Extracellular Vesicles of Stem Cells to Prevent BRONJ

Area of Science:

• Biomedical research
• Regenerative medicine
• Cell biology

Background:

• Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a serious condition with unclear pathogenesis and treatment options.
• Zoledronic acid (ZOL), a bisphosphonate, is implicated in BRONJ development.
• Extracellular vesicles (EVs) from mesenchymal stem cells (MSC-EVs) are investigated for therapeutic potential in various diseases.

Purpose of the Study:

• To investigate the therapeutic effects of MSC-EVs on zoledronic acid-induced bisphosphonate-related osteonecrosis of the jaw (BRONJ).
• To evaluate the impact of MSC-EVs on cellular senescence and inflammatory responses in BRONJ models.
• To assess MSC-EVs' role in promoting bone regeneration and angiogenesis in BRONJ.

Main Methods:

• In vitro: Zoledronic acid (ZOL) treatment of bone marrow cells and fibroblasts, followed by MSC-EV administration.
• In vivo: A rat model of BRONJ induced by ZOL and tooth extraction, with and without MSC-EV treatment.
• Histological and molecular analyses, including senescence markers (β-galactosidase, p21, pRB), inflammatory cytokines, stem cell markers (Bmi1, Hmga2), and vascular endothelial growth factor (VEGF).

Main Results:

• In vitro, MSC-EVs reduced the number of senescent cells and suppressed senescence-associated genes (p21, pRB) and inflammatory cytokines.
• In vivo, MSC-EV treatment promoted socket healing in BRONJ rats, with reduced senescent cells and inflammation.
• MSC-EVs increased expression of stem cell markers (Bmi1, Hmga2) and vascular endothelial growth factor (VEGF), indicating enhanced angiogenesis and regeneration.

Conclusions:

• MSC-EVs effectively prevent ZOL-induced cellular senescence and reduce inflammation in BRONJ.
• MSC-EV administration promotes wound healing, angiogenesis, and bone regeneration, offering a potential therapeutic strategy for BRONJ.
• MSC-EVs mitigate BRONJ by preventing cellular senescence and chronic inflammation while enhancing regenerative processes.