Pathological study on mast cells and their released protease and transforming growth factor-β1 in lymphedema skin tissue

Abstract

Objective To explore the relationship between protease-chymase secreted by mast cells, and activated transforming growth factor-β1(TGF-β1), in skin with secondary lymphedema(SLE)in lower extremity, so as toidentify the key factors in fibrosis of lymphedema. Methods In this study, the affected limb skin of 7 SLE patients was includedas the experimental group, and normal skin tissue of the lower limb of 7 volunteers was used as controls. The skin samples were assayed by Masson staining, and the expressions of chymase and TGF-β1 were assayed by immunohistochemistry, immunofluorescent staining and enzyme-linked immunosorbent assay. Results There was obvious fibrosis in the skin of lower extremity in patients with lymphedema. The number of MCs andthe expressions of chymase, latency-associated peptide TGF-β1 (LAP TGF-β1) and TGF-β1 were all significantly increased in fibrotic skin in lymphedema, compared with those in normal skin. At the same time, the chymase-containing mast cells accumulated in the lymphatic vessels, with higher expression of TGF-β1. Conclusions The expression of chymase and TGF-β1 was significantly increased in the fibrotic skin insecondary lower extremity lymphedema. The increased expression of chymase in the skin may activate more TGF-β1 expression, and the increased TGF-β1 may promote skin fibrosis in SLE. Key words: Lymphedema; Mast cell; Transforming growth factor-β1