Abstract Background and Aims In recent years, hypoxia-inducing factor prolyl hydroxylase inhibitors (HIF-PHIs) have been widely used in the treatment of renal anemia, bringing a revolutionary breakthrough in the treatment of anemia in CKD patients. However, HIF-PHIs acts on a variety of cells and regulates the expression of multiple target genes. Some studies have reported that HIF-PHIs plays an important role in regulating bone metabolism and promoting the differentiation and calcification of osteoblasts, but its influence on osteoclasts remains controversial. This study intends to explore the effect of roxadustat, a representative drug of HIF-PHIs, on osteoclasts. Method Bone marrow mononuclear cells (BMMCs) from 6-8 weeks old male C57BL/6 wild mice were extracted and induced to differentiate into osteoclasts using macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor-κB ligand (RANKL). Meanwhile, lipopolysaccharide (LPS) was used to simulate the inflammatory environment in CKD patients. According to the experimental group, different concentrations of roxadustat (0 μM, 2.5 μM, 5 μM, 10μM) were added simultaneously. When osteoclast induction reached day 6, mRNA was extracted for transcriptome sequencing and bioinformatics analysis. Results As shown in Table 1, different concentrations of roxadustat were given to primary bone marrow monocytes under both conditions, and there were 3 biological replicates for each sample. The reproducibility scatter plot showed that the data in each group had good repeatability (Fig. 1), and the heat map for basic difference analysis of each sample was shown in Fig. 2. The trend analysis results of the two groups were shown in Fig. 3. BMMCs group and LPS stimulated group showed two upward trends, respectively. KEGG enrichment analysis of these two upward trends showed that HIF-1, MAPK, PI3K-Akt, NF-κB and osteoclast differentiation pathways were significantly enriched in both groups. It is suggested that roxadustat can promote osteoclast differentiation and increase inflammatory response with the increase of roxadustat concentration. The enrichment analysis of the two groups showed that there was no significant enrichment pathway. Conclusion We explored the differentiation of osteoclasts under normal conditions and osteoclast differentiation under simulated inflammation in CKD patients respectively. Transcriptomic analysis results showed that HIF-1, MAPK, PI3K-Akt, NF-κB and osteoclast differentiation pathways were significantly enriched with the increase of roxadustat concentration. It is suggested that the use of roxadustat may promote bone destruction and increase the risk of inflammatory response.
Read full abstract