Umbilical Cord Mesenchymal Stem Cells Enhanced Pluripotency Through Modifying Microenvironment

Objectives: Dental pulp cells (DPCs) are important cell source for dental regeneration, albeit their application is restricted by limited pluripotency due to current culture system. Umbilical cord mesenchymal stem cells (UCMSCs) are served as feeder layer to maintain undifferentiated state of iPSCs and ESCs through modifying microenvironment. Basic fibroblast growth factor (bFGF) involves in cell fate determination. However, until now the effect of microenvironment on DPCs remains unknown.
Methods: To investigate the effect of optimized culture condition on the pluripotency of DPCs, cell proliferation, senescence, cell cycle and expression of pluripotent markers of DPCs with UCMSCs-CM and/or bFGF-CM were detected by CCK8，flow cytometry analysis，SA-β-gal staining，RT-PCR and western blot. Multilineage differentiation capability was examined by specific staining and RT-PCR. Expression of bFGF secreted by UCMSCs in the co-culture medium was evaluated by ELISA. FGF receptor inhibitor SU5402 was applied to further investigate the effect of UCMSCs-CM and/or bFGF-CM on DPCs．
Results: Cell proliferation，multilineage differentiation and mRNA/protein expression of pluripotentcy markers were enhanced and the senescence was depressed in DPCs with UCMSCs-CM and/or bFGF-CM. SU5402 effectively restrained the UCMSCs-CM and/or bFGF-CM induced upregulation of cell proliferation, multilineage differentiation and expression of pluripotentcy markers of DPCs, albeit boosted cell senescence．
Conclusions: Both UCMSCs and bFGF enhanced pluripotency of DPCs through optimizing microenvironment.