Chronic Kidney Disease-Associated Atherosclerosis is Attenuated by Dual Inhibition of microRNA-92a and microRNA-489

Chronic kidney disease (CKD) subjects have an increased risk of developing cardiovascular disease, namely atherosclerosis. Endothelial dysfunction and inflammation are linked to the development of these diseases and recent work has identified a number of microRNAs (miRNAs) involved in these pathologies. As such, endothelial miRNAs are potential novel therapeutic targets to prevent and treat atherosclerosis. This study identified elevated aortic endothelial miR-92a-3p and miR-489-3p levels in a mouse model of CKD-associated atherosclerosis, Apoe -/- mice with 5/6 nephrectomy. A combinatorial miRNA inhibition strategy resulted in the loss of both miR-92a-3p and miR-489-3p in the endothelium and significantly reduced the atherosclerotic lesion area by 33%. Total RNA sequencing of the aortic endothelium identified many altered genetic pathways and metabolic processes in response to in vivo miRNA loss-of-function, including inflammation, phospholipid metabolism, and protein degradation pathways. Results suggest that the reduction in atherosclerosis levels were not likely to be linked to alterations in plasma cholesterol levels or kidney function since these physiological parameters were not improved upon miRNA inhibition. Nevertheless, novel miRNA targets were identified to be significantly elevated in the aortic endothelium that may reduce inflammation leading to the improved physiological phenotype. Fam220a , a negative regulator of signal transducer and activator of transcription 3 (STAT3) phosphorylation, mRNA levels were significantly reduced in CKD-atherogenic mice compared to controls, but miRNA inhibition in vivo blocked the Fam220a repression. Moreover, gene reporter (luciferase) assays with site-directed mutagenesis confirmed FAM220A as a direct target of miR-92a-3p. Furthermore, FAM220A mRNA levels were repressed in human coronary artery endothelial cells (HCAEC) with miR-92a-3p over-expression, which resulted in increased phosphorylation of STAT3. Collectively, these results suggest that endothelial miR-92a-3p and miR-489-3p are novel therapeutic targets to treat CKD-associated atherosclerosis.