Mitochondrial dysfunction in mesenchymal stem cells impairs osteogenesis in radiation-induced bone injury via...

Area of Science:

• Biomedical Science
• Cell Biology
• Regenerative Medicine

Background:

• Mitochondrial dysfunction in mesenchymal stem cells (MSCs) is linked to impaired osteogenesis and bone loss after radiation therapy.
• The precise mechanisms underlying radiation-induced bone injury and MSC dysfunction require further investigation.

Purpose of the Study:

• To elucidate the role of Fis1 in regulating mitochondrial dynamics and MSC osteogenesis in the context of radiation-induced bone injury.
• To explore the potential of targeting Fis1 as a therapeutic strategy for mitigating bone loss after radiation treatment.

Main Methods:

• Investigated the expression and function of Fis1 in MSCs following radiation exposure.
• Analyzed mitochondrial dynamics, including fission and fragmentation, using various cellular assays.
• Assessed osteogenic differentiation capacity of MSCs and bone loss in an in vivo model.
• Examined the calcium-calcineurin-NFATc1 signaling pathway involved in Fis1 regulation.

Main Results:

• Radiation exposure increases Fis1 expression, leading to excessive mitochondrial fission and fragmentation in MSCs.
• Impaired mitochondrial function (reduced oxidative phosphorylation, ATP synthesis, and antioxidant defense) was observed.
• The calcium-calcineurin-NFATc1 pathway was identified as a key regulator of Fis1 expression post-radiation.
• Inhibition of Fis1 ameliorated mitochondrial fragmentation, enhanced MSC osteogenesis, and reduced bone loss in vivo.

Conclusions:

• Fis1 plays a critical role in mediating mitochondrial dysfunction and impaired osteogenesis in MSCs following radiation exposure.
• Targeting Fis1 demonstrates significant therapeutic potential for treating radiation-induced bone injury by preserving MSC function and promoting bone repair.