Fig. 7

Comparison of the activation of macrophage and the expression of TLR-4 of the left lung in rats with PF. Left lung sections were obtained from the Normal, BLM, BLM + Nintedanib, BLM + Pirfenidone, and BLM + HUMSCs groups on day 49 and were subjected to immunohistochemical stain with anti-ED1 antibody for macrophage labeling. From low to high magnifications, the number of macrophages with a relatively small morphology increased in the BLM group. Transplantation of HUMSCs triggered the activation of macrophage with a relatively bigger size. The patterns of macrophages were similar between the rest treatment groups and the BLM group (a, b). Next, anti-CD86 antibody was applied to label M1 macrophage, which revealed that the number of M1 macrophages increased in the left lungs of the BLM, BLM + Nintedanib, and BLM + Pirfenidone groups (c, e). Additionally, anti-CD163 antibody was used to mark M2 macrophage, which showed that the number of M2 macrophages elevated in the left lung of the BLM, BLM + Nintedanib, and BLM + Pirfenidone groups; the number of M2 macrophages significantly increased in the BLM + HUMSCs group (d, f). Moreover, the expression level of MMP-9 (g) and TLR-4 (h) in the left lung was quantified with Western blotting, results showed that transplantation of HUMSCs resulted in alternative macrophage activation and increased MMP-9 and TLR-4 expressions in the left lung of rats with PF. n = 3 in each group. ✽: vs the Normal group, p < 0.05. ♦: vs the BLM + HUMSCs group, p < 0.05