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Leier HC, Foden AJ, Jindal DA, Wilkov AJ, Van der Linden Costello P, Vanderzalm PJ, Coutinho-Budd JC, Tabuchi M, Broihier HT. Glia control experience-dependent plasticity in an olfactory critical period. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.05.602232. [PMID: 39005309 PMCID: PMC11245089 DOI: 10.1101/2024.07.05.602232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Sensory experience during developmental critical periods has lifelong consequences for circuit function and behavior, but the molecular and cellular mechanisms through which experience causes these changes are not well understood. The Drosophila antennal lobe houses synapses between olfactory sensory neurons (OSNs) and downstream projection neurons (PNs) in stereotyped glomeruli. Many glomeruli exhibit structural plasticity in response to early-life odor exposure, indicating a general sensitivity of the fly olfactory circuitry to early sensory experience. We recently found that glia regulate the development of the antennal lobe in young adult flies, leading us to ask if glia also drive experience-dependent plasticity. Here we define a critical period for structural and functional plasticity of OSN-PN synapses in the ethyl butyrate (EB)-sensitive glomerulus VM7. EB exposure for the first two days post-eclosion drives large-scale reductions in glomerular volume, presynapse number, and post-synaptic activity. The highly conserved engulfment receptor Draper is required for this critical period plasticity. Specifically, ensheathing glia upregulate Draper expression, invade the VM7 glomerulus, and phagocytose OSN presynaptic terminals in response to critical-period EB exposure. Crucially, synapse pruning during the critical period has long-term consequences for circuit function since both OSN-PN synapse number and spontaneous activity of PNs remain persistently decreased. These data demonstrate experience-dependent pruning of synapses in olfactory circuitry and argue that the Drosophila antennal lobe will be a powerful model for defining the function of glia in critical period plasticity.
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Affiliation(s)
- Hans C Leier
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, United States
| | - Alexander J Foden
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, United States
| | - Darren A Jindal
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, United States
| | - Abigail J Wilkov
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, United States
| | | | - Pamela J Vanderzalm
- Department of Biology, John Carroll University, University Heights, United States
| | - Jaeda C Coutinho-Budd
- Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, United States
| | - Masashi Tabuchi
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, United States
| | - Heather T Broihier
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, United States
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2
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Jindal DA, Leier HC, Salazar G, Foden AJ, Seitz EA, Wilkov AJ, Coutinho-Budd JC, Broihier HT. Early Draper-mediated glial refinement of neuropil architecture and synapse number in the Drosophila antennal lobe. Front Cell Neurosci 2023; 17:1166199. [PMID: 37333889 PMCID: PMC10272751 DOI: 10.3389/fncel.2023.1166199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 05/15/2023] [Indexed: 06/20/2023] Open
Abstract
Glial phagocytic activity refines connectivity, though molecular mechanisms regulating this exquisitely sensitive process are incompletely defined. We developed the Drosophila antennal lobe as a model for identifying molecular mechanisms underlying glial refinement of neural circuits in the absence of injury. Antennal lobe organization is stereotyped and characterized by individual glomeruli comprised of unique olfactory receptor neuronal (ORN) populations. The antennal lobe interacts extensively with two glial subtypes: ensheathing glia wrap individual glomeruli, while astrocytes ramify considerably within them. Phagocytic roles for glia in the uninjured antennal lobe are largely unknown. Thus, we tested whether Draper regulates ORN terminal arbor size, shape, or presynaptic content in two representative glomeruli: VC1 and VM7. We find that glial Draper limits the size of individual glomeruli and restrains their presynaptic content. Moreover, glial refinement is apparent in young adults, a period of rapid terminal arbor and synapse growth, indicating that synapse addition and elimination occur simultaneously. Draper has been shown to be expressed in ensheathing glia; unexpectedly, we find it expressed at high levels in late pupal antennal lobe astrocytes. Surprisingly, Draper plays differential roles in ensheathing glia and astrocytes in VC1 and VM7. In VC1, ensheathing glial Draper plays a more significant role in shaping glomerular size and presynaptic content; while in VM7, astrocytic Draper plays the larger role. Together, these data indicate that astrocytes and ensheathing glia employ Draper to refine circuitry in the antennal lobe before the terminal arbors reach their mature form and argue for local heterogeneity of neuron-glia interactions.
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Affiliation(s)
- Darren A. Jindal
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH, United States
| | - Hans C. Leier
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH, United States
| | - Gabriela Salazar
- Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, United States
| | - Alexander J. Foden
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH, United States
| | - Elizabeth A. Seitz
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH, United States
| | - Abigail J. Wilkov
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH, United States
| | - Jaeda C. Coutinho-Budd
- Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, United States
| | - Heather T. Broihier
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH, United States
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3
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Vargas‐Franco D, Kalra R, Draper I, Pacak CA, Asakura A, Kang PB. The Notch signaling pathway in skeletal muscle health and disease. Muscle Nerve 2022; 66:530-544. [PMID: 35968817 PMCID: PMC9804383 DOI: 10.1002/mus.27684] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 07/20/2022] [Accepted: 07/24/2022] [Indexed: 01/05/2023]
Abstract
The Notch signaling pathway is a key regulator of skeletal muscle development and regeneration. Over the past decade, the discoveries of three new muscle disease genes have added a new dimension to the relationship between the Notch signaling pathway and skeletal muscle: MEGF10, POGLUT1, and JAG2. We review the clinical syndromes associated with pathogenic variants in each of these genes, known molecular and cellular functions of their protein products with a particular focus on the Notch signaling pathway, and potential novel therapeutic targets that may emerge from further investigations of these diseases. The phenotypes associated with two of these genes, POGLUT1 and JAG2, clearly fall within the realm of muscular dystrophy, whereas the third, MEGF10, is associated with a congenital myopathy/muscular dystrophy overlap syndrome classically known as early-onset myopathy, areflexia, respiratory distress, and dysphagia. JAG2 is a canonical Notch ligand, POGLUT1 glycosylates the extracellular domain of Notch receptors, and MEGF10 interacts with the intracellular domain of NOTCH1. Additional genes and their encoded proteins relevant to muscle function and disease with links to the Notch signaling pathway include TRIM32, ATP2A1 (SERCA1), JAG1, PAX7, and NOTCH2NLC. There is enormous potential to identify convergent mechanisms of skeletal muscle disease and new therapeutic targets through further investigations of the Notch signaling pathway in the context of skeletal muscle development, maintenance, and disease.
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Affiliation(s)
| | - Raghav Kalra
- Division of Pediatric NeurologyUniversity of Florida College of MedicineGainesvilleFlorida
| | - Isabelle Draper
- Molecular Cardiology Research InstituteTufts Medical CenterBostonMassachusetts
| | - Christina A. Pacak
- Paul and Sheila Wellstone Muscular Dystrophy CenterUniversity of Minnesota Medical SchoolMinneapolisMinnesota
- Department of NeurologyUniversity of Minnesota Medical SchoolMinneapolisMinnesota
| | - Atsushi Asakura
- Paul and Sheila Wellstone Muscular Dystrophy CenterUniversity of Minnesota Medical SchoolMinneapolisMinnesota
- Department of NeurologyUniversity of Minnesota Medical SchoolMinneapolisMinnesota
| | - Peter B. Kang
- Paul and Sheila Wellstone Muscular Dystrophy CenterUniversity of Minnesota Medical SchoolMinneapolisMinnesota
- Department of NeurologyUniversity of Minnesota Medical SchoolMinneapolisMinnesota
- Institute for Translational NeuroscienceUniversity of Minnesota Medical SchoolMinneapolisMinnesota
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4
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Croci C, Traverso M, Baratto S, Iacomino M, Pedemonte M, Caroli F, Scala M, Bruno C, Fiorillo C. Congenital myopathy associated with a novel mutation in MEGF10 gene, myofibrillar alteration and progressive course. ACTA MYOLOGICA : MYOPATHIES AND CARDIOMYOPATHIES : OFFICIAL JOURNAL OF THE MEDITERRANEAN SOCIETY OF MYOLOGY 2022; 41:111-116. [PMID: 36349186 PMCID: PMC9628799 DOI: 10.36185/2532-1900-076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 09/19/2022] [Indexed: 01/24/2023]
Abstract
Early-onset myopathy, areflexia, respiratory distress, and dysphagia (EMARDD) is caused by homozygous or compound heterozygous mutation in the MEGF10 gene (OMIM #614399). Phenotypic spectrum of EMARDD is variable, ranging from severe infantile forms in which patients are ventilator-dependent and die in childhood, to milder chronic disorders with a more favorable course (mild variant, mvEMARDD). Here we describe a 22 years old boy, offspring of consanguineous parents, presenting a congenital myopathic phenotype since infancy with elbow contractures and scoliosis. The patient developed a slowly progressive muscle weakness with impaired walking, rhinolalia, dysphagia, and respiratory involvement, which required noninvasive ventilation therapy since the age of 16 years. First muscle biopsy revealed unspecific muscle damage, with fiber size variation, internal nuclei and fibrosis. Myofibrillar alterations were noted at a second muscle biopsy including whorled fibres, cytoplasmic inclusion and minicores. Exome sequencing identified a homozygous mutation in MEGF10 gene, c.2096G > C (p.Cys699Ser), inherited by both parents. This variant, not reported in public databases of mutations, is expected to alter the structure of the protein and is therefore predicted to be probably damaging according to ACMG classification. In conclusion, we found a new likely pathogenic mutation in MEGF10, which is responsible for a progressive form of mvEMARDD with myofibrillar alterations at muscle biopsy. Interestingly, the presence of MEGF10 mutations has not been reported in Italian population. Early diagnosis of MEGF10 myopathy is essential in light of recent results from in vivo testing demonstrating a potential therapeutic effect of SSRIs compounds.
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Affiliation(s)
- Carolina Croci
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child (DINOGMI), University of Genoa, Genoa Italy
| | - Monica Traverso
- Paediatric Neurology and Neuromuscular Disorders Unit, IRCCS Istituto “G. Gaslini”, Genoa Italy
| | - Serena Baratto
- Paediatric Neurology and Neuromuscular Disorders Unit, IRCCS Istituto “G. Gaslini”, Genoa Italy
| | - Michele Iacomino
- Medical Genetics Unit, IRCCS Istituto “G. Gaslini”, Genoa, Italy
| | - Marina Pedemonte
- Paediatric Neurology and Neuromuscular Disorders Unit, IRCCS Istituto “G. Gaslini”, Genoa Italy
| | - Francesco Caroli
- Medical Genetics Unit, IRCCS Istituto “G. Gaslini”, Genoa, Italy
| | - Marcello Scala
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child (DINOGMI), University of Genoa, Genoa Italy
| | - Claudio Bruno
- Center of Translational and Experimental Myology, IRCCS Istituto “G. Gaslini”, Genoa, Ital
| | - Chiara Fiorillo
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child (DINOGMI), University of Genoa, Genoa Italy, Paediatric Neurology and Neuromuscular Disorders Unit, IRCCS Istituto “G. Gaslini”, Genoa Italy,Correspondence Chiara Fiorillo Paediatric Neurology and Neuromuscular Disorder Unit, IRCCS Istituto “G. Gaslini”, largo Gaslini 5, 16147 Genoa, Italy. Tel.: +39 010 56363566. E-mail:
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5
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Fague L, Liu YA, Marsh-Armstrong N. The basic science of optic nerve regeneration. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:1276. [PMID: 34532413 PMCID: PMC8421956 DOI: 10.21037/atm-20-5351] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 01/15/2021] [Indexed: 12/25/2022]
Abstract
Diverse insults to the optic nerve result in partial to total vision loss as the axons of retinal ganglion cells are destroyed. In glaucoma, axons are injured at the optic nerve head; in other optic neuropathies, axons can be damaged along the entire visual pathway. In all cases, as mammals cannot regenerate injured central nervous system cells, once the axons are lost, vision loss is irreversible. However, much has been learned about how retinal ganglion cells respond to axon injuries, and many of these crucial discoveries offer hope for future regenerative therapies. Here we review the current understanding regarding the temporal progression of axonal degeneration. We summarize known survival and regenerative mechanisms in mammals, including specific signaling pathways, key transcription factors, and reprogramming genes. We cover mechanisms intrinsic to retinal ganglion cells as well as their interactions with myeloid and glial cell populations in the retina and optic nerve that affect survival and regeneration. Finally, we highlight some non-mammalian species that are able to regenerate their retinal ganglion cell axons after injury, as understanding these successful regenerative responses may be essential to the rational design of future clinical interventions to regrow the optic nerve. In the end, a combination of many different molecular and cellular interventions will likely be the only way to achieve functional recovery of vision and restore quality of life to millions of patients around the world.
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Affiliation(s)
- Lindsay Fague
- UC Davis Eye Center, Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, CA, USA
| | - Yin Allison Liu
- UC Davis Eye Center, Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, CA, USA
| | - Nicholas Marsh-Armstrong
- UC Davis Eye Center, Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, CA, USA
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6
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Sadoun A, Biarnes-Pelicot M, Ghesquiere-Dierickx L, Wu A, Théodoly O, Limozin L, Hamon Y, Puech PH. Controlling T cells spreading, mechanics and activation by micropatterning. Sci Rep 2021; 11:6783. [PMID: 33762632 PMCID: PMC7991639 DOI: 10.1038/s41598-021-86133-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 03/02/2021] [Indexed: 01/31/2023] Open
Abstract
We designed a strategy, based on a careful examination of the activation capabilities of proteins and antibodies used as substrates for adhering T cells, coupled to protein microstamping to control at the same time the position, shape, spreading, mechanics and activation state of T cells. Once adhered on patterns, we examined the capacities of T cells to be activated with soluble anti CD3, in comparison to T cells adhered to a continuously decorated substrate with the same density of ligands. We show that, in our hand, adhering onto an anti CD45 antibody decorated surface was not affecting T cell calcium fluxes, even adhered on variable size micro-patterns. Aside, we analyzed the T cell mechanics, when spread on pattern or not, using Atomic Force Microscopy indentation. By expressing MEGF10 as a non immune adhesion receptor in T cells we measured the very same spreading area on PLL substrates and Young modulus than non modified cells, immobilized on anti CD45 antibodies, while retaining similar activation capabilities using soluble anti CD3 antibodies or through model APC contacts. We propose that our system is a way to test activation or anergy of T cells with defined adhesion and mechanical characteristics, and may allow to dissect fine details of these mechanisms since it allows to observe homogenized populations in standardized T cell activation assays.
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Affiliation(s)
- Anaïs Sadoun
- grid.5399.60000 0001 2176 4817Adhesion and Inflammation Lab (LAI), Aix Marseille University, LAI UM 61, 13288 Marseille, France ,grid.457381.cAdhesion and Inflammation Lab (LAI), Inserm, UMR_S 1067, 13288 Marseille, France ,grid.4444.00000 0001 2112 9282Adhesion and Inflammation Lab (LAI), CNRS, UMR 7333, 13288 Marseille, France ,grid.5399.60000 0001 2176 4817Centre d’Immunologie de Marseille Luminy (CIML), Aix-Marseille University, CNRS, Inserm, CIML Marseille, 13288 Marseille, France
| | - Martine Biarnes-Pelicot
- grid.5399.60000 0001 2176 4817Adhesion and Inflammation Lab (LAI), Aix Marseille University, LAI UM 61, 13288 Marseille, France ,grid.457381.cAdhesion and Inflammation Lab (LAI), Inserm, UMR_S 1067, 13288 Marseille, France ,grid.4444.00000 0001 2112 9282Adhesion and Inflammation Lab (LAI), CNRS, UMR 7333, 13288 Marseille, France
| | - Laura Ghesquiere-Dierickx
- grid.5399.60000 0001 2176 4817Adhesion and Inflammation Lab (LAI), Aix Marseille University, LAI UM 61, 13288 Marseille, France ,grid.457381.cAdhesion and Inflammation Lab (LAI), Inserm, UMR_S 1067, 13288 Marseille, France ,grid.4444.00000 0001 2112 9282Adhesion and Inflammation Lab (LAI), CNRS, UMR 7333, 13288 Marseille, France ,grid.7497.d0000 0004 0492 0584Present Address: Division of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Ambroise Wu
- grid.5399.60000 0001 2176 4817Centre d’Immunologie de Marseille Luminy (CIML), Aix-Marseille University, CNRS, Inserm, CIML Marseille, 13288 Marseille, France ,grid.8505.80000 0001 1010 5103Present Address: Department of Biophysics, University of Wrocław, Wrocław, Poland
| | - Olivier Théodoly
- grid.5399.60000 0001 2176 4817Adhesion and Inflammation Lab (LAI), Aix Marseille University, LAI UM 61, 13288 Marseille, France ,grid.457381.cAdhesion and Inflammation Lab (LAI), Inserm, UMR_S 1067, 13288 Marseille, France ,grid.4444.00000 0001 2112 9282Adhesion and Inflammation Lab (LAI), CNRS, UMR 7333, 13288 Marseille, France
| | - Laurent Limozin
- grid.5399.60000 0001 2176 4817Adhesion and Inflammation Lab (LAI), Aix Marseille University, LAI UM 61, 13288 Marseille, France ,grid.457381.cAdhesion and Inflammation Lab (LAI), Inserm, UMR_S 1067, 13288 Marseille, France ,grid.4444.00000 0001 2112 9282Adhesion and Inflammation Lab (LAI), CNRS, UMR 7333, 13288 Marseille, France
| | - Yannick Hamon
- grid.5399.60000 0001 2176 4817Centre d’Immunologie de Marseille Luminy (CIML), Aix-Marseille University, CNRS, Inserm, CIML Marseille, 13288 Marseille, France
| | - Pierre-Henri Puech
- grid.5399.60000 0001 2176 4817Adhesion and Inflammation Lab (LAI), Aix Marseille University, LAI UM 61, 13288 Marseille, France ,grid.457381.cAdhesion and Inflammation Lab (LAI), Inserm, UMR_S 1067, 13288 Marseille, France ,grid.4444.00000 0001 2112 9282Adhesion and Inflammation Lab (LAI), CNRS, UMR 7333, 13288 Marseille, France
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7
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Engulfment of Toxic Amyloid β-protein in Neurons and Astrocytes Mediated by MEGF10. Neuroscience 2020; 443:1-7. [PMID: 32682823 DOI: 10.1016/j.neuroscience.2020.07.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 06/30/2020] [Accepted: 07/10/2020] [Indexed: 11/20/2022]
Abstract
Amyloid-β proteins (A β), including Aβ42 and A β 43, are known pathogenesis factors of Alzheimer's disease (AD). Unwanted substances in the brain, including A β, are generally removed by microglia, astrocytes, or neurons via a phagocytosis receptor. We observed that neurons and astrocytes engulfed A β 42 and A β 43, which are more neurotoxic than A β 40. We previously showed that multiple-EGF like domains 10 (MEGF10) plays an important role in apoptotic cell elimination and is expressed in mammalian neurons and astrocytes. Therefore, we assessed whether MEGF10 is involved in A β42 and A β43 engulfment in MEGF10-expressing neurons and astrocytes. We found that MEGF10-expressing astrocytes and neurons engulfed A β42 and A β43 but not A β40. Furthermore, incubation of the neurons and astrocytes with A β42 and A β43a ugmented MEGF10 phosphorylation; however, incubation with A β40 did not have this augmenting effect. Our findings suggest that MEGF10 plays a phagocytosis receptor function for A β42 and A β43 in neurons and astrocytes.
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8
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Murshid A, Borges TJ, Bonorino C, Lang BJ, Calderwood SK. Immunological Outcomes Mediated Upon Binding of Heat Shock Proteins to Scavenger Receptors SCARF1 and LOX-1, and Endocytosis by Mononuclear Phagocytes. Front Immunol 2020; 10:3035. [PMID: 31998315 PMCID: PMC6968791 DOI: 10.3389/fimmu.2019.03035] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 12/11/2019] [Indexed: 01/06/2023] Open
Abstract
Heat shock proteins (HSP) are a highly abundant class of molecular chaperones that can be released into the extracellular milieu and influence the immune response. HSP release can occur when cells undergo necrosis and exude their contents. However, HSPs are also secreted from intact cells, either in free form or in lipid vesicles including exosomes to react with receptors on adjacent cells. Target cells are able recognize extracellular HSPs through cell surface receptors. These include scavenger receptors (SR) such as class E member oxidized low-density lipoprotein receptor-1 (LOX-1, aka OLR1, Clec8A, and SR-E1) and scavenger receptor class F member 1 (SCARF1, aka SREC1). Both receptors are expressed by dendritic cells (DC) and macrophages. These receptors can bind HSPs coupled to client binding proteins and deliver the chaperone substrate to the pathways of antigen processing in cells. SR are able to facilitate the delivery of client proteins to the proteasome, leading to antigen processing and presentation, and stimulation of adaptive immunity. HSPs may also may be involved in innate immunity through activation of inflammatory signaling pathways in a mechanism dependent on SR and toll-like receptor 4 (TLR4) on DC and macrophages. We will discuss the pathways by which HSPs can facilitate uptake of protein antigens and the receptors that regulate the ensuing immune response.
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Affiliation(s)
- Ayesha Murshid
- Department of Radiation Oncology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States
| | - Thiago J Borges
- Department of Radiation Oncology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States.,Renal Division, Schuster Family Transplantation Research Center, Harvard Medical School and Brigham and Women's Hospital, Boston, MA, United States
| | - Cristina Bonorino
- Laboratório de Immunoterapia, Departmento de Ciências Básicas da Saúde, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, Brazil.,Department of Surgery, School of Medicine, University of California, San Diego, San Diego, CA, United States
| | - Benjamin J Lang
- Department of Radiation Oncology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States
| | - Stuart K Calderwood
- Department of Radiation Oncology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States
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9
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Saha M, Mitsuhashi S, Jones MD, Manko K, Reddy HM, Bruels CC, Cho KA, Pacak CA, Draper I, Kang PB. Consequences of MEGF10 deficiency on myoblast function and Notch1 interactions. Hum Mol Genet 2018; 26:2984-3000. [PMID: 28498977 DOI: 10.1093/hmg/ddx189] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 05/08/2017] [Indexed: 01/22/2023] Open
Abstract
Mutations in MEGF10 cause early onset myopathy, areflexia, respiratory distress, and dysphagia (EMARDD), a rare congenital muscle disease, but the pathogenic mechanisms remain largely unknown. We demonstrate that short hairpin RNA (shRNA)-mediated knockdown of Megf10, as well as overexpression of the pathogenic human p.C774R mutation, leads to impaired proliferation and migration of C2C12 cells. Myoblasts from Megf10-/- mice and Megf10-/-/mdx double knockout (dko) mice also show impaired proliferation and migration compared to myoblasts from wild type and mdx mice, whereas the dko mice show histological abnormalities that are not observed in either single mutant mouse. Cell proliferation and migration are known to be regulated by the Notch receptor, which plays an essential role in myogenesis. Reciprocal co-immunoprecipitation studies show that Megf10 and Notch1 interact via their respective intracellular domains. These interactions are impaired by the pathogenic p.C774R mutation. Megf10 regulation of myoblast function appears to be mediated at least in part via interactions with key components of the Notch signaling pathway, and defects in these interactions may contribute to the pathogenesis of EMARDD.
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Affiliation(s)
- Madhurima Saha
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Satomi Mitsuhashi
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Michael D Jones
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Kelsey Manko
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Hemakumar M Reddy
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Christine C Bruels
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Kyung-Ah Cho
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA.,Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Christina A Pacak
- Child Health Research Institute, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Isabelle Draper
- Molecular Cardiology Research Institute, Department of Medicine, Tufts Medical Center, Boston, MA 02111, USA
| | - Peter B Kang
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA.,Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA.,Department of Neurology and Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL 32610, USA.,Genetics Institute and Myology Institute, University of Florida, Gainesville, FL 32610, USA
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10
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Fujita Y, Maeda T, Kamaishi K, Saito R, Chiba K, Shen X, Zou K, Komano H. Expression of MEGF10 in cholinergic and glutamatergic neurons. Neurosci Lett 2017; 653:25-30. [DOI: 10.1016/j.neulet.2017.05.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 05/09/2017] [Accepted: 05/15/2017] [Indexed: 02/04/2023]
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11
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Charlet J, Tomari A, Dallosso AR, Szemes M, Kaselova M, Curry TJ, Almutairi B, Etchevers HC, McConville C, Malik KTA, Brown KW. Genome-wide DNA methylation analysis identifies MEGF10 as a novel epigenetically repressed candidate tumor suppressor gene in neuroblastoma. Mol Carcinog 2016; 56:1290-1301. [PMID: 27862318 PMCID: PMC5396313 DOI: 10.1002/mc.22591] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 11/03/2016] [Accepted: 11/11/2016] [Indexed: 01/07/2023]
Abstract
Neuroblastoma is a childhood cancer in which many children still have poor outcomes, emphasising the need to better understand its pathogenesis. Despite recent genome‐wide mutation analyses, many primary neuroblastomas do not contain recognizable driver mutations, implicating alternate molecular pathologies such as epigenetic alterations. To discover genes that become epigenetically deregulated during neuroblastoma tumorigenesis, we took the novel approach of comparing neuroblastomas to neural crest precursor cells, using genome‐wide DNA methylation analysis. We identified 93 genes that were significantly differentially methylated of which 26 (28%) were hypermethylated and 67 (72%) were hypomethylated. Concentrating on hypermethylated genes to identify candidate tumor suppressor loci, we found the cell engulfment and adhesion factor gene MEGF10 to be epigenetically repressed by DNA hypermethylation or by H3K27/K9 methylation in neuroblastoma cell lines. MEGF10 showed significantly down‐regulated expression in neuroblastoma tumor samples; furthermore patients with the lowest‐expressing tumors had reduced relapse‐free survival. Our functional studies showed that knock‐down of MEGF10 expression in neuroblastoma cell lines promoted cell growth, consistent with MEGF10 acting as a clinically relevant, epigenetically deregulated neuroblastoma tumor suppressor gene. © 2016 The Authors. Molecular Carcinogenesis Published by Wiley Periodicals, Inc.
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Affiliation(s)
- Jessica Charlet
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| | - Ayumi Tomari
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| | - Anthony R Dallosso
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| | - Marianna Szemes
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| | - Martina Kaselova
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| | - Thomas J Curry
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| | - Bader Almutairi
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| | - Heather C Etchevers
- Faculté de Médecine, Aix-Marseille University, GMGF, UMR_S910, Marseille, France.,Faculté de Médecine, INSERM U910, Marseille, France
| | - Carmel McConville
- Institute of Cancer & Genomic Sciences, University of Birmingham, UK
| | - Karim T A Malik
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| | - Keith W Brown
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
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12
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Park SY, Yun Y, Kim MJ, Kim IS. Myogenin is a positive regulator of MEGF10 expression in skeletal muscle. Biochem Biophys Res Commun 2014; 450:1631-7. [PMID: 25044114 DOI: 10.1016/j.bbrc.2014.07.061] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 07/11/2014] [Indexed: 11/18/2022]
Abstract
MEGF10 is known to function as a myogenic regulator of satellite cells in skeletal muscle. Mutations in MEGF10 gene cause a congenital myopathy called early onset myopathy, areflexia, respiratory distress and dysphagia (EMARDD). Despite its biological importance in muscle physiology, transcriptional regulation of the MEGF10 gene is unknown. Here, we characterized the 5' flanking region of the human MEGF10 gene and showed that the role of myogenic basic helix-loop-helix factor (bHLH) myogenin in MEGF10 transcription in muscle cells. Myogenin was found to share a similar expression pattern with MEGF10 during muscle regeneration and to increase the promoter activity of the MEGF10 gene in C2C12 cells. Overexpression of myogenin led to upregulation of MEGF10 mRNA in C2C12 cells. Site-directed mutagenesis assays revealed that the conserved E-box element at the region -114/-108 serves as a myogenin-binding motif. Promoter enzyme immunoassays and chromatin immunoprecipitation analysis showed direct interaction between myogenin and the myogenin-binding motif in the MEGF10 promoter. Taken together, these results indicate that myogenin is a positive regulator in transcriptional regulation of MEGF10 in skeletal muscle.
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Affiliation(s)
- Seung-Yoon Park
- Department of Biochemistry, School of Medicine, Dongguk University, Gyeongju 780-714, Republic of Korea.
| | - Youngeun Yun
- Department of Biochemistry and Cell Biology, Cell and Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu 700-422, Republic of Korea
| | - Mi-Jin Kim
- Department of Biochemistry, School of Medicine, Dongguk University, Gyeongju 780-714, Republic of Korea
| | - In-San Kim
- Department of Biochemistry and Cell Biology, Cell and Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu 700-422, Republic of Korea; Biomedical Research Institute, Korea Institute Science and Technology, Seoul 136-791, Republic of Korea.
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13
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Estévez-Lao TY, Hillyer JF. Involvement of the Anopheles gambiae Nimrod gene family in mosquito immune responses. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2014; 44:12-22. [PMID: 24200842 DOI: 10.1016/j.ibmb.2013.10.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 10/23/2013] [Accepted: 10/25/2013] [Indexed: 06/02/2023]
Abstract
Insects fight infection using a variety of signaling pathways and immune effector proteins. In Drosophila melanogaster, three members of the Nimrod gene family (draper, nimC1 and eater) bind bacteria, and this binding leads to phagocytosis by hemocytes. The Nimrod gene family has since been identified in other insects, but their function in non-drosophilids remains unknown. The purpose of this study was to identify the members of the Nimrod gene family in the malaria mosquito, Anopheles gambiae, and to assess their role in immunity. We identified and sequenced three members of this gene family, herein named draper, nimrod and eater, which are the orthologs of D. melanogaster draper, nimB2 and eater, respectively. The three genes are preferentially expressed in hemocytes and their peak developmental expression is in pupae and young adults. Infection induces the transcriptional upregulation of all three genes, but the magnitude of this upregulation becomes more attenuated as mosquitoes become older. RNAi-based knockdown of eater, but not draper or nimrod, decreased a mosquito's ability to kill Escherichia coli in the hemocoel. Knockdown of draper, eater, or any combination of Nimrod family genes rendered mosquitoes more likely to die from Staphylococcus epidermidis. Finally, knockdown of Nimrod family genes did not impact mRNA levels of the antimicrobial peptides defensin (def1), cecropin (cecA) or gambicin (gam1), but eater knockdown led to a decrease in mRNA levels of nitric oxide synthase. Together, these data show that members of the A. gambiae Nimrod gene family are positive regulators of the mosquito antibacterial response.
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Affiliation(s)
- Tania Y Estévez-Lao
- Department of Biological Sciences, Vanderbilt University, VU Station B 35-1634, Nashville, TN 37235, USA
| | - Julián F Hillyer
- Department of Biological Sciences, Vanderbilt University, VU Station B 35-1634, Nashville, TN 37235, USA.
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14
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Kuhlwilm M, Davierwala A, Pääbo S. Identification of putative target genes of the transcription factor RUNX2. PLoS One 2013; 8:e83218. [PMID: 24349465 PMCID: PMC3861491 DOI: 10.1371/journal.pone.0083218] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 11/01/2013] [Indexed: 02/04/2023] Open
Abstract
Comparisons of the genomes of Neandertals and Denisovans with present-day human genomes have suggested that the gene RUNX2, which encodes a transcription factor, may have been positively selected during early human evolution. Here, we overexpress RUNX2 in ten human cell lines and identify genes that are directly or indirectly affected by RUNX2 expression. We find a number of genes not previously known to be affected by RUNX2 expression, in particular BIRC3, genes encoded on the mitochondrial genome, and several genes involved in bone and tooth formation. These genes are likely to provide inroads into pathways affected by RUNX2 and potentially by the evolutionary changes that affected RUNX2 in modern humans.
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Affiliation(s)
- Martin Kuhlwilm
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | | | - Svante Pääbo
- Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- * E-mail:
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15
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Mitsuhashi S, Mitsuhashi H, Alexander MS, Sugimoto H, Kang PB. Cysteine mutations cause defective tyrosine phosphorylation in MEGF10 myopathy. FEBS Lett 2013; 587:2952-7. [PMID: 23954233 DOI: 10.1016/j.febslet.2013.08.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 06/27/2013] [Accepted: 08/01/2013] [Indexed: 01/06/2023]
Abstract
Recessive mutations in MEGF10 are known to cause a congenital myopathy in humans. Two mutations in the extracellular EGF-like domains of MEGF10, C326R and C774R, were associated with decreased tyrosine phosphorylation of MEGF10 in vitro. Y1030 was identified to be the major tyrosine phosphorylation site in MEGF10 and is phosphorylated at least in part by c-Src. Overexpression of wild-type MEGF10 enhanced C2C12 myoblast proliferation, while overexpression of Y1030F mutated MEGF10 did not. We conclude that MEGF10-mediated signaling via tyrosine phosphorylation helps to regulate myoblast proliferation. Defects in this signaling pathway may contribute to the disease mechanism of MEGF10 myopathy.
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Affiliation(s)
- Satomi Mitsuhashi
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
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16
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Caprini A, Silva D, Zanoni I, Cunha C, Volontè C, Vescovi A, Gelain F. A novel bioactive peptide: assessing its activity over murine neural stem cells and its potential for neural tissue engineering. N Biotechnol 2013; 30:552-62. [PMID: 23541699 DOI: 10.1016/j.nbt.2013.03.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Revised: 02/11/2013] [Accepted: 03/18/2013] [Indexed: 01/16/2023]
Abstract
The design of biomimetic scaffolds suitable for cell-based therapies is a fundamental step for the regeneration of the damaged nervous system; indeed growing interest is focusing on the discovery of peptide sequences to modulate the fate of transplanted cells and, in particular, the differentiation outcome of multipotent neural stem cells. By applying the Phage Display technique to murine neural stem cells we isolated a peptide, KLPGWSG, present in proteins involved in both stem cell maintenance and differentiation. We show that KLPGWSG binds molecules expressed on the cell surface of murine adult neural stem cells, thus may potentially be involved in stem cell fate determination. Indeed we demonstrated that this peptide in solution enhances per se cell differentiation toward the neuronal phenotype. Hence, we synthesized two LDLK-12-based self-assembling peptides functionalized with KLPGWSG peptide (KLP and Ac-KLP) and characterized them via atomic force microscopy, rheometry and circular dichroism, obtaining nanostructured hydrogels supporting murine neural stem cells differentiation in vitro. Interestingly, we demonstrated that, when scaffold stiffness is comparable to that of the brain in vivo, the Ac-KLP SAP-based scaffold enhances the neuronal differentiation of neural stem cells. These evidences place both KLPGWSG and the functionalized self-assembling peptide Ac-KLP as promising candidates for, respectively, biomimetic studies and stem cell therapies for nervous regeneration.
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Affiliation(s)
- Andrea Caprini
- Center for Nanomedicine and Tissue Engineering, A.O. Ospedale Niguarda Ca' Granda, Milan 20162, Italy
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17
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Bröhl D, Vasyutina E, Czajkowski M, Griger J, Rassek C, Rahn HP, Purfürst B, Wende H, Birchmeier C. Colonization of the Satellite Cell Niche by Skeletal Muscle Progenitor Cells Depends on Notch Signals. Dev Cell 2012; 23:469-81. [DOI: 10.1016/j.devcel.2012.07.014] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 06/19/2012] [Accepted: 07/17/2012] [Indexed: 10/28/2022]
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18
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Lööv C, Hillered L, Ebendal T, Erlandsson A. Engulfing astrocytes protect neurons from contact-induced apoptosis following injury. PLoS One 2012; 7:e33090. [PMID: 22461890 PMCID: PMC3312890 DOI: 10.1371/journal.pone.0033090] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Accepted: 02/03/2012] [Indexed: 12/12/2022] Open
Abstract
Clearing of dead cells is a fundamental process to limit tissue damage following brain injury. Engulfment has classically been believed to be performed by professional phagocytes, but recent data show that non-professional phagocytes are highly involved in the removal of cell corpses in various situations. The role of astrocytes in cell clearance following trauma has however not been studied in detail. We have found that astrocytes actively collect and engulf whole dead cells in an in vitro model of brain injury and thereby protect healthy neurons from bystander cell death. Time-lapse experiments showed that migrating neurons that come in contact with free-floating cell corpses induced apoptosis, while neurons that migrate through groups of dead cells, garnered by astrocytes, remain unaffected. Furthermore, apoptotic cells are present within astrocytes in the mouse brain following traumatic brain injury (TBI), indicating a possible role for astrocytes in engulfment of apoptotic cells in vivo. qRT-PCR analysis showed that members of both ced pathways and Megf8 are expressed in the cell culture, indicating their possible involvement in astrocytic engulfment. Moreover, addition of dead cells had a positive effect on the protein expression of MEGF10, an ortholog to CED1, known to initiate phagocytosis by binding to phosphatidylserine. Although cultured astrocytes have an immense capacity for engulfment, seemingly without adverse effects, the ingested material is stored rather than degraded. This finding might explain the multinuclear astrocytes that are found at the lesion site in patients with various brain disorders.
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Affiliation(s)
| | | | | | - Anna Erlandsson
- Department of Neuroscience, Uppsala University, Uppsala, Sweden
- * E-mail:
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19
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MEGF10 and MEGF11 mediate homotypic interactions required for mosaic spacing of retinal neurons. Nature 2012; 483:465-9. [PMID: 22407321 PMCID: PMC3310952 DOI: 10.1038/nature10877] [Citation(s) in RCA: 134] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2011] [Accepted: 01/17/2012] [Indexed: 02/01/2023]
Abstract
In many parts of the nervous system, neuronal somata display orderly spatial arrangements1. In the retina, neurons of numerous individual subtypes form regular arrays called mosaics: they are less likely to be near neighbors of the same subtype than would occur by chance, resulting in “exclusion zones” that separate them1-4. Mosaic arrangements provide a mechanism to distribute each cell type evenly across the retina, ensuring that all parts of the visual field have access to a full set of processing elements2. Remarkably, mosaics are independent of each other: while a neuron of one subtype is unlikely to be adjacent to another of the same subtype, there is no restriction on its spatial relationship to neighboring neurons of other subtypes5. This independence has led to the hypothesis that molecular cues expressed by specific subtypes pattern mosaics by mediating homotypic (within-subtype) short-range repulsive interactions1,4-9. To date, however, no molecules have been identified that show such activity, so this hypothesis remains untested. Here, we demonstrate that two related transmembrane proteins, MEGF10 and MEGF11, play critical roles in formation of mosaics by two retinal interneuron subtypes, starburst amacrine cells (SACs) and horizontal cells (HCs). MEGF10/11 and their invertebrate relatives C. elegans CED-1 and Drosophila Draper, have hitherto been studied primarily as receptors necessary for engulfment of debris following apoptosis or axonal injury10-14. Our results demonstrate that members of this gene family can also serve as subtype-specific ligands that pattern neuronal arrays.
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20
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Jha A, Watkins SC, Traub LM. The apoptotic engulfment protein Ced-6 participates in clathrin-mediated yolk uptake in Drosophila egg chambers. Mol Biol Cell 2012; 23:1742-64. [PMID: 22398720 PMCID: PMC3338440 DOI: 10.1091/mbc.e11-11-0939] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
During oogenesis in Drosophila, the phagocytic engulfment protein Ced-6 recognizes the atypical endocytic sorting signal within the vitellogenin receptor Yolkless. Because Ced-6 displays all of the features of an authentic clathrin adaptor, an unrecognized clathrin dependence for Ced-6/Gulp operation during phagocytosis is possible. Clathrin-mediated endocytosis and phagocytosis are both selective surface internalization processes but have little known mechanistic similarity or interdependence. Here we show that the phosphotyrosine-binding (PTB) domain protein Ced-6, a well-established phagocytosis component that operates as a transducer of so-called “eat-me” signals during engulfment of apoptotic cells and microorganisms, is expressed in the female Drosophila germline and that Ced-6 expression correlates with ovarian follicle development. Ced-6 exhibits all the known biochemical properties of a clathrin-associated sorting protein, yet ced-6–null flies are semifertile despite massive accumulation of soluble yolk precursors in the hemolymph. This is because redundant sorting signals within the cytosolic domain of the Drosophila vitellogenin receptor Yolkless, a low density lipoprotein receptor superfamily member, occur; a functional atypical dileucine signal binds to the endocytic AP-2 clathrin adaptor directly. Nonetheless, the Ced-6 PTB domain specifically recognizes the noncanonical Yolkless FXNPXA sorting sequence and in HeLa cells promotes the rapid, clathrin-dependent uptake of a Yolkless chimera lacking the distal dileucine signal. Ced-6 thus operates in vivo as a clathrin adaptor. Because the human Ced-6 orthologue GULP similarly binds to clathrin machinery, localizes to cell surface clathrin-coated structures, and is enriched in placental clathrin-coated vesicles, new possibilities for Ced-6/Gulp operation during phagocytosis must be considered.
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Affiliation(s)
- Anupma Jha
- Department of Cell Biology and Physiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
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21
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Boyden SE, Mahoney LJ, Kawahara G, Myers JA, Mitsuhashi S, Estrella EA, Duncan AR, Dey F, DeChene ET, Blasko-Goehringer JM, Bönnemann CG, Darras BT, Mendell JR, Lidov HGW, Nishino I, Beggs AH, Kunkel LM, Kang PB. Mutations in the satellite cell gene MEGF10 cause a recessive congenital myopathy with minicores. Neurogenetics 2012; 13:115-24. [PMID: 22371254 PMCID: PMC3332380 DOI: 10.1007/s10048-012-0315-z] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Accepted: 01/25/2012] [Indexed: 02/04/2023]
Abstract
We ascertained a nuclear family in which three of four siblings were affected with an unclassified autosomal recessive myopathy characterized by severe weakness, respiratory impairment, scoliosis, joint contractures, and an unusual combination of dystrophic and myopathic features on muscle biopsy. Whole genome sequence from one affected subject was filtered using linkage data and variant databases. A single gene, MEGF10, contained nonsynonymous mutations that co-segregated with the phenotype. Affected subjects were compound heterozygous for missense mutations c.976T > C (p.C326R) and c.2320T > C (p.C774R). Screening the MEGF10 open reading frame in 190 patients with genetically unexplained myopathies revealed a heterozygous mutation, c.211C > T (p.R71W), in one additional subject with a similar clinical and histological presentation as the discovery family. All three mutations were absent from at least 645 genotyped unaffected control subjects. MEGF10 contains 17 atypical epidermal growth factor-like domains, each of which contains eight cysteine residues that likely form disulfide bonds. Both the p.C326R and p.C774R mutations alter one of these residues, which are completely conserved in vertebrates. Previous work showed that murine Megf10 is required for preserving the undifferentiated, proliferative potential of satellite cells, myogenic precursors that regenerate skeletal muscle in response to injury or disease. Here, knockdown of megf10 in zebrafish by four different morpholinos resulted in abnormal phenotypes including unhatched eggs, curved tails, impaired motility, and disorganized muscle tissue, corroborating the pathogenicity of the human mutations. Our data establish the importance of MEGF10 in human skeletal muscle and suggest satellite cell dysfunction as a novel myopathic mechanism.
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Affiliation(s)
- Steven E. Boyden
- Division of Genetics, Program in Genomics, and The Manton Center for Orphan Disease Research, Children’s Hospital Boston, Boston, MA USA
- Department of Genetics, Harvard Medical School, Boston, MA USA
| | - Lane J. Mahoney
- Division of Genetics, Program in Genomics, and The Manton Center for Orphan Disease Research, Children’s Hospital Boston, Boston, MA USA
| | - Genri Kawahara
- Division of Genetics, Program in Genomics, and The Manton Center for Orphan Disease Research, Children’s Hospital Boston, Boston, MA USA
| | - Jennifer A. Myers
- Division of Genetics, Program in Genomics, and The Manton Center for Orphan Disease Research, Children’s Hospital Boston, Boston, MA USA
| | - Satomi Mitsuhashi
- Division of Genetics, Program in Genomics, and The Manton Center for Orphan Disease Research, Children’s Hospital Boston, Boston, MA USA
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Elicia A. Estrella
- Division of Genetics, Program in Genomics, and The Manton Center for Orphan Disease Research, Children’s Hospital Boston, Boston, MA USA
| | - Anna R. Duncan
- Division of Genetics, Program in Genomics, and The Manton Center for Orphan Disease Research, Children’s Hospital Boston, Boston, MA USA
| | - Friederike Dey
- Division of Genetics, Program in Genomics, and The Manton Center for Orphan Disease Research, Children’s Hospital Boston, Boston, MA USA
| | - Elizabeth T. DeChene
- Division of Genetics, Program in Genomics, and The Manton Center for Orphan Disease Research, Children’s Hospital Boston, Boston, MA USA
| | - Jessica M. Blasko-Goehringer
- Division of Genetics, Program in Genomics, and The Manton Center for Orphan Disease Research, Children’s Hospital Boston, Boston, MA USA
| | - Carsten G. Bönnemann
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD USA
| | - Basil T. Darras
- Department of Neurology, Children’s Hospital Boston and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115 USA
| | - Jerry R. Mendell
- Center for Gene Therapy Research Institute, Nationwide Children’s Hospital, Columbus, OH USA
| | - Hart G. W. Lidov
- Division of Genetics, Program in Genomics, and The Manton Center for Orphan Disease Research, Children’s Hospital Boston, Boston, MA USA
- Department of Pathology, Children’s Hospital Boston and Harvard Medical School, Boston, MA USA
| | - Ichizo Nishino
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Alan H. Beggs
- Division of Genetics, Program in Genomics, and The Manton Center for Orphan Disease Research, Children’s Hospital Boston, Boston, MA USA
- Department of Pediatrics, Harvard Medical School, Boston, MA USA
| | - Louis M. Kunkel
- Division of Genetics, Program in Genomics, and The Manton Center for Orphan Disease Research, Children’s Hospital Boston, Boston, MA USA
- Department of Genetics, Harvard Medical School, Boston, MA USA
- Department of Pediatrics, Harvard Medical School, Boston, MA USA
| | - Peter B. Kang
- Division of Genetics, Program in Genomics, and The Manton Center for Orphan Disease Research, Children’s Hospital Boston, Boston, MA USA
- Department of Neurology, Children’s Hospital Boston and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115 USA
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22
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Murshid A, Gong J, Stevenson MA, Calderwood SK. Heat shock proteins and cancer vaccines: developments in the past decade and chaperoning in the decade to come. Expert Rev Vaccines 2012; 10:1553-68. [PMID: 22043955 DOI: 10.1586/erv.11.124] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Molecular chaperone-peptide complexes extracted from tumors (heat shock protein [HSP] vaccines) have been intensively studied in the preceding two decades, proving to be safe and effective in treating a number of malignant diseases. They offer personalized therapy and target a cross-section of antigens expressed in patients' tumors. Future advances may rely on understanding the molecular underpinnings of this approach to immunotherapy. One property common to HSP vaccines is the ability to stimulate antigen uptake by scavenger receptors on the antigen-presenting cell surface and trigger T-lymphocyte activation. HSPs can also induce signaling through Toll-Like receptors in a range of immune cells and this may mediate the effectiveness of vaccines.
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Affiliation(s)
- Ayesha Murshid
- Molecular and Cellular Radiation Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, 99 Brookline Avenue, Boston, MA 02215, USA
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23
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Logan CV, Lucke B, Pottinger C, Abdelhamed ZA, Parry DA, Szymanska K, Diggle CP, van Riesen A, Morgan JE, Markham G, Ellis I, Manzur AY, Markham AF, Shires M, Helliwell T, Scoto M, Hübner C, Bonthron DT, Taylor GR, Sheridan E, Muntoni F, Carr IM, Schuelke M, Johnson CA. Mutations in MEGF10, a regulator of satellite cell myogenesis, cause early onset myopathy, areflexia, respiratory distress and dysphagia (EMARDD). Nat Genet 2011; 43:1189-92. [PMID: 22101682 DOI: 10.1038/ng.995] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Accepted: 10/05/2011] [Indexed: 02/08/2023]
Abstract
Infantile myopathies with diaphragmatic paralysis are genetically heterogeneous, and clinical symptoms do not assist in differentiating between them. We used phased haplotype analysis with subsequent targeted exome sequencing to identify MEGF10 mutations in a previously unidentified type of infantile myopathy with diaphragmatic weakness, areflexia, respiratory distress and dysphagia. MEGF10 is highly expressed in activated satellite cells and regulates their proliferation as well as their differentiation and fusion into multinucleated myofibers, which are greatly reduced in muscle from individuals with early onset myopathy, areflexia, respiratory distress and dysphagia.
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Affiliation(s)
- Clare V Logan
- Leeds Institute of Molecular Medicine, The University of Leeds, UK
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24
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Ding VMY, Boersema PJ, Foong LY, Preisinger C, Koh G, Natarajan S, Lee DY, Boekhorst J, Snel B, Lemeer S, Heck AJR, Choo A. Tyrosine phosphorylation profiling in FGF-2 stimulated human embryonic stem cells. PLoS One 2011; 6:e17538. [PMID: 21437283 PMCID: PMC3060089 DOI: 10.1371/journal.pone.0017538] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Accepted: 02/08/2011] [Indexed: 01/05/2023] Open
Abstract
The role of fibroblast growth factor-2 (FGF-2) in maintaining undifferentiated human embryonic stem cells (hESC) was investigated using a targeted phosphoproteomics approach to specifically profile tyrosine phosphorylation events following FGF-2 stimulation. A cumulative total number of 735 unique tyrosine phosphorylation sites on 430 proteins were identified, by far the largest inventory to date for hESC. Early signaling events in FGF-2 stimulated hESC were quantitatively monitored using stable isotope dimethyl labeling, resulting in temporal tyrosine phosphorylation profiles of 316 unique phosphotyrosine peptides originating from 188 proteins. Apart from the rapid activation of all four FGF receptors, trans-activation of several other receptor tyrosine kinases (RTKs) was observed as well as induced tyrosine phosphorylation of downstream proteins such as PI3-K, MAPK and several Src family members. Both PI3-K and MAPK have been linked to hESC maintenance through FGF-2 mediated signaling. The observed activation of the Src kinase family members by FGF-2 and loss of pluripotent marker expression post Src kinase inhibition may point to the regulation of cytoskeletal and actin depending processes to maintain undifferentiated hESC.
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Affiliation(s)
- Vanessa M. Y. Ding
- Stem Cell Group, Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
- Centre for Life Sciences (CeLS), NUS Graduate School for Integrative Sciences and Engineering (NGS), Singapore, Singapore
| | - Paul J. Boersema
- Biomolecular Mass Spectrometry and Proteomics Group, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands
- Netherlands Proteomics Centre, Utrecht, The Netherlands
| | - Leong Yan Foong
- Stem Cell Group, Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Christian Preisinger
- Biomolecular Mass Spectrometry and Proteomics Group, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands
- Netherlands Proteomics Centre, Utrecht, The Netherlands
| | - Geoffrey Koh
- Stem Cell Group, Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Subaashini Natarajan
- Stem Cell Group, Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Dong-Yup Lee
- Stem Cell Group, Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
- Centre for Life Sciences (CeLS), NUS Graduate School for Integrative Sciences and Engineering (NGS), Singapore, Singapore
| | - Jos Boekhorst
- Bioinformatics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Berend Snel
- Bioinformatics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Simone Lemeer
- Biomolecular Mass Spectrometry and Proteomics Group, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands
- Netherlands Proteomics Centre, Utrecht, The Netherlands
| | - Albert J. R. Heck
- Biomolecular Mass Spectrometry and Proteomics Group, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands
- Netherlands Proteomics Centre, Utrecht, The Netherlands
- Centre for Biomedical Genetics, Utrecht, The Netherlands
- * E-mail: (AC); (AJRH)
| | - Andre Choo
- Stem Cell Group, Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
- Bioinformatics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
- Division of Bioengineering, Faculty of Engineering, National University of Singapore, Singapore, Singapore
- * E-mail: (AC); (AJRH)
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Singh TD, Park SY, Bae JS, Yun Y, Bae YC, Park RW, Kim IS. MEGF10 functions as a receptor for the uptake of amyloid-β. FEBS Lett 2010; 584:3936-42. [DOI: 10.1016/j.febslet.2010.08.050] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Revised: 07/31/2010] [Accepted: 08/30/2010] [Indexed: 10/19/2022]
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Park SY, Kim SY, Kang KB, Kim IS. Adaptor protein GULP is involved in stabilin-1-mediated phagocytosis. Biochem Biophys Res Commun 2010; 398:467-72. [PMID: 20599701 DOI: 10.1016/j.bbrc.2010.06.101] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2010] [Accepted: 06/23/2010] [Indexed: 10/19/2022]
Abstract
The clearance of apoptotic cells is critical during cellular homeostasis as well as inflammation resolution. Recently, we found that stabilin-1 is a phagocytic receptor that is involved in the clearance of apoptotic cells. However, the downstream signaling pathway of stabilin-1-mediated phagocytosis remains to be investigated. Here we identify that GULP is able to specifically interact with the NPxF/Y motif of stabilin-1 cytoplasmic region. The PTB domain of GULP is necessary for interaction with stabilin-1. GULP is enriched around PS-coated beads for phagocytosis and co-localized with stabilin-1. Downregulation of endogenous GULP expression decreased stabilin-1-mediated phagocytosis. Thus, these results indicate that GULP functions as an adaptor protein for stabilin-1-mediated phagocytosis.
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Affiliation(s)
- Seung-Yoon Park
- Department of Biochemistry, School of Medicine, Dongguk University, Gyeongju 780-714, Republic of Korea
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27
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Wu HH, Bellmunt E, Scheib JL, Venegas V, Burkert C, Reichardt LF, Zhou Z, Fariñas I, Carter BD. Glial precursors clear sensory neuron corpses during development via Jedi-1, an engulfment receptor. Nat Neurosci 2009; 12:1534-41. [PMID: 19915564 PMCID: PMC2834222 DOI: 10.1038/nn.2446] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2009] [Accepted: 10/07/2009] [Indexed: 12/14/2022]
Abstract
During the development of peripheral ganglia, 50% of the neurons that are generated undergo apoptosis. How the massive numbers of corpses are removed is unknown. We found that satellite glial cell precursors are the primary phagocytic cells for apoptotic corpse removal in developing mouse dorsal root ganglia (DRG). Confocal and electron microscopic analysis revealed that glial precursors, rather than macrophages, were responsible for clearing most of the dead DRG neurons. Moreover, we identified Jedi-1, an engulfment receptor, and MEGF10, a purported engulfment receptor, as homologs of the invertebrate engulfment receptors Draper and CED-1 expressed in the glial precursor cells. Expression of Jedi-1 or MEGF10 in fibroblasts facilitated binding to dead neurons, and knocking down either protein in glial cells or overexpressing truncated forms lacking the intracellular domain inhibited engulfment of apoptotic neurons. Together, these results suggest a cellular and molecular mechanism by which neuronal corpses are culled during DRG development.
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Affiliation(s)
- Hsiao-Huei Wu
- The Center for Molecular Neuroscience, Kennedy Center For Human Development, and Department of Biochemistry, Vanderbilt University Medical School, Nashville, Tennessee, USA
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28
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Chen X, Sun C, Chen Q, O'Neill FA, Walsh D, Fanous AH, Chowdari KV, Nimgaonkar VL, Scott A, Schwab SG, Wildenauer DB, Che R, Tang W, Shi Y, He L, Luo XJ, Su B, Edwards TL, Zhao Z, Kendler KS. Apoptotic engulfment pathway and schizophrenia. PLoS One 2009; 4:e6875. [PMID: 19721717 PMCID: PMC2731162 DOI: 10.1371/journal.pone.0006875] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2009] [Accepted: 07/14/2009] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Apoptosis has been speculated to be involved in schizophrenia. In a previously study, we reported the association of the MEGF10 gene with the disease. In this study, we followed the apoptotic engulfment pathway involving the MEGF10, GULP1, ABCA1 and ABCA7 genes and tested their association with the disease. METHODOLOGY/PRINCIPAL FINDINGS Ten, eleven and five SNPs were genotyped in the GULP1, ABCA1 and ABCA7 genes respectively for the ISHDSF and ICCSS samples. In all 3 genes, we observed nominally significant associations. Rs2004888 at GULP1 was significant in both ISHDSF and ICCSS samples (p = 0.0083 and 0.0437 respectively). We sought replication in independent samples for this marker and found highly significant association (p = 0.0003) in 3 Caucasian replication samples. But it was not significant in the 2 Chinese replication samples. In addition, we found a significant 2-marker (rs2242436 * rs3858075) interaction between the ABCA1 and ABCA7 genes in the ISHDSF sample (p = 0.0022) and a 3-marker interaction (rs246896 * rs4522565 * rs3858075) amongst the MEGF10, GULP1 and ABCA1 genes in the ICCSS sample (p = 0.0120). Rs3858075 in the ABCA1 gene was involved in both 2- and 3-marker interactions in the two samples. CONCLUSIONS/SIGNIFICANCE From these data, we concluded that the GULP1 gene and the apoptotic engulfment pathway are involved in schizophrenia in subjects of European ancestry and multiple genes in the pathway may interactively increase the risks to the disease.
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Affiliation(s)
- Xiangning Chen
- Department of Psychiatry and Virginia Institute for Psychiatric and Behavior Genetics, Virginia Commonwealth University, Richmond, Virginia, USA.
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Park SY, Kang KB, Thapa N, Kim SY, Lee SJ, Kim IS. Requirement of adaptor protein GULP during stabilin-2-mediated cell corpse engulfment. J Biol Chem 2008; 283:10593-600. [PMID: 18230608 DOI: 10.1074/jbc.m709105200] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The prompt clearance of cells undergoing apoptosis is critical during embryonic development and normal tissue turnover, as well as during inflammation and autoimmune responses. We recently demonstrated that stabilin-2 is a phosphatidylserine receptor that mediates the clearance of apoptotic cells, thereby releasing the anti-inflammatory cytokine, transforming growth factor-beta. However, the downstream signaling components of stabilin-2-mediated phagocytosis are not known. Here, we provide evidence that the adaptor protein, GULP, physically and functionally interacts with the stabilin-2 cytoplasmic tail. Using fluorescent resonance energy transfer analysis and biochemical approaches, we show that GULP directly binds to the cytoplasmic tail of stabilin-2. Knockdown of endogenous GULP expression significantly decreased stabilin-2-mediated phagocytosis. Conversely, overexpression of GULP caused an increase in aged cell engulfment. The phosphotyrosine binding (PTB) domain of GULP was sufficient for the interaction with stabilin-2; therefore, transduction of TAT fusion PTB domain acts as a dominant negative, resulting in impaired engulfment of aged red blood cells in stabilin-2 expressing cells. In addition, the PTB domain of GULP was able to specifically interact with the NPXY motif of the stabilin-2 cytoplasmic tail. Taken together, these results indicate that GULP is a likely downstream molecule in the stabilin-2-mediated signaling pathway and plays an important role in stabilin-2-mediated phagocytosis.
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Affiliation(s)
- Seung-Yoon Park
- Department of Biochemistry and Cell Biology, Cell and Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu, 700-422, Korea
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