[Show abstract][Hide abstract] ABSTRACT: Questions under study:
Alzheimer-type amyloid-β (Aβ) pathology was reported in brains of individuals developing iatrogenic Creutzfeldt-Jakob disease (iCJD) after treatment with human cadaveric growth hormone, and interpreted as evidence of human transmission of Aβ by the treatment. Here we investigated the prevalence of Aβ pathology in other instances of iCJD related to dura mater grafts.
By use of immunohistochemistry for Aβ, we investigated seven brains of patients (age range 28-63) who succumbed to iCJD after dural grafting, which had been applied by means of neurosurgery between 11 and 25 years before death. For control, we examined a series of 21 brains of age-matched (40-63 years) patients with sporadic CJD (sCJD) and an additional series of 81 sCJD cases (55-85 years) with the same methods.
In five of seven iCJD brains, Aβ was deposited in meningeal vessels as congophilic amyloid angiopathy and brain parenchymal plaques. This was significantly (p <0.001) more frequent than in the age-matched sCJD controls and in the usual sCJD series.
We conclude that congophilic amyloid angiopathy and brain parenchymal Aβ plaques are frequent in iCJD after dural grafting. The presence of Aβ pathology in young individuals is highly unusual and suggests a causal relationship to the dural grafts. Further studies will be needed to elucidate whether such pathology resulted from the seeding of Aβ aggregates from the grafts to host tissues.
Full-text · Article · Jan 2016 · Schweizerische medizinische Wochenschrift
[Show abstract][Hide abstract] ABSTRACT: Pathological accumulation of abnormally phosphorylated tau protein in astrocytes is a frequent, but poorly characterized feature of the aging brain. Its etiology is uncertain, but its presence is sufficiently ubiquitous to merit further characterization and classification, which may stimulate clinicopathological studies and research into its pathobiology. This paper aims to harmonize evaluation and nomenclature of aging-related tau astrogliopathy (ARTAG), a term that refers to a morphological spectrum of astroglial pathology detected by tau immunohistochemistry, especially with phosphorylation-dependent and 4R isoform-specific antibodies. ARTAG occurs mainly, but not exclusively, in individuals over 60 years of age. Tau-immunoreactive astrocytes in ARTAG include thorn-shaped astrocytes at the glia limitans and in white matter, as well as solitary or clustered astrocytes with perinuclear cytoplasmic tau immunoreactivity that extends into the astroglial processes as fine fibrillar or granular immunopositivity, typically in gray matter. Various forms of ARTAG may coexist in the same brain and might reflect different pathogenic processes. Based on morphology and anatomical distribution, ARTAG can be distinguished from primary tauopathies, but may be concurrent with primary tauopathies or other disorders. We recommend four steps for evaluation of ARTAG: (1) identification of five types based on the location of either morphologies of tau astrogliopathy: subpial, subependymal, perivascular, white matter, gray matter; (2) documentation of the regional involvement: medial temporal lobe, lobar (frontal, parietal, occipital, lateral temporal), subcortical, brainstem; (3) documentation of the severity of tau astrogliopathy; and (4) description of subregional involvement. Some types of ARTAG may underlie neurological symptoms; however, the clinical significance of ARTAG is currently uncertain and awaits further studies. The goal of this proposal is to raise awareness of astroglial tau pathology in the aged brain, facilitating communication among neuropathologists and researchers, and informing interpretation of clinical biomarkers and imaging studies that focus on tau-related indicators.
Full-text · Article · Dec 2015 · Acta Neuropathologica
[Show abstract][Hide abstract] ABSTRACT: Human genetic prion diseases have invariably been linked to alterations of the prion protein (PrP) gene PRNP. Two sisters died from probable Creutzfeldt-Jakob disease (CJD) in Switzerland within 14 years. At autopsy, both patients had typical spongiform change in their brains accompanied by punctuate deposits of PrP. Biochemical analyses demonstrated proteinase K-resistant PrP. Sequencing of PRNP showed two wild-type alleles in both siblings. Retrospectively, clinical data revealed a history of dural transplantation in the initially deceased sister, compatible with a diagnosis of iatrogenic CJD. Clinical and familial histories provided no evidence for potential horizontal transmission. This observation of two siblings suffering from CJD without mutations in the PRNP gene suggests potential involvement of non-PRNP genes in prion disease etiology.
[Show abstract][Hide abstract] ABSTRACT: Prions cause transmissible spongiform encephalopathies for which no treatment exists. Prions consist of PrP(Sc), a misfolded and aggregated form of the cellular prion protein (PrP(C)). We explore the antiprion properties of luminescent conjugated polythiophenes (LCPs) that bind and stabilize ordered protein aggregates. By administering a library of structurally diverse LCPs to the brains of prion-infected mice via osmotic minipumps, we found that antiprion activity required a minimum of five thiophene rings bearing regularly spaced carboxyl side groups. Solid-state nuclear magnetic resonance analyses and molecular dynamics simulations revealed that anionic side chains interacted with complementary, regularly spaced cationic amyloid residues of model prions. These findings allowed us to extract structural rules governing the interaction between LCPs and protein aggregates, which we then used to design a new set of LCPs with optimized binding. The new set of LCPs showed robust prophylactic and therapeutic potency in prion-infected mice, with the lead compound extending survival by >80% and showing activity against both mouse and hamster prions as well as efficacy upon intraperitoneal administration into mice. These results demonstrate the feasibility of targeted chemical design of compounds that may be useful for treating diseases of aberrant protein aggregation such as prion disease.
No preview · Article · Aug 2015 · Science translational medicine
[Show abstract][Hide abstract] ABSTRACT: We performed a genome-wide association (GWA) study in 434 sporadic Creutzfeldt-Jakob disease (sCJD) patients and 1939 controls from the United Kingdom, Germany and The Netherlands. The findings were replicated in an independent sample of 1109 sCJD and 2264 controls provided by a multinational consortium. From the initial GWA analysis we selected 23 SNPs for further genotyping in 1109 sCJD cases from seven different countries. Five SNPs were significantly associated with sCJD after correction for multiple testing. Subsequently these five SNPs were genotyped in 2264 controls. The pooled analysis, including 1543 sCJD cases and 4203 controls, yielded two genome wide significant results: rs6107516 (p-value=7.62×10-9) a variant tagging the prion protein gene (PRNP); and rs6951643 (p-value=1.66×10-8) tagging the Glutamate Receptor Metabotropic 8 gene (GRM8). Next we analysed the data stratifying by country of origin combining samples from the pooled analysis with genotypes from the 1000 Genomes Project and imputed genotypes from the Rotterdam Study (Total n=12967). The meta-analysis of the results showed that rs6107516 (p-value=3.00×10-8) and rs6951643 (p-value=3.91×10-5) remained as the two most significantly associated SNPs. Rs6951643 is located in an intronic region of GRM8, a gene that was additionally tagged by a cluster of 12 SNPs within our top100 ranked results. GRM8 encodes for mGluR8, a protein which belongs to the metabotropic glutamate receptor family, recently shown to be involved in the transduction of cellular signals triggered by the prion protein. Pathway enrichment analyses performed with both Ingenuity Pathway Analysis and ALIGATOR postulates glutamate receptor signalling as one of the main pathways associated with sCJD. In summary, we have detected GRM8 as a novel, non-PRNP, genome-wide significant marker associated with heightened disease risk, providing additional evidence supporting a role of glutamate receptors in sCJD pathogenesis.
[Show abstract][Hide abstract] ABSTRACT: Neuromyelitis optica (NMO) is an inflammatory demyelinating disease of the CNS with severe involvement of the optic nerve and spinal cord. Highly specific serum IgG autoantibodies (NMO-IgG) that react with aquaporin-4 (AQP4), the most abundant CNS water channel protein, are found in patients with NMO. However, in vivo evidence combining the results of AQP4 antibody serum levels and brain pathology is lacking. We report a patient with NMO whose AQP4 antibody levels decreased simultaneously with clinical deterioration caused by the development of a tumor-like brain lesion. In the seminecrotic biopsied brain lesion, there was activated complement complex, whereas only very scattered immunoreactivity to AQP4 protein was detectable. The decrease in serum AQP4 antibody levels and the loss of AQP4 in the tumor-like lesion could represent a "serum antibody-consuming effect" during lesion formation.This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License, where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially.
Full-text · Article · Feb 2015 · Journal of Neuropathology and Experimental Neurology
[Show abstract][Hide abstract] ABSTRACT: Prion infections cause neurodegeneration, which often goes along with oxidative stress. However, the cellular source of reactive oxygen species (ROS) and their pathogenetic significance are unclear. Here we analyzed the contribution of NOX2, a prominent NADPH oxidase, to prion diseases. We found that NOX2 is markedly upregulated in microglia within affected brain regions of patients with Creutzfeldt-Jakob disease (CJD). Similarly, NOX2 expression was upregulated in prion-inoculated mouse brains and in murine cerebellar organotypic cultured slices (COCS). We then removed microglia from COCS using a ganciclovir-dependent lineage ablation strategy. NOX2 became undetectable in ganciclovir-treated COCS, confirming its microglial origin. Upon challenge with prions, NOX2-deficient mice showed delayed onset of motor deficits and a modest, but significant prolongation of survival. Dihydroethidium assays demonstrated a conspicuous ROS burst at the terminal stage of disease in wild-type mice, but not in NOX2-ablated mice. Interestingly, the improved motor performance in NOX2 deficient mice was already measurable at earlier stages of the disease, between 13 and 16 weeks post-inoculation. We conclude that NOX2 is a major source of ROS in prion diseases and can affect prion pathogenesis.
[Show abstract][Hide abstract] ABSTRACT: Objective
To identify the prevalence of MRI features of Binswanger's disease (BD), specifically MRI with diffuse white matter lesions and scattered multiple lacunes (BD-MRI), and to describe neurological features and pathological outcomes of a community-based cohort study.Methods
Of 697 participants (all 75 years old), 503 completed neurological examinations at baseline and were followed-up every 30 months thereafter with MRIs, the mini-mental state examination (MMSE) and the Unified Parkinson Disease Rating Scale-Motor Section (UPDRSM). Data from participants with BD-MRI were compared with those from participants with predominant white matter lesions (WML-MRI), scattered multiple lacunes (ML-MRI), or normal MRIs.ResultsFourteen BD-MRI patients (2.8%) were detected at baseline. The mean MMSE scores in the BD-MRI, WML-MRI, ML-MRI, and normal MRIs groups were 26.4, 28.2, 28.4, and 28.5, respectively, and the mean UPDRSM scores were 9.1, 1.3, 3.1, and 1.7, respectively. At the 30-month follow-up, mortality rates in the normal MRIs, WML-MRI and ML-MRI were 4%, 9.1%, and 22.2%, respectively, and follow-up MRIs were available for 80%, 82%, and 61% of the participants, respectively. In the BD-MRI, however, five patients were deceased, and only five follow-up individual MRIs were available (33.3%). Autopsies were performed on six of eight BD-MRI brains, and these brains fulfilled the pathological criteria for BD independent of Alzheimer disease pathology. All these six individuals also showed systemic atherosclerosis and renal arterio-arteriolosclerosis.InterpretationThe BD-MRI participants had poor prognoses and showed pure BD pathology with advanced systemic vascular disease. BD-MRI appears to be a predictor of vascular neurocognitive impairment.
[Show abstract][Hide abstract] ABSTRACT: Dementia with Lewy bodies (DLB), Parkinson’s disease (PD) and multiple system atrophy are characterized by the deposition of disease-associated α-synuclein. In the present study we 1) examined the molecular specificity of the novel anti-α-synuclein 5G4 antibody; 2) evaluated immunoreactivity patterns and their correlation in human brain tissue with micro- and astrogliosis in 57 cases with PD or DLB; and 3) performed a systematic immunoelectron microscopical mapping of subcellular localizations. 5G4 strongly binds to the high molecular weight fraction of β-sheet rich oligomers, while no binding to primarily disordered oligomers or monomers was observed. We show novel localizations of disease-associated α-synuclein including perivascular macrophages, ependyma and cranial nerves. α-Synuclein immunoreactive neuropil dots and thin threads associate more with glial reaction than Lewy bodies alone. Astrocytic α-synuclein is an important component of the pathology. Furthermore, we document ultrastructurally the pathway of processing of disease-associated α-synuclein within neurons and astroglial cells. Interaction of mitochondria and disease-associated α-synuclein plays a key role in the molecular–structural cytopathogenesis of disorders with Lewy bodies. We conclude that 1) the 5G4 antibody has strong selectivity for β-sheet rich α-synuclein oligomers; 2) Lewy bodies themselves are not the most relevant morphological substrate that evokes tissue lesioning; 3) both neurons and astrocytes internalize disease-associated α-synuclein in the human brain, suggesting prion-like cell-to-cell spread of α-synuclein by uptake from surrounding structures, as shown previously in experimental observations.
Full-text · Article · Sep 2014 · Neurobiology of Disease
[Show abstract][Hide abstract] ABSTRACT: Objective
We sought to identify the prevalence of MRI features of disproportionately enlarged subarachnoid space hydrocephalus in possible idiopathic normal pressure hydrocephalus (DESH-iNPH) and to describe the clinico-radiological features and outcomes of a community-based investigation (The Vienna Trans-Danube Aging study).Methods
Of the 697 inhabitants (all 75 years old), 503 completed extensive neurological examinations at baseline and were followed up every 30 months thereafter with MRIs, mini-mental state examination (MMSE), and the Unified Parkinson Disease Rating Scale-Motor Section (UPDRSM). The DESH-iNPH participant data were compared with the data from participants with Evans index ratios >0.3 (ex vacuo hydrocephalus), cerebral small-vessel diseases, and normal MRIs. The widening of perivascular space was also evaluated by MRI in these groups.ResultsEight participants with DESH-iNPH (1.6%) and 76 with ex vacuo hydrocephalus (16.1%) at baseline were identified. The mean MMSE in DESH-iNPH, ex vacuo hydrocephalus, and normal MRIs was 26.4, 27.9, and 28.3, respectively, and the mean UPDRSM was 9.75, 2.96, and 1.87, respectively. After a 90-month follow-up, the mortality rates for DESH-iNPH, ex vacuo hydrocephalus, and normal MRIs were 25.0%, 21.3%, and 10.9%, respectively. The perivascular-space widening scores were significantly smaller in the DESH-iNPH cases, particularly at the centrum semiovale, compared to cerebral small-vessel disease and ex vacuo hydrocephalus cases.InterpretationThe prevalence of DESH-iNPH was 1.6% for participants aged 75 years and revealed significantly lower MMSE and higher UPDRSM scores compared to the ex vacuo hydrocephalus and controls. Moreover, it is suggested that perivascular-space narrowing is a morphological and pathophysiological marker of DESH-iNPH.
[Show abstract][Hide abstract] ABSTRACT: Identification of etiological connections among virtually distinct diseases in a patient may be sometimes challenging. We report a unique case with two B cell malignancies and an inflammatory leukoencephalopathy. Three days prior to admission, the elderly male patient developed fatigue, headaches, recurrent vomiting, memory disturbances, depression and somnolence. Clinical, laboratory and imaging evaluations as well as post mortem histological studies were performed. Simultaneous presence of primary central nervous system B cell lymphoma, temporal lobe inflammatory leukoencephalopathy and multiple (smoldering) myeloma, was revealed by the detailed work up in the treatment-naïve patient. Based on recent data from genomic studies, we propose that a sequential evolution of molecular pathology lead to the co-occurrence of multiple myeloma and primary central nervous system B cell lymphoma in this patient, and interpret the development of the temporal lobe leukoencephalopathy as a likely paraneoplastic complication of smoldering myeloma.
No preview · Article · Mar 2014 · Ideggyógyászati szemle
[Show abstract][Hide abstract] ABSTRACT: Human prion diseases are a group of rare fatal neurodegenerative conditions with well-developed clinical and neuropathological diagnostic criteria. Recent observations have expanded the spectrum of prion diseases beyond the classically recognized forms.
In the present study we report six patients with a novel, apparently sporadic disease characterised by thalamic degeneration and rapidly progressive dementia (duration of illness 2¿12 months; age at death: 55¿81 years). Light and electron microscopic immunostaining for the prion protein (PrP) revealed a peculiar intraneuritic distribution in neocortical regions. Proteinase K resistant PrP (PrPres) was undetectable by Western blotting in frontal cortex from the three cases with frozen tissue, even after enrichment for PrPres by centrifugation or by phosphotungstic acid precipitation. Conformation-dependent immunoassay analysis using a range of PK digestion conditions (and no PK digestion) produced only very limited evidence of meaningful D-N (denatured/native) values, indicative of the presence of disease-associated PrP (PrPSc) in these cases, when the results were compared with appropriate negative control groups.
Our observation expands the spectrum of conditions associated with rapidly progressive dementia and may have implications for the understanding of the pathogenesis of prion diseases.