Steroid metabolism and profile of steroidogenic gene expression in Episkin: high similarity with human epidermis.
The skin is a well-recognized site of steroid formation and metabolism. Episkin is a cultured human epidermis. In this report, we investigate whether Episkin possesses a steroidogenic machinery able to metabolize adrenal steroid precursors into active steroids. Episkin was incubated with [14C]-dehydroepiandrosterone (DHEA) and 4-androstenedione (4-dione) and their metabolites were analyzed by liquid chromatography/mass spectrometry (LC/MS/MS). The results show that the major product of DHEA metabolism in Episkin is DHEA sulfate (DHEAS) (88% of the metabolites) while the other metabolites are 7alpha-OH-DHEA (8.2%), 4-dione (1.3%), 5-androstenediol (1.3%), dihydrotestosterone (DHT) (1.4%) and androsterone (ADT) (2.3%). When 4-dione is used as substrate, much higher levels of C19-steroids are produced with ADT representing 77% of the metabolites. These data indicate that 5alpha-reductase, 17beta-hydroxysteroid dehydrogenase (17beta-HSD) and 3alpha-hydroxysteroid dehdyrogenase (3alpha-HSD) activities are present at moderate levels in Episkin, while 3beta-HSD activity is low and represents a rate-limiting step in the conversion of DHEA into C19-steroids. Using realtime PCR, we have measured the level of mRNAs encoding the steroidogenic enzymes in Episkin. A good agreement is found between the mRNAs expression in Episkin and the metabolic profile. High expression levels of steroid sulfotransferase SULT2B1B and type 3 3alpha-HSD (AKR1C2) correspond to the high levels of DHEA sulfate (DHEAS) and ADT formed from DHEA and 4-dione, respectively. 3beta-HSD is almost undetectable while the other enzymes such as type 1 5alpha-reductase, types 2, 4, 5, 7, 8, and 10 17beta-HSD and 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD) (AKR1C1) are highly expressed. Except for UGT-glucuronosyl transferase, similar mRNA expression profiles between Episkin and human epidermis are observed.
Luu-The
Van
V
Laboratory of Molecular Endocrinology and Oncology, Laval University Hospital Research Center (CRCHUL) and Laval University, 2705 Laurier Boulevard, Quebec G1V 4G2, Canada. van.luu-the@crchul.ulaval.ca
Ferraris
Corinne
C
Duche
Daniel
D
Bélanger
Patrick
P
Leclaire
Jacques
J
Labrie
Fernand
F
D000735:Androstenedione / Q000378:metabolism*; D000738:Androsterone / Q000378:metabolism; D002250:Carbon Radioisotopes; D002478:Cells, Cultured; D002853:Chromatography, Liquid; D003687:Dehydroepiandrosterone / Q000378:metabolism*; D019314:Dehydroepiandrosterone Sulfate / Q000378:metabolism; D004798:Enzymes / Q000096:biosynthesis / Q000235:genetics; D004817:Epidermis / Q000201:enzymology*; D020869:Gene Expression Profiling; D006801:Humans; D012333:RNA, Messenger / Q000096:biosynthesis; D053719:Tandem Mass Spectrometry; D013739:Testosterone / Q000378:metabolism*; D046509:Tissue Culture Techniques
D002250:Carbon Radioisotopes; D004798:Enzymes; D012333:RNA, Messenger; D013739:Testosterone; D000735:Androstenedione; D003687:Dehydroepiandrosterone; D019314:Dehydroepiandrosterone Sulfate; D000738:Androsterone