(A) Experimental strategy. WT OBs and WT BMMs were treated with CM of myotubes from Ctrl, Lmna-KO, or Lmna-KO plus IL-6 Ab for 10 days. (B) Representative images of the cultures treated with CM for 10 days. Scale bar, 100 μm. (C) The quantitative analyses of TRAP+ MNCs per field. The values shown are means ± SD from three different cultures. *P < 0.05, **P < 0.01, significant difference. (D) Real-time PCR analysis of RANKL/OPG expression in OBs treated with CM of Ctrl, Lmna-KO, or Lmna-KO plus IL-6 Ab myotube CM. *P < 0.05, significant difference. The underlying data for this figure can be found in S1 Data. Ab, antibody; BMM, bone marrow macrophage/monocyte; CM, conditioned medium; Ctrl, control; IL, interleukin; KO, knockout; Lmna, lamin A/C gene; NF-κB, nuclear factor κB; MNC, multinucleated cell; OB, osteoblast; OC, osteoclast; OPG, osteoprotegerin; RANKL, receptor activator of NF-κB ligand; TRAP, tartrate-resistant acid phosphatase; WT, wild-type.