title: Pinealectomy interferes with the circadian clock genes expression in white adipose tissue.
abstract: Melatonin, the main hormone produced by the pineal gland, is secreted in a circadian manner (24-hr period), and its oscillation influences several circadian biological rhythms, such as the regulation of clock genes expression (chronobiotic effect) and the modulation of several endocrine functions in peripheral tissues. Assuming that the circadian synchronization of clock genes can play a role in the regulation of energy metabolism and it is influenced by melatonin, our study was designed to assess possible alterations as a consequence of melatonin absence on the circadian expression of clock genes in the epididymal adipose tissue of male Wistar rats and the possible metabolic repercussions to this tissue. Our data show that pinealectomy indeed has impacts on molecular events: it abolishes the daily pattern of the expression of Clock, Per2, and Cry1 clock genes and Pparγ expression, significantly increases the amplitude of daily expression of Rev-erbα, and affects the pattern of and impairs adipokine production, leading to a decrease in leptin levels. However, regarding some metabolic aspects of adipocyte functions, such as its ability to synthesize triacylglycerols from glucose along 24 hr, was not compromised by pinealectomy, although the daily profile of the lipogenic enzymes expression (ATP-citrate lyase, malic enzyme, fatty acid synthase, and glucose-6-phosphate dehydrogenase) was abolished in pinealectomized animals.
authors.affiliation: Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
authors.forename: Talita da Silva Mendes
authors.initials: Tda S
authors.lastname: de Farias
authors.forename: Ariclécio Cunha
authors.initials: AC
authors.lastname: de Oliveira
authors.forename: Sandra
authors.initials: S
authors.lastname: Andreotti
authors.forename: Fernanda Gaspar
authors.initials: FG
authors.lastname: do Amaral
authors.forename: Patrícia
authors.initials: P
authors.lastname: Chimin
authors.forename: André Ricardo Alves
authors.initials: AR
authors.lastname: de Proença
authors.forename: Francisco Leonardo Torres
authors.initials: FL
authors.lastname: Leal
authors.forename: Rogério Antonio Laurato
authors.initials: RA
authors.lastname: Sertié
authors.forename: Amanda Baron
authors.initials: AB
authors.lastname: Campana
authors.forename: Andressa Bolsoni
authors.initials: AB
authors.lastname: Lopes
authors.forename: Arnaldo Henrique
authors.initials: AH
authors.lastname: de Souza
authors.forename: José
authors.initials: J
authors.lastname: Cipolla-Neto
authors.forename: Fabio Bessa
authors.initials: FB
authors.lastname: Lima
mesh_terms: D052436:Adipose Tissue, White / Q000378:metabolism*; D000818:Animals; D002940:Circadian Rhythm / Q000235:genetics* / Q000502:physiology; D015870:Gene Expression / Q000235:genetics* / Q000502:physiology; D008297:Male; D056950:Period Circadian Proteins / Q000235:genetics / Q000378:metabolism*; D010870:Pineal Gland / Q000201:enzymology / Q000502:physiology / Q000601:surgery; D051381:Rats; D017208:Rats, Wistar
chemical_list: D056950:Period Circadian Proteins
keywords: adipose tissue; clock genes; melatonin; metabolism; pinealectomy