Nuclear accumulation of CHMP7 initiates nuclear pore complex injury and subsequent TDP-43 dysfunction in sporadic and familial ALS

2021 ◽  
Vol 13 (604) ◽  
pp. eabe1923
Author(s):  
Alyssa N. Coyne ◽  
Victoria Baskerville ◽  
Benjamin L. Zaepfel ◽  
Dennis W. Dickson ◽  
Frank Rigo ◽  
...  
Keyword(s):  
Nuclear Pore Complex ◽  
Nuclear Export ◽  
Induced Pluripotent Stem Cell ◽  
Nuclear Accumulation ◽  
Nuclear Pore ◽  
Human Motor Cortex ◽  
Sporadic Als ◽  
Human Neurons ◽  
Induced Pluripotent ◽  
And Function

Alterations in the components [nucleoporins (Nups)] and function of the nuclear pore complex (NPC) have been implicated as contributors to the pathogenesis of genetic forms of neurodegeneration including C9orf72 amyotrophic lateral sclerosis/frontotemporal dementia (ALS/FTD). We hypothesized that Nup alterations and the consequential loss of NPC function may lie upstream of TDP-43 dysfunction and mislocalization widely observed in ALS, FTD, and related neurodegenerative diseases. Here, we provide evidence that CHMP7, a critical mediator of NPC quality control, is increased in nuclei of C9orf72 and sporadic ALS induced pluripotent stem cell (iPSC)–derived spinal neurons (iPSNs) and postmortem human motor cortex before the emergence of Nup alterations. Inhibiting the nuclear export of CHMP7 triggered Nup reduction and TDP-43 dysfunction and pathology in human neurons. Knockdown of CHMP7 alleviated disease-associated Nup alterations, deficits in Ran GTPase localization, defects in TDP-43–associated mRNA expression, and downstream glutamate-induced neuronal death. Thus, our data support a role for altered CHMP7-mediated Nup homeostasis as a prominent initiating pathological mechanism for familial and sporadic ALS and highlight the potential for CHMP7 as therapeutic target.

scholarly journals The ESCRT-III protein VPS4, but not CHMP4B or CHMP2B, is pathologically increased in familial and sporadic ALS neuronal nuclei

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Alyssa N. Coyne ◽  
Jeffrey D. Rothstein
Keyword(s):  
Nuclear Pore Complex ◽  
Mammalian Cells ◽  
Nuclear Accumulation ◽  
Nuclear Pore ◽  
Dependent Manner ◽  
Structured Illumination Microscopy ◽  
Neuronal Nuclei ◽  
Complex Injury ◽  
Sporadic Als ◽  
Human Neurons

AbstractNuclear pore complex injury has recently emerged as an early and significant contributor to familial and sporadic ALS disease pathogenesis. However, the molecular events leading to this pathological phenomenon characterized by the reduction of specific nucleoporins from neuronal nuclear pore complexes remain largely unknown. This is due in part to a lack of knowledge regarding the biological pathways and proteins underlying nuclear pore complex homeostasis specifically in human neurons. We have recently uncovered that aberrant nuclear accumulation of the ESCRT-III protein CHMP7 initiates nuclear pore complex in familial and sporadic ALS neurons. In yeast and non-neuronal mammalian cells, nuclear relocalization of CHMP7 has been shown to recruit the ESCRT-III proteins CHMP4B, CHMP2B, and VPS4 to facilitate nuclear pore complex and nuclear envelope repair and homeostasis. Here, using super resolution structured illumination microscopy, we find that neither CHMP4B nor CHMP2B are increased in ALS neuronal nuclei. In contrast, VPS4 expression is significantly increased in ALS neuronal nuclei prior to the emergence of nuclear pore injury in a CHMP7 dependent manner. However, unlike our prior CHMP7 knockdown studies, impaired VPS4 function does not mitigate alterations to the NPC and the integral transmembrane nucleoporin POM121. Collectively our data suggest that while alterations in VPS4 subcellular localization appear to be coincident with nuclear pore complex injury, therapeutic efforts to mitigate this pathogenic cascade should be targeted towards upstream events such as the nuclear accumulation of CHMP7 as we have previously described.

scholarly journals RAE1 Is a Shuttling mRNA Export Factor That Binds to a GLEBS-like NUP98 Motif at the Nuclear Pore Complex through Multiple Domains

1999 ◽  
Vol 145 (2) ◽  
pp. 237-254 ◽  
Author(s):  
Colin E.J. Pritchard ◽  
Maarten Fornerod ◽  
Lawryn H. Kasper ◽  
Jan M.A. van Deursen
Keyword(s):  
Nuclear Pore Complex ◽  
Nuclear Export ◽  
Mrna Export ◽  
Nuclear Accumulation ◽  
Nuclear Pore ◽  
Xenopus Laevis Oocytes ◽  
Binding Motif ◽  
Binding Studies ◽  
Direct Role ◽  
Multiple Domains

Gle2p is implicated in nuclear export of poly(A)+ RNA and nuclear pore complex (NPC) structure and distribution in Saccharomyces cerevisiae. Gle2p is anchored at the nuclear envelope (NE) via a short Gle2p-binding motif within Nup116p called GLEBS. The molecular mechanism by which Gle2p and the Gle2p–Nup116p interaction function in mRNA export is unknown. Here we show that RAE1, the mammalian homologue of Gle2p, binds to a GLEBS-like NUP98 motif at the NPC through multiple domains that include WD-repeats and a COOH-terminal non–WD-repeat extension. This interaction is direct, as evidenced by in vitro binding studies and chemical cross-linking. Microinjection experiments performed in Xenopus laevis oocytes demonstrate that RAE1 shuttles between the nucleus and the cytoplasm and is exported from the nucleus in a temperature-dependent and RanGTP-independent manner. Docking of RAE1 to the NE is highly dependent on new mRNA synthesis. Overexpression of the GLEBS-like motif also inhibits NE binding of RAE1 and induces nuclear accumulation of poly(A)+ RNA. Both effects are abrogated either by the introduction of point mutations in the GLEBS-like motif or by overexpression of RAE1, indicating a direct role for RAE1 and the NUP98–RAE1 interaction in mRNA export. Together, our data suggest that RAE1 is a shuttling transport factor that directly contributes to nuclear export of mRNAs through its ability to anchor to a specific NUP98 motif at the NPC.

scholarly journals Sac3 Is an mRNA Export Factor That Localizes to Cytoplasmic Fibrils of Nuclear Pore Complex

2003 ◽  
Vol 14 (3) ◽  
pp. 836-847 ◽  
Author(s):  
Elissa P. Lei ◽  
Charlene A. Stern ◽  
Birthe Fahrenkrog ◽  
Heike Krebber ◽  
Terence I. Moy ◽  
...  
Keyword(s):  
Nuclear Pore Complex ◽  
Nuclear Export ◽  
Synthetic Lethality ◽  
Mrna Export ◽  
Nuclear Accumulation ◽  
Nuclear Pore ◽  
Messenger Rnas ◽  
Loss Of Function ◽  
Synthetic Lethal ◽  
Starting Point

In eukaryotes, mRNAs are transcribed in the nucleus and exported to the cytoplasm for translation to occur. Messenger RNAs complexed with proteins referred to as ribonucleoparticles are recognized for nuclear export in part by association with Mex67, a keySaccharomyces cerevisiae mRNA export factor and homolog of human TAP/NXF1. Mex67, along with its cofactor Mtr2, is thought to promote ribonucleoparticle translocation by interacting directly with components of the nuclear pore complex (NPC). Herein, we show that the nuclear pore-associated protein Sac3 functions in mRNA export. Using a mutant allele of MTR2 as a starting point, we have identified a mutation in SAC3 in a screen for synthetic lethal interactors. Loss of function of SAC3 causes a strong nuclear accumulation of mRNA and synthetic lethality with a number of mRNA export mutants. Furthermore, Sac3 can be coimmunoprecipitated with Mex67, Mtr2, and other factors involved in mRNA export. Immunoelectron microscopy analysis shows that Sac3 localizes exclusively to cytoplasmic fibrils of the NPC. Finally, Mex67 accumulates at the nuclear rim when SAC3 is mutated, suggesting that Sac3 functions in Mex67 translocation through the NPC.

scholarly journals Fragile X syndrome patient-derived neurons developing in the mouse brain show FMR1 -dependent phenotypes

2021 ◽  
Author(s):  
Marine A Krzisch ◽  
Hao A Wu ◽  
Bingbing Yuan ◽  
Troy W. Whitfield ◽  
X. Shawn Liu ◽  
...  
Keyword(s):  
Fragile X Syndrome ◽  
Neuronal Development ◽  
Fragile X ◽  
In Vitro Models ◽  
Synaptic Activity ◽  
Human Neurons ◽  
Induced Pluripotent ◽  
And Function ◽  
The Brain

Abnormal neuronal development in Fragile X syndrome (FXS) is poorly understood. Data on FXS patients remain scarce and FXS animal models have failed to yield successful therapies. In vitro models do not fully recapitulate the morphology and function of human neurons. Here, we co-injected neural precursor cells (NPCs) from FXS patient-derived and corrected isogenic control induced pluripotent stem cells into the brain of neonatal immune-deprived mice. The transplanted cells populated the brain and a proportion differentiated into neurons and glial cells. Single-cell RNA sequencing of transplanted cells revealed upregulated excitatory synaptic transmission and neuronal differentiation pathways in FXS neurons. Immunofluorescence analyses showed accelerated maturation of FXS neurons after an initial delay. Additionally, increased percentages of Arc- and Egr1-positive FXS neurons and wider dendritic protrusions of mature FXS striatal medium spiny neurons pointed to an increase in synaptic activity and synaptic strength as compared to control. This transplantation approach provides new insights into the alterations of neuronal development in FXS by facilitating physiological development of cells in a 3D context, and could be used to test new therapeutic compounds correcting neuronal development defects in FXS.

Abstract 379: Effects of Microgravity on Human Induced Pluripotent Stem Cell-Derived Cardiomyocyte Structure and Function

2018 ◽  
Vol 123 (Suppl_1) ◽  
Author(s):  
Alexa Wnorowski ◽  
Arun Sharma ◽  
Haodong Chen ◽  
Haodi Wu ◽  
Ning-Yi Shao ◽  
...  
Keyword(s):  
Stem Cell ◽  
Pluripotent Stem Cell ◽  
Induced Pluripotent Stem Cell ◽  
Structure And Function ◽  
Induced Pluripotent ◽  
And Function

scholarly journals Inhalational delivery of induced pluripotent stem cell secretome improves postpneumonectomy lung structure and function

2020 ◽  
Vol 129 (5) ◽  
pp. 1051-1061
Author(s):  
D. Merrill Dane ◽  
Khoa Cao ◽  
Yu-An Zhang ◽  
Kemp H. Kernstine ◽  
Amiq Gazdhar ◽  
...  
Keyword(s):  
Pluripotent Stem Cells ◽  
Induced Pluripotent Stem Cell ◽  
Repeated Administration ◽  
Control Treatment ◽  
Surgical Removal ◽  
Adaptive Responses ◽  
Lung Structure ◽  
Secretory Products ◽  
Induced Pluripotent ◽  
And Function

To examine whether the secreted products of human induced pluripotent stem cells (iPSCs) facilitate innate adaptive responses following loss of lung tissue, adult dogs underwent surgical removal of one lung, then received repeated administration of iPSC secretory products via inhalational delivery compared with control treatment. Inhalation of iPSC secretory products enhanced capillary formation and beneficial structural remodeling in the remaining lung, leading to improved lung function.

scholarly journals Genome Wide Analysis Points towards Subtype-Specific Diseases in Different Genetic Forms of Amyotrophic Lateral Sclerosis

2020 ◽  
Vol 21 (18) ◽  
pp. 6938
Author(s):  
Banaja P. Dash ◽  
Marcel Naumann ◽  
Jared Sterneckert ◽  
Andreas Hermann
Keyword(s):  
Motor Neurons ◽  
Individualized Medicine ◽  
Induced Pluripotent Stem Cell ◽  
Kegg Pathways ◽  
Amyotropic Lateral Sclerosis ◽  
Sporadic Als ◽  
Apparent Death ◽  
Induced Pluripotent ◽  
Simplex Virus ◽  
Lateral Sclerosis

Amyotropic lateral sclerosis (ALS) is a lethally progressive and irreversible neurodegenerative disease marked by apparent death of motor neurons present in the spinal cord, brain stem and motor cortex. While more and more gene mutants being established for genetic ALS, the vast majority suffer from sporadic ALS (>90%). It has been challenging, thus, to model sporadic ALS which is one reason why the underlying pathophysiology remains elusive and has stalled the development of therapeutic strategies of this progressive motor neuron disease. To further unravel these pathological signaling pathways, human induced pluripotent stem cell (hiPSCs)-derived motor neurons (MNs) from FUS- and SOD1 ALS patients and healthy controls were systematically compared to independent published datasets. Here through this study we created a gene profile of ALS by analyzing the DEGs, the Kyoto encyclopedia of Genes and Genomes (KEGG) pathways, the interactome and the transcription factor profiles (TF) that would identify altered molecular/functional signatures and their interactions at both transcriptional (mRNAs) and translational levels (hub proteins and TFs). Our findings suggest that FUS and SOD1 may develop from dysregulation in several unique pathways and herpes simplex virus (HSV) infection was among the topmost predominant cellular pathways connected to FUS and not to SOD1. In contrast, SOD1 is mainly characterized by alterations in the metabolic pathways and alterations in the neuroactive-ligand–receptor interactions. This suggests that different genetic ALS forms are singular diseases rather than part of a common spectrum. This is important for patient stratification clearly pointing towards the need for individualized medicine approaches in ALS.

scholarly journals Monoclonal Antibodies to NTF2 Inhibit Nuclear Protein Import by Preventing Nuclear Translocation of the GTPase Ran

2000 ◽  
Vol 11 (2) ◽  
pp. 703-719 ◽  
Author(s):  
Susanne M. Steggerda ◽  
Ben E. Black ◽  
Bryce M. Paschal
Keyword(s):  
Nuclear Pore Complex ◽  
Nuclear Import ◽  
Protein Import ◽  
Nuclear Translocation ◽  
Living Cells ◽  
Nuclear Accumulation ◽  
Nuclear Pore ◽  
Permeabilized Cells ◽  
Dependent Protein

Nuclear transport factor 2 (NTF2) is a soluble transport protein originally identified by its ability to stimulate nuclear localization signal (NLS)-dependent protein import in digitonin-permeabilized cells. NTF2 has been shown to bind nuclear pore complex proteins and the GDP form of Ran in vitro. Recently, it has been reported that NTF2 can stimulate the accumulation of Ran in digitonin-permeabilized cells. Evidence that NTF2 directly mediates Ran import or that NTF2 is required to maintain the nuclear concentration of Ran in living cells has not been obtained. Here we show that cytoplasmic injection of anti-NTF2 mAbs resulted in a dramatic relocalization of Ran to the cytoplasm. This provides the first evidence that NTF2 regulates the distribution of Ran in vivo. Moreover, anti-NTF2 mAbs inhibited nuclear import of both Ran and NLS-containing protein in vitro, suggesting that NTF2 stimulates NLS-dependent protein import by driving the nuclear accumulation of Ran. We also show that biotinylated NTF2-streptavidin microinjected into the cytoplasm accumulated at the nuclear envelope, indicating that NTF2 can target a binding partner to the nuclear pore complex. Taken together, our data show that NTF2 is an essential regulator of the Ran distribution in living cells and that NTF2-mediated Ran nuclear import is required for NLS-dependent protein import.

scholarly journals The importin-beta family member Crm1p bridges the interaction between Rev and the nuclear pore complex during nuclear export

1997 ◽  
Vol 7 (10) ◽  
pp. 767-775 ◽  
Author(s):  
Megan Neville ◽  
Francoise Stutz ◽  
Linda Lee ◽  
Laura I Davis ◽  
Michael Rosbash
Keyword(s):  
Family Member ◽  
Nuclear Pore Complex ◽  
Nuclear Export ◽  
Nuclear Pore ◽  
Importin Beta

scholarly journals The nuclear basket proteins Mlp1p and Mlp2p are part of a dynamic interactome including Esc1p and the proteasome

2013 ◽  
Vol 24 (24) ◽  
pp. 3920-3938 ◽  
Author(s):  
Mario Niepel ◽  
Kelly R. Molloy ◽  
Rosemary Williams ◽  
Julia C. Farr ◽  
Anne C. Meinema ◽  
...  
Keyword(s):  
Gene Expression ◽  
Nuclear Pore Complex ◽  
Nuclear Export ◽  
Regulation Of Gene Expression ◽  
Nuclear Pore ◽  
Docking Site ◽  
Discrete Structure ◽  
Transport Channel ◽  
Macromolecular Complexes ◽  
Nuclear Stability

The basket of the nuclear pore complex (NPC) is generally depicted as a discrete structure of eight protein filaments that protrude into the nucleoplasm and converge in a ring distal to the NPC. We show that the yeast proteins Mlp1p and Mlp2p are necessary components of the nuclear basket and that they also embed the NPC within a dynamic protein network, whose extended interactome includes the spindle organizer, silencing factors, the proteasome, and key components of messenger ribonucleoproteins (mRNPs). Ultrastructural observations indicate that the basket reduces chromatin crowding around the central transporter of the NPC and might function as a docking site for mRNP during nuclear export. In addition, we show that the Mlps contribute to NPC positioning, nuclear stability, and nuclear envelope morphology. Our results suggest that the Mlps are multifunctional proteins linking the nuclear transport channel to multiple macromolecular complexes involved in the regulation of gene expression and chromatin maintenance.

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