Journal: Frontiers in Pharmacology
Article Title: BRG1 exacerbates myocardial fibrosis after myocardial infarction by interacting with ZEB1
doi: 10.3389/fphar.2026.1802700
Figure Lengend Snippet: BRG1 promoted Smad3 phosphorylation by regulating Ppp2r1a transcription. (A) Western blot analysis of p-Smad3 and t-Smad3 protein levels in CFs following co-transfection with BRG1 and siZEB1. *** p < 0.001 vs. Ctl group or BRG1+NC group by one-way ANOVA followed by Tukey’s post hoc analysis. n = 6. (B) Immunofluorescence staining reveals the nuclear translocation of Smad3 in CFs. Smad3 (green) and nuclei (DAPI, blue) were labeled. Scale bar = 25 μm. (C,D) Western blot analysis of Col-I and FN1 protein levels in CFs treated with OA following co-transfection with BRG1 overexpression plasmids and siZEB1. * p < 0.05, ** p < 0.01, *** p < 0.001 vs. indicated groups by one-way ANOVA followed by Tukey’s post hoc analysis. n = 6. (E) In primary mouse fibroblasts with siBRG1, qRT-PCR was employed to evaluate PP2A subunit ( Ppp2ca , Ppp2cb , Ppp2r1a , Ppp2r1b , Ppp2r2a , Ppp2r2b , Ppp2r2c , Ppp2r2d , Ppp2r3a ) mRNA expression. ** p < 0.01 vs. NC group by a two-tailed Student’s t-test. n = 4. (F) Luciferase reporter assay of Ppp2r1a promoter activity in CFs transfected with siZEB1. *** p < 0.001 vs. NC group. (G) Luciferase reporter assay of Ppp2r1a promoter activity in CFs transfected with siBRG1. *** p < 0.001 vs. NC group. (H) Luciferase reporter assay of Ppp2r1a promoter activity in CFs co-transfected with BRG1 overexpression plasmid and siZEB1 *** p < 0.001 vs. Ctl group or BRG1+NC group by one-way ANOVA followed by Tukey’s post hoc analysis. n = 10. (I) ChIP analysis identified ZEB1 binding sites in the Ppp2r1a promoter region. (J) ChIP-qPCR analysis of BRG1 and ZEB1 binding to the Ppp2r1a promoter region in CFs. * p < 0.05 and ** p < 0.01 vs. IgG. n = 3. (K) Transfection efficiency of siPpp2r1a was detected by Western blot, *** p < 0.001 vs. NC group by a two-tailed Student’s t-test. n = 6. (L) Immunofluorescence detects nuclear translocation of Smad3 (green) in CFs, with DAPI (blue) marking nuclei. Scale bar = 25 μm. (M,N) Representative Western blotting analysis of t-Smad3 protein level in cytoplasm and nucleus in CFs. β-actin was used as the loading control for cytosolic fractions. Histone3 was used as the loading control for nuclear fractions. * p < 0.05, ** p < 0.01, *** p < 0.001 vs. indicated groups by one-way ANOVA followed by Tukey’s post hoc analysis. n = 6.
Article Snippet: For absolute specificity, ZEB1 (Wanleibio, China, 1:1,000), Ppp2r1a (ABclonal, China, 1:1,000), phospho-Smad3 (Affinity, China, 1:500), and total Smad3 (Affinity, China, 1:500) were probed on separate membranes.
Techniques: Phospho-proteomics, Western Blot, Cotransfection, Immunofluorescence, Staining, Translocation Assay, Labeling, Over Expression, Quantitative RT-PCR, Expressing, Two Tailed Test, Luciferase, Reporter Assay, Activity Assay, Transfection, Plasmid Preparation, Binding Assay, ChIP-qPCR, Control