Osteogenic Differentiation Effect of Human Periodontal Ligament Stem-Cell Initial Cell Density on Autologous Cells and Human Bone Marrow Stromal Cells

Abstract

Stem cells have differentiation and regulation functions. Here, we discussed the impact of cell culture density on stem cell proliferation, osteoblastogenesis, and regulation. To discuss the effect of the initial culture density of human periodontal ligament stem cells (hPDLSCs) on the osteogenic differentiation of autologous cells, we found that the hPDLSC proliferation rate decreased with an increase in the initial plating density (0.5–8 × 104 cells/cm2) for the 48 h culture cycle. After hPDLSCs induced osteogenic differentiation for 14 days with different initial cell culture densities, the expression of osteoprotegerin (OPG) and runt-related transcription factor 2(RUNX2) and the OPG/ Receptor Activator of Nuclear Factor-κ B Ligand (RANKL) ratio were the highest in the hPDLSCs initially plated at a density of 2 × 104 cells/cm2, and the average cell calcium concentration was also the highest. To study hPDLSCs regulating the osteoblastic differentiation of other cells, we used 50 μg/mL of secreted exosomes derived from hPDLSCs cultured using different initial cell densities to induce human bone marrow stromal cell (hBMSC) osteogenesis. After 14 days, the results indicated that the gene expression of OPG, Osteocalcin(OCN,)RUNX2, and osterix and the OPG/RANKL ratio were the highest in the 2 × 104 cells/cm2 initial cell density group, and the average calcium concentration was also the highest. This provides a new idea for the clinical application of stem cell osteogenesis.

Comparative clinical study of phosphorous-necrosis and medical-related osteonecrosis of the jaws

“…Additionally, there were signi cantly fewer collagen bres and osteocytes in the bone structure of MRONJ patients, resulting in a roughened bone surface where osteocytes were challenging to distinguish. Importantly, RANKL is well-known for its role in bone remodeling by regulating bone resorption, while Runx2 plays a crucial role in promoting the differentiation and maturation of osteoblasts [24,25] . The ndings from this study suggest that RANKL expression was at its lowest in MRONJ, while Runx2 expression was highest in PNJ.…”