Resuscitation with Valproic Acid Alters Inflammatory Genes in a Porcine Model of Combined Traumatic Brain Injury and Hemorrhagic Shock

Traumatic brain injury and hemorrhagic shock (TBI+HS) elicit a complex inflammatory response that contributes to secondary brain injury. There is currently no proven pharmacologic treatment for TBI+HS, but modulation of the epigenome has been shown to be a promising strategy. The aim of this study was to investigate whether valproic acid (VPA), a histone deacetylase inhibitor, modulates the expression of cerebral inflammatory gene profiles in a large animal model of TBI+HS. Ten Yorkshire swine were subjected to computer-controlled TBI+HS (40% blood volume). After 2?h of shock, animals were resuscitated with Hextend (HEX) or HEX+VPA (300?mg/kg, n?=?5/group). Six hours after resuscitation, brains were harvested, RNA was isolated, and gene expression profiles were measured using a porcine microarray. Ingenuity Pathway Analysis? (IPA), gene ontology (GO), Parametric Gene Set Enrichment Analysis (PGSEA), and DAVID (Database for Annotation, Visualization, and Integrated Discovery) were used for pathway analysis. Key microarray findings were verified using real-time polymerase chain reaction (PCR). IPA analysis revealed that VPA significantly down-regulated the complement system (p?Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140171/1/neu.2015.4163.pd

Interrelation between inflammation, thrombosis, and neuroprotection in cerebral ischemia

Stroke by mechanism of thrombotic cerebral ischemia is one of the leading causes of death and/or disability worldwide. Current research is under consensus that there are sex-based differences in both the prevalence and presentation of stroke and thrombosis. Here we discuss the interrelation between thrombosis and inflammation and call attention to points in the cerebral ischemic cascade where estrogen may be involved in neuroprotection. Cerebral ischemia triggers a series of events including inflammation, which is deeply interrelated with thrombosis; inflammation not only produces local thrombosis, but thrombosis can also amplify inflammation especially through the synergism of leukocyte and platelet activity. Research involving experimental animal models of cerebral ischemia has shown that sex hormones, especially estrogen, offer a degree of neuroprotection. Mechanisms of this neuroprotection may be linked to certain anti-inflammatory properties of estrogen, as well as estrogen ’ s regulation of thrombosis through the lowering of coagulation factors, among others. It is also understood that sex hormones alter the function and morphology of platelets and fibrin networks, and changes in platelet and fibrin network morphology offer one of the earliest confirmations of inflammation. Sex hormone levels, inflammatory processes, and thrombotic mechanisms are profoundly interconnected in predicting the outcome of cerebral ischemia.http://www.degruyter.comview/j/revneuroam2017AnatomyPhysiolog

Acute or delayed treatment with anatabine improves spatial memory and reduces pathological sequelae at late time-points after repetitive mild traumatic brain injury

Traumatic brain injury (TBI) has chronic and long-term consequences for which there are currently no approved pharmacological treatments. We have previously characterized the chronic neurobehavioral and pathological sequelae of a mouse model of repetitive mild TBI (r-mTBI) through to 2 years post-TBI. Despite the mild nature of the initial insult, secondary injury processes are initiated that involve neuroinflammatory and neurodegenerative pathways persisting and progressing for weeks and months post-injury and providing a potential window of opportunity for therapeutic intervention. In this study we examined the efficacy of a novel anti-inflammatory compound, anatabine, in modifying outcome after TBI. Our model of r-mTBI involves a series of five mild impacts (midline impact at 5 m/sec, 1 mm strike depth, 200 msec dwell time) with an interval of 48 h. Anatabine treatment was administered starting 30 min after injury and was delivered continuously through drinking water. At 6 months after TBI, anatabine treatment improved spatial memory in injured mice. Nine months after TBI, a cohort of mice was euthanized for pathological analysis that revealed reductions in astroglial (glial fibrillary acid protein, GFAP) and microglial (ionized calcium-binding adapter molecule 1, IBA1) responses in treated, injured animals. Treatments for the remaining mice were then crossed-over to assess the effects of late treatment administration and the effects of treatment termination. Nine months following crossover the remaining mice showed no effect of injury on their spatial memory, and whereas pathological analysis showed improvements in mice that had received delayed treatment, corpus callosum IBA1 increased in post-crossover placebo r-mTBI mice. These data demonstrate efficacy of both early and late initiation of treatment with anatabine in improving long term behavioral and pathology outcomes after mild TBI. Future studies will characterize the treatment window, the time course of treatment needed, and the dose needed to achieve therapeutic levels of anatabine in humans after injury

Studies on the mechanisms of the Beneficial effects of Herba Leonuri and Leonurine on Traumatic Brain Injury in Rat

Master'sMASTER OF SCIENC

Impact d'un traumatisme crânio-cérébral léger sur l’architecture du sommeil et le transcriptome dans un modèle murin

Le traumatisme crânien léger (TCL) est l'un des troubles neurologiques les plus courants affectant la santé publique. Aussi, les troubles du sommeil sont fréquents chez les patients atteints de TCL. Les études chez les rongeurs montrent que certains marqueurs de plasticité synaptique diminuent après le TCL, ce qui pourrait nuire à la plasticité du cerveau. Nous suggérons que la perte de sommeil intensifie l'effet négatif de TCL, qui peut refléter les changements des marqueurs de plasticité synaptique ou des changements des voies physiologiques qui régulent le sommeil. En utilisant un modèle de traumatisme crânien sur crâne fermé (closed head injury), nous avons étudié la relation bidirectionnelle entre le TCL et le sommeil en évaluant les effets de TCL sur l’activité électrique du cerveau par électroencéphalographie (EEG), et ceux de la privation de sommeil (PS) sur l'expression génique post-TCL. Premièrement, l'activité EEG a été enregistrée pour voir si l'architecture du sommeil est altérée suite au TCL. Nous avons ensuite voulu tester si la PS suite TCL induit des changements dans l'expression des gènes : Arc, Homer1a, Hif1a, Bdnf, Fos et éphrines, qui ont été liés à la plasticité synaptique et à la régulation du sommeil. Nous avons également étudié l'effet de la PS post-TCL sur le génome complet dans les régions cibles (cortex et l'hippocampe). Les principaux résultats obtenus dans cette étude confirment que TCL modifie de manière significative l'activité spectrale pendant l'éveil, le sommeil Rapid Eye Movement (REM) et le sommeil non-REM dans le deuxième 24 heures post-TCL. Fait intéressant, la capacité de maintenir de longues périodes d'éveil a été altérée immédiatement après TCL (première 24h post-TCL). La dynamique de l'activité delta pendant l'éveil a été modifié par le TCL. Parallèlement à ces modifications, des changements dans l'expression des gènes ont été observés dans le cortex et l'hippocampe. Seulement Arc et EfnA3 ont montré une interaction TCL / PS et ce dans l’hippocampe, tandis que l'expression de tous les autres gènes semblait être affectée par la PS ou TCL indépendamment. Nos résultats montrent pour la première fois que le TCL induit l'expression de deux chimiokines (Ccl3 et Cxcl5) à la fois dans le cortex cérébral et l'hippocampe 2,5 jours post-TCL. Également, nous avons observé que le TCL induit une diminution de l'expression de Lgals3 et S100A8 dans le cortex, et une augmentation d’Olig2 dans l'hippocampe. Les résultats concernant les effets de la PS sur le génome complet du cortex et de l'hippocampe montrent des changements significatifs dans les gènes impliqués dans diverses fonctions physiologiques, telles que les rythmes circadiens, la réponse inflammatoire, ainsi que de l'activation des cellules gliales. En général, nos résultats précisent les changements dans la qualité de l’éveil ainsi que dans l'expression de divers gènes après TCL.Mild traumatic brain injury (mTBI) is one of the most common neurological disorders affecting public health. Sleep disorders are common in patients with mTBI. Studies in rodents show that some synaptic plasticity markers decreased after mTBI which could impair brain plasticity. We suggest that sleep loss intensifies the negative effect of mTBI, which may reflect changes of synaptic plasticity markers or changes of different physiological pathway that regulates the sleep process. Using a "closed head injury" model, we have studied the bidirectional relationship between mTBI and sleep by investigating the effects of mTBI on sleep structure, and that of sleep deprivation (SD) on gene expression post-mTBI. First, EEG activity was monitored to investigate if sleep architecture is altered following mTBI. We then tested if SD, following mTBI, induces changes in gene expression of plasticity markers (Arc, Homer1a, Hif1a, Bdnf, Fos, and Ephrins), which have also been linked to sleep regulation. We also investigated the effect of SD post-mTBI on genome wide gene expression in target regions. The main results obtained in this study confirm that mTBI affects wakefulness, and significantly changes spectral activity during wakefulness, rapid eye movement (REM) sleep, and non-REM sleep on the second 24 hours post-TCL. Interestingly, the capacity to sustain long bouts of wakefulness was impaired immediately after mTBI. In addition, delta activity time course was altered by mTBI during wakefulness. In parallel to these alterations, changes in gene expression were observed. Only Arc and EfnA3 showed a mTBI/SD interaction in the hippocampus specifically, whereas expression of all other genes seemed to be affected by SD or mTBI independently. Our results indicate for the first time that the TCL induced the expression of two chemokines (Ccl3 and Cxcl5) in the cerebral cortex and hippocampus 2.5 days post-TCL. Also, we observed that the TCL induces a decrease in the expression of Lgals3 and S100A8 in the cortex, and an increase of Olig2 in the hippocampus.Results of SD effects on genome wide gene expression in the cortex and hippocampus show significant changes in genes involved in various physiological functions, such as circadian rhythms, inflammation, and also glial cell activation. In general, our results precise changes in wakefulness as well as in expression of various genes after mTBI

Fluid Percussion Injury in the Rat as an Animal Model of Concussion: Cumulative Effects of Repeated Concussion and its Treatment by Anti-CD11d Antibody

Traumatic brain injury is a global health concern with limited treatment options currently available. Concussion is the most common form of traumatic brain injury, and although a single concussion rarely results in long-term neurological dysfunction, repeated concussion can result in cumulative damage and chronic neurodegenerative disease. However, little is known about the factors and mechanisms of concussion involved in these detrimental effects. Animal models provide a means to examine the factors and mechanisms involved in traumatic brain injury, as well as potential treatments, in experiments that cannot be conducted using human participants. In the present thesis a fluid percussion model of traumatic brain injury was used to study single and repeated concussion in adult male Long-Evans rats. Anti-CD11d integrin antibody, a novel compound that reduces neuroinflammation by targeting the infiltration of peripheral leukocytes into the brain after traumatic brain injury, was evaluated as a potential treatment for concussion. In Study 1 a single mild lateral fluid percussion injury (1.0-1.5 atm) caused short-term (24 hrs) behavioral impairments and neuropathological alterations indicative of neuroinflammation and axonal injury. In Study 2, three or five mild lateral fluid percussion injuries given at 5-day intervals caused cumulative short-term (24 hrs) and long-term (8 weeks) behavioral impairments and neuropathological alterations indicative of neuroinflammation and cortical loss. These results appear to validate the use of single and repeated mild lateral fluid percussion injuries to model important aspects of human concussion. In Study 3 anti-CD11d antibody administered after a single moderate lateral fluid percussion injury (2.5 - 3.0 atm) reduced cognitive, emotional, and motor impairments, and also reduced neuroinflammation and neuronal loss relative to injured rats treated with a control antibody. In Study 4 anti-CD11d antibody administered after each of three repeated mild lateral fluid percussion injuries similarly reduced cognitive, emotional, and motor impairments, and neuroinflammation and cortical loss relative to injured rats treated with a control antibody. These novel findings suggest the involvement of infiltrating peripheral leukocytes and neuroinflammation in both single and repeated concussion, and they support the further investigation of anti-CD11d antibody as a potential treatment for concussion

Acute or Delayed Treatment with Anatabine Improves Spatial Memory and Reduces Pathological Sequelae at Late Time-Points after Repetitive Mild Traumatic Brain Injury

Traumatic brain injury (TBI) has chronic and long-term consequences for which there are currently no approved pharmacological treatments. We have previously characterized the chronic neurobehavioral and pathological sequelae of a mouse model of repetitive mild TBI (r-mTBI) through to 2 years post-TBI. Despite the mild nature of the initial insult, secondary injury processes are initiated that involve neuroinflammatory and neurodegenerative pathways persisting and progressing for weeks and months post-injury and providing a potential window of opportunity for therapeutic intervention. In this study we examined the efficacy of a novel anti-inflammatory compound, anatabine, in modifying outcome after TBI. Our model of r-mTBI involves a series of five mild impacts (midline impact at 5 m/sec, 1 mm strike depth, 200 msec dwell time) with an interval of 48 h. Anatabine treatment was administered starting 30 min after injury and was delivered continuously through drinking water. At 6 months after TBI, anatabine treatment improved spatial memory in injured mice. Nine months after TBI, a cohort of mice was euthanized for pathological analysis that revealed reductions in astroglial (glial fibrillary acid protein, GFAP) and microglial (ionized calcium-binding adapter molecule 1, IBA1) responses in treated, injured animals. Treatments for the remaining mice were then crossed-over to assess the effects of late treatment administration and the effects of treatment termination. Nine months following crossover the remaining mice showed no effect of injury on their spatial memory, and whereas pathological analysis showed improvements in mice that had received delayed treatment, corpus callosum IBA1 increased in post-crossover placebo r-mTBI mice. These data demonstrate efficacy of both early and late initiation of treatment with anatabine in improving long term behavioral and pathology outcomes after mild TBI. Future studies will characterize the treatment window, the time course of treatment needed, and the dose needed to achieve therapeutic levels of anatabine in humans after injury

Alterations in the cerebrospinal fluid relating to apolipoprotein E after traumatic brain injury and subarachnoid haemorrhage.

Background: The human gene coding for apolipoprotein E is polymorphic, and the APOE4 allele has been associated with less favourable outcome after acute brain injury including traumatic brain injury (TBI) and subarachnoid haemorrhage (SAH). Experimental studies identify key roles for apoE in the central nervous system such as the scavenging and recycling of lipids for cellular maintenance and repair and formation of cerebral amyloid aggregate. Human in-vivo evidence supporting the concept that apoE is involved in the response of the brain to acute injury is sparse. Objectives: This study tests the hypothesis that apoE is involved in the response of the human brain to injury, and this role is reflected by changes in cerebrospinal fluid (CSF) apoE concentration after brain injury which correlate with injury severity and outcome. In addition it was hypothesised that changes in apoE concentration would be paralleled by changes in the composition of CSF lipoprotein particles (Lps) of which apoE is a major component. Lastly, apoE is reported to chaperone amyloid-beta peptide (Abeta), therefore we hypothesised that alteration in CSF apoE after brain injury would parallel alterations in Abeta. Methods: Enzyme linked immunosorbant assay (ELISA) was used to determine the concentration of apoE, Abeta, S100B and Tau (as surrogate markers of brain injury) in CSF from TBI and SAH patients and a non-brain injured control group. Lipoprotein particles were isolated from CSF using size exclusion chromatography and characterised in relation to cholesterol, phospholipid, apolipoprotein E, and apohpoprotein AI composition. Injury severity was determined using the Glasgow Coma Score, and clinical outcome using the Glasgow Outcome Score. Results: Compared to controls there was a sustained decrease in the concentration of apoE in the CSF after TBI and SAH which was paralleled by a depletion of apoE containing lipoprotein particles. Furthermore, CSF Abeta also decreased, and the decrease correlated with injury severity and clinical outcome. In contrast the levels of S100B and Tau in brain injury CSF was substantially elevated. Conclusion: Despite the likely leakage of plasma apolipoprotein E into the subarachnoid space at the time of brain injury, apoE in the form of LpE is cleared from the CSF within days of injury. In addition, indirect evidence suggesting apoE-Abeta interactions in-vivo support the concept that apoE may form insoluble aggregates with Abeta soon after brain injury. The finding that these alterations in the CSF correlate with injury severity and outcome provides novel indirect in-vivo evidence that apoE is important to the response of the human brain to injury

Cytokines and Myelination in the Central Nervous System

Myelin abnormalities that reflect damage to developing and mature brains are often found in neurological diseases with evidence of inflammatory infiltration and microglial activation. Many cytokines are virtually undetectable in the uninflamed central nervous system (CNS), so that their rapid induction and sustained elevation in immune and glial cells contributes to dysregulation of the inflammatory response and neural cell homeostasis. This results in aberrant neural cell development, cytotoxicity, and loss of the primary myelin-producing cells of the CNS, the oligodendrocytes. This article provides an overview of cytokine and chemokine activity in the CNS with relevance to clinical conditions of neonatal and adult demyelinating disease, brain trauma, and mental disorders with observed white matter defects. Experimental models that mimic human disease have been developed in order to study pathogenic and therapeutic mechanisms, but have shown mixed success in clinical application. However, genetically altered animals, and models of CNS inflammation and demyelination, have offered great insight into the complexities of neuroimmune interactions that impact oligodendrocyte function. The intracellular signaling pathways of selected cytokines have also been highlighted to illustrate current knowledge of receptor-mediated events. By learning to interpret the actions of cytokines and by improving methods to target appropriate predictors of disease risk selectively, a more comprehensive understanding of altered immunoregulation will aid in the development of advanced treatment options for patients with inflammatory white matter disorders

Papel do receptor B2 para as cininas na neuroinflamação induzida pelo peptídeo beta-amilóide

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas. Programa de Pós-Graduação em Farmacologia.O objetivo do presente estudo foi investigar o papel do receptor B2 para as cininas na neuroinflamação induzida pelo peptídeo A?1-40 em camundongos. Há indícios de que o peptídeo A? tem um papel central na doença de Alzheimer e, de relevância para este trabalho, estudos recentes sugeriram o envolvimento do sistema calicreína-cininas na patofisiologia da doença em humanos, bem como sua contribuição em modelos experimentais desta doença. Para a realização dos experimentos, os animais foram pré-tratados com o antagonista seletivo do receptor B2, o HOE 140 (50 ?mol/sítio/ i.c.v.), 2 horas antes da injeção i.c.v do peptídeo A?1-40 (400 ?mol/sítio). Após 14 dias, os animais foram submetidos aos testes comportamentais e no dia seguinte (dia 15), os cérebros foram removidos para a realização da técnica de western blot. Ainda, o mesmo protocolo de tratamento foi seguido para a realização de coletas em tempos específicos (6h, 24h ou 8 dias) para a realização das análises de imunoistoquímica, nos tempos de expressão máximo da cada proteína. O pré-tratamento dos animais com HOE 140 preveniu o prejuízo cognitivo e o dano sinápico induzido pelo peptídeo A?1-40, avaliados através do teste de reconhecimento de objetos e pela expressão das proteínas sinápticas sinaptofisina e PSD-95, respectivamente. Além disso, o peptídeo A?1-40 induziu aumento na expressão do receptor B2 após 15 dias no hipocampo dos animais, e o bloqueio deste receptor com o HOE 140 preveniu esta alteração, sugerindo uma possível auto-regulação do receptor B2 pelo seu antagonista. Ainda, o processo inflamatório induzido pelo peptídeo A?1-40, evidenciado através do aumento da ativação microglial e do aumento na expressão das enzimas COX-2, iNOS e nNOS, foi prevenido pelo pré-tratamento com o HOE 140. Estes efeitos tóxicos iniciados pela administração de A?1-40 parecem ser mediados pela ativação de PKC (isoformas ? e ?) e, por conseguinte, das MAPKs p-38 e JNK, e dos fatores de transcrição NF?B e c-jun. Estes eventos parecem ser modulados pela ativação do receptor B2, uma vez que, o bloqueio deste receptor com o HOE 140 preveniu todas estas alterações induzidas pelo peptídeo A?1-40. Estes resultados, analisados em conjunto, fornecem evidências de que a toxicidade induzida por A?1-40 parece ser mediada pela ativação do receptor B2 e que o bloqueio deste receptor e das vias de sinalização por ele ativadas podem ser novos alvos para o tratamento do processo inflamatório característico na progressão da doença de Alzheimer.The aim of this study was to investigate the role of the kinin B2 receptor in the A?-induced neuroinflammation in mice. There are recent evidences showing that the A? peptide has a central role in Alzheimer's disease. Relevantly, recent studies have suggested the involvement of the kallikrein-kinin system in the pathophysiology of Alzheimer's disease in both humans and experimental models. In this study, experimental procedures were carried out using Swiss mice pretreated with the selective B2 receptor antagonist, HOE 140 (50 ?mol/site, i.c.v.), given two hours prior the i.c.v. injection of A?1-40 peptide (400 ?mol/site). After 14 days, the animals were subjected to behavioral tests, and on day 15 the brains were removed to perform Western blot analysis. In addition, the same treatment protocol was used to carry out tissue collections, at specific time points (6h, 24h or 8 days), in order to perform immunohistochemical analysis. These time point were chosen based on the maximum expression level of each protein. The pretreatment of animals with HOE 140 prevented the cognitive impairment and synaptic injury induced by A?1-40 peptide, assessed using object recognition task and through evaluation of the expression of synaptic proteins, (synaptophysin and PSD-95), respectively. Furthermore, A?1-40 peptide increased B2 receptor expression, in the mice hippocampus after 15 days, and the pharmacological blockage of this receptor (with HOE 140) prevented this alteration, suggesting a possible auto-regulation mechanism for B2 receptor expression. Also, the A?1-40-induced inflammatory process was evidenced by increased microglial activation and increased expression of COX-2, iNOS and nNOS. All these alterations were prevented by the pretreatment with HOE 140. The toxic effects induced by A?1-40 administration seems to be mediated by activation of PKC (? and ? isoforms), which leads to the activation of p-38 MAPKs and JNK, and transcription factors NF?B and c-Jun. These events seems to be modulated by activation of B2 receptor, since blocking this receptor with HOE 140 prevented all these changes. These results, taken together, provide evidence that the A?-induced toxicity might be mediated by B2 receptor activation. Thus, the blockage of B2 receptor, and signaling pathways activated by it, might constitute new attractive targets for the treatment of the inflammation associated with of Alzheimer's disease progression