Mitochondrial transfer mediates endothelial cell engraftment through mitophagy

Area of Science:

• Vascular Biology
• Cellular Bioenergetics
• Regenerative Medicine

Background:

• Ischaemic diseases pose a significant global health burden.
• Endothelial cell (EC) transplantation is a promising vascular therapy.
• EC engraftment often requires co-transplantation with mesenchymal stromal cells (MSCs), complicating clinical use.

Purpose of the Study:

• To elucidate the mechanism by which MSCs facilitate EC engraftment.
• To explore novel strategies for enhancing EC engraftment in vascular repair.

Main Methods:

• Investigated intercellular mitochondrial transfer between MSCs and ECs using tunnelling nanotubes.
• Developed a method for artificial mitochondrial transplantation into ECs.
• Utilized genetic manipulation (PINK1-Parkin pathway ablation) to assess mitochondrial roles.
• Assessed EC bioenergetics and functional vessel formation in ischaemic tissues.

Main Results:

• MSCs transfer mitochondria to ECs through tunnelling nanotubes, crucial for EC engraftment.
• Blocking mitochondrial transfer impairs EC engraftment.
• Artificial mitochondrial transplantation enhances EC bioenergetics and promotes functional vessel formation without MSCs.
• Transplanted mitochondria trigger mitophagy and do not integrate into the host mitochondrial network.
• PINK1-Parkin pathway is essential for the enhanced engraftment observed after mitochondrial transfer.

Conclusions:

• Mesenchymal stromal cells facilitate endothelial cell engraftment via mitochondrial transfer.
• Targeted mitochondrial transplantation presents a potential cell-free therapy for vascular regeneration.
• Understanding mitochondrial dynamics offers new therapeutic avenues for ischaemic diseases.