Exosomes Secreted from CXCR4 Overexpressing Mesenchymal Stem Cells Promote Cardioprotection via Akt Signaling Pathway following Myocardial Infarction

Figure 1

Characterization of MSC-derived exosomes. (a) Transmission electron microscopy (TEM) micrograph of exosomes purified from MSC. Isolated exosomes showed spherical and membrane encapsulated with the diameters varying between 40 and 90 nm. (b) Representative dynamic light scattering (DLS) number distribution measurement of isolated exosome population demonstrates a single peak (~90 nm diameter) indicating they are free of contamination. (c) Expression of specific exosomal markers, CD9 and CD63, in exosomes was identified by Western blotting. , exosomes isolated from MSC transfected with null lentivirus (); , exosomes isolated from MSC transfected with lentivirus overexpressing CXCR4 (); , exosomes isolated from MSC transfected with lentivirus siRNA against CXCR4 gene (); Exo + GW4860, exosomes isolated from MSC with additional sphingomyelinase inhibitor GW4860. (d) Uptake of exosomes by neonatal cardiomyocytes (CM). CM were stained by cardiac specific antibody, sarcomeric α-actinin (red). -derived exosomes were labeled with PKH67 (green) and incubated with CM for 48 hr.

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