title: [TGF-beta1 reduces connexin43-mediated gap junctional intercellular communication in rat Leydig cells].
abstract: OBJECTIVE
  To observe the effects of TGF-beta on the expression of connexin43 (Cx43) and Cx43-mediated gap junctional intercellular communication (GJIC) in rat Leydig cells, and investigate the association of its effects on Leydig cells with its ability of changing GJIC.
  
  
  METHODS
  Primarily cultured purified Leydig cells were divided into a blank control group, a positive control group (treated with the GJIC inhibitor Carbenoxolone), and four TGF-beta1 groups (treated with TGF-beta1 at the concentration of 1, 2, 5 and 10 ng/ml, respectively, for 20 hours). The localization and expression of Cx43 were detected by immunofluorescence and Western blot, and the changes in GJIC analyzed by FRAP assay.
  
  
  RESULTS
  Cx43 was expressed as scattered bright spots in the cytoplasm and membrane of Leydig cells. TGF-beta1 significantly elevated the expression of Cx43 in the cytoplasm, but caused no evident change in the membrane. Western blot showed an evident increase in the phosphorylation of Cx43 with the increased concentration of TGF-beta1 as compared with that of the blank control group (P < 0.05). After 20 hours of treatment with TGF-beta1 at 5 ng/ml, the fluorescence intensity of Leydig cells was markedly reduced (P < 0.01), with a mean fluorescence recovery rate of merely (43.58 +/- 1.87)%.
  
  
  CONCLUSIONS
  TGF-beta1 could significantly down-regulate GJIC between adjacent Leydig cells, and this inhibitory effect may be achieved by promoting the expression of Cx43 in the cytoplasm and elevating the phosphorylation of Cx43.
authors.affiliation: Department of Traditional Chinese Medicine/PLA Center of Traditional Chinese Medicine, The Fourth Military Medical University, Xi'an, Shaanxi 710032, China.
authors.forename: Man-Li
authors.initials: ML
authors.lastname: Liu
authors.forename: Zhi-Hong
authors.initials: ZH
authors.lastname: Zhang
authors.forename: Zong-Ren
authors.initials: ZR
authors.lastname: Wang
authors.forename: Jing
authors.initials: J
authors.lastname: Ma
mesh_terms: D000818:Animals; D002450:Cell Communication / Q000187:drug effects*; D002478:Cells, Cultured; D018031:Connexin 43 / Q000378:metabolism*; D017629:Gap Junctions / Q000187:drug effects / Q000378:metabolism*; D007985:Leydig Cells / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D010766:Phosphorylation; D051381:Rats; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology*
chemical_list: D018031:Connexin 43; D053773:Transforming Growth Factor beta1