T Lymphocyte-Derived Exosomes Transport MEK1/2 and ERK1/2 and Induce NOX4-Dependent Oxidative Stress in Cardiac Microvascular Endothelial Cells

Figure 4

CD4-exosomes activate ERK1/2 and MEK1/2 pathway in cMVECs. Panel (a) shows changes at mRNA levels in cMVECs stimulated with CD4-exosomes for up to 6 hours, , for NOX4 and P22, for other genes. Changes in protein levels of NOX2, NOX4, ERK1/2, ERK1/2 phosphorylation (pERK1/2), MEK1/2 and MEK1/2 phosphorylation (pMEK1/2), phosphorylation sites in cMVECs stimulated with CD4-exosomes for 16 h, and representative immunoblots are shown in panel (b), . Protein levels were normalized to beta-tubulin, and phosphorylated proteins were additionally normalized to their respective nonphosphorylated forms. Immunoblots of lysates (equal amounts of proteins were loaded on gel) from activated T lymphocytes (CD4) and CD4-exosomes (CD4 Exo) for indicated proteins are shown in panel (c). Panel (d) shows representative microphotographs demonstrating binding of PKH26-stained CD4-exosomes (red fluorescence) to MVECs 16 h after treatment. . , , and calculated by one-way ANOVA followed by Fisher’s LSD post hoc test versus control group.

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