Histopathological changes in tendinopathy--potential roles of BMPs?

The pathogenesis of tendinopathy remains unclear. Chondro-osteogenic BMPs such as BMP-2, BMP-4 and BMP-7 have been reported in clinical samples and animal models of tendinopathy. As chondrocyte-like cells and ossified deposits have been observed in both clinical samples and animal models of failed tendon healing tendinopathy, chondro-osteogenic BMPs might contribute to tissue metaplasia and other histopathological changes in tendinopathy. In this review I have summarized the current evidence supporting the roles of chondro-osteogenic BMPs in the histopathological changes of tendinopathy. The potential targets, effects and sources of these BMPs are discussed. I have also provided directions for future studies about the potential roles of BMPs in the pathogenesis of tendinopathy. Better understanding of the roles of these BMPs in the histopathological changes of tendinopathy could provide new options for the prevention and treatment of this disabling tendon disorder.