ABSTRACT
BACKGROUND: Complex I (CI) deficiency is the most frequent cause of OXPHOS disorders. Recent studies have shown increases in reactive oxygen species (ROS) production and mitochondrial network disturbances in patients' fibroblasts harbouring mutations in CI subunits. OBJECTIVES: The present work evaluates the impact of mutations in the NDUFA1 and NDUFV1 genes of CI on mitochondrial bioenergetics and dynamics, in fibroblasts from patients suffering isolated CI deficiency. RESULTS: Decreased oxygen consumption rate and slow growth rate were found in patients with severe CI deficiency. Mitochondrial diameter was slightly increased in patients' cells cultured in galactose or treated with 2'-deoxyglucose without evidence of mitochondrial fragmentation. Expression levels of the main proteins involved in mitochondrial dynamics, OPA1, MFN2, and DRP1, were slightly augmented in all patients' cells lines. The study of mitochondrial dynamics showed delayed recovery of the mitochondrial network after treatment with the uncoupler carbonyl cyanide m-chlorophenyl hydrazone (cccp) in patients with severe CI deficiency. Intracellular ROS levels were not increased neither in glucose nor galactose medium in patients' fibroblasts. CONCLUSION: Our main finding was that severe CI deficiency in patients harbouring mutations in the NDUFA1 and NDUFV1 genes is linked to a delayed mitochondrial network recovery after cccp treatment. However, the CI deficiency is neither associated with massive mitochondrial fragmentation nor with increased ROS levels. The different genetic backgrounds of patients with OXPHOS disorders would explain, at least partially, differences in the pathophysiological manifestations of CI deficiency.
Subject(s)
Electron Transport Complex I/metabolism , Energy Metabolism , Fibroblasts/enzymology , Mitochondria/metabolism , Mitochondrial Diseases/genetics , Mutation/genetics , NADH Dehydrogenase/genetics , Acidosis/genetics , Acidosis/metabolism , Acidosis/pathology , Adenosine Triphosphate/metabolism , Blotting, Western , Cells, Cultured , Epilepsy/genetics , Epilepsy/metabolism , Epilepsy/pathology , Flow Cytometry , Fluorescent Antibody Technique , Glycolysis , Humans , Infant , Leukoencephalopathies/genetics , Leukoencephalopathies/metabolism , Leukoencephalopathies/pathology , Male , Mitochondria/drug effects , Mitochondrial Diseases/metabolism , NADH Dehydrogenase/metabolism , Oxygen Consumption , RNA, Messenger/genetics , RNA, Messenger/metabolism , Reactive Oxygen Species/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Skin/cytology , Skin/metabolismABSTRACT
INTRODUCCION: El estrés oxidativo (EO) es importante en la génesis de diversas patologías. Su rol en patología cardiovascular es reconocido, particularmente en isquemia-reperfusión, fenómeno asociado al uso de circulación extracorpórea (CEC) en cardiocirugía. Complicación frecuente es la fibrilación auricular post-operatoria(FAPO), que ha demostrado participación del EO. Estrategias que lo atenúen podrían reducir incidencia de FAPO. Este trabajo busca determinar efectos de un esquema de suplementación para prevenir el EO y FAPO. METODOLOGIA: Ensayo clínico, doble ciego, aleatorizado. A 80 pacientes programados para cardiocirugía con CEC se administró placebo (n=40) o suplementación(n=40), consistiendo desde 7 días antes de la cirugía ácidos grasos poli-insaturados omega-3 (n-3) (2 g/día), y 2 días pre-cirugía se agrega vitamina C (1 g/día) y E (400 UI/día), todo hasta el alta. Se obtuvieron muestras sanguíneas (al ingreso, en suplementación, en cirugía, en postoperatorio y al alta) y auriculares durante cirugía. El estado antioxidante fue medido por la habilidad plasmática para reducir hierro férrico (FRAP) y el índice GSH/GSSG. Se midió actividad de enzimas catalasa, superóxido-dismutasa y glutatión-peroxidasa. Lipoperoxidación fue medida por niveles de malondialdehído. Para variables paramétricas se usó t de student, entre grupos se usó ANOVA-Bonferroni. Significancia fue p<0.05. RESULTADOS: Suplementación con n-3 disminuyó índice GSH/GSSG en 25 por ciento. En postoperatorio hubo 21 por ciento menos de lipoperoxidación y niveles de FRAP 30 por ciento mayores. Actividad de enzimas mostró incremento significativo. Además disminuyó FAPO desde 25 por ciento a 7,5 por ciento. CONCLUSION: Suplementar con n-3 y vitaminas antioxidantes disminuye ocurrencia de FAPO evitando daño miocárdico bioquímico y funcional por EO.
INTRODUCTION: Oxidative stress is important in the genesis of several diseases. Their role in cardiovascular disease is recognized, particularly in ischemia-reperfusion, a phenomenon associated with the use of cardiopulmonary bypass (CPB) in cardiac surgery. Common complication is postoperative atrial fibrillation (FOAP), which has demonstrated participation of oxidative stress, strategies to mitigate what could reduce the occurrence of FOAP. This paper tries to determine the effect of a supplementation scheme to prevent oxidative stress and its consequences. MATERIALS AND METHODS: Randomized, double-blind, controlled trial. Eighty patients scheduled for CCEC received placebo (n = 40) or supplementation (n = 40). Inclusion criteria: Age 30-80 years, sinus rhythm. Exclusion criteria: previous cardiosurgery, paroxysmal atrial fibrillation, congenital heart disease, chronic diseases. The supplementation consisting of n-3 (2 g / day), vitamins C (1 g /day) and E (400 IU / day) from 7, 2 and 2 days before surgery, respectively, until discharge. In atrial tissue and blood samples the plasma ferric reducing ability (FRAP), index GSH/GSSG, activity of catalase, superoxide dismutase and glutathione-peroxidase, and malondialdehyde levels were measured. Protein carbonylationwas measured in atrial tissue. Parametric variables expressed as mean and standard error were analyzed with students t-test, groups were compared using ANOVA-Bonferroni. Significance was p <0.05. RESULTS: The supplementation reduced the incidence of FOAP, lipid peroxidation and protein carbonylation in 73, 21 and 19 percent (p <0.05), respectively, and increased the FRAP (30 percent) and activity of antioxidant enzymes (p <0.05). CONCLUSIONS: Antioxidant supplementation decreases FOAP probably avoiding damage by oxidative stress.