Extracellular vesicle isolation and characterization in patients undergoing catheter-based valve intervention

Abstract

Record ID: 258

Mentorship Award: Excellence in Research Mentoring

Type: Poster Presentation (in-person)

Advisor: Donald Lynch

Abstract: Valvular heart disease (VHD) is a leading cause of morbidity and mortality among the aging population. Over the last 14 years, percutaneous minimally invasive heart surgeries with catheter-based techniques have become increasingly available as options for treatment of patients with symptomatic severe VHD. Our lab has recently demonstrated inflammation driven by dynamic platelet transcriptomic alterations following catheter intervention which may impact outcomes. Pathway analysis demonstrated an enrichment in genes involved in endosomes, which control traffic of proteins inside a cell, and exosomes, which are extracellular vesicles (EVs) released from the cell that carry proteins. The objective of this study is to profile EVs in plasma following minimally invasive procedures, such as transcatheter valve interventions (TVI). EVs were isolated from stored plasma samples from patients who underwent transcatheter aortic valve replacement (TAVR) or transcatheter mitral valve repair with the Mitraclip. We compared isolation of EVs using ultracentrifugation (EC) and size exclusion chromatography (SEC) and characterization was performed using Nanoparticle tracking analysis along with Nanoflow cytometry. Isolation of EVs using with SEC recovered more EVs than UC from plasma cells. Among patients undergoing Mitraclip, there were significantly lower levels of CD63+ and CD41+ EV antigens (P < 0.05) post-procedure. However, there were no significant differences noted in plasma EVs following TAVR. Our study demonstrated lower levels of plasma EVs among patients undergoing Mitraclip than TAVR, which may indicate dysfunctional exosome release and may be a potential new therapeutic target.