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Traumatic brain injury (TBI) causes a primary insult and initiates a secondary injury cascade. The mechanisms underlying the secondary injury are multifactorial and may include the aberrant expression of long non-coding RNA (lncRNA) post-TBI. Here, lncRNA microarray analysis was performed to profile the altered lncRNAs in the rat hippocampus after TBI. A total of 271 lncRNA probe sets and 1046 messenger RNA (mRNA) probe sets were differentially expressed after TBI. Gene ontology analysis showed that the main components of the most significantly changed categories were inflammation, DNA transcription, apoptosis, and necroptosis. Additionally, the pathway analysis and the pathway relation network revealed correlated pathways mainly involving inflammation, cell cycle, and apoptosis. A co-expression network of these aberrantly expressed lncRNAs and mRNAs was further constructed to predict the potential function of individual lncRNAs. Sub-co-expression networks were formed for the top three lncRNAs: NR_002704, ENSRNOT00000062543, and Zfas1. Thus, our study demonstrated differential expression of a series of lncRNAs in the rat hippocampus after TBI, which may be correlated with post-TBI physiological and pathological processes. The findings also may provide novel targets for further investigation of both the molecular mechanisms underlying TBI and potential therapeutic interventions.

Summary: Aims: Ferroptosis, a new form of iron‐dependent programmed cell death, has been shown to be involved in a range of diseases. However, the role of ferroptosis in traumatic brain injury (TBI) has yet to be elucidated. We aimed to investigate whether ferroptosis is induced after TBI and whether the inhibition of ferroptosis would protect against traumatic brain injury in a controlled cortical impact injury (CCI) mouse model. Methods: After establishing the TBI model in mice, we determined the biochemical and morphological changes associated with ferroptosis, including iron accumulation with Perl's staining, neuronal cell death with Fluoro‐Jade B (FJB) staining, iron metabolism dysfunction with Western blotting, reactive oxygen species (ROS) accumulation with malondialdehyde (MDA) assays, and shrunken mitochondria with transmission electron microscopy. Furthermore, a specific inhibitor of ferroptosis, ferrostatin‐1(fer‐1), was administrated by cerebral ventricular injection after CCI. We used cresyl violet (CV) staining to assess lesion volume, along with the Morris water maze and beam walk test to evaluate long‐term outcomes. Results: TBI was followed by iron accumulation, dysfunctional iron metabolism, the upregulation of ferroptosis‐related genes, reduced glutathione peroxidase (GPx) activity, and the accumulation of lipid‐reactive oxygen species (ROS). Three days (d) after TBI, transmission electron microscopy (TEM) confirmed that the mitochondria had shrunk a typical characteristic of ferroptosis. Importantly, the administration of Fer‐1 by cerebral ventricular injection significantly reduced iron deposition and neuronal degeneration while attenuating injury lesions and improving long‐term motor and cognitive function. Conclusion: This study demonstrated an effective method with which to treat TBI by targeting ferroptosis. [ABSTRACT FROM AUTHOR]

Objective The role of autophagy in moderate hypothermia in posttraumatic brain injury (post-TBI) remains elusive. In this study, we evaluated the protective role of autophagy in post-TBI moderate hypothermia. Methods Adult male Sprague-Dawley rats were randomly divided into 3 groups ( n = 36/group): TBI with hypothermia group (sham), TBI with hypothermia and a single intracerebroventricular injection of saline (saline, 5 μL), and TBI with hypothermia and a single intracerebroventricular injection of 3-methyladenine (600 nmol, diluted in 0.9% saline to a final volume of 5 μL). All rats, except those in the behavioral tests, were killed at 24 hours after fluid percussion TBI. Immunohistochemistry staining, western blot, and transmission electron microscopy were performed to assess changes in apoptosis and autophagy after injection of 3-methyladenine. Motor function (beam-walk test) and spatial learning/memory (Morris water maze) were assessed on postoperative days 1–5 and 11–15, respectively. Results Our results showed downregulation of the expression level of microtubule-associated protein 1 light chain 3 and Beclin-1, aggravation of behavioral outcome, and increase of apoptosis. Conclusion Our results suggest that the autophagy pathway is involved in the neuroprotective effect of post-TBI hypothermia and negative modulation of apoptosis may be 1 possible mechanism. [ABSTRACT FROM AUTHOR]