IADR Abstract Archives
MSC Exosomes Modulate PDL Cell Behavior: Implications for Periodontal Regeneration
Objectives: Mesenchymal stem cell (MSC) therapies are currently being explored to enhance the healing potential of the periodontium in the management of periodontal intrabony defects. However, there are operational challenges associated with cell storage and proper handling that limits its clinical use. Increasingly, the therapeutic efficacy of MSCs in tissue repair is attributed to its paracrine secretion, particularly exosomes, which are small membrane vesicles containing a rich cargo of lipids, proteins, and nucleic acids. We hypothesize that these exosomes may be a novel cell-free therapeutic to promote periodontal regeneration. Therefore, this study investigates the effects of MSC exosomes on cellular migration, proliferation, and osteogenic differentiation of periodontal ligament (PDL) cells.
Methods: Exosomes were purified from conditioned medium of human MSCs. Rat PDL cells were treated with varying doses (1, 5 and 10µg/ml) of exosomes or the vehicle control (phosphate buffered saline [PBS]) in cellular migration, proliferation and osteogenic differentiation assays. Alizarin red staining was performed to assess osteogenic differentiation and mineralization of PDL cells. Activation of pro-survival AKT and ERK kinases was measured by immunoblotting.
Results: MSC exosomes displayed a modal size of 100nm and expressed exosome markers (CD81, TSG101 and ALIX). MSC exosomes showed dose-dependent effects on PDL cellular migration and proliferation. Compared to controls, PDL cells treated with 10µg/ml exosomes demonstrated more than 2-fold increase in cellular proliferation (P<0.05) and migratory activity (P<0.001). Interestingly, MSC exosomes enhanced osteogenic mineralization of PDL cells at 1µg/ml, but this effect diminished at increasing concentrations. Rapid phosphorylation of AKT and ERK was observed with exosome treatment, and inhibition of AKT/ERK activation significantly attenuated exosome-induced migration, proliferation and osteogenic differentiation of PDL cells.
Conclusions: MSC exosomes exert positive effects on PDL cellular functions that are relevant to periodontal regeneration. Higher doses of MSC exosomes favored cellular proliferation and migration whereas lower doses favored osteogenic differentiation of PDL cells.
Methods: Exosomes were purified from conditioned medium of human MSCs. Rat PDL cells were treated with varying doses (1, 5 and 10µg/ml) of exosomes or the vehicle control (phosphate buffered saline [PBS]) in cellular migration, proliferation and osteogenic differentiation assays. Alizarin red staining was performed to assess osteogenic differentiation and mineralization of PDL cells. Activation of pro-survival AKT and ERK kinases was measured by immunoblotting.
Results: MSC exosomes displayed a modal size of 100nm and expressed exosome markers (CD81, TSG101 and ALIX). MSC exosomes showed dose-dependent effects on PDL cellular migration and proliferation. Compared to controls, PDL cells treated with 10µg/ml exosomes demonstrated more than 2-fold increase in cellular proliferation (P<0.05) and migratory activity (P<0.001). Interestingly, MSC exosomes enhanced osteogenic mineralization of PDL cells at 1µg/ml, but this effect diminished at increasing concentrations. Rapid phosphorylation of AKT and ERK was observed with exosome treatment, and inhibition of AKT/ERK activation significantly attenuated exosome-induced migration, proliferation and osteogenic differentiation of PDL cells.
Conclusions: MSC exosomes exert positive effects on PDL cellular functions that are relevant to periodontal regeneration. Higher doses of MSC exosomes favored cellular proliferation and migration whereas lower doses favored osteogenic differentiation of PDL cells.