1
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Sugiyama MG, Brown AI, Vega-Lugo J, Borges JP, Scott AM, Jaqaman K, Fairn GD, Antonescu CN. Confinement of unliganded EGFR by tetraspanin nanodomains gates EGFR ligand binding and signaling. Nat Commun 2023; 14:2681. [PMID: 37160944 PMCID: PMC10170156 DOI: 10.1038/s41467-023-38390-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 04/28/2023] [Indexed: 05/11/2023] Open
Abstract
The epidermal growth factor receptor (EGFR) is a central regulator of cell physiology. EGFR is activated by ligand binding, triggering receptor dimerization, activation of kinase activity, and intracellular signaling. EGFR is transiently confined within various plasma membrane nanodomains, yet how this may contribute to regulation of EGFR ligand binding is poorly understood. To resolve how EGFR nanoscale compartmentalization gates ligand binding, we developed single-particle tracking methods to track the mobility of ligand-bound and total EGFR, in combination with modeling of EGFR ligand binding. In comparison to unliganded EGFR, ligand-bound EGFR is more confined and distinctly regulated by clathrin and tetraspanin nanodomains. Ligand binding to unliganded EGFR occurs preferentially in tetraspanin nanodomains, and disruption of tetraspanin nanodomains impairs EGFR ligand binding and alters the conformation of the receptor's ectodomain. We thus reveal a mechanism by which EGFR confinement within tetraspanin nanodomains regulates receptor signaling at the level of ligand binding.
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Affiliation(s)
- Michael G Sugiyama
- Department of Chemistry and Biology, Toronto Metropolitan University, Toronto, ON, Canada
| | - Aidan I Brown
- Department of Physics, Toronto Metropolitan University, Toronto, ON, Canada
| | - Jesus Vega-Lugo
- Department of Biophysics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Jazlyn P Borges
- Program in Neuroscience and Mental Health, Hospital for Sick Children, Toronto, ON, Canada
| | - Andrew M Scott
- Olivia Newton-John Cancer Research Institute, La Trobe University, Melbourne, VIC, Australia
| | - Khuloud Jaqaman
- Department of Biophysics, UT Southwestern Medical Center, Dallas, TX, USA
- Lyda Hill Department of Bioinformatics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Gregory D Fairn
- Department of Pathology, Dalhousie University, Halifax, NS, Canada
| | - Costin N Antonescu
- Department of Chemistry and Biology, Toronto Metropolitan University, Toronto, ON, Canada.
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2
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Mavri M, Glišić S, Senćanski M, Vrecl M, Rosenkilde MM, Spiess K, Kubale V. Patterns of human and porcine gammaherpesvirus-encoded BILF1 receptor endocytosis. Cell Mol Biol Lett 2023; 28:14. [PMID: 36810008 PMCID: PMC9942385 DOI: 10.1186/s11658-023-00427-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 01/30/2023] [Indexed: 02/23/2023] Open
Abstract
BACKGROUND The viral G-protein-coupled receptor (vGPCR) BILF1 encoded by the Epstein-Barr virus (EBV) is an oncogene and immunoevasin and can downregulate MHC-I molecules at the surface of infected cells. MHC-I downregulation, which presumably occurs through co-internalization with EBV-BILF1, is preserved among BILF1 receptors, including the three BILF1 orthologs encoded by porcine lymphotropic herpesviruses (PLHV BILFs). This study aimed to understand the detailed mechanisms of BILF1 receptor constitutive internalization, to explore the translational potential of PLHV BILFs compared with EBV-BILF1. METHODS A novel real-time fluorescence resonance energy transfer (FRET)-based internalization assay combined with dominant-negative variants of dynamin-1 (Dyn K44A) and the chemical clathrin inhibitor Pitstop2 in HEK-293A cells was used to study the effect of specific endocytic proteins on BILF1 internalization. Bioluminescence resonance energy transfer (BRET)-saturation analysis was used to study BILF1 receptor interaction with β-arrestin2 and Rab7. In addition, a bioinformatics approach informational spectrum method (ISM) was used to investigate the interaction affinity of BILF1 receptors with β-arrestin2, AP-2, and caveolin-1. RESULTS We identified dynamin-dependent, clathrin-mediated constitutive endocytosis for all BILF1 receptors. The observed interaction affinity between BILF1 receptors and caveolin-1 and the decreased internalization in the presence of a dominant-negative variant of caveolin-1 (Cav S80E) indicated the involvement of caveolin-1 in BILF1 trafficking. Furthermore, after BILF1 internalization from the plasma membrane, both the recycling and degradation pathways are proposed for BILF1 receptors. CONCLUSIONS The similarity in the internalization mechanisms observed for EBV-BILF1 and PLHV1-2 BILF1 provide a foundation for further studies exploring a possible translational potential for PLHVs, as proposed previously, and provides new information about receptor trafficking.
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Affiliation(s)
- Maša Mavri
- Institute for preclinical sciences, Veterinary Faculty, Ljubljana, Slovenia
| | - Sanja Glišić
- Center for Multidisciplinary Research, Institute of Nuclear Sciences VINCA, University of Belgrade, Belgrade, Serbia
| | - Milan Senćanski
- Center for Multidisciplinary Research, Institute of Nuclear Sciences VINCA, University of Belgrade, Belgrade, Serbia
| | - Milka Vrecl
- Institute for preclinical sciences, Veterinary Faculty, Ljubljana, Slovenia
| | - Mette M Rosenkilde
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Katja Spiess
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Virus and Microbiological Special Diagnostics, Statens Serum Institute, Copenhagen, Denmark
| | - Valentina Kubale
- Institute for preclinical sciences, Veterinary Faculty, Ljubljana, Slovenia.
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3
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Larsson E, Morén B, McMahon KA, Parton RG, Lundmark R. Dynamin2 functions as an accessory protein to reduce the rate of caveola internalization. J Cell Biol 2023; 222:213853. [PMID: 36729022 PMCID: PMC9929934 DOI: 10.1083/jcb.202205122] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 11/14/2022] [Accepted: 01/10/2023] [Indexed: 02/03/2023] Open
Abstract
Caveolae are small membrane invaginations that generally are stably attached to the plasma membrane. Their release is believed to depend on the GTPase dynamin 2 (Dyn2), in analogy with its role in fission of clathrin-coated vesicles. The mechanistic understanding of caveola fission is, however, sparse. Here, we used microscopy-based tracking of individual caveolae in living cells to determine the role of Dyn2 in caveola dynamics. We report that Dyn2 stably associated with the bulb of a subset of caveolae, but was not required for formation or fission of caveolae. Dyn2-positive caveolae displayed longer plasma membrane duration times, whereas depletion of Dyn2 resulted in shorter duration times and increased caveola fission. The stabilizing role of Dyn2 was independent of its GTPase activity and the caveola stabilizing protein EHD2. Thus, we propose that, in contrast to the current view, Dyn2 is not a core component of the caveolae machinery, but rather functions as an accessory protein that restrains caveola internalization.
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Affiliation(s)
- Elin Larsson
- https://ror.org/05kb8h459Integrative Medical Biology, Umeå University, Umeå, Sweden,Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
| | - Björn Morén
- https://ror.org/05kb8h459Integrative Medical Biology, Umeå University, Umeå, Sweden,Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
| | - Kerrie-Ann McMahon
- https://ror.org/00rqy9422Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Robert G. Parton
- https://ror.org/00rqy9422Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia,Centre for Microscopy and Microanalysis, The University of Queensland, Brisbane, Queensland, Australia
| | - Richard Lundmark
- https://ror.org/05kb8h459Integrative Medical Biology, Umeå University, Umeå, Sweden,Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden,Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden,Correspondence to Richard Lundmark:
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4
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Zhang Q, Zhu H, Cui Z, Li Y, Zhuo J, Ye J, Zhang Z, Lian Z, Du Q, Zhao KN, Zhang L, Jiang P. The HPV16E7 Affibody as a Novel Potential Therapeutic Agent for Treating Cervical Cancer Is Likely Internalized through Dynamin and Caveolin-1 Dependent Endocytosis. Biomolecules 2022; 12:biom12081114. [PMID: 36009008 PMCID: PMC9405713 DOI: 10.3390/biom12081114] [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: 06/16/2022] [Revised: 07/14/2022] [Accepted: 07/21/2022] [Indexed: 12/24/2022] Open
Abstract
Affibodies targeting intracellular proteins have a great potential to function as ideal therapeutic agents. However, little is known about how the affibodies enter target cells to interact with intracellular target proteins. We have previously developed the HPV16E7 affibody (ZHPV16E7384) for HPV16 positive cervical cancer treatment. Here, we explored the underlying mechanisms of ZHPV16E7384 and found that ZHPV16E7384 significantly inhibited the proliferation of target cells and induced a G1/S phase cell cycle arrest. Furthermore, ZHPV16E7384 treatment resulted in the upregulation of retinoblastoma protein (Rb) and downregulation of phosphorylated Rb (pRb), E2F1, cyclin D1, and CDK4 in the target cells. Moreover, treatment with dynamin or the caveolin-1 inhibitor not only significantly suppressed the internalization of ZHPV16E7384 into target cells but also reversed the regulation of cell cycle factors by ZHPV16E7384. Overall, these results indicate that ZHPV16E7384 was likely internalized specifically into target cells through dynamin- and caveolin-1 mediated endocytosis. ZHPV16E7384 induced the cell cycle arrest in the G1/S phase at least partially by interrupting HPV16E7 binding to and degrading Rb, subsequently leading to the downregulation of E2F1, cyclin D1, CDK4, and pRb, which ultimately inhibited target cell proliferation. These findings provide a rationale of using ZHPV16E7384 to conduct a clinical trial for target therapy in cervical cancer.
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Affiliation(s)
- Qingyuan Zhang
- Institute of Molecular Virology and Immunology, Department of Microbiology & Immunology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou 325035, China
| | - Hua Zhu
- Department of Gynecology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325035, China
| | - Zhouying Cui
- Institute of Molecular Virology and Immunology, Department of Microbiology & Immunology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou 325035, China
| | - Yuxiao Li
- Institute of Molecular Virology and Immunology, Department of Microbiology & Immunology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou 325035, China
| | - Jiaying Zhuo
- Institute of Molecular Virology and Immunology, Department of Microbiology & Immunology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou 325035, China
| | - Jingwei Ye
- Institute of Molecular Virology and Immunology, Department of Microbiology & Immunology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou 325035, China
| | - Zhihui Zhang
- Institute of Molecular Virology and Immunology, Department of Microbiology & Immunology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou 325035, China
| | - Zheng Lian
- Institute of Molecular Virology and Immunology, Department of Microbiology & Immunology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou 325035, China
| | - Qianqian Du
- Institute of Molecular Virology and Immunology, Department of Microbiology & Immunology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou 325035, China
| | - Kong-Nan Zhao
- Institute of Molecular Virology and Immunology, Department of Microbiology & Immunology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou 325035, China
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia 4067, Australia
- Correspondence: (K.-N.Z.); (L.Z.); (P.J.); Tel.: +61-7-34431291 (K.-N.Z.); +86-577-86689910 (L.Z.); +86-577-86699583 (P.J.)
| | - Lifang Zhang
- Institute of Molecular Virology and Immunology, Department of Microbiology & Immunology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou 325035, China
- Correspondence: (K.-N.Z.); (L.Z.); (P.J.); Tel.: +61-7-34431291 (K.-N.Z.); +86-577-86689910 (L.Z.); +86-577-86699583 (P.J.)
| | - Pengfei Jiang
- Institute of Molecular Virology and Immunology, Department of Microbiology & Immunology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou 325035, China
- Correspondence: (K.-N.Z.); (L.Z.); (P.J.); Tel.: +61-7-34431291 (K.-N.Z.); +86-577-86689910 (L.Z.); +86-577-86699583 (P.J.)
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5
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Cesar-Silva D, Pereira-Dutra FS, Moraes Giannini AL, Jacques G. de Almeida C. The Endolysosomal System: The Acid Test for SARS-CoV-2. Int J Mol Sci 2022; 23:ijms23094576. [PMID: 35562967 PMCID: PMC9105036 DOI: 10.3390/ijms23094576] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 01/13/2022] [Accepted: 01/17/2022] [Indexed: 12/16/2022] Open
Abstract
This review aims to describe and discuss the different functions of the endolysosomal system, from homeostasis to its vital role during viral infections. We will initially describe endolysosomal system's main functions, presenting recent data on how its compartments are essential for host defense to explore later how SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) and other coronaviruses subvert these organelles for their benefit. It is clear that to succeed, pathogens' evolution favored the establishment of ways to avoid, escape, or manipulate lysosomal function. The unavoidable coexistence with such an unfriendly milieu imposed on viruses the establishment of a vast array of strategies to make the most out of the invaded cell's machinery to produce new viruses and maneuvers to escape the host's defense system.
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Affiliation(s)
- Daniella Cesar-Silva
- Laboratory of Immunopharmacology, Oswaldo Cruz Institute, Fundação Oswaldo Cruz, Rio de Janeiro 21040-900, Brazil; (D.C.-S.); (F.S.P.-D.)
| | - Filipe S. Pereira-Dutra
- Laboratory of Immunopharmacology, Oswaldo Cruz Institute, Fundação Oswaldo Cruz, Rio de Janeiro 21040-900, Brazil; (D.C.-S.); (F.S.P.-D.)
| | - Ana Lucia Moraes Giannini
- Laboratory of Functional Genomics and Signal Transduction, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, Brazil;
| | - Cecília Jacques G. de Almeida
- Laboratory of Immunopharmacology, Oswaldo Cruz Institute, Fundação Oswaldo Cruz, Rio de Janeiro 21040-900, Brazil; (D.C.-S.); (F.S.P.-D.)
- Correspondence: or
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6
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Zingl FG, Thapa HB, Scharf M, Kohl P, Müller AM, Schild S. Outer Membrane Vesicles of Vibrio cholerae Protect and Deliver Active Cholera Toxin to Host Cells via Porin-Dependent Uptake. mBio 2021; 12:e0053421. [PMID: 34076466 PMCID: PMC8262896 DOI: 10.1128/mbio.00534-21] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 04/12/2021] [Indexed: 11/20/2022] Open
Abstract
Outer membrane vesicles (OMVs) are an emerging research field due to their multifactorial composition and involvement in interspecies and intraspecies communication. Recent studies indicate that vesicle release by Gram-negative bacterial pathogens is increased during in vivo colonization, as exemplified by the facultative human pathogen Vibrio cholerae upon oral ingestion by the host. In this study, we investigate the fate of OMVs produced by the Gram-negative facultative pathogen V. cholerae. We show that vesicles produced by the clinically relevant El Tor biotype are readily taken up by human intestinal cell lines. We identify outer membrane porins of V. cholerae, i.e., OmpU and OmpT, as the required surface effectors on OMVs for cellular uptake, and we pinpoint the uptake mechanism as caveolin-mediated endocytosis. Furthermore, we show that OMVs derived from V. cholerae grown under virulence-inducing conditions act as potent vehicles for delivery of bioactive cholera toxin to intestinal epithelial cells. In contrast to free cholera toxin secreted via the type II secretion system, OMV-associated cholera toxin is protected from degradation by intestinal proteases. Taken together, these data show that OMV-associated cholera toxin can sustain longer periods in the intestinal tract and preserve toxin effects, as indicated by a prolonged increase of cAMP levels in the intestinal tissue. IMPORTANCE Cholera is still a massive global health burden because it causes large outbreaks with millions of infections and thousands of deaths every year. Several studies have contributed to the knowledge of this pathogen, although key parts are still missing. We aim to broaden our understanding of Vibrio cholerae infections, virulence, and toxicity by drawing attention to the involvement of OMVs in these core processes. Upon host entry, V. cholerae increases secretion of OMVs, which can carry the main virulence factor, cholera toxin, to distant host intestinal cells. We show that specific outer membrane porins on the vesicle surface mediate endocytosis of the vesicles into intestinal cells. With protection by the vesicles, cholera toxin activity endures even in the presence of intestinal proteases. It is tempting to hypothesize that the extended half-life of vesicle-associated cholera toxin allows it to target host cells distant from the primary colonization sites.
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Affiliation(s)
- Franz G. Zingl
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Himadri B. Thapa
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Martina Scharf
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Paul Kohl
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Anna M. Müller
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Stefan Schild
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
- BioTechMed Graz, Graz, Austria
- Field of Excellence Biohealth, University of Graz, Graz, Austria
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7
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Manzanares D, Pérez-Carrión MD, Jiménez Blanco JL, Ortiz Mellet C, García Fernández JM, Ceña V. Cyclodextrin-Based Nanostructure Efficiently Delivers siRNA to Glioblastoma Cells Preferentially via Macropinocytosis. Int J Mol Sci 2020; 21:ijms21239306. [PMID: 33291321 PMCID: PMC7731237 DOI: 10.3390/ijms21239306] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 11/30/2020] [Accepted: 12/03/2020] [Indexed: 12/25/2022] Open
Abstract
Small interfering ribonucleic acid (siRNA) has the potential to revolutionize therapeutics since it can knockdown very efficiently the target protein. It is starting to be widely used to interfere with cell infection by HIV. However, naked siRNAs are unable to get into the cell, requiring the use of carriers to protect them from degradation and transporting them across the cell membrane. There is no information about which is the most efficient endocytosis route for high siRNA transfection efficiency. One of the most promising carriers to efficiently deliver siRNA are cyclodextrin derivatives. We have used nanocomplexes composed of siRNA and a β-cyclodextrin derivative, AMC6, with a very high transfection efficiency to selectively knockdown clathrin heavy chain, caveolin 1, and p21 Activated Kinase 1 to specifically block clathrin-mediated, caveolin-mediated and macropinocytosis endocytic pathways. The main objective was to identify whether there is a preferential endocytic pathway associated with high siRNA transfection efficiency. We have found that macropinocytosis is the preferential entry pathway for the nanoparticle and its associated siRNA cargo. However, blockade of macropinocytosis does not affect AMC6-mediated transfection efficiency, suggesting that macropinocytosis blockade can be functionally compensated by an increase in clathrin- and caveolin-mediated endocytosis.
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Affiliation(s)
- Darío Manzanares
- Unidad Asociada Neurodeath, Universidad de Castilla-La Mancha, 02006 Albacete, Spain; (D.M.); (M.D.P.-C.)
- CIBERNED, Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - María Dolores Pérez-Carrión
- Unidad Asociada Neurodeath, Universidad de Castilla-La Mancha, 02006 Albacete, Spain; (D.M.); (M.D.P.-C.)
- CIBERNED, Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - José Luis Jiménez Blanco
- Departamento de Química Orgánica, Facultad de Química, Universidad de Sevilla, 41012 Sevilla, Spain; (J.L.J.B.); (C.O.M.)
| | - Carmen Ortiz Mellet
- Departamento de Química Orgánica, Facultad de Química, Universidad de Sevilla, 41012 Sevilla, Spain; (J.L.J.B.); (C.O.M.)
| | - José Manuel García Fernández
- Instituto de Investigaciones Químicas (IIQ), Consejo Superior de Investigaciones Científicas-Universidad de Sevilla, 41092 Sevilla, Spain,
| | - Valentín Ceña
- Unidad Asociada Neurodeath, Universidad de Castilla-La Mancha, 02006 Albacete, Spain; (D.M.); (M.D.P.-C.)
- CIBERNED, Instituto de Salud Carlos III, 28029 Madrid, Spain
- Correspondence:
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8
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Davis LC, Morgan AJ, Galione A. NAADP-regulated two-pore channels drive phagocytosis through endo-lysosomal Ca 2+ nanodomains, calcineurin and dynamin. EMBO J 2020; 39:e104058. [PMID: 32510172 PMCID: PMC7360967 DOI: 10.15252/embj.2019104058] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 04/22/2020] [Accepted: 04/29/2020] [Indexed: 12/15/2022] Open
Abstract
Macrophages clear pathogens by phagocytosis and lysosomes that fuse with phagosomes are traditionally regarded as to a source of membranes and luminal degradative enzymes. Here, we reveal that endo-lysosomes act as platforms for a new phagocytic signalling pathway in which FcγR activation recruits the second messenger NAADP and thereby promotes the opening of Ca2+ -permeable two-pore channels (TPCs). Remarkably, phagocytosis is driven by these local endo-lysosomal Ca2+ nanodomains rather than global cytoplasmic or ER Ca2+ signals. Motile endolysosomes contact nascent phagosomes to promote phagocytosis, whereas endo-lysosome immobilization prevents it. We show that TPC-released Ca2+ rapidly activates calcineurin, which in turn dephosphorylates and activates the GTPase dynamin-2. Finally, we find that different endo-lysosomal Ca2+ channels play diverse roles, with TPCs providing a universal phagocytic signal for a wide range of particles and TRPML1 being only required for phagocytosis of large targets.
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Affiliation(s)
- Lianne C Davis
- Department of Pharmacology, University of Oxford, Oxford, UK
| | | | - Antony Galione
- Department of Pharmacology, University of Oxford, Oxford, UK
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9
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Francia V, Montizaan D, Salvati A. Interactions at the cell membrane and pathways of internalization of nano-sized materials for nanomedicine. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2020; 11:338-353. [PMID: 32117671 PMCID: PMC7034226 DOI: 10.3762/bjnano.11.25] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 01/27/2020] [Indexed: 05/17/2023]
Abstract
Nano-sized materials have great potential as drug carriers for nanomedicine applications. Thanks to their size, they can exploit the cellular machinery to enter cells and be trafficked intracellularly, thus they can be used to overcome some of the cellular barriers to drug delivery. Nano-sized drug carriers of very different properties can be prepared, and their surface can be modified by the addition of targeting moieties to recognize specific cells. However, it is still difficult to understand how the material properties affect the subsequent interactions and outcomes at cellular level. As a consequence of this, designing targeted drugs remains a major challenge in drug delivery. Within this context, we discuss the current understanding of the initial steps in the interactions of nano-sized materials with cells in relation to nanomedicine applications. In particular, we focus on the difficult interplay between the initial adhesion of nano-sized materials to the cell surface, the potential recognition by cell receptors, and the subsequent mechanisms cells use to internalize them. The factors affecting these initial events are discussed. Then, we briefly describe the different pathways of endocytosis in cells and illustrate with some examples the challenges in understanding how nanomaterial properties, such as size, charge, and shape, affect the mechanisms cells use for their internalization. Technical difficulties in characterizing these mechanisms are presented. A better understanding of the first interactions of nano-sized materials with cells will help to design nanomedicines with improved targeting.
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Affiliation(s)
- Valentina Francia
- Groningen Research Institute of Pharmacy, University of Groningen, 9713AV Groningen, Netherlands
| | - Daphne Montizaan
- Groningen Research Institute of Pharmacy, University of Groningen, 9713AV Groningen, Netherlands
| | - Anna Salvati
- Groningen Research Institute of Pharmacy, University of Groningen, 9713AV Groningen, Netherlands
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10
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Li M, Yan P, Liu Z, Cai D, Luo Y, Wu X, Wang Q, Huang Y, Wu Y. Muscovy duck reovirus enters susceptible cells via a caveolae-mediated endocytosis-like pathway. Virus Res 2019; 276:197806. [PMID: 31704247 DOI: 10.1016/j.virusres.2019.197806] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 10/21/2019] [Accepted: 11/04/2019] [Indexed: 01/27/2023]
Abstract
Muscovy duck reovirus (MDRV) causes immunosuppression and results in high mortality among Muscovy ducklings. Cell entry is the first step of virus infection and represents a potential therapeutic target. However, very little is known about the mechanism by which MDRV penetrates the cells. The aim of this study was to explore the mechanism of MDRV cell entry and subsequent infection. DF-1 and Vero cells were pretreated with the inhibitors chlorpromazine (CPZ), cytochalasin D, methyl-beta-cyclodextrin (M-β-CD), genistein, dynasore, nocodazole, or NH4Cl, and then infected with MDRV. The copy number of the MDRV p10.8 gene and the expression of viral sigma A protein were determined by RT-PCR and western blot, respectively. Both sigma A expression and p10.8 gene copy number were decreased by treatment with M-β-CD, genistein, dynasore, nocodazole, and NH4Cl. In contrast, no effects on virus infection were detected when inhibitors of clathrin-mediated endocytosis or macropinocytosis were used. In addition, the colocalization between MDRV sigma A protein and caveolin-1 was evaluated by double-label immunofluorescence. Collectively, our data revealed that MDRV can enter susceptible cells through caveolin-dependent endocytosis involving dynamin and microtubules. Moreover, the acidic environment of the endosomes was found to be critical for efficient infection. Our findings provide new insights into the infection process of MDRV.
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Affiliation(s)
- Minghui Li
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou 350002, People's Republic of China
| | - Ping Yan
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou 350002, People's Republic of China
| | - Zhenni Liu
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou 350002, People's Republic of China
| | - Dongling Cai
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou 350002, People's Republic of China
| | - Yu Luo
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou 350002, People's Republic of China
| | - Xiaoping Wu
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou 350002, People's Republic of China; Fujian Key Laboratory of Traditional Chinese Veterinary Medicine and Animal Health (Fujian Agricultural and Forestry University), Fuzhou 350002, People's Republic of China
| | - Quanxi Wang
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou 350002, People's Republic of China; Fujian Key Laboratory of Traditional Chinese Veterinary Medicine and Animal Health (Fujian Agricultural and Forestry University), Fuzhou 350002, People's Republic of China
| | - Yifan Huang
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou 350002, People's Republic of China; Fujian Key Laboratory of Traditional Chinese Veterinary Medicine and Animal Health (Fujian Agricultural and Forestry University), Fuzhou 350002, People's Republic of China
| | - Yijian Wu
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou 350002, People's Republic of China; Fujian Key Laboratory of Traditional Chinese Veterinary Medicine and Animal Health (Fujian Agricultural and Forestry University), Fuzhou 350002, People's Republic of China.
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11
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Francia V, Reker-Smit C, Boel G, Salvati A. Limits and challenges in using transport inhibitors to characterize how nano-sized drug carriers enter cells. Nanomedicine (Lond) 2019; 14:1533-1549. [PMID: 31208280 DOI: 10.2217/nnm-2018-0446] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Aim: In this work we illustrate limits and challenges associated with the use of pharmacological inhibitors to study how nanomedicines enter cells and show how such limits can be overcome. Materials & methods: We selected a panel of six common pharmacological inhibitors and a model nanoparticle-cell system. We tested eventual toxicity by measuring cell viability. We confirmed drug efficacy by measuring the uptake of control markers for the pathways involved by flow cytometry and fluorescence microscopy. Results & conclusion: We show how to optimize the use of pharmacological inhibitors and interpret the results generated. Furthermore, we demonstrate that some inhibitors cannot be used for nanomedicine studies because they lose their efficacy when serum is added, as required for nanoparticle exposure to cells.
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Affiliation(s)
- Valentina Francia
- Department of Pharmacokinetics, Toxicology & Targeting, Groningen Research Institute of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713AV Groningen, The Netherlands
| | - Catharina Reker-Smit
- Department of Pharmacokinetics, Toxicology & Targeting, Groningen Research Institute of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713AV Groningen, The Netherlands
| | - Guido Boel
- Department of Pharmacokinetics, Toxicology & Targeting, Groningen Research Institute of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713AV Groningen, The Netherlands
| | - Anna Salvati
- Department of Pharmacokinetics, Toxicology & Targeting, Groningen Research Institute of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713AV Groningen, The Netherlands
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12
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Ali T, Bednarska J, Vassilopoulos S, Tran M, Diakonov IA, Ziyadeh-Isleem A, Guicheney P, Gorelik J, Korchev YE, Reilly MM, Bitoun M, Shevchuk A. Correlative SICM-FCM reveals changes in morphology and kinetics of endocytic pits induced by disease-associated mutations in dynamin. FASEB J 2019; 33:8504-8518. [PMID: 31017801 PMCID: PMC6593877 DOI: 10.1096/fj.201802635r] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Dynamin 2 (DNM2) is a GTP-binding protein that controls endocytic vesicle scission and defines a whole class of dynamin-dependent endocytosis, including clathrin-mediated endocytosis by caveoli. It has been suggested that mutations in the DNM2 gene, associated with 3 inherited diseases, disrupt endocytosis. However, how exactly mutations affect the nanoscale morphology of endocytic machinery has never been studied. In this paper, we used live correlative scanning ion conductance microscopy (SICM) and fluorescence confocal microscopy (FCM) to study how disease-associated mutations affect the morphology and kinetics of clathrin-coated pits (CCPs) by directly following their dynamics of formation, maturation, and internalization in skin fibroblasts from patients with centronuclear myopathy (CNM) and in Cos-7 cells expressing corresponding dynamin mutants. Using SICM-FCM, which we have developed, we show how p.R465W mutation disrupts pit structure, preventing its maturation and internalization, and significantly increases the lifetime of CCPs. Differently, p.R522H slows down the formation of CCPs without affecting their internalization. We also found that CNM mutations in DNM2 affect the distribution of caveoli and reduce dorsal ruffling in human skin fibroblasts. Collectively, our SICM-FCM findings at single CCP level, backed up by electron microscopy data, argue for the impairment of several forms of endocytosis in DNM2-linked CNM.-Ali, T., Bednarska, J., Vassilopoulos, S., Tran, M., Diakonov, I. A., Ziyadeh-Isleem, A., Guicheney, P., Gorelik, J., Korchev, Y. E., Reilly, M. M., Bitoun, M., Shevchuk, A. Correlative SICM-FCM reveals changes in morphology and kinetics of endocytic pits induced by disease-associated mutations in dynamin.
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Affiliation(s)
- Tayyibah Ali
- Division of Experimental Medicine, Department of Medicine, Imperial College London, London, United Kingdom
| | - Joanna Bednarska
- Division of Experimental Medicine, Department of Medicine, Imperial College London, London, United Kingdom
| | - Stéphane Vassilopoulos
- Research Center for Myology, Institut de Myologie, UMRS 974, INSERM, Sorbonne Université, Paris, France
| | - Martin Tran
- Division of Experimental Medicine, Department of Medicine, Imperial College London, London, United Kingdom
| | - Ivan A Diakonov
- Department of Cardiac Medicine, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Azza Ziyadeh-Isleem
- UMRS 1166, INSERM, Institute of Cardiometabolism and Nutrition (ICAN), Paris, France.,UMRS 1166, Sorbonne Universités-Pierre and Marie Curie University (UPMC), Paris, France
| | - Pascale Guicheney
- UMRS 1166, INSERM, Institute of Cardiometabolism and Nutrition (ICAN), Paris, France.,UMRS 1166, Sorbonne Universités-Pierre and Marie Curie University (UPMC), Paris, France
| | - Julia Gorelik
- Department of Cardiac Medicine, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Yuri E Korchev
- Division of Experimental Medicine, Department of Medicine, Imperial College London, London, United Kingdom
| | - Mary M Reilly
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, Queen Square London, United Kingdom
| | - Marc Bitoun
- Research Center for Myology, Institut de Myologie, UMRS 974, INSERM, Sorbonne Université, Paris, France
| | - Andrew Shevchuk
- Division of Experimental Medicine, Department of Medicine, Imperial College London, London, United Kingdom
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13
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Verma DK, Gupta D, Lal SK. Host Lipid Rafts Play a Major Role in Binding and Endocytosis of Influenza A Virus. Viruses 2018; 10:v10110650. [PMID: 30453689 PMCID: PMC6266268 DOI: 10.3390/v10110650] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Revised: 10/08/2018] [Accepted: 10/13/2018] [Indexed: 12/14/2022] Open
Abstract
Influenza still remains one of the most challenging diseases, posing a significant threat to public health. Host lipid rafts play a critical role in influenza A virus (IAV) assembly and budding, however, their role in polyvalent IAV host binding and endocytosis had remained elusive until now. In the present study, we observed co-localization of IAV with a lipid raft marker ganglioside, GM1, on the host surface. Further, we isolated the lipid raft micro-domains from IAV infected cells and detected IAV protein in the raft fraction. Finally, raft disruption using Methyl-β-Cyclodextrin revealed significant reduction in IAV host binding, suggesting utilization of host rafts for polyvalent binding on the host cell surface. In addition to this, cyclodextrin mediated inhibition of raft-dependent endocytosis showed significantly reduced IAV internalization. Interestingly, exposure of cells to cyclodextrin two hours post-IAV binding showed no such reduction in IAV entry, indicating use of raft-dependent endocytosis for host entry. In summary, this study demonstrates that host lipid rafts are selected by IAV as a host attachment factors for multivalent binding, and IAV utilizes these micro-domains to exploit raft-dependent endocytosis for host internalization, a virus entry route previously unknown for IAV.
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Affiliation(s)
- Dileep Kumar Verma
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India.
| | - Dinesh Gupta
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India.
| | - Sunil Kumar Lal
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India.
- School of Science and Tropical Medicine & Biology Platform, Monash University, Malaysia, Bandar Sunway, Selangor, DE 47500, Malaysia.
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14
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Sandvig K, Kavaliauskiene S, Skotland T. Clathrin-independent endocytosis: an increasing degree of complexity. Histochem Cell Biol 2018; 150:107-118. [PMID: 29774430 PMCID: PMC6096564 DOI: 10.1007/s00418-018-1678-5] [Citation(s) in RCA: 106] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/04/2018] [Indexed: 11/03/2022]
Abstract
This article aims at providing an update on the complexity of clathrin-independent endocytosis. It is now almost 30 years since we first wrote a review about its existence; at that time many people believed that with the exception of macropinocytosis, which will only be briefly mentioned in this review, all uptake could be accounted for by clathrin-dependent endocytosis. Now it is generally accepted that there are different clathrin-independent mechanisms, some of them regulated by ligands and membrane lipid composition. They can be both dynamin-dependent and -independent, meaning that the uptake cannot be accounted for by caveolae and other dynamin-dependent processes such as tubular structures that can be induced by toxins, e.g. Shiga toxin, or the fast endophilin mediated endocytosis recently described. Caveolae seem to be mostly quite stable structures with other functions than endocytosis, but evidence suggests that they may have cell-type dependent functions. Although several groups have been working on endocytic mechanisms for years, and new advanced methods have improved our ability to study mechanistic details, there are still a number of important questions we need to address, such as: How many endocytic mechanisms does a cell have? How quantitatively important are they? What about the complexity in polarized cells where clathrin-independent endocytosis is differentially regulated on the apical and basolateral poles? These questions are not easy to answer since one and the same molecule may contribute to more than one process, and manipulating one mechanism can affect another. Also, several inhibitors of endocytic processes commonly used turn out to be less specific than originally thought. We will here describe the current view of clathrin-independent endocytic processes and the challenges in studying them.
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Affiliation(s)
- Kirsten Sandvig
- Department of Molecular Cell Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Montebello, 0379, Oslo, Norway.
- Department of Molecular Biosciences, University of Oslo, 0316, Oslo, Norway.
| | - Simona Kavaliauskiene
- Department of Molecular Cell Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Montebello, 0379, Oslo, Norway
| | - Tore Skotland
- Department of Molecular Cell Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Montebello, 0379, Oslo, Norway
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15
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Kabbani AM, Kelly CV. Nanoscale Membrane Budding Induced by CTxB and Detected via Polarized Localization Microscopy. Biophys J 2017; 113:1795-1806. [PMID: 29045873 DOI: 10.1016/j.bpj.2017.08.031] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 08/07/2017] [Accepted: 08/11/2017] [Indexed: 11/17/2022] Open
Abstract
For endocytosis and exocytosis, membranes transition among planar, budding, and vesicular topographies through nanoscale reorganization of lipids, proteins, and carbohydrates. However, prior attempts to understand the initial stages of nanoscale bending have been limited by experimental resolution. Through the implementation of polarized localization microscopy, this article reports the inherent membrane bending capability of cholera toxin subunit B (CTxB) in quasi-one-component-supported lipid bilayers. Membrane buds were first detected with <50 nm radius, grew to >200 nm radius, and extended into longer tubules with dependence on the membrane tension and CTxB concentration. Compared to the concentration of the planar-supported lipid bilayers, CTxB was (12 ± 4)× more concentrated on the positive curvature top and (26 ± 11)× more concentrated on the negative Gaussian curvature neck of the nanoscale membrane buds. CTxB is frequently used as a marker for liquid-ordered lipid phases; however, the coupling between CTxB and membrane bending provides an alternate understanding of CTxB-induced membrane reorganization. These findings allow for the reinterpretation of prior observations by correlating CTxB clustering and diffusion to CTxB-induced membrane bending. Single-particle tracking was performed on single lipids and CTxB to reveal the correlations among single-molecule diffusion, CTxB accumulation, and membrane topography. Slowed lipid and CTxB diffusion was observed at the nanoscale bud locations, suggesting a local increase in the effective membrane viscosity or molecular crowding upon membrane bending. These results suggest inherent CTxB-induced membrane bending as a mechanism for initiating CTxB internalization in cells that could be independent of clathrin, caveolin, actin, and lipid phase separation.
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Affiliation(s)
- Abir M Kabbani
- Department of Physics and Astronomy, Wayne State University, Detroit, Michigan
| | - Christopher V Kelly
- Department of Physics and Astronomy, Wayne State University, Detroit, Michigan.
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16
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de Almeida CJG. Caveolin-1 and Caveolin-2 Can Be Antagonistic Partners in Inflammation and Beyond. Front Immunol 2017; 8:1530. [PMID: 29250058 PMCID: PMC5715436 DOI: 10.3389/fimmu.2017.01530] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 10/27/2017] [Indexed: 12/26/2022] Open
Abstract
Caveolins, encoded by the CAV gene family, are the main protein components of caveolae. In most tissues, caveolin-1 (Cav-1) and caveolin-2 (Cav-2) are co-expressed, and Cav-2 targeting to caveolae depends on the formation of heterooligomers with Cav-1. Notwithstanding, Cav-2 has unpredictable activities, opposing Cav-1 in the regulation of some cellular processes. While the major roles of Cav-1 as a modulator of cell signaling in inflammatory processes and in immune responses have been extensively discussed elsewhere, the aim of this review is to focus on data revealing the distinct activity of Cav-1 and Cav-2, which suggest that these proteins act antagonistically to fine-tune a variety of cellular processes relevant to inflammation.
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17
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Lim JY, Barnett TC, Bastiani M, McMahon KA, Ferguson C, Webb RI, Parton RG, Walker MJ. Caveolin 1 restricts Group A Streptococcus invasion of nonphagocytic host cells. Cell Microbiol 2017; 19. [PMID: 28778116 DOI: 10.1111/cmi.12772] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 07/19/2017] [Accepted: 07/21/2017] [Indexed: 01/08/2023]
Abstract
Caveolae are composed of 2 major proteins, caveolin 1 (CAV1) and cavin 1 or polymerase transcript release factor I (CAVIN1). Here, we demonstrate that CAV1 levels modulate invasion of Group A Streptococcus (GAS) into nonphagocytic mammalian cells. GAS showed enhanced internalisation into CAV1-knockout mouse embryonic fibroblasts and CAV1 knockdown human epithelial HEp-2 cells, whereas overexpression of CAV1 in HEp-2 cells reduced GAS invasion. This effect was not dependent on the expression of the GAS fibronectin binding protein SfbI, which had previously been implicated in caveolae-mediated uptake. Nor was this effect dependent on CAVIN1, as knockout of CAVIN1 in mouse embryonic fibroblasts resulted in reduced GAS internalisation. Although CAV1 restricted GAS invasion into host cells, we observed only minimal association of invading GAS (strain M1T15448 ) with CAV1 by immunofluorescence and very low association of invading M1T15448 with caveolae by transmission electron microscopy. These observations suggest that physical interaction with caveolae is not needed for CAV1 restriction of invading GAS. An indirect mechanism of action is also consistent with the finding that changing membrane fluidity reverses the increased invasion observed in CAV1-null cells. Together, these results suggest that CAV1 protects host cells against GAS invasion by a caveola-independent mechanism.
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Affiliation(s)
- Jin Yan Lim
- Australian Infectious Diseases Research Centre and School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Timothy C Barnett
- Australian Infectious Diseases Research Centre and School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Michele Bastiani
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
| | - Kerrie-Ann McMahon
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
| | - Charles Ferguson
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia
| | - Richard I Webb
- Centre for Microscopy and Microanalysis, The University of Queensland, St Lucia, Queensland, Australia
| | - Robert G Parton
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland, Australia.,Centre for Microscopy and Microanalysis, The University of Queensland, St Lucia, Queensland, Australia
| | - Mark J Walker
- Australian Infectious Diseases Research Centre and School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
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18
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Spencer A, Yu L, Guili V, Reynaud F, Ding Y, Ma J, Jullien J, Koubi D, Gauthier E, Cluet D, Falk J, Castellani V, Yuan C, Rudkin BB. Nerve Growth Factor Signaling from Membrane Microdomains to the Nucleus: Differential Regulation by Caveolins. Int J Mol Sci 2017; 18:E693. [PMID: 28338624 PMCID: PMC5412279 DOI: 10.3390/ijms18040693] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 03/08/2017] [Accepted: 03/13/2017] [Indexed: 11/16/2022] Open
Abstract
Membrane microdomains or "lipid rafts" have emerged as essential functional modules of the cell, critical for the regulation of growth factor receptor-mediated responses. Herein we describe the dichotomy between caveolin-1 and caveolin-2, structural and regulatory components of microdomains, in modulating proliferation and differentiation. Caveolin-2 potentiates while caveolin-1 inhibits nerve growth factor (NGF) signaling and subsequent cell differentiation. Caveolin-2 does not appear to impair NGF receptor trafficking but elicits prolonged and stronger activation of MAPK (mitogen-activated protein kinase), Rsk2 (ribosomal protein S6 kinase 2), and CREB (cAMP response element binding protein). In contrast, caveolin-1 does not alter initiation of the NGF signaling pathway activation; rather, it acts, at least in part, by sequestering the cognate receptors, TrkA and p75NTR, at the plasma membrane, together with the phosphorylated form of the downstream effector Rsk2, which ultimately prevents CREB phosphorylation. The non-phosphorylatable caveolin-1 serine 80 mutant (S80V), no longer inhibits TrkA trafficking or subsequent CREB phosphorylation. MC192, a monoclonal antibody towards p75NTR that does not block NGF binding, prevents exit of both NGF receptors (TrkA and p75NTR) from lipid rafts. The results presented herein underline the role of caveolin and receptor signaling complex interplay in the context of neuronal development and tumorigenesis.
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MESH Headings
- Animals
- Antibodies, Monoclonal/immunology
- CREB-Binding Protein/metabolism
- Caveolin 1/antagonists & inhibitors
- Caveolin 1/genetics
- Caveolin 1/metabolism
- Caveolin 2/antagonists & inhibitors
- Caveolin 2/genetics
- Caveolin 2/metabolism
- Cell Differentiation/drug effects
- Cell Nucleus/metabolism
- Cells, Cultured
- Ganglia, Spinal/cytology
- Ganglia, Spinal/metabolism
- Membrane Microdomains/metabolism
- Mice
- Nerve Growth Factor/pharmacology
- Nerve Tissue Proteins
- PC12 Cells
- Phosphorylation/drug effects
- Protein Binding
- Protein Transport/drug effects
- RNA Interference
- RNA, Small Interfering/metabolism
- Rats
- Receptor, Nerve Growth Factor/metabolism
- Receptor, trkA/chemistry
- Receptor, trkA/immunology
- Receptor, trkA/metabolism
- Receptors, Growth Factor
- Receptors, Nerve Growth Factor/chemistry
- Receptors, Nerve Growth Factor/immunology
- Receptors, Nerve Growth Factor/metabolism
- Ribosomal Protein S6 Kinases, 90-kDa/metabolism
- Signal Transduction/drug effects
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Affiliation(s)
- Ambre Spencer
- East China Normal University, Key Laboratory of Brain Functional Genomics of the Ministry of Education of PR China, Joint Laboratory of Neuropathogenesis, ECNU, ENS Lyon, CNRS, Shanghai 200062, China.
- Univ. Lyon, Ecole normale supérieure de Lyon, Université Claude Bernard Lyon 1, CNRS, Differentiation & Cell Cycle Group, Laboratoire de Biologie Moléculaire de la Cellule, UMR5239, 69007 Lyon, France.
- East China Normal University, School of Life Sciences, Laboratory of Molecular and Cellular Neurophysiology, Shanghai 200062, China.
| | - Lingli Yu
- East China Normal University, Key Laboratory of Brain Functional Genomics of the Ministry of Education of PR China, Joint Laboratory of Neuropathogenesis, ECNU, ENS Lyon, CNRS, Shanghai 200062, China.
- Univ. Lyon, Ecole normale supérieure de Lyon, Université Claude Bernard Lyon 1, CNRS, Differentiation & Cell Cycle Group, Laboratoire de Biologie Moléculaire de la Cellule, UMR5239, 69007 Lyon, France.
- East China Normal University, School of Life Sciences, Laboratory of Molecular and Cellular Neurophysiology, Shanghai 200062, China.
| | - Vincent Guili
- Univ. Lyon, Ecole normale supérieure de Lyon, Université Claude Bernard Lyon 1, CNRS, Differentiation & Cell Cycle Group, Laboratoire de Biologie Moléculaire de la Cellule, UMR5239, 69007 Lyon, France.
| | - Florie Reynaud
- Univ. Lyon, Université Claude Bernard Lyon 1, CNRS, CGphiMC UMR5534, 69622 Villeurbanne Cedex, France.
| | - Yindi Ding
- East China Normal University, Key Laboratory of Brain Functional Genomics of the Ministry of Education of PR China, Joint Laboratory of Neuropathogenesis, ECNU, ENS Lyon, CNRS, Shanghai 200062, China.
- Univ. Lyon, Ecole normale supérieure de Lyon, Université Claude Bernard Lyon 1, CNRS, Differentiation & Cell Cycle Group, Laboratoire de Biologie Moléculaire de la Cellule, UMR5239, 69007 Lyon, France.
- East China Normal University, School of Life Sciences, Laboratory of Molecular and Cellular Neurophysiology, Shanghai 200062, China.
| | - Ji Ma
- East China Normal University, Key Laboratory of Brain Functional Genomics of the Ministry of Education of PR China, Joint Laboratory of Neuropathogenesis, ECNU, ENS Lyon, CNRS, Shanghai 200062, China.
- East China Normal University, School of Life Sciences, Laboratory of Molecular and Cellular Neurophysiology, Shanghai 200062, China.
| | - Jérôme Jullien
- Univ. Lyon, Ecole normale supérieure de Lyon, Université Claude Bernard Lyon 1, CNRS, Differentiation & Cell Cycle Group, Laboratoire de Biologie Moléculaire de la Cellule, UMR5239, 69007 Lyon, France.
| | - David Koubi
- Univ. Lyon, Ecole normale supérieure de Lyon, Université Claude Bernard Lyon 1, CNRS, Differentiation & Cell Cycle Group, Laboratoire de Biologie Moléculaire de la Cellule, UMR5239, 69007 Lyon, France.
| | - Emmanuel Gauthier
- Univ. Lyon, Ecole normale supérieure de Lyon, Université Claude Bernard Lyon 1, CNRS, Differentiation & Cell Cycle Group, Laboratoire de Biologie Moléculaire de la Cellule, UMR5239, 69007 Lyon, France.
| | - David Cluet
- East China Normal University, Key Laboratory of Brain Functional Genomics of the Ministry of Education of PR China, Joint Laboratory of Neuropathogenesis, ECNU, ENS Lyon, CNRS, Shanghai 200062, China.
- Univ. Lyon, Ecole normale supérieure de Lyon, Université Claude Bernard Lyon 1, CNRS, Differentiation & Cell Cycle Group, Laboratoire de Biologie Moléculaire de la Cellule, UMR5239, 69007 Lyon, France.
| | - Julien Falk
- Univ. Lyon, Université Claude Bernard Lyon 1, CNRS, CGphiMC UMR5534, 69622 Villeurbanne Cedex, France.
| | - Valérie Castellani
- Univ. Lyon, Université Claude Bernard Lyon 1, CNRS, CGphiMC UMR5534, 69622 Villeurbanne Cedex, France.
| | - Chonggang Yuan
- East China Normal University, Key Laboratory of Brain Functional Genomics of the Ministry of Education of PR China, Joint Laboratory of Neuropathogenesis, ECNU, ENS Lyon, CNRS, Shanghai 200062, China.
- East China Normal University, School of Life Sciences, Laboratory of Molecular and Cellular Neurophysiology, Shanghai 200062, China.
| | - Brian B Rudkin
- East China Normal University, Key Laboratory of Brain Functional Genomics of the Ministry of Education of PR China, Joint Laboratory of Neuropathogenesis, ECNU, ENS Lyon, CNRS, Shanghai 200062, China.
- Univ. Lyon, Ecole normale supérieure de Lyon, Université Claude Bernard Lyon 1, CNRS, Differentiation & Cell Cycle Group, Laboratoire de Biologie Moléculaire de la Cellule, UMR5239, 69007 Lyon, France.
- Univ. Lyon, Université Claude Bernard Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, 69500 Bron, France.
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19
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Chandrasekaran R, Kenworthy AK, Lacy DB. Clostridium difficile Toxin A Undergoes Clathrin-Independent, PACSIN2-Dependent Endocytosis. PLoS Pathog 2016; 12:e1006070. [PMID: 27942025 PMCID: PMC5152916 DOI: 10.1371/journal.ppat.1006070] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 11/17/2016] [Indexed: 12/18/2022] Open
Abstract
Clostridium difficile infection affects a significant number of hospitalized patients in the United States. Two homologous exotoxins, TcdA and TcdB, are the major virulence factors in C. difficile pathogenesis. The toxins are glucosyltransferases that inactivate Rho family-GTPases to disrupt host cellular function and cause fluid secretion, inflammation, and cell death. Toxicity depends on receptor binding and subsequent endocytosis. TcdB has been shown to enter cells by clathrin-dependent endocytosis, but the mechanism of TcdA uptake is still unclear. Here, we utilize a combination of RNAi-based knockdown, pharmacological inhibition, and cell imaging approaches to investigate the endocytic mechanism(s) that contribute to TcdA uptake and subsequent cytopathic and cytotoxic effects. We show that TcdA uptake and cellular intoxication is dynamin-dependent but does not involve clathrin- or caveolae-mediated endocytosis. Confocal microscopy using fluorescently labeled TcdA shows significant colocalization of the toxin with PACSIN2-positive structures in cells during entry. Disruption of PACSIN2 function by RNAi-based knockdown approaches inhibits TcdA uptake and toxin-induced downstream effects in cells indicating that TcdA entry is PACSIN2-dependent. We conclude that TcdA and TcdB utilize distinct endocytic mechanisms to intoxicate host cells. Clostridium difficile is a bacterial pathogen that causes nearly half a million infections each year in the United States. It infects the human colon and causes diarrhea, colitis and, in some cases, death. C. difficile infection is mediated by the action of two large homologous toxins, TcdA and TcdB. Disruption of host cell function by these toxins requires entry into cells. There are multiple ways for pathogens and virulence factors such as viruses and toxins to enter host cells. The entry mechanism is often directed by a cell surface receptor and can impact the trafficking and virulence properties of the pathogenic factor. Investigating the internalization strategy can provide critical insight into the mechanism of action for specific pathogens and virulence factors. In our current study, we sought to determine the strategy utilized by TcdA to enter host cells. We show that TcdA uptake occurs by a clathrin- and caveolae-independent endocytic mechanism that is mediated by PACSIN2 and dynamin. We also show that TcdA and TcdB can utilize different routes of entry, which may have implications regarding their cytotoxic mechanisms. In summary, our results provide new insights into the mechanism of cellular intoxication by TcdA and the role of PACSIN2 in endocytosis.
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Affiliation(s)
- Ramyavardhanee Chandrasekaran
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN, United States of America
| | - Anne K. Kenworthy
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, United States of America
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, United States of America
- Epithelial Biology Program, Vanderbilt University School of Medicine, Nashville, TN, United States of America
| | - D. Borden Lacy
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN, United States of America
- Epithelial Biology Program, Vanderbilt University School of Medicine, Nashville, TN, United States of America
- The Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN, United States of America
- * E-mail:
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A novel approach for targeted delivery to motoneurons using cholera toxin-B modified protocells. J Neurosci Methods 2016; 273:160-174. [PMID: 27641118 DOI: 10.1016/j.jneumeth.2016.09.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 09/12/2016] [Accepted: 09/13/2016] [Indexed: 12/18/2022]
Abstract
BACKGROUND Trophic interactions between muscle fibers and motoneurons at the neuromuscular junction (NMJ) play a critical role in determining motor function throughout development, ageing, injury, or disease. Treatment of neuromuscular disorders is hindered by the inability to selectively target motoneurons with pharmacological and genetic interventions. NEW METHOD We describe a novel delivery system to motoneurons using mesoporous silica nanoparticles encapsulated within a lipid bilayer (protocells) and modified with the atoxic subunit B of the cholera toxin (CTB) that binds to gangliosides present on neuronal membranes. RESULTS CTB modified protocells showed significantly greater motoneuron uptake compared to unmodified protocells after 24h of treatment (60% vs. 15%, respectively). CTB-protocells showed specific uptake by motoneurons compared to muscle cells and demonstrated cargo release of a surrogate drug. Protocells showed a lack of cytotoxicity and unimpaired cellular proliferation. In isolated diaphragm muscle-phrenic nerve preparations, preferential axon terminal uptake of CTB-modified protocells was observed compared to uptake in surrounding muscle tissue. A larger proportion of axon terminals displayed uptake following treatment with CTB-protocells compared to unmodified protocells (40% vs. 6%, respectively). COMPARISON WITH EXISTING METHOD(S) Current motoneuron targeting strategies lack the functionality to load and deliver multiple cargos. CTB-protocells capitalizes on the advantages of liposomes and mesoporous silica nanoparticles allowing a large loading capacity and cargo release. The ability of CTB-protocells to target motoneurons at the NMJ confers a great advantage over existing methods. CONCLUSIONS CTB-protocells constitute a viable targeted motoneuron delivery system for drugs and genes facilitating various therapies for neuromuscular diseases.
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Paillas S, Ladjohounlou R, Lozza C, Pichard A, Boudousq V, Jarlier M, Sevestre S, Le Blay M, Deshayes E, Sosabowski J, Chardès T, Navarro-Teulon I, Mairs RJ, Pouget JP. Localized Irradiation of Cell Membrane by Auger Electrons Is Cytotoxic Through Oxidative Stress-Mediated Nontargeted Effects. Antioxid Redox Signal 2016; 25:467-84. [PMID: 27224059 PMCID: PMC5028911 DOI: 10.1089/ars.2015.6309] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
AIMS We investigated whether radiation-induced nontargeted effects are involved in the cytotoxic effects of anticell surface monoclonal antibodies labeled with Auger electron emitters, such as iodine 125 (monoclonal antibodies labeled with (125)I [(125)I-mAbs]). RESULTS We showed that the cytotoxicity of (125)I-mAbs targeting the cell membrane of p53(+/+) HCT116 colon cancer cells is mainly due to nontargeted effects. Targeted and nontargeted cytotoxicities were inhibited in vitro following lipid raft disruption with Methyl-β-cyclodextrin (MBCD) or filipin or use of radical oxygen species scavengers. (125)I-mAb efficacy was associated with acid sphingomyelinase activation and modulated through activation of the AKT, extracellular signal-related kinase ½ (ERK1/2), p38 kinase, c-Jun N-terminal kinase (JNK) signaling pathways, and also of phospholipase C-γ (PLC-γ), proline-rich tyrosine kinase 2 (PYK-2), and paxillin, involved in Ca(2+) fluxes. Moreover, the nontargeted response induced by directing 5-[(125)I]iodo-2'-deoxyuridine to the nucleus was comparable to that of (125)I-mAb against cell surface receptors. In vivo, we found that the statistical significance of tumor growth delay induced by (125)I-mAb was removed after MBCD treatment and observed oxidative DNA damage beyond the expected Auger electron range. These results suggest the involvement of nontargeted effects in vivo also. INNOVATION Low-energy Auger electrons, such as those emitted by (125)I, have a short tissue range and are usually targeted to the nucleus to maximize their cytotoxicity. In this study, we show that targeting the cancer cell surface with (125)I-mAbs produces a lipid raft-mediated nontargeted response that compensates for the inferior efficacy of non-nuclear targeting. CONCLUSION Our findings describe the mechanisms involved in the efficacy of (125)I-mAbs targeting the cancer cell surface. Antioxid. Redox Signal. 25, 467-484.
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Affiliation(s)
- Salomé Paillas
- 1 Institut de Recherche en Cancérologie de Montpellier (IRCM) , Montpellier, France .,2 INSERM , U1194, Montpellier, France .,3 Université de Montpellier , Montpellier, France .,4 Institut régional du Cancer de Montpellier , Montpellier, France .,5 Barts Cancer Institute, Queen Mary University of London , London, United Kingdom
| | - Riad Ladjohounlou
- 1 Institut de Recherche en Cancérologie de Montpellier (IRCM) , Montpellier, France .,2 INSERM , U1194, Montpellier, France .,3 Université de Montpellier , Montpellier, France .,4 Institut régional du Cancer de Montpellier , Montpellier, France
| | - Catherine Lozza
- 1 Institut de Recherche en Cancérologie de Montpellier (IRCM) , Montpellier, France .,2 INSERM , U1194, Montpellier, France .,3 Université de Montpellier , Montpellier, France .,4 Institut régional du Cancer de Montpellier , Montpellier, France
| | - Alexandre Pichard
- 1 Institut de Recherche en Cancérologie de Montpellier (IRCM) , Montpellier, France .,2 INSERM , U1194, Montpellier, France .,3 Université de Montpellier , Montpellier, France .,4 Institut régional du Cancer de Montpellier , Montpellier, France
| | - Vincent Boudousq
- 1 Institut de Recherche en Cancérologie de Montpellier (IRCM) , Montpellier, France .,2 INSERM , U1194, Montpellier, France .,3 Université de Montpellier , Montpellier, France .,4 Institut régional du Cancer de Montpellier , Montpellier, France
| | - Marta Jarlier
- 4 Institut régional du Cancer de Montpellier , Montpellier, France
| | - Samuel Sevestre
- 1 Institut de Recherche en Cancérologie de Montpellier (IRCM) , Montpellier, France .,2 INSERM , U1194, Montpellier, France .,3 Université de Montpellier , Montpellier, France .,4 Institut régional du Cancer de Montpellier , Montpellier, France
| | - Marion Le Blay
- 1 Institut de Recherche en Cancérologie de Montpellier (IRCM) , Montpellier, France .,2 INSERM , U1194, Montpellier, France .,3 Université de Montpellier , Montpellier, France .,4 Institut régional du Cancer de Montpellier , Montpellier, France
| | - Emmanuel Deshayes
- 1 Institut de Recherche en Cancérologie de Montpellier (IRCM) , Montpellier, France .,2 INSERM , U1194, Montpellier, France .,3 Université de Montpellier , Montpellier, France .,4 Institut régional du Cancer de Montpellier , Montpellier, France
| | - Jane Sosabowski
- 5 Barts Cancer Institute, Queen Mary University of London , London, United Kingdom
| | - Thierry Chardès
- 1 Institut de Recherche en Cancérologie de Montpellier (IRCM) , Montpellier, France .,2 INSERM , U1194, Montpellier, France .,3 Université de Montpellier , Montpellier, France .,4 Institut régional du Cancer de Montpellier , Montpellier, France
| | - Isabelle Navarro-Teulon
- 1 Institut de Recherche en Cancérologie de Montpellier (IRCM) , Montpellier, France .,2 INSERM , U1194, Montpellier, France .,3 Université de Montpellier , Montpellier, France .,4 Institut régional du Cancer de Montpellier , Montpellier, France
| | - Robert J Mairs
- 6 Institute of Cancer Sciences, University of Glasgow , Glasgow, Scotland
| | - Jean-Pierre Pouget
- 1 Institut de Recherche en Cancérologie de Montpellier (IRCM) , Montpellier, France .,2 INSERM , U1194, Montpellier, France .,3 Université de Montpellier , Montpellier, France .,4 Institut régional du Cancer de Montpellier , Montpellier, France
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Hypoxia regulates global membrane protein endocytosis through caveolin-1 in cancer cells. Nat Commun 2016; 7:11371. [PMID: 27094744 PMCID: PMC4842985 DOI: 10.1038/ncomms11371] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 03/18/2016] [Indexed: 01/12/2023] Open
Abstract
Hypoxia promotes tumour aggressiveness and resistance of cancers to oncological treatment. The identification of cancer cell internalizing antigens for drug targeting to the hypoxic tumour niche remains a challenge of high clinical relevance. Here we show that hypoxia down-regulates the surface proteome at the global level and, more specifically, membrane proteome internalization. We find that hypoxic down-regulation of constitutive endocytosis is HIF-independent, and involves caveolin-1-mediated inhibition of dynamin-dependent, membrane raft endocytosis. Caveolin-1 overexpression inhibits protein internalization, suggesting a general negative regulatory role of caveolin-1 in endocytosis. In contrast to this global inhibitory effect, we identify several proteins that can override caveolin-1 negative regulation, exhibiting increased internalization at hypoxia. We demonstrate antibody-mediated cytotoxin delivery and killing specifically of hypoxic cells through one of these proteins, carbonic anhydrase IX. Our data reveal that caveolin-1 modulates cell-surface proteome turnover at hypoxia with potential implications for specific targeting of the hypoxic tumour microenvironment. Hypoxia promotes tumour aggressiveness and resistance of cancers to oncological treatment. Here, the authors show that caveolin-1 can down-regulate global membrane protein endocytosis in hypoxic cells with potential implications for targeting the hypoxic 3microenvironment of aggressive tumours.
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Rosazza C, Deschout H, Buntz A, Braeckmans K, Rols MP, Zumbusch A. Endocytosis and Endosomal Trafficking of DNA After Gene Electrotransfer In Vitro. MOLECULAR THERAPY-NUCLEIC ACIDS 2016; 5:e286. [PMID: 26859199 PMCID: PMC4884790 DOI: 10.1038/mtna.2015.59] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 12/18/2015] [Indexed: 01/08/2023]
Abstract
DNA electrotransfer is a successful technique for gene delivery into cells and represents an attractive alternative to virus-based methods for clinical applications including gene therapy and DNA vaccination. However, little is currently known about the mechanisms governing DNA internalization and its fate inside cells. The objectives of this work were to investigate the role of endocytosis and to quantify the contribution of different routes of cellular trafficking during DNA electrotransfer. To pursue these objectives, we performed flow cytometry and single-particle fluorescence microscopy experiments using inhibitors of endocytosis and endosomal markers. Our results show that ~50% of DNA is internalized by caveolin/raft-mediated endocytosis, 25% by clathrin-mediated endocytosis, and 25% by macropinocytosis. During active transport, DNA is routed through multiple endosomal compartments with, in the hour following electrotransfer, 70% found in Rab5 structures, 50% in Rab11-containing organelles and 30% in Rab9 compartments. Later, 60% of DNA colocalizes with Lamp1 vesicles. Because these molecular markers can overlap while following organelles through several steps of trafficking, the percentages do not sum up to 100%. We conclude that electrotransferred DNA uses the classical endosomal trafficking pathways. Our results are important for a generalized understanding of gene electrotransfer, which is crucial for its safe use in clinics.
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Affiliation(s)
- Christelle Rosazza
- Department of Chemistry, University of Konstanz, Konstanz, Germany.,Department of Structural Biology and Biophysics, Institute of Pharmacology and Structural Biology (IPBS), CNRS UMR5089, Toulouse, France.,University of Toulouse III, UPS, Toulouse, France
| | - Hendrik Deschout
- Laboratory of General Biochemistry and Physical Pharmacy, Department of Pharmaceutics, University of Ghent, Ghent, Belgium
| | - Annette Buntz
- Department of Chemistry, University of Konstanz, Konstanz, Germany
| | - Kevin Braeckmans
- Laboratory of General Biochemistry and Physical Pharmacy, Department of Pharmaceutics, University of Ghent, Ghent, Belgium
| | - Marie-Pierre Rols
- Department of Structural Biology and Biophysics, Institute of Pharmacology and Structural Biology (IPBS), CNRS UMR5089, Toulouse, France.,University of Toulouse III, UPS, Toulouse, France
| | - Andreas Zumbusch
- Department of Chemistry, University of Konstanz, Konstanz, Germany
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Rosazza C, Meglic SH, Zumbusch A, Rols MP, Miklavcic D. Gene Electrotransfer: A Mechanistic Perspective. Curr Gene Ther 2016; 16:98-129. [PMID: 27029943 PMCID: PMC5412002 DOI: 10.2174/1566523216666160331130040] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 03/21/2016] [Accepted: 03/22/2016] [Indexed: 11/22/2022]
Abstract
Gene electrotransfer is a powerful method of DNA delivery offering several medical applications, among the most promising of which are DNA vaccination and gene therapy for cancer treatment. Electroporation entails the application of electric fields to cells which then experience a local and transient change of membrane permeability. Although gene electrotransfer has been extensively studied in in vitro and in vivo environments, the mechanisms by which DNA enters and navigates through cells are not fully understood. Here we present a comprehensive review of the body of knowledge concerning gene electrotransfer that has been accumulated over the last three decades. For that purpose, after briefly reviewing the medical applications that gene electrotransfer can provide, we outline membrane electropermeabilization, a key process for the delivery of DNA and smaller molecules. Since gene electrotransfer is a multipart process, we proceed our review in describing step by step our current understanding, with particular emphasis on DNA internalization and intracellular trafficking. Finally, we turn our attention to in vivo testing and methodology for gene electrotransfer.
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Affiliation(s)
| | | | | | - Marie-Pierre Rols
- Institute of Pharmacology and Structural Biology (IPBS), CNRS UMR5089, 205 route de Narbonne, 31077 Toulouse, France.
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Trane AE, Hiob MA, Uy T, Pavlov D, Bernatchez P. Caveolin-1 scaffolding domain residue phenylalanine 92 modulates Akt signaling. Eur J Pharmacol 2015; 766:46-55. [DOI: 10.1016/j.ejphar.2015.09.033] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 09/18/2015] [Accepted: 09/21/2015] [Indexed: 02/02/2023]
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26
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Frossard CP, Asigbetse KE, Burger D, Eigenmann PA. Gut T cell receptor-γδ(+) intraepithelial lymphocytes are activated selectively by cholera toxin to break oral tolerance in mice. Clin Exp Immunol 2015; 180:118-30. [PMID: 25430688 DOI: 10.1111/cei.12561] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2014] [Indexed: 01/13/2023] Open
Abstract
The gut immune system is usually tolerant to harmless foreign antigens such as food proteins. However, tolerance breakdown may occur and lead to food allergy. To study mechanisms underlying food allergy, animal models have been developed in mice by using cholera toxin (CT) to break tolerance. In this study, we identify T cell receptor (TCR)-γδ(+) intraepithelial lymphocytes (IELs) as major targets of CT to break tolerance to food allergens. TCR-γδ(+) IEL-enriched cell populations isolated from mice fed with CT and transferred to naive mice hamper tolerization to the food allergen β-lactoglobulin (BLG) in recipient mice which produce anti-BLG immunoglobulin (Ig)G1 antibodies. Furthermore, adoptive transfer of TCR-γδ(+) cells from CT-fed mice triggers the production of anti-CT IgG1 antibodies in recipient mice that were never exposed to CT, suggesting antigen-presenting cell (APC)-like functions of TCR-γδ(+) IELs. In contrast to TCR-αβ(+) cells, TCR-γδ(+) IELs bind and internalize CT both in vitro and in vivo. CT-activated TCR-γδ(+) IELs express major histocompatibility complex (MHC) class II molecules, CD80 and CD86 demonstrating an APC phenotype. CT-activated TCR-γδ(+) IELs migrate to the lamina propria, where they produce interleukin (IL)-10 and IL-17. These results provide in-vivo evidence for a major role of TCR-γδ(+) IELs in the modulation of oral tolerance in the pathogenesis of food allergy.
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Affiliation(s)
- C P Frossard
- Inflammation and Allergy Research Group, University Hospitals of Geneva and University of Geneva, Geneva, Switzerland
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27
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Galectin-3 Overrides PTRF/Cavin-1 Reduction of PC3 Prostate Cancer Cell Migration. PLoS One 2015; 10:e0126056. [PMID: 25942420 PMCID: PMC4420459 DOI: 10.1371/journal.pone.0126056] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Accepted: 03/28/2015] [Indexed: 12/31/2022] Open
Abstract
Expression of Caveolin-1 (Cav1), a key component of cell surface caveolae, is elevated in prostate cancer (PCa) and associated with PCa metastasis and a poor prognosis for PCa patients. Polymerase I and Transcript Release Factor (PTRF)/cavin-1 is a cytoplasmic protein required for Cav1-dependent formation of caveolae. Expression of PTRF reduces the motility of PC3 cells, a metastatic prostate cancer cell line that endogenously expresses abundant Cav1 but no PTRF and no caveolae, suggesting a role for non-caveolar Cav1 domains, or Cav1 scaffolds, in PCa cell migration. Tyrosine phosphorylated Cav1 (pCav1) functions in concert with Galectin-3 (Gal3) and the galectin lattice to stabilize focal adhesion kinase (FAK) within focal adhesions (FAs) and promote cancer cell motility. However, whether PTRF regulation of Cav1 function in PCa cell migration is related to Gal3 expression and functionality has yet to be determined. Here we show that PTRF expression in PC3 cells reduces FAK stabilization in focal adhesions and reduces cell motility without affecting pCav1 levels. Exogenous Gal3 stabilized FAK in focal adhesions of PTRF-expressing cells and restored cell motility of PTRF-expressing PC3 cells to levels of PC3 cells in a dose-dependent manner, with an optimal concentration of 2 µg/ml. Exogenous Gal3 stabilized FAK in focal adhesions of Gal3 knockdown PC3 cells but not in Cav1 knockdown PC3 cells. Cav1 knockdown also prevented Gal3 rescue of FA-associated FAK stabilization in PTRF-expressing PC3 cells. Our data support a role for PTRF/cavin-1, through caveolae formation, as an attenuator of the non-caveolar functionality of Cav1 in Gal3-Cav1 signalling and regulation of focal adhesion dynamics and cancer cell migration.
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Aigal S, Claudinon J, Römer W. Plasma membrane reorganization: A glycolipid gateway for microbes. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1853:858-71. [PMID: 25450969 DOI: 10.1016/j.bbamcr.2014.11.014] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 09/27/2014] [Accepted: 11/11/2014] [Indexed: 02/08/2023]
Abstract
Ligand-receptor interactions, which represent the core for cell signaling and internalization processes are largely affected by the spatial configuration of host cell receptors. There is a growing piece of evidence that receptors are not homogeneously distributed within the plasma membrane, but are rather pre-clustered in nanodomains, or clusters are formed upon ligand binding. Pathogens have evolved many strategies to evade the host immune system and to ensure their survival by hijacking plasma membrane receptors that are most often associated with lipid rafts. In this review, we discuss the early stage molecular and physiological events that occur following ligand binding to host cell glycolipids. The ability of various biological ligands (e.g. toxins, lectins, viruses or bacteria) that bind to glycolipids to induce their own uptake into mammalian cells by creating negative membrane curvature and membrane invaginations is explored. We highlight recent trends in understanding nanoscale plasma membrane (re-)organization and present the benefits of using synthetic membrane systems. This article is part of a Special Issue entitled: Nanoscale membrane organisation and signalling.
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Affiliation(s)
- Sahaja Aigal
- Faculty of Biology, Albert-Ludwigs-University Freiburg, Schänzlestraße 1, 79104 Freiburg, Germany; BIOSS Centre for Biological Signaling Studies, Albert-Ludwigs-University Freiburg, Schänzlestraβe 18, 79104 Freiburg, Germany; International Max Planck Research School for Molecular and Cellular Biology (IMPRS-MCB), Max Planck Institute of Immunobiology and Epigenetics, Stübeweg 51, 79108 Freiburg, Germany.
| | - Julie Claudinon
- Faculty of Biology, Albert-Ludwigs-University Freiburg, Schänzlestraße 1, 79104 Freiburg, Germany; BIOSS Centre for Biological Signaling Studies, Albert-Ludwigs-University Freiburg, Schänzlestraβe 18, 79104 Freiburg, Germany
| | - Winfried Römer
- Faculty of Biology, Albert-Ludwigs-University Freiburg, Schänzlestraße 1, 79104 Freiburg, Germany; BIOSS Centre for Biological Signaling Studies, Albert-Ludwigs-University Freiburg, Schänzlestraβe 18, 79104 Freiburg, Germany.
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Margheri F, Papucci L, Schiavone N, D'Agostino R, Trigari S, Serratì S, Laurenzana A, Biagioni A, Luciani C, Chillà A, Andreucci E, Del Rosso T, Margheri G, Del Rosso M, Fibbi G. Differential uPAR recruitment in caveolar-lipid rafts by GM1 and GM3 gangliosides regulates endothelial progenitor cells angiogenesis. J Cell Mol Med 2014; 19:113-23. [PMID: 25313007 PMCID: PMC4288355 DOI: 10.1111/jcmm.12410] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 07/24/2014] [Indexed: 12/13/2022] Open
Abstract
Gangliosides and the urokinase plasminogen activator receptor (uPAR) tipically partition in specialized membrane microdomains called lipid-rafts. uPAR becomes functionally important in fostering angiogenesis in endothelial progenitor cells (EPCs) upon recruitment in caveolar-lipid rafts. Moreover, cell membrane enrichment with exogenous GM1 ganglioside is pro-angiogenic and opposite to the activity of GM3 ganglioside. On these basis, we first checked the interaction of uPAR with membrane models enriched with GM1 or GM3, relying on the adoption of solid-supported mobile bilayer lipid membranes with raft-like composition formed onto solid hydrophilic surfaces, and evaluated by surface plasmon resonance (SPR) the extent of uPAR recruitment. We estimated the apparent dissociation constants of uPAR-GM1/GM3 complexes. These preliminary observations, indicating that uPAR binds preferentially to GM1-enriched biomimetic membranes, were validated by identifying a pro-angiogenic activity of GM1-enriched EPCs, based on GM1-dependent uPAR recruitment in caveolar rafts. We have observed that addition of GM1 to EPCs culture medium promotes matrigel invasion and capillary morphogenesis, as opposed to the anti-angiogenesis activity of GM3. Moreover, GM1 also stimulates MAPKinases signalling pathways, typically associated with an angiogenesis program. Caveolar-raft isolation and Western blotting of uPAR showed that GM1 promotes caveolar-raft partitioning of uPAR, as opposed to control and GM3-challenged EPCs. By confocal microscopy, we have shown that in EPCs uPAR is present on the surface in at least three compartments, respectively, associated to GM1, GM3 and caveolar rafts. Following GM1 exogenous addition, the GM3 compartment is depleted of uPAR which is recruited within caveolar rafts thereby triggering angiogenesis.
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Affiliation(s)
- Francesca Margheri
- Department of Experimental and Clinical Biomedical Sciences, Section of Experimental Pathology and Oncology, University of Florence, Florence, Italy
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Nagasawa S, Ogura K, Tsutsuki H, Saitoh H, Moss J, Iwase H, Noda M, Yahiro K. Uptake of Shiga-toxigenic Escherichia coli SubAB by HeLa cells requires an actin- and lipid raft-dependent pathway. Cell Microbiol 2014; 16:1582-601. [PMID: 24844382 DOI: 10.1111/cmi.12315] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 05/07/2014] [Accepted: 05/08/2014] [Indexed: 02/06/2023]
Abstract
The novel cytotoxic factor subtilase cytotoxin (SubAB) is produced mainly by non-O157 Shiga-toxigenic Escherichia coli (STEC). SubAB cleaves the molecular chaperone BiP/GRP78 in the endoplasmic reticulum (ER), leading to activation of RNA-dependent protein kinase (PKR)-like ER kinase (PERK), followed by caspase-dependent cell death. However, the SubAB uptake mechanism in HeLa cells is unknown. In this study, a variety of inhibitors and siRNAs were employed to characterize the SubAB uptake process. SubAB-induced BiP cleavage was inhibited by high concentrations of Dynasore, and methyl-β-cyclodextrin (mβCD) and Filipin III, but not suppressed in clathrin-, dynamin I/II-, caveolin1- and caveolin2-knockdown cells. We observed that SubAB treatment led to dramatic actin rearrangements, e.g. formation of plasma membrane blebs, with a significant increase in fluid uptake. Confocal microscopy analysis showed that SubAB uptake required actin cytoskeleton remodelling and lipid raft cholesterol. Furthermore, internalized SubAB in cells was found in the detergent-resistant domain (DRM) structure. Interestingly, IPA-3, an inhibitor of serine/threonine kinase p21-activated kinase (PAK1), an important protein of macropinocytosis, directly inhibited SubAB-mediated BiP cleavage and SubAB internalization. Thus, our findings suggest that SubAB uses lipid raft- and actin-dependent, but not clathrin-, caveolin- and dynamin-dependent pathways as its major endocytic translocation route.
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Affiliation(s)
- Sayaka Nagasawa
- Department of Legal Medicine, Graduate School of Medicine, Chiba University, Chiba, 260-8670, Japan
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Bennett NC, Hooper JD, Johnson DW, Gobe GC. Expression profiles and functional associations of endogenous androgen receptor and caveolin-1 in prostate cancer cell lines. Prostate 2014; 74:478-87. [PMID: 24375805 DOI: 10.1002/pros.22767] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 12/02/2013] [Indexed: 01/01/2023]
Abstract
BACKGROUND In prostate cancer (PCa) patients, the protein target for androgen deprivation and blockade therapies is androgen receptor (AR). AR interacts with many proteins that function to either co-activate or co-repress its activity. Caveolin-1 (Cav-1) is not found in normal prostatic epithelium, but is found in PCa, and may be an AR co-regulator protein. METHODS We investigated cell line-specific signatures and associations of endogenous AR and Cav-1 in six PCa cell lines of known androgen sensitivity: LNCaP (androgen sensitive); 22Rv1 (androgen responsive); PC3, DU145, and ALVA41 (androgen non-reliant); and RWPE1 (non-malignant). Protein and mRNA expression profiles were compared and electron microscopy used to identify cells with caveolar structures. For cell lines expressing both AR and Cav-1, knockdown techniques using small interfering RNA against AR or Cav-1 were used to test whether diminished expression of one affected the other. Co-sedimentation of AR and Cav-1 was used to test their association. A reporter assay for AR genomic activity was utilized following Cav-1 knockdown. RESULTS AR-expressing LNCaP and 22Rv1 cells had low endogenous Cav-1 mRNA and protein. Cell lines that expressed little or no AR (DU145, PC3, ALVA41, and RWPE1) expressed high endogenous levels of Cav-1. AR knockdown in LNCaP cells had little effect on Cav-1, but Cav-1 knockdown inhibited AR expression and genomic activity. CONCLUSIONS These data show endogenous AR and Cav-1 mRNA and protein expression is inversely related in PCa cells, with Cav-1 acting on the androgen/AR signaling axis possibly as an AR co-activator, demonstrated by diminished AR genomic activity following Cav-1 knockdown.
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Affiliation(s)
- Nigel C Bennett
- Centre for Kidney Disease Research, School of Medicine, University of Queensland, Translational Research Institute, Woolloongabba, Brisbane, Australia
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Rosa IDA, Atella G, Benchimol M. Tritrichomonas foetus displays classical detergent-resistant membrane microdomains on its cell surface. Protist 2014; 165:293-304. [PMID: 24742927 DOI: 10.1016/j.protis.2014.03.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 03/18/2014] [Accepted: 03/19/2014] [Indexed: 11/27/2022]
Abstract
Tritrichomonas foetus is a serious veterinary parasite that causes bovine trichomoniasis, a sexually transmitted disease that results in reproductive failure and considerable economic losses in areas that practice natural breeding. T. foetus is an extracellular parasite, which initially adheres to and infects the urogenital tract using a diverse array of surface glycoconjugates, including adhesins and extracellular matrix-binding molecules. However, the cellular mechanisms by which T. foetus colonizes mucosal surfaces and causes tissue damage are not well defined. Several studies have demonstrated the involvement of pathogen or host lipid rafts in cellular events that occur during pathogenesis, including adhesion, invasion and evasion of the immune response. In this study, we demonstrate that detergent-resistant membranes are present in the plasma membrane of T. foetus. We further demonstrate that microdomains are cholesterol-enriched and contain ganglioside GM1-like molecules. In addition, we demonstrate that lipid microdomains do not participate in T. foetus adhesion to host cells. However, the use of agents that disrupt and disorganize the plasma membrane indicated the involvement of the T. foetus lipid microdomains, in cell division and in the formation of endoflagellar forms. Our results suggest that trophozoites and endoflagellar forms present a different plasma membrane organization.
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Affiliation(s)
- Ivone de Andrade Rosa
- Universidade Santa Úrsula, Rua Jornalista Orlando Dantas 59, Botafogo, CEP 22231-010 Rio de Janeiro, RJ, Brazil; Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Brazil
| | - Georgia Atella
- Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Brazil
| | - Marlene Benchimol
- Universidade Santa Úrsula, Rua Jornalista Orlando Dantas 59, Botafogo, CEP 22231-010 Rio de Janeiro, RJ, Brazil.
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Chaudhary N, Gomez GA, Howes MT, Lo HP, McMahon KA, Rae JA, Schieber NL, Hill MM, Gaus K, Yap AS, Parton RG. Endocytic crosstalk: cavins, caveolins, and caveolae regulate clathrin-independent endocytosis. PLoS Biol 2014; 12:e1001832. [PMID: 24714042 PMCID: PMC3979662 DOI: 10.1371/journal.pbio.1001832] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 02/25/2014] [Indexed: 12/18/2022] Open
Abstract
Caveolar proteins and caveolae negatively regulate a second clathrin-independent endocytic CLIC/GEEC pathway; caveolin-1 affects membrane diffusion properties of raft-associated CLIC cargo, and the scaffolding domain of caveolin-1 is required and sufficient for endocytic inhibition. Several studies have suggested crosstalk between different clathrin-independent endocytic pathways. However, the molecular mechanisms and functional relevance of these interactions are unclear. Caveolins and cavins are crucial components of caveolae, specialized microdomains that also constitute an endocytic route. Here we show that specific caveolar proteins are independently acting negative regulators of clathrin-independent endocytosis. Cavin-1 and Cavin-3, but not Cavin-2 or Cavin-4, are potent inhibitors of the clathrin-independent carriers/GPI-AP enriched early endosomal compartment (CLIC/GEEC) endocytic pathway, in a process independent of caveola formation. Caveolin-1 (CAV1) and CAV3 also inhibit the CLIC/GEEC pathway upon over-expression. Expression of caveolar protein leads to reduction in formation of early CLIC/GEEC carriers, as detected by quantitative electron microscopy analysis. Furthermore, the CLIC/GEEC pathway is upregulated in cells lacking CAV1/Cavin-1 or with reduced expression of Cavin-1 and Cavin-3. Inhibition by caveolins can be mimicked by the isolated caveolin scaffolding domain and is associated with perturbed diffusion of lipid microdomain components, as revealed by fluorescence recovery after photobleaching (FRAP) studies. In the absence of cavins (and caveolae) CAV1 is itself endocytosed preferentially through the CLIC/GEEC pathway, but the pathway loses polarization and sorting attributes with consequences for membrane dynamics and endocytic polarization in migrating cells and adult muscle tissue. We also found that noncaveolar Cavin-1 can act as a modulator for the activity of the key regulator of the CLIC/GEEC pathway, Cdc42. This work provides new insights into the regulation of noncaveolar clathrin-independent endocytosis by specific caveolar proteins, illustrating multiple levels of crosstalk between these pathways. We show for the first time a role for specific cavins in regulating the CLIC/GEEC pathway, provide a new tool to study this pathway, identify caveola-independent functions of the cavins and propose a novel mechanism for inhibition of the CLIC/GEEC pathway by caveolin. Endocytosis is the process that allows cells to take up molecules from the environment. Several endocytic pathways exist in mammalian cells. While the best understood endocytic pathway uses clathrin, recent years have seen a great increase in our understanding of clathrin-independent endocytic pathways. Here we characterize the crosstalk between caveolae, flask-shaped specialized microdomains present at the plasma membrane, and a second clathrin-independent pathway, the CLIC/GEEC Cdc42-regulated endocytic pathway. These pathways are segregated in migrating cells with caveolae at the rear and CLIC/GEEC endocytosis at the leading edge. Here we find that specific caveolar proteins, caveolins and cavins, can also negatively regulate the CLIC/GEEC pathway. With the help of several techniques, including quantitative electron microscopy analysis and real-time live-cell imaging, we demonstrate that expression of caveolar proteins affects early carrier formation, causes cellular lipid changes, and changes the activity of the key regulator of the CLIC/GEEC pathway, Cdc42. The functional consequences of loss of caveolar proteins on the CLIC/GEEC pathway included inhibition of polarized cell migration and increased endocytosis in tissue explants.
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Affiliation(s)
- Natasha Chaudhary
- The University of Queensland, Institute for Molecular Bioscience, Queensland, Australia
| | - Guillermo A. Gomez
- The University of Queensland, Institute for Molecular Bioscience, Queensland, Australia
| | - Mark T. Howes
- The University of Queensland, Institute for Molecular Bioscience, Queensland, Australia
| | - Harriet P. Lo
- The University of Queensland, Institute for Molecular Bioscience, Queensland, Australia
| | - Kerrie-Ann McMahon
- The University of Queensland, Institute for Molecular Bioscience, Queensland, Australia
| | - James A. Rae
- The University of Queensland, Institute for Molecular Bioscience, Queensland, Australia
| | - Nicole L. Schieber
- The University of Queensland, Institute for Molecular Bioscience, Queensland, Australia
| | - Michelle M. Hill
- The University of Queensland, Diamantina Institute, Queensland, Australia
| | - Katharina Gaus
- The University of New South Wales, Centre for Vascular Research and Australian Centre for Nanomedicine, New South Wales, Australia
| | - Alpha S. Yap
- The University of Queensland, Institute for Molecular Bioscience, Queensland, Australia
| | - Robert G. Parton
- The University of Queensland, Institute for Molecular Bioscience, Queensland, Australia
- Centre for Microscopy and Microanalysis, Queensland, Australia
- * E-mail:
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Peikert K, Kasper M, May CA. Distribution of caveolin in the muscle spindles of human skeletal muscle. J Anat 2014; 224:681-7. [PMID: 24660982 DOI: 10.1111/joa.12173] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/20/2014] [Indexed: 01/16/2023] Open
Abstract
The aim of the present study was to demonstrate the location of the different members of the caveolin (cav) family in human muscle spindles. Twenty spindles of three human muscles (vastus medialis, ischiocavernosus, bulbospongiosus) from 12 cadavers were immunohistochemically stained for cav-1, cav-2, and cav-3, and the equatorial and polar regions evaluated. All layers of the outer and inner spindle capsule and all blood vessels within the spindle stained for cav-1 and cav-2. In the muscle spindle, intrafusal muscle fibres stained selectively for cav-3, but with a patchy appearance. Caveolinopathies may therefore also include changes in muscle spindle function.
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Affiliation(s)
- Kevin Peikert
- Department of Anatomy, Medical Faculty Carl Gustav Carus, TU Dresden, Dresden, Germany
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Salinas S, Zussy C, Loustalot F, Henaff D, Menendez G, Morton PE, Parsons M, Schiavo G, Kremer EJ. Disruption of the coxsackievirus and adenovirus receptor-homodimeric interaction triggers lipid microdomain- and dynamin-dependent endocytosis and lysosomal targeting. J Biol Chem 2013; 289:680-95. [PMID: 24273169 DOI: 10.1074/jbc.m113.518365] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The coxsackievirus and adenovirus receptor (CAR) serves as a docking factor for some adenovirus (AdV) types and group B coxsackieviruses. Its role in AdV internalization is unclear as studies suggest that its intracellular domain is dispensable for some AdV infection. We previously showed that in motor neurons, AdV induced CAR internalization and co-transport in axons, suggesting that CAR was linked to endocytic and long-range transport machineries. Here, we characterized the mechanisms of CAR endocytosis in neurons and neuronal cells. We found that CAR internalization was lipid microdomain-, actin-, and dynamin-dependent, and subsequently followed by CAR degradation in lysosomes. Moreover, ligands that disrupted the homodimeric CAR interactions in its D1 domains triggered an internalization cascade involving sequences in its intracellular tail.
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Affiliation(s)
- Sara Salinas
- From the Institut de Génétique Moléculaire de Montpellier, CNRS UMR 5535, Montpellier, Universités de Montpellier I & II, Montpellier, France
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Abstract
Although Epstein-Barr virus (EBV) is an orally transmitted virus, viral transmission through the oropharyngeal mucosal epithelium is not well understood. In this study, we investigated how EBV traverses polarized human oral epithelial cells without causing productive infection. We found that EBV may be transcytosed through oral epithelial cells bidirectionally, from both the apical to the basolateral membranes and the basolateral to the apical membranes. Apical to basolateral EBV transcytosis was substantially reduced by amiloride, an inhibitor of macropinocytosis. Electron microscopy showed that virions were surrounded by apical surface protrusions and that virus was present in subapical vesicles. Inactivation of signaling molecules critical for macropinocytosis, including phosphatidylinositol 3-kinases, myosin light-chain kinase, Ras-related C3 botulinum toxin substrate 1, p21-activated kinase 1, ADP-ribosylation factor 6, and cell division control protein 42 homolog, led to significant reduction in EBV apical to basolateral transcytosis. In contrast, basolateral to apical EBV transcytosis was substantially reduced by nystatin, an inhibitor of caveolin-mediated virus entry. Caveolae were detected in the basolateral membranes of polarized human oral epithelial cells, and virions were detected in caveosome-like endosomes. Methyl β-cyclodextrin, an inhibitor of caveola formation, reduced EBV basolateral entry. EBV virions transcytosed in either direction were able to infect B lymphocytes. Together, these data show that EBV transmigrates across oral epithelial cells by (i) apical to basolateral transcytosis, potentially contributing to initial EBV penetration that leads to systemic infection, and (ii) basolateral to apical transcytosis, which may enable EBV secretion into saliva in EBV-infected individuals.
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Hitkova I, Yuan G, Anderl F, Gerhard M, Kirchner T, Reu S, Röcken C, Schäfer C, Schmid RM, Vogelmann R, Ebert MPA, Burgermeister E. Caveolin-1 protects B6129 mice against Helicobacter pylori gastritis. PLoS Pathog 2013; 9:e1003251. [PMID: 23592983 PMCID: PMC3623771 DOI: 10.1371/journal.ppat.1003251] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Accepted: 02/04/2013] [Indexed: 02/07/2023] Open
Abstract
Caveolin-1 (Cav1) is a scaffold protein and pathogen receptor in the mucosa of the gastrointestinal tract. Chronic infection of gastric epithelial cells by Helicobacter pylori (H. pylori) is a major risk factor for human gastric cancer (GC) where Cav1 is frequently down-regulated. However, the function of Cav1 in H. pylori infection and pathogenesis of GC remained unknown. We show here that Cav1-deficient mice, infected for 11 months with the CagA-delivery deficient H. pylori strain SS1, developed more severe gastritis and tissue damage, including loss of parietal cells and foveolar hyperplasia, and displayed lower colonisation of the gastric mucosa than wild-type B6129 littermates. Cav1-null mice showed enhanced infiltration of macrophages and B-cells and secretion of chemokines (RANTES) but had reduced levels of CD25+ regulatory T-cells. Cav1-deficient human GC cells (AGS), infected with the CagA-delivery proficient H. pylori strain G27, were more sensitive to CagA-related cytoskeletal stress morphologies (“humming bird”) compared to AGS cells stably transfected with Cav1 (AGS/Cav1). Infection of AGS/Cav1 cells triggered the recruitment of p120 RhoGTPase-activating protein/deleted in liver cancer-1 (p120RhoGAP/DLC1) to Cav1 and counteracted CagA-induced cytoskeletal rearrangements. In human GC cell lines (MKN45, N87) and mouse stomach tissue, H. pylori down-regulated endogenous expression of Cav1 independently of CagA. Mechanistically, H. pylori activated sterol-responsive element-binding protein-1 (SREBP1) to repress transcription of the human Cav1 gene from sterol-responsive elements (SREs) in the proximal Cav1 promoter. These data suggested a protective role of Cav1 against H. pylori-induced inflammation and tissue damage. We propose that H. pylori exploits down-regulation of Cav1 to subvert the host's immune response and to promote signalling of its virulence factors in host cells. Infection with the bacterium Helicobacter pylori (H. pylori) mainly affects children in the developing countries who are at risk to progress to gastric cancer (GC) as adults after many years of persistent infection, especially with strains which are positive for the oncogenic virulence factor CagA. Eradication of H. pylori by antibiotics is a treatment of choice but may also alter the susceptibility to allergies and other tumor types. Thus, novel diagnostic or prognostic markers are needed which detect early molecular changes in the stomach mucosa during the transition of chronic inflammation to cancer. In our study, we found that the tumor suppressor caveolin-1 (Cav1) is reduced upon infection with H. pylori, and CagA was sufficient but not necessary for this down-regulation. Loss of Cav1 was caused by H. pylori-dependent activation of sterol-responsive element-binding protein-1 (SREBP1), and this event abolished the interaction of Cav1 with p120 RhoGTPase-activating protein/deleted in liver cancer-1 (p120RhoGAP/DLC1), a second bona fide tumor suppressor in gastric tissue. Conclusively, Cav1 and DLC1 may constitute novel molecular markers in the H. pylori-infected gastric mucosa before neoplastic transformation of the epithelium.
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Affiliation(s)
- Ivana Hitkova
- Department of Medicine II, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Gang Yuan
- Department of Gastroenterology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Florian Anderl
- Institute of Medical Microbiology, Immunology and Hygiene, Technische Universität München, München, Germany
| | - Markus Gerhard
- Institute of Medical Microbiology, Immunology and Hygiene, Technische Universität München, München, Germany
- German Centre for Infection Research (DZIF), München, Germany
| | - Thomas Kirchner
- Institute of Pathology, Klinikum der Universität München, München, Germany
| | - Simone Reu
- Institute of Pathology, Klinikum der Universität München, München, Germany
| | - Christoph Röcken
- Department of Pathology, Christian-Albrechts Universität, Kiel, Germany
| | - Claus Schäfer
- Department of Medicine II, Klinikum der Universität München, München, Germany
| | - Roland M. Schmid
- Department of Medicine II, Klinikum rechts der Isar, Technische Universität München, München, Germany
| | - Roger Vogelmann
- Department of Medicine II, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Matthias P. A. Ebert
- Department of Medicine II, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Elke Burgermeister
- Department of Medicine II, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- * E-mail:
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Regulated vesicular trafficking of specific PCDH15 and VLGR1 variants in auditory hair cells. J Neurosci 2013; 32:13841-59. [PMID: 23035094 DOI: 10.1523/jneurosci.1242-12.2012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Usher syndrome is a genetically heterogeneous disorder characterized by hearing and balance dysfunction and progressive retinitis pigmentosa. Mouse models carrying mutations for the nine Usher-associated genes have splayed stereocilia, and some show delayed maturation of ribbon synapses suggesting these proteins may play different roles in terminal differentiation of auditory hair cells. The presence of the Usher proteins at the basal and apical aspects of the neurosensory epithelia suggests the existence of regulated trafficking through specific transport proteins and routes. Immature mouse cochleae and UB/OC-1 cells were used in this work to address whether specific variants of PCDH15 and VLGR1 are being selectively transported to opposite poles of the hair cells. Confocal colocalization studies between apical and basal vesicular markers and the different PCDH15 and VLGR1 variants along with sucrose density gradients and the use of vesicle trafficking inhibitors show the existence of Usher protein complexes in at least two vesicular subpools. The apically trafficked pool colocalized with the early endosomal vesicle marker, rab5, while the basally trafficked pool associated with membrane microdomains and SNAP25. Moreover, coimmunoprecipitation experiments between SNAP25 and VLGR1 show a physical interaction of these two proteins in organ of Corti and brain. Collectively, these findings establish the existence of a differential vesicular trafficking mechanism for specific Usher protein variants in mouse cochlear hair cells, with the apical variants playing a potential role in endosomal recycling and stereocilia development/maintenance, and the basolateral variants involved in vesicle docking and/or fusion through SNAP25-mediated interactions.
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Cis-9,trans-11-conjugated linoleic acid affects lipid raft composition and sensitizes human colorectal adenocarcinoma HT-29 cells to X-radiation. Biochim Biophys Acta Gen Subj 2012; 1830:2233-42. [PMID: 23116821 DOI: 10.1016/j.bbagen.2012.10.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 09/29/2012] [Accepted: 10/18/2012] [Indexed: 11/21/2022]
Abstract
BACKGROUND Investigations concerned the mechanism of HT-29 cells radiosensitization by cis-9,trans-11-conjugated linoleic acid (c9,t11-CLA), a natural component of human diet with proven antitumor activity. METHODS The cells were incubated for 24h with 70μM c9,t11-CLA and then X-irradiated. The following methods were used: gas chromatography (incorporation of the CLA isomer), flow cytometry (cell cycle), cloning (survival), Western blotting (protein distribution in membrane fractions), and pulse-field gel electrophoresis (rejoining of DNA double-strand breaks). In parallel, DNA-PK activity, γ-H2AX foci numbers and chromatid fragmentation were estimated. Gene expression was analysed by RT-PCR and chromosomal aberrations by the mFISH method. Nuclear accumulation of the EGF receptor (EGFR) was monitored by ELISA. RESULTS AND CONCLUSIONS C9,t11-CLA sensitized HT-29 cells to X-radiation. This effect was not due to changes in cell cycle progression or DNA-repair-related gene expression. Post-irradiation DSB rejoining was delayed, corresponding with the insufficient DNA-PK activation, although chromosomal aberration frequencies did not increase. Distributions of cholesterol and caveolin-1 in cellular membrane fractions changed. The nuclear EGFR translocation, necessary to increase the DNA-PK activity in response to oxidative stress, was blocked. We suppose that c9,t11-CLA modified the membrane structure, thus disturbing the intracellular EGFR transport and the EGFR-dependent pro-survival signalling, both functionally associated with lipid raft properties. GENERAL SIGNIFICANCE The results point to the importance of the cell membrane interactions with the nucleus after injury inflicted by X -rays. Compounds like c9,t11-CLA, that specifically alter membrane properties, could be used to develop new anticancer strategies.
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Nassoy P, Lamaze C. Stressing caveolae new role in cell mechanics. Trends Cell Biol 2012; 22:381-9. [PMID: 22613354 DOI: 10.1016/j.tcb.2012.04.007] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Revised: 04/16/2012] [Accepted: 04/18/2012] [Indexed: 01/22/2023]
Abstract
It has been almost 60 years since caveolae were first visualized by Eichi Yamada and George Palade. Nevertheless, these specialized invaginations of the plasma membrane remain without clear and recognized physiological function. The recent identification of new caveolar components and the ability to probe cell mechanics with sophisticated opticophysical devices have shed new light on this fascinating organelle. Early studies from the 1970s suggested that caveolae could participate in the regulation of membrane dynamics. Recent data have established caveolae as mechanosensors that respond immediately to mechanical stress by flattening into the plasma membrane. Here, we focus on the molecular consequences that result from the caveolar disassembly/reassembly cycle induced by membrane tension variations at the surface of the cell under physiological and pathological conditions.
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Affiliation(s)
- Pierre Nassoy
- Université P. et M. Curie/CNRS UMR168, 26 rue d'Ulm, 75248 Paris Cedex 05, France
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Abstract
Caveolins (Cavs) are integrated plasma membrane proteins that are complex signaling regulators with numerous partners and whose activity is highly dependent on cellular context. Cavs are both positive and negative regulators of cell signaling in and/or out of caveolae, invaginated lipid raft domains whose formation is caveolin expression dependent. Caveolins and rafts have been implicated in membrane compartmentalization; proteins and lipids accumulate in these membrane microdomains where they transmit fast, amplified and specific signaling cascades. The concept of plasma membrane organization within functional rafts is still in exploration and sometimes questioned. In this chapter, we discuss the opposing functions of caveolin in cell signaling regulation focusing on the role of caveolin both as a promoter and inhibitor of different signaling pathways and on the impact of membrane domain localization on caveolin functionality in cell proliferation, survival, apoptosis and migration.
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42
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Zheng YZ, Boscher C, Inder KL, Fairbank M, Loo D, Hill MM, Nabi IR, Foster LJ. Differential impact of caveolae and caveolin-1 scaffolds on the membrane raft proteome. Mol Cell Proteomics 2011; 10:M110.007146. [PMID: 21753190 PMCID: PMC3205860 DOI: 10.1074/mcp.m110.007146] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Caveolae, a class of cholesterol-rich lipid rafts, are smooth invaginations of the plasma membrane whose formation in nonmuscle cells requires caveolin-1 (Cav1). The recent demonstration that Cav1-associated cavin proteins, in particular PTRF/cavin-1, are also required for caveolae formation supports a functional role for Cav1 independently of caveolae. In tumor cells deficient for Golgi β-1,6N-acetylglucosaminyltransferase V (Mgat5), reduced Cav1 expression is associated not with caveolae but with oligomerized Cav1 domains, or scaffolds, that functionally regulate receptor signaling and raft-dependent endocytosis. Using subdiffraction-limit microscopy, we show that Cav1 scaffolds are homogenous subdiffraction-limit sized structures whose size distribution differs from that of Cav1 in caveolae expressing cells. These cell lines displaying differing Cav1/caveolae phenotypes are effective tools for probing the structure and composition of caveolae. Using stable isotope labeling by amino acids in cell culture, we are able to quantitatively distinguish the composition of caveolae from the background of detergent-resistant membrane proteins and show that the presence of caveolae enriches the protein composition of detergent-resistant membrane, including the recruitment of multiple heterotrimeric G-protein subunits. These data were further supported by analysis of immuno-isolated Cav1 domains and of methyl-β-cyclodextrin-disrupted detergent-resistant membrane. Our data show that loss of caveolae results in a dramatic change to the membrane raft proteome and that this change is independent of Cav1 expression. The proteomics data, in combination with subdiffraction-limit microscopy, indicates that noncaveolar Cav1 domains, or scaffolds are structurally and functionally distinct from caveolae and differentially impact on the molecular composition of lipid rafts.
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Affiliation(s)
- Yu Zi Zheng
- Centre for High-Throughput Biology and Department of Biochemistry and Molecular Biology, 2125 East Mall, University of British Columbia, Vancouver, BC, Canada
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Hoffmann C, Ohlsen K, Hauck CR. Integrin-mediated uptake of fibronectin-binding bacteria. Eur J Cell Biol 2011; 90:891-6. [PMID: 21561684 DOI: 10.1016/j.ejcb.2011.03.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 02/23/2011] [Accepted: 03/08/2011] [Indexed: 10/18/2022] Open
Abstract
Invasion of mammalian cells via cell adhesion molecules of the integrin family is a common theme in bacterial pathogenesis. Whereas some microorganisms directly bind to integrins, other pathogens such as Staphylococcus aureus indirectly engage these receptors via fibronectin-binding proteins (FnBPs). In this review, we summarize the structure-function relationship of FnBPs and the current view of the role of these proteins during pathogenesis in vivo. A major focus will be on recent findings on the role of cholesterol- and sphingolipid-rich membrane microdomains for integrin-initiated uptake of fibronectin-binding bacteria and the surprising inhibitory function of caveolin-1 in this process. The detailed mechanistic understanding of host cell invasion by fibronectin-binding S. aureus can not only serve as a paradigm for other fibronectin-binding pathogenic bacteria, but might also reveal the physiological regulation of endocytosis of ligand-occupied integrins.
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Leborgne-Castel N, Adam T, Bouhidel K. Endocytosis in plant-microbe interactions. PROTOPLASMA 2010; 247:177-93. [PMID: 20814704 DOI: 10.1007/s00709-010-0195-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Accepted: 08/04/2010] [Indexed: 05/10/2023]
Abstract
Plants encounter throughout their life all kinds of microorganisms, such as bacteria, fungi, or oomycetes, with either friendly or unfriendly intentions. During evolution, plants have developed a wide range of defense mechanisms against attackers. In return, adapted microbes have developed strategies to overcome the plant lines of defense, some of these microbes engaging in mutualistic or parasitic endosymbioses. By sensing microbe presence and activating signaling cascades, the plasma membrane through its dynamics plays a crucial role in the ongoing molecular dialogue between plants and microbes. This review describes the contribution of endocytosis to different aspects of plant-microbe interactions, microbe recognition and development of a basal immune response, and colonization of plant cells by endosymbionts. The putative endocytic routes for the entry of microbe molecules or microbes themselves are explored with a special emphasis on clathrin-mediated endocytosis. Finally, we evaluate recent findings that suggest a link between the compartmentalization of plant plasma membrane into microdomains and endocytosis.
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Affiliation(s)
- Nathalie Leborgne-Castel
- UMR Plante-Microbe-Environnement 1088 INRA/5184 CNRS/Université de Bourgogne, 17 Rue Sully, BP 86510, 21065 Dijon Cedex, France.
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Hoffmann C, Berking A, Agerer F, Buntru A, Neske F, Chhatwal GS, Ohlsen K, Hauck CR. Caveolin limits membrane microdomain mobility and integrin-mediated uptake of fibronectin-binding pathogens. J Cell Sci 2010; 123:4280-91. [PMID: 21098633 DOI: 10.1242/jcs.064006] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Staphylococcus aureus, which is a leading cause of hospital-acquired infections, binds via fibronectin to integrin α5β1, a process that can promote host colonization in vivo. Integrin engagement induces actin cytoskeleton rearrangements that result in the uptake of S. aureus by non-professional phagocytic cells. Interestingly, we found that fibronectin-binding S. aureus trigger the redistribution of membrane microdomain components. In particular, ganglioside GM1 and GPI-linked proteins were recruited upon integrin β1 engagement, and disruption of membrane microdomains blocked bacterial internalization. Several membrane-microdomain-associated proteins, such as flotillin-1 and flotillin-2, as well as caveolin, were recruited to sites of bacterial attachment. Whereas dominant-negative versions of flotillin-2 did not affect bacterial attachment or internalization, cells deficient for caveolin-1 (Cav1(-/-)) showed increased uptake of S. aureus and other Fn-binding pathogens. Recruitment of membrane microdomains to cell-associated bacteria was unaltered in Cav1(-/-) cells. However, fluorescence recovery after photobleaching (FRAP) revealed an enhanced mobility of membrane-microdomain-associated proteins in the absence of caveolin-1. Enhanced membrane microdomain mobility and increased uptake of S. aureus was repressed by expression of wild-type caveolin-1, but not caveolin-1 G83S, which harbors a point mutation in the caveolin scaffolding domain. Similarly, chemical or physical stimulation of membrane fluidity led to increased uptake of S. aureus. These results highlight a crucial role for caveolin-1 in negative regulation of membrane microdomain mobility, thereby affecting endocytosis of bacteria-engaged integrins. This process might not only limit host cell invasion by integrin-binding bacterial pathogens, but might also be physiologically relevant for integrin-mediated cell adhesion.
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Affiliation(s)
- Christine Hoffmann
- Lehrstuhl Zellbiologie X908, Universität Konstanz, Universitätsstr. 10, 78457 Konstanz, Germany
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Lin AEJ, Guttman JA. Hijacking the endocytic machinery by microbial pathogens. PROTOPLASMA 2010; 244:75-90. [PMID: 20574860 DOI: 10.1007/s00709-010-0164-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2010] [Accepted: 05/19/2010] [Indexed: 05/24/2023]
Abstract
Understanding the mechanisms that microbes exploit to invade host cells and cause disease is crucial if we are to eliminate their threat. Although pathogens use a variety of microbial factors to trigger entry into non-phagocytic cells, their targeting of the host cell process of endocytosis has emerged as a common theme. To accomplish this, microbes often rewire the normal course of particle internalization, frequently usurping theoretical maximal sizes to permit entry and reconfiguring molecular components that were once thought to be required for vesicle formation. Here, we discuss recent advances in our understanding of how toxins, viruses, bacteria, and fungi manipulate the host cell endocytic machinery to generate diseases. Additionally, we will reveal the advantages of using these organisms to expand our general knowledge of endocytic mechanisms in eukaryotic cells.
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Affiliation(s)
- Ann En-Ju Lin
- Department of Biological Sciences, Shrum Science Centre, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
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Hansen CG, Nichols BJ. Exploring the caves: cavins, caveolins and caveolae. Trends Cell Biol 2010; 20:177-86. [PMID: 20153650 DOI: 10.1016/j.tcb.2010.01.005] [Citation(s) in RCA: 222] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 01/07/2010] [Accepted: 01/11/2010] [Indexed: 01/29/2023]
Abstract
Caveolae are ampullate (flask-shaped) invaginations that are abundant in the plasma membrane of many mammalian cell types. Although caveolae are implicated in a wide range of processes including endothelial transcytosis, lipid homeostasis and cellular signalling, a detailed molecular picture of many aspects of their function has been elusive. Until recently, the only extensively characterised protein components of caveolae were the caveolins. Recently, data from several laboratories have demonstrated that a family of four related proteins, termed cavins 1-4, plays key roles in caveolar biogenesis and function. Salient properties of the cavin family include their propensity to form complexes with each other and their different but overlapping tissue distribution. This review summarises recent data on the cavins, and sets them in the context of open questions on the construction and function of caveolae. The discovery of cavins implies that caveolae might have unexpectedly diverse structural properties, in accord with the wide range of functions attributed to these 'little caves'.
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Abstract
Endocytosis occurs at the cell surface and involves internalization of the plasma membrane (PM) along with its constituent membrane proteins and lipids. Endocytosis is involved in sampling of the extracellular milieu and also serves to regulate various processes initiated at the cell surface. These include nutrient uptake, signaling from cell-surface receptors, and many other processes essential for cell and tissue functioning in metazoans. It is also central to the maintenance of PM lipid and protein homeostasis. There are multiple means of internalization that operate concurrently, at the cell surface. With advancement in high-resolution visualization techniques, it is now possible to track multiple endocytic cargo at the same time, revealing a remarkable diversity of endocytic processes in a single cell. A combination of live cell imaging and efficient genetic manipulations has also aided in understanding the functional hierarchy of molecular players in these mechanisms of internalization. Here we provide an account of various endocytic routes, their mechanisms of operation and occurrence across phyla.
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Lajoie P, Nabi IR. Lipid Rafts, Caveolae, and Their Endocytosis. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2010; 282:135-63. [DOI: 10.1016/s1937-6448(10)82003-9] [Citation(s) in RCA: 266] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
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Lajoie P, Goetz JG, Dennis JW, Nabi IR. Lattices, rafts, and scaffolds: domain regulation of receptor signaling at the plasma membrane. ACTA ACUST UNITED AC 2009; 185:381-5. [PMID: 19398762 PMCID: PMC2700393 DOI: 10.1083/jcb.200811059] [Citation(s) in RCA: 263] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The plasma membrane is organized into various subdomains of clustered macromolecules. Such domains include adhesive structures (cellular synapses, substrate adhesions, and cell-cell junctions) and membrane invaginations (clathrin-coated pits and caveolae), as well as less well-defined domains such as lipid rafts and lectin-glycoprotein lattices. Domains are organized by specialized scaffold proteins including the intramembranous caveolins, which stabilize lipid raft domains, and the galectins, a family of animal lectins that cross-link glycoproteins forming molecular lattices. We review evidence that these heterogeneous microdomains interact to regulate substratum adhesion and cytokine receptor dynamics at the cell surface.
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Affiliation(s)
- Patrick Lajoie
- Deptartment of Cellular and Physiological Sciences, Life Sciences Institute University of British Columbia, Vancouver, British Columbia, Canada
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