Fig. 3. Culture expansion induces human mesenchymal stem cell (hMSC) metabolic reconfiguration.

a Glycolytic ATP ratio was decreased during culture expansion of hMSCs. b mRNA level of genes in glycolysis and pentose phosphate pathways (PPP) of hMSCs during culture expansion. c Lactate (Lac) production/glucose (Glc) consumption ratio of hMSCs during extensive expansion. Gas chromatography–mass spectrometry (GC–MS) analysis of hMSCs during culture expansion. d Internal normalized peak area of lactate. e Absolute total molar percent enrichment (ATMPE) levels of ¹³C-glucose atoms in metabolites involved in glycolysis and OXPHOS. f The relative molar percent enrichment (RMPE) levels of citrate. g OCR/ECAR ratio changes with time of culture in hMSCs at early and late passage. h hMSC energy metabolic phenotype during culture expansion based on OCR and ECAR, open square: basal condition; closed square: stressed condition. Biological replicates (n): n = 6 for GC–MS metabolite study, n = 3 for rest of the tests. *p < 0.05; **p < 0.01.