Ortiz-Melo David I, Gurley Susan B
Division of Nephrology, Department of Medicine Duke University and Durham VA Medical Centers, Durham, North Carolina, USA.
Curr Opin Nephrol Hypertens. 2016 Jan;25(1):59-66. doi: 10.1097/MNH.0000000000000182.
Angiotensin-converting enzyme 2 (ACE2) is a monocarboxypeptidase that metabolizes angiotensin II (AngII). AngII levels can be modulated by ACE2 in tissues where the enzyme is highly expressed, such as the kidney. In the kidney, ACE2 has the potential to regulate the intrarenal renin-angiotensin system (RAS), which can impact blood pressure and renal injury. Thus, in disease states where the RAS is often upregulated, the function of ACE2 plays a particularly important role. This review highlights the results of recent studies that demonstrate the interplay between ACE2 and the kidney under normal and pathological conditions.
ACE2 has been reported to play a key role in renal and cardiovascular function. Recent studies have implicated shedding of the membrane-bound ectodomain of ACE2 as one way in which the enzyme can be regulated and enzymatic activity altered. This posttranslational modification releases a fragment which retains enzymatic activity, and thus provides a novel mechanism by which the RAS can be altered in response to physiological stimuli. Decreased ACE2 activity is associated with increased blood pressure, diabetes, and oxidative stress, whereas, increased levels of ACE2 appear to be renoprotective.
A growing body of evidence, involving both experimental and human studies, points out the crucial role that ACE2 plays on the modulation of renal injury. Thus, therapeutic targets aiming to increase ACE2 activity and the ACE2-Ang(1-7)-MasR axis could potentially become clinically relevant, especially in disease states where the renal RAS is upregulated.
血管紧张素转换酶2(ACE2)是一种单羧肽酶,可代谢血管紧张素II(AngII)。在该酶高表达的组织(如肾脏)中,AngII水平可由ACE2调节。在肾脏中,ACE2有调节肾内肾素-血管紧张素系统(RAS)的潜力,这会影响血压和肾损伤。因此,在RAS常上调的疾病状态下,ACE2的功能起着尤为重要的作用。本综述重点介绍了近期研究结果,这些研究证明了正常和病理条件下ACE2与肾脏之间的相互作用。
据报道,ACE2在肾脏和心血管功能中起关键作用。近期研究表明,ACE2膜结合胞外域的脱落是调节该酶及改变酶活性的一种方式。这种翻译后修饰会释放出一个保留酶活性的片段,从而提供了一种新机制,使RAS能够响应生理刺激而改变。ACE2活性降低与血压升高、糖尿病和氧化应激增加有关,而ACE2水平升高似乎具有肾脏保护作用。
越来越多的证据,包括实验研究和人体研究,都指出了ACE2在调节肾损伤方面的关键作用。因此,旨在提高ACE2活性以及ACE2-Ang(1-7)-MasR轴的治疗靶点可能具有临床相关性,尤其是在肾RAS上调的疾病状态下。