L-2-Hydroxyglutaric aciduria (L-2-HGA) is an inherited neurometabolic disorder caused by deficient activity of L-2-hydroxyglutarate
dehydrogenase. L-2-Hydroxyglutaric
acid (L-2-HG) accumulation in the brain and
biological fluids is the biochemical hallmark of this disease. Patients present exclusively neurological symptoms and brain abnormalities, particularly in the cerebral cortex, basal ganglia, and cerebellum. Since the pathogenesis of this disorder is still poorly established, we investigated the short-lived effects of an intracerebroventricular injection of L-2-HG to neonatal rats on redox homeostasis in the cerebellum, which is mostly affected in this disorder. We also determined immunohistochemical landmarks of neuronal viability (NeuN),
astrogliosis (S100B and GFAP), microglia activation (Iba1), and myelination (MBP and
CNPase) in the cerebral cortex and striatum following L-2-HG administration. Finally, the neuromotor development and cognitive abilities were examined. L-2-HG elicited oxidative stress in the cerebellum 6 h after its injection, which was verified by increased
reactive oxygen species production,
lipid oxidative damage, and altered
antioxidant defenses (decreased concentrations of
reduced glutathione and increased
glutathione peroxidase and
superoxide dismutase activities). L-2-HG also decreased the content of NeuN, MBP, and
CNPase, and increased S100B, GFAP, and Iba1 in the cerebral cortex and striatum at postnatal days 15 and 75, implying long-standing neuronal loss,
demyelination, astrocyte reactivity, and increased inflammatory response, respectively. Finally, L-2-HG administration caused a delay in neuromotor development and a deficit of cognition in adult animals. Importantly, the
antioxidant melatonin prevented L-2-HG-induced deleterious neurochemical, immunohistochemical, and behavioral effects, indicating that oxidative stress may be central to the pathogenesis of brain damage in
L-2-HGA.