RESUMO
Traumatic brain injury (TBI) is an acquired insult to the brain caused by an external mechanical force, potentially resulting in temporary or permanent impairment. Microglia, the resident immune cells of the central nervous system, are activated in response to TBI, participating in tissue repair process. However, the underlying epigenetic mechanisms in microglia during TBI remain poorly understood. ARID1A (AT-Rich Interaction Domain 1 A), a pivotal subunit of the multi-protein SWI/SNF chromatin remodeling complex, has received little attention in microglia, especially in the context of brain injury. In this study, we generated a Arid1a cKO mouse line to investigate the potential roles of ARID1A in microglia in response to TBI. We found that glial scar formation was exacerbated due to increased microglial migration and a heightened inflammatory response in Arid1a cKO mice following TBI. Mechanistically, loss of ARID1A led to an up-regulation of the chemokine CCL5 in microglia upon the injury, while the CCL5-neutralizing antibody reduced migration and inflammatory response of LPS-stimulated Arid1a cKO microglia. Importantly, administration of auraptene (AUR), an inhibitor of CCL5, repressed the microglial migration and inflammatory response, as well as the glial scar formation after TBI. These findings suggest that ARID1A is critical for microglial response to injury and that AUR has a therapeutic potential for the treatment of TBI.
Assuntos
Lesões Encefálicas Traumáticas , Quimiocina CCL5 , Proteínas de Ligação a DNA , Camundongos Knockout , Microglia , Fatores de Transcrição , Animais , Lesões Encefálicas Traumáticas/patologia , Lesões Encefálicas Traumáticas/metabolismo , Lesões Encefálicas Traumáticas/genética , Microglia/metabolismo , Microglia/patologia , Quimiocina CCL5/metabolismo , Quimiocina CCL5/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Camundongos , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Movimento Celular , Cicatriz/patologia , Cicatriz/metabolismo , Camundongos Endogâmicos C57BL , MasculinoRESUMO
BACKGROUND: The burgeoning field of regenerative medicine has significantly advanced with recent findings on biotherapies using human platelet lysates (HPLs), derived from clinical-grade platelet concentrates (PCs), for treating brain disorders. These developments have opened new translational research avenues to explore the neuroprotective effects of platelet-extracellular vesicles (PEVs). Their potential in managing neurodegenerative conditions like traumatic brain injury (TBI) and Parkinson's disease (PD) warrants further exploration. We aimed here to characterize the composition of a PEV preparation isolated from platelet concentrate (PC) supernatant, and determine its neuroprotective potential and neurorestorative effects in cellular and animal models of TBI and PD. METHODS: We isolated PEVs from the supernatant of clinical-grade PC collected from healthy blood donors utilizing high-speed centrifugation. PEVs were characterized by biophysical, biochemical, microscopic, and LC-MS/MS proteomics methods to unveil biological functions. Their functionality was assessed in vitro using SH-SY5Y neuronal cells, LUHMES dopaminergic neurons, and BV-2 microglial cells, and in vivo by intranasal administration in a controlled cortical impact (CCI)-TBI model using 8-weeks-old male C57/BL6 mice, and in a PD model induced by MPTP in 5-month-old male C57/BL6 mice. RESULTS: PEVs varied in size from 50 to 350 nm, predominantly around 200 nm, with concentrations ranging between 1010 and 1011/mL. They expressed specific platelet membrane markers, exhibited a lipid bilayer by cryo-electron microscopy and, importantly, showed low expression of pro-coagulant phosphatidylserine. LC-MS/MS indicated a rich composition of trophic factors, including neurotrophins, anti-inflammatory agents, neurotransmitters, and antioxidants, unveiling their multifaceted biological functions. PEVs aided in the restoration of neuronal functions in SH-SY5Y cells and demonstrated remarkable neuroprotective capabilities against erastin-induced ferroptosis in dopaminergic neurons. In microglial cells, they promoted anti-inflammatory responses, particularly under inflammatory conditions. In vivo, intranasally delivered PEVs showed strong anti-inflammatory effects in a TBI mouse model and conserved tyrosine hydroxylase expression of dopaminergic neurons of the substantia nigra in a PD model, leading to improved motor function. CONCLUSIONS: The potential of PEV-based therapies in neuroprotection opens new therapeutic avenues for neurodegenerative disorders. The study advocates for clinical trials to establish the efficacy of PEV-based biotherapies in neuroregenerative medicine.
Assuntos
Plaquetas , Lesões Encefálicas Traumáticas , Vesículas Extracelulares , Camundongos Endogâmicos C57BL , Fármacos Neuroprotetores , Doença de Parkinson , Vesículas Extracelulares/metabolismo , Animais , Humanos , Lesões Encefálicas Traumáticas/metabolismo , Camundongos , Plaquetas/metabolismo , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/administração & dosagem , Masculino , Doença de Parkinson/terapia , Administração Intranasal , Modelos Animais de DoençasRESUMO
Traumatic brain injury (TBI) results from sudden accidents, leading to brain damage, subsequent organ dysfunction, and potentially death. Despite extensive studies on rodent TBI models, there is still high variability in terms of target points, and this results in significantly different symptoms between models. In this study, we established a more concise and effective TBI mouse model, which included locomotor dysfunctions with increased apoptosis, based on the controlled cortical impact method. Behavioral tests, such as elevated body swing, rotarod, and cylinder tests were performed to assess the validity of our model. To investigate the underlying mechanisms of injury, we analyzed the expression of proteins associated with immune response and the apoptosis signaling pathway via western blotting analysis and immunohistochemistry. Upon TBI induction, the mouse subjects showed motor dysfunctions and asymmetric behavioral assessment. The expression of Bax gradually increased over time and reached its maximum 3 days post-surgery, and then declined. The expression of Mcl-1 showed a similar trend to Bax. Furthermore, the expression of caspase-3, ROCK1, and p53 were highly elevated by 3 days post-surgery and then declined by 7 days post-surgery. Importantly, immunohistochemistry revealed an immediate increase in the level of Bcl-2 at the lesion site upon TBI induction. Also, we found that the expression of neuronal markers, such as NeuN and MAP2, decreased after the surgery. Interestingly, the increase in NFH level was in line with the symptoms of TBI in humans. Collectively, our study demonstrated that the established TBI model induces motor dysfunction, hemorrhaging, infarctions, and apoptosis, closely resembling TBI in humans. Therefore, we predict that our model may be useful for developing effective treatment option for TBI.
Assuntos
Lesões Encefálicas Traumáticas , Modelos Animais de Doenças , Animais , Lesões Encefálicas Traumáticas/patologia , Lesões Encefálicas Traumáticas/metabolismo , Lesões Encefálicas Traumáticas/fisiopatologia , Camundongos , Masculino , Apoptose , Fatores de Tempo , Camundongos Endogâmicos C57BL , Atividade MotoraRESUMO
Objective: Critically ill patients, including those with brain injuries (BI), are frequently hospitalized in an intensive care unit (ICU). As with other critical states, an adequate stress response is essential for survival. Research on the hypothalamic-pituitary-adrenal gland (HPA) axis function in BI has primarily focused on assessing ACTH and cortisol levels. However, the immunological, metabolic, and hemodynamic effects of glucocorticoids (GCs) are mediated through the glucocorticoid receptor (GCR), a ubiquitously distributed intracellular receptor protein. Data on GCR-α expression and its signaling in acute BI injury are lacking. Methods: We designed a prospective observational study, carried out in one academic multi-disciplinary ICU. Forty-two critically ill patients with acute (BI)were included. These patients suffered from traumatic BI (N= 20), subarachnoid hemorrhage (N= 12), intracranial hemorrhage (N= 7), or ischemic stroke (N= 3). All patients were steroid-free. Twenty-four age and sex-matched healthy controls were used for comparison. Results: Expression of GCR-α and the glucocorticoid-inducible leucine zipper (GILZ), serum cortisol, interleukins (IL) 6, 8, 10 and TNF- α, and the BI biomarkers glial fibrillary acidic protein (GFAP) and total Tau were measured on ICU admission (within 48 hours) and 5-7 days from admission. Compared to healthy controls, in the critically ill patients with BI, GCR-α mRNA expression was significantly downregulated on admission, and after 5-7 days in the ICU (2.3-fold, p<0.05 and 2.6-fold, p<0.01, respectively). Even though GCR-α was downregulated, its downstream gene, GILZ, was expressed at the same levels as in normal controls on admission and was significantly upregulated 5-7 days following admission (2-fold, p<0.001). TNF-α levels were undetectable at both time-points. GCR-α expression levels inversely correlated with IL-6. The levels of cortisol and the BI biomarkers did not differ between the 2 time-points. Conclusions: We provide novel evidence on the downregulated expression and upregulated signaling of the ligand-binding and functionally active GCR-α isoform in the polymorphonuclear neutrophils (PMNs) of critically ill patients with BI. The increased GILZ expression indicates an increased GC sensitivity in the PMNs of BI critically ill patients.
Assuntos
Lesões Encefálicas , Estado Terminal , Neutrófilos , Receptores de Glucocorticoides , Humanos , Receptores de Glucocorticoides/metabolismo , Masculino , Feminino , Pessoa de Meia-Idade , Estudos Prospectivos , Neutrófilos/metabolismo , Adulto , Lesões Encefálicas/metabolismo , Lesões Encefálicas/sangue , Idoso , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Hidrocortisona/sangue , Hidrocortisona/metabolismo , Glucocorticoides , Lesões Encefálicas Traumáticas/metabolismo , Zíper de LeucinaRESUMO
Mitochondria provide the energy to keep cells alive and functioning and they have the capacity to influence highly complex molecular events. Mitochondria are essential to maintain cellular energy homeostasis that determines the course of neurological disorders, including traumatic brain injury (TBI). Various aspects of mitochondria metabolism such as autophagy can have long-term consequences for brain function and plasticity. In turn, mitochondria bioenergetics can impinge on molecular events associated with epigenetic modifications of DNA, which can extend cellular memory for a long time. Mitochondrial dysfunction leads to pathological manifestations such as oxidative stress, inflammation, and calcium imbalance that threaten brain plasticity and function. Hence, targeting mitochondrial function may have great potential to lessen the outcomes of TBI.
Assuntos
Lesões Encefálicas Traumáticas , Encéfalo , Metabolismo Energético , Mitocôndrias , Plasticidade Neuronal , Lesões Encefálicas Traumáticas/metabolismo , Lesões Encefálicas Traumáticas/fisiopatologia , Humanos , Animais , Mitocôndrias/metabolismo , Encéfalo/metabolismo , Encéfalo/fisiopatologia , Encéfalo/patologia , Estresse OxidativoRESUMO
Traumatic brain injury (TBI) affects millions globally, with a majority of TBI cases being classified as mild, in which diffuse pathologies prevail. Two of the pathological hallmarks of TBI are diffuse axonal injury (DAI) and microglial activation. While progress has been made investigating the breadth of TBI-induced axonal injury and microglial changes in rodents, the neuroinflammatory progression and interaction between microglia and injured axons in humans is less well understood. Our group previously investigated microglial process convergence (MPC), in which processes of non-phagocytic microglia directly contact injured proximal axonal swellings, in rats and micropigs acutely following TBI. These studies demonstrated that MPC occurred on injured axons in the micropig, but not in the rat, following diffuse TBI. While it has been shown that microglia co-exist and interact with injured axons in humans post-TBI, the occurrence of MPC has not been quantitatively measured in the human brain. Therefore, in the current study we sought to validate our pig findings in human postmortem tissue. We investigated MPC onto injured axonal swellings and intact myelinated fibers in cases from individuals with confirmed DAI and control human brain tissue using multiplex immunofluorescent histochemistry. We found an increase in MPC onto injured axonal swellings, consistent with our previous findings in micropigs, indicating that MPC is a clinically relevant phenomenon that warrants further investigation.
Assuntos
Axônios , Lesão Axonal Difusa , Microglia , Humanos , Microglia/patologia , Microglia/metabolismo , Axônios/patologia , Axônios/metabolismo , Animais , Masculino , Suínos , Lesão Axonal Difusa/patologia , Lesão Axonal Difusa/metabolismo , Feminino , Encéfalo/patologia , Encéfalo/metabolismo , Lesões Encefálicas Traumáticas/patologia , Lesões Encefálicas Traumáticas/metabolismo , Pessoa de Meia-Idade , Autopsia , Adulto , Idoso , RatosRESUMO
OBJECTIVE: Traumatic brain injury (TBI)-induced anxiety is a common but under-investigated disorder, for which neuroinflammation is a significant contributor. Here we aim to investigate the protective effects of genistein, a plant-derived anti-inflammatory drug, against TBI-induced anxiety, and the underlying mechanisms. METHODS: A rat model of TBI was constructed using the lateral fluid percussion injury method. Genistein at the doses of 5, 10, and 20 mg/kg were used to treat rats at 30 min, 12 h, 24 h, 48 h, and 72 h up to 14 days after TBI. The evaluation of neurological deficit was performed preoperatively, on days 1, 3, 7, and 14 after TBI. The elevated plus maze test was carried out to assess anxiety and explorative behaviours, and the open field test was performed to assess locomotive activities. Brain injury was assessed by measuring brain water content and TdT-mediated dUTP Nick-End Labeling staining. Inflammatory responses were examined using enzyme-linked immunosorbent assay. The mRNA and protein expression were analysed using real-time polymerase chain reaction and Western blot, respectively. RESULTS: In the behavioural level, genistein treatment alleviated TBI-induced anxiety behaviours and neurological deficit in rats. In the meanwhile, brain oedema was also reduced by genistein treatment, showing alleviating effects of genistein at the pathological level. TUNEL staining also showed reduced apoptosis in rats treated with genistein. Genistein also inhibited Nlrp3/caspase-1 signalling, unveiling the effects of genistein in altering molecular pathways in brains with TBI. CONCLUSION: Genistein alleviates anxiety-like behaviours in TBI rats, which may be mediated via inhibiting Nlrp/caspase-1 signalling pathway.
Assuntos
Ansiedade , Lesões Encefálicas Traumáticas , Caspase 1 , Genisteína , Proteína 3 que Contém Domínio de Pirina da Família NLR , Ratos Sprague-Dawley , Transdução de Sinais , Animais , Genisteína/farmacologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Lesões Encefálicas Traumáticas/tratamento farmacológico , Lesões Encefálicas Traumáticas/complicações , Lesões Encefálicas Traumáticas/metabolismo , Lesões Encefálicas Traumáticas/psicologia , Caspase 1/metabolismo , Caspase 1/efeitos dos fármacos , Ratos , Masculino , Ansiedade/tratamento farmacológico , Ansiedade/etiologia , Transdução de Sinais/efeitos dos fármacos , Modelos Animais de Doenças , Comportamento Animal/efeitos dos fármacosRESUMO
Progression of acute traumatic brain injury (TBI) into chronic neurodegeneration is a major health problem with no protective treatments. Here, we report that acutely elevated mitochondrial fission after TBI in mice triggers chronic neurodegeneration persisting 17 months later, equivalent to many human decades. We show that increased mitochondrial fission after mouse TBI is related to increased brain levels of mitochondrial fission 1 protein (Fis1) and that brain Fis1 is also elevated in human TBI. Pharmacologically preventing Fis1 from binding its mitochondrial partner, dynamin-related protein 1 (Drp1), for 2 weeks after TBI normalizes the balance of mitochondrial fission/fusion and prevents chronically impaired mitochondrial bioenergetics, oxidative damage, microglial activation and lipid droplet formation, blood-brain barrier deterioration, neurodegeneration, and cognitive impairment. Delaying treatment until 8 months after TBI offers no protection. Thus, time-sensitive inhibition of acutely elevated mitochondrial fission may represent a strategy to protect human TBI patients from chronic neurodegeneration.
Assuntos
Lesões Encefálicas Traumáticas , Dinaminas , Mitocôndrias , Dinâmica Mitocondrial , Proteínas Mitocondriais , Lesões Encefálicas Traumáticas/metabolismo , Lesões Encefálicas Traumáticas/patologia , Animais , Dinaminas/metabolismo , Dinaminas/genética , Proteínas Mitocondriais/metabolismo , Proteínas Mitocondriais/genética , Humanos , Camundongos , Mitocôndrias/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/patologia , Estresse Oxidativo , Encéfalo/patologia , Encéfalo/metabolismo , Microglia/metabolismo , Microglia/patologia , Doença Crônica , Modelos Animais de Doenças , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/patologiaRESUMO
BACKGROUND: Traumatic brain injury (TBI) causes axon tearing and synapse degradation, resulting in multiple neurological dysfunctions and exacerbation of early neurodegeneration; the repair of axonal and synaptic structures is critical for restoring neuronal function. C-C Motif Chemokine Ligand 5 (CCL5) shows many neuroprotective activities. METHOD: A close-head weight-drop system was used to induce mild brain trauma in C57BL/6 (wild-type, WT) and CCL5 knockout (CCL5-KO) mice. The mNSS score, rotarod, beam walking, and sticker removal tests were used to assay neurological function after mTBI in different groups of mice. The restoration of motor and sensory functions was impaired in CCL5-KO mice after one month of injury, with swelling of axons and synapses from Golgi staining and reduced synaptic proteins-synaptophysin and PSD95. Administration of recombinant CCL5 (Pre-treatment: 300 pg/g once before injury; or post-treatment: 30 pg/g every 2 days, since 3 days after injury for 1 month) through intranasal delivery into mouse brain improved the motor and sensory neurological dysfunctions in CCL5-KO TBI mice. RESULTS: Proteomic analysis using LC-MS/MS identified that the "Nervous system development and function"-related proteins, including axonogenesis, synaptogenesis, and myelination signaling pathways, were reduced in injured cortex of CCL5-KO mice; both pre-treatment and post-treatment with CCL5 augmented those pathways. Immunostaining and western blot analysis confirmed axonogenesis and synaptogenesis related Semaphorin, Ephrin, p70S6/mTOR signaling, and myelination-related Neuregulin/ErbB and FGF/FAK signaling pathways were up-regulated in the cortical tissue by CCL5 after brain injury. We also noticed cortex redevelopment after long-term administration of CCL5 after brain injury with increased Reelin positive Cajal-Rerzius Cells and CXCR4 expression. CCL5 enhanced the growth of cone filopodia in a primary neuron culture system; blocking CCL5's receptor CCR5 by Maraviroc reduced the intensity of filopodia in growth cone and also CCL5 mediated mTOR and Rho signalling activation. Inhibiting mTOR and Rho signaling abolished CCL5 induced growth cone formation. CONCLUSIONS: CCL5 plays a critical role in starting the intrinsic neuronal regeneration system following TBI, which includes growth cone formation, axonogenesis and synaptogensis, remyelination, and the subsequent proper wiring of cortical circuits. Our study underscores the potential of CCL5 as a robust therapeutic stratagem in treating axonal injury and degeneration during the chronic phase after mild brain injury.
Assuntos
Axônios , Quimiocina CCL5 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Animais , Camundongos , Quimiocina CCL5/metabolismo , Axônios/metabolismo , Axônios/fisiologia , Lesões Encefálicas Traumáticas/metabolismo , Lesões Encefálicas Traumáticas/fisiopatologia , Masculino , Neurônios/metabolismo , Lesões Encefálicas/metabolismo , NeurogêneseRESUMO
Neurotrauma plays a significant role in secondary injuries by intensifying the neuroinflammatory response in the brain. High Mobility Group Box-1 (HMGB1) protein is a crucial neuroinflammatory mediator involved in this process. Numerous studies have hypothesized about the underlying pathophysiology of HMGB1 and its role in cognition, but a definitive link has yet to be established. Elevated levels of HMGB1 in the hippocampus and serum have been associated with declines in cognitive performance, particularly in spatial memory and learning. This review also found that inhibiting HMGB1 can improve cognitive deficits following neurotrauma. Interestingly, HMGB1 levels are linked to the modulation of neuroplasticity and may offer neuroprotective effects in the later stages of neurotraumatic events. Consequently, administering HMGB1 during the acute phase may help reduce neuroinflammatory effects that lead to cognitive deficits in the later stages of neurotrauma. However, further research is needed to understand the time-dependent regulation of HMGB1 and the clinical implications of treatments targeting HMGB1 after neurotrauma.
Assuntos
Disfunção Cognitiva , Proteína HMGB1 , Proteína HMGB1/metabolismo , Proteína HMGB1/antagonistas & inibidores , Humanos , Animais , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/fisiopatologia , Lesões Encefálicas Traumáticas/complicações , Lesões Encefálicas Traumáticas/metabolismo , Lesões Encefálicas Traumáticas/tratamento farmacológico , Lesões Encefálicas Traumáticas/fisiopatologia , Terapia de Alvo Molecular/métodos , Hipocampo/metabolismo , Plasticidade Neuronal/efeitos dos fármacosRESUMO
Traumatic brain injury (TBI) has been found to be associated with certain peripheral organ injuries; however, a few studies have explored the chronological influences of TBI on multiple organs and the systemic effects of therapeutic interventions. Particularly, high-mobility group box 1 (HMGB1) is a potential therapeutic target for TBI; however, its effects on peripheral organs remain unclear. Therefore, this study aimed to determine whether severe TBI can lead to multiple organ injury and how HMGB1 inhibition affects peripheral organs. This study used a weight drop-induced TBI mouse model and found that severe TBI can trigger short-lived systemic inflammation, in the lungs and liver, but not in the kidneys, regardless of the severity of the injury. TBI led to an increase in circulating HMGB1 and enhanced gene expressions of its receptors in every organ. Anti-HMGB1 antibody treatment reduced neuroinflammation but increased inflammation in peripheral organs. This study also found that HMGB1 inhibition appears to have a beneficial role in early neuroinflammation but could lead to detrimental effects on peripheral organs through decreased peripheral immune suppression. This study provides novel insights into the chronological changes in multiple organs due to TBI and the unique roles of HMGB1 between the brain and other organs.
Assuntos
Lesões Encefálicas Traumáticas , Modelos Animais de Doenças , Proteína HMGB1 , Proteína HMGB1/metabolismo , Animais , Lesões Encefálicas Traumáticas/metabolismo , Lesões Encefálicas Traumáticas/patologia , Camundongos , Masculino , Camundongos Endogâmicos C57BL , Rim/metabolismo , Rim/patologia , Fígado/metabolismo , Fígado/patologia , Fígado/lesões , Inflamação/metabolismo , Pulmão/patologia , Pulmão/metabolismoRESUMO
Traumatic brain injury (TBI) is the leading cause of traumatic death worldwide and is a public health problem associated with high mortality and morbidity rates, with a significant socioeconomic burden. The diagnosis of brain injury may be difficult in some cases or may leave diagnostic doubts, especially in mild trauma with insignificant pathological brain changes or in cases where instrumental tests are negative. Therefore, in recent years, an important area of research has been directed towards the study of new biomarkers, such as micro-RNAs (miRNAs), which can assist clinicians in the diagnosis, staging, and prognostic evaluation of TBI, as well as forensic pathologists in the assessment of TBI and in the estimation of additional relevant data, such as survival time. The aim of this study is to investigate the expression profiles (down- and upregulation) of a panel of miRNAs in subjects deceased with TBI in order to assess, verify, and define the role played by non-coding RNA molecules in the different pathophysiological mechanisms of brain damage. This study also aims to correlate the detected expression profiles with survival time, defined as the time elapsed between the traumatic event and death, and with the severity of the trauma. This study was conducted on 40 cases of subjects deceased with TBI (study group) and 10 cases of subjects deceased suddenly from non-traumatic causes (control group). The study group was stratified according to the survival time and the severity of the trauma. The selection of miRNAs to be examined was based on a thorough literature review. Analyses were performed on formalin-fixed, paraffin-embedded (FFPE) brain tissue samples, with a first step of total RNA extraction and a second step of quantification of the selected miRNAs of interest. This study showed higher expression levels in cases compared to controls for miR-16, miR-21, miR-130a, and miR-155. In contrast, lower expression levels were found in cases compared to controls for miR-23a-3p. There were no statistically significant differences in the expression levels between cases and controls for miR-19a. In cases with short survival, the expression levels of miR-16-5p and miR-21-5p were significantly higher. In cases with long survival, miR-21-5p was significantly lower. The expression levels of miR-130a were significantly higher in TBI cases with short and middle survival. In relation to TBI severity, miR-16-5p and miR-21-5p expression levels were significantly higher in the critical-fatal TBI subgroup. Conclusions: This study provides evidence for the potential of the investigated miRNAs as predictive biomarkers to discriminate between TBI cases and controls. These miRNAs could improve the postmortem diagnosis of TBI and also offer the possibility to define the survival time and the severity of the trauma. The analysis of miRNAs could become a key tool in forensic investigations, providing more precise and detailed information on the nature and extent of TBI and helping to define the circumstances of death.
Assuntos
Lesões Encefálicas Traumáticas , MicroRNAs , Humanos , Lesões Encefálicas Traumáticas/genética , Lesões Encefálicas Traumáticas/mortalidade , Lesões Encefálicas Traumáticas/metabolismo , Lesões Encefálicas Traumáticas/patologia , Lesões Encefálicas Traumáticas/diagnóstico , MicroRNAs/genética , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Perfilação da Expressão Gênica , Biomarcadores , Idoso , Prognóstico , TranscriptomaRESUMO
BACKGROUND: Traumatic brain injury (TBI) is a significant global health concern and is characterized by brain dysfunction resulting from external physical forces, leading to brain pathology and neuropsychiatric disorders such as anxiety. This study investigates the effects of TC-DAPK6 on tau hyper-phosphorylation, gene expression, anxiety, and behavior impairment in the TBI mice model. METHODS AND RESULTS: A weight drop model induced the TBI and the anxiety levels were evaluated using an elevated plus maze (EPM) test. TC-DAPK6 was intraperitoneally administered one-month post-TBI and continued for two months. The total cis-p-tau ratio in the brain was assessed using western blot and immunofluorescence staining. Molecular analysis was conducted on Aff2, Zkscan16, Kcna1, Pcdhac2, and Pcdhga8 to investigate the function and pathogenic role of TC-DAPK6 in neurological diseases in the cerebral cortex tissues of TBI-model mice, and the results were compared with TC-DAPK6 TBI-treatment group. The anxiety level and phosphorylation of tau protein in the TBI group were significantly increased compared to the sham groups and decreased substantially in the TBI-treatment group after TC-DAPK6 administration; the TBI group mostly spent their time with open arms. TC-DAPK6 decreased the expression level of genes as much as the sham group. Meanwhile, KCNA1 showed the highest fold of changes in the TBI and TBI-treatment groups. CONCLUSIONS: The study demonstrates a clear association between cis-p-tau and neuro-related gene expression levels in TBI-induced mice. Targeting these pathways with DAPK1 inhibitors, shows promise for therapeutic interventions in TBI and related neurodegenerative disorders.
Assuntos
Lesões Encefálicas Traumáticas , Modelos Animais de Doenças , Proteínas tau , Animais , Lesões Encefálicas Traumáticas/genética , Lesões Encefálicas Traumáticas/metabolismo , Lesões Encefálicas Traumáticas/patologia , Camundongos , Proteínas tau/metabolismo , Proteínas tau/genética , Masculino , Fosforilação , Ansiedade/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Expressão Gênica/genética , Caderinas/genética , Caderinas/metabolismoRESUMO
Traumatic brain injury (TBI), which is characterized by acute neurological dysfunction, is also one of the most widely recognized environmental risk factors for various neurological and psychiatric disorders. However, the role of TBI in neurological perturbation and the mechanisms underlying these disorders remain unknown. We evaluated transcriptional changes in cells of the frontal cortex after TBI by exploiting single-cell RNA sequencing (scRNA-Seq). We adopted the gene expression omnibus and scRNA-Seq to identify the mediation by secretogranin II (SCG2) of TBI-induced schizophrenia. Astrocytes are a principal source of SCG2 in the frontal cortex after TBI. Our analysis indicated that SCG2-triggered disruption of the blood-brain barrier (BBB) via the CypA-MMP-9 signaling pathway. Furthermore, astrocytic SCG2 knockout in the frontal cortex reduced BBB damage, mitigated inflammation, and inhibited schizophrenia after TBI. In conclusion, we identified the SCG2-CypA-MMP-9 signaling pathway in reactive astrocytes as a key switch in the protection of the BBB and provided a novel therapeutic avenue for treating psychiatric disorders after TBI.
Assuntos
Barreira Hematoencefálica , Lesões Encefálicas Traumáticas , Camundongos Endogâmicos C57BL , Esquizofrenia , Animais , Masculino , Camundongos , Astrócitos/metabolismo , Barreira Hematoencefálica/metabolismo , Lesões Encefálicas Traumáticas/metabolismo , Lesões Encefálicas Traumáticas/patologia , Metaloproteinase 9 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/genética , Camundongos Knockout , Esquizofrenia/metabolismo , Transdução de SinaisRESUMO
Endoplasmic reticulum stress (ERS) plays an essential role in the development of traumatic brain injury (TBI). We aimed to identify and validate the potential ERS-related genes of TBI through bioinformatics analysis and in vitro cell experiment. A total of 19 TBI and ERS-related genes were obtained from the GeneCards database and Comparative Toxicogenomics Database (CTD). Enrichment analysis primarily enriched in apoptosis. NFE2L2 was identified as a hub gene based on the protein-protein interactions (PPI) network that combined seven ranked methods included in cytoHubba. To further explore the effect of Nrf2, the protein encoded by NFE2L2, on ERS-induced apoptosis, we conducted cell experiments with tert-butylhydroquinone (tBHQ), the classical inducer of Nrf2. Western blot suggested tBHQ pretreatment could diminish ERS and reduce the protein expressions of apoptosis in the primary cultured neuron injury model. These data may establish some theoretical basis for the treatment of TBI and provide inspiration and innovative ideas for clinicians and pathologists to understand TBI comprehensively.
Assuntos
Apoptose , Lesões Encefálicas Traumáticas , Estresse do Retículo Endoplasmático , Hidroquinonas , Fator 2 Relacionado a NF-E2 , Lesões Encefálicas Traumáticas/genética , Lesões Encefálicas Traumáticas/metabolismo , Animais , Hidroquinonas/farmacologia , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Ratos , Células Cultivadas , Neurônios/metabolismo , Ratos Sprague-Dawley , Mapas de Interação de ProteínasRESUMO
Iron is a critical transition metal required to sustain a healthy central nervous system. Iron is involved in metabolic reactions, enzymatic activity, myelinogenesis, and oxygen transport. However, in several pathological conditions such as cancer, neurodegeneration, and neurotrauma iron becomes elevated. Excessive iron can have deleterious effects leading to reactive oxygen species (ROS) via the Fenton reaction. Iron-derived ROS are known to drive several mechanisms such as cell death pathways including ferroptosis, necroptosis, and pyroptosis. Excessive iron present in the post-traumatic brain could trigger these harmful pathways potentiating the high rates of morbidity and mortality. In the present review, we will discuss how iron plays an intricate role in initiating ferroptosis, necroptosis, and pyroptosis, examine their potential link to traumatic brain injury morbidity and mortality, and suggest therapeutic targets.
Assuntos
Lesões Encefálicas Traumáticas , Ferroptose , Ferro , Necroptose , Piroptose , Piroptose/fisiologia , Humanos , Ferroptose/fisiologia , Ferro/metabolismo , Necroptose/fisiologia , Animais , Lesões Encefálicas Traumáticas/metabolismo , Lesões Encefálicas Traumáticas/patologia , Espécies Reativas de Oxigênio/metabolismoRESUMO
Wu et al. (2021) investigated the neuroprotective effects of hypoxia preconditioning (HPC) in a rat model of traumatic brain injury (TBI). The study demonstrated that HPC enhances brain resilience to TBI by upregulating glucose transporters GLUT1 and GLUT3 through the HIF-1α signaling pathway. Comprehensive molecular and histological analyses confirmed increased expression of these transporters, correlating with reduced neuronal apoptosis and cerebral edema. The robust methodology, including rigorous statistical validation and time-course assessments, underscores HPC's potential therapeutic role in mitigating neuronal loss and improving glucose transport post-injury. However, the study could be strengthened by incorporating additional preconditioning controls, comparative analyses with other neuroprotective strategies, and exploring downstream metabolic effects in greater detail. Furthermore, expanding the research to include diverse animal models and examining sex-dependent responses would enhance the generalizability and translational relevance of the findings. Future studies should also integrate metabolic flux analysis and advanced imaging techniques to further elucidate HPC's mechanisms of action.
Assuntos
Lesões Encefálicas Traumáticas , Glucose , Subunidade alfa do Fator 1 Induzível por Hipóxia , Neurônios , Transdução de Sinais , Animais , Lesões Encefálicas Traumáticas/metabolismo , Lesões Encefálicas Traumáticas/terapia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Ratos , Glucose/metabolismo , Transdução de Sinais/fisiologia , Neurônios/metabolismo , Precondicionamento Isquêmico/métodos , Transportador de Glucose Tipo 1/metabolismo , Transportador de Glucose Tipo 3/metabolismo , Proteínas Facilitadoras de Transporte de Glucose/metabolismoRESUMO
Traumatic brain injury (TBI) is a major public health concern that can result in long-term neurological impairments. Calpain is a calcium-dependent cysteine protease that is activated within minutes after TBI, and sustained calpain activation is known to contribute to neurodegeneration and blood-brain barrier dysregulation. Based on its role in disease progression, calpain inhibition has been identified as a promising therapeutic target. Efforts to develop therapeutics for calpain inhibition would benefit from the ability to measure calpain activity with spatial precision within the injured tissue. In this work, we designed an activity-based nanotheranostic (ABNT) that can both sense and inhibit calpain activity in TBI. To sense calpain activity, we incorporated a peptide substrate of calpain flanked by a fluorophore/quencher pair. To inhibit calpain activity, we incorporated calpastatin peptide, an endogenous inhibitor of calpain. Both sensor and inhibitor peptides were scaffolded onto a polymeric nanoscaffold to create our ABNT. We show that in the presence of recombinant calpain, our ABNT construct is able to sense and inhibit calpain activity. In a mouse model of TBI, systemically administered ABNT can access perilesional brain tissue through passive accumulation and inhibit calpain activity in the cortex and hippocampus. In an analysis of cellular calpain activity, we observe the ABNT-mediated inhibition of calpain activity in neurons, endothelial cells, and microglia of the cortex. In a comparison of neuronal calpain activity by brain structure, we observe greater ABNT-mediated inhibition of calpain activity in cortical neurons compared to that in hippocampal neurons. Furthermore, we found that apoptosis was dependent on both calpain inhibition and brain structure. We present a theranostic platform that can be used to understand the regional and cell-specific therapeutic inhibition of calpain activity to help inform drug design for TBI.
Assuntos
Lesões Encefálicas Traumáticas , Calpaína , Calpaína/antagonistas & inibidores , Calpaína/metabolismo , Lesões Encefálicas Traumáticas/tratamento farmacológico , Lesões Encefálicas Traumáticas/patologia , Lesões Encefálicas Traumáticas/metabolismo , Animais , Camundongos , Masculino , Camundongos Endogâmicos C57BL , Peptídeos/química , Peptídeos/farmacologia , Peptídeos/síntese química , HumanosRESUMO
INTRODUCTION: Traumatic brain injury (TBI) is a complex pathophysiological process, and increasing attention has been paid to the important role of post-synaptic density (PSD) proteins, such as glutamate receptors. Our previous study showed that a PSD protein Arc/Arg3.1 (Arc) regulates endoplasmic reticulum (ER) stress and neuronal necroptosis in traumatic injury in vitro. AIM: In this study, we investigated the expression, regulation and biological function of Arc in both in vivo and in vitro experimental TBI models. RESULTS: Traumatic neuronal injury (TNI) induced a temporal upregulation of Arc in cortical neurons, while TBI resulted in sustained increase in Arc expression up to 24 h in rats. The increased expression of Arc was mediated by the activity of metabotropic glutamate receptor 5 (mGluR5), but not dependent on the intracellular calcium (Ca2+) release. By using inhibitors and antagonists, we found that TNI regulates Arc expression via Gq protein and protein turnover. In addition, overexpression of Arc protects against TBI-induced neuronal injury and motor dysfunction both in vivo and in vitro, whereas the long-term cognitive function was not altered. To determine the role of Arc in mGluR5-induced protection, lentivirus-mediated short hairpin RNA (shRNA) transfection was performed to knockdown Arc expression. The mGluR5 agonist (RS)-2-chloro-5-hydroxyphenylglycine (CHPG)-induced protection against TBI was partially prevented by Arc knockdown. Furthermore, the CHPG-induced attenuation of Ca2+ influx after TNI was dependent on Arc activation and followed regulation of AMPAR subunits. The results of Co-IP and Ca2+ imaging showed that the Arc-Homer1 interaction contributes to the CHPG-induced regulation of intracellular Ca2+ release. CONCLUSION: In summary, the present data indicate that the mGluR5-mediated Arc activation is a protective mechanism that attenuates neurotoxicity following TBI through the regulation of intracellular Ca2+ hemostasis. The AMPAR-associated Ca2+ influx and ER Ca2+ release induced by Homer1-IP3R pathway might be involved in this protection.
Assuntos
Lesões Encefálicas Traumáticas , Proteínas do Citoesqueleto , Proteínas de Arcabouço Homer , Proteínas do Tecido Nervoso , Neurônios , Ratos Sprague-Dawley , Receptor de Glutamato Metabotrópico 5 , Animais , Lesões Encefálicas Traumáticas/metabolismo , Lesões Encefálicas Traumáticas/patologia , Receptor de Glutamato Metabotrópico 5/metabolismo , Receptor de Glutamato Metabotrópico 5/antagonistas & inibidores , Masculino , Proteínas do Tecido Nervoso/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Citoesqueleto/metabolismo , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/biossíntese , Ratos , Proteínas de Arcabouço Homer/metabolismo , Neurônios/metabolismo , Neurônios/efeitos dos fármacos , Modelos Animais de Doenças , Células Cultivadas , Córtex Cerebral/metabolismo , Cálcio/metabolismo , Glicina/análogos & derivados , FenilacetatosRESUMO
The interplay between gut microbiota and host health is crucial for maintaining the overall health of the body and brain, and it is even more crucial how changes in the bacterial profile can influence the aftermath of traumatic brain injury (TBI). We studied the effects of probiotic treatment after TBI to identify potential changes in hepatic lipid species relevant to brain function. Bioinformatic analysis of the gut microbiota indicated a significant increase in the Firmicutes/Bacteroidetes ratio in the probiotic-treated TBI group compared to sham and untreated TBI groups. Although strong correlations between gut bacteria and hepatic lipids were found in sham mice, TBI disrupted these links, and probiotic treatment did not fully restore them. Probiotic treatment influenced systemic glucose metabolism, suggesting altered metabolic regulation. Behavioral tests confirmed memory improvement in probiotic-treated TBI mice. While TBI reduced hippocampal mRNA expression of CaMKII and CREB, probiotics reversed these effects yet did not alter BDNF mRNA levels. Elevated pro-inflammatory markers TNF-α and IL1-ß in TBI mice were not significantly affected by probiotic treatment, pointing to different mechanisms underlying the probiotic benefits. In summary, our study suggests that TBI induces dysbiosis, alters hepatic lipid profiles, and preemptive administration of Lactobacillus helveticus and Bifidobacterium longum probiotics can counter neuroplasticity deficits and memory impairment. Altogether, these findings highlight the potential of probiotics for attenuating TBI's detrimental cognitive and metabolic effects through gut microbiome modulation and hepatic lipidomic alteration, laying the groundwork for probiotics as a potential TBI therapy.