title: Mamld1 knockdown reduces testosterone production and Cyp17a1 expression in mouse Leydig tumor cells.
abstract: BACKGROUND
  MAMLD1 is known to be a causative gene for hypospadias. Although previous studies have indicated that MAMLD1 mutations result in hypospadias primarily because of compromised testosterone production around the critical period for fetal sex development, the underlying mechanism(s) remains to be clarified. Furthermore, although functional studies have indicated a transactivation function of MAMLD1 for the non-canonical Notch target Hes3, its relevance to testosterone production remains unknown. To examine these matters, we performed Mamld1 knockdown experiments.
  
  
  RESULTS
  Mamld1 knockdown was performed with two siRNAs, using mouse Leydig tumor cells (MLTCs). Mamld1 knockdown did not influence the concentrations of pregnenolone and progesterone but significantly reduced those of 17-OH pregnenolone, 17-OH progesterone, dehydroepiandrosterone, androstenedione, and testosterone in the culture media. Furthermore, Mamld1 knockdown significantly decreased Cyp17a1 expression, but did not affect expressions of other genes involved in testosterone biosynthesis as well as in insulin-like 3 production. Hes3 expression was not significantly altered. In addition, while 47 genes were significantly up-regulated (fold change >2.0×) and 38 genes were significantly down-regulated (fold change <0.5×), none of them was known to be involved in testosterone production. Cell proliferation analysis revealed no evidence for compromised proliferation of siRNA-transfected MLTCs.
  
  
  CONCLUSIONS
  The results, in conjunction with the previous data, imply that Mamld1 enhances Cyp17a1 expression primarily in Leydig cells and permit to produce a sufficient amount of testosterone for male sex development, independently of the Hes3-related non-canonical Notch signaling.
authors.affiliation: Department of Molecular Endocrinology, National Research Institute for Child Health and Development, Tokyo, Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Nakamura
authors.forename: Maki
authors.initials: M
authors.lastname: Fukami
authors.forename: Fumihiro
authors.initials: F
authors.lastname: Sugawa
authors.forename: Mami
authors.initials: M
authors.lastname: Miyado
authors.forename: Katsuya
authors.initials: K
authors.lastname: Nonomura
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Ogata
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D015536:Down-Regulation; D020869:Gene Expression Profiling; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D007984:Leydig Cell Tumor / Q000201:enzymology*; D008297:Male; D051379:Mice; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics*; D034741:RNA, Small Interfering / Q000378:metabolism; D051880:Receptors, Notch / Q000378:metabolism; D015398:Signal Transduction; D013254:Steroid 17-alpha-Hydroxylase / Q000096:biosynthesis*; D013256:Steroids / Q000378:metabolism; D013739:Testosterone / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics*; D014162:Transfection
chemical_list: C486455:Maml1 protein, mouse; D009687:Nuclear Proteins; D034741:RNA, Small Interfering; D051880:Receptors, Notch; D013256:Steroids; D014157:Transcription Factors; D013739:Testosterone; D013254:Steroid 17-alpha-Hydroxylase