Estrogen receptor and the cardiovascular system

项目摘要/摘要 雌激素的作用已经在动物模型中显示出来，并在一定程度上在人类身上显示出缓解各种形式的 心血管疾病，包括高血压、动脉粥样硬化和缺血/再灌注损伤。雌激素作用 在它的受体，ERpha和ERbeta。也有强有力的数据表明，雌激素可以防止癌症的发生 心肌肥大、纤维化和进展为心力衰竭，特别是在与人类相关的动物模型中 在病程的早期就开始。雌激素的这些作用主要是通过作用于 ERbeta异构体，尤其是来自刺激信号转导的膜局部池。 ERbeta的一个潜在靶点是重要的转录因子KLF15，它被认为具有抗 肥大的特性。使用与小剂量血管紧张素II(Ang II)有关的人类疾病模型 卵巢切除、野生型和ERbeta KO雌性小鼠输液超过4周即可发生。Angii的影响 雌二醇(E_2)或ERβ特异性激动剂-LGND_2被用来确定对 这种转录因子在左心室中，假设膜上的E2/ERβ信号恢复 单用血管紧张素转换酶抑制KLF15的表达。雄鼠也将接受调查。此外，在- 利用培养的、新鲜分离的新生大鼠心肌细胞进行的体外研究将确定血管紧张素转换酶是否减少， 虽然E2或BLGND恢复了KLF15的核定位，并与重要的肥大相互作用- 控制Myocardin、SRF、GATA-2和MEF等核蛋白，并招募表观遗传调节因子 包括HDAC 2和5，以及P300。我们认为这调节重要的肌细胞效应基因/蛋白。 表达和肌细胞功能将会被确定。将确定核ER是否有贡献 在2种细胞选择性内质网池丢失模型中。 一种重要的心血管蛋白及其心肌细胞膜受体apelin和apj分别是 已知可减缓心肌肥大、纤维化和疾病进展。可能是因为 膜ERbeta信号和作用需要这一复合体和该系统的大量激活 和功能层面。这将在体外和体内确定，后者使用卵巢切除、野生型、 ERbeta KO和心肌细胞特异性APJ KO小鼠(CRE-Flox)。这个模型将明确地暗示这一角色 APJ在这些细胞中的作用，以减轻体内血管紧张素转换酶对血压和心脏的影响 肥大、纤维化和心脏功能受损。雄鼠也将被使用。 考虑一种专有的ERbeta激动剂最终是否可以用于 人类是否1)激活ERbeta逆转已确定的疾病，以及2)这是否可能是相关的 对雄性哺乳动物来说。卵巢切除后4周Angii+/-E_2或BLGND模型 WT和ERbeta KO小鼠，Angii比雌激素化合物注射早两周开始， 足以引起心脏改变。这测试了这种早期疾病状态是否可以被E2或 BLGND。此外，还将在#年开展血管紧张素转换酶抑制剂对心脏病的治疗和预防研究。 雌二醇组或补阳还五汤治疗雄性小鼠，包括血管紧张素转换酶诱导的高血压的正常化。ER是否 E2的降压作用也将在ERKO小鼠身上确定。

Project Summary/Abstract Estrogen action has been shown in animal models and to an extent in humans to mitigate various forms of cardiovascular disease, including hypertension, atherosclerosis, and ischemia/reperfusion injury. Estrogen acts at its receptors, ERalpha and ERbeta. There is also strong data that estrogen prevents the development of cardiac hypertrophy, fibrosis, and progression to heart failure, particularly in human-relevant animal models when started early in the course of disease. These effects of estrogen are mainly through actions at the ERbeta isoform, especially from the membrane-localized pool that stimulates signal transduction. One potential target of ERbeta is the important transcription factor, KLF15 that is proposed to have anti- hypertrophic properties. Using a relevant model for human disease, involving low dose Angiotensin II (Ang II) infusion over 4 weeks in ovariectomized, wild type and ERbeta KO female mice will occur. The impact of AngII and estradiol (E2) or an ERbeta-specific agonist, -LGND2, is used to determine effects on the expression of this transcription factor in the left cardiac ventricle, postulating that membrane E2/ERbeta signaling restores the expression of KLF15 that is reduced by AngII alone infusion. Male mice will also be investigated. Also, in- vitro studies using cultured, freshly isolated neonatal rat cardiomyocytes will determine whether AngII reduces, while E2 or BLGND restores nuclear localization of KLF15, and interaction with important hypertrophy- controlling nuclear proteins such as myocardin, SRF, GATA-2 and MEF, and recruit epigenetic regulators including HDACs 2 and 5, and p300. We propose this regulates important myocyte effector genes/protein expression and myocyte function that will be determined. Whether nuclear ERcontributes will be determined in 2 cell models of cell-selective ER pool loss. An important cardiovascular protein and its myocyte cell membrane receptor, apelin and APJ respectively, are known to mitigate the development of cardiac hypertrophy, fibrosis, and disease progression. It may be that membrane ERbeta signaling and actions require this complex and activation of this system at the abundance and functional levels. This will be determined in-vitro and in-vivo, the latter using ovariectomized, wild type, ERbeta KO, and cardiomyocyte-specific APJ KO mice (Cre-Flox). This model will definitively implicate the role of APJ in these cells for the action of E2/ERbeta to mitigate in-vivo AngII effects on blood pressure and cardiac hypertrophy, fibrosis, and cardiac functional compromise. Male mice will also be used. Two compelling issues in considering whether a proprietary ERbeta agonist could eventually be used in humans are whether ERbeta activation 1) reverses established disease, and 2) whether this might be relevant to male mammals. The 4 week model of AngII infusion +/- E2 or BLGND will be done in ovariectomized female WT and ERbeta KO mice, where AngII is started 2 weeks earlier than estrogenic compound administration, sufficient to induce cardiac changes. This tests whether this early disease state can be reversed by E2 or BLGND. Also, treatment and prevention studies of cardiac disease from AngII infusion will be carried out in male mice treated with E2 or BLGND including normalization of AngII-induced hypertension. Whether ER contributes to the anti-hypertensive effects of E2 will also be determined using ER KO mice.