Dual microRNA blockade increases expression of antioxidant protective proteins; implications for ischaemia reperfusion injury

BACKGROUND: MicroRNAs (miRNA) are short noncoding RNAs which each cause repression of many target genes. Previous work has demonstrated that therapeutic blockade of single microRNAs is possible. miR-24-3p and miR-145-5p are reported to have a detrimental role in ischaemia reperfusion injury (IRI). As the action of miRNAs is inhibitory, we hypothesised that dual blockade of both miRNAs could synergistically upregulate shared target genes. METHODS: Quantification of miRNA expression in donated kidneys was performed using PCR panels. IRI was modelled in vitro by placing Human Umbilical Vein Endothelial Cells (HUVECs) into a hypoxic incubator (1% O2) for 24hrs, with reoxygenation for 6hrs. RNA expression was quantified with RT-qPCR and protein expression assessed with Western blot. Antisense oligonucleotides (ASOs) were used to inhibit miRNAs. RESULTS: miR-24-3p and miR-145-5p were highly expressed in human kidneys following extended cold ischemia. In vitro, hypoxia caused significant upregulation of miR-24-3p (p