RNY-derived small RNAs as a signature of coronary artery disease

Abstract

BackgroundData from next generation sequencing technologies uncovered the existence of many classes of small RNAs. Recent studies reported that small RNAs are released by cells and can be detected in the blood. In this report, we aimed to discover the occurrence of novel circulating small RNAs in coronary artery disease (CAD).MethodsWe used high-throughput sequencing of small RNAs from human and mouse apoptotic primary macrophages, and analyzed the data by empirical Bayes moderated t-statistics to assess differential expression and the Benjamini and Hochberg method to control the false discovery rate. Results were then confirmed by Northern blot and RT-qPCR in foam cells and in two animal models for atherosclerosis, namely ApoE−/− and Ldlr−/− mouse lines. Quantitative RT-PCR to detect identified small RNAs, the RNY-derived small RNAs, was performed using sera of 263 patients with CAD compared to 514 matched healthy controls; the Student t-test was applied to statistically assess differences. Associations of small RNAs with clinical characteristics and biological markers were tested using Spearman’s rank correlations, while multivariate logistic regressions were performed to test the statistical association of small RNA levels with CAD.ResultsHere, we report that, in macrophages stimulated with pro-apoptotic or pro-atherogenic stimuli, the Ro-associated non-coding RNAs, called RNYs or Y-RNAs, are processed into small RNAs (~24–34 nt) referred to as small-RNYs (s-RNYs), including s-RNY1-5p processed from RNY1. A significant upregulation of s-RNY expression was found in aortic arches and blood plasma from ApoE−/− and Ldlr−/− mice and in serum from CAD patients (P <0.001). Biostatistical analysis revealed a positive association of s-RNY1-5p with hs-CRP and ApoB levels; however, no statistical interaction was found between either of these two markers and s-RNY1-5p in relation to the CAD status. Levels of s-RNY1-5p were also independent from statin and fibrate therapies.ConclusionOur results position the s-RNY1-5p as a relevant novel independent diagnostic biomarker for atherosclerosis-related diseases. Measurement of circulating s-RNY expression would be a valuable companion diagnostic to monitor foam cell apoptosis during atherosclerosis pathogenesis and to evaluate patient’s responsiveness to future therapeutic strategies aiming to attenuate apoptosis in foam cells in advanced atherosclerotic lesions.Electronic supplementary materialThe online version of this article (doi:10.1186/s12916-015-0489-y) contains supplementary material, which is available to authorized users.

RNY (YRNA)-derived small RNAs regulate cell death and inflammation in monocytes/macrophages

“…Endothelial cells, which do not express TLR7 or s-RNYs when stimulated with oxLDL/Tg, 1 are not activated by extracellular s-RNYs (Supplementary Figure S5), confining to immune cells the extracellular role of s-RNYs during atherosclerosis pathogenesis.…”

“…1 RNYs are characterized by extensive base pairing of the 5' and 3' regions and by the association with the proteins Ro60 and La/SSB, which are often targeted by the immune system in several autoimmune diseases. 23 Although, the role of RNYs per se is still poorly understood, s-RNYs have been previously described in T cells stimulated with anti-FAS antibody, 23 in germ cells, and in acute lymphoblastic leukemia.…”

Y RNA derived small RNAs in Sjögren's syndrome: Candidate biomarkers?

“…High levels of YsRNA have been reported in blood circulation of patients and mice models with coronary artery disease (CAD). The source of YsRNA are foamy macrophages in aortic inflammatory sites and are an independent signature biomarker of CAD . Breast cancer patients also have higher levels of YsRNA fragments in circulation as compared to healthy controls.…”

“…The source of YsRNA are foamy macrophages in aortic inflammatory sites and are an independent signature biomarker of CAD. 22 Breast cancer patients also have higher levels of YsRNA fragments in circulation as compared to healthy controls. YsRNA levels are decreased during remission in these patients.…”

Valeur diagnostique des petits ARN dérivés des ARNY (ou RNY) dans les cardiopathies coronariennes

“…Plus pré-cisément, nous avons émis l'hypothèse selon laquelle de petits ARN spécifiques, dont l'expression est augmentée dans les macrophages soumis à un stimulus apoptotique, pourraient être utilisés en tant que biomarqueurs de la progression de la plaque nécrotique dans un contexte de CAD. En utilisant une approche de séquen-çage à haut débit, nous avons démon-tré que des ARN non-codants d'environ 110 nucléotides (nt) qui sont associés à la protéine Ro 4 , les RNY, sont clivés en de plus petits fragments de 24-34 nt dans les macrophages soumis à des traitements pro-apoptotiques ou pro-athérogènes [11]. Les RNY, aussi appelés ARNY, sont une ancienne classe de transcrits produits par de l'ARN polymérase III, dont la fonction n'est pas encore définie.…”