罗沙司他通过稳定 HIF-1α 和激活 Wnt/β-连环蛋白信号通路促进成骨细胞分化，并预防雌激素缺乏引起的骨丢失。

BACKGROUND: Osteoporosis is a very common skeletal disorder that increases the risk of fractures. However, the treatment of osteoporosis is challenging. Hypoxia-inducible factor-1α (HIF-1α) plays an important role in bone metabolism. Roxadustat is a novel HIF stabilizer, and its effects on bone metabolism remain unknown. This study aimed to investigate the effects of roxadustat on osteoblast differentiation and bone remodeling in an ovariectomized (OVX) rat model. METHODS: In vitro, primary mouse calvarial osteoblasts were treated with roxadustat. Alkaline phosphatase (ALP) activity and extracellular matrix mineralization were assessed. The mRNA and protein expression levels of osteogenic markers were detected. The effects of roxadustat on the HIF-1α and Wnt/β-catenin pathways were evaluated. Furthermore, osteoblast differentiation was assessed again after HIF-1α expression knockdown or inhibition of the Wnt/β-catenin pathway. In vivo, roxadustat was administered orally to OVX rats for 12 weeks. Then, bone histomorphometric analysis was performed. The protein expression levels of the osteogenic markers HIF-1α and β-catenin in bone tissue were detected. RESULTS: In vitro, roxadustat significantly increased ALP staining intensity, enhanced matrix mineralization and upregulated the expression of osteogenic markers at the mRNA and protein levels in osteoblasts compared with the control group. Roxadustat activated the HIF-1α and Wnt/β-catenin pathways. HIF-1α knockdown or Wnt/β-catenin pathway inhibition significantly attenuated roxadustat-promoted osteoblast differentiation. In vivo, roxadustat administration improved bone microarchitecture deterioration and alleviated bone loss in OVX rats by promoting bone formation and inhibiting bone resorption. Roxadustat upregulated the protein expression levels of the osteogenic markers, HIF-1α and β-catenin in the bone tissue of OVX rats. CONCLUSION: Roxadustat promoted osteoblast differentiation and prevented bone loss in OVX rats. The use of roxadustat may be a new promising strategy to treat osteoporosis.

背景：骨质疏松症是一种非常常见的骨骼疾病，会增加骨折的风险。然而，骨质疏松症的治疗具有挑战性。缺氧诱导因子-1α（HIF-1α）在骨代谢中发挥重要作用。罗沙司他是一种新型的 HIF 稳定剂，其对骨代谢的影响尚不清楚。本研究旨在探讨罗沙司他对去卵巢（OVX）大鼠模型中成骨细胞分化和骨重塑的影响。

方法：在体外，用罗沙司他处理原代小鼠颅骨成骨细胞。评估碱性磷酸酶（ALP）活性和细胞外基质矿化。检测成骨标志物的 mRNA 和蛋白表达水平。评估罗沙司他对 HIF-1α 和 Wnt/β-catenin 通路的影响。此外，在 HIF-1α 表达敲低或抑制 Wnt/β-catenin 通路后，再次评估成骨细胞分化。在体内，用罗沙司他对 OVX 大鼠进行口服给药 12 周。然后进行骨组织形态计量学分析。检测骨组织中成骨标志物 HIF-1α 和 β-catenin 的蛋白表达水平。

结果：在体外，与对照组相比，罗沙司他显著增加了成骨细胞的 ALP 染色强度，增强了基质矿化，并上调了成骨标志物的 mRNA 和蛋白水平表达。罗沙司他激活了 HIF-1α 和 Wnt/β-catenin 通路。HIF-1α 敲低或 Wnt/β-catenin 通路抑制显著减弱了罗沙司他促进成骨细胞分化的作用。在体内，罗沙司他通过促进骨形成和抑制骨吸收来改善 OVX 大鼠的骨微结构恶化和骨丢失。罗沙司他上调了 OVX 大鼠骨组织中成骨标志物、HIF-1α 和 β-catenin 的蛋白表达水平。

结论：罗沙司他促进了 OVX 大鼠成骨细胞分化并防止了骨丢失。罗沙司他的使用可能是治疗骨质疏松症的一种新的有前途的策略。