Mild traumatic brain injury (mTBI) results in impairment of brain metabolism, which is propagated by mitochondrial dysfunction in the brain. Mitochondrial dysfunction has been identified as a pathobiological therapeutic target to quell cellular dyshomeostasis. Further, therapeutic approaches targeting mitochondrial impairments, such as mild mitochondrial uncoupling, have been shown to alleviate behavioral alterations after TBI. To examine how mild mitochondrial uncoupling modulates acute mitochondrial outcomes in a military-relevant model of mTBI, we utilized repeated blast overpressure of 11 psi peak overpressure to model repeated mild blast traumatic brain injury (rmbTBI) in rats followed by assessment of mitochondrial respiration and mitochondrial-related oxidative damage at 2 days post-rmbTBI. Treatment groups were administered 8 or 80 mg/kg MP201, a prodrug of 2,4 dinitrophenol (DNP) that displays improved pharmacokinetics compared with its metabolized form. Synaptic and glia-enriched mitochondria were isolated using fractionated a mitochondrial magnetic separation technique. There was a consistent physiological response, decreased heart rate, following mbTBI among experimental groups. Although there was a lack of injury effect in mitochondrial respiration of glia-enriched mitochondria, there were impairments in mitochondrial respiration in synaptic mitochondria isolated from the prefrontal cortex (PFC) and the amygdala/entorhinal/piriform cortex (AEP) region. Impairments in synaptic mitochondrial respiration were rescued by oral 80 mg/kg MP201 treatment after rmbTBI, which may be facilitated by increases in complex II and complex IV activity. Mitochondrial oxidative damage in glia-enriched mitochondria was increased in the PFC and hippocampus after rmbTBI. MP201 treatment alleviated elevated glia-enriched mitochondrial oxidative damage following rmbTBI. However, there was a lack of injury-associated differences in oxidative damage in synaptic mitochondria. Overall, our report demonstrates that rmbTBI results in mitochondrial impairment diffusely throughout the brain and mild mitochondrial uncoupling can restore mitochondrial bioenergetics and oxidative balance.
|Number of pages||14|
|Journal||Journal of Neurotrauma|
|State||Published - Nov 1 2023|
Bibliographical noteFunding Information:
The studies were supported by the Medical Technology Enterprise Consortium (MTEC) and BrightFocus through project 20-16-mTBI-005 and by University of Kentucky Neuroscience Research Priority Area pilot award NRPA016. The studies were also supported by COBRE CNS Metabolism grant NIH NIGMS P20 GM148326. WBH was supported by BLR&D Career Development Award IK2 BX004618 from the Department of Veterans Affairs. The contents do not represent the views of the U.S. Department of Veterans Affairs or the United States government.
© W. Brad Hubbard et al., 2023 Published by Mary Ann Liebert, Inc.
- blast injury
- low-level blast
- oxidative stress
ASJC Scopus subject areas
- Clinical Neurology