Fig. 1: Identification of a Klotho-derived peptide (KP1) that inhibits TGF-β1 action in vitro.
From: A Klotho-derived peptide protects against kidney fibrosis by targeting TGF-β signaling
a Amino acid sequence alignment of KP1 in various species. A light green background indicates the regions with identical amino acids in different species. Differences in amino acids among various species are highlighted by red color. b KP1 inhibited the induction of α-SMA mRNA by TGF-β1 in NRK-49F cells. NRK-49F cells were incubated with TGF-β1 (2 ng/ml) in the absence or presence of KP1 (10 µg/ml) or sKlotho (10 µg/ml). The expression of α-SMA mRNA was assessed by qRT-PCR. P values (from left to right): <0.001, 0.001, <0.001. n = 4 biologically independent cells. c–e KP1 inhibited the protein expression of fibronectin and α-SMA. NRK-49F cells were preincubated with KP1 (10 µg/ml; 3 µM) for 1 h and then treated with TGF-β1 (2 ng/ml) for 24 h. Western blot (c) and quantitative data (d, e) are presented. P values (from left to right): 0.001 and 0.004 (fibronectin); 0.017 and 0.026 (α-SMA). n = 3 biologically independent cells. f KP1 inhibited TGF-β1-mediated fibronectin expression and deposition by NRK-49F cells. Representative micrographs with immunofluorescence staining of fibronectin are shown. Scale bar, 50 µm. Arrows indicated positive staining. g–i KP1 inhibited the expression of fibronectin and α-SMA in primary tubular cells. Western blot analyses (g) and quantitative data of fibronectin (h) and α-SMA (i) are shown. P values (from left to right): 0.001 and 0.001 (fibronectin); 0.001 and 0.003 (α-SMA). n = 3 biologically independent cells. j–l The protein level of fibronectin and collagen I expressed by primary cardiomyocytes. Western blot analyses (j) and quantitative data of fibronectin (k) and collagen I (l) are shown. P values (from left to right):0.001 and 0.001 (fibronectin); <0.001 and <0.001 (collagen I). n = 3 biologically independent cells. Ctrl controls. Data are presented as mean values ± SEM. Statistical significance was determined by one-way ANOVA followed by Fisher’s Least-significant Difference (LSD) post hoc test. Source data are provided as a Source Data file.
