Systematic Review of Traumatic Brain Injury and the Impact of Antioxidant Therapy on Clinical Outcomes

Acutely blocking excessive mitochondrial fission prevents chronic neurodegeneration after traumatic brain injury

Progression of acute traumatic brain injury (TBI) into chronic neurodegeneration is a major health problem with no protective treatments. Here, we report that acutely elevated mitochondrial fission after TBI in mice triggers chronic neurodegeneration persisting 17 months later, equivalent to many human decades. We show that increased mitochondrial fission after mouse TBI is related to increased brain levels of mitochondrial fission 1 protein (Fis1) and that brain Fis1 is also elevated in human TBI. Pharmacologically preventing Fis1 from binding its mitochondrial partner, dynamin-related protein 1 (Drp1), for 2 weeks after TBI normalizes the balance of mitochondrial fission/fusion and prevents chronically impaired mitochondrial bioenergetics, oxidative damage, microglial activation and lipid droplet formation, blood-brain barrier deterioration, neurodegeneration, and cognitive impairment. Delaying treatment until 8 months after TBI offers no protection. Thus, time-sensitive inhibition of acutely elevated mitochondrial fission may represent a strategy to protect human TBI patients from chronic neurodegeneration.

Mitigating Traumatic Brain Injury: A Narrative Review of Supplementation and Dietary Protocols

Traumatic brain injuries (TBIs) constitute a significant public health issue and a major source of disability and death in the United States and worldwide. TBIs are strongly associated with high morbidity and mortality rates, resulting in a host of negative health outcomes and long-term complications and placing a heavy financial burden on healthcare systems. One promising avenue for the prevention and treatment of brain injuries is the design of TBI-specific supplementation and dietary protocols centred around nutraceuticals and biochemical compounds whose mechanisms of action have been shown to interfere with, and potentially alleviate, some of the neurophysiological processes triggered by TBI. For example, evidence suggests that creatine monohydrate and omega-3 fatty acids (DHA and EPA) help decrease inflammation, reduce neural damage and maintain adequate energy supply to the brain following injury. Similarly, melatonin supplementation may improve some of the sleep disturbances often experienced post-TBI. The scope of this narrative review is to summarise the available literature on the neuroprotective effects of selected nutrients in the context of TBI-related outcomes and provide an evidence-based overview of supplementation and dietary protocols that may be considered in individuals affected by-or at high risk for-concussion and more severe head traumas. Prophylactic and/or therapeutic compounds under investigation include creatine monohydrate, omega-3 fatty acids, BCAAs, riboflavin, choline, magnesium, berry anthocyanins, Boswellia serrata, enzogenol, N-Acetylcysteine and melatonin. Results from this analysis are also placed in the context of assessing and addressing important health-related and physiological parameters in the peri-impact period such as premorbid nutrient and metabolic health status, blood glucose regulation and thermoregulation following injury, caffeine consumption and sleep behaviours. As clinical evidence in this research field is rapidly emerging, a comprehensive approach including appropriate nutritional interventions has the potential to mitigate some of the physical, neurological, and emotional damage inflicted by TBIs, promote timely and effective recovery, and inform policymakers in the development of prevention strategies.

Oxidative stress in the brain-lung crosstalk: cellular and molecular perspectives

Oxidative stress is caused by an imbalance between the production of reactive oxygen species (ROS) and the body's ability to counteract their harmful effects, playing a key role in the pathogenesis of brain and lung-related diseases. This review comprehensively examines the intricate mechanisms by which oxidative stress influences cellular and molecular pathways, contributing to neurodegenerative, cardiovascular, and respiratory disorders. Emphasizing the detrimental effects on both brain and lung health, we discuss innovative diagnostic biomarkers, such as 8-hydroxy-2'-deoxyguanosine (8-OHdG), and the potential of antioxidant therapies. For these topics, we provide insights into future research directions in the field of oxidative stress treatment, including the development of personalized treatment approaches, the discovery and validation of novel biomarkers, and the development of new drug delivery systems. This review not only provides a new perspective on understanding the role of oxidative stress in brain and lung-related diseases but also offers new insights for future clinical treatments.

A Potential Role Exists for Nutritional Interventions in the Chronic Phase of Mild Traumatic Brain Injury, Concussion and Sports-Related Concussion: A Systematic Review

Mild traumatic brain injury (mTBI) represents a significant burden for individuals, economies, and healthcare systems worldwide. Recovery protocols focus on medication and physiotherapy-based interventions. Animal studies have shown that antioxidants, branched-chain amino acids and omega-3 fatty acids may improve neurophysiological outcomes after TBI. However, there appears to be a paucity of nutritional interventions in humans with chronic (≥1 month) symptomology post-mTBI. This systematic literature review aimed to consolidate evidence for nutrition and dietary-related interventions in humans with chronic mTBI. The review was registered with the International Prospective Register of Systematic Reviews (PROSPERO; CRD42021277780) and conducted following the Preferred Reporting for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Three reviewers searched five databases (PubMed/MEDLINE, Web of Science, SPORTDiscus, CINAHL Complete and Cochrane), which yielded 6164 studies. Nine studies met the inclusion criteria. The main finding was the lack of interventions conducted to date, and a quality assessment of the included studies was found to be fair to good. Due to heterogeneity, a meta-analysis was not feasible. The six nutrition areas identified (omega-3 fatty acids, melatonin, Enzogenol®, MLC901, ketogenic diet and phytocannabinoids) were safe and well-tolerated. It was found that these nutritional interventions may improve cognitive failures, sleep disturbances, anxiety, physical disability, systolic blood pressure volume and sport concussion assessment tool scores following mTBI. Potential areas of improvement identified for future studies included blinding, reporting compliance, and controlling for confounders. In conclusion, further research of higher quality is needed to investigate the role of nutrition in recovery from mTBI to reduce the burden of chronic outcomes following mTBI.

The Protective Role and Mechanism of Mild Therapeutic Hypothermia Protection on Brain Cells

Background

Moderate therapeutic hypothermia is protective against several cellular stressors. However, the mechanisms behind this protection are not entirely known. In the current investigation, we investigated that therapeutic hypothermia at 33°C administered following peroxide-induced oxidative stress might protect human oligodendroglioma cells using an in vitro model.

Methods and Results

Tert-butyl peroxide treatment for one hour significantly increased cell apoptosis and suppressed cell viability. In the range of 50-1000 M tert-butyl peroxide, this cell death was dose-dependent. MTT assay and cell apoptosis assay were applied to analyze cell viability/death at 24 hours after peroxide-induced stress. Therapeutic hypothermia at 33°C delivered for two hours after peroxide exposure significantly increased cell viability and suppressed cell death. Even 15 minutes after peroxide washout when delayed hypothermia was used, this protection was still apparent. Three FDA-approved antioxidants (Tempol, EUK134, and Edaravone at 100 M) were added immediately after tert-butyl peroxide, followed by hypothermia treatment. These three antioxidants greatly increased cell viability and cell apoptosis. RT-qPCR was applied to determine the effects of hypothermia treatment on the expression of caspase-3 and -8 as well as tumor necrosis factor-alpha (TNF-α). Therapeutic hypothermia significantly downregulated these three factors.

Conclusion

Overall, these findings confirmed that hypothermia and antioxidants quenching reactive oxygen species may lower mitochondrial oxidative stress and/or apoptotic pathways. Further investigation are needed to investigate the role of hypothermia in other cell models.

Traumatic Brain Injury Triggers Neurodegeneration in a Mildly Symptomatic MELAS Patient: Implications on the Detrimental Role of Damaged Mitochondria in Determining Head Trauma Sequalae in the General Population

Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is a maternally inherited genetic mitochondrial disease with a typical onset in the first two decades of life and a major involvement of central nervous system (CNS). We present the case of a man affected with an oligosymptomatic, genetically determined MELAS syndrome, whose clinical picture dramatically and irreversibly worsened following a mild head injury. We hypothesize that the CNS metabolic stress induced by the brain injury activated an irreversible cascade of events leading to progressive neurodegeneration because damaged mitochondria were unable to restore the balance between energy requirements and availability.

Honokiol Reduces Mitochondrial Dysfunction and Inhibits Apoptosis of Nerve Cells in Rats with Traumatic Brain Injury by Activating the Mitochondrial Unfolded Protein Response

This study was designed to determine the effects and underlying mechanism of honokiol (HNK) on traumatic brain injury (TBI). A rat TBI model was constructed using the modified Feeney free-fall percussion method and treatment with HNK via intraperitoneal injection. The brain tissues of the rats in each group were assessed using the terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay to detect the level of neuronal apoptosis. Western blots were used to detect the expression levels of apoptosis-related proteins (Bcl-2 and Bax), and ELISAs were used to measure the levels of pro-inflammatory cytokines (IL-18 and IL-1β) and the activity of caspase-1. In addition, the mitochondrial membrane potential, reactive oxygen species (ROS), and adenosine 5'-triphosphate (ATP) were also measured. Western blots and qRT-PCRs were used to determine the relative expression levels of the mitochondrial unfolded protein response (UPRmt)-related proteins and mRNAs. Based on the experimental results, treatment with HNK was associated with a decrease in the number of TUNEL-positive cells, downregulated Bax expression levels, elevated Bcl-2 expression levels, and inhibition of neuronal apoptosis in the brain tissue of TBI rats. HNK also suppressed neuroinflammation by decreasing IL-1β and IL-18 levels and caspase-1 activity. Additionally, HNK lowered the mitochondrial membrane potential and ROS levels, increased ATP levels, and improved mitochondrial dysfunction in neural cells. Furthermore, in the investigation of the mechanism of HNK on TBI, we observed that HNK could activate UPRmt by upregulating the mRNA and protein expression levels of HSPA9, CLPP, and HSP60 in the brain tissues of TBI rats. Collectively, HNK reduced mitochondrial dysfunction, inhibited the apoptosis of nerve cells, and attenuated inflammation in the brains of TBI rats. The protective effect of HNK may be achieved through the activation of UPRmt.

Serum vitamin E level and functional prognosis after traumatic brain injury with intracranial injury: A multicenter prospective study

Background

Traumatic brain injury (TBI) is a major public health problem with high mortality and disability. Vitamin E, one of the antioxidants for treatment of TBI, has not been sufficiently evaluated for predicting prognosis of TBI. This study aimed to evaluate the prognostic value of vitamin E on functional outcomes of TBI patients with intracranial injury.

Methods

A multi-center prospective cohort study was conducted in five university hospitals between 2018 and 2020. Adult TBI patients who visited the emergency department (ED) with intracranial hemorrhage or diffuse axonal injury confirmed by radiological examination were eligible. Serum vitamin E levels (mg/dL) were categorized into 4 groups: low (0.0–5.4), low-normal (5.5–10.9), high-normal (11.0–16.9), and high (17.0–). Study outcomes were set as 1- and 6-month disability (Glasgow outcome scale (GOS) 1–4). Multilevel logistic regression analysis was conducted to calculate the adjusted odds ratios (AORs) of vitamin E for related outcomes.

Results

Among 550 eligible TBI patients with intracranial injury, the median (IQR) of serum vitamin E was 10.0 (8.0–12.3) mg/dL; 204/550 (37.1%) had 1-month disability and 197/544 (36.1%) had 6-month disability of GOS 1–4. Compared with the high-normal group, the odds of 1-month disability and 6-month disability increased in the low and low-normal group (AORs (95% CIs): 3.66 (1.62–8.27) and 2.60 (1.15–5.85) for the low group and 1.63 (1.08–2.48) and 1.60 (1.04–2.43) for the low-normal group, respectively).

Conclusion

Low serum vitamin E level was associated with poor prognosis at 1 and 6 months after TBI with intracranial injury.

Nutritional interventions to support acute mTBI recovery

When mild traumatic brain injury (mTBI) occurs following an impact on the head or body, the brain is disrupted leading to a series of metabolic events that may alter the brain's ability to function and repair itself. These changes may place increased nutritional demands on the body. Little is known on whether nutritional interventions are safe for patients to implement post mTBI and whether they may improve recovery outcomes. To address this knowledge gap, we conducted a systematic review to determine what nutritional interventions have been prescribed to humans diagnosed with mTBI during its acute period (<14 days) to support, facilitate, and result in measured recovery outcomes.

Methods

Databases CINAHL, PubMed, SPORTDiscus, Web of Science, and the Cochrane Library were searched from inception until January 6, 2021; 4,848 studies were identified. After removing duplicates and applying the inclusion and exclusion criteria, this systematic review included 11 full papers.

Results

Patients that consumed enough food to meet calorie and macronutrient (protein) needs specific to their injury severity and sex within 96 h post mTBI had a reduced length of stay in hospital. In addition, patients receiving nutrients and non-nutrient support within 24-96 h post mTBI had positive recovery outcomes. These interventions included omega-3 fatty acids (DHA and EPA), vitamin D, mineral magnesium oxide, amino acid derivative N-acetyl cysteine, hyperosmolar sodium lactate, and nootropic cerebrolysin demonstrated positive recovery outcomes, such as symptom resolution, improved cognitive function, and replenished nutrient deficiencies (vitamin D) for patients post mTBI.

Conclusion

Our findings suggest that nutrition plays a positive role during acute mTBI recovery. Following mTBI, patient needs are unique, and this review presents the potential for certain nutritional therapies to support the brain in recovery, specifically omega-3 fatty acids. However, due to the heterogenicity nature of the studies available at present, it is not possible to make definitive recommendations.

Systematic review registration

The systematic review conducted following the PRISMA guidelines protocol was registered (CRD42021226819), on Prospero.

Understanding Acquired Brain Injury: A Review

Any type of brain injury that transpires post-birth is referred to as Acquired Brain Injury (ABI). In general, ABI does not result from congenital disorders, degenerative diseases, or by brain trauma at birth. Although the human brain is protected from the external world by layers of tissues and bone, floating in nutrient-rich cerebrospinal fluid (CSF); it remains susceptible to harm and impairment. Brain damage resulting from ABI leads to changes in the normal neuronal tissue activity and/or structure in one or multiple areas of the brain, which can often affect normal brain functions. Impairment sustained from an ABI can last anywhere from days to a lifetime depending on the severity of the injury; however, many patients face trouble integrating themselves back into the community due to possible psychological and physiological outcomes. In this review, we discuss ABI pathologies, their types, and cellular mechanisms and summarize the therapeutic approaches for a better understanding of the subject and to create awareness among the public.

Oxidative stress and mitochondrial dysfunction following traumatic brain injury: From mechanistic view to targeted therapeutic opportunities

Traumatic brain injury (TBI) is one of the most prevalent causes of permanent physical and cognitive disabilities. TBI pathology results from primary insults and a multi-mechanistic biochemical process, termed as secondary brain injury. Currently, there are no pharmacological agents for definitive treatment of patients with TBI. This article is presented with the purpose of reviewing molecular mechanisms of TBI pathology, as well as potential strategies and agents against pathological pathways. In this review article, materials were obtained by searching PubMed, Scopus, Elsevier, Web of Science, and Google Scholar. This search was considered without time limitation. Evidence indicates that oxidative stress and mitochondrial dysfunction are two key mediators of the secondary injury cascade in TBI pathology. TBI-induced oxidative damage results in the structural and functional impairments of cellular and subcellular components, such as mitochondria. Impairments of mitochondrial electron transfer chain and mitochondrial membrane potential result in a vicious cycle of free radical formation and cell apoptosis. The results of some preclinical and clinical studies, evaluating mitochondria-targeted therapies, such as mitochondria-targeted antioxidants and compounds with pleiotropic effects after TBI, are promising. As a proposed strategy in recent years, mitochondria-targeted multipotential therapy is a new hope, waiting to be confirmed. Moreover, based on the available findings, biologics, such as stem cell-based therapy and transplantation of mitochondria are novel potential strategies for the treatment of TBI; however, more studies are needed to clearly confirm the safety and efficacy of these strategies.

Escalation of Tau Accumulation after a Traumatic Brain Injury: Findings from Positron Emission Tomography

Traumatic brain injury (TBI) has come to be recognized as a risk factor for Alzheimer's disease (AD), with poorly understood underlying mechanisms. We hypothesized that a history of TBI would be associated with greater tau deposition in elders with high-risk for dementia. A Groups of 20 participants with self-reported history of TBI and 100 without any such history were scanned using [18F]-AV1451 positron emission tomography as part of the Alzheimer's Disease Neuroimaging Initiative (ADNI). Scans were stratified into four groups according to TBI history, and by clinical dementia rating scores into cognitively normal (CDR = 0) and those showing cognitive decline (CDR ≥ 0.5). We pursued voxel-based group comparison of [18F]-AV1451 uptake to identify the effect of TBI history on brain tau deposition, and for voxel-wise correlation analyses between [18F]-AV1451 uptake and different neuropsychological measures and cerebrospinal fluid (CSF) biomarkers. Compared to the TBI-/CDR ≥ 0.5 group, the TBI+/CDR ≥ 0.5 group showed increased tau deposition in the temporal pole, hippocampus, fusiform gyrus, and inferior and middle temporal gyri. Furthermore, the extent of tau deposition in the brain of those with TBI history positively correlated with the extent of cognitive decline, CSF-tau, and CSF-amyloid. This might suggest TBI to increase the risk for tauopathies and Alzheimer's disease later in life.

Blood-Brain Barrier Mechanisms in Stroke and Trauma

The brain microenvironment is tightly regulated. The blood-brain barrier (BBB), which is composed of cerebral endothelial cells, astrocytes, and pericytes, plays an important role in maintaining the brain homeostasis by regulating the transport of both beneficial and detrimental substances between circulating blood and brain parenchyma. After brain injury and disease, BBB tightness becomes dysregulated, thus leading to inflammation and secondary brain damage. In this chapter, we overview the fundamental mechanisms of BBB damage and repair after stroke and traumatic brain injury (TBI). Understanding these mechanisms may lead to therapeutic opportunities for brain injury.

Natural Phytochemicals Derived from Gymnosperms in the Prevention and Treatment of Cancers

The incidence of various types of cancer is increasing globally. To reduce the critical side effects of cancer chemotherapy, naturally derived compounds have been considered for cancer treatment. Gymnosperms are a group of plants found worldwide that have traditionally been used for therapeutic applications. Paclitaxel is a commercially available anticancer drug derived from gymnosperms. Other natural compounds with anticancer activities, such as pinostrobin and pinocembrin, are extracted from pine heartwood, and pycnogenol and enzogenol from pine bark. Gymnosperms have great potential for further study for the discovery of new anticancer compounds. This review aims to provide a rational understanding and the latest developments in potential anticancer compounds derived from gymnosperms.

Ferroptosis and traumatic brain injury

Traumatic brain injury (TBI) is a worldwide health problem contributing to significant economic burden. TBI is difficult to treat partly due to incomplete understanding of pathophysiology. Ferroptosis is a type of iron-dependent programmed cell death which has gained increasing attention due to its possible role in TBI. Current studies have demonstrated that ferroptosis is related to the pathology of TBI, and inhibition of ferroptosis may improve long term outcomes of TBI. Therefore, clarification of the exact association between ferroptosis and traumatic brain injury is necessary and may provide new targets for treatment. This review describes (1) the ferroptosis pathways following traumatic brain injury, (2) the role of ferroptosis during the chronic phase of traumatic brain injury, and (3) potential therapies targeting the ferroptosis pathways.

An Overview and Therapeutic Promise of Nutraceuticals against Sports-Related Brain Injury

Sports-related traumatic brain injury (TBI) is one of the common neurological maladies experienced by athletes. Earlier the term 'punch drunk syndrome' was used in the case TBI of boxers and now this term is replaced by chronic traumatic encephalopathy (CTE). Sports-related brain injury can either be short term or long term. A common instance of brain injury encompasses subdural hematoma, concussion, cognitive dysfunction, amnesia, headache, vision issue, axonopathy, or even death if remain undiagnosed or untreated. Further, chronic TBI may lead to pathogenesis of neuroinflammation and neurodegeneration via tauopathy, formation of neurofibrillary tangles, and damage to the blood-brain barrier, microglial, and astrocyte activation. Thus, altered pathological, neurochemical, and neurometabolic attributes lead to the modulation of multiple signaling pathways and cause neurological dysfunction. Available pharmaceutical interventions are based on one drug one target hypothesis and thereby unable to cover altered multiple signaling pathways. However, in recent time's pharmacological intervention of nutrients and nutraceuticals have been explored as they exert a multifactorial mode of action and maintain over homeostasis of the body. There are various reports available showing the positive therapeutic effect of nutraceuticals in sport-related brain injury. Therefore, in the current article we have discussed the pathology, neurological consequence, sequelae, and perpetuation of sports-related brain injury. Further, we have discussed various nutraceutical supplements as well as available animal models to explore the neuroprotective effect/ upshots of these nutraceuticals in sports-related brain injury.

Mitochondria-Targeted Antioxidants: A Step towards Disease Treatment

Mitochondria are the main organelles that produce adenosine 5′-triphosphate (ATP) and reactive oxygen species (ROS) in eukaryotic cells and meanwhile susceptible to oxidative damage. The irreversible oxidative damage in mitochondria has been implicated in various human diseases. Increasing evidence indicates the therapeutic potential of mitochondria-targeted antioxidants (MTAs) for oxidative damage-associated diseases. In this article, we introduce the advantageous properties of MTAs compared with the conventional (nontargeted) ones, review different mitochondria-targeted delivery systems and antioxidants, and summarize their experimental results for various disease treatments in different animal models and clinical trials. The combined evidence demonstrates that mitochondrial redox homeostasis is a potential target for disease treatment. Meanwhile, the limitations and prospects for exploiting MTAs are discussed, which might pave ways for further trial design and drug development.

The role of the brain renin-angiotensin system (RAS) in mild traumatic brain injury (TBI)

There is considerable interest in traumatic brain injury (TBI) induced by repeated concussions suffered by athletes in sports, military personnel from combat-and non-combat related activities, and civilian populations who suffer head injuries from accidents and domestic violence. Although the renin-angiotensin system (RAS) is primarily a systemic cardiovascular regulatory system that, when dysregulated, causes hypertension and cardiovascular pathology, the brain contains a local RAS that plays a critical role in the pathophysiology of several neurodegenerative diseases. This local RAS includes receptors for angiotensin (Ang) II within the brain parenchyma, as well as on circumventricular organs outside the blood-brain-barrier. The brain RAS acts primarily via the type 1 Ang II receptor (AT₁R), exacerbating insults and pathology. With TBI, the brain RAS may contribute to permanent brain damage, especially when a second TBI occurs before the brain recovers from an initial injury. Agents are needed that minimize the extent of injury from an acute TBI, reducing TBI-mediated permanent brain damage. This review discusses how activation of the brain RAS following TBI contributes to this damage, and how drugs that counteract activation of the AT₁R including AT₁R blockers (ARBs), renin inhibitors, angiotensin-converting enzyme (ACE) inhibitors, and agonists at type 2 Ang II receptors (AT₂) and at Ang (1-7) receptors (Mas) can potentially ameliorate TBI-induced brain damage.

Mitochondrial DNA and Neurodegeneration: Any Role for Dietary Antioxidants?

The maintenance of the mitochondrial function is essential in preventing and counteracting neurodegeneration. In particular, mitochondria of neuronal cells play a pivotal role in sustaining the high energetic metabolism of these cells and are especially prone to oxidative damage. Since overproduction of reactive oxygen species (ROS) is involved in the pathogenesis of neurodegeneration, dietary antioxidants have been suggested to counteract the detrimental effects of ROS and to preserve the mitochondrial function, thus slowing the progression and limiting the extent of neuronal cell loss in neurodegenerative disorders. In addition to their role in the redox-system homeostasis, mitochondria are unique organelles in that they contain their own genome (mtDNA), which acts at the interface between environmental exposures and the molecular triggers of neurodegeneration. Indeed, it has been demonstrated that mtDNA (including both genetics and, from recent evidence, epigenetics) might play relevant roles in modulating the risk for neurodegenerative disorders. This mini-review describes the link between the mitochondrial genome and cellular oxidative status, with a particular focus on neurodegeneration; moreover, it provides an overview on potential beneficial effects of antioxidants in preserving mitochondrial functions through the protection of mtDNA.

Targeted disruption of dual leucine zipper kinase and leucine zipper kinase promotes neuronal survival in a model of diffuse traumatic brain injury

BACKGROUND

Traumatic brain injury (TBI) is a major cause of CNS neurodegeneration and has no disease-altering therapies. It is commonly associated with a specific type of biomechanical disruption of the axon called traumatic axonal injury (TAI), which often leads to axonal and sometimes perikaryal degeneration of CNS neurons. We have previously used genome-scale, arrayed RNA interference-based screens in primary mouse retinal ganglion cells (RGCs) to identify a pair of related kinases, dual leucine zipper kinase (DLK) and leucine zipper kinase (LZK) that are key mediators of cell death in response to simple axotomy. Moreover, we showed that DLK and LZK are the major upstream triggers for JUN N-terminal kinase (JNK) signaling following total axonal transection. However, the degree to which DLK/LZK are involved in TAI/TBI is unknown.

METHODS

Here we used the impact acceleration (IA) model of diffuse TBI, which produces TAI in the visual system, and complementary genetic and pharmacologic approaches to disrupt DLK and LZK, and explored whether DLK and LZK play a role in RGC perikaryal and axonal degeneration in response to TAI.

RESULTS

Our findings show that the IA model activates DLK/JNK/JUN signaling but, in contrast to axotomy, many RGCs are able to recover from the injury and terminate the activation of the pathway. Moreover, while DLK disruption is sufficient to suppress JUN phosphorylation, combined DLK and LZK inhibition is required to prevent RGC cell death. Finally, we show that the FDA-approved protein kinase inhibitor, sunitinib, which has activity against DLK and LZK, is able to produce similar increases in RGC survival.

CONCLUSION

The mitogen-activated kinase kinase kinases (MAP3Ks), DLK and LZK, participate in cell death signaling of CNS neurons in response to TBI. Moreover, sustained pharmacologic inhibition of DLK is neuroprotective, an effect creating an opportunity to potentially translate these findings to patients with TBI.

Hydrogen sulfide protects against cell damage through modulation of PI3K/Akt/Nrf2 signaling

Hydrogen sulfide as the third endogenous gaseous mediator had protective effects against traumatic brain injury-induced neuronal damage in mice. However, the exact pathophysiological mechanism underlying traumatic brain injury is complicated and the protective role of H₂S is not yet fully known. Therefore, we combined the mechanical injury (scratch) with secondary injury including metabolic impairment (no glucose) together to investigate the underlying cellular mechanism of hydrogen sulfide in vitro models of traumatic brain injury. In the present study, we found that H₂S could prevent the scratch-induced decrease in the expression of cystathionine-β-synthetase, a key enzyme involved in the source of hydrogen sulfide, and endogenous hydrogen sulfide generation in PC12 cells. We also found that hydrogen sulfide could prevent scratch-induced cellular injury, alteration of mitochondrial membrane potential, intracellular accumulation of reactive oxygen species and cell death (autophagic cell death and apoptosis) in PC12 cells. It was also found that blocking PI3K/AKT pathway by LY294002, abolished the protection of H₂S against scratch-induced cellular reactive oxygen species level and NRF2 accumulation and function in the nucleus. These results suggest that hydrogen sulfide protects against cell damage induced by scratch injury through modulation of the PI3K/Akt/Nrf2 pathway. This study raises the possibility that hydrogen sulfide may have therapeutic efficacy in traumatic brain injury.

Mitochondria-Targeted Antioxidants as Potential Therapy for the Treatment of Traumatic Brain Injury

The aim of this article is to review the publications describing the use of mitochondria-targeted antioxidant therapy after traumatic brain injury (TBI). Recent works demonstrated that mitochondria-targeted antioxidants are very effective in reducing the negative effects associated with the development of secondary damage caused by TBI. Using various animal models of TBI, mitochondria-targeted antioxidants were shown to prevent cardiolipin oxidation in the brain and neuronal death, as well as to markedly reduce behavioral deficits and cortical lesion volume, brain water content, and DNA damage. In the future, not only a more detailed study of the mechanisms of action of various types of such antioxidants needs to be conducted, but also their therapeutic values and toxicological properties are to be determined. Moreover, the optimal therapeutic effect needs to be achieved in the shortest time possible from the onset of damage to the nervous tissue, since secondary brain damage in humans can develop for a long time, days and even months, depending on the severity of the damage.

The preparation of oxidized methylcellulose crosslinked by adipic acid dihydrazide loaded with vitamin C for traumatic brain injury

Oxi-MC-ADH-VC can open up a new avenue for clinical TBI treatment and rehabilitation.

Diffusion Magnetic Resonance Imaging Unveils the Spatiotemporal Microstructural Gray Matter Changes following Injury in the Rodent Brain

Traumatic brain injury (TBI) is associated with gray and white matter alterations in brain tissue. Gray matter alterations are not yet as well studied as those of the white matter counterpart. This work utilized T2-weighted structural imaging, diffusion tensor imaging (DTI), and diffusion kurtosis imaging to unveil the gray matter changes induced in a controlled cortical impact (CCI) mouse model of TBI at 5 h, 1 day, 3 days, 7 days, 14 days, and 30 days post-CCI. A cross-sectional histopathology approach was used to confer validity of the magnetic resonance imaging (MRI) data by performing cresyl violet staining and glial fibrillary acidic protein (GFAP) immunohistochemistry. The results demonstrated a significant increase in lesion volume up to 3 days post-injury followed by a significant decrease in the cavity volume for the period of 1 month. GFAP signals peaked on Day 7 and persisted until Day 30 in both ipsilateral and contralateral hippocampus, ipsilateral cortex, and thalamic areas. An increase in fractional anisotropy (FA) was seen at Day 7 in the pericontusional area but decreased FA in the contralateral cortex, hippocampus, and thalamus. Mean diffusivity (MD) was significantly lower in the pericontusional cortex. Increased MD and decreased mean kurtosis were limited to the injury site on Days 7 to 30 and to the contralateral hippocampus and thalamus on Days 3 and 7. This work is one of the few cross-sectional studies to demonstrate a link between MRI measures and histopathological readings to track gray matter changes in the progression of TBI.

Neuroprotective Agents in the Intensive Care Unit: -Neuroprotective Agents in ICU

Neuroprotection or prevention of neuronal loss is a complicated molecular process that is mediated by various cellular pathways. Use of different pharmacological agents as neuroprotectants has been reported especially in the last decades. These neuroprotective agents act through inhibition of inflammatory processes and apoptosis, attenuation of oxidative stress and reduction of free radicals. Control of this injurious molecular process is essential to the reduction of neuronal injuries and is associated with improved functional outcomes and recovery of the patients admitted to the intensive care unit. This study reviews neuroprotective agents and their mechanisms of action against central nervous system damages.

Relationships between enteral nutrition facts and urinary stones in a cohort of pediatric patients in rehabilitation from severe acquired brain injury

BACKGROUND & AIMS

Urolithiasis affects pediatric patients with severe acquired brain injury, in whom the role of several clinical variables and of the presence and composition of enteral nutrition has not been investigated.

METHODS

Retrospective chart review on 371 pediatric patients with severe acquired brain injury. We used an essential electronic database to check the association between stones and enteral feeding. We then picked at random paper clinical records until we collected 20 and 20 complete records for patients with/without stones, not matched. With that information, we tested the association of stones with: nutrition facts of enteral formulae (sodium, potassium, calcium, magnesium, phosphorus, proteins, vitamin C); bladder dysfunction, urinary infections, catheterisms, tracheostomy, gallstones, way of feeding; blood and urine exams before stones diagnosis; age, type and severity of injury; prior physical activity, relevant drugs.

RESULTS

All patients with stones were fed enterally. At univariate statistics they were older, weighed more, received bigger volumes of hydration and nutrition; they had worse GCS, more UTIs and they alone received catheterisms; their nutrition mixes were richer in sodium. In multivariate logistic regression for stone development, UTIs (OR 11.4, 95% C.I. 1.6-83.4) and higher sodium nutrition content (OR 7.5, 95% C.I. 1.6-34.3) were risk factors; higher GCS (OR 0.66, 95% C.I. 0.43-0.99) and higher calcium nutrition content (OR 0.14, 95% C.I. 0.03-0.73) were protective factors.

CONCLUSIONS

Besides known risk factors for urolithiasis, including UTIs, catheterisms, worse neurological states, also enteral nutrition was a risk factor, particularly with higher sodium and lower calcium contents. Future studies should test the effect of different sodium/calcium nutrition contents on lithogenesis.

MLC901 (NeuroAiD II™) for cognition after traumatic brain injury: a pilot randomized clinical trial

Background and purpose

Treatments to facilitate recovery after traumatic brain injury (TBI) are urgently needed. We conducted a 9‐month pilot, randomized placebo‐controlled clinical trial to examine the safety and potential effects of the herbal supplement MLC901 (NeuroAiD II™) on cognitive functioning following TBI.

Methods

Adults aged 18–65 years at 1–12 months after mild or moderate TBI were randomized to receive MLC901 (0.8 g capsules 3 times daily) or placebo for 6 months. The primary outcome was cognitive functioning as assessed by the CNS Vital Signs online neuropsychological test. Secondary outcomes included the Cognitive Failures Questionnaire, the Rivermead Post‐concussion Symptom Questionnaire (neurobehavioral sequelae), Quality of Life after Brain Injury, Hospital Anxiety and Depression Scale, Modified Fatigue Impact Scale and extended Glasgow Outcome Scale (physical disability). Assessments were completed at baseline and at 3‐, 6‐ and 9‐month follow‐up. Linear mixed‐effects models were conducted, with the primary outcome time‐point of 6 months.

Results

A total of 78 participants [mean age 37.5 ± 14.8 years, 39 (50%) female] were included in the analysis. Baseline variables were similar between groups (treatment group, n = 36; control group, n = 42). Linear mixed‐effects models controlling for time, group allocation, repeated measurements, adherence and baseline assessment scores revealed significant improvements in complex attention (P = 0.04, d = 0.6) and executive functioning (P = 0.04, d = 0.4) at 6 months in the MLC901 group compared with controls. There were no significant differences between the groups for neurobehavioral sequelae, mood, fatigue, physical disability or overall quality of life at 6 months. No serious adverse events were reported.

Conclusions

MLC901 was safe and well tolerated post‐TBI. This study provided Class I/II evidence that, for patients with mild to moderate TBI, 6 months of MLC901 improved cognitive functioning.

Systematic Review of Human and Animal Studies Examining the Efficacy and Safety of N-Acetylcysteine (NAC) and N-Acetylcysteine Amide (NACA) in Traumatic Brain Injury: Impact on Neurofunctional Outcome and Biomarkers of Oxidative Stress and Inflammation

Background

No new therapies for traumatic brain injury (TBI) have been officially translated into current practice. At the tissue and cellular level, both inflammatory and oxidative processes may be exacerbated post-injury and contribute to further brain damage. N-acetylcysteine (NAC) has the potential to downregulate both processes. This review focuses on the potential neuroprotective utility of NAC and N-acetylcysteine amide (NACA) post-TBI.

Methods

Medline, Embase, Cochrane Library, and ClinicalTrials.gov were searched up to July 2017. Studies that examined clinical and laboratory effects of NAC and NACA post-TBI in human and animal studies were included. Risk of bias was assessed in human and animal studies according to the design of each study (randomized or not). The primary outcome assessed was the effect of NAC/NACA treatment on functional outcome, while secondary outcomes included the impact on biomarkers of inflammation and oxidation. Due to the clinical and methodological heterogeneity observed across studies, no meta-analyses were conducted.

Results

Our analyses revealed only three human trials, including two randomized controlled trials (RCTs) and 20 animal studies conducted using standardized animal models of brain injury. The two RCTs reported improvement in the functional outcome post-NAC/NACA administration. Overall, the evidence from animal studies is more robust and demonstrated substantial improvement of cognition and psychomotor performance following NAC/NACA use. Animal studies also reported significantly more cortical sparing, reduced apoptosis, and lower levels of biomarkers of inflammation and oxidative stress. No safety concerns were reported in any of the studies included in this analysis.

Conclusion

Evidence from the animal literature demonstrates a robust association for the prophylactic application of NAC and NACA post-TBI with improved neurofunctional outcomes and downregulation of inflammatory and oxidative stress markers at the tissue level. While a growing body of scientific literature suggests putative beneficial effects of NAC/NACA treatment for TBI, the lack of well-designed and controlled clinical investigations, evaluating therapeutic outcomes, prognostic biomarkers, and safety profiles, limits definitive interpretation and recommendations for its application in humans at this time.

Pathophysiological Bases of Comorbidity: Traumatic Brain Injury and Post-Traumatic Stress Disorder

The high rates of traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD) diagnoses encountered in recent years by the United States Veterans Affairs Healthcare System have increased public awareness and research investigation into these conditions. In this review, we analyze the neural mechanisms underlying the TBI/PTSD comorbidity. TBI and PTSD present with common neuropsychiatric symptoms including anxiety, irritability, insomnia, personality changes, and memory problems, and this overlap complicates diagnostic differentiation. Interestingly, both TBI and PTSD can be produced by overlapping pathophysiological changes that disrupt neural connections termed the "connectome." The neural disruptions shared by PTSD and TBI and the comorbid condition include asymmetrical white matter tract abnormalities and gray matter changes in the basolateral amygdala, hippocampus, and prefrontal cortex. These neural circuitry dysfunctions result in behavioral changes that include executive function and memory impairments, fear retention, fear extinction deficiencies, and other disturbances. Pathophysiological etiologies can be identified using experimental models of TBI, such as fluid percussion or blast injuries, and for PTSD, using models of fear conditioning, retention, and extinction. In both TBI and PTSD, there are discernible signs of neuroinflammation, excitotoxicity, and oxidative damage. These disturbances produce neuronal death and degeneration, axonal injury, and dendritic spine dysregulation and changes in neuronal morphology. In laboratory studies, various forms of pharmacological or psychological treatments are capable of reversing these detrimental processes and promoting axonal repair, dendritic remodeling, and neurocircuitry reorganization, resulting in behavioral and cognitive functional enhancements. Based on these mechanisms, novel neurorestorative therapeutics using anti-inflammatory, antioxidant, and anticonvulsant agents may promote better outcomes for comorbid TBI and PTSD.

The NADPH oxidase NOX2 mediates loss of parvalbumin interneurons in traumatic brain injury: human autoptic immunohistochemical evidence

Pharmacological interventions for traumatic brain injury (TBI) are limited. Together with parvalbumin (PV) loss, increased production of reactive oxygen species (ROS) by the NADPH oxidase NOX enzymes represents a key step in TBI. Here, we investigated the contribution of NOX2-derived oxidative stress to the loss of PV immunoreactivity associated to TBI, performing immunohistochemistry for NOX2, 8-hydroxy-2′-deoxyguanosine (8OHdG) and PV on post mortem brain samples of subjects died following TBI, subjects died from spontaneous intracerebral hemorrhage (SICH) and controls (CTRL). We detected an increased NOX2 expression and 8OHdG immunoreactivity in subjects died from TBI with respect to CTRL and SICH. NOX2 increase was mainly observed in GABAergic PV-positive interneurons, with a minor presence in microglia. No significant differences in other NADPH oxidase isoforms (NOX1 and NOX4) were detected among experimental groups. NOX2-derived oxidative stress elevation appeared a specific TBI-induced phenomenon, as no alterations in the nitrosative pathway were detected. Our results suggest that NOX2-derived oxidative stress might play a crucial role in the TBI-induced loss of PV-positive interneurons.

Acute administration of catalase targeted to ICAM-1 attenuates neuropathology in experimental traumatic brain injury

Traumatic brain injury (TBI) contributes to one third of injury related deaths in the US. Treatment strategies for TBI are supportive, and the pathophysiology is not fully understood. Secondary mechanisms of injury in TBI, such as oxidative stress and inflammation, are points at which intervention may reduce neuropathology. Evidence suggests that reactive oxygen species (ROS) propagate blood-brain barrier (BBB) hyperpermeability and inflammation following TBI. We hypothesized that targeted detoxification of ROS may improve the pathological outcomes of TBI. Following TBI, endothelial activation results in a time dependent increase in vascular expression of ICAM-1. We conjugated catalase to anti-ICAM-1 antibodies and administered the conjugate to 8 wk old C57BL/6J mice 30 min after moderate controlled cortical impact injury. Results indicate that catalase targeted to ICAM-1 reduces markers of oxidative stress, preserves BBB permeability, and attenuates neuropathological indices more effectively than non-targeted catalase and anti-ICAM-1 antibody alone. Furthermore, the study of microglia by two-photon microscopy revealed that anti-ICAM-1/catalase prevents the transition of microglia to an activated phenotype. These findings demonstrate the use of a targeted antioxidant enzyme to interfere with oxidative stress mechanisms in TBI and provide a proof-of-concept approach to improve acute TBI management that may also be applicable to other neuroinflammatory conditions.

Protective Effect of N-Acetylcysteine Amide on Blast-Induced Increase in Intracranial Pressure in Rats

Blast-induced traumatic brain injury is associated with acute and possibly chronic elevation of intracranial pressure (ICP). The outcome after TBI is dependent on the progression of complex processes which are mediated by oxidative stress. So far, no effective pharmacological protection against TBI exists. In this study, rats were exposed to a single or repetitive blast overpressure (BOP) at moderate intensities of 72 or 110 kPa in a compressed air-driven shock tube. The degree and duration of the increase in ICP were proportional to the intensity and frequency of the blast exposure(s). In most cases, a single dose of antioxidant N-acetylcysteine amide (NACA) (500 mg/kg) administered intravenously 2 h after exposure to BOP significantly attenuated blast-induced increase in ICP. A single dose of NACA was not effective in improving the outcome in the group of animals that were subjected to repetitive blast exposures at 110 kPa on the same day. In this group, two treatments with NACA at 2 and 4 h post-BOP exposure resulted in significant attenuation of elevated ICP. Treatment with NACA prior to BOP exposure completely prevented the elevation of ICP. The findings indicate that oxidative stress plays an important role in blast-induced elevated ICP as treatment with NACA-ameliorated ICP increase, which is frequently related to poor functional recovery after TBI.

The use of antioxidants in the treatment of traumatic brain injury

AIMS

The aim of this study was to discuss secondary traumatic brain injury, the mitochondria and the use of antioxidants as a treatment.

BACKGROUND

One of the leading causes of death globally is traumatic brain injury, affecting individuals in all demographics. Traumatic brain injury is produced by an external blunt force or penetration resulting in alterations in brain function or pathology. Often, with a traumatic brain injury, secondary injury causes additional damage to the brain tissue that can have further impact on recovery and the quality of life. Secondary injury occurs when metabolic and physiologic processes alter after initial injury and includes increased release of toxic free radicals that cause damage to adjacent tissues and can eventually lead to neuronal necrosis. Although antioxidants in the tissues can reduce free radical damage, the magnitude of increased free radicals overwhelms the body's reduced defence mechanisms. Supplementing the body's natural supply of antioxidants, such as coenzyme Q10, can attenuate oxidative damage caused by reactive oxygen species.

DESIGN

Discussion paper.

DATA SOURCES

Research literature published from 2011-2016 in PubMed, CINAHL and Cochrane.

IMPLICATIONS FOR NURSING

Prompt and accurate assessment of patients with traumatic brain injury by nurses is important to ensure optimal recovery and reduced lasting disability. Thus, it is imperative that nurses be knowledgeable about the secondary injury that occurs after a traumatic brain injury and aware of possible antioxidant treatments.

CONCLUSION

The use of antioxidants has potential to reduce the magnitude of secondary injury in patients who experience a traumatic brain injury.

Early Administration of Selenium in Patients with Acute Traumatic Brain Injury: A Randomized Double-blinded Controlled Trial

Aim:

The present study was carried out to examine this hypothesis that administration of selenium can prevent the development of injuries by brain trauma and thus can modulate patients’ functional recovery and also improve posttraumatic outcome.

Materials and Methods:

This double-blinded controlled trial was carried out on 113 patients who were hospitalized following traumatic brain injury (TBI) with Glasgow Coma Scale score of 4–12 that were randomly assigned to receive selenium within 8 h after injury plus standard treatment group or routine standard treatment alone as the control. The primary endpoint was to assess patients’ functional recovery at 2 months after the injury based on extended Glasgow Outcome Scale score (GOS-E). Secondary outcomes included the changes in Full Outline of Unresponsiveness score (FOUR) score, Sequential Organ Failure Assessment (SOFA) score, and acute physiology and chronic health evaluation (APACHE) III score, side effects of selenium, length of Intensive Care Unit (ICU) stay, and length of hospital stay.

Results:

There was no difference in the length of ICU and hospital stay, the trend of the change in FOUR and SOFA scores within 15 days of first interventions, and the mean APACHE III score on the 1^st and 15^th days between the two groups. Mortality was 15.8% in selenium group and 19.6% in control group with no between-group difference. No difference was revealed between the two groups in appropriate outcome according to GOS-E score at 60 ± 10 days and also 30 ± 5 days according to the severity of TBI.

Conclusion:

This human trial study could not demonstrate beneficial effects of intravenous infusion of selenium in the improvement of outcomes in patients with acute TBI.

Rhein and rhubarb similarly protect the blood-brain barrier after experimental traumatic brain injury via gp91phox subunit of NADPH oxidase/ROS/ERK/MMP-9 signaling pathway

Oxidative stress chiefly contributes to the disruption of the BBB following traumatic brain injury (TBI). The Chinese herbal medicine rhubarb is a promising antioxidant in treating TBI. Here we performed in vivo and in vitro experiments to determine whether rhubarb and its absorbed bioactive compound protected the BBB after TBI by increasing ZO-1 expression through inhibition of gp91phox subunit of NADPH oxidase/ROS/ERK/MMP-9 pathway. Rats were subjected to the controlled cortical impact (CCI) model, and primary rat cortical astrocytes were exposed to scratch-wound model. The liquid chromatography with tandem mass spectrometry method showed that rhein was the compound absorbed in the brains of CCI rats after rhubarb administration. The wet-dry weights and Evans blue measurements revealed that rhubarb and rhein ameliorated BBB damage and brain edema in CCI rats. Western blots showed that rhubarb and rhein downregulated GFAP in vitro. RT-PCR, immunohistochemistry, Western blot and dichlorodihydrofluorescein diacetate analysis indicated that rhubarb prevented activation of gp91phox subunit of NADPH oxidase induced ROS production, subsequently inhibited ERK/MMP-9 pathway in vivo and in vitro. Interestingly, rhein and rhubarb similarly protected the BBB by inhibiting this signaling cascade. The results provide a novel herbal medicine to protect BBB following TBI via an antioxidative molecular mechanism.

Oxidation of KCNB1 Potassium Channels Causes Neurotoxicity and Cognitive Impairment in a Mouse Model of Traumatic Brain Injury

The delayed rectifier potassium (K+) channel KCNB1 (Kv2.1), which conducts a major somatodendritic current in cortex and hippocampus, is known to undergo oxidation in the brain, but whether this can cause neurodegeneration and cognitive impairment is not known. Here, we used transgenic mice harboring human KCNB1 wild-type (Tg-WT) or a nonoxidable C73A mutant (Tg-C73A) in cortex and hippocampus to determine whether oxidized KCNB1 channels affect brain function. Animals were subjected to moderate traumatic brain injury (TBI), a condition characterized by extensive oxidative stress. Dasatinib, a Food and Drug Administration-approved inhibitor of Src tyrosine kinases, was used to impinge on the proapoptotic signaling pathway activated by oxidized KCNB1 channels. Thus, typical lesions of brain injury, namely, inflammation (astrocytosis), neurodegeneration, and cell death, were markedly reduced in Tg-C73A and dasatinib-treated non-Tg animals. Accordingly, Tg-C73A mice and non-Tg mice treated with dasatinib exhibited improved behavioral outcomes in motor (rotarod) and cognitive (Morris water maze) assays compared to controls. Moreover, the activity of Src kinases, along with oxidative stress, were significantly diminished in Tg-C73A brains. Together, these data demonstrate that oxidation of KCNB1 channels is a contributing mechanism to cellular and behavioral deficits in vertebrates and suggest a new therapeutic approach to TBI.

SIGNIFICANCE STATEMENT

This study provides the first experimental evidence that oxidation of a K+ channel constitutes a mechanism of neuronal and cognitive impairment in vertebrates. Specifically, the interaction of KCNB1 channels with reactive oxygen species plays a major role in the etiology of mouse model of traumatic brain injury (TBI), a condition associated with extensive oxidative stress. In addition, a Food and Drug Administration-approved drug ameliorates the outcome of TBI in mouse, by directly impinging on the toxic pathway activated in response to oxidation of the KCNB1 channel. These findings elucidate a basic mechanism of neurotoxicity in vertebrates and might lead to a new therapeutic approach to TBI in humans, which, despite significant efforts, is a condition that remains without effective pharmacological treatments.