scholarly journals Chronic complement dysregulation drives neuroinflammation after traumatic brain injury: a transcriptomic study

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Amer Toutonji ◽  
Mamatha Mandava ◽  
Silvia Guglietta ◽  
Stephen Tomlinson
Keyword(s):  
Gene Expression ◽  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Complement System ◽  
Classical Pathway ◽  
Post Injury ◽  
Complement Inhibition ◽  
Time Points ◽  
Complement Gene ◽  
The Complement System

AbstractActivation of the complement system propagates neuroinflammation and brain damage early and chronically after traumatic brain injury (TBI). The complement system is complex and comprises more than 50 components, many of which remain to be characterized in the normal and injured brain. Moreover, complement therapeutic studies have focused on a limited number of histopathological outcomes, which while informative, do not assess the effect of complement inhibition on neuroprotection and inflammation in a comprehensive manner. Using high throughput gene expression technology (NanoString), we simultaneously analyzed complement gene expression profiles with other neuroinflammatory pathway genes at different time points after TBI. We additionally assessed the effects of complement inhibition on neuropathological processes. Analyses of neuroinflammatory genes were performed at days 3, 7, and 28 post injury in male C57BL/6 mice following a controlled cortical impact injury. We also characterized the expression of 59 complement genes at similar time points, and also at 1- and 2-years post injury. Overall, TBI upregulated the expression of markers of astrogliosis, immune cell activation, and cellular stress, and downregulated the expression of neuronal and synaptic markers from day 3 through 28 post injury. Moreover, TBI upregulated gene expression across most complement activation and effector pathways, with an early emphasis on classical pathway genes and with continued upregulation of C2, C3 and C4 expression 2 years post injury. Treatment using the targeted complement inhibitor, CR2-Crry, significantly ameliorated TBI-induced transcriptomic changes at all time points. Nevertheless, some immune and synaptic genes remained dysregulated with CR2-Crry treatment, suggesting adjuvant anti-inflammatory and neurotropic therapy may confer additional neuroprotection. In addition to characterizing complement gene expression in the normal and aging brain, our results demonstrate broad and chronic dysregulation of the complement system after TBI, and strengthen the view that the complement system is an attractive target for TBI therapy.

scholarly journals Highly Sensitive Single Molecular Array Immunoassay Measurement of t-Tau, NF-L, GFAP, and UCH-L1 Biomarkers in Acute Concussion/Mild Traumatic Brain Injury (mTBI) Patient Serum and Saliva Samples

Neurology ◽  
2019 ◽  
Vol 93 (14 Supplement 1) ◽  
pp. S19.3-S20
Author(s):  
Ahmed Chenna ◽  
Christos Petropoulos ◽  
John Winslow
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Mild Traumatic Brain Injury ◽  
Limited Information ◽  
Post Injury ◽  
Time Points ◽  
Highly Sensitive ◽  
Biomarker Analysis ◽  
T Tau ◽  
Control Samples

ObjectiveTo determine if t-Tau, NF-L, GFAP and UCH-L1 protein biomarkers are elevated in early time points of acute concussion/mild traumatic brain injury patient serum and saliva, relative to control samples.Backgroundt-Tau, NF-L, GFAP and UCH-L1 levels have been reported to increase in cerebral spinal fluid (CSF) and blood following head trauma within 24 hours or longer, and are candidate diagnostic and prognostic biomarkers of concussion and mild to moderate TBI. However, limited information exists on the relationship between these biomarkers at short time points post-injury, and detectability in saliva of mTBI patients.Design/MethodsBiomarker analysis of serum from a total of 120 participants, derived from two independent sample groups consisting of 60 concussion/mTBI patients each, with blood collected within 1-4 hr and 8-16 hr post-injury, respectively, was compared with 30 healthy control sera. Saliva samples were collected after 8-16 hr post-injury from a n = 30 subset of the same patients. Quanterix Simoa 4-plex immunoassay was used for highly sensitive measurements of these biomarkers.ResultsMedian levels of NF-L, GFAP and UCH-L1 were significantly higher in independent sets of patient serum samples (n = 60 each), both at early (1–4 hr) and later (8–16 hr) time points post-mTBI/concussion, relative to control samples (n = 30) (p < 0.0001, = 0.0001, <0.0001, respectively). Low levels of t-Tau are detected, but are significantly elevated post-concussion relative to controls (p = 0.0001). Significant correlations were observed between levels of t-Tau and UCH-L1, NF-L and GFAP, and t-Tau and GFAP in both post-injury time-point groups, and between NF-L and UCH-L1 levels in the 8-16 hr group. The four biomarkers were detected in saliva from concussion/mTBI patients (n = 30).ConclusionsThis study supports the utility of ultra-sensitive multiplex immunoassays to detect increases in CNS proteins at high sensitivity in serum and saliva within 1-4 and 8-16 hr of concussion/mTBI.

scholarly journals Early onset senescence and cognitive impairment in a murine model of repeated mTBI

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Nicole Schwab ◽  
YoungJun Ju ◽  
Lili-Naz Hazrati
Keyword(s):  
Gene Expression ◽  
Traumatic Brain Injury ◽  
Dna Damage ◽  
Cognitive Impairment ◽  
Brain Injury ◽  
Mild Traumatic Brain Injury ◽  
Cellular Senescence ◽  
Early Gene ◽  
Dna Breaks ◽  
Post Injury

AbstractMild traumatic brain injury (mTBI) results in broad neurological symptoms and an increased risk of being diagnosed with a neurodegenerative disease later in life. While the immediate oxidative stress response and post-mortem pathology of the injured brain has been well studied, it remains unclear how early pathogenic changes may drive persistent symptoms and confer susceptibility to neurodegeneration. In this study we have used a mouse model of repeated mTBI (rmTBI) to identify early gene expression changes at 24 h or 7 days post-injury (7 dpi). At 24 h post-injury, gene expression of rmTBI mice shows activation of the DNA damage response (DDR) towards double strand DNA breaks, altered calcium and cell–cell signalling, and inhibition of cell death pathways. By 7 dpi, rmTBI mice had a gene expression signature consistent with induction of cellular senescence, activation of neurodegenerative processes, and inhibition of the DDR. At both timepoints gliosis, microgliosis, and axonal damage were evident in the absence of any gross lesion, and by 7 dpi rmTBI also mice had elevated levels of IL1β, p21, 53BP1, DNA2, and p53, supportive of DNA damage-induced cellular senescence. These gene expression changes reflect establishment of processes usually linked to brain aging and suggests that cellular senescence occurs early and most likely prior to the accumulation of toxic proteins. These molecular changes were accompanied by spatial learning and memory deficits in the Morris water maze. To conclude, we have identified DNA damage-induced cellular senescence as a repercussion of repeated mild traumatic brain injury which correlates with cognitive impairment. Pathways involved in senescence may represent viable treatment targets of post-concussive syndrome. Senescence has been proposed to promote neurodegeneration and appears as an effective target to prevent long-term complications of mTBI, such as chronic traumatic encephalopathy and other related neurodegenerative pathologies.

scholarly journals Transcriptomic Analysis of Mouse Brain After Traumatic Brain Injury Reveals That the Angiotensin Receptor Blocker Candesartan Acts Through Novel Pathways

2021 ◽  
Vol 15 ◽  
Author(s):  
Peter J. Attilio ◽  
Dustin M. Snapper ◽  
Milan Rusnak ◽  
Akira Isaac ◽  
Anthony R. Soltis ◽  
...  
Keyword(s):  
Gene Expression ◽  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Brain Region ◽  
Molecular Mechanisms ◽  
Angiotensin Receptor Blockers ◽  
Differentially Expressed ◽  
Lesion Volume ◽  
Angiotensin Receptor ◽  
Post Injury

Traumatic brain injury (TBI) results in complex pathological reactions, where the initial lesion is followed by secondary inflammation and edema. Our laboratory and others have reported that angiotensin receptor blockers (ARBs) have efficacy in improving recovery from traumatic brain injury in mice. Treatment of mice with a subhypotensive dose of the ARB candesartan results in improved functional recovery, and reduced pathology (lesion volume, inflammation and gliosis). In order to gain a better understanding of the molecular mechanisms through which candesartan improves recovery after controlled cortical impact injury (CCI), we performed transcriptomic profiling on brain regions after injury and drug treatment. We examined RNA expression in the ipsilateral hippocampus, thalamus and hypothalamus at 3 or 29 days post injury (dpi) treated with either candesartan (0.1 mg/kg) or vehicle. RNA was isolated and analyzed by bulk mRNA-seq. Gene expression in injured and/or candesartan treated brain region was compared to that in sham vehicle treated mice in the same brain region to identify genes that were differentially expressed (DEGs) between groups. The most DEGs were expressed in the hippocampus at 3 dpi, and the number of DEGs reduced with distance and time from the lesion. Among pathways that were differentially expressed at 3 dpi after CCI, candesartan treatment altered genes involved in angiogenesis, interferon signaling, extracellular matrix regulation including integrins and chromosome maintenance and DNA replication. At 29 dpi, candesartan treatment reduced the expression of genes involved in the inflammatory response. Some changes in gene expression were confirmed in a separate cohort of animals by qPCR. Fewer DEGs were found in the thalamus, and only one in the hypothalamus at 3 dpi. Additionally, in the hippocampi of sham injured mice, 3 days of candesartan treatment led to the differential expression of 384 genes showing that candesartan in the absence of injury had a powerful impact on gene expression specifically in the hippocampus. Our results suggest that candesartan has broad actions in the brain after injury and affects different processes at acute and chronic times after injury. These data should assist in elucidating the beneficial effect of candesartan on recovery from TBI.

scholarly journals Diverse Changes in Microglia Morphology and Axonal Pathology Over One Year after Mild Traumatic Brain Injury in Pigs

2020 ◽  
Author(s):  
Michael R. Grovola ◽  
Nicholas Paleologos ◽  
Daniel P. Brown ◽  
Nathan Tran ◽  
Kathryn L. Wofford ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
White Matter ◽  
Mild Traumatic Brain Injury ◽  
Periventricular White Matter ◽  
Post Injury ◽  
Mild Tbi ◽  
Time Points ◽  
Axonal Pathology ◽  
The Brain

AbstractOver 2.8 million people experience mild traumatic brain injury (TBI) in the United States each year, which may lead to long-term neurological dysfunction. The mechanical forces that occur due to TBI propagate through the brain to produce diffuse axonal injury (DAI) and trigger secondary neuroinflammatory cascades. The cascades may persist from acute to chronic time points after injury, altering the homeostasis of the brain. However, the relationship between the hallmark axonal pathology of diffuse TBI and potential changes in glial cell activation or morphology have not been established in a clinically relevant large animal model at chronic time points. In this study, we assessed tissue from pigs subjected to rapid head rotation in the coronal plane to generate mild TBI. Neuropathological assessments for axonal pathology, microglial morphological changes, and astrocyte reactivity were conducted in specimens out to 1 year post injury. We detected an increase in overall amyloid precursor protein pathology, as well as periventricular white matter and fimbria/fornix pathology after a single mild TBI. We did not detect changes in corpus callosum integrity or astrocyte reactivity. However, detailed microglial skeletal analysis revealed changes in morphology, most notably increases in the number of microglial branches, junctions, and endpoints. These subtle changes were most evident in periventricular white matter and certain hippocampal subfields, and were observed out to 1 year post injury in some cases. These ongoing morphological alterations suggest persistent change in neuroimmune homeostasis. Additional studies are needed to characterize the underlying molecular and neurophysiological alterations, as well as potential contributions to neurological deficits.

The role of the complement system in traumatic brain injury

1998 ◽  
Vol 27 (3) ◽  
pp. 243-256 ◽  
Author(s):  
Philip F Stahel ◽  
Maria C Morganti-Kossmann ◽  
Thomas Kossmann
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Complement System ◽  
The Complement System

The CCL2/CCL7/CCL12/CCR2 pathway is substantially and persistently upregulated in mice after traumatic brain injury, and CCL2 modulates the complement system in microglia

2020 ◽  
Vol 54 ◽  
pp. 101671
Author(s):  
Katarzyna Popiolek-Barczyk ◽  
Agata Ciechanowska ◽  
Katarzyna Ciapała ◽  
Katarzyna Pawlik ◽  
Marco Oggioni ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Complement System ◽  
The Complement System

scholarly journals Post-Concussion Symptoms in Complicated vs. Uncomplicated Mild Traumatic Brain Injury Patients at Three and Six Months Post-Injury: Results from the CENTER-TBI Study

2019 ◽  
Vol 8 (11) ◽  
pp. 1921 ◽  
Author(s):  
Daphne C. Voormolen ◽  
Juanita A. Haagsma ◽  
Suzanne Polinder ◽  
Andrew I.R. Maas ◽  
Ewout W. Steyerberg ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Mild Traumatic Brain Injury ◽  
Odds Ratio ◽  
Post Injury ◽  
Chi Square ◽  
Time Points ◽  
Post Concussion Syndrome ◽  
Icd 10 ◽  
Baseline Covariates

The aim of this study was to assess the occurrence of post-concussion symptoms and post-concussion syndrome (PCS) in a large cohort of patients after complicated and uncomplicated mild traumatic brain injury (mTBI) at three and six months post-injury. Patients were included through the prospective cohort study: Collaborative European NeuroTrauma Effectiveness Research (CENTER-TBI). Patients enrolled with mTBI (Glasgow Coma Scale 13–15) were further differentiated into complicated and uncomplicated mTBI based on the presence or absence of computed tomography abnormalities, respectively. The Rivermead Post-Concussion Symptoms Questionnaire (RPQ) assessed post-concussion symptoms and PCS according to the mapped ICD-10 classification method. The occurrence of post-concussion symptoms and syndrome at both time points was calculated. Chi square tests were used to test for differences between and within groups. Logistic regression was performed to analyse the association between complicated versus uncomplicated mTBI and the prevalence of PCS. Patients after complicated mTBI reported slightly more post-concussion symptoms compared to those after uncomplicated mTBI. A higher percentage of patients after complicated mTBI were classified as having PCS at three (complicated: 46% vs. uncomplicated: 35%) and six months (complicated: 43% vs. uncomplicated 34%). After adjusting for baseline covariates, the effect of complicated versus uncomplicated mTBI at three months appeared minimal: odds ratio 1.25 (95% confidence interval: 0.95–1.66). Although patients after complicated mTBI report slightly more post-concussion symptoms and show higher PCS rates compared to those after uncomplicated mTBI at three and six months, complicated mTBI was only found a weak indicator for these problems.

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