Fig. 1.

Stability of MSC lineage profiles during prolonged UC-MSC expansion. a Most interrogated transcripts in the Roson-Burgo MSC lineage gene set (433/445) are expressed and unchanged by extended passaging. SMIM14 is never detected, while 9 other genes are expressed intermittently during cell propagation. EMP2 and IER3IP1 are downregulated with age but remain detectable. b Genes previously linked to senescence (CDKN2A) or aging (CLN8, FAS) as defined by Gene Ontology functional classification are upregulated at P10, 11, and 12 versus P2 (p < 0.05, > 1.5-fold change) [6]. c Four of the 11 tested Rohart MSC genes are reliably expressed by serially expanded UC-MSCs, although PRRX1 expression decreases in pre-senescent cells. Four genes (CES1P1, HSPB3, OMD, and ABI3BP) are essentially undetectable. C1orf115, SAA2, and KIAA1199 are expressed throughout cell expansion but are deemed unreliable since expression intensity occasionally falls below the detection limit. Graphs depict the mean ± SEM of biological replicates. Abbreviations: P, passage. *p < 0.05 and > 2-fold change