RNAi targeting multiple cell adhesion molecules reduces immune cell recruitment and vascular inflammation after...

Area of Science:

• Cardiovascular Biology
• Immunology
• Nanomedicine

Background:

• Myocardial infarction (MI) triggers systemic vascular inflammation, leading to severe complications and mortality.
• Increased sympathetic tone post-MI exacerbates leukocyte production and adhesion molecule expression in atherosclerotic plaques.
• Leukocyte recruitment into plaques and ischemic myocardium contributes to secondary damage.

Purpose of the Study:

• To develop and evaluate a nanoparticle-based RNA interference (RNAi) strategy to simultaneously silence key adhesion molecules involved in post-MI inflammation.
• To assess the efficacy of multigene silencing in reducing leukocyte infiltration and protease activity in atherosclerotic lesions and ischemic myocardium.

Main Methods:

• Development of endothelial-avid nanoparticles co-encapsulating small interfering RNA (siRNA) targeting ICAM1, ICAM2, VCAM1, E-selectin, and P-selectin.
• Administration of nanoparticles to ApoE(-/-) mice subjected to coronary ligation (MI model).
• Quantification of leukocyte recruitment (neutrophils, monocytes) into atherosclerotic plaques and myocardium, and measurement of plaque protease activity.

Main Results:

• Nanoparticle-mediated RNAi effectively silenced the targeted five adhesion molecules.
• Reduced recruitment of neutrophils and monocytes into atherosclerotic lesions and the ischemic myocardium post-MI.
• Decreased matrix-degrading plaque protease activity observed in treated mice.

Conclusions:

• Targeted multigene silencing of adhesion molecules using nanoparticle-based RNAi is a promising strategy to mitigate post-MI vascular inflammation.
• This approach effectively reduces leukocyte infiltration and may prevent secondary ischemic complications after acute myocardial infarction.