1
|
Martin P, Szkop KJ, Robert F, Bhattacharyya S, Beauchamp RL, Brenner J, Redmond NE, Huang S, Erdin S, Larsson O, Ramesh V. TSC2 loss in neural progenitor cells suppresses translation of ASD/NDD-associated transcripts in an mTORC1- and MNK1/2-reversible fashion. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.04.597393. [PMID: 38895292 PMCID: PMC11185676 DOI: 10.1101/2024.06.04.597393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Tuberous sclerosis complex (TSC) is an inherited neurodevelopmental disorder (NDD) with frequent manifestations of epilepsy and autism spectrum disorder (ASD). TSC is caused by inactivating mutations in TSC1 or TSC2 tumor suppressor genes, with encoded proteins hamartin (TSC1) and tuberin (TSC2) forming a functional complex inhibiting mechanistic target of rapamycin complex 1 (mTORC1) signaling. This has led to treatment with allosteric mTORC1 inhibitor rapamycin analogs ("rapalogs") for TSC tumors; however, rapalogs are ineffective for treating neurodevelopmental manifestations. mTORC1 signaling controls protein synthesis by regulating formation of the eIF4F complex, with further modulation by MNK1/2 kinases via phosphorylation of the eIF4F subunit eIF4E. While both these pathways modulate translation, comparing their impact on transcriptome-wide mRNA translation, as well as effects of inhibiting these pathways in TSC has not been explored. Here, employing CRISPR-modified, isogenic TSC2 patient-derived neural progenitor cells (NPCs), we have examined transcriptome-wide changes in mRNA translation upon TSC2 loss. Our results reveal dysregulated translation in TSC2 -Null NPCs, which significantly overlaps with the translatome from TSC1 -Null NPCs. Interestingly, numerous non-monogenic ASD-, NDD-and epilepsy-associated genes identified in patients harboring putative loss-of-function mutations, were translationally suppressed in TSC2 -Null NPCs. Importantly, translation of these ASD- and NDD-associated genes was reversed upon inhibition of either mTORC1 or MNK1/2 signaling using RMC-6272 or eFT-508, respectively. This study establishes the importance of mTORC1-eIF4F- and MNK-eIF4E-sensitive mRNA translation in TSC, ASD and other neurodevelopmental disorders laying the groundwork for evaluating drugs in clinical development that target these pathways as a treatment strategy for these disorders.
Collapse
|
2
|
Pazzin DB, Previato TTR, Budelon Gonçalves JI, Zanirati G, Xavier FAC, da Costa JC, Marinowic DR. Induced Pluripotent Stem Cells and Organoids in Advancing Neuropathology Research and Therapies. Cells 2024; 13:745. [PMID: 38727281 PMCID: PMC11083827 DOI: 10.3390/cells13090745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 03/19/2024] [Accepted: 03/19/2024] [Indexed: 05/13/2024] Open
Abstract
This review delves into the groundbreaking impact of induced pluripotent stem cells (iPSCs) and three-dimensional organoid models in propelling forward neuropathology research. With a focus on neurodegenerative diseases, neuromotor disorders, and related conditions, iPSCs provide a platform for personalized disease modeling, holding significant potential for regenerative therapy and drug discovery. The adaptability of iPSCs, along with associated methodologies, enables the generation of various types of neural cell differentiations and their integration into three-dimensional organoid models, effectively replicating complex tissue structures in vitro. Key advancements in organoid and iPSC generation protocols, alongside the careful selection of donor cell types, are emphasized as critical steps in harnessing these technologies to mitigate tumorigenic risks and other hurdles. Encouragingly, iPSCs show promising outcomes in regenerative therapies, as evidenced by their successful application in animal models.
Collapse
Affiliation(s)
- Douglas Bottega Pazzin
- Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul, Porto Alegre 90610-000, Brazil; (D.B.P.); (T.T.R.P.); (J.I.B.G.); (G.Z.); (F.A.C.X.); (J.C.d.C.)
- Graduate Program in Pediatrics and Child Health, School of Medicine, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre 90619-900, Brazil
| | - Thales Thor Ramos Previato
- Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul, Porto Alegre 90610-000, Brazil; (D.B.P.); (T.T.R.P.); (J.I.B.G.); (G.Z.); (F.A.C.X.); (J.C.d.C.)
- Graduate Program in Biomedical Gerontology, School of Medicine, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre 90619-900, Brazil
| | - João Ismael Budelon Gonçalves
- Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul, Porto Alegre 90610-000, Brazil; (D.B.P.); (T.T.R.P.); (J.I.B.G.); (G.Z.); (F.A.C.X.); (J.C.d.C.)
| | - Gabriele Zanirati
- Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul, Porto Alegre 90610-000, Brazil; (D.B.P.); (T.T.R.P.); (J.I.B.G.); (G.Z.); (F.A.C.X.); (J.C.d.C.)
| | - Fernando Antonio Costa Xavier
- Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul, Porto Alegre 90610-000, Brazil; (D.B.P.); (T.T.R.P.); (J.I.B.G.); (G.Z.); (F.A.C.X.); (J.C.d.C.)
| | - Jaderson Costa da Costa
- Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul, Porto Alegre 90610-000, Brazil; (D.B.P.); (T.T.R.P.); (J.I.B.G.); (G.Z.); (F.A.C.X.); (J.C.d.C.)
| | - Daniel Rodrigo Marinowic
- Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul, Porto Alegre 90610-000, Brazil; (D.B.P.); (T.T.R.P.); (J.I.B.G.); (G.Z.); (F.A.C.X.); (J.C.d.C.)
| |
Collapse
|
3
|
Niu W, Siciliano B, Wen Z. Modeling tuberous sclerosis complex with human induced pluripotent stem cells. World J Pediatr 2024; 20:208-218. [PMID: 35759110 DOI: 10.1007/s12519-022-00576-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 05/23/2022] [Indexed: 12/20/2022]
Abstract
BACKGROUND Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder with a birth incidence of 1:6000 in the United States that is characterized by the growth of non-cancerous tumors in multiple organ systems including the brain, kidneys, lungs, and skin. Importantly, TSC is also associated with significant neurological manifestations including epilepsy, TSC-associated neuropsychiatric disorders, intellectual disabilities, and autism spectrum disorder. Mutations in the TSC1 or TSC2 genes are well-established causes of TSC, which lead to TSC1/TSC2 deficiency in organs and hyper-activation of the mammalian target of rapamycin signaling pathway. Animal models have been widely used to study the effect of TSC1/2 genes on the development and function of the brain. Despite considerable progress in understanding the molecular mechanisms underlying TSC in animal models, a human-specific model is urgently needed to investigate the effects of TSC1/2 mutations that are unique to human neurodevelopment. DATA SOURCES Literature reviews and research articles were published in PubMed-indexed journals. RESULTS Human-induced pluripotent stem cells (iPSCs), which capture risk alleles that are identical to their donors and have the capacity to differentiate into virtually any cell type in the human body, pave the way for the empirical study of previously inaccessible biological systems such as the developing human brain. CONCLUSIONS In this review, we present an overview of the recent progress in modeling TSC with human iPSC models, the existing limitations, and potential directions for future research.
Collapse
Affiliation(s)
- Weibo Niu
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Whitehead Research Building 447, 615 Michael Street, Atlanta, GA, 30322, USA
| | - Benjamin Siciliano
- The Graduate Program in Molecular and Systems Pharmacology, Laney Graduate School, Emory University, Atlanta, GA, 30322, USA
| | - Zhexing Wen
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Whitehead Research Building 447, 615 Michael Street, Atlanta, GA, 30322, USA.
- Department of Cell Biology, Emory University School of Medicine, Whitehead Research Building 447, 615 Michael Street, Atlanta, GA, 30322, USA.
- Department of Neurology, Emory University School of Medicine, Whitehead Research Building 447, 615 Michael Street, Atlanta, GA, 30322, USA.
| |
Collapse
|
4
|
Aksoylu IS, Martin P, Robert F, Szkop KJ, Redmond NE, Bhattacharyya S, Wang J, Chen S, Beauchamp RL, Nobeli I, Pelletier J, Larsson O, Ramesh V. Translatome analysis of tuberous sclerosis complex 1 patient-derived neural progenitor cells reveals rapamycin-dependent and independent alterations. Mol Autism 2023; 14:39. [PMID: 37880800 PMCID: PMC10601155 DOI: 10.1186/s13229-023-00572-3] [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: 05/16/2023] [Accepted: 10/13/2023] [Indexed: 10/27/2023] Open
Abstract
BACKGROUND Tuberous sclerosis complex (TSC) is an inherited neurocutaneous disorder caused by mutations in the TSC1 or TSC2 genes, with patients often exhibiting neurodevelopmental (ND) manifestations termed TSC-associated neuropsychiatric disorders (TAND) including autism spectrum disorder (ASD) and intellectual disability. Hamartin (TSC1) and tuberin (TSC2) proteins form a complex inhibiting mechanistic target of rapamycin complex 1 (mTORC1) signaling. Loss of TSC1 or TSC2 activates mTORC1 that, among several targets, controls protein synthesis by inhibiting translational repressor eIF4E-binding proteins. Using TSC1 patient-derived neural progenitor cells (NPCs), we recently reported early ND phenotypic changes, including increased cell proliferation and altered neurite outgrowth in TSC1-null NPCs, which were unaffected by the mTORC1 inhibitor rapamycin. METHODS Here, we used polysome profiling, which quantifies changes in mRNA abundance and translational efficiencies at a transcriptome-wide level, to compare CRISPR-edited TSC1-null with CRISPR-corrected TSC1-WT NPCs generated from one TSC donor (one clone/genotype). To assess the relevance of identified gene expression alterations, we performed polysome profiling in postmortem brains from ASD donors and age-matched controls. We further compared effects on translation of a subset of transcripts and rescue of early ND phenotypes in NPCs following inhibition of mTORC1 using the allosteric inhibitor rapamycin versus a third-generation bi-steric, mTORC1-selective inhibitor RMC-6272. RESULTS Polysome profiling of NPCs revealed numerous TSC1-associated alterations in mRNA translation that were largely recapitulated in human ASD brains. Moreover, although rapamycin treatment partially reversed the TSC1-associated alterations in mRNA translation, most genes related to neural activity/synaptic regulation or ASD were rapamycin-insensitive. In contrast, treatment with RMC-6272 inhibited rapamycin-insensitive translation and reversed TSC1-associated early ND phenotypes including proliferation and neurite outgrowth that were unaffected by rapamycin. CONCLUSIONS Our work reveals ample mRNA translation alterations in TSC1 patient-derived NPCs that recapitulate mRNA translation in ASD brain samples. Further, suppression of TSC1-associated but rapamycin-insensitive translation and ND phenotypes by RMC-6272 unveils potential implications for more efficient targeting of mTORC1 as a superior treatment strategy for TAND.
Collapse
Affiliation(s)
- Inci S Aksoylu
- Department of Oncology-Pathology, Science for Life Laboratory, Karolinska Institute, 171 77, Stockholm, Sweden
| | - Pauline Martin
- Center for Genomic Medicine, Department of Neurology, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA, 02114, USA
| | - Francis Robert
- Department of Biochemistry and Goodman Cancer Research Institute, McGill University, Montreal, PQ, H3G1Y6, Canada
| | - Krzysztof J Szkop
- Department of Oncology-Pathology, Science for Life Laboratory, Karolinska Institute, 171 77, Stockholm, Sweden
| | - Nicholas E Redmond
- Center for Genomic Medicine, Department of Neurology, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA, 02114, USA
| | - Srirupa Bhattacharyya
- Center for Genomic Medicine, Department of Neurology, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA, 02114, USA
| | - Jennifer Wang
- Center for Genomic Medicine, Department of Neurology, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA, 02114, USA
| | - Shan Chen
- Department of Oncology-Pathology, Science for Life Laboratory, Karolinska Institute, 171 77, Stockholm, Sweden
| | - Roberta L Beauchamp
- Center for Genomic Medicine, Department of Neurology, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA, 02114, USA
| | - Irene Nobeli
- Institute of Structural and Molecular Biology, Department of Biological Sciences,, Birkbeck, University of London, London, WC1E 7HX, UK
| | - Jerry Pelletier
- Department of Biochemistry and Goodman Cancer Research Institute, McGill University, Montreal, PQ, H3G1Y6, Canada
| | - Ola Larsson
- Department of Oncology-Pathology, Science for Life Laboratory, Karolinska Institute, 171 77, Stockholm, Sweden.
| | - Vijaya Ramesh
- Center for Genomic Medicine, Department of Neurology, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA, 02114, USA.
| |
Collapse
|
5
|
Meng X, Yao D, Imaizumi K, Chen X, Kelley KW, Reis N, Thete MV, Arjun McKinney A, Kulkarni S, Panagiotakos G, Bassik MC, Pașca SP. Assembloid CRISPR screens reveal impact of disease genes in human neurodevelopment. Nature 2023; 622:359-366. [PMID: 37758944 PMCID: PMC10567561 DOI: 10.1038/s41586-023-06564-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 08/22/2023] [Indexed: 09/29/2023]
Abstract
The assembly of cortical circuits involves the generation and migration of interneurons from the ventral to the dorsal forebrain1-3, which has been challenging to study at inaccessible stages of late gestation and early postnatal human development4. Autism spectrum disorder and other neurodevelopmental disorders (NDDs) have been associated with abnormal cortical interneuron development5, but which of these NDD genes affect interneuron generation and migration, and how they mediate these effects remains unknown. We previously developed a platform to study interneuron development and migration in subpallial organoids and forebrain assembloids6. Here we integrate assembloids with CRISPR screening to investigate the involvement of 425 NDD genes in human interneuron development. The first screen aimed at interneuron generation revealed 13 candidate genes, including CSDE1 and SMAD4. We subsequently conducted an interneuron migration screen in more than 1,000 forebrain assembloids that identified 33 candidate genes, including cytoskeleton-related genes and the endoplasmic reticulum-related gene LNPK. We discovered that, during interneuron migration, the endoplasmic reticulum is displaced along the leading neuronal branch before nuclear translocation. LNPK deletion interfered with this endoplasmic reticulum displacement and resulted in abnormal migration. These results highlight the power of this CRISPR-assembloid platform to systematically map NDD genes onto human development and reveal disease mechanisms.
Collapse
Affiliation(s)
- Xiangling Meng
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
- Stanford Brain Organogenesis Program, Wu Tsai Neurosciences Institute and Bio-X, Stanford, CA, USA
| | - David Yao
- Department of Genetics, Stanford University, Stanford, CA, USA
| | - Kent Imaizumi
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
- Stanford Brain Organogenesis Program, Wu Tsai Neurosciences Institute and Bio-X, Stanford, CA, USA
| | - Xiaoyu Chen
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
- Stanford Brain Organogenesis Program, Wu Tsai Neurosciences Institute and Bio-X, Stanford, CA, USA
| | - Kevin W Kelley
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
- Stanford Brain Organogenesis Program, Wu Tsai Neurosciences Institute and Bio-X, Stanford, CA, USA
| | - Noah Reis
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
- Stanford Brain Organogenesis Program, Wu Tsai Neurosciences Institute and Bio-X, Stanford, CA, USA
| | - Mayuri Vijay Thete
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
- Stanford Brain Organogenesis Program, Wu Tsai Neurosciences Institute and Bio-X, Stanford, CA, USA
| | - Arpana Arjun McKinney
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA, USA
- Departments of Psychiatry and Neuroscience, Black Family Stem Cell Institute, Seaver Autism Center for Research and Treatment, Alper Center for Neural Development and Regeneration, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Shravanti Kulkarni
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
- Stanford Brain Organogenesis Program, Wu Tsai Neurosciences Institute and Bio-X, Stanford, CA, USA
| | - Georgia Panagiotakos
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA, USA
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, USA
- Departments of Psychiatry and Neuroscience, Black Family Stem Cell Institute, Seaver Autism Center for Research and Treatment, Alper Center for Neural Development and Regeneration, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | - Sergiu P Pașca
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA.
- Stanford Brain Organogenesis Program, Wu Tsai Neurosciences Institute and Bio-X, Stanford, CA, USA.
| |
Collapse
|
6
|
Fernandez A, Monsen PJ, Platanias LC, Schiltz GE. Medicinal chemistry approaches to target the MNK-eIF4E axis in cancer. RSC Med Chem 2023; 14:1060-1087. [PMID: 37360400 PMCID: PMC10285747 DOI: 10.1039/d3md00121k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 05/08/2023] [Indexed: 06/28/2023] Open
Abstract
Aberrant translation of proteins that promote cell proliferation is an essential factor that defines oncogenic processes and cancer. The process for ribosomal translation of proteins from mRNA requires an essential initiation step which is controlled by the protein eIF4E, which binds the RNA 5'-cap and forms the eIF4F complex that subsequently translates protein. Typically, eIF4E is activated by phosphorylation on Ser209 by MNK1 and MNK2 kinases. Substantial work has shown that eIF4E and MNK1/2 are dysregulated in many cancers and this axis has therefore become an active area of interest for developing new cancer therapeutics. This review summarizes and discusses recent work to develop small molecules that target different steps in the MNK-eIF4E axis as potential cancer therapeutics. The aim of this review is to cover the breadth of different molecular approaches being taken and the medicinal chemistry basis for their optimization and testing as new cancer therapeutics.
Collapse
Affiliation(s)
- Ann Fernandez
- Department of Chemistry, Northwestern University Evanston IL 60208 USA
| | - Paige J Monsen
- Department of Chemistry, Northwestern University Evanston IL 60208 USA
| | - Leonidas C Platanias
- Robert H. Lurie Comprehensive Cancer Center Chicago IL 60611 USA
- Division of Hematology-Oncology, Department of Medicine, Feinberg School of Medicine, Northwestern University Chicago IL 60611 USA
- Department of Medicine, Jesse Brown Veterans Affairs Medical Center Chicago IL 60612 USA
| | - Gary E Schiltz
- Department of Chemistry, Northwestern University Evanston IL 60208 USA
- Robert H. Lurie Comprehensive Cancer Center Chicago IL 60611 USA
- Department of Pharmacology, Northwestern University Feinberg School of Medicine Chicago IL 60611 USA
| |
Collapse
|
7
|
Attaluri S, Jaimes Gonzalez J, Kirmani M, Vogel AD, Upadhya R, Kodali M, Madhu LN, Rao S, Shuai B, Babu RS, Huard C, Shetty AK. Intranasally administered extracellular vesicles from human induced pluripotent stem cell-derived neural stem cells quickly incorporate into neurons and microglia in 5xFAD mice. Front Aging Neurosci 2023; 15:1200445. [PMID: 37424631 PMCID: PMC10323752 DOI: 10.3389/fnagi.2023.1200445] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 06/07/2023] [Indexed: 07/11/2023] Open
Abstract
Introduction Extracellular vesicles (EVs) released by human-induced pluripotent stem cell (hiPSC)-derived neural stem cells (NSCs) have robust antiinflammatory and neurogenic properties due to therapeutic miRNAs and proteins in their cargo. Hence, hiPSC-NSC-EVs are potentially an excellent biologic for treating neurodegenerative disorders, including Alzheimer's disease (AD). Methods This study investigated whether intranasally (IN) administered hiPSC-NSC-EVs would quickly target various neural cell types in the forebrain, midbrain, and hindbrain regions of 3-month-old 5xFAD mice, a model of β-amyloidosis and familial AD. We administered a single dose of 25 × 109 hiPSC-NSC-EVs labeled with PKH26, and different cohorts of naïve and 5xFAD mice receiving EVs were euthanized at 45 min or 6 h post-administration. Results At 45 min post-administration, EVs were found in virtually all subregions of the forebrain, midbrain, and hindbrain of naïve and 5xFAD mice, with predominant targeting and internalization into neurons, interneurons, and microglia, including plaque-associated microglia in 5xFAD mice. EVs also came in contact with the plasma membranes of astrocytic processes and the soma of oligodendrocytes in white matter regions. Evaluation of CD63/CD81 expression with the neuronal marker confirmed that PKH26 + particles found within neurons were IN administered hiPSC-NSC-EVs. At 6 h post-administration, EVs persisted in all cell types in both groups, with the distribution mostly matching what was observed at 45 min post-administration. Area fraction (AF) analysis revealed that, in both naïve and 5xFAD mice, higher fractions of EVs incorporate into forebrain regions at both time points. However, at 45 min post-IN administration, AFs of EVs within cell layers in forebrain regions and within microglia in midbrain and hindbrain regions were lower in 5xFAD mice than naïve mice, implying that amyloidosis reduces EV penetrance. Discussion Collectively, the results provide novel evidence that IN administration of therapeutic hiPSC-NSC-EVs is an efficient avenue for directing such EVs into neurons and glia in all brain regions in the early stage of amyloidosis. As pathological changes in AD are observed in multiple brain areas, the ability to deliver therapeutic EVs into various neural cells in virtually every brain region in the early stage of amyloidosis is attractive for promoting neuroprotective and antiinflammatory effects.
Collapse
|
8
|
Aksoylu IS, Martin P, Robert F, Szkop KJ, Redmond NE, Chen S, Beauchamp RL, Nobeli I, Pelletier J, Larsson O, Ramesh V. Translatome analysis of Tuberous Sclerosis Complex-1 patient-derived neural progenitor cells reveal rapamycin-dependent and independent alterations. RESEARCH SQUARE 2023:rs.3.rs-2702044. [PMID: 37034588 PMCID: PMC10081384 DOI: 10.21203/rs.3.rs-2702044/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
Tuberous sclerosis complex (TSC) is an inherited neurocutaneous disorder caused by mutations in TSC1 or TSC2 genes, with patients often exhibiting neurodevelopmental (ND) manifestations termed TSC-associated neuropsychiatric disorders (TAND) including autism spectrum disorder (ASD). The hamartin-tuberin (TSC1-TSC2) protein complex inactivates mechanistic target of rapamycin complex 1 (mTORC1) signaling, leading to increased protein synthesis via inactivation of translational repressor eIF4E-binding proteins (4E-BPs). In TSC1-null neural progenitor cells (NPCs), we previously reported early ND phenotypic changes, including increased proliferation/altered neurite outgrowth, which were unaffected by mTORC1-inhibitor rapamycin. Here, using polysome-profiling to quantify translational efficiencies at a transcriptome-wide level, we observed numerous TSC1-dependent alterations in NPCs, largely recapitulated in post-mortem brains from ASD donors. Although rapamycin partially reversed TSC1-associated alterations, most neural activity/synaptic- or ASD-related genes remained insensitive but were inhibited by third-generation bi-steric, mTORC1-selective inhibitor RMC-6272, which also reversed altered ND phenotypes. Together these data reveal potential implications for treatment of TAND.
Collapse
Affiliation(s)
- Inci S. Aksoylu
- Department of Oncology-Pathology, Science for Life Laboratory, Karolinska Institute, Stockholm, Sweden
- These authors contributed equally to this work
| | - Pauline Martin
- Ctr. for Genomic Med., Department of Neurology, Massachusetts Gen. Hosp., Boston, MA
- These authors contributed equally to this work
| | - Francis Robert
- Department of Biochem. and Goodman Cancer Res. Ctr., McGill Univ., Montreal, QC, Canada
- These authors contributed equally to this work
| | - Krzysztof J. Szkop
- Department of Oncology-Pathology, Science for Life Laboratory, Karolinska Institute, Stockholm, Sweden
- These authors contributed equally to this work
| | - Nicholas E. Redmond
- Ctr. for Genomic Med., Department of Neurology, Massachusetts Gen. Hosp., Boston, MA
| | - Shan Chen
- Department of Oncology-Pathology, Science for Life Laboratory, Karolinska Institute, Stockholm, Sweden
| | - Roberta L. Beauchamp
- Ctr. for Genomic Med., Department of Neurology, Massachusetts Gen. Hosp., Boston, MA
| | - Irene Nobeli
- Department of Biol. Sciences, Inst. of Structural and Mol. Biology, Birkbeck, Univ. of London, London, United Kingdom
| | - Jerry Pelletier
- Department of Biochem. and Goodman Cancer Res. Ctr., McGill Univ., Montreal, QC, Canada
| | - Ola Larsson
- Department of Oncology-Pathology, Science for Life Laboratory, Karolinska Institute, Stockholm, Sweden
| | - Vijaya Ramesh
- Ctr. for Genomic Med., Department of Neurology, Massachusetts Gen. Hosp., Boston, MA
| |
Collapse
|
9
|
Thomas SD, Jha NK, Ojha S, Sadek B. mTOR Signaling Disruption and Its Association with the Development of Autism Spectrum Disorder. Molecules 2023; 28:molecules28041889. [PMID: 36838876 PMCID: PMC9964164 DOI: 10.3390/molecules28041889] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 01/31/2023] [Accepted: 02/04/2023] [Indexed: 02/19/2023] Open
Abstract
Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder characterized by impairments in social interaction and communication along with repetitive stereotypic behaviors. Currently, there are no specific biomarkers for diagnostic screening or treatments available for autistic patients. Numerous genetic disorders are associated with high prevalence of ASD, including tuberous sclerosis complex, phosphatase and tensin homolog, and fragile X syndrome. Preclinical investigations in animal models of these diseases have revealed irregularities in the PI3K/Akt/mTOR signaling pathway as well as ASD-related behavioral defects. Reversal of the downstream molecular irregularities, associated with mTOR hyperactivation, improved the behavioral deficits observed in the preclinical investigations. Plant bioactive molecules have shown beneficial pre-clinical evidence in ASD treatment by modulating the PI3K/Akt/mTOR pathway. In this review, we summarize the involvement of the PI3K/Akt/mTOR pathway as well as the genetic alterations of the pathway components and its critical impact on the development of the autism spectrum disorder. Mutations in negative regulators of mTORC1, such as TSC1, TSC2, and PTEN, result in ASD-like phenotypes through the disruption of the mTORC1-mediated signaling. We further discuss the various naturally occurring phytoconstituents that have been identified to be bioactive and modulate the pathway to prevent its disruption and contribute to beneficial therapeutic effects in ASD.
Collapse
Affiliation(s)
- Shilu Deepa Thomas
- Department of Pharmacology and Therapeutics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates
- Zayed Bin Sultan Center for Health Sciences, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates
| | - Niraj Kumar Jha
- Department of Biotechnology, School of Engineering and Technology (SET), Sharda University, Greater Noida 201310, India
- School of Bioengineering & Biosciences, Lovely Professional University, Phagwara 144411, India
- Department of Biotechnology, School of Applied & Life Sciences (SALS), Uttaranchal University, Dehradun 248007, India
| | - Shreesh Ojha
- Department of Pharmacology and Therapeutics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates
- Zayed Bin Sultan Center for Health Sciences, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates
| | - Bassem Sadek
- Department of Pharmacology and Therapeutics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates
- Zayed Bin Sultan Center for Health Sciences, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates
- Correspondence:
| |
Collapse
|
10
|
Transition from Animal-Based to Human Induced Pluripotent Stem Cells (iPSCs)-Based Models of Neurodevelopmental Disorders: Opportunities and Challenges. Cells 2023; 12:cells12040538. [PMID: 36831205 PMCID: PMC9954744 DOI: 10.3390/cells12040538] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 01/25/2023] [Accepted: 02/02/2023] [Indexed: 02/11/2023] Open
Abstract
Neurodevelopmental disorders (NDDs) arise from the disruption of highly coordinated mechanisms underlying brain development, which results in impaired sensory, motor and/or cognitive functions. Although rodent models have offered very relevant insights to the field, the translation of findings to clinics, particularly regarding therapeutic approaches for these diseases, remains challenging. Part of the explanation for this failure may be the genetic differences-some targets not being conserved between species-and, most importantly, the differences in regulation of gene expression. This prompts the use of human-derived models to study NDDS. The generation of human induced pluripotent stem cells (hIPSCs) added a new suitable alternative to overcome species limitations, allowing for the study of human neuronal development while maintaining the genetic background of the donor patient. Several hIPSC models of NDDs already proved their worth by mimicking several pathological phenotypes found in humans. In this review, we highlight the utility of hIPSCs to pave new paths for NDD research and development of new therapeutic tools, summarize the challenges and advances of hIPSC-culture and neuronal differentiation protocols and discuss the best way to take advantage of these models, illustrating this with examples of success for some NDDs.
Collapse
|
11
|
Shimada T, Yamagata K. Spine morphogenesis and synapse formation in tubular sclerosis complex models. Front Mol Neurosci 2022; 15:1019343. [PMID: 36606143 PMCID: PMC9807618 DOI: 10.3389/fnmol.2022.1019343] [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: 08/15/2022] [Accepted: 12/05/2022] [Indexed: 12/24/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is caused by mutations in the Tsc1 or Tsc2 genes, whose products form a complex and inactivate the small G-protein Rheb1. The activation of Rheb1 may cause refractory epilepsy, intellectual disability, and autism, which are the major neuropsychiatric manifestations of TSC. Abnormalities in dendritic spines and altered synaptic structure are hallmarks of epilepsy, intellectual disability, and autism. In addition, spine dysmorphology and aberrant synapse formation are observed in TSC animal models. Therefore, it is important to investigate the molecular mechanism underlying the regulation of spine morphology and synapse formation in neurons to identify therapeutic targets for TSC. In this review, we focus on the representative proteins regulated by Rheb1 activity, mTORC1 and syntenin, which are pivotal downstream factors of Rheb1 in the alteration of spine formation and synapse function in TSC neurons.
Collapse
Affiliation(s)
- Tadayuki Shimada
- Child Brain Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan,*Correspondence: Tadayuki Shimada,
| | - Kanato Yamagata
- Child Brain Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan,Department of Psychiatry, Takada Nishishiro Hospital, Niigata, Japan,Kanato Yamagata,
| |
Collapse
|
12
|
Wang N, Lv L, Huang X, Shi M, Dai Y, Wei Y, Xu B, Fu C, Huang H, Shi H, Liu Y, Hu X, Qin D. Gene editing in monogenic autism spectrum disorder: animal models and gene therapies. Front Mol Neurosci 2022; 15:1043018. [PMID: 36590912 PMCID: PMC9794862 DOI: 10.3389/fnmol.2022.1043018] [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: 09/13/2022] [Accepted: 11/22/2022] [Indexed: 12/15/2022] Open
Abstract
Autism spectrum disorder (ASD) is a lifelong neurodevelopmental disease, and its diagnosis is dependent on behavioral manifestation, such as impaired reciprocal social interactions, stereotyped repetitive behaviors, as well as restricted interests. However, ASD etiology has eluded researchers to date. In the past decades, based on strong genetic evidence including mutations in a single gene, gene editing technology has become an essential tool for exploring the pathogenetic mechanisms of ASD via constructing genetically modified animal models which validates the casual relationship between genetic risk factors and the development of ASD, thus contributing to developing ideal candidates for gene therapies. The present review discusses the progress in gene editing techniques and genetic research, animal models established by gene editing, as well as gene therapies in ASD. Future research should focus on improving the validity of animal models, and reliable DNA diagnostics and accurate prediction of the functional effects of the mutation will likely be equally crucial for the safe application of gene therapies.
Collapse
Affiliation(s)
- Na Wang
- School of Basic Medical Sciences, Yunnan University of Chinese Medicine, Kunming, Yunnan, China
| | - Longbao Lv
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Xiaoyi Huang
- School of Basic Medical Sciences, Yunnan University of Chinese Medicine, Kunming, Yunnan, China
| | - Mingqin Shi
- School of Basic Medical Sciences, Yunnan University of Chinese Medicine, Kunming, Yunnan, China
| | - Youwu Dai
- School of Basic Medical Sciences, Yunnan University of Chinese Medicine, Kunming, Yunnan, China
| | - Yuanyuan Wei
- School of Basic Medical Sciences, Yunnan University of Chinese Medicine, Kunming, Yunnan, China
| | - Bonan Xu
- School of Basic Medical Sciences, Yunnan University of Chinese Medicine, Kunming, Yunnan, China
| | - Chenyang Fu
- School of Basic Medical Sciences, Yunnan University of Chinese Medicine, Kunming, Yunnan, China
| | - Haoyu Huang
- Department of Pediatric Rehabilitation Medicine, Kunming Children’s Hospital, Kunming, Yunnan, China
| | - Hongling Shi
- Department of Rehabilitation Medicine, The Third People’s Hospital of Yunnan Province, Kunming, Yunnan, China
| | - Yun Liu
- Department of Pediatric Rehabilitation Medicine, Kunming Children’s Hospital, Kunming, Yunnan, China,*Correspondence: Dongdong Qin Yun Liu Xintian Hu
| | - Xintian Hu
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China,*Correspondence: Dongdong Qin Yun Liu Xintian Hu
| | - Dongdong Qin
- School of Basic Medical Sciences, Yunnan University of Chinese Medicine, Kunming, Yunnan, China,*Correspondence: Dongdong Qin Yun Liu Xintian Hu
| |
Collapse
|
13
|
FDA-Approved Kinase Inhibitors in Preclinical and Clinical Trials for Neurological Disorders. Pharmaceuticals (Basel) 2022; 15:ph15121546. [PMID: 36558997 PMCID: PMC9784968 DOI: 10.3390/ph15121546] [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: 10/10/2022] [Revised: 12/09/2022] [Accepted: 12/09/2022] [Indexed: 12/14/2022] Open
Abstract
Cancers and neurological disorders are two major types of diseases. We previously developed a new concept termed "Aberrant Cell Cycle Diseases" (ACCD), revealing that these two diseases share a common mechanism of aberrant cell cycle re-entry. The aberrant cell cycle re-entry is manifested as kinase/oncogene activation and tumor suppressor inactivation, which are hallmarks of both tumor growth in cancers and neuronal death in neurological disorders. Therefore, some cancer therapies (e.g., kinase inhibition, tumor suppressor elevation) can be leveraged for neurological treatments. The United States Food and Drug Administration (US FDA) has so far approved 74 kinase inhibitors, with numerous other kinase inhibitors in clinical trials, mostly for the treatment of cancers. In contrast, there are dire unmet needs of FDA-approved drugs for neurological treatments, such as Alzheimer's disease (AD), intracerebral hemorrhage (ICH), ischemic stroke (IS), traumatic brain injury (TBI), and others. In this review, we list these 74 FDA-approved kinase-targeted drugs and identify those that have been reported in preclinical and/or clinical trials for neurological disorders, with a purpose of discussing the feasibility and applicability of leveraging these cancer drugs (FDA-approved kinase inhibitors) for neurological treatments.
Collapse
|
14
|
Human In Vitro Models of Epilepsy Using Embryonic and Induced Pluripotent Stem Cells. Cells 2022; 11:cells11243957. [PMID: 36552721 PMCID: PMC9776452 DOI: 10.3390/cells11243957] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 11/25/2022] [Accepted: 12/04/2022] [Indexed: 12/14/2022] Open
Abstract
The challenges in making animal models of complex human epilepsy phenotypes with varied aetiology highlights the need to develop alternative disease models that can address the limitations of animal models by effectively recapitulating human pathophysiology. The advances in stem cell technology provide an opportunity to use human iPSCs to make disease-in-a-dish models. The focus of this review is to report the current information and progress in the generation of epileptic patient-specific iPSCs lines, isogenic control cell lines, and neuronal models. These in vitro models can be used to study the underlying pathological mechanisms of epilepsies, anti-seizure medication resistance, and can also be used for drug testing and drug screening with their isogenic control cell lines.
Collapse
|
15
|
Damianidou E, Mouratidou L, Kyrousi C. Research models of neurodevelopmental disorders: The right model in the right place. Front Neurosci 2022; 16:1031075. [PMID: 36340790 PMCID: PMC9630472 DOI: 10.3389/fnins.2022.1031075] [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: 08/29/2022] [Accepted: 10/07/2022] [Indexed: 11/25/2022] Open
Abstract
Neurodevelopmental disorders (NDDs) are a heterogeneous group of impairments that affect the development of the central nervous system leading to abnormal brain function. NDDs affect a great percentage of the population worldwide, imposing a high societal and economic burden and thus, interest in this field has widely grown in recent years. Nevertheless, the complexity of human brain development and function as well as the limitations regarding human tissue usage make their modeling challenging. Animal models play a central role in the investigation of the implicated molecular and cellular mechanisms, however many of them display key differences regarding human phenotype and in many cases, they partially or completely fail to recapitulate them. Although in vitro two-dimensional (2D) human-specific models have been highly used to address some of these limitations, they lack crucial features such as complexity and heterogeneity. In this review, we will discuss the advantages, limitations and future applications of in vivo and in vitro models that are used today to model NDDs. Additionally, we will describe the recent development of 3-dimensional brain (3D) organoids which offer a promising approach as human-specific in vitro models to decipher these complex disorders.
Collapse
Affiliation(s)
- Eleni Damianidou
- University Mental Health, Neurosciences and Precision Medicine Research Institute “Costas Stefanis”, Athens, Greece
| | - Lidia Mouratidou
- University Mental Health, Neurosciences and Precision Medicine Research Institute “Costas Stefanis”, Athens, Greece
- First Department of Psychiatry, Medical School, Eginition Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Christina Kyrousi
- University Mental Health, Neurosciences and Precision Medicine Research Institute “Costas Stefanis”, Athens, Greece
- First Department of Psychiatry, Medical School, Eginition Hospital, National and Kapodistrian University of Athens, Athens, Greece
- *Correspondence: Christina Kyrousi,
| |
Collapse
|
16
|
Singla R, Mishra A, Cao R. The trilateral interactions between mammalian target of rapamycin (mTOR) signaling, the circadian clock, and psychiatric disorders: an emerging model. Transl Psychiatry 2022; 12:355. [PMID: 36045116 PMCID: PMC9433414 DOI: 10.1038/s41398-022-02120-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 08/08/2022] [Accepted: 08/12/2022] [Indexed: 02/07/2023] Open
Abstract
Circadian (~24 h) rhythms in physiology and behavior are evolutionarily conserved and found in almost all living organisms. The rhythms are endogenously driven by daily oscillatory activities of so-called "clock genes/proteins", which are widely distributed throughout the mammalian brain. Mammalian (mechanistic) target of rapamycin (mTOR) signaling is a fundamental intracellular signal transduction cascade that controls important neuronal processes including neurodevelopment, synaptic plasticity, metabolism, and aging. Dysregulation of the mTOR pathway is associated with psychiatric disorders including autism spectrum disorders (ASD) and mood disorders (MD), in which patients often exhibit disrupted daily physiological rhythms and abnormal circadian gene expression in the brain. Recent work has found that the activities of mTOR signaling are temporally controlled by the circadian clock and exhibit robust circadian oscillations in multiple systems. In the meantime, mTOR signaling regulates fundamental properties of the central and peripheral circadian clocks, including period length, entrainment, and synchronization. Whereas the underlying mechanisms remain to be fully elucidated, increasing clinical and preclinical evidence support significant crosstalk between mTOR signaling, the circadian clock, and psychiatric disorders. Here, we review recent progress in understanding the trilateral interactions and propose an "interaction triangle" model between mTOR signaling, the circadian clock, and psychiatric disorders (focusing on ASD and MD).
Collapse
Affiliation(s)
- Rubal Singla
- grid.17635.360000000419368657Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN 55812 USA
| | - Abhishek Mishra
- grid.17635.360000000419368657Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN 55812 USA
| | - Ruifeng Cao
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN, 55812, USA. .,Department of Neuroscience, University of Minnesota Medical School, Minneapolis, MN, 55455, USA.
| |
Collapse
|
17
|
Rare CACNA1H and RELN variants interact through mTORC1 pathway in oligogenic autism spectrum disorder. Transl Psychiatry 2022; 12:234. [PMID: 35668055 PMCID: PMC9170683 DOI: 10.1038/s41398-022-01997-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 05/19/2022] [Accepted: 05/25/2022] [Indexed: 11/09/2022] Open
Abstract
Oligogenic inheritance of autism spectrum disorder (ASD) has been supported by several studies. However, little is known about how the risk variants interact and converge on causative neurobiological pathways. We identified in an ASD proband deleterious compound heterozygous missense variants in the Reelin (RELN) gene, and a de novo splicing variant in the Cav3.2 calcium channel (CACNA1H) gene. Here, by using iPSC-derived neural progenitor cells (NPCs) and a heterologous expression system, we show that the variant in Cav3.2 leads to increased calcium influx into cells, which overactivates mTORC1 pathway and, consequently, further exacerbates the impairment of Reelin signaling. Also, we show that Cav3.2/mTORC1 overactivation induces proliferation of NPCs and that both mutant Cav3.2 and Reelin cause abnormal migration of these cells. Finally, analysis of the sequencing data from two ASD cohorts-a Brazilian cohort of 861 samples, 291 with ASD; the MSSNG cohort of 11,181 samples, 5,102 with ASD-revealed that the co-occurrence of risk variants in both alleles of Reelin pathway genes and in one allele of calcium channel genes confer significant liability for ASD. Our results support the notion that genes with co-occurring deleterious variants tend to have interconnected pathways underlying oligogenic forms of ASD.
Collapse
|
18
|
Abstract
[Figure: see text].
Collapse
Affiliation(s)
- Rebecca A Ihrie
- Cell & Developmental Biology and Neurological Surgery, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Elizabeth P Henske
- Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| |
Collapse
|
19
|
Silva MC, Nandi G, Haggarty SJ. Differentiation of Human Induced Pluripotent Stem Cells into Cortical Neurons to Advance Precision Medicine. Methods Mol Biol 2022; 2429:143-174. [PMID: 35507160 DOI: 10.1007/978-1-0716-1979-7_10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
A major obstacle in studying human central nervous system (CNS) diseases is inaccessibility to the affected tissue and cells. Even in limited cases where tissue is available through surgical interventions, differentiated neurons cannot be maintained for extended time frames, which is prohibitive for experimental repetition and scalability. Advances in methodologies for reprogramming human somatic cells into induced pluripotent stem cells (iPSC) and directed differentiation of human neurons in culture now allow access to physiological and disease relevant cell types. In particular, patient iPSC-derived neurons represent unique ex vivo neuronal networks that allow investigating disease genetic and molecular pathways in physiologically accurate cellular microenvironments, importantly recapitulating molecular and cellular phenotypic aspects of disease. Generation of functional neural cells from iPSCs relies on manipulation of culture formats in the presence of specific factors that promote the conversion of pluripotent stem cells into neurons. To this end, several experimental protocols have been developed. Direct differentiation of stem cells into post-mitotic neurons is usually associated with low throughput, low yield, and high technical variability. Instead, methods relying on expansion of the intermediate neural progenitor cells (NPCs) show incredible potential for posterior generation of suitable neuronal cultures for cellular and biochemical assays, as well as drug screening. NPCs are expandable, self-renewable multipotent cells that can differentiate into astrocytes, oligodendrocytes, and electrically active neurons. Here, we describe a protocol for generating iPSC-derived NPCs via formation of neural aggregates and selection of NPC precursor neural rosettes, followed by a simple and reproducible method for generating a mixed population of cortical-like neurons through growth factor withdrawal. Implementation of this protocol has the potential to advance the goals of precision medicine research for both neurological and psychiatric disorders.
Collapse
Affiliation(s)
- M Catarina Silva
- Chemical Neurobiology Laboratory, Center for Genomic Medicine, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
| | - Ghata Nandi
- Chemical Neurobiology Laboratory, Center for Genomic Medicine, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Stephen J Haggarty
- Chemical Neurobiology Laboratory, Center for Genomic Medicine, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
20
|
Girodengo M, Ultanir SK, Bateman JM. Mechanistic target of rapamycin signaling in human nervous system development and disease. Front Mol Neurosci 2022; 15:1005631. [PMID: 36226315 PMCID: PMC9549271 DOI: 10.3389/fnmol.2022.1005631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 09/06/2022] [Indexed: 11/30/2022] Open
Abstract
Mechanistic target of rapamycin (mTOR) is a highly conserved serine/threonine kinase that regulates fundamental cellular processes including growth control, autophagy and metabolism. mTOR has key functions in nervous system development and mis-regulation of mTOR signaling causes aberrant neurodevelopment and neurological diseases, collectively called mTORopathies. In this mini review we discuss recent studies that have deepened our understanding of the key roles of the mTOR pathway in human nervous system development and disease. Recent advances in single-cell transcriptomics have been exploited to reveal specific roles for mTOR signaling in human cortical development that may have contributed to the evolutionary divergence from our primate ancestors. Cerebral organoid technology has been utilized to show that mTOR signaling is active in and regulates outer radial glial cells (RGCs), a population of neural stem cells that distinguish the human developing cortex. mTOR signaling has a well-established role in hamartoma syndromes such as tuberous sclerosis complex (TSC) and other mTORopathies. New ultra-sensitive techniques for identification of somatic mTOR pathway mutations have shed light on the neurodevelopmental origin and phenotypic heterogeneity seen in mTORopathy patients. These emerging studies suggest that mTOR signaling may facilitate developmental processes specific to human cortical development but also, when mis-regulated, cause cortical malformations and neurological disease.
Collapse
Affiliation(s)
- Marie Girodengo
- Kinases and Brain Development Lab, The Francis Crick Institute, London, United Kingdom.,King's College London, Maurice Wohl Clinical Neuroscience Institute, London, United Kingdom
| | - Sila K Ultanir
- Kinases and Brain Development Lab, The Francis Crick Institute, London, United Kingdom
| | - Joseph M Bateman
- King's College London, Maurice Wohl Clinical Neuroscience Institute, London, United Kingdom
| |
Collapse
|
21
|
McTague A, Rossignoli G, Ferrini A, Barral S, Kurian MA. Genome Editing in iPSC-Based Neural Systems: From Disease Models to Future Therapeutic Strategies. Front Genome Ed 2021; 3:630600. [PMID: 34713254 PMCID: PMC8525405 DOI: 10.3389/fgeed.2021.630600] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 02/19/2021] [Indexed: 12/14/2022] Open
Abstract
Therapeutic advances for neurological disorders are challenging due to limited accessibility of the human central nervous system and incomplete understanding of disease mechanisms. Many neurological diseases lack precision treatments, leading to significant disease burden and poor outcome for affected patients. Induced pluripotent stem cell (iPSC) technology provides human neuronal cells that facilitate disease modeling and development of therapies. The use of genome editing, in particular CRISPR-Cas9 technology, has extended the potential of iPSCs, generating new models for a number of disorders, including Alzheimers and Parkinson Disease. Editing of iPSCs, in particular with CRISPR-Cas9, allows generation of isogenic pairs, which differ only in the disease-causing mutation and share the same genetic background, for assessment of phenotypic differences and downstream effects. Moreover, genome-wide CRISPR screens allow high-throughput interrogation for genetic modifiers in neuronal phenotypes, leading to discovery of novel pathways, and identification of new therapeutic targets. CRISPR-Cas9 has now evolved beyond altering gene expression. Indeed, fusion of a defective Cas9 (dCas9) nuclease with transcriptional repressors or activation domains allows down-regulation or activation of gene expression (CRISPR interference, CRISPRi; CRISPR activation, CRISPRa). These new tools will improve disease modeling and facilitate CRISPR and cell-based therapies, as seen for epilepsy and Duchenne muscular dystrophy. Genome engineering holds huge promise for the future understanding and treatment of neurological disorders, but there are numerous barriers to overcome. The synergy of iPSC-based model systems and gene editing will play a vital role in the route to precision medicine and the clinical translation of genome editing-based therapies.
Collapse
Affiliation(s)
- Amy McTague
- Developmental Neurosciences, Great Ormond Street Institute of Child Health, University College London, London, United Kingdom.,Department of Neurology, Great Ormond Street Hospital, London, United Kingdom
| | - Giada Rossignoli
- Developmental Neurosciences, Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Arianna Ferrini
- Developmental Neurosciences, Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Serena Barral
- Developmental Neurosciences, Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Manju A Kurian
- Developmental Neurosciences, Great Ormond Street Institute of Child Health, University College London, London, United Kingdom.,Department of Neurology, Great Ormond Street Hospital, London, United Kingdom
| |
Collapse
|
22
|
Boksha IS, Prokhorova TA, Tereshkina EB, Savushkina OK, Burbaeva GS. Protein Phosphorylation Signaling Cascades in Autism: The Role of mTOR Pathway. BIOCHEMISTRY (MOSCOW) 2021; 86:577-596. [PMID: 33993859 DOI: 10.1134/s0006297921050072] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The mammalian target of rapamycin (mTOR) signaling pathway is a central regulator of cell metabolism, growth, and survival in response to hormones, growth factors, nutrients, and stress-induced signals. In this review, we analyzed the studies on the molecular abnormalities of the mTOR-associated signaling cascades in autism spectrum disorders (ASDs) and outlined the prospects for the pathogenicity-targeting pharmacotherapeutic approaches to ASDs, in particular syndromic ASDs. Based on available experimental and clinical data, we suggest that very early detection of molecular abnormalities in the ASD risk groups can be facilitated by using peripheral blood platelets. Also, identification of the time window of critical dysregulations in the described pathways in the ASD risk groups might suggest further research directions leading to more efficacious pharmacotherapeutic interventions in ASDs.
Collapse
Affiliation(s)
- Irina S Boksha
- Mental Health Research Center, Moscow, 115522, Russia. .,Gamaleya Research Center of Epidemiology and Microbiology, Ministry of Health of the Russian Federation, Moscow, 123098, Russia
| | | | | | | | | |
Collapse
|
23
|
Sharma A, Mehan S. Targeting PI3K-AKT/mTOR signaling in the prevention of autism. Neurochem Int 2021; 147:105067. [PMID: 33992742 DOI: 10.1016/j.neuint.2021.105067] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 04/29/2021] [Accepted: 05/02/2021] [Indexed: 12/16/2022]
Abstract
PI3K-AKT/mTOR signaling pathway represents an essential signaling mechanism for mammalian enzyme-related receptors in transducing signals or biological processes such as cell development, differentiation, cell survival, protein synthesis, and metabolism. Upregulation of the PI3K-AKT/mTOR signaling pathway involves many human brain abnormalities, including autism and other neurological dysfunctions. Autism is a neurodevelopmental disorder associated with behavior and psychiatric illness. This research-based review discusses the functional relationship between the neuropathogenic factors associated with PI3K-AKT/mTOR signaling pathway. Ultimately causes autism-like conditions associated with genetic alterations, neuronal apoptosis, mitochondrial dysfunction, and neuroinflammation. Therefore, inhibition of the PI3K-AKT/mTOR signaling pathway may have an effective therapeutic value for autism treatment. The current review also summarizes the involvement of PI3K-AKT/mTOR signaling pathway inhibitors in the treatment of autism and other neurodegenerative disorders.
Collapse
Affiliation(s)
- Aarti Sharma
- Neuropharmacology Division, Department of Pharmacology, ISF College of Pharmacy, Moga, Punjab, India
| | - Sidharth Mehan
- Neuropharmacology Division, Department of Pharmacology, ISF College of Pharmacy, Moga, Punjab, India.
| |
Collapse
|
24
|
Patient-Derived Induced Pluripotent Stem Cells (iPSCs) and Cerebral Organoids for Drug Screening and Development in Autism Spectrum Disorder: Opportunities and Challenges. Pharmaceutics 2021; 13:pharmaceutics13020280. [PMID: 33669772 PMCID: PMC7922555 DOI: 10.3390/pharmaceutics13020280] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/17/2021] [Accepted: 02/17/2021] [Indexed: 12/23/2022] Open
Abstract
Autism spectrum disorder (ASD) represents a group of neurodevelopmental diseases characterized by persistent deficits in social communication, interaction, and repetitive patterns of behaviors, interests, and activities. The etiopathogenesis is multifactorial with complex interactions between genetic and environmental factors. The clinical heterogeneity and complex etiology of this pediatric disorder have limited the development of pharmacological therapies. The major limit to ASD research remains a lack of relevant human disease models which can faithfully recapitulate key features of the human pathology and represent its genetic heterogeneity. Recent advances in induced pluripotent stem cells (iPSCs), reprogrammed from somatic cells of patients into all types of patient-specific neural cells, have provided a promising cellular tool for disease modeling and development of novel drug treatments. The iPSCs technology allowed not only a better investigation of the disease etiopathogenesis but also opened up the potential for personalized therapies and offered new opportunities for drug discovery, pharmacological screening, and toxicity assessment. Moreover, iPSCs can be differentiated and organized into three-dimensional (3D) organoids, providing a model which mimics the complexity of the brain’s architecture and more accurately recapitulates tissue- and organ-level disease pathophysiology. The aims of this review were to describe the current state of the art of the use of human patient-derived iPSCs and brain organoids in modeling ASD and developing novel therapeutic strategies and to discuss the opportunities and major challenges in this rapidly moving field.
Collapse
|
25
|
Alsaqati M, Heine VM, Harwood AJ. Pharmacological intervention to restore connectivity deficits of neuronal networks derived from ASD patient iPSC with a TSC2 mutation. Mol Autism 2020; 11:80. [PMID: 33076974 PMCID: PMC7574213 DOI: 10.1186/s13229-020-00391-w] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 10/08/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Tuberous sclerosis complex (TSC) is a rare genetic multisystemic disorder resulting from autosomal dominant mutations in the TSC1 or TSC2 genes. It is characterised by hyperactivation of the mechanistic target of rapamycin complex 1 (mTORC1) pathway and has severe neurodevelopmental and neurological components including autism, intellectual disability and epilepsy. In human and rodent models, loss of the TSC proteins causes neuronal hyperexcitability and synaptic dysfunction, although the consequences of these changes for the developing central nervous system are currently unclear. METHODS Here we apply multi-electrode array-based assays to study the effects of TSC2 loss on neuronal network activity using autism spectrum disorder (ASD) patient-derived iPSCs. We examine both temporal synchronisation of neuronal bursting and spatial connectivity between electrodes across the network. RESULTS We find that ASD patient-derived neurons with a functional loss of TSC2, in addition to possessing neuronal hyperactivity, develop a dysfunctional neuronal network with reduced synchronisation of neuronal bursting and lower spatial connectivity. These deficits of network function are associated with elevated expression of genes for inhibitory GABA signalling and glutamate signalling, indicating a potential abnormality of synaptic inhibitory-excitatory signalling. mTORC1 activity functions within a homeostatic triad of protein kinases, mTOR, AMP-dependent protein Kinase 1 (AMPK) and Unc-51 like Autophagy Activating Kinase 1 (ULK1) that orchestrate the interplay of anabolic cell growth and catabolic autophagy while balancing energy and nutrient homeostasis. The mTOR inhibitor rapamycin suppresses neuronal hyperactivity, but does not increase synchronised network activity, whereas activation of AMPK restores some aspects of network activity. In contrast, the ULK1 activator, LYN-1604, increases the network behaviour, shortens the network burst lengths and reduces the number of uncorrelated spikes. LIMITATIONS Although a robust and consistent phenotype is observed across multiple independent iPSC cultures, the results are based on one patient. There may be more subtle differences between patients with different TSC2 mutations or differences of polygenic background within their genomes. This may affect the severity of the network deficit or the pharmacological response between TSC2 patients. CONCLUSIONS Our observations suggest that there is a reduction in the network connectivity of the in vitro neuronal network associated with ASD patients with TSC2 mutation, which may arise via an excitatory/inhibitory imbalance due to increased GABA-signalling at inhibitory synapses. This abnormality can be effectively suppressed via activation of ULK1.
Collapse
Affiliation(s)
- Mouhamed Alsaqati
- Neuroscience and Mental Health Research Institute, Hadyn Ellis Building, Cathays, Cardiff, CF24 4HQ, UK
- Division of Psychological Medicine and Clinical Neurosciences (DPMCN), School of Medicine, Cardiff University, Cardiff, UK
| | - Vivi M Heine
- Department of Complex Trait Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Child and Youth Psychiatry, Emma Children's Hospital, Amsterdam UMC, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Adrian J Harwood
- Neuroscience and Mental Health Research Institute, Hadyn Ellis Building, Cathays, Cardiff, CF24 4HQ, UK.
- School of Bioscience, The Sir Martin Evans Building, Museum Ave, Cardiff, CF10 3AX, UK.
| |
Collapse
|
26
|
Stock R, Jeckel P, Kraushaar U, Wüst R, Fallgatter A, Volkmer H. The potential of induced pluripotent stem cells for discriminating neurodevelopmental disorders. Stem Cells Transl Med 2020; 10:50-56. [PMID: 32864861 PMCID: PMC7780807 DOI: 10.1002/sctm.20-0206] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 07/20/2020] [Accepted: 08/03/2020] [Indexed: 12/14/2022] Open
Abstract
Studying human disease‐specific processes and mechanisms in vitro is limited by a lack of valid human test systems. Induced pluripotent stem cells (iPSCs) evolve as an important and promising tool to better understand the molecular pathology of neurodevelopmental disorders. Patient‐derived iPSCs enable analysis of unique disease mechanisms and may also serve for preclinical drug development. Here, we review the current knowledge on iPSC models for schizophrenia and autism spectrum disorders with emphasis on the discrimination between them. It appears that transcriptomic analyses and functional read‐outs are the most promising approaches to uncover specific disease mechanisms in vitro.
Collapse
Affiliation(s)
- Ricarda Stock
- Department of Molecular Biology, NMI Natural and Medical Sciences Institute at the University of Tübingen, Reutlingen, Germany
| | - Pauline Jeckel
- Department of Molecular Biology, NMI Natural and Medical Sciences Institute at the University of Tübingen, Reutlingen, Germany
| | - Udo Kraushaar
- Department of Molecular Biology, NMI Natural and Medical Sciences Institute at the University of Tübingen, Reutlingen, Germany
| | - Richard Wüst
- Department of Psychiatry, University of Tübingen, Tübingen, Germany
| | | | - Hansjürgen Volkmer
- Department of Molecular Biology, NMI Natural and Medical Sciences Institute at the University of Tübingen, Reutlingen, Germany
| |
Collapse
|
27
|
Hohmann SS, Ilieva M, Michel TM. In vitro models for ASD-patient-derived iPSCs and cerebral organoids. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2020; 173:355-375. [PMID: 32711817 DOI: 10.1016/bs.pmbts.2020.04.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Autism spectrum disorder (ASD) is a set of pervasive neurodevelopmental disorders. The causation is multigenic in most cases, which makes it difficult to model the condition in vitro. Advances in pluripotent stem cell technology has made it possible to generate in vitro models of human brain development. Induced pluripotent stem cells (iPSCs) can be generated from somatic cells and have the ability to differentiate to all of the body's cells. This chapter aims to give an overview of the iPSC technology for generating neural cells and cerebral organoids as models for neurodevelopment and how these models are utilized in the study of ASD. The combination of iPSC technology and the genetic modification tool CRISPR/Cas9 is described, and current limitations and future perspectives of iPSC technology is discussed.
Collapse
Affiliation(s)
- Sonja Simone Hohmann
- Psychiatry in the Region of Southern Denmark, Odense University Hospital, Odense, Denmark.
| | - Mirolyuba Ilieva
- Psychiatry in the Region of Southern Denmark, Odense University Hospital, Odense, Denmark; Department of Psychiatry, Department of Clinical Research, University of Southern Denmark, Odense, Denmark; BRIDGE-Brain Research-Inter-Disciplinary Guided Excellence, Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Tanja Maria Michel
- Psychiatry in the Region of Southern Denmark, Odense University Hospital, Odense, Denmark; Department of Psychiatry, Department of Clinical Research, University of Southern Denmark, Odense, Denmark; BRIDGE-Brain Research-Inter-Disciplinary Guided Excellence, Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| |
Collapse
|
28
|
Goldman A. RAP-ALO(N)G and Make Me Smart. Epilepsy Curr 2020; 20:162-164. [PMID: 32550838 PMCID: PMC7281900 DOI: 10.1177/1535759720919467] [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] [Indexed: 11/30/2022] Open
Abstract
TSC Patient-Derived Isogenic Neural Progenitor Cells Reveal Altered Early
Neurodevelopmental Phenotypes and Rapamycin-Induced MNK-eIF4E Signaling Martin P, Wagh V, Reis SA, et al. Mol Autism. 2020;11:2.
doi:10.1186/s13229-019-0311-3. eCollection 2020. Background: Tuberous sclerosis complex (TSC) is a neurodevelopmental disorder with frequent
occurrence of epilepsy, autism spectrum disorder (ASD), intellectual disability
(ID), and tumors in multiple organs. The aberrant activation of mTORC1 in TSC has
led to treatment with mTORC1 inhibitor rapamycin as a lifelong therapy for tumors,
but TSC-associated neurocognitive manifestations remain unaffected by rapamycin. Methods: Here, we generated patient-specific, induced pluripotent stem cells (iPSCs) from a
patient with TSC with a heterozygous, germline, nonsense mutation in exon 15 of TSC1
and established an isogenic set of heterozygous (Het), null, and corrected wild-type
(Corr-WT) iPSCs using CRISPR/Cas9-mediated gene editing. We differentiated these
iPSCs into neural progenitor cells (NPCs) and examined neurodevelopmental
phenotypes, signaling, and changes in gene expression by RNA-seq. Results: Differentiated NPCs revealed enlarged cell size in TSC1-Het and Null NPCs,
consistent with mTORC1 activation. TSC1-Het and Null NPCs also revealed enhanced
proliferation and altered neurite outgrowth in a genotype-dependent manner, which
was not reversed by rapamycin. Transcriptome analyses of TSC1-NPCs revealed
differentially expressed genes that display a genotype-dependent linear response,
that is, genes upregulated/downregulated in Het were further increased/decreased in
Null. In particular, genes linked to ASD, epilepsy, and ID were significantly
upregulated or downregulated, warranting further investigation. In TSC1-Het and Null
NPCs, we also observed basal activation of ERK1/2, which was further activated upon
rapamycin treatment. Rapamycin also increased MNK1/2-eIF4E signaling in
TSC1-deficient NPCs. Conclusion: MEK-ERK and MNK-eIF4E pathways regulate protein translation, and our results
suggest that aberrant translation distinct in TSC1/2-deficient NPCs could play a
role in neurodevelopmental defects. Our data showing upregulation of these signaling
pathways by rapamycin support a strategy to combine an MEK or an MNK inhibitor with
rapamycin that may be superior for TSC-associated central nervous system defects.
Importantly, our generation of isogenic sets of NPCs from patients with TSC provides
a valuable platform for translatome and large-scale drug screening studies. Overall,
our studies further support the notion that early developmental events such as NPC
proliferation and initial process formation, such as neurite number and length that
occur prior to neuronal differentiation, represent primary events in neurogenesis
critical to disease pathogenesis of neurodevelopmental disorders such as ASD.
Collapse
|