Human monocyte subsets exhibit divergent angiotensin I-converting activity

Abstract

SummaryImmune cells may take part in the renin-angiotensin-aldosterone system (RAAS), which plays a pivotal role in the regulation of vascular tone and blood pressure. The aim of the study was to analyse the expression and activity of angiotensin-converting enzyme type 1 (ACE1) and ACE2 in human monocytes (MO) and their subsets. The highest relative level of ACE1-, as well as ACE2-mRNA expression, was observed in CD14 11 CD16 2 (classical) MO. Moreover, in these cells, mean level of ACE2-mRNA was almost two times higher than that of ACE1-mRNA (11.48 versus 7.073 relative units, respectively). In peripheral blood mononuclear cells (PBMC), MO and classical MO, ACE1 and ACE2 protein expression was stronger compared to other MO subpopulations. The highest level of Ang II generated from Ang I in vitro was observed in classical MO. In this setting, generation of Ang-(1-9) by PBMC and classical MO was higher when compared to the whole MO population (P < 0Á05). The generation rate of vasoprotective Ang-(1-7) was comparable in all analysed cell populations. However, in CD14 1 CD16 11(non-classical) MO, formation of Ang-(1-7) was significantly greater than Ang II (P < 0Á001). We suggest that in physiological conditions MO (but also lymphocytes forming the rest of PBMC pool) may be involved in the regulation of vessel wall homeostasis via the RAAS-related mechanisms. Moreover, non-classical MO, which are associated preferentially with the vascular endothelium, express the vasoprotective phenotype.

Counter-regulatory renin–angiotensin system in cardiovascular disease

“…In line with these observations, the pro inflammatory state is thought to upregulate RAS signal ling in the setting of hypertension 108 . Interestingly, human monocytes also express ACE and ACE2 and can produce angiotensin 1-7 and angiotensin 1-9 109 . Taken together, these data suggest that the immune system might also be involved in regulating the non canonical RAS.…”

Angiotensin-Converting Enzyme Gene Deletion Polymorphism is Associated with Lymph Node Metastasis in Colorectal Cancer Patients in a Chinese Population

“…ACE enzyme can catalyze the conversion of angiotensin I into angiotensin II, which is a potent vasoconstrictor influencing cancer progression [ 23 ]. A number of studies have reported that the mRNA and protein levels of ACE in tumor cells or tissues were different from that in normal cells or tissues [ 24 – 26 ]. Abnormal expression level of ACE gene leads to aberrant levels of angiotensin II, thus influencing tumor progression, and ACE can promote angiogenesis [ 27 ].…”

A blood-based comprehensive and systems-level analysis of disease stages, immune regulation and symptoms in COVID-19 patients

“…We next analyzed the expression patterns of genes associated with coronavirus infection in PBMCs in acute-like and recovering-like using SARS-CoV-infected patients and healthy volunteers (from training data). We compared the expression of ACE2, IL6, and TNF genes in PBMC from infected patients and healthy individuals, which are known to be expressed in circulating monocytes and macrophages after viral infection (28,29) , (30). Although there was increased expression of ACE2 and IL6 in acute-like patients compared to healthy individuals, there was no significant differences between acute-like and recovering-like patients ( Figure 2A-B).…”