Midkine Enhances Early Stages of Collagen Gel Contraction1.

Midkine (MK) is a heparin-binding growth/differentiation factor implicated in the control of development and repair of various tissues. To investigate the roles of MK in embryogenesis and in regulation of wound healing, we utilized a system of collagen gel contraction by dermal fibroblasts, which provides an in vitro model for studying fibro-blast-collagen interactions important in various physiological and pathological phe-nomena. MK enhanced gel contraction 8–24 h after plating, and its effect was inhibited by anti-MK antibody. The effect was reduced after 48 h, while TGF-p continued to be active in the later stage. Morphologically, MK-treated fibroblasts tended to be elongated more frequently than control fibroblasts. The effect of MK in the early stage of gel contraction suggests a role of MK as a modulator of cell-matrix interactions. [ABSTRACT FROM AUTHOR]