Regulation of IGFBP-1 by FKHR and HOXA10 in pregnancy

描述(由申请者提供)：本申请的长期目标是更好地理解妊娠与母亲之间发生的动态相互作用，从而建立和维持妊娠。我们的研究主要集中在子宫内膜对早期胚胎信号和滋养细胞入侵的反应中发生的分子事件。在此期间，子宫内膜基因的异常表达不利于妊娠的维持，并可能导致流产、自然流产和不孕不育。在妊娠激素和妊娠因素的作用下，子宫内膜经历了一个重要的变化，称为蜕膜化。在这个过程中，子宫内膜的间质细胞表达重要的基因。本研究的重点是胰岛素样生长因子结合蛋白-1(IGFBP-1)对分化基质细胞的主要分泌产物的调节作用。IGFBP-1调节胰岛素样生长因子(IGF)的作用，IGF在妊娠早期是至关重要的，并且可以独立于IGFS发挥作用，调节滋养细胞的侵袭。最近，我们证明了两个转录因子FKHR和HOXA10在子宫内膜间质细胞中相互作用并协同上调IGFBP-1启动子，这两个转录因子在生殖过程中起重要作用。基于这一新的数据，设计了进一步描述FKHR和HOXA10协同上调IGFBP-1启动子的机制。目的1确定FKHR和HOXA10在IGFBP-1启动子上的结合部位。应用染色质免疫沉淀(ChIP)技术，研究了蜕膜间质细胞中内源性FKHR和HOXA10蛋白与内源性IGFBP-1基因的结合部位。这项技术使人们能够研究转录因子与染色质在原位发生时的相互作用。在目标2中，FKHR和HOXA10的特征和IGFBP-1基因结合序列的测定将通过使用甲醛交联剂拍摄细胞和组织的快照来完成。这些研究将证明胚胎对FKHR和HOXA10表达的影响及其对IGFBP-1基因的激活。在目标3中，我们将研究FKHR和HOXA10在子宫内膜异位症患者子宫内膜中的表达和活性。目的3的目的是确定为什么FKHR和HOXA10不能显著激活IGFBP-1启动子。患有子宫内膜异位症的狒狒的间质细胞与正常动物的间质细胞明显不同。这些研究将更好地了解可能与子宫内膜异位症患者植入失败增加有关的分子事件。这项应用的三个目标将为研究子宫内膜对怀孕的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.