Bone marrow stem cells derived exosomes improve osteoporosis by promoting osteoblast proliferation and inhibiting cell apoptosis.

OBJECTIVE: The aim of this study was to investigate whether bone marrow stem cells (MSCs) derived exosomes in rats could promote osteoblast proliferation and improve osteoporosis via inhibiting cell apoptosis. MATERIALS AND METHODS: MSCs in rats were isolated and cultured, followed by the identification of surface antigens via flow cytometry. The differentiation of MSCs was detected by alizarin red staining and oil red staining. After extraction from MSCs by ultracentrifugation, the size distribution of exosomes was detected by tunable resistive pulse sensing (TRPS). Specific antigens in MSCs-derived exosomes were determined by flow cytometry. Furthermore, the proliferation and viability of hFOB1.19 cells treated with MSCs-derived exosomes were detected by cell count kit-8 (CCK-8) assay. The effect of MSCs-derived exosomes on cell apoptosis was evaluated by flow cytometry. Protein expression levels of apoptosis-related genes in hFOB1.19 cells were detected by Western blot. RESULTS: MSCs differentiated into osteoblasts and lipoblasts under different treatments. Meanwhile, MSCs-derived exosomes exhibited typical elongated morphology after isolation and culture for 1 and 3 days, respectively. Functionally, MSCs-derived exosomes could promote the viability of hFOB1.19 cells, and significantly increase the expression level of GLUT3. In addition, MSCs-derived exosomes remarkably downregulated apoptosis-related genes and decreased apoptosis in hFOB1.19 cells. CONCLUSIONS: MSCs-derived exosomes could promote osteoblast proliferation via inhibiting cell apoptosis, eventually improving osteoporosis.