1
|
Kavanaugh BC, Elacio J, Best CR, St Pierre DG, Pescosolido MF, Ouyang Q, Biedermann J, Bradley RS, Liu JS, Jones RN, Morrow EM. Christianson syndrome across the lifespan: genetic mutations and longitudinal study in children, adolescents, and adults. J Med Genet 2024:jmg-2024-109973. [PMID: 39237363 DOI: 10.1136/jmg-2024-109973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Accepted: 08/14/2024] [Indexed: 09/07/2024]
Abstract
OBJECTIVES Mutations in the X-linked endosomal Na+/H+ exchanger 6 (NHE6) cause Christianson syndrome (CS). Here, in the largest study to date, we examine genetic diversity and clinical progression in CS into adulthood. METHOD Data were collected as part of the International Christianson Syndrome and NHE6 (SLC9A6) Gene Network Study. 44 individuals with 31 unique NHE6 mutations, age 2-32 years, were followed prospectively, herein reporting baseline, 1 year follow-up and retrospective natural history. RESULTS We present data on the CS phenotype with regard to physical growth and adaptive and motor regression across the lifespan including information on mortality. Longitudinal data on body weight and height were examined using a linear mixed model. The rate of growth across development was slow and resulted in prominently decreased age-normed height and weight by adulthood. Adaptive functioning was longitudinally examined; a majority of adult participants (18+ years) lost gross and fine motor skills over a 1 year follow-up. Previously defined core diagnostic criteria for CS (present in>85%)-namely non-verbal status, intellectual disability, epilepsy, postnatal microcephaly, ataxia, hyperkinesia-were universally present in age 6-16; however, an additional core feature of high pain tolerance was added (present in 91%). While neurologic examinations were consistent with cerebellar dysfunction, importantly, a majority of individuals (>50% older than 10) also had corticospinal tract abnormalities. Three participants died during the period of the study. CONCLUSIONS In this large and longitudinal study of CS, we begin to define the trajectory of symptoms and the adult phenotype thereby identifying critical targets for treatment.
Collapse
Affiliation(s)
- Brian C Kavanaugh
- Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, Rhode Island, USA
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, USA
| | - Jennifer Elacio
- Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, Rhode Island, USA
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, USA
| | - Carrie R Best
- Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, Rhode Island, USA
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, USA
| | - Danielle G St Pierre
- Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, Rhode Island, USA
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, USA
| | - Matthew F Pescosolido
- Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, Rhode Island, USA
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, USA
| | - Qing Ouyang
- Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, Rhode Island, USA
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, USA
| | - John Biedermann
- Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, Rhode Island, USA
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, USA
| | - Rebecca S Bradley
- Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, Rhode Island, USA
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, USA
| | - Judy S Liu
- Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, Rhode Island, USA
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, USA
- Department of Neurology, Rhode Island Hospital, Providence, Rhode Island, USA
| | - Richard N Jones
- Quantitative Sciences Program, Department of Psychiatry and Human Behavior and Department of Neurology, Brown University Warren Alpert Medical School, Providence, Rhode Island, USA
| | - Eric M Morrow
- Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, Rhode Island, USA
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, USA
| |
Collapse
|
2
|
Ma L, Kasula RK, Ouyang Q, Schmidt M, Morrow EM. GGA1 interacts with the endosomal Na+/H+ exchanger NHE6 governing localization to the endosome compartment. J Biol Chem 2024; 300:107552. [PMID: 39002678 PMCID: PMC11375261 DOI: 10.1016/j.jbc.2024.107552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 06/20/2024] [Accepted: 06/27/2024] [Indexed: 07/15/2024] Open
Abstract
Mutations in the endosomal Na+/H+ exchanger 6 (NHE6) cause Christianson syndrome, an X-linked neurological disorder. NHE6 functions in regulation of endosome acidification and maturation in neurons. Using yeast two-hybrid screening with the NHE6 carboxyl terminus as bait, we identify Golgi-associated, gamma adaptin ear-containing, ADP-ribosylation factor (ARF) binding protein 1 (GGA1) as an interacting partner for NHE6. We corroborated the NHE6-GGA1 interaction using: coimmunoprecipitation; overexpressed constructs in mammalian cells; and coimmunoprecipitation of endogenously expressed GGA1 and NHE6 from neuroblastoma cells, as well as from the mouse brain. We demonstrate that GGA1 interacts with organellar NHEs (NHE6, NHE7, and NHE9) and that there is significantly less interaction with cell-surface localized NHEs (NHE1 and NHE5). By constructing hybrid NHE1/NHE6 exchangers, we demonstrate the cytoplasmic tail of NHE6 interacts most strongly with GGA1. We demonstrate the colocalization of NHE6 and GGA1 in cultured, primary hippocampal neurons, using super-resolution microscopy. We test the hypothesis that the interaction of NHE6 and GGA1 functions in the localization of NHE6 to the endosome compartment. Using subcellular fractionation experiments, we show that NHE6 is mislocalized in GGA1 KO cells, wherein we find less NHE6 in endosomes, but more NHE6 transport to lysosomes, and more Golgi retention of NHE6, with increased exocytosis to the surface plasma membrane. Consistent with NHE6 mislocalization, and Golgi retention, we find the intraluminal pH in Golgi to be alkalinized in GGA1-null cells. Our study demonstrates a new interaction between NHE6 and GGA1 which functions in the localization of this intracellular NHE to the endosome compartment.
Collapse
Affiliation(s)
- Li Ma
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, USA; Center for Translational Neuroscience, Brown University, Providence, Rhode Island, USA
| | - Ravi Kiran Kasula
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, USA; Center for Translational Neuroscience, Brown University, Providence, Rhode Island, USA
| | - Qing Ouyang
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, USA; Center for Translational Neuroscience, Brown University, Providence, Rhode Island, USA
| | - Michael Schmidt
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, USA; Center for Translational Neuroscience, Brown University, Providence, Rhode Island, USA
| | - Eric M Morrow
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, USA; Center for Translational Neuroscience, Brown University, Providence, Rhode Island, USA.
| |
Collapse
|
3
|
Potenzieri A, Uccella S, Preiti D, Pisoni M, Rosati S, Lavarello C, Bartolucci M, Debellis D, Catalano F, Petretto A, Nobili L, Fellin T, Tucci V, Ramenghi LA, Savardi A, Cancedda L. Early IGF-1 receptor inhibition in mice mimics preterm human brain disorders and reveals a therapeutic target. SCIENCE ADVANCES 2024; 10:eadk8123. [PMID: 38427732 PMCID: PMC10906931 DOI: 10.1126/sciadv.adk8123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 01/29/2024] [Indexed: 03/03/2024]
Abstract
Besides recent advances in neonatal care, preterm newborns still develop sex-biased behavioral alterations. Preterms fail to receive placental insulin-like growth factor-1 (IGF-1), a major fetal growth hormone in utero, and low IGF-1 serum levels correlate with preterm poor neurodevelopmental outcomes. Here, we mimicked IGF-1 deficiency of preterm newborns in mice by perinatal administration of an IGF-1 receptor antagonist. This resulted in sex-biased brain microstructural, functional, and behavioral alterations, resembling those of ex-preterm children, which we characterized performing parallel mouse/human behavioral tests. Pharmacological enhancement of GABAergic tonic inhibition by the U.S. Food and Drug Administration-approved drug ganaxolone rescued functional/behavioral alterations in mice. Establishing an unprecedented mouse model of prematurity, our work dissects the mechanisms at the core of abnormal behaviors and identifies a readily translatable therapeutic strategy for preterm brain disorders.
Collapse
Affiliation(s)
- Alberto Potenzieri
- Brain Development and Disease Laboratory, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genoa, Italy
- Università degli Studi di Genova, via Balbi, 5, 16126 Genoa, Italy
| | - Sara Uccella
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, 16132 Genoa, Italy
- Child Neuropsychiatry Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy
- Patologia Neonatale, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Deborah Preiti
- Child Neuropsychiatry Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy
- Patologia Neonatale, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Matteo Pisoni
- Optical Approaches to Brain Function Laboratory, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genoa, Italy
| | - Silvia Rosati
- Brain Development and Disease Laboratory, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genoa, Italy
| | - Chiara Lavarello
- Core Facilities - Clinical Proteomics and Metabolomics, IRCCS Istituto Giannina Gaslini, via Gerolamo Gaslini 5, 16147 Genoa, Italy
| | - Martina Bartolucci
- Core Facilities - Clinical Proteomics and Metabolomics, IRCCS Istituto Giannina Gaslini, via Gerolamo Gaslini 5, 16147 Genoa, Italy
| | - Doriana Debellis
- Electron Microscopy Facility, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genoa, Italy
| | - Federico Catalano
- Electron Microscopy Facility, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genoa, Italy
| | - Andrea Petretto
- Core Facilities - Clinical Proteomics and Metabolomics, IRCCS Istituto Giannina Gaslini, via Gerolamo Gaslini 5, 16147 Genoa, Italy
| | - Lino Nobili
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, 16132 Genoa, Italy
- Child Neuropsychiatry Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Tommaso Fellin
- Optical Approaches to Brain Function Laboratory, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genoa, Italy
| | - Valter Tucci
- Genetics and Epigenetics of Behavior (GEB) Laboratory, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genoa, Italy
| | - Luca A. Ramenghi
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, 16132 Genoa, Italy
- Patologia Neonatale, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Annalisa Savardi
- Brain Development and Disease Laboratory, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genoa, Italy
| | - Laura Cancedda
- Brain Development and Disease Laboratory, Istituto Italiano di Tecnologia, via Morego, 30, 16163 Genoa, Italy
| |
Collapse
|
4
|
Vacharasin JM, Ward JA, McCord MM, Cox K, Imitola J, Lizarraga SB. Neuroimmune mechanisms in autism etiology - untangling a complex problem using human cellular models. OXFORD OPEN NEUROSCIENCE 2024; 3:kvae003. [PMID: 38665176 PMCID: PMC11044813 DOI: 10.1093/oons/kvae003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 01/13/2024] [Accepted: 01/31/2024] [Indexed: 04/28/2024]
Abstract
Autism spectrum disorder (ASD) affects 1 in 36 people and is more often diagnosed in males than in females. Core features of ASD are impaired social interactions, repetitive behaviors and deficits in verbal communication. ASD is a highly heterogeneous and heritable disorder, yet its underlying genetic causes account only for up to 80% of the cases. Hence, a subset of ASD cases could be influenced by environmental risk factors. Maternal immune activation (MIA) is a response to inflammation during pregnancy, which can lead to increased inflammatory signals to the fetus. Inflammatory signals can cross the placenta and blood brain barriers affecting fetal brain development. Epidemiological and animal studies suggest that MIA could contribute to ASD etiology. However, human mechanistic studies have been hindered by a lack of experimental systems that could replicate the impact of MIA during fetal development. Therefore, mechanisms altered by inflammation during human pre-natal brain development, and that could underlie ASD pathogenesis have been largely understudied. The advent of human cellular models with induced pluripotent stem cell (iPSC) and organoid technology is closing this gap in knowledge by providing both access to molecular manipulations and culturing capability of tissue that would be otherwise inaccessible. We present an overview of multiple levels of evidence from clinical, epidemiological, and cellular studies that provide a potential link between higher ASD risk and inflammation. More importantly, we discuss how stem cell-derived models may constitute an ideal experimental system to mechanistically interrogate the effect of inflammation during the early stages of brain development.
Collapse
Affiliation(s)
- Janay M Vacharasin
- Department of Biological Sciences, and Center for Childhood Neurotherapeutics, Univ. of South Carolina, 715 Sumter Street, Columbia, SC 29208, USA
- Department of Biological Sciences, Francis Marion University, 4822 East Palmetto Street, Florence, S.C. 29506, USA
| | - Joseph A Ward
- Department of Molecular Biology, Cell Biology, & Biochemistry, Brown University, 185 Meeting Street, Providence, RI 02912, USA
- Center for Translational Neuroscience, Carney Institute of Brain Science, Brown University, 70 Ship Street, Providence, RI 02903, USA
| | - Mikayla M McCord
- Department of Biological Sciences, and Center for Childhood Neurotherapeutics, Univ. of South Carolina, 715 Sumter Street, Columbia, SC 29208, USA
| | - Kaitlin Cox
- Department of Biological Sciences, and Center for Childhood Neurotherapeutics, Univ. of South Carolina, 715 Sumter Street, Columbia, SC 29208, USA
| | - Jaime Imitola
- Laboratory of Neural Stem Cells and Functional Neurogenetics, UConn Health, Departments of Neuroscience, Neurology, Genetics and Genome Sciences, UConn Health, 263 Farmington Avenue, Farmington, CT 06030-5357, USA
| | - Sofia B Lizarraga
- Department of Molecular Biology, Cell Biology, & Biochemistry, Brown University, 185 Meeting Street, Providence, RI 02912, USA
- Center for Translational Neuroscience, Carney Institute of Brain Science, Brown University, 70 Ship Street, Providence, RI 02903, USA
| |
Collapse
|
5
|
Lalonde R, Hernandez M, Strazielle C. BDNF and Cerebellar Ataxia. Curr Drug Res Rev 2024; 16:300-307. [PMID: 37609676 DOI: 10.2174/2589977515666230811093021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 06/06/2023] [Accepted: 06/16/2023] [Indexed: 08/24/2023]
Abstract
Brain-derived neurotrophic factor (BDNF) has been proposed as a treatment for neurodegeneration, including diseases of the cerebellum, where BDNF levels or those of its main receptor, TrkB, are often diminished relative to controls, thereby serving as replacement therapy. Experimental evidence indicates that BDNF signaling countered cerebellar degeneration, sensorimotor deficits, or both, in transgenic ATXN1 mice mutated for ataxin-1, Cacna1a knock-in mice mutated for ataxin-6, mice injected with lentivectors encoding RNA sequences against human FXN into the cerebellar cortex, Kcnj6Wv (Weaver) mutant mice with granule cell degeneration, and rats with olivocerebellar transaction, similar to a BDNF-overexpressing transgenic line interbred with Cacng2stg mutant mice. In this regard, this study discusses whether BDNF is effective in cerebellar pathologies where BDNF levels are normal and whether it is effective in cases with combined cerebellar and basal ganglia damage.
Collapse
Affiliation(s)
- Robert Lalonde
- Université de Lorraine, Laboratoire Stress, Immunité, Pathogènes EA 7300, Campus Santé, 9 avenue de la Forêt de Haye, 54500 Vandoeuvre-les-Nancy, France
| | - Magali Hernandez
- Université de Lorraine, Laboratoire Stress, Immunité, Pathogènes EA 7300, Campus Santé, 9 avenue de la Forêt de Haye, 54500 Vandoeuvre-les-Nancy, France
- CHRU Nancy, allée du Morvan, 54500 Vandoeuvre-les-Nancy, France
| | - Catherine Strazielle
- Université de Lorraine, Laboratoire Stress, Immunité, Pathogènes EA 7300, Campus Santé, 9 avenue de la Forêt de Haye, 54500 Vandoeuvre-les-Nancy, France
- CHRU Nancy, allée du Morvan, 54500 Vandoeuvre-les-Nancy, France
| |
Collapse
|
6
|
Wu Q, Ma L, Joesch-Cohen L, Schmidt M, Uzun EDG, Morrow EM. Targeting NHE6 gene expression identifies lysosome and neurodevelopmental mechanisms in a haploid in vitro cell model. Biol Open 2023; 12:bio059778. [PMID: 37747131 PMCID: PMC10695175 DOI: 10.1242/bio.059778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 09/06/2023] [Indexed: 09/26/2023] Open
Abstract
Christianson syndrome (CS) is an X-linked disorder resulting from loss-of-function (LoF) mutations in SLC9A6 encoding the endosomal Na+/H+ exchanger 6 (NHE6). CS presents with developmental delay, seizures, intellectual disability, nonverbal status, postnatal microcephaly, and ataxia. To define transcriptome signatures of NHE6 LoF, we conducted in-depth RNA-sequencing (RNA-seq) analysis on a haploid NHE6 null cell model. CRIPSR/Cas9 genome editing introduced multiple LoF mutations into SLC9A6 in the near haploid human cell line Hap1. Isogenic, paired parental controls were also studied. NHE6 mutant cell lines were confirmed to have intra-endosomal over-acidification as was seen in other NHE6 null cells. RNA-seq analysis was performed by two widely used pipelines: HISAT2-StringTie-DEseq2 and STAR-HTseq-DEseq2. We identified 1056 differentially expressed genes in mutant NHE6 lines, including genes associated with neurodevelopment, synapse function, voltage-dependent calcium channels, and neuronal signaling. Weighted gene co-expression network analysis was then applied and identified a critical module enriched for genes governing lysosome function. By identifying significantly changed gene expression that is associated with lysosomal mechanisms in NHE6-null cells, our analyses suggest that loss of NHE6 function may converge on mechanisms implicated in lysosome-related neurologic disease. Further, this haploid cell model will serve as an important tool for translational science in CS.
Collapse
Affiliation(s)
- Qing Wu
- Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, RI 02912, USA
- Center for Computational Molecular Biology, Brown University, Center for Computational Molecular Biology, Providence, RI 02912, USA
| | - Li Ma
- Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, RI 02912, USA
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
| | - Lena Joesch-Cohen
- Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, RI 02912, USA
- Center for Computational Molecular Biology, Brown University, Center for Computational Molecular Biology, Providence, RI 02912, USA
| | - Michael Schmidt
- Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, RI 02912, USA
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
| | - Ece D. Gamsiz Uzun
- Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, RI 02912, USA
- Center for Computational Molecular Biology, Brown University, Center for Computational Molecular Biology, Providence, RI 02912, USA
- Department of Pathology and Laboratory Medicine, Alpert Medical School of Brown University, Providence, RI 02912, USA
| | - Eric M. Morrow
- Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, RI 02912, USA
- Center for Computational Molecular Biology, Brown University, Center for Computational Molecular Biology, Providence, RI 02912, USA
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
| |
Collapse
|
7
|
Kavanaugh BC, Elacio J, Best CR, St Pierre DG, Pescosolido MF, Ouyang Q, Caruso P, Buch K, Biedermann J, Bradley RS, Liu JS, Jones RN, Morrow EM. Christianson Syndrome across the Lifespan: An International Longitudinal Study in Children, Adolescents, and Adults. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.11.11.23298218. [PMID: 37987014 PMCID: PMC10659496 DOI: 10.1101/2023.11.11.23298218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Mutations in the X-linked endosomal Na+/H+ Exchanger 6 (NHE6) causes Christianson Syndrome (CS). In the largest study to date, we examine genetic diversity and clinical progression, including cerebellar degeneration, in CS into adulthood. Data were collected as part of the International Christianson Syndrome and NHE6 (SLC9A6) Gene Network Study. Forty-four individuals with 31 unique NHE6 mutations, age 2 to 32 years, were followed prospectively, herein reporting baseline, 1-year follow-up, and retrospective natural history. We present data on the CS phenotype with regard to physical growth, adaptive and motor regression, and across the lifespan, including information on mortality. Longitudinal data on body weight and height were examined using a linear mixed model: the rate of growth across development was slow and resulted in prominently decreased age-normed height and weight by adulthood. Adaptive functioning was longitudinally examined: a majority of adult (18+ years) participants lost gross and fine motor skills over a 1-year follow-up. Previously defined core diagnostic criteria for CS (present in >85%) - namely nonverbal status, intellectual disability, epilepsy, postnatal microcephaly, ataxia, hyperkinesia - were universally present in age 6 to 16; however, an additional core feature of high pain tolerance was added (present in 91%), and furthermore, evolution of symptoms were noted across the lifespan, such that postnatal microcephaly, ataxia and high pain threshold were often not apparent prior to age 6, and hyperkinesis decreased after age 16. While neurologic exams were consistent with cerebellar dysfunction, importantly, a majority of individuals (>50% older than 10) also had corticospinal tract abnormalities. Three participants died during the period of the study. In this large and longitudinal study of CS, we begin to define the trajectory of symptoms and the adult phenotype, thereby identifying critical targets for treatment.
Collapse
|
8
|
Ma L, Kasula RK, Ouyang Q, Schmidt M, Morrow EM. GGA1 interacts with the endosomal Na+/H+ Exchanger NHE6 governing localization to the endosome compartment. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.08.565997. [PMID: 37986849 PMCID: PMC10659387 DOI: 10.1101/2023.11.08.565997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Mutations in the endosomal Na+/H+ exchanger (NHE6) cause Christianson syndrome (CS), an X-linked neurological disorder. Previous studies have shown that NHE6 functions in regulation of endosome acidification and maturation in neurons. Using yeast two-hybrid screening with the NHE6 carboxyl-terminus as bait, we identify Golgi-associated, Gamma adaptin ear containing, ARF binding protein 1 (GGA1) as an interacting partner for NHE6. We corroborated the NHE6-GGA1 interaction using co-immunoprecipitation (co-IP): using over-expressed constructs in mammalian cells; and co-IP of endogenously-expressed GGA1 and NHE6 from neuroblastoma cells, as well as from mouse brain. We demonstrate that GGA1 interacts with organellar NHEs (NHE6, NHE7 and NHE9) but not with cell-surface localized NHEs (NHE1 and NHE5). By constructing hybrid NHE1/NHE6 exchangers, we demonstrate that the cytoplasmic tail of NHE6 is necessary and sufficient for interactions with GGA1. We demonstrate the co-localization of NHE6 and GGA1 in cultured, primary hippocampal neurons, using super-resolution microscopy. We test the hypothesis that the interaction of NHE6 and GGA1 functions in the localization of NHE6 to the endosome compartment. Using subcellular fractionation experiments, we show that NHE6 is mis-localized in GGA1 knockout cells wherein we find less NHE6 in endosomes but more NHE6 transport to lysosomes, and more Golgi retention of NHE6 with increased exocytosis to the surface plasma membrane. Consistent with NHE6 mis-localization, and Golgi retention, we find the intra-luminal pH in Golgi to be alkalinized. Our study demonstrates a new interaction between NHE6 and GGA1 which functions in the localization of this intra-cellular NHE to the endosome compartment.
Collapse
|
9
|
Ghate PS, Vacharasin JM, Ward JA, Nowling D, Kay V, Cowen MH, Lawlor MK, McCord M, Xu H, Carmona E, Cheon SH, Chukwurah E, Walla M, Lizarraga SB. The Warburg micro syndrome protein RAB3GAP1 modulates neuronal morphogenesis and interacts with axon elongation end ER-Golgi trafficking factors. Neurobiol Dis 2023; 184:106215. [PMID: 37385458 DOI: 10.1016/j.nbd.2023.106215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 05/26/2023] [Accepted: 06/26/2023] [Indexed: 07/01/2023] Open
Abstract
RAB3GAP1 is GTPase activating protein localized to the ER and Golgi compartments. In humans, mutations in RAB3GAP1 are the most common cause of Warburg Micro syndrome, a neurodevelopmental disorder associated with intellectual disability, microcephaly, and agenesis of the corpus callosum. We found that downregulation of RAB3GAP1 leads to a reduction in neurite outgrowth and complexity in human stem cell derived neurons. To further define the cellular function of RAB3GAP1, we sought to identify novel interacting proteins. We used a combination of mass spectrometry, co-immunoprecipitation and colocalization analysis and identified two novel interactors of RAB3GAP1: the axon elongation factor Dedicator of cytokinesis 7 (DOCK7) and the TATA modulatory factor 1 (TMF1) a modulator of Endoplasmic Reticulum (ER) to Golgi trafficking. To define the relationship between RAB3GAP1 and its two novel interactors, we analyzed their localization to different subcellular compartments in neuronal and non-neuronal cells with loss of RAB3GAP1. We find that RAB3GAP1 is important for the sub-cellular localization of TMF1 and DOCK7 across different compartments of the Golgi and endoplasmic reticulum. In addition, we find that loss of function mutations in RAB3GAP1 lead to dysregulation of pathways that are activated in response to the cellular stress like ATF6, MAPK, and PI3-AKT signaling. In summary, our findings suggest a novel role for RAB3GAP1 in neurite outgrowth that could encompass the regulation of proteins that control axon elongation, ER-Golgi trafficking, as well as pathways implicated in response to cellular stress.
Collapse
Affiliation(s)
- Pankaj S Ghate
- Department of Biology and Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, United States of America
| | - Janay M Vacharasin
- Department of Biology and Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, United States of America
| | - Joseph A Ward
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, United States of America; Center for Translational Neuroscience, Brown University, Providence, RI, United states of America
| | - Duncan Nowling
- Department of Biology and Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, United States of America
| | - Valerie Kay
- Department of Biology and Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, United States of America
| | - Mara H Cowen
- Department of Biology and Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, United States of America
| | - Mary-Kate Lawlor
- Department of Biology and Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, United States of America
| | - Mikayla McCord
- Department of Biology and Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, United States of America
| | - Hailey Xu
- Department of Biology and Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, United States of America
| | - Esteban Carmona
- Department of Biology and Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, United States of America
| | - Seon-Hye Cheon
- Department of Biology and Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, United States of America
| | - Evelyn Chukwurah
- Department of Biology and Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, United States of America
| | - Mike Walla
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, United States of America
| | - Sofia B Lizarraga
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, United States of America; Center for Translational Neuroscience, Brown University, Providence, RI, United states of America.
| |
Collapse
|
10
|
Leung CS, Rosenzweig SJ, Yoon B, Marinelli NA, Hollingsworth EW, Maguire AM, Cowen MH, Schmidt M, Imitola J, Gamsiz Uzun ED, Lizarraga SB. Dysregulation of the chromatin environment leads to differential alternative splicing as a mechanism of disease in a human model of autism spectrum disorder. Hum Mol Genet 2023; 32:1634-1646. [PMID: 36621967 PMCID: PMC10162432 DOI: 10.1093/hmg/ddad002] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/24/2022] [Accepted: 01/03/2023] [Indexed: 01/10/2023] Open
Abstract
Autism spectrum disorder (ASD) affects 1 in 44 children. Chromatin regulatory proteins are overrepresented among genes that contain high risk variants in ASD. Disruption of the chromatin environment leads to widespread dysregulation of gene expression, which is traditionally thought of as a mechanism of disease pathogenesis associated with ASD. Alternatively, alterations in chromatin dynamics could also lead to dysregulation of alternative splicing, which is understudied as a mechanism of ASD pathogenesis. The anticonvulsant valproic acid (VPA) is a well-known environmental risk factor for ASD that acts as a class I histone deacetylase inhibitor. However, the precise molecular mechanisms underlying defects in human neuronal development associated with exposure to VPA are understudied. To dissect how VPA exposure and subsequent chromatin hyperacetylation influence molecular signatures involved in ASD pathogenesis, we conducted RNA sequencing (RNA-seq) in human cortical neurons that were treated with VPA. We observed that differentially expressed genes (DEGs) were enriched for mRNA splicing, mRNA processing, histone modification and metabolism related gene sets. Furthermore, we observed widespread increases in the number and the type of alternative splicing events. Analysis of differential transcript usage (DTU) showed that exposure to VPA induces extensive alterations in transcript isoform usage across neurodevelopmentally important genes. Finally, we find that DEGs and genes that display DTU overlap with known ASD-risk genes. Altogether, these findings suggest that, in addition to differential gene expression, changes in alternative splicing correlated with alterations in the chromatin environment could act as an additional mechanism of disease in ASD.
Collapse
Affiliation(s)
- Calvin S Leung
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
- Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science (BITS), Brown University, Providence, RI 02912, USA
| | - Shoshana J Rosenzweig
- Center for Computational Molecular Biology, Brown University, Providence, RI 02906, USA
- Department of Pathology and Laboratory Medicine, Warren Alpert Medical School of Brown University, Providence, RI 02912, USA
- Department of Pathology and Laboratory Medicine, Rhode Island Hospital and Lifespan Academic Medical Center, Providence, RI 02903, USA
| | - Brian Yoon
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Nicholas A Marinelli
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Ethan W Hollingsworth
- UCONN Health Comprehensive Multiple Sclerosis Center, Department of Neurology, University of Connecticut School of Medicine, Farmington, CT 06030, USA
- Division of Multiple Sclerosis and Translational Neuroimmunology, Department of Neurology, University of Connecticut School of Medicine, Farmington, CT 06030, USA
| | - Abbie M Maguire
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
- Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science (BITS), Brown University, Providence, RI 02912, USA
| | - Mara H Cowen
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Michael Schmidt
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
- Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science (BITS), Brown University, Providence, RI 02912, USA
| | - Jaime Imitola
- UCONN Health Comprehensive Multiple Sclerosis Center, Department of Neurology, University of Connecticut School of Medicine, Farmington, CT 06030, USA
- Division of Multiple Sclerosis and Translational Neuroimmunology, Department of Neurology, University of Connecticut School of Medicine, Farmington, CT 06030, USA
| | - Ece D Gamsiz Uzun
- Center for Computational Molecular Biology, Brown University, Providence, RI 02906, USA
- Department of Pathology and Laboratory Medicine, Warren Alpert Medical School of Brown University, Providence, RI 02912, USA
- Department of Pathology and Laboratory Medicine, Rhode Island Hospital and Lifespan Academic Medical Center, Providence, RI 02903, USA
| | - Sofia B Lizarraga
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
- Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science (BITS), Brown University, Providence, RI 02912, USA
| |
Collapse
|
11
|
Dong Y, Lian R, Jin L, Zhao S, Tao W, Wang L, Li M, Jia T, Chen X, Cao S. Clinical and genetic analysis of Christianson syndrome caused by variant of SLC9A6: case report and literature review. Front Neurol 2023; 14:1152696. [PMID: 37213903 PMCID: PMC10196350 DOI: 10.3389/fneur.2023.1152696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 04/18/2023] [Indexed: 05/23/2023] Open
Abstract
Background Intellectual disability, X-linked, syndromic, Christianson type (MRXSCH, OMIM: 300243)-known as Christianson syndrome (CS)-is characterized by microcephaly, epilepsy, ataxia, and absence of verbal language ability. CS is attributed to mutations in the solute carrier family 9 member A6 gene (SLC9A6). Materials and methods This study reports the case of a boy 1 year and 3 months of age who was diagnosed with CS in our department. Genetic etiology was determined by whole-exome sequencing, and a minigene splicing assay was used to verify whether the mutation affected splicing. A literature review of CS cases was conducted and the clinical and genetic features were summarized. Results The main clinical manifestations of CS include seizures, developmental regression, and exceptional facial features. Whole-exome sequencing revealed a de novo splice variant in intron 11 (c.1366 + 1G > C) of SLC9A6. The mutation produced two abnormal mRNA products (verified by a minigene splicing assay), resulting in the formation of truncated protein. A total of 95 CS cases were identified in the literature, with various symptoms, such as delayed intellectual development (95/95, 100.00%), epilepsy (87/88, 98.86%), and absent verbal language (75/83, 90.36%). At least 50 pathogenic variants of SLC9A6 have been identified, with the highest frequency observed in exon 12. Conclusion Our patient is the first case with the c.1366 + 1G > C variant of SLC9A6 in CS. The summary of known cases can serve as a reference for analyzing the mutation spectrum and pathogenesis of CS.
Collapse
Affiliation(s)
- Yan Dong
- Department of Pediatrics, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Henan Key Laboratory of Child Brain Injury and Henan Pediatric Clinical Research Center, The Third Affiliated Hospital and Institute of Neuroscience, Zhengzhou, China
- *Correspondence: Yan Dong,
| | - Ruofei Lian
- Department of Pediatrics, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Liang Jin
- Department of Pediatrics, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Shichao Zhao
- Department of Pediatrics, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Wenpeng Tao
- Department of Pediatrics, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Lijun Wang
- Department of Pediatrics, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Mengchun Li
- Department of Pediatrics, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Tianming Jia
- Department of Pediatrics, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Xuejing Chen
- Department of Pediatrics, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Shushi Cao
- Department of Pediatrics, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| |
Collapse
|
12
|
Lee Y, Miller MR, Fernandez MA, Berg EL, Prada AM, Ouyang Q, Schmidt M, Silverman JL, Young-Pearse TL, Morrow EM. Early lysosome defects precede neurodegeneration with amyloid-β and tau aggregation in NHE6-null rat brain. Brain 2022; 145:3187-3202. [PMID: 34928329 PMCID: PMC10147331 DOI: 10.1093/brain/awab467] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 10/25/2021] [Accepted: 11/24/2021] [Indexed: 11/12/2022] Open
Abstract
Loss-of-function mutations in the X-linked endosomal Na+/H+ exchanger 6 (NHE6) cause Christianson syndrome in males. Christianson syndrome involves endosome dysfunction leading to early cerebellar degeneration, as well as later-onset cortical and subcortical neurodegeneration, potentially including tau deposition as reported in post-mortem studies. In addition, there is reported evidence of modulation of amyloid-β levels in experimental models wherein NHE6 expression was targeted. We have recently shown that loss of NHE6 causes defects in endosome maturation and trafficking underlying lysosome deficiency in primary mouse neurons in vitro. For in vivo studies, rat models may have an advantage over mouse models for the study of neurodegeneration, as rat brain can demonstrate robust deposition of endogenously-expressed amyloid-β and tau in certain pathological states. Mouse models generally do not show the accumulation of insoluble, endogenously-expressed (non-transgenic) tau or amyloid-β. Therefore, to study neurodegeneration in Christianson syndrome and the possibility of amyloid-β and tau pathology, we generated an NHE6-null rat model of Christianson syndrome using CRISPR-Cas9 genome-editing. Here, we present the sequence of pathogenic events in neurodegenerating NHE6-null male rat brains across the lifespan. NHE6-null rats demonstrated an early and rapid loss of Purkinje cells in the cerebellum, as well as a more protracted neurodegenerative course in the cerebrum. In both the cerebellum and cerebrum, lysosome deficiency is an early pathogenic event, preceding autophagic dysfunction. Microglial and astrocyte activation also occur early. In the hippocampus and cortex, lysosome defects precede loss of pyramidal cells. Importantly, we subsequently observed biochemical and in situ evidence of both amyloid-β and tau aggregation in the aged NHE6-null hippocampus and cortex (but not in the cerebellum). Tau deposition is widely distributed, including cortical and subcortical distributions. Interestingly, we observed tau deposition in both neurons and glia, as has been reported in Christianson syndrome post-mortem studies previously. In summary, this experimental model is among very few examples of a genetically modified animal that exhibits neurodegeneration with deposition of endogenously-expressed amyloid-β and tau. This NHE6-null rat will serve as a new robust model for Christianson syndrome. Furthermore, these studies provide evidence for linkages between endolysosome dysfunction and neurodegeneration involving protein aggregations, including amyloid-β and tau. Therefore these studies may provide insight into mechanisms of more common neurodegenerative disorders, including Alzheimer's disease and related dementias.
Collapse
Affiliation(s)
- YouJin Lee
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
- Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science (BITS), Brown University, Providence, RI 02912, USA
| | - Morgan R Miller
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
- Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science (BITS), Brown University, Providence, RI 02912, USA
| | - Marty A Fernandez
- Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, USA
| | - Elizabeth L Berg
- MIND Institute and Department of Psychiatry and Behavioural Sciences, University of California Davis School of Medicine, Sacramento, CA, USA
| | - Adriana M Prada
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
- Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science (BITS), Brown University, Providence, RI 02912, USA
| | - Qing Ouyang
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
- Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science (BITS), Brown University, Providence, RI 02912, USA
| | - Michael Schmidt
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
- Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science (BITS), Brown University, Providence, RI 02912, USA
| | - Jill L Silverman
- MIND Institute and Department of Psychiatry and Behavioural Sciences, University of California Davis School of Medicine, Sacramento, CA, USA
| | - Tracy L Young-Pearse
- Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, USA
| | - Eric M Morrow
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
- Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science (BITS), Brown University, Providence, RI 02912, USA
| |
Collapse
|
13
|
Fernandez MA, Bah F, Ma L, Lee Y, Schmidt M, Welch E, Morrow EM, Young-Pearse TL. Loss of endosomal exchanger NHE6 leads to pathological changes in tau in human neurons. Stem Cell Reports 2022; 17:2111-2126. [PMID: 36055242 PMCID: PMC9481919 DOI: 10.1016/j.stemcr.2022.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 08/03/2022] [Accepted: 08/03/2022] [Indexed: 12/09/2022] Open
Abstract
Disruption of endolysosomal and autophagy-lysosomal systems is increasingly implicated in neurodegeneration. Sodium-proton exchanger 6 (NHE6) contributes to the maintenance of proper endosomal pH, and loss-of function mutations in the X-linked NHE6 lead to Christianson syndrome (CS) in males. Neurodegenerative features of CS are increasingly recognized, with postmortem and clinical data implicating a role for tau. We generated cortical neurons from NHE6 knockout (KO) and isogenic wild-type control human induced pluripotent stem cells. We report elevated phosphorylated and sarkosyl-insoluble tau in NHE6 KO neurons. We demonstrate that NHE6 KO leads to lysosomal and autophagy dysfunction involving reduced lysosomal number and protease activity, diminished autophagic flux, and p62 accumulation. Finally, we show that treatment with trehalose or rapamycin, two enhancers of autophagy-lysosomal function, each partially rescue this tau phenotype. We provide insight into the neurodegenerative processes underlying NHE6 loss of function and into the broader role of the endosome-lysosome-autophagy network in neurodegeneration.
Collapse
Affiliation(s)
- Marty A Fernandez
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Fatmata Bah
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Li Ma
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA; Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science (BITS), Brown University, Providence, RI 02912, USA
| | - YouJin Lee
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA; Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science (BITS), Brown University, Providence, RI 02912, USA
| | - Michael Schmidt
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA; Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science (BITS), Brown University, Providence, RI 02912, USA
| | - Elizabeth Welch
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Eric M Morrow
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA; Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science (BITS), Brown University, Providence, RI 02912, USA; Department of Psychiatry and Human Behavior, Warren Alpert Medical School of Brown University, Providence, RI 02912, USA.
| | - Tracy L Young-Pearse
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
| |
Collapse
|
14
|
Farcy S, Albert A, Gressens P, Baffet AD, El Ghouzzi V. Cortical Organoids to Model Microcephaly. Cells 2022; 11:2135. [PMID: 35883578 PMCID: PMC9320662 DOI: 10.3390/cells11142135] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 06/17/2022] [Accepted: 07/05/2022] [Indexed: 02/01/2023] Open
Abstract
How the brain develops and achieves its final size is a fascinating issue that questions cortical evolution across species and man's place in the animal kingdom. Although animal models have so far been highly valuable in understanding the key steps of cortical development, many human specificities call for appropriate models. In particular, microcephaly, a neurodevelopmental disorder that is characterized by a smaller head circumference has been challenging to model in mice, which often do not fully recapitulate the human phenotype. The relatively recent development of brain organoid technology from induced pluripotent stem cells (iPSCs) now makes it possible to model human microcephaly, both due to genetic and environmental origins, and to generate developing cortical tissue from the patients themselves. These 3D tissues rely on iPSCs differentiation into cortical progenitors that self-organize into neuroepithelial rosettes mimicking the earliest stages of human neurogenesis in vitro. Over the last ten years, numerous protocols have been developed to control the identity of the induced brain areas, the reproducibility of the experiments and the longevity of the cultures, allowing analysis of the later stages. In this review, we describe the different approaches that instruct human iPSCs to form cortical organoids, summarize the different microcephalic conditions that have so far been modeled by organoids, and discuss the relevance of this model to decipher the cellular and molecular mechanisms of primary and secondary microcephalies.
Collapse
Affiliation(s)
- Sarah Farcy
- Institut Curie, PSL Research University, CNRS UMR144, F-75005 Paris, France;
| | - Alexandra Albert
- NeuroDiderot, Inserm, Université Paris Cité, F-75019 Paris, France; (A.A.); (P.G.)
| | - Pierre Gressens
- NeuroDiderot, Inserm, Université Paris Cité, F-75019 Paris, France; (A.A.); (P.G.)
| | - Alexandre D. Baffet
- Institut Curie, PSL Research University, CNRS UMR144, F-75005 Paris, France;
| | - Vincent El Ghouzzi
- NeuroDiderot, Inserm, Université Paris Cité, F-75019 Paris, France; (A.A.); (P.G.)
| |
Collapse
|
15
|
Gao AYL, Lourdin-De Filippis E, Orlowski J, McKinney RA. Roles of Endomembrane Alkali Cation/Proton Exchangers in Synaptic Function and Neurodevelopmental Disorders. Front Physiol 2022; 13:892196. [PMID: 35547574 PMCID: PMC9081726 DOI: 10.3389/fphys.2022.892196] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 03/30/2022] [Indexed: 12/25/2022] Open
Abstract
Endomembrane alkali cation (Na+, K+)/proton (H+) exchangers (eNHEs) are increasingly associated with neurological disorders. These eNHEs play integral roles in regulating the luminal pH, processing, and trafficking of cargo along the secretory (Golgi and post-Golgi vesicles) and endocytic (early, recycling, and late endosomes) pathways, essential regulatory processes vital for neuronal development and plasticity. Given the complex morphology and compartmentalization of multipolar neurons, the contribution of eNHEs in maintaining optimal pH homeostasis and cargo trafficking is especially significant during periods of structural and functional development and remodeling. While the importance of eNHEs has been demonstrated in a variety of non-neuronal cell types, their involvement in neuronal function is less well understood. In this review, we will discuss their emerging roles in excitatory synaptic function, particularly as it pertains to cellular learning and remodeling. We will also explore their connections to neurodevelopmental conditions, including intellectual disability, autism, and attention deficit hyperactivity disorders.
Collapse
Affiliation(s)
- Andy Y L Gao
- Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada.,Department of Pharmacology & Therapeutics, McGill University, Montreal, QC, Canada
| | | | - John Orlowski
- Department of Physiology, McGill University, Montreal, QC, Canada
| | - R Anne McKinney
- Department of Pharmacology & Therapeutics, McGill University, Montreal, QC, Canada
| |
Collapse
|
16
|
Ramadesikan S, Lee J, Aguilar RC. The Future of Genetic Disease Studies: Assembling an Updated Multidisciplinary Toolbox. Front Cell Dev Biol 2022; 10:886448. [PMID: 35573700 PMCID: PMC9096115 DOI: 10.3389/fcell.2022.886448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 04/04/2022] [Indexed: 11/20/2022] Open
|
17
|
Cheon S, Culver AM, Bagnell AM, Ritchie FD, Vacharasin JM, McCord MM, Papendorp CM, Chukwurah E, Smith AJ, Cowen MH, Moreland TA, Ghate PS, Davis SW, Liu JS, Lizarraga SB. Counteracting epigenetic mechanisms regulate the structural development of neuronal circuitry in human neurons. Mol Psychiatry 2022; 27:2291-2303. [PMID: 35210569 PMCID: PMC9133078 DOI: 10.1038/s41380-022-01474-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 02/02/2022] [Indexed: 01/23/2023]
Abstract
Autism spectrum disorders (ASD) are associated with defects in neuronal connectivity and are highly heritable. Genetic findings suggest that there is an overrepresentation of chromatin regulatory genes among the genes associated with ASD. ASH1 like histone lysine methyltransferase (ASH1L) was identified as a major risk factor for ASD. ASH1L methylates Histone H3 on Lysine 36, which is proposed to result primarily in transcriptional activation. However, how mutations in ASH1L lead to deficits in neuronal connectivity associated with ASD pathogenesis is not known. We report that ASH1L regulates neuronal morphogenesis by counteracting the catalytic activity of Polycomb Repressive complex 2 group (PRC2) in stem cell-derived human neurons. Depletion of ASH1L decreases neurite outgrowth and decreases expression of the gene encoding the neurotrophin receptor TrkB whose signaling pathway is linked to neuronal morphogenesis. The neuronal morphogenesis defect is overcome by inhibition of PRC2 activity, indicating that a balance between the Trithorax group protein ASH1L and PRC2 activity determines neuronal morphology. Thus, our work suggests that ASH1L may epigenetically regulate neuronal morphogenesis by modulating pathways like the BDNF-TrkB signaling pathway. Defects in neuronal morphogenesis could potentially impair the establishment of neuronal connections which could contribute to the neurodevelopmental pathogenesis associated with ASD in patients with ASH1L mutations.
Collapse
Affiliation(s)
- Seonhye Cheon
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
- Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, USA
| | - Allison M Culver
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
- Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, USA
| | - Anna M Bagnell
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
- Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, USA
| | - Foster D Ritchie
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
- Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, USA
| | - Janay M Vacharasin
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
- Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, USA
| | - Mikayla M McCord
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
- Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, USA
| | - Carin M Papendorp
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, USA
| | - Evelyn Chukwurah
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
- Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, USA
| | - Austin J Smith
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
- Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, USA
| | - Mara H Cowen
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
- Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, USA
| | - Trevor A Moreland
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
- Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, USA
| | - Pankaj S Ghate
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
- Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, USA
| | - Shannon W Davis
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
- Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, USA
| | - Judy S Liu
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, USA
- Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, RI, USA
- Department of Neurology, Rhode Island Hospital and Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Sofia B Lizarraga
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA.
- Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, USA.
| |
Collapse
|
18
|
Liu X, Xie L, Fang Z, Jiang L. Case Report: Novel SLC9A6 Splicing Variant in a Chinese Boy With Christianson Syndrome With Electrical Status Epilepticus During Sleep. Front Neurol 2022; 12:796283. [PMID: 35095740 PMCID: PMC8795361 DOI: 10.3389/fneur.2021.796283] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Accepted: 12/17/2021] [Indexed: 12/30/2022] Open
Abstract
We investigated the existence and potential pathogenicity of a SLC9A6 splicing variant in a Chinese boy with Christianson Syndrome (CS), which was reported for the first time in China. Trio whole-exome sequencing (WES) was performed in the proband and his parents. Multiple computer prediction tools were used to evaluate the pathogenicity of the variant, and reverse transcription-polymerase chain reaction (RT-PCR) analysis and cDNA sequencing were performed to verify the RNA splicing results. The patient presented with characteristic features of CS: global developmental delay, seizures, absent speech, truncal ataxia, microcephaly, ophthalmoplegia, smiling face and hyperkinesis with electrical status epilepticus during sleep (ESES) detected in an electroencephalogram (EEG). A SLC9A6 splicing variant was identified by WES and complete skipping of exon 10 was confirmed by RT-PCR. This resulted in altered gene function and was predicted to be pathogenic. ESES observed early in the disease course is considered to be a significant feature of CS with the SLC9A6 variant. Combined genetic analysis at both the DNA and RNA levels is necessary to confirm the pathogenicity of this variant and its role in the clinical diagnosis of CS.
Collapse
|
19
|
Lan Y, Yi S, Li M, Wang J, Yang Q, Yi S, Chen F, Huang L, Ruan Y, Shen Y, Luo J, Qin Z. Case Report: Christianson Syndrome Caused by SLC9A6 Mutation: From Case to Genotype-Phenotype Analysis. Front Genet 2021; 12:783841. [PMID: 34987551 PMCID: PMC8721738 DOI: 10.3389/fgene.2021.783841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 11/30/2021] [Indexed: 11/13/2022] Open
Abstract
Christianson syndrome (CS) is an X-linked neurodevelopmental syndrome characterized by microcephaly, epilepsy, ataxia, and severe generalized developmental delay. Pathogenic mutations in the SLC9A6 gene, which encodes the Na+/H+ exchanger protein member 6 (NHE6), are associated with CS and autism spectrum disorder in males. In this study, whole exome sequencing (WES) and Sanger sequencing revealed a novel de novo frameshift variant c.1548_1549insT of SLC9A6 in a 14-month-old boy with early-onset seizures. According to The American College of Medical Genetics and Genomics (ACMG)/the Association for Molecular Pathology (AMP) guidelines, the variant was classified as pathogenic. The proband presented with several core symptoms of typical epilepsy, including microcephaly, motor delay, distal muscle weakness, micrognathia, occasional unprovoked laughter, swallowing and speech difficulties. Electroencephalography (EEG) showed spikes-slow waves in frontal pole, frontal, anterior temporal and frontal midline point areas. Gesell development schedules (GDS) indicated generalized developmental delay. We also summarized all the reported variants and analyzed the correlation of genotype and phenotype of CS. Our study extends the mutation spectrum of the SLC9A6 gene, and it might imply that the phenotypes of CS are not correlated with SLC9A6 genotypes.
Collapse
Affiliation(s)
- Yueyun Lan
- Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Guangxi Key Laboratory of Precision Medicine for Genetic Diseases, Guangxi Key Laboratory of Birth Defects and Stem Cell Biobank, Guangxi Key Laboratory of Birth Defects Research and Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Genetic and Metabolic Central Laboratory, Guangxi Birth Defects Research and Prevention Institute, Nanning, China
| | - Sheng Yi
- Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Guangxi Key Laboratory of Precision Medicine for Genetic Diseases, Guangxi Key Laboratory of Birth Defects and Stem Cell Biobank, Guangxi Key Laboratory of Birth Defects Research and Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Genetic and Metabolic Central Laboratory, Guangxi Birth Defects Research and Prevention Institute, Nanning, China
| | - Mengting Li
- Genetic and Metabolic Central Laboratory, Guangxi Birth Defects Research and Prevention Institute, Nanning, China
- The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Jinqiu Wang
- Pediatrics Department, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Qi Yang
- Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Guangxi Key Laboratory of Precision Medicine for Genetic Diseases, Guangxi Key Laboratory of Birth Defects and Stem Cell Biobank, Guangxi Key Laboratory of Birth Defects Research and Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Genetic and Metabolic Central Laboratory, Guangxi Birth Defects Research and Prevention Institute, Nanning, China
| | - Shang Yi
- Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Guangxi Key Laboratory of Precision Medicine for Genetic Diseases, Guangxi Key Laboratory of Birth Defects and Stem Cell Biobank, Guangxi Key Laboratory of Birth Defects Research and Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Genetic and Metabolic Central Laboratory, Guangxi Birth Defects Research and Prevention Institute, Nanning, China
| | - Fei Chen
- Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Guangxi Key Laboratory of Precision Medicine for Genetic Diseases, Guangxi Key Laboratory of Birth Defects and Stem Cell Biobank, Guangxi Key Laboratory of Birth Defects Research and Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Genetic and Metabolic Central Laboratory, Guangxi Birth Defects Research and Prevention Institute, Nanning, China
| | - Limei Huang
- Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Guangxi Key Laboratory of Precision Medicine for Genetic Diseases, Guangxi Key Laboratory of Birth Defects and Stem Cell Biobank, Guangxi Key Laboratory of Birth Defects Research and Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Genetic and Metabolic Central Laboratory, Guangxi Birth Defects Research and Prevention Institute, Nanning, China
| | - Yiyan Ruan
- Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Guangxi Key Laboratory of Precision Medicine for Genetic Diseases, Guangxi Key Laboratory of Birth Defects and Stem Cell Biobank, Guangxi Key Laboratory of Birth Defects Research and Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Yiping Shen
- Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Guangxi Key Laboratory of Precision Medicine for Genetic Diseases, Guangxi Key Laboratory of Birth Defects and Stem Cell Biobank, Guangxi Key Laboratory of Birth Defects Research and Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Genetic and Metabolic Central Laboratory, Guangxi Birth Defects Research and Prevention Institute, Nanning, China
- Department of Genetics, Harvard Medical School, Boston, MA, United States
| | - Jingsi Luo
- Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Guangxi Key Laboratory of Precision Medicine for Genetic Diseases, Guangxi Key Laboratory of Birth Defects and Stem Cell Biobank, Guangxi Key Laboratory of Birth Defects Research and Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Genetic and Metabolic Central Laboratory, Guangxi Birth Defects Research and Prevention Institute, Nanning, China
- *Correspondence: Jingsi Luo, ; Zailong Qin,
| | - Zailong Qin
- Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Guangxi Key Laboratory of Precision Medicine for Genetic Diseases, Guangxi Key Laboratory of Birth Defects and Stem Cell Biobank, Guangxi Key Laboratory of Birth Defects Research and Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Genetic and Metabolic Central Laboratory, Guangxi Birth Defects Research and Prevention Institute, Nanning, China
- *Correspondence: Jingsi Luo, ; Zailong Qin,
| |
Collapse
|
20
|
Ma L, Schmidt M, Morrow EM. Human iPSC lines from a Christianson syndrome patient with NHE6 W523X mutation, a biologically-related control, and CRISPR/Cas9 gene-corrected isogenic controls. Stem Cell Res 2021; 54:102435. [PMID: 34182254 PMCID: PMC8375322 DOI: 10.1016/j.scr.2021.102435] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 06/15/2021] [Indexed: 11/30/2022] Open
Abstract
Loss-of-function mutations in Na+/H + exchanger 6 (NHE6) (also termed SLC9A6) cause the X-linked neurogenetic disorder Christianson syndrome (CS). Using peripheral blood mononuclear cells, we developed induced pluripotent stem cell (iPSC) lines from a patient with the NHE6 nonsense mutation c.1569G > A (p. (W523X)) and diagnosed with CS and from a biologically-related control. Using CRISPR/Cas9 gene editing, we generated two isogenic control lines in which the c.1569G > A mutation was corrected. All lines were verified by DNA sequencing and for NHE6 protein expression, pluripotency, and differentiation potential. These lines will serve as a valuable resource for both basic and translational studies in CS.
Collapse
Affiliation(s)
- Li Ma
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA; Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, RI 02912, USA; Developmental Disorders Genetics Research Program, Department of Psychiatry and Human Behavior, Emma Pendleton Bradley Hospital, East Providence, RI 02915, USA
| | - Michael Schmidt
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA; Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, RI 02912, USA; Developmental Disorders Genetics Research Program, Department of Psychiatry and Human Behavior, Emma Pendleton Bradley Hospital, East Providence, RI 02915, USA
| | - Eric M Morrow
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA; Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, RI 02912, USA; Developmental Disorders Genetics Research Program, Department of Psychiatry and Human Behavior, Emma Pendleton Bradley Hospital, East Providence, RI 02915, USA.
| |
Collapse
|
21
|
Ma L, Prada AM, Schmidt M, Morrow EM. Generation of pathogenic TPP1 mutations in human stem cells as a model for neuronal ceroid lipofuscinosis type 2 disease. Stem Cell Res 2021; 53:102323. [PMID: 33845243 PMCID: PMC9173593 DOI: 10.1016/j.scr.2021.102323] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 03/19/2021] [Accepted: 03/28/2021] [Indexed: 01/22/2023] Open
Abstract
Neuronal ceroid lipofuscinosis type 2 (CLN2 disease) is an autosomal recessive neurodegenerative disorder generally with onset at 2 to 4 years of age and characterized by seizures, loss of vision, progressive motor and mental decline, and premature death. CLN2 disease is caused by loss-of-function mutations in the tripeptidyl peptidase 1 (TPP1) gene leading to deficiency in TPP1 enzyme activity. Approximately 60% of patients have one of two pathogenic variants (c.509–1G > C or c.622C > T [p.(Arg208*)]). In order to generate a human stem cell model of CLN2 disease, we used CRISPR/Cas9-mediated knock-in technology to introduce these mutations in a homozygous state into H9 human embryonic stem cells. Heterozygous lines of the c.622C > T (p.(Arg208*)) mutation were also generated, which included a heterozygous mutant with a wild-type allele and different compound heterozygous coding mutants resulting from indels on one allele. We describe the methodology that led to the generation of the lines and provide data on the initial validation and characterization of these CLN2 disease models. Notably, both mutant lines (c.509–1G > C and c.622C > T [p.(Arg208*)]) in the homozygous state were shown to have reduced or absent protein, respectively, and deficiency of TPP1 enzyme activity. These models, which we have made available for wide-spread sharing, will be useful for future studies of molecular and cellular mechanisms underlying CLN2 disease and for therapeutic development.
Collapse
Affiliation(s)
- Li Ma
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island 02912, USA; Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, Rhode Island 02912, USA
| | - Adriana M Prada
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island 02912, USA; Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, Rhode Island 02912, USA
| | - Michael Schmidt
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island 02912, USA; Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, Rhode Island 02912, USA; Hassenfeld Child Health Innovation Institute, Brown University, Providence, Rhode Island 02912, USA
| | - Eric M Morrow
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island 02912, USA; Center for Translational Neuroscience, Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, Rhode Island 02912, USA; Hassenfeld Child Health Innovation Institute, Brown University, Providence, Rhode Island 02912, USA.
| |
Collapse
|