Fig. 4
Therapeutic Effects of MSC EV Primed HMW HA in Mice Injured with PA103 Bacterial Pneumonia. a Intravenous administration of MSC EV significantly decreased PA103 CFU levels in the BALF and blood when compared with injured mice. Treatment of HMW HA (1.0 MDa) primed MSC EV further reduced the PA103 CFU levels in the BALF and blood compared with MSC EV treated mice. Data are median with IQR, *P < 0.01, **P < 0.01, ****P < 0.0001 by Kruskal-Wallis test with Dunn’s correction, N = 6–20. Individual P values describe the statistical comparison between the two groups by Mann-Whitney U test. b Administration of MSC EV primed with or without HMW HA (1.0 MDa) both significantly reduced TNFα and IL-6 levels in the BALF and plasma in mice injured with severe PA pneumonia compared with injured mice. Compared to MSC EV, HMW HA (1.0 MDa) primed MSC EV further decreased TNFα and IL-6 levels in the BALF and plasma. Data are as mean ± SD, *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001 by ANOVA (Bonferroni), N = 5–15. Individual P values describe the statistical comparison between the two groups by Student’s t test. A dose of MSC EV (90 μl) was used = 2.0 × 1010 particles