Distribution and Y397 phosphorylation of focal adhesion kinase on follicular development in the mouse ovary

• Published in: Cell and tissue research Vol. 347; no. 2; pp. 457 - 465
• Main Authors: Sakurai, Masahiro, Ohtake, Jun, Ishikawa, Takayuki, Tanemura, Kentaro, Hoshino, Yumi, Arima, Takahiro, Sato, Eimei
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.02.2012; Springer; Springer Nature B.V
• Subjects: abnormal development; adhesion; Analysis; Animals; Apoptosis; Biomedical and Life Sciences; Biomedicine; caspase-3; cell adhesion; Cell adhesion & migration; correlation; Female; Focal Adhesion Kinase 1 - metabolism; follicular atresia; Follicular Atresia - metabolism; Gonadotropins, Equine - administration & dosage; Gonadotropins, Equine - metabolism; granulosa cells; Granulosa Cells - enzymology; Granulosa Cells - metabolism; Human Genetics; Immunohistochemistry; Mice; Molecular Medicine; Ovarian cancer; Ovarian Follicle - enzymology; Ovarian Follicle - growth & development; Ovarian Follicle - metabolism; Phosphorylation; Phosphotransferases; Pregnancy; pregnant mare serum gonadotropin; protein-tyrosine kinases; Proteomics; Regular Article; Rodents; signal transduction; Western blotting; Granulosa cells; Phosphorylation; Focal adhesion kinase; Ovarian follicular development; Apoptosis
• ISSN: 0302-766X; 1432-0878
• DOI: 10.1007/s00441-011-1307-2

Several protein tyrosine kinases (PTKs) are identified as follicle survival factors that suppress apoptosis in granulosa cells. Focal adhesion kinase (FAK/PTK2) interacts with numerous signaling partners and is important for cell adhesion, survival and other vital processes in which FAK autophosphorylation at Y397 (pY397 FAK) is critical for activating signaling pathways. Despite its important roles in apoptosis, the expression and function of FAK in the ovaries remain unknown. Here, we describe FAK expression, including pY397 FAK, in normal healthy mouse ovaries and its association with follicular development and/or atresia. Normal healthy mouse ovaries were used for western blot (n > 60) and immunohistochemical (n > 180) analyses. Western blot results in immature and mature mice revealed that total FAK and pY397 FAK were highly expressed in the ovary and immunohistochemistry results in 3-week-old mice showed they were localized to granulosa cells of ovarian follicles, especially preantral follicles. In 3-week-old mice treated with 5 IU pregnant mare serum gonadotropin (for obtaining homogenous populations of growing or atretic follicles), western blotting revealed that follicular atresia progression involved decreased phosphorylation of Y397 at 72 and 96 h after treatment, particularly in granulosa cells of atretic follicles, as shown by immunohistochemistry results at 72 h after treatment. Moreover, immunostaining patterns of FAK and cleaved caspase-3 were negatively correlated in serial sections of 3-week-old mouse ovaries. These results suggest that FAK is most active in ovarian follicle granulosa cells and that its phosphorylation at Y397 is histologically meaningful in follicular development in normal healthy ovaries.