Vascular AT2R expression and function during pregnancy

妊娠期间血管AT2R的表达和功能

基本信息

批准号：
9981801
负责人：
SATHISH KUMAR
金额：
$ 38.25万
依托单位：
UNIVERSITY OF WISCONSIN-MADISON
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-08-15 至 2023-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9981801
关键词：
Address Affect Agonist Angiotensin II Animals Antihypertensive Agents Arteries Biological Assay Blood Blood Pressure Blood Vessels Blood flow Cardiovascular system Clinical Data Dimensions Disease Dose Down-Regulation EMSA Endothelial Cells Endothelium Epoprostenol Equilibrium Estradiol Estrogen Receptor alpha Estrogen Receptor beta Estrogen Receptors Estrogen receptor positive Estrogens Europe Failure Fetus Functional disorder Genetic Transcription Growth Human Hypertension Intervention Studies Ligand Binding Measurement Measures Mediating Membrane Potentials Mesenteric Arteries Metabolic Modeling Molecular Mothers Mus Nitrates Nitrites Nutrient Oral Organ Pathway interactions Patients Peptides Perfusion Placenta Play Pre-Eclampsia Pregnancy Pregnant Women Process Production Rattus Receptor Activation Receptor, Angiotensin, Type 1 Relaxation Reporter Research Response Elements Rodent Model Role Signal Transduction Small Interfering RNA Solid System Systemic blood pressure Tail Testing Therapeutic Therapeutic Uses Translating Type 2 Angiotensin II Receptor Up-Regulation Uterus Vascular Diseases Vascular Smooth Muscle Vascular resistance Vascularization Vasoconstrictor Agents Vasodilation base blood pressure reduction clinically relevant endothelial dysfunction fetal improved in vivo knock-down novel novel therapeutics oxygen transport pregnancy hypertension pregnant promoter receptor receptor expression receptor function receptor upregulation response targeted treatment transcription factor translational study vasoconstriction

项目摘要

ABSTRACT In pregnancy, endothelial vasodilation is enhanced to decrease blood pressure and increase uterine blood flow. Pregnancy-enhanced vasodilatory function is achieved through an increase in expression of angiotensin type 2 receptor (AT2R) in the endothelium of uterine and systemic vasculature. In preeclampsia, this adaptive endothelial response fails due to downregulation of AT2R expression and activity, with associated endothelial dysfunction, increased vascular resistance, and hypertension. Preeclampsia affects 5%–8% of all pregnancies, and treatment is limited to antihypertensives that relax vascular smooth muscle. There is no treatment to directly address endothelial failure. The cause of preeclampsia is not known, but the pregnancy-specific upregulation of AT2R in the vasculature may hold important keys to understanding the origins of the disease and the underlying causes of maternal organ function. The opportunity to study the effects of novel oral nonpeptide Compund21 is significant and valuable. Based on solid preliminary data, we propose that pregnancy selectively upregulates endothelial AT2R via differential binding of ligand-activated estrogen receptor (ie, ERβ vs ERα) to a functional estrogen response element (ERE) in the AT2R promoter. Failure of vascular AT2R upregulation during pregnancy plays a role in endothelial cell dysfunction and vasoconstriction in preeclampsia and, consequently, activation of this system reverses preeclamptic vascular dysfunction. Aim 1 will first establish pregnancy-specific upregulation of AT2R in the endothelium and then define the mechanistic role of ER α or β in upregulation of AT2R by using ER-specific agonists, antagonists, and siRNA in rodent models. AT2R transcription mechanisms will determine differential binding of ligand- activated ER and transcription factors to putative ERE in AT2R promoter in primary human uterine artery endothelial cells, using ChiP and EMSA/ supershift assays, and then use reporter assays to determine their functionality. Aim 2 will move towards clinical translational relevance. We will determine if vascular AT2R is involved in preeclamptic endothelial dysfunction and if AT2R activation rescues vascular dysfunction. To test the AT2R-mediated mechanisms, EDHF, NO, and PGI2 pathways of vascular relaxation pathways will be determined. Also, the expression of eNOS and its activity state—signaling components of EDHF and PGI2 pathways as well as nitrate/ nitrite and PGI2 production and changes in membrane potential—will be measured. Aim 3 will verify the AT2R effects in vivo. We will use 2 models of gestational hypertension to test the effect of 2 selective AT2R agonists (CGP-42112 peptide and Compound 21) on the maternal, placental, and fetal abnormalities associated with preeclampsia. These studies will provide new information of how pregnancy increases endothelial AT2R and that failure of this process leads to preeclamptic endothelial dysfunction. The positive translational significance of these aims is that they evaluate the therapeutic utility of an endothelium- targeted therapy which is potentially safe in preeclampsia subjects.

抽象的在怀孕中，内皮血管舒张得到增强，以降低血压并增加子宫血流。通过增加血管紧张素2型的表达来实现妊娠增强的血管舒张功能子宫内皮和全身脉管系统的受体（AT2R）。在先兆子痫中，这种适应性内皮反应由于AT2R表达和活性的下调而失败，相关内皮功能障碍，血管抗性增加和高血压。 Preclamsia影响所有怀孕的5％–8％，治疗仅限于降压血管平滑肌的抗高血压。没有治疗直接解决内皮失败。先兆子痫的原因尚不清楚，但特定于妊娠的原因脉管系统中AT2R的上调可能具有重要的关键来理解该疾病的起源以及母体器官功能的根本原因。研究新口腔影响的机会非肽摄入21具有重要意义和有价值。基于可靠的初步数据，我们建议怀孕通过配体激活的雌激素的差异结合选择性上调内皮AT2R AT2R启动子中功能性雌激素反应元件（ERE）的受体（IE，ERβ与ERα）。失败怀孕期间的血管AT2R上调在内皮细胞功能障碍和先兆子痫的血管收缩，因此，该系统的激活逆转了先兆血管功能障碍。 AIM 1将首先在内皮中建立AT2R的特定妊娠上调，然后建立通过使用ER特异性激动剂，拮抗剂和啮齿动物模型中的siRNA。 AT2R转录机制将确定配体的差异结合在原发性子宫动脉中激活的ER和转录因子AT2R启动子中推定的ERE 内皮细胞，使用芯片和EMSA/ supershift分析，然后使用记者测定法确定其功能。 AIM 2将朝着临床翻译相关性发展。我们将确定血管AT2R是否为涉及前疗法的内皮功能障碍，如果AT2R激活会挽救血管功能障碍。测试血管松弛途径的AT2R介导的EDHF，NO和PGI2途径将是决定。此外，eNOS的表达及其活性状态 - EDHF和PGI2的信号成分途径以及硝酸盐/亚硝酸盐和PGI2的产生以及膜电位变化 - 将是测量。 AIM 3将在体内验证AT2R效应。我们将使用2种妊娠高血压模型进行测试 2种选择性AT2R激动剂（CGP-42112胡椒和化合物21）对母体，斑点和胎儿异常与先兆子痫有关。这些研究将提供有关怀孕方式的新信息增加内皮AT2R，并且该过程的失败导致先兆内皮功能障碍。这这些目标的积极翻译意义是，它们评估了内皮的治疗效用 - 靶向治疗在先兆子痫受试者中可能是安全的。