Differential estrogenic 17beta-hydroxysteroid dehydrogenase activity and type 12 17beta-hydroxysteroid dehydrogenase expression levels in preadipocytes and differentiated adipocytes.
Estradiol (E2) is produced locally in adipose tissue and could play an important role in fat distribution and accumulation, especially in women. It is well recognized that aromatase is expressed in adipose tissue; however the identity of its estrogenic 17beta-hydroxysteroid dehydrogenase (17beta-HSD) partner is not identified. To gain a better knowledge about the enzyme responsible for the conversion of estrone into estradiol, we determined the activity and expression levels of known estrogenic 17beta-HSDs, namely types 1, 7 and 12 17beta-HSD in preadipocytes before and after differentiation into mature adipocytes using an adipogenic media. Estrogenic 17beta-HSD activity was assessed using [(14)C]-labelled estrone, while mRNA expression levels of types 1, 7 and 12 17beta-HSD were quantified using real-time PCR and protein expression levels of type 12 17beta-HSD was determined using immunoblot analysis. The data indicate that there is a low conversion of E1 into E2 in preadipocytes; however this activity is increased approximately 5-fold (p<0.0001) in differentiated adipocytes. The increased estrogenic 17beta-HSD activity is consistent with the increase in protein expression levels of 17beta-HSD12.
Molecular Endocrinology and Oncology Research Center, Laval University Medical Research Center and Laval University, Québec, Canada.
Véronique
V
Bellemare
Philippe
P
Laberge
Suzanne
S
Noël
André
A
Tchernof
Van
V
Luu-The
D015067:17-Hydroxysteroid Dehydrogenases / Q000235:genetics / Q000378:metabolism; D017667:Adipocytes / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D000328:Adult; D002454:Cell Differentiation; D002478:Cells, Cultured; D004958:Estradiol / Q000096:biosynthesis*; D004960:Estradiol Dehydrogenases / Q000235:genetics / Q000378:metabolism*; D004970:Estrone / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D007700:Kinetics; D008875:Middle Aged; D012333:RNA, Messenger / Q000032:analysis; D013234:Stem Cells / Q000166:cytology / Q000201:enzymology / Q000378:metabolism
D012333:RNA, Messenger; D004970:Estrone; D004958:Estradiol; D015067:17-Hydroxysteroid Dehydrogenases; C476565:17beta-hydroxysteroid dehydrogenase type 3; C044256:3 (or 17)-beta-hydroxysteroid dehydrogenase; D004960:Estradiol Dehydrogenases; C513331:HSD17B1 protein, human