Effect Of Mast Cell Chymase On Hypertrophic Scar Fibroblast Proliferation And TGF-β₁/smads Signaling Pathway In Fibroblasts Derived From Hypertrophic Scar

Aims: The present study is to test the existence of mast cell chymase in hypertrophic scars and whether chymase promotes fibrosis via TGF-β1/Smads signaling pathway.Methods:.To detect the existence of mast cells and mast cell chymase in hypertrophic scars, immunohistochemistry was employed. MTT test to detect the cell proliferation of hypertrophic scar fibroblasts.To detect the effect of chymase on TGF-β1, angiotensin, and type I and III collagen m RNA expression in hypertrophic scar fibroblasts, quantitative real-time polymerase chain reaction was performed. To investigate how chymase affects TGF-β1, P-Smad2/3, Smad4 and Smad7 protein expression, Western blotting was carried out.Results: Mast cells and active expression of chymase both exist in hypertrophic scar tissues than control group. Mast cell chymase promotes proliferation of hypertrophic scar fibroblasts. Mast cell chymase promotes the m RNA expression of TGF-β1, angiotensin,and type I and III collagen in hypertrophic scar fibroblasts in a time- and dose-dependent manner than control group(P < 0.05). Treatment with 60 ng/ml mast cell chymase for 12 h up-regulates TGF-β1, P-Smad2/3, Smad4 and Smad7 protein expression in hypertrophic scar fibroblasts than control group(P < 0.05).Conclusions: The present study demonstrates that mast cells and chymase exist in hypertrophic scars and express activity, and chymase promotes hypertrophic scar fibroblast proliferation and collagen synthesis by activating TGF-β1/Smads signaling pathway.