Abstract
Oxidative stress plays a fundamental role in many conditions. Specifically, redox imbalance inhibits endothelial cell (EC) growth, inducing cell death and senescence. We used global transcriptome profiling to investigate the involvement of noncoding-RNAs in these phenotypes. By RNA-sequencing, transcriptome changes were analyzed in human ECs exposed to H2O2, highlighting a pivotal role of p53-signaling. Bioinformatic analysis and validation in p53-silenced ECs, identified several p53-targets among both mRNAs and long noncoding-RNAs (lncRNAs), including MALAT1 and NEAT1. Among microRNAs (miRNAs), miR-192-5p was the most induced by H2O2 treatment, in a p53-dependent manner. Down-modulated mRNA-targets of miR-192-5p were involved in cell cycle, DNA repair and stress response. Accordingly, miR-192-5p overexpression significantly decreased EC proliferation, inducing cell death. A central role of the p53-pathway was also confirmed by the analysis of differential exon usage: Upon H2O2 treatment, the expression of p53-dependent 5′-isoforms of MDM2 and PVT1 increased selectively. The transcriptomic alterations identified in H2O2-treated ECs were also observed in other physiological and pathological conditions where redox control plays a fundamental role, such as ECs undergoing replicative senescence, skeletal muscles of critical limb-ischemia patients and the peripheral-blood mononuclear cells of long-living individuals. Collectively, these findings indicate a prominent role of noncoding-RNAs in oxidative stress response.
Highlights
Redox homeostasis plays a fundamental role in endothelial cell (EC) function and its imbalance elicits oxidative stress that has a causative role in many vascular diseases [1, 2]
Given the importance of p53 for mRNA modulation by oxidative stress highlighted by the gene ontology analysis (Fig. 1), we investigated whether the same was true for long noncoding‐RNAs (lncRNAs)
H2O2 concentration used in this study induced a strong cytostatic effect and very low EC death in vitro, in keeping with previous studies [18, 19, 41,42,43,44,45,46,47,48]
Summary
Redox homeostasis plays a fundamental role in endothelial cell (EC) function and its imbalance elicits oxidative stress that has a causative role in many vascular diseases [1, 2]. Several hubs of cell response to oxidative stress have been identified, such as NRF2 and FOXO1, that increase the antioxidant defenses, and NFkB, that induces the transcription of pro-inflammatory cytokines [3, 4]. Another pivotal player is p53: it is activated by a multitude of stress stimuli, including reactive oxygen species, and, in turn, orchestrates an extremely complex anti-proliferative and pro-apoptotic transcriptional program [5]
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