Next Article in Journal
Application of CRISPR-Cas9 Based Genome-Wide Screening Approaches to Study Cellular Signalling Mechanisms
Next Article in Special Issue
Mixture Concentration-Response Modeling Reveals Antagonistic Effects of Estradiol and Genistein in Combination on Brain Aromatase Gene (cyp19a1b) in Zebrafish
Previous Article in Journal
Mutagenesis Study of the Cytochrome c Subunit Responsible for the Direct Electron Transfer-Type Catalytic Activity of FAD-Dependent Glucose Dehydrogenase
Previous Article in Special Issue
Estrogen, Angiogenesis, Immunity and Cell Metabolism: Solving the Puzzle
Article Menu
Issue 4 (April) cover image

Export Article

Open AccessArticle
Int. J. Mol. Sci. 2018, 19(4), 932; https://doi.org/10.3390/ijms19040932

Immune-Specific Expression and Estrogenic Regulation of the Four Estrogen Receptor Isoforms in Female Rainbow Trout (Oncorhynchus mykiss)

1
Centre for Fish and Wildlife Health, 3012 Bern, Switzerland
2
Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Länggassstrasse 122, 3012 Bern, Switzerland
*
Author to whom correspondence should be addressed.
Received: 2 February 2018 / Revised: 1 March 2018 / Accepted: 7 March 2018 / Published: 21 March 2018
(This article belongs to the Special Issue Molecular Pathways of Estrogen Receptor Action)
Full-Text   |   PDF [2277 KB, uploaded 3 May 2018]   |  

Abstract

Genomic actions of estrogens in vertebrates are exerted via two intracellular estrogen receptor (ER) subtypes, ERα and ERβ, which show cell- and tissue-specific expression profiles. Mammalian immune cells express ERs and are responsive to estrogens. More recently, evidence became available that ERs are also present in the immune organs and cells of teleost fish, suggesting that the immunomodulatory function of estrogens has been conserved throughout vertebrate evolution. For a better understanding of the sensitivity and the responsiveness of the fish immune system to estrogens, more insight is needed on the abundance of ERs in the fish immune system, the cellular ratios of the ER subtypes, and their autoregulation by estrogens. Consequently, the aims of the present study were (i) to determine the absolute mRNA copy numbers of the four ER isoforms in the immune organs and cells of rainbow trout, Oncorhynchus mykiss, and to compare them to the hepatic ER numbers; (ii) to analyse the ER mRNA isoform ratios in the immune system; and, (iii) finally, to examine the alterations of immune ER mRNA expression levels in sexually immature trout exposed to 17β-estradiol (E2), as well as the alterations of immune ER mRNA expression levels in sexually mature trout during the reproductive cycle. All four ER isoforms were present in immune organs—head kidney, spleen-and immune cells from head kidney and blood of rainbow trout, but their mRNA levels were substantially lower than in the liver. The ER isoform ratios were tissue- and cell-specific, both within the immune system, but also between the immune system and the liver. Short-term administration of E2 to juvenile female trout altered the ER mRNA levels in the liver, but the ERs of the immune organs and cells were not responsive. Changes of ER gene transcript numbers in immune organs and cells occurred during the reproductive cycle of mature female trout, but the changes in the immune ER profiles differed from those in the liver and gonads. The correlation between ER gene transcript numbers and serum E2 concentrations was only moderate to low. In conclusion, the low mRNA numbers of nuclear ER in the trout immune system, together with their limited estrogen-responsiveness, suggest that the known estrogen actions on trout immunity may be not primarily mediated through genomic actions, but may involve other mechanisms, such as non-genomic pathways or indirect effects. View Full-Text
Keywords: estrogen receptor; isoforms; rainbow trout; immune system; reproductive cycle estrogen receptor; isoforms; rainbow trout; immune system; reproductive cycle
Figures

Graphical abstract

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 (CC BY 4.0).
SciFeed
Printed Edition Available!
A printed edition of this Special Issue is available here.

Share & Cite This Article

MDPI and ACS Style

Casanova-Nakayama, A.; Wernicke von Siebenthal, E.; Kropf, C.; Oldenberg, E.; Segner, H. Immune-Specific Expression and Estrogenic Regulation of the Four Estrogen Receptor Isoforms in Female Rainbow Trout (Oncorhynchus mykiss). Int. J. Mol. Sci. 2018, 19, 932.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Int. J. Mol. Sci. EISSN 1422-0067 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top