title: Alteration of cell membrane proteoglycans impairs FSH receptor/Gs coupling and ERK activation through PP2A-dependent mechanisms in immature rat Sertoli cells.
abstract: BACKGROUND
  During the pre-pubertal life, the cessation of Sertoli cell proliferation and the onset of differentiation are associated with a shift in the FSH-mediated signaling leading to inhibition of the ERK-mitogenic pathway and to a concomitant sensitization of cAMP/PKA pathway.
  
  
  METHODS
  To highlight the role of cell proteoglycans (PGs) in the shift of FSH signaling, both FSH-induced cAMP production and ERK1/2 inactivation were studied in untreated and sodium chlorate PG-depleted cultured Sertoli cells from 20day-old rats.
  
  
  RESULTS
  Depletion of cell membrane PGs by sodium chlorate reduced FSH-, but not cholera toxin-stimulated cAMP production as well as basal ERK phosphorylation through an okadaic acid (OA)-sensitive mechanism. Involvement of PP2A was further substantiated by a marked decrease in membrane- associated PP2A activity under SC conditions and by the OA-induced restoration of PKA-dependent ERK inactivation in SC-treated cells.
  
  
  CONCLUSIONS
  In 20-day-old rat Sertoli cells, transmembrane cell PGs, through tethering/activation of PP2A activity exerts regulatory control on both FSH receptor/Gs coupling and ERK phosphorylation.
  
  
  CONCLUSIONS
  Besides their antiproliferative roles, cell PGs such as syndecan-1, could be involved in the increase in cAMP response to FSH occurring in Sertoli cells at the time of transition between proliferative and differentiated states.
authors.affiliation: Université de Caen Basse Normandie, Caen, France. jerome.levallet@unicaen.fr
authors.forename: Guénaëlle
authors.initials: G
authors.lastname: Levallet
authors.forename: Pierre-Jacques
authors.initials: PJ
authors.lastname: Bonnamy
authors.forename: Jérôme
authors.initials: J
authors.lastname: Levallet
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000502:physiology*; D008297:Male; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D054648:Protein Phosphatase 2 / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011962:Receptors, FSH / Q000819:agonists / Q000378:metabolism*; D015290:Second Messenger Systems / Q000502:physiology; D012708:Sertoli Cells / Q000378:metabolism*; D012756:Sheep; D053668:Syndecan-1 / Q000378:metabolism*
chemical_list: D011962:Receptors, FSH; C508243:Sdc1 protein, rat; D053668:Syndecan-1; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D048052:Mitogen-Activated Protein Kinase 3; D054648:Protein Phosphatase 2