Senescence-Associated Metabolomic Phenotype in Primary and iPSC-Derived Mesenchymal Stromal Cells

Abstract

Long-term culture of primary cells is characterized by functional and secretory changes, which ultimately result in replicative senescence. It is largely unclear how the metabolome of cells changes during replicative senescence and if such changes are consistent across different cell types. We have directly compared culture expansion of primary mesenchymal stromal cells (MSCs) and induced pluripotent stem cell-derived MSCs (iMSCs) until they reached growth arrest. Both cell types acquired similar changes in morphology, in vitro differentiation potential, senescence-associated b-galactosidase, and DNA methylation. Furthermore, MSCs and iMSCs revealed overlapping gene expression changes, particularly in functional categories related to metabolic processes. We subsequently compared the metabolomes of MSCs and iMSCs and observed overlapping senescence-associated changes in both cell types, including downregulation of nicotinamide ribonucleotide and upregulation of orotic acid. Taken together, replicative senescence is associated with a highly reproducible senescence-associated metabolomics phenotype, which may be used to monitor the state of cellular aging.

Genetic barcoding reveals clonal dominance in iPSC-derived mesenchymal stromal cells

“…However, during culture expansion, iMSCs undergo replicative senescence-like primary MSCs. Accordingly, we have recently demonstrated that MSCs and iMSCs entered a senescent state after 21.3 ± 1.4 and 17.1 ± 3.8 cumulative population doublings, respectively [45]. Furthermore, this process is associated with very similar changes in morphology, differentiation potential, expression of senescence-associated betagalactosidase, transcriptome, epigenome, and metabolome [45].…”

Identification of senescent cells in multipotent mesenchymal stromal cell cultures: Current methods and future directions

“…In one study, senescent MSCs did not appear to utilise anaerobic glycolysis and instead, produced ATP primarily via oxidative phosphorylation, a metabolic activity more consistent with differentiated cells [37]. However, a more recent study has shown that senescenceassociated changes in MSCs included down-regulation of nicotinamide ribonucleotide and up-regulation of orotic acid, and reflected the metabolic switch from oxidative to glycolytic pathways, possibly to avoid further damage by ROS [38].…”

Molecular Mechanisms Contributing to Mesenchymal Stromal Cell Aging

“…Contradictory results have been published concerning senescent MSC metabolism; Capasso et al [39] documented a shift from glycolysis to oxidative phosphorylation, whereas Fernandez-Rebollo et al [160] observed a metabolic switch from oxidative to glycolytic pathways, possibly to avoid further damage by ROS.…”