scholarly journals Unraveling the Spatiotemporal Distribution of VPS13A in the Mouse Brain

2021 ◽  
Vol 22 (23) ◽  
pp. 13018
Author(s):  
Esther García-García ◽  
Nerea Chaparro-Cabanillas ◽  
Albert Coll-Manzano ◽  
Maria Carreras-Caballé ◽  
Albert Giralt ◽  
...  
Keyword(s):  
Mouse Brain ◽  
Cortical Neurons ◽  
Expression Profiles ◽  
Cholinergic Neurons ◽  
Relevant Information ◽  
Cellular Level ◽  
Spatiotemporal Distribution ◽  
Loss Of Function ◽  
Vacuolar Protein

Loss-of-function mutations in the human vacuolar protein sorting the 13 homolog A (VPS13A) gene cause Chorea-acanthocytosis (ChAc), with selective degeneration of the striatum as the main neuropathologic feature. Very little is known about the VPS13A expression in the brain. The main objective of this work was to assess, for the first time, the spatiotemporal distribution of VPS13A in the mouse brain. We found VPS13A expression present in neurons already in the embryonic stage, with stable levels until adulthood. VPS13A mRNA and protein distributions were similar in the adult mouse brain. We found a widespread VPS13A distribution, with the strongest expression profiles in the pons, hippocampus, and cerebellum. Interestingly, expression was weak in the basal ganglia. VPS13A staining was positive in glutamatergic, GABAergic, and cholinergic neurons, but rarely in glial cells. At the cellular level, VPS13A was mainly located in the soma and neurites, co-localizing with both the endoplasmic reticulum and mitochondria. However, it was not enriched in dendritic spines or the synaptosomal fraction of cortical neurons. In vivo pharmacological modulation of the glutamatergic, dopaminergic or cholinergic systems did not modulate VPS13A concentration in the hippocampus, cerebral cortex, or striatum. These results indicate that VPS13A has remarkable stability in neuronal cells. Understanding the distinct expression pattern of VPS13A can provide relevant information to unravel pathophysiological hallmarks of ChAc.

scholarly journals Essential Roles in Development and Pigmentation for the Drosophila Copper Transporter DmATP7

2006 ◽  
Vol 17 (1) ◽  
pp. 475-484 ◽  
Author(s):  
Melanie Norgate ◽  
Esther Lee ◽  
Adam Southon ◽  
Ashley Farlow ◽  
Philip Batterham ◽  
...  
Keyword(s):  
Copper Homeostasis ◽  
Cellular Level ◽  
Loss Of Function ◽  
Neuronal Function ◽  
Copper Transporter ◽  
Disease Phenotypes ◽  
In Vivo Analysis ◽  
Cellular Copper ◽  
P Type

Defects in the mammalian Menkes and Wilson copper transporting P-type ATPases cause severe copper homeostasis disease phenotypes in humans. Here, we find that DmATP7, the sole Drosophila orthologue of the Menkes and Wilson genes, is vital for uptake of copper in vivo. Analysis of a DmATP7 loss-of-function allele shows that DmATP7 is essential in embryogenesis, early larval development, and adult pigmentation and is probably required for copper uptake from the diet. These phenotypes are analogous to those caused by mutation in the mouse and human Menkes genes, suggesting that like Menkes, DmATP7 plays at least two roles at the cellular level: delivering copper to cuproenzymes required for pigmentation and neuronal function and removing excess cellular copper via facilitated efflux. DmATP7 displays a dynamic and unexpected expression pattern in the developing embryo, implying novel functions for this copper pump and the lethality observed in DmATP7 mutant flies is the earliest seen for any copper homeostasis gene.

scholarly journals Striatal seeding of protofibrillar alpha-synuclein causes cortical hyperreactivity in behaving mice

2020 ◽  
Author(s):  
Sonja Blumenstock ◽  
Fanfan Sun ◽  
Petar Marinković ◽  
Carmelo Sgobio ◽  
Sabine Liebscher ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Alpha Synuclein ◽  
Cellular Level ◽  
Neuronal Function ◽  
Two Photon ◽  
Neuron Function ◽  
The Impact ◽  
Self Aggregation ◽  
Intrastriatal Injection

SummaryAlpha-synucleinopathies are characterized by self-aggregation of the protein alpha-synuclein (a-syn), causing alterations on the molecular and cellular level. To unravel the impact of transneuronal spreading and templated misfolding of a-syn on the microcircuitry of remotely connected brain areas, we investigated cortical neuron function in awake mice 9 months after a single intrastriatal injection of a-syn preformed fibrils (PFFs), using in vivo two-photon calcium imaging. We found altered function of layer 2/3 cortical neurons in somatosensory cortex (S1) of PFF-inoculated mice, as witnessed by an enhanced response to whisking and increased synchrony, accompanied by a decrease in baseline Ca2+ levels. Stereological analyses revealed a reduction in GAD67-positive inhibitory cells in S1 in PFF-injected brains. These findings point to a disturbed excitation/inhibition balance as an important pathomechanism in alpha-synucleinopathies and demonstrate a clear association between the spread of toxic proteins and the initiation of altered neuronal function in remotely connected areas.

scholarly journals c-Jun NH2-terminal Kinase (JNK)-interacting Protein-3 (JIP3) Regulates Neuronal Axon Elongation in a Kinesin- and JNK-dependent Manner

2013 ◽  
Vol 288 (20) ◽  
pp. 14531-14543 ◽  
Author(s):  
Tao Sun ◽  
Nuo Yu ◽  
Lu-Kai Zhai ◽  
Na Li ◽  
Chao Zhang ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Hippocampal Neurons ◽  
Molecular Mechanisms ◽  
Neuronal Development ◽  
Dependent Manner ◽  
Loss Of Function ◽  
Anterograde Transport ◽  
Interacting Protein ◽  
Axon Elongation

The development of neuronal polarity is essential for the establishment of the accurate patterning of neuronal circuits in the brain. However, little is known about the underlying molecular mechanisms that control rapid axon elongation during neuronal development. Here, we report that c-Jun NH2-terminal kinase (JNK)-interacting protein-3 (JIP3) is highly expressed at axon tips during the critical period for axon development. Using gain- and loss-of-function approaches, immunofluorescence analysis, and in utero electroporation, we find that JIP3 can enhance axon elongation in primary hippocampal neurons and cortical neurons in vivo. We further demonstrate that JIP3 promotes axon elongation in a kinesin- and JNK-dependent manner using several deletion mutants of JIP3. Next, we demonstrate that the successful transportation of JIP3 to axon tips by kinesin is a prerequisite for enhancing JNK phosphorylation in this area and therefore promotes axon elongation, constituting a novel mechanism for coupling JIP3 anterograde transport with JNK signaling at the distal axons and axon elongation. Finally, our immunofluorescence data suggest that the activation of JNK at axon tips facilitates axon elongation by modulating cofilin activity and actin filament dynamics. These findings may have important implications for our understanding of neuronal axon elongation during development.

scholarly journals Cell Type-Specific Survey of Epigenetic Modifications by Tandem Chromatin Immunoprecipitation Sequencing

2017 ◽  
Author(s):  
Mari Mito ◽  
Mitsutaka Kadota ◽  
Kaori Tanaka ◽  
Yasuhide Furuta ◽  
Kuniya Abe ◽  
...  
Keyword(s):  
Chromatin Immunoprecipitation ◽  
Cortical Neurons ◽  
Expression Profiles ◽  
Cell Types ◽  
Epigenetic Modifications ◽  
Specific Cell ◽  
Cell Type ◽  
Chromatin Immunoprecipitation Sequencing ◽  
Cell Type Specific

AbstractBackgroundThe nervous system of higher eukaryotes is composed of numerous types of neurons and glia that together orchestrate complex neuronal responses. However, this complex pool of cells typically poses analytical challenges in investigating gene expression profiles and their epigenetic basis for specific cell types. Here, we developed a novel method that enables cell type-specific analyses of epigenetic modifications using tandem chromatin immunoprecipitation sequencing (tChIP-Seq).ResultsFLAG-tagged histone H2B, a constitutive chromatin component, was first expressed in Camk2a-positive pyramidal cortical neurons and used to purify chromatin in a cell type-specific manner. Subsequent chromatin immunoprecipitation using antibodies against H3K4me3—an active promoter mark—allowed us to survey neuron-specific coding and non-coding transcripts. Indeed, tChIP-Seq identified hundreds of genes associated with neuronal functions and genes with unknown functions expressed in cortical neurons.ConclusionstChIP-Seq thus provides a versatile approach to investigating the epigenetic modifications of particular cell types in vivo.

scholarly journals Rapid Fragmentation of the Endoplasmic Reticulum in Cortical Neurons of the Mouse Brain in situ Following Cardiac Arrest

2011 ◽  
Vol 31 (8) ◽  
pp. 1663-1667 ◽  
Author(s):  
Krzysztof Kucharz ◽  
Tadeusz Wieloch ◽  
Håkan Toresson
Keyword(s):  
Endoplasmic Reticulum ◽  
Cardiac Arrest ◽  
Mouse Brain ◽  
Cortical Neurons ◽  
Laser Scanning ◽  
Pyramidal Neurons ◽  
Hippocampal Slices ◽  
Primary Cultures ◽  
Laser Scanning Microscopy

Neuronal endoplasmic reticulum (ER), continuous from soma to dendritic spines, undergoes rapid fragmentation in response to N-methyl-D-aspartate (NMDA) receptor stimulation in hippocampal slices and neuronal primary cultures. Here, we show that ER fragments in the mouse brain following cardiac arrest (CA) induced brain ischemia. The ER structure was assessed in vivo in cortical pyramidal neurons in transgenic mice expressing ER-targeted GFP using two-photon laser scanning microscopy with fluorescence recovery after photobleaching (FRAP). Endoplasmic reticulum fragmentation occurred 1 to 2 minutes after CA and once induced, fragmentation was rapid (< 15 seconds). We propose that acute ER fragmentation may be a protective response against severe ischemic stress.

scholarly journals Little Helpers or Mean Rogue—Role of Microglia in Animal Models of Amyotrophic Lateral Sclerosis

2021 ◽  
Vol 22 (3) ◽  
pp. 993
Author(s):  
Hilal Cihankaya ◽  
Carsten Theiss ◽  
Veronika Matschke
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Motor Neurons ◽  
Disease Onset ◽  
Cellular Level ◽  
Chromosome 9 ◽  
Common Denominator ◽  
Vacuolar Protein ◽  
Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is one of the most common neurodegenerative diseases, causing degeneration of both upper and lower motor neurons in the central nervous system (CNS). ALS patients suffer from hyperreflexia, spasticity, paralysis and muscle atrophy and typically die due to respiratory failure 1–5 years after disease onset. In addition to the degeneration of motor neurons on the cellular level, ALS has been associated with neuroinflammation, such as microgliosis. Microglial activation in ALS can either be protective or degenerative to the neurons. Among others, mutations in superoxide dismutase 1 (SOD1), chromosome 9 open reading frame 72 (C9Orf72), transactive response DNA binding protein (TDP) 43 and vacuolar protein sorting-associated protein 54 (VPS54) genes have been associated with ALS. Here, we describe the dual role and functionality of microglia in four different in vivo ALS models and search for the lowest common denominator with respect to the role of microglia in the highly heterogeneous disease of ALS.

scholarly journals AP-4 mediated ATG9A sorting underlies axonal and autophagosome biogenesis defects in a mouse model of AP-4 deficiency syndrome

2017 ◽  
Author(s):  
Davor Ivankovic ◽  
Guillermo López-Doménech ◽  
James Drew ◽  
Sharon A. Tooze ◽  
Josef T. Kittler
Keyword(s):  
Mouse Model ◽  
Transmembrane Protein ◽  
Adaptor Protein ◽  
Deficiency Syndrome ◽  
Cellular Level ◽  
Loss Of Function ◽  
Golgi Network ◽  
Autophagosome Maturation

AbstractAdaptor protein (AP) complexes have critical roles in transmembrane protein sorting. AP-4 remains poorly understood in the brain despite its loss of function leading to a hereditary spastic paraplegia termed AP-4 deficiency syndrome. Here we demonstrate that knockout (KO) of AP-4 in a mouse model leads to thinning of the corpus callosum and ventricular enlargement, anatomical defects previously described in patients. At the cellular level, we find that AP-4 KO leads to defects in axonal extension and branching, in addition to aberrant distal swellings. Interestingly, we show that ATG9A, a key protein in autophagosome maturation, is critically dependent on AP-4 for its sorting from the trans-golgi network. Failure of AP-4 mediated ATG9A sorting results in its dramatic retention in the trans-golgi network in vitro and in vivo leading to a specific reduction of the axonal pool of ATG9A. As a result, autophagosome biogenesis is aberrant in the axon of AP-4 deficient neurons. The specific alteration to axonal integrity and axonal autophagosome maturation in AP-4 knockout neurons may underpin the pathology of AP-4 deficiency.

scholarly journals TRANSCRIPTIONAL PROFILE AND CHROMATIN ACCESSIBILITY IN ZEBRAFISH MELANOCYTES AND MELANOMA TUMORS

2021 ◽  
Author(s):  
Eva T Kramer ◽  
Paula M Godoy ◽  
Charles K Kaufman
Keyword(s):  
Gene Expression ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Melanoma Cells ◽  
Chromatin Accessibility ◽  
Rna Seq ◽  
Loss Of Function ◽  
Human Melanocytes ◽  
Melanoma Model

Abstract Transcriptional and epigenetic characterization of melanocytes and melanoma cells isolated from their in vivo context promises to unveil key differences between these developmentally related normal and cancer cell populations. We therefore engineered an enhanced Danio rerio (zebrafish) melanoma model with fluorescently labeled melanocytes to allow for isolation of normal (wild type) and premalignant (BRAFV600E-mutant) populations for comparison to fully transformed BRAFV600E-mutant, p53 loss-of-function melanoma cells. Using fluorescence activated cell sorting to isolate these populations, we performed high-quality RNA-seq and ATAC-seq on sorted zebrafish melanocytes vs. melanoma cells, which we provide as a resource here. Melanocytes had consistent transcriptional and accessibility profiles, as did melanoma cells. Comparing melanocytes and melanoma, we note 4,128 differentially expressed genes and 56,936 differentially accessible regions with overall gene expression profiles analogous to human melanocytes and the pigmentation melanoma subtype. Combining the RNA-seq and ATAC-seq data surprisingly revealed that increased chromatin accessibility did not always correspond with increased gene expression, suggesting that though there is widespread dysregulation in chromatin accessibility in melanoma, there is a potentially more refined gene expression program driving cancerous melanoma. This data serves as a resource to identify candidate regulators of the normal vs. diseased states in a genetically controlled in vivo context.

scholarly journals Upregulated Collagen COL10A1 Remodels the Extracellular Matrix and Promotes Malignant Progression in Lung Adenocarcinoma

2020 ◽  
Vol 10 ◽  
Author(s):  
Yingkuan Liang ◽  
Wenjie Xia ◽  
Te Zhang ◽  
Bing Chen ◽  
Hui Wang ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Lung Adenocarcinoma ◽  
Tumor Progression ◽  
Expression Profiles ◽  
Ectopic Expression ◽  
Loss Of Function ◽  
Mechanism Study ◽  
Cell Progression

Collagens are major components of the ECM in various organs, including the lungs. Ectopic expression of collagens can regulate the tumor progression and disease outcome through remodeling of the extracellular matrix (ECM). However, it remains largely unexplored whether collagens are involved in the tumor progression of lung adenocarcinoma (LUAD). Analysis of three LUAD transcriptional expression profiles showed that COL10A1 mRNA expression was up-regulated and associated with poor prognosis. Gain- and loss-of-function studies were performed to observe that up-regulated COL10A1 promotes LUAD cell proliferation and invasion in vitro and in vivo. In molecular mechanism study, we found that COL10A1 interacts with DDR2 and affects the downstream FAK signaling pathway to regulate LUAD cell progression. The expression of COL10A1 on tissue microarray (TMA) was also measured to explore the association between COL10A1 expression and patient outcome. The results addressed that COL10A1 is up-regulated and positively correlated with lymph node metastasis in lung adenocarcinoma, and the COL10A1 expression is also an independent prognostic factor. In summary, the up-regulated COL10A1 remodels the ECM and the COL10A1/DDR2/FAK axis regulates the proliferation and metastasis of LUAD cells, implying that COL10A1 is a promising therapeutic target and prognostic marker for LUAD patients.

scholarly journals Phosphorylation of CRMP2 by Cdk5 Regulates Dendritic Spine Development of Cortical Neuron in the Mouse Hippocampus

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Xiaohua Jin ◽  
Kodai Sasamoto ◽  
Jun Nagai ◽  
Yuki Yamazaki ◽  
Kenta Saito ◽  
...  
Keyword(s):  
Mouse Brain ◽  
Dendritic Spines ◽  
Dendritic Spine ◽  
Cortical Neurons ◽  
Hippocampal Neurons ◽  
Molecular Mechanisms ◽  
Brain Functions ◽  
Spine Development ◽  
Mouse Hippocampus

Proper density and morphology of dendritic spines are important for higher brain functions such as learning and memory. However, our knowledge about molecular mechanisms that regulate the　development and maintenance of dendritic spines is limited. We recently reported that cyclin-dependent kinase 5 (Cdk5) is required for the development and maintenance of dendritic spines of cortical neurons in the mouse brain. Previousin vitrostudies have suggested the involvement of Cdk5 substrates in the formation of dendritic spines; however, their role in spine development has not been testedin vivo. Here, we demonstrate that Cdk5 phosphorylates collapsin response mediator protein 2 (CRMP2) in the dendritic spines of cultured hippocampal neurons andin vivoin the mouse brain. When we eliminated CRMP2 phosphorylation inCRMP2KI/KImice, the densities of dendritic spines significantly decreased in hippocampal CA1 pyramidal neurons in the mouse brain. These results indicate that phosphorylation of CRMP2 by Cdk5 is important for dendritic spine development in cortical neurons in the mouse hippocampus.

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