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Updated: Sep 11, 2025
Electromagnetic Controlled Closed-Head Model of Mild Traumatic Brain Injury in Mice
Published on: September 28, 2022
Microglial xCT Is a Novel Therapeutic Target for Traumatic Brain Injury in Model Mice
Kenichi Matsuda1, Yugo Kato2, Yusuke Okawara1
1Division of Emergency and Disaster Medicine, Department of Surgery, Faculty of Medicine, Tottori University, Yonago 683-8504, Japan.
Background:
Brain injury accompanied by hemorrhage, such as cerebral contusion or intracerebral hemorrhage, leads to the accumulation of activated microglia around the lesion. In addition, microglia at the site of injury can act either damagingly or protectively, depending on the time; for instance, it is damaging in the acute phase and protective in the chronic phase. Moreover, during brain injury, glutamate-induced excitotoxicity leads to secondary damage to neurons. However, the source of glutamate released from cells remains largely unknown. Our previous studies have revealed that cystine/glutamate antiporter system xc - (xc-) in microglia is an important source of glutamate release and that the induction of expression of xCT, a component molecule of xc-, is vital.
Methods:
We investigated the effect of microglial xCT on traumatic brain injury using xCT-deficient mice.
Results:
In cultured microglia supplemented with crude brain extract and the affected side of the brain injury model accompanied by hemorrhage, the expression level of xCT was increased on the affected side, and induction was observed mainly in microglia. In addition, EAAT2 levels on the affected side decreased. On the affected side, the number of CD80-positive microglia was significantly increased, and the xCT expression rate was elevated in CD80-positive cells. Assuming that xCT in microglia is important, we investigated xCT-deficient mice and microglia-specific xCT knockdown mice and found that the extent of brain damage was milder than in wildtype mice. The proportion of CD80-positive microglia was lower than that in wild-type mice. Assuming that microglial xCT could be a therapeutic target, we performed an experiment using the xCT inhibitor SSZ administered intraperitoneally. The extent of damage was narrowed, and the ratio of CD80-positive microglia was reduced, demonstrating a therapeutic effect.
Conclusion:
Thus, microglial xCT is important in the pathology of brain injury accompanied by bleeding and is considered a promising therapeutic target.
Insights
Microglial cystine/glutamate antiporter system xc- (xc-) contributes to brain injury damage. Inhibiting this system in microglia shows therapeutic potential for brain hemorrhage injuries.
Area of Science:
- Neuroscience
- Immunology
- Pathology
Background:
- Brain injury with hemorrhage activates microglia, which can be damaging or protective.
- Glutamate excitotoxicity causes secondary neuronal damage after brain injury.
- Microglial cystine/glutamate antiporter system xc- (xc-) is a key source of glutamate release.
Purpose of the Study:
- To investigate the role of microglial xCT in traumatic brain injury (TBI) with hemorrhage.
- To evaluate xCT as a potential therapeutic target for TBI.
Main Methods:
- Utilized xCT-deficient mice and microglia-specific xCT knockdown mice.
- Analyzed microglial activation markers (e.g., CD80) and xCT expression.
- Administered an xCT inhibitor (SSZ) to assess therapeutic effects in a TBI model.
Main Results:
- xCT expression was upregulated in microglia following brain injury.
- xCT-deficient mice exhibited reduced brain damage and microglial activation.
- Inhibition of xCT with SSZ ameliorated brain damage and decreased CD80-positive microglia.
Conclusions:
- Microglial xCT plays a significant role in the pathology of brain injury with hemorrhage.
- Targeting microglial xCT presents a promising therapeutic strategy for TBI.
