The knockdown of C/EBPβ reduced PRMT1 expression. (A) Control fibroblasts were transfected with either control siRNA (small interference [si]-Con) or C/EBPβ siRNA (si-C/EBPβ) alone or followed by stimulation with TGF-β (5 ng/ml) for 48 h. The effect of C/EBPβ suppression was verified on the expression of the following: C/EBPβ, PRMT1, and PGC-1α by Western blots. (B) C/EBPβ, PRMT1, or PGC-1α band density was measured (ImageJ software) and normalized to GAPDH (n = 3). (C) Asthmatic fibroblasts (n = 3) were transfected with either control siRNA (si-con) or C/EBPβ siRNA (si-C/EBPβ) for 48 h, and the protein expression for C/EBPβ and PRMT1 was detected by Western blots. (D) C/EBPβ, PRMT1, or PGC-1α band density was measured (ImageJ software) and normalized to GAPDH. Comparison of indicated groups (B) or si-con to si-C/EBPβ group (D) by Mann-Whitney U-test: *p < 0.05, **p < 0.01, ***p < 0.001.