Hypoxia upregulates the expression of the pluripotency markers in the stem cells from human deciduous teeth

ObjectivesCultivation under hypoxia promotes different responses in the mesenchymal stem cells and it has been producing promising results for clinical applications. Pulp tissue from deciduous teeth is a source of stem cells which has a high proliferative potential but this is usually discarded. This study has evaluated the effects of hypoxia on proliferation, apoptosis, and the expression of the pluripotency-related genes of the stem cells from human exfoliated deciduous teeth (SHED).Materials and methodsThe cells were isolated from dental pulp (n=5) and characterized as mesenchymal stem cells, in accordance with the International Society for Cell Therapy. The cells were cultivated under hypoxia (3% oxygen) and compared to the normoxia cells (21% oxygen). The proliferation rate was evaluated by the Ki67 antibody for up to 7days, while the metabolic activity was measured by the wst-8 assay for up to 14days. The apoptotic cells were analyzed by Annexin V and propidium iodide staining at 24h and 4 and 7days. The expression of the pluripotent genes (OCT4, SOX2, and NANOG) was quantified by qPCR after 24h, or 7days, when cultivated under hypoxia or normoxia.ResultsNo differences in the metabolic activity, the proliferation rate, and the apoptosis of SHED when cultivated under hypoxia or normoxia (p>0.05) were observed. The expression of the pluripotent genes was significantly higher after 24h and 7days of the cells that were exposed to hypoxia (p<0.01).ConclusionThese findings have indicated an increase of the pluripotency-related genes within 7days as being the main advantage of SHED culture under hypoxia.Clinical relevanceHypoxia culture may help maintain the quiescent state of the SHED, which could be advantageous for their future clinical applications.