Fig 2: BCL 6 mediates RIPF via miR-486-3p/Snail Axis. A Mice were divided into four groups: Normal (Nor), irradiated alone (IR), irradiated after lung administration (AAV + NC, IR + NC), irradiated after lung administration (AAV + mimic, IR + mimic). B miR-486-3p levels in irradiated mouse lung tissue (n = 5) at different time using qRT-PCR. C, D H&E staining (n = 5) and the score of lung tissue, scale bar, 100 µm. E Masson’s staining (n = 5) and the Relative content quantitation of Collagen. G Alterations of pulmonary fibrosis-related protein levels in lung tissue after 4 months of irradiation. On the right, the bar graph shows the gray value analysis. H Changes in transcription factor BCL6 and target proteins in different groups after irradiation. I Snail expression in lung tissues by immunohistochemical experiment. J Quantitative analysis of IHC (n=5). *p < 0.05 compared with Normal; #p < 0.05 compared with IR + NC

Fig 3: Working model of EMT induction by IR-activated transcription factor BCL6 via miR-486-3p/Snail.BCL6 was activated and increased after IR, and binding to the promoter region of miR-486-3p inhibited the transcription of miR-486-3p, resulting in a decrease in pri-miR-486-3p content. pri-miR-486-3p reduction led to a decrease in miR-486-3p content and weakened the silencing effect of miR-486-3p on Snail. Thus, the above figure describes a complete Radiation-induced pulmonary fibrosis through the BCL6/miR-486-3p/Snail axis

Fig 4: BCL6 regulates CD36 expression.A Relative mRNA and (B) protein levels of RXR, PXR, LXRa, LXRß, and PPAR? in the LO2 cells stimulated with PA (0.3 mM) for 24 h after transfected with Ad-Control or Ad-BCL6 for 48 h. n = 3 in each group. C Relative mRNA levels and (D) protein of RXR, PXR, LXRa, LXRß, and PPAR? in the LO2 cells stimulated with PA (0.3 mM) for 24 h after transfected with Ad-Scr sh (as a control) or Ad-BCL6 sh for 48 h. n = 3 in each group. E Relative luciferase activity of CD36 promoters of different lengths in primary hepatocytes of mice after BCL6 overexpression or not. F Relative luciferase activity of CD36 promoters after mutation of different sites in primary hepatocytes of mice after BCL6 overexpression or not. G Quantitative ChIP was performed in the LO2 cells using antibodies for BCL6 or IgG control to enrich for possible BCL6 binding sites in the CD36 loci. The y axis represents fold enrichment of binding versus input, as compared with IgG control. H Pearson r and P values for normalized BCL6 mRNA levels versus normalized CD36 mRNA levels in human livers (n = 243). Data represent the mean ± SEM, *P < 0.05, **P < 0.01, ***P < 0.001 and n.s. indicates no significance between the two indicated groups.

Fig 5: BCL6 knockout aggravates HFD-induced hepatic steatosis.A Schematic image of the generation of a liver-specific BCL6-CKO mouse (BCL6-CKO) strain. B Mouse genotyping was confirmed by PCR. C Protein expression of BCL6 in the liver of flox and CKO mice. D Bodyweight, (E) liver weight, (F) LW/BW, and (G) food intake of the BCL6-CKO and BCL6-flox mice at 16 weeks post-HFD administration (n = 6/group). H Representative images of H&E (upper) and oil red O (bottom) staining of liver tissues from the BCL6-CKO and BCL6-flox mice fed an HFD for 16 weeks. Scale bar, 100 µm. I Total cholesterol, J triglyceride, K NEFA, and L ALT and M AST levels in the livers from the BCL6-CKO and BCL6-flox mice fed an HFD for 16 weeks. (n = 6/group). N Representative images of immunohistochemistry staining of F4/80 and Sirian red staining of liver tissues from two group mice. Scale bar, 100 µm. Hepatic mRNA levels of (O) IL-6 and TNFa, (P) COL1a1and aSMA from two group mice fed an HFD for 16 weeks (n = 6/group). Data represent the mean ± SEM, *P < 0.05, **P < 0.01, ***P < 0.001 and N.S. indicates no significance between the two indicated groups.