The renin angiotensin system (RAS) is composed of several enzymes and substrates on which angiotensin converting enzyme (ACE) 1 and renin act to produce angiotensin II. ACE1 and its substrates control blood pressure, affect cardiovascular and renal function, hematopoiesis, reproduction, and immunity. The increased expression of ACE1 has been observed in human monocytes during congestive heart failure and abdominal aortic aneurysm. Moreover, T lymphocytes from hypertensive patients presented increased expression of ACE1 gene after in vitro stimulation with Angiotensin-II (AngII) with the highest ACE1 expression observed in hypertensive patients with low-grade inflammation. Our group and others have shown that aging is associated with comorbidities, chronic inflammation and immunosenescence, but there is a lack of data about ACE1 expression on immune cells during the aging process. Therefore, our aim was to evaluate the levels of ACE1 expression in non-lymphoid as compared to lymphoid cells in association with the immunosenescence profile in adults older than 60 years. Cryopreserved peripheral blood mononuclear cells obtained from blood samples were used. Cells were stained with monoclonal antibodies and evaluated by flow cytometry. We found that ACE1 was expressed in 56.9% of non-lymphocytes and in more than 90% of lymphocytes (all phenotypes). All donors exhibited characteristics of immunosenescence, as evaluated by low frequencies of Naive CD4+ and CD8+ T cells, high frequencies of EMRA CD8+ T cells, and double-negative memory B cells. These findings in addition to the increased C-reactive protein levels are intriguing questions for the study of ACE1, inflammaging, immunosenescence and perspectives for drug development or repurposing.

中文翻译：

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血管紧张素转换酶 (ACE) 1 在 64 至 67 岁成人白细胞中的表达

肾素血管紧张素系统 (RAS) 由多种酶和底物组成，血管紧张素转化酶 (ACE) 1 和肾素在这些酶和底物上起作用以产生血管紧张素 II。ACE1及其底物控制血压，影响心血管和肾功能、造血、生殖和免疫。在充血性心力衰竭和腹主动脉瘤期间，已在人单核细胞中观察到 ACE1 的表达增加。此外，在用血管紧张素-II (AngII) 体外刺激后，来自高血压患者的 T 淋巴细胞表现出 ACE1 基因的表达增加，其中在患有低度炎症的高血压患者中观察到最高的 ACE1 表达。我们的小组和其他人已经表明，衰老与合并症、慢性炎症和免疫衰老有关，但缺乏关于衰老过程中免疫细胞ACE1表达的数据。因此，我们的目的是评估与 60 岁以上成年人的免疫衰老谱相关的非淋巴细胞与淋巴细胞中 ACE1 的表达水平。使用从血液样品中获得的冷冻保存的外周血单核细胞。细胞用单克隆抗体染色并通过流式细胞术进行评估。我们发现 ACE1 在 56.9% 的非淋巴细胞和超过 90% 的淋巴细胞（所有表型）中表达。所有供体都表现出免疫衰老的特征，如低频率的幼稚 CD4+ 和 CD8+ T 细胞、高频率的 EMRA CD8+ T 细胞和双阴性记忆 B 细胞所评估。