Fig. 2.

EVs from patients with SM exhibit a mast cell signature. (A) Western blot analysis of EVs isolated from 100 µL of serum from the indicated subjects showing the presence of characteristic receptors for mast cells (KIT, FcεRI-α and -γ subunits, and MRGX2) and mast cell tryptase. Isolated EVs were resuspended in 100 µL of RIPA lysis buffer and equal volumes loaded onto SDS/PAGE gels. CD9 and CD63, common EV markers, are also shown. (B) Western blot analysis of EVs lysates where equal total protein amounts were loaded. Protein content in EV lysates was determined using a BCA protein assay. Equal protein content is demonstrated by the similar band intensities of CD9 and CD63. The histograms represent the average band fluorescence intensities within each group (and in B, normalized to the average of CD9 and CD63 intensities) and expressed as fold changes compared with the average band intensity in the HV-EV group. Of note, endothelin A and B receptors were not detected in SM-EV. **P < 0.01.