Metabolomics Assessment of Human Induced Pluripotent Stem Cells: Initial Transition PatternsAuthor(s): Andrew Symonds
Cell differentiation towards specific lineages remains a challenge. . In this study, nontargeted metabolomic analysis techniques were used to analyze extracellular metabolites present in samples as small as 1 microliter. HiPSCs were differentiated by initiating culture under basal medium E6 in combination with chemical inhibitors previously reported to promote differentiation toward the ectodermal lineage. B. Wnt/ -catenin and TGF- -kinase/ activin receptor, alone or in combination with inhibition of bFGF and glycogen kinase 3 (GSK-3). This is commonly used to redirect hiPSCs to the mesodermal lineage. At 0 and 48 hours, 117 metabolites were identified, including biologically relevant metabolites such as lactate, pyruvate and amino acids. By measuring the expression of the pluripotency markers OCT3/4, we were able to correlate the differentiation state of the cells with the shifted metabolites. A group of cells that underwent ectodermal differentiation showed a significant decrease in OCT3/4 expression. In addition, metabolites such as pyruvate and kynurenine showed dramatic changes under ectodermal differentiation conditions, with pyruvate consumption increased 1–2-fold and kynurenine secretion decreased 2-fold. Further metabolite analysis reveals a group of metabolites specifically associated with the ectodermal lineage and the potential of our results for characterizing hiPSCs during cell differentiation, especially under ectodermal lineage conditions.