Exogenous bone sialoprotein improves extraction socket healing in Ibsp knockout and wild-type mice

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Oral and Maxillofacial Surgery

Background:

• Bone sialoprotein (BSP) is a key extracellular matrix protein crucial for bone formation and mineralization.
• Mice lacking BSP (Ibsp knockout) display impaired alveolar bone development and healing.
• The potential of exogenous BSP to restore defective alveolar bone healing remains largely unexplored.

Purpose of the Study:

• To investigate whether exogenous bone sialoprotein (BSP) can rescue defective alveolar bone healing in Ibsp knockout mice.
• To evaluate the effects of native rat BSP (nBSP) and recombinant rat BSP (rBSP) on bone regeneration.
• To compare the efficacy of BSP administration in both Ibsp knockout and wild-type mice.

Main Methods:

• Native rat BSP (nBSP) or recombinant rat BSP (rBSP) in collagen gel was applied to molar extraction sockets in Ibsp knockout and wild-type mice.
• Bone healing was assessed at various time points using micro-computed tomography, histology, and immunohistochemistry.
• Gene expression analysis was performed to understand the molecular mechanisms underlying BSP's effects.

Main Results:

• Both nBSP and rBSP significantly increased bone volume fraction and bone mineral density in Ibsp knockout mice at 14 days post-procedure.
• Exogenous BSP also enhanced bone healing in wild-type mice, increasing bone volume and density.
• Recombinant BSP (rBSP) modulated genes related to cell signaling, extracellular matrix, mineralization, and osteoblast/osteoclast activity, while nBSP had minimal effects on gene expression.

Conclusions:

• Exogenous bone sialoprotein (BSP) effectively rescues defective alveolar bone healing in Ibsp knockout mice.
• BSP administration enhances bone healing in both deficient and normal physiological states.
• These findings highlight BSP as a potential therapeutic agent for improving bone quantity and quality in socket healing.