Poster T19 - Utilizing nanoparticles that selectively target inflamed endothelium for upregulating intimal macrophage-like cell ABCA1 via endothelial cell-derived exosome-mediated processes.

Introduction: Atherosclerosis is the result of lipid accumulating within endothelial cells (EC) and underlying intimal cells. Atherosclerosis does not normally occur throughout all arteries, but usually forms within arteries that are highly inflamed, making inflamed endothelium a unique target for novel atheroprotective therapeutics. The two types of intimal cells which largely contribute to atherosclerosis are lipid-laden macrophages and vascular smooth muscle cells (VSMC) that have converted into macrophage-like cells (MLC) due to excessive cholesterol accumulation via a process called trans-differentiation. Recently, our laboratory developed an innovative nanoparticle-based therapy that can precisely target inflamed EC. Since our constructed nanoparticles carry plasmid DNA that expresses XMOTIF-tagged anti-miR-33a-5p, inflamed EC which internalize these nanoparticles may package anti-miR-33a-5p into exosomes that are secreted basolaterally, thus allowing the delivery of atheroprotective anti-miR-33a-5p into intimal cells.

Materials and

Methods: We tested our delivery system in vitro to show basolaterally secreted, inflamed EC-derived exosomes filled with anti-miR-33a-5p are capable of increasing ATP-Binding Cassette Transporter A1 (ABCA1)-dependent cholesterol efflux in macrophages, as the microRNA miR-33a-5p silences ABCA1 (Echesabal-Chen CIMB 2023;45:5631-5644). However, since emerging data suggests the majority of lipid-laden intimal cells are MLC of VSMC origin, we also wanted to analyze whether our therapeutic model can cause atheroprotective effects in MLC. We utilized MOVAS cells, which is a VSMC line we have shown trans-differentiates into MLC when cholesterol-loaded (Esobi Lipids 2021;56:413-422). We exposed MOVAS MLC cells to anti-miR-33a-5p-filled exosomes released basolaterally by inflamed EC in vitro.

Results, Conclusions, and Discussions: Our results show exposed MOVAS MLC to anti-miR-33a-5p-filled exosomes upregulates ABCA1 expression in comparison to that of the control. Future studies are underway to assess if this result also increases ABCA1-dependent cholesterol efflux in MOVAS MLC. The delivery of a plasmid DNA system with lipoparticles that encapsulate anti-miR-33a-5p to inflamed endothelial cells might be an option atherosclerosis protective study.

Acknowledgements (Optional): Funding Sources:
NIH/NHLBI AREA Award 1R15HL152261-01A1
NIH/NIGMS SC BioCRAFT Pilot Project P30GM131959
USDA-NIFA, Hatch Project SC-1700577; Accession no. 1021291

References:

Echesabal-Chen J, Huang K, Vojtech L, Oladosu O, Esobi I, Sachdeva R, Vyavahare N, Jo H, Stamatikos A. Constructing Lipoparticles Capable of Endothelial Cell-Derived Exosome-Mediated Delivery of Anti-miR-33a-5p to Cultured Macrophages. Curr Issues Mol Biol. 2023;45:5631-5644. (PMID: 37504271)

Esobi IC, Barksdale C, Heard-Tate C, Reigers Powell R, Bruce TF, Stamatikos A. MOVAS Cells: A Versatile Cell Line for Studying Vascular Smooth Muscle Cell Cholesterol Metabolism. Lipids. 2021;56:413-422. (PMID: 33881166)