High-dose PMA with RANKL and MCSF induces THP‑1 cell differentiation into human functional osteoclasts in vitro.

Osteoclasts are large multinuclear cells, which serve role in erosive bone disease. However, it is not possible to separate osteoclasts from cortical bone in order to culture the cells for further experiments. Therefore, a human osteoclast model is required to investigate the underlying mechanism of bone destruction.

TLR4 drives the pathogenesis of acquired cholesteatoma by promoting local inflammation and bone destruction.

Acquired cholesteatoma is a chronic inflammatory disease characterized by both hyperkeratinized squamous epithelial overgrowth and bone destruction. Toll-like receptor (TLR) activation and subsequent inflammatory cytokine production are closely associated with inflammatory bone disease. However, the expression and function of TLRs in cholesteatoma remain unclear.