Granulosa cell apoptosis induced at the penultimate stage of follicular development is associated with increased levels of Fas and Fas ligand in the rat ovary
Granulosa cell apoptosis induced at the penultimate stage of follicular development is associated with increased levels of Fas and Fas ligand in the rat ovary
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DOI：
10.1095/biolreprod58.5.1170
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发表时间：
1998-05-01
影响因子：
3.6
通讯作者：
Tsang, BK
中科院分区：
文献类型：
--
作者：
Kim, JM;Boone, DL;Tsang, BK
颗粒细胞凋亡是卵巢滤泡闭锁的细胞机制，细胞因子被认为是潜在的致闭锁因子。因此，我们研究了细胞因子Fas配体（FasL）及其受体Fas在促性腺激素停药诱导的卵泡闭锁中凋亡的可能作用。经eCG预处理的未成熟大鼠24 h后注射针对eCG生成的抗血清（抗体组）或免疫前兔血清（对照组），并在处理后1和24 h切除卵巢。心电图抗血清对心电图治疗后24 - 48小时卵巢重量的显著增加有剂量依赖性抑制作用。在组织切片中原位检测DNA片段，发现抗体组闭锁但不健康的中小窦卵泡细胞死亡。细胞死亡在闭锁小卵泡颗粒细胞层呈分散分布，但主要局限于闭锁中卵泡腔内的颗粒细胞。邻近组织切片的免疫组化显示，闭锁的小、中腔滤泡颗粒细胞中Fas和Fast的免疫染色强烈阳性，其模式与细胞死亡的定位一致。健康小窦卵泡的卵泡细胞呈强烈的Fast染色。抗体组颗粒细胞中提示凋亡的低分子量DNA （DNA“阶梯”）明显增加。Western分析显示抗体组颗粒细胞中Fas和Fast水平升高。这些结果表明，Fas和Fast都存在于卵巢颗粒细胞中，Fast可能是卵巢卵泡发育倒数第二阶段闭锁期间颗粒细胞凋亡的信号。
Apoptosis of granulosa cells is the cellular mechanism of ovarian follicular atresia, and cytokines have been implicated as potential atretogenic factors. We therefore investigated the possible role of the cytokine Fas ligand (FasL) and its receptor Fas in apoptosis during ovarian follicular atresia induced by gonadotropin withdrawal. Immature rats pretreated with eCG were injected 24 h later with an antiserum generated against eCG (antibody group) or preimmune rabbit serum (control), and ovaries were removed 1 and 24 h after treatment. The eCG antiserum caused a dose-dependent inhibition of the significant increase in ovarian weight observed between 24 and 48 h after eCG treatment. In situ detection of fragmented DNA in histological sections identified cell death in atretic but not healthy small and medium-sized antral follicles of the antibody group. Cell death was distributed in a scattered pattern throughout the granulosa cell layer of small atretic follicles but was localized primarily in granulosa cells lining the antral cavity of atretic medium antral follicles. Immunohistochemistry of adjacent histological sections revealed intense positive immunostaining for Fas and Fast in granulosa cells of atretic small and medium antral follicles in a pattern coincidental to the localization of cell death. Intense Fast staining was evident in the theca cells of healthy small antral follicles. An increase in low molecular weight DNA (DNA "ladders") indicative of apoptosis was evident in granulosa cells of the antibody group. Western analysis demonstrated increased levels of both Fas and Fast in the granulosa cells of the antibody group. These results demonstrate that both Fas and Fast are present in ovarian granulosa cells and that Fast may be the signal that induces granulosa cell apoptosis during atresia at the penultimate stage of ovarian follicular development.