Aging modifies circadian expression of antioxidant enzymes in cerebellum

CASTRO-PASCUAL, I; ALTAMIRANO FG; LACOSTE MG; ANZULOVICH AC; FERRAMOLA, M.

Mar del Plata

Congreso; XXX Congreso de la SAN; 2015

Sociedad Argentina de Neurociencias

Cerebellum functions decline in older adults and are susceptible to oxidative stress. Previously, we observed oscillating 24h-patterns of Catalase (CAT) activity and GSH levels are modified in the cerebellum of aged rats. The objectives of this study were: 1) to analyze the CAT and GSH peroxidase 4 (GPx4) expression as well as the clock factor BMAL1 protein levels throughout a 24h period in the rat cerebellum and 2) to investigate whether circadian rhythms of antioxidant enzymes and BMAL1 are modified in aged rats. Holtzman rats from young (3-month old) and aged (22-month old) groups were maintained under cosntant darkness conditions during 15 days before the experiment. CAT and GPx4 mRNA as well as BMAL1 protein levels were determined in cerebellum samples isolated every 4 h during a 24h-period. We observed BMAL1 protein varies significantly throughout a 24h period in young and aged rats. However, aging phase shifted BMAL1 protein rhythmicity and reduced the rhythm mesor. We also observed GPx4 mRNA circadian rhythm. In this case, aging reduced the rhythm's mesor. However, we did not observed a 24-h variation in CAT expression, neither in young or aged animals. Aging affects circadian rhythms of antioxidant enzymes and BMAL1 clock factor in a different way. This might indicate other factors are mediating circadian regulation of antioxidant enzymes expression.