Expression and distribution of transforming growth factor-β and decorin during fracture healing

Abstract

To study interactions between TGF-β and decorin, we experimentally induced femoral fracture in rats and immunohistologically examined changes in the distribution of TGF-β and decorin in the femur 3, 7 and 14 days after fracture. In the areas where endochondral ossification occurred, decorin was detected during differentiation of mesenchymal cells into proliferating chondrocytes, while no TGB-β was observed during same period. Once chondrocytes had hypertrophied, decorin was no longer observed, while the matrix around the hypertrophic chondrocytes was positively stained for TGB-β. The disapperance of decorin, almost simultaneously accompanied by the appearance of the active type TGB-β, suggests that decorin regulates the actions of TGB-β.