BMP-2 and -6 modulate porcine theca cell function alone and co-cultured with granulosa cells

• Published in: Domestic animal endocrinology 2005-11, Vol.29 (4), p.593-604
• Main Authors: Brankin, Victoria, Quinn, Ruth L., Webb, Robert, Hunter, Morag G.
• Format: Article
• Language: English
• Subjects: androstenedione; Androstenedione - biosynthesis; animal proteins; Animals; BMP; Bone Morphogenetic Protein 2; Bone Morphogenetic Protein 6; Bone Morphogenetic Proteins - pharmacology; Cell Communication - drug effects; Cell Communication - physiology; cell proliferation; Cell Survival - drug effects; Cell Survival - physiology; Coculture Techniques; cyclic AMP; Cyclic AMP - metabolism; estradiol; Estradiol - biosynthesis; Female; Follicle; granulosa cells; Granulosa Cells - cytology; Granulosa Cells - metabolism; growth factors; Humans; Ovarian Follicle - cytology; Ovarian Follicle - drug effects; Ovarian Follicle - metabolism; Ovary; physiological regulation; Pig; Progesterone; Progesterone - biosynthesis; Recombinant Proteins - pharmacology; steroidogenesis; Swine; Theca Cells - cytology; Theca Cells - drug effects; Theca Cells - metabolism; thecal cells; Transforming Growth Factor beta - pharmacology
• ISSN: 0739-7240; 1879-0054
• DOI: 10.1016/j.domaniend.2005.04.001

Bone morphogenetic proteins (BMPs) are emerging as a family of proteins crucial in the regulation of fertility and ovulation rate. We have shown that porcine theca cells express BMP receptors, however, there is a paucity of information regarding the effect(s) of BMPs on theca cell function. The purpose of this study was to investigate the effects of BMP-2 and -6 on theca cells cultured under serum-free conditions in terms of steroidogenesis, cAMP release and proliferation. The study was further extended to determine whether BMP responses in theca cells are affected by the addition of granulosa cells to the culture system. Both BMPs suppressed progesterone and androstenedione synthesis by theca cells ( P < 0.05) after 144 h in culture. Oestradiol synthesis was suppressed ( P < 0.05) by BMP-2, but not BMP-6, and theca cell proliferation was stimulated ( P < 0.05) by BMP-6, but not BMP-2, after 144 h in culture. Both BMP-2 and -6 inhibited cAMP release ( P < 0.05) by theca cells. Furthermore, progesterone and androstenedione synthesis by co-cultured theca and granulosa cells were suppressed ( P < 0.05) whereas cell proliferation was stimulated ( P < 0.05). These results provide strong evidence for a functional BMP system in the porcine ovary and that theca cells are responsive to BMPs in terms of steroidogenesis and proliferation. BMP-2 and -6 may have a role as luteinisation inhibitors in this polyovular species.