Targeting ACE2 ubiquitination for hypertension

在美国，55岁及以上人群的患病率高达55%，高血压是一个主要风险 导致心血管疾病(CVD)和全球死亡率的因素，因此仍是一个日益严重的问题 重要的医疗和公共卫生问题。肾素-血管紧张素系统(RAS)在维持性疾病中的作用 在正常血压(BP)和导致高血压的神经-心血管失调中 站稳了脚跟。血管紧张素(Ang)-II通过其1型受体(AT1R)促进交感神经增加 活动，盐和水的重吸收，血管收缩，醛固酮和加压素的释放和炎症， 所有这些都会导致高血压。血管紧张素转换酶2(ACE2)，最新发现的 这个系统的成员切割Ang-II，产生Ang-(1-7)，起到补偿作用，反对 RAS的有害影响。除了将血管紧张素转换酶2确立为预防神经源性心脏病的关键参与者之外 高血压，我们的研究小组首次报道血管紧张素转换酶II通过 AT1R激活，溶酶体抑制剂预处理可阻止这种作用。虽然已确认 独立小组，预防ACE2泛素化和降解的治疗潜力尚未得到 调查过了。我们的试点数据显示，ACE2 C末端的突变阻止了泛素化和 保留ACE2的代偿活性，而泛素化抗性ACE2病毒治疗钝化 血管紧张素转换酶II介导的高血压在缺乏血管紧张素转换酶2的小鼠中的发展。此外，我们还展示了 靶向E3泛素连接酶主要家族NEDD4中和Ang-II对ACE2的有害影响 活性，而一项试验性蛋白质组学分析强调了其他E3连接酶的性别特异性调节和去激活 盐敏感型高血压小鼠下丘脑中的泛素酶。我们的初步数据进一步 强调这种机制并不局限于AT1R，而是由炎症激活缓激肽B1R 与高血压相关的反应，也参与其中。因此，这项工作的假设是RAS超过- 激活和高血压相关炎症加剧ACE2泛素化，导致 这种酶的降解和其代偿活性的丧失，最终加剧了高血压。在这里，我们 将使用新的病毒方法和独特的转基因模型将ACE2泛素化作为目标，重点是 中枢神经系统和血管系统中不同性别和特定细胞的差异。验证我们的 假说将为旨在保护ACE2代偿活动的新靶向方法打开大门 高血压和心血管疾病。

With prevalence as high as 55% for individuals aged 55 and older in United States, hypertension is a major risk factor contributing to cardiovascular diseases (CVD) and global mortality, hence remaining an increasingly important medical and public health issue. The role of the renin-angiotensin system (RAS) in the maintenance of normal blood pressure (BP) and in the neuro-cardiovascular dysregulation leading to hypertension has been firmly established. Angiotensin (Ang)-II, by means of its type 1 receptor (AT1R), promotes increased sympathetic activity, salt and water reabsorption, vasoconstriction, aldosterone and vasopressin release and inflammation, all contributing to hypertension. Angiotensin Converting Enzyme type 2 (ACE2), one of the latest identified members of this system cleaves Ang-II and produces Ang-(1-7) which plays a compensatory role and opposes the RAS deleterious effects. Beyond establishing ACE2 as a critical player in the prevention of neurogenic hypertension, our group was the first to report that Ang-II mediates ACE2 ubiquitination and degradation via AT1R activation, effects that were prevented by pretreatment with a lysosomal inhibitor. Although confirmed by independent groups, the therapeutic potential of preventing ACE2 ubiquitination and degradation has not been investigated. Our pilot data, show that mutation of the C-terminus of ACE2 prevents the ubiquitination and preserves ACE2 compensatory activity while treatment with an ubiquitination-resistant ACE2 virus blunts the development of Ang-II-mediated hypertension in mice otherwise lacking ACE2. In addition, we show that targeting NEDD4, a major family of E3 ubiquitin ligases, neutralizes the deleterious effects of Ang-II on ACE2 activity, while a pilot proteomics analysis highlighted gender-specific modulation of other E3 ligases and de- ubiquitinases in the hypothalamus of mice undergoing salt-sensitive hypertension. Our preliminary data further highlight that this mechanism is not restricted to AT1R but that bradykinin B1R, activated by the inflammatory response associated to hypertension, are also involved. Thus, the hypothesis of this work is that RAS over- activation and hypertension-associated inflammation exacerbate ACE2 ubiquitination, resulting in enhanced degradation of this enzyme and a loss of its compensatory activity, ultimately reinforcing hypertension. Here, we will target ACE2 ubiquitination using novel viral approaches and unique transgenic models with an emphasis on gender- and cell-specific differences in the central nervous system and the vasculature. Validation of our hypothesis will open the door for new targeting approaches aimed at preserving ACE2 compensatory activity in hypertension and CVD.