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Current Biology : CB Apr 2018Caveolae are one of the most abundant and striking features of the plasma membrane of many mammalian cell types. These surface pits have fascinated biologists since... (Review)
Review
Caveolae are one of the most abundant and striking features of the plasma membrane of many mammalian cell types. These surface pits have fascinated biologists since their discovery by the pioneers of electron microscopy in the middle of the last century, but we are only just starting to understand their multiple functions. Molecular understanding of caveolar formation is advancing rapidly and we now know that sculpting the membrane to generate the characteristic bulb-shaped caveolar pit involves the coordinated action of integral membrane proteins and peripheral membrane coat proteins in a process dependent on their multiple interactions with membrane lipids. The resulting structure is further stabilised by protein complexes at the caveolar neck. Caveolae can bud to generate an endocytic carrier but can also be disassembled in response to specific stimuli to function as a mechanoprotective device. These structures have also been linked to numerous signalling pathways. Here, we will briefly summarise the current molecular and structural understanding of caveolar formation and dynamics, discuss how the crucial structural components of caveolae work together to generate a dynamic sensing domain, and discuss the implications of recent studies on the diverse roles proposed for caveolae in different cells and tissues.
Topics: Animals; Caveolae; Caveolins; Cell Membrane; Cell Membrane Structures; Humans; Mammals; Membrane Lipids; Membrane Proteins; Signal Transduction
PubMed: 29689223
DOI: 10.1016/j.cub.2017.11.075 -
Current Opinion in Virology Feb 2022Endocytosis is used by eukaryotic cells for ingesting external objects. Importantly, endocytosis is a major process that determines phage pharmacokinetics in vivo.... (Review)
Review
Endocytosis is used by eukaryotic cells for ingesting external objects. Importantly, endocytosis is a major process that determines phage pharmacokinetics in vivo. Either dissemination of phages throughout the system or phage clearance engages cellular uptake of phage particles. Here we discuss phage uptake by mammalian cells, focusing on mechanisms and pathways involved. Of note, cellular uptake of phage virions was first observed in professional phagocytes, such as macrophages or granulocytes. For this reason, it was historically referred to as 'phagocytosis'. The modern definition of phagocytosis, however, identifies this process as a type of endocytosis within a larger repertoire of endocytic pathways, such as macropinocytosis, clathrin-mediated endocytosis, and caveolar endocytosis, which have all been included in the scope of this review.
Topics: Animals; Bacteriophages; Caveolae; Endocytosis; Mammals; Phagocytosis; Pinocytosis
PubMed: 34968792
DOI: 10.1016/j.coviro.2021.12.009 -
ELife Jun 2023Ring-like structures made up of caveolae appear to drive the development of membrane invaginations called T-tubules which are important for muscle contraction.
Ring-like structures made up of caveolae appear to drive the development of membrane invaginations called T-tubules which are important for muscle contraction.
Topics: Caveolin 1; Caveolae; Endocytosis
PubMed: 37339063
DOI: 10.7554/eLife.88954 -
Neuron May 2017The blood-brain barrier (BBB) provides a constant homeostatic brain environment that is essential for proper neural function. An unusually low rate of vesicular...
The blood-brain barrier (BBB) provides a constant homeostatic brain environment that is essential for proper neural function. An unusually low rate of vesicular transport (transcytosis) has been identified as one of the two unique properties of CNS endothelial cells, relative to peripheral endothelial cells, that maintain the restrictive quality of the BBB. However, it is not known how this low rate of transcytosis is achieved. Here we provide a mechanism whereby the regulation of CNS endothelial cell lipid composition specifically inhibits the caveolae-mediated transcytotic route readily used in the periphery. An unbiased lipidomic analysis reveals significant differences in endothelial cell lipid signatures from the CNS and periphery, which underlie a suppression of caveolae vesicle formation and trafficking in brain endothelial cells. Furthermore, lipids transported by Mfsd2a establish a unique lipid environment that inhibits caveolae vesicle formation in CNS endothelial cells to suppress transcytosis and ensure BBB integrity.
Topics: Animals; Blood-Brain Barrier; Blotting, Western; Caveolae; Endothelial Cells; HEK293 Cells; Humans; Immunohistochemistry; Lipid Metabolism; Membrane Transport Proteins; Mice; Mice, Knockout; Microscopy, Confocal; Microscopy, Electron, Transmission; Permeability; Symporters; Transcytosis
PubMed: 28416077
DOI: 10.1016/j.neuron.2017.03.043 -
Comprehensive Physiology Mar 2020Transcytosis of macromolecules through lung endothelial cells is the primary route of transport from the vascular compartment into the interstitial space. Endothelial... (Review)
Review
Transcytosis of macromolecules through lung endothelial cells is the primary route of transport from the vascular compartment into the interstitial space. Endothelial transcytosis is mostly a caveolae-dependent process that combines receptor-mediated endocytosis, vesicle trafficking via actin-cytoskeletal remodeling, and SNARE protein directed vesicle fusion and exocytosis. Herein, we review the current literature on caveolae-mediated endocytosis, the role of actin cytoskeleton in caveolae stabilization at the plasma membrane, actin remodeling during vesicle trafficking, and exocytosis of caveolar vesicles. Next, we provide a concise summary of experimental methods employed to assess transcytosis. Finally, we review evidence that transcytosis contributes to the pathogenesis of acute lung injury. © 2020 American Physiological Society. Compr Physiol 10:491-508, 2020.
Topics: Actin Cytoskeleton; Animals; Biological Transport; Capillary Permeability; Caveolae; Endothelial Cells; Humans; Lung; Transcytosis
PubMed: 32163197
DOI: 10.1002/cphy.c190012 -
Progress in Retinal and Eye Research Nov 2022Caveolae, specialized plasma membrane invaginations present in most cell types, play important roles in multiple cellular processes including cell signaling, lipid... (Review)
Review
Caveolae, specialized plasma membrane invaginations present in most cell types, play important roles in multiple cellular processes including cell signaling, lipid uptake and metabolism, endocytosis and mechanotransduction. They are found in almost all cell types but most abundant in endothelial cells, adipocytes and fibroblasts. Caveolin-1 (Cav1), the signature structural protein of caveolae was the first protein associated with caveolae, and in association with Cavin1/PTRF is required for caveolae formation. Genetic ablation of either Cav1 or Cavin1/PTRF downregulates expression of the other resulting in loss of caveolae. Studies using Cav1-deficient mouse models have implicated caveolae with human diseases such as cardiomyopathies, lipodystrophies, diabetes and muscular dystrophies. While caveolins and caveolae are extensively studied in extra-ocular settings, their contributions to ocular function and disease pathogenesis are just beginning to be appreciated. Several putative caveolin/caveolae functions are relevant to the eye and Cav1 is highly expressed in retinal vascular and choroidal endothelium, Müller glia, the retinal pigment epithelium (RPE), and the Schlemm's canal endothelium and trabecular meshwork cells. Variants at the CAV1/2 gene locus are associated with risk of primary open angle glaucoma and the high risk HTRA1 variant for age-related macular degeneration is thought to exert its effect through regulation of Cav1 expression. Caveolins also play important roles in modulating retinal neuroinflammation and blood retinal barrier permeability. In this article, we describe the current state of caveolin/caveolae research in the context of ocular function and pathophysiology. Finally, we discuss new evidence showing that retinal Cav1 exists and functions outside caveolae.
Topics: Mice; Animals; Humans; Caveolae; Caveolin 1; Mechanotransduction, Cellular; Endothelial Cells; Glaucoma, Open-Angle; Homeostasis; High-Temperature Requirement A Serine Peptidase 1
PubMed: 35729002
DOI: 10.1016/j.preteyeres.2022.101094 -
Cytometry. Part a : the Journal of the... Jul 2008The evolutionarily developed microdomain structure of biological membranes has gained more and more attention in the past decade. The caveolin-free "membrane rafts," the... (Review)
Review
The evolutionarily developed microdomain structure of biological membranes has gained more and more attention in the past decade. The caveolin-free "membrane rafts," the caveolin-expressing rafts (caveolae), as well as other membrane microdomains seem to play an essential role in controlling and coordinating cell-surface molecular recognition, internalization/endocytosis of the bound molecules or pathogenic organisms and in regulation of transmembrane signal transduction processes. Therefore, in many research fields (e.g. neurobiology and immunology), there is an ongoing need to understand the nature of these microdomains and to quantitatively characterize their lipid and protein composition under various physiological and pathological conditions. Flow and image cytometry offer many sophisticated and routine tools to study these questions. In this review, we give an overview of the past efforts to detect and characterize these membrane microdomains by the use of classical cytometric technologies, and finally we will discuss the results and perspectives of a new line of raft cytometry, the "high throughput screening assays of membrane microdomains," based on "lipidomic" and "proteomic" approaches.
Topics: Animals; Caveolae; Cell Membrane; Detergents; Flow Cytometry; Fluorescence Resonance Energy Transfer; Humans; Image Cytometry; Lipids; Membrane Lipids; Membrane Microdomains; Protein Structure, Tertiary; Proteomics
PubMed: 18473380
DOI: 10.1002/cyto.a.20572 -
International Journal of Molecular... Mar 2023The main component of blood and lymphatic vessels is the endothelium covering their luminal surface. It plays a significant role in many cardiovascular diseases.... (Review)
Review
The main component of blood and lymphatic vessels is the endothelium covering their luminal surface. It plays a significant role in many cardiovascular diseases. Tremendous progress has been made in deciphering of molecular mechanisms involved into intracellular transport. However, molecular machines are mostly characterized in vitro. It is important to adapt this knowledge to the situation existing in tissues and organs. Moreover, contradictions have accumulated within the field related to the function of endothelial cells (ECs) and their trans-endothelial pathways. This has induced necessity for the re-evaluation of several mechanisms related to the function of vascular ECs and intracellular transport and transcytosis there. Here, we analyze available data related to intracellular transport within ECs and re-examine several hypotheses about the role of different mechanisms in transcytosis across ECs. We propose a new classification of vascular endothelium and hypotheses related to the functional role of caveolae and mechanisms of lipid transport through ECs.
Topics: Endothelial Cells; Biological Transport; Transcytosis; Caveolae; Intracellular Membranes; Endothelium, Vascular
PubMed: 36982865
DOI: 10.3390/ijms24065791 -
Biochemical Society Transactions Feb 2020Multiple intra-cellular signalling pathways rely on calcium and 3'-5' cyclic adenosine monophosphate (cAMP) to act as secondary messengers. This is especially true in... (Review)
Review
Multiple intra-cellular signalling pathways rely on calcium and 3'-5' cyclic adenosine monophosphate (cAMP) to act as secondary messengers. This is especially true in cardiomyocytes which act as the force-producing units of the cardiac muscle and are required to react rapidly to environmental stimuli. The specificity of functional responses within cardiomyocytes and other cell types is produced by the organellar compartmentation of both calcium and cAMP. In this review, we assess the role of molecular localisation and relative contribution of active and passive processes in producing compartmentation. Active processes comprise the creation and destruction of signals, whereas passive processes comprise the release or sequestration of signals. Cardiomyocytes display a highly articulated membrane structure which displays significant cell-to-cell variability. Special attention is paid to the way in which cell membrane caveolae and the transverse-axial tubule system allow molecular localisation. We explore the effects of cell maturation, pathology and regional differences in the organisation of these processes. The subject of signal compartmentation has had a significant amount of attention within the cardiovascular field and has undergone a revolution over the past two decades. Advances in the area have been driven by molecular imaging using fluorescent dyes and genetically encoded constructs based upon fluorescent proteins. We also explore the use of scanning probe microscopy in the area. These techniques allow the analysis of molecular compartmentation within specific organellar compartments which gives researchers an entirely new perspective.
Topics: Animals; Calcium Signaling; Caveolae; Cell Compartmentation; Cyclic AMP; Fluorescence Resonance Energy Transfer; Heart Failure; Myocytes, Cardiac; Signal Transduction
PubMed: 32104883
DOI: 10.1042/BST20190247 -
A mechanosensitive caveolae-invadosome interplay drives matrix remodelling for cancer cell invasion.Nature Cell Biology Dec 2023Invadosomes and caveolae are mechanosensitive structures that are implicated in metastasis. Here, we describe a unique juxtaposition of caveola clusters and matrix...
Invadosomes and caveolae are mechanosensitive structures that are implicated in metastasis. Here, we describe a unique juxtaposition of caveola clusters and matrix degradative invadosomes at contact sites between the plasma membrane of cancer cells and constricting fibrils both in 2D and 3D type I collagen matrix environments. Preferential association between caveolae and straight segments of the fibrils, and between invadosomes and bent segments of the fibrils, was observed along with matrix remodelling. Caveola recruitment precedes and is required for invadosome formation and activity. Reciprocally, invadosome disruption results in the accumulation of fibril-associated caveolae. Moreover, caveolae and the collagen receptor β1 integrin co-localize at contact sites with the fibrils, and integrins control caveola recruitment to fibrils. In turn, caveolae mediate the clearance of β1 integrin and collagen uptake in an invadosome-dependent and collagen-cleavage-dependent mechanism. Our data reveal a reciprocal interplay between caveolae and invadosomes that coordinates adhesion to and proteolytic remodelling of confining fibrils to support tumour cell dissemination.
Topics: Humans; Podosomes; Extracellular Matrix; Caveolae; Integrin beta1; Collagen Type I; Neoplasm Invasiveness
PubMed: 37903910
DOI: 10.1038/s41556-023-01272-z