-
Cold Spring Harbor Perspectives in... Apr 2018Cell-cell junctions link cells to each other in tissues, and regulate tissue homeostasis in critical cell processes that include tissue barrier function, cell... (Review)
Review
Cell-cell junctions link cells to each other in tissues, and regulate tissue homeostasis in critical cell processes that include tissue barrier function, cell proliferation, and migration. Defects in cell-cell junctions give rise to a wide range of tissue abnormalities that disrupt homeostasis and are common in genetic abnormalities and cancers. Here, we discuss the organization and function of cell-cell junctions primarily involved in adhesion (tight junction, adherens junction, and desmosomes) in two different epithelial tissues: a simple epithelium (intestine) and a stratified epithelium (epidermis). Studies in these tissues reveal similarities and differences in the organization and functions of different cell-cell junctions that meet the requirements for the specialized functions of each tissue. We discuss cell-cell junction responses to genetic and environmental perturbations that provide further insights into their roles in maintaining tissue homeostasis.
Topics: Adherens Junctions; Animals; Cell Movement; Cell Proliferation; Desmosomes; Epithelial Cells; Epithelium; Homeostasis; Humans; Intercellular Junctions; Intestinal Mucosa; Signal Transduction; Tight Junctions; Wound Healing
PubMed: 28600395
DOI: 10.1101/cshperspect.a029181 -
Physiological Reviews Jul 2004Intercellular junctions mediate adhesion and communication between adjoining endothelial and epithelial cells. In the endothelium, junctional complexes comprise tight... (Review)
Review
Intercellular junctions mediate adhesion and communication between adjoining endothelial and epithelial cells. In the endothelium, junctional complexes comprise tight junctions, adherens junctions, and gap junctions. The expression and organization of these complexes depend on the type of vessels and the permeability requirements of perfused organs. Gap junctions are communication structures, which allow the passage of small molecular weight solutes between neighboring cells. Tight junctions serve the major functional purpose of providing a "barrier" and a "fence" within the membrane, by regulating paracellular permeability and maintaining cell polarity. Adherens junctions play an important role in contact inhibition of endothelial cell growth, paracellular permeability to circulating leukocytes and solutes. In addition, they are required for a correct organization of new vessels in angiogenesis. Extensive research in the past decade has identified several molecular components of the tight and adherens junctions, including integral membrane and intracellular proteins. These proteins interact both among themselves and with other molecules. Here, we review the individual molecules of junctions and their complex network of interactions. We also emphasize how the molecular architectures and interactions may represent a mechanistic basis for the function and regulation of junctions, focusing on junction assembly and permeability regulation. Finally, we analyze in vivo studies and highlight information that specifically relates to the role of junctions in vascular endothelial cells.
Topics: Adherens Junctions; Animals; Blood Vessels; Endothelium, Vascular; Homeostasis; Humans; Intercellular Junctions; Tight Junctions
PubMed: 15269339
DOI: 10.1152/physrev.00035.2003 -
Biophysical Journal Aug 2023Tissue cells in epithelial or endothelial monolayers are connected through cell-cell junctions, which are stabilized by transmembrane E-cadherin bonds and intracellular...
Tissue cells in epithelial or endothelial monolayers are connected through cell-cell junctions, which are stabilized by transmembrane E-cadherin bonds and intracellular actin filaments. These bonds and junctions play a crucial role in maintaining the barrier function of epithelia and endothelia and are believed to transmit forces between cells. Additionally, E-cadherin bonds can impact the shape of cell-cell junctions. In this study, we develop a continuum mechanical model of the cell-cell junction by explicitly incorporating the cell membrane, distributions of E-cadherin bonds, cytoplasmic fluid pressure, and F-actin dynamics. The static force-balanced version of the model is able to analyze the influences of cell cortical tension, actin dynamics, and cytoplasmic pressure on the junction shape and E-cadherin bonds. Furthermore, an extended model that incorporates fluid flow, across the cell boundary as well as around the cell, is also examined. This model can couple cell-shape changes with cell cortical tension and fluid flow, and predicts the additional effect of fluid motion on cell-cell junction mechanics. Taken together, our models serve as an intermediate link between molecular-scale models of cell-junction molecules and cell-scale models of tissue and epithelia.
Topics: Intercellular Junctions; Cadherins; Actins; Cell Membrane; Actin Cytoskeleton
PubMed: 37475215
DOI: 10.1016/j.bpj.2023.07.011 -
Current Biology : CB Mar 2020Bosveld and Bellaïche discuss the composition and assembly of tricellular junctions, as well as their roles in cell packing, tissue mechanics and signalling.
Bosveld and Bellaïche discuss the composition and assembly of tricellular junctions, as well as their roles in cell packing, tissue mechanics and signalling.
Topics: Animals; Biomechanical Phenomena; Epithelial Cells; Humans; Intercellular Junctions; Signal Transduction
PubMed: 32208143
DOI: 10.1016/j.cub.2020.01.029 -
Tissue Barriers Jan 2021Epithelial and endothelial cell-cell contacts are established and maintained by several intercellular junctional complexes. These structurally and biochemically... (Review)
Review
Epithelial and endothelial cell-cell contacts are established and maintained by several intercellular junctional complexes. These structurally and biochemically differentiated regions on the plasma membrane primarily include tight junctions (TJs), and anchoring junctions. While the adherens junctions (AJs) provide essential adhesive and mechanical properties, TJs hold the cells together and form a near leak-proof intercellular seal by the fusion of adjacent cell membranes. AJs and TJs play essential roles in vascular permeability. Considering their involvement in several key cellular functions such as barrier formation, proliferation, migration, survival, and differentiation, further research is warranted on the composition and signaling pathways regulating cell-cell junctions to develop novel therapeutics for diseases such as organ injuries. The current review article presents our current state of knowledge on various cell-cell junctions, their molecular composition, and mechanisms regulating their expression and function in endothelial and epithelial cells.
Topics: Epithelial Cells; Humans; Intercellular Junctions
PubMed: 33300427
DOI: 10.1080/21688370.2020.1848212 -
Current Opinion in Structural Biology Apr 2008Aquaporins (AQPs) are a family of ubiquitous membrane channels that conduct water and solutes across membranes. This review focuses on AQP0 and AQP4, which in addition... (Review)
Review
Aquaporins (AQPs) are a family of ubiquitous membrane channels that conduct water and solutes across membranes. This review focuses on AQP0 and AQP4, which in addition to forming water channels also appear to play a role in cell adhesion. We discuss the recently determined structures of the membrane junctions mediated by these two AQPs, the mechanisms that regulate junction formation, and evidence that supports a role for AQP0 and AQP4 in cell adhesion.
Topics: Animals; Aquaporin 4; Aquaporins; Eye Proteins; Humans; Intercellular Junctions; Models, Molecular; Protein Structure, Quaternary
PubMed: 18194855
DOI: 10.1016/j.sbi.2007.11.003 -
Cold Spring Harbor Perspectives in... Apr 2017Collective cell migration critically depends on cell-cell interactions coupled to a dynamic actin cytoskeleton. Important cell-cell adhesion receptor systems implicated... (Review)
Review
Collective cell migration critically depends on cell-cell interactions coupled to a dynamic actin cytoskeleton. Important cell-cell adhesion receptor systems implicated in controlling collective movements include cadherins, immunoglobulin superfamily members (L1CAM, NCAM, ALCAM), Ephrin/Eph receptors, Slit/Robo, connexins and integrins, and an adaptive array of intracellular adapter and signaling proteins. Depending on molecular composition and signaling context, cell-cell junctions adapt their shape and stability, and this gradual junction plasticity enables different types of collective cell movements such as epithelial sheet and cluster migration, branching morphogenesis and sprouting, collective network migration, as well as coordinated individual-cell migration and streaming. Thereby, plasticity of cell-cell junction composition and turnover defines the type of collective movements in epithelial, mesenchymal, neuronal, and immune cells, and defines migration coordination, anchorage, and cell dissociation. We here review cell-cell adhesion systems and their functions in different types of collective cell migration as key regulators of collective plasticity.
Topics: Animals; Cell Adhesion; Cell Movement; Humans; Intercellular Junctions; Neoplasms
PubMed: 28096261
DOI: 10.1101/cshperspect.a029199 -
Tissue Barriers 2020Tendons connect muscles to bones to transfer the forces necessary for movement. Cell-cell junction proteins, cadherins and connexins, may play a role in tendon...
Tendons connect muscles to bones to transfer the forces necessary for movement. Cell-cell junction proteins, cadherins and connexins, may play a role in tendon development and injury. In this review, we begin by highlighting current understanding of how cell-cell junctions may regulate embryonic tendon development and differentiation. We then examine cell-cell junctions in postnatal tendon, before summarizing the role of cadherins and connexins in adult tendons. More information exists regarding the role of cell-cell junctions in the formation and homeostasis of other musculoskeletal tissues, namely cartilage and bone. Therefore, to inform future tendon studies, we include a brief survey of cadherins and connexins in chondrogenesis and osteogenesis, and summarize how cell-cell junctions are involved in some musculoskeletal tissue pathologies. An enhanced understanding of how cell-cell junctions participate in tendon development, maintenance, and disease will benefit future regenerative strategies.
Topics: Cell Differentiation; Humans; Intercellular Junctions; Tendons; Tissue Engineering
PubMed: 31818195
DOI: 10.1080/21688370.2019.1695491 -
Biochimica Et Biophysica Acta.... Sep 2020Epithelial and endothelial monolayers are multicellular sheets that form barriers between the 'outside' and 'inside' of tissues. Cell-cell junctions, made by adherens... (Review)
Review
Epithelial and endothelial monolayers are multicellular sheets that form barriers between the 'outside' and 'inside' of tissues. Cell-cell junctions, made by adherens junctions, tight junctions and desmosomes, hold together these monolayers. They form intercellular contacts by binding their receptor counterparts on neighboring cells and anchoring these structures intracellularly to the cytoskeleton. During tissue development, maintenance and pathogenesis, monolayers encounter a range of mechanical forces from the cells themselves and from external systemic forces, such as blood pressure or tissue stiffness. The molecular landscape of cell-cell junctions is diverse, containing transmembrane proteins that form intercellular bonds and a variety of cytoplasmic proteins that remodel the junctional connection to the cytoskeleton. Many junction-associated proteins participate in mechanotransduction cascades to confer mechanical cues into cellular responses that allow monolayers to maintain their structural integrity. We will discuss force-dependent junctional molecular events and their role in cell-cell contact organization and remodeling.
Topics: Adherens Junctions; Blood Pressure; Cytoskeleton; Desmosomes; Endothelial Cells; Epithelial Cells; Humans; Intercellular Junctions; Mechanical Phenomena; Membrane Proteins; Tight Junctions
PubMed: 32360073
DOI: 10.1016/j.bbamem.2020.183316 -
Current Biology : CB Apr 2018Cell-cell junctions are specializations of the plasma membrane responsible for physically integrating cells into tissues. We are now beginning to appreciate the diverse... (Review)
Review
Cell-cell junctions are specializations of the plasma membrane responsible for physically integrating cells into tissues. We are now beginning to appreciate the diverse impacts that mechanical forces exert upon the integrity and function of these junctions. Currently, this is best understood for cadherin-based adherens junctions in epithelia and endothelia, where cell-cell adhesion couples the contractile cytoskeletons of cells together to generate tissue-scale tension. Junctional tension participates in morphogenesis and tissue homeostasis. Changes in tension can also be detected by mechanotransduction pathways that allow cells to communicate with each other. In this review, we discuss progress in characterising the forces present at junctions in physiological conditions; the cellular mechanisms that generate intrinsic tension and detect changes in tension; and, finally, we consider how tissue integrity is maintained in the face of junctional stresses.
Topics: Adherens Junctions; Animals; Cadherins; Cell Adhesion; Cell Membrane; Cytoskeleton; Epithelium; Humans; Intercellular Junctions; Mechanotransduction, Cellular; Tensile Strength
PubMed: 29689229
DOI: 10.1016/j.cub.2018.02.003