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 ◽  
...  

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.

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

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.


2019 ◽  
Vol 20 (24) ◽  
pp. 6125 ◽  
Author(s):  
Ning Liu ◽  
Yinghua Jiang ◽  
Joon Yong Chung ◽  
Yadan Li ◽  
Zhanyang Yu ◽  
...  

Our laboratory and others previously showed that Annexin A2 knockout (A2KO) mice had impaired blood–brain barrier (BBB) development and elevated pro-inflammatory response in macrophages, implying that Annexin A2 (AnxA2) might be one of the key endogenous factors for maintaining homeostasis of the neurovascular unit in the brain. Traumatic brain injury (TBI) is an important cause of disability and mortality worldwide, and neurovascular inflammation plays an important role in the TBI pathophysiology. In the present study, we aimed to test the hypothesis that A2KO promotes pro-inflammatory response in the brain and worsens neurobehavioral outcomes after TBI. TBI was conducted by a controlled cortical impact (CCI) device in mice. Our experimental results showed AnxA2 expression was significantly up-regulated in response to TBI at day three post-TBI. We also found more production of pro-inflammatory cytokines in the A2KO mouse brain, while there was a significant increase of inflammatory adhesion molecules mRNA expression in isolated cerebral micro-vessels of A2KO mice compared with wild-type (WT) mice. Consistently, the A2KO mice brains had a significant increase in leukocyte brain infiltration at two days after TBI. Importantly, A2KO mice had significantly worse sensorimotor and cognitive function deficits up to 28 days after TBI and significantly larger brain tissue loss. Therefore, these results suggested that AnxA2 deficiency results in exacerbated early neurovascular pro-inflammation, which leads to a worse long-term neurologic outcome after TBI.


2021 ◽  
Vol 23 (1) ◽  
pp. 163-168
Author(s):  
N. G. Plekhova ◽  
I. V. Radkov ◽  
S. V. Zinoviev ◽  
V. B. Shumatov

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.


2021 ◽  
Author(s):  
Maxwell Eisenbaum ◽  
Andrew Pearson ◽  
Arissa Gratkowski ◽  
Benoit Mouzon ◽  
Michael Mullan ◽  
...  

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.


Pharmaceutics ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 473 ◽  
Author(s):  
Badrul Alam Bony ◽  
Forrest M. Kievit

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.


2017 ◽  
Vol 37 (10) ◽  
pp. 3422-3432 ◽  
Author(s):  
Hong Zhang ◽  
Wenzhu Wang ◽  
Shanshan Jiang ◽  
Yi Zhang ◽  
Hye-Young Heo ◽  
...  

The purpose of this study was to explore the capability and uniqueness of amide proton transfer-weighted (APTw) imaging in the detection of primary and secondary injury after controlled cortical impact (CCI)-induced traumatic brain injury (TBI) in rats. Eleven adult rats had craniotomy plus CCI surgery under isoflurane anesthesia. Multi-parameter MRI data were acquired at 4.7 T, at eight time points (1, 6 h, and 1, 2, 3, 7, 14, and 28 days after TBI). At one and six hours post-injury, average APTw signal intensities decreased significantly in the impacted and peri-lesional areas due to tissue acidosis. A slightly high APTw signal was seen in the core lesion area with respect to the peri-lesional area, which was due to hemorrhage, as shown by T2*w. After the initial drop, the APTw signals dramatically increased in some peri-lesional areas at two and three days post-injury, likely due to the secondary inflammatory response. The use of APTw MRI has the potential to introduce a novel molecular neuroimaging approach for the simultaneous detection of ischemia, hemorrhage, and neuroinflammation in TBI.


2019 ◽  
Author(s):  
Alexandria N. Early ◽  
Amy A. Gorman ◽  
Linda J. Van Eldik ◽  
Adam D. Bachstetter ◽  
Josh M. Morganti

AbstractBackgroundOlder-age individuals are at the highest risk for disability from a traumatic brain injury (TBI). Astrocytes are the most numerous glia in the brain, necessary for brain function, yet there is little known about unique responses of astrocytes in the aged-brain following TBI.MethodsOur approach examined astrocytes in young adult, 4-month-old, versus aged, 18-month-old mice, at 1, 3, and 7 days post-TBI. We selected these time points to span the critical period in the transition from acute injury to presumably irreversible tissue damage and disability. Two approaches were used to define the astrocyte contribution to TBI by age interaction: 1) tissue histology and morphological phenotyping, and 2) transcriptomics on enriched astrocytes from the injured brain.ResultsAging was found to have a profound effect on the TBI-induced loss of homeostatic astrocyte function needed for maintaining water transport and edema – namely, aquaporin-4. The loss of homoeostatic responses was coupled with a progressive exacerbation of astrogliosis in the aged brain as a function of time after injury. Moreover, clasmatodendrosis, an underrecognized astrogliopathy, was found to be significantly increased in the aged brain, but not in the young brain. As a function of TBI, we observed a transitory refraction in the number of these astrocytes, which rebounded by 7 days post-injury in the aged brain. The transcriptomics found disproportionate changes in genes attributed to reactive astrocytes, inflammatory response, complement pathway, and synaptic support in aged mice following TBI compared to young mice. Additionally, our data highlight that TBI did not evoke a clear alignment with previously defined “A1/A2” dichotomy of reactive astrogliosis.ConclusionsOverall, our findings point toward a progressive phenotype of aged astrocytes following TBI that we hypothesize to be maladaptive, shedding new insights into potentially modifiable astrocyte-specific mechanisms that may underlie increased fragility of the aged brain to trauma.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Maxwell Eisenbaum ◽  
Andrew Pearson ◽  
Arissa Gratkowski ◽  
Benoit Mouzon ◽  
Michael Mullan ◽  
...  

AbstractRepetitive 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 of biotin-labeled tau, the levels of exogenous labeled 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 in the chronic phase following r-mTBI (> 3 months post-injury). Lastly, angiopoietin-1, a mural cell-derived protein governing endothelial Mfsd2a expression, was secreted from r-mTBI cerebrovessels to a greater extent than r-sham animals. Altogether, 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.


2021 ◽  
Vol 5 (4) ◽  
pp. 1218-1222
Author(s):  
Yuliarni Syafrita ◽  
Nora Fitri

Background : Traumatic brain injury is still the main cause of death and disability in productive age. Assessment the level of consciousness and imaging examinations after a brain injury can not always describe the severity of damage in the brain, this is because the pathological process is still ongoing due to secondary brain injury. Therefore, it is necessary to examine biomarkers that can describe the severity of the pathological process that occurs. The purpose of this study was to assess serum neuron-specific enolase (NSE) levels and their relationship to the severity and outcome of a traumatic brain injury. Methods : A cross sectional design was conducted in the emergency department of DR M Djamil Hospital, Padang. There were 72 patients who met the inclusion criteria. A Glasgow Coma Scale examination was performed to assess the severity of brain injury and examination of NSE serum levels at 48 hours post- injury using ELISA technique and assess the Glasgow outcome scale (GOS) at 6 weeks post-injury. Data analysis using SPSS 22 program, the results are significance if the p value <0.05  Results : The average NSE level was higher in severe brain injuries than moderate and mild brain injuries and this difference was statistically significant (p<0.05).  The NSE serum levels were higher in poor outcomes than in good outcomes and this difference was statistically significant (p<0.05).  Conclusion : High NSE serum levels in the acute phase were associated with the severity of the brain injury and poor outcome 6 weeks after the brain injury. 


2021 ◽  
Author(s):  
Akshita Jade Kumar ◽  
Supinder Singh Bedi ◽  
Naama Toledano-Furman ◽  
Louis Carrillo ◽  
Fanni Cardenas ◽  
...  

Abstract Background: Traumatic brain injury (TBI) is a systemic injury that disrupts a complex arrangement of interacting cells in the brain and in the gastrointestinal tract (GI). Disruption in the brain results in neuroinflammation, in which microglia are a central component along with cytokines and other soluble factors [pro and anti-inflammatory microglia (M1:M2)]. Disruption in the GI due to TBI results in a systemic inflammation which is dependent upon the gut microbiome (GM). Gut microbiome can influence microglia in the brain via the gut-brain axis. In order to determine if the microbiome-microglia connections via the gut-brain axis can be modulated, we used probiotics and antibiotics in a rodent TBI model to evaluate the microbiome-microglial connections in acute and chronic experiments.Methods: The temporal effects of treatment (probiotics or antibiotics) were used to evaluate the gut-associated lymphoid tissue (GALT) influence on the microglial response at 72 hours or 21 days after a cortical contusion injury (CCI), a rodent model of TBI. Injured animals received daily probiotics, antibiotics, or no treatment. Sham-injured animals (controls) did not receive any treatment.Results: Twenty-one days of probiotic treatment attenuated the pro-inflammatory response of microglia (M1:M2) after CCI. The post-injury inflammatory response was heightened in the GALT with antibiotic-induced dysbiosis which resulted in amplification of the pro-inflammatory microglial response. Conclusions: Probiotic treatment after TBI is a potential therapeutic in attenuating microglial activation through anti-inflammatory signaling.


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