It protects the brain... but can also damage it. Find out why researchers are so fascinated by microglia.
Microglia are resident immune cells in the brain, representing around 5-10% of brain cells. Derived from the yolk sac during embryonic development, it constantly patrols the nervous tissue in search of abnormalities.
Its mission: to spot the slightest sign of danger, eliminate cellular debris, neutralize microbes and alert other immune cells in the event of aggression.
A true sentinel of the brain, it plays an essential role in its protection and proper functioning.Ask ChatGPT
Under normal circumstances, microglia actively contribute to brain balance. It eliminates dead cells, sculpts useless neuronal connections during development, and supports neurons by secreting growth factors.
But as soon as an imbalance is detected - infection, lesion or abnormal accumulation of proteins - it is activated. This activation is accompanied by a change of form, behavior and function: microglia migrate to the injured areas, release pro-inflammatory molecules, and reinforce the local immune response.
This mechanism is essential in the short term, but becomes problematic if it takes hold over time.
In diseases such as Alzheimer's, Parkinson's or multiple sclerosis, microglia remain abnormally active for months or even years.
The result is chronic inflammation, disruption of neuronal function and, in some cases, aggravation of lesions rather than repair.
Understanding how to regulate this microglial activation is now a central challenge in developing new therapies for neurodegenerative diseases.
To better understand brain diseases, scientists are increasingly turning their attention to microglia.
This immune cell, long considered secondary, is in fact essential to the balance of the nervous system, but also to its dysregulation.
Here are the two big questions driving current research:
How does microglia change its role?
In a healthy brain, microglia protects and supports neurons. But under the effect of stress, aging or certain diseases, it can change and adopt toxic behavior.
Researchers are seeking to understand the signals that trigger this switch, and how to prevent it from becoming chronic.
🔗 Medical challenge: limit brain inflammation and slow the progression of diseases such as Alzheimer's or Parkinson's.
Can microglia be reprogrammed to repair the brain?
Some studies show that microglia could also help rebuild damaged neuronal circuits.
Scientists are exploring how to reactivate this restorative potential, without causing side effects.
🔗 Medical challenge: stimulating regeneration in multiple sclerosis or after brain trauma.Ask ChatGPT
Researchers at the University of California at Irvine have created human microglia genetically modified (CRISPR) to produce the enzyme neprilysin - a destroyer of amyloid plaques - only where they accumulate.
Injected into mice, these cells: Dramatically reduce amyloid deposits, Protect neurons and synapses, Reduce inflammation, And reduce markers of neuronal damage
Concrete hope: a "living", targeted and adaptable therapy, raising hopes of a new class of tailor-made microglial treatments.
Nasal Foralumab: soothing overactive microglia
Biotech Tiziana Life Sciences has tested intranasal administration of an anti-CD3 antibody (Foralumab) in patients with moderate Alzheimer's disease.
Microglial PET-scans (TSPO) show a significant decrease in microglial activation after three months of treatment.
Concrete hope: reduce brain inflammation via a non-invasive, synergistic route, complementing current treatments.
