Efeitos do Canabidiol sobre parâmetros mitocondriais e apoptóticos em hipocampo de ratos tratados com ferro no período neonatal

• Autor(a) principal: Silva, Vanessa Kappel da
• Data de Publicação: 2018
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da PUC_RS
• Texto Completo: http://tede2.pucrs.br/tede2/handle/tede/7949
• topic: Ferro; Mitocôndria; Apoptose; Doenças Neurodegenerativas; Canabidiol; CIENCIAS BIOLOGICAS::BIOLOGIA GERAL

Brain iron accumulation has been observed both in normal aging and in many neurodegenerative diseases. In previous studies, we have described that brain iron overload results in persistent memory deficits, accompanied by oxidative stress. The high metabolic rate of the nervous system makes mitochondria essential for nerve cells. These organelles control iron homeostasis in its interior and the management of reactive oxygen species. When deregulation in these activities occurs, mitochondrial functioning is compromised, resulting in failures in the energy supply mainly for the synapses. Inadequate functioning of neural circuits may culminate in the activation of cell death pathways, a feature strongly associated with neurodegenerative diseases. In the present study we analyzed the effects of neonatal iron overload on complex I deletions in the mitochondrial DNA ; on methylation and hydroxymethylation of mitochondrial DNA; on mitochondrial proteins involved on iron homeostasis, on the enzymatic activity of Succinate Dehydrogenase and Creatine Kinase, enzymes involved in the cells energy supply; and on proteins involved in apoptotic pathways, such as Caspase 8, Caspase 9, Caspase 3, Cytochrome c, APAF1, and PARP in the hippocampus of adult rats. In addition, we investigated the effects of cannabidiol (CBD), the main non-psychotropic component of Cannabis sativa, in reversing iron-induced effects on all parameters analyzed. Male rats received vehicle or iron carbonyl (30 mg / kg) from the 12th to the 14th postnatal day and were treated with vehicle or CBD (10mg / kg) for 14 days in adulthood. Iron treatment induced increased deletions of mitochondrial DNA and expression of proteins involved in apoptosis, while induced reductions of methylation and hydroxymethylation, enzymatic activity and mitochondrial ferritin, an iron storage protein. CBD reversed iron-induced effects, recovering hydroxymethylation levels, mitochondrial ferritin, Succinate dehydrogenase activity, apoptotic proteins Caspase 3, Caspase 9, PARP and APAF1 at levels comparable to controls. These results suggest that iron can affect mechanisms of mitochondrial functioning and trigger cell death pathways by apoptosis. The reversal of some of these effects by CBD indicates its neuroprotective potential.