Osteogenic response of human mesenchymal stem cells analysed using combined intracellular and extracellular metabolomic monitoring

BACKGROUND/AIMS The skeleton is a metabolically active organ undergoing continuous remodelling initiated by mesenchymal progenitors present in bone and bone marrow. Under certain pathological conditions this remodelling balance shifts towards increased resorption resulting in weaker bone microarchitecture, and there is consequently a therapeutic need to identify pathways that could inversely enhance bone formation from stem cells. Metabolomics approaches recently applied to stem cell characterisation could help identify new biochemical markers involved in osteogenic differentiation. METHODS Combined intra- and extracellular metabolite profiling was performed by liquid chromatography-mass spectrometry (LC-MS) on human mesenchymal stem cells (MSCs) undergoing osteogenic differentiation in vitro. Using a combination of univariate and multivariate analyses, changes in metabolite and nutrient concentration were monitored in cultures under osteogenic treatment over 10 days. RESULTS A subset of differentially detected compounds was identified in differentiating cells, suggesting a direct link to metabolic processes involved in osteogenic response. CONCLUSION These results highlight new metabolite candidates as potential biomarkers to monitor stem cell differentiation towards the bone lineage.