RUNX2 transcription factor regulates gene expression in luteinizing granulosa cells of rat ovaries.
The LH surge promotes terminal differentiation of follicular cells to become luteal cells. RUNX2 has been shown to play an important role in cell differentiation, but the regulation of Runx2 expression and its function in the ovary remain to be determined. The present study examined 1) the expression profile of Runx2 and its partner CBFbeta during the periovulatory period, 2) regulatory mechanisms of Runx2 expression, and 3) its potential function in the ovary. Runx2 expression was induced in periovulatory granulosa cells of human and rodent ovaries. RUNX2 and core binding factor-beta (CBFbeta) proteins in nuclear extracts and RUNX2 binding to a consensus binding sequence increased after human chorionic gonadotropin (hCG) administration. This in vivo up-regulation of Runx2 expression was recapitulated in vitro in preovulatory granulosa cells by stimulation with hCG. The hCG-induced Runx2 expression was reduced by antiprogestin (RU486) and EGF-receptor tyrosine kinase inhibitor (AG1478), indicating the involvement of EGF-signaling and progesterone-mediated pathways. We also found that in the C/EBPbeta knockout mouse ovary, Runx2 expression was reduced, indicating C/EBPbeta-mediated expression. Next, the function of RUNX2 was investigated by suppressing Runx2 expression by small interfering RNA in vitro. Runx2 knockdown resulted in reduced levels of mRNA for Rgc32, Ptgds, Fabp6, Mmp13, and Abcb1a genes. Chromatin immunoprecipitation analysis demonstrated the binding of RUNX2 in the promoter region of these genes, suggesting that these genes are direct downstream targets of RUNX2. Collectively, the present data indicate that the LH surge-induced RUNX2 is involved in various aspects of luteal function by directly regulating the expression of diverse luteal genes.
Park
Eun-Sil
ES
Department of Obstetrics and Gynecology, Chandler Medical Center, University of Kentucky, Lexington, Kentucky 40536-0298, USA.
Lind
Anna-Karin
AK
Dahm-Kähler
Pernilla
P
Brännström
Mats
M
Carletti
Martha Z
MZ
Christenson
Lane K
LK
Curry
Thomas E
TE
Jo
Misung
M
D018435:ATP Binding Cassette Transporter, Subfamily B / Q000235:genetics; D000818:Animals; D015153:Blotting, Western; D018797:Cell Cycle Proteins / Q000235:genetics; D002470:Cell Survival / Q000235:genetics / Q000502:physiology; D002478:Cells, Cultured; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D047369:Chromatin Immunoprecipitation; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics / Q000378:metabolism*; D050658:Core Binding Factor beta Subunit / Q000235:genetics / Q000378:metabolism; D050556:Fatty Acid-Binding Proteins / Q000235:genetics; D005260:Female; D005768:Gastrointestinal Hormones / Q000235:genetics; D015870:Gene Expression; D006107:Granulosa Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D047468:Immunoprecipitation; D053509:Matrix Metalloproteinase 13 / Q000235:genetics; D009124:Muscle Proteins / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D010053:Ovary / Q000166:cytology*; D011485:Protein Binding / Q000187:drug effects; D034741:RNA, Small Interfering; D051381:Rats; D017207:Rats, Sprague-Dawley
D018435:ATP Binding Cassette Transporter, Subfamily B; D018797:Cell Cycle Proteins; D006063:Chorionic Gonadotropin; D050659:Core Binding Factor Alpha 1 Subunit; D050658:Core Binding Factor beta Subunit; D050556:Fatty Acid-Binding Proteins; D005768:Gastrointestinal Hormones; D009124:Muscle Proteins; D009419:Nerve Tissue Proteins; D034741:RNA, Small Interfering; C486417:Rgcc protein, rat; C493717:Runx2 protein, rat; C057275:fatty acid-binding protein 6; C095122:multidrug resistance protein 3; D053509:Matrix Metalloproteinase 13; C507083:Mmp13 protein, rat