Korean J Fertil Steril.  2001 Jun;28(2):111-120.

Expression of OB-R, Regulation of Mitogen Activated Protein Kinase Activity and Maturation by Leptin in Mouse Oocytes

• Kang BM
• Han HJ
• Seo HY
• Hong SH
• Gye MC

Abstract

OBJECTIVE
To verify the expression of leptin receptor (OB-R) in oocytes and preimplantation embryos, the involvement of mitogen activated protein kinase (MAPK or Erk1/2) in the leptin signaling, and effect of leptin on the oocyte maturation in mice. METHOD: RT-PCR analysis of OB-R was conducted in germinal vesicle (GV)-intact and MII stage oocytes, and 1, 2, 8-cell embryos and blastocysts. Germinal vesicle breakdown (GVB), polar body extrusion, monitored in the presence or absence of leptin (1 microM). Following the leptin treatment, temporal changes in MAPK activity were verified by immunoprecipitation and in vitro kinase assay in MII oocytes.
RESULTS
The expression of OB-R mRNA was found in GV and MII oocyte but not in the embryos. MAPK activity of the MII oocytes was significantly increased by brief incubation in the HTF supplemented with leptin (1 microM). Priming of PD098059, a MEK inhibitor to leptin treatment attenuated the activation of MAPK by leptin in MII oocytes. Following 24 hrs of culture of the GV oocytes, leptin significant increased the GVB and 1st polar body extrusion.
CONCLUSION
This result suggested that functional interaction between leptin and OB-R resulted in potentiation of MAPK (Erk1/2) activity in MII oocytes through MEK activation and that leptin might be a local regulator of meiotic maturation of the mouse oocytes.

Keyword

Leptin; OB-R; MAPK; Oocytes; Mouse

MeSH Terms

Animals
Blastocyst
Embryonic Structures
Immunoprecipitation
Leptin*
Mice*
Oocytes*
Phosphotransferases
Polar Bodies
Protein Kinases*
Receptors, Leptin
RNA, Messenger
Leptin
Phosphotransferases
Protein Kinases
RNA, Messenger
Receptors, Leptin