Radiation increases the cellular uptake of exosomes through CD29/CD81 complex formation

Area of Science:

• Cell Biology
• Biomedical Engineering
• Cancer Therapy

Background:

• Exosomes mediate intercellular communication, impacting various pathophysiologic states.
• Mesenchymal stem cells (MSC) and their exosomes show promise in clinical applications.
• Radiation therapy is a key treatment modality, but its interaction with exosome uptake is poorly understood.

Purpose of the Study:

• To investigate the mechanisms by which radiation affects exosome uptake in MSC.
• To elucidate the role of cell surface molecules in radiation-modulated exosome-cell interactions.
• To understand how radiation influences the cellular internalization of exosomes.

Main Methods:

• Examine exosome uptake in MSCs exposed to radiation.
• Analyze cell surface protein colocalization (CD29, CD81) using immunofluorescence.
• Utilize gene knockdown techniques (CD29, CD81) to assess their role in exosome uptake.
• Investigate the involvement of endocytic pathways and reactive oxygen species.

Main Results:

• Radiation significantly increased cellular attachment and uptake of exosomes by MSCs.
• Radiation induced colocalization of integrin CD29 and tetraspanin CD81 on the MSC surface.
• CD29 and CD81 were identified as crucial for both basal and radiation-enhanced exosome uptake.
• Radiation-induced uptake was independent of dynamin2, ROS, and p38 MAPK pathways.

Conclusions:

• Radiation enhances MSC exosome uptake primarily through the CD29/CD81 complex.
• These findings offer critical insights into optimizing combined MSC exosome and radiation therapies.
• Understanding these mechanisms is vital for advancing the clinical use of MSC-derived exosomes in conjunction with radiation.