Cecconi S, Tatone C, Buccione R, Mangia F, Colonna R
Dipartimento di Scienze e Tecnologie Biomediche e di Biometria, Università dell'Aquila, Italy.
J Exp Zool. 1991 May;258(2):249-54. doi: 10.1002/jez.1402580216.
The role of granulosa cells in the regulation of mouse ovarian oocyte metabolism was investigated. Fully grown antral oocytes, isolated from surrounding cumulus cells, were cultured on monolayers of preantral granulosa cells in the presence of dbcAMP to prevent the resumption of meiosis. Under these conditions metabolic cooperativity was established between the two cell types as early as 1 hr after seeding. Moreover, cocultured oocytes phosphorylated two polypeptides of 74 and 21 kDa which are normally phosphorylated in follicle-enclosed growing oocytes but not in cumulus cell-enclosed fully grown oocytes at the germinal vesicle stage. When cocultured oocytes were allowed to resume meiosis, the 74 and 21 kDa proteins were synthesized but no longer phosphorylated even though intercellular coupling between the two cell types was maintained during radiolabeling. It appears therefore: a) that the different protein kinase activity of growing and fully grown germinal vesicle-stage mouse oocytes is related to the differentiative state of granulosa cells, and b) that the regulation of oocyte protein phosphorylation activity by granulosa cells is dependent on the meiotic stage of the oocyte.
研究了颗粒细胞在调节小鼠卵巢卵母细胞代谢中的作用。从周围卵丘细胞中分离出的完全成熟的腔前卵泡卵母细胞，在dbcAMP存在的情况下，培养于腔前颗粒细胞单层上，以防止减数分裂的恢复。在这些条件下，早在接种后1小时，两种细胞类型之间就建立了代谢协同作用。此外，共培养的卵母细胞使74 kDa和21 kDa的两种多肽磷酸化，这两种多肽在卵泡内生长的卵母细胞中通常会被磷酸化，但在卵丘细胞包裹的处于生发泡期的完全成熟卵母细胞中则不会。当共培养的卵母细胞恢复减数分裂时，尽管在放射性标记期间两种细胞类型之间的细胞间偶联得以维持，但74 kDa和21 kDa的蛋白质仍会合成，但不再被磷酸化。因此，似乎：a）生长中和完全成熟的生发泡期小鼠卵母细胞不同的蛋白激酶活性与颗粒细胞的分化状态有关；b）颗粒细胞对卵母细胞蛋白磷酸化活性的调节取决于卵母细胞的减数分裂阶段。
