Figure 4.
Importance of Circulating Adiponectin for the Cardioprotective Effects of hMSCs
(A) Experimental design for adenovirus Gaussia luciferase (Ad-gLuc)-MFG-E8-infected hMSCs. Infected hMSCs were injected i.v. at 5.0 × 105 cells per body into adiponectin knockout (AKO) and wild-type (WT) mice via the tail vein. Blood was collected at 4, 8, 24, 48, and 72 h. Plasma exosomes were precipitated by Exo Quick and ultracentrifugation, as described in Materials and Methods. (B) gLuc activity of plasma exosome was analyzed using a luminometer. The area under the curve (AUC) was calculated (n = 3–4). (C–H) hMSCs were injected i.v. at a concentration of 5.0 × 105 cells per body via the tail vein in the transverse aortic constriction (TAC) model in AKO and WT mice. (C) Experimental design for hMSC delivery into the TAC model. The injection was repeated six times at 2- to 3-day intervals within a period of 2 weeks. Echocardiography was performed at day 14. (D) Serum exosomes were subjected to western blot analysis with the indicated antibodies of exosome markers. (E) Exosome marker levels from western blots (n = 3–4). (F) Heart weight per tibia length ratio (n = 3–10). (G) Representative images of echocardiography. (H) Ejection fraction (EF) and fractional shortening (FS) estimated at 2 weeks after TAC or sham surgery (n = 3–6). Data are mean ± SEM. The experiments were tested in two separate trials. ∗p < 0.05; ∗∗p < 0.01; ∗∗∗p < 0.001 versus sham. †p < 0.05; ††p < 0.01; †††p < 0.001 between groups, by one-way analysis of variance with post hoc Tukey’s multiple comparisons.