Activation of PKA, p38 MAPK and ERK1/2 by gonadotropins in cumulus cells is critical for induction of EGF-like factor and TACE/ADAM17 gene expression during <it>in vitro </it>maturation of porcine COCs

• Main Authors: Yamashita Yasuhisa (Author), Hishinuma Mitsugu (Author), Shimada Masayuki (Author)
• Format: Book
• Published: BMC, 2009-12-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

<p>Abstract</p> <p>Objectives</p> <p>During ovulation, it has been shown that LH stimulus induces the expression of numerous genes via PKA, p38 MAPK, PI3K and ERK1/2 in cumulus cells and granulosa cells. Our recent study showed that EGF-like factor and its protease (TACE/ADAM17) are required for the activation of EGF receptor (EGFR), cumulus expansion and oocyte maturation of porcine cumulus-oocyte complexes (COCs). In the present study, we investigated which signaling pathways are involved in the gene expression of EGF-like factor and in <it>Tace/Adam17 </it>expression in cumulus cells of porcine COC during <it>in vitro </it>maturation.</p> <p>Methods</p> <p><it>Areg</it>, <it>Ereg</it>, <it>Tace/Adam17</it>, <it>Has2</it>, <it>Tnfaip6 </it>and <it>Ptgs2 </it>mRNA expressions were detected in cumulus cells of porcine COCs by RT-PCR. Protein level of ERK1/2 phosphorylation in cultured cumulus cells was analyzed by westernblotting. COCs were visualized using a phase-contrast microscope.</p> <p>Results</p> <p>When COCs were cultured with FSH and LH up to 2.5 h, <it>Areg</it>, <it>Ereg </it>and <it>Tace/Adam17 </it>mRNA were expressed in cumulus cells of COCs. <it>Areg</it>, <it>Ereg </it>and <it>Tace/Adam17 </it>gene expressions were not suppressed by PI3K inhibitor (LY294002), whereas PKA inhibitor (H89), p38 MAPK inhibitor (SB203580) and MEK inhibitor (U0126) significantly suppressed these gene expressions. Phosphorylation of ERK1/2, and the gene expression of <it>Has2</it>, <it>Tnfaip6 </it>and <it>Ptgs2 </it>were also suppressed by H89, SB203580 and U0126, however, these negative effects were overcome by the addition of EGF to the medium, but not in the U0126 treatment group.</p> <p>Conclusion</p> <p>The results showed that PKA, p38 MAPK and ERK1/2 positively controlled the expression of EGF-like factor and TACE/ADMA17, the latter of which impacts the cumulus expansion and oocyte maturation of porcine COCs via the EGFR-ERK1/2 pathway in cumulus cells.</p>

Item Description

10.1186/1757-2215-2-20
1757-2215