Fig 2: KLF15 improved Ang II-induced cardiac remodeling through TAD. AdCTL, AdKLF15 and Ad KLF15-?TAD-infected mice were infused with saline or Ang II for 14 days. (A) Representative heart size, WGA stain, Masson stain and a-SMA immunofluorescence image. (B) Statistical analysis of heart weight/body weight ratio. (C) Quantification analysis of myocyte section area. (D) Quantification analysis of fibrotic area measured by Masson stain. (E) Quantification analysis of a-SMA positive area measured by immunofluorescence. (F) Statistical analysis of blood pressure. (G–I) qPCR analysis of mRNA levels of ANP, BNP, Collagen 1a1 and CXCL1. *P < 0.05, **P < 0.01, and ***P < 0.001.

Fig 3: KLF15-TAD negatively regulated CXCL1 transcription in CF. CF and H9c2 cells were stimulated by different doses of Ang II for 24 h. (A,B) KLF15 level was measured and quantified by Western Blot analysis. (C,D) The CXCL1 protein in cell supernatant of Ang II treated CF and H9c2 cells was detected by an Elisa assay. (E) CF cells were transfected with con-siRNA and KLF15-siRNA. Successful knockout of KLF15 by KLF15-siRNA was confirmed by Western Blot. (F) CXCL1 mRNA levels of Ang II-treated WT CF and KLF15 knockdown CF were measured by qPCR. (G) Adenovirus-mediated overexpression of KLF15 and deletion of transactivation domain (TAD) of KFL15 were verified by Western Blot. (H) Luciferase assay was used to detect CXCL1 promoter activity in AdCTL, AdKLF15, and AdKLF15-?TAD-infected CFs. (I) CXCL1 mRNA levels of AdCTL, AdKLF15, and AdKLF15-?TAD infected CFs were measured and analyzed by qPCR. *P < 0.05, **P < 0.01, and ***P < 0.001.

Fig 4: Deficiency of KLF15 aggravated Ang II-induced cardiac remodeling. Wild-type (WT) mice and KLF15 knockout (KO) mice were infused with saline or Ang II for 14 days. (A) Representative heart size, WGA stain, Masson stain, and a-SMA immunofluorescence image. (B) Statistical analysis of heart weight/body weight ratio. (C) Quantification analysis of myocyte section area. (D) Quantification analysis of fibrotic area measured by Masson stain. (E) Quantification analysis of a-SMA positive area measured by immunofluorescence. (F) Statistical analysis of blood pressure. (G–I) qPCR analysis of mRNA levels of ANP, BNP, Collagen 1a1, and CXCL1. *P < 0.05, **P < 0.01, and ***P < 0.001.

Fig 5: Inhibition of CXCR2 rescued KLF15 KO-aggravated cardiac remodeling. KLF15 KO mice was i.p. injected with SB265610 (2 mg/kg/day) and infused with Ang II for 14 days. WT and KLF15 KO mice only infused with Ang II were used as control. (A) M-mode echocardiography of left ventricular chamber. (B) Measurement of ejection fraction (EF%) and fractional shortening (FS%). (C) Representative heart size, WGA stain, Masson stain and a-SMA immunofluorescence image. (D) Heart weight/body weight ratio. (E) Quantification of myocyte section area. (F) Quantification of fibrotic area revealed by Masson staining. (G) Quantification of a-SMA positive area. (H) Statistical analysis of blood pressure. (I,J) qPCR analysis of mRNA levels of Collagen 1a1, ANP and BNP. (K,L) Western Blot and quantification analysis of CXCR2/GAPDH. (M–P) Western Blot and quantification analysis of P-mTOR/T-mTOR, P-ERK1/2/T-ERK1/2 and P-p65/T-p65 of mice hearts. *P < 0.05, **P < 0.01, and ***P < 0.001. (Q) A working model describing that KLF15 in cardiac fibroblasts negatively regulates CXCL1/CXCR2 axis-mediated inflammatory response and subsequent cardiac remodeling in hypertension.