Regulation of Bovine Tumor Necrosis Factor-α-Induced Protein 6 in Ovarian Follicles during the Ovulatory Process and Promoter Activation in Granulosa Cells
| Autor: | Jean Sirois, Nadine Bouchard, Khampoune Sayasith, Monique Doré |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Ovulation
Chromatin Immunoprecipitation endocrine system medicine.medical_specialty Granulosa cell Response element Electrophoretic Mobility Shift Assay Biology CREB Chorionic Gonadotropin Human chorionic gonadotropin Transactivation Endocrinology Ovarian Follicle Internal medicine medicine Animals Humans RNA Messenger Ovarian follicle Cyclic AMP Response Element-Binding Protein Promoter Regions Genetic Granulosa Cells Reverse Transcriptase Polymerase Chain Reaction Activator (genetics) Molecular biology Transcription Factor AP-1 AP-1 transcription factor medicine.anatomical_structure Mutagenesis Site-Directed biology.protein Cattle Female Cell Adhesion Molecules Proto-Oncogene Proteins c-fos |
| Zdroj: | Endocrinology. 149:6213-6225 |
| ISSN: | 1945-7170 0013-7227 |
| Popis: | To study the regulation of bovine TNFα-induced protein 6 (TNFAIP6) prior to ovulation, preovulatory follicles obtained after the treatment with human chorionic gonadotropin (hCG) were used. RT-PCR analyses showed that levels of TNFAIP6 mRNA were low before hCG but significantly increased after hCG treatment in follicles. Further analyses and immunohistochemistry indicated that this increase in transcript and protein levels occurred in theca and granulosa cells. To investigate molecular mechanisms involved in TNFAIP6 transactivation, the activity of bovine TNFAIP6 promoter was studied in granulosa cell cultures. Mutant studies identified the minimal region conferring full-length promoter activity, in which activator protein-1 (AP1) and cAMP response element (CRE) elements were required for promoter activity. Overexpression of dominant-negative AP1 and activating transcription factor/cAMP response element-binding protein (CREB) inhibited forskolin-inducible promoter activity. DNA binding assays demonstrated the importance of AP1 and CRE for activity and identified JunD, FosB, Fra2, CREB1, and CREB2 as being part of the AP1 complex, and FosB, Fra2, and CREB1 for the CRE complex. Chromatin immunoprecipitation assays confirmed binding of these proteins with endogenous TNFAIP6 promoter. Treatment with forskolin, prostaglandin E2, and catalytic subunit protein kinase (cPKA) stimulated, but H89, PKA inhibitor peptide, and indomethacin inhibited, TNFAIP6 promoter activity and gene expression in granulosa cells. Collectively, this study is the first to describe that the ovulatory process in cows is associated with a gonadotropin-dependent induction of TNFAIP6 in ovarian follicles and provide the molecular basis through which AP1 and CRE sites and PKA activation played important roles in the regulation of TNFAIP6 in granulosa cells. |
| Databáze: | OpenAIRE |
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