Tartrate-resistant acid phosphatase augments the bone anabolic response to mechanical loading in male mice

Area of Science:

• Bone Biology
• Skeletal Physiology
• Mechanobiology

Background:

• Tartrate-resistant acid phosphatase (TRAP) is key in osteoclasts and bone remodeling.
• TRAP deficiency causes skeletal impairments like osteopetrosis.
• The role of TRAP in bone's response to mechanical loading is not fully understood.

Purpose of the Study:

• To investigate the role of TRAP in the anabolic response to mechanical loading.
• To compare bone adaptation to mechanical strain in TRAP knockout and wild-type mice.

Main Methods:

• Axial tibial loading was applied to 16-week-old male TRAP knockout (TRAP-/-) and wild-type (WT) littermate control mice.
• Micro-computed tomography (micro-CT) was used to analyze bone structural changes.
• Serum alkaline phosphatase levels were measured.

Main Results:

• WT mice showed enhanced periosteal area, trabecular bone volume, thickness, and number after loading.
• TRAP-/- mice exhibited impaired cortical bone formation and reduced trabecular bone formation.
• TRAP-/- mice displayed fewer epiphyseal growth plate bony bridges, indicating a blunted mechanoadaptive response.

Conclusions:

• TRAP is essential for mediating bone adaptation to mechanical loading.
• TRAP deficiency leads to impaired bone mechanoadaptation, potentially involving osteoblastic activity.
• Understanding TRAP's function in mechanoadaptation may inform therapies for bone diseases.