Fig. 3: Conditional myofibroblast-specific Irx2 depletion attenuated angiotensin II (Ang II) or pressure overload-induced cardiac fibrosis in mice.

A Conditional myofibroblast-specific Irx2-deficient mice (Irx2 mfKO) were bred by crossing mice with a conditional knockout allele of Irx2 (Irx2^fl/fl) with Postn-Cre mice. Irx2 mfKO mice and littermate controls were subjected to Ang II infusion for 12 weeks. B Representative western blots and statistical analysis of IRX2 protein expression in CFs isolated from Irx2 mfKO mice and littermate controls after Ang II infusion for 12 weeks (n = 5). C Heart weight-to-tibia length (HW/TL) ratio (n = 10 mice, Postn-Cre+Saline; n = 11 mice, Irx2^fl/fl+Saline; n = 11 mice, Irx2 mfKO+Saline; n = 10 mice, Postn-Cre+Ang II; n = 12 mice, Irx2^fl/fl+Ang II; n = 12 mice, Irx2 mfKO+Ang II). D Cardiac fibrosis was determined by picrosirius red staining for Irx2 mfKO mice after Ang II infusion for 12 weeks (n = 5). E The cell area of cardiomyocytes was determined with wheat germ agglutinin (WGA) staining for Irx2 mfKO and littermate controls after Ang II infusion for 12 weeks (n = 5). F The relative mRNA levels of Col1 and Col3 were detected in hearts from Irx2 mfKO mice and control mice (n = 6). G, H The ejection fraction (EF) (G) and left ventricular end-diastolic dimension (LVIDd) (H) were detected in these groups (n = 6). I Irx2 mfKO mice and littermate controls were subjected to transverse aortic constriction (TAC) surgery for 6 weeks. J HW/TL ratio (n = 10 mice, Postn-Cre+Sham; n = 11 mice, Irx2^fl/fl+Sham; n = 11 mice, Irx2 mfKO+Sham; n = 10 mice, Postn-Cre+TAC; n = 12 mice, Irx2^fl/fl + TAC; n = 12 mice, Irx2 mfKO+TAC). K Histological staining showing cardiac fibrosis after TAC surgery in Irx2 mfKO mice (n = 5). L Cell area of cardiomyocytes determined with WGA staining after TAC surgery (n = 5). M, N EF (M) and LVIDd (N) detected in these groups (n = 8).The data were compared by one-way ANOVA. Data are shown as the mean ± SEM, and analysed using one-way ANOVA followed by Tukey post hoc test (D–H and L–N) or Tamhane’s T2 test (C, and J–K). For the analysis in (B), an unpaired two-tailed Student′s t test was conducted. Source data are provided as a Source Data file.