Figure 4

Implantation of hMSCs reduced mouse pro-inflammatory gene profiles and favored the M2-type alternative activating microglial/Mϕ (AAM) environment. Mouse cytokine gene expressions were determined in spinal cords after injury. hMSC-treated wild-type (wild) mice (black) manifested suppressed levels of mouse proinflammatory cytokines gene expression such as IL-1β (Il1b; (A)) and TNFα (Tnf; (B)) compared with HBSS-treated mice (white). The cell treatment also decreased IL-10 (Il10; (C)) and TGFβ (Tgfb1; (D)) levels. However, hMSC-treated wild-type mice exhibited increased levels of gene expression for anti-inflammatory cytokine such as IL-4 (Il4; (E)). For Il1b, Tnf, Tgfb1, and Il4, these were diminished in hMSC-treated Adcyap1 ^+/− (PA^+/−) mice (gray) 7 days after SCI. Cont means intact spinal cord in wild-type mice. Data show mean ± SE (n = 8). *P < 0.05, **P < 0.01, ***P < 0.001 (Tukey post hoc test). Injection of hMSCs significantly increased arginase activity 7 days after SCI (F). Data show mean ± SE (n = 7). *P < 0.05 (Student’s t-test). HBSS Hank’s balanced salt solution, MSC mesenchymal stem/stromal cell, n.s. no significant, PA ^+/− Adcyap1 (PACAP gene) heterozygous mice.