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Dong J, Zhu XN, Zeng PM, Cao DD, Yang Y, Hu J, Luo ZG. A hominoid-specific signaling axis regulating the tempo of synaptic maturation. Cell Rep 2024; 43:114548. [PMID: 39052482 DOI: 10.1016/j.celrep.2024.114548] [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: 11/13/2023] [Revised: 04/15/2024] [Accepted: 07/12/2024] [Indexed: 07/27/2024] Open
Abstract
Human cortical neurons (hCNs) exhibit high dendritic complexity and synaptic density, and the maturation process is greatly protracted. However, the molecular mechanism governing these specific features remains unclear. Here, we report that the hominoid-specific gene TBC1D3 promotes dendritic arborization and protracts the pace of synaptogenesis. Ablation of TBC1D3 in induced hCNs causes reduction of dendritic growth and precocious synaptic maturation. Forced expression of TBC1D3 in the mouse cortex protracts synaptic maturation while increasing dendritic growth. Mechanistically, TBC1D3 functions via interaction with MICAL1, a monooxygenase that mediates oxidation of actin filament. At the early stage of differentiation, the TBC1D3/MICAL1 interaction in the cytosol promotes dendritic growth via F-actin oxidation and enhanced actin dynamics. At late stages, TBC1D3 escorts MICAL1 into the nucleus and downregulates the expression of genes related with synaptic maturation through interaction with the chromatin remodeling factor ATRX. Thus, this study delineates the molecular mechanisms underlying human neuron development.
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Affiliation(s)
- Jian Dong
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; State Key Laboratory of Advanced Medical Materials and Devices, ShanghaiTech University, Shanghai 201210, China
| | - Xiao-Na Zhu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Peng-Ming Zeng
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; State Key Laboratory of Advanced Medical Materials and Devices, ShanghaiTech University, Shanghai 201210, China
| | - Dong-Dong Cao
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; State Key Laboratory of Advanced Medical Materials and Devices, ShanghaiTech University, Shanghai 201210, China
| | - Yang Yang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; State Key Laboratory of Advanced Medical Materials and Devices, ShanghaiTech University, Shanghai 201210, China
| | - Ji Hu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Zhen-Ge Luo
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; State Key Laboratory of Advanced Medical Materials and Devices, ShanghaiTech University, Shanghai 201210, China.
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2
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Wen P, Li J, Wen Z, Guo X, Ma G, Hu S, Xu J, Zhao H, Li R, Liu Y, Wang Y, Gao J. MICAL-L2, as an estrogen-responsive gene, is involved in ER-positive breast cancer cell progression and tamoxifen sensitivity via the AKT/mTOR pathway. Biochem Pharmacol 2024; 225:116256. [PMID: 38729448 DOI: 10.1016/j.bcp.2024.116256] [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: 11/15/2023] [Revised: 03/25/2024] [Accepted: 05/02/2024] [Indexed: 05/12/2024]
Abstract
Endocrine treatment, particularly tamoxifen, has shown significant improvement in the prognosis of patients with estrogen receptor-positive (ER-positive) breast cancer. However, the clinical utility of this treatment is often hindered by the development of endocrine resistance. Therefore, a comprehensive understanding of the underlying mechanisms driving ER-positive breast cancer carcinogenesis and endocrine resistance is crucial to overcome this clinical challenge. In this study, we investigated the expression of MICAL-L2 in ER-positive breast cancer and its impact on patient prognosis. We observed a significant upregulation of MICAL-L2 expression in ER-positive breast cancer, which correlated with a poorer prognosis in these patients. Furthermore, we found that estrogen-ERβ signaling promoted the expression of MICAL-L2. Functionally, our study demonstrated that MICAL-L2 not only played an oncogenic role in ER-positive breast cancer tumorigenesis but also influenced the sensitivity of ER-positive breast cancer cells to tamoxifen. Mechanistically, as an estrogen-responsive gene, MICAL-L2 facilitated the activation of the AKT/mTOR signaling pathway in ER-positive breast cancer cells. Collectively, our findings suggest that MICAL-L2 could serve as a potential prognostic marker for ER-positive breast cancer and represent a promising molecular target for improving endocrine treatment and developing therapeutic approaches for this subtype of breast cancer.
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Affiliation(s)
- Pushuai Wen
- Department of Pathophysiology, Jinzhou Medical University, Jinzhou 121001, China; Biological Anthropology Institute, Jinzhou Medical University, Jinzhou 121001, China.
| | - Jing Li
- Liaoning Technology and Engineering Center for Tumor Immunology and Molecular Theranotics, Collaborative Innovation Center for Age-related Disease, Life Science Institute of Jinzhou Medical University, Jinzhou 121001, China
| | - Zihao Wen
- Department of Pathophysiology, Jinzhou Medical University, Jinzhou 121001, China
| | - Xiaoyan Guo
- Liaoning Technology and Engineering Center for Tumor Immunology and Molecular Theranotics, Collaborative Innovation Center for Age-related Disease, Life Science Institute of Jinzhou Medical University, Jinzhou 121001, China
| | - Guoqun Ma
- Department of Pathophysiology, Jinzhou Medical University, Jinzhou 121001, China
| | - Shuzhen Hu
- Department of Pathophysiology, Jinzhou Medical University, Jinzhou 121001, China
| | - Jiamei Xu
- Department of Pathophysiology, Jinzhou Medical University, Jinzhou 121001, China
| | - Hongli Zhao
- Department of Pathophysiology, Jinzhou Medical University, Jinzhou 121001, China
| | - Ruixin Li
- Department of Pathophysiology, Jinzhou Medical University, Jinzhou 121001, China
| | - Ying Liu
- Liaoning Technology and Engineering Center for Tumor Immunology and Molecular Theranotics, Collaborative Innovation Center for Age-related Disease, Life Science Institute of Jinzhou Medical University, Jinzhou 121001, China.
| | - Yu Wang
- Liaoning Technology and Engineering Center for Tumor Immunology and Molecular Theranotics, Collaborative Innovation Center for Age-related Disease, Life Science Institute of Jinzhou Medical University, Jinzhou 121001, China.
| | - Jing Gao
- Department of Ultrasonography, The First Affiliated Hospital, Jinzhou Medical University, Jinzhou 121001, China.
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Rui M. Recent progress in dendritic pruning of Drosophila C4da sensory neurons. Open Biol 2024; 14:240059. [PMID: 39046196 PMCID: PMC11267989 DOI: 10.1098/rsob.240059] [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: 03/08/2024] [Revised: 05/27/2024] [Accepted: 05/28/2024] [Indexed: 07/25/2024] Open
Abstract
The brain can adapt to changes in the environment through alterations in the number and structure of synapses. During embryonic and early postnatal stages, the synapses in the brain undergo rapid expansion and interconnections to form circuits. However, many of these synaptic connections are redundant or incorrect. Neurite pruning is a conserved process that occurs during both vertebrate and invertebrate development. It requires precise spatiotemporal control of local degradation of cellular components, comprising cytoskeletons and membranes, refines neuronal circuits, and ensures the precise connectivity required for proper function. The Drosophila's class IV dendritic arborization (C4da) sensory neuron has a well-characterized architecture and undergoes dendrite-specific sculpting, making it a valuable model for unravelling the intricate regulatory mechanisms underlie dendritic pruning. In this review, I attempt to provide an overview of the present state of research on dendritic pruning in C4da sensory neurons, as well as potential functional mechanisms in neurodevelopmental disorders.
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Affiliation(s)
- Menglong Rui
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing210096, People‘s Republic of China
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4
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Wang W, Rui M. Advances in understanding the roles of actin scaffolding and membrane trafficking in dendrite development. J Genet Genomics 2024:S1673-8527(24)00152-8. [PMID: 38925347 DOI: 10.1016/j.jgg.2024.06.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Revised: 06/18/2024] [Accepted: 06/19/2024] [Indexed: 06/28/2024]
Abstract
Dendritic morphology is typically highly branched, and the branching and synaptic abundance of dendrites can enhance the receptive range of neurons and the diversity of information received, thus providing the basis for information processing in the nervous system. Once dendritic development is aberrantly compromised or damaged, it may lead to abnormal connectivity of the neural network, affecting the function and stability of the nervous system and ultimately triggering a series of neurological disorders. Research on the regulation of dendritic developmental processes has flourished, and much progress is now being made in its regulatory mechanisms. Noteworthily, dendrites are characterized by an extremely complex dendritic arborization that cannot be attributed to individual protein functions alone, requiring a systematic analysis of the intrinsic and extrinsic signals and the coordinated roles among them. Actin cytoskeleton organization and membrane vesicle trafficking are required during dendrite development, with actin providing tracks for vesicles and vesicle trafficking in turn providing material for actin assembly. In this review, we focus on these two basic biological processes and discuss the molecular mechanisms and their synergistic effects underlying the morphogenesis of neuronal dendrites. We also offer insights and discuss strategies for the potential preventive and therapeutic treatment of neuropsychiatric disorders.
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Affiliation(s)
- Wanting Wang
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, Jiangsu 210031, China
| | - Menglong Rui
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, Jiangsu 210031, China.
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5
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Tan JYK, Chew LY, Juhász G, Yu F. Interplay between autophagy and CncC regulates dendrite pruning in Drosophila. Proc Natl Acad Sci U S A 2024; 121:e2310740121. [PMID: 38408233 PMCID: PMC10927499 DOI: 10.1073/pnas.2310740121] [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: 07/02/2023] [Accepted: 01/26/2024] [Indexed: 02/28/2024] Open
Abstract
Autophagy is essential for the turnover of damaged organelles and long-lived proteins. It is responsible for many biological processes such as maintaining brain functions and aging. Impaired autophagy is often linked to neurodevelopmental and neurodegenerative diseases in humans. However, the role of autophagy in neuronal pruning during development remains poorly understood. Here, we report that autophagy regulates dendrite-specific pruning of ddaC sensory neurons in parallel to local caspase activation. Impaired autophagy causes the formation of ubiquitinated protein aggregates in ddaC neurons, dependent on the autophagic receptor Ref(2)P. Furthermore, the metabolic regulator AMP-activated protein kinase and the insulin-target of rapamycin pathway act upstream to regulate autophagy during dendrite pruning. Importantly, autophagy is required to activate the transcription factor CncC (Cap "n" collar isoform C), thereby promoting dendrite pruning. Conversely, CncC also indirectly affects autophagic activity via proteasomal degradation, as impaired CncC results in the inhibition of autophagy through sequestration of Atg8a into ubiquitinated protein aggregates. Thus, this study demonstrates the important role of autophagy in activating CncC prior to dendrite pruning, and further reveals an interplay between autophagy and CncC in neuronal pruning.
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Affiliation(s)
- Jue Yu Kelly Tan
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore117604, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore117543, Singapore
| | - Liang Yuh Chew
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore117604, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore117543, Singapore
| | - Gábor Juhász
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, BudapestH-1117, Hungary
- Institute of Genetics, Biological Research Centre, SzegedH-6726, Hungary
| | - Fengwei Yu
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore117604, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore117543, Singapore
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6
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Rajan S, Yoon J, Wu H, Srapyan S, Baskar R, Ahmed G, Yang T, Grintsevich EE, Reisler E, Terman JR. Disassembly of bundled F-actin and cellular remodeling via an interplay of Mical, cofilin, and F-actin crosslinkers. Proc Natl Acad Sci U S A 2023; 120:e2309955120. [PMID: 37725655 PMCID: PMC10523612 DOI: 10.1073/pnas.2309955120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 08/11/2023] [Indexed: 09/21/2023] Open
Abstract
Cellular form and function are controlled by the assembly and stability of actin cytoskeletal structures-but disassembling/pruning these structures is equally essential for the plasticity and remodeling that underlie behavioral adaptations. Importantly, the mechanisms of actin assembly have been well-defined-including that it is driven by actin's polymerization into filaments (F-actin) and then often bundling by crosslinking proteins into stable higher-order structures. In contrast, it remains less clear how these stable bundled F-actin structures are rapidly disassembled. We now uncover mechanisms that rapidly and extensively disassemble bundled F-actin. Using biochemical, structural, and imaging assays with purified proteins, we show that F-actin bundled with one of the most prominent crosslinkers, fascin, is extensively disassembled by Mical, the F-actin disassembly enzyme. Furthermore, the product of this Mical effect, Mical-oxidized actin, is poorly bundled by fascin, thereby further amplifying Mical's disassembly effects on bundled F-actin. Moreover, another critical F-actin regulator, cofilin, also affects fascin-bundled filaments, but we find herein that it synergizes with Mical to dramatically amplify its disassembly of bundled F-actin compared to the sum of their individual effects. Genetic and high-resolution cellular assays reveal that Mical also counteracts crosslinking proteins/bundled F-actin in vivo to control cellular extension, axon guidance, and Semaphorin/Plexin cell-cell repulsion. Yet, our results also support the idea that fascin-bundling serves to dampen Mical's F-actin disassembly in vitro and in vivo-and that physiologically relevant cellular remodeling requires a fine-tuned interplay between the factors that build bundled F-actin networks and those that disassemble them.
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Affiliation(s)
- Sudeepa Rajan
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA90095
| | - Jimok Yoon
- Department of Neuroscience, The University of Texas of Southwestern Medical Center, Dallas, TX75390
- Department of Pharmacology, The University of Texas of Southwestern Medical Center, Dallas, TX75390
| | - Heng Wu
- Department of Neuroscience, The University of Texas of Southwestern Medical Center, Dallas, TX75390
- Department of Pharmacology, The University of Texas of Southwestern Medical Center, Dallas, TX75390
| | - Sargis Srapyan
- Department of Chemistry and Biochemistry, California State University, Long Beach, CA90840
| | - Raju Baskar
- Department of Neuroscience, The University of Texas of Southwestern Medical Center, Dallas, TX75390
- Department of Pharmacology, The University of Texas of Southwestern Medical Center, Dallas, TX75390
| | - Giasuddin Ahmed
- Department of Neuroscience, The University of Texas of Southwestern Medical Center, Dallas, TX75390
- Department of Pharmacology, The University of Texas of Southwestern Medical Center, Dallas, TX75390
| | - Taehong Yang
- Department of Neuroscience, The University of Texas of Southwestern Medical Center, Dallas, TX75390
- Department of Pharmacology, The University of Texas of Southwestern Medical Center, Dallas, TX75390
| | - Elena E. Grintsevich
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA90095
- Department of Chemistry and Biochemistry, California State University, Long Beach, CA90840
| | - Emil Reisler
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA90095
- Molecular Biology Institute, University of California, Los Angeles, CA90095
| | - Jonathan R. Terman
- Department of Neuroscience, The University of Texas of Southwestern Medical Center, Dallas, TX75390
- Department of Pharmacology, The University of Texas of Southwestern Medical Center, Dallas, TX75390
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7
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Rui M, Kong W, Wang W, Zheng T, Wang S, Xie W. Droj2 Facilitates Somatosensory Neurite Sculpting via GTP-Binding Protein Arf102F in Drosophila. Int J Mol Sci 2023; 24:13213. [PMID: 37686022 PMCID: PMC10487878 DOI: 10.3390/ijms241713213] [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: 07/12/2023] [Revised: 08/21/2023] [Accepted: 08/23/2023] [Indexed: 09/10/2023] Open
Abstract
Developmental remodeling of neurite is crucial for the accurate wiring of neural circuits in the developing nervous system in both vertebrates and invertebrates, and may also contribute to the pathogenesis of neuropsychiatric disorders, for instance, autism, Alzheimer's disease (AD), and schizophrenia. However, the molecular underpinnings underlying developmental remodeling are still not fully understood. Here, we have identified DnaJ-like-2 (Droj2), orthologous to human DNAJA1 and DNAJA4 that is predicted to be involved in protein refolding, as a developmental signal promoting dendrite sculpting of the class IV dendritic arborization (C4da) sensory neuron in Drosophila. We further show that Arf102F, a GTP-binding protein previously implicated in protein trafficking, serves downstream of Droj2 to govern neurite pruning of C4da sensory neurons. Intriguingly, our data consistently demonstrate that both Droj2 and Arf102F promote the downregulation of the conserved L1-type cell-adhesion molecule Neuroglian anterior to dendrite pruning. Mechanistically, Droj2 genetically interacts with Arf102F and promotes Neuroglian downregulation to initiate dendrite severing. Taken together, this systematic study sheds light on an unprecedented function of Droj2 and Arf102F in neuronal development.
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Affiliation(s)
- Menglong Rui
- The Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing 210096, China
| | - Weiyu Kong
- The Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing 210096, China
| | - Wanting Wang
- The Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing 210096, China
| | - Ting Zheng
- The Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing 210096, China
| | - Su Wang
- The Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing 210096, China
- Co-Innovation Center of Neuroregeneration, Nantong University, Nantong 226019, China
| | - Wei Xie
- The Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing 210096, China
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8
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Sanal N, Keding L, Gigengack U, Michalke E, Rumpf S. TORC1 regulation of dendrite regrowth after pruning is linked to actin and exocytosis. PLoS Genet 2023; 19:e1010526. [PMID: 37167328 DOI: 10.1371/journal.pgen.1010526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 05/23/2023] [Accepted: 04/14/2023] [Indexed: 05/13/2023] Open
Abstract
Neurite pruning and regrowth are important mechanisms to adapt neural circuits to distinct developmental stages. Neurite regrowth after pruning often depends on differential regulation of growth signaling pathways, but their precise mechanisms of action during regrowth are unclear. Here, we show that the PI3K/TORC1 pathway is required for dendrite regrowth after pruning in Drosophila peripheral neurons during metamorphosis. TORC1 impinges on translation initiation, and our analysis of 5' untranslated regions (UTRs) of remodeling factor mRNAs linked to actin suggests that TOR selectively stimulates the translation of regrowth over pruning factors. Furthermore, we find that dendrite regrowth also requires the GTPase RalA and the exocyst complex as regulators of polarized secretion, and we provide evidence that this pathway is also regulated by TOR. We propose that TORC1 coordinates dendrite regrowth after pruning by coordinately stimulating the translation of regrowth factors involved in cytoskeletal regulation and secretion.
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Affiliation(s)
- Neeraja Sanal
- Multiscale Imaging Center, University of Münster, Münster, Germany
| | - Lorena Keding
- Multiscale Imaging Center, University of Münster, Münster, Germany
| | - Ulrike Gigengack
- Multiscale Imaging Center, University of Münster, Münster, Germany
| | - Esther Michalke
- Multiscale Imaging Center, University of Münster, Münster, Germany
| | - Sebastian Rumpf
- Multiscale Imaging Center, University of Münster, Münster, Germany
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Rumpf S, Sanal N, Marzano M. Energy metabolic pathways in neuronal development and function. OXFORD OPEN NEUROSCIENCE 2023; 2:kvad004. [PMID: 38596236 PMCID: PMC10913822 DOI: 10.1093/oons/kvad004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 03/18/2023] [Accepted: 03/20/2023] [Indexed: 04/11/2024]
Abstract
Neuronal development and function are known to be among the most energy-demanding functions of the body. Constant energetic support is therefore crucial at all stages of a neuron's life. The two main adenosine triphosphate (ATP)-producing pathways in cells are glycolysis and oxidative phosphorylation. Glycolysis has a relatively low yield but provides fast ATP and enables the metabolic versatility needed in dividing neuronal stem cells. Oxidative phosphorylation, on the other hand, is highly efficient and therefore thought to provide most or all ATP in differentiated neurons. However, it has recently become clear that due to their distinct properties, both pathways are required to fully satisfy neuronal energy demands during development and function. Here, we provide an overview of how glycolysis and oxidative phosphorylation are used in neurons during development and function.
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Affiliation(s)
- Sebastian Rumpf
- Correspondence address. Multiscale Imaging Center, University of Münster, Röntgenstrasse 16, 48149 Münster, Germany. E-mail:
| | - Neeraja Sanal
- Multiscale Imaging Center, University of Münster, Röntgenstrasse 16, 48149 Münster, Germany
| | - Marco Marzano
- Multiscale Imaging Center, University of Münster, Röntgenstrasse 16, 48149 Münster, Germany
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10
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Truman JW, Riddiford LM. Drosophila postembryonic nervous system development: a model for the endocrine control of development. Genetics 2023; 223:iyac184. [PMID: 36645270 PMCID: PMC9991519 DOI: 10.1093/genetics/iyac184] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 12/13/2022] [Indexed: 01/17/2023] Open
Abstract
During postembryonic life, hormones, including ecdysteroids, juvenile hormones, insulin-like peptides, and activin/TGFβ ligands act to transform the larval nervous system into an adult version, which is a fine-grained mosaic of recycled larval neurons and adult-specific neurons. Hormones provide both instructional signals that make cells competent to undergo developmental change and timing cues to evoke these changes across the nervous system. While touching on all the above hormones, our emphasis is on the ecdysteroids, ecdysone and 20-hydroxyecdysone (20E). These are the prime movers of insect molting and metamorphosis and are involved in all phases of nervous system development, including neurogenesis, pruning, arbor outgrowth, and cell death. Ecdysteroids appear as a series of steroid peaks that coordinate the larval molts and the different phases of metamorphosis. Each peak directs a stereotyped cascade of transcription factor expression. The cascade components then direct temporal programs of effector gene expression, but the latter vary markedly according to tissue and life stage. The neurons read the ecdysteroid titer through various isoforms of the ecdysone receptor, a nuclear hormone receptor. For example, at metamorphosis the pruning of larval neurons is mediated through the B isoforms, which have strong activation functions, whereas subsequent outgrowth is mediated through the A isoform through which ecdysteroids play a permissive role to allow local tissue interactions to direct outgrowth. The major circulating ecdysteroid can also change through development. During adult development ecdysone promotes early adult patterning and differentiation while its metabolite, 20E, later evokes terminal adult differentiation.
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Affiliation(s)
- James W Truman
- Friday Harbor Laboratories, University of Washington, Friday Harbor, WA 98250, USA
- Department of Biology, University of Washington, Box 351800, Seattle, WA 98195, USA
| | - Lynn M Riddiford
- Friday Harbor Laboratories, University of Washington, Friday Harbor, WA 98250, USA
- Department of Biology, University of Washington, Box 351800, Seattle, WA 98195, USA
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11
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Rajan S, Terman JR, Reisler E. MICAL-mediated oxidation of actin and its effects on cytoskeletal and cellular dynamics. Front Cell Dev Biol 2023; 11:1124202. [PMID: 36875759 PMCID: PMC9982024 DOI: 10.3389/fcell.2023.1124202] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 02/02/2023] [Indexed: 02/19/2023] Open
Abstract
Actin and its dynamic structural remodelings are involved in multiple cellular functions, including maintaining cell shape and integrity, cytokinesis, motility, navigation, and muscle contraction. Many actin-binding proteins regulate the cytoskeleton to facilitate these functions. Recently, actin's post-translational modifications (PTMs) and their importance to actin functions have gained increasing recognition. The MICAL family of proteins has emerged as important actin regulatory oxidation-reduction (Redox) enzymes, influencing actin's properties both in vitro and in vivo. MICALs specifically bind to actin filaments and selectively oxidize actin's methionine residues 44 and 47, which perturbs filaments' structure and leads to their disassembly. This review provides an overview of the MICALs and the impact of MICAL-mediated oxidation on actin's properties, including its assembly and disassembly, effects on other actin-binding proteins, and on cells and tissue systems.
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Affiliation(s)
- Sudeepa Rajan
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, United States
| | - Jonathan R. Terman
- Departments of Neuroscience and Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Emil Reisler
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, United States
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA, United States
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12
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Bu S, Lau SSY, Yong WL, Zhang H, Thiagarajan S, Bashirullah A, Yu F. Polycomb group genes are required for neuronal pruning in Drosophila. BMC Biol 2023; 21:33. [PMID: 36793038 PMCID: PMC9933400 DOI: 10.1186/s12915-023-01534-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 02/02/2023] [Indexed: 02/17/2023] Open
Abstract
BACKGROUND Pruning that selectively eliminates unnecessary or incorrect neurites is required for proper wiring of the mature nervous system. During Drosophila metamorphosis, dendritic arbourization sensory neurons (ddaCs) and mushroom body (MB) γ neurons can selectively prune their larval dendrites and/or axons in response to the steroid hormone ecdysone. An ecdysone-induced transcriptional cascade plays a key role in initiating neuronal pruning. However, how downstream components of ecdysone signalling are induced remains not entirely understood. RESULTS Here, we identify that Scm, a component of Polycomb group (PcG) complexes, is required for dendrite pruning of ddaC neurons. We show that two PcG complexes, PRC1 and PRC2, are important for dendrite pruning. Interestingly, depletion of PRC1 strongly enhances ectopic expression of Abdominal B (Abd-B) and Sex combs reduced, whereas loss of PRC2 causes mild upregulation of Ultrabithorax and Abdominal A in ddaC neurons. Among these Hox genes, overexpression of Abd-B causes the most severe pruning defects, suggesting its dominant effect. Knockdown of the core PRC1 component Polyhomeotic (Ph) or Abd-B overexpression selectively downregulates Mical expression, thereby inhibiting ecdysone signalling. Finally, Ph is also required for axon pruning and Abd-B silencing in MB γ neurons, indicating a conserved function of PRC1 in two types of pruning. CONCLUSIONS This study demonstrates important roles of PcG and Hox genes in regulating ecdysone signalling and neuronal pruning in Drosophila. Moreover, our findings suggest a non-canonical and PRC2-independent role of PRC1 in Hox gene silencing during neuronal pruning.
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Affiliation(s)
- Shufeng Bu
- grid.4280.e0000 0001 2180 6431Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, 117604 Singapore ,grid.4280.e0000 0001 2180 6431Department of Biological Sciences, National University of Singapore, Singapore, 117543 Singapore
| | - Samuel Song Yuan Lau
- grid.4280.e0000 0001 2180 6431Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, 117604 Singapore
| | - Wei Lin Yong
- grid.4280.e0000 0001 2180 6431Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, 117604 Singapore
| | - Heng Zhang
- grid.4280.e0000 0001 2180 6431Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, 117604 Singapore
| | - Sasinthiran Thiagarajan
- grid.4280.e0000 0001 2180 6431Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, 117604 Singapore ,grid.4280.e0000 0001 2180 6431Department of Biological Sciences, National University of Singapore, Singapore, 117543 Singapore
| | - Arash Bashirullah
- grid.14003.360000 0001 2167 3675Division of Pharmaceutical Sciences, University of Wisconsin-Madison, Madison, WI 53705-2222 USA
| | - Fengwei Yu
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, 117604, Singapore. .,Department of Biological Sciences, National University of Singapore, Singapore, 117543, Singapore.
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13
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Krämer R, Wolterhoff N, Galic M, Rumpf S. Developmental pruning of sensory neurites by mechanical tearing in Drosophila. J Cell Biol 2023; 222:213805. [PMID: 36648440 PMCID: PMC9856751 DOI: 10.1083/jcb.202205004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 08/24/2022] [Accepted: 01/04/2023] [Indexed: 01/18/2023] Open
Abstract
Mechanical forces actively shape cells during development, but little is known about their roles during neuronal morphogenesis. Developmental neurite pruning, a critical circuit specification mechanism, often involves neurite abscission at predetermined sites by unknown mechanisms. Pruning of Drosophila sensory neuron dendrites during metamorphosis is triggered by the hormone ecdysone, which induces local disassembly of the dendritic cytoskeleton. Subsequently, dendrites are severed at positions close to the soma by an unknown mechanism. We found that ecdysone signaling causes the dendrites to become mechanically fragile. Severing occurs during periods of increased pupal morphogenetic tissue movements, which exert mechanical forces on the destabilized dendrites. Tissue movements and dendrite severing peak during pupal ecdysis, a period of strong abdominal contractions, and abolishing ecdysis causes non-cell autonomous dendrite pruning defects. Thus, our data establish mechanical tearing as a novel mechanism during neurite pruning.
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Affiliation(s)
- Rafael Krämer
- https://ror.org/00pd74e08Institute for Neurobiology, University of Münster, Münster, Germany
| | - Neele Wolterhoff
- https://ror.org/00pd74e08Institute for Neurobiology, University of Münster, Münster, Germany
| | - Milos Galic
- Institute of Medical Physics and Biophysics, University of Münster, Münster, Germany
| | - Sebastian Rumpf
- https://ror.org/00pd74e08Institute for Neurobiology, University of Münster, Münster, Germany
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14
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Lin S. The making of the Drosophila mushroom body. Front Physiol 2023; 14:1091248. [PMID: 36711013 PMCID: PMC9880076 DOI: 10.3389/fphys.2023.1091248] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 01/02/2023] [Indexed: 01/14/2023] Open
Abstract
The mushroom body (MB) is a computational center in the Drosophila brain. The intricate neural circuits of the mushroom body enable it to store associative memories and process sensory and internal state information. The mushroom body is composed of diverse types of neurons that are precisely assembled during development. Tremendous efforts have been made to unravel the molecular and cellular mechanisms that build the mushroom body. However, we are still at the beginning of this challenging quest, with many key aspects of mushroom body assembly remaining unexplored. In this review, I provide an in-depth overview of our current understanding of mushroom body development and pertinent knowledge gaps.
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15
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Xu W, Kong W, Gao Z, Huang E, Xie W, Wang S, Rui M. Establishment of a novel axon pruning model of Drosophila motor neuron. Biol Open 2023; 12:286282. [PMID: 36606515 PMCID: PMC9838636 DOI: 10.1242/bio.059535] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 11/30/2022] [Indexed: 01/07/2023] Open
Abstract
Developmental neuronal pruning is a process by which neurons selectively remove excessive or unnecessary neurite without causing neuronal death. Importantly, this process is widely used for the refinement of neural circuits in both vertebrates and invertebrates, and may also contribute to the pathogenesis of neuropsychiatric disorders, such as autism and schizophrenia. In the peripheral nervous system (PNS), class IV dendritic arborization (da) sensory neurons of Drosophila, selectively remove the dendrites without losing their somas and axons, while the dendrites and axons of mushroom body (MB) γ neuron in the central nervous system (CNS) are eliminated by localized fragmentation during metamorphosis. Alternatively, dendrite pruning of ddaC neurons is usually investigated via live-cell imaging, while dissection and fixation are currently used for evaluating MB γ neuron axon pruning. Thus, an excellent model system to assess axon specific pruning directly via live-cell imaging remains elusive. Here, we report that the Drosophila motor neuron offers a unique advantage for studying axon pruning. Interestingly, we uncover that long-range projecting axon bundle from soma at ventral nerve cord (VNC), undergoes degeneration rather than retraction during metamorphosis. Strikingly, the pruning process of the motor axon bundle is straightforward to investigate via live imaging and it occurs approximately at 22 h after pupal formation (APF), when axon bundles are completely cleared. Consistently, the classical axon pruning regulators in the Drosophila MB γ neuron, including TGF-β signaling, ecdysone signaling, JNK signaling, and the ubiquitin-proteasome system are also involved in governing motor axon pruning. Finally, our findings establish an unprecedented axon pruning mode that will serve to systematically screen and identify undiscovered axon pruning regulators. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Wanyue Xu
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, 2 Sipailou Road, Nanjing 210096, China
| | - Weiyu Kong
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, 2 Sipailou Road, Nanjing 210096, China
| | - Ziyang Gao
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, 2 Sipailou Road, Nanjing 210096, China
| | - Erqian Huang
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, 2 Sipailou Road, Nanjing 210096, China
| | - Wei Xie
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, 2 Sipailou Road, Nanjing 210096, China
| | - Su Wang
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, 2 Sipailou Road, Nanjing 210096, China,Authors for correspondence (; )
| | - Menglong Rui
- School of Life Science and Technology, the Key Laboratory of Developmental Genes and Human Disease, Southeast University, 2 Sipailou Road, Nanjing 210096, China,Authors for correspondence (; )
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16
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Wang Y, Lee H, Fear JM, Berger I, Oliver B, Przytycka TM. NetREX-CF integrates incomplete transcription factor data with gene expression to reconstruct gene regulatory networks. Commun Biol 2022; 5:1282. [PMID: 36418514 PMCID: PMC9684490 DOI: 10.1038/s42003-022-04226-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 11/04/2022] [Indexed: 11/25/2022] Open
Abstract
The inference of Gene Regulatory Networks (GRNs) is one of the key challenges in systems biology. Leading algorithms utilize, in addition to gene expression, prior knowledge such as Transcription Factor (TF) DNA binding motifs or results of TF binding experiments. However, such prior knowledge is typically incomplete, therefore, integrating it with gene expression to infer GRNs remains difficult. To address this challenge, we introduce NetREX-CF-Regulatory Network Reconstruction using EXpression and Collaborative Filtering-a GRN reconstruction approach that brings together Collaborative Filtering to address the incompleteness of the prior knowledge and a biologically justified model of gene expression (sparse Network Component Analysis based model). We validated the NetREX-CF using Yeast data and then used it to construct the GRN for Drosophila Schneider 2 (S2) cells. To corroborate the GRN, we performed a large-scale RNA-Seq analysis followed by a high-throughput RNAi treatment against all 465 expressed TFs in the cell line. Our knockdown result has not only extensively validated the GRN we built, but also provides a benchmark that our community can use for evaluating GRNs. Finally, we demonstrate that NetREX-CF can infer GRNs using single-cell RNA-Seq, and outperforms other methods, by using previously published human data.
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Affiliation(s)
- Yijie Wang
- Computer Science Department, Indiana University, Bloomington, IN, 47408, USA.
| | - Hangnoh Lee
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, 50 South Drive, Bethesda, MD, 20892, USA
| | - Justin M Fear
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, 50 South Drive, Bethesda, MD, 20892, USA
| | - Isabelle Berger
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, 50 South Drive, Bethesda, MD, 20892, USA
| | - Brian Oliver
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, 50 South Drive, Bethesda, MD, 20892, USA.
| | - Teresa M Przytycka
- National Center of Biotechnology Information, National Library of Medicine, NIH, Bethesda, MD, 20894, USA.
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17
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Dzaki N, Bu S, Lau SSY, Yong WL, Yu F. Drosophila GSK3β promotes microtubule disassembly and dendrite pruning in sensory neurons. Development 2022; 149:281771. [PMID: 36264221 DOI: 10.1242/dev.200844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 10/06/2022] [Indexed: 11/17/2022]
Abstract
The evolutionarily conserved Glycogen Synthase Kinase 3β (GSK3β), a negative regulator of microtubules, is crucial for neuronal polarization, growth and migration during animal development. However, it remains unknown whether GSK3β regulates neuronal pruning, which is a regressive process. Here, we report that the Drosophila GSK3β homologue Shaggy (Sgg) is cell-autonomously required for dendrite pruning of ddaC sensory neurons during metamorphosis. Sgg is necessary and sufficient to promote microtubule depolymerization, turnover and disassembly in the dendrites. Although Sgg is not required for the minus-end-out microtubule orientation in dendrites, hyperactivated Sgg can disturb the dendritic microtubule orientation. Moreover, our pharmacological and genetic data suggest that Sgg is required to promote dendrite pruning at least partly via microtubule disassembly. We show that Sgg and Par-1 kinases act synergistically to promote microtubule disassembly and dendrite pruning. Thus, Sgg and Par-1 might converge on and phosphorylate a common downstream microtubule-associated protein(s) to disassemble microtubules and thereby facilitate dendrite pruning.
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Affiliation(s)
- Najat Dzaki
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604
| | - Shufeng Bu
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604.,Department of Biological Sciences, National University of Singapore, Singapore 117543
| | - Samuel Song Yuan Lau
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604
| | - Wei Lin Yong
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604
| | - Fengwei Yu
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604.,Department of Biological Sciences, National University of Singapore, Singapore 117543
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18
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Wen P, Wang H, Li Y, Sui X, Hou Z, Guo X, Xue W, Liu D, Wang Y, Gao J. MICALL2 as a substrate of ubiquitinase TRIM21 regulates tumorigenesis of colorectal cancer. Cell Commun Signal 2022; 20:170. [DOI: 10.1186/s12964-022-00984-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 10/01/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Molecule interacting with CasL-like protein 2 (MICALL2) is believed to regulate cytoskeleton dynamics, tight junction formation, and neurite outgrowth. However, its biological role and the underlying mechanism in colorectal cancer (CRC) remain largely elusive.
Methods
qRT-PCR, Western blotting and immunohistochemistry assays were used to detect the expression levels of different genes. Next, mass spectrometry, co-immunoprecipitation and immunofluorescence staining were used to detect the interactions of proteins. Furthermore, MTT assay, colony formation assay, wound-healing assays and xenograft tumor models were performed to demonstrate the functions of MICALL2 in CRC. In addition, transcriptome sequencing and Western blotting were conducted to verify the mechanism of MICALL2 in CRC.
Results
We found that both mRNA and protein levels of MICALL2 are up-regulated in colorectal cancer tissues compared with non-tumor tissues and that its overexpression is closely correlated with poor prognosis. Ubiquitin E3 ligase Tripartite motif-containing protein 21 (TRIM21) mediated MICALL2 ubiquitination and proteasome-dependent degradation, negatively correlated with MICALL2 levels, and reversely regulated the tumorigenic activity of MICALL2 in CRC. Functional studies confirmed that MICALL2 promoted colorectal cancer cell growth and migration via the Wnt/β-catenin signaling pathway.
Conclusions
As a substrate of ubiquitinase TRIM21, MICALL2 enhances the growth and migration of colorectal cancer cells and activates the Wnt/β-catenin signaling pathway.
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19
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Yuh Chew L, He J, Wong JJL, Li S, Yu F. AMPK activates the Nrf2-Keap1 pathway to govern dendrite pruning via the insulin pathway in Drosophila. Development 2022; 149:275791. [DOI: 10.1242/dev.200536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 06/16/2022] [Indexed: 11/20/2022]
Abstract
ABSTRACT
During Drosophila metamorphosis, the ddaC dendritic arborisation sensory neurons selectively prune their larval dendrites in response to steroid hormone ecdysone signalling. The Nrf2-Keap1 pathway acts downstream of ecdysone signalling to promote proteasomal degradation and thereby dendrite pruning. However, how the Nrf2-Keap1 pathway is activated remains largely unclear. Here, we demonstrate that the metabolic regulator AMP-activated protein kinase (AMPK) plays a cell-autonomous role in dendrite pruning. Importantly, AMPK is required for Mical and Headcase expression and for activation of the Nrf2-Keap1 pathway. We reveal that AMPK promotes the Nrf2-Keap1 pathway and dendrite pruning partly via inhibition of the insulin pathway. Moreover, the AMPK-insulin pathway is required for ecdysone signalling to activate the Nrf2-Keap1 pathway during dendrite pruning. Overall, this study reveals an important mechanism whereby ecdysone signalling activates the Nrf2-Keap1 pathway via the AMPK-insulin pathway to promote dendrite pruning, and further suggests that during the nonfeeding prepupal stage metabolic alterations lead to activation of the Nrf2-Keap1 pathway and dendrite pruning.
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Affiliation(s)
- Liang Yuh Chew
- 1 Research Link, National University of Singapore 1 Temasek Life Sciences Laboratory , , 117604 , Singapore
- National University of Singapore 2 Department of Biological Sciences , , 117543 , Singapore
| | - Jianzheng He
- 1 Research Link, National University of Singapore 1 Temasek Life Sciences Laboratory , , 117604 , Singapore
| | - Jack Jing Lin Wong
- 1 Research Link, National University of Singapore 1 Temasek Life Sciences Laboratory , , 117604 , Singapore
| | - Sheng Li
- Institute of Insect Science and Technology & School of Life Sciences, South China Normal University 3 Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology , , Guangzhou 510631 , China
| | - Fengwei Yu
- 1 Research Link, National University of Singapore 1 Temasek Life Sciences Laboratory , , 117604 , Singapore
- National University of Singapore 2 Department of Biological Sciences , , 117543 , Singapore
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20
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Rouyère C, Serrano T, Frémont S, Echard A. Oxidation and reduction of actin: Origin, impact in vitro and functional consequences in vivo. Eur J Cell Biol 2022; 101:151249. [PMID: 35716426 DOI: 10.1016/j.ejcb.2022.151249] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/13/2022] [Accepted: 06/06/2022] [Indexed: 11/15/2022] Open
Abstract
Actin is among the most abundant proteins in eukaryotic cells and assembles into dynamic filamentous networks regulated by many actin binding proteins. The actin cytoskeleton must be finely tuned, both in space and time, to fulfill key cellular functions such as cell division, cell shape changes, phagocytosis and cell migration. While actin oxidation by reactive oxygen species (ROS) at non-physiological levels are known for long to impact on actin polymerization and on the cellular actin cytoskeleton, growing evidence shows that direct and reversible oxidation/reduction of specific actin amino acids plays an important and physiological role in regulating the actin cytoskeleton. In this review, we describe which actin amino acid residues can be selectively oxidized and reduced in many different ways (e.g. disulfide bond formation, glutathionylation, carbonylation, nitration, nitrosylation and other oxidations), the cellular enzymes at the origin of these post-translational modifications, and the impact of actin redox modifications both in vitro and in vivo. We show that the regulated balance of oxidation and reduction of key actin amino acid residues contributes to the control of actin filament polymerization and disassembly at the subcellular scale and highlight how improper redox modifications of actin can lead to pathological conditions.
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Affiliation(s)
- Clémentine Rouyère
- Institut Pasteur, Université Paris Cité, CNRS UMR3691, Membrane Traffic and Cell Division Unit, 25-28 rue du Dr Roux, F-75015 Paris, France; Sorbonne Université, Collège Doctoral, F-75005 Paris, France
| | - Thomas Serrano
- Institut Pasteur, Université Paris Cité, CNRS UMR3691, Membrane Traffic and Cell Division Unit, 25-28 rue du Dr Roux, F-75015 Paris, France
| | - Stéphane Frémont
- Institut Pasteur, Université Paris Cité, CNRS UMR3691, Membrane Traffic and Cell Division Unit, 25-28 rue du Dr Roux, F-75015 Paris, France
| | - Arnaud Echard
- Institut Pasteur, Université Paris Cité, CNRS UMR3691, Membrane Traffic and Cell Division Unit, 25-28 rue du Dr Roux, F-75015 Paris, France.
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21
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Bu S, Tang Q, Wang Y, Lau SSY, Yong WL, Yu F. Drosophila CLASP regulates microtubule orientation and dendrite pruning by suppressing Par-1 kinase. Cell Rep 2022; 39:110887. [PMID: 35649352 DOI: 10.1016/j.celrep.2022.110887] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 04/04/2022] [Accepted: 05/06/2022] [Indexed: 02/06/2023] Open
Abstract
The evolutionarily conserved CLASPs (cytoplasmic linker-associated proteins) are microtubule-associated proteins that inhibit microtubule catastrophe and promote rescue. CLASPs can regulate axonal elongation and dendrite branching in growing neurons. However, their roles in microtubule orientation and neurite pruning in remodeling neurons remain unknown. Here, we identify the Drosophila CLASP homolog Orbit/MAST, which is required for dendrite pruning in ddaC sensory neurons during metamorphosis. Orbit is important for maintenance of the minus-end-out microtubule orientation in ddaC dendrites. Our structural analysis reveals that the microtubule lattice-binding TOG2 domain is required for Orbit to regulate dendritic microtubule orientation and dendrite pruning. In a genetic modifier screen, we further identify the conserved Par-1 kinase as a suppressor of Orbit in dendritic microtubule orientation. Moreover, elevated Par-1 function impairs dendritic microtubule orientation and dendrite pruning, phenocopying orbit mutants. Overall, our study demonstrates that Drosophila CLASP governs dendritic microtubule orientation and dendrite pruning at least partly via suppressing Par-1 kinase.
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Affiliation(s)
- Shufeng Bu
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, Singapore; Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Quan Tang
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, Singapore
| | - Yan Wang
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, Singapore
| | - Samuel Song Yuan Lau
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, Singapore
| | - Wei Lin Yong
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, Singapore
| | - Fengwei Yu
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore, Singapore; Department of Biological Sciences, National University of Singapore, Singapore, Singapore.
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22
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Prifti E, Tsakiri EN, Vourkou E, Stamatakis G, Samiotaki M, Skoulakis EMC, Papanikolopoulou K. Mical modulates Tau toxicity via cysteine oxidation in vivo. Acta Neuropathol Commun 2022; 10:44. [PMID: 35379354 PMCID: PMC8981811 DOI: 10.1186/s40478-022-01348-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 03/18/2022] [Indexed: 12/24/2022] Open
Abstract
Tau accumulation is clearly linked to pathogenesis in Alzheimer’s disease and other Tauopathies. However, processes leading to Tau fibrillization and reasons for its pathogenicity remain largely elusive. Mical emerged as a novel interacting protein of human Tau expressed in Drosophila brains. Mical is characterized by the presence of a flavoprotein monooxygenase domain that generates redox potential with which it can oxidize target proteins. In the well-established Drosophila Tauopathy model, we use genetic interactions to show that Mical alters Tau interactions with microtubules and the Actin cytoskeleton and greatly affects Tau aggregation propensity and Tau-associated toxicity and dysfunction. Exploration of the mechanism was pursued using a Mical inhibitor, a mutation in Mical that selectively disrupts its monooxygenase domain, Tau transgenes mutated at cysteine residues targeted by Mical and mass spectrometry analysis to quantify cysteine oxidation. The collective evidence strongly indicates that Mical’s redox activity mediates the effects on Tau via oxidation of Cys322. Importantly, we also validate results from the fly model in human Tauopathy samples by showing that MICAL1 is up-regulated in patient brains and co-localizes with Tau in Pick bodies. Our work provides mechanistic insights into the role of the Tau cysteine residues as redox-switches regulating the process of Tau self-assembly into inclusions in vivo, its function as a cytoskeletal protein and its effect on neuronal toxicity and dysfunction.
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23
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Jaszczak JS, DeVault L, Jan LY, Jan YN. Steroid hormone signaling activates thermal nociception during Drosophila peripheral nervous system development. eLife 2022; 11:e76464. [PMID: 35353036 PMCID: PMC8967384 DOI: 10.7554/elife.76464] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 03/07/2022] [Indexed: 12/27/2022] Open
Abstract
Sensory neurons enable animals to detect environmental changes and avoid harm. An intriguing open question concerns how the various attributes of sensory neurons arise in development. Drosophila melanogaster larvae undergo a behavioral transition by robustly activating a thermal nociceptive escape behavior during the second half of larval development (third instar). The Class IV dendritic arborization (C4da) neurons are multimodal sensors which tile the body wall of Drosophila larvae and detect nociceptive temperature, light, and mechanical force. In contrast to the increase in nociceptive behavior in the third instar, we find that ultraviolet light-induced Ca2+ activity in C4da neurons decreases during the same period of larval development. Loss of ecdysone receptor has previously been shown to reduce nociception in third instar larvae. We find that ligand-dependent activation of ecdysone signaling is sufficient to promote nociceptive responses in second instar larvae and suppress expression of subdued (encoding a TMEM16 channel). Reduction of subdued expression in second instar C4da neurons not only increases thermal nociception but also decreases the response to ultraviolet light. Thus, steroid hormone signaling suppresses subdued expression to facilitate the sensory switch of C4da neurons. This regulation of a developmental sensory switch through steroid hormone regulation of channel expression raises the possibility that ion channel homeostasis is a key target for tuning the development of sensory modalities.
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Affiliation(s)
- Jacob S Jaszczak
- Department of Physiology, Department of Biochemistry and Biophysics, University of California, San FranciscoSan FranciscoUnited States
- Howard Hughes Medical InstituteChevy ChaseUnited States
| | - Laura DeVault
- Department of Physiology, Department of Biochemistry and Biophysics, University of California, San FranciscoSan FranciscoUnited States
- Department of Developmental Biology, Washington University Medical SchoolSaint LouisUnited States
| | - Lily Yeh Jan
- Department of Physiology, Department of Biochemistry and Biophysics, University of California, San FranciscoSan FranciscoUnited States
- Howard Hughes Medical InstituteChevy ChaseUnited States
| | - Yuh Nung Jan
- Department of Physiology, Department of Biochemistry and Biophysics, University of California, San FranciscoSan FranciscoUnited States
- Howard Hughes Medical InstituteChevy ChaseUnited States
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24
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Janssens J, Aibar S, Taskiran II, Ismail JN, Gomez AE, Aughey G, Spanier KI, De Rop FV, González-Blas CB, Dionne M, Grimes K, Quan XJ, Papasokrati D, Hulselmans G, Makhzami S, De Waegeneer M, Christiaens V, Southall T, Aerts S. Decoding gene regulation in the fly brain. Nature 2022; 601:630-636. [PMID: 34987221 DOI: 10.1038/s41586-021-04262-z] [Citation(s) in RCA: 71] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 11/17/2021] [Indexed: 12/13/2022]
Abstract
The Drosophila brain is a frequently used model in neuroscience. Single-cell transcriptome analysis1-6, three-dimensional morphological classification7 and electron microscopy mapping of the connectome8,9 have revealed an immense diversity of neuronal and glial cell types that underlie an array of functional and behavioural traits in the fly. The identities of these cell types are controlled by gene regulatory networks (GRNs), involving combinations of transcription factors that bind to genomic enhancers to regulate their target genes. Here, to characterize GRNs at the cell-type level in the fly brain, we profiled the chromatin accessibility of 240,919 single cells spanning 9 developmental timepoints and integrated these data with single-cell transcriptomes. We identify more than 95,000 regulatory regions that are used in different neuronal cell types, of which 70,000 are linked to developmental trajectories involving neurogenesis, reprogramming and maturation. For 40 cell types, uniquely accessible regions were associated with their expressed transcription factors and downstream target genes through a combination of motif discovery, network inference and deep learning, creating enhancer GRNs. The enhancer architectures revealed by DeepFlyBrain lead to a better understanding of neuronal regulatory diversity and can be used to design genetic driver lines for cell types at specific timepoints, facilitating their characterization and manipulation.
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Affiliation(s)
- Jasper Janssens
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Sara Aibar
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Ibrahim Ihsan Taskiran
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Joy N Ismail
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | | | - Gabriel Aughey
- Department of Life Sciences, Imperial College London, London, UK
| | - Katina I Spanier
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Florian V De Rop
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Carmen Bravo González-Blas
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Marc Dionne
- Department of Life Sciences, Imperial College London, London, UK
| | - Krista Grimes
- Department of Life Sciences, Imperial College London, London, UK
| | - Xiao Jiang Quan
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Dafni Papasokrati
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Gert Hulselmans
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Samira Makhzami
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Maxime De Waegeneer
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Valerie Christiaens
- VIB Center for Brain & Disease Research, Leuven, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Tony Southall
- Department of Life Sciences, Imperial College London, London, UK
| | - Stein Aerts
- VIB Center for Brain & Disease Research, Leuven, Belgium. .,Department of Human Genetics, KU Leuven, Leuven, Belgium.
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25
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Gu H, Li Y, Cui X, Cao H, Hou Z, Ti Y, Liu D, Gao J, Wang Y, Wen P. MICAL1 inhibits colorectal cancer cell migration and proliferation by regulating the EGR1/β-catenin signaling pathway. Biochem Pharmacol 2022; 195:114870. [PMID: 34902339 DOI: 10.1016/j.bcp.2021.114870] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 11/18/2021] [Accepted: 12/03/2021] [Indexed: 12/26/2022]
Abstract
MICAL1 has been reported to be involved in the malignant processes of several types of cancer cells, however, the roles of MICAL1 in colorectal cancer (CRC) have not been well-characterized. This study aims to investigate the cellular functions and molecular mechanisms of MICAL1 in CRC cells. Here, we found that both mRNA and protein levels of MICAL1 were down-regulated in colorectal cancer tissues compared with matched adjacent non-tumor tissues, and the expression level of MICAL1 was correlated with the metastatic status of colorectal cancer. Importantly, overexpression of MICAL1 significantly inhibited colorectal cancer cell migration and growth, and increased the level of E-cadherin and Occludin, and suppressed the expression level of Vimentin and N-cadherin; while silencing of MICAL1 promoted CRC cell migration and enhanced EMT. In addition, MICAL1 overexpression significantly inhibited the proliferation and growth of CRC in vitro and in vivo. Moreover, RNA sequencing and bioinformatics analysis identified that MICAL1 was closely correlated with "cell migration", "cell cycle" and "β-catenin signaling" genesets. Mechanistically, overexpression of MICAL1 downregulated the mRNA level of EGR1 and β-catenin, decreased the protein level and nuclear translocation of β-catenin, and inhibited the transcriptions of β-catenin downstream targets, c-myc and cyclin D1. The ectopic expression of EGR1 or β-catenin can significantly block the MICAL1-mediated inhibitory effects. Collectively, MICAL1 is down-regulated in CRC, and plays an inhibitory role in the migration and growth of CRC cells by suppressing the ERG1/β-catenin signaling pathway.
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Affiliation(s)
- Huanyu Gu
- Department of Pathophysiology, Jinzhou Medical University, Jinzhou 121000, Liaoning, China
| | - Yi Li
- Department of Pathophysiology, Jinzhou Medical University, Jinzhou 121000, Liaoning, China
| | - Xiuping Cui
- Life Science Institute, Jinzhou Medical University, Jinzhou 121000, Liaoning, China
| | - Huiru Cao
- Department of Pathophysiology, Jinzhou Medical University, Jinzhou 121000, Liaoning, China
| | - Zhijuan Hou
- Department of Pathophysiology, Jinzhou Medical University, Jinzhou 121000, Liaoning, China
| | - Yunhe Ti
- Department of Pathophysiology, Jinzhou Medical University, Jinzhou 121000, Liaoning, China
| | - Dahua Liu
- Biological Anthropology Institute, Jinzhou Medical University, Jinzhou 121000, Liaoning, China
| | - Jing Gao
- Department of Ultrasonography, The First Affiliated Hospital of Jinzhou Medical University, Jinzhou 121001, China
| | - Yu Wang
- Life Science Institute, Jinzhou Medical University, Jinzhou 121000, Liaoning, China.
| | - Pushuai Wen
- Department of Pathophysiology, Jinzhou Medical University, Jinzhou 121000, Liaoning, China; Biological Anthropology Institute, Jinzhou Medical University, Jinzhou 121000, Liaoning, China.
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26
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Marzano M, Herzmann S, Elsbroek L, Sanal N, Tarbashevich K, Raz E, Krahn MP, Rumpf S. AMPK adapts metabolism to developmental energy requirement during dendrite pruning in Drosophila. Cell Rep 2021; 37:110024. [PMID: 34788610 DOI: 10.1016/j.celrep.2021.110024] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 07/30/2021] [Accepted: 10/28/2021] [Indexed: 10/19/2022] Open
Abstract
To reshape neuronal connectivity in adult stages, Drosophila sensory neurons prune their dendrites during metamorphosis using a genetic degeneration program that is induced by the steroid hormone ecdysone. Metamorphosis is a nonfeeding stage that imposes metabolic constraints on development. We find that AMP-activated protein kinase (AMPK), a regulator of energy homeostasis, is cell-autonomously required for dendrite pruning. AMPK is activated by ecdysone and promotes oxidative phosphorylation and pyruvate usage, likely to enable neurons to use noncarbohydrate metabolites such as amino acids for energy production. Loss of AMPK or mitochondrial deficiency causes specific defects in pruning factor translation and the ubiquitin-proteasome system. Our findings distinguish pruning from pathological neurite degeneration, which is often induced by defects in energy production, and highlight how metabolism is adapted to fit energy-costly developmental transitions.
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Affiliation(s)
- Marco Marzano
- Institute for Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany
| | - Svende Herzmann
- Institute for Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany
| | - Leonardo Elsbroek
- Institute for Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany
| | - Neeraja Sanal
- Institute for Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany
| | - Katsiaryna Tarbashevich
- Institute of Cell Biology, Center for Molecular Biology of Inflammation, University of Münster, 48149 Münster, Germany
| | - Erez Raz
- Institute of Cell Biology, Center for Molecular Biology of Inflammation, University of Münster, 48149 Münster, Germany
| | - Michael P Krahn
- Department of Medical Cell Biology, Medical Clinic D, University Hospital of Münster, Münster, Germany
| | - Sebastian Rumpf
- Institute for Neurobiology, University of Münster, Badestrasse 9, 48149 Münster, Germany.
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27
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Bu S, Yong WL, Lim BJW, Kondo S, Yu F. A systematic analysis of microtubule-destabilizing factors during dendrite pruning in Drosophila. EMBO Rep 2021; 22:e52679. [PMID: 34338441 DOI: 10.15252/embr.202152679] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 07/10/2021] [Accepted: 07/12/2021] [Indexed: 11/09/2022] Open
Abstract
It has long been thought that microtubule disassembly, one of the earliest cellular events, contributes to neuronal pruning and neurodegeneration in development and disease. However, how microtubule disassembly drives neuronal pruning remains poorly understood. Here, we conduct a systematic investigation of various microtubule-destabilizing factors and identify exchange factor for Arf6 (Efa6) and Stathmin (Stai) as new regulators of dendrite pruning in ddaC sensory neurons during Drosophila metamorphosis. We show that Efa6 is both necessary and sufficient to regulate dendrite pruning. Interestingly, Efa6 and Stai facilitate microtubule turnover and disassembly prior to dendrite pruning without compromising the minus-end-out microtubule orientation in dendrites. Moreover, our pharmacological and genetic manipulations strongly support a key role of microtubule disassembly in promoting dendrite pruning. Thus, this systematic study highlights the importance of two selective microtubule destabilizers in dendrite pruning and substantiates a causal link between microtubule disassembly and neuronal pruning.
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Affiliation(s)
- Shufeng Bu
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Wei Lin Yong
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore
| | - Bryan Jian Wei Lim
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Shu Kondo
- Invertebrate Genetics Laboratory, National Institute of Genetics, Shizuoka, Japan
| | - Fengwei Yu
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore, Singapore
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28
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Chew LY, Zhang H, He J, Yu F. The Nrf2-Keap1 pathway is activated by steroid hormone signaling to govern neuronal remodeling. Cell Rep 2021; 36:109466. [PMID: 34348164 DOI: 10.1016/j.celrep.2021.109466] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 06/09/2021] [Accepted: 07/08/2021] [Indexed: 12/30/2022] Open
Abstract
The evolutionarily conserved Nrf2-Keap1 pathway is a key antioxidant response pathway that protects cells/organisms against detrimental effects of oxidative stress. Impaired Nrf2 function is associated with cancer and neurodegenerative diseases in humans. However, the function of the Nrf2-Keap1 pathway in the developing nervous systems has not been established. Here we demonstrate a cell-autonomous role of the Nrf2-Keap1 pathway, composed of CncC/Nrf2, Keap1, and MafS, in governing neuronal remodeling during Drosophila metamorphosis. Nrf2-Keap1 signaling is activated downstream of the steroid hormone ecdysone. Mechanistically, the Nrf2-Keap1 pathway is activated via cytoplasmic-to-nuclear translocation of CncC in an importin- and ecdysone-signaling-dependent manner. Moreover, Nrf2-Keap1 signaling regulates dendrite pruning independent of its canonical antioxidant response pathway, acting instead through proteasomal degradation. This study reveals an epistatic link between the Nrf2-Keap1 pathway and steroid hormone signaling and demonstrates an antioxidant-independent but proteasome-dependent role of the Nrf2-Keap1 pathway in neuronal remodeling.
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Affiliation(s)
- Liang Yuh Chew
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore; Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore
| | - Heng Zhang
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore
| | - Jianzheng He
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore
| | - Fengwei Yu
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore; Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore.
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29
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Furusawa K, Emoto K. Scrap and Build for Functional Neural Circuits: Spatiotemporal Regulation of Dendrite Degeneration and Regeneration in Neural Development and Disease. Front Cell Neurosci 2021; 14:613320. [PMID: 33505249 PMCID: PMC7829185 DOI: 10.3389/fncel.2020.613320] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 12/04/2020] [Indexed: 01/01/2023] Open
Abstract
Dendrites are cellular structures essential for the integration of neuronal information. These elegant but complex structures are highly patterned across the nervous system but vary tremendously in their size and fine architecture, each designed to best serve specific computations within their networks. Recent in vivo imaging studies reveal that the development of mature dendrite arbors in many cases involves extensive remodeling achieved through a precisely orchestrated interplay of growth, degeneration, and regeneration of dendritic branches. Both degeneration and regeneration of dendritic branches involve precise spatiotemporal regulation for the proper wiring of functional networks. In particular, dendrite degeneration must be targeted in a compartmentalized manner to avoid neuronal death. Dysregulation of these developmental processes, in particular dendrite degeneration, is associated with certain types of pathology, injury, and aging. In this article, we review recent progress in our understanding of dendrite degeneration and regeneration, focusing on molecular and cellular mechanisms underlying spatiotemporal control of dendrite remodeling in neural development. We further discuss how developmental dendrite degeneration and regeneration are molecularly and functionally related to dendrite remodeling in pathology, disease, and aging.
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Affiliation(s)
- Kotaro Furusawa
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Kazuo Emoto
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
- International Research Center for Neurointelligence (WPI-IRCN), The University of Tokyo, Tokyo, Japan
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30
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Xie Q, Brbic M, Horns F, Kolluru SS, Jones RC, Li J, Reddy AR, Xie A, Kohani S, Li Z, McLaughlin CN, Li T, Xu C, Vacek D, Luginbuhl DJ, Leskovec J, Quake SR, Luo L, Li H. Temporal evolution of single-cell transcriptomes of Drosophila olfactory projection neurons. eLife 2021; 10:e63450. [PMID: 33427646 PMCID: PMC7870145 DOI: 10.7554/elife.63450] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 01/05/2021] [Indexed: 12/18/2022] Open
Abstract
Neurons undergo substantial morphological and functional changes during development to form precise synaptic connections and acquire specific physiological properties. What are the underlying transcriptomic bases? Here, we obtained the single-cell transcriptomes of Drosophila olfactory projection neurons (PNs) at four developmental stages. We decoded the identity of 21 transcriptomic clusters corresponding to 20 PN types and developed methods to match transcriptomic clusters representing the same PN type across development. We discovered that PN transcriptomes reflect unique biological processes unfolding at each stage-neurite growth and pruning during metamorphosis at an early pupal stage; peaked transcriptomic diversity during olfactory circuit assembly at mid-pupal stages; and neuronal signaling in adults. At early developmental stages, PN types with adjacent birth order share similar transcriptomes. Together, our work reveals principles of cellular diversity during brain development and provides a resource for future studies of neural development in PNs and other neuronal types.
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Affiliation(s)
- Qijing Xie
- Department of Biology, Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
- Neurosciences Graduate Program, Stanford UniversityStanfordUnited States
| | - Maria Brbic
- Department of Computer Science, Stanford UniversityStanfordUnited States
| | - Felix Horns
- Department of Bioengineering, Stanford UniversityStanfordUnited States
- Biophysics Graduate Program, Stanford UniversityStanfordUnited States
| | | | - Robert C Jones
- Department of Bioengineering, Stanford UniversityStanfordUnited States
| | - Jiefu Li
- Department of Biology, Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
| | - Anay R Reddy
- Department of Biology, Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
| | - Anthony Xie
- Department of Biology, Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
| | - Sayeh Kohani
- Department of Biology, Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
| | - Zhuoran Li
- Department of Biology, Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
| | - Colleen N McLaughlin
- Department of Biology, Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
| | - Tongchao Li
- Department of Biology, Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
| | - Chuanyun Xu
- Department of Biology, Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
| | - David Vacek
- Department of Biology, Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
| | - David J Luginbuhl
- Department of Biology, Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
| | - Jure Leskovec
- Department of Computer Science, Stanford UniversityStanfordUnited States
| | - Stephen R Quake
- Department of Bioengineering, Stanford UniversityStanfordUnited States
- Department of Applied Physics, Stanford UniversityStanfordUnited States
- Chan Zuckerberg BiohubStanfordUnited States
| | - Liqun Luo
- Department of Biology, Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
| | - Hongjie Li
- Department of Biology, Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
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31
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Furusawa K, Emoto K. Spatiotemporal regulation of developmental neurite pruning: Molecular and cellular insights from Drosophila models. Neurosci Res 2020; 167:54-63. [PMID: 33309868 DOI: 10.1016/j.neures.2020.11.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 11/10/2020] [Accepted: 11/10/2020] [Indexed: 02/02/2023]
Abstract
Developmental neurite pruning is a process by which neurons selectively eliminate unnecessary processes of axons and/or dendrites without cell death, which shapes the mature wiring of nervous systems. In this sense, developmental neurite pruning requires spatiotemporally precise control of local degradation of cellular components including cytoskeletons and membranes. The Drosophila nervous system undergoes large-scale remodeling, including axon/dendrite pruning, during metamorphosis. In addition to this unique phenomenon in the nervous system, powerful genetic tools make the Drosophila nervous system a sophisticated model to investigate spatiotemporal regulation of neural remodeling. This article reviews recent advances to our understanding of the molecular and cellular mechanisms of developmental axon/dendrite pruning, mainly focusing on studies in Drosophila sensory neurons and mushroom body neurons.
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Affiliation(s)
- Kotaro Furusawa
- Department of Biological Sciences, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
| | - Kazuo Emoto
- Department of Biological Sciences, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; International Research Center for Neurointelligence (WPI-IRCN), The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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32
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Rui M, Bu S, Chew LY, Wang Q, Yu F. The membrane protein Raw regulates dendrite pruning via the secretory pathway. Development 2020; 147:dev.191155. [PMID: 32928906 DOI: 10.1242/dev.191155] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 09/08/2020] [Indexed: 10/23/2022]
Abstract
Neuronal pruning is essential for proper wiring of the nervous systems in invertebrates and vertebrates. Drosophila ddaC sensory neurons selectively prune their larval dendrites to sculpt the nervous system during early metamorphosis. However, the molecular mechanisms underlying ddaC dendrite pruning remain elusive. Here, we identify an important and cell-autonomous role of the membrane protein Raw in dendrite pruning of ddaC neurons. Raw appears to regulate dendrite pruning via a novel mechanism, which is independent of JNK signaling. Importantly, we show that Raw promotes endocytosis and downregulation of the conserved L1-type cell-adhesion molecule Neuroglian (Nrg) prior to dendrite pruning. Moreover, Raw is required to modulate the secretory pathway by regulating the integrity of secretory organelles and efficient protein secretion. Mechanistically, Raw facilitates Nrg downregulation and dendrite pruning in part through regulation of the secretory pathway. Thus, this study reveals a JNK-independent role of Raw in regulating the secretory pathway and thereby promoting dendrite pruning.
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Affiliation(s)
- Menglong Rui
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604
| | - Shufeng Bu
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604.,Department of Biological Sciences, National University of Singapore, Singapore 117543
| | - Liang Yuh Chew
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604.,Department of Biological Sciences, National University of Singapore, Singapore 117543
| | - Qiwei Wang
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604.,Department of Biological Sciences, National University of Singapore, Singapore 117543
| | - Fengwei Yu
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604 .,Department of Biological Sciences, National University of Singapore, Singapore 117543.,NUS Graduate School for Integrative Sciences and Engineering, Centre for Life Sciences, Singapore 117456
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33
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Tang Q, Rui M, Bu S, Wang Y, Chew LY, Yu F. A microtubule polymerase is required for microtubule orientation and dendrite pruning in Drosophila. EMBO J 2020; 39:e103549. [PMID: 32267553 DOI: 10.15252/embj.2019103549] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 02/27/2020] [Accepted: 02/28/2020] [Indexed: 01/12/2023] Open
Abstract
Drosophila class IV ddaC neurons selectively prune all larval dendrites to refine the nervous system during metamorphosis. During dendrite pruning, severing of proximal dendrites is preceded by local microtubule (MT) disassembly. Here, we identify an unexpected role of Mini spindles (Msps), a conserved MT polymerase, in governing dendrite pruning. Msps associates with another MT-associated protein TACC, and both stabilize each other in ddaC neurons. Moreover, Msps and TACC are required to orient minus-end-out MTs in dendrites. We further show that the functions of msps in dendritic MT orientation and dendrite pruning are antagonized by the kinesin-13 MT depolymerase Klp10A. Excessive MT depolymerization, which is induced by pharmacological treatment and katanin overexpression, also perturbs dendritic MT orientation and dendrite pruning, phenocopying msps mutants. Thus, we demonstrate that the MT polymerase Msps is required to form dendritic minus-end-out MTs and thereby promotes dendrite pruning in Drosophila sensory neurons.
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Affiliation(s)
- Quan Tang
- Temasek Life Sciences Laboratory, Singapore City, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore City, Singapore
| | - Menglong Rui
- Temasek Life Sciences Laboratory, Singapore City, Singapore
| | - Shufeng Bu
- Temasek Life Sciences Laboratory, Singapore City, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore City, Singapore
| | - Yan Wang
- Temasek Life Sciences Laboratory, Singapore City, Singapore
| | - Liang Yuh Chew
- Temasek Life Sciences Laboratory, Singapore City, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore City, Singapore
| | - Fengwei Yu
- Temasek Life Sciences Laboratory, Singapore City, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore City, Singapore.,NUS Graduate School for Integrative Sciences and Engineering, Centre for Life Sciences, Singapore City, Singapore.,Neuroscience and Behavioral Disorder Program, Duke-NUS Graduate Medical School Singapore, Singapore City, Singapore
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34
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Wolterhoff N, Gigengack U, Rumpf S. PP2A phosphatase is required for dendrite pruning via actin regulation in Drosophila. EMBO Rep 2020; 21:e48870. [PMID: 32207238 PMCID: PMC7202059 DOI: 10.15252/embr.201948870] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 02/27/2020] [Accepted: 03/04/2020] [Indexed: 12/22/2022] Open
Abstract
Large‐scale pruning, the developmentally regulated degeneration of axons or dendrites, is an important specificity mechanism during neuronal circuit formation. The peripheral sensory class IV dendritic arborization (c4da) neurons of Drosophila larvae specifically prune their dendrites at the onset of metamorphosis in an ecdysone‐dependent manner. Dendrite pruning requires local cytoskeleton remodeling, and the actin‐severing enzyme Mical is an important ecdysone target. In a screen for pruning factors, we identified the protein phosphatase 2 A (PP2A). PP2A interacts genetically with the actin‐severing enzymes Mical and cofilin as well as other actin regulators during pruning. Moreover, Drosophila cofilin undergoes a change in localization at the onset of metamorphosis indicative of a change in actin dynamics. This change is abolished both upon loss of Mical and PP2A. We conclude that PP2A regulates actin dynamics during dendrite pruning.
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Affiliation(s)
- Neele Wolterhoff
- Institute for Neurobiology, University of Münster, Münster, Germany
| | - Ulrike Gigengack
- Institute for Neurobiology, University of Münster, Münster, Germany
| | - Sebastian Rumpf
- Institute for Neurobiology, University of Münster, Münster, Germany
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35
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Rui M, Ng KS, Tang Q, Bu S, Yu F. Protein phosphatase PP2A regulates microtubule orientation and dendrite pruning in Drosophila. EMBO Rep 2020; 21:e48843. [PMID: 32187821 DOI: 10.15252/embr.201948843] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 02/20/2020] [Accepted: 03/04/2020] [Indexed: 11/09/2022] Open
Abstract
Pruning that selectively eliminates inappropriate projections is crucial for sculpting neural circuits during development. During Drosophila metamorphosis, ddaC sensory neurons undergo dendrite-specific pruning in response to the steroid hormone ecdysone. However, the understanding of the molecular mechanisms underlying dendrite pruning remains incomplete. Here, we show that protein phosphatase 2A (PP2A) is required for dendrite pruning. The catalytic (Microtubule star/Mts), scaffolding (PP2A-29B), and two regulatory subunits (Widerborst/Wdb and Twins/Tws) play important roles in dendrite pruning. Functional analyses indicate that PP2A, via Wdb, facilitates the expression of Sox14 and Mical prior to dendrite pruning. Furthermore, PP2A, via Tws, governs the minus-end-out orientation of microtubules (MTs) in the dendrites. Moreover, the levels of Klp10A, a MT depolymerase, increase when PP2A is compromised. Attenuation of Klp10A fully rescues the MT orientation defects in mts or pp2a-29b RNAi ddaC neurons, suggesting that PP2A governs dendritic MT orientation by suppressing Klp10A levels and/or function. Taken together, this study sheds light on a novel function of PP2A in regulating dendrite pruning and dendritic MT polarity in sensory neurons.
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Affiliation(s)
- Menglong Rui
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore City, Singapore
| | - Kay Siong Ng
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore City, Singapore
| | - Quan Tang
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore City, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore City, Singapore
| | - Shufeng Bu
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore City, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore City, Singapore
| | - Fengwei Yu
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore City, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore City, Singapore.,NUS Graduate School for Integrative Sciences and Engineering, Centre for Life Sciences, Singapore City, Singapore.,Neuroscience and Behavioral Disorder Program, Duke-NUS Medical School Singapore, Singapore City, Singapore
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36
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Rab11 activation by Ik2 kinase is required for dendrite pruning in Drosophila sensory neurons. PLoS Genet 2020; 16:e1008626. [PMID: 32059017 PMCID: PMC7046344 DOI: 10.1371/journal.pgen.1008626] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 02/27/2020] [Accepted: 01/23/2020] [Indexed: 12/31/2022] Open
Abstract
Neuronal pruning is a commonly observed phenomenon for the developing nervous systems to ensure precise wiring of neural circuits. The function of Ik2 kinase and its downstream mediator, Spindle-F (Spn-F), are essential for dendrite pruning of Drosophila sensory neurons during development. However, little is known about how Ik2/Spn-F signaling is transduced in neurons and ultimately results in dendrite pruning. Our genetic analyses and rescue experiments demonstrated that the small GTPase Rab11, especially the active GTP-bound form, is required for dendrite pruning. We also found that Rab11 shows genetic interactions with spn-F and ik2 on pruning. Live imaging of single neurons and antibody staining reveal normal Ik2 kinase activation in Rab11 mutant neurons, suggesting that Rab11 could have a functional connection downstream of and/or parallel to the Ik2 kinase signaling. Moreover, we provide biochemical evidence that both the Ik2 kinase activity and the formation of Ik2/Spn-F/Rab11 complexes are central to promote Rab11 activation in cells. Together, our studies reveal that a critical role of Ik2/Spn-F signaling in neuronal pruning is to promote Rab11 activation, which is crucial for dendrite pruning in neurons. During metamorphosis in Drosophila, both the central and peripheral nervous systems undergo substantial neuronal remodeling, such as the cell death of most larval neurons and regeneration of adult neurons, while few larval neurons remain alive and prune their branches. Pruning is a self-destruction program, and thus requires to be tightly controlled within single neurons spatially and temporally during development. Recent studies have shown a strong correlation between pruning and human psychiatric disorders, such as schizophrenia and autism. Drosophila sensory neurons that undergo dendrite pruning provide us an opportunity to study the regulatory mechanism of neuronal pruning. Previously, we identified an IKK-related kinase Ik2 that is essential and sufficient for dendrite pruning, and a coiled-coil protein Spindle-F that mediates Ik2-dependent pruning activity in neurons. However, what are the downstream targets of Ik2/Spindle-F signaling in dendrite pruning remains unclear. In this study, we found that the small GTPase Rab11, especially the active GTP-bound form, is required for dendrite pruning in neurons. We further demonstrated that both the Ik2 kinase activity and Ik2/Spindle-F complexes are essential to enhance Rab11 activation in neurons during dendrite pruning.
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Xu T, Jiang X, Denton D, Kumar S. Ecdysone controlled cell and tissue deletion. Cell Death Differ 2020; 27:1-14. [PMID: 31745213 PMCID: PMC7205961 DOI: 10.1038/s41418-019-0456-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 10/31/2019] [Accepted: 11/04/2019] [Indexed: 12/24/2022] Open
Abstract
The removal of superfluous and unwanted cells is a critical part of animal development. In insects the steroid hormone ecdysone, the focus of this review, is an essential regulator of developmental transitions, including molting and metamorphosis. Like other steroid hormones, ecdysone works via nuclear hormone receptors to direct spatial and temporal regulation of gene transcription including genes required for cell death. During insect metamorphosis, pulses of ecdysone orchestrate the deletion of obsolete larval tissues, including the larval salivary glands and the midgut. In this review we discuss the molecular machinery and mechanisms of ecdysone-dependent cell and tissue removal, with a focus on studies in Drosophila and Lepidopteran insects.
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Affiliation(s)
- Tianqi Xu
- Centre for Cancer Biology, University of South Australia and SA Pathology, GPO Box 2471, Adelaide, SA, 5001, Australia
| | - Xin Jiang
- Centre for Cancer Biology, University of South Australia and SA Pathology, GPO Box 2471, Adelaide, SA, 5001, Australia
| | - Donna Denton
- Centre for Cancer Biology, University of South Australia and SA Pathology, GPO Box 2471, Adelaide, SA, 5001, Australia
| | - Sharad Kumar
- Centre for Cancer Biology, University of South Australia and SA Pathology, GPO Box 2471, Adelaide, SA, 5001, Australia.
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38
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Krämer R, Rode S, Rumpf S. Rab11 is required for neurite pruning and developmental membrane protein degradation in Drosophila sensory neurons. Dev Biol 2019; 451:68-78. [DOI: 10.1016/j.ydbio.2019.03.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 03/05/2019] [Accepted: 03/05/2019] [Indexed: 12/11/2022]
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39
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Zhu S, Chen R, Soba P, Jan YN. JNK signaling coordinates with ecdysone signaling to promote pruning of Drosophila sensory neuron dendrites. Development 2019; 146:dev.163592. [PMID: 30936183 DOI: 10.1242/dev.163592] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 03/25/2019] [Indexed: 12/15/2022]
Abstract
Developmental pruning of axons and dendrites is crucial for the formation of precise neuronal connections, but the mechanisms underlying developmental pruning are not fully understood. Here, we have investigated the function of JNK signaling in dendrite pruning using Drosophila class IV dendritic arborization (c4da) neurons as a model. We find that loss of JNK or its canonical downstream effectors Jun or Fos led to dendrite-pruning defects in c4da neurons. Interestingly, our data show that JNK activity in c4da neurons remains constant from larval to pupal stages but the expression of Fos is specifically activated by ecdysone receptor B1 (EcRB1) at early pupal stages, suggesting that ecdysone signaling provides temporal control of the regulation of dendrite pruning by JNK signaling. Thus, our work not only identifies a novel pathway involved in dendrite pruning and a new downstream target of EcRB1 in c4da neurons, but also reveals that JNK and Ecdysone signaling coordinate to promote dendrite pruning.
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Affiliation(s)
- Sijun Zhu
- Department of Neuroscience and Physiology, State University of New York Upstate Medical University, Syracuse, NY 13210, USA .,Department of Physiology, Howard Hughes Medical Institute, University of California San Francisco, San Francisco, CA 20251, USA
| | - Rui Chen
- Department of Neuroscience and Physiology, State University of New York Upstate Medical University, Syracuse, NY 13210, USA
| | - Peter Soba
- Department of Physiology, Howard Hughes Medical Institute, University of California San Francisco, San Francisco, CA 20251, USA.,Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, University of Hamburg, Hamburg, Germany
| | - Yuh-Nung Jan
- Department of Physiology, Howard Hughes Medical Institute, University of California San Francisco, San Francisco, CA 20251, USA
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40
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Wang Y, Rui M, Tang Q, Bu S, Yu F. Patronin governs minus-end-out orientation of dendritic microtubules to promote dendrite pruning in Drosophila. eLife 2019; 8:39964. [PMID: 30920370 PMCID: PMC6438692 DOI: 10.7554/elife.39964] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 03/08/2019] [Indexed: 01/09/2023] Open
Abstract
Class IV ddaC neurons specifically prune larval dendrites without affecting axons during Drosophila metamorphosis. ddaCs distribute the minus ends of microtubules (MTs) to dendrites but the plus ends to axons. However, a requirement of MT minus-end-binding proteins in dendrite-specific pruning remains completely unknown. Here, we identified Patronin, a minus-end-binding protein, for its crucial and dose-sensitive role in ddaC dendrite pruning. The CKK domain is important for Patronin’s function in dendrite pruning. Moreover, we show that both patronin knockdown and overexpression resulted in a drastic decrease of MT minus ends and a concomitant increase of plus-end-out MTs in ddaC dendrites, suggesting that Patronin stabilizes dendritic minus-end-out MTs. Consistently, attenuation of Klp10A MT depolymerase in patronin mutant neurons significantly restored minus-end-out MTs in dendrites and thereby rescued dendrite-pruning defects. Thus, our study demonstrates that Patronin orients minus-end-out MT arrays in dendrites to promote dendrite-specific pruning mainly through antagonizing Klp10A activity. Editorial note: This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that minor issues remain unresolved (see decision letter).
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Affiliation(s)
- Yan Wang
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore.,NUS Graduate School for Integrative Sciences and Engineering, Centre for Life Sciences, National University of Singapore, Singapore, Singapore
| | - Menglong Rui
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore
| | - Quan Tang
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Shufeng Bu
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Fengwei Yu
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore.,NUS Graduate School for Integrative Sciences and Engineering, Centre for Life Sciences, National University of Singapore, Singapore, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore, Singapore.,Neuroscience and Behavioral Disorder Program, Duke-NUS Graduate Medical School, National University of Singapore, Singapore, Singapore
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41
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Functions of Microtubule Disassembly during Neurite Pruning. Trends Cell Biol 2019; 29:291-297. [PMID: 30683460 DOI: 10.1016/j.tcb.2019.01.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 12/27/2018] [Accepted: 01/02/2019] [Indexed: 11/23/2022]
Abstract
Large-scale neurite pruning, the developmentally regulated degeneration of axons or dendrites, is an important specificity mechanism during neuronal circuit formation. Pruning is usually restricted to single neurite branches and can occur by local degeneration or retraction. How this spatial regulation is achieved, and what triggers degeneration locally, are still poorly understood. At the cellular level, pruning involves local cytoskeleton disassembly before branch removal. Recent evidence suggests that microtubule disassembly is the local trigger and that the specific local microtubule organization of axons or dendrites determines where and how neurites degenerate. Based on these data, we propose a general model for spatial pruning regulation by microtubules and discuss how microtubule-associated proteins such as Tau could contribute to these regulatory aspects.
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42
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Alyagor I, Berkun V, Keren-Shaul H, Marmor-Kollet N, David E, Mayseless O, Issman-Zecharya N, Amit I, Schuldiner O. Combining Developmental and Perturbation-Seq Uncovers Transcriptional Modules Orchestrating Neuronal Remodeling. Dev Cell 2019; 47:38-52.e6. [PMID: 30300589 PMCID: PMC6179959 DOI: 10.1016/j.devcel.2018.09.013] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 06/26/2018] [Accepted: 09/10/2018] [Indexed: 02/06/2023]
Abstract
Developmental neuronal remodeling is an evolutionarily conserved mechanism required for precise wiring of nervous systems. Despite its fundamental role in neurodevelopment and proposed contribution to various neuropsychiatric disorders, the underlying mechanisms are largely unknown. Here, we uncover the fine temporal transcriptional landscape of Drosophila mushroom body γ neurons undergoing stereotypical remodeling. Our data reveal rapid and dramatic changes in the transcriptional landscape during development. Focusing on DNA binding proteins, we identify eleven that are required for remodeling. Furthermore, we sequence developing γ neurons perturbed for three key transcription factors required for pruning. We describe a hierarchical network featuring positive and negative feedback loops. Superimposing the perturbation-seq on the developmental expression atlas highlights a framework of transcriptional modules that together drive remodeling. Overall, this study provides a broad and detailed molecular insight into the complex regulatory dynamics of developmental remodeling and thus offers a pipeline to dissect developmental processes via RNA profiling.
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Affiliation(s)
- Idan Alyagor
- Department of Molecular Cell Biology, Weizmann Institute of Sciences, Rehovot, Israel
| | - Victoria Berkun
- Department of Molecular Cell Biology, Weizmann Institute of Sciences, Rehovot, Israel
| | - Hadas Keren-Shaul
- Department of Immunology, Weizmann Institute of Sciences, Rehovot, Israel; Life Science Core Facility, Weizmann Institute of Sciences, Rehovot, Israel
| | - Neta Marmor-Kollet
- Department of Molecular Cell Biology, Weizmann Institute of Sciences, Rehovot, Israel
| | - Eyal David
- Department of Immunology, Weizmann Institute of Sciences, Rehovot, Israel
| | - Oded Mayseless
- Department of Molecular Cell Biology, Weizmann Institute of Sciences, Rehovot, Israel
| | - Noa Issman-Zecharya
- Department of Molecular Cell Biology, Weizmann Institute of Sciences, Rehovot, Israel
| | - Ido Amit
- Department of Immunology, Weizmann Institute of Sciences, Rehovot, Israel
| | - Oren Schuldiner
- Department of Molecular Cell Biology, Weizmann Institute of Sciences, Rehovot, Israel.
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43
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Yoong LF, Pai YJ, Moore AW. Stages and transitions in dendrite arbor differentiation. Neurosci Res 2019; 138:70-78. [DOI: 10.1016/j.neures.2018.09.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 08/10/2018] [Accepted: 08/14/2018] [Indexed: 12/26/2022]
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44
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Zong W, Wang Y, Tang Q, Zhang H, Yu F. Prd1 associates with the clathrin adaptor α-Adaptin and the kinesin-3 Imac/Unc-104 to govern dendrite pruning in Drosophila. PLoS Biol 2018; 16:e2004506. [PMID: 30142146 PMCID: PMC6126864 DOI: 10.1371/journal.pbio.2004506] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 09/06/2018] [Accepted: 08/03/2018] [Indexed: 11/18/2022] Open
Abstract
Refinement of the nervous system depends on selective removal of excessive axons/dendrites, a process known as pruning. Drosophila ddaC sensory neurons prune their larval dendrites via endo-lysosomal degradation of the L1-type cell adhesion molecule (L1-CAM), Neuroglian (Nrg). Here, we have identified a novel gene, pruning defect 1 (prd1), which governs dendrite pruning of ddaC neurons. We show that Prd1 colocalizes with the clathrin adaptor protein α-Adaptin (α-Ada) and the kinesin-3 immaculate connections (Imac)/Uncoordinated-104 (Unc-104) in dendrites. Moreover, Prd1 physically associates with α-Ada and Imac, which are both critical for dendrite pruning. Prd1, α-Ada, and Imac promote dendrite pruning via the regulation of endo-lysosomal degradation of Nrg. Importantly, genetic interactions among prd1, α-adaptin, and imac indicate that they act in the same pathway to promote dendrite pruning. Our findings indicate that Prd1, α-Ada, and Imac act together to regulate discrete distribution of α-Ada/clathrin puncta, facilitate endo-lysosomal degradation, and thereby promote dendrite pruning in sensory neurons. During the maturation of the nervous system, some neurons can selectively eliminate their unnecessary connections, including dendrites and axons, to retain specific connections. In Drosophila, a class of sensory neurons lose all their larval dendrites during metamorphosis, when they transition from larvae to adults. We previously showed that these neurons prune their dendrites via lysosome-mediated degradation of a cell-adhesion protein, Neuroglian. In this paper, we identified a previously uncharacterized gene, pruning defect 1 (prd1), which plays an important role in dendrite pruning. We show that Prd1 is localized and complexed with α-Adaptin and Imac, two other proteins that are also essential for dendrite pruning. Moreover, Prd1, α-Adaptin, and Imac act in a common pathway to promote dendrite pruning by down-regulating Neuroglian protein. Thus, our study highlights a mechanism whereby Prd1, α-Adaptin, and Imac act together to regulate distribution of α-Adaptin/clathrin puncta, facilitate lysosome-dependent protein degradation, and thereby promote dendrite pruning in Drosophila sensory neurons.
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Affiliation(s)
- Wenhui Zong
- Temasek Life Sciences Laboratory and Department of Biological Sciences, 1 Research Link, National University of Singapore, Singapore
| | - Yan Wang
- Temasek Life Sciences Laboratory and Department of Biological Sciences, 1 Research Link, National University of Singapore, Singapore
| | - Quan Tang
- Temasek Life Sciences Laboratory and Department of Biological Sciences, 1 Research Link, National University of Singapore, Singapore
| | - Heng Zhang
- Temasek Life Sciences Laboratory and Department of Biological Sciences, 1 Research Link, National University of Singapore, Singapore
| | - Fengwei Yu
- Temasek Life Sciences Laboratory and Department of Biological Sciences, 1 Research Link, National University of Singapore, Singapore
- NUS Graduate School for Integrative Sciences and Engineering, Centre for Life Sciences, Singapore
- Neuroscience and Behavioral Disorder Program, Duke-NUS Graduate Medical School Singapore, Singapore
- * E-mail:
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45
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Differential Requirement for Translation Initiation Factor Pathways during Ecdysone-Dependent Neuronal Remodeling in Drosophila. Cell Rep 2018; 24:2287-2299.e4. [DOI: 10.1016/j.celrep.2018.07.074] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 06/22/2018] [Accepted: 07/23/2018] [Indexed: 11/23/2022] Open
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46
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Liou NF, Lin SH, Chen YJ, Tsai KT, Yang CJ, Lin TY, Wu TH, Lin HJ, Chen YT, Gohl DM, Silies M, Chou YH. Diverse populations of local interneurons integrate into the Drosophila adult olfactory circuit. Nat Commun 2018; 9:2232. [PMID: 29884811 PMCID: PMC5993751 DOI: 10.1038/s41467-018-04675-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 05/14/2018] [Indexed: 11/09/2022] Open
Abstract
Drosophila olfactory local interneurons (LNs) in the antennal lobe are highly diverse and variable. How and when distinct types of LNs emerge, differentiate, and integrate into the olfactory circuit is unknown. Through systematic developmental analyses, we found that LNs are recruited to the adult olfactory circuit in three groups. Group 1 LNs are residual larval LNs. Group 2 are adult-specific LNs that emerge before cognate sensory and projection neurons establish synaptic specificity, and Group 3 LNs emerge after synaptic specificity is established. Group 1 larval LNs are selectively reintegrated into the adult circuit through pruning and re-extension of processes to distinct regions of the antennal lobe, while others die during metamorphosis. Precise temporal control of this pruning and cell death shapes the global organization of the adult antennal lobe. Our findings provide a road map to understand how LNs develop and contribute to constructing the olfactory circuit. Local interneurons (LNs) in the Drosophila olfactory system are highly diverse. Here, the authors labeled different LN types and described how different LN subtypes are integrated into the developing circuit.
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Affiliation(s)
- Nan-Fu Liou
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, 11529, Taiwan
| | - Shih-Han Lin
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, 11529, Taiwan
| | - Ying-Jun Chen
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, 11529, Taiwan
| | - Kuo-Ting Tsai
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, 11529, Taiwan
| | - Chi-Jen Yang
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, 11529, Taiwan
| | - Tzi-Yang Lin
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, 11529, Taiwan.,Research Institute of Molecular Pathology (IMP), Vienna Biocenter, Campus-Vienna-Biocenter 1, 1030, Vienna, Austria
| | - Ting-Han Wu
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, 11529, Taiwan
| | - Hsin-Ju Lin
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, 11529, Taiwan
| | - Yuh-Tarng Chen
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, 11529, Taiwan
| | - Daryl M Gohl
- Department of Neurobiology, Stanford University, Stanford, CA, 94305, USA.,University of Minnesota Genomics Center, 1-210 CCRB, 2231 6th Street SE, Minneapolis, MN, 55455, USA
| | - Marion Silies
- Department of Neurobiology, Stanford University, Stanford, CA, 94305, USA.,European Neuroscience Institute, University Medical Center Göttingen, Grisebachstr. 5, 37077, Göttingen, Germany
| | - Ya-Hui Chou
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, 11529, Taiwan. .,Neuroscience Program of Academia Sinica, Academia Sinica, Taipei, 11529, Taiwan.
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47
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Abstract
Alto and Terman introduce the MICAL family of actin regulatory redox enzymes.
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Affiliation(s)
- Laura Taylor Alto
- Departments of Neuroscience and Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jonathan R Terman
- Departments of Neuroscience and Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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48
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Wu H, Yesilyurt HG, Yoon J, Terman JR. The MICALs are a Family of F-actin Dismantling Oxidoreductases Conserved from Drosophila to Humans. Sci Rep 2018; 8:937. [PMID: 29343822 PMCID: PMC5772675 DOI: 10.1038/s41598-017-17943-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 11/30/2017] [Indexed: 12/27/2022] Open
Abstract
Cellular form and function – and thus normal development and physiology – are specified via proteins that control the organization and dynamic properties of the actin cytoskeleton. Using the Drosophila model, we have recently identified an unusual actin regulatory enzyme, Mical, which is directly activated by F-actin to selectively post-translationally oxidize and destabilize filaments – regulating numerous cellular behaviors. Mical proteins are also present in mammals, but their actin regulatory properties, including comparisons among different family members, remain poorly defined. We now find that each human MICAL family member, MICAL-1, MICAL-2, and MICAL-3, directly induces F-actin dismantling and controls F-actin-mediated cellular remodeling. Specifically, each human MICAL selectively associates with F-actin, which directly induces MICALs catalytic activity. We also find that each human MICAL uses an NADPH-dependent Redox activity to post-translationally oxidize actin’s methionine (M) M44/M47 residues, directly dismantling filaments and limiting new polymerization. Genetic experiments also demonstrate that each human MICAL drives F-actin disassembly in vivo, reshaping cells and their membranous extensions. Our results go on to reveal that MsrB/SelR reductase enzymes counteract each MICAL’s effect on F-actin in vitro and in vivo. Collectively, our results therefore define the MICALs as an important phylogenetically-conserved family of catalytically-acting F-actin disassembly factors.
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Affiliation(s)
- Heng Wu
- Departments of Neuroscience and Pharmacology, Harold C Simmons Comprehensive Cancer Center, The University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Hunkar Gizem Yesilyurt
- Departments of Neuroscience and Pharmacology, Harold C Simmons Comprehensive Cancer Center, The University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Jimok Yoon
- Departments of Neuroscience and Pharmacology, Harold C Simmons Comprehensive Cancer Center, The University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.,Drug Development Center, SK biopharmaceuticals Co. Ltd., Seongnam, 13494, Korea
| | - Jonathan R Terman
- Departments of Neuroscience and Pharmacology, Harold C Simmons Comprehensive Cancer Center, The University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
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49
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Chen D, Dale RK, Lei EP. Shep regulates Drosophila neuronal remodeling by controlling transcription of its chromatin targets. Development 2018; 145:dev.154047. [PMID: 29158441 DOI: 10.1242/dev.154047] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 11/07/2017] [Indexed: 11/20/2022]
Abstract
Neuronal remodeling is crucial for formation of the mature nervous system and disruption of this process can lead to neuropsychiatric diseases. Global gene expression changes in neurons during remodeling as well as the factors that regulate these changes remain poorly defined. To elucidate this process, we performed RNA-seq on isolated Drosophila larval and pupal neurons and found upregulated synaptic signaling and downregulated gene expression regulators as a result of normal neuronal metamorphosis. We further tested the role of alan shepard (shep), which encodes an evolutionarily conserved RNA-binding protein required for proper neuronal remodeling. Depletion of shep in neurons prevents the execution of metamorphic gene expression patterns, and shep-regulated genes correspond to Shep chromatin and/or RNA-binding targets. Reduced expression of a Shep-inhibited target gene that we identified, brat, is sufficient to rescue neuronal remodeling defects of shep knockdown flies. Our results reveal direct regulation of transcriptional programs by Shep to regulate neuronal remodeling during metamorphosis.
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Affiliation(s)
- Dahong Chen
- Nuclear Organization and Gene Expression Section, Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ryan K Dale
- Nuclear Organization and Gene Expression Section, Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Elissa P Lei
- Nuclear Organization and Gene Expression Section, Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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50
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Wang Q, Wang Y, Yu F. Yif1 associates with Yip1 on Golgi and regulates dendrite pruning in sensory neurons during Drosophila metamorphosis. Development 2018; 145:dev.164475. [DOI: 10.1242/dev.164475] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 05/09/2018] [Indexed: 01/21/2023]
Abstract
Pruning that selectively removes unnecessary neurites without causing neuronal death is essential for sculpting the mature nervous system during development. In Drosophila, ddaC sensory neurons specifically prune their larval dendrites with intact axons during metamorphosis. However, it remains unknown about an important role of ER-to-Golgi transport in dendrite pruning. Here, in a clonal screen we identified Yif1, an uncharacterized Drosophila homologue of Yif1p that is known as a regulator of ER-to-Golgi transport in yeast. We show that Yif1 is required for dendrite pruning of ddaC neurons but not for apoptosis of ddaF neurons. We further identified the Yif1-binding partner Yip1 which is also crucial for dendrite pruning. Yif1 forms a protein complex with Yip1 in S2 cells and ddaC neurons. Yip1 and Yif1 colocalize on ER/Golgi and are required for the integrity of Golgi apparatus and outposts. Moreover, we show that two GTPases Rab1 and Sar1, known to regulate ER-to-Golgi transport, are essential for dendrite pruning of ddaC neurons. Finally, our data reveal that ER-to-Golgi transport promotes endocytosis and downregulation of cell adhesion molecule Neuroglian and thereby dendrite pruning.
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Affiliation(s)
- Qiwei Wang
- Temasek Life Sciences Laboratory and Department of Biological Sciences, 1 Research Link, National University of Singapore, Singapore 117604
| | - Yan Wang
- Temasek Life Sciences Laboratory and Department of Biological Sciences, 1 Research Link, National University of Singapore, Singapore 117604
- NUS Graduate School for Integrative Sciences and Engineering, Centre for Life Sciences, Singapore 117456
| | - Fengwei Yu
- Temasek Life Sciences Laboratory and Department of Biological Sciences, 1 Research Link, National University of Singapore, Singapore 117604
- NUS Graduate School for Integrative Sciences and Engineering, Centre for Life Sciences, Singapore 117456
- Neuroscience and Behavioral Disorder Program, Duke-NUS Graduate Medical School Singapore, 8 College Road, Singapore 169857
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