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Vemula SK, Malci A, Junge L, Lehmann AC, Rama R, Hradsky J, Matute RA, Weber A, Prigge M, Naumann M, Kreutz MR, Seidenbecher CI, Gundelfinger ED, Herrera-Molina R. The Interaction of TRAF6 With Neuroplastin Promotes Spinogenesis During Early Neuronal Development. Front Cell Dev Biol 2020; 8:579513. [PMID: 33363141 PMCID: PMC7755605 DOI: 10.3389/fcell.2020.579513] [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: 07/02/2020] [Accepted: 11/11/2020] [Indexed: 11/22/2022] Open
Abstract
Correct brain wiring depends on reliable synapse formation. Nevertheless, signaling codes promoting synaptogenesis are not fully understood. Here, we report a spinogenic mechanism that operates during neuronal development and is based on the interaction of tumor necrosis factor receptor-associated factor 6 (TRAF6) with the synaptic cell adhesion molecule neuroplastin. The interaction between these proteins was predicted in silico and verified by co-immunoprecipitation in extracts from rat brain and co-transfected HEK cells. Binding assays show physical interaction between neuroplastin’s C-terminus and the TRAF-C domain of TRAF6 with a Kd value of 88 μM. As the two proteins co-localize in primordial dendritic protrusions, we used young cultures of rat and mouse as well as neuroplastin-deficient mouse neurons and showed with mutagenesis, knock-down, and pharmacological blockade that TRAF6 is required by neuroplastin to promote early spinogenesis during in vitro days 6-9, but not later. Time-framed TRAF6 blockade during days 6–9 reduced mEPSC amplitude, number of postsynaptic sites, synapse density and neuronal activity as neurons mature. Our data unravel a new molecular liaison that may emerge during a specific window of the neuronal development to determine excitatory synapse density in the rodent brain.
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Affiliation(s)
- Sampath Kumar Vemula
- Laboratory of Synaptic Signaling, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Ayse Malci
- Laboratory of Synaptic Signaling, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Lennart Junge
- Laboratory of Synaptic Signaling, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Anne-Christin Lehmann
- Laboratory of Synaptic Signaling, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Ramya Rama
- Laboratory of Synaptic Signaling, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Johannes Hradsky
- Laboratory of Synaptic Signaling, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Ricardo A Matute
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, United States.,Centro Integrativo de Biología y Química Aplicada, Universidad Bernardo O'Higgins, Santiago, Chile
| | - André Weber
- Laboratory of Synaptic Signaling, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Matthias Prigge
- Laboratory of Synaptic Signaling, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Michael Naumann
- Institute of Experimental Internal Medicine, Medical Faculty, Otto von Guericke University, Magdeburg, Germany
| | - Michael R Kreutz
- Laboratory of Synaptic Signaling, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany.,Leibniz Group 'Dendritic Organelles and Synaptic Function', Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Constanze I Seidenbecher
- Laboratory of Synaptic Signaling, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Eckart D Gundelfinger
- Laboratory of Synaptic Signaling, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany.,Medical Faculty, Otto von Guericke University, Magdeburg, Germany
| | - Rodrigo Herrera-Molina
- Laboratory of Synaptic Signaling, Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany.,Centro Integrativo de Biología y Química Aplicada, Universidad Bernardo O'Higgins, Santiago, Chile.,Center for Behavioral Brain Sciences, Magdeburg, Germany
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Tárnok K, Gulyás M, Bencsik N, Ferenc K, Pfizenmaier K, Hausser A, Schlett K. A new tool for the quantitative analysis of dendritic filopodial motility. Cytometry A 2014; 87:89-96. [PMID: 25257846 DOI: 10.1002/cyto.a.22569] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 08/05/2014] [Accepted: 09/01/2014] [Indexed: 02/02/2023]
Abstract
Dendritic filopodia are tiny and highly motile protrusions formed along the dendrites of neurons. During the search for future presynaptic partners, their shape and size change dynamically, with a direct impact on the formation, stabilization and maintenance of synaptic connections both in vivo and in vitro. In order to reveal molecular players regulating synapse formation, quantitative analysis of dendritic filopodia motility is needed. Defining the length or the tips of these protrusions manually, however, is time consuming, limiting the extent of studies as well as their statistical power. Additionally, area detection based on defining a single intensity threshold can lead to significant errors throughout the image series, as these small structures often have low contrast in fluorescent images. To overcome these problems, the open access Dendritic Filopodia Motility Analyzer, a semi-automated ImageJ/Fiji plugin was created. Our method calculates the displacement of the centre of mass (CoM) within a selected region based on the weighted intensity values of structure forming pixels, selected by upper and lower intensity thresholds. Using synthetic and real biological samples, we prove that the displacement of the weighted CoM reliably characterizes the motility of dendritic protrusions. Additionally, guidelines to define optimal parameters of live cell recordings from dendritic protrusions are provided. © 2014 International Society for Advancement of Cytometry.
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Affiliation(s)
- Krisztián Tárnok
- Department of Physiology and Neurobiology, Eötvös Loránd University, Pázmány P. stny. 1/C, H-1117, Budapest, Hungary
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Lohmann C, Wong ROL. Regulation of dendritic growth and plasticity by local and global calcium dynamics. Cell Calcium 2005; 37:403-9. [PMID: 15820387 DOI: 10.1016/j.ceca.2005.01.008] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2004] [Accepted: 01/06/2005] [Indexed: 11/26/2022]
Abstract
The dendritic arbors of neurons are organized into unique spatial patterns that are well suited for their specific functions. Although the intracellular signaling pathways that determine dendritic arbor size and branching patterns during development are not completely understood, it is evident that neurotransmission-mediated elevation in intracellular calcium levels ([Ca2+]i) plays a major role. Recent advances in calcium imaging and genetic approaches have provided new insight into how calcium acts to regulate dendritic growth and remodeling. Global increases in [Ca2+]i that occur upon neuronal depolarization control dendritic arbor growth by regulating transcription. However, the detailed branching patterns of dendritic arbors are regulated by local calcium signaling. Calcium-induced calcium release (CICR) from intracellular stores acts to locally stabilize dendritic branches, presumably triggered by neurotransmission upon contact with newly established inputs. The effects of global and local increases in [Ca2+]i on dendritic structure are cell type- and age-dependent. Unraveling the signaling pathways evoked by local and global rises in [Ca2+]i that shape the developing dendritic arbor at each developmental stage remains challenging but highly important.
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Affiliation(s)
- Christian Lohmann
- Max-Planck Institute of Neurobiology, Am Klopferspitz 18, 82152 Planegg-Martinsried, Germany.
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Lohmann C, Finski A, Bonhoeffer T. Local calcium transients regulate the spontaneous motility of dendritic filopodia. Nat Neurosci 2005; 8:305-12. [PMID: 15711541 DOI: 10.1038/nn1406] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2004] [Accepted: 01/19/2005] [Indexed: 11/09/2022]
Abstract
During development, dendrites, and in particular dendritic filopodia, undergo extensive structural remodeling, presumably to help establish synaptic contacts. Here, we investigated the role of calcium signaling in dendritic plasticity by simultaneously recording calcium dynamics and filopodial growth in rat hippocampal slice cultures. Local calcium transients occurred in dendritic filopodia and shafts, often at putative synaptic sites. These events were highly correlated with filopodial motility: comparatively rare when individual filopodia emerged from the dendrite, they became more frequent after filopodia started growing, finally causing them to halt. Accordingly, an experimental reduction of the frequency of local calcium transients elicited filopodial growth and, conversely, calcium uncaging reduced filopodial motility. Our observations suggest that low levels of local calcium transients facilitate filopodial outgrowth, whereas high levels inhibit the formation of filopodia and stabilize newly formed ones. This process may facilitate synapse formation and may serve as a homeostatic mechanism distributing synapses evenly along developing dendrites.
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Affiliation(s)
- Christian Lohmann
- Max Planck Institute of Neurobiology, Am Klopferspitz 18, 82152 Planegg-Martinsried, Germany.
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