Exosomes are tiny vesicles secreted by cells, can be important mediators of cell-to-cell communication, and play unique roles in disease diagnosis and treatment. Osteoporosis is a metabolic bone disease with high incidence in the elderly, characterized by low bone mineral density and deterioration of bone microstructure. Highly specific diagnostic methods capable of identifying early-stage osteoporosis are urgently needed. In this study, serum exosomes were comprehensively enriched and characterized. In total, 179 exosomal proteins were identified using liquid chromatography-mass spectrometry, most of which are involved in important biological processes such as defense and immune responses. Through label free quantification of serum exosomes, 188, 224, and 185 proteins were identified in the normal, osteopenia, and osteoporosis groups, respectively. Quantitative results also showed that 17 proteins were significantly (p <0.05) dysregulated in the osteoporosis and osteopenia groups, including Integrin β 3, Integrin α 2 β 1, Talin 1, and Gelsolin. This study provides potential molecular markers for osteoporosis studs and will contributes to the elucidating the pathogenesis of osteoporosis.
Keywords: biomarkers; exosomes; osteopenia; osteoporosis; proteomics.