Summary
Bone morphogenetic proteins (BMPs) are members of the TGF-β superfamily of secreted
ligands. BMPs regulate a diverse range of developmental processes during embryogenesis
and postnatal development, and control the differentiation of several musculoskeletal
tissues including bone, cartilage, tendon and ligaments. The ability of BMPs to modulate
the phenotype of cells in these tissue lineages suggests that these factors could
be valuable for musculoskeletal tissue regeneration. In fact, BMPs-2 and -7 are already
in clinical use for bone regeneration. This review addresses the signaling mechanisms
by which BMPs regulate cellular processes, the role of BMPs in articular cartilage
development and joint formation, and the data that supports the use of BMPs for in vitro phenotypic support of articular chondrocyte cultures, chondrogenic differentiation
of mesenchymal stem cells (MSCs) and articular cartilage repair. Given the documented
importance of BMP activity for normal joint formation, articular cartilage development
and maintenance, the chondrogenic activity of BMPs when applied to MSC cultures and
the encouraging outcomes of several in vivo cartilage repair studies, BMP therapies hold considerable promise for effective cartilage
repair and/or regeneration. Future advances in the control of BMP elution from biocompatible
matrices and prolonged, dose-controlled BMP expression by genetically engineered cells
should substantially improve cartilage repair strategies using BMPs and similar chondro-protective
proteins.
Keywords
BMP - articular cartilage - cartilage repair