ABSTRACT
Objective To explore that whether apoptotic bodies released by osteoclasts mediate osteogenic activity. Methods The osteoclasts were induced from mouse (n = 10) bone marrow monocytes in vitro, and were identified by tartrate resistant acid phosphatase (TRAP) staining, F-actin, and DAPI double labeling immunofluorescence. The Co- culture system of osteoclasts and mouse osteoblasts MC-3T3E1 was established. The apoptosis of osteoclasts was analyzed by DNA fragment ELISA. Immunoblotting of apoptotic body markers was investigated. Real-time PCR analysis of bone formation markers was tested. MiRNA expression profiling of apoptotic body was identisfied. Results Alendronate (ALN) 100 μmol/L induced osteoclast apoptosis and caused apoptotic body release from osteoclasts. The expression of C3b and annexin V protein was enhanced by ALN; the expression of C3b in osteoclasts was negatively correlated with the activity of osteoblasts; the microarray screening of apoptotic body showed that miR-30a was correlated with bone formation markers and serum alkaline phosphatase (ALP). Conclusion Osteoclast-derived apoptotic body miR-30a can inhibit the activity of osteoblasts. Apoptotic body may participate in the dialogue between osteoclasts and osteoblasts.