Molecular Pathways Controlling Ovarian Gene Expression

描述（由申请人提供）：基因的协同激活和抑制对卵巢周期的正常进展至关重要。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生成的酶的表达中起关键作用。我们在最近发表的几篇论文中证明，GATA-4对雌二醇的产生至关重要，而雌二醇对颗粒细胞增殖和卵泡成熟至关重要。此外，低表达GATA-4与卵泡细胞死亡相关的发现表明，该因子在卵巢中也起生存作用。由于GATA-4和GATA-6缺失小鼠是胚胎致死性的，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能力中的生理作用。本研究的具体目的是：1-生成卵巢特异性GATA-4和GATA-6缺失小鼠，在体内找出这些转录因子在卵巢中的明确作用。Cre-lox技术将用于删除GATA-4、GATA-6或其组合的部分编码区。我们预计这些小鼠在类固醇产生和卵泡发育方面有严重缺陷。2-测定GATA-4和GATA-6缺失对体外卵巢细胞的影响。颗粒细胞缺乏GATA-4， GATA-6，或两者都将用于检查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具体作用。为了鉴定体内功能齐全的卵巢中受GATA-4和GATA-6调控的基因，我们将使用ChIP-on-chip检测。这些结果表明GATA-4和GATA-6可能在卵巢的正常功能中起着至关重要的作用。我们希望通过本研究明确GATA-4和GATA-6在颗粒细胞的类固醇生成能力和生长中的功能，确定GATA-4和GATA-6是否对颗粒细胞有冗余作用，并鉴定卵巢中GATA-4和GATA-6的靶基因。该研究不仅将为了解卵巢正常功能的调控机制提供重要信息，而且还可能揭示颗粒细胞功能不正常导致的卵巢疾病，如颗粒细胞肿瘤和不孕症。

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.