T. Matsuoka et al., Tyrosine phosphorylation of STAT3 by leptin through leptin receptor in mouse metaphase 2 stage oocyte, BIOC BIOP R, 256(3), 1999, pp. 480-484
Citations number
23
Categorie Soggetti
Biochemistry & Biophysics
Journal title
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
Leptin is the product of the obese gene (ob), and is secreted in plasma fro
m mature adipocytes. It has been recently reported that leptin is synthesiz
ed in granulosa and cumulus cells within the follicle of the ovary, and is
present in mature human oocytes, suggesting possible roles of leptin in sev
eral aspects of pre- and post-ovulatory follicular development. On the othe
r hand, TAT (Signal Transducer and Activator of Transcription) transcriptio
n factors are involved in leptin-associated signal transduction. In this re
port, we studied the expression of leptin receptor and STAT3 activation by
leptin in metaphase 2 stage (M2) oocytes. Reverse transcriptase-polymerase
chain reaction (RT-PCR) and immunoblotting showed that mRNA and protein of
leptin receptor were expressed in M2 stage oocyte. Leptin at 15 ng/ml, the
concentration observed in follicular fluid, caused tyrosine phosphorylation
of STAT3 in mouse M2 stage oocytes. These results suggest possible roles o
f leptin in several aspects during oocyte maturation by activating the STAT
signal transduction pathway. (C) 1999 Academic Press.