title: Norepinephrine activates P44 and P42 MAPK in human prostate stromal and smooth muscle cells but not in epithelial cells.
abstract: BACKGROUND
  In vascular smooth muscle cells, alpha1-adrenergic stimulation increases DNA synthesis and cell proliferation via activation of p44/42 (ERK1/2) MAPK. We examined whether norepinephrine (NE) activates MAPK and stimulates the proliferation of prostatic epithelial and non-epithelial cells.
  
  
  METHODS
  Human prostatic epithelial cells, stromal cells, and smooth muscle cells were purchased from BioWhittaker (Walkersville, MD). After reaching a semi-confluent condition, the cells were cultured in RPMI-1640 without serum for 1 day. At 10 min after adding NE (10(-6) or 10(-7) M) to the medium, the cells were collected. Cell lysate was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) followed by Western blot using anti-phospho-p44/42 and anti-p44/42 antibodies. The activation of p44/42 was estimated by the ratio of phospho-p44/42 to total p44/42. Cell proliferation was evaluated by (3)H-thymidine uptake assay. After reaching a semi-confluent condition, the cells were cultured in RPMI-1640 containing 0.5% FCS with or without NE (10(-6) or 10(-7) M) for 16 hr followed by a (3)H-thymidine uptake period (24 hr).
  
  
  RESULTS
  P44/42 MAPK was significantly activated by NE in non-epithelial cells (stromal cells and smooth muscle cells) while not in epithelial cells. The uptake of (3)H-thymidine was significantly increased by NE in both non-epithelial cells, which was inhibited by alpha1-adrenoceptor antagonists.
  
  
  CONCLUSIONS
  These results suggest that NE may stimulate the proliferation of non-epithelial prostatic cells, which may be involved in the pathogenesis of BPH.
authors.affiliation: Department of Urology, Osaka City University Medical School, Osaka, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Kanagawa
authors.forename: Kazunobu
authors.initials: K
authors.lastname: Sugimura
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Kuratsukuri
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Ikemoto
authors.forename: Taketoshi
authors.initials: T
authors.lastname: Kishimoto
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Nakatani
mesh_terms: D015153:Blotting, Western; D018929:Cell Culture Techniques; D002455:Cell Division / Q000502:physiology*; D004847:Epithelial Cells / Q000502:physiology; D006801:Humans; D008297:Male; D019950:Mitogen-Activated Protein Kinase 1 / Q000096:biosynthesis*; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000096:biosynthesis*; D032389:Myocytes, Smooth Muscle / Q000502:physiology; D009638:Norepinephrine / Q000494:pharmacology*; D011467:Prostate / Q000166:cytology* / Q000502:physiology*; D017154:Stromal Cells / Q000502:physiology; D013936:Thymidine
chemical_list: D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D013936:Thymidine; D009638:Norepinephrine