Role of CYP27A1 in progesterone metabolism in vitro and in vivo.
In the kidney, progesterone is inactivated to 20alpha-dihydro-progesterone (20alpha-DH-progesterone) to protect the mineralocorticoid receptor from progesterone excess. In an attempt to clone the enzyme with 20alpha-hydroxysteroid activity using expression cloning in CHOP cells and a human kidney expression library, serendipitously cDNA encoding CYP27A1 was isolated. Overexpression of CYP27A1 in CHOP cells decreased progesterone conversion to 20alpha-DH-progesterone in a dose-dependent manner, an effect enhanced by cotransfection with adrenodoxin and adrenodoxin reductase. Incubation of CHOP cells with 27-hydroxycholesterol, a product of CYP27A1, increased the ratio of progesterone to 20alpha-DH-progesterone in a concentration-dependent manner, indicating that the effect of CYP27A1 overexpression was mediated by 27-hydroxycholesterol. To analyze whether these observations are relevant in vivo, progesterone and 20alpha-DH-progesterone were measured by gas chromatography-mass spectometry in 24-h urine of CYP27A1 gene knockout (ko) mice and their control wild-type and heterozygote littermates. In CYP27A1 ko mice, urinary progesterone concentrations were decreased, 20alpha-DH-progesterone increased, and the progesterone-to-20alpha-DH-progesterone ratio decreased threefold (P < 0.001). Thus CYP27A1 modulates progesterone concentrations. The underlying mechanism is inhibition of 20alpha-hydroxysteroid dehydrogenase by 27-hydroxycholesterol.
Escher
Geneviève
G
Department of Nephrology, University Hospital of Berne, Berne, Switzerland. genevieve.escher@dkf.unibe.ch
Vögeli
Isabelle
I
Escher
Robert
R
Tuckey
Robert C
RC
Erickson
Sandra
S
Krozowski
Zygmunt
Z
Frey
Felix J
FJ
D000325:Adrenodoxin / Q000096:biosynthesis; D000818:Animals; D001711:Biotransformation; D015153:Blotting, Western; D002460:Cell Line; D053493:Cholestanetriol 26-Monooxygenase / Q000235:genetics* / Q000378:metabolism*; D003001:Cloning, Molecular; D004579:Electron Transport; D005260:Female; D005287:Ferredoxin-NADP Reductase / Q000096:biosynthesis; D008401:Gas Chromatography-Mass Spectrometry; D015723:Gene Library; D006801:Humans; D006888:Hydroxycholesterols / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D011374:Progesterone / Q000097:blood / Q000378:metabolism*; D014162:Transfection
D006888:Hydroxycholesterols; D000325:Adrenodoxin; D011374:Progesterone; C076996:27-hydroxycholesterol; C506831:CYP27A1 protein, human; D053493:Cholestanetriol 26-Monooxygenase; C506832:Cyp27a1 protein, mouse; D005287:Ferredoxin-NADP Reductase