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Groden M, Moessinger HM, Schaffran B, DeFelipe J, Benavides-Piccione R, Cuntz H, Jedlicka P. A biologically inspired repair mechanism for neuronal reconstructions with a focus on human dendrites. PLoS Comput Biol 2024; 20:e1011267. [PMID: 38394339 PMCID: PMC10917450 DOI: 10.1371/journal.pcbi.1011267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 03/06/2024] [Accepted: 02/02/2024] [Indexed: 02/25/2024] Open
Abstract
Investigating and modelling the functionality of human neurons remains challenging due to the technical limitations, resulting in scarce and incomplete 3D anatomical reconstructions. Here we used a morphological modelling approach based on optimal wiring to repair the parts of a dendritic morphology that were lost due to incomplete tissue samples. In Drosophila, where dendritic regrowth has been studied experimentally using laser ablation, we found that modelling the regrowth reproduced a bimodal distribution between regeneration of cut branches and invasion by neighbouring branches. Interestingly, our repair model followed growth rules similar to those for the generation of a new dendritic tree. To generalise the repair algorithm from Drosophila to mammalian neurons, we artificially sectioned reconstructed dendrites from mouse and human hippocampal pyramidal cell morphologies, and showed that the regrown dendrites were morphologically similar to the original ones. Furthermore, we were able to restore their electrophysiological functionality, as evidenced by the recovery of their firing behaviour. Importantly, we show that such repairs also apply to other neuron types including hippocampal granule cells and cerebellar Purkinje cells. We then extrapolated the repair to incomplete human CA1 pyramidal neurons, where the anatomical boundaries of the particular brain areas innervated by the neurons in question were known. Interestingly, the repair of incomplete human dendrites helped to simulate the recently observed increased synaptic thresholds for dendritic NMDA spikes in human versus mouse dendrites. To make the repair tool available to the neuroscience community, we have developed an intuitive and simple graphical user interface (GUI), which is available in the TREES toolbox (www.treestoolbox.org).
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Affiliation(s)
- Moritz Groden
- 3R Computer-Based Modelling, Faculty of Medicine, ICAR3R, Justus Liebig University Giessen, Giessen, Germany
| | - Hannah M. Moessinger
- Ernst Strüngmann Institute (ESI) for Neuroscience in cooperation with the Max Planck Society, Frankfurt am Main, Germany
| | - Barbara Schaffran
- Ernst Strüngmann Institute (ESI) for Neuroscience in cooperation with the Max Planck Society, Frankfurt am Main, Germany
- Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Javier DeFelipe
- Laboratorio Cajal de Circuitos Corticales (CTB), Universidad Politécnica de Madrid, Spain
- Instituto Cajal (CSIC), Madrid, Spain
| | - Ruth Benavides-Piccione
- Laboratorio Cajal de Circuitos Corticales (CTB), Universidad Politécnica de Madrid, Spain
- Instituto Cajal (CSIC), Madrid, Spain
| | - Hermann Cuntz
- 3R Computer-Based Modelling, Faculty of Medicine, ICAR3R, Justus Liebig University Giessen, Giessen, Germany
- Ernst Strüngmann Institute (ESI) for Neuroscience in cooperation with the Max Planck Society, Frankfurt am Main, Germany
- Frankfurt Institute for Advanced Studies, Frankfurt am Main, Germany
| | - Peter Jedlicka
- 3R Computer-Based Modelling, Faculty of Medicine, ICAR3R, Justus Liebig University Giessen, Giessen, Germany
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University, Frankfurt am Main, Germany
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2
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Lemma B, Nelson CM. Spatial patterning of energy metabolism during tissue morphogenesis. Curr Opin Cell Biol 2023; 85:102235. [PMID: 37696131 PMCID: PMC10840784 DOI: 10.1016/j.ceb.2023.102235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Revised: 08/12/2023] [Accepted: 08/13/2023] [Indexed: 09/13/2023]
Abstract
Biophysical signaling organizes forces to drive tissue morphogenesis, a process co-opted during disease progression. The systematic buildup of forces at the tissue scale is energetically demanding. Just as mechanical forces, gene expression, and concentrations of morphogens vary spatially across a developing tissue, there might similarly be spatial variations in energy consumption. Recent studies have started to uncover the connections between spatial patterns of mechanical forces and spatial patterns of energy metabolism. Here, we define and review the concept of energy metabolism during tissue morphogenesis. We highlight experiments showing spatial variations in energy metabolism across several model systems, categorized by morphogenetic motif, including convergent extension, branching, and migration. Finally, we discuss approaches to further enable quantitative measurements of energy production and consumption during morphogenesis.
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Affiliation(s)
- Bezia Lemma
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Celeste M Nelson
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
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3
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Liao M, Bird AD, Cuntz H, Howard J. Topology recapitulates morphogenesis of neuronal dendrites. Cell Rep 2023; 42:113268. [PMID: 38007691 PMCID: PMC10756852 DOI: 10.1016/j.celrep.2023.113268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 08/01/2023] [Accepted: 09/28/2023] [Indexed: 11/27/2023] Open
Abstract
Branching allows neurons to make synaptic contacts with large numbers of other neurons, facilitating the high connectivity of nervous systems. Neuronal arbors have geometric properties such as branch lengths and diameters that are optimal in that they maximize signaling speeds while minimizing construction costs. In this work, we asked whether neuronal arbors have topological properties that may also optimize their growth or function. We discovered that for a wide range of invertebrate and vertebrate neurons the distributions of their subtree sizes follow power laws, implying that they are scale invariant. The power-law exponent distinguishes different neuronal cell types. Postsynaptic spines and branchlets perturb scale invariance. Through simulations, we show that the subtree-size distribution depends on the symmetry of the branching rules governing arbor growth and that optimal morphologies are scale invariant. Thus, the subtree-size distribution is a topological property that recapitulates the functional morphology of dendrites.
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Affiliation(s)
- Maijia Liao
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06520, USA
| | - Alex D Bird
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, 60528 Frankfurt am Main, Germany; ICAR3R-Interdisciplinary Centre for 3Rs in Animal Research, Faculty of Medicine, Justus Liebig University, 35390 Giessen, Germany
| | - Hermann Cuntz
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, 60528 Frankfurt am Main, Germany; ICAR3R-Interdisciplinary Centre for 3Rs in Animal Research, Faculty of Medicine, Justus Liebig University, 35390 Giessen, Germany
| | - Jonathon Howard
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06520, USA.
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4
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Desai-Chowdhry P, Brummer AB, Mallavarapu S, Savage VM. Neuronal branching is increasingly asymmetric near synapses, potentially enabling plasticity while minimizing energy dissipation and conduction time. J R Soc Interface 2023; 20:20230265. [PMID: 37669695 PMCID: PMC10480011 DOI: 10.1098/rsif.2023.0265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 08/15/2023] [Indexed: 09/07/2023] Open
Abstract
Neurons' primary function is to encode and transmit information in the brain and body. The branching architecture of axons and dendrites must compute, respond and make decisions while obeying the rules of the substrate in which they are enmeshed. Thus, it is important to delineate and understand the principles that govern these branching patterns. Here, we present evidence that asymmetric branching is a key factor in understanding the functional properties of neurons. First, we derive novel predictions for asymmetric scaling exponents that encapsulate branching architecture associated with crucial principles such as conduction time, power minimization and material costs. We compare our predictions with extensive data extracted from images to associate specific principles with specific biophysical functions and cell types. Notably, we find that asymmetric branching models lead to predictions and empirical findings that correspond to different weightings of the importance of maximum, minimum or total path lengths from the soma to the synapses. These different path lengths quantitatively and qualitatively affect energy, time and materials. Moreover, we generally observe that higher degrees of asymmetric branching-potentially arising from extrinsic environmental cues and synaptic plasticity in response to activity-occur closer to the tips than the soma (cell body).
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Affiliation(s)
- Paheli Desai-Chowdhry
- Department of Computational Medicine, University of California Los Angeles, Los Angeles, CA, USA
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
| | | | - Samhita Mallavarapu
- Department of Computational Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Van M. Savage
- Department of Computational Medicine, University of California Los Angeles, Los Angeles, CA, USA
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, CA, USA
- Santa Fe Institute, Santa Fe, NM, USA
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5
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Desai-Chowdhry P, Brummer AB, Mallavarapu S, Savage VM. Neuronal Branching is Increasingly Asymmetric Near Synapses, Potentially Enabling Plasticity While Minimizing Energy Dissipation and Conduction Time. bioRxiv 2023:2023.05.20.541591. [PMID: 37292687 PMCID: PMC10245708 DOI: 10.1101/2023.05.20.541591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Neurons' primary function is to encode and transmit information in the brain and body. The branching architecture of axons and dendrites must compute, respond, and make decisions while obeying the rules of the substrate in which they are enmeshed. Thus, it is important to delineate and understand the principles that govern these branching patterns. Here, we present evidence that asymmetric branching is a key factor in understanding the functional properties of neurons. First, we derive novel predictions for asymmetric scaling exponents that encapsulate branching architecture associated with crucial principles such as conduction time, power minimization, and material costs. We compare our predictions with extensive data extracted from images to associate specific principles with specific biophysical functions and cell types. Notably, we find that asymmetric branching models lead to predictions and empirical findings that correspond to different weightings of the importance of maximum, minimum, or total path lengths from the soma to the synapses. These different path lengths quantitatively and qualitatively affect energy, time, and materials. Moreover, we generally observe that higher degrees of asymmetric branching- potentially arising from extrinsic environmental cues and synaptic plasticity in response to activity- occur closer to the tips than the soma (cell body).
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6
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Lin C, Xu F, Zhang Y. Brain-wide dendrites in a near-optimal performance of dynamic range and information transmission. Sci Rep 2023; 13:7488. [PMID: 37160938 PMCID: PMC10170161 DOI: 10.1038/s41598-023-34454-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Accepted: 04/30/2023] [Indexed: 05/11/2023] Open
Abstract
Dendrites receive and process signals from other neurons. The range of signal intensities that can be robustly distinguished by dendrites is quantified by the dynamic range. We investigate the dynamic range and information transmission efficiency of dendrites in relation to dendritic morphology. We model dendrites in a neuron as multiple excitable binary trees connected to the soma where each node in a tree can be excited by external stimulus or by receiving signals transmitted from adjacent excited nodes. It has been known that larger dendritic trees have a higher dynamic range. We show that for dendritic tress of the same number of nodes, the dynamic range increases with the number of somatic branches and decreases with the asymmetry of dendrites, and the information transmission is more efficient for dendrites with more somatic branches. Moreover, our simulated data suggest that there is an exponential association (decay resp.) of overall relative energy consumption (dynamic range resp.) in relation to the number of somatic branches. This indicates that further increasing the number of somatic branches (e.g. beyond 10 somatic branches) has limited ability to improve the transmission efficiency. With brain-wide neuron digital reconstructions of the pyramidal cells, 90% of neurons have no more than 10 dendrites. These suggest that actual brain-wide dendritic morphology is near optimal in terms of both dynamic range and information transmission.
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Affiliation(s)
- Congping Lin
- School of Mathematics and Statistics and Center for Mathematical Sciences, Huazhong University of Science and Technology, Wuhan, China
- Hubei Key Lab of Engineering Modeling and Scientific Computing, Huazhong University of Science and Technology, Wuhan, China
| | - Fan Xu
- School of Mathematics and Statistics and Center for Mathematical Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Yiwei Zhang
- Department of Mathematics, Southern University of Science and Technology, Shenzhen, Guangdong, China.
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7
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Haufler D, Ito S, Koch C, Arkhipov A. Simulations of cortical networks using spatially extended conductance-based neuronal models. J Physiol 2022. [PMID: 36567262 PMCID: PMC10290729 DOI: 10.1113/jp284030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 12/19/2022] [Indexed: 12/27/2022] Open
Abstract
The Hodgkin-Huxley model of action potential generation and propagation, published in the Journal of Physiology in 1952, initiated the field of biophysically detailed computational modelling in neuroscience, which has expanded to encompass a variety of species and components of the nervous system. Here we review the developments in this area with a focus on efforts in the community towards modelling the mammalian neocortex using spatially extended conductance-based neuronal models. The Hodgkin-Huxley formalism and related foundational contributions, such as Rall's cable theory, remain widely used in these efforts to the current day. We argue that at present the field is undergoing a qualitative change due to new very rich datasets describing the composition, connectivity and functional activity of cortical circuits, which are being integrated systematically into large-scale network models. This trend, combined with the accelerating development of convenient software tools supporting such complex modelling projects, is giving rise to highly detailed models of the cortex that are extensively constrained by the data, enabling computational investigation of a multitude of questions about cortical structure and function.
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Affiliation(s)
- Darrell Haufler
- Mindscope Program, Allen Institute, Seattle, Washington, USA
| | - Shinya Ito
- Mindscope Program, Allen Institute, Seattle, Washington, USA
| | - Christof Koch
- Mindscope Program, Allen Institute, Seattle, Washington, USA
| | - Anton Arkhipov
- Mindscope Program, Allen Institute, Seattle, Washington, USA
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8
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Desai-Chowdhry P, Brummer AB, Savage VM. How axon and dendrite branching are guided by time, energy, and spatial constraints. Sci Rep 2022; 12:20810. [PMID: 36460669 DOI: 10.1038/s41598-022-24813-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 11/21/2022] [Indexed: 12/05/2022] Open
Abstract
Neurons are connected by complex branching processes-axons and dendrites-that process information for organisms to respond to their environment. Classifying neurons according to differences in structure or function is a fundamental part of neuroscience. Here, by constructing biophysical theory and testing against empirical measures of branching structure, we develop a general model that establishes a correspondence between neuron structure and function as mediated by principles such as time or power minimization for information processing as well as spatial constraints for forming connections. We test our predictions for radius scale factors against those extracted from neuronal images, measured for species that range from insects to whales, including data from light and electron microscopy studies. Notably, our findings reveal that the branching of axons and peripheral nervous system neurons is mainly determined by time minimization, while dendritic branching is determined by power minimization. Our model also predicts a quarter-power scaling relationship between conduction time delay and body size.
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9
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Shree S, Sutradhar S, Trottier O, Tu Y, Liang X, Howard J. Dynamic instability of dendrite tips generates the highly branched morphologies of sensory neurons. Sci Adv 2022; 8:eabn0080. [PMID: 35767611 PMCID: PMC9242452 DOI: 10.1126/sciadv.abn0080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 05/12/2022] [Indexed: 06/15/2023]
Abstract
The highly ramified arbors of neuronal dendrites provide the substrate for the high connectivity and computational power of the brain. Altered dendritic morphology is associated with neuronal diseases. Many molecules have been shown to play crucial roles in shaping and maintaining dendrite morphology. However, the underlying principles by which molecular interactions generate branched morphologies are not understood. To elucidate these principles, we visualized the growth of dendrites throughout larval development of Drosophila sensory neurons and found that the tips of dendrites undergo dynamic instability, transitioning rapidly and stochastically between growing, shrinking, and paused states. By incorporating these measured dynamics into an agent-based computational model, we showed that the complex and highly variable dendritic morphologies of these cells are a consequence of the stochastic dynamics of their dendrite tips. These principles may generalize to branching of other neuronal cell types, as well as to branching at the subcellular and tissue levels.
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Affiliation(s)
- Sonal Shree
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
| | - Sabyasachi Sutradhar
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
| | - Olivier Trottier
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
- Department of Physics, Yale University, New Haven, CT 06511, USA
| | - Yuhai Tu
- IBM T.J. Watson Research Center, Yorktown Heights, NY 10598, USA
| | - Xin Liang
- Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, 100084 Beijing, China
| | - Jonathon Howard
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
- Department of Physics, Yale University, New Haven, CT 06511, USA
- Quantitative Biology Institute, Yale University, New Haven, CT 06511, USA
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10
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Liao M, Kuo YW, Howard J. Counting fluorescently labeled proteins in tissues in the spinning disk microscope using single-molecule calibrations. Mol Biol Cell 2022; 33:ar48. [PMID: 35323029 PMCID: PMC9265152 DOI: 10.1091/mbc.e21-12-0618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Quantification of molecular numbers and concentrations in living cells is critical for testing models of complex biological phenomena. Counting molecules in cells requires estimation of the fluorescence intensity of single molecules, which is generally limited to imaging near cell surfaces, in isolated cells, or where motions are diffusive. To circumvent this difficulty, we have devised a calibration technique for spinning–disk confocal microscopy, commonly used for imaging in tissues, that uses single–step bleaching kinetics to estimate the single–fluorophore intensity. To cross–check our calibrations, we compared the brightness of fluorophores in the SDC microscope to those in the total internal reflection and epifluorescence microscopes. We applied this calibration method to quantify the number of end–binding protein 1 (EB1)–eGFP in the comets of growing microtubule ends and to measure the cytoplasmic concentration of EB1–eGFP in sensory neurons in fly larvae. These measurements allowed us to estimate the dissociation constant of EB1–eGFP from the microtubules as well as the GTP–tubulin cap size. Our results show the unexplored potential of single–molecule imaging using spinning–disk confocal microscopy and provide a straightforward method to count the absolute number of fluorophores in tissues that can be applied to a wide range of biological systems and imaging techniques.
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Affiliation(s)
- Maijia Liao
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Yin-Wei Kuo
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Jonathon Howard
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
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11
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Abstract
Transport of intracellular components relies on a variety of active and passive mechanisms, ranging from the diffusive spreading of small molecules over short distances to motor-driven motion across long distances. The cell-scale behavior of these mechanisms is fundamentally dependent on the morphology of the underlying cellular structures. Diffusion-limited reaction times can be qualitatively altered by the presence of occluding barriers or by confinement in complex architectures, such as those of reticulated organelles. Motor-driven transport is modulated by the architecture of cytoskeletal filaments that serve as transport highways. In this review, we discuss the impact of geometry on intracellular transport processes that fulfill a broad range of functional objectives, including delivery, distribution, and sorting of cellular components. By unraveling the interplay between morphology and transport efficiency, we aim to elucidate key structure-function relationships that govern the architecture of transport systems at the cellular scale. Expected final online publication date for the Annual Review of Biophysics, Volume 51 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Anamika Agrawal
- Department of Physics, University of California, San Diego, La Jolla, California, USA;
| | - Zubenelgenubi C Scott
- Department of Physics, University of California, San Diego, La Jolla, California, USA;
| | - Elena F Koslover
- Department of Physics, University of California, San Diego, La Jolla, California, USA;
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12
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Lannom MC, Nielsen J, Nawaz A, Shilikbay T, Ceman S. FMRP and MOV10 regulate Dicer1 expression and dendrite development. PLoS One 2021; 16:e0260005. [PMID: 34847178 PMCID: PMC8631628 DOI: 10.1371/journal.pone.0260005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 11/01/2021] [Indexed: 11/18/2022] Open
Abstract
Fragile X syndrome results from the loss of expression of the Fragile X Mental Retardation Protein (FMRP). FMRP and RNA helicase Moloney Leukemia virus 10 (MOV10) are important Argonaute (AGO) cofactors for miRNA-mediated translation regulation. We previously showed that MOV10 functionally associates with FMRP. Here we quantify the effect of reduced MOV10 and FMRP expression on dendritic morphology. Murine neurons with reduced MOV10 and FMRP phenocopied Dicer1 KO neurons which exhibit impaired dendritic maturation Hong J (2013), leading us to hypothesize that MOV10 and FMRP regulate DICER expression. In cells and tissues expressing reduced MOV10 or no FMRP, DICER expression was significantly reduced. Moreover, the Dicer1 mRNA is a Cross-Linking Immunoprecipitation (CLIP) target of FMRP Darnell JC (2011), MOV10 Skariah G (2017) and AGO2 Kenny PJ (2020). MOV10 and FMRP modulate expression of DICER1 mRNA through its 3’untranslated region (UTR) and introduction of a DICER1 transgene restores normal neurite outgrowth in the Mov10 KO neuroblastoma Neuro2A cell line and branching in MOV10 heterozygote neurons. Moreover, we observe a global reduction in AGO2-associated microRNAs isolated from Fmr1 KO brain. We conclude that the MOV10-FMRP-AGO2 complex regulates DICER expression, revealing a novel mechanism for regulation of miRNA production required for normal neuronal morphology.
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Affiliation(s)
- Monica C. Lannom
- Cell and Developmental Biology, University of Illinois, Urbana, Illinois, United States of America
| | - Joshua Nielsen
- Integrative Biology, University of Illinois, Urbana, Illinois, United States of America
| | - Aatiqa Nawaz
- Cell and Developmental Biology, University of Illinois, Urbana, Illinois, United States of America
| | - Temirlan Shilikbay
- Cell and Developmental Biology, University of Illinois, Urbana, Illinois, United States of America
| | - Stephanie Ceman
- Cell and Developmental Biology, University of Illinois, Urbana, Illinois, United States of America
- Neuroscience Program, University of Illinois, Urbana, Illinois, United States of America
- * E-mail:
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13
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Uçar MC, Kamenev D, Sunadome K, Fachet D, Lallemend F, Adameyko I, Hadjab S, Hannezo E. Theory of branching morphogenesis by local interactions and global guidance. Nat Commun 2021; 12:6830. [PMID: 34819507 PMCID: PMC8613190 DOI: 10.1038/s41467-021-27135-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 11/03/2021] [Indexed: 12/14/2022] Open
Abstract
Branching morphogenesis governs the formation of many organs such as lung, kidney, and the neurovascular system. Many studies have explored system-specific molecular and cellular regulatory mechanisms, as well as self-organizing rules underlying branching morphogenesis. However, in addition to local cues, branched tissue growth can also be influenced by global guidance. Here, we develop a theoretical framework for a stochastic self-organized branching process in the presence of external cues. Combining analytical theory with numerical simulations, we predict differential signatures of global vs. local regulatory mechanisms on the branching pattern, such as angle distributions, domain size, and space-filling efficiency. We find that branch alignment follows a generic scaling law determined by the strength of global guidance, while local interactions influence the tissue density but not its overall territory. Finally, using zebrafish innervation as a model system, we test these key features of the model experimentally. Our work thus provides quantitative predictions to disentangle the role of different types of cues in shaping branched structures across scales.
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Affiliation(s)
- Mehmet Can Uçar
- Institute of Science and Technology Austria, Am Campus 1, 3400, Klosterneuburg, Austria.
| | - Dmitrii Kamenev
- Department of Neuroscience, Karolinska Institutet, 17177, Stockholm, Sweden
| | - Kazunori Sunadome
- Department of Physiology and Pharmacology, Karolinska Institutet, 17177, Stockholm, Sweden
| | - Dominik Fachet
- Institute of Science and Technology Austria, Am Campus 1, 3400, Klosterneuburg, Austria
- IRI Life Sciences, Humboldt-Universität zu Berlin, 10115, Berlin, Germany
| | - Francois Lallemend
- Department of Neuroscience, Karolinska Institutet, 17177, Stockholm, Sweden
- Ming-Wai Lau Centre for Reparative Medicine, Stockholm node, Karolinska Institutet, Stockholm, Sweden
| | - Igor Adameyko
- Department of Physiology and Pharmacology, Karolinska Institutet, 17177, Stockholm, Sweden
- Department of Neuroimmunology, Center for Brain Research, Medical University of Vienna, 1090, Vienna, Austria
| | - Saida Hadjab
- Department of Neuroscience, Karolinska Institutet, 17177, Stockholm, Sweden.
| | - Edouard Hannezo
- Institute of Science and Technology Austria, Am Campus 1, 3400, Klosterneuburg, Austria.
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