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IScience Dec 2022Podosomes, an important actin-based adhesive architecture, play critical roles in cell migration and matrix invasiveness. Here, we elucidate the ultrastructural...
Podosomes, an important actin-based adhesive architecture, play critical roles in cell migration and matrix invasiveness. Here, we elucidate the ultrastructural organization and regulation of podosome clusters in primary macrophages. With three-dimensional stochastic optical reconstruction microscopy (3D-STORM), we achieve ∼20/50 nm (lateral/axial) spatial resolution to resolve the mutual localization of podosome core and ring components, and further show that microtubules pass through podosomes at the layer of myosin IIA. The microtubule disruption-caused podosome dissolution is previously ascribed to Rho/ROCK-myosin signaling, yet inhibiting this pathway with Y27632 or blebbistatin only partially recovers podosome assembly, thus suggesting the contribution of the physical supporting of microtubules in stabilizing podosome structures. Through improved substrate-coating technique, we further corroborate that the matrix-degrading capability of macrophages depends on the formation of podosome clusters. Together, 3D-STORM super-resolution microscopy reveals the nanoscale spatial arrangement and the microtubule-dependent regulation of the matrix-degrading podosome clusters in macrophages.
PubMed: 36425766
DOI: 10.1016/j.isci.2022.105514 -
Nature Communications May 2023Immune cells, such as macrophages and dendritic cells, can utilize podosomes, mechanosensitive actin-rich protrusions, to generate forces, migrate, and patrol for...
Immune cells, such as macrophages and dendritic cells, can utilize podosomes, mechanosensitive actin-rich protrusions, to generate forces, migrate, and patrol for foreign antigens. Individual podosomes probe their microenvironment through periodic protrusion and retraction cycles (height oscillations), while oscillations of multiple podosomes in a cluster are coordinated in a wave-like fashion. However, the mechanisms governing both the individual oscillations and the collective wave-like dynamics remain unclear. Here, by integrating actin polymerization, myosin contractility, actin diffusion, and mechanosensitive signaling, we develop a chemo-mechanical model for podosome dynamics in clusters. Our model reveals that podosomes show oscillatory growth when actin polymerization-driven protrusion and signaling-associated myosin contraction occur at similar rates, while the diffusion of actin monomers drives wave-like coordination of podosome oscillations. Our theoretical predictions are validated by different pharmacological treatments and the impact of microenvironment stiffness on chemo-mechanical waves. Our proposed framework can shed light on the role of podosomes in immune cell mechanosensing within the context of wound healing and cancer immunotherapy.
Topics: Podosomes; Actins; Macrophages
PubMed: 37217555
DOI: 10.1038/s41467-023-38598-z -
Biochimica Et Biophysica Acta.... Apr 2019Extensive in vitro studies have described podosomes as actin-based structures at the plasma membrane, connecting the cell with its extracellular matrix and endowed with... (Review)
Review
Extensive in vitro studies have described podosomes as actin-based structures at the plasma membrane, connecting the cell with its extracellular matrix and endowed with multiple capabilities. Contractile actin-myosin cables assemble them into a network that constitutes a multifaceted cellular superstructure taking different forms - with common characteristics - but manifesting different properties depending on the context of study. Their morphology and their role in cell functioning and behavior are therefore now apprehended in in vivo or in vitro situations relevant to physiological processes. We focus here on three of them, namely: macrophage migration, antigen presentation by dendritic cells and endothelial cell sprouting during angiogenesis to highlight the characteristics of podosomes and their functioning shaped by the microenvironment.
Topics: Antigen Presentation; Cell Membrane; Cell Movement; Dendritic Cells; Endothelium, Vascular; Gene Expression; Macrophages; Neovascularization, Physiologic; Podosomes; Signal Transduction
PubMed: 30594495
DOI: 10.1016/j.bbamcr.2018.12.009 -
Journal of Cell Science Jul 2013Remodeling of extracellular matrix (ECM) is a fundamental cell property that allows cells to alter their microenvironment and move through tissues. Invadopodia and... (Review)
Review
Remodeling of extracellular matrix (ECM) is a fundamental cell property that allows cells to alter their microenvironment and move through tissues. Invadopodia and podosomes are subcellular actin-rich structures that are specialized for matrix degradation and are formed by cancer and normal cells, respectively. Although initial studies focused on defining the core machinery of these two structures, recent studies have identified inputs from both growth factor and adhesion signaling as crucial for invasive activity. This Commentary will outline the current knowledge on the upstream signaling inputs to invadopodia and podosomes and their role in governing distinct stages of these invasive structures. We discuss invadopodia and podosomes as adhesion structures and highlight new data showing that invadopodia-associated adhesion rings promote the maturation of already-formed invadopodia. We present a model in which growth factor stimulation leads to phosphoinositide 3-kinase (PI3K) activity and formation of invadopodia, whereas adhesion signaling promotes exocytosis of proteinases at invadopodia.
Topics: Actins; Animals; Cell Adhesion Molecules; Cell Movement; Cellular Microenvironment; Exocytosis; Extracellular Matrix; Humans; Intercellular Signaling Peptides and Proteins; Neoplasm Invasiveness; Phosphatidylinositol 3-Kinases; Pseudopodia; Signal Transduction
PubMed: 23843616
DOI: 10.1242/jcs.079475 -
International Journal of Molecular... Mar 2018Osteoclasts form a specialized cell-matrix adhesion structure, known as the "sealing zone", during bone resorption. The sealing zone is a dynamic actin-rich structure... (Review)
Review
Osteoclasts form a specialized cell-matrix adhesion structure, known as the "sealing zone", during bone resorption. The sealing zone is a dynamic actin-rich structure that defines the resorption area of the bone. The detailed dynamics and fine structure of the sealing zone have been elusive. Osteoclasts plated on glass do not form a sealing zone, but generate a separate supra-molecular structure called the "podosome belt". Podosomes are integrin-based adhesion complexes involved in matrix adhesion, cell migration, matrix degradation, and mechanosensing. Invadopodia, podosome-like protrusions in cancer cells, are involved in cell invasion into other tissues by promoting matrix degradation. Both podosomes and invadopodia exhibit actin pattern transitions during maturation. We previously found that Arp2/3-dependent actin flow occurs in all observed assembly patterns of podosomes in osteoclasts on glass. It is known that the actin wave in cells exhibits a similar pattern transition in its evolution. Because of significant advances in our understanding regarding the mechanism of podosomes/invadopodia formation over the last decade, we revisited the structure and function of the sealing zone in this review, highlighting the possible involvement of self-organized actin waves in the organogenesis of the sealing zone.
Topics: Actin-Related Protein 2-3 Complex; Animals; Bone Resorption; Cell Adhesion; Cell Differentiation; Cell Movement; Humans; Osteoclasts; Podosomes
PubMed: 29587415
DOI: 10.3390/ijms19040984 -
Cell Adhesion & Migration 2014Cell migration and invasion involve the formation of cell adhesion structures as well as the dynamic and spatial regulation of the cytoskeleton. The adhesive structures... (Review)
Review
Cell migration and invasion involve the formation of cell adhesion structures as well as the dynamic and spatial regulation of the cytoskeleton. The adhesive structures known as podosomes and invadopodia share a common role in cell motility, adhesion, and invasion, and form when the plasma membrane of motile cells undergoes highly regulated protrusions. Palladin, a molecular scaffold, co-localizes with actin-rich structures where it plays a role in their assembly and maintenance in a wide variety of cell lines. Palladin regulates actin cytoskeleton organization as well as cell adhesion formation. Moreover, palladin contributes to the invasive nature of cancer metastatic cells by regulating invadopodia formation. Palladin seems to regulate podosome and invodopodia formation through Rho GTPases, which are known as key players in coordinating the cellular responses required for cell migration and metastasis.
Topics: Actin Cytoskeleton; Animals; Cell Adhesion; Cell Movement; Cell Surface Extensions; Cytoskeletal Proteins; Humans; Neoplasm Invasiveness; Neoplasm Metastasis; Neoplasms; Phosphoproteins; Protein Isoforms; rho GTP-Binding Proteins
PubMed: 24525547
DOI: 10.4161/cam.28024 -
The FEBS Journal Jan 2018Invadopodia and podosomes are discrete, actin-based molecular protrusions that form in cancer cells and normal cells, respectively, in response to diverse signaling... (Review)
Review
Invadopodia and podosomes are discrete, actin-based molecular protrusions that form in cancer cells and normal cells, respectively, in response to diverse signaling pathways and extracellular matrix cues. Although they participate in a host of different cellular processes, they share a common functional theme of controlling pericellular proteolytic activity, which sets them apart from other structures that function in migration and adhesion, including focal adhesions, lamellipodia, and filopodia. In this review, we highlight research that explores the function of these complex structures, including roles for podosomes in embryonic and postnatal development, in angiogenesis and remodeling of the vasculature, in maturation of the postsynaptic membrane, in antigen sampling and recognition, and in cell-cell fusion mechanisms, as well as the involvement of invadopodia at multiple steps of the metastatic cascade, and how all of this may apply in the treatment of human disease states. Finally, we explore recent research that implicates a novel role for exosomes and microvesicles in invadopodia-dependent and invadopodia-independent mechanisms of invasion, respectively.
Topics: Animals; Cell Surface Extensions; Exosomes; Focal Adhesions; Humans; Neoplasm Invasiveness; Neoplasms; Podosomes; Pseudopodia
PubMed: 28548369
DOI: 10.1111/febs.14123 -
Cell Cycle (Georgetown, Tex.) 2015The vascular basement membrane (BM) is a thin and dense cross-linked extracellular matrix layer that covers and protects blood vessels. Understanding how cells cross the... (Review)
Review
The vascular basement membrane (BM) is a thin and dense cross-linked extracellular matrix layer that covers and protects blood vessels. Understanding how cells cross the physical barrier of the vascular BM will provide greater insight into the potentially critical role of vascular BM breaching in cancer extravasation, leukocyte trafficking and angiogenic sprouting. In the last year, new evidence has mechanistically linked the breaching of vascular BM with the formation of specific cellular micro-domains known as podosomes and invadopodia. These structures are specialized cell-matrix contacts with an inherent ability to degrade the extracellular matrix. Specifically, the formation of podosomes or invadopodia was shown as an important step in vascular sprouting and tumor cell extravasation, respectively. Here, we review and comment on these recent findings and explore the functions of podosomes and invadopodia within the context of pathological processes such as tumor dissemination and tumor angiogenesis.
Topics: Angiogenic Proteins; Animals; Basement Membrane; Blood Vessels; Cell Movement; Extracellular Matrix Proteins; Humans; Neoplasm Invasiveness; Neoplasms; Neovascularization, Pathologic; Podosomes
PubMed: 25789660
DOI: 10.1080/15384101.2015.1026523 -
Cellular and Molecular Life Sciences :... Oct 2018Osteoclasts are multinucleated cells responsible for bone resorption. Osteoclasts adhere to the bone surface through integrins and polarize to form actin rings, which... (Review)
Review
Osteoclasts are multinucleated cells responsible for bone resorption. Osteoclasts adhere to the bone surface through integrins and polarize to form actin rings, which are formed by the assembly of podosomes. The area contained within actin rings (also called sealing zones) has an acidic pH, which causes dissolution of bone minerals including hydroxyapatite and the degradation of matrix proteins including type I collagen by the protease cathepsin K. Osteoclasts resorb bone matrices while moving on bone surfaces. Osteoclasts change their cell shapes and exhibit three modes for bone resorption: motile resorbing mode for digging trenches, static resorbing mode for digging pits, and motile non-resorbing mode. Therefore, the actin cytoskeleton is actively remodeled in osteoclasts. Recent studies have revealed that many molecules, such as Rac, Cdc42, Rho, and small GTPase regulators and effectors, are involved in actin cytoskeletal remodeling during the formation of actin rings and resorption cavities on bone slices. In this review, we introduce how these molecules and non-canonical Wnt signaling regulate the bone-resorbing activity of osteoclasts.
Topics: Animals; Bone Resorption; Cytoskeleton; Humans; Osteoclasts; Podosomes; Wnt Signaling Pathway; cdc42 GTP-Binding Protein; rac GTP-Binding Proteins; rho GTP-Binding Proteins
PubMed: 30051162
DOI: 10.1007/s00018-018-2881-1 -
International Journal of Molecular... Jan 2019Arf GTPase-activating proteins (Arf GAPs) control the activity of ADP-ribosylation factors (Arfs) by inducing GTP hydrolysis and participate in a diverse array of... (Review)
Review
Arf GTPase-activating proteins (Arf GAPs) control the activity of ADP-ribosylation factors (Arfs) by inducing GTP hydrolysis and participate in a diverse array of cellular functions both through mechanisms that are dependent on and independent of their Arf GAP activity. A number of these functions hinge on the remodeling of actin filaments. Accordingly, some of the effects exerted by Arf GAPs involve proteins known to engage in regulation of the actin dynamics and architecture, such as Rho family proteins and nonmuscle myosin 2. Circular dorsal ruffles (CDRs), podosomes, invadopodia, lamellipodia, stress fibers and focal adhesions are among the actin-based structures regulated by Arf GAPs. Arf GAPs are thus important actors in broad functions like adhesion and motility, as well as the specialized functions of bone resorption, neurite outgrowth, and pathogen internalization by immune cells. Arf GAPs, with their multiple protein-protein interactions, membrane-binding domains and sites for post-translational modification, are good candidates for linking the changes in actin to the membrane. The findings discussed depict a family of proteins with a critical role in regulating actin dynamics to enable proper cell function.
Topics: ADP-Ribosylation Factors; Actin Cytoskeleton; Actins; Animals; Apoptosis; Cell Movement; Focal Adhesions; GTPase-Activating Proteins; Host-Pathogen Interactions; Humans; Multigene Family; Neuronal Outgrowth; Neurons; Podosomes; Protein Binding; Pseudopodia; Structure-Activity Relationship; rho GTP-Binding Proteins
PubMed: 30669557
DOI: 10.3390/ijms20020442