Temporal relationships between FSH receptor, type 1 insulin-like growth factor receptor, and aromatase expression during FSH-induced differentiation of bovine granulosa cells maintained in serum-free culture.
A serum-free culture system has been developed in ruminants that allows gonadotrophin-responsive induction of oestradiol (E2) production by non-differentiated granulosa cells (GC) from small antral follicles. Critical determinants are dose of FSH and insulin-like growth factor (IGF), and the plating density of the GC. Over the first 16 h of culture when cells remained as a dispersed monolayer, expression declined in FSH receptors (FSHr) (P <0.001), IGF type 1 receptor (IGF-1r) (P <0.08) and p450 arom (CYP19, P <0.001). Characteristic GC clusters formed from 16 h and further enlarged between 24 and 48 h, accompanied by marked increases in FSHr (P <0.01), IGF-1r (P <0.05), and p450 arom (P <0.01) expression, and preceded induction and subsequent peak E2 production, at 96 and 144 h, respectively (P <0.01). In conclusion, isolation and dispersion of GC appears to induce reversion to an immature state resulting in loss of receptor expression. Re-establishment of cell-cell communications in the presence of FSH and IGF results in receptor up-regulation and induction of cellular differentiation.
Marsters
P
P
School of Human Development, University of Nottingham, Floor D East Block, Queen's Medical Centre, Nottingham NG7 2UH, UK. peter.masters@nottingham.ac.uk
Kendall
N R
NR
Campbell
B K
BK
D000818:Animals; D001141:Aromatase / Q000096:biosynthesis / Q000235:genetics*; D002417:Cattle; D002450:Cell Communication; D018929:Cell Culture Techniques / Q000379:methods; D002454:Cell Differentiation; D016895:Culture Media, Serum-Free; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000096:biosynthesis; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D005786:Gene Expression Regulation; D006107:Granulosa Cells / Q000166:cytology*; D011374:Progesterone / Q000096:biosynthesis; D012333:RNA, Messenger / Q000032:analysis; D017526:Receptor, IGF Type 1 / Q000096:biosynthesis / Q000235:genetics*; D011962:Receptors, FSH / Q000096:biosynthesis / Q000235:genetics*; D013002:Somatomedins / Q000494:pharmacology; D013997:Time Factors
D016895:Culture Media, Serum-Free; D012333:RNA, Messenger; D011962:Receptors, FSH; D013002:Somatomedins; D011374:Progesterone; D004958:Estradiol; D005640:Follicle Stimulating Hormone; D001141:Aromatase; D017526:Receptor, IGF Type 1