A TNF receptor loop peptide mimic blocks RANK ligand–induced signaling, bone resorption, and bone loss
Kazuhiro Aoki, … , William C. Horne, Roland Baron
Kazuhiro Aoki, … , William C. Horne, Roland Baron
Published June 1, 2006
Citation Information: J Clin Invest. 2006;116(6):1525-1534. https://doi.org/10.1172/JCI22513.
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Research Article Bone biology

A TNF receptor loop peptide mimic blocks RANK ligand–induced signaling, bone resorption, and bone loss

Abstract

Activating receptor activator of NF-κB (RANK) and TNF receptor (TNFR) promote osteoclast differentiation. A critical ligand contact site on the TNFR is partly conserved in RANK. Surface plasmon resonance studies showed that a peptide (WP9QY) that mimics this TNFR contact site and inhibits TNF-α–induced activity bound to RANK ligand (RANKL). Changing a single residue predicted to play an important role in the interaction reduced the binding significantly. WP9QY, but not the altered control peptide, inhibited the RANKL-induced activation of RANK-dependent signaling in RAW 264.7 cells but had no effect on M-CSF–induced activation of some of the same signaling events. WP9QY but not the control peptide also prevented RANKL-induced bone resorption and osteoclastogenesis, even when TNFRs were absent or blocked. In vivo, where both RANKL and TNF-α promote osteoclastogenesis, osteoclast activity, and bone loss, WP9QY prevented the increased osteoclastogenesis and bone loss induced in mice by ovariectomy or low dietary calcium, in the latter case in both wild-type and TNFR double-knockout mice. These results suggest that a peptide that mimics a TNFR ligand contact site blocks bone resorption by interfering with recruitment and activation of osteoclasts by both RANKL and TNF.

Authors

Kazuhiro Aoki, Hiroaki Saito, Cecile Itzstein, Masaji Ishiguro, Tatsuya Shibata, Roland Blanque, Anower Hussain Mian, Mariko Takahashi, Yoshifumi Suzuki, Masako Yoshimatsu, Akira Yamaguchi, Pierre Deprez, Patrick Mollat, Ramachandran Murali, Keiichi Ohya, William C. Horne, Roland Baron

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Figure 7

WP9QY inhibits the increased osteoclastogenesis and bone loss induced by ovariectomy or low dietary calcium.

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WP9QY inhibits the increased osteoclastogenesis and bone loss induced by...
The effect of WP9QY on in vivo bone density was determined in ovariectomized mice (A and B) or mice fed a low-calcium diet (C and D). Mice were treated with WP9QY (2.1 mg/kg/d continuous infusion for ovariectomized mice; 9 mg/kg by injection every 3 hours for the low-dietary-calcium mice) or vehicle. (A) Vertebrae from sham-operated mice or ovariectomized mice treated with WP9QY or vehicle were stained for mineralized bone by the von Kossa method with the van Giesson modification. WP9QY (2.1 mg/kg/d) significantly inhibited the OVX-induced decrease of cancellous bone. (B and C) BMD of the proximal tibiae from ovariectomized mice (B) and from mice maintained on the low-calcium diet (C) was measured by dual energy X-ray absorptiometry (DEXA) and pQCT, respectively. WP9QY inhibited the decrease in BMD induced by both ovariectomy and by low-calcium diet (n = 5; ##P < 0.01 versus vehicle-treated sham group; **P < 0.01 versus vehicle-treated OVX group; #P < 0.05 versus normal-calcium group; *P < 0.01 versus untreated low-calcium group). (D) The 3-dimensional structure of the trabecular bone was examined by micro–computed tomography (μCT), as described in Methods. The amount of trabecular bone in the animals maintained on the low-calcium diet without treatment was markedly less that the amount of trabecular bone in animals maintained on the normal-calcium diet. Treatment with WP9QY (9 mg/kg) prevented the loss of trabecular bone.