Syncytia: Origin, Structure, and Functions (Results and Problems in Cell Differentiation, 71)

✍ Scribed by Malgorzata Kloc (editor), Ahmed Uosef (editor)

• Publisher: Springer
• Year: 2023
• Tongue: English
• Leaves: 480
• Category: Library

✦ Synopsis

This book gives a current overview on the development, origin, structure, and functions of germline and somatic cell syncytia during embryogenesis and organogenesis. It also reviews pathogen-induced syncytia and the role of syncytial cells in cancer development.

The book covers the following topics:

• germline syncytia, evolution, function and structure;
• syncytia in embryogenesis and development;
• the role of somatic cell fusion in fungi, specialized somatic tissues, host defense and adaptation;
• syncytia induced by viruses and parasites;
• syncytia and circulating hybrid cells in cancer and other pathological conditions;

It also discusses how the genomic adaptations of microorganisms to extreme habitats can prompt the evolution of mononuclear and multinucleate/syncytial cells.

The book offers a fresh outlook on syncytia's role in various processes: embryogenesis, organogenesis, adaptation, host defense, and development of specialized tissues. It highlights the importance of syncytia under physiological and pathological conditions.

✦ Table of Contents

Preface
Book Abstract
Contents
Part I: Germline Syncytia, Evolution, Function, and Structure
Chapter 1: The Ancient Origin and Function of Germline Cysts
1.1 Animals Evolved Special Germline Cells to Propagate a Complex Multicellular System
1.2 Animals Expanded the Protist Meiotic Program by Adding Germline Cysts
1.3 Cysts Are Ancient and Are Built by a Conserved Process
1.4 Early Metazoan Animals Also Use Cellular Cysts Downstream from Stem Cells
1.5 Multipotent Stem Cells Use CGGs to Control Transposable Elements
1.6 Hydra ISCs Give Rise to Somatic Cnidoblast Cells Using a Pathway Like the Germline Cyst
1.7 Germline Cysts in Hydra and Planaria Downstream from Male GSCs Also Parallel Their Function in Advanced Animal Testes
1.8 Female GSCs Develop into Clusters That Generate Oocytes and Either Differentiate or Acquire Nurse Cells
1.9 Cysts May Be Needed to Synchronize Downstream Cells and Modify Their Cell Cycles
1.10 Drosophila Female GSC Daughters Become Epigenetically Modified Within Cysts Like Pre-blastoderm Nuclei in the Syncytial Embryo
1.11 Cysts and Syncytia May Have Evolved to Limit Germline Parasites
1.12 Concluding Thoughts
References
Chapter 2: Female Germline Cysts in Animals: Evolution and Function
2.1 Introduction
2.2 Oogenic Cysts in Drosophila melanogaster: The Standard Model
2.3 Of Mice and Flies: Apparent Conservation of Female Cysts
2.4 Cyst Evolution in Hexapods: A Case Study
2.4.1 Ovariole Diversity in Hexapods
2.4.2 Phylogenetic Context: Female Cysts Are Not Ancestral Features of Insect Oogenesis
2.4.3 Diversity of Cyst Types in Eumetabolan Insects
2.5 Diversity of Female Germline Cysts in Other Animal Lineages
2.5.1 Overview
2.5.2 Non-bilaterian Phyla: Sponges and Cnidarians
2.5.3 Annelids
2.5.4 Vertebrates
2.5.5 Major Taxa in Which Female Cysts Have Not Been Described
2.6 Concluding Thoughts: The Function(s) of Female Germline Cysts
References
Chapter 3: Germline and Somatic Cell Syncytia in Insects
3.1 Types and Origin of Syncytia and Giant Cells
3.2 Insect Germline Syncytia
3.2.1 Syncytia in Spermatogenesis
3.2.2 Syncytia in Oogenesis
3.3 Insect Somatic Cell Syncytia
3.3.1 Epithelial Syncytia
3.3.2 Multinucleated Giant Cells in Insect Immune Response
3.3.3 Muscle Cell Syncytia
References
Part II: Syncytia in Embryogenesis and Development
Chapter 4: Reshaping the Syncytial Drosophila Embryo with Cortical Actin Networks: Four Main Steps of Early Development
4.1 Introduction
4.2 Axial Expansion: Spreading Nuclei Along the Anterior–posterior Axis of the Embryo
4.2.1 General Context
4.2.2 The Role and Regulation of an Embryo-Wide Actomyosin Network
4.3 Pole Cell Budding: Separating Mono-nucleated Germline Cells from the Syncytial Soma
4.3.1 General Context
4.3.2 The Roles and Regulation of Local Actomyosin Networks
4.4 The Syncytial Blastoderm: Repeated Cortical Compartmentalization for Dividing Somatic Nuclei
4.4.1 General Context
4.4.2 Induction and Growth of an Actin Cap
4.4.3 Coupling Cap Growth with the Mitotic Spindle
4.4.4 Coupling Cap Growth with the Surrounding Actomyosin Network
4.5 Cellularization: Making the First Embryonic Epithelium
4.5.1 General Context
4.5.2 Coupling Membrane Trafficking and Actin Networks
4.6 Concluding Remarks
References
Chapter 5: Cell-Mediated Branch Fusion in the Drosophila Trachea
5.1 Overview of Tracheal Development and Branch Fusion
5.2 Fusion Cell Specification
5.3 Branch Fusion Process
5.3.1 Cell–Cell Contact Between Two Fusion Cells
5.3.2 Formation of the Cytoskeleton Track and Vesicular Trafficking
5.3.3 Lumen Fusion
5.4 Summary
References
Chapter 6: Trophoblast Syncytialization: A Metabolic Crossroads
6.1 Overview of Syncytialization in Villous Trophoblasts
6.1.1 The Role of Adhesive and Junctional Proteins in Trophoblast Fusion
6.1.2 Consequences of Improper Syncytialization: The Role of Apoptosis in the Formation of Syncytial Knots
6.1.3 Hypoxic Signaling Regulates Trophoblast Differentiation
6.2 Mitochondrial Dynamics and Signaling in Syncytialization
6.2.1 Mitochondrial Dynamics: A Balance Between Fission and Fusion
6.3 Characteristic Energetic Profiles Associated with Mitochondrial Morphologies
6.4 Metabolic Nuances in Stem Cell Fate Decisions
6.5 Mitochondria in Trophoblast Syncytialization
6.6 Clinical Implications of Mitochondrial Morphology and Bioenergetics in Syncytialization
References
Chapter 7: Early Syncytialization of the Ovine Placenta Revisited
7.1 Introduction
7.2 Immunofluorescence Microscopy Analyses Identify the Possible Destiny of Specific Cells Engaged in Syncytialization
7.3 Are BNCs the Only Cells That Migrate into the Uterine Luminal Epithelium?
7.4 What Is the Fate of Uterine LE During Syncytialization?
7.5 Based on This Scenario, Several Factors Remain to Be Clarified
7.6 Conclusions
References
Chapter 8: Syncytia in Utricularia: Origin and Structure
8.1 Introduction
8.2 Utricularia (Bladderworts)
8.2.1 Syncytium Occurrence
8.2.2 Placental Nutritive Tissues and “Naked” Embryo Sacs
8.2.3 Syncytium Development
8.2.3.1 Syncytium as “Super” Transfer Cell
8.2.3.2 Syncytium Ultrastructure and Organization
8.3 Conclusions
References
Part III: Fungal and Somatic Cell Syncytia and Genomic View of Extremophiles as the Ancestral Precursors of Eukaryotic Syncytia
Chapter 9: Syncytial Assembly Lines: Consequences of Multinucleate Cellular Compartments for Fungal Protein Synthesis
9.1 Introduction
9.2 Heterogeneous Responses, Nuclear Autonomy, and Collective Behavior
9.3 Partitioning of the Cytoplasm
9.4 Coordinating Across the Mycelium
9.5 Implications of Syncytial Cell Structure for Protein Synthesis
9.6 Circadian Rhythm Through the Lens of Nuclear Coordination
9.7 Perspectives
References
Chapter 10: Ancestors in the Extreme: A Genomics View of Microbial Diversity in Hypersaline Aquatic Environments
10.1 Introduction
10.2 Materials and Methods
10.2.1 The Study Site
10.2.2 Sample Collection and Processing
10.2.3 Physico-chemical Analysis and Water Isotope Measurement
10.2.4 DNA Extraction and Metagenome Sequence Processing
10.2.5 Taxonomy Profiling and Statistical Analysis
10.2.5.1 Mapping of Direct Assembly-Free Sequence Reads
10.2.5.2 Taxonomy Binning of Metagenome-Assembled Reads
10.2.5.3 Functional Binning of Metagenome-Assembled Genomes (MAGs) and Prediction of Chaperone Proteins
10.3 Results
10.3.1 Geochemical and Physico-chemical Properties
10.3.2 Microbial Richness in the Shorelines of Lake As’ale and MUP
10.3.3 Diversity of Extremophilic Prokaryotes
10.3.4 Prediction of Proteins Involved in Stress Response in Lake As’ale and MUP
10.4 Discussion
10.5 Conclusion
References
Chapter 11: Somatic Cell Fusion in Host Defense and Adaptation
11.1 Introduction
11.2 Identification of Somatic Cell Fusion
11.3 Adaptive Evolution of Hybrid Cells and Viruses
11.4 Hurdles to Detecting and Investigating Somatic Cell Fusion
11.5 Consideration of Cell Fusion in Host Defense and Adaptation to Environmental Challenge
11.5.1 Immunity
11.5.2 Regeneration
11.6 Concluding Remarks
References
Chapter 12: Osteoclasts at Bone Remodeling: Order from Order
12.1 Hierarchical Regulation of Osteoclastogenesis: Interaction Among Homeostatic Systems
12.2 Bone, Bone Marrow, and Vascular Network
12.3 Bone Remodeling
12.4 Precursor Migration
12.5 Cell Proliferation
12.6 Osteoclast Niche
12.7 Regulation of RANKL Binding with RANK
12.8 Lifespan of Osteoclasts
12.9 Fusion and Fission of Osteoclasts
12.9.1 Actin-Based Linking Structures During Fusion
12.9.2 Actin Wave at the Nonequilibrium State
12.9.3 Fission of Osteoclasts
12.9.4 Fission at Nonequilibrium
12.10 Cortical Actin
12.11 Role of Fusion in Osteoclastogenesis
12.12 Perspectives
References
Chapter 13: Muscle Progenitor Cell Fusion in the Maintenance of Skeletal Muscle
13.1 Introduction
13.2 Skeletal Muscle Requires Rapid Repair/Regeneration Mechanisms for Lifelong Maintenance
13.2.1 Plasma Membrane Lesions Undergo Patching via Ca2+ Regulated Exocytic Repair
13.2.1.1 General Membrane Patch Repair Mechanism
13.2.2 Skeletal Muscle Employs a Multipotent Stem Cell Population in Fiber Repair/Regeneration
13.3 Satellite Cell-Dependent Muscle Repair: A Trip Back to Development?
13.3.1 Myogenic Progression of Progenitor Cells in Skeletal Muscle
13.3.2 Satellite Cells Become Activated and Migrate to Tissue Damage upon Muscle Injury
13.3.3 Proliferation of Myogenic Daughter Cells for Contribution to the Musculature
13.4 Satellite Cell Differentiation
13.5 Muscle Fusion in Fiber Repair and Regeneration
13.5.1 Adhesion Proteins in Muscle Fusion
13.5.2 Membrane Signaling in Muscle Recognition/Fusion
13.5.3 The Skeletal Muscle Bipartite Fusion Machine
13.5.4 Other Players in Muscle Cell Fusion
13.6 Conclusion
References
Part IV: Virus- and Parasite-Induced Syncytia
Chapter 14: Virus-Induced Cell Fusion and Syncytia Formation
14.1 Introduction
14.2 Human Endogenous Retroviruses
14.3 Human Immunodeficiency Viruses
14.4 Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)
14.5 Herpesviridae
14.5.1 The Core Fusion Machinery for Herpesvirus
14.5.2 Herpes Simplex Virus
14.5.3 Human Cytomegalovirus
14.5.4 Human Herpesvirus 6
14.6 Reoviridae
14.7 Conclusions
References
Chapter 15: HIV-1 Induced Cell-to-Cell Fusion or Syncytium Formation
15.1 Introduction
15.2 HIV-1 Entry, Cellular Targets, and Tropism
15.3 Cell-Cell HIV-1 Transmission in Macrophages
15.4 Phagocytosis and HIV-1 Entry
15.5 Cell-Cell Fusion in HIV-1 Entry
15.6 Tunnelling Nanotubes and HIV-1
15.7 Limitations: Biological Knowledge Gaps
15.8 Conclusion
References
Chapter 16: Relevance of the Entry by Fusion at the Cytoplasmic Membrane vs. Fusion After Endocytosis in the HIV and SARS-Cov-2 Infections
16.1 Introduction
16.2 Fusion at the Cytoplasmic Membrane vs. Endocytosis in the SARS-Cov-2 Infection
16.3 Fusion at the Cytoplasmic Membrane vs. Endocytosis in HIV Entry
16.4 Expression of the Viral Fusion Protein at the Cell Membrane Is Required for Membrane Fusion and Syncytia Formation
16.5 Membrane Cofactors Involved in Virus-Dependent Membrane Fusion
16.6 Conclusions
References
Chapter 17: Mathematical Modeling of Virus-Mediated Syncytia Formation: Past Successes and Future Directions
17.1 Introduction
17.2 Mathematical Models of Virus-Mediated Cell Fusion
17.2.1 General Role in Viral Infection
17.2.2 Cell-Cell Fusion Assay
17.2.3 Oncolytic Viruses
17.3 Future Directions
17.3.1 Experiments
17.3.2 Models
17.4 Conclusions
References
Chapter 18: Syncytium Induced by Plant-Parasitic Nematodes
18.1 Introduction
18.2 Plant-Parasitic Nematodes
18.3 Structure of Syncytia in Susceptible Plants
18.4 Molecular Basis of Nematode–Plant Interaction and Susceptibility Genes
18.5 Resistance Response
18.6 Hypersensitive Response Activated by Plant-Parasitic Nematodes
18.7 Concluding Remarks
References
Part V: Cell Fusion and Syncytia in Cancer
Chapter 19: Mechanisms of Cell Fusion in Cancer
19.1 Introduction
19.2 Mechanisms of Cancer Cell Fusion
19.2.1 Intrinsic Factors
19.2.1.1 Syncytins, the Human Endogenous Retrovirus Envelope Genes (HERV env) and Cancer Cell Fusion
19.2.1.2 Phosphatidylserine
19.2.1.3 Annexins and Glucose-Regulated Protein 78 (GRP78)
19.2.2 Extracellular Factors
19.2.2.1 Inflammation, Inflammatory Cytokines, and Signaling Pathways
19.2.2.2 Virus
19.2.2.3 Mediators of Cell Stress and Other Factors (Hypoxia, Radiotherapy, Chemotherapy, pH, Exosomes, Cellocytosis, Entosis)
19.3 Conclusion
References
Chapter 20: Cell Fusion and Syncytia Formation in Cancer
20.1 Introduction
20.2 How Does Cell–Cell Fusion Work and Which Proteins/Mediators Are Involved?
20.3 Does Cell–Cell Fusion Naturally Occur in Cancer?
20.3.1 Syncytin-1 Contributes to Cancer-Cell Fusion and Progression
20.3.2 Phosphatidylserine as Possible Cell Fusion Mediator in Cancer
20.4 How Do Tumor Hybrid Cells Survive and How Does Fusion Alter Them?
20.4.1 The Post-hybrid Selection Process (PHSP)
20.4.2 Stable Cancer Hybrid Cells Show Altered Properties Within the Tumor
20.5 How Can Tumor Hybrid Cells Be Detected In Vitro and In Vivo?
20.5.1 Detection of Cancer Hybrid Cells In Vitro and In Vivo in an Experimental Setup
20.5.2 Detection of Cancer Hybrid Cells In Vivo in Human Cancers
20.5.3 Detection of Circulating Hybrid Cells (CHCs) in the Blood of Human Cancer Patients
20.6 Conclusions
References
Chapter 21: The Hallmarks of Circulating Hybrid Cells
21.1 Introduction
21.2 Tumor-Promoting Inflammation
21.3 Genomic Instability and Acquisition of Mutations
21.4 Unlocking Phenotypic Plasticity
21.5 Invasion and Dissemination into Vasculature
21.6 Avoiding Immune Destruction
21.7 Impact of Cell Fusion in Cancer
21.8 Prospectus
References