✍️ Author: Dr Eleni Christoforidou
🕒 Approximate reading time: 4 minutes
The brain, with its intricate mesh of neurons and glial cells, remains an organ of profound complexity. Among the brain's protective mechanisms, the blood-brain barrier (BBB) stands out. While primarily functioning as a protective shield, its involvement in neuroinflammation is gradually emerging as a topic of great interest to neuroscientists.
The BBB is a semi-permeable border that separates the circulating blood from the brain's extracellular fluid. Comprising endothelial cells, pericytes, and astrocyte end-feet, the BBB regulates the passage of substances to ensure that only specific molecules can access the central nervous system.
Neuroinflammation refers to the inflammatory response within the brain or spinal cord. While short-term inflammation can be protective, chronic inflammation often contributes to various neurological diseases like multiple sclerosis or Alzheimer's.
BBB Permeability: In health, the BBB restricts most immune cells from entering the CNS. However, during neuroinflammation, this barrier becomes compromised. Increased permeability allows immune cells, such as T-cells or macrophages, to infiltrate, exacerbating inflammation.
Transport of Inflammatory Mediators: The compromised BBB can also facilitate the movement of inflammatory mediators like cytokines or chemokines between the blood and the brain.
Endothelial Cell Activation: The BBB's endothelial cells can be activated by inflammatory stimuli, further recruiting immune cells to the inflammation site.
A disrupted BBB not only amplifies inflammation but can also:
Understanding the BBB's role in neuroinflammation highlights its potential as a therapeutic target. Strategies to reinforce the BBB or reduce its permeability could mitigate the adverse effects of neuroinflammation.
The blood-brain barrier, once seen as a mere protective structure, is now recognised for its dynamic involvement in neuroinflammation. As research unfolds, targeting the BBB could pave the way for innovative therapeutic strategies in treating neuroinflammatory conditions.