7:30 AM-10:00 AM
(81) EXPRESSION AND DISTRIBUTION OF AP-1 TRANSCRIPTION FACTORS IN PORCINE OVARIAN FOLLICLES AND CORPORA LUTEA .
Rusovici, Raluca1, LaVoie, Holly1, 1 Dept of Cell Biology and Neuroscience, Columbia, SC
ABSTRACT- The activator protein-1 (AP-1) transcription factors are important regulators of cell proliferation and differentiation. The distribution of different AP-1 family members in porcine ovary has not been investigated. To establish whether the expression of nuclear AP-1 factors varies with follicular status, we examined their expression in porcine ovarian follicles at different stages of development and corpora lutea. Western Blot analyses confirmed that JunD, c-Jun, c-Fos, and Fra-2 immunoreactive proteins were present in whole cell extracts of antral follicles (1-2, 3-4, 5-10 mm) and midluteal phase corpora lutea (CL). The intensities of c-Jun and c-Fos protein bands were decreased in CL compared to antral follicles. FosB isoforms were detected in antral follicles but not CL. Immunohistochemical (IHC) analyses of porcine ovary sections were performed to determine the distribution of these factors in: primordial, unilaminar and multilaminar primary follicles, small (1-2 mm), medium (3-4 mm), and large (5-10 mm) antral follicles, and CL. In primordial follicles, JunD was detected in 20-50% of granulosa cell (GC) nuclei and c-Jun in <10% of GC nuclei. In primary unilaminar follicles, GC nuclei stained for JunD (40%) and c-Jun (< 10%). GC nuclei of primary multilaminar follicles were immunopositive for JunD (60%), c-Jun (50-60%), c-Fos and Fra-2 (30-50%), and FosB (20%). Small and medium antral follicles exhibited GC nuclear staining for JunD (50-70%) and c-Jun (30-60%), c-Fos and Fra-2 (30-50%), and FosB (10-20%). Large antral follicles showed low levels of GC nuclear staining (10-20%) for all factors. Thecal cell nuclei of small and medium antral follicles expressed JunD and c-Jun (20-40%), c-Fos (30%), and Fra-2 (30-50%). Thecal cell nuclei of large antral follicles expressed lower levels (10-20%) of JunD, c-Jun, c-Fos, and Fra-2 compared to smaller antral follicles. Oocytes consistently stained for JunD but not other AP-1 factors. Large luteal cells (LLC) exhibited intense nuclear staining for JunD and Fra-2 (80-100% of nuclei). c-Fos and c-Jun were present in 50-70% of LLC nuclei. IHC with FosB antibodies yielded weak nuclear staining in CL. In summary, our data show that c-Jun and JunD predominate in developing follicles and that JunD and Fra2 predominate in CL. (supported by NIH HD38945)
KEY WORDS: ovary, Activator protein-1 (AP-1), corpus luteum, follicles