scholarly journals Haemoglobin causes neuronal damage in vivo which is preventable by haptoglobin

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Patrick Garland ◽  
Matthew J Morton ◽  
William Haskins ◽  
Ardalan Zolnourian ◽  
Andrew Durnford ◽  
...  
Keyword(s):  
Subarachnoid Haemorrhage ◽  
Prolonged Exposure ◽  
Neuronal Damage ◽  
Clinical Importance ◽  
Large Vessel ◽  
Therapeutic Window ◽  
Neurofilament Light Chain ◽  
Neurofilament Light ◽  
The Brain

Abstract After subarachnoid haemorrhage, prolonged exposure to toxic extracellular haemoglobin occurs in the brain. Here, we investigate the role of haemoglobin neurotoxicity in vivo and its prevention. In humans after subarachnoid haemorrhage, haemoglobin in cerebrospinal fluid was associated with neurofilament light chain, a marker of neuronal damage. Most haemoglobin was not complexed with haptoglobin, an endogenous haemoglobin scavenger present at very low concentration in the brain. Exogenously added haptoglobin bound most uncomplexed haemoglobin, in the first 2 weeks after human subarachnoid haemorrhage, indicating a wide therapeutic window. In mice, the behavioural, vascular, cellular and molecular changes seen after human subarachnoid haemorrhage were recapitulated by modelling a single aspect of subarachnoid haemorrhage: prolonged intrathecal exposure to haemoglobin. Haemoglobin-induced behavioural deficits and astrocytic, microglial and synaptic changes were attenuated by haptoglobin. Haptoglobin treatment did not attenuate large-vessel vasospasm, yet improved clinical outcome by restricting diffusion of haemoglobin into the parenchyma and reducing small-vessel vasospasm. In summary, haemoglobin toxicity is of clinical importance and preventable by haptoglobin, independent of large-vessel vasospasm.

scholarly journals Characterization of Fluid Biomarkers Reveals Lysosome Dysfunction and Neurodegeneration in Neuronopathic MPS II Patients

2020 ◽  
Vol 21 (15) ◽  
pp. 5188 ◽  
Author(s):  
Akhil Bhalla ◽  
Ritesh Ravi ◽  
Meng Fang ◽  
Annie Arguello ◽  
Sonnet S. Davis ◽  
...  
Keyword(s):  
Neuronal Damage ◽  
Lysosomal Storage ◽  
Mucopolysaccharidosis Type Ii ◽  
Neurofilament Light Chain ◽  
Neurofilament Light ◽  
Mps Ii ◽  
Cellular Dysfunction ◽  
The Relationship ◽  
The Brain

Mucopolysaccharidosis type II is a lysosomal storage disorder caused by a deficiency of iduronate-2-sulfatase (IDS) and characterized by the accumulation of the primary storage substrate, glycosaminoglycans (GAGs). Understanding central nervous system (CNS) pathophysiology in neuronopathic MPS II (nMPS II) has been hindered by the lack of CNS biomarkers. Characterization of fluid biomarkers has been largely focused on evaluating GAGs in cerebrospinal fluid (CSF) and the periphery; however, GAG levels alone do not accurately reflect the broad cellular dysfunction in the brains of MPS II patients. We utilized a preclinical mouse model of MPS II, treated with a brain penetrant form of IDS (ETV:IDS) to establish the relationship between markers of primary storage and downstream pathway biomarkers in the brain and CSF. We extended the characterization of pathway and neurodegeneration biomarkers to nMPS II patient samples. In addition to the accumulation of CSF GAGs, nMPS II patients show elevated levels of lysosomal lipids, neurofilament light chain, and other biomarkers of neuronal damage and degeneration. Furthermore, we find that these biomarkers of downstream pathology are tightly correlated with heparan sulfate. Exploration of the responsiveness of not only CSF GAGs but also pathway and disease-relevant biomarkers during drug development will be crucial for monitoring disease progression, and the development of effective therapies for nMPS II.

scholarly journals DHEA Attenuates Microglial Activation via Induction of JMJD3 in Experimental Subarachnoid Haemorrhage

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Tao Tao ◽  
Guang-Jie Liu ◽  
Xuan Shi ◽  
Yan Zhou ◽  
Yue Lu ◽  
...  
Keyword(s):  
Subarachnoid Haemorrhage ◽  
Microglial Activation ◽  
Neuronal Damage ◽  
Neuroprotective Effect ◽  
Early Brain Injury ◽  
Protective Effects ◽  
In Vivo Models ◽  
The Brain

Abstract Background Microglia are resident immune cells in the central nervous system and central to the innate immune system. Excessive activation of microglia after subarachnoid haemorrhage (SAH) contributes greatly to early brain injury, which is responsible for poor outcomes. Dehydroepiandrosterone (DHEA), a steroid hormone enriched in the brain, has recently been found to regulate microglial activation. The purpose of this study was to address the role of DHEA in SAH. Methods We used in vivo models of endovascular perforation and in vitro models of haemoglobin exposure to illustrate the effects of DHEA on microglia in SAH. Results In experimental SAH mice, exogenous DHEA administration increased DHEA levels in the brain and modulated microglial activation. Ameliorated neuronal damage and improved neurological outcomes were also observed in the SAH mice pretreated with DHEA, suggesting neuronal protective effects of DHEA. In cultured microglia, DHEA elevated the mRNA and protein levels of Jumonji d3 (JMJD3, histone 3 demethylase) after haemoglobin exposure, downregulated the H3K27me3 level, and inhibited the transcription of proinflammatory genes. The devastating proinflammatory microglia-mediated effects on primary neurons were also attenuated by DHEA; however, specific inhibition of JMJD3 abolished the protective effects of DHEA. We next verified that DHEA-induced JMJD3 expression, at least in part, through the tropomyosin-related kinase A (TrkA)/Akt signalling pathway. Conclusions DHEA has a neuroprotective effect after SAH. Moreover, DHEA increases microglial JMJD3 expression to regulate proinflammatory/anti-inflammatory microglial activation after haemoglobin exposure, thereby suppressing inflammation.

scholarly journals No evidence of neuronal damage as measured by neurofilament light chain in a HIV cure study utilising a kick-and-kill approach

2021 ◽  
pp. 100056
Author(s):  
Jasmini ALAGARATNAM ◽  
Wolfgang STÖHR ◽  
Jamie TOOMBS ◽  
Amanda HESLEGRAVE ◽  
Henrik ZETTERBERG ◽  
...  
Keyword(s):  
Light Chain ◽  
Neuronal Damage ◽  
Hiv Cure ◽  
Neurofilament Light Chain ◽  
Neurofilament Light

scholarly journals Evaluation of neurofilament light chain in the cerebrospinal fluid and blood as a biomarker for neuronal damage in experimental pneumococcal meningitis

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Ngoc Dung Le ◽  
Lukas Muri ◽  
Denis Grandgirard ◽  
Jens Kuhle ◽  
David Leppert ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Single Molecule ◽  
Light Chain ◽  
Pneumococcal Meningitis ◽  
Neuronal Damage ◽  
Neuronal Injury ◽  
Health Concern ◽  
Neurofilament Light Chain ◽  
Neurofilament Light ◽  
Inflammatory Phase

Abstract Background Pneumococcal meningitis (PM) remains a global public health concern and affects all age groups. If acquired during infancy or childhood, permanent neurofunctional deficits including cognitive impairment, cerebral palsy, and secondary epilepsy are typical sequelae of neuronal injury. Determination of patients at risk for the development of brain injury and subsequent neurofunctional sequelae could help to identify patients for focused management. Neurofilament light chain (NfL) is an axonal cytoskeletal protein released upon neuronal injury into the cerebrospinal fluid (CSF) and blood. As little is known about the course of neurofilament release in the course of PM, we measured CSF and serum NfL levels longitudinally in experimental PM (ePM). Methods Eleven-day-old infant Wistar rats were infected intracisternally with Streptococcus pneumoniae and treated with ceftriaxone. At 18 and 42 h post-infection (hpi), the blood and CSF were sampled for NfL measurements by a single molecule array technology. Inflammatory cytokines and MMP-9 in CSF were quantified by magnetic bead multiplex assay (Luminex®) and by gel zymography, respectively. Results In ePM, CSF and serum NfL levels started to increase at 18 hpi and were 26- and 3.5-fold increased, respectively, compared to mock-infected animals at 42 hpi (p < 0.0001). CSF and serum NfL correlated at 18 hpi (p < 0.05, r = 0.4716) and 42 hpi (p < 0.0001, r = 0.8179). Both CSF and serum NfL at 42 hpi strongly correlated with CSF levels of IL-1β, TNF-α, and IL-6 and of MMP-9 depending on their individual kinetics. Conclusion Current results demonstrate that during the peak inflammatory phase of ePM, NfL levels in CSF and serum are the highest among CNS disease models studied so far. Given the strong correlation of CSF versus serum NfL, and its CNS-specific signal character, longitudinal measurements to monitor the course of PM could be performed based on blood sample tests, i.e., without the need of repetitive spinal taps. We conclude that NfL in the serum should be evaluated as a biomarker in PM.

scholarly journals Systemic Antibacterial Activity of Novel Synthetic Cyclic Peptides

2005 ◽  
Vol 49 (8) ◽  
pp. 3302-3310 ◽  
Author(s):  
Véronique Dartois ◽  
Jorge Sanchez-Quesada ◽  
Edelmira Cabezas ◽  
Ellen Chi ◽  
Chad Dubbelde ◽  
...  
Keyword(s):  
Cyclic Peptides ◽  
Prolonged Exposure ◽  
Cyclic Peptide ◽  
Present Report ◽  
Bacterial Load ◽  
Pharmacokinetic Profile ◽  
Therapeutic Window ◽  
Infection Model

ABSTRACT Cyclic peptides with an even number of alternating d,l-α-amino acid residues are known to self-assemble into organic nanotubes. Such peptides previously have been shown to be stable upon protease treatment, membrane active, and bactericidal and to exert antimicrobial activity against Staphylococcus aureus and other gram-positive bacteria. The present report describes the in vitro and in vivo pharmacology of selected members of this cyclic peptide family. The intravenous (i.v.) efficacy of six compounds with MICs of less than 12 μg/ml was tested in peritonitis and neutropenic-mouse thigh infection models. Four of the six peptides were efficacious in vivo, with 50% effective doses in the peritonitis model ranging between 4.0 and 6.7 mg/kg against methicillin-sensitive S. aureus (MSSA). In the thigh infection model, the four peptides reduced the bacterial load 2.1 to 3.0 log units following administration of an 8-mg/kg i.v. dose. Activity against methicillin-resistant S. aureus was similar to MSSA. The murine pharmacokinetic profile of each compound was determined following i.v. bolus injection. Interestingly, those compounds with poor efficacy in vivo displayed a significantly lower maximum concentration of the drug in serum and a higher volume of distribution at steady state than compounds with good therapeutic properties. S. aureus was unable to easily develop spontaneous resistance upon prolonged exposure to the peptides at sublethal concentrations, in agreement with the proposed interaction with multiple components of the bacterial membrane canopy. Although additional structure-activity relationship studies are required to improve the therapeutic window of this class of antimicrobial peptides, our results suggest that these amphipathic cyclic d,l-α-peptides have potential for systemic administration and treatment of otherwise antibiotic-resistant infections.

scholarly journals Plasma neurofilament light chain protein is not increased in treatment-resistant schizophrenia and first-degree relatives

2021 ◽  
pp. 000486742110586
Author(s):  
Dhamidhu Eratne ◽  
Shorena Janelidze ◽  
Charles B Malpas ◽  
Samantha Loi ◽  
Mark Walterfang ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Light Chain ◽  
Neurodegenerative Disorders ◽  
Neuronal Damage ◽  
First Episode ◽  
Treatment Resistant ◽  
Neurofilament Light Chain ◽  
Neurofilament Light ◽  
First Degree Relatives ◽  
Frontotemporal Dementias

Objective: Schizophrenia, a complex psychiatric disorder, is often associated with cognitive, neurological and neuroimaging abnormalities. The processes underlying these abnormalities, and whether a subset of people with schizophrenia have a neuroprogressive or neurodegenerative component to schizophrenia, remain largely unknown. Examining fluid biomarkers of diverse types of neuronal damage could increase our understanding of these processes, as well as potentially provide clinically useful biomarkers, for example with assisting with differentiation from progressive neurodegenerative disorders such as Alzheimer and frontotemporal dementias. Methods: This study measured plasma neurofilament light chain protein (NfL) using ultrasensitive Simoa technology, to investigate the degree of neuronal injury in a well-characterised cohort of people with treatment-resistant schizophrenia on clozapine ( n = 82), compared to first-degree relatives (an at-risk group, n = 37), people with schizophrenia not treated with clozapine ( n = 13), and age- and sex-matched controls ( n = 59). Results: We found no differences in NfL levels between treatment-resistant schizophrenia (mean NfL, M = 6.3 pg/mL, 95% confidence interval: [5.5, 7.2]), first-degree relatives (siblings, M = 6.7 pg/mL, 95% confidence interval: [5.2, 8.2]; parents, M after adjusting for age = 6.7 pg/mL, 95% confidence interval: [4.7, 8.8]), controls (M = 5.8 pg/mL, 95% confidence interval: [5.3, 6.3]) and not treated with clozapine (M = 4.9 pg/mL, 95% confidence interval: [4.0, 5.8]). Exploratory, hypothesis-generating analyses found weak correlations in treatment-resistant schizophrenia, between NfL and clozapine levels (Spearman’s r = 0.258, 95% confidence interval: [0.034, 0.457]), dyslipidaemia ( r = 0.280, 95% confidence interval: [0.064, 0.470]) and a negative correlation with weight ( r = −0.305, 95% confidence interval: [−0.504, −0.076]). Conclusion: Treatment-resistant schizophrenia does not appear to be associated with neuronal, particularly axonal degeneration. Further studies are warranted to investigate the utility of NfL to differentiate treatment-resistant schizophrenia from neurodegenerative disorders such as behavioural variant frontotemporal dementia, and to explore NfL in other stages of schizophrenia such as the prodome and first episode.

scholarly journals High frequency of cerebrospinal fluid autoantibodies in COVID-19 patients with neurological symptoms

2020 ◽  
Author(s):  
Christiana Franke ◽  
Caroline Ferse ◽  
Jakob Kreye ◽  
S Momsen Reincke ◽  
Elisa Sanchez-Sendin ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
High Frequency ◽  
Clinical Symptoms ◽  
Epileptic Seizures ◽  
Neurological Symptoms ◽  
Neurofilament Light Chain ◽  
Neurofilament Light ◽  
Intensive Care Patients ◽  
Neuronal Autoantibodies ◽  
The Brain

AbstractCOVID-19 intensive care patients occasionally develop neurological symptoms. The absence of SARS-CoV-2 in most cerebrospinal fluid (CSF) samples suggests the involvement of further mechanisms including autoimmunity. We therefore determined whether anti-neuronal or anti-glial autoantibodies are present in eleven consecutive severely ill COVID-19 patients presenting with unexplained neurological symptoms. These included myoclonus, cranial nerve involvement, oculomotor disturbance, delirium, dystonia and epileptic seizures. Most patients showed signs of CSF inflammation and increased levels of neurofilament light chain. All patients had anti-neuronal autoantibodies in serum or CSF when assessing a large panel of autoantibodies against intracellular and surface antigens relevant for central nervous system diseases using cell-based assays and indirect immunofluorescence on murine brain sections. Antigens included proteins well-established in clinical routine, such as Yo or NMDA receptor, but also a variety of specific undetermined epitopes on brain sections. These included vessel endothelium, astrocytic proteins and neuropil of basal ganglia, hippocampus or olfactory bulb. The high frequency of autoantibodies targeting the brain in the absence of other explanations suggests a causal relationship to clinical symptoms, in particular to hyperexcitability (myoclonus, seizures). While several underlying autoantigens still await identification in future studies, presence of autoantibodies may explain some aspects of multi-organ disease in COVID-19 and can guide immunotherapy in selected cases.

scholarly journals Plasma Neurofilament Light Chain Predicts Cognitive Progression in Prodromal and Clinical Dementia with Lewy Bodies

2021 ◽  
pp. 1-7
Author(s):  
Andrea Pilotto ◽  
Alberto Imarisio ◽  
Claudia Carrarini ◽  
Mirella Russo ◽  
Stefano Masciocchi ◽  
...  
Keyword(s):  
Light Chain ◽  
Neurological Disorders ◽  
Dementia With Lewy Bodies ◽  
Neuronal Damage ◽  
Lewy Bodies ◽  
Neurofilament Light Chain ◽  
Neurofilament Light ◽  
Predict Disease Progression

Plasma neurofilament light chain (NfL) is a marker of neuronal damage in different neurological disorders and might predict disease progression in dementia with Lewy bodies (DLB). The study enrolled 45 controls and 44 DLB patients (including 17 prodromal cases) who underwent an extensive assessment at baseline and at 2 years follow-up. At baseline, plasma NfL levels were higher in both probable DLB and prodromal cases compared to controls. Plasma NfL emerged as the best predictor of cognitive decline compared to age, sex, and baseline severity variables. The study supports the role of plasma NfL as a useful prognostic biomarker from the early stages of DLB.

scholarly journals Neuroimaging Biomarkers of Experimental Epileptogenesis and Refractory Epilepsy

2019 ◽  
Vol 20 (1) ◽  
pp. 220 ◽  
Author(s):  
Sandesh Reddy ◽  
Iyan Younus ◽  
Vidya Sridhar ◽  
Doodipala Reddy
Keyword(s):  
Animal Models ◽  
Refractory Epilepsy ◽  
Single Photon ◽  
Neuronal Damage ◽  
Photon Emission ◽  
Brain Magnetic Resonance Imaging ◽  
Functional Changes ◽  
Neuroimaging Biomarkers ◽  
The Brain

This article provides an overview of neuroimaging biomarkers in experimental epileptogenesis and refractory epilepsy. Neuroimaging represents a gold standard and clinically translatable technique to identify neuropathological changes in epileptogenesis and longitudinally monitor its progression after a precipitating injury. Neuroimaging studies, along with molecular studies from animal models, have greatly improved our understanding of the neuropathology of epilepsy, such as the hallmark hippocampus sclerosis. Animal models are effective for differentiating the different stages of epileptogenesis. Neuroimaging in experimental epilepsy provides unique information about anatomic, functional, and metabolic alterations linked to epileptogenesis. Recently, several in vivo biomarkers for epileptogenesis have been investigated for characterizing neuronal loss, inflammation, blood-brain barrier alterations, changes in neurotransmitter density, neurovascular coupling, cerebral blood flow and volume, network connectivity, and metabolic activity in the brain. Magnetic resonance imaging (MRI) is a sensitive method for detecting structural and functional changes in the brain, especially to identify region-specific neuronal damage patterns in epilepsy. Positron emission tomography (PET) and single-photon emission computerized tomography are helpful to elucidate key functional alterations, especially in areas of brain metabolism and molecular patterns, and can help monitor pathology of epileptic disorders. Multimodal procedures such as PET-MRI integrated systems are desired for refractory epilepsy. Validated biomarkers are warranted for early identification of people at risk for epilepsy and monitoring of the progression of medical interventions.

scholarly journals Serum neurofilament light protein correlates with unfavorable clinical outcomes in hospitalized patients with COVID-19

2021 ◽  
pp. eabi7643
Author(s):  
Mercedes Prudencio ◽  
Young Erben ◽  
Christopher P. Marquez ◽  
Karen R. Jansen-West ◽  
Camila Franco-Mesa ◽  
...  
Keyword(s):  
Clinical Outcomes ◽  
Neuronal Damage ◽  
Hospitalized Patients ◽  
Serum Concentrations ◽  
Imaging Studies ◽  
Neurofilament Light Chain ◽  
Neurofilament Light ◽  
Show Evidence ◽  
Posterior Reversible Leukoencephalopathy

Brain imaging studies of patients with COVID-19 show evidence of macro- and micro-hemorrhagic lesions, multifocal white matter hyperintensities, and lesions consistent with posterior reversible leukoencephalopathy. Imaging studies, however, are subject to selection bias and prospective studies are challenging to scale. Here, we evaluated whether serum neurofilament light chain (NFL), a neuroaxonal injury marker, could predict the extent of neuronal damage in a cohort of 142 hospitalized patients with COVID-19. NFL was elevated in the serum of patients with COVID-19 compared to healthy controls, including those without overt neurological manifestations. Higher NFL serum concentrations were associated with worse clinical outcomes. In one hundred hospitalized patients with COVID-19 treated with remdesivir, a trend toward lower NFL serum concentrations was observed. These data suggest that patients with COVID-19 may experience neuroaxonal injury and may be at risk for long-term neurological sequelae. Neuroaxonal injury should be considered as an outcome in acute pharmacotherapeutic trials for COVID-19.

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