8-hydroxy-2--deoxyguanosine and Renal-Insufficiency

This study aimed to investigate the protective effects of berberine (BBR) against D-galactose (D-gal)-induced renal aging in rats, pointing to its ability to modulate phosphatase and tensin homolog deleted on chromosome ten (PTEN)/Akt signalling, and to attenuate oxidative stress, inflammation and apoptosis. Renal aging was induced by subcutaneous injection of D-gal for six consecutive weeks along with simultaneous oral administration of BBR and compared to control rats and rats received individual doses of either drug. BBR treatment significantly reduced the serum levels of urea and creatinine, retrieved the alterations in kidney histopathology, and restored redox balance evidenced by alleviations of the level of malondialdehyde, 8-hydroxy-2'-deoxyguanosine and activating heme oxygenase-1 enzyme. Moreover, it markedly reduced the serum levels of pro-inflammatory mediators, along with down-regulation of PTEN expression, enhanced Akt activity, as well as significantly higher immunostaining of the anti-apoptotic marker (Bcl-2). These findings hold a great promise for the use of BBR as a protecting agent against renal aging.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Administration, Oral; Aging; Animals; Anti-Inflammatory Agents; Antioxidants; Apoptosis; Berberine; Creatinine; Galactose; Gene Expression Regulation; Heme Oxygenase-1; Inflammation; Kidney; Male; Malondialdehyde; Oxidative Stress; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-bcl-2; PTEN Phosphohydrolase; Rats; Renal Insufficiency; Signal Transduction; Urea

Diabetic nephropathy is characterized by abnormal angiogenesis, and this is driven by several factors, including hyperglycaemia and ischaemia. We investigated the role of vascular endothelial growth factor receptor-2 (VEGFR-2) blockade and its effects on diabetic nephropathy.. Male db/db and db/m mice received long-term treatment with dRK6, an arginine-rich anti-VEGF hexapeptide, for 12 weeks or short-term treatment for only the first 4 weeks, starting from 8 weeks of age.. The urinary albuminuria and VEGF excretion varied according to the duration of diabetes, and the urinary VEGF levels were strongly correlated with the levels of albuminuria. Diabetes increased the VEGFR-2 expression in the kidneys. At the end of the 12-week study, compared with the db/db control mice, the db/db mice with long-term dRK6 treatment, which selectively inhibited VEGFR-2, had more albuminuria, related to weak nephrin signalling and advanced renal phenotypes, which were associated with hypoxia-oxidative stress, and an increased number of apoptotic endothelial cells. Interestingly, these changes were related to a decrease in phospho-Akt/eNOS-NO bioavailability. On the in vitro study, dRK6 increased the number of apoptotic human umbilical vein endothelial cells (HUVECs) in the high glucose media by blocking phospho-Akt/eNOS-NO signalling, and this was related to the increased oxidative stress. The short-term inhibition of VEGFR-2 neither improved the albuminuria nor the renal phenotype induced by diabetes.. Long-term selective blockade of VEGFR-2 by dRK6 had deleterious renal effects, and this was associated with downregulation of the Akt/eNOS-NO axis in db/db mice. Short-term VEGFR-2 blockade did not improve the renal phenotypes and the albuminuria. These findings suggest that VEGF-A-VEGFR-2 inhibition, regardless of how long it may be, does not ameliorate diabetic nephropathy in type 2 diabetes.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Albuminuria; Animals; Apoptosis; Blotting, Western; Cell Proliferation; Deoxyguanosine; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Endothelium, Vascular; Immunoenzyme Techniques; Male; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Nitric Oxide; Nitric Oxide Synthase Type III; Obesity; Oligopeptides; Proto-Oncogene Proteins c-akt; Renal Insufficiency; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-2

Excessive prepubertal salt intake permanently increases blood pressure (BP). We examined the role that the mineralocorticoid receptor (MR) plays in the salt-induced hypertension and renal damage of prepubertal Dahl salt-sensitive (SS) rats.. Prepubertal (6 weeks old) and adult (10 weeks old) Dahl SS rats fed a high (8.0%) salt (HS) diet for 10 weeks were compared in terms of BP and renal function. The effect of treatment between the ages of 4 and 10 weeks with the MR antagonist eplerenone (0.125% in chow), the vasodilator hydralazine (50 mg/kg/day in drinking water) or the superoxide dismutase mimetic 4-hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl (tempol) (0.6 mmol/kg/day in drinking water) on the BP and renal function of prepubertal rats fed a HS diet for 10 weeks was also examined.. Excessive salt intake starting in prepuberty was associated with a higher BP increase and greater proteinuria than if it started in adulthood. Eplerenone moderately reduced BP and markedly improved renal injury during its administration in prepubertal rats. These effects continued after drug discontinuation. Hydralazine greatly decreased BP and reduced proteinuria, but these effects were completely lost after drug discontinuation. Excessive salt increased urinary 8-hydroxy-2'-deoxyguanosine levels, intrarenal macrophage infiltration and renal plasminogen activator inhibitor-1 and transforming growth factor-beta mRNA expression. Eplerenone, but not hydralazine, attenuated these salt-induced inflammatory reactions. Tempol improved salt-induced hypertension and renal injury, even after its discontinuation.. Dahl SS rats exposed to excessive salt in prepubescence show a permanent increase in susceptibility to salt-induced hypertension and proteinuria. MR activation may promote these effects at least in part by inducing oxidation and inflammation.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Antihypertensive Agents; Antioxidants; Blood Pressure; Cyclic N-Oxides; Deoxyguanosine; Eplerenone; Hydralazine; Hypertension; Kidney; Male; Mineralocorticoid Receptor Antagonists; Rats; Rats, Inbred Dahl; Receptors, Mineralocorticoid; Renal Insufficiency; Sodium Chloride, Dietary; Spin Labels; Spironolactone

Renal ischemia-reperfusion injury (IRI), leading to acute kidney injury, is a frequent complication with renal transplantation and it is associated with graft function. Its pathogenesis involves ischemia, vascular congestion and reactive oxygen metabolites. Carvedilol is an antihypertensive drug with potent anti-oxidant properties. In this study we investigated the protective effects of carvedilol in a rat renal IRI model.. Twenty-four rats were randomized into sham, untreated control and carvedilol (2 mg/kg 30 min before surgery and 12 hr after reperfusion) treatment groups and were subjected to 60 min of left renal ischemia followed by reperfusion at 24, 48, 96 and 168 hr.. Treatment with carvedilol significantly decreased plasma creatinine levels after IRI (up to 168 hr) compared to controls (P < 0.001), suggesting an improvement in renal function. Histopathological analysis revealed decreased IRI-induced damage in kidneys from carvedilol-treated rats. A significant increase in the expression levels of Cu/Zn superoxide dismutase and reduction of 8-hydroxydeoxyguanosine and apoptosis levels (P < 0.005) suggested a protective effect after treatment with carvedilol.. Our findings suggest that carvedilol ameliorates IRI resulting in improved renal function.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Antihypertensive Agents; Apoptosis; Carbazoles; Carvedilol; Creatinine; Deoxyguanosine; Disease Models, Animal; Epithelial Cells; Kidney Tubules; Male; Oxidative Stress; Propanolamines; Rats; Rats, Sprague-Dawley; Renal Insufficiency; Reperfusion Injury; Superoxide Dismutase

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