Phenotypically changed and senescent vascular smooth muscle cells (VSMC) contribute to the progression of vascular diseases such as atherosclerosis. Micro RNAs (miRs) are promising therapeutic targets due to their cell-specific functions. Targeting miR-127-3p emerges as an attractive approach to counteract vascular remodeling.
This study focuses on elucidating the role of miR-127-3p in VSMC focusing on cellular functions to reveal insights into plaque progression.
Utilizing reverse transcription and qRT-PCR we checked expression levels of miR-127-3p in human and murine VSMCs. Through pre-miR transfection followed by qRT-PCR, different functional assays, and fluorescence microscopy, we examined the impact of miR-127-3p overexpression on cellular senescence and cellular functions. Potential targets were selected via target prediction analysis and verified on mRNA and protein levels.
MiR-127-3p expression is downregulated in the aorta of ApoE-/- mice (**** p<0.0001). However, it is highly upregulated in aged C57BL/6J mice (3 months vs. 22 months, p<0.0001). Upregulation of miR-127-3p expression was also observed in femoral artery tissue on day 10 after wire-induced injury in C57BL/6J mice, serving as a restenosis model (p<0.001). In vitro, replicative senescent VSMCs exhibit increased miR-127-3p expression (p<0.05). Expression of miR-127-3p was also increased after IFNƴ stimulation in non-senescent VSMCs (p<0.05).
MiR-127-3p overexpression reduces proliferation in replicative senescent (p<0.001) and non-senescent (p<0.01) VSMCs. It hinders migration in non-senescent VSMCs (p<0.0001) but has a reverse effect in replicative senescent VSMCs (p<0.01). Production of reactive oxygen species is increased in non-senescent VSMCs after overexpression of miR-127-3p (p<0.5), whereas there was no effect on replicative senescent VSMCs.
Senescence marker LaminB1 showed a decreased expression after overexpression of miR-127-3p on mRNA level (p<0.05) in non-senescent and replicative senescent VSMCs. In non-senescent cells IL-6 (p<0.05) and IL-1ß (p<0.05) showed an increased expression, other cytokines showed a similar tendency. However, SMTN (p<0.05) expression was also increased after miR-127-3p overexpression.
Pre-miR transfection did not lead to significant differences in size of cell nuclei, ß-Galactosidase activity, and telomere length neither in non-senescent nor in replicative senescent VSMCs.
Targets of miR-127-3p, including mTor, were identified on mRNA and protein level. On mRNA level mTor was downregulated in non-senescent and replicative senescent VSMCs (p<0.05). In non-senescent VSMCs expression of Phospho-mTor (p<0.05) was upregulated on protein level after pre-miR transfection.
The study provides compelling evidence that miR-127-3p plays a role in the phenotypical switch of VSMCs and significantly influences cellular functions such as proliferation, migration, and the production of reactive oxygen species. The results indicate that miR-127-3p is a key contributor to the progression of vascular diseases and suggest that targeting miR-127-3p could be an effective approach for counteracting vascular remodeling. However, the study also emphasizes the need for further research to validate miR-127-3p as a potential therapeutic target for vascular remodeling in both in vitro and in vivo settings.
