PTEN and Akt expression during growth of human ovarian follicles

Purpose To assess the expression of PTEN and total and phosphorylated Akt in human ovarian follicles during follicular growth. Methods Immunohistochemistry of ovarian tissues and Western blotting and immunofluorescence of primary cultured luteinized granulosa cells for PTEN and Akt. Results Immunoreactivity of Akt was found in the oocytes, granulosa cells and theca cells in primordial follicles, follicles at each growing stage and luteal cells. As the follicles grew, staining for PTEN became intense in the granulosa cells, whereas the intensity of phospho-Akt became weak. Western blotting and immunofluorescence analysis using primary cultured granulosa-lutein cells showed Akt and PTEN expression, and phosphorylation of Akt in vitro. Conclusions PTEN and Akt are present in the granulosa cells during folliculogenesis. An increase in PTEN may lead to changes in proliferation and/or differentiation of granulosa cells during follicular growth via regulation of Akt phosphorylation.