1
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Kofman K, Levin M. Bioelectric pharmacology of cancer: A systematic review of ion channel drugs affecting the cancer phenotype. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2024; 191:25-39. [PMID: 38971325 DOI: 10.1016/j.pbiomolbio.2024.07.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 05/21/2024] [Accepted: 07/04/2024] [Indexed: 07/08/2024]
Abstract
Cancer is a pernicious and pressing medical problem; moreover, it is a failure of multicellular morphogenesis that sheds much light on evolutionary developmental biology. Numerous classes of pharmacological agents have been considered as cancer therapeutics and evaluated as potential carcinogenic agents; however, these are spread throughout the primary literature. Here, we briefly review recent work on ion channel drugs as promising anti-cancer treatments and present a systematic review of the known cancer-relevant effects of 109 drugs targeting ion channels. The roles of ion channels in cancer are consistent with the importance of bioelectrical parameters in cell regulation and with the functions of bioelectric signaling in morphogenetic signals that act as cancer suppressors. We find that compounds that are well-known for having targets in the nervous system, such as voltage-gated ion channels, ligand-gated ion channels, proton pumps, and gap junctions are especially relevant to cancer. Our review suggests further opportunities for the repurposing of numerous promising candidates in the field of cancer electroceuticals.
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Affiliation(s)
- Karina Kofman
- Faculty of Dentistry, University of Toronto, Toronto, Canada
| | - Michael Levin
- Allen Discovery Center at Tufts University, USA; Wyss Institute for Biologically Inspired Engineering at Harvard University, USA.
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2
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Norfleet DA, Melendez AJ, Alting C, Kannan S, Nikitina AA, Caldeira Botelho R, Yang B, Kemp ML. Identification of Distinct, Quantitative Pattern Classes from Emergent Tissue-Scale hiPSC Bioelectric Properties. Cells 2024; 13:1136. [PMID: 38994988 PMCID: PMC11240333 DOI: 10.3390/cells13131136] [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: 05/10/2024] [Revised: 06/17/2024] [Accepted: 06/20/2024] [Indexed: 07/13/2024] Open
Abstract
Bioelectric signals possess the ability to robustly control and manipulate patterning during embryogenesis and tissue-level regeneration. Endogenous local and global electric fields function as a spatial 'pre-pattern', controlling cell fates and tissue-scale anatomical boundaries; however, the mechanisms facilitating these robust multiscale outcomes are poorly characterized. Computational modeling addresses the need to predict in vitro patterning behavior and further elucidate the roles of cellular bioelectric signaling components in patterning outcomes. Here, we modified a previously designed image pattern recognition algorithm to distinguish unique spatial features of simulated non-excitable bioelectric patterns under distinct cell culture conditions. This algorithm was applied to comparisons between simulated patterns and experimental microscopy images of membrane potential (Vmem) across cultured human iPSC colonies. Furthermore, we extended the prediction to a novel co-culture condition in which cell sub-populations possessing different ionic fluxes were simulated; the defining spatial features were recapitulated in vitro with genetically modified colonies. These results collectively inform strategies for modeling multiscale spatial characteristics that emerge in multicellular systems, characterizing the molecular contributions to heterogeneity of membrane potential in non-excitable cells, and enabling downstream engineered bioelectrical tissue design.
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Affiliation(s)
- Dennis Andre Norfleet
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 950 Atlantic Dr. NW, Atlanta, GA 30332, USA
| | - Anja J Melendez
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 950 Atlantic Dr. NW, Atlanta, GA 30332, USA
| | - Caroline Alting
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 950 Atlantic Dr. NW, Atlanta, GA 30332, USA
| | - Siya Kannan
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 950 Atlantic Dr. NW, Atlanta, GA 30332, USA
| | - Arina A Nikitina
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA 931016, USA
| | - Raquel Caldeira Botelho
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 950 Atlantic Dr. NW, Atlanta, GA 30332, USA
| | - Bo Yang
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Melissa L Kemp
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 950 Atlantic Dr. NW, Atlanta, GA 30332, USA
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3
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Niraula D, El Naqa I, Tuszynski JA, Gatenby RA. Modeling non-genetic information dynamics in cells using reservoir computing. iScience 2024; 27:109614. [PMID: 38632985 PMCID: PMC11022048 DOI: 10.1016/j.isci.2024.109614] [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: 01/10/2024] [Revised: 03/15/2024] [Accepted: 03/26/2024] [Indexed: 04/19/2024] Open
Abstract
Virtually all cells use energy-driven, ion-specific membrane pumps to maintain large transmembrane gradients of Na+, K+, Cl-, Mg++, and Ca++, but the corresponding evolutionary benefit remains unclear. We propose that these gradients enable a dynamic and versatile biological system that acquires, analyzes, and responds to environmental information. We hypothesize that environmental signals are transmitted into the cell by ion fluxes along pre-existing gradients through gated ion-specific membrane channels. The consequent changes in cytoplasmic ion concentration can generate a local response or orchestrate global/regional cellular dynamics through wire-like ion fluxes along pre-existing and self-assembling cytoskeleton to engage the endoplasmic reticulum, mitochondria, and nucleus.
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Affiliation(s)
- Dipesh Niraula
- Department of Machine Learning, Moffitt Cancer Center, Tampa, FL, USA
| | - Issam El Naqa
- Department of Machine Learning, Moffitt Cancer Center, Tampa, FL, USA
| | - Jack Adam Tuszynski
- Departments of Physics and Oncology, University of Alberta, Edmonton, AB, Canada
- Department of Data Science and Engineering, The Silesian University of Technology, 44-100 Gliwice, Poland
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin 10129, Italy
| | - Robert A. Gatenby
- Departments of Radiology and Integrated Mathematical Oncology, Moffitt Cancer Center, Tampa, FL, USA
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4
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Mourokh L, Friedman J. Mitochondria at the Nanoscale: Physics Meets Biology-What Does It Mean for Medicine? Int J Mol Sci 2024; 25:2835. [PMID: 38474079 DOI: 10.3390/ijms25052835] [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: 02/03/2024] [Revised: 02/19/2024] [Accepted: 02/27/2024] [Indexed: 03/14/2024] Open
Abstract
Mitochondria are commonly perceived as "cellular power plants". Intriguingly, power conversion is not their only function. In the first part of this paper, we review the role of mitochondria in the evolution of eukaryotic organisms and in the regulation of the human body, specifically focusing on cancer and autism in relation to mitochondrial dysfunction. In the second part, we overview our previous works, revealing the physical principles of operation for proton-pumping complexes in the inner mitochondrial membrane. Our proposed simple models reveal the physical mechanisms of energy exchange. They can be further expanded to answer open questions about mitochondrial functions and the medical treatment of diseases associated with mitochondrial disorders.
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Affiliation(s)
- Lev Mourokh
- Physics Department, Queens College, The City University of New York, 65-30 Kissena Blvd. Flushing, New York, NY 11367, USA
| | - Jonathan Friedman
- Physics Department, Queens College, The City University of New York, 65-30 Kissena Blvd. Flushing, New York, NY 11367, USA
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5
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Jang HJ, Tiruneh DM, Ryu H, Yoon JK. Piezoelectric and Triboelectric Nanogenerators for Enhanced Wound Healing. Biomimetics (Basel) 2023; 8:517. [PMID: 37999158 PMCID: PMC10669670 DOI: 10.3390/biomimetics8070517] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 10/22/2023] [Accepted: 10/30/2023] [Indexed: 11/25/2023] Open
Abstract
Wound healing is a highly orchestrated biological process characterized by sequential phases involving inflammation, proliferation, and tissue remodeling, and the role of endogenous electrical signals in regulating these phases has been highlighted. Recently, external electrostimulation has been shown to enhance these processes by promoting cell migration, extracellular matrix formation, and growth factor release while suppressing pro-inflammatory signals and reducing the risk of infection. Among the innovative approaches, piezoelectric and triboelectric nanogenerators have emerged as the next generation of flexible and wireless electronics designed for energy harvesting and efficiently converting mechanical energy into electrical power. In this review, we discuss recent advances in the emerging field of nanogenerators for harnessing electrical stimulation to accelerate wound healing. We elucidate the fundamental mechanisms of wound healing and relevant bioelectric physiology, as well as the principles underlying each nanogenerator technology, and review their preclinical applications. In addition, we address the prominent challenges and outline the future prospects for this emerging era of electrical wound-healing devices.
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Affiliation(s)
- Hye-Jeong Jang
- Department of Systems Biotechnology, Chung-Ang University, Anseong-si 17546, Gyeonggi-do, Republic of Korea;
| | - Daniel Manaye Tiruneh
- Department of Intelligence Energy and Industry, Chung-Ang University, Seoul 06974, Republic of Korea;
| | - Hanjun Ryu
- Department of Intelligence Energy and Industry, Chung-Ang University, Seoul 06974, Republic of Korea;
- Department of Advanced Materials Engineering, Chung-Ang University, Anseong-si 17546, Gyeonggi-do, Republic of Korea
| | - Jeong-Kee Yoon
- Department of Systems Biotechnology, Chung-Ang University, Anseong-si 17546, Gyeonggi-do, Republic of Korea;
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Cervera J, Levin M, Mafe S. Correcting instructive electric potential patterns in multicellular systems: External actions and endogenous processes. Biochim Biophys Acta Gen Subj 2023; 1867:130440. [PMID: 37527731 DOI: 10.1016/j.bbagen.2023.130440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 06/19/2023] [Accepted: 07/28/2023] [Indexed: 08/03/2023]
Abstract
BACKGROUND Transmembrane electrical potential differences in cells modulate the spatio-temporal distribution of signaling ions and molecules that are instructive for downstream signaling pathways in multicellular systems. The local coupling between bioelectricity and protein transcription patterns allows dynamic subsystems (modules) of cells that share the same bioelectrical state to show similar biochemical downstream processes. METHODS We simulate theoretically how the integration-segregation pattern formed by the different multicellular modules that define a biosystem can be controlled by multicellular potentials. To this end, we couple together the model equations of the bioelectrical network to those of the genetic network. RESULTS The coupling provided by the intercellular junctions and the external microenvironment allows the restoration of the target bioelectrical pattern by changing the transcription rate of specific ion channels, the post-translational blocking of these channels, and changes in the environmental ionic concentrations. CONCLUSIONS The simulations show that the single-cell feedback between bioelectrical and transcriptional processes, together with the coupling provided by the intercellular junctions and the environment, can correct large-scale patterns by means of suitable external actions. GENERAL SIGNIFICANCE This study provides a theoretical advancement in the understanding of how the multicellular bioelectric coupling may guide repolarizing interventions for regenerating a tissue, with potential implications in biomedicine.
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Affiliation(s)
- Javier Cervera
- Dept. Termodinàmica, Facultat de Física, Universitat de València, E-46100 Burjassot, Spain.
| | - Michael Levin
- Dept. of Biology and Allen Discovery Center at Tufts University, Medford, USA; Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, USA
| | - Salvador Mafe
- Dept. Termodinàmica, Facultat de Física, Universitat de València, E-46100 Burjassot, Spain
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7
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Grodstein J, McMillen P, Levin M. Closing the loop on morphogenesis: a mathematical model of morphogenesis by closed-loop reaction-diffusion. Front Cell Dev Biol 2023; 11:1087650. [PMID: 37645245 PMCID: PMC10461482 DOI: 10.3389/fcell.2023.1087650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 07/31/2023] [Indexed: 08/31/2023] Open
Abstract
Morphogenesis, the establishment and repair of emergent complex anatomy by groups of cells, is a fascinating and biomedically-relevant problem. One of its most fascinating aspects is that a developing embryo can reliably recover from disturbances, such as splitting into twins. While this reliability implies some type of goal-seeking error minimization over a morphogenic field, there are many gaps with respect to detailed, constructive models of such a process. A common way to achieve reliability is negative feedback, which requires characterizing the existing body shape to create an error signal-but measuring properties of a shape may not be simple. We show how cells communicating in a wave-like pattern could analyze properties of the current body shape. We then describe a closed-loop negative-feedback system for creating reaction-diffusion (RD) patterns with high reliability. Specifically, we use a wave to count the number of peaks in a RD pattern, letting us use a negative-feedback controller to create a pattern with N repetitions, where N can be altered over a wide range. Furthermore, the individual repetitions of the RD pattern can be easily stretched or shrunk under genetic control to create, e.g., some morphological features larger than others. This work contributes to the exciting effort of understanding design principles of morphological computation, which can be used to understand evolved developmental mechanisms, manipulate them in regenerative-medicine settings, or engineer novel synthetic morphology constructs with desired robust behavior.
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Affiliation(s)
- Joel Grodstein
- Department of Electrical and Computer Engineering, Tufts University, Medford, MA, United States
| | - Patrick McMillen
- Allen Discovery Center at Tufts University, Medford, MA, United States
| | - Michael Levin
- Allen Discovery Center at Tufts University, Medford, MA, United States
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, MA, United States
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8
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Yamashita M. Integrin-mediated electric axon guidance underlying optic nerve formation in the embryonic chick retina. Commun Biol 2023; 6:680. [PMID: 37391492 PMCID: PMC10313674 DOI: 10.1038/s42003-023-05056-x] [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: 09/08/2022] [Accepted: 06/20/2023] [Indexed: 07/02/2023] Open
Abstract
Retinal ganglion cell (RGC) axons converge on the optic disc to form an optic nerve. However, the mechanism of RGC axon convergence remains elusive. In the embryonic retina, an electric field (EF) exists and this EF converges on the future optic disc. EFs have been demonstrated in vitro to orient axons toward the cathode. Here, I show that the EF directs RGC axons through integrin in an extracellular Ca2+-dependent manner. The cathodal growth of embryonic chick RGC axons, which express integrin α6β1, was enhanced by monoclonal anti-chicken integrin β1 antibodies. Mn2+ abolished these EF effects, as Mn2+ occupies the Ca2+-dependent negative regulatory site in the β1 subunit to eliminate Ca2+ inhibition. The present study proposes an integrin-mediated electric axon steering model, which involves directional Ca2+ movements and asymmetric microtubule stabilization. Since neuroepithelial cells generate EFs during neurogenesis, electric axon guidance may primarily be used in central nervous system development.
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9
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Mathews J, Chang A(J, Devlin L, Levin M. Cellular signaling pathways as plastic, proto-cognitive systems: Implications for biomedicine. PATTERNS (NEW YORK, N.Y.) 2023; 4:100737. [PMID: 37223267 PMCID: PMC10201306 DOI: 10.1016/j.patter.2023.100737] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Many aspects of health and disease are modeled using the abstraction of a "pathway"-a set of protein or other subcellular activities with specified functional linkages between them. This metaphor is a paradigmatic case of a deterministic, mechanistic framework that focuses biomedical intervention strategies on altering the members of this network or the up-/down-regulation links between them-rewiring the molecular hardware. However, protein pathways and transcriptional networks exhibit interesting and unexpected capabilities such as trainability (memory) and information processing in a context-sensitive manner. Specifically, they may be amenable to manipulation via their history of stimuli (equivalent to experiences in behavioral science). If true, this would enable a new class of biomedical interventions that target aspects of the dynamic physiological "software" implemented by pathways and gene-regulatory networks. Here, we briefly review clinical and laboratory data that show how high-level cognitive inputs and mechanistic pathway modulation interact to determine outcomes in vivo. Further, we propose an expanded view of pathways from the perspective of basal cognition and argue that a broader understanding of pathways and how they process contextual information across scales will catalyze progress in many areas of physiology and neurobiology. We argue that this fuller understanding of the functionality and tractability of pathways must go beyond a focus on the mechanistic details of protein and drug structure to encompass their physiological history as well as their embedding within higher levels of organization in the organism, with numerous implications for data science addressing health and disease. Exploiting tools and concepts from behavioral and cognitive sciences to explore a proto-cognitive metaphor for the pathways underlying health and disease is more than a philosophical stance on biochemical processes; at stake is a new roadmap for overcoming the limitations of today's pharmacological strategies and for inferring future therapeutic interventions for a wide range of disease states.
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Affiliation(s)
- Juanita Mathews
- Allen Discovery Center at Tufts University, Medford, MA, USA
| | | | - Liam Devlin
- Allen Discovery Center at Tufts University, Medford, MA, USA
| | - Michael Levin
- Allen Discovery Center at Tufts University, Medford, MA, USA
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, MA, USA
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10
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Buchner T, Zajdel M, Pȩczalski K, Nowak P. Finite velocity of ECG signal propagation: preliminary theory, results of a pilot experiment and consequences for medical diagnosis. Sci Rep 2023; 13:4716. [PMID: 36949077 PMCID: PMC10033722 DOI: 10.1038/s41598-023-29904-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 02/13/2023] [Indexed: 03/24/2023] Open
Abstract
A satisfactory model of the biopotentials propagating through the human body is essential for medical diagnostics, particularly for cardiovascular diseases. In our study, we develop the theory, that the propagation of biopotential of cardiac origin (ECG signal) may be treated as the propagation of low-frequency endogenous electromagnetic wave through the human body. We show that within this approach, the velocity of the ECG signal can be theoretically estimated, like for any other wave and physical medium, from the refraction index of the tissue in an appropriate frequency range. We confirm the theoretical predictions by the comparison with a direct measurement of the ECG signal propagation velocity and obtain mean velocity as low as v=1500 m/s. The results shed new light on our understanding of biopotential propagation through living tissue. This propagation depends on the frequency band of the signal and the transmittance of the tissue. This finding may improve the interpretation of the electric measurements, such as ECG and EEG when the frequency dependence of conductance and the phase shift introduced by the tissue is considered. We have shown, that the ECG propagation modifies the amplitude and phase of signal to a considerable extent. It may also improve the convergence of inverse problem in electrocardiographic imaging.
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Affiliation(s)
- Teodor Buchner
- Faculty of Physics, Warsaw University of Technology, Warsaw, Poland.
| | - Maryla Zajdel
- Faculty of Physics, Warsaw University of Technology, Warsaw, Poland
| | | | - Paweł Nowak
- Faculty of Mechatronics, Warsaw University of Technology, Warsaw, Poland
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11
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Hazan H, Levin M. Exploring the Behavior of Bioelectric Circuits Using Evolution Heuristic Search. Bioelectricity 2022. [DOI: 10.1089/bioe.2022.0033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- Hananel Hazan
- Allen Discovery Center at Tufts University, Medford, Massachusetts, USA
| | - Michael Levin
- Allen Discovery Center at Tufts University, Medford, Massachusetts, USA
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts, USA
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12
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Cable J, Arlotta P, Parker KK, Hughes AJ, Goodwin K, Mummery CL, Kamm RD, Engle SJ, Tagle DA, Boj SF, Stanton AE, Morishita Y, Kemp ML, Norfleet DA, May EE, Lu A, Bashir R, Feinberg AW, Hull SM, Gonzalez AL, Blatchley MR, Montserrat Pulido N, Morizane R, McDevitt TC, Mishra D, Mulero-Russe A. Engineering multicellular living systems-a Keystone Symposia report. Ann N Y Acad Sci 2022; 1518:183-195. [PMID: 36177947 PMCID: PMC9771928 DOI: 10.1111/nyas.14896] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The ability to engineer complex multicellular systems has enormous potential to inform our understanding of biological processes and disease and alter the drug development process. Engineering living systems to emulate natural processes or to incorporate new functions relies on a detailed understanding of the biochemical, mechanical, and other cues between cells and between cells and their environment that result in the coordinated action of multicellular systems. On April 3-6, 2022, experts in the field met at the Keystone symposium "Engineering Multicellular Living Systems" to discuss recent advances in understanding how cells cooperate within a multicellular system, as well as recent efforts to engineer systems like organ-on-a-chip models, biological robots, and organoids. Given the similarities and common themes, this meeting was held in conjunction with the symposium "Organoids as Tools for Fundamental Discovery and Translation".
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Affiliation(s)
| | - Paola Arlotta
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Kevin Kit Parker
- Wyss Institute for Biologically Inspired Engineering and John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA
- Harvard Stem Cell Institute, Harvard University, Cambridge, Massachusetts, USA
| | - Alex J Hughes
- Department of Bioengineering, School of Engineering and Applied Science and Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Katharine Goodwin
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, USA
| | - Christine L Mummery
- Department of Anatomy and Embryology and LUMC hiPSC Hotel, Leiden University Medical Center, Leiden, the Netherlands
| | - Roger D Kamm
- Department of Mechanical Engineering and Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Sandra J Engle
- Translational Biology, Biogen, Cambridge, Massachusetts, USA
| | - Danilo A Tagle
- National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland, USA
| | - Sylvia F Boj
- Hubrecht Organoid Technology (HUB), Utrecht, the Netherlands
| | - Alice E Stanton
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Yoshihiro Morishita
- Laboratory for Developmental Morphogeometry, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
- Precursory Research for Embryonic Science and Technology (PRESTO) Program, Japan Science and Technology Agency, Kawaguchi, Japan
| | - Melissa L Kemp
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA
| | - Dennis A Norfleet
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, USA
| | - Elebeoba E May
- Department of Biomedical Engineering and HEALTH Research Institute, University of Houston, Houston, Texas, USA
- Wisconsin Institute of Discovery and Department of Medical Microbiology & Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Aric Lu
- Wyss Institute for Biologically Inspired Engineering and John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA
- Draper Laboratory, Biological Engineering Division, Cambridge, Massachusetts, USA
| | - Rashid Bashir
- Beckman Institute for Advanced Science and Technology, Urbana, Illinois, USA
- Holonyak Micro & Nanotechnology Laboratory, Department of Electrical and Computer Engineering and Department of Bioengineering, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
| | - Adam W Feinberg
- Department of Biomedical Engineering and Department of Materials Science & Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| | - Sarah M Hull
- Department of Chemical Engineering, Stanford University, Stanford, California, USA
| | - Anjelica L Gonzalez
- Department of Biomedical Engineering, Yale University, New Haven, Connecticut, USA
| | - Michael R Blatchley
- BioFrontiers Institute and Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado, USA
| | | | - Ryuji Morizane
- Nephrology Division, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Todd C McDevitt
- The Gladstone Institutes and Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, California, USA
| | - Deepak Mishra
- Department of Biological Engineering, Synthetic Biology Center, Cambridge, Massachusetts, USA
- Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Adriana Mulero-Russe
- Parker H. Petit Institute for Bioengineering and Bioscience and School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA
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13
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Lam C, Saluja S, Courcoubetis G, Yu D, Chung C, Courte J, Morsut L. Parameterized Computational Framework for the Description and Design of Genetic Circuits of Morphogenesis Based on Contact-Dependent Signaling and Changes in Cell-Cell Adhesion. ACS Synth Biol 2022; 11:1417-1439. [PMID: 35363477 PMCID: PMC10389258 DOI: 10.1021/acssynbio.0c00369] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Synthetic development is a nascent field of research that uses the tools of synthetic biology to design genetic programs directing cellular patterning and morphogenesis in higher eukaryotic cells, such as mammalian cells. One specific example of such synthetic genetic programs was based on cell-cell contact-dependent signaling using synthetic Notch pathways and was shown to drive the formation of multilayered spheroids by modulating cell-cell adhesion via differential expression of cadherin family proteins in a mouse fibroblast cell line (L929). The design method for these genetic programs relied on trial and error, which limited the number of possible circuits and parameter ranges that could be explored. Here, we build a parameterized computational framework that, given a cell-cell communication network driving changes in cell adhesion and initial conditions as inputs, predicts developmental trajectories. We first built a general computational framework where contact-dependent cell-cell signaling networks and changes in cell-cell adhesion could be designed in a modular fashion. We then used a set of available in vitro results (that we call the "training set" in analogy to similar pipelines in the machine learning field) to parameterize the computational model with values for adhesion and signaling. We then show that this parameterized model can qualitatively predict experimental results from a "testing set" of available in vitro data that varied the genetic network in terms of adhesion combinations, initial number of cells, and even changes to the network architecture. Finally, this parameterized model is used to recommend novel network implementation for the formation of a four-layered structure that has not been reported previously. The framework that we develop here could function as a testing ground to identify the reachable space of morphologies that can be obtained by controlling contact-dependent cell-cell communications and adhesion with these molecular tools and in this cellular system. Additionally, we discuss how the model could be expanded to include other forms of communication or effectors for the computational design of the next generation of synthetic developmental trajectories.
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Affiliation(s)
- Calvin Lam
- Eli and Edythe Broad CIRM Center, Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California 90033-9080, United States
| | - Sajeev Saluja
- Eli and Edythe Broad CIRM Center, Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California 90033-9080, United States
| | - George Courcoubetis
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089-0484, United States
| | - Dottie Yu
- Eli and Edythe Broad CIRM Center, Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California 90033-9080, United States
| | - Christian Chung
- Eli and Edythe Broad CIRM Center, Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California 90033-9080, United States
| | - Josquin Courte
- Eli and Edythe Broad CIRM Center, Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California 90033-9080, United States
| | - Leonardo Morsut
- Eli and Edythe Broad CIRM Center, Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California 90033-9080, United States
- Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, California 90089-1111, United States
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14
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Grodstein J, Levin M. A Computational Approach to Explaining Bioelectrically Induced Persistent, Stochastic Changes of Axial Polarity in Planarian Regeneration. Bioelectricity 2022. [DOI: 10.1089/bioe.2021.0036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Joel Grodstein
- Department of Electrical and Computer Engineering, Tufts University, Medford, Massachusetts, USA
| | - Michael Levin
- Allen Discovery Center at Tufts University, Medford, Massachusetts, USA
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts, USA
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15
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Tassinari R, Cavallini C, Olivi E, Taglioli V, Zannini C, Ventura C. Unveiling the morphogenetic code: A new path at the intersection of physical energies and chemical signaling. World J Stem Cells 2021; 13:1382-1393. [PMID: 34786150 PMCID: PMC8567452 DOI: 10.4252/wjsc.v13.i10.1382] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 05/16/2021] [Accepted: 09/10/2021] [Indexed: 02/06/2023] Open
Abstract
In this editorial, we discuss the remarkable role of physical energies in the control of cell signaling networks and in the specification of the architectural plan of both somatic and stem cells. In particular, we focus on the biological relevance of bioelectricity in the pattern control that orchestrates both developmental and regenerative pathways. To this end, the narrative starts from the dawn of the first studies on animal electricity, reconsidering the pioneer work of Harold Saxton Burr in the light of the current achievements. We finally discuss the most recent evidence showing that bioelectric signaling is an essential component of the informational processes that control pattern specification during embryogenesis, regeneration, or even malignant transformation. We conclude that there is now mounting evidence for the existence of a Morphogenetic Code, and that deciphering this code may lead to unprecedented opportunities for the development of novel paradigms of cure in regenerative and precision medicine.
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Affiliation(s)
- Riccardo Tassinari
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems – ELDOR LAB, Bologna 40129, Italy
| | - Claudia Cavallini
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems – ELDOR LAB, Bologna 40129, Italy
| | - Elena Olivi
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems – ELDOR LAB, Bologna 40129, Italy
| | - Valentina Taglioli
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems – ELDOR LAB, Bologna 40129, Italy
| | - Chiara Zannini
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems – ELDOR LAB, Bologna 40129, Italy
| | - Carlo Ventura
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems – ELDOR LAB, Bologna 40129, Italy
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16
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Rame JE, Müller J. Myocardial Edema Revisited in a New Paradigm of Cardiac Electrical Microcurrent Application in Heart Failure. Bioelectricity 2021; 3:171-175. [PMID: 34729463 PMCID: PMC8558069 DOI: 10.1089/bioe.2021.0021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Undisturbed bioelectricity is a prerequisite for normal organ function. This is especially true for organs with high electrical activity such as the heart and the nervous system. Under clinical conditions, however, this can hardly be determined in patients with disturbed organ function and is therefore largely ignored. Here, based on clinical data, we will discuss whether the direct application of an external electric current (in the physiological μA range) together with an electrical field to hearts with impaired pump function can explain the functional improvement of the hearts by edema reduction triggered by electro-osmosis.
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Affiliation(s)
- Jesus Eduardo Rame
- Department of Medicine, Jefferson Heart Institute, Philadelphia, Pennsylvania, USA
| | - Johannes Müller
- Department of Bioelectricity and Medical Research, Berlin Heals, Berlin, Germany
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17
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Grodstein J, Levin M. Stability and robustness properties of bioelectric networks: A computational approach. BIOPHYSICS REVIEWS 2021; 2:031305. [PMID: 38505634 PMCID: PMC10903393 DOI: 10.1063/5.0062442] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 09/07/2021] [Indexed: 03/21/2024]
Abstract
Morphogenesis during development and regeneration requires cells to communicate and cooperate toward the construction of complex anatomical structures. One important set of mechanisms for coordinating growth and form occurs via developmental bioelectricity-the dynamics of cellular networks driving changes of resting membrane potential which interface with transcriptional and biomechanical downstream cascades. While many molecular details have been elucidated about the instructive processes mediated by ion channel-dependent signaling outside of the nervous system, future advances in regenerative medicine and bioengineering require the understanding of tissue, organ, or whole body-level properties. A key aspect of bioelectric networks is their robustness, which can drive correct, invariant patterning cues despite changing cell number and anatomical configuration of the underlying tissue network. Here, we computationally analyze the minimal models of bioelectric networks and use the example of the regenerating planarian flatworm, to reveal important system-level aspects of bioelectrically derived patterns. These analyses promote an understanding of the robustness of circuits controlling regeneration and suggest design properties that can be exploited for synthetic bioengineering.
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Affiliation(s)
- Joel Grodstein
- Department of Electrical and Computer Engineering, Tufts University, Medford, Massachusetts 02155, USA
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18
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Levin M. Bioelectrical approaches to cancer as a problem of the scaling of the cellular self. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2021; 165:102-113. [PMID: 33961843 DOI: 10.1016/j.pbiomolbio.2021.04.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 04/26/2021] [Accepted: 04/29/2021] [Indexed: 10/21/2022]
Abstract
One lens with which to understand the complex phenomenon of cancer is that of developmental biology. Cancer is the inevitable consequence of a breakdown of the communication that enables individual cells to join into computational networks that work towards large-scale, morphogenetic goals instead of more primitive, unicellular objectives. This perspective suggests that cancer may be a physiological disorder, not necessarily due to problems with the genetically-specified protein hardware. One aspect of morphogenetic coordination is bioelectric signaling, and indeed an abnormal bioelectric signature non-invasively reveals the site of incipient tumors in amphibian models. Functionally, a disruption of resting potential states triggers metastatic melanoma phenotypes in embryos with no genetic defects or carcinogen exposure. Conversely, optogenetic or molecular-biological modulation of bioelectric states can override powerful oncogenic mutations and prevent or normalize tumors. The bioelectrically-mediated information flows that harness cells toward body-level anatomical outcomes represent a very attractive and tractable endogenous control system, which is being targeted by emerging approaches to cancer.
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Affiliation(s)
- Michael Levin
- Allen Discovery Center at Tufts University, 200 Boston Ave., Suite 4600, Medford, MA, 02155, USA.
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19
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Bioelectric signaling: Reprogrammable circuits underlying embryogenesis, regeneration, and cancer. Cell 2021; 184:1971-1989. [PMID: 33826908 DOI: 10.1016/j.cell.2021.02.034] [Citation(s) in RCA: 117] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 01/08/2021] [Accepted: 02/16/2021] [Indexed: 12/16/2022]
Abstract
How are individual cell behaviors coordinated toward invariant large-scale anatomical outcomes in development and regeneration despite unpredictable perturbations? Endogenous distributions of membrane potentials, produced by ion channels and gap junctions, are present across all tissues. These bioelectrical networks process morphogenetic information that controls gene expression, enabling cell collectives to make decisions about large-scale growth and form. Recent progress in the analysis and computational modeling of developmental bioelectric circuits and channelopathies reveals how cellular collectives cooperate toward organ-level structural order. These advances suggest a roadmap for exploiting bioelectric signaling for interventions addressing developmental disorders, regenerative medicine, cancer reprogramming, and synthetic bioengineering.
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20
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Kosevic D, Wiedemann D, Vukovic P, Ristic V, Riebandt J, Radak U, Brandes K, Goettel P, Duengen H, Tahirovic E, Kottmann T, Voss HW, Zdravkovic M, Putnik S, Schmitto JD, Mueller J, Rame JE, Peric M. Cardio-microcurrent device for chronic heart failure: first-in-human clinical study. ESC Heart Fail 2021; 8:962-970. [PMID: 33559358 PMCID: PMC8006737 DOI: 10.1002/ehf2.13242] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 01/05/2021] [Accepted: 01/19/2021] [Indexed: 12/29/2022] Open
Abstract
AIMS Most devices for treating ambulatory Class II and III heart failure are linked to electrical pulses. However, a steady electric potential gradient is also necessary for appropriate myocardial performance and may be disturbed by structural heart diseases. We investigated whether chronic application of electrical microcurrent to the heart is feasible and safe and improves cardiac performance. The results of this study should provide guidance for the design of a two-arm, randomized, controlled Phase II trial. METHODS AND RESULTS This single-arm, non-randomized pilot study involved 10 patients (9 men; mean age, 62 ± 12 years) at two sites with 6 month follow-up. All patients had New York Heart Association (NYHA) Class III heart failure and non-ischaemic dilated cardiomyopathy, with left ventricular ejection fraction (LVEF) <35%. A device was surgically placed to deliver a constant microcurrent to the heart. The following tests were performed at baseline, at hospital discharge, and at six time points during follow-up: determination of LVEF and left ventricular end-diastolic/end-systolic diameter by echocardiography; the 6 min walk test; and assessment of NYHA classification and quality of life (36-Item Short-Form Health Survey questionnaire). Microcurrent application was feasible and safe; no device-related or treatment-related adverse events occurred. During follow-up, rapid and significant signal of efficacy (P < 0.005) was present with improvements in LVEF, left ventricular end-diastolic diameter, left ventricular end-systolic diameter, and distance walked. For eight patients, NYHA classification improved from Class III to Class I (for seven, as early as 14 days post-operatively); for one, to Class II; and for one, to Class II/III. 36-Item Short-Form Health Survey questionnaire scores also improved highly significantly. CONCLUSIONS Chronic application of microcurrent to the heart is feasible and safe and leads to a rapid and lasting improvement in heart function and a near normalization of heart size within days. The NYHA classification and quality of life improve just as rapidly.
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Affiliation(s)
| | | | - Petar Vukovic
- Cardiovascular Institute Dedinje BelgradeBelgradeSerbia
| | | | | | - Una Radak
- Cardiovascular Institute Dedinje BelgradeBelgradeSerbia
| | | | | | | | | | | | | | - Marija Zdravkovic
- University Hospital Medical Center Bezanijska Kosa BelgradeBelgradeSerbia
| | | | | | | | - Jesus Eduardo Rame
- Advanced Cardiac and Pulmonary Vascular Disease ProgramsJefferson Heart InstitutePhiladelphiaPAUSA
| | - Miodrag Peric
- Cardiovascular Institute Dedinje BelgradeBelgradeSerbia
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21
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Pezzulo G, LaPalme J, Durant F, Levin M. Bistability of somatic pattern memories: stochastic outcomes in bioelectric circuits underlying regeneration. Philos Trans R Soc Lond B Biol Sci 2021; 376:20190765. [PMID: 33550952 PMCID: PMC7935058 DOI: 10.1098/rstb.2019.0765] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/06/2020] [Indexed: 02/06/2023] Open
Abstract
Nervous systems' computational abilities are an evolutionary innovation, specializing and speed-optimizing ancient biophysical dynamics. Bioelectric signalling originated in cells' communication with the outside world and with each other, enabling cooperation towards adaptive construction and repair of multicellular bodies. Here, we review the emerging field of developmental bioelectricity, which links the field of basal cognition to state-of-the-art questions in regenerative medicine, synthetic bioengineering and even artificial intelligence. One of the predictions of this view is that regeneration and regulative development can restore correct large-scale anatomies from diverse starting states because, like the brain, they exploit bioelectric encoding of distributed goal states-in this case, pattern memories. We propose a new interpretation of recent stochastic regenerative phenotypes in planaria, by appealing to computational models of memory representation and processing in the brain. Moreover, we discuss novel findings showing that bioelectric changes induced in planaria can be stored in tissue for over a week, thus revealing that somatic bioelectric circuits in vivo can implement a long-term, re-writable memory medium. A consideration of the mechanisms, evolution and functionality of basal cognition makes novel predictions and provides an integrative perspective on the evolution, physiology and biomedicine of information processing in vivo. This article is part of the theme issue 'Basal cognition: multicellularity, neurons and the cognitive lens'.
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Affiliation(s)
- Giovanni Pezzulo
- Institute of Cognitive Sciences and Technologies, National Research Council, Rome, Italy
| | - Joshua LaPalme
- Allen Discovery Center, Tufts University, Medford, MA, USA
| | - Fallon Durant
- Allen Discovery Center, Tufts University, Medford, MA, USA
| | - Michael Levin
- Allen Discovery Center, Tufts University, Medford, MA, USA
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22
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Gawthrop PJ, Pan M. Network Thermodynamical Modeling of Bioelectrical Systems: A Bond Graph Approach. Bioelectricity 2021; 3:3-13. [PMID: 34476374 DOI: 10.1089/bioe.2020.0042] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Interactions among biomolecules, electrons, and protons are essential to many fundamental processes sustaining life. It is therefore of interest to build mathematical models of these bioelectrical processes not only to enhance understanding but also to enable computer models to complement in vitro and in vivo experiments. Such models can never be entirely accurate; it is nevertheless important that the models are compatible with physical principles. Network Thermodynamics, as implemented with bond graphs, provide one approach to creating physically compatible mathematical models of bioelectrical systems. This is illustrated using simple models of ion channels, redox reactions, proton pumps, and electrogenic membrane transporters thus demonstrating that the approach can be used to build mathematical and computer models of a wide range of bioelectrical systems.
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Affiliation(s)
- Peter J Gawthrop
- Systems Biology Laboratory, Department of Biomedical Engineering, Melbourne School of Engineering, University of Melbourne, Melbourne, Australia.,Systems Biology Laboratory, School of Mathematics and Statistics, University of Melbourne, Melbourne, Australia
| | - Michael Pan
- Systems Biology Laboratory, Department of Biomedical Engineering, Melbourne School of Engineering, University of Melbourne, Melbourne, Australia.,Systems Biology Laboratory, School of Mathematics and Statistics, University of Melbourne, Melbourne, Australia
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23
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Abstract
Embryogenesis, as well as regeneration, is increasingly recognized to be orchestrated by an interplay of transcriptional and bioelectric networks. Spatiotemporal patterns of resting potentials direct the size, shape, and locations of numerous organ primordia during patterning. These bioelectrical properties are established by the function of ion channels and pumps that set voltage potentials of individual cells, and gap junctions (electrical synapses) that enable physiological states to propagate across tissue networks. Functional experiments to probe the roles of bioelectrical states can be carried out by targeting endogenous ion channels during development. Here, we describe protocols, optimized for the highly tractable Xenopus laevis embryo, for molecular genetic targeting of ion channels and connexins based on CRISPR, and monitoring of resting potential states using voltage-sensing fluorescent dye. Similar strategies can be adapted to other model species.
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Affiliation(s)
- Vasilios Nanos
- Department of Biology, and Allen Discovery Center, Tufts University, Medford, MA, USA
| | - Michael Levin
- Department of Biology, and Allen Discovery Center, Tufts University, Medford, MA, USA.
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24
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Modeling the mechanobioelectricity of cell clusters. Biomech Model Mechanobiol 2020; 20:535-554. [PMID: 33145723 PMCID: PMC7979637 DOI: 10.1007/s10237-020-01399-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 10/16/2020] [Indexed: 10/31/2022]
Abstract
We propose a continuum finite strain theory for the interplay between the bioelectricity and the poromechanics of a cell cluster. Specifically, we refer to a cluster of closely packed cells, whose mechanics is governed by a polymer network of cytoskeletal filaments joined by anchoring junctions, modeled through compressible hyperelasticity. The cluster is saturated with a solution of water and ions. We account for water and ion transport in the intercellular spaces, between cells through gap junctions, and across cell membranes through aquaporins and ion channels. Water fluxes result from the contributions due to osmosis, electro-osmosis, and water pressure, while ion fluxes encompass electro-diffusive and convective terms. We consider both the cases of permeable and impermeable cluster boundary, the latter simulating the presence of sealing tight junctions. We solve the coupled governing equations for a one-dimensional axisymmetric benchmark through finite elements, thus determining the spatiotemporal evolution of the intracellular and extracellular ion concentrations, setting the membrane potential, and water concentrations, establishing the cluster deformation. When suitably complemented with genetic, biochemical, and growth dynamics, we expect this model to become a useful instrument for investigating specific aspects of developmental mechanobioelectricity.
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25
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Su Y, Chen W, Dorfmann L, Destrade M. The effect of an exterior electric field on the instability of dielectric plates. Proc Math Phys Eng Sci 2020; 476:20200267. [PMID: 32831614 DOI: 10.1098/rspa.2020.0267] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 06/05/2020] [Indexed: 11/12/2022] Open
Abstract
We investigate the theoretical nonlinear response, Hessian stability, and possible wrinkling behaviour of a voltage-activated dielectric plate immersed in a tank filled with silicone oil. Fixed rigid electrodes are placed on the top and bottom of the tank, and an electric field is generated by a potential difference between the electrodes. We solve the associated incremental boundary value problem of superimposed, inhomogeneous small-amplitude wrinkles, signalling the onset of instability. We decouple the resulting bifurcation equation into symmetric and antisymmetric modes. For a neo-Hookean dielectric plate, we show that a potential difference between the electrodes can induce a thinning of the plate and thus an increase of its planar area, similar to the scenarios encountered when there is no silicone oil. However, we also find that, depending on the material and geometric parameters, an increasing applied voltage can also lead to a thickening of the plate, and thus a shrinking of its area. In that scenario, Hessian instability and wrinkling bifurcation may then occur spontaneously once some critical voltages are reached.
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Affiliation(s)
- Yipin Su
- Department of Engineering Mechanics, Zhejiang University, Hangzhou 310027, People's Republic of China.,Stokes Centre for Applied Mathematics, School of Mathematics, Statistics and Applied Mathematics, NUI Galway, University Road, Galway, Ireland
| | - Weiqiu Chen
- Department of Engineering Mechanics, Zhejiang University, Hangzhou 310027, People's Republic of China
| | - Luis Dorfmann
- Department of Civil and Environmental Engineering, Tufts University, Medford, MA 02155, USA
| | - Michel Destrade
- Department of Engineering Mechanics, Zhejiang University, Hangzhou 310027, People's Republic of China.,Stokes Centre for Applied Mathematics, School of Mathematics, Statistics and Applied Mathematics, NUI Galway, University Road, Galway, Ireland
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26
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Hoel E, Levin M. Emergence of informative higher scales in biological systems: a computational toolkit for optimal prediction and control. Commun Integr Biol 2020; 13:108-118. [PMID: 33014263 PMCID: PMC7518458 DOI: 10.1080/19420889.2020.1802914] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 07/22/2020] [Accepted: 07/26/2020] [Indexed: 02/07/2023] Open
Abstract
The biological sciences span many spatial and temporal scales in attempts to understand the function and evolution of complex systems-level processes, such as embryogenesis. It is generally assumed that the most effective description of these processes is in terms of molecular interactions. However, recent developments in information theory and causal analysis now allow for the quantitative resolution of this question. In some cases, macro-scale models can minimize noise and increase the amount of information an experimenter or modeler has about "what does what." This result has numerous implications for evolution, pattern regulation, and biomedical strategies. Here, we provide an introduction to these quantitative techniques, and use them to show how informative macro-scales are common across biology. Our goal is to give biologists the tools to identify the maximally-informative scale at which to model, experiment on, predict, control, and understand complex biological systems.
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Affiliation(s)
- Erik Hoel
- Allen Discovery Center, Tufts University, Medford, MA, USA
| | - Michael Levin
- Allen Discovery Center, Tufts University, Medford, MA, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
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27
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Zhao S, Mehta AS, Zhao M. Biomedical applications of electrical stimulation. Cell Mol Life Sci 2020; 77:2681-2699. [PMID: 31974658 PMCID: PMC7954539 DOI: 10.1007/s00018-019-03446-1] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 12/12/2019] [Accepted: 12/27/2019] [Indexed: 12/14/2022]
Abstract
This review provides a comprehensive overview on the biomedical applications of electrical stimulation (EStim). EStim has a wide range of direct effects on both biomolecules and cells. These effects have been exploited to facilitate proliferation and functional development of engineered tissue constructs for regenerative medicine applications. They have also been tested or used in clinics for pain mitigation, muscle rehabilitation, the treatment of motor/consciousness disorders, wound healing, and drug delivery. However, the research on fundamental mechanism of cellular response to EStim has fell behind its applications, which has hindered the full exploitation of the clinical potential of EStim. Moreover, despite the positive outcome from the in vitro and animal studies testing the efficacy of EStim, existing clinical trials failed to establish strong, conclusive supports for the therapeutic efficacy of EStim for most of the clinical applications mentioned above. Two potential directions of future research to improve the clinical utility of EStim are presented, including the optimization and standardization of the stimulation protocol and the development of more tissue-matching devices.
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Affiliation(s)
- Siwei Zhao
- Mary and Dick Holland Regenerative Medicine Program, University of Nebraska Medical Center, 985965 Nebraska Medical Center, Omaha, NE, 68198, USA.
- Department of Surgery, University of Nebraska Medical Center, Nebraska Medical Center 985965, Omaha, NE, 68198, USA.
| | - Abijeet Singh Mehta
- Department of Dermatology, University of California, Davis, CA, USA
- Department of Ophthalmology & Vision Science, Institute for Regenerative Cures, Center for Neuroscience, University of California at Davis, School of Medicine, Suite 1630, Room 1617, 2921 Stockton Blvd., Sacramento, CA, 95817, USA
| | - Min Zhao
- Department of Dermatology, University of California, Davis, CA, USA
- Department of Ophthalmology & Vision Science, Institute for Regenerative Cures, Center for Neuroscience, University of California at Davis, School of Medicine, Suite 1630, Room 1617, 2921 Stockton Blvd., Sacramento, CA, 95817, USA
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28
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Silver BB, Wolf AE, Lee J, Pang MF, Nelson CM. Epithelial tissue geometry directs emergence of bioelectric field and pattern of proliferation. Mol Biol Cell 2020; 31:1691-1702. [PMID: 32520653 PMCID: PMC7521849 DOI: 10.1091/mbc.e19-12-0719] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Patterns of proliferation are templated by both gradients of mechanical stress as well as by gradients in membrane voltage (Vm), which is defined as the electric potential difference between the cytoplasm and the extracellular medium. Either gradient could regulate the emergence of the other, or they could arise independently and synergistically affect proliferation within a tissue. Here, we examined the relationship between endogenous patterns of mechanical stress and the generation of bioelectric gradients in mammary epithelial tissues. We observed that the mechanical stress gradients in the tissues presaged gradients in both proliferation and depolarization, consistent with previous reports correlating depolarization with proliferation. Furthermore, disrupting the Vm gradient blocked the emergence of patterned proliferation. We found that the bioelectric gradient formed downstream of mechanical stresses within the tissues and depended on connexin-43 (Cx43) hemichannels, which opened preferentially in cells located in regions of high mechanical stress. Activation of Cx43 hemichannels was necessary for nuclear localization of Yap/Taz and induction of proliferation. Together, these results suggest that mechanotransduction triggers the formation of bioelectric gradients across a tissue, which are further translated into transcriptional changes that template patterns of growth.
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Affiliation(s)
- Brian B Silver
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544
| | - Abraham E Wolf
- Department of Chemical & Biological Engineering, Princeton University, Princeton, NJ 08544
| | - Junuk Lee
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544
| | - Mei-Fong Pang
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544
| | - Celeste M Nelson
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544.,Department of Chemical & Biological Engineering, Princeton University, Princeton, NJ 08544
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29
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Leronni A, Bardella L, Dorfmann L, Pietak A, Levin M. On the coupling of mechanics with bioelectricity and its role in morphogenesis. J R Soc Interface 2020; 17:20200177. [PMID: 32486953 DOI: 10.1098/rsif.2020.0177] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The role of endogenous bioelectricity in morphogenesis has recently been explored through the finite volume-based code BioElectric Tissue Simulation Engine. We extend this platform to electrostatic and osmotic forces due to bioelectrical ion fluxes, causing cell cluster deformation. We further account for mechanosensitive ion channels, which, gated by membrane tension, modulate ion fluxes and, ultimately, bioelectrical forces. We illustrate the potentialities of this combined model of actuation and sensing with reference to cancer progression, osmoregulation, symmetry breaking and long-range signalling. This suggests control strategies for the manipulation of cell networks in vivo.
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Affiliation(s)
- A Leronni
- Department of Civil, Environmental, Architectural Engineering and Mathematics, University of Brescia, 25123 Brescia, Italy
| | - L Bardella
- Department of Civil, Environmental, Architectural Engineering and Mathematics, University of Brescia, 25123 Brescia, Italy
| | - L Dorfmann
- Department of Civil and Environmental Engineering, Tufts University, Medford, MA 02155, USA.,Department of Biomedical Engineering, Tufts University, Medford, MA 02155, USA
| | - A Pietak
- Allen Discovery Center, Tufts University, Medford, MA 02155, USA
| | - M Levin
- Allen Discovery Center, Tufts University, Medford, MA 02155, USA
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30
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Pai VP, Cervera J, Mafe S, Willocq V, Lederer EK, Levin M. HCN2 Channel-Induced Rescue of Brain Teratogenesis via Local and Long-Range Bioelectric Repair. Front Cell Neurosci 2020; 14:136. [PMID: 32528251 PMCID: PMC7264377 DOI: 10.3389/fncel.2020.00136] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 04/22/2020] [Indexed: 12/21/2022] Open
Abstract
Embryonic exposure to the teratogen nicotine results in brain defects, by disrupting endogenous spatial pre patterns necessary for normal brain size and patterning. Extending prior work in Xenopus laevis that showed that misexpression of ion channels can rescue morphogenesis, we demonstrate and characterize a novel aspect of developmental bioelectricity: channel-dependent repair signals propagate long-range across the embryo. We show that distal HCN2 channel misexpression and distal transplants of HCN2-expressing tissue, non-cell-autonomously reverse profound defects, rescuing brain anatomy, gene expression, and learning. Moreover, such rescue can be induced by small-molecule HCN2 channel activators, even with delayed treatment initiation. We present a simple, versatile computational model of bioelectrical signaling upstream of key patterning genes such as OTX2 and XBF1, which predicts long-range repair induced by ion channel activity, and experimentally validate the predictions of this model. Our results and quantitative model identify a powerful morphogenetic control mechanism that could be targeted by future regenerative medicine exploiting ion channel modulating drugs approved for human use.
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Affiliation(s)
- Vaibhav P Pai
- Allen Discovery Center at Tufts University, Medford, MA, United States
| | - Javier Cervera
- Departament de Termodinamica, Facultat de Fisica, Universitat de Valencia, Burjassot, Spain
| | - Salvador Mafe
- Departament de Termodinamica, Facultat de Fisica, Universitat de Valencia, Burjassot, Spain
| | - Valerie Willocq
- Allen Discovery Center at Tufts University, Medford, MA, United States
| | - Emma K Lederer
- Allen Discovery Center at Tufts University, Medford, MA, United States
| | - Michael Levin
- Allen Discovery Center at Tufts University, Medford, MA, United States.,Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, United States
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Lin L, Huang F, Yan H, Liu F, Guo W. Ant-Behavior Inspired Intelligent NanoNet for Targeted Drug Delivery in Cancer Therapy. IEEE Trans Nanobioscience 2020; 19:323-332. [PMID: 32248118 DOI: 10.1109/tnb.2020.2984940] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Targeted drug delivery system is believed as one of the most promising solutions for cancer treatment due to its low-dose requirement and less side effects. However, both passive targeting and active targeting rely on systemic blood circulation and diffusion, which is actually not the real "active" drug delivery. In this paper, an ant-behavior inspired nanonetwork composing of intelligent nanomachines is proposed. A big intelligent nanomachine take small intelligent nanomachines and drugs to the vicinity of of the tumor area. The small intelligent nanomachines can coordinate with each other to find the most effective path to the tumor cell for drug transportation. The framework and mechanism of this cooperative network are proposed. The route finding algorithm is presented. The convergence performance is analytically analyzed where the influence of the factors such as molecule degradation rate, home-destination distance, number of small nanomachines to the convergence is presented. Finally the simulation results validate the effectiveness of the proposed mechanism and analytical analysis.
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Abstract
Selective serotonin reuptake inhibitor (SSRI) drugs, targeting serotonin transport, are widely used. A puzzling and biomedically important phenomenon concerns the persistent sexual dysfunction following SSRI use seen in some patients. What could be the mechanism of a persistent physiological state brought on by a transient exposure to serotonin transport blockers? In this study, we briefly review the clinical facts concerning this side effect of serotonin reuptake inhibitors and suggest a possible mechanism. Bioelectric circuits (among neural or non-neural cells) could persistently maintain alterations of bioelectric cell properties (resting potential), resulting in long-term changes in electrophysiology and signaling. We present new data revealing this phenomenon in planarian flatworms, in which brief SSRI exposures induce long-lasting changes in resting potential profile. We also briefly review recent data linking neurotransmitter signaling to developmental bioelectrics. Further study of tissue bioelectric memory could enable the design of ionoceutical interventions to counteract side effects of SSRIs and similar drugs.
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Affiliation(s)
- David Healy
- Hergest Unit, Department of Psychiatry, Bangor University, Bangor, Wales
| | - Joshua LaPalme
- Allen Discovery Center, Tufts University, Medford, Massachusetts
| | - Michael Levin
- Allen Discovery Center, Tufts University, Medford, Massachusetts
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Levin M, Selberg J, Rolandi M. Endogenous Bioelectrics in Development, Cancer, and Regeneration: Drugs and Bioelectronic Devices as Electroceuticals for Regenerative Medicine. iScience 2019; 22:519-533. [PMID: 31837520 PMCID: PMC6920204 DOI: 10.1016/j.isci.2019.11.023] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 10/15/2019] [Accepted: 11/12/2019] [Indexed: 12/21/2022] Open
Abstract
A major frontier in the post-genomic era is the investigation of the control of coordinated growth and three-dimensional form. Dynamic remodeling of complex organs in regulative embryogenesis, regeneration, and cancer reveals that cells and tissues make decisions that implement complex anatomical outcomes. It is now essential to understand not only the genetics that specifies cellular hardware but also the physiological software that implements tissue-level plasticity and robust morphogenesis. Here, we review recent discoveries about the endogenous mechanisms of bioelectrical communication among non-neural cells that enables them to cooperate in vivo. We discuss important advances in bioelectronics, as well as computational and pharmacological tools that are enabling the taming of biophysical controls toward applications in regenerative medicine and synthetic bioengineering.
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Affiliation(s)
- Michael Levin
- Allen Discovery Center at Tufts University, Medford, MA 02155, USA.
| | - John Selberg
- Electrical and Computer Engineering Department, University of California, Santa Cruz, CA 95064, USA
| | - Marco Rolandi
- Electrical and Computer Engineering Department, University of California, Santa Cruz, CA 95064, USA
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Manicka S, Levin M. Modeling somatic computation with non-neural bioelectric networks. Sci Rep 2019; 9:18612. [PMID: 31819119 PMCID: PMC6901451 DOI: 10.1038/s41598-019-54859-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 11/13/2019] [Indexed: 02/08/2023] Open
Abstract
The field of basal cognition seeks to understand how adaptive, context-specific behavior occurs in non-neural biological systems. Embryogenesis and regeneration require plasticity in many tissue types to achieve structural and functional goals in diverse circumstances. Thus, advances in both evolutionary cell biology and regenerative medicine require an understanding of how non-neural tissues could process information. Neurons evolved from ancient cell types that used bioelectric signaling to perform computation. However, it has not been shown whether or how non-neural bioelectric cell networks can support computation. We generalize connectionist methods to non-neural tissue architectures, showing that a minimal non-neural Bio-Electric Network (BEN) model that utilizes the general principles of bioelectricity (electrodiffusion and gating) can compute. We characterize BEN behaviors ranging from elementary logic gates to pattern detectors, using both fixed and transient inputs to recapitulate various biological scenarios. We characterize the mechanisms of such networks using dynamical-systems and information-theory tools, demonstrating that logic can manifest in bidirectional, continuous, and relatively slow bioelectrical systems, complementing conventional neural-centric architectures. Our results reveal a variety of non-neural decision-making processes as manifestations of general cellular biophysical mechanisms and suggest novel bioengineering approaches to construct functional tissues for regenerative medicine and synthetic biology as well as new machine learning architectures.
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Affiliation(s)
- Santosh Manicka
- Allen Discovery Center, 200 College Ave., Tufts University, Medford, MA, 02155, USA
| | - Michael Levin
- Allen Discovery Center, 200 College Ave., Tufts University, Medford, MA, 02155, USA.
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Emmons-Bell M, Durant F, Tung A, Pietak A, Miller K, Kane A, Martyniuk CJ, Davidian D, Morokuma J, Levin M. Regenerative Adaptation to Electrochemical Perturbation in Planaria: A Molecular Analysis of Physiological Plasticity. iScience 2019; 22:147-165. [PMID: 31765995 PMCID: PMC6881696 DOI: 10.1016/j.isci.2019.11.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 10/01/2019] [Accepted: 11/05/2019] [Indexed: 12/29/2022] Open
Abstract
Anatomical homeostasis results from dynamic interactions between gene expression, physiology, and the external environment. Owing to its complexity, this cellular and organism-level phenotypic plasticity is still poorly understood. We establish planarian regeneration as a model for acquired tolerance to environments that alter endogenous physiology. Exposure to barium chloride (BaCl2) results in a rapid degeneration of anterior tissue in Dugesia japonica. Remarkably, continued exposure to fresh solution of BaCl2 results in regeneration of heads that are insensitive to BaCl2. RNA-seq revealed transcriptional changes in BaCl2-adapted heads that suggests a model of adaptation to excitotoxicity. Loss-of-function experiments confirmed several predictions: blockage of chloride and calcium channels allowed heads to survive initial BaCl2 exposure, inducing adaptation without prior exposure, whereas blockade of TRPM channels reversed adaptation. Such highly adaptive plasticity may represent an attractive target for biomedical strategies in a wide range of applications beyond its immediate relevance to excitotoxicity preconditioning. Exposure to BaCl2 causes the heads of Dugesia japonica to degenerate Prolonged exposure to BaCl2 results in regeneration of a BaCl2-insensitive head Ion channel expression is altered in the head to compensate for excitotoxic stress TRPMa is upregulated in BaCl2-treated animals; blocking TRPM prevents adaptation
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Affiliation(s)
- Maya Emmons-Bell
- Allen Discovery Center at Tufts University, Medford, MA 02155, USA; Department of Biology, Tufts University, Medford, MA 02155, USA
| | - Fallon Durant
- Allen Discovery Center at Tufts University, Medford, MA 02155, USA; Department of Biology, Tufts University, Medford, MA 02155, USA
| | - Angela Tung
- Allen Discovery Center at Tufts University, Medford, MA 02155, USA; Department of Biology, Tufts University, Medford, MA 02155, USA
| | - Alexis Pietak
- Allen Discovery Center at Tufts University, Medford, MA 02155, USA
| | - Kelsie Miller
- Allen Discovery Center at Tufts University, Medford, MA 02155, USA
| | - Anna Kane
- Allen Discovery Center at Tufts University, 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
| | - Devon Davidian
- Allen Discovery Center at Tufts University, Medford, MA 02155, USA; Department of Biology, Tufts University, Medford, MA 02155, USA
| | - Junji Morokuma
- Allen Discovery Center at Tufts University, Medford, MA 02155, USA; Department of Biology, Tufts University, Medford, MA 02155, USA
| | - Michael Levin
- Allen Discovery Center at Tufts University, Medford, MA 02155, USA; Department of Biology, Tufts University, Medford, MA 02155, USA.
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Toward Decoding Bioelectric Events in Xenopus Embryogenesis: New Methodology for Tracking Interplay Between Calcium and Resting Potentials In Vivo. J Mol Biol 2019; 432:605-620. [PMID: 31711960 DOI: 10.1016/j.jmb.2019.10.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 10/07/2019] [Accepted: 10/15/2019] [Indexed: 12/16/2022]
Abstract
Although chemical signaling during embryogenesis is readily addressed by a plethora of available techniques, the developmental functions of ionic signaling are still poorly understood. It is increasingly realized that bioelectric events in nonneural cells are critical for pattern regulation, but their study has been hampered by difficulties in monitoring and manipulating them in vivo. Recent developments in visualizing electrical signaling dynamics in the field of neuroscience have facilitated functional experiments that reveal instructive developmental bioelectric signals. However, there is a pressing need for additional tools to explore time-dependent ionic signaling to understand complex endogenous dynamics. Here, we present methodological advances, including 4D imaging and data analysis, for improved tracking of calcium flux in the Xenopus laevis embryo, lowering the barrier for in vivo physiology work in this important model system. Using these techniques, we investigated the relationship between bioelectric ion channel activity and calcium, finding that cell hyperpolarization and depolarization both induce persistent static elevation of cytoplasmic calcium levels that fade over developmental time. These calcium changes correlate with increased cell mobility in early embryos and abnormal craniofacial morphology in later embryos. We thus highlight membrane potential modulation as a tractable tool for modulation of signaling cascades that rely on calcium as a transduction mechanism. The methods we describe facilitate the study of important novel aspects of developmental physiology, are extendable to numerous classes of existing and forthcoming fluorescent physiological reporters, and establish highly accessible, inexpensive protocols for their investigation.
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Cervera J, Pai VP, Levin M, Mafe S. From non-excitable single-cell to multicellular bioelectrical states supported by ion channels and gap junction proteins: Electrical potentials as distributed controllers. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2019; 149:39-53. [PMID: 31255702 DOI: 10.1016/j.pbiomolbio.2019.06.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 06/26/2019] [Indexed: 12/18/2022]
Abstract
Endogenous bioelectric patterns within tissues are an important driver of morphogenesis and a tractable component of a number of disease states. Developing system-level understanding of the dynamics by which non-neural bioelectric circuits regulate complex downstream cascades is a key step towards both, an evolutionary understanding of ion channel genes, and novel strategies in regenerative medicine. An important capability gap is deriving rational modulation strategies targeting individual cells' bioelectric states to achieve global (tissue- or organ-level) outcomes. Here, we develop an ion channel-based model that describes multicellular states on the basis of spatio-temporal patterns of electrical potentials in aggregates of non-excitable cells. The model is of biological interest because modern techniques allow to associate bioelectrical signals with specific ion channel proteins in the cell membrane that are central to embryogenesis, regeneration, and tumorigenesis. As a complementary approach to the usual biochemical description, we have studied four biophysical questions: (i) how can single-cell bioelectrical states be established; (ii) how can a change in the cell potential caused by a transient perturbation of the cell state be maintained after the stimulus is gone (bioelectrical memory); (iii) how can a single-cell contribute to the control of multicellular ensembles based on the spatio-temporal pattern of electrical potentials; and (iv) how can oscillatory patterns arise from the single-cell bioelectrical dynamics. Experimentally, endogenous bioelectric gradients have emerged as instructive agents for morphogenetic processes. In this context, the simulations can guide new procedures that may allow a distributed control of the multicellular ensemble.
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Affiliation(s)
- Javier Cervera
- Dept. Termodinàmica, Universitat de València, E-46100, Burjassot, Spain.
| | - Vaibhav P Pai
- Dept. of Biology and Allen Discovery Center at Tufts University, Medford, MA, 02155-4243, USA
| | - Michael Levin
- Dept. of Biology and Allen Discovery Center at Tufts University, Medford, MA, 02155-4243, USA
| | - Salvador Mafe
- Dept. Termodinàmica, Universitat de València, E-46100, Burjassot, Spain
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Pietak A, Bischof J, LaPalme J, Morokuma J, Levin M. Neural control of body-plan axis in regenerating planaria. PLoS Comput Biol 2019; 15:e1006904. [PMID: 30990801 PMCID: PMC6485777 DOI: 10.1371/journal.pcbi.1006904] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 04/26/2019] [Accepted: 02/26/2019] [Indexed: 01/01/2023] Open
Abstract
Control of axial polarity during regeneration is a crucial open question. We developed a quantitative model of regenerating planaria, which elucidates self-assembly mechanisms of morphogen gradients required for robust body-plan control. The computational model has been developed to predict the fraction of heteromorphoses expected in a population of regenerating planaria fragments subjected to different treatments, and for fragments originating from different regions along the anterior-posterior and medio-lateral axis. This allows for a direct comparison between computational and experimental regeneration outcomes. Vector transport of morphogens was identified as a fundamental requirement to account for virtually scale-free self-assembly of the morphogen gradients observed in planarian homeostasis and regeneration. The model correctly describes altered body-plans following many known experimental manipulations, and accurately predicts outcomes of novel cutting scenarios, which we tested. We show that the vector transport field coincides with the alignment of nerve axons distributed throughout the planarian tissue, and demonstrate that the head-tail axis is controlled by the net polarity of neurons in a regenerating fragment. This model provides a comprehensive framework for mechanistically understanding fundamental aspects of body-plan regulation, and sheds new light on the role of the nervous system in directing growth and form.
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Affiliation(s)
- Alexis Pietak
- Allen Discovery Center, Tufts University, Medford, Massachusetts, United States of America
| | - Johanna Bischof
- Allen Discovery Center, Tufts University, Medford, Massachusetts, United States of America
- Department of Biology, Tufts University, Medford, Massachusetts, United States of America
| | - Joshua LaPalme
- Allen Discovery Center, Tufts University, Medford, Massachusetts, United States of America
- Department of Biology, Tufts University, Medford, Massachusetts, United States of America
| | - Junji Morokuma
- Allen Discovery Center, Tufts University, Medford, Massachusetts, United States of America
- Department of Biology, Tufts University, Medford, Massachusetts, United States of America
| | - Michael Levin
- Allen Discovery Center, Tufts University, Medford, Massachusetts, United States of America
- Department of Biology, Tufts University, Medford, Massachusetts, United States of America
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Levin M, Pietak AM, Bischof J. Planarian regeneration as a model of anatomical homeostasis: Recent progress in biophysical and computational approaches. Semin Cell Dev Biol 2019; 87:125-144. [PMID: 29635019 PMCID: PMC6234102 DOI: 10.1016/j.semcdb.2018.04.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 04/03/2018] [Accepted: 04/06/2018] [Indexed: 12/22/2022]
Abstract
Planarian behavior, physiology, and pattern control offer profound lessons for regenerative medicine, evolutionary biology, morphogenetic engineering, robotics, and unconventional computation. Despite recent advances in the molecular genetics of stem cell differentiation, this model organism's remarkable anatomical homeostasis provokes us with truly fundamental puzzles about the origin of large-scale shape and its relationship to the genome. In this review article, we first highlight several deep mysteries about planarian regeneration in the context of the current paradigm in this field. We then review recent progress in understanding of the physiological control of an endogenous, bioelectric pattern memory that guides regeneration, and how modulating this memory can permanently alter the flatworm's target morphology. Finally, we focus on computational approaches that complement reductive pathway analysis with synthetic, systems-level understanding of morphological decision-making. We analyze existing models of planarian pattern control and highlight recent successes and remaining knowledge gaps in this interdisciplinary frontier field.
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Affiliation(s)
- Michael Levin
- Allen Discovery Center at Tufts University, Medford, MA 02155, United States; Biology Department, Tufts University, Medford, MA 02155, United States.
| | - Alexis M Pietak
- Allen Discovery Center at Tufts University, Medford, MA 02155, United States
| | - Johanna Bischof
- Allen Discovery Center at Tufts University, Medford, MA 02155, United States; Biology Department, Tufts University, Medford, MA 02155, United States
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Churchill CDM, Winter P, Tuszynski JA, Levin M. EDEn-Electroceutical Design Environment: Ion Channel Tissue Expression Database with Small Molecule Modulators. iScience 2019; 11:42-56. [PMID: 30590250 PMCID: PMC6308252 DOI: 10.1016/j.isci.2018.12.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 10/22/2018] [Accepted: 12/06/2018] [Indexed: 02/06/2023] Open
Abstract
The emerging field of bioelectricity has revealed numerous new roles for ion channels beyond the nervous system, which can be exploited for applications in regenerative medicine. Developing such biomedical interventions for birth defects, cancer, traumatic injury, and bioengineering first requires knowledge of ion channel targets expressed in tissues of interest. This information can then be used to select combinations of small molecule inhibitors and/or activators that manipulate the bioelectric state. Here, we provide an overview of electroceutical design environment (EDEn), the first bioinformatic platform that facilitates the design of such therapeutic strategies. This database includes information on ion channels and ion pumps, linked to known chemical modulators and their properties. The database also provides information about the expression levels of the ion channels in over 100 tissue types. The graphical interface allows the user to readily identify chemical entities that can alter the electrical properties of target cells and tissues.
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Affiliation(s)
| | - Philip Winter
- Department of Oncology, University of Alberta, Edmonton, AB T6G 1Z2, Canada
| | - Jack A Tuszynski
- Department of Physics, University of Alberta, Edmonton, AB T6G 2E1, Canada; Department of Oncology, University of Alberta, Edmonton, AB T6G 1Z2, Canada
| | - Michael Levin
- Allen Discovery Center, Tufts University, 200 Boston Avenue, Suite 4600, Medford, MA 02155, USA.
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Cervera J, Manzanares JA, Mafe S. Cell-cell bioelectrical interactions and local heterogeneities in genetic networks: a model for the stabilization of single-cell states and multicellular oscillations. Phys Chem Chem Phys 2019; 20:9343-9354. [PMID: 29564429 DOI: 10.1039/c8cp00648b] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Genetic networks operate in the presence of local heterogeneities in single-cell transcription and translation rates. Bioelectrical networks and spatio-temporal maps of cell electric potentials can influence multicellular ensembles. Could cell-cell bioelectrical interactions mediated by intercellular gap junctions contribute to the stabilization of multicellular states against local genetic heterogeneities? We theoretically analyze this question on the basis of two well-established experimental facts: (i) the membrane potential is a reliable read-out of the single-cell electrical state and (ii) when the cells are coupled together, their individual cell potentials can be influenced by ensemble-averaged electrical potentials. We propose a minimal biophysical model for the coupling between genetic and bioelectrical networks that associates the local changes occurring in the transcription and translation rates of an ion channel protein with abnormally low (depolarized) cell potentials. We then analyze the conditions under which the depolarization of a small region (patch) in a multicellular ensemble can be reverted by its bioelectrical coupling with the (normally polarized) neighboring cells. We show also that the coupling between genetic and bioelectric networks of non-excitable cells, modulated by average electric potentials at the multicellular ensemble level, can produce oscillatory phenomena. The simulations show the importance of single-cell potentials characteristic of polarized and depolarized states, the relative sizes of the abnormally polarized patch and the rest of the normally polarized ensemble, and intercellular coupling.
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Affiliation(s)
- Javier Cervera
- Dept. Termodinàmica, Fac. Física, Universitat de València, 46100 Burjassot, Spain.
| | - José A Manzanares
- Dept. Termodinàmica, Fac. Física, Universitat de València, 46100 Burjassot, Spain.
| | - Salvador Mafe
- Dept. Termodinàmica, Fac. Física, Universitat de València, 46100 Burjassot, Spain.
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Dynamic intercellular transport modulates the spatial patterning of differentiation during early neural commitment. Nat Commun 2018; 9:4111. [PMID: 30291250 PMCID: PMC6173785 DOI: 10.1038/s41467-018-06693-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 09/17/2018] [Indexed: 01/01/2023] Open
Abstract
The initiation of heterogeneity within a population of phenotypically identical progenitors is a critical event for the onset of morphogenesis and differentiation patterning. Gap junction communication within multicellular systems produces complex networks of intercellular connectivity that result in heterogeneous distributions of intracellular signaling molecules. In this study, we investigate emergent systems-level behavior of the intercellular network within embryonic stem cell (ESC) populations and corresponding spatial organization during early neural differentiation. An agent-based model incorporates experimentally-determined parameters to yield complex transport networks for delivery of pro-differentiation cues between neighboring cells, reproducing the morphogenic trajectories during retinoic acid-accelerated mouse ESC differentiation. Furthermore, the model correctly predicts the delayed differentiation and preserved spatial features of the morphogenic trajectory that occurs in response to intercellular perturbation. These findings suggest an integral role of gap junction communication in the temporal coordination of emergent patterning during early differentiation and neural commitment of pluripotent stem cells.
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43
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Bioelectrical coupling in multicellular domains regulated by gap junctions: A conceptual approach. Bioelectrochemistry 2018; 123:45-61. [DOI: 10.1016/j.bioelechem.2018.04.013] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 04/13/2018] [Accepted: 04/17/2018] [Indexed: 12/16/2022]
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Moore DG, Valentini G, Walker SI, Levin M. Inform: Efficient Information-Theoretic Analysis of Collective Behaviors. Front Robot AI 2018; 5:60. [PMID: 33718436 PMCID: PMC7947678 DOI: 10.3389/frobt.2018.00060] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 05/03/2018] [Indexed: 01/28/2023] Open
Abstract
The study of collective behavior has traditionally relied on a variety of different methodological tools ranging from more theoretical methods such as population or game-theoretic models to empirical ones like Monte Carlo or multi-agent simulations. An approach that is increasingly being explored is the use of information theory as a methodological framework to study the flow of information and the statistical properties of collectives of interacting agents. While a few general purpose toolkits exist, most of the existing software for information theoretic analysis of collective systems is limited in scope. We introduce Inform, an open-source framework for efficient information theoretic analysis that exploits the computational power of a C library while simplifying its use through a variety of wrappers for common higher-level scripting languages. We focus on two such wrappers here: PyInform (Python) and rinform (R). Inform and its wrappers are cross-platform and general-purpose. They include classical information-theoretic measures, measures of information dynamics and information-based methods to study the statistical behavior of collective systems, and expose a lower-level API that allow users to construct measures of their own. We describe the architecture of the Inform framework, study its computational efficiency and use it to analyze three different case studies of collective behavior: biochemical information storage in regenerating planaria, nest-site selection in the ant Temnothorax rugatulus, and collective decision making in multi-agent simulations.
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Affiliation(s)
- Douglas G. Moore
- BEYOND: Center for Fundamental Concepts in Science, Arizona Sate University, Tempe, AZ, United States
| | - Gabriele Valentini
- BEYOND: Center for Fundamental Concepts in Science, Arizona Sate University, Tempe, AZ, United States
| | - Sara I. Walker
- BEYOND: Center for Fundamental Concepts in Science, Arizona Sate University, Tempe, AZ, United States
| | - Michael Levin
- Department of Biology, Allen Discovery Center, Tufts University, Medford, MA, United States
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Pai VP, Pietak A, Willocq V, Ye B, Shi NQ, Levin M. HCN2 Rescues brain defects by enforcing endogenous voltage pre-patterns. Nat Commun 2018. [PMID: 29519998 PMCID: PMC5843655 DOI: 10.1038/s41467-018-03334-5] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Endogenous bioelectrical signaling coordinates cell behaviors toward correct anatomical outcomes. Lack of a model explaining spatialized dynamics of bioelectric states has hindered the understanding of the etiology of some birth defects and the development of predictive interventions. Nicotine, a known neuroteratogen, induces serious defects in brain patterning and learning. Our bio-realistic computational model explains nicotine’s effects via the disruption of endogenous bioelectrical gradients and predicts that exogenous HCN2 ion channels would restore the endogenous bioelectric prepatterns necessary for brain patterning. Voltage mapping in vivo confirms these predictions, and exogenous expression of the HCN2 ion channel rescues nicotine-exposed embryos, resulting in normal brain morphology and molecular marker expression, with near-normal learning capacity. By combining molecular embryology, electrophysiology, and computational modeling, we delineate a biophysical mechanism of developmental brain damage and its functional rescue. The authors have previously shown that membrane voltage can influence embryonic patterning during development. Here, the authors computationally model how nicotine disrupts Xenopus embryogenesis by perturbing voltage gradients, and rescue nicotine-inducted defects with HCN2 channel expression.
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Affiliation(s)
- Vaibhav P Pai
- Allen Discovery Center at Tufts University, Medford, MA, 02155, USA
| | - Alexis Pietak
- Allen Discovery Center at Tufts University, Medford, MA, 02155, USA
| | - Valerie Willocq
- Allen Discovery Center at Tufts University, Medford, MA, 02155, USA
| | - Bin Ye
- Veridian Biotechnology Limited, Biotech Center 2, Hong Kong, China
| | - Nian-Qing Shi
- Department of Developmental, Molecular, and Chemical Biology, Tufts University, Boston, MA, 02111, USA
| | - Michael Levin
- Allen Discovery Center at Tufts University, Medford, MA, 02155, USA.
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46
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Silver BB, Nelson CM. The Bioelectric Code: Reprogramming Cancer and Aging From the Interface of Mechanical and Chemical Microenvironments. Front Cell Dev Biol 2018; 6:21. [PMID: 29560350 PMCID: PMC5845671 DOI: 10.3389/fcell.2018.00021] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 02/15/2018] [Indexed: 12/12/2022] Open
Abstract
Cancer is a complex, heterogeneous group of diseases that can develop through many routes. Broad treatments such as chemotherapy destroy healthy cells in addition to cancerous ones, but more refined strategies that target specific pathways are usually only effective for a limited number of cancer types. This is largely due to the multitude of physiological variables that differ between cells and their surroundings. It is therefore important to understand how nature coordinates these variables into concerted regulation of growth at the tissue scale. The cellular microenvironment might then be manipulated to drive cells toward a desired outcome at the tissue level. One unexpected parameter, cellular membrane voltage (Vm), has been documented to exert control over cellular behavior both in culture and in vivo. Manipulating this fundamental cellular property influences a remarkable array of organism-wide patterning events, producing striking outcomes in both tumorigenesis as well as regeneration. These studies suggest that Vm is not only a key intrinsic cellular property, but also an integral part of the microenvironment that acts in both space and time to guide cellular behavior. As a result, there is considerable interest in manipulating Vm both to treat cancer as well as to regenerate organs damaged or deteriorated during aging. However, such manipulations have produced conflicting outcomes experimentally, which poses a substantial barrier to understanding the fundamentals of bioelectrical reprogramming. Here, we summarize these inconsistencies and discuss how the mechanical microenvironment may impact bioelectric regulation.
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Affiliation(s)
- Brian B Silver
- Department of Molecular Biology, Princeton University, Princeton, NJ, United States
| | - Celeste M Nelson
- Department of Molecular Biology, Princeton University, Princeton, NJ, United States.,Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, United States
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Sullivan KG, Levin M. Inverse Drug Screening of Bioelectric Signaling and Neurotransmitter Roles: Illustrated Using a Xenopus Tail Regeneration Assay. Cold Spring Harb Protoc 2018; 2018:pdb.prot099937. [PMID: 29437995 DOI: 10.1101/pdb.prot099937] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Xenopus embryos and larvae are an ideal model system in which to study the interplay between genetics, physiology, and anatomy in the control of structure and function. An important emerging field is the study of bioelectric signaling, the exchange of ion- and neurotransmitter-mediated messages among all types of cells (not just nerve and muscle cells), in the regulation of growth and form during embryogenesis, regeneration, and cancer. To facilitate the mechanistic investigation of bioelectric events in vivo, it is necessary to identify the endogenous signaling machinery involved in any patterning process of interest. This protocol uses the tail regeneration assay in Xenopus to perform an inverse drug screen; tiers of known compounds are used to probe the involvement of increasingly specific classes of bioelectric and neurotransmitter machinery. By using a hierarchical approach, large classes of targets are ruled out in early rounds, focusing attention on progressively narrower sets of proteins. Such a screen avoids many of the limitations of a molecular-genetic targeting approach and provides a rapid and efficient way to focus on specific targets. Usually, <10 experiments are needed to determine whether bioelectrics and/or neurotransmitter signaling are involved in the process of interest. This protocol describes the strategy in the context of a semiquantitative analysis of tail regeneration but can be applied to any assay in Xenopus or other small aquatic model system (e.g., zebrafish). Given the ever-increasing toolkit of chemical genetics, such screens represent a powerful and versatile methodology for probing the physiological circuits underlying pattern regulation.
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Affiliation(s)
- Kelly G Sullivan
- Biology Department, and Allen Discovery Center at Tufts University, Medford, Massachusetts 02155
| | - Michael Levin
- Biology Department, and Allen Discovery Center at Tufts University, Medford, Massachusetts 02155
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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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Fields C, Levin M. Multiscale memory and bioelectric error correction in the cytoplasm-cytoskeleton-membrane system. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2017; 10. [DOI: 10.1002/wsbm.1410] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 08/19/2017] [Accepted: 10/04/2017] [Indexed: 12/12/2022]
Affiliation(s)
- Chris Fields
- 21 Rue des Lavandiéres, 11160 Caunes Minervois; France
| | - Michael Levin
- Allen Discovery Center at Tufts University; Medford MA USA
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50
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Pai VP, Willocq V, Pitcairn EJ, Lemire JM, Paré JF, Shi NQ, McLaughlin KA, Levin M. HCN4 ion channel function is required for early events that regulate anatomical left-right patterning in a nodal and lefty asymmetric gene expression-independent manner. Biol Open 2017; 6:1445-1457. [PMID: 28818840 PMCID: PMC5665463 DOI: 10.1242/bio.025957] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 08/12/2017] [Indexed: 12/13/2022] Open
Abstract
Laterality is a basic characteristic of all life forms, from single cell organisms to complex plants and animals. For many metazoans, consistent left-right asymmetric patterning is essential for the correct anatomy of internal organs, such as the heart, gut, and brain; disruption of left-right asymmetry patterning leads to an important class of birth defects in human patients. Laterality functions across multiple scales, where early embryonic, subcellular and chiral cytoskeletal events are coupled with asymmetric amplification mechanisms and gene regulatory networks leading to asymmetric physical forces that ultimately result in distinct left and right anatomical organ patterning. Recent studies have suggested the existence of multiple parallel pathways regulating organ asymmetry. Here, we show that an isoform of the hyperpolarization-activated cyclic nucleotide-gated (HCN) family of ion channels (hyperpolarization-activated cyclic nucleotide-gated channel 4, HCN4) is important for correct left-right patterning. HCN4 channels are present very early in Xenopus embryos. Blocking HCN channels (Ih currents) with pharmacological inhibitors leads to errors in organ situs. This effect is only seen when HCN4 channels are blocked early (pre-stage 10) and not by a later block (post-stage 10). Injections of HCN4-DN (dominant-negative) mRNA induce left-right defects only when injected in both blastomeres no later than the 2-cell stage. Analysis of key asymmetric genes' expression showed that the sidedness of Nodal, Lefty, and Pitx2 expression is largely unchanged by HCN4 blockade, despite the randomization of subsequent organ situs, although the area of Pitx2 expression was significantly reduced. Together these data identify a novel, developmental role for HCN4 channels and reveal a new Nodal-Lefty-Pitx2 asymmetric gene expression-independent mechanism upstream of organ positioning during embryonic left-right patterning.
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Affiliation(s)
- Vaibhav P Pai
- Allen Discovery Center at Tufts University, 200 Boston Ave, Suite 4600, Medford, MA 02155, USA
| | - Valerie Willocq
- Allen Discovery Center at Tufts University, 200 Boston Ave, Suite 4600, Medford, MA 02155, USA
| | - Emily J Pitcairn
- Allen Discovery Center at Tufts University, 200 Boston Ave, Suite 4600, Medford, MA 02155, USA
| | - Joan M Lemire
- Allen Discovery Center at Tufts University, 200 Boston Ave, Suite 4600, Medford, MA 02155, USA
| | - Jean-François Paré
- Allen Discovery Center at Tufts University, 200 Boston Ave, Suite 4600, Medford, MA 02155, USA
| | - Nian-Qing Shi
- Department of Medicine at University of Wisconsin-Madison, Madison, WI 53792, USA
| | - Kelly A McLaughlin
- Allen Discovery Center at Tufts University, 200 Boston Ave, Suite 4600, Medford, MA 02155, USA
| | - Michael Levin
- Allen Discovery Center at Tufts University, 200 Boston Ave, Suite 4600, Medford, MA 02155, USA
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