Figure 8

Important role of TLR9 pathway in necrotic cell-induced pulmonary inflammation. (A) Wild-type C57BL/6 mice and Tlr9^−/−, MyD88^−/−, IL-1R1^−/−, Tlr3^−/−, Tlr4^−/−, Tlr5^−/− mice were treated with mtDNA (5 μg/mouse) for 24 h and HE staining of lung sections was performed. Scale bar, 50 μm. (B) DOTAP liposomes (25 mg/kg), PEI (5 mg/kg), Chitosan (25 mg/kg) or mtDNA (5 μg/mouse) with ODN2088 or with ODN Control (50 μg/mouse) were injected into normal C57BL/6 mice. HE staining of mouse lung sections 24 h after injection is shown. Scale bar, 50 μm. (C) Positive cells in esterase staining of neutrophils were counted in ten HPFs. (D) Neutophils were treated with mtDNA (DNA, 5 μg/ml) or mtDNA and ODN2088 (ODN, 25 μg/ml) for 2 h. MMP-8 release and activation of p38 MAPK was examined by immunoblot in supernatants and cell pellets, respectively. The relative intensities of proteins were determined and shown in bar graphs. (E) Wild-type C57BL/6 mice and Tlr9^−/− mice were injected with DOTAP liposomes (100 mg/kg) through tail veins every 24 h for 2 days and mouse survival were recorded every 24 h, n = 10. Data are mean ± SEM; n = 3.^***P< 0.001 by Student's t-test.