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Poole RJ, Flames N, Cochella L. Neurogenesis in Caenorhabditis elegans. Genetics 2024; 228:iyae116. [PMID: 39167071 PMCID: PMC11457946 DOI: 10.1093/genetics/iyae116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Accepted: 06/24/2024] [Indexed: 08/23/2024] Open
Abstract
Animals rely on their nervous systems to process sensory inputs, integrate these with internal signals, and produce behavioral outputs. This is enabled by the highly specialized morphologies and functions of neurons. Neuronal cells share multiple structural and physiological features, but they also come in a large diversity of types or classes that give the nervous system its broad range of functions and plasticity. This diversity, first recognized over a century ago, spurred classification efforts based on morphology, function, and molecular criteria. Caenorhabditis elegans, with its precisely mapped nervous system at the anatomical level, an extensive molecular description of most of its neurons, and its genetic amenability, has been a prime model for understanding how neurons develop and diversify at a mechanistic level. Here, we review the gene regulatory mechanisms driving neurogenesis and the diversification of neuron classes and subclasses in C. elegans. We discuss our current understanding of the specification of neuronal progenitors and their differentiation in terms of the transcription factors involved and ensuing changes in gene expression and chromatin landscape. The central theme that has emerged is that the identity of a neuron is defined by modules of gene batteries that are under control of parallel yet interconnected regulatory mechanisms. We focus on how, to achieve these terminal identities, cells integrate information along their developmental lineages. Moreover, we discuss how neurons are diversified postembryonically in a time-, genetic sex-, and activity-dependent manner. Finally, we discuss how the understanding of neuronal development can provide insights into the evolution of neuronal diversity.
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Affiliation(s)
- Richard J Poole
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
| | - Nuria Flames
- Developmental Neurobiology Unit, Instituto de Biomedicina de Valencia IBV-CSIC, Valencia 46012, Spain
| | - Luisa Cochella
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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2
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Lei J, Cao L, Li Y, Kan Q, Yang L, Dai W, Liu G, Fu J, Chen Y, Huang Q, Ho CT, Cao Y, Wen L. Physiological evaluation and transcriptomic and proteomic analyses to reveal the anti-aging and reproduction-promoting mechanisms of glycitein in Caenorhabditis elegans. Food Funct 2024; 15:9849-9862. [PMID: 39240213 DOI: 10.1039/d4fo02271h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/07/2024]
Abstract
Soy isoflavones from soy sauce residues have important biological activities. However, the anti-aging and reproduction-promoting effects of glycitein are still rarely reported. Here, we systematically evaluated and explored the anti-aging and reproduction-promoting effects of glycitein in Caenorhabditis elegans (C. elegans). Firstly, we analyzed the effects of glycitein on the lifespan under normal and heat stress, reproduction, locomotion, and reactive oxygen species (ROS) levels of C. elegans. The results showed that 100 μmol L-1 glycitein increased the anti-stress ability of nematodes and activated the antioxidant defense system. Secondly, transcriptomic and proteomic technologies were further used to explore in-depth the anti-aging and reproduction-promoting mechanisms of glycitein in C. elegans. The results showed that both differentially expressed proteins (DEPs) including PDE-2 and MSRA-1 and differentially expressed genes (DEGs) including skpo-2 and cytochrome P450 (cyp-35A3, cyp-35A5, cyp-35C1, cyp-35D1) were associated with the extension of the lifespan and the exertion of antioxidant capacity. VIT-1, plx-2, and Y73F8A.35 were related to promoting reproduction. ASP-1, DNJ-10, and abu-1 were related to the anti-stress ability of glycitein. Pathway analysis revealed that the longevity regulation pathway and FOXO signaling pathway were regulated by the changes in genes and proteins to improve the lifespan of the nematode. Moreover, hydrogenase regulation, longevity regulation, and lipid metabolism were regulated by the changes in genes and proteins to promote the reproduction of nematodes. This study not only demonstrates a viable strategy for utilizing soy sauce residues, but also provides a theoretical foundation and developmental insights for the future application of glycitein.
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Affiliation(s)
- Jianping Lei
- WENS Foodstuff Group Co., Ltd, Yunfu, 527400, China
| | - Longbifei Cao
- Department of Food Science, Rutgers University, New Brunswick, New Jersey 08901, USA
- Guangzhou Fenghuan Biotechnology Co., Ltd, Guangzhou, 510555, China
| | - Yifeng Li
- Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Guangzhou, 510642, China.
- Guangdong Huiertai Biotechnology Co., Ltd, Guangzhou, 510000, China
| | - Qixin Kan
- Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Guangzhou, 510642, China.
| | - Lixin Yang
- Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Guangzhou, 510642, China.
| | - Weijie Dai
- Guangdong Huiertai Biotechnology Co., Ltd, Guangzhou, 510000, China
| | - Guo Liu
- Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Guangzhou, 510642, China.
- College of Light Industry and Food, Zhongkai University of Agriculture and Engineering, Guangzhou, Guangdong, 510225, China
| | - Jiangyan Fu
- Guangdong Meiweixian Flavoring Foods Co., Ltd, Zhongshan, 528437, China
| | - Yunjiao Chen
- Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Guangzhou, 510642, China.
| | - Qingrong Huang
- Department of Food Science, Rutgers University, New Brunswick, New Jersey 08901, USA
| | - Chi-Tang Ho
- Department of Food Science, Rutgers University, New Brunswick, New Jersey 08901, USA
| | - Yong Cao
- Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Guangzhou, 510642, China.
| | - Linfeng Wen
- Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Guangzhou, 510642, China.
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Ow MC, Nishiguchi MA, Dar AR, Butcher RA, Hall SE. RNAi-dependent expression of sperm genes in ADL chemosensory neurons is required for olfactory responses in Caenorhabditis elegans. Front Mol Biosci 2024; 11:1396587. [PMID: 39055986 PMCID: PMC11269235 DOI: 10.3389/fmolb.2024.1396587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Accepted: 06/11/2024] [Indexed: 07/28/2024] Open
Abstract
Environmental conditions experienced early in the life of an animal can result in gene expression changes later in its life history. We have previously shown that C. elegans animals that experienced the developmentally arrested and stress resistant dauer stage (postdauers) retain a cellular memory of early-life stress that manifests during adulthood as genome-wide changes in gene expression, chromatin states, and altered life history traits. One consequence of developmental reprogramming in C. elegans postdauer adults is the downregulation of osm-9 TRPV channel gene expression in the ADL chemosensory neurons resulting in reduced avoidance to a pheromone component, ascr#3. This altered response to ascr#3 requires the principal effector of the somatic nuclear RNAi pathway, the Argonaute (AGO) NRDE-3. To investigate the role of the somatic nuclear RNAi pathway in regulating the developmental reprogramming of ADL due to early-life stress, we profiled the mRNA transcriptome of control and postdauer ADL in wild-type and nrde-3 mutant adults. We found 711 differentially expressed (DE) genes between control and postdauer ADL neurons, 90% of which are dependent upon NRDE-3. Additionally, we identified a conserved sequence that is enriched in the upstream regulatory sequences of the NRDE-3-dependent differentially expressed genes. Surprisingly, 214 of the ADL DE genes are considered "germline-expressed", including 21 genes encoding the Major Sperm Proteins and two genes encoding the sperm-specific PP1 phosphatases, GSP-3 and GSP-4. Loss of function mutations in gsp-3 resulted in both aberrant avoidance and attraction behaviors. We also show that an AGO pseudogene, Y49F6A.1 (wago-11), is expressed in ADL and is required for ascr#3 avoidance. Overall, our results suggest that small RNAs and reproductive genes program the ADL mRNA transcriptome during their developmental history and highlight a nexus between neuronal and reproductive networks in calibrating animal neuroplasticity.
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Affiliation(s)
- Maria C. Ow
- Biology Department, Syracuse University, Syracuse, NY, United States
| | | | - Abdul Rouf Dar
- Department of Chemistry, University of Florida, Gainesville, FL, United States
| | - Rebecca A. Butcher
- Department of Chemistry, University of Florida, Gainesville, FL, United States
| | - Sarah E. Hall
- Biology Department, Syracuse University, Syracuse, NY, United States
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Martin CG, Bent JS, Hill T, Topalidou I, Singhvi A. Epithelial UNC-23 limits mechanical stress to maintain glia-neuron architecture in C. elegans. Dev Cell 2024; 59:1668-1688.e7. [PMID: 38670103 PMCID: PMC11233253 DOI: 10.1016/j.devcel.2024.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 12/23/2023] [Accepted: 04/03/2024] [Indexed: 04/28/2024]
Abstract
For an organ to maintain correct architecture and function, its diverse cellular components must coordinate their size and shape. Although cell-intrinsic mechanisms driving homotypic cell-cell coordination are known, it is unclear how cell shape is regulated across heterotypic cells. We find that epithelial cells maintain the shape of neighboring sense-organ glia-neuron units in adult Caenorhabditis elegans (C. elegans). Hsp co-chaperone UNC-23/BAG2 prevents epithelial cell shape from deforming, and its loss causes head epithelia to stretch aberrantly during animal movement. In the sense-organ glia, amphid sheath (AMsh), this causes progressive fibroblast growth factor receptor (FGFR)-dependent disruption of the glial apical cytoskeleton. Resultant glial cell shape alteration causes concomitant shape change in glia-associated neuron endings. Epithelial UNC-23 maintenance of glia-neuron shape is specific both spatially, within a defined anatomical zone, and temporally, in a developmentally critical period. As all molecular components uncovered are broadly conserved across central and peripheral nervous systems, we posit that epithelia may similarly regulate glia-neuron architecture cross-species.
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Affiliation(s)
- Cecilia G Martin
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - James S Bent
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Tyler Hill
- Department of Biology, Brandeis University, Waltham, MA 02454, USA
| | - Irini Topalidou
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Aakanksha Singhvi
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Department of Biological Structure, University of Washington School of Medicine, Seattle, WA 98195, USA.
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Cheng H, Chen D, Li X, Al-Sheikh U, Duan D, Fan Y, Zhu L, Zeng W, Hu Z, Tong X, Zhao G, Zhang Y, Zou W, Duan S, Kang L. Phasic/tonic glial GABA differentially transduce for olfactory adaptation and neuronal aging. Neuron 2024; 112:1473-1486.e6. [PMID: 38447577 DOI: 10.1016/j.neuron.2024.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 11/11/2023] [Accepted: 02/06/2024] [Indexed: 03/08/2024]
Abstract
Phasic (fast) and tonic (sustained) inhibition of γ-aminobutyric acid (GABA) are fundamental for regulating day-to-day activities, neuronal excitability, and plasticity. However, the mechanisms and physiological functions of glial GABA transductions remain poorly understood. Here, we report that the AMsh glia in Caenorhabditis elegans exhibit both phasic and tonic GABAergic signaling, which distinctively regulate olfactory adaptation and neuronal aging. Through genetic screening, we find that GABA permeates through bestrophin-9/-13/-14 anion channels from AMsh glia, which primarily activate the metabolic GABAB receptor GBB-1 in the neighboring ASH sensory neurons. This tonic action of glial GABA regulates the age-associated changes of ASH neurons and olfactory responses via a conserved signaling pathway, inducing neuroprotection. In addition, the calcium-evoked, vesicular glial GABA release acts upon the ionotropic GABAA receptor LGC-38 in ASH neurons to regulate olfactory adaptation. These findings underscore the fundamental significance of glial GABA in maintaining healthy aging and neuronal stability.
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Affiliation(s)
- Hankui Cheng
- Department of Neurology of the Fourth Affiliated Hospital and School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Yiwu 322000, China; MOE Frontier Science Center for Brain Science and Brain machine Integration, NHC and CAMS Key Laboratory of Medical Neurobiology, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310053, China
| | - Du Chen
- Department of Neurology of the Fourth Affiliated Hospital and School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Yiwu 322000, China; MOE Frontier Science Center for Brain Science and Brain machine Integration, NHC and CAMS Key Laboratory of Medical Neurobiology, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310053, China
| | - Xiao Li
- Department of Neurology of the Fourth Affiliated Hospital and School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Yiwu 322000, China; MOE Frontier Science Center for Brain Science and Brain machine Integration, NHC and CAMS Key Laboratory of Medical Neurobiology, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310053, China
| | - Umar Al-Sheikh
- Department of Neurology of the Fourth Affiliated Hospital and School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Yiwu 322000, China; MOE Frontier Science Center for Brain Science and Brain machine Integration, NHC and CAMS Key Laboratory of Medical Neurobiology, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310053, China
| | - Duo Duan
- Department of Neurology of the Fourth Affiliated Hospital and School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Yiwu 322000, China; MOE Frontier Science Center for Brain Science and Brain machine Integration, NHC and CAMS Key Laboratory of Medical Neurobiology, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310053, China
| | - Yuedan Fan
- Department of Neurology of the Fourth Affiliated Hospital and School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Yiwu 322000, China; MOE Frontier Science Center for Brain Science and Brain machine Integration, NHC and CAMS Key Laboratory of Medical Neurobiology, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310053, China
| | - Linhui Zhu
- Department of Neurology of the Fourth Affiliated Hospital and School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Yiwu 322000, China; MOE Frontier Science Center for Brain Science and Brain machine Integration, NHC and CAMS Key Laboratory of Medical Neurobiology, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310053, China
| | - Wanxin Zeng
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Zhitao Hu
- Department of Neuroscience, City University of Hong Kong, Kowloon, China
| | - Xiajing Tong
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Guohua Zhao
- Department of Neurology of the Fourth Affiliated Hospital and School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Yiwu 322000, China
| | - Yongming Zhang
- Department of Ophthalmology of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu 322000, China
| | - Wenjuan Zou
- Department of Neurology of the Fourth Affiliated Hospital and School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Yiwu 322000, China; MOE Frontier Science Center for Brain Science and Brain machine Integration, NHC and CAMS Key Laboratory of Medical Neurobiology, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310053, China
| | - Shumin Duan
- MOE Frontier Science Center for Brain Science and Brain machine Integration, NHC and CAMS Key Laboratory of Medical Neurobiology, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310053, China
| | - Lijun Kang
- Department of Neurology of the Fourth Affiliated Hospital and School of Brain Science and Brain Medicine, Zhejiang University School of Medicine, Yiwu 322000, China; MOE Frontier Science Center for Brain Science and Brain machine Integration, NHC and CAMS Key Laboratory of Medical Neurobiology, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310053, China.
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Singhvi A, Shaham S, Rapti G. Glia Development and Function in the Nematode Caenorhabditis elegans. Cold Spring Harb Perspect Biol 2024:a041346. [PMID: 38565269 PMCID: PMC11445397 DOI: 10.1101/cshperspect.a041346] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
The nematode Caenorhabditis elegans is a powerful experimental setting for uncovering fundamental tenets of nervous system organization and function. Its nearly invariant and simple anatomy, coupled with a plethora of methodologies for interrogating single-gene functions at single-cell resolution in vivo, have led to exciting discoveries in glial cell biology and mechanisms of glia-neuron interactions. Findings over the last two decades reinforce the idea that insights from C. elegans can inform our understanding of glial operating principles in other species. Here, we summarize the current state-of-the-art, and describe mechanistic insights that have emerged from a concerted effort to understand C. elegans glia. The remarkable acceleration in the pace of discovery in recent years paints a portrait of striking molecular complexity, exquisite specificity, and functional heterogeneity among glia. Glial cells affect nearly every aspect of nervous system development and function, from generating neurons, to promoting neurite formation, to animal behavior, and to whole-animal traits, including longevity. We discuss emerging questions where C. elegans is poised to fill critical knowledge gaps in our understanding of glia biology.
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Affiliation(s)
- Aakanksha Singhvi
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, Washington 98109, USA
- Department of Biological Structure, University of Washington School of Medicine, Seattle, Washington 98195, USA
| | - Shai Shaham
- Laboratory of Developmental Genetics, The Rockefeller University, New York, New York 10065, USA
| | - Georgia Rapti
- Developmental Biology Unit, European Molecular Biology Laboratory, Heidelberg 69117, Germany
- Epigenetics and Neurobiology Unit, European Molecular Biology Laboratory, Monterotondo, Rome 00015, Italy
- Interdisciplinary Center of Neurosciences, Heidelberg University, Heidelberg, Germany
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Ray S, Gurung P, Manning RS, Kravchuk AA, Singhvi A. Neuron cilia restrain glial KCC-3 to a microdomain to regulate multisensory processing. Cell Rep 2024; 43:113844. [PMID: 38421867 PMCID: PMC11296322 DOI: 10.1016/j.celrep.2024.113844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 12/15/2023] [Accepted: 02/06/2024] [Indexed: 03/02/2024] Open
Abstract
Glia interact with multiple neurons, but it is unclear whether their interactions with each neuron are different. Our interrogation at single-cell resolution reveals that a single glial cell exhibits specificity in its interactions with different contacting neurons. Briefly, C. elegans amphid sheath (AMsh) glia apical-like domains contact 12 neuron-endings. At these ad-neuronal membranes, AMsh glia localize the K/Cl transporter KCC-3 to a microdomain exclusively around the thermosensory AFD neuron to regulate its properties. Glial KCC-3 is transported to ad-neuronal regions, where distal cilia of non-AFD glia-associated chemosensory neurons constrain it to a microdomain at AFD-contacting glial membranes. Aberrant KCC-3 localization impacts both thermosensory (AFD) and chemosensory (non-AFD) neuron properties. Thus, neurons can interact non-synaptically through a shared glial cell by regulating microdomain localization of its cues. As AMsh and glia across species compartmentalize multiple cues like KCC-3, we posit that this may be a broadly conserved glial mechanism that modulates information processing across multimodal circuits.
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Affiliation(s)
- Sneha Ray
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Neuroscience Graduate Program, University of Washington, Seattle, WA 98195, USA
| | - Pralaksha Gurung
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Neuroscience Graduate Program, University of Washington, Seattle, WA 98195, USA
| | - R Sean Manning
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Alexandra A Kravchuk
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Aakanksha Singhvi
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Department of Biological Structure, University of Washington School of Medicine, Seattle, WA 98195, USA.
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Stefanakis N, Jiang J, Liang Y, Shaham S. LET-381/FoxF and its target UNC-30/Pitx2 specify and maintain the molecular identity of C. elegans mesodermal glia that regulate motor behavior. EMBO J 2024; 43:956-992. [PMID: 38360995 PMCID: PMC10943081 DOI: 10.1038/s44318-024-00049-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 01/22/2024] [Accepted: 01/26/2024] [Indexed: 02/17/2024] Open
Abstract
While most glial cell types in the central nervous system (CNS) arise from neuroectodermal progenitors, some, like microglia, are mesodermally derived. To understand mesodermal glia development and function, we investigated C. elegans GLR glia, which envelop the brain neuropil and separate it from the circulatory system cavity. Transcriptome analysis shows that GLR glia combine astrocytic and endothelial characteristics, which are relegated to separate cell types in vertebrates. Combined fate acquisition is orchestrated by LET-381/FoxF, a fate-specification/maintenance transcription factor also expressed in glia and endothelia of other animals. Among LET-381/FoxF targets, the UNC-30/Pitx2 transcription factor controls GLR glia morphology and represses alternative mesodermal fates. LET-381 and UNC-30 co-expression in naive cells is sufficient for GLR glia gene expression. GLR glia inactivation by ablation or let-381 mutation disrupts locomotory behavior and promotes salt-induced paralysis, suggesting brain-neuropil activity dysregulation. Our studies uncover mechanisms of mesodermal glia development and show that like neuronal differentiation, glia differentiation requires autoregulatory terminal selector genes that define and maintain the glial fate.
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Affiliation(s)
- Nikolaos Stefanakis
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Jessica Jiang
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Yupu Liang
- Research Bioinformatics, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
- Alexion Pharmaceuticals, Boston, MA, 02135, USA
| | - Shai Shaham
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA.
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Cebul ER, Marivin A, Wexler LR, Perrat PN, Bénard CY, Garcia-Marcos M, Heiman MG. SAX-7/L1CAM acts with the adherens junction proteins MAGI-1, HMR-1/Cadherin, and AFD-1/Afadin to promote glial-mediated dendrite extension. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.11.575259. [PMID: 38260503 PMCID: PMC10802611 DOI: 10.1101/2024.01.11.575259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Adherens junctions (AJs) are a fundamental organizing structure for multicellular life. Although AJs are studied mainly in epithelia, their core function - stabilizing cell contacts by coupling adhesion molecules to the cytoskeleton - is important in diverse tissues. We find that two C. elegans sensory neurons, URX and BAG, require conserved AJ proteins for dendrite morphogenesis. We previously showed that URX and BAG dendrites attach to the embryonic nose via the adhesion molecule SAX-7/L1CAM, acting both in neurons and glia, and then extend by stretch during embryo elongation. Here, we find that a PDZ-binding motif (PB) in the SAX-7 cytoplasmic tail acts with other interaction motifs to promote dendrite extension. Using pull-down assays, we find that the SAX-7 PB binds the multi-PDZ scaffolding protein MAGI-1, which bridges it to the cadherin-catenin complex protein HMP-2/β-catenin. Using cell-specific rescue and depletion, we find that both MAGI-1 and HMR-1/Cadherin act in glia to non-autonomously promote dendrite extension. Double mutant analysis indicates that each protein can act independently of SAX-7, suggesting a multivalent adhesion complex. The SAX-7 PB motif also binds AFD-1/Afadin, loss of which further enhances sax-7 BAG dendrite defects. As MAGI-1, HMR-1, and AFD-1 are all found in epithelial AJs, we propose that an AJ-like complex in glia promotes dendrite extension.
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Affiliation(s)
- Elizabeth R. Cebul
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA 02115, USA
- Present address: Section on Sensory Cell Development and Function, National Institute on Deafness and Other Communication Disorders, Bethesda, MD 20892, USA
| | - Arthur Marivin
- Department of Biochemistry & Cell Biology, Chobanian & Avedisian School of Medicine, Boston University, Boston, MA 02118, USA, Boston University School of Medicine, Boston, MA 02118, USA
| | - Leland R. Wexler
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Paola N. Perrat
- Department of Biological Sciences, CERMO-FC Research Center, Universite du Québec à Montréal, Montreál, QC, Canada
| | - Claire Y. Bénard
- Department of Biological Sciences, CERMO-FC Research Center, Universite du Québec à Montréal, Montreál, QC, Canada
| | - Mikel Garcia-Marcos
- Department of Biochemistry & Cell Biology, Chobanian & Avedisian School of Medicine, Boston University, Boston, MA 02118, USA, Boston University School of Medicine, Boston, MA 02118, USA
- Department of Biology, College of Arts & Sciences, Boston University, Boston, MA 02115, USA
| | - Maxwell G. Heiman
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA 02115, USA
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10
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Purice MD, Severs LJ, Singhvi A. Glia in Invertebrate Models: Insights from Caenorhabditis elegans. ADVANCES IN NEUROBIOLOGY 2024; 39:19-49. [PMID: 39190070 DOI: 10.1007/978-3-031-64839-7_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/28/2024]
Abstract
Glial cells modulate brain development, function, and health across all bilaterian animals, and studies in the past two decades have made rapid strides to uncover the underlying molecular mechanisms of glial functions. The nervous system of the invertebrate genetic model Caenorhabditis elegans (C. elegans) has small cell numbers with invariant lineages, mapped connectome, easy genetic manipulation, and a short lifespan, and the animal is also optically transparent. These characteristics are revealing C. elegans to be a powerful experimental platform for studying glial biology. This chapter discusses studies in C. elegans that add to our understanding of how glia modulate adult neural functions, and thereby animal behaviors, as well as emerging evidence of their roles as autonomous sensory cells. The rapid molecular and cellular advancements in understanding C. elegans glia in recent years underscore the utility of this model in studies of glial biology. We conclude with a perspective on future research avenues for C. elegans glia that may readily contribute molecular mechanistic insights into glial functions in the nervous system.
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Affiliation(s)
- Maria D Purice
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Liza J Severs
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Aakanksha Singhvi
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA, USA.
- Department of Biological Structure, University of Washington School of Medicine, Seattle, WA, USA.
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11
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Varandas KC, Hodges BM, Lubeck L, Farinas A, Liang Y, Lu Y, Shaham S. Glia detect and mount a protective response to loss of dendrite substructure integrity in C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.16.567404. [PMID: 38014226 PMCID: PMC10680744 DOI: 10.1101/2023.11.16.567404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Neurons have elaborate structures that determine their connectivity and functions. Changes in neuronal structure accompany learning and memory formation and are hallmarks of neurological disease. Here we show that glia monitor dendrite structure and respond to dendrite perturbation. In C. elegans mutants with defective sensory-organ dendrite cilia, adjacent glia accumulate extracellular matrix-laden vesicles, secrete excess matrix around cilia, alter gene expression, and change their secreted protein repertoire. Inducible cilia disruption reveals that this response is acute. DGS-1, a 7-transmembrane domain neuronal protein, and FIG-1, a multifunctional thrombospondin-domain glial protein, are required for glial detection of cilia integrity, and exhibit mutually-dependent localization to and around cilia, respectively. While inhibiting glial secretion disrupts dendritic cilia properties, hyperactivating the glial response protects against dendrite damage. Our studies uncover a homeostatic protective dendrite-glia interaction and suggest that similar signaling occurs at other sensory structures and at synapses, which resemble sensory organs in architecture and molecules.
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12
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Stefanakis N, Jiang J, Liang Y, Shaham S. LET-381/FoxF and UNC-30/Pitx2 control the development of C. elegans mesodermal glia that regulate motor behavior. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.23.563501. [PMID: 37961181 PMCID: PMC10634723 DOI: 10.1101/2023.10.23.563501] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
While most CNS glia arise from neuroectodermal progenitors, some, like microglia, are mesodermally derived. To understand mesodermal glia development and function, we investigated C. elegans GLR glia, which ensheath the brain neuropil and separate it from the circulatory-system cavity. Transcriptome analysis suggests GLR glia merge astrocytic and endothelial characteristics relegated to separate cell types in vertebrates. Combined fate acquisition is orchestrated by LET-381/FoxF, a fate-specification/maintenance transcription factor expressed in glia and endothelia of other animals. Among LET-381/FoxF targets, UNC-30/Pitx2 transcription factor controls GLR glia morphology and represses alternative mesodermal fates. LET-381 and UNC-30 co-expression in naïve cells is sufficient for GLR glia gene expression. GLR glia inactivation by ablation or let-381 mutation disrupts locomotory behavior and induces salt hypersensitivity, suggesting brain-neuropil activity dysregulation. Our studies uncover mechanisms of mesodermal glia development and show that like neurons, glia differentiation requires autoregulatory terminal selector genes that define and maintain the glial fate.
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13
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Purice MD, Quitevis EJ, Manning RS, Severs LJ, Tran NT, Sorrentino V, Setty M, Singhvi A. Molecular heterogeneity of C. elegans glia across sexes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.21.533668. [PMID: 36993469 PMCID: PMC10055349 DOI: 10.1101/2023.03.21.533668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
Abstract
A comprehensive description of nervous system function, and sex dimorphism within, is incomplete without clear assessment of the diversity of its component cell types, neurons and glia. C. elegans has an invariant nervous system with the first mapped connectome of a multicellular organism and single-cell atlas of component neurons. Here we present single nuclear RNA-seq evaluation of glia across the entire adult C. elegans nervous system, including both sexes. Machine learning models enabled us to identify both sex-shared and sex-specific glia and glial subclasses. We have identified and validated molecular markers in silico and in vivo for these molecular subcategories. Comparative analytics also reveals previously unappreciated molecular heterogeneity in anatomically identical glia between and within sexes, indicating consequent functional heterogeneity. Furthermore, our datasets reveal that while adult C. elegans glia express neuropeptide genes, they lack the canonical unc-31/CAPS-dependent dense core vesicle release machinery. Thus, glia employ alternate neuromodulator processing mechanisms. Overall, this molecular atlas, available at www.wormglia.org, reveals rich insights into heterogeneity and sex dimorphism in glia across the entire nervous system of an adult animal.
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Affiliation(s)
- Maria D. Purice
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
| | - Elgene J.A. Quitevis
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
- Herbold Computational Biology Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
| | - R. Sean Manning
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
| | - Liza J. Severs
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
| | - Nina-Tuyen Tran
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
| | - Violet Sorrentino
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
| | - Manu Setty
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
- Herbold Computational Biology Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
| | - Aakanksha Singhvi
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
- Department of Biological Structure, University of Washington School of Medicine, WA 98195
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14
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Ray S, Gurung P, Manning RS, Kravchuk A, Singhvi A. Neuron cilia constrain glial regulators to microdomains around distal neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.18.533255. [PMID: 36993507 PMCID: PMC10055228 DOI: 10.1101/2023.03.18.533255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Each glia interacts with multiple neurons, but the fundamental logic of whether it interacts with all equally remains unclear. We find that a single sense-organ glia modulates different contacting neurons distinctly. To do so, it partitions regulatory cues into molecular microdomains at specific neuron contact-sites, at its delimited apical membrane. For one glial cue, K/Cl transporter KCC-3, microdomain-localization occurs through a two-step, neuron-dependent process. First, KCC-3 shuttles to glial apical membranes. Second, some contacting neuron cilia repel it, rendering it microdomain-localized around one distal neuron-ending. KCC-3 localization tracks animal aging, and while apical localization is sufficient for contacting neuron function, microdomain-restriction is required for distal neuron properties. Finally, we find the glia regulates its microdomains largely independently. Together, this uncovers that glia modulate cross-modal sensor processing by compartmentalizing regulatory cues into microdomains. Glia across species contact multiple neurons and localize disease-relevant cues like KCC-3. Thus, analogous compartmentalization may broadly drive how glia regulate information processing across neural circuits.
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Affiliation(s)
- Sneha Ray
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
- Neuroscience Graduate Program, University of Washington, Seattle, WA
| | - Pralaksha Gurung
- Neuroscience Graduate Program, University of Washington, Seattle, WA
| | - R. Sean Manning
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
| | - Alexandra Kravchuk
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
- University of Washington School of Medicine, WA 98195
| | - Aakanksha Singhvi
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
- Department of Biological Structure, University of Washington School of Medicine, WA 98195
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15
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Wang L, Graziano B, Encalada N, Fernandez-Abascal J, Kaplan DH, Bianchi L. Glial regulators of ions and solutes required for specific chemosensory functions in Caenorhabditis elegans. iScience 2022; 25:105684. [PMID: 36567707 PMCID: PMC9772852 DOI: 10.1016/j.isci.2022.105684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 09/11/2022] [Accepted: 11/24/2022] [Indexed: 12/03/2022] Open
Abstract
Glia and accessory cells regulate the microenvironment around neurons and primary sensory cells. However, the impact of specific glial regulators of ions and solutes on functionally diverse primary cells is poorly understood. Here, we systemically investigate the requirement of ion channels and transporters enriched in Caenorhabditis elegans Amsh glia for the function of chemosensory neurons. Although Amsh glia ablated worms show reduced function of ASH, AWC, AWA, and ASE neurons, we show that the loss of glial enriched ion channels and transporters impacts these neurons differently, with nociceptor ASH being the most affected. Furthermore, our analysis underscores the importance of K+, Cl-, and nucleoside homeostasis in the Amphid sensory organ and uncovers the contribution of glial genes implicated in neurological disorders. Our findings build a unique fingerprint of each glial enriched ion channel and transporter and may provide insights into the function of supporting cells of mammalian sensory organs.
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Affiliation(s)
- Lei Wang
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Rm 5133 Rosenstiel Building, 1600 NW 10 Avenue, Miami, FL33136, USA
| | - Bianca Graziano
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Rm 5133 Rosenstiel Building, 1600 NW 10 Avenue, Miami, FL33136, USA
| | - Nicole Encalada
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Rm 5133 Rosenstiel Building, 1600 NW 10 Avenue, Miami, FL33136, USA
| | - Jesus Fernandez-Abascal
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Rm 5133 Rosenstiel Building, 1600 NW 10 Avenue, Miami, FL33136, USA
| | - Daryn H. Kaplan
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Rm 5133 Rosenstiel Building, 1600 NW 10 Avenue, Miami, FL33136, USA
| | - Laura Bianchi
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Rm 5133 Rosenstiel Building, 1600 NW 10 Avenue, Miami, FL33136, USA
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16
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Clupper M, Gill R, Elsayyid M, Touroutine D, Caplan JL, Tanis JE. Kinesin-2 motors differentially impact biogenesis of extracellular vesicle subpopulations shed from sensory cilia. iScience 2022; 25:105262. [PMID: 36304122 PMCID: PMC9593189 DOI: 10.1016/j.isci.2022.105262] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 07/13/2022] [Accepted: 09/26/2022] [Indexed: 01/21/2023] Open
Abstract
Extracellular vesicles (EVs) are bioactive lipid-bilayer enclosed particles released from nearly all cells. One specialized site for EV shedding is the primary cilium. Here, we discover the conserved ion channel CLHM-1 as a ciliary EV cargo. Imaging of EVs released from sensory neuron cilia of Caenorhabditis elegans expressing fluorescently tagged CLHM-1 and TRP polycystin-2 channel PKD-2 shows enrichment of these cargoes in distinct EV subpopulations that are differentially shed in response to mating partner availability. PKD-2 alone is present in EVs shed from the cilium distal tip, whereas CLHM-1 EVs bud from a secondary site(s), including the ciliary base. Heterotrimeric and homodimeric kinesin-2 motors have discrete impacts on PKD-2 and CLHM-1 colocalization in both cilia and EVs. Total loss of kinesin-2 activity decreases shedding of PKD-2 but not CLHM-1 EVs. Our data demonstrate that anterograde intraflagellar transport is required for selective enrichment of protein cargoes into heterogeneous EVs with different signaling potentials.
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Affiliation(s)
- Michael Clupper
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Rachael Gill
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Malek Elsayyid
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Denis Touroutine
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Jeffrey L. Caplan
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
- Department of Plant and Soil Sciences, University of Delaware, Newark, DE 19716, USA
| | - Jessica E. Tanis
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
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17
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Bolatto C, Nieves S, Reyes A, Olivera-Bravo S, Cambiazo V. Patched-Related Is Required for Proper Development of Embryonic Drosophila Nervous System. Front Neurosci 2022; 16:920670. [PMID: 36081658 PMCID: PMC9446084 DOI: 10.3389/fnins.2022.920670] [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: 04/14/2022] [Accepted: 06/24/2022] [Indexed: 11/19/2022] Open
Abstract
Patched-related (Ptr), classified primarily as a neuroectodermal gene, encodes a protein with predicted topology and domain organization closely related to those of Patched (Ptc), the canonical receptor of the Hedgehog (Hh) pathway. To investigate the physiological function of Ptr in the developing nervous system, Ptr null mutant embryos were immunolabeled and imaged under confocal microscopy. These embryos displayed severe alterations in the morphology of the primary axonal tracts, reduced number, and altered distribution of the Repo-positive glia as well as peripheral nervous system defects. Most of these alterations were recapitulated by downregulating Ptr expression, specifically in embryonic nerve cells. Because similar nervous system phenotypes have been observed in hh and ptc mutant embryos, we evaluated the Ptr participation in the Hh pathway by performing cell-based reporter assays. Clone-8 cells were transfected with Ptr-specific dsRNA or a Ptr DNA construct and assayed for changes in Hh-mediated induction of a luciferase reporter. The results obtained suggest that Ptr could act as a negative regulator of Hh signaling. Furthermore, co-immunoprecipitation assays from cell culture extracts premixed with a conditioned medium revealed a direct interaction between Ptr and Hh. Moreover, in vivo Ptr overexpression in the domain of the imaginal wing disc where Engrailed and Ptc coexist produced wing phenotypes at the A/P border. Thus, these results strongly suggest that Ptr plays a crucial role in nervous system development and appears to be a negative regulator of the Hh pathway.
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Affiliation(s)
- Carmen Bolatto
- Developmental Biology Laboratory, Histology and Embryology Department, Faculty of Medicine, Universidad de la República (UdelaR), Montevideo, Uruguay
- Cell and Molecular Neurobiology Laboratory, Computational and Integrative Neuroscience (NCIC) Department, Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), Montevideo, Uruguay
- *Correspondence: Carmen Bolatto
| | - Sofía Nieves
- Developmental Biology Laboratory, Histology and Embryology Department, Faculty of Medicine, Universidad de la República (UdelaR), Montevideo, Uruguay
| | - Agustina Reyes
- Developmental Biology Laboratory, Histology and Embryology Department, Faculty of Medicine, Universidad de la República (UdelaR), Montevideo, Uruguay
| | - Silvia Olivera-Bravo
- Cell and Molecular Neurobiology Laboratory, Computational and Integrative Neuroscience (NCIC) Department, Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), Montevideo, Uruguay
| | - Verónica Cambiazo
- Bioinformatic and Gene Expression Laboratory, Institute of Nutrition and Food Technology (INTA)-Universidad de Chile and Millennium Institute Center for Genome Regulation (CRG), Santiago, Chile
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18
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Pandey P, Kaur G, Babu K. Crosstalk between neurons and glia through G-protein coupled receptors: Insights from Caenorhabditis elegans. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2022; 193:119-144. [PMID: 36357074 DOI: 10.1016/bs.pmbts.2022.06.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The past decades have witnessed a dogmatic shift from glia as supporting cells in the nervous system to their active roles in neurocentric functions. Neurons and glia communicate and show bidirectional responses through tripartite synapses. Studies across species indicate that neurotransmitters released by neurons are perceived by glial receptors, which allow for gliotransmitter release. These gliotransmitters can result in activation of neurons via neuronal GPCR receptors. However, studies of these molecular interactions are in their infancy. Caenorhabditis elegans has a conserved neuron-glia architectural repertoire with molecular and functional resemblance to mammals. Further, glia in C. elegans can be manipulated through ablation and mutations allowing for deciphering of glial dependent processes in vivo at single glial resolutions. Here, we will review recent findings from vertebrate and invertebrate organisms with a focus on how C. elegans can be used to advance our understanding of neuron-glia interactions through GPCRs.
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Affiliation(s)
- Pratima Pandey
- Indian Institute of Science Education and Research, Mohali, Punjab, India.
| | - Gazaldeep Kaur
- National Agri-Food Biotechnology Institute, Mohali, Punjab, India
| | - Kavita Babu
- Indian Institute of Science, Bangalore, Karnataka, India.
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19
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Rapti G. Open Frontiers in Neural Cell Type Investigations; Lessons From Caenorhabditis elegans and Beyond, Toward a Multimodal Integration. Front Neurosci 2022; 15:787753. [PMID: 35321480 PMCID: PMC8934944 DOI: 10.3389/fnins.2021.787753] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 12/30/2021] [Indexed: 11/13/2022] Open
Abstract
Nervous system cells, the building blocks of circuits, have been studied with ever-progressing resolution, yet neural circuits appear still resistant to schemes of reductionist classification. Due to their sheer numbers, complexity and diversity, their systematic study requires concrete classifications that can serve reduced dimensionality, reproducibility, and information integration. Conventional hierarchical schemes transformed through the history of neuroscience by prioritizing criteria of morphology, (electro)physiological activity, molecular content, and circuit function, influenced by prevailing methodologies of the time. Since the molecular biology revolution and the recent advents in transcriptomics, molecular profiling gains ground toward the classification of neurons and glial cell types. Yet, transcriptomics entails technical challenges and more importantly uncovers unforeseen spatiotemporal heterogeneity, in complex and simpler nervous systems. Cells change states dynamically in space and time, in response to stimuli or throughout their developmental trajectory. Mapping cell type and state heterogeneity uncovers uncharted terrains in neurons and especially in glial cell biology, that remains understudied in many aspects. Examining neurons and glial cells from the perspectives of molecular neuroscience, physiology, development and evolution highlights the advantage of multifaceted classification schemes. Among the amalgam of models contributing to neuroscience research, Caenorhabditis elegans combines nervous system anatomy, lineage, connectivity and molecular content, all mapped at single-cell resolution, and can provide valuable insights for the workflow and challenges of the multimodal integration of cell type features. This review reflects on concepts and practices of neuron and glial cells classification and how research, in C. elegans and beyond, guides nervous system experimentation through integrated multidimensional schemes. It highlights underlying principles, emerging themes, and open frontiers in the study of nervous system development, regulatory logic and evolution. It proposes unified platforms to allow integrated annotation of large-scale datasets, gene-function studies, published or unpublished findings and community feedback. Neuroscience is moving fast toward interdisciplinary, high-throughput approaches for combined mapping of the morphology, physiology, connectivity, molecular function, and the integration of information in multifaceted schemes. A closer look in mapped neural circuits and understudied terrains offers insights for the best implementation of these approaches.
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20
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Fernandez-Abascal J, Bianchi L. The ClC Cl - channel CLH-1 mediates HCO 3 - efflux from the amphid sheath glia in C. elegans. MICROPUBLICATION BIOLOGY 2022; 2022:10.17912/micropub.biology.000510. [PMID: 35047763 PMCID: PMC8758995 DOI: 10.17912/micropub.biology.000510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 12/29/2021] [Accepted: 01/03/2022] [Indexed: 11/21/2022]
Abstract
Cellular function is regulated by the concentration of intracellular and extracellular ions, including pH. Ion channels and transporters that mediate the flux/transport of protons and bicarbonate (HCO3 -) are the chief regulators of pH. In the nervous system, due to their high electrical activity, neurons tend to produce and excrete large amounts of acids. On the contrary, glial cells have been proposed to be key contributors of pH buffering. We published that the Cl-/HCO3 - permeable channel CLH-1 mediates intracellular pH buffering of C. elegans Amphid sheath (AMsh) glia at baseline. We show here that, under physiological conditions, clh-1 knock out worms show reduced HCO3 - extrusion from AMsh glia, suggesting that CLH-1 may help prevent cellular alkalinization. This function becomes even more apparent when animals are grown on plates enriched with HCO3 -. We speculate that CLH-1 might function as a regulator of extracellular pH.
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Affiliation(s)
- Jesus Fernandez-Abascal
- Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, 1600 NW 10th Ave, Mimi, FL, USA
| | - Laura Bianchi
- Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, 1600 NW 10th Ave, Mimi, FL, USA
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21
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Wallace SW, Lizzappi MC, Magemizoğlu E, Hur H, Liang Y, Shaham S. Nuclear hormone receptors promote gut and glia detoxifying enzyme induction and protect C. elegans from the mold P. brevicompactum. Cell Rep 2021; 37:110166. [PMID: 34965433 PMCID: PMC8733895 DOI: 10.1016/j.celrep.2021.110166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 10/19/2021] [Accepted: 12/02/2021] [Indexed: 11/03/2022] Open
Abstract
Animals encounter microorganisms in their habitats, adapting physiology and behavior accordingly. The nematode Caenorhabditis elegans is found in microbe-rich environments; however, its responses to fungi are not extensively studied. Here, we describe interactions of C. elegans and Penicillium brevicompactum, an ecologically relevant mold. Transcriptome studies reveal that co-culture upregulates stress response genes, including xenobiotic-metabolizing enzymes (XMEs), in C. elegans intestine and AMsh glial cells. The nuclear hormone receptors (NHRs) NHR-45 and NHR-156 are induction regulators, and mutants that cannot induce XMEs in the intestine when exposed to P. brevicompactum experience mitochondrial stress and exhibit developmental defects. Different C. elegans wild isolates harbor sequence polymorphisms in nhr-156, resulting in phenotypic diversity in AMsh glia responses to microbe exposure. We propose that P. brevicompactum mitochondria-targeting mycotoxins are deactivated by intestinal detoxification, allowing tolerance to moldy environments. Our studies support the idea that C. elegans NHRs may be regulated by environmental cues.
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Affiliation(s)
- Sean W Wallace
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Malcolm C Lizzappi
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Elif Magemizoğlu
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Hong Hur
- CCTS Research Bioinformatics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Yupu Liang
- CCTS Research Bioinformatics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Shai Shaham
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
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22
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Charlton-Perkins MA, Friedrich M, Cook TA. Semper's cells in the insect compound eye: Insights into ocular form and function. Dev Biol 2021; 479:126-138. [PMID: 34343526 PMCID: PMC8410683 DOI: 10.1016/j.ydbio.2021.07.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 07/26/2021] [Accepted: 07/28/2021] [Indexed: 11/28/2022]
Abstract
The arthropod compound eye represents one of two major eye types in the animal kingdom and has served as an essential experimental paradigm for defining fundamental mechanisms underlying sensory organ formation, function, and maintenance. One of the most distinguishing features of the compound eye is the highly regular array of lens facets that define individual eye (ommatidial) units. These lens facets are produced by a deeply conserved quartet of cuticle-secreting cells, called Semper cells (SCs). Also widely known as cone cells, SCs were originally identified for their secretion of the dioptric system, i.e. the corneal lens and underlying crystalline cones. Additionally, SCs are now known to execute a diversity of patterning and glial functions in compound eye development and maintenance. Here, we present an integrated account of our current knowledge of SC multifunctionality in the Drosophila compound eye, highlighting emerging gene regulatory modules that may drive the diverse roles for these cells. Drawing comparisons with other deeply conserved retinal glia in the vertebrate single lens eye, this discussion speaks to glial cell origins and opens new avenues for understanding sensory system support programs.
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Affiliation(s)
- Mark A Charlton-Perkins
- Department of Paediatrics, Wellcome-MRC Stem Cell Institute, Jeffrey Cheah Biomedical Centre, University of Cambridge, Puddicombe Way, Cambridge, CB2 0AW, United Kingdom
| | - Markus Friedrich
- Department of Biological Sciences, Wayne State University, 5047 Gullen Mall, Detroit, MI, 48202, USA; Department of Ophthalmological, Visual, and Anatomical Sciences, Wayne State University, School of Medicine, 540 East Canfield Avenue, Detroit, MI, 48201, USA
| | - Tiffany A Cook
- Department of Ophthalmological, Visual, and Anatomical Sciences, Wayne State University, School of Medicine, 540 East Canfield Avenue, Detroit, MI, 48201, USA; Center of Molecular Medicine and Genetics, Wayne State University School of Medicine, 540 East Canfield Avenue, Detroit, MI, 48201, USA.
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23
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Mizeracka K, Rogers JM, Rumley JD, Shaham S, Bulyk ML, Murray JI, Heiman MG. Lineage-specific control of convergent differentiation by a Forkhead repressor. Development 2021; 148:272306. [PMID: 34423346 DOI: 10.1242/dev.199493] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 08/17/2021] [Indexed: 12/14/2022]
Abstract
During convergent differentiation, multiple developmental lineages produce a highly similar or identical cell type. However, few molecular players that drive convergent differentiation are known. Here, we show that the C. elegans Forkhead transcription factor UNC-130 is required in only one of three convergent lineages that produce the same glial cell type. UNC-130 acts transiently as a repressor in progenitors and newly-born terminal cells to allow the proper specification of cells related by lineage rather than by cell type or function. Specification defects correlate with UNC-130:DNA binding, and UNC-130 can be functionally replaced by its human homolog, the neural crest lineage determinant FoxD3. We propose that, in contrast to terminal selectors that activate cell type-specific transcriptional programs in terminally differentiating cells, UNC-130 acts early and specifically in one convergent lineage to produce a cell type that also arises from molecularly distinct progenitors in other lineages.
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Affiliation(s)
- Karolina Mizeracka
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA.,Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA
| | - Julia M Rogers
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.,Committee on Higher Degrees in Biophysics, Harvard University, Cambridge, MA 02138, USA
| | - Jonathan D Rumley
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Shai Shaham
- The Rockefeller University, New York, NY 10065, USA
| | - Martha L Bulyk
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.,Committee on Higher Degrees in Biophysics, Harvard University, Cambridge, MA 02138, USA.,Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - John I Murray
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Maxwell G Heiman
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA.,Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA
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24
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Razzauti A, Laurent P. Ectocytosis prevents accumulation of ciliary cargo in C. elegans sensory neurons. eLife 2021; 10:67670. [PMID: 34533135 PMCID: PMC8492061 DOI: 10.7554/elife.67670] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 09/16/2021] [Indexed: 12/13/2022] Open
Abstract
Cilia are sensory organelles protruding from cell surfaces. Release of extracellular vesicles (EVs) from cilia was previously observed in mammals, Chlamydomonas, and in male Caenorhabditis elegans. Using the EV marker TSP-6 (an ortholog of mammalian CD9) and other ciliary receptors, we show that EVs are formed from ciliated sensory neurons in C. elegans hermaphrodites. Release of EVs is observed from two ciliary locations: the cilia tip and/or periciliary membrane compartment (PCMC). Outward budding of EVs from the cilia tip leads to their release into the environment. EVs' budding from the PCMC is concomitantly phagocytosed by the associated glial cells. To maintain cilia composition, a tight regulation of cargo import and removal is achieved by the action of intra-flagellar transport (IFT). Unbalanced IFT due to cargo overexpression or mutations in the IFT machinery leads to local accumulation of ciliary proteins. Disposal of excess ciliary proteins via EVs reduces their local accumulation and exports them to the environment and/or to the glia associated to these ciliated neurons. We suggest that EV budding from cilia subcompartments acts as a safeguard mechanism to remove deleterious excess of ciliary material.
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Affiliation(s)
- Adria Razzauti
- Laboratory of Neurophysiology, ULB Neuroscience Institute (UNI), Université Libre de Bruxelles(ULB), Brussels, Belgium
| | - Patrick Laurent
- Laboratory of Neurophysiology, ULB Neuroscience Institute (UNI), Université Libre de Bruxelles(ULB), Brussels, Belgium
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25
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Rapti G. A perspective on C. elegans neurodevelopment: from early visionaries to a booming neuroscience research. J Neurogenet 2021; 34:259-272. [PMID: 33446023 DOI: 10.1080/01677063.2020.1837799] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The formation of the nervous system and its striking complexity is a remarkable feat of development. C. elegans served as a unique model to dissect the molecular events in neurodevelopment, from its early visionaries to the current booming neuroscience community. Soon after being introduced as a model, C. elegans was mapped at the level of genes, cells, and synapses, providing the first metazoan with a complete cell lineage, sequenced genome, and connectome. Here, I summarize mechanisms underlying C. elegans neurodevelopment, from the generation and diversification of neural components to their navigation and connectivity. I point out recent noteworthy findings in the fields of glia biology, sex dimorphism and plasticity in neurodevelopment, highlighting how current research connects back to the pioneering studies by Brenner, Sulston and colleagues. Multifaceted investigations in model organisms, connecting genes to cell function and behavior, expand our mechanistic understanding of neurodevelopment while allowing us to formulate emerging questions for future discoveries.
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Affiliation(s)
- Georgia Rapti
- European Molecular Biology Laboratory, Unit of Developmental Biology, Heidelberg, Germany
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26
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Bowles SN, Johnson CM. Inferences of glia-mediated control in Caenorhabditis elegans. J Neurosci Res 2021; 99:1191-1206. [PMID: 33559247 PMCID: PMC8005477 DOI: 10.1002/jnr.24803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 01/12/2021] [Indexed: 12/22/2022]
Abstract
Astrocytes modulate synaptic transmission; yet, it remains unclear how glia influence complex behaviors. Here, we explore the effects of Caenorhabditis elegans astrocyte-like cephalic glia (CEPglia ) and the glia-specific bHLH transcription factor HLH-17 on mating behavior and the defecation motor program (DMP). In C. elegans, male mating has been explicitly described through the male tail circuit and is characterized by coordination of multiple independent behaviors to ensure that copulation is achieved. Furthermore, the sex-specific male mating circuitry shares similar components with the DMP, which is complex and rhythmic, and requires a fixed sequence of behaviors to be activated periodically. We found that loss of CEPglia reduced persistence in executing mating behaviors and hindered copulation, while males that lacked HLH-17 demonstrated repetitive prodding behavior that increased the time spent in mating but did not hinder copulation. During the DMP, we found that posterior body wall contractions (pBocs) and enteric muscle contractions (EMCs) were differentially affected by loss of HLH-17 or CEPglia in males and hermaphrodites. pBocs and EMCs required HLH-17 activity in both sexes, whereas loss of CEPglia alone did not affect DMP in males. Our data suggest that CEPglia mediate complex behaviors by signaling to the GABAergic DVB neuron, and that HLH-17 activity influences those discrete steps within those behaviors. Collectively, these data provide evidence of glia as a link in cooperative regulation of complex and rhythmic behavior that, in C. elegans links circuitry in the head and the tail.
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Affiliation(s)
- Stephanie N. Bowles
- Department of Biology, Georgia State University, Atlanta, GA, 30303, United States
| | - Casonya M. Johnson
- Department of Biology, Georgia State University, Atlanta, GA, 30303, United States
- Department of Biology, James Madison University, Harrisonburg, VA, 22807
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27
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Chiyoda H, Kume M, del Castillo CC, Kontani K, Spang A, Katada T, Fukuyama M. Caenorhabditis elegans PTR/PTCHD PTR-18 promotes the clearance of extracellular hedgehog-related protein via endocytosis. PLoS Genet 2021; 17:e1009457. [PMID: 33872306 PMCID: PMC8104386 DOI: 10.1371/journal.pgen.1009457] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 05/07/2021] [Accepted: 03/01/2021] [Indexed: 01/25/2023] Open
Abstract
Spatiotemporal restriction of signaling plays a critical role in animal development and tissue homeostasis. All stem and progenitor cells in newly hatched C. elegans larvae are quiescent and capable of suspending their development until sufficient food is supplied. Here, we show that ptr-18, which encodes the evolutionarily conserved patched-related (PTR)/patched domain-containing (PTCHD) protein, temporally restricts the availability of extracellular hedgehog-related protein to establish the capacity of progenitor cells to maintain quiescence. We found that neural progenitor cells exit from quiescence in ptr-18 mutant larvae even when hatched under starved conditions. This unwanted reactivation depended on the activity of a specific set of hedgehog-related grl genes including grl-7. Unexpectedly, neither PTR-18 nor GRL-7 were expressed in newly hatched wild-type larvae. Instead, at the late embryonic stage, both PTR-18 and GRL-7 proteins were first localized around the apical membrane of hypodermal and neural progenitor cells and subsequently targeted for lysosomal degradation before hatching. Loss of ptr-18 caused a significant delay in GRL-7 clearance, causing this protein to be retained in the extracellular space in newly hatched ptr-18 mutant larvae. Furthermore, the putative transporter activity of PTR-18 was shown to be required for the appropriate function of the protein. These findings not only uncover a previously undescribed role of PTR/PTCHD in the clearance of extracellular hedgehog-related proteins via endocytosis-mediated degradation but also illustrate that failure to temporally restrict intercellular signaling during embryogenesis can subsequently compromise post-embryonic progenitor cell function.
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Affiliation(s)
- Hirohisa Chiyoda
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Masahiko Kume
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | | | - Kenji Kontani
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Anne Spang
- Biozentrum, University of Basel, Basel, Switzerland
| | - Toshiaki Katada
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Masamitsu Fukuyama
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
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28
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Raiders S, Black EC, Bae A, MacFarlane S, Klein M, Shaham S, Singhvi A. Glia actively sculpt sensory neurons by controlled phagocytosis to tune animal behavior. eLife 2021; 10:63532. [PMID: 33759761 PMCID: PMC8079151 DOI: 10.7554/elife.63532] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 03/23/2021] [Indexed: 02/07/2023] Open
Abstract
Glia in the central nervous system engulf neuron fragments to remodel synapses and recycle photoreceptor outer segments. Whether glia passively clear shed neuronal debris or actively prune neuron fragments is unknown. How pruning of single-neuron endings impacts animal behavior is also unclear. Here, we report our discovery of glia-directed neuron pruning in Caenorhabditis elegans. Adult C. elegans AMsh glia engulf sensory endings of the AFD thermosensory neuron by repurposing components of the conserved apoptotic corpse phagocytosis machinery. The phosphatidylserine (PS) flippase TAT-1/ATP8A functions with glial PS-receptor PSR-1/PSR and PAT-2/α-integrin to initiate engulfment. This activates glial CED-10/Rac1 GTPase through the ternary GEF complex of CED-2/CrkII, CED-5/DOCK180, CED-12/ELMO. Execution of phagocytosis uses the actin-remodeler WSP-1/nWASp. This process dynamically tracks AFD activity and is regulated by temperature, the AFD sensory input. Importantly, glial CED-10 levels regulate engulfment rates downstream of neuron activity, and engulfment-defective mutants exhibit altered AFD-ending shape and thermosensory behavior. Our findings reveal a molecular pathway underlying glia-dependent engulfment in a peripheral sense-organ and demonstrate that glia actively engulf neuron fragments, with profound consequences on neuron shape and animal sensory behavior. Neurons are tree-shaped cells that receive information through endings connected to neighbouring cells or the environment. Controlling the size, number and location of these endings is necessary to ensure that circuits of neurons get precisely the right amount of input from their surroundings. Glial cells form a large portion of the nervous system, and they are tasked with supporting, cleaning and protecting neurons. In humans, part of their duties is to ‘eat’ (or prune) unnecessary neuron endings. In fact, this role is so important that defects in glial pruning are associated with conditions such as Alzheimer’s disease. Yet it is still unknown how pruning takes place, and in particular whether it is the neuron or the glial cell that initiates the process. To investigate this question, Raiders et al. enlisted the common laboratory animal Caenorhabditis elegans, a tiny worm with a simple nervous system where each neuron has been meticulously mapped out. First, the experiments showed that glial cells in C. elegans actually prune the endings of sensory neurons. Focusing on a single glia-neuron pair then revealed that the glial cell could trim the endings of a living neuron by redeploying the same molecular machinery it uses to clear dead cell debris. Compared to this debris-clearing activity, however, the glial cell takes a more nuanced approach to pruning: specifically, it can adjust the amount of trimming based on the activity load of the neuron. When Raiders et al. disrupted the glial pruning for a single temperature-sensing neuron, the worm lost its normal temperature preferences; this demonstrated how the pruning activity of a single glial cell can be linked to behavior. Taken together the experiments showcase how C. elegans can be used to study glial pruning. Further work using this model could help to understand how disease emerges when glial cells cannot perform their role, and to spot the genetic factors that put certain individuals at increased risk for neurological and sensory disorders.
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Affiliation(s)
- Stephan Raiders
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, United States.,Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, United States
| | - Erik Calvin Black
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, United States
| | - Andrea Bae
- Laboratory of Developmental Genetics, The Rockefeller University, New York, United States.,Cellular Imaging Shared Resources, Fred Hutchinson Cancer Research Center, Seattle, United States
| | - Stephen MacFarlane
- Department of Physics and Department of Biology, University of Miami, Coral Gables, United States
| | - Mason Klein
- Department of Physics and Department of Biology, University of Miami, Coral Gables, United States
| | - Shai Shaham
- Laboratory of Developmental Genetics, The Rockefeller University, New York, United States
| | - Aakanksha Singhvi
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, United States.,Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, United States.,Department of Biological Structure, University of Washington School of Medicine, Seattle, United States.,Brotman Baty Institute for Precision Medicine, Seattle, United States
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29
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Zhang A, Yan D. C. elegans as a model to study glial development. FEBS J 2021; 289:1476-1485. [PMID: 33570807 DOI: 10.1111/febs.15758] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 01/08/2021] [Accepted: 02/09/2021] [Indexed: 12/19/2022]
Abstract
Glia make up roughly half of all cells in the mammalian nervous system and play a major part in nervous system development, function, and disease. Although research in the past few decades has shed light on their morphological and functional diversity, there is still much to be known about key aspects of their development such as the generation of glial diversity and the factors governing proper morphogenesis. Glia of the nematode C. elegans possess many developmental and morphological similarities with their vertebrate counterparts and can potentially be used as a model to understand certain aspects of glial biology owing to advantages such as its genetic tractability and fully mapped cell lineage. In this review, we summarize recent progress in our understanding of genetic pathways that regulate glial development in C. elegans and discuss how some of these findings may be conserved.
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Affiliation(s)
- Albert Zhang
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA
| | - Dong Yan
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA.,Department of Neurobiology, Regeneration Next, and Duke Institute for Brain Sciences, Duke University Medical Center, Durham, NC, USA
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30
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Raiders S, Han T, Scott-Hewitt N, Kucenas S, Lew D, Logan MA, Singhvi A. Engulfed by Glia: Glial Pruning in Development, Function, and Injury across Species. J Neurosci 2021; 41:823-833. [PMID: 33468571 PMCID: PMC7880271 DOI: 10.1523/jneurosci.1660-20.2020] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 10/20/2020] [Accepted: 10/26/2020] [Indexed: 02/07/2023] Open
Abstract
Phagocytic activity of glial cells is essential for proper nervous system sculpting, maintenance of circuitry, and long-term brain health. Glial engulfment of apoptotic cells and superfluous connections ensures that neuronal connections are appropriately refined, while clearance of damaged projections and neurotoxic proteins in the mature brain protects against inflammatory insults. Comparative work across species and cell types in recent years highlights the striking conservation of pathways that govern glial engulfment. Many signaling cascades used during developmental pruning are re-employed in the mature brain to "fine tune" synaptic architecture and even clear neuronal debris following traumatic events. Moreover, the neuron-glia signaling events required to trigger and perform phagocytic responses are impressively conserved between invertebrates and vertebrates. This review offers a compare-and-contrast portrayal of recent findings that underscore the value of investigating glial engulfment mechanisms in a wide range of species and contexts.
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Affiliation(s)
- Stephan Raiders
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, Washington 98195
| | - Taeho Han
- UCSF Weill Institute for Neurosciences, University of California San Francisco, San Francisco, California 94158
| | - Nicole Scott-Hewitt
- F.M. Kirby Center for Neurobiology, Boston Children's Hospital, Boston, Massachusetts 02115
- Stanley Center for Psychiatric Research, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, Massachusetts 02142
| | - Sarah Kucenas
- Department of Biology, University of Virginia, Charlottesville, Virginia 22904
| | - Deborah Lew
- Department of Biological Sciences, Fordham University, Bronx, New York 10458
| | - Mary A Logan
- Jungers Center, Department of Neurology, Oregon Health and Science University, Portland, Oregon 97239
| | - Aakanksha Singhvi
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, Washington 98195
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31
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Park C, Sakurai Y, Sato H, Kanda S, Iino Y, Kunitomo H. Roles of the ClC chloride channel CLH-1 in food-associated salt chemotaxis behavior of C. elegans. eLife 2021; 10:e55701. [PMID: 33492228 PMCID: PMC7834019 DOI: 10.7554/elife.55701] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 01/04/2021] [Indexed: 01/19/2023] Open
Abstract
The ability of animals to process dynamic sensory information facilitates foraging in an ever-changing environment. However, molecular and neural mechanisms underlying such ability remain elusive. The ClC anion channels/transporters play a pivotal role in cellular ion homeostasis across all phyla. Here, we find a ClC chloride channel is involved in salt concentration chemotaxis of Caenorhabditis elegans. Genetic screening identified two altered-function mutations of clh-1 that disrupt experience-dependent salt chemotaxis. Using genetically encoded fluorescent sensors, we demonstrate that CLH-1 contributes to regulation of intracellular anion and calcium dynamics of salt-sensing neuron, ASER. The mutant CLH-1 reduced responsiveness of ASER to salt stimuli in terms of both temporal resolution and intensity, which disrupted navigation strategies for approaching preferred salt concentrations. Furthermore, other ClC genes appeared to act redundantly in salt chemotaxis. These findings provide insights into the regulatory mechanism of neuronal responsivity by ClCs that contribute to modulation of navigation behavior.
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Affiliation(s)
- Chanhyun Park
- Department of Biological Sciences, School of Science, The University of TokyoTokyoJapan
| | - Yuki Sakurai
- Department of Biological Sciences, School of Science, The University of TokyoTokyoJapan
| | - Hirofumi Sato
- Department of Biological Sciences, School of Science, The University of TokyoTokyoJapan
| | - Shinji Kanda
- Department of Biological Sciences, School of Science, The University of TokyoTokyoJapan
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, The University of TokyoChibaJapan
| | - Yuichi Iino
- Department of Biological Sciences, School of Science, The University of TokyoTokyoJapan
| | - Hirofumi Kunitomo
- Department of Biological Sciences, School of Science, The University of TokyoTokyoJapan
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32
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Nagai J, Yu X, Papouin T, Cheong E, Freeman MR, Monk KR, Hastings MH, Haydon PG, Rowitch D, Shaham S, Khakh BS. Behaviorally consequential astrocytic regulation of neural circuits. Neuron 2020; 109:576-596. [PMID: 33385325 DOI: 10.1016/j.neuron.2020.12.008] [Citation(s) in RCA: 123] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/23/2020] [Accepted: 12/07/2020] [Indexed: 12/16/2022]
Abstract
Astrocytes are a large and diverse population of morphologically complex cells that exist throughout nervous systems of multiple species. Progress over the last two decades has shown that astrocytes mediate developmental, physiological, and pathological processes. However, a long-standing open question is how astrocytes regulate neural circuits in ways that are behaviorally consequential. In this regard, we summarize recent studies using Caenorhabditis elegans, Drosophila melanogaster, Danio rerio, and Mus musculus. The data reveal diverse astrocyte mechanisms operating in seconds or much longer timescales within neural circuits and shaping multiple behavioral outputs. We also refer to human diseases that have a known primary astrocytic basis. We suggest that including astrocytes in mechanistic, theoretical, and computational studies of neural circuits provides new perspectives to understand behavior, its regulation, and its disease-related manifestations.
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Affiliation(s)
- Jun Nagai
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; RIKEN Center for Brain Science, 2-1 Hirosawa Wako City, Saitama 351-0198, Japan
| | - Xinzhu Yu
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, 514 Burrill Hall, 407 S. Goodwin Ave, Urbana, IL 61801, USA
| | - Thomas Papouin
- Department of Neuroscience, Washington University in St. Louis, School of Medicine, Campus Box 8108, 660 South Euclid Ave., St. Louis, MO 63110, USA
| | - Eunji Cheong
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, South Korea
| | - Marc R Freeman
- The Vollum Institute, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Kelly R Monk
- The Vollum Institute, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Michael H Hastings
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Philip G Haydon
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - David Rowitch
- Department of Paediatrics, Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK; Departments of Pediatrics and Neurosurgery, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA, USA
| | - Shai Shaham
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA.
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33
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Lago-Baldaia I, Fernandes VM, Ackerman SD. More Than Mortar: Glia as Architects of Nervous System Development and Disease. Front Cell Dev Biol 2020; 8:611269. [PMID: 33381506 PMCID: PMC7767919 DOI: 10.3389/fcell.2020.611269] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 11/17/2020] [Indexed: 12/12/2022] Open
Abstract
Glial cells are an essential component of the nervous system of vertebrates and invertebrates. In the human brain, glia are as numerous as neurons, yet the importance of glia to nearly every aspect of nervous system development has only been expounded over the last several decades. Glia are now known to regulate neural specification, synaptogenesis, synapse function, and even broad circuit function. Given their ubiquity, it is not surprising that the contribution of glia to neuronal disease pathogenesis is a growing area of research. In this review, we will summarize the accumulated evidence of glial participation in several distinct phases of nervous system development and organization-neural specification, circuit wiring, and circuit function. Finally, we will highlight how these early developmental roles of glia contribute to nervous system dysfunction in neurodevelopmental and neurodegenerative disorders.
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Affiliation(s)
- Inês Lago-Baldaia
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Vilaiwan M. Fernandes
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Sarah D. Ackerman
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, OR, United States
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34
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Molina-García L, Lloret-Fernández C, Cook SJ, Kim B, Bonnington RC, Sammut M, O'Shea JM, Gilbert SPR, Elliott DJ, Hall DH, Emmons SW, Barrios A, Poole RJ. Direct glia-to-neuron transdifferentiation gives rise to a pair of male-specific neurons that ensure nimble male mating. eLife 2020; 9:e48361. [PMID: 33138916 PMCID: PMC7609048 DOI: 10.7554/elife.48361] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 10/02/2020] [Indexed: 12/20/2022] Open
Abstract
Sexually dimorphic behaviours require underlying differences in the nervous system between males and females. The extent to which nervous systems are sexually dimorphic and the cellular and molecular mechanisms that regulate these differences are only beginning to be understood. We reveal here a novel mechanism by which male-specific neurons are generated in Caenorhabditis elegans through the direct transdifferentiation of sex-shared glial cells. This glia-to-neuron cell fate switch occurs during male sexual maturation under the cell-autonomous control of the sex-determination pathway. We show that the neurons generated are cholinergic, peptidergic, and ciliated putative proprioceptors which integrate into male-specific circuits for copulation. These neurons ensure coordinated backward movement along the mate's body during mating. One step of the mating sequence regulated by these neurons is an alternative readjustment movement performed when intromission becomes difficult to achieve. Our findings reveal programmed transdifferentiation as a developmental mechanism underlying flexibility in innate behaviour.
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Affiliation(s)
- Laura Molina-García
- Department of Cell and Developmental Biology, University College LondonLondonUnited Kingdom
| | - Carla Lloret-Fernández
- Department of Cell and Developmental Biology, University College LondonLondonUnited Kingdom
| | - Steven J Cook
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of MedicineNew YorkUnited States
| | - Byunghyuk Kim
- Department of Genetics, Albert Einstein College of MedicineNew YorkUnited States
| | - Rachel C Bonnington
- Department of Cell and Developmental Biology, University College LondonLondonUnited Kingdom
| | - Michele Sammut
- Department of Cell and Developmental Biology, University College LondonLondonUnited Kingdom
| | - Jack M O'Shea
- Department of Cell and Developmental Biology, University College LondonLondonUnited Kingdom
| | - Sophie PR Gilbert
- Department of Cell and Developmental Biology, University College LondonLondonUnited Kingdom
| | - David J Elliott
- Department of Cell and Developmental Biology, University College LondonLondonUnited Kingdom
| | - David H Hall
- Department of Genetics, Albert Einstein College of MedicineNew YorkUnited States
| | - Scott W Emmons
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of MedicineNew YorkUnited States
- Department of Genetics, Albert Einstein College of MedicineNew YorkUnited States
| | - Arantza Barrios
- Department of Cell and Developmental Biology, University College LondonLondonUnited Kingdom
| | - Richard J Poole
- Department of Cell and Developmental Biology, University College LondonLondonUnited Kingdom
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35
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Duan D, Zhang H, Yue X, Fan Y, Xue Y, Shao J, Ding G, Chen D, Li S, Cheng H, Zhang X, Zou W, Liu J, Zhao J, Wang L, Zhao B, Wang Z, Xu S, Wen Q, Liu J, Duan S, Kang L. Sensory Glia Detect Repulsive Odorants and Drive Olfactory Adaptation. Neuron 2020; 108:707-721.e8. [PMID: 32970991 DOI: 10.1016/j.neuron.2020.08.026] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 07/25/2020] [Accepted: 08/26/2020] [Indexed: 12/18/2022]
Abstract
Glia are typically considered as supporting cells for neural development and synaptic transmission. Here, we report an active role of a glia in olfactory transduction. As a polymodal sensory neuron in C. elegans, the ASH neuron is previously known to detect multiple aversive odorants. We reveal that the AMsh glia, a sheath for multiple sensory neurons including ASH, cell-autonomously respond to aversive odorants via G-protein-coupled receptors (GPCRs) distinct from those in ASH. Upon activation, the AMsh glia suppress aversive odorant-triggered avoidance and promote olfactory adaptation by inhibiting the ASH neuron via GABA signaling. Thus, we propose a novel two-receptor model where the glia and sensory neuron jointly mediate adaptive olfaction. Our study reveals a non-canonical function of glial cells in olfactory transduction, which may provide new insights into the glia-like supporting cells in mammalian sensory procession.
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Affiliation(s)
- Duo Duan
- Department of Neurobiology and Department of Neurosurgery of the First Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang 310053, China; NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang 310053, China; Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang 310053, China
| | - Hu Zhang
- Department of Neurobiology and Department of Neurosurgery of the First Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang 310053, China; NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang 310053, China
| | - Xiaomin Yue
- Department of Neurobiology and Department of Neurosurgery of the First Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang 310053, China; NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang 310053, China
| | - Yuedan Fan
- Department of Neurobiology and Department of Neurosurgery of the First Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang 310053, China; NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang 310053, China
| | - Yadan Xue
- Department of Neurobiology and Department of Neurosurgery of the First Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang 310053, China
| | - Jiajie Shao
- Department of Neurobiology and Department of Neurosurgery of the First Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang 310053, China
| | - Gang Ding
- Department of Neurobiology and Department of Neurosurgery of the First Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang 310053, China
| | - Du Chen
- Department of Neurobiology and Department of Neurosurgery of the First Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang 310053, China
| | - Shitian Li
- Department of Neurobiology and Department of Neurosurgery of the First Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang 310053, China
| | - Hankui Cheng
- Department of Neurobiology and Department of Neurosurgery of the First Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang 310053, China
| | - Xiaoyan Zhang
- Department of Neurobiology and Department of Neurosurgery of the First Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang 310053, China
| | - Wenjuan Zou
- Department of Neurobiology and Department of Neurosurgery of the First Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang 310053, China
| | - Jia Liu
- Department of Neurobiology and Department of Neurosurgery of the First Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang 310053, China
| | - Jian Zhao
- Department of Neurobiology and Department of Neurosurgery of the First Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang 310053, China
| | - Linmei Wang
- Department of Neurobiology and Department of Neurosurgery of the First Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang 310053, China
| | - Bingzhen Zhao
- Chinese Academy of Sciences Key Laboratory of Brain Function and Disease, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Zhiping Wang
- Department of Neurobiology and Department of Neurosurgery of the First Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang 310053, China
| | - Suhong Xu
- Center for Stem Cell and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Quan Wen
- Chinese Academy of Sciences Key Laboratory of Brain Function and Disease, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Jie Liu
- Monash Biomedicine Discovery Institute, Department of Anatomy and Developmental Biology, Monash University, Clayton, VIC 3800, Australia
| | - Shumin Duan
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang 310053, China; Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang 310053, China.
| | - Lijun Kang
- Department of Neurobiology and Department of Neurosurgery of the First Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang 310053, China; NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang 310053, China.
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Fung W, Wexler L, Heiman MG. Cell-type-specific promoters for C. elegans glia. J Neurogenet 2020; 34:335-346. [PMID: 32696701 PMCID: PMC7855602 DOI: 10.1080/01677063.2020.1781851] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 06/08/2020] [Indexed: 12/26/2022]
Abstract
Glia shape the development and function of the C. elegans nervous system, especially its sense organs and central neuropil (nerve ring). Cell-type-specific promoters allow investigators to label or manipulate individual glial cell types, and therefore provide a key tool for deciphering glial function. In this technical resource, we compare the specificity, brightness, and consistency of cell-type-specific promoters for C. elegans glia. We identify a set of promoters for the study of seven glial cell types (F16F9.3, amphid and phasmid sheath glia; F11C7.2, amphid sheath glia only; grl-2, amphid and phasmid socket glia; hlh-17, cephalic (CEP) sheath glia; and grl-18, inner labial (IL) socket glia) as well as a pan-glial promoter (mir-228). We compare these promoters to promoters that are expressed more variably in combinations of glial cell types (delm-1 and itx-1). We note that the expression of some promoters depends on external conditions or the internal state of the organism, such as developmental stage, suggesting glial plasticity. Finally, we demonstrate an approach for prospectively identifying cell-type-specific glial promoters using existing single-cell sequencing data, and we use this approach to identify two novel promoters specific to IL socket glia (col-53 and col-177).
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Affiliation(s)
- Wendy Fung
- These authors contributed equally to this work
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Boston Children’s Hospital, Boston MA 02115
| | - Leigh Wexler
- These authors contributed equally to this work
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Boston Children’s Hospital, Boston MA 02115
| | - Maxwell G. Heiman
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Boston Children’s Hospital, Boston MA 02115
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37
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Frakes AE, Metcalf MG, Tronnes SU, Bar-Ziv R, Durieux J, Gildea HK, Kandahari N, Monshietehadi S, Dillin A. Four glial cells regulate ER stress resistance and longevity via neuropeptide signaling in C. elegans. Science 2020; 367:436-440. [PMID: 31974253 DOI: 10.1126/science.aaz6896] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 11/29/2019] [Indexed: 12/21/2022]
Abstract
The ability of the nervous system to sense cellular stress and coordinate protein homeostasis is essential for organismal health. Unfortunately, stress responses that mitigate disturbances in proteostasis, such as the unfolded protein response of the endoplasmic reticulum (UPRER), become defunct with age. In this work, we expressed the constitutively active UPRER transcription factor, XBP-1s, in a subset of astrocyte-like glia, which extended the life span in Caenorhabditis elegans Glial XBP-1s initiated a robust cell nonautonomous activation of the UPRER in distal cells and rendered animals more resistant to protein aggregation and chronic ER stress. Mutants deficient in neuropeptide processing and secretion suppressed glial cell nonautonomous induction of the UPRER and life-span extension. Thus, astrocyte-like glial cells play a role in regulating organismal ER stress resistance and longevity.
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Affiliation(s)
- Ashley E Frakes
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.,Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA
| | - Melissa G Metcalf
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.,Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA
| | - Sarah U Tronnes
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.,Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA
| | - Raz Bar-Ziv
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.,Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA
| | - Jenni Durieux
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.,Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA
| | - Holly K Gildea
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.,Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA
| | - Nazineen Kandahari
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.,Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA
| | - Samira Monshietehadi
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.,Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA
| | - Andrew Dillin
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA. .,Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA
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38
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Gonsior M, Ismat A. sli is required for proper morphology and migration of sensory neurons in the Drosophila PNS. Neural Dev 2019; 14:10. [PMID: 31651354 PMCID: PMC6813078 DOI: 10.1186/s13064-019-0135-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 10/17/2019] [Indexed: 11/12/2022] Open
Abstract
Neurons and glial cells coordinate with each other in many different aspects of nervous system development. Both types of cells are receiving multiple guidance cues to guide the neurons and glial cells to their proper final position. The lateral chordotonal organs (lch5) of the Drosophila peripheral nervous system (PNS) are composed of five sensory neurons surrounded by four different glial cells, scolopale cells, cap cells, attachment cells and ligament cells. During embryogenesis, the lch5 neurons go through a rotation and ventral migration to reach their final position in the lateral region of the abdomen. We show here that the extracellular ligand sli is required for the proper ventral migration and morphology of the lch5 neurons. We further show that mutations in the Sli receptors Robo and Robo2 also display similar defects as loss of sli, suggesting a role for Slit-Robo signaling in lch5 migration and positioning. Additionally, we demonstrate that the scolopale, cap and attachment cells follow the mis-migrated lch5 neurons in sli mutants, while the ventral stretching of the ligament cells seems to be independent of the lch5 neurons. This study sheds light on the role of Slit-Robo signaling in sensory neuron development.
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Affiliation(s)
- Madison Gonsior
- Department of Biology, University of St. Thomas, Saint Paul, MN, 55104, USA
| | - Afshan Ismat
- Department of Biology, University of St. Thomas, Saint Paul, MN, 55104, USA.
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Abstract
Glia are abundant components of animal nervous systems. Recognized 170 years ago, concerted attempts to understand these cells began only recently. From these investigations glia, once considered passive filler material in the brain, have emerged as active players in neuron development and activity. Glia are essential for nervous system function, and their disruption leads to disease. The nematode Caenorhabditis elegans possesses glial types similar to vertebrate glia, based on molecular, morphological, and functional criteria, and has become a powerful model in which to study glia and their neuronal interactions. Facile genetic and transgenic methods in this animal allow the discovery of genes required for glial functions, and effects of glia at single synapses can be monitored by tracking neuron shape, physiology, or animal behavior. Here, we review recent progress in understanding glia-neuron interactions in C. elegans. We highlight similarities with glia in other animals, and suggest conserved emerging principles of glial function.
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Affiliation(s)
- Aakanksha Singhvi
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA;
| | - Shai Shaham
- Laboratory of Developmental Genetics, The Rockefeller University, New York, NY 10065, USA;
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40
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Poberezhnyi VI, Marchuk OV, Shvidyuk OS, Petrik IY, Logvinov OS. Fundamentals of the modern theory of the phenomenon of "pain" from the perspective of a systematic approach. Neurophysiological basis. Part 1: A brief presentation of key subcellular and cellular ctructural elements of the central nervous system. PAIN MEDICINE 2019. [DOI: 10.31636/pmjua.v3i4.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The phenomenon of “pain” is a psychophysiological phenomenon that is actualized in the mind of a person as a result of the systemic response of his body to certain external and internal stimuli. The heart of the corresponding mental processes is certain neurophysiological processes, which in turn are caused by a certain form of the systemic structural and functional organization of the central nervous system (CNS). Thus, the systemic structural and functional organization of the central nervous system of a person, determining the corresponding psychophysiological state in a specific time interval, determines its psycho-emotional states or reactions manifested by the pain phenomenon. The nervous system of the human body has a hierarchical structure and is a morphologically and functionally complete set of different, interconnected, nervous and structural formations. The basis of the structural formations of the nervous system is nervous tissue. It is a system of interconnected differentials of nerve cells, neuroglia and glial macrophages, providing specific functions of perception of stimulation, excitation, generation of nerve impulses and its transmission. The neuron and each of its compartments (spines, dendrites, catfish, axon) is an autonomous, plastic, active, structural formation with complex computational properties. One of them – dendrites – plays a key role in the integration and processing of information. Dendrites, due to their morphology, provide neurons with unique electrical and plastic properties and cause variations in their computational properties. The morphology of dendrites: 1) determines – a) the number and type of contacts that a particular neuron can form with other neurons; b) the complexity, diversity of its functions; c) its computational operations; 2) determines – a) variations in the computational properties of a neuron (variations of the discharges between bursts and regular forms of pulsation); b) back distribution of action potentials. Dendritic spines can form synaptic connection – one of the main factors for increasing the diversity of forms of synaptic connections of neurons. Their volume and shape can change over a short period of time, and they can rotate in space, appear and disappear by themselves. Spines play a key role in selectively changing the strength of synaptic connections during the memorization and learning process. Glial cells are active participants in diffuse transmission of nerve impulses in the brain. Astrocytes form a three-dimensional, functionally “syncytia-like” formation, inside of which there are neurons, thus causing their specific microenvironment. They and neurons are structurally and functionally interconnected, based on which their permanent interaction occurs. Oligodendrocytes provide conditions for the generation and transmission of nerve impulses along the processes of neurons and play a significant role in the processes of their excitation and inhibition. Microglial cells play an important role in the formation of the brain, especially in the formation and maintenance of synapses. Thus, the CNS should be considered as a single, functionally “syncytia-like”, structural entity. Because the three-dimensional distribution of dendritic branches in space is important for determining the type of information that goes to a neuron, it is necessary to consider the three-dimensionality of their structure when analyzing the implementation of their functions.
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41
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Low IIC, Williams CR, Chong MK, McLachlan IG, Wierbowski BM, Kolotuev I, Heiman MG. Morphogenesis of neurons and glia within an epithelium. Development 2019; 146:dev171124. [PMID: 30683663 PMCID: PMC6398450 DOI: 10.1242/dev.171124] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Accepted: 01/15/2019] [Indexed: 12/13/2022]
Abstract
To sense the outside world, some neurons protrude across epithelia, the cellular barriers that line every surface of our bodies. To study the morphogenesis of such neurons, we examined the C. elegans amphid, in which dendrites protrude through a glial channel at the nose. During development, amphid dendrites extend by attaching to the nose via DYF-7, a type of protein typically found in epithelial apical ECM. Here, we show that amphid neurons and glia exhibit epithelial properties, including tight junctions and apical-basal polarity, and develop in a manner resembling other epithelia. We find that DYF-7 is a fibril-forming apical ECM component that promotes formation of the tube-shaped glial channel, reminiscent of roles for apical ECM in other narrow epithelial tubes. We also identify a requirement for FRM-2, a homolog of EPBL15/moe/Yurt that promotes epithelial integrity in other systems. Finally, we show that other environmentally exposed neurons share a requirement for DYF-7. Together, our results suggest that these neurons and glia can be viewed as part of an epithelium continuous with the skin, and are shaped by mechanisms shared with other epithelia.
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Affiliation(s)
- Isabel I C Low
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Boston Children's Hospital, Boston, MA 02115, USA
| | - Claire R Williams
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Boston Children's Hospital, Boston, MA 02115, USA
| | - Megan K Chong
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Boston Children's Hospital, Boston, MA 02115, USA
| | - Ian G McLachlan
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Boston Children's Hospital, Boston, MA 02115, USA
| | - Bradley M Wierbowski
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Boston Children's Hospital, Boston, MA 02115, USA
| | - Irina Kolotuev
- Université de Rennes 1, Plateforme microscopie électronique, 35043 Rennes, France
| | - Maxwell G Heiman
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Boston Children's Hospital, Boston, MA 02115, USA
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42
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Yin JA, Gao G, Liu XJ, Hao ZQ, Li K, Kang XL, Li H, Shan YH, Hu WL, Li HP, Cai SQ. Genetic variation in glia-neuron signalling modulates ageing rate. Nature 2017; 551:198-203. [PMID: 29120414 DOI: 10.1038/nature24463] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 10/02/2017] [Indexed: 12/25/2022]
Abstract
The rate of behavioural decline in the ageing population is remarkably variable among individuals. Despite the considerable interest in studying natural variation in ageing rate to identify factors that control healthy ageing, no such factor has yet been found. Here we report a genetic basis for variation in ageing rates in Caenorhabditis elegans. We find that C. elegans isolates show diverse lifespan and age-related declines in virility, pharyngeal pumping, and locomotion. DNA polymorphisms in a novel peptide-coding gene, named regulatory-gene-for-behavioural-ageing-1 (rgba-1), and the neuropeptide receptor gene npr-28 influence the rate of age-related decline of worm mating behaviour; these two genes might have been subjected to recent selective sweeps. Glia-derived RGBA-1 activates NPR-28 signalling, which acts in serotonergic and dopaminergic neurons to accelerate behavioural deterioration. This signalling involves the SIR-2.1-dependent activation of the mitochondrial unfolded protein response, a pathway that modulates ageing. Thus, natural variation in neuropeptide-mediated glia-neuron signalling modulates the rate of ageing in C. elegans.
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Affiliation(s)
- Jiang-An Yin
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Ge Gao
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xi-Juan Liu
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Zi-Qian Hao
- University of Chinese Academy of Sciences, Beijing, 100049, China
- CAS Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Kai Li
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Xin-Lei Kang
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Hong Li
- Core Facility of Molecular Biology, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Yuan-Hong Shan
- Core Facility Center of the Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Wen-Li Hu
- Core Facility Center of the Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Hai-Peng Li
- CAS Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Shi-Qing Cai
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
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43
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Go and stop signals for glial regeneration. Curr Opin Neurobiol 2017; 47:182-187. [PMID: 29126016 PMCID: PMC6419527 DOI: 10.1016/j.conb.2017.10.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 08/16/2017] [Accepted: 10/10/2017] [Indexed: 12/22/2022]
Abstract
The regenerative response of ensheating glia to central nervous system (CNS) injury involves proliferation and differentiation, axonal re-enwrapment and some recovery of behaviour. Understanding this limited response could enable the enhancement of it. In Drosophila, the glial progenitor state is maintained by Notch, an activator of cell division and Prospero (Pros), a repressor. Injury provokes the activation of NFκB and up-regulation of Kon-tiki (Kon), driving cell proliferation. Homeostatic switch-off comes about as two negative feedback loops involving Pros terminate the response. Importantly, the functions of the kon and pros homologues NG2 and prox1, respectively, are conserved in mammalian NG2 glia. Controlling these genes is key for therapeutic manipulation of progenitors and stem cells to promote regeneration of the damaged CNS.
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44
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Lamkin ER, Heiman MG. Coordinated morphogenesis of neurons and glia. Curr Opin Neurobiol 2017; 47:58-64. [PMID: 28988011 DOI: 10.1016/j.conb.2017.09.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 09/17/2017] [Indexed: 11/19/2022]
Abstract
Glia adopt remarkable shapes that are tightly coordinated with the morphologies of their neuronal partners. To achieve these precise shapes, glia and neurons exhibit coordinated morphological changes on the time scale of minutes and on size scales ranging from nanometers to hundreds of microns. Here, we review recent studies that reveal the highly dynamic, localized morphological changes of mammalian neuron-glia contacts. We then explore the power of Drosophila and C. elegans models to study coordinated changes at defined neuron-glia contacts, highlighting the use of innovative genetic and imaging tools to uncover the molecular mechanisms responsible for coordinated morphogenesis of neurons and glia.
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Affiliation(s)
- Elizabeth R Lamkin
- Department of Genetics, Harvard Medical School and Division of Genetics and Genomics, Boston Children's Hospital, Boston MA 02115, United States
| | - Maxwell G Heiman
- Department of Genetics, Harvard Medical School and Division of Genetics and Genomics, Boston Children's Hospital, Boston MA 02115, United States.
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45
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IGDB-2, an Ig/FNIII protein, binds the ion channel LGC-34 and controls sensory compartment morphogenesis in C. elegans. Dev Biol 2017; 430:105-112. [PMID: 28803967 DOI: 10.1016/j.ydbio.2017.08.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 08/04/2017] [Accepted: 08/07/2017] [Indexed: 11/21/2022]
Abstract
Sensory organ glia surround neuronal receptive endings (NREs), forming a specialized compartment important for neuronal activity, and reminiscent of glia-ensheathed synapses in the central nervous system. We previously showed that DAF-6, a Patched-related protein, is required in glia of the C. elegans amphid sensory organ to restrict sensory compartment size. LIT-1, a Nemo-like kinase, and SNX-1, a retromer component, antagonize DAF-6 and promote compartment expansion. To further explore the machinery underlying compartment size control, we sought genes whose inactivation restores normal compartment size to daf-6 mutants. We found that mutations in igdb-2, encoding a single-pass transmembrane protein containing Ig-like and fibronectin type III domains, suppress daf-6 mutant defects. IGDB-2 acts in glia, where it localizes to glial membranes surrounding NREs, and, together with LIT-1 and SNX-1, regulates compartment morphogenesis. Immunoprecipitation followed by mass spectrometry demonstrates that IGDB-2 binds to LGC-34, a predicted ligand-gated ion channel, and lgc-34 mutations inhibit igdb-2 suppression of daf-6. Our findings reveal a novel membrane protein complex and suggest possible mechanisms for how sensory compartment size is controlled.
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46
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Wallace SW, Shaham S. Sensory Cilia: Generating Diverse Shapes One Ig Domain at a Time. Curr Biol 2017; 27:R654-R656. [PMID: 28697365 DOI: 10.1016/j.cub.2017.05.051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
How morphologically complex cilia form is not well understood. A key regulator of ciliary shape has now been identified that links the establishment of neuronal fate with the formation of cell-specific ciliary structures in Caenorhabditis elegans.
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Affiliation(s)
- Sean W Wallace
- The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA
| | - Shai Shaham
- The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA.
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47
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Charlton-Perkins MA, Sendler ED, Buschbeck EK, Cook TA. Multifunctional glial support by Semper cells in the Drosophila retina. PLoS Genet 2017; 13:e1006782. [PMID: 28562601 PMCID: PMC5470715 DOI: 10.1371/journal.pgen.1006782] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Revised: 06/14/2017] [Accepted: 04/26/2017] [Indexed: 11/19/2022] Open
Abstract
Glial cells play structural and functional roles central to the formation, activity and integrity of neurons throughout the nervous system. In the retina of vertebrates, the high energetic demand of photoreceptors is sustained in part by Müller glia, an intrinsic, atypical radial glia with features common to many glial subtypes. Accessory and support glial cells also exist in invertebrates, but which cells play this function in the insect retina is largely undefined. Using cell-restricted transcriptome analysis, here we show that the ommatidial cone cells (aka Semper cells) in the Drosophila compound eye are enriched for glial regulators and effectors, including signature characteristics of the vertebrate visual system. In addition, cone cell-targeted gene knockdowns demonstrate that such glia-associated factors are required to support the structural and functional integrity of neighboring photoreceptors. Specifically, we show that distinct support functions (neuronal activity, structural integrity and sustained neurotransmission) can be genetically separated in cone cells by down-regulating transcription factors associated with vertebrate gliogenesis (pros/Prox1, Pax2/5/8, and Oli/Olig1,2, respectively). Further, we find that specific factors critical for glial function in other species are also critical in cone cells to support Drosophila photoreceptor activity. These include ion-transport proteins (Na/K+-ATPase, Eaat1, and Kir4.1-related channels) and metabolic homeostatic factors (dLDH and Glut1). These data define genetically distinct glial signatures in cone/Semper cells that regulate their structural, functional and homeostatic interactions with photoreceptor neurons in the compound eye of Drosophila. In addition to providing a new high-throughput model to study neuron-glia interactions, the fly eye will further help elucidate glial conserved "support networks" between invertebrates and vertebrates. Glia are the caretakers of the nervous system. Like their neighboring neurons, different glial subtypes exist that share many overlapping functions. Despite our recognition of glia as a key component of the brain, the genetic networks that mediate their neuroprotective functions remain relatively poorly understood. Here, using the genetic model Drosophila melanogaster, we identify a new glial cell type in one of the most active tissues in the nervous system—the retina. These cells, called ommatidial cone cells (or Semper cells), were previously recognized for their role in lens formation. Using cell-specific molecular genetic approaches, we demonstrate that cone cells (CCs) also share molecular, functional, and genetic features with both vertebrate and invertebrate glia to prevent light-induced retinal degeneration and provide structural and physiological support for photoreceptors. Further, we demonstrate that three factors associated with gliogenesis in vertebrates—prospero/Prox1, Pax2, and Oli/Olig1,2—control genetically distinct aspects of these support functions. CCs also share molecular and functional features with the three main glial types in the mammalian visual system: Müller glia, astrocytes, and oligodendrocytes. Combined, these studies provide insight into potentially deeply conserved aspects of glial functions in the visual system and introduce a high-throughput system to genetically dissect essential neuroprotective mechanisms.
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Affiliation(s)
- Mark A. Charlton-Perkins
- Department of Pediatrics, Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Edward D. Sendler
- Center of Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, Michigan, United States of America
| | - Elke K. Buschbeck
- Department of Biological Sciences, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Tiffany A. Cook
- Center of Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, Michigan, United States of America
- Department of Ophthalmology, Wayne State University School of Medicine, Detroit, Michigan, United States of America
- * E-mail:
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48
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Kage-Nakadai E, Ohta A, Ujisawa T, Sun S, Nishikawa Y, Kuhara A, Mitani S. Caenorhabditis elegans homologue of Prox1/Prospero is expressed in the glia and is required for sensory behavior and cold tolerance. Genes Cells 2016; 21:936-48. [PMID: 27402188 DOI: 10.1111/gtc.12394] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 06/11/2016] [Indexed: 02/01/2023]
Abstract
The Caenorhabditis elegans (C. elegans) amphid sensory organ contains only 4 glia-like cells and 24 sensory neurons, providing a simple model for analyzing glia or neuron-glia interactions. To better characterize glial development and function, we carried out RNA interference screening for transcription factors that regulate the expression of an amphid sheath glial cell marker and identified pros-1, which encodes a homeodomain transcription factor homologous to Drosophila prospero/mammalian Prox1, as a positive regulator. The functional PROS-1::EGFP fusion protein was localized in the nuclei of the glia and the excretory cell but not in the amphid sensory neurons. pros-1 deletion mutants exhibited larval lethality, and rescue experiments showed that pros-1 and human Prox1 transgenes were able to rescue the larval lethal phenotype, suggesting that pros-1 is a functional homologue of mammalian Prox1, at least partially. We further found that the structure and functions of sensory neurons, such as the morphology of sensory endings, sensory behavior and sensory-mediated cold tolerance, appeared to be affected by the pros-1 RNAi. Together, our results show that the C. elegans PROS-1 is a transcriptional regulator in the glia but is involved not only in sensory behavior but also in sensory-mediated physiological tolerance.
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Affiliation(s)
- Eriko Kage-Nakadai
- Department of Physiology, Tokyo Women's Medical University School of Medicine, Tokyo, 162-8666, Japan.,The OCU Advanced Research Institute for Natural Science and Technology, Osaka City University, Osaka, 558-8585, Japan.,Graduate School of Human Life Science, Osaka City University, Osaka, 558-8585, Japan
| | - Akane Ohta
- Laboratory of Molecular and Cellular Regulation, Faculty of Science and Engineering, and Institute for Integrative Neurobiology, Konan University, Kobe, 658-8501, Japan
| | - Tomoyo Ujisawa
- Laboratory of Molecular and Cellular Regulation, Faculty of Science and Engineering, and Institute for Integrative Neurobiology, Konan University, Kobe, 658-8501, Japan
| | - Simo Sun
- Graduate School of Human Life Science, Osaka City University, Osaka, 558-8585, Japan
| | - Yoshikazu Nishikawa
- Graduate School of Human Life Science, Osaka City University, Osaka, 558-8585, Japan
| | - Atsushi Kuhara
- Laboratory of Molecular and Cellular Regulation, Faculty of Science and Engineering, and Institute for Integrative Neurobiology, Konan University, Kobe, 658-8501, Japan
| | - Shohei Mitani
- Department of Physiology, Tokyo Women's Medical University School of Medicine, Tokyo, 162-8666, Japan.
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