Zhou Bingna, Hu Jing, Yu Yuanyuan, Sun Lei, Wang Yanye, Zhang Qian, Jiang Yan, Wang Ou, Xing Xiaoping, Xia Weibo, Wang Luyao, Zhang Ge, Li Mei
Department of Endocrinology, Key Laboratory of Endocrinology, National Health and Family Planning Commission, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Law Sau Fai Institute for Advancing Translational Medicine in Bone and Joint Diseases (TMBJ), School of Chinese Medicine, Hong Kong Baptist University, Hong Kong SAR, China.
J Cachexia Sarcopenia Muscle. 2025 Jun;16(3):e13831. doi: 10.1002/jcsm.13831.
The Wnt/β-catenin pathway and its bone-specific inhibitor, sclerostin, play important roles in skeletal development and homeostasis. The humanized sclerostin antibody, romosozumab, can significantly increase bone mineral density (BMD) of patients with osteoporosis, but it may also increase cardiovascular adverse events, particularly in male patients. We try to investigate the effects of novel aptamers targeting the sclerostin loop3 on the skeleton and muscle of orchiectomized (ORX) mice.
After 12 weeks of ORX surgery, mice were randomly assigned to receive treatment with sclerostin aptamers (Apc001OA or Apc001OA-d6), alendronate (ALN), teriparatide (PTH 1-34) or phosphate-buffered saline (PBS). After 12 weeks of treatment, skeletal and muscle properties and safety indicators were evaluated in detail.
Treatment with Apc001OA and Apc001OA-d6 significantly increased trabecular BMD at the femur by +11.9% and +17.1%, improved parameters of bone microarchitecture (BV/TV by +84.5% and +106.8%), bone strength (maximum load by +30.5% and +31.6%) and bone histological properties (all p < 0.05 vs. PBS group). The therapeutic effects were similar among Apc001OA, Apc001OA-d6, ALN and PTH 1-34 groups (all p > 0.05). After treatment with Apc001OA or Apc001OA-d6, serum sclerostin levels significantly decreased by 25.0% and 24.9% (p < 0.05 vs. PBS group). The expression levels of key genes in the Wnt/β-catenin pathway, Ctnnb1 and Lef1 significantly increased by 2.4- and 3.4-fold in the Apc001OA group and by 2.5- and 3.5-fold in the Apc001OA-d6 group (p < 0.05 vs. PBS group), indicating that the aptamers improved bone properties through activating Wnt/β-catenin pathway. Apc001OA and Apc001OA-d6 significantly improved rotarod latency (p < 0.05 vs. PBS group) of ORX mice, and Apc001OA-d6 could increase forelimb grip strength. Apc001OA, Apc001OA-d6 and PTH 1-34 improved histological properties of muscle in ORX mice. No lesions or pathological changes were observed in the heart, aortic roots, liver, spleen, lungs or kidneys. Immunohistochemistry revealed no abnormal staining of interleukin 6 (IL-6) and tumour necrosis factor-α (TNF-α) in the heart. There was no significant difference in serum concentrations of cardiac functional biomarkers, including creatine kinase-MB (CK-MB), cardiac troponin I (cTnI), B-type natriuretic peptide (BNP) and inflammatory mediators (IL-6 and TNF-α) across all groups, indicating that Apc001OA and Apc001OA-d6 had no adverse cardiovascular effects in ORX mice.
The novel aptamers Apc001OA and Apc001OA-d6, targeting sclerostin loop3, could significantly increase BMD and improve bone microarchitecture, bone biomechanics, muscle function and histological properties of muscle and bone in ORX mice, without adverse cardiovascular effects. These aptamers may serve as potential agents for treating osteoporosis and sarcopenia in men.
Wnt/β-连环蛋白信号通路及其骨特异性抑制剂硬化蛋白在骨骼发育和稳态中发挥重要作用。人源化硬化蛋白抗体罗莫单抗可显著提高骨质疏松症患者的骨矿物质密度（BMD），但也可能增加心血管不良事件，尤其是在男性患者中。我们试图研究靶向硬化蛋白环3的新型适配体对去势（ORX）小鼠骨骼和肌肉的影响。
在进行ORX手术12周后，将小鼠随机分为接受硬化蛋白适配体（Apc001OA或Apc001OA-d6）、阿仑膦酸钠（ALN）、特立帕肽（PTH 1-34）或磷酸盐缓冲盐水（PBS）治疗的组。治疗12周后，详细评估骨骼和肌肉特性以及安全指标。
用Apc001OA和Apc001OA-d6治疗可使股骨小梁骨密度分别显著增加11.9%和17.1%，改善骨微结构参数（骨体积分数分别增加84.5%和106.8%）、骨强度（最大负荷分别增加30.5%和31.6%）和骨组织学特性（与PBS组相比，所有p<0.05）。Apc001OA、Apc001OA-d6、ALN和PTH 1-34组之间的治疗效果相似（所有p>0.05）。用Apc001OA或Apc001OA-d6治疗后，血清硬化蛋白水平显著降低25.0%和24.9%（与PBS组相比，p<0.05）。Wnt/β-连环蛋白信号通路中的关键基因Ctnnb1和Lef1的表达水平在Apc001OA组中显著增加2.4倍和3.多倍，在Apc001OA-d6组中增加2.5倍和3.5倍（与PBS组相比，p<0.05），表明适配体通过激活Wnt/β-连环蛋白信号通路改善骨特性。Apc001OA和Apc001OA-d6显著改善了ORX小鼠的转棒试验潜伏期（与PBS组相比，p<0.05），并且Apc001OA-d6可增加前肢握力。Apc001OA、Apc001OA-d6和PTH 1-34改善了ORX小鼠肌肉的组织学特性。在心脏、主动脉根部、肝脏、脾脏、肺或肾脏中未观察到病变或病理变化。免疫组织化学显示心脏中白细胞介素6（IL-6）和肿瘤坏死因子-α（TNF-α）无异常染色。所有组中心肌功能生物标志物，包括肌酸激酶-MB（CK-MB）、心肌肌钙蛋白I（cTnI）、B型利钠肽（BNP）和炎症介质（IL-6和TNF-α）的血清浓度无显著差异，表示Apc001OA和Apc001OA-d6对ORX小鼠无心血管不良影响。
靶向硬化蛋白环3的新型适配体Apc001OA和Apc001OA-d6可显著增加ORX小鼠的骨密度，改善骨微结构、骨生物力学、肌肉功能以及肌肉和骨骼的组织学特性，且无心血管不良影响。这些适配体可能成为治疗男性骨质疏松症和肌肉减少症的潜在药物。
