Roxadustat promotes osteoblast differentiation and prevents estrogen deficiency-induced bone loss by stabilizing HIF-1α and activating the Wnt/β-catenin signaling pathway

Abstract

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.

The Bioactive Compounds of Epimedium and Their Potential Mechanism of Action in Treating Osteoporosis: A Network Pharmacology and Experimental Validation Study

“…This indicates that the inhibition of HIF-1α may promote osteoblast proliferation and activity, contributing to an anti-osteoporotic effect. Conversely, Li et al [ 50 ] reported that raloxifene significantly increased the ALP staining intensity in osteoblasts by upregulating the protein expression of HIF-1α and β-catenin in OVX rat bone tissue. This indicates that the anti-osteoporotic effect of raloxifene is associated with the activation of HIF-1α and enhanced osteoblast proliferation, which challenges the findings of Chen et al Given these conflicting outcomes, the role of the HIF-1α signaling pathway in osteogenic activity during osteoporosis treatment requires further investigation.…”

Mechanism of Liuwei Dihuang Pills in treating osteoporosis based on network pharmacology

“…Studies have shown that activating the HIF-1 signaling pathway can improve bone mineral density and promote osteoblast differentiation in OVX rats. [ 22 ] Additionally, HIF-1 is a crucial molecule that mediates bone-vascular interaction, and up-regulating the HIF-1 signaling pathway can promote angiogenesis and alleviate bone loss in ovariectomized (OVX) mice. [ 21 , 23 ] VEGF is a crucial regulator of angiogenesis that plays a significant role in bone metabolism.…”

Construction of Bone Hypoxic Microenvironment Based on Bone-on-a-Chip Platforms

“…In particular, the HIF signaling pathway plays an important role in bone formation during fracture repair. Conditional deletion of HIF-1 or HIF-2 in osteoblasts results in a significant reduction in bone volume, whereas HIF-1 and HIF-2 are over-stabilized by the loss of VHL, leading to increased bone mass and thus changes in bone volume [ 43 , 44 , 45 ].…”