EXTRACELLULAR VESICLES FROM HUMAN HEART EXPLANT-DERIVED CELLS ATTENUATE ACTIVATION OF THE NLRP3 INFLAMMASOME IN MACROPHAGES

BackgroundIntramyocardial injection of heart explant-derived cells (EDCs) improves cardiac function in preclinical models ischemic cardiomyopathy. This therapeutic benefit is partially attributable to the anti-inflammatory cargo (micro RNAs and proteins) enriched within extracellular vesicles (EVs) released by EDCs. Recent work has shown that activation NLRP3 (NOD-, LRR- pyrin domain-containing protein 3) inflammasome both immune non-immune plays a critical role promoting inflammation adverse remodeling. Although EDC EVs are known modulate inflammatory mediators, their effects on not known. Therefore, we explored ability attenuate macrophages, major pro-inflammatory cell type recruited myocardium after an insult.Methods ResultsEVs were isolated from conditioned media (ultracentrifugation) characterized (Nanosight & antibody array). Monocytes (THP-1) differentiated into macrophages (PMA; 3 days) treated with (20 hours) before priming (LPS; 4 activating (nigericin; 1 hour) inflammasome. Secreted caspase-1 culture supernatants was measured using bioluminescent assay (Promega). The miRNA profiled detection (Nanostring) liquid chromatography-mass spectrometry, respectively. data analyzed appropriate bioinformatics tools (Tam 2.0, miRWalk, Uniprot). EV size (160±2 nm) markers (ICAM, ALIX, CD81, CD63, EPCAM, ANXAS, TSG101, FLOT-1) confirmed identity. Macrophages pretreated (4E+10 EVs/mL) showed significant attenuation induced vs. LPS+nigericin-only (50% lower, n=4-6, p=0.02). profiling revealed 22 distinct miRNAs 2.0). Specifically, (miR-21, miR-100, miR-181a, n=3) 5 proteins (Peroxiredoxin-1, Thioredoxin-1, Caveolin-1, Sequestosome-1, abundantly found predicted inhibit (miRWalk Uniprot).ConclusionEDC suppress via transfer proteins. insult. Intramyocardial Methods ConclusionEDC