Requirement for heparan sulphate proteoglycans to mediate basic fibroblast growth factor (FGF-2)-induced stimulation of Leydig cell steroidogenesis.
This study reports that, in contrast to previous findings, basic fibroblast growth factor (FGF-2) stimulates immature Leydig cell steroidogenesis in the absence of luteinizing hormone (LH). Heparan sulphate proteoglycans (HSPGs) are essential for this action of FGF-2 and the data suggest that HSPG/FGF-2 interactions have a significant role in the maintenance of immature Leydig cell steroidogenesis. Culture conditions were established for the maintenance of immature rat Leydig cells steroidogenesis in vitro for at least 2 days. Under these conditions the effect of exposure to FGF-2 at doses ranging from 0.1-10 ng/ml was shown to cause a significant stimulation of basal, but not LH-stimulated, 5 alpha-androstane 3 alpha,17 beta-diol production over 24h in culture. This stimulatory action on basal steroidogenesis is mediated through HSPG, as it was blocked by the addition of heparin (100 micrograms/ml), sodium chlorate (25mM) and protamine sulphate (5 micrograms/ml). These data demonstrate the involvement of HSPG in regulating FGF-2 action on Leydig cells and a potential role for Leydig cell HSPG in mediating paracrine regulatory actions of other heparin binding growth factors.
Laslett
A L
AL
Institute of Reproduction and Development, Monash University, Clayton, Victoria, Australia.
McFarlane
J R
JR
Hearn
M T
MT
Risbridger
G P
GP
D000818:Animals; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D005043:Etiocholanolone / Q000031:analogs & derivatives* / Q000032:analysis; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology*; D007985:Leydig Cells / Q000378:metabolism*; D008297:Male; D011509:Proteoglycans / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley
D011509:Proteoglycans; D016222:Fibroblast Growth Factor 2; C006576:androstane-3,17-dione; D005043:Etiocholanolone