Abstract

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Martin-Luther-Universität Halle-Wittenberg Background and Purpose The accumulation of senescent cells in the vasculature contributes to impaired vascular function over the lifetime. Micro RNAs (miRs) are promising therapeutic targets due to their cell-specific functions. Targeting miR-127-3p emerges as an attractive approach to enhance vascular healing and limit angioplasty-related complications. Here, we focus on elucidating the role of miR-127-3p in vascular smooth muscle cells (VSMC) to characterize their role in cellular function and vascular senescence. Methods Utilizing reverse transcription and qRT-PCR we checked expression levels of miR-127-3p in human and murine aortic VSMCs. After overexpression and downregulation via transfection of pre-miR and antagomiR, we evaluated the influence of miR-127-3p on cellular functions such as proliferation and migration of human (non-) replicative senescent VSMCs. Potential targets were selected via target prediction analysis and verified on mRNA and protein levels. Morphological changes were visualized via high-resolution fluorescence microscopy. Senescence marker expression was checked after transfection by qRT-PCR. Results MiR-127-3p is highly upregulated in femoral artery tissue on day 10 after wire-induced injury in C57Bl6 mice, serving as restenosis model (p<0.001) and aged C57BL/6 mice (3 months vs. 22 months, p<0.0001). Replicative senescent human VSMC exhibit increased miR-127-3p expression (p<0.05). In vitro, miR-127-3p overexpression reduces proliferation in senescent (p<0.001) and non-senescent (p<0.01) cells. It hinders migration in non-senescent cells (p<0.0001) but has a reverse effect in senescent cells (p<0.01). Potential targets affecting cellular functions, inflammatory pathways, and cellular aging were identified as mTOR, AXL, and TEAD3 (p<0.05). Transfection of pre-miR leads to increase in cell size and the acquisition of a flattened morphology of human VSMC. P14arf and laminB1, as senescence-associated genes, showed downregulation after overexpression of miR-127-3p on mRNA level (p<0.05). When VSMCs were stimulated with anti-miR-127-3p, increased mRNA levels of p14arf and laminB1 were detected (p<0.05). Conclusion This study identifies miR-127-3p as a contributor to cellular functions including cellular proliferation and migration and seems to have opposing effects in non- and replicative senescent VSMC. Further research is needed to validate miR-127-3p as a therapeutic target for vascular aging and remodeling in vitro and in vivo.