Estrogen receptor Alpha/Beta antagonism in osteoblasts

描述（由申请人提供）：雌激素是生长的关键调节因子， 和维持两性的骨量。雌激素受体的两种亚型， ER α和ER β，通过结合介导雌激素的转录作用 17-β雌二醇（E2），随后与细胞内的特定元素结合， 基因的调控区。尽管我们和其他人已经证明， ER α和ER β在成骨细胞中起作用，但数据很少 关于ER α和ER β在骨中的相互作用。近期基因缺失 在小鼠中的实验表明，ER α和ER β亚型可能具有 通过与PR的A和B同种型类比，对骨的相反作用，其中 PR-A是PR-B的抑制剂。一种机制可以解释 ER α和ER β的拮抗作用涉及不同的 类固醇受体辅激活因子（SRCs）的募集， 转录信号传递到基础转录机制。因此 本研究的目的是了解 人成骨细胞中ER α/α和ER β/β同源二聚体的研究 ER α/β异源二聚体对人类基因转录的影响 成骨细胞该项目将试图解决这些基本的生物学问题， 问题使用三种方法：1）了解ER α/β的影响 异源二聚体对典型雌激素反应转录潜能的影响 在hFOB和MG-63细胞系中，在SP1/（ERE 1/2）位点处的ERE和SP1/（ERE 1/2）位点; 2） 确定类固醇受体辅激活剂（SRC）的募集通过各种ER 同源二聚体和异源二聚体;以及最后3）确定 ER α/α、ER β/β和ER α/β在人OB细胞中的表达， 基因芯片技术

DESCRIPTION (provided by applicant): Estrogen is a key regulator in the growth and maintenance of bone mass in both sexes. Two isoforms of estrogen receptor, ERalpha and ERbeta, mediate the transcriptional effects of estrogen by binding 1 7-beta.estradiol (E2) and subsequently binding to specific elements within the regulatory regions of genes. Although we, and others, have shown that ERalpha and ERbeta are functional in osteoblasts, little data are available concerning the interactions of ERalpha and ERbeta in bone. Recent gene deletion experiments in mice suggest that the ERalpha and ERbeta isoforms may have opposing actions on bone, by analogy with the A and B isoforms of PR, where PR-A is an inhibitor of PR-B. One mechanism to explain the potential antagonistic effects of ERalpha and ERbeta would involve the differential recruitment of steroid receptor coactivators (SRCs), which transmit the transcriptional signal to the basal transcriptional machinery. Therefore, the purpose of this research proposal is to understand the functions of ERalpha/alpha and ERbeta/beta homodimers in human osteoblasts and to understand the effects of the ERalpha/beta heterodimer on gene transcription in human osteoblasts. The project will attempt to address these basic biological questions using three approaches: 1) to understand the effects of ERalpha/beta heterodimers on the transcriptional potential at canonical estrogen response elements (EREs) and at SP1/(ERE1/2) sites in hFOB and MG-63 cell lines; 2) determine the recruitment of steroid receptor coactivators (SRCs) by various ER homo- and heterodimers; and finally 3) determine the in vivo consequences of ERalpha/alpha, ERbeta/beta and ERalpha/beta expression in human OB cells using gene chip technology.