19 results on '"Nicouleau M"'
Search Results
2. Disruption of POGZ Is Associated with Intellectual Disability and Autism Spectrum Disorders
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Stessman, H.A., Willemsen, M.H., Fenckova, M., Penn, O., Hoischen, A., Xiong, B., Wang, T., Hoekzema, K., Vives, L., Vogel, I., Brunner, H.G., Burgt, I. van der, Ockeloen, C.W., Schuurs-Hoeijmakers, J.H.M., Wassink-Ruiter, J.S., Stumpel, C., Stevens, S.J., Vles, H.S., Marcelis, C.M., Bokhoven, H. van, Cantagrel, V., Colleaux, L., Nicouleau, M., Lyonnet, S., Bernier, R.A., Gerdts, J., Coe, B.P., Romano, C, Alberti, A., Grillo, L., Scuderi, C., Nordenskjold, M., Kvarnung, M., Guo, H., Xia, K., Piton, A., Gerard, B., Genevieve, D., Delobel, B., Lehalle, D., Perrin, L., Prieur, F., Thevenon, J., Gecz, J., Shaw, M., Pfundt, R., Keren, B., Jacquette, A., Schenck, A., Eichler, E.E., Kleefstra, T., Stessman, H.A., Willemsen, M.H., Fenckova, M., Penn, O., Hoischen, A., Xiong, B., Wang, T., Hoekzema, K., Vives, L., Vogel, I., Brunner, H.G., Burgt, I. van der, Ockeloen, C.W., Schuurs-Hoeijmakers, J.H.M., Wassink-Ruiter, J.S., Stumpel, C., Stevens, S.J., Vles, H.S., Marcelis, C.M., Bokhoven, H. van, Cantagrel, V., Colleaux, L., Nicouleau, M., Lyonnet, S., Bernier, R.A., Gerdts, J., Coe, B.P., Romano, C, Alberti, A., Grillo, L., Scuderi, C., Nordenskjold, M., Kvarnung, M., Guo, H., Xia, K., Piton, A., Gerard, B., Genevieve, D., Delobel, B., Lehalle, D., Perrin, L., Prieur, F., Thevenon, J., Gecz, J., Shaw, M., Pfundt, R., Keren, B., Jacquette, A., Schenck, A., Eichler, E.E., and Kleefstra, T.
- Abstract
Item does not contain fulltext, Intellectual disability (ID) and autism spectrum disorders (ASD) are genetically heterogeneous, and a significant number of genes have been associated with both conditions. A few mutations in POGZ have been reported in recent exome studies; however, these studies do not provide detailed clinical information. We collected the clinical and molecular data of 25 individuals with disruptive mutations in POGZ by diagnostic whole-exome, whole-genome, or targeted sequencing of 5,223 individuals with neurodevelopmental disorders (ID primarily) or by targeted resequencing of this locus in 12,041 individuals with ASD and/or ID. The rarity of disruptive mutations among unaffected individuals (2/49,401) highlights the significance (p = 4.19 x 10(-13); odds ratio = 35.8) and penetrance (65.9%) of this genetic subtype with respect to ASD and ID. By studying the entire cohort, we defined common phenotypic features of POGZ individuals, including variable levels of developmental delay (DD) and more severe speech and language delay in comparison to the severity of motor delay and coordination issues. We also identified significant associations with vision problems, microcephaly, hyperactivity, a tendency to obesity, and feeding difficulties. Some features might be explained by the high expression of POGZ, particularly in the cerebellum and pituitary, early in fetal brain development. We conducted parallel studies in Drosophila by inducing conditional knockdown of the POGZ ortholog row, further confirming that dosage of POGZ, specifically in neurons, is essential for normal learning in a habituation paradigm. Combined, the data underscore the pathogenicity of loss-of-function mutations in POGZ and define a POGZ-related phenotype enriched in specific features.
- Published
- 2016
3. Ciliome resequencing: A lifeline for molecular diagnosis in LCA
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Perrault, I, primary, Hanein, S, additional, Nicouleau, M, additional, Saunier, S, additional, Bole, C, additional, Nitschké, P, additional, Xerri, O, additional, Delphin, N, additional, Munnich, A, additional, Kaplan, J, additional, and Rozet, JM, additional
- Published
- 2015
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4. Identification of high-performing antibodies for SPARC-related modular calcium-binding protein 1 (SMOC-1) for use in Western Blot and immunoprecipitation.
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Ayoubi R, González Bolívar S, Nicouleau M, Southern K, and Laflamme C
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- Humans, Calcium-Binding Proteins immunology, Animals, Alzheimer Disease diagnosis, Immunoprecipitation methods, Blotting, Western, Antibodies immunology
- Abstract
SPARC-related modular calcium-binding protein 1, otherwise known as SMOC-1, is a secreted glycoprotein involved in various cell biological processes including cell-matrix interactions, osteoblast differentiation, embryonic development, and homeostasis. SMOC-1 was found to be elevated in asymptomatic Alzheimer's disease (AD) patient cortex as well as being enriched in amyloid plaques and in AD patientcerebrospinal fluid, arguing for SMOC-1 as a promising biomarker for AD. Having access to high-quality SMOC-1 antibodies is crucial for the scientific community. It can ensure the consistency and reliability of SMOC-1 research, and further the exploration of its potential as both a therapeutic target or diagnostic marker.. In this study, we characterized seven SMOC-1 commercial antibodies for Western blot and immunoprecipitation, using a standardized experimental protocol based on comparing read-outs in knockout cell lines and isogenic parental controls. We identified successful antibodies in the tested applications and encourage readers to use this report as a guide to select the most appropriate antibody for their specific needs., Competing Interests: Competing interests: For this project, the laboratory of Peter McPherson developed partnerships with high-quality antibody manufacturers and knockout cell line providers. The partners provide antibodies and knockout cell lines to the McPherson laboratory at no cost. These partners include: - Abcam -Aviva Systems Biology -Bio Techne -Cell Signalling Technology -Developmental Studies Hybridoma Bank -GeneTex – Horizon Discovery – Proteintech – Synaptic Systems -Thermo Fisher Scientific., (Copyright: © 2024 Ayoubi R et al.)
- Published
- 2024
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5. An Inducible Luminescent System to Explore Parkinson's Disease-Associated Genes.
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Gandy A, Maussion G, Al-Habyan S, Nicouleau M, You Z, Chen CX, Abdian N, Aprahamian N, Krahn AI, Larocque L, Durcan TM, and Deneault E
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- Humans, Glucosylceramidase genetics, Glucosylceramidase metabolism, alpha-Synuclein metabolism, alpha-Synuclein genetics, Leucine-Rich Repeat Serine-Threonine Protein Kinase-2 genetics, Leucine-Rich Repeat Serine-Threonine Protein Kinase-2 metabolism, Neurons metabolism, Ubiquitin-Protein Ligases genetics, Ubiquitin-Protein Ligases metabolism, Vesicular Transport Proteins genetics, Vesicular Transport Proteins metabolism, Protein Kinases, Parkinson Disease genetics, Parkinson Disease metabolism, Parkinson Disease pathology, Induced Pluripotent Stem Cells metabolism
- Abstract
With emerging genetic association studies, new genes and pathways are revealed as causative factors in the development of Parkinson's disease (PD). However, many of these PD genes are poorly characterized in terms of their function, subcellular localization, and interaction with other components in cellular pathways. This represents a major obstacle towards a better understanding of the molecular causes of PD, with deeper molecular studies often hindered by a lack of high-quality, validated antibodies for detecting the corresponding proteins of interest. In this study, we leveraged the nanoluciferase-derived LgBiT-HiBiT system by generating a cohort of tagged PD genes in both induced pluripotent stem cells (iPSCs) and iPSC-derived neuronal cells. To promote luminescence signals within cells, a master iPSC line was generated, in which LgBiT expression is under the control of a doxycycline-inducible promoter. LgBiT could bind to HiBiT when present either alone or when tagged onto different PD-associated proteins encoded by the genes GBA1 , GPNMB , LRRK2 , PINK1 , PRKN , SNCA , VPS13C , and VPS35 . Several HiBiT-tagged proteins could already generate luminescence in iPSCs in response to the doxycycline induction of LgBiT, with the enzyme glucosylceramidase beta 1 (GCase), encoded by GBA1 , being one such example. Moreover, the GCase chaperone ambroxol elicited an increase in the luminescence signal in HiBiT-tagged GBA1 cells, correlating with an increase in the levels of GCase in dopaminergic cells. Taken together, we have developed and validated a Doxycycline-inducible luminescence system to serve as a sensitive assay for the quantification, localization, and activity of HiBiT-tagged PD-associated proteins with reliable sensitivity and efficiency.
- Published
- 2024
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6. A dynamic in vitro model of Down syndrome neurogenesis with trisomy 21 gene dosage correction.
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Bansal P, Banda EC, Glatt-Deeley HR, Stoddard CE, Linsley JW, Arora N, Deleschaux C, Ahern DT, Kondaveeti Y, Massey RE, Nicouleau M, Wang S, Sabariego-Navarro M, Dierssen M, Finkbeiner S, and Pinter SF
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- Humans, Chromosomes, Human, Pair 21 genetics, Neurons metabolism, Down Syndrome genetics, Neurogenesis genetics, Induced Pluripotent Stem Cells metabolism, Induced Pluripotent Stem Cells cytology, Gene Dosage, RNA, Long Noncoding genetics, Cell Differentiation genetics
- Abstract
Excess gene dosage from chromosome 21 (chr21) causes Down syndrome (DS), spanning developmental and acute phenotypes in terminal cell types. Which phenotypes remain amenable to intervention after development is unknown. To address this question in a model of DS neurogenesis, we derived trisomy 21 (T21) human induced pluripotent stem cells (iPSCs) alongside, otherwise, isogenic euploid controls from mosaic DS fibroblasts and equipped one chr21 copy with an inducible XIST transgene. Monoallelic chr21 silencing by XIST is near-complete and irreversible in iPSCs. Differential expression reveals that T21 neural lineages and iPSCs share suppressed translation and mitochondrial pathways and activate cellular stress responses. When XIST is induced before the neural progenitor stage, T21 dosage correction suppresses a pronounced skew toward astrogenesis in neural differentiation. Because our transgene remains inducible in postmitotic T21 neurons and astrocytes, we demonstrate that XIST efficiently represses genes even after terminal differentiation, which will empower exploration of cell type-specific T21 phenotypes that remain responsive to chr21 dosage.
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- 2024
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7. An adapted protocol to derive microglia from stem cells and its application in the study of CSF1R-related disorders.
- Author
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Dorion MF, Casas D, Shlaifer I, Yaqubi M, Fleming P, Karpilovsky N, Chen CX, Nicouleau M, Piscopo VEC, MacDougall EJ, Alluli A, Goldsmith TM, Schneider A, Dorion S, Aprahamian N, MacDonald A, Thomas RA, Dudley RWR, Hall JA, Fon EA, Antel JP, Stratton JA, Durcan TM, La Piana R, and Healy LM
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- Adult, Humans, Cell Differentiation, Phosphorylation, Stem Cells metabolism, Leukoencephalopathies metabolism, Leukoencephalopathies pathology, Microglia metabolism
- Abstract
Background: Induced pluripotent stem cell-derived microglia (iMGL) represent an excellent tool in studying microglial function in health and disease. Yet, since differentiation and survival of iMGL are highly reliant on colony-stimulating factor 1 receptor (CSF1R) signaling, it is difficult to use iMGL to study microglial dysfunction associated with pathogenic defects in CSF1R., Methods: Serial modifications to an existing iMGL protocol were made, including but not limited to changes in growth factor combination to drive microglial differentiation, until successful derivation of microglia-like cells from an adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) patient carrying a c.2350G > A (p.V784M) CSF1R variant. Using healthy control lines, the quality of the new iMGL protocol was validated through cell yield assessment, measurement of microglia marker expression, transcriptomic comparison to primary microglia, and evaluation of inflammatory and phagocytic activities. Similarly, molecular and functional characterization of the ALSP patient-derived iMGL was carried out in comparison to healthy control iMGL., Results: The newly devised protocol allowed the generation of iMGL with enhanced transcriptomic similarity to cultured primary human microglia and with higher scavenging and inflammatory competence at ~ threefold greater yield compared to the original protocol. Using this protocol, decreased CSF1R autophosphorylation and cell surface expression was observed in iMGL derived from the ALSP patient compared to those derived from healthy controls. Additionally, ALSP patient-derived iMGL presented a migratory defect accompanying a temporal reduction in purinergic receptor P2Y12 (P2RY12) expression, a heightened capacity to internalize myelin, as well as heightened inflammatory response to Pam
3 CSK4 . Poor P2RY12 expression was confirmed to be a consequence of CSF1R haploinsufficiency, as this feature was also observed following CSF1R knockdown or inhibition in mature control iMGL, and in CSF1RWT/KO and CSF1RWT/E633K iMGL compared to their respective isogenic controls., Conclusions: We optimized a pre-existing iMGL protocol, generating a powerful tool to study microglial involvement in human neurological diseases. Using the optimized protocol, we have generated for the first time iMGL from an ALSP patient carrying a pathogenic CSF1R variant, with preliminary characterization pointing toward functional alterations in migratory, phagocytic and inflammatory activities., (© 2024. The Author(s).)- Published
- 2024
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8. De novo variants in DENND5B cause a neurodevelopmental disorder.
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Scala M, Tomati V, Ferla M, Lena M, Cohen JS, Fatemi A, Brokamp E, Bican A, Phillips JA 3rd, Koziura ME, Nicouleau M, Rio M, Siquier K, Boddaert N, Musante I, Tamburro S, Baldassari S, Iacomino M, Scudieri P, Rosenfeld JA, Bellus G, Reed S, Al Saif H, Russo RS, Walsh MB, Cantagrel V, Crunk A, Gustincich S, Ruggiero SM, Fitzgerald MP, Helbig I, Striano P, Severino M, Salpietro V, Pedemonte N, and Zara F
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- Humans, Brain metabolism, Guanine Nucleotide Exchange Factors genetics, Guanine Nucleotide Exchange Factors metabolism, Lipids, rab GTP-Binding Proteins metabolism, Neurodevelopmental Disorders genetics, Neurodevelopmental Disorders metabolism, Epilepsy genetics, Epilepsy metabolism, Intellectual Disability genetics, Intellectual Disability metabolism
- Abstract
The Rab family of guanosine triphosphatases (GTPases) includes key regulators of intracellular transport and membrane trafficking targeting specific steps in exocytic, endocytic, and recycling pathways. DENND5B (Rab6-interacting Protein 1B-like protein, R6IP1B) is the longest isoform of DENND5, an evolutionarily conserved DENN domain-containing guanine nucleotide exchange factor (GEF) that is highly expressed in the brain. Through exome sequencing and international matchmaking platforms, we identified five de novo variants in DENND5B in a cohort of five unrelated individuals with neurodevelopmental phenotypes featuring cognitive impairment, dysmorphism, abnormal behavior, variable epilepsy, white matter abnormalities, and cortical gyration defects. We used biochemical assays and confocal microscopy to assess the impact of DENND5B variants on protein accumulation and distribution. Then, exploiting fluorescent lipid cargoes coupled to high-content imaging and analysis in living cells, we investigated whether DENND5B variants affected the dynamics of vesicle-mediated intracellular transport of specific cargoes. We further generated an in silico model to investigate the consequences of DENND5B variants on the DENND5B-RAB39A interaction. Biochemical analysis showed decreased protein levels of DENND5B mutants in various cell types. Functional investigation of DENND5B variants revealed defective intracellular vesicle trafficking, with significant impairment of lipid uptake and distribution. Although none of the variants affected the DENND5B-RAB39A interface, all were predicted to disrupt protein folding. Overall, our findings indicate that DENND5B variants perturb intracellular membrane trafficking pathways and cause a complex neurodevelopmental syndrome with variable epilepsy and white matter involvement., Competing Interests: Declaration of interests A.C. is an employee of GeneDx, LLC. The Department of Molecular and Human Genetics at Baylor College of Medicine receives revenue from clinical genetic testing completed at Baylor Genetics Laboratories., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)
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- 2024
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9. Transcriptional Dysregulation and Impaired Neuronal Activity in FMR1 Knock-Out and Fragile X Patients' iPSC-Derived Models.
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Maussion G, Rocha C, Abdian N, Yang D, Turk J, Carrillo Valenzuela D, Pimentel L, You Z, Morquette B, Nicouleau M, Deneault E, Higgins S, Chen CX, Reintsch WE, Ho S, Soubannier V, Lépine S, Modrusan Z, Lund J, Stephenson W, Schubert R, and Durcan TM
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- Humans, Animals, Mice, Neurons metabolism, Fragile X Mental Retardation Protein genetics, Fragile X Mental Retardation Protein metabolism, Neurogenesis genetics, RNA, Messenger genetics, Mice, Knockout, Induced Pluripotent Stem Cells metabolism, Fragile X Syndrome genetics, Fragile X Syndrome metabolism
- Abstract
Fragile X syndrome (FXS) is caused by a repression of the FMR1 gene that codes the Fragile X mental retardation protein (FMRP), an RNA binding protein involved in processes that are crucial for proper brain development. To better understand the consequences of the absence of FMRP, we analyzed gene expression profiles and activities of cortical neural progenitor cells (NPCs) and neurons obtained from FXS patients' induced pluripotent stem cells (IPSCs) and IPSC-derived cells from FMR1 knock-out engineered using CRISPR-CAS9 technology. Multielectrode array recordings revealed in FMR1 KO and FXS patient cells, decreased mean firing rates; activities blocked by tetrodotoxin application. Increased expression of presynaptic mRNA and transcription factors involved in the forebrain specification and decreased levels of mRNA coding AMPA and NMDA subunits were observed using RNA sequencing on FMR1 KO neurons and validated using quantitative PCR in both models. Intriguingly, 40% of the differentially expressed genes were commonly deregulated between NPCs and differentiating neurons with significant enrichments in FMRP targets and autism-related genes found amongst downregulated genes. Our findings suggest that the absence of FMRP affects transcriptional profiles since the NPC stage, and leads to impaired activity and neuronal differentiation over time, which illustrates the critical role of FMRP protein in neuronal development.
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- 2023
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10. Generation of patient-derived pluripotent stem cell-lines and CRISPR modified isogenic controls with mutations in the Parkinson's associated GBA gene.
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X-Q Chen C, Deneault E, Abdian N, You Z, Sirois J, Nicouleau M, Shlaifer I, Villegas L, Boivin MN, Gaborieau L, Karamchandani J, Beitel LK, Fon EA, and Durcan TM
- Subjects
- Humans, Glucose, Glucosylceramidase genetics, Glucosylceramidase metabolism, Glucosylceramides metabolism, Mutation genetics, Induced Pluripotent Stem Cells metabolism, Parkinson Disease pathology
- Abstract
The GBA gene encodes the lysosomal enzyme glucocerebrosidase (GCase), responsible for the hydrolysis of glucocerebroside to glucose and ceramide. Heterozygous GBA mutations have been associated with the development of Parkinson's disease (PD) and dementia with Lewy bodies (DLB). We generated two induced pluripotent stem cell (iPSC) lines from PD patients carrying heterozygous GBA W378G or N370S mutations and subsequently produced isogenic control lines using CRISPR/Cas9 genome editing. The patient-derived iPSCs and isogenic control lines maintained full pluripotency, normal karyotypes, and differentiation capacity. All iPSC lines could be differentiated into dopaminergic neurons, thus providing valuable tools for studying PD pathogenesis., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2022
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11. A streamlined CRISPR workflow to introduce mutations and generate isogenic iPSCs for modeling amyotrophic lateral sclerosis.
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Deneault E, Chaineau M, Nicouleau M, Castellanos Montiel MJ, Franco Flores AK, Haghi G, Chen CX, Abdian N, Shlaifer I, Beitel LK, and Durcan TM
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- Clustered Regularly Interspaced Short Palindromic Repeats genetics, Humans, Mutation, Superoxide Dismutase-1 genetics, Superoxide Dismutase-1 metabolism, Workflow, Amyotrophic Lateral Sclerosis genetics, Amyotrophic Lateral Sclerosis therapy, Induced Pluripotent Stem Cells physiology
- Abstract
Amyotrophic lateral sclerosis (ALS) represents a complex neurodegenerative disorder with significant genetic heterogeneity. To date, both the genetic etiology and the underlying molecular mechanisms driving this disease remain poorly understood, although in recent years several studies have highlighted a number of genetic mutations causative for ALS. With these mutations pointing to potential pathways that may be affected within individuals with ALS, having the ability to generate human neurons and other disease relevant cells containing these mutations becomes even more critical if new therapies are to emerge. Recent developments with the advent of induced pluripotent stem cells (iPSCs) and clustered regularly interspaced short palindromic repeats (CRISPR) gene editing fields gave us the tools to introduce or correct a specific mutation at any site within the genome of an iPSC, and thus model the specific contribution of risk mutations. In this study we describe a rapid and efficient way to either introduce a mutation into a control line, or to correct an allele-specific mutation, generating an isogenic control line from patient-derived iPSCs with a given mutation. The mutations introduced were the G94A (also known as G93A) mutation into SOD1 or H517Q into FUS, and the mutation corrected was a patient iPSC line with I114T mutation in SOD1. A combination of small molecules and growth factors were used to guide a stepwise differentiation of the edited cells into motor neurons in order to demonstrate that disease-relevant cells could be generated for downstream applications. Through a combination of iPSCs and CRISPR editing, the cells generated here will provide fundamental insights into the molecular mechanisms underlying neuron degeneration in ALS., (Copyright © 2021 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2022
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12. Midbrain organoids with an SNCA gene triplication model key features of synucleinopathy.
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Mohamed NV, Sirois J, Ramamurthy J, Mathur M, Lépine P, Deneault E, Maussion G, Nicouleau M, Chen CX, Abdian N, Soubannier V, Cai E, Nami H, Thomas RA, Wen D, Tabatabaei M, Beitel LK, Singh Dolt K, Karamchandani J, Stratton JA, Kunath T, Fon EA, and Durcan TM
- Abstract
SNCA , the first gene associated with Parkinson's disease, encodes the α-synuclein protein, the predominant component within pathological inclusions termed Lewy bodies. The presence of Lewy bodies is one of the classical hallmarks found in the brain of patients with Parkinson's disease, and Lewy bodies have also been observed in patients with other synucleinopathies. However, the study of α-synuclein pathology in cells has relied largely on two-dimensional culture models, which typically lack the cellular diversity and complex spatial environment found in the brain. Here, to address this gap, we use three-dimensional midbrain organoids, differentiated from human-induced pluripotent stem cells derived from patients carrying a triplication of the SNCA gene and from CRISPR/Cas9 corrected isogenic control iPSCs. These human midbrain organoids recapitulate key features of α-synuclein pathology observed in the brains of patients with synucleinopathies. In particular, we find that SNCA triplication human midbrain organoids express elevated levels of α-synuclein and exhibit an age-dependent increase in α-synuclein aggregation, manifested by the presence of both oligomeric and phosphorylated forms of α-synuclein. These phosphorylated α-synuclein aggregates were found in both neurons and glial cells and their time-dependent accumulation correlated with a selective reduction in dopaminergic neuron numbers. Thus, human midbrain organoids from patients carrying SNCA gene multiplication can reliably model key pathological features of Parkinson's disease and provide a powerful system to study the pathogenesis of synucleinopathies., (© The Author(s) (2021). Published by Oxford University Press on behalf of the Guarantors of Brain.)
- Published
- 2021
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13. Identification of amyloid beta in small extracellular vesicles via Raman spectroscopy.
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Imanbekova M, Suarasan S, Rojalin T, Mizenko RR, Hilt S, Mathur M, Lepine P, Nicouleau M, Mohamed NV, Durcan TM, Carney RP, Voss JC, and Wachsmann-Hogiu S
- Abstract
One of the hallmarks of Alzheimer's disease (AD) pathogenesis is believed to be the production and deposition of amyloid-beta (Aβ) peptide into extracellular plaques. Existing research indicates that extracellular vesicles (EVs) can carry Aβ associated with AD. However, characterization of the EVs-associated Aβ and its conformational variants has yet to be realized. Raman spectroscopy is a label-free and non-destructive method that is able to assess the biochemical composition of EVs. This study reports for the first time the Raman spectroscopic fingerprint of the Aβ present in the molecular cargo of small extracellular vesicles (sEVs). Raman spectra were measured from sEVs isolated from Alzheimer's disease cell culture model, where secretion of Aβ is regulated by tetracycline promoter, and from midbrain organoids. The averaged spectra of each sEV group showed considerable variation as a reflection of the biochemical content of sEVs. Spectral analysis identified more intense Raman peaks at 1650 cm
-1 and 2930 cm-1 attributable to the Aβ peptide incorporated in sEVs produced by the Alzheimer's cell culture model. Subsequent analysis of the spectra by principal component analysis differentiated the sEVs of the Alzheimer's disease cell culture model from the control groups of sEVs. Moreover, the results indicate that Aβ associated with secreted sEVs has a α-helical secondary structure and the size of a monomer or small oligomer. Furthermore, by analyzing the lipid content of sEVs we identified altered fatty acid chain lengths in sEVs that carry Aβ that may affect the fluidity of the EV membrane. Overall, our findings provide evidence supporting the use of Raman spectroscopy for the identification and characterization of sEVs associated with potential biomarkers of neurological disorders such as toxic proteins., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (This journal is © The Royal Society of Chemistry.)- Published
- 2021
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14. High N-glycan multiplicity is critical for neuronal adhesion and sensitizes the developing cerebellum to N-glycosylation defect.
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Medina-Cano D, Ucuncu E, Nguyen LS, Nicouleau M, Lipecka J, Bizot JC, Thiel C, Foulquier F, Lefort N, Faivre-Sarrailh C, Colleaux L, Guerrera IC, and Cantagrel V
- Subjects
- 3-Oxo-5-alpha-Steroid 4-Dehydrogenase deficiency, 3-Oxo-5-alpha-Steroid 4-Dehydrogenase metabolism, Animals, Axon Guidance, Cell Adhesion, Cell Adhesion Molecules metabolism, Cell Differentiation, Cell Membrane metabolism, Cerebellum embryology, Cytoplasmic Granules metabolism, Gene Deletion, Glycosylation, Immunoglobulins metabolism, Induced Pluripotent Stem Cells metabolism, Membrane Proteins deficiency, Membrane Proteins metabolism, Mice, Knockout, Motor Activity, Mutation genetics, Neural Pathways metabolism, Proteomics, Purkinje Cells metabolism, Reproducibility of Results, Unfolded Protein Response, Cerebellum metabolism, Neurons cytology, Neurons metabolism, Polysaccharides metabolism
- Abstract
Proper brain development relies highly on protein N-glycosylation to sustain neuronal migration, axon guidance and synaptic physiology. Impairing the N-glycosylation pathway at early steps produces broad neurological symptoms identified in congenital disorders of glycosylation. However, little is known about the molecular mechanisms underlying these defects. We generated a cerebellum specific knockout mouse for Srd5a3 , a gene involved in the initiation of N-glycosylation. In addition to motor coordination defects and abnormal granule cell development, Srd5a3 deletion causes mild N-glycosylation impairment without significantly altering ER homeostasis. Using proteomic approaches, we identified that Srd5a3 loss affects a subset of glycoproteins with high N-glycans multiplicity per protein and decreased protein abundance or N-glycosylation level. As IgSF-CAM adhesion proteins are critical for neuron adhesion and highly N-glycosylated, we observed impaired IgSF-CAM-mediated neurite outgrowth and axon guidance in Srd5a3 mutant cerebellum. Our results link high N-glycan multiplicity to fine-tuned neural cell adhesion during mammalian brain development., Competing Interests: DM, EU, LN, MN, JL, JB, CT, FF, NL, CF, LC, IG, VC No competing interests declared, (© 2018, Medina-Cano et al.)
- Published
- 2018
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15. De novo mutation screening in childhood-onset cerebellar atrophy identifies gain-of-function mutations in the CACNA1G calcium channel gene.
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Chemin J, Siquier-Pernet K, Nicouleau M, Barcia G, Ahmad A, Medina-Cano D, Hanein S, Altin N, Hubert L, Bole-Feysot C, Fourage C, Nitschké P, Thevenon J, Rio M, Blanc P, Vidal C, Bahi-Buisson N, Desguerre I, Munnich A, Lyonnet S, Boddaert N, Fassi E, Shinawi M, Zimmerman H, Amiel J, Faivre L, Colleaux L, Lory P, and Cantagrel V
- Subjects
- Adolescent, Adult, Atrophy pathology, Brain pathology, Calcium metabolism, Calcium Channels genetics, Calcium Channels, T-Type metabolism, Cerebellar Ataxia physiopathology, Cerebellar Diseases complications, Cerebellum pathology, Child, Child, Preschool, Cohort Studies, Developmental Disabilities genetics, Female, Gain of Function Mutation genetics, Humans, Intellectual Disability genetics, Male, Microcephaly genetics, Mutation, Pedigree, Phenotype, Purkinje Cells pathology, Calcium Channels, T-Type genetics, Cerebellar Ataxia genetics
- Abstract
Cerebellar atrophy is a key neuroradiological finding usually associated with cerebellar ataxia and cognitive development defect in children. Unlike the adult forms, early onset cerebellar atrophies are classically described as mostly autosomal recessive conditions and the exact contribution of de novo mutations to this phenotype has not been assessed. In contrast, recent studies pinpoint the high prevalence of pathogenic de novo mutations in other developmental disorders such as intellectual disability, autism spectrum disorders and epilepsy. Here, we investigated a cohort of 47 patients with early onset cerebellar atrophy and/or hypoplasia using a custom gene panel as well as whole exome sequencing. De novo mutations were identified in 35% of patients while 27% had mutations inherited in an autosomal recessive manner. Understanding if these de novo events act through a loss or a gain of function effect is critical for treatment considerations. To gain a better insight into the disease mechanisms causing these cerebellar defects, we focused on CACNA1G, a gene not yet associated with the early-onset form. This gene encodes the Cav3.1 subunit of T-type calcium channels highly expressed in Purkinje neurons and deep cerebellar nuclei. We identified four patients with de novo CACNA1G mutations. They all display severe motor and cognitive impairment, cerebellar atrophy as well as variable features such as facial dysmorphisms, digital anomalies, microcephaly and epilepsy. Three subjects share a recurrent c.2881G>A/p.Ala961Thr variant while the fourth patient has the c.4591A>G/p.Met1531Val variant. Both mutations drastically impaired channel inactivation properties with significantly slower kinetics (∼5 times) and negatively shifted potential for half-inactivation (>10 mV). In addition, these two mutations increase neuronal firing in a cerebellar nuclear neuron model and promote a larger window current fully inhibited by TTA-P2, a selective T-type channel blocker. This study highlights the prevalence of de novo mutations in early-onset cerebellar atrophy and demonstrates that A961T and M1531V are gain of function mutations. Moreover, it reveals that aberrant activity of Cav3.1 channels can markedly alter brain development and suggests that this condition could be amenable to treatment.
- Published
- 2018
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16. Utility of whole exome sequencing for the early diagnosis of pediatric-onset cerebellar atrophy associated with developmental delay in an inbred population.
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Megahed H, Nicouleau M, Barcia G, Medina-Cano D, Siquier-Pernet K, Bole-Feysot C, Parisot M, Masson C, Nitschké P, Rio M, Bahi-Buisson N, Desguerre I, Munnich A, Boddaert N, Colleaux L, and Cantagrel V
- Subjects
- Brain metabolism, Brain pathology, Cerebellar Ataxia diagnosis, Cerebellar Ataxia genetics, Child, Preschool, Early Diagnosis, Female, Humans, Magnetic Resonance Imaging, Male, Phenotype, Atrophy diagnosis, Atrophy genetics, Developmental Disabilities diagnosis, Developmental Disabilities genetics, Exome genetics, Mutation genetics, Sequence Analysis, DNA methods
- Abstract
Background: Cerebellar atrophy and developmental delay are commonly associated features in large numbers of genetic diseases that frequently also include epilepsy. These defects are highly heterogeneous on both the genetic and clinical levels. Patients with these signs also typically present with non-specific neuroimaging results that can help prioritize further investigation but don't suggest a specific molecular diagnosis., Methods: To genetically explore a cohort of 18 Egyptian families with undiagnosed cerebellar atrophy identified on MRI, we sequenced probands and some non-affected family members via high-coverage whole exome sequencing (WES; >97 % of the exome covered at least by 30x). Patients were mostly from consanguineous families, either sporadic or multiplex. We analyzed WES data and filtered variants according to dominant and recessive inheritance models., Results: We successfully identified disease-causing mutations in half of the families screened (9/18). These mutations are located in seven different genes, PLA2G6 being the gene most frequently mutated (n = 3). We also identified a recurrent de novo mutation in the KIF1A gene and a molybdenum cofactor deficiency caused by the loss of the start codon in the MOCS2A open-reading frame in a mildly affected subject., Conclusions: This study illustrates the necessity of screening for dominant mutations in WES data from consanguineous families. Our identification of a patient with a mild and improving phenotype carrying a previously characterized severe loss of function mutation also broadens the clinical spectrum associated with molybdenum cofactor deficiency.
- Published
- 2016
- Full Text
- View/download PDF
17. Disruption of POGZ Is Associated with Intellectual Disability and Autism Spectrum Disorders.
- Author
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Stessman HAF, Willemsen MH, Fenckova M, Penn O, Hoischen A, Xiong B, Wang T, Hoekzema K, Vives L, Vogel I, Brunner HG, van der Burgt I, Ockeloen CW, Schuurs-Hoeijmakers JH, Klein Wassink-Ruiter JS, Stumpel C, Stevens SJC, Vles HS, Marcelis CM, van Bokhoven H, Cantagrel V, Colleaux L, Nicouleau M, Lyonnet S, Bernier RA, Gerdts J, Coe BP, Romano C, Alberti A, Grillo L, Scuderi C, Nordenskjöld M, Kvarnung M, Guo H, Xia K, Piton A, Gerard B, Genevieve D, Delobel B, Lehalle D, Perrin L, Prieur F, Thevenon J, Gecz J, Shaw M, Pfundt R, Keren B, Jacquette A, Schenck A, Eichler EE, and Kleefstra T
- Subjects
- Adolescent, Adult, Animals, Autism Spectrum Disorder diagnosis, Child, Child, Preschool, Cohort Studies, Down-Regulation, Drosophila genetics, Drosophila Proteins genetics, Drosophila Proteins metabolism, Exome, Female, Gene Knockdown Techniques, Genome-Wide Association Study, Humans, Infant, Intellectual Disability diagnosis, Language Development Disorders diagnosis, Language Development Disorders genetics, Linear Models, Male, Microcephaly diagnosis, Microcephaly genetics, Mutation, Phenotype, Transcription Factors genetics, Transcription Factors metabolism, Autism Spectrum Disorder genetics, Intellectual Disability genetics, Transposases genetics
- Abstract
Intellectual disability (ID) and autism spectrum disorders (ASD) are genetically heterogeneous, and a significant number of genes have been associated with both conditions. A few mutations in POGZ have been reported in recent exome studies; however, these studies do not provide detailed clinical information. We collected the clinical and molecular data of 25 individuals with disruptive mutations in POGZ by diagnostic whole-exome, whole-genome, or targeted sequencing of 5,223 individuals with neurodevelopmental disorders (ID primarily) or by targeted resequencing of this locus in 12,041 individuals with ASD and/or ID. The rarity of disruptive mutations among unaffected individuals (2/49,401) highlights the significance (p = 4.19 × 10(-13); odds ratio = 35.8) and penetrance (65.9%) of this genetic subtype with respect to ASD and ID. By studying the entire cohort, we defined common phenotypic features of POGZ individuals, including variable levels of developmental delay (DD) and more severe speech and language delay in comparison to the severity of motor delay and coordination issues. We also identified significant associations with vision problems, microcephaly, hyperactivity, a tendency to obesity, and feeding difficulties. Some features might be explained by the high expression of POGZ, particularly in the cerebellum and pituitary, early in fetal brain development. We conducted parallel studies in Drosophila by inducing conditional knockdown of the POGZ ortholog row, further confirming that dosage of POGZ, specifically in neurons, is essential for normal learning in a habituation paradigm. Combined, the data underscore the pathogenicity of loss-of-function mutations in POGZ and define a POGZ-related phenotype enriched in specific features., (Copyright © 2016 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
18. Mutations in NMNAT1 cause Leber congenital amaurosis with early-onset severe macular and optic atrophy.
- Author
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Perrault I, Hanein S, Zanlonghi X, Serre V, Nicouleau M, Defoort-Delhemmes S, Delphin N, Fares-Taie L, Gerber S, Xerri O, Edelson C, Goldenberg A, Duncombe A, Le Meur G, Hamel C, Silva E, Nitschke P, Calvas P, Munnich A, Roche O, Dollfus H, Kaplan J, and Rozet JM
- Subjects
- Adolescent, Adult, Age of Onset, Child, Child, Preschool, Cohort Studies, Genetic Predisposition to Disease, Humans, Leber Congenital Amaurosis complications, Leber Congenital Amaurosis epidemiology, Macular Degeneration complications, Macular Degeneration epidemiology, Optic Atrophy complications, Optic Atrophy epidemiology, Polymorphism, Single Nucleotide physiology, Severity of Illness Index, Young Adult, Leber Congenital Amaurosis genetics, Macular Degeneration genetics, Mutation physiology, Nicotinamide-Nucleotide Adenylyltransferase genetics, Optic Atrophy genetics
- Abstract
In addition to its activity in nicotinamide adenine dinucleotide (NAD(+)) synthesis, the nuclear nicotinamide mononucleotide adenyltransferase NMNAT1 acts as a chaperone that protects against neuronal activity-induced degeneration. Here we report that compound heterozygous and homozygous NMNAT1 mutations cause severe neonatal neurodegeneration of the central retina and early-onset optic atrophy in 22 unrelated individuals. Their clinical presentation is consistent with Leber congenital amaurosis and suggests that the mutations affect neuroprotection of photoreceptor cells.
- Published
- 2012
- Full Text
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19. Highly diastereoselective Baldwin rearrangement of isoxazolines into cis-acylaziridines.
- Author
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Gayon E, Debleds O, Nicouleau M, Lamaty F, van der Lee A, Vrancken E, and Campagne JM
- Subjects
- Aziridines chemistry, Molecular Structure, Stereoisomerism, Aziridines chemical synthesis, Isoxazoles chemistry
- Abstract
An atom-economical and practical synthesis of cis-N-benzenesulfonamide acylaziridines through the Baldwin rearrangement of various N-benzenesulfonamide isoxazolines has been reported. A detailed experimental study revealed the beneficial effect of microwaves and pointed out the crucial role of the temperature in the reaction course. Moderate to good yields and excellent cis stereoselectivities were achieved for 13 examples.
- Published
- 2010
- Full Text
- View/download PDF
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