Tetrandrine enhances the ubiquitination and degradation of Syk through an AhR-c-src-c-Cbl pathway and consequently inhibits osteoclastogenesis and bone destruction in arthritis

a RAW264.7 cells (up) and BMMs (down) were treated with indicated compounds in the presence or absence of RANKL (100？ng/mL) for 5 days. The osteoclasts were stained using a TRAP kit according to the manufacture’s protocol. TRAP-positive multinucleated cells (nuclei？≥？3) were counted using an inverted microscope. b BMMs were treated with indicated compounds in the presence or absence of RANKL (100？ng/mL) for 24？h. The cells were harvested and lysed, and the mRNA expressions of TRAP and DC-STAMP were detected by quantitative PCR. The results are representative of three independent experiments. *P？<？0.05, **P？<？0.01 vs. indicated grou