Figure 5

Pasteurella multocida activates pulmonary epithelial cell apoptosis via the FAK-AKT-FOXO1 axis. A Top ten RNA-seq enrichment pathways of cellular processes and signal transduction in murine lungs infected with 10⁴ CFU of PmCQ2 at 16 hpi. B Transcription of the integrin α family in the lungs of PmCQ2-infected mice, as determined by qPCR. N = 5. The data are presented as the means ± SDs. C Representative images of integrin αV expression in the in situ lungs of PmCQ2-infected mice at 16 hpi, as determined by immunohistochemistry. Scale bar = 100 μm. D Western blot analysis of integrin αV, p-Fak and Fak in the lungs of PmCQ2-infected mice. Each lane represents one individual. E Representative images of the expression of p-Akt in the in situ lungs of PmCQ2-infected mice at 16 hpi, as determined by immunohistochemistry. Scale bar = 100 μm. F Transcription of Foxo1 downstream genes in the lungs of PmCQ2-infected mice at 16 hpi, as determined by qPCR. Each group contained 5 replicates. The data are presented as the means ± SDs. G Western blot analysis of the FAK-AKT-FOXO1 pathway in the lungs of PmCQ2-infected mice and PmCQ6-infected mice at 16 hpi. Each lane represents one individual. H Western blot analysis of PmCQ2-infected TC-1 cells with or without shFoxo1 knockdown at 6 hpi. I Flow cytometry analysis of apoptosis in PmCQ2-infected TC-1 cells with or without shFoxo1 knockdown at 6 hpi. Each group contained 3 replicates. The data are presented as the means ± SDs. *p < 0.05, **p < 0.01, ***p < 0.001, N. S: not significant.