Targeting MDK alleviates bone loss via dual regulation of osteogenic differentiation and inflammatory cytokine...

Area of Science:

• Bone biology and metabolic diseases
• Molecular mechanisms of osteoporosis
• Therapeutic targets for bone loss

Background:

• Growth factors regulate bone homeostasis and disease.
• Identifying specific factors like midkine (MDK) is crucial for treating bone metabolic diseases.
• Postmenopausal osteoporosis involves complex molecular signaling pathways.

Purpose of the Study:

• To investigate the role of midkine (MDK) in postmenopausal osteoporosis.
• To evaluate the therapeutic potential of a midkine inhibitor (iMDK) for estrogen deficiency-induced bone loss.

Main Methods:

• Clinical data analysis and ovariectomized mouse models to assess MDK levels.
• In vitro studies using recombinant MDK protein to examine effects on osteogenic differentiation.
• Transcriptome analysis to elucidate MDK's molecular pathways (PI3K/AKT, NF-κB).

Main Results:

• Elevated serum MDK levels and negative correlation with bone mineral density in osteoporosis patients and mice.
• iMDK treatment mitigated bone loss, enhanced bone formation, and reduced inflammatory factors.
• Recombinant MDK inhibited osteogenic differentiation and modulated PI3K/AKT and NF-κB signaling pathways, increasing inflammatory cytokines (IL-6, TNF-α, IL-1β).

Conclusions:

• Midkine (MDK) is implicated in postmenopausal osteoporosis pathogenesis.
• MDK inhibition represents a potential therapeutic strategy for osteoporosis.
• The small molecule inhibitor iMDK shows promise as a therapeutic candidate for treating bone loss.