scholarly journals Dysfunction in nonsense-mediated decay, protein homeostasis, mitochondrial function, and brain connectivity in ALS-FUS mice with cognitive deficits

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Wan Yun Ho ◽  
Ira Agrawal ◽  
Sheue-Houy Tyan ◽  
Emma Sanford ◽  
Wei-Tang Chang ◽  
...  
Keyword(s):  
Cognitive Deficits ◽  
Brain Connectivity ◽  
Expression Patterns ◽  
Long Term Potentiation ◽  
Protein Homeostasis ◽  
Spine Density ◽  
Nonsense Mediated Decay ◽  
Endogenous Expression ◽  
Mitochondrial Functions

AbstractAmyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) represent two ends of the same disease spectrum of adult-onset neurodegenerative diseases that affect the motor and cognitive functions, respectively. Multiple common genetic loci such as fused in sarcoma (FUS) have been identified to play a role in ALS and FTD etiology. Current studies indicate that FUS mutations incur gain-of-toxic functions to drive ALS pathogenesis. However, how the disease-linked mutations of FUS affect cognition remains elusive. Using a mouse model expressing an ALS-linked human FUS mutation (R514G-FUS) that mimics endogenous expression patterns, we found that FUS proteins showed an age-dependent accumulation of FUS proteins despite the downregulation of mouse FUS mRNA by the R514G-FUS protein during aging. Furthermore, these mice developed cognitive deficits accompanied by a reduction in spine density and long-term potentiation (LTP) within the hippocampus. At the physiological expression level, mutant FUS is distributed in the nucleus and cytosol without apparent FUS aggregates or nuclear envelope defects. Unbiased transcriptomic analysis revealed a deregulation of genes that cluster in pathways involved in nonsense-mediated decay, protein homeostasis, and mitochondrial functions. Furthermore, the use of in vivo functional imaging demonstrated widespread reduction in cortical volumes but enhanced functional connectivity between hippocampus, basal ganglia and neocortex in R514G-FUS mice. Hence, our findings suggest that disease-linked mutation in FUS may lead to changes in proteostasis and mitochondrial dysfunction that in turn affect brain structure and connectivity resulting in cognitive deficits.

scholarly journals FUS-mediated dysregulation of Sema5a, an autism-related gene, in FUS mice with hippocampus-dependent cognitive deficits

2019 ◽  
Vol 28 (22) ◽  
pp. 3777-3791 ◽  
Author(s):  
Wan Yun Ho ◽  
Jer-Cherng Chang ◽  
Sheue-Houy Tyan ◽  
Yi-Chun Yen ◽  
Kenneth Lim ◽  
...  
Keyword(s):  
Cognitive Deficits ◽  
Long Term Potentiation ◽  
Autism Spectrum ◽  
Dependent Manner ◽  
Spine Density ◽  
Preferential Expression ◽  
Fused In Sarcoma ◽  
Endogenous Expression ◽  
Term Potentiation ◽  
The Central Nervous System

Abstract Pathological fused in sarcoma (FUS) inclusions are found in 10% of patients with frontotemporal dementia and those with amyotrophic lateral sclerosis (ALS) carrying FUS mutations. Current work indicates that FUS mutations may incur gain-of-toxic functions to drive ALS pathogenesis. However, how FUS dysfunction may affect cognition remains elusive. Using a mouse model expressing wild-type human FUS mimicking the endogenous expression pattern and level within the central nervous system, we found that they developed hippocampus-mediated cognitive deficits accompanied by an age-dependent reduction in spine density and long-term potentiation in their hippocampus. However, there were no apparent FUS aggregates, nuclear envelope defects and cytosolic FUS accumulation. These suggest that these proposed pathogenic mechanisms may not be the underlying causes for the observed cognitive deficits. Unbiased transcriptomic analysis identified expression changes in a small set of genes with preferential expression in the neurons and oligodendrocyte lineage cells. Of these, we focused on Sema5a, a gene involved in axon guidance, spine dynamics, Parkinson’s disease and autism spectrum disorders. Critically, FUS binds directly to Sema5a mRNA and regulates Sema5a expression in a FUS-dose-dependent manner. Taken together, our data suggest that FUS-driven Sema5a deregulation may underlie the cognitive deficits in FUS transgenic mice.

scholarly journals Spatiotemporal expression and transcriptional perturbations by long noncoding RNAs in the mouse brain

2015 ◽  
Vol 112 (22) ◽  
pp. 6855-6862 ◽  
Author(s):  
Loyal A. Goff ◽  
Abigail F. Groff ◽  
Martin Sauvageau ◽  
Zachary Trayes-Gibson ◽  
Diana B. Sanchez-Gomez ◽  
...  
Keyword(s):  
Neural Development ◽  
Expression Patterns ◽  
Noncoding Rnas ◽  
Brain Regions ◽  
Long Noncoding Rnas ◽  
Adult Brain ◽  
Mammalian Brain ◽  
Endogenous Expression ◽  
Spatiotemporal Expression

Long noncoding RNAs (lncRNAs) have been implicated in numerous cellular processes including brain development. However, the in vivo expression dynamics and molecular pathways regulated by these loci are not well understood. Here, we leveraged a cohort of 13 lncRNA-null mutant mouse models to investigate the spatiotemporal expression of lncRNAs in the developing and adult brain and the transcriptome alterations resulting from the loss of these lncRNA loci. We show that several lncRNAs are differentially expressed both in time and space, with some presenting highly restricted expression in only selected brain regions. We further demonstrate altered regulation of genes for a large variety of cellular pathways and processes upon deletion of the lncRNA loci. Finally, we found that 4 of the 13 lncRNAs significantly affect the expression of several neighboring protein-coding genes in a cis-like manner. By providing insight into the endogenous expression patterns and the transcriptional perturbations caused by deletion of the lncRNA locus in the developing and postnatal mammalian brain, these data provide a resource to facilitate future examination of the specific functional relevance of these genes in neural development, brain function, and disease.

scholarly journals Microglia inhibition rescues developmental hypofrontality in a mouse model of mental illness

2018 ◽  
Author(s):  
Mattia Chini ◽  
Christoph Lindemann ◽  
Jastyn A. Pöpplau ◽  
Xiaxia Xu ◽  
Joachim Ahlbeck ◽  
...  
Keyword(s):  
Mental Illness ◽  
Cognitive Deficits ◽  
Pyramidal Neurons ◽  
List Type ◽  
Spine Density ◽  
Abnormal Rate ◽  
Hippocampal Networks ◽  
Local Circuits ◽  
Circuit Function

SUMMARYCognitive deficits, core features of mental illness, largely result from dysfunction of prefrontal-hippocampal networks. This dysfunction emerges already during early development, before a detectable behavioral readout, yet the cellular elements controlling the abnormal maturation are still unknown. Combining in vivo electrophysiology and optogenetics with neuroanatomy and pharmacology in neonatal mice mimicking the dual genetic - environmental etiology of psychiatric disorders, we identified pyramidal neurons in layer II/III of the prefrontal cortex as key elements causing disorganized oscillatory entrainment of local circuits in beta-gamma frequencies. Their abnormal firing rate and timing result from sparser dendritic arborization and lower spine density. Pharmacological modulation of aberrantly hyper-mature microglia rescues morphological, synaptic and functional neuronal deficits and restores the early circuit function. Elucidation of the cellular substrate of developmental miswiring related to later cognitive deficits opens new perspectives for identification of neurobiological targets, amenable to therapies.HighlightsMice mimicking the etiology of mental illness have dysregulated prefrontal networkStructural and synaptic deficits cause abnormal rate and timing of pyramidal firingWeaker activation of prefrontal circuits results from deficits of pyramidal neuronsRescue of microglial function restores developing prefrontal circuits

scholarly journals Knock-in tagging in zebrafish facilitated by insertion into non-coding regions

2021 ◽  
Author(s):  
Daniel S Levic ◽  
Naoya Yamaguchi ◽  
Siyao Wang ◽  
Holger Knaut ◽  
Michel Bagnat
Keyword(s):  
Protein Function ◽  
Cell Biology ◽  
Quantitative Imaging ◽  
Expression Patterns ◽  
Imaging Studies ◽  
Coding Regions ◽  
Fluorescent Markers ◽  
Endogenous Expression ◽  
Epithelial Biology

Zebrafish provide an excellent model for in vivo cell biology studies due to their amenability to live imaging. Protein visualization in zebrafish has traditionally relied on overexpression of fluorescently tagged proteins from heterologous promoters, making it difficult to recapitulate endogenous expression patterns and protein function. One way to circumvent this problem is to tag the proteins by modifying their endogenous genomic loci. Such an approach is not widely available to zebrafish researchers due to inefficient homologous recombination and the error-prone nature of targeted integration in zebrafish. Here, we report a simple approach for tagging proteins in zebrafish on their N- or C termini with fluorescent markers by inserting PCR-generated donor amplicons into non-coding regions of the corresponding genes. Using this approach, we generated endogenously tagged alleles for several genes critical for epithelial biology and organ development including the tight junction components ZO-1 and Cldn15la, the trafficking effector Rab11a, and the ECM receptor β1 integrin. Our approach facilitates the generation of knock-in lines in zebrafish, opening the way for accurate quantitative imaging studies.

scholarly journals Spaciotemporal Association and Bone Morphogenetic Protein Regulation of Sclerostin and Osterix Expression during Embryonic Osteogenesis

Endocrinology ◽  
2004 ◽  
Vol 145 (10) ◽  
pp. 4685-4692 ◽  
Author(s):  
Yoshio Ohyama ◽  
Akira Nifuji ◽  
Yukiko Maeda ◽  
Teruo Amagasa ◽  
Masaki Noda
Keyword(s):  
Bone Morphogenetic Protein ◽  
Bone Growth ◽  
Expression Patterns ◽  
Cranial Bone ◽  
Nodule Formation ◽  
Endogenous Expression ◽  
Sost Gene ◽  
Morphogenetic Protein

Abstract Sclerostin (SOST), a member of the cystine-knot superfamily, is essential for proper skeletogenesis because a loss-of-function mutation in the SOST gene results in sclerosteosis featured with massive bone growth in humans. To understand the function of SOST in developmental skeletal tissue formation, we examined SOST gene expression in embryonic osteogenesis in vitro and in vivo. During osteoblastic differentiation in primary calvarial cells, the levels of SOST expression were increased along with those of alkaline phosphatase activity and nodule formation. In situ hybridization study revealed that SOST mRNA expression was observed in the digits in embryonic 13-d limb buds, and SOST expression was observed in osteogenic front in embryonic 16.5-d postcoitus embryonic calvariae, and this expression persisted in the peripheral area of cranial bone in the later developmental stage (embryonic 18.5-d post coitum). These temporal and spacial expression patterns in vivo and in vitro were in parallel to those of osterix (Osx), which is a critical transcriptional factor for bone formation. Similar coexpression of SOST and Osx mRNA was observed when the primary osteoblastic calvarial cells were cultured in the presence of bone morphogenetic protein (BMP)2 in vitro. Moreover, endogenous expression of SOST and Osx mRNA was inhibited by infection of noggin-expression adenovirus into the primary osteoblastic calvarial cells, suggesting that endogenous BMPs are required for these cells to express SOST and Osx mRNA. Thus, expression and regulation of SOST under the control of BMP were closely associated with those of Osx in vivo and in vitro.

scholarly journals Ultrastructural Evidence for a Role of Astrocytes and Glycogen-Derived Lactate in Learning-Dependent Synaptic Stabilization

2019 ◽  
Vol 30 (4) ◽  
pp. 2114-2127 ◽  
Author(s):  
E Vezzoli ◽  
C Calì ◽  
M De Roo ◽  
L Ponzoni ◽  
E Sogne ◽  
...  
Keyword(s):  
Structural Changes ◽  
Glycogen Metabolism ◽  
Selective Inhibition ◽  
Long Term Potentiation ◽  
Learning Task ◽  
Long Term Memory ◽  
Spine Density ◽  
Synaptic Changes

Abstract Long-term memory formation (LTM) is a process accompanied by energy-demanding structural changes at synapses and increased spine density. Concomitant increases in both spine volume and postsynaptic density (PSD) surface area have been suggested but never quantified in vivo by clear-cut experimental evidence. Using novel object recognition in mice as a learning task followed by 3D electron microscopy analysis, we demonstrate that LTM induced all aforementioned synaptic changes, together with an increase in the size of astrocytic glycogen granules, which are a source of lactate for neurons. The selective inhibition of glycogen metabolism in astrocytes impaired learning, affecting all the related synaptic changes. Intrahippocampal administration of l-lactate rescued the behavioral phenotype, along with spine density within 24 hours. Spine dynamics in hippocampal organotypic slices undergoing theta burst-induced long-term potentiation was similarly affected by inhibition of glycogen metabolism and rescued by l-lactate. These results suggest that learning primes astrocytic energy stores and signaling to sustain synaptic plasticity via l-lactate.

scholarly journals Impairments of Synaptic Plasticity Induction Threshold and Network Oscillatory Activity in the Hippocampus Underlie Memory Deficits in a Non-Transgenic Mouse Model of Amyloidosis

Biology ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 175
Author(s):  
Jennifer Mayordomo-Cava ◽  
Guillermo Iborra-Lázaro ◽  
Souhail Djebari ◽  
Sara Temprano-Carazo ◽  
Irene Sánchez-Rodríguez ◽  
...  
Keyword(s):  
Cognitive Deficits ◽  
Amyloid Β ◽  
Memory Deficits ◽  
Long Term Potentiation ◽  
Biologically Active ◽  
Network Activity ◽  
Oscillatory Activity ◽  
In Vivo Model

In early Alzheimer disease (AD) models synaptic failures and upstreaming aberrant patterns of network synchronous activity result in hippocampal-dependent memory deficits. In such initial stage, soluble forms of Amyloid-β (Aβ) peptides have been shown to play a causal role. Among different Aβ species, Aβ25–35 has been identified as the biologically active fragment, as induces major neuropathological signs related to early AD stages. Consequently, it has been extensively used to acutely explore the pathophysiological events related with neuronal dysfunction induced by soluble Aβ forms. However, the synaptic mechanisms underlying its toxic effects on hippocampal-dependent memory remain unresolved. Here, in an in vivo model of amyloidosis generated by intracerebroventricular injections of Aβ25–35 we studied the synaptic dysfunction mechanisms underlying hippocampal cognitive deficits. At the synaptic level, long-term potentiation (LTP) of synaptic excitation and inhibition was induced in CA1 region by high frequency simulation (HFS) applied to Schaffer collaterals. Aβ25–35 was found to alter metaplastic mechanisms of plasticity, facilitating long-term depression (LTD) of both types of LTP. In addition, aberrant synchronization of hippocampal network activity was found while at the behavioral level, deficits in hippocampal-dependent habituation and recognition memories emerged. Together, our results provide a substrate for synaptic disruption mechanism underlying hippocampal cognitive deficits present in Aβ25–35 amyloidosis model.

scholarly journals Missense mutation of Fmr1 results in impaired AMPAR-mediated plasticity and socio-cognitive deficits in mice

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Marta Prieto ◽  
Alessandra Folci ◽  
Gwénola Poupon ◽  
Sara Schiavi ◽  
Valeria Buzzelli ◽  
...  
Keyword(s):  
Mouse Model ◽  
Cognitive Deficits ◽  
Fragile X ◽  
Long Term Potentiation ◽  
Surface Expression ◽  
Missense Mutations ◽  
Spine Density ◽  
Cgg Repeat ◽  
Electrophysiological Recordings ◽  
Receptor Surface Expression

AbstractFragile X syndrome (FXS) is the most frequent form of inherited intellectual disability and the best-described monogenic cause of autism. CGG-repeat expansion in the FMR1 gene leads to FMR1 silencing, loss-of-expression of the Fragile X Mental Retardation Protein (FMRP), and is a common cause of FXS. Missense mutations in the FMR1 gene were also identified in FXS patients, including the recurrent FMRP-R138Q mutation. To investigate the mechanisms underlying FXS caused by this mutation, we generated a knock-in mouse model (Fmr1R138Q) expressing the FMRP-R138Q protein. We demonstrate that, in the hippocampus of the Fmr1R138Q mice, neurons show an increased spine density associated with synaptic ultrastructural defects and increased AMPA receptor-surface expression. Combining biochemical assays, high-resolution imaging, electrophysiological recordings, and behavioural testing, we also show that the R138Q mutation results in impaired hippocampal long-term potentiation and socio-cognitive deficits in mice. These findings reveal the functional impact of the FMRP-R138Q mutation in a mouse model of FXS.

scholarly journals Knock-in tagging in zebrafish facilitated by insertion into non-coding regions

Development ◽  
2021 ◽  
Author(s):  
Daniel S. Levic ◽  
Naoya Yamaguchi ◽  
Siyao Wang ◽  
Holger Knaut ◽  
Michel Bagnat
Keyword(s):  
Protein Function ◽  
Cell Biology ◽  
Fluorescent Proteins ◽  
Quantitative Imaging ◽  
Expression Patterns ◽  
Imaging Studies ◽  
Coding Regions ◽  
Endogenous Expression ◽  
Epithelial Biology

Zebrafish provide an excellent model for in vivo cell biology studies due to their amenability to live imaging. Protein visualization in zebrafish has traditionally relied on overexpression of fluorescently tagged proteins from heterologous promoters, making it difficult to recapitulate endogenous expression patterns and protein function. One way to circumvent this problem is to tag the proteins by modifying their endogenous genomic loci. Such an approach is not widely available to zebrafish researchers due to inefficient homologous recombination and the error-prone nature of targeted integration in zebrafish. Here, we report a simple approach for tagging proteins in zebrafish on their N- or C termini with fluorescent proteins by inserting PCR-generated donor amplicons into non-coding regions of the corresponding genes. Using this approach, we generated endogenously tagged alleles for several genes critical for epithelial biology and organ development including the tight junction components ZO-1 and Cldn15la, the trafficking effector Rab11a, the apical polarity protein aPKC, and the ECM receptor Integrin β1b. Our approach facilitates the generation of knock-in lines in zebrafish, opening the way for accurate quantitative imaging studies.

The metalloproteinase ADAM10 is required for retinal ganglion cell axon guidance in the developing visual systems

2007 ◽  
Vol 30 (4) ◽  
pp. 77
Author(s):  
Y. Y. Chen ◽  
C. L. Hehr ◽  
K. Atkinson-Leadbeater ◽  
J. C. Hocking ◽  
S. McFarlane
Keyword(s):  
Ganglion Cell ◽  
Axon Guidance ◽  
Retinal Ganglion Cell ◽  
Growth Cone ◽  
Expression Patterns ◽  
Optic Tract ◽  
Axon Growth ◽  
Proteolytic Processing ◽  
Retinal Ganglion

Background: The growth cone interprets cues in its environment in order to reach its target. We want to identify molecules that regulate growth cone behaviour in the developing embryo. We investigated the role of A disintegrin and metalloproteinase 10 (ADAM10) in axon guidance in the developing visual system of African frog, Xenopus laevis. Methods: We first examined the expression patterns of adam10 mRNA by in situ hybridization. We then exposed the developing optic tract to an ADAM10 inhibitor, GI254023X, in vivo. Lastly, we inhibited ADAM10 function in diencephalic neuroepithelial cells (through which retinal ganglion cell (RGC) axons extend) or RGCs by electroporating or transfecting an ADAM10 dominant negative (dn-adam10). Results: We show that adam10 mRNA is expressed in the dorsal neuroepithelium over the time RGC axons extend towards their target, the optic tectum. Second, pharmacological inhibition of ADAM10 in an in vivo exposed brain preparation causes the failure of RGC axons to recognize their target at low concentrations (0.5, 1 μM), and the failure of the axons to make a caudal turn in the mid-diencephalon at higher concentration (5 μM). Thus, ADAM10 function is required for RGC axon guidance at two key guidance decisions. Finally, molecular inhibition of ADAM10 function by electroporating dn-adam10 in the brain neuroepithelium causes defects in RGC axon target recognition (57%) and/or defects in caudal turn (12%), as seen with the pharmacological inhibitor. In contrast, molecular inhibition of ADAM10 within the RGC axons has no effect. Conclusions: These data argue strongly that ADAM10 acts cell non-autonomously within the neuroepithelium to regulate the guidance of RGC axons. This study shows for the first time that a metalloproteinase acts in a cell non-autonomous fashion to direct vertebrate axon growth. It will provide important insights into candidate molecules that could be used to reform nerve connections if destroyed because of injury or disease. References Hattori M, Osterfield M, Flanagan JG. Regulated cleavage of a contact-mediated axon repellent. Science 2000; 289(5483):1360-5. Janes PW, Saha N, Barton WA, Kolev MV, Wimmer-Kleikamp SH, Nievergall E, Blobel CP, Himanen JP, Lackmann M, Nikolov DB. Adam meets Eph: an ADAM substrate recognition module acts as a molecular switch for ephrin cleavage in trans. Cell 2005; 123(2):291-304. Pan D, Rubin GM. Kuzbanian controls proteolytic processing of Notch and mediates lateral inhibition during Drosophila and vertebrate neurogenesis. Cell 1997; 90(2):271-80.

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