miRNA in BMDC-derived immature and mature exosomes. (A) Western blot analysis (top) of 1-mL density fractions from a continuous sucrose gradient used to purify BMDC exosomes. Exosomes, detected by their CD9 expression, were enriched in those fractions with characteristic exosome density. The digital gel (bottom), obtained with Agilent 2100 Bioanalyzer, shows the presence of miRNAs in the density fractions in which exosomes were present. One of 2 experiments is shown. (B) Digital gel (Agilent 2100 Bioanalyzer) showing the presence of similar levels of miRNAs isolated from exosomes treated (or not) with proteinase K and then incubated (or not) with RNase A. Results are representative of 2 independent experiments. (C) Analysis of miRNAs from BMDC exosomes showing intensity of expression of miRNAs against their rank position. Signals above the 2500 cutoff were considered positive. (D) Venn diagram with the numbers of miRNAs detected in immature and mature exosomes released by BMDCs. List with the miRNAs detected by Illumina miRNA Expression Array. In those cases were the probe did not resolve miRNAs differing at only 1 or 2 positions, miRNAs were listed in parentheses. Results are based on the miRNA profiling of 4 different samples of each type of exosomes.