scholarly journals WGCNA Identifies Translational and Proteasome-Ubiquitin Dysfunction in Rett Syndrome

2021 ◽  
Vol 22 (18) ◽  
pp. 9954
Author(s):  
Florencia Haase ◽  
Brian S. Gloss ◽  
Patrick P. L. Tam ◽  
Wendy A. Gold
Keyword(s):  
Rett Syndrome ◽  
Neurodevelopmental Disorder ◽  
Core Gene ◽  
Cellular Level ◽  
Neural Cells ◽  
Pathogenic Mutations ◽  
Gene Correlation ◽  
Healthy Control ◽  
Ubiquitination Pathway ◽  
Induced Pluripotent

Rett Syndrome (RTT) is an X linked neurodevelopmental disorder caused by mutations in the methyl-CpG-binding protein 2 (MECP2) gene, resulting in severe cognitive and physical disabilities. Despite an apparent normal prenatal and postnatal development period, symptoms usually present around 6 to 18 months of age. Little is known about the consequences of MeCP2 deficiency at a molecular and cellular level before the onset of symptoms in neural cells, and subtle changes at this highly sensitive developmental stage may begin earlier than symptomatic manifestation. Recent transcriptomic studies of patient induced pluripotent stem cells (iPSC)-differentiated neurons and brain organoids harbouring pathogenic mutations in MECP2, have unravelled new insights into the cellular and molecular changes caused by these mutations. Here we interrogated transcriptomic modifications in RTT patients using publicly available RNA-sequencing datasets of patient iPSCs harbouring pathogenic mutations and healthy control iPSCs by Weighted Gene Correlation Network Analysis (WGCNA). Preservation analysis identified core gene pathways involved in translation, ribosomal function, and ubiquitination perturbed in some MECP2 mutant iPSC lines. Furthermore, differential gene expression of the parental fibroblasts and iPSC-derived neurons revealed alterations in genes in the ubiquitination pathway and neurotransmission in fibroblasts and differentiated neurons respectively. These findings might suggest that global translational dysregulation and proteasome ubiquitin function in Rett syndrome begins in progenitor cells prior to lineage commitment and differentiation into neural cells.

scholarly journals Genetic and epigenetic determinants of reactivation of Mecp2 and the inactive X chromosome in neural stem cells

2021 ◽  
Author(s):  
Hegias Mira-Bontenbal ◽  
Beatrice Tan ◽  
Cristina Gontan ◽  
Sander Goossens ◽  
R.G. Boers ◽  
...  
Keyword(s):  
Stem Cells ◽  
Neural Stem Cells ◽  
Rett Syndrome ◽  
X Chromosome ◽  
Neurodevelopmental Disorder ◽  
Ctcf Binding ◽  
Neural Cells ◽  
Reporter System ◽  
Inactive X Chromosome ◽  
Phenotypic Reversal

AbstractRett Syndrome is a neurodevelopmental disorder in girls that is caused by heterozygous inactivation of the chromatin remodeler gene MECP2. Rett Syndrome may therefore be treated by reactivation of the wild type copy of MECP2 from the inactive X chromosome. Most studies that model Mecp2 reactivation have used mouse fibroblasts rather than neural cells, which would be critical for phenotypic reversal, and rely on fluorescent reporters that lack adequate sensitivity. Here, we present a mouse model system for monitoring Mecp2 reactivation that is more sensitive and versatile than any bioluminescent and fluorescent system currently available. The model consists of neural stem cells derived from female mice with a dual reporter system where MECP2 is fused to NanoLuciferase and TdTomato on the inactive X chromosome. We show by bioluminescence and fluorescence that Mecp2 is synergistically reactivated by 5-Aza treatment and Xist knockdown. As expected, other genes on the inactive X chromosome are also reactivated, the majority of which overlaps with genes reactivated early during reprogramming of mouse embryonic fibroblasts to iPSCs. Genetic and epigenetic features such as CpG density, SINE elements, distance to escapees and CTCF binding are consistent indicators of reactivation, whereas different higher order chromatin areas are either particularly prone or resistant to reactivation. Our MeCP2 reactivation monitoring system thereby suggests that genetic and epigenetic features on the inactive X chromosome affect reactivation of its genes, irrespective of cell type or procedure of reactivation.

scholarly journals Modeling Rett Syndrome With Human Patient-Specific Forebrain Organoids

2020 ◽  
Vol 8 ◽  
Author(s):  
Ana Rita Gomes ◽  
Tiago G. Fernandes ◽  
Sandra H. Vaz ◽  
Teresa P. Silva ◽  
Evguenia P. Bekman ◽  
...  
Keyword(s):  
Rett Syndrome ◽  
Neural Development ◽  
Neurological Disorders ◽  
Neurodevelopmental Disorder ◽  
Cortical Layer ◽  
Patient Specific ◽  
Human Patient ◽  
Personalized Diagnosis ◽  
Induced Pluripotent ◽  
Lower Expression

Engineering brain organoids from human induced pluripotent stem cells (hiPSCs) is a powerful tool for modeling brain development and neurological disorders. Rett syndrome (RTT), a rare neurodevelopmental disorder, can greatly benefit from this technology, since it affects multiple neuronal subtypes in forebrain sub-regions. We have established dorsal and ventral forebrain organoids from control and RTT patient-specific hiPSCs recapitulating 3D organization and functional network complexity. Our data revealed a premature development of the deep-cortical layer, associated to the formation of TBR1 and CTIP2 neurons, and a lower expression of neural progenitor/proliferative cells in female RTT dorsal organoids. Moreover, calcium imaging and electrophysiology analysis demonstrated functional defects of RTT neurons. Additionally, assembly of RTT dorsal and ventral organoids revealed impairments of interneuron’s migration. Overall, our models provide a better understanding of RTT during early stages of neural development, demonstrating a great potential for personalized diagnosis and drug screening.

scholarly journals Endosomal Dysfunction in iPSC-Derived Neural Cells from Parkinson’s Disease Patients with VPS35 D620N

2020 ◽  
Author(s):  
Keiko Bono ◽  
Chikako Miyauchi-Hara ◽  
Shunsuke Sumi ◽  
Hisayoshi Oka ◽  
Yasuyuki Iguchi ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Apoptotic Cell ◽  
Induced Pluripotent Stem Cell ◽  
Control Group ◽  
Neural Cells ◽  
Endosomal Trafficking ◽  
Healthy Control ◽  
Induced Pluripotent ◽  
Vacuolar Protein

Abstract Mutations in the Vacuolar protein sorting 35 ( VPS35 ) gene have been linked to familial Parkinson’s disease (PD), PARK17. VPS35 is a key component of the retromer complex, which plays a central role in endosomal trafficking. However, whether and how VPS35 deficiency or mutation contributes to PD pathogenesis remain unclear. Here, we analyzed human induced pluripotent stem cell (iPSC)-derived neurons from PD patients with theVPS35D620N mutation and addressed relevant disease mechanisms. In the disease group, dopaminergic (DA) neurons underwent extensive apoptotic cell death. Furthermore, the movement of Rab5a - or Rab7a - positive endosomes was slower , and the endosome fission and fusion frequencies were lower in the PD group than in the healthy control group . Interestingly , vesicles positive for cation-independent mannose 6-phosphate receptor transported by retromers were abnormally localized in glia-like cells derived from patient iPSCs. These results suggest that VPS35 mutation causes endosomal dysfunction in neural cells in PARK17.

scholarly journals Pre-clinical Investigation of Rett Syndrome Using Human Stem Cell-Based Disease Models

2021 ◽  
Vol 15 ◽  
Author(s):  
Florencia D. Haase ◽  
Bronte Coorey ◽  
Lisa Riley ◽  
Laurence C. Cantrill ◽  
Patrick P. L. Tam ◽  
...  
Keyword(s):  
Rett Syndrome ◽  
Neural Development ◽  
Clinical Investigation ◽  
Neurodevelopmental Disorder ◽  
Limited Resource ◽  
Cell Types ◽  
Disease Models ◽  
Conventional Animal ◽  
Brain Organoid ◽  
Induced Pluripotent

Rett syndrome (RTT) is an X-linked neurodevelopmental disorder, mostly caused by mutations in MECP2. The disorder mainly affects girls and it is associated with severe cognitive and physical disabilities. Modeling RTT in neural and glial cell cultures and brain organoids derived from patient- or mutation-specific human induced pluripotent stem cells (iPSCs) has advanced our understanding of the pathogenesis of RTT, such as disease-causing mechanisms, disease progression, and cellular and molecular pathology enabling the identification of actionable therapeutic targets. Brain organoid models that recapitulate much of the tissue architecture and the complexity of cell types in the developing brain, offer further unprecedented opportunity for elucidating human neural development, without resorting to conventional animal models and the limited resource of human neural tissues. This review focuses on the new knowledge of RTT that has been gleaned from the iPSC-based models as well as limitations of the models and strategies to refine organoid technology in the quest for clinically relevant disease models for RTT and the broader spectrum of neurodevelopmental disorders.

scholarly journals Exosomes regulate Neurogenesis and Circuit Assembly in a Model of Rett Syndrome

2017 ◽  
Author(s):  
Pranav Sharma ◽  
Pinar Mesci ◽  
Cassiano Carromeu ◽  
Daniel McClatchy ◽  
Lucio Schiapparelli ◽  
...  
Keyword(s):  
Rett Syndrome ◽  
Neural Development ◽  
Neuronal Development ◽  
Neurodevelopmental Disorder ◽  
The Body ◽  
Neural Cultures ◽  
Induced Pluripotent ◽  
And Function ◽  
Signaling Components ◽  
Promising Avenue

SummaryExosomes are thought to be secreted by all cells in the body and to be involved in intercellular communication. Here, we tested whether neural exosomes regulate the development of neural circuits and whether exosome-mediated signaling may be aberrant in the neurodevelopmental disorder Rett Syndrome (RTT). Quantitative proteomic analysis comparing exosomes from human induced pluripotent stem cells (hiPSC) - derived RTT patient or control neural cultures indicates that control exosomes contain signaling components capable of influencing neuronal development and function, which are lacking in RTT exosomes. Moreover, treatment with control exosomes rescues neuron number, apoptosis, synaptic puncta and synchronized firing phenotypes of MeCP2 knockdown in human primary neurons, indicating that exosomes have the capacity to influence neural development and may be a promising avenue to treat neurodevelopmental disorders like Rett Syndrome.HighlightsExosome proteomics distinguish cargo in RTT vs control hiPSC-derived neural cultures Control but not RTT exosomes increase neurogenesis in human neural cultures hiPSC-derived neural exosomes reverse pathological phenotypes in RTT neural cultures RTT exosomes do not impair neural development

scholarly journals Emerging hiPSC Models for Drug Discovery in Neurodegenerative Diseases

2021 ◽  
Vol 22 (15) ◽  
pp. 8196
Author(s):  
Dorit Trudler ◽  
Swagata Ghatak ◽  
Stuart A. Lipton
Keyword(s):  
Drug Discovery ◽  
Animal Models ◽  
Neurodegenerative Diseases ◽  
Disease Modeling ◽  
Induced Pluripotent Stem Cell ◽  
Neural Function ◽  
Neural Cells ◽  
Human Samples ◽  
Healthy Donors ◽  
Induced Pluripotent

Neurodegenerative diseases affect millions of people worldwide and are characterized by the chronic and progressive deterioration of neural function. Neurodegenerative diseases, such as Alzheimer’s disease (AD), Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS), and Huntington’s disease (HD), represent a huge social and economic burden due to increasing prevalence in our aging society, severity of symptoms, and lack of effective disease-modifying therapies. This lack of effective treatments is partly due to a lack of reliable models. Modeling neurodegenerative diseases is difficult because of poor access to human samples (restricted in general to postmortem tissue) and limited knowledge of disease mechanisms in a human context. Animal models play an instrumental role in understanding these diseases but fail to comprehensively represent the full extent of disease due to critical differences between humans and other mammals. The advent of human-induced pluripotent stem cell (hiPSC) technology presents an advantageous system that complements animal models of neurodegenerative diseases. Coupled with advances in gene-editing technologies, hiPSC-derived neural cells from patients and healthy donors now allow disease modeling using human samples that can be used for drug discovery.

scholarly journals DNA Methylation in LIME1 and SPTBN2 Genes Is Associated with Attention Deficit in Children

Children ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 92
Author(s):  
Sung-Chou Li ◽  
Ho-Chang Kuo ◽  
Lien-Hung Huang ◽  
Wen-Jiun Chou ◽  
Sheng-Yu Lee ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Attention Deficit ◽  
Performance Test ◽  
Neurodevelopmental Disorder ◽  
Continuous Performance Test ◽  
Attention Deficits ◽  
Clinical Settings ◽  
Hyperactivity Disorder ◽  
Cpg Sites ◽  
Healthy Control

DNA methylation levels are associated with neurodevelopment. Attention-deficit/hyperactivity disorder (ADHD), characterized by attention deficits, is a common neurodevelopmental disorder. We used methylation microarray and pyrosequencing to detect peripheral blood DNA methylation markers of ADHD. DNA methylation profiling data from the microarray assays identified potential differentially methylated CpG sites between 12 ADHD patients and 9 controls. Five candidate CpG sites (cg00446123, cg20513976, cg07922513, cg17096979, and cg02506324) in four genes (LIME1, KCNAB2, CAPN9, and SPTBN2) were further examined with pyrosequencing. The attention of patients were tested using the Conners’ Continuous Performance Test (CPT). In total, 126 ADHD patients with a mean age of 9.2 years (78.6% males) and 72 healthy control subjects with a mean age of 9.3 years (62.5% males) were recruited. When all participants were categorized by their CPT performance, the DNA methylation levels in LIME1 (cg00446123 and cg20513976) were found to be significantly higher and those in SPTBN2 (cg02506324) were significantly lower in children with worse CPT performance. Therefore, DNA methylation of two CpG sites in LIME1 and one CpG site in SPTBN2 is associated with attention deficits in children. DNA methylation biomarkers may assist in identifying attention deficits of children in clinical settings.

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 Integrative analysis identifies key molecular signatures underlying neurodevelopmental deficits in fragile X syndrome

2019 ◽  
Author(s):  
Kagistia Hana Utami ◽  
Niels H. Skotte ◽  
Ana R. Colaço ◽  
Nur Amirah Binte Mohammad Yusof ◽  
Bernice Sim ◽  
...  
Keyword(s):  
Fragile X Syndrome ◽  
Fragile X ◽  
Neurodevelopmental Disorder ◽  
Embryonic Stem ◽  
Neural Progenitor Cell ◽  
Integrative Analysis ◽  
Network Activity ◽  
Neural Cells ◽  
Molecular Signatures ◽  
Neurodevelopmental Abnormalities

AbstractFragile X syndrome (FXS) is an incurable neurodevelopmental disorder with no effective treatment. FXS is caused by epigenetic silencing ofFMR1and loss of FMRP expression. To investigate the consequences of FMRP deficiency in the context of human physiology, we established isogenicFMR1knockout (FMR1KO) human embryonic stem cells (hESCs). Integrative analysis of the transcriptomic and proteomic profiles of hESC-derived FMRP-deficient neurons revealed several dysregulated pathways important for brain development including processes related to axon development, neurotransmission, and the cell cycle. We functionally validated alterations in a number of these pathways, showing abnormal neural rosette formation and increased neural progenitor cell proliferation inFMR1KO cells. We further demonstrated neurite outgrowth and branching deficits along with impaired electrophysiological network activity in FMRP-deficient neurons. Using isogenicFMR1KO hESC-derived neurons, we reveal key molecular signatures and neurodevelopmental abnormalities arising from loss of FMRP. We anticipate that theFMR1KO hESCs and the neuronal transcriptome and proteome datasets will provide a platform to delineate the pathophysiology of FXS in human neural cells.

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