Initial responses of osteoblasts derived from human alveolar bone to various compressive forces

Area of Science:

• Biomedical Engineering
• Orthodontics
• Cell Biology

Background:

• Orthodontic forces induce mechanical stress, significantly influencing alveolar bone remodeling.
• Osteoblasts are key players in bone formation and osteoclastogenesis during remodeling.

Purpose of the Study:

• To investigate the effects of continuous compressive force (CF) on human primary osteoblasts (HOBs).
• To assess changes in HOBs' proliferation, apoptosis, and expression of IL-6 and CXCL8 under CF.

Main Methods:

• Human primary osteoblasts were subjected to continuous compressive force (1-4 g cm(-2)) for up to 72 hours.
• Cell viability and proliferation assessed via MTT assay.
• mRNA expression of KI67, BAX, BCL2, IL6, and CXCL8 analyzed by RT-PCR; protein levels of IL-6 and CXCL8 measured by multiplexed bead immunoassay.

Main Results:

• CF significantly decreased HOB viability and proliferation in a time- and force-dependent manner.
• CF inhibited KI67 mRNA expression but did not alter BAX or BCL2 mRNA levels.
• CF upregulated IL6 and CXCL8 mRNA expression, but paradoxically reduced their protein release.

Conclusions:

• Continuous compressive force negatively impacts osteoblast function, affecting proliferation and viability.
• The differential regulation of IL-6 and CXCL8 at mRNA and protein levels suggests complex cellular responses to mechanical stress.
• Findings provide insights into the cellular mechanisms underlying orthodontic tooth movement and alveolar bone remodeling.