Paraoxonase-1 and -3 Protein Expression in the Brain of the Tg2576 Mouse Model of Alzheimer’s Disease

Background: Brain oxidative lipid damage and inflammation are common in neurodegenerative diseases such as Alzheimer’s disease (AD). Paraoxonase-1 and -3 (PON1 and PON3) protein expression was demonstrated in tissue with no PON1 or PON3 gene expression. In the present study, we examine differences in PON1 and PON3 protein expression in the brain of a mouse model of AD. Methods: we used peroxidase- and fluorescence-based immunohistochemistry in five brain regions (olfactory bulb, forebrain, posterior midbrain, hindbrain and cerebellum) of transgenic (Tg2576) mice with the Swedish mutation (KM670/671NL) responsible for a familial form of AD and corresponding wild-type mice. Results: We found intense PON1 and PON3-positive staining in star-shaped cells surrounding Aβ plaques in all the studied Tg2576 mouse-brain regions. Although we could not colocalize PON1 and PON3 with astrocytes (star-shaped cells in the brain), we found some PON3 colocalization with microglia. Conclusions: These results suggest that (1) PON1 and PON3 cross the blood–brain barrier in discoidal high-density lipoproteins (HDLs) and are transferred to specific brain-cell types; and (2) PON1 and PON3 play an important role in preventing oxidative stress and lipid peroxidation in particular brain-cell types (likely to be glial cells) in AD pathology and potentially in other neurodegenerative diseases as well.

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SARS-CoV-2 receptor and entry genes are expressed by sustentacular cells in the human olfactory neuroepithelium

10.1101/2020.03.31.013268 ◽

2020 ◽

Cited By ~ 31

Author(s):

Leon Fodoulian ◽

Joel Tuberosa ◽

Daniel Rossier ◽

Madlaina Boillat ◽

Chenda Kan ◽

...

Keyword(s):

Sensory System ◽

Cell Types ◽

Sensory Epithelium ◽

Brain Cell ◽

Rna Seq ◽

Angiotensin Converting Enzyme 2 ◽

Sustentacular Cells ◽

The Brain ◽

Brain Cell Types ◽

Human And Mouse

AbstractVarious reports indicate an association between COVID-19 and anosmia, suggesting an infection of the olfactory sensory epithelium, and thus a possible direct virus access to the brain. To test this hypothesis, we generated RNA-seq libraries from human olfactory neuroepithelia, in which we found substantial expression of the genes coding for the virus receptor angiotensin-converting enzyme-2 (ACE2), and for the virus internalization enhancer TMPRSS2. We analyzed a human olfactory single-cell RNA-seq dataset and determined that sustentacular cells, which maintain the integrity of olfactory sensory neurons, express ACE2 and TMPRSS2. We then observed that the ACE2 protein was highly expressed in a subset of sustentacular cells in human and mouse olfactory tissues. Finally, we found ACE2 transcripts in specific brain cell types, both in mice and humans. Sustentacular cells thus represent a potential entry door for SARS-CoV-2 in a neuronal sensory system that is in direct connection with the brain.

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Brain Microenvironment Heterogeneity: Potential Value for Brain Tumors

Frontiers in Oncology ◽

10.3389/fonc.2021.714428 ◽

2021 ◽

Vol 11 ◽

Author(s):

Laura Álvaro-Espinosa ◽

Ana de Pablos-Aragoneses ◽

Manuel Valiente ◽

Neibla Priego

Keyword(s):

Brain Tumors ◽

Single Cell ◽

Brain Injuries ◽

Clinical Work ◽

Cell Types ◽

Brain Cell ◽

Brain Disorders ◽

Brain Connectome ◽

The Brain ◽

Brain Cell Types

Uncovering the complexity of the microenvironment that emerges in brain disorders is key to identify potential vulnerabilities that might help challenging diseases affecting this organ. Recently, genomic and proteomic analyses, especially at the single cell level, have reported previously unrecognized diversity within brain cell types. The complexity of the brain microenvironment increases during disease partly due to the immune infiltration from the periphery that contributes to redefine the brain connectome by establishing a new crosstalk with resident brain cell types. Within the rewired brain ecosystem, glial cell subpopulations are emerging hubs modulating the dialogue between the Immune System and the Central Nervous System with important consequences in the progression of brain tumors and other disorders. Single cell technologies are crucial not only to define and track the origin of disease-associated cell types, but also to identify their molecular similarities and differences that might be linked to specific brain injuries. These altered molecular patterns derived from reprogramming the healthy brain into an injured organ, might provide a new generation of therapeutic targets to challenge highly prevalent and lethal brain disorders that remain incurable with unprecedented specificity and limited toxicities. In this perspective, we present the most relevant clinical and pre-clinical work regarding the characterization of the heterogeneity within different components of the microenvironment in the healthy and injured brain with a special interest on single cell analysis. Finally, we discuss how understanding the diversity of the brain microenvironment could be exploited for translational purposes, particularly in primary and secondary tumors affecting the brain.

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Establishment and Preliminary Characterization of Three Astrocytic Cells Lines Obtained from Primary Rat Astrocytes by Sub-Cloning

Genes ◽

10.3390/genes11121502 ◽

2020 ◽

Vol 11 (12) ◽

pp. 1502

Author(s):

Fabio Caradonna ◽

Gabriella Schiera ◽

Carlo Maria Di Liegro ◽

Vincenzo Vitale ◽

Ilenia Cruciata ◽

...

Keyword(s):

Cell Lines ◽

Cell Types ◽

Brain Parenchyma ◽

Brain Cell ◽

The Other ◽

Cellular Events ◽

Rat Astrocytes ◽

The Brain ◽

Brain Cell Types

Gliomas are complex and heterogeneous tumors that originate from the glial cells of the brain. The malignant cells undergo deep modifications of their metabolism, and acquire the capacity to invade the brain parenchyma and to induce epigenetic modifications in the other brain cell types. In spite of the efforts made to define the pathology at the molecular level, and to set novel approaches to reach the infiltrating cells, gliomas are still fatal. In order to gain a better knowledge of the cellular events that accompany astrocyte transformation, we developed three increasingly transformed astrocyte cell lines, starting from primary rat cortical astrocytes, and analyzed them at the cytogenetic and epigenetic level. In parallel, we also studied the expression of the differentiation-related H1.0 linker histone variant to evaluate its possible modification in relation with transformation. We found that the most modified astrocytes (A-FC6) have epigenetic and chromosomal alterations typical of cancer, and that the other two clones (A-GS1 and A-VV5) have intermediate properties. Surprisingly, the differentiation-specific somatic histone H1.0 steadily increases from the normal astrocytes to the most transformed ones. As a whole, our results suggest that these three cell lines, together with the starting primary cells, constitute a potential model for studying glioma development.

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Genetic identification Of brain cell types underlying schizophrenia

10.1101/145466 ◽

2017 ◽

Cited By ~ 10

Author(s):

Nathan G. Skene ◽

Julien Bryois ◽

Trygve E. Bakken ◽

Gerome Breen ◽

James J Crowley ◽

...

Keyword(s):

Pyramidal Cells ◽

Cell Types ◽

Brain Cell ◽

Common Variant ◽

Genetic Identification ◽

Medium Spiny Neurons ◽

Gene Sets ◽

The Common ◽

The Brain ◽

Brain Cell Types

AbstractWith few exceptions, the marked advances in knowledge about the genetic basis for schizophrenia have not converged on findings that can be confidently used for precise experimental modeling. Applying knowledge of the cellular taxonomy of the brain from single-cell RNA-sequencing, we evaluated whether the genomic loci implicated in schizophrenia map onto specific brain cell types. The common variant genomic results consistently mapped to pyramidal cells, medium spiny neurons, and certain interneurons but far less consistently to embryonic, progenitor, or glial cells. These enrichments were due to distinct sets of genes specifically expressed in each of these cell types. Many of the diverse gene sets associated with schizophrenia (including antipsychotic targets) implicate the same brain cell types. Our results provide a parsimonious explanation: the common-variant genetic results for schizophrenia point at a limited set of neurons, and the gene sets point to the same cells. While some of the genetic risk is associated with GABAergic interneurons, this risk largely does not overlap with that from projecting cells.

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The Regulation of Astrocytic Glutamate Transporters in Health and Neurodegenerative Diseases

International Journal of Molecular Sciences ◽

10.3390/ijms21249607 ◽

2020 ◽

Vol 21 (24) ◽

pp. 9607

Author(s):

Alison C. Todd ◽

Giles E. Hardingham

Keyword(s):

Neurodegenerative Diseases ◽

Excitatory Amino Acid ◽

Glutamate Transporters ◽

Cell Types ◽

Brain Cell ◽

Amino Acid Transporters ◽

Extracellular Glutamate ◽

Nervous System Function ◽

Low Levels ◽

Brain Cell Types

The astrocytic glutamate transporters excitatory amino acid transporters 1 and 2 (EAAT1 and EAAT2) play a key role in nervous system function to maintain extracellular glutamate levels at low levels. In physiology, this is essential for the rapid uptake of synaptically released glutamate, maintaining the temporal fidelity of synaptic transmission. However, EAAT1/2 hypo-expression or hypo-function are implicated in several disorders, including epilepsy and neurodegenerative diseases, as well as being observed naturally with aging. This not only disrupts synaptic information transmission, but in extremis leads to extracellular glutamate accumulation and excitotoxicity. A key facet of EAAT1/2 expression in astrocytes is a requirement for signals from other brain cell types in order to maintain their expression. Recent evidence has shown a prominent role for contact-dependent neuron-to-astrocyte and/or endothelial cell-to-astrocyte Notch signalling for inducing and maintaining the expression of these astrocytic glutamate transporters. The relevance of this non-cell-autonomous dependence to age- and neurodegenerative disease-associated decline in astrocytic EAAT expression is discussed, plus the implications for disease progression and putative therapeutic strategies.

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High Vulnerability of Oligodendrocytes to Oxidative Stress Induced by Ultrafine Urban Particles

Antioxidants ◽

10.3390/antiox10010004 ◽

2020 ◽

Vol 10 (1) ◽

pp. 4

Author(s):

Ji Young Kim ◽

Jin-Hee Kim ◽

Yong-Dae Kim ◽

Je Hoon Seo

Keyword(s):

Oxidative Stress ◽

White Matter ◽

Cortical Neurons ◽

Cell Types ◽

Brain Cell ◽

Brain Cells ◽

Control Group ◽

Fluoro Jade B ◽

The Brain ◽

Brain Cell Types

Oligodendrocytes, myelin-forming cells in the brain, are vulnerable to oxidative stress. Recent work indicates that air pollution causes demyelinating diseases such as multiple sclerosis. However, little is known about the mechanism of toxicity of ultrafine particulate matters (PMs) to oligodendrocytes. Here, we aimed to determine whether oligodendrocyte precursor cells (OPCs) and mature oligodendrocytes (mOLs) are more vulnerable to ultrafine urban PMs (uf-UPs) than other types of brain cells and damage to adult OPCs and mOLs in the mouse brain exposed to uf-UPs. For in vitro experiments, following exposure to various concentrations (2, 20, and 200 μg/mL) of uf-UPs, we measured survival rates, the amount of reactive oxygen species (ROS), and the total antioxidant capacities (TACs) of brain cells isolated from neonatal Sprague-Dawley rats. For animal experiments, after a four-week exposure to a uf-UP suspension (20 μL, 0.4 mg/mL), we enumerated the number of damaged cells and typed damaged cells in the white matter of the cerebellum of uf-UP-exposed mice. MTT assays and Hoechst staining demonstrated that OPCs and mOLs were more vulnerable to uf-UP-induced damage than astrocytes and cortical neurons at 2, 20, and 200 μg/mL of uf-UPs examined in this study (p < 0.05). Damage to OPCs and mOLs depended on uf-UP concentration. DCF assays and DHE staining indicated that the amount of ROS generated in OPCs and mOLs was significantly higher than in other brain cell types (p < 0.05). In contrast, TAC values in OPCs and mOLs were significantly lower than those of other brain cell types (p < 0.05). Fluoro-Jade B (FJB)-positive cells in the cerebellar white matter of the uf-UP-exposed group were significantly greater in number relative to the control group. Double immunofluorescence indicated that FJB-positive cells are NG2-positive adult OPCs and carbon anhydrase II-positive mOLs. Taken together, our findings suggest that oxidative stress induced by uf-UPs in the brain impairs adult OPCs and mOLs, causing demyelination and reducing the capacity for remyelination.

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Hypoxia, Acidification and Inflammation: Partners in Crime in Parkinson’s Disease Pathogenesis?

Immuno ◽

10.3390/immuno1020006 ◽

2021 ◽

Vol 1 (2) ◽

pp. 78-90

Author(s):

Johannes Burtscher ◽

Grégoire P. Millet

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Neurodegenerative Diseases ◽

Current Knowledge ◽

Cell Types ◽

Brain Cell ◽

Special Focus ◽

Molecular Alterations ◽

Research Fields

Like in other neurodegenerative diseases, protein aggregation, mitochondrial dysfunction, oxidative stress and neuroinflammation are hallmarks of Parkinson’s disease (PD). Differentiating characteristics of PD include the central role of α-synuclein in the aggregation pathology, a distinct vulnerability of the striato-nigral system with the related motor symptoms, as well as specific mitochondrial deficits. Which molecular alterations cause neurodegeneration and drive PD pathogenesis is poorly understood. Here, we summarize evidence of the involvement of three interdependent factors in PD and suggest that their interplay is likely a trigger and/or aggravator of PD-related neurodegeneration: hypoxia, acidification and inflammation. We aim to integrate the existing knowledge on the well-established role of inflammation and immunity, the emerging interest in the contribution of hypoxic insults and the rather neglected effects of brain acidification in PD pathogenesis. Their tight association as an important aspect of the disease merits detailed investigation. Consequences of related injuries are discussed in the context of aging and the interaction of different brain cell types, in particular with regard to potential consequences on the vulnerability of dopaminergic neurons in the substantia nigra. A special focus is put on the identification of current knowledge gaps and we emphasize the importance of related insights from other research fields, such as cancer research and immunometabolism, for neurodegeneration research. The highlighted interplay of hypoxia, acidification and inflammation is likely also of relevance for other neurodegenerative diseases, despite disease-specific biochemical and metabolic alterations.

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Location Matters: Navigating Regional Heterogeneity of the Neurovascular Unit

Frontiers in Cellular Neuroscience ◽

10.3389/fncel.2021.696540 ◽

2021 ◽

Vol 15 ◽

Author(s):

Louis-Philippe Bernier ◽

Clément Brunner ◽

Azzurra Cottarelli ◽

Matilde Balbi

Keyword(s):

Brain Function ◽

Energy Demand ◽

Neurovascular Unit ◽

Cell Types ◽

Brain Regions ◽

Regional Heterogeneity ◽

Regional Specialization ◽

Multiple Cell ◽

Cellular Components ◽

The Brain

The neurovascular unit (NVU) of the brain is composed of multiple cell types that act synergistically to modify blood flow to locally match the energy demand of neural activity, as well as to maintain the integrity of the blood-brain barrier (BBB). It is becoming increasingly recognized that the functional specialization, as well as the cellular composition of the NVU varies spatially. This heterogeneity is encountered as variations in vascular and perivascular cells along the arteriole-capillary-venule axis, as well as through differences in NVU composition throughout anatomical regions of the brain. Given the wide variations in metabolic demands between brain regions, especially those of gray vs. white matter, the spatial heterogeneity of the NVU is critical to brain function. Here we review recent evidence demonstrating regional specialization of the NVU between brain regions, by focusing on the heterogeneity of its individual cellular components and briefly discussing novel approaches to investigate NVU diversity.

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Localization of migraine susceptibility genes in human brain by single-cell RNA sequencing

Cephalalgia ◽

10.1177/0333102418762476 ◽

2018 ◽

Vol 38 (13) ◽

pp. 1976-1983 ◽

Cited By ~ 5

Author(s):

William Renthal

Keyword(s):

Human Brain ◽

Single Cell ◽

Rna Sequencing ◽

Expression Profiles ◽

Cell Types ◽

Susceptibility Genes ◽

Brain Cell ◽

Cell Type ◽

Single Cell Rna Sequencing ◽

Brain Cell Types

Background Migraine is a debilitating disorder characterized by severe headaches and associated neurological symptoms. A key challenge to understanding migraine has been the cellular complexity of the human brain and the multiple cell types implicated in its pathophysiology. The present study leverages recent advances in single-cell transcriptomics to localize the specific human brain cell types in which putative migraine susceptibility genes are expressed. Methods The cell-type specific expression of both familial and common migraine-associated genes was determined bioinformatically using data from 2,039 individual human brain cells across two published single-cell RNA sequencing datasets. Enrichment of migraine-associated genes was determined for each brain cell type. Results Analysis of single-brain cell RNA sequencing data from five major subtypes of cells in the human cortex (neurons, oligodendrocytes, astrocytes, microglia, and endothelial cells) indicates that over 40% of known migraine-associated genes are enriched in the expression profiles of a specific brain cell type. Further analysis of neuronal migraine-associated genes demonstrated that approximately 70% were significantly enriched in inhibitory neurons and 30% in excitatory neurons. Conclusions This study takes the next step in understanding the human brain cell types in which putative migraine susceptibility genes are expressed. Both familial and common migraine may arise from dysfunction of discrete cell types within the neurovascular unit, and localization of the affected cell type(s) in an individual patient may provide insight into to their susceptibility to migraine.

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STAB: a spatio-temporal cell atlas of the human brain

Nucleic Acids Research ◽

10.1093/nar/gkaa762 ◽

2020 ◽

Vol 49 (D1) ◽

pp. D1029-D1037

Author(s):

Liting Song ◽

Shaojun Pan ◽

Zichao Zhang ◽

Longhao Jia ◽

Wei-Hua Chen ◽

...

Keyword(s):

Human Brain ◽

Single Cell ◽

Temporal Dynamics ◽

Cell Types ◽

Brain Regions ◽

Molecular Characteristics ◽

Great Effort ◽

Brain Functions ◽

Spatio Temporal ◽

The Brain

Abstract The human brain is the most complex organ consisting of billions of neuronal and non-neuronal cells that are organized into distinct anatomical and functional regions. Elucidating the cellular and transcriptome architecture underlying the brain is crucial for understanding brain functions and brain disorders. Thanks to the single-cell RNA sequencing technologies, it is becoming possible to dissect the cellular compositions of the brain. Although great effort has been made to explore the transcriptome architecture of the human brain, a comprehensive database with dynamic cellular compositions and molecular characteristics of the human brain during the lifespan is still not available. Here, we present STAB (a Spatio-Temporal cell Atlas of the human Brain), a database consists of single-cell transcriptomes across multiple brain regions and developmental periods. Right now, STAB contains single-cell gene expression profiling of 42 cell subtypes across 20 brain regions and 11 developmental periods. With STAB, the landscape of cell types and their regional heterogeneity and temporal dynamics across the human brain can be clearly seen, which can help to understand both the development of the normal human brain and the etiology of neuropsychiatric disorders. STAB is available at http://stab.comp-sysbio.org.

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