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Analysis of Microglia and Monocyte-derived Macrophages from the Central Nervous System by Flow Cytometry
Published on: June 22, 2017
Monocyte-derived macrophages act as reinforcements when microglia fall short in Alzheimer's disease
Miguel A Abellanas1, Maitreyee Purnapatre1, Chiara Burgaletto1
1Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel.
Abstract:
The central nervous system (CNS) is endowed with its own resident innate immune cells, the microglia. They constitute approximately 10% of the total cells within the CNS parenchyma and act as 'sentinels', sensing and mitigating any deviation from homeostasis. Nevertheless, under severe acute or chronic neurological injury or disease, microglia are unable to contain the damage, and the reparative activity of monocyte-derived macrophages (MDMs) is required. The failure of the microglia under such conditions could be an outcome of their prolonged exposure to hostile stimuli, leading to their exhaustion or senescence. Here, we describe the conditions under which the microglia fall short, focusing mainly on the context of Alzheimer's disease, and shed light on the functions performed by MDMs. We discuss whether and how MDMs engage in cross-talk with the microglia, why their recruitment is often inadequate, and potential ways to augment their homing to the brain in a well-controlled manner.
Insights
Microglia, the brain's immune cells, can become exhausted during neurological diseases like Alzheimer's. Monocyte-derived macrophages (MDMs) are then needed for repair, but their recruitment is often insufficient.
Area of Science:
- Neuroimmunology
- Cellular Biology
- Neurology
Background:
- The central nervous system (CNS) contains resident immune cells called microglia, which maintain homeostasis.
- Microglia act as sentinels but can fail under severe neurological injury or disease.
- Monocyte-derived macrophages (MDMs) are crucial for repair when microglia are insufficient.
Purpose of the Study:
- To examine conditions where microglia fail, particularly in Alzheimer's disease.
- To elucidate the functions of monocyte-derived macrophages (MDMs) in CNS repair.
- To explore MDM-microglia interactions and strategies to improve MDM recruitment.
Main Methods:
- Review of existing literature on microglial function and dysfunction.
- Analysis of cellular mechanisms in neuroinflammation and repair.
- Discussion of potential therapeutic strategies for enhancing MDM homing.
Main Results:
- Microglial failure can result from exhaustion or senescence due to prolonged exposure to hostile stimuli.
- MDMs play a critical role in CNS repair when microglia are compromised.
- Inadequate MDM recruitment is a significant limitation in neurological disease contexts.
Conclusions:
- Understanding microglial limitations is key to addressing neurological damage.
- MDMs offer a potential avenue for therapeutic intervention in CNS diseases.
- Optimizing MDM recruitment presents a promising strategy for enhancing brain repair.

