title: 1alpha,25-Dihydroxyvitamin D3 affects hormone production and expression of steroidogenic enzymes in human adrenocortical NCI-H295R cells.
abstract: The current study presents data indicating that 1alpha,25-dihydroxyvitamin D(3) affects the production of hormones and expression of crucial steroidogenic enzymes in the human adrenocortical cell line NCI-H295R. This cell line is widely used as a model for adrenal steroidogenesis. Treatment of the cells with 1alpha,25-dihydroxyvitamin D(3) suppressed the levels of corticosterone, aldosterone, DHEA, DHEA-sulfate and androstenedione in the culture medium. In order to study the mechanisms behind this suppression of hormone production, we investigated the effects of 1alpha,25-dihydroxyvitamin D(3) on important genes and enzymes controlling the biosynthesis of adrenal hormones. The mRNA levels were decreased for CYP21A2 while they were increased for CYP11A1 and CYP17A1. No significant changes were observed in mRNA for CYP11B1, CYP11B2 or 3beta-hydroxysteroid dehydrogenase (3betaHSD). In similarity with the effects on mRNA levels, also the endogenous enzyme activity of CYP21A2 decreased after treatment with 1alpha,25-dihydroxyvitamin D(3). Interestingly, the two CYP17A1-mediated activities were influenced reciprocally - the 17alpha-hydroxylase activity increased whereas the 17,20-lyase activity decreased. The current data indicate that the 1alpha,25-dihydroxyvitamin D(3)-mediated decrease in corticosterone and androgen production is due to suppression of the 21-hydroxylase activity by CYP21A2 and the 17,20-lyase activity by CYP17A1, respectively. In conclusion, the current study reports novel findings on 1alpha,25-dihydroxyvitamin D(3)-mediated effects on hormone production and regulation of genes and enzymes involved in steroidogenesis in the adrenocortical NCI-H295R cell line, a model for human adrenal cortex.
authors.affiliation: Department of Pharmaceutical Biosciences, Division of Biochemistry, Box 578, University of Uppsala, SE-75123 Uppsala, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Lundqvist
authors.forename: Maria
authors.initials: M
authors.lastname: Norlin
authors.forename: Kjell
authors.initials: K
authors.lastname: Wikvall
mesh_terms: D015096:3-Hydroxysteroid Dehydrogenases / Q000235:genetics / Q000378:metabolism; D000302:Adrenal Cortex / Q000187:drug effects* / Q000378:metabolism*; D000450:Aldosterone / Q000378:metabolism; D000735:Androstenedione / Q000378:metabolism; D015153:Blotting, Western; D002117:Calcitriol / Q000494:pharmacology*; D002120:Calcium Channel Agonists / Q000494:pharmacology*; D002478:Cells, Cultured / Q000187:drug effects / Q000201:enzymology; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000235:genetics / Q000378:metabolism; D003345:Corticosterone / Q000378:metabolism; D019405:Cytochrome P-450 CYP11B2 / Q000235:genetics / Q000378:metabolism; D003687:Dehydroepiandrosterone / Q000378:metabolism; D019314:Dehydroepiandrosterone Sulfate / Q000378:metabolism; D006728:Hormones / Q000378:metabolism*; D006801:Humans; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013252:Steroid 11-beta-Hydroxylase / Q000235:genetics / Q000378:metabolism; D013254:Steroid 17-alpha-Hydroxylase / Q000235:genetics / Q000378:metabolism*; D013255:Steroid 21-Hydroxylase / Q000235:genetics / Q000378:metabolism*; D013256:Steroids / Q000378:metabolism
chemical_list: D002120:Calcium Channel Agonists; D006728:Hormones; D012333:RNA, Messenger; D013256:Steroids; D000735:Androstenedione; D003687:Dehydroepiandrosterone; D000450:Aldosterone; D019314:Dehydroepiandrosterone Sulfate; D015096:3-Hydroxysteroid Dehydrogenases; C531510:CYP21A2 protein, human; D013255:Steroid 21-Hydroxylase; C501892:CYP17A1 protein, human; D013254:Steroid 17-alpha-Hydroxylase; D019405:Cytochrome P-450 CYP11B2; D013252:Steroid 11-beta-Hydroxylase; D002786:Cholesterol Side-Chain Cleavage Enzyme; D002117:Calcitriol; D003345:Corticosterone