title: Testicular synthesis and vitamin D action.
abstract: BACKGROUND
  The vitamin D system has pleiotropic effects not only in bone metabolism. Its role in testicular steroidogenesis is new and deserves intensive research.
  
  
  OBJECTIVE
  We hypothesize that vitamin D, especially 1,25 dihydroxyvitamin D3 [1,25(OH)2D3 (calcitriol)] induces male steroidogenesis and intend to identify its impact on genes and pathways in testicular androgen regulation.
  
  
  METHODS
  Human adult primary testicular cells were isolated, treated with 1,25(OH)2D3, and their gene expression levels profiled by microarray analysis. Highly regulated genes were confirmed by real-time quantitative PCR. In addition, the effects of 1,25(OH)2D3 in combination with LH and IGF-I on the gene expression level of androgens were assessed. T levels in the culture media were determined by a high-resolution ELISA. The expression of vitamin D receptor was confirmed at baseline and after 1,25(OH)2D3 stimulation using immunocytochemistry.
  
  
  RESULTS
  Microarrays depicted 63 genes significantly regulated by 1,25(OH)2D3, including genes related to male androgen and vitamin D metabolism, mainly triggered by the vitamin D receptor/retinoid X receptor activation. 1,25(OH)2D3 led to significant changes in the expression profiles of reproductive genes and significantly increased T synthesis in human testicular cell cultures.
  
  
  CONCLUSIONS
  Data from our human primary testicular cell culture model suggest that vitamin D plays a major role in male steroidogenesis in vitro.
authors.affiliation: Department of Internal Medicine, Division of Endocrinology and Metabolism (D.H., J.M., V.S., M.U., T.R.P., B.O.-P.), Department of Urology (K.H., R.Z.), and Department of Surgery, Division of Transplantation Surgery (P.S., H.M.), Medical University of Graz, 8036 Graz, Austria.
authors.forename: D
authors.initials: D
authors.lastname: Hofer
authors.forename: J
authors.initials: J
authors.lastname: Münzker
authors.forename: V
authors.initials: V
authors.lastname: Schwetz
authors.forename: M
authors.initials: M
authors.lastname: Ulbing
authors.forename: K
authors.initials: K
authors.lastname: Hutz
authors.forename: Ph
authors.initials: P
authors.lastname: Stiegler
authors.forename: R
authors.initials: R
authors.lastname: Zigeuner
authors.forename: T R
authors.initials: TR
authors.lastname: Pieber
authors.forename: H
authors.initials: H
authors.lastname: Müller
authors.forename: B
authors.initials: B
authors.lastname: Obermayer-Pietsch
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000728:Androgens / Q000235:genetics / Q000378:metabolism*; D002117:Calcitriol / Q000494:pharmacology*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D007986:Luteinizing Hormone / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D061251:Primary Cell Culture; D018167:Receptors, Calcitriol / Q000235:genetics / Q000378:metabolism; D013737:Testis / Q000166:cytology* / Q000502:physiology; D013739:Testosterone / Q000096:biosynthesis* / Q000235:genetics; D059467:Transcriptome / Q000187:drug effects*; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology; D014815:Vitamins / Q000494:pharmacology
chemical_list: D000728:Androgens; D018167:Receptors, Calcitriol; D014815:Vitamins; D013739:Testosterone; D007334:Insulin-Like Growth Factor I; D007986:Luteinizing Hormone; D002117:Calcitriol