Fig. 5.

Intravenous injection of ceramide-enriched exosomes isolated from stressed mice or ceramide-loaded exosomes inhibits PLD and reduces phosphatidic acid in the hippocampus. A and C Wild-type mice were left untreated (-) or stressed with glucocorticosterone (GC) or chronic unpredictable stress (CUS) and exosomes were isolated. Purified exosomes were treated ex vivo with ceramide IgM antibodies clone S58-9 (anti-Cer), control immunoglobulin M (ctrl IgM), or recombinant ceramidase (CDase) or were left untreated (-), pelleted by ultracentifugation, resuspended in H/S, and injected intravenously (i.v.) into healthy wild-type mice. Control mice (Ctrl) were completely left untreated (-). PLD activity A and phosphatidic acid concentrations C in the hippocampus were determined 12 h after i.v. injection of exosomes. B and D Exosomes were purified from the blood plasma of untreated mice, loaded with C22, C24, and C24:1 ceramide in the amounts and ratio as these ceramide species are present in exosomes isolated from glucocorticosterone (GC)-treated mice or in exosomes isolated from mice treated with chronic unpredictable stress (CUS), washed and then i.v. injected into untreated wildtype mice. PLD activity B and phosphatidic acid concentrations D in the hippocampus were determined 12 h after i.v. injection of exosomes. Shown are the mean ± SD from each 6 animals or experiments/group. ***P < 0.001, ANOVA and post hoc Tukey test