Disruption of brain redox homeostasis in glutaryl-CoA dehydrogenase deficient mice treated with high dietary lysine supplementation.

Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.

Molecular genetics and metabolism 2013 Jan

filter terms:

Deficiency of glutaryl-CoA dehydrogenase (GCDH) activity or glutaric aciduria type I (GA I) is an inherited neurometabolic disorder biochemically characterized by predominant accumulation of glutaric acid and 3-hydroxyglutaric acid in the brain and other tissues. Affected patients usually present acute striatum necrosis during encephalopathic crises triggered by metabolic stress situations, as well as chronic leukodystrophy and delayed myelination. Considering that the mechanisms underlying the brain injury in this disease are not yet fully established, in the present study we investigated important parameters of oxidative stress in the brain (cerebral cortex, striatum and hippocampus), liver and heart of 30-day-old GCDH deficient knockout (Gcdh(-/-)) and wild type (WT) mice submitted to a normal lysine (Lys) (0.9% Lys), or high Lys diets (2.8% or 4.7% Lys) for 60 h. It was observed that the dietary supplementation of 2.8% and 4.7% Lys elicited noticeable oxidative stress, as verified by an increase of malondialdehyde concentrations (lipid oxidative damage) and 2-7-dihydrodichlorofluorescein (DCFH) oxidation (free radical production), as well as a decrease of reduced glutathione levels and alteration of various antioxidant enzyme activities (antioxidant defenses) in the cerebral cortex and the striatum, but not in the hippocampus, the liver and the heart of Gcdh(-/-) mice, as compared to WT mice receiving the same diets. Furthermore, alterations of oxidative stress parameters in the cerebral cortex and striatum were more accentuated in symptomatic, as compared to asymptomatic Gcdh(-/-) mice exposed to 4.7% Lys overload. Histopathological studies performed in the cerebral cortex and striatum of these animals exposed to high dietary Lys revealed increased expression of oxidative stress markers despite the absence of significant structural damage. The results indicate that a disruption of redox homeostasis in the cerebral cortex and striatum of young Gcdh(-/-) mice exposed to increased Lys diet may possibly represent an important pathomechanism of brain injury in GA I patients under metabolic stress. Copyright © 2012 Elsevier Inc. All rights reserved.

Citation

Bianca Seminotti, Alexandre Umpierrez Amaral, Mateus Struecker da Rosa, Carolina Gonçalves Fernandes, Guilhian Leipnitz, Silvia Olivera-Bravo, Luis Barbeito, César Augusto J Ribeiro, Diogo Onofre Gomes de Souza, Michael Woontner, Stephen I Goodman, David M Koeller, Moacir Wajner. Disruption of brain redox homeostasis in glutaryl-CoA dehydrogenase deficient mice treated with high dietary lysine supplementation. Molecular genetics and metabolism. 2013 Jan;108(1):30-9