Neuroglobin and Nogo-a as biomarkers for the severity and prognosis of traumatic brain injury

Expression of Acidic Fibrillar Protein and Neuroglobin in Thrombolytic Patients in Ischemic Stroke

Purpose

Glial fibrillary acidic protein (GFAP) and neuroglobin (NGB) are important biomarkers of cerebral hypoxia. For this reason, an attempt was made to assess their concentrations in various time intervals and their impact on the severity of neurological symptoms and functional prognosis of thrombolytic ischemic stroke patients.

Patients and Methods

The study involved 94 patients reporting to the emergency department of the Collegium Medicum University Hospital in Bydgoszcz within < 4.5 hours of the onset of stroke symptoms. GFAP and neuroglobin levels were measured in plasma at indicated times using a commercial ELISA kit.

Results

Based on the data gathered, statistically significant differences were found between the concentration of biomarkers in stroke patients and the control group. The concentrations of both biomarkers, GFAP and NGB, were elevated in patients after ischemic stroke and the changes in their concentrations in the subsequent stages of stroke may suggest their prognostic value strictly dependent on time. NGB was determined on the 7th day, and mRS - after a year (0.35). GFAP measured after 24 h and on day 7 could be a promising biomarker of functional outcome after one year (cut-off point ≤ 0.231 ng/mL, sensitivity 75.0%, specificity 61.2%, cut off point ≤ 0.235 ng/mL, sensitivity 75.0%, specificity 73.9%, respectively) and the severity of the patient's neurological condition. At GFAP concentrations above 0.25 ng/mL, measured within 24 hours, a sharp increase in mortality was observed in stroke patients. In the case of NGB, at the time of stroke occurrence (14 ng/mL) and after 24 hours (10-60 ng/mL). Differences in the concentrations of these biomarkers have been demonstrated in different stroke subtypes.

Conclusion

NGB and GFAP are important biomarkers of ischemic brain injury and may also participate in predicting neurological outcomes.

Post-stroke cognitive impairment: exploring molecular mechanisms and omics biomarkers for early identification and intervention

Post-stroke cognitive impairment (PSCI) is a major stroke consequence that has a severe impact on patients' quality of life and survival rate. For this reason, it is especially crucial to identify and intervene early in high-risk groups during the acute phase of stroke. Currently, there are no reliable and efficient techniques for the early diagnosis, appropriate evaluation, or prognostication of PSCI. Instead, plenty of biomarkers in stroke patients have progressively been linked to cognitive impairment in recent years. High-throughput omics techniques that generate large amounts of data and process it to a high quality have been used to screen and identify biomarkers of PSCI in order to investigate the molecular mechanisms of the disease. These techniques include metabolomics, which explores dynamic changes in the organism, gut microbiomics, which studies host-microbe interactions, genomics, which elucidates deeper disease mechanisms, transcriptomics and proteomics, which describe gene expression and regulation. We looked through electronic databases like PubMed, the Cochrane Library, Embase, Web of Science, and common databases for each omics to find biomarkers that might be connected to the pathophysiology of PSCI. As all, we found 34 studies: 14 in the field of metabolomics, 5 in the field of gut microbiomics, 5 in the field of genomics, 4 in the field of transcriptomics, and 7 in the field of proteomics. We discovered that neuroinflammation, oxidative stress, and atherosclerosis may be the primary causes of PSCI development, and that metabolomics may play a role in the molecular mechanisms of PSCI. In this study, we summarized the existing issues across omics technologies and discuss the latest discoveries of PSCI biomarkers in the context of omics, with the goal of investigating the molecular causes of post-stroke cognitive impairment. We also discuss the potential therapeutic utility of omics platforms for PSCI mechanisms, diagnosis, and intervention in order to promote the area's advancement towards precision PSCI treatment.

Prediction of early prognosis after traumatic brain injury by multifactor model

AIMS

To design a model to predict the early prognosis of patients with traumatic brain injury (TBI) based on parameters that can be quickly obtained in emergency conditions from medical history, physical examination, and supplementary examinations.

METHODS

The medical records of TBI patients who were hospitalized in two medical institutions between June 2015 and June 2021 were collected and analyzed. Patients were divided into the training set, validation set, and testing set. The possible predictive indicators were screened after analyzing the data of patients in the training set. Then prediction models were found based on the possible predictive indicators in the training set. Data of patients in the validation set and the testing set was provided to validate the predictive values of the models.

RESULTS

Age, Glasgow coma scale score, Apolipoprotein E genotype, damage area, serum C-reactive protein, and interleukin-8 (IL-8) levels, and Marshall computed tomography score were found associated with early prognosis of TBI patients. The accuracy of the early prognosis prediction model (EPPM) was 80%, and the sensitivity and specificity of the EPPM were 78.8% and 80.8% in the training set. The accuracy of the EPPM was 79%, and the sensitivity and specificity of the EPPM were 66.7% and 86.2% in the validation set. The accuracy of the early EPPM was 69.1%, and the sensitivity and specificity of the EPPM were 67.9% and 77.8% in the testing set.

CONCLUSION

Prediction models integrating general information, clinical manifestations, and auxiliary examination results may provide a reliable and rapid method to evaluate and predict the early prognosis of TBI patients.

Inflammatory Biomarkers of Traumatic Brain Injury

Traumatic brain injury (TBI) has a complex pathology in which the initial injury releases damage associated proteins that exacerbate the neuroinflammatory response during the chronic secondary injury period. One of the major pathological players in the inflammatory response after TBI is the inflammasome. Increased levels of inflammasome proteins during the acute phase after TBI are associated with worse functional outcomes. Previous studies reveal that the level of inflammasome proteins in biological fluids may be used as promising new biomarkers for the determination of TBI functional outcomes. In this study, we provide further evidence that inflammatory cytokines and inflammasome proteins in serum may be used to determine injury severity and predict pathological outcomes. In this study, we analyzed blood serum from TBI patients and respective controls utilizing Simple Plex inflammasome and V-PLEX inflammatory cytokine assays. We performed statistical analyses to determine which proteins were significantly elevated in TBI individuals. The receiver operating characteristics (ROC) were determined to obtain the area under the curve (AUC) to establish the potential fit as a biomarker. Potential biomarkers were then compared to documented patient Glasgow coma scale scores via a correlation matrix and a multivariate linear regression to determine how respective biomarkers are related to the injury severity and pathological outcome. Inflammasome proteins and inflammatory cytokines were elevated after TBI, and the apoptosis-associated speck like protein containing a caspase recruitment domain (ASC), interleukin (IL)-18, tumor necrosis factor (TNF)-α, IL-4 and IL-6 were the most reliable biomarkers. Additionally, levels of these proteins were correlated with known clinical indicators of pathological outcome, such as the Glasgow coma scale (GCS). Our results show that inflammatory cytokines and inflammasome proteins are promising biomarkers for determining pathological outcomes after TBI. Additionally, levels of biomarkers could potentially be utilized to determine a patient’s injury severity and subsequent pathological outcome. These findings show that inflammation-associated proteins in the blood are reliable biomarkers of injury severity that can also be used to assess the functional outcomes of TBI patients.

Nogo-A Is a Potential Prognostic Marker for Spinal Cord Injury

Objective

Spinal cord injury (SCI) has become prevalent worldwide in recent years, and its prognosis is poor and the pathological mechanism has not been fully elucidated. Nogo-A is one of the isoforms of the neurite outgrowth inhibitory protein reticulon 4. The purpose of this study was to determine whether Nogo-A could be used as a marker for predicting the prognosis of SCI.

Methods

We screened eligible SCI patients and controls based on inclusion and exclusion criteria. We also collected baseline clinical information and peripheral venous blood of the enrolled population. Participants' baseline serum Nogo-A levels were measured by enzyme-linked immunosorbent assay (ELISA). The American Spinal Injury Association (ASIA) scale was used to evaluate the prognosis of SCI patients after 3 months.

Results

Baseline clinical information (age; gender; smoking; drinking; SBP, systolic blood pressure; DBP, diastolic blood pressure; fasting blood glucose; WBC, white blood cells; CRP, C-reactive protein) of SCI patients and controls were not statistically significant academic differences (p > 0.05). The baseline serum Nogo-A levels of SCI patients and controls were 192.7 ± 13.9 ng/ml and 263.1 ± 22.4 ng/ml, respectively, and there was a statistically significant difference between the two groups (p < 0.05). We divided SCI patients into 4 groups according to their baseline serum Nogo-A quartile levels and analyzed their relationship with ASIA scores. The trend test results showed that with the increase of Nogo-A level, the ASIA sensation score and ASIA motor score were significantly decreased (p < 0.001). Multivariate regression analysis showed that serum Nogo-A levels remained a potential cause affecting the prognosis of SCI after adjusting for confounding factors in multiple models.

Conclusions

Serum Nogo-A levels were significantly elevated in SCI patients. Moreover, elevated Nogo-A levels often indicate poor prognosis and can be used as a marker to predict the prognosis of SCI.

Electrochemical sensing of blood proteins for mild traumatic brain injury (mTBI) diagnostics and prognostics: towards a point-of-care application

Traumatic Brain Injury (TBI) being one of the principal causes of death and acquired disability in the world imposes a large burden on the global economy. Mild TBI (mTBI) is particularly challenging to assess due to the frequent lack of well-pronounced post-injury symptoms. However, if left untreated mTBI (especially when repetitive) can lead to serious long-term implications such as cognitive and neuropathological disorders. Computer tomography and magnetic resonance imaging commonly used for TBI diagnostics require well-trained personnel, are costly, difficult to adapt for on-site measurements and are not always reliable in identifying small brain lesions. Thus, there is an increasing demand for sensitive point-of-care (POC) testing tools in order to aid mTBI diagnostics and prediction of long-term effects. Biomarker quantification in body fluids is a promising basis for POC measurements, even though establishing a clinically relevant mTBI biomarker panel remains a challenge. Actually, a minimally invasive, rapid and reliable multianalyte detection device would allow the efficient determination of injury biomarker release kinetics and thus support the preclinical evaluation and clinical validation of a proposed biomarker panel for future decentralized in vitro diagnostics. In this respect electrochemical biosensors have recently attracted great attention and the present article provides a critical study on the electrochemical protocols suggested in the literature for detection of mTBI-relevant protein biomarkers. The authors give an overview of the analytical approaches for transduction element functionalization, review recent technological advances and highlight the key challenges remaining in view of an eventual integration of the proposed concepts into POC diagnostic solutions.

Extracellular Neuroglobin as a Stress-Induced Factor Activating Pre-Adaptation Mechanisms against Oxidative Stress and Chemotherapy-Induced Cell Death in Breast Cancer

Components of tumor microenvironment, including tumor and/or stromal cells-derived factors, exert a critical role in breast cancer (BC) progression. Here we evaluated the possible role of neuroglobin (NGB), a monomeric globin that acts as a compensatory protein against oxidative and apoptotic processes, as part of BC microenvironment. The extracellular NGB levels were evaluated by immunofluorescence of BC tissue sections and by Western blot of the culture media of BC cell lines. Moreover, reactive oxygen species (ROS) generation, cell apoptosis, and cell migration were evaluated in different BC cells and non-tumorigenic epithelial mammary cells treated with BC cells (i.e., Michigan Cancer Foundation-7, MCF-7) conditioned culture media and extracellular NGB. Results demonstrate that NGB is a component of BC microenvironment. NGB is released in tumor microenvironment by BC cells only under oxidative stress conditions where it can act as autocrine/paracrine factor able to communicate cell resilience against oxidative stress and chemotherapeutic treatment.

Early stage neuroglobin level as a predictor of delayed cerebral ischemia in patients with aneurysmal subarachnoid hemorrhage

BACKGROUND

The neuroglobin (Ngb) is well recognized as a potential biomarker for the hypoxic-ischemic brain injury. However, connection between Ngb and delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage (aSAH) is still unclear.

OBJECTIVE

To investigate the relationship between early stage Ngb level of aSAH patient and the occurrence of DCI.

METHODS

We evaluated 126 aSAH patients who were enrolled into a prospective observational cohort study. Serum Ngb level on days 1, 2, 3, 5, and 7 after aSAH were determined using a commercial enzyme-linked immunosorbent assay kit. The relationship between Ngb level and DCI was analyzed.

RESULTS

Forty-six (36.5%) aSAH patients experienced DCI. Patients with DCI had significantly higher Ngb levels than those without (p < .001). Multivariate model analysis revealed that day 3 Ngb level remained a significant factor after adjusting for World Federation of Neurosurgical Societies (WFNS) grade, modified Fisher grade, clipping and Ngb levels on days 1, 2, 5, and 7. Sensitivity, specificity, and Youden index of day 3 Ngb level for identifying DCI were derived as 73.9%, 72.5%, and 0.46, respectively, based on the best threshold of 8.4 ng/ml. Regardless in good-grade group or in poor-grade group, patients having day 3 Ngb level > 8.4 ng/ml has a significantly worse DCI survival rate than those having day 3 Ngb level <=8.4 ng/ml (p = .026 and .009, respectively).

CONCLUSIONS

Serum Ngb level was significantly elevated in DCI patients. Early stage aSAH Ngb level has the potential of being used as a novel DCI occurrence predictor, especially when Ngb level was combined with WFNS grade.

Knockdown of RTN1-C attenuates traumatic neuronal injury through regulating intracellular Ca2+ homeostasis

Reticulons (RTNs) are a family of membrane-bound proteins that are dominantly localized to the endoplasmic reticulum (ER) membrane. RTN1-C is one member of RTNs abundantly expressed in the brain and has been shown to mediate neuronal injury in cerebral ischemia models. In the present study, we investigated the role of RTN1-C in an in vitro brain trauma model mimicked by traumatic neuronal injury (TNI) in primary cultured cortical neurons. TNI increased the expression of RTN1-C in cortical neurons but had no effect on RTN1-A and RTN1-B. Knockdown of RTN1-C with specific siRNA (Si-RTN1-C) significantly decreased cytotoxicity and apoptosis after TNI. The results of Ca²⁺ imaging showed that intracellular Ca²⁺ overload induced by TNI was attenuated by RTN1-C knockdown. Furthermore, the activation of metabotropic glutamate receptor 1 (mGluR1)-induced Ca²⁺ response was partially prevented by Si-RTN1-C transfection. We also evaluated the role of RTN1-C in store-operated Ca²⁺ entry (SOCE) in cortical neurons using the ER Ca²⁺ inducer thapsigargin (Tg). The results showed that knockdown of RTN1-C alleviated the SOCE-mediated Ca²⁺ influx and decreased the expression of stromal interactive molecule 1 (STIM1). In summary, the present study found that knockdown of RTN1-C protected neurons against TNI via preservation of intracellular Ca²⁺ homeostasis, which was associated with the inhibition of mGluR1-mediated ER Ca²⁺ release and suppression of STIM1-related SOCE. Thus, RTN1-C might represent a therapeutic target for traumatic brain injury (TBI) research.

The isoform A of reticulon-4 (Nogo-A) in cerebrospinal fluid of primary brain tumor patients: influencing factors

Background

The influence of isoform A of reticulon-4 (Nogo-A), also known as neurite outgrowth inhibitor, on primary brain tumor development was reported. Therefore the aim was the evaluation of Nogo-A concentrations in cerebrospinal fluid (CSF) and serum of brain tumor patients compared with non-tumoral individuals.

Results

All serum results, except for two cases, obtained both in brain tumors and non-tumoral individuals, were below the lower limit of ELISA detection. Cerebrospinal fluid Nogo-A concentrations were significantly lower in primary brain tumor patients compared to non-tumoral individuals. The univariate linear regression analysis found that if white blood cell count increases by 1 × 10³/μL, the mean cerebrospinal fluid Nogo-A concentration value decreases 1.12 times. In the model of multiple linear regression analysis predictor variables influencing cerebrospinal fluid Nogo-A concentrations included: diagnosis, sex, and sodium level. The mean cerebrospinal fluid Nogo-A concentration value was 1.9 times higher for women in comparison to men. In the astrocytic brain tumor group higher sodium level occurs with lower cerebrospinal fluid Nogo-A concentrations. We found the opposite situation in non-tumoral individuals.

Conclusions

Univariate linear regression analysis revealed, that cerebrospinal fluid Nogo-A concentrations change in relation to white blood cell count. In the created model of multiple linear regression analysis we found, that within predictor variables influencing CSF Nogo-A concentrations were diagnosis, sex, and sodium level. Results may be relevant to the search for cerebrospinal fluid biomarkers and potential therapeutic targets in primary brain tumor patients.

Materials and methods

Nogo-A concentrations were tested by means of enzyme-linked immunosorbent assay (ELISA).

Neuroglobin as a Novel Biomarker for Predicting Poor Outcomes in Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE

Neuroglobin (Ngb) has a high affinity for oxygen and helps prevent hypoxic-ischemic brain damage. In this study we analyzed the relationship between Ngb levels and clinical outcomes of aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

Serum Ngb levels were measured in 58 patients with aSAH and 27 control individuals using the enzyme-linked immunosorbent assay. To continuously assess aSAH, we measured serum Ngb levels on days 1, 2, 3, 5, and 7 after aSAH. Clinical data were collected using the Hunt and Hess Scale, the Glasgow Coma Scale (GCS), the World Federation of Neurological Surgeons (WFNS) Scale, and the modified Fisher Scale. Clinical outcomes included 6-month mortality and 6-month unfavorable outcomes (modified Rankin Scale (mRS) score of 3-6).

RESULTS

Serum Ngb levels increased after aSAH, peaked on day 2, and then gradually decreased. Serum Ngb levels on admission were higher in the patient group than in the control group (7.67 ± 2.56 ng/mL vs. 6.45 ± 0.88 ng/mL, P < 0.05). Multivariate logistic regression analysis indicated that serum Ngb levels on day 2 after aSAH were independently related to 6-month mortality (odds ratio [OR] = 0.265, 95% confidence interval [CI] = 0.094-0.747, P < 0.05) and 6-month unfavorable outcomes (OR = 1.919, 95% CI = 1.158-3.180, P < 0.05), and receiver operating characteristic curve analysis showed that serum Ngb levels on day 2 predicted 6-month mortality and 6-month unfavorable outcomes, with areas under the curve of 0.893 (P < 0.05; 95% CI, 0.812-0.974) and 0.818 (P < 0.05; 95% CI, 0.691-0.954), respectively, based on the best thresholds.

CONCLUSIONS

Serum Ngb levels on day 2 after aSAH were strongly associated with poor outcomes in aSAH, suggesting that Ngb may be a novel biomarker for predicting poor outcomes in aSAH.

Clinical significance of changes in serum neuroglobin and HIF-1α concentrations during the early-phase of acute ischemic stroke

BACKGROUND

Neuroglobin (NGB) has been described as a neuroprotective agent in cerebral ischemia, hypoxia inducible factor (HIF) has shown an important role in modulating hypoxic and ischemic injury, and therefore they have the potential to impact outcomes after acute ischemic stroke (AIS). Thus, we investigated early changes in the concentrations of serum NGB and HIF-1α after AIS and evaluated the relations of both NGB and HIF-1α to stroke severity and prognosis.

METHODS

We prospectively measured the serum concentrations of NGB and HIF-1α in 40 patients with AIS at 24, 48, 72, and 96h after stroke. Correlation combined with infarct size and National Institutes of Health Stroke Scale (NIHSS) score of the patients was analyzed. Receiver operating characteristic (ROC) curve was used to appraise their value in predicting the 90-day outcome after AIS.

RESULTS

Serum NGB concentrations increased and peaked at 72h after AIS, whereas serum concentrations of HIF-1α increased for 48h. Peak serum NGB concentration correlated significantly with both infarct size (R²=0.484, p<0.001) and admission NIHSS score (R²=0.578, p<0.001), while serum HIF-1α concentration was only correlated to a patient's infarct size (R²=0.394, p<0.001). ROC curve analysis suggested that the serum NGB concentration had a significantly better predictive power for poor outcome.

CONCLUSIONS

NGB level increased in serum after AIS accompanied by increases in serum HIF-1α, and was suggested as a predictor of stroke severity and poor prognosis.