The HIV protease inhibitor ritonavir blocks osteoclastogenesis and function by impairing RANKL-induced signaling
J. Clin. Invest. Michael W.-H. Wang, et al. 114:206 doi:10.1172/JCI15797 [Go to this article.]

Figure 1
Osteoclastogenesis is impaired by ritonavir but not indinavir. (A) Osteoclasts were generated from bone marrow macrophages stimulated with RANKL and M-CSF for 4 days in the presence of the indicated doses of ritonavir or indinavir. TRAP solution assay quantitation of osteoclast formation shows that the IC₅₀ for ritonavir is near 10 μg/ml. In contrast, cultures exposed to indinavir show no inhibition or enhancement of osteoclast formation. (B) Representative fields of TRAP-stained osteoclasts in the presence of control medium, indinavir (10 μg/ml), and ritonavir (10 μg/ml). Magnification, ×100. (C) Ritonavir dose dependently suppresses osteoclast gene markers determined by RT-PCR analysis of osteoclasts on day 4 culture.