title: Expression of gene, protein and immunohistochemical localization of the estrogen receptor isoform ERα1 in male rainbow trout lymphoid organs; indication of the role of estrogens in the regulation of immune mechanisms.
abstract: In vertebrates, estrogens act on the reproductive system but also affect the functioning of non-reproductive tissues such as the immune system. In teleost fish, effects of estrogens and xenoestrogens have been reported extensively, but the available information on targeted tissues and cells is still scarce. Moreover, a better knowledge of the distinct ER subtypes is required to find out the mechanistic pathways by which estrogen compounds are able to disrupt endogenous estrogen signaling in fish immunity. The present study aimed at characterizing, in male rainbow trout juveniles, multi-tissue gene expression pattern of one isoform of estrogen receptor (ER), ERα1, at the mRNA and protein levels. The mRNA levels for ERα1 were measured in various lymphoid organs by real-time RT-PCR and ERα1 protein level by Western blot. Furthermore, this protein was located by immunohistochemistry in the same organs. The transcripts were ubiquitously expressed, but at a higher level in testis and liver, while the protein was more abundant in testis and skin. Moreover, the ERα1 was detected in endothelial, Kupffer, mucous and chloride cells, hematopoietic tissues, proximal tubule, epithelia of the skin and intestine, in the lamina propria and in the stratum granulosum. This distribution backs the idea that, in male rainbow trout, estrogeno-mimetic compounds could be involved in different immune mechanisms such as inflammatory response, transport of Ig, mucus production, regulation of cellular immunity and development and maturation of lymphoid and myeloid cells.
authors.affiliation: Research Unit in Environmental and Evolutionary Biology (URBE), NARILIS, University of Namur, Rue de Bruxelles, 61, B-5000 Namur, Belgium.
authors.forename: Sophie
authors.initials: S
authors.lastname: Massart
authors.affiliation: Unit Research Animal and Functionality of Animal Products (URAFPA), University of Lorraine, F-54003 Nancy, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Milla
authors.affiliation: Research Unit in Environmental and Evolutionary Biology (URBE), NARILIS, University of Namur, Rue de Bruxelles, 61, B-5000 Namur, Belgium. Electronic address: patrick.kestemont@unamur.be.
authors.forename: Patrick
authors.initials: P
authors.lastname: Kestemont
mesh_terms: D000818:Animals; D047628:Estrogen Receptor alpha / Q000235:genetics* / Q000378:metabolism; D004967:Estrogens / Q000378:metabolism*; D007150:Immunohistochemistry; D008221:Lymphoid Tissue / Q000378:metabolism*; D008297:Male; D017686:Oncorhynchus mykiss / Q000276:immunology / Q000378:metabolism*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D047628:Estrogen Receptor alpha; D004967:Estrogens; D020033:Protein Isoforms; D012333:RNA, Messenger
keywords: Estrogen receptor; Gene expression pattern; Immunity; Immunohistochemistry; Rainbow trout