[Notch2 activation promotes osteoclastogenesis under high glucose concentration in vitro]

Area of Science:

• Bone biology
• Cell signaling
• Diabetic complications

Background:

• Diabetes mellitus is associated with altered bone metabolism.
• Osteoclastogenesis, the formation of bone-resorbing cells, is crucial for bone remodeling.
• The role of Notch2 signaling in high glucose-induced osteoclastogenesis is not fully understood.

Purpose of the Study:

• To investigate the impact of high glucose on receptor activator of nuclear factor kappa B ligand (RANKL)-induced osteoclastogenesis and Notch2 expression.
• To explore the effect of Notch2 activation on osteoclastogenesis in high glucose conditions.

Main Methods:

• Bone marrow macrophages (BMMs) were cultured and exposed to varying high glucose concentrations.
• Osteoclast formation was assessed using tartrate-resistant acid phosphatase (TRAP) assay.
• Notch2 gene expression was quantified via real-time PCR, and its activation's effect on osteoclastogenesis was studied using Western blotting and TRAP staining.

Main Results:

• High glucose concentrations (20 and 40 mmol/L) significantly reduced osteoclast numbers and Notch2 gene expression compared to mannitol controls.
• Activation of Notch2 signaling (ICN2-OE) in high glucose conditions significantly increased osteoclast numbers compared to controls.
• Notch2 signaling activation appears to promote osteoclastogenesis under high glucose conditions.

Conclusions:

• High glucose may inhibit osteoclastogenesis through mechanisms that reduce Notch2 expression.
• Notch2 signaling activation can overcome the inhibitory effects of high glucose on osteoclastogenesis.
• Targeting Notch2 signaling may offer therapeutic potential for managing bone abnormalities in diabetes.