A cross-disease resource of living human microglia identifies disease-enriched subsets and tool compounds recapitulating microglial states.

Human microglia play a pivotal role in neurological diseases, but we still have an incomplete understanding of microglial heterogeneity, which limits the development of targeted therapies directly modulating their state or function. Here, we use single-cell RNA sequencing to profile 215,680 live human microglia from 74 donors across diverse neurological diseases and CNS regions. We observe a central divide between oxidative and heterocyclic metabolism and identify microglial subsets associated with antigen presentation, motility and proliferation.

Multi-omic analysis of Huntington's disease reveals a compensatory astrocyte state.

The mechanisms underlying the selective regional vulnerability to neurodegeneration in Huntington's disease (HD) have not been fully defined. To explore the role of astrocytes in this phenomenon, we used single-nucleus and bulk RNAseq, lipidomics, HTT gene CAG repeat-length measurements, and multiplexed immunofluorescence on HD and control post-mortem brains. We identified genes that correlated with CAG repeat length, which were enriched in astrocyte genes, and lipidomic signatures that implicated poly-unsaturated fatty acids in sensitizing neurons to cell death.

Liquid biopsy-based circulating tumour (ct)DNA analysis of a spectrum of myeloid and lymphoid malignancies yields clinically actionable results.

Aims: Liquid biopsy (LBx)-based next-generation sequencing (NGS) of circulating tumour DNA (ctDNA) can facilitate molecular profiling of haematopoietic neoplasms (HNs), particularly when tissue-based NGS is infeasible.

Methods And Results: We studied HN LBx samples tested with FoundationOne Liquid CDx, FoundationOne Liquid, or FoundationACT between July 2016 and March 2022. We identified 271 samples: 89 non-Hodgkin lymphoma (NHL), 43 plasma-cell neoplasm (PCN), 41 histiocytoses, 27 myelodysplastic syndrome (MDS), 25 diffuse large B-cell lymphoma (DLBCL), 22 myeloproliferative neoplasm (MPN), 14 Hodgkin lymphoma (HL), and 10 acute myeloid leukaemia (AML).

Multi-OMIC analysis of Huntington disease reveals a neuroprotective astrocyte state.

Huntington disease (HD) is an incurable neurodegenerative disease characterized by neuronal loss and astrogliosis. One hallmark of HD is the selective neuronal vulnerability of striatal medium spiny neurons. To date, the underlying mechanisms of this selective vulnerability have not been fully defined.

Brain tumors in United States military veterans.

Background: Comprehensive analysis of brain tumor incidence and survival in the Veteran population has been lacking.

Methods: Veteran data were obtained from the Veterans Health Administration (VHA) Medical Centers via VHA Corporate Data Warehouse. Brain tumor statistics on the overall US population were generated from the Central Brain Tumor Registry of the US data.

Precision diagnosis and staging of TDP-43 proteinopathies: harnessing the power of artificial intelligence.

This scientific commentary refers to ‘Data-driven neuropathological staging and subtyping of TDP-43 proteinopathies’ by Young . (https://doi.org/10.

Patterns of TDP-43 Deposition in Brains with LRRK2 G2019S Mutations.

Objective: To assess for TDP-43 deposits in brains with and without a LRRK2 G2019S mutation.

Background: LRRK2 G2019S mutations have been associated with parkinsonism and a wide range of pathological findings. There are no systematic studies examining the frequency and extent of TDP-43 deposits in neuropathological samples from LRRK2 G2019S carriers.

Cerebrospinal fluid: A unique source of circulating tumor DNA with broad clinical applications.

Malignancies involving the central nervous system present unique challenges for diagnosis and monitoring due to the difficulties and risks of direct biopsies and the low specificity and/or sensitivity of other techniques for assessment. In recent years, liquid biopsy of the cerebrospinal fluid (CSF) has emerged as a convenient alternative that combines minimal invasiveness with the ability to detect disease-defining or therapeutically actionable genetic alterations from circulating tumor DNA (ctDNA). Since CSF can be obtained by lumbar puncture, or an established ventricular access device at multiple time points, ctDNA analysis enables initial molecular characterization and longitudinal monitoring throughout a patient's disease course, promoting optimization of treatment regimens.

Huntington disease oligodendrocyte maturation deficits revealed by single-nucleus RNAseq are rescued by thiamine-biotin supplementation.

The complexity of affected brain regions and cell types is a challenge for Huntington's disease (HD) treatment. Here we use single nucleus RNA sequencing to investigate molecular pathology in the cortex and striatum from R6/2 mice and human HD post-mortem tissue. We identify cell type-specific and -agnostic signatures suggesting oligodendrocytes (OLs) and oligodendrocyte precursors (OPCs) are arrested in intermediate maturation states.

The distribution and density of Huntingtin inclusions across the Huntington disease neocortex: regional correlations with Huntingtin repeat expansion independent of pathologic grade.

Huntington disease is characterized by progressive neurodegeneration, especially of the striatum, and the presence of polyglutamine huntingtin (HTT) inclusions. Although HTT inclusions are most abundant in the neocortex, their neocortical distribution and density in relation to the extent of CAG repeat expansion in the HTT gene and striatal pathologic grade have yet to be formally established. We immunohistochemically studied 65 brains with a pathologic diagnosis of Huntington disease to investigate the cortical distributions and densities of HTT inclusions within the calcarine (BA17), precuneus (BA7), motor (BA4) and prefrontal (BA9) cortices; in 39 of these brains, a p62 immunostain was used for comparison.

Neuropathological Findings in a Case of Parkinsonism and Developmental Delay Associated with a Monoallelic Variant in PLXNA1.

Background: PLXNA1 encodes for Plexin-A, a transmembrane protein expressed in the developing nervous system. Mutations in this gene have been associated with developmental delay but have not been previously associated with the development of parkinsonism.

Objectives: To describe the case of a 38-year-old patient with developmental delay who developed parkinsonism later in life.

Pituitary corticotroph tumour with adrenocortical cells: A distinct clinicopathologic entity with unique morphology and methylation profile.

We describe a rare TPIT-positive corticotroph PitNET that is admixed with SF1-positive adrenocortical cells. This dimorphous population of cells showed no colocalisation between TPIT and SF1 by immunofluorescence, and an adrenocortical choristoma was favoured. Methylation array analysis revealed a novel methylation profile in relation to other pituitary neoplasms.

R1441G but not G2019S mutation enhances LRRK2 mediated Rab10 phosphorylation in human peripheral blood neutrophils.

Heterozygous gain-of-kinase function variants in LRRK2 (leucine-rich repeat kinase 2) cause 1-2% of all cases of Parkinson's disease (PD) albeit with incomplete and age-dependent penetrance. All pathogenic LRRK2 mutations reside within the two catalytic domains of LRRK2-either in its kinase domain (e.g.

COVID-19 neuropathology at Columbia University Irving Medical Center/New York Presbyterian Hospital.

Many patients with SARS-CoV-2 infection develop neurological signs and symptoms; although, to date, little evidence exists that primary infection of the brain is a significant contributing factor. We present the clinical, neuropathological and molecular findings of 41 consecutive patients with SARS-CoV-2 infections who died and underwent autopsy in our medical centre. The mean age was 74 years (38-97 years), 27 patients (66%) were male and 34 (83%) were of Hispanic/Latinx ethnicity.

Pathogenic Huntingtin Repeat Expansions in Patients with Frontotemporal Dementia and Amyotrophic Lateral Sclerosis.

We examined the role of repeat expansions in the pathogenesis of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) by analyzing whole-genome sequence data from 2,442 FTD/ALS patients, 2,599 Lewy body dementia (LBD) patients, and 3,158 neurologically healthy subjects. Pathogenic expansions (range, 40-64 CAG repeats) in the huntingtin (HTT) gene were found in three (0.12%) patients diagnosed with pure FTD/ALS syndromes but were not present in the LBD or healthy cohorts.