title: Environmental enrichment attenuates the age-related decline in the mRNA expression of steroidogenic enzymes and reduces the methylation state of the steroid 5α-reductase type 1 gene in the rat hippocampus.
abstract: We analyzed the effects of aging and environmental enrichment on the mRNA expression and DNA methylation state of steroidogenic enzymes in the hippocampus. The effects of aging were evaluated by comparing young adult (90-day-old) and middle-aged (450-day-old) female Wistar rats. To elucidate the effects of environmental enrichment, a subgroup of middle-aged rats exposed to sensory and social stimulation for 105 days was compared to rats housed under standard laboratory conditions. Aging decreased the transcription of neurosteroidogenic-related genes and increased the promoter methylation state of cytochrome P450 side chain cleavage, 3α-hydroxysteroid dehydrogenase (3α-HSD) and 5α-reductase-1. Exposure of middle-aged rats to environmental enrichment increased mRNA levels of 5α-reductase-1, 3α-HSD and cytochrome P450 17α-hydroxylase/c17,20-lyase and decreased the methylation state of the 5α-reductase-1 gene. Thus, sensory and social stimulation attenuate the age-related decline in the mRNA expression of hippocampal steroidogenic enzymes. Epigenetic mechanisms associated with differential promoter methylation could be involved.
authors.affiliation: Departamento de Bioquímica Clínica y Cuantitativa, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina; Instituto de Salud y Ambiente del Litoral (ISAL), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral-CONICET, Santa Fe, Argentina.
authors.forename: María F
authors.initials: MF
authors.lastname: Rossetti
authors.affiliation: Instituto de Salud y Ambiente del Litoral (ISAL), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral-CONICET, Santa Fe, Argentina.
authors.forename: Jorgelina
authors.initials: J
authors.lastname: Varayoud
authors.affiliation: Instituto de Salud y Ambiente del Litoral (ISAL), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral-CONICET, Santa Fe, Argentina.
authors.forename: Guillermo S
authors.initials: GS
authors.lastname: Moreno-Piovano
authors.affiliation: Instituto de Salud y Ambiente del Litoral (ISAL), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral-CONICET, Santa Fe, Argentina.
authors.forename: Enrique H
authors.initials: EH
authors.lastname: Luque
authors.affiliation: Departamento de Bioquímica Clínica y Cuantitativa, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina; Instituto de Salud y Ambiente del Litoral (ISAL), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral-CONICET, Santa Fe, Argentina. Electronic address: gramos@fbcb.unl.edu.ar.
authors.forename: Jorge G
authors.initials: JG
authors.lastname: Ramos
mesh_terms: D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase / Q000235:genetics* / Q000378:metabolism; D045002:3-alpha-Hydroxysteroid Dehydrogenase (B-Specific) / Q000235:genetics / Q000378:metabolism; D000375:Aging; D000818:Animals; D053898:Biosynthetic Pathways; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D005260:Female; D015870:Gene Expression; D006624:Hippocampus / Q000201:enzymology*; D006799:Housing, Animal; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017208:Rats, Wistar
chemical_list: D012333:RNA, Messenger; D045002:3-alpha-Hydroxysteroid Dehydrogenase (B-Specific); D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase
keywords: Aging; DNA methylation; Environmental enrichment; Hippocampus; Neurosteroidogenic enzymes