(A) A western blotting analysis of key exosomal proteins. Trophoblastic
EXs were mainly recovered in the three fractions (see Methods for details),
which were immuno-reactive to CD63 and syntenin-1. In contrast, Ago2 protein was
only present at the bottom fractions, but absent in the fractions corresponding
to trophoblastic EXs. (B) Analysis of trophoblastic EVs using NTA. Note that the
X-axis indicates the particle size distribution, and the Y-axis denotes particle
concentration. (C) Electron microscopy (EM) images of trophoblastic EVs. EM
scale bar: 100 nm. (D) A western blotting analysis of exosomal proteins TSG101
and syntenin-1, compared to PHT cells. Calnexin is a marker of endoplasmic
reticulum membranes. An equal amount of total proteins in PHT cells and
PHT-derived exosomes were loaded. All the isolation and characterization
experiments were performed at least three times.