1
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Sung HH, Li H, Huang YC, Ai CL, Hsieh MY, Jan HM, Peng YJ, Lin HY, Yeh CH, Lin SY, Yeh CY, Cheng YJ, Khoo KH, Lin CH, Chien CT. Galectins induced from hemocytes bridge phosphatidylserine and N-glycosylated Drpr/CED-1 receptor during dendrite pruning. Nat Commun 2024; 15:7402. [PMID: 39191750 DOI: 10.1038/s41467-024-51581-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 08/12/2024] [Indexed: 08/29/2024] Open
Abstract
During neuronal pruning, phagocytes engulf shed cellular debris to avoid inflammation and maintain tissue homeostasis. How phagocytic receptors recognize degenerating neurites had been unclear. Here, we identify two glucosyltransferases Alg8 and Alg10 of the N-glycosylation pathway required for dendrite fragmentation and clearance through genetic screen. The scavenger receptor Draper (Drpr) is N-glycosylated with complex- or hybrid-type N-glycans that interact specifically with galectins. We also identify the galectins Crouching tiger (Ctg) and Hidden dragon (Hdg) that interact with N-glycosylated Drpr and function in dendrite pruning via the Drpr pathway. Ctg and Hdg are required in hemocytes for expression and function, and are induced during dendrite injury to localize to injured dendrites through specific interaction with exposed phosphatidylserine (PS) on the surface membrane of injured dendrites. Thus, the galectins Ctg and Hdg bridge the interaction between PS and N-glycosylated Drpr, leading to the activation of phagocytosis.
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Affiliation(s)
- Hsin-Ho Sung
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Hsun Li
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Yi-Chun Huang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Chun-Lu Ai
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Ming-Yen Hsieh
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Hau-Ming Jan
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Yu-Ju Peng
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Hsien-Ya Lin
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Chih-Hsuan Yeh
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Shu-Yu Lin
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Chun-Yen Yeh
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Ying-Ju Cheng
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Kay-Hooi Khoo
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Chun-Hung Lin
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Cheng-Ting Chien
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.
- Neuroscience Program of Academia Sinica, Academia Sinica, Taipei, Taiwan.
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2
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Dingwall CB, Sasaki Y, Strickland A, Summers DW, Bloom AJ, DiAntonio A, Milbrandt J. Suppressing phagocyte activation by overexpressing the phosphatidylserine lipase ABHD12 preserves sarmopathic nerves. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.20.599919. [PMID: 38979309 PMCID: PMC11230269 DOI: 10.1101/2024.06.20.599919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Programmed axon degeneration (AxD) is a key feature of many neurodegenerative diseases. In healthy axons, the axon survival factor NMNAT2 inhibits SARM1, the central executioner of AxD, preventing it from initiating the rapid local NAD+ depletion and metabolic catastrophe that precipitates axon destruction. Because these components of the AxD pathway act within neurons, it was also assumed that the timetable of AxD was set strictly by a cell-intrinsic mechanism independent of neuron-extrinsic processes later activated by axon fragmentation. However, using a rare human disease model of neuropathy caused by hypomorphic NMNAT2 mutations and chronic SARM1 activation (sarmopathy), we demonstrated that neuronal SARM1 can initiate macrophage-mediated axon elimination long before stressed-but-viable axons would otherwise succumb to cell-intrinsic metabolic failure. Investigating potential SARM1-dependent signals that mediate macrophage recognition and/or engulfment of stressed-but-viable axons, we found that chronic SARM1 activation triggers axonal blebbing and dysregulation of phosphatidylserine (PS), a potent phagocyte immunomodulatory molecule. Neuronal expression of the phosphatidylserine lipase ABDH12 suppresses nerve macrophage activation, preserves motor axon integrity, and rescues motor function in this chronic sarmopathy model. We conclude that PS dysregulation is an early SARM1-dependent axonal stress signal, and that blockade of phagocytic recognition and engulfment of stressed-but-viable axons could be an attractive therapeutic target for management of neurological disorders involving SARM1 activation.
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3
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Perry N, Braun R, Ben‐Hamo‐Arad A, Kanaan D, Arad T, Porat‐Kuperstein L, Toledano H. Integrin restriction by miR-34 protects germline progenitors from cell death during aging. Aging Cell 2024; 23:e14131. [PMID: 38450871 PMCID: PMC11166360 DOI: 10.1111/acel.14131] [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: 09/18/2023] [Revised: 02/07/2024] [Accepted: 02/11/2024] [Indexed: 03/08/2024] Open
Abstract
During aging, regenerative tissues must dynamically balance the two opposing processes of proliferation and cell death. While many microRNAs are differentially expressed during aging, their roles as dynamic regulators of tissue regeneration have yet to be described. We show that in the highly regenerative Drosophila testis, miR-34 levels are significantly elevated during aging. miR-34 modulates germ cell death and protects the progenitor germ cells from accelerated aging. However, miR-34 is not expressed in the progenitors themselves but rather in neighboring cyst cells that kill the progenitors. Transcriptomics followed by functional analysis revealed that during aging, miR-34 modifies integrin signaling by limiting the levels of the heterodimeric integrin receptor αPS2 and βPS subunits. In addition, we found that in cyst cells, this heterodimer is essential for inducing phagoptosis and degradation of the progenitor germ cells. Together, these data suggest that the miR-34-integrin signaling axis acts as a sensor of progenitor germ cell death to extend progenitor functionality during aging.
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Affiliation(s)
- Noam Perry
- Department of Human Biology, Faculty of Natural SciencesUniversity of HaifaHaifaIsrael
| | - Racheli Braun
- Department of Human Biology, Faculty of Natural SciencesUniversity of HaifaHaifaIsrael
- Biomedical Engineering FacultyTechnion IITsHaifaIsrael
| | - Aya Ben‐Hamo‐Arad
- Department of Human Biology, Faculty of Natural SciencesUniversity of HaifaHaifaIsrael
| | - Diana Kanaan
- Department of Human Biology, Faculty of Natural SciencesUniversity of HaifaHaifaIsrael
| | - Tal Arad
- Department of Human Biology, Faculty of Natural SciencesUniversity of HaifaHaifaIsrael
| | | | - Hila Toledano
- Department of Human Biology, Faculty of Natural SciencesUniversity of HaifaHaifaIsrael
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4
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Davis GH, Zaya A, Pearce MMP. Impairment of the Glial Phagolysosomal System Drives Prion-Like Propagation in a Drosophila Model of Huntington's Disease. J Neurosci 2024; 44:e1256232024. [PMID: 38589228 PMCID: PMC11097281 DOI: 10.1523/jneurosci.1256-23.2024] [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: 07/06/2023] [Revised: 01/31/2024] [Accepted: 02/26/2024] [Indexed: 04/10/2024] Open
Abstract
Protein misfolding, aggregation, and spread through the brain are primary drivers of neurodegenerative disease pathogenesis. Phagocytic glia are responsible for regulating the load of pathological proteins in the brain, but emerging evidence suggests that glia may also act as vectors for aggregate spread. Accumulation of protein aggregates could compromise the ability of glia to eliminate toxic materials from the brain by disrupting efficient degradation in the phagolysosomal system. A better understanding of phagocytic glial cell deficiencies in the disease state could help to identify novel therapeutic targets for multiple neurological disorders. Here, we report that mutant huntingtin (mHTT) aggregates impair glial responsiveness to injury and capacity to degrade neuronal debris in male and female adult Drosophila expressing the gene that causes Huntington's disease (HD). mHTT aggregate formation in neurons impairs engulfment and clearance of injured axons and causes accumulation of phagolysosomes in glia. Neuronal mHTT expression induces upregulation of key innate immunity and phagocytic genes, some of which were found to regulate mHTT aggregate burden in the brain. A forward genetic screen revealed Rab10 as a novel component of Draper-dependent phagocytosis that regulates mHTT aggregate transmission from neurons to glia. These data suggest that glial phagocytic defects enable engulfed mHTT aggregates to evade lysosomal degradation and acquire prion-like characteristics. Together, our findings uncover new mechanisms that enhance our understanding of the beneficial and harmful effects of phagocytic glia in HD and other neurodegenerative diseases.
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Affiliation(s)
- Graham H Davis
- Department of Biological and Biomedical Sciences, Rowan University, Glassboro, New Jersey 08028
- Department of Biology, Saint Joseph's University, Philadelphia, Pennsylvania 19131
- Department of Biological Sciences, University of the Sciences, Philadelphia, Pennsylvania 19104
| | - Aprem Zaya
- Department of Biological Sciences, University of the Sciences, Philadelphia, Pennsylvania 19104
| | - Margaret M Panning Pearce
- Department of Biological and Biomedical Sciences, Rowan University, Glassboro, New Jersey 08028
- Department of Biology, Saint Joseph's University, Philadelphia, Pennsylvania 19131
- Department of Biological Sciences, University of the Sciences, Philadelphia, Pennsylvania 19104
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5
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Nelson N, Vita DJ, Broadie K. Experience-dependent glial pruning of synaptic glomeruli during the critical period. Sci Rep 2024; 14:9110. [PMID: 38643298 PMCID: PMC11032375 DOI: 10.1038/s41598-024-59942-3] [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: 02/14/2024] [Accepted: 04/16/2024] [Indexed: 04/22/2024] Open
Abstract
Critical periods are temporally-restricted, early-life windows when sensory experience remodels synaptic connectivity to optimize environmental input. In the Drosophila juvenile brain, critical period experience drives synapse elimination, which is transiently reversible. Within olfactory sensory neuron (OSN) classes synapsing onto single projection neurons extending to brain learning/memory centers, we find glia mediate experience-dependent pruning of OSN synaptic glomeruli downstream of critical period odorant exposure. We find glial projections infiltrate brain neuropil in response to critical period experience, and use Draper (MEGF10) engulfment receptors to prune synaptic glomeruli. Downstream, we find antagonistic Basket (JNK) and Puckered (DUSP) signaling is required for the experience-dependent translocation of activated Basket into glial nuclei. Dependent on this signaling, we find critical period experience drives expression of the F-actin linking signaling scaffold Cheerio (FLNA), which is absolutely essential for the synaptic glomeruli pruning. We find Cheerio mediates experience-dependent regulation of the glial F-actin cytoskeleton for critical period remodeling. These results define a sequential pathway for experience-dependent brain synaptic glomeruli pruning in a strictly-defined critical period; input experience drives neuropil infiltration of glial projections, Draper/MEGF10 receptors activate a Basket/JNK signaling cascade for transcriptional activation, and Cheerio/FLNA induction regulates the glial actin cytoskeleton to mediate targeted synapse phagocytosis.
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Affiliation(s)
- Nichalas Nelson
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN, 37235, USA
| | - Dominic J Vita
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN, 37235, USA
| | - Kendal Broadie
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN, 37235, USA.
- Department of Cell and Developmental Biology, Vanderbilt University and Medical Center, Nashville, TN, 37235, USA.
- Kennedy Center for Research on Human Development, Vanderbilt University and Medical Center, Nashville, TN, 37235, USA.
- Vanderbilt Brain Institute, Vanderbilt University and Medical Center, Nashville, TN, 37235, USA.
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6
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Rommelaere S, Carboni A, Bada Juarez JF, Boquete JP, Abriata LA, Teixeira Pinto Meireles F, Rukes V, Vincent C, Kondo S, Dionne MS, Dal Peraro M, Cao C, Lemaitre B. A humoral stress response protects Drosophila tissues from antimicrobial peptides. Curr Biol 2024; 34:1426-1437.e6. [PMID: 38484734 DOI: 10.1016/j.cub.2024.02.049] [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: 08/15/2023] [Revised: 12/18/2023] [Accepted: 02/21/2024] [Indexed: 04/11/2024]
Abstract
7An efficient immune system must provide protection against a broad range of pathogens without causing excessive collateral tissue damage. While immune effectors have been well characterized, we know less about the resilience mechanisms protecting the host from its own immune response. Antimicrobial peptides (AMPs) are small, cationic peptides that contribute to innate defenses by targeting negatively charged membranes of microbes. While protective against pathogens, AMPs can be cytotoxic to host cells. Here, we reveal that a family of stress-induced proteins, the Turandots, protect the Drosophila respiratory system from AMPs, increasing resilience to stress. Flies lacking Turandot genes are susceptible to environmental stresses due to AMP-induced tracheal apoptosis. Turandot proteins bind to host cell membranes and mask negatively charged phospholipids, protecting them from cationic pore-forming AMPs. Collectively, these data demonstrate that Turandot stress proteins mitigate AMP cytotoxicity to host tissues and therefore improve their efficacy.
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Affiliation(s)
- Samuel Rommelaere
- Global Health Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.
| | - Alexia Carboni
- Global Health Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Juan F Bada Juarez
- Institute of Bioengineering, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Jean-Philippe Boquete
- Global Health Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Luciano A Abriata
- Institute of Bioengineering, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Fernando Teixeira Pinto Meireles
- Institute of Bioengineering, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Verena Rukes
- Institute of Bioengineering, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Crystal Vincent
- Department of Biochemistry, School of Biological and Behavioural Sciences, Queen Mary University of London, E1 4NS London, UK
| | - Shu Kondo
- Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science, 162-8601 Tokyo, Japan
| | - Marc S Dionne
- Centre for Bacterial Resistance Biology and Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Matteo Dal Peraro
- Institute of Bioengineering, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Chan Cao
- Department of Inorganic and Analytical Chemistry, Chemistry and Biochemistry, University of Geneva, 1211 Geneva, Switzerland
| | - Bruno Lemaitre
- Global Health Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.
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7
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Norris AC, Mansueto AJ, Jimenez M, Yazlovitskaya EM, Jain BK, Graham TR. Flipping the script: Advances in understanding how and why P4-ATPases flip lipid across membranes. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119700. [PMID: 38382846 DOI: 10.1016/j.bbamcr.2024.119700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 11/15/2023] [Accepted: 02/16/2024] [Indexed: 02/23/2024]
Abstract
Type IV P-type ATPases (P4-ATPases) are a family of transmembrane enzymes that translocate lipid substrates from the outer to the inner leaflet of biological membranes and thus create an asymmetrical distribution of lipids within membranes. On the cellular level, this asymmetry is essential for maintaining the integrity and functionality of biological membranes, creating platforms for signaling events and facilitating vesicular trafficking. On the organismal level, this asymmetry has been shown to be important in maintaining blood homeostasis, liver metabolism, neural development, and the immune response. Indeed, dysregulation of P4-ATPases has been linked to several diseases; including anemia, cholestasis, neurological disease, and several cancers. This review will discuss the evolutionary transition of P4-ATPases from cation pumps to lipid flippases, the new lipid substrates that have been discovered, the significant advances that have been achieved in recent years regarding the structural mechanisms underlying the recognition and flipping of specific lipids across biological membranes, and the consequences of P4-ATPase dysfunction on cellular and physiological functions. Additionally, we emphasize the requirement for additional research to comprehensively understand the involvement of flippases in cellular physiology and disease and to explore their potential as targets for therapeutics in treating a variety of illnesses. The discussion in this review will primarily focus on the budding yeast, C. elegans, and mammalian P4-ATPases.
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Affiliation(s)
- Adriana C Norris
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
| | | | - Mariana Jimenez
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
| | | | - Bhawik K Jain
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
| | - Todd R Graham
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA.
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8
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You W, Knoops K, Boesten I, Berendschot TTJM, van Zandvoort MAMJ, Benedikter BJ, Webers CAB, Reutelingsperger CPM, Gorgels TGMF. A time window for rescuing dying retinal ganglion cells. Cell Commun Signal 2024; 22:88. [PMID: 38297331 PMCID: PMC10832163 DOI: 10.1186/s12964-023-01427-3] [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: 09/18/2023] [Accepted: 12/08/2023] [Indexed: 02/02/2024] Open
Abstract
BACKGROUND Retinal ganglion cell (RGC) degeneration and death cause vision loss in patients with glaucoma. Regulated cell death, once initiated, is generally considered to be an irreversible process. Recently, we showed that, by timely removing the cell death stimulus, stressed neuronal PC12 cells can recover from phosphatidylserine (PS) exposure, nuclear shrinkage, DNA damage, mitochondrial fragmentation, mitochondrial membrane potential loss, and retraction of neurites, all hallmarks of an activated cell death program. Whether the cell death process can be reversed in neurons of the central nervous system, like RGCs, is still unknown. Here, we studied reversibility of the activated cell death program in primary rat RGCs (prRGCs). METHODS prRGCs were exposed to ethanol (5%, vol/vol) to induce cell death. At different stages of the cell death process, ethanol was removed by washing and injured prRGCs were further cultured in fresh medium to see whether they recovered. The dynamics of single cells were monitored by high-resolution live-cell spinning disk microscopy. PS exposure, mitochondrial structure, membrane potential, and intracellular Ca2+ were revealed by annexin A5-FITC, Mito-tracker, TMRM, and Fluo 8-AM staining, respectively. The distribution of cytochrome c was investigated by immunofluorescence. The ultrastructure of mitochondria was studied by electron microscopy. RESULTS Analysis of temporal relationships between mitochondrial changes and PS exposure showed that fragmentation of the mitochondrial network and loss of mitochondrial membrane potential occurred before PS exposure. Mitochondrial changes proceeded caspase-independently, while PS exposure was caspase dependent. Interestingly, prRGCs recovered quickly from these mitochondrial changes but not from PS exposure at the plasma membrane. Correlative light and electron microscopy showed that stress-induced decrease in mitochondrial area, length and cristae number was reversible. Intracellular Ca2+ was elevated during this stage of reversible mitochondrial injury, but there was no sign of mitochondrial cytochrome c release. CONCLUSIONS Our study demonstrates that RGCs with impaired mitochondrial structure and function can fully recover if there is no mitochondrial cytochrome c release yet, and no PS is exposed at the plasma membrane. This finding indicates that there is a time window for rescuing dying or injured RGCs, by simply removing the cell death stimulus. Video Abstract.
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Affiliation(s)
- Wenting You
- University Eye Clinic Maastricht UMC+, Maastricht University Medical Center+, Maastricht, 6229 HX, The Netherlands
- Department of Biochemistry, CARIM School for Cardiovascular Disease, Maastricht University, Maastricht, 6229 ER, The Netherlands
- Department of Mental Health and Neuroscience, Maastricht University, Maastricht, 6229 ER, The Netherlands
| | - Kèvin Knoops
- The Microscopy CORE lab, Maastricht Multimodal Molecular Imaging Institute, Maastricht University, Maastricht, 6229 ER, The Netherlands
| | - Iris Boesten
- University Eye Clinic Maastricht UMC+, Maastricht University Medical Center+, Maastricht, 6229 HX, The Netherlands
| | - Tos T J M Berendschot
- University Eye Clinic Maastricht UMC+, Maastricht University Medical Center+, Maastricht, 6229 HX, The Netherlands
| | - Marc A M J van Zandvoort
- Department of Molecular Cell Biology, CARIM School for Cardiovascular Disease, Maastricht University, Maastricht, 6229 ER, The Netherlands
- Institute of Molecular Cardiovascular Research (IMCAR), Universitätsklinikum Aachen, 52074, Aachen, Germany
| | - Birke J Benedikter
- University Eye Clinic Maastricht UMC+, Maastricht University Medical Center+, Maastricht, 6229 HX, The Netherlands
| | - Carroll A B Webers
- University Eye Clinic Maastricht UMC+, Maastricht University Medical Center+, Maastricht, 6229 HX, The Netherlands
| | - Chris P M Reutelingsperger
- Department of Biochemistry, CARIM School for Cardiovascular Disease, Maastricht University, Maastricht, 6229 ER, The Netherlands.
| | - Theo G M F Gorgels
- University Eye Clinic Maastricht UMC+, Maastricht University Medical Center+, Maastricht, 6229 HX, The Netherlands.
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9
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Huang Z. Evidence that Alzheimer's Disease Is a Disease of Competitive Synaptic Plasticity Gone Awry. J Alzheimers Dis 2024; 99:447-470. [PMID: 38669548 PMCID: PMC11119021 DOI: 10.3233/jad-240042] [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] [Indexed: 04/28/2024]
Abstract
Mounting evidence indicates that a physiological function of amyloid-β (Aβ) is to mediate neural activity-dependent homeostatic and competitive synaptic plasticity in the brain. I have previously summarized the lines of evidence supporting this hypothesis and highlighted the similarities between Aβ and anti-microbial peptides in mediating cell/synapse competition. In cell competition, anti-microbial peptides deploy a multitude of mechanisms to ensure both self-protection and competitor elimination. Here I review recent studies showing that similar mechanisms are at play in Aβ-mediated synapse competition and perturbations in these mechanisms underpin Alzheimer's disease (AD). Specifically, I discuss evidence that Aβ and ApoE, two crucial players in AD, co-operate in the regulation of synapse competition. Glial ApoE promotes self-protection by increasing the production of trophic monomeric Aβ and inhibiting its assembly into toxic oligomers. Conversely, Aβ oligomers, once assembled, promote the elimination of competitor synapses via direct toxic activity and amplification of "eat-me" signals promoting the elimination of weak synapses. I further summarize evidence that neuronal ApoE may be part of a gene regulatory network that normally promotes competitive plasticity, explaining the selective vulnerability of ApoE expressing neurons in AD brains. Lastly, I discuss evidence that sleep may be key to Aβ-orchestrated plasticity, in which sleep is not only induced by Aβ but is also required for Aβ-mediated plasticity, underlining the link between sleep and AD. Together, these results strongly argue that AD is a disease of competitive synaptic plasticity gone awry, a novel perspective that may promote AD research.
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Affiliation(s)
- Zhen Huang
- Departments of Neuroscience and Neurology, University of Wisconsin-Madison, Madison, WI, USA
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10
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Mitchell JW, Midillioglu I, Schauer E, Wang B, Han C, Wildonger J. Coordination of Pickpocket ion channel delivery and dendrite growth in Drosophila sensory neurons. PLoS Genet 2023; 19:e1011025. [PMID: 37943859 PMCID: PMC10662761 DOI: 10.1371/journal.pgen.1011025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 11/21/2023] [Accepted: 10/23/2023] [Indexed: 11/12/2023] Open
Abstract
Sensory neurons enable an organism to perceive external stimuli, which is essential for survival. The sensory capacity of a neuron depends on the elaboration of its dendritic arbor and the localization of sensory ion channels to the dendritic membrane. However, it is not well understood when and how ion channels localize to growing sensory dendrites and whether their delivery is coordinated with growth of the dendritic arbor. We investigated the localization of the DEG/ENaC/ASIC ion channel Pickpocket (Ppk) in the peripheral sensory neurons of developing fruit flies. We used CRISPR-Cas9 genome engineering approaches to tag endogenous Ppk1 and visualize it live, including monitoring Ppk1 membrane localization via a novel secreted split-GFP approach. Fluorescently tagged endogenous Ppk1 localizes to dendrites, as previously reported, and, unexpectedly, to axons and axon terminals. In dendrites, Ppk1 is present throughout actively growing dendrite branches and is stably integrated into the neuronal cell membrane during the expansive growth of the arbor. Although Ppk channels are dispensable for dendrite growth, we found that an over-active channel mutant severely reduces dendrite growth, likely by acting at an internal membrane and not the dendritic membrane. Our data reveal that the molecular motor dynein and recycling endosome GTPase Rab11 are needed for the proper trafficking of Ppk1 to dendrites. Based on our data, we propose that Ppk channel transport is coordinated with dendrite morphogenesis, which ensures proper ion channel density and distribution in sensory dendrites.
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Affiliation(s)
- Josephine W. Mitchell
- Integrated Program in Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Biochemistry Department, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Chemistry and Biochemistry, Kalamazoo College, Kalamazoo, Michigan, United States of America
| | - Ipek Midillioglu
- Pediatrics, University of California, San Diego, La Jolla, California, United States of America
| | - Ethan Schauer
- Pediatrics, University of California, San Diego, La Jolla, California, United States of America
| | - Bei Wang
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York, United States of America
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - Chun Han
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York, United States of America
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - Jill Wildonger
- Biochemistry Department, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Pediatrics, University of California, San Diego, La Jolla, California, United States of America
- Cell & Developmental Biology, School of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
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11
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Niiyama T, Fujimoto S, Imai T. Microglia Are Dispensable for Developmental Dendrite Pruning of Mitral Cells in Mice. eNeuro 2023; 10:ENEURO.0323-23.2023. [PMID: 37890992 PMCID: PMC10644373 DOI: 10.1523/eneuro.0323-23.2023] [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: 08/26/2023] [Revised: 10/18/2023] [Accepted: 10/23/2023] [Indexed: 10/29/2023] Open
Abstract
During early development, neurons in the brain often form excess synaptic connections. Later, they strengthen some connections while eliminating others to build functional neuronal circuits. In the olfactory bulb, a mitral cell initially extends multiple dendrites to multiple glomeruli but eventually forms a single primary dendrite through the activity-dependent dendrite pruning process. Recent studies have reported that microglia facilitate synapse pruning during the circuit remodeling in some systems. It has remained unclear whether microglia are involved in the activity-dependent dendrite pruning in the developing brains. Here, we examined whether microglia are required for the developmental dendrite pruning of mitral cells in mice. To deplete microglia in the fetal brain, we treated mice with a colony-stimulating factor 1 receptor (CSF1R) inhibitor, PLX5622, from pregnancy. Microglia were reduced by >90% in mice treated with PLX5622. However, dendrite pruning of mitral cells was not significantly affected. Moreover, we found no significant differences in the number, density, and size of excitatory synapses formed in mitral cell dendrites. We also found no evidence for the role of microglia in the activity-dependent dendrite remodeling of layer 4 (L4) neurons in the barrel cortex. In contrast, the density of excitatory synapses (dendritic spines) in granule cells in the olfactory bulb was significantly increased in mice treated with PLX5622 at postnatal day (P) 6, suggesting a role for the regulation of dendritic spines. Our results indicate that microglia do not play a critical role in activity-dependent dendrite pruning at the neurite level during early postnatal development in mice.
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Affiliation(s)
- Tetsushi Niiyama
- Graduate School of Medical Sciences, Kyushu University, 812-8582, Fukuoka, Japan
| | - Satoshi Fujimoto
- Graduate School of Medical Sciences, Kyushu University, 812-8582, Fukuoka, Japan
| | - Takeshi Imai
- Graduate School of Medical Sciences, Kyushu University, 812-8582, Fukuoka, Japan
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12
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Chen X, Perry S, Wang B, Wang S, Hu J, Loxterkamp E, Dickman D, Han C. Tissue-specific knockout in Drosophila neuromuscular system reveals ESCRT's role in formation of synapse-derived extracellular vesicles. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.25.559303. [PMID: 37808853 PMCID: PMC10557614 DOI: 10.1101/2023.09.25.559303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Tissue-specific gene knockout by CRISPR/Cas9 is a powerful approach for characterizing gene functions in animal development. However, this approach has been successfully applied in only a small number of Drosophila tissues. The Drosophila motor nervous system is an excellent model system for studying the biology of neuromuscular junction (NMJ). To expand tissue-specific CRISPR to the Drosophila motor system, here we present a CRISPR-mediated tissue-restricted mutagenesis (CRISPR-TRiM) toolkit for knocking out genes in motoneurons, muscles, and glial cells. We validated the efficacy of this toolkit by knocking out known genes in each tissue, demonstrated its orthogonal use with the Gal4/UAS binary expression system, and showed simultaneous knockout of multiple redundant genes. Using these tools, we discovered an essential role for SNARE pathways in NMJ maintenance. Furthermore, we demonstrate that the canonical ESCRT pathway suppresses NMJ bouton growth by downregulating the retrograde Gbb signaling. Lastly, we found that axon termini of motoneurons rely on ESCRT-mediated intra-axonal membrane trafficking to lease extracellular vesicles at the NMJ.
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Affiliation(s)
- Xinchen Chen
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Sarah Perry
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Bei Wang
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Shuran Wang
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Jiayi Hu
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Elizabeth Loxterkamp
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Dion Dickman
- Department of Neurobiology, University of Southern California, Los Angeles, CA 90089, USA
| | - Chun Han
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
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13
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Dirvelyte E, Bujanauskiene D, Jankaityte E, Daugelaviciene N, Kisieliute U, Nagula I, Budvytyte R, Neniskyte U. Genetically encoded phosphatidylserine biosensor for in vitro, ex vivo and in vivo labelling. Cell Mol Biol Lett 2023; 28:59. [PMID: 37501184 PMCID: PMC10373266 DOI: 10.1186/s11658-023-00472-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 06/27/2023] [Indexed: 07/29/2023] Open
Abstract
BACKGROUND The dynamics of phosphatidylserine in the plasma membrane is a tightly regulated feature of eukaryotic cells. Phosphatidylserine (PS) is found preferentially in the inner leaflet of the plasma membrane. Disruption of this asymmetry leads to the exposure of phosphatidylserine on the cell surface and is associated with cell death, synaptic pruning, blood clotting and other cellular processes. Due to the role of phosphatidylserine in widespread cellular functions, an efficient phosphatidylserine probe is needed to study them. Currently, a few different phosphatidylserine labelling tools are available; however, these labels have unfavourable signal-to-noise ratios and are difficult to use in tissues due to limited permeability. Their application in living tissue requires injection procedures that damage the tissue and release damage-associated molecular patterns, which in turn stimulates phosphatidylserine exposure. METHODS For this reason, we developed a novel genetically encoded phosphatidylserine probe based on the C2 domain of the lactadherin (MFG-E8) protein, suitable for labelling exposed phosphatidylserine in various research models. We tested the C2 probe specificity to phosphatidylserine on hybrid bilayer lipid membranes by observing surface plasmon resonance angle shift. Then, we analysed purified fused C2 proteins on different cell culture lines or engineered AAVs encoding C2 probes on tissue cultures after apoptosis induction. For in vivo experiments, neurotropic AAVs were intravenously injected into perinatal mice, and after 2 weeks, brain slices were collected to observe C2-SNAP expression. RESULTS The biophysical analysis revealed the high specificity of the C2 probe for phosphatidylserine. The fused recombinant C2 proteins were suitable for labelling phosphatidylserine on the surface of apoptotic cells in various cell lines. We engineered AAVs and validated them in organotypic brain tissue cultures for non-invasive delivery of the genetically encoded C2 probe and showed that these probes were expressed in the brain in vivo after intravenous AAV delivery to mice. CONCLUSIONS We have demonstrated that the developed genetically encoded PS biosensor can be utilised in a variety of assays as a two-component system of C2 and C2m2 fusion proteins. This system allows for precise quantification and PS visualisation at directly specified threshold levels, enabling the evaluation of PS exposure in both physiological and cell death processes.
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Affiliation(s)
- Eimina Dirvelyte
- VU LSC-EMBL Partnership Institute for Genome Editing Technologies, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Daina Bujanauskiene
- VU LSC-EMBL Partnership Institute for Genome Editing Technologies, Life Sciences Center, Vilnius University, Vilnius, Lithuania
- Institute of Bioscience, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Evelina Jankaityte
- VU LSC-EMBL Partnership Institute for Genome Editing Technologies, Life Sciences Center, Vilnius University, Vilnius, Lithuania
- Institute of Biochemistry, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Neringa Daugelaviciene
- VU LSC-EMBL Partnership Institute for Genome Editing Technologies, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Ugne Kisieliute
- Institute of Bioscience, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Igor Nagula
- VU LSC-EMBL Partnership Institute for Genome Editing Technologies, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Rima Budvytyte
- VU LSC-EMBL Partnership Institute for Genome Editing Technologies, Life Sciences Center, Vilnius University, Vilnius, Lithuania
- Institute of Biochemistry, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Urte Neniskyte
- VU LSC-EMBL Partnership Institute for Genome Editing Technologies, Life Sciences Center, Vilnius University, Vilnius, Lithuania.
- Institute of Bioscience, Life Sciences Center, Vilnius University, Vilnius, Lithuania.
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14
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Wang Y, Zhang R, Huang S, Valverde PTT, Lobb-Rabe M, Ashley J, Venkatasubramanian L, Carrillo RA. Glial Draper signaling triggers cross-neuron plasticity in bystander neurons after neuronal cell death in Drosophila. Nat Commun 2023; 14:4452. [PMID: 37488133 PMCID: PMC10366216 DOI: 10.1038/s41467-023-40142-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 07/07/2023] [Indexed: 07/26/2023] Open
Abstract
Neuronal cell death and subsequent brain dysfunction are hallmarks of aging and neurodegeneration, but how the nearby healthy neurons (bystanders) respond to the death of their neighbors is not fully understood. In the Drosophila larval neuromuscular system, bystander motor neurons can structurally and functionally compensate for the loss of their neighbors by increasing their terminal bouton number and activity. We term this compensation as cross-neuron plasticity, and in this study, we demonstrate that the Drosophila engulfment receptor, Draper, and the associated kinase, Shark, are required for cross-neuron plasticity. Overexpression of the Draper-I isoform boosts cross-neuron plasticity, implying that the strength of plasticity correlates with Draper signaling. In addition, we find that functional cross-neuron plasticity can be induced at different developmental stages. Our work uncovers a role for Draper signaling in cross-neuron plasticity and provides insights into how healthy bystander neurons respond to the loss of their neighboring neurons.
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Affiliation(s)
- Yupu Wang
- Department of Molecular Genetics and Cellular Biology, University of Chicago, Chicago, IL, 60637, USA.
- Neuroscience Institute, University of Chicago, Chicago, IL, 60637, USA.
- Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, VA, 20147, USA.
| | - Ruiling Zhang
- Department of Molecular Genetics and Cellular Biology, University of Chicago, Chicago, IL, 60637, USA
- Neuroscience Institute, University of Chicago, Chicago, IL, 60637, USA
- Committee on Development, Regeneration, and Stem Cell Biology, University of Chicago, Chicago, IL, 60637, USA
| | - Sihao Huang
- Program in Biochemistry and Molecular Biophysics, University of Chicago, Chicago, IL, 60637, USA
| | - Parisa Tajalli Tehrani Valverde
- Department of Molecular Genetics and Cellular Biology, University of Chicago, Chicago, IL, 60637, USA
- Neuroscience Institute, University of Chicago, Chicago, IL, 60637, USA
- Committee on Development, Regeneration, and Stem Cell Biology, University of Chicago, Chicago, IL, 60637, USA
| | - Meike Lobb-Rabe
- Department of Molecular Genetics and Cellular Biology, University of Chicago, Chicago, IL, 60637, USA
- Neuroscience Institute, University of Chicago, Chicago, IL, 60637, USA
- Program in Cell and Molecular Biology, University of Chicago, Chicago, IL, 60637, USA
| | - James Ashley
- Department of Molecular Genetics and Cellular Biology, University of Chicago, Chicago, IL, 60637, USA
- Neuroscience Institute, University of Chicago, Chicago, IL, 60637, USA
| | | | - Robert A Carrillo
- Department of Molecular Genetics and Cellular Biology, University of Chicago, Chicago, IL, 60637, USA.
- Neuroscience Institute, University of Chicago, Chicago, IL, 60637, USA.
- Committee on Development, Regeneration, and Stem Cell Biology, University of Chicago, Chicago, IL, 60637, USA.
- Program in Cell and Molecular Biology, University of Chicago, Chicago, IL, 60637, USA.
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15
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Wang YW, Li Q, Li XY, Zhao YC, Wang CC, Xue CH, Wang YM, Zhang TT. A Comparative Study about the Neuroprotective Effects of DHA-Enriched Phosphatidylserine and EPA-Enriched Phosphatidylserine against Oxidative Damage in Primary Hippocampal Neurons. Mar Drugs 2023; 21:410. [PMID: 37504941 PMCID: PMC10381609 DOI: 10.3390/md21070410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 07/13/2023] [Accepted: 07/18/2023] [Indexed: 07/29/2023] Open
Abstract
Nerve damage caused by accumulated oxidative stress is one of the characteristics and main mechanisms of Alzheimer's disease (AD). Previous studies have shown that phosphatidylserine (PS) rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) plays a significant role in preventing and mitigating the progression of AD. However, whether DHA-PS and EPA-PS can directly protect primary hippocampal neurons against oxidative damage has not been studied. Here, the neuroprotective functions of DHA-PS and EPA-PS against H2O2/t-BHP-induced oxidative damage and the possible mechanisms were evaluated in primary hippocampal neurons. It was found that DHA-PS and EPA-PS could significantly improve cell morphology and promote the restoration of neural network structure. Further studies showed that both of them significantly alleviated oxidative stress-mediated mitochondrial dysfunction. EPA-PS significantly inhibited the phosphorylation of ERK, thus playing an anti-apoptotic role, and EPA-PS significantly increased the protein expressions of p-TrkB and p-CREB, thus playing a neuroprotective role. In addition, EPA-PS, rather than DHA-PS could enhance synaptic plasticity by increasing the expression of SYN, and both could significantly reduce the expression levels of p-GSK3β and p-Tau. These results provide a scientific basis for the use of DHA/EPA-enriched phospholipids in the treatment of neurodegenerative diseases, and also provide a reference for the development of related functional foods.
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Affiliation(s)
- Yi-Wen Wang
- College of Food Science and Engineering, Ocean University of China, Qingdao 266404, China
| | - Qian Li
- College of Food Science and Engineering, Ocean University of China, Qingdao 266404, China
| | - Xiao-Yue Li
- College of Food Science and Engineering, Ocean University of China, Qingdao 266404, China
| | - Ying-Cai Zhao
- College of Food Science and Engineering, Ocean University of China, Qingdao 266404, China
| | - Cheng-Cheng Wang
- College of Food Science and Engineering, Ocean University of China, Qingdao 266404, China
| | - Chang-Hu Xue
- College of Food Science and Engineering, Ocean University of China, Qingdao 266404, China
- Laboratory for Marine Drugs and Bioproducts, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266237, China
| | - Yu-Ming Wang
- College of Food Science and Engineering, Ocean University of China, Qingdao 266404, China
- Laboratory for Marine Drugs and Bioproducts, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266237, China
| | - Tian-Tian Zhang
- College of Food Science and Engineering, Ocean University of China, Qingdao 266404, China
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16
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Ji H, Wang B, Shen Y, Labib D, Lei J, Chen X, Sapar M, Boulanger A, Dura JM, Han C. The Drosophila chemokine-like Orion bridges phosphatidylserine and Draper in phagocytosis of neurons. Proc Natl Acad Sci U S A 2023; 120:e2303392120. [PMID: 37276397 PMCID: PMC10268242 DOI: 10.1073/pnas.2303392120] [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: 02/28/2023] [Accepted: 04/10/2023] [Indexed: 06/07/2023] Open
Abstract
Phagocytic clearance of degenerating neurons is triggered by "eat-me" signals exposed on the neuronal surface. The conserved neuronal eat-me signal phosphatidylserine (PS) and the engulfment receptor Draper (Drpr) mediate phagocytosis of degenerating neurons in Drosophila. However, how PS is recognized by Drpr-expressing phagocytes in vivo remains poorly understood. Using multiple models of dendrite degeneration, we show that the Drosophila chemokine-like protein Orion can bind to PS and is responsible for detecting PS exposure on neurons; it is supplied cell-non-autonomously to coat PS-exposing dendrites and to mediate interactions between PS and Drpr, thus enabling phagocytosis. As a result, the accumulation of Orion on neurons and on phagocytes produces opposite outcomes by potentiating and suppressing phagocytosis, respectively. Moreover, the Orion dosage is a key determinant of the sensitivity of phagocytes to PS exposed on neurons. Lastly, mutagenesis analyses show that the sequence motifs shared between Orion and human immunomodulatory proteins are important for Orion function. Thus, our results uncover a missing link in PS-mediated phagocytosis in Drosophila and imply conserved mechanisms of phagocytosis of neurons.
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Affiliation(s)
- Hui Ji
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY14853
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY14853
| | - Bei Wang
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY14853
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY14853
| | - Yifan Shen
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY14853
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY14853
| | - David Labib
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY14853
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY14853
| | - Joyce Lei
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY14853
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY14853
| | - Xinchen Chen
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY14853
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY14853
| | - Maria Sapar
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY14853
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY14853
| | - Ana Boulanger
- Institute of Human Genetics (IGH), Univ Montpellier, CNRS, Montpellier34090, France
| | - Jean-Maurice Dura
- Institute of Human Genetics (IGH), Univ Montpellier, CNRS, Montpellier34090, France
| | - Chun Han
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY14853
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY14853
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17
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Kira A, Tatsutomi I, Saito K, Murata M, Hattori I, Kajita H, Muraki N, Oda Y, Satoh S, Tsukamoto Y, Kimura S, Onoue K, Yonemura S, Arakawa S, Kato H, Hirashima T, Kawane K. Apoptotic extracellular vesicle formation via local phosphatidylserine exposure drives efficient cell extrusion. Dev Cell 2023:S1534-5807(23)00241-1. [PMID: 37315563 DOI: 10.1016/j.devcel.2023.05.008] [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: 02/12/2022] [Revised: 01/29/2023] [Accepted: 05/17/2023] [Indexed: 06/16/2023]
Abstract
Cell extrusion is a universal mode of cell removal from tissues, and it plays an important role in regulating cell numbers and eliminating unwanted cells. However, the underlying mechanisms of cell delamination from the cell layer are unclear. Here, we report a conserved execution mechanism of apoptotic cell extrusion. We found extracellular vesicle (EV) formation in extruding mammalian and Drosophila cells at a site opposite to the extrusion direction. Lipid-scramblase-mediated local exposure of phosphatidylserine is responsible for EV formation and is crucial for executing cell extrusion. Inhibition of this process disrupts prompt cell delamination and tissue homeostasis. Although the EV has hallmarks of an apoptotic body, its formation is governed by the mechanism of microvesicle formation. Experimental and mathematical modeling analysis illustrated that EV formation promotes neighboring cells' invasion. This study showed that membrane dynamics play a crucial role in cell exit by connecting the actions of the extruding cell and neighboring cells.
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Affiliation(s)
- Akihito Kira
- Department of Frontier Life Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan
| | - Ichiko Tatsutomi
- Department of Frontier Life Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan
| | - Keisuke Saito
- Department of Frontier Life Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan
| | - Machiko Murata
- Department of Frontier Life Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan
| | - Izumi Hattori
- Department of Frontier Life Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan
| | - Haruna Kajita
- Department of Frontier Life Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan
| | - Naoko Muraki
- Department of Frontier Life Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan
| | - Yukako Oda
- Department of Cell Growth and Differentiation, Center for iPS Cell Research & Application, Kyoto University, Kyoto 606-8507, Japan
| | - Saya Satoh
- Institute of Cardiovascular Immunology, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany
| | - Yuta Tsukamoto
- Institute of Cardiovascular Immunology, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany
| | - Seisuke Kimura
- Department of Industrial Life Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan; Center for Plant Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan
| | - Kenta Onoue
- Laboratory for Ultrastructural Research, RIKEN Center for Biosystems Dynamics Research, Hyogo 650-0047, Japan
| | - Shigenobu Yonemura
- Laboratory for Ultrastructural Research, RIKEN Center for Biosystems Dynamics Research, Hyogo 650-0047, Japan; Department of Cell Biology, Tokushima University Graduate School of Medicine, Tokushima 770-8503, Japan
| | - Satoko Arakawa
- Research Core, Institute of Research, Tokyo Medical and Dental University, Tokyo 113-8510, Japan; Department of Pathological Cell Biology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo 113-8510, Japan
| | - Hiroki Kato
- Institute of Cardiovascular Immunology, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany
| | - Tsuyoshi Hirashima
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore; Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117593, Singapore; Japan Science and Technology Agency, PRESTO, Saitama 332-0012, Japan.
| | - Kohki Kawane
- Department of Frontier Life Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan.
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18
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Szabó Á, Vincze V, Chhatre AS, Jipa A, Bognár S, Varga KE, Banik P, Harmatos-Ürmösi A, Neukomm LJ, Juhász G. LC3-associated phagocytosis promotes glial degradation of axon debris after injury in Drosophila models. Nat Commun 2023; 14:3077. [PMID: 37248218 DOI: 10.1038/s41467-023-38755-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 05/09/2023] [Indexed: 05/31/2023] Open
Abstract
Glial engulfment of neuron-derived debris after trauma, during development, and in neurodegenerative diseases supports nervous system functions. However, mechanisms governing the efficiency of debris degradation in glia have remained largely unexplored. Here we show that LC3-associated phagocytosis (LAP), an engulfment pathway assisted by certain autophagy factors, promotes glial phagosome maturation in the Drosophila wing nerve. A LAP-specific subset of autophagy-related genes is required in glia for axon debris clearance, encoding members of the Atg8a (LC3) conjugation system and the Vps34 lipid kinase complex including UVRAG and Rubicon. Phagosomal Rubicon and Atg16 WD40 domain-dependent conjugation of Atg8a mediate proper breakdown of internalized axon fragments, and Rubicon overexpression in glia accelerates debris elimination. Finally, LAP promotes survival following traumatic brain injury. Our results reveal a role of glial LAP in the clearance of neuronal debris in vivo, with potential implications for the recovery of the injured nervous system.
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Affiliation(s)
- Áron Szabó
- Biological Research Center, Institute of Genetics, Eötvös Loránd Research Network (ELKH), Szeged, H-6726, Hungary.
| | - Virág Vincze
- Biological Research Center, Institute of Genetics, Eötvös Loránd Research Network (ELKH), Szeged, H-6726, Hungary
| | - Aishwarya Sanjay Chhatre
- Biological Research Center, Institute of Genetics, Eötvös Loránd Research Network (ELKH), Szeged, H-6726, Hungary
- Doctoral School of Biology, University of Szeged, Szeged, Hungary
| | - András Jipa
- Biological Research Center, Institute of Genetics, Eötvös Loránd Research Network (ELKH), Szeged, H-6726, Hungary
| | - Sarolta Bognár
- Biological Research Center, Institute of Genetics, Eötvös Loránd Research Network (ELKH), Szeged, H-6726, Hungary
| | - Katalin Eszter Varga
- Biological Research Center, Institute of Genetics, Eötvös Loránd Research Network (ELKH), Szeged, H-6726, Hungary
| | - Poulami Banik
- Biological Research Center, Institute of Genetics, Eötvös Loránd Research Network (ELKH), Szeged, H-6726, Hungary
| | - Adél Harmatos-Ürmösi
- Biological Research Center, Institute of Genetics, Eötvös Loránd Research Network (ELKH), Szeged, H-6726, Hungary
| | - Lukas J Neukomm
- Department of Fundamental Neurosciences, University of Lausanne, CH-1005, Lausanne, Switzerland
| | - Gábor Juhász
- Biological Research Center, Institute of Genetics, Eötvös Loránd Research Network (ELKH), Szeged, H-6726, Hungary.
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, H-1117, Hungary.
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19
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Sakuragi T, Nagata S. Regulation of phospholipid distribution in the lipid bilayer by flippases and scramblases. Nat Rev Mol Cell Biol 2023:10.1038/s41580-023-00604-z. [PMID: 37106071 PMCID: PMC10134735 DOI: 10.1038/s41580-023-00604-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/09/2023] [Indexed: 04/29/2023]
Abstract
Cellular membranes function as permeability barriers that separate cells from the external environment or partition cells into distinct compartments. These membranes are lipid bilayers composed of glycerophospholipids, sphingolipids and cholesterol, in which proteins are embedded. Glycerophospholipids and sphingolipids freely move laterally, whereas transverse movement between lipid bilayers is limited. Phospholipids are asymmetrically distributed between membrane leaflets but change their location in biological processes, serving as signalling molecules or enzyme activators. Designated proteins - flippases and scramblases - mediate this lipid movement between the bilayers. Flippases mediate the confined localization of specific phospholipids (phosphatidylserine (PtdSer) and phosphatidylethanolamine) to the cytoplasmic leaflet. Scramblases randomly scramble phospholipids between leaflets and facilitate the exposure of PtdSer on the cell surface, which serves as an important signalling molecule and as an 'eat me' signal for phagocytes. Defects in flippases and scramblases cause various human diseases. We herein review the recent research on the structure of flippases and scramblases and their physiological roles. Although still poorly understood, we address the mechanisms by which they translocate phospholipids between lipid bilayers and how defects cause human diseases.
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Affiliation(s)
- Takaharu Sakuragi
- Biochemistry & Immunology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Shigekazu Nagata
- Biochemistry & Immunology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan.
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20
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Wang Y, Zhang R, Huang S, Valverde PTT, Lobb-Rabe M, Ashley J, Venkatasubramanian L, Carrillo RA. Glial Draper signaling triggers cross-neuron plasticity in bystander neurons after neuronal cell death. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.09.536190. [PMID: 37090512 PMCID: PMC10120647 DOI: 10.1101/2023.04.09.536190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Neuronal cell death and subsequent brain dysfunction are hallmarks of aging and neurodegeneration, but how the nearby healthy neurons (bystanders) respond to the cell death of their neighbors is not fully understood. In the Drosophila larval neuromuscular system, bystander motor neurons can structurally and functionally compensate for the loss of their neighbors by increasing their axon terminal size and activity. We termed this compensation as cross-neuron plasticity, and in this study, we demonstrated that the Drosophila engulfment receptor, Draper, and the associated kinase, Shark, are required in glial cells. Surprisingly, overexpression of the Draper-I isoform boosts cross-neuron plasticity, implying that the strength of plasticity correlates with Draper signaling. Synaptic plasticity normally declines as animals age, but in our system, functional cross-neuron plasticity can be induced at different time points, whereas structural cross-neuron plasticity can only be induced at early stages. Our work uncovers a novel role for glial Draper signaling in cross-neuron plasticity that may enhance nervous system function during neurodegeneration and provides insights into how healthy bystander neurons respond to the loss of their neighboring neurons.
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Bora D, Samir KM, Sharma A, Chilvery S, Bansod S, John SE, Ali Khan M, Godugu C, Shankaraiah N. Exploration of cytotoxic potential and tubulin polymerization inhibition activity of cis-stilbene-1,2,3-triazole congeners. RSC Med Chem 2023; 14:482-490. [PMID: 36970147 PMCID: PMC10034215 DOI: 10.1039/d2md00400c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 01/01/2023] [Indexed: 02/08/2023] Open
Abstract
To scrutinize cis-stilbene based molecules with potential anticancer and tubulin polymerization inhibition activity, a new series of cis-stilbene-1,2,3-triazole congeners was designed and synthesized via a click chemistry protocol. The cytotoxicity of these compounds 9a-j and 10a-j was screened against lung, breast, skin and colorectal cancer cell lines. Based on the results of MTT assay, we further evaluated the selectivity index of the most active compound 9j (IC50 3.25 ± 1.04 μM on HCT-116) by comparing its IC50 value (72.24 ± 1.20 μM) to that of the normal human cell line. Further, to confirm apoptotic cell death, cell morphology and staining studies (AO/EB, DAPI and Annexin V/PI) were carried out. The outcomes of studies showed apoptotic features like change in cell shape, cornering of nuclei, micronuclei formation, fragmented, bright, horseshoe-shaped nuclei, etc. Moreover, active compound 9j displayed G2/M phase cell cycle arrest with significant tubulin polymerization inhibition activity with an IC50 value of 4.51 μM. Additionally, in silico ADMET, molecular docking and molecular dynamic studies of 9j with 3E22 protein proved the binding of the compound at the colchicine binding site of tubulin.
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Affiliation(s)
- Darshana Bora
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER) Hyderabad - 500 037 India
| | - Khan Mehtab Samir
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER) Hyderabad - 500 037 India
| | - Anamika Sharma
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER) Hyderabad - 500 037 India
| | - Shrilekha Chilvery
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER) Hyderabad - 500 037 India
| | - Sapana Bansod
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER) Hyderabad - 500 037 India
| | - Stephy Elza John
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER) Hyderabad - 500 037 India
| | - Mursalim Ali Khan
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER) Hyderabad - 500 037 India
| | - Chandraiah Godugu
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER) Hyderabad - 500 037 India
| | - Nagula Shankaraiah
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER) Hyderabad - 500 037 India
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22
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Karuparti S, Yeung AT, Wang B, Guicardi PF, Han C. A toolkit for converting Gal4 into LexA and Flippase transgenes in Drosophila. G3 (BETHESDA, MD.) 2023; 13:jkad003. [PMID: 36617215 PMCID: PMC9997562 DOI: 10.1093/g3journal/jkad003] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 10/01/2022] [Accepted: 01/02/2023] [Indexed: 01/09/2023]
Abstract
Drosophila has been a powerful model system for biological studies due to the wide range of genetic tools established for it. Among these tools, Gal4 is the most abundant, offering unparalleled tissue and developmental stage specificity for gene manipulation. In comparison, other genetic reagents are far fewer in choices. Here we present a genetic toolkit for converting Gal4 strains into LexA and Flippase transgenes through simple genetic crosses and fluorescence screening. We demonstrate the proof-of-principle by converting ten Gal4 lines that exhibit diverse tissue specificities and examined the activity patterns of the converted LexA and Flippase lines. Gal4-to-LexA and Flp conversion is fast and convenient and should greatly expand the choices of LexA and Flp for binary expression and FRT-based mosaic analysis, respectively, in Drosophila.
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Affiliation(s)
- Sasidhar Karuparti
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Ann T Yeung
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Bei Wang
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Pedro F Guicardi
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Chun Han
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
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23
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Marmor-Kollet N, Berkun V, Cummings G, Keren-Shaul H, David E, Addadi Y, Schuldiner O. Actin-dependent astrocytic infiltration is a key step for axon defasciculation during remodeling. Cell Rep 2023; 42:112117. [PMID: 36790930 PMCID: PMC9989824 DOI: 10.1016/j.celrep.2023.112117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 10/17/2022] [Accepted: 01/28/2023] [Indexed: 02/16/2023] Open
Abstract
Astrocytes are essential for synapse formation, maturation, and plasticity; however, their function during developmental neuronal remodeling is largely unknown. To identify astrocytic molecules required for axon pruning of mushroom body (MB) γ neurons in Drosophila, we profiled astrocytes before (larva) and after (adult) remodeling. Focusing on genes enriched in larval astrocytes, we identified 12 astrocytic genes that are required for axon pruning, including the F-actin regulators Actin-related protein 2/3 complex, subunit 1 (Arpc1) and formin3 (form3). Interestingly, perturbing astrocytic actin dynamics does not affect their gross morphology, migration, or transforming growth factor β (TGF-β) secretion. In contrast, actin dynamics is required for astrocyte infiltration into the axon bundle at the onset of pruning. Remarkably, decreasing axonal adhesion facilitates infiltration by Arpc1 knockdown (KD) astrocytes and promotes axon pruning. Conversely, increased axonal adhesion reduces lobe infiltration by wild-type (WT) astrocytes. Together, our findings suggest that actin-dependent astrocytic infiltration is a key step in axon pruning, thus promoting our understanding of neuron-glia interactions during remodeling.
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Affiliation(s)
- Neta Marmor-Kollet
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel; Department of Molecular Neuroscience, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Victoria Berkun
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Gideon Cummings
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Hadas Keren-Shaul
- Department of Immunology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Eyal David
- Department of Immunology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Yoseph Addadi
- Weizmann Institute of Science, Life Sciences Core Facilities, Rehovot 7610001, Israel
| | - Oren Schuldiner
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel; Department of Molecular Neuroscience, Weizmann Institute of Science, Rehovot 7610001, Israel.
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24
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Abstract
Membranes are multifunctional supramolecular assemblies that encapsulate our cells and the organelles within them. Glycerophospholipids are the most abundant component of membranes. They make up the majority of the lipid bilayer and play both structural and functional roles. Each organelle has a different phospholipid composition critical for its function that results from dynamic interplay and regulation of numerous lipid-metabolizing enzymes and lipid transporters. Because lipid structures and localizations are not directly genetically encoded, chemistry has much to offer to the world of lipid biology in the form of precision tools for visualizing lipid localization and abundance, manipulating lipid composition, and in general decoding the functions of lipids in cells.In this Account, we provide an overview of our recent efforts in this space focused on two overarching and complementary goals: imaging and editing the phospholipidome. On the imaging front, we have harnessed the power of bioorthogonal chemistry to develop fluorescent reporters of specific lipid pathways. Substantial efforts have centered on phospholipase D (PLD) signaling, which generates the humble lipid phosphatidic acid (PA) that acts variably as a biosynthetic intermediate and signaling agent. Though PLD is a hydrolase that generates PA from abundant phosphatidylcholine (PC) lipids, we have exploited its transphosphatidylation activity with exogenous clickable alcohols followed by bioorthogonal tagging to generate fluorescent lipid reporters of PLD signaling in a set of methods termed IMPACT.IMPACT and its variants have facilitated many biological discoveries. Using the rapid and fluorogenic tetrazine ligation, it has revealed the spatiotemporal dynamics of disease-relevant G protein-coupled receptor signaling and interorganelle lipid transport. IMPACT using diazirine photo-cross-linkers has enabled identification of lipid-protein interactions relevant to alcohol-related diseases. Varying the alcohol reporter can allow for organelle-selective labeling, and varying the bioorthogonal detection reagent can afford super-resolution lipid imaging via expansion microscopy. Combination of IMPACT with genome-wide CRISPR screening has revealed genes that regulate physiological PLD signaling.PLD enzymes themselves can also act as tools for precision editing of the phospholipid content of membranes. An optogenetic PLD for conditional blue-light-stimulated synthesis of PA on defined organelle compartments led to the discovery of the role of organelle-specific pools of PA in regulating oncogenic Hippo signaling. Directed enzyme evolution of PLD, enabled by IMPACT, has yielded highly active superPLDs with broad substrate tolerance and an ability to edit membrane phospholipid content and synthesize designer phospholipids in vitro. Finally, azobenzene-containing PA analogues represent an alternative, all-chemical strategy for light-mediated control of PA signaling.Collectively, the strategies described here summarize our progress to date in tackling the challenge of assigning precise functions to defined pools of phospholipids in cells. They also point to new challenges and directions for future study, including extension of imaging and membrane editing tools to other classes of lipids. We envision that continued application of bioorthogonal chemistry, optogenetics, and directed evolution will yield new tools and discoveries to interrogate the phospholipidome and reveal new mechanisms regulating phospholipid homeostasis and roles for phospholipids in cell signaling.
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Affiliation(s)
- Din-Chi Chiu
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York 14853, United States
| | - Jeremy M Baskin
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York 14853, United States
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25
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Li H, Sung HH, Huang YC, Cheng YJ, Yeh HF, Pi H, Giniger E, Chien CT. Fringe-positive Golgi outposts unite temporal Furin 2 convertase activity and spatial Delta signal to promote dendritic branch retraction. Cell Rep 2022; 40:111372. [PMID: 36130510 DOI: 10.1016/j.celrep.2022.111372] [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: 03/08/2022] [Revised: 07/07/2022] [Accepted: 08/25/2022] [Indexed: 11/19/2022] Open
Abstract
Golgi outposts (GOPs) in dendrites are known for their role in promoting branch extension, but whether GOPs have other functions is unclear. We found that terminal branches of Drosophila class IV dendritic arborization (C4da) neurons actively grow during the early third-instar (E3) larval stage but retract in the late third (L3) stage. Interestingly, the Fringe (Fng) glycosyltransferase localizes increasingly at GOPs in distal dendritic regions through the E3 to the L3 stage. Expression of the endopeptidase Furin 2 (Fur2), which proteolyzes and inactivates Fng, decreases from E3 to L3 in C4da neurons, thereby increasing Fng-positive GOPs in dendrites. The epidermal Delta ligand and neuronal Notch receptor, the substrate for Fng-mediated O-glycosylation, also negatively regulate dendrite growth. Fng inhibits actin dynamics in dendrites, linking dendritic branch retraction to suppression of the C4da-mediated thermal nociception response in late larval stages. Thus, Fng-positive GOPs function in dendrite retraction, which would add another function to the repertoire of GOPs in dendrite arborization.
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Affiliation(s)
- Hsun Li
- Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan; Taiwan International Graduate Program in Interdisciplinary Neuroscience, National Yang Ming Chiao Tung University and Academia Sinica, Taipei 11529, Taiwan
| | - Hsin-Ho Sung
- Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Yi-Chun Huang
- Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Ying-Ju Cheng
- Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Hsiao-Fong Yeh
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 33302, Taiwan
| | - Haiwei Pi
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 33302, Taiwan
| | - Edward Giniger
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Cheng-Ting Chien
- Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan; Taiwan International Graduate Program in Interdisciplinary Neuroscience, National Yang Ming Chiao Tung University and Academia Sinica, Taipei 11529, Taiwan; Neuroscience Program of Academia Sinica, Academia Sinica, Taipei 11529, Taiwan.
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26
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A photo-switchable assay system for dendrite degeneration and repair in Drosophila melanogaster. Proc Natl Acad Sci U S A 2022; 119:e2204577119. [PMID: 35969739 PMCID: PMC9407391 DOI: 10.1073/pnas.2204577119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Neurodegeneration arising from aging, injury, or diseases has devastating health consequences. Whereas neuronal survival and axon degeneration have been studied extensively, much less is known about how neurodegeneration affects dendrites, in part due to the limited assay systems available. To develop an assay for dendrite degeneration and repair, we used photo-switchable caspase-3 (caspase-Light-Oxygen-Voltage-sensing [caspase-LOV]) in peripheral class 4 dendrite arborization (c4da) neurons to induce graded neurodegeneration by adjusting illumination duration during development and adulthood in Drosophila melanogaster. We found that both developing and mature c4da neurons were able to survive while sustaining mild neurodegeneration induced by moderate caspase-LOV activation. Further, we observed active dendrite addition and dendrite regeneration in developing and mature c4da neurons, respectively. Using this assay, we found that the mouse Wallerian degeneration slow (WldS) protein can protect c4da neurons from caspase-LOV-induced dendrite degeneration and cell death. Furthermore, our data show that WldS can reduce dendrite elimination without affecting dendrite addition. In summary, we successfully established a photo-switchable assay system in both developing and mature neurons and used WldS as a test case to study the mechanisms underlying dendrite regeneration and repair.
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27
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Shin HW, Takatsu H. Regulatory Roles of N- and C-Terminal Cytoplasmic Regions of P4-ATPases. Chem Pharm Bull (Tokyo) 2022; 70:524-532. [DOI: 10.1248/cpb.c22-00042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Hye-Won Shin
- Graduate School of Pharmaceutical Sciences, Kyoto University
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28
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Almasieh M, Faris H, Levin LA. Pivotal roles for membrane phospholipids in axonal degeneration. Int J Biochem Cell Biol 2022; 150:106264. [PMID: 35868612 DOI: 10.1016/j.biocel.2022.106264] [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: 05/09/2022] [Revised: 07/16/2022] [Accepted: 07/17/2022] [Indexed: 10/17/2022]
Abstract
Membrane phospholipids are critical components of several signaling pathways. Maintained in a variety of asymmetric distributions, their trafficking across the membrane can be induced by intra-, extra-, and intercellular events. A familiar example is the externalization of phosphatidylserine from the inner leaflet to the outer leaflet in apoptosis, inducing phagocytosis of the soma. Recently, it has been recognized that phospholipids in the axonal membrane may be a signal for axonal degeneration, regeneration, or other processes. This review focuses on key recent developments and areas for ongoing investigations. KEY FACTS: Phosphatidylserine externalization propagates along an axon after axonal injury and is delayed in the Wallerian degeneration slow (WldS) mutant. The ATP8A2 flippase mutant has spontaneous axonal degeneration. Microdomains of axonal degeneration in spheroid bodies have differential externalization of phosphatidylserine and phosphatidylethanolamine. Phospholipid trafficking could represent a mechanism for coordinated axonal degeneration and elimination, i.e. axoptosis, analogous to apoptosis of the cell body.
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Affiliation(s)
- Mohammadali Almasieh
- Department of Ophthalmology and Visual Sciences, McGill University, Montreal, Canada
| | - Hannah Faris
- Department of Ophthalmology and Visual Sciences, McGill University, Montreal, Canada
| | - Leonard A Levin
- Department of Ophthalmology and Visual Sciences, McGill University, Montreal, Canada; Department of Neurology and Neurosurgery, McGill University, Montreal, Canada.
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29
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Zohar-Fux M, Ben-Hamo-Arad A, Arad T, Volin M, Shklyar B, Hakim-Mishnaevski K, Porat-Kuperstein L, Kurant E, Toledano H. The phagocytic cyst cells in Drosophila testis eliminate germ cell progenitors via phagoptosis. SCIENCE ADVANCES 2022; 8:eabm4937. [PMID: 35714186 PMCID: PMC9205596 DOI: 10.1126/sciadv.abm4937] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 05/04/2022] [Indexed: 06/15/2023]
Abstract
Phagoptosis is a frequently occurring nonautonomous cell death pathway in which phagocytes eliminate viable cells. While it is thought that phosphatidylserine (PS) "eat-me" signals on target cells initiate the process, the precise sequence of events is largely unknown. Here, we show that in Drosophila testes, progenitor germ cells are spontaneously removed by neighboring cyst cells through phagoptosis. Using live imaging with multiple markers, we demonstrate that cyst cell-derived early/late endosomes and lysosomes fused around live progenitors to acidify them, before DNA fragmentation and substantial PS exposure on the germ cell surface. Furthermore, the phagocytic receptor Draper is expressed on cyst cell membranes and is necessary for phagoptosis. Significantly, germ cell death is blocked by knockdown of either the endosomal component Rab5 or the lysosomal associated protein Lamp1, within the cyst cells. These data ascribe an active role for phagocytic cyst cells in removal of live germ cell progenitors.
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Affiliation(s)
- Maayan Zohar-Fux
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, 199 Aba Hushi Avenue, Mount Carmel, Haifa 3498838, Israel
| | - Aya Ben-Hamo-Arad
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, 199 Aba Hushi Avenue, Mount Carmel, Haifa 3498838, Israel
| | - Tal Arad
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, 199 Aba Hushi Avenue, Mount Carmel, Haifa 3498838, Israel
| | - Marina Volin
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, 199 Aba Hushi Avenue, Mount Carmel, Haifa 3498838, Israel
| | - Boris Shklyar
- Bioimaging Unit, Faculty of Natural Sciences, University of Haifa, 199 Aba Hushi Avenue, Mount Carmel, Haifa 3498838, Israel
| | - Ketty Hakim-Mishnaevski
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, 199 Aba Hushi Avenue, Mount Carmel, Haifa 3498838, Israel
| | - Lilach Porat-Kuperstein
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, 199 Aba Hushi Avenue, Mount Carmel, Haifa 3498838, Israel
| | - Estee Kurant
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, 199 Aba Hushi Avenue, Mount Carmel, Haifa 3498838, Israel
| | - Hila Toledano
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, 199 Aba Hushi Avenue, Mount Carmel, Haifa 3498838, Israel
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30
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Luo J, Lian Q, Zhu D, Zhao M, Mei T, Shang B, Yang Z, Liu C, Xu W, Zhou L, Wu K, Liu X, Lai Y, Mao F, Li W, Zuo C, Zhang K, Lin M, Zhuo Y, Liu Y, Lu L, Zhao L. PLSCR1 Promotes Apoptosis and Clearance of Retinal Ganglion Cells in Glaucoma Pathogenesis. Genes Dis 2022. [DOI: 10.1016/j.gendis.2022.05.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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31
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Parker SE, Bellingham MC, Woodruff TM. Complement drives circuit modulation in the adult brain. Prog Neurobiol 2022; 214:102282. [DOI: 10.1016/j.pneurobio.2022.102282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 03/24/2022] [Accepted: 05/02/2022] [Indexed: 11/16/2022]
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32
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Kurematsu C, Sawada M, Ohmuraya M, Tanaka M, Kuboyama K, Ogino T, Matsumoto M, Oishi H, Inada H, Ishido Y, Sakakibara Y, Nguyen HB, Thai TQ, Kohsaka S, Ohno N, Yamada MK, Asai M, Sokabe M, Nabekura J, Asano K, Tanaka M, Sawamoto K. Synaptic pruning of murine adult-born neurons by microglia depends on phosphatidylserine. J Exp Med 2022; 219:213073. [PMID: 35297954 PMCID: PMC9195048 DOI: 10.1084/jem.20202304] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 08/13/2021] [Accepted: 11/30/2021] [Indexed: 12/21/2022] Open
Abstract
New neurons, continuously added in the adult olfactory bulb (OB) and hippocampus, are involved in information processing in neural circuits. Here, we show that synaptic pruning of adult-born neurons by microglia depends on phosphatidylserine (PS), whose exposure on dendritic spines is inversely correlated with their input activity. To study the role of PS in spine pruning by microglia in vivo, we developed an inducible transgenic mouse line, in which the exposed PS is masked by a dominant-negative form of milk fat globule-EGF-factor 8 (MFG-E8), MFG-E8D89E. In this transgenic mouse, the spine pruning of adult-born neurons by microglia is impaired in the OB and hippocampus. Furthermore, the electrophysiological properties of these adult-born neurons are altered in MFG-E8D89E mice. These data suggest that PS is involved in the microglial spine pruning and the functional maturation of adult-born neurons. The MFG-E8D89E-based genetic approach shown in this study has broad applications for understanding the biology of PS-mediated phagocytosis in vivo.
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Affiliation(s)
- Chihiro Kurematsu
- Department of Developmental and Regenerative Neurobiology, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Masato Sawada
- Department of Developmental and Regenerative Neurobiology, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.,Division of Neural Development and Regeneration, National Institute for Physiological Sciences, Okazaki, Japan
| | - Masaki Ohmuraya
- Department of Genetics, Hyogo College of Medicine, Nishinomiya, Japan
| | - Motoki Tanaka
- Department of Disease Model, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, Japan
| | - Kazuya Kuboyama
- Department of Developmental and Regenerative Neurobiology, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Takashi Ogino
- Department of Developmental and Regenerative Neurobiology, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Mami Matsumoto
- Department of Developmental and Regenerative Neurobiology, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.,Section of Electron Microscopy, Supportive Center for Brain Research, National Institute for Physiological Sciences, Okazaki, Japan
| | - Hisashi Oishi
- Department of Comparative and Experimental Medicine, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Hiroyuki Inada
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki, Japan
| | - Yuri Ishido
- Department of Developmental and Regenerative Neurobiology, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Yukina Sakakibara
- Department of Developmental and Regenerative Neurobiology, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Huy Bang Nguyen
- Section of Electron Microscopy, Supportive Center for Brain Research, National Institute for Physiological Sciences, Okazaki, Japan.,Department of Anatomy, Faculty of Medicine, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | - Truc Quynh Thai
- Section of Electron Microscopy, Supportive Center for Brain Research, National Institute for Physiological Sciences, Okazaki, Japan.,Department of Histology-Embryology-Genetics, Faculty of Basic Medical Sciences, Pham Ngoc Thach University of Medicine, Ho Chi Minh City, Vietnam
| | - Shinichi Kohsaka
- National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Japan
| | - Nobuhiko Ohno
- Department of Anatomy, Division of Histology and Cell Biology, Jichi Medical University, School of Medicine, Shimotsuke, Japan.,Division of Ultrastructural Research, National Institute for Physiological Sciences, Okazaki, Japan
| | - Maki K Yamada
- Department of Neuropharmacology, Kagawa School of Pharmaceutical Sciences and Institute of Neuroscience, Tokushima Bunri University, Sanuki, Japan
| | - Masato Asai
- Department of Disease Model, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, Japan
| | - Masahiro Sokabe
- Mechanobiology Laboratory, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Junichi Nabekura
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki, Japan
| | - Kenichi Asano
- Laboratory of Immune Regulation, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| | - Masato Tanaka
- Laboratory of Immune Regulation, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| | - Kazunobu Sawamoto
- Department of Developmental and Regenerative Neurobiology, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.,Division of Neural Development and Regeneration, National Institute for Physiological Sciences, Okazaki, Japan
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Boulanger A, Dura JM. Neuron-glia crosstalk in neuronal remodeling and degeneration: Neuronal signals inducing glial cell phagocytic transformation in Drosophila. Bioessays 2022; 44:e2100254. [PMID: 35315125 DOI: 10.1002/bies.202100254] [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: 10/25/2021] [Revised: 03/04/2022] [Accepted: 03/07/2022] [Indexed: 11/09/2022]
Abstract
Neuronal remodeling is a conserved mechanism that eliminates unwanted neurites and can include the loss of cell bodies. In these processes, a key role for glial cells in events from synaptic pruning to neuron elimination has been clearly identified in the last decades. Signals sent from dying neurons or neurites to be removed are received by appropriate glial cells. After receiving these signals, glial cells infiltrate degenerating sites and then, engulf and clear neuronal debris through phagocytic mechanisms. There are few identified or proposed signals and receptors involved in neuron-glia crosstalk, which induces the transformation of glial cells to phagocytes during neuronal remodeling in Drosophila. Many of these signaling pathways are conserved in mammals. Here, we particularly emphasize the role of Orion, a recently identified neuronal CX3 C chemokine-like secreted protein, which induces astrocyte infiltration and engulfment during mushroom body neuronal remodeling. Although, chemokine signaling was not described previously in insects we propose that chemokine-like involvement in neuron/glial cell interaction is an evolutionarily ancient mechanism.
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Affiliation(s)
- Ana Boulanger
- IGH, Université de Montpellier, CNRS, Montpellier, France
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Brar HK, Dey S, Bhardwaj S, Pande D, Singh P, Dey S, Ghosh-Roy A. Dendrite regeneration in C. elegans is controlled by the RAC GTPase CED-10 and the RhoGEF TIAM-1. PLoS Genet 2022; 18:e1010127. [PMID: 35344539 PMCID: PMC8989329 DOI: 10.1371/journal.pgen.1010127] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 04/07/2022] [Accepted: 02/28/2022] [Indexed: 01/30/2023] Open
Abstract
Neurons are vulnerable to physical insults, which compromise the integrity of both dendrites and axons. Although several molecular pathways of axon regeneration are identified, our knowledge of dendrite regeneration is limited. To understand the mechanisms of dendrite regeneration, we used the PVD neurons in C. elegans with stereotyped branched dendrites. Using femtosecond laser, we severed the primary dendrites and axon of this neuron. After severing the primary dendrites near the cell body, we observed sprouting of new branches from the proximal site within 6 hours, which regrew further with time in an unstereotyped manner. This was accompanied by reconnection between the proximal and distal dendrites, and fusion among the higher-order branches as reported before. We quantified the regeneration pattern into three aspects–territory length, number of branches, and fusion phenomena. Axonal injury causes a retraction of the severed end followed by a Dual leucine zipper kinase-1 (DLK-1) dependent regrowth from the severed end. We tested the roles of the major axon regeneration signalling hubs such as DLK-1-RPM-1, cAMP elevation, let-7 miRNA, AKT-1, Phosphatidylserine (PS) exposure/PS in dendrite regeneration. We found that neither dendrite regrowth nor fusion was affected by the axon injury pathway molecules. Surprisingly, we found that the RAC GTPase, CED-10 and its upstream GEF, TIAM-1 play a cell-autonomous role in dendrite regeneration. Additionally, the function of CED-10 in epidermal cell is critical for post-dendrotomy fusion phenomena. This work describes a novel regulatory mechanism of dendrite regeneration and provides a framework for understanding the cellular mechanism of dendrite regeneration using PVD neuron as a model system. The knowledge of the repair of injured neural circuits comes from the study of the regeneration of injured axons. The information receiving neurites, namely dendrites, are also vulnerable to physical insult during stroke and trauma. However, little knowledge is available on the mechanism of dendrite regeneration since the study of Cajal. In order to get insight into this process, we severed both axon and dendrites of PVD neuron in C. elegans using laser. By comparing the roles of axon regeneration pathways in both dendrite and axon regeneration in this neuron, we found that dendrite regeneration is independent of molecular mechanisms involving axon regrowth. We discovered that dendrite regeneration is dependent on the RAC GTPase CED-10 and GEF TIAM-1. Moreover, we found that CED-10 plays roles within both neuron and in the surrounding epithelia for mounting regeneration response to dendrite injury. This work provides mechanistic insight into the process of dendrite repair after physical injury.
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Affiliation(s)
- Harjot Kaur Brar
- Department of Cellular & Molecular Neuroscience, National Brain Research Centre, Manesar, Haryana, India
| | - Swagata Dey
- Department of Cellular & Molecular Neuroscience, National Brain Research Centre, Manesar, Haryana, India
| | - Smriti Bhardwaj
- Department of Cellular & Molecular Neuroscience, National Brain Research Centre, Manesar, Haryana, India
| | - Devashish Pande
- Department of Cellular & Molecular Neuroscience, National Brain Research Centre, Manesar, Haryana, India
| | - Pallavi Singh
- Department of Cellular & Molecular Neuroscience, National Brain Research Centre, Manesar, Haryana, India
| | - Shirshendu Dey
- Fluorescence Microscopy Division, Bruker India Scientific Pvt. Ltd., International Trade Tower, Nehru Place, New Delhi, India
| | - Anindya Ghosh-Roy
- Department of Cellular & Molecular Neuroscience, National Brain Research Centre, Manesar, Haryana, India
- * E-mail:
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35
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Liu KE, Raymond MH, Ravichandran KS, Kucenas S. Clearing Your Mind: Mechanisms of Debris Clearance After Cell Death During Neural Development. Annu Rev Neurosci 2022; 45:177-198. [PMID: 35226828 PMCID: PMC10157384 DOI: 10.1146/annurev-neuro-110920-022431] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Neurodevelopment and efferocytosis have fascinated scientists for decades. How an organism builds a nervous system that is precisely tuned for efficient behaviors and survival and how it simultaneously manages constant somatic cell turnover are complex questions that have resulted in distinct fields of study. Although neurodevelopment requires the overproduction of cells that are subsequently pruned back, very few studies marry these fields to elucidate the cellular and molecular mechanisms that drive nervous system development through the lens of cell clearance. In this review, we discuss these fields to highlight exciting areas of future synergy. We first review neurodevelopment from the perspective of overproduction and subsequent refinement and then discuss who clears this developmental debris and the mechanisms that control these events. We then end with how a more deliberate merger of neurodevelopment and efferocytosis could reframe our understanding of homeostasis and disease and discuss areas of future study. Expected final online publication date for the Annual Review of Neuroscience, Volume 45 is July 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Kendra E Liu
- Neuroscience Graduate Program, University of Virginia, Charlottesville, Virginia, USA; .,Program in Fundamental Neuroscience, University of Virginia, Charlottesville, Virginia, USA
| | - Michael H Raymond
- Neuroscience Graduate Program, University of Virginia, Charlottesville, Virginia, USA; .,Center for Clearance, University of Virginia, Charlottesville, Virginia, USA
| | - Kodi S Ravichandran
- Neuroscience Graduate Program, University of Virginia, Charlottesville, Virginia, USA; .,Center for Clearance, University of Virginia, Charlottesville, Virginia, USA.,Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, USA.,VIB-UGent Center for Inflammation Research and the Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Sarah Kucenas
- Neuroscience Graduate Program, University of Virginia, Charlottesville, Virginia, USA; .,Program in Fundamental Neuroscience, University of Virginia, Charlottesville, Virginia, USA.,Department of Biology, University of Virginia, Charlottesville, Virginia, USA
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Ji H, Sapar ML, Sarkar A, Wang B, Han C. Phagocytosis and self-destruction break down dendrites of Drosophila sensory neurons at distinct steps of Wallerian degeneration. Proc Natl Acad Sci U S A 2022; 119:e2111818119. [PMID: 35058357 PMCID: PMC8795528 DOI: 10.1073/pnas.2111818119] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 12/01/2021] [Indexed: 12/12/2022] Open
Abstract
After injury, severed dendrites and axons expose the "eat-me" signal phosphatidylserine (PS) on their surface while they break down. The degeneration of injured axons is controlled by a conserved Wallerian degeneration (WD) pathway, which is thought to activate neurite self-destruction through Sarm-mediated nicotinamide adenine dinucleotide (NAD+) depletion. While neurite PS exposure is known to be affected by genetic manipulations of NAD+, how the WD pathway coordinates both neurite PS exposure and self-destruction and whether PS-induced phagocytosis contributes to neurite breakdown in vivo remain unknown. Here, we show that in Drosophila sensory dendrites, PS exposure and self-destruction are two sequential steps of WD resulting from Sarm activation. Surprisingly, phagocytosis is the main driver of dendrite degeneration induced by both genetic NAD+ disruptions and injury. However, unlike neuronal Nmnat loss, which triggers PS exposure only and results in phagocytosis-dependent dendrite degeneration, injury activates both PS exposure and self-destruction as two redundant means of dendrite degeneration. Furthermore, the axon-death factor Axed is only partially required for self-destruction of injured dendrites, acting in parallel with PS-induced phagocytosis. Lastly, injured dendrites exhibit a unique rhythmic calcium-flashing that correlates with WD. Therefore, both NAD+-related general mechanisms and dendrite-specific programs govern PS exposure and self-destruction in injury-induced dendrite degeneration in vivo.
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Affiliation(s)
- Hui Ji
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Maria L Sapar
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Ankita Sarkar
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Bei Wang
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Chun Han
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853;
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
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Marques RF, Duncan KE. SYNGR4 and PLEKHB1 deregulation in motor neurons of amyotrophic lateral sclerosis models: potential contributions to pathobiology. Neural Regen Res 2022; 17:266-270. [PMID: 34269186 PMCID: PMC8463983 DOI: 10.4103/1673-5374.317960] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Amyotrophic lateral sclerosis is the most common adult-onset neurodegenerative disease affecting motor neurons. Its defining feature is progressive loss of motor neuron function in the cortex, brainstem, and spinal cord, leading to paralysis and death. Despite major advances in identifying genes that can cause disease when mutated and model the disease in animals and cellular models, it still remains unclear why motor symptoms suddenly appear after a long pre-symptomatic phase of apparently normal function. One hypothesis is that age-related deregulation of specific proteins within key cell types, especially motor neurons themselves, initiates disease symptom appearance and may also drive progressive degeneration. Genome-wide in vivo cell-type-specific screening tools are enabling identification of candidates for such proteins. In this minireview, we first briefly discuss the methodology used in a recent study that applied a motor neuron-specific RNA-Seq screening approach to a standard model of TAR DNA-binding protein-43 (TDP-43)-driven amyotrophic lateral sclerosis. A key finding of this study is that synaptogyrin-4 and pleckstrin homology domain-containing family B member 1 are also deregulated at the protein level within motor neurons of two unrelated mouse models of mutant TDP-43 driven amyotrophic lateral sclerosis. Guided by what is known about molecular and cellular functions of these proteins and their orthologs, we outline here specific hypotheses for how changes in their levels might potentially alter cellular physiology of motor neurons and detrimentally affect motor neuron function. Where possible, we also discuss how this information could potentially be used in a translational context to develop new therapeutic strategies for this currently incurable, devastating disease.
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Affiliation(s)
- Rita F Marques
- Neuronal Translational Control Research Group, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg,, Germany
| | - Kent E Duncan
- Neuronal Translational Control Research Group, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg,, Germany
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Ko KW, Devault L, Sasaki Y, Milbrandt J, DiAntonio A. Live imaging reveals the cellular events downstream of SARM1 activation. eLife 2021; 10:e71148. [PMID: 34779400 PMCID: PMC8612704 DOI: 10.7554/elife.71148] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 11/12/2021] [Indexed: 12/15/2022] Open
Abstract
SARM1 is an inducible NAD+ hydrolase that triggers axon loss and neuronal cell death in the injured and diseased nervous system. While SARM1 activation and enzyme function are well defined, the cellular events downstream of SARM1 activity but prior to axonal demise are much less well understood. Defects in calcium, mitochondria, ATP, and membrane homeostasis occur in injured axons, but the relationships among these events have been difficult to disentangle because prior studies analyzed large collections of axons in which cellular events occur asynchronously. Here, we used live imaging of mouse sensory neurons with single axon resolution to investigate the cellular events downstream of SARM1 activity. Our studies support a model in which SARM1 NADase activity leads to an ordered sequence of events from loss of cellular ATP, to defects in mitochondrial movement and depolarization, followed by calcium influx, externalization of phosphatidylserine, and loss of membrane permeability prior to catastrophic axonal self-destruction.
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Affiliation(s)
- Kwang Woo Ko
- Washington University School of MedicineSt LouisUnited States
| | - Laura Devault
- Washington University School of MedicineSt LouisUnited States
| | - Yo Sasaki
- Genetics, Washington University School of MedicineSt LouisUnited States
| | - Jeffrey Milbrandt
- Genetics, Hope Center for Neurological Disorders, Washington University School of MedicineSt LouisUnited States
| | - Aaron DiAntonio
- Developmental Biology, Needleman Center for Neurometabolism and Axonal Therapeutics, Washington University School of MedicineSt LouisUnited States
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39
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Joseph K, Kirsch M, Johnston M, Münkel C, Stieglitz T, Haas CA, Hofmann UG. Transcriptional characterization of the glial response due to chronic neural implantation of flexible microprobes. Biomaterials 2021; 279:121230. [PMID: 34736153 DOI: 10.1016/j.biomaterials.2021.121230] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 10/20/2021] [Accepted: 10/24/2021] [Indexed: 01/13/2023]
Abstract
Long term implantation of (micro-)probes into neural tissue causes unique and disruptive responses. In this study, we investigate the transcriptional trajectory of glial cells responding to chronic implantation of 380 μm flexible micro-probes for up to 18 weeks. Transcriptomic analysis shows a rapid activation of microglial cells and a strong reactive astrocytic polarization, both of which are lost over the chronic of the implant duration. Animals that were implanted for 18 weeks show a transcriptional profile similar to non-implanted controls, with increased expression of genes associated with wound healing and angiogenesis, which raises hope of a normalization of the neuropil to the pre-injury state when using flexible probes. Nevertheless, our data shows that a subset of genes upregulated after 18 weeks belong to the family of immediate early genes, which indicates that structural and functional remodeling is not complete at this time point. Our results confirm and extend previous work on the molecular changes resulting from the presence of neural probes and provide a rational basis for developing interventional strategies to control them.
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Affiliation(s)
- Kevin Joseph
- Neuroelectronic Systems, Department of Neurosurgery, Medical Center, University of Freiburg, Germany; Department of Neurosurgery, Medical Center University of Freiburg, Germany; Faculty of Medicine, University of Freiburg, Germany; BrainLinks-BrainTools, University of Freiburg, Germany.
| | - Matthias Kirsch
- BrainLinks-BrainTools, University of Freiburg, Germany; Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Midori Johnston
- Faculty of Medicine, University of Freiburg, Germany; BrainLinks-BrainTools, University of Freiburg, Germany; Experimental Epilepsy Research, Dept. of Neurosurgery, Medical Center- University of Freiburg, Germany
| | - Christian Münkel
- Neuroelectronic Systems, Department of Neurosurgery, Medical Center, University of Freiburg, Germany; Department of Neurosurgery, Medical Center University of Freiburg, Germany; Faculty of Medicine, University of Freiburg, Germany
| | - Thomas Stieglitz
- BrainLinks-BrainTools, University of Freiburg, Germany; Laboratory for Biomedical Microtechnology, Department of Microsystems Engineering-IMTEK, Faculty of Engineering, University of Freiburg, Germany
| | - Carola A Haas
- Faculty of Medicine, University of Freiburg, Germany; Experimental Epilepsy Research, Dept. of Neurosurgery, Medical Center- University of Freiburg, Germany
| | - Ulrich G Hofmann
- Neuroelectronic Systems, Department of Neurosurgery, Medical Center, University of Freiburg, Germany; Department of Neurosurgery, Medical Center University of Freiburg, Germany; Faculty of Medicine, University of Freiburg, Germany; BrainLinks-BrainTools, University of Freiburg, Germany
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40
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Yong Y, Hunter-Chang S, Stepanova E, Deppmann C. Axonal spheroids in neurodegeneration. Mol Cell Neurosci 2021; 117:103679. [PMID: 34678457 PMCID: PMC8742877 DOI: 10.1016/j.mcn.2021.103679] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/12/2021] [Accepted: 10/15/2021] [Indexed: 10/20/2022] Open
Abstract
Axonal spheroids are bubble-like biological features that form on most degenerating axons, yet little is known about their influence on degenerative processes. Their formation and growth has been observed in response to various degenerative triggers such as injury, oxidative stress, inflammatory factors, and neurotoxic molecules. They often contain cytoskeletal elements and organelles, and, depending on the pathological insult, can colocalize with disease-related proteins such as amyloid precursor protein (APP), ubiquitin, and motor proteins. Initial formation of axonal spheroids depends on the disruption of axonal and membrane tension governed by cytoskeleton structure and calcium levels. Shortly after spheroid formation, the engulfment signal phosphatidylserine (PS) is exposed on the outer leaflet of spheroid plasma membrane, suggesting an important role for axonal spheroids in phagocytosis and debris clearance during degeneration. Spheroids can grow until they rupture, allowing pro-degenerative factors to exit the axon into extracellular space and accelerating neurodegeneration. Though much remains to be discovered in this area, axonal spheroid research promises to lend insight into the etiologies of neurodegenerative disease, and may be an important target for therapeutic intervention. This review summarizes over 100 years of work, describing what is known about axonal spheroid structure, regulation and function.
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Affiliation(s)
- Yu Yong
- Department of Biology, University of Virginia, Charlottesville, VA 22903, USA
| | - Sarah Hunter-Chang
- Neuroscience Graduate Program, University of Virginia, Charlottesville, VA 22903, USA
| | - Ekaterina Stepanova
- Department of Biology, University of Virginia, Charlottesville, VA 22903, USA
| | - Christopher Deppmann
- Department of Biology, University of Virginia, Charlottesville, VA 22903, USA; Neuroscience Graduate Program, University of Virginia, Charlottesville, VA 22903, USA.
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41
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Woo E, Sansing LH, Arnsten AFT, Datta D. Chronic Stress Weakens Connectivity in the Prefrontal Cortex: Architectural and Molecular Changes. CHRONIC STRESS 2021; 5:24705470211029254. [PMID: 34485797 PMCID: PMC8408896 DOI: 10.1177/24705470211029254] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 06/14/2021] [Indexed: 12/26/2022]
Abstract
Chronic exposure to uncontrollable stress causes loss of spines and dendrites in the prefrontal cortex (PFC), a recently evolved brain region that provides top-down regulation of thought, action, and emotion. PFC neurons generate top-down goals through recurrent excitatory connections on spines. This persistent firing is the foundation for higher cognition, including working memory, and abstract thought. However, exposure to acute uncontrollable stress drives high levels of catecholamine release in the PFC, which activates feedforward calcium-cAMP signaling pathways to open nearby potassium channels, rapidly weakening synaptic connectivity to reduce persistent firing. Chronic stress exposures can further exacerbate these signaling events leading to loss of spines and resulting in marked cognitive impairment. In this review, we discuss how stress signaling mechanisms can lead to spine loss, including changes to BDNF-mTORC1 signaling, calcium homeostasis, actin dynamics, and mitochondrial actions that engage glial removal of spines through inflammatory signaling. Stress signaling events may be amplified in PFC spines due to cAMP magnification of internal calcium release. As PFC dendritic spine loss is a feature of many cognitive disorders, understanding how stress affects the structure and function of the PFC will help to inform strategies for treatment and prevention.
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Affiliation(s)
- Elizabeth Woo
- Department of Neuroscience, Yale Medical School, New Haven, CT, USA.,Department of Neurology, Yale Medical School, New Haven, CT, USA
| | - Lauren H Sansing
- Department of Neurology, Yale Medical School, New Haven, CT, USA
| | - Amy F T Arnsten
- Department of Neuroscience, Yale Medical School, New Haven, CT, USA
| | - Dibyadeep Datta
- Department of Neuroscience, Yale Medical School, New Haven, CT, USA
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Cornell J, Salinas S, Huang HY, Zhou M. Microglia regulation of synaptic plasticity and learning and memory. Neural Regen Res 2021; 17:705-716. [PMID: 34472455 PMCID: PMC8530121 DOI: 10.4103/1673-5374.322423] [Citation(s) in RCA: 163] [Impact Index Per Article: 54.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Microglia are the resident macrophages of the central nervous system. Microglia possess varied morphologies and functions. Under normal physiological conditions, microglia mainly exist in a resting state and constantly monitor their microenvironment and survey neuronal and synaptic activity. Through the C1q, C3 and CR3 “Eat Me” and CD47 and SIRPα “Don’t Eat Me” complement pathways, as well as other pathways such as CX3CR1 signaling, resting microglia regulate synaptic pruning, a process crucial for the promotion of synapse formation and the regulation of neuronal activity and synaptic plasticity. By mediating synaptic pruning, resting microglia play an important role in the regulation of experience-dependent plasticity in the barrel cortex and visual cortex after whisker removal or monocular deprivation, and also in the regulation of learning and memory, including the modulation of memory strength, forgetfulness, and memory quality. As a response to brain injury, infection or neuroinflammation, microglia become activated and increase in number. Activated microglia change to an amoeboid shape, migrate to sites of inflammation and secrete proteins such as cytokines, chemokines and reactive oxygen species. These molecules released by microglia can lead to synaptic plasticity and learning and memory deficits associated with aging, Alzheimer’s disease, traumatic brain injury, HIV-associated neurocognitive disorder, and other neurological or mental disorders such as autism, depression and post-traumatic stress disorder. With a focus mainly on recently published literature, here we reviewed the studies investigating the role of resting microglia in synaptic plasticity and learning and memory, as well as how activated microglia modulate disease-related plasticity and learning and memory deficits. By summarizing the function of microglia in these processes, we aim to provide an overview of microglia regulation of synaptic plasticity and learning and memory, and to discuss the possibility of microglia manipulation as a therapeutic to ameliorate cognitive deficits associated with aging, Alzheimer’s disease, traumatic brain injury, HIV-associated neurocognitive disorder, and mental disorders.
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Affiliation(s)
- Jessica Cornell
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, USA
| | - Shelbi Salinas
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, USA
| | - Hou-Yuan Huang
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, USA
| | - Miou Zhou
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, USA
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43
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Park J, Choi Y, Jung E, Lee S, Sohn J, Chung W. Microglial MERTK eliminates phosphatidylserine-displaying inhibitory post-synapses. EMBO J 2021; 40:e107121. [PMID: 34013588 PMCID: PMC8327958 DOI: 10.15252/embj.2020107121] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 04/09/2021] [Accepted: 04/16/2021] [Indexed: 01/11/2023] Open
Abstract
Glia contribute to synapse elimination through phagocytosis in the central nervous system. Despite the important roles of this process in development and neurological disorders, the identity and regulation of the "eat-me" signal that initiates glia-mediated phagocytosis of synapses has remained incompletely understood. Here, we generated conditional knockout mice with neuronal-specific deletion of the flippase chaperone Cdc50a, to induce stable exposure of phosphatidylserine, a well-known "eat-me" signal for apoptotic cells, on the neuronal outer membrane. Surprisingly, acute Cdc50a deletion in mature neurons causes preferential phosphatidylserine exposure in neuronal somas and specific loss of inhibitory post-synapses without effects on other synapses, resulting in abnormal excitability and seizures. Ablation of microglia or the deletion of microglial phagocytic receptor Mertk prevents the loss of inhibitory post-synapses and the seizure phenotype, indicating that microglial phagocytosis is responsible for inhibitory post-synapse elimination. Moreover, we found that phosphatidylserine is used for microglia-mediated pruning of inhibitory post-synapses in normal brains, suggesting that phosphatidylserine serves as a general "eat-me" signal for inhibitory post-synapse elimination.
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Affiliation(s)
- Jungjoo Park
- Department of Biological SciencesKorea Advanced Institute of Science and TechnologyDaejeonKorea
| | - Yeeun Choi
- Department of Biological SciencesKorea Advanced Institute of Science and TechnologyDaejeonKorea
| | - Eunji Jung
- Department of Biological SciencesKorea Advanced Institute of Science and TechnologyDaejeonKorea
| | - Seung‐Hee Lee
- Department of Biological SciencesKorea Advanced Institute of Science and TechnologyDaejeonKorea
| | - Jong‐Woo Sohn
- Department of Biological SciencesKorea Advanced Institute of Science and TechnologyDaejeonKorea
| | - Won‐Suk Chung
- Department of Biological SciencesKorea Advanced Institute of Science and TechnologyDaejeonKorea
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44
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Auzmendi J, Akyuz E, Lazarowski A. The role of P-glycoprotein (P-gp) and inwardly rectifying potassium (Kir) channels in sudden unexpected death in epilepsy (SUDEP). Epilepsy Behav 2021; 121:106590. [PMID: 31706919 DOI: 10.1016/j.yebeh.2019.106590] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 09/17/2019] [Accepted: 09/23/2019] [Indexed: 12/13/2022]
Abstract
Sudden unexpected death in epilepsy (SUDEP) is the major cause of death that affects patients with epilepsy. The risk of SUDEP increases according to the frequency and severity of uncontrolled seizures; therefore, SUDEP risk is higher in patients with refractory epilepsy (RE), in whom most antiepileptic drugs (AEDs) are ineffective for both seizure control and SUDEP prevention. Consequently, RE and SUDEP share a multidrug resistance (MDR) phenotype, which is mainly associated with brain overexpression of ABC-transporters such as P-glycoprotein (P-gp). The activity of P-gp can also contribute to membrane depolarization and affect the normal function of neurons and cardiomyocytes. Other molecular regulators of membrane potential are the inwardly rectifying potassium channels (Kir), whose genetic variants have been related to both epilepsy and heart dysfunctions. Although it has been suggested that dysfunctions of the cardiac, respiratory, and brainstem arousal systems are the causes of SUDEP, the molecular basis for explaining its dysfunctions remain unknown. In rats, repetitive seizures or status epilepticus induced high expression of P-gp and loss Kir expression in the brain and heart, and promoted membrane depolarization, malignant bradycardia, and the high rate of mortality. Here we reviewed clinical and experimental evidences suggesting that abnormal expression of depolarizing/repolarizing factors as P-gp and Kir could favor persistent depolarization of membranes without any rapid functional recovery capacity. This condition induced by convulsive stress could be the molecular mechanism leading to acquired severe bradycardia, as an ineffective heart response generating the appropriate scenario for SUDEP development. This article is part of the Special Issue "NEWroscience 2018".
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Affiliation(s)
- Jerónimo Auzmendi
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina; INFIBIOC, Departamento de Bioquímica Clínica, Facultad de Farmacia y Bioquímica (FFyB), Universidad de Buenos Aires (UBA), Buenos Aires, Argentina
| | - Enes Akyuz
- Yozgat Bozok University, Medical Faculty, Department of Biophysics, Erdoğan Akdağ Yerleşkesi, 66100 Yozgat, Turkey
| | - Alberto Lazarowski
- INFIBIOC, Departamento de Bioquímica Clínica, Facultad de Farmacia y Bioquímica (FFyB), Universidad de Buenos Aires (UBA), Buenos Aires, Argentina.
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Ristovski M, Farhat D, Bancud SEM, Lee JY. Lipid Transporters Beam Signals from Cell Membranes. MEMBRANES 2021; 11:562. [PMID: 34436325 PMCID: PMC8399137 DOI: 10.3390/membranes11080562] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 07/21/2021] [Accepted: 07/22/2021] [Indexed: 12/12/2022]
Abstract
Lipid composition in cellular membranes plays an important role in maintaining the structural integrity of cells and in regulating cellular signaling that controls functions of both membrane-anchored and cytoplasmic proteins. ATP-dependent ABC and P4-ATPase lipid transporters, two integral membrane proteins, are known to contribute to lipid translocation across the lipid bilayers on the cellular membranes. In this review, we will highlight current knowledge about the role of cholesterol and phospholipids of cellular membranes in regulating cell signaling and how lipid transporters participate this process.
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Affiliation(s)
- Miliça Ristovski
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; (M.R.); (D.F.); (S.E.M.B.)
- Translational and Molecular Medicine Program, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Danny Farhat
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; (M.R.); (D.F.); (S.E.M.B.)
- Biomedical Sciences Program, Faculty of Science, University of Ottawa, Ottawa, ON K1H 6N5, Canada
| | - Shelly Ellaine M. Bancud
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; (M.R.); (D.F.); (S.E.M.B.)
- Translational and Molecular Medicine Program, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Jyh-Yeuan Lee
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; (M.R.); (D.F.); (S.E.M.B.)
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46
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Cosker K, Mallach A, Limaye J, Piers TM, Staddon J, Neame SJ, Hardy J, Pocock JM. Microglial signalling pathway deficits associated with the patient derived R47H TREM2 variants linked to AD indicate inability to activate inflammasome. Sci Rep 2021; 11:13316. [PMID: 34172778 PMCID: PMC8233372 DOI: 10.1038/s41598-021-91207-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 05/20/2021] [Indexed: 02/05/2023] Open
Abstract
The R47H variant of the microglial membrane receptor TREM2 is linked to increased risk of late onset Alzheimer's disease. Human induced pluripotent stem cell derived microglia (iPS-Mg) from patient iPSC lines expressing the AD-linked R47Hhet TREM2 variant, common variant (Cv) or an R47Hhom CRISPR edited line and its isogeneic control, demonstrated that R47H-expressing iPS-Mg expressed a deficit in signal transduction in response to the TREM2 endogenous ligand phosphatidylserine with reduced pSYK-pERK1/2 signalling and a reduced NLRP3 inflammasome response, (including ASC speck formation, Caspase-1 activation and IL-1beta secretion). Apoptotic cell phagocytosis and soluble TREM2 shedding were unaltered, suggesting a disjoint between these pathways and the signalling cascades downstream of TREM2 in R47H-expressing iPS-Mg, whilst metabolic deficits in glycolytic capacity and maximum respiration were reversed when R47H expressing iPS-Mg were exposed to PS+ expressing cells. These findings suggest that R47H-expressing microglia are unable to respond fully to cell damage signals such as phosphatidylserine, which may contribute to the progression of neurodegeneration in late-onset AD.
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Affiliation(s)
- Katharina Cosker
- grid.83440.3b0000000121901201Department of Neuroinflammation, University College London, Queen Square Institute of Neurology, 1 Wakefield Street, London, WC1N 1PJ UK
| | - Anna Mallach
- grid.83440.3b0000000121901201Department of Neuroinflammation, University College London, Queen Square Institute of Neurology, 1 Wakefield Street, London, WC1N 1PJ UK
| | - Janhavi Limaye
- grid.83440.3b0000000121901201Department of Neuroinflammation, University College London, Queen Square Institute of Neurology, 1 Wakefield Street, London, WC1N 1PJ UK
| | - Thomas M. Piers
- grid.83440.3b0000000121901201Department of Neuroinflammation, University College London, Queen Square Institute of Neurology, 1 Wakefield Street, London, WC1N 1PJ UK
| | - James Staddon
- grid.428696.7Eisai Ltd, Mosquito Way, Hatfield, AL10 9SN UK
| | | | - John Hardy
- grid.436283.80000 0004 0612 2631Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, Queen Square, London, WC1N 3BG UK ,grid.83440.3b0000000121901201Dementia Research Institute, University College, London, UCL, Reta Lila Weston Institute, UCL Queen Square Institute of Neurology, 1 Wakefield Street, London, WC1N 1PJ UK ,grid.24515.370000 0004 1937 1450NIHR University College London Hospitals Biomedical Research Centre and Institute for Advanced Study, The Hong Kong University of Science and Technology, Hong Kong SAR, China
| | - Jennifer M. Pocock
- grid.83440.3b0000000121901201Department of Neuroinflammation, University College London, Queen Square Institute of Neurology, 1 Wakefield Street, London, WC1N 1PJ UK
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Yin C, Peterman E, Rasmussen JP, Parrish JZ. Transparent Touch: Insights From Model Systems on Epidermal Control of Somatosensory Innervation. Front Cell Neurosci 2021; 15:680345. [PMID: 34135734 PMCID: PMC8200473 DOI: 10.3389/fncel.2021.680345] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 04/28/2021] [Indexed: 12/28/2022] Open
Abstract
Somatosensory neurons (SSNs) densely innervate our largest organ, the skin, and shape our experience of the world, mediating responses to sensory stimuli including touch, pressure, and temperature. Historically, epidermal contributions to somatosensation, including roles in shaping innervation patterns and responses to sensory stimuli, have been understudied. However, recent work demonstrates that epidermal signals dictate patterns of SSN skin innervation through a variety of mechanisms including targeting afferents to the epidermis, providing instructive cues for branching morphogenesis, growth control and structural stability of neurites, and facilitating neurite-neurite interactions. Here, we focus onstudies conducted in worms (Caenorhabditis elegans), fruit flies (Drosophila melanogaster), and zebrafish (Danio rerio): prominent model systems in which anatomical and genetic analyses have defined fundamental principles by which epidermal cells govern SSN development.
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Affiliation(s)
| | | | | | - Jay Z. Parrish
- Department of Biology, University of Washington, Seattle, WA, United States
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48
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Koreman GT, Xu Y, Hu Q, Zhang Z, Allen SE, Wolfner MF, Wang B, Han C. Upgraded CRISPR/Cas9 tools for tissue-specific mutagenesis in Drosophila. Proc Natl Acad Sci U S A 2021; 118:e2014255118. [PMID: 33782117 PMCID: PMC8040800 DOI: 10.1073/pnas.2014255118] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
CRISPR/Cas9 has emerged as a powerful technology for tissue-specific mutagenesis. However, tissue-specific CRISPR/Cas9 tools currently available in Drosophila remain deficient in three significant ways. First, many existing gRNAs are inefficient, such that further improvements of gRNA expression constructs are needed for more efficient and predictable mutagenesis in both somatic and germline tissues. Second, it has been difficult to label mutant cells in target tissues with current methods. Lastly, application of tissue-specific mutagenesis at present often relies on Gal4-driven Cas9, which hampers the flexibility and effectiveness of the system. Here, we tackle these deficiencies by building upon our previous CRISPR-mediated tissue-restricted mutagenesis (CRISPR-TRiM) tools. First, we significantly improved gRNA efficiency in somatic tissues by optimizing multiplexed gRNA design. Similarly, we also designed efficient dual-gRNA vectors for the germline. Second, we developed methods to positively and negatively label mutant cells in tissue-specific mutagenesis by incorporating co-CRISPR reporters into gRNA expression vectors. Lastly, we generated genetic reagents for convenient conversion of existing Gal4 drivers into tissue-specific Cas9 lines based on homology-assisted CRISPR knock-in. In this way, we expand the choices of Cas9 for CRISPR-TRiM analysis to broader tissues and developmental stages. Overall, our upgraded CRISPR/Cas9 tools make tissue-specific mutagenesis more versatile, reliable, and effective in Drosophila These improvements may be also applied to other model systems.
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Affiliation(s)
- Gabriel T Koreman
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
| | - Yineng Xu
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
| | - Qinan Hu
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Zijing Zhang
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Sarah E Allen
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Mariana F Wolfner
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Bei Wang
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853;
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
| | - Chun Han
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853;
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
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49
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Butler CA, Popescu AS, Kitchener EJA, Allendorf DH, Puigdellívol M, Brown GC. Microglial phagocytosis of neurons in neurodegeneration, and its regulation. J Neurochem 2021; 158:621-639. [PMID: 33608912 DOI: 10.1111/jnc.15327] [Citation(s) in RCA: 118] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 01/13/2021] [Accepted: 02/10/2021] [Indexed: 02/06/2023]
Abstract
There is growing evidence that excessive microglial phagocytosis of neurons and synapses contributes to multiple brain pathologies. RNA-seq and genome-wide association (GWAS) studies have linked multiple phagocytic genes to neurodegenerative diseases, and knock-out of phagocytic genes has been found to protect against neurodegeneration in animal models, suggesting that excessive microglial phagocytosis contributes to neurodegeneration. Here, we review recent evidence that microglial phagocytosis of live neurons and synapses causes neurodegeneration in animal models of Alzheimer's disease and other tauopathies, Parkinson's disease, frontotemporal dementias, multiple sclerosis, retinal degeneration and neurodegeneration induced by ischaemia, infection or ageing. We also review factors regulating microglial phagocytosis of neurons, including: nucleotides, frackalkine, phosphatidylserine, calreticulin, UDP, CD47, sialylation, complement, galectin-3, Apolipoprotein E, phagocytic receptors, Siglec receptors, cytokines, microglial epigenetics and expression profile. Some of these factors may be potential treatment targets to prevent neurodegeneration mediated by excessive microglial phagocytosis of live neurons and synapses.
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Affiliation(s)
- Claire A Butler
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Alma S Popescu
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | | | | | - Mar Puigdellívol
- Department of Biochemistry, University of Cambridge, Cambridge, UK.,Departament de Biomedicina, Facultat de Medicina, Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
| | - Guy C Brown
- Department of Biochemistry, University of Cambridge, Cambridge, UK
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50
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Sokolova D, Childs T, Hong S. Insight into the role of phosphatidylserine in complement-mediated synapse loss in Alzheimer's disease. Fac Rev 2021; 10:19. [PMID: 33718936 PMCID: PMC7946395 DOI: 10.12703/r/10-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The innate immune system plays an integral role in the brain. Synaptic pruning, a fundamental process in developmental circuit refinement, is partially mediated by neuroimmune signalling at the synapse. In particular, microglia, the major tissue-resident macrophages of the brain, and the classical complement cascade, an innate immune pathway that aids in the clearance of unwanted material, have been implicated in mediating synapse elimination. Emerging data suggest that improper signalling of the innate immune pathway at the synapse leads to pathological synapse loss in age-related neurodegenerative diseases, including Alzheimer's disease. Now the key questions are whether synapses are targeted by complement and, if so, which synapses are vulnerable to elimination. Here, we review recent work implicating C1q, the initiator of the classical complement cascade, and surrounding glia as mediators of synapse loss. We examine how synapses could undergo apoptosis-like pathways in the Alzheimer brain, which may lead to the externalisation of phosphatidylserine on synapses. Finally, we discuss potential roles for microglia and astrocytes in this 'synaptic apoptosis'. Critical insight into neuroimmune regulatory pathways on synapses will be key to developing effective targets against pathological synapse loss in dementia.
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Affiliation(s)
- Dimitra Sokolova
- UK Dementia Research Institute, Institute of Neurology, University College London, Gower Street, London WC1E 6BT, UK
| | - Thomas Childs
- UK Dementia Research Institute, Institute of Neurology, University College London, Gower Street, London WC1E 6BT, UK
| | - Soyon Hong
- UK Dementia Research Institute, Institute of Neurology, University College London, Gower Street, London WC1E 6BT, UK
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