Regulation of IGFBP-1 by FKHR and HOXA10 in pregnancy

描述（由申请人提供）：本申请的长期目标是更好地了解孕体和母亲之间发生的动态相互作用，从而建立和维持妊娠。我们研究的主要焦点是子宫内膜对早期胚胎信号和滋养层细胞入侵的分子反应。在此期间子宫内膜中基因的异常表达不利于维持妊娠，并可能导致流产，自然流产和不孕症。子宫内膜对妊娠激素和孕体因子的反应是发生主要的转化，称为蜕膜化。在此过程中，子宫内膜的基质细胞表达重要的基因。本研究的重点是蜕膜基质细胞的主要分泌产物，胰岛素样生长因子结合蛋白-1（IGFBP-1）的调节。IGFBP-1调节胰岛素样生长因子（IGFs）的作用，IGFs在妊娠早期至关重要，并且可以独立于IGFs调节滋养层侵袭。最近，我们证明，两个转录因子，FKHR和HOXA 10，这已被证明是重要的生殖过程中，相互作用，并上调IGFBP-1启动子在子宫内膜间质细胞中的合作方式。基于这一新的数据，设计了研究以进一步阐明FKHR和HOXA 10协同上调IGFBP-1启动子的机制。在目的1中，鉴定IGFBP-1启动子上FKHR和HOXA 10的结合位点。使用一种强大的新技术，染色质免疫沉淀（CHIP），内源性FKHR和HOXA 10蛋白的结合位点的内源性IGFBP-1基因内的染色质在蜕膜基质细胞的确定。该技术允许研究转录因子与染色质的相互作用，因为它们在原位发生。在目标2中，将通过使用甲醛交联拍摄细胞和组织的"快照"，对FKHR和HOXA 10进行表征，并测定源自非妊娠和妊娠狒狒子宫内膜的细胞中IGFBP-1基因的结合序列。这些研究将证明孕体对FKHR和HOXA 10表达及其对IGFBP-1基因激活的影响。在目标3中，将研究患有子宫内膜异位症的狒狒的子宫内膜中FKHR和HOXA 10的表达和活性。目的3的目的是确定为什么FKHR和HOXA 10不显著激活IGFBP-1启动子。狒狒子宫内膜异位症的间质细胞与正常动物的间质细胞明显不同。这些研究将使我们更好地了解可能与子宫内膜异位症妇女着床失败增加相关的分子事件。该应用的三个目标将为子宫内膜对妊娠反应的分子动力学提供有价值的见解。

DESCRIPTION (provided by applicant): The long-term objective of this application is to better understand the dynamic interaction that occurs between the conceptus and the mother that allow for the establishment and maintenance of pregnancy. The major focus of our research is on the molecular events that occur in the endometrium in response to early embryonic signals and the invading trophoblast. Aberrant expression of genes in the endometrium during this time is detrimental to the maintenance of pregnancy and could lead to miscarriages, spontaneous abortions and infertility. In response to pregnancy hormones and conceptus factors, the endometrium undergoes a major transformation, termed decidualization. During this process, the stromal cells of the endometrium express important genes. This study focuses on the regulation of a major secretory product of the decidualizing stromal cells, insulin-like growth factor binding protein-1 (IGFBP-1). IGFBP-1 modulates the actions of insulin-like growth factors (IGFs) which are critical during early pregnancy and can act independently of IGFs to regulate trophoblast invasion. Recently, we demonstrated that two transcription factors, FKHR and HOXA10, which have been demonstrated to be important in reproductive processes, interact with one another and up regulate the IGFBP-1 promoter in a cooperative manner in endometrial stromal cells. Based on this novel data, studies have been designed to further delineate the mechanisms involved in the cooperative up regulation of the IGFBP-1 promoter by FKHR and HOXA10. In aim 1 the binding sites of FKHR and HOXA10 on the IGFBP-1 promoter are identified. With the use of a powerful new technique, chromatin immunoprecipitation (CHIP), the binding sites for endogenous FKHR and HOXA10 proteins on the endogenous IGFBP-1 gene within the chromatin in the decidualized stromal cells are determined. This technique allows one to study interaction of transcription factors with the chromatin as they occur in situ. In aim 2, characterization of FKHR and HOXA10 and determination of binding sequences on the IGFBP-1 gene in cells originating from non-pregnant and pregnant baboon endometrium will be performed by taking "snapshots" of the cells and tissue using formaldehyde cross linking. These studies will demonstrate the influence of the conceptus on FKHR and HOXA10 expression and their activation of the IGFBP-1 gene. In aim 3, FKHR and HOXA10 expression and activity in the endometrium of baboons with endometriosis will be studied. The objective of aim 3 is to determine why FKHR and HOXA10 do not significantly activate the IGFBP-1 promoter. The stromal cells from baboons with endometriosis are obviously different from that of a normal animal. These studies will give a better understanding of the molecular events that may be associated with increased implantation failure in women with endometriosis. The three aims in this application will provide valuable insights into the molecular dynamics of the endometrium in response to pregnancy.