Human Dental Pulp Cell exosomes vs Human iPS Cell exosomes

Small vesicles, known as exosomes, are secreted from various cell types. Exosomes secreted by mesenchymal stem cells have therapeutic effects against a variety of diseases, and may be able to partially replace stem cell therapies. Previously, we established and characterized human leukocyte antigen (HLA) haplotype homo (HHH) dental pulp cell (DPC) lines from human wisdom teeth. In this report, we purified the exosomes secreted from HHH-DPCs and evaluated their therapeutic potential in a periodontitis model. The exosomes purified from HHH-DPCs showed homogeneous and spherical membrane structures, and showed low but significant expression of HLA class I molecules. The exosomes further promoted proliferation and migration in DPCs. A comparison of miRNAs revealed that the HHH-DPC exosomes contained higher levels of multiple Let-7 family miRNAs compared to HHH-induced pluripotent stem cell (iPSC)-derived exosomes. Finally, the HHH-DPC exosomes showed preventive effects in a mouse model of periodontitis induced by lipopolysaccharides (LPS). In summary, HHH-DPC exosomes expressed HLA molecules which may induce an immune response in HLA-mismatched transplantations. However, they successfully stimulated the proliferation and migration of cells and showed suppressive effects on LPS-induced periodontitis. Therefore, HHH-DPC exosomes show great potential for applications in periodontal treatments. To identify genes expressed in exosomes, comprehensive gene expression analysis was performed using exosomes from DP74, DP94 and DP263 and exosomes from iPS74, iPS94 and iPS263.