The Correlation Between Ferroptosis of Brain Tissue and Neu-rological Function Deficit after Traumatic Brain Injury

Background: Traumatic brain injury (TBI) is a critical condition that significantly endangers hu-man health. Investigating the mechanisms underlying secondary injury in TBI can facilitate early intervention and treatment strategies. The metabolism of intracellular iron is pivotal in the sec-ondary injury process following TBI, with ferroptosis identified as a contributing factor. However, research exploring the relationship between the extent of ferroptosis and the severity of neuro-logical deficits across various TBI models is still limited. Objective: This study seeks to examine the association between ferroptosis in brain tissues and neurological impairments in TBI models with differing injury severities, thereby providing a theoretical framework for understanding the mechanisms and standardizing treatment approaches for TBI. Methods: 36 Male Sprague-Dawley rats were randomly assigned to four groups: a sham group, a mild TBI group (mTBI), a mild-moderate TBI group (mmTBI), and a severe TBI group (sTBI). A rat model of TBI with var-ying injury levels was established using the Feeney free-fall impact method. Neurological function deficits were assessed using the modified Neurological Severity Score (mNSS). Magnetic reso-nance imaging (MRI), transmission electron microscopy (TEM), and Prussian blue staining were utilized to examine iron deposition and ferroptosis in the cortical regions of the rat brains. Western blot analysis was conducted to evaluate the expression of ferroptosis-related molecular markers, and the correlation between mNSS scores and these markers was analyzed. Results: 1) MRI scans indicated that, in comparison to the sham group, the TBI groups displayed elevated signals in the T2WI and T2*WI sequences, signifying brain injury, edema, and hemorrhage. T2*WI revealed diminished signals surrounding the injured areas, indicating iron deposition. 2) TEM analysis revealed that neurons in the TBI group exhibited morphological alterations, including mitochon-drial atrophy, membrane thickening, and partial rupture of the outer membrane. 3) Prussian blue staining demonstrated a progressive increase in iron-positive cells correlating with TBI severity. 4) Western blot results indicated that the expression levels of ferroptosis-related proteins (FTH1 and GPX4) were significantly lower in the mmTBI and sTBI groups compared to the sham group. 5) MDA levels were markedly elevated in the TBI groups, and mNSS scores increased with the se-verity of injury. Correlation analysis revealed a significant negative correlation between mNSS scores and the expression of ferroptosis inhibitors FTH1 and GPX4, alongside a positive correlation with MDA levels. Conclusion: Iron deposition and ferroptosis occur in brain tissue following TBI, and they are closely linked to the severity of neurological impairment.