scholarly journals Neuronal network dysfunction in a model for Kleefstra syndrome mediated by enhanced NMDAR signaling

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Monica Frega ◽  
Katrin Linda ◽  
Jason M. Keller ◽  
Güvem Gümüş-Akay ◽  
Britt Mossink ◽  
...  
Keyword(s):  
Neuronal Network ◽  
Cortical Neurons ◽  
Neurodevelopmental Disorder ◽  
Control Networks ◽  
Human Neurons ◽  
Kleefstra Syndrome ◽  
Nmdar Subunit ◽  
Induced Pluripotent ◽  
Reduced Rate ◽  
The Impact

Abstract Kleefstra syndrome (KS) is a neurodevelopmental disorder caused by mutations in the histone methyltransferase EHMT1. To study the impact of decreased EHMT1 function in human cells, we generated excitatory cortical neurons from induced pluripotent stem (iPS) cells derived from KS patients. Neuronal networks of patient-derived cells exhibit network bursting with a reduced rate, longer duration, and increased temporal irregularity compared to control networks. We show that these changes are mediated by upregulation of NMDA receptor (NMDAR) subunit 1 correlating with reduced deposition of the repressive H3K9me2 mark, the catalytic product of EHMT1, at the GRIN1 promoter. In mice EHMT1 deficiency leads to similar neuronal network impairments with increased NMDAR function. Finally, we rescue the KS patient-derived neuronal network phenotypes by pharmacological inhibition of NMDARs. Summarized, we demonstrate a direct link between EHMT1 deficiency and NMDAR hyperfunction in human neurons, providing a potential basis for more targeted therapeutic approaches for KS.

scholarly journals Neuronal network dysfunction in a human model for Kleefstra syndrome mediated by enhanced NMDAR signaling

2019 ◽  
Author(s):  
Monica Frega ◽  
Katrin Linda ◽  
Jason M. Keller ◽  
Güvem Gümüş-Akay ◽  
Britt Mossink ◽  
...  
Keyword(s):  
Neural Network ◽  
Neuronal Network ◽  
Cortical Neurons ◽  
Critical Role ◽  
Ips Cells ◽  
Autism Spectrum ◽  
Human Model ◽  
Human Neurons ◽  
Kleefstra Syndrome ◽  
The Impact

AbstractEpigenetic regulation of gene transcription plays a critical role in neural network development and in the etiology of Intellectual Disability (ID) and Autism Spectrum Disorder (ASD). However, little is known about the mechanisms by which epigenetic dysregulation leads to neural network defects. Kleefstra syndrome (KS), caused by mutation in the histone methyltransferase EHMT1, is a neurodevelopmental disorder with the clinical features of both ID and ASD. To study the impact of decreased EHMT1 function in human cells, we generated excitatory cortical neurons from induced pluripotent stem (iPS) cells derived from KS patients. In addition, we created an isogenic set by genetically editing healthy iPS cells. Characterization of the neurons at the single-cell and neuronal network level revealed consistent discriminative properties that distinguished EHMT1-mutant from wildtype neurons. Mutant neuronal networks exhibited network bursting with a reduced rate, longer duration, and increased temporal irregularity compared to control networks. We show that these changes were mediated by the upregulation of the NMDA receptor (NMDAR) subunit 1 and correlate with reduced deposition of the repressive H3K9me2 mark, the catalytic product of EHMT1, at the GRIN1 promoter. Furthermore, we show that EHMT1 deficiency in mice leads to similar neuronal network impairments and increased NMDAR function. Finally, we could rescue the KS patient-derived neuronal network phenotypes by pharmacological inhibition of NMDARs. Together, our results demonstrate a direct link between EHMT1 deficiency in human neurons and NMDAR hyperfunction, providing the basis for a more targeted therapeutic approach to treating KS.

scholarly journals Increased Ca2+ signaling in NRXN1α+/− neurons derived from ASD induced pluripotent stem cells

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Sahar Avazzadeh ◽  
Katya McDonagh ◽  
Jamie Reilly ◽  
Yanqin Wang ◽  
Stephanie D. Boomkamp ◽  
...  
Keyword(s):  
Clinical Symptoms ◽  
Neurodevelopmental Disorder ◽  
Autism Spectrum ◽  
Healthy Donors ◽  
Human Neurons ◽  
Co Morbidity ◽  
Functional Consequences ◽  
Skin Biopsies ◽  
Screening Assays ◽  
Induced Pluripotent

Abstract Background Autism spectrum disorder (ASD) is a neurodevelopmental disorder with a high co-morbidity of epilepsy and associated with hundreds of rare risk factors. NRXN1 deletion is among the commonest rare genetic factors shared by ASD, schizophrenia, intellectual disability, epilepsy, and developmental delay. However, how NRXN1 deletions lead to different clinical symptoms is unknown. Patient-derived cells are essential to investigate the functional consequences of NRXN1 lesions to human neurons in different diseases. Methods Skin biopsies were donated by five healthy donors and three ASD patients carrying NRXN1α+/− deletions. Seven control and six NRXN1α+/− iPSC lines were derived and differentiated into day 100 cortical excitatory neurons using dual SMAD inhibition. Calcium (Ca2+) imaging was performed using Fluo4-AM, and the properties of Ca2+ transients were compared between two groups of neurons. Transcriptome analysis was carried out to undercover molecular pathways associated with NRXN1α+/− neurons. Results NRXN1α+/− neurons were found to display altered calcium dynamics, with significantly increased frequency, duration, and amplitude of Ca2+ transients. Whole genome RNA sequencing also revealed altered ion transport and transporter activity, with upregulated voltage-gated calcium channels as one of the most significant pathways in NRXN1α+/− neurons identified by STRING and GSEA analyses. Conclusions This is the first report to show that human NRXN1α+/− neurons derived from ASD patients’ iPSCs present novel phenotypes of upregulated VGCCs and increased Ca2+ transients, which may facilitate the development of drug screening assays for the treatment of ASD.

scholarly journals Two engineered AAV capsid variants for efficient transduction of human cortical neurons directly converted from iPSC

2021 ◽  
Author(s):  
Sandra Fischer ◽  
Jonas Weinmann ◽  
Frank Gillardon
Keyword(s):  
Cortical Neurons ◽  
Transduction Efficiency ◽  
Adeno Associated Virus ◽  
Viral Genomes ◽  
Glutamatergic Neurons ◽  
Human Neurons ◽  
Human Cell Cultures ◽  
Primary Astrocytes ◽  
Induced Pluripotent ◽  
Viral Titers

Recombinant adeno-associated virus (AAV) is the most widely used vector for gene therapy in clinical trials. To increase transduction efficiency and specificity, novel engineered AAV variants with modified capsid sequences are evaluated in human cell cultures and non-human primates. In the present study, we tested two novel AAV capsid variants, AAV2-NNPTPSR and AAV9-NVVRSSS, in human cortical neurons, which were directly converted from human induced pluripotent stem cells and cocultured with rat primary astrocytes. AAV2-NNPTPSR variant efficiently transduced both induced human cortical glutamatergic neurons and induced human cortical GABAergic interneurons. By contrast, AAV9-NVVRSSS variant transduced both induced human cortical neurons and cocultured rat primary astrocytes. High viral titers (1x10E5 viral genomes per cell) caused a significant decrease in viability of induced human cortical neurons. Low viral titers (1x10E4 viral genomes per cell) lead to a significant increase in the neuronal activity marker c-Fos in transduced human neurons following treatment with a potassium channel blocker, which may indicate functional alterations induced by viral transduction and/or transgene expression.

scholarly journals Using induced pluripotent stem cells to investigate human neuronal phenotypes in 1q21.1 deletion and duplication syndrome

2021 ◽  
Author(s):  
Gareth Chapman ◽  
Mouhamed Alsaqati ◽  
Sharna Lunn ◽  
Tanya Singh ◽  
Stefanie C Linden ◽  
...  
Keyword(s):  
Stem Cells ◽  
Induced Pluripotent Stem Cells ◽  
Pluripotent Stem Cells ◽  
Cortical Neurons ◽  
Neuronal Development ◽  
Motor Deficits ◽  
Differentiation Potential ◽  
Induced Pluripotent ◽  
The Impact ◽  
1Q21.1 Deletion

AbstractCopy Number Variation (CNV) at the 1q21.1 locus is associated with a range of neurodevelopmental and psychiatric disorders in humans, including abnormalities in head size and motor deficits. Yet, the functional consequences of these CNVs (both deletion and duplication) on neuronal development remain unknown. To determine the impact of CNV at the 1q21.1 locus on neuronal development, we generated induced pluripotent stem cells from individuals harbouring 1q21.1 deletion or duplication and differentiated them into functional cortical neurons. We show that neurons with 1q21.1 deletion or duplication display reciprocal phenotype with respect to proliferation, differentiation potential, neuronal maturation, synaptic density, and functional activity. Deletion of the 1q21.1 locus was also associated with an increased expression of lower cortical layer markers. This difference was conserved in the mouse model of 1q21.1 deletion, which displayed altered corticogenesis. Importantly, we show that neurons with 1q21.1 deletion and duplication are associated with differential expression of calcium channels and demonstrate that physiological deficits in neurons with 1q21.1 deletion or duplication can be pharmacologically modulated by targeting Ca2+ channel activity. These findings provide biological insight into the neuropathological mechanism underlying 1q21.1 associated brain disorder and indicate a potential target for therapeutic interventions.

scholarly journals Progranulin mutations result in impaired processing of prosaposin and reduced glucocerebrosidase activity

2019 ◽  
Vol 29 (5) ◽  
pp. 716-726 ◽  
Author(s):  
Clarissa Valdez ◽  
Daniel Ysselstein ◽  
Tiffany J Young ◽  
Jianbin Zheng ◽  
Dimitri Krainc
Keyword(s):  
Pluripotent Stem Cells ◽  
Cortical Neurons ◽  
Sphingolipid Metabolism ◽  
Gene Encoding ◽  
Temporal Lobes ◽  
Progressive Degeneration ◽  
Saposin C ◽  
Important Regulator ◽  
Induced Pluripotent ◽  
The Impact

Abstract Frontotemporal dementia (FTD) is a common neurogenerative disorder characterized by progressive degeneration in the frontal and temporal lobes. Heterozygous mutations in the gene encoding progranulin (PGRN) are a common genetic cause of FTD. Recently, PGRN has emerged as an important regulator of lysosomal function. Here, we examine the impact of PGRN mutations on the processing of full-length prosaposin to individual saposins, which are critical regulators of lysosomal sphingolipid metabolism. Using FTD-PGRN patient-derived cortical neurons differentiated from induced pluripotent stem cells, as well as post-mortem tissue from patients with FTLD-PGRN, we show that PGRN haploinsufficiency results in impaired processing of prosaposin to saposin C, a critical activator of the lysosomal enzyme glucocerebrosidase (GCase). Additionally, we found that PGRN mutant neurons had reduced lysosomal GCase activity, lipid accumulation and increased insoluble α-synuclein relative to isogenic controls. Importantly, reduced GCase activity in PGRN mutant neurons is rescued by treatment with saposin C. Together, these findings suggest that reduced GCase activity due to impaired processing of prosaposin may contribute to pathogenesis of FTD resulting from PGRN mutations.

scholarly journals ∆9-tetrahydrocannabinol negatively regulates neurite outgrowth and Akt signaling in hiPSC-derived cortical neurons

2018 ◽  
Author(s):  
Carole Shum ◽  
Lucia Dutan ◽  
Emily Annuario ◽  
Katherine Warre-Cornish ◽  
Samuel E. Taylor ◽  
...  
Keyword(s):  
Neurite Outgrowth ◽  
Cortical Neurons ◽  
Endocannabinoid System ◽  
Neuronal Morphology ◽  
Cannabinoid Type 1 Receptor ◽  
Cellular Processes ◽  
Extracellular Signal ◽  
Human Neurons ◽  
Induced Pluripotent ◽  
Arachidonoyl Glycerol

AbstractEndocannabinoids regulate different aspects of neurodevelopment. In utero exposure to the exogenous psychoactive cannabinoid Δ9-tetrahydrocannabinol (Δ9-THC), has been linked with abnormal cortical development in animal models. However, much less is known about the actions of endocannabinoids in human neurons. Here we investigated the effect of the endogenous endocannabinoid 2-arachidonoyl glycerol (2AG) and Δ9-THC on the development of neuronal morphology and activation of signaling kinases, in cortical glutamatergic neurons derived from human induced pluripotent stem cells (hiPSCs). Our data indicate that the cannabinoid type 1 receptor (CB1R), but not the cannabinoid 2 receptor (CB2R), GPR55 or TRPV1 receptors, is expressed in young, immature hiPSC-derived cortical neurons. Consistent with previous reports, 2AG and Δ9-THC negatively regulated neurite outgrowth. Interestingly, acute exposure to both 2AG and Δ9-THC inhibited phosphorylation of serine/threonine kinase extracellular signal-regulated protein kinases (ERK1/2), whereas Δ9-THC also reduced phosphorylation of Akt (aka PKB). Moreover, the CB1R inverse agonist SR 141716A attenuated the negative regulation of neurite outgrowth and ERK1/2 phosphorylation induced by 2AG and Δ9-THC. Taken together, our data suggest that hiPSC-derived cortical neurons express CB1Rs and are responsive to both endogenous and exogenous cannabinoids. Thus, hiPSC-neurons may represent a good cellular model for investigating the role of the endocannabinoid system in regulating cellular processes in human neurons.

scholarly journals Using induced pluripotent stem cells to investigate human neuronal phenotypes in 1q21.1 deletion and duplication syndrome

2021 ◽  
Author(s):  
Gareth Chapman ◽  
Mouhamed Alsaqati ◽  
Sharna Lunn ◽  
Tanya Singh ◽  
Stefanie C. Linden ◽  
...  
Keyword(s):  
Stem Cells ◽  
Induced Pluripotent Stem Cells ◽  
Pluripotent Stem Cells ◽  
Cortical Neurons ◽  
Neuronal Development ◽  
Motor Deficits ◽  
Differentiation Potential ◽  
Induced Pluripotent ◽  
The Impact ◽  
1Q21.1 Deletion

AbstractCopy Number Variation (CNV) at the 1q21.1 locus is associated with a range of neurodevelopmental and psychiatric disorders in humans, including abnormalities in head size and motor deficits. Yet, the functional consequences of these CNVs (both deletion and duplication) on neuronal development remain unknown. To determine the impact of CNV at the 1q21.1 locus on neuronal development, we generated induced pluripotent stem cells from individuals harbouring 1q21.1 deletion or duplication and differentiated them into functional cortical neurons. We show that neurons with 1q21.1 deletion or duplication display reciprocal phenotype with respect to proliferation, differentiation potential, neuronal maturation, synaptic density and functional activity. Deletion of the 1q21.1 locus was also associated with an increased expression of lower cortical layer markers. This difference was conserved in the mouse model of 1q21.1 deletion, which displayed altered corticogenesis. Importantly, we show that neurons with 1q21.1 deletion and duplication are associated with differential expression of calcium channels and demonstrate that physiological deficits in neurons with 1q21.1 deletion or duplication can be pharmacologically modulated by targeting Ca2+ channel activity. These findings provide biological insight into the neuropathological mechanism underlying 1q21.1 associated brain disorder and indicate a potential target for therapeutic interventions.

scholarly journals Deficiency in MT5-MMP Supports Branching of Human iPSCs-Derived Neurons and Reduces Expression of GLAST/S100 in iPSCs-Derived Astrocytes

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1705
Author(s):  
Nikita Arnst ◽  
Pedro Belio-Mairal ◽  
Laura García-González ◽  
Laurie Arnaud ◽  
Louise Greetham ◽  
...  
Keyword(s):  
Physiological Role ◽  
Neuronal Morphology ◽  
App Processing ◽  
Amyloidogenic Processing ◽  
Model Of Alzheimer’S Disease ◽  
Human Neurons ◽  
Human Ipscs ◽  
Induced Pluripotent ◽  
The Impact

For some time, it has been accepted that the β-site APP cleaving enzyme 1 (BACE1) and the γ-secretase are two main players in the amyloidogenic processing of the β-amyloid precursor protein (APP). Recently, the membrane-type 5 matrix metalloproteinase (MT5-MMP/MMP-24), mainly expressed in the nervous system, has been highlighted as a new key player in APP-processing, able to stimulate amyloidogenesis and also to generate a neurotoxic APP derivative. In addition, the loss of MT5-MMP has been demonstrated to abrogate pathological hallmarks in a mouse model of Alzheimer’s disease (AD), thus shedding light on MT5-MMP as an attractive new therapeutic target. However, a more comprehensive analysis of the role of MT5-MMP is necessary to evaluate how its targeting affects neurons and glia in pathological and physiological situations. In this study, leveraging on CRISPR-Cas9 genome editing strategy, we established cultures of human-induced pluripotent stem cells (hiPSC)-derived neurons and astrocytes to investigate the impact of MT5-MMP deficiency on their phenotypes. We found that MT5-MMP-deficient neurons exhibited an increased number of primary and secondary neurites, as compared to isogenic hiPSC-derived neurons. Moreover, MT5-MMP-deficient astrocytes displayed higher surface area and volume compared to control astrocytes. The MT5-MMP-deficient astrocytes also exhibited decreased GLAST and S100β expression. These findings provide novel insights into the physiological role of MT5-MMP in human neurons and astrocytes, suggesting that therapeutic strategies targeting MT5-MMP should be controlled for potential side effects on astrocytic physiology and neuronal morphology.

scholarly journals Loss-of-function variants in the schizophrenia risk gene SETD1A alter neuronal network activity in human neurons through cAMP/PKA pathway

2021 ◽  
Author(s):  
Shan Wang ◽  
Jon-Ruben van Rhijn ◽  
Ibrahim A Akkouh ◽  
Naoki Kogo ◽  
Nadine Maas ◽  
...  
Keyword(s):  
Neuronal Network ◽  
Synaptic Function ◽  
Network Activity ◽  
Loss Of Function ◽  
Functional Changes ◽  
Neuronal Network Activity ◽  
Camp Pathway ◽  
Human Neurons ◽  
Induced Pluripotent ◽  
Pka Pathway

Heterozygous loss-of-function (LoF) mutations in SETD1A, which encodes a subunit of histone H3 lysine 4 methyltransferase, have been shown to cause a novel neurodevelopmental syndrome and increase the risk for schizophrenia. To study the effect of decreased SETD1A function in human cells, we generated excitatory/inhibitory neuronal networks from human induced pluripotent stem cells with a SETD1A heterozygous LoF mutation (SETD1A+/-). Our data show that SETD1A haploinsufficiency resulted in altered neuronal network activity, which was mainly characterized by an overly synchronized network. In individual neurons, this network phenotype was reflected by increased somatodendritic complexity and elevated synaptic connectivity. We found that this network phenotype was driven by SETD1A haploinsufficiency in glutamatergic neurons. In accordance with the functional changes, transcriptomic profiling revealed perturbations in gene sets associated with schizophrenia, synaptic transmission and glutamatergic synaptic function. At the molecular level, we identified specific changes in the cAMP/PKA pathway pointing toward a hyperactive cAMP pathway in SETD1A+/- neurons. Finally, using pharmacological experiments targeting the cAMP pathway we were able to rescue the network deficits in SETD1A+/- cultures. In conclusion, our results illuminate key molecular, cellular and network abnormalities caused by SETD1A haploinsufficiency and demonstrate a direct link between SETD1A and the cAMP-dependent pathway in human neurons.

scholarly journals Functional expression of the ATP-gated P2X7 receptor in human iPSC-derived neurons and astrocytes

2021 ◽  
Author(s):  
Jaideep Kesavan ◽  
Orla Watters ◽  
Klaus Dinkel ◽  
Michael Hamacher ◽  
Jochen H.M. Prehn ◽  
...  
Keyword(s):  
Pluripotent Stem Cells ◽  
Cortical Neurons ◽  
P2x7 Receptor ◽  
Functional Expression ◽  
Extracellular Adenosine ◽  
Functional Studies ◽  
Human Neurons ◽  
Induced Pluripotent ◽  
Human Ipsc

AbstractThe P2X7 receptor (P2X7R) is a cation membrane channel activated by extracellular adenosine 5′-triphosphate. Activation of this receptor results in numerous downstream events including the modulation of neurotransmission, release of pro-inflammatory mediators, cell proliferation or cell death. While the expression of P2X7Rs is well documented on microglia and oligodendrocytes, the presence of functional P2X7Rs on neurons and astrocytes remains debated. Furthermore, to date, functional studies on the P2X7R are mostly limited to studies in cells from rodents and immortalised cell lines expressing human P2X7Rs. To assess the functional expression of P2X7Rs in human neurons and astrocytes, we differentiated human-induced pluripotent stem cells (hiPSCs) into forebrain cortical neurons that co-express FOXG1 and βIII-tubulin as well as S100 β-expressing astrocytes. Immunostaining revealed prominent punctate P2X7R staining on the soma and processes of hiPSC-derived neurons and astrocytes. In addition, our data show that stimulation with the potent nonselective P2X7R agonist BzATP induces robust calcium rises in hiPSC-derived neurons and astrocytes, which were blocked by the selective P2X7R antagonist AFC-5128. Together, our findings provide evidence for the functional expression of P2X7Rs in hiPSC-derived forebrain cortical neurons and astrocytes demonstrating that these cells offer the potential for investigating P2X7R-mediated pathophysiology and drug screening in vitro.

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