ABSTRACT
BACKGROUND: Synapse degeneration is an early event in pathological frontotemporal lobar degeneration (FTLD). Consequently, a surrogate marker of synapse loss could be used to monitor early pathologic changes in patients with underlying FTLD. The aim of this study was to evaluate the relationship of antemortem cerebrospinal fluid (CSF) levels of 8 synaptic proteins with postmortem global tau and TDP-43 burden and cognitive performance and to assess their diagnostic capacity in a neuropathological FTLD cohort. METHODS: We included patients with a neuropathological confirmation of FTLD-Tau (n = 24, mean age-at-CSF 67 years ± 11), FTLD-TDP (n = 25, 66 years ± 9) or AD (n = 25, 73 years ± 6) as well as cognitively normal controls (n = 35, 69 years ± 7) from the Penn FTD Center and ADRC. We used a semi-quantitative measure of tau and TDP-43 inclusions to quantify pathological burden across 16 brain regions. Statistical methods included Spearman rank correlations, one-way analysis of covariance, ordinal regression, step-wise multiple linear regression and receiver-operating characteristic curves. RESULT: CSF calsyntenin-1 and neurexin-2a were correlated in all patient groups (rs = .55 to .88). In FTLD-TDP, we observed low antemortem CSF levels of calsyntenin-1 and neurexin-2a compared to AD (.72-fold, p = .001, .77-fold, p = .04, respectively) and controls (.80-fold, p = .02, .78-fold, p = .02, respectively), which were inversely associated with post-mortem global TDP-43 burden (regression r2 = .56, p = .007 and r2 = .57, p = .006, respectively). A multimarker panel including calsyntenin-1 was associated with TDP-43 burden (r2 = .69, p = .003) and MMSE score (r2 = .19, p = .03) in FTLD. A second multimarker synaptic panel, also including calsyntenin-1, was associated with MMSE score in FTLD-tau (r2 = .49, p = .04) and improved diagnostic performance to discriminate FTLD-Tau and FTLD-TDP neuropathologic subtypes (AUC = .83). CONCLUSION: These synaptic panels have potential in the differential diagnosis of FTLD neuropathologic subtypes and as surrogate markers of cognitive performance in future clinical trials targeting TDP-43 or tau.
Subject(s)
DNA-Binding Proteins , Frontotemporal Dementia , Frontotemporal Lobar Degeneration , tau Proteins , Aged , Biomarkers/cerebrospinal fluid , Cognition , DNA-Binding Proteins/cerebrospinal fluid , Frontotemporal Lobar Degeneration/pathology , Humans , Middle Aged , tau Proteins/cerebrospinal fluidABSTRACT
Various proteins play a decisive role in the pathology of different neurodegenerative diseases. Nonetheless, most of these proteins can only be detected during a neuropathological assessment, although some non-specific biomarkers are routinely tested for in the cerebrospinal fluid (CSF) as a part of the differential diagnosis of dementia. In antemortem CSF samples from 117 patients with different types of neuropathologically confirmed neurodegenerative disease with dementia, we assessed total-tau (t-tau), phosphorylated-tau (181P) (p-tau), amyloid-beta (1-42) (Aß42), TAR DNA binding protein (TDP)-43, progranulin (PGRN), and neurofilament light (NfL) chain levels, and positivity of protein 14-3-3. We found t-tau levels and the t-tau/p-tau ratios were significantly higher in prion diseases compared to the other neurodegenerative diseases. Statistically significant differences in the t-tau/Aß42 ratio predominantly corresponded to t-tau levels in prion diseases and Aß42 levels in AD. TDP-43 levels were significantly lower in prion diseases. Additionally, the TDP-43/Aß42 ratio was better able to distinguish Alzheimer's disease from other neurodegenerative diseases compared to using Aß42 alone. In frontotemporal lobar degeneration, PRGN levels were significantly higher in comparison to other neurodegenerative diseases. There is an increasing need for biomarkers suitable for diagnostic workups for neurodegenerative diseases. It appears that adding TDP-43 and PGRN to the testing panel for neurodegenerative diseases could improve the resolution of differential diagnoses.
Subject(s)
Biomarkers/cerebrospinal fluid , Cerebrospinal Fluid Proteins/cerebrospinal fluid , Dementia/diagnosis , 14-3-3 Proteins/cerebrospinal fluid , Aged , Aged, 80 and over , Amyloid beta-Peptides/cerebrospinal fluid , Autopsy , DNA-Binding Proteins/cerebrospinal fluid , Dementia/cerebrospinal fluid , Dementia/classification , Diagnosis, Differential , Female , Gene Expression Regulation , Humans , Male , Middle Aged , Neurofilament Proteins/cerebrospinal fluid , Peptide Fragments/cerebrospinal fluid , Progranulins/cerebrospinal fluid , Retrospective Studies , Sensitivity and Specificity , tau Proteins/cerebrospinal fluidABSTRACT
BACKGROUND: TAR DNA-binding protein-43 (TDP-43) and neurofilament light chain (NfL) are promising fluid biomarkers of disease progression for various dementia. OBJECTIVE: We would explore whether blood levels of NfL and TDP-43 could predict the long-term progression to dementia, and the relationship of TDP-43 levels between cerebrospinal fluid (CSF) and blood. METHODS: A total of 86 non-dementia elderly received 7-year follow-up, and were divided into 49 stable normal control (NC)/mild cognitive impairment (MCI) subjects, 19 subjects progressing from NC to MCI, and 18 subjects progressing from NC/MCI to dementia. Blood TDP-43 and NfL levels, and cognitive functions were measured in all subjects. Furthermore, another cohort of 23 dementia patients, including 13 AD and 10 non-AD patients received blood and CSF measurements of TDP-43. RESULTS: In cohort 1, compared to stable NC/MCI group, there were higher levels of blood TDP-43 at baseline in subjects progressing from NC/MCI to dementia. The combination of baseline blood TDP-43 levels with demographics including age, education, and diabetes had the detection for dementia occurrence. Baseline blood levels of NfL are negatively associated with cognitive function at 7-year follow-up. In cohort 2, we found there were no relationship between CSF and blood levels of TDP-43. Moreover, the levels of TDP-43 in CSF was positively associated with the age of patients, especially in AD group. CONCLUSION: Single blood TDP-43 could not estimate dementia occurrence; however, TDP-43 combined with demographics has the predictive effect for dementia occurrence and NfL level is associated with a decrease of cognitive function.
Subject(s)
Alzheimer Disease/blood , Cognitive Dysfunction/blood , DNA-Binding Proteins/blood , Age Factors , Aged , Aged, 80 and over , Alzheimer Disease/cerebrospinal fluid , Alzheimer Disease/epidemiology , Alzheimer Disease/physiopathology , Amyloid beta-Peptides/cerebrospinal fluid , Case-Control Studies , Cognitive Dysfunction/cerebrospinal fluid , Cognitive Dysfunction/epidemiology , Cognitive Dysfunction/physiopathology , DNA-Binding Proteins/cerebrospinal fluid , Dementia/blood , Dementia/cerebrospinal fluid , Dementia/epidemiology , Dementia/physiopathology , Disease Progression , Educational Status , Female , Humans , Independent Living , Male , Middle Aged , Neurofilament Proteins/blood , Peptide Fragments/cerebrospinal fluid , Phosphorylation , Risk Assessment , tau Proteins/cerebrospinal fluidABSTRACT
Pathologic alterations of Transactivation response DNA-binding protein 43 kilo Dalton (TDP-43) are a major hallmark of amyotrophic lateral sclerosis (ALS). In this pilot study, we analyzed the secondary structure distribution of TDP-43 in cerebrospinal fluid of ALS patients (n = 36) compared to Parkinson´s disease patients (PD; n = 30) and further controls (Ctrl; n = 24) using the immuno-infrared sensor technology. ALS patients could be discriminated from PD and Ctrl with a sensitivity/specificity of 89 %/77 % and 89 %/83 %, respectively. Our findings demonstrate that TDP-43 misfolding measured by the immuno-infrared sensor technology has the potential to serve as a biomarker candidate for ALS.
Subject(s)
Amyotrophic Lateral Sclerosis/cerebrospinal fluid , Amyotrophic Lateral Sclerosis/diagnosis , Biomarkers/cerebrospinal fluid , DNA-Binding Proteins/cerebrospinal fluid , Aged , DNA-Binding Proteins/chemistry , Female , Humans , Male , Middle Aged , Pilot Projects , Protein Structure, Secondary , Sensitivity and Specificity , Spectrophotometry, Infrared/methodsABSTRACT
INTRODUCTION: Evidence-based information about cerebrospinal fluid (CSF) levels of biomarkers in patients with amyotrophic lateral sclerosis (ALS) is limited. METHODS: Vascular endothelial growth factor (VEGF) and its receptor vascular endothelial growth factor receptor 2 (VEGFR2), optineurin (OPTN), monocyte chemoattractant protein-1 (MCP-1), angiogenin (ANG), and TAR DNA-binding protein (TDP-43) were quantified by enzyme-linked immunoassay in the CSF of 54 patients with sporadic ALS and 32 controls in a case-control study design. RESULTS: CSF levels of VEGF (P = .014) and ANG (P = .009) were decreased, whereas VEGFR2 was higher (P = .002) in patients with ALS than in controls. TDP-43 positively correlated with MCP-1 (P = .003), VEGF (P < .001), and VEGFR2 (P < .001) in patients with ALS. DISCUSSION: Our findings suggest possible utility of VEGF, VEGFR2, and ANG as biomarkers for use in ALS treatment trials.
Subject(s)
Amyotrophic Lateral Sclerosis/diagnosis , Cell Cycle Proteins/cerebrospinal fluid , Chemokine CCL2/cerebrospinal fluid , DNA-Binding Proteins/cerebrospinal fluid , Membrane Transport Proteins/cerebrospinal fluid , Ribonuclease, Pancreatic/cerebrospinal fluid , Vascular Endothelial Growth Factor A/cerebrospinal fluid , Vascular Endothelial Growth Factor Receptor-2/cerebrospinal fluid , Adult , Amyotrophic Lateral Sclerosis/cerebrospinal fluid , Biomarkers/cerebrospinal fluid , Case-Control Studies , Female , Humans , India , Male , Middle AgedABSTRACT
Only a few types of inflammasomes have been described in central nervous system cells. Among these, the absent in melanoma 2 (AIM2) inflammasome is primarily found in neurons, is highly specific and can be activated only by double-stranded DNA. Although it has been demonstrated that the AIM2 inflammasome is activated by poly(deoxyadenylic-deoxythymidylic) acid sodium salt and leads to pyroptotic neuronal cell death, the role of AIM2 inflammasome-mediated pyroptosis in early brain injury (EBI) after subarachnoid haemorrhage (SAH) has rarely been studied. Thus, we designed this study to explore the mechanism of gasdermin D(GSDMD)-induced pyroptosis mediated by the AIM2 inflammasome in EBI after SAH. The level of AIM2 from the cerebrospinal fluid (CSF) of patients with SAH was detected. The pathway of AIM2 inflammasome-mediated pyroptosis, the AIM2/Caspase-1/GSDMD pathway, was explored after experimental SAH in vivo and in primary cortical neurons stimulated by oxyhaemoglobin (oxyHb) in vitro. Then, we evaluated GSDMD-induced pyroptosis mediated by the AIM2 inflammasome in AIM2 and caspase-1- deficient mice and primary cortical neurons generated through lentivirus (LV) knockdown. Compared with that of the control samples, the AIM2 level in the CSF of the patients with SAH was significantly increased. Pyroptosis-associated proteins mediated by the AIM2 inflammasome were significantly increased in vivo and in vitro following experimentally induced SAH. After AIM2 and caspase-1 were knocked down by an LV, GSDMD-induced pyroptosis mediated by the AIM2 inflammasome was alleviated in EBI after SAH. Intriguingly, when caspase-1 was knocked down, apoptosis was significantly suppressed via impeding the activation of caspase-3. GSDMD-induced pyroptosis mediated by the AIM2 inflammasome may be involved in EBI following SAH. The inhibition of AIM2 inflammasome activation caused by knocking down AIM2 and caspase-1 alleviates GSDMD-induced pyroptosis in EBI after SAH.
Subject(s)
Brain Injuries/metabolism , DNA-Binding Proteins/cerebrospinal fluid , Inflammasomes/metabolism , Intracellular Signaling Peptides and Proteins/metabolism , Neurons/metabolism , Phosphate-Binding Proteins/metabolism , Pyroptosis/genetics , Subarachnoid Hemorrhage/metabolism , Animals , Brain Injuries/genetics , Caspase 1/genetics , Caspase 1/metabolism , Caspase 3/metabolism , Cells, Cultured , DNA-Binding Proteins/metabolism , Humans , Intracellular Signaling Peptides and Proteins/genetics , Mice , Mice, Inbred C57BL , Microscopy, Electron, Scanning , Neurons/ultrastructure , Phosphate-Binding Proteins/genetics , Pyroptosis/physiology , Subarachnoid Hemorrhage/geneticsABSTRACT
OBJECTIVE: To determine the diagnostic and prognostic significance of neurofilament light chain (NfL), TAR DNA-binding protein 43 (TDP-43), and total tau (t-tau) in cerebrospinal fluid (CSF) and plasma of patients with amyotrophic lateral sclerosis (ALS) and to investigate whether the combined use of those biomarker candidates can improve their diagnostic performance. METHODS: This was a single-center, prospective, longitudinal study. CSF and plasma samples were collected at the time of enrollment from a discovery cohort of 29 patients with ALS and 29 age-matched controls without neurodegenerative disease. In a validation cohort, there were 46 patients with ALS, and 46 control (not age-matched) patients with motor weakness resulting from neuromuscular diseases. NfL, TDP-43, and t-tau levels in CSF and plasma were measured using ultrasensitive single molecule assay (Simoa) technology. RESULTS: The following findings were reproducibly observed among the discovery and validation cohorts: increased levels of CSF NfL, plasma NfL, and CSF TDP-43 in ALS compared with control groups; shorter survival associated with higher levels of CSF and plasma NfL. When the CSF NfL and CSF TDP-43 levels were combined, the areas under the ROC curves (AUC) were slightly improved relative to AUCs for each biomarker alone. INTERPRETATION: CSF and plasma NfL may not only serve as diagnostic biomarkers but also provide a measure of disease progression. CSF TDP-43 is also useful as a diagnostic biomarker of ALS, but has no prognostic value. The combined use of CSF NfL and CSF TDP-43 may be a useful biomarker for the diagnosis of ALS.
Subject(s)
Amyotrophic Lateral Sclerosis/cerebrospinal fluid , Amyotrophic Lateral Sclerosis/diagnosis , DNA-Binding Proteins/cerebrospinal fluid , Neurofilament Proteins/cerebrospinal fluid , Aged , Amyotrophic Lateral Sclerosis/blood , Female , Humans , Longitudinal Studies , Male , Middle AgedABSTRACT
OBJECTIVES: The combination of high YKL-40 (a glial inflammatory marker) and low sAPPß (a soluble ß fragment of amyloid precursor protein) in cerebrospinal fluid (CSF) has been associated with frontotemporal lobar degeneration (FTLD) in clinical series. We investigate these biomarkers in a neuropathologically confirmed cohort of patients with FTLD. METHODS: CSF samples were selected from the Penn FTD Center (University of Pennsylvania). Participants were followed to autopsy and had a neuropathological diagnosis of FTLD-Tau (n=24), transactive response DNA-binding protein with 43 kDa (FTLD-TDP) (n=25) or Alzheimer's disease (AD, n=97). We compared levels of YKL-40 and sAPPß between groups and with cognitively normal controls (n=77), and assessed their diagnostic utility using receiver operating characteristic curves. We also investigated the effect of AD copathology and the correlation between these CSF markers and tau burden at autopsy. RESULTS: Both FTLD groups had lower levels of sAPPß, higher levels of YKL-40 and lower sAPPß:YKL-40 ratio in CSF compared with controls. The group of pure FTLD-Tau (without AD copathology) showed higher levels of YKL-40 than AD and than pure FTLD-TDP. YKL-40 levels correlated with pathological tau burden. The sAPPß:YKL-40 ratio had an area under the curve (AUC) of 0.91 (95% CI 0.86 to 0.96) to distinguish subjects with FTLD from controls, but lower values to distinguish FTLD from AD (AUC 0.70; 95% CI 0.61 to 0.79) and to discriminate FTLD-Tau from FTLD-TDP (AUC 0.67; 95% CI 0.51 to 0.82). CONCLUSIONS: Our study provides pathological confirmation that the combination of low sAPPß and high YKL-40 in CSF is associated with FTLD. These biomarkers could be useful in particular clinical settings when FTLD is suspected.
Subject(s)
Amyloid beta-Peptides/cerebrospinal fluid , Chitinase-3-Like Protein 1/cerebrospinal fluid , Frontotemporal Lobar Degeneration/cerebrospinal fluid , Frontotemporal Lobar Degeneration/pathology , Aged , Aged, 80 and over , Alzheimer Disease/cerebrospinal fluid , Biomarkers/cerebrospinal fluid , Case-Control Studies , Cohort Studies , DNA-Binding Proteins/cerebrospinal fluid , Female , Humans , Male , Middle Aged , Sensitivity and Specificity , tau Proteins/cerebrospinal fluidABSTRACT
Neurodegenerative dementias constitute a broad group of diseases in which abnormally folded proteins accumulate in specific brain regions and result in tissue reactions that eventually cause neuronal dysfunction and degeneration. Depending on where in the brain this happens, symptoms appear which may be used to classify the disorders on clinical grounds. However, brain changes in neurodegenerative dementias start to accumulate many years prior to symptom onset and there is a poor correlation between the clinical picture and what pathology that is the most likely to cause it. Thus, novel drug candidates having disease-modifying effects that is targeting the underlying pathology and changes the course of the disease needs to be defined using objective biomarker-based measures since the clinical symptoms are often non-specific and overlap between different disorders. Furthermore, the treatment should ideally be initiated as soon as symptoms are evident or when biomarkers confirm an underlying pathology (pre-clinical phase of the disease) to reduce irreversible damage to, for example, neurons, synapses and axons. Clinical trials in the pre-clinical phase bring a greater importance to biomarkers since by definition the clinical effects are difficult or slow to discern in a population that is not yet clinically affected. Here, we discuss neuropathological changes that may underlie neurodegenerative dementias, including how they can be detected and quantified using currently available biofluid-based biomarkers and how more of them could be identified using targeted proteomics approaches. This article is part of the special issue "Proteomics".
Subject(s)
Dementia , Neurodegenerative Diseases , Proteomics/methods , Amyloid beta-Peptides/blood , Amyloid beta-Peptides/cerebrospinal fluid , Biomarkers/blood , Biomarkers/cerebrospinal fluid , DNA-Binding Proteins/blood , DNA-Binding Proteins/cerebrospinal fluid , Dementia/metabolism , Dementia/pathology , Dementia/physiopathology , Humans , Neurodegenerative Diseases/metabolism , Neurodegenerative Diseases/pathology , Neurodegenerative Diseases/physiopathology , alpha-Synuclein/blood , alpha-Synuclein/cerebrospinal fluid , tau Proteins/blood , tau Proteins/cerebrospinal fluidABSTRACT
BACKGROUND: Frontotemporal dementia (FTD) and Amyotrophic Lateral Sclerosis (ALS) are incurable, progressive and fatal neurodegenerative diseases with patients variably affected clinically by motor, behavior, and cognitive deficits. The accumulation of an RNA-binding protein, TDP-43, is the most significant pathological finding in approximately 95% of ALS cases and 50% of FTD cases, and discovery of this common pathological signature, together with an increasing understanding of the shared genetic basis of these disorders, has led to FTD and ALS being considered as part of a single disease continuum. Given the widespread aggregation and accumulation of TDP-43 in FTD-ALS spectrum disorder, TDP-43 may have potential as a biomarker in these diseases. METHODS: We therefore conducted a systematic review and meta-analysis to evaluate the diagnostic utility of TDP-43 detected in the cerebrospinal fluid (CSF) of patients with FTD-ALS spectrum disorder. RESULTS: From seven studies, our results demonstrate that patients with ALS have a statistically significantly higher level of TDP-43 in CSF (effect size 0.64, 95% CI: 0.1-1.19, p = 0.02). CONCLUSIONS: These data suggest promise for the use of CSF TDP-43 as a biomarker for ALS.
Subject(s)
Amyotrophic Lateral Sclerosis/cerebrospinal fluid , Biomarkers/cerebrospinal fluid , DNA-Binding Proteins/cerebrospinal fluid , Frontotemporal Dementia/cerebrospinal fluid , Female , HumansABSTRACT
TDP-43 accumulates in nerve cells of nearly all cases of amyotrophic lateral sclerosis (ALS; the commonest form of motor neuron disease) and in the majority of Tau-negative frontotemporal lobar degeneration (FTLD). There is currently no biochemical test or marker of disease activity for ALS or FTLD, and the clinical diagnosis depends on the opinion of an experienced neurologist. TDP-43 has a key role in the pathogenesis of ALS/FTLD. Measuring TDP-43 in easily accessible biofluids, such as blood or cerebrospinal fluid, might reduce diagnostic delay and offer a readout for use in future drug trials. However, attempts at measuring disease-specific forms of TDP-43 in peripheral biofluids of ALS and FTLD patients have not yielded consistent results, and only some of the pathological biochemical features of TDP-43 found in human brain tissue have been detected in clinical biofluids to date. Reflecting on the molecular pathology of TDP-43, this review provides a critical overview on biofluid studies and future directions to develop a TDP-43-based clinical biomarker for ALS and FTLD.
Subject(s)
Amyotrophic Lateral Sclerosis/metabolism , Biomarkers/metabolism , DNA-Binding Proteins/metabolism , Frontotemporal Lobar Degeneration/metabolism , Animals , Brain/pathology , DNA-Binding Proteins/blood , DNA-Binding Proteins/cerebrospinal fluid , DNA-Binding Proteins/chemistry , Humans , Models, BiologicalABSTRACT
Missense mutations in the leucine-rich repeat kinase 2 (LRRK2) gene can cause late-onset Parkinson disease (PD). LRRK2 mutations increase LRRK2 kinase activities that may increase levels of LRRK2 autophosphorylation at serine 1292 (pS1292) and neurotoxicity in model systems. pS1292-LRRK2 protein can be packaged into exosomes and measured in biobanked urine. Herein we provide evidence that pS1292-LRRK2 protein is robustly expressed in cerebral spinal fluid (CSF) exosomes. In a novel cohort of Norwegian subjects with and without the G2019S-LRRK2 mutation, with and without PD, we quantified levels of pS1292-LRRK2, total LRRK2, and other exosome proteins in urine from 132 subjects and in CSF from 82 subjects. CSF and urine were collected from the same morning clinic visit in 55 of the participants. We found that total LRRK2 protein concentration was similar in exosomes purified from either CSF or urine but the levels did not correlate. pS1292-LRRK2 levels were higher in urinary exosomes from male and female subjects with a LRRK2 mutation. Male LRRK2 mutation carriers without PD had intermediate pS1292-LRRK2 levels compared to male carriers with PD and controls. However, female LRRK2 mutation carriers without PD had the same pS1292-LRRK2 levels compared to female carriers with PD. pS1292-LRRK2 levels in CSF exosomes were near saturated in most subjects, ten-fold higher on average than pS1292-LRRK2 levels in urinary exosomes, irrespective of LRRK2 mutation status or PD diagnosis. These results provide insights into the effects of LRRK2 mutations in both the periphery and brain in a well-characterized clinical population and show that LRRK2 protein in brain exosomes may be much more active than in the periphery in most subjects.
Subject(s)
Brain/metabolism , Gene Expression Regulation/genetics , Leucine-Rich Repeat Serine-Threonine Protein Kinase-2/genetics , Leucine-Rich Repeat Serine-Threonine Protein Kinase-2/metabolism , Mutation/genetics , Parkinson Disease/genetics , Aged , Case-Control Studies , Cohort Studies , DNA-Binding Proteins/cerebrospinal fluid , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , DNA-Binding Proteins/urine , Endosomal Sorting Complexes Required for Transport/cerebrospinal fluid , Endosomal Sorting Complexes Required for Transport/genetics , Endosomal Sorting Complexes Required for Transport/metabolism , Endosomal Sorting Complexes Required for Transport/urine , Female , Genetic Predisposition to Disease , HEK293 Cells , Humans , Male , Membrane Proteins/cerebrospinal fluid , Membrane Proteins/urine , Middle Aged , Norway , Parkinson Disease/cerebrospinal fluid , Parkinson Disease/pathology , Parkinson Disease/urine , Phosphorylation/genetics , Serine/genetics , Serine/metabolism , Severity of Illness Index , Transcription Factors/cerebrospinal fluid , Transcription Factors/genetics , Transcription Factors/metabolism , Transcription Factors/urineABSTRACT
BACKGROUND: Frontotemporal dementia (FTD) is a heterogeneous disease both at the clinical, genetic, and pathobiological level. The underlying pathological spectrum (termed FTLD, frontotemporal lobar degeneration) is in most cases defined by accumulation of either tau (FTLD-tau) or TDP-43 proteins (FTLD-TDP). Biomarkers to differentiate these subtypes are not yet available, whereas these are essential requirements to study the natural course of disease and for homogeneous inclusion of patients in clinical studies. OBJECTIVE: To study if a combination of total (t-) and phosphorylated (p-)tau, and t-TDP-43 and p-TDP-43 proteins in cerebrospinal fluid (CSF) is suitable to discriminate FTLD-tau and FTLD-TDP subtypes. METHODS: We developed immunoassays for the quantification of t-TDP-43 and p-TDP-43 proteins and used commercially available assays for the quantification of t-tau and p-tau proteins. We quantified these proteins in ventricular CSF samples from neuropathologically defined FTLD-tau and FTLD-TDP cases to study the reflection of underlying brain pathology in CSF composition, and in lumbar CSF samples from FTLD-tau and FTLD-TDP patients to study the diagnostic potential of CSF biomarkers. RESULTS: In ventricular CSF, t-TDP-43 and t-tau levels, when combined into one model, were significantly different between neuropathologically-defined FTLD-tau and FTLD-TDP cases. In a pilot study using lumbar CSF, the p-tau/t-tau ratio, but not t-TDP-43 levels, were significantly different between FTLD-TDP and FTLD-tau patients. CONCLUSION: We conclude that with current available methods, CSF tau, rather than TDP-43 proteins, may have diagnostic value in the differentiation of FTLD patients with either tau or TDP-43 pathology.
Subject(s)
DNA-Binding Proteins/cerebrospinal fluid , Frontotemporal Lobar Degeneration/cerebrospinal fluid , tau Proteins/cerebrospinal fluid , Aged , Aged, 80 and over , Biomarkers/cerebrospinal fluid , Brain/pathology , Female , Frontotemporal Lobar Degeneration/classification , Frontotemporal Lobar Degeneration/pathology , Humans , Immunoassay , Male , Middle Aged , Pilot ProjectsABSTRACT
BACKGROUND: Despite the discovery of CSF and serum diagnostic autoantibodies in autoimmune encephalitis, there are still very limited CSF biomarkers for diagnostic and monitoring purposes in children with inflammatory or autoimmune brain disease. The cause of encephalitis is unknown in up to a third of encephalitis cohorts, and it is important to differentiate infective from autoimmune encephalitis given the therapeutic implications. AIM: To study CSF cytokines and chemokines as diagnostic biomarkers of active neuroinflammation, and assess their role in differentiating demyelinating, autoimmune, and viral encephalitis. METHODS: We measured and compared 32 cytokine/chemokines using multiplex immunoassay and APRIL and BAFF using ELISA in CSF collected prior to commencing treatment from paediatric patients with confirmed acute disseminated encephalomyelitis (ADEM, n = 16), anti-NMDAR encephalitis (anti-NMDAR E, n = 11), and enteroviral encephalitis (EVE, n = 16). We generated normative data using CSF from 20 non-inflammatory neurological controls. The sensitivity of CSF cytokine/chemokines to diagnose encephalitis cases was calculated using 95th centile of control values as cut off. We correlated CSF cytokine/chemokines with disease severity and follow up outcome based on modified Rankin scale. One-way hierarchical correlational cluster analysis of molecules was performed in different encephalitis and outcome groups. RESULTS: In descending order, CSF TNF-α, IL-10, IFN-α, IL-6, CXCL13 and CXCL10 had the best sensitivity (>79.1%) when all encephalitis patients were included. The combination of IL-6 and IFN-α was most predictive of inflammation on multiple logistic regression with area under the ROC curve 0.99 (CI 0.97-1.00). There were no differences in CSF cytokine concentrations between EVE and anti-NMDAR E, whereas ADEM showed more pronounced elevation of Th17 related (IL-17, IL-21) and Th2 (IL-4, CCL17) related cytokine/chemokines. Unlike EVE, heat map analysis showed similar clustering of cytokine/chemokine molecules in immune mediated encephalitis (ADEM and anti-NMDAR E). Th1 and B cell (CXCL13 and CXCL10) molecules clustered together in patients with severe encephalopathy at admission and worse disability at follow up in all encephalitis. There was no correlation between CSF neopterin and IFN-γ or IFN-α. CONCLUSION: A combination panel of cytokine/chemokines consisting of CSF TNF-α, IL-10, IFN-α, IL-6, CXCL13 and CXCL10 measured using multiplex immunoassay may be used to diagnose and monitor intrathecal inflammation in the brain. Given their association with worse outcome, certain key chemokines (CXCL13, CXCL10) could represent potential therapeutic targets in encephalitis.
Subject(s)
Anti-N-Methyl-D-Aspartate Receptor Encephalitis/immunology , Chemokines/cerebrospinal fluid , Cytokines/cerebrospinal fluid , Encephalitis, Viral/immunology , Encephalomyelitis, Acute Disseminated/immunology , Enterovirus Infections/immunology , Adolescent , Anti-N-Methyl-D-Aspartate Receptor Encephalitis/diagnosis , Biomarkers/cerebrospinal fluid , Child , Child, Preschool , DNA-Binding Proteins/cerebrospinal fluid , DNA-Binding Proteins/metabolism , Diagnosis, Differential , Encephalitis, Viral/diagnosis , Encephalomyelitis, Acute Disseminated/diagnosis , Enterovirus Infections/diagnosis , Female , Humans , Infant , Logistic Models , Male , Proto-Oncogene Proteins B-raf/cerebrospinal fluid , Proto-Oncogene Proteins B-raf/metabolism , ROC Curve , Transcription Factors/cerebrospinal fluid , Transcription Factors/metabolismABSTRACT
The transactive response DNA binding protein (TDP-43) has long been characterized as a main hallmark of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration with ubiquitin-positive inclusions (FTLD-U, also known as FTLD-TDP). Several studies have indicated TDP-43 deposits in Alzheimer's disease (AD) brains and have robust connection with AD clinical phenotype. FTLD-U, which was symptomatically connected with AD, may be predictable for the comprehension of the role TDP-43 in AD. TDP-43 may contribute to AD through both ß-amyloid (Aß)-dependent and Aß-independent pathways. In this article, we summarize the latest studies concerning the role of TDP-43 in AD and explore TDP-43 modulation as a potential therapeutic strategy for AD. However, to date, little of pieces of the research on TDP-43 have been performed to investigate the role in AD; more investigations need to be confirmed in the future.
Subject(s)
Alzheimer Disease/metabolism , DNA-Binding Proteins/metabolism , Alzheimer Disease/blood , Alzheimer Disease/cerebrospinal fluid , Alzheimer Disease/pathology , Amyloid beta-Peptides/metabolism , Animals , DNA-Binding Proteins/blood , DNA-Binding Proteins/cerebrospinal fluid , DNA-Binding Proteins/chemistry , Humans , Models, Biological , Molecular Targeted TherapyABSTRACT
Our objective was to evaluate the CSF phospho-Tau181/total-Tau (p/t-Tau) ratio to distinguish between the two main forms of frontotemporal lobar degeneration (FTLD): FTLD with TDP-43 (FTLD-TDP) and FTLD with Tau inclusions (FTLD-Tau). CSF p/t-Tau ratio was examined in 79 FTLD patients with predictable neuropathology, i.e. Tau (affected by progressive supranuclear palsy or carriers of mutations within the MAPT gene) or TDP-43 (carriers of mutations within granulin, C9orf72, TARDBP genes or affected by FTD with motor neuron disease). FTLD patients were randomly grouped in a training cohort (n = 39) to assess the best CSF p/t-Tau cut-off score according to ROC analysis, and a validation cohort (n = 40) to evaluate accuracy values of the identified marker. Results showed that, in the training cohort, we found a significantly reduced CSF p/t-Tau ratio in FTLD-TDP relative to FTLD-Tau. ROC analysis for p/t-Tau ratio was 0.873 and cut-off score of 0.136 allowed to differentiate FTLD-TDP and FTLD-Tau with 81.8% sensitivity and 88.2% specificity, respectively. Analysis in the validation cohort showed CSF p/t-Tau ratio < 0.136 to distinguish FTLD-TDP from FTLD-Tau with 83.3% specificity and 63.6% sensitivity, respectively. The positive predictive value of detecting TDP neuropathology was 82.4%. In conclusion, a reduced CSF p/t-Tau ratio represents a viable biomarker to correctly identify TDP pathology in FTLD.
Subject(s)
DNA-Binding Proteins/cerebrospinal fluid , Frontotemporal Dementia/cerebrospinal fluid , tau Proteins/cerebrospinal fluid , Aged , Aged, 80 and over , Amyloid beta-Peptides/cerebrospinal fluid , Cohort Studies , DNA-Binding Proteins/genetics , Enzyme-Linked Immunosorbent Assay , Female , Humans , Italy , Male , Middle Aged , Peptide Fragments/cerebrospinal fluid , Phosphorylation , tau Proteins/geneticsABSTRACT
Transactivation response DNA-binding protein 43 (TDP-43) proteinopathy has recently been reported in chronic traumatic encephalopathy, a neurodegenerative condition linked to prior history of traumatic brain injury (TBI). While TDP-43 appears to be vulnerable to proteolytic modifications under neurodegenerative conditions, the mechanism underlying the contribution of TDP-43 to the pathogenesis of TBI remains unknown. In this study, we first mapped out the calpain or caspase-3 TDP-43 fragmentation patterns by in vitro protease digestion. Concurrently, in cultured cerebrocortical neurons subjected to cell death challenges, we identified distinct TDP-43 breakdown products (BDPs) of 35, 33, and 12 kDa that were indicative of dual calpain/caspase attack. Cerebrocortical culture incubated with calpain and caspase-fragmented TDP-43 resulted in neuronal injury. Furthermore, increased TDP-43 BDPs as well as redistributed TDP-43 from the nucleus to the cytoplasm were observed in the mouse cortex in two TBI models: controlled cortical impact injury and overpressure blast-wave-induced brain injury. Finally, TDP-43 and its 35 kDa fragment levels were also elevated in the cerebrospinal fluid (CSF) of severe TBI patients. This is the first evidence that TDP-43 might be involved in acute neuroinjury and TBI pathology, and that TDP-43 and its fragments may have biomarker utilities in TBI patients.
Subject(s)
Brain Injuries/cerebrospinal fluid , Calpain/cerebrospinal fluid , Caspase 3/cerebrospinal fluid , DNA-Binding Proteins/cerebrospinal fluid , Proteolysis , Animals , Brain Injuries/pathology , Cells, Cultured , Cerebral Cortex/metabolism , Cerebral Cortex/pathology , Disease Models, Animal , Female , Humans , Male , Mice , Neurons/metabolism , Neurons/pathology , RatsSubject(s)
Biomarkers/analysis , Frontotemporal Dementia/diagnosis , Biomarkers/blood , Biomarkers/cerebrospinal fluid , DNA-Binding Proteins/blood , DNA-Binding Proteins/cerebrospinal fluid , Frontotemporal Dementia/metabolism , Frontotemporal Dementia/pathology , Humans , Intercellular Signaling Peptides and Proteins/blood , Progranulins , RNA-Binding Protein FUS/blood , RNA-Binding Protein FUS/cerebrospinal fluid , tau Proteins/blood , tau Proteins/cerebrospinal fluidABSTRACT
TAR DNA-binding protein 43 (TDP-43) is one of the neuropathological hallmarks in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). It is present in patients' blood and cerebrospinal fluid (CSF); however, the source and clinical relevance of TDP-43 measurements in body fluids is uncertain. We investigated paired CSF and serum samples, blood lymphocytes, brain urea fractions and purified exosomes from CSF for TDP-43 by one- (1D), and two-dimensional (2D) Western immunoblotting (WB) and quantitative mass spectrometry (MRM) in patients with ALS, FTLD and non-neurodegenerative diseases. By means of 2D-WB we were able to demonstrate a similar isoform pattern of TDP-43 in lymphocytes, serum and CSF in contrast to that of brain urea fractions with TDP-43 pathology. We found that the TDP-43 CSF to blood concentration ratio is about 1:200. As a possible brain specific fraction we found TDP-43 in exosome preparations from CSF by immunoblot and MRM. We conclude that TDP-43 in CSF originates mainly from blood. Measurements of TDP-43 in CSF and blood are of minor importance as a diagnostic tool, but may be important for monitoring therapy effects of TDP-43 modifying drugs.
Subject(s)
DNA-Binding Proteins/blood , DNA-Binding Proteins/cerebrospinal fluid , Neurodegenerative Diseases/cerebrospinal fluid , Aged , DNA-Binding Proteins/ultrastructure , Exosomes/metabolism , Exosomes/ultrastructure , Female , Humans , Lymphocytes/metabolism , Male , Mass Spectrometry , Membrane Proteins/metabolism , Microscopy, Electron, Transmission , Middle Aged , Molecular Weight , Neurodegenerative Diseases/blood , Neurodegenerative Diseases/diagnosisABSTRACT
OBJECTIVES: About a half of patients with frontotemporal dementia (FTD) has deposition of phosphorylated TDP-43 protein (pTDP-43) in the brain. We studied pTDP-43 and total TDP-43 levels in plasma and cerebrospinal fluid (CSF) in healthy controls and patients with FTD, including those carrying a repeat expansion in the C9orf72 gene or a mutation in GRN. METHODS: We included 88 plasma samples of 10 C9orf72 expansion carriers, 5 GRN mutation carriers, 51 patients with FTD without a known mutation and 22 healthy controls. We also obtained CSF samples from 25 patients with FTD (2 with C9orf72 expansion and 3 with a GRN mutation) and 22 healthy controls. We measured pTDP-43 and total TDP-43 levels using sandwich ELISA. RESULTS: Patients carrying the C9orf72 repeat expansion or a GRN mutation had significantly higher plasma and CSF levels of pTDP-43 than the remaining patients with FTD (p<0.05). In addition, plasma pTDP-43 levels were higher in patients with FTD carrying a C9orf72 expansion or GRN mutations than in healthy controls (p<0.05). CONCLUSIONS: Our study shows that plasma pTDP-43 levels may be increased in some genetic forms of FTD known to be associated with TDP-43 proteinopathies.