Effect of YY1/HSF1/miR-214/THY1 axis on bleomycin-induced IPF in mice. To generate a IPF model, the mice were administrated with bleomycin dissolved in normal saline on the 1st, 5th, 8th, 11th and 15th days, and infected with lentivirus (LV-sh-NC, LV-sh-YY1, LV-sh-YY1 and LV-sh-THY1 in combination) on the 24th, 26th and 28th days. (A) The pathological changes in lung tissues in mice shown by HE staining and Masson staining, respectively (400×); (B) The amount of collagen in lung tissues shown by hydroxyproline (HYP) measurement using alkaline hydrolysis assay; (C) The expression of YY1, HSF1, miR-214 and THY1 in lung tissues of mice measured by RT-qPCR, and the expression of YY1, HSF1 and THY1 proteins measured by western blot assay; (D) The expression of COI, COIII and α-SMA in the lung tissues of mice measured by RT-qPCR and western blot assay. Statistical data were measurement data, and presented as mean ± standard deviation. Comparisons among multiple groups were analyzed by the one-way ANOVA with Tukey's post hoc test. *, p < 0.05 vs. control mice, #, p < 0.05 vs. bleomycin-treated mice injected with LV-sh-NC, &, p < 0.05 vs. bleomycin-treated mice injected with LV-sh-YY1, n = 8.