine; Deoxyguanosine; Dose-Response Relationship, Drug; Ether-A-Go-Go Potassium Channels; Kidney Diseases; Male; Mice; Microscopy, Electron; Microtubule-Associated Proteins; Oxidative Stress; Phagosomes; Pravastatin; Time Factors

The Klotho gene plays a role in suppressing ageing-related disorders. It is suggested that activation of renin-angiotensin system (RAS) or oxidative stress suppresses Klotho in the kidney. This study evaluated the association between Klotho expression and RAS in cyclosporine (CsA)-induced renal injury.. Chronic CsA nephropathy was induced by administering CsA (30 mg/kg) to mice on a low-salt diet (LSD) for 4 weeks. A normal-salt diet (NSD) was used as the control. Reverse transcription-polymerase chain reaction, western blot and immunohistochemistry were performed for Klotho and intrarenal RAS activity was measured using immunohistochemistry for angiotensinogen and renin. Oxidative stress was measured with urinary excretion of 8-hydroxy-2'-deoxyguanosine (8-OHdG).. CsA treatment decreased Klotho mRNA and protein in mouse kidney in a dose-dependent and time-dependent manner, but a concurrent treatment with losartan, an angiotensin II type 1 (AT1) receptor blocker, reversed the decrease in Klotho expression with histological improvement. This finding was more marked in the LSD than the NSD. Klotho expression was correlated with angiotensinogen and renin expression, tubulointerstitial fibrosis score and urinary 8-OHdG excretion.. Angiotensin II may play a pivotal role in regulating Klotho expression in CsA-induced renal injury. AT1 receptor blocker may inhibit the ageing process by decreasing oxidative stress caused by CsA.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aging; Angiotensin II; Animals; Blotting, Western; Chronic Disease; Cyclosporine; Deoxyguanosine; Disease Models, Animal; Glucuronidase; Immunoenzyme Techniques; Immunosuppressive Agents; Kidney Diseases; Klotho Proteins; Male; Mice; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Up-Regulation; Vasoconstrictor Agents

Salt intake not only elevates the levels of blood pressure, glomerular capillary pressure and proteinuria, but also increases oxidative stress within the renal cortex in animal models. We examined the effect of salt intake on the rate of renal function decline, urinary protein and oxidative stress in patients with chronic kidney disease (CKD).. Clinical data including systolic blood pressure (SBP)and diastolic blood pressure (DBP), serum creatinine, uric acid, total cholesterol, triglyceride, urinary protein, salt intake, protein intake of non-diabetic CKD 53 patients were observed for one year. At the end of the observation period, we measured 8-hydroxydeoxy guanosine (8-OHdG) in spot urine. We calculated the slope of reciprocal serum creatinine as the rate of renal function decline (delta1/Cr). We then investigated the relationship between those clinical factors and delta1/Cr, and urinary 8-OHdG, and also selected clinical factors that significantly influence delta1/Cr and urinary 8-OHdG by stepwise multiple regression analysis. In addition, we investigated the gender difference in urinary 8-OHdG.. Annual mean SBP and DBP of all patients were 121.5 +/- 9.3 mmHg and 72.5+/- 6.2 mmHg, respectively. delta1/Cr was negatively correlated with salt intake, urinary protein and urinary protein was a significant predictor of delta1/Cr in a multiple regression analysis. Salt intake was positively correlated with protein intake and urinary protein. Urinary 8-OHdG of all patients was positively correlated with urinary protein and it was a significant predictor. Urinary 8-OHdG of male patients was positively correlated with salt intake and was a significant predictor; in female patients, it was positively correlated with urinary protein and total cholesterol and these two factors were significant predictors.. Salt intake increases urinary protein and promotes the progression of renal failure in CKD patients.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aged; Biomarkers; Chronic Disease; Deoxyguanosine; Disease Progression; Humans; Kidney Diseases; Male; Middle Aged; Oxidative Stress; Proteinuria; Regression Analysis; Renal Insufficiency; Sodium Chloride, Dietary

Suppression of the renin-angiotensin system has proven efficacy for mitigation and treatment of radiation nephropathy, and it has been hypothesized that this efficacy is due to suppression of radiation-induced chronic oxidative stress. It is known that radiation exposure leads to acute oxidative stress, but direct evidence for radiation-induced chronic renal oxidative stress is sparse. We looked for evidence of oxidative stress after total-body irradiation in a rat model, focusing on the period before there is physiologically significant renal damage. No statistically significant increase in urinary 8-isoprostane (a marker of lipid peroxidation) or carbonylated proteins (a marker of protein oxidation) was found over the first 42 days after irradiation, while a small but statistically significant increase in urinary 8-hydroxydeoxy-guanosine (a marker of DNA oxidation) was detected at 35-55 days. When we examined renal tissue from these animals, we found no significant increase in either DNA or protein oxidation products over the first 89 days after irradiation. Using five different standard methods for detecting oxidative stress in vivo, we found no definitive evidence for radiation-induced renal chronic oxidative stress. If chronic oxidative stress is part of the pathogenesis of radiation nephropathy, it does not leave widespread or easily detectable evidence behind.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Blood Urea Nitrogen; Bone Marrow Transplantation; Deoxyguanosine; Dinoprost; Electrophoresis, Polyacrylamide Gel; Immunohistochemistry; Kidney Diseases; Models, Animal; Oxidative Stress; Rats; Whole-Body Irradiation

To investigate the possible protective effect and mechanism of ginsenoside Rb1 against oxidative damage and renal interstitial fibrosis on rats with unilateral ureteral obstruction (UUO).. In total, 80 male rats were randomly divided into 4 groups, 20 in each group: the sham operated group (SOR), UUO group, UUO with ginsenoside Rb1 treatment group (treated with intraperitoneal injection of 50 mg/ kg daily) and UUO with Losartan treatment group (as the positive control, treated with 20 mg/kg by gastrogavage per day). The rats were randomly sacrificed on day 3, 7 and 14 after surgery, respectively. The histopathologic changes of renal interstitial tissues were observed with Masson staining. The mRNA of transforming growth factor beta 1 (TGF-beta 1), collagen I and fibronectin were reversed transcribed and quantified by Real-time PCR. Enzyme-linked immunosorbent assay was used to quantitatively detect TGF-beta 1 and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels. P47phox protein expression was assessed by immunohistochemistry and Western blot analysis.. In the UUO model, the obstructed kidney showed typical features of progressive renal tubulointerstitial fibrosis, and the levels of TGF-beta1, collagen I and fibronectin increased (P<0.05). As compared with the UUO group, ginsennoside Rb1 significantly inhibited the interstitial fibrosis including tubular injury and collagen deposition, and decreased the levels of TGF-beta1 (P<0.05). Ginsenoside Rb1 also inhibited the heme oxygenase (HO-1) and 8-OHdG, two markers of oxidative stress (P<0.05). Moreover, ginsenoside Rb1 suppressed the expression of p47phox, a subunit of nicotinamide adeninedinucleotide phosphate (NADPH) oxidase (P<0.05).. Ginsenoside Rb1 can obviously inhibit renal interstitial fibrosis in rats with UUO, its mechanism possibly via against the oxidative damage and suppressing TGF-beta1 expression.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Deoxyguanosine; Drug Evaluation, Preclinical; Fibrosis; Gene Expression Regulation; Ginsenosides; Heme Oxygenase (Decyclizing); Kidney; Kidney Diseases; Male; Models, Biological; NADPH Oxidases; Oxidative Stress; Rats; Rats, Sprague-Dawley; Saponins; Transforming Growth Factor beta1; Ureteral Obstruction

Renal cell carcinoma (RCC) is more frequently observed in patients on dialysis than in patients with normal renal function. However, the mechanism underlying carcinogenesis in RCC patients on dialysis is still unclear. We hypothesized that oxidative stress affects patients on dialysis and generates new neoplasms, and therefore analysed the correlation between the influences of various markers of oxidative stress and carcinogenesis in those patients. We evaluated the immunohistochemical expression of oxidative stress markers, such as iNOS, 8-OHdG, and COX-2 in 42 cases on dialysis and 51 cases with normal renal function as a control. The methylation status of p16INK4a, p14ARF, VHL, and RASSF1A was analysed together with clinicopathological factors. Histologically, the papillary type was observed more frequently in dialysis RCC than in sporadic RCC. Immunohistochemically, overexpression of iNOS (p < 0.0001) and COX-2 (p = 0.0002) was more frequently observed in dialysis RCC. Furthermore, the 8-OHdG labelling index was significantly higher in dialysis RCC than in sporadic RCC. Hypermethylation of p16INK4a was more frequently found in dialysis RCC (p < 0.05). However, no significant correlations between oxidative stress markers and DNA hypermethylation status were observed. The overexpression of iNOS, COX-2, and 8-OHdG in dialysis RCC suggests that patients on dialysis are affected by oxidative stress and that this effect plays an important role in the genesis of dialysis RCC.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Aged; Biomarkers; Carcinoma, Renal Cell; CpG Islands; Cyclooxygenase 2; Deoxyguanosine; DNA Methylation; Female; Genes, p16; Humans; Immunohistochemistry; Kidney Diseases; Kidney Neoplasms; Male; Middle Aged; Neoplasm Proteins; Nitric Oxide Synthase Type II; Oxidative Stress; Polymerase Chain Reaction; Promoter Regions, Genetic; Renal Dialysis; Tumor Suppressor Protein p14ARF; Tumor Suppressor Proteins; Von Hippel-Lindau Tumor Suppressor Protein

TGF-beta1, which is one of the profibrogenic cytokines, is considered essential for both the tubulointerstitial fibrosis found in chronic kidney diseases and the repair of tissue damage in acute renal injury. Iron plays an important part in inflammatory damage since it supplies cytotoxic hydroxyl radicals. The aim of the present study was to examine the direct effects of iron on TGF-beta1 production and the expression of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker of oxidative stress, by human renal proximal tubular epithelial cells (RPTEC).. Using human RPTEC, TGF-beta1 expression was studied by immunohistochemical staining, ELISA and RNase protection assays. 8-OHdG expression was evaluated by immunohistochemical staining.. Ferric iron suppressed both TGF-beta1 secretion and mRNA expression, and enhanced 8-OHdG expression in RPTEC in a dose-dependent manner. Desferrioxamine, an iron chelator, eliminated the suppressive effect of ferric citrate on TGF-beta1 production.. The results suggest that iron may delay the repair of kidney injury during the acute inflammatory phase via a reduction in TGF-beta1 production by RPTEC. Iron chelation may therefore be a useful strategy in the treatment of inflammatory kidney diseases.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Acute Disease; Cell Culture Techniques; Deoxyguanosine; Enzyme-Linked Immunosorbent Assay; Epithelial Cells; Fibrosis; Humans; Hydroxyl Radical; Immunohistochemistry; Inflammation; Iron; Kidney; Kidney Diseases; Kidney Tubules, Proximal; Oxidants; Oxidative Stress; RNA, Messenger; Transforming Growth Factor beta; Transforming Growth Factor beta1

Rice has been one of the most important grains. While polished white rice is favored, colored strains of rice, red, or black, have been maintained for religious purposes in Japan. We studied whether feeding of unpolished colored rice instead of white rice ameliorates oxidative renal tubular damage in rats induced by ferric nitrilotriacetate. Whereas renal lipid peroxidation was exacerbated in white rice-fed group in comparison with standard chow group, this exacerbation was not observed in red or black rice-fed groups. These changes were dependent on the proportion of colored rice to standard chow in the diet. Cyanidin 3-O-beta-D-glucoside was detectable neither in the serum nor kidney after one week of colored rice diet, but serum protocatechuic acid was significantly increased after black rice diet. There was a generalized decrease in the renal glutathione peroxidase activity in rice diet groups. Renal enzymatic activities of superoxide dismutase, glutathione S-transferase and NAD(P)H quinone reductase were not associated with the levels of lipid peroxidation. However, renal catalase activity was significantly increased in black rice-fed groups. These may partly explain the antioxidative effect. Furthermore, colored strains of rice are rich in proteins. Thus, our data warrants further investigation of the antioxidative effect of colored rice.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Anthocyanins; Body Weight; Carcinogens; Catalase; Deoxyguanosine; Diet; Ferric Compounds; Glucosides; Glutathione Peroxidase; Glutathione Transferase; Hydrogen Peroxide; Hydroxybenzoates; Immunoenzyme Techniques; Iron; Kidney Diseases; Kidney Tubules, Proximal; Lipid Peroxidation; Male; Nitrilotriacetic Acid; Oryza; Phytotherapy; Rats; Rats, Wistar; Superoxide Dismutase; Thiobarbituric Acid Reactive Substances

Kidney irradiation clearly leads to a progressive reduction in function associated with concomitant glomerulosclerosis and/or tubulointerstitial fibrosis. However, the particular cell types, mediators and/or mechanisms involved in the development and progression of radiation nephropathy remain ill defined. Angiotensin II (Ang II) plays a major pathogenic role; administration of Ang II blockers markedly abrogates the severity of radiation nephropathy in experimental models. Both ionizing radiation and Ang II signal via generation of reactive oxygen species (ROS). Thus, we hypothesized that localized kidney irradiation might lead to a chronic oxidative stress. In view of the difficulty in measuring ROS in vivo we adopted an indirect immunohistochemical approach in which we used a monoclonal antibody specific for 8-hydroxy-2'-deoxyguanosine (8-OHdG), one of the most commonly used markers of DNA oxidation. The right kidney of 7-8 week-old male Sprague-Dawley rats was removed. Five to 6 weeks later the remaining hypertrophied kidney was irradiated with single doses of 0-20.0 Gy X-rays. Groups of rats, three per dose, were killed at 4, 8, 16 and 24 weeks post-irradiation, their kidneys fixed, and sections stained with the 8-OHdG-specific antibody N45.1. For quantitation of glomerular DNA oxidation with the N45.1 antibody stained sections, 50 glomeruli/animal were counted. The presence of any intensely stained nuclei within the glomerular tuft was scored as positive. Quantitation of tubular DNA oxidation employed a 10 x 10 point ocular grid. Sections were examined at 400 magnification; 250 tubular profiles were counted. All tubules with any nuclear staining were scored as positive.Sham-irradiated kidneys showed little evidence of DNA oxidation over the experimental period. In contrast, localized kidney irradiation led to a marked, dose-independent increase in glomerular and tubular cell nuclear DNA oxidation. This increase was evident at the first time point studied, i.e. 4 weeks after irradiation, and persisted for up to 24 weeks postirradiation. DNA oxidation in the irradiated kidney was only seen in apparently viable glomerular and tubular cells. Thus, while from 16 to 24 weeks post-irradiation structural alterations had progressed to glomerular sclerosis and tubular atrophy, positive staining for 8-OHdG was not observed in severely atrophic tubules. Similarly, fewer positive staining cells were noted in glomeruli undergoing sclerosis, while none were seen in

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Deoxyguanosine; Fibrosis; Kidney; Kidney Diseases; Kidney Glomerulus; Kidney Tubules; Male; Oxidative Stress; Radiation Injuries, Experimental; Rats; Rats, Sprague-Dawley; X-Rays

It has been reported that advanced glycosylation end products (AGEs) play an important role in the development of diabetic complications. To evaluate the relationship between serum AGEs and diabetic nephropathy, we measured serum AGE levels in diabetic patients with normoalbuminuria (N), microalbuminuria (M), overt proteinuria (O), and hemodialysis (HD), non diabetic patients with nephropathy, and age-matched control subjects using the enzyme-linked immunosorbent assay (ELISA). Urine AGE levels were also measured in these subjects except group HD. Serum AGE levels in diabetic patients were not significantly higher than those in the normal subjects. When we compared serum AGE levels among various stages of diabetic nephropathy, groups O and HD had significantly higher serum AGE levels than the other groups. Serum AGE levels in group HD were almost 6-fold higher than those in groups N and M. In contrast, there were no significant differences in urinary AGE levels among any diabetic groups. As for the variables that determine serum AGE levels in diabetic patients, there was no significant correlation between serum AGEs and fasting blood glucose, hemoglobin A1c (HbA1c), or duration of diabetes. In contrast, serum AGEs showed a strong correlation with serum creatinine and an inverse correlation with creatinine clearance. To evaluate the relationship between serum AGEs and oxidative stress in diabetic nephropathy, urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and serum malondialdehyde (MDA), which are biological markers of total oxidative stress in vivo, were also examined. Both urinary 8-OHdG and serum MDA levels were significantly higher in diabetic patients with proteinuria versus those without proteinuria. However, there was no significant correlation between serum AGEs and urinary 8-OHdG or serum MDA levels in diabetic patients. These results suggest that the accumulation of serum AGEs in diabetic nephropathy may be mainly due to decreased removal in the kidney rather than increased production by high glucose levels or oxidative stress.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Albuminuria; Deoxyguanosine; Diabetes Mellitus; Diabetic Nephropathies; Female; Glycation End Products, Advanced; Humans; Kidney Diseases; Kidney Failure, Chronic; Male; Malondialdehyde; Middle Aged; Oxidative Stress; Proteinuria; Renal Dialysis

An increased incidence of cancer in patients suffering from acute intermittent porphyria (AIP) is thought to be related to delta-aminolevulinic acid (ALA) accumulation. Chronic treatment with ALA augmented 8-oxo-7,8-dihydro-2'-deoxyguanosine levels, decreased microsomal and mitochondrial membrane fluidity and increased lipid peroxidation in blood serum. Co-treatment with melatonin completely counteracted the effects of ALA. Melatonin effectively protects DNA and microsomal and mitochondrial membranes in rat kidney from oxidative damage due to ALA. Because of its low toxicity and anticarcinogenic properties, melatonin could be tested as an agent to reduce oxidative damage in patients with AIP.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aminolevulinic Acid; Animals; Antioxidants; Carcinogens; Deoxyguanosine; DNA; DNA Damage; Intracellular Membranes; Kidney; Kidney Diseases; Lipid Peroxidation; Male; Malondialdehyde; Melatonin; Membrane Fluidity; Microsomes; Mitochondria; Oxidative Stress; Rats; Rats, Sprague-Dawley

Na-nitrilotriacetic acid (Na3NTA) and Fe-nitrilotriacetic acid (FeNTA) have both been described to cause tumors in the urinary tract of rodents. However, these effects were observed using different modes of administration at extremely different dose levels and explained by different mechanisms. Whereas FeNTA causes an iron overload of cells and is genotoxic in various assays, Na3NTA is predominantly bound to zinc in vivo and thereby causes cytotoxic effects in the urinary tract. In contrast to FeNTA, Na3NTA requires high dose levels to produce tumors. The aim of this study was to compare the effects of Na3NTA and FeNTA on cellular proliferation, histopathology, lipid peroxidation, and 8-OH-2'-deoxyguanosine levels in the kidneys as well as on the urinary excretion of Ca, Fe, and Zn. For evaluation of DNA synthesis both compounds were administered for 1 or 4 weeks to 14-week-old male Wistar rats at a tumor causing dose, Na3NTA via the diet at 150 ppm and 20,000 ppm (approximately 9 and approximately 1000 mg/kg/day) and FeNTA i.p. at 25 mg/kg/day. An osmotic minipump, containing 20 mg/ml BrdU, was implanted subcutaneously 7 days before necropsy. Na3NTA showed nearly no effect on DNA replication after 1 week but a strong reaction after 4 weeks. The increase was 10- to 18-fold in different renal compartments. The enhancement of proliferation in the proximal tubules was nearly twice that in the distal tubules. In contrast, FeNTA caused DNA replication during the first week, and this was restricted to the proximal tubules. After 4 weeks there was an 18-fold increase in the outer stripe and no effect in the inner stripe of the outer medulla. The data presented give evidence to the assumption that both substances increase cell proliferation as a compensatory mechanism, causing different pattern of tubular proliferation in terms of time course and affected cell types. Both Na3NTA at 20,000 ppm and FeNTA led to increased lipid peroxidation, whereas increased levels of 8-OH-2'-deoxyguanosine were observed only after treatment with FeNTA. Urinary excretion of Zn was increased 30-fold after administration of 20,000 ppm Na3NTA but only 2-fold after administration of FeNTA. Urinary excretion of Ca and Fe remained unchanged after treatment with either Na3NTA and FeNTA. These results show that the Na3NTA-related proliferative effects are not mediated by an internal formation of FeNTA.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Bromodeoxyuridine; Calcium; Carcinogenicity Tests; Cell Division; Deoxyguanosine; Ferric Compounds; Immunohistochemistry; Iron; Kidney; Kidney Diseases; Lipid Peroxidation; Male; Nitrilotriacetic Acid; Rats; Rats, Wistar; Sodium; Zinc

Ferric nitrilotriacetate (Fe-NTA) is a renal toxicant and carcinogen in rats and mice. We found that its administration results in formation of 4-hydroxy-2-nonenal (HNE) in the renal proximal tubule cells of rats, and 8-hydroxydeoxyguanosine (8-OHdG) adducts in their DNA, suggesting a role for oxidative stress. Since 2-mercaptoethane sulfonate (MESNA) and N-acetylcysteine (NAC), administered orally, have been shown to increase the kidney levels of free thiol groups, their influence on the renal toxicity and carcinogenicity induced by Fe-NTA was examined in the present study. Male Wistar rats were intraperitoneally injected with Fe-NTA (12 mg Fe/kg), and MESNA (100 mg/kg) or NAC (200 mg/kg) was given orally 1 h before and 1 h after this treatment. The animals were killed for tissue analyses 3 h after the Fe-NTA exposure. In accord with our previous reports, HNE-modified protein was detected in the proximal tubules of Fe-NTA-treated rats by means of immunohistochemistry. Likewise, levels of 8-OHdG in the renal nuclear DNA, lipid peroxides as thiobarbituric acid-reactive substances in the kidneys, and blood urea nitrogen and creatinine in the serum were significantly increased by the Fe-NTA treatment. All of these changes were completely inhibited by oral administration of MESNA or NAC. These results suggest that both of these compounds can prevent the oxidative stress induced by Fe-NTA.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Acetylcysteine; Aldehydes; Animals; Antioxidants; Carcinogens; Deoxyguanosine; DNA; DNA Damage; Ferric Compounds; Kidney; Kidney Diseases; Kidney Tubules, Proximal; Lipid Peroxidation; Male; Mesna; Nitrilotriacetic Acid; Oxidative Stress; Rats; Rats, Wistar; Thiobarbituric Acid Reactive Substances

The effects of the antioxidants, glutathione (GSH) and its precursor cysteine (Cys) on oxidative damage induced by ferric nitrilotriacetate (Fe-NTA) were examined. Fe-NTA-associated oxidative stress caused the depletion of renal cellular GSH content. Administration of exogenous GSH and Cys suppressed 8-hydroxydeoxyguanosine (8-OH-dG) formation, an indicator of oxidative DNA damage and nephrotoxicity following Fe-NTA treatment. This suggests that generation of free radicals may be causally involved in oxidative lesion generation. Since lipid peroxidation was found to be inhibited only by GSH and not Cys treatment, this suggests that this effect and the DNA damage might be mediated by different pathways. Fe-NTA-associated oxidative stress in renal tubular cells might thus operate via both intracellular and external space modes.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Antioxidants; Blood Urea Nitrogen; Cysteine; Deoxyguanosine; DNA Damage; Ferric Compounds; Free Radicals; Glutathione; Kidney Diseases; Lipid Peroxidation; Male; Nitrilotriacetic Acid; Organ Size; Rats; Rats, Inbred Strains; Sulfhydryl Compounds

8-Hydroxydeoxyguanosine (8-OH-dG) was examined in the kidneys of rats after single i.p. administration of ferric nitrilotriacetate (Fe-NTA) for variable periods of time at various doses along with the measurement of lipid peroxidation and serum biochemical parameters and histopathological examination. Though lipid peroxide level increased rapidly and decreased sharply after reaching a much higher peak 1 h after treatment, significant higher levels of 8-OH-dG were observed at 1, 6 and 24 h after injection. On the other hand, the increase of 8-OH-dG formation was observed in a similar dose-dependent manner to the appearance of nephrotoxic responses in terms of serum biochemical and histopathological changes.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Blood Urea Nitrogen; Deoxyguanosine; DNA Damage; Dose-Response Relationship, Drug; Ferric Compounds; Kidney Diseases; Lipid Peroxidation; Male; Nitrilotriacetic Acid; Oxidation-Reduction; Rats; Rats, Inbred Strains; Staining and Labeling; Time Factors