Mast cell tryptase stimulates both human dermal fibroblast proliferation and type I collagen production

Mast cell tryptase has been shown to be mitogenic for fibroblasts, however, it still remains unknown whether mast cell tryptase stimulates collagen production by human derrmal fibroblasts.

We have investigated the effect of mast cell tryptase on type I collagen production by human dermal fibroblasts as well as the proliferation of the fibroblasts.

Tryptase isolated from human lung tissue was added to the culture of fibroblasts from normal dermis, and the fibroblast proliferation and the activity of type I collagen synthesis in the supernatants were assayed, respectively.

Fibroblast proliferation was increased with tryptase in a concentration-dependent manner, and a significant increase was observed in the presence of tryptase at concentrations from 0.01 to 10 microg/mL. The increase of fibroblast proliferation with 3 microg/mL tryptase was significantly reduced by 15 microg/mL antitryptase IgG antibody, which was demonstrated to inhibit fibrinogenolysis of tryptase. On the other hand, the production of type I collagen by the fibroblasts was significantly increased with tryptase at a concentration of 10 microg/mL. The collagen production in the presence of 10 microg/mL tryptase was significantly inhibited by 50 microg/mL antitryptase IgG antibody.

Tryptase increases not only the proliferation of human dermal fibroblasts but also type I collagen production.