Differential effect of retinoic acid and triiodothyronine on the age-related hypo-expression of neurogranin in rat.
Neurobiology of Aging. 2005-05-01; 26(5): 729-738
DOI: 10.1016/j.neurobiolaging.2004.06.004
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1. Neurobiol Aging. 2005 May;26(5):729-38.
Differential effect of retinoic acid and triiodothyronine on the age-related
hypo-expression of neurogranin in rat.
Féart C(1), Mingaud F, Enderlin V, Husson M, Alfos S, Higueret P, Pallet V.
Author information:
(1)Unité de Nutrition et Signalisation Cellulaire (E.A. MENRT; USC INRA) ISTAB,
Avenue des Facultés, Université Bordeaux I, 33405 Talence cedex, France.
Given the important role of retinoids and thyroid hormone for optimal brain
functioning and the tenuous relationship between retinoic acid (RA) and
triiodothyronine (T3) signalings, we compared the effects of RA or T3
administrations on RA and T3 nuclear receptors (RAR, RXR and TR) and on their
target genes, neuromodulin (GAP43) and neurogranin (RC3) in 24-month-old rats.
Quantitative real time PCR and western blot analysis allowed us to verify that
retinoid and thyroid signalings and GAP43 and RC3 expression are affected by age.
By in situ hybridization we observed a decreased expression of RC3 in
hippocampus, striatum and cerebral cortex. RARbeta, RXRbeta/gamma and GAP43 were
up-regulated by RA as well as T3 treatment. The abundance of TRalpha/beta mRNA
and RC3 expression were only increased by T3 administration in the whole brain.
This up-regulator effect of T3 on RC3 was only observed in the striatum. During
aging, T3 become a limiting factor alone able to correct the age-related
concomitant hypo-activation of retinoid and thyroid signalings and alterations of
synaptic plasticity.
DOI: 10.1016/j.neurobiolaging.2004.06.004
PMID: 15708448 [Indexed for MEDLINE]