Klebsiella pneumoniae Is Able to Trigger Epithelial-Mesenchymal Transition Process in Cultured Airway Epithelial Cells
Fig 3
Evaluation of the intracellular ROS generation and the expression of antioxidant genes due to K. pneumoniae infection of A549 cells at lower MOI.
(A) The assessment of intracellular ROS generation by cytofluorimetric analysis shows the modulation of intracellular ROS induced by K. pneumoniae infection. The ROS overproduction is related to MOI (ANOVA post test for linear trend: *p<0.05; Dunnett’s test: **p>0.05 or ***p>0.01 vs uninfected cells). The representative flow cytometry plots at MOI 25:1 show an enhancement of DCFH-DA signal in A549 Kp-infected (flat green) respect to uninfected cells (brilliant green). (B) The confocal quantitative analysis of intracellular DCFH-DA fluorescent signal confirms the overproduction of ROS species in A549 Kp-infected cells (Student T test: *p<0.0001). In the representative digital images, the differences in the levels of DCFH-DA signal were expresses in a pseudo-color scale of fluorescence intensity, in which white is the highest and brown-red is the lowest intensity value of gray scale levels. Legend: MFI: Mean Fluorescence Intensity; FIU: Fluorescence Intensity Units. (C) SOD-1, SOD-2 and catalase mRNA levels were evaluated by real time RT-PCR in Kp-infected cells at MOI 1:25 and normalized respect to uninfected A549 cells. Results are expressed as mean ± SD. (Mann-Whitney test: *p<0.01 or ^p = not significant vs A549 uninfected cells).