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Schlissel G, Meziane M, Narducci D, Hansen AS, Li P. Diffusion barriers imposed by tissue topology shape Hedgehog morphogen gradients. Proc Natl Acad Sci U S A 2024; 121:e2400677121. [PMID: 39190357 PMCID: PMC11388384 DOI: 10.1073/pnas.2400677121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 07/15/2024] [Indexed: 08/28/2024] Open
Abstract
Animals use a small number of morphogens to pattern tissues, but it is unclear how evolution modulates morphogen signaling range to match tissues of varying sizes. Here, we used single-molecule imaging in reconstituted morphogen gradients and in tissue explants to determine that Hedgehog diffused extracellularly as a monomer, and rapidly transitioned between membrane-confined and -unconfined states. Unexpectedly, the vertebrate-specific protein SCUBE1 expanded Hedgehog gradients by accelerating the transition rates between states without affecting the relative abundance of molecules in each state. This observation could not be explained under existing models of morphogen diffusion. Instead, we developed a topology-limited diffusion model in which cell-cell gaps create diffusion barriers, which morphogens can only overcome by passing through a membrane-unconfined state. Under this model, SCUBE1 promoted Hedgehog secretion and diffusion by allowing it to transiently overcome diffusion barriers. This multiscale understanding of morphogen gradient formation unified prior models and identified knobs that nature can use to tune morphogen gradient sizes across tissues and organisms.
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Affiliation(s)
- Gavin Schlissel
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142
| | - Miram Meziane
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Domenic Narducci
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
- Gene Regulation Observatory, The Broad Institute of MIT and Harvard, Cambridge, MA 02142
- Koch Institute for Integrative Cancer Research, Cambridge, MA 02139
| | - Anders S Hansen
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
- Gene Regulation Observatory, The Broad Institute of MIT and Harvard, Cambridge, MA 02142
- Koch Institute for Integrative Cancer Research, Cambridge, MA 02139
| | - Pulin Li
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139
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Schlissel G, Meziane M, Narducci D, Hansen AS, Li P. Diffusion barriers imposed by tissue topology shape morphogen gradients. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.01.592050. [PMID: 38746265 PMCID: PMC11092646 DOI: 10.1101/2024.05.01.592050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Animals use a small number of morphogens to pattern tissues, but it is unclear how evolution modulates morphogen signaling range to match tissues of varying sizes. Here, we used single molecule imaging in reconstituted morphogen gradients and in tissue explants to determine that Hedgehog diffused extra-cellularly as a monomer, and rapidly transitioned between membrane-confined and -unconfined states. Unexpectedly, the vertebrate-specific protein SCUBE1 expanded Hedgehog gradients by accelerating the transition rates between states without affecting the relative abundance of molecules in each state. This observation could not be explained under existing models of morphogen diffusion. Instead, we developed a topology-limited diffusion model in which cell-cell gaps create diffusion barriers, and morphogens can only overcome the barrier by passing through a membrane-unconfined state. Under this model, SCUBE1 promotes Hedgehog secretion and diffusion by allowing it to transiently overcome diffusion barriers. This multiscale understanding of morphogen gradient formation unified prior models and discovered novel knobs that nature can use to tune morphogen gradient sizes across tissues and organisms.
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3
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Ripamonti U, Duarte R. Mechanistic insights into the spontaneous induction of bone formation. BIOMATERIALS ADVANCES 2024; 158:213795. [PMID: 38335762 DOI: 10.1016/j.bioadv.2024.213795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 12/19/2023] [Accepted: 02/01/2024] [Indexed: 02/12/2024]
Abstract
The grand discovery of morphogens, or "form-generating substances", revealed that tissue morphogenesis is initiated by soluble molecular signals or morphogens primarily belonging to the transforming growth factor-β (TGF-β) supergene family. The regenerative potential of bone rests on its extracellular matrix, which is the repository of several morphogens that tightly control cellular differentiating pathways, cellular matrix deposition and remodeling. Alluringly, the matrix also contains specific factors transferred from the heterotopic implanted bone matrices initiating "Tissue Induction", as provocatively described in Nature in 1945. Later, it was found that selected genes and gene products of the TGF-β supergene family singly, synchronously, and synergistically mastermind the induction of bone formation. This review describes the phenomenon of the spontaneous and/or intrinsic osteoinductivity of calcium phosphate-based biomaterials and titanium' constructs without the applications of soluble osteogenetic molecular signals. The review shows the spontaneous induction of bone formation initiated by Ca++ activating stem cell differentiation and up-regulation of bone morphogenetic proteins genes. Expressed gene products are embedded into the concavities of the calcium phosphate-based substrata, initiating bone formation as a secondary response. Pure titanium's substrata do not initiate the spontaneous induction of bone formation. The induction of bone is solely dependent on acid, alkali and heat treatments to form apatite layers on the treated titanium surfaces. The induction of bone formation is achieved exclusively by apatite-based biomaterial surfaces. The hydroxyapatite, in its various forms and geometric configurations, finely tunes the induction of bone formation in heterotopic sites. Cellular differentiation by fine-tuning of the cellular molecular machinery is initiated by specific geometric modularity of the hydroxyapatite substrata that push cellular buttons that start the ripple-like cascade of "Tissue Induction", generating newly formed ossicles with bone marrow in heterotopic extraskeletal sites. The highlighted mechanistic insights into the spontaneous induction of bone formation are a research platform invocating selected molecular elements to construct the induction of bone formation.
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Affiliation(s)
- Ugo Ripamonti
- Bone Research Laboratory, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
| | - Raquel Duarte
- Bone Research Laboratory, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Internal Medicine Research Laboratory, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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Kubota R, Hamachi I. Cell-Like Synthetic Supramolecular Soft Materials Realized in Multicomponent, Non-/Out-of-Equilibrium Dynamic Systems. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2306830. [PMID: 38018341 PMCID: PMC10885657 DOI: 10.1002/advs.202306830] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 10/30/2023] [Indexed: 11/30/2023]
Abstract
Living cells are complex, nonequilibrium supramolecular systems capable of independently and/or cooperatively integrating multiple bio-supramolecules to execute intricate physiological functions that cannot be accomplished by individual biomolecules. These biological design strategies offer valuable insights for the development of synthetic supramolecular systems with spatially controlled hierarchical structures, which, importantly, exhibit cell-like responses and functions. The next grand challenge in supramolecular chemistry is to control the organization of multiple types of supramolecules in a single system, thus integrating the functions of these supramolecules in an orthogonal and/or cooperative manner. In this perspective, the recent progress in constructing multicomponent supramolecular soft materials through the hybridization of supramolecules, such as self-assembled nanofibers/gels and coacervates, with other functional molecules, including polymer gels and enzymes is highlighted. Moreover, results show that these materials exhibit bioinspired responses to stimuli, such as bidirectional rheological responses of supramolecular double-network hydrogels, temporal stimulus pattern-dependent responses of synthetic coacervates, and 3D hydrogel patterning in response to reaction-diffusion processes are presented. Autonomous active soft materials with cell-like responses and spatially controlled structures hold promise for diverse applications, including soft robotics with directional motion, point-of-care disease diagnosis, and tissue regeneration.
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Affiliation(s)
- Ryou Kubota
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto, 615-8510, Japan
| | - Itaru Hamachi
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto, 615-8510, Japan
- JST-ERATO, Hamachi Innovative Molecular Technology for Neuroscience, Kyoto University, Nishikyo-ku, Katsura, 615-8530, Japan
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Kaneko K, Liang Y, Liu Q, Zhang S, Scheiter A, Song D, Feng GS. Identification of CD133 + intercellsomes in intercellular communication to offset intracellular signal deficit. eLife 2023; 12:RP86824. [PMID: 37846866 PMCID: PMC10581692 DOI: 10.7554/elife.86824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2023] Open
Abstract
CD133 (prominin 1) is widely viewed as a cancer stem cell marker in association with drug resistance and cancer recurrence. Herein, we report that with impaired RTK-Shp2-Ras-Erk signaling, heterogenous hepatocytes form clusters that manage to divide during mouse liver regeneration. These hepatocytes are characterized by upregulated CD133 while negative for other progenitor cell markers. Pharmaceutical inhibition of proliferative signaling also induced CD133 expression in various cancer cell types from multiple animal species, suggesting an inherent and common mechanism of stress response. Super-resolution and electron microscopy localize CD133 on intracellular vesicles that apparently migrate between cells, which we name 'intercellsome.' Isolated CD133+ intercellsomes are enriched with mRNAs rather than miRNAs. Single-cell RNA sequencing reveals lower intracellular diversity (entropy) of mitogenic mRNAs in Shp2-deficient cells, which may be remedied by intercellular mRNA exchanges between CD133+ cells. CD133-deficient cells are more sensitive to proliferative signal inhibition in livers and intestinal organoids. These data suggest a mechanism of intercellular communication to compensate for intracellular signal deficit in various cell types.
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Affiliation(s)
- Kota Kaneko
- Department of Pathology, Department of Molecular Biology, and Moores Cancer Center, University of California at San DiegoLa JollaUnited States
| | - Yan Liang
- Department of Pathology, Department of Molecular Biology, and Moores Cancer Center, University of California at San DiegoLa JollaUnited States
| | - Qing Liu
- Department of Pathology, Department of Molecular Biology, and Moores Cancer Center, University of California at San DiegoLa JollaUnited States
| | - Shuo Zhang
- Department of Pathology, Department of Molecular Biology, and Moores Cancer Center, University of California at San DiegoLa JollaUnited States
| | - Alexander Scheiter
- Department of Pathology, Department of Molecular Biology, and Moores Cancer Center, University of California at San DiegoLa JollaUnited States
- Institute of Pathology, University of RegensburgRegensburgGermany
| | - Dan Song
- Department of Pathology, Department of Molecular Biology, and Moores Cancer Center, University of California at San DiegoLa JollaUnited States
| | - Gen-Sheng Feng
- Department of Pathology, Department of Molecular Biology, and Moores Cancer Center, University of California at San DiegoLa JollaUnited States
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Hanly JJ, Loh LS, Mazo-Vargas A, Rivera-Miranda TS, Livraghi L, Tendolkar A, Day CR, Liutikaite N, Earls EA, Corning OBWH, D'Souza N, Hermina-Perez JJ, Mehta C, Ainsworth JA, Rossi M, Papa R, McMillan WO, Perry MW, Martin A. Frizzled2 receives WntA signaling during butterfly wing pattern formation. Development 2023; 150:dev201868. [PMID: 37602496 PMCID: PMC10560568 DOI: 10.1242/dev.201868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 08/04/2023] [Indexed: 08/22/2023]
Abstract
Butterfly color patterns provide visible and biodiverse phenotypic readouts of the patterning processes. Although the secreted ligand WntA has been shown to instruct the color pattern formation in butterflies, its mode of reception remains elusive. Butterfly genomes encode four homologs of the Frizzled-family of Wnt receptors. Here, we show that CRISPR mosaic knockouts of frizzled2 (fz2) phenocopy the color pattern effects of WntA loss of function in multiple nymphalids. Whereas WntA mosaic clones result in intermediate patterns of reduced size, fz2 clones are cell-autonomous, consistent with a morphogen function. Shifts in expression of WntA and fz2 in WntA crispant pupae show that they are under positive and negative feedback, respectively. Fz1 is required for Wnt-independent planar cell polarity in the wing epithelium. Fz3 and Fz4 show phenotypes consistent with Wnt competitive-antagonist functions in vein formation (Fz3 and Fz4), wing margin specification (Fz3), and color patterning in the Discalis and Marginal Band Systems (Fz4). Overall, these data show that the WntA/Frizzled2 morphogen-receptor pair forms a signaling axis that instructs butterfly color patterning and shed light on the functional diversity of insect Frizzled receptors.
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Affiliation(s)
- Joseph J. Hanly
- Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA
- Smithsonian Tropical Research Institute, Gamboa 0843-03092, Panama
| | - Ling S. Loh
- Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA
| | - Anyi Mazo-Vargas
- Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA
| | | | - Luca Livraghi
- Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA
- Smithsonian Tropical Research Institute, Gamboa 0843-03092, Panama
- Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK
| | - Amruta Tendolkar
- Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA
| | - Christopher R. Day
- Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA
- Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, Durham, NC 27708, USA
| | - Neringa Liutikaite
- Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA
| | - Emily A. Earls
- Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA
| | - Olaf B. W. H. Corning
- Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA
| | - Natalie D'Souza
- Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA
| | - José J. Hermina-Perez
- Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA
| | - Caroline Mehta
- Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA
| | - Julia A. Ainsworth
- Department of Cell and Developmental Biology, UC San Diego, La Jolla, CA, USA
| | - Matteo Rossi
- Division of Evolutionary Biology, Ludwig Maximilian University, Munich 80539, Germany
| | - Riccardo Papa
- Department of Biology, University of Puerto Rico at Río Piedras, San Juan 00931, Puerto Rico
- Molecular Sciences and Research Center, University of Puerto Rico, San Juan 00931, Puerto Rico
- Dipartimento di Scienze Chimiche della Vita e della Sostenibilità Ambientale, Università di Parma, Parma 43121, Italy
| | - W. Owen McMillan
- Smithsonian Tropical Research Institute, Gamboa 0843-03092, Panama
| | - Michael W. Perry
- Department of Cell and Developmental Biology, UC San Diego, La Jolla, CA, USA
| | - Arnaud Martin
- Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA
- Smithsonian Tropical Research Institute, Gamboa 0843-03092, Panama
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7
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Xiong F, Chevalier Y, Klar RM. Parallel Chondrogenesis and Osteogenesis Tissue Morphogenesis in Muscle Tissue via Combinations of TGF-β Supergene Family Members. Cartilage 2023:19476035231196224. [PMID: 37714817 DOI: 10.1177/19476035231196224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/17/2023] Open
Abstract
OBJECTIVE This study aimed to decipher the temporal and spatial signaling code for clinical cartilage and bone regeneration. We investigated the effects of continuous equal dosages of a single, dual, or triplicate growth factor combination of bone morphogenetic protein (BMP)-2, transforming growth factor (TGF)-β3, and/or BMP-7 on muscle tissue over a culturing period. The hypothesis was that specific growth factor combinations at specific time points direct tissue transformation toward endochondral bone or cartilage formation. DESIGN The harvested muscle tissues from F-344 adult male rats were cultured in 96-well plates maintained in a specific medium and cultured at specific conditions. And the multidimensional and multi-time point analyses were performed at both the genetic and protein levels. RESULTS The results insinuate that the application of growth factor stimulates a chaotic tissue response that does not follow a chronological signaling cascade. Both osteogenic and chondrogenic genes showed upregulation after induction, a similar result was also observed in the semiquantitative analysis after immunohistochemical staining against different antigens. CONCLUSIONS The study showed that multiple TGF-β superfamily proteins applied to tissue stimulate developmental tissue processes that do not follow current tissue formation rules. The findings contribute to the understanding of the chronological order of signals and expression patterns needed to achieve chondrogenesis, articular chondrogenesis, or osteogenesis, which is crucial for the development of treatments that can regrow bone and articular cartilage clinically.
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Affiliation(s)
- Fei Xiong
- Wuxi Hand Surgery Hospital, Wuxi, China
| | - Yan Chevalier
- Department of Orthopedics, Physical Medicine and Rehabilitation, University Hospital, LMU Munich, Germany
| | - Roland M Klar
- Department of Oral and Craniofacial Sciences, University of Missouri-Kansas City, School of Dentistry, Kansas City, MO, USA
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8
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Grodstein J, McMillen P, Levin M. Closing the loop on morphogenesis: a mathematical model of morphogenesis by closed-loop reaction-diffusion. Front Cell Dev Biol 2023; 11:1087650. [PMID: 37645245 PMCID: PMC10461482 DOI: 10.3389/fcell.2023.1087650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 07/31/2023] [Indexed: 08/31/2023] Open
Abstract
Morphogenesis, the establishment and repair of emergent complex anatomy by groups of cells, is a fascinating and biomedically-relevant problem. One of its most fascinating aspects is that a developing embryo can reliably recover from disturbances, such as splitting into twins. While this reliability implies some type of goal-seeking error minimization over a morphogenic field, there are many gaps with respect to detailed, constructive models of such a process. A common way to achieve reliability is negative feedback, which requires characterizing the existing body shape to create an error signal-but measuring properties of a shape may not be simple. We show how cells communicating in a wave-like pattern could analyze properties of the current body shape. We then describe a closed-loop negative-feedback system for creating reaction-diffusion (RD) patterns with high reliability. Specifically, we use a wave to count the number of peaks in a RD pattern, letting us use a negative-feedback controller to create a pattern with N repetitions, where N can be altered over a wide range. Furthermore, the individual repetitions of the RD pattern can be easily stretched or shrunk under genetic control to create, e.g., some morphological features larger than others. This work contributes to the exciting effort of understanding design principles of morphological computation, which can be used to understand evolved developmental mechanisms, manipulate them in regenerative-medicine settings, or engineer novel synthetic morphology constructs with desired robust behavior.
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Affiliation(s)
- Joel Grodstein
- Department of Electrical and Computer Engineering, Tufts University, Medford, MA, United States
| | - Patrick McMillen
- Allen Discovery Center at Tufts University, Medford, MA, United States
| | - Michael Levin
- Allen Discovery Center at Tufts University, Medford, MA, United States
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, MA, United States
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9
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Maunsell HR, Ellis K, Kelley MW, Driver EC. Lrrn1 Regulates Medial Boundary Formation in the Developing Mouse Organ of Corti. J Neurosci 2023; 43:5305-5318. [PMID: 37369584 PMCID: PMC10359035 DOI: 10.1523/jneurosci.2141-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 05/12/2023] [Accepted: 06/10/2023] [Indexed: 06/29/2023] Open
Abstract
One of the most striking aspects of the sensory epithelium of the mammalian cochlea, the organ of Corti (OC), is the presence of precise boundaries between sensory and nonsensory cells at its medial and lateral edges. A particular example of this precision is the single row of inner hair cells (IHCs) and associated supporting cells along the medial (neural) boundary. Despite the regularity of this boundary, the developmental processes and genetic factors that contribute to its specification are poorly understood. In this study we demonstrate that Leucine Rich Repeat Neuronal 1 (Lrrn1), which codes for a single-pass, transmembrane protein, is expressed before the development of the mouse organ of Corti in the row of cells that will form its medial border. Deletion of Lrrn1 in mice of mixed sex leads to disruptions in boundary formation that manifest as ectopic inner hair cells and supporting cells. Genetic and pharmacological manipulations demonstrate that Lrrn1 interacts with the Notch signaling pathway and strongly suggest that Lrrn1 normally acts to enhance Notch signaling across the medial boundary. This interaction is required to promote formation of the row of inner hair cells and suppress the conversion of adjacent nonsensory cells into hair cells and supporting cells. These results identify Lrrn1 as an important regulator of boundary formation and cellular patterning during development of the organ of Corti.SIGNIFICANCE STATEMENT Patterning of the developing mammalian cochlea into distinct sensory and nonsensory regions and the specification of multiple different cell fates within those regions are critical for proper auditory function. Here, we report that the transmembrane protein Leucine Rich Repeat Neuronal 1 (LRRN1) is expressed along the sharp medial boundary between the single row of mechanosensory inner hair cells (IHCs) and adjacent nonsensory cells. Formation of this boundary is mediated in part by Notch signaling, and loss of Lrrn1 leads to disruptions in boundary formation similar to those caused by a reduction in Notch activity, suggesting that LRRN1 likely acts to enhance Notch signaling. Greater understanding of sensory/nonsensory cell fate decisions in the cochlea will help inform the development of regenerative strategies aimed at restoring auditory function.
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Affiliation(s)
- Helen R Maunsell
- Porter Neuroscience Research Center, Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, Bethesda, Maryland 20892
| | - Kathryn Ellis
- Porter Neuroscience Research Center, Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, Bethesda, Maryland 20892
| | - Matthew W Kelley
- Porter Neuroscience Research Center, Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, Bethesda, Maryland 20892
| | - Elizabeth Carroll Driver
- Porter Neuroscience Research Center, Laboratory of Cochlear Development, National Institute on Deafness and Other Communication Disorders, Bethesda, Maryland 20892
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Zhang F, Lu Y. The Sphingosine 1-Phosphate Axis: an Emerging Therapeutic Opportunity for Endometriosis. Reprod Sci 2023; 30:2040-2059. [PMID: 36662421 PMCID: PMC9857924 DOI: 10.1007/s43032-023-01167-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 01/04/2023] [Indexed: 01/21/2023]
Abstract
Endometriosis is a common condition in women of reproductive age, but its current interventions are unsatisfactory. Recent research discovered a dysregulation of the sphingosine 1-phosphate (S1P) signaling pathway in endometriosis and showed a positive outcome by targeting it. The S1P axis participates in a series of fundamental pathophysiological processes. This narrative review is trying to expound the reported and putative (due to limited reports in this area for now) interactions between the S1P axis and endometriosis in those pathophysiological processes, to provide some perspectives for future research. In short, S1P signaling pathway is highly activated in the endometriotic lesion. The S1P concentration has a surge in the endometriotic cyst fluid and the peritoneal fluid, with the downstream dysregulation of its receptors. The S1P axis plays an essential role in the migration and activation of the immune cells, fibrosis, angiogenesis, pain-related hyperalgesia, and innervation. S1P receptor (S1PR) modulators showed an impressive therapeutic effect by targeting the different S1P receptors in the endometriosis model, and many other conditions resemble endometriosis. And several of them already got approval for clinical application in many diseases, which means a drug repurposing direction and a rapid clinical translation for endometriosis treatments.
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Affiliation(s)
- Fengrui Zhang
- Department of Gynecology, The Obstetrics & Gynecology Hospital of Fudan University, 419 Fangxie Rd, Shanghai, 200011, People's Republic of China
| | - Yuan Lu
- Department of Gynecology, The Obstetrics & Gynecology Hospital of Fudan University, 419 Fangxie Rd, Shanghai, 200011, People's Republic of China.
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11
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Chen L, Yan Y, Ke H, Zhang Z, Meng C, Ma L, Sun Z, Chen B, Liu Z, Wang G, Yang J, Wu J, Li Z, Wu L, Zhang G, Zhang Y, Wang X, Ma Z. SEP-like genes of Gossypium hirsutum promote flowering via targeting different loci in a concentration-dependent manner. FRONTIERS IN PLANT SCIENCE 2022; 13:990221. [PMID: 36531379 PMCID: PMC9752867 DOI: 10.3389/fpls.2022.990221] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Accepted: 11/02/2022] [Indexed: 06/17/2023]
Abstract
SEP genes are famous for their function in the morphological novelty of bisexual flowers. Although the diverse functions of SEP genes were reported, only the regulatory mechanisms underlying floral organ development have been addressed. In this study, we identified SEP-like genes in Gossypium and found that SEP3 genes were duplicated in diploid cotton varieties. GhSEP4.1 and GhSEP4.2 were abundantly transcribed in the shoot apical meristem (SAM), but only GhSEP4.2 was expressed in the leaf vasculature. The expression pattern of GhSEPs in floral organs was conserved with that of homologs in Arabidopsis, except for GhSEP2 that was preponderantly expressed in ovules and fibers. The overexpression and silencing of each single GhSEP gene suggested their distinct role in promoting flowering via direct binding to GhAP1 and GhLFY genomic regions. The curly leaf and floral defects in overexpression lines with a higher expression of GhSEP genes revealed the concentration-dependent target gene regulation of GhSEP proteins. Moreover, GhSEP proteins were able to dimerize and interact with flowering time regulators. Together, our results suggest the dominant role of GhSEP4.2 in leaves to promote flowering via GhAP1-A04, and differently accumulated GhSEP proteins in the SAM alternately participate in forming the dynamic tetramer complexes to target at the different loci of GhAP1 and GhLFY to maintain reproductive growth. The regulatory roles of cotton SEP genes reveal their conserved and diversified functions.
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12
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Creating artificial signaling gradients to spatially pattern engineered tissues. Curr Opin Biotechnol 2022; 78:102810. [PMID: 36182872 DOI: 10.1016/j.copbio.2022.102810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 08/26/2022] [Accepted: 08/30/2022] [Indexed: 12/14/2022]
Abstract
Artificially constructing a fully-fledged tissue - comprising multiple cell types whose identities and spatial arrangements reflect those of a native tissue - remains daunting. There has been impressive progress in generating three-dimensional cell cultures (often dubbed 'organoids') from stem cells. However, it is critical to appreciate that not all such three-dimensional cultures will intrinsically self-organize to spontaneously recreate native tissue architecture. Instead, most tissues in vivo are exogenously patterned by extracellular signaling gradients emanating from organizer cells located outside the tissue. Innovations to impose artificial signaling gradients - using microfluidics, optogenetics, or introducing organizer cells - could thus prove decisive to create spatially patterned tissues in vitro. Additionally, unified terminology to describe these tissue-like simulacra as 'aggregates', 'spheroids', or 'organoids' will be critical for the field.
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13
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Copeland J, Wilson K, Simoes-Costa M. Micromanaging pattern formation: miRNA regulation of signaling systems in vertebrate development. FEBS J 2022; 289:5166-5175. [PMID: 34310060 DOI: 10.1111/febs.16139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 06/14/2021] [Accepted: 07/23/2021] [Indexed: 11/29/2022]
Abstract
Early embryogenesis requires the establishment of fields of progenitor cells with distinct molecular signatures. A balance of intrinsic and extrinsic cues determines the boundaries of embryonic territories and pushes progenitor cells toward different fates. This process involves multiple layers of regulation, including signaling systems, transcriptional networks, and post-transcriptional control. In recent years, microRNAs (miRNAs) have emerged as undisputed regulators of developmental processes. Here, we discuss how miRNAs regulate pattern formation during vertebrate embryogenesis. We survey how miRNAs modulate the activity of signaling pathways to optimize transcriptional responses in embryonic cells. We also examine how localized RNA interference can generate spatial complexity during early development. Unraveling the complex crosstalk between miRNAs, signaling systems and cell fate decisions will be crucial for our understanding of developmental outcomes and disease.
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Affiliation(s)
- Jacqueline Copeland
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Kayla Wilson
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Marcos Simoes-Costa
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
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14
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Perkins ML, Gandara L, Crocker J. A synthetic synthesis to explore animal evolution and development. Philos Trans R Soc Lond B Biol Sci 2022; 377:20200517. [PMID: 35634925 PMCID: PMC9149795 DOI: 10.1098/rstb.2020.0517] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Identifying the general principles by which genotypes are converted into phenotypes remains a challenge in the post-genomic era. We still lack a predictive understanding of how genes shape interactions among cells and tissues in response to signalling and environmental cues, and hence how regulatory networks generate the phenotypic variation required for adaptive evolution. Here, we discuss how techniques borrowed from synthetic biology may facilitate a systematic exploration of evolvability across biological scales. Synthetic approaches permit controlled manipulation of both endogenous and fully engineered systems, providing a flexible platform for investigating causal mechanisms in vivo. Combining synthetic approaches with multi-level phenotyping (phenomics) will supply a detailed, quantitative characterization of how internal and external stimuli shape the morphology and behaviour of living organisms. We advocate integrating high-throughput experimental data with mathematical and computational techniques from a variety of disciplines in order to pursue a comprehensive theory of evolution. This article is part of the theme issue ‘Genetic basis of adaptation and speciation: from loci to causative mutations’.
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Affiliation(s)
- Mindy Liu Perkins
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Lautaro Gandara
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Justin Crocker
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
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15
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Reciprocal Regulation of Shh Trafficking and H2O2 Levels via a Noncanonical BOC-Rac1 Pathway. Antioxidants (Basel) 2022; 11:antiox11040718. [PMID: 35453403 PMCID: PMC9025708 DOI: 10.3390/antiox11040718] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 03/25/2022] [Accepted: 04/03/2022] [Indexed: 11/21/2022] Open
Abstract
Among molecules that bridge environment, cell metabolism, and cell signaling, hydrogen peroxide (H2O2) recently appeared as an emerging but central player. Its level depends on cell metabolism and environment and was recently shown to play key roles during embryogenesis, contrasting with its long-established role in disease progression. We decided to explore whether the secreted morphogen Sonic hedgehog (Shh), known to be essential in a variety of biological processes ranging from embryonic development to adult tissue homeostasis and cancers, was part of these interactions. Here, we report that H2O2 levels control key steps of Shh delivery in cell culture: increased levels reduce primary secretion, stimulate endocytosis and accelerate delivery to recipient cells; in addition, physiological in vivo modulation of H2O2 levels changes Shh distribution and tissue patterning. Moreover, a feedback loop exists in which Shh trafficking controls H2O2 synthesis via a non-canonical BOC-Rac1 pathway, leading to cytoneme growth. Our findings reveal that Shh directly impacts its own distribution, thus providing a molecular explanation for the robustness of morphogenesis to both environmental insults and individual variability.
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16
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Hoyle DJ, Dranow DB, Schilling TF. Pthlha and mechanical force control early patterning of growth zones in the zebrafish craniofacial skeleton. Development 2022; 149:dev199826. [PMID: 34919126 PMCID: PMC8917414 DOI: 10.1242/dev.199826] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 12/07/2021] [Indexed: 11/23/2022]
Abstract
Secreted signals in patterning systems often induce repressive signals that shape their distributions in space and time. In developing growth plates (GPs) of endochondral long bones, Parathyroid hormone-like hormone (Pthlh) inhibits Indian hedgehog (Ihh) to form a negative-feedback loop that controls GP progression and bone size. Whether similar systems operate in other bones and how they arise during embryogenesis remain unclear. We show that Pthlha expression in the zebrafish craniofacial skeleton precedes chondrocyte differentiation and restricts where cells undergo hypertrophy, thereby initiating a future GP. Loss of Pthlha leads to an expansion of cells expressing a novel early marker of the hypertrophic zone (HZ), entpd5a, and later HZ markers, such as ihha, whereas local Pthlha misexpression induces ectopic entpd5a expression. Formation of this early pre-HZ correlates with onset of muscle contraction and requires mechanical force; paralysis leads to loss of entpd5a and ihha expression in the pre-HZ, mislocalized pthlha expression and no subsequent ossification. These results suggest that local Pthlh sources combined with force determine HZ locations, establishing the negative-feedback loop that later maintains GPs.
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Affiliation(s)
| | | | - Thomas F. Schilling
- Department of Developmental and Cell Biology, University of California, Irvine, CA 92693, USA
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17
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Anatomically distinct fibroblast subsets determine skin autoimmune patterns. Nature 2021; 601:118-124. [PMID: 34912121 DOI: 10.1038/s41586-021-04221-8] [Citation(s) in RCA: 95] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 11/05/2021] [Indexed: 12/18/2022]
Abstract
The skin serves as a physical barrier and an immunological interface that protects the body from the external environment1-3. Aberrant activation of immune cells can induce common skin autoimmune diseases such as vitiligo, which are often characterized by bilateral symmetric lesions in certain anatomic regions of the body4-6. Understanding what orchestrates the activities of cutaneous immune cells at an organ level is necessary for the treatment of autoimmune diseases. Here we identify subsets of dermal fibroblasts that are responsible for driving patterned autoimmune activity, by using a robust mouse model of vitiligo that is based on the activation of endogenous auto-reactive CD8+ T cells that target epidermal melanocytes. Using a combination of single-cell analysis of skin samples from patients with vitiligo, cell-type-specific genetic knockouts and engraftment experiments, we find that among multiple interferon-γ (IFNγ)-responsive cell types in vitiligo-affected skin, dermal fibroblasts are uniquely required to recruit and activate CD8+ cytotoxic T cells through secreted chemokines. Anatomically distinct human dermal fibroblasts exhibit intrinsic differences in the expression of chemokines in response to IFNγ. In mouse models of vitiligo, regional IFNγ-resistant fibroblasts determine the autoimmune pattern of depigmentation in the skin. Our study identifies anatomically distinct fibroblasts with permissive or repressive IFNγ responses as the key determinant of body-level patterns of lesions in vitiligo, and highlights mesenchymal subpopulations as therapeutic targets for treating autoimmune diseases.
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18
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Nakamura K, Tanaka W, Sada K, Kubota R, Aoyama T, Urayama K, Hamachi I. Phototriggered Spatially Controlled Out-of-Equilibrium Patterns of Peptide Nanofibers in a Self-Sorting Double Network Hydrogel. J Am Chem Soc 2021; 143:19532-19541. [PMID: 34767720 DOI: 10.1021/jacs.1c09172] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Out-of-equilibrium patterns arising from diffusion processes are ubiquitous in nature, although they have not been fully exploited for the design of artificial materials. Here, we describe the formation of phototriggered out-of-equilibrium patterns using photoresponsive peptide-based nanofibers in a self-sorting double network hydrogel. Light irradiation using a photomask followed by thermal incubation induced the spatially controlled condensation of peptide nanofibers. According to confocal images and spectroscopic analyses, metastable nanofibers photodecomposed in the irradiated areas, where thermodynamically stable nanofibers reconstituted and condensed with a supply of monomers from the nonirradiated areas. These supramolecular events were regulated by light and diffusion to facilitate the creation of unique out-of-equilibrium patterns, including two lines from a one-line photomask and a line pattern of a protein immobilized in the hydrogel.
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Affiliation(s)
- Keisuke Nakamura
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Wataru Tanaka
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Kei Sada
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Ryou Kubota
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Takuma Aoyama
- Department of Macromolecular Science and Engineering, Kyoto Institute of Technology, Matsugasaki, Kyoto 606-8585, Japan
| | - Kenji Urayama
- Department of Macromolecular Science and Engineering, Kyoto Institute of Technology, Matsugasaki, Kyoto 606-8585, Japan
| | - Itaru Hamachi
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan.,JST-ERATO, Hamachi Innovative Molecular Technology for Neuroscience, Nishikyo-ku, Kyoto 615-8530, Japan
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19
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Hatori R, Wood BM, Oliveira Barbosa G, Kornberg TB. Regulated delivery controls Drosophila Hedgehog, Wingless, and Decapentaplegic signaling. eLife 2021; 10:71744. [PMID: 34292155 PMCID: PMC8376250 DOI: 10.7554/elife.71744] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 07/13/2021] [Indexed: 02/06/2023] Open
Abstract
Morphogen signaling proteins disperse across tissues to activate signal transduction in target cells. We investigated dispersion of Hedgehog (Hh), Wnt homolog Wingless (Wg), and Bone morphogenic protein homolog Decapentaplegic (Dpp) in the Drosophila wing imaginal disc. We discovered that delivery of Hh, Wg, and Dpp to their respective targets is regulated. We found that <5% of Hh and <25% of Wg are taken up by disc cells and activate signaling. The amount of morphogen that is taken up and initiates signaling did not change when the level of morphogen expression was varied between 50 and 200% (Hh) or 50 and 350% (Wg). Similar properties were observed for Dpp. We analyzed an area of 150 μm×150 μm that includes Hh-responding cells of the disc as well as overlying tracheal cells and myoblasts that are also activated by disc-produced Hh. We found that the extent of signaling in the disc was unaffected by the presence or absence of the tracheal and myoblast cells, suggesting that the mechanism that disperses Hh specifies its destinations to particular cells, and that target cells do not take up Hh from a common pool.
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Affiliation(s)
- Ryo Hatori
- Cardiovascular Research Institute University of California, San Francisco, San Francisco, United States
| | - Brent M Wood
- Cardiovascular Research Institute University of California, San Francisco, San Francisco, United States
| | | | - Thomas B Kornberg
- Cardiovascular Research Institute University of California, San Francisco, San Francisco, United States
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20
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Kuyyamudi C, Menon SN, Sinha S. Contact-mediated cellular communication supplements positional information to regulate spatial patterning during development. Phys Rev E 2021; 103:062409. [PMID: 34271677 DOI: 10.1103/physreve.103.062409] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 06/02/2021] [Indexed: 12/12/2022]
Abstract
Development in multicellular organisms is marked by a high degree of spatial organization of the cells attaining distinct fates in the embryo. Recent experiments showing that suppression of intercellular interactions can alter the spatial patterns arising during development suggest that cell fates cannot be determined by the exclusive regulation of differential gene expression by morphogen gradients (the conventional view encapsulated in the French flag model). Using a mathematical model that describes the receptor-ligand interaction between cells in close physical proximity, we show that such intercellular signaling can regulate the process of selective gene expression within each cell, allowing information from the cellular neighborhood to influence the process by which the thresholds of morphogen concentration that dictate cell fates adaptively emerge. This results in local modulations of the positional cues provided by the global field set up by the morphogen, allowing interaction-mediated self-organized pattern formation to complement boundary-organized mechanisms in the context of development.
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Affiliation(s)
- Chandrashekar Kuyyamudi
- The Institute of Mathematical Sciences, CIT Campus, Taramani, Chennai 600113, India.,Homi Bhabha National Institute, Anushaktinagar, Mumbai 400 094, India
| | - Shakti N Menon
- The Institute of Mathematical Sciences, CIT Campus, Taramani, Chennai 600113, India
| | - Sitabhra Sinha
- The Institute of Mathematical Sciences, CIT Campus, Taramani, Chennai 600113, India.,Homi Bhabha National Institute, Anushaktinagar, Mumbai 400 094, India
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21
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Lord ND, Carte AN, Abitua PB, Schier AF. The pattern of nodal morphogen signaling is shaped by co-receptor expression. eLife 2021; 10:e54894. [PMID: 34036935 PMCID: PMC8266389 DOI: 10.7554/elife.54894] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Accepted: 05/26/2021] [Indexed: 12/13/2022] Open
Abstract
Embryos must communicate instructions to their constituent cells over long distances. These instructions are often encoded in the concentration of signals called morphogens. In the textbook view, morphogen molecules diffuse from a localized source to form a concentration gradient, and target cells adopt fates by measuring the local morphogen concentration. However, natural patterning systems often incorporate numerous co-factors and extensive signaling feedback, suggesting that embryos require additional mechanisms to generate signaling patterns. Here, we examine the mechanisms of signaling pattern formation for the mesendoderm inducer Nodal during zebrafish embryogenesis. We find that Nodal signaling activity spans a normal range in the absence of signaling feedback and relay, suggesting that diffusion is sufficient for Nodal gradient formation. We further show that the range of endogenous Nodal ligands is set by the EGF-CFC co-receptor Oep: in the absence of Oep, Nodal activity spreads to form a nearly uniform distribution throughout the embryo. In turn, increasing Oep levels sensitizes cells to Nodal ligands. We recapitulate these experimental results with a computational model in which Oep regulates the diffusive spread of Nodal ligands by setting the rate of capture by target cells. This model predicts, and we confirm in vivo, the surprising observation that a failure to replenish Oep transforms the Nodal signaling gradient into a travelling wave. These results reveal that patterns of Nodal morphogen signaling are shaped by co-receptor-mediated restriction of ligand spread and sensitization of responding cells.
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Affiliation(s)
- Nathan D Lord
- Department of Molecular and Cellular Biology, Harvard UniversityCambridgeUnited States
| | - Adam N Carte
- Department of Molecular and Cellular Biology, Harvard UniversityCambridgeUnited States
- Systems, Synthetic, and Quantitative Biology PhD Program, Harvard UniversityCambridgeUnited States
- Biozentrum, University of BaselBaselSwitzerland
| | - Philip B Abitua
- Department of Molecular and Cellular Biology, Harvard UniversityCambridgeUnited States
| | - Alexander F Schier
- Department of Molecular and Cellular Biology, Harvard UniversityCambridgeUnited States
- Biozentrum, University of BaselBaselSwitzerland
- Allen Discovery Center for Cell Lineage Tracing, University of WashingtonSeattleUnited States
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22
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Genuth MA, Holley SA. Mechanics as a Means of Information Propagation in Development. Bioessays 2020; 42:e2000121. [PMID: 32885468 PMCID: PMC7722802 DOI: 10.1002/bies.202000121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 08/07/2020] [Indexed: 12/19/2022]
Abstract
New research demonstrates that mechanics can serve as a means of information propagation in developing embryos. Historically, the study of embryonic development has had a dichotomy between morphogens and pattern formation on the one hand and morphogenesis and mechanics on the other. Secreted signals are the preeminent means of information propagation between cells and used to control cell fate, while physical forces act downstream or in parallel to shape tissue morphogenesis. However, recent work has blurred this division of function by demonstrating that mechanics can serve as a means of information propagation. Adhesive or repulsive interactions can propagate through a tissue as a wave. These waves are rapid and directional and can be used to control the flux of cells through a developmental trajectory. Here, two examples are reviewed in which mechanics both guides and mediates morphogenesis and two examples in which mechanics intertwines with morphogens to regulate cell fate.
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Affiliation(s)
- Miriam A Genuth
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
| | - Scott A Holley
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
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23
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York HM, Coyle J, Arumugam S. To be more precise: the role of intracellular trafficking in development and pattern formation. Biochem Soc Trans 2020; 48:2051-2066. [PMID: 32915197 PMCID: PMC7609031 DOI: 10.1042/bst20200223] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/24/2020] [Accepted: 08/26/2020] [Indexed: 02/07/2023]
Abstract
Living cells interpret a variety of signals in different contexts to elucidate functional responses. While the understanding of signalling molecules, their respective receptors and response at the gene transcription level have been relatively well-explored, how exactly does a single cell interpret a plethora of time-varying signals? Furthermore, how their subsequent responses at the single cell level manifest in the larger context of a developing tissue is unknown. At the same time, the biophysics and chemistry of how receptors are trafficked through the complex dynamic transport network between the plasma membrane-endosome-lysosome-Golgi-endoplasmic reticulum are much more well-studied. How the intracellular organisation of the cell and inter-organellar contacts aid in orchestrating trafficking, as well as signal interpretation and modulation by the cells are beginning to be uncovered. In this review, we highlight the significant developments that have strived to integrate endosomal trafficking, signal interpretation in the context of developmental biology and relevant open questions with a few chosen examples. Furthermore, we will discuss the imaging technologies that have been developed in the recent past that have the potential to tremendously accelerate knowledge gain in this direction while shedding light on some of the many challenges.
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Affiliation(s)
- Harrison M. York
- Monash Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, VIC 3800, Australia
| | - Joanne Coyle
- Monash Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, VIC 3800, Australia
| | - Senthil Arumugam
- Monash Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, VIC 3800, Australia
- European Molecular Biological Laboratory Australia (EMBL Australia), Monash University, Melbourne, VIC 3800, Australia
- ARC Centre of Excellence in Advanced Molecular Imaging, Monash University, Melbourne, VIC 3800, Australia
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24
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Cosgrove J, Novkovic M, Albrecht S, Pikor NB, Zhou Z, Onder L, Mörbe U, Cupovic J, Miller H, Alden K, Thuery A, O'Toole P, Pinter R, Jarrett S, Taylor E, Venetz D, Heller M, Uguccioni M, Legler DF, Lacey CJ, Coatesworth A, Polak WG, Cupedo T, Manoury B, Thelen M, Stein JV, Wolf M, Leake MC, Timmis J, Ludewig B, Coles MC. B cell zone reticular cell microenvironments shape CXCL13 gradient formation. Nat Commun 2020; 11:3677. [PMID: 32699279 PMCID: PMC7376062 DOI: 10.1038/s41467-020-17135-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Accepted: 03/12/2020] [Indexed: 02/07/2023] Open
Abstract
Through the formation of concentration gradients, morphogens drive graded responses to extracellular signals, thereby fine-tuning cell behaviors in complex tissues. Here we show that the chemokine CXCL13 forms both soluble and immobilized gradients. Specifically, CXCL13+ follicular reticular cells form a small-world network of guidance structures, with computer simulations and optimization analysis predicting that immobilized gradients created by this network promote B cell trafficking. Consistent with this prediction, imaging analysis show that CXCL13 binds to extracellular matrix components in situ, constraining its diffusion. CXCL13 solubilization requires the protease cathepsin B that cleaves CXCL13 into a stable product. Mice lacking cathepsin B display aberrant follicular architecture, a phenotype associated with effective B cell homing to but not within lymph nodes. Our data thus suggest that reticular cells of the B cell zone generate microenvironments that shape both immobilized and soluble CXCL13 gradients.
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Affiliation(s)
- Jason Cosgrove
- York Computational Immunology Lab, University of York, York, UK
- Centre for Immunology and Infection, Department of Biology and Hull York Medical School, University of York, York, UK
- Department of Electronic Engineering, University of York, York, UK
| | - Mario Novkovic
- Institute of Immunobiology, Kantonsspital St. Gallen, St. Gallen, Switzerland
| | - Stefan Albrecht
- Theodor Kocher Institute, University of Bern, Bern, Switzerland
| | - Natalia B Pikor
- Institute of Immunobiology, Kantonsspital St. Gallen, St. Gallen, Switzerland
| | - Zhaoukun Zhou
- Department of Biology, University of York, York, UK
- Biological Physical Sciences Institute (BPSI), University of York, York, UK
- Department of Physics, University of York, York, UK
| | - Lucas Onder
- Institute of Immunobiology, Kantonsspital St. Gallen, St. Gallen, Switzerland
| | - Urs Mörbe
- Institute of Immunobiology, Kantonsspital St. Gallen, St. Gallen, Switzerland
| | - Jovana Cupovic
- Institute of Immunobiology, Kantonsspital St. Gallen, St. Gallen, Switzerland
| | - Helen Miller
- Department of Biology, University of York, York, UK
- Biological Physical Sciences Institute (BPSI), University of York, York, UK
- Department of Physics, University of York, York, UK
| | - Kieran Alden
- York Computational Immunology Lab, University of York, York, UK
- Department of Electronic Engineering, University of York, York, UK
| | - Anne Thuery
- Centre for Immunology and Infection, Department of Biology and Hull York Medical School, University of York, York, UK
| | | | - Rita Pinter
- Kennedy Institute of Rheumatology at the University of Oxford, Oxford, UK
| | - Simon Jarrett
- Kennedy Institute of Rheumatology at the University of Oxford, Oxford, UK
| | - Emily Taylor
- Centre for Immunology and Infection, Department of Biology and Hull York Medical School, University of York, York, UK
| | - Daniel Venetz
- Institute for Research in Biomedicine, Università della Svizzera italiana, Bellinzona, Switzerland
| | - Manfred Heller
- Department of Clinical Research, University of Bern, Bern, Switzerland
| | - Mariagrazia Uguccioni
- Institute for Research in Biomedicine, Università della Svizzera italiana, Bellinzona, Switzerland
| | - Daniel F Legler
- Biotechnology Institute Thurgau (BITg) at the University of Konstanz, Kreuzlingen, Switzerland
| | - Charles J Lacey
- York Computational Immunology Lab, University of York, York, UK
| | | | - Wojciech G Polak
- Department of Surgery, Erasmus University Medical Centre, Rotterdam, Netherlands
| | - Tom Cupedo
- Department of Hematology, Erasmus University Medical Centre, Rotterdam, Netherlands
| | - Bénedicte Manoury
- Institut Necker Enfants Malades, INSERM U1151- CNRS UMR 8253, 149 rue de Sèvres 75015 Paris, France Université René Descartes, 75005, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Marcus Thelen
- Institute for Research in Biomedicine, Università della Svizzera italiana, Bellinzona, Switzerland
| | - Jens V Stein
- Department of Oncology, Microbiology and Immunology, University of Fribourg, Fribourg, Switzerland
| | - Marlene Wolf
- Theodor Kocher Institute, University of Bern, Bern, Switzerland
| | - Mark C Leake
- Department of Biology, University of York, York, UK.
- Biological Physical Sciences Institute (BPSI), University of York, York, UK.
- Department of Physics, University of York, York, UK.
| | - Jon Timmis
- York Computational Immunology Lab, University of York, York, UK.
- Department of Electronic Engineering, University of York, York, UK.
| | - Burkhard Ludewig
- Institute of Immunobiology, Kantonsspital St. Gallen, St. Gallen, Switzerland.
| | - Mark C Coles
- York Computational Immunology Lab, University of York, York, UK.
- Kennedy Institute of Rheumatology at the University of Oxford, Oxford, UK.
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25
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Modeling of Wnt-mediated tissue patterning in vertebrate embryogenesis. PLoS Comput Biol 2020; 16:e1007417. [PMID: 32579554 PMCID: PMC7340325 DOI: 10.1371/journal.pcbi.1007417] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 07/07/2020] [Accepted: 05/14/2020] [Indexed: 11/19/2022] Open
Abstract
During embryogenesis, morphogens form a concentration gradient in responsive tissue, which is then translated into a spatial cellular pattern. The mechanisms by which morphogens spread through a tissue to establish such a morphogenetic field remain elusive. Here, we investigate by mutually complementary simulations and in vivo experiments how Wnt morphogen transport by cytonemes differs from typically assumed diffusion-based transport for patterning of highly dynamic tissue such as the neural plate in zebrafish. Stochasticity strongly influences fate acquisition at the single cell level and results in fluctuating boundaries between pattern regions. Stable patterning can be achieved by sorting through concentration dependent cell migration and apoptosis, independent of the morphogen transport mechanism. We show that Wnt transport by cytonemes achieves distinct Wnt thresholds for the brain primordia earlier compared with diffusion-based transport. We conclude that a cytoneme-mediated morphogen transport together with directed cell sorting is a potentially favored mechanism to establish morphogen gradients in rapidly expanding developmental systems.
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26
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Cartier A, Hla T. Sphingosine 1-phosphate: Lipid signaling in pathology and therapy. Science 2020; 366:366/6463/eaar5551. [PMID: 31624181 DOI: 10.1126/science.aar5551] [Citation(s) in RCA: 337] [Impact Index Per Article: 84.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 07/30/2019] [Indexed: 12/13/2022]
Abstract
Sphingosine 1-phosphate (S1P), a metabolic product of cell membrane sphingolipids, is bound to extracellular chaperones, is enriched in circulatory fluids, and binds to G protein-coupled S1P receptors (S1PRs) to regulate embryonic development, postnatal organ function, and disease. S1PRs regulate essential processes such as adaptive immune cell trafficking, vascular development, and homeostasis. Moreover, S1PR signaling is a driver of multiple diseases. The past decade has witnessed an exponential growth in this field, in part because of multidisciplinary research focused on this lipid mediator and the application of S1PR-targeted drugs in clinical medicine. This has revealed fundamental principles of lysophospholipid mediator signaling that not only clarify the complex and wide ranging actions of S1P but also guide the development of therapeutics and translational directions in immunological, cardiovascular, neurological, inflammatory, and fibrotic diseases.
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Affiliation(s)
- Andreane Cartier
- Vascular Biology Program, Boston Children's Hospital and Department of Surgery, Harvard Medical School, Boston, MA 02115, USA
| | - Timothy Hla
- Vascular Biology Program, Boston Children's Hospital and Department of Surgery, Harvard Medical School, Boston, MA 02115, USA.
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27
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Houlton J, Abumaria N, Hinkley SFR, Clarkson AN. Therapeutic Potential of Neurotrophins for Repair After Brain Injury: A Helping Hand From Biomaterials. Front Neurosci 2019; 13:790. [PMID: 31427916 PMCID: PMC6688532 DOI: 10.3389/fnins.2019.00790] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 07/15/2019] [Indexed: 12/17/2022] Open
Abstract
Stroke remains the leading cause of long-term disability with limited options available to aid in recovery. Significant effort has been made to try and minimize neuronal damage following stroke with use of neuroprotective agents, however, these treatments have yet to show clinical efficacy. Regenerative interventions have since become of huge interest as they provide the potential to restore damaged neural tissue without being limited by a narrow therapeutic window. Neurotrophins, such as brain-derived neurotrophic factor (BDNF), and their high affinity receptors are actively produced throughout the brain and are involved in regulating neuronal activity and normal day-to-day function. Furthermore, neurotrophins are known to play a significant role in both protection and recovery of function following neurodegenerative diseases such as stroke and traumatic brain injury (TBI). Unfortunately, exogenous administration of these neurotrophins is limited by a lack of blood-brain-barrier (BBB) permeability, poor half-life, and rapid degradation. Therefore, we have focused this review on approaches that provide a direct and sustained neurotrophic support using pharmacological therapies and mimetics, physical activity, and potential drug delivery systems, including discussion around advantages and limitations for use of each of these systems. Finally, we discuss future directions of biomaterial drug-delivery systems, including the incorporation of heparan sulfate (HS) in conjunction with neurotrophin-based interventions.
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Affiliation(s)
- Josh Houlton
- Brain Health Research Centre, Department of Anatomy, University of Otago, Dunedin, New Zealand
| | - Nashat Abumaria
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institute of Brain Science, Fudan University, Shanghai, China
- Department of Laboratory Animal Science, Shanghai Medical College, Fudan University, Shanghai, China
| | - Simon F. R. Hinkley
- The Ferrier Research Institute, Victoria University of Wellington, Petone, New Zealand
| | - Andrew N. Clarkson
- Brain Health Research Centre, Department of Anatomy, University of Otago, Dunedin, New Zealand
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28
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Wolff HB, Davidson LA, Merks RMH. Adapting a Plant Tissue Model to Animal Development: Introducing Cell Sliding into VirtualLeaf. Bull Math Biol 2019; 81:3322-3341. [PMID: 30927191 PMCID: PMC6677868 DOI: 10.1007/s11538-019-00599-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 03/11/2019] [Indexed: 11/16/2022]
Abstract
Cell-based, mathematical modeling of collective cell behavior has become a prominent tool in developmental biology. Cell-based models represent individual cells as single particles or as sets of interconnected particles and predict the collective cell behavior that follows from a set of interaction rules. In particular, vertex-based models are a popular tool for studying the mechanics of confluent, epithelial cell layers. They represent the junctions between three (or sometimes more) cells in confluent tissues as point particles, connected using structural elements that represent the cell boundaries. A disadvantage of these models is that cell-cell interfaces are represented as straight lines. This is a suitable simplification for epithelial tissues, where the interfaces are typically under tension, but this simplification may not be appropriate for mesenchymal tissues or tissues that are under compression, such that the cell-cell boundaries can buckle. In this paper, we introduce a variant of VMs in which this and two other limitations of VMs have been resolved. The new model can also be seen as on off-the-lattice generalization of the Cellular Potts Model. It is an extension of the open-source package VirtualLeaf, which was initially developed to simulate plant tissue morphogenesis where cells do not move relative to one another. The present extension of VirtualLeaf introduces a new rule for cell-cell shear or sliding, from which cell rearrangement (T1) and cell extrusion (T2) transitions emerge naturally, allowing the application of VirtualLeaf to problems of animal development. We show that the updated VirtualLeaf yields different results than the traditional vertex-based models for differential adhesion-driven cell sorting and for the neighborhood topology of soft cellular networks.
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Affiliation(s)
- Henri B Wolff
- Centrum Wiskunde and Informatica, Science Park 123, 1098 XG, Amsterdam, The Netherlands
- Departments of Bioengineering, Developmental Biology, and Computational and Systems Biology, University of Pittsburgh, Bioscience Tower 3-5059 3501 Fifth Avenue, Pittsburgh, PA, USA
- Department of Epidemiology and Biostatistics, Decision Modeling Center VUmc, Amsterdam UMC location VUmc, PO Box 7057, 1007 MB, Amsterdam, The Netherlands
| | - Lance A Davidson
- Departments of Bioengineering, Developmental Biology, and Computational and Systems Biology, University of Pittsburgh, Bioscience Tower 3-5059 3501 Fifth Avenue, Pittsburgh, PA, USA.
| | - Roeland M H Merks
- Centrum Wiskunde and Informatica, Science Park 123, 1098 XG, Amsterdam, The Netherlands.
- Mathematical Institute, University Leiden, P.O. Box 9512, 2300 RA, Leiden, The Netherlands.
- Mathematical Institute and Institute of Biology, Leiden University, P.O. Box 9505, 2300 RA, Leiden, The Netherlands.
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29
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Organization of Embryonic Morphogenesis via Mechanical Information. Dev Cell 2019; 49:829-839.e5. [PMID: 31178400 DOI: 10.1016/j.devcel.2019.05.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 03/20/2019] [Accepted: 05/03/2019] [Indexed: 01/19/2023]
Abstract
Embryonic organizers establish gradients of diffusible signaling molecules to pattern the surrounding cells. Here, we elucidate an additional mechanism of embryonic organizers that is a secondary consequence of morphogen signaling. Using pharmacological and localized transgenic perturbations, 4D imaging of the zebrafish embryo, systematic analysis of cell motion, and computational modeling, we find that the vertebrate tail organizer orchestrates morphogenesis over distances beyond the range of morphogen signaling. The organizer regulates the rate and coherence of cell motion in the elongating embryo using mechanical information that is transmitted via relay between neighboring cells. This mechanism is similar to a pressure front in granular media and other jammed systems, but in the embryo the mechanical information emerges from self-propelled cell movement and not force transfer between cells. The propagation likely relies upon local biochemical signaling that affects cell contractility, cell adhesion, and/or cell polarity but is independent of transcription and translation.
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30
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Biscetti F, Bonadia N, Nardella E, Cecchini AL, Landolfi R, Flex A. The Role of the Stem Cells Therapy in the Peripheral Artery Disease. Int J Mol Sci 2019; 20:E2233. [PMID: 31067647 PMCID: PMC6539394 DOI: 10.3390/ijms20092233] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 04/26/2019] [Accepted: 05/05/2019] [Indexed: 01/08/2023] Open
Abstract
Vascular complications of diabetes mellitus are an important issue for all clinicians involved in the management of this complex pathology. Although many therapeutic advances have been reached, peripheral arterial disease is still an unsolved problem that each year compromises the quality of life and life span of affected patients. Oftentimes, patients, after ineffective attempts of revascularization, undergo greater amputations. At the moment, there is no effective and definitive treatment available. In this scenario, the therapeutic use of stem cells could be an interesting option. The aim of the present review is to gather all the best available evidence in this regard and to define a new role of the stem cells therapy in this field, from biomarker to possible therapeutic target.
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Affiliation(s)
- Federico Biscetti
- Fondazione Policlinico Universitario A. Gemelli IRCCS, U.O.C. Clinica Medica e Malattie Vascolari, 00168 Roma, Italy; (E.N.); andrealeonardo-@hotmail.it (A.L.C.); (R.L.); (A.F.)
- Laboratory of Vascular Biology and Genetics, Università Cattolica del Sacro Cuore, 00168 Roma, Italy;
| | - Nicola Bonadia
- Laboratory of Vascular Biology and Genetics, Università Cattolica del Sacro Cuore, 00168 Roma, Italy;
- Fondazione Policlinico Universitario A. Gemelli IRCCS, U.O.C. Medicina d’Urgenza e Pronto Soccorso, 00168 Roma, Italy
| | - Elisabetta Nardella
- Fondazione Policlinico Universitario A. Gemelli IRCCS, U.O.C. Clinica Medica e Malattie Vascolari, 00168 Roma, Italy; (E.N.); andrealeonardo-@hotmail.it (A.L.C.); (R.L.); (A.F.)
- Laboratory of Vascular Biology and Genetics, Università Cattolica del Sacro Cuore, 00168 Roma, Italy;
| | - Andrea Leonardo Cecchini
- Fondazione Policlinico Universitario A. Gemelli IRCCS, U.O.C. Clinica Medica e Malattie Vascolari, 00168 Roma, Italy; (E.N.); andrealeonardo-@hotmail.it (A.L.C.); (R.L.); (A.F.)
- Laboratory of Vascular Biology and Genetics, Università Cattolica del Sacro Cuore, 00168 Roma, Italy;
| | - Raffaele Landolfi
- Fondazione Policlinico Universitario A. Gemelli IRCCS, U.O.C. Clinica Medica e Malattie Vascolari, 00168 Roma, Italy; (E.N.); andrealeonardo-@hotmail.it (A.L.C.); (R.L.); (A.F.)
- Università Cattolica del Sacro Cuore, 00168 Roma, Italy
| | - Andrea Flex
- Fondazione Policlinico Universitario A. Gemelli IRCCS, U.O.C. Clinica Medica e Malattie Vascolari, 00168 Roma, Italy; (E.N.); andrealeonardo-@hotmail.it (A.L.C.); (R.L.); (A.F.)
- Laboratory of Vascular Biology and Genetics, Università Cattolica del Sacro Cuore, 00168 Roma, Italy;
- Università Cattolica del Sacro Cuore, 00168 Roma, Italy
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31
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Levin M, Pietak AM, Bischof J. Planarian regeneration as a model of anatomical homeostasis: Recent progress in biophysical and computational approaches. Semin Cell Dev Biol 2019; 87:125-144. [PMID: 29635019 PMCID: PMC6234102 DOI: 10.1016/j.semcdb.2018.04.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 04/03/2018] [Accepted: 04/06/2018] [Indexed: 12/22/2022]
Abstract
Planarian behavior, physiology, and pattern control offer profound lessons for regenerative medicine, evolutionary biology, morphogenetic engineering, robotics, and unconventional computation. Despite recent advances in the molecular genetics of stem cell differentiation, this model organism's remarkable anatomical homeostasis provokes us with truly fundamental puzzles about the origin of large-scale shape and its relationship to the genome. In this review article, we first highlight several deep mysteries about planarian regeneration in the context of the current paradigm in this field. We then review recent progress in understanding of the physiological control of an endogenous, bioelectric pattern memory that guides regeneration, and how modulating this memory can permanently alter the flatworm's target morphology. Finally, we focus on computational approaches that complement reductive pathway analysis with synthetic, systems-level understanding of morphological decision-making. We analyze existing models of planarian pattern control and highlight recent successes and remaining knowledge gaps in this interdisciplinary frontier field.
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Affiliation(s)
- Michael Levin
- Allen Discovery Center at Tufts University, Medford, MA 02155, United States; Biology Department, Tufts University, Medford, MA 02155, United States.
| | - Alexis M Pietak
- Allen Discovery Center at Tufts University, Medford, MA 02155, United States
| | - Johanna Bischof
- Allen Discovery Center at Tufts University, Medford, MA 02155, United States; Biology Department, Tufts University, Medford, MA 02155, United States
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32
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Abstract
Evidence in many experimental systems supports the idea that non-uniform distributions of morphogen proteins encode positional information in developing tissues. There is also strong evidence that morphogen dispersal is mediated by cytonemes and that morphogen proteins transfer from producing to receiving cells at morphogenetic synapses that form at sites of cytoneme contacts. This essay considers some implications of this mechanism and its relevance to various contexts including large single cells such as the pre-cellular Drosophila embryo and the ciliate Stentor.
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Affiliation(s)
- Thomas B Kornberg
- Cardiovascular Research Institute, University of California, San Francisco, CA 94143, United States.
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33
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Mörsdorf D, Müller P. Tuning Protein Diffusivity with Membrane Tethers. Biochemistry 2019; 58:177-181. [PMID: 30562001 PMCID: PMC6344912 DOI: 10.1021/acs.biochem.8b01150] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 12/09/2018] [Indexed: 12/18/2022]
Abstract
Diffusion is essential for biochemical processes because it dominates molecular movement on small scales. Enzymatic reactions, for example, require fast exchange of substrate and product molecules in the local environment of the enzyme to ensure efficient turnover. On larger spatial scales, diffusion of secreted signaling proteins is thought to limit the spatial extent of tissue differentiation during embryonic development. While it is possible to measure diffusion in vivo, specifically interfering with diffusion processes and testing diffusion models directly remains challenging. The development of genetically encoded nanobodies that bind specific proteins has provided the opportunity to alter protein localization and reduce protein mobility. Here, we extend the nanobody toolbox with a membrane-tethered low-affinity diffusion regulator that can be used to tune the effective diffusivity of extracellular molecules over an order of magnitude in living embryos. This opens new avenues for future applications to functionally interfere with diffusion-dependent processes.
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Affiliation(s)
- David Mörsdorf
- Friedrich Miescher Laboratory of the
Max Planck Society, Max-Planck-Ring 9, 72076 Tübingen, Germany
| | - Patrick Müller
- Friedrich Miescher Laboratory of the
Max Planck Society, Max-Planck-Ring 9, 72076 Tübingen, Germany
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34
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Santos‐Moreno J, Schaerli Y. Using Synthetic Biology to Engineer Spatial Patterns. ACTA ACUST UNITED AC 2018; 3:e1800280. [DOI: 10.1002/adbi.201800280] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 11/14/2018] [Indexed: 12/21/2022]
Affiliation(s)
- Javier Santos‐Moreno
- Department of Fundamental MicrobiologyUniversity of LausanneBiophore Building 1015 Lausanne Switzerland
| | - Yolanda Schaerli
- Department of Fundamental MicrobiologyUniversity of LausanneBiophore Building 1015 Lausanne Switzerland
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35
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Erkurt M. Emergence of form in embryogenesis. J R Soc Interface 2018; 15:20180454. [PMID: 30429261 PMCID: PMC6283983 DOI: 10.1098/rsif.2018.0454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 10/12/2018] [Indexed: 11/23/2022] Open
Abstract
The development of form in an embryo is the result of a series of topological and informational symmetry breakings. We introduce the vector-reaction-diffusion-drift (VRDD) system where the limit cycle of spatial dynamics is morphogen concentrations with Dirac delta-type distributions. This is fundamentally different from the Turing reaction-diffusion system, as VRDD generates system-wide broken symmetry. We developed 'fundamental forms' from spherical blastula with a single organizing axis (rotational symmetry), double axis (mirror symmetry) and triple axis (no symmetry operator in three dimensions). We then introduced dynamics for cell differentiation, where genetic regulatory states are modelled as a finite-state machine (FSM). The state switching of an FSM is based on local morphogen concentrations as epigenetic information that changes dynamically. We grow complicated forms hierarchically in spatial subdomains using the FSM model coupled with the VRDD system. Using our integrated simulation model with four layers (topological, physical, chemical and regulatory), we generated life-like forms such as hydra. Genotype-phenotype mapping was investigated with continuous and jump mutations. Our study can have applications in morphogenetic engineering, soft robotics and biomimetic design.
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Affiliation(s)
- Murat Erkurt
- Department of Mathematics, Centre for Complexity Science, Imperial College London, London SW7 2AZ, UK
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36
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Corepressor SMRT is required to maintain Hox transcriptional memory during somitogenesis. Proc Natl Acad Sci U S A 2018; 115:10381-10386. [PMID: 30254164 PMCID: PMC6187131 DOI: 10.1073/pnas.1809480115] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Retinoic acid (RA) is an important transcriptional regulator during both vertebrate and invertebrate body pattern formation. The Homeobox (Hox) gene family is activated by a gradient of RA formed along the length of the embryo at specific time points during fetal development. Generation of a genetically modified mouse harboring mutations in the SMRT repressor demonstrated that SMRT-dependent repression of retinoic acid receptor (RAR) is critical to establish and maintain the somitic Hox code and segmental identity during fetal development via epigenetic marking of target loci. Nuclear hormone receptors (NRs), such as retinoic acid receptors (RARs), play critical roles in vertebrate development and homeostasis by regulating target gene transcription. Their activity is controlled by ligand-dependent release of corepressors and subsequent recruitment of coactivators, but how these individual receptor modes contribute to development are unknown. Here, we show that mice carrying targeted knockin mutations in the corepressor Silencing Mediator of Retinoid and Thyroid hormone receptor (SMRT) that specifically disable SMRT function in NR signaling (SMRTmRID), display defects in cranial neural crest cell-derived structures and posterior homeotic transformations of axial vertebrae. SMRTmRID embryos show enhanced transcription of RAR targets including Hox loci, resulting in respecification of vertebral identities. Up-regulated histone acetylation and decreased H3K27 methylation are evident in the Hox loci whose somitic expression boundaries are rostrally shifted. Furthermore, enhanced recruitment of super elongation complex is evident in rapidly induced non-Pol II-paused targets in SMRTmRID embryonic stem cells. These results demonstrate that SMRT-dependent repression of RAR is critical to establish and maintain the somitic Hox code and segmental identity during fetal development via epigenetic marking of target loci.
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37
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Schaerli Y, Jiménez A, Duarte JM, Mihajlovic L, Renggli J, Isalan M, Sharpe J, Wagner A. Synthetic circuits reveal how mechanisms of gene regulatory networks constrain evolution. Mol Syst Biol 2018; 14:e8102. [PMID: 30201776 PMCID: PMC6129954 DOI: 10.15252/msb.20178102] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 08/15/2018] [Accepted: 08/15/2018] [Indexed: 12/22/2022] Open
Abstract
Phenotypic variation is the raw material of adaptive Darwinian evolution. The phenotypic variation found in organismal development is biased towards certain phenotypes, but the molecular mechanisms behind such biases are still poorly understood. Gene regulatory networks have been proposed as one cause of constrained phenotypic variation. However, most pertinent evidence is theoretical rather than experimental. Here, we study evolutionary biases in two synthetic gene regulatory circuits expressed in Escherichia coli that produce a gene expression stripe-a pivotal pattern in embryonic development. The two parental circuits produce the same phenotype, but create it through different regulatory mechanisms. We show that mutations cause distinct novel phenotypes in the two networks and use a combination of experimental measurements, mathematical modelling and DNA sequencing to understand why mutations bring forth only some but not other novel gene expression phenotypes. Our results reveal that the regulatory mechanisms of networks restrict the possible phenotypic variation upon mutation. Consequently, seemingly equivalent networks can indeed be distinct in how they constrain the outcome of further evolution.
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Affiliation(s)
- Yolanda Schaerli
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zürich, Switzerland
| | - Alba Jiménez
- Systems Biology Program, Centre for Genomic Regulation (CRG), Universitat Pompeu Fabra, Barcelona, Spain
| | - José M Duarte
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zürich, Switzerland
| | - Ljiljana Mihajlovic
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zürich, Switzerland
| | | | - Mark Isalan
- Department of Life Sciences, Imperial College London, London, UK
- Imperial College Centre for Synthetic Biology, Imperial College London, London, UK
| | - James Sharpe
- Systems Biology Program, Centre for Genomic Regulation (CRG), Universitat Pompeu Fabra, Barcelona, Spain
- Institucio Catalana de Recerca i Estudis Avancats (ICREA), Barcelona, Spain
- EMBL Barcelona European Molecular Biology Laboratory, Barcelona, Spain
| | - Andreas Wagner
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zürich, Switzerland
- The Swiss Institute of Bioinformatics, Lausanne, Switzerland
- The Santa Fe Institute, Santa Fe, NM, USA
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38
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Li C, Zhang L, Nie Q. Landscape reveals critical network structures for sharpening gene expression boundaries. BMC SYSTEMS BIOLOGY 2018; 12:67. [PMID: 29898720 PMCID: PMC6001026 DOI: 10.1186/s12918-018-0595-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 05/31/2018] [Indexed: 01/17/2023]
Abstract
Background Spatial pattern formation is a critical issue in developmental biology. Gene expression boundary sharpening has been observed from both experiments and modeling simulations. However, the mechanism to determine the sharpness of the boundary is not fully elucidated. Results We investigated the boundary sharpening resulted by three biological motifs, interacting with morphogens, and uncovered their probabilistic landscapes. The landscape view, along with calculated average switching time between attractors, provides a natural explanation for the boundary sharpening behavior relying on the noise induced gene state switchings. To possess boundary sharpening potential, a gene network needs to generate an asymmetric bistable state, i.e. one of the two stable states is less stable than the other. We found that the mutual repressed self-activation model displays more robust boundary sharpening ability against parameter perturbation, compared to the mutual repression or the self-activation model. This is supported by the results of switching time calculated from the landscape, which indicate that the mutual repressed self-activation model has shortest switching time, among three models. Additionally, introducing cross gradients of morphogens provides a more stable mechanism for the boundary sharpening of gene expression, due to a two-way switching mechanism. Conclusions Our results reveal the underlying principle for the gene expression boundary sharpening, and pave the way for the mechanistic understanding of cell fate decisions in the pattern formation processes of development. Electronic supplementary material The online version of this article (10.1186/s12918-018-0595-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Chunhe Li
- Shanghai Center for Mathematical Sciences, Fudan University, Shanghai, 200433, China. .,Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai, 200433, China.
| | - Lei Zhang
- Beijing International Center for Mathematical Research, Peking University, Beijing, 100871, China. .,Center for Quantitative Biology, Peking University, Beijing, 100871, China.
| | - Qing Nie
- Department of Mathematics, University of California, Irvine, 92697, USA. .,Center for Complex Biological Systems, University of California, Irvine, 92697, USA.
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39
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Kim H, Sayama H. How Criticality of Gene Regulatory Networks Affects the Resulting Morphogenesis under Genetic Perturbations. ARTIFICIAL LIFE 2018; 24:85-105. [PMID: 29664344 DOI: 10.1162/artl_a_00262] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Whereas the relationship between criticality of gene regulatory networks (GRNs) and dynamics of GRNs at a single-cell level has been vigorously studied, the relationship between the criticality of GRNs and system properties at a higher level has not been fully explored. Here we aim at revealing a potential role of criticality of GRNs in morphogenesis, which is hard to uncover through the single-cell-level studies, especially from an evolutionary viewpoint. Our model simulated the growth of a cell population from a single seed cell. All the cells were assumed to have identical intracellular GRNs. We induced genetic perturbations to the GRN of the seed cell by adding, deleting, or switching a regulatory link between a pair of genes. From numerical simulations, we found that the criticality of GRNs facilitated the formation of nontrivial morphologies when the GRNs were critical in the presence of the evolutionary perturbations. Moreover, the criticality of GRNs produced topologically homogeneous cell clusters by adjusting the spatial arrangements of cells, which led to the formation of nontrivial morphogenetic patterns. Our findings correspond to an epigenetic viewpoint that heterogeneous and complex features emerge from homogeneous and less complex components through the interactions among them. Thus, our results imply that highly structured tissues or organs in morphogenesis of multicellular organisms might stem from the criticality of GRNs.
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Affiliation(s)
- Hyobin Kim
- Department of Systems Science and Industrial Engineering, Center for Collective Dynamics of Complex Systems, Binghamton University.
| | - Hiroki Sayama
- Department of Systems Science and Industrial Engineering, Center for Collective Dynamics of Complex Systems, Binghamton University. (HS)
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40
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Lin J, Yue Z. Coupling of apical-basal polarity and PCP to interpret the Wnt signaling gradient and orient feather branch. Development 2018; 145:dev.162792. [DOI: 10.1242/dev.162792] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 07/31/2018] [Indexed: 12/31/2022]
Abstract
To sense a global directional cue and orient cell growth is crucial in tissue morphogenesis. An anterior-posterior gradient of Wnt signaling controls the helical growth of feather branches (barbs), thus the formation of bilateral feathers. However, it remains unclear how the keratinocytes sense this gradient and orient barb growth. Here we show that due to feather branching, the global Wnt gradient is subdivided into periodic barbs. Within each barb, the anterior barbule plate cells tilt before the posterior cells. The core PCP gene Prickle1 is involved, as knockdown of its expression resulted in no cell shape change and no barb tilting. Furthermore, perturbation of the Wnt gradient leads to diffusive Prickle1 expression, and loss of barb orientation. Finally, the asymmetric distribution of Wnt6/Fzd10 is coordinated by the apical-basal polarity of the barbule plate keratinocytes, which is in turn regulated by the Par3/aPKC machinery. Our data elucidate a new mechanism through which the global Wnt signaling gradient is interpreted locally to construct complex spatial forms.
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Affiliation(s)
- Jianqiong Lin
- Institute of Life Sciences, Fuzhou University, Fuzhou, Fujian, China
| | - Zhicao Yue
- Institute of Life Sciences, Fuzhou University, Fuzhou, Fujian, China
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41
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Minuth WW. Concepts for a therapeutic prolongation of nephrogenesis in preterm and low-birth-weight babies must correspond to structural-functional properties in the nephrogenic zone. Mol Cell Pediatr 2017; 4:12. [PMID: 29218481 PMCID: PMC5721096 DOI: 10.1186/s40348-017-0078-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 11/20/2017] [Indexed: 12/30/2022] Open
Abstract
Numerous investigations are dealing with anlage of the mammalian kidney and primary development of nephrons. However, only few information is available about the last steps in kidney development leading at birth to a downregulation of morphogen activity in the nephrogenic zone and to a loss of stem cell niches aligned beyond the organ capsule. Surprisingly, these natural changes in the developmental program display similarities to processes occurring in the kidneys of preterm and low-birth-weight babies. Although those babies are born at a time with a principally intact nephrogenic zone and active niches, a high proportion of them suffers on impairment of nephrogenesis resulting in oligonephropathy, formation of atypical glomeruli, and immaturity of parenchyma. The setting points out that up to date not identified noxae in the nephrogenic zone hamper primary steps of parenchyma development. In this situation, a possible therapeutic aim is to prolong nephrogenesis by medications. However, actual data provide information that administration of drugs is problematic due to an unexpectedly complex microanatomy of the nephrogenic zone, in niches so far not considered textured extracellular matrix and peculiar contacts between mesenchymal cell projections and epithelial stem cells via tunneling nanotubes. Thus, it remains to be figured out whether disturbance of morphogen signaling altered synthesis of extracellular matrix, disturbed cell-to-cell contacts, or modified interstitial fluid impair nephrogenic activity. Due to most unanswered questions, search for eligible drugs prolonging nephrogenesis and their reliable administration is a special challenge for the future.
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Affiliation(s)
- Will W Minuth
- Institute of Anatomy, University of Regensburg, 93053, Regensburg, Germany.
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Andl T, Zhang Y. Reaping Wnt after calming Hippo: Wnt and Hippo signaling cross paths in lung cancer. J Thorac Dis 2017; 9:4174-4179. [PMID: 29268463 DOI: 10.21037/jtd.2017.10.29] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Thomas Andl
- Burnett School of Biological Sciences, University of Central Florida, Orlando, FL, USA
| | - Yuhang Zhang
- Division of Pharmaceutical Sciences, College of Pharmacy, University of Cincinnati, Cincinnati, OH, USA
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43
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Abstract
Immune cells communicate using cytokine signals, but the quantitative rules of this communication aren't clear. In this issue of Immunity, Oyler-Yaniv et al. (2017) suggest that the distribution of a cytokine within a lymphatic organ is primarily governed by the local density of cells consuming it.
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Affiliation(s)
- Frank P Assen
- Institute of Science and Technology Austria (IST Austria), 3400 Klosterneuburg, Austria
| | - Michael Sixt
- Institute of Science and Technology Austria (IST Austria), 3400 Klosterneuburg, Austria.
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44
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Auxin minimum triggers the developmental switch from cell division to cell differentiation in the Arabidopsis root. Proc Natl Acad Sci U S A 2017; 114:E7641-E7649. [PMID: 28831001 DOI: 10.1073/pnas.1705833114] [Citation(s) in RCA: 157] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In multicellular organisms, a stringent control of the transition between cell division and differentiation is crucial for correct tissue and organ development. In the Arabidopsis root, the boundary between dividing and differentiating cells is positioned by the antagonistic interaction of the hormones auxin and cytokinin. Cytokinin affects polar auxin transport, but how this impacts the positional information required to establish this tissue boundary, is still unknown. By combining computational modeling with molecular genetics, we show that boundary formation is dependent on cytokinin's control on auxin polar transport and degradation. The regulation of both processes shapes the auxin profile in a well-defined auxin minimum. This auxin minimum positions the boundary between dividing and differentiating cells, acting as a trigger for this developmental transition, thus controlling meristem size.
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45
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Janes KA, Chandran PL, Ford RM, Lazzara MJ, Papin JA, Peirce SM, Saucerman JJ, Lauffenburger DA. An engineering design approach to systems biology. Integr Biol (Camb) 2017; 9:574-583. [PMID: 28590470 PMCID: PMC6534349 DOI: 10.1039/c7ib00014f] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Measuring and modeling the integrated behavior of biomolecular-cellular networks is central to systems biology. Over several decades, systems biology has been shaped by quantitative biologists, physicists, mathematicians, and engineers in different ways. However, the basic and applied versions of systems biology are not typically distinguished, which blurs the separate aspirations of the field and its potential for real-world impact. Here, we articulate an engineering approach to systems biology, which applies educational philosophy, engineering design, and predictive models to solve contemporary problems in an age of biomedical Big Data. A concerted effort to train systems bioengineers will provide a versatile workforce capable of tackling the diverse challenges faced by the biotechnological and pharmaceutical sectors in a modern, information-dense economy.
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Affiliation(s)
- Kevin A Janes
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA.
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46
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Johnson HE, Goyal Y, Pannucci NL, Schüpbach T, Shvartsman SY, Toettcher JE. The Spatiotemporal Limits of Developmental Erk Signaling. Dev Cell 2017; 40:185-192. [PMID: 28118601 DOI: 10.1016/j.devcel.2016.12.002] [Citation(s) in RCA: 128] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 10/30/2016] [Accepted: 12/01/2016] [Indexed: 11/28/2022]
Abstract
Animal development is characterized by signaling events that occur at precise locations and times within the embryo, but determining when and where such precision is needed for proper embryogenesis has been a long-standing challenge. Here we address this question for extracellular signal regulated kinase (Erk) signaling, a key developmental patterning cue. We describe an optogenetic system for activating Erk with high spatiotemporal precision in vivo. Implementing this system in Drosophila, we find that embryogenesis is remarkably robust to ectopic Erk signaling, except from 1 to 4 hr post-fertilization, when perturbing the spatial extent of Erk pathway activation leads to dramatic disruptions of patterning and morphogenesis. Later in development, the effects of ectopic signaling are buffered, at least in part, by combinatorial mechanisms. Our approach can be used to systematically probe the differential contributions of the Ras/Erk pathway and concurrent signals, leading to a more quantitative understanding of developmental signaling.
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Affiliation(s)
- Heath E Johnson
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Yogesh Goyal
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA; Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Nicole L Pannucci
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Trudi Schüpbach
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Stanislav Y Shvartsman
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA; Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Jared E Toettcher
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
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47
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The Slow Mobility of the ParA Partitioning Protein Underlies Its Steady-State Patterning in Caulobacter. Biophys J 2017; 110:2790-2799. [PMID: 27332137 DOI: 10.1016/j.bpj.2016.05.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 04/29/2016] [Accepted: 05/06/2016] [Indexed: 01/04/2023] Open
Abstract
In bacteria, ParABS systems mediate intracellular transport of various cargos, including chromosomal regions in Caulobacter crescentus. Transport of the ParB/parS partition complex requires the DNA-binding activity of ParA, which transiently tethers the partition complex during translocation. In C. crescentus, the directionality of the transport is set up by a gradient of ParA whose concentration gradually increases from one end of the cell (old pole) to the other (new pole). Importantly, this ParA gradient is already observed before DNA replication and segregation are initiated when the partition complex is anchored at the old pole. How such micron-scale ParA pattern is established and maintained before the initiation of chromosome segregation has not been experimentally established. Although the stimulation of ParA ATPase activity by the localized ParB/parS partition complex is thought to be involved, this activity alone cannot quantitatively describe the ParA pattern observed inside cells. Instead, our experimental and theoretical study shows that the missing key component for achieving the experimentally observed steady-state ParA patterning is the slow mobility of ParA dimers (D ∼10(-3)μm(2)/s) due to intermittent DNA binding. Our model recapitulates the entire steady-state ParA distribution observed experimentally, including the shape of the gradient as well as ParA accumulation at the location of the partition complex. Stochastic simulations suggest that cell-to-cell variability in ParA pattern is due to the low ParA copy number in C. crescentus cells. The model also accounts for an apparent exclusion of ParA from regions with small spacing between partition complexes observed in filamentous cells. Collectively, our work demonstrates that in addition to its function in mediating transport, the conserved DNA-binding property of ParA has a critical function before DNA segregation by setting up a ParA pattern required for transport directionality.
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48
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Davidson LA. Mechanical design in embryos: mechanical signalling, robustness and developmental defects. Philos Trans R Soc Lond B Biol Sci 2017; 372:20150516. [PMID: 28348252 PMCID: PMC5379024 DOI: 10.1098/rstb.2015.0516] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/04/2016] [Indexed: 12/18/2022] Open
Abstract
Embryos are shaped by the precise application of force against the resistant structures of multicellular tissues. Forces may be generated, guided and resisted by cells, extracellular matrix, interstitial fluids, and how they are organized and bound within the tissue's architecture. In this review, we summarize our current thoughts on the multiple roles of mechanics in direct shaping, mechanical signalling and robustness of development. Genetic programmes of development interact with environmental cues to direct the composition of the early embryo and endow cells with active force production. Biophysical advances now provide experimental tools to measure mechanical resistance and collective forces during morphogenesis and are allowing integration of this field with studies of signalling and patterning during development. We focus this review on concepts that highlight this integration, and how the unique contributions of mechanical cues and gradients might be tested side by side with conventional signalling systems. We conclude with speculation on the integration of large-scale programmes of development, and how mechanical responses may ensure robust development and serve as constraints on programmes of tissue self-assembly.This article is part of the themed issue 'Systems morphodynamics: understanding the development of tissue hardware'.
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Affiliation(s)
- Lance A Davidson
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Department of Developmental Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
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49
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Sanial M, Bécam I, Hofmann L, Behague J, Argüelles C, Gourhand V, Bruzzone L, Holmgren RA, Plessis A. Dose-dependent transduction of Hedgehog relies on phosphorylation-based feedback between the G-protein-coupled receptor Smoothened and the kinase Fused. Development 2017; 144:1841-1850. [PMID: 28360132 DOI: 10.1242/dev.144782] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 03/20/2017] [Indexed: 12/28/2022]
Abstract
Smoothened (SMO) is a G-protein-coupled receptor-related protein required for the transduction of Hedgehog (HH). The HH gradient leads to graded phosphorylation of SMO, mainly by the PKA and CKI kinases. How thresholds in HH morphogen regulate SMO to promote switch-like transcriptional responses is a central unsolved issue. Using the wing imaginal disc model in Drosophila, we identified new SMO phosphosites that enhance the effects of the PKA/CKI kinases on SMO accumulation, its localization at the plasma membrane and its activity. Surprisingly, phosphorylation at these sites is induced by the kinase Fused (FU), a known downstream effector of SMO. In turn, activation of SMO induces FU to act on its downstream targets. Overall, our data provide evidence for a SMO/FU positive regulatory loop nested within a multikinase phosphorylation cascade. We propose that this complex interplay amplifies signaling above a threshold that allows high HH signaling.
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Affiliation(s)
- Matthieu Sanial
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, Paris F-75205, France
| | - Isabelle Bécam
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, Paris F-75205, France
| | - Line Hofmann
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, Paris F-75205, France
| | - Julien Behague
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, Paris F-75205, France
| | - Camilla Argüelles
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, Paris F-75205, France
| | - Vanessa Gourhand
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, Paris F-75205, France
| | - Lucia Bruzzone
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, Paris F-75205, France
| | - Robert A Holmgren
- Department of Molecular Bioscience, Northwestern University, Evanston, IL 60208-3500, USA
| | - Anne Plessis
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, Paris F-75205, France
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50
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Geometry can provide long-range mechanical guidance for embryogenesis. PLoS Comput Biol 2017; 13:e1005443. [PMID: 28346461 PMCID: PMC5386319 DOI: 10.1371/journal.pcbi.1005443] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 04/10/2017] [Accepted: 03/03/2017] [Indexed: 12/17/2022] Open
Abstract
Downstream of gene expression, effectors such as the actomyosin contractile machinery drive embryo morphogenesis. During Drosophila embryonic axis extension, actomyosin has a specific planar-polarised organisation, which is responsible for oriented cell intercalation. In addition to these cell rearrangements, cell shape changes also contribute to tissue deformation. While cell-autonomous dynamics are well described, understanding the tissue-scale behaviour challenges us to solve the corresponding mechanical problem at the scale of the whole embryo, since mechanical resistance of all neighbouring epithelia will feedback on individual cells. Here we propose a novel numerical approach to compute the whole-embryo dynamics of the actomyosin-rich apical epithelial surface. We input in the model specific patterns of actomyosin contractility, such as the planar-polarisation of actomyosin in defined ventro-lateral regions of the embryo. Tissue strain rates and displacements are then predicted over the whole embryo surface according to the global balance of stresses and the material behaviour of the epithelium. Epithelia are modelled using a rheological law that relates the rate of deformation to the local stresses and actomyosin anisotropic contractility. Predicted flow patterns are consistent with the cell flows observed when imaging Drosophila axis extension in toto, using light sheet microscopy. The agreement between model and experimental data indicates that the anisotropic contractility of planar-polarised actomyosin in the ventro-lateral germband tissue can directly cause the tissue-scale deformations of the whole embryo. The three-dimensional mechanical balance is dependent on the geometry of the embryo, whose curved surface is taken into account in the simulations. Importantly, we find that to reproduce experimental flows, the model requires the presence of the cephalic furrow, a fold located anteriorly of the extending tissues. The presence of this geometric feature, through the global mechanical balance, guides the flow and orients extension towards the posterior end.
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