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Schwartzman JD, McCall M, Ghattas Y, Pugazhendhi AS, Wei F, Ngo C, Ruiz J, Seal S, Coathup MJ. Multifunctional scaffolds for bone repair following age-related biological decline: Promising prospects for smart biomaterial-driven technologies. Biomaterials 2024; 311:122683. [PMID: 38954959 DOI: 10.1016/j.biomaterials.2024.122683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 06/09/2024] [Accepted: 06/23/2024] [Indexed: 07/04/2024]
Abstract
The repair of large bone defects due to trauma, disease, and infection can be exceptionally challenging in the elderly. Despite best clinical practice, bone regeneration within contemporary, surgically implanted synthetic scaffolds is often problematic, inconsistent, and insufficient where additional osteobiological support is required to restore bone. Emergent smart multifunctional biomaterials may drive important and dynamic cellular crosstalk that directly targets, signals, stimulates, and promotes an innate bone repair response following age-related biological decline and when in the presence of disease or infection. However, their role remains largely undetermined. By highlighting their mechanism/s and mode/s of action, this review spotlights smart technologies that favorably align in their conceivable ability to directly target and enhance bone repair and thus are highly promising for future discovery for use in the elderly. The four degrees of interactive scaffold smartness are presented, with a focus on bioactive, bioresponsive, and the yet-to-be-developed autonomous scaffold activity. Further, cell- and biomolecular-assisted approaches were excluded, allowing for contemporary examination of the capabilities, demands, vision, and future requisites of next-generation biomaterial-induced technologies only. Data strongly supports that smart scaffolds hold significant promise in the promotion of bone repair in patients with a reduced osteobiological response. Importantly, many techniques have yet to be tested in preclinical models of aging. Thus, greater clarity on their proficiency to counteract the many unresolved challenges within the scope of aging bone is highly warranted and is arguably the next frontier in the field. This review demonstrates that the use of multifunctional smart synthetic scaffolds with an engineered strategy to circumvent the biological insufficiencies associated with aging bone is a viable route for achieving next-generation therapeutic success in the elderly population.
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Affiliation(s)
| | - Max McCall
- College of Medicine, University of Central Florida, Orlando, FL, USA
| | - Yasmine Ghattas
- College of Medicine, University of Central Florida, Orlando, FL, USA
| | - Abinaya Sindu Pugazhendhi
- College of Medicine, University of Central Florida, Orlando, FL, USA; Biionix Cluster, University of Central Florida, Orlando, FL, USA
| | - Fei Wei
- College of Medicine, University of Central Florida, Orlando, FL, USA; Biionix Cluster, University of Central Florida, Orlando, FL, USA
| | - Christopher Ngo
- College of Medicine, University of Central Florida, Orlando, FL, USA; Biionix Cluster, University of Central Florida, Orlando, FL, USA
| | - Jonathan Ruiz
- College of Medicine, University of Central Florida, Orlando, FL, USA
| | - Sudipta Seal
- College of Medicine, University of Central Florida, Orlando, FL, USA; Biionix Cluster, University of Central Florida, Orlando, FL, USA; Advanced Materials Processing and Analysis Centre, Nanoscience Technology Center (NSTC), Materials Science and Engineering, College of Medicine, University of Central Florida, USA, Orlando, FL
| | - Melanie J Coathup
- College of Medicine, University of Central Florida, Orlando, FL, USA; Biionix Cluster, University of Central Florida, Orlando, FL, USA.
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2
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Cervera J, Manzanares JA, Levin M, Mafe S. Oscillatory phenomena in electrophysiological networks: The coupling between cell bioelectricity and transcription. Comput Biol Med 2024; 180:108964. [PMID: 39106669 DOI: 10.1016/j.compbiomed.2024.108964] [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: 05/07/2024] [Revised: 07/04/2024] [Accepted: 07/27/2024] [Indexed: 08/09/2024]
Abstract
Morphogenetic regulation during embryogenesis and regeneration rely on information transfer and coordination between different regions. Here, we explore theoretically the coupling between bioelectrical and transcriptional oscillations at the individual cell and multicellular levels. The simulations, based on a set of ion channels and intercellular gap junctions, show that bioelectrical and transcriptional waves can electrophysiologically couple distant regions of a model network in phase and antiphase oscillatory states that include synchronization phenomena. In this way, different multicellular regionalizations can be encoded by cell potentials that oscillate between depolarized and polarized states, thus allowing a spatio-temporal coding. Because the electric potential patterns characteristic of development and regeneration are correlated with the spatial distributions of signaling ions and molecules, bioelectricity can act as a template for slow biochemical signals following a hierarchy of experimental times. In particular, bioelectrical gradients that couple cell potentials to transcription rates give to each single cell a rough idea of its location in the multicellular ensemble, thus controlling local differentiation processes that switch on and off crucial parts of the genome.
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Affiliation(s)
- Javier Cervera
- Dept. Termodinàmica, Facultat de Física, Universitat de València, 46100, Burjassot, Spain.
| | - José A Manzanares
- Dept. Termodinàmica, Facultat de Física, Universitat de València, 46100, Burjassot, Spain
| | - Michael Levin
- Dept. of Biology, Tufts University, Medford, MA, 02155, USA; Allen Discovery Center at Tufts University, Medford, MA, 02155, USA; Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02215, USA
| | - Salvador Mafe
- Dept. Termodinàmica, Facultat de Física, Universitat de València, 46100, Burjassot, Spain; Allen Discovery Center at Tufts University, Medford, MA, 02155, USA
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3
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Krutko M, Poling HM, Bryan AE, Sharma M, Singh A, Reza HA, Wikenheiser-Brokamp KA, Takebe T, Helmrath MA, Harris GM, Esfandiari L. Enhanced Piezoelectric Performance of PVDF-TrFE Nanofibers through Annealing for Tissue Engineering Applications. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.16.608345. [PMID: 39229142 PMCID: PMC11370437 DOI: 10.1101/2024.08.16.608345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2024]
Abstract
This study investigates bioelectric stimulation's role in tissue regeneration by enhancing the piezoelectric properties of tissue-engineered grafts using annealed poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE) scaffolds. Annealing at temperatures of 80°C, 100°C, 120°C, and 140°C was assessed for its impact on material properties and physiological utility. Analytical techniques such as Differential Scanning Calorimetry (DSC), Fourier-Transform Infrared Spectroscopy (FTIR), and X-ray Diffraction (XRD) revealed increased crystallinity with higher annealing temperatures, peaking in β-phase content and crystallinity at 140°C. Scanning Electron Microscopy (SEM) showed that 140°C annealed scaffolds had enhanced lamellar structures, increased porosity, and maximum piezoelectric response. Mechanical tests indicated that 140°C annealing improved elastic modulus, tensile strength, and substrate stiffness, aligning these properties with physiological soft tissues. In vitro assessments in Schwann cells demonstrated favorable responses, with increased cell proliferation, contraction, and extracellular matrix attachment. Additionally, genes linked to extracellular matrix production, vascularization, and calcium signaling were upregulated. The foreign body response in C57BL/6 mice, evaluated through Hematoxylin and Eosin (H&E) and Picrosirius Red staining, showed no differences between scaffold groups, supporting the potential for future functional evaluation of the annealed group in tissue repair.
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4
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Lukowicz-Bedford RM, Eisen JS, Miller AC. Gap-junction-mediated bioelectric signaling required for slow muscle development and function in zebrafish. Curr Biol 2024; 34:3116-3132.e5. [PMID: 38936363 PMCID: PMC11265983 DOI: 10.1016/j.cub.2024.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 04/11/2024] [Accepted: 06/04/2024] [Indexed: 06/29/2024]
Abstract
Bioelectric signaling, intercellular communication facilitated by membrane potential and electrochemical coupling, is emerging as a key regulator of animal development. Gap junction (GJ) channels can mediate bioelectric signaling by creating a fast, direct pathway between cells for the movement of ions and other small molecules. In vertebrates, GJ channels are formed by a highly conserved transmembrane protein family called the connexins. The connexin gene family is large and complex, creating challenges in identifying specific connexins that create channels within developing and mature tissues. Using the embryonic zebrafish neuromuscular system as a model, we identify a connexin conserved across vertebrate lineages, gjd4, which encodes the Cx46.8 protein, that mediates bioelectric signaling required for slow muscle development and function. Through mutant analysis and in vivo imaging, we show that gjd4/Cx46.8 creates GJ channels specifically in developing slow muscle cells. Using genetics, pharmacology, and calcium imaging, we find that spinal-cord-generated neural activity is transmitted to developing slow muscle cells, and synchronized activity spreads via gjd4/Cx46.8 GJ channels. Finally, we show that bioelectrical signal propagation within the developing neuromuscular system is required for appropriate myofiber organization and that disruption leads to defects in behavior. Our work reveals a molecular basis for GJ communication among developing muscle cells and reveals how perturbations to bioelectric signaling in the neuromuscular system may contribute to developmental myopathies. Moreover, this work underscores a critical motif of signal propagation between organ systems and highlights the pivotal role of GJ communication in coordinating bioelectric signaling during development.
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Affiliation(s)
| | - Judith S Eisen
- University of Oregon, Institute of Neuroscience, Eugene, OR 97405, USA
| | - Adam C Miller
- University of Oregon, Institute of Neuroscience, Eugene, OR 97405, USA.
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5
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Liberali P, Schier AF. The evolution of developmental biology through conceptual and technological revolutions. Cell 2024; 187:3461-3495. [PMID: 38906136 DOI: 10.1016/j.cell.2024.05.053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 05/28/2024] [Accepted: 05/29/2024] [Indexed: 06/23/2024]
Abstract
Developmental biology-the study of the processes by which cells, tissues, and organisms develop and change over time-has entered a new golden age. After the molecular genetics revolution in the 80s and 90s and the diversification of the field in the early 21st century, we have entered a phase when powerful technologies provide new approaches and open unexplored avenues. Progress in the field has been accelerated by advances in genomics, imaging, engineering, and computational biology and by emerging model systems ranging from tardigrades to organoids. We summarize how revolutionary technologies have led to remarkable progress in understanding animal development. We describe how classic questions in gene regulation, pattern formation, morphogenesis, organogenesis, and stem cell biology are being revisited. We discuss the connections of development with evolution, self-organization, metabolism, time, and ecology. We speculate how developmental biology might evolve in an era of synthetic biology, artificial intelligence, and human engineering.
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Affiliation(s)
- Prisca Liberali
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland; University of Basel, Basel, Switzerland.
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6
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Huang T, Zeng Y, Li C, Zhou Z, Xu J, Wang L, Yu DG, Wang K. Application and Development of Electrospun Nanofiber Scaffolds for Bone Tissue Engineering. ACS Biomater Sci Eng 2024; 10:4114-4144. [PMID: 38830819 DOI: 10.1021/acsbiomaterials.4c00028] [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] [Indexed: 06/05/2024]
Abstract
Nanofiber scaffolds have gained significant attention in the field of bone tissue engineering. Electrospinning, a straightforward and efficient technique for producing nanofibers, has been extensively researched. When used in bone tissue engineering scaffolds, electrospun nanofibers with suitable surface properties promote new bone tissue growth and enhance cell adhesion. Recent advancements in electrospinning technology have provided innovative approaches for scaffold fabrication in bone tissue engineering. This review comprehensively examines the utilization of electrospun nanofibers in bone tissue engineering scaffolds and evaluates the relevant literature. The review begins by presenting the fundamental principles and methodologies of electrospinning. It then discusses various materials used in the production of electrospun nanofiber scaffolds for bone tissue engineering, including natural and synthetic polymers, as well as certain inorganic materials. The challenges associated with these materials are also described. The review focuses on novel electrospinning techniques for scaffold construction in bone tissue engineering, such as multilayer nanofibers, multifluid electrospinning, and the integration of electrospinning with other methods. Recent advancements in electrospinning technology have enabled the fabrication of precisely aligned nanofiber scaffolds with nanoscale architectures. These innovative methods also facilitate the fabrication of biomimetic structures, wherein bioactive substances can be incorporated and released in a controlled manner for drug delivery purposes. Moreover, they address issues encountered with traditional electrospun nanofibers, such as mechanical characteristics and biocompatibility. Consequently, the development and implementation of novel electrospinning technologies have revolutionized scaffold fabrication for bone tissue engineering.
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Affiliation(s)
- Tianyue Huang
- School of Materials and Chemistry, University of Shanghai for Science and Technology 516 Jungong Road, Shanghai 200093, China
| | - YuE Zeng
- Department of Neurology, RuiJin Hospital Lu Wan Branch, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Chaofei Li
- Department of General Surgery, RuiJin Hospital Lu Wan Branch, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Zhengqing Zhou
- School of Materials and Chemistry, University of Shanghai for Science and Technology 516 Jungong Road, Shanghai 200093, China
| | - Jie Xu
- School of Materials and Chemistry, University of Shanghai for Science and Technology 516 Jungong Road, Shanghai 200093, China
| | - Lean Wang
- School of Materials and Chemistry, University of Shanghai for Science and Technology 516 Jungong Road, Shanghai 200093, China
| | - Deng-Guang Yu
- School of Materials and Chemistry, University of Shanghai for Science and Technology 516 Jungong Road, Shanghai 200093, China
| | - Ke Wang
- School of Materials and Chemistry, University of Shanghai for Science and Technology 516 Jungong Road, Shanghai 200093, China
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7
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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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8
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Luo S, Zhang C, Xiong W, Song Y, Wang Q, Zhang H, Guo S, Yang S, Liu H. Advances in electroactive biomaterials: Through the lens of electrical stimulation promoting bone regeneration strategy. J Orthop Translat 2024; 47:191-206. [PMID: 39040489 PMCID: PMC11261049 DOI: 10.1016/j.jot.2024.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 05/16/2024] [Accepted: 06/07/2024] [Indexed: 07/24/2024] Open
Abstract
The regenerative capacity of bone is indispensable for growth, given that accidental injury is almost inevitable. Bone regenerative capacity is relevant for the aging population globally and for the repair of large bone defects after osteotomy (e.g., following removal of malignant bone tumours). Among the many therapeutic modalities proposed to bone regeneration, electrical stimulation has attracted significant attention owing to its economic convenience and exceptional curative effects, and various electroactive biomaterials have emerged. This review summarizes the current knowledge and progress regarding electrical stimulation strategies for improving bone repair. Such strategies range from traditional methods of delivering electrical stimulation via electroconductive materials using external power sources to self-powered biomaterials, such as piezoelectric materials and nanogenerators. Electrical stimulation and osteogenesis are related via bone piezoelectricity. This review examines cell behaviour and the potential mechanisms of electrostimulation via electroactive biomaterials in bone healing, aiming to provide new insights regarding the mechanisms of bone regeneration using electroactive biomaterials. The translational potential of this article This review examines the roles of electroactive biomaterials in rehabilitating the electrical microenvironment to facilitate bone regeneration, addressing current progress in electrical biomaterials and the mechanisms whereby electrical cues mediate bone regeneration. Interactions between osteogenesis-related cells and electroactive biomaterials are summarized, leading to proposals regarding the use of electrical stimulation-based therapies to accelerate bone healing.
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Affiliation(s)
- Songyang Luo
- Department of Plastic Surgery, The First Hospital of China Medical University, Shenyang, 110001, China
- Liaoning Provincial Key Laboratory of Oral Diseases, School and Hospital of Stomatology, China Medical University, Shenyang, 110001, China
| | - Chengshuo Zhang
- Hepatobiliary Surgery Department, The First Hospital of China Medical University, Shenyang, 110001, China
| | - Wei Xiong
- Department of Plastic Surgery, The First Hospital of Shihezi Medical University, Shihezi, 832000, China
| | - Yiping Song
- Department of Plastic Surgery, The First Hospital of China Medical University, Shenyang, 110001, China
| | - Qiang Wang
- Liaoning Provincial Key Laboratory of Oral Diseases, School and Hospital of Stomatology, China Medical University, Shenyang, 110001, China
| | - Hangzhou Zhang
- Department of Orthopedics, The First Hospital of China Medical University, Shenyang Sports Medicine Clinical Medical Research Center, Shenyang, 110001, China
| | - Shu Guo
- Department of Plastic Surgery, The First Hospital of China Medical University, Shenyang, 110001, China
| | - Shude Yang
- Department of Plastic Surgery, The First Hospital of China Medical University, Shenyang, 110001, China
- Liaoning Provincial Key Laboratory of Oral Diseases, School and Hospital of Stomatology, China Medical University, Shenyang, 110001, China
| | - Huanye Liu
- Liaoning Provincial Key Laboratory of Oral Diseases, School and Hospital of Stomatology, China Medical University, Shenyang, 110001, China
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9
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Pio-Lopez L, Levin M. Aging as a loss of morphostatic information: A developmental bioelectricity perspective. Ageing Res Rev 2024; 97:102310. [PMID: 38636560 DOI: 10.1016/j.arr.2024.102310] [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: 11/05/2023] [Revised: 02/21/2024] [Accepted: 04/12/2024] [Indexed: 04/20/2024]
Abstract
Maintaining order at the tissue level is crucial throughout the lifespan, as failure can lead to cancer and an accumulation of molecular and cellular disorders. Perhaps, the most consistent and pervasive result of these failures is aging, which is characterized by the progressive loss of function and decline in the ability to maintain anatomical homeostasis and reproduce. This leads to organ malfunction, diseases, and ultimately death. The traditional understanding of aging is that it is caused by the accumulation of molecular and cellular damage. In this article, we propose a complementary view of aging from the perspective of endogenous bioelectricity which has not yet been integrated into aging research. We propose a view of aging as a morphostasis defect, a loss of biophysical prepattern information, encoding anatomical setpoints used for dynamic tissue and organ homeostasis. We hypothesize that this is specifically driven by abrogation of the endogenous bioelectric signaling that normally harnesses individual cell behaviors toward the creation and upkeep of complex multicellular structures in vivo. Herein, we first describe bioelectricity as the physiological software of life, and then identify and discuss the links between bioelectricity and life extension strategies and age-related diseases. We develop a bridge between aging and regeneration via bioelectric signaling that suggests a research program for healthful longevity via morphoceuticals. Finally, we discuss the broader implications of the homologies between development, aging, cancer and regeneration and how morphoceuticals can be developed for aging.
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Affiliation(s)
- Léo Pio-Lopez
- Allen Discovery Center, Tufts University, Medford, MA 02155, USA
| | - Michael Levin
- Allen Discovery Center, Tufts University, Medford, MA 02155, USA; Wyss Institute for Biologically Inspired Engineering, Boston, MA 02115, USA.
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10
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Balasubramanian S, Weston DA, Levin M, Davidian DCC. Electroceuticals: emerging applications beyond the nervous system and excitable tissues. Trends Pharmacol Sci 2024; 45:391-394. [PMID: 38641490 DOI: 10.1016/j.tips.2024.03.001] [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: 01/11/2024] [Revised: 03/04/2024] [Accepted: 03/04/2024] [Indexed: 04/21/2024]
Abstract
Electroceuticals have evolved beyond devices manipulating neuronal signaling for symptomatic treatment, becoming more precise and disease modulating and expanding beyond the nervous system. These advancements promise transformative applications in arthritis, cancer treatment, tissue regeneration, and more. Here, we discuss these recent advances and offer insights for future research.
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Affiliation(s)
- Swarnalatha Balasubramanian
- Emerging Innovations Unit, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Boston, Massachusetts, USA
| | - David A Weston
- Emerging Innovations Unit, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Michael Levin
- Allen Discovery Center, Tufts University, Medford, MA, USA; Wyss Institute, Harvard University, Boston, MA, USA
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11
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Jiang X, Zhao K, Sun Y, Song X, Yi C, Xiong T, Wang S, Yu Y, Chen X, Liu R, Yan X, Antos CL. The scale of zebrafish pectoral fin buds is determined by intercellular K+ levels and consequent Ca2+-mediated signaling via retinoic acid regulation of Rcan2 and Kcnk5b. PLoS Biol 2024; 22:e3002565. [PMID: 38527087 PMCID: PMC11018282 DOI: 10.1371/journal.pbio.3002565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 04/15/2024] [Accepted: 02/27/2024] [Indexed: 03/27/2024] Open
Abstract
K+ channels regulate morphogens to scale adult fins, but little is known about what regulates the channels and how they control morphogen expression. Using the zebrafish pectoral fin bud as a model for early vertebrate fin/limb development, we found that K+ channels also scale this anatomical structure, and we determined how one K+-leak channel, Kcnk5b, integrates into its developmental program. From FLIM measurements of a Förster Resonance Energy Transfer (FRET)-based K+ sensor, we observed coordinated decreases in intracellular K+ levels during bud growth, and overexpression of K+-leak channels in vivo coordinately increased bud proportions. Retinoic acid, which can enhance fin/limb bud growth, decreased K+ in bud tissues and up-regulated regulator of calcineurin (rcan2). rcan2 overexpression increased bud growth and decreased K+, while CRISPR-Cas9 targeting of rcan2 decreased growth and increased K+. We observed similar results in the adult caudal fins. Moreover, CRISPR targeting of Kcnk5b revealed that Rcan2-mediated growth was dependent on the Kcnk5b. We also found that Kcnk5b enhanced depolarization in fin bud cells via Na+ channels and that this enhanced depolarization was required for Kcnk5b-enhanced growth. Lastly, Kcnk5b-induced shha transcription and bud growth required IP3R-mediated Ca2+ release and CaMKK activity. Thus, we provide a mechanism for how retinoic acid via rcan2 can regulate K+-channel activity to scale a vertebrate appendage via intercellular Ca2+ signaling.
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Affiliation(s)
- Xiaowen Jiang
- School of Life Sciences and Technology, ShanghaiTech University, Shanghai, People’s Republic of China
| | - Kun Zhao
- School of Life Sciences and Technology, ShanghaiTech University, Shanghai, People’s Republic of China
| | - Yi Sun
- School of Life Sciences and Technology, ShanghaiTech University, Shanghai, People’s Republic of China
| | - Xinyue Song
- School of Life Sciences and Technology, ShanghaiTech University, Shanghai, People’s Republic of China
| | - Chao Yi
- School of Life Sciences and Technology, ShanghaiTech University, Shanghai, People’s Republic of China
| | - Tianlong Xiong
- School of Life Sciences and Technology, ShanghaiTech University, Shanghai, People’s Republic of China
| | - Sen Wang
- School of Life Sciences and Technology, ShanghaiTech University, Shanghai, People’s Republic of China
| | - Yi Yu
- School of Life Sciences and Technology, ShanghaiTech University, Shanghai, People’s Republic of China
- Center for Quantitative Biology, Peking University, Beijing, People’s Republic of China
| | - Xiduo Chen
- School of Life Sciences and Technology, ShanghaiTech University, Shanghai, People’s Republic of China
| | - Run Liu
- School of Life Sciences and Technology, ShanghaiTech University, Shanghai, People’s Republic of China
| | - Xin Yan
- School of Life Sciences and Technology, ShanghaiTech University, Shanghai, People’s Republic of China
| | - Christopher L. Antos
- School of Life Sciences and Technology, ShanghaiTech University, Shanghai, People’s Republic of China
- Institut für Pharmakologie und Toxikologie, Technische Universität Dresden, Dresden, Germany
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12
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Tung A, Sperry MM, Clawson W, Pavuluri A, Bulatao S, Yue M, Flores RM, Pai VP, McMillen P, Kuchling F, Levin M. Embryos assist morphogenesis of others through calcium and ATP signaling mechanisms in collective teratogen resistance. Nat Commun 2024; 15:535. [PMID: 38233424 PMCID: PMC10794468 DOI: 10.1038/s41467-023-44522-2] [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: 06/22/2023] [Accepted: 12/17/2023] [Indexed: 01/19/2024] Open
Abstract
Information for organismal patterning can come from a variety of sources. We investigate the possibility that instructive influences for normal embryonic development are provided not only at the level of cells within the embryo, but also via interactions between embryos. To explore this, we challenge groups of embryos with disruptors of normal development while varying group size. Here, we show that Xenopus laevis embryos are much more sensitive to a diverse set of chemical and molecular-biological perturbations when allowed to develop alone or in small groups, than in large groups. Keeping per-embryo exposure constant, we find that increasing the number of exposed embryos in a cohort increases the rate of survival while incidence of defects decreases. This inter-embryo assistance effect is mediated by short-range diffusible signals and involves the P2 ATP receptor. Our data and computational model emphasize that morphogenesis is a collective phenomenon not only at the level of cells, but also of whole bodies, and that cohort size is a crucial variable in studies of ecotoxicology, teratogenesis, and developmental plasticity.
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Affiliation(s)
- Angela Tung
- Allen Discovery Center at Tufts University, Medford, MA, 02155, USA
| | - Megan M Sperry
- Allen Discovery Center at Tufts University, Medford, MA, 02155, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA
| | - Wesley Clawson
- Allen Discovery Center at Tufts University, Medford, MA, 02155, USA
| | - Ananya Pavuluri
- Allen Discovery Center at Tufts University, Medford, MA, 02155, USA
| | - Sydney Bulatao
- Allen Discovery Center at Tufts University, Medford, MA, 02155, USA
| | - Michelle Yue
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA
| | - Ramses Martinez Flores
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA
| | - Vaibhav P Pai
- Allen Discovery Center at Tufts University, Medford, MA, 02155, USA
| | - Patrick McMillen
- Allen Discovery Center at Tufts University, Medford, MA, 02155, USA
| | - Franz Kuchling
- Allen Discovery Center at Tufts University, Medford, MA, 02155, USA
| | - Michael Levin
- Allen Discovery Center at Tufts University, Medford, MA, 02155, USA.
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, 02115, USA.
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13
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McMillen P, Levin M. Optical Estimation of Bioelectric Patterns in Living Embryos. Methods Mol Biol 2024; 2745:91-102. [PMID: 38060181 DOI: 10.1007/978-1-0716-3577-3_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2023]
Abstract
Fluorescent lifetime imaging (FLIM) is a powerful tool for visualizing physiological parameters in vivo. We present here a 3-dye strategy for mapping bioelectric patterns in living Xenopus laevis embryos leveraging the quantitative power of fluorescent lifetime imaging. We discuss a general strategy for disentangling physiological artifacts from true bioelectric signals, a method for dye delivery via transcardial injection, and how to visualize and interpret the fluorescent lifetime of the dyes in vivo.
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Affiliation(s)
- Patrick McMillen
- Department of Biology, Allen Discovery Center, Tufts University, Medford, MA, USA
| | - Michael Levin
- Department of Biology, Allen Discovery Center, Tufts University, Medford, MA, USA.
- Wyss Institute, Harvard University, Cambridge, MA, USA.
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14
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Lukowicz-Bedford RM, Eisen JS, Miller AC. Gap junction mediated bioelectric coordination is required for slow muscle development, organization, and function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.20.572619. [PMID: 38187655 PMCID: PMC10769300 DOI: 10.1101/2023.12.20.572619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Bioelectrical signaling, intercellular communication facilitated by membrane potential and electrochemical coupling, is emerging as a key regulator of animal development. Gap junction (GJ) channels can mediate bioelectric signaling by creating a fast, direct pathway between cells for the movement of ions and other small molecules. In vertebrates, GJ channels are formed by a highly conserved transmembrane protein family called the Connexins. The connexin gene family is large and complex, presenting a challenge in identifying the specific Connexins that create channels within developing and mature tissues. Using the embryonic zebrafish neuromuscular system as a model, we identify a connexin conserved across vertebrate lineages, gjd4, which encodes the Cx46.8 protein, that mediates bioelectric signaling required for appropriate slow muscle development and function. Through a combination of mutant analysis and in vivo imaging we show that gjd4/Cx46.8 creates GJ channels specifically in developing slow muscle cells. Using genetics, pharmacology, and calcium imaging we find that spinal cord generated neural activity is transmitted to developing slow muscle cells and synchronized activity spreads via gjd4/Cx46.8 GJ channels. Finally, we show that bioelectrical signal propagation within the developing neuromuscular system is required for appropriate myofiber organization, and that disruption leads to defects in behavior. Our work reveals the molecular basis for GJ communication among developing muscle cells and reveals how perturbations to bioelectric signaling in the neuromuscular system_may contribute to developmental myopathies. Moreover, this work underscores a critical motif of signal propagation between organ systems and highlights the pivotal role played by GJ communication in coordinating bioelectric signaling during development.
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15
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Manicka S, Pai VP, Levin M. Information integration during bioelectric regulation of morphogenesis of the embryonic frog brain. iScience 2023; 26:108398. [PMID: 38034358 PMCID: PMC10687303 DOI: 10.1016/j.isci.2023.108398] [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: 01/23/2023] [Revised: 07/18/2023] [Accepted: 11/02/2023] [Indexed: 12/02/2023] Open
Abstract
Spatiotemporal patterns of cellular resting potential regulate several aspects of development. One key aspect of the bioelectric code is that transcriptional and morphogenetic states are determined not by local, single-cell, voltage levels but by specific distributions of voltage across cell sheets. We constructed and analyzed a minimal dynamical model of collective gene expression in cells based on inputs of multicellular voltage patterns. Causal integration analysis revealed a higher-order mechanism by which information about the voltage pattern was spatiotemporally integrated into gene activity, as well as a division of labor among and between the bioelectric and genetic components. We tested and confirmed predictions of this model in a system in which bioelectric control of morphogenesis regulates gene expression and organogenesis: the embryonic brain of the frog Xenopus laevis. This study demonstrates that machine learning and computational integration approaches can advance our understanding of the information-processing underlying morphogenetic decision-making, with a potential for other applications in developmental biology and regenerative medicine.
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Affiliation(s)
- Santosh Manicka
- Allen Discovery Center at Tufts University, Medford, MA 02155, USA
| | - Vaibhav P. Pai
- Allen Discovery Center at Tufts University, Medford, MA 02155, USA
| | - Michael Levin
- Allen Discovery Center at Tufts University, Medford, MA 02155, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA
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16
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Abstract
Tissue regeneration is not simply a local repair event occurring in isolation from the distant, uninjured parts of the body. Rather, evidence indicates that regeneration is a whole-animal process involving coordinated interactions between different organ systems. Here, we review recent studies that reveal how remote uninjured tissues and organ systems respond to and engage in regeneration. We also discuss the need for toolkits and technological advancements to uncover and dissect organ communication during regeneration.
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Affiliation(s)
- Fei Sun
- Duke Regeneration Center, Department of Cell Biology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Kenneth D. Poss
- Duke Regeneration Center, Department of Cell Biology, Duke University School of Medicine, Durham, NC 27710, USA
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17
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Matarèse BFE, Rusin A, Seymour C, Mothersill C. Quantum Biology and the Potential Role of Entanglement and Tunneling in Non-Targeted Effects of Ionizing Radiation: A Review and Proposed Model. Int J Mol Sci 2023; 24:16464. [PMID: 38003655 PMCID: PMC10671017 DOI: 10.3390/ijms242216464] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 11/01/2023] [Accepted: 11/13/2023] [Indexed: 11/26/2023] Open
Abstract
It is well established that cells, tissues, and organisms exposed to low doses of ionizing radiation can induce effects in non-irradiated neighbors (non-targeted effects or NTE), but the mechanisms remain unclear. This is especially true of the initial steps leading to the release of signaling molecules contained in exosomes. Voltage-gated ion channels, photon emissions, and calcium fluxes are all involved but the precise sequence of events is not yet known. We identified what may be a quantum entanglement type of effect and this prompted us to consider whether aspects of quantum biology such as tunneling and entanglement may underlie the initial events leading to NTE. We review the field where it may be relevant to ionizing radiation processes. These include NTE, low-dose hyper-radiosensitivity, hormesis, and the adaptive response. Finally, we present a possible quantum biological-based model for NTE.
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Affiliation(s)
- Bruno F. E. Matarèse
- Department of Haematology, University of Cambridge, Cambridge CB2 1TN, UK;
- Department of Physics, University of Cambridge, Cambridge CB2 1TN, UK
| | - Andrej Rusin
- Department of Biology, McMaster University, Hamilton, ON L8S 4L8, Canada; (A.R.); (C.S.)
| | - Colin Seymour
- Department of Biology, McMaster University, Hamilton, ON L8S 4L8, Canada; (A.R.); (C.S.)
| | - Carmel Mothersill
- Department of Biology, McMaster University, Hamilton, ON L8S 4L8, Canada; (A.R.); (C.S.)
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18
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Levin M. Bioelectric networks: the cognitive glue enabling evolutionary scaling from physiology to mind. Anim Cogn 2023; 26:1865-1891. [PMID: 37204591 PMCID: PMC10770221 DOI: 10.1007/s10071-023-01780-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 04/12/2023] [Accepted: 04/24/2023] [Indexed: 05/20/2023]
Abstract
Each of us made the remarkable journey from mere matter to mind: starting life as a quiescent oocyte ("just chemistry and physics"), and slowly, gradually, becoming an adult human with complex metacognitive processes, hopes, and dreams. In addition, even though we feel ourselves to be a unified, single Self, distinct from the emergent dynamics of termite mounds and other swarms, the reality is that all intelligence is collective intelligence: each of us consists of a huge number of cells working together to generate a coherent cognitive being with goals, preferences, and memories that belong to the whole and not to its parts. Basal cognition is the quest to understand how Mind scales-how large numbers of competent subunits can work together to become intelligences that expand the scale of their possible goals. Crucially, the remarkable trick of turning homeostatic, cell-level physiological competencies into large-scale behavioral intelligences is not limited to the electrical dynamics of the brain. Evolution was using bioelectric signaling long before neurons and muscles appeared, to solve the problem of creating and repairing complex bodies. In this Perspective, I review the deep symmetry between the intelligence of developmental morphogenesis and that of classical behavior. I describe the highly conserved mechanisms that enable the collective intelligence of cells to implement regulative embryogenesis, regeneration, and cancer suppression. I sketch the story of an evolutionary pivot that repurposed the algorithms and cellular machinery that enable navigation of morphospace into the behavioral navigation of the 3D world which we so readily recognize as intelligence. Understanding the bioelectric dynamics that underlie construction of complex bodies and brains provides an essential path to understanding the natural evolution, and bioengineered design, of diverse intelligences within and beyond the phylogenetic history of Earth.
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Affiliation(s)
- Michael Levin
- Allen Discovery Center at Tufts University, 200 Boston Ave., Suite 4600, Medford, MA, 02155, USA.
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, MA, USA.
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19
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Petsakou A, Liu Y, Liu Y, Comjean A, Hu Y, Perrimon N. Cholinergic neurons trigger epithelial Ca 2+ currents to heal the gut. Nature 2023; 623:122-131. [PMID: 37722602 PMCID: PMC10699467 DOI: 10.1038/s41586-023-06627-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 09/08/2023] [Indexed: 09/20/2023]
Abstract
A fundamental and unresolved question in regenerative biology is how tissues return to homeostasis after injury. Answering this question is essential for understanding the aetiology of chronic disorders such as inflammatory bowel diseases and cancer1. We used the Drosophila midgut2 to investigate this and discovered that during regeneration a subpopulation of cholinergic3 neurons triggers Ca2+ currents among intestinal epithelial cells, the enterocytes, to promote return to homeostasis. We found that downregulation of the conserved cholinergic enzyme acetylcholinesterase4 in the gut epithelium enables acetylcholine from specific Egr5 (TNF in mammals)-sensing cholinergic neurons to activate nicotinic receptors in innervated enterocytes. This activation triggers high Ca2+, which spreads in the epithelium through Innexin2-Innexin7 gap junctions6, promoting enterocyte maturation followed by reduction of proliferation and inflammation. Disrupting this process causes chronic injury consisting of ion imbalance, Yki (YAP in humans) activation7, cell death and increase of inflammatory cytokines reminiscent of inflammatory bowel diseases8. Altogether, the conserved cholinergic pathway facilitates epithelial Ca2+ currents that heal the intestinal epithelium. Our findings demonstrate nerve- and bioelectric9-dependent intestinal regeneration and advance our current understanding of how a tissue returns to homeostasis after injury.
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Affiliation(s)
| | - Yifang Liu
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Ying Liu
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Aram Comjean
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Yanhui Hu
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Norbert Perrimon
- Department of Genetics, Harvard Medical School, Boston, MA, USA.
- Howard Hughes Medical Institute, Boston, MA, USA.
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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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Roldan L, Montoya C, Solanki V, Cai KQ, Yang M, Correa S, Orrego S. A Novel Injectable Piezoelectric Hydrogel for Periodontal Disease Treatment. ACS APPLIED MATERIALS & INTERFACES 2023; 15:43441-43454. [PMID: 37672788 DOI: 10.1021/acsami.3c08336] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
Periodontal disease is a multifactorial, bacterially induced inflammatory condition characterized by the progressive destruction of periodontal tissues. The successful nonsurgical treatment of periodontitis requires multifunctional technologies offering antibacterial therapies and promotion of bone regeneration simultaneously. For the first time, in this study, an injectable piezoelectric hydrogel (PiezoGEL) was developed after combining gelatin methacryloyl (GelMA) with biocompatible piezoelectric fillers of barium titanate (BTO) that produce electrical charges when stimulated by biomechanical vibrations (e.g., mastication, movements). We harnessed the benefits of hydrogels (injectable, light curable, conforms to pocket spaces, biocompatible) with the bioactive effects of piezoelectric charges. A thorough biomaterial characterization confirmed piezoelectric fillers' successful integration with the hydrogel, photopolymerizability, injectability for clinical use, and electrical charge generation to enable bioactive effects (antibacterial and bone tissue regeneration). PiezoGEL showed significant reductions in pathogenic biofilm biomass (∼41%), metabolic activity (∼75%), and the number of viable cells (∼2-3 log) compared to hydrogels without BTO fillers in vitro. Molecular analysis related the antibacterial effects to be associated with reduced cell adhesion (downregulation of porP and fimA) and increased oxidative stress (upregulation of oxyR) genes. Moreover, PiezoGEL significantly enhanced bone marrow stem cell (BMSC) viability and osteogenic differentiation by upregulating RUNX2, COL1A1, and ALP. In vivo, PiezoGEL effectively reduced periodontal inflammation and increased bone tissue regeneration compared to control groups in a mice model. Findings from this study suggest PiezoGEL to be a promising and novel therapeutic candidate for the treatment of periodontal disease nonsurgically.
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Affiliation(s)
- Lina Roldan
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania 19140, United States
- Bioengineering Research Group (GIB), Universidad EAFIT, Medellín 050037, Colombia
| | - Carolina Montoya
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania 19140, United States
| | - Varun Solanki
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania 19140, United States
| | - Kathy Q Cai
- Histopathology Facility, Fox Chase Cancer, Temple University, Philadelphia, Pennsylvania 19140, United States
| | - Maobin Yang
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania 19140, United States
- Department of Endodontology, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania 19140, United States
| | - Santiago Correa
- Bioengineering Research Group (GIB), Universidad EAFIT, Medellín 050037, Colombia
| | - Santiago Orrego
- Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, Pennsylvania 19140, United States
- Bioengineering Department, College of Engineering, Temple University. Philadelphia, Pennsylvania 19122, United States
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22
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Lagasse E, Levin M. Future medicine: from molecular pathways to the collective intelligence of the body. Trends Mol Med 2023; 29:687-710. [PMID: 37481382 PMCID: PMC10527237 DOI: 10.1016/j.molmed.2023.06.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 06/20/2023] [Accepted: 06/22/2023] [Indexed: 07/24/2023]
Abstract
The remarkable anatomical homeostasis exhibited by complex living organisms suggests that they are inherently reprogrammable information-processing systems that offer numerous interfaces to their physiological and anatomical problem-solving capacities. We briefly review data suggesting that the multiscale competency of living forms affords a new path for biomedicine that exploits the innate collective intelligence of tissues and organs. The concept of tissue-level allostatic goal-directedness is already bearing fruit in clinical practice. We sketch a roadmap towards 'somatic psychiatry' by using advances in bioelectricity and behavioral neuroscience to design methods that induce self-repair of structure and function. Relaxing the assumption that cellular control mechanisms are static, exploiting powerful concepts from cybernetics, behavioral science, and developmental biology may spark definitive solutions to current biomedical challenges.
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Affiliation(s)
- Eric Lagasse
- McGowan Institute for Regenerative Medicine and Department of Pathology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, 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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23
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Podobnik M, Singh AP, Fu Z, Dooley CM, Frohnhöfer HG, Firlej M, Stednitz SJ, Elhabashy H, Weyand S, Weir JR, Lu J, Nüsslein-Volhard C, Irion U. kcnj13 regulates pigment cell shapes in zebrafish and has diverged by cis-regulatory evolution between Danio species. Development 2023; 150:dev201627. [PMID: 37530080 PMCID: PMC10482006 DOI: 10.1242/dev.201627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 07/21/2023] [Indexed: 08/03/2023]
Abstract
Teleost fish of the genus Danio are excellent models to study the genetic and cellular bases of pigment pattern variation in vertebrates. The two sister species Danio rerio and Danio aesculapii show divergent patterns of horizontal stripes and vertical bars that are partly caused by the divergence of the potassium channel gene kcnj13. Here, we show that kcnj13 is required only in melanophores for interactions with xanthophores and iridophores, which cause location-specific pigment cell shapes and thereby influence colour pattern and contrast in D. rerio. Cis-regulatory rather than protein coding changes underlie kcnj13 divergence between the two Danio species. Our results suggest that homotypic and heterotypic interactions between the pigment cells and their shapes diverged between species by quantitative changes in kcnj13 expression during pigment pattern diversification.
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Affiliation(s)
- Marco Podobnik
- Max Planck Institute for Biology, 72076 Tübingen, Germany
| | - Ajeet P. Singh
- Chemical Biology and Therapeutics, Novartis Institutes for BioMedical Research, Cambridge, MA 02139, USA
| | - Zhenqiang Fu
- School of Marine Sciences, Sun Yat-sen University, Zhuhai 519082, China
| | - Christopher M. Dooley
- Department of Genetics, Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | | | - Magdalena Firlej
- Friedrich Miescher Laboratory of the Max Planck Society, 72076 Tübingen, Germany
| | - Sarah J. Stednitz
- Department of Anatomy & Physiology, University of Melbourne, Victoria, 3010, Melbourne, Australia
| | - Hadeer Elhabashy
- Department of Protein Evolution, Max Planck Institute for Biology, 72076 Tübingen, Germany
- Institute for Bioinformatics and Medical Informatics, University of Tübingen, 72076 Tübingen, Germany
- Department of Computer Science, University of Tübingen, 72076 Tübingen, Germany
| | - Simone Weyand
- Department of Biochemistry, University of Cambridge, Cambridge, CB2 1QW, UK
| | - John R. Weir
- Friedrich Miescher Laboratory of the Max Planck Society, 72076 Tübingen, Germany
| | - Jianguo Lu
- School of Marine Sciences, Sun Yat-sen University, Zhuhai 519082, China
| | | | - Uwe Irion
- Max Planck Institute for Biology, 72076 Tübingen, Germany
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24
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Petsakou A, Liu Y, Liu Y, Comjean A, Hu Y, Perrimon N. Epithelial Ca 2+ waves triggered by enteric neurons heal the gut. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.14.553227. [PMID: 37645990 PMCID: PMC10461974 DOI: 10.1101/2023.08.14.553227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
A fundamental and unresolved question in regenerative biology is how tissues return to homeostasis after injury. Answering this question is essential for understanding the etiology of chronic disorders such as inflammatory bowel diseases and cancer. We used the Drosophila midgut to investigate this question and discovered that during regeneration a subpopulation of cholinergic enteric neurons triggers Ca2+ currents among enterocytes to promote return of the epithelium to homeostasis. Specifically, we found that down-regulation of the cholinergic enzyme Acetylcholinesterase in the epithelium enables acetylcholine from defined enteric neurons, referred as ARCENs, to activate nicotinic receptors in enterocytes found near ARCEN-innervations. This activation triggers high Ca2+ influx that spreads in the epithelium through Inx2/Inx7 gap junctions promoting enterocyte maturation followed by reduction of proliferation and inflammation. Disrupting this process causes chronic injury consisting of ion imbalance, Yki activation and increase of inflammatory cytokines together with hyperplasia, reminiscent of inflammatory bowel diseases. Altogether, we found that during gut regeneration the conserved cholinergic pathway facilitates epithelial Ca2+ waves that heal the intestinal epithelium. Our findings demonstrate nerve- and bioelectric-dependent intestinal regeneration which advance the current understanding of how a tissue returns to its homeostatic state after injury and could ultimately help existing therapeutics.
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Affiliation(s)
| | - Yifang Liu
- Department of Genetics, Harvard Medical School, Boston, USA
| | - Ying Liu
- Department of Genetics, Harvard Medical School, Boston, USA
| | - Aram Comjean
- Department of Genetics, Harvard Medical School, Boston, USA
| | - Yanhui Hu
- Department of Genetics, Harvard Medical School, Boston, USA
| | - Norbert Perrimon
- Department of Genetics, Harvard Medical School, Boston, USA
- Howard Hughes Medical Institute, Boston, USA
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25
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Pio-Lopez L, Bischof J, LaPalme JV, Levin M. The scaling of goals from cellular to anatomical homeostasis: an evolutionary simulation, experiment and analysis. Interface Focus 2023; 13:20220072. [PMID: 37065270 PMCID: PMC10102734 DOI: 10.1098/rsfs.2022.0072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 03/02/2023] [Indexed: 04/18/2023] Open
Abstract
Complex living agents consist of cells, which are themselves competent sub-agents navigating physiological and metabolic spaces. Behaviour science, evolutionary developmental biology and the field of machine intelligence all seek to understand the scaling of biological cognition: what enables individual cells to integrate their activities to result in the emergence of a novel, higher-level intelligence with large-scale goals and competencies that belong to it and not to its parts? Here, we report the results of simulations based on the TAME framework, which proposes that evolution pivoted the collective intelligence of cells during morphogenesis of the body into traditional behavioural intelligence by scaling up homeostatic competencies of cells in metabolic space. In this article, we created a minimal in silico system (two-dimensional neural cellular automata) and tested the hypothesis that evolutionary dynamics are sufficient for low-level setpoints of metabolic homeostasis in individual cells to scale up to tissue-level emergent behaviour. Our system showed the evolution of the much more complex setpoints of cell collectives (tissues) that solve a problem in morphospace: the organization of a body-wide positional information axis (the classic French flag problem in developmental biology). We found that these emergent morphogenetic agents exhibit a number of predicted features, including the use of stress propagation dynamics to achieve the target morphology as well as the ability to recover from perturbation (robustness) and long-term stability (even though neither of these was directly selected for). Moreover, we observed an unexpected behaviour of sudden remodelling long after the system stabilizes. We tested this prediction in a biological system-regenerating planaria-and observed a very similar phenomenon. We propose that this system is a first step towards a quantitative understanding of how evolution scales minimal goal-directed behaviour (homeostatic loops) into higher-level problem-solving agents in morphogenetic and other spaces.
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Affiliation(s)
- Léo Pio-Lopez
- 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 02115, USA
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26
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Harper M, Hu Y, Donahue J, Acosta B, Dievenich Braes F, Nguyen S, Zeng J, Barbaro J, Lee H, Bui H, McMenamin SK. Thyroid hormone regulates proximodistal patterning in fin rays. Proc Natl Acad Sci U S A 2023; 120:e2219770120. [PMID: 37186843 PMCID: PMC10214145 DOI: 10.1073/pnas.2219770120] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 03/26/2023] [Indexed: 05/17/2023] Open
Abstract
Processes that regulate size and patterning along an axis must be highly integrated to generate robust shapes; relative changes in these processes underlie both congenital disease and evolutionary change. Fin length mutants in zebrafish have provided considerable insight into the pathways regulating fin size, yet signals underlying patterning have remained less clear. The bony rays of the fins possess distinct patterning along the proximodistal axis, reflected in the location of ray bifurcations and the lengths of ray segments, which show progressive shortening along the axis. Here, we show that thyroid hormone (TH) regulates aspects of proximodistal patterning of the caudal fin rays, regardless of fin size. TH promotes distal gene expression patterns, coordinating ray bifurcations and segment shortening with skeletal outgrowth along the proximodistal axis. This distalizing role for TH is conserved between development and regeneration, in all fins (paired and medial), and between Danio species as well as distantly related medaka. During regenerative outgrowth, TH acutely induces Shh-mediated skeletal bifurcation. Zebrafish have multiple nuclear TH receptors, and we found that unliganded Thrab-but not Thraa or Thrb-inhibits the formation of distal features. Broadly, these results demonstrate that proximodistal morphology is regulated independently from size-instructive signals. Modulating proximodistal patterning relative to size-either through changes to TH metabolism or other hormone-independent pathways-can shift skeletal patterning in ways that recapitulate aspects of fin ray diversity found in nature.
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Affiliation(s)
- Melody Harper
- Biology Department, Morrissey College of Arts and Sciences, Boston College, Chestnut Hill, MA02467
| | - Yinan Hu
- Biology Department, Morrissey College of Arts and Sciences, Boston College, Chestnut Hill, MA02467
| | - Joan Donahue
- Biology Department, Morrissey College of Arts and Sciences, Boston College, Chestnut Hill, MA02467
| | - Benjamin Acosta
- Biology Department, Morrissey College of Arts and Sciences, Boston College, Chestnut Hill, MA02467
| | - Flora Dievenich Braes
- Biology Department, Morrissey College of Arts and Sciences, Boston College, Chestnut Hill, MA02467
| | - Stacy Nguyen
- Biology Department, Morrissey College of Arts and Sciences, Boston College, Chestnut Hill, MA02467
| | - Jenny Zeng
- Biology Department, Morrissey College of Arts and Sciences, Boston College, Chestnut Hill, MA02467
| | - Julianna Barbaro
- Biology Department, Morrissey College of Arts and Sciences, Boston College, Chestnut Hill, MA02467
| | - Hyungwoo Lee
- Biology Department, Morrissey College of Arts and Sciences, Boston College, Chestnut Hill, MA02467
| | - Hoa Bui
- Biology Department, Morrissey College of Arts and Sciences, Boston College, Chestnut Hill, MA02467
| | - Sarah K. McMenamin
- Biology Department, Morrissey College of Arts and Sciences, Boston College, Chestnut Hill, MA02467
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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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Miller WB. A scale-free universal relational information matrix (N-space) reconciles the information problem: N-space as the fabric of reality. Commun Integr Biol 2023; 16:2193006. [PMID: 37188326 PMCID: PMC10177686 DOI: 10.1080/19420889.2023.2193006] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 03/14/2023] [Accepted: 03/15/2023] [Indexed: 05/17/2023] Open
Abstract
Cellular measurement is a crucial faculty in living systems, and exaptations are acknowledged as a significant source of evolutionary innovation. However, the possibility that the origin of biological order is predicated on an exaptation of the measurement of information from the abiotic realm has not been previously explored. To support this hypothesis, the existence of a universal holographic relational information space-time matrix is proposed as a scale-free unification of abiotic and biotic information systems. In this framework, information is a universal property representing the interactions between matter and energy that can be subject to observation. Since observers are also universally distributed, information can be deemed the fundamental fabric of the universe. The novel concept of compartmentalizing this universal N-space information matrix into separate N-space partitions as nodes of informational density defined by Markov blankets and boundaries is introduced, permitting their applicability to both abiotic and biotic systems. Based on these N-space partitions, abiotic systems can derive meaningful information from the conditional settlement of quantum entanglement asymmetries and coherences between separately bounded quantum informational reference frames sufficient to be construed as a form of measurement. These conditional relationships are the precursor of the reiterating nested architecture of the N-space-derived information fields that characterize life and account for biological order. Accordingly, biotic measurement and biological N-space partitioning are exaptations of preexisting information processes within abiotic systems. Abiotic and biotic states thereby reconcile as differing forms of measurement of fundamental universal information. The essential difference between abiotic and biotic states lies within the attributes of the specific observer/detectors, thereby clarifying several contentious aspects of self-referential consciousness.
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29
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Silic MR, Zhang G. Bioelectricity in Developmental Patterning and Size Control: Evidence and Genetically Encoded Tools in the Zebrafish Model. Cells 2023; 12:cells12081148. [PMID: 37190057 DOI: 10.3390/cells12081148] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Revised: 04/03/2023] [Accepted: 04/10/2023] [Indexed: 05/17/2023] Open
Abstract
Developmental patterning is essential for regulating cellular events such as axial patterning, segmentation, tissue formation, and organ size determination during embryogenesis. Understanding the patterning mechanisms remains a central challenge and fundamental interest in developmental biology. Ion-channel-regulated bioelectric signals have emerged as a player of the patterning mechanism, which may interact with morphogens. Evidence from multiple model organisms reveals the roles of bioelectricity in embryonic development, regeneration, and cancers. The Zebrafish model is the second most used vertebrate model, next to the mouse model. The zebrafish model has great potential for elucidating the functions of bioelectricity due to many advantages such as external development, transparent early embryogenesis, and tractable genetics. Here, we review genetic evidence from zebrafish mutants with fin-size and pigment changes related to ion channels and bioelectricity. In addition, we review the cell membrane voltage reporting and chemogenetic tools that have already been used or have great potential to be implemented in zebrafish models. Finally, new perspectives and opportunities for bioelectricity research with zebrafish are discussed.
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Affiliation(s)
- Martin R Silic
- Department of Comparative Pathobiology, Purdue University, West Lafayette, IN 47907, USA
| | - GuangJun Zhang
- Department of Comparative Pathobiology, Purdue University, West Lafayette, IN 47907, USA
- Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
- Purdue Institute for Inflammation, Immunology and Infectious Diseases (PI4D), Purdue University, West Lafayette, IN 47907, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, 625 Harrison Street, West Lafayette, IN 47907, USA
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30
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Pio-Lopez L, Levin M. Morphoceuticals: perspectives for discovery of drugs targeting anatomical control mechanisms in regenerative medicine, cancer and aging. Drug Discov Today 2023; 28:103585. [PMID: 37059328 DOI: 10.1016/j.drudis.2023.103585] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 03/18/2023] [Accepted: 04/06/2023] [Indexed: 04/16/2023]
Abstract
Morphoceuticals are a new class of interventions that target the setpoints of anatomical homeostasis for efficient, modular control of growth and form. Here, we focus on a subclass: electroceuticals, which specifically target the cellular bioelectrical interface. Cellular collectives in all tissues form bioelectrical networks via ion channels and gap junctions that process morphogenetic information, controlling gene expression and allowing cell networks to adaptively and dynamically control growth and pattern formation. Recent progress in understanding this physiological control system, including predictive computational models, suggests that targeting bioelectrical interfaces can control embryogenesis and maintain shape against injury, senescence and tumorigenesis. We propose a roadmap for drug discovery focused on manipulating endogenous bioelectric signaling for regenerative medicine, cancer suppression and antiaging therapeutics. Teaser: By taking advantage of the native problem-solving competencies of cells and tissues, a new kind of top-down approach to biomedicine becomes possible. Bioelectricity offers an especially tractable interface for interventions targeting the software of life for regenerative medicine applications.
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Affiliation(s)
- Léo Pio-Lopez
- 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, 02115, USA.
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31
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Bongard J, Levin M. There's Plenty of Room Right Here: Biological Systems as Evolved, Overloaded, Multi-Scale Machines. Biomimetics (Basel) 2023; 8:110. [PMID: 36975340 PMCID: PMC10046700 DOI: 10.3390/biomimetics8010110] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 02/24/2023] [Accepted: 03/01/2023] [Indexed: 03/18/2023] Open
Abstract
The applicability of computational models to the biological world is an active topic of debate. We argue that a useful path forward results from abandoning hard boundaries between categories and adopting an observer-dependent, pragmatic view. Such a view dissolves the contingent dichotomies driven by human cognitive biases (e.g., a tendency to oversimplify) and prior technological limitations in favor of a more continuous view, necessitated by the study of evolution, developmental biology, and intelligent machines. Form and function are tightly entwined in nature, and in some cases, in robotics as well. Thus, efforts to re-shape living systems for biomedical or bioengineering purposes require prediction and control of their function at multiple scales. This is challenging for many reasons, one of which is that living systems perform multiple functions in the same place at the same time. We refer to this as "polycomputing"-the ability of the same substrate to simultaneously compute different things, and make those computational results available to different observers. This ability is an important way in which living things are a kind of computer, but not the familiar, linear, deterministic kind; rather, living things are computers in the broad sense of their computational materials, as reported in the rapidly growing physical computing literature. We argue that an observer-centered framework for the computations performed by evolved and designed systems will improve the understanding of mesoscale events, as it has already done at quantum and relativistic scales. To develop our understanding of how life performs polycomputing, and how it can be convinced to alter one or more of those functions, we can first create technologies that polycompute and learn how to alter their functions. Here, we review examples of biological and technological polycomputing, and develop the idea that the overloading of different functions on the same hardware is an important design principle that helps to understand and build both evolved and designed systems. Learning to hack existing polycomputing substrates, as well as to evolve and design new ones, will have massive impacts on regenerative medicine, robotics, and computer engineering.
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Affiliation(s)
- Joshua Bongard
- Department of Computer Science, University of Vermont, Burlington, VT 05405, USA
| | - Michael Levin
- Allen Discovery Center at Tufts University, 200 Boston Ave., Suite 4600, Medford, MA 02155, USA
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Li C, Zhang S, Yao Y, Wang Y, Xiao C, Yang B, Huang J, Li W, Ning C, Zhai J, Yu P, Wang Y. Piezoelectric Bioactive Glasses Composite Promotes Angiogenesis by the Synergistic Effect of Wireless Electrical Stimulation and Active Ions. Adv Healthc Mater 2023:e2300064. [PMID: 36854114 DOI: 10.1002/adhm.202300064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 02/09/2023] [Indexed: 03/02/2023]
Abstract
Insufficient angiogenesis frequently occurs after the implantation of orthopedic materials, which greatly increases the risk of bone defect reconstruction failure. Therefore, the development of bone implant with improved angiogenic properties is of great importance. Mimicking the extracellular matrix clues provides a more direct and effective strategy to modulate angiogenesis. Herein, inspired by the bioelectrical characteristics of the bone microenvironment, a piezoelectric bioactive glasses composite (P-KNN/BG) based on the incorporation of polarized potassium sodium niobate is constructed, which could effectively promote angiogenesis. It is found that P-KNN/BG has exceptional wireless electrical stimulation performance and sustained active ions release. In vitro cell experiments reveal that P-KNN/BG enhances endothelial cell adhesion, migration, and differentiation via activating the eNOS/NO signaling pathway, which might be contributed to cell membrane hyperpolarization induced by wireless electrical stimulation increase the influx of active ions into the cells. In vivo chick chorioallantoic membrane experiment demonstrates that P-KNN/BG shows excellent pro-angiogenic capacity and biocompatibility. This work broadens the current understanding of bioactive materials with bionic electrical properties, which brings new insights into the clinical treatment of bone defect repair.
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Affiliation(s)
- Changhao Li
- Hospital of Stomatology, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, 510055, China.,School of Material Science and Engineering, National Engineering Research Center for Tissue Restoration and Reconstruction, Metallic Materials Surface Functionalization Engineering Research Center of Guangdong Province, South China University of Technology, Guangzhou, 510641, China
| | - Siyu Zhang
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China
| | - Yichen Yao
- Hospital of Stomatology, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, 510055, China
| | - Yanlan Wang
- Hospital of Stomatology, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, 510055, China
| | - Cairong Xiao
- School of Material Science and Engineering, National Engineering Research Center for Tissue Restoration and Reconstruction, Metallic Materials Surface Functionalization Engineering Research Center of Guangdong Province, South China University of Technology, Guangzhou, 510641, China
| | - Bo Yang
- Hospital of Stomatology, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, 510055, China
| | - Jingyan Huang
- Hospital of Stomatology, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, 510055, China
| | - Weichang Li
- Hospital of Stomatology, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, 510055, China
| | - Chengyun Ning
- School of Material Science and Engineering, National Engineering Research Center for Tissue Restoration and Reconstruction, Metallic Materials Surface Functionalization Engineering Research Center of Guangdong Province, South China University of Technology, Guangzhou, 510641, China
| | - Jinxia Zhai
- School of Material Science and Engineering, National Engineering Research Center for Tissue Restoration and Reconstruction, Metallic Materials Surface Functionalization Engineering Research Center of Guangdong Province, South China University of Technology, Guangzhou, 510641, China
| | - Peng Yu
- School of Material Science and Engineering, National Engineering Research Center for Tissue Restoration and Reconstruction, Metallic Materials Surface Functionalization Engineering Research Center of Guangdong Province, South China University of Technology, Guangzhou, 510641, China
| | - Yan Wang
- Hospital of Stomatology, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, 510055, China
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Cervera J, Manzanares JA, Levin M, Mafe S. Transplantation of fragments from different planaria: A bioelectrical model for head regeneration. J Theor Biol 2023; 558:111356. [PMID: 36403806 DOI: 10.1016/j.jtbi.2022.111356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 10/16/2022] [Accepted: 11/11/2022] [Indexed: 11/18/2022]
Abstract
Head-tail planaria morphologies are influenced by the electric potential differences across the animal's primary axis, as evidenced e.g. by voltage-sensitive dyes and functional experiments that create permanent lines of 2-headed but genetically wild-type animals. However, bioelectrical and biochemical models that make predictions on what would happen in the case of spatial chimeras made by tissue transplantation from different planaria (different species and head shapes) are lacking. Here, we use a bioelectrical model to qualitatively describe the effects of tissue transplantation on the shape of the regenerated head. To this end, we assume that the cells may have distinct sets of ion channels and ascribe the system outcome to the axial distributions of average cell potentials over morphologically relevant regions. Our rationale is that the distributions of signaling ions and molecules are spatially coupled with multicellular electric potentials. Thus, long-time downstream transcriptional events should be triggered by short-time bioelectrical processes. We show that relatively small differences between the ion channel characteristics of the cells could eventually give noticeable changes in the electric potential profiles and the expected morphological deviations, which suggests that small but timely bioelectrical actions may have significant morphological effects. Our approach is based on the observed relationships between bioelectrical regionalization and biochemical gradients in body-plan studies. Such models are relevant to regenerative, developmental, and cancer biology in which cells with distinct properties and morphogenetic target states confront each other in the same tissue.
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Affiliation(s)
- Javier Cervera
- Dept. Termodinàmica, Facultat de Física, Universitat de València, E-46100 Burjassot, Spain.
| | - José A Manzanares
- 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, MA 02155-4243, 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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34
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Shreesha L, Levin M. Cellular Competency during Development Alters Evolutionary Dynamics in an Artificial Embryogeny Model. ENTROPY (BASEL, SWITZERLAND) 2023; 25:e25010131. [PMID: 36673272 PMCID: PMC9858125 DOI: 10.3390/e25010131] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 12/23/2022] [Accepted: 12/29/2022] [Indexed: 05/25/2023]
Abstract
Biological genotypes do not code directly for phenotypes; developmental physiology is the control layer that separates genomes from capacities ascertained by selection. A key aspect is cellular competency, since cells are not passive materials but descendants of unicellular organisms with complex context-sensitive behavioral capabilities. To probe the effects of different degrees of cellular competency on evolutionary dynamics, we used an evolutionary simulation in the context of minimal artificial embryogeny. Virtual embryos consisted of a single axis of positional information values provided by cells' 'structural genes', operated upon by an evolutionary cycle in which embryos' fitness was proportional to monotonicity of the axial gradient. Evolutionary dynamics were evaluated in two modes: hardwired development (genotype directly encodes phenotype), and a more realistic mode in which cells interact prior to evaluation by the fitness function ("regulative" development). We find that even minimal ability of cells with to improve their position in the embryo results in better performance of the evolutionary search. Crucially, we observed that increasing the behavioral competency masks the raw fitness encoded by structural genes, with selection favoring improvements to its developmental problem-solving capacities over improvements to its structural genome. This suggests the existence of a powerful ratchet mechanism: evolution progressively becomes locked in to improvements in the intelligence of its agential substrate, with reduced pressure on the structural genome. This kind of feedback loop in which evolution increasingly puts more effort into the developmental software than perfecting the hardware explains the very puzzling divergence of genome from anatomy in species like planaria. In addition, it identifies a possible driver for scaling intelligence over evolutionary time, and suggests strategies for engineering novel systems in silico and in bioengineering.
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Affiliation(s)
- Lakshwin Shreesha
- UFR Fundamental and Biomedical Sciences, Université Paris Cité, 75006 Paris, France
| | - Michael Levin
- Allen Discovery Center, Tufts University, Medford, MA 02155, USA
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35
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Funk RHW, Scholkmann F. The significance of bioelectricity on all levels of organization of an organism. Part 1: From the subcellular level to cells. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2023; 177:185-201. [PMID: 36481271 DOI: 10.1016/j.pbiomolbio.2022.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 11/24/2022] [Accepted: 12/03/2022] [Indexed: 12/12/2022]
Abstract
Bioelectricity plays an essential role in the structural and functional organization of biological organisms. In this first article of our three-part series, we summarize the importance of bioelectricity for the basic structural level of biological organization, i.e. from the subcellular level (charges, ion channels, molecules and cell organelles) to cells.
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Affiliation(s)
- Richard H W Funk
- Institute of Anatomy, Center for Theoretical Medicine, TU-Dresden, 01307, Dresden, Germany; Dresden International University, 01067, Dresden, Germany.
| | - Felix Scholkmann
- Biomedical Optics Research Laboratory, Department of Neonatology, University Hospital Zurich, University of Zurich, 8091, Zurich, Switzerland.
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36
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Abstract
The Turing model (or reaction-diffusion model), first published in 1952, is a mathematical model that can account for autonomy in the morphogenesis of organisms. Although initially controversial, the model has gradually gained wider acceptance among experimental embryologists due to the accumulation of experimental data to support it. More recently, this model and others based on it have been used not only to explain biological phenomena conceptually but also as working hypotheses for molecular-level experiments and as internal components of more-complex 3D models. In this Spotlight, I will provide a personal perspective from an experimental biologist on some of the recent developments of the Turing model.
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Affiliation(s)
- Shigeru Kondo
- Osaka University, Faculty of Frontia Bioscience, Osaka 565-0871, Japan
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37
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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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38
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Pio-Lopez L, Kuchling F, Tung A, Pezzulo G, Levin M. Active inference, morphogenesis, and computational psychiatry. Front Comput Neurosci 2022; 16:988977. [PMID: 36507307 PMCID: PMC9731232 DOI: 10.3389/fncom.2022.988977] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 10/17/2022] [Indexed: 11/26/2022] Open
Abstract
Active inference is a leading theory in neuroscience that provides a simple and neuro-biologically plausible account of how action and perception are coupled in producing (Bayes) optimal behavior; and has been recently used to explain a variety of psychopathological conditions. In parallel, morphogenesis has been described as the behavior of a (non-neural) cellular collective intelligence solving problems in anatomical morphospace. In this article, we establish a link between the domains of cell biology and neuroscience, by analyzing disorders of morphogenesis as disorders of (active) inference. The aim of this article is three-fold. We want to: (i) reveal a connection between disorders of morphogenesis and disorders of active inference as apparent in psychopathological conditions; (ii) show how disorders of morphogenesis can be simulated using active inference; (iii) suggest that active inference can shed light on developmental defects or aberrant morphogenetic processes, seen as disorders of information processing, and perhaps suggesting novel intervention and repair strategies. We present four simulations illustrating application of these ideas to cellular behavior during morphogenesis. Three of the simulations show that the same forms of aberrant active inference (e.g., deficits of sensory attenuation and low sensory precision) that have been used to explain psychopathological conditions (e.g., schizophrenia and autism) also produce familiar disorders of development and morphogenesis when implemented at the level of the collective behavior of a group of cells. The fourth simulation involves two cells with too high precision, in which we show that the reduction of concentration signaling and sensitivity to the signals of other cells treats the development defect. Finally, we present the results of an experimental test of one of the model's predictions in early Xenopus laevis embryos: thioridazine (a dopamine antagonist that may reduce sensory precision in biological systems) induced developmental (anatomical) defects as predicted. The use of conceptual and empirical tools from neuroscience to understand the morphogenetic behavior of pre-neural agents offers the possibility of new approaches in regenerative medicine and evolutionary developmental biology.
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Affiliation(s)
- Léo Pio-Lopez
- Allen Discovery Center, Tufts University, Medford, MA, United States
| | - Franz Kuchling
- Allen Discovery Center, Tufts University, Medford, MA, United States
| | - Angela Tung
- Allen Discovery Center, Tufts University, Medford, MA, United States
| | - Giovanni Pezzulo
- Institute of Cognitive Sciences and Technologies, National Research Council, Rome, Italy
| | - Michael Levin
- Allen Discovery Center, Tufts University, Medford, MA, United States
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, United States
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39
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Zebrafish Embryos Display Characteristic Bioelectric Signals during Early Development. Cells 2022; 11:cells11223586. [PMID: 36429015 PMCID: PMC9688842 DOI: 10.3390/cells11223586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/08/2022] [Accepted: 11/10/2022] [Indexed: 11/16/2022] Open
Abstract
Bioelectricity is defined as endogenous electrical signaling mediated by the dynamic distribution of charged molecules. Recently, increasing evidence has revealed that cellular bioelectric signaling is critical for regulating embryonic development, regeneration, and congenital diseases. However, systematic real-time in vivo dynamic electrical activity monitoring of whole organisms has been limited, mainly due to the lack of a suitable model system and voltage measurement tools for in vivo biology. Here, we addressed this gap by utilizing a genetically stable zebrafish line, Tg (ubiquitin: ASAP1), and ASAP1 (Accelerated sensor of action potentials 1), a genetically encoded voltage indicator (GEVI). With light-sheet microscopy, we systematically investigated cell membrane potential (Vm) signals during different embryonic stages. We found cells of zebrafish embryos showed local membrane hyperpolarization at the cleavage furrows during the cleavage period of embryogenesis. This signal appeared before cytokinesis and fluctuated as it progressed. In contrast, whole-cell transient hyperpolarization was observed during the blastula and gastrula stages. These signals were generally limited to the superficial blastomere, but they could be detected within the deeper cells during the gastrulation period. Moreover, the zebrafish embryos exhibit tissue-level cell Vm signals during the segmentation period. Middle-aged somites had strong and dynamic Vm fluctuations starting at about the 12-somite stage. These embryonic stage-specific characteristic cellular bioelectric signals suggest that they might play a diverse role in zebrafish embryogenesis that could underlie human congenital diseases.
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40
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Bioelectric regulation of intestinal stem cells. Trends Cell Biol 2022:S0962-8924(22)00234-3. [PMID: 36396487 PMCID: PMC10183058 DOI: 10.1016/j.tcb.2022.10.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 10/21/2022] [Accepted: 10/24/2022] [Indexed: 11/17/2022]
Abstract
Proper regulation of ion balance across the intestinal epithelium is essential for physiological functions, while ion imbalance causes intestinal disorders with dire health consequences. Ion channels, pumps, and exchangers are vital for regulating ion movements (i.e., bioelectric currents) that control epithelial absorption and secretion. Recent in vivo studies used the Drosophila gut to identify conserved pathways that link regulators of Ca2+, Na+ and Cl- with intestinal stem cell (ISC) proliferation. These studies laid a foundation for using the Drosophila gut to identify conserved proliferative responses triggered by bioelectric regulators. Here, we review these studies, discuss their significance, as well as the advantages of using Drosophila to unravel conserved bioelectrically induced molecular pathways in the intestinal epithelium under physiological, pathophysiological, and regenerative conditions.
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Zhu J, Patel R, Trofka A, Harfe BD, Mackem S. Sonic hedgehog is not a limb morphogen but acts as a trigger to specify all digits in mice. Dev Cell 2022; 57:2048-2062.e4. [PMID: 35977544 PMCID: PMC9709693 DOI: 10.1016/j.devcel.2022.07.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 06/03/2022] [Accepted: 07/26/2022] [Indexed: 11/03/2022]
Abstract
Limb patterning by Sonic hedgehog (Shh), via either graded spatial or temporal signal integration, is a paradigm for "morphogen" function, yet how Shh instructs distinct digit identities remains controversial. Here, we bypass the Shh requirement in cell survival during outgrowth and demonstrate that a transient, early Shh pulse is both necessary and sufficient for normal mouse limb development. Shh response is only short range and is limited to the Shh-expressing zone during this time window. Shh patterns digits 1-3, anterior to this zone, by an indirect mechanism rather than direct spatial or temporal signal integration. Using a genetic relay-signaling assay, we discover that Shh also specifies digit 1/thumb (thought to be exclusively Shh independent) indirectly, and this finding implicates Shh in a unique regulatory hierarchy for digit 1 evolutionary adaptations such as opposable thumbs. This study illuminates Shh as a trigger for an indirect downstream network that becomes rapidly self-sustaining, with mechanistic relevance for limb development, regeneration, and evolution.
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Affiliation(s)
- Jianjian Zhu
- Cancer and Developmental Biology Laboratory, Center for Cancer Research, NCI, Frederick, MD, USA
| | - Rashmi Patel
- Cancer and Developmental Biology Laboratory, Center for Cancer Research, NCI, Frederick, MD, USA
| | - Anna Trofka
- Cancer and Developmental Biology Laboratory, Center for Cancer Research, NCI, Frederick, MD, USA
| | - Brian D Harfe
- College of Medicine, Department of Molecular Genetics and Microbiology and the Genetics Institute, University of Florida, Gainesville, FL, USA
| | - Susan Mackem
- Cancer and Developmental Biology Laboratory, Center for Cancer Research, NCI, Frederick, MD, USA.
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42
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Pai VP, Cooper BG, Levin M. Screening Biophysical Sensors and Neurite Outgrowth Actuators in Human Induced-Pluripotent-Stem-Cell-Derived Neurons. Cells 2022; 11:cells11162470. [PMID: 36010547 PMCID: PMC9406775 DOI: 10.3390/cells11162470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 07/26/2022] [Accepted: 08/04/2022] [Indexed: 11/16/2022] Open
Abstract
All living cells maintain a charge distribution across their cell membrane (membrane potential) by carefully controlled ion fluxes. These bioelectric signals regulate cell behavior (such as migration, proliferation, differentiation) as well as higher-level tissue and organ patterning. Thus, voltage gradients represent an important parameter for diagnostics as well as a promising target for therapeutic interventions in birth defects, injury, and cancer. However, despite much progress in cell and molecular biology, little is known about bioelectric states in human stem cells. Here, we present simple methods to simultaneously track ion dynamics, membrane voltage, cell morphology, and cell activity (pH and ROS), using fluorescent reporter dyes in living human neurons derived from induced neural stem cells (hiNSC). We developed and tested functional protocols for manipulating ion fluxes, membrane potential, and cell activity, and tracking neural responses to injury and reinnervation in vitro. Finally, using morphology sensor, we tested and quantified the ability of physiological actuators (neurotransmitters and pH) to manipulate nerve repair and reinnervation. These methods are not specific to a particular cell type and should be broadly applicable to the study of bioelectrical controls across a wide range of combinations of models and endpoints.
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Affiliation(s)
- Vaibhav P. Pai
- Allen Discovery Center at Tufts University, Medford, MA 02155, USA
| | - Ben G. Cooper
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - Michael Levin
- Allen Discovery Center at Tufts University, Medford, MA 02155, USA
- Correspondence:
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43
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Fields C, Glazebrook JF, Levin M. Neurons as hierarchies of quantum reference frames. Biosystems 2022; 219:104714. [PMID: 35671840 DOI: 10.1016/j.biosystems.2022.104714] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 05/28/2022] [Accepted: 05/28/2022] [Indexed: 11/19/2022]
Abstract
Conceptual and mathematical models of neurons have lagged behind empirical understanding for decades. Here we extend previous work in modeling biological systems with fully scale-independent quantum information-theoretic tools to develop a uniform, scalable representation of synapses, dendritic and axonal processes, neurons, and local networks of neurons. In this representation, hierarchies of quantum reference frames act as hierarchical active-inference systems. The resulting model enables specific predictions of correlations between synaptic activity, dendritic remodeling, and trophic reward. We summarize how the model may be generalized to nonneural cells and tissues in developmental and regenerative contexts.
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Affiliation(s)
- Chris Fields
- 23 Rue des Lavandières, 11160 Caunes Minervois, France.
| | - James F Glazebrook
- Department of Mathematics and Computer Science, Eastern Illinois University, Charleston, IL 61920, USA; Adjunct Faculty, Department of Mathematics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Michael Levin
- Allen Discovery Center at Tufts University, Medford, MA 02155, USA
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44
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Pai VP, Levin M. HCN2 Channel-induced Rescue of Brain, Eye, Heart, and Gut Teratogenesis Caused by Nicotine, Ethanol, and Aberrant Notch Signaling. Wound Repair Regen 2022; 30:681-706. [PMID: 35662339 DOI: 10.1111/wrr.13032] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 04/28/2022] [Accepted: 05/19/2022] [Indexed: 11/30/2022]
Abstract
Organogenesis is a complex process that can be disrupted by embryonic exposure to teratogens or mutation-induced alterations in signaling pathways, both of which result in organ mispatterning. Building on prior work in Xenopus laevis that showed that increased HCN2 ion channel activity rescues nicotine-induced brain & eye morphogenesis, we demonstrate much broader HCN2-based rescue of organ patterning defects. Induced HCN2 expression in both local or distant tissues can rescue CNS (brain & eye) as well as non-CNS (heart, & gut) organ defects induced by three different teratogenic conditions: nicotine exposure, ethanol exposure, or aberrant Notch protein. Rescue can also be induced by small-molecule HCN2 channel activators, even with delayed treatment initiation. Our results suggest that HCN2 (likely mediated by bioelectric signals) can be an effective regulator of organogenesis from all three germ layers (ectoderm, mesoderm, and endoderm) and reveal non-cell-autonomous influences on organ formation that work at considerable distance during embryonic development. These results suggest molecular bioelectric strategies for repair that could be explored in the future for regenerative medicine. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Vaibhav P Pai
- Allen Discovery Center at Tufts University, Medford, Massachusetts, USA
| | - Michael Levin
- Allen Discovery Center at Tufts University, Medford, Massachusetts, USA
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45
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Carvalho J. A computational model of organism development and carcinogenesis resulting from cells' bioelectric properties and communication. Sci Rep 2022; 12:9206. [PMID: 35654933 PMCID: PMC9163332 DOI: 10.1038/s41598-022-13281-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 05/23/2022] [Indexed: 11/15/2022] Open
Abstract
A sound theory of biological organization is clearly missing for a better interpretation of observational results and faster progress in understanding life complexity. The availability of such a theory represents a fundamental progress in explaining both normal and pathological organism development. The present work introduces a computational implementation of some principles of a theory of organism development, namely that the default state of cells is proliferation and motility, and includes the principle of variation and organization by closure of constraints. In the present model, the bioelectric context of cells and tissue is the field responsible for organization, as it regulates cell proliferation and the level of communication driving the system's evolution. Starting from a depolarized (proliferative) cell, the organism grows to a certain size, limited by the increasingly polarized state after successive proliferation events. The system reaches homeostasis, with a depolarized core (proliferative cells) surrounded by a rim of polarized cells (non-proliferative in this condition). This state is resilient to cell death (random or due to injure) and to limited depolarization (potentially carcinogenic) events. Carcinogenesis is introduced through a localized event (a spot of depolarized cells) or by random depolarization of cells in the tissue, which returns cells to their initial proliferative state. The normalization of the bioelectric condition can reverse this out-of-equilibrium state to a new homeostatic one. This simplified model of embryogenesis, tissue organization and carcinogenesis, based on non-excitable cells' bioelectric properties, can be made more realistic with the introduction of other components, like biochemical fields and mechanical interactions, which are fundamental for a more faithful representation of reality. However, even a simple model can give insight for new approaches in complex systems and suggest new experimental tests, focused in its predictions and interpreted under a new paradigm.
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Affiliation(s)
- Joao Carvalho
- CFisUC, Department of Physics, University of Coimbra, Coimbra, Portugal.
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46
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Wong ML, Bartlett S. Asymptotic burnout and homeostatic awakening: a possible solution to the Fermi paradox? J R Soc Interface 2022; 19:20220029. [PMID: 35506212 PMCID: PMC9065981 DOI: 10.1098/rsif.2022.0029] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Previous studies show that city metrics having to do with growth, productivity and overall energy consumption scale superlinearly, attributing this to the social nature of cities. Superlinear scaling results in crises called ‘singularities’, where population and energy demand tend to infinity in a finite amount of time, which must be avoided by ever more frequent ‘resets’ or innovations that postpone the system's collapse. Here, we place the emergence of cities and planetary civilizations in the context of major evolutionary transitions. With this perspective, we hypothesize that once a planetary civilization transitions into a state that can be described as one virtually connected global city, it will face an ‘asymptotic burnout’, an ultimate crisis where the singularity-interval time scale becomes smaller than the time scale of innovation. If a civilization develops the capability to understand its own trajectory, it will have a window of time to affect a fundamental change to prioritize long-term homeostasis and well-being over unyielding growth—a consciously induced trajectory change or ‘homeostatic awakening’. We propose a new resolution to the Fermi paradox: civilizations either collapse from burnout or redirect themselves to prioritizing homeostasis, a state where cosmic expansion is no longer a goal, making them difficult to detect remotely.
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Affiliation(s)
- Michael L Wong
- Earth and Planets Laboratory, Carnegie Institution for Science, Washington, DC 20015, USA
| | - Stuart Bartlett
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
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Davies JA. Synthetic Morphogenesis: introducing IEEE journal readers to programming living mammalian cells to make structures. PROCEEDINGS OF THE IEEE. INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS 2022; 110:688-707. [PMID: 36590991 PMCID: PMC7614003 DOI: 10.1109/jproc.2021.3137077] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Synthetic morphogenesis is a new engineering discipline, in which cells are genetically engineered to make designed shapes and structures. At least in this early phase of the field, devices tend to make use of natural shape-generating processes that operate in embryonic development, but invoke them artificially at times and in orders of a technologist's choosing. This requires construction of genetic control, sequencing and feedback systems that have close parallels to electronic design, which is one reason the field may be of interest to readers of IEEE journals. The other reason is that synthetic morphogenesis allows the construction of two-way interfaces, especially opto-genetic and opto-electronic, between the living and the electronic, allowing unprecedented information flow and control between the two types of 'machine'. This review introduces synthetic morphogenesis, illustrates what has been achieved, drawing parallels wherever possible between biology and electronics, and looks forward to likely next steps and challenges to be overcome.
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Affiliation(s)
- Jamie A Davies
- Professor of Experimental Anatomy at the University of Edinburgh, UK, and a member of the Centre for Mammalian Synthetic Biology at that University
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48
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Levin M. Technological Approach to Mind Everywhere: An Experimentally-Grounded Framework for Understanding Diverse Bodies and Minds. Front Syst Neurosci 2022; 16:768201. [PMID: 35401131 PMCID: PMC8988303 DOI: 10.3389/fnsys.2022.768201] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 01/24/2022] [Indexed: 12/11/2022] Open
Abstract
Synthetic biology and bioengineering provide the opportunity to create novel embodied cognitive systems (otherwise known as minds) in a very wide variety of chimeric architectures combining evolved and designed material and software. These advances are disrupting familiar concepts in the philosophy of mind, and require new ways of thinking about and comparing truly diverse intelligences, whose composition and origin are not like any of the available natural model species. In this Perspective, I introduce TAME-Technological Approach to Mind Everywhere-a framework for understanding and manipulating cognition in unconventional substrates. TAME formalizes a non-binary (continuous), empirically-based approach to strongly embodied agency. TAME provides a natural way to think about animal sentience as an instance of collective intelligence of cell groups, arising from dynamics that manifest in similar ways in numerous other substrates. When applied to regenerating/developmental systems, TAME suggests a perspective on morphogenesis as an example of basal cognition. The deep symmetry between problem-solving in anatomical, physiological, transcriptional, and 3D (traditional behavioral) spaces drives specific hypotheses by which cognitive capacities can increase during evolution. An important medium exploited by evolution for joining active subunits into greater agents is developmental bioelectricity, implemented by pre-neural use of ion channels and gap junctions to scale up cell-level feedback loops into anatomical homeostasis. This architecture of multi-scale competency of biological systems has important implications for plasticity of bodies and minds, greatly potentiating evolvability. Considering classical and recent data from the perspectives of computational science, evolutionary biology, and basal cognition, reveals a rich research program with many implications for cognitive science, evolutionary biology, regenerative medicine, and artificial intelligence.
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Affiliation(s)
- Michael Levin
- Allen Discovery Center at Tufts University, Medford, MA, United States
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Cambridge, MA, United States
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49
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Kudithipudi D, Aguilar-Simon M, Babb J, Bazhenov M, Blackiston D, Bongard J, Brna AP, Chakravarthi Raja S, Cheney N, Clune J, Daram A, Fusi S, Helfer P, Kay L, Ketz N, Kira Z, Kolouri S, Krichmar JL, Kriegman S, Levin M, Madireddy S, Manicka S, Marjaninejad A, McNaughton B, Miikkulainen R, Navratilova Z, Pandit T, Parker A, Pilly PK, Risi S, Sejnowski TJ, Soltoggio A, Soures N, Tolias AS, Urbina-Meléndez D, Valero-Cuevas FJ, van de Ven GM, Vogelstein JT, Wang F, Weiss R, Yanguas-Gil A, Zou X, Siegelmann H. Biological underpinnings for lifelong learning machines. NAT MACH INTELL 2022. [DOI: 10.1038/s42256-022-00452-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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50
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George LF, Bates EA. Mechanisms Underlying Influence of Bioelectricity in Development. Front Cell Dev Biol 2022; 10:772230. [PMID: 35237593 PMCID: PMC8883286 DOI: 10.3389/fcell.2022.772230] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 01/07/2022] [Indexed: 12/25/2022] Open
Abstract
To execute the intricate process of development, cells coordinate across tissues and organs to determine where each cell divides and differentiates. This coordination requires complex communication between cells. Growing evidence suggests that bioelectrical signals controlled via ion channels contribute to cell communication during development. Ion channels collectively regulate the transmembrane potential of cells, and their function plays a conserved role in the development of organisms from flies to humans. Spontaneous calcium oscillations can be found in nearly every cell type and tissue, and disruption of these oscillations leads to defects in development. However, the mechanism by which bioelectricity regulates development is still unclear. Ion channels play essential roles in the processes of cell death, proliferation, migration, and in each of the major canonical developmental signaling pathways. Previous reviews focus on evidence for one potential mechanism by which bioelectricity affects morphogenesis, but there is evidence that supports multiple different mechanisms which are not mutually exclusive. Evidence supports bioelectricity contributing to development through multiple different mechanisms. Here, we review evidence for the importance of bioelectricity in morphogenesis and provide a comprehensive review of the evidence for several potential mechanisms by which ion channels may act in developmental processes.
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Affiliation(s)
- Laura Faith George
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, United States
| | - Emily Anne Bates
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, United States
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