Abstract P3045: MicroRNA-31-5p Is Upregulated During Neointima Formation And Promotes Smooth Muscle Cell Proliferation And Migration By Regulating Krüppel-like Factor 4 (KLF4)

Abstract

In the context of CVDs, microRNAs (miRs) have emerged as potential therapeutic targets for preventing adverse vascular remodeling and restenosis, given their ability to modulate multiple signaling pathways and cellular processes. Here, we propose that targeting miR-31-5p might be an effective approach to enhance vascular healing and regeneration in a cell-specific manner, thereby limiting angioplasty-related complications. A screening of murine neointimal tissue for differentially regulated miRs revealed robustly increased expression levels of miR-31-5p over time. Subsequently, expression levels of miR-31-5p were confirmed by qRT-PCR in human coronary artery endothelial cells (EC) and -smooth muscle cells (SMC). Further, the effect of miR-31-5p on cellular function was investigated and possible targets were identified and confirmed on mRNA and protein level. Expression analysis revealed a significant upregulation of miR-31-5p (p<0.0001) in C57BL/6J mice following wire-induced injury of the femoral artery at 7 and 21 days. In vitro, miR-31-5p was significantly upregulated in SMC (p<0,05 ) following serum stimulation, whereas only a slightly enhanced expression was observed in EC. On a functional level, miR-31-5p revealed dissenting effects on EC and SMC: Migration and proliferation were not altered in EC (p>0.05). In contrast, knockdown of miR-31-5p significantly reduced the migration (p<0,05) and proliferation in SMC (p<0,01) without detectable apoptotic effects. Systematic in silico target screens suggested KLF4 as potential target. Knock down of miR-31-5p resulted in a significant upregulation of KLF4 in SMC (p<0,01), whereas overexpression resulted in a significant downregulation of KLF4 in SMC (p<0,05) on mRNA- and protein level. Here, we report that miR-31-5p is robustly upregulated during neointima formation and seems to exert a functional role in SMC rather than EC since knockdown of miR-31-5p was able to prevent SMC proliferation and migration. Mechanistically, KLF4 identified as a direct target of miR-31-5p can mediate the observed effects. Thus, miR-31-5p might represent an attractive target to selectively modulate SMC dysfunction following vascular intervention, limiting neointima formation in treated vessels.