Platelet-rich plasma inhibits RANKL-induced osteoclast differentiation through activation of Wnt pathway during bone remodeling

Platelet-rich plasma (PRP) is used in the clinic as an autologous blood product to stimulate bone regeneration and chondrogenesis. Numerous studies have demonstrated that PRP affects bone remodeling by accelerating osteoblast formation. With the research perspective focusing on osteoclasts, the present study established a mouse model of mandibular advancement to examine the effect of PRP on osteoclast differentiation induced by modification of the dynamics of the temporomandibular joint (TMJ). The lower incisors of the mice were trimmed by 1 mm and the resultant change in mandibular position during the process of eating induced condylar adaptation to this change. PRP significantly increased the bone mass and decreased osteoclastic activity, in vitro as well as in vivo. Mechanistically, the reduced expression of receptor activator of nuclear factor-κB ligand (RANKL)-induced differentiation marker genes, including nuclear factor of activated T-cells, cytoplasmic 1, c-fos and tartrate-resistant acid phosphatase, and that of the resorptive activity marker genes such as cathepsin k, carbonic anhydrase 2 and matrix metalloproteinase 9, indicated that PRP suppresses RANKL-induced osteoclast differentiation. A microarray analysis revealed that several genes associated with the Wnt pathway were differentially expressed, which indicated the involvement of this pathway in osteoclast differentiation. Furthermore, the activation of the Wnt pathway was verified by reverse transcription-quantitative polymerase chain reaction and immunoblot analysis of Dickkopf-related protein 1 and β-catenin. The results of the present study indicated that PRP inhibits osteoclast differentiation through activation of the Wnt pathway.