BDNF and IL-8, But Not UCHL-1 and IL-11, Are Markers of Brain Injury in Children Caused by Mild Head Trauma

Ghrelin ameliorates neuronal damage, oxidative stress, inflammatory parameters, and GFAP expression in traumatic brain injury

OBJECTIVE

This study investigated the effects of ghrelin on oxidative stress, working memory, inflammatory parameters, and neuron degeneration.

METHODS

TBI was produced with the weight-drop technique. Rats in the G+TBI and TBI+G groups received ghrelin for 7 or 2 days, respectively. The control group received saline. On the 8th day of the study, the brain and blood tissue were taken under anesthesia.

RESULTS

A significant increase in brain GSH-PX, MDA, IL-1β, TGF-β1, and IL-8 levels and a significant decrease in CAT levels were found in the TBI group compared to the control. Serum MDA, GSH, IL-1β, and IL-8 levels were increased with TBI. Ghrelin treatment after TBI significantly increased the serum GSH, CAT, GSH-PX, and brain GSH and CAT levels, while it significantly decreased the serum MDA, IL-1β, and brain MDA, TGF-β1, and IL-8 levels. Histological evaluations revealed that ghrelin treatment led to a reduction in inflammation, while also significantly ameliorating TBI-induced neuron damage and vascular injuries. Immunohistochemistry staining showed that GFAP staining intensity was significantly increased in the cortex and hippocampus in TBI, and GFAP immunoreactivity was decreased with ghrelin treatment.

CONCLUSION

The results from this study suggested that ghrelin may have curative effects on TBI.

The contribution of the meningeal immune interface to neuroinflammation in traumatic brain injury

Traumatic brain injury (TBI) is a major cause of disability and mortality worldwide, particularly among the elderly, yet our mechanistic understanding of what renders the post-traumatic brain vulnerable to poor outcomes, and susceptible to neurological disease, is incomplete. It is well established that dysregulated and sustained immune responses elicit negative consequences after TBI; however, our understanding of the neuroimmune interface that facilitates crosstalk between central and peripheral immune reservoirs is in its infancy. The meninges serve as the interface between the brain and the immune system, facilitating important bi-directional roles in both healthy and disease settings. It has been previously shown that disruption of this system exacerbates neuroinflammation in age-related neurodegenerative disorders such as Alzheimer's disease; however, we have an incomplete understanding of how the meningeal compartment influences immune responses after TBI. In this manuscript, we will offer a detailed overview of the holistic nature of neuroinflammatory responses in TBI, including hallmark features observed across clinical and animal models. We will highlight the structure and function of the meningeal lymphatic system, including its role in immuno-surveillance and immune responses within the meninges and the brain. We will provide a comprehensive update on our current knowledge of meningeal-derived responses across the spectrum of TBI, and identify new avenues for neuroimmune modulation within the neurotrauma field.

Exploratory factor analysis yields grouping of brain injury biomarkers significantly associated with outcomes in neonatal and pediatric ECMO

In this two-center prospective cohort study of children on ECMO, we assessed a panel of plasma brain injury biomarkers using exploratory factor analysis (EFA) to evaluate their interplay and association with outcomes. Biomarker concentrations were measured daily for the first 3 days of ECMO support in 95 participants. Unfavorable composite outcome was defined as in-hospital mortality or discharge Pediatric Cerebral Performance Category > 2 with decline ≥ 1 point from baseline. EFA grouped 11 biomarkers into three factors. Factor 1 comprised markers of cellular brain injury (NSE, BDNF, GFAP, S100β, MCP1, VILIP-1, neurogranin); Factor 2 comprised markers related to vascular processes (vWF, PDGFRβ, NPTX1); and Factor 3 comprised the BDNF/MMP-9 cellular pathway. Multivariable logistic models demonstrated that higher Factor 1 and 2 scores were associated with higher odds of unfavorable outcome (adjusted OR 2.88 [1.61, 5.66] and 1.89 [1.12, 3.43], respectively). Conversely, higher Factor 3 scores were associated with lower odds of unfavorable outcome (adjusted OR 0.54 [0.31, 0.88]), which is biologically plausible given the role of BDNF in neuroplasticity. Application of EFA on plasma brain injury biomarkers in children on ECMO yielded grouping of biomarkers into three factors that were significantly associated with unfavorable outcome, suggesting future potential as prognostic instruments.

Acute Fluid Biomarkers for Diagnosis and Prognosis in Children with Mild Traumatic Brain Injury: A Systematic Review

BACKGROUND AND OBJECTIVE

Fluid biomarkers have the potential to improve the accuracy of diagnosis and prognosis in children with mild traumatic brain injury. Our primary objective was to assess the diagnostic and prognostic utility of acute blood and fluid biomarkers in children with mild traumatic brain injury.

METHODS

We performed a systematic review of the published literature in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology. Fluid biomarker studies assessing pediatric mild traumatic brain injury diagnosis or prognosis were included if blood or fluids were sampled within 24 h of injury.

RESULTS

Thirty-two studies involving 4743 patients were included comprising 25 diagnostic studies and ten prognostic studies with three studies assessing both diagnosis and prognosis. Sixteen of the 25 diagnostic studies reported the area under the receiver operating characteristic curve (AUC) for predicting abnormal computed tomography scans of the head; S100 calcium binding protein B (S100B, N = 6 studies, AUC range 0.67-1.00), glial fibrillary acidic protein (N = 5, AUC range 0.41-0.85), ubiquitin C-terminal hydrolase (N = 3, AUC 0.59 and 0.83), neuron specific enolase (N = 1, AUC 0.99), total tau (N = 1, AUC 0.65), and interleukin-6 (N = 1, AUC 0.61). In four of the ten prognostic studies, increased acute serum S100B levels, tumor necrosis factor-α, or interleukin-8 were associated with post-concussive symptoms or fatigue from 3 to 12 months post-injury.

CONCLUSIONS

The largest amount of evidence supported the potential use of S100B, glial fibrillary acidic protein, and UCH-L1, but there was mixed accuracy for diagnosis and prognostication for all biomarkers in pediatric mTBI.

Brain-Derived Neurotrophic Factor in Pediatric Acquired Brain Injury and Recovery

We review emerging preclinical and clinical evidence regarding brain-derived neurotrophic factor (BDNF) protein, genotype, and DNA methylation (DNAm) as biomarkers of outcomes in three important etiologies of pediatric acquired brain injury (ABI), traumatic brain injury, global cerebral ischemia, and stroke. We also summarize evidence suggesting that BDNF is (1) involved in the biological embedding of the psychosocial environment, (2) responsive to rehabilitative therapies, and (3) potentially modifiable. BDNF's unique potential as a biomarker of neuroplasticity and neural repair that is reflective of and responsive to both pre- and post-injury environmental influences separates it from traditional protein biomarkers of structural brain injury with exciting potential to advance pediatric ABI management by increasing the accuracy of prognostic tools and informing clinical decision making through the monitoring of therapeutic effects.

Sports-Related Concussion Assessment: A New Physiological, Biomechanical, and Cognitive Methodology Incorporating a Randomized Controlled Trial Study Protocol

BACKGROUND

Taking part in moderate-to-vigorous exercise in contact sports on a regular basis may be linked to an increase in cerebrovascular injury and head trauma. Validated objective measures are lacking in the initial post-event diagnosis of head injury. The exercise style, duration, and intensity may also confound diagnostic indicators. As a result, we propose that the new Interdisciplinary Group in Movement & Performance from Acute & Chronic Head Trauma (IMPACT) analyze a variety of functional (biomechanical and motor control) tests as well as related biochemistry to see how they are affected by contact in sports and head injury. The study's goal will be to look into the performance and physiological changes in rugby players after a game for head trauma and injury.

METHODS

This one-of-a-kind study will use a randomized controlled trial (RCT) utilizing a sport participation group and a non-participation control group. Forty male rugby 7 s players will be recruited for the study and allocated randomly to the experimental groups. The intervention group will participate in three straight rugby matches during a local 7 s rugby event. At the pre-match baseline, demographic and anthropometric data will be collected. This will be followed by the pre-match baseline collection of biochemical, biomechanical, and cognitive-motor task data. After three consecutive matches, the same measures will be taken. During each match, a notational analysis will be undertaken to obtain contact information. All measurements will be taken again 24, 48, and 72 h after the third match.

DISCUSSION

When the number of games increases owing to weariness and/or stressful circumstances, we expect a decline in body movement, coordination, and cognitive-motor tasks. Changes in blood biochemistry are expected to correspond to changes in biomechanics and cognitive-motor processes. This research proposal will generate considerable, ecologically valid data on the occurrence of head trauma events under game conditions, as well as the influence of these events on the biological systems of the performers. This will lead to a greater understanding of how sports participants react to exercise-induced injuries. This study's scope will have far-reaching ramifications for doctors, coaches, managers, scientists, and sports regulatory bodies concerned with the health and well-being of athletic populations at all levels of competition, including all genders and ages.

Inflammatory cytokines associated with mild traumatic brain injury and clinical outcomes: a systematic review and meta-analysis

Mild traumatic brain injuries (mTBIs) trigger a neuroinflammatory response, which leads to perturbations in the levels of inflammatory cytokines, resulting in a distinctive profile. A systematic review and meta-analysis were conducted to synthesize data related to levels of inflammatory cytokines in patients with mTBI. The electronic databases EMBASE, MEDLINE, and PUBMED were searched from January 2014 to December 12, 2021. A total of 5,138 articles were screened using a systematic approach based on the PRISMA and R-AMSTAR guidelines. Of these articles, 174 were selected for full-text review and 26 were included in the final analysis. The results of this study demonstrate that within 24 hours, patients with mTBI have significantly higher levels of Interleukin-6 (IL-6), Interleukin-1 Receptor Antagonist (IL-1RA), and Interferon-γ (IFN-γ) in blood, compared to healthy controls in majority of the included studies. Similarly one week following the injury, patients with mTBI have higher circulatory levels of Monocyte Chemoattractant Protein-1/C-C Motif Chemokine Ligand 2 (MCP-1/CCL2), compared to healthy controls in majority of the included studies. The results of the meta-analysis also confirmed these findings by demonstrating significantly elevated blood levels of IL-6, MCP-1/CCL2, and Interleukin-1 beta (IL-1β) in the mTBI population compared to healthy controls (p < 0.0001), particularly in the acute stages (<7 days). Furthermore, it was found that IL-6, Tumor Necrosis Factor-alpha (TNF-α), IL-1RA, IL-10, and MCP-1/CCL2 were associated with poor clinical outcomes following the mTBI. Finally, this research highlights the lack of consensus in the methodology of mTBI studies that measure inflammatory cytokines in the blood, and also provides direction for future mTBI research.

Chikungunya virus infection induces ultrastructural changes and impaired neuronal differentiation of human neurospheres

Chikungunya virus (CHIKV) is an arthropod-borne virus recently associated with large outbreaks in many parts of the world. Infection is typically manifested as a febrile and self-limited illness, characterized by joint pain and myalgia, albeit severe neurological manifestations are also reported. Although CHIKV is not recognized as a truly neurotropic virus, neurons, astrocytes, and oligodendrocytes are susceptible to infection in vitro. Here we employed a model of 3D cell culture to obtain neurospheres from ATRA/BNDF differentiated human neuroblastoma cells. We demonstrate that CHIKV is able to establish a productive infection, resulting in ultrastructural changes in cell morphology and impaired neuronal differentiation. Ultrastructural analysis of neurospheres infected with CHIKV during neuronal differentiation revealed diminished neuron dendrite formation, accumulation of viral particles associated with the plasma membrane, numerous cell vacuoles, and swollen mitochondria. Apoptotic cells were significantly increased at 72 h post-infection. Compared to Zika virus, a well-characterized neurotropic arbovirus, CHIKV infection resulted in a more discrete, albeit detectable upregulation of IL-6 levels. Finally, we found that CHIKV infection resulted in an altered profile expression, mainly downregulation, of a group of transcription factors named Hox genes. Altogether our findings highlight important features of CHIKV in the CNS, as well as the feasibility of neurospheres as robust experimental models that can support further studies for novel pharmacological interventions.

UCHL1, besides leptin and fibronectin, also could be a sensitive marker of the relapsing-remitting type of multiple sclerosis

Research on the markers of immunoregulatory response in multiple sclerosis (MS) is still of great importance. The aim of our study was the evaluation of leptin, fibronectin, and UCHL1 concentrations as potential biomarkers of a relapsing-remitting type of MS (RRMS). Surface Plasmon Resonance Imaging (SPRI) biosensors were used for the evaluation of proteins concentrations in 100 RRMS patients and 46 healthy volunteers. Plasma leptin, fibronectin, and UCHL1 concentrations were significantly higher in RRMS patients compared to the control group (p < 0.001, respectively). UCHL1 concentration evaluation revealed the highest diagnostic sensitivity (100%) and negative predictive value (100%) in differentiating MS patients from healthy individuals. There was no significant difference in the UCHL1 concentrations depending on the patient's sex, the presence of relapse within the last 24 months, and the EDSS value (p > 0.05, respectively). In RRMS patients UCHL1 concentration positively correlated with fibronectin levels (r = 0.3928; p < 0.001). In the current cohort of patients plasma UCHL1 concentration was independent of the time of MS relapse and the severity of neurological symptoms. Thus current study may indicate that plasma UCHL1, besides leptin and fibronectin, also could be a promising high-sensitive potential biomarker of relapsing-remitting type of MS. However, these results should be validated with a larger group of patients, taking into account neuroimaging and cerebrospinal fluid analysis data, and by comparing them to patients with other neurological diseases as a control group.

Ubiquitin carboxyl-terminal esterase L1 is not elevated in the serum of concussed rugby players: an observational cross-sectional study

Concussion diagnosis is complicated by a lack of objective measures. Ubiquitin carboxyl-terminal esterase L1 (UCHL1) is a biomarker that has been shown to increase following traumatic brain injury but has not been investigated in concussed athletes on the sideline of athletic events. Therefore, this study was conducted to determine if UCHL1 can be used to aid in sideline concussion diagnosis. Blood was taken via standard venipuncture from a recreationally active control group, a group of rugby players prior to match play (pre-match), rugby players following match-play (match-control), and rugby players after suffering a sport-related concussion (SRC). UCHL1 was not significantly different among groups (p > 0.05) and was unable to distinguish between SRC and controls (AUROC < 0.400, p > 0.05). However, when sex-matched data were used, it was found that the female match-control group had a significantly higher serum UCHL1 concentration than the pre-match group (p = 0.041). Differences were also found in serum UCHL1 concentrations between male and female athletes in the match-control group (p = 0.007). This study does not provide evidence supporting the use of UCHL1 in sideline concussion diagnosis when blood is collected soon after concussion but does show differences in serum UCHL1 accumulation between males and females.

The Role of Neuroinflammatory Mediators in the Pathogenesis of Traumatic Brain Injury: A Narrative Review

Traumatic brain injury (TBI) is a debilitating acquired neurological disorder that afflicts nearly 74 million people worldwide annually. TBI has been classified as more than just a single insult because of its associated risk toward various long-term neurological and neurodegenerative disorders. This risk may be triggered by a series of postinjury secondary molecular and cellular pathology, which may be dependent on the severity of the TBI. Among the secondary injury mechanisms, neuroinflammation may be the most crucial as it may exacerbate brain damage and lead to fatal consequences when prolonged. This Review aimed to elucidate the influence of neuroinflammatory mediators on the TBI functional and pathological outcomes, particularly focusing on inflammatory cytokines which were associated with neuronal dysfunctions in the acute and chronic stages of TBI. These cytokines include interleukins (IL) such as IL-1(beta)β, IL-4, IL-6, IL8, IL-10, IL-18, IL-33 and tumor necrosis factor alpha (TNF-α), which have been extensively studied. Apart from these, IL-2, interferon gamma (IFN-γ), and transforming growth factor-beta (TGF-β) may also play a significant role in the pathogenesis of TBI. These neuroinflammatory mediators may trigger a series of pathological events such as cell death, microglial suppression, and increased catecholaminergic activity. Interestingly, in the acute phase of TBI, most of these mediators may also play a neuroprotective role by displaying anti-inflammatory properties, which may convert to a pro-inflammatory action in the chronic stages post TBI. Early identification and treatment of these mediators may help the development of more effective treatment options for TBI.

Blood-based biomarkers of inflammation in mild traumatic brain injury: A systematic review

VISSER, K., M. Koggel, J. Blaauw, H.J.v.d. Horn, B. Jacobs, and J.v.d. Naalt. Blood based biomarkers of inflammation in mild traumatic brain injury: A systematic review. NEUROSCI BIOBEHAV REV XX(X) XXX-XXX, 2021. - Inflammation is an important secondary physiological response to traumatic brain injury (TBI). Most of the current knowledge on this response is derived from research in moderate and severe TBI. In this systematic review we summarize the literature on clinical studies measuring blood based inflammatory markers following mild traumatic brain injury (mTBI) and identify the value of inflammatory markers as biomarkers. Twenty-three studies were included. This review suggests a distinct systemic inflammatory response following mTBI, quantifiable within 6 h up to 12 months post-injury. Interleukin-6 is the most promising biomarker for the clinical diagnosis of brain injury while interleukin-10 is a potential candidate for triaging CT scans. The diagnostic and prognostic utility of inflammatory markers may be more fully appreciated as a component of a panel of biomarkers. However, discrepancies in study design, analysis and reporting make it difficult to draw any definite conclusions. For the same reasons, a meta-analysis was not possible. We provide recommendations to follow standardized methodologies to allow for reproducibility of results in future studies.