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BioMed Research International
Volume 2017, Article ID 8459385, 14 pages
Research Article

Dexamethasone Modulates Nonvisual Opsins, Glucocorticoid Receptor, and Clock Genes in Danio rerio ZEM-2S Cells

Department of Physiology, Institute of Biosciences, University of Sao Paulo, Sao Paulo, SP, Brazil

Correspondence should be addressed to Ana Maria de Lauro Castrucci;

Received 10 October 2016; Revised 19 March 2017; Accepted 22 March 2017; Published 14 May 2017

Academic Editor: Giuseppe Piccione

Copyright © 2017 Jennifer Caroline Sousa et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Here we report, for the first time, the differential cellular distribution of two melanopsins (Opn4m1 and Opn4m2) and the effects of GR agonist, dexamethasone, on the expression of these opsins and clock genes, in the photosensitive D. rerio ZEM-2S embryonic cells. Immunopositive labeling for Opn4m1 was detected in the cell membrane whereas Opn4m2 labeling shows nuclear localization, which did not change in response to light. opn4m1, opn4m2, gr, per1b, and cry1b presented an oscillatory profile of expression in LD condition. In both DD and LD condition, dexamethasone (DEX) treatment shifted the peak expression of per1b and cry1b transcripts to ZT16, which corresponds to the highest opn4m1 expression. Interestingly, DEX promoted an increase of per1b expression when applied in LD condition but a decrease when the cells were kept under DD condition. Although DEX effects are divergent with different light conditions, the response resulted in clock synchronization in all cases. Taken together, these data demonstrate that D. rerio ZEM-2S cells possess a photosensitive system due to melanopsin expression which results in an oscillatory profile of clock genes in response to LD cycle. Moreover, we provide evidence that glucocorticoid acts as a circadian regulator of D. rerio peripheral clocks.