To enhance healing after a myocardial infarction (MI), a well-coordinated angiogenic response is crucial. Current therapeutic approaches are insufficient. MicroRNAs (miRs) have been identified as regulators of angiogenesis and offer a promising strategy to improve neovascularization following MI. In this study, we investigate miR-148a-3p as a new miRNA candidate with therapeutic potential to enhance neovascularization post-MI, particularly in the context of cellular senescence.
The expression levels of miR-148a-3p were measured in Human Coronary Artery Endothelial Cells (HCAECs) and murine tissue using qPCR analysis. The effects of miR-148a-3p on cellular functions (proliferation, migration, cell death) were examined after pre- or anti-miR transfection in both replicative and non-replicative senescent HCAECs. Target gene and protein expressions were evaluated by qPCR and Western Blotting.
Initial screenings indicated that miR-148a-3p expression was upregulated in murine aortic endothelial cells of C57BL/6 mice (ages 3 vs. 24 months, p<0.05) and in a wire-induced vascular injury model (p<0.001). A similar effect was observed in vitro in senescent HCAECs (p<0.01), particularly under hypoxic conditions (p<0.05). Under growth conditions, miR-148a-3p levels were reduced compared to starvation, indicating a negative correlation with proliferation (p<0.05). Accordingly, downregulating miR-148a-3p improved proliferation in both non-senescent and senescent cells (p<0.01, p<0.001) and enhanced migration in senescent HCAECs (p<0.05). Systemic target research identified Akt1, NFKBIA, and RTN4 as potential targets, which were significantly upregulated following miR-148a-3p downregulation (p<0.001, p<0.01, p<0.05). The knockdown of miR-148a-3p reduced the expression of senescence markers such as p16ink4a, p21, p14arf, and CD44 (p<0.05). Immunofluorescence microscopy showed decreased nuclei size by anti-miR transfection as well as reduced b-galactosidase positive cells.
Our findings demonstrate that inhibiting miR-148a-3p enhances cellular functions, particularly in replicative senescent cells, strongly indicating that miRNA-148a-3p is involved in the angiogenic response and may serve as a therapeutic target. Future experiments will evaluate its potential in vivo using ultrasound-guided MI induction in mice.
