title: Bid and Bax are involved in granulosa cell apoptosis during follicular atresia in porcine ovaries.
abstract: More than 99% of follicles undergo "atresia" during follicular development and growth. Follicular atresia is predominantly regulated by granulosa cell apoptosis. However, the intracellular signaling pathway of apoptosis in granulosa cells has not been revealed. In the present study, we examined changes in the expression of BH3-interacting domain death agonist (Bid) and Bcl-2-associated X protein (Bax), which are considered to promote the cell death ligand/receptor-mediated process in mitochondrion-dependent type II apoptosis, in porcine granulosa cells during atresia. Levels of mRNA and protein of Bid and Bax were determined by the reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting techniques, respectively. Levels of Bid and Bax mRNA and protein were markedly increased in granulosa cells of early atretic follicles compared with those of healthy follicles. In situ hybridization and immunohistochemical staining revealed that mRNA and protein of Bid and Bax were present in the granulosa cells, though only traces were found in healthy follicles; however, strong staining was noted in atretic follicles. These results indicate that Bid and Bax appear to be signal transduction factors in granulosa cells during follicular atresia and appear to play proapoptotic roles and confirm that the porcine granulosa cell is a mitochondrion-dependent type II apoptotic cell.
authors: Animal Resource Science Center, The University of Tokyo, Kasama, Japan.
authors: Takafumi
authors: T
authors: Sai
authors: Yasufumi
authors: Y
authors: Goto
authors: Ryousuke
authors: R
authors: Yoshioka
authors: Akihisa
authors: A
authors: Maeda
authors: Fuko
authors: F
authors: Matsuda
authors: Miki
authors: M
authors: Sugimoto
authors: Kannika
authors: K
authors: Wongpanit
authors: Hua-Zi
authors: HZ
authors: Jin
authors: Jun-You
authors: JY
authors: Li
authors: Noboru
authors: N
authors: Manabe
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D051023:BH3 Interacting Domain Death Agonist Protein / Q000378:metabolism*; D005260:Female; D005496:Follicular Atresia / Q000378:metabolism*; D006107:Granulosa Cells / Q000378:metabolism*; D010053:Ovary / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D013552:Swine / Q000378:metabolism*; D051028:bcl-2-Associated X Protein / Q000378:metabolism*
chemical_list: D051023:BH3 Interacting Domain Death Agonist Protein; D051028:bcl-2-Associated X Protein