Circulating miR-421 Targeting Leucocytic Angiotensin Converting Enzyme 2 Is Elevated in Patients with Chronic Kidney Disease

Abstract

Background: Decreased levels of leucocytic angiotensin converting enzyme 2 (ACE2) relate to atherosclerosis in patients with chronic kidney disease (CKD). Recently, micro RNA 421 (miR-421) was found to target and down-regulate ACE2 in human cardiac myofibroblasts. In this study, we investigated the correlation between serum levels of miR-421 and ACE2 transcripts in circulating leukocytes of healthy individuals (NP), CKD (3–5) and haemodialysis (HD) patients. Furthermore, we tested the possible interaction between miR-421 and 3′-UTR of ACE2 under normal and uremic milieu. Methods: The levels of circulating miR-421, serum Ang1–7 and expression of leucocytic ACE2, ACE, MASR, AT1R and AT2R were investigated in 16 CKD3–5 (76 ± 10 years), 32 HD patients (65 ± 13 years) and 23 NP (51 ± 5 years) by employment of specific primers, TaqMan and competitive enzyme-linked immunosorbent assay assays. Interaction between miR-421 and ACE2–3′-UTR was investigated on THP-1 cells by employment of normal and uremic sera, reporter vectors and miR-421 inhibitor. Effects of uremic toxins indoxyl sulphate, p-cresol and p-cresyl sulphate on ACE2 and miR-421 levels were investigated in THP-1 monocytes. Results: The levels of serum miR-421 were significantly elevated, while Ang1–7 was significantly decreased in CKD3–5 and HD patients as compared with NP. Serum Ang1–7 correlated positively with leucocytic ACE2 (r² = 0.213, p < 0.001). We found a significant and inverse correlation between the levels of circulating miR-421 and the expression of leucocytic ACE2 (r² = 0.223, p < 0.0001). Further significant and positive correlations could be demonstrated between miR-421 and the transcripts of leucocytic AT1R (r² = 0.094, p < 0.05) or eGFR (r² = 0.231, p < 0.0001) or CRP (r² = 0.092, p < 0.01). We found no correlations between miR-421 and ACE or AT2R or MASR expression. Treatment with miR-421 or uremic serum led to noticeable decrease of reporter 3′UTR-ACE2. Anti-miR-421 treatment resulted in the up-regulation of ACE2 protein. All uremic toxins tested were able to significantly elevate miR-421 levels and decrease the monocytic ACE2 transcripts. Conclusions: Uremic patients show an enhanced expression of serum miR-421 as compared to healthy individuals. A strong association of circulating miR-421 with decreased transcripts of ACE2 may contribute to the low expression of the enzyme in leukocytes of CKD patients, further supporting the development of atherosclerotic events.

Angiotensin converting enzyme: A review on expression profile and its association with human disorders with special focus on SARS-CoV-2 infection

“…Circulating leukocytes A significant, inverse correlation between circulating miR-421serum level and the ACE2 expression in leucocytic was shown. Also, ACE2 upregulation following Anti-miR-421 treatment was reported [87] miR-1246 acute lung injury (ALI) LPS-exposed pulmonary microvascular endothelial cells (PMVECs) miR-1246 meditates LPS-induced pulmonary endothelial cell apoptosis in vitro and ALI in mouse models, by targeting ACE2. [88] miR-200c-3p Acute respiratory distress syndrome (ARDS)…”

ACE2 Nascence, trafficking, and SARS-CoV-2 pathogenesis: the saga continues

“…[ 96,103] miR-143 Downregulated miR-143 induced by aerobic exercise training was accompanied by increased ACE2 expression in hypertensive rats.…”

Immune Dysfunction in Uremia 2020

“…The increased ACE expression on monocytes of dialysis patients with CVD provides a link between monocytes and the activated RAS [108]. Of note, circulating miR-421 targeting leukocytic ACE2 are increased in CKD patients [109].…”