1
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Wang W, Wang Z, Cao J, Dong Y, Chen Y. Roles of Rac1-Dependent Intrinsic Forgetting in Memory-Related Brain Disorders: Demon or Angel. Int J Mol Sci 2023; 24:10736. [PMID: 37445914 DOI: 10.3390/ijms241310736] [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: 05/24/2023] [Revised: 06/14/2023] [Accepted: 06/21/2023] [Indexed: 07/15/2023] Open
Abstract
Animals are required to handle daily massive amounts of information in an ever-changing environment, and the resulting memories and experiences determine their survival and development, which is critical for adaptive evolution. However, intrinsic forgetting, which actively deletes irrelevant information, is equally important for memory acquisition and consolidation. Recently, it has been shown that Rac1 activity plays a key role in intrinsic forgetting, maintaining the balance of the brain's memory management system in a controlled manner. In addition, dysfunctions of Rac1-dependent intrinsic forgetting may contribute to memory deficits in neurological and neurodegenerative diseases. Here, these new findings will provide insights into the neurobiology of memory and forgetting, pathological mechanisms and potential therapies for brain disorders that alter intrinsic forgetting mechanisms.
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Affiliation(s)
- Wei Wang
- Neurobiology Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Zixu Wang
- Neurobiology Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Jing Cao
- Neurobiology Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Yulan Dong
- Neurobiology Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Yaoxing Chen
- Neurobiology Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
- Key Laboratory of Precision Nutrition and Food Quality, Key Laboratory of Functional Dairy, Ministry of Education, Beijing Laboratory of Food Quality and Safety, Department of Nutrition and Health, China Agricultural University, Beijing 100083, China
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2
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Liaci C, Camera M, Zamboni V, Sarò G, Ammoni A, Parmigiani E, Ponzoni L, Hidisoglu E, Chiantia G, Marcantoni A, Giustetto M, Tomagra G, Carabelli V, Torelli F, Sala M, Yanagawa Y, Obata K, Hirsch E, Merlo GR. Loss of ARHGAP15 affects the directional control of migrating interneurons in the embryonic cortex and increases susceptibility to epilepsy. Front Cell Dev Biol 2022; 10:875468. [PMID: 36568982 PMCID: PMC9774038 DOI: 10.3389/fcell.2022.875468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 11/07/2022] [Indexed: 12/13/2022] Open
Abstract
GTPases of the Rho family are components of signaling pathways linking extracellular signals to the control of cytoskeleton dynamics. Among these, RAC1 plays key roles during brain development, ranging from neuronal migration to neuritogenesis, synaptogenesis, and plasticity. RAC1 activity is positively and negatively controlled by guanine nucleotide exchange factors (GEFs), guanosine nucleotide dissociation inhibitors (GDIs), and GTPase-activating proteins (GAPs), but the specific role of each regulator in vivo is poorly known. ARHGAP15 is a RAC1-specific GAP expressed during development in a fraction of migrating cortical interneurons (CINs) and in the majority of adult CINs. During development, loss of ARHGAP15 causes altered directionality of the leading process of tangentially migrating CINs, along with altered morphology in vitro. Likewise, time-lapse imaging of embryonic CINs revealed a poorly coordinated directional control during radial migration, possibly due to a hyper-exploratory behavior. In the adult cortex, the observed defects lead to subtle alteration in the distribution of CALB2-, SST-, and VIP-positive interneurons. Adult Arhgap15-knock-out mice also show reduced CINs intrinsic excitability, spontaneous subclinical seizures, and increased susceptibility to the pro-epileptic drug pilocarpine. These results indicate that ARHGAP15 imposes a fine negative regulation on RAC1 that is required for morphological maturation and directional control during CIN migration, with consequences on their laminar distribution and inhibitory function.
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Affiliation(s)
- Carla Liaci
- Department of Molecular Biotechnologies and Health Sciences, University of Turin, Turin, Italy
| | - Mattia Camera
- Department of Molecular Biotechnologies and Health Sciences, University of Turin, Turin, Italy
| | - Valentina Zamboni
- Department of Molecular Biotechnologies and Health Sciences, University of Turin, Turin, Italy
| | - Gabriella Sarò
- Department of Molecular Biotechnologies and Health Sciences, University of Turin, Turin, Italy
| | - Alessandra Ammoni
- Department of Molecular Biotechnologies and Health Sciences, University of Turin, Turin, Italy
| | | | - Luisa Ponzoni
- Neuroscience Institute, Consiglio Nazionale Ricerche, Milan, Italy
| | - Enis Hidisoglu
- Department of Drug Science, NIS Center, University of Turin, Turin, Italy
| | - Giuseppe Chiantia
- Department of Neuroscience and National Institute of Neuroscience, University of Turin, Turin, Italy
| | - Andrea Marcantoni
- Department of Drug Science, NIS Center, University of Turin, Turin, Italy
| | - Maurizio Giustetto
- Department of Neuroscience and National Institute of Neuroscience, University of Turin, Turin, Italy
| | - Giulia Tomagra
- Department of Drug Science, NIS Center, University of Turin, Turin, Italy
| | | | - Federico Torelli
- Institute for Physiology I, Medical Faculty, Albert-Ludwigs-University Freiburg, Freiburg, Germany,Faculty of Biology, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Mariaelvina Sala
- Neuroscience Institute, Consiglio Nazionale Ricerche, Milan, Italy
| | - Yuchio Yanagawa
- Department of Genetic Behavioral Neuroscience, Gunma University, Maebashi, Japan
| | | | - Emilio Hirsch
- Department of Molecular Biotechnologies and Health Sciences, University of Turin, Turin, Italy
| | - Giorgio R. Merlo
- Department of Molecular Biotechnologies and Health Sciences, University of Turin, Turin, Italy,*Correspondence: Giorgio R. Merlo,
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3
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Zhang H, Ben Zablah Y, Zhang H, Liu A, Gugustea R, Lee D, Luo X, Meng Y, Li S, Zhou C, Xin T, Jia Z. Inhibition of Rac1 in ventral hippocampal excitatory neurons improves social recognition memory and synaptic plasticity. Front Aging Neurosci 2022; 14:914491. [PMID: 35936771 PMCID: PMC9354987 DOI: 10.3389/fnagi.2022.914491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 06/27/2022] [Indexed: 11/28/2022] Open
Abstract
Rac1 is critically involved in the regulation of the actin cytoskeleton, neuronal structure, synaptic plasticity, and memory. Rac1 overactivation is reported in human patients and animal models of Alzheimer’s disease (AD) and contributes to their spatial memory deficits, but whether Rac1 dysregulation is also important in other forms of memory deficits is unknown. In addition, the cell types and synaptic mechanisms involved remain unclear. In this study, we used local injections of AAV virus containing a dominant-negative (DN) Rac1 under the control of CaMKIIα promoter and found that the reduction of Rac1 hyperactivity in ventral hippocampal excitatory neurons improves social recognition memory in APP/PS1 mice. Expression of DN Rac1 also improves long-term potentiation, a key synaptic mechanism for memory formation. Our results suggest that overactivation of Rac1 in hippocampal excitatory neurons contributes to social memory deficits in APP/PS1 mice and that manipulating Rac1 activity may provide a potential therapeutic strategy to treat social deficits in AD.
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Affiliation(s)
- Haiwang Zhang
- Department of Neurosurgery, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Shandong Medicine and Health Key Laboratory of Neurosurgery, Jinan, China
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Youssif Ben Zablah
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Haorui Zhang
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - An Liu
- The Key Laboratory of Developmental Genes and Human Disease, Ministry of Education, School of Life Sciences and Technology, Southeast University, Nanjing, China
| | - Radu Gugustea
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Dongju Lee
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Xiao Luo
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Yanghong Meng
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Song Li
- Department of Neurosurgery, Caoxian People’s Hospital, Caoxian, China
| | - Changxi Zhou
- Department of Geriatrics, The Second Medical Center and National Clinical Research Center for Geriatric Diseases, Beijing, China
- *Correspondence: Changxi Zhou,
| | - Tao Xin
- Department of Neurosurgery, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Shandong Medicine and Health Key Laboratory of Neurosurgery, Jinan, China
- Tao Xin,
| | - Zhengping Jia
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Zhengping Jia,
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4
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Longatti A, Ponzoni L, Moretto E, Giansante G, Lattuada N, Colombo MN, Francolini M, Sala M, Murru L, Passafaro M. Arhgap22 Disruption Leads to RAC1 Hyperactivity Affecting Hippocampal Glutamatergic Synapses and Cognition in Mice. Mol Neurobiol 2021; 58:6092-6110. [PMID: 34455539 PMCID: PMC8639580 DOI: 10.1007/s12035-021-02502-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 07/15/2021] [Indexed: 11/03/2022]
Abstract
Rho GTPases are a class of G-proteins involved in several aspects of cellular biology, including the regulation of actin cytoskeleton. The most studied members of this family are RHOA and RAC1 that act in concert to regulate actin dynamics. Recently, Rho GTPases gained much attention as synaptic regulators in the mammalian central nervous system (CNS). In this context, ARHGAP22 protein has been previously shown to specifically inhibit RAC1 activity thus standing as critical cytoskeleton regulator in cancer cell models; however, whether this function is maintained in neurons in the CNS is unknown. Here, we generated a knockout animal model for arhgap22 and provided evidence of its role in the hippocampus. Specifically, we found that ARHGAP22 absence leads to RAC1 hyperactivity and to an increase in dendritic spine density with defects in synaptic structure, molecular composition, and plasticity. Furthermore, arhgap22 silencing causes impairment in cognition and a reduction in anxiety-like behavior in mice. We also found that inhibiting RAC1 restored synaptic plasticity in ARHGAP22 KO mice. All together, these results shed light on the specific role of ARHGAP22 in hippocampal excitatory synapse formation and function as well as in learning and memory behaviors.
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Affiliation(s)
- Anna Longatti
- Institute of Neuroscience, CNR, Milan, 20129, Italy
- Department of Pharmacological and Biomolecular Sciences, Università Degli Studi Di Milano, 20133, Milan, Italy
| | | | - Edoardo Moretto
- Institute of Neuroscience, CNR, Milan, 20129, Italy
- NeuroMI Milan Center for Neuroscience, Università Milano-Bicocca, 20126, Milan, Italy
| | - Giorgia Giansante
- Institute of Neuroscience, CNR, Milan, 20129, Italy
- NeuroMI Milan Center for Neuroscience, Università Milano-Bicocca, 20126, Milan, Italy
| | - Norma Lattuada
- Department of Medical Biotechnology and Translational Medicine, Università Degli Studi Di Milano, 20129, Milan, Italy
| | - Maria Nicol Colombo
- Department of Medical Biotechnology and Translational Medicine, Università Degli Studi Di Milano, 20129, Milan, Italy
| | - Maura Francolini
- Department of Medical Biotechnology and Translational Medicine, Università Degli Studi Di Milano, 20129, Milan, Italy
| | - Mariaelvina Sala
- Institute of Neuroscience, CNR, Milan, 20129, Italy
- NeuroMI Milan Center for Neuroscience, Università Milano-Bicocca, 20126, Milan, Italy
| | - Luca Murru
- Institute of Neuroscience, CNR, Milan, 20129, Italy.
- NeuroMI Milan Center for Neuroscience, Università Milano-Bicocca, 20126, Milan, Italy.
| | - Maria Passafaro
- Institute of Neuroscience, CNR, Milan, 20129, Italy.
- NeuroMI Milan Center for Neuroscience, Università Milano-Bicocca, 20126, Milan, Italy.
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5
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Zhang H, Ben Zablah Y, Zhang H, Jia Z. Rho Signaling in Synaptic Plasticity, Memory, and Brain Disorders. Front Cell Dev Biol 2021; 9:729076. [PMID: 34671600 PMCID: PMC8520953 DOI: 10.3389/fcell.2021.729076] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 09/03/2021] [Indexed: 12/12/2022] Open
Abstract
Memory impairments are associated with many brain disorders such as autism, Alzheimer's disease, and depression. Forming memories involves modifications of synaptic transmission and spine morphology. The Rho family small GTPases are key regulators of synaptic plasticity by affecting various downstream molecules to remodel the actin cytoskeleton. In this paper, we will review recent studies on the roles of Rho proteins in the regulation of hippocampal long-term potentiation (LTP) and long-term depression (LTD), the most extensively studied forms of synaptic plasticity widely regarded as cellular mechanisms for learning and memory. We will also discuss the involvement of Rho signaling in spine morphology, the structural basis of synaptic plasticity and memory formation. Finally, we will review the association between brain disorders and abnormalities of Rho function. It is expected that studying Rho signaling at the synapse will contribute to the understanding of how memory is formed and disrupted in diseases.
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Affiliation(s)
- Haorui Zhang
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Youssif Ben Zablah
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Haiwang Zhang
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Zhengping Jia
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
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6
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Birkhoff JC, Brouwer RWW, Kolovos P, Korporaal AL, Bermejo-Santos A, Boltsis I, Nowosad K, van den Hout MCGN, Grosveld FG, van IJcken WFJ, Huylebroeck D, Conidi A. Targeted chromatin conformation analysis identifies novel distal neural enhancers of ZEB2 in pluripotent stem cell differentiation. Hum Mol Genet 2021; 29:2535-2550. [PMID: 32628253 PMCID: PMC7471508 DOI: 10.1093/hmg/ddaa141] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 06/29/2020] [Accepted: 06/30/2020] [Indexed: 12/25/2022] Open
Abstract
The transcription factor zinc finger E-box binding protein 2 (ZEB2) controls embryonic and adult cell fate decisions and cellular maturation in many stem/progenitor cell types. Defects in these processes in specific cell types underlie several aspects of Mowat–Wilson syndrome (MOWS), which is caused by ZEB2 haplo-insufficiency. Human ZEB2, like mouse Zeb2, is located on chromosome 2 downstream of a ±3.5 Mb-long gene-desert, lacking any protein-coding gene. Using temporal targeted chromatin capture (T2C), we show major chromatin structural changes based on mapping in-cis proximities between the ZEB2 promoter and this gene desert during neural differentiation of human-induced pluripotent stem cells, including at early neuroprogenitor cell (NPC)/rosette state, where ZEB2 mRNA levels increase significantly. Combining T2C with histone-3 acetylation mapping, we identified three novel candidate enhancers about 500 kb upstream of the ZEB2 transcription start site. Functional luciferase-based assays in heterologous cells and NPCs reveal co-operation between these three enhancers. This study is the first to document in-cis Regulatory Elements located in ZEB2’s gene desert. The results further show the usability of T2C for future studies of ZEB2 REs in differentiation and maturation of multiple cell types and the molecular characterization of newly identified MOWS patients that lack mutations in ZEB2 protein-coding exons.
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Affiliation(s)
- Judith C Birkhoff
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam, CN 3015, The Netherlands
| | - Rutger W W Brouwer
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam, CN 3015, The Netherlands.,Center for Biomics, Erasmus University Medical Center, Rotterdam, CN 3015, The Netherlands
| | - Petros Kolovos
- Department of Molecular Biology and Genetics, Democritus University of Thrace, Alexandroupolis 68100, Greece
| | - Anne L Korporaal
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam, CN 3015, The Netherlands
| | - Ana Bermejo-Santos
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam, CN 3015, The Netherlands
| | - Ilias Boltsis
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam, CN 3015, The Netherlands
| | - Karol Nowosad
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam, CN 3015, The Netherlands.,Department of Biochemistry and Molecular Biology, Medical University of Lublin, Lublin 20-093, Poland
| | - Mirjam C G N van den Hout
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam, CN 3015, The Netherlands.,Center for Biomics, Erasmus University Medical Center, Rotterdam, CN 3015, The Netherlands
| | - Frank G Grosveld
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam, CN 3015, The Netherlands
| | - Wilfred F J van IJcken
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam, CN 3015, The Netherlands.,Center for Biomics, Erasmus University Medical Center, Rotterdam, CN 3015, The Netherlands
| | - Danny Huylebroeck
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam, CN 3015, The Netherlands.,Department of Development and Regeneration, KU Leuven, Leuven B-3000, Belgium
| | - Andrea Conidi
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam, CN 3015, The Netherlands
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7
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Liaci C, Camera M, Caslini G, Rando S, Contino S, Romano V, Merlo GR. Neuronal Cytoskeleton in Intellectual Disability: From Systems Biology and Modeling to Therapeutic Opportunities. Int J Mol Sci 2021; 22:ijms22116167. [PMID: 34200511 PMCID: PMC8201358 DOI: 10.3390/ijms22116167] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 05/25/2021] [Accepted: 06/04/2021] [Indexed: 02/06/2023] Open
Abstract
Intellectual disability (ID) is a pathological condition characterized by limited intellectual functioning and adaptive behaviors. It affects 1–3% of the worldwide population, and no pharmacological therapies are currently available. More than 1000 genes have been found mutated in ID patients pointing out that, despite the common phenotype, the genetic bases are highly heterogeneous and apparently unrelated. Bibliomic analysis reveals that ID genes converge onto a few biological modules, including cytoskeleton dynamics, whose regulation depends on Rho GTPases transduction. Genetic variants exert their effects at different levels in a hierarchical arrangement, starting from the molecular level and moving toward higher levels of organization, i.e., cell compartment and functions, circuits, cognition, and behavior. Thus, cytoskeleton alterations that have an impact on cell processes such as neuronal migration, neuritogenesis, and synaptic plasticity rebound on the overall establishment of an effective network and consequently on the cognitive phenotype. Systems biology (SB) approaches are more focused on the overall interconnected network rather than on individual genes, thus encouraging the design of therapies that aim to correct common dysregulated biological processes. This review summarizes current knowledge about cytoskeleton control in neurons and its relevance for the ID pathogenesis, exploiting in silico modeling and translating the implications of those findings into biomedical research.
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Affiliation(s)
- Carla Liaci
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126 Torino, Italy; (C.L.); (M.C.); (G.C.); (S.R.)
| | - Mattia Camera
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126 Torino, Italy; (C.L.); (M.C.); (G.C.); (S.R.)
| | - Giovanni Caslini
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126 Torino, Italy; (C.L.); (M.C.); (G.C.); (S.R.)
| | - Simona Rando
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126 Torino, Italy; (C.L.); (M.C.); (G.C.); (S.R.)
| | - Salvatore Contino
- Department of Engineering, University of Palermo, Viale delle Scienze Ed. 8, 90128 Palermo, Italy;
| | - Valentino Romano
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Viale delle Scienze Ed. 16, 90128 Palermo, Italy;
| | - Giorgio R. Merlo
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126 Torino, Italy; (C.L.); (M.C.); (G.C.); (S.R.)
- Correspondence: ; Tel.: +39-0116706449; Fax: +39-0116706432
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8
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Margraf A, Cappenberg A, Vadillo E, Ludwig N, Thomas K, Körner K, Zondler L, Rossaint J, Germena G, Hirsch E, Zarbock A. ArhGAP15, a RacGAP, Acts as a Temporal Signaling Regulator of Mac-1 Affinity in Sterile Inflammation. THE JOURNAL OF IMMUNOLOGY 2020; 205:1365-1375. [PMID: 32839212 DOI: 10.4049/jimmunol.2000047] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 06/22/2020] [Indexed: 01/06/2023]
Abstract
During inflammation, leukocyte recruitment has to be tightly controlled to prevent overwhelming leukocyte infiltration, activation, and, consequently, organ damage. A central regulator of leukocyte recruitment is Rac1. In this study, we analyzed the effects of the RacGAP ArhGAP15 on leukocyte recruitment. Using ArhGAP15-deficient mice, reduced neutrophil adhesion and transmigration in the TNF-α-inflamed cremaster muscle and a prolongation of chemokine-dependent leukocyte adhesion could be observed. In a murine model of sterile kidney injury, reduced neutrophil infiltration, and serum creatinine levels were apparent. Further in vitro and in vivo analyses revealed a defective intravascular crawling capacity, resulting from increased affinity of the β2-integrin Mac-1 after prolonged chemokine stimulation of neutrophils. LFA-1 activity regulation was not affected. Summarizing, ArhGAP15 specifically regulates Mac-1, but not LFA-1, and affects leukocyte recruitment by controlling postadhesion strengthening and intravascular crawling in a Mac-1-dependent manner. In conclusion, ArhGAP15 is involved in the time-dependent regulation of leukocyte postadhesion in sterile inflammation.
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Affiliation(s)
- Andreas Margraf
- Department of Anesthesiology, Intensive Care and Pain Medicine, University Hospital Muenster, 48149 Muenster, Germany; and
| | - Anika Cappenberg
- Department of Anesthesiology, Intensive Care and Pain Medicine, University Hospital Muenster, 48149 Muenster, Germany; and
| | - Eduardo Vadillo
- Department of Anesthesiology, Intensive Care and Pain Medicine, University Hospital Muenster, 48149 Muenster, Germany; and
| | - Nadine Ludwig
- Department of Anesthesiology, Intensive Care and Pain Medicine, University Hospital Muenster, 48149 Muenster, Germany; and
| | - Katharina Thomas
- Department of Anesthesiology, Intensive Care and Pain Medicine, University Hospital Muenster, 48149 Muenster, Germany; and
| | - Katharina Körner
- Department of Anesthesiology, Intensive Care and Pain Medicine, University Hospital Muenster, 48149 Muenster, Germany; and
| | - Lisa Zondler
- Department of Anesthesiology, Intensive Care and Pain Medicine, University Hospital Muenster, 48149 Muenster, Germany; and
| | - Jan Rossaint
- Department of Anesthesiology, Intensive Care and Pain Medicine, University Hospital Muenster, 48149 Muenster, Germany; and
| | - Giulia Germena
- Department of Anesthesiology, Intensive Care and Pain Medicine, University Hospital Muenster, 48149 Muenster, Germany; and
| | - Emilio Hirsch
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, 10126 Torino, Italy
| | - Alexander Zarbock
- Department of Anesthesiology, Intensive Care and Pain Medicine, University Hospital Muenster, 48149 Muenster, Germany; and
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9
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Costa JF, Dines M, Lamprecht R. The Role of Rac GTPase in Dendritic Spine Morphogenesis and Memory. Front Synaptic Neurosci 2020; 12:12. [PMID: 32362820 PMCID: PMC7182350 DOI: 10.3389/fnsyn.2020.00012] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 03/04/2020] [Indexed: 11/21/2022] Open
Abstract
The ability to form memories in the brain is needed for daily functions, and its impairment is associated with human mental disorders. Evidence indicates that long-term memory (LTM)-related processes such as its consolidation, extinction and forgetting involve changes of synaptic efficacy produced by alterations in neural transmission and morphology. Modulation of the morphology and number of dendritic spines has been proposed to contribute to changes in neuronal transmission mediating such LTM-related processes. Rac GTPase activity is regulated by synaptic activation and it can affect spine morphology by controlling actin-regulatory proteins. Recent evidence shows that changes in Rac GTPase activity affect memory consolidation, extinction, erasure and forgetting and can affect spine morphology in brain areas that mediate these behaviors. Altered Rac GTPase activity is associated with abnormal spine morphology and brain disorders. By affecting Rac GTPase activity we can further understand the roles of spine morphogenesis in memory. Moreover, manipulation of Rac GTPase activity may serve as a therapeutic tool for the treatment of memory-related brain diseases.
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Affiliation(s)
| | | | - Raphael Lamprecht
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
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10
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TrkB hyperactivity contributes to brain dysconnectivity, epileptogenesis, and anxiety in zebrafish model of Tuberous Sclerosis Complex. Proc Natl Acad Sci U S A 2020; 117:2170-2179. [PMID: 31932427 PMCID: PMC6995026 DOI: 10.1073/pnas.1910834117] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Tuberous Sclerosis Complex (TSC) is a rare genetic disease that manifests with early symptoms, including cortical malformations, childhood epilepsy, and TSC-associated neuropsychiatric disorders (TANDs). Cortical malformations arise during embryonic development and have been linked to childhood epilepsy before, but the underlying mechanisms of this relationship remain insufficiently understood. Zebrafish have emerged as a convenient model to study elementary neurodevelopment; however, without in-depth functional analysis, the Tsc2-deficient zebrafish line cannot be used for studies of TANDs or new drug screening. In this study, we found that the lack of Tsc2 in zebrafish resulted in heterotopias and hyperactivation of the mTorC1 pathway in pallial regions, which are homologous to the mammalian cortex. We observed commissural thinning that was responsible for brain dysconnectivity, recapitulating TSC pathology in human patients. The lack of Tsc2 also delayed axonal development and caused aberrant tract fasciculation, corresponding to the abnormal expression of genes involved in axon navigation. The mutants underwent epileptogenesis that resulted in nonmotor seizures and exhibited increased anxiety-like behavior. We further mapped discrete parameters of locomotor activity to epilepsy-like and anxiety-like behaviors, which were rescued by reducing tyrosine receptor kinase B (TrkB) signaling. Moreover, in contrast to treatment with vigabatrin and rapamycin, TrkB inhibition rescued brain dysconnectivity and anxiety-like behavior. These data reveal that commissural thinning results in the aberrant regulation of anxiety, providing a mechanistic link between brain anatomy and human TANDs. Our findings also implicate TrkB signaling in the complex pathology of TSC and reveal a therapeutic target.
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Barešić A, Nash AJ, Dahoun T, Howes O, Lenhard B. Understanding the genetics of neuropsychiatric disorders: the potential role of genomic regulatory blocks. Mol Psychiatry 2020; 25:6-18. [PMID: 31616042 PMCID: PMC6906185 DOI: 10.1038/s41380-019-0518-x] [Citation(s) in RCA: 22] [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: 11/08/2018] [Revised: 06/18/2019] [Accepted: 07/09/2019] [Indexed: 01/30/2023]
Abstract
Recent genome-wide association studies have identified numerous loci associated with neuropsychiatric disorders. The majority of these are in non-coding regions, and are commonly assigned to the nearest gene along the genome. However, this approach neglects the three-dimensional organisation of the genome, and the fact that the genome contains arrays of extremely conserved non-coding elements termed genomic regulatory blocks (GRBs), which can be utilized to detect genes under long-range developmental regulation. Here we review a GRB-based approach to assign loci in non-coding regions to potential target genes, and apply it to reanalyse the results of one of the largest schizophrenia GWAS (SWG PGC, 2014). We further apply this approach to GWAS data from two related neuropsychiatric disorders-autism spectrum disorder and bipolar disorder-to show that it is applicable to developmental disorders in general. We find that disease-associated SNPs are overrepresented in GRBs and that the GRB model is a powerful tool for linking these SNPs to their correct target genes under long-range regulation. Our analysis identifies novel genes not previously implicated in schizophrenia and corroborates a number of predicted targets from the original study. The results are available as an online resource in which the genomic context and the strength of enhancer-promoter associations can be browsed for each schizophrenia-associated SNP.
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Affiliation(s)
- Anja Barešić
- MRC London Institute of Medical Sciences, London, W12 0NN, UK
| | - Alexander Jolyon Nash
- MRC London Institute of Medical Sciences, London, W12 0NN, UK
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, W12 0NN, UK
| | - Tarik Dahoun
- MRC London Institute of Medical Sciences, London, W12 0NN, UK
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, W12 0NN, UK
- Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford, OX37 JX, UK
| | - Oliver Howes
- MRC London Institute of Medical Sciences, London, W12 0NN, UK
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, W12 0NN, UK
| | - Boris Lenhard
- MRC London Institute of Medical Sciences, London, W12 0NN, UK.
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, W12 0NN, UK.
- Sars International Centre for Marine Molecular Biology, University of Bergen, N-5008, Bergen, Norway.
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12
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Zhao J, Ying L, Liu Y, Liu N, Tu G, Zhu M, Wu Y, Xiao B, Ye L, Li J, Guo F, Zhang L, Wang H, Zhang L. Different roles of Rac1 in the acquisition and extinction of methamphetamine-associated contextual memory in the nucleus accumbens. Am J Cancer Res 2019; 9:7051-7071. [PMID: 31660086 PMCID: PMC6815963 DOI: 10.7150/thno.34655] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 07/30/2019] [Indexed: 02/03/2023] Open
Abstract
Rationale: Repeated methamphetamine (METH) exposure induces long-term cognitive deficits and pathological drug-associated memory that can be disrupted by manipulating memory reconsolidation and extinction. The nucleus accumbens (NAc) is the key region of the brain reward system and predominantly consists of two subtypes of medium spiny neurons (MSNs) based on the expression of D1 or D2 dopamine receptors (D1-MSNs or D2-MSNs). Spine structural plasticity in the NAc is critical for the acquisition, reconsolidation and extinction of drug-associated memory. However, the molecular mechanisms underlying METH-associated memory and spine remodelling in each type of MSNs in the NAc remain unknown. Here, we explored whether Rac1 in the NAc mediates METH-associated contextual memory and spine remodelling. Methods: Pharmacological and genetic manipulations of Rac1 were used to investigate its role during the acquisition, reconsolidation and extinction of METH-associated contextual memory. Recombinant adeno-associated viruses expressing mCherry under the control of the dopamine D1 receptor gene promoter (Drd1-mCherry) or dopamine D2 receptor gene promoter (Drd2-mCherry) were used to specifically label D1-MSNs or D2-MSNs. Results: Using viral-mediated gene transfer, we demonstrated that decreased Rac1 activity was required for the acquisition of METH-associated contextual memory and the METH-induced increase in thin spine density, whereas increased Rac1 signalling was important for the extinction of METH-associated contextual memory and the related elimination of thin spines. Moreover, the increase of dendritic spines was both found in D1-MSNs and D2-MSNs during the acquisition process, but extinction training selectively decreased the spine density in D1-MSNs. Interestingly, Rac1 was responsible for METH-induced spine plasticity in D1-MSNs but not in D2-MSNs. Additionally, we found that microinjection of a Rac1 inhibitor or activator into the NAc was not sufficient to disrupt reconsolidation, and the pharmacological activation of Rac1 in the NAc facilitated the extinction of METH-associated contextual memory. Regarding cognitive memory, decreased Rac1 activity improved the METH-induced impairment in object recognition memory. Conclusion: Our findings indicate that Rac1 plays opposing roles in the acquisition and extinction of METH-associated contextual memory and reveal the cell-specific role of Rac1 in METH-associated spine remodelling, suggesting that Rac1 is a potential therapeutic target for reducing relapse in METH addiction and remediating METH-induced recognition memory impairment.
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Camilleri M, Sandler RS, Peery AF. Etiopathogenetic Mechanisms in Diverticular Disease of the Colon. Cell Mol Gastroenterol Hepatol 2019; 9:15-32. [PMID: 31351939 PMCID: PMC6881605 DOI: 10.1016/j.jcmgh.2019.07.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 07/17/2019] [Accepted: 07/18/2019] [Indexed: 02/08/2023]
Abstract
This article reviews epidemiological evidence of heritability and putative mechanisms in diverticular disease, with greatest attention to 3 recent studies of genetic associations with diverticular disease based on genome-wide or whole-genome sequencing studies in large patient cohorts. We provide an analysis of the biological plausibility of the significant associations with gene variants reported and highlight the relevance of ANO1, CPI-17 (aka PPP1R14A), COLQ6, COL6A1, CALCB or CALCA, COL6A1, ARHGAP15, and S100A10 to colonic neuromuscular function and tissue properties that may result in altered compliance and predispose to the development of diverticular disease. Such studies also identify candidate genes for future studies.
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Affiliation(s)
- Michael Camilleri
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota
| | - Robert S Sandler
- Center for Gastrointestinal Biology and Disease, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Anne F Peery
- Center for Gastrointestinal Biology and Disease, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
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Diring J, Mouilleron S, McDonald NQ, Treisman R. RPEL-family rhoGAPs link Rac/Cdc42 GTP loading to G-actin availability. Nat Cell Biol 2019; 21:845-855. [PMID: 31209295 PMCID: PMC6960015 DOI: 10.1038/s41556-019-0337-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 04/29/2019] [Indexed: 12/29/2022]
Abstract
RPEL proteins, which contain the G-actin-binding RPEL motif, coordinate cytoskeletal processes with actin dynamics. We show that the ArhGAP12- and ArhGAP32-family GTPase-activating proteins (GAPs) are RPEL proteins. We determine the structure of the ArhGAP12/G-actin complex, and show that G-actin contacts the RPEL motif and GAP domain sequences. G-actin inhibits ArhGAP12 GAP activity, and this requires the G-actin contacts identified in the structure. In B16 melanoma cells, ArhGAP12 suppresses basal Rac and Cdc42 activity, F-actin assembly, invadopodia formation and experimental metastasis. In this setting, ArhGAP12 mutants defective for G-actin binding exhibit more effective downregulation of Rac GTP loading following HGF stimulation and enhanced inhibition of Rac-dependent processes, including invadopodia formation. Potentiation or disruption of the G-actin/ArhGAP12 interaction, by treatment with the actin-binding drugs latrunculin B or cytochalasin D, has corresponding effects on Rac GTP loading. The interaction of G-actin with RPEL-family rhoGAPs thus provides a negative feedback loop that couples Rac activity to actin dynamics.
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Affiliation(s)
- Jessica Diring
- Signalling and Transcription Group, The Francis Crick Institute, London, UK
| | - Stephane Mouilleron
- Structural Biology Science Technology Platform, The Francis Crick Institute, London, UK
| | - Neil Q McDonald
- Signalling and Structural Biology Group, The Francis Crick Institute, London, UK
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck College, London, UK
| | - Richard Treisman
- Signalling and Transcription Group, The Francis Crick Institute, London, UK.
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Conditional Deletion of CC2D1A Reduces Hippocampal Synaptic Plasticity and Impairs Cognitive Function through Rac1 Hyperactivation. J Neurosci 2019; 39:4959-4975. [PMID: 30992372 DOI: 10.1523/jneurosci.2395-18.2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 04/11/2019] [Accepted: 04/14/2019] [Indexed: 11/21/2022] Open
Abstract
Coiled-coil and C2 domain containing 1A (CC2D1A) is an evolutionarily conserved protein, originally identified as a nuclear factor-κB activator through a large-scale screen of human genes. Mutations in the human Cc2d1a gene result in autosomal recessive nonsyndromic intellectual disability. It remains unclear, however, how Cc2d1a mutation leads to alterations in brain function. Here, we have taken advantage of Cre/loxP recombinase-based strategy to conditionally delete Cc2d1a exclusively from excitatory neurons of male mouse forebrain to examine its role in hippocampal synaptic plasticity and cognitive function. We confirmed the expression of CC2D1A protein and mRNA in the mouse hippocampus. Double immunofluorescence staining showed that CC2D1A is expressed in both excitatory and inhibitory neurons of the adult hippocampus. Conditional deletion of Cc2d1a (cKO) from excitatory neurons leads to impaired performance in object location memory test and altered anxiety-like behavior. Consistently, cKO mice displayed a deficit in the maintenance of LTP in the CA1 region of hippocampal slices. Cc2d1a deletion also resulted in decreased complexity of apical and basal dendritic arbors of CA1 pyramidal neurons. An enhanced basal Rac1 activity was observed following Cc2d1a deletion, and this enhancement was mediated by reduced SUMO-specific protease 1 (SENP1) and SENP3 expression, thus increasing the amount of Rac1 SUMOylation. Furthermore, partial blockade of Rac1 activity rescued impairments in LTP and object location memory performance in cKO mice. Together, our results implicate Rac1 hyperactivity in synaptic plasticity and cognitive deficits observed in Cc2d1a cKO mice and reveal a novel role for CC2D1A in regulating hippocampal synaptic function.SIGNIFICANCE STATEMENT CC2D1A is abundantly expressed in the brain, but there is little known about its physiological function. Taking advantage of Cc2d1a cKO mice, the present study highlights the importance of CC2D1A in the maintenance of LTP at Schaffer collateral-CA1 synapses and the formation of hippocampus-dependent long-term object location memory. Our findings establish a critical link between elevated Rac1 activity, structural and synaptic plasticity alterations, and cognitive impairment caused by Cc2d1a deletion. Moreover, partial blockade of Rac1 activity rescues synaptic plasticity and memory deficits in Cc2d1a cKO mice. Such insights may have implications for the utility of Rac1 inhibitors in the treatment of intellectual disability caused by Cc2d1a mutations in human patients.
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Niftullayev S, Lamarche-Vane N. Regulators of Rho GTPases in the Nervous System: Molecular Implication in Axon Guidance and Neurological Disorders. Int J Mol Sci 2019; 20:E1497. [PMID: 30934641 PMCID: PMC6471118 DOI: 10.3390/ijms20061497] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 03/18/2019] [Indexed: 12/11/2022] Open
Abstract
One of the fundamental steps during development of the nervous system is the formation of proper connections between neurons and their target cells-a process called neural wiring, failure of which causes neurological disorders ranging from autism to Down's syndrome. Axons navigate through the complex environment of a developing embryo toward their targets, which can be far away from their cell bodies. Successful implementation of neuronal wiring, which is crucial for fulfillment of all behavioral functions, is achieved through an intimate interplay between axon guidance and neural activity. In this review, our focus will be on axon pathfinding and the implication of some of its downstream molecular components in neurological disorders. More precisely, we will talk about axon guidance and the molecules implicated in this process. After, we will briefly review the Rho family of small GTPases, their regulators, and their involvement in downstream signaling pathways of the axon guidance cues/receptor complexes. We will then proceed to the final and main part of this review, where we will thoroughly comment on the implication of the regulators for Rho GTPases-GEFs (Guanine nucleotide Exchange Factors) and GAPs (GTPase-activating Proteins)-in neurological diseases and disorders.
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Affiliation(s)
- Sadig Niftullayev
- Cancer Research Program, Research Institute of the MUHC, Montreal, QC H4A 3J1, Canada.
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC H3A 2B2, Canada.
| | - Nathalie Lamarche-Vane
- Cancer Research Program, Research Institute of the MUHC, Montreal, QC H4A 3J1, Canada.
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC H3A 2B2, Canada.
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Rho GTPases in Intellectual Disability: From Genetics to Therapeutic Opportunities. Int J Mol Sci 2018; 19:ijms19061821. [PMID: 29925821 PMCID: PMC6032284 DOI: 10.3390/ijms19061821] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 06/14/2018] [Accepted: 06/16/2018] [Indexed: 12/22/2022] Open
Abstract
Rho-class small GTPases are implicated in basic cellular processes at nearly all brain developmental steps, from neurogenesis and migration to axon guidance and synaptic plasticity. GTPases are key signal transducing enzymes that link extracellular cues to the neuronal responses required for the construction of neuronal networks, as well as for synaptic function and plasticity. Rho GTPases are highly regulated by a complex set of activating (GEFs) and inactivating (GAPs) partners, via protein:protein interactions (PPI). Misregulated RhoA, Rac1/Rac3 and cdc42 activity has been linked with intellectual disability (ID) and other neurodevelopmental conditions that comprise ID. All genetic evidences indicate that in these disorders the RhoA pathway is hyperactive while the Rac1 and cdc42 pathways are consistently hypoactive. Adopting cultured neurons for in vitro testing and specific animal models of ID for in vivo examination, the endophenotypes associated with these conditions are emerging and include altered neuronal networking, unbalanced excitation/inhibition and altered synaptic activity and plasticity. As we approach a clearer definition of these phenotype(s) and the role of hyper- and hypo-active GTPases in the construction of neuronal networks, there is an increasing possibility that selective inhibitors and activators might be designed via PPI, or identified by screening, that counteract the misregulation of small GTPases and result in alleviation of the cognitive condition. Here we review all knowledge in support of this possibility.
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Joensuu M, Lanoue V, Hotulainen P. Dendritic spine actin cytoskeleton in autism spectrum disorder. Prog Neuropsychopharmacol Biol Psychiatry 2018; 84:362-381. [PMID: 28870634 DOI: 10.1016/j.pnpbp.2017.08.023] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 08/21/2017] [Accepted: 08/30/2017] [Indexed: 01/01/2023]
Abstract
Dendritic spines are small actin-rich protrusions from neuronal dendrites that form the postsynaptic part of most excitatory synapses. Changes in the shape and size of dendritic spines correlate with the functional changes in excitatory synapses and are heavily dependent on the remodeling of the underlying actin cytoskeleton. Recent evidence implicates synapses at dendritic spines as important substrates of pathogenesis in neuropsychiatric disorders, including autism spectrum disorder (ASD). Although synaptic perturbations are not the only alterations relevant for these diseases, understanding the molecular underpinnings of the spine and synapse pathology may provide insight into their etiologies and could reveal new drug targets. In this review, we will discuss recent findings of defective actin regulation in dendritic spines associated with ASD.
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Affiliation(s)
- Merja Joensuu
- Minerva Foundation Institute for Medical Research, 00290 Helsinki, Finland; Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, Queensland 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Vanessa Lanoue
- Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, Queensland 4072, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Pirta Hotulainen
- Minerva Foundation Institute for Medical Research, 00290 Helsinki, Finland.
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Hyperactivity of Rac1-GTPase pathway impairs neuritogenesis of cortical neurons by altering actin dynamics. Sci Rep 2018; 8:7254. [PMID: 29740022 PMCID: PMC5940682 DOI: 10.1038/s41598-018-25354-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 04/18/2018] [Indexed: 01/10/2023] Open
Abstract
The small-GTPase Rac1 is a key molecular regulator linking extracellular signals to actin cytoskeleton dynamics. Loss-of-function mutations in RAC1 and other genes of the Rac signaling pathway have been implicated in the pathogenesis of Intellectual Disability (ID). The Rac1 activity is negatively controlled by GAP proteins, however the effect of Rac1 hyperactivity on neuronal networking in vivo has been poorly studied. ArhGAP15 is a Rac-specific negative regulator, expressed in the main subtypes of pyramidal cortical neurons. In the absence of ArhGAP15, cortical pyramidal neurons show defective neuritogenesis, delayed axonal elongation, reduced dendritic branching, both in vitro and in vivo. These phenotypes are associated with altered actin dynamics at the growth cone due to increased activity of the PAK-LIMK pathway and hyperphosphorylation of ADF/cofilin. These results can be explained by shootin1 hypo-phosphorylation and uncoupling with the adhesion system. Functionally, ArhGAP15−/− mice exhibit decreased synaptic density, altered electroencephalographic rhythms and cognitive deficits. These data suggest that both hypo- and hyperactivation of the Rac pathway due to mutations in Rac1 regulators can result in conditions of ID, and that a tight regulation of Rac1 activity is required to attain the full complexity of the cortical networks.
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Chen F, Danladi J, Ardalan M, Elfving B, Müller HK, Wegener G, Sanchez C, Nyengaard JR. A Critical Role of Mitochondria in BDNF-Associated Synaptic Plasticity After One-Week Vortioxetine Treatment. Int J Neuropsychopharmacol 2018; 21. [PMID: 29514282 PMCID: PMC6007239 DOI: 10.1093/ijnp/pyy022] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Preclinical studies have indicated that antidepressant effect of vortioxetine involves increased synaptic plasticity and promotion of spine maturation. Mitochondria dysfunction may contribute to the pathophysiological basis of major depressive disorder. Taking into consideration that vortioxetine increases spine number and dendritic branching in hippocampus CA1 faster than fluoxetine, we hypothesize that new spines induced by vortioxetine can rapidly form functional synapses by mitochondrial support, accompanied by increased brain-derived neurotrophic factor signaling. METHODS Rats were treated for 1 week with vortioxetine or fluoxetine at pharmacologically relevant doses. Number of synapses and mitochondria in hippocampus CA1 were quantified by electron microscopy. Brain-derived neurotrophic factor protein levels were visualized with immunohistochemistry. Gene and protein expression of synapse and mitochondria-related markers were investigated with real-time quantitative polymerase chain reaction and immunoblotting. RESULTS Vortioxetine increased number of synapses and mitochondria significantly, whereas fluoxetine had no effect after 1-week dosing. BDNF levels in hippocampus DG and CA1 were significantly higher after vortioxetine treatment. Gene expression levels of Rac1 after vortioxetine treatment were significantly increased. There was a tendency towards increased gene expression levels of Drp1 and protein levels of Rac1. However, both gene and protein levels of c-Fos were significantly decreased. Furthermore, there was a significant positive correlation between BDNF levels and mitochondria and synapse numbers. CONCLUSION Our results imply that mitochondria play a critical role in synaptic plasticity accompanied by increased BDNF levels. Rapid changes in BDNF levels and synaptic/mitochondria plasticity of hippocampus following vortioxetine compared with fluoxetine may be ascribed to vortioxetine's modulation of serotonin receptors.
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Affiliation(s)
- Fenghua Chen
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Risskov, Denmark
- Core Center for Molecular Morphology, Section for Stereology and Microscopy, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Correspondence: Fenghua Chen, Department of Clinical Medicine - Translational Neuropsychiatry Unit, Skovagervej 2, 8240 Risskov, Denmark ()
| | - Jibrin Danladi
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Risskov, Denmark
| | - Maryam Ardalan
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Risskov, Denmark
- Department of Clinical Medicine - Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
| | - Betina Elfving
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Risskov, Denmark
| | - Heidi K Müller
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Risskov, Denmark
| | - Gregers Wegener
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Risskov, Denmark
- Center of Excellence for Pharmaceutical Sciences, North-West University, Potchefstroom, South Africa
- AUGUST Centre, Department of Clinical Medicine, Aarhus University, Risskov, Denmark
| | - Connie Sanchez
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Risskov, Denmark
- Alkermes, Biotechnology, Waltham, MA
| | - Jens R Nyengaard
- Core Center for Molecular Morphology, Section for Stereology and Microscopy, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Centre for Stochastic Geometry and Advanced Bioimaging, Aarhus University, Aarhus, Denmark
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Barcelona de Mendoza V, Huang Y, Crusto CA, Sun YV, Taylor JY. Perceived Racial Discrimination and DNA Methylation Among African American Women in the InterGEN Study. Biol Res Nurs 2018; 20:145-152. [PMID: 29258399 PMCID: PMC5741522 DOI: 10.1177/1099800417748759] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
INTRODUCTION Experiences of racial discrimination have been associated with poor health outcomes. Little is known, however, about how perceived racial discrimination influences DNA methylation (DNAm) among African Americans (AAs). We examined the association of experiences of discrimination with DNAm among AA women in the Intergenerational Impact of Genetic and Psychological Factors on Blood Pressure (InterGEN) study. METHODS The InterGEN study examines the effects of genetic and psychological factors on blood pressure among AA women and their children. Measures include the Major Life Discrimination (MLD) and the Race-Related Events (RES) scales. In the present analysis, we examined discrimination and DNAm at baseline in the InterGEN study. The 850K EPIC Illumina BeadChip was used for evaluating DNAm in this epigenome-wide association study (EWAS). RESULTS One hundred and fifty-two women contributed data for the RES-EWAS analysis and 147 for the MLD-EWAS analysis. Most were 30-39 years old, nonsmokers, had some college education, and had incomes CONCLUSION We observed significant epigenetic associations between disease-associated genes (e.g., schizophrenia, bipolar disorder, and asthma) and perceived discrimination as measured by the MLD Scale. Future health disparities research should include epigenetics in high-risk populations to elucidate functional consequences induced by the psychosocial environment.
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Affiliation(s)
| | - Yunfeng Huang
- 2 Department of Epidemiology, Emory University Rollins School of Public Health, Atlanta, GA, USA
| | - Cindy A Crusto
- 3 Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
| | - Yan V Sun
- 2 Department of Epidemiology, Emory University Rollins School of Public Health, Atlanta, GA, USA
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Zöller T, Attaai A, Potru PS, Ruß T, Spittau B. Aged Mouse Cortical Microglia Display an Activation Profile Suggesting Immunotolerogenic Functions. Int J Mol Sci 2018; 19:E706. [PMID: 29494550 PMCID: PMC5877567 DOI: 10.3390/ijms19030706] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 02/21/2018] [Accepted: 02/25/2018] [Indexed: 12/19/2022] Open
Abstract
Microglia are the resident immune cells of the central nervous system (CNS) and participate in physiological and pathological processes. Their unique developmental nature suggests age-dependent structural and functional impairments that might contribute to neurodegenerative diseases. In the present study, we addressed the age-dependent changes in cortical microglia gene expression patterns and the expression of M1- and M2-like activation markers. Iba1 immunohistochemistry, isolation of cortical microglia followed by fluorescence-activated cell sorting and RNA isolation to analyze transcriptional changes in aged cortical microglia was performed. We provide evidence that aging is associated with decreased numbers of cortical microglia and the establishment of a distinct microglia activation profile including upregulation of Ifi204, Lilrb4, Arhgap, Oas1a, Cd244 and Ildr2. Moreover, flow cytometry revealed that aged cortical microglia express increased levels of Cd206 and Cd36. The data presented in the current study indicate that aged mouse cortical microglia adopt a distinct activation profile, which suggests immunosuppressive and immuno-tolerogenic functions.
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Affiliation(s)
- Tanja Zöller
- Institute for Anatomy and Cell Biology, Department of Molecular Embryology, Faculty of Medicine, University of Freiburg, Freiburg 79104, Germany.
| | - Abdelraheim Attaai
- Institute for Anatomy and Cell Biology, Department of Molecular Embryology, Faculty of Medicine, University of Freiburg, Freiburg 79104, Germany.
- Faculty of Biology, University of Freiburg, Freiburg 79104, Germany.
- Department of Anatomy and Histology, Faculty of Veterinary Medicine, Assiut University, Assiut 71526, Egypt.
| | | | - Tamara Ruß
- Institute of Anatomy, University of Rostock, Rostock 18057, Germany.
| | - Björn Spittau
- Institute for Anatomy and Cell Biology, Department of Molecular Embryology, Faculty of Medicine, University of Freiburg, Freiburg 79104, Germany.
- Institute of Anatomy, University of Rostock, Rostock 18057, Germany.
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23
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Abstract
The key regulatory enzymes of glycogenolysis are phosphorylase kinase, a hetero-oligomer with four different types of subunits, and glycogen phosphorylase, a homodimer. Both enzymes are activated by phosphorylation and small ligands, and both enzymes have distinct isoforms that are predominantly expressed in muscle, liver, or brain; however, whole-transcriptome high-throughput sequencing analyses show that in brain both of these enzymes are likely composed of subunit isoforms representing all three tissues. This Minireview examines the regulatory properties of the isoforms of these two enzymes expressed in the three tissues, focusing on their potential regulatory similarities and differences. Additionally, the activity, structure, and regulation of the remaining enzyme necessary for glycogenolysis, glycogen-debranching enzyme, are also reviewed.
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Affiliation(s)
- Owen W Nadeau
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas 66160-7421
| | - Joseph D Fontes
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas 66160-7421
| | - Gerald M Carlson
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas 66160-7421.
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24
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Maffioli E, Schulte C, Nonnis S, Grassi Scalvini F, Piazzoni C, Lenardi C, Negri A, Milani P, Tedeschi G. Proteomic Dissection of Nanotopography-Sensitive Mechanotransductive Signaling Hubs that Foster Neuronal Differentiation in PC12 Cells. Front Cell Neurosci 2018; 11:417. [PMID: 29354032 PMCID: PMC5758595 DOI: 10.3389/fncel.2017.00417] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 12/12/2017] [Indexed: 12/11/2022] Open
Abstract
Neuronal cells are competent in precisely sensing nanotopographical features of their microenvironment. The perceived microenvironmental information will be “interpreted” by mechanotransductive processes and impacts on neuronal functioning and differentiation. Attempts to influence neuronal differentiation by engineering substrates that mimic appropriate extracellular matrix (ECM) topographies are hampered by the fact that profound details of mechanosensing/-transduction complexity remain elusive. Introducing omics methods into these biomaterial approaches has the potential to provide a deeper insight into the molecular processes and signaling cascades underlying mechanosensing/-transduction but their exigence in cellular material is often opposed by technical limitations of major substrate top-down fabrication methods. Supersonic cluster beam deposition (SCBD) allows instead the bottom-up fabrication of nanostructured substrates over large areas characterized by a quantitatively controllable ECM-like nanoroughness that has been recently shown to foster neuron differentiation and maturation. Exploiting this capacity of SCBD, we challenged mechanosensing/-transduction and differentiative behavior of neuron-like PC12 cells with diverse nanotopographies and/or changes of their biomechanical status, and analyzed their phosphoproteomic profiles in these settings. Versatile proteins that can be associated to significant processes along the mechanotransductive signal sequence, i.e., cell/cell interaction, glycocalyx and ECM, membrane/f-actin linkage and integrin activation, cell/substrate interaction, integrin adhesion complex, actomyosin organization/cellular mechanics, nuclear organization, and transcriptional regulation, were affected. The phosphoproteomic data suggested furthermore an involvement of ILK, mTOR, Wnt, and calcium signaling in these nanotopography- and/or cell mechanics-related processes. Altogether, potential nanotopography-sensitive mechanotransductive signaling hubs participating in neuronal differentiation were dissected.
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Affiliation(s)
- Elisa Maffioli
- Department of Veterinary Medicine, Università degli Studi di Milano, Milan, Italy
| | - Carsten Schulte
- Centre for Nanostructured Materials and Interfaces, Università degli Studi di Milano, Milan, Italy.,Fondazione Filarete, Milan, Italy
| | - Simona Nonnis
- Department of Veterinary Medicine, Università degli Studi di Milano, Milan, Italy.,Fondazione Filarete, Milan, Italy
| | - Francesca Grassi Scalvini
- Department of Veterinary Medicine, Università degli Studi di Milano, Milan, Italy.,Fondazione Filarete, Milan, Italy
| | - Claudio Piazzoni
- Centre for Nanostructured Materials and Interfaces, Università degli Studi di Milano, Milan, Italy
| | - Cristina Lenardi
- Centre for Nanostructured Materials and Interfaces, Università degli Studi di Milano, Milan, Italy
| | - Armando Negri
- Department of Veterinary Medicine, Università degli Studi di Milano, Milan, Italy.,Fondazione Filarete, Milan, Italy
| | - Paolo Milani
- Centre for Nanostructured Materials and Interfaces, Università degli Studi di Milano, Milan, Italy
| | - Gabriella Tedeschi
- Department of Veterinary Medicine, Università degli Studi di Milano, Milan, Italy.,Fondazione Filarete, Milan, Italy
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25
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Liu X, Su P, Lu L, Feng Z, Wang H, Zhou J. Function of FEZF1 during early neural differentiation of human embryonic stem cells. SCIENCE CHINA-LIFE SCIENCES 2018; 61:35-45. [PMID: 29318501 DOI: 10.1007/s11427-017-9155-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 11/19/2017] [Indexed: 12/14/2022]
Abstract
The understanding of the mechanism underlying human neural development has been hampered due to lack of a cellular system and complicated ethical issues. Human embryonic stem cells (hESCs) provide an invaluable model for dissecting human development because of unlimited self-renewal and the capacity to differentiate into nearly all cell types in the human body. In this study, using a chemical defined neural induction protocol and molecular profiling, we identified Fez family zinc finger 1 (FEZF1) as a potential regulator of early human neural development. FEZF1 is rapidly up-regulated during neural differentiation in hESCs and expressed before PAX6, a well-established marker of early human neural induction. We generated FEZF1-knockout H1 hESC lines using CRISPR-CAS9 technology and found that depletion of FEZF1 abrogates neural differentiation of hESCs. Moreover, loss of FEZF1 impairs the pluripotency exit of hESCs during neural specification, which partially explains the neural induction defect caused by FEZF1 deletion. However, enforced expression of FEZF1 itself fails to drive neural differentiation in hESCs, suggesting that FEZF1 is necessary but not sufficient for neural differentiation from hESCs. Taken together, our findings identify one of the earliest regulators expressed upon neural induction and provide insight into early neural development in human.
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Affiliation(s)
- Xin Liu
- State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, 300020, China
- Center for Stem Cell Medicine, Chinese Academy of Medical Sciences & Department of Stem Cells and Regenerative Medicine, Peking Union Medical College, Tianjin, 300000, China
| | - Pei Su
- State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, 300020, China
- Center for Stem Cell Medicine, Chinese Academy of Medical Sciences & Department of Stem Cells and Regenerative Medicine, Peking Union Medical College, Tianjin, 300000, China
| | - Lisha Lu
- State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, 300020, China
- Center for Stem Cell Medicine, Chinese Academy of Medical Sciences & Department of Stem Cells and Regenerative Medicine, Peking Union Medical College, Tianjin, 300000, China
| | - Zicen Feng
- State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, 300020, China
- Center for Stem Cell Medicine, Chinese Academy of Medical Sciences & Department of Stem Cells and Regenerative Medicine, Peking Union Medical College, Tianjin, 300000, China
| | - Hongtao Wang
- State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, 300020, China.
- Center for Stem Cell Medicine, Chinese Academy of Medical Sciences & Department of Stem Cells and Regenerative Medicine, Peking Union Medical College, Tianjin, 300000, China.
| | - Jiaxi Zhou
- State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, 300020, China.
- Center for Stem Cell Medicine, Chinese Academy of Medical Sciences & Department of Stem Cells and Regenerative Medicine, Peking Union Medical College, Tianjin, 300000, China.
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26
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Mib1 contributes to persistent directional cell migration by regulating the Ctnnd1-Rac1 pathway. Proc Natl Acad Sci U S A 2017; 114:E9280-E9289. [PMID: 29078376 DOI: 10.1073/pnas.1712560114] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Persistent directional cell migration is involved in animal development and diseases. The small GTPase Rac1 is involved in F-actin and focal adhesion dynamics. Local Rac1 activity is required for persistent directional migration, whereas global, hyperactivated Rac1 enhances random cell migration. Therefore, precise control of Rac1 activity is important for proper directional cell migration. However, the molecular mechanism underlying the regulation of Rac1 activity in persistent directional cell migration is not fully understood. Here, we show that the ubiquitin ligase mind bomb 1 (Mib1) is involved in persistent directional cell migration. We found that knockdown of MIB1 led to an increase in random cell migration in HeLa cells in a wound-closure assay. Furthermore, we explored novel Mib1 substrates for cell migration and found that Mib1 ubiquitinates Ctnnd1. Mib1-mediated ubiquitination of Ctnnd1 K547 attenuated Rac1 activation in cultured cells. In addition, we found that posterior lateral line primordium cells in the zebrafish mib1ta52b mutant showed increased random migration and loss of directional F-actin-based protrusion formation. Knockdown of Ctnnd1 partially rescued posterior lateral line primordium cell migration defects in the mib1ta52b mutant. Taken together, our data suggest that Mib1 plays an important role in cell migration and that persistent directional cell migration is regulated, at least in part, by the Mib1-Ctnnd1-Rac1 pathway.
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