Protein kinase C inhibition of in vitro FSH-induced differentiation in pig granulosa cells.
In granulosa cells, growth factor IGF I plays a major role in both growth and differentiation, acting through an autocrine/paracrine mechanism, and its production is regulated by FSH, via cyclic AMP (cAMP). As protein kinase C is also involved in granulosa cell function, we investigated the possibility that its activation could balance the positive effects of FSH. Using pig granulosa cells cultured in vitro, we studied the effects of protein kinase C activation by tetradecanoylphorbol acetate (TPA) on IGF I mRNA level. We also checked morphological modifications, cAMP production and steroidogenesis at the P450 side chain cleavage mRNA and progesterone levels. Our data demonstrate that protein kinase C activation antagonizes the in vitro FSH-induced differentiation, particularly morphological modifications and accumulation of IGF I mRNA. These inhibitory effects on FSH responses suggest that there could be a balance between protein kinase A and protein kinase C pathways in regulating differentiation in pig granulosa cells.
Hatey
F
F
Laboratoire de Génétique Cellulaire, Centre de Recherches de Toulouse, Institut National de la Recherche Agronomique, Castanet-Tolosan, France.
Mulsant
P
P
Bonnet
A
A
Benne
F
F
Gasser
F
F
D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000096:biosynthesis / Q000235:genetics; D005260:Female; D005640:Follicle Stimulating Hormone / Q000037:antagonists & inhibitors*; D005786:Gene Expression Regulation / Q000187:drug effects; D006107:Granulosa Cells / Q000166:cytology / Q000187:drug effects*; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D011374:Progesterone / Q000096:biosynthesis / Q000235:genetics; D011493:Protein Kinase C / Q000494:pharmacology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D013552:Swine; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D012333:RNA, Messenger; D011374:Progesterone; D007334:Insulin-Like Growth Factor I; D005640:Follicle Stimulating Hormone; D002786:Cholesterol Side-Chain Cleavage Enzyme; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate