Sex-specific fetal programming of adult vascular dysfunction and hypertension

成人血管功能障碍和高血压的性别特异性胎儿编程

• 批准号: 8853942
• 负责人: SATHISH KUMAR
• 金额: $ 38.17万
• 依托单位: UNIVERSITY OF TEXAS MED BR GALVESTON
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-09 至 2016-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8853942
• 关键词: Adult; Affect; African American; American; Androgens; Antiandrogen Therapy; Binding; Biological Assay; Blood Pressure; Blood Vessels; Cardiovascular Diseases; Cardiovascular system; Child; Clinical; Connexins; Development; Disease; Endothelium; Environment; Epidemiologic Studies; Event; Exhibits; Female; Fetus; Flutamide; Functional disorder; Gender; Hypertension; Impairment; Indium; Isoenzymes; Knowledge; Link; Measures; Mediating; Membrane Potentials; Mesentery; Messenger RNA; Modeling; Molecular; Molecular Profiling; Monitor; Muscle Contraction; Muscle Proteins; Nitric Oxide; Obesity; Pathogenesis; Pathology; Pathway interactions; Phenotype; Phosphorylation; Pre-Eclampsia; Pregnancy; Prevention strategy; Production; Protein Isoforms; Protein Kinase C; Proteins; Public Health; Rattus; Reporter; Reporting; Risk; Role; Series; Severities; Sex Characteristics; Signal Transduction; Smoking; Stimulus; Stress; Subcellular Fractions; Testing; Testosterone; Up-Regulation; Vascular Diseases; Vascular Smooth Muscle; Vasoconstrictor Agents; Vasodilation; Vasodilator Agents; Withdrawal; Woman; base; cardiovascular disorder risk; cardiovascular risk factor; chromatin immunoprecipitation; clinically relevant; endothelial dysfunction; fetal programming; functional status; hypertension treatment; improved; in utero; insight; male; novel; offspring; postnatal; pregnant; prenatal; programs; promoter; public health relevance; research study; response; sex

DESCRIPTION (provided by applicant): Epidemiological studies show increased risk of cardiovascular (CV) diseases in children born to women with compromised pregnancies, such as in preeclampsia, PCOS, protein or energy restriction, obesity, stress, and smoking, but its pathogenesis remains incompletely understood. As one of the common factors observed in these pregnancy pathologies, elevated maternal testosterone (T) is likely to contribute to the fetal programming of CV disorders. Indeed, our recent studies demonstrate that elevated maternal T causes development of hypertensive phenotypes in rat offspring. To understand the mechanisms, 2 central hypotheses are proposed in this project. First, prenatal T induces sex-specific onset and severity of hypertension, and these hypertensive responses are mediated by postnatal increases in T levels. Second, increase in postnatal T induces hypertensive responses through sex-specific dysfunctions in vascular smooth muscle (VSM) protein kinase C (PKC) and endothelial EDHF/NO expression/function. To test these hypotheses, we propose a series of experiments in our established pregnant rat model and examine their offspring. Three specific aims are proposed: 1) Determine whether elevated maternal T programs offspring's hypertension, with more pronounced effect in males than females, and if postnatal T increase precedes hypertension onset. We will telemetrically monitor progressive changes in blood pressure (BP) and measure T levels to establish a relationship between onset and severity of hypertension and changes in postnatal T levels, mechanistically determining if postnatal T increase is the key contributing factor for BP increase. 2) Evaluate the sex-specific hypertensive mechanisms in VSM. We will examine the PKC isoenzyme expression profile in subcellular fractions, its phosphorylation status, and functional activity and examine mechanisms by which androgens regulate PKC expression by assessing binding of T to putative ARE in PKC promoter by ChiP and reporter assays. 3) Dissect the sex-specific mechanisms of impaired endothelial functions. We will examine the EDHF- and NO-mediated pathways and evaluate the mechanisms for impaired EDHF-mediated vasodilation by determining mRNA and protein levels of EDHF components SK3 and IK1 channels and connexins (CX37, CX40, and CX47), their subcellular localization, and functional activity using vascular reactivity and membrane potential studies. We will investigate the role of impaired NO-mediated vasodilator function by assessing the expression of eNOS, its activity, NO production, and signaling events. We expect that in utero T exposure will cause gender-specific hypertensive effects through upregulation of distinct vascular PKC isoenzymes and differential endothelial dysfunctions in the male and female vasculature, which may be regulated through postnatal changes in T levels. The results will provide a novel molecular basis to the understanding of fetal programming of adult CV dysfunction and improve our knowledge of sex differences in vascular dysfunction, providing an exciting opportunity to devise sex-specific strategies for prevention and treatment of hypertension.

描述（由申请人提供）：流行病学研究表明，妊娠受损的妇女所生的孩子患心血管（CV）疾病的风险增加，例如先兆子痫、多囊卵巢综合症、蛋白质或能量限制、肥胖、压力和吸烟，但其发病机制仍然存在不完全理解。作为这些妊娠病理中观察到的常见因素之一，母体睾酮 (T) 升高可能会导致胎儿出现心血管疾病。事实上，我们最近的研究表明，母体 T 升高会导致大鼠后代出现高血压表型。为了理解其机制，该项目提出了 2 个中心假设。首先，产前 T 会诱发性别特异性的高血压发病和严重程度，而这些高血压反应是由产后 T 水平升高介导的。其次，出生后 T 的增加通过血管平滑肌 (VSM) 蛋白激酶 C (PKC) 和内皮 EDHF/NO 表达/功能的性别特异性功能障碍诱导高血压反应。为了检验这些假设，我们在建立的怀孕大鼠模型中提出了一系列实验并检查它们的后代。提出了三个具体目标：1）确定母体 T 升高是否会导致后代高血压（对男性的影响比女性更明显），以及出生后 T 升高是否先于高血压发作。我们将遥测监测血压 (BP) 的逐渐变化并测量 T 水平，以建立高血压的发病和严重程度与产后 T 水平变化之间的关系，从机制上确定产后 T 升高是否是血压升高的关键因素。 2）评估VSM中性别特异性高血压机制。我们将检查亚细胞组分中的 PKC 同工酶表达谱、其磷酸化状态和功能活性，并通过 ChiP 和报告分析评估 T 与 PKC 启动子中推定 ARE 的结合来检查雄激素调节 PKC 表达的机制。 3）剖析内皮功能受损的性别特异性机制。我们将检查 EDHF 和 NO 介导的通路，并通过确定 EDHF 成分 SK3 和 IK1 通道和连接蛋白（CX37、CX40 和 CX47）的 mRNA 和蛋白水平及其亚细胞定位来评估 EDHF 介导的血管舒张受损的机制。使用血管反应性和膜电位研究的功能活动。我们将通过评估 eNOS 的表达、其活性、NO 产生和信号事件来研究 NO 介导的血管舒张功能受损的作用。我们预计，子宫内 T 暴露将通过不同血管 PKC 同工酶的上调和男性和女性脉管系统中不同的内皮功能障碍而导致性别特异性高血压效应，这可能通过出生后 T 水平的变化来调节。这些结果将为理解成人心血管功能障碍的胎儿编程提供新的分子基础，并提高我们对血管功能障碍性别差异的认识，为设计预防和治疗高血压的性别特异性策略提供令人兴奋的机会。