Feeding Entrainment of the Zebrafish Circadian Clock Is Regulated by the Glucocorticoid Receptor

Cells. 2019;8(11):1342 DOI 10.3390/cells8111342

 

Journal Homepage

Journal Title: Cells

ISSN: 2073-4409 (Online)

Publisher: MDPI AG

LCC Subject Category: Science: Biology (General)

Country of publisher: Switzerland

Language of fulltext: English

Full-text formats available: PDF, HTML

 

AUTHORS

Elisa Morbiato (Department of Life Sciences and Biotechnology, University of Ferrara, 44121 Ferrara, Italy)
Elena Frigato (Department of Life Sciences and Biotechnology, University of Ferrara, 44121 Ferrara, Italy)
Alberto Dinarello (Department of Biology, University of Padova, 35131 Padova, Italy)
Francesca Maradonna (Department of Life and Environmental Sciences, Polytechnic University of Marche, 60131 Ancona, Italy)
Nicola Facchinello (Department of Biology, University of Padova, 35131 Padova, Italy)
Francesco Argenton (Department of Biology, University of Padova, 35131 Padova, Italy)
Oliana Carnevali (Department of Life and Environmental Sciences, Polytechnic University of Marche, 60131 Ancona, Italy)
Luisa Dalla Valle (Department of Biology, University of Padova, 35131 Padova, Italy)
Cristiano Bertolucci (Department of Life Sciences and Biotechnology, University of Ferrara, 44121 Ferrara, Italy)

EDITORIAL INFORMATION

Blind peer review

Editorial Board

Instructions for authors

Time From Submission to Publication: 11 weeks

 

Abstract | Full Text

Glucocorticoids (GCs) are steroid hormones mainly acting as key regulators of body homeostasis and stress responses. Their activities are primarily based on the binding to the GC receptor (GR), a member of the nuclear receptor family, that regulates tissue-specific sets of genes. GCs secretion follows a circadian rhythmicity with a peak linked to the animal&#8217;s activity phase. In mammals, GCs are also implicated in feeding entrainment mechanisms as internal zeitgeber. Here, we investigated, by means of behavioural and molecular approaches, the circadian clock and its regulation by light and food in wild-type (WT) and null glucocorticoid receptor (gr<sup>&#8722;</sup><sup>/</sup><sup>&#8722;</sup>) zebrafish larvae, juveniles and adults. In both WT and gr<sup>&#8722;</sup><sup>/</sup><sup>&#8722;</sup> larvae and adults, behavioural activity and clock gene expression were entrained to the light&#8722;dark (LD) cycle and rhythmic in constant conditions. Differences in the pattern of clock genes&#8217; expression indicated a modulatory role of GCs. A significant role of Gr was detected in the feeding entrainment which was absent or markedly dampened in mutants. Furthermore, the expression of two clock-regulated genes involved in glucidic and lipidic metabolism was altered, highlighting the participation of GCs in metabolic processes also in fish. Taken together, our results confirmed the role of GC-mediated Gr signaling in the feeding entrainment in a non-mammalian species, the zebrafish.