[Functional role of protein kinase D1 in Aspergillus fumigatus-induced activation of nuclear factor-κB signal pathway and transcription].

OBJECTIVE: To explore the functional role of protein kinase D1 (PKD1) in the activation of nuclear factor-κB (NF-κB) signal pathway and NF-κB transcription mediated by Aspergillus fumigatus. METHODS: A549 cells and HEK293 cells were transfected with green fluorescence protein (GFP) or GFP-PKD1 followed by treatment with 1×10(5) CFU/ml Aspergillus fumigatus conidia for different time lengths. The phosphorylation levels of PKD1, IκB and p65 (pS276) in the transfected cells were measured by Western blotting. A549 cells were transfected with GFP-PKD1 or siRNA-PKD1, and the phosphorylation of IκB and p65 (pS276) was examined. Finally, NF-κB-luc and renilla luciferase reporter pRL-SV40 were cotransfected into GFP- or GFP-PKD1-transfected A549 cells before exposure of the cells to Aspergillus fumigatus conidia for 24 h, and NF-κB transcriptional activity in the cells was determined using dual-luciferase reporter assay. RESULTS: Overexpression of PKD1 significantly increased Aspergillus fumigatus conidia-stimulated phosphorylation of PKD1, IκB and p65 (pS276), whereas PKD1 knockdown by siRNA-PKD1 suppressed IκB and p65 (pS276) phosphorylation. Dual luciferase assay demonstrated that PKD1 overexpression markedly enhanced Aspergillus fumigatus-induced NF-κB transcription in A549 cells. CONCLUSION: PKD1 may contribute to the activation of NF-κB signal pathway and NF-κB transcription induced by Aspergillus fumigatus.