NUPR1 acts as a prosurvival factor in human bone marrowderived mesenchymal stem cells and is induced by the hypoxia mimetic reagent deferoxamine

Differences in the culturing conditions of mesenchymal stem cells used in regenerative medicine may affect their differentiation ability, genome instability, and therapeutic effects. In particular, bone marrowderived mesenchymal stem cells cultured under hypoxia are known to proliferate while maintaining an undiffer entiated state and the use of deferoxamine, a hypoxia mimetic reagent, has proven to be a suitable strategy to maintain the cells under hypoxic metabolic state. Here, the deferoxamine effects were investigated in mesenchymal stem cells to gain insights into the mechanisms regulating stem cell survival. A 12h deferox amine treatment reduced proliferation, oxygen consumption, mitochondrial activity, and ATP production. Microarray analysis revealed that deferoxamine enhanced the transcription of genes involved in glycolysis and the HIF1α pathway. Among the earliest changes, transcriptional variations were observed in HIF1α, NUPR1, and EGLN, in line with previous reports showing that short deferoxamine treatments induce substantial changes in mesenchymal stem cells glycolysis pathway. NUPR1, which is induced by stress and involved in autophagymediated survival, was upregulated by deferoxamine in a concentrationdependent manner. Consistently, NUPR1 knockdown was found to reduce cell proliferation and increase the proapoptotic effect of stauro sporine, suggesting that deferoxamineinduced NUPR1 promotes mesenchymal stem cell survival and cytoprotective autophagy. Our findings may substantially contribute to improve the effec tiveness of mesenchymal stem cellbased regenerative medicine.