Bone Fracture Enhances Trauma Brain Injury

Area of Science:

• Neuroscience
• Immunology
• Trauma Research

Background:

• Traumatic brain injury (TBI) is a major cause of death and disability globally.
• The secondary phase pathophysiology of TBI requires further investigation.
• Systemic injuries, such as bone fractures (BF), may influence TBI outcomes.

Purpose of the Study:

• To investigate the impact of bone fracture (BF) on TBI.
• To explore the role of high mobility group 1 (HMGB1) protein in BF-induced exacerbation of TBI.
• To evaluate the therapeutic potential of blocking HMGB1 in TBI.

Main Methods:

• Establishment of TBI and TBI + BF mouse models.
• Assessment of neurological severity using behavioral tests (tape removal, corner test).
• Quantification of brain lesion volume and edema.
• Measurement of HMGB1 levels and evaluation of HMGB1 ablation effects.

Main Results:

• Bone fracture significantly worsened neurological deficits, increased brain lesion volume, and exacerbated brain edema in TBI mice.
• HMGB1 levels were significantly elevated in TBI + BF mice, indicating its involvement in secondary TBI.
• Ablation of HMGB1 effectively mitigated the negative effects of BF on TBI outcomes.

Conclusions:

• Bone fracture triggers systemic immune activation, leading to increased HMGB1 levels and aggravated TBI-related inflammation.
• Blocking HMGB1 demonstrates a promising therapeutic approach to reduce inflammation and alleviate secondary TBI severity.
• Targeting HMGB1 represents a feasible strategy for managing TBI, particularly when co-occurring with systemic injuries like bone fractures.