Figure 5.

Silencing ubiquitin (Ub) with small interfering RNA (siRNA) inhibited inflammatory responses. A, Interaction between phosphorylated IκBα and Ub was significantly decreased after Klebsiella pneumoniae infection after knock-down of Ub. Cells were transfected with Ub siRNA. At 24 hours after transfection, cells from the murine alveolar macrophage cell line (MH-S) were infected with K. pneumoniae for 2 hours and then collected for the coimmunoprecipitation assay. B, Silencing Ub followed by K. pneumoniae infection decreased the expressions of tumor necrosis factor (TNF) α. MH-S cells were transfected with Ub siRNA. After 24 hours, the cells were infected with K. pneumoniae for 2 hours. Data were representative of 3 experiments. *P < .05 (1-way analysis of variance and Bonferroni selected multiple comparison test). Abbreviations: +, with; −, without; GAPDH, glyceraldehyde 3-phosphate dehydrogenase; IB, immunoblotting; IP, immunoprecipitation.