Intercellular junctions and cell-cell communication in the skeletal system

The cooperative nature of bone remodeling requires efficient means of intercellular recognition, adhesion, and communication that allow cells to sort and migrate, synchronize their activity, equalize hormonal responses, and diffuse local and systemic signals. Direct cell-to-cell interactions via intercellular junctions are fundamental processes for tissue development and homeostasis, affording cells the ability to recognize their microenvironment and communicate with their neighbors. Adherens and gap junctions are abundant in bone and other skeletal cells, where they provide mechanisms to recognize neighboring cells and coordinate signals through bone cell networks and thus adapt to local and systemic cues. The diversity of information elaborated and propagated by cell-cell interactions and intercellular communication results in context-specific biological responses that can direct bone formation and resorption in skeletal development, homeostasis, and disease states. Cell-cell adhesion molecules and gap junctions represent possible targets for therapeutic strategies to enhance response to bone anabolic agents.