Fig 4.

Umb suppresses RANKL-induced Akt signaling pathway. (A) BMMs were pretreated with the control (DMSO) or Umb (200 μM) for 1 h and then stimulated with RANKL (100 ng/mL) for the indicated time. Whole-cell lysates underwent western blot analysis with the indicated MAPK antibodies. β-actin served as the internal control. (B) Representation of the ratio of phosphorylated Akt to total Akt. ^***P < 0.001 versus the control at indicated times. (C) BMMs were infected with retroviruses expressing pMX-IRES-EGFP (pMX) and pMX-CA-Akt-EGFP. The infected BMMs were cultured with or without Umb (200 μM) in the presence of M-CSF (30 ng/mL) and RANKL (100 ng/mL) for 4 days. Thereafter, the cells were fixed and stained with TRAP solution. (D) TRAP-positive MNCs counted as osteoclasts.