title: Regucalcin is broadly expressed in male reproductive tissues and is a new androgen-target gene in mammalian testis.
abstract: Regucalcin (RGN) is a calcium (Ca(2)(+))-binding protein which regulates intracellular Ca(2)(+) homeostasis by modulating the activity of enzymes regulating Ca(2)(+) concentration and enhancing Ca(2)(+)-pumping activity. Several studies have described the pivotal role of proper Ca(2)(+) homeostasis regulation to spermatogenesis and male fertility. Recently, RGN was identified as a sex steroid-regulated gene in prostate and breast; however, a possible role of RGN in spermatogenesis has not been examined. In this study, the expression and localization of RGN in rat and human testis, and other rat reproductive tissues was analyzed. Moreover, we studied whether RGN protein was present in seminiferous tubule fluid (STF). Finally, we examined the effect of 5α-dihydrotestosterone (DHT) on the expression of Rgn mRNA in rat seminiferous tubules (SeT) cultured ex vivo. The results presented in this study show that RGN is expressed in Leydig and Sertoli cells, as well as in all types of germ cells of both rat and human testis. RGN is also expressed in rat prostate, epididymis, and seminal vesicles. Moreover, RGN protein is present in rat STF. The results also demonstrate that Rgn expression is age dependent in rat testis, and is upregulated by the non-aromatizable androgen DHT in rat SeT cultured ex vivo. Taken together, these findings indicate that Rgn is a novel androgen-target gene in rat testis and that it may have a role in male reproductive function, particularly in the control of spermatogenesis.
authors.affiliation: CICS-UBI Health Sciences Research Center, University of Beira Interior, Avenida Infante D. Henrique, 6200-506 Covilhã, Portugal.
authors.forename: S S
authors.initials: SS
authors.lastname: Laurentino
authors.forename: S
authors.initials: S
authors.lastname: Correia
authors.forename: J E
authors.initials: JE
authors.lastname: Cavaco
authors.forename: P F
authors.initials: PF
authors.lastname: Oliveira
authors.forename: L
authors.initials: L
authors.lastname: Rato
authors.forename: M
authors.initials: M
authors.lastname: Sousa
authors.forename: A
authors.initials: A
authors.lastname: Barros
authors.forename: S
authors.initials: S
authors.lastname: Socorro
mesh_terms: D000728:Androgens / Q000494:pharmacology*; D000818:Animals; D002135:Calcium-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D002265:Carboxylic Ester Hydrolases; D002478:Cells, Cultured; D005786:Gene Expression Regulation / Q000187:drug effects; D005837:Genitalia, Male / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008322:Mammals / Q000235:genetics / Q000378:metabolism; D051381:Rats; D012708:Sertoli Cells / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D013091:Spermatogenesis / Q000235:genetics / Q000502:physiology; D013737:Testis / Q000187:drug effects / Q000378:metabolism*; D013739:Testosterone / Q000031:analogs & derivatives / Q000494:pharmacology; D014018:Tissue Distribution
chemical_list: D000728:Androgens; D002135:Calcium-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; C513323:RGN protein, human; D013739:Testosterone; C013915:boldenone; D002265:Carboxylic Ester Hydrolases; C513325:Rgn protein, rat