| First Author | Ochsner SA | Year | 2003 |
| Journal | Endocrinology | Volume | 144 |
| Issue | 10 | Pages | 4376-84 |
| PubMed ID | 12959984 | Mgi Jnum | J:85773 |
| Mgi Id | MGI:2676541 | Doi | 10.1210/en.2003-0487 |
| Citation | Ochsner SA, et al. (2003) Disrupted function of tumor necrosis factor-alpha-stimulated gene 6 blocks cumulus cell-oocyte complex expansion. Endocrinology 144(10):4376-84 |
| abstractText | During ovulation, the oocyte and surrounding somatic cumulus cells contained within a specialized, mucoid matrix are released from the ovary. One matrix component, TNF-alpha-stimulated gene 6 (TSG-6), is a hyaluronan binding protein induced in cumulus cells of preovulatory follicles by the LH surge and is decreased in cumulus cells of COX-2 and prostaglandin E2 (PGE2) receptor subtype EP2 null mice that exhibit impaired ovulation and cumulus expansion. To determine if TSG-6 was hormonally induced in cumulus cells in vitro and was functional during the formation of the expanded matrix, we established a cumulus cell-oocyte complex (COC) culture system. This system was used to analyze the effects of FSH, PGE2, EP2 receptor, and selected protein kinase inhibitors on TSG-6 production as well as specific antibodies to the TSG-6 link module on TSG-6 function. We document that TSG-6 message and protein are induced by cAMP/protein kinase A/MAPK signaling pathways and that blocking these cascades prevents expansion and the production of TSG-6. FSH but not PGE2 rescued expansion and production of TSG-6 in the EP2 null COCs, indicating that generation of a cAMP signal is essential. Furthermore, disruption of the functional interactions between TSG-6, inter-alpha trypsin inhibitor, and hyaluronan with specific antibodies severely altered matrix formation and cumulus expansion, as recorded by time-lapse imaging. Collectively, these results indicate that TSG-6 mRNA is induced in cumulus cells in culture by cAMP and that the secreted TSG-6 protein is a key structural component of the mouse COC matrix. |
