Li Peiran, Li Yanxi, Wang Xuejiu, Fan Zhipeng
Department of Oral and Maxillofacial Surgery Beijing Stomatological Hospital, School of Stomatology, Capital Medical University Beijing China.
Department of Implantology Beijing Stomatological Hospital, School of Stomatology, Capital Medical University Beijing China.
FASEB Bioadv. 2025 Sep 3;7(8):e70045. doi: 10.1096/fba.2025-00130. eCollection 2025 Aug.
Previous studies reported the pro-osteogenic ability of L-Tryptophan (L-Trp) and Calcium-Sensing RCeceptor (CaSR) respectively. Recent researchers found L-Trp could activate CaSR. Therefore, this study investigated the osteogenic mechanisms of L-Trp through CaSR activation. Using in vivo and in vitro models, we evaluated L-Trp's effects on bone formation and osteoblast activity. Levo-Trp solution was injected into the temporomandibular joint of 3-week-old mice, and the mandibular development was observed by Micro-CT at 6 weeks of age. The pre-osteoblast cell line MC3T3-E1 cells were stimulated by L-Trp in vitro, and their proliferation, migration, and osteogenic ability were detected by CCK8 assay, alizarin red staining, etc. Transcriptome sequencing was used to investigate the underlying mechanism of L-Trp stimulation and validated by qPCR and Western blot analyses. Local injection of 0.5% L-Trp in juvenile mice significantly increased mandibular bone mineral density. In vitro, L-Trp enhanced MC3T3-E1 pre-osteoblast proliferation, migration, and differentiation, with upregulated osteogenic markers () and mineralization. CaSR antagonism (NPS-2143) abolished these effects, confirming CaSR's pivotal role. Transcriptome sequencing revealed L-Trp activation of the focal adhesion pathway, characterized by increased , and expression. These findings established L-Trp as a CaSR-dependent osteogenic enhancer, mediated via the focal adhesion pathway.
先前的研究分别报道了L-色氨酸（L-Trp）和成钙素受体（CaSR）的促骨生成能力。最近的研究人员发现L-Trp可以激活CaSR。因此，本研究通过激活CaSR来探究L-Trp的成骨机制。我们使用体内和体外模型评估了L-Trp对骨形成和成骨细胞活性的影响。将左旋色氨酸溶液注射到3周龄小鼠的颞下颌关节中，并在6周龄时通过显微CT观察下颌骨发育情况。体外使用L-Trp刺激前成骨细胞系MC3T3-E1细胞，并通过CCK8测定、茜素红染色等方法检测其增殖、迁移和成骨能力。利用转录组测序研究L-Trp刺激的潜在机制，并通过qPCR和蛋白质免疫印迹分析进行验证。在幼年小鼠中局部注射0.5%的L-Trp可显著提高下颌骨矿物质密度。在体外，L-Trp增强了MC3T3-E1前成骨细胞的增殖、迁移和分化，同时上调了成骨标志物（）和矿化作用。CaSR拮抗剂（NPS-2143）消除了这些作用，证实了CaSR的关键作用。转录组测序显示L-Trp激活了粘着斑通路，其特征是、和表达增加。这些发现确立了L-Trp作为一种依赖CaSR的成骨增强剂，通过粘着斑通路介导。
