Heydarkhan-Hagvall, S. | bioRxiv Science

bioRxiv2025

Targeted delivery of mRNA to the heart via extracellular vesicles or lipid nanoparticles

Targeted mRNA transport plays a crucial role in enhancing the therapeutic efficacy of the molecule, reducing its side effects, and minimizing off-target effects. Systemic administration of mRNA through lipid nanoparticles (LNPs) or extracellular vesicles (EVs) predominantly results in mRNA accumulation in the liver. We hypothesized that cardiac-specific EVs could more effectively target the transport of mRNA to the heart, in comparison to non-cardiac-specific EVs or LNPs. In mice, after intravenous administration, EVs from cardiac progenitor cells (CPC-EVs) were the most efficient to transport the modified mRNA, encoding vascular endothelial growth factor A (VEGF-A), to mouse heart, with minimal liver accumulation compared to non-cardiac-specific EVs or LNPs. Additionally, intracardiac injections of CPC-EVs not only demonstrate that they are the most adapted vehicle for interacting with heart tissue, delivering the mRNA to cells, and inducing maximal VEGF-A protein production, but RNA-seq analyses also revealed their minimal impact on overall gene expression, compared to LNPs or non-cardiac-specific EVs. Furthermore, immunofluorescence staining of CD31 and -SMA, markers of microvascular density, showed increased vessel density in mouse aortic rings following the delivery of VEGF-A mRNA via CPC-EVs. These findings suggest that CPC-EVs are superior in mRNA targeting to heart, communication with cardiac cells, and causing minimal transcriptomic changes during VEGF-A mRNA delivery. Therefore, CPC-EVs could be promising vectors for heart-targeted mRNA delivery, potentially reducing liver accumulation.

molecular biology↗

bioRxiv2023

Mouse Model of Heart Attack and Stroke Shows Improved Survival with MPO Inhibition

Thromboembolic events, including myocardial infarction (MI) or stroke, caused by the rupture or erosion of unstable atherosclerotic plaques are the leading cause of death worldwide1. Unfortunately, the lack of a mouse model that develops advanced coronary atherosclerosis and that exhibits a high incidence of spontaneous plaque rupture with MI or stroke has greatly stymied development of more effective therapeutic approaches for reducing these events beyond what has been achieved with aggressive lipid lowering. Herein, we describe a novel mouse model that develops widespread advanced atherosclerosis including in coronary, brachiocephalic, and carotid arteries. These mice show high mortality following Western Diet feeding with clear evidence of plaque rupture, MI, and stroke. To validate the utility of this model, mice were treated with the drug candidate AZM198, which inhibits myeloperoxidase, an enzyme primarily produced by activated neutrophils and predictive of rupture of human atherosclerotic lesions2-7. AZM198 treatment resulted in marked improvements in survival with a greater than 60% decrease in the incidence of plaque rupture, MI, and stroke. In summary, our work describes a novel mouse model that closely replicates late-stage clinical events of advanced human atherosclerotic disease and evidence that this model can be used to identify and test potential new therapeutic agents to prevent major adverse cardiac events.

physiology↗