Elgazzaz Mona, Lakkappa Navya, Berdasco Clara, Mohan Uma Priya, Nuzzo Anna, Restivo Luke, Martinez Alexa, Scarborough Amy, Guidry Jessie J, Sriramula Srinivas, Xu Jiaxi, Daoud Hisham, Mendiola Plá Michelle A, Bowles Dawn E, Beyer Andreas M, Mauvais-Jarvis Franck, Yue Xinping, Filipeanu Catalin M, Lazartigues Eric
Cardiovascular Center of Excellence (M.E., N.L., C.B., U.P.M., A.N., L.R., A.M., A.S., J.J.G., S.S., J.X., X.Y., C.M.F., E.L.), New Orleans, LA.
Departments of Pharmacology & Experimental Therapeutics (M.E., N.L., C.B., U.P.M., J.J.G., S.S., J.X., X.Y., E.L.), New Orleans, LA.
Hypertension. 2025 Jan;82(1):84-95. doi: 10.1161/HYPERTENSIONAHA.124.23196. Epub 2024 Nov 27.
Ang-II (angiotensin II) impairs the function of the antihypertensive enzyme ACE2 (angiotensin-converting enzyme 2) by promoting its internalization, ubiquitination, and degradation, thus contributing to hypertension. However, few ACE2 ubiquitination partners have been identified, and their role in hypertension remains unknown.
Proteomics and bioinformatic analyses were used to identify ACE2 ubiquitination partners in the brain, heart, and kidney of hypertensive C57BL6/J mice of both sexes. The interaction between UBR1 (ubiquitin protein ligase E3 component N-recognin) and ACE2 was validated in cells. Central and peripheral UBR1 knockdown was then performed in male mice to investigate its role in the maintenance of hypertension.
Proteomics analysis of the hypothalamus identified UBR1 as a potential E3 (ubiquitin protein ligase) ligase promoting ACE2 ubiquitination. Enhanced UBR1 expression, associated with ACE2 reduction, was confirmed in various tissues from hypertensive male mice and human samples. Treatment of endothelial and smooth muscle cells with testosterone, but not 17β-estradiol, confirmed a sex-specific regulation of UBR1. In vivo silencing of UBR1 using chronic administration of small interference RNA resulted in the restoration of ACE2 levels in hypertensive male mice. A transient decrease in blood pressure after intracerebroventricular, but not systemic, infusion was also observed. Interestingly, UBR1 knockdown increased brain activation of Nedd4-2 (neural precursor cell expressed developmentally downregulated protein 4), an E3 ligase promoting ACE2 ubiquitination, and reduced expression of serum and glucocorticoid-regulated kinase 1, the kinase that inactivates Nedd4-2.
These data demonstrate that UBR1 is a novel E3 ubiquitin ligase targeting ACE2 in hypertension. UBR1 and Nedd4-2 appear to work synergistically to ubiquitinate ACE2. Targeting these ubiquitin ligases may represent a novel strategy to restore ACE2 compensatory activity in hypertension.
血管紧张素II（Ang-II）通过促进降压酶血管紧张素转换酶2（ACE2）的内化、泛素化和降解来损害其功能，从而导致高血压。然而，很少有ACE2泛素化伴侣被鉴定出来，它们在高血压中的作用仍然未知。
采用蛋白质组学和生物信息学分析来鉴定雄性和雌性高血压C57BL6/J小鼠脑、心脏和肾脏中的ACE2泛素化伴侣。在细胞中验证了泛素蛋白连接酶E3组分N-识别蛋白1（UBR1）与ACE2之间的相互作用。然后在雄性小鼠中进行中枢和外周UBR1基因敲低，以研究其在维持高血压中的作用。
下丘脑的蛋白质组学分析确定UBR1是一种促进ACE2泛素化的潜在E3（泛素蛋白连接酶）连接酶。在高血压雄性小鼠的各种组织和人类样本中证实了与ACE2减少相关的UBR1表达增强。用睾酮而非17β-雌二醇处理内皮细胞和平滑肌细胞，证实了UBR1的性别特异性调节。使用慢性给予小干扰RNA在体内沉默UBR1导致高血压雄性小鼠中ACE2水平恢复。脑室内注射（而非全身注射）后血压短暂下降也被观察到。有趣的是，UBR1基因敲低增加了促进ACE2泛素化的E3连接酶神经前体细胞表达的发育下调蛋白4（Nedd4-2）的脑内活性，并降低了使Nedd4-2失活的激酶血清和糖皮质激素调节激酶1的表达。
这些数据表明UBR1是高血压中靶向ACE2的一种新型E3泛素连接酶。UBR1和Nedd4-2似乎协同作用使ACE2泛素化。靶向这些泛素连接酶可能代表一种恢复高血压中ACE2代偿活性的新策略。
