Disturbance of energy and redox homeostasis and reduction of Na+,K+-ATPase activity provoked by in vivo intracerebral administration of ethylmalonic acid to young rats

• Published in: Biochimica et biophysica acta 2015-05, Vol.1852 (5), p.759-767
• Main Authors: Ritter, Luciana, Kleemann, Daniele, Hickmann, Fernanda Hermes, Amaral, Alexandre Umpierrez, Sitta, Ângela, Wajner, Moacir, Ribeiro, César Augusto João
• Format: Article
• Language: English
• Subjects: Acetylcysteine - pharmacology; Animals; Antioxidants - pharmacology; Carbon Dioxide - metabolism; Corpus Striatum - drug effects; Corpus Striatum - metabolism; Electron Transport Complex II - metabolism; Electron Transport Complex III - metabolism; Energy metabolism; Energy Metabolism - drug effects; Ethylmalonic acid; Glucose - metabolism; Glutathione - metabolism; Homeostasis - drug effects; Injections, Intraventricular; Lactates - metabolism; Male; Malonates - administration & dosage; Malonates - pharmacology; Malondialdehyde - metabolism; Melatonin - pharmacology; Oxidation-Reduction - drug effects; Rats, Wistar; Redox homeostasis; Sodium-Potassium-Exchanging ATPase - metabolism; Striatum; Synapses - drug effects; Synapses - enzymology; Synaptic Na+,K+-ATPase
• ISSN: 0925-4439; 0006-3002; 1879-260X
• DOI: 10.1016/j.bbadis.2015.01.003

Ethylmalonic acid (EMA) accumulation occurs in various metabolic diseases with neurological manifestation, including short acyl-CoA dehydrogenase deficiency (SCADD) and ethylmalonic encephalopathy (EE). Since pathophysiological mechanisms responsible for brain damage in these disorders are still poorly understood, we investigated the ex vivo effects of acute intrastriatal administration of EMA on important parameters of energy and redox homeostasis in striatum from young rats. We evaluated CO2 production from glucose, glucose utilization and lactate production, as well as the activities of the citric acid cycle (CAC) enzymes, the electron transfer chain (ETC) complexes II–IV (oxidative phosphorylation, OXPHOS) and synaptic Na+,K+-ATPase. We also tested the effect of EMA on malondialdehyde (MDA) levels (marker of lipid oxidation) and reduced glutathione (GSH) levels. EMA significantly reduced CO2 production, increased glucose utilization and lactate production, and reduced the activities of citrate synthase and of complexes II and II–III of the ETC, suggesting an impairment of CAC and OXPHOS. EMA injection also reduced Na+,K+-ATPase activity and GSH concentrations, whereas MDA levels were increased. Furthermore, EMA-induced diminution of Na+,K+-ATPase activity and reduction of GSH levels were prevented, respectively, by the antioxidants melatonin and N-acetylcysteine, indicating that reactive species were involved in these effects. Considering the importance of CAC and ETC for energy production and Na+,K+-ATPase for the maintenance of the cell membrane potential, the present data indicate that EMA compromises mitochondrial homeostasis and neurotransmission in striatum. We presume that these pathomechanisms may be involved to a certain extent in the neurological damage found in patients affected by SCADD and EE. •EMA accumulation is observed in SCAD deficiency and ethylmalonic encephalopathy.•EMA compromises mitochondrial homeostasis and neurotransmission in rat striatum in vivo.•EMA compromises redox homeostasis in rat striatum in vivo.•Melatonin and N-acetylcysteine prevented EMA-induced biochemical alterations in striatum.•Energetic and redox alterations may be involved in neuropathology of EMA-related disorders.