Intercellular mitochondrial transfer and trans-mitophagy in response to protein import dysfunction.

Intercellular mitochondrial transfer via tunnelling nanotubes enables mitochondrial regeneration and rescue in cells with import dysfunction, involving distinct degradation pathways for different mitochondria.

• Why it matters: Understanding how cells cope with mitochondrial import failure is crucial because such dysfunction impairs energy production, especially in high-demand cells like neurons, contributing to disease.
• What they did: The study examined bidirectional mitochondrial trafficking between cells with defective and functional mitochondria, revealing that damaged mitochondria are degraded via lysosomes, while ROS-producing mitochondria are transferred into neighboring cells and stored in novel "mitochondrial degradation bodies."
• The result: This dual process of TNT-mediated degradation and transfer, termed "trans-mitophagy," promotes mitochondrial regeneration and restores cellular energy balance, offering insights into cellular rescue mechanisms.