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Ka M, Smith AL, Kim WY. MTOR controls genesis and autophagy of GABAergic interneurons during brain development. Autophagy 2017; 13:1348-1363. [PMID: 28598226 DOI: 10.1080/15548627.2017.1327927] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Interneuron progenitors in the ganglionic eminence of the ventral telencephalon generate most cortical interneurons during brain development. However, the regulatory mechanism of interneuron progenitors remains poorly understood. Here, we show that MTOR (mechanistic target of rapamycin [serine/threonine kinase]) regulates proliferation and macroautophagy/autophagy of interneuron progenitors in the developing ventral telencephalon. To investigate the role of MTOR in interneuron progenitors, we conditionally deleted the Mtor gene in mouse interneuron progenitors and their progeny by using Tg(mI56i-cre,EGFP)1Kc/Dlx5/6-Cre-IRES-EGFP and Nkx2-1-Cre drivers. We found that Mtor deletion markedly reduced the number of interneurons in the cerebral cortex. However, relative positioning of cortical interneurons was normal, suggesting that disruption of progenitor self-renewal caused the decreased number of cortical interneurons in the Mtor-deleted brain. Indeed, Mtor-deleted interneuron progenitors showed abnormal proliferation and cell cycle progression. Additionally, we detected a significant activation of autophagy in Mtor-deleted brain. Our findings suggest that MTOR plays a critical role in the regulation of cortical interneuron number and autophagy in the developing brain.
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Affiliation(s)
- Minhan Ka
- a Department of Developmental Neuroscience , Munroe-Meyer Institute, University of Nebraska Medical Center , Omaha , NE , USA
| | - Amanda L Smith
- a Department of Developmental Neuroscience , Munroe-Meyer Institute, University of Nebraska Medical Center , Omaha , NE , USA
| | - Woo-Yang Kim
- a Department of Developmental Neuroscience , Munroe-Meyer Institute, University of Nebraska Medical Center , Omaha , NE , USA
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52
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Wang T, Zhao M, Liang D, Bose U, Kaur S, McManus DP, Cummins SF. Changes in the neuropeptide content of Biomphalaria ganglia nervous system following Schistosoma infection. Parasit Vectors 2017; 10:275. [PMID: 28578678 PMCID: PMC5455113 DOI: 10.1186/s13071-017-2218-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 05/24/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Molluscs, including snails, are prone to parasite infection, which can lead to massive physiological and behavioural changes, yet many of the molecular components involved remain unresolved. Central to this point is the neural system that in snails consists of several ganglia that regulate the animals' physiology and behaviour patterns. The availability of a genomic resource for the freshwater snail Biomphalaria glabrata provides a mean towards the high throughput analysis of changes in the central nervous system (CNS) following infection with Schistosoma miracidia. RESULTS In this study, we performed a proteomic analysis of the B. glabrata CNS at pre-patent infection, providing a list of proteins that were further used within a protein-protein interaction (PPI) framework against S. mansoni proteins. A hub with most connections for both non-infected and infected Biomphalaria includes leucine aminopeptidase 2 (LAP2), which interacts with numerous miracidia proteins that together belong to the immunoglobulin family of cell adhesion related molecules. We additionally reveal the presence of at least 165 neuropeptides derived from the precursors of buccalin, enterin, FMRF, FVRI, pedal peptide 1, 2, 3 and 4, RYamide, RFamide, pleurin and others. Many of these were present at significantly reduced levels in the snail's CNS post-infection, such as the egg laying hormone, a neuropeptide required to initiate egg laying in gastropod molluscs. CONCLUSIONS Our analysis demonstrates that LAP2 may be a key component that regulates parasite infection physiology, as well as establishing that parasite-induced reproductive castration may be facilitated by significant reductions in reproduction-associated neuropeptides. This work helps in our understanding of molluscan neuropeptides and further stimulates advances in parasite-host interactions.
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Affiliation(s)
- Tianfang Wang
- Genecology Research Centre, Faculty of Science, Health and Education, University of the Sunshine Coast, Maroochydore DC, Queensland 4558 Australia
| | - Min Zhao
- Genecology Research Centre, Faculty of Science, Health and Education, University of the Sunshine Coast, Maroochydore DC, Queensland 4558 Australia
| | - Di Liang
- Genecology Research Centre, Faculty of Science, Health and Education, University of the Sunshine Coast, Maroochydore DC, Queensland 4558 Australia
| | - Utpal Bose
- Genecology Research Centre, Faculty of Science, Health and Education, University of the Sunshine Coast, Maroochydore DC, Queensland 4558 Australia
| | - Satwant Kaur
- Institute of Environment, Health and Societies, Brunel University London, Kingston Lane, London, UB8 3PH UK
| | - Donald P. McManus
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Queensland 4006 Australia
| | - Scott F. Cummins
- Genecology Research Centre, Faculty of Science, Health and Education, University of the Sunshine Coast, Maroochydore DC, Queensland 4558 Australia
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53
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Moffat JJ, Ka M, Jung EM, Smith AL, Kim WY. The role of MACF1 in nervous system development and maintenance. Semin Cell Dev Biol 2017; 69:9-17. [PMID: 28579452 DOI: 10.1016/j.semcdb.2017.05.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 05/12/2017] [Accepted: 05/29/2017] [Indexed: 12/14/2022]
Abstract
Microtubule-actin crosslinking factor 1 (MACF1), also known as actin crosslinking factor 7 (ACF7), is essential for proper modulation of actin and microtubule cytoskeletal networks. Most MACF1 isoforms are expressed broadly in the body, but some are exclusively found in the nervous system. Consequentially, MACF1 is integrally involved in multiple neural processes during development and in adulthood, including neurite outgrowth and neuronal migration. Furthermore, MACF1 participates in several signaling pathways, including the Wnt/β-catenin and GSK-3 signaling pathways, which regulate key cellular processes, such as proliferation and cell migration. Genetic mutation or dysregulation of the MACF1 gene has been associated with neurodevelopmental and neurodegenerative diseases, specifically schizophrenia and Parkinson's disease. MACF1 may also play a part in neuromuscular disorders and have a neuroprotective role in the optic nerve. In this review, the authors seek to synthesize recent findings relating to the roles of MACF1 within the nervous system and explore potential novel functions of MACF1 not yet examined.
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Affiliation(s)
- Jeffrey J Moffat
- Department of Developmental Neuroscience, Munroe-Meyer Institute, University of Nebraska Medical Center, Omaha, NE, USA.
| | - Minhan Ka
- Department of Developmental Neuroscience, Munroe-Meyer Institute, University of Nebraska Medical Center, Omaha, NE, USA.
| | - Eui-Man Jung
- Department of Developmental Neuroscience, Munroe-Meyer Institute, University of Nebraska Medical Center, Omaha, NE, USA.
| | - Amanda L Smith
- Department of Developmental Neuroscience, Munroe-Meyer Institute, University of Nebraska Medical Center, Omaha, NE, USA.
| | - Woo-Yang Kim
- Department of Developmental Neuroscience, Munroe-Meyer Institute, University of Nebraska Medical Center, Omaha, NE, USA.
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54
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Hu L, Xiao Y, Xiong Z, Zhao F, Yin C, Zhang Y, Su P, Li D, Chen Z, Ma X, Zhang G, Qian A. MACF1, versatility in tissue-specific function and in human disease. Semin Cell Dev Biol 2017; 69:3-8. [PMID: 28577926 DOI: 10.1016/j.semcdb.2017.05.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 05/18/2017] [Accepted: 05/26/2017] [Indexed: 01/24/2023]
Abstract
Spectraplakins are a family of evolutionarily conserved gigantic proteins and play critical roles in many cytoskeleton-related processes. Microtubule actin crosslinking factor 1 (MACF1) is one of the most versatile spectraplakin with multiple isoforms. As a broadly expressed mammalian spectraplakin, MACF1 is important in maintaining normal functions of many tissues. The loss-of-function studies using knockout mouse models reveal the pivotal roles of MACF1 in embryo development, skin integrity maintenance, neural development, bone formation, and colonic paracellular permeability. Mutation in the human MACF1 gene causes a novel myopathy genetic disease. In addition, abnormal expression of MACF1 is associated with schizophrenia, Parkinson's disease, cancer and osteoporosis. This demonstrates the crucial roles of MACF1 in physiology and pathology. Here, we review the research advances of MACF1's roles in specific tissue and in human diseases, providing the perspectives of MACF1 for future studies.
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Affiliation(s)
- Lifang Hu
- Laboratory for Bone Metabolism, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China; Shenzhen Research Institute of Northwestern Polytechnical University, Shenzhen, 518057, China; NPU-HKBU Joint Research Centre for Translational Medicine on Musculoskeletal Health in Space, Northwestern Polytechnical University, Xi'an 710072, China
| | - Yunyun Xiao
- Laboratory for Bone Metabolism, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China; Shenzhen Research Institute of Northwestern Polytechnical University, Shenzhen, 518057, China; NPU-HKBU Joint Research Centre for Translational Medicine on Musculoskeletal Health in Space, Northwestern Polytechnical University, Xi'an 710072, China
| | - Zhipeng Xiong
- Laboratory for Bone Metabolism, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China; Shenzhen Research Institute of Northwestern Polytechnical University, Shenzhen, 518057, China; NPU-HKBU Joint Research Centre for Translational Medicine on Musculoskeletal Health in Space, Northwestern Polytechnical University, Xi'an 710072, China
| | - Fan Zhao
- Laboratory for Bone Metabolism, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China; Shenzhen Research Institute of Northwestern Polytechnical University, Shenzhen, 518057, China; NPU-HKBU Joint Research Centre for Translational Medicine on Musculoskeletal Health in Space, Northwestern Polytechnical University, Xi'an 710072, China
| | - Chong Yin
- Laboratory for Bone Metabolism, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China; Shenzhen Research Institute of Northwestern Polytechnical University, Shenzhen, 518057, China; NPU-HKBU Joint Research Centre for Translational Medicine on Musculoskeletal Health in Space, Northwestern Polytechnical University, Xi'an 710072, China
| | - Yan Zhang
- Laboratory for Bone Metabolism, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China; Shenzhen Research Institute of Northwestern Polytechnical University, Shenzhen, 518057, China; NPU-HKBU Joint Research Centre for Translational Medicine on Musculoskeletal Health in Space, Northwestern Polytechnical University, Xi'an 710072, China
| | - Peihong Su
- Laboratory for Bone Metabolism, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China; Shenzhen Research Institute of Northwestern Polytechnical University, Shenzhen, 518057, China; NPU-HKBU Joint Research Centre for Translational Medicine on Musculoskeletal Health in Space, Northwestern Polytechnical University, Xi'an 710072, China
| | - Dijie Li
- Laboratory for Bone Metabolism, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China; Shenzhen Research Institute of Northwestern Polytechnical University, Shenzhen, 518057, China; NPU-HKBU Joint Research Centre for Translational Medicine on Musculoskeletal Health in Space, Northwestern Polytechnical University, Xi'an 710072, China
| | - Zhihao Chen
- Laboratory for Bone Metabolism, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China; Shenzhen Research Institute of Northwestern Polytechnical University, Shenzhen, 518057, China; NPU-HKBU Joint Research Centre for Translational Medicine on Musculoskeletal Health in Space, Northwestern Polytechnical University, Xi'an 710072, China
| | - Xiaoli Ma
- Laboratory for Bone Metabolism, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China; Shenzhen Research Institute of Northwestern Polytechnical University, Shenzhen, 518057, China; NPU-HKBU Joint Research Centre for Translational Medicine on Musculoskeletal Health in Space, Northwestern Polytechnical University, Xi'an 710072, China
| | - Ge Zhang
- NPU-HKBU Joint Research Centre for Translational Medicine on Musculoskeletal Health in Space, Northwestern Polytechnical University, Xi'an 710072, China; Institute for Advancing Translational Medicine in Bone and Joint Diseases, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China
| | - Airong Qian
- Laboratory for Bone Metabolism, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China; Shenzhen Research Institute of Northwestern Polytechnical University, Shenzhen, 518057, China; NPU-HKBU Joint Research Centre for Translational Medicine on Musculoskeletal Health in Space, Northwestern Polytechnical University, Xi'an 710072, China.
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Ma Y, Yue J, Zhang Y, Shi C, Odenwald M, Liang WG, Wei Q, Goel A, Gou X, Zhang J, Chen SY, Tang WJ, Turner JR, Yang F, Liang H, Qin H, Wu X. ACF7 regulates inflammatory colitis and intestinal wound response by orchestrating tight junction dynamics. Nat Commun 2017; 8:15375. [PMID: 28541346 PMCID: PMC5458510 DOI: 10.1038/ncomms15375] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 03/16/2017] [Indexed: 12/12/2022] Open
Abstract
In the intestinal epithelium, the aberrant regulation of cell/cell junctions leads to intestinal barrier defects, which may promote the onset and enhance the severity of inflammatory bowel disease (IBD). However, it remains unclear how the coordinated behaviour of cytoskeletal network may contribute to cell junctional dynamics. In this report, we identified ACF7, a crosslinker of microtubules and F-actin, as an essential player in this process. Loss of ACF7 leads to aberrant microtubule organization, tight junction stabilization and impaired wound closure in vitro. With the mouse genetics approach, we show that ablation of ACF7 inhibits intestinal wound healing and greatly increases susceptibility to experimental colitis in mice. ACF7 level is also correlated with development and progression of ulcerative colitis (UC) in human patients. Together, our results reveal an important molecular mechanism whereby coordinated cytoskeletal dynamics contributes to cell adhesion regulation during intestinal wound repair and the development of IBD. The cytoskeleton plays a key role in cell/cell junction formation, but how the coordinated behaviour of the cytoskeleton contributes is not known. Here the authors show that actin-microtubule crosslinker ACF7 plays a key role in tight junction stabilization and wound healing in intestinal epithelium.
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Affiliation(s)
- Yanlei Ma
- Department of GI surgery, Shanghai Tenth People's Hospital Affiliated with Tongji University, 301 Yanchang Road, Shanghai 200072, China.,The University of Chicago, Ben May Department for Cancer Research, Chicago, Illinois 60637, USA.,State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, Ministry of Science and Technology of China, Guanxi Normal University, Guilin 541004, China
| | - Jiping Yue
- The University of Chicago, Ben May Department for Cancer Research, Chicago, Illinois 60637, USA
| | - Yao Zhang
- Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Chenzhang Shi
- Department of GI surgery, Shanghai Tenth People's Hospital Affiliated with Tongji University, 301 Yanchang Road, Shanghai 200072, China
| | - Matt Odenwald
- Pritzker School of Medicine, University of Chicago, Chicago, Illinois 60637, USA
| | - Wenguang G Liang
- The University of Chicago, Ben May Department for Cancer Research, Chicago, Illinois 60637, USA
| | - Qing Wei
- Department of Pathology, Shanghai Tenth People's Hospital Affiliated with Tongji University, 301 Yanchang Road, Shanghai 200072, China
| | - Ajay Goel
- Center for Gastrointestinal Research, Center for Epigenetics, Cancer Prevention and Cancer Genomics, Baylor Scott &White Research Institute and Charles A. Sammons Cancer Center, Texas, USA
| | - Xuewen Gou
- The University of Chicago, Ben May Department for Cancer Research, Chicago, Illinois 60637, USA
| | - Jamie Zhang
- The University of Chicago, Ben May Department for Cancer Research, Chicago, Illinois 60637, USA
| | - Shao-Yu Chen
- Department of Pharmacology and Toxicology, University of Louisville Health Science Center, Louisville, Kentucky 40292, USA
| | - Wei-Jen Tang
- The University of Chicago, Ben May Department for Cancer Research, Chicago, Illinois 60637, USA
| | - Jerrold R Turner
- Departments of Pathology and Medicine (GI), Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Feng Yang
- State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, Ministry of Science and Technology of China, Guanxi Normal University, Guilin 541004, China
| | - Hong Liang
- State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, Ministry of Science and Technology of China, Guanxi Normal University, Guilin 541004, China
| | - Huanlong Qin
- Department of GI surgery, Shanghai Tenth People's Hospital Affiliated with Tongji University, 301 Yanchang Road, Shanghai 200072, China
| | - Xiaoyang Wu
- The University of Chicago, Ben May Department for Cancer Research, Chicago, Illinois 60637, USA
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56
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Balachandran A, Wong R, Stoilov P, Pan S, Blencowe B, Cheung P, Harrigan PR, Cochrane A. Identification of small molecule modulators of HIV-1 Tat and Rev protein accumulation. Retrovirology 2017; 14:7. [PMID: 28122580 PMCID: PMC5267425 DOI: 10.1186/s12977-017-0330-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 01/04/2017] [Indexed: 11/10/2022] Open
Abstract
Background HIV-1 replication is critically dependent upon controlled processing of its RNA and the activities provided by its encoded regulatory factors Tat and Rev. A screen of small molecule modulators of RNA processing identified several which inhibited virus gene expression, affecting both relative abundance of specific HIV-1 RNAs and the levels of Tat and Rev proteins. Results The screen for small molecules modulators of HIV-1 gene expression at the post-transcriptional level identified three (a pyrimidin-7-amine, biphenylcarboxamide, and benzohydrazide, designated 791, 833, and 892, respectively) that not only reduce expression of HIV-1 Gag and Env and alter the accumulation of viral RNAs, but also dramatically decrease Tat and Rev levels. Analyses of viral RNA levels by qRTPCR and RTPCR indicated that the loss of either protein could not be attributed to changes in abundance of the mRNAs encoding these factors. However, addition of the proteasome inhibitor MG132 did result in significant restoration of Tat expression, indicating that the compounds are affecting Tat synthesis and/or degradation. Tests in the context of replicating HIV-1 in PBMCs confirmed that 791 significantly reduced virus replication. Parallel analyses of the effect of the compounds on host gene expression revealed only minor changes in either mRNA abundance or alternative splicing. Subsequent tests suggest that 791 may function by reducing levels of the Tat/Rev chaperone Nap1. Conclusions The three compounds examined (791, 833, 892), despite their lack of structural similarity, all suppressed HIV-1 gene expression by preventing accumulation of two key HIV-1 regulatory factors, Tat and Rev. These findings demonstrate that selective disruption of HIV-1 gene expression can be achieved. Electronic supplementary material The online version of this article (doi:10.1186/s12977-017-0330-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ahalya Balachandran
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON, M5S1A8, Canada
| | - Raymond Wong
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Peter Stoilov
- Department of Biochemistry, University of West Virginia, Morgantown, WV, USA
| | - Sandy Pan
- Donnelly Centre, University of Toronto, Toronto, ON, Canada
| | - Benjamin Blencowe
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON, M5S1A8, Canada.,Donnelly Centre, University of Toronto, Toronto, ON, Canada
| | - Peter Cheung
- British Columbia Centre for Excellence in HIV/AIDS, 608-1081 Burrard St., Vancouver, BC, Canada
| | - P Richard Harrigan
- British Columbia Centre for Excellence in HIV/AIDS, 608-1081 Burrard St., Vancouver, BC, Canada.,Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Alan Cochrane
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, ON, M5S1A8, Canada.
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57
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Qu Y, Hahn I, Webb SED, Pearce SP, Prokop A. Periodic actin structures in neuronal axons are required to maintain microtubules. Mol Biol Cell 2016; 28:296-308. [PMID: 27881663 PMCID: PMC5231898 DOI: 10.1091/mbc.e16-10-0727] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 11/09/2016] [Accepted: 11/15/2016] [Indexed: 12/31/2022] Open
Abstract
Drosophila genetics is combined with high-resolution microscopy and a number of functional readouts to demonstrate key factors required for the presence of regularly spaced rings of cortical actin in axons. The data suggest important roles for the actin rings in microtubule regulation, most likely by sustaining their polymerization. Axons are cable-like neuronal processes wiring the nervous system. They contain parallel bundles of microtubules as structural backbones, surrounded by regularly spaced actin rings termed the periodic membrane skeleton (PMS). Despite being an evolutionarily conserved, ubiquitous, highly ordered feature of axons, the function of PMS is unknown. Here we studied PMS abundance, organization, and function, combining versatile Drosophila genetics with superresolution microscopy and various functional readouts. Analyses with 11 actin regulators and three actin-targeting drugs suggest that PMS contains short actin filaments that are depolymerization resistant and sensitive to spectrin, adducin, and nucleator deficiency, consistent with microscopy-derived models proposing PMS as specialized cortical actin. Upon actin removal, we observed gaps in microtubule bundles, reduced microtubule polymerization, and reduced axon numbers, suggesting a role of PMS in microtubule organization. These effects become strongly enhanced when carried out in neurons lacking the microtubule-stabilizing protein Short stop (Shot). Combining the aforementioned actin manipulations with Shot deficiency revealed a close correlation between PMS abundance and microtubule regulation, consistent with a model in which PMS-dependent microtubule polymerization contributes to their maintenance in axons. We discuss potential implications of this novel PMS function along axon shafts for axon maintenance and regeneration.
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Affiliation(s)
- Yue Qu
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, United Kingdom
| | - Ines Hahn
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, United Kingdom
| | - Stephen E D Webb
- Rutherford Appleton Laboratory, Science and Technology Facilities Council, Didcot OX11 0QX, United Kingdom
| | - Simon P Pearce
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, United Kingdom.,School of Mathematics, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Andreas Prokop
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, United Kingdom
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58
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Hu L, Su P, Li R, Yin C, Zhang Y, Shang P, Yang T, Qian A. Isoforms, structures, and functions of versatile spectraplakin MACF1. BMB Rep 2016; 49:37-44. [PMID: 26521939 PMCID: PMC4914211 DOI: 10.5483/bmbrep.2016.49.1.185] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Indexed: 11/20/2022] Open
Abstract
Spectraplakins are crucially important communicators, linking cytoskeletal components to each other and cellular junctions. Microtubule actin crosslinking factor 1 (MACF1), also known as actin crosslinking family 7 (ACF7), is a member of the spectraplakin family. It is expressed in numerous tissues and cells as one extensively studied spectraplakin. MACF1 has several isoforms with unique structures and well-known function to be able to crosslink F-actin and microtubules. MACF1 is one versatile spectraplakin with various functions in cell processes, embryo development, tissue-specific functions, and human diseases. The importance of MACF1 has become more apparent in recent years. Here, we summarize the current knowledge on the presence and function of MACF1 and provide perspectives on future research of MACF1 based on our studies and others. [BMB Reports 2016; 49(1): 37-44]
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Affiliation(s)
- Lifang Hu
- Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China
| | - Peihong Su
- Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China
| | - Runzhi Li
- Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China
| | - Chong Yin
- Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China
| | - Yan Zhang
- Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China
| | - Peng Shang
- Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China
| | - Tuanmin Yang
- Honghui Hospital, Xi'an Jiaotong University College of Medicine, Xi'an, Shaanxi 710054, P. R. China
| | - Airong Qian
- Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China
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59
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Ka M, Kook YH, Liao K, Buch S, Kim WY. Transactivation of TrkB by Sigma-1 receptor mediates cocaine-induced changes in dendritic spine density and morphology in hippocampal and cortical neurons. Cell Death Dis 2016; 7:e2414. [PMID: 27735948 PMCID: PMC5133986 DOI: 10.1038/cddis.2016.319] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 08/31/2016] [Accepted: 09/09/2016] [Indexed: 01/02/2023]
Abstract
Cocaine is a highly addictive narcotic associated with dendritic spine plasticity in the striatum. However, it remains elusive whether cocaine modifies spines in a cell type-specific or region-specific manner or whether it alters different types of synapses in the brain. In addition, there is a paucity of data on the regulatory mechanism(s) involved in cocaine-induced modification of spine density. In the current study, we report that cocaine exposure differentially alters spine density, spine morphology, and the types of synapses in hippocampal and cortical neurons. Cocaine exposure in the hippocampus resulted in increased spine density, but had no significant effect on cortical neurons. Although cocaine exposure altered spine morphology in both cell types, the patterns of spine morphology were distinct for each cell type. Furthermore, we observed that cocaine selectively affects the density of excitatory synapses. Intriguingly, in hippocampal neurons cocaine-mediated effects on spine density and morphology involved sigma-1 receptor (Sig-1 R) and its downstream TrkB signaling, which were not the case in cortical neurons. Furthermore, pharmacological inhibition of Sig-1 R prevented cocaine-induced TrkB activation in hippocampal neurons. Our findings reveal a novel mechanism by which cocaine induces selective changes in spine morphology, spine density, and synapse formation, and could provide insights into the cellular basis for the cognitive impairment observed in cocaine addicts.
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Affiliation(s)
- Minhan Ka
- Department of Developmental Neuroscience, Munroe-Meyer Institute, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Yeon-Hee Kook
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Ke Liao
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Shilpa Buch
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Woo-Yang Kim
- Department of Developmental Neuroscience, Munroe-Meyer Institute, University of Nebraska Medical Center, Omaha, NE 68198, USA
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Abstract
This review discusses the spectrin superfamily of proteins that function to connect cytoskeletal elements to each other, the cell membrane, and the nucleus. The signature domain is the spectrin repeat, a 106-122-amino-acid segment comprising three α-helices. α-actinin is considered to be the ancestral protein and functions to cross-link actin filaments. It then evolved to generate spectrin and dystrophin that function to link the actin cytoskeleton to the cell membrane, as well as the spectraplakins and plakins that link cytoskeletal elements to each other and to junctional complexes. A final class comprises the nesprins, which are able to bind to the nuclear membrane. This review discusses the domain organization of the various spectrin family members, their roles in protein-protein interactions, and their roles in disease, as determined from mutations, and it also describes the functional roles of the family members as determined from null phenotypes.
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Affiliation(s)
- Ronald K H Liem
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York 10032
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Zhang YW, Yan L, Huang L, Huang HQ. Cerebral ganglion ultrastructure and differential proteins revealed using proteomics in the aplysiid (Notarcus leachii cirrosus Stimpson) under cadmium and lead stress. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2016; 46:17-26. [PMID: 27414742 DOI: 10.1016/j.etap.2016.06.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 05/30/2016] [Accepted: 06/18/2016] [Indexed: 06/06/2023]
Abstract
Cadmium (Cd) and lead (Pb) are both highly toxic metals in environments. However the toxicological mechanism is not clear. In this study, the aplysiid, Notarcus leachii cirrosus Stimpson (NLCS) was subjected to Cd (NLCS-Cd) or Pb (NLCS-Pb). The cerebral ganglion of NLCS was investigated with a transmission electron microscope. Next the differential proteins were separated and identified using proteomic approaches. Eighteen protein spots in NLCS-Cd and seventeen protein spots in NLCS-Pb were observed to be significantly changed. These protein spots were further excised in gels and identified. A hypothetical pathway was drawn to show the correlation between the partially identified proteins. The results indicated that damage to the cerebral ganglion was follows: cell apoptosis, lysosomes proliferation, cytoskeleton disruption, and oxidative stress. These phenomena and data indicated potential biomarkers for evaluating the contamination levels of Cd and Pb. This study provided positive insights into the mechanisms of Cd and Pb toxicity.
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MESH Headings
- Animals
- Aplysia/drug effects
- Aplysia/metabolism
- Biomarkers/analysis
- Biomarkers/metabolism
- Cadmium/pharmacokinetics
- Cadmium/toxicity
- Ecotoxicology/methods
- Electrophoresis, Gel, Two-Dimensional
- Ganglia, Invertebrate/drug effects
- Ganglia, Invertebrate/metabolism
- Ganglia, Invertebrate/ultrastructure
- Lead/pharmacokinetics
- Lead/toxicity
- Microscopy, Electron, Transmission
- Proteins/analysis
- Proteins/metabolism
- Proteomics/methods
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
- Water Pollutants, Chemical/pharmacokinetics
- Water Pollutants, Chemical/toxicity
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Affiliation(s)
- Yi-Wei Zhang
- State Key Laboratory of Stress Cell Biology, School of Life Science, Xiamen University, Xiamen 361102, China
| | - Li Yan
- State Key Laboratory of Stress Cell Biology, School of Life Science, Xiamen University, Xiamen 361102, China
| | - Lin Huang
- State Key Laboratory of Stress Cell Biology, School of Life Science, Xiamen University, Xiamen 361102, China; Department of Chemistry, Oregon State University, Corvallis, OR 97331, USA
| | - He-Qing Huang
- State Key Laboratory of Stress Cell Biology, School of Life Science, Xiamen University, Xiamen 361102, China; State Key Laboratory of Marine Environmental Science, School of Ocean and Earth Science, Xiamen University, Xiamen 361102, China; Department of Chemistry, College of Chemistry & Chemical Engineering, and the Key Laboratory of Chemical Biology of Fujian Province, Xiamen University, Xiamen 361102, China.
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62
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Hu L, Su P, Li R, Yan K, Chen Z, Shang P, Qian A. Knockdown of microtubule actin crosslinking factor 1 inhibits cell proliferation in MC3T3-E1 osteoblastic cells. BMB Rep 2016; 48:583-8. [PMID: 26277981 PMCID: PMC4911186 DOI: 10.5483/bmbrep.2015.48.10.098] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Indexed: 01/12/2023] Open
Abstract
Microtubule actin crosslinking factor 1 (MACF1), a widely expressed cytoskeletal linker, plays important roles in various cells by regulating cytoskeleton dynamics. However, its role in osteoblastic cells is not well understood. Based on our previous findings that the association of MACF1 with F-actin and microtubules in osteoblast-like cells was altered under magnetic force conditions, here, by adopting a stable MACF1-knockdown MC3T3-E1 osteoblastic cell line, we found that MACF1 knockdown induced large cells with a binuclear/multinuclear structure. Further, immunofluorescence staining showed disorganization of F-actin and microtubules in MACF1-knockdown cells. Cell counting revealed significant decrease of cell proliferation and cell cycle analysis showed an S phase cell cycle arrest in MACF1-knockdown cells. Moreover and interestingly, MACF1 knockdown showed a potential effect on cellular MTT reduction activity and mitochondrial content, suggesting an impact on cellular metabolic activity. These results together indicate an important role of MACF1 in regulating osteoblastic cell morphology and function. [BMB Reports 2015; 48(10): 583-588]
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Affiliation(s)
- Lifang Hu
- Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, P. R. China
| | - Peihong Su
- Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, P. R. China
| | - Runzhi Li
- Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, P. R. China
| | - Kun Yan
- Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, P. R. China
| | - Zhihao Chen
- Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, P. R. China
| | - Peng Shang
- Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, P. R. China
| | - Airong Qian
- Key Laboratory for Space Bioscience and Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, P. R. China
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63
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Essential Roles for ARID1B in Dendritic Arborization and Spine Morphology of Developing Pyramidal Neurons. J Neurosci 2016; 36:2723-42. [PMID: 26937011 DOI: 10.1523/jneurosci.2321-15.2016] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
UNLABELLED De novo truncating mutations in ARID1B, a chromatin-remodeling gene, cause Coffin-Siris syndrome, a developmental disorder characterized by intellectual disability and speech impairment; however, how the genetic elimination leads to cognitive dysfunction remains unknown. Thus, we investigated the neural functions of ARID1B during brain development. Here, we show that ARID1B regulates dendritic differentiation in the developing mouse brain. We knocked down ARID1B expression in mouse pyramidal neurons using in utero gene delivery methodologies. ARID1B knockdown suppressed dendritic arborization of cortical and hippocampal pyramidal neurons in mice. The abnormal development of dendrites accompanied a decrease in dendritic outgrowth into layer I. Furthermore, knockdown of ARID1B resulted in aberrant dendritic spines and synaptic transmission. Finally, ARID1B deficiency led to altered expression of c-Fos and Arc, and overexpression of these factors rescued abnormal differentiation induced by ARID1B knockdown. Our results demonstrate a novel role for ARID1B in neuronal differentiation and provide new insights into the origin of cognitive dysfunction associated with developmental intellectual disability. SIGNIFICANCE STATEMENT Haploinsufficiency of ARID1B, a component of chromatin remodeling complex, causes intellectual disability. However, the role of ARID1B in brain development is unknown. Here, we demonstrate that ARID1B is required for neuronal differentiation in the developing brain, such as in dendritic arborization and synapse formation. Our findings suggest that ARID1B plays a critical role in the establishment of cognitive circuitry by regulating dendritic complexity. Thus, ARID1B deficiency may cause intellectual disability via abnormal brain wiring induced by the defective differentiation of cortical neurons.
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64
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Yue J, Zhang Y, Liang WG, Gou X, Lee P, Liu H, Lyu W, Tang WJ, Chen SY, Yang F, Liang H, Wu X. In vivo epidermal migration requires focal adhesion targeting of ACF7. Nat Commun 2016; 7:11692. [PMID: 27216888 PMCID: PMC5476826 DOI: 10.1038/ncomms11692] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 04/19/2016] [Indexed: 11/09/2022] Open
Abstract
Turnover of focal adhesions allows cell retraction, which is essential for cell migration. The mammalian spectraplakin protein, ACF7 (Actin-Crosslinking Factor 7), promotes focal adhesion dynamics by targeting of microtubule plus ends towards focal adhesions. However, it remains unclear how the activity of ACF7 is regulated spatiotemporally to achieve focal adhesion-specific guidance of microtubule. To explore the potential mechanisms, we resolve the crystal structure of ACF7’s NT (amino-terminal) domain, which mediates F-actin interactions. Structural analysis leads to identification of a key tyrosine residue at the calponin homology (CH) domain of ACF7, whose phosphorylation by Src/FAK (focal adhesion kinase) complex is essential for F-actin binding of ACF7. Using skin epidermis as a model system, we further demonstrate that the phosphorylation of ACF7 plays an indispensable role in focal adhesion dynamics and epidermal migration in vitro and in vivo. Together, our findings provide critical insights into the molecular mechanisms underlying coordinated cytoskeletal dynamics during cell movement. The spectraplakin protein ACF7 binds to actin at focal adhesions and targets microtubule plus ends to focal adhesions, promoting their disassembly. Here the authors reveal that ACF7 is phosphorylated by Src/FAK, and this regulates actin binding and focal adhesion dynamics in vitro and in vivo.
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Affiliation(s)
- Jiping Yue
- Ben May Department for Cancer Research, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA
| | - Yao Zhang
- State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, Ministry of Science and Technology of China, Guanxi Normal University, Guilin 541004, China
| | - Wenguang G Liang
- Ben May Department for Cancer Research, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA
| | - Xuewen Gou
- Ben May Department for Cancer Research, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA
| | - Philbert Lee
- Ben May Department for Cancer Research, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA
| | - Han Liu
- Ben May Department for Cancer Research, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA
| | - Wanqing Lyu
- Ben May Department for Cancer Research, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA
| | - Wei-Jen Tang
- Ben May Department for Cancer Research, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA
| | - Shao-Yu Chen
- Department of Pharmacology and Toxicology, University of Louisville Health Science Center, Louisville, Kentucky 40292, USA
| | - Feng Yang
- State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, Ministry of Science and Technology of China, Guanxi Normal University, Guilin 541004, China
| | - Hong Liang
- State Key Laboratory Cultivation Base for the Chemistry and Molecular Engineering of Medicinal Resources, Ministry of Science and Technology of China, Guanxi Normal University, Guilin 541004, China
| | - Xiaoyang Wu
- Ben May Department for Cancer Research, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA
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65
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Abstract
The growth and migration of neurons require continuous remodelling of the neuronal cytoskeleton, providing a versatile cellular framework for force generation and guided movement, in addition to structural support. Actin filaments and microtubules are central to the dynamic action of the cytoskeleton and rapid advances in imaging technologies are enabling ever more detailed visualisation of the dynamic intracellular networks that they form. However, these filaments do not act individually and an expanding body of evidence emphasises the importance of actin-microtubule crosstalk in orchestrating cytoskeletal dynamics. Here, we summarise our current understanding of the structure and dynamics of actin and microtubules in isolation, before reviewing both the mechanisms and the molecular players involved in mediating actin-microtubule crosstalk in neurons.
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Affiliation(s)
- Charlotte H Coles
- Laboratory for Axon Growth and Regeneration, German Center for Neurodegenerative Diseases (DZNE), Ludwig-Erhard-Allee 2, 53175, Bonn, Germany.
| | - Frank Bradke
- Laboratory for Axon Growth and Regeneration, German Center for Neurodegenerative Diseases (DZNE), Ludwig-Erhard-Allee 2, 53175, Bonn, Germany.
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66
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van de Willige D, Hoogenraad CC, Akhmanova A. Microtubule plus-end tracking proteins in neuronal development. Cell Mol Life Sci 2016; 73:2053-77. [PMID: 26969328 PMCID: PMC4834103 DOI: 10.1007/s00018-016-2168-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Revised: 02/04/2016] [Accepted: 02/22/2016] [Indexed: 11/28/2022]
Abstract
Regulation of the microtubule cytoskeleton is of pivotal importance for neuronal development and function. One such regulatory mechanism centers on microtubule plus-end tracking proteins (+TIPs): structurally and functionally diverse regulatory factors, which can form complex macromolecular assemblies at the growing microtubule plus-ends. +TIPs modulate important properties of microtubules including their dynamics and their ability to control cell polarity, membrane transport and signaling. Several neurodevelopmental and neurodegenerative diseases are associated with mutations in +TIPs or with misregulation of these proteins. In this review, we focus on the role and regulation of +TIPs in neuronal development and associated disorders.
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Affiliation(s)
- Dieudonnée van de Willige
- Cell Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Casper C Hoogenraad
- Cell Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.
| | - Anna Akhmanova
- Cell Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.
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67
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Cammarata GM, Bearce EA, Lowery LA. Cytoskeletal social networking in the growth cone: How +TIPs mediate microtubule-actin cross-linking to drive axon outgrowth and guidance. Cytoskeleton (Hoboken) 2016; 73:461-76. [PMID: 26783725 DOI: 10.1002/cm.21272] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 01/08/2016] [Accepted: 01/08/2016] [Indexed: 11/08/2022]
Abstract
The growth cone is a unique structure capable of guiding axons to their proper destinations. Within the growth cone, extracellular guidance cues are interpreted and then transduced into physical changes in the actin filament (F-actin) and microtubule cytoskeletons, providing direction and movement. While both cytoskeletal networks individually possess important growth cone-specific functions, recent data over the past several years point towards a more cooperative role between the two systems. Facilitating this interaction between F-actin and microtubules, microtubule plus-end tracking proteins (+TIPs) have been shown to link the two cytoskeletons together. Evidence suggests that many +TIPs can couple microtubules to F-actin dynamics, supporting both microtubule advance and retraction in the growth cone periphery. In addition, growing in vitro and in vivo data support a secondary role for +TIPs in which they may participate as F-actin nucleators, thus directly influencing F-actin dynamics and organization. This review focuses on how +TIPs may link F-actin and microtubules together in the growth cone, and how these interactions may influence axon guidance. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
| | | | - Laura Anne Lowery
- Department of Biology, Boston College, Chestnut Hill, Massachusetts.
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68
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Kroll JE, Kim J, Ohno-Machado L, de Souza SJ. Splicing Express: a software suite for alternative splicing analysis using next-generation sequencing data. PeerJ 2015; 3:e1419. [PMID: 26618088 PMCID: PMC4655094 DOI: 10.7717/peerj.1419] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 10/28/2015] [Indexed: 11/20/2022] Open
Abstract
Motivation. Alternative splicing events (ASEs) are prevalent in the transcriptome of eukaryotic species and are known to influence many biological phenomena. The identification and quantification of these events are crucial for a better understanding of biological processes. Next-generation DNA sequencing technologies have allowed deep characterization of transcriptomes and made it possible to address these issues. ASEs analysis, however, represents a challenging task especially when many different samples need to be compared. Some popular tools for the analysis of ASEs are known to report thousands of events without annotations and/or graphical representations. A new tool for the identification and visualization of ASEs is here described, which can be used by biologists without a solid bioinformatics background. Results. A software suite named Splicing Express was created to perform ASEs analysis from transcriptome sequencing data derived from next-generation DNA sequencing platforms. Its major goal is to serve the needs of biomedical researchers who do not have bioinformatics skills. Splicing Express performs automatic annotation of transcriptome data (GTF files) using gene coordinates available from the UCSC genome browser and allows the analysis of data from all available species. The identification of ASEs is done by a known algorithm previously implemented in another tool named Splooce. As a final result, Splicing Express creates a set of HTML files composed of graphics and tables designed to describe the expression profile of ASEs among all analyzed samples. By using RNA-Seq data from the Illumina Human Body Map and the Rat Body Map, we show that Splicing Express is able to perform all tasks in a straightforward way, identifying well-known specific events. Availability and Implementation.Splicing Express is written in Perl and is suitable to run only in UNIX-like systems. More details can be found at: http://www.bioinformatics-brazil.org/splicingexpress.
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Affiliation(s)
- Jose E Kroll
- Institute of Bioinformatics and Biotechnology , Natal, Rio Grande do Norte , Brazil ; Brain Institute, Universidade Federal do Rio Grande do Norte , Natal, Rio Grande do Norte , Brazil
| | - Jihoon Kim
- Department of Biomedical Informatics, University of California, San Diego , La Jolla, CA , United States
| | - Lucila Ohno-Machado
- Department of Biomedical Informatics, University of California, San Diego , La Jolla, CA , United States
| | - Sandro J de Souza
- Brain Institute, Universidade Federal do Rio Grande do Norte , Natal, Rio Grande do Norte , Brazil
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69
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Microtubule-Actin Crosslinking Factor 1 Is Required for Dendritic Arborization and Axon Outgrowth in the Developing Brain. Mol Neurobiol 2015; 53:6018-6032. [PMID: 26526844 DOI: 10.1007/s12035-015-9508-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 10/22/2015] [Indexed: 12/20/2022]
Abstract
Dendritic arborization and axon outgrowth are critical steps in the establishment of neural connectivity in the developing brain. Changes in the connectivity underlie cognitive dysfunction in neurodevelopmental disorders. However, molecules and associated mechanisms that play important roles in dendritic and axon outgrowth in the brain are only partially understood. Here, we show that microtubule-actin crosslinking factor 1 (MACF1) regulates dendritic arborization and axon outgrowth of developing pyramidal neurons by arranging cytoskeleton components and mediating GSK-3 signaling. MACF1 deletion using conditional mutant mice and in utero gene transfer in the developing brain markedly decreased dendritic branching of cortical and hippocampal pyramidal neurons. MACF1-deficient neurons showed reduced density and aberrant morphology of dendritic spines. Also, loss of MACF1 impaired the elongation of callosal axons in the brain. Actin and microtubule arrangement appeared abnormal in MACF1-deficient neurites. Finally, we found that GSK-3 is associated with MACF1-controlled dendritic differentiation. Our findings demonstrate a novel role for MACF1 in neurite differentiation that is critical to the creation of neuronal connectivity in the developing brain.
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70
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Jung EM, Ka M, Kim WY. Loss of GSK-3 Causes Abnormal Astrogenesis and Behavior in Mice. Mol Neurobiol 2015; 53:3954-3966. [PMID: 26179612 DOI: 10.1007/s12035-015-9326-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 06/25/2015] [Indexed: 12/20/2022]
Abstract
Altered activity of glycogen synthase kinase-3 (GSK-3) is associated with psychiatric diseases and neurodegenerative diseases. GSK-3 is a key regulator in multiple aspects of neuronal differentiation in the brain. However, little is known about the role of GSK-3 in astrocyte development. To examine the role of GSK-3 in astrocytes, we generated a conditional knockout mouse using a glial fibrillary acidic protein (GFAP)-cre driver, in which the GSK-3 alpha and beta genes are deleted in astrocytes. We found that GFAP-cre-mediated GSK-3 deletion led to a larger brain. The number and size of astrocytes were increased in GSK-3 mutant brains. The levels of GFAP and phospho-STAT3, indicators of astrogenesis, were elevated in GSK-3 mutants. Furthermore, we found upregulation of astrocyte regulatory molecules such as phospho-AKT, phospho-S6, and cyclin D in GSK-3 mutant brains. Finally, GSK-3 mutant mice exhibited aberrant anxiety and social behavior. Our results suggest that GSK-3 plays a significant role in astrocyte development and behavioral control in mice.
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Affiliation(s)
- Eui-Man Jung
- Department of Developmental Neuroscience, Munroe-Meyer Institute, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Minhan Ka
- Department of Developmental Neuroscience, Munroe-Meyer Institute, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Woo-Yang Kim
- Department of Developmental Neuroscience, Munroe-Meyer Institute, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
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