Objective: To investigate the effect of Secreted frizzled-related protein 1 (Sfrp1) on myocardial fibroblasts through Wnt/β-catenin signaling pathway.
Materials and methods: Rat myocardial fibroblasts were cultured and divided into control group, proliferation group (TGF-β1 group), and Sfrp1 transfection group (TGF-β1 + Ad-Sfrp1 group). The control group received no treatment. The TGF-β1 group was stimulated with TGF-β1 10 ng/mL for 12 h to establish a proliferation model. The TGF-β1 + Ad-Sfrp1 group was first transfected with Ad-Sfrp1 virus. On day 3, TGF-β1 was added at 10 ng/mL to stimulate 12 h. The β-catenin and the marker protein α-SMA of myofibroblast (MyoFB) differentiation were detected by Western blotting method. In addition, we used MTT to test cell proliferation and flow cytometry to test cell cycle. At the same time, we used enzyme-linked immunosorbent assay (ELISA) to detect the collagen I and collagen III content of the cell supernatant and used quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) to test the expression of apoptotic factors and Dvl-1 and Cyclin D1.
Results: In TGF-β1 group, the β-catenin, and α-SMA protein expressions were all upregulated, the OD value and collagen I and collagen III contents were increased, but the apoptosis rate was decreased. On the contrary, the expression of β-catenin and α-SMA proteins in the TGFβ1 + Ad-Sfrp1 group were all downregulated, the OD value, collagen I and collagen III content, and percentage of S-phase cells were reduced, but the percentage of G0/G1, G2/M-phase cells, and the apoptotic rate increased.
Conclusions: Sfrp1 can effectively inhibit myocardial fibroblast proliferation, collagen synthesis, promote fibroblast apoptosis, and inhibit the transformation of fibroblasts into myofibroblasts by inhibiting Wnt/β-catenin signaling pathway.