Basic Microglial Functions and How They Go Awry in Neurodegenerative Disease

Area of Science:

• Neuroimmunology
• Cellular Biology
• Neurodegenerative Diseases

Background:

• Microglia are crucial for brain health, performing immune and repair functions.
• In neurodegenerative diseases, microglia lose their homeostatic capabilities.
• Their functions, like phagocytosis and immune signaling, can become detrimental.

Purpose of the Study:

• To review the transition of microglial function from competence to dysfunction in neurodegeneration.
• To examine the mechanisms underlying microglial failure.
• To discuss potential therapeutic strategies targeting dysfunctional microglia.

Main Methods:

• Literature review focusing on microglial roles in brain health and disease.
• Analysis of case studies including Alzheimer's disease, inherited microgliopathies, and Aicardi-Goutières syndrome.
• Examination of genetic and environmental factors influencing microglial function.

Main Results:

• Microglial dysfunction manifests as metabolic exhaustion, lysosomal overload, inflammatory gain of function, or unresponsiveness.
• These failures contribute to disease progression in conditions like Alzheimer's disease.
• Genetic and environmental factors converge to induce "microglial incompetence."

Conclusions:

• Dysfunctional microglia play a significant role in the pathogenesis of various neurodegenerative diseases.
• Understanding the mechanisms of microglial failure is key to developing new treatments.
• Emerging strategies aim to restore or replace dysfunctional microglia to combat neurodegeneration.