IADR Abstract Archives
MSC Exosomes Enhance DPC Functions: Potential for Dental Pulp Regeneration
Objectives: Dental pulp remains one of the most challenging dental tissues for repair and regeneration. Mesenchymal stem cell (MSC) therapies are currently being explored for dental pulp regeneration. However, cell-based MSC therapies are hampered by stringent requirements to maintain the cell potency and viability. Increasingly, the therapeutic efficacy of MSCs is attributed to the secretion of trophic factors, particularly exosomes. Here, we investigate the effects of MSC exosomes on cellular uptake, migration, viability and proliferation, and odontogenic/osteogenic differentiation of dental pulp cells (DPCs).
Methods: Exosomes were purified from conditioned medium of human MSCs and stored at -20°C until use. To determine the uptake of exosomes, rat DPCs were incubated with dye-labelled exosomes and observed by confocal microscopy over 24h. To assess the effects of MSC exosomes on DPC functions, rat DPCs were treated with varying concentrations (1, 5 and 10µg/ml) of exosomes or the vehicle control (phosphate buffered saline [PBS]) in cellular migration, viability, proliferation and differentiation assays.
Results: MSC exosomes displayed a modal size of 100nm and expressed exosomal markers (CD81, TSG101 and ALIX). In uptake assay, we observed that rat DPCs rapidly endocytosed the exosomes and became fluorescent within 1h. We also observed dose-dependent effects of MSC exosomes on DPC migration, viability and proliferation. Compared to PBS control, DPCs treated with 10µg/ml exosomes demonstrated >1.5-fold increase in cellular migratory activity (P<0.001), viability (P<0.001) and proliferation (P<0.001). These enhancements were supported by our gene expression analysis that showed rapid upregulation of genes associated with migration (FGF-2, SDF-1α), survival (Survivin, Bcl-2) and proliferation (FGF-2) (P<0.05) within 24h. Under odontogenic/osteogenic culture condition, MSC exosomes at 10µg/ml accelerated DPC mineralization with significant calcium deposition detected as early as day 7.
Conclusions: MSC exosomes interact directly with DPCs and exert positive effects on DPC functions that are relevant to dental pulp regeneration.
Methods: Exosomes were purified from conditioned medium of human MSCs and stored at -20°C until use. To determine the uptake of exosomes, rat DPCs were incubated with dye-labelled exosomes and observed by confocal microscopy over 24h. To assess the effects of MSC exosomes on DPC functions, rat DPCs were treated with varying concentrations (1, 5 and 10µg/ml) of exosomes or the vehicle control (phosphate buffered saline [PBS]) in cellular migration, viability, proliferation and differentiation assays.
Results: MSC exosomes displayed a modal size of 100nm and expressed exosomal markers (CD81, TSG101 and ALIX). In uptake assay, we observed that rat DPCs rapidly endocytosed the exosomes and became fluorescent within 1h. We also observed dose-dependent effects of MSC exosomes on DPC migration, viability and proliferation. Compared to PBS control, DPCs treated with 10µg/ml exosomes demonstrated >1.5-fold increase in cellular migratory activity (P<0.001), viability (P<0.001) and proliferation (P<0.001). These enhancements were supported by our gene expression analysis that showed rapid upregulation of genes associated with migration (FGF-2, SDF-1α), survival (Survivin, Bcl-2) and proliferation (FGF-2) (P<0.05) within 24h. Under odontogenic/osteogenic culture condition, MSC exosomes at 10µg/ml accelerated DPC mineralization with significant calcium deposition detected as early as day 7.
Conclusions: MSC exosomes interact directly with DPCs and exert positive effects on DPC functions that are relevant to dental pulp regeneration.
