Figure 4.

dsDNA derived from pulmonary epithelial cells promoted the transformation of fibroblasts into myofibroblasts. (A) dsDNA content in the supernatant of irradiated MLE-12 cells was detected. (B) Comparison of the dsDNA content between the supernatants of MLE-12 cells and NIH/3T3 cells. (C) After NIH/3T3 cells were co-cultured with the MLE-12 cells’ supernatant, the expression levels of α-SMA and Collagen I in NIH/3T3 cells were detected. (D) The protein expression levels of α-SMA and Collagen I in NIH/3T3 cells after adding poly(dA:dT) were detected by western blot. The mRNA expression levels of fibrosis-related factors α-SMA (E), Fibronectin-1 (F), and ZEB1 (G) were measured by RT-qPCR after the addition of poly(dA:dT). (H) The expression level of α-SMA in NIH/3T3 cells after adding poly(dA:dT) was detected by immunofluorescence. Scale bar, 50 µm. Data are shown as mean ± standard deviation of triplicate measurements; n=6. *, P<0.05; **, P<0.01; ***, P<0.001. dsDNA, double-stranded DNA; NC, negative control; IR, irradiation; SN, supernatant; DAPI, 4',6-diamidino-2-phenylindole; RT-qPCR, reverse transcription quantitative polymerase chain reaction.