A comprehensive molecular profiling approach reveals metabolic alterations that steer bone tissue regeneration

Bone regeneration after fracture is a complex process with high and dynamic energy demands. The impact of metabolism on bone healing progression and outcome, however, is so far understudied. Our comprehensive molecular profiling reveals that central metabolic pathways, such as glycolysis and the citric acid cycle, are differentially activated between rats with successful or compromised bone regeneration (young versus aged female Sprague-Dawley rats) early in the inflammatory phase of bone healing. We also found that the citric acid cycle intermediate succinate mediates individual cellular responses and plays a central role in successful bone healing. Succinate induces IL-1 beta in macrophages, enhances vessel formation, increases mesenchymal stromal cell migration, and potentiates osteogenic differentiation and matrix formation in vitro. Taken together, metabolites-here particularly succinate-are shown to play central roles as signaling molecules during the onset of healing and in steering bone tissue regeneration. Metabolites are demonstrated to be critical regulators of fracture healing. Succinate is found to promote vascularization and ossification, highlighting that metabolites have the potential to be used therapeutically to promote fracture healing.

Automated summary

Bone regeneration after fracture is a complex process with high and dynamic energy demands. Metabolites, particularly succinate, are shown to play central roles as signaling molecules during the onset of healing and in steering bone tissue regeneration. Succinate is found to promote vascularization and ossification, highlighting that metabolites have the potential to be used therapeutically to promote fracture healing.