Central role of the p53 pathway in the noncoding-RNA response to oxidative stress.

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 HO, 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 HO 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 HO treatment, the expression of p53-dependent 5'-isoforms of MDM2 and PVT1 increased selectively. The transcriptomic alterations identified in HO-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.