[Study of oxidative stress in advanced kidney disease]. / Estudio del estrés oxidativo en enfermedad renal avanzada.

INTRODUCTION: Introduction Patients with Chronic renal Disease (CRD) often have cardiovascular disease that is the main cause of morbidity and mortality. Oxidative stress and a subclinical inflammation are crucial factors in its development. The aim of this study was to asses the oxidation of the main molecular lines in patients with advanced renal disease without dialysis and to determinate the best biomarker to asses this stress. PATIENTS AND METHODS: We performed an observational study to measure the most important oxidative biomarkers in 32 patients with stage 4 CRD (MDRD = 22.1 +/- 1.08 ml/min) compared with the values obtained in a control group. In peripheral lymphocytes we measured, the lipid peroxidation by Malondialdehyde (MDA) and F2 Isoprostanes in plasma; protein oxidation by glutathione oxidized/reduced ratio (GSSG/GSH) in peripheral lymphocytes and protein carbonyls in plasma and the oxidative damage in genetic material by modified nucleotide base 8-deoxiguanosina oxo -(8-oxo-dG), after isolating nuclear and mitochondrial DNA. We also studied the antioxidant defenses with superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GSR) and catalase (CAT) in peripheral lymphocytes. We studied the correlation between oxidative stress and the renal function and oxidative stress and co-morbidity factors. RESULTS: All biomarkers showed important differences in comparison with the control subjects. 821.89 +/- 300.47 ng/ml vs. 270 (95.66) * ng/ml (p < 0.000), MDA 0.11 (0.11) * vs. 0.7 +/- 0.31 nmol/mg prot (p <0.000). GSSG / GSH: 6.89 +/- 1.91 vs. 1.39 +/- 0.75 (p <0.000), protein carbonyls: 7.41 +/- 0.84 vs. 3.63 (1.12) *. Nuclear 8-oxo-dG 7.88 (2.32) vs. 2.96 (1.78) * mitochondrial 8-oxo-dG: 15.73 +/- 2.28 vs. 13.85 +/- 1.44 (p <0.05). The Antioxidant enzymes also showed differences. Nuclear 8-oxo-dG demonstrated an important relationship with the rest of biomarkers, homocysteine (r = 0.305, p <0.05), lipoprotein (a) (r = 0.375, p <0.01), mitochondrial 8-oxo-dG (r = 0.411, p <0.05), GSSH/GSH (r = 0.595, p <0.001) and protein carbonyls (r = 0.489, p <0.05). There was an inverse correlation with total protein (r = -0.247, p <0.01), GSH (r = -0.648, p <0.000), GSR (r = -0.563, p <0.001) and SOD (r = -0.497, p <0.000). We did not find any correlation between these parameters and renal function. The presence of diabetes or the treatment with statins did not showed significant differences. * Median (Interquartile range). CONCLUSION: There is an important oxidative stress in patients with advanced renal disease, probably established during early stages of disease. Of the studied parameters, the nuclear 8-oxo-dG is the best marker for oxidative stress in CRD.

Estudio del estrés oxidativo en enfermedad renalavanzada / No disponible

Introducción: El estrés oxidativo es crucial para el desarrollo de arteriosclerosis, principal causa de morbimortalidad en población en prediálisis. Nuestro objetivo fue valorar la oxidación de las principales líneas moleculares y discernir si algún biomarcador tenía mejor comportamiento valorando este estrés. Pacientes y método: Estudio observacional en 32 pacientes con MDRD 22,1 ± 1,08 ml/min. Medimos en linfocitos periféricos: malondialdehído, glutatión oxidado/reducido, 8-oxo-deoxiguanosina nuclear y mitocondrial, superóxido dismutasa, glutatión reductasa, glutatión peroxidasa y catalasa, y en plasma F2 isoprostanos y proteínas carboniladas. Correlacionamos los resultados con función renal y factores comórbidos. Resultados: Todos los biomarcadores tuvieron amplias diferencias significativas cuando se compararon con el grupo control peroxidación lipídica: F2 isoprostanos: 821,89 ± 300,47 ng/ml vs. 270 (95,66)* ng/ml (p <0,000); MDA 0,11 (0,11)* vs. 0,7 ± 0,31 nmol/mg prot (p <0,000). Oxidación proteica: GSSG/GSH: 6,89 ± 1,91 vs. 1,39 ± 0,75 (p <0,000); proteínas carboniladas: 7,41 ± 0,84 vs. 3,63 (1,12)*. Daño material genético: 8-oxo-deoxiguanosina nuclear: 7,88 (2,32)* vs. 2,96 (1,78)* y 8-oxo-dG mitocondrial: 15,73 ± 2,28 vs. 13,85 ± 1.44 (p <0,05). Los valores de las enzimas antioxidantes también obtuvieron amplias diferencias significativas. La molécula 8-oxodeoxiguanosina en DNA nuclear fue la que tuvo una relación significativa con el resto de biomarcadores, con homocisteína (r = 0,305; p <0,05), lipoproteína (a) (r = 0,375; p <0,01), 8-oxo-deoxiguanosina mitocondrial (r = 0,411; p <0,05), GSSG/GSH (r = 0,595; p <0,001) y proteínas carboniladas (r = 0,489; p <0,05), y de forma inversa con las proteínas totales (r = -0,247; p <0,01), GSH (r = -0,648; p <0,000), GRS (r = -0,563; p <0,001) y SOD (-0,497; p <0,000). Ninguno de los parámetros tuvo correlación con la función renal. Tampoco se obtuvieron diferencias significativas con la presencia o no de diabetes o la toma de estatinas. * Mediana (amplitud intercuartil). Conclusión: Existe un elevado estrés oxidativo en los pacientes con enfermedad renal avanzada que probablemente se establezca desde fases tempranas de la enfermedad. Entre todos los parámetros estudiados, la molécula de 8-oxo-dG se comportó como el marcador más idóneo (AU)

Introduction: Patients with Chronic Kidney Disease (CKD) often have cardiovascular disease that is the main cause of morbidity and mortality. Oxidative stress and a subclinical inflammation are crucial factors in its development. The aim of this study was to assess the oxidation of the main molecular groups in patients with advanced renal disease without dialysis and to determinate the best biomarker to assess this stress. Patients and Methods: We performed an observational study to measure the most important oxidative biomarkers in 32 patients with stage 4 CKD (MDRD = 22.1 ± 1.08ml/min) compared with the values obtained in a control group. In the peripheral lymphocytes we measured, the lipid peroxidation by Malondialdehide (MDA) and F2 Isoprostanes in plasma; protein oxidation by glutathione oxidized/reduced ratio (GSSG/GSH) in peripheral lymphocytes and protein carbonyls in plasma and the oxidative damage in genetic material by modified nucleotide base 8-deoxiguanosina oxo ¿(8-oxodG), after isolating nuclear and mitochondrial DNA. We also studied the antioxidant defences with superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GSR) and catalase (CAT) in peripheral lymphocytes. We studied the correlation between oxidative stress and the renal function and oxidative stress and co-morbidity factors. Results: All biomarkers showed important differences in comparison with the control subjects. F2 Isoprostanes: 821.89 ± 300.47ng/ml vs. 270 (95.66) * ng/ml (p < 0.000), MDA 0.11 (0.11) * vs. 0.7 ± 0.31nmol/mg prot (p < 0.000). GSSG/GSH: 6.89 ± 1.91 vs. 1.39 ± 0.75 (p < 0.000), protein carbonyls: 7.41 ± 0.84 vs. 3.63 (1.12) *. Nuclear 8-oxo-dG 7.88 (2.32) vs. 2.96 (1.78) * mitochondrial 8-oxo-dG: 15.73 ± 2.28 vs. 13.85 ± 1.44 (p < 0.05). The Antioxidant enzymes also showed differences. Nuclear 8-oxo-dG demonstrated an important relationship with the rest of the biomarkers, homocystein (r = 0.305, p < 0.05), lipoprotein (a) (r = 0.375, p < 0.01), mitochondrial 8-oxodG (r = 0.411, p < 0.05), GSSH/GSH (r= 0.595, p < 0.001) and protein carbonyls (r = 0.489, p < 0.05). There was an inverse correlation with total protein (r = -0.247, p < 0.01), GSH (r = -0.648, p < 0.000), GSR (r = -0.563, p < 0.001) and SOD (r = -0.497, p < 0.000). We did not find any correlation between these parameters and renal function. The presence of diabetes or the treatment with statins did not show significant differences. * Median (Interquartile range). Conclusion: There is an important oxidative stress in patients with advanced renal disease, probably established during the early stages of disease. Of the studied parameters, the nuclear 8-oxo-dG is the best marker for oxidative stress in CRD (AU)

Aplidin induces JNK-dependent apoptosis in human breast cancer cells via alteration of glutathione homeostasis, Rac1 GTPase activation, and MKP-1 phosphatase downregulation.

Aplidin is an antitumor agent in phase II clinical trials that induces apoptosis through the sustained activation of Jun N-terminal kinase (JNK). We report that Aplidin alters glutathione homeostasis increasing the ratio of oxidized to reduced forms (GSSG/GSH). Aplidin generates reactive oxygen species and disrupts the mitochondrial membrane potential. Exogenous GSH inhibits these effects and also JNK activation and cell death. We found two mechanisms by which Aplidin activates JNK: rapid activation of Rac1 small GTPase and downregulation of MKP-1 phosphatase. Rac1 activation was diminished by GSH and enhanced by L-buthionine (SR)-sulfoximine, which inhibits GSH synthesis. Downregulation of Rac1 by transfection of small interfering RNA (siRNA) duplexes or the use of a specific Rac1 inhibitor decreased Aplidin-induced JNK activation and cytotoxicity. Our results show that Aplidin induces apoptosis by increasing the GSSG/GSH ratio, a necessary step for induction of oxidative stress and sustained JNK activation through Rac1 activation and MKP-1 downregulation.