1
|
Traber MG. Deciphering the enigma of the function of alpha-tocopherol as a vitamin. Free Radic Biol Med 2024; 221:64-74. [PMID: 38754744 DOI: 10.1016/j.freeradbiomed.2024.05.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 05/13/2024] [Accepted: 05/14/2024] [Indexed: 05/18/2024]
Abstract
α-Tocopherol (α-T) is a vitamin, but the reasons for the α-T requirement are controversial. Given that α-T deficiency was first identified in embryos, we studied to the premier model of vertebrate embryo development, the zebrafish embryo. We developed an α-T-deficient diet for zebrafish and used fish consuming this diet to produce α-T deficient (E-) embryos. We showed that α-T deficiency causes increased lipid peroxidation, leading to metabolic dysregulation that impacts both biochemical and morphological changes at very early stages in development. These changes occur at an early developmental window, which takes place prior to an analogous time to when a human knows she is pregnant. We found that α-T limits the chain reaction of lipid peroxidation and protects metabolic pathways and integrated gene expression networks that control embryonic development. Importantly, not only is α-T critical during early development, but the neurodevelopmental process is highly dependent on α-T trafficking by the α-T transfer protein (TTPa). Data from both gene expression and evaluation of the metabolome in E- embryos suggest that the activity of the mechanistic Target of Rapamycin (mTOR) signaling pathway is dysregulated-mTOR is a master regulatory mechanism, which controls both metabolism and neurodevelopment. Our findings suggest that TTPa is needed not only for regulation of plasma α-T in adults but is a key regulator during embryogenesis.
Collapse
Affiliation(s)
- Maret G Traber
- Linus Pauling Institute, Oregon State University, Corvallis, 97330, OR, USA.
| |
Collapse
|
2
|
Chalkley MBL, Guerin LN, Iyer T, Mallahan S, Nelson S, Sahin M, Hodges E, Ess KC, Ihrie RA. Human TSC2 Mutant Cells Exhibit Aberrations in Early Neurodevelopment Accompanied by Changes in the DNA Methylome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.04.597443. [PMID: 38895266 PMCID: PMC11185654 DOI: 10.1101/2024.06.04.597443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Tuberous Sclerosis Complex (TSC) is a debilitating developmental disorder characterized by a variety of clinical manifestations. While benign tumors in the heart, lungs, kidney, and brain are all hallmarks of the disease, the most severe symptoms of TSC are often neurological, including seizures, autism, psychiatric disorders, and intellectual disabilities. TSC is caused by loss of function mutations in the TSC1 or TSC2 genes and consequent dysregulation of signaling via mechanistic Target of Rapamycin Complex 1 (mTORC1). While TSC neurological phenotypes are well-documented, it is not yet known how early in neural development TSC1/2-mutant cells diverge from the typical developmental trajectory. Another outstanding question is the contribution of homozygous-mutant cells to disease phenotypes and whether such phenotypes are also seen in the heterozygous-mutant populations that comprise the vast majority of cells in patients. Using TSC patient-derived isogenic induced pluripotent stem cells (iPSCs) with defined genetic changes, we observed aberrant early neurodevelopment in vitro, including misexpression of key proteins associated with lineage commitment and premature electrical activity. These alterations in differentiation were coincident with hundreds of differentially methylated DNA regions, including loci associated with key genes in neurodevelopment. Collectively, these data suggest that mutation or loss of TSC2 affects gene regulation and expression at earlier timepoints than previously appreciated, with implications for whether and how prenatal treatment should be pursued.
Collapse
Affiliation(s)
- Mary-Bronwen L. Chalkley
- Department of Cell & Developmental Biology, School of Medicine Basic Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Lindsey N. Guerin
- Department of Biochemistry, School of Medicine Basic Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Tenhir Iyer
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Samantha Mallahan
- Department of Cell & Developmental Biology, School of Medicine Basic Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Sydney Nelson
- Department of Cell & Developmental Biology, School of Medicine Basic Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Mustafa Sahin
- Rosamund Stone Zander Translational Neuroscience Center, Department of Neurology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Emily Hodges
- Department of Biochemistry, School of Medicine Basic Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Kevin C. Ess
- Department of Cell & Developmental Biology, School of Medicine Basic Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Denver, Colorado, United States of America
| | - Rebecca A. Ihrie
- Department of Cell & Developmental Biology, School of Medicine Basic Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| |
Collapse
|
3
|
Ribierre T, Bacq A, Donneger F, Doladilhe M, Maletic M, Roussel D, Le Roux I, Chassoux F, Devaux B, Adle-Biassette H, Ferrand-Sorbets S, Dorfmüller G, Chipaux M, Baldassari S, Poncer JC, Baulac S. Targeting pathological cells with senolytic drugs reduces seizures in neurodevelopmental mTOR-related epilepsy. Nat Neurosci 2024; 27:1125-1136. [PMID: 38710875 PMCID: PMC11156583 DOI: 10.1038/s41593-024-01634-2] [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: 10/17/2022] [Accepted: 03/28/2024] [Indexed: 05/08/2024]
Abstract
Cortical malformations such as focal cortical dysplasia type II (FCDII) are associated with pediatric drug-resistant epilepsy that necessitates neurosurgery. FCDII results from somatic mosaicism due to post-zygotic mutations in genes of the PI3K-AKT-mTOR pathway, which produce a subset of dysmorphic cells clustered within healthy brain tissue. Here we show a correlation between epileptiform activity in acute cortical slices obtained from human surgical FCDII brain tissues and the density of dysmorphic neurons. We uncovered multiple signatures of cellular senescence in these pathological cells, including p53/p16 expression, SASP expression and senescence-associated β-galactosidase activity. We also show that administration of senolytic drugs (dasatinib/quercetin) decreases the load of senescent cells and reduces seizure frequency in an MtorS2215F FCDII preclinical mouse model, providing proof of concept that senotherapy may be a useful approach to control seizures. These findings pave the way for therapeutic strategies selectively targeting mutated senescent cells in FCDII brain tissue.
Collapse
Affiliation(s)
- Théo Ribierre
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié Salpêtrière, Paris, France
- Department of Basic Neurosciences, University of Geneva, Geneva, Switzerland
- NeuroNA Human Cellular Neuroscience Platform, Fondation Campus Biotech Geneva, Geneva, Switzerland
| | - Alexandre Bacq
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié Salpêtrière, Paris, France
| | - Florian Donneger
- Institut du Fer à Moulin, INSERM, Sorbonne Université, UMR-S 1270, Paris, France
| | - Marion Doladilhe
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié Salpêtrière, Paris, France
| | - Marina Maletic
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié Salpêtrière, Paris, France
| | - Delphine Roussel
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié Salpêtrière, Paris, France
| | - Isabelle Le Roux
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié Salpêtrière, Paris, France
| | - Francine Chassoux
- Service de Neurochirurgie, AP-HP, Hôpital Lariboisière, Paris, France
- GHU Paris, Psychiatrie et Neurosciences, Paris, France
| | - Bertrand Devaux
- Service de Neurochirurgie, AP-HP, Hôpital Lariboisière, Paris, France
- GHU Paris, Psychiatrie et Neurosciences, Paris, France
| | - Homa Adle-Biassette
- Université de Paris Cité, Service d'Anatomie Pathologique, AP-HP, Hôpital Lariboisière, DMU DREAM, UMR 1141, INSERM, Paris, France
| | | | - Georg Dorfmüller
- Department of Pediatric Neurosurgery, Rothschild Foundation Hospital, Paris, France
| | - Mathilde Chipaux
- Department of Pediatric Neurosurgery, Rothschild Foundation Hospital, Paris, France
| | - Sara Baldassari
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié Salpêtrière, Paris, France
| | | | - Stéphanie Baulac
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié Salpêtrière, Paris, France.
| |
Collapse
|
4
|
Benedetti MC, D'andrea T, Colantoni A, Silachev D, de Turris V, Boussadia Z, Babenko VA, Volovikov EA, Belikova L, Bogomazova AN, Pepponi R, Whye D, Buttermore ED, Tartaglia GG, Lagarkova MA, Katanaev VL, Musayev I, Martinelli S, Fucile S, Rosa A. Cortical neurons obtained from patient-derived iPSCs with GNAO1 p.G203R variant show altered differentiation and functional properties. Heliyon 2024; 10:e26656. [PMID: 38434323 PMCID: PMC10907651 DOI: 10.1016/j.heliyon.2024.e26656] [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: 08/03/2023] [Revised: 01/24/2024] [Accepted: 02/16/2024] [Indexed: 03/05/2024] Open
Abstract
Pathogenic variants in the GNAO1 gene, encoding the alpha subunit of an inhibitory heterotrimeric guanine nucleotide-binding protein (Go) highly expressed in the mammalian brain, have been linked to encephalopathy characterized by different combinations of neurological symptoms, including developmental delay, hypotonia, epilepsy and hyperkinetic movement disorder with life-threatening paroxysmal exacerbations. Currently, there are only symptomatic treatments, and little is known about the pathophysiology of GNAO1-related disorders. Here, we report the characterization of a new in vitro model system based on patient-derived induced pluripotent stem cells (hiPSCs) carrying the recurrent p.G203R amino acid substitution in Gαo, and a CRISPR-Cas9-genetically corrected isogenic control line. RNA-Seq analysis highlighted aberrant cell fate commitment in neuronal progenitor cells carrying the p.G203R pathogenic variant. Upon differentiation into cortical neurons, patients' cells showed reduced expression of early neural genes and increased expression of astrocyte markers, as well as premature and defective differentiation processes leading to aberrant formation of neuronal rosettes. Of note, comparable defects in gene expression and in the morphology of neural rosettes were observed in hiPSCs from an unrelated individual harboring the same GNAO1 variant. Functional characterization showed lower basal intracellular free calcium concentration ([Ca2+]i), reduced frequency of spontaneous activity, and a smaller response to several neurotransmitters in 40- and 50-days differentiated p.G203R neurons compared to control cells. These findings suggest that the GNAO1 pathogenic variant causes a neurodevelopmental phenotype characterized by aberrant differentiation of both neuronal and glial populations leading to a significant alteration of neuronal communication and signal transduction.
Collapse
Affiliation(s)
- Maria Cristina Benedetti
- Department of Biology and Biotechnologies “Charles Darwin”, Sapienza University of Rome, Rome, Italy
- Center for Life Nano- & Neuro-Science, Fondazione Istituto Italiano di Tecnologia (IIT), Rome, Italy
| | - Tiziano D'andrea
- Department of Physiology and Pharmacology “V. Erspamer”, Sapienza University of Rome, Rome, Italy
| | - Alessio Colantoni
- Department of Biology and Biotechnologies “Charles Darwin”, Sapienza University of Rome, Rome, Italy
- Center for Life Nano- & Neuro-Science, Fondazione Istituto Italiano di Tecnologia (IIT), Rome, Italy
| | - Denis Silachev
- School of Medicine and Life Sciences, Far Eastern Federal University, 690090, Vladivostok, Russia
- A.N. Belozersky Research Institute of Physico-Chemical Biology, Moscow State University, 119992, Moscow, Russia
- Department of Cell Physiology and Metabolism, Faculty of Medicine, Translational Research Center in Oncohaematology, University of Geneva, 1211, Geneva, Switzerland
| | - Valeria de Turris
- Center for Life Nano- & Neuro-Science, Fondazione Istituto Italiano di Tecnologia (IIT), Rome, Italy
| | - Zaira Boussadia
- National Center for Drug Research and Evaluation, Istituto Superiore di Sanità, Rome, Italy
| | - Valentina A. Babenko
- A.N. Belozersky Research Institute of Physico-Chemical Biology, Moscow State University, 119992, Moscow, Russia
- Department of Cell Physiology and Metabolism, Faculty of Medicine, Translational Research Center in Oncohaematology, University of Geneva, 1211, Geneva, Switzerland
| | - Egor A. Volovikov
- Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 119435, Moscow, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 119435, Moscow, Russia
| | - Lilia Belikova
- Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 119435, Moscow, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 119435, Moscow, Russia
| | - Alexandra N. Bogomazova
- Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 119435, Moscow, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 119435, Moscow, Russia
| | - Rita Pepponi
- National Center for Drug Research and Evaluation, Istituto Superiore di Sanità, Rome, Italy
| | - Dosh Whye
- Human Neuron Core, Rosamund Stone Zander Translational Neuroscience Center and F.M. Kirby Neurobiology Department, Boston Children's Hospital, Boston, MA, USA
| | - Elizabeth D. Buttermore
- Human Neuron Core, Rosamund Stone Zander Translational Neuroscience Center and F.M. Kirby Neurobiology Department, Boston Children's Hospital, Boston, MA, USA
| | - Gian Gaetano Tartaglia
- Center for Human Technologies (CHT), Istituto Italiano di Tecnologia (IIT), Genova, Italy
| | - Maria A. Lagarkova
- Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 119435, Moscow, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 119435, Moscow, Russia
| | - Vladimir L. Katanaev
- School of Medicine and Life Sciences, Far Eastern Federal University, 690090, Vladivostok, Russia
- Department of Cell Physiology and Metabolism, Faculty of Medicine, Translational Research Center in Oncohaematology, University of Geneva, 1211, Geneva, Switzerland
| | | | - Simone Martinelli
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Sergio Fucile
- Department of Physiology and Pharmacology “V. Erspamer”, Sapienza University of Rome, Rome, Italy
- IRCCS Neuromed, Pozzilli, Italy
| | - Alessandro Rosa
- Department of Biology and Biotechnologies “Charles Darwin”, Sapienza University of Rome, Rome, Italy
- Center for Life Nano- & Neuro-Science, Fondazione Istituto Italiano di Tecnologia (IIT), Rome, Italy
| |
Collapse
|
5
|
Garone C, De Giorgio F, Carli S. Mitochondrial metabolism in neural stem cells and implications for neurodevelopmental and neurodegenerative diseases. J Transl Med 2024; 22:238. [PMID: 38438847 PMCID: PMC10910780 DOI: 10.1186/s12967-024-05041-w] [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: 12/29/2023] [Accepted: 02/25/2024] [Indexed: 03/06/2024] Open
Abstract
Mitochondria are cytoplasmic organelles having a fundamental role in the regulation of neural stem cell (NSC) fate during neural development and maintenance.During embryonic and adult neurogenesis, NSCs undergo a metabolic switch from glycolytic to oxidative phosphorylation with a rise in mitochondrial DNA (mtDNA) content, changes in mitochondria shape and size, and a physiological augmentation of mitochondrial reactive oxygen species which together drive NSCs to proliferate and differentiate. Genetic and epigenetic modifications of proteins involved in cellular differentiation (Mechanistic Target of Rapamycin), proliferation (Wingless-type), and hypoxia (Mitogen-activated protein kinase)-and all connected by the common key regulatory factor Hypoxia Inducible Factor-1A-are deemed to be responsible for the metabolic shift and, consequently, NSC fate in physiological and pathological conditions.Both primary mitochondrial dysfunction due to mutations in nuclear DNA or mtDNA or secondary mitochondrial dysfunction in oxidative phosphorylation (OXPHOS) metabolism, mitochondrial dynamics, and organelle interplay pathways can contribute to the development of neurodevelopmental or progressive neurodegenerative disorders.This review analyses the physiology and pathology of neural development starting from the available in vitro and in vivo models and highlights the current knowledge concerning key mitochondrial pathways involved in this process.
Collapse
Affiliation(s)
- C Garone
- Department of Medical and Surgical Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy.
- IRCCS Istituto Delle Scienze Neurologiche di Bologna, UO Neuropsichiatria Dell'età Pediatrica, Bologna, Italy.
| | - F De Giorgio
- Department of Medical and Surgical Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - S Carli
- Department of Medical and Surgical Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy
| |
Collapse
|
6
|
McArdle CJ, Arnone AA, Heaney CF, Raab-Graham KF. A paradoxical switch: the implications of excitatory GABAergic signaling in neurological disorders. Front Psychiatry 2024; 14:1296527. [PMID: 38268565 PMCID: PMC10805837 DOI: 10.3389/fpsyt.2023.1296527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 12/04/2023] [Indexed: 01/26/2024] Open
Abstract
Gamma-aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the central nervous system. In the mature brain, inhibitory GABAergic signaling is critical in maintaining neuronal homeostasis and vital human behaviors such as cognition, emotion, and motivation. While classically known to inhibit neuronal function under physiological conditions, previous research indicates a paradoxical switch from inhibitory to excitatory GABAergic signaling that is implicated in several neurological disorders. Various mechanisms have been proposed to contribute to the excitatory switch such as chloride ion dyshomeostasis, alterations in inhibitory receptor expression, and modifications in GABAergic synaptic plasticity. Of note, the hypothesized mechanisms underlying excitatory GABAergic signaling are highlighted in a number of neurodevelopmental, substance use, stress, and neurodegenerative disorders. Herein, we present an updated review discussing the presence of excitatory GABAergic signaling in various neurological disorders, and their potential contributions towards disease pathology.
Collapse
Affiliation(s)
- Colin J. McArdle
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - Alana A. Arnone
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC, United States
- Department of General Surgery, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - Chelcie F. Heaney
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - Kimberly F. Raab-Graham
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| |
Collapse
|
7
|
Cobourn KD, Chesney KM, Mueller K, Fayed I, Tsering D, Keating RF. Isolated subependymal giant cell astrocytoma (SEGA) in the absence of clinical tuberous sclerosis: two case reports and literature review. Childs Nerv Syst 2024; 40:73-78. [PMID: 37658938 DOI: 10.1007/s00381-023-06105-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 07/25/2023] [Indexed: 09/05/2023]
Abstract
PURPOSE Subependymal giant cell astrocytoma (SEGA) is a WHO grade I pediatric glioma arising in 5-15% of patients with tuberous sclerosis (TSC). Rare cases of isolated SEGA without TSC have been described. The etiology, genetic mechanisms, natural history, and response to treatment of these lesions are currently unknown. We describe two such cases of isolated SEGA with follow-up. METHODS Retrospective review was performed at a single institution to describe the clinical course of pathology-confirmed SEGA in patients with germline testing negative for TSC mutations. RESULTS Two cases of isolated SEGA were identified. Genetic analysis of the tumor specimen was available for one, which revealed an 18 base pair deletion in TSC1. Both cases were managed with surgical resection, one with preoperative embolization. In spite of a gross total resection, one patient experienced recurrence after three years. Treatment with an mTOR inhibitor led to a significant interval reduction of the mass on follow-up MRI. The patient tolerated the medication well for 6 years and is now off of treatment for 2 years with a stable lesion. CONCLUSION Cases of SEGA outside of the context of TSC are exceedingly rare, with only 48 cases previously described. The genetic mechanisms and treatment response of these lesions are poorly understood. To date, these lesions appear to respond well to mTOR inhibitors and may behave similarly to SEGAs associated with TSC. However, given that experience is extremely limited, these cases should be followed long term to better understand their natural history and treatment response.
Collapse
Affiliation(s)
- Kelsey D Cobourn
- Department of Neurosurgery, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC, USA
| | - Kelsi M Chesney
- Department of Neurosurgery, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC, USA
| | - Kyle Mueller
- Department of Neurosurgery, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC, USA
| | - Islam Fayed
- Department of Neurosurgery, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC, USA
| | - Deki Tsering
- Department of Neurosurgery, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC, USA
| | - Robert F Keating
- Department of Neurosurgery, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC, USA.
| |
Collapse
|
8
|
Riley VA, Shankar V, Holmberg JC, Sokolov AM, Neckles VN, Williams K, Lyman R, Mackay TF, Feliciano DM. Tsc2 coordinates neuroprogenitor differentiation. iScience 2023; 26:108442. [PMID: 38107199 PMCID: PMC10724693 DOI: 10.1016/j.isci.2023.108442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 09/22/2023] [Accepted: 11/09/2023] [Indexed: 12/19/2023] Open
Abstract
Neural stem cells (NSCs) of the ventricular-subventricular zone (V-SVZ) generate numerous cell types. The uncoupling of mRNA transcript availability and translation occurs during the progression from stem to differentiated states. The mTORC1 kinase pathway acutely controls proteins that regulate mRNA translation. Inhibiting mTORC1 during differentiation is hypothesized to be critical for brain development since somatic mutations of mTORC1 regulators perturb brain architecture. Inactivating mutations of TSC1 or TSC2 genes cause tuberous sclerosis complex (TSC). TSC patients have growths near the striatum and ventricles. Here, it is demonstrated that V-SVZ NSC Tsc2 inactivation causes striatal hamartomas. Tsc2 removal altered translation factors, translatomes, and translational efficiency. Single nuclei RNA sequencing following in vivo loss of Tsc2 revealed changes in NSC activation states. The inability to decouple mRNA transcript availability and translation delayed differentiation leading to the retention of immature phenotypes in hamartomas. Taken together, Tsc2 is required for translational repression and differentiation.
Collapse
Affiliation(s)
- Victoria A. Riley
- Department of Biological Sciences, Clemson University, Clemson, SC, USA
| | - Vijay Shankar
- Department of Biochemistry and Genetics, Clemson University, Clemson, SC, USA
- Center for Human Genetics, Clemson University, Greenwood, SC, USA
| | | | - Aidan M. Sokolov
- Department of Biological Sciences, Clemson University, Clemson, SC, USA
| | | | - Kaitlyn Williams
- Clemson University Genomics and Bioinformatics Facility (CUGBF), Clemson University, Clemson, SC, USA
| | - Rachel Lyman
- Department of Biochemistry and Genetics, Clemson University, Clemson, SC, USA
- Center for Human Genetics, Clemson University, Greenwood, SC, USA
| | - Trudy F.C. Mackay
- Department of Biochemistry and Genetics, Clemson University, Clemson, SC, USA
- Center for Human Genetics, Clemson University, Greenwood, SC, USA
| | - David M. Feliciano
- Department of Biological Sciences, Clemson University, Clemson, SC, USA
- Center for Human Genetics, Clemson University, Greenwood, SC, USA
| |
Collapse
|
9
|
Okoh J, Mays J, Bacq A, Oses-Prieto JA, Tyanova S, Chen CJ, Imanbeyev K, Doladilhe M, Zhou H, Jafar-Nejad P, Burlingame A, Noebels J, Baulac S, Costa-Mattioli M. Targeted suppression of mTORC2 reduces seizures across models of epilepsy. Nat Commun 2023; 14:7364. [PMID: 37963879 PMCID: PMC10645975 DOI: 10.1038/s41467-023-42922-y] [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: 02/14/2023] [Accepted: 10/26/2023] [Indexed: 11/16/2023] Open
Abstract
Epilepsy is a neurological disorder that poses a major threat to public health. Hyperactivation of mTOR complex 1 (mTORC1) is believed to lead to abnormal network rhythmicity associated with epilepsy, and its inhibition is proposed to provide some therapeutic benefit. However, mTOR complex 2 (mTORC2) is also activated in the epileptic brain, and little is known about its role in seizures. Here we discover that genetic deletion of mTORC2 from forebrain neurons is protective against kainic acid-induced behavioral and EEG seizures. Furthermore, inhibition of mTORC2 with a specific antisense oligonucleotide robustly suppresses seizures in several pharmacological and genetic mouse models of epilepsy. Finally, we identify a target of mTORC2, Nav1.2, which has been implicated in epilepsy and neuronal excitability. Our findings, which are generalizable to several models of human seizures, raise the possibility that inhibition of mTORC2 may serve as a broader therapeutic strategy against epilepsy.
Collapse
Affiliation(s)
- James Okoh
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA
- Altos Labs Inc, Bay Area Institute, Redwood City, CA, USA
| | - Jacqunae Mays
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA
| | - Alexandre Bacq
- Institut du Cerveau-Paris Brain Institute-ICM, Sorbonne Université, Inserm, CNRS, Hôpital de la Pitié Salpêtrière, F-75013, Paris, France
| | - Juan A Oses-Prieto
- Departments of Chemistry and Pharmaceutical Chemistry, University of California San Fransisco, San Fransisco, CA, USA
| | - Stefka Tyanova
- Altos Labs Inc, Bay Area Institute, Redwood City, CA, USA
| | - Chien-Ju Chen
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA
- Novartis Inc, Boston, MA, USA
| | - Khalel Imanbeyev
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA
| | - Marion Doladilhe
- Institut du Cerveau-Paris Brain Institute-ICM, Sorbonne Université, Inserm, CNRS, Hôpital de la Pitié Salpêtrière, F-75013, Paris, France
| | - Hongyi Zhou
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA
- Altos Labs Inc, Bay Area Institute, Redwood City, CA, USA
| | | | - Alma Burlingame
- Departments of Chemistry and Pharmaceutical Chemistry, University of California San Fransisco, San Fransisco, CA, USA
| | - Jeffrey Noebels
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
| | - Stephanie Baulac
- Institut du Cerveau-Paris Brain Institute-ICM, Sorbonne Université, Inserm, CNRS, Hôpital de la Pitié Salpêtrière, F-75013, Paris, France
| | - Mauro Costa-Mattioli
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA.
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA.
- Altos Labs Inc, Bay Area Institute, Redwood City, CA, USA.
| |
Collapse
|
10
|
Jung H, Kim S, Ko J, Um JW. Intracellular signaling mechanisms that shape postsynaptic GABAergic synapses. Curr Opin Neurobiol 2023; 81:102728. [PMID: 37236068 DOI: 10.1016/j.conb.2023.102728] [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: 02/12/2023] [Revised: 04/21/2023] [Accepted: 04/23/2023] [Indexed: 05/28/2023]
Abstract
Postsynaptic GABAergic receptors interact with various membrane and intracellular proteins to mediate inhibitory synaptic transmission. They form structural and/or signaling synaptic protein complexes that perform a variety of postsynaptic functions. In particular, the key GABAergic synaptic scaffold, gephyrin, and its interacting partners govern downstream signaling pathways that are essential for GABAergic synapse development, transmission, and plasticity. In this review, we discuss recent researches on GABAergic synaptic signaling pathways. We also outline the main outstanding issues that need to be addressed in this field and highlight the association of dysregulated GABAergic synaptic signaling with the onset of various brain disorders.
Collapse
Affiliation(s)
- Hyeji Jung
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu 42988, South Korea
| | - Seungjoon Kim
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu 42988, South Korea; Center for Synapse Diversity and Specificity, DGIST, 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu 42988, South Korea
| | - Jaewon Ko
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu 42988, South Korea; Center for Synapse Diversity and Specificity, DGIST, 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu 42988, South Korea
| | - Ji Won Um
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu 42988, South Korea; Center for Synapse Diversity and Specificity, DGIST, 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu 42988, South Korea.
| |
Collapse
|
11
|
Voss AJ, Lanjewar SN, Sampson MM, King A, Hill EJ, Sing A, Sojka C, Bhatia TN, Spangle JM, Sloan SA. Identification of ligand-receptor pairs that drive human astrocyte development. Nat Neurosci 2023; 26:1339-1351. [PMID: 37460808 PMCID: PMC11046429 DOI: 10.1038/s41593-023-01375-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 06/08/2023] [Indexed: 08/05/2023]
Abstract
Extrinsic signaling between diverse cell types is crucial for nervous system development. Ligand binding is a key driver of developmental processes. Nevertheless, it remains a significant challenge to disentangle which and how extrinsic signals act cooperatively to affect changes in recipient cells. In the developing human brain, cortical progenitors transition from neurogenesis to gliogenesis in a stereotyped sequence that is in part influenced by extrinsic ligands. Here we used published transcriptomic data to identify and functionally test five ligand-receptor pairs that synergistically drive human astrogenesis. We validate the synergistic contributions of TGFβ2, NLGN1, TSLP, DKK1 and BMP4 ligands on astrocyte development in both hCOs and primary fetal tissue. We confirm that the cooperative capabilities of these five ligands are greater than their individual capacities. Additionally, we discovered that their combinatorial effects converge in part on the mTORC1 signaling pathway, resulting in transcriptomic and morphological features of astrocyte development. Our data-driven framework can leverage single-cell and bulk genomic data to generate and test functional hypotheses surrounding cell-cell communication regulating neurodevelopmental processes.
Collapse
Affiliation(s)
- Anna J Voss
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | - Samantha N Lanjewar
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | - Maureen M Sampson
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | - Alexia King
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | - Emily J Hill
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | - Anson Sing
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | - Caitlin Sojka
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | - Tarun N Bhatia
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | - Jennifer M Spangle
- Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA, USA
| | - Steven A Sloan
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA.
| |
Collapse
|
12
|
Fidalgo da Silva E, Abu Khatir B, Drouillard C, Hinch I, Davis GO, Sameem M, Patel R, Fong J, Lubanska D, Porter LA. Tuberin levels during cellular differentiation in brain development. Differentiation 2023; 130:43-50. [PMID: 36608575 DOI: 10.1016/j.diff.2022.12.004] [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: 10/18/2021] [Revised: 12/13/2022] [Accepted: 12/21/2022] [Indexed: 12/26/2022]
Abstract
Tuberin is a member of a large protein complex, Tuberous Sclerosis Complex (TSC), and acts as a sensor for nutrient status regulating protein synthesis and cell cycle progression. Mutations in the Tuberin gene, TSC2, permits the formation of tumors that can lead to developmental defects in many organ systems, including the central nervous system. Tuberin is expressed in the brain throughout development and levels of Tuberin have been found to decrease during neuronal differentiation in cell lines in vitro. Our current work investigates the levels of Tuberin at two stages of embryonic development in vivo, and we study the mRNA and protein levels during a time course using immortalized cell lines in vitro. Our results show that total Tuberin levels are tightly regulated through developmental stages in the embryonic brain. At a cell biology level, we show that Tuberin levels are higher when cells are cultured as neurospheres, and knockdown of Tuberin results in a reduction in the number of neurospheres. This functional data supports the hypothesis that Tuberin is an important regulator of stemness and the reduction of Tuberin levels might support functional differentiation in the central nervous system. Understanding how Tuberin expression is regulated throughout neural development is essential to fully comprehend the role of this protein in several developmental and neural pathologies.
Collapse
Affiliation(s)
- Elizabeth Fidalgo da Silva
- Department of Biomedical Sciences, University of Windsor, 401 Sunset Ave. Windsor, Ontario, N9B 3P4, Canada
| | - Bashaer Abu Khatir
- Department of Biomedical Sciences, University of Windsor, 401 Sunset Ave. Windsor, Ontario, N9B 3P4, Canada
| | - Christopher Drouillard
- Department of Biomedical Sciences, University of Windsor, 401 Sunset Ave. Windsor, Ontario, N9B 3P4, Canada
| | - Isabelle Hinch
- Department of Biomedical Sciences, University of Windsor, 401 Sunset Ave. Windsor, Ontario, N9B 3P4, Canada
| | - Gordon Omar Davis
- Department of Biomedical Sciences, University of Windsor, 401 Sunset Ave. Windsor, Ontario, N9B 3P4, Canada
| | - Mariam Sameem
- Department of Biomedical Sciences, University of Windsor, 401 Sunset Ave. Windsor, Ontario, N9B 3P4, Canada
| | - Rutu Patel
- Department of Biomedical Sciences, University of Windsor, 401 Sunset Ave. Windsor, Ontario, N9B 3P4, Canada
| | - Jackie Fong
- Department of Biomedical Sciences, University of Windsor, 401 Sunset Ave. Windsor, Ontario, N9B 3P4, Canada
| | - Dorota Lubanska
- Department of Biomedical Sciences, University of Windsor, 401 Sunset Ave. Windsor, Ontario, N9B 3P4, Canada
| | - Lisa A Porter
- Department of Biomedical Sciences, University of Windsor, 401 Sunset Ave. Windsor, Ontario, N9B 3P4, Canada.
| |
Collapse
|
13
|
Developing Novel Experimental Models of m-TORopathic Epilepsy and Related Neuropathologies: Translational Insights from Zebrafish. Int J Mol Sci 2023; 24:ijms24021530. [PMID: 36675042 PMCID: PMC9866103 DOI: 10.3390/ijms24021530] [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: 12/09/2022] [Revised: 12/28/2022] [Accepted: 12/29/2022] [Indexed: 01/15/2023] Open
Abstract
The mammalian target of rapamycin (mTOR) is an important molecular regulator of cell growth and proliferation. Brain mTOR activity plays a crucial role in synaptic plasticity, cell development, migration and proliferation, as well as memory storage, protein synthesis, autophagy, ion channel expression and axonal regeneration. Aberrant mTOR signaling causes a diverse group of neurological disorders, termed 'mTORopathies'. Typically arising from mutations within the mTOR signaling pathway, these disorders are characterized by cortical malformations and other neuromorphological abnormalities that usually co-occur with severe, often treatment-resistant, epilepsy. Here, we discuss recent advances and current challenges in developing experimental models of mTOR-dependent epilepsy and other related mTORopathies, including using zebrafish models for studying these disorders, as well as outline future directions of research in this field.
Collapse
|
14
|
Bertocchi I, Cambiaghi M, Hasan MT. Advances toward precision therapeutics for developmental and epileptic encephalopathies. Front Neurosci 2023; 17:1140679. [PMID: 37090807 PMCID: PMC10115946 DOI: 10.3389/fnins.2023.1140679] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 03/16/2023] [Indexed: 04/25/2023] Open
Abstract
Developmental and epileptic encephalopathies are childhood syndromes of severe epilepsy associated with cognitive and behavioral disorders. Of note, epileptic seizures represent only a part, although substantial, of the clinical spectrum. Whether the epileptiform activity per se accounts for developmental and intellectual disabilities is still unclear. In a few cases, seizures can be alleviated by antiseizure medication (ASM). However, the major comorbid features associated remain unsolved, including psychiatric disorders such as autism-like and attention deficit hyperactivity disorder-like behavior. Not surprisingly, the number of genes known to be involved is continuously growing, and genetically engineered rodent models are valuable tools for investigating the impact of gene mutations on local and distributed brain circuits. Despite the inconsistencies and problems arising in the generation and validation of the different preclinical models, those are unique and precious tools to identify new molecular targets, and essential to provide prospects for effective therapeutics.
Collapse
Affiliation(s)
- Ilaria Bertocchi
- Laboratory of Neuropsychopharmacology, Department of Neuroscience Rita Levi Montalcini, Institute of Neuroscience Cavalieri Ottolenghi (NICO), University of Turin, Torino, Italy
- Department of Neuroscience Rita Levi Montalcini, Neuroscience Institute of Turin (NIT), Torino, Italy
- *Correspondence: Ilaria Bertocchi,
| | - Marco Cambiaghi
- Department Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Mazahir T. Hasan
- Laboratory of Brain Circuits Therapeutics, Achucarro Basque Center for Neuroscience, Leioa, Spain
- Ikerbasque – Basque Foundation for Science, Bilbao, Spain
| |
Collapse
|
15
|
Kong X, Shu X, Wang J, Liu D, Ni Y, Zhao W, Wang L, Gao Z, Chen J, Yang B, Guo X, Wang Z. Fine-tuning of mTOR signaling by the UBE4B-KLHL22 E3 ubiquitin ligase cascade in brain development. Development 2022; 149:286123. [PMID: 36440598 PMCID: PMC9845739 DOI: 10.1242/dev.201286] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 11/15/2022] [Indexed: 11/29/2022]
Abstract
Spatiotemporal regulation of the mechanistic target of rapamycin (mTOR) pathway is pivotal for establishment of brain architecture. Dysregulation of mTOR signaling is associated with a variety of neurodevelopmental disorders. Here, we demonstrate that the UBE4B-KLHL22 E3 ubiquitin ligase cascade regulates mTOR activity in neurodevelopment. In a mouse model with UBE4B conditionally deleted in the nervous system, animals display severe growth defects, spontaneous seizures and premature death. Loss of UBE4B in the brains of mutant mice results in depletion of neural precursor cells and impairment of neurogenesis. Mechanistically, UBE4B polyubiquitylates and degrades KLHL22, an E3 ligase previously shown to degrade the GATOR1 component DEPDC5. Deletion of UBE4B causes upregulation of KLHL22 and hyperactivation of mTOR, leading to defective proliferation and differentiation of neural precursor cells. Suppression of KLHL22 expression reverses the elevated activity of mTOR caused by acute local deletion of UBE4B. Prenatal treatment with the mTOR inhibitor rapamycin rescues neurogenesis defects in Ube4b mutant mice. Taken together, these findings demonstrate that UBE4B and KLHL22 are essential for maintenance and differentiation of the precursor pool through fine-tuning of mTOR activity.
Collapse
Affiliation(s)
- Xiangxing Kong
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou 310058, China,The MOE Frontier Science Center for Brain Research and Brain-Machine Integration, Zhejiang University School of Brain Science and Brain Medicine, Hangzhou 310058, China
| | - Xin Shu
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Jiachuan Wang
- Zhejiang University-University of Edinburgh Institute, Zhejiang University, Haining 314400, China,Deanery of Biomedical Sciences, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, EH8 9YL, UK
| | - Dandan Liu
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Yingchun Ni
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou 310058, China,The MOE Frontier Science Center for Brain Research and Brain-Machine Integration, Zhejiang University School of Brain Science and Brain Medicine, Hangzhou 310058, China
| | - Weiqi Zhao
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou 310058, China,The MOE Frontier Science Center for Brain Research and Brain-Machine Integration, Zhejiang University School of Brain Science and Brain Medicine, Hangzhou 310058, China
| | - Lebo Wang
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou 310058, China,The MOE Frontier Science Center for Brain Research and Brain-Machine Integration, Zhejiang University School of Brain Science and Brain Medicine, Hangzhou 310058, China
| | - Zhihua Gao
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou 310058, China,The MOE Frontier Science Center for Brain Research and Brain-Machine Integration, Zhejiang University School of Brain Science and Brain Medicine, Hangzhou 310058, China
| | - Jiadong Chen
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou 310058, China,The MOE Frontier Science Center for Brain Research and Brain-Machine Integration, Zhejiang University School of Brain Science and Brain Medicine, Hangzhou 310058, China
| | - Bing Yang
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China,Authors for correspondence (; ; )
| | - Xing Guo
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China,Authors for correspondence (; ; )
| | - Zhiping Wang
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou 310058, China,The MOE Frontier Science Center for Brain Research and Brain-Machine Integration, Zhejiang University School of Brain Science and Brain Medicine, Hangzhou 310058, China,Authors for correspondence (; ; )
| |
Collapse
|
16
|
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
|
17
|
Champion JD, Dodd KM, Lam HC, Alzahrani MAM, Seifan S, Rad E, Scourfield DO, Fishel ML, Calver BL, Ager A, Henske EP, Davies DM, Kelley MR, Tee AR. Drug Inhibition of Redox Factor-1 Restores Hypoxia-Driven Changes in Tuberous Sclerosis Complex 2 Deficient Cells. Cancers (Basel) 2022; 14:6195. [PMID: 36551683 PMCID: PMC9776744 DOI: 10.3390/cancers14246195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 10/17/2022] [Accepted: 12/02/2022] [Indexed: 12/23/2022] Open
Abstract
Therapies with the mechanistic target of rapamycin complex 1 (mTORC1) inhibitors are not fully curative for tuberous sclerosis complex (TSC) patients. Here, we propose that some mTORC1-independent disease facets of TSC involve signaling through redox factor-1 (Ref-1). Ref-1 possesses a redox signaling activity that stimulates the transcriptional activity of STAT3, NF-kB, and HIF-1α, which are involved in inflammation, proliferation, angiogenesis, and hypoxia, respectively. Here, we demonstrate that redox signaling through Ref-1 contributes to metabolic transformation and tumor growth in TSC cell model systems. In TSC2-deficient cells, the clinically viable Ref-1 inhibitor APX3330 was effective at blocking the hyperactivity of STAT3, NF-kB, and HIF-1α. While Ref-1 inhibitors do not inhibit mTORC1, they potently block cell invasion and vasculature mimicry. Of interest, we show that cell invasion and vasculature mimicry linked to Ref-1 redox signaling are not blocked by mTORC1 inhibitors. Metabolic profiling revealed that Ref-1 inhibitors alter metabolites associated with the glutathione antioxidant pathway as well as metabolites that are heavily dysregulated in TSC2-deficient cells involved in redox homeostasis. Therefore, this work presents Ref-1 and associated redox-regulated transcription factors such as STAT3, NF-kB, and HIF-1α as potential therapeutic targets to treat TSC, where targeting these components would likely have additional benefits compared to using mTORC1 inhibitors alone.
Collapse
Affiliation(s)
- Jesse D. Champion
- Division of Cancer and Genetics, Cardiff University, Heath Park, Cardiff CF14 4XN, UK
| | - Kayleigh M. Dodd
- Division of Cancer and Genetics, Cardiff University, Heath Park, Cardiff CF14 4XN, UK
| | - Hilaire C. Lam
- Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | | | - Sara Seifan
- Division of Cancer and Genetics, Cardiff University, Heath Park, Cardiff CF14 4XN, UK
| | - Ellie Rad
- Division of Cancer and Genetics, Cardiff University, Heath Park, Cardiff CF14 4XN, UK
| | | | - Melissa L. Fishel
- Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Brian L. Calver
- Division of Cancer and Genetics, Cardiff University, Heath Park, Cardiff CF14 4XN, UK
| | - Ann Ager
- Division of Infection and Immunity, Cardiff University, Heath Park, Cardiff CF14 4XN, UK
| | - Elizabeth P. Henske
- Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - David Mark Davies
- Division of Cancer and Genetics, Cardiff University, Heath Park, Cardiff CF14 4XN, UK
- Department of Oncology, South West Wales Cancer Centre, Singleton Hospital, Swansea SA2 8QA, UK
| | - Mark R. Kelley
- Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Andrew R. Tee
- Division of Cancer and Genetics, Cardiff University, Heath Park, Cardiff CF14 4XN, UK
| |
Collapse
|
18
|
Zhang J, Xu S, Liang K, Cao X, Ye Z, Huang W, Bai X, Zhang Y. LysM-positive neurons drive Tuberous Sclerosis Complex (TSC)-associated brain lesions. Cell Signal 2022; 100:110468. [PMID: 36115548 DOI: 10.1016/j.cellsig.2022.110468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 09/01/2022] [Accepted: 09/09/2022] [Indexed: 11/22/2022]
Abstract
Mutations of Tsc1 or Tsc2 can lead to excessive activation of mTORC1 and cause Tuberous Sclerosis Complex (TSC), which is an autosomal dominant genetic disease prominently characterized by seizures, mental retardation and multiorgan hamartoma. In TSC, pathological changes in the central nervous system are the leading cause of death and disability. In decades, series of rodent models have been established by mutating Tsc1 or Tsc2 genes in diverse neural cell lineages to investigate the underlying cellular and molecular mechanisms, however, the cellular origin triggering neural pathological changes in TSC is undetermined. In this study, we generated a novel mouse model involving conditional deletion of Tsc1 in lysozyme 2 (Lyz2)-positive cells which replicated several features of brain lesions including epileptic seizures, megalencephaly, highly enlarged pS6-positive neurons and astrogliosis. In addition, we confirmed that bone marrow-derived myeloid cells including microglia with Tsc1 deficiency are not the decisive lineage in the cerebral pathologies in TSC. These histological assays in our murine model indicate an essential contribution of Lyz2-positive neurons to TSC progression. The Lyz2-positive neural population-specific onset of Tsc1 loss in murine postnatal brain might be the key to pathological phenotypes. Our findings thus provided evidences supporting new insights into the role of Lyz2-positive neurons in TSC events.
Collapse
Affiliation(s)
- Jiahuan Zhang
- Department of Cell Biology, School of Basic Medical Science, Southern Medical University, Guangzhou 510515, China
| | - Song Xu
- Department of Arthroplasty, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Kangyan Liang
- Department of Cell Biology, School of Basic Medical Science, Southern Medical University, Guangzhou 510515, China
| | - Xiong Cao
- Department of Neurobiology, School of Basic Medical Science, Southern Medical University, Guangzhou 510515, China
| | - Zhixin Ye
- Department of Cell Biology, School of Basic Medical Science, Southern Medical University, Guangzhou 510515, China
| | - Wenlan Huang
- Department of Cell Biology, School of Basic Medical Science, Southern Medical University, Guangzhou 510515, China
| | - Xiaochun Bai
- Department of Cell Biology, School of Basic Medical Science, Southern Medical University, Guangzhou 510515, China.
| | - Yue Zhang
- Department of Cell Biology, School of Basic Medical Science, Southern Medical University, Guangzhou 510515, China.
| |
Collapse
|
19
|
De Meulemeester AS, Heylen L, Siekierska A, Mills JD, Romagnolo A, Van Der Wel NN, Aronica E, de Witte PAM. Hyperactivation of mTORC1 in a double hit mutant zebrafish model of tuberous sclerosis complex causes increased seizure susceptibility and neurodevelopmental abnormalities. Front Cell Dev Biol 2022; 10:952832. [PMID: 36238691 PMCID: PMC9552079 DOI: 10.3389/fcell.2022.952832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 09/05/2022] [Indexed: 11/16/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is a multisystem genetic disorder caused by pathogenic variants in TSC1 and TSC2 genes. TSC patients present with seizures and brain abnormalities such as tubers and subependymal giant cells astrocytoma (SEGA). Despite common molecular and clinical features, the severity of the disease varies greatly, even intrafamilially. The second hit hypothesis suggests that an additional, inactivating mutation in the remaining functional allele causes a more severe phenotype and therefore explains the phenotypic variability. Recently, second hit mutations have been detected frequently in mTORopathies. To investigate the pathophysiological effects of second hit mutations, several mouse models have been developed. Here, we opted for a double mutant zebrafish model that carries a LOF mutation both in the tsc2 and the depdc5 gene. To the best of our knowledge, this is the first time a second-hit model has been studied in zebrafish. Significantly, the DEP domain-containing protein 5 (DEPDC5) gene has an important role in the regulation of mTORC1, and the combination of a germline TSC2 and somatic DEPDC5 mutation has been described in a TSC patient with intractable epilepsy. Our depdc5−/−x tsc2−/− double mutant zebrafish line displayed greatly increased levels of mammalian target of rapamycin (mTORC1) activity, augmented seizure susceptibility, and early lethality which could be rescued by rapamycin. Histological analysis of the brain revealed ventricular dilatation in the tsc2 and double homozygotes. RNA-sequencing showed a linear relation between the number of differentially expressed genes (DEGs) and the degree of mTORC1 hyperactivity. Enrichment analysis of their transcriptomes revealed that many genes associated with neurological developmental processes were downregulated and mitochondrial genes were upregulated. In particular, the transcriptome of human SEGA lesions overlapped strongly with the double homozygous zebrafish larvae. The data highlight the clinical relevance of the depdc5−/− x tsc2−/− double mutant zebrafish larvae that showed a more severe phenotype compared to the single mutants. Finally, analysis of gene-drug interactions identified interesting pharmacological targets for SEGA, underscoring the value of our small zebrafish vertebrate model for future drug discovery efforts.
Collapse
Affiliation(s)
| | - Lise Heylen
- Laboratory for Molecular Biodiscovery, KU Leuven, Leuven, Belgium
| | | | - James D. Mills
- Department of (Neuro)Pathology Amsterdam Neuroscience, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, United Kingdom
- Chalfont Centre for Epilepsy, Chalfont St Peter, United Kingdom
| | - Alessia Romagnolo
- Department of (Neuro)Pathology Amsterdam Neuroscience, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
| | - Nicole N. Van Der Wel
- Department of Medical Biology, Electron Microscopy Center Amsterdam, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
| | - Eleonora Aronica
- Department of (Neuro)Pathology Amsterdam Neuroscience, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
- Stichting Epilepsie Instelling Nederland (SEIN), Heemstede, Netherlands
| | - Peter A. M. de Witte
- Laboratory for Molecular Biodiscovery, KU Leuven, Leuven, Belgium
- *Correspondence: Peter A. M. de Witte,
| |
Collapse
|
20
|
Raptor downregulation rescues neuronal phenotypes in mouse models of Tuberous Sclerosis Complex. Nat Commun 2022; 13:4665. [PMID: 35945201 PMCID: PMC9363483 DOI: 10.1038/s41467-022-31961-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 07/08/2022] [Indexed: 12/16/2022] Open
Abstract
Tuberous Sclerosis Complex (TSC) is a neurodevelopmental disorder caused by mutations in the TSC1 or TSC2 genes, which encode proteins that negatively regulate mTOR complex 1 (mTORC1) signaling. Current treatment strategies focus on mTOR inhibition with rapamycin and its derivatives. While effective at improving some aspects of TSC, chronic rapamycin inhibits both mTORC1 and mTORC2 and is associated with systemic side-effects. It is currently unknown which mTOR complex is most relevant for TSC-related brain phenotypes. Here we used genetic strategies to selectively reduce neuronal mTORC1 or mTORC2 activity in mouse models of TSC. We find that reduction of the mTORC1 component Raptor, but not the mTORC2 component Rictor, rebalanced mTOR signaling in Tsc1 knock-out neurons. Raptor reduction was sufficient to improve several TSC-related phenotypes including neuronal hypertrophy, macrocephaly, impaired myelination, network hyperactivity, and premature mortality. Raptor downregulation represents a promising potential therapeutic intervention for the neurological manifestations of TSC.
Collapse
|
21
|
Wu X, Sosunov AA, Lado W, Teoh JJ, Ham A, Li H, Al-Dalahmah O, Gill BJA, Arancio O, Schevon CA, Frankel WN, McKhann GM, Sulzer D, Goldman JE, Tang G. Synaptic hyperexcitability of cytomegalic pyramidal neurons contributes to epileptogenesis in tuberous sclerosis complex. Cell Rep 2022; 40:111085. [PMID: 35858542 PMCID: PMC9376014 DOI: 10.1016/j.celrep.2022.111085] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 02/15/2022] [Accepted: 06/22/2022] [Indexed: 11/27/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is a developmental disorder associated with epilepsy, autism, and cognitive impairment. Despite inactivating mutations in the TSC1 or TSC2 genes and hyperactive mechanistic target of rapamycin (mTOR) signaling, the mechanisms underlying TSC-associated neurological symptoms remain incompletely understood. Here we generate a Tsc1 conditional knockout (CKO) mouse model in which Tsc1 inactivation in late embryonic radial glia causes social and cognitive impairment and spontaneous seizures. Tsc1 depletion occurs in a subset of layer 2/3 cortical pyramidal neurons, leading to development of cytomegalic pyramidal neurons (CPNs) that mimic dysplastic neurons in human TSC, featuring abnormal dendritic and axonal overgrowth, enhanced glutamatergic synaptic transmission, and increased susceptibility to seizure-like activities. We provide evidence that enhanced synaptic excitation in CPNs contributes to cortical hyperexcitability and epileptogenesis. In contrast, astrocytic regulation of synapse formation and synaptic transmission remains unchanged after late embryonic radial glial Tsc1 inactivation, and astrogliosis evolves secondary to seizures. Wu et al. demonstrate that Tsc1 inactivation in late embryonic radial glial cells (RGCs) produces cytomegalic pyramidal neurons that mimic TSC-like dysplastic neurons. They find that enhanced excitatory synaptic transmission in Tsc1-null cytomegalic pyramidal neurons contributes to cortical hyperexcitability and epileptogenesis.
Collapse
Affiliation(s)
- Xiaoping Wu
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Alexander A Sosunov
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Wudu Lado
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Jia Jie Teoh
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Ahrom Ham
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Hongyu Li
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Osama Al-Dalahmah
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Brian J A Gill
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Ottavio Arancio
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA; Department of Medicine, Columbia University Irving Medical Center, New York, NY 10032, USA; The Taub Institute, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Catherine A Schevon
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Wayne N Frankel
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Guy M McKhann
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - David Sulzer
- Department of Psychiatry, Columbia University Irving Medical Center, New York, NY 10032, USA; Department of Pharmacology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - James E Goldman
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA; The Taub Institute, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Guomei Tang
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA.
| |
Collapse
|
22
|
Saré RM, Torossian A, Loutaev I, Smith CB. Confirmation of Decreased Rates of Cerebral Protein Synthesis In Vivo in a Mouse Model of Tuberous Sclerosis Complex. eNeuro 2022; 9:ENEURO.0480-21.2022. [PMID: 35851298 PMCID: PMC9347307 DOI: 10.1523/eneuro.0480-21.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 04/29/2022] [Accepted: 05/23/2022] [Indexed: 11/21/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is an autosomal dominant disorder that results in intellectual disability and, in ∼50% of patients, autism spectrum disorder. The protein products that are altered in TSC (TSC1 and TSC2) form a complex to inhibit the mammalian target of rapamycin [mTOR; mTOR complex 1 (mTORC1)] pathway. This pathway has been shown to affect the process of mRNA translation through its action on ribosomal protein S6 and 4-elongation binding protein 1. It is thought that mutations in the TSC proteins lead to upregulation of the mTORC1 pathway and consequently an increase in protein synthesis. Unexpectedly, our previous study of a mouse model of TSC (Tsc2Djk +/) demonstrated decreased in vivo rates of protein synthesis throughout the brain. In the present study, we confirm those results in another Tsc2+/- mouse model, one with a different mutation locus and on a mixed background (Tsc2Mjg +/-). We also examine mTORC1 signaling and possible effects of prior isoflurane anesthesia. Because measurements of protein synthesis rates in vivo require surgical preparation of the animal and anesthesia, we examine mTORC1 signaling pathways both under baseline conditions and following recovery from anesthesia. Our results demonstrate regionally selective effects of prior anesthesia. Overall, our results in both in vivo models suggest differences to the central hypothesis regarding TSC and show the importance of studying protein synthesis in vivo Significance StatementProtein synthesis is an important process for brain function. In the disorder, tuberous sclerosis complex (TSC), the inhibition of the mammalian target of rapamycin (mTOR) pathway is reduced and this is thought to lead to excessive protein synthesis. Most studies of protein synthesis in models of TSC have been conducted in vitro We report here confirmation of our previous in vivo study showing decreased brain protein synthesis rates in a second mouse model of TSC, results counter to the central hypothesis regarding TSC. We also explore the possible influence of prior isoflurane exposure on signaling pathways involved in regulation of protein synthesis. This study highlights a novel aspect of TSC and the importance of studying cellular processes in vivo.
Collapse
Affiliation(s)
- Rachel Michelle Saré
- Department of Health and Human Services, Section on Neuroadaptation and Protein Metabolism, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20814
| | - Anita Torossian
- Department of Health and Human Services, Section on Neuroadaptation and Protein Metabolism, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20814
| | - Inna Loutaev
- Department of Health and Human Services, Section on Neuroadaptation and Protein Metabolism, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20814
| | - Carolyn Beebe Smith
- Department of Health and Human Services, Section on Neuroadaptation and Protein Metabolism, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20814
| |
Collapse
|
23
|
Nguyen LH, Bordey A. Current Review in Basic Science: Animal Models of Focal Cortical Dysplasia and Epilepsy. Epilepsy Curr 2022; 22:234-240. [PMID: 36187145 PMCID: PMC9483763 DOI: 10.1177/15357597221098230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Focal cortical dysplasia (FCD) is a malformation of cortical development that is a prevalent cause of intractable epilepsy in children. Of the three FCD subtypes, understanding the etiology and pathogenesis of FCD type II has seen the most progress owing to the recent advances in identifying gene mutations along the mTOR signaling pathway as a frequent cause of this disorder. Accordingly, numerous animal models of FCD type II based on genetic manipulation of the mTOR signaling pathway have emerged to investigate the mechanisms of epileptogenesis and novel therapeutics for epilepsy. These include transgenic and in utero electroporation-based animal models. Here, we review the histopathological and electroclinical features of existing FCD type II animal models and discuss the scientific and technical considerations, clinical applications, and limitations of current models. We also highlight other models of FCD based on early life acquired factors.
Collapse
Affiliation(s)
- Lena H. Nguyen
- Departments of Neurosurgery and Cellular & Molecular
Physiology, Yale University School of
Medicine, New Haven, CT, USA
| | - Angélique Bordey
- Departments of Neurosurgery and Cellular & Molecular
Physiology, Yale University School of
Medicine, New Haven, CT, USA
| |
Collapse
|
24
|
Zoungrana LI, Krause-Hauch M, Wang H, Fatmi MK, Bates L, Li Z, Kulkarni P, Ren D, Li J. The Interaction of mTOR and Nrf2 in Neurogenesis and Its Implication in Neurodegenerative Diseases. Cells 2022; 11:cells11132048. [PMID: 35805130 PMCID: PMC9265429 DOI: 10.3390/cells11132048] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 06/23/2022] [Accepted: 06/26/2022] [Indexed: 12/24/2022] Open
Abstract
Neurogenesis occurs in the brain during embryonic development and throughout adulthood. Neurogenesis occurs in the hippocampus and under normal conditions and persists in two regions of the brain—the subgranular zone (SGZ) in the dentate gyrus of the hippocampus and the subventricular zone (SVZ) of the lateral ventricles. As the critical role in neurogenesis, the neural stem cells have the capacity to differentiate into various cells and to self-renew. This process is controlled through different methods. The mammalian target of rapamycin (mTOR) controls cellular growth, cell proliferation, apoptosis, and autophagy. The transcription factor Nrf2 (nuclear factor erythroid 2-related factor 2) is a major regulator of metabolism, protein quality control, and antioxidative defense, and is linked to neurogenesis. However, dysregulation in neurogenesis, mTOR, and Nrf2 activity have all been associated with neurodegenerative diseases such as Alzheimer’s, Huntington’s, and Parkinson’s. Understanding the role of these complexes in both neurogenesis and neurodegenerative disease could be necessary to develop future therapies. Here, we review both mTOR and Nrf2 complexes, their crosstalk and role in neurogenesis, and their implication in neurodegenerative diseases.
Collapse
Affiliation(s)
- Linda Ines Zoungrana
- Department of Surgery, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA; (L.I.Z.); (M.K.-H.); (H.W.); (M.K.F.); (L.B.); (D.R.)
| | - Meredith Krause-Hauch
- Department of Surgery, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA; (L.I.Z.); (M.K.-H.); (H.W.); (M.K.F.); (L.B.); (D.R.)
| | - Hao Wang
- Department of Surgery, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA; (L.I.Z.); (M.K.-H.); (H.W.); (M.K.F.); (L.B.); (D.R.)
| | - Mohammad Kasim Fatmi
- Department of Surgery, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA; (L.I.Z.); (M.K.-H.); (H.W.); (M.K.F.); (L.B.); (D.R.)
| | - Lauryn Bates
- Department of Surgery, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA; (L.I.Z.); (M.K.-H.); (H.W.); (M.K.F.); (L.B.); (D.R.)
| | - Zehui Li
- Department of Medical Engineering, College of Engineering and Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA; (Z.L.); (P.K.)
| | - Parth Kulkarni
- Department of Medical Engineering, College of Engineering and Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA; (Z.L.); (P.K.)
| | - Di Ren
- Department of Surgery, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA; (L.I.Z.); (M.K.-H.); (H.W.); (M.K.F.); (L.B.); (D.R.)
| | - Ji Li
- Department of Surgery, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA; (L.I.Z.); (M.K.-H.); (H.W.); (M.K.F.); (L.B.); (D.R.)
- Correspondence: ; Tel.: +1-813-974-4917
| |
Collapse
|
25
|
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
|
26
|
Schrötter S, Yuskaitis CJ, MacArthur MR, Mitchell SJ, Hosios AM, Osipovich M, Torrence ME, Mitchell JR, Hoxhaj G, Sahin M, Manning BD. The non-essential TSC complex component TBC1D7 restricts tissue mTORC1 signaling and brain and neuron growth. Cell Rep 2022; 39:110824. [PMID: 35584673 PMCID: PMC9175135 DOI: 10.1016/j.celrep.2022.110824] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 03/21/2022] [Accepted: 04/23/2022] [Indexed: 11/16/2022] Open
Abstract
The tuberous sclerosis complex (TSC) 1 and 2 proteins associate with TBC1D7 to form the TSC complex, which is an essential suppressor of mTOR complex 1 (mTORC1), a ubiquitous driver of cell and tissue growth. Loss-of-function mutations in TSC1 or TSC2, but not TBC1D7, give rise to TSC, a pleiotropic disorder with aberrant activation of mTORC1 in various tissues. Here, we characterize mice with genetic deletion of Tbc1d7, which are viable with normal growth and development. Consistent with partial loss of function of the TSC complex, Tbc1d7 knockout (KO) mice display variable increases in tissue mTORC1 signaling with increased muscle fiber size but with strength and motor defects. Their most pronounced phenotype is brain overgrowth due to thickening of the cerebral cortex, with enhanced neuron-intrinsic mTORC1 signaling and growth. Thus, TBC1D7 is required for full TSC complex function in tissues, and the brain is particularly sensitive to its growth-suppressing activities.
Collapse
Affiliation(s)
- Sandra Schrötter
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Christopher J Yuskaitis
- Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Michael R MacArthur
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Sarah J Mitchell
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Aaron M Hosios
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Maria Osipovich
- Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Margaret E Torrence
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - James R Mitchell
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Gerta Hoxhaj
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Mustafa Sahin
- Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Brendan D Manning
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Department of Cell Biology, Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
27
|
Nisar S, Bhat AA, Masoodi T, Hashem S, Akhtar S, Ali TA, Amjad S, Chawla S, Bagga P, Frenneaux MP, Reddy R, Fakhro K, Haris M. Genetics of glutamate and its receptors in autism spectrum disorder. Mol Psychiatry 2022; 27:2380-2392. [PMID: 35296811 PMCID: PMC9135628 DOI: 10.1038/s41380-022-01506-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 02/11/2022] [Accepted: 02/22/2022] [Indexed: 12/11/2022]
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental impairment characterized by deficits in social interaction skills, impaired communication, and repetitive and restricted behaviors that are thought to be due to altered neurotransmission processes. The amino acid glutamate is an essential excitatory neurotransmitter in the human brain that regulates cognitive functions such as learning and memory, which are usually impaired in ASD. Over the last several years, increasing evidence from genetics, neuroimaging, protein expression, and animal model studies supporting the notion of altered glutamate metabolism has heightened the interest in evaluating glutamatergic dysfunction in ASD. Numerous pharmacological, behavioral, and imaging studies have demonstrated the imbalance in excitatory and inhibitory neurotransmitters, thus revealing the involvement of the glutamatergic system in ASD pathology. Here, we review the effects of genetic alterations on glutamate and its receptors in ASD and the role of non-invasive imaging modalities in detecting these changes. We also highlight the potential therapeutic targets associated with impaired glutamatergic pathways.
Collapse
Affiliation(s)
- Sabah Nisar
- Laboratory of Molecular and Metabolic Imaging, Sidra Medicine, P.O. Box 26999, Doha, Qatar
| | - Ajaz A Bhat
- Laboratory of Molecular and Metabolic Imaging, Sidra Medicine, P.O. Box 26999, Doha, Qatar
| | - Tariq Masoodi
- Laboratory of Molecular and Metabolic Imaging, Sidra Medicine, P.O. Box 26999, Doha, Qatar
| | - Sheema Hashem
- Laboratory of Molecular and Metabolic Imaging, Sidra Medicine, P.O. Box 26999, Doha, Qatar
| | - Sabah Akhtar
- Laboratory of Molecular and Metabolic Imaging, Sidra Medicine, P.O. Box 26999, Doha, Qatar
| | - Tayyiba Akbar Ali
- Laboratory of Molecular and Metabolic Imaging, Sidra Medicine, P.O. Box 26999, Doha, Qatar
| | - Sara Amjad
- Shibli National College, Azamgarh, Uttar Pradesh, 276001, India
| | - Sanjeev Chawla
- Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Puneet Bagga
- Department of Diagnostic Imaging, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Michael P Frenneaux
- Academic Health System, Hamad Medical Corporation, P.O. Box 3050, Doha, Qatar
| | - Ravinder Reddy
- Center for Advanced Metabolic Imaging in Precision Medicine, Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Khalid Fakhro
- Department of Human Genetics, Sidra Medicine, P.O. Box 26999, Doha, Qatar
- Department of Genetic Medicine, Weill Cornell Medical College, P.O. Box 24144, Doha, Qatar
| | - Mohammad Haris
- Laboratory of Molecular and Metabolic Imaging, Sidra Medicine, P.O. Box 26999, Doha, Qatar.
- Center for Advanced Metabolic Imaging in Precision Medicine, Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, USA.
- Laboratory of Animal Research, Qatar University, P.O. Box 2713, Doha, Qatar.
| |
Collapse
|
28
|
Wang R, Amoyel M. mRNA Translation Is Dynamically Regulated to Instruct Stem Cell Fate. Front Mol Biosci 2022; 9:863885. [PMID: 35433828 PMCID: PMC9008482 DOI: 10.3389/fmolb.2022.863885] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 02/25/2022] [Indexed: 12/12/2022] Open
Abstract
Stem cells preserve tissue homeostasis by replacing the cells lost through damage or natural turnover. Thus, stem cells and their daughters can adopt two identities, characterized by different programs of gene expression and metabolic activity. The composition and regulation of these programs have been extensively studied, particularly by identifying transcription factor networks that define cellular identity and the epigenetic changes that underlie the progressive restriction in gene expression potential. However, there is increasing evidence that post-transcriptional mechanisms influence gene expression in stem cells and their progeny, in particular through the control of mRNA translation. Here, we review the described roles of translational regulation in controlling all aspects of stem cell biology, from the decision to enter or exit quiescence to maintaining self-renewal and promoting differentiation. We focus on mechanisms controlling global translation rates in cells, mTOR signaling, eIF2ɑ phosphorylation, and ribosome biogenesis and how they allow stem cells to rapidly change their gene expression in response to tissue needs or environmental changes. These studies emphasize that translation acts as an additional layer of control in regulating gene expression in stem cells and that understanding this regulation is critical to gaining a full understanding of the mechanisms that underlie fate decisions in stem cells.
Collapse
Affiliation(s)
| | - Marc Amoyel
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| |
Collapse
|
29
|
ROCK ‘n TOR: An Outlook on Keratinocyte Stem Cell Expansion in Regenerative Medicine via Protein Kinase Inhibition. Cells 2022; 11:cells11071130. [PMID: 35406693 PMCID: PMC8997668 DOI: 10.3390/cells11071130] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/23/2022] [Accepted: 03/24/2022] [Indexed: 12/13/2022] Open
Abstract
Keratinocyte stem cells play a fundamental role in homeostasis and repair of stratified epithelial tissues. Transplantation of cultured keratinocytes autografts provides a landmark example of successful cellular therapies by restoring durable integrity in stratified epithelia lost to devastating tissue conditions. Despite the overall success of such procedures, failures still occur in case of paucity of cultured stem cells in therapeutic grafts. Strategies aiming at a further amplification of stem cells during keratinocyte ex vivo expansion may thus extend the applicability of these treatments to subjects in which endogenous stem cells pools are depauperated by aging, trauma, or disease. Pharmacological targeting of stem cell signaling pathways is recently emerging as a powerful strategy for improving stem cell maintenance and/or amplification. Recent experimental data indicate that pharmacological inhibition of two prominent keratinocyte signaling pathways governed by apical mTOR and ROCK protein kinases favor stem cell maintenance and/or amplification ex vivo and may improve the effectiveness of stem cell-based therapeutic procedures. In this review, we highlight the pathophysiological roles of mTOR and ROCK in keratinocyte biology and evaluate existing pre-clinical data on the effects of their inhibition in epithelial stem cell expansion for transplantation purposes.
Collapse
|
30
|
Nguyen LH, Leiser SC, Song D, Brunner D, Roberds SL, Wong M, Bordey A. Inhibition of MEK-ERK signaling reduces seizures in two mouse models of tuberous sclerosis complex. Epilepsy Res 2022; 181:106890. [PMID: 35219048 PMCID: PMC8930622 DOI: 10.1016/j.eplepsyres.2022.106890] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 02/02/2022] [Accepted: 02/17/2022] [Indexed: 12/25/2022]
Abstract
Tuberous sclerosis complex (TSC) is a monogenic disorder characterized by hyperactivation of the mTOR signaling pathway and developmental brain malformations leading to intractable epilepsy. Although treatment with the recently approved mTOR inhibitor, everolimus, results in clinically relevant seizure suppression in up to 40% of TSC patients, seizures remain uncontrolled in a large number of cases, underscoring the need to identify novel treatment targets. The MEK-ERK signaling pathway has been found to be aberrantly activated in TSC and inhibition of MEK-ERK activity independently of mTOR rescued neuronal dendrite overgrowth in mice modeling TSC neuropathology. Here, we evaluated the efficacy of MEK-ERK inhibition on seizures in two mouse models of TSC. We found that treatment with the MEK inhibitor PD0325901 (mirdametinib) significantly reduced seizure activity in both TSC mouse models. These findings support inhibiting MEK-ERK activity as a potential alternative strategy to treat seizures in TSC.
Collapse
Affiliation(s)
- Lena H. Nguyen
- Department of Neurosurgery, Yale University School of Medicine, New Haven, CT, USA,Department of Cellular & Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA
| | - Steven C. Leiser
- Department of Translational EEG, PsychoGenics, Inc., Paramus, NJ, USA
| | - Dekun Song
- Department of Translational EEG, PsychoGenics, Inc., Paramus, NJ, USA
| | | | | | - Michael Wong
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA
| | - Angelique Bordey
- Department of Neurosurgery, Yale University School of Medicine, New Haven, CT, USA; Department of Cellular & Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA.
| |
Collapse
|
31
|
Terry BK, Park R, Cho SH, Crino PB, Kim S. Abnormal activation of Yap/Taz contributes to the pathogenesis of tuberous sclerosis complex. Hum Mol Genet 2022; 31:1979-1996. [PMID: 34999833 PMCID: PMC9239747 DOI: 10.1093/hmg/ddab374] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 10/31/2021] [Accepted: 12/27/2021] [Indexed: 01/09/2023] Open
Abstract
The multi-systemic genetic disorder tuberous sclerosis complex (TSC) impacts multiple neurodevelopmental processes including neuronal morphogenesis, neuronal migration, myelination and gliogenesis. These alterations contribute to the development of cerebral cortex abnormalities and malformations. Although TSC is caused by mTORC1 hyperactivation, cognitive and behavioral impairments are not improved through mTORC1 targeting, making the study of the downstream effectors of this complex important for understanding the mechanisms underlying TSC. As mTORC1 has been shown to promote the activity of the transcriptional co-activator Yap, we hypothesized that altered Yap/Taz signaling contributes to the pathogenesis of TSC. We first observed that the levels of Yap/Taz are increased in human cortical tuber samples and in embryonic cortices of Tsc2 conditional knockout (cKO) mice. Next, to determine how abnormal upregulation of Yap/Taz impacts the neuropathology of TSC, we deleted Yap/Taz in Tsc2 cKO mice. Importantly, Yap/Taz/Tsc2 triple conditional knockout (tcKO) animals show reduced cortical thickness and cortical neuron cell size, despite the persistence of high mTORC1 activity, suggesting that Yap/Taz play a downstream role in cytomegaly. Furthermore, Yap/Taz/Tsc2 tcKO significantly restored cortical and hippocampal lamination defects and reduced hippocampal heterotopia formation. Finally, the loss of Yap/Taz increased the distribution of myelin basic protein in Tsc2 cKO animals, consistent with an improvement in myelination. Overall, our results indicate that targeting Yap/Taz lessens the severity of neuropathology in a TSC animal model. This study is the first to implicate Yap/Taz as contributors to cortical pathogenesis in TSC and therefore as potential novel targets in the treatment of this disorder.
Collapse
Affiliation(s)
- Bethany K Terry
- Department of Neural Sciences, Lewis Katz School of Medicine, Shriners Hospitals Pediatrics Research Center, Temple University, Philadelphia, PA 19140, USA,Biomedical Sciences Graduate Program, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Raehee Park
- Department of Neural Sciences, Lewis Katz School of Medicine, Shriners Hospitals Pediatrics Research Center, Temple University, Philadelphia, PA 19140, USA
| | - Seo-Hee Cho
- Department of Medicine, Sidney Kimmel Medical College, Center for Translational Medicine, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Peter B Crino
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Seonhee Kim
- To whom correspondence should be addressed. Tel: 215-926-9360; Fax: 215-926-9325;
| |
Collapse
|
32
|
Tong X, Wang X, Qin L, Zhou J, Guan Y, Teng P, Wang J, Yang Y, Li T, Luan G. Vagus nerve stimulation for drug-resistant epilepsy induced by tuberous sclerosis complex. Epilepsy Behav 2022; 126:108431. [PMID: 34883463 DOI: 10.1016/j.yebeh.2021.108431] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/22/2021] [Accepted: 11/05/2021] [Indexed: 11/03/2022]
Abstract
OBJECTIVE This study investigated the dynamic and long-term efficacy of vagus nerve stimulation (VNS) in patients with drug-resistant epilepsy (DRE) induced by tuberous sclerosis complex (TSC). In addition, the impact of VNS on cognition and emotion after a one-year follow-up was evaluated. METHODS A total of 17 patients diagnosed with DRE induced by TSC were retrospectively recruited between 2008 and 2019. Dynamic changes in seizure frequency were observed in the responders (≥50% reduction of seizure frequency at last follow-up) and non-responders. Clinical characteristics and seizure outcomes were comprehensively analyzed to determine factors associated with seizure outcomes. The Wechsler intelligence scale was applied in a subgroup of six pediatric patients, whereas the Self-rating Anxiety Scale (SAS) and Self-rating Depression Scale (SDS) were assessed in a subgroup of nine patients to determine the impact of VNS therapy on cognitive performance and emotional state. RESULTS The follow-up duration for the 17 patients who underwent VNS treatment ranged from 0.5 to 10 years (mean ± SD: 4.1 ± 3.2 years). Monthly seizures decreased significantly from three months to four years post-treatment (p < 0.05). At the last follow-up, 70.6% of the patients achieved at least a 50% reduction in seizure frequency, and three patients were completely seizure free. Comparatively, non-responder patients experienced deterioration of seizure frequency after the first year. Notably, after one-year follow-up the mean standard score of full-scale intelligence quotient increased from 67.33 to 69.5 (p = 0.078) while the mean, standard score of SDS decreased from 49.22 to 45.67 (p = 0.003) compared to preoperative neuropsychological evaluation results. CONCLUSION VNS is a safe and effective treatment for patients with DRE caused by TSC. Although early outcomes were encouraging, a follow-up of at least one-year was required to predict long-term outcomes in patients receiving VNS treatment. Moreover, VNS may improve depressive mood in patients with DRE caused by TSC. Further investigations are needed to validate the present results.
Collapse
Affiliation(s)
- Xuezhi Tong
- Department of Neurosurgery, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Xiongfei Wang
- Department of Neurosurgery, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China; Beijing Key Laboratory of Epilepsy, Beijing 100093, China; Epilepsy Institute, Beijing Institute for Brain Disorders, Beijing 100093, China
| | - Lang Qin
- McGovern Institute for Brain Research, Peking University, Beijing 100093, China; Center for MRI Research, Peking University, Beijing 100093, China
| | - Jian Zhou
- Department of Neurosurgery, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Yuguang Guan
- Department of Neurosurgery, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Pengfei Teng
- Department of Neurosurgery, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Jing Wang
- Department of Neurology, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Yujiao Yang
- Department of Neurology, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Tianfu Li
- Epilepsy Institute, Beijing Institute for Brain Disorders, Beijing 100093, China; Department of Neurology, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Guoming Luan
- Department of Neurosurgery, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China; Beijing Key Laboratory of Epilepsy, Beijing 100093, China; Epilepsy Institute, Beijing Institute for Brain Disorders, Beijing 100093, China.
| |
Collapse
|
33
|
Karra L, Roose JP. Investigating increased hematopoietic stem cell fitness in a novel mouse model. Small GTPases 2022; 13:7-13. [PMID: 33517841 PMCID: PMC9707538 DOI: 10.1080/21541248.2021.1882832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
T-cell acute lymphoblastic leukaemia (T-ALL) is a bone marrow (BM) malignancy affecting children and adults. Typically treated with chemotherapy, leukaemia remains a major death cause in people under 20 years old. Understanding molecularly altered pathways in T-ALL may lead to new therapeutic avenues in the future. Ras pathway dysregulation is common in T-ALL. We have shown elevated expression levels of the Ras guanine nucleotide exchange factor RasGRP1 in T-ALL patients, which results in constant production of active Ras (RasGTP). When leukaemia cell lines are exposed to cytokines, RasGTP levels further increase in a RasGRP1-dependent manner. How overexpressed RasGRP1 may impact primary BM cells has remained unknown. We recently published a new RoLoRiG mouse model that allows for pIpC-induced overexpression of RasGRP1 in haematopoietic cells, which can be traced with an ires-EGFP cassette. This novel model revealed that RasGRP1 overexpression bestows a fitness advantage to haematopoietic stem cells (HSCs) over wild-type cells. Intriguingly, this increased fitness only manifests in native Hematopoiesis, and not in BM transplantation (BMT) assays. In this commentary, we summarize key features of our RoLoRiG model, elaborate on BM niche importance, and discuss differences between native Hematopoiesis and BMT in the context of stem cell metabolism.
Collapse
Affiliation(s)
| | - Jeroen P. Roose
- Department of Anatomy, University of California, San Francisco, San Francisco, CaliforniaUSA,CONTACT Jeroen P. Roose Department of Anatomy, University of California San Francisco (UCSF) 513 Parnassus Avenue, Room HSW-1326, San Francisco, California94143-0452, USA
| |
Collapse
|
34
|
Fame RM, Lehtinen MK. Mitochondria in Early Forebrain Development: From Neurulation to Mid-Corticogenesis. Front Cell Dev Biol 2021; 9:780207. [PMID: 34888312 PMCID: PMC8650308 DOI: 10.3389/fcell.2021.780207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 11/10/2021] [Indexed: 01/07/2023] Open
Abstract
Function of the mature central nervous system (CNS) requires a substantial proportion of the body’s energy consumption. During development, the CNS anlage must maintain its structure and perform stage-specific functions as it proceeds through discrete developmental stages. While key extrinsic signals and internal transcriptional controls over these processes are well appreciated, metabolic and mitochondrial states are also critical to appropriate forebrain development. Specifically, metabolic state, mitochondrial function, and mitochondrial dynamics/localization play critical roles in neurulation and CNS progenitor specification, progenitor proliferation and survival, neurogenesis, neural migration, and neurite outgrowth and synaptogenesis. With the goal of integrating neurodevelopmental biologists and mitochondrial specialists, this review synthesizes data from disparate models and processes to compile and highlight key roles of mitochondria in the early development of the CNS with specific focus on forebrain development and corticogenesis.
Collapse
Affiliation(s)
- Ryann M Fame
- Department of Pathology, Boston Children's Hospital, Boston, MA, United States
| | - Maria K Lehtinen
- Department of Pathology, Boston Children's Hospital, Boston, MA, United States
| |
Collapse
|
35
|
Conti V, Cominelli M, Pieri V, Gallotti AL, Pagano I, Zanella M, Mazzoleni S, Pivetta F, Patanè M, Scotti GM, Piras IS, Pollo B, Falini A, Zippo A, Castellano A, Maestro R, Poliani PL, Galli R. mTORC1 promotes malignant large cell/anaplastic histology and is a targetable vulnerability in SHH-TP53 mutant medulloblastoma. JCI Insight 2021; 6:e153462. [PMID: 34673573 PMCID: PMC8675203 DOI: 10.1172/jci.insight.153462] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 10/20/2021] [Indexed: 11/18/2022] Open
Abstract
Medulloblastoma (MB), one of the most malignant brain tumors of childhood, comprises distinct molecular subgroups, with p53 mutant sonic hedgehog-activated (SHH-activated) MB patients having a very severe outcome that is associated with unfavorable histological large cell/anaplastic (LC/A) features. To identify the molecular underpinnings of this phenotype, we analyzed a large cohort of MB developing in p53-deficient Ptch+/- SHH mice that, unexpectedly, showed LC/A traits that correlated with mTORC1 hyperactivation. Mechanistically, mTORC1 hyperactivation was mediated by a decrease in the p53-dependent expression of mTORC1 negative regulator Tsc2. Ectopic mTORC1 activation in mouse MB cancer stem cells (CSCs) promoted the in vivo acquisition of LC/A features and increased malignancy; accordingly, mTORC1 inhibition in p53-mutant Ptch+/- SHH MB and CSC-derived MB resulted in reduced tumor burden and aggressiveness. Most remarkably, mTORC1 hyperactivation was detected only in p53-mutant SHH MB patient samples, and treatment with rapamycin of a human preclinical model phenocopying this subgroup decreased tumor growth and malignancy. Thus, mTORC1 may act as a specific druggable target for this subset of SHH MB, resulting in the implementation of a stringent risk stratification and in the potentially rapid translation of this precision medicine approach into the clinical setting.
Collapse
Affiliation(s)
- Valentina Conti
- Neural Stem Cell Biology Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Manuela Cominelli
- Pathology Unit, Molecular and Translational Medicine Department, University of Brescia, Brescia, Italy
| | - Valentina Pieri
- Neural Stem Cell Biology Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
- Functional Neuroradiology Unit, Vita-Salute San Raffaele University and San Raffaele Scientific Institute, Milan, Italy
| | - Alberto L. Gallotti
- Neural Stem Cell Biology Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Ilaria Pagano
- Neural Stem Cell Biology Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Matteo Zanella
- Neural Stem Cell Biology Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | | | - Flavia Pivetta
- Unit of Experimental Oncology 1, Centro di Riferimento Oncologico (CRO), Aviano National Cancer Institute, Aviano, Pordenone, Italy
| | - Monica Patanè
- Neuropathology Unit, Fondazione IRCCS Istituto Neurologico “C. Besta,” Milan, Italy
| | - Giulia M. Scotti
- Center for Omics Sciences, San Raffaele Scientific Institute, Milan, Italy
| | - Ignazio S. Piras
- Neurogenomics Division, Translational Genomics Research Institute (TGen), Phoenix, Arizona, USA
| | - Bianca Pollo
- Neuropathology Unit, Fondazione IRCCS Istituto Neurologico “C. Besta,” Milan, Italy
| | - Andrea Falini
- Functional Neuroradiology Unit, Vita-Salute San Raffaele University and San Raffaele Scientific Institute, Milan, Italy
| | - Alessio Zippo
- Istituto Nazionale di Genetica Molecolare (INGM), Milan, Italy
- Laboratory of Chromatin Biology & Epigenetics, Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Antonella Castellano
- Functional Neuroradiology Unit, Vita-Salute San Raffaele University and San Raffaele Scientific Institute, Milan, Italy
| | - Roberta Maestro
- Unit of Experimental Oncology 1, Centro di Riferimento Oncologico (CRO), Aviano National Cancer Institute, Aviano, Pordenone, Italy
| | - Pietro L. Poliani
- Pathology Unit, Molecular and Translational Medicine Department, University of Brescia, Brescia, Italy
| | - Rossella Galli
- Neural Stem Cell Biology Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| |
Collapse
|
36
|
Head B, Traber MG. Expanding role of vitamin E in protection against metabolic dysregulation: Insights gained from model systems, especially the developing nervous system of zebrafish embryos. Free Radic Biol Med 2021; 176:80-91. [PMID: 34555455 DOI: 10.1016/j.freeradbiomed.2021.09.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 07/27/2021] [Accepted: 09/07/2021] [Indexed: 12/20/2022]
Abstract
This review discusses why the embryo requires vitamin E (VitE) and shows that its lack causes metabolic dysregulation and impacts morphological changes at very early stages in development, which occur prior to when a woman knows she is pregnant. VitE halts the chain reactions of lipid peroxidation (LPO). Metabolomic analyses indicate that thiols become depleted in E- embryos because LPO generates products that require compensation using limited amino acids and methyl donors that are also developmentally relevant. Thus, VitE protects metabolic networks and the integrated gene expression networks that control development. VitE is critical especially for neurodevelopment, which is dependent on trafficking by the α-tocopherol transfer protein (TTPa). VitE-deficient (E-) zebrafish embryos initially appear normal, but by 12 and 24 h post-fertilization (hpf) E- embryos are developmentally abnormal with expression of pax2a and sox10 mis-localized in the midbrain-hindbrain boundary, neural crest cells and throughout the spinal neurons. These patterning defects indicate cells that are especially in need of VitE-protection. They precede obvious morphological abnormalities (cranial-facial malformation, pericardial edema, yolksac edema, skewed body-axis) and impaired behavioral responses to locomotor activity tests. The TTPA gene (ttpa) is expressed at the leading edges of the brain ventricle border. Ttpa knockdown using morpholinos is 100% lethal by 24 hpf, while E- embryo brains are often over- or under-inflated at 24 hpf. Further, E- embryos prior to 24 hpf have increased expression of genes involved in glycolysis and the pentose phosphate pathway, and decreased expression of genes involved in anabolic pathways and transcription. Combined data from both gene expression and the metabolome in E- embryos at 24 hpf suggest that the activity of the mechanistic Target of Rapamycin (mTOR) signaling pathway is decreased, which may impact both metabolism and neurodevelopment. Further evaluation of VitE deficiency in neurogenesis and its subsequent impact on learning and behavior is needed.
Collapse
Affiliation(s)
- Brian Head
- Linus Pauling Institute, Corvallis, OR, USA; Molecular and Cell Biology Program, Corvallis, OR, USA
| | - Maret G Traber
- Linus Pauling Institute, Corvallis, OR, USA; School of Biological and Population Health Sciences, College of Public Health and Human Sciences, Oregon State University, Corvallis, OR, USA.
| |
Collapse
|
37
|
Tamaddondoust RN, Wang Y, Jafarnejad SM, Graber TE, Alain T. The highs and lows of ionizing radiation and its effects on protein synthesis. Cell Signal 2021; 89:110169. [PMID: 34662715 DOI: 10.1016/j.cellsig.2021.110169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 08/19/2021] [Accepted: 10/06/2021] [Indexed: 11/03/2022]
Abstract
Ionizing radiation (IR) is a constant feature of our environment and one that can dramatically affect organismal health and development. Although the impacts of high-doses of IR on mammalian cells and systems have been broadly explored, there are still challenges in accurately quantifying biological responses to IR, especially in the low-dose range to which most individuals are exposed in their lifetime. The resulting uncertainty has led to the entrenchment of conservative radioprotection policies around the world. Thus, uncovering long-sought molecular mechanisms and tissue responses that are targeted by IR could lead to more informed policymaking and propose new therapeutic avenues for a variety of pathologies. One often overlooked target of IR is mRNA translation, a highly regulated cellular process that consumes more than 40% of the cell's energy. In response to environmental stimuli, regulation of mRNA translation allows for precise and rapid changes to the cellular proteome, and unsurprisingly high-dose of IR was shown to trigger a severe reprogramming of global protein synthesis allowing the cell to conserve energy by preventing the synthesis of unneeded proteins. Nonetheless, under these conditions, certain mRNAs encoding specific proteins are translationally favoured to produce the factors essential to repair the cell or send it down the path of no return through programmed cell death. Understanding the mechanisms controlling protein synthesis in response to varying doses of IR could provide novel insights into how this stress-mediated cellular adaptation is regulated and potentially uncover novel targets for radiosensitization or radioprotection. Here, we review the current literature on the effects of IR at both high- and low-dose on the mRNA translation machinery.
Collapse
Affiliation(s)
- Rosette Niloufar Tamaddondoust
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada; Radiobiology and Health, Canadian Nuclear Laboratories, Chalk River, Ontario, Canada.
| | - Yi Wang
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada; Radiobiology and Health, Canadian Nuclear Laboratories, Chalk River, Ontario, Canada
| | - Seyed Mehdi Jafarnejad
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast BT9 7AE, UK
| | - Tyson E Graber
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
| | - Tommy Alain
- Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada.
| |
Collapse
|
38
|
Regulation of mRNA translation in stem cells; links to brain disorders. Cell Signal 2021; 88:110166. [PMID: 34624487 DOI: 10.1016/j.cellsig.2021.110166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 08/09/2021] [Accepted: 09/29/2021] [Indexed: 11/22/2022]
Abstract
Translational control of gene expression is emerging as a cardinal step in the regulation of protein abundance. Especially for embryonic (ESC) and neuronal stem cells (NSC), regulation of mRNA translation is involved in the maintenance of pluripotency but also differentiation. For neuronal stem cells this regulation is linked to the various neuronal subtypes that arise in the developing brain and is linked to numerous brain disorders. Herein, we review translational control mechanisms in ESCs and NSCs during development and differentiation, and briefly discuss their link to brain disorders.
Collapse
|
39
|
Tuberous Sclerosis Complex (TSC) Inactivation Increases Neuronal Network Activity by Enhancing Ca 2+ Influx via L-Type Ca 2+ Channels. J Neurosci 2021; 41:8134-8149. [PMID: 34417327 DOI: 10.1523/jneurosci.1930-20.2021] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 08/09/2021] [Accepted: 08/11/2021] [Indexed: 12/19/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is a multisystem developmental disorder characterized by hamartomas in various organs, such as the brain, lungs, and kidneys. Epilepsy, along with autism and intellectual disability, is one of the neurologic impairments associated with TSC that has an intimate relationship with developmental outcomes and quality of life. Sustained activation of the mammalian target of rapamycin (mTOR) via TSC1 or TSC2 mutations is known to be involved in the onset of epilepsy in TSC. However, the mechanism by which mTOR causes seizures remains unknown. In this study, we showed that, human induced pluripotent stem cell-derived TSC2-deficient (TSC2 -/-) neurons exhibited elevated neuronal activity with highly synchronized Ca2+ spikes. Notably, TSC2 -/- neurons presented enhanced Ca2+ influx via L-type Ca2+ channels (LTCCs), which contributed to the abnormal neurite extension and sustained activation of cAMP response element binding protein (CREB), a critical mediator of synaptic plasticity. Expression of Cav1.3, a subtype of LTCCs, was increased in TSC2 -/- neurons, but long-term rapamycin treatment suppressed this increase and reversed the altered neuronal activity and neurite extensions. Thus, we identified Cav1.3 LTCC as a critical downstream component of TSC-mTOR signaling that would trigger enhanced neuronal network activity of TSC2 -/- neurons. We suggest that LTCCs could be potential novel targets for the treatment of epilepsy in TSC.SIGNIFICANCE STATEMENT There is a close relationship between elevated mammalian target of rapamycin (mTOR) activity and epilepsy in tuberous sclerosis complex (TSC). However, the underlying mechanism by which mTOR causes epilepsy remains unknown. In this study, using human TSC2 -/- neurons, we identified elevated Ca2+ influx via L-type Ca2+ channels as a critical downstream component of TSC-mTOR signaling and a potential cause of both elevated neuronal activity and neurite extension in TSC2 -/- neurons. Our findings demonstrate a previously unrecognized connection between sustained mTOR activation and elevated Ca2+ signaling via L-type Ca2+ channels in human TSC neurons, which could cause epilepsy in TSC.
Collapse
|
40
|
Klofas LK, Short BP, Zhou C, Carson RP. Prevention of premature death and seizures in a Depdc5 mouse epilepsy model through inhibition of mTORC1. Hum Mol Genet 2021; 29:1365-1377. [PMID: 32280987 DOI: 10.1093/hmg/ddaa068] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 03/31/2020] [Accepted: 04/06/2020] [Indexed: 11/13/2022] Open
Abstract
Mutations in DEP domain containing 5 (DEPDC5) are increasingly appreciated as one of the most common causes of inherited focal epilepsy. Epilepsies due to DEPDC5 mutations are often associated with brain malformations, tend to be drug-resistant, and have been linked to an increased risk of sudden unexplained death in epilepsy (SUDEP). Generation of epilepsy models to define mechanisms of epileptogenesis remains vital for future therapies. Here, we describe a novel mouse model of Depdc5 deficiency with a severe epilepsy phenotype, generated by conditional deletion of Depdc5 in dorsal telencephalic neuroprogenitor cells. In contrast to control and heterozygous mice, Depdc5-Emx1-Cre conditional knockout (CKO) mice demonstrated macrocephaly, spontaneous seizures and premature death. Consistent with increased mTORC1 activation, targeted neurons were enlarged and both neurons and astrocytes demonstrated increased S6 phosphorylation. Electrophysiologic characterization of miniature inhibitory post-synaptic currents in excitatory neurons was consistent with impaired post-synaptic response to GABAergic input, suggesting a potential mechanism for neuronal hyperexcitability. mTORC1 inhibition with rapamycin significantly improved survival of CKO animals and prevented observed seizures, including for up to 40 days following rapamycin withdrawal. These data not only support a primary role for mTORC1 hyperactivation in epilepsy following homozygous loss of Depdc5, but also suggest a developmental window for treatment which may have a durable benefit for some time even after withdrawal.
Collapse
Affiliation(s)
- Lindsay K Klofas
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA
| | - Brittany P Short
- Division of Pediatric Neurology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Chengwen Zhou
- Department of Neurology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Robert P Carson
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA.,Division of Pediatric Neurology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| |
Collapse
|
41
|
Bassetti D, Luhmann HJ, Kirischuk S. Effects of Mutations in TSC Genes on Neurodevelopment and Synaptic Transmission. Int J Mol Sci 2021; 22:ijms22147273. [PMID: 34298906 PMCID: PMC8305053 DOI: 10.3390/ijms22147273] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 07/02/2021] [Accepted: 07/04/2021] [Indexed: 12/11/2022] Open
Abstract
Mutations in TSC1 or TSC2 genes are linked to alterations in neuronal function which ultimately lead to the development of a complex neurological phenotype. Here we review current research on the effects that reduction in TSC1 or TSC2 can produce on the developing neural network. A crucial feature of the disease pathophysiology appears to be an early deviation from typical neurodevelopment, in the form of structural abnormalities. Epileptic seizures are one of the primary early manifestation of the disease in the CNS, followed by intellectual deficits and autism spectrum disorders (ASD). Research using mouse models suggests that morphological brain alterations might arise from the interaction of different cellular types, and hyperexcitability in the early postnatal period might be transient. Moreover, the increased excitation-to-inhibition ratio might represent a transient compensatory adjustment to stabilize the developing network rather than a primary factor for the development of ASD symptoms. The inhomogeneous results suggest region-specificity as well as an evolving picture of functional alterations along development. Furthermore, ASD symptoms and epilepsy might originate from different but potentially overlapping mechanisms, which can explain recent observations obtained in patients. Potential treatment is determined not only by the type of medicament, but also by the time point of treatment.
Collapse
|
42
|
Freitag CM, Chiocchetti AG, Haslinger D, Yousaf A, Waltes R. [Genetic risk factors and their influence on neural development in autism spectrum disorders]. ZEITSCHRIFT FUR KINDER-UND JUGENDPSYCHIATRIE UND PSYCHOTHERAPIE 2021; 50:187-202. [PMID: 34128703 DOI: 10.1024/1422-4917/a000803] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Genetic risk factors and their influence on neural development in autism spectrum disorders Abstract. Abstract. Autism spectrum disorders are etiologically based on genetic and specific gene x biologically relevant environmental risk factors. They are diagnosed based on behavioral characteristics, such as impaired social communication and stereotyped, repetitive behavior and sensory as well as special interests. The genetic background is heterogeneous, i. e., it comprises diverse genetic risk factors across the disorder and high interindividual differences of specific genetic risk factors. Nevertheless, risk factors converge regarding underlying biological mechanisms and shared pathways, which likely cause the autism-specific behavioral characteristics. The current selective literature review summarizes differential genetic risk factors and focuses particularly on mechanisms and pathways currently being discussed by international research. In conclusion, clinically relevant aspects and open translational research questions are presented.
Collapse
Affiliation(s)
- Christine M Freitag
- Klinik für Psychiatrie, Psychosomatik und Psychotherapie des Kindes- und Jugendalters, Universitätsklinikum Frankfurt, Goethe-Universität, Frankfurt am Main
| | - Andreas G Chiocchetti
- Klinik für Psychiatrie, Psychosomatik und Psychotherapie des Kindes- und Jugendalters, Universitätsklinikum Frankfurt, Goethe-Universität, Frankfurt am Main
| | - Denise Haslinger
- Klinik für Psychiatrie, Psychosomatik und Psychotherapie des Kindes- und Jugendalters, Universitätsklinikum Frankfurt, Goethe-Universität, Frankfurt am Main
| | - Afsheen Yousaf
- Klinik für Psychiatrie, Psychosomatik und Psychotherapie des Kindes- und Jugendalters, Universitätsklinikum Frankfurt, Goethe-Universität, Frankfurt am Main
| | - Regina Waltes
- Klinik für Psychiatrie, Psychosomatik und Psychotherapie des Kindes- und Jugendalters, Universitätsklinikum Frankfurt, Goethe-Universität, Frankfurt am Main
| |
Collapse
|
43
|
Di Napoli C, Gennaro A, Lupica C, Falsaperla R, Leonardi R, Garozzo MT, Polizzi A, Praticò AD, Zanghì A, Ruggieri M. TSC1 and TSC2: Tuberous Sclerosis Complex and Its Related Epilepsy Phenotype. JOURNAL OF PEDIATRIC NEUROLOGY 2021. [DOI: 10.1055/s-0041-1727142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
AbstractTuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by a multisystemic involvement. In TSC, reduced function of TSC1 and TSC2 genes products (hamartin and tuberin, respectively) leads to an hyperactivation of the mechanistic target of rapamycin (mTOR) pathway and to a consequent cell growth dysregulation. In TSC patients, neurological and neuropsychiatric manifestations, especially epilepsy and neuropsychiatric comorbidities such as autism or intellectual disability, represent the most disabling features. In particular, epilepsy occurrs up to 80% of patients, is often drug resistant and is frequently associated with neurological impairment. Due to the burden of this morbidity, different treatment strategies have been proposed with the purpose to make patients epilepsy free, such as the use of different antiepileptic drugs like vigabatrin, carbamazepine, valproic acid, and levetiracetam. More recently, a mTOR inhibitor (i.e. everolimus) has showed promising results in terms of seizures reduction.
Collapse
Affiliation(s)
- Claudia Di Napoli
- Postgraduate Training Program in Genetics, Department of Biomedical and Biotechnological Sciences, Section of Genetics, University of Catania, Catania, Italy
| | - Alessia Gennaro
- Postgraduate Training Program in Genetics, Department of Biomedical and Biotechnological Sciences, Section of Genetics, University of Catania, Catania, Italy
| | - Carmelania Lupica
- Postgraduate Training Program in Genetics, Department of Biomedical and Biotechnological Sciences, Section of Genetics, University of Catania, Catania, Italy
| | - Raffaele Falsaperla
- Unit of Pediatrics and Pediatric Emergency, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
- Unit of Neonatal Intenstive Care and Neonatology, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
| | - Roberta Leonardi
- Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, Unit of Rare Diseases of the Nervous System in Childhood, University of Catania, Catania, Italy
| | - Maria Teresa Garozzo
- Unit of Pediatrics and Pediatric Emergency, Hospital “Cannizzaro,” Catania, Italy
| | - Agata Polizzi
- Chair of Pediatrics, Department of Educational Sciences, University of Catania, Catania, Italy
| | - Andrea D. Praticò
- Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, Unit of Rare Diseases of the Nervous System in Childhood, University of Catania, Catania, Italy
| | - Antonio Zanghì
- Department of General Surgery and Medical-Surgical Specialty, University of Catania, Catania, Italy
| | - Martino Ruggieri
- Chair of Pediatrics, Department of Educational Sciences, University of Catania, Catania, Italy
| |
Collapse
|
44
|
Deng Y, Yang Q, Yang Y, Li Y, Peng H, Wu S, Zhang S, Yao B, Li S, Gao Y, Li X, Li L, Deng Y. Conditional knockout of Tsc1 in RORγt-expressing cells induces brain damage and early death in mice. J Neuroinflammation 2021; 18:107. [PMID: 33957945 PMCID: PMC8101034 DOI: 10.1186/s12974-021-02153-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 04/15/2021] [Indexed: 11/23/2022] Open
Abstract
Background Tuberous sclerosis complex 1 (Tsc1) is known to regulate the development and function of various cell types, and RORγt is a critical transcription factor in the immune system. However, whether Tsc1 participates in regulating RORγt-expressing cells remains unknown. Methods We generated a mouse model in which Tsc1 was conditionally deleted from RORγt-expressing cells (Tsc1RORγt) to study the role of RORγt-expressing cells with Tsc1 deficiency in brain homeostasis. Results Type 3 innate lymphoid cells (ILC3s) in Tsc1RORγt mice displayed normal development and function, and the mice showed normal Th17 cell differentiation. However, Tsc1RORγt mice exhibited spontaneous tonic-clonic seizures and died between 4 and 6 weeks after birth. At the age of 4 weeks, mice in which Tsc1 was specifically knocked out in RORγt-expressing cells had cortical neuron defects and hippocampal structural abnormalities. Notably, over-activation of neurons and astrogliosis were observed in the cortex and hippocampus of Tsc1RORγt mice. Moreover, expression of the γ-amino butyric acid (GABA) receptor in the brains of Tsc1RORγt mice was decreased, and GABA supplementation prolonged the lifespan of the mice to some extent. Further experiments revealed the presence of a group of rare RORγt-expressing cells with high metabolic activity in the mouse brain. Conclusions Our study verifies the critical role of previously unnoticed RORγt-expressing cells in the brain and demonstrates that the Tsc1 signaling pathway in RORγt-expressing cells is important for maintaining brain homeostasis. Supplementary Information The online version contains supplementary material available at 10.1186/s12974-021-02153-8.
Collapse
Affiliation(s)
- Yafei Deng
- Hunan Children's Research Institute (HCRI), Hunan Children's Hospital, Changsha, 410000, China
| | - Qinglan Yang
- Hunan Children's Research Institute (HCRI), Hunan Children's Hospital, Changsha, 410000, China
| | - Yao Yang
- Institute of Materia Medica, College of Pharmacy, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Yana Li
- Hunan Children's Research Institute (HCRI), Hunan Children's Hospital, Changsha, 410000, China
| | - Hongyan Peng
- Hunan Children's Research Institute (HCRI), Hunan Children's Hospital, Changsha, 410000, China
| | - Shuting Wu
- Hunan Children's Research Institute (HCRI), Hunan Children's Hospital, Changsha, 410000, China
| | - Shuju Zhang
- Hunan Children's Research Institute (HCRI), Hunan Children's Hospital, Changsha, 410000, China
| | - Baige Yao
- Department of Pharmacy, The Third Xiangya Hospital, Central South University, Changsha, 410000, China
| | - Shuhui Li
- Department of Clinical Biochemistry, Faculty of Pharmacy and Laboratory Medicine, Army Medical University (Third Military Medical University), Chongqing, 400038, China
| | - Yuan Gao
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing, 400038, China
| | - Xiaohui Li
- Institute of Materia Medica, College of Pharmacy, Army Medical University (Third Military Medical University), Chongqing, 400038, China.
| | - Liping Li
- Hunan Children's Research Institute (HCRI), Hunan Children's Hospital, Changsha, 410000, China.
| | - Youcai Deng
- Institute of Materia Medica, College of Pharmacy, Army Medical University (Third Military Medical University), Chongqing, 400038, China.
| |
Collapse
|
45
|
Terrey M, Adamson SI, Chuang JH, Ackerman SL. Defects in translation-dependent quality control pathways lead to convergent molecular and neurodevelopmental pathology. eLife 2021; 10:e66904. [PMID: 33899734 PMCID: PMC8075583 DOI: 10.7554/elife.66904] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/05/2021] [Indexed: 12/27/2022] Open
Abstract
Translation-dependent quality control pathways such as no-go decay (NGD), non-stop decay (NSD), and nonsense-mediated decay (NMD) govern protein synthesis and proteostasis by resolving non-translating ribosomes and preventing the production of potentially toxic peptides derived from faulty and aberrant mRNAs. However, how translation is altered and the in vivo defects that arise in the absence of these pathways are poorly understood. Here, we show that the NGD/NSD factors Pelo and Hbs1l are critical in mice for cerebellar neurogenesis but expendable for survival of these neurons after development. Analysis of mutant mouse embryonic fibroblasts revealed translational pauses, alteration of signaling pathways, and translational reprogramming. Similar effects on signaling pathways, including mTOR activation, the translatome and mouse cerebellar development were observed upon deletion of the NMD factor Upf2. Our data reveal that these quality control pathways that function to mitigate errors at distinct steps in translation can evoke similar cellular responses.
Collapse
Affiliation(s)
- Markus Terrey
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, Section of Neurobiology, Division of Biological Sciences, University of California San DiegoLa JollaUnited States
- Graduate School of Biomedical Sciences and Engineering, University of MaineOronoUnited States
| | - Scott I Adamson
- The Jackson Laboratory for Genomic MedicineFarmingtonUnited States
- Department of Genetics and Genome Sciences, Institute for Systems Genomics, UConn HealthFarmingtonUnited States
| | - Jeffrey H Chuang
- The Jackson Laboratory for Genomic MedicineFarmingtonUnited States
- Department of Genetics and Genome Sciences, Institute for Systems Genomics, UConn HealthFarmingtonUnited States
| | - Susan L Ackerman
- Howard Hughes Medical Institute, Department of Cellular and Molecular Medicine, Section of Neurobiology, Division of Biological Sciences, University of California San DiegoLa JollaUnited States
| |
Collapse
|
46
|
Tang X, Angst G, Haas M, Yang F, Wang C. The Characterization of a Subependymal Giant Astrocytoma-Like Cell Line from Murine Astrocyte with mTORC1 Hyperactivation. Int J Mol Sci 2021; 22:ijms22084116. [PMID: 33923449 PMCID: PMC8074262 DOI: 10.3390/ijms22084116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/07/2021] [Accepted: 04/13/2021] [Indexed: 11/16/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is a genetic disorder caused by inactivating mutations in TSC1 (hamartin) or TSC2 (tuberin), crucial negative regulators of the mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway. TSC affects multiple organs including the brain. The neurologic manifestation is characterized by cortical tubers, subependymal nodules (SEN), and subependymal giant cell astrocytoma (SEGA) in brain. SEGAs may result in hydrocephalus in TSC patients and mTORC1 inhibitors are the current recommended therapy for SEGA. Nevertheless, a major limitation in the research for SEGA is the lack of cell lines or animal models for mechanistic investigations and development of novel therapy. In this study, we generated TSC1-deficient neural cells from spontaneously immortalized mouse astrocytes in an attempt to mimic human SEGA. The TSC1-deficient cells exhibit mTORC1 hyperactivation and characteristics of transition from astrocytes to neural stem/progenitor cell phenotypes. Rapamycin efficiently decreased mTORC1 activity of these TSC1-deficient cells in vitro. In vivo, TSC1-deficient cells could form SEGA-like tumors and Rapamycin treatment decreased tumor growth. Collectively, our study generates a novel SEGA-like cell line that is invaluable for studying mTORC1-driven molecular and pathological alterations in neurologic tissue. These SEGA-like cells also provide opportunities for the development of novel therapeutic strategy for TSC patients with SEGA.
Collapse
|
47
|
Scaramuzza L, De Rocco G, Desiato G, Cobolli Gigli C, Chiacchiaretta M, Mirabella F, Pozzi D, De Simone M, Conforti P, Pagani M, Benfenati F, Cesca F, Bedogni F, Landsberger N. The enhancement of activity rescues the establishment of Mecp2 null neuronal phenotypes. EMBO Mol Med 2021; 13:e12433. [PMID: 33665914 PMCID: PMC8033520 DOI: 10.15252/emmm.202012433] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 01/24/2021] [Accepted: 01/27/2021] [Indexed: 01/29/2023] Open
Abstract
MECP2 mutations cause Rett syndrome (RTT), a severe and progressive neurodevelopmental disorder mainly affecting females. Although RTT patients exhibit delayed onset of symptoms, several evidences demonstrate that MeCP2 deficiency alters early development of the brain. Indeed, during early maturation, Mecp2 null cortical neurons display widespread transcriptional changes, reduced activity, and defective morphology. It has been proposed that during brain development these elements are linked in a feed-forward cycle where neuronal activity drives transcriptional and morphological changes that further increase network maturity. We hypothesized that the enhancement of neuronal activity during early maturation might prevent the onset of RTT-typical molecular and cellular phenotypes. Accordingly, we show that the enhancement of excitability, obtained by adding to neuronal cultures Ampakine CX546, rescues transcription of several genes, neuronal morphology, and responsiveness to stimuli. Greater effects are achieved in response to earlier treatments. In vivo, short and early administration of CX546 to Mecp2 null mice prolongs lifespan, delays the disease progression, and rescues motor abilities and spatial memory, thus confirming the value for RTT of an early restoration of neuronal activity.
Collapse
Affiliation(s)
- Linda Scaramuzza
- Division of NeuroscienceIRCCS San Raffaele Scientific InstituteMilanItaly
- Present address:
Department of Bioscience, University of Milan, Milan, Italy; Istituto Nazionale Genetica Molecolare “Romeo ed Enrica Invernizzi”MilanItaly
| | - Giuseppina De Rocco
- Division of NeuroscienceIRCCS San Raffaele Scientific InstituteMilanItaly
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanMilanItaly
| | - Genni Desiato
- IRCCS Humanitas Research HospitalMilanItaly
- CNR Institute of NeuroscienceMilanItaly
| | - Clementina Cobolli Gigli
- Division of NeuroscienceIRCCS San Raffaele Scientific InstituteMilanItaly
- Present address:
Francis Crick InstituteLondonUK
| | - Martina Chiacchiaretta
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di TecnologiaGenovaItaly
- Present address:
Department of NeuroscienceTufts University School of MedicineBostonMAUSA
| | - Filippo Mirabella
- IRCCS Humanitas Research HospitalMilanItaly
- Department of Biomedical Sciences, Humanitas UniversityMilanItaly
| | - Davide Pozzi
- IRCCS Humanitas Research HospitalMilanItaly
- Department of Biomedical Sciences, Humanitas UniversityMilanItaly
| | - Marco De Simone
- Istituto Nazionale Genetica Molecolare “Romeo ed Enrica Invernizzi”MilanItaly
- Present address:
Department of Radiation Oncology, Cedars-Sinai Medical CenterLos Angeles, CAUSA
| | - Paola Conforti
- Istituto Nazionale Genetica Molecolare “Romeo ed Enrica Invernizzi”MilanItaly
- Department of BiosciencesUniversity of MilanMilanItaly
| | - Massimiliano Pagani
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanMilanItaly
- Istituto Nazionale Genetica Molecolare “Romeo ed Enrica Invernizzi”MilanItaly
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di TecnologiaGenovaItaly
- IRCCS Ospedale Policlinico San MartinoGenovaItaly
- Present address:
Francis Crick InstituteLondonUK
| | - Fabrizia Cesca
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di TecnologiaGenovaItaly
- Department of Life SciencesUniversity of TriesteTriesteItaly
- Present address:
Department of Radiation Oncology, Cedars-Sinai Medical CenterLos Angeles, CAUSA
| | - Francesco Bedogni
- Division of NeuroscienceIRCCS San Raffaele Scientific InstituteMilanItaly
- Present address:
Neuroscience and Mental Health Research Institute (NMHRI)Division of NeuroscienceSchool of BiosciencesCardiffUK
| | - Nicoletta Landsberger
- Division of NeuroscienceIRCCS San Raffaele Scientific InstituteMilanItaly
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanMilanItaly
| |
Collapse
|
48
|
Nguyen LH, Bordey A. Convergent and Divergent Mechanisms of Epileptogenesis in mTORopathies. Front Neuroanat 2021; 15:664695. [PMID: 33897381 PMCID: PMC8064518 DOI: 10.3389/fnana.2021.664695] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 03/17/2021] [Indexed: 12/30/2022] Open
Abstract
Hyperactivation of the mechanistic target of rapamycin complex 1 (mTORC1) due to mutations in genes along the PI3K-mTOR pathway and the GATOR1 complex causes a spectrum of neurodevelopmental disorders (termed mTORopathies) associated with malformation of cortical development and intractable epilepsy. Despite these gene variants’ converging impact on mTORC1 activity, emerging findings suggest that these variants contribute to epilepsy through both mTORC1-dependent and -independent mechanisms. Here, we review the literature on in utero electroporation-based animal models of mTORopathies, which recapitulate the brain mosaic pattern of mTORC1 hyperactivity, and compare the effects of distinct PI3K-mTOR pathway and GATOR1 complex gene variants on cortical development and epilepsy. We report the outcomes on cortical pyramidal neuronal placement, morphology, and electrophysiological phenotypes, and discuss some of the converging and diverging mechanisms responsible for these alterations and their contribution to epileptogenesis. We also discuss potential therapeutic strategies for epilepsy, beyond mTORC1 inhibition with rapamycin or everolimus, that could offer personalized medicine based on the gene variant.
Collapse
Affiliation(s)
- Lena H Nguyen
- Department of Neurosurgery, Yale School of Medicine, Yale University, New Haven, CT, United States.,Department of Cellular & Molecular Physiology, Yale School of Medicine, Yale University, New Haven, CT, United States
| | - Angélique Bordey
- Department of Neurosurgery, Yale School of Medicine, Yale University, New Haven, CT, United States.,Department of Cellular & Molecular Physiology, Yale School of Medicine, Yale University, New Haven, CT, United States
| |
Collapse
|
49
|
Calabrò M, Rinaldi C, Santoro G, Crisafulli C. The biological pathways of Alzheimer disease: a review. AIMS Neurosci 2020; 8:86-132. [PMID: 33490374 PMCID: PMC7815481 DOI: 10.3934/neuroscience.2021005] [Citation(s) in RCA: 90] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 11/23/2020] [Indexed: 12/18/2022] Open
Abstract
Alzheimer disease is a progressive neurodegenerative disorder, mainly affecting older people, which severely impairs patients' quality of life. In the recent years, the number of affected individuals has seen a rapid increase. It is estimated that up to 107 million subjects will be affected by 2050 worldwide. Research in this area has revealed a lot about the biological and environmental underpinnings of Alzheimer, especially its correlation with β-Amyloid and Tau related mechanics; however, the precise molecular events and biological pathways behind the disease are yet to be discovered. In this review, we focus our attention on the biological mechanics that may lie behind Alzheimer development. In particular, we briefly describe the genetic elements and discuss about specific biological processes potentially associated with the disease.
Collapse
Affiliation(s)
| | | | | | - Concetta Crisafulli
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Italy
| |
Collapse
|
50
|
Abstract
Purpose of Review Diet has profound impacts on health and longevity. Evidence is emerging to suggest that diet impinges upon the metabolic pathways in tissue-specific stem cells to influence health and disease. Here, we review the similarities and differences in the metabolism of stem cells from several tissues, and highlight the mitochondrial metabolic checkpoint in stem cell maintenance and aging. We discuss how diet engages the nutrient sensing metabolic pathways and impacts stem cell maintenance. Finally, we explore the therapeutic implications of dietary and metabolic regulation of stem cells. Recent findings Stem Cell transition from quiescence to proliferation is associated with a metabolic switch from glycolysis to mitochondrial OXPHOS and the mitochondrial metabolic checkpoint is critically controlled by the nutrient sensors SIRT2, SIRT3, and SIRT7 in hematopoietic stem cells. Intestine stem cell homeostasis during aging and in response to diet is critically dependent on fatty acid metabolism and ketone bodies and is influenced by the niche mediated by the nutrient sensor mTOR. Summary Nutrient sensing metabolic pathways critically regulate stem cell maintenance during aging and in response to diet. Elucidating the molecular mechanisms underlying dietary and metabolic regulation of stem cells provides novel insights for stem cell biology and may be targeted therapeutically to reverse stem cell aging and tissue degeneration.
Collapse
|