1
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Li S, Li J, Yang X, Huang J, Feng S, Xie Z, Yang N, Wang Y, Zhou N. Peripheral nervous system lymphatic vessels: A simple delivery route to promote nerve regeneration. Exp Neurol 2024; 377:114783. [PMID: 38688418 DOI: 10.1016/j.expneurol.2024.114783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 03/09/2024] [Accepted: 04/18/2024] [Indexed: 05/02/2024]
Abstract
The structural and functional features of lymphatic vessels in the peripheral nervous system (pLVs) is still unclear. Here, we clarify the existence of pLVs in rats, PROX1-EGFP transgenic mice and human, and exhibit a clear three-dimensional structure for helping understand its structural features. Moreover, two specific phenotypes of lymphatics endothelial cells (Rnd1Hi LECs and Ccl21Hi LECs) in peripheral nerves are well characterized by single-cell sequencing. Subsequently, the ability of trans-lymphatic delivery to peripheral nerves via pLVs has been dynamically demonstrated. After peripheral nerve injury (PNI), extensive lymphangiogenesis occurs in the lesion area and further enhances the efficiency of retrograde lymphatic-nerve transport. In PNI animal models, subcutaneously footpad-injected exosomes are efficiently delivered to sciatic nerve via pLVs which can promote nerve regeneration. The trans-lymphatic delivery to peripheral nerves via pLVs can subtly bypass BNB which provides an easy and alternative delivery route for PNI treatment.
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Affiliation(s)
- Senrui Li
- Department of Orthopedics, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou 450052, China
| | - Jiangnan Li
- Department of Orthopedics, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou 450052, China
| | - Xiaoqi Yang
- Department of Orthopedics, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou 450052, China; State Key Laboratory of Drug Research, Molecular Imaging Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Jinsheng Huang
- Department of Orthopedics, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou 450052, China
| | - Shuai Feng
- Department of Hand and Podiatric Surgery, Henan Provincial People's Hospital, Zhengzhou 450000, China
| | - Zhenjun Xie
- Department of Hand and Podiatric Surgery, Henan Provincial People's Hospital, Zhengzhou 450000, China
| | - Ningning Yang
- Department of Emergency, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou 450052, China.
| | - Yuanyi Wang
- Department of Spinal Surgery, The First Hospital of Jilin University, Orthopedics Center, Jilin University, Changchun 130021, China.
| | - Nan Zhou
- Department of Orthopedics, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou 450052, China.
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2
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Huang H, Wang S, Guan Y, Ren J, Liu X. Molecular basis and current insights of atypical Rho small GTPase in cancer. Mol Biol Rep 2024; 51:141. [PMID: 38236467 DOI: 10.1007/s11033-023-09140-7] [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: 09/17/2023] [Accepted: 12/11/2023] [Indexed: 01/19/2024]
Abstract
Atypical Rho GTPases are a subtype of the Rho GTPase family that are involved in diverse cellular processes. The typical Rho GTPases, led by RhoA, Rac1 and Cdc42, have been well studied, while relative studies on atypical Rho GTPases are relatively still limited and have great exploration potential. With the increase in studies, current evidence suggests that atypical Rho GTPases regulate multiple biological processes and play important roles in the occurrence and development of human cancers. Therefore, this review mainly discusses the molecular basis of atypical Rho GTPases and their roles in cancer. We summarize the sequence characteristics, subcellular localization and biological functions of each atypical Rho GTPase. Moreover, we review the recent advances and potential mechanisms of atypical Rho GTPases in the development of multiple cancers. A comprehensive understanding and extensive exploration of the biological functions of atypical Rho GTPases and their molecular mechanisms in tumors will provide important insights into the pathophysiology of tumors and the development of cancer therapeutic strategies.
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Affiliation(s)
- Hua Huang
- Center of Excellence for Environmental Safety and Biological Effects, Faculty of Environment and Life, Beijing International Science and Technology Cooperation Base for Antiviral Drugs, Beijing University of Technology, Beijing, 100124, China
| | - Sijia Wang
- Center of Excellence for Environmental Safety and Biological Effects, Faculty of Environment and Life, Beijing International Science and Technology Cooperation Base for Antiviral Drugs, Beijing University of Technology, Beijing, 100124, China
| | - Yifei Guan
- Center of Excellence for Environmental Safety and Biological Effects, Faculty of Environment and Life, Beijing International Science and Technology Cooperation Base for Antiviral Drugs, Beijing University of Technology, Beijing, 100124, China
| | - Jing Ren
- Department of Plastic and Reconstructive Surgery, The First Medical Center, Chinese PLA (People's Liberation Army) General Hospital, Beijing, 100853, China.
| | - Xinhui Liu
- Center of Excellence for Environmental Safety and Biological Effects, Faculty of Environment and Life, Beijing International Science and Technology Cooperation Base for Antiviral Drugs, Beijing University of Technology, Beijing, 100124, China.
- Faculty of Environment and Life, Beijing University of Technology, Beijing, 100124, China.
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3
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Abushalbaq O, Baek J, Yaron A, Tran TS. Balancing act of small GTPases downstream of plexin-A4 signaling motifs promotes dendrite elaboration in mammalian cortical neurons. Sci Signal 2024; 17:eadh7673. [PMID: 38227686 DOI: 10.1126/scisignal.adh7673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 12/21/2023] [Indexed: 01/18/2024]
Abstract
The precise development of neuronal morphologies is crucial to the establishment of synaptic circuits and, ultimately, proper brain function. Signaling by the axon guidance cue semaphorin 3A (Sema3A) and its receptor complex of neuropilin-1 and plexin-A4 has multifunctional outcomes in neuronal morphogenesis. Downstream activation of the RhoGEF FARP2 through interaction with the lysine-arginine-lysine motif of plexin-A4 and consequent activation of the small GTPase Rac1 promotes dendrite arborization, but this pathway is dispensable for axon repulsion. Here, we investigated the interplay of small GTPase signaling mechanisms underlying Sema3A-mediated dendritic elaboration in mouse layer V cortical neurons in vitro and in vivo. Sema3A promoted the binding of the small GTPase Rnd1 to the amino acid motif lysine-valine-serine (LVS) in the cytoplasmic domain of plexin-A4. Rnd1 inhibited the activity of the small GTPase RhoA and the kinase ROCK, thus supporting the activity of the GTPase Rac1, which permitted the growth and branching of dendrites. Overexpression of a dominant-negative RhoA, a constitutively active Rac1, or the pharmacological inhibition of ROCK activity rescued defects in dendritic elaboration in neurons expressing a plexin-A4 mutant lacking the LVS motif. Our findings provide insights into the previously unappreciated balancing act between Rho and Rac signaling downstream of specific motifs in plexin-A4 to mediate Sema3A-dependent dendritic elaboration in mammalian cortical neuron development.
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Affiliation(s)
- Oday Abushalbaq
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA
| | - Jiyeon Baek
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA
| | - Avraham Yaron
- Department of Biomolecular Sciences and Department of Molecular Neuroscience, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Tracy S Tran
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA
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4
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Cueto-Ureña C, Mocholí E, Escrivá-Fernández J, González-Granero S, Sánchez-Hernández S, Solana-Orts A, Ballester-Lurbe B, Benabdellah K, Guasch RM, García-Verdugo JM, Martín F, Coffer PJ, Pérez-Roger I, Poch E. Rnd3 Expression is Necessary to Maintain Mitochondrial Homeostasis but Dispensable for Autophagy. Front Cell Dev Biol 2022; 10:834561. [PMID: 35832788 PMCID: PMC9271580 DOI: 10.3389/fcell.2022.834561] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 05/27/2022] [Indexed: 11/13/2022] Open
Abstract
Autophagy is a highly conserved process that mediates the targeting and degradation of intracellular components to lysosomes, contributing to the maintenance of cellular homeostasis and to obtaining energy, which ensures viability under stress conditions. Therefore, autophagy defects are common to different neurodegenerative disorders. Rnd3 belongs to the family of Rho GTPases, involved in the regulation of actin cytoskeleton dynamics and important in the modulation of cellular processes such as migration and proliferation. Murine models have shown that Rnd3 is relevant for the correct development and function of the Central Nervous System and lack of its expression produces several motor alterations and neural development impairment. However, little is known about the molecular events through which Rnd3 produces these phenotypes. Interestingly we have observed that Rnd3 deficiency correlates with the appearance of autophagy impairment profiles and irregular mitochondria. In this work, we have explored the impact of Rnd3 loss of expression in mitochondrial function and autophagy, using a Rnd3 KO CRISPR cell model. Rnd3 deficient cells show no alterations in autophagy and mitochondria turnover is not impaired. However, Rnd3 KO cells have an altered mitochondria oxidative metabolism, resembling the effect caused by oxidative stress. In fact, lack of Rnd3 expression makes these cells strictly dependent on glycolysis to obtain energy. Altogether, our results demonstrate that Rnd3 is relevant to maintain mitochondria function, suggesting a possible relationship with neurodegenerative diseases.
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Affiliation(s)
- Cristina Cueto-Ureña
- School of Health Sciences, Universidad CEU Cardenal Herrera, CEU Universities, Valencia, Spain
| | - Enric Mocholí
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, Netherlands
| | - Josep Escrivá-Fernández
- School of Health Sciences, Universidad CEU Cardenal Herrera, CEU Universities, Valencia, Spain
| | - Susana González-Granero
- Laboratorio de Neurobiologia Comparada, Instituto Cavanilles de Biodiversidad y Biologia Evolutiva, Universidad de Valencia and CIBER de Enfermedades Neurodegenerativas (CIBERNED), Valencia, Spain
| | - Sabina Sánchez-Hernández
- Genomic Medicine Department, GENYO, Centre for Genomics and Oncological Research, Pfizer-University of Granada-Andalusian Regional Government, Health Sciences Technology Park, Granada, Spain
| | - Amalia Solana-Orts
- School of Health Sciences, Universidad CEU Cardenal Herrera, CEU Universities, Valencia, Spain
| | - Begoña Ballester-Lurbe
- School of Health Sciences, Universidad CEU Cardenal Herrera, CEU Universities, Valencia, Spain
| | - Karim Benabdellah
- Genomic Medicine Department, GENYO, Centre for Genomics and Oncological Research, Pfizer-University of Granada-Andalusian Regional Government, Health Sciences Technology Park, Granada, Spain
| | - Rosa M. Guasch
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Valencia, Valencia, Spain
| | - José Manuel García-Verdugo
- Laboratorio de Neurobiologia Comparada, Instituto Cavanilles de Biodiversidad y Biologia Evolutiva, Universidad de Valencia and CIBER de Enfermedades Neurodegenerativas (CIBERNED), Valencia, Spain
| | - Francisco Martín
- Genomic Medicine Department, GENYO, Centre for Genomics and Oncological Research, Pfizer-University of Granada-Andalusian Regional Government, Health Sciences Technology Park, Granada, Spain
| | - Paul J. Coffer
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, Netherlands
| | - Ignacio Pérez-Roger
- School of Health Sciences, Universidad CEU Cardenal Herrera, CEU Universities, Valencia, Spain
- *Correspondence: Ignacio Pérez-Roger, ; Enric Poch,
| | - Enric Poch
- School of Health Sciences, Universidad CEU Cardenal Herrera, CEU Universities, Valencia, Spain
- *Correspondence: Ignacio Pérez-Roger, ; Enric Poch,
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5
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Luo YF, Ye XX, Fang YZ, Li MD, Xia ZX, Liu JM, Lin XS, Huang Z, Zhu XQ, Huang JJ, Tan DL, Zhang YF, Liu HP, Zhou J, Shen ZC. mTORC1 Signaling Pathway Mediates Chronic Stress-Induced Synapse Loss in the Hippocampus. Front Pharmacol 2022; 12:801234. [PMID: 34987410 PMCID: PMC8722735 DOI: 10.3389/fphar.2021.801234] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 12/06/2021] [Indexed: 11/13/2022] Open
Abstract
Background: The mechanistic target of rapamycin complex 1 (mTORC1) signaling has served as a promising target for therapeutic intervention of major depressive disorder (MDD), but the mTORC1 signaling underlying MDD has not been well elucidated. In the present study, we investigated whether mTORC1 signaling pathway mediates synapse loss induced by chronic stress in the hippocampus. Methods: Chronic restraint stress-induced depression-like behaviors were tested by behavior tests (sucrose preference test, forced swim test and tail suspension test). Synaptic proteins and alternations of phosphorylation levels of mTORC1 signaling-associated molecules were measured using Western blotting. In addition, mRNA changes of immediate early genes (IEGs) and glutamate receptors were measured by RT-PCR. Rapamycin was used to explore the role of mTORC1 signaling in the antidepressant effects of fluoxetine. Results: After successfully establishing the chronic restraint stress paradigm, we observed that the mRNA levels of some IEGs were significantly changed, indicating the activation of neurons and protein synthesis alterations. Then, there was a significant downregulation of glutamate receptors and postsynaptic density protein 95 at protein and mRNA levels. Additionally, synaptic fractionation assay revealed that chronic stress induced synapse loss in the dorsal and ventral hippocampus. Furthermore, these effects were associated with the mTORC1 signaling pathway-mediated protein synthesis, and subsequently the phosphorylation of associated downstream signaling targets was reduced after chronic stress. Finally, we found that intracerebroventricular infusion of rapamycin simulated depression-like behavior and also blocked the antidepressant effects of fluoxetine. Conclusion: Overall, our study suggests that mTORC1 signaling pathway plays a critical role in mediating synapse loss induced by chronic stress, and has part in the behavioral effects of antidepressant treatment.
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Affiliation(s)
- Yu-Fei Luo
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China.,Clinical Medical Research Center, Hunan Prevention and Treatment Institute for Occupational Diseases, Changsha, China
| | - Xiao-Xia Ye
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Ying-Zhao Fang
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Meng-Die Li
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Zhi-Xuan Xia
- Department of Pharmacology, School of Basic Medicine and Life Science, Hainan Medical University, Haikou, China
| | - Jian-Min Liu
- Department of Pharmacy, Wuhan No. 1 Hospital, Wuhan, China
| | - Xiao-Shan Lin
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Zhen Huang
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Xiao-Qian Zhu
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Jun-Jie Huang
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Dong-Lin Tan
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yu-Fei Zhang
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Hai-Ping Liu
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
| | - Jun Zhou
- Translational Medicine Center, Xi'an Chest Hospital, Medical College of Xi'an Jiaotong University, Xi'an, China
| | - Zu-Cheng Shen
- Department of Pharmacology, School of Pharmacy, Fujian Medical University, Fuzhou, China
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6
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Liu X, Zhang H, Xue Q, Pan W, Zhang A. In silico health effect prioritization of environmental chemicals through transcriptomics data exploration from a chemo-centric view. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 762:143082. [PMID: 33143927 DOI: 10.1016/j.scitotenv.2020.143082] [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: 08/09/2020] [Revised: 10/11/2020] [Accepted: 10/11/2020] [Indexed: 06/11/2023]
Abstract
With the explosive growth of synthetic compounds, the health effects caused by exogenous chemical exposure have attracted more and more public attention. The prediction of health effect is a never-ending story. Collective resource of transcriptomics data offers an opportunity to understand and identify the multiple health effects of small molecule. Inspired by the fact that environmental chemicals of high health risk frequently share both similar gene expression profile and common structural feature of certain drugs, we here propose a novel computational effect prioritization method for environmental chemicals through transcriptomics data exploration from a chemo-centric view. Specifically, non-negative matrix factorization (NMF) method has been adopted to get the association network linking structural features with transcriptomics characteristics of drugs with specific effects. The model yields 13 pivotal types of effects, so-called components, that represent drug categories with common chemo- and geno- type features. Moreover, the established model effectively prioritizes potential toxic effects for the external chemicals from the endocrine disruptor screening program (EDSP) for their potential estrogenicity and other verified risks. Even if only the highest priority is set for the estrogenic effect, the precision and recall can reach 0.76 and 0.77 respectively for these chemicals. Our effort provides a successful endeavor as to profile potential toxic effects simultaneously for environmental chemicals using both chemical and omics data.
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Affiliation(s)
- Xian Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, PR China.
| | - Huazhou Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, PR China.
| | - Qiao Xue
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China.
| | - Wenxiao Pan
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China.
| | - Aiqian Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, PR China; Institute of Environment and Health, Jianghan University, Wuhan 430056, PR China.
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7
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Kobow K, Jabari S, Pieper T, Kudernatsch M, Polster T, Woermann FG, Kalbhenn T, Hamer H, Rössler K, Mühlebner A, Spliet WGM, Feucht M, Hou Y, Stichel D, Korshunov A, Sahm F, Coras R, Blümcke I, von Deimling A. Mosaic trisomy of chromosome 1q in human brain tissue associates with unilateral polymicrogyria, very early-onset focal epilepsy, and severe developmental delay. Acta Neuropathol 2020; 140:881-891. [PMID: 32979071 PMCID: PMC7666281 DOI: 10.1007/s00401-020-02228-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 09/16/2020] [Accepted: 09/16/2020] [Indexed: 02/06/2023]
Abstract
Polymicrogyria (PMG) is a developmental cortical malformation characterized by an excess of small and frustrane gyration and abnormal cortical lamination. PMG frequently associates with seizures. The molecular pathomechanisms underlying PMG development are not yet understood. About 40 genes have been associated with PMG, and small copy number variations have also been described in selected patients. We recently provided evidence that epilepsy-associated structural brain lesions can be classified based on genomic DNA methylation patterns. Here, we analyzed 26 PMG patients employing array-based DNA methylation profiling on formalin-fixed paraffin-embedded material. A series of 62 well-characterized non-PMG cortical malformations (focal cortical dysplasia type 2a/b and hemimegalencephaly), temporal lobe epilepsy, and non-epilepsy autopsy controls was used as reference cohort. Unsupervised dimensionality reduction and hierarchical cluster analysis of DNA methylation profiles showed that PMG formed a distinct DNA methylation class. Copy number profiling from DNA methylation data identified a uniform duplication spanning the entire long arm of chromosome 1 in 7 out of 26 PMG patients, which was verified by additional fluorescence in situ hybridization analysis. In respective cases, about 50% of nuclei in the center of the PMG lesion were 1q triploid. No chromosomal imbalance was seen in adjacent, architecturally normal-appearing tissue indicating mosaicism. Clinically, PMG 1q patients presented with a unilateral frontal or hemispheric PMG without hemimegalencephaly, a severe form of intractable epilepsy with seizure onset in the first months of life, and severe developmental delay. Our results show that PMG can be classified among other structural brain lesions according to their DNA methylation profile. One subset of PMG with distinct clinical features exhibits a duplication of chromosomal arm 1q.
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Affiliation(s)
- Katja Kobow
- Department of Neuropathology, Institute of Neuropathology, Affiliated Partner of the ERN EpiCARE, Universitätsklinikum Erlangen, Friedrich-Alexander-University of Erlangen-Nürnberg (FAU), Schwabachanlage 6, 91054, Erlangen, Germany.
| | - Samir Jabari
- Department of Neuropathology, Institute of Neuropathology, Affiliated Partner of the ERN EpiCARE, Universitätsklinikum Erlangen, Friedrich-Alexander-University of Erlangen-Nürnberg (FAU), Schwabachanlage 6, 91054, Erlangen, Germany
| | - Tom Pieper
- Department of Neurology, Schön Klinik Vogtareuth, Vogtareuth, Germany
| | - Manfred Kudernatsch
- Department of Neurosurgery and Epilepsy Surgery, Schön Klinik Vogtareuth, Vogtareuth, Germany
- Research Institute "Rehabilitation, Transition, Palliation", PMU Salzburg, Salzburg, Austria
| | - Tilman Polster
- Epilepsy Center Bethel, Krankenhaus Mara, Bielefeld, Germany
| | | | - Thilo Kalbhenn
- Department of Neurosurgery, Evangelisches Klinikum Bethel, Bielefeld, Germany
| | - Hajo Hamer
- Department of Neurology, Epilepsy Center, Universitätsklinikum Erlangen, Friedrich-Alexander-University of Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Karl Rössler
- Department of Neurosurgery, Universitätsklinikum Erlangen, Friedrich-Alexander-University of Erlangen-Nürnberg (FAU), Erlangen, Germany
- Department of Neurosurgery, Medical University of Vienna, Vienna, Austria
| | - Angelika Mühlebner
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Wim G M Spliet
- Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Martha Feucht
- Department of Pediatrics and Adolescent Medicine, Affiliated Partner of the ERN EpiCARE, Medical University Vienna, Vienna, Austria
| | - Yanghao Hou
- Department of Neuropathology, Universitätsklinikum Heidelberg, and, CCU Neuropathology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Damian Stichel
- Department of Neuropathology, Universitätsklinikum Heidelberg, and, CCU Neuropathology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Andrey Korshunov
- Department of Neuropathology, Universitätsklinikum Heidelberg, and, CCU Neuropathology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Felix Sahm
- Department of Neuropathology, Universitätsklinikum Heidelberg, and, CCU Neuropathology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Roland Coras
- Department of Neuropathology, Institute of Neuropathology, Affiliated Partner of the ERN EpiCARE, Universitätsklinikum Erlangen, Friedrich-Alexander-University of Erlangen-Nürnberg (FAU), Schwabachanlage 6, 91054, Erlangen, Germany
| | - Ingmar Blümcke
- Department of Neuropathology, Institute of Neuropathology, Affiliated Partner of the ERN EpiCARE, Universitätsklinikum Erlangen, Friedrich-Alexander-University of Erlangen-Nürnberg (FAU), Schwabachanlage 6, 91054, Erlangen, Germany
| | - Andreas von Deimling
- Department of Neuropathology, Universitätsklinikum Heidelberg, and, CCU Neuropathology, German Cancer Research Center (DKFZ), Heidelberg, Germany
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8
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Lavanderos B, Silva I, Cruz P, Orellana-Serradell O, Saldías MP, Cerda O. TRP Channels Regulation of Rho GTPases in Brain Context and Diseases. Front Cell Dev Biol 2020; 8:582975. [PMID: 33240883 PMCID: PMC7683514 DOI: 10.3389/fcell.2020.582975] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 10/05/2020] [Indexed: 12/13/2022] Open
Abstract
Neurological and neuropsychiatric disorders are mediated by several pathophysiological mechanisms, including developmental and degenerative abnormalities caused primarily by disturbances in cell migration, structural plasticity of the synapse, and blood-vessel barrier function. In this context, critical pathways involved in the pathogenesis of these diseases are related to structural, scaffolding, and enzymatic activity-bearing proteins, which participate in Ca2+- and Ras Homologs (Rho) GTPases-mediated signaling. Rho GTPases are GDP/GTP binding proteins that regulate the cytoskeletal structure, cellular protrusion, and migration. These proteins cycle between GTP-bound (active) and GDP-bound (inactive) states due to their intrinsic GTPase activity and their dynamic regulation by GEFs, GAPs, and GDIs. One of the most important upstream inputs that modulate Rho GTPases activity is Ca2+ signaling, positioning ion channels as pivotal molecular entities for Rho GTPases regulation. Multiple non-selective cationic channels belonging to the Transient Receptor Potential (TRP) family participate in cytoskeletal-dependent processes through Ca2+-mediated modulation of Rho GTPases. Moreover, these ion channels have a role in several neuropathological events such as neuronal cell death, brain tumor progression and strokes. Although Rho GTPases-dependent pathways have been extensively studied, how they converge with TRP channels in the development or progression of neuropathologies is poorly understood. Herein, we review recent evidence and insights that link TRP channels activity to downstream Rho GTPase signaling or modulation. Moreover, using the TRIP database, we establish associations between possible mediators of Rho GTPase signaling with TRP ion channels. As such, we propose mechanisms that might explain the TRP-dependent modulation of Rho GTPases as possible pathways participating in the emergence or maintenance of neuropathological conditions.
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Affiliation(s)
- Boris Lavanderos
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Santiago, Chile
| | - Ian Silva
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Santiago, Chile
| | - Pablo Cruz
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Santiago, Chile
| | - Octavio Orellana-Serradell
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Santiago, Chile
| | - María Paz Saldías
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Santiago, Chile
| | - Oscar Cerda
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Santiago, Chile.,The Wound Repair, Treatment and Health (WoRTH) Initiative, Santiago, Chile
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9
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Abstract
Rnd proteins constitute a subfamily of Rho GTPases represented in mammals by Rnd1, Rnd2 and Rnd3. Despite their GTPase structure, their specific feature is the inability to hydrolyse GTP-bound nucleotide. This aspect makes them atypical among Rho GTPases. Rnds are regulated for their expression at the transcriptional or post-transcriptional levels and they are activated through post-translational modifications and interactions with other proteins. Rnd proteins are mainly involved in the regulation of the actin cytoskeleton and cell proliferation. Whereas Rnd3 is ubiquitously expressed, Rnd1 and 2 are tissue-specific. Increasing data has described their important role during development and diseases. Herein, we describe their involvement in physiological and pathological conditions with a focus on the neuronal and vascular systems, and summarize their implications in tumorigenesis.
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Affiliation(s)
- Sara Basbous
- INSERM, BaRITOn, U1053, F-33000, Univ. Bordeaux, Bordeaux, France
| | - Roberta Azzarelli
- Department of Biology, Unit of Cell and Developmental Biology, University of Pisa, Pisa, Italy
| | - Emilie Pacary
- INSERM, U1215 - Neurocentre Magendie, F-33077, Univ. Bordeaux, Bordeaux, France
| | - Violaine Moreau
- INSERM, BaRITOn, U1053, F-33000, Univ. Bordeaux, Bordeaux, France
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10
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Kuhlmann N, Milnerwood AJ. A Critical LRRK at the Synapse? The Neurobiological Function and Pathophysiological Dysfunction of LRRK2. Front Mol Neurosci 2020; 13:153. [PMID: 32973447 PMCID: PMC7482583 DOI: 10.3389/fnmol.2020.00153] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 07/22/2020] [Indexed: 12/25/2022] Open
Abstract
Since the discovery of LRRK2 mutations causal to Parkinson's disease (PD) in the early 2000s, the LRRK2 protein has been implicated in a plethora of cellular processes in which pathogenesis could occur, yet its physiological function remains elusive. The development of genetic models of LRRK2 PD has helped identify the etiological and pathophysiological underpinnings of the disease, and may identify early points of intervention. An important role for LRRK2 in synaptic function has emerged in recent years, which links LRRK2 to other genetic forms of PD, most notably those caused by mutations in the synaptic protein α-synuclein. This point of convergence may provide useful clues as to what drives dysfunction in the basal ganglia circuitry and eventual death of substantia nigra (SN) neurons. Here, we discuss the evolution and current state of the literature placing LRRK2 at the synapse, through the lens of knock-out, overexpression, and knock-in animal models. We hope that a deeper understanding of LRRK2 neurobiology, at the synapse and beyond, will aid the eventual development of neuroprotective interventions for PD, and the advancement of useful treatments in the interim.
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Affiliation(s)
- Naila Kuhlmann
- Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.,Department of Neurology & Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Austen J Milnerwood
- Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.,Department of Neurology & Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
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11
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Matsuda T, Oinuma I. Imaging endogenous synaptic proteins in primary neurons at single-cell resolution using CRISPR/Cas9. Mol Biol Cell 2019; 30:2838-2855. [PMID: 31509485 PMCID: PMC6789158 DOI: 10.1091/mbc.e19-04-0223] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Fluorescence imaging at single-cell resolution is a crucial approach to analyzing the spatiotemporal regulation of proteins within individual cells of complex neural networks. Here we present a nonviral strategy that enables the tagging of endogenous loci by CRISPR/Cas9-mediated genome editing combined with a nucleofection technique. The method allowed expression of fluorescently tagged proteins at endogenous levels, and we successfully achieved tagging of a presynaptic protein, synaptophysin (Syp), and a postsynaptic protein, PSD-95, in cultured postmitotic neurons. Superresolution fluorescence microscopy of fixed neurons confirmed the identical localization patterns of the tagged proteins to those of endogenous ones verified by immunohistochemistry. The system is also applicable for multiplexed labeling and live-cell imaging. Live imaging with total internal reflection fluorescence microscopy of a single dendritic process of a neuron double-labeled with Syp-mCherry and PSD-95-EGFP revealed the previously undescribed dynamic localization of the proteins synchronously moving along dendritic shafts. Our convenient and versatile strategy is potent for analysis of proteins whose ectopic expressions perturb cellular functions.
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Affiliation(s)
- Takahiko Matsuda
- Laboratory of Cell and Molecular Biology, Graduate School of Life Science, University of Hyogo, Hyogo 678-1297, Japan
| | - Izumi Oinuma
- Laboratory of Cell and Molecular Biology, Graduate School of Life Science, University of Hyogo, Hyogo 678-1297, Japan.,Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto 606-8501, Japan
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12
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Mouly L, Gilhodes J, Lemarié A, Cohen-Jonathan Moyal E, Toulas C, Favre G, Sordet O, Monferran S. The RND1 Small GTPase: Main Functions and Emerging Role in Oncogenesis. Int J Mol Sci 2019; 20:ijms20153612. [PMID: 31344837 PMCID: PMC6696182 DOI: 10.3390/ijms20153612] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 07/10/2019] [Accepted: 07/21/2019] [Indexed: 02/07/2023] Open
Abstract
The Rho GTPase family can be classified into classic and atypical members. Classic members cycle between an inactive Guanosine DiPhosphate -bound state and an active Guanosine TriPhosphate-bound state. Atypical Rho GTPases, such as RND1, are predominantly in an active GTP-bound conformation. The role of classic members in oncogenesis has been the subject of numerous studies, while that of atypical members has been less explored. Besides the roles of RND1 in healthy tissues, recent data suggest that RND1 is involved in oncogenesis and response to cancer therapeutics. Here, we present the current knowledge on RND1 expression, subcellular localization, and functions in healthy tissues. Then, we review data showing that RND1 expression is dysregulated in tumors, the molecular mechanisms involved in this deregulation, and the role of RND1 in oncogenesis. For several aggressive tumors, RND1 presents the features of a tumor suppressor gene. In these tumors, low expression of RND1 is associated with a bad prognosis for the patients. Finally, we highlight that RND1 expression is induced by anticancer agents and modulates their response. Of note, RND1 mRNA levels in tumors could be used as a predictive marker of both patient prognosis and response to anticancer agents.
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Affiliation(s)
- Laetitia Mouly
- Cancer Research Center of Toulouse, INSERM UMR1037, 31037 Toulouse, France
- Faculty of Pharmacy and Medecine, Université Toulouse III, 31062 Toulouse, France
| | - Julia Gilhodes
- Institut Claudius Regaud, IUCT-O, 31059 Toulouse, France
| | - Anthony Lemarié
- Cancer Research Center of Toulouse, INSERM UMR1037, 31037 Toulouse, France
- Faculty of Pharmacy and Medecine, Université Toulouse III, 31062 Toulouse, France
| | - Elizabeth Cohen-Jonathan Moyal
- Cancer Research Center of Toulouse, INSERM UMR1037, 31037 Toulouse, France
- Faculty of Pharmacy and Medecine, Université Toulouse III, 31062 Toulouse, France
- Institut Claudius Regaud, IUCT-O, 31059 Toulouse, France
| | - Christine Toulas
- Cancer Research Center of Toulouse, INSERM UMR1037, 31037 Toulouse, France
- Institut Claudius Regaud, IUCT-O, 31059 Toulouse, France
| | - Gilles Favre
- Cancer Research Center of Toulouse, INSERM UMR1037, 31037 Toulouse, France
- Faculty of Pharmacy and Medecine, Université Toulouse III, 31062 Toulouse, France
- Institut Claudius Regaud, IUCT-O, 31059 Toulouse, France
| | - Olivier Sordet
- Cancer Research Center of Toulouse, INSERM UMR1037, 31037 Toulouse, France
| | - Sylvie Monferran
- Cancer Research Center of Toulouse, INSERM UMR1037, 31037 Toulouse, France.
- Faculty of Pharmacy and Medecine, Université Toulouse III, 31062 Toulouse, France.
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13
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Rho GTPases in the Physiology and Pathophysiology of Peripheral Sensory Neurons. Cells 2019; 8:cells8060591. [PMID: 31208035 PMCID: PMC6627758 DOI: 10.3390/cells8060591] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 06/10/2019] [Accepted: 06/11/2019] [Indexed: 12/13/2022] Open
Abstract
Numerous experimental studies demonstrate that the Ras homolog family of guanosine triphosphate hydrolases (Rho GTPases) Ras homolog family member A (RhoA), Ras-related C3 botulinum toxin substrate 1 (Rac1) and cell division cycle 42 (Cdc42) are important regulators in somatosensory neurons, where they elicit changes in the cellular cytoskeleton and are involved in diverse biological processes during development, differentiation, survival and regeneration. This review summarizes the status of research regarding the expression and the role of the Rho GTPases in peripheral sensory neurons and how these small proteins are involved in development and outgrowth of sensory neurons, as well as in neuronal regeneration after injury, inflammation and pain perception. In sensory neurons, Rho GTPases are activated by various extracellular signals through membrane receptors and elicit their action through a wide range of downstream effectors, such as Rho-associated protein kinase (ROCK), phosphoinositide 3-kinase (PI3K) or mixed-lineage kinase (MLK). While RhoA is implicated in the assembly of stress fibres and focal adhesions and inhibits neuronal outgrowth through growth cone collapse, Rac1 and Cdc42 promote neuronal development, differentiation and neuroregeneration. The functions of Rho GTPases are critically important in the peripheral somatosensory system; however, their signalling interconnections and partially antagonistic actions are not yet fully understood.
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14
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Chidambaram SB, Rathipriya AG, Bolla SR, Bhat A, Ray B, Mahalakshmi AM, Manivasagam T, Thenmozhi AJ, Essa MM, Guillemin GJ, Chandra R, Sakharkar MK. Dendritic spines: Revisiting the physiological role. Prog Neuropsychopharmacol Biol Psychiatry 2019; 92:161-193. [PMID: 30654089 DOI: 10.1016/j.pnpbp.2019.01.005] [Citation(s) in RCA: 150] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Revised: 01/04/2019] [Accepted: 01/12/2019] [Indexed: 12/11/2022]
Abstract
Dendritic spines are small, thin, specialized protrusions from neuronal dendrites, primarily localized in the excitatory synapses. Sophisticated imaging techniques revealed that dendritic spines are complex structures consisting of a dense network of cytoskeletal, transmembrane and scaffolding molecules, and numerous surface receptors. Molecular signaling pathways, mainly Rho and Ras family small GTPases pathways that converge on actin cytoskeleton, regulate the spine morphology and dynamics bi-directionally during synaptic activity. During synaptic plasticity the number and shapes of dendritic spines undergo radical reorganizations. Long-term potentiation (LTP) induction promote spine head enlargement and the formation and stabilization of new spines. Long-term depression (LTD) results in their shrinkage and retraction. Reports indicate increased spine density in the pyramidal neurons of autism and Fragile X syndrome patients and reduced density in the temporal gyrus loci of schizophrenic patients. Post-mortem reports of Alzheimer's brains showed reduced spine number in the hippocampus and cortex. This review highlights the spine morphogenesis process, the activity-dependent structural plasticity and mechanisms by which synaptic activity sculpts the dendritic spines, the structural and functional changes in spines during learning and memory using LTP and LTD processes. It also discusses on spine status in neurodegenerative diseases and the impact of nootropics and neuroprotective agents on the functional restoration of dendritic spines.
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Affiliation(s)
- Saravana Babu Chidambaram
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research (JSSAHER), Mysuru, Karnataka 570015, India.
| | - A G Rathipriya
- Food and Brain Research Foundation, Chennai, Tamil Nadu, India
| | - Srinivasa Rao Bolla
- Department of Anatomy, College of Medicine, Imam Abdulrahman Bin Faisal University, Damam, Saudi Arabia
| | - Abid Bhat
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research (JSSAHER), Mysuru, Karnataka 570015, India
| | - Bipul Ray
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research (JSSAHER), Mysuru, Karnataka 570015, India
| | - Arehally Marappa Mahalakshmi
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research (JSSAHER), Mysuru, Karnataka 570015, India
| | - Thamilarasan Manivasagam
- Department of Biochemistry and Biotechnology, Faculty of Science, Annamalai University, Annamalainagar, Tamilnadu, India
| | - Arokiasamy Justin Thenmozhi
- Department of Biochemistry and Biotechnology, Faculty of Science, Annamalai University, Annamalainagar, Tamilnadu, India
| | - Musthafa Mohamed Essa
- Department of Food Science and Nutrition, CAMS, Sultan Qaboos University, Muscat, Oman
| | - Gilles J Guillemin
- Neuropharmacology Group, Faculty of Medicine and Health Sciences, Deb Bailey MND Research Laboratory, Macquarie University, Sydney, NSW 2109, Australia
| | - Ramesh Chandra
- Department of Chemistry, Ambedkar Centre for BioMedical Research, Delhi University, Delhi 110007, India
| | - Meena Kishore Sakharkar
- College of Pharmacy and Nutrition, University of Saskatchewan, 107, Wiggins Road, Saskatoon, SK S7N 5C9, Canada.
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15
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Mouly L, Mamouni K, Gence R, Cristini A, Cherier J, Castinel A, Legrand M, Favre G, Sordet O, Monferran S. PARP-1-dependent RND1 transcription induced by topoisomerase I cleavage complexes confers cellular resistance to camptothecin. Cell Death Dis 2018; 9:931. [PMID: 30209297 PMCID: PMC6135836 DOI: 10.1038/s41419-018-0981-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 08/02/2018] [Accepted: 08/20/2018] [Indexed: 02/02/2023]
Abstract
RHO GTPases regulate essential functions such as the organization of the actin cytoskeleton. The classic members cycle between an active GTP-bound and an inactive GDP-bound conformation whereas atypical members are predominantly GTP-bound. Besides their well-established role, the classic RHO GTPases RHOB and RAC1, are rapidly induced and/or activated by genotoxic stress and contribute to the DNA damage response. Here we used camptothecin, a selective topoisomerase I (TOP1) inhibitor that stabilizes TOP1 cleavage complexes (TOP1cc), to search for other potential early DNA damage-inducible RHO GTPase genes. We identified that an atypical RHO GTPase, RND1, is rapidly induced by camptothecin. RND1 induction is closely associated with the presence of TOP1cc induced by camptothecin or by DNA lesions that elevate TOP1cc levels such as UV and hydrogen peroxide. We further demonstrated that camptothecin increases RND1 gene transcription and mRNA stability. Camptothecin also increases poly(ADP-ribose) polymerase 1 (PARP-1) activity, whose inhibition reduces RND1 transcription. In addition, overexpression of RND1 increases PARP-1, suggesting a cross-talk between PARP-1 and RND1. Finally, RND1 protects cells against camptothecin-induced apoptosis, and hence favors cellular resistance to camptothecin. Together, these findings highlight RND1 as an atypical RHO GTPase early induced by TOP1cc, and show that the TOP1cc-PARP-1-RND1 pathway protects cells against apoptosis induced by camptothecin.
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Affiliation(s)
- Laetitia Mouly
- Cancer Research Center of Toulouse (CRCT), INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, Toulouse, France.,Faculté des Sciences Pharmaceutiques, Université de Toulouse, Université Toulouse III Paul Sabatier, Toulouse, France
| | - Kenza Mamouni
- Cancer Research Center of Toulouse (CRCT), INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, Toulouse, France.,Faculté des Sciences Pharmaceutiques, Université de Toulouse, Université Toulouse III Paul Sabatier, Toulouse, France
| | - Remi Gence
- Cancer Research Center of Toulouse (CRCT), INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, Toulouse, France.,Faculté des Sciences Pharmaceutiques, Université de Toulouse, Université Toulouse III Paul Sabatier, Toulouse, France
| | - Agnese Cristini
- Cancer Research Center of Toulouse (CRCT), INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, Toulouse, France.,Faculté des Sciences Pharmaceutiques, Université de Toulouse, Université Toulouse III Paul Sabatier, Toulouse, France
| | - Julia Cherier
- Cancer Research Center of Toulouse (CRCT), INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, Toulouse, France
| | - Adrien Castinel
- Faculté des Sciences Pharmaceutiques, Université de Toulouse, Université Toulouse III Paul Sabatier, Toulouse, France
| | - Morgane Legrand
- Faculté des Sciences Pharmaceutiques, Université de Toulouse, Université Toulouse III Paul Sabatier, Toulouse, France
| | - Gilles Favre
- Cancer Research Center of Toulouse (CRCT), INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, Toulouse, France.,Faculté des Sciences Pharmaceutiques, Université de Toulouse, Université Toulouse III Paul Sabatier, Toulouse, France
| | - Olivier Sordet
- Cancer Research Center of Toulouse (CRCT), INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, Toulouse, France.
| | - Sylvie Monferran
- Cancer Research Center of Toulouse (CRCT), INSERM, Université de Toulouse, Université Toulouse III Paul Sabatier, CNRS, Toulouse, France. .,Faculté des Sciences Pharmaceutiques, Université de Toulouse, Université Toulouse III Paul Sabatier, Toulouse, France.
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16
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Guo W, Shang DM, Cao JH, Feng K, He YC, Jiang Y, Wang S, Gao YF. Identifying and Analyzing Novel Epilepsy-Related Genes Using Random Walk with Restart Algorithm. BIOMED RESEARCH INTERNATIONAL 2017; 2017:6132436. [PMID: 28255556 PMCID: PMC5309434 DOI: 10.1155/2017/6132436] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Accepted: 01/15/2017] [Indexed: 02/07/2023]
Abstract
As a pathological condition, epilepsy is caused by abnormal neuronal discharge in brain which will temporarily disrupt the cerebral functions. Epilepsy is a chronic disease which occurs in all ages and would seriously affect patients' personal lives. Thus, it is highly required to develop effective medicines or instruments to treat the disease. Identifying epilepsy-related genes is essential in order to understand and treat the disease because the corresponding proteins encoded by the epilepsy-related genes are candidates of the potential drug targets. In this study, a pioneering computational workflow was proposed to predict novel epilepsy-related genes using the random walk with restart (RWR) algorithm. As reported in the literature RWR algorithm often produces a number of false positive genes, and in this study a permutation test and functional association tests were implemented to filter the genes identified by RWR algorithm, which greatly reduce the number of suspected genes and result in only thirty-three novel epilepsy genes. Finally, these novel genes were analyzed based upon some recently published literatures. Our findings implicate that all novel genes were closely related to epilepsy. It is believed that the proposed workflow can also be applied to identify genes related to other diseases and deepen our understanding of the mechanisms of these diseases.
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Affiliation(s)
- Wei Guo
- Department of Outpatient, China-Japan Union Hospital of Jilin University, Changchun 130033, China
| | - Dong-Mei Shang
- Department of Outpatient, China-Japan Union Hospital of Jilin University, Changchun 130033, China
| | - Jing-Hui Cao
- Department of Neurosurgery, China-Japan Union Hospital of Jilin University, Changchun 130033, China
| | - Kaiyan Feng
- Department of Computer Science, Guangdong AIB Polytechnic, Guangzhou 510507, China
| | - Yi-Chun He
- Department of Neurosurgery, China-Japan Union Hospital of Jilin University, Changchun 130033, China
| | - Yang Jiang
- Department of Surgery, China-Japan Union Hospital of Jilin University, Changchun 130033, China
| | - ShaoPeng Wang
- School of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Yu-Fei Gao
- Department of Neurosurgery, China-Japan Union Hospital of Jilin University, Changchun 130033, China
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17
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Li L, Liu H, Dong P, Li D, Legant WR, Grimm JB, Lavis LD, Betzig E, Tjian R, Liu Z. Real-time imaging of Huntingtin aggregates diverting target search and gene transcription. eLife 2016; 5. [PMID: 27484239 PMCID: PMC4972539 DOI: 10.7554/elife.17056] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 07/07/2016] [Indexed: 01/21/2023] Open
Abstract
The presumptive altered dynamics of transient molecular interactions in vivo contributing to neurodegenerative diseases have remained elusive. Here, using single-molecule localization microscopy, we show that disease-inducing Huntingtin (mHtt) protein fragments display three distinct dynamic states in living cells - 1) fast diffusion, 2) dynamic clustering and 3) stable aggregation. Large, stable aggregates of mHtt exclude chromatin and form 'sticky' decoy traps that impede target search processes of key regulators involved in neurological disorders. Functional domain mapping based on super-resolution imaging reveals an unexpected role of aromatic amino acids in promoting protein-mHtt aggregate interactions. Genome-wide expression analysis and numerical simulation experiments suggest mHtt aggregates reduce transcription factor target site sampling frequency and impair critical gene expression programs in striatal neurons. Together, our results provide insights into how mHtt dynamically forms aggregates and disrupts the finely-balanced gene control mechanisms in neuronal cells.
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Affiliation(s)
- Li Li
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States.,LKS Bio-medical and Health Sciences Center, CIRM Center of Excellence, University of California, Berkeley, United States
| | - Hui Liu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Peng Dong
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Dong Li
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Wesley R Legant
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Jonathan B Grimm
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Luke D Lavis
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States.,Transcription Imaging Consortium, Howard Hughes Medical Institute, Ashburn, United States
| | - Eric Betzig
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Robert Tjian
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States.,LKS Bio-medical and Health Sciences Center, CIRM Center of Excellence, University of California, Berkeley, United States.,Transcription Imaging Consortium, Howard Hughes Medical Institute, Ashburn, United States
| | - Zhe Liu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States.,Transcription Imaging Consortium, Howard Hughes Medical Institute, Ashburn, United States
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18
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Plexin-B3 suppresses excitatory and promotes inhibitory synapse formation in rat hippocampal neurons. Exp Cell Res 2015; 335:269-78. [PMID: 25989221 DOI: 10.1016/j.yexcr.2015.05.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Revised: 04/23/2015] [Accepted: 05/10/2015] [Indexed: 11/21/2022]
Abstract
Molecular mechanisms underlying synaptogenesis and synaptic plasticity have become one of the main topics in neurobiology. Increasing evidence suggests that axon guidance molecules including semaphorins and plexins participate in synapse formation and elimination. Although class B plexins are widely expressed in the brain, their role in the nervous system remains poorly characterized. We previously identified that B-plexins modulate microtubule dynamics and through this impact dendrite growth in rat hippocampal neurons. Here, we demonstrate that Plexin-B2 and Plexin-B3 are present in dendrites, but do not localize in synapses. We find that overexpression of all B-plexins leads to decreased volume of excitatory synapses, and at the same time Plexin-B1 and Plexin-B3 promote inhibitory synapse assembly. Plexin-B3 mutants revealed that these processes use different downstream pathways. While elimination of excitatory synapses is the result of Plexin-B3 binding to microtubule end binding proteins EB1 and EB3, the increase in inhibitory synapses is mediated by regulation of Ras and Rho GTPases. Overall, our findings demonstrate that Plexin-B3 contributes to regulating synapse formation.
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19
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Takeuchi S, Katoh H, Negishi M. Eph/ephrin reverse signalling induces axonal retraction through RhoA/ROCK pathway. J Biochem 2015; 158:245-52. [PMID: 25922200 DOI: 10.1093/jb/mvv042] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 03/26/2015] [Indexed: 01/09/2023] Open
Abstract
Eph/ephrin signalling plays essential roles in various tissue developments, such as axon guidance, angiogenesis and tissue separation. Interaction between Ephs and ephrins upon cell-cell contact results in forward (towards Eph-expressing cells) and reverse (towards ephrin-expressing cells) signalling. Although the molecular mechanisms downstream of Eph/ephrin forward signalling have been extensively studied, the functions and intracellular molecular mechanisms of Eph/ephrin reverse signalling are not fully understood. Rho GTPases are key regulators of the actin cytoskeleton to regulate cell morphology. In this study, we revealed that stimulation with the extracellular domain of EphB2 to activate Eph/ephrin reverse signalling induced axonal retraction in hippocampal neurons. The reduction of axonal length and branching by Eph/ephrin reverse signalling was blocked by inhibition of RhoA or Rho-associated coiled-coil-containing protein kinase (ROCK). These results suggest that Eph/ephrin reverse signalling negatively regulates axonal outgrowth and branching through RhoA/ROCK pathway in hippocampal neurons.
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Affiliation(s)
- Shingo Takeuchi
- Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Yoshidakonoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Hironori Katoh
- Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Yoshidakonoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Manabu Negishi
- Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Yoshidakonoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
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20
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Azzarelli R, Kerloch T, Pacary E. Regulation of cerebral cortex development by Rho GTPases: insights from in vivo studies. Front Cell Neurosci 2015; 8:445. [PMID: 25610373 PMCID: PMC4285737 DOI: 10.3389/fncel.2014.00445] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 12/11/2014] [Indexed: 12/31/2022] Open
Abstract
The cerebral cortex is the site of higher human cognitive and motor functions. Histologically, it is organized into six horizontal layers, each containing unique populations of molecularly and functionally distinct excitatory projection neurons and inhibitory interneurons. The stereotyped cellular distribution of cortical neurons is crucial for the formation of functional neural circuits and it is predominantly established during embryonic development. Cortical neuron development is a multiphasic process characterized by sequential steps of neural progenitor proliferation, cell cycle exit, neuroblast migration and neuronal differentiation. This series of events requires an extensive and dynamic remodeling of the cell cytoskeleton at each step of the process. As major regulators of the cytoskeleton, the family of small Rho GTPases has been shown to play essential functions in cerebral cortex development. Here we review in vivo findings that support the contribution of Rho GTPases to cortical projection neuron development and we address their involvement in the etiology of cerebral cortex malformations.
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Affiliation(s)
- Roberta Azzarelli
- Department of Oncology, Hutchison/MRC Research Centre, Cambridge Biomedical Campus, University of Cambridge Cambridge, UK
| | - Thomas Kerloch
- Institut National de la Santé et de la Recherche Médicale U862, Neurocentre Magendie Bordeaux, France ; Institut National de la Santé et de la Recherche Médicale, Physiopathologie de la Plasticité Neuronale, Université de Bordeaux Bordeaux, France
| | - Emilie Pacary
- Institut National de la Santé et de la Recherche Médicale U862, Neurocentre Magendie Bordeaux, France ; Institut National de la Santé et de la Recherche Médicale, Physiopathologie de la Plasticité Neuronale, Université de Bordeaux Bordeaux, France
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21
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Cao S, Buck M. Optimization and stabilization of Rho small GTPase proteins for solution NMR studies: The case of Rnd1. Small GTPases 2014; 2:295-304. [PMID: 22545226 PMCID: PMC3337157 DOI: 10.4161/sgtp.19257] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Rho GTPases of the Ras superfamily have important roles in regulating the organization of the actin filament system, morphogenesis and migration of cells. Structural details for these proteins are still emerging, and information on their dynamics in solution is much needed to understand the mechanisms underlying their signaling functions. This report reviews conditions for solution NMR studies of Rho GTPases and describes our optimization and stabilization of Rnd1 for such experiments. Rnd1 belongs to the Rnd protein subfamily branch of Rho small GTPases and functions in neurite outgrowth, dendrite development and in axon guidance. However, as we report here, solution NMR studies of this protein are challenging. Multiple methods have been employed to enhance the stability of Rnd1, including by cleavage of an N-terminal His expression tag and by addition of non-hydrolysable GMPPNP (β: γ-imidoguanosine 5'-triphosphate) nucleotide. Further stabilization of Rnd1 against aggregation was achieved through a structure informed point mutation while maintaining its conformation and binding affinity for a partner protein. The NMR spectrum of the optimized protein reveals significant improvement in NMR signal dispersion and intensity. This work paves the way for structural and protein-protein/protein-ligand interaction studies of Rnd1 by solution NMR and also provides a guide for optimization and stabilization of other Rho GTPases.
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22
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Roet KCD, Verhaagen J. Understanding the neural repair-promoting properties of olfactory ensheathing cells. Exp Neurol 2014; 261:594-609. [PMID: 24842489 DOI: 10.1016/j.expneurol.2014.05.007] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 05/02/2014] [Accepted: 05/06/2014] [Indexed: 12/13/2022]
Abstract
Olfactory ensheathing glial cells (OECs) are a specialized type of glia that form a continuously aligned cellular pathway that actively supports unprecedented regeneration of primary olfactory axons from the periphery into the central nervous system. Implantation of OECs stimulates neural repair in experimental models of spinal cord, brain and peripheral nerve injury and delays disease progression in animal models for neurodegenerative diseases like amyotrophic lateral sclerosis. OECs implanted in the injured spinal cord display a plethora of pro-regenerative effects; they promote axonal regeneration, reorganize the glial scar, remyelinate axons, stimulate blood vessel formation, have phagocytic properties and modulate the immune response. Recently genome wide transcriptional profiling and proteomics analysis combined with classical or larger scale "medium-throughput" bioassays have provided novel insights into the molecular mechanism that endow OECs with their pro-regenerative properties. Here we review these studies and show that the gaps that existed in our understanding of the molecular basis of the reparative properties of OECs are narrowing. OECs express functionally connected sets of genes that can be linked to at least 10 distinct processes directly relevant to neural repair. The data indicate that OECs exhibit a range of synergistic cellular activities, including active and passive stimulation of axon regeneration (by secretion of growth factors, axon guidance molecules and basement membrane components) and critical aspects of tissue repair (by structural remodeling and support, modulation of the immune system, enhancement of neurotrophic and antigenic stimuli and by metabolizing toxic macromolecules). Future experimentation will have to further explore the newly acquired knowledge to enhance the therapeutic potential of OECs.
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Affiliation(s)
- Kasper C D Roet
- Department of Neuroregeneration, Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105BA Amsterdam, The Netherlands.
| | - Joost Verhaagen
- Department of Neuroregeneration, Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105BA Amsterdam, The Netherlands; Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University, Boelelaan 1085, Amsterdam 1081HV, The Netherlands.
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STI1 antagonizes cytoskeleton collapse mediated by small GTPase Rnd1 and regulates neurite growth. Exp Cell Res 2014; 324:84-91. [PMID: 24690281 DOI: 10.1016/j.yexcr.2014.03.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 03/19/2014] [Accepted: 03/22/2014] [Indexed: 01/10/2023]
Abstract
Rnd proteins comprise a branch of the Rho family of small GTP-binding proteins, which have been implicated in rearrangements of the actin cytoskeleton and microtubule dynamics. Particularly in the nervous system, Rnd family proteins regulate neurite formation, dendrite development and axonal branching. A secreted form of the co-chaperone Stress-Inducible Protein 1 (STI1) has been described as a prion protein partner that is involved in several processes of the nervous system, such as neurite outgrowth, neuroprotection, astrocyte development, and the self-renewal of neural progenitor cells. We show that cytoplasmic STI1 directly interacts with the GTPase Rnd1. This interaction is specific for the Rnd1 member of the Rnd family. In the COS collapse assay, overexpression of STI1 prevents Rnd1-plexin-A1-mediated cytoskeleton retraction. In PC-12 cells, overexpression of STI1 enhances neurite outgrowth in cellular processes initially established by Rnd1. Therefore, we propose that STI1 participates in Rnd1-induced signal transduction pathways that are involved in the dynamics of the actin cytoskeleton.
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Sala C, Segal M. Dendritic spines: the locus of structural and functional plasticity. Physiol Rev 2014; 94:141-88. [PMID: 24382885 DOI: 10.1152/physrev.00012.2013] [Citation(s) in RCA: 336] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The introduction of high-resolution time lapse imaging and molecular biological tools has changed dramatically the rate of progress towards the understanding of the complex structure-function relations in synapses of central spiny neurons. Standing issues, including the sequence of molecular and structural processes leading to formation, morphological change, and longevity of dendritic spines, as well as the functions of dendritic spines in neurological/psychiatric diseases are being addressed in a growing number of recent studies. There are still unsettled issues with respect to spine formation and plasticity: Are spines formed first, followed by synapse formation, or are synapses formed first, followed by emergence of a spine? What are the immediate and long-lasting changes in spine properties following exposure to plasticity-producing stimulation? Is spine volume/shape indicative of its function? These and other issues are addressed in this review, which highlights the complexity of molecular pathways involved in regulation of spine structure and function, and which contributes to the understanding of central synaptic interactions in health and disease.
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Cao S, Mao X, Liu D, Buck M. Backbone assignment and secondary structure of Rnd1, an unusual Rho family small GTPase. BIOMOLECULAR NMR ASSIGNMENTS 2013; 7:121-128. [PMID: 22618864 DOI: 10.1007/s12104-012-9391-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Accepted: 05/03/2012] [Indexed: 06/01/2023]
Abstract
Rho GTPases have attracted considerable interest as signaling molecules due to their variety of functional roles in cells. Rnd1 is a relatively recently discovered Rho GTPase with no enzymatic activity against its bound GTP nucleotide, setting it apart from other family members. Research has revealed a critical role for Rnd1 not only in neurite outgrowth, dendrite development, axon guidance, but also in gastric cancer and in endothelial cells during inflammation. Structural information is crucial for understanding the mechanism that forms the basis for protein-protein interactions and functions, but until recently there were no reports of NMR studies directly on the Rnd1 protein. In this paper we report assignments for the majority of Rnd1 NMR resonances based on 2D and 3D NMR spectra. Rnd1 assignment was a challenging task, however, despite optimization strategies that have facilitated NMR studies of the protein (Cao and Buck in Small GTPase 2:295-304, 2012). Besides common triple-resonance experiments, 3D HNCA, 3D HN(CO)CA, 3D HNCO which are usually employed for sequence assignment, 3D NOESY experiments and specific labeling of 13 kinds of amino acids were also utilized to gain as many (1)H(N), (13)C, and (15)N resonances assignments as possible. For 170 cross peaks observed out of 183 possible mainchain N-H correlations in the (1)H-(15)N TROSY spectrum, backbone assignment was finally completed for 127 resonances. The secondary structure was then defined by chemical shifts and TALOS+ based on the assignments. The overall structure in solution compares well with that of Rnd1 in a crystal, except for two short segments, residues 77-83 and residues 127-131. Given that some features are shared among Rho GTPases, Rnd1 assignments are also compared with two other family members, Cdc42 and Rac1. The overall level of Rnd1 assignment is lower than for Cdc42 and Rac1, consistent with its lower stability and possibly increased internal dynamics. However, while the Rnd1 switch II region remained un-assigned, the switch I region could be more fully assigned compared to Cdc42 and Rac1. The NMR assignment and structure analysis reported here provides a robust basis for future study of the binding between Rnd1 and other proteins, as well as for further studies of the molecular function of this unusual GTPase.
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Affiliation(s)
- Shufen Cao
- College of Life Science, Central China Normal University, 152 Luoyu Road, Wuhan 430079, Hubei, China.
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26
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Expression analysis of Lrrk1, Lrrk2 and Lrrk2 splice variants in mice. PLoS One 2013; 8:e63778. [PMID: 23675505 PMCID: PMC3651128 DOI: 10.1371/journal.pone.0063778] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 04/05/2013] [Indexed: 11/19/2022] Open
Abstract
Missense mutations in the leucine-rich repeat kinase 2 gene (LRRK2) are linked to autosomal dominant forms of Parkinson's disease (PD). In order to get insights into the physiological role of Lrrk2, we examined the distribution of Lrrk2 mRNA and different splice variants in the developing murine embryo and the adult brain of Mus musculus. To analyse if the Lrrk2-paralog, Lrrk1, may have redundant functions in PD-development, we also compared Lrrk1 and Lrrk2 expression in the same tissues. Using radioactive in situ hybridization, we found ubiquitous expression of both genes at low level from embryonic stage E9.5 onward, which progressively increased up until birth. The developing central nervous system (CNS) displayed no prominent Lrrk2 mRNA signals at these time-points. However, in the entire postnatal brain Lrrk2 became detectable, showing strongest level in the striatum and the cortex of adult mice; Lrrk1 was only detectable in the mitral cell layer of the olfactory bulb. Thus, due to the non-overlapping expression patterns, a redundant function of Lrrk2 and Lrrk1 in the pathogenesis of PD seems to be unlikely. Quantification of Lrrk2 mRNA and protein level in several brain regions by real-time PCR and Western blot verified the striatum and cortex as hotspots of postnatal Lrrk2 expression. Strong expression of Lrrk2 is mainly found in neurons, specifically in the dopamine receptor 1 (DRD1a) and 2 (DRD2)-positive subpopulations of the striatal medium spiny neurons. Finally, we identified 2 new splice-variants of Lrrk2 in RNA-samples from various adult brain regions and organs: a variant with a skipped exon 5 and a truncated variant terminating in an alternative exon 42a. In order to identify the origin of these two splice variants, we also analysed primary neural cultures independently and found cell-specific expression patterns for these variants in microglia and astrocytes.
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Hota PK, Buck M. Plexin structures are coming: opportunities for multilevel investigations of semaphorin guidance receptors, their cell signaling mechanisms, and functions. Cell Mol Life Sci 2012; 69:3765-805. [PMID: 22744749 PMCID: PMC11115013 DOI: 10.1007/s00018-012-1019-0] [Citation(s) in RCA: 125] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 04/09/2012] [Accepted: 04/11/2012] [Indexed: 01/13/2023]
Abstract
Plexin transmembrane receptors and their semaphorin ligands, as well as their co-receptors (Neuropilin, Integrin, VEGFR2, ErbB2, and Met kinase) are emerging as key regulatory proteins in a wide variety of developmental, regenerative, but also pathological processes. The diverse arenas of plexin function are surveyed, including roles in the nervous, cardiovascular, bone and skeletal, and immune systems. Such different settings require considerable specificity among the plexin and semaphorin family members which in turn are accompanied by a variety of cell signaling networks. Underlying the latter are the mechanistic details of the interactions and catalytic events at the molecular level. Very recently, dramatic progress has been made in solving the structures of plexins and of their complexes with associated proteins. This molecular level information is now suggesting detailed mechanisms for the function of both the extracellular as well as the intracellular plexin regions. Specifically, several groups have solved structures for extracellular domains for plexin-A2, -B1, and -C1, many in complex with semaphorin ligands. On the intracellular side, the role of small Rho GTPases has been of particular interest. These directly associate with plexin and stimulate a GTPase activating (GAP) function in the plexin catalytic domain to downregulate Ras GTPases. Structures for the Rho GTPase binding domains have been presented for several plexins, some with Rnd1 bound. The entire intracellular domain structure of plexin-A1, -A3, and -B1 have also been solved alone and in complex with Rac1. However, key aspects of the interplay between GTPases and plexins remain far from clear. The structural information is helping the plexin field to focus on key questions at the protein structural, cellular, as well as organism level that collaboratoria of investigations are likely to answer.
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Affiliation(s)
- Prasanta K. Hota
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106 USA
| | - Matthias Buck
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106 USA
- Department of Neuroscience, Case Western Reserve University School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106 USA
- Department of Pharmacology, Case Western Reserve University School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106 USA
- Comprehensive Cancer Center, Case Western Reserve University School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106 USA
- Center for Proteomics and Bioinformatics, Case Western Reserve University School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106 USA
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28
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Iwasawa N, Negishi M, Oinuma I. R-Ras controls axon branching through afadin in cortical neurons. Mol Biol Cell 2012; 23:2793-804. [PMID: 22593211 PMCID: PMC3395666 DOI: 10.1091/mbc.e12-02-0103] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Revised: 05/02/2012] [Accepted: 05/11/2012] [Indexed: 01/06/2023] Open
Abstract
Regulation of axon growth, guidance, and branching is essential for constructing a correct neuronal network. R-Ras, a Ras-family small GTPase, has essential roles in axon formation and guidance. During axon formation, R-Ras activates a series of phosphatidylinositol 3-kinase signaling, inducing activation of a microtubule-assembly promoter-collapsin response mediator protein-2. However, signaling molecules linking R-Ras to actin cytoskeleton-regulating axonal morphology remain obscure. Here we identify afadin, an actin-binding protein harboring Ras association (RA) domains, as an effector of R-Ras inducing axon branching through F-actin reorganization. We observe endogenous interaction of afadin with R-Ras in cortical neurons during the stage of axonal development. Ectopic expression of afadin increases axon branch number, and the RA domains and the carboxyl-terminal F-actin binding domain are required for this action. RNA interference knockdown experiments reveal that knockdown of endogenous afadin suppressed both basal and R-Ras-mediated axon branching in cultured cortical neurons. Subcellular localization analysis shows that active R-Ras-induced translocation of afadin and its RA domains is responsible for afadin localizing to the membrane and inducing neurite development in Neuro2a cells. Overall, our findings demonstrate a novel signaling pathway downstream of R-Ras that controls axon branching.
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Affiliation(s)
- Nariaki Iwasawa
- Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Manabu Negishi
- Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Izumi Oinuma
- Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
- Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan
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29
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Pozueta J, Lefort R, Shelanski ML. Synaptic changes in Alzheimer's disease and its models. Neuroscience 2012; 251:51-65. [PMID: 22687952 DOI: 10.1016/j.neuroscience.2012.05.050] [Citation(s) in RCA: 216] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 05/14/2012] [Accepted: 05/17/2012] [Indexed: 12/15/2022]
Abstract
Alzheimer's disease (AD) is a highly prevalent neurodegenerative disorder characterized by a progressive loss of cognition and the presence of two hallmark lesions, senile plaques (SP) and neurofibrillary tangles (NFT), which result from the accumulation and deposition of the β-amyloid peptide (Aβ) and the aggregation of hyperphosphorylated tau protein, respectively. Initially, it was thought that Aβ fibrils, which make up SP, were the root cause of the massive neurodegeneration usual found in AD brains. Over time, the longstanding emphasis on fibrillar Aβ deposits and neuronal death slowly gave way to a new paradigm involving soluble oligomeric forms of Aβ, which play a prominent role in triggering the cognitive deficits by specifically targeting synapses and disrupting synaptic signaling pathways. While this paradigm is widely accepted today in the AD field, the molecular details have not been fully elucidated. In this review, we address some of the important evidence, which has led to the Aβ oligomer-centric hypothesis as well as some of the key findings concerning the effects of Aβ oligomers on synapses at a morphological and functional level. Understanding how Aβ oligomers target synapses provides an important framework for ongoing AD research, which can lead to the development of successful therapeutic strategies designed to alter or perhaps reverse the course of the disease.
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Affiliation(s)
- J Pozueta
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain and Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, United States
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30
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Abstract
The Rif GTPase is a recent addition to small Rho GTPase family; it shares low homology with other members in the family and evolutionarily parallels with the development of vertebrates. Rif has the conserved Rho GTPase domain structures and cycles between a GDP-bound inactive form and a GTP-bound active form. In its active form, Rif signals through multiple downstream effectors. In the present review, our aim is to summarize the current information about the Rif effectors and how Rif remodels actin cytoskeleton in many aspects.
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31
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Peris B, Gonzalez-Granero S, Ballester-Lurbe B, García-Verdugo JM, Pérez-Roger I, Guerri C, Terrado J, Guasch RM. Neuronal polarization is impaired in mice lacking RhoE expression. J Neurochem 2012; 121:903-14. [DOI: 10.1111/j.1471-4159.2012.07733.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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32
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Oinuma I, Kawada K, Tsukagoshi K, Negishi M. Rnd1 and Rnd3 targeting to lipid raft is required for p190 RhoGAP activation. Mol Biol Cell 2012; 23:1593-604. [PMID: 22357615 PMCID: PMC3327318 DOI: 10.1091/mbc.e11-11-0900] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The N-terminal region is the lipid raft–targeting determinant. A novel regulatory mechanism is found by which Rnd proteins function as RhoA antagonists, as is a striking mechanism by which differential membrane targeting governs activities of G proteins having similarities in effector interaction. The Rnd proteins Rnd1, Rnd2, and Rnd3/RhoE are well known as key regulators of the actin cytoskeleton in various cell types, but they comprise a distinct subgroup of the Rho family in that they are GTP bound and constitutively active. Functional differences of the Rnd proteins in RhoA inhibition signaling have been reported in various cell types. Rnd1 and Rnd3 antagonize RhoA signaling by activating p190 RhoGAP, whereas Rnd2 does not. However, all the members of the Rnd family have been reported to bind directly to p190 RhoGAP and equally induce activation of p190 RhoGAP in vitro, and there is no evidence that accounts for the functional difference of the Rnd proteins in RhoA inhibition signaling. Here we report the role of the N-terminal region in signaling. Rnd1 and Rnd3, but not Rnd2, have a KERRA (Lys-Glu-Arg-Arg-Ala) sequence of amino acids in their N-terminus, which functions as the lipid raft-targeting determinant. The sequence mediates the lipid raft targeting of p190 RhoGAP correlated with its activation. Overall, our results demonstrate a novel regulatory mechanism by which differential membrane targeting governs activities of Rnd proteins to function as RhoA antagonists.
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Affiliation(s)
- Izumi Oinuma
- Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan.
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33
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Wakita Y, Kakimoto T, Katoh H, Negishi M. The F-BAR protein Rapostlin regulates dendritic spine formation in hippocampal neurons. J Biol Chem 2011; 286:32672-83. [PMID: 21768103 DOI: 10.1074/jbc.m111.236265] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pombe Cdc15 homology proteins, characterized by Fer/CIP4 homology Bin-Amphiphysin-Rvs/extended Fer/CIP4 homology (F-BAR/EFC) domains with membrane invaginating property, play critical roles in a variety of membrane reorganization processes. Among them, Rapostlin/formin-binding protein 17 (FBP17) has attracted increasing attention as a critical coordinator of endocytosis. Here we found that Rapostlin was expressed in the developing rat brain, including the hippocampus, in late developmental stages when accelerated dendritic spine formation and maturation occur. In primary cultured rat hippocampal neurons, knockdown of Rapostlin by shRNA or overexpression of Rapostlin-QQ, an F-BAR domain mutant of Rapostlin that has no ability to induce membrane invagination, led to a significant decrease in spine density. Expression of shRNA-resistant wild-type Rapostlin effectively restored spine density in Rapostlin knockdown neurons, whereas expression of Rapostlin deletion mutants lacking the protein kinase C-related kinase homology region 1 (HR1) or Src homology 3 (SH3) domain did not. In addition, knockdown of Rapostlin or overexpression of Rapostlin-QQ reduced the uptake of transferrin in hippocampal neurons. Knockdown of Rnd2, which binds to the HR1 domain of Rapostlin, also reduced spine density and the transferrin uptake. These results suggest that Rapostlin and Rnd2 cooperatively regulate spine density. Indeed, Rnd2 enhanced the Rapostlin-induced tubular membrane invagination. We conclude that the F-BAR protein Rapostlin, whose activity is regulated by Rnd2, plays a key role in spine formation through the regulation of membrane dynamics.
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Affiliation(s)
- Yohei Wakita
- Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
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34
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Tolias KF, Duman JG, Um K. Control of synapse development and plasticity by Rho GTPase regulatory proteins. Prog Neurobiol 2011; 94:133-48. [PMID: 21530608 DOI: 10.1016/j.pneurobio.2011.04.011] [Citation(s) in RCA: 197] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Revised: 04/13/2011] [Accepted: 04/15/2011] [Indexed: 12/21/2022]
Abstract
Synapses are specialized cell-cell contacts that mediate communication between neurons. Most excitatory synapses in the brain are housed on dendritic spines, small actin-rich protrusions extending from dendrites. During development and in response to environmental stimuli, spines undergo marked changes in shape and number thought to underlie processes like learning and memory. Improper spine development, in contrast, likely impedes information processing in the brain, since spine abnormalities are associated with numerous brain disorders. Elucidating the mechanisms that regulate the formation and plasticity of spines and their resident synapses is therefore crucial to our understanding of cognition and disease. Rho-family GTPases, key regulators of the actin cytoskeleton, play essential roles in orchestrating the development and remodeling of spines and synapses. Precise spatio-temporal regulation of Rho GTPase activity is critical for their function, since aberrant Rho GTPase signaling can cause spine and synapse defects as well as cognitive impairments. Rho GTPases are activated by guanine nucleotide exchange factors (GEFs) and inhibited by GTPase-activating proteins (GAPs). We propose that Rho-family GEFs and GAPs provide the spatiotemporal regulation and signaling specificity necessary for proper Rho GTPase function based on the following features they possess: (i) existence of multiple GEFs and GAPs per Rho GTPase, (ii) developmentally regulated expression, (iii) discrete localization, (iv) ability to bind to and organize specific signaling networks, and (v) tightly regulated activity, perhaps involving GEF/GAP interactions. Recent studies describe several Rho-family GEFs and GAPs that uniquely contribute to spinogenesis and synaptogenesis. Here, we highlight several of these proteins and discuss how they occupy distinct biochemical niches critical for synaptic development.
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Affiliation(s)
- Kimberley F Tolias
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA.
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35
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Riou P, Villalonga P, Ridley AJ. Rnd proteins: Multifunctional regulators of the cytoskeleton and cell cycle progression. Bioessays 2010; 32:986-92. [DOI: 10.1002/bies.201000060] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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36
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Miyata S, Mori Y, Tohyama M. PRMT3 is essential for dendritic spine maturation in rat hippocampal neurons. Brain Res 2010; 1352:11-20. [PMID: 20647003 DOI: 10.1016/j.brainres.2010.07.033] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2010] [Revised: 06/14/2010] [Accepted: 07/13/2010] [Indexed: 11/15/2022]
Abstract
Protein arginine N-methyltransferase 3 (PRMT3) is a cytoplasmic enzyme that utilizes S-adenosyl-L-methionine (AdoMet) to methylate specific proteins, most of which contain GAR (glycine-arginine rich) motifs. PRMT3 has been shown to play a role in the proper maturation of the 80S ribosome by binding to and catalyzing the methylation of rpS2, a component of the 40S ribosomal subunit. However, the other roles of PRMT3 are fairly unclear, particularly in the brain, which is abundant in methylated proteins. In this study, we perturbed PRMT3 expression in cultured rat hippocampal neurons by transiently introducing siRNA oligonucleotides that were designed to hybridize with PRMT3 mRNA and then we examined the morphological and functional effects of neuronal PRMT3 depletion. PRMT3-defective neurons showed deformed spines without any change in spine number; less BDNF-induced protein translation of alphaCaMKII; and diminished rpS2 protein stability. Furthermore, overexpression of a methylation-resistant rpS2, whose methylated arginine residues were deleted, produced phenotypes that were similar to those associated with PRMT3 downregulation. These findings demonstrated that PRMT3 possibly plays a pivotal role in neuronal translation by interaction with rpS2 and that it contributes to activity-dependent changes in the dendritic spines.
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Affiliation(s)
- Shingo Miyata
- Department of Anatomy and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.
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37
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Talens-Visconti R, Peris B, Guerri C, Guasch RM. RhoE stimulates neurite-like outgrowth in PC12 cells through inhibition of the RhoA/ROCK-I signalling. J Neurochem 2009; 112:1074-87. [PMID: 19968760 DOI: 10.1111/j.1471-4159.2009.06526.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Neurite formation involves coordinated changes between the actin cytoskeleton and the microtubule network. Rho GTPases are clearly implicated in several aspects of neuronal development and function. Indeed, RhoA is a negative regulator of neurite outgrowth and its effector Rho-kinase mediates the Rho-driven neurite retraction. Considering that RhoE/round protein (Rnd3) acts antagonistically to RhoA and it is also able to bind and inhibit rho kinase-I (p160ROCK) - ROCK-I, it is tempting to speculate a role of RhoE in neurite formation. We show for the first time that, in the absence of nerve growth factor (NGF), RhoE induces neurite-like outgrowth. Our results demonstrate that over-expression of RhoE decreases the activity of RhoA and reduces the expression of both ROCK-I and the phosphorylated myosin light chain phosphatase (MLCPp). Conversely, over-expression of either active RhoA or ROCK-I abolishes the RhoE-promoted neurite outgrowth, suggesting that RhoE induces neurite-like formation through inhibition of the RhoA/ROCK-I signalling. We also show that Rac and Cdc42 have a role in RhoE-induced neurite outgrowth. Finally, the present data further indicate that RhoE may be involved in the NGF-induced neurite outgrowth in PC12 cells, as depletion of RhoE by siRNA reduces the neurite formation induced by NGF. These findings provide new insights into the molecular mechanism implicated in neuronal development and may provide novel therapeutic targets in neurodegenerative disorders.
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Affiliation(s)
- Raquel Talens-Visconti
- Department of Cellular Pathology, Centro de Investigación Príncipe Felipe, Valencia, Spain
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Kuramoto K, Negishi M, Katoh H. Regulation of dendrite growth by the Cdc42 activator Zizimin1/Dock9 in hippocampal neurons. J Neurosci Res 2009; 87:1794-805. [PMID: 19156867 DOI: 10.1002/jnr.21997] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Rho family small GTPases are key regulators of morphological changes in neurons. Cdc42, one of the most characterized members of the Rho family of proteins, is involved in axon and dendrite outgrowth through cytoskeletal reorganization. Recent studies have identified Zizimin1, a member of the Dock180-related family of proteins [also called CDM (Ced-5/Dock180/Myoblast city)-zizimin homology (CZH) proteins], as a specific guanine-nucleotide exchange factor (GEF) for Cdc42. However, the physiological function of Zizimin1 is totally unknown. In this study, we investigated the role of Zizimin1 in dendrite development in rat hippocampal neurons. In situ hybridization and Western blot analysis showed that Zizimin1 is strongly expressed in the developing brain including in the hippocampus and cerebral cortex in late developmental stages. Overexpression of wild-type Zizimin1 promoted dendrite growth, whereas knockdown of Zizimin1 by short hairpin RNA or expression of a mutant Zizimin1 lacking Cdc42 GEF activity suppressed dendrite growth in primary cultured rat hippocampal neurons. Both the N-terminal CZH1 domain, which is conserved among CZH proteins, and the Pleckstrin homology domain of Zizimin1 are involved in membrane localization, Cdc42 activation, and regulation of dendrite growth. Thus, these results suggest that Zizimin1 plays an important role in dendrite growth in hippocampal neurons through activation of Cdc42.
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Affiliation(s)
- Kazuya Kuramoto
- Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
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39
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RhoE is spatiotemporally regulated in the postnatal mouse CNS. Neuroscience 2009; 163:586-93. [PMID: 19589369 DOI: 10.1016/j.neuroscience.2009.06.062] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2009] [Revised: 06/25/2009] [Accepted: 06/29/2009] [Indexed: 12/23/2022]
Abstract
Rnd proteins are a family of small GTPases that have been involved in axon path finding and CNS development by their control of actin cytoskeleton dynamics. Rnd proteins are constitutively activated and, subsequently, their functions determined by their localization and expression levels. In this work we have analyzed by Western blot and immunohistochemistry the levels and localization of Rnd3/RhoE during mouse postnatal development. CNS was found to be the main tissue for RhoE protein expression, which was detected in all regions of the adult brain and spinal cord, with the highest levels in the olfactory bulb and cortex. RhoE protein levels were considerably higher in all the regions of the CNS the first 2-3 weeks of postnatal development, undergoing later a decrease that led to low levels in the adult. Immunohistochemical detection of RhoE at postnatal day 21 showed an intense and widespread labelling throughout the CNS. RhoE immunoreactivity was detected in the granular and mitral cells and anterior olfactory nuclei of the olfactory bulb and in all cerebral layers. In the striatum, diencephalon, mesencephalon, pons, medulla oblongata and spinal cord, RhoE was widely distributed with higher intensity in the motoneurones and in some brainstem nuclei such as the red nucleus or the reticulotegmental nucleus. The pyramidal cells of CA1-3 and the polymorph layer, but not the granular cells of the dentate gyrus in the hippocampus were strongly labelled. At earlier stages the labelling was nearly similar; however, a prominent labelling was detected in the cells of the rostral migratory stream and in the external granule cells of the cerebellum. Our results suggest that RhoE can play important roles in the postnatal development and maturation of the CNS, especially in the migratory processes affecting the neurones.
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Ueda S, Fujimoto S, Hiramoto K, Negishi M, Katoh H. Dock4 regulates dendritic development in hippocampal neurons. J Neurosci Res 2009; 86:3052-61. [PMID: 18615735 DOI: 10.1002/jnr.21763] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Dendrite development is required for establishing proper neuronal connectivity. Rho-family small GTPases have been reported to play important roles in the regulation of dendritic growth and morphology. However, the molecular mechanisms that control the activities of Rho GTPases in developing dendrites are not well understood. In the present study we found Dock4, an activator of the small GTPase Rac, to have a role in regulating dendritic growth and branching in rat hippocampal neurons. Dock4 is highly expressed in the developing rat brain, predominantly in hippocampal neurons. In dissociated cultured hippocampal neurons, the expression of Dock4 protein is up-regulated after between 3 and 8 days in culture, when dendrites begin to grow. Knockdown of endogenous Dock4 results in reduced dendritic growth and branching. Conversely, overexpression of Dock4 with its binding partner ELMO2 enhances the numbers of dendrites and dendritic branches. These morphological effects elicited by Dock4 and ELMO2 require Rac activation and the C-terminal Crk-binding region of Dock4. Indeed, Dock4 forms a complex with ELMO2 and CrkII in hippocampal neurons. These findings demonstrate a new function of the Rac activator Dock4 in dendritic morphogenesis in hippocampal neurons.
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Affiliation(s)
- Shuhei Ueda
- Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
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41
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Li YH, Ghavampur S, Bondallaz P, Will L, Grenningloh G, Pu Schel AW. Rnd1 regulates axon extension by enhancing the microtubule destabilizing activity of SCG10. J Biol Chem 2008; 284:363-371. [PMID: 18996843 DOI: 10.1074/jbc.m808126200] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The GTPase Rnd1 affects actin dynamics antagonistically to Rho and has been implicated in the regulation of neurite outgrowth, dendrite development, and axon guidance. Here we show that Rnd1 interacts with the microtubule regulator SCG10. This interaction requires a central domain of SCG10 comprising about 40 amino acids located within the N-terminal-half of a putative alpha-helical domain and is independent of phosphorylation at the four identified phosphorylation sites that regulate SCG10 activity. Rnd1 enhances the microtubule destabilizing activity of SCG10 and both proteins colocalize in neurons. Knockdown of Rnd1 or SCG10 by RNAi suppressed axon extension, indicating a critical role for both proteins during neuronal differentiation. Overexpression of Rnd1 in neurons induces the formation of multiple axons. The effect of Rnd1 on axon extension depends on SCG10. These results indicate that SCG10 acts as an effector downstream of Rnd1 to regulate axon extensions by modulating microtubule organization.
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Affiliation(s)
- Ying-Hua Li
- Abteilung Molekularbiologie, Institut fu¨r Allgemeine Zoologie und Genetik, Westfa¨lische Wilhelms-Universita¨t Mu¨nster, Schloßplatz 5, D-48149 Mu¨nster, Germany and the Center for Psychiatric Neuroscience, Department of Psychiatry-Centre Hospitalier Universitaire Vaudois, University of Lausanne, 1008 Prilly, Switzerland
| | - Sharang Ghavampur
- Abteilung Molekularbiologie, Institut fu¨r Allgemeine Zoologie und Genetik, Westfa¨lische Wilhelms-Universita¨t Mu¨nster, Schloßplatz 5, D-48149 Mu¨nster, Germany and the Center for Psychiatric Neuroscience, Department of Psychiatry-Centre Hospitalier Universitaire Vaudois, University of Lausanne, 1008 Prilly, Switzerland
| | - Percy Bondallaz
- Abteilung Molekularbiologie, Institut fu¨r Allgemeine Zoologie und Genetik, Westfa¨lische Wilhelms-Universita¨t Mu¨nster, Schloßplatz 5, D-48149 Mu¨nster, Germany and the Center for Psychiatric Neuroscience, Department of Psychiatry-Centre Hospitalier Universitaire Vaudois, University of Lausanne, 1008 Prilly, Switzerland
| | - Lena Will
- Abteilung Molekularbiologie, Institut fu¨r Allgemeine Zoologie und Genetik, Westfa¨lische Wilhelms-Universita¨t Mu¨nster, Schloßplatz 5, D-48149 Mu¨nster, Germany and the Center for Psychiatric Neuroscience, Department of Psychiatry-Centre Hospitalier Universitaire Vaudois, University of Lausanne, 1008 Prilly, Switzerland
| | - Gabriele Grenningloh
- Abteilung Molekularbiologie, Institut fu¨r Allgemeine Zoologie und Genetik, Westfa¨lische Wilhelms-Universita¨t Mu¨nster, Schloßplatz 5, D-48149 Mu¨nster, Germany and the Center for Psychiatric Neuroscience, Department of Psychiatry-Centre Hospitalier Universitaire Vaudois, University of Lausanne, 1008 Prilly, Switzerland
| | - Andreas W Pu Schel
- Abteilung Molekularbiologie, Institut fu¨r Allgemeine Zoologie und Genetik, Westfa¨lische Wilhelms-Universita¨t Mu¨nster, Schloßplatz 5, D-48149 Mu¨nster, Germany and the Center for Psychiatric Neuroscience, Department of Psychiatry-Centre Hospitalier Universitaire Vaudois, University of Lausanne, 1008 Prilly, Switzerland.
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Iwasato T, Katoh H, Nishimaru H, Ishikawa Y, Inoue H, Saito YM, Ando R, Iwama M, Takahashi R, Negishi M, Itohara S. Rac-GAP alpha-chimerin regulates motor-circuit formation as a key mediator of EphrinB3/EphA4 forward signaling. Cell 2007; 130:742-53. [PMID: 17719550 DOI: 10.1016/j.cell.2007.07.022] [Citation(s) in RCA: 132] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2007] [Revised: 05/24/2007] [Accepted: 07/16/2007] [Indexed: 11/16/2022]
Abstract
The ephrin/Eph system plays a central role in neuronal circuit formation; however, its downstream effectors are poorly understood. Here we show that alpha-chimerin Rac GTPase-activating protein mediates ephrinB3/EphA4 forward signaling. We discovered a spontaneous mouse mutation, miffy (mfy), which results in a rabbit-like hopping gait, impaired corticospinal axon guidance, and abnormal spinal central pattern generators. Using positional cloning, transgene rescue, and gene targeting, we demonstrated that loss of alpha-chimerin leads to mfy phenotypes similar to those of EphA4(-/-) and ephrinB3(-/-) mice. alpha-chimerin interacts with EphA4 and, in response to ephrinB3/EphA4 signaling, inactivates Rac, which is a positive regulator of process outgrowth. Moreover, downregulation of alpha-chimerin suppresses ephrinB3-induced growth cone collapse in cultured neurons. Our findings indicate that ephrinB3/EphA4 signaling prevents growth cone extension in motor circuit formation via alpha-chimerin-induced inactivation of Rac. They also highlight the role of a Rho family GTPase-activating protein as a key mediator of ephrin/Eph signaling.
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MESH Headings
- Animals
- Animals, Newborn
- Cells, Cultured
- Cerebral Cortex/cytology
- Chimerin 1/metabolism
- Chromosomes, Mammalian
- Crosses, Genetic
- Ephrin-B3/genetics
- Ephrin-B3/metabolism
- Genes, Recessive
- Genetic Linkage
- Mice
- Mice, Inbred C57BL
- Mice, Inbred DBA
- Mice, Knockout
- Mice, Transgenic
- Molecular Sequence Data
- Motor Activity/genetics
- Mutation
- N-Methylaspartate/pharmacology
- Neurons/cytology
- Neurons/metabolism
- Polymorphism, Single Nucleotide
- Serotonin/pharmacology
- Signal Transduction
- Spinal Cord/drug effects
- rac GTP-Binding Proteins/physiology
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Affiliation(s)
- Takuji Iwasato
- Laboratory for Behavioral Genetics, RIKEN Brain Science Institute (BSI), 2-1 Hirosawa Wako-shi, Saitama 351-0198, Japan
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43
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Marie-Claire C, Salzmann J, David A, Courtin C, Canestrelli C, Noble F. Rnd family genes are differentially regulated by 3,4-methylenedioxymethamphetamine and cocaine acute treatment in mice brain. Brain Res 2006; 1134:12-7. [PMID: 17196187 DOI: 10.1016/j.brainres.2006.11.065] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2006] [Revised: 11/17/2006] [Accepted: 11/26/2006] [Indexed: 01/28/2023]
Abstract
Drugs of abuse induce alterations in cytoskeletal and cytoskeleton associated genes in several brain areas. We have previously shown that acute MDMA regulates the mRNA level of Rnd3, a Rho GTPase involved in actin cytoskeleton regulation, in mice striatum. In this study we investigated the effects of single administration of cocaine, another psychostimulant with a slightly different mechanism of action, on the mRNA levels of the three members of the Rnd genes family (Rnd1, Rnd2 and Rnd3). Mice were treated with either MDMA (9 mg/kg) or cocaine (20 mg/jg) and brain samples (i.e. hippocampus, striatum and prefrontal cortex) were processed for quantitative real-time PCR assay 1, 2, 4 and 6 h after the injections. The expression level of Rnd2 was differentially affected depending on the drug, brain area and time point after injection. Interestingly the two drugs up-regulate Rnd3 gene expression in the three structures tested with some differences in the timing. The effects of MDMA on Rnd3 appear earlier in the hippocampus as compared to cocaine, while it is the opposite in the prefrontal cortex. However, in the dorsal striatum, the two drugs induce an early and significant up-regulation of Rnd3 expression that is longer-lasting in the case of MDMA. In the case of cocaine contrarily to what was observed with MDMA, this modulation could not be blocked with the ERK activation inhibitor SL327 suggesting that the two drugs lead to the same effect on Rnd3 by two distinct pathways.
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Affiliation(s)
- Cynthia Marie-Claire
- CNRS, UMR7157, INSERM, U705, Universite Paris Descartes, Neuropsychopharmacologie des addictions, Paris, F-75006 France
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44
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Kakimoto T, Katoh H, Negishi M. Regulation of neuronal morphology by Toca-1, an F-BAR/EFC protein that induces plasma membrane invagination. J Biol Chem 2006; 281:29042-53. [PMID: 16885158 DOI: 10.1074/jbc.m604025200] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Actin reorganization is important for regulation of neuronal morphology. Neural Wiskott-Aldrich syndrome protein (N-WASP) is an important regulator of actin polymerization and also known to be strongly expressed in brain. Recently, Toca-1 (transducer of Cdc42-dependent actin assembly) has been shown to be required for Cdc42 to activate N-WASP from biochemical experiments. Toca-1 has three functional domains: an F-BAR/EFC domain at the N terminus, an HR1 at the center, and an SH3 domain at the C terminus. The F-BAR/EFC domain induces tubular invagination of plasma membrane, while Toca-1 binds both N-WASP and Cdc42 through the SH3 domain and the HR1, respectively. However, the physiological role of Toca-1 is completely unknown. Here we have investigated the neural function of Toca-1. Toca-1 is strongly expressed in neurons including hippocampal neurons in developing brain at early times. Knockdown of Toca-1 in PC12 cells significantly enhances neurite elongation. Consistently, overexpression of Toca-1 suppresses neurite elongation through the F-BAR/EFC domain with a membrane invaginating property, suggesting an implication of membrane trafficking in the neural function of Toca-1. In addition, knockdown of N-WASP, to our surprise, also enhances neurite elongation in PC12 cells, which is in clear contrast to the previous report that dominant negative mutants of N-WASP suppress neurite extension in PC12 cells. On the other hand, knockdown of Toca-1 in cultured rat hippocampal neurons enhances axon branching a little but not axon elongation, while knockdown of N-WASP enhances both axon elongation and branching. These results suggest that a vesicle trafficking regulator Toca-1 regulates different aspects of neuronal morphology from N-WASP.
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Affiliation(s)
- Tetsuhiro Kakimoto
- Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
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45
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Calabrese B, Wilson MS, Halpain S. Development and regulation of dendritic spine synapses. Physiology (Bethesda) 2006; 21:38-47. [PMID: 16443821 DOI: 10.1152/physiol.00042.2005] [Citation(s) in RCA: 175] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Dendritic spines are small protrusions from neuronal dendrites that form the postsynaptic component of most excitatory synapses in the brain. They play critical roles in synaptic transmission and plasticity. Recent advances in imaging and molecular technologies reveal that spines are complex, dynamic structures that contain a dense array of cytoskeletal, transmembrane, and scaffolding molecules. Several neurological and psychiatric disorders exhibit dendritic spine abnormalities.
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Affiliation(s)
- Barbara Calabrese
- Department of Cell Biology and Institute for Childhood and Neglected Diseases, The Scripps Research Institute, La Jolla, California, USA
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46
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Abstract
The Rnd proteins, which form a distinct sub-group of the Rho family of small GTP-binding proteins, have been shown to regulate the organization of the actin cytoskeleton in several tissues. In the brain, they participate in neurite extension, whereas in smooth muscle, they modulate contractility. Recent evidence has shown that Rnd3 (RhoE) is also involved in the regulation of cell-cycle progression and transformation, indicating that these proteins might have other, as yet unexplored roles.
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Affiliation(s)
- Pierre Chardin
- Institut de Pharmacologie Moleculaire et Cellulaire, Centre National de la Recherche Scientifique, 660 Route des Lucioles, Sophia Antipolis, 06560 Valbonne, France.
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47
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Ishikawa Y, Katoh H, Negishi M. Small GTPase Rnd1 is involved in neuronal activity-dependent dendritic development in hippocampal neurons. Neurosci Lett 2006; 400:218-23. [PMID: 16530331 DOI: 10.1016/j.neulet.2006.02.064] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2006] [Revised: 02/20/2006] [Accepted: 02/20/2006] [Indexed: 10/24/2022]
Abstract
Rho family small GTPases are key regulators for neuronal morphogenesis including dendritogenesis. We recently have shown that Rnd1, a member of the Rho family, is highly expressed in brain during the synaptogenic stage and is involved in dendritic spine formation. However, the mechanism by which Rnd1 regulates dendritic development including spine morphogenesis remains unknown. Here we report that Rnd1, a member of the Rho family, plays a critical role in neuronal activity-dependent dendritic development in hippocampal neurons. Overexpression of Rnd1 promoted dendritic growth and branching in cultured hippocampal neurons. On the other hand, suppression of endogenous Rnd1 expression by RNA interference significantly inhibited neuronal activity-dependent dendritic development and this inhibitory effect was canceled by inhibition of RhoA effector ROCK. In addition, knockdown of Rnd1 also abolished dendritic development promoted by treatment with brain-derived neurotrophic factor in hippocampal neurons. Our findings demonstrate that Rnd1 is involved in signaling pathways of neuronal activity-dependent dendritic development.
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Affiliation(s)
- Yukio Ishikawa
- Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
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48
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Tanaka H, Katoh H, Negishi M. Pragmin, a novel effector of Rnd2 GTPase, stimulates RhoA activity. J Biol Chem 2006; 281:10355-64. [PMID: 16481321 DOI: 10.1074/jbc.m511314200] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Rho family of small GTPases has been implicated in the reorganization of actin cytoskeleton and subsequent morphological changes in various cells. Rnd2 is a member of the Rnd subfamily, comprising Rnd1, Rnd2, and Rnd3. In contrast to Rnd1 and Rnd3, displaying an antagonistic action for RhoA signaling, signaling pathways of Rnd2 are not well known. Here we have performed a yeast two-hybrid screen using Rnd2 as bait and identified a novel Rnd2 effector protein, predominantly expressed in neurons, including cortical and hippocampal neurons. We named it Pragmin (pragma of Rnd2). In in vivo and in vitro binding assays, Pragmin specifically binds to Rnd2 among the Rho family GTPases in a GTP-dependent manner. Rnd2-bound Pragmin significantly stimulates RhoA activity and induces cell contraction through RhoA and the Rho-kinase pathway in HeLa cells. In PC12 cells, expressing Pragmin inhibits nerve growth factor-induced neurite outgrowth in response to Rnd2, and knock-down of Pragmin by Pragmin-specific small interfering RNA enhances neurite elongation. Therefore, Rnd2 regulates neurite outgrowth by functioning as the RhoA activator through Pragmin, in contrast to Rnd1 and Rnd3 inhibiting RhoA signaling.
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Affiliation(s)
- Hiroko Tanaka
- Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
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49
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Tada T, Sheng M. Molecular mechanisms of dendritic spine morphogenesis. Curr Opin Neurobiol 2006; 16:95-101. [PMID: 16361095 DOI: 10.1016/j.conb.2005.12.001] [Citation(s) in RCA: 512] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2005] [Accepted: 12/02/2005] [Indexed: 11/29/2022]
Abstract
Excitatory synapses are formed on dendritic spines, postsynaptic structures that change during development and in response to synaptic activity. Once mature, however, spines can remain stable for many months. The molecular mechanisms that control the formation and elimination, motility and stability, and size and shape of dendritic spines are being revealed. Multiple signaling pathways, particularly those involving Rho and Ras family small GTPases, converge on the actin cytoskeleton to regulate spine morphology and dynamics bidirectionally. Numerous cell surface receptors, scaffold proteins and actin binding proteins are concentrated in spines and engaged in spine morphogenesis.
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Affiliation(s)
- Tomoko Tada
- The Picower Institute for Learning and Memory, RIKEN-MIT Neuroscience Research Center, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
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50
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Abstract
The three Rnd proteins, Rnd1, Rnd2 and RhoE/Rnd3, are a subset of Rho family proteins that are unusual in that they bind but do not hydrolyse GTP, and are therefore not regulated by the classical GTP/GDP conformational switch of small GTPases. Increased expression of each Rnd protein induces loss of stress fibres in cultured fibroblasts and epithelial cells, acting antagonistically to RhoA, which stimulates stress fibre formation. RhoE is farnesylated and localizes partly on membranes, including the Golgi and plasma membrane, and in the cytosol. RhoE inhibits RhoA signalling in part by binding to the RhoA-activated serine/threonine kinase ROCK I (Rho-associated kinase I), thereby preventing it from phosphorylating its targets. RhoE activity is itself regulated by phosphorylation by ROCK I on multiple sites. RhoE phosphorylation enhances its stability, leading to an increase in RhoE levels. In addition, phosphorylation reduces its association with membranes and correlates with its ability to induce loss of stress fibres. RhoE also acts independently of ROCK to inhibit cell cycle progression, in part by preventing translation of cyclin D1, and to inhibit transformation of fibroblasts by oncogenic H-Ras. RhoE is therefore a multifunctional protein whose localization and actions are regulated by phosphorylation.
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Affiliation(s)
- K Riento
- Ludwig Institute for Cancer Research, Royal Free and University College School of Medicine, 91 Riding House Street, London W1W 7BS, UK
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