scholarly journals The CNS lymphatic system modulates the adaptive neuro-immune response in the perilesional cortex in a mouse model of traumatic brain injury

2019 ◽  
Author(s):  
Wojciechowski Sara ◽  
Vihma Maria ◽  
Galbardi Barbara ◽  
Virenque Anaïs ◽  
Meike H. Keuters ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Immune Response ◽  
T Cells ◽  
Brain Injury ◽  
Lymphatic Vessels ◽  
Lesion Size ◽  
Lesion Volume ◽  
Post Injury ◽  
Circulating T Cells ◽  
The Brain

AbstractRationaleThe recently discovered meningeal lymphatic vessels (mLVs) have been proposed to be the missing link between the immune and the central nervous systems. The role of mLVs in modulating the neuro-immune response following a brain injury, however, has not been analyzed. Parenchymal T lymphocyte infiltration has been previously reported as part of secondary events after traumatic brain injury (TBI), suggestive of an adaptive neuro-immune response. The phenotype of these cells has remained mostly uncharacterized. In this study, we identified the subpopulations of T cells infiltrating the perilesional areas 30 days post-injury (an early-chronic time point). Furthermore, we analyzed how the lack of mLVs affects the magnitude and the type of immune response in the brain after TBI.MethodsTBI was induced in K14-VEGFR3-Ig transgenic (TG) mice or in their littermate controls (WT; wild type), applying a controlled cortical impact (CCI). One month after TBI, T cells were isolated from cortical areas ipsilateral or contralateral to the trauma and from the spleen, then characterized by flow cytometry. Lesion size in each animal was evaluated by MRI.ResultsIn both WT and TG-CCI mice, we found a prominent T cell infiltration in the brain confined to the perilesional cortex and hippocampus. The majority of infiltrating T cells were cytotoxic CD8+ expressing a CD44hiCD69+ phenotype, suggesting that these are effector resident memory T cells. K14-VEGFR3-Ig mice showed a significant reduction of infiltrating CD4+ T lymphocytes, implying that mLVs are important in establishing a proper neuro-immune response. Extension of the lesion (measured as lesion volume from MRI) did not differ between the genotypes. Finally, TBI did not relate with alterations in peripheral circulating T cells, as assessed one month after injury induction.ConclusionsOur data support the hypothesis that mLVs are pivotal for a proper and specific neuro-immune response after TBI, which is principally mediated by the resident memory CD8+ T cells.

scholarly journals Developmental Dysfunction of the Central Nervous System Lymphatics Modulates the Adaptive Neuro-Immune Response in the Perilesional Cortex in a Mouse Model of Traumatic Brain Injury

2021 ◽  
Vol 11 ◽  
Author(s):  
Sara Wojciechowski ◽  
Anaïs Virenque ◽  
Maria Vihma ◽  
Barbara Galbardi ◽  
Erin Jane Rooney ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Central Nervous System ◽  
Immune Response ◽  
T Cells ◽  
Nervous System ◽  
Brain Injury ◽  
T Cell ◽  
Lesion Volume ◽  
The Central Nervous System ◽  
The Brain

RationaleThe recently discovered meningeal lymphatic vessels (mLVs) have been proposed to be the missing link between the immune and the central nervous system. The role of mLVs in modulating the neuro-immune response following a traumatic brain injury (TBI), however, has not been analyzed. Parenchymal T lymphocyte infiltration has been previously reported as part of secondary events after TBI, suggestive of an adaptive neuro-immune response. The phenotype of these cells has remained mostly uncharacterized. In this study, we identified subpopulations of T cells infiltrating the perilesional areas 30 days post-injury (an early-chronic time point). Furthermore, we analyzed how the lack of mLVs affects the magnitude and the type of T cell response in the brain after TBI.MethodsTBI was induced in K14-VEGFR3-Ig transgenic (TG) mice or in their littermate controls (WT; wild type), applying a controlled cortical impact (CCI). One month after TBI, T cells were isolated from cortical areas ipsilateral or contralateral to the trauma and from the spleen, then characterized by flow cytometry. Lesion size in each animal was evaluated by MRI.ResultsIn both WT and TG-CCI mice, we found a prominent T cell infiltration in the brain confined to the perilesional cortex and hippocampus. The majority of infiltrating T cells were cytotoxic CD8+ expressing a CD44hiCD69+ phenotype, suggesting that these are effector resident memory T cells. K14-VEGFR3-Ig mice showed a significant reduction of infiltrating CD4+ T lymphocytes, suggesting that mLVs could be involved in establishing a proper neuro-immune response. Extension of the lesion (measured as lesion volume from MRI) did not differ between the genotypes. Finally, TBI did not relate to alterations in peripheral circulating T cells, as assessed one month after injury.ConclusionsOur results are consistent with the hypothesis that mLVs are involved in the neuro-immune response after TBI. We also defined the resident memory CD8+ T cells as one of the main population activated within the brain after a traumatic injury.

scholarly journals Immunological context of brain injury

2021 ◽  
Vol 23 (1) ◽  
pp. 163-168
Author(s):  
N. G. Plekhova ◽  
I. V. Radkov ◽  
S. V. Zinoviev ◽  
V. B. Shumatov
Keyword(s):  
Traumatic Brain Injury ◽  
T Cells ◽  
Brain Injury ◽  
Positive Reaction ◽  
Mild Traumatic Brain Injury ◽  
Brain Parenchyma ◽  
Post Injury ◽  
Blood Leukocytes ◽  
Subsequent Decrease ◽  
The Brain

The parameters of several populations of immune cells (T cell populations, macrophage subpopulations) in peripheral blood and brain were studied in a clinically significant model of mild traumatic brain injury among rats. The population of resident cells of innate immunity of microglia and brain astrocytes with local tissue damage is involved in the implementation of the inflammatory response, it is also shown that in case of trauma, blood leukocytes can overcome the blood-brain barrier and penetrate the brain parenchyma. The methods of flow cytometry and immunofluorescence were used. An increase in the number of monocytes and neutrophils up to 1 day, after a mild traumatic brain injury (TBI) with a subsequent decrease to the end of the observation period was noticed. It was determined, that the number of CD45+ cells, CD3+T cells decreased at 1 days post-injury (dpi), and rose slightly by 14 dpi, the percentage of CD4+T cells continuously declined from 7 to 14 dpi, while the percentage of CD8+T cells increased from 7 to 14 dpi. With mild traumatic brain injury in animals, a significant (3-10 times) decrease in the number of microvessels with a positive reaction to the presence of SMI 71 on the 8th and 14th day after head injury was observed. Intensive staining of SMI 71 microvessels was sometimes observed with an increase in the area of a positive reaction. Thin positive deposits of the reaction product are observed in the brain of healthy animals around the wall of the microvessel. In the damaged brain, CD45high/CD11b+ positive macrophages of the M1 subpopulation appeared in the brain tissue on the 2nd day after TBI and a significant amount was observed on the 8-14th day. In the corpus callosum and ipsilateral region of the striatum, the content of cells expressing CD16/11b+ reached a maximum 8 days after TBI, which correlated with a decrease in the positive response to the presence of endothelial antigen SMI 71. Thus, in the acute period of mild TBI, the presence of neuroimmunopathological processes is determined in the brain, which can subsequently result to the dysregulation of neuroimmune connections.

scholarly journals The Challenge of Managing Patients Suffering from TBI: The Utility of Multiparametric MRI

CNS Spectrums ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 178-179
Author(s):  
John L. Sherman ◽  
Laurence J. Adams ◽  
Christen F. Kutz ◽  
Deborah York ◽  
Mitchell S. Szymczak
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Family History ◽  
Diffusion Tensor ◽  
Multiparametric Mri ◽  
Psychiatric History ◽  
Post Injury ◽  
Negative Family History ◽  
Imaging Result ◽  
The Brain

AbstractTraumatic brain injury (TBI) is a complex phenomenon affecting multiple areas of the brain in multiple ways. Both right and left hemispheres are affected as well as supratentorial and infratentorial compartments. These multifocal injuries are caused by many factors including acute mechanical injury, focal intracranial hemorrhage, blunt and rotational forces, epidural and subdural hematoma, hypoxemia, hypotension, edema, axonal damage, neuronal death, gliosis and blood brain barrier disruption. Clinicians and patients benefit by precise information about the neuroanatomical areas that are affected macroscopically, microscopically and biochemically in an individual patient.Standard imaging studies are frequently negative or grossly underestimate the severity of TBI and may exacerbate and prolong patient suffering with an imaging result of “no significant abnormality”. Specifically, sophisticated imaging tools have been developed which reveal significant damage to the brain structure including atrophy, MRI spectroscopy showing variations in neuronal metabolite N-acetyl-aspartate, elevations of membrane related Choline, and the glial metabolite myo-inositol is often observed to be increased post injury. In addition, susceptibility weighted imaging (SWI) has been shown to be more reliable for detecting microbleeds versus calcifications.We have selected two TBI patients with diffuse traumatic brain injury.The first patient is a 43-year-old male who suffered severe traumatic brain injury from a motorcycle accident in 2016. Following the accident, the patient was diagnosed with seizures, major depression, and intermittent explosive disorder. He has attempted suicide and has neurobehavioral disinhibition including severe anger, agitation and irritability. He denies psychiatric history prior to TBI and has negative family history. Following the TBI, he became physically aggressive and assaultive in public with minimal provocation. He denies symptoms of thought disorder and mania. He is negative for symptoms of  cognitive decline or encephalopathy.The second patient is a 49-year-old male who suffered at least 3 concussive blasts in the Army and a parachute injury. Following the last accident, the patient was diagnosed with major depressive disorder, panic disorder, PTSD and generalized anxiety disorder. He denies any psychiatric history prior to TBI including negative family history of psychiatric illness. In addition, he now suffers from nervousness, irritability, anger, emotional lability and concurrent concentration issues, problems completing tasks and alterations in memory.Both patients underwent 1.5T multiparametric MRI using standard T2, FLAIR, DWI and T1 sequences, and specialized sequences including susceptibility weighted (SWAN/SWI), 3D FLAIR, single voxel MRI spectroscopy (MRS), diffusion tensor imaging (DTI), arterial spin labeling perfusion (ASL) and volumetric MRI (NeuroQuant). Importantly, this exam can be performed in 30–45 minutes and requires no injections other than gadolinium in some patients. We will discuss the insights derived from the MRI which detail the injured areas, validate the severity of the brain damage, and provide insight into the psychological, motivational and physical disabilities that afflict these patients. It is our expectation that this kind of imaging study will grow in value as we link specific patterns of injury to specific symptoms and syndromes resulting in more targeted therapies in the future.

scholarly journals A combination antioxidant therapy to inhibit NOX2 and activate Nrf2 decreases secondary brain damage and improves functional recovery after traumatic brain injury

2017 ◽  
Vol 38 (10) ◽  
pp. 1818-1827 ◽  
Author(s):  
Raghavendar Chandran ◽  
TaeHee Kim ◽  
Suresh L Mehta ◽  
Eshwar Udho ◽  
Vishal Chanana ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Motor Function ◽  
Neurological Dysfunction ◽  
Vehicle Group ◽  
Lesion Volume ◽  
Post Injury ◽  
Cortical Contusion ◽  
Nrf2 Activator

Uncontrolled oxidative stress contributes to the secondary neuronal death that promotes long-term neurological dysfunction following traumatic brain injury (TBI). Surprisingly, both NADPH oxidase 2 (NOX2) that increases and transcription factor Nrf2 that decreases reactive oxygen species (ROS) are induced after TBI. As the post-injury functional outcome depends on the balance of these opposing molecular pathways, we evaluated the effect of TBI on the motor and cognitive deficits and cortical contusion volume in NOX2 and Nrf2 knockout mice. Genetic deletion of NOX2 improved, while Nrf2 worsened the post-TBI motor function recovery and lesion volume indicating that decreasing ROS levels might be beneficial after TBI. Treatment with either apocynin (NOX2 inhibitor) or TBHQ (Nrf2 activator) alone significantly improved the motor function after TBI, but had no effect on the lesion volume, compared to vehicle control. Whereas, the combo therapy (apocynin + TBHQ) given at either 5 min/24 h or 2 h/24 h improved motor and cognitive function and decreased cortical contusion volume compared to vehicle group. Thus, both the generation and disposal of ROS are important modulators of oxidative stress, and a combo therapy that prevents ROS formation and potentiates ROS disposal concurrently is efficacious after TBI.

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

Antioxidants ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 124 ◽  
Author(s):  
Elena V. Stelmashook ◽  
Nickolay K. Isaev ◽  
Elisaveta E. Genrikhs ◽  
Svetlana V. Novikova
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Cortical Lesion ◽  
Lesion Volume ◽  
Negative Effects ◽  
Behavioral Deficits ◽  
Secondary Damage ◽  
Long Time ◽  
The Brain ◽  
Brain Water

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.

scholarly journals Administration of a 20-Hydroxyeicosatetraenoic Acid Synthesis Inhibitor Improves Outcome in a Rat Model of Pediatric Traumatic Brain Injury

2019 ◽  
Vol 41 (3-4) ◽  
pp. 166-176 ◽  
Author(s):  
Shiyu Shu ◽  
Zhi Zhang ◽  
Dawn Spicer ◽  
Ewa Kulikowicz ◽  
Ke Hu ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Ischemia Reperfusion ◽  
Memory Task ◽  
Male Rats ◽  
Lesion Volume ◽  
Hydroxyeicosatetraenoic Acid ◽  
Post Injury ◽  
Synthesis Inhibitor ◽  
Tnf Α

The arachidonic acid pathway metabolite 20-hydroxyeicosatetraenoic acid (20-HETE) contributes to ischemia/reperfusion brain injury. Inhibition of 20-HETE formation can protect the developing brain from global ischemia. Here, we examined whether treatment with the 20-HETE synthesis inhibitor N-hydroxy-N-4-butyl-2-methylphenylformamidine (HET0016) can protect the immature brain from traumatic brain injury (TBI). Male rats at postnatal day 9–10 underwent controlled cortical impact followed by intraperitoneal injection with vehicle or HET0016 (1 mg/kg, 5 min and 3 h post-injury). HET0016 decreased the lesion volume by over 50% at 3 days of recovery, and this effect persisted at 30 days as the brain matured. HET0016 decreased peri-lesion gene expression of proinflammatory cytokines (tumor necrosis factor-α [TNF-α], interleukin-1β [IL-1β]) at 1 day and increased reparative cytokine (IL-4, IL-10) expression at 3 days. It also partially preserved microglial ramified processes, consistent with less activation. HET0016 decreased contralateral hindlimb foot faults and improved outcome on the novel object recognition memory task 30 days after TBI. In cultured BV2 microglia, HET0016 attenuated the lipopolysaccharide-evoked increase in release of TNF-α. Our data show that HET0016 improves acute and long-term histologic and functional outcomes, in association with an attenuated neuroinflammatory response after contusion of an immature rat brain.

scholarly journals Microglial Metabolism After Pediatric Traumatic Brain Injury – Overlooked Bystanders or Active Participants?

2021 ◽  
Vol 11 ◽  
Author(s):  
Aria C. Shi ◽  
Ursula Rohlwink ◽  
Susanna Scafidi ◽  
Sujatha Kannan
Keyword(s):  
Traumatic Brain Injury ◽  
Immune Response ◽  
Brain Injury ◽  
Innate Immune Response ◽  
Innate Immune ◽  
Metabolic Alterations ◽  
Microglial Phenotype ◽  
Integral Role ◽  
And Behavior ◽  
The Brain

Microglia play an integral role in brain development but are also crucial for repair and recovery after traumatic brain injury (TBI). TBI induces an intense innate immune response in the immature, developing brain that is associated with acute and chronic changes in microglial function. These changes contribute to long-lasting consequences on development, neurologic function, and behavior. Although alterations in glucose metabolism are well-described after TBI, the bulk of the data is focused on metabolic alterations in astrocytes and neurons. To date, the interplay between alterations in intracellular metabolic pathways in microglia and the innate immune response in the brain following an injury is not well-studied. In this review, we broadly discuss the microglial responses after TBI. In addition, we highlight reported metabolic alterations in microglia and macrophages, and provide perspective on how changes in glucose, fatty acid, and amino acid metabolism can influence and modulate the microglial phenotype and response to injury.

scholarly journals Temporal Profile of Transporter mRNA Expression in the Brain after Traumatic Brain Injury in Developing Rats

2019 ◽  
Author(s):  
Solomon M. Adams ◽  
Fanuel T. Hagos ◽  
Jeffrey P. Cheng ◽  
Robert S. B. Clark ◽  
Patrick M. Kochanek ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Mrna Expression ◽  
Neurovascular Unit ◽  
Post Injury ◽  
Adult Rats ◽  
Order Of Magnitude ◽  
Liver And Kidney ◽  
The Central Nervous System ◽  
The Brain

ABSTRACTTraumatic brain injury (TBI) is a leading cause of death in children and young adults; however, new pharmacologic approaches have failed to improve outcomes in clinical trials. Transporter proteins are central to the maintenance of homeostasis within the neurovascular unit, and regulate drug penetration into the brain. Our objective was to measure transporter temporal changes in expression in the hippocampus and cortex after experimental TBI in developing rats. We also evaluated the expression of transporters in brain, liver, and kidney across the age spectrum in both pediatric and adult rats. Eighty post-natal day (PND)-17 rats and four adult rats were randomized to receive controlled cortical impact (CCI), sham surgery, or no surgery. mRNA transcript counts for 27 ATP-binding cassette and solute carrier transporters were measured in the hippocampus, cortex, choroid plexus, liver, and kidney at 3h, 12h, 24h, 72h, 7d, and 14d post injury. After TBI, the expression of many transporters (Abcc2, Slc15a2, Slco1a2) decreased significantly in the first 24 hours, with a return to baseline over 7-14 days. Some transporters (Abcc4, Abab1a/b, Slc22a4) showed a delayed increase in expression. Baseline expression of transporters was of a similar order of magnitude in brain tissues relative to liver and kidney. Findings suggest that transporter-regulated processes may be impaired in the brain early after TBI and are potentially involved in the recovery of the neurovascular unit. Our data also suggest that transport-dependent processes in the brain are of similar importance as those seen in organs involved in drug metabolism and excretion.Significance StatementBaseline transporter mRNA expression in the central nervous system is of similar magnitude as liver and kidney, and experimental traumatic brain injury is associated with acute decrease in expression of several transporters, while others show delayed increase or decrease in expression. Pharmacotherapy following traumatic brain injury should consider potential pharmacokinetic changes associated with transporter expression.

scholarly journals Influence of Traumatic Brain Injury on Extracellular Tau Elimination at the Blood-Brain Barrier

2021 ◽  
Author(s):  
Maxwell Eisenbaum ◽  
Andrew Pearson ◽  
Arissa Gratkowski ◽  
Benoit Mouzon ◽  
Michael Mullan ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Blood Brain Barrier ◽  
Head Trauma ◽  
Brain Barrier ◽  
Post Injury ◽  
Caveolin 1 ◽  
Mural Cells ◽  
The Brain ◽  
Angiopoietin 1

Abstract Repetitive head trauma has been associated with the accumulation of tau species in the brain. Our prior work showed brain vascular mural cells contribute to tau processing in the brain, and that these cells progressively degenerate following repetitive mild traumatic brain injury (r-mTBI). The current studies investigated the role of the cerebrovasculature in the elimination of extracellular tau from the brain, and the influence of r-mTBI on these processes. Following intracranial injection, the levels of exogenous tau residing in the brain were elevated in a mouse model of r-mTBI at 12 months post-injury compared to r-sham mice, indicating reduced tau elimination from the brain following head trauma. This may be the result of decreased caveolin-1 mediated tau efflux at the blood-brain barrier (BBB), as the caveolin inhibitor, methyl-β-cyclodextrin, significantly reduced tau uptake in isolated cerebrovessels and significantly decreased the basolateral-to-apical transit of tau across an in vitro model of the BBB. Moreover, we found that the upstream regulator of endothelial caveolin-1, Mfsd2a, was elevated in r-mTBI cerebrovessels compared to r-sham, which coincided with a decreased expression of cerebrovascular caveolin-1 at 6 months post-injury. Lastly, angiopoietin-1, a mural cell-derived protein governing endothelial Mfsd2a expression, was secreted to a greater extent from r-mTBI cerebrovessels compared to r-sham animals. Thus, in the chronic phase post-injury, release of angiopoietin-1 from degenerating mural cells downregulates caveolin-1 expression in brain endothelia, resulting in decreased tau elimination across the BBB, which may describe the accumulation of tau species in the brain following head trauma.

scholarly journals A Role for Nanoparticles in Treating Traumatic Brain Injury

Pharmaceutics ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 473 ◽  
Author(s):  
Badrul Alam Bony ◽  
Forrest M. Kievit
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Treatment Options ◽  
Unmet Need ◽  
Economic Loss ◽  
Phase Iii ◽  
Target Engagement ◽  
Post Injury ◽  
The Brain

Traumatic brain injury (TBI) is one of the main causes of disability in children and young adults, as well as a significant concern for elderly individuals. Depending on the severity, TBI can have a long-term impact on the quality of life for survivors of all ages. The primary brain injury can result in severe disability or fatality, and secondary brain damage can increase the complexities in cellular, inflammatory, neurochemical, and metabolic changes in the brain, which can last decades post-injury. Thus, survival from a TBI is often accompanied by lifelong disabilities. Despite the significant morbidity, mortality, and economic loss, there are still no effective treatment options demonstrating an improved outcome in a large multi-center Phase III trial, which can be partially attributed to poor target engagement of delivered therapeutics. Thus, there is a significant unmet need to develop more effective delivery strategies to overcome the biological barriers that would otherwise inhibit transport of materials into the brain to prevent the secondary long-term damage associated with TBI. The complex pathology of TBI involving the blood-brain barrier (BBB) has limited the development of effective therapeutics and diagnostics. Therefore, it is of great importance to develop novel strategies to target the BBB. The leaky BBB caused by a TBI may provide opportunities for therapeutic delivery via nanoparticles (NP). The focus of this review is to provide a survey of NP-based strategies employed in preclinical models of TBI and to provide insights for improved NP based diagnostic or treatment approaches. Both passive and active delivery of various NPs for TBI are discussed. Finally, potential therapeutic targets where improved NP-mediated delivery could increase target engagement are identified with the overall goal of providing insight into open opportunities for NP researchers to begin research in TBI.

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