Department of Orthopaedics, Xijing Hospital, The Fourth Military Medical University, Xi'an, 710032, China.
Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China.
Biochem Biophys Res Commun. 2018 May 15;499(3):648-654. doi: 10.1016/j.bbrc.2018.03.205. Epub 2018 Mar 31.
Bone homeostasis is maintained by a dynamic balance between osteoblastic bone formation and osteoclastic bone resorption. The receptor activator of nuclear-κB ligand (RANKL) is essential for the function of the bone-resorbing osteoclasts, and targeting RANKL has been proved highly successful in osteoporosis patients. This study aimed to design a novel vaccine targeting RANKL and evaluate its therapeutic effects in OVX-induced bone loss model. Anti-RANKL vaccine was generated by incorporating the unnatural amino acid p-nitrophenylalanine (pNOPhe) into selected sites in the murine RANKL (mRANKL) molecule. Specifically, mutation of a single tyrosine residue Tyr (Y234) or Tyr (Y240) of mRANKL to pNOPhe (thereafter named as YpNOPhe or YpNOPhe) induced a high titer antibody response in mice, whereas no significant antibody response was observed for the wild type mRANKL (WT mRANKL). The antiserum induced by YpNOPhe or YpNOPhe could efficiently prevent osteoclastogenesis in vitro. Moreover, immunization with YpNOPhe or YpNOPhe could also prevent OVX-induced bone loss in mice, suggesting that selected pNOPhe-substituted mRANKL may pave the way for creating a novel vaccine to treat osteoporosis.
骨稳态是通过成骨细胞骨形成和破骨细胞骨吸收之间的动态平衡来维持的。核因子-κB 配体受体激活剂（RANKL）对于破骨细胞的骨吸收功能至关重要，靶向 RANKL 已被证明在骨质疏松症患者中非常有效。本研究旨在设计一种针对 RANKL 的新型疫苗，并评估其在去卵巢诱导的骨丢失模型中的治疗效果。抗 RANKL 疫苗是通过将非天然氨基酸对硝基苯丙氨酸（pNOPhe）掺入鼠 RANKL（mRANKL）分子的选定部位而产生的。具体而言，mRANKL 中单个酪氨酸残基 Tyr（Y234）或 Tyr（Y240）突变为 pNOPhe（此后称为 YpNOPhe 或 YpNOPhe）可诱导小鼠产生高滴度的抗体反应，而野生型 mRANKL（WT mRANKL）则没有明显的抗体反应。YpNOPhe 或 YpNOPhe 诱导的抗血清可有效抑制体外破骨细胞形成。此外，用 YpNOPhe 或 YpNOPhe 免疫也可以预防去卵巢诱导的小鼠骨丢失，这表明选择的 pNOPhe 取代 mRANKL 可能为治疗骨质疏松症创造一种新型疫苗铺平了道路。
