Figure 4. POPDC2+ and CHRNE+ Cardiovesicles from Human Plasma Demonstrate Cardiac-Specific Gene Expression Profiles.

a. Transmission Electron Microscopy images of POPDC2+ (blue arrows) and CHRNE+ (gold arrows) EVs in healthy human plasma, displaying both single positive (POPDC2+ CHRNE-; POPDC2- CHRNE+) and double positive (POPDC2+ CHRNE+) EVs, with gold particle sizing for POPDC2 (5 mm) and CHRNE (12 mm). b. Cardiovesicles exhibiting POPDC2+ and CHRNE+ signatures are visualized and quantified using Fluorescent-Microfluidic Resistive Pulse Sensing (F-MRPS) in plasma EVs (n=3 replicates). c. Detailed overview of the ExoCapture-MSB Method for immunocapture of cardiovesicles from 500 μL of Human Plasma, employing Pierce^™ Streptavidin Magnetic Beads with biotin-streptavidin affinity. Western Blot analysis of POPDC2 (d) and CHRNE (e) immunocapture, highlighting enrichment for cardiomyocyte-specific protein Troponin. Transcriptomic enrichment of cardiac-specific transcripts, prioritized by tau score ≥ 0.9, in vesicles immunocaptured with Biotinylated POPDC2 (f) and CHRNE (g) antibody, respectively. with the expression of the bulk CD81 immunocaptured vesicles (Input) on the x-axis and the expression of the immunocaptured Cardiovesicles on the y-axis (Enriched). h. Box plots showing the expression of heart enriched genes (TNNI3, LRRC10, MYL4, BMP10, FBXO40) in vesicles immunocaptured with CD81, POPDC2, and CHRNE antibodies, confirming specific capture and analysis of Cardiovesicles. i. UMAP visualization from single nuclear RNA sequencing depicting plots (TNNI3, LRRC10, MYL4, BMP10, FBXO40) as highly cardiac-enriched transcripts within Cardiovesicles, affirming their cardiac origin. P<0.05 is utilized as the threshold of statistical significance. N= 3 replicates.