Somatic autophagy of axonal mitochondria in ischemic neurons.

Abstract

Mitophagy protects against ischemic neuronal injury by eliminating damaged mitochondria, but it is unclear how mitochondria in distal axons are cleared. We find that oxygen and glucose deprivation-reperfusion reduces mitochondrial content in both cell bodies and axons. Axonal mitochondria elimination was not abolished in Atg7 fl/fl ;nes-Cre neurons, suggesting the absence of direct mitophagy in axons. Instead, axonal mitochondria were enwrapped by autophagosomes in soma and axon-derived mitochondria prioritized for elimination by autophagy. Intriguingly, axonal mitochondria showed prompt loss of anterograde motility but increased retrograde movement upon reperfusion. Anchoring of axonal mitochondria by syntaphilin blocked neuronal mitophagy and aggravated injury. Conversely, induced binding of mitochondria to dynein reinforced retrograde transport and enhanced mitophagy to prevent mitochondrial dysfunction and attenuate neuronal injury. Therefore, we reveal somatic autophagy of axonal mitochondria in ischemic neurons and establish a direct link of retrograde mitochondrial movement with mitophagy. Our findings may provide a new concept for reducing ischemic neuronal injury by correcting mitochondrial motility.

• Authors: Yanrong Zheng, Xiangnan Zhang, Xiaoli Wu, Lei Jiang, Anil Ahsan, Shijia Ma, Ziyu Xiao, Feng Han, Zheng-Hong Qin, Weiwei Hu, Zhong Chen
• Journal: The Journal of cell biology (J Cell Biol) Vol. 218 Issue 6 Pg. 1891-1907 (06 03 2019) ISSN: 1540-8140 [Electronic] United States
• PMID: 30979799 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2019 Zheng et al.

Chemical References

• Atg7 protein, mouse
• Membrane Proteins
• Nerve Tissue Proteins
• Snph protein, mouse
• Ubiquitin-Protein Ligases
• parkin protein
• Autophagy-Related Protein 7

Topics

• Animals
• Autophagy-Related Protein 7 (physiology)
• Axons (metabolism, pathology)
• Brain Ischemia (metabolism, pathology)
• Cerebral Cortex (metabolism, pathology)
• Membrane Proteins (genetics, metabolism)
• Mice
• Mice, Knockout
• Mitochondria (metabolism, pathology)
• Mitophagy
• Nerve Tissue Proteins (genetics, metabolism)
• Neurons (metabolism, pathology)
• Ubiquitin-Protein Ligases (physiology)