Metabolism as an early predictor of DPSCs aging

Pluripotent stem cells can switch their unique metabolic requirements to facilitate cellular changes but it is not clear if adult stem cells utilize metabolism in a similar manner. Here we studied the metabolism of a human adult stem cell: dental pulp stem cells (DPSCs). The dental pulp from third molars of a diverse patient group was surgically extracted, generating cells that had a high percentage of mesenchymal stem cell markers CD29, CD44, CD146 and Stro1 and had the ability to differentiate into osteogenic and adipogenic lineages. Through RNA seq analysis we identified homeobox protein, Barx1, as a marker for DPSCs. Furthermore, using high throughput proteomic analysis we identified markers for DPSC populations with accelerated replicative senescence. In particular, we show that the transforming growth factor-beta (TGF-ß) pathway and the proteins associated with muscle contraction are upregulated in rapid aging DPSCs, indicating a loss of stem cell characteristics and spontaneous initiation of terminal differentiation. Importantly, using metabolic flux analysis, we identified a metabolic signature for the rapid aging DPSCs. This metabolic signature can be used to predict the onset of replicative senescence phenotypes. Hence, the present study identifies Barx1 as a DPSCs marker and dissects the first predictive metabolic signature for DPSCs aging. Overall design: We did RNA-seq of dental pulp stem cells (DPSC) using our own approach (ID# 29, 43, 44, 45), as well as commercial DPSC and mesenchymal stem cells (MCS) from Lonza.

28

Macrin D, Alghadeer A, Zhao YT, Miklas JW, Hussein AM, Detraux D, Robitaille AM, Madan A, Moon RT, Wang Y, Devi A, Mathieu J, Ruohola-Baker H