Objective        To explore the regulatory role of Wnt3a in the differentiation of mouse osteoclasts.       Methods       Cells were divided into a negative control group (blank)

an experimental control group (Ad-GFP transfection)

a positive control group (50 ng/mL RANKL induction)

and an experimental group (Ad-Wnt3a transfection). All the cells were conventionally cultured for 6 d. Tartrate-resistant acid phosphatase (TRAP) staining was applied to observe osteoclast differentiation and maturation

and Western blot analysis was applied to detect the protein expression of TRAP and cathepsin K. Total cellular RNA was extracted after treatment for 3

6 and 9 d

and quantitative real-time PCR was applied to determine the expression of receptor activator of nuclear factor κB (RANK)

TRAP

cathepsin K and matrix metalloproteinase (MMP)-9.       Results       TRAP staining showed that 50 ng/ml RANKL could successfully induce RAW264.7 cells into multinucleated cells (nuclear≥10). A few multinucleated cells (3≤nuclear≤5) were observed in the control group and the Ad-GFP group

and mononuclear cells and few dual-nuclear cells were observed in the Ad-Wnt3a group.       Conclusion        Wnt3a can inhibit the differentiation of RAW264.7 cells into mature osteoclasts.