Abstract P3046: The Effect Of MicroRNA-367-3p And MicroRNA-148a-3p On Vascular Endothelial Cells In Context Of Senescence And Infarct Healing

Abstract

To improve the healing after myocardial infarction (MI), a well-coordinated angiogenic response is necessary. MicroRNAs (miRNAs) were identified as regulators of angiogenesis, however, strategies to improve angiogenesis by targeting miRNAs are challenging. Here, we evaluate miRNA-367-3p and 148a-3p as novel miRNA candidates regarding their therapeutic potential toward neovascularization after MI. Following expression analysis of the respective miRNAs in human vascular endothelial cells (EC) and mice tissue, their contribution to EC function after either pre- or anti-miR transfection was assessed. Further, potential targets were identified and studied on mRNA and protein level. Initial screenings show that miRNA-148a-3p and miRNA-367-3p are differently expressed in both a restenosis model via wire-induced injury and aged mice tissue (p<0.05). Under growth conditions, miRNA-148a-3p expression was upregulated in ECs. In senescent ECs, miRNA-367-3p shows a significant 50-fold upregulation of its expression (p<0.01); miRNA-148a-3p is also overexpressed in senescent ECs (p<0.01). Hypoxia increases the effect observed in senescence (p<0.05). Downregulation of either miRNA-367-3p or miRNA 148a-3p leads to an improvement in migration capacity (p<0.0001) and proliferation of ECs (p<0.0001). Systematic target research in silico identified DKK3 as potential target of miRNA-367-3p and DDX6 as potential target of miRNA-148a-3p. Downregulation of either miRNA-148a-3p or miRNA-367-3p verified these predictions by significantly upregulating DKK3 respectively DDX6. In further experiments, we study the dysfunctional effect of miRNA-148a-3p on vascular endothelial cells by targeting DDX6 as well as the anti-angiogenic impact of miRNA-367-3p by targeting DKK3. Summarizing different expression levels of miRNA-367-3p and miRNA-148a-3p exerted distinct effects on EC function, especially in senescent cells and under hypoxic conditions. Our experimental data regarding cellular function show that these miRNAs are involved in the angiogenetic response and hold the potential to serve as therapeutic targets. In future experiments, we will evaluate the miRNA potential on MI healing in vivo.