Functional screening identifies miRNAs with a novel function inhibiting vascular smooth muscle cell proliferation

Area of Science:

• Vascular Biology and Regenerative Medicine
• Molecular Therapeutics
• Gene Regulation

Background:

• Vascular smooth muscle cell (vSMC) proliferation drives pathological vascular remodeling.
• MicroRNAs (miRNAs) are key gene regulators with therapeutic potential.
• Targeting vSMC proliferation is crucial for treating vascular diseases.

Purpose of the Study:

• To systematically identify and characterize miRNAs that inhibit vSMC proliferation.
• To explore the therapeutic potential of identified miRNAs for vascular remodeling, particularly in vein graft failure.
• To investigate the molecular mechanisms underlying miRNA-mediated vSMC growth inhibition.

Main Methods:

• High-throughput screening of 2,042 human miRNA mimics to assess their impact on vSMC proliferation.
• Evaluation of miRNA effects on vSMCs from different vascular beds and human saphenous vein smooth muscle cells (HSVSMCs).
• Transcriptomic analysis of HSVSMCs and ex vivo vein organ models to elucidate miRNA targets and mechanisms.

Main Results:

• Seven miRNAs (miR-323a-3p, miR-449b-5p, miR-491-3p, miR-892b, miR-1827, miR-4774-3p, miR-5681b) demonstrated novel anti-proliferative effects on vSMCs.
• These miRNAs reduced HSVSMC proliferation without toxicity and downregulated a common cell-cycle gene network.
• Overexpression of miR-323a-3p and miR-449b-5p inhibited medial proliferation in an ex vivo vein organ model.

Conclusions:

• Seven novel miRNAs possess significant therapeutic potential for targeting pathological vSMC proliferation.
• These miRNAs offer a promising strategy for mitigating vascular remodeling and improving outcomes in conditions like vein graft failure.
• The findings provide a foundation for developing miRNA-based therapies for vascular diseases.