title: Association of prolactin-induced protein with preputial development of hypospadias.
abstract: OBJECTIVE
  To investigate the molecular aetiology of hypospadias during a critical developmental period by identifying differentially regulated genes in the tissues of individuals with hypospadias and comparing these genes with similar genes in the tissues of control individuals.
  
  
  METHODS
  Pregnant Sprague-Dawley rats were administered flutamide (7.5 mg) on gestational days 15-17 to produce hypospadiac pups. Dams were killed on gestational day 17, and the genital tubercles (GTs) of male pups were harvested. Gene expression of RNA isolated from the GTs was analysed using an oligonucleotide microarray containing 20,500 genes. The results of microarray analysis were confirmed using quantitative real-time PCR (qPCR). Protein expression levels were studied using Western blot analysis. The distribution of genes associated with GT development in rats was histologically examined. Prepuces harvested from patients with hypospadias and phimosis were immunohistochemically examined for gene distribution.
  
  
  RESULTS
  Of the 20, 500 genes, 23 annotated genes, including prolactin-induced protein (Pip), in the GTs of the hypospadiac rats were expressed at levels less than half of that of similar genes in the GTs of the control rats. Findings from qPCR and Western blot analysis revealed significantly lower Pip/PIP expression in the GTs of the hypospadiac rats than in those of the control rats. Immunohistochemical analysis revealed PIP expression in the prepuces of the GTs of the control and hypospadiac rats. PIP was expressed in the human prepuces of the patients with hypospadias and phimosis.
  
  
  CONCLUSIONS
  Pip/PIP, expressed at low levels in the GTs of hypospadiac rats, may be associated with preputial development. This model can be useful to elucidate the molecular mechanisms underlying penile and urethral development as well as preputial development. Further studies should provide detailed information regarding the molecular aetiology of hypospadias.
authors: Department of Nephro-urology, Nagoya City University Graduate School of Medical Sciences, Mizuho-ku, Nagoya, Japan.
authors: Satoshi
authors: S
authors: Kurokawa
authors: Yoshiyuki
authors: Y
authors: Kojima
authors: Kentaro
authors: K
authors: Mizuno
authors: Hideyuki
authors: H
authors: Kamisawa
authors: Keiichi
authors: K
authors: Tozawa
authors: Kenjiro
authors: K
authors: Kohri
authors: Yutaro
authors: Y
authors: Hayashi
mesh_terms: D000726:Androgen Antagonists; D000818:Animals; D000831:Animals, Newborn; D015153:Blotting, Western; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004195:Disease Models, Animal; D005485:Flutamide; D015870:Gene Expression; D006023:Glycoproteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D007021:Hypospadias / Q000139:chemically induced / Q000235:genetics* / Q000378:metabolism; D008297:Male; D026901:Membrane Transport Proteins; D010688:Phimosis / Q000235:genetics* / Q000378:metabolism; D012313:RNA / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D000726:Androgen Antagonists; D002352:Carrier Proteins; D006023:Glycoproteins; D026901:Membrane Transport Proteins; C488892:PIP protein, human; C571670:Pip protein, rat; D012313:RNA; D005485:Flutamide