Hexosamine Biosynthetic Pathway-Derived O-GlcNAcylation Is Critical for RANKL-Mediated Osteoclast Differentiation.

Area of Science:

• Biochemistry
• Cell Biology
• Molecular Biology

Background:

• O-linked-N-acetylglucosaminylation (O-GlcNAcylation) is a nutrient-sensitive post-translational modification.
• O-GlcNAcylation impacts transcription factor activity and cellular processes like differentiation.
• The role of O-GlcNAcylation in osteoclast differentiation was previously unexplored.

Purpose of the Study:

• To investigate the role of O-GlcNAcylation in receptor activator of nuclear factor-kappaB (NF-κB) ligand (RANKL)-mediated osteoclast differentiation.
• To explore O-GlcNAcylation as a potential therapeutic target for osteoclast-related bone diseases.

Main Methods:

• Kinetic transcriptome analysis during RANKL-induced osteoclast differentiation.
• Inhibition of O-GlcNAcylation using the small-molecule inhibitor OSMI-1.
• Gene knockdown of O-GlcNAc transferase (OGT) using shRNA (shOgt).

Main Results:

• Key hexosamine biosynthetic pathway (HBP) genes and global O-GlcNAcylation were upregulated during osteoclast differentiation.
• OSMI-1 treatment inhibited osteoclast differentiation in vitro and in vivo.
• OSMI-1 disrupted the nuclear translocation of NF-κB p65 and NFATc1 by affecting their O-GlcNAcylation.
• OSMI-1 showed synergistic effects with bone-targeted therapy.
• shOgt mimicked the inhibitory effects of OSMI-1 on osteoclastogenesis.

Conclusions:

• O-GlcNAcylation is critical for osteoclast differentiation.
• Targeting O-GlcNAcylation presents a promising therapeutic strategy for osteoclast-activated bone diseases.