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Dominicci-Cotto C, Vazquez M, Marie B. The Wingless planar cell polarity pathway is essential for optimal activity-dependent synaptic plasticity. Front Synaptic Neurosci 2024; 16:1322771. [PMID: 38633293 PMCID: PMC11021733 DOI: 10.3389/fnsyn.2024.1322771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 03/18/2024] [Indexed: 04/19/2024] Open
Abstract
From fly to man, the Wingless (Wg)/Wnt signaling molecule is essential for both the stability and plasticity of the nervous system. The Drosophila neuromuscular junction (NMJ) has proven to be a useful system for deciphering the role of Wg in directing activity-dependent synaptic plasticity (ADSP), which, in the motoneuron, has been shown to be dependent on both the canonical and the noncanonical calcium Wg pathways. Here we show that the noncanonical planar cell polarity (PCP) pathway is an essential component of the Wg signaling system controlling plasticity at the motoneuron synapse. We present evidence that disturbing the PCP pathway leads to a perturbation in ADSP. We first show that a PCP-specific allele of disheveled (dsh) affects the de novo synaptic structures produced during ADSP. We then show that the Rho GTPases downstream of Dsh in the PCP pathway are also involved in regulating the morphological changes that take place after repeated stimulation. Finally, we show that Jun kinase is essential for this phenomenon, whereas we found no indication of the involvement of the transcription factor complex AP1 (Jun/Fos). This work shows the involvement of the neuronal PCP signaling pathway in supporting ADSP. Because we find that AP1 mutants can perform ADSP adequately, we hypothesize that, upon Wg activation, the Rho GTPases and Jun kinase are involved locally at the synapse, in instructing cytoskeletal dynamics responsible for the appearance of the morphological changes occurring during ADSP.
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Affiliation(s)
- Carihann Dominicci-Cotto
- Department of Anatomy and Neurobiology, Medical Sciences Campus, University of Puerto Rico, San Juan, PR, United States
- Institute of Neurobiology, Medical Sciences Campus, University of Puerto Rico, San Juan, PR, United States
| | - Mariam Vazquez
- Institute of Neurobiology, Medical Sciences Campus, University of Puerto Rico, San Juan, PR, United States
- Molecular Sciences Research Center, University of Puerto Rico, San Juan, PR, United States
| | - Bruno Marie
- Department of Anatomy and Neurobiology, Medical Sciences Campus, University of Puerto Rico, San Juan, PR, United States
- Institute of Neurobiology, Medical Sciences Campus, University of Puerto Rico, San Juan, PR, United States
- Molecular Sciences Research Center, University of Puerto Rico, San Juan, PR, United States
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2
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Ren F, Si Q, Sui Y. Diagnostic significance and potential function of miR-320d in schizophrenia. Psychiatr Genet 2024; 34:61-67. [PMID: 38441082 DOI: 10.1097/ypg.0000000000000365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
OBJECTIVES Schizophrenia is a chronic brain disorder and needs objective diagnostic biomarkers. MicroRNAs are highly expressed in the nervous system. The study investigated the expression and clinical values of serum miR-320d in schizophrenia patients. In addition, the underlying mechanism was preliminarily examined via bioinformatic analysis. MATERIALS AND METHODS Serum samples were collected from 57 patients with first-episode schizophrenia and 62 healthy controls. The cognitive function of patients was assessed via Measurement and Treatment Research to Improve Cognition in Schizophrenia Consensus Cognitive Battery (MCCB) consisting of seven domains. Serum miR-320d levels were tested via qRT-PCR. The miRNA target predictions were obtained from Target Scan, and annotated through Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. RESULTS Based on the GSE167630 dataset, downregulated serum miR-320d in schizophrenia was identified, which was determined in the serum of schizophrenia patients. Serum miR-320d presented a conspicuous relationship with MCCB score in both the control group and the schizophrenia group. After adjusting for age, sex, BMI, and education, serum miR-320d was still independently related to the occurrence of schizophrenia. It can identify schizophrenia cases from healthy ones with an AUC of 0.931. The Go enrichment analysis indicated that the target genes were mainly enriched in homophilic cell adhesion and cell-cell adhesion via plasma-membrane adhesion molecules, and GTPase activity and guanosine diphosphate (GDP) binding. Rap1 signaling pathway was enriched via KEGG analysis. CONCLUSION Serum miR-320d can be taken as a candidate marker for the diagnosis of schizophrenia. Its regulatory role in neuronal cell adhesion and Rap1 signaling pathway might be the potential underlying mechanism of miR-320d in schizophrenia.
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Affiliation(s)
- Fangfang Ren
- Department of Psychiatry, Nanjing Brain Hospital, Nanjing, China
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3
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Shimada M, Omae Y, Kakita A, Gabdulkhaev R, Hitomi Y, Miyagawa T, Honda M, Fujimoto A, Tokunaga K. Identification of region-specific gene isoforms in the human brain using long-read transcriptome sequencing. SCIENCE ADVANCES 2024; 10:eadj5279. [PMID: 38266094 PMCID: PMC10807796 DOI: 10.1126/sciadv.adj5279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 12/21/2023] [Indexed: 01/26/2024]
Abstract
In neurological and neuropsychiatric diseases, different brain regions are affected, and differences in gene expression patterns could potentially explain this mechanism. However, limited studies have precisely explored gene expression in different regions of the human brain. In this study, we performed long-read RNA sequencing on three different brain regions of the same individuals: the cerebellum, hypothalamus, and temporal cortex. Despite stringent filtering criteria excluding isoforms predicted to be artifacts, over half of the isoforms expressed in multiple samples across multiple regions were found to be unregistered in the GENCODE reference. We then especially focused on genes with different major isoforms in each brain region, even with similar overall expression levels, and identified that many of such genes including GAS7 might have distinct roles in dendritic spine and neuronal formation in each region. We also found that DNA methylation might, in part, drive different isoform expressions in different regions. These findings highlight the significance of analyzing isoforms expressed in disease-relevant sites.
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Affiliation(s)
- Mihoko Shimada
- Genome Medical Science Project (Toyama), National Center for Global Health and Medicine (NCGM), Tokyo, Japan
- Center for Clinical Sciences, National Center for Global Health and Medicine (NCGM), Tokyo, Japan
- Sleep Disorders Project, Department of Psychiatry and Behavioral Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Yosuke Omae
- Genome Medical Science Project (Toyama), National Center for Global Health and Medicine (NCGM), Tokyo, Japan
| | - Akiyoshi Kakita
- Department of Pathology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Ramil Gabdulkhaev
- Department of Pathology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Yuki Hitomi
- Department of Human Genetics, Research Institute, National Center for Global Health and Medicine (NCGM), Tokyo, Japan
| | - Taku Miyagawa
- Sleep Disorders Project, Department of Psychiatry and Behavioral Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Makoto Honda
- Sleep Disorders Project, Department of Psychiatry and Behavioral Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
- Japan Somnology Center and Seiwa Hospital, Institute of Neuropsychiatry, Tokyo, Japan
| | - Akihiro Fujimoto
- Department of Human Genetics, Graduate School of Medicine, the University of Tokyo, Tokyo, Japan
| | - Katsushi Tokunaga
- Genome Medical Science Project (Toyama), National Center for Global Health and Medicine (NCGM), Tokyo, Japan
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4
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Zhou F, Ouyang L, Li Q, Yang S, Liu S, Yu H, Jia Q, Rao S, Xie J, Du G, Feng C, Fan G. Hippocampal LIMK1-mediated Structural Synaptic Plasticity in Neurobehavioral Deficits Induced by a Low-dose Heavy Metal Mixture. Mol Neurobiol 2023; 60:6029-6042. [PMID: 37407880 DOI: 10.1007/s12035-023-03458-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Accepted: 06/18/2023] [Indexed: 07/07/2023]
Abstract
Humans are commonly exposed to the representative neurotoxic heavy metals lead (Pb), cadmium (Cd), and mercury (Hg). These three substances can be detected simultaneously in the blood of the general population. We have previously shown that a low-dose mixture of these heavy metals induces rat learning and memory impairment at human exposure levels, but the pathogenic mechanism is still unclear. LIM kinase 1 (LIMK1) plays a critical role in orchestrating synaptic plasticity during brain function and dysfunction. Hence, we investigated the role of LIMK1 activity in low-dose heavy metal mixture-induced neurobehavioral deficits and structural synaptic plasticity disorders. Our results showed that heavy metal mixture exposure altered rat fear responses and spatial learning at general population exposure levels and that these alterations were accompanied by downregulation of LIMK1 phosphorylation and structural synaptic plasticity dysfunction in rat hippocampal tissues and cultured hippocampal neurons. In addition, upregulation of LIMK1 phosphorylation attenuated heavy metal mixture-induced structural synaptic plasticity, dendritic actin dynamics, and cofilin phosphorylation damage. The potent LIMK1 inhibitor BMS-5 yielded similar results induced by heavy metal mixture exposure and aggravated these impairments. Our findings demonstrate that LIMK1 plays a crucial role in neurobehavioral deficits induced by low-dose heavy metal mixture exposure by suppressing structural synaptic plasticity.
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Affiliation(s)
- Fankun Zhou
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, BaYi Road 461, Nanchang, 330006, P.R. China
- Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang, 330006, P.R. China
| | - Lu Ouyang
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, BaYi Road 461, Nanchang, 330006, P.R. China
- Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang, 330006, P.R. China
| | - Qi Li
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, BaYi Road 461, Nanchang, 330006, P.R. China
- Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang, 330006, P.R. China
| | - Shuo Yang
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, BaYi Road 461, Nanchang, 330006, P.R. China
- Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang, 330006, P.R. China
| | - Sisi Liu
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, BaYi Road 461, Nanchang, 330006, P.R. China
- Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang, 330006, P.R. China
| | - Han Yu
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, BaYi Road 461, Nanchang, 330006, P.R. China
- Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang, 330006, P.R. China
| | - Qiyue Jia
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, BaYi Road 461, Nanchang, 330006, P.R. China
- Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang, 330006, P.R. China
| | - Shaoqi Rao
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, BaYi Road 461, Nanchang, 330006, P.R. China
- Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang, 330006, P.R. China
| | - Jie Xie
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, BaYi Road 461, Nanchang, 330006, P.R. China
- Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang, 330006, P.R. China
| | - Guihua Du
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, BaYi Road 461, Nanchang, 330006, P.R. China
- Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang, 330006, P.R. China
| | - Chang Feng
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, BaYi Road 461, Nanchang, 330006, P.R. China
- Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang, 330006, P.R. China
| | - Guangqin Fan
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, BaYi Road 461, Nanchang, 330006, P.R. China.
- Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang, 330006, P.R. China.
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Zhou F, Ouyang L, Xie J, Liu S, Li Q, Yang S, Li J, Su R, Rao S, Yan L, Wan X, Cheng H, Liu P, Li L, Zhu Y, Du G, Feng C, Fan G. Co-exposure to low-dose lead, cadmium, and mercury promotes memory deficits in rats: Insights from the dynamics of dendritic spine pruning in brain development. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 264:115425. [PMID: 37660527 DOI: 10.1016/j.ecoenv.2023.115425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 08/26/2023] [Accepted: 08/30/2023] [Indexed: 09/05/2023]
Abstract
Lead (Pb), cadmium (Cd), and mercury (Hg) are environmentally toxic heavy metals that can be simultaneously detected at low levels in the blood of the general population. Although our previous studies have demonstrated neurodevelopmental toxicity upon co-exposure to these heavy metals at these low levels, the precise mechanisms remain largely unknown. Dendritic spines are the structural foundation of memory and undergo significant dynamic changes during development. This study focused on the dynamics of dendritic spines during brain development following Pb, Cd, and Hg co-exposure-induced memory impairment. First, the dynamic characteristics of dendritic spines in the prefrontal cortex were observed throughout the life cycle of normal rats. We observed that dendritic spines increased rapidly from birth to their peak value at weaning, followed by significant pruning and a decrease during adolescence. Dendritic spines tended to be stable until their loss in old age. Subsequently, a rat model of low-dose Pb, Cd, and Hg co-exposure from embryo to adolescence was established. The results showed that exposure to low doses of heavy metals equivalent to those detected in the blood of the general population impaired spatial memory and altered the dynamics of dendritic spine pruning from weaning to adolescence. Proteomic analysis of brain and blood samples suggested that differentially expressed proteins upon heavy metal exposure were enriched in dendritic spine-related cytoskeletal regulation and axon guidance signaling pathways and that cofilin was enriched in both of these pathways. Further experiments confirmed that heavy metal exposure altered actin cytoskeleton dynamics and disturbed the dendritic spine pruning-related LIM domain kinase 1-cofilin pathway in the rat prefrontal cortex. Our findings demonstrate that low-dose Pb, Cd, and Hg co-exposure may promote memory impairment by perturbing dendritic spine dynamics through dendritic spine pruning-related signaling pathways.
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Affiliation(s)
- Fankun Zhou
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Lu Ouyang
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Jie Xie
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Sisi Liu
- Jiangxi Academy of Medical Science, Nanchang 330006, PR China
| | - Qi Li
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Shuo Yang
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Jiajun Li
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Rui Su
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Shaoqi Rao
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Lingyu Yan
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Xin Wan
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Hui Cheng
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Peishan Liu
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Lingling Li
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Yanhui Zhu
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Guihua Du
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Chang Feng
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China
| | - Guangqin Fan
- Department of Occupational Health and Toxicology, School of Public Health, Nanchang University, Nanchang 330006, PR China; Jiangxi Provincial Key Laboratory of Preventive Medicine, Nanchang University, Nanchang 330006, PR China.
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Bjornson KJ, Vanderplow AM, Yang Y, Anderson DR, Kermath BA, Cahill ME. Stress-mediated dysregulation of the Rap1 small GTPase impairs hippocampal structure and function. iScience 2023; 26:107566. [PMID: 37664580 PMCID: PMC10470260 DOI: 10.1016/j.isci.2023.107566] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 05/15/2023] [Accepted: 08/02/2023] [Indexed: 09/05/2023] Open
Abstract
The effects of repeated stress on cognitive impairment are thought to be mediated, at least in part, by reductions in the stability of dendritic spines in brain regions critical for proper learning and memory, including the hippocampus. Small GTPases are particularly potent regulators of dendritic spine formation, stability, and morphology in hippocampal neurons. Through the use of small GTPase protein profiling in mice, we identify increased levels of synaptic Rap1 in the hippocampal CA3 region in response to escalating, intermittent stress. We then demonstrate that increased Rap1 in the CA3 is sufficient in and of itself to produce stress-relevant dendritic spine and cognitive phenotypes. Further, using super-resolution imaging, we investigate how the pattern of Rap1 trafficking to synapses likely underlies its effects on the stability of select dendritic spine subtypes. These findings illuminate the involvement of aberrant Rap1 regulation in the hippocampus in contributing to the psychobiological effects of stress.
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Affiliation(s)
- Kathryn J. Bjornson
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Amanda M. Vanderplow
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Yezi Yang
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Danielle R. Anderson
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Bailey A. Kermath
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Michael E. Cahill
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI 53706, USA
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Dobrigna M, Poëa-Guyon S, Rousseau V, Vincent A, Toutain A, Barnier JV. The molecular basis of p21-activated kinase-associated neurodevelopmental disorders: From genotype to phenotype. Front Neurosci 2023; 17:1123784. [PMID: 36937657 PMCID: PMC10017488 DOI: 10.3389/fnins.2023.1123784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 02/13/2023] [Indexed: 03/06/2023] Open
Abstract
Although the identification of numerous genes involved in neurodevelopmental disorders (NDDs) has reshaped our understanding of their etiology, there are still major obstacles in the way of developing therapeutic solutions for intellectual disability (ID) and other NDDs. These include extensive clinical and genetic heterogeneity, rarity of recurrent pathogenic variants, and comorbidity with other psychiatric traits. Moreover, a large intragenic mutational landscape is at play in some NDDs, leading to a broad range of clinical symptoms. Such diversity of symptoms is due to the different effects DNA variations have on protein functions and their impacts on downstream biological processes. The type of functional alterations, such as loss or gain of function, and interference with signaling pathways, has yet to be correlated with clinical symptoms for most genes. This review aims at discussing our current understanding of how the molecular changes of group I p21-activated kinases (PAK1, 2 and 3), which are essential actors of brain development and function; contribute to a broad clinical spectrum of NDDs. Identifying differences in PAK structure, regulation and spatio-temporal expression may help understanding the specific functions of each group I PAK. Deciphering how each variation type affects these parameters will help uncover the mechanisms underlying mutation pathogenicity. This is a prerequisite for the development of personalized therapeutic approaches.
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Affiliation(s)
- Manon Dobrigna
- Institut des Neurosciences Paris-Saclay, UMR 9197, CNRS, Université Paris-Saclay, Saclay, France
| | - Sandrine Poëa-Guyon
- Institut des Neurosciences Paris-Saclay, UMR 9197, CNRS, Université Paris-Saclay, Saclay, France
| | - Véronique Rousseau
- Institut des Neurosciences Paris-Saclay, UMR 9197, CNRS, Université Paris-Saclay, Saclay, France
| | - Aline Vincent
- Department of Genetics, EA7450 BioTARGen, University Hospital of Caen, Caen, France
| | - Annick Toutain
- Department of Genetics, University Hospital of Tours, UMR 1253, iBrain, Université de Tours, INSERM, Tours, France
| | - Jean-Vianney Barnier
- Institut des Neurosciences Paris-Saclay, UMR 9197, CNRS, Université Paris-Saclay, Saclay, France
- *Correspondence: Jean-Vianney Barnier,
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Rodríguez-Urgellés E, Rodríguez-Navarro I, Ballasch I, Del Toro D, Del Castillo I, Brito V, Alberch J, Giralt A. Postnatal Foxp2 regulates early psychiatric-like phenotypes and associated molecular alterations in the R6/1 transgenic mouse model of Huntington's disease. Neurobiol Dis 2022; 173:105854. [PMID: 36029989 DOI: 10.1016/j.nbd.2022.105854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 08/11/2022] [Accepted: 08/23/2022] [Indexed: 11/16/2022] Open
Abstract
Huntington's Disease (HD) is a devastating disorder characterized by a triad of motor, psychiatric and cognitive manifestations. Psychiatric and emotional symptoms appear at early stages of the disease which are consistently described by patients and caregivers among the most disabling. Here, we show for the first time that Foxp2 is strongly associated with some psychiatric-like disturbances in the R6/1 mouse model of HD. First, 4-week-old (juvenile) R6/1 mice behavioral phenotype was characterized by an increased impulsive-like behavior and less aggressive-like behavior. In this line, we identified an early striatal downregulation of Foxp2 protein starting as soon as at postnatal day 15 that could explain such deficiencies. Interestingly, the rescue of striatal Foxp2 levels from postnatal stages completely reverted the impulsivity-phenotype and partially the social impairments concomitant with a rescue of dendritic spine pathology. A mass spectrometry study indicated that the rescue of spine loss was associated with an improvement of several altered proteins related with cytoskeleton dynamics. Finally, we reproduced and mimicked the impulsivity and social deficits in wild type mice by reducing their striatal Foxp2 expression from postnatal stages. Overall, these results imply that early postnatal reduction of Foxp2 might contribute to the appearance of some of the early psychiatric symptoms in HD.
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Affiliation(s)
- Ened Rodríguez-Urgellés
- Departament de Biomedicina, Facultat de Medicina, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Irene Rodríguez-Navarro
- Departament de Biomedicina, Facultat de Medicina, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Iván Ballasch
- Departament de Biomedicina, Facultat de Medicina, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Daniel Del Toro
- Departament de Biomedicina, Facultat de Medicina, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Ignacio Del Castillo
- Departament de Biomedicina, Facultat de Medicina, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Verónica Brito
- Departament de Biomedicina, Facultat de Medicina, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Jordi Alberch
- Departament de Biomedicina, Facultat de Medicina, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain; Production and Validation Center of Advanced Therapies (Creatio), Faculty of Medicine and Health Science, University of Barcelona, 08036 Barcelona, Spain.
| | - Albert Giralt
- Departament de Biomedicina, Facultat de Medicina, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain; Production and Validation Center of Advanced Therapies (Creatio), Faculty of Medicine and Health Science, University of Barcelona, 08036 Barcelona, Spain.
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Beamish SB, Frick KM. A Putative Role for Ubiquitin-Proteasome Signaling in Estrogenic Memory Regulation. Front Behav Neurosci 2022; 15:807215. [PMID: 35145382 PMCID: PMC8821141 DOI: 10.3389/fnbeh.2021.807215] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 12/20/2021] [Indexed: 12/31/2022] Open
Abstract
Sex steroid hormones such as 17β-estradiol (E2) are critical neuromodulators of hippocampal synaptic plasticity and hippocampus-dependent memory in both males and females. However, the mechanisms through which E2 regulates memory formation in both sexes remain unclear. Research to date suggests that E2 regulates hippocampus-dependent memory by activating numerous cell-signaling cascades to promote the synthesis of proteins that support structural changes at hippocampal synapses. However, this work has largely overlooked the equally important contributions of protein degradation mediated by the ubiquitin proteasome system (UPS) in remodeling the synapse. Despite being critically implicated in synaptic plasticity and successful formation of long-term memories, it remains unclear whether protein degradation mediated by the UPS is necessary for E2 to exert its beneficial effects on hippocampal plasticity and memory formation. The present article provides an overview of the receptor and signaling mechanisms so far identified as critical for regulating hippocampal E2 and UPS function in males and females, with a particular emphasis on the ways in which these mechanisms overlap to support structural integrity and protein composition of hippocampal synapses. We argue that the high degree of correspondence between E2 and UPS activity warrants additional study to examine the contributions of ubiquitin-mediated protein degradation in regulating the effects of sex steroid hormones on cognition.
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10
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The Rap1 small GTPase is a critical mediator of the effects of stress on prefrontal cortical dysfunction. Mol Psychiatry 2021; 26:3223-3239. [PMID: 32651478 DOI: 10.1038/s41380-020-0835-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 06/23/2020] [Accepted: 06/30/2020] [Indexed: 02/06/2023]
Abstract
The neural molecular and biochemical response to stress is a distinct physiological process, and multiple lines of evidence indicate that the prefrontal cortex (PFC) is particularly sensitive to, and afflicted by, exposure to stress. Largely through this PFC dysfunction, stress has a characterized role in facilitating cognitive impairment, which is often dissociable from its effects on non-cognitive behaviors. The Rap1 small GTPase pathway has emerged as a commonly disrupted intracellular target in neuropsychiatric conditions, whether it be via alterations in Rap1 expression or through alterations in the expression of direct and specific upstream Rap1 activators and inhibitors. Here we demonstrate that escalating, intermittent stress increases Rap1 in mouse PFC synapses, results in cognitive impairments, and reduces the preponderance of mature dendritic spines in PFC neurons. Using viral-mediated gene transfer, we reveal that the hyper-induction of Rap1 in the PFC is sufficient to drive stress-relevant cognitive and synaptic phenotypes. These findings point to Rap1 as a critical mediator of stress-driven neuronal and behavioral pathology and highlight a previously unrecognized involvement for Rap1 in novelty-driven PFC engagement.
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11
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Zheng K, Hu F, Zhou Y, Zhang J, Zheng J, Lai C, Xiong W, Cui K, Hu YZ, Han ZT, Zhang HH, Chen JG, Man HY, Liu D, Lu Y, Zhu LQ. miR-135a-5p mediates memory and synaptic impairments via the Rock2/Adducin1 signaling pathway in a mouse model of Alzheimer's disease. Nat Commun 2021; 12:1903. [PMID: 33771994 PMCID: PMC7998005 DOI: 10.1038/s41467-021-22196-y] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 02/25/2021] [Indexed: 12/13/2022] Open
Abstract
Aberrant regulation of microRNAs (miRNAs) has been implicated in the pathogenesis of Alzheimer's disease (AD), but most abnormally expressed miRNAs found in AD are not regulated by synaptic activity. Here we report that dysfunction of miR-135a-5p/Rock2/Add1 results in memory/synaptic disorder in a mouse model of AD. miR-135a-5p levels are significantly reduced in excitatory hippocampal neurons of AD model mice. This decrease is tau dependent and mediated by Foxd3. Inhibition of miR-135a-5p leads to synaptic disorder and memory impairments. Furthermore, excess Rock2 levels caused by loss of miR-135a-5p plays an important role in the synaptic disorder of AD via phosphorylation of Ser726 on adducin 1 (Add1). Blocking the phosphorylation of Ser726 on Add1 with a membrane-permeable peptide effectively rescues the memory impairments in AD mice. Taken together, these findings demonstrate that synaptic-related miR-135a-5p mediates synaptic/memory deficits in AD via the Rock2/Add1 signaling pathway, illuminating a potential therapeutic strategy for AD.
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Affiliation(s)
- Kai Zheng
- Department of Geriatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Fan Hu
- Department of Pathophysiology, Key Lab of Neurological Disorder of Education Ministry, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P. R. China
| | - Yang Zhou
- Department of Pathophysiology, Key Lab of Neurological Disorder of Education Ministry, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P. R. China
| | - Juan Zhang
- Department of Pathophysiology, Key Lab of Neurological Disorder of Education Ministry, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P. R. China
| | - Jie Zheng
- Department of Geriatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chuan Lai
- Department of Pathophysiology, Key Lab of Neurological Disorder of Education Ministry, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P. R. China
| | - Wan Xiong
- Department of Pathophysiology, Key Lab of Neurological Disorder of Education Ministry, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P. R. China
| | - Ke Cui
- Department of Pathophysiology, Key Lab of Neurological Disorder of Education Ministry, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P. R. China
| | - Ya-Zhuo Hu
- Beijing Key Laboratory of Aging and Geriatrics, National Clinical Research Center for Geriatric Disease, Institute of Geriatrics, Chinese PLA General Hospital and Chinese PLA Medical Academy, Beijing, P. R. China
| | - Zhi-Tao Han
- Beijing Key Laboratory of Aging and Geriatrics, National Clinical Research Center for Geriatric Disease, Institute of Geriatrics, Chinese PLA General Hospital and Chinese PLA Medical Academy, Beijing, P. R. China
| | - Hong-Hong Zhang
- Beijing Key Laboratory of Aging and Geriatrics, National Clinical Research Center for Geriatric Disease, Institute of Geriatrics, Chinese PLA General Hospital and Chinese PLA Medical Academy, Beijing, P. R. China
| | - Jian-Guo Chen
- The Institute of Brain Research, Collaborative Innovation Center for Brain Science, Huazhong University of Science and Technology, Wuhan, P. R. China
| | - Heng-Ye Man
- Department of Biology, Boston University, Boston, MA, USA
| | - Dan Liu
- The Institute of Brain Research, Collaborative Innovation Center for Brain Science, Huazhong University of Science and Technology, Wuhan, P. R. China
| | - Youming Lu
- The Institute of Brain Research, Collaborative Innovation Center for Brain Science, Huazhong University of Science and Technology, Wuhan, P. R. China.
| | - Ling-Qiang Zhu
- Department of Pathophysiology, Key Lab of Neurological Disorder of Education Ministry, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P. R. China.
- The Institute of Brain Research, Collaborative Innovation Center for Brain Science, Huazhong University of Science and Technology, Wuhan, P. R. China.
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12
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Kermath BA, Vanderplow AM, Cahill ME. Dysregulated Prefrontal Cortical RhoA Signal Transduction in Bipolar Disorder with Psychosis: New Implications for Disease Pathophysiology. Cereb Cortex 2021; 30:59-71. [PMID: 31220216 DOI: 10.1093/cercor/bhz070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
While research has identified alterations in dorsolateral prefrontal cortical function as a key factor to the etiology of bipolar disorder, few studies have uncovered robust changes in protein signal transduction pathways in this disorder. Given the direct relevance of protein-based expressional alterations to cellular functions and because many of the key regulatory mechanisms for the disease pathogenesis likely include alterations in protein activity rather than changes in expression alone, the identification of alterations in discrete signal transduction pathways in bipolar disorder would have broad implications for understanding the disease pathophysiology. As prior microarray data point to a previously unrecognized involvement of the RhoA network in bipolar disorder, here we investigate the protein expression and activity of key components of a RhoA signal transduction pathway in dorsolateral prefrontal cortical homogenates from subjects with bipolar disorder. The results of this investigation implicate overactivation of prefrontal cortical RhoA signaling in specific subtypes of bipolar disorder. The specificity of these findings is demonstrated by a lack of comparable changes in schizophrenia; however, our findings do identify convergence between both disorders at the level of activity-mediated actin cytoskeletal regulation. These findings have implications for understanding the altered cortical synaptic connectivity of bipolar disorder.
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Affiliation(s)
- Bailey A Kermath
- Department of Comparative Biosciences, University of Wisconsin at Madison, Madison, WI, USA
| | - Amanda M Vanderplow
- Department of Comparative Biosciences, University of Wisconsin at Madison, Madison, WI, USA
| | - Michael E Cahill
- Department of Comparative Biosciences, University of Wisconsin at Madison, Madison, WI, USA
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13
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Alexander CJ, Barzik M, Fujiwara I, Remmert K, Wang YX, Petralia RS, Friedman TB, Hammer JA. Myosin 18Aα targets the guanine nucleotide exchange factor β-Pix to the dendritic spines of cerebellar Purkinje neurons and promotes spine maturation. FASEB J 2021; 35:e21092. [PMID: 33378124 PMCID: PMC8357457 DOI: 10.1096/fj.202001449r] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 08/24/2020] [Accepted: 09/22/2020] [Indexed: 12/13/2022]
Abstract
Myosin 18Aα is a myosin 2-like protein containing unique N- and C-terminal protein interaction domains that co-assembles with myosin 2. One protein known to bind to myosin 18Aα is β-Pix, a guanine nucleotide exchange factor (GEF) for Rac1 and Cdc42 that has been shown to promote dendritic spine maturation by activating the assembly of actin and myosin filaments in spines. Here, we show that myosin 18A⍺ concentrates in the spines of cerebellar Purkinje neurons via co-assembly with myosin 2 and through an actin binding site in its N-terminal extension. miRNA-mediated knockdown of myosin 18A⍺ results in a significant defect in spine maturation that is rescued by an RNAi-immune version of myosin 18A⍺. Importantly, β-Pix co-localizes with myosin 18A⍺ in spines, and its spine localization is lost upon myosin 18A⍺ knockdown or when its myosin 18A⍺ binding site is deleted. Finally, we show that the spines of myosin 18A⍺ knockdown Purkinje neurons contain significantly less F-actin and myosin 2. Together, these data argue that mixed filaments of myosin 2 and myosin 18A⍺ form a complex with β-Pix in Purkinje neuron spines that promotes spine maturation by enhancing the assembly of actin and myosin filaments downstream of β-Pix's GEF activity.
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Affiliation(s)
- Christopher J Alexander
- Molecular Cell Biology Laboratory, Cell and Developmental Biology Center, NHLBI, NIH, Bethesda, MD, USA
| | - Melanie Barzik
- Laboratory of Molecular Genetics, NIDCD, NIH, Bethesda, MD, USA
| | - Ikuko Fujiwara
- Graduate School of Science, Osaka City University, Osaka, Japan
| | | | - Ya-Xian Wang
- Advanced Imaging Core, NIDCD, NIH, Betheda, MD, USA
| | | | | | - John A Hammer
- Molecular Cell Biology Laboratory, Cell and Developmental Biology Center, NHLBI, NIH, Bethesda, MD, USA
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14
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Dorsal Hippocampal Actin Polymerization Is Necessary for Activation of G-Protein-Coupled Estrogen Receptor (GPER) to Increase CA1 Dendritic Spine Density and Enhance Memory Consolidation. J Neurosci 2019; 39:9598-9610. [PMID: 31628182 DOI: 10.1523/jneurosci.2687-18.2019] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 09/03/2019] [Accepted: 10/13/2019] [Indexed: 11/21/2022] Open
Abstract
Activation of the membrane estrogen receptor G-protein-coupled estrogen receptor (GPER) in ovariectomized mice via the GPER agonist G-1 mimics the beneficial effects of 17β-estradiol (E2) on hippocampal CA1 spine density and memory consolidation, yet the cell-signaling mechanisms mediating these effects remain unclear. The present study examined the role of actin polymerization and c-Jun N-terminal kinase (JNK) phosphorylation in mediating effects of dorsal hippocampally infused G-1 on CA1 dendritic spine density and consolidation of object recognition and spatial memories in ovariectomized mice. We first showed that object learning increased apical CA1 spine density in the dorsal hippocampus (DH) within 40 min. We then found that DH infusion of G-1 increased both CA1 spine density and phosphorylation of the actin polymerization regulator cofilin, suggesting that activation of GPER may increase spine morphogenesis through actin polymerization. As with memory consolidation in our previous work (Kim et al., 2016), effects of G-1 on CA1 spine density and cofilin phosphorylation depended on JNK phosphorylation in the DH. Also consistent with our previous findings, E2-induced cofilin phosphorylation was not dependent on GPER activation. Finally, we found that infusion of the actin polymerization inhibitor, latrunculin A, into the DH prevented G-1 from increasing apical CA1 spine density and enhancing both object recognition and spatial memory consolidation. Collectively, these data demonstrate that GPER-mediated hippocampal spinogenesis and memory consolidation depend on JNK and cofilin signaling, supporting a critical role for actin polymerization in the GPER-induced regulation of hippocampal function in female mice.SIGNIFICANCE STATEMENT Emerging evidence suggests that G-protein-coupled estrogen receptor (GPER) activation mimics effects of 17β-estradiol on hippocampal memory consolidation. Unlike canonical estrogen receptors, GPER activation is associated with reduced cancer cell proliferation; thus, understanding the molecular mechanisms through which GPER regulates hippocampal function may provide new avenues for the development of drugs that provide the cognitive benefits of estrogens without harmful side effects. Here, we demonstrate that GPER increases CA1 dendritic spine density and hippocampal memory consolidation in a manner dependent on actin polymerization and c-Jun N-terminal kinase phosphorylation. These findings provide novel insights into the role of GPER in mediating hippocampal morphology and memory consolidation, and may suggest first steps toward new therapeutics that more safely and effectively reduce memory decline in menopausal women.
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15
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Bagni C, Zukin RS. A Synaptic Perspective of Fragile X Syndrome and Autism Spectrum Disorders. Neuron 2019; 101:1070-1088. [PMID: 30897358 PMCID: PMC9628679 DOI: 10.1016/j.neuron.2019.02.041] [Citation(s) in RCA: 194] [Impact Index Per Article: 38.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 02/25/2019] [Accepted: 02/27/2019] [Indexed: 12/28/2022]
Abstract
Altered synaptic structure and function is a major hallmark of fragile X syndrome (FXS), autism spectrum disorders (ASDs), and other intellectual disabilities (IDs), which are therefore classified as synaptopathies. FXS and ASDs, while clinically and genetically distinct, share significant comorbidity, suggesting that there may be a common molecular and/or cellular basis, presumably at the synapse. In this article, we review brain architecture and synaptic pathways that are dysregulated in FXS and ASDs, including spine architecture, signaling in synaptic plasticity, local protein synthesis, (m)RNA modifications, and degradation. mRNA repression is a powerful mechanism for the regulation of synaptic structure and efficacy. We infer that there is no single pathway that explains most of the etiology and discuss new findings and the implications for future work directed at improving our understanding of the pathogenesis of FXS and related ASDs and the design of therapeutic strategies to ameliorate these disorders.
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Affiliation(s)
- Claudia Bagni
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland; Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy.
| | - R Suzanne Zukin
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York City, NY, USA.
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16
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Parato J, Shen H, Smith SS. α4βδ GABA A Receptors Trigger Synaptic Pruning and Reduce Dendritic Length of Female Mouse CA3 Hippocampal Pyramidal Cells at Puberty. Neuroscience 2018; 398:23-36. [PMID: 30496825 DOI: 10.1016/j.neuroscience.2018.11.032] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 11/01/2018] [Accepted: 11/20/2018] [Indexed: 01/24/2023]
Abstract
Synaptic pruning during adolescence is critical for optimal cognition. The CA3 hippocampus contains unique spine types and plays a pivotal role in pattern separation and seizure generation, where sex differences exist, but adolescent pruning has only been studied in the male. Thus, for the present study we assessed pruning of specific spine types in the CA3 hippocampus during adolescence and investigated a possible mechanism in the female mouse. To this end, we used Golgi-impregnated brains from pubertal (∼PND 35, assessed by vaginal opening) and post-pubertal (PND 56) mice. Spine density was assessed from z-stack (0.1-μm steps) images taken using a Nikon DS-U3 camera through a Nikon Eclipse Ci-L microscope and analyzed with NIS Elements. Spine density decreased significantly (P < 0.05) during adolescence, with 50-60% decreases in mushroom and stubby spine-types (P < 0.05, ∼PND35 vs. PND56) in non-proestrous mice. This was associated with decreases in kalirin-7, a spine protein which stabilizes the cytoskeleton and is required for spine maintenance. Because our previous findings suggest that pubertal increases in α4βδ GABAA receptors (GABARs) trigger pruning in CA1, we investigated their role in CA3. α4 expression in CA3 hippocampus increased 4-fold at puberty (P < 0.05), assessed by immunostaining and verified electrophysiologically by an increased response to gaboxadol (100 nM), which is selective for α4βδ. Knock-out of α4 prevented the pubertal decrease in kalirin-7 and synaptic pruning and also increased the dendritic length, demonstrating a functional link. These data suggest that pubertal α4βδ GABARs alter dendritic morphology and trigger pruning in female CA3 hippocampus.
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Affiliation(s)
- Julie Parato
- Department of Physiology and Pharmacology, SUNY Downstate Medical Center, 450 Clarkson Ave, Brooklyn, NY 11203, USA; Program in Neural and Behavioral Science, SUNY Downstate Medical Center, 450 Clarkson Ave, Brooklyn, NY 11203, USA
| | - Hui Shen
- Department of Physiology and Pharmacology, SUNY Downstate Medical Center, 450 Clarkson Ave, Brooklyn, NY 11203, USA; School of Biomedical Engineering, Tianjin Medical University, No. 22 Qixiangtai Road, Heping District, Tianjin 300070, China
| | - Sheryl S Smith
- Department of Physiology and Pharmacology, SUNY Downstate Medical Center, 450 Clarkson Ave, Brooklyn, NY 11203, USA; The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA.
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17
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Cahill ME, Browne CJ, Wang J, Hamilton PJ, Dong Y, Nestler EJ. Withdrawal from repeated morphine administration augments expression of the RhoA network in the nucleus accumbens to control synaptic structure. J Neurochem 2018; 147:84-98. [PMID: 30071134 DOI: 10.1111/jnc.14563] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 07/26/2018] [Accepted: 07/27/2018] [Indexed: 12/18/2022]
Abstract
The nucleus accumbens (NAc) is a critical brain reward region that mediates the rewarding effects of drugs of abuse, including those of morphine and other opiates. Drugs of abuse induce widespread alterations in gene transcription and dendritic spine morphology in medium spiny neurons (MSNs) of the NAc that ultimately influence NAc excitability and hence reward-related behavioral responses. Growing evidence indicates that within the NAc small GTPases are common intracellular targets of drugs of abuse where these molecules regulate drug-mediated transcriptional and spine morphogenic effects. The RhoA small GTPase is among the most well-characterized members of the Ras superfamily of small GTPases, and recent work highlights an important role for hippocampal RhoA in morphine-facilitated reward behavior. Despite this, it remains unclear how RhoA pathway signaling in the NAc is affected by withdrawal from morphine. To investigate this question, using subcellular fractionation and subsequent protein profiling we examined the expression of key components of the RhoA pathway in NAc nuclear, cytoplasmic, and synaptosomal compartments during multiple withdrawal periods from repeated morphine administration. Furthermore, using in vivo viral-mediated gene transfer, we determined the consequences of revealed RhoA pathway alterations on NAc MSN dendritic spine morphology. Our findings reveal an important role for RhoA signaling cascades in mediating the effects of long-term morphine withdrawal on NAc MSN dendritic spine elimination. OPEN PRACTICES Open Science: This manuscript was awarded with the Open Materials Badge. For more information see: https://cos.io/our-services/open-science-badges/.
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Affiliation(s)
- Michael E Cahill
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Caleb J Browne
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Junshi Wang
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Peter J Hamilton
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Yan Dong
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Eric J Nestler
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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18
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Simmons DA. Modulating Neurotrophin Receptor Signaling as a Therapeutic Strategy for Huntington's Disease. J Huntingtons Dis 2018; 6:303-325. [PMID: 29254102 PMCID: PMC5757655 DOI: 10.3233/jhd-170275] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Huntington’s disease (HD) is an autosomal dominant neurodegenerative disorder caused by CAG repeat expansions in the IT15 gene which encodes the huntingtin (HTT) protein. Currently, no treatments capable of preventing or slowing disease progression exist. Disease modifying therapeutics for HD would be expected to target a comprehensive set of degenerative processes given the diverse mechanisms contributing to HD pathogenesis including neuroinflammation, excitotoxicity, and transcription dysregulation. A major contributor to HD-related degeneration is mutant HTT-induced loss of neurotrophic support. Thus, neurotrophin (NT) receptors have emerged as therapeutic targets in HD. The considerable overlap between NT signaling networks and those dysregulated by mutant HTT provides strong theoretical support for this approach. This review will focus on the contributions of disrupted NT signaling in HD-related neurodegeneration and how targeting NT receptors to augment pro-survival signaling and/or to inhibit degenerative signaling may combat HD pathologies. Therapeutic strategies involving NT delivery, peptidomimetics, and the targeting of specific NT receptors (e.g., Trks or p75NTR), particularly with small molecule ligands, are discussed.
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Affiliation(s)
- Danielle A Simmons
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
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19
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Cahill ME, Walker DM, Gancarz AM, Wang ZJ, Lardner CK, Bagot RC, Neve RL, Dietz DM, Nestler EJ. The dendritic spine morphogenic effects of repeated cocaine use occur through the regulation of serum response factor signaling. Mol Psychiatry 2018; 23:1474-1486. [PMID: 28555077 PMCID: PMC5709273 DOI: 10.1038/mp.2017.116] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 03/23/2017] [Accepted: 04/12/2017] [Indexed: 12/28/2022]
Abstract
The nucleus accumbens (NAc) is a primary brain reward region composed predominantly of medium spiny neurons (MSNs). In response to early withdrawal from repeated cocaine administration, de novo dendritic spine formation occurs in NAc MSNs. Much evidence indicates that this new spine formation facilitates the rewarding properties of cocaine. Early withdrawal from repeated cocaine also produces dramatic alterations in the transcriptome of NAc MSNs, but how such alterations influence cocaine's effects on dendritic spine formation remain unclear. Studies in non-neuronal cells indicate that actin cytoskeletal regulatory pathways in nuclei have a direct role in the regulation of gene transcription in part by controlling the access of co-activators to their transcription factor partners. In particular, actin state dictates the interaction between the serum response factor (SRF) transcription factor and one of its principal co-activators, MAL. Here we show that cocaine induces alterations in nuclear F-actin signaling pathways in the NAc with associated changes in the nuclear subcellular localization of SRF and MAL. Using in vivo optogenetics, the brain region-specific inputs to the NAc that mediate these nuclear changes are investigated. Finally, we demonstrate that regulated SRF expression, in turn, is critical for the effects of cocaine on dendritic spine formation and for cocaine-mediated behavioral sensitization. Collectively, these findings reveal a mechanism by which nuclear-based changes influence the structure of NAc MSNs in response to cocaine.
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Affiliation(s)
- ME Cahill
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - DM Walker
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - AM Gancarz
- Department of Pharmacology and Toxicology, Research Institute on Addictions, Program in Neuroscience, State University at Buffalo, Buffalo, NY, USA
| | - ZJ Wang
- Department of Pharmacology and Toxicology, Research Institute on Addictions, Program in Neuroscience, State University at Buffalo, Buffalo, NY, USA
| | - CK Lardner
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - RC Bagot
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA,Department of Psychology, McGill University, Montréal, QC, Canada
| | - RL Neve
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - DM Dietz
- Department of Pharmacology and Toxicology, Research Institute on Addictions, Program in Neuroscience, State University at Buffalo, Buffalo, NY, USA
| | - EJ Nestler
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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20
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Blackwell KT, Salinas AG, Tewatia P, English B, Hellgren Kotaleski J, Lovinger DM. Molecular mechanisms underlying striatal synaptic plasticity: relevance to chronic alcohol consumption and seeking. Eur J Neurosci 2018; 49:768-783. [PMID: 29602186 DOI: 10.1111/ejn.13919] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 03/19/2018] [Accepted: 03/20/2018] [Indexed: 01/02/2023]
Abstract
The striatum, the input structure of the basal ganglia, is a major site of learning and memory for goal-directed actions and habit formation. Spiny projection neurons of the striatum integrate cortical, thalamic, and nigral inputs to learn associations, with cortico-striatal synaptic plasticity as a learning mechanism. Signaling molecules implicated in synaptic plasticity are altered in alcohol withdrawal, which may contribute to overly strong learning and increased alcohol seeking and consumption. To understand how interactions among signaling molecules produce synaptic plasticity, we implemented a mechanistic model of signaling pathways activated by dopamine D1 receptors, acetylcholine receptors, and glutamate. We use our novel, computationally efficient simulator, NeuroRD, to simulate stochastic interactions both within and between dendritic spines. Dopamine release during theta burst and 20-Hz stimulation was extrapolated from fast-scan cyclic voltammetry data collected in mouse striatal slices. Our results show that the combined activity of several key plasticity molecules correctly predicts the occurrence of either LTP, LTD, or no plasticity for numerous experimental protocols. To investigate spatial interactions, we stimulate two spines, either adjacent or separated on a 20-μm dendritic segment. Our results show that molecules underlying LTP exhibit spatial specificity, whereas 2-arachidonoylglycerol exhibits a spatially diffuse elevation. We also implement changes in NMDA receptors, adenylyl cyclase, and G protein signaling that have been measured following chronic alcohol treatment. Simulations under these conditions suggest that the molecular changes can predict changes in synaptic plasticity, thereby accounting for some aspects of alcohol use disorder.
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Affiliation(s)
- Kim T Blackwell
- The Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, USA.,Department of Bioengineering, George Mason University, Fairfax, VA, USA
| | - Armando G Salinas
- The Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, USA.,National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, USA
| | - Parul Tewatia
- Science for Life Laboratory, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Brad English
- The Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, USA
| | - Jeanette Hellgren Kotaleski
- Science for Life Laboratory, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, Stockholm, Sweden
| | - David M Lovinger
- National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, USA
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21
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Pyronneau A, He Q, Hwang JY, Porch M, Contractor A, Zukin RS. Aberrant Rac1-cofilin signaling mediates defects in dendritic spines, synaptic function, and sensory perception in fragile X syndrome. Sci Signal 2017; 10:10/504/eaan0852. [PMID: 29114038 DOI: 10.1126/scisignal.aan0852] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Fragile X syndrome (FXS) is the most common inherited cause of intellectual disabilities and a leading cause of autism. FXS is caused by a trinucleotide expansion in the gene FMR1 on the X chromosome. The neuroanatomical hallmark of FXS is an overabundance of immature dendritic spines, a factor thought to underlie synaptic dysfunction and impaired cognition. We showed that aberrantly increased activity of the Rho GTPase Rac1 inhibited the actin-depolymerizing factor cofilin, a major determinant of dendritic spine structure, and caused disease-associated spine abnormalities in the somatosensory cortex of FXS model mice. Increased cofilin phosphorylation and actin polymerization coincided with abnormal dendritic spines and impaired synaptic maturation. Viral delivery of a constitutively active cofilin mutant (cofilinS3A) into the somatosensory cortex of Fmr1-deficient mice rescued the immature dendritic spine phenotype and increased spine density. Inhibition of the Rac1 effector PAK1 with a small-molecule inhibitor rescued cofilin signaling in FXS mice, indicating a causal relationship between PAK1 and cofilin signaling. PAK1 inhibition rescued synaptic signaling (specifically the synaptic ratio of NMDA/AMPA in layer V pyramidal neurons) and improved sensory processing in FXS mice. These findings suggest a causal relationship between increased Rac1-cofilin signaling, synaptic defects, and impaired sensory processing in FXS and uncover a previously unappreciated role for impaired Rac1-cofilin signaling in the aberrant spine morphology and spine density associated with FXS.
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Affiliation(s)
- Alexander Pyronneau
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Qionger He
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Jee-Yeon Hwang
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Morgan Porch
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Anis Contractor
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.,Department of Neurobiology, Weinberg College of Arts and Sciences, Northwestern University, Evanston, IL 60208, USA
| | - R Suzanne Zukin
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, NY 10461, USA.
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22
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Smith KR, Rajgor D, Hanley JG. Differential regulation of the Rac1 GTPase-activating protein (GAP) BCR during oxygen/glucose deprivation in hippocampal and cortical neurons. J Biol Chem 2017; 292:20173-20183. [PMID: 29046349 PMCID: PMC5724004 DOI: 10.1074/jbc.m117.796292] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 09/28/2017] [Indexed: 12/22/2022] Open
Abstract
Brain ischemia causes oxygen and glucose deprivation (OGD) in neurons, triggering a cascade of events leading to synaptic accumulation of glutamate. Excessive activation of glutamate receptors causes excitotoxicity and delayed cell death in vulnerable neurons. Following global cerebral ischemia, hippocampal CA1 pyramidal neurons are more vulnerable to injury than their cortical counterparts, but the mechanisms that underlie this difference are unclear. Signaling via Rho-family small GTPases, their upstream guanine nucleotide exchange factors, and GTPase-activating proteins (GAPs) is differentially dysregulated in response to OGD/ischemia in hippocampal and cortical neurons. Increased Rac1 activity caused by OGD/ischemia contributes to neuronal death in hippocampal neurons via diverse effects on NADPH oxidase activity and dendritic spine morphology. The Rac1 guanine nucleotide exchange factor Tiam1 mediates an OGD-induced increase in Rac1 activity in hippocampal neurons; however, the identity of an antagonistic GAP remains elusive. Here we show that the Rac1 GAP breakpoint cluster region (BCR) associates with NMDA receptors (NMDARs) along with Tiam1 and that this protein complex is more abundant in hippocampal compared with cortical neurons. Although total BCR is similar in the two neuronal types, BCR is more active in hippocampal compared with cortical neurons. OGD causes an NMDAR- and Ca2+-permeable AMPAR-dependent deactivation of BCR in hippocampal but not cortical neurons. BCR knockdown occludes OGD-induced Rac1 activation in hippocampal neurons. Furthermore, disrupting the Tiam1–NMDAR interaction with a fragment of Tiam1 blocks OGD-induced Tiam1 activation but has no effect on the deactivation of BCR. This work identifies BCR as a critical player in Rac1 regulation during OGD in hippocampal neurons.
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Affiliation(s)
- Katharine R Smith
- Centre for Synaptic Plasticity and School of Biochemistry, Biomedical Sciences Building, University of Bristol, University Walk, Bristol BS8 1TD, United Kingdom; Department of Pharmacology, University of Colorado Denver School of Medicine, Aurora, Colorado 80045.
| | - Dipen Rajgor
- Centre for Synaptic Plasticity and School of Biochemistry, Biomedical Sciences Building, University of Bristol, University Walk, Bristol BS8 1TD, United Kingdom
| | - Jonathan G Hanley
- Centre for Synaptic Plasticity and School of Biochemistry, Biomedical Sciences Building, University of Bristol, University Walk, Bristol BS8 1TD, United Kingdom
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23
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Jȩdrzejewska-Szmek J, Luczak V, Abel T, Blackwell KT. β-adrenergic signaling broadly contributes to LTP induction. PLoS Comput Biol 2017; 13:e1005657. [PMID: 28742159 PMCID: PMC5546712 DOI: 10.1371/journal.pcbi.1005657] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 08/07/2017] [Accepted: 06/27/2017] [Indexed: 12/18/2022] Open
Abstract
Long-lasting forms of long-term potentiation (LTP) represent one of the major cellular mechanisms underlying learning and memory. One of the fundamental questions in the field of LTP is why different molecules are critical for long-lasting forms of LTP induced by diverse experimental protocols. Further complexity stems from spatial aspects of signaling networks, such that some molecules function in the dendrite and some are critical in the spine. We investigated whether the diverse experimental evidence can be unified by creating a spatial, mechanistic model of multiple signaling pathways in hippocampal CA1 neurons. Our results show that the combination of activity of several key kinases can predict the occurrence of long-lasting forms of LTP for multiple experimental protocols. Specifically Ca2+/calmodulin activated kinase II, protein kinase A and exchange protein activated by cAMP (Epac) together predict the occurrence of LTP in response to strong stimulation (multiple trains of 100 Hz) or weak stimulation augmented by isoproterenol. Furthermore, our analysis suggests that activation of the β-adrenergic receptor either via canonical (Gs-coupled) or non-canonical (Gi-coupled) pathways underpins most forms of long-lasting LTP. Simulations make the experimentally testable prediction that a complete antagonist of the β-adrenergic receptor will likely block long-lasting LTP in response to strong stimulation. Collectively these results suggest that converging molecular mechanisms allow CA1 neurons to flexibly utilize signaling mechanisms best tuned to temporal pattern of synaptic input to achieve long-lasting LTP and memory storage. Long-term potentiation of the strength of synaptic connections is a mechanism of learning and memory storage. One of the most confusing aspects of hippocampal synaptic potentiation is that numerous experiments have revealed the requirement for a plethora of signaling molecules. Furthermore the degree to which molecules activated by the stress response modify hippocampal synaptic potentiation and memory is still unclear. We used a computational model to demonstrate that this molecular diversity can be explained by considering a combination of several key molecules. We also show that activation of β-adrenergic receptors by the stress response appears to be involved in most forms of synaptic potentiation, though in some cases unconventional mechanisms are utilized. This suggests that novel treatments for stress-related disorders may have more success if they target unconventional mechanisms activated by β-adrenergic receptors.
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Affiliation(s)
- Joanna Jȩdrzejewska-Szmek
- The Krasnow Institute for Advanced Studies, George Mason University, Fairfax, Virginia, United States of America
| | - Vincent Luczak
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Ted Abel
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Kim T Blackwell
- The Krasnow Institute for Advanced Studies, George Mason University, Fairfax, Virginia, United States of America
- * E-mail:
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24
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Hamilton AM, Lambert JT, Parajuli LK, Vivas O, Park DK, Stein IS, Jahncke JN, Greenberg ME, Margolis SS, Zito K. A dual role for the RhoGEF Ephexin5 in regulation of dendritic spine outgrowth. Mol Cell Neurosci 2017; 80:66-74. [PMID: 28185854 DOI: 10.1016/j.mcn.2017.02.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 02/01/2017] [Accepted: 02/04/2017] [Indexed: 12/28/2022] Open
Abstract
The outgrowth of new dendritic spines is closely linked to the formation of new synapses, and is thought to be a vital component of the experience-dependent circuit plasticity that supports learning. Here, we examined the role of the RhoGEF Ephexin5 in driving activity-dependent spine outgrowth. We found that reducing Ephexin5 levels increased spine outgrowth, and increasing Ephexin5 levels decreased spine outgrowth in a GEF-dependent manner, suggesting that Ephexin5 acts as an inhibitor of spine outgrowth. Notably, we found that increased neural activity led to a proteasome-dependent reduction in the levels of Ephexin5 in neuronal dendrites, which could facilitate the enhanced spine outgrowth observed following increased neural activity. Surprisingly, we also found that Ephexin5-GFP levels were elevated on the dendrite at sites of future new spines, prior to new spine outgrowth. Moreover, lowering neuronal Ephexin5 levels inhibited new spine outgrowth in response to both global increases in neural activity and local glutamatergic stimulation of the dendrite, suggesting that Ephexin5 is necessary for activity-dependent spine outgrowth. Our data support a model in which Ephexin5 serves a dual role in spinogenesis, acting both as a brake on overall spine outgrowth and as a necessary component in the site-specific formation of new spines.
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Affiliation(s)
- A M Hamilton
- Center for Neuroscience, University of California Davis, Davis, CA 95618, USA
| | - J T Lambert
- Center for Neuroscience, University of California Davis, Davis, CA 95618, USA
| | - L K Parajuli
- Center for Neuroscience, University of California Davis, Davis, CA 95618, USA
| | - O Vivas
- Center for Neuroscience, University of California Davis, Davis, CA 95618, USA
| | - D K Park
- Center for Neuroscience, University of California Davis, Davis, CA 95618, USA
| | - I S Stein
- Center for Neuroscience, University of California Davis, Davis, CA 95618, USA
| | - J N Jahncke
- Center for Neuroscience, University of California Davis, Davis, CA 95618, USA
| | - M E Greenberg
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - S S Margolis
- Department of Biological Chemistry, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - K Zito
- Center for Neuroscience, University of California Davis, Davis, CA 95618, USA.
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25
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Lin YC, Frei JA, Kilander MBC, Shen W, Blatt GJ. A Subset of Autism-Associated Genes Regulate the Structural Stability of Neurons. Front Cell Neurosci 2016; 10:263. [PMID: 27909399 PMCID: PMC5112273 DOI: 10.3389/fncel.2016.00263] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 10/28/2016] [Indexed: 12/15/2022] Open
Abstract
Autism spectrum disorder (ASD) comprises a range of neurological conditions that affect individuals’ ability to communicate and interact with others. People with ASD often exhibit marked qualitative difficulties in social interaction, communication, and behavior. Alterations in neurite arborization and dendritic spine morphology, including size, shape, and number, are hallmarks of almost all neurological conditions, including ASD. As experimental evidence emerges in recent years, it becomes clear that although there is broad heterogeneity of identified autism risk genes, many of them converge into similar cellular pathways, including those regulating neurite outgrowth, synapse formation and spine stability, and synaptic plasticity. These mechanisms together regulate the structural stability of neurons and are vulnerable targets in ASD. In this review, we discuss the current understanding of those autism risk genes that affect the structural connectivity of neurons. We sub-categorize them into (1) cytoskeletal regulators, e.g., motors and small RhoGTPase regulators; (2) adhesion molecules, e.g., cadherins, NCAM, and neurexin superfamily; (3) cell surface receptors, e.g., glutamatergic receptors and receptor tyrosine kinases; (4) signaling molecules, e.g., protein kinases and phosphatases; and (5) synaptic proteins, e.g., vesicle and scaffolding proteins. Although the roles of some of these genes in maintaining neuronal structural stability are well studied, how mutations contribute to the autism phenotype is still largely unknown. Investigating whether and how the neuronal structure and function are affected when these genes are mutated will provide insights toward developing effective interventions aimed at improving the lives of people with autism and their families.
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Affiliation(s)
- Yu-Chih Lin
- Laboratory of Neuronal Connectivity, Program in Neuroscience, Hussman Institute for Autism, Baltimore MD, USA
| | - Jeannine A Frei
- Laboratory of Neuronal Connectivity, Program in Neuroscience, Hussman Institute for Autism, Baltimore MD, USA
| | - Michaela B C Kilander
- Laboratory of Neuronal Connectivity, Program in Neuroscience, Hussman Institute for Autism, Baltimore MD, USA
| | - Wenjuan Shen
- Laboratory of Neuronal Connectivity, Program in Neuroscience, Hussman Institute for Autism, Baltimore MD, USA
| | - Gene J Blatt
- Laboratory of Autism Neurocircuitry, Program in Neuroscience, Hussman Institute for Autism, Baltimore MD, USA
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26
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Simmons DA, Belichenko NP, Ford EC, Semaan S, Monbureau M, Aiyaswamy S, Holman CM, Condon C, Shamloo M, Massa SM, Longo FM. A small molecule p75NTR ligand normalizes signalling and reduces Huntington's disease phenotypes in R6/2 and BACHD mice. Hum Mol Genet 2016; 25:4920-4938. [PMID: 28171570 PMCID: PMC5418739 DOI: 10.1093/hmg/ddw316] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 08/18/2016] [Accepted: 09/12/2016] [Indexed: 01/03/2023] Open
Abstract
Decreases in the ratio of neurotrophic versus neurodegenerative signalling play a critical role in Huntington’s disease (HD) pathogenesis and recent evidence suggests that the p75 neurotrophin receptor (NTR) contributes significantly to disease progression. p75NTR signalling intermediates substantially overlap with those promoting neuronal survival and synapse integrity and with those affected by the mutant huntingtin (muHtt) protein. MuHtt increases p75NTR-associated deleterious signalling and decreases survival signalling suggesting that p75NTR could be a valuable therapeutic target. This hypothesis was investigated by examining the effects of an orally bioavailable, small molecule p75NTR ligand, LM11A-31, on HD-related neuropathology in HD mouse models (R6/2, BACHD). LM11A-31 restored striatal AKT and other pro-survival signalling while inhibiting c-Jun kinase (JNK) and other degenerative signalling. Normalizing p75NTR signalling with LM11A-31 was accompanied by reduced Htt aggregates and striatal cholinergic interneuron degeneration as well as extended survival in R6/2 mice. The p75NTR ligand also decreased inflammation, increased striatal and hippocampal dendritic spine density, and improved motor performance and cognition in R6/2 and BACHD mice. These results support small molecule modulation of p75NTR as an effective HD therapeutic strategy. LM11A-31 has successfully completed Phase I safety and pharmacokinetic clinical trials and is therefore a viable candidate for clinical studies in HD.
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Affiliation(s)
- Danielle A. Simmons
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine
| | - Nadia P. Belichenko
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine
| | - Ellen C. Ford
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine
| | - Sarah Semaan
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine
| | - Marie Monbureau
- Behavioral and Functional Neuroscience Laboratory, Institute for Neuro-Innovation and Translational Neurosciences
| | - Sruti Aiyaswamy
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine
| | - Cameron M. Holman
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine
| | - Christina Condon
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine
| | - Mehrdad Shamloo
- Behavioral and Functional Neuroscience Laboratory, Institute for Neuro-Innovation and Translational Neurosciences
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Stephen M. Massa
- Department of Neurology and Laboratory for Computational Neurochemistry and Drug Discovery, Department of Veterans Affairs Medical Center and Department of Neurology, University of California–San Francisco, San Francisco, CA, USA
| | - Frank M. Longo
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine
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27
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Zimering JH, Dong Y, Fang F, Huang L, Zhang Y, Xie Z. Anesthetic Sevoflurane Causes Rho-Dependent Filopodial Shortening in Mouse Neurons. PLoS One 2016; 11:e0159637. [PMID: 27441369 PMCID: PMC4956198 DOI: 10.1371/journal.pone.0159637] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 07/06/2016] [Indexed: 11/25/2022] Open
Abstract
Early postnatal anesthesia causes long-lasting learning and memory impairment in rodents, however, evidence for a specific neurotoxic effect on early synaptogenesis has not been demonstrated. Drebrin A is an actin binding protein whose localization in dendritic protrusions serves an important role in dendritic spine morphogenesis, and is a marker for early synaptogenesis. We therefore set out to investigate whether clinically-relevant concentrations of anesthetic sevoflurane, widely- used in infants and children, alters dendritic morphology in cultured fetal day 16 mouse hippocampal neurons. After 7 days in vitro, mouse hippocampal neurons were exposed to four hours of 3% sevoflurane in 95% air/5% CO2 or control condition (95% air/5% CO2). Neurons were fixed in 4% paraformaldehyde and stained with Alexa Fluor555-Phalloidin, and/or rabbit anti-mouse drebrin A/E antibodies which permitted subcellular localization of filamentous (F)-actin and/or drebrin immunoreactivity, respectively. Sevoflurane caused acute significant length-shortening in filopodia and thin dendritic spines in days-in-vitro 7 neurons, an effect which was completely rescued by co-incubating neurons with ten micromolar concentrations of the selective Rho kinase inhibitor Y27632. Filopodia and thin spine recovered in length two days after sevoflurane exposure. Yet cluster-type filopodia (a precursor to synaptic filopodia) were persistently significantly decreased in number on day-in-vitro 9, in part owing to preferential localization of drebrin immunoreactivity to dendritic shafts versus filopodial stalks. These data suggest that sevoflurane induces F-actin depolymerization leading to acute, reversible length-shortening in dendritic protrusions through a mechanism involving (in part) activation of RhoA/Rho kinase signaling and impairs localization of drebrin A to filopodia required for early excitatory synapse formation.
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Affiliation(s)
- Jeffrey H. Zimering
- University of Rochester School of Medicine and Dentistry, Rochester, New York, United States of America
- Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Yuanlin Dong
- Geriatric Anesthesia Research Unit, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Fang Fang
- Geriatric Anesthesia Research Unit, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Lining Huang
- Geriatric Anesthesia Research Unit, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Yiying Zhang
- Geriatric Anesthesia Research Unit, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Zhongcong Xie
- Geriatric Anesthesia Research Unit, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, United States of America
- * E-mail:
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28
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Cahill ME, Bagot RC, Gancarz AM, Walker DM, Sun H, Wang ZJ, Heller EA, Feng J, Kennedy PJ, Koo JW, Cates HM, Neve RL, Shen L, Dietz DM, Nestler EJ. Bidirectional Synaptic Structural Plasticity after Chronic Cocaine Administration Occurs through Rap1 Small GTPase Signaling. Neuron 2016; 89:566-82. [PMID: 26844834 DOI: 10.1016/j.neuron.2016.01.031] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 01/11/2016] [Accepted: 01/19/2016] [Indexed: 12/25/2022]
Abstract
Dendritic spines are the sites of most excitatory synapses in the CNS, and opposing alterations in the synaptic structure of medium spiny neurons (MSNs) of the nucleus accumbens (NAc), a primary brain reward region, are seen at early versus late time points after cocaine administration. Here we investigate the time-dependent molecular and biochemical processes that regulate this bidirectional synaptic structural plasticity of NAc MSNs and associated changes in cocaine reward in response to chronic cocaine exposure. Our findings reveal key roles for the bidirectional synaptic expression of the Rap1b small GTPase and an associated local synaptic protein translation network in this process. The transcriptional mechanisms and pathway-specific inputs to NAc that regulate Rap1b expression are also characterized. Collectively, these findings provide a precise mechanism by which nuclear to synaptic interactions induce "metaplasticity" in NAc MSNs, and we reveal the specific effects of this plasticity on reward behavior in a brain circuit-specific manner.
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Affiliation(s)
- Michael E Cahill
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Rosemary C Bagot
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Amy M Gancarz
- Department of Pharmacology and Toxicology, Research Institute on Addictions, Program in Neuroscience, State University of New York at Buffalo, Buffalo, NY 14214, USA
| | - Deena M Walker
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - HaoSheng Sun
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Zi-Jun Wang
- Department of Pharmacology and Toxicology, Research Institute on Addictions, Program in Neuroscience, State University of New York at Buffalo, Buffalo, NY 14214, USA
| | - Elizabeth A Heller
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Jian Feng
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Pamela J Kennedy
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Ja Wook Koo
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Hannah M Cates
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Rachael L Neve
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Li Shen
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - David M Dietz
- Department of Pharmacology and Toxicology, Research Institute on Addictions, Program in Neuroscience, State University of New York at Buffalo, Buffalo, NY 14214, USA
| | - Eric J Nestler
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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29
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Regulation of the Postsynaptic Compartment of Excitatory Synapses by the Actin Cytoskeleton in Health and Its Disruption in Disease. Neural Plast 2016; 2016:2371970. [PMID: 27127658 PMCID: PMC4835652 DOI: 10.1155/2016/2371970] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 03/09/2016] [Indexed: 02/07/2023] Open
Abstract
Disruption of synaptic function at excitatory synapses is one of the earliest pathological changes seen in wide range of neurological diseases. The proper control of the segregation of neurotransmitter receptors at these synapses is directly correlated with the intact regulation of the postsynaptic cytoskeleton. In this review, we are discussing key factors that regulate the structure and dynamics of the actin cytoskeleton, the major cytoskeletal building block that supports the postsynaptic compartment. Special attention is given to the complex interplay of actin-associated proteins that are found in the synaptic specialization. We then discuss our current understanding of how disruption of these cytoskeletal elements may contribute to the pathological events observed in the nervous system under disease conditions with a particular focus on Alzheimer's disease pathology.
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30
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Control of Dendritic Spine Morphological and Functional Plasticity by Small GTPases. Neural Plast 2016; 2016:3025948. [PMID: 26989514 PMCID: PMC4775798 DOI: 10.1155/2016/3025948] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 01/06/2016] [Accepted: 01/19/2016] [Indexed: 11/18/2022] Open
Abstract
Structural plasticity of excitatory synapses is a vital component of neuronal development, synaptic plasticity, and behaviour. Abnormal development or regulation of excitatory synapses has also been strongly implicated in many neurodevelopmental, psychiatric, and neurodegenerative disorders. In the mammalian forebrain, the majority of excitatory synapses are located on dendritic spines, specialized dendritic protrusions that are enriched in actin. Research over recent years has begun to unravel the complexities involved in the regulation of dendritic spine structure. The small GTPase family of proteins have emerged as key regulators of structural plasticity, linking extracellular signals with the modulation of dendritic spines, which potentially underlies their ability to influence cognition. Here we review a number of studies that examine how small GTPases are activated and regulated in neurons and furthermore how they can impact actin dynamics, and thus dendritic spine morphology. Elucidating this signalling process is critical for furthering our understanding of the basic mechanisms by which information is encoded in neural circuits but may also provide insight into novel targets for the development of effective therapies to treat cognitive dysfunction seen in a range of neurological disorders.
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31
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Bencsik N, Szíber Z, Liliom H, Tárnok K, Borbély S, Gulyás M, Rátkai A, Szűcs A, Hazai-Novák D, Ellwanger K, Rácz B, Pfizenmaier K, Hausser A, Schlett K. Protein kinase D promotes plasticity-induced F-actin stabilization in dendritic spines and regulates memory formation. J Cell Biol 2015; 210:771-83. [PMID: 26304723 PMCID: PMC4555815 DOI: 10.1083/jcb.201501114] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 07/23/2015] [Indexed: 02/07/2023] Open
Abstract
PKD regulates the stabilization of the F-actin network within dendritic spines upon chemically induced plasticity changes and is needed for proper hippocampal LTP and spatial memory formation. Actin turnover in dendritic spines influences spine development, morphology, and plasticity, with functional consequences on learning and memory formation. In nonneuronal cells, protein kinase D (PKD) has an important role in stabilizing F-actin via multiple molecular pathways. Using in vitro models of neuronal plasticity, such as glycine-induced chemical long-term potentiation (LTP), known to evoke synaptic plasticity, or long-term depolarization block by KCl, leading to homeostatic morphological changes, we show that actin stabilization needed for the enlargement of dendritic spines is dependent on PKD activity. Consequently, impaired PKD functions attenuate activity-dependent changes in hippocampal dendritic spines, including LTP formation, cause morphological alterations in vivo, and have deleterious consequences on spatial memory formation. We thus provide compelling evidence that PKD controls synaptic plasticity and learning by regulating actin stability in dendritic spines.
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Affiliation(s)
- Norbert Bencsik
- Department of Physiology and Neurobiology, Eötvös Loránd University, H-1117 Budapest, Hungary
| | - Zsófia Szíber
- Department of Physiology and Neurobiology, Eötvös Loránd University, H-1117 Budapest, Hungary
| | - Hanna Liliom
- Department of Physiology and Neurobiology, Eötvös Loránd University, H-1117 Budapest, Hungary
| | - Krisztián Tárnok
- Department of Physiology and Neurobiology, Eötvös Loránd University, H-1117 Budapest, Hungary
| | - Sándor Borbély
- Department of Physiology and Neurobiology, Eötvös Loránd University, H-1117 Budapest, Hungary
| | - Márton Gulyás
- MTA-ELTE-NAP B Neuronal Cell Biology Research Group, H-1117 Budapest, Hungary
| | - Anikó Rátkai
- Department of Physiology and Neurobiology, Eötvös Loránd University, H-1117 Budapest, Hungary
| | - Attila Szűcs
- MTA-ELTE-NAP B Neuronal Cell Biology Research Group, H-1117 Budapest, Hungary
| | - Diána Hazai-Novák
- Department of Anatomy and Histology, Faculty of Veterinary Science, Szent István University, H-1400 Budapest, Hungary
| | - Kornelia Ellwanger
- Institute of Cell Biology and Immunology, University of Stuttgart, D-70569 Stuttgart, Germany
| | - Bence Rácz
- Department of Anatomy and Histology, Faculty of Veterinary Science, Szent István University, H-1400 Budapest, Hungary
| | - Klaus Pfizenmaier
- Institute of Cell Biology and Immunology, University of Stuttgart, D-70569 Stuttgart, Germany
| | - Angelika Hausser
- Institute of Cell Biology and Immunology, University of Stuttgart, D-70569 Stuttgart, Germany
| | - Katalin Schlett
- Department of Physiology and Neurobiology, Eötvös Loránd University, H-1117 Budapest, Hungary MTA-ELTE-NAP B Neuronal Cell Biology Research Group, H-1117 Budapest, Hungary
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32
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Carrier N, Saland SK, Duclot F, He H, Mercer R, Kabbaj M. The Anxiolytic and Antidepressant-like Effects of Testosterone and Estrogen in Gonadectomized Male Rats. Biol Psychiatry 2015; 78:259-69. [PMID: 25683735 PMCID: PMC4501899 DOI: 10.1016/j.biopsych.2014.12.024] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 12/03/2014] [Accepted: 12/19/2014] [Indexed: 01/01/2023]
Abstract
BACKGROUND While the influence of testosterone levels on vulnerability to affective disorders is not straightforward, research suggests this hormone may confer some degree of resiliency in men. We recently demonstrated a role for the dentate gyrus in mediating testosterone's protective effects on depressive-like behavior in gonadectomized male rats. Here, testosterone may exert its effects through androgen receptor-mediated mechanisms or via local aromatization to estradiol. METHODS Gonadectomized male rats were implanted with a placebo, testosterone, or estradiol pellet, and subsequent protective anxiolytic- and antidepressant-like effects of testosterone and its aromatized metabolite, estradiol, were then investigated in the open field and sucrose preference tests, respectively. Moreover, their influence on gene expression in the hippocampus was analyzed by genome-wide complementary DNA microarray analysis. Finally, the contribution of testosterone's aromatization within the dentate gyrus was assessed by local infusion of the aromatase inhibitor fadrozole, whose efficacy was confirmed by liquid chromatography-tandem mass spectrometry. RESULTS Both hormones had antidepressant-like effects associated with a substantial overlap in transcriptional regulation, particularly in synaptic plasticity- and mitogen-activated protein kinase pathway-related genes. Further, chronic aromatase inhibition within the dentate gyrus blocked the protective effects of testosterone. CONCLUSIONS Both testosterone and estradiol exhibit anxiolytic- and antidepressant-like effects in gonadectomized male rats, while similarly regulating critical mediators of these behaviors, suggesting common underlying mechanisms. Accordingly, we demonstrated that testosterone's protective effects are mediated, in part, by its aromatization in the dentate gyrus. These findings thus provide further insight into a role for estradiol in mediating the protective anxiolytic- and antidepressant-like effects of testosterone.
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Affiliation(s)
| | | | | | | | | | - Mohamed Kabbaj
- Department of Biomedical Sciences, Program in Neurosciences.
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Kang J, Park H, Kim E. IRSp53/BAIAP2 in dendritic spine development, NMDA receptor regulation, and psychiatric disorders. Neuropharmacology 2015; 100:27-39. [PMID: 26275848 DOI: 10.1016/j.neuropharm.2015.06.019] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 06/26/2015] [Accepted: 06/28/2015] [Indexed: 01/08/2023]
Abstract
IRSp53 (also known as BAIAP2) is a multi-domain scaffolding and adaptor protein that has been implicated in the regulation of membrane and actin dynamics at subcellular structures, including filopodia and lamellipodia. Accumulating evidence indicates that IRSp53 is an abundant component of the postsynaptic density at excitatory synapses and an important regulator of actin-rich dendritic spines. In addition, IRSp53 has been implicated in diverse psychiatric disorders, including autism spectrum disorders, schizophrenia, and attention deficit/hyperactivity disorder. Mice lacking IRSp53 display enhanced NMDA (N-methyl-d-aspartate) receptor function accompanied by social and cognitive deficits, which are reversed by pharmacological suppression of NMDA receptor function. These results suggest the hypothesis that defective actin/membrane modulation in IRSp53-deficient dendritic spines may lead to social and cognitive deficits through NMDA receptor dysfunction. This article is part of the Special Issue entitled 'Synaptopathy--from Biology to Therapy'.
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Affiliation(s)
- Jaeseung Kang
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, South Korea
| | - Haram Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, South Korea
| | - Eunjoon Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, South Korea; Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon 305-701, South Korea.
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34
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Llano O, Smirnov S, Soni S, Golubtsov A, Guillemin I, Hotulainen P, Medina I, Nothwang HG, Rivera C, Ludwig A. KCC2 regulates actin dynamics in dendritic spines via interaction with β-PIX. J Cell Biol 2015; 209:671-86. [PMID: 26056138 PMCID: PMC4460141 DOI: 10.1083/jcb.201411008] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 04/27/2015] [Indexed: 02/07/2023] Open
Abstract
Chloride extrusion in mature neurons is largely mediated by the neuron-specific potassium-chloride cotransporter KCC2. In addition, independently of its chloride transport function, KCC2 regulates the development and morphology of dendritic spines through structural interactions with the actin cytoskeleton. The mechanism of this effect remains largely unknown. In this paper, we show a novel pathway for KCC2-mediated regulation of the actin cytoskeleton in neurons. We found that KCC2, through interaction with the b isoform of Rac/Cdc42 guanine nucleotide exchange factor β-PIX, regulates the activity of Rac1 GTPase and the phosphorylation of one of the major actin-regulating proteins, cofilin-1. KCC2-deficient neurons had abnormally high levels of phosphorylated cofilin-1. Consistently, dendritic spines of these neurons exhibited a large pool of stable actin, resulting in reduced spine motility and diminished density of functional synapses. In conclusion, we describe a novel signaling pathway that couples KCC2 to the cytoskeleton and regulates the formation of glutamatergic synapses.
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Affiliation(s)
- Olaya Llano
- Neuroscience Center, University of Helsinki, FI-00014 Helsinki, Finland
| | - Sergey Smirnov
- Neuroscience Center, University of Helsinki, FI-00014 Helsinki, Finland
| | - Shetal Soni
- Neuroscience Center, University of Helsinki, FI-00014 Helsinki, Finland
| | - Andrey Golubtsov
- Neuroscience Center, University of Helsinki, FI-00014 Helsinki, Finland
| | - Isabelle Guillemin
- Neurogenetics group, Center of Excellence Hearing4All, School of Medicine and Health Sciences and Research Center for Neurosensory Sciences, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
| | - Pirta Hotulainen
- Neuroscience Center, University of Helsinki, FI-00014 Helsinki, Finland
| | - Igor Medina
- Institut de Neurobiologie de la Méditerranée, Institut National de la Santé et de la Recherche Médicale Unité 901, 13009 Marseille, France Aix-Marseille Université, Unité Mixte de Recherche 901, 13273 Marseille, France
| | - Hans Gerd Nothwang
- Neurogenetics group, Center of Excellence Hearing4All, School of Medicine and Health Sciences and Research Center for Neurosensory Sciences, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
| | - Claudio Rivera
- Neuroscience Center, University of Helsinki, FI-00014 Helsinki, Finland Institut de Neurobiologie de la Méditerranée, Institut National de la Santé et de la Recherche Médicale Unité 901, 13009 Marseille, France Aix-Marseille Université, Unité Mixte de Recherche 901, 13273 Marseille, France
| | - Anastasia Ludwig
- Neuroscience Center, University of Helsinki, FI-00014 Helsinki, Finland
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35
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Sellers K, Raval P, Srivastava DP. Molecular signature of rapid estrogen regulation of synaptic connectivity and cognition. Front Neuroendocrinol 2015; 36:72-89. [PMID: 25159586 DOI: 10.1016/j.yfrne.2014.08.001] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 08/11/2014] [Accepted: 08/14/2014] [Indexed: 12/14/2022]
Abstract
There is now a growing appreciation that estrogens are capable of rapidly activating a number of signaling cascades within the central nervous system. In addition, there are an increasing number of studies reporting that 17β-estradiol, the major biologically active estrogen, can modulate cognition within a rapid time frame. Here we review recent studies that have begun to uncover the molecular and cellular framework which contributes to estrogens ability to rapidly modulate cognition. We first describe the mechanisms by which estrogen receptors (ERs) can couple to intracellular signaling cascades, either directly, or via the transactivation of other receptors. Subsequently, we review the evidence that estrogen can rapidly modulate both neuronal function and structure in the hippocampus and the cortex. Finally, we will discuss how estrogens may influence cognitive function through the modulation of neuronal structure, and the implications this may have on the treatment of a range of brain disorders.
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Affiliation(s)
- Katherine Sellers
- Department of Basic and Clinical Neuroscience, The James Black Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 9NU, UK
| | - Pooja Raval
- Department of Basic and Clinical Neuroscience, The James Black Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 9NU, UK
| | - Deepak P Srivastava
- Department of Basic and Clinical Neuroscience, The James Black Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 9NU, UK.
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36
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Jones KA, Eng AG, Raval P, Srivastava DP, Penzes P. Scaffold protein X11α interacts with kalirin-7 in dendrites and recruits it to Golgi outposts. J Biol Chem 2014; 289:35517-29. [PMID: 25378388 PMCID: PMC4271236 DOI: 10.1074/jbc.m114.587709] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Pyramidal neurons in the mammalian forebrain receive their synaptic inputs through their dendritic trees, and dendritic spines are the sites of most excitatory synapses. Dendritic spine structure is important for brain development and plasticity. Kalirin-7 is a guanine nucleotide-exchange factor for the small GTPase Rac1 and is a critical regulator of dendritic spine remodeling. The subcellular localization of kalirin-7 is thought to be important for regulating its function in neurons. A yeast two-hybrid screen has identified the adaptor protein X11α as an interacting partner of kalirin-7. Here, we show that kalirin-7 and X11α form a complex in the brain, and this interaction is mediated by the C terminus of kalirin-7. Kalirin-7 and X11α co-localize at excitatory synapses in cultured cortical neurons. Using time-lapse imaging of fluorescence recovery after photobleaching, we show that X11α is present in a mobile fraction of the postsynaptic density. X11α also localizes to Golgi outposts in dendrites, and its overexpression induces the removal of kalirin-7 from spines and accumulation of kalirin-7 in Golgi outposts. In addition, neurons overexpressing X11α displayed thinner spines. These data support a novel mechanism of regulation of kalirin-7 localization and function in dendrites, providing insight into signaling pathways underlying neuronal plasticity. Dissecting the molecular mechanisms of synaptic structural plasticity will improve our understanding of neuropsychiatric and neurodegenerative disorders, as kalirin-7 has been associated with schizophrenia and Alzheimer disease.
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Affiliation(s)
| | - Andrew G Eng
- the Interdepartmental Neuroscience Graduate Program, Northwestern University, Chicago, Illinois 60611, and
| | - Pooja Raval
- the Department of Neuroscience and Centre for the Cellular Basis of Behaviour, The James Black Centre, Institute of Psychiatry, King's College London, London SE5 9NU, United Kingdom
| | - Deepak P Srivastava
- From the Departments of Physiology and the Department of Neuroscience and Centre for the Cellular Basis of Behaviour, The James Black Centre, Institute of Psychiatry, King's College London, London SE5 9NU, United Kingdom
| | - Peter Penzes
- From the Departments of Physiology and Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611,
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37
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Russell TA, Blizinsky KD, Cobia DJ, Cahill ME, Xie Z, Sweet RA, Duan J, Gejman PV, Wang L, Csernansky JG, Penzes P. A sequence variant in human KALRN impairs protein function and coincides with reduced cortical thickness. Nat Commun 2014; 5:4858. [PMID: 25224588 PMCID: PMC4166532 DOI: 10.1038/ncomms5858] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 07/31/2014] [Indexed: 12/16/2022] Open
Abstract
Dendritic spine pathology is a key feature of several neuropsychiatric disorders. The Rac1 guanine nucleotide exchange factor kalirin-7 is critical for spine morphogenesis on cortical pyramidal neurons. Here we identify a rare coding variant in the KALRN gene region that encodes the catalytic domain, in a schizophrenia patient and his sibling with major depressive disorder. The D1338N substitution significantly diminished the protein's ability to catalyse the activation of Rac1. Contrary to wild-type kalirin-7, kalirin-7-D1338N failed to increase spine size and density. Both subjects carrying the polymorphism displayed reduced cortical volume in the superior temporal sulcus (STS), a region implicated in schizophrenia. Consistent with this, mice with reduced kalirin expression showed reduced neuropil volume in the rodent homologue of the STS. These data suggest that single amino acid changes in proteins involved in dendritic spine function can have significant effects on the structure and function of the cerebral cortex.
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Affiliation(s)
- Theron A Russell
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA
| | - Katherine D Blizinsky
- 1] Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA [2] Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA
| | - Derin J Cobia
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA
| | - Michael E Cahill
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA
| | - Zhong Xie
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA
| | - Robert A Sweet
- 1] Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA [2] Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA
| | - Jubao Duan
- 1] Department of Psychiatry and Behavioral Sciences, University of Chicago, Chicago, Illinois 60637, USA [2] Department of Psychiatry and Behavioral Sciences, NorthShore University HealthSystem, Evanston, Illinois 60208, USA
| | - Pablo V Gejman
- 1] Department of Psychiatry and Behavioral Sciences, University of Chicago, Chicago, Illinois 60637, USA [2] Department of Psychiatry and Behavioral Sciences, NorthShore University HealthSystem, Evanston, Illinois 60208, USA
| | - Lei Wang
- 1] Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA [2] Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA
| | - John G Csernansky
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA
| | - Peter Penzes
- 1] Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA [2] Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, USA
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38
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Stamatakou E, Salinas PC. Postsynaptic assembly: a role for Wnt signaling. Dev Neurobiol 2013; 74:818-27. [PMID: 24105999 PMCID: PMC4237178 DOI: 10.1002/dneu.22138] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2013] [Revised: 09/06/2013] [Accepted: 09/25/2013] [Indexed: 01/01/2023]
Abstract
Synapse formation requires the coordinated formation of the presynaptic terminal, containing the machinery for neurotransmitter release, and the postsynaptic side that possesses the machinery for neurotransmitter reception. For coordinated pre- and postsynaptic assembly signals across the synapse are required. Wnt secreted proteins are well-known synaptogenic factors that promote the recruitment of presynaptic components in diverse organisms. However, recent studies demonstrate that Wnts act directly onto the postsynaptic side at both central and peripheral synapses to promote postsynaptic development and synaptic strength. This review focuses on the role of Wnts in postsynaptic development at central synapses and the neuromuscular junction. © 2013 The Authors. Developmental Neurobiology Published by Wiley Periodicals, Inc. Develop Neurobiol 74: 818–827, 2014
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Affiliation(s)
- Eleanna Stamatakou
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, United Kingdom
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39
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Abstract
The ability to induce and study neuronal plasticity in single dendritic spines has greatly advanced our understanding of the signaling mechanisms that mediate long-term potentiation. It is now clear that in addition to compartmentalization by the individual spine, subcompartmentalization of biochemical signals occurs at specialized microdomains within the spine. The spatiotemporal coordination of these complex cascades allows for the concomitant remodeling of the postsynaptic density and actin spinoskeleton and for the regulation of membrane traffic to express functional and structural plasticity. Here, we highlight recent findings in the signaling cascades at spine microdomains as well as the challenges and approaches to studying plasticity at the spine level.
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Affiliation(s)
- Lesley A Colgan
- Neuronal Signal Transduction, Max Planck Florida Institute for Neuroscience, Jupiter, Florida 33458; ,
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40
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Srivastava DP, Woolfrey KM, Penzes P. Insights into rapid modulation of neuroplasticity by brain estrogens. Pharmacol Rev 2013; 65:1318-50. [PMID: 24076546 PMCID: PMC3799233 DOI: 10.1124/pr.111.005272] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Converging evidence from cellular, electrophysiological, anatomic, and behavioral studies suggests that the remodeling of synapse structure and function is a critical component of cognition. This modulation of neuroplasticity can be achieved through the actions of numerous extracellular signals. Moreover, it is thought that it is the integration of different extracellular signals regulation of neuroplasticity that greatly influences cognitive function. One group of signals that exerts powerful effects on multiple neurologic processes is estrogens. Classically, estrogens have been described to exert their effects over a period of hours to days. However, there is now increasing evidence that estrogens can rapidly influence multiple behaviors, including those that require forebrain neural circuitry. Moreover, these effects are found in both sexes. Critically, it is now emerging that the modulation of cognition by rapid estrogenic signaling is achieved by activation of specific signaling cascades and regulation of synapse structure and function, cumulating in the rewiring of neural circuits. The importance of understanding the rapid effects of estrogens on forebrain function and circuitry is further emphasized as investigations continue to consider the potential of estrogenic-based therapies for neuropathologies. This review focuses on how estrogens can rapidly influence cognition and the emerging mechanisms that underlie these effects. We discuss the potential sources and the biosynthesis of estrogens within the brain and the consequences of rapid estrogenic-signaling on the remodeling of neural circuits. Furthermore, we argue that estrogens act via distinct signaling pathways to modulate synapse structure and function in a manner that may vary with cell type, developmental stage, and sex. Finally, we present a model in which the coordination of rapid estrogenic-signaling and activity-dependent stimuli can result in long-lasting changes in neural circuits, contributing to cognition, with potential relevance for the development of novel estrogenic-based therapies for neurodevelopmental or neurodegenerative disorders.
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Affiliation(s)
- Deepak P Srivastava
- Department of Neuroscience & Centre for the Cellular Basis of Behaviour, 125 Coldharbour Lane, The James Black Centre, Institute of Psychiatry, King's College London, London, SE5 9NU, UK.
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41
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Romero AM, Renau-Piqueras J, Pilar Marin M, Timoneda J, Berciano MT, Lafarga M, Esteban-Pretel G. Chronic alcohol alters dendritic spine development in neurons in primary culture. Neurotox Res 2013; 24:532-48. [PMID: 23820986 DOI: 10.1007/s12640-013-9409-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 06/07/2013] [Accepted: 06/21/2013] [Indexed: 12/24/2022]
Abstract
Dendritic spines are specialised membrane protrusions of neuronal dendrites that receive the majority of excitatory synaptic inputs. Abnormal changes in their density, size and morphology have been associated with various neurological and psychiatric disorders, including those deriving from drug addiction. Dendritic spine formation, morphology and synaptic functions are governed by the actin cytoskeleton. Previous in vivo studies have shown that ethanol alters the number and morphology of spines, although the mechanisms underlying these alterations remain unknown. It has also been described how chronic ethanol exposure affects the levels, assembly and cellular organisation of the actin cytoskeleton in hippocampal neurons in primary culture. Therefore, we hypothesised that the ethanol-induced alterations in the number and shape of dendritic spines are due to alterations in the mechanisms regulating actin cytoskeleton integrity. The results presented herein show that chronic exposure to moderate levels of alcohol (30 mM) during the first 2 weeks of culture reduces dendritic spine density and alters the proportion of the different morphologies of these structures in hippocampal neurons, which affects the formation of mature spines. Apparently, these effects are associated with an increase in the G-actin/F-actin ratio due to a reduction of the F-actin fraction, leading to changes in the levels of the different factors regulating the organisation of this cytoskeletal component. The data presented herein indicate that these effects occur between weeks 1 and 2 of culture, an important period in dendritic spines development. These changes may be related to the dysfunction in the memory and learning processes present in children prenatally exposed to ethanol.
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Affiliation(s)
- Ana M Romero
- Sección de Biología y Patología Celular, Centro de Investigación, Hospital Universitario ''La Fe'', Avenida Campanar 21, 46009, Valencia, Spain
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42
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Rácz B, Weinberg RJ. Microdomains in forebrain spines: an ultrastructural perspective. Mol Neurobiol 2013; 47:77-89. [PMID: 22983912 PMCID: PMC3538892 DOI: 10.1007/s12035-012-8345-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2012] [Accepted: 08/27/2012] [Indexed: 12/21/2022]
Abstract
Glutamatergic axons in the mammalian forebrain terminate predominantly onto dendritic spines. Long-term changes in the efficacy of these excitatory synapses are tightly coupled to changes in spine morphology. The reorganization of the actin cytoskeleton underlying this spine "morphing" involves numerous proteins that provide the machinery needed for adaptive cytoskeletal remodeling. Here, we review recent literature addressing the chemical architecture of the spine, focusing mainly on actin-binding proteins (ABPs). Accumulating evidence suggests that ABPs are organized into functionally distinct microdomains within the spine cytoplasm. This functional compartmentalization provides a structural basis for regulation of the spinoskeleton, offering a novel window into mechanisms underlying synaptic plasticity.
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Affiliation(s)
- Bence Rácz
- Department of Anatomy and Histology, Faculty of Veterinary Science, Szent István University, 1078, Budapest, Hungary.
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43
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Lynch G, Kramár EA, Babayan AH, Rumbaugh G, Gall CM. Differences between synaptic plasticity thresholds result in new timing rules for maximizing long-term potentiation. Neuropharmacology 2013; 64:27-36. [PMID: 22820276 PMCID: PMC3445784 DOI: 10.1016/j.neuropharm.2012.07.006] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2012] [Revised: 06/28/2012] [Accepted: 07/01/2012] [Indexed: 01/25/2023]
Abstract
The fundamental observation that the temporal spacing of learning episodes plays a critical role in the efficiency of memory encoding has had little effect on either research on long-term potentiation (LTP) or efforts to develop cognitive enhancers. Here we review recent findings describing a spaced trials phenomenon for LTP that appears to be related to recent evidence that plasticity thresholds differ between synapses in the adult hippocampus. Results of tests with one memory enhancing drug suggest that the compound potently facilitates LTP via effects on 'high threshold' synapses and thus alters the temporally extended timing rules. Possible implications of these results for our understanding of LTP substrates, neurobiological contributors to the distributed practice effect, and the consequences of memory enhancement are discussed. This article is part of a Special Issue entitled 'Cognitive Enhancers'.
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Affiliation(s)
- Gary Lynch
- Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697-4260 USA
- Department of Anatomy and Neurobiology, University of California, Irvine, CA 92697-1275 USA
| | - Enikö A. Kramár
- Department of Anatomy and Neurobiology, University of California, Irvine, CA 92697-1275 USA
| | - Alex H. Babayan
- Department of Anatomy and Neurobiology, University of California, Irvine, CA 92697-1275 USA
| | - Gavin Rumbaugh
- Department of Neuroscience, The Scripps Research Institute, Jupiter FL 33458 USA
| | - Christine M. Gall
- Department of Anatomy and Neurobiology, University of California, Irvine, CA 92697-1275 USA
- Department of Neurobiology and Behavior, University of California, Irvine, CA 92697-4450 USA
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44
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Chen YK, Chen CY, Hu HT, Hsueh YP. CTTNBP2, but not CTTNBP2NL, regulates dendritic spinogenesis and synaptic distribution of the striatin-PP2A complex. Mol Biol Cell 2012; 23:4383-92. [PMID: 23015759 PMCID: PMC3496612 DOI: 10.1091/mbc.e12-05-0365] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Cortactin-binding protein 2 (CTTNBP2) interacts with cortactin to regulate cortactin mobility and control dendritic spine formation. CTTNBP2 has also been associated with autistic spectrum disorder. The regulation of dendritic spinogenesis could explain the association of CTTNBP2 with autism. Sequence comparison has indicated that CTTNBP2 N-terminal-like protein (CTTNBP2NL) is a CTTNBP2 homologue. To confirm the specific effect of CTTNBP2 on dendritic spinogenesis, here we investigate whether CTTNBP2NL has a similar function to CTTNBP2. Although both CTTNBP2 and CTTNBP2NL interact with cortactin, CTTNBP2NL is associated with stress fibers, whereas CTTNBP2 is distributed to the cortex and intracellular puncta. We also provide evidence that CTTNBP2, but not CTTNBP2NL, is predominantly expressed in the brain. CTTNBP2NL does not show any activity in the regulation of dendritic spinogenesis. In addition to spine morphology, CTTNBP2 is also found to regulate the synaptic distribution of striatin and zinedin (the regulatory B subunits of protein phosphatase 2A [PP2A]), which interact with CTTNBP2NL in HEK293 cells. The association between CTTNBP2 and striatin/zinedin suggests that CTTNBP2 targets the PP2A complex to dendritic spines. Thus we propose that the interactions of CTTNBP2 and cortactin and the PP2A complex regulate spine morphogenesis and synaptic signaling.
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Affiliation(s)
- Yi-Kai Chen
- Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan
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45
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Tretter V, Mukherjee J, Maric HM, Schindelin H, Sieghart W, Moss SJ. Gephyrin, the enigmatic organizer at GABAergic synapses. Front Cell Neurosci 2012; 6:23. [PMID: 22615685 PMCID: PMC3351755 DOI: 10.3389/fncel.2012.00023] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2011] [Accepted: 04/23/2012] [Indexed: 11/17/2022] Open
Abstract
GABAA receptors are clustered at synaptic sites to achieve a high density of postsynaptic receptors opposite the input axonal terminals. This allows for an efficient propagation of GABA mediated signals, which mostly result in neuronal inhibition. A key organizer for inhibitory synaptic receptors is the 93 kDa protein gephyrin that forms oligomeric superstructures beneath the synaptic area. Gephyrin has long been known to be directly associated with glycine receptor β subunits that mediate synaptic inhibition in the spinal cord. Recently, synaptic GABAA receptors have also been shown to directly interact with gephyrin and interaction sites have been identified and mapped within the intracellular loops of the GABAA receptor α1, α2, and α3 subunits. Gephyrin-binding to GABAA receptors seems to be at least one order of magnitude weaker than to glycine receptors (GlyRs) and most probably is regulated by phosphorylation. Gephyrin not only has a structural function at synaptic sites, but also plays a crucial role in synaptic dynamics and is a platform for multiple protein-protein interactions, bringing receptors, cytoskeletal proteins and downstream signaling proteins into close spatial proximity.
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Affiliation(s)
- Verena Tretter
- Department of Biochemistry and Molecular Biology, Center for Brain Research, Medical University Vienna Vienna, Austria
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