Biology subjects

Goldman, J. E.

Publications and source records attributed to Goldman, J. E..

8 recordsLinked to original sources

bioRxiv2024

The landscape of glial pathology and T-call response in Parkinson's substantia nigra

Parkinsons Disease (PD) is a progressive neurodegenerative disease that leads to debilitating movement disorders and often dementia. Recent evidence, including identification of specific peripheral T-cell receptor sequences, indicates that the adaptive immune response is associated with disease pathogenesis. However, the properties of T-cells in the brain regions where neurons degenerate are not well characterized. We have analyzed the identities and interactions of T-cells in PD in post-mortem brain tissue using single nucleus RNA sequencing, spatial transcriptomics and T-cell receptor sequencing. We found that T-cells in the substantia nigra of PD brain donors exhibit a CD8+ resident memory phenotype, increased clonal expansion, and altered spatial relationships with astrocytes, myeloid cells, and endothelial cells. We also describe regional differences in astrocytic responses to neurodegeneration. Our findings nominate potential molecular and cellular candidates that allow a deeper understanding of the pathophysiology of neurodegeneration in PD. Together, our work represents a major single nucleus and spatial transcriptional resource for the fields of neurodegeneration and PD.

neuroscience↗

bioRxiv2023

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. Here, we employed a multi-omic approach including single nucleus RNAseq (snRNAseq), bulk RNAseq, lipidomics, HTT gene CAG repeat length measurements, and multiplexed immunofluorescence on post-mortem brain tissue from multiple brain regions of HD and control donors. We defined a signature of genes that is driven by CAG repeat length and found it enriched in astrocytic and microglial genes. Moreover, weighted gene correlation network analysis showed loss of connectivity of astrocytic and microglial modules in HD and identified modules that correlated with CAG-repeat length which further implicated inflammatory pathways and metabolism. We performed lipidomic analysis of HD and control brains and identified several lipid species that correlate with HD grade, including ceramides and very long chain fatty acids. Integration of lipidomics and bulk transcriptomics identified a consensus gene signature that correlates with HD grade and HD lipidomic abnormalities and implicated the unfolded protein response pathway. Because astrocytes are critical for brain lipid metabolism and play important roles in regulating inflammation, we analyzed our snRNAseq dataset with an emphasis on astrocyte pathology. We found two main astrocyte types that spanned multiple brain regions; these types correspond to protoplasmic astrocytes, and fibrous-like - CD44-positive, astrocytes. HD pathology was differentially associated with these cell types in a region-specific manner. One protoplasmic astrocyte cluster showed high expression of metallothionein genes, the depletion of this cluster positively correlated with the depletion of vulnerable medium spiny neurons in the caudate nucleus. We confirmed that metallothioneins were increased in cingulate HD astrocytes but were unchanged or even decreased in caudate astrocytes. We combined existing genome-wide association studies (GWAS) with a GWA study conducted on HD patients from the original Venezuelan cohort and identified a single-nucleotide polymorphism in the metallothionein gene locus associated with delayed age of onset. Functional studies found that metallothionein overexpressing astrocytes are better able to buffer glutamate and were neuroprotective of patient-derived directly reprogrammed HD MSNs as well as against rotenone-induced neuronal death in vitro. Finally, we found that metallothionein-overexpressing astrocytes increased the phagocytic activity of microglia in vitro and increased the expression of genes involved in fatty acid binding. Together, we identified an astrocytic phenotype that is regionally-enriched in less vulnerable brain regions that can be leveraged to protect neurons in HD.

neuroscience↗

bioRxiv2022

Border-associated macrophages mediate the neuroinflammatory response in an alpha-synuclein model of Parkinson disease

Dopaminergic cell loss due to the accumulation of -syn is a core feature of PD pathogenesis. Neuroinflammation specifically induced by -syn has been shown to exacerbate neurodegeneration, yet the role of CNS resident macrophages in this process remains unclear. We found that a specific subset of CNS resident macrophages, border-associated macrophages (BAMs), play an essential role in mediating -syn related neuroinflammation due to their unique role as the antigen presenting cells necessary to initiate a CD4 T cell response. Surprisingly, the loss of MHCII antigen presentation on microglia had no effect on neuroinflammation. Furthermore, -syn expression led to an expansion in BAM numbers and a unique damage-associated activation state. Through a combinatorial approach of single-cell RNA sequencing and depletion experiments, we found that BAMs played an essential role in immune cell recruitment, infiltration, and antigen presentation. Furthermore, BAMs were identified in post-mortem PD brain in close proximity to T cells. These results point to a critical role for BAMs in mediating PD pathogenesis through their essential role in the orchestration of the -syn-mediated neuroinflammatory response.

neuroscience↗

bioRxiv2022

Single nuclei RNAseq analysis of HD mouse models and human brain reveals impaired oligodendrocyte maturation and potential role for thiamine metabolism

The complexity of affected brain regions and cell types is a challenge for Huntingtons disease (HD) treatment. Here we used single nucleus RNA sequencing (snRNAseq) to investigate mechanism of pathology in the cortex and striatum from R6/2 mice at 8 and 12w and in three regions of human HD post-mortem tissue. We identified cell type-specific and cell agnostic signatures and found changes suggesting oligodendrocytes (OLs) and oligodendrocyte precursors (OPCs) were arrested in intermediate maturation states. OL-lineage regulators OLIG1 and OLIG2 were negatively correlated with CAG length in human OPCs, and ATACseq analysis of HD mouse NeuN-negative cells showed decreased accessibility of sites regulated by OL maturation genes. Glucose and lipid metabolism were implicated in abnormal cell maturation and PRKCE and Thiamine Pyrophosphokinase 1 were identified as central genes. High dose thiamine/biotin treatment of R6/1 HD mice to target thiamine metabolism not only restored OL maturation, but also rescued pathology in neurons. These findings reveal insights into HD OL pathology that spans multiple brain regions and link OL maturation deficits to abnormal thiamine metabolism.

neuroscience↗

bioRxiv2022

TMEM106B is increased in Multiple Sclerosis plaques, and deletion causes accumulation of lipid after demyelination

During inflammatory, demyelinating diseases such as multiple sclerosis (MS) axonal damage is prevalent early in the disease course. Axonal damage includes swellings, defects in transport, and failure to clear damaged intracellular proteins, all of which affect recovery and compromise the integrity of neurons and remyelination. Autophagy and the clearance of damaged cell components by the proteasome are important for the maintenance of normal cellular turnover; and the restoration of cellular homeostasis. The gradual accumulation of insoluble proteins in the brain is known to impair recovery from several neurodegenerative diseases. In this study, we used mass spectrometry to identify insoluble proteins within high-speed, mercaptoethanol/sarcosyl-insoluble pellets from purified white matter plaques isolated from the brains of individuals with MS. We determined that insoluble transmembrane protein106B (TMEM106B), expressed in neurons and glia and normally lysosomal-associated, is increased in MS plaques relative to normal-appearing white matter from individuals with Alzheimers disease and non-neurologic controls. We found that decreased TMEM106B protein in mice results in significant axonal damage and lipid droplet accumulation in the spinal cord following chronic myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalomyelitis. When TMEM106Bt/t mice were treated with cuprizone to experimentally induce demyelination, a significant increase in lipid deposition was observed in the corpus callosum of TMEM106Bt/t mice post-cuprizone withdrawal. Our study shows that the brain and spinal cord from challenged TMEM106Bt/t mice accumulate OilRedO+/Perilipin2+ lipid droplets. We postulate that increased insolubility of TMEM106B in MS plaques limits debris clearance by the lysosome which over time contributes to failed remyelination and axonal defects. Abbreviated AbstractTransmembrane protein106B (TMEM106B), a lysosome-associated protein, is significantly less soluble in multiple sclerosis plaques than in white matter controls. Decreased TMEM106B produces significant axonal damage and lipid accumulation in mouse models of demyelinating diseases. TMEM106B insolubility and likely loss of function may limit lysosome transport and contribute to CNS pathology.

neuroscience↗

bioRxiv2022

SARS-CoV-2 infection results in lasting and systemic perturbations post recovery

SARS-CoV-2 has been found capable of inducing prolonged pathologies collectively referred to as Long-COVID. To better understand this biology, we compared the short- and long-term systemic responses in the golden hamster following either SARS-CoV-2 or influenza A virus (IAV) infection. While SARS-CoV-2 exceeded IAV in its capacity to cause injury to the lung and kidney, the most significant changes were observed in the olfactory bulb (OB) and olfactory epithelium (OE) where inflammation was visible beyond one month post SARS-CoV-2 infection. Despite a lack of detectable virus, OB/OE demonstrated microglial and T cell activation, proinflammatory cytokine production, and interferon responses that correlated with behavioral changes. These findings could be corroborated through sequencing of individuals who recovered from COVID-19, as sustained inflammation in OB/OE tissue remained evident months beyond disease resolution. These data highlight a molecular mechanism for persistent COVID-19 symptomology and characterize a small animal model to develop future therapeutics.

microbiology↗

bioRxiv2021

Disruption of nuclear architecture as a cause of COVID-19 induced anosmia

Olfaction relies on a coordinated partnership between odorant flow and neuronal communication. Disruption in our ability to detect odors, or anosmia, has emerged as a hallmark symptom of infection with SARS-CoV-2, yet the mechanism behind this abrupt sensory deficit remains elusive. Here, using molecular evaluation of human olfactory epithelium (OE) from subjects succumbing to COVID-19 and a hamster model of SARS-CoV-2 infection, we discovered widespread downregulation of olfactory receptors (ORs) as well as key components of their signaling pathway. OR downregulation likely represents a non-cell autonomous effect, since SARS-CoV-2 detection in OSNs is extremely rare both in human and hamster OEs. A likely explanation for the reduction of OR transcription is the striking reorganization of nuclear architecture observed in the OSN lineage, which disrupts multi-chromosomal compartments regulating OR expression in humans and hamsters. Our experiments uncover a novel molecular mechanism by which a virus with a very selective tropism can elicit persistent transcriptional changes in cells that evade it, contributing to the severity of COVID-19.

neuroscience↗

bioRxiv2019

Single-nucleus RNA-seq identifies Huntington disease astrocyte states

Huntington Disease (HD) is an inherited movement disorder caused by expanded CAG repeats in the Huntingtin gene. We have used single nucleus RNASeq (snRNASeq) to uncover cellular phenotypes that change in the disease, investigating single cell gene expression in cingulate cortex of patients with HD and comparing the gene expression to that of patients with no neurological disease. In this study, we focused on astrocytes, although we found significant gene expression differences in neurons, oligodendrocytes, and microglia as well. In particular, the gene expression profiles of astrocytes in HD showed multiple signatures, varying in phenotype from cells that had markedly upregulated metallothionein and heat shock genes, but had not completely lost the expression of genes associated with normal protoplasmic astrocytes, to astrocytes that had substantially upregulated GFAP and had lost expression of many normal protoplasmic astrocyte genes as well as metallothionein genes. When compared to astrocytes in control samples, astrocyte signatures in HD also showed downregulated expression of a number of genes, including several associated with protoplasmic astrocyte function and lipid synthesis. Thus, HD astrocytes appeared in variable transcriptional phenotypes, and could be divided into several different \"states\", defined by patterns of gene expression. Ultimately, this study begins to fill the knowledge gap of single cell gene expression in HD and provide a more detailed understanding of the variation in changes in gene expression during astrocyte \"reactions\" to the disease.

neuroscience↗