Dynamic mitophagy trajectories hallmark brain aging

Area of Science:

• Neuroscience
• Cell Biology
• Aging Research

Background:

• Basal mitophagy is crucial for cellular health, but its regulation during healthy brain aging is poorly understood.
• Previous studies established mitophagy reporter mice but lacked cell-type and region-specific aging data in the brain.

Purpose of the Study:

• To comprehensively analyze mitophagy and macroautophagy dynamics in diverse aging brain cell types.
• To identify region- and cell-specific changes in autophagy during healthy mammalian brain aging.
• To determine if midlife represents a critical inflection point for brain autophagy regulation.

Main Methods:

• Longitudinal study using mitophagy reporter mice.
• Spatiotemporal analysis of mitophagy and macroautophagy dynamics.
• Single-cell level mapping of autophagy in various brain cell types (neurons, microglia, astrocytes).

Main Results:

• Mitophagy significantly increases in the cerebellum and hippocampus but not the prefrontal cortex (PFC) during midlife.
• Macroautophagy decreases in the hippocampus and PFC, while remaining stable in the cerebellum.
• Emergent lysosomal heterogeneity and accumulation of acidified lysosomes were observed in the aging brain.
• Midlife was identified as a critical inflection point for autophagy regulation.

Conclusions:

• Autophagy regulation in the aging mammalian brain is complex, cell-specific, and dynamic.
• Midlife changes in brain autophagy may underlie region-specific vulnerability and resilience to aging.
• Findings provide a framework for understanding brain aging and potential therapeutic targets for neurodegenerative diseases.