RANKL drives autophagy and osteoclast differentiation via ROS-mediated HIF-1α down-regulation
10.16016/j.2097-0927.202502048
- VernacularTitle:RANKL通过ROS介导HIF-1α下调促进自噬和破骨细胞分化
- Author:
Songtao LI
1
;
Jing SUN
;
Tongwei CHU
Author Information
1. 陆军军医大学(第三军医大学)第二附属医院骨科
- Keywords:
HIF-1α;
autophagy;
osteoclast differentiation;
reactive oxygen species
- From:
Journal of Army Medical University
2025;47(8):816-825
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the molecular mechanism by which receptor activator of nuclear factor-κB ligand(RANKL)regulates autophagy and osteoclast differentiation through the ROS-HIF-1α signaling axis.Methods Mouse monocytic/macrophage RAW264.7 cells were randomly divided into control group,RANKL group,and 3 combined intervention groups,that is,RANKL+CQ group(intervention with autophagy inhibitor,CQ),RANKL+FG-4592 group(intervention with HIF-1α stabilizer,FG-4592),and RANKL+NAC group(intervention with ROS scavenger,NAC).The number of mature multinucleated osteoclasts was quantitatively detected with tartrate-resistant acid phosphatase(TRAP)staining;the protein levels of HIF-1α and LC3 were detected by Western blotting and the mRNA levels of osteoclast differentiation-related genes(TRAP,Cath K and MMP-9)were analyzed by qRT-PCR;autophagy flux and activity were observed by adenovirus mRFP-GFP-LC3 labeling system combined with confocal laser microscopy;and the production of intracellular reactive oxygen species(ROS)was measured by DCFH-DA probe.Results Compared with the control group,the RANKL group obtained significantly increased number of TRAP-positive multinucleated osteoclasts(P<0.05),up-regulated mRNA levels of osteoclast differentiation-related genes,activated autophagy pathway,as evidenced by the increased LC3-Ⅱ/LC3-Ⅰ ratio(P<0.05)and number of autophagic lysosomes(P<0.05),elevated intracellular ROS generation(P<0.05),and down-regulated HIF-1α protein level(P<0.05).NAC intervention significantly inhibited intracellular ROS accumulation(P<0.05),reversed the lowered expression of HIF-1α protein(P<0.05),decreased the LC3-Ⅱ/LC3-Ⅰ ratio(P<0.05)and autophagy flux and activity(P<0.05),and reduced expression levels of osteoclast differentiation-related genes and the number of mature osteoclasts(P<0.05).In the RANKL+FG-4592 group,HIF-1α protein level was significantly increased(P<0.05),autophagy activation was inhibited[with decreased LC3-Ⅱ/LC3-Ⅰ ratio(P<0.05)and autophagy flux and activity(P<0.05)],and the expression of osteoclast differentiation-related genes and number of mature osteoclasts were decreased(P<0.05)when compared with the RANKL group.While CQ treatment resulted in inhibited autophagy flux and activity(P<0.05),declined expression levels of osteoclast differentiation-related genes,and reduced number of mature osteoclasts(P<0.05).Conclusion RANKL activates autophagy through ROS-mediated down-regulation of HIF-1α,and thereby promotes osteoclast differentiation.
