1
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Guo D, Han L, Godale CM, Rensing NR, Danzer SC, Wong M. A role of dentate gyrus mechanistic target of rapamycin activation in epileptogenesis in a mouse model of posttraumatic epilepsy. Epilepsia 2024; 65:2127-2137. [PMID: 38761065 PMCID: PMC11251851 DOI: 10.1111/epi.18011] [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: 01/28/2024] [Revised: 04/30/2024] [Accepted: 04/30/2024] [Indexed: 05/20/2024]
Abstract
OBJECTIVE The mechanistic target of rapamycin (mTOR) pathway has been implicated in promoting epileptogenesis in animal models of acquired epilepsy, such as posttraumatic epilepsy (PTE) following traumatic brain injury (TBI). However, the specific anatomical regions and neuronal populations mediating mTOR's role in epileptogenesis are not well defined. In this study, we tested the hypothesis that mTOR activation in dentate gyrus granule cells promotes neuronal death, mossy fiber sprouting, and PTE in the controlled cortical impact (CCI) model of TBI. METHODS An adeno-associated virus (AAV)-Cre viral vector was injected into the hippocampus of Rptorflox/flox (regulatory-associated protein of mTOR) mutant mice to inhibit mTOR activation in dentate gyrus granule cells. Four weeks after AAV-Cre or AAV-vehicle injection, mice underwent CCI injury and were subsequently assessed for mTOR pathway activation by Western blotting, neuronal death, and mossy fiber sprouting by immunopathological analysis, and posttraumatic seizures by video-electroencephalographic monitoring. RESULTS AAV-Cre injection primarily affected the dentate gyrus and inhibited hippocampal mTOR activation following CCI injury. AAV-Cre-injected mice had reduced neuronal death in dentate gyrus detected by Fluoro-Jade B staining and decreased mossy fiber sprouting by ZnT3 immunostaining. Finally, AAV-Cre-injected mice exhibited a decrease in incidence of PTE. SIGNIFICANCE mTOR pathway activation in dentate gyrus granule cells may at least partly mediate pathological abnormalities and epileptogenesis in models of TBI and PTE. Targeted modulation of mTOR activity in this hippocampal network may represent a focused therapeutic approach for antiepileptogenesis and prevention of PTE.
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Affiliation(s)
- Dongjun Guo
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, USA 63110
| | - Lirong Han
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, USA 63110
| | - Christin M. Godale
- Department of Anesthesia, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229
| | - Nicholas R. Rensing
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, USA 63110
| | - Steve C. Danzer
- Department of Anesthesia, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229
| | - Michael Wong
- Department of Neurology and the Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, USA 63110
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2
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Dhaliwal NK, Weng OY, Dong X, Bhattacharya A, Ahmed M, Nishimura H, Choi WWY, Aggarwal A, Luikart BW, Shu Q, Li X, Wilson MD, Moffat J, Wang LY, Muffat J, Li Y. Synergistic hyperactivation of both mTORC1 and mTORC2 underlies the neural abnormalities of PTEN-deficient human neurons and cortical organoids. Cell Rep 2024; 43:114173. [PMID: 38700984 DOI: 10.1016/j.celrep.2024.114173] [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: 09/22/2023] [Revised: 03/20/2024] [Accepted: 04/16/2024] [Indexed: 05/05/2024] Open
Abstract
Mutations in the phosphatase and tensin homolog (PTEN) gene are associated with severe neurodevelopmental disorders. Loss of PTEN leads to hyperactivation of the mechanistic target of rapamycin (mTOR), which functions in two distinct protein complexes, mTORC1 and mTORC2. The downstream signaling mechanisms that contribute to PTEN mutant phenotypes are not well delineated. Here, we show that pluripotent stem cell-derived PTEN mutant human neurons, neural precursors, and cortical organoids recapitulate disease-relevant phenotypes, including hypertrophy, electrical hyperactivity, enhanced proliferation, and structural overgrowth. PTEN loss leads to simultaneous hyperactivation of mTORC1 and mTORC2. We dissect the contribution of mTORC1 and mTORC2 by generating double mutants of PTEN and RPTOR or RICTOR, respectively. Our results reveal that the synergistic hyperactivation of both mTORC1 and mTORC2 is essential for the PTEN mutant human neural phenotypes. Together, our findings provide insights into the molecular mechanisms that underlie PTEN-related neural disorders and highlight novel therapeutic targets.
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Affiliation(s)
- Navroop K Dhaliwal
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Octavia Yifang Weng
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Program in Neurosciences and Mental Health, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Physiology, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Xiaoxue Dong
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; The Children's Hospital, National Clinical Research Center for Child Health, School of Medicine, Zhejiang University, Hangzhou 310052, China; The Institute of Translational Medicine, School of Medicine, Zhejiang University, Hangzhou 310029, China
| | - Afrin Bhattacharya
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Mai Ahmed
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Haruka Nishimura
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Wendy W Y Choi
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada; Program in Genetics and Genome Biology, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Aditi Aggarwal
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Bryan W Luikart
- Department of Molecular and Systems Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH 03755, USA
| | - Qiang Shu
- The Children's Hospital, National Clinical Research Center for Child Health, School of Medicine, Zhejiang University, Hangzhou 310052, China
| | - Xuekun Li
- The Children's Hospital, National Clinical Research Center for Child Health, School of Medicine, Zhejiang University, Hangzhou 310052, China; The Institute of Translational Medicine, School of Medicine, Zhejiang University, Hangzhou 310029, China
| | - Michael D Wilson
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada; Program in Genetics and Genome Biology, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Jason Moffat
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada; Program in Genetics and Genome Biology, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Lu-Yang Wang
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Physiology, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Julien Muffat
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Yun Li
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada.
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3
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Meng J, Zhang L, Zhang YW. Microglial Dysfunction in Autism Spectrum Disorder. Neuroscientist 2024:10738584241252576. [PMID: 38712859 DOI: 10.1177/10738584241252576] [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: 05/08/2024]
Abstract
Autism spectrum disorder (ASD) is a highly heterogeneous neurodevelopmental disorder with onset in childhood. The molecular mechanisms underlying ASD have not yet been elucidated completely. Evidence has emerged to support a link between microglial dysfunction and the etiology of ASD. This review summarizes current research on microglial dysfunction in neuroinflammation and synaptic pruning, which are associated with altered transcriptomes and autophagy in ASD. Dysbiosis of gut microbiota in ASD and its correlation with microglial dysfunction are also addressed.
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Affiliation(s)
- Jian Meng
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
- Xiamen Key Laboratory of Brain Center, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
| | - Lingliang Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
- Xiamen Key Laboratory of Brain Center, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
| | - Yun-Wu Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
- Xiamen Key Laboratory of Brain Center, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
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4
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Cullen ER, Safari M, Mittelstadt I, Weston MC. Hyperactivity of mTORC1- and mTORC2-dependent signaling mediates epilepsy downstream of somatic PTEN loss. eLife 2024; 12:RP91323. [PMID: 38446016 PMCID: PMC10942640 DOI: 10.7554/elife.91323] [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] [Indexed: 03/07/2024] Open
Abstract
Gene variants that hyperactivate PI3K-mTOR signaling in the brain lead to epilepsy and cortical malformations in humans. Some gene variants associated with these pathologies only hyperactivate mTORC1, but others, such as PTEN, PIK3CA, and AKT, hyperactivate both mTORC1- and mTORC2-dependent signaling. Previous work established a key role for mTORC1 hyperactivity in mTORopathies, however, whether mTORC2 hyperactivity contributes is not clear. To test this, we inactivated mTORC1 and/or mTORC2 downstream of early Pten deletion in a new mouse model of somatic Pten loss-of-function (LOF) in the cortex and hippocampus. Spontaneous seizures and epileptiform activity persisted despite mTORC1 or mTORC2 inactivation alone, but inactivating both mTORC1 and mTORC2 simultaneously normalized brain activity. These results suggest that hyperactivity of both mTORC1 and mTORC2 can cause epilepsy, and that targeted therapies should aim to reduce activity of both complexes.
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Affiliation(s)
- Erin R Cullen
- Department of Neurological Sciences, Larner College of Medicine, University of VermontBurlingtonUnited States
| | - Mona Safari
- Fralin Biomedical Research Institute at VTC, Center for Neurobiology ResearchRoanokeUnited States
- Translational Biology, Medicine, and Health Graduate ProgramRoanokeUnited States
| | - Isabelle Mittelstadt
- Department of Neurological Sciences, Larner College of Medicine, University of VermontBurlingtonUnited States
| | - Matthew C Weston
- Department of Neurological Sciences, Larner College of Medicine, University of VermontBurlingtonUnited States
- Fralin Biomedical Research Institute at VTC, Center for Neurobiology ResearchRoanokeUnited States
- School of Neuroscience, Virginia Polytechnic and State UniversityBlacksburgUnited States
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5
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Packer JM, Bray CE, Beckman NB, Wangler LM, Davis AC, Goodman EJ, Klingele NE, Godbout JP. Impaired cortical neuronal homeostasis and cognition after diffuse traumatic brain injury are dependent on microglia and type I interferon responses. Glia 2024; 72:300-321. [PMID: 37937831 PMCID: PMC10764078 DOI: 10.1002/glia.24475] [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: 06/08/2023] [Revised: 09/14/2023] [Accepted: 09/20/2023] [Indexed: 11/09/2023]
Abstract
Neuropsychiatric complications including depression and cognitive decline develop in the years after traumatic brain injury (TBI), negatively affecting quality of life. Microglial and type 1 interferon (IFN-I) responses are associated with the transition from acute to chronic neuroinflammation after diffuse TBI in mice. Thus, the purpose of this study was to determine if impaired neuronal homeostasis and increased IFN-I responses intersected after TBI to cause cognitive impairment. Here, the RNA profile of neurons and microglia after TBI (single nucleus RNA-sequencing) with or without microglia depletion (CSF1R antagonist) was assessed 7 dpi. There was a TBI-dependent suppression of cortical neuronal homeostasis with reductions in CREB signaling, synaptogenesis, and synaptic migration and increases in RhoGDI and PTEN signaling (Ingenuity Pathway Analysis). Microglial depletion reversed 50% of TBI-induced gene changes in cortical neurons depending on subtype. Moreover, the microglial RNA signature 7 dpi was associated with increased stimulator of interferon genes (STING) activation and IFN-I responses. Therefore, we sought to reduce IFN-I signaling after TBI using STING knockout mice and a STING antagonist, chloroquine (CQ). TBI-associated cognitive deficits in novel object location and recognition (NOL/NOR) tasks at 7 and 30 dpi were STING dependent. In addition, TBI-induced STING expression, microglial morphological restructuring, inflammatory (Tnf, Cd68, Ccl2) and IFN-related (Irf3, Irf7, Ifi27) gene expression in the cortex were attenuated in STINGKO mice. CQ also reversed TBI-induced cognitive deficits and reduced TBI-induced inflammatory (Tnf, Cd68, Ccl2) and IFN (Irf7, Sting) cortical gene expression. Collectively, reducing IFN-I signaling after TBI with STING-dependent interventions attenuated the prolonged microglial activation and cognitive impairment.
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Affiliation(s)
- Jonathan M Packer
- Department of Neuroscience, The Ohio State University, Columbus, Ohio, USA
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, Ohio, USA
| | - Chelsea E Bray
- College of Medicine, The Ohio State University, Columbus, United States
| | - Nicolas B Beckman
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, Ohio, USA
| | - Lynde M Wangler
- Department of Neuroscience, The Ohio State University, Columbus, Ohio, USA
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, Ohio, USA
| | - Amara C Davis
- Department of Neuroscience, The Ohio State University, Columbus, Ohio, USA
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, Ohio, USA
| | - Ethan J Goodman
- Department of Neuroscience, The Ohio State University, Columbus, Ohio, USA
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, Ohio, USA
| | - Nathaniel E Klingele
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, Ohio, USA
| | - Jonathan P Godbout
- Department of Neuroscience, The Ohio State University, Columbus, Ohio, USA
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, Ohio, USA
- College of Medicine, The Ohio State University, Columbus, United States
- Chronic Brain Injury Program, The Ohio State University, Columbus, Ohio, USA
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6
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Goldberg AR, Dovas A, Torres D, Sharma SD, Mela A, Merricks EM, Olabarria M, Shokooh LA, Zhao HT, Kotidis C, Calvaresi P, Viswanathan A, Banu MA, Razavilar A, Sudhakar TD, Saxena A, Chokran C, Humala N, Mahajan A, Xu W, Metz JB, Chen C, Bushong EA, Boassa D, Ellisman MH, Hillman EMC, McKhann GM, Gill BJA, Rosenfeld SS, Schevon CA, Bruce JN, Sims PA, Peterka DS, Canoll P. Glioma-Induced Alterations in Excitatory Neurons are Reversed by mTOR Inhibition. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.10.575092. [PMID: 38293120 PMCID: PMC10827113 DOI: 10.1101/2024.01.10.575092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Gliomas are highly aggressive brain tumors characterized by poor prognosis and composed of diffusely infiltrating tumor cells that intermingle with non-neoplastic cells in the tumor microenvironment, including neurons. Neurons are increasingly appreciated as important reactive components of the glioma microenvironment, due to their role in causing hallmark glioma symptoms, such as cognitive deficits and seizures, as well as their potential ability to drive glioma progression. Separately, mTOR signaling has been shown to have pleiotropic effects in the brain tumor microenvironment, including regulation of neuronal hyperexcitability. However, the local cellular-level effects of mTOR inhibition on glioma-induced neuronal alterations are not well understood. Here we employed neuron-specific profiling of ribosome-bound mRNA via 'RiboTag,' morphometric analysis of dendritic spines, and in vivo calcium imaging, along with pharmacological mTOR inhibition to investigate the impact of glioma burden and mTOR inhibition on these neuronal alterations. The RiboTag analysis of tumor-associated excitatory neurons showed a downregulation of transcripts encoding excitatory and inhibitory postsynaptic proteins and dendritic spine development, and an upregulation of transcripts encoding cytoskeletal proteins involved in dendritic spine turnover. Light and electron microscopy of tumor-associated excitatory neurons demonstrated marked decreases in dendritic spine density. In vivo two-photon calcium imaging in tumor-associated excitatory neurons revealed progressive alterations in neuronal activity, both at the population and single-neuron level, throughout tumor growth. This in vivo calcium imaging also revealed altered stimulus-evoked somatic calcium events, with changes in event rate, size, and temporal alignment to stimulus, which was most pronounced in neurons with high-tumor burden. A single acute dose of AZD8055, a combined mTORC1/2 inhibitor, reversed the glioma-induced alterations on the excitatory neurons, including the alterations in ribosome-bound transcripts, dendritic spine density, and stimulus evoked responses seen by calcium imaging. These results point to mTOR-driven pathological plasticity in neurons at the infiltrative margin of glioma - manifested by alterations in ribosome-bound mRNA, dendritic spine density, and stimulus-evoked neuronal activity. Collectively, our work identifies the pathological changes that tumor-associated excitatory neurons experience as both hyperlocal and reversible under the influence of mTOR inhibition, providing a foundation for developing therapies targeting neuronal signaling in glioma.
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Affiliation(s)
- Alexander R Goldberg
- Department of Pathology and Cell Biology, Irving Cancer Research Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Athanassios Dovas
- Department of Pathology and Cell Biology, Irving Cancer Research Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Daniela Torres
- Department of Pathology and Cell Biology, Irving Cancer Research Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Sohani Das Sharma
- Department of Systems Biology, Columbia University Irving Medical Center, New York, NY 10032
| | - Angeliki Mela
- Department of Pathology and Cell Biology, Irving Cancer Research Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Edward M Merricks
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Markel Olabarria
- Department of Pathology and Cell Biology, Irving Cancer Research Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | | | - Hanzhi T Zhao
- Laboratory for Functional Optical Imaging, Zuckerman Mind Brain Behavior Institute, Departments of Biomedical Engineering and Radiology, Columbia University, New York, NY 10027, USA
| | - Corina Kotidis
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Peter Calvaresi
- Department of Pathology and Cell Biology, Irving Cancer Research Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Ashwin Viswanathan
- Department of Pathology and Cell Biology, Irving Cancer Research Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Matei A Banu
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Aida Razavilar
- Department of Pathology and Cell Biology, Irving Cancer Research Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Tejaswi D Sudhakar
- Department of Pathology and Cell Biology, Irving Cancer Research Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Ankita Saxena
- Department of Pathology and Cell Biology, Irving Cancer Research Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Cole Chokran
- Department of Pathology and Cell Biology, Irving Cancer Research Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Nelson Humala
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Aayushi Mahajan
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Weihao Xu
- Laboratory for Functional Optical Imaging, Zuckerman Mind Brain Behavior Institute, Departments of Biomedical Engineering and Radiology, Columbia University, New York, NY 10027, USA
| | - Jordan B Metz
- Department of Systems Biology, Columbia University Irving Medical Center, New York, NY 10032
| | - Cady Chen
- Department of Pathology and Cell Biology, Irving Cancer Research Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Eric A Bushong
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Daniela Boassa
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Mark H Ellisman
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Elizabeth M C Hillman
- Laboratory for Functional Optical Imaging, Zuckerman Mind Brain Behavior Institute, Departments of Biomedical Engineering and Radiology, Columbia University, New York, NY 10027, USA
| | - Guy M McKhann
- Department of Neurological Surgery, 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
| | | | - Catherine A Schevon
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Jeffrey N Bruce
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Peter A Sims
- Department of Systems Biology, Columbia University Irving Medical Center, New York, NY 10032
- Sulzberger Columbia Genome Center, Columbia University Irving Medical Center, New York, NY, 10032
- Department of Biochemistry & Molecular Biophysics, Columbia University Irving Medical Center, New York, NY, 10032
| | - Darcy S Peterka
- Irving Institute for Cancer Dynamics, Columbia University, New York, NY 10027, USA
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Peter Canoll
- Department of Pathology and Cell Biology, Irving Cancer Research Center, Columbia University Irving Medical Center, New York, NY 10032, USA
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
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7
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Cullen ER, Safari M, Mittelstadt I, Weston MC. Hyperactivity of mTORC1 and mTORC2-dependent signaling mediate epilepsy downstream of somatic PTEN loss. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.18.553856. [PMID: 37645923 PMCID: PMC10462128 DOI: 10.1101/2023.08.18.553856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Gene variants that hyperactivate PI3K-mTOR signaling in the brain lead to epilepsy and cortical malformations in humans. Some gene variants associated with these pathologies only hyperactivate mTORC1, but others, such as PTEN, PIK3CA, and AKT, hyperactivate both mTORC1- and mTORC2-dependent signaling. Previous work established a key role for mTORC1 hyperactivity in mTORopathies, however, whether mTORC2 hyperactivity contributes is not clear. To test this, we inactivated mTORC1 and/or mTORC2 downstream of early Pten deletion in a new model of somatic Pten loss-of-function (LOF) in the cortex and hippocampus. Spontaneous seizures and epileptiform activity persisted despite mTORC1 or mTORC2 inactivation alone, but inactivating both mTORC1 and mTORC2 simultaneously normalized brain activity. These results suggest that hyperactivity of both mTORC1 and mTORC2 can cause epilepsy, and that targeted therapies should aim to reduce activity of both complexes.
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Affiliation(s)
- Erin R. Cullen
- Department of Neurological Sciences, Larner College of Medicine, University of Vermont, Burlington VT, 05405, USA
| | - Mona Safari
- Fralin Biomedical Research Institute at VTC, Center for Neurobiology Research, Roanoke VA, 24016, USA
| | - Isabelle Mittelstadt
- Department of Neurological Sciences, Larner College of Medicine, University of Vermont, Burlington VT, 05405, USA
| | - Matthew C. Weston
- Department of Neurological Sciences, Larner College of Medicine, University of Vermont, Burlington VT, 05405, USA
- Fralin Biomedical Research Institute at VTC, Center for Neurobiology Research, Roanoke VA, 24016, USA
- School of Neuroscience, Virginia Polytechnic and State University, Blacksburg VA, 24060, USA
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8
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Pedini G, Chen CL, Achsel T, Bagni C. Cancer drug repurposing in autism spectrum disorder. Trends Pharmacol Sci 2023; 44:963-977. [PMID: 37940430 DOI: 10.1016/j.tips.2023.09.008] [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: 08/24/2023] [Revised: 09/20/2023] [Accepted: 09/20/2023] [Indexed: 11/10/2023]
Abstract
Autism spectrum disorder (ASD) is a complex neurodevelopmental condition with uncertain origins. Understanding of the mechanisms underlying ASD remains limited, and treatments are lacking. Genetic diversity complicates drug development. Given the complexity and severity of ASD symptoms and the rising number of diagnoses, exploring novel therapeutic strategies is essential. Here, we focus on shared molecular pathways between ASD and cancer and highlight recent progress on the repurposing of cancer drugs for ASD treatment, such as mTOR inhibitors, histone deacetylase inhibitors, and anti-inflammatory agents. We discuss how to improve trial design considering drug dose and patient age. Lastly, the discussion explores the critical aspects of side effects, commercial factors, and the efficiency of drug-screening pipelines; all of which are essential considerations in the pursuit of repurposing cancer drugs for addressing core features of ASD.
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Affiliation(s)
- Giorgia Pedini
- University of Rome Tor Vergata, Department of Biomedicine and Prevention, Via Montpellier 1, 00133, Rome, Italy
| | - Chin-Lin Chen
- University of Lausanne, Department of Fundamental Neurosciences, Rue du Bugnon 9, 1005, Lausanne, Switzerland
| | - Tilmann Achsel
- University of Lausanne, Department of Fundamental Neurosciences, Rue du Bugnon 9, 1005, Lausanne, Switzerland
| | - Claudia Bagni
- University of Rome Tor Vergata, Department of Biomedicine and Prevention, Via Montpellier 1, 00133, Rome, Italy; University of Lausanne, Department of Fundamental Neurosciences, Rue du Bugnon 9, 1005, Lausanne, Switzerland.
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9
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Nguyen LH, Sharma M, Bordey A. 4E-BP1 expression in embryonic postmitotic neurons mitigates mTORC1-induced cortical malformations and behavioral seizure severity but does not prevent epilepsy in mice. Front Neurosci 2023; 17:1257056. [PMID: 37680968 PMCID: PMC10480503 DOI: 10.3389/fnins.2023.1257056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 07/31/2023] [Indexed: 09/09/2023] Open
Abstract
Hyperactivation of the mechanistic target of rapamycin complex 1 (mTORC1) pathway during neurodevelopment leads to focal cortical malformations associated with intractable seizures. Recent evidence suggests that dysregulated cap-dependent translation downstream of mTORC1 contributes to cytoarchitectural abnormalities and seizure activity. Here, we examined whether reducing cap-dependent translation by expressing a constitutively active form of the translational repressor, 4E-BP1, downstream of mTORC1 would prevent the development of cortical malformations and seizures. 4E-BP1CA was expressed embryonically either in radial glia (neural progenitor cells) that generate cortical layer 2/3 pyramidal neurons or in migrating neurons destined to layer 2/3 using a conditional expression system. In both conditions, 4E-BP1CA expression reduced mTORC1-induced neuronal hypertrophy and alleviated cortical mislamination, but a subset of ectopic neurons persisted in the deep layers and the white matter. Despite the above improvements, 4E-BP1CA expression in radial glia had no effects on seizure frequency and further exacerbated behavioral seizure severity associated with mTORC1 hyperactivation. In contrast, conditional 4E-BP1CA expression in migratory neurons mitigated the severity of behavioral seizures but the seizure frequency remained unchanged. These findings advise against targeting 4E-BPs by 4E-BP1CA expression during embryonic development for seizure prevention and suggest the presence of a development-dependent role for 4E-BPs in mTORC1-induced epilepsy.
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Affiliation(s)
- Lena H. Nguyen
- Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, United States
- Departments of Neurosurgery and Cellular & Molecular Physiology, Wu Tsai Institute, Yale University School of Medicine, New Haven, CT, United States
| | - Manas Sharma
- Departments of Neurosurgery and Cellular & Molecular Physiology, Wu Tsai Institute, Yale University School of Medicine, New Haven, CT, United States
| | - Angelique Bordey
- Departments of Neurosurgery and Cellular & Molecular Physiology, Wu Tsai Institute, Yale University School of Medicine, New Haven, CT, United States
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Ye X, Zhou Q, Ren P, Xiang W, Xiao L. The Synaptic and Circuit Functions of Vitamin D in Neurodevelopment Disorders. Neuropsychiatr Dis Treat 2023; 19:1515-1530. [PMID: 37424961 PMCID: PMC10327924 DOI: 10.2147/ndt.s407731] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 06/07/2023] [Indexed: 07/11/2023] Open
Abstract
Vitamin D deficiency/insufficiency is a public health issue around the world. According to epidemiological studies, low vitamin D levels have been associated with an increased risk of some neurodevelopmental disorders, including autism spectrum disorder (ASD) and attention-deficit hyperactivity disorder (ADHD). Animal models reveal that vitamin D has a variety of impacts on the synapses and circuits in the brain. A lack of vitamin D affects the expression of synaptic proteins, as well as the synthesis and metabolism of various neurotransmitters. Depending on where vitamin D receptors (VDRs) are expressed, vitamin D may also regulate certain neuronal circuits through the endocannabinoid signaling, mTOR pathway and oxytocin signaling. While inconsistently, some data suggest that vitamin D supplementation may be able to reduce the core symptoms of ASD and ADHD. This review emphasizes vitamin D's role in the synaptic and circuit mechanisms of neurodevelopmental disorders including ASD and ADHD. Future application of vitamin D in these disorders will depend on both basic research and clinical studies, in order to make the transition from the bench to the bedside.
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Affiliation(s)
- Xiaoshan Ye
- Hainan Women and Children’s Medical Center, School of Pediatrics, Hainan Medical University, Haikou, People’s Republic of China
| | - Qionglin Zhou
- International School of Public Health and One Health, Hainan Medical University, Haikou, People’s Republic of China
| | - Pengcheng Ren
- Hainan Women and Children’s Medical Center, School of Pediatrics, Hainan Medical University, Haikou, People’s Republic of China
- National Health Commission (NHC) Key Laboratory of Control of Tropical Diseases, Hainan Medical University, Haikou, People’s Republic of China
- School of Basic Medicine and Life Science, Hainan Medical University, Haikou, People’s Republic of China
| | - Wei Xiang
- Hainan Women and Children’s Medical Center, School of Pediatrics, Hainan Medical University, Haikou, People’s Republic of China
- National Health Commission (NHC) Key Laboratory of Control of Tropical Diseases, Hainan Medical University, Haikou, People’s Republic of China
| | - Le Xiao
- Hainan Women and Children’s Medical Center, School of Pediatrics, Hainan Medical University, Haikou, People’s Republic of China
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Narvaiz DA, Nolan SO, Smith GD, Holley AJ, Reynolds CD, Blandin KJ, Nguyen PH, Tran DLK, Lugo JN. Rapamycin improves social and stereotypic behavior abnormalities induced by pre-mitotic neuronal subset specific Pten deletion. GENES, BRAIN, AND BEHAVIOR 2023:e12854. [PMID: 37376966 PMCID: PMC10393422 DOI: 10.1111/gbb.12854] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 06/15/2023] [Accepted: 06/16/2023] [Indexed: 06/29/2023]
Abstract
The mechanistic target of rapamycin (mTOR) pathway is a signaling system integral to neural growth and migration. In both patients and rodent models, mutations to the phosphatase and tensin homolog gene (PTEN) on chromosome 10 results in hyperactivation of the mTOR pathway, as well as seizures, intellectual disabilities and autistic behaviors. Rapamycin, an inhibitor of mTOR, can reverse the epileptic phenotype of neural subset specific Pten knockout (NS-Pten KO) mice, but its impact on behavior is not known. To determine the behavioral effects of rapamycin, male and female NS-Pten KO and wildtype (WT) mice were assigned as controls or administered 10 mg/kg of rapamycin for 2 weeks followed by behavioral testing. Rapamycin improved social behavior in both genotypes and stereotypic behaviors in NS-Pten KO mice. Rapamycin treatment resulted in a reduction of several measures of activity in the open field test in both genotypes. Rapamycin did not reverse the reduced anxiety behavior in KO mice. These data show the potential clinical use of mTOR inhibitors by showing its administration can reduce the production of autistic-like behaviors in NS-Pten KO mice.
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Affiliation(s)
- David A Narvaiz
- Department of Psychology and Neuroscience, Baylor University, Waco, Texas, USA
| | - Suzanne O Nolan
- Department of Psychology and Neuroscience, Baylor University, Waco, Texas, USA
| | - Gregory D Smith
- Institute of Biomedical Studies, Baylor University, Waco, Texas, USA
| | - Andrew J Holley
- Department of Psychology and Neuroscience, Baylor University, Waco, Texas, USA
| | - Conner D Reynolds
- Department of Psychology and Neuroscience, Baylor University, Waco, Texas, USA
| | - Katherine J Blandin
- Department of Psychology and Neuroscience, Baylor University, Waco, Texas, USA
| | - Phuoc H Nguyen
- Department of Psychology and Neuroscience, Baylor University, Waco, Texas, USA
| | - Doan L K Tran
- Department of Psychology and Neuroscience, Baylor University, Waco, Texas, USA
| | - Joaquin N Lugo
- Department of Psychology and Neuroscience, Baylor University, Waco, Texas, USA
- Institute of Biomedical Studies, Baylor University, Waco, Texas, USA
- Department of Biology, Baylor University, Waco, Texas, USA
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Ramamurthy A, Carvill GL. Raptor Preys on mTOR Imbalance in Tuberous Sclerosis. Epilepsy Curr 2023; 23:193-195. [PMID: 37334409 PMCID: PMC10273816 DOI: 10.1177/15357597231176235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/20/2023] Open
Abstract
Raptor Downregulation Rescues Neuronal Phenotypes in Mouse Models of Tuberous Sclerosis Complex Karalis V, Caval-Holme F, Bateup HS. Nat Commun. 2022;13(1):4665. doi:10.1038/S41467-022-31961-6 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.
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Affiliation(s)
- Aishwarya Ramamurthy
- Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine
| | - Gemma Louise Carvill
- Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine
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