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Mandlik DS, Mandlik SK, S A. Therapeutic implications of glycogen synthase kinase-3β in Alzheimer's disease: a novel therapeutic target. Int J Neurosci 2024; 134:603-619. [PMID: 36178363 DOI: 10.1080/00207454.2022.2130297] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 09/03/2022] [Accepted: 09/10/2022] [Indexed: 10/17/2022]
Abstract
Alzheimer's disease (AD) is an extremely popular neurodegenerative condition associated with dementia, responsible for around 70% of the cases. There are presently 50 million people living with dementia in the world, but this number is anticipated to increase to 152 million by 2050, posing a substantial socioeconomic encumbrance. Despite extensive research, the precise mechanisms that cause AD remain unidentified, and currently, no therapy is available. Numerous signalling paths related to AD neuropathology, including glycogen synthase kinase 3-β (GSK-3β), have been investigated as potential targets for the treatment of AD in current years.GSK-3β is a proline-directed serine/threonine kinase that is linked to a variety of biological activities, comprising glycogen metabolism to gene transcription. GSK-3β is also involved in the pathophysiology of sporadic as well as familial types of AD, which has led to the development of the GSK3 theory of AD. GSK-3β is a critical performer in the pathology of AD because dysregulation of this kinase affects all the main symbols of the disease such as amyloid formation, tau phosphorylation, neurogenesis and synaptic and memory function. The current review highlights present-day knowledge of GSK-3β-related neurobiology, focusing on its role in AD pathogenesis signalling pathways. It also explores the possibility of targeting GSK-3β for the management of AD and offers an overview of the present research work in preclinical and clinical studies to produce GSK-3β inhibitors.
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Affiliation(s)
- Deepa S Mandlik
- Department of Pharmacology, Poona College of Pharmacy, Bharati Vidyapeeth (Deemed to be University), Erandawane, Pune, India
| | - Satish K Mandlik
- Department of Pharmaceutics, Poona College of Pharmacy, Bharati Vidyapeeth (Deemed to be University), Erandawane, Pune, India
| | - Arulmozhi S
- Department of Pharmacology, Poona College of Pharmacy, Bharati Vidyapeeth (Deemed to be University), Erandawane, Pune, India
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2
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Dwivedi I, Haddad GG. Investigating the neurobiology of maternal opioid use disorder and prenatal opioid exposure using brain organoid technology. Front Cell Neurosci 2024; 18:1403326. [PMID: 38812788 PMCID: PMC11133580 DOI: 10.3389/fncel.2024.1403326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Accepted: 05/01/2024] [Indexed: 05/31/2024] Open
Abstract
Over the past two decades, Opioid Use Disorder (OUD) among pregnant women has become a major global public health concern. OUD has been characterized as a problematic pattern of opioid use despite adverse physical, psychological, behavioral, and or social consequences. Due to the relapsing-remitting nature of this disorder, pregnant mothers are chronically exposed to exogenous opioids, resulting in adverse neurological and neuropsychiatric outcomes. Collateral fetal exposure to opioids also precipitates severe neurodevelopmental and neurocognitive sequelae. At present, much of what is known regarding the neurobiological consequences of OUD and prenatal opioid exposure (POE) has been derived from preclinical studies in animal models and postnatal or postmortem investigations in humans. However, species-specific differences in brain development, variations in subject age/health/background, and disparities in sample collection or storage have complicated the interpretation of findings produced by these explorations. The ethical or logistical inaccessibility of human fetal brain tissue has also limited direct examinations of prenatal drug effects. To circumvent these confounding factors, recent groups have begun employing induced pluripotent stem cell (iPSC)-derived brain organoid technology, which provides access to key aspects of cellular and molecular brain development, structure, and function in vitro. In this review, we endeavor to encapsulate the advancements in brain organoid culture that have enabled scientists to model and dissect the neural underpinnings and effects of OUD and POE. We hope not only to emphasize the utility of brain organoids for investigating these conditions, but also to highlight opportunities for further technical and conceptual progress. Although the application of brain organoids to this critical field of research is still in its nascent stages, understanding the neurobiology of OUD and POE via this modality will provide critical insights for improving maternal and fetal outcomes.
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Affiliation(s)
- Ila Dwivedi
- Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Gabriel G. Haddad
- Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, CA, United States
- Department of Neurosciences, School of Medicine, University of California, San Diego, La Jolla, CA, United States
- Rady Children’s Hospital, San Diego, CA, United States
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3
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Peng L, Zhang D, Tu H, Wu D, Xiang S, Yang W, Zhao Y, Yang J. The role of Map1b in regulating osteoblast polarity, proliferation, differentiation and migration. Bone 2024; 181:117038. [PMID: 38316337 DOI: 10.1016/j.bone.2024.117038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 01/30/2024] [Accepted: 02/01/2024] [Indexed: 02/07/2024]
Abstract
Osteoblast polarity, proliferation, differentiation, and migration are essential for maintaining normal bone structure and function. While the microtubule-associated protein Map1b has been extensively studied in nerve cells, its role in bone cells is less known. We investigated the functional significance of Map1b in mouse bone marrow stromal cells (ST2) and elucidated its relationship and influence on cytoskeletal polarity and Golgi organization. Our results suggest that Map1b, as a microtubule regulatory protein, can also regulate the expression of cyclin PCNA, p-H3(S10) and migration-related protein integrin β1, thereby affecting the proliferation and migration of osteoblasts. The downstream target gene Rgc32 was screened by RNA sequencing. Furthermore, Map1b, as a downstream mediator, regulates the Wnt5a signaling pathway. This study expands our understanding of the involvement of Map1b in bone biology and highlights its crucial role in governing osteoblast polarity, proliferation, and migration, thereby providing a basis for developing novel therapeutic strategies targeting Map1b in orthopedic medicine and promoting precision treatment modalities. Further investigations on the precise mechanisms underlying Map1b's influence on bone cell function and disease progression are needed.
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Affiliation(s)
- Li Peng
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, China; State Key Laboratory of Oral Diseases, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Dept. of Cariology and Endodontics West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China
| | - Demao Zhang
- State Key Laboratory of Oral Diseases, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Dept. of Cariology and Endodontics West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China
| | - Heng Tu
- State Key Laboratory of Oral Diseases, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Dept. of Cariology and Endodontics West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China
| | - Dan Wu
- State Key Laboratory of Oral Diseases, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Dept. of Cariology and Endodontics West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China
| | - Shuaixi Xiang
- State Key Laboratory of Oral Diseases, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Dept. of Cariology and Endodontics West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China
| | - Wenbin Yang
- State Key Laboratory of Oral Diseases, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Dept. of Cariology and Endodontics West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China
| | - Yun Zhao
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, China
| | - Jing Yang
- State Key Laboratory of Oral Diseases, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Dept. of Cariology and Endodontics West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China.
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4
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Gu X, Jia C, Wang J. Advances in Understanding the Molecular Mechanisms of Neuronal Polarity. Mol Neurobiol 2023; 60:2851-2870. [PMID: 36738353 DOI: 10.1007/s12035-023-03242-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 01/22/2023] [Indexed: 02/05/2023]
Abstract
The establishment and maintenance of neuronal polarity are important for neural development and function. Abnormal neuronal polarity establishment commonly leads to a variety of neurodevelopmental disorders. Over the past three decades, with the continuous development and improvement of biological research methods and techniques, we have made tremendous progress in the understanding of the molecular mechanisms of neuronal polarity establishment. The activity of positive and negative feedback signals and actin waves are both essential in this process. They drive the directional transport and aggregation of key molecules of neuronal polarity, promote the spatiotemporal regulation of ordered and coordinated interactions of actin filaments and microtubules, stimulate the specialization and growth of axons, and inhibit the formation of multiple axons. In this review, we focus on recent advances in these areas, in particular the important findings about neuronal polarity in two classical models, in vitro primary hippocampal/cortical neurons and in vivo cortical pyramidal neurons, and discuss our current understanding of neuronal polarity..
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Affiliation(s)
- Xi Gu
- Fujian Key Laboratory for Translational Research in Cancer and Neurodegenerative Diseases, Institute for Translational Medicine, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China.
| | - Chunhong Jia
- Department of Pediatrics, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
| | - Junhao Wang
- Fujian Key Laboratory for Translational Research in Cancer and Neurodegenerative Diseases, Institute for Translational Medicine, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
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5
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Kounoupa Z, Tivodar S, Theodorakis K, Kyriakis D, Denaxa M, Karagogeos D. Rac1 and Rac3 GTPases and TPC2 are required for axonal outgrowth and migration of cortical interneurons. J Cell Sci 2023; 136:286920. [PMID: 36744839 DOI: 10.1242/jcs.260373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 01/31/2023] [Indexed: 02/07/2023] Open
Abstract
Rho GTPases, among them Rac1 and Rac3, are major transducers of extracellular signals and are involved in multiple cellular processes. In cortical interneurons, the neurons that control the balance between excitation and inhibition of cortical circuits, Rac1 and Rac3 are essential for their development. Ablation of both leads to a severe reduction in the numbers of mature interneurons found in the murine cortex, which is partially due to abnormal cell cycle progression of interneuron precursors and defective formation of growth cones in young neurons. Here, we present new evidence that upon Rac1 and Rac3 ablation, centrosome, Golgi complex and lysosome positioning is significantly perturbed, thus affecting both interneuron migration and axon growth. Moreover, for the first time, we provide evidence of altered expression and localization of the two-pore channel 2 (TPC2) voltage-gated ion channel that mediates Ca2+ release. Pharmacological inhibition of TPC2 negatively affected axonal growth and migration of interneurons. Our data, taken together, suggest that TPC2 contributes to the severe phenotype in axon growth initiation, extension and interneuron migration in the absence of Rac1 and Rac3.
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Affiliation(s)
- Zouzana Kounoupa
- Institute of Molecular Biology and Biotechnology (IMBB, FORTH), Heraklion 71110, Greece.,Department of Basic Science, Faculty of Medicine, University of Crete, Heraklion 71110, Greece
| | - Simona Tivodar
- Institute of Molecular Biology and Biotechnology (IMBB, FORTH), Heraklion 71110, Greece.,Department of Basic Science, Faculty of Medicine, University of Crete, Heraklion 71110, Greece
| | - Kostas Theodorakis
- Institute of Molecular Biology and Biotechnology (IMBB, FORTH), Heraklion 71110, Greece.,Department of Basic Science, Faculty of Medicine, University of Crete, Heraklion 71110, Greece
| | - Dimitrios Kyriakis
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, L-4365 Esch-sur-Alzette, Luxembourg
| | - Myrto Denaxa
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Centre 'Al. Fleming', Vari, 16672, Greece
| | - Domna Karagogeos
- Institute of Molecular Biology and Biotechnology (IMBB, FORTH), Heraklion 71110, Greece.,Department of Basic Science, Faculty of Medicine, University of Crete, Heraklion 71110, Greece
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Razmara P, Pyle GG. Impact of Copper Nanoparticles and Copper Ions on Transcripts Involved in Neural Repair Mechanisms in Rainbow Trout Olfactory Mucosa. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2023; 84:18-31. [PMID: 36525054 DOI: 10.1007/s00244-022-00969-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 11/22/2022] [Indexed: 06/17/2023]
Abstract
Olfactory mucosa is well known for its lifelong ability for regeneration. Regeneration of neurons and regrowth of severed axons are the most common neural repair mechanisms in olfactory mucosa. Nonetheless, exposure to neurotoxic contaminants, such as copper nanoparticles (CuNPs) and copper ions (Cu2+), may alter the reparative capacity of olfactory mucosa. Here, using RNA-sequencing, we investigated the molecular basis of neural repair mechanisms that were affected by CuNPs and Cu2+ in rainbow trout olfactory mucosa. The transcript profile of olfactory mucosa suggested that regeneration of neurons was inhibited by CuNPs. Exposure to CuNPs reduced the transcript abundances of pro-inflammatory proteins which are required to initiate neuroregeneration. Moreover, the transcript of genes encoding regeneration promoters, including canonical Wnt/β-catenin signaling proteins and developmental transcription factors, were downregulated in the CuNP-treated fish. The mRNA levels of genes regulating axonal regrowth, including the growth-promoting signals secreted from olfactory ensheathing cells, were mainly increased in the CuNP treatment. However, the reduced transcript abundances of a few cell adhesion molecules and neural polarity genes may restrict axonogenesis in the CuNP-exposed olfactory mucosa. In the Cu2+-treated olfactory mucosa, both neural repair strategies were initiated at the transcript level. The stimulation of repair mechanisms can lead to the recovery of Cu2+-induced olfactory dysfunction. These results indicated CuNPs and Cu2+ differentially affected the neural repair mechanism in olfactory mucosa. Exposure to CuNP had greater effects on the expression of genes involved in olfactory repair mechanisms relative to Cu2+ and dysregulated the transcripts associated with stem cell proliferation and neural reconstitution.
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Affiliation(s)
- Parastoo Razmara
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB, Canada.
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada.
| | - Gregory G Pyle
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB, Canada
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7
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Al-Farsi H, Al-Azwani I, Malek JA, Chouchane L, Rafii A, Halabi NM. Discovery of new therapeutic targets in ovarian cancer through identifying significantly non-mutated genes. J Transl Med 2022; 20:244. [PMID: 35619151 PMCID: PMC9134657 DOI: 10.1186/s12967-022-03440-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 05/13/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mutated and non-mutated genes interact to drive cancer growth and metastasis. While research has focused on understanding the impact of mutated genes on cancer biology, understanding non-mutated genes that are essential to tumor development could lead to new therapeutic strategies. The recent advent of high-throughput whole genome sequencing being applied to many different samples has made it possible to calculate if genes are significantly non-mutated in a specific cancer patient cohort. METHODS We carried out random mutagenesis simulations of the human genome approximating the regions sequenced in the publicly available Cancer Growth Atlas Project for ovarian cancer (TCGA-OV). Simulated mutations were compared to the observed mutations in the TCGA-OV cohort and genes with the largest deviations from simulation were identified. Pathway analysis was performed on the non-mutated genes to better understand their biological function. We then compared gene expression, methylation and copy number distributions of non-mutated and mutated genes in cell lines and patient data from the TCGA-OV project. To directly test if non-mutated genes can affect cell proliferation, we carried out proof-of-concept RNAi silencing experiments of a panel of nine selected non-mutated genes in three ovarian cancer cell lines and one primary ovarian epithelial cell line. RESULTS We identified a set of genes that were mutated less than expected (non-mutated genes) and mutated more than expected (mutated genes). Pathway analysis revealed that non-mutated genes interact in cancer associated pathways. We found that non-mutated genes are expressed significantly more than mutated genes while also having lower methylation and higher copy number states indicating that they could be functionally important. RNAi silencing of the panel of non-mutated genes resulted in a greater significant reduction of cell viability in the cancer cell lines than in the non-cancer cell line. Finally, as a test case, silencing ANKLE2, a significantly non-mutated gene, affected the morphology, reduced migration, and increased the chemotherapeutic response of SKOV3 cells. CONCLUSION We show that we can identify significantly non-mutated genes in a large ovarian cancer cohort that are well-expressed in patient and cell line data and whose RNAi-induced silencing reduces viability in three ovarian cancer cell lines. Targeting non-mutated genes that are important for tumor growth and metastasis is a promising approach to expand cancer therapeutic options.
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Affiliation(s)
| | | | - Joel A Malek
- Genomics Core, Weill Cornell Medicine in Qatar, Education City, Qatar Foundation, Doha, Qatar
| | - Lotfi Chouchane
- Genetic Intelligence Laboratory, Weill Cornell Medicine in Qatar, Education City, Qatar Foundation, Doha, Qatar
| | - Arash Rafii
- Genetic Intelligence Laboratory, Weill Cornell Medicine in Qatar, Education City, Qatar Foundation, Doha, Qatar.
| | - Najeeb M Halabi
- Genetic Intelligence Laboratory, Weill Cornell Medicine in Qatar, Education City, Qatar Foundation, Doha, Qatar.
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Wilson C, Moyano AL, Cáceres A. Perspectives on Mechanisms Supporting Neuronal Polarity From Small Animals to Humans. Front Cell Dev Biol 2022; 10:878142. [PMID: 35517494 PMCID: PMC9062071 DOI: 10.3389/fcell.2022.878142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 04/04/2022] [Indexed: 11/23/2022] Open
Abstract
Axon-dendrite formation is a crucial milestone in the life history of neurons. During this process, historically referred as “the establishment of polarity,” newborn neurons undergo biochemical, morphological and functional transformations to generate the axonal and dendritic domains, which are the basis of neuronal wiring and connectivity. Since the implementation of primary cultures of rat hippocampal neurons by Gary Banker and Max Cowan in 1977, the community of neurobiologists has made significant achievements in decoding signals that trigger axo-dendritic specification. External and internal cues able to switch on/off signaling pathways controlling gene expression, protein stability, the assembly of the polarity complex (i.e., PAR3-PAR6-aPKC), cytoskeleton remodeling and vesicle trafficking contribute to shape the morphology of neurons. Currently, the culture of hippocampal neurons coexists with alternative model systems to study neuronal polarization in several species, from single-cell to whole-organisms. For instance, in vivo approaches using C. elegans and D. melanogaster, as well as in situ imaging in rodents, have refined our knowledge by incorporating new variables in the polarity equation, such as the influence of the tissue, glia-neuron interactions and three-dimensional development. Nowadays, we have the unique opportunity of studying neurons differentiated from human induced pluripotent stem cells (hiPSCs), and test hypotheses previously originated in small animals and propose new ones perhaps specific for humans. Thus, this article will attempt to review critical mechanisms controlling polarization compiled over decades, highlighting points to be considered in new experimental systems, such as hiPSC neurons and human brain organoids.
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The roles of DNA methylation and hydroxymethylation at short interspersed nuclear elements in the hypothalamic arcuate nucleus during puberty. MOLECULAR THERAPY-NUCLEIC ACIDS 2021; 26:242-252. [PMID: 34513307 PMCID: PMC8413674 DOI: 10.1016/j.omtn.2021.07.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 07/13/2021] [Indexed: 12/26/2022]
Abstract
Puberty is the gateway to adult reproductive competence, encompassing a suite of complex, integrative, and coordinated changes in neuroendocrine functions. However, the regulatory mechanisms of transcriptional reprogramming in the arcuate nucleus (ARC) during onset of puberty are still not fully understood. To understand the role of epigenetics in regulating gene expression, mouse hypothalamic ARCs were isolated at 4 and 8 weeks, and the transcriptome, DNA hydroxymethylation, DNA methylation, and chromatin accessibility were assessed via RNA sequencing (RNA-seq), reduced representation bisulfite sequencing (RRBS-seq), reduced representation hydroxymethylation profiling (RRHP)-seq, and assay for transposase-accessible chromatin (ATAC-seq), respectively. The overall DNA hydroxymethylation and DNA methylation changes in retroelements (REs) were associated with gene expression modeling for puberty in the ARC. We focused on analyzing DNA hydroxymethylation and DNA methylation at two short interspersed nuclear elements (SINEs) located on the promoter of the 5-hydroxytryptamine receptor 6 (Htr6) gene and the enhancer of the KISS-1 metastasis suppressor (Kiss1) gene and investigated their regulatory roles in gene expression. Our data uncovered a novel epigenetic mechanism by which SINEs regulate gene expression during puberty.
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Overexpression of Lin28A in neural progenitor cells in vivo does not lead to brain tumor formation but results in reduced spine density. Acta Neuropathol Commun 2021; 9:185. [PMID: 34801069 PMCID: PMC8606090 DOI: 10.1186/s40478-021-01289-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 11/02/2021] [Indexed: 11/10/2022] Open
Abstract
LIN28A overexpression has been identified in malignant brain tumors called embryonal tumors with multilayered rosettes (ETMR) but its specific role during brain development remains largely unknown. Radial glia cells of the ventricular zone (VZ) are proposed as a cell of origin for ETMR. We asked whether an overexpression of LIN28A in such cells might affect brain development or result in the formation of brain tumors.Constitutive overexpression of LIN28A in hGFAP-cre::lsl-Lin28A (GL) mice led to a transient increase of proliferation in the cortical VZ at embryonic stages but no postnatal brain tumor formation. Postnatally, GL mice displayed a pyramidal cell layer dispersion of the hippocampus and altered spine and dendrite morphology, including reduced dendritic spine densities in the hippocampus and cortex. GL mice displayed hyperkinetic activity and differential quantitative MS-based proteomics revealed altered time dependent molecular functions regarding mRNA processing and spine morphogenesis. Phosphoproteomic analyses indicated a downregulation of mTOR pathway modulated proteins such as Map1b being involved in microtubule dynamics.In conclusion, we show that Lin28A overexpression transiently increases proliferation of neural precursor cells but it is not sufficient to drive brain tumors in vivo. In contrast, Lin28A impacts on protein abundancy patterns related to spine morphogenesis and phosphorylation levels of proteins involved in microtubule dynamics, resulting in decreased spine densities of neurons in the hippocampus and cortex as well as in altered behavior. Our work provides new insights into the role of LIN28A for neuronal morphogenesis and development and may reveal future targets for treatment of ETMR patients.
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Vallejo D, Lindsay CB, González-Billault C, Inestrosa NC. Wnt5a modulates dendritic spine dynamics through the regulation of Cofilin via small Rho GTPase activity in hippocampal neurons. J Neurochem 2021; 158:673-693. [PMID: 34107066 DOI: 10.1111/jnc.15448] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 06/03/2021] [Accepted: 06/07/2021] [Indexed: 01/21/2023]
Abstract
Dendritic spines are small, actin-rich protrusions that act as the receiving sites of most excitatory inputs in the central nervous system. The remodeling of the synapse architecture is mediated by actin cytoskeleton dynamics, a process precisely regulated by the small Rho GTPase family. Wnt ligands exert their presynaptic and postsynaptic effects during formation and consolidation of the synaptic structure. Specifically, Wnt5a has been identified as an indispensable synaptogenic factor for the regulation and organization of the postsynaptic side; however, the molecular mechanisms through which Wnt5a induces morphological changes resulting from actin cytoskeleton dynamics within dendritic spines remain unclear. In this work, we employ primary rat hippocampal cultures and HT22 murine hippocampal neuronal cell models, molecular and pharmacological tools, and fluorescence microscopy (laser confocal and epifluorescence) to define the Wnt5a-induced molecular signaling involved in postsynaptic remodeling mediated via the regulation of the small Rho GTPase family. We report that Wnt5a differentially regulates the phosphorylation of Cofilin in neurons through both Ras-related C3 botulinum toxin substrate 1 and cell division cycle 42 depending on the subcellular compartment and the extracellular calcium levels. Additionally, we demonstrate that Wnt5a increases the density of dendritic spines and promotes their maturation via Ras-related C3 botulinum toxin substrate 1. Accordingly, we find that Wnt5a requires the combined activation of small Rho GTPases to increase the levels of filamentous actin, thus promoting the stability of actin filaments. Altogether, these results provide evidence for a new mechanism by which Wnt5a may target actin dynamics, thereby regulating the subsequent morphological changes in dendritic spine architecture.
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Affiliation(s)
- Daniela Vallejo
- Centro de Envejecimiento y Regeneración (CARE), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Carolina B Lindsay
- Centro de Envejecimiento y Regeneración (CARE), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Christian González-Billault
- Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile.,Geroscience Center for Brain Health and Metabolism (GERO), Santiago, Chile.,The Buck Institute for Research on Aging, Novato, CA, USA
| | - Nibaldo C Inestrosa
- Centro de Envejecimiento y Regeneración (CARE), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Excelencia en Biomedicina de Magallanes (CEBIMA), Universidad de Magallanes, Punta Arenas, Chile
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12
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Gene Expression Changes of Humans with Primary Mitral Regurgitation and Reduced Left Ventricular Ejection Fraction. Int J Mol Sci 2021; 22:ijms22073454. [PMID: 33810615 PMCID: PMC8037976 DOI: 10.3390/ijms22073454] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 03/23/2021] [Accepted: 03/25/2021] [Indexed: 12/18/2022] Open
Abstract
Patients with primary mitral regurgitation (MR) may remain asymptomatic for many years. For unknown reasons, some shift from a compensated to a decompensated state and progress to fatal heart failure. To elucidate the genetic determinants of this process, we recruited 28 patients who underwent mitral valve surgery and stratified them into control, compensated MR, and decompensated MR groups. Tissue biopsies were obtained from the patients’ left ventricular (LV) lateral wall for a transcriptome-wide profiling of 64,769 probes to identify differentially expressed genes (DEGs). Using cutoff values at the 1% FDR significance level and sex- and age-adjusted regression models, we identified 12 significant DEGs (CTGF, MAP1B, SERPINE1, MYH9, MICAL2, MYO1D, CRY1, AQP7P3, HTRA1, PRSS23, IGFBP2, and FN1). The most significant gene was CTGF (adjusted R2 = 0.74, p = 1.80 × 10−8). We found that the majority of genes expressed in the more advanced decompensated MR group were pro-fibrotic genes associated with cardiac fibrosis. In particular, six pro-fibrotic genes (CTGF, SERPINE1, MYH9, HTRA1, PRSS23, and FN1) were overexpressed and enriched in pathways involved in ECM (extracellular matrix) protein remodeling. Therapeutic interventions that antagonize these six genes may slow the progression toward decompensated MR.
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13
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Neurodevelopmental signatures of narcotic and neuropsychiatric risk factors in 3D human-derived forebrain organoids. Mol Psychiatry 2021; 26:7760-7783. [PMID: 34158620 PMCID: PMC8873021 DOI: 10.1038/s41380-021-01189-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 05/20/2021] [Accepted: 06/01/2021] [Indexed: 02/06/2023]
Abstract
It is widely accepted that narcotic use during pregnancy and specific environmental factors (e.g., maternal immune activation and chronic stress) may increase risk of neuropsychiatric illness in offspring. However, little progress has been made in defining human-specific in utero neurodevelopmental pathology due to ethical and technical challenges associated with accessing human prenatal brain tissue. Here we utilized human induced pluripotent stem cells (hiPSCs) to generate reproducible organoids that recapitulate dorsal forebrain development including early corticogenesis. We systemically exposed organoid samples to chemically defined "enviromimetic" compounds to examine the developmental effects of various narcotic and neuropsychiatric-related risk factors within tissue of human origin. In tandem experiments conducted in parallel, we modeled exposure to opiates (μ-opioid agonist endomorphin), cannabinoids (WIN 55,212-2), alcohol (ethanol), smoking (nicotine), chronic stress (human cortisol), and maternal immune activation (human Interleukin-17a; IL17a). Human-derived dorsal forebrain organoids were consequently analyzed via an array of unbiased and high-throughput analytical approaches, including state-of-the-art TMT-16plex liquid chromatography/mass-spectrometry (LC/MS) proteomics, hybrid MS metabolomics, and flow cytometry panels to determine cell-cycle dynamics and rates of cell death. This pipeline subsequently revealed both common and unique proteome, reactome, and metabolome alterations as a consequence of enviromimetic modeling of narcotic use and neuropsychiatric-related risk factors in tissue of human origin. However, of our 6 treatment groups, human-derived organoids treated with the cannabinoid agonist WIN 55,212-2 exhibited the least convergence of all groups. Single-cell analysis revealed that WIN 55,212-2 increased DNA fragmentation, an indicator of apoptosis, in human-derived dorsal forebrain organoids. We subsequently confirmed induction of DNA damage and apoptosis by WIN 55,212-2 within 3D human-derived dorsal forebrain organoids. Lastly, in a BrdU pulse-chase neocortical neurogenesis paradigm, we identified that WIN 55,212-2 was the only enviromimetic treatment to disrupt newborn neuron numbers within human-derived dorsal forebrain organoids. Cumulatively this study serves as both a resource and foundation from which human 3D biologics can be used to resolve the non-genomic effects of neuropsychiatric risk factors under controlled laboratory conditions. While synthetic cannabinoids can differ from naturally occurring compounds in their effects, our data nonetheless suggests that exposure to WIN 55,212-2 elicits neurotoxicity within human-derived developing forebrain tissue. These human-derived data therefore support the long-standing belief that maternal use of cannabinoids may require caution so to avoid any potential neurodevelopmental effects upon developing offspring in utero.
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Francis F, Cappello S. Neuronal migration and disorders - an update. Curr Opin Neurobiol 2020; 66:57-68. [PMID: 33096394 DOI: 10.1016/j.conb.2020.10.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 09/15/2020] [Accepted: 10/04/2020] [Indexed: 12/22/2022]
Abstract
This review highlights genes, proteins and subcellular mechanisms, recently shown to influence cortical neuronal migration. A current view on mechanisms which become disrupted in a diverse array of migration disorders is presented. The microtubule (MT) cytoskeleton is a major player in migrating neurons. Recently, variable impacts on MTs have been revealed in different cell compartments. Thus there are a multiplicity of effects involving centrosomal, microtubule-associated, as well as motor proteins. However, other causative factors also emerge, illuminating cortical neuronal migration research. These include disruptions of the actin cytoskeleton, the extracellular matrix, different adhesion molecules and signaling pathways, especially revealed in disorders such as periventricular heterotopia. These recent advances often involve the use of human in vitro models as well as model organisms. Focusing on cell-type specific knockouts and knockins, as well as generating omics and functional data, all seem critical for an integrated view on neuronal migration dysfunction.
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Affiliation(s)
- Fiona Francis
- INSERM U 1270, Paris, France; Sorbonne University, UMR-S 1270, F-75005 Paris, France; Institut du Fer à Moulin, Paris, France.
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15
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Bodakuntla S, Jijumon AS, Villablanca C, Gonzalez-Billault C, Janke C. Microtubule-Associated Proteins: Structuring the Cytoskeleton. Trends Cell Biol 2019; 29:804-819. [PMID: 31416684 DOI: 10.1016/j.tcb.2019.07.004] [Citation(s) in RCA: 165] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 07/11/2019] [Accepted: 07/12/2019] [Indexed: 11/27/2022]
Abstract
Microtubule-associated proteins (MAPs) were initially discovered as proteins that bind to and stabilize microtubules. Today, an ever-growing number of MAPs reveals a more complex picture of these proteins as organizers of the microtubule cytoskeleton that have a large variety of functions. MAPs enable microtubules to participate in a plethora of cellular processes such as the assembly of mitotic and meiotic spindles, neuronal development, and the formation of the ciliary axoneme. Although some subgroups of MAPs have been exhaustively characterized, a strikingly large number of MAPs remain barely characterized other than their interactions with microtubules. We provide a comprehensive view on the currently known MAPs in mammals. We discuss their molecular mechanisms and functions, as well as their physiological role and links to pathologies.
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Affiliation(s)
- Satish Bodakuntla
- Institut Curie, Paris Sciences et Lettres (PSL) Research University, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 3348, F-91405 Orsay, France; Université Paris Sud, Université Paris-Saclay, CNRS UMR 3348, F-91405 Orsay, France
| | - A S Jijumon
- Institut Curie, Paris Sciences et Lettres (PSL) Research University, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 3348, F-91405 Orsay, France; Université Paris Sud, Université Paris-Saclay, CNRS UMR 3348, F-91405 Orsay, France
| | - Cristopher Villablanca
- Center for Geroscience, Brain Health, and Metabolism (GERO), Santiago, Chile; Department of Biology, Faculty of Sciences, University of Chile, Santiago, Chile
| | - Christian Gonzalez-Billault
- Center for Geroscience, Brain Health, and Metabolism (GERO), Santiago, Chile; Department of Biology, Faculty of Sciences, University of Chile, Santiago, Chile.
| | - Carsten Janke
- Institut Curie, Paris Sciences et Lettres (PSL) Research University, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 3348, F-91405 Orsay, France; Université Paris Sud, Université Paris-Saclay, CNRS UMR 3348, F-91405 Orsay, France.
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Bremer J, Marsden KC, Miller A, Granato M. The ubiquitin ligase PHR promotes directional regrowth of spinal zebrafish axons. Commun Biol 2019; 2:195. [PMID: 31149640 PMCID: PMC6531543 DOI: 10.1038/s42003-019-0434-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 04/16/2019] [Indexed: 01/05/2023] Open
Abstract
To reconnect with their synaptic targets, severed axons need to regrow robustly and directionally along the pre-lesional trajectory. While mechanisms directing axonal regrowth are poorly understood, several proteins direct developmental axon outgrowth, including the ubiquitin ligase PHR (Mycbp2). Invertebrate PHR also limits regrowth of injured axons, whereas its role in vertebrate axonal regrowth remains elusive. Here we took advantage of the high regrowth capacity of spinal zebrafish axons and observed robust and directional regrowth following laser transection of spinal Mauthner axons. We found that PHR directs regrowing axons along the pre-lesional trajectory and across the transection site. At the transection site, initial regrowth of wild-type axons was multidirectional. Over time, misdirected sprouts were corrected in a PHR-dependent manner. Ablation of cyfip2, known to promote F-actin-polymerization and pharmacological inhibition of JNK reduced misdirected regrowth of PHR-deficient axons, suggesting that PHR controls directional Mauthner axonal regrowth through cyfip2- and JNK-dependent pathways.
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Affiliation(s)
- Juliane Bremer
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, 19104 PA USA
| | - Kurt C. Marsden
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, 19104 PA USA
- Present Address: Department of Biological Sciences, North Carolina State University, Raleigh, 27607 NC USA
| | - Adam Miller
- Institute of Neuroscience, University of Oregon, Eugene, 97405 OR USA
| | - Michael Granato
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, 19104 PA USA
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17
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The Cytoskeleton-A Complex Interacting Meshwork. Cells 2019; 8:cells8040362. [PMID: 31003495 PMCID: PMC6523135 DOI: 10.3390/cells8040362] [Citation(s) in RCA: 181] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 04/15/2019] [Accepted: 04/15/2019] [Indexed: 12/22/2022] Open
Abstract
The cytoskeleton of animal cells is one of the most complicated and functionally versatile structures, involved in processes such as endocytosis, cell division, intra-cellular transport, motility, force transmission, reaction to external forces, adhesion and preservation, and adaptation of cell shape. These functions are mediated by three classical cytoskeletal filament types, as follows: Actin, microtubules, and intermediate filaments. The named filaments form a network that is highly structured and dynamic, responding to external and internal cues with a quick reorganization that is orchestrated on the time scale of minutes and has to be tightly regulated. Especially in brain tumors, the cytoskeleton plays an important role in spreading and migration of tumor cells. As the cytoskeletal organization and regulation is complex and many-faceted, this review aims to summarize the findings about cytoskeletal filament types, including substructures formed by them, such as lamellipodia, stress fibers, and interactions between intermediate filaments, microtubules and actin. Additionally, crucial regulatory aspects of the cytoskeletal filaments and the formed substructures are discussed and integrated into the concepts of cell motility. Even though little is known about the impact of cytoskeletal alterations on the progress of glioma, a final point discussed will be the impact of established cytoskeletal alterations in the cellular behavior and invasion of glioma.
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Melrose J. Keratan sulfate (KS)-proteoglycans and neuronal regulation in health and disease: the importance of KS-glycodynamics and interactive capability with neuroregulatory ligands. J Neurochem 2019; 149:170-194. [PMID: 30578672 DOI: 10.1111/jnc.14652] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Revised: 11/26/2018] [Accepted: 12/13/2018] [Indexed: 12/18/2022]
Abstract
Compared to the other classes of glycosaminoglycans (GAGs), that is, chondroitin/dermatan sulfate, heparin/heparan sulfate and hyaluronan, keratan sulfate (KS), have the least known of its interactive properties. In the human body, the cornea and the brain are the two most abundant tissue sources of KS. Embryonic KS is synthesized as a linear poly-N-acetyllactosamine chain of d-galactose-GlcNAc repeat disaccharides which become progressively sulfated with development, sulfation of GlcNAc is more predominant than galactose. KS contains multi-sulfated high-charge density, monosulfated and non-sulfated poly-N-acetyllactosamine regions and thus is a heterogeneous molecule in terms of chain length and charge distribution. A recent proteomics study on corneal KS demonstrated its interactivity with members of the Slit-Robbo and Ephrin-Ephrin receptor families and proteins which regulate Rho GTPase signaling and actin polymerization/depolymerization in neural development and differentiation. KS decorates a number of peripheral nervous system/CNS proteoglycan (PG) core proteins. The astrocyte KS-PG abakan defines functional margins of the brain and is up-regulated following trauma. The chondroitin sulfate/KS PG aggrecan forms perineuronal nets which are dynamic neuroprotective structures with anti-oxidant properties and roles in neural differentiation, development and synaptic plasticity. Brain phosphacan a chondroitin sulfate, KS, HNK-1 PG have roles in neural development and repair. The intracellular microtubule and synaptic vesicle KS-PGs MAP1B and SV2 have roles in metabolite transport, storage, and export of neurotransmitters and cytoskeletal assembly. MAP1B has binding sites for tubulin and actin through which it promotes cytoskeletal development in growth cones and is highly expressed during neurite extension. The interactive capability of KS with neuroregulatory ligands indicate varied roles for KS-PGs in development and regenerative neural processes.
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Affiliation(s)
- James Melrose
- Raymond Purves Bone and Joint Research Laboratory, Kolling Institute, St. Leonards, New South Wales, Australia.,Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia.,Sydney Medical School, Northern Campus, Royal North Shore Hospital, The University of Sydney, New South Wales, Australia.,Faculty of Medicine and Health, Royal North Shore Hospital, The University of Sydney, St. Leonards, New South Wales, Australia
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Conte C, Baird MA, Davidson MW, Griffis ER. Spindly is required for rapid migration of human cells. Biol Open 2018; 7:bio.033233. [PMID: 29685992 PMCID: PMC5992534 DOI: 10.1242/bio.033233] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Dynein is the sole processive minus-end-directed microtubule motor found in animals. It has roles in cell division, membrane trafficking, and cell migration. Together with dynactin, dynein regulates centrosomal orientation to establish and maintain cell polarity, controls focal adhesion turnover and anchors microtubules at the leading edge. In higher eukaryotes, dynein/dynactin requires additional components such as Bicaudal D to form an active motor complex and for regulating its cellular localization. Spindly is a protein that targets dynein/dynactin to kinetochores in mitosis and can activate its motility in vitro However, no role for Spindly in interphase dynein/dynactin function has been found. We show that Spindly binds to the cell cortex and microtubule tips and colocalizes with dynein/dynactin at the leading edge of migrating U2OS cells and primary fibroblasts. U2OS cells that lack Spindly migrated slower in 2D than control cells, although centrosome polarization appeared to happen properly in the absence of Spindly. Re-expression of Spindly rescues migration, but the expression of a mutant, which is defective for dynactin binding, failed to rescue this defect. Taken together, these data demonstrate that Spindly plays an important role in mediating a subset of dynein/dynactin's function in cell migration.
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Affiliation(s)
- Claudia Conte
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Michelle A Baird
- Department of Biological Science, National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32306, USA
| | - Michael W Davidson
- Department of Biological Science, National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32306, USA
| | - Eric R Griffis
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
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20
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Heinzen EL, O'Neill AC, Zhu X, Allen AS, Bahlo M, Chelly J, Chen MH, Dobyns WB, Freytag S, Guerrini R, Leventer RJ, Poduri A, Robertson SP, Walsh CA, Zhang M. De novo and inherited private variants in MAP1B in periventricular nodular heterotopia. PLoS Genet 2018; 14:e1007281. [PMID: 29738522 PMCID: PMC5965900 DOI: 10.1371/journal.pgen.1007281] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 05/23/2018] [Accepted: 02/27/2018] [Indexed: 11/19/2022] Open
Abstract
Periventricular nodular heterotopia (PVNH) is a malformation of cortical development commonly associated with epilepsy. We exome sequenced 202 individuals with sporadic PVNH to identify novel genetic risk loci. We first performed a trio-based analysis and identified 219 de novo variants. Although no novel genes were implicated in this initial analysis, PVNH cases were found overall to have a significant excess of nonsynonymous de novo variants in intolerant genes (p = 3.27x10-7), suggesting a role for rare new alleles in genes yet to be associated with the condition. Using a gene-level collapsing analysis comparing cases and controls, we identified a genome-wide significant signal driven by four ultra-rare loss-of-function heterozygous variants in MAP1B, including one de novo variant. In at least one instance, the MAP1B variant was inherited from a parent with previously undiagnosed PVNH. The PVNH was frontally predominant and associated with perisylvian polymicrogyria. These results implicate MAP1B in PVNH. More broadly, our findings suggest that detrimental mutations likely arising in immediately preceding generations with incomplete penetrance may also be responsible for some apparently sporadic diseases.
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Affiliation(s)
- Erin L. Heinzen
- Institute for Genomic Medicine, Columbia University Medical Center, New York, New York, United States of America
- * E-mail: Corresponding author on behalf of the Epi4K Consortium,
| | - Adam C. O'Neill
- Department of Women’s and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Xiaolin Zhu
- Institute for Genomic Medicine, Columbia University Medical Center, New York, New York, United States of America
| | - Andrew S. Allen
- Center for Statistical Genetics and Genomics, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Biostatistics and Bioinformatics, Duke University, Durham, North Carolina, United States of America
| | - Melanie Bahlo
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, School of Mathematics and Statistics, University of Melbourne, Parkville, Victoria, Australia
| | - Jamel Chelly
- Pôle de Biologie, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
- IGBMC, INSERM U964, CNRS UMR 7104, Université de Strasbourg, Illkirch, France
| | - Ming Hui Chen
- Department of Cardiology and Division of Genetics and Genomics, Boston Children’s Hospital, Boston, Massachusetts, United States of America
| | - William B. Dobyns
- Departments of Pediatrics and Neurology, University of Washington, Seattle, Washington, United States of America
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington, United States of America
| | - Saskia Freytag
- Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Renzo Guerrini
- Neuroscience Department, Children's Hospital Anna Meyer-University of Florence, Florence, Italy
| | - Richard J. Leventer
- Department of Neurology Royal Children’s Hospital, University of Melbourne, Parkville, Victoria, Australia
- Murdoch Children’s Research Institute, University of Melbourne, Parkville, Victoria, Australia
- Department of Pediatrics, University of Melbourne, Parkville, Victoria, Australia
| | - Annapurna Poduri
- Department of Neurology, Division of Epilepsy and Clinical Neurophysiology, Boston Children's Hospital, Boston, Massachusetts, United States of America
| | - Stephen P. Robertson
- Department of Women’s and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Christopher A. Walsh
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research and Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- Departments of Pediatrics and Neurology, Harvard Medical School, Boston, Massachusetts, United States of America
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Mengqi Zhang
- Department of Biostatistics and Bioinformatics, Duke University, Durham, North Carolina, United States of America
- Program in Computational Biology and Bioinformatics, Duke University, Durham, NC, United States of America
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21
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Joo EE, Yamada KM. Post-polymerization crosstalk between the actin cytoskeleton and microtubule network. BIOARCHITECTURE 2017; 6:53-9. [PMID: 27058810 DOI: 10.1080/19490992.2016.1171428] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Cellular cytoskeletal systems play many pivotal roles in living organisms by controlling cell shape, division, and migration, which ultimately govern morphology, physiology, and functions of animals. Although the cytoskeletal systems are distinct and play different roles, there is growing evidence that these diverse cytoskeletal systems coordinate their functions with each other. This coordination between cytoskeletal systems, often termed cytoskeletal crosstalk, has been identified when the dynamic state of one individual system affects the other system. In this review, we briefly describe some well-established examples of crosstalk between cytoskeletal systems and then introduce a newly discovered form of crosstalk between the actin cytoskeleton and microtubule network that does not appear to directly alter polymerization or depolymerization of either system. The biological impact and possible significance of this post-polymerization crosstalk between actin and microtubules will be discussed in detail.
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Affiliation(s)
- E Emily Joo
- a Laboratory of Cell and Developmental Biology, National Institute of Dental and Craniofacial Research, National Institutes of Health , Bethesda , MD , USA
| | - Kenneth M Yamada
- a Laboratory of Cell and Developmental Biology, National Institute of Dental and Craniofacial Research, National Institutes of Health , Bethesda , MD , USA
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22
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Ghibaudi M, Boido M, Vercelli A. Functional integration of complex miRNA networks in central and peripheral lesion and axonal regeneration. Prog Neurobiol 2017; 158:69-93. [PMID: 28779869 DOI: 10.1016/j.pneurobio.2017.07.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 07/24/2017] [Accepted: 07/28/2017] [Indexed: 01/06/2023]
Abstract
New players are emerging in the game of peripheral and central nervous system injury since their physiopathological mechanisms remain partially elusive. These mechanisms are characterized by several molecules whose activation and/or modification following a trauma is often controlled at transcriptional level. In this scenario, microRNAs (miRNAs/miRs) have been identified as main actors in coordinating important molecular pathways in nerve or spinal cord injury (SCI). miRNAs are small non-coding RNAs whose functionality at network level is now emerging as a new level of complexity. Indeed they can act as an organized network to provide a precise control of several biological processes. Here we describe the functional synergy of some miRNAs in case of SCI and peripheral damage. In particular we show how several small RNAs can cooperate in influencing simultaneously the molecular pathways orchestrating axon regeneration, inflammation, apoptosis and remyelination. We report about the networks for which miRNA-target bindings have been experimentally demonstrated or inferred based on target prediction data: in both cases, the connection between one miRNA and its downstream pathway is derived from a validated observation or is predicted from the literature. Hence, we discuss the importance of miRNAs in some pathological processes focusing on their functional structure as participating in a cooperative and/or convergence network.
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Affiliation(s)
- M Ghibaudi
- Department of Neuroscience "Rita Levi Montalcini", Neuroscience Institute Cavalieri Ottolenghi, University of Torino, Italian Institute of Neuroscience, Italy.
| | - M Boido
- Department of Neuroscience "Rita Levi Montalcini", Neuroscience Institute Cavalieri Ottolenghi, University of Torino, Italian Institute of Neuroscience, Italy
| | - A Vercelli
- Department of Neuroscience "Rita Levi Montalcini", Neuroscience Institute Cavalieri Ottolenghi, University of Torino, Italian Institute of Neuroscience, Italy
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Rab35 Functions in Axon Elongation Are Regulated by P53-Related Protein Kinase in a Mechanism That Involves Rab35 Protein Degradation and the Microtubule-Associated Protein 1B. J Neurosci 2017; 36:7298-313. [PMID: 27383602 DOI: 10.1523/jneurosci.4064-15.2016] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 05/30/2016] [Indexed: 12/20/2022] Open
Abstract
UNLABELLED Rab35 is a key protein for cargo loading in the recycling endosome. In neuronal immortalized cells, Rab35 promotes neurite differentiation. Here we describe that Rab35 favors axon elongation in rat primary neurons in an activity-dependent manner. In addition, we show that the p53-related protein kinase (PRPK) negatively regulates axonal elongation by reducing Rab35 protein levels through the ubiquitin-proteasome degradation pathway. PRPK-induced Rab35 degradation is regulated by its interaction with microtubule-associated protein 1B (MAP1B), a microtubule stabilizing binding protein essential for axon elongation. Consistently, axon defects found in MAP1B knock-out neurons were reversed by Rab35 overexpression or PRPK inactivation suggesting an epistatic relationship among these proteins. These results define a novel mechanism to support axonal elongation, by which MAP1B prevents PRPK-induced Rab35 degradation. Such a mechanism allows Rab35-mediated axonal elongation and connects the regulation of actin dynamics with membrane trafficking. In addition, our study reveals for the first time that the ubiquitin-proteasome degradation pathway regulates a Rab GTPase. SIGNIFICANCE STATEMENT Rab35 is required for axonal outgrowth. We define that its protein levels are negatively regulated by p53-related protein kinase (PRPK). We show that microtubule-associated protein 1B (MAP1B) interacts with PRPK, preventing PRPK-dependent Rab35 proteasome degradation. We demonstrate that Rab35 regulates Cdc42 activity in neurons. This is the first evidence showing that a Rab protein is regulated by degradation dependent on the ubiquitin-proteasome system.
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Neuronal polarization: From spatiotemporal signaling to cytoskeletal dynamics. Mol Cell Neurosci 2017; 84:11-28. [PMID: 28363876 DOI: 10.1016/j.mcn.2017.03.008] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 03/24/2017] [Accepted: 03/26/2017] [Indexed: 12/20/2022] Open
Abstract
Neuronal polarization establishes distinct molecular structures to generate a single axon and multiple dendrites. Studies over the past years indicate that this efficient separation is brought about by a network of feedback loops. Axonal growth seems to play a major role in fueling those feedback loops and thereby stabilizing neuronal polarity. Indeed, various effectors involved in feedback loops are pivotal for axonal growth by ultimately acting on the actin and microtubule cytoskeleton. These effectors have key roles in interconnecting actin and microtubule dynamics - a mechanism crucial to commanding the growth of axons. We propose a model connecting signaling with cytoskeletal dynamics and neurite growth to better describe the underlying processes involved in neuronal polarization. We will discuss the current views on feedback loops and highlight the current limits of our understanding.
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25
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Portilho DM, Persson R, Arhel N. Role of non-motile microtubule-associated proteins in virus trafficking. Biomol Concepts 2017; 7:283-292. [PMID: 27879481 DOI: 10.1515/bmc-2016-0018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 11/04/2016] [Indexed: 11/15/2022] Open
Abstract
Viruses are entirely dependent on their ability to infect a host cell in order to replicate. To reach their site of replication as rapidly and efficiently as possible following cell entry, many have evolved elaborate mechanisms to hijack the cellular transport machinery to propel themselves across the cytoplasm. Long-range movements have been shown to involve motor proteins along microtubules (MTs) and direct interactions between viral proteins and dynein and/or kinesin motors have been well described. Although less well-characterized, it is also becoming increasingly clear that non-motile microtubule-associated proteins (MAPs), including structural MAPs of the MAP1 and MAP2 families, and microtubule plus-end tracking proteins (+TIPs), can also promote viral trafficking in infected cells, by mediating interaction of viruses with filaments and/or motor proteins, and modulating filament stability. Here we review our current knowledge on non-motile MAPs, their role in the regulation of cytoskeletal dynamics and in viral trafficking during the early steps of infection.
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Abstract
ABSTRACT
Three-dimensional (3D) cell motility underlies essential processes, such as embryonic development, tissue repair and immune surveillance, and is involved in cancer progression. Although the cytoskeleton is a well-studied regulator of cell migration, most of what we know about its functions originates from studies conducted in two-dimensional (2D) cultures. This research established that the microtubule network mediates polarized trafficking and signaling that are crucial for cell shape and movement in 2D. In parallel, developments in light microscopy and 3D cell culture systems progressively allowed to investigate cytoskeletal functions in more physiologically relevant settings. Interestingly, several studies have demonstrated that microtubule involvement in cell morphogenesis and motility can differ in 2D and 3D environments. In this Commentary, we discuss these differences and their relevance for the understanding the role of microtubules in cell migration in vivo. We also provide an overview of microtubule functions that were shown to control cell shape and motility in 3D matrices and discuss how they can be investigated further by using physiologically relevant models.
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Affiliation(s)
- Benjamin P. Bouchet
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, Utrecht 3584 CH, The Netherlands
| | - Anna Akhmanova
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, Utrecht 3584 CH, The Netherlands
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Clark JA, Yeaman EJ, Blizzard CA, Chuckowree JA, Dickson TC. A Case for Microtubule Vulnerability in Amyotrophic Lateral Sclerosis: Altered Dynamics During Disease. Front Cell Neurosci 2016; 10:204. [PMID: 27679561 PMCID: PMC5020100 DOI: 10.3389/fncel.2016.00204] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 08/15/2016] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is an aggressive multifactorial disease converging on a common pathology: the degeneration of motor neurons (MNs), their axons and neuromuscular synapses. This vulnerability and dysfunction of MNs highlights the dependency of these large cells on their intracellular machinery. Neuronal microtubules (MTs) are intracellular structures that facilitate a myriad of vital neuronal functions, including activity dependent axonal transport. In ALS, it is becoming increasingly apparent that MTs are likely to be a critical component of this disease. Not only are disruptions in this intracellular machinery present in the vast majority of seemingly sporadic cases, recent research has revealed that mutation to a microtubule protein, the tubulin isoform TUBA4A, is sufficient to cause a familial, albeit rare, form of disease. In both sporadic and familial disease, studies have provided evidence that microtubule mediated deficits in axonal transport are the tipping point for MN survivability. Axonal transport deficits would lead to abnormal mitochondrial recycling, decreased vesicle and mRNA transport and limited signaling of key survival factors from the neurons peripheral synapses, causing the characteristic peripheral "die back". This disruption to microtubule dependant transport in ALS has been shown to result from alterations in the phenomenon of microtubule dynamic instability: the rapid growth and shrinkage of microtubule polymers. This is accomplished primarily due to aberrant alterations to microtubule associated proteins (MAPs) that regulate microtubule stability. Indeed, the current literature would argue that microtubule stability, particularly alterations in their dynamics, may be the initial driving force behind many familial and sporadic insults in ALS. Pharmacological stabilization of the microtubule network offers an attractive therapeutic strategy in ALS; indeed it has shown promise in many neurological disorders, ALS included. However, the pathophysiological involvement of MTs and their functions is still poorly understood in ALS. Future investigations will hopefully uncover further therapeutic targets that may aid in combating this awful disease.
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Affiliation(s)
- Jayden A Clark
- Menzies Institute for Medical Research, University of Tasmania Hobart, TAS, Australia
| | - Elise J Yeaman
- Menzies Institute for Medical Research, University of Tasmania Hobart, TAS, Australia
| | - Catherine A Blizzard
- Menzies Institute for Medical Research, University of Tasmania Hobart, TAS, Australia
| | - Jyoti A Chuckowree
- Menzies Institute for Medical Research, University of Tasmania Hobart, TAS, Australia
| | - Tracey C Dickson
- Menzies Institute for Medical Research, University of Tasmania Hobart, TAS, Australia
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Epigenetic Repression of CCDC37 and MAP1B Links Chronic Obstructive Pulmonary Disease to Lung Cancer. J Thorac Oncol 2016. [PMID: 26200272 DOI: 10.1097/jto.0000000000000592] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
INTRODUCTION Lung cancer and chronic obstructive pulmonary disease (COPD) share environmental risk factors. COPD also increases the risk of lung cancer; however, the molecular mechanisms are unclear. METHODS An epigenome-wide association study of lung tumors and cancer-free lung tissue (CFLT) pairs from non-small-cell lung cancer cases with (n = 18) or without (n = 17) COPD was conducted using the HumanMethylation450 beadchip (HM450K). COPD-associated methylation of top-ranked genes was confirmed in a larger sample set, independently validated, and their potential as sputum-based biomarkers was investigated. RESULTS Methylation of CCDC37 and MAP1B was more prevalent in lung tumors from COPD than non-COPD cases [54 of 71 (76%) versus 20 of 46 (43%), p = 0.0013] and [48 of 71 (68%) versus 17 of 46 (37%), p = 0.0035], respectively, after adjustment for age, sex, smoking status, and tumor histology. HM450K probes across CCDC37 and MAP1B promoters showed higher methylation in tumors than CFLT with the highest methylation seen in tumors from COPD cases (p < 0.05). These results were independently validated using The Cancer Genome Atlas data. CCDC37 methylation was more prevalent in sputum from COPD than non-COPD smokers (p < 0.005) from two cohorts. CCDC37 and MAP1B expression was dramatically repressed in tumors and CFLT from COPD than non-COPD cases, p less than 0.02. CONCLUSIONS The reduced expression of CCDC37 and MAP1B associated with COPD likely predisposes these genes to methylation that in turn, may contribute to lung cancer.
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Rozés Salvador V, Heredia F, Berardo A, Palandri A, Wojnacki J, Vivinetto AL, Sheikh KA, Caceres A, Lopez PHH. Anti-glycan antibodies halt axon regeneration in a model of Guillain Barrè Syndrome axonal neuropathy by inducing microtubule disorganization via RhoA-ROCK-dependent inactivation of CRMP-2. Exp Neurol 2016; 278:42-53. [PMID: 26804001 DOI: 10.1016/j.expneurol.2016.01.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 01/19/2016] [Indexed: 10/22/2022]
Abstract
Several reports have linked the presence of high titers of anti-Gg Abs with delayed recovery/poor prognosis in GBS. In most cases, failure to recover is associated with halted/deficient axon regeneration. Previous work identified that monoclonal and patient-derived anti-Gg Abs can act as inhibitory factors in an animal model of axon regeneration. Further studies using primary dorsal root ganglion neuron (DRGn) cultures demonstrated that anti-Gg Abs can inhibit neurite outgrowth by targeting gangliosides via activation of the small GTPase RhoA and its associated kinase (ROCK), a signaling pathway common to other established inhibitors of axon regeneration. We aimed to study the molecular basis of the inhibitory effect of anti-Gg abs on neurite outgrowth by dissecting the molecular dynamics of growth cones (GC) cytoskeleton in relation to the spatial-temporal analysis of RhoA activity. We now report that axon growth inhibition in DRGn induced by a well characterized mAb targeting gangliosides GD1a/GT1b involves: i) an early RhoA/ROCK-independent collapse of lamellipodia; ii) a RhoA/ROCK-dependent shrinking of filopodia; and iii) alteration of GC microtubule organization/and presumably dynamics via RhoA/ROCK-dependent phosphorylation of CRMP-2 at threonine 555. Our results also show that mAb 1B7 inhibits peripheral axon regeneration in an animal model via phosphorylation/inactivation of CRMP-2 at threonine 555. Overall, our data may help to explain the molecular mechanisms underlying impaired nerve repair in GBS. Future work should define RhoA-independent pathway/s and effectors regulating actin cytoskeleton, thus providing an opportunity for the design of a successful therapy to guarantee an efficient target reinnervation.
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Affiliation(s)
- Victoria Rozés Salvador
- Laboratory of Neurobiology, Instituto de Investigación Médica Mercedes y Martin Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Argentina
| | - Florencia Heredia
- Laboratory of Neurobiology, Instituto de Investigación Médica Mercedes y Martin Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Argentina
| | - Andrés Berardo
- Laboratory of Neurobiology, Instituto de Investigación Médica Mercedes y Martin Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Argentina
| | - Anabela Palandri
- Laboratory of Neurobiology, Instituto de Investigación Médica Mercedes y Martin Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Argentina
| | - Jose Wojnacki
- Laboratory of Neurobiology, Instituto de Investigación Médica Mercedes y Martin Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Argentina
| | - Ana L Vivinetto
- Laboratory of Neurobiology, Instituto de Investigación Médica Mercedes y Martin Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Argentina
| | - Kazim A Sheikh
- Department of Neurology, University of Texas Medical School at Houston, Houston, USA
| | - Alfredo Caceres
- Laboratory of Neurobiology, Instituto de Investigación Médica Mercedes y Martin Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Argentina
| | - Pablo H H Lopez
- Laboratory of Neurobiology, Instituto de Investigación Médica Mercedes y Martin Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Argentina; Facultad de Psicología, Universidad Nacional de Córdoba, Argentina.
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Jayachandran P, Olmo VN, Sanchez SP, McFarland RJ, Vital E, Werner JM, Hong E, Sanchez-Alberola N, Molodstov A, Brewster RM. Microtubule-associated protein 1b is required for shaping the neural tube. Neural Dev 2016; 11:1. [PMID: 26782621 PMCID: PMC4717579 DOI: 10.1186/s13064-015-0056-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 12/29/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Shaping of the neural tube, the precursor of the brain and spinal cord, involves narrowing and elongation of the neural tissue, concomitantly with other morphogenetic changes that contribue to this process. In zebrafish, medial displacement of neural cells (neural convergence or NC), which drives the infolding and narrowing of the neural ectoderm, is mediated by polarized migration and cell elongation towards the dorsal midline. Failure to undergo proper NC results in severe neural tube defects, yet the molecular underpinnings of this process remain poorly understood. RESULTS We investigated here the role of the microtubule (MT) cytoskeleton in mediating NC in zebrafish embryos using the MT destabilizing and hyperstabilizing drugs nocodazole and paclitaxel respectively. We found that MTs undergo major changes in organization and stability during neurulation and are required for the timely completion of NC by promoting cell elongation and polarity. We next examined the role of Microtubule-associated protein 1B (Map1b), previously shown to promote MT dynamicity in axons. map1b is expressed earlier than previously reported, in the developing neural tube and underlying mesoderm. Loss of Map1b function using morpholinos (MOs) or δMap1b (encoding a truncated Map1b protein product) resulted in delayed NC and duplication of the neural tube, a defect associated with impaired NC. We observed a loss of stable MTs in these embryos that is likely to contribute to the NC defect. Lastly, we found that Map1b mediates cell elongation in a cell autonomous manner and polarized protrusive activity, two cell behaviors that underlie NC and are MT-dependent. CONCLUSIONS Together, these data highlight the importance of MTs in the early morphogenetic movements that shape the neural tube and reveal a novel role for the MT regulator Map1b in mediating cell elongation and polarized cell movement in neural progenitor cells.
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Affiliation(s)
- Pradeepa Jayachandran
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD, USA.
| | - Valerie N Olmo
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD, USA.
| | - Stephanie P Sanchez
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD, USA.
| | - Rebecca J McFarland
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD, USA.
| | - Eudorah Vital
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD, USA.
| | - Jonathan M Werner
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD, USA.
| | - Elim Hong
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD, USA. .,Institut de Biologie Paris Seine-Laboratoire Neuroscience Paris Seine INSERM UMRS 1130, CNRS UMR 8246, UPMC UM 118 Université Pierre et Marie Curie, Paris, France.
| | - Neus Sanchez-Alberola
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD, USA.
| | - Aleksey Molodstov
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD, USA.
| | - Rachel M Brewster
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD, USA.
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31
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Wang B, Pan L, Wei M, Wang Q, Liu WW, Wang N, Jiang XY, Zhang X, Bao L. FMRP-Mediated Axonal Delivery of miR-181d Regulates Axon Elongation by Locally Targeting Map1b and Calm1. Cell Rep 2015; 13:2794-807. [DOI: 10.1016/j.celrep.2015.11.057] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 10/15/2015] [Accepted: 11/17/2015] [Indexed: 01/04/2023] Open
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Chen X, Zhou X, Mao TC, Shi XH, Fan DL, Zhang YM. Effect of microtubule-associated protein-4 on epidermal cell migration under different oxygen concentrations. J Dermatol 2015; 43:674-81. [PMID: 26602869 DOI: 10.1111/1346-8138.13192] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 09/25/2015] [Indexed: 11/30/2022]
Abstract
After skin trauma, regional epidermal cell migration mediates the re-epithelialization of the wound surface, which is an important step for wound healing, yet the underlying molecular regulatory mechanism is unclear. In the current study, HaCaT cells were maintained under different oxygen concentrations (1%, 21%, 40% and 65%). Technologies including immunofluorescence staining, wound scratch, transwell invasion, western blot and low-expression lentiviral vector were utilized to observe the changes in microtubule dynamics and the microtubule-associated protein (MAP)4 expression. MAP4's effect on cell migration under different oxygen concentrations was also studied. The results showed that under hyperoxic (40% and 65%) and hypoxic (1%) conditions, HaCaT cells were able to regulate cell microtubule dynamics by MAP4, thus promoting cell migration. On the other hand, MAP4 silencing through targeted shRNA attenuated HaCaT cell migration under the above oxygen concentrations. These results imply that MAP4 plays an important role in epidermal cell migration under different oxygen concentrations.
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Affiliation(s)
- Xin Chen
- Department of Plastic and Cosmetic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Xin Zhou
- Department of Plastic and Cosmetic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Tong-Chun Mao
- Department of Plastic and Cosmetic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Xiao-Hua Shi
- Department of Plastic and Cosmetic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Dong-Li Fan
- Department of Plastic and Cosmetic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Yi-Ming Zhang
- Department of Plastic and Cosmetic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
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Exchange Protein Directly Activated by cAMP (EPAC) Regulates Neuronal Polarization through Rap1B. J Neurosci 2015; 35:11315-29. [PMID: 26269639 DOI: 10.1523/jneurosci.3645-14.2015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
UNLABELLED Acquisition of neuronal polarity is a complex process involving cellular and molecular events. The second messenger cAMP is involved in axonal specification through activation of protein kinase A. However, an alternative cAMP-dependent mechanism involves the exchange protein directly activated by cAMP (EPAC), which also responds to physiological changes in cAMP concentration, promoting activation of the small Rap GTPases. Here, we present evidence that EPAC signaling contributes to axon specification and elongation. In primary rat hippocampal neurons, EPAC isoforms were expressed differentially during axon specification. Furthermore, 8-pCPT, an EPAC pharmacological activator, and genetic manipulations of EPAC in neurons induced supernumerary axons indicative of Rap1b activation. Moreover, 8-pCPT-treated neurons expressed ankyrin G and other markers of mature axons such as synaptophysin and axonal accumulation of vGLUT1. In contrast, pharmacological inhibition of EPAC delayed neuronal polarity. Genetic manipulations to inactivate EPAC1 using either shRNA or neurons derived from EPAC1 knock-out (KO) mice led to axon elongation and polarization defects. Interestingly, multiaxonic neurons generated by 8-pCPT treatments in wild-type neurons were not found in EPAC1 KO mice neurons. Altogether, these results propose that EPAC signaling is an alternative and complementary mechanism for cAMP-dependent axon determination. SIGNIFICANCE STATEMENT This study identifies the guanine exchange factor responsible for Rap1b activation during neuronal polarization and provides an alternate explanation for cAMP-dependent acquisition of neuronal polarity.
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Nakashima H, Okimura C, Iwadate Y. The molecular dynamics of crawling migration in microtubule-disrupted keratocytes. Biophys Physicobiol 2015; 12:21-9. [PMID: 27493851 PMCID: PMC4736841 DOI: 10.2142/biophysico.12.0_21] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 07/24/2015] [Indexed: 12/21/2022] Open
Abstract
Cell-crawling migration plays an essential role in complex biological phenomena. It is now generally believed that many processes essential to such migration are regulated by microtubules in many cells, including fibroblasts and neurons. However, keratocytes treated with nocodazole, which is an inhibitor of microtubule polymerization – and even keratocyte fragments that contain no microtubules – migrate at the same velocity and with the same directionality as normal keratocytes. In this study, we discovered that not only these migration properties, but also the molecular dynamics that regulate such properties, such as the retrograde flow rate of actin filaments, distributions of vinculin and myosin II, and traction forces, are also the same in nocodazole-treated keratocytes as those in untreated keratocytes. These results suggest that microtubules are not in fact required for crawling migration of keratocytes, either in terms of migrating properties or of intracellular molecular dynamics.
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Affiliation(s)
- Hitomi Nakashima
- Faculty of Science, Yamaguchi University, Yamaguchi 753-8512, Japan
| | - Chika Okimura
- Faculty of Science, Yamaguchi University, Yamaguchi 753-8512, Japan
| | - Yoshiaki Iwadate
- Faculty of Science, Yamaguchi University, Yamaguchi 753-8512, Japan
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35
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Ketschek A, Jones S, Spillane M, Korobova F, Svitkina T, Gallo G. Nerve growth factor promotes reorganization of the axonal microtubule array at sites of axon collateral branching. Dev Neurobiol 2015; 75:1441-61. [PMID: 25846486 DOI: 10.1002/dneu.22294] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 03/13/2015] [Accepted: 03/30/2015] [Indexed: 12/31/2022]
Abstract
The localized debundling of the axonal microtubule array and the entry of microtubules into axonal filopodia are two defining features of collateral branching. We report that nerve growth factor (NGF), a branch-inducing signal, increases the frequency of microtubule debundling along the axon shaft of chicken embryonic sensory neurons. Sites of debundling correlate strongly with the localized targeting of microtubules into filopodia. Platinum replica electron microscopy suggests physical interactions between debundled microtubules and axonal actin filaments. However, as evidenced by depolymerization of actin filaments and inhibition of myosin II, actomyosin force generation does not promote debundling. In contrast, loss of actin filaments or inhibition of myosin II activity promotes debundling, indicating that axonal actomyosin forces suppress debundling. MAP1B is a microtubule associated protein that represses axon branching. Following treatment with NGF, microtubules penetrating filopodia during the early stages of branching exhibited lower levels of associated MAP1B. NGF increased and decreased the levels of MAP1B phosphorylated at a GSK-3β site (pMAP1B) along the axon shaft and within axonal filopodia, respectively. The levels of MAP1B and pMAP1B were not altered at sites of debundling, relative to the rest of the axon. Unlike the previously determined effects of NGF on the axonal actin cytoskeleton, the effects of NGF on microtubule debundling were not affected by inhibition of protein synthesis. Collectively, these data indicate that NGF promotes localized axonal microtubule debundling, that actomyosin forces antagonize microtubule debundling, and that NGF regulates pMAP1B in axonal filopodia during the early stages of collateral branch formation.
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Affiliation(s)
- Andrea Ketschek
- Department of Anatomy and Cell Biology, Shriners Hospitals Pediatric Research Center, Temple University, Philadelphia, Pennsylvania, 19140
| | - Steven Jones
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, 19104
| | - Mirela Spillane
- Department of Anatomy and Cell Biology, Shriners Hospitals Pediatric Research Center, Temple University, Philadelphia, Pennsylvania, 19140
| | - Farida Korobova
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, 19104
| | - Tatyana Svitkina
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, 19104
| | - Gianluca Gallo
- Department of Anatomy and Cell Biology, Shriners Hospitals Pediatric Research Center, Temple University, Philadelphia, Pennsylvania, 19140
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Yang M, Wu M, Xia P, Wang C, Yan P, Gao Q, Liu J, Wang H, Duan X, Yang X. The role of microtubule-associated protein 1B in axonal growth and neuronal migration in the central nervous system. Neural Regen Res 2015; 7:842-8. [PMID: 25737712 PMCID: PMC4342712 DOI: 10.3969/j.issn.1673-5374.2012.11.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Accepted: 03/08/2012] [Indexed: 01/22/2023] Open
Abstract
In this review, we discuss the role of microtubule-associated protein 1B (MAP1B) and its phosphorylation in axonal development and regeneration in the central nervous system. MAP1B exhibits similar functions during axonal development and regeneration. MAP1B and phosphorylated MAP1B in neurons and axons maintain a dynamic balance between cytoskeletal components, and regulate the stability and interaction of microtubules and actin to promote axonal growth, neural connectivity and regeneration in the central nervous system.
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Affiliation(s)
- Maoguang Yang
- Department of Orthopedics, China-Japan Union Hospital, Jilin University, Changchun 130033, Jilin Province, China
| | - Minfei Wu
- Department of Orthopedics, China-Japan Union Hospital, Jilin University, Changchun 130033, Jilin Province, China
| | - Peng Xia
- Department of Orthopedics, China-Japan Union Hospital, Jilin University, Changchun 130033, Jilin Province, China
| | - Chunxin Wang
- Department of Orthopedics, China-Japan Union Hospital, Jilin University, Changchun 130033, Jilin Province, China
| | - Peng Yan
- Department of Orthopedics, China-Japan Union Hospital, Jilin University, Changchun 130033, Jilin Province, China
| | - Qi Gao
- Department of Orthopedics, China-Japan Union Hospital, Jilin University, Changchun 130033, Jilin Province, China
| | - Jian Liu
- Department of Orthopedics, China-Japan Union Hospital, Jilin University, Changchun 130033, Jilin Province, China
| | - Haitao Wang
- Department of Orthopedics, China-Japan Union Hospital, Jilin University, Changchun 130033, Jilin Province, China
| | - Xingwei Duan
- Department of Orthopedics, China-Japan Union Hospital, Jilin University, Changchun 130033, Jilin Province, China
| | - Xiaoyu Yang
- Department of Orthopedics, China-Japan Union Hospital, Jilin University, Changchun 130033, Jilin Province, China
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A presynaptic role of microtubule-associated protein 1/Futsch in Drosophila: regulation of active zone number and neurotransmitter release. J Neurosci 2014; 34:6759-71. [PMID: 24828631 DOI: 10.1523/jneurosci.4282-13.2014] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Structural microtubule-associated proteins (MAPs), like MAP1, not only control the stability of microtubules, but also interact with postsynaptic proteins in the nervous system. Their presynaptic role has barely been studied. To tackle this question, we used the Drosophila model in which there is only one MAP1 homolog: Futsch, which is expressed at the larval neuromuscular junction, presynaptically only. We show that Futsch regulates neurotransmitter release and active zone density. Importantly, we provide evidence that this role of Futsch is not just the consequence of its microtubule-stabilizing function. Using high-resolution microscopy, we show that Futsch and microtubules are almost systematically present in close proximity to active zones, with Futsch being localized in-between microtubules and active zones. Using proximity ligation assays, we further demonstrate the proximity of Futsch, but not microtubules, to active zone components. Altogether our data are in favor of a model by which Futsch locally stabilizes active zones, by reinforcing their link with the underlying microtubule cytoskeleton.
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38
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Llorens-Martín M, Jurado J, Hernández F, Avila J. GSK-3β, a pivotal kinase in Alzheimer disease. Front Mol Neurosci 2014; 7:46. [PMID: 24904272 PMCID: PMC4033045 DOI: 10.3389/fnmol.2014.00046] [Citation(s) in RCA: 225] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 05/02/2014] [Indexed: 01/10/2023] Open
Abstract
Alzheimer disease (AD) is the most common form of age-related dementia. The etiology of AD is considered to be multifactorial as only a negligible percentage of cases have a familial or genetic origin. Glycogen synthase kinase-3 (GSK-3) is regarded as a critical molecular link between the two histopathological hallmarks of the disease, namely senile plaques and neurofibrillary tangles. In this review, we summarize current data regarding the involvement of this kinase in several aspects of AD development and progression, as well as key observations highlighting GSK-3 as one of the most relevant targets for AD treatment.
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Affiliation(s)
| | - Jerónimo Jurado
- Centro de Biología Molecular "Severo Ochoa", Consejo Superior de Investigaciones Cientificas, Universidad Autónoma de Madrid Madrid, Spain ; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Instituto de Salud Carlos III Madrid, Spain
| | - Félix Hernández
- Centro de Biología Molecular "Severo Ochoa", Consejo Superior de Investigaciones Cientificas, Universidad Autónoma de Madrid Madrid, Spain ; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Instituto de Salud Carlos III Madrid, Spain ; Biology Faculty, Autónoma University Madrid, Spain
| | - Jesús Avila
- Centro de Biología Molecular "Severo Ochoa", Consejo Superior de Investigaciones Cientificas, Universidad Autónoma de Madrid Madrid, Spain ; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Instituto de Salud Carlos III Madrid, Spain
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Villarroel-Campos D, Gonzalez-Billault C. The MAP1B case: an old MAP that is new again. Dev Neurobiol 2014; 74:953-71. [PMID: 24700609 DOI: 10.1002/dneu.22178] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 03/27/2014] [Accepted: 03/31/2014] [Indexed: 12/24/2022]
Abstract
The functions of microtubule-associated protein 1B (MAP1B) have historically been linked to the development of the nervous system, based on its very early expression in neurons and glial cells. Moreover, mice in which MAP1B is genetically inactivated have been used extensively to show its role in axonal elongation, neuronal migration, and axonal guidance. In the last few years, it has become apparent that MAP1B has other cellular and molecular functions that are not related to its microtubule-stabilizing properties in the embryonic and adult brain. In this review, we present a systematic review of the canonical and novel functions of MAP1B and propose that, in addition to regulating the polymerization of microtubule and actin microfilaments, MAP1B also acts as a signaling protein involved in normal physiology and pathological conditions in the nervous system.
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Affiliation(s)
- David Villarroel-Campos
- Laboratory of Cell and Neuronal Dynamics (Cenedyn), Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile
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40
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Joo EE, Yamada KM. MYPT1 regulates contractility and microtubule acetylation to modulate integrin adhesions and matrix assembly. Nat Commun 2014; 5:3510. [PMID: 24667306 DOI: 10.1038/ncomms4510] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 02/25/2014] [Indexed: 01/16/2023] Open
Abstract
Although much is known about how individual cytoskeletal systems contribute to physiological processes such as cell migration and branching morphogenesis, little is known about how these different systems actively coordinate their functions after polymerization. Here we show that both fibroblasts and developing glands reciprocally coordinate levels of cellular contractility and microtubule acetylation. We find that this balance is achieved by interaction of the myosin phosphatase target subunit of myosin phosphatase with either myosin light chain or HDAC6, a microtubule deacetylase. This balance of contractility and microtubule acetylation controls progression of adhesion maturation by regulating surface density of α5β1 integrin and fibronectin. Thus, we propose that a homeostatic balance between contractility and microtubule acetylation is mediated by myosin phosphatase via controlled activation and deactivation of myosin II and HDAC6. This regulates the surface density of α5β1 integrin to modulate fibronectin matrix assembly and governs rates of cell migration and branching morphogenesis.
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Affiliation(s)
- E Emily Joo
- Laboratory of Cell and Developmental Biology, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Kenneth M Yamada
- Laboratory of Cell and Developmental Biology, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland 20892, USA
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41
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Wojnacki J, Quassollo G, Marzolo MP, Cáceres A. Rho GTPases at the crossroad of signaling networks in mammals: impact of Rho-GTPases on microtubule organization and dynamics. Small GTPases 2014; 5:e28430. [PMID: 24691223 DOI: 10.4161/sgtp.28430] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Microtubule (MT) organization and dynamics downstream of external cues is crucial for maintaining cellular architecture and the generation of cell asymmetries. In interphase cells RhoA, Rac, and Cdc42, conspicuous members of the family of small Rho GTPases, have major roles in modulating MT stability, and hence polarized cell behaviors. However, MTs are not mere targets of Rho GTPases, but also serve as signaling platforms coupling MT dynamics to Rho GTPase activation in a variety of cellular conditions. In this article, we review some of the key studies describing the reciprocal relationship between small Rho-GTPases and MTs during migration and polarization.
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Affiliation(s)
- José Wojnacki
- Laboratory of Neurobiology; Instituto Mercedes y Martin Ferreyra (INIMEC) CONICET; Córdoba, Argentina
| | - Gonzalo Quassollo
- Laboratory of Neurobiology; Instituto Mercedes y Martin Ferreyra (INIMEC) CONICET; Córdoba, Argentina
| | - María-Paz Marzolo
- Laboratorio de Tráfico Intracelular y Señalización; Departamento de Biología Celular y Molecular; Facultad de Ciencias Biológicas; Pontificia Universidad Católica de Chile; Santiago, Chile
| | - Alfredo Cáceres
- Laboratory of Neurobiology; Instituto Mercedes y Martin Ferreyra (INIMEC) CONICET; Córdoba, Argentina; Universidad Nacional Córdoba (UNC); Córdoba, Argentina; Instituto Universitario Ciencias Biomédicas Córdoba (IUCBC); Córdoba-Argentina
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Tivodar S, Kalemaki K, Kounoupa Z, Vidaki M, Theodorakis K, Denaxa M, Kessaris N, de Curtis I, Pachnis V, Karagogeos D. Rac-GTPases Regulate Microtubule Stability and Axon Growth of Cortical GABAergic Interneurons. Cereb Cortex 2014; 25:2370-82. [PMID: 24626607 PMCID: PMC4537417 DOI: 10.1093/cercor/bhu037] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Cortical interneurons are characterized by extraordinary functional and morphological diversity. Although tremendous progress has been made in uncovering molecular and cellular mechanisms implicated in interneuron generation and function, several questions still remain open. Rho-GTPases have been implicated as intracellular mediators of numerous developmental processes such as cytoskeleton organization, vesicle trafficking, transcription, cell cycle progression, and apoptosis. Specifically in cortical interneurons, we have recently shown a cell-autonomous and stage-specific requirement for Rac1 activity within proliferating interneuron precursors. Conditional ablation of Rac1 in the medial ganglionic eminence leads to a 50% reduction of GABAergic interneurons in the postnatal cortex. Here we examine the additional role of Rac3 by analyzing Rac1/Rac3 double-mutant mice. We show that in the absence of both Rac proteins, the embryonic migration of medial ganglionic eminence-derived interneurons is further impaired. Postnatally, double-mutant mice display a dramatic loss of cortical interneurons. In addition, Rac1/Rac3-deficient interneurons show gross cytoskeletal defects in vitro, with the length of their leading processes significantly reduced and a clear multipolar morphology. We propose that in the absence of Rac1/Rac3, cortical interneurons fail to migrate tangentially towards the pallium due to defects in actin and microtubule cytoskeletal dynamics.
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Affiliation(s)
- Simona Tivodar
- Institute of Molecular Biology and Biotechnology (IMBB, FORTH), Heraklion, Greece Department of Basic Science, Faculty of Medicine, University of Crete, Heraklion, Greece
| | - Katerina Kalemaki
- Institute of Molecular Biology and Biotechnology (IMBB, FORTH), Heraklion, Greece Department of Basic Science, Faculty of Medicine, University of Crete, Heraklion, Greece
| | - Zouzana Kounoupa
- Institute of Molecular Biology and Biotechnology (IMBB, FORTH), Heraklion, Greece Department of Basic Science, Faculty of Medicine, University of Crete, Heraklion, Greece
| | - Marina Vidaki
- Institute of Molecular Biology and Biotechnology (IMBB, FORTH), Heraklion, Greece Department of Basic Science, Faculty of Medicine, University of Crete, Heraklion, Greece Current Address: Koch Institute for Integrative Cancer Research at MIT, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Kostas Theodorakis
- Institute of Molecular Biology and Biotechnology (IMBB, FORTH), Heraklion, Greece Department of Basic Science, Faculty of Medicine, University of Crete, Heraklion, Greece
| | - Myrto Denaxa
- Division of Molecular Neurobiology, Medical Research Council, National Institute for Medical Research, London, UK
| | - Nicoletta Kessaris
- Wolfson Institute for Biomedical Research and Department of Cell and Developmental Biology, University College London, UK
| | - Ivan de Curtis
- Cell Adhesion Unit, Dibit, San Raffaele Scientific Institute, 20132 Milano, Italy
| | - Vassilis Pachnis
- Division of Molecular Neurobiology, Medical Research Council, National Institute for Medical Research, London, UK
| | - Domna Karagogeos
- Institute of Molecular Biology and Biotechnology (IMBB, FORTH), Heraklion, Greece Department of Basic Science, Faculty of Medicine, University of Crete, Heraklion, Greece
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43
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The guanine nucleotide exchange factor Tiam1: A Janus-faced molecule in cellular signaling. Cell Signal 2014; 26:483-91. [DOI: 10.1016/j.cellsig.2013.11.034] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 11/26/2013] [Indexed: 11/22/2022]
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Gandini MA, Henríquez DR, Grimaldo L, Sandoval A, Altier C, Zamponi GW, Felix R, González-Billault C. CaV2.2 channel cell surface expression is regulated by the light chain 1 (LC1) of the microtubule-associated protein B (MAP1B) via UBE2L3-mediated ubiquitination and degradation. Pflugers Arch 2014; 466:2113-26. [PMID: 24566975 DOI: 10.1007/s00424-014-1476-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 02/05/2014] [Accepted: 02/07/2014] [Indexed: 12/18/2022]
Abstract
Microtubule-associated protein B is a cytoskeleton protein consisting of heavy and light (LC) chains that play important roles in the regulation of neuronal morphogenesis and function. LC1 is also well known to interact with diverse ionotropic receptors at postsynapse. Much less is known, however, regarding the role of LC1 at presynaptic level where voltage-gated N-type Ca(2+) channels couple membrane depolarization to neurotransmitter release. Here, we investigated whether LC1 interacts with the N-type channels. Co-localization analysis revealed spatial proximity of the two proteins in hippocampal neurons. The interaction between LC1 and the N-type channel was demonstrated using co-immunoprecipitation experiments and in vitro pull-down assays. Detailed biochemical analysis suggested that the interaction occurs through the N-terminal of LC1 and the C-terminal of the pore-forming CaVα1 subunit of the channels. Patch-clamp studies in HEK-293 cells revealed a significant decrease in N-type currents upon LC1 expression, without apparent changes in kinetics. Recordings performed in the presence of MG132 prevented the actions of LC1 suggesting enhanced channel proteasomal degradation. Interestingly, using the yeast two-hybrid system and immunoprecipitation assays in HEK-293 cells, we revealed an interaction between LC1 and the ubiquitin-conjugating enzyme UBE2L3. Furthermore, we found that the LC1/UBE2L3 complex could interact with the N-type channels, suggesting that LC1 may act as a scaffold protein to increase UBE2L3-mediated channel ubiquitination. Together these results revealed a novel functional coupling between LC1 and the N-type channels.
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Affiliation(s)
- María A Gandini
- Department of Cell Biology, Center for Research and Advanced Studies of the National Polytechnic Institute, (Cinvestav-IPN), Avenida IPN 2508, Colonia Zacatenco, Mexico DF, 07360, Mexico
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Dent EW, Baas PW. Microtubules in neurons as information carriers. J Neurochem 2013; 129:235-9. [PMID: 24266899 DOI: 10.1111/jnc.12621] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2013] [Revised: 10/23/2013] [Accepted: 11/20/2013] [Indexed: 11/28/2022]
Abstract
Microtubules in neurons consist of highly dynamic regions as well as stable regions, some of which persist after bouts of severing as short mobile polymers. Concentrated at the plus ends of the highly dynamic regions are microtubule plus end tracking proteins called +TIPs that can interact with an array of other proteins and structures relevant to the plasticity of the neuron. It is also provocative to ponder that short mobile microtubules might similarly convey information with them as they transit within the neuron. Thus, beyond their known conventional functions in supporting neuronal architecture and organelle transport, microtubules may act as 'information carriers' in the neuron.
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Affiliation(s)
- Erik W Dent
- Department of Neuroscience, University of Wisconsin, School of Medicine and Public Health, 1300 University Avenue, Madison, WI, USA
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Slater PG, Ramirez VT, Gonzalez-Billault C, Varela-Nallar L, Inestrosa NC. Frizzled-5 receptor is involved in neuronal polarity and morphogenesis of hippocampal neurons. PLoS One 2013; 8:e78892. [PMID: 24205342 PMCID: PMC3800132 DOI: 10.1371/journal.pone.0078892] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Accepted: 09/17/2013] [Indexed: 01/09/2023] Open
Abstract
The Wnt signaling pathway plays important roles during different stages of neuronal development, including neuronal polarization and dendritic and axonal outgrowth. However, little is known about the identity of the Frizzled receptors mediating these processes. In the present study, we investigated the role of Frizzled-5 (Fzd5) on neuronal development in cultured Sprague-Dawley rat hippocampal neurons. We found that Fzd5 is expressed early in cultured neurons on actin-rich structures localized at minor neurites and axonal growth cones. At 4 DIV, Fzd5 polarizes towards the axon, where its expression is detected mainly at the peripheral zone of axonal growth cones, with no obvious staining at dendrites; suggesting a role of Fzd5 in neuronal polarization. Overexpression of Fzd5 during the acquisition of neuronal polarity induces mislocalization of the receptor and a loss of polarized axonal markers. Fzd5 knock-down leads to loss of axonal proteins, suggesting an impaired neuronal polarity. In contrast, overexpression of Fzd5 in neurons that are already polarized did not alter polarity, but decreased the total length of axons and increased total dendrite length and arborization. Fzd5 activated JNK in HEK293 cells and the effects triggered by Fzd5 overexpression in neurons were partially prevented by inhibition of JNK, suggesting that a non-canonical Wnt signaling mechanism might be involved. Our results suggest that, Fzd5 has a role in the establishment of neuronal polarity, and in the morphogenesis of neuronal processes, in part through the activation of the non-canonical Wnt mechanism involving JNK.
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Affiliation(s)
- Paula G. Slater
- Centro de Envejecimiento y Regeneración (CARE), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Santiago, Chile
| | - Valerie T. Ramirez
- Centro de Envejecimiento y Regeneración (CARE), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Santiago, Chile
| | | | - Lorena Varela-Nallar
- Centro de Envejecimiento y Regeneración (CARE), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Santiago, Chile
| | - Nibaldo C. Inestrosa
- Centro de Envejecimiento y Regeneración (CARE), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Santiago, Chile
- * . E-mail:
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Cheung HNM, Dunbar C, Mórotz GM, Cheng WH, Chan HYE, Miller CCJ, Lau KF. FE65 interacts with ADP-ribosylation factor 6 to promote neurite outgrowth. FASEB J 2013; 28:337-49. [PMID: 24056087 DOI: 10.1096/fj.13-232694] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
FE65 is an adaptor protein that binds to the amyloid precursor protein (APP). As such, FE65 has been implicated in the pathogenesis of Alzheimer's disease. In addition, evidence suggests that FE65 is involved in brain development. It is generally believed that FE65 participates in these processes by recruiting various interacting partners to form functional complexes. Here, we show that via its first phosphotyrosine binding (PTB) domain, FE65 binds to the small GTPase ADP-ribosylation factor 6 (ARF6). FE65 preferentially binds to ARF6-GDP, and they colocalize in neuronal growth cones. Interestingly, FE65 stimulates the activation of both ARF6 and its downstream GTPase Rac1, a regulator of actin dynamics, and functions in growth cones to stimulate neurite outgrowth. We show that transfection of FE65 and/or ARF6 promotes whereas small interfering RNA knockdown of FE65 or ARF6 inhibits neurite outgrowth in cultured neurons as compared to the mock-transfected control cells. Moreover, knockdown of ARF6 attenuates FE65 stimulation of neurite outgrowth and defective neurite outgrowth seen in FE65-deficient neurons is partially corrected by ARF6 overexpression. Notably, the stimulatory effect of FE65 and ARF6 on neurite outgrowth is abrogated either by dominant-negative Rac1 or knockdown of Rac1. Thus, we identify FE65 as a novel regulator of neurite outgrowth via controlling ARF6-Rac1 signaling.
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Affiliation(s)
- Hei Nga Maggie Cheung
- 1School of Life Sciences, Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR, China.
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Subramanian N, Navaneethakrishnan S, Biswas J, Kanwar RK, Kanwar JR, Krishnakumar S. RNAi mediated Tiam1 gene knockdown inhibits invasion of retinoblastoma. PLoS One 2013; 8:e70422. [PMID: 23950931 PMCID: PMC3737373 DOI: 10.1371/journal.pone.0070422] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Accepted: 06/18/2013] [Indexed: 11/18/2022] Open
Abstract
T lymphoma invasion and metastasis protein (Tiam1) is up-regulated in variety of cancers and its expression level is related to metastatic potential of the type of cancer. Earlier, Tiam1 was shown to be overexpressed in retinoblastoma (RB) and we hypothesized that it was involved in invasiveness of RB. This was tested by silencing Tiam1 in RB cell lines (Y79 and Weri-Rb1) using siRNA pool, targeting different regions of Tiam1 mRNA. The cDNA microarray of Tiam1 silenced cells showed gene regulations altered by Tiam1 were predominantly on the actin cytoskeleton interacting proteins, apoptotic initiators and tumorogenic potential targets. The silenced phenotype resulted in decreased growth and increased apoptosis with non-invasive characteristics. Transfection of full length and N-terminal truncated construct (C1199) clearly revealed membrane localization of Tiam1 and not in the case of C580 construct. F-actin staining showed the interaction of Tiam1 with actin in the membrane edges that leads to ruffling, and also imparts varying invasive potential to the cell. The results obtained from our study show for the first time that Tiam1 modulates the cell invasion, mediated by actin cytoskeleton remodeling in RB.
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Affiliation(s)
- Nithya Subramanian
- Larsen and Toubro Department of Ocular Pathology, Vision Research Foundation, Sankara Nethralaya, Chennai, India
- Nanomedicine Laboratory of Immunology and Molecular Biomedical Research (N-LIMBR), School of Medicine (SoM), Molecular and Medical Research (MMR) Strategic Research Centre, Faculty of Health, Deakin University, Geelong Technology Precinct (GTP), Geelong, Victoria, Australia
| | - Saranya Navaneethakrishnan
- Larsen and Toubro Department of Ocular Pathology, Vision Research Foundation, Sankara Nethralaya, Chennai, India
| | - Jyotirmay Biswas
- Larsen and Toubro Department of Ocular Pathology, Vision Research Foundation, Sankara Nethralaya, Chennai, India
| | - Rupinder K. Kanwar
- Nanomedicine Laboratory of Immunology and Molecular Biomedical Research (N-LIMBR), School of Medicine (SoM), Molecular and Medical Research (MMR) Strategic Research Centre, Faculty of Health, Deakin University, Geelong Technology Precinct (GTP), Geelong, Victoria, Australia
| | - Jagat R. Kanwar
- Nanomedicine Laboratory of Immunology and Molecular Biomedical Research (N-LIMBR), School of Medicine (SoM), Molecular and Medical Research (MMR) Strategic Research Centre, Faculty of Health, Deakin University, Geelong Technology Precinct (GTP), Geelong, Victoria, Australia
- * E-mail: (SK); (JRK)
| | - Subramanian Krishnakumar
- Larsen and Toubro Department of Ocular Pathology, Vision Research Foundation, Sankara Nethralaya, Chennai, India
- * E-mail: (SK); (JRK)
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MAP1B-dependent Rac activation is required for AMPA receptor endocytosis during long-term depression. EMBO J 2013; 32:2287-99. [PMID: 23881099 DOI: 10.1038/emboj.2013.166] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Accepted: 07/02/2013] [Indexed: 02/07/2023] Open
Abstract
The microtubule-associated protein 1B (MAP1B) plays critical roles in neurite growth and synapse maturation during brain development. This protein is well expressed in the adult brain. However, its function in mature neurons remains unknown. We have used a genetically modified mouse model and shRNA techniques to assess the role of MAP1B at established synapses, bypassing MAP1B functions during neuronal development. Under these conditions, we found that MAP1B deficiency alters synaptic plasticity by specifically impairing long-term depression (LTD) expression. Interestingly, this is due to a failure to trigger AMPA receptor endocytosis and spine shrinkage during LTD. These defects are accompanied by an impaired targeting of the Rac1 activator Tiam1 at synaptic compartments. Accordingly, LTD and AMPA receptor endocytosis are restored in MAP1B-deficient neurons by providing additional Rac1. Therefore, these results indicate that the MAP1B-Tiam1-Rac1 relay is essential for spine structural plasticity and removal of AMPA receptors from synapses during LTD. This work highlights the importance of MAPs as signalling hubs controlling the actin cytoskeleton and receptor trafficking during plasticity in mature neurons.
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