Oestrogen retains human periodontal ligament stem cells stemness in long-term culture

ObjectivesDuring long-term culture, loss of stemness is observed which greatly restricts the application of human periodontal ligament stem cells (hPDLSCs) in tissue regeneration. Oestrogen (E2) was found to significantly enhance the proliferation and osteogenic differentiation capacity in mesenchymal stem cells. Therefore, in this study, we investigated effects of E2 on hPDLSCs stemness in long-term culture. Materials and methodsEffects of E2 on hPDLSCs stemness were systematically evaluated. To characterize underlying the mechanisms, its effects on PI3K/AKT signalling pathway were determined. ResultsOur results showed that E2 was able to enhance the proliferation, modify cell cycle, up-regulate stemness-related genes expression, promote osteogenic differentiation and elevate the positive rate of CD146 and STRO-1 over 10 passages in hPDLSCs. Importantly, PI3K/AKT signing pathway might play a role in these effects. ConclusionsThese findings suggest that E2 retains hPDLSCs stemness in long-term culture, which might enhance its application in tissue engineering.