Objective  To establish a model of differentiation and maturation of osteoclasts (OCs) in vitro and to explore the effect of CD147 on the differentiation and maturation of OCs.   Methods  Peripheral blood mononuclear cells (PBMCs) were isolated from the fresh blood samples of 10 healthy volunteers

and then OCs were induced by using medium with macrophage colony stimulating factor (M-CSF) and receptor activator of nuclear factor-kappaΒ ligand (RANKL). PBMCs were divided into 3 groups

control group

induction group (RANKL+M-CSF) and blocking group (RANKL+M-CSF+CD147Ab). Expression of CD147 was determined by immunofluorescence staining and flow cytometry

and mRNA levels of CD147 and tartrate-resistant acid phosphatase (TRAP) were detected by Real-time PCR. The differentiation and maturation of OCs were observed by TRAP staining.   Results  CD147 was expressed on the membrane of osteoclast precursor cells (OPCs) in all groups. The average fluorescence intensity (AFI) of OPCs surface was gradually increased in control group (159.55±1.65)

and in induction group in 24 h (171.18±3.46) and 48 h (178.47±4.59) (P0.05)

but was significantly reduced in blocking group in 24 h (117.69±9.01

P0.01). The  TRAP positive cells (nuclei≥3) in the blocking group was significantly lesser and with smaller cell body compared with those in the induction group (P0.01). The mRNA levels of CD147 [(1.393±0.248)

(1.772±0.326)] and TRAP [(1.810±0.398)

(2.608±0.906)] of induction group in 24 and 48 h after the induction were gradually increased in OPCs and were higher than those in the blocking group at corresponding time points（P0.05）. Moreover

the mRNA levels of CD147 was significantly positively correlated to the mRNA levels of CD147 (r=0.833

P0.01).   Conclusion  CD147 is expressed on the membrane of OPCs and involved in the differentiation and maturation of OCs. Inhibiting CD147 expression may result in dysmaturity of OCs.