Researchers identify how inflammation spreads through the brain after injury

March 14, 2017

Researchers have identified a new mechanism by which inflammation can spread throughout the brain after injury. This mechanism may explain the widespread and long-lasting inflammation that occurs after traumatic brain injury, and may play a role in other neurodegenerative diseases.

The findings were published today in a study in the Journal of Neuroinflammation.

This new understanding has the potential to transform how brain inflammation is understood, and, ultimately, how it is treated. The researchers showed that microparticles derived from brain inflammatory cells are markedly increased in both the brain and the blood following experimental traumatic brain injury (TBI). These microparticles carry pro-inflammatory factors that can activate normal immune cells, making them potentially toxic to brain neurons. Injecting such microparticles into the brains of uninjured animals creates progressive inflammation at both the injection site and eventually in more distant sites.

Research has found that neuroinflammation often goes on for years after TBI, causing chronic brain damage. The researchers say that the microparticles may play a key role in this process.

Chronic inflammation has been increasingly implicated in the progressive cell loss and neurological changes that occur after TBI. These inflammatory microparticles may be a key mechanism for chronic, progressive brain inflammation and may represent a new target for treating brain injury.

The researchers on the paper include four University of Maryland School of Medicine researchers: Alan Faden, Stephen R. Thom, Bogdan A. Stoica, and David Loane.

"These results potentially provide a new conceptual framework for understanding brain inflammation and its relationship to brain cell loss and neurological deficits after head injury, and may be relevant for other neurodegenerative disorders such as Alzheimer disease in which neuroinflammation may also play a role," said Dr. Faden. "The idea that brain inflammation can trigger more inflammation at a distance through the release of microparticles may offer novel treatment targets for a number of important brain diseases."

The researchers studied mice, and found that in animals who had a traumatic brain injury, levels of microparticles in the blood were much higher. Because each kind of cell in the body has a distinct fingerprint, the researchers could track exactly where the microparticles came from. The microparticles they looked at in this study are released from cells known as microglia, immune cells that are common in the brain. After an injury, these cells often go into overdrive in an attempt to fix the injury. But this outsized response can change protective inflammatory responses to chronic destructive ones.

The findings have important potential clinical implications. The researchers say that microparticles in the blood have the potential to be used as a biomarker - a way to determine how serious a brain injury may be. This could help guide treatment of the injuries, whose severity is often difficult to gauge.

They also found that exposing the inflammatory microparticles to a compound called PEG-TB could neutralize them. This opens up the possibility of using that compound or others to treat TBI, and perhaps even other neurodegenerative diseases.
-end-


University of Maryland School of Medicine

Related Traumatic Brain Injury Articles from Brightsurf:

Point-of-care biomarker assay for traumatic brain injury
Intracranial abnormalities on CT scan in patients with traumatic brain injury (TBI) can be predicted by glial fibrillary acidic protein (GFAP) levels in the blood.

Long-studied protein could be a measure of traumatic brain injury
WRAIR scientists have recently demonstrated that cathepsin B, a well-studied protein important to brain development and function, can be used as biomarker, or indicator of severity, for TBI.

Reducing dangerous swelling in traumatic brain injury
After a traumatic brain injury (TBI), the most harmful damage is caused by secondary swelling of the brain compressed inside the skull.

Blue light can help heal mild traumatic brain injury
Daily exposure to blue wavelength light each morning helps to re-entrain the circadian rhythm so that people get better, more regular sleep which was translated into improvements in cognitive function, reduced daytime sleepiness and actual brain repair.

Dealing a therapeutic counterblow to traumatic brain injury
A team of NJIT biomedical engineers are developing a therapy which shows early indications it can protect neurons and stimulate the regrowth of blood vessels in damaged tissue.

Predictors of cognitive recovery following mild to severe traumatic brain injury
Researchers have shown that higher intelligence and younger age are predictors of greater cognitive recovery 2-5 years post-mild to severe traumatic brain injury (TBI).

Which car crashes cause traumatic brain injury?
Motor vehicle crashes are one of the most common causes of TBI-related emergency room visits, hospitalizations and deaths.

Traumatic brain injury and kids: New treatment guidelines issued
To help promote the highest standards of care, and improve the overall rates of survival and recovery following TBI, a panel of pediatric critical care, neurosurgery and other pediatric experts today issued the third edition of the Brain Trauma Foundation Guidelines for the Management of Pediatric Severe TBI.

Addressing sleep disorders after traumatic brain injury
Amsterdam, NL, December 10, 2018 - Disorders of sleep are some of the most common problems experienced by patients after traumatic brain injury (TBI).

Rutgers researchers discover possible cause for Alzheimer's and traumatic brain injury
Rutgers researchers discover a possible cause for Alzheimer's and traumatic brain injury, and the new mechanism may have also led to the discovery of an effective treatment.

Read More: Traumatic Brain Injury News and Traumatic Brain Injury Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.