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.
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
Van
V
Luu-The
Corinne
C
Ferraris
Daniel
D
Duche
Patrick
P
Bélanger
Jacques
J
Leclaire
Fernand
F
Labrie
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