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Kumar N, Mim MS, Dowling A, Zartman JJ. Reverse engineering morphogenesis through Bayesian optimization of physics-based models. NPJ Syst Biol Appl 2024; 10:49. [PMID: 38714708 PMCID: PMC11076624 DOI: 10.1038/s41540-024-00375-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 04/17/2024] [Indexed: 05/10/2024] Open
Abstract
Morphogenetic programs coordinate cell signaling and mechanical interactions to shape organs. In systems and synthetic biology, a key challenge is determining optimal cellular interactions for predicting organ shape, size, and function. Physics-based models defining the subcellular force distribution facilitate this, but it is challenging to calibrate parameters in these models from data. To solve this inverse problem, we created a Bayesian optimization framework to determine the optimal cellular force distribution such that the predicted organ shapes match the experimentally observed organ shapes. This integrative framework employs Gaussian Process Regression, a non-parametric kernel-based probabilistic machine learning modeling paradigm, to learn the mapping functions relating to the morphogenetic programs that maintain the final organ shape. We calibrated and tested the method on Drosophila wing imaginal discs to study mechanisms that regulate epithelial processes ranging from development to cancer. The parameter estimation framework successfully infers the underlying changes in core parameters needed to match simulation data with imaging data of wing discs perturbed with collagenase. The computational pipeline identifies distinct parameter sets mimicking wild-type shapes. It enables a global sensitivity analysis to support the regulation of actomyosin contractility and basal ECM stiffness to generate and maintain the curved shape of the wing imaginal disc. The optimization framework, combined with experimental imaging, identified that Piezo, a mechanosensitive ion channel, impacts fold formation by regulating the apical-basal balance of actomyosin contractility and elasticity of ECM. This workflow is extensible toward reverse-engineering morphogenesis across organ systems and for real-time control of complex multicellular systems.
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Affiliation(s)
- Nilay Kumar
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Mayesha Sahir Mim
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN, 46556, USA
- Bioengineering Graduate Program, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Alexander Dowling
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Jeremiah J Zartman
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN, 46556, USA.
- Bioengineering Graduate Program, University of Notre Dame, Notre Dame, IN, 46556, USA.
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2
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Kumar N, Rangel Ambriz J, Tsai K, Mim MS, Flores-Flores M, Chen W, Zartman JJ, Alber M. Balancing competing effects of tissue growth and cytoskeletal regulation during Drosophila wing disc development. Nat Commun 2024; 15:2477. [PMID: 38509115 PMCID: PMC10954670 DOI: 10.1038/s41467-024-46698-7] [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: 09/28/2022] [Accepted: 03/06/2024] [Indexed: 03/22/2024] Open
Abstract
How a developing organ robustly coordinates the cellular mechanics and growth to reach a final size and shape remains poorly understood. Through iterations between experiments and model simulations that include a mechanistic description of interkinetic nuclear migration, we show that the local curvature, height, and nuclear positioning of cells in the Drosophila wing imaginal disc are defined by the concurrent patterning of actomyosin contractility, cell-ECM adhesion, ECM stiffness, and interfacial membrane tension. We show that increasing cell proliferation via different growth-promoting pathways results in two distinct phenotypes. Triggering proliferation through insulin signaling increases basal curvature, but an increase in growth through Dpp signaling and Myc causes tissue flattening. These distinct phenotypic outcomes arise from differences in how each growth pathway regulates the cellular cytoskeleton, including contractility and cell-ECM adhesion. The coupled regulation of proliferation and cytoskeletal regulators is a general strategy to meet the multiple context-dependent criteria defining tissue morphogenesis.
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Affiliation(s)
- Nilay Kumar
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN, USA
| | - Jennifer Rangel Ambriz
- Department of Mathematics, University of California, Riverside, CA, USA
- Interdisciplinary Center for Quantitative Modeling in Biology, University of California, Riverside, CA, USA
| | - Kevin Tsai
- Department of Mathematics, University of California, Riverside, CA, USA
- Interdisciplinary Center for Quantitative Modeling in Biology, University of California, Riverside, CA, USA
| | - Mayesha Sahir Mim
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN, USA
| | - Marycruz Flores-Flores
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN, USA
| | - Weitao Chen
- Department of Mathematics, University of California, Riverside, CA, USA
- Interdisciplinary Center for Quantitative Modeling in Biology, University of California, Riverside, CA, USA
| | - Jeremiah J Zartman
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN, USA.
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA.
| | - Mark Alber
- Department of Mathematics, University of California, Riverside, CA, USA.
- Interdisciplinary Center for Quantitative Modeling in Biology, University of California, Riverside, CA, USA.
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Gou J, Zhang T, Othmer HG. The Interaction of Mechanics and the Hippo Pathway in Drosophila melanogaster. Cancers (Basel) 2023; 15:4840. [PMID: 37835534 PMCID: PMC10571775 DOI: 10.3390/cancers15194840] [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: 08/17/2023] [Revised: 09/10/2023] [Accepted: 09/15/2023] [Indexed: 10/15/2023] Open
Abstract
Drosophila melanogaster has emerged as an ideal system for studying the networks that control tissue development and homeostasis and, given the similarity of the pathways involved, controlled and uncontrolled growth in mammalian systems. The signaling pathways used in patterning the Drosophila wing disc are well known and result in the emergence of interaction of these pathways with the Hippo signaling pathway, which plays a central role in controlling cell proliferation and apoptosis. Mechanical effects are another major factor in the control of growth, but far less is known about how they exert their control. Herein, we develop a mathematical model that integrates the mechanical interactions between cells, which occur via adherens and tight junctions, with the intracellular actin network and the Hippo pathway so as to better understand cell-autonomous and non-autonomous control of growth in response to mechanical forces.
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Affiliation(s)
- Jia Gou
- Department of Mathematics, University of California, Riverside, CA 92507, USA;
| | - Tianhao Zhang
- School of Mathematics, University of Minnesota, Minneapolis, MN 55455, USA;
| | - Hans G. Othmer
- School of Mathematics, University of Minnesota, Minneapolis, MN 55455, USA;
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Schmitter C, Di-Luoffo M, Guillermet-Guibert J. Transducing compressive forces into cellular outputs in cancer and beyond. Life Sci Alliance 2023; 6:e202201862. [PMID: 37364915 PMCID: PMC10292664 DOI: 10.26508/lsa.202201862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 06/13/2023] [Accepted: 06/13/2023] [Indexed: 06/28/2023] Open
Abstract
In living organisms, cells sense mechanical forces (shearing, tensile, and compressive) and respond to those physical cues through a process called mechanotransduction. This process includes the simultaneous activation of biochemical signaling pathways. Recent studies mostly on human cells revealed that compressive forces selectively modulate a wide range of cell behavior, both in compressed and in neighboring less compressed cells. Besides participating in tissue homeostasis such as bone healing, compression is also involved in pathologies, including intervertebral disc degeneration or solid cancers. In this review, we will summarize the current scattered knowledge of compression-induced cell signaling pathways and their subsequent cellular outputs, both in physiological and pathological conditions, such as solid cancers.
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Affiliation(s)
- Céline Schmitter
- CRCT, Université de Toulouse, Inserm, CNRS, Université Toulouse-III Paul Sabatier, Centre de Recherches en Cancérologie de Toulouse, Toulouse, France
- Labex Toucan, Toulouse, France
- Master de Biologie, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
| | - Mickaël Di-Luoffo
- CRCT, Université de Toulouse, Inserm, CNRS, Université Toulouse-III Paul Sabatier, Centre de Recherches en Cancérologie de Toulouse, Toulouse, France
- Labex Toucan, Toulouse, France
| | - Julie Guillermet-Guibert
- CRCT, Université de Toulouse, Inserm, CNRS, Université Toulouse-III Paul Sabatier, Centre de Recherches en Cancérologie de Toulouse, Toulouse, France
- Labex Toucan, Toulouse, France
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Kumar N, Dowling A, Zartman J. Reverse engineering morphogenesis through Bayesian optimization of physics-based models. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.21.553928. [PMID: 37662294 PMCID: PMC10473585 DOI: 10.1101/2023.08.21.553928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Morphogenetic programs direct the cell signaling and nonlinear mechanical interactions between multiple cell types and tissue layers to define organ shape and size. A key challenge for systems and synthetic biology is determining optimal combinations of intra- and inter-cellular interactions to predict an organ's shape, size, and function. Physics-based mechanistic models that define the subcellular force distribution facilitate this, but it is extremely challenging to calibrate parameters in these models from data. To solve this inverse problem, we created a Bayesian optimization framework to determine the optimal cellular force distribution such that the predicted organ shapes match the desired organ shapes observed within the experimental imaging data. This integrative framework employs Gaussian Process Regression (GPR), a non-parametric kernel-based probabilistic machine learning modeling paradigm, to learn the mapping functions relating to the morphogenetic programs that generate and maintain the final organ shape. We calibrated and tested the method on cross-sections of Drosophila wing imaginal discs, a highly informative model organ system, to study mechanisms that regulate epithelial processes that range from development to cancer. As a specific test case, the parameter estimation framework successfully infers the underlying changes in core parameters needed to match simulation data with time series imaging data of wing discs perturbed with collagenase. Unexpectedly, the framework also identifies multiple distinct parameter sets that generate shapes similar to wild-type organ shapes. This platform enables an efficient, global sensitivity analysis to support the necessity of both actomyosin contractility and basal ECM stiffness to generate and maintain the curved shape of the wing imaginal disc. The optimization framework, combined with fixed tissue imaging, identified that Piezo, a mechanosensitive ion channel, impacts fold formation by regulating the apical-basal balance of actomyosin contractility and elasticity of ECM. This framework is extensible toward reverse-engineering the morphogenesis of any organ system and can be utilized in real-time control of complex multicellular systems.
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Velagala V, Soundarrajan DK, Unger MF, Gazzo D, Kumar N, Li J, Zartman J. The multimodal action of G alpha q in coordinating growth and homeostasis in the Drosophila wing imaginal disc. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.08.523049. [PMID: 36711848 PMCID: PMC9881979 DOI: 10.1101/2023.01.08.523049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Background G proteins mediate cell responses to various ligands and play key roles in organ development. Dysregulation of G-proteins or Ca 2+ signaling impacts many human diseases and results in birth defects. However, the downstream effectors of specific G proteins in developmental regulatory networks are still poorly understood. Methods We employed the Gal4/UAS binary system to inhibit or overexpress Gαq in the wing disc, followed by phenotypic analysis. Immunohistochemistry and next-gen RNA sequencing identified the downstream effectors and the signaling cascades affected by the disruption of Gαq homeostasis. Results Here, we characterized how the G protein subunit Gαq tunes the size and shape of the wing in the larval and adult stages of development. Downregulation of Gαq in the wing disc reduced wing growth and delayed larval development. Gαq overexpression is sufficient to promote global Ca 2+ waves in the wing disc with a concomitant reduction in the Drosophila final wing size and a delay in pupariation. The reduced wing size phenotype is further enhanced when downregulating downstream components of the core Ca 2+ signaling toolkit, suggesting that downstream Ca 2+ signaling partially ameliorates the reduction in wing size. In contrast, Gαq -mediated pupariation delay is rescued by inhibition of IP 3 R, a key regulator of Ca 2+ signaling. This suggests that Gαq regulates developmental phenotypes through both Ca 2+ -dependent and Ca 2+ -independent mechanisms. RNA seq analysis shows that disruption of Gαq homeostasis affects nuclear hormone receptors, JAK/STAT pathway, and immune response genes. Notably, disruption of Gαq homeostasis increases expression levels of Dilp8, a key regulator of growth and pupariation timing. Conclusion Gαq activity contributes to cell size regulation and wing metamorphosis. Disruption to Gαq homeostasis in the peripheral wing disc organ delays larval development through ecdysone signaling inhibition. Overall, Gαq signaling mediates key modules of organ size regulation and epithelial homeostasis through the dual action of Ca 2+ -dependent and independent mechanisms.
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Kumar N, Huizar FJ, Farfán-Pira KJ, Brodskiy PA, Soundarrajan DK, Nahmad M, Zartman JJ. MAPPER: An Open-Source, High-Dimensional Image Analysis Pipeline Unmasks Differential Regulation of Drosophila Wing Features. Front Genet 2022; 13:869719. [PMID: 35480325 PMCID: PMC9035675 DOI: 10.3389/fgene.2022.869719] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 03/03/2022] [Indexed: 11/13/2022] Open
Abstract
Phenomics requires quantification of large volumes of image data, necessitating high throughput image processing approaches. Existing image processing pipelines for Drosophila wings, a powerful genetic model for studying the underlying genetics for a broad range of cellular and developmental processes, are limited in speed, precision, and functional versatility. To expand on the utility of the wing as a phenotypic screening system, we developed MAPPER, an automated machine learning-based pipeline that quantifies high-dimensional phenotypic signatures, with each dimension quantifying a unique morphological feature of the Drosophila wing. MAPPER magnifies the power of Drosophila phenomics by rapidly quantifying subtle phenotypic differences in sample populations. We benchmarked MAPPER’s accuracy and precision in replicating manual measurements to demonstrate its widespread utility. The morphological features extracted using MAPPER reveal variable sexual dimorphism across Drosophila species and unique underlying sex-specific differences in morphogen signaling in male and female wings. Moreover, the length of the proximal-distal axis across the species and sexes shows a conserved scaling relationship with respect to the wing size. In sum, MAPPER is an open-source tool for rapid, high-dimensional analysis of large imaging datasets. These high-content phenomic capabilities enable rigorous and systematic identification of genotype-to-phenotype relationships in a broad range of screening and drug testing applications and amplify the potential power of multimodal genomic approaches.
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Affiliation(s)
- Nilay Kumar
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN, United States
| | - Francisco J. Huizar
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN, United States
| | - Keity J. Farfán-Pira
- Department of Physiology, Biophysics, and Neurosciences, Center for Research and Advanced Studies of the National Polytechnical Institute (Cinvestav), Mexico City, Mexico
| | - Pavel A. Brodskiy
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN, United States
| | - Dharsan K. Soundarrajan
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN, United States
| | - Marcos Nahmad
- Department of Physiology, Biophysics, and Neurosciences, Center for Research and Advanced Studies of the National Polytechnical Institute (Cinvestav), Mexico City, Mexico
| | - Jeremiah J. Zartman
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN, United States
- *Correspondence: Jeremiah J. Zartman,
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8
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From spikes to intercellular waves: Tuning intercellular calcium signaling dynamics modulates organ size control. PLoS Comput Biol 2021; 17:e1009543. [PMID: 34723960 PMCID: PMC8601605 DOI: 10.1371/journal.pcbi.1009543] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 11/18/2021] [Accepted: 10/07/2021] [Indexed: 12/18/2022] Open
Abstract
Information flow within and between cells depends significantly on calcium (Ca2+) signaling dynamics. However, the biophysical mechanisms that govern emergent patterns of Ca2+ signaling dynamics at the organ level remain elusive. Recent experimental studies in developing Drosophila wing imaginal discs demonstrate the emergence of four distinct patterns of Ca2+ activity: Ca2+ spikes, intercellular Ca2+ transients, tissue-level Ca2+ waves, and a global “fluttering” state. Here, we used a combination of computational modeling and experimental approaches to identify two different populations of cells within tissues that are connected by gap junction proteins. We term these two subpopulations “initiator cells,” defined by elevated levels of Phospholipase C (PLC) activity, and “standby cells,” which exhibit baseline activity. We found that the type and strength of hormonal stimulation and extent of gap junctional communication jointly determine the predominate class of Ca2+ signaling activity. Further, single-cell Ca2+ spikes are stimulated by insulin, while intercellular Ca2+ waves depend on Gαq activity. Our computational model successfully reproduces how the dynamics of Ca2+ transients varies during organ growth. Phenotypic analysis of perturbations to Gαq and insulin signaling support an integrated model of cytoplasmic Ca2+ as a dynamic reporter of overall tissue growth. Further, we show that perturbations to Ca2+ signaling tune the final size of organs. This work provides a platform to further study how organ size regulation emerges from the crosstalk between biochemical growth signals and heterogeneous cell signaling states. Calcium (Ca2+) is a universal second messenger that regulates a myriad of cellular processes such as cell division, cell proliferation and apoptosis. Multiple patterns of Ca2+ signaling including single-cell spikes, multicellular Ca2+ transients, large-scale Ca2+ waves, and global “fluttering” have been observed in epithelial systems during organ development. Key molecular players and biophysical mechanisms involved in formation of these patterns during organ development are not well understood. In this work, we developed a generalized multicellular model of Ca2+ that captures all the key categories of Ca2+ activity as a function of key hormonal signals. Integration of model predictions and experiments reveals two subclasses of cell populations and demonstrates that Ca2+ signaling activity at the organ scale is defined by a general decrease in gap junction communication as an organ grows. Our experiments also reveal that a “goldilocks zone” of optimal Ca2+ activity is required to achieve optimal growth at the organ level.
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9
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Dagenais P, Blanchoud S, Pury D, Pfefferli C, Aegerter-Wilmsen T, Aegerter CM, Jaźwińska A. Hydrodynamic stress and phenotypic plasticity of the zebrafish regenerating fin. J Exp Biol 2021; 224:271142. [PMID: 34338301 DOI: 10.1242/jeb.242309] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 06/14/2021] [Indexed: 01/23/2023]
Abstract
Understanding how extrinsic factors modulate genetically encoded information to produce a specific phenotype is of prime scientific interest. In particular, the feedback mechanism between abiotic forces and locomotory organs during morphogenesis to achieve efficient movement is a highly relevant example of such modulation. The study of this developmental process can provide unique insights on the transduction of cues at the interface between physics and biology. Here, we take advantage of the natural ability of adult zebrafish to regenerate their amputated fins to assess its morphogenic plasticity upon external modulations. Using a variety of surgical and chemical treatments, we could induce phenotypic responses to the structure of the fin. Through the ablation of specific rays in regenerating caudal fins, we generated artificially narrowed appendages in which the fin cleft depth and the positioning of rays bifurcations were perturbed compared with normal regenerates. To dissect the role of mechanotransduction in this process, we investigated the patterns of hydrodynamic forces acting on the surface of a zebrafish fin during regeneration by using particle tracking velocimetry on a range of biomimetic hydrofoils. This experimental approach enabled us to quantitatively compare hydrodynamic stress distributions over flapping fins of varying sizes and shapes. As a result, viscous shear stress acting on the distal margin of regenerating fins and the resulting internal tension are proposed as suitable signals for guiding the regulation of ray growth dynamics and branching pattern. Our findings suggest that mechanical forces are involved in the fine-tuning of the locomotory organ during fin morphogenesis.
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Affiliation(s)
- Paule Dagenais
- Physik-Institut, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Simon Blanchoud
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - David Pury
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Catherine Pfefferli
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Tinri Aegerter-Wilmsen
- Department of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Christof M Aegerter
- Physik-Institut, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.,Department of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Anna Jaźwińska
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
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Nematbakhsh A, Levis M, Kumar N, Chen W, Zartman JJ, Alber M. Epithelial organ shape is generated by patterned actomyosin contractility and maintained by the extracellular matrix. PLoS Comput Biol 2020; 16:e1008105. [PMID: 32817654 PMCID: PMC7480841 DOI: 10.1371/journal.pcbi.1008105] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 09/09/2020] [Accepted: 06/30/2020] [Indexed: 01/13/2023] Open
Abstract
Epithelial sheets define organ architecture during development. Here, we employed an iterative multiscale computational modeling and quantitative experimental approach to decouple direct and indirect effects of actomyosin-generated forces, nuclear positioning, extracellular matrix, and cell-cell adhesion in shaping Drosophila wing imaginal discs. Basally generated actomyosin forces generate epithelial bending of the wing disc pouch. Surprisingly, acute pharmacological inhibition of ROCK-driven actomyosin contractility does not impact the maintenance of tissue height or curved shape. Computational simulations show that ECM tautness provides only a minor contribution to modulating tissue shape. Instead, passive ECM pre-strain serves to maintain the shape independent from actomyosin contractility. These results provide general insight into how the subcellular forces are generated and maintained within individual cells to induce tissue curvature. Thus, the results suggest an important design principle of separable contributions from ECM prestrain and actomyosin tension during epithelial organogenesis and homeostasis. The regulation and maintenance of an organ’s shape is a major outstanding problem in developmental biology. An iterative approach combining multiscale computational modelling and quantitative experimental approach was used to decouple direct and indirect roles of subcellular mechanical forces, nuclear positioning, and extracellular matrix in shaping the major axis of the wing pouch during the larval stage in fruit flies, which serves as a prototypical system for investigating epithelial morphogenesis. The research findings in this paper demonstrate that subcellular mechanical forces can effectively generate the curved tissue profile, while extracellular matrix is necessary for preserving the bent shape even in the absence of subcellular mechanical forces once the shape is generated. The developed integrated multiscale modelling environment can be readily extended to generate and test hypothesized novel mechanisms of developmental dynamics of other systems, including organoids that consist of several cellular and extracellular matrix layers.
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Affiliation(s)
- Ali Nematbakhsh
- Department of Mathematics, University of California, Riverside, Riverside, California, United States of America
- Interdisciplinary Center for Quantitative Modeling in Biology, University of California, Riverside, Riverside, California, United States of America
| | - Megan Levis
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana, United States of America
- Bioengineering Graduate Program, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Nilay Kumar
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Weitao Chen
- Department of Mathematics, University of California, Riverside, Riverside, California, United States of America
- Interdisciplinary Center for Quantitative Modeling in Biology, University of California, Riverside, Riverside, California, United States of America
| | - Jeremiah J. Zartman
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana, United States of America
- Bioengineering Graduate Program, University of Notre Dame, Notre Dame, Indiana, United States of America
- * E-mail: (JJZ); (MA)
| | - Mark Alber
- Department of Mathematics, University of California, Riverside, Riverside, California, United States of America
- Interdisciplinary Center for Quantitative Modeling in Biology, University of California, Riverside, Riverside, California, United States of America
- School of Medicine, University of California, Riverside, Riverside, California, United States of America
- Department of Bioengineering, University of California, Riverside, Riverside, California, United States of America
- * E-mail: (JJZ); (MA)
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Gou J, Stotsky JA, Othmer HG. Growth control in the Drosophila wing disk. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2020; 12:e1478. [PMID: 31917525 DOI: 10.1002/wsbm.1478] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 12/02/2019] [Accepted: 12/17/2019] [Indexed: 12/16/2022]
Abstract
The regulation of size and shape is a fundamental requirement of biological development and has been a subject of scientific study for centuries, but we still lack an understanding of how organisms know when to stop growing. Imaginal wing disks of the fruit fly Drosophila melanogaster, which are precursors of the adult wings, are an archetypal tissue for studying growth control. The growth of the disks is dependent on many inter- and intra-organ factors such as morphogens, mechanical forces, nutrient levels, and hormones that influence gene expression and cell growth. Extracellular signals are transduced into gene-control signals via complex signal transduction networks, and since cells typically receive many different signals, a mechanism for integrating the signals is needed. Our understanding of the effect of morphogens on tissue-level growth regulation via individual pathways has increased significantly in the last half century, but our understanding of how multiple biochemical and mechanical signals are integrated to determine whether or not a cell decides to divide is still rudimentary. Numerous fundamental questions are involved in understanding the decision-making process, and here we review the major biochemical and mechanical pathways involved in disk development with a view toward providing a basis for beginning to understand how multiple signals can be integrated at the cell level, and how this translates into growth control at the level of the imaginal disk. This article is categorized under: Analytical and Computational Methods > Computational Methods Biological Mechanisms > Cell Signaling Models of Systems Properties and Processes > Cellular Models.
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Affiliation(s)
- Jia Gou
- School of Mathematics, University of Minnesota, Minneapolis, Minnesota
| | - Jay A Stotsky
- School of Mathematics, University of Minnesota, Minneapolis, Minnesota
| | - Hans G Othmer
- School of Mathematics, University of Minnesota, Minneapolis, Minnesota
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12
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Bageritz J, Willnow P, Valentini E, Leible S, Boutros M, Teleman AA. Gene expression atlas of a developing tissue by single cell expression correlation analysis. Nat Methods 2019; 16:750-756. [PMID: 31363221 PMCID: PMC6675608 DOI: 10.1038/s41592-019-0492-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 06/13/2019] [Indexed: 01/27/2023]
Abstract
The Drosophila wing disc has been a fundamental model system for the discovery of key signaling pathways and for our understanding of developmental processes. However, a complete map of gene expression in this tissue is lacking. To obtain a complete gene expression atlas in the wing disc, we employed single-cell sequencing (scRNA-seq) and developed a new method for analyzing scRNA-seq data based on gene expression correlations rather than cell mapping. This enables us to compute expression maps for all detected genes in the wing disc and to discover 824 genes with spatially restricted expression patterns. This approach identifies both known and new clusters of genes with similar expression patterns and functional relevance. As proof of concept, we characterize the previously unstudied gene CG5151 and show that it regulates Wnt signaling. This novel method will enable the leveraging of scRNA-seq data for generating expression atlases of undifferentiated tissues during development.
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Affiliation(s)
- Josephine Bageritz
- German Cancer Research Center (DKFZ), Heidelberg, Germany.,Heidelberg University, Heidelberg, Germany
| | - Philipp Willnow
- German Cancer Research Center (DKFZ), Heidelberg, Germany.,Heidelberg University, Heidelberg, Germany.,CellNetworks-Cluster of Excellence, Heidelberg University, Heidelberg, Germany
| | - Erica Valentini
- German Cancer Research Center (DKFZ), Heidelberg, Germany.,Heidelberg University, Heidelberg, Germany
| | - Svenja Leible
- German Cancer Research Center (DKFZ), Heidelberg, Germany.,Heidelberg University, Heidelberg, Germany
| | - Michael Boutros
- German Cancer Research Center (DKFZ), Heidelberg, Germany. .,Heidelberg University, Heidelberg, Germany.
| | - Aurelio A Teleman
- German Cancer Research Center (DKFZ), Heidelberg, Germany. .,Heidelberg University, Heidelberg, Germany.
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13
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Tsingos E, Höckendorf B, Sütterlin T, Kirchmaier S, Grabe N, Centanin L, Wittbrodt J. Retinal stem cells modulate proliferative parameters to coordinate post-embryonic morphogenesis in the eye of fish. eLife 2019; 8:42646. [PMID: 30910010 PMCID: PMC6486154 DOI: 10.7554/elife.42646] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Accepted: 03/13/2019] [Indexed: 12/22/2022] Open
Abstract
Combining clonal analysis with a computational agent based model, we investigate how tissue-specific stem cells for neural retina (NR) and retinal pigmented epithelium (RPE) of the teleost medaka (Oryzias latipes) coordinate their growth rates. NR cell division timing is less variable, consistent with an upstream role as growth inducer. RPE cells divide with greater variability, consistent with a downstream role responding to inductive signals. Strikingly, the arrangement of the retinal ciliary marginal zone niche results in a spatially biased random lineage loss, where stem- and progenitor cell domains emerge spontaneously. Further, our data indicate that NR cells orient division axes to regulate organ shape and retinal topology. We highlight an unappreciated mechanism for growth coordination, where one tissue integrates cues to synchronize growth of nearby tissues. This strategy may enable evolution to modulate cell proliferation parameters in one tissue to adapt whole-organ morphogenesis in a complex vertebrate organ. By the time babies reach adulthood, they have grown many times larger than they were at birth. This development is driven by an increase in the number and size of cells in the body. In particular, special types of cells, called stem cells, act as a reservoir for tissues: they divide to create new cells that will mature into various specialized structures. The retina is the light-sensitive part of the eye. It consists of the neural retina, a tissue that contains light-detecting cells, which is supported by the retinal pigment epithelium or RPE. In fish, the RPE and neural retina are replenished by distinct groups of stem cells that do not mix, despite the tissues being close together. Unlike humans, fish grow throughout adulthood, and their eyes must then keep pace with the body. This means that the different tissues in the retina must somehow coordinate to expand at the same rate: otherwise, the retina would get wrinkled and not work properly. Tsingos et al. therefore wanted to determine how stem cells in the neural retina and RPE co-operated to produce the right number of new cells at the right time. First, stem cells in the eyes of newly hatched fish were labelled with a visible marker so that their divisions could be tracked over time to build cell family trees. This showed that stem cells behaved differently in the neural retina and the RPE. Computer simulations of the growing retina explained this behavior: stem cells in the neural retina were telling the RPE stem cells when it was time to divide. Combining results from the simulations with data from the experiments revealed that a stem cell decided to keep up dividing partly because of its position in the tissue, and partly because of random chance. To be healthy, the body needs to fine-tune the number of cells it produces: creating too few cells may make it difficult to heal after injury, but making too many could lead to diseases such as cancer. Understanding how tissues normally agree to grow together could therefore open new avenues of treatment for these conditions.
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Affiliation(s)
- Erika Tsingos
- Centre for Organismal Studies Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Burkhard Höckendorf
- Centre for Organismal Studies Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Thomas Sütterlin
- National Center for Tumor Diseases, Hamamatsu TIGA Center, Bioquant, Heidelberg University, Heidelberg, Germany
| | - Stephan Kirchmaier
- Centre for Organismal Studies Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Niels Grabe
- National Center for Tumor Diseases, Hamamatsu TIGA Center, Bioquant, Heidelberg University, Heidelberg, Germany
| | - Lazaro Centanin
- Centre for Organismal Studies Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Joachim Wittbrodt
- Centre for Organismal Studies Heidelberg, Heidelberg University, Heidelberg, Germany
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14
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Statistics of noisy growth with mechanical feedback in elastic tissues. Proc Natl Acad Sci U S A 2019; 116:5350-5355. [PMID: 30819899 DOI: 10.1073/pnas.1816100116] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Tissue growth is a fundamental aspect of development and is intrinsically noisy. Stochasticity has important implications for morphogenesis, precise control of organ size, and regulation of tissue composition and heterogeneity. However, the basic statistical properties of growing tissues, particularly when growth induces mechanical stresses that can in turn affect growth rates, have received little attention. Here, we study the noisy growth of elastic sheets subject to mechanical feedback. Considering both isotropic and anisotropic growth, we find that the density-density correlation function shows power law scaling. We also consider the dynamics of marked, neutral clones of cells. We find that the areas (but not the shapes) of two clones are always statistically independent, even when they are adjacent. For anisotropic growth, we show that clone size variance scales like the average area squared and that the mode amplitudes characterizing clone shape show a slow [Formula: see text] decay, where n is the mode index. This is in stark contrast to the isotropic case, where relative variations in clone size and shape vanish at long times. The high variability in clone statistics observed in anisotropic growth is due to the presence of two soft modes-growth modes that generate no stress. Our results lay the groundwork for more in-depth explorations of the properties of noisy tissue growth in specific biological contexts.
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15
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Levis M, Kumar N, Apakian E, Moreno C, Hernandez U, Olivares A, Ontiveros F, Zartman JJ. Microfluidics on the fly: Inexpensive rapid fabrication of thermally laminated microfluidic devices for live imaging and multimodal perturbations of multicellular systems. BIOMICROFLUIDICS 2019; 13:024111. [PMID: 31065310 PMCID: PMC6486393 DOI: 10.1063/1.5086671] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 04/08/2019] [Indexed: 05/06/2023]
Abstract
Microfluidic devices provide a platform for analyzing both natural and synthetic multicellular systems. Currently, substantial capital investment and expertise are required for creating microfluidic devices using standard soft-lithography. These requirements present barriers to entry for many nontraditional users of microfluidics, including developmental biology laboratories. Therefore, fabrication methodologies that enable rapid device iteration and work "out-of-the-box" can accelerate the integration of microfluidics with developmental biology. Here, we have created and characterized low-cost hybrid polyethylene terephthalate laminate (PETL) microfluidic devices that are suitable for cell and micro-organ culture assays. These devices were validated with mammalian cell lines and the Drosophila wing imaginal disc as a model micro-organ. First, we developed and tested PETLs that are compatible with both long-term cultures and high-resolution imaging of cells and organs. Further, we achieved spatiotemporal control of chemical gradients across the wing discs with a multilayered microfluidic device. Finally, we created a multilayered device that enables controllable mechanical loading of micro-organs. This mechanical actuation assay was used to characterize the response of larval wing discs at different developmental stages. Interestingly, increased deformation of the older wing discs for the same mechanical loading suggests that the compliance of the organ is increased in preparation for subsequent morphogenesis. Together, these results demonstrate the applicability of hybrid PETL devices for biochemical and mechanobiology studies on micro-organs and provide new insights into the mechanics of organ development.
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Affiliation(s)
- Megan Levis
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Nilay Kumar
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Emily Apakian
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Cesar Moreno
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Ulises Hernandez
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Ana Olivares
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Fernando Ontiveros
- Biology Department, St. John Fisher College, Rochester, New York 14618, USA
| | - Jeremiah J. Zartman
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA
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16
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Brodskiy PA, Wu Q, Soundarrajan DK, Huizar FJ, Chen J, Liang P, Narciso C, Levis MK, Arredondo-Walsh N, Chen DZ, Zartman JJ. Decoding Calcium Signaling Dynamics during Drosophila Wing Disc Development. Biophys J 2019; 116:725-740. [PMID: 30704858 PMCID: PMC6382932 DOI: 10.1016/j.bpj.2019.01.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 12/04/2018] [Accepted: 01/04/2019] [Indexed: 01/07/2023] Open
Abstract
The robust specification of organ development depends on coordinated cell-cell communication. This process requires signal integration among multiple pathways, relying on second messengers such as calcium ions. Calcium signaling encodes a significant portion of the cellular state by regulating transcription factors, enzymes, and cytoskeletal proteins. However, the relationships between the inputs specifying cell and organ development, calcium signaling dynamics, and final organ morphology are poorly understood. Here, we have designed a quantitative image-analysis pipeline for decoding organ-level calcium signaling. With this pipeline, we extracted spatiotemporal features of calcium signaling dynamics during the development of the Drosophila larval wing disc, a genetic model for organogenesis. We identified specific classes of wing phenotypes that resulted from calcium signaling pathway perturbations, including defects in gross morphology, vein differentiation, and overall size. We found four qualitative classes of calcium signaling activity. These classes can be ordered based on agonist stimulation strength Gαq-mediated signaling. In vivo calcium signaling dynamics depend on both receptor tyrosine kinase/phospholipase C γ and G protein-coupled receptor/phospholipase C β activities. We found that spatially patterned calcium dynamics correlate with known differential growth rates between anterior and posterior compartments. Integrated calcium signaling activity decreases with increasing tissue size, and it responds to morphogenetic perturbations that impact organ growth. Together, these findings define how calcium signaling dynamics integrate upstream inputs to mediate multiple response outputs in developing epithelial organs.
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Affiliation(s)
- Pavel A Brodskiy
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana
| | - Qinfeng Wu
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana
| | - Dharsan K Soundarrajan
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana
| | - Francisco J Huizar
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana
| | - Jianxu Chen
- Department of Computer Science and Engineering, University of Notre Dame, Notre Dame, Indiana
| | - Peixian Liang
- Department of Computer Science and Engineering, University of Notre Dame, Notre Dame, Indiana
| | - Cody Narciso
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana
| | - Megan K Levis
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana
| | | | - Danny Z Chen
- Department of Computer Science and Engineering, University of Notre Dame, Notre Dame, Indiana
| | - Jeremiah J Zartman
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana.
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17
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Juarez-Carreño S, Morante J, Dominguez M. Systemic signalling and local effectors in developmental stability, body symmetry, and size. Cell Stress 2018; 2:340-361. [PMID: 31225459 PMCID: PMC6551673 DOI: 10.15698/cst2018.12.167] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Symmetric growth and the origins of fluctuating asymmetry are unresolved phenomena of biology. Small, and sometimes noticeable, deviations from perfect bilateral symmetry reflect the vulnerability of development to perturbations. The degree of asymmetry is related to the magnitude of the perturbations and the ability of an individual to cope with them. As the left and right sides of an individual were presumed to be genetically identical, deviations of symmetry were traditionally attributed to non-genetic effects such as environmental and developmental noise. In this review, we draw attention to other possible sources of variability, especially to somatic mutations and transposons. Mutations are a major source of phenotypic variability and recent genomic data have highlighted somatic mutations as ubiquitous, even in phenotypically normal individuals. We discuss the importance of factors that are responsible for buffering and stabilizing the genome and for maintaining size robustness and quality through elimination of less-fit or damaged cells. However, the important question that arises from these studies is whether this self-correcting capacity and intrinsic organ size controls are sufficient to explain how symmetric structures can reach an identical size and shape. Indeed, recent discoveries in the fruit fly have uncovered a conserved hormone of the insulin/IGF/relaxin family, Dilp8, that is responsible for stabilizing body size and symmetry in the face of growth perturbations. Dilp8 alarm signals periphery growth status to the brain, where it acts on its receptor Lgr3. Loss of Dilp8-Lgr3 signaling renders flies incapable of detecting growth perturbations and thus maintaining a stable size and symmetry. These findings help to understand how size and symmetry of somatic tissues remain undeterred in noisy environments, after injury or illnesses, and in the presence of accumulated somatic mutations.
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Affiliation(s)
- Sergio Juarez-Carreño
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández (CSIC-UMH), Avda Santiago Ramón y Cajal s/n, Campus de Sant Joan, Alicante, Spain
| | - Javier Morante
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández (CSIC-UMH), Avda Santiago Ramón y Cajal s/n, Campus de Sant Joan, Alicante, Spain
| | - Maria Dominguez
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández (CSIC-UMH), Avda Santiago Ramón y Cajal s/n, Campus de Sant Joan, Alicante, Spain
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18
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AIP1 and cofilin ensure a resistance to tissue tension and promote directional cell rearrangement. Nat Commun 2018; 9:3295. [PMID: 30202062 PMCID: PMC6131156 DOI: 10.1038/s41467-018-05605-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 07/14/2018] [Indexed: 01/30/2023] Open
Abstract
In order to understand how tissue mechanics shapes animal body, it is critical to clarify how cells respond to and resist tissue stress when undergoing morphogenetic processes, such as cell rearrangement. Here, we address the question in the Drosophila wing epithelium, where anisotropic tissue tension orients cell rearrangements. We found that anisotropic tissue tension localizes actin interacting protein 1 (AIP1), a cofactor of cofilin, on the remodeling junction via cooperative binding of cofilin to F-actin. AIP1 and cofilin promote actin turnover and locally regulate the Canoe-mediated linkage between actomyosin and the junction. This mechanism is essential for cells to resist the mechanical load imposed on the remodeling junction perpendicular to the direction of tissue stretching. Thus, the present study delineates how AIP1 and cofilin achieve an optimal balance between resistance to tissue tension and morphogenesis.
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19
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Narciso C, Zartman J. Reverse-engineering organogenesis through feedback loops between model systems. Curr Opin Biotechnol 2017; 52:1-8. [PMID: 29275226 DOI: 10.1016/j.copbio.2017.12.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 12/11/2017] [Indexed: 02/06/2023]
Abstract
Biological complexity and ethical limitations necessitate models of human development. Traditionally, genetic model systems have provided inexpensive routes to define mechanisms governing organ development. Recent progress has led to 3D human organoid models of development and disease. However, robust methods to control the size and morphology of organoids for high throughput studies need to be developed. Additionally, insights from multiple developmental contexts are required to reveal conserved genes and processes regulating organ growth and development. Positive feedback between quantitative studies using mammalian organoids and insect micro-organs enable identification of underlying principles for organ size and shape control. Advances in the field of multicellular systems engineering are enabling unprecedented high-content studies in developmental biology and disease modeling. These will lead to fundamental advances in regenerative medicine and tissue-engineered soft robotics.
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Affiliation(s)
- Cody Narciso
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN, United States
| | - Jeremiah Zartman
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN, United States.
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20
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Ma M, Cao X, Dai J, Pastor-Pareja JC. Basement Membrane Manipulation in Drosophila Wing Discs Affects Dpp Retention but Not Growth Mechanoregulation. Dev Cell 2017; 42:97-106.e4. [PMID: 28697337 DOI: 10.1016/j.devcel.2017.06.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 05/04/2017] [Accepted: 06/02/2017] [Indexed: 01/19/2023]
Abstract
Basement membranes (BMs) are extracellular matrix polymers basally underlying epithelia, where they regulate cell signaling and tissue mechanics. Constriction by the BM shapes Drosophila wing discs, a well-characterized model of tissue growth. Recently, the hypothesis that mechanical factors govern wing growth has received much attention, but it has not been definitively tested. In this study, we manipulated BM composition to cause dramatic changes in tissue tension. We found that increased tissue compression when perlecan was knocked down did not affect adult wing size. BM elimination, decreasing compression, reduced wing size but did not visibly affect Hippo signaling, widely postulated to mediate growth mechanoregulation. BM elimination, in contrast, attenuated signaling by bone morphogenetic protein/transforming growth factor β ligand Dpp, which was not efficiently retained within the tissue and escaped to the body cavity. Our results challenge mechanoregulation of wing growth, while uncovering a function of BMs in preserving a growth-promoting tissue environment.
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Affiliation(s)
- Mengqi Ma
- School of Life Sciences, Tsinghua University, Medical Science Building, D224, Beijing 100084, China
| | - Xueya Cao
- School of Life Sciences, Tsinghua University, Medical Science Building, D224, Beijing 100084, China
| | - Jianli Dai
- School of Life Sciences, Tsinghua University, Medical Science Building, D224, Beijing 100084, China
| | - José C Pastor-Pareja
- School of Life Sciences, Tsinghua University, Medical Science Building, D224, Beijing 100084, China.
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21
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Narciso CE, Contento NM, Storey TJ, Hoelzle DJ, Zartman JJ. Release of Applied Mechanical Loading Stimulates Intercellular Calcium Waves in Drosophila Wing Discs. Biophys J 2017; 113:491-501. [PMID: 28746859 PMCID: PMC5529297 DOI: 10.1016/j.bpj.2017.05.051] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 05/15/2017] [Accepted: 05/17/2017] [Indexed: 01/14/2023] Open
Abstract
Mechanical forces are critical but poorly understood inputs for organogenesis and wound healing. Calcium ions (Ca2+) are critical second messengers in cells for integrating environmental and mechanical cues, but the regulation of Ca2+ signaling is poorly understood in developing epithelial tissues. Here we report a chip-based regulated environment for microorgans that enables systematic investigations of the crosstalk between an organ's mechanical stress environment and biochemical signaling under genetic and chemical perturbations. This method enabled us to define the essential conditions for generating organ-scale intercellular Ca2+ waves in Drosophila wing discs that are also observed in vivo during organ development. We discovered that mechanically induced intercellular Ca2+ waves require fly extract growth serum as a chemical stimulus. Using the chip-based regulated environment for microorgans, we demonstrate that not the initial application but instead the release of mechanical loading is sufficient, but not necessary, to initiate intercellular Ca2+ waves. The Ca2+ response depends on the prestress intercellular Ca2+ activity and not on the magnitude or duration of the mechanical stimulation applied. Mechanically induced intercellular Ca2+ waves rely on IP3R-mediated Ca2+-induced Ca2+ release and propagation through gap junctions. Thus, intercellular Ca2+ waves in developing epithelia may be a consequence of stress dissipation during organ growth.
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Affiliation(s)
- Cody E Narciso
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana
| | - Nicholas M Contento
- Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana
| | - Thomas J Storey
- Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana
| | - David J Hoelzle
- Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana.
| | - Jeremiah J Zartman
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana.
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22
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Strassburger K, Lorbeer FK, Lutz M, Graf F, Boutros M, Teleman AA. Oxygenation and adenosine deaminase support growth and proliferation of ex vivo cultured Drosophila wing imaginal discs. Development 2017; 144:2529-2538. [PMID: 28526754 DOI: 10.1242/dev.147538] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 05/11/2017] [Indexed: 01/22/2023]
Abstract
The Drosophila wing imaginal disc has been an important model system over past decades for discovering novel biology related to development, signaling and epithelial morphogenesis. Novel experimental approaches have been enabled using a culture setup that allows ex vivo cultures of wing discs. Current setups, however, are not able to sustain both growth and cell-cycle progression of wing discs ex vivo We discover here a setup that requires both oxygenation of the tissue and adenosine deaminase activity in the medium, and supports both growth and proliferation of wing discs for 9 h. Nonetheless, further work will be required to extend the duration of the culturing and to enable live imaging of the cultured discs in the future.
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Affiliation(s)
| | | | - Marilena Lutz
- German Cancer Research Center (DKFZ), Heidelberg 69120, Germany
| | - Fabian Graf
- German Cancer Research Center (DKFZ), Heidelberg 69120, Germany
| | - Michael Boutros
- German Cancer Research Center (DKFZ), Heidelberg 69120, Germany
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23
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Nematbakhsh A, Sun W, Brodskiy PA, Amiri A, Narciso C, Xu Z, Zartman JJ, Alber M. Multi-scale computational study of the mechanical regulation of cell mitotic rounding in epithelia. PLoS Comput Biol 2017; 13:e1005533. [PMID: 28531187 PMCID: PMC5460904 DOI: 10.1371/journal.pcbi.1005533] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 06/06/2017] [Accepted: 04/24/2017] [Indexed: 12/20/2022] Open
Abstract
Mitotic rounding during cell division is critical for preventing daughter cells from inheriting an abnormal number of chromosomes, a condition that occurs frequently in cancer cells. Cells must significantly expand their apical area and transition from a polygonal to circular apical shape to achieve robust mitotic rounding in epithelial tissues, which is where most cancers initiate. However, how cells mechanically regulate robust mitotic rounding within packed tissues is unknown. Here, we analyze mitotic rounding using a newly developed multi-scale subcellular element computational model that is calibrated using experimental data. Novel biologically relevant features of the model include separate representations of the sub-cellular components including the apical membrane and cytoplasm of the cell at the tissue scale level as well as detailed description of cell properties during mitotic rounding. Regression analysis of predictive model simulation results reveals the relative contributions of osmotic pressure, cell-cell adhesion and cortical stiffness to mitotic rounding. Mitotic area expansion is largely driven by regulation of cytoplasmic pressure. Surprisingly, mitotic shape roundness within physiological ranges is most sensitive to variation in cell-cell adhesivity and stiffness. An understanding of how perturbed mechanical properties impact mitotic rounding has important potential implications on, amongst others, how tumors progressively become more genetically unstable due to increased chromosomal aneuploidy and more aggressive.
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Affiliation(s)
- Ali Nematbakhsh
- Department of Applied and Computational Mathematics and Statistics, University of Notre Dame, Notre Dame, Indiana, United States of America
- Department of Mathematics, University of California, Riverside, California, United States of America
| | - Wenzhao Sun
- Department of Applied and Computational Mathematics and Statistics, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Pavel A. Brodskiy
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Aboutaleb Amiri
- Department of Physics, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Cody Narciso
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Zhiliang Xu
- Department of Applied and Computational Mathematics and Statistics, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Jeremiah J. Zartman
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Mark Alber
- Department of Applied and Computational Mathematics and Statistics, University of Notre Dame, Notre Dame, Indiana, United States of America
- Department of Mathematics, University of California, Riverside, California, United States of America
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24
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Šikić H, Shi Y, Lubura S, Bassnett S. A full lifespan model of vertebrate lens growth. ROYAL SOCIETY OPEN SCIENCE 2017; 4:160695. [PMID: 28280571 PMCID: PMC5319337 DOI: 10.1098/rsos.160695] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 12/05/2016] [Indexed: 06/06/2023]
Abstract
The mathematical determinants of vertebrate organ growth have yet to be elucidated fully. Here, we utilized empirical measurements and a dynamic branching process-based model to examine the growth of a simple organ system, the mouse lens, from E14.5 until the end of life. Our stochastic model used difference equations to model immigration and emigration between zones of the lens epithelium and included some deterministic elements, such as cellular footprint area. We found that the epithelial cell cycle was shortened significantly in the embryo, facilitating the rapid growth that marks early lens development. As development progressed, epithelial cell division becomes non-uniform and four zones, each with a characteristic proliferation rate, could be discerned. Adjustment of two model parameters, proliferation rate and rate of change in cellular footprint area, was sufficient to specify all growth trajectories. Modelling suggested that the direction of cellular migration across zonal boundaries was sensitive to footprint area, a phenomenon that may isolate specific cell populations. Model runs consisted of more than 1000 iterations, in each of which the stochastic behaviour of thousands of cells was followed. Nevertheless, sequential runs were almost superimposable. This remarkable degree of precision was attributed, in part, to the presence of non-mitotic flanking regions, which constituted a path by which epithelial cells could escape the growth process. Spatial modelling suggested that clonal clusters of about 50 cells are produced during migration and that transit times lengthen significantly at later stages, findings with implications for the formation of certain types of cataract.
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Affiliation(s)
- Hrvoje Šikić
- Department of Ophthalmology and Visual Sciences, Washington University, St Louis, MO 63130, USA
- Department of Mathematics, University of Zagreb, Zagreb, Croatia
| | - Yanrong Shi
- Department of Ophthalmology and Visual Sciences, Washington University, St Louis, MO 63130, USA
| | - Snježana Lubura
- Department of Mathematics, University of Zagreb, Zagreb, Croatia
| | - Steven Bassnett
- Department of Ophthalmology and Visual Sciences, Washington University, St Louis, MO 63130, USA
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25
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Huang J, Wang L, Xiong C, Yuan F. Elastic hydrogel as a sensor for detection of mechanical stress generated by single cells grown in three-dimensional environment. Biomaterials 2016; 98:103-12. [DOI: 10.1016/j.biomaterials.2016.04.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 04/20/2016] [Accepted: 04/22/2016] [Indexed: 12/12/2022]
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26
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Kis Z, Rodin T, Zafar A, Lai Z, Freke G, Fleck O, Del Rio Hernandez A, Towhidi L, Pedrigi RM, Homma T, Krams R. Development of a synthetic gene network to modulate gene expression by mechanical forces. Sci Rep 2016; 6:29643. [PMID: 27404994 PMCID: PMC4940741 DOI: 10.1038/srep29643] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 06/24/2016] [Indexed: 12/14/2022] Open
Abstract
The majority of (mammalian) cells in our body are sensitive to mechanical forces, but little work has been done to develop assays to monitor mechanosensor activity. Furthermore, it is currently impossible to use mechanosensor activity to drive gene expression. To address these needs, we developed the first mammalian mechanosensitive synthetic gene network to monitor endothelial cell shear stress levels and directly modulate expression of an atheroprotective transcription factor by shear stress. The technique is highly modular, easily scalable and allows graded control of gene expression by mechanical stimuli in hard-to-transfect mammalian cells. We call this new approach mechanosyngenetics. To insert the gene network into a high proportion of cells, a hybrid transfection procedure was developed that involves electroporation, plasmids replication in mammalian cells, mammalian antibiotic selection, a second electroporation and gene network activation. This procedure takes 1 week and yielded over 60% of cells with a functional gene network. To test gene network functionality, we developed a flow setup that exposes cells to linearly increasing shear stress along the length of the flow channel floor. Activation of the gene network varied logarithmically as a function of shear stress magnitude.
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Affiliation(s)
- Zoltán Kis
- Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, United Kingdom
| | - Tania Rodin
- Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, United Kingdom
| | - Asma Zafar
- Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, United Kingdom
- Government College University, GC University, Katchery Road, Lahore, 54000, Pakistan
| | - Zhangxing Lai
- Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, United Kingdom
- Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, 117575, Singapore
- Department of Biomedical Engineering, National University of Singapore, 4 Engineering Drive 3, 117583, Singapore
| | - Grace Freke
- Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, United Kingdom
- Institute of Child Health, University College London, 30 Guilford Street, London, WC1N 1EH, United Kingdom
| | - Oliver Fleck
- Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, United Kingdom
- Department of Engineering, University of Cambridge, Trumpington Street, Cambridge, CB2 1PZ, United Kingdom
| | - Armando Del Rio Hernandez
- Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, United Kingdom
| | - Leila Towhidi
- Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, United Kingdom
| | - Ryan M. Pedrigi
- Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, United Kingdom
| | - Takayuki Homma
- Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, United Kingdom
- Institute for Integrated Cell-Material Sciences, Kyoto University, Yoshida Ushinomiya-cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Rob Krams
- Department of Bioengineering, Imperial College London, Exhibition Road, London, SW7 2AZ, United Kingdom
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Dowling A, Doroba C, Maier JA, Cohen L, VandeBerg J, Sears KE. Cellular and molecular drivers of differential organ growth: insights from the limbs of Monodelphis domestica. Dev Genes Evol 2016; 226:235-43. [PMID: 27194412 DOI: 10.1007/s00427-016-0549-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 05/03/2016] [Indexed: 10/21/2022]
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Konstorum A, Hillen T, Lowengrub J. Feedback Regulation in a Cancer Stem Cell Model can Cause an Allee Effect. Bull Math Biol 2016; 78:754-785. [PMID: 27113934 DOI: 10.1007/s11538-016-0161-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 03/15/2016] [Indexed: 12/24/2022]
Abstract
The exact mechanisms of spontaneous tumor remission or complete response to treatment are phenomena in oncology that are not completely understood. We use a concept from ecology, the Allee effect, to help explain tumor extinction in a model of tumor growth that incorporates feedback regulation of stem cell dynamics, which occurs in many tumor types where certain signaling molecules, such as Wnts, are upregulated. Due to feedback and the Allee effect, a tumor may become extinct spontaneously or after therapy even when the entire tumor has not been eradicated by the end of therapy. We quantify the Allee effect using an 'Allee index' that approximates the area of the basin of attraction for tumor extinction. We show that effectiveness of combination therapy in cancer treatment may occur due to the increased probability that the system will be in the Allee region after combination treatment versus monotherapy. We identify therapies that can attenuate stem cell self-renewal, alter the Allee region and increase its size. We also show that decreased response of tumor cells to growth inhibitors can reduce the size of the Allee region and increase stem cell densities, which may help to explain why this phenomenon is a hallmark of cancer.
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Affiliation(s)
- Anna Konstorum
- Department of Mathematics, University of California, Irvine, Irvine, CA, USA.
- Center for Complex Biological Systems, University of California, Irvine, Irvine, CA, USA.
- Center for Quantitative Medicine, University of Connecticut Health Center, Farmington, CT, USA.
| | - Thomas Hillen
- Centre for Mathematical Biology, University of Alberta, Edmonton, AB, Canada
| | - John Lowengrub
- Department of Mathematics, University of California, Irvine, Irvine, CA, USA.
- Center for Complex Biological Systems, University of California, Irvine, Irvine, CA, USA.
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, USA.
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Henry RA, Singh T, Kuo YM, Biester A, O'Keefe A, Lee S, Andrews AJ, O'Reilly AM. Quantitative Measurement of Histone Tail Acetylation Reveals Stage-Specific Regulation and Response to Environmental Changes during Drosophila Development. Biochemistry 2016; 55:1663-72. [PMID: 26836402 DOI: 10.1021/acs.biochem.5b01070] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Histone modification plays a major role in regulating gene transcription and ensuring the healthy development of an organism. Numerous studies have suggested that histones are dynamically modified during developmental events to control gene expression levels in a temporal and spatial manner. However, the study of histone acetylation dynamics using currently available techniques is hindered by the difficulty of simultaneously measuring acetylation of the numerous potential sites of modification present in histones. Here, we present a methodology that allows us to combine mass spectrometry-based histone analysis with Drosophila developmental genetics. Using this system, we characterized histone acetylation patterns during multiple developmental stages of the fly. Additionally, we utilized this analysis to characterize how treatments with pharmacological agents or environmental changes such as γ-irradiation altered histone acetylation patterns. Strikingly, γ-irradiation dramatically increased the level of acetylation at H3K18, a site linked to DNA repair via nonhomologous end joining. In mutant fly strains deficient in DNA repair proteins, however, this increase in the level of H3K18 acetylation was lost. These results demonstrate the efficacy of our combined mass spectrometry system with a Drosophila model system and provide interesting insight into the changes in histone acetylation during development, as well as the effects of both pharmacological and environmental agents on global histone acetylation.
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Affiliation(s)
- Ryan A Henry
- Department of Cancer Biology, Fox Chase Cancer Center , Philadelphia, Pennsylvania 19111, United States
| | - Tanu Singh
- Department of Cancer Biology, Fox Chase Cancer Center , Philadelphia, Pennsylvania 19111, United States.,Department of Biochemistry and Molecular Biology, Drexel College of Medicine , Philadelphia, Pennsylvania 19102, United States
| | - Yin-Ming Kuo
- Department of Cancer Biology, Fox Chase Cancer Center , Philadelphia, Pennsylvania 19111, United States
| | - Alison Biester
- Immersion Science Program, Fox Chase Cancer Center , Philadelphia, Pennsylvania 19111, United States
| | - Abigail O'Keefe
- Immersion Science Program, Fox Chase Cancer Center , Philadelphia, Pennsylvania 19111, United States
| | - Sandy Lee
- Immersion Science Program, Fox Chase Cancer Center , Philadelphia, Pennsylvania 19111, United States
| | - Andrew J Andrews
- Department of Cancer Biology, Fox Chase Cancer Center , Philadelphia, Pennsylvania 19111, United States
| | - Alana M O'Reilly
- Department of Cancer Biology, Fox Chase Cancer Center , Philadelphia, Pennsylvania 19111, United States
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Kursawe J, Brodskiy PA, Zartman JJ, Baker RE, Fletcher AG. Capabilities and Limitations of Tissue Size Control through Passive Mechanical Forces. PLoS Comput Biol 2015; 11:e1004679. [PMID: 26713738 PMCID: PMC4703071 DOI: 10.1371/journal.pcbi.1004679] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 11/24/2015] [Indexed: 12/29/2022] Open
Abstract
Embryogenesis is an extraordinarily robust process, exhibiting the ability to control tissue size and repair patterning defects in the face of environmental and genetic perturbations. The size and shape of a developing tissue is a function of the number and size of its constituent cells as well as their geometric packing. How these cellular properties are coordinated at the tissue level to ensure developmental robustness remains a mystery; understanding this process requires studying multiple concurrent processes that make up morphogenesis, including the spatial patterning of cell fates and apoptosis, as well as cell intercalations. In this work, we develop a computational model that aims to understand aspects of the robust pattern repair mechanisms of the Drosophila embryonic epidermal tissues. Size control in this system has previously been shown to rely on the regulation of apoptosis rather than proliferation; however, to date little work has been done to understand the role of cellular mechanics in this process. We employ a vertex model of an embryonic segment to test hypotheses about the emergence of this size control. Comparing the model to previously published data across wild type and genetic perturbations, we show that passive mechanical forces suffice to explain the observed size control in the posterior (P) compartment of a segment. However, observed asymmetries in cell death frequencies across the segment are demonstrated to require patterning of cellular properties in the model. Finally, we show that distinct forms of mechanical regulation in the model may be distinguished by differences in cell shapes in the P compartment, as quantified through experimentally accessible summary statistics, as well as by the tissue recoil after laser ablation experiments.
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Affiliation(s)
- Jochen Kursawe
- Mathematical Institute, University of Oxford, Oxford, United Kingdom
| | - Pavel A. Brodskiy
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Jeremiah J. Zartman
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana, United States of America
- * E-mail: (JJZ); (AGF)
| | - Ruth E. Baker
- Mathematical Institute, University of Oxford, Oxford, United Kingdom
| | - Alexander G. Fletcher
- Mathematical Institute, University of Oxford, Oxford, United Kingdom
- School of Mathematics and Statistics, University of Sheffield, Sheffield, United Kingdom
- * E-mail: (JJZ); (AGF)
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Narciso C, Wu Q, Brodskiy P, Garston G, Baker R, Fletcher A, Zartman J. Patterning of wound-induced intercellular Ca(2+) flashes in a developing epithelium. Phys Biol 2015; 12:056005. [PMID: 26331891 DOI: 10.1088/1478-3975/12/5/056005] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Differential mechanical force distributions are increasingly recognized to provide important feedback into the control of an organ's final size and shape. As a second messenger that integrates and relays mechanical information to the cell, calcium ions (Ca(2+)) are a prime candidate for providing important information on both the overall mechanical state of the tissue and resulting behavior at the individual-cell level during development. Still, how the spatiotemporal properties of Ca(2+) transients reflect the underlying mechanical characteristics of tissues is still poorly understood. Here we use an established model system of an epithelial tissue, the Drosophila wing imaginal disc, to investigate how tissue properties impact the propagation of Ca(2+) transients induced by laser ablation. The resulting intercellular Ca(2+) flash is found to be mediated by inositol 1,4,5-trisphosphate and depends on gap junction communication. Further, we find that intercellular Ca(2+) transients show spatially non-uniform characteristics across the proximal-distal axis of the larval wing imaginal disc, which exhibit a gradient in cell size and anisotropy. A computational model of Ca(2+) transients is employed to identify the principle factors explaining the spatiotemporal patterning dynamics of intercellular Ca(2+) flashes. The relative Ca(2+) flash anisotropy is principally explained by local cell shape anisotropy. Further, Ca(2+) velocities are relatively uniform throughout the wing disc, irrespective of cell size or anisotropy. This can be explained by the opposing effects of cell diameter and cell elongation on intercellular Ca(2+) propagation. Thus, intercellular Ca(2+) transients follow lines of mechanical tension at velocities that are largely independent of tissue heterogeneity and reflect the mechanical state of the underlying tissue.
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Affiliation(s)
- Cody Narciso
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, 182 Fitzpatrick Hall, Notre Dame, IN 46556, USA
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Fukushima K, Fujita H, Yamaguchi T, Kawaguchi M, Tsukaya H, Hasebe M. Oriented cell division shapes carnivorous pitcher leaves of Sarracenia purpurea. Nat Commun 2015; 6:6450. [PMID: 25774486 PMCID: PMC4382701 DOI: 10.1038/ncomms7450] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 01/30/2015] [Indexed: 11/22/2022] Open
Abstract
Complex morphology is an evolutionary outcome of phenotypic diversification. In some carnivorous plants, the ancestral planar leaf has been modified to form a pitcher shape. However, how leaf development was altered during evolution remains unknown. Here we show that the pitcher leaves of Sarracenia purpurea develop through cell division patterns of adaxial tissues that are distinct from those in bifacial and peltate leaves, subsequent to standard expression of adaxial and abaxial marker genes. Differences in the orientation of cell divisions in the adaxial domain cause bifacial growth in the distal region and adaxial ridge protrusion in the middle region. These different growth patterns establish pitcher morphology. A computer simulation suggests that the cell division plane is critical for the pitcher morphogenesis. Our results imply that tissue-specific changes in the orientation of cell division underlie the development of a morphologically complex leaf. The pitcher-shaped leaf of the carnivorous plant Sarracenia purpurea acts as a pitfall trap to capture small animals. Here, Fukushima et al. analyse pitcher leaf development and propose that this unusual shape evolved from ancestral planar leaves through changes in the orientation of cell division.
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Affiliation(s)
- Kenji Fukushima
- 1] 1Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki 444-8585, Japan [2] National Institute for Basic Biology, Myodaiji-cho, Nishigonaka 38, Okazaki, Aichi 444-8585, Japan
| | - Hironori Fujita
- National Institute for Basic Biology, Myodaiji-cho, Nishigonaka 38, Okazaki, Aichi 444-8585, Japan
| | - Takahiro Yamaguchi
- Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masayoshi Kawaguchi
- 1] 1Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki 444-8585, Japan [2] National Institute for Basic Biology, Myodaiji-cho, Nishigonaka 38, Okazaki, Aichi 444-8585, Japan
| | - Hirokazu Tsukaya
- Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Mitsuyasu Hasebe
- 1] 1Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki 444-8585, Japan [2] National Institute for Basic Biology, Myodaiji-cho, Nishigonaka 38, Okazaki, Aichi 444-8585, Japan
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Size control during organogenesis: Development of the lateral line organs in zebrafish. Dev Growth Differ 2015; 57:169-78. [DOI: 10.1111/dgd.12196] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 12/18/2014] [Accepted: 12/18/2014] [Indexed: 12/30/2022]
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