Age-related changes in hippocampal estrogen receptor alpha in female mice.

MORENO-PIOVANO G; DUDIUK C; ROSSETTI MF; VARAYOUD, JORGELINA; MUÑOZ DE TORO, MÓNICA; LUQUE EH; RAMOS JG

Congreso; II Reunión Conjunta de Neurociencias.; 2010

A good amount of evidence exists associating estrogens with hippocampal activity, an area of brain related to cognition and memory. The biological effects of estrogen are mainly mediated by estrogen receptors (ERs) which in turn are regulated by several factors including age, sex and gonadal steroid hormones. While the molecular actions of steroid hormones mediated through their receptors have been extensively studied, considerably less is known about the molecular mechanisms that regulate  the  expression  of  ERs themselves. In the present study, to reveal the effects of normal aging on ERa expression in the hippocampus, we examined ERa expression using young (4 month, control group) and adult (11 months) intact CF-1 female mice. By microsurgery complete hippocampus were extracted, which were individually processed. The   expression   of   ERa mRNA and relative transcriptional activity of promoter A, C and F were evaluated by real time RT- PCR. Adult  mice  showed  a  significant  decrease  in  the expression  of  ERa  total mRNA  when  compared  with  controls  (p <0.05). In considering the relative activity of each of the ERa gene promoters was observed that adult animals showed a decrease in the activity of promoters A and C (p <0.001), while F promoter activity remained unchanged (p = 0.99). These results demonstrate that aging is associated with a decrease in the expression of ERa in the hippocampus. This down-regulation would be mediated, at least in part, by decreasing the activity of promoters A and C of the receptor gene.