Protein profiling in serum after traumatic brain injury in rats reveals potential injury markers

Research progress in the application of proteomics technology in brain injury

The aim of this article is to review the application progress of proteomics technology in brain injury research in recent years, point out the current problems that need to be overcome, and explore the application prospects of proteomics analysis in brain injury. This study also aims to retrieve all literature on brain injury and proteomics and summarize it. Through searching and screening, the widespread application of proteomics technology in the treatment of traumatic brain injury (TBI) and the use of a large number of TBI biomarkers were discovered. The pathways mediated by some biomarkers and the physiological and pathological mechanisms of occurrence were elucidated. The current classification of brain injury is mainly based on subjective evaluation of clinical symptoms, combined with objective imaging. However, its practical value is often limited when applied to prognosis evaluation in brain injury. Proteomics technology can make up for this deficiency and provide a reference for the prevention and treatment of brain injury.

Advances in neuroproteomics for neurotrauma: unraveling insights for personalized medicine and future prospects

Neuroproteomics, an emerging field at the intersection of neuroscience and proteomics, has garnered significant attention in the context of neurotrauma research. Neuroproteomics involves the quantitative and qualitative analysis of nervous system components, essential for understanding the dynamic events involved in the vast areas of neuroscience, including, but not limited to, neuropsychiatric disorders, neurodegenerative disorders, mental illness, traumatic brain injury, chronic traumatic encephalopathy, and other neurodegenerative diseases. With advancements in mass spectrometry coupled with bioinformatics and systems biology, neuroproteomics has led to the development of innovative techniques such as microproteomics, single-cell proteomics, and imaging mass spectrometry, which have significantly impacted neuronal biomarker research. By analyzing the complex protein interactions and alterations that occur in the injured brain, neuroproteomics provides valuable insights into the pathophysiological mechanisms underlying neurotrauma. This review explores how such insights can be harnessed to advance personalized medicine (PM) approaches, tailoring treatments based on individual patient profiles. Additionally, we highlight the potential future prospects of neuroproteomics, such as identifying novel biomarkers and developing targeted therapies by employing artificial intelligence (AI) and machine learning (ML). By shedding light on neurotrauma's current state and future directions, this review aims to stimulate further research and collaboration in this promising and transformative field.

Study of Transcriptomic Analysis of Yak (Bos grunniens) and Cattle (Bos taurus) Pulmonary Artery Smooth Muscle Cells under Oxygen Concentration Gradients and Differences in Their Lung Histology and Expression of Pyruvate Dehydrogenase Kinase 1-Related Factors

The aim of this study was to investigate the molecular mechanisms by which hypoxia affects the biological behavior of yak PASMCs, the changes in the histological structure of yak and cattle lungs, and the relationships and regulatory roles that exist regarding the differences in the distribution and expression of PDK1 and its hypoxia-associated factors screened for their role in the adaptation of yak lungs to the plateau hypoxic environment. The results showed that, at the level of transcriptome sequencing, the molecular regulatory mechanisms of the HIF-1 signaling pathway, glucose metabolism pathway, and related factors (HK2/PGK1/ENO1/ENO3/ALDOC/ALDOA) may be closely related to the adaptation of yaks to the hypoxic environment of the plateau; at the tissue level, the presence of filled alveoli and semi-filled alveoli, thicker alveolar septa and basement membranes, a large number of erythrocytes, capillary distribution, and collagen fibers accounted for all levels of fine bronchioles in the lungs of yaks as compared to cattle. A higher percentage of goblet cells was found in the fine bronchioles of yaks, and PDK1, HIF-1α, and VEGF were predominantly distributed and expressed in the monolayers of ciliated columnar epithelium in the branches of the terminal fine bronchioles of yak and cattle lungs, with a small amount of it distributed in the alveolar septa; at the molecular level, the differences in PDK1 mRNA relative expression in the lungs of adult yaks and cattle were not significant (p > 0.05), the differences in HIF-1α and VEGF mRNA relative expression were significant (p < 0.05), and the expression of PDK1 and HIF-1α proteins in adult yaks was stronger than that in adult cattle. PDK1 and HIF-1α proteins were more strongly expressed in adult yaks than in adult cattle, and the difference was highly significant (p < 0.01); the relative expression of VEGF proteins was not significantly different between adult yaks and cattle (p > 0.05). The possible regulatory relationship between the above results and the adaptation of yak lungs to the plateau hypoxic environment paves the way for the regulatory mechanisms of PDK1, HIF-1α, and VEGF, and provides basic information for studying the mechanism of hypoxic adaptation of yaks in the plateau. At the same time, it provides a reference for human hypoxia adaptation and a target for the prevention and treatment of plateau diseases in humans and plateau animals.

Neural-Cardiac Inflammasome Axis after Traumatic Brain Injury

Traumatic brain injury (TBI) affects not only the brain but also peripheral organs like the heart and the lungs, which influences long-term outcomes. A heightened systemic inflammatory response is often induced after TBI, but the underlying pathomechanisms that contribute to co-morbidities remain poorly understood. Here, we investigated whether extracellular vehicles (EVs) containing inflammasome proteins are released after severe controlled cortical impact (CCI) in C57BL/6 mice and cause activation of inflammasomes in the heart that result in tissue damage. The atrium of injured mice at 3 days after TBI showed a significant increase in the levels of the inflammasome proteins AIM2, ASC, caspases-1, -8 and -11, whereas IL-1β was increased in the ventricles. Additionally, the injured cortex showed a significant increase in IL-1β, ASC, caspases-1, -8 and -11 and pyrin at 3 days after injury when compared to the sham. Serum-derived extracellular vesicles (EVs) from injured patients were characterized with nanoparticle tracking analysis and Ella Simple Plex and showed elevated levels of the inflammasome proteins caspase-1, ASC and IL-18. Mass spectrometry of serum-derived EVs from mice after TBI revealed a variety of complement- and cardiovascular-related signaling proteins. Moreover, adoptive transfer of serum-derived EVs from TBI patients resulted in inflammasome activation in cardiac cells in culture. Thus, TBI elicits inflammasome activation, primarily in the atrium, that is mediated, in part, by EVs that contain inflammasome- and complement-related signaling proteins that are released into serum and contribute to peripheral organ systemic inflammation, which increases inflammasome activation in the heart.

Proteomic profiles in cerebrospinal fluid predicted death and disability in term infants with perinatal asphyxia: A pilot study

Aim

Perinatal asphyxia, resulting in hypoxic‐ischaemic encephalopathy (HIE), has been associated with high mortality rates and severe lifelong neurodevelopmental disabilities. Our aim was to study the association between the proteomic profile in cerebrospinal fluid (CSF) and the degree of HIE and long‐term outcomes.

Methods

We prospectively enrolled 18‐term born infants with HIE and 10‐term born controls between 2000 and 2004 from the Karolinska University Hospital. An antibody suspension bead array and FlexMap3D analysis was used to characterise 178 unique brain‐derived and inflammation associated proteins in their CSF.

Results

Increased CSF concentrations of several brain‐specific proteins were observed in the proteome of HIE patients compared with the controls. An upregulation of neuroinflammatory pathways was also noted and this was confirmed by pathway analysis. Principal component analysis revealed a gradient from favourable to unfavourable HIE grades and outcomes. The proteins that provided strong predictors were structural proteins, including myelin basic protein and alpha‐II spectrin. The functional proteins included energy‐related proteins like neuron‐specific enolase and synaptic regulatory proteins. Increased CSF levels of 51 proteins correlated with adverse outcomes in infants with HIE.

Conclusion

Brain‐specific proteins and neuroinflammatory mediators in CSF may predict HIE degrees and outcomes after perinatal asphyxia.

Aldolase C Profiling in Serum after Mild Traumatic Brain Injury: A Prospective Cohort Study

BACKGROUND

After a traumatic brain injury (TBI), in addition to clinical indices, the serum level of neurological biomarkers may provide valuable diagnostic and prognostic information. The present study aimed to investigate the aldolase C (ALDOC) profile in serum for early diagnosis of brain damage in patients with mild TBI (mTBI) presented to the Emergency Department (ED).

METHODS

A single-center prospective cohort study was carried out in 2018-2019 at Imam Khomeini Hospital affiliated with Mazandaran University of Medical Sciences, Sari, Iran. A total of 89 patients with mTBI were enrolled in the study. Blood samples were taken within three hours after head trauma to measure ALDOC serum levels. Brain CT scan was used as the gold standard. Statistical analysis was performed using the Kruskal Wallis, Mann-Whitney U, and Chi square tests. The receiver-operating characteristic (ROC) curve plot was used to determine the optimal cutoff point for ALDOC. The sensitivity and specificity of the determined cutoff point were calculated. P values less than 0.05 were considered statistically significant.

RESULTS

Of the 89 patients, the CT scan findings showed a positive TBI in 30 (33.7%) of the patients and in 59 (66.3%) a negative TBI. The median ALDOC serum level in the patients with positive CT scan findings (8.35 ng/mL [IQR: 1.65]) was significantly higher than those with negative CT scan findings (5.3 ng/mL [IQR: 6.9]) (P<0.001). The optimal cutoff point for ALDOC serum level was 6.95 ng/mL, and the area under the curve was 99.6% (P<0.001). The sensitivity and specificity of the determined cutoff point were 100% and 98%, respectively.

CONCLUSION

The ALDOC serum level in patients with mTBI significantly correlates with the pathologic findings of the brain CT scan. This biomarker, with 100% sensitivity, is a suitable tool to detect brain structural abnormalities in mTBI patients.

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

Activation 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.

Fluid proteomics of CSF and serum reveal important neuroinflammatory proteins in blood-brain barrier disruption and outcome prediction following severe traumatic brain injury: a prospective, observational study

BACKGROUND

Severe traumatic brain injury (TBI) is associated with blood-brain barrier (BBB) disruption and a subsequent neuroinflammatory process. We aimed to perform a multiplex screening of brain enriched and inflammatory proteins in blood and cerebrospinal fluid (CSF) in order to study their role in BBB disruption, neuroinflammation and long-term functional outcome in TBI patients and healthy controls.

METHODS

We conducted a prospective, observational study on 90 severe TBI patients and 15 control subjects. Clinical outcome data, Glasgow Outcome Score, was collected after 6-12 months. We utilized a suspension bead antibody array analyzed on a FlexMap 3D Luminex platform to characterize 177 unique proteins in matched CSF and serum samples. In addition, we assessed BBB disruption using the CSF-serum albumin quotient (QA), and performed Apolipoprotein E-genotyping as the latter has been linked to BBB function in the absence of trauma. We employed pathway-, cluster-, and proportional odds regression analyses. Key findings were validated in blood samples from an independent TBI cohort.

RESULTS

TBI patients had an upregulation of structural CNS and neuroinflammatory pathways in both CSF and serum. In total, 114 proteins correlated with QA, among which the top-correlated proteins were complement proteins. A cluster analysis revealed protein levels to be strongly associated with BBB integrity, but not carriage of the Apolipoprotein E4-variant. Among cluster-derived proteins, innate immune pathways were upregulated. Forty unique proteins emanated as novel independent predictors of clinical outcome, that individually explained ~ 10% additional model variance. Among proteins significantly different between TBI patients with intact or disrupted BBB, complement C9 in CSF (p = 0.014, ΔR2 = 7.4%) and complement factor B in serum (p = 0.003, ΔR2 = 9.2%) were independent outcome predictors also following step-down modelling.

CONCLUSIONS

This represents the largest concomitant CSF and serum proteomic profiling study so far reported in TBI, providing substantial support to the notion that neuroinflammatory markers, including complement activation, predicts BBB disruption and long-term outcome. Individual proteins identified here could potentially serve to refine current biomarker modelling or represent novel treatment targets in severe TBI.

Astaxanthin ameliorates oxidative stress and neuronal apoptosis via SIRT1/NRF2/Prx2/ASK1/p38 after traumatic brain injury in mice

BACKGROUND AND PURPOSE

Oxidative stress and neuronal apoptosis play key roles in traumatic brain injury. We investigated the protective effects of astaxanthin against traumatic brain injury and its underlying mechanisms of action.

EXPERIMENTAL APPROACH

A weight-drop model of traumatic brain injury in vivo and hydrogen peroxide exposure in vitro model were established. Brain oedema, behaviour tests, western blot, biochemical analysis, lesion volume, histopathological study and cell viability were performed.

KEY RESULTS

Astaxanthin significantly reduced oxidative insults on Days 1, 3 and 7 after traumatic brain injury. Neuronal apoptosis was also ameliorated on Day 3. Additionally, astaxanthin improved neurological functions up to 3 weeks after traumatic brain injury. Astaxanthin treatment dramatically enhanced the expression of peroxiredoxin 2 (Prx2), nuclear factor-erythroid 2-related factor 2 (NRF2/Nrf2) and sirtuin 1 (SIRT1), while it down-regulated the phosphorylation of apoptosis signal-regulating kinase 1 (ASK1) and p38. Inhibition of Prx2 by siRNA injection reversed the beneficial effects of astaxanthin against traumatic brain injury. Additionally, Nrf2 knockout prevented the neuroprotective effects of astaxanthin in traumatic brain injury. In contrast, overexpression of Prx2 in Nrf2 knockout mice attenuated the secondary brain injury after traumatic brain injury. Moreover, inhibiting SIRT1 by EX527 dramatically inhibited the neuroprotective effects of astaxanthin and suppressed SIRT1/Nrf2/Prx2/ASK1/p38 pathway both in vivo and in vitro.

CONCLUSION AND IMPLICATIONS

Astaxanthin improved the neurological functions and protected the brain from injury after traumatic brain injury, primarily by reducing oxidative stress and neuronal death via SIRT1/Nrf2/Prx2/ASK1/p38 signalling pathway and might be a new candidate to ameliorate traumatic brain injury.

"Omics" in traumatic brain injury: novel approaches to a complex disease

BACKGROUND

To date, there is neither any pharmacological treatment with efficacy in traumatic brain injury (TBI) nor any method to halt the disease progress. This is due to an incomplete understanding of the vast complexity of the biological cascades and failure to appreciate the diversity of secondary injury mechanisms in TBI. In recent years, techniques for high-throughput characterization and quantification of biological molecules that include genomics, proteomics, and metabolomics have evolved and referred to as omics.

METHODS

In this narrative review, we highlight how omics technology can be applied to potentiate diagnostics and prognostication as well as to advance our understanding of injury mechanisms in TBI.

RESULTS

The omics platforms provide possibilities to study function, dynamics, and alterations of molecular pathways of normal and TBI disease states. Through advanced bioinformatics, large datasets of molecular information from small biological samples can be analyzed in detail and provide valuable knowledge of pathophysiological mechanisms, to include in prognostic modeling when connected to clinically relevant data. In such a complex disease as TBI, omics enables broad categories of studies from gene compositions associated with susceptibility to secondary injury or poor outcome, to potential alterations in metabolites following TBI.

CONCLUSION

The field of omics in TBI research is rapidly evolving. The recent data and novel methods reviewed herein may form the basis for improved precision medicine approaches, development of pharmacological approaches, and individualization of therapeutic efforts by implementing mathematical "big data" predictive modeling in the near future.

Alterations in Plasma microRNA and Protein Levels in War Veterans with Chronic Mild Traumatic Brain Injury

Blast-related mild traumatic brain injury (mTBI) is considered the "signature" injury of the wars in Iraq and Afghanistan. Identifying biomarkers that could aid in diagnosis and assessment of chronic mTBI are urgently needed, as little progress has been made toward identifying blood-based biomarkers of repetitive mTBI in the chronic state. Addressing this knowledge gap is especially important in the population of military veterans who are receiving assessment and care often years after their last exposure. Circulating microRNAs (miRNAs), especially those encapsulated in extracellular vesicles (EVs), have gained interest as a source of biomarkers for neurological conditions. To identify biomarkers for chronic mTBI, we used next generation sequencing (NGS) to analyze miRNAs in plasma and plasma-derived EVs from 27 Iraq and Afghanistan war veterans with blast-related chronic mTBI, 11 deployed veteran non-TBI controls, and 31 civilian controls. We identified 32 miRNAs in plasma and 45 miRNAs in EVs that significantly changed in the chronic mTBI cohort compared with control groups. These miRNAs were predominantly associated with pathways involved in neuronal function, vascular remodeling, blood-brain barrier integrity, and neuroinflammation. In addition, the plasma proteome was analyzed and showed that the concentrations of C-reactive protein (CRP) and membrane metalloendopeptidase (MME) were elevated in chronic mTBI samples. These plasma miRNAs and proteins could potentially be used as biomarkers and provide insights into the molecular processes associated with the long-term health outcomes associated with blast-related chronic mTBI.

Ferroptosis-relevant mechanisms and biomarkers for therapeutic interventions in traumatic brain injury

Traumatic brain injury (TBI) is one of the most significant health care problems worldwide, causing disability and death especially among young individuals. Although a large range of agents and therapies have been proved beneficial to lesions post-TBI to some extent, effective treatments have not been translated to the clinic. As a newly discovered form of iron-dependent regulated cell death, ferroptosis has been implicated in TBI. In this review, we update the current state of knowledge related to second injuries post-TBI, including ferroptosis, oxidative stress, mitochondrial dysfunction, neuroinflammation and so on, which often lead to chronic symptoms and long-term disability. This review systematically summarizes the latest progress in the pathophysiological mechanisms of TBI, with a focus on providing references for proposing new multi-molecular targets for comprehensive therapeutic strategies based on ferroptosis-relevant mechanisms. In addition, biomarkers are essential diagnostic and prognostic tools in TBI. Several biomarkers associated with the outcome of TBI have been listed in this article, such as Pde10a, MDA, UCH-L1, S100A9, S100B, ALDOC, ACSL4, MBP and F2-Isoprostane. Therefore, the understating of ferroptosis-relevant mechanisms and biomarkers may contribute to development of promising therapies for TBI clinical trials.

Brain-Immune Interactions and Neuroinflammation After Traumatic Brain Injury

Traumatic brain injury (TBI) is the principal cause of death and disability in children and young adults. Clinical and preclinical research efforts have been carried out to understand the acute, life-threatening pathophysiological events happening after TBI. In the past few years, however, it was recognized that TBI causes significant morbidity weeks, months, or years after the initial injury, thereby contributing substantially to the overall burden of TBI and the decrease of life expectancy in these patients. Long-lasting sequels of TBI include cognitive decline/dementia, sensory-motor dysfunction, and psychiatric disorders, and most important for patients is the need for socio-economic rehabilitation affecting their quality of life. Cerebrovascular alterations have been described during the first week after TBI for direct consequence development of neuroinflammatory process in relation to brain edema. Within the brain-immune interactions, the complement system, which is a family of blood and cell surface proteins, participates in the pathophysiology process. In fact, the complement system is part of the primary defense and clearance component of innate and adaptive immune response. In this review, the complement activation after TBI will be described in relation to the activation of the microglia and astrocytes as well as the blood-brain barrier dysfunction during the first week after the injury. Considering the neuroinflammatory activity as a causal element of neurological handicaps, some major parallel lines of complement activity in multiple sclerosis and Alzheimer pathologies with regard to cognitive impairment will be discussed for chronic TBI. A better understanding of the role of complement activation could facilitate the development of new therapeutic approaches for TBI.

Therapeutic Inhibition of the Complement System in Diseases of the Central Nervous System

The complement system plays critical roles in development, homeostasis, and regeneration in the central nervous system (CNS) throughout life; however, complement dysregulation in the CNS can lead to damage and disease. Complement proteins, regulators, and receptors are widely expressed throughout the CNS and, in many cases, are upregulated in disease. Genetic and epidemiological studies, cerebrospinal fluid (CSF) and plasma biomarker measurements and pathological analysis of post-mortem tissues have all implicated complement in multiple CNS diseases including multiple sclerosis (MS), neuromyelitis optica (NMO), neurotrauma, stroke, amyotrophic lateral sclerosis (ALS), Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD). Given this body of evidence implicating complement in diverse brain diseases, manipulating complement in the brain is an attractive prospect; however, the blood-brain barrier (BBB), critical to protect the brain from potentially harmful agents in the circulation, is also impermeable to current complement-targeting therapeutics, making drug design much more challenging. For example, antibody therapeutics administered systemically are essentially excluded from the brain. Recent protocols have utilized "Trojan horse" techniques to transport therapeutics across the BBB or used osmotic shock or ultrasound to temporarily disrupt the BBB. Most research to date exploring the impact of complement inhibition on CNS diseases has been in animal models, and some of these studies have generated convincing data; for example, in models of MS, NMO, and stroke. There have been a few recent clinical trials of available anti-complement drugs in CNS diseases associated with BBB impairment, for example the use of the anti-C5 monoclonal antibody (mAb) eculizumab in NMO, but for most CNS diseases there have been no human trials of anti-complement therapies. Here we will review the evidence implicating complement in diverse CNS disorders, from acute, such as traumatic brain or spine injury, to chronic, including demyelinating, neuroinflammatory, and neurodegenerative diseases. We will discuss the particular problems of drug access into the CNS and explore ways in which anti-complement therapies might be tailored for CNS disease.

Current trends in biomarker discovery and analysis tools for traumatic brain injury

Traumatic brain injury (TBI) affects 1.7 million people in the United States each year, causing lifelong functional deficits in cognition and behavior. The complex pathophysiology of neural injury is a primary barrier to developing sensitive and specific diagnostic tools, which consequentially has a detrimental effect on treatment regimens. Biomarkers of other diseases (e.g. cancer) have provided critical insight into disease emergence and progression that lend to developing powerful clinical tools for intervention. Therefore, the biomarker discovery field has recently focused on TBI and made substantial advancements to characterize markers with promise of transforming TBI patient diagnostics and care. This review focuses on these key advances in neural injury biomarkers discovery, including novel approaches spanning from omics-based approaches to imaging and machine learning as well as the evolution of established techniques.

Protein Network Analysis of the Serum and Their Functional Implication in Patients Subjected to Traumatic Brain Injury

Traumatic brain injury (TBI) often leads to severe neurobehavioral impairment, but the underlying molecular mechanism remains to be elucidated. Here, we collected the sera from 23 patients (aged from 19 to 81 years old, third day after TBI as TBI-third group) subjected to TBI from The First Hospital of Kunming City, and the sera from 22 healthy donors (aged from 18 to 81 years old and as control group). Then, three samples from TBI-third group and three samples from control group were subjected to the protein microarray detection, and bioinformatics analysis. Then, enzyme-linked immunosorbent assay (ELISA) was used to verify significantly altered protein levels. Results showed that, when compared with the control group, all significantly differentially expressed proteins [DEPs, P < 0.05, FDR < 0.05, fold change (FC) > 2] contained 172 molecules in the TBI-third group, in which 65 proteins were upregulated, while 107 proteins were downregulated. The biological processes of these DEPs, mostly happened in the extracellular region and the extracellular region parts, are mainly involved in the regulation of cellular process, signaling and signal transduction, cell communication, response to stimuli, the immune system process and multicellular organismal development. Moreover, the essential molecular functions of them are cytokine activity, growth factor activity and morphogen activity. Additionally, the most significant pathways are enriched in cytokine–cytokine receptor interaction and PI3K-Akt signaling pathways among downregulated proteins, and pathways in cancer and cytokine–cytokine receptor interaction among upregulated proteins. Of these, we focused on the NGF, NT-3, IGF-2, HGF, NPY, CRP, MMP-9, and ICAM-2 with a high number of interactors in Protein–Protein Interaction (PPI) Network indicated by bioinformatics report. Furthermore, using ELISA test, we confirmed that all increase in the levels of NGF, NT-3, IGF-2, HGF, NPY, CRP, MMP-9, and ICAM-2 in the serum from TBI patients. Together, we determined the screened protein expressional profiles in serum for TBI patients, in which the cross-network between inflammatory factors and growth factors may play a crucial role in TBI damage and repair. Our findings could contribute to indication for the diagnosis and treatment of TBI in future translational medicine and clinical practice.

Roles of Aldolase Family Genes in Human Cancers and Diseases

The aldolase family members involved in metabolism and glycolysis are present in three isoforms: ALDOA, ALDOB, and ALDOC. Aldolases are differentially expressed in human tissues, and aberrant expression has been observed in several human diseases and cancer types. However, non-enzymatic functions through protein-protein interactions or epigenetic modifications have been reported in recent years. Using high-throughput screening and -omics database integration, aldolase has been validated as an independent clinical prognostic marker of human cancers. Therefore, the aim of this review was to provide potential clinical value from in silico predictions and also summarize well-known signaling axes or phenotypes in various cancer types. Finally, we discuss the role of aldolase in the treatment of human diseases and cancers.

Complement cascade on severe traumatic brain injury patients at the chronic unconscious stage: implication for pathogenesis

BACKGROUND

Patients who awake from severely traumatic brain injury (TBI) may remain unconscious for many years. Although behavioral assessment and functional imaging are currently used as diagnostic tools, the molecular basis underlying chronic condition has yet to be explored.

METHOD

Plasma samples were obtained at 3 time points (1, 3 and 6 months) from 18 patients with chronic disorders of consciousness who survived severe TBI, and 6 healthy volunteers. A coupled isobaric tag for relative and absolute quantitation (iTRAQ)-based proteomics approach was used to screen differentially expressed proteins (DEPs) between patients and controls. Potential molecular mechanisms were further discussed through bioinformatics analyses.

RESULT

In total, 300 plasma proteins <1% false discovery rates were identified and 32 proteins were consistently altered between patients and controls. Biological pathway analysis revealed that the DEPs were predominantly involved in complement cascade.

CONCLUSIONS

This study discussed potential mechanisms of complement cascade underlying chronic stage in severe TBI.

Structural imaging of mild traumatic brain injury may not be enough: overview of functional and metabolic imaging of mild traumatic brain injury

A majority of patients with traumatic brain injury (TBI) present as mild injury with no findings on conventional clinical imaging methods. Due to this difficulty of imaging assessment on mild TBI patients, there has been much emphasis on the development of diffusion imaging modalities such as diffusion tensor imaging (DTI). However, basic science research in TBI shows that many of the functional and metabolic abnormalities in TBI may be present even in the absence of structural damage. Moreover, structural damage may be present at a microscopic and molecular level that is not detectable by structural imaging modality. The use of functional and metabolic imaging modalities can provide information on pathological changes in mild TBI patients that may not be detected by structural imaging. Although there are various differences in protocols of positron emission tomography (PET), single photon emission computed tomography (SPECT), functional magnetic resonance imaging (fMRI), electroencephalography (EEG), and magnetoencephalography (MEG) methods, these may be important modalities to be used in conjunction with structural imaging in the future in order to detect and understand the pathophysiology of mild TBI. In this review, studies of mild TBI patients using these modalities that detect functional and metabolic state of the brain are discussed. Each modality's advantages and disadvantages are compared, and potential future applications of using combined modalities are explored.

Alpha-1-antitrypsin: a novel predictor for long-term recovery of chronic disorder of consciousness

BACKGROUND

The aim of this manuscript was to explore the molecular basis and identify novel biomarkers for the diagnosis and prognosis of patients with chronic disorder of consciousness.

METHODS

A coupled isobaric tag for relative and absolute quantitation-based approach was used to screen differentially expressed proteins (DEPs) between patients with chronic disorder of consciousness and healthy individuals. Candidate proteins were identified and measured. The Coma Recovery Scale-Revised (CRS-R) score was used to quantify the severity, and long-term recovery was assessed by Glasgow Outcome Scale (GOS).

RESULTS

Between patients and controls, a total of 77 DEPs were identified. Based on the DEPs, a network containing 50 nodes and 207 edges was built, and alpha-1-antitrypsin was marked as the hub protein. The results indicated that alpha-1-antitrypsin correlated with the CRS-R score with a correlation coefficient of 0.631, and an outcome at 12 months (8.5 ± 2.1 ng/ml in patients with GOS 1-2 vs. 6.8 ± 1.6 ng/ml in those with GOS 3-5, p = 0.002).

CONCLUSIONS

The data confirm the diagnostic and prognostic potential of alpha-1-antitrypsin in chronic disorder of consciousness, which may contribute to the development of novel therapeutic agents.

iTRAQ-Based Quantitative Proteomics Reveals the New Evidence Base for Traumatic Brain Injury Treated with Targeted Temperature Management

This study aimed to investigate the effects of targeted temperature management (TTM) modulation on traumatic brain injury (TBI) and the involved mechanisms using quantitative proteomics technology. SH-SY5Y and HT-22 cells were subjected to moderate stretch injury using the cell injury controller (CIC), followed by incubation at TTM (mild hypothermia, 32°C), or normothermia (37°C). The real-time morphological changes, cell cycle phase distribution, death, and cell viability were evaluated. Moderate TBI was produced by the controlled cortical impactor (CCI), and the effects of TTM on the neurological damage, neurodegeneration, cerebrovascular histopathology, and behavioral outcome were determined in vivo. Results showed that TTM treatment prevented TBI-induced neuronal necrosis in the brain, achieved a substantial reduction in neuronal death both in vitro and in vivo, reduced cortical lesion volume and neuronal loss, attenuated cerebrovascular histopathological damage, brain edema, and improved behavioral outcome. Using an iTRAQ proteomics approach, proteins that were significantly associated with TTM in experimental TBI were identified. Importantly, changes in four candidate molecules (plasminogen [PLG], antithrombin III [AT III], fibrinogen gamma chain [FGG], transthyretin [TTR]) were verified using TBI rat brain tissues and TBI human cerebrospinal fluid (CSF) samples. This study is one of the first to investigate the neuroprotective effects of TTM on the proteome of human and experimental models of TBI, providing an overall landscape of the TBI brain proteome and a scientific foundation for further assessment of candidate molecules associated with TTM for the promotion of reparative strategies post-TBI.

New astroglial injury-defined biomarkers for neurotrauma assessment

Traumatic brain injury (TBI) is an expanding public health epidemic with pathophysiology that is difficult to diagnose and thus treat. TBI biomarkers should assess patients across severities and reveal pathophysiology, but currently, their kinetics and specificity are unclear. No single ideal TBI biomarker exists. We identified new candidates from a TBI CSF proteome by selecting trauma-released, astrocyte-enriched proteins including aldolase C (ALDOC), its 38kD breakdown product (BDP), brain lipid binding protein (BLBP), astrocytic phosphoprotein (PEA15), glutamine synthetase (GS) and new 18-25kD-GFAP-BDPs. Their levels increased over four orders of magnitude in severe TBI CSF. First post-injury week, ALDOC levels were markedly high and stable. Short-lived BLBP and PEA15 related to injury progression. ALDOC, BLBP and PEA15 appeared hyper-acutely and were similarly robust in severe and mild TBI blood; 25kD-GFAP-BDP appeared overnight after TBI and was rarely present after mild TBI. Using a human culture trauma model, we investigated biomarker kinetics. Wounded (mechanoporated) astrocytes released ALDOC, BLBP and PEA15 acutely. Delayed cell death corresponded with GFAP release and proteolysis into small GFAP-BDPs. Associating biomarkers with cellular injury stages produced astroglial injury-defined (AID) biomarkers that facilitate TBI assessment, as neurological deficits are rooted not only in death of CNS cells, but also in their functional compromise.

Moderate blast exposure alters gene expression and levels of amyloid precursor protein

OBJECTIVE

To explore gene expression after moderate blast exposure (vs baseline) and proteomic changes after moderate- (vs low-) blast exposure.

METHODS

Military personnel (N = 69) donated blood for quantification of protein level, and peak pressure exposures were detected by helmet sensors before and during a blast training program (10 days total). On day 7, some participants (n = 29) sustained a moderate blast (mean peak pressure = 7.9 psi) and were matched to participants with no/low-blast exposure during the training (n = 40). PAXgene tubes were collected from one training site at baseline and day 10; RNA-sequencing day 10 expression was compared with each participant's own baseline samples to identify genes and pathways differentially expressed in moderate blast-exposed participants. Changes in amyloid precursor protein (APP) from baseline to the day of blast and following 2 days were evaluated. Symptoms were assessed using a self-reported form.

RESULTS

We identified 1,803 differentially expressed genes after moderate blast exposure; the most altered network was APP. Significantly reduced levels of peripheral APP were detected the day after the moderate blast exposure and the following day. Protein concentrations correlated with the magnitude of the moderate blast exposure on days 8 and 9. APP concentrations returned to baseline levels 3 days following the blast, likely due to increases in the genetic expression of APP. Onset of concentration problems and headaches occurred after moderate blast.

CONCLUSIONS

Moderate blast exposure results in a signature biological profile that includes acute APP reductions, followed by genetic expression increases and normalization of APP levels; these changes likely influence neuronal recovery.

Monitoring the Neuroinflammatory Response Following Acute Brain Injury

Traumatic brain injury (TBI) and subarachnoid hemorrhage (SAH) are major contributors to morbidity and mortality. Following the initial insult, patients may deteriorate due to secondary brain damage. The underlying molecular and cellular cascades incorporate components of the innate immune system. There are different approaches to assess and monitor cerebral inflammation in the neuro intensive care unit. The aim of this narrative review is to describe techniques to monitor inflammatory activity in patients with TBI and SAH in the acute setting. The analysis of pro- and anti-inflammatory cytokines in compartments of the central nervous system (CNS), including the cerebrospinal fluid and the extracellular fluid, represent the most common approaches to monitor surrogate markers of cerebral inflammatory activity. Each of these compartments has a distinct biology that reflects local processes and the cross-talk between systemic and CNS inflammation. Cytokines have been correlated to outcomes as well as ongoing, secondary injury progression. Alongside the dynamic, focal assay of humoral mediators, imaging, through positron emission tomography, can provide a global in vivo measurement of inflammatory cell activity, which reveals long-lasting processes following the initial injury. Compared to the innate immune system activated acutely after brain injury, the adaptive immune system is likely to play a greater role in the chronic phase as evidenced by T-cell-mediated autoreactivity toward brain-specific proteins. The most difficult aspect of assessing neuroinflammation is to determine whether the processes monitored are harmful or beneficial to the brain as accumulating data indicate a dual role for these inflammatory cascades following injury. In summary, the inflammatory component of the complex injury cascade following brain injury may be monitored using different modalities. Using a multimodal monitoring approach can potentially aid in the development of therapeutics targeting different aspects of the inflammatory cascade and improve the outcome following TBI and SAH.