Cranial bone marrow-derived monocytes promote neuroinflammation in chronic traumatic brain injury.

Cranial bone marrow-derived monocytes promote neuroinflammation and neurological deficits in chronic traumatic brain injury, especially in older patients.

• Why it matters: Understanding the mechanisms behind long-term neuroinflammation in cTBI is crucial for developing targeted therapies, as current treatments are limited and age-related severity increases.
• What they did: The study combined clinical specimens, cell-tracing, multiomics, animal models, adoptive transfer, and a clinical trial with 40 older cTBI patients to investigate CBM-derived immune cells' role in neuroinflammation.
• The result: Findings show that cTBI causes persistent expansion of inflammatory monocytes/macrophages in CBM, which migrate into the brain and promote neuroinflammation; fenofibrate treatment reduced inflammatory cell infiltration and improved cognitive function.