Figure 4

TNF-stimulating gene (TSG)-6 secreted by mesenchymal stem cells (MSCs) attenuated peritoneal adhesion. A. No TSG-6 expression by TSG-6- small interfering (si) RNA-MSCs in the lung at 4 hours after injection was observed on immunofluorescence microscopy. Red symbolizes red fluorescent protein (RFP); Green symbolizes TSG-6. Magnification: × 600, × 1800. B. Serum TSG-6 concentrations as evaluated by enzyme-linked immunosorbent assay (ELISA). No obvious increment of TSG-6 after TSG-6-siRNA-MSCs injection was detected compared with the medium-injected group. The concentration of TSG-6 in the TSG-6-siRNA-MSCs-injected group at 4 hours after injection was lower than that in the MSCs-injected group. Three independent samples were placed in three replicate wells. * compared with the medium-injected group, P <0.05; # compared with the normal group, P <0.05; & compared with the MSCs-injected group, P <0.05. C. The effects of TSG-6 on acute peritoneal adhesions. C1. The TSG-6-siRNA-MSCs-injected group exhibited no significant reduction in adhesion scores on day 14 after scraping but the recombinant mouse (rm) TSG-6-injected group exhibited an obvious reduction in peritoneal adhesion scores similar to the MSCs-injected group. * compared with the medium-injected group, P <0.05 (n = 6). C2. Histological changes were evaluated using Masson's trichrome staining. The TSG-6-siRNA-MSCs-injected group revealed no reduction in fibrosis in the scraped peritoneum 14 days after scraping. But the rmTSG-6-injected group revealed a distinct reduction in peritoneal fibrosis similar to the MSCs-injected group. Magnification: × 100, × 400. C3. The peritoneal fibrosis scores were not reduced by injecting TSG-6-siRNA-MSCs but by injecting rmTSG-6 or MSCs. * compared with the medium-injected group, P <0.05 (n = 6).