Molecular Pathways Controlling Ovarian Gene Expression

描述(由申请人提供)：基因的协调激活和抑制对于卵巢周期的正常进行是必不可少的。卵巢颗粒细胞高水平表达转录因子GATA-4和GATA-6。在细胞培养中，这些转录因子被证明在参与类固醇合成的酶的表达中发挥关键作用。我们已经在最近发表的几篇论文中证明了GATA-4对雌二醇的产生至关重要，雌二醇是颗粒细胞增殖和卵泡成熟所必需的。此外，GATA-4低表达与卵泡细胞死亡相关的发现表明，该因子在卵巢中也起着生存作用。由于GATA-4和GATA-6基因缺失的小鼠是胚胎致死的，GATA在卵巢功能中的最终作用尚不清楚。因此，本研究旨在确定GATA-4和GATA-6在卵巢类固醇生成、卵泡发育和女性生育中的生理作用。本研究的具体目的是：1-建立卵巢特异的GATA-4和GATA-6缺失小鼠，以了解这些转录因子在体内卵巢中的作用。Cre-lox技术将用于删除GATA-4、GATA-6或它们的组合的部分编码区。我们预计这些小鼠在类固醇产生和卵泡发育方面存在严重缺陷。2-检测GATA-4和GATA-6缺失对体外培养的卵巢细胞的影响。缺乏GATA-4和/或GATA-6的颗粒细胞将被用来研究这些因子在类固醇生成、细胞增殖、颗粒细胞激素反应和基因表达中的特定作用。3-为了在体内确定在全功能卵巢中受GATA-4和GATA-6调控的那些基因，我们将使用芯片分析。所有这些结果表明，GATA-4和GATA-6可能在卵巢的正常功能中发挥重要作用。我们希望通过这项研究明确GATA-4和GATA-6在颗粒细胞的类固醇合成能力和生长中的作用，确定GATA-4和GATA-6是否对这些细胞有多余的作用，并鉴定卵巢中的GATA-4和GATA-6靶基因。本研究不仅将为卵巢功能正常的调控机制提供重要的信息，而且可能为颗粒细胞功能异常所致的卵巢疾病，如颗粒细胞瘤和不孕症等提供重要的信息。

DESCRIPTION (provided by applicant): Coordinated activation and repression of genes are essential for the normal progress of the ovarian cycle. Ovarian granulosa cells express high levels of the transcription factors GATA-4 and GATA-6. In cell cultures, these transcription factors were shown to play key roles in the expression of enzymes involved in steroidogenesis. We have demonstrated in several recently published papers that GATA-4 is critical for the production of estradiol, which is essential for granulosa cell proliferation and follicle maturation. In addition, the finding that low expression of GATA-4 is associated with follicular cell death suggests that this factor also plays a survival role in the ovary. Because GATA-4 and GATA-6 null mice are embryonic lethal, the ultimate role of GATA in ovarian function remains unknown. This study is therefore designed to determine the physiological role of GATA-4 and GATA-6 in ovarian steroidogenesis, follicular development, and female fertility. The specific aims of this study are: 1- To generate ovarian-specific GATA-4 and GATA-6 null mice in order to find out the explicit roles of these transcription factors in the ovary in vivo. The Cre-lox technology will be used to delete part of the coding region of GATA-4, GATA-6, or their combination. We expect these mice to have severe defects in steroid production and in follicular development. 2- To determine the effect of GATA-4 and GATA-6 deletion on ovarian cells in vitro. Granulosa cells lacking GATA-4, GATA-6, or both will be used to examine the specific roles of these factors in steroidogenesis, cell proliferation, granulosa-cell hormone response, and gene expression. 3- To identify those genes that are regulated by GATA-4 and GATA-6 in fully functional ovaries in vivo, we will use ChIP-on-chip assays. All the results obtained to date indicate that GATA-4 and GATA-6 may play a crucial role in the normal function of the ovary. We expect from this investigation to clearly define the function of GATA-4 and GATA-6 in the steroidogenic capacity and growth of granulosa cells, to determine whether GATA-4 and GATA-6 have redundant effects on these cells, and to identify GATA-4 and GATA-6 target genes in the ovary. This study will not only provide critically important information on the regulatory mechanism underlying normal ovarian function but also may shed light on ovarian diseases due to improper granulosa cell function such as granulosa cell tumors and infertility.