Importin-7 promotes tension-induced osteogenesis by regulating RUNX2 nuclear translocation during orthodontic tooth...

Area of Science:

• Biomedical Engineering
• Cell Biology
• Orthodontics

Background:

• Alveolar bone remodeling drives orthodontic tooth movement (OTM).
• Tension-induced osteogenesis is crucial for OTM.
• Importin7 (IPO7), a nuclear transport receptor, is mechanoresponsive but its role in OTM is unknown.

Purpose of the Study:

• Investigate IPO7's role in tension-induced osteogenesis during OTM.
• Elucidate the mechanism by which IPO7 regulates osteogenesis.

Main Methods:

• Cyclic tensile strain application in vitro.
• Rat orthodontic tooth movement (OTM) model in vivo.
• IPO7 knockdown in bone marrow stromal cells (BMSCs).
• Immunoprecipitation (IP) coupled with mass spectrometry (MS).
• Co-immunoprecipitation (co-IP) and immunofluorescence assays.

Main Results:

• IPO7 expression increased with mechanical stretch in vitro and in vivo.
• IPO7 knockdown inhibited tension-induced osteogenesis in BMSCs.
• Mechanical force induced IPO7 translocation to the nucleus.
• IPO7 interacts with RUNX2, a key osteogenic transcription factor.
• IPO7 regulates RUNX2 nuclear localization.

Conclusions:

• IPO7 promotes tension-induced osteogenesis during OTM.
• IPO7 facilitates osteogenesis by controlling RUNX2 nuclear import.
• Targeting IPO7 may enhance alveolar bone remodeling and orthodontic treatment efficacy.