Profiles of 5α-Reduced Androgens in Humans and Eels: 5α-Dihydrotestosterone and 11-Ketodihydrotestosterone Are Active Androgens Produced in Eel Gonads

Abstract

Although 11-ketotestosterone (11KT) and testosterone (T) are major androgens in both teleosts and humans, their 5α-reduced derivatives produced by steroid 5α-reductase (SRD5A/srd5a), i.e., 11-ketodihydrotestosterone (11KDHT) and 5α-dihydrotestosterone (DHT), remains poorly characterized, especially in teleosts. In this study, we compared the presence and production of DHT and 11KDHT in Japanese eels and humans. Plasma 11KT concentrations were similar in both male and female eels, whereas T levels were much higher in females. In accordance with the levels of their precursors, 11KDHT levels did not show sexual dimorphism, whereas DHT levels were much higher in females. It is noteworthy that plasma DHT levels in female eels were higher than those in men. In addition, plasma 11KDHT was undetectable in both sexes in humans, despite the presence of 11KT. Three srd5a genes (srd5a1, srd5a2a and srd5a2b) were cloned from eel gonads. All three srd5a genes were expressed in the ovary, whereas only both srd5a2 genes were expressed in the testis. Human SRD5A1 was expressed in testis, ovary and adrenal, whereas SRD5A2 was expressed only in testis. Human SRD5A1, SRD5A2 and both eel srd5a2 isoforms catalyzed the conversion of T and 11KT into DHT and 11KDHT, respectively, whereas only eel srd5a1 converted T into DHT. DHT and 11KDHT activated eel androgen receptor (ar)α-mediated transactivation as similar fashion to T and 11KT. In contrast, human AR and eel arβ were activated by DHT and11KDHT more strongly than T and 11KT. These results indicate that in teleosts, DHT and 11KDHT may be important 5α-reduced androgens produced in the gonads. In contrast, DHT is the only major 5α-reduced androgens in healthy humans.

Cloning and Molecular Characterization of HSL and Its Expression Pattern in HPG Axis and Testis during Different Stages in Bactrian Camel

“…For example, under the action of STAR protein, cholesterol is transferred from mitochondria to the endometrium, further acting on the biosynthesis of steroid hormones in steroidogenic cells [ 29 ]. Testosterone is converted into 5–dihydrotestosterone by SRD5A in steroidogenic tissues and peripheral tissues [ 30 ], indicating that HSL participates in the regulation of steroid hormone synthesis and secretion by regulating the expression levels of STAR, HSD3B, IGF1and SRD5A1. HSL is also expressed in the adrenal gland, which is mainly involved in the regulation of cholesterol kinase activity.…”

The Distribution, Expression Patterns and Functional Analysis of NR1D1 and NR4A2 in the Reproductive Axis Tissues of the Male Tianzhu White Yak

“…For instance, StAR protein translocates cholesterol from the outer to the inner mitochondrial membrane and is used further for steroid hormone biosynthesis in steroidogenic cells [ 39 ]. Testosterone is converted into 5α-dihydrotestosterone by SRD5A in steroidogenic tissues and peripheral tissues [ 40 ]. The expression patterns, locations, potential functions and regulatory networks of NR1D1 and NR4A2 were elaborated in the present study, but the specific regulation of NR1D1 and NR4A2 in hormone metabolism requires further study.…”

Expression of Chrna9 is regulated by Tbx3 in undifferentiated pluripotent stem cells

“…ES cells and KUM9 cells were transfected using Lipofectamine 2000 (Thermo Fisher Scientific Inc., MA, USA) or Hily MAX (Dojindo Laboratories, Kumamoto, Japan). At 24 h or 48 h post-transfection, luciferase assays were performed as described 55 . Measurements were made using a MiniLumat LB9506 (Berthold Systems, Aliquippa, PA, USA) in a single tube, with the first assay involving the firefly luciferase, followed by the Renilla luciferase assay.…”