Structures of α-synuclein filaments from human brains with Lewy pathology.

Parkinson's disease (PD) is the most common movement disorder, with resting tremor, rigidity, bradykinesia and postural instability being major symptoms1. Neuropathologically, it is characterized by the presence of abundant filamentous inclusions of α-synuclein in the form of Lewy bodies and Lewy neurites in some brain cells, including dopaminergic nerve cells of the substantia nigra2. PD is increasingly recognised as a multisystem disorder, with cognitive decline being one of its most common non-motor symptoms. Many patients with PD develop dementia more than 10 years after diagnosis3. PD dementia (PDD) is clinically and neuropathologically similar to dementia with Lewy bodies (DLB), which is diagnosed when cognitive impairment precedes parkinsonian motor signs or begins within one year from their onset4. In PDD, cognitive impairment develops in the setting of well-established PD. Besides PD and DLB, multiple system atrophy (MSA) is the third major synucleinopathy5. It is characterized by the presence of abundant filamentous α-synuclein inclusions in brain cells, especially oligodendrocytes (Papp-Lantos bodies). We previously reported the electron cryo-microscopy structures of two types of α-synuclein filament extracted from the brains of individuals with MSA6. Each filament type is made of two different protofilaments. Here we report that the cryo-electron microscopy structures of α-synuclein filaments from the brains of individuals with PD, PDD and DLB are made of a single protofilament (Lewy fold) that is markedly different from the protofilaments of MSA. These findings establish the existence of distinct molecular conformers of assembled α-synuclein in neurodegenerative disease.

Age-dependent formation of TMEM106B amyloid filaments in human brains.

Many age-dependent neurodegenerative diseases, such as Alzheimer's and Parkinson's, are characterized by abundant inclusions of amyloid filaments. Filamentous inclusions of the proteins tau, amyloid-ß, α-synuclein and transactive response DNA-binding protein (TARDBP; also known as TDP-43) are the most common1,2. Here we used structure determination by cryogenic electron microscopy to show that residues 120-254 of the lysosomal type II transmembrane protein 106B (TMEM106B) also form amyloid filaments in human brains. We determined the structures of TMEM106B filaments from a number of brain regions of 22 individuals with abundant amyloid deposits, including those resulting from sporadic and inherited tauopathies, amyloid-ß amyloidoses, synucleinopathies and TDP-43 proteinopathies, as well as from the frontal cortex of 3 individuals with normal neurology and no or only a few amyloid deposits. We observed three TMEM106B folds, with no clear relationships between folds and diseases. TMEM106B filaments correlated with the presence of a 29-kDa sarkosyl-insoluble fragment and globular cytoplasmic inclusions, as detected by an antibody specific to the carboxy-terminal region of TMEM106B. The identification of TMEM106B filaments in the brains of older, but not younger, individuals with normal neurology indicates that they form in an age-dependent manner.

Structure-based classification of tauopathies.

The ordered assembly of tau protein into filaments characterizes several neurodegenerative diseases, which are called tauopathies. It was previously reported that, by cryo-electron microscopy, the structures of tau filaments from Alzheimer's disease1,2, Pick's disease3, chronic traumatic encephalopathy4 and corticobasal degeneration5 are distinct. Here we show that the structures of tau filaments from progressive supranuclear palsy (PSP) define a new three-layered fold. Moreover, the structures of tau filaments from globular glial tauopathy are similar to those from PSP. The tau filament fold of argyrophilic grain disease (AGD) differs, instead resembling the four-layered fold of corticobasal degeneration. The AGD fold is also observed in ageing-related tau astrogliopathy. Tau protofilament structures from inherited cases of mutations at positions +3 or +16 in intron 10 of MAPT (the microtubule-associated protein tau gene) are also identical to those from AGD, suggesting that relative overproduction of four-repeat tau can give rise to the AGD fold. Finally, the structures of tau filaments from cases of familial British dementia and familial Danish dementia are the same as those from cases of Alzheimer's disease and primary age-related tauopathy. These findings suggest a hierarchical classification of tauopathies on the basis of their filament folds, which complements clinical diagnosis and neuropathology and also allows the identification of new entities-as we show for a case diagnosed as PSP, but with filament structures that are intermediate between those of globular glial tauopathy and PSP.

Progression of atypical parkinsonian syndromes: PROSPECT-M-UK study implications for clinical trials.

The advent of clinical trials of disease-modifying agents for neurodegenerative disease highlights the need for evidence-based end point selection. Here we report the longitudinal PROSPECT-M-UK study of progressive supranuclear palsy (PSP), corticobasal syndrome (CBS), multiple system atrophy (MSA) and related disorders, to compare candidate clinical trial end points. In this multicentre UK study, participants were assessed with serial questionnaires, motor examination, neuropsychiatric and MRI assessments at baseline, 6 and 12 months. Participants were classified by diagnosis at baseline and study end, into Richardson syndrome, PSP-subcortical (PSP-parkinsonism and progressive gait freezing subtypes), PSP-cortical (PSP-frontal, PSP-speech and language and PSP-CBS subtypes), MSA-parkinsonism, MSA-cerebellar, CBS with and without evidence of Alzheimer's disease pathology and indeterminate syndromes. We calculated annual rate of change, with linear mixed modelling and sample sizes for clinical trials of disease-modifying agents, according to group and assessment type. Two hundred forty-three people were recruited [117 PSP, 68 CBS, 42 MSA and 16 indeterminate; 138 (56.8%) male; age at recruitment 68.7 ± 8.61 years]. One hundred and fifty-nine completed the 6-month assessment (82 PSP, 27 CBS, 40 MSA and 10 indeterminate) and 153 completed the 12-month assessment (80 PSP, 29 CBS, 35 MSA and nine indeterminate). Questionnaire, motor examination, neuropsychiatric and neuroimaging measures declined in all groups, with differences in longitudinal change between groups. Neuroimaging metrics would enable lower sample sizes to achieve equivalent power for clinical trials than cognitive and functional measures, often achieving N < 100 required for 1-year two-arm trials (with 80% power to detect 50% slowing). However, optimal outcome measures were disease-specific. In conclusion, phenotypic variance within PSP, CBS and MSA is a major challenge to clinical trial design. Our findings provide an evidence base for selection of clinical trial end points, from potential functional, cognitive, clinical or neuroimaging measures of disease progression.

Pathological Validation of the MDS Criteria for the Diagnosis of Multiple System Atrophy.

BACKGROUND: The recent International Parkinson and Movement Disorder Society diagnostic criteria for multiple system atrophy (MDS-MSA) have been developed to improve diagnostic accuracy although their diagnostic properties have not been evaluated. OBJECTIVES: The aims were to validate the MDS-MSA diagnostic criteria against neuropathological diagnosis and compare their diagnostic performance to previous criteria and diagnosis in clinical practice. METHODS: Consecutive patients with sporadic, progressive, adult-onset parkinsonism, or cerebellar ataxia from the Queen Square Brain Bank between 2009 and 2019 were selected and divided based on neuropathological diagnosis into MSA and non-MSA. Medical records were systematically reviewed, and clinical diagnosis was documented by retrospectively applying the MDS-MSA criteria, second consensus criteria, and diagnosis according to treating clinicians at early (within 3 years of symptom onset) and final stages. Diagnostic parameters (sensitivity, specificity, positive/negative predictive value, and accuracy) were calculated using neuropathological diagnosis as gold standard and compared between different criteria. RESULTS: Three hundred eighteen patients (103 MSA and 215 non-MSA) were included, comprising 248 patients with parkinsonism and 70 with cerebellar ataxia. Clinically probable MDS-MSA showed excellent sensitivity (95.1%), specificity (94.0%), and accuracy (94.3%), although their sensitivity at early stages was modest (62.1%). Clinically probable MDS-MSA outperformed diagnosis by clinicians and by second consensus criteria. Clinically established MDS-MSA showed perfect specificity (100%) even at early stages although to the detriment of low sensitivity. MDS-MSA diagnostic accuracy did not differ according to clinical presentation (ataxia vs. parkinsonism). CONCLUSIONS: MDS-MSA criteria demonstrated excellent diagnostic performance against neuropathological diagnosis and are useful diagnostic tools for clinical practice and research. © 2023 International Parkinson and Movement Disorder Society.

Clinical Diagnostic Accuracy of Parkinson's Disease: Where Do We Stand?

BACKGROUND: Clinical diagnostic accuracy of Parkinson's disease (PD) remains suboptimal. Changes in disease concept may have improved clinical diagnostic accuracy in the past decade. However, current clinical diagnostic criteria have not been validated against neuropathological confirmation. OBJECTIVES: This study aims to provide up-to-date clinical diagnostic accuracy data and validate current clinical diagnostic criteria for PD against neuropathology. METHODS: A retrospective review of medical records of consecutive patients with parkinsonism from the Queen Square Brain Bank was performed between 2009 and 2019. Clinical diagnosis was documented at early (within 5 years of motor symptom onset) and final stages and categorized by movement disorder experts or regular clinicians. Movement Disorder Society Parkinson's disease (MDS-PD) diagnostic criteria were retrospectively applied. Diagnostic accuracy parameters (sensitivity, specificity, positive/negative predictive value, and accuracy) were calculated using neuropathological diagnosis as the gold standard. RESULTS: A total of 267 patients (141 PD and 126 non-PD parkinsonism) were included. Clinical diagnostic accuracy was 97.2% for experts, 92.5% for the MDS clinically probable PD criteria, and 90.3% for clinicians. Similar figures were obtained when applied at an early stage (91.5%, 89.5%, and 84.2% diagnostic accuracy, respectively). MDS clinically established early PD criteria demonstrated very high specificity (98.4%) at early stages. CONCLUSIONS: Our results showed an important improvement in PD clinical diagnostic accuracy in clinical practice over the past decade, more marked at early stages of the disease. MDS-PD diagnostic criteria is a valid tool in clinical practice and research for the identification of PD patients showing excellent sensitivity and specificity, although movement disorder experts' diagnosis remains the gold standard PD diagnosis during life. © 2023 International Parkinson and Movement Disorder Society.

Rational design of balanced dual-targeting antibiotics with limited resistance.

Antibiotics that inhibit multiple bacterial targets offer a promising therapeutic strategy against resistance evolution, but developing such antibiotics is challenging. Here we demonstrate that a rational design of balanced multitargeting antibiotics is feasible by using a medicinal chemistry workflow. The resultant lead compounds, ULD1 and ULD2, belonging to a novel chemical class, almost equipotently inhibit bacterial DNA gyrase and topoisomerase IV complexes and interact with multiple evolutionary conserved amino acids in the ATP-binding pockets of their target proteins. ULD1 and ULD2 are excellently potent against a broad range of gram-positive bacteria. Notably, the efficacy of these compounds was tested against a broad panel of multidrug-resistant Staphylococcus aureus clinical strains. Antibiotics with clinical relevance against staphylococcal infections fail to inhibit a significant fraction of these isolates, whereas both ULD1 and ULD2 inhibit all of them (minimum inhibitory concentration [MIC] ≤1 µg/mL). Resistance mutations against these compounds are rare, have limited impact on compound susceptibility, and substantially reduce bacterial growth. Based on their efficacy and lack of toxicity demonstrated in murine infection models, these compounds could translate into new therapies against multidrug-resistant bacterial infections.

Globular glial tauopathy type II.

The globular glial tauopathies (GGTs) are a rare group of neurodegenerative diseases with fewer than 90 autopsy-confirmed cases reported in the literature. Although there has been some uncertainty about whether GGT is entirely distinct from progressive supranuclear palsy, a recent study of tau filament structures supports the definition of GGT as a separate neuropathological entity. We present a sporadic case of GGT type II presenting with a progressive corticobasal-primary lateral sclerosis overlap syndrome in a 74-year-old woman. Neuropathological examination identified neuronal and glial tau inclusions, including globular astrocytic and oligodendroglial inclusions. We also discuss the clinical features and molecular pathophysiology of GGT. Increased awareness of this condition could become more important as patients with GGT may be candidates for anti-tau therapies currently undergoing clinical evaluation in patients with other tauopathies.

Rainwater Charitable Foundation criteria for the neuropathologic diagnosis of progressive supranuclear palsy.

Neuropathologic criteria for progressive supranuclear palsy (PSP) proposed by a National Institute of Neurological Disorders and Stroke (NINDS) working group were published in 1994 and based on the presence of neurofibrillary tangles in basal ganglia and brainstem. These criteria did not stipulate detection methods or incorporate glial tau pathology. In this study, a group of 14 expert neuropathologists scored digital slides from 10 brain regions stained with hematoxylin and eosin (H&E) and phosphorylated tau (AT8) immunohistochemistry. The cases included 15 typical and atypical PSP cases and 10 other tauopathies. Blinded to clinical and neuropathological information, raters provided a categorical diagnosis (PSP or not-PSP) based upon provisional criteria that required neurofibrillary tangles or pretangles in two of three regions (substantia nigra, subthalamic nucleus, globus pallidus) and tufted astrocytes in one of two regions (peri-Rolandic cortices, putamen). The criteria showed high sensitivity (0.97) and specificity (0.91), as well as almost perfect inter-rater reliability for diagnosing PSP and differentiating it from other tauopathies (Fleiss kappa 0.826). Most cases (17/25) had 100% agreement across all 14 raters. The Rainwater Charitable Foundation criteria for the neuropathologic diagnosis of PSP feature a simplified diagnostic algorithm based on phosphorylated tau immunohistochemistry and incorporate tufted astrocytes as an essential diagnostic feature.

Methotrexate-related central neurotoxicity: clinical characteristics, risk factors and genome-wide association study in children treated for acute lymphoblastic leukemia.

Symptomatic methotrexate-related central neurotoxicity (MTX neurotoxicity) is a severe toxicity experienced during acute lymphoblastic leukemia (ALL) therapy with potential long-term neurologic complications. Risk factors and long-term outcomes require further study. We conducted a systematic, retrospective review of 1,251 consecutive Australian children enrolled on Berlin-Frankfurt-Münster or Children's Oncology Group-based protocols between 1998-2013. Clinical risk predictors for MTX neurotoxicity were analyzed using regression. A genome-wide association study (GWAS) was performed on 48 cases and 537 controls. The incidence of MTX neurotoxicity was 7.6% (n=95 of 1,251), at a median of 4 months from ALL diagnosis and 8 days after intravenous or intrathecal MTX. Grade 3 elevation of serum aspartate aminotransferase (P=0.005, odds ratio 2.31 [range, 1.28-4.16]) in induction/consolidation was associated with MTX neurotoxicity, after accounting for the only established risk factor, age ≥10 years. Cumulative incidence of CNS relapse was increased in children where intrathecal MTX was omitted following symptomatic MTX neurotoxicity (n=48) compared to where intrathecal MTX was continued throughout therapy (n=1,174) (P=0.047). Five-year central nervous system relapse-free survival was 89.2 4.6% when intrathecal MTX was ceased compared to 95.4 0.6% when intrathecal MTX was continued. Recurrence of MTX neurotoxicity was low (12.9%) for patients whose intrathecal MTX was continued after their first episode. The GWAS identified single-nucletide polymorphism associated with MTX neurotoxicity near genes regulating neuronal growth, neuronal differentiation and cytoskeletal organization (P<1x10-6). In conclusion, increased serum aspartate aminotransferase and age ≥10 years at diagnosis were independent risk factors for MTX neurotoxicity. Our data do not support cessation of intrathecal MTX after a first MTX neurotoxicity event.

Prospective longitudinal evaluation of treatment-related toxicity and health-related quality of life during the first year of treatment for pediatric acute lymphoblastic leukemia.

BACKGROUND: Pediatric acute lymphoblastic leukemia (ALL) therapy is accompanied by treatment-related toxicities (TRTs) and impaired quality of life. In Australia and New Zealand, children with ALL are treated with either Children's Oncology Group (COG) or international Berlin-Frankfurt-Munster (iBFM) Study Group-based therapy. We conducted a prospective registry study to document symptomatic TRTs (venous thrombosis, neurotoxicity, pancreatitis and bone toxicity), compare TRT outcomes to retrospective TRT data, and measure the impact of TRTs on children's general and cancer-related health-related quality of life (HRQoL) and parents' emotional well-being. METHODS: Parents of children with newly diagnosed ALL were invited to participate in the ASSET (Acute Lymphoblastic Leukaemia Subtypes and Side Effects from Treatment) study and a prospective, longitudinal HRQoL study. TRTs were reported prospectively and families completed questionnaires for general (Healthy Utility Index Mark 3) and cancer specific (Pediatric Quality of Life Inventory (PedsQL)-Cancer Module) health related quality of life as well the Emotion Thermometer to assess emotional well-being. RESULTS: Beginning in 2016, 260 pediatric patients with ALL were enrolled on the TRT registry with a median age at diagnosis of 59 months (range 1-213 months), 144 males (55.4%), majority with Pre-B cell immunophenotype, n = 226 (86.9%), 173 patients (66.5%) treated according to COG platform with relatively equal distribution across risk classification sub-groups. From 2018, 79 families participated in the HRQoL study through the first year of treatment. There were 74 TRT recorded, reflecting a 28.5% risk of developing a TRT. Individual TRT incidence was consistent with previous studies, being 7.7% for symptomatic VTE, 11.9% neurotoxicity, 5.4% bone toxicity and 5.0% pancreatitis. Children's HRQoL was significantly lower than population norms throughout the first year of treatment. An improvement in general HRQoL, measured by the HUI3, contrasted with the lack of improvement in cancer-related HRQoL measured by the PedsQL Cancer Module over the first 12 months. There were no persisting differences in the HRQoL impact of COG compared to iBFM therapy. CONCLUSIONS: It is feasible to prospectively monitor TRT incidence and longitudinal HRQoL impacts during ALL therapy. Early phases of ALL therapy, regardless of treatment platform, result in prolonged reductions in cancer-related HRQoL.

Dissecting the Phenotype and Genotype of PLA2G6-Related Parkinsonism.

BACKGROUND: Complex parkinsonism is the commonest phenotype in late-onset PLA2G6-associated neurodegeneration. OBJECTIVES: The aim of this study was to deeply characterize phenogenotypically PLA2G6-related parkinsonism in the largest cohort ever reported. METHODS: We report 14 new cases of PLA2G6-related parkinsonism and perform a systematic literature review. RESULTS: PLA2G6-related parkinsonism shows a fairly distinct phenotype based on 86 cases from 68 pedigrees. Young onset (median age, 23.0 years) with parkinsonism/dystonia, gait/balance, and/or psychiatric/cognitive symptoms were common presenting features. Dystonia occurred in 69.4%, pyramidal signs in 77.2%, myoclonus in 65.2%, and cerebellar signs in 44.6% of cases. Early bladder overactivity was present in 71.9% of cases. Cognitive impairment affected 76.1% of cases and psychiatric features 87.1%, the latter being an isolated presenting feature in 20.1%. Parkinsonism was levodopa responsive but complicated by early, often severe dyskinesias. Five patients benefited from deep brain stimulation. Brain magnetic resonance imaging findings included cerebral (49.3%) and/or cerebellar (43.2%) atrophy, but mineralization was evident in only 28.1%. Presynaptic dopaminergic terminal imaging was abnormal in all where performed. Fifty-four PLA2G6 mutations have hitherto been associated with parkinsonism, including four new variants reported in this article. These are mainly nontruncating, which may explain the phenotypic heterogeneity of childhood- and late-onset PLA2G6-associated neurodegeneration. In five deceased patients, median disease duration was 13.0 years. Brain pathology in three cases showed mixed Lewy and tau pathology. CONCLUSIONS: Biallelic PLA2G6 mutations cause early-onset parkinsonism associated with dystonia, pyramidal and cerebellar signs, myoclonus, and cognitive impairment. Early psychiatric manifestations and bladder overactivity are common. Cerebro/cerebellar atrophy are frequent magnetic resonance imaging features, whereas brain iron deposition is not. Early, severe dyskinesias are a tell-tale sign. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Factors Associated With Oral Mucositis Severity in Children Who Have Received Chemotherapy.

Oral mucositis (OM) is a major complication for pediatric oncology patients undergoing cancer therapy. This paper aimed to report on the relationship between OM severity and various patient factors as well as to compare 2 scales used to assess OM severity. The severity of 68 separate episodes of OM in 47 pediatric oncology patients who had received chemotherapy was regularly assessed using the Children's International Mucositis Evaluation Scale (ChIMES) and World Health Organization (WHO) scale. The mean time from the start of the patients' chemotherapy block to the onset of OM was 8.4 days (±4.0), the median duration of OM was 7.0 days (4.0, 10.5) and median admission duration was 7.0 days (4.5, 13.5). There was a significant relationship between the severity of OM and the duration of symptoms ( P <0.001), patient's admission length ( P <0.001) and low neutrophil count. With decreasing neutrophil count, the severity of OM and number of pain medications used increased. Neutrophil count recovery coincided with resolution of OM. No significant relationship was found between OM severity and the child's cancer diagnosis. The 2 scales used to measure OM severity showed substantial agreement.

Association of clusterin with the BRI2-derived amyloid molecules ABri and ADan.

Familial British and Danish dementias (FBD and FDD) share striking neuropathological similarities with Alzheimer's disease (AD), including intraneuronal neurofibrillary tangles as well as parenchymal and vascular amyloid deposits. Multiple amyloid associated proteins with still controversial role in amyloidogenesis colocalize with the structurally different amyloid peptides ABri in FBD, ADan in FDD, and Aß in AD. Genetic variants and plasma levels of one of these associated proteins, clusterin, have been identified as risk factors for AD. Clusterin is known to bind soluble Aß in biological fluids, facilitate its brain clearance, and prevent its aggregation. The current work identifies clusterin as the major ABri- and ADan-binding protein and provides insight into the biochemical mechanisms leading to the association of clusterin with ABri and ADan deposits. Mirroring findings in AD, the studies corroborate clusterin co-localization with cerebral parenchymal and vascular amyloid deposits in both disorders. Ligand affinity chromatography with downstream Western blot and amino acid sequence analyses unequivocally identified clusterin as the major ABri- and ADan-binding plasma protein. ELISA highlighted a specific saturable binding of clusterin to ABri and ADan with low nanomolar Kd values within the same range as those previously demonstrated for the clusterin-Aß interaction. Consistent with its chaperone activity, thioflavin T binding assays clearly showed a modulatory effect of clusterin on ABri and ADan aggregation/fibrillization properties. Our findings, together with the known multifunctional activity of clusterin and its modulatory activity on the complex cellular pathways leading to oxidative stress, mitochondrial dysfunction, and the induction of cell death mechanisms - all known pathogenic features of these protein folding disorders - suggests the likelihood of a more complex role and a translational potential for the apolipoprotein in the amelioration/prevention of these pathogenic mechanisms.

CKLF and IL1B transcript levels at diagnosis are predictive of relapse in children with pre-B-cell acute lymphoblastic leukaemia.

Disease relapse is the greatest cause of treatment failure in paediatric B-cell acute lymphoblastic leukaemia (B-ALL). Current risk stratifications fail to capture all patients at risk of relapse. Herein, we used a machine-learning approach to identify B-ALL blast-secreted factors that are associated with poor survival outcomes. Using this approach, we identified a two-gene expression signature (CKLF and IL1B) that allowed identification of high-risk patients at diagnosis. This two-gene expression signature enhances the predictive value of current at diagnosis or end-of-induction risk stratification suggesting the model can be applied continuously to help guide implementation of risk-adapted therapies.

MOBP and HIP1 in multiple system atrophy: New α-synuclein partners in glial cytoplasmic inclusions implicated in the disease pathogenesis.

AIMS: Multiple system atrophy (MSA) is a fatal neurodegenerative disease. Similar to Parkinson's disease (PD), MSA is an α-synucleinopathy, and its pathological hallmark consists of glial cytoplasmic inclusions (GCIs) containing α-synuclein (SNCA) in oligodendrocytes. We previously identified consistent changes in myelin-associated oligodendrocyte basic protein (MOBP) and huntingtin interacting protein 1 (HIP1) DNA methylation status in MSA. We hypothesized that if differential DNA methylation at these loci is mechanistically relevant for MSA, it should have downstream consequences on gene regulation. METHODS: We investigated the relationship between MOBP and HIP1 DNA methylation and mRNA levels in cerebellar white matter from MSA and healthy controls. Additionally, we analysed protein expression using western blotting, immunohistochemistry and proximity ligation assays. RESULTS: We found decreased MOBP mRNA levels significantly correlated with increased DNA methylation in MSA. For HIP1, we found a distinct relationship between DNA methylation and gene expression levels in MSA compared to healthy controls, suggesting this locus may be subjected to epigenetic remodelling in MSA. Although soluble protein levels for MOBP and HIP1 in cerebellar white matter were not significantly different between MSA cases and controls, we found striking differences between MSA and other neurodegenerative diseases, including PD and Huntington's disease. We also found that MOBP and HIP1 are mislocalized into the GCIs in MSA, where they appear to interact with SNCA. CONCLUSIONS: This study supports a role for DNA methylation in downregulation of MOBP mRNA in MSA. Most importantly, the identification of MOBP and HIP1 as new constituents of GCIs emphasizes the relevance of these two loci to the pathogenesis of MSA.

A Clinicopathologic Study of Movement Disorders in Frontotemporal Lobar Degeneration.

BACKGROUND: Despite the considerable overlap with atypical parkinsonism, a systematic characterization of the movement disorders associated with frontotemporal lobar degeneration (FTLD) is lacking. OBJECTIVE: The aim of this study is to provide a detailed description of the phenomenology and neuropathologic correlations of movement disorders in FTLD. METHODS: In this cohort study, movement disorder clinical data were retrospectively collected from medical records of consecutive patients with a postmortem diagnosis of FTLD from the Queen Square Brain Bank between January 2010 and December 2018. At postmortem, neurodegenerative pathologies were systematically evaluated following consensus criteria. Degeneration of the substantia nigra was assessed as a marker of presynaptic dopaminergic parkinsonism using semiquantitative methods. RESULTS: A total of 55 patients (35 men [64%]) were included with median (interquartile range) age at diagnosis of 58.8 (52.6-63.9) years and a disease duration of 9.6 (6.2-12.9) years. Movement disorders were present in 19 (35%) patients without differences among disease subtypes. The most common syndromes were parkinsonism (9 patients [16%]), usually as an additional late feature, and corticobasal syndrome (CBS, 7 patients [13%]), commonly as a presenting feature. Substantia nigra degeneration was present in 37 (67%) patients although it did not show a good clinical correlation with movement disorders. Those with Pick's disease showed milder substantia nigra degeneration and better response to levodopa. CONCLUSIONS: Movement disorders can present in all FTLD subtypes, more commonly as a late additional feature (parkinsonism) or as a presenting symptom (CBS). The underlying pathophysiology is complex and likely to involve structures outside the presynaptic striatonigral system. © 2020 International Parkinson and Movement Disorder Society.

Directed evolution of multiple genomic loci allows the prediction of antibiotic resistance.

Antibiotic development is frequently plagued by the rapid emergence of drug resistance. However, assessing the risk of resistance development in the preclinical stage is difficult. Standard laboratory evolution approaches explore only a small fraction of the sequence space and fail to identify exceedingly rare resistance mutations and combinations thereof. Therefore, new rapid and exhaustive methods are needed to accurately assess the potential of resistance evolution and uncover the underlying mutational mechanisms. Here, we introduce directed evolution with random genomic mutations (DIvERGE), a method that allows an up to million-fold increase in mutation rate along the full lengths of multiple predefined loci in a range of bacterial species. In a single day, DIvERGE generated specific mutation combinations, yielding clinically significant resistance against trimethoprim and ciprofloxacin. Many of these mutations have remained previously undetected or provide resistance in a species-specific manner. These results indicate pathogen-specific resistance mechanisms and the necessity of future narrow-spectrum antibacterial treatments. In contrast to prior claims, we detected the rapid emergence of resistance against gepotidacin, a novel antibiotic currently in clinical trials. Based on these properties, DIvERGE could be applicable to identify less resistance-prone antibiotics at an early stage of drug development. Finally, we discuss potential future applications of DIvERGE in synthetic and evolutionary biology.

Fibrillation and molecular characteristics are coherent with clinical and pathological features of 4-repeat tauopathy caused by MAPT variant G273R.

Microtubule Associated Protein Tau (MAPT) forms proteopathic aggregates in several diseases. The G273R tau mutation, located in the first repeat region, was found by exome sequencing in a patient who presented with dementia and parkinsonism. We herein return to pathological examination which demonstrated tau immunoreactivity in neurons and glia consistent of mixed progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) features. To rationalize the pathological findings, we used molecular biophysics to characterize the mutation in more detail in vitro and in Drosophila. The G273R mutation increases the aggregation propensity of 4-repeat (4R) tau and alters the tau binding affinity towards microtubules (MTs) and F-actin. Tau aggregates in PSP and CBD are predominantly 4R tau. Our data suggest that the G273R mutation induces a shift in pool of 4R tau by lower F-actin affinity, alters the conformation of MT bound 4R tau, while increasing chaperoning of 3R tau by binding stronger to F-actin. The mutation augmented fibrillation of 4R tau initiation in vitro and in glial cells in Drosophila and showed preferential seeding of 4R tau in vitro suggestively causing a late onset 4R tauopathy reminiscent of PSP and CBD.

White matter DNA methylation profiling reveals deregulation of HIP1, LMAN2, MOBP, and other loci in multiple system atrophy.

Multiple system atrophy (MSA) is a fatal late-onset neurodegenerative disease. Although presenting with distinct pathological hallmarks, which in MSA consist of glial cytoplasmic inclusions (GCIs) containing fibrillar α-synuclein in oligodendrocytes, both MSA and Parkinson's disease are α-synucleinopathies. Pathologically, MSA can be categorized into striatonigral degeneration (SND), olivopontocerebellar atrophy (OPCA) or mixed subtypes. Despite extensive research, the regional vulnerability of the brain to MSA pathology remains poorly understood. Genetic, epigenetic and environmental factors have been proposed to explain which brain regions are affected by MSA, and to what extent. Here, we explored for the first time epigenetic changes in post-mortem brain tissue from MSA cases. We conducted a case-control study, and profiled DNA methylation in white mater from three brain regions characterized by severe-to-mild GCIs burden in the MSA mixed subtype (cerebellum, frontal lobe and occipital lobe). Our genome-wide approach using Illumina MethylationEPIC arrays and a powerful cross-region analysis identified 157 CpG sites and 79 genomic regions where DNA methylation was significantly altered in the MSA mixed-subtype cases. HIP1, LMAN2 and MOBP were amongst the most differentially methylated loci. We replicated these findings in an independent cohort and further demonstrated that DNA methylation profiles were perturbed in MSA mixed subtype, and also to variable degrees in the other pathological subtypes (OPCA and SND). Finally, our co-methylation network analysis revealed several molecular signatures (modules) significantly associated with MSA (disease status and pathological subtypes), and with neurodegeneration in the cerebellum. Importantly, the co-methylation module having the strongest association with MSA included a CpG in SNCA, the gene encoding α-synuclein. Altogether, our results provide the first evidence for DNA methylation changes contributing to the molecular processes altered in MSA, some of which are shared with other neurodegenerative diseases, and highlight potential novel routes for diagnosis and therapeutic interventions.