Age-associated neuronal micronuclei formation and transfer to microglia

Area of Science:

• Neuroscience
• Immunology
• Cell Biology

Background:

• Microglia are central nervous system immune cells responding to neuronal signals.
• Neuronal damage can release nuclear contents, potentially activating microglia.
• Neuronal micronuclei (MNs) mediate microglial changes during development.

Purpose of the Study:

• To investigate if neuronal MNs transfer to microglia in the aging brain.
• To understand the impact of MN incorporation on aged microglia.
• To explore novel neuron-to-microglia communication pathways in aging.

Main Methods:

• Analysis of neuronal nuclear envelope fragility and MN formation in aged brains.
• Observation of MN transfer from neurons to microglia.
• Characterization of microglial morphology and gene expression after MN uptake.

Main Results:

• Neuronal nuclear envelopes become fragile and form MNs during aging.
• Neuronal MNs are transferred to and incorporated by adjacent microglia.
• Microglia incorporating MNs exhibit altered morphology (extended processes) and gene expression changes.

Conclusions:

• Neuronal MN formation and transfer to microglia occur during brain aging.
• MN incorporation alters aged microglia characteristics and function.
• This suggests a previously unrecognized neuron-to-microglia communication mechanism in aging via MNs.