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Matas-Gil A, Endres RG. Unraveling biochemical spatial patterns: Machine learning approaches to the inverse problem of stationary Turing patterns. iScience 2024; 27:109822. [PMID: 38827409 PMCID: PMC11140185 DOI: 10.1016/j.isci.2024.109822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 03/14/2024] [Accepted: 04/24/2024] [Indexed: 06/04/2024] Open
Abstract
The diffusion-driven Turing instability is a potential mechanism for spatial pattern formation in numerous biological and chemical systems. However, engineering these patterns and demonstrating that they are produced by this mechanism is challenging. To address this, we aim to solve the inverse problem in artificial and experimental Turing patterns. This task is challenging since patterns are often corrupted by noise and slight changes in initial conditions can lead to different patterns. We used both least squares to explore the problem and physics-informed neural networks to build a noise-robust method. We elucidate the functionality of our network in scenarios mimicking biological noise levels and showcase its application using an experimentally obtained chemical pattern. The findings reveal the significant promise of machine learning in steering the creation of synthetic patterns in bioengineering, thereby advancing our grasp of morphological intricacies within biological systems while acknowledging existing limitations.
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Affiliation(s)
- Antonio Matas-Gil
- Department of Life Sciences & Centre for Integrative Systems Biology and Bioinformatics, Imperial College London, London SW7 2BU, UK
| | - Robert G. Endres
- Department of Life Sciences & Centre for Integrative Systems Biology and Bioinformatics, Imperial College London, London SW7 2BU, UK
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2
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Dawson J, Bryant A, Jordan T, Bhikot S, Macon S, Walton B, Ajamu-Johnson A, Langridge PD, Malmi-Kakkada AN. Contact area and tissue growth dynamics shape synthetic juxtacrine signaling patterns. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.07.12.548752. [PMID: 37503188 PMCID: PMC10370035 DOI: 10.1101/2023.07.12.548752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Cell-cell communication through direct contact, or juxtacrine signaling, is important in development, disease, and many areas of physiology. Synthetic forms of juxtacrine signaling can be precisely controlled and operate orthogonally to native processes, making them a powerful reductionist tool with which to address fundamental questions in cell-cell communication in vivo. Here we investigate how cell-cell contact length and tissue growth dynamics affect juxtacrine signal responses through implementing a custom synthetic gene circuit in Drosophila wing imaginal discs alongside mathematical modeling to determine synthetic Notch (synNotch) activation patterns. We find that the area of contact between cells largely determines the extent of synNotch activation, leading to the prediction that the shape of the interface between signal-sending and signal-receiving cells will impact the magnitude of the synNotch response. Notably, synNotch outputs form a graded spatial profile that extends several cell diameters from the signal source, providing evidence that the response to juxtacrine signals can persist in cells as they proliferate away from source cells, or that cells remain able to communicate directly over several cell diameters. Our model suggests the former mechanism may be sufficient, since it predicts graded outputs without diffusion or long-range cell-cell communication. Overall, we identify that cell-cell contact area together with output synthesis and decay rates likely govern the pattern of synNotch outputs in both space and time during tissue growth, insights that may have broader implications for juxtacrine signaling in general.
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3
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Gumuskaya G, Srivastava P, Cooper BG, Lesser H, Semegran B, Garnier S, Levin M. Motile Living Biobots Self-Construct from Adult Human Somatic Progenitor Seed Cells. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2303575. [PMID: 38032125 PMCID: PMC10811512 DOI: 10.1002/advs.202303575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 10/31/2023] [Indexed: 12/01/2023]
Abstract
Fundamental knowledge gaps exist about the plasticity of cells from adult soma and the potential diversity of body shape and behavior in living constructs derived from genetically wild-type cells. Here anthrobots are introduced, a spheroid-shaped multicellular biological robot (biobot) platform with diameters ranging from 30 to 500 microns and cilia-powered locomotive abilities. Each Anthrobot begins as a single cell, derived from the adult human lung, and self-constructs into a multicellular motile biobot after being cultured in extra cellular matrix for 2 weeks and transferred into a minimally viscous habitat. Anthrobots exhibit diverse behaviors with motility patterns ranging from tight loops to straight lines and speeds ranging from 5-50 microns s-1 . The anatomical investigations reveal that this behavioral diversity is significantly correlated with their morphological diversity. Anthrobots can assume morphologies with fully polarized or wholly ciliated bodies and spherical or ellipsoidal shapes, each related to a distinct movement type. Anthrobots are found to be capable of traversing, and inducing rapid repair of scratches in, cultured human neural cell sheets in vitro. By controlling microenvironmental cues in bulk, novel structures, with new and unexpected behavior and biomedically-relevant capabilities, can be discovered in morphogenetic processes without direct genetic editing or manual sculpting.
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Affiliation(s)
- Gizem Gumuskaya
- Allen Discovery Center at Tufts Universityand Department of BiologyTufts UniversityMedfordMA02155USA
- Wyss Institute for Biologically Inspired EngineeringHarvard UniversityBostonMA02115USA
| | - Pranjal Srivastava
- Allen Discovery Center at Tufts Universityand Department of BiologyTufts UniversityMedfordMA02155USA
| | - Ben G. Cooper
- Allen Discovery Center at Tufts Universityand Department of BiologyTufts UniversityMedfordMA02155USA
| | - Hannah Lesser
- Allen Discovery Center at Tufts Universityand Department of BiologyTufts UniversityMedfordMA02155USA
| | - Ben Semegran
- Allen Discovery Center at Tufts Universityand Department of BiologyTufts UniversityMedfordMA02155USA
| | - Simon Garnier
- Federated Department of Biological SciencesNew Jersey Institute of TechnologyNewarkNJ07102USA
| | - Michael Levin
- Allen Discovery Center at Tufts Universityand Department of BiologyTufts UniversityMedfordMA02155USA
- Wyss Institute for Biologically Inspired EngineeringHarvard UniversityBostonMA02115USA
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4
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Biswas S, Clawson W, Levin M. Learning in Transcriptional Network Models: Computational Discovery of Pathway-Level Memory and Effective Interventions. Int J Mol Sci 2022; 24:ijms24010285. [PMID: 36613729 PMCID: PMC9820177 DOI: 10.3390/ijms24010285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 11/23/2022] [Accepted: 12/20/2022] [Indexed: 12/28/2022] Open
Abstract
Trainability, in any substrate, refers to the ability to change future behavior based on past experiences. An understanding of such capacity within biological cells and tissues would enable a particularly powerful set of methods for prediction and control of their behavior through specific patterns of stimuli. This top-down mode of control (as an alternative to bottom-up modification of hardware) has been extensively exploited by computer science and the behavioral sciences; in biology however, it is usually reserved for organism-level behavior in animals with brains, such as training animals towards a desired response. Exciting work in the field of basal cognition has begun to reveal degrees and forms of unconventional memory in non-neural tissues and even in subcellular biochemical dynamics. Here, we characterize biological gene regulatory circuit models and protein pathways and find them capable of several different kinds of memory. We extend prior results on learning in binary transcriptional networks to continuous models and identify specific interventions (regimes of stimulation, as opposed to network rewiring) that abolish undesirable network behavior such as drug pharmacoresistance and drug sensitization. We also explore the stability of created memories by assessing their long-term behavior and find that most memories do not decay over long time periods. Additionally, we find that the memory properties are quite robust to noise; surprisingly, in many cases noise actually increases memory potential. We examine various network properties associated with these behaviors and find that no one network property is indicative of memory. Random networks do not show similar memory behavior as models of biological processes, indicating that generic network dynamics are not solely responsible for trainability. Rational control of dynamic pathway function using stimuli derived from computational models opens the door to empirical studies of proto-cognitive capacities in unconventional embodiments and suggests numerous possible applications in biomedicine, where behavior shaping of pathway responses stand as a potential alternative to gene therapy.
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Affiliation(s)
- Surama Biswas
- Allen Discovery Center, Tufts University, Medford, MA 02155, USA
- Department of Computer Science & Engineering and Information Technology, Meghnad Saha Institute of Technology, Kolkata 700150, India
| | - Wesley Clawson
- Allen Discovery Center, Tufts University, Medford, MA 02155, USA
| | - Michael Levin
- Allen Discovery Center, Tufts University, Medford, MA 02155, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA
- Correspondence: ; Tel.: +1-617-627-6161
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5
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Banerjee D, Singh YP, Datta P, Ozbolat V, O'Donnell A, Yeo M, Ozbolat IT. Strategies for 3D bioprinting of spheroids: A comprehensive review. Biomaterials 2022; 291:121881. [DOI: 10.1016/j.biomaterials.2022.121881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 10/04/2022] [Accepted: 10/23/2022] [Indexed: 11/17/2022]
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6
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Abpeikar Z, Alizadeh AA, Ahmadyousefi Y, Najafi AA, Safaei M. Engineered cells along with smart scaffolds: critical factors for improving tissue engineering approaches. Regen Med 2022; 17:855-876. [PMID: 36065834 DOI: 10.2217/rme-2022-0059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In this review, gene delivery and its applications are discussed in tissue engineering (TE); also, new techniques such as the CRISPR-Cas9 system, synthetics biology and molecular dynamics simulation to improve the efficiency of the scaffolds have been studied. CRISPR-Cas9 is expected to make significant advances in TE in the future. The fundamentals of synthetic biology have developed powerful and flexible methods for programming cells via artificial genetic circuits. The combination of regenerative medicine and artificial biology allows the engineering of cells and organisms for use in TE, biomaterials, bioprocessing and scaffold development. The dynamics of protein adsorption at the scaffold surface at the atomic level can provide valuable guidelines for the future design of TE scaffolds /implants.
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Affiliation(s)
- Zahra Abpeikar
- Department of Tissue Engineering & Applied Cell Sciences, School of Advance Medical Science & Technology, Shiraz University of Medical Sciences, Shiraz, 7133654361, Iran
| | - Ali Akbar Alizadeh
- Department of Tissue Engineering & Applied Cell Sciences, School of Advance Medical Science & Technology, Shiraz University of Medical Sciences, Shiraz, 7133654361, Iran
| | - Yaghoub Ahmadyousefi
- Research Center for Molecular Medicine, School of Medicine, Hamadan University of Medical Sciences, Hamadan, 6517838687, Iran
| | - Ali Akbar Najafi
- Student Research Committee, Faculty of Medicine, Hormozgan University of Medical Sciences, Bandar Abbas, 7919693116, Iran
| | - Mohsen Safaei
- Department of Medical Biotechnology, School of Advanced Technologies, Shahrekord University of Medical Sciences, Shahrekord, 8815713471, Iran
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Smiley P, Levin M. Competition for finite resources as coordination mechanism for morphogenesis: An evolutionary algorithm study of digital embryogeny. Biosystems 2022; 221:104762. [PMID: 36064151 DOI: 10.1016/j.biosystems.2022.104762] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 08/17/2022] [Indexed: 01/02/2023]
Abstract
The standard view of embryogenesis is one of cooperation driven by the cells' shared genetics and evolutionary interests. However, numerous examples from developmental biology and agriculture reveal a surprising amount of competition among body cells, tissues, and organs for both metabolic and informational resources. To explain the existence of such competition we had hypothesized that evolution uses limiting "reservoirs" of resource molecules as a communication medium - a global scratchpad, to enable tissues across the body to coordinate growth. Here, we test this hypothesis via an evolutionary simulation of embryogeny in silico. Genomes encode state transition rules for cells, such as proliferation, differentiation, and resource use, enabling virtual embryos to develop a specific large-scale morphology. An evolutionary algorithm operates over the genomes, with fitness defined as a function of specific morphological requirements for the final embryo shape. We found that not only does such an algorithm rapidly discover rules for cellular behavior that reliably make embryos with specific anatomical properties, but that it discovers the strategy of using finite resources to coordinate development. Given the option of using finite or infinite reservoirs (which determine cells' ability to carry out specific actions), evolution preferentially uses finite reservoirs, which results in higher fitness and increased consistency (without needing direct selection for morphological invariance). We report aspects of anatomical, physiological/transcriptional, and genomic analysis of evolved virtual embryos that help understand how evolution can use competition among genetically identical subunits within a multicellular body to coordinate reliable, complex morphogenesis. Our results suggest that under some conditions, composite multi-scale systems will promote conflict and artificial scarcity for their components.
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Affiliation(s)
- Peter Smiley
- Department of Computer Science, Tufts University, Medford, MA, USA
| | - Michael Levin
- Allen Discovery Center at Tufts University and Department of Biology, Medford, MA, USA; Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, MA, USA.
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Davies JA. Synthetic Morphogenesis: introducing IEEE journal readers to programming living mammalian cells to make structures. PROCEEDINGS OF THE IEEE. INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS 2022; 110:688-707. [PMID: 36590991 PMCID: PMC7614003 DOI: 10.1109/jproc.2021.3137077] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Synthetic morphogenesis is a new engineering discipline, in which cells are genetically engineered to make designed shapes and structures. At least in this early phase of the field, devices tend to make use of natural shape-generating processes that operate in embryonic development, but invoke them artificially at times and in orders of a technologist's choosing. This requires construction of genetic control, sequencing and feedback systems that have close parallels to electronic design, which is one reason the field may be of interest to readers of IEEE journals. The other reason is that synthetic morphogenesis allows the construction of two-way interfaces, especially opto-genetic and opto-electronic, between the living and the electronic, allowing unprecedented information flow and control between the two types of 'machine'. This review introduces synthetic morphogenesis, illustrates what has been achieved, drawing parallels wherever possible between biology and electronics, and looks forward to likely next steps and challenges to be overcome.
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Affiliation(s)
- Jamie A Davies
- Professor of Experimental Anatomy at the University of Edinburgh, UK, and a member of the Centre for Mammalian Synthetic Biology at that University
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9
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Javdan SB, Deans TL. Design and development of engineered receptors for cell and tissue engineering. CURRENT OPINION IN SYSTEMS BIOLOGY 2021; 28:100363. [PMID: 34527831 PMCID: PMC8437148 DOI: 10.1016/j.coisb.2021.100363] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Advances in synthetic biology have provided genetic tools to reprogram cells to obtain desired cellular functions that include tools to enable the customization of cells to sense an extracellular signal and respond with a desired output. These include a variety of engineered receptors capable of transmembrane signaling that transmit information from outside of the cell to inside when specific ligands bind to them. Recent advances in synthetic receptor engineering have enabled the reprogramming of cell and tissue behavior, controlling cell fate decisions, and providing new vehicles for therapeutic delivery.
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Affiliation(s)
- Shwan B. Javdan
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT
| | - Tara L. Deans
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT
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10
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Santos-Moreno J, Schaerli Y. CRISPR-based gene expression control for synthetic gene circuits. Biochem Soc Trans 2020; 48:1979-1993. [PMID: 32964920 PMCID: PMC7609024 DOI: 10.1042/bst20200020] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 08/27/2020] [Accepted: 08/28/2020] [Indexed: 12/22/2022]
Abstract
Synthetic gene circuits allow us to govern cell behavior in a programmable manner, which is central to almost any application aiming to harness engineered living cells for user-defined tasks. Transcription factors (TFs) constitute the 'classic' tool for synthetic circuit construction but some of their inherent constraints, such as insufficient modularity, orthogonality and programmability, limit progress in such forward-engineering endeavors. Here we review how CRISPR (clustered regularly interspaced short palindromic repeats) technology offers new and powerful possibilities for synthetic circuit design. CRISPR systems offer superior characteristics over TFs in many aspects relevant to a modular, predictable and standardized circuit design. Thus, the choice of CRISPR technology as a framework for synthetic circuit design constitutes a valid alternative to complement or replace TFs in synthetic circuits and promises the realization of more ambitious designs.
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Affiliation(s)
- Javier Santos-Moreno
- Department of Fundamental Microbiology, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland
| | - Yolanda Schaerli
- Department of Fundamental Microbiology, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland
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11
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Kim H, Jin X, Glass DS, Riedel-Kruse IH. Engineering and modeling of multicellular morphologies and patterns. Curr Opin Genet Dev 2020; 63:95-102. [PMID: 32629326 DOI: 10.1016/j.gde.2020.05.039] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 04/30/2020] [Accepted: 05/07/2020] [Indexed: 12/22/2022]
Abstract
Synthetic multicellular (MC) systems have the capacity to increase our understanding of biofilms and higher organisms, and to serve as engineering platforms for developing complex products in the areas of medicine, biosynthesis and smart materials. Here we provide an interdisciplinary perspective and review on emerging approaches to engineer and model MC systems. We lay out definitions for key terms in the field and identify toolboxes of standardized parts which can be combined into various MC algorithms to achieve specific outcomes. Many essential parts and algorithms have been demonstrated in some form. As key next milestones for the field, we foresee the improvement of these parts and their adaptation to more biological systems, the demonstration of more complex algorithms, the advancement of quantitative modeling approaches and compilers to support rational MC engineering, and implementation of MC engineering for practical applications.
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Affiliation(s)
- Honesty Kim
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, USA
| | | | - David S Glass
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
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12
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Safaei M, Mobini GR, Abiri A, Shojaeian A. Synthetic biology in various cellular and molecular fields: applications, limitations, and perspective. Mol Biol Rep 2020; 47:6207-6216. [PMID: 32507922 DOI: 10.1007/s11033-020-05565-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Accepted: 05/28/2020] [Indexed: 01/10/2023]
Abstract
Synthetic biology breakthroughs have facilitated genetic circuit engineering to program cells through novel biological functions, dynamic gene expressions, as well as logic controls. SynBio can also participate in the rapid development of new treatments required for the human lifestyle. Moreover, these technologies are applied in the development of innovative therapeutic, diagnostic, as well as discovery-related methods within a wide range of cellular and molecular applications. In the present review study, SynBio applications in various cellular and molecular fields such as novel strategies for cancer therapy, biosensing, metabolic engineering, protein engineering, and tissue engineering were highlighted and summarized. The major safety and regulatory concerns about synthetic biology will be the environmental release, legal concerns, and risks of the engineered organisms. The final sections focused on limitations to SynBio.
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Affiliation(s)
- Mohsen Safaei
- Department of Medical Biotechnology, School of Advanced Technologies, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Gholam-Reza Mobini
- Cellular and Molecular Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Ardavan Abiri
- Department of Medicinal Chemistry, Faculty of Pharmacy, Kerman University of Medical Sciences, Kerman, Iran
| | - Ali Shojaeian
- Department of Molecular Medicine, School of Advanced Technologies, Shahrekord University of Medical Sciences, Shahrekord, Iran.
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13
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Gramelsberger G. Synthetic Morphology: A Vision of Engineering Biological Form. JOURNAL OF THE HISTORY OF BIOLOGY 2020; 53:295-309. [PMID: 32358710 DOI: 10.1007/s10739-020-09601-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Morphological engineering is an emerging research area in synthetic biology. In 2008 "synthetic morphology" was proposed as a prospective approach to engineering self-constructing anatomies by Jamie A. Davies of the University of Edinburgh. Synthetic morphology can establish a new paradigm, according to Davies, insofar as "cells can be programmed to organize themselves into specific, designed arrangements, structures and tissues." It is obvious that this new approach will extrapolate morphology into a new realm beyond the traditional logic of morphological research. However, synthetic morphology is a highly idealized vision of morphology which derives its visionary ideas from morphological engineering and mathematical idealizations in order to understand the principles of molecular morphology. Thus, the question is, if this approach will help to understand morphogenesis better or if it will just enable biologists to engineer morphogenesis. The paper investigates the development of synthetic morphology and its relation to synthetic biology as well as its epistemic gains.
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Barbier I, Perez‐Carrasco R, Schaerli Y. Controlling spatiotemporal pattern formation in a concentration gradient with a synthetic toggle switch. Mol Syst Biol 2020; 16:e9361. [PMID: 32529808 PMCID: PMC7290156 DOI: 10.15252/msb.20199361] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 04/29/2020] [Accepted: 05/08/2020] [Indexed: 11/20/2022] Open
Abstract
The formation of spatiotemporal patterns of gene expression is frequently guided by gradients of diffusible signaling molecules. The toggle switch subnetwork, composed of two cross-repressing transcription factors, is a common component of gene regulatory networks in charge of patterning, converting the continuous information provided by the gradient into discrete abutting stripes of gene expression. We present a synthetic biology framework to understand and characterize the spatiotemporal patterning properties of the toggle switch. To this end, we built a synthetic toggle switch controllable by diffusible molecules in Escherichia coli. We analyzed the patterning capabilities of the circuit by combining quantitative measurements with a mathematical reconstruction of the underlying dynamical system. The toggle switch can produce robust patterns with sharp boundaries, governed by bistability and hysteresis. We further demonstrate how the hysteresis, position, timing, and precision of the boundary can be controlled, highlighting the dynamical flexibility of the circuit.
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Affiliation(s)
- Içvara Barbier
- Department of Fundamental MicrobiologyUniversity of LausanneLausanneSwitzerland
| | - Rubén Perez‐Carrasco
- Department of Life SciencesImperial College LondonSouth Kensington CampusLondonUK
- Department of MathematicsUniversity College LondonLondonUK
| | - Yolanda Schaerli
- Department of Fundamental MicrobiologyUniversity of LausanneLausanneSwitzerland
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15
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Perkins ML, Benzinger D, Arcak M, Khammash M. Cell-in-the-loop pattern formation with optogenetically emulated cell-to-cell signaling. Nat Commun 2020; 11:1355. [PMID: 32170129 PMCID: PMC7069979 DOI: 10.1038/s41467-020-15166-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 02/11/2020] [Indexed: 12/22/2022] Open
Abstract
Designing and implementing synthetic biological pattern formation remains challenging due to underlying theoretical complexity as well as the difficulty of engineering multicellular networks biochemically. Here, we introduce a cell-in-the-loop approach where living cells interact through in silico signaling, establishing a new testbed to interrogate theoretical principles when internal cell dynamics are incorporated rather than modeled. We present an easy-to-use theoretical test to predict the emergence of contrasting patterns in gene expression among laterally inhibiting cells. Guided by the theory, we experimentally demonstrate spontaneous checkerboard patterning in an optogenetic setup, where cell-to-cell signaling is emulated with light inputs calculated in silico from real-time gene expression measurements. The scheme successfully produces spontaneous, persistent checkerboard patterns for systems of sixteen patches, in quantitative agreement with theoretical predictions. Our research highlights how tools from dynamical systems theory may inform our understanding of patterning, and illustrates the potential of cell-in-the-loop for engineering synthetic multicellular systems.
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Affiliation(s)
- Melinda Liu Perkins
- Department of Electrical Engineering, University of California, Berkeley, CA, USA.
| | - Dirk Benzinger
- Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland
| | - Murat Arcak
- Department of Electrical Engineering, University of California, Berkeley, CA, USA
| | - Mustafa Khammash
- Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland.
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16
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El Karoui M, Hoyos-Flight M, Fletcher L. Future Trends in Synthetic Biology-A Report. Front Bioeng Biotechnol 2019; 7:175. [PMID: 31448268 PMCID: PMC6692427 DOI: 10.3389/fbioe.2019.00175] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 07/08/2019] [Indexed: 11/20/2022] Open
Abstract
Leading researchers working on synthetic biology and its applications gathered at the University of Edinburgh in May 2018 to discuss the latest challenges and opportunities in the field. In addition to the potential socio-economic benefits of synthetic biology, they also examined the ethics and security risks arising from the development of these technologies. Speakers from industry, academia and not-for-profit organizations presented their vision for the future of the field and provided guidance to funding and regulatory bodies to ensure that synthetic biology research is carried out responsibly and can realize its full potential. This report aims to capture the collective views and recommendations that emerged from the discussions that took place. The meeting was held under the Chatham House Rule (i.e., a private invite-only meeting where comments can be freely used but not attributed) to promote open discussion; the findings and quotes included in the report are therefore not attributed to individuals. The goal of the meeting was to identify research priorities and bottlenecks. It also provided the opportunity to discuss how best to manage risk and earn public acceptance of this emerging and disruptive technology.
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Affiliation(s)
- Meriem El Karoui
- SynthSys-Centre for Synthetic and Systems Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Monica Hoyos-Flight
- Innogen Institute, School of Social and Political Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Liz Fletcher
- SynthSys-Centre for Synthetic and Systems Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
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17
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Blaeser A, Heilshorn SC, Duarte Campos DF. Smart Bioinks as de novo Building Blocks to Bioengineer Living Tissues. Gels 2019; 5:E29. [PMID: 31121889 PMCID: PMC6630496 DOI: 10.3390/gels5020029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Revised: 05/16/2019] [Accepted: 05/20/2019] [Indexed: 02/06/2023] Open
Abstract
In vitro tissues and 3D in vitro models have come of age [...].
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Affiliation(s)
- Andreas Blaeser
- Medical Textiles and Biofabrication, RWTH Aachen University, 52074 Aachen, Germany.
| | - Sarah C Heilshorn
- Department of Materials Science & Engineering, Stanford University, Stanford, CA 94305, USA.
| | - Daniela F Duarte Campos
- Department of Materials Science & Engineering, Stanford University, Stanford, CA 94305, USA.
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Using Sacrificial Cell Spheroids for the Bioprinting of Perfusable 3D Tissue and Organ Constructs: A Computational Study. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2019; 2019:7853586. [PMID: 31236128 PMCID: PMC6545789 DOI: 10.1155/2019/7853586] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 05/06/2019] [Indexed: 12/12/2022]
Abstract
A long-standing problem in tissue engineering is the biofabrication of perfusable tissue constructs that can be readily connected to the patient's vasculature. It was partially solved by three-dimensional (3D) printing of sacrificial material (e.g., hydrogel) strands: upon incorporation in another cell-laden hydrogel, the strands were removed, leaving behind perfusable channels. Their complexity, however, did not match that of the native vasculature. Here, we propose to use multicellular spheroids as a sacrificial material and investigate their potential benefits in the context of 3D bioprinting of cell aggregates and/or cell-laden hydrogels. Our study is based on computer simulations of postprinting cellular rearrangements. The computational model of the biological system is built on a cubic lattice, whereas its evolution is simulated using the Metropolis Monte Carlo algorithm. The simulations describe structural changes in three types of tissue constructs: a tube made of a single cell type, a tube made of two cell types, and a cell-laden hydrogel slab that incorporates a branching tube. In all three constructs, the lumen is obtained after the elimination of the sacrificial cell population. Our study suggests that sacrificial cell spheroids (sacrospheres) enable one to print tissue constructs outfitted with a finer and more complex network of channels than the ones obtained so far. Moreover, cellular interactions might give rise to a tissue microarchitecture that lies beyond the bioprinter's resolution. Although more expensive than inert materials, sacrificial cells have the potential to bring further progress towards the biofabrication of fully vascularized tissue substitutes.
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Abstract
Engineered systems that control cellular differentiation and pattern formation are essential for applications like tissue engineering, biomaterial fabrication, and synthetic ecosystems. Synthetic circuits that can take on multiple states have been made to engineer multicellular systems. However, how to use these states to drive interesting cellular behavior remains challenging. Here, we present a cellular differentiation program involving a novel synthetic bistable switch coupled to an antibiotic resistance gene that affects growth in yeast ( S. cerevisiae). The switch is composed of a positive feedback loop involving a novel transcription factor and can be switched ON and OFF via two different transient inducer inputs. By further coupling the bistable switch with an antibiotic resistance gene, we obtained a growth differentiation circuit, where yeast cells can be switched to stable HIGH or LOW growth rate states via transient inducer inputs. This work demonstrates a rationally designed and experimentally validated cellular differentiation behavior in yeast.
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Affiliation(s)
- Yaoyu Yang
- Department of Electrical and Computer Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Jennifer L. Nemhauser
- Department of Biology, University of Washington, Seattle, Washington 98195, United States
| | - Eric Klavins
- Department of Electrical and Computer Engineering, University of Washington, Seattle, Washington 98195, United States
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20
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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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21
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Abstract
Decoding how tissue properties emerge across multiple spatial and temporal scales from the integration of local signals is a grand challenge in quantitative biology. For example, the collective behavior of epithelial cells is critical for shaping developing embryos. Understanding how epithelial cells interpret a diverse range of local signals to coordinate tissue-level processes requires a systems-level understanding of development. Integration of multiple signaling pathways that specify cell signaling information requires second messengers such as calcium ions. Increasingly, specific roles have been uncovered for calcium signaling throughout development. Calcium signaling regulates many processes including division, migration, death, and differentiation. However, the pleiotropic and ubiquitous nature of calcium signaling implies that many additional functions remain to be discovered. Here we review a selection of recent studies to highlight important insights into how multiple signals are transduced by calcium transients in developing epithelial tissues. Quantitative imaging and computational modeling have provided important insights into how calcium signaling integration occurs. Reverse-engineering the conserved features of signal integration mediated by calcium signaling will enable novel approaches in regenerative medicine and synthetic control of morphogenesis.
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Affiliation(s)
- Pavel A. Brodskiy
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, 205 McCourtney Hall, Notre Dame, IN 46556, USA
| | - Jeremiah J. Zartman
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, 205 McCourtney Hall, Notre Dame, IN 46556, USA
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22
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Levin M, Martyniuk CJ. The bioelectric code: An ancient computational medium for dynamic control of growth and form. Biosystems 2018; 164:76-93. [PMID: 28855098 PMCID: PMC10464596 DOI: 10.1016/j.biosystems.2017.08.009] [Citation(s) in RCA: 108] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 08/20/2017] [Accepted: 08/22/2017] [Indexed: 12/19/2022]
Abstract
What determines large-scale anatomy? DNA does not directly specify geometrical arrangements of tissues and organs, and a process of encoding and decoding for morphogenesis is required. Moreover, many species can regenerate and remodel their structure despite drastic injury. The ability to obtain the correct target morphology from a diversity of initial conditions reveals that the morphogenetic code implements a rich system of pattern-homeostatic processes. Here, we describe an important mechanism by which cellular networks implement pattern regulation and plasticity: bioelectricity. All cells, not only nerves and muscles, produce and sense electrical signals; in vivo, these processes form bioelectric circuits that harness individual cell behaviors toward specific anatomical endpoints. We review emerging progress in reading and re-writing anatomical information encoded in bioelectrical states, and discuss the approaches to this problem from the perspectives of information theory, dynamical systems, and computational neuroscience. Cracking the bioelectric code will enable much-improved control over biological patterning, advancing basic evolutionary developmental biology as well as enabling numerous applications in regenerative medicine and synthetic bioengineering.
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Affiliation(s)
- Michael Levin
- Allen Discovery Center at Tufts University, Biology Department, Tufts University, 200 Boston Avenue, Suite 4600 Medford, MA 02155, USA.
| | - Christopher J Martyniuk
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida Genetics Institute, Interdisciplinary Program in Biomedical Sciences Neuroscience, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32611, USA
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23
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Midha S, Chawla S, Chakraborty J, Chameettachal S, Ghosh S. Differential Regulation of Hedgehog and Parathyroid Signaling in Mulberry and Nonmulberry Silk Fibroin Textile Braids. ACS Biomater Sci Eng 2018; 4:595-607. [DOI: 10.1021/acsbiomaterials.7b00874] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Swati Midha
- Regenerative Engineering
Laboratory, Department of Textile Technology, Indian Institute of Technology Delhi, New Delhi, India 110016
| | - Shikha Chawla
- Regenerative Engineering
Laboratory, Department of Textile Technology, Indian Institute of Technology Delhi, New Delhi, India 110016
| | - Juhi Chakraborty
- Regenerative Engineering
Laboratory, Department of Textile Technology, Indian Institute of Technology Delhi, New Delhi, India 110016
| | - Shibu Chameettachal
- Regenerative Engineering
Laboratory, Department of Textile Technology, Indian Institute of Technology Delhi, New Delhi, India 110016
| | - Sourabh Ghosh
- Regenerative Engineering
Laboratory, Department of Textile Technology, Indian Institute of Technology Delhi, New Delhi, India 110016
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24
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Johnson MB, March AR, Morsut L. Engineering multicellular systems: using synthetic biology to control tissue self-organization. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2017; 4:163-173. [PMID: 29308442 DOI: 10.1016/j.cobme.2017.10.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Marion B Johnson
- The Eli and Edythe Broad CIRM Center, Department of Stem Cell Biology and Regenerative Medicine University of Southern California Keck School of Medicine 1425 San Pablo Avenue, BCC-507, Los Angeles, 90033, USA
| | - Alexander R March
- The Eli and Edythe Broad CIRM Center, Department of Stem Cell Biology and Regenerative Medicine University of Southern California Keck School of Medicine 1425 San Pablo Avenue, BCC-507, Los Angeles, 90033, USA
| | - Leonardo Morsut
- The Eli and Edythe Broad CIRM Center, Department of Stem Cell Biology and Regenerative Medicine University of Southern California Keck School of Medicine 1425 San Pablo Avenue, BCC-507, Los Angeles, 90033, USA
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Cachat E, Liu W, Davies JA. Synthetic self‐patterning and morphogenesis in mammalian cells: a proof‐of‐concept step towards synthetic tissue development. ENGINEERING BIOLOGY 2017. [DOI: 10.1049/enb.2017.0013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Elise Cachat
- UK Centre for Mammalian Synthetic Biology University of Edinburgh Roger Land Building, King's Buildings Edinburgh EH9 3FF UK
| | - Weijia Liu
- Deanery of Biomedical Sciences University of Edinburgh Hugh Robson Building, George Square Edinburgh EH8 9XB UK
| | - Jamie A. Davies
- Deanery of Biomedical Sciences University of Edinburgh Hugh Robson Building, George Square Edinburgh EH8 9XB UK
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26
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Davies J. Using synthetic biology to explore principles of development. Development 2017; 144:1146-1158. [PMID: 28351865 DOI: 10.1242/dev.144196] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 02/14/2017] [Indexed: 12/31/2022]
Abstract
Developmental biology is mainly analytical: researchers study embryos, suggest hypotheses and test them through experimental perturbation. From the results of many experiments, the community distils the principles thought to underlie embryogenesis. Verifying these principles, however, is a challenge. One promising approach is to use synthetic biology techniques to engineer simple genetic or cellular systems that follow these principles and to see whether they perform as expected. As I review here, this approach has already been used to test ideas of patterning, differentiation and morphogenesis. It is also being applied to evo-devo studies to explore alternative mechanisms of development and 'roads not taken' by natural evolution.
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Affiliation(s)
- Jamie Davies
- Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XB, UK
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27
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From morphogen to morphogenesis and back. Nature 2017; 541:311-320. [DOI: 10.1038/nature21348] [Citation(s) in RCA: 206] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 11/18/2016] [Indexed: 12/11/2022]
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