Kim Jin Yeong
Department of Obstetrics and Gynecology, Cheil General Hospital, Kwandong University College of Medicine, Seoul, Korea.
Clin Exp Reprod Med. 2012 Mar;39(1):10-4. doi: 10.5653/cerm.2012.39.1.10. Epub 2012 Mar 31.
The ovarian follicles develop initially from primordial follicles. The majority of ovarian primordial follicles are maintained quiescently as a reserve for the reproductive life span. Only a few of them are activated and develop to an advanced follicular stage. The maintenance of dormancy and activation of primordial follicles are controlled by coordinated actions of a suppressor/activator with close communications with somatic cells and intra-oocyte signaling pathways. Many growth factors and signaling pathways have been identified and the transforming growth factor-beta superfamily plays important roles in early folliculogenesis. However, the mechanism of maintaining the dormancy and survival of primordial follicles has remained unknown for decades. Recently, since the first finding that all primordial follicles are activated prematurely in mice deficient forkhead box O3a, phosphatidylinositol 3 kinase/phosphatase and tensin homolog (PTEN) signaling pathway was reported to be important in the regulation of dormancy and initial follicular activation. With these informations on early folliculogenesis, clinical application can be expected such as in vitro maturation of immature oocytes or in vitro activation of follicles by PTEN inhibitor in cryopreserved ovarian cortical tissues for fertility preservation.
卵巢卵泡最初由原始卵泡发育而来。大多数卵巢原始卵泡处于静止状态，作为生殖寿命的储备。只有少数被激活并发育到高级卵泡阶段。原始卵泡休眠的维持和激活受与体细胞和卵母细胞内信号通路密切通讯的抑制因子/激活因子的协同作用控制。已鉴定出许多生长因子和信号通路，转化生长因子-β超家族在早期卵泡发生中起重要作用。然而，几十年来，维持原始卵泡休眠和存活的机制一直不明。最近，自从首次发现叉头框O3a缺陷小鼠中所有原始卵泡过早激活以来，据报道磷脂酰肌醇3激酶/磷酸酶和张力蛋白同源物（PTEN）信号通路在休眠调节和初始卵泡激活中很重要。有了这些关于早期卵泡发生的信息，有望实现临床应用，如未成熟卵母细胞的体外成熟或在冷冻保存的卵巢皮质组织中用PTEN抑制剂进行卵泡的体外激活以保存生育能力。
