A Concomitant Muscle Injury Does Not Worsen Traumatic Brain Injury Outcomes in Mice

Mujun Sun, Rhys D. Brady, Chris van der Poel, Danielle Apted, Bridgette D. Semple, Jarrod E. Church, Terence J. O'Brien, Stuart J. McDonald, Sandy R. Shultz

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9 Citations (Scopus)

Abstract

Traumatic brain injury (TBI) often involves multitrauma in which concurrent extracranial injury occurs. We previously demonstrated that a long bone fracture exacerbates neuroinflammation and functional outcomes in mice given a TBI. Whether other forms of concomitant peripheral trauma that are common in the TBI setting, such as skeletal muscle injury, have similar effects is unknown. As such, here we developed a novel mouse multitrauma model by combining a closed-skull TBI with a cardiotoxin (CTX)-induced muscle injury to investigate whether muscle injury affects TBI outcomes. Adult male mice were assigned to four groups: sham-TBI + sham-muscle injury (SHAM); sham-TBI + CTX-muscle injury (CTX); TBI + sham-muscle injury (TBI); TBI + CTX-muscle injury (MULTI). Some mice were euthanized at 24 h post-injury to assess neuroinflammation and cerebral edema. The remaining mice underwent behavioral testing after a 30-day recovery period, and were euthanized at 35 days post-injury for post-mortem analysis. At 24 h post-injury, both TBI and MULTI mice had elevated edema, increased expression of GFAP (i.e., a marker for reactive astrocytes), and increased mRNA levels of inflammatory chemokines. There was also an effect of injury on cytokine levels at 35 days post-injury. However, the TBI and MULTI mice did not significantly differ on any of the measures assessed. These initial findings suggest that a concomitant muscle injury does not significantly affect preclinical TBI outcomes. Future studies should investigate the combination of different injury models, additional outcomes, and other post-injury time points.

Original languageEnglish
Article number1089
Number of pages11
JournalFrontiers in Neurology
Volume9
DOIs
Publication statusPublished - 11 Dec 2018

Keywords

  • cardiotoxin
  • cytokines
  • neuroinflammation
  • polytrauma
  • weight-drop

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