Figure 1.

Mepazine inhibits RANK ligand (RANKL)-induced osteoclastogenesis independently of mucosa-associated lymphoid tissue lymphoma translocation (MALT1). Bone marrow cells (BMCs) isolated from wild-type (WT) and Malt1 knock-out (KO) mice were stimulated every two days with macrophage-colony stimulating factor (M-CSF) (20 ng/mL) plus RANKL (50 ng/mL) in the presence or absence of mepazine (13 µM). Samples without mepazine were treated with an equal volume (0.1% final concentration) of DMSO as solvent control. The / symbol represents that no RANKL or mepazine was added. At day 9, cells were fixed and stained for tartrate-resistant acid phosphatase (TRAP). Microscopic analysis shows the appearance of very large multinucleated TRAP-positive cells (=typical for osteoclasts) after M-CSF plus RANKL treatment. Scale bar represents 100 µm. Results are representative of three independent experiments.