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Retinoic acid receptors move in time with the clock in the hippocampus. Effect of a vitamin-A-deficient diet.
Navigatore-Fonzo, Lorena S; Golini, Rebeca L; Ponce, Ivana T; Delgado, Silvia M; Plateo-Pignatari, Maria G; Gimenez, María S; Anzulovich, Ana C.
Afiliación
  • Navigatore-Fonzo LS; Laboratory of Chronobiology, Multidisciplinary Institute of Biological Research San Luis (IMIBIO-SL), National Council of Science and Technology (CONICET), National University of San Luis (UNSL). Chacabuco y Pedernera, D5700HHW, San Luis, Argentina.
J Nutr Biochem ; 24(5): 859-67, 2013 May.
Article en En | MEDLINE | ID: mdl-22902328
An endogenous time-keeping mechanism controls circadian biological rhythms in mammals. Previously, we showed that vitamin A deficiency modifies clock BMAL1 and PER1 as well as BDNF and neurogranin daily rhythmicity in the rat hippocampus when animals are maintained under 12-h-light:12-h-dark conditions. Retinoic acid nuclear receptors, retinoic acid receptors (RARs) and retinoid X receptors (RXRs), have been detected in the same brain area. Our objectives were (a) to analyze whether RARα, RARß and RXRß exhibit a circadian variation in the rat hippocampus and (b) to investigate the effect of a vitamin-A-deficient diet on the circadian expression of BMAL1, PER1 and retinoic acid receptors (RARs and RXRß) genes. Holtzman male rats from control and vitamin-A-deficient groups were maintained under 12-h-light:12-h-dark or 12-h-dark:12-h-dark conditions during the last week of treatment. RARα, RARß, RXRß, BMAL1 and PER1 transcript and protein levels were determined in hippocampus samples isolated every 4 h in a 24-h period. Regulatory regions of RARs and RXRß genes were scanned for clock-responsive sites, while BMAL1 and PER1 promoters were analyzed for retinoic acid responsive elements and retinoid X responsive elements. E-box and retinoid-related orphan receptor responsive element sites were found on regulatory regions of retinoid receptors genes, which display an endogenously controlled circadian expression in the rat hippocampus. Those temporal profiles were modified when animals were fed with a vitamin-A-deficient diet. Similarly, the nutritional vitamin A deficiency phase shifted BMAL1 and abolished PER1 circadian expression at both mRNA and protein levels. Our data suggest that vitamin A deficiency may affect the circadian expression in the hippocampus by modifying the rhythmic profiles of retinoic acid receptors.
Asunto(s)

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Deficiencia de Vitamina A / Ritmo Circadiano / Receptores de Ácido Retinoico / Receptor beta X Retinoide / Dieta / Hipocampo Límite: Animals Idioma: En Revista: J Nutr Biochem Asunto de la revista: BIOQUIMICA / CIENCIAS DA NUTRICAO Año: 2013 Tipo del documento: Article País de afiliación: Argentina Pais de publicación: Estados Unidos

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Deficiencia de Vitamina A / Ritmo Circadiano / Receptores de Ácido Retinoico / Receptor beta X Retinoide / Dieta / Hipocampo Límite: Animals Idioma: En Revista: J Nutr Biochem Asunto de la revista: BIOQUIMICA / CIENCIAS DA NUTRICAO Año: 2013 Tipo del documento: Article País de afiliación: Argentina Pais de publicación: Estados Unidos