title: The Effect of Aging on Mitochondrial Complex I and the Extent of Oxidative Stress in the Rat Brain Cortex.
abstract: One of the characteristic features of the aging is dysfunction of mitochondria. Its role in the regulation of metabolism and apoptosis suggests a possible link between these cellular processes. This study investigates the relationship of respiratory complex I with aging-related oxidative stress in the cerebral mitochondria. Deterioration of complex I seen in senescent (26-months old) mitochondria was accompanied by decline in total thiol group content, increase of HNE and HNE-protein adducts as well as decreased content of complex I subunits, GRIM-19 and NDUFV2. On the other hand, decline of complex I might be related with the mitochondrial apoptosis through increased Bax/Bcl-2 cascade in 15-month old animal brains. Higher amount of Bcl-2, Bcl-xL with the lower content of GRIM-19 could maintain to some extent elevated oxidative stress in mitochondria as seen in the senescent group. In the cortical M1 region increased presence of TUNEL+ cells and more than 20-times higher density of Fluoro-Jade C+ cells in 26-months old was observed, suggesting significant neurodegenerative effect of aging in the neuronal cells. Our study supports a scenario in which the age-related decline of complex I might sensitize neurons to the action of death agonists, such as Bax through lipid and protein oxidative stimuli in mitochondria. Although aging is associated with oxidative stress, these changes did not increase progressively with age, as similar extent of lesions was observed in oxidative stress markers of the both aged groups.
authors.affiliation: Department of Medical Biochemistry, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Mala Hora 4D, 036 01, Martin, Slovakia. tatarkova@jfmed.uniba.sk.
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Tatarkova
authors.affiliation: Department of Histology and Embryology, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia.
authors.forename: Maria
authors.initials: M
authors.lastname: Kovalska
authors.affiliation: Department of Medical Biochemistry, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Mala Hora 4D, 036 01, Martin, Slovakia.
authors.forename: Veronika
authors.initials: V
authors.lastname: Timkova
authors.affiliation: Department of Medical Biochemistry, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Mala Hora 4D, 036 01, Martin, Slovakia.|Biomedical Center Martin, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia.
authors.forename: Peter
authors.initials: P
authors.lastname: Racay
authors.affiliation: Department of Medical Biochemistry, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Mala Hora 4D, 036 01, Martin, Slovakia.|Biomedical Center Martin, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia.
authors.forename: Jan
authors.initials: J
authors.lastname: Lehotsky
authors.affiliation: Department of Medical Biochemistry, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Mala Hora 4D, 036 01, Martin, Slovakia.|Biomedical Center Martin, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia.
authors.forename: Peter
authors.initials: P
authors.lastname: Kaplan
mesh_terms: D000375:Aging / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism* / Q000473:pathology; D042967:Electron Transport Complex I / Q000378:metabolism*; D015227:Lipid Peroxidation / Q000502:physiology; D008297:Male; D008928:Mitochondria / Q000378:metabolism* / Q000473:pathology; D018384:Oxidative Stress / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D042967:Electron Transport Complex I
keywords: Aging cortex; Apoptosis; Complex I; Mitochondria; Oxidative stress