Regulatory mechanism of urolithin B in osteoclastic differentiation of bone marrow-derived macrophages
- VernacularTitle:尿石素B对骨髓来源巨噬细胞向破骨细胞分化的调控机制
- Author:
Xi LUO
1
;
Jianquan CHEN
Author Information
- Keywords: urolithin B; P65; ERK; nuclear factor of activated T cells 1; c-Fos; bone marrow-derived macrophage; osteoclastic differentiation
- From: Chinese Journal of Tissue Engineering Research 2025;29(11):2201-2209
- CountryChina
- Language:Chinese
- Abstract: BACKGROUND:Urolithin B plays an important role in regulating the body's immune response and has antioxidant,anti-cancer and anti-inflammatory properties.Notably,urolithin B has been reported to have inhibitory effects on osteoclast differentiation of Raw 264.7 cells.However,a more comprehensive understanding of its specific mechanism of action in the context of osteoclast differentiation in bone is worth exploring.Systematic research on the regulatory mechanisms of osteoclast overactivation can help to explore new therapeutic targets,screen and develop safer and more effective therapeutic drugs,and provide new ideas to block the overactivation of osteoclasts. OBJECTIVE:By establishing an in vitro osteoclast differentiation model using bone marrow-derived macrophages,to investigate the effect of urolithin B on nuclear factor-κB receptor-activating factor ligand-mediated osteoclast differentiation and to systematically analyze its mechanism of action. METHODS:(1)The safe working concentration of urolithin B was screened by cell counting kit-8 method.(2)Different concentrations of urolithin B(0,12.5,25,and 50 μmol/L)were used to intervene with the osteoclast differentiation of bone marrow-derived macrophages,and the number of osteoclasts and the size of osteocytes were observed using tartrate-resistant acid phosphatase staining.(3)Different concentrations of urolithin B(0,12.5,25,and 50 μmol/L)were used to intervene with the osteoclast differentiation of bone marrow-derived macrophages,and the relative expression levels of osteoclast-specific genes were detected using real-time fluorescence quantitative PCR.(4)The effect of urolithin B on the P65 and ERK signaling pathways of bone marrow-derived macrophages was observed by western blot.(5)The effect of urolithin B on the key transcription factors nuclear factor of activated T cells 1 and c-Fos in the osteoclastic differentiation of bone marrow-derived macrophages was detected by western blot. RESULTS AND CONCLUSION:50 μmol/L or lower concentration of urolithin B had no effect on the proliferation of bone marrow-derived macrophages but significantly inhibited osteoclastic differentiation of bone marrow-derived macrophages.Urolithin B mainly inhibited osteoclastic differentiation of bone marrow-derived macrophages in pre-medium term.Urolithin B down-regulated the relative expression levels of osteoclast specific genes in bone marrow-derived macrophages.50 μmol/L urolithin B inhibited the phosphorylation levels of P65 and ERK in bone marrow-derived macrophages,which led to the inhibition of osteoclast formation.50 μmol/L urolithin B inhibited the expression of key transcription factors nuclear factor of activated T cells 1 and c-Fos in bone marrow-derived macrophages into osteoclasts.To conclude,urolithin B inhibits bone marrow-derived macrophages from differentiating into osteoclasts by suppressing the expression of downstream osteoclastogenic-related signature genes and downregulating the expression of the important osteoclastogenic transcription factors,nuclear factor of activated T cells 1 and c-Fos,via the P65/ERK signaling axis.
