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Li H, Zhang J, Shi Y, Zhao G, Xu H, Cai M, Gao J, Wang H. Mechanism of INSR clustering with insulin activation and resistance revealed by super-resolution imaging. NANOSCALE 2022; 14:7747-7755. [PMID: 35579582 DOI: 10.1039/d2nr01051h] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Insulin receptor (INSR) is a key protein in the INSR signaling pathway and plays a critical role in biological processes, especially in the regulation of glucose homeostasis. Many metabolic diseases are often accompanied by abnormal INSR signaling. However, the specific effector mechanisms regulating insulin resistance and the distribution patterns of INSR during cell membrane activation remain unclear. Here, we investigated the changes in the distribution of INSR during activation using super-resolution imaging. By observing the connection between INSR activation and its distribution, we found that insulin resistance inhibits its receptor clustering. More importantly, we found that INSR has a highly co-localized relationship with the skeletal protein βII-spectrin. Specific knockout of βII-spectrin inhibited the interaction of INSR with GLUT4 and affected the normal metabolism of glucose. Our work elucidates the effects of insulin activation and insulin resistance on INSR distribution and reveals a potential relationship between INSR and cytoskeleton at the single molecule level, which promotes a deeper understanding of the roles associated with insulin signaling and insulin resistance.
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Affiliation(s)
- Hongru Li
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, P. R. China.
- University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China
| | - Jinrui Zhang
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, P. R. China.
| | - Yan Shi
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, P. R. China.
| | - Guanfang Zhao
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, P. R. China.
- University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China
| | - Haijiao Xu
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, P. R. China.
| | - Mingjun Cai
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, P. R. China.
- University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China
| | - Jing Gao
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, P. R. China.
| | - Hongda Wang
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, P. R. China.
- University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China
- Laboratory for Marine Biology and Biotechnology, Qing dao National Laboratory for Marine Science and Technology, Wenhai Road, Aoshanwei, Jimo, Qingdao, Shandong 266237, China
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2
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Johanson TM, Keenan CR, Allan RS. Shedding Structured Light on Molecular Immunity: The Past, Present and Future of Immune Cell Super Resolution Microscopy. Front Immunol 2021; 12:754200. [PMID: 34975842 PMCID: PMC8715013 DOI: 10.3389/fimmu.2021.754200] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 11/23/2021] [Indexed: 12/16/2022] Open
Abstract
In the two decades since the invention of laser-based super resolution microscopy this family of technologies has revolutionised the way life is viewed and understood. Its unparalleled resolution, speed, and accessibility makes super resolution imaging particularly useful in examining the highly complex and dynamic immune system. Here we introduce the super resolution technologies and studies that have already fundamentally changed our understanding of a number of central immunological processes and highlight other immunological puzzles only addressable in super resolution.
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Affiliation(s)
- Timothy M. Johanson
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, Australia
| | - Christine R. Keenan
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, Australia
| | - Rhys S. Allan
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, Australia
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3
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Li M, Yu Y. Innate immune receptor clustering and its role in immune regulation. J Cell Sci 2021; 134:134/4/jcs249318. [PMID: 33597156 DOI: 10.1242/jcs.249318] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The discovery of receptor clustering in the activation of adaptive immune cells has revolutionized our understanding of the physical basis of immune signal transduction. In contrast to the extensive studies of adaptive immune cells, particularly T cells, there is a lesser, but emerging, recognition that the formation of receptor clusters is also a key regulatory mechanism in host-pathogen interactions. Many kinds of innate immune receptors have been found to assemble into nano- or micro-sized domains on the surfaces of cells. The clusters formed between diverse categories of innate immune receptors function as a multi-component apparatus for pathogen detection and immune response regulation. Here, we highlight these pioneering efforts and the outstanding questions that remain to be answered regarding this largely under-explored research topic. We provide a critical analysis of the current literature on the clustering of innate immune receptors. Our emphasis is on studies that draw connections between the phenomenon of receptor clustering and its functional role in innate immune regulation.
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Affiliation(s)
- Miao Li
- Department of Chemistry, Indiana University, Bloomington, IN 47401, USA
| | - Yan Yu
- Department of Chemistry, Indiana University, Bloomington, IN 47401, USA
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4
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Li M, Wang H, Li W, Xu XG, Yu Y. Macrophage activation on "phagocytic synapse" arrays: Spacing of nanoclustered ligands directs TLR1/2 signaling with an intrinsic limit. SCIENCE ADVANCES 2020; 6:eabc8482. [PMID: 33268354 PMCID: PMC7821875 DOI: 10.1126/sciadv.abc8482] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 10/19/2020] [Indexed: 05/02/2023]
Abstract
The activation of Toll-like receptor heterodimer 1/2 (TLR1/2) by microbial components plays a critical role in host immune responses against pathogens. TLR1/2 signaling is sensitive to the chemical structure of ligands, but its dependence on the spatial distribution of ligands on microbial surfaces remains unexplored. Here, we reveal the quantitative relationship between TLR1/2-triggered immune responses and the spacing of ligand clusters by designing an artificial "phagocytic synapse" nanoarray platform to mimic the cell-microbe interface. The ligand spacing dictates the proximity of receptor clusters on the cell surface and consequently the pro-inflammatory responses of macrophages. However, cell responses reach their maximum at small ligand spacings when the receptor nanoclusters become adjacent to one another. Our study demonstrates the feasibility of using spatially patterned ligands to modulate innate immunity. It shows that the receptor clusters of TLR1/2 act as a driver in integrating the spatial cues of ligands into cell-level activation events.
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Affiliation(s)
- Miao Li
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Haomin Wang
- Department of Chemistry, Lehigh University, Bethlehem, PA 18015, USA
| | - Wenqian Li
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Xiaoji G Xu
- Department of Chemistry, Lehigh University, Bethlehem, PA 18015, USA
| | - Yan Yu
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA.
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5
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Nosov G, Kahms M, Klingauf J. The Decade of Super-Resolution Microscopy of the Presynapse. Front Synaptic Neurosci 2020; 12:32. [PMID: 32848695 PMCID: PMC7433402 DOI: 10.3389/fnsyn.2020.00032] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 07/21/2020] [Indexed: 01/05/2023] Open
Abstract
The presynaptic compartment of the chemical synapse is a small, yet extremely complex structure. Considering its size, most methods of optical microscopy are not able to resolve its nanoarchitecture and dynamics. Thus, its ultrastructure could only be studied by electron microscopy. In the last decade, new methods of optical superresolution microscopy have emerged allowing the study of cellular structures and processes at the nanometer scale. While this is a welcome addition to the experimental arsenal, it has necessitated careful analysis and interpretation to ensure the data obtained remains artifact-free. In this article we review the application of nanoscopic techniques to the study of the synapse and the progress made over the last decade with a particular focus on the presynapse. We find to our surprise that progress has been limited, calling for imaging techniques and probes that allow dense labeling, multiplexing, longer imaging times, higher temporal resolution, while at least maintaining the spatial resolution achieved thus far.
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Affiliation(s)
- Georgii Nosov
- Institute of Medical Physics and Biophysics, University of Münster, Münster, Germany.,CIM-IMPRS Graduate Program in Münster, Münster, Germany
| | - Martin Kahms
- Institute of Medical Physics and Biophysics, University of Münster, Münster, Germany
| | - Jurgen Klingauf
- Institute of Medical Physics and Biophysics, University of Münster, Münster, Germany
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6
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Wen L, Fan Z, Mikulski Z, Ley K. Imaging of the immune system - towards a subcellular and molecular understanding. J Cell Sci 2020; 133:133/5/jcs234922. [PMID: 32139598 DOI: 10.1242/jcs.234922] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Immune responses involve many types of leukocytes that traffic to the site of injury, recognize the insult and respond appropriately. Imaging of the immune system involves a set of methods and analytical tools that are used to visualize immune responses at the cellular and molecular level as they occur in real time. We will review recent and emerging technological advances in optical imaging, and their application to understanding the molecular and cellular responses of neutrophils, macrophages and lymphocytes. Optical live-cell imaging provides deep mechanistic insights at the molecular, cellular, tissue and organism levels. Live-cell imaging can capture quantitative information in real time at subcellular resolution with minimal phototoxicity and repeatedly in the same living cells or in accessible tissues of the living organism. Advanced FRET probes allow tracking signaling events in live cells. Light-sheet microscopy allows for deeper tissue penetration in optically clear samples, enriching our understanding of the higher-level organization of the immune response. Super-resolution microscopy offers insights into compartmentalized signaling at a resolution beyond the diffraction limit, approaching single-molecule resolution. This Review provides a current perspective on live-cell imaging in vitro and in vivo with a focus on the assessment of the immune system.
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Affiliation(s)
- Lai Wen
- Laboratory of Inflammation Biology, La Jolla Institute for Immunology, 9420 Athena Circle Drive, La Jolla, CA 92037, USA
| | - Zhichao Fan
- Department of Immunology, School of Medicine, UConn Health, 263 Farmington Avenue, Farmington, CT 06030, USA
| | - Zbigniew Mikulski
- Microscopy Core Facility, La Jolla Institute for Immunology, 9420 Athena Circle Drive, La Jolla, CA 92037, USA
| | - Klaus Ley
- Laboratory of Inflammation Biology, La Jolla Institute for Immunology, 9420 Athena Circle Drive, La Jolla, CA 92037, USA .,Department of Bioengineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
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7
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Badawi Y, Nishimune H. Super-resolution microscopy for analyzing neuromuscular junctions and synapses. Neurosci Lett 2020; 715:134644. [PMID: 31765730 PMCID: PMC6937598 DOI: 10.1016/j.neulet.2019.134644] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 11/20/2019] [Accepted: 11/21/2019] [Indexed: 12/12/2022]
Abstract
Super-resolution microscopy techniques offer subdiffraction limited resolution that is two- to ten-fold improved compared to that offered by conventional confocal microscopy. This breakthrough in resolution for light microscopy has contributed to new findings in neuroscience and synapse biology. This review will focus on the Structured Illumination Microscopy (SIM), Stimulated emission depletion (STED) microscopy, and Stochastic optical reconstruction microscopy (STORM) / Single molecule localization microscopy (SMLM) techniques and compare them for the better understanding of their differences and their suitability for the analysis of synapse biology. In addition, we will discuss a few practical aspects of these microscopic techniques, including resolution, image acquisition speed, multicolor capability, and other advantages and disadvantages. Tips for the improvement of microscopy will be introduced; for example, information resources for recommended dyes, the limitations of multicolor analysis, and capabilities for live imaging. In addition, we will summarize how super-resolution microscopy has been used for analyses of neuromuscular junctions and synapses.
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Affiliation(s)
- Yomna Badawi
- Department of Anatomy and Cell Biology, University of Kansas School of Medicine, Kansas City, KS, 66160, USA
| | - Hiroshi Nishimune
- Department of Anatomy and Cell Biology, University of Kansas School of Medicine, Kansas City, KS, 66160, USA.
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8
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Neumann J, Ziegler K, Gelléri M, Fröhlich-Nowoisky J, Liu F, Bellinghausen I, Schuppan D, Birk U, Pöschl U, Cremer C, Lucas K. Nanoscale distribution of TLR4 on primary human macrophages stimulated with LPS and ATI. NANOSCALE 2019; 11:9769-9779. [PMID: 31066732 DOI: 10.1039/c9nr00943d] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Toll-like receptor 4 (TLR4) plays a crucial role in the recognition of invading pathogens. Upon activation by lipopolysaccharides (LPS), TLR4 is recruited into specific membrane domains and dimerizes. In addition to LPS, TLR4 can be stimulated by wheat amylase-trypsin inhibitors (ATI). ATI are proteins associated with gluten containing grains, whose ingestion promotes intestinal and extraintestinal inflammation. However, the effect of ATI vs. LPS on the membrane distribution of TLR4 at the nanoscale has not been analyzed. In this study, we investigated the effect of LPS and ATI stimulation on the membrane distribution of TLR4 in primary human macrophages using single molecule localization microscopy (SMLM). We found that in unstimulated macrophages the majority of TLR4 molecules are located in clusters, but with donor-dependent variations from ∼51% to ∼75%. Depending on pre-clustering, we found pronounced variations in the fraction of clustered molecules and density of clusters on the membrane upon LPS and ATI stimulation. Although clustering differed greatly among the human donors, we found an almost constant cluster diameter of ∼44 nm for all donors, independent of treatment. Together, our results show donor-dependent but comparable effects between ATI and LPS stimulation on the membrane distribution of TLR4. This may indicate a general mechanism of TLR4 activation in primary human macrophages. Furthermore, our methodology visualizes TLR4 receptor clustering and underlines its functional role as a signaling platform.
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Affiliation(s)
- Jan Neumann
- Multiphase Chemistry Department, Max Planck Institute for Chemistry, Hahn-Meitner-Weg 1, 55128 Mainz, Germany.
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9
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Wijesooriya CS, Nyamekye CKA, Smith EA. Optical Imaging of the Nanoscale Structure and Dynamics of Biological Membranes. Anal Chem 2018; 91:425-440. [DOI: 10.1021/acs.analchem.8b04755] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
| | - Charles K. A. Nyamekye
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
- The Ames Laboratory, U.S. Department of Energy, Ames, Iowa 50011, United States
| | - Emily A. Smith
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
- The Ames Laboratory, U.S. Department of Energy, Ames, Iowa 50011, United States
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10
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Mechanistic insights into GLUT1 activation and clustering revealed by super-resolution imaging. Proc Natl Acad Sci U S A 2018; 115:7033-7038. [PMID: 29915035 DOI: 10.1073/pnas.1803859115] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The glucose transporter GLUT1, a plasma membrane protein that mediates glucose homeostasis in mammalian cells, is responsible for constitutive uptake of glucose into many tissues and organs. Many studies have focused on its vital physiological functions and close relationship with diseases. However, the molecular mechanisms of its activation and transport are not clear, and its detailed distribution pattern on cell membranes also remains unknown. To address these, we first investigated the distribution and assembly of GLUT1 at a nanometer resolution by super-resolution imaging. On HeLa cell membranes, the transporter formed clusters with an average diameter of ∼250 nm, the majority of which were regulated by lipid rafts, as well as being restricted in size by both the cytoskeleton and glycosylation. More importantly, we found that the activation of GLUT1 by azide or MβCD did not increase its membrane expression but induced the decrease of the large clusters. The results suggested that sporadic distribution of GLUT1 may facilitate the transport of glucose, implying a potential association between the distribution and activation. Collectively, our work characterized the clustering distribution of GLUT1 and linked its spatial structural organization to the functions, which would provide insights into the activation mechanism of the transporter.
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11
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Gao J, He L, Shi Y, Cai M, Xu H, Jiang J, Zhang L, Wang H. Cell contact and pressure control of YAP localization and clustering revealed by super-resolution imaging. NANOSCALE 2017; 9:16993-17003. [PMID: 29082393 DOI: 10.1039/c7nr05818g] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Yes-associated protein (YAP) is well known for being an effecter of the Hippo signaling cascade that plays a critical role in organ size control, tumorigenesis, and regeneration. As YAP is a transcriptional coactivator, nuclear accumulation is a crucial determinant of its function. Numerous investigations have provided insights into the regulation of YAP, such as upstream molecules of the Hippo pathway, cell contact inhibition, and mechanical forces. However, detailed information regarding YAP spatial localization and organization in cells remains uncertain, and how mechanical signals control YAP distribution and function is not fully known. Therefore, we used one of the super-resolution imaging techniques, direct stochastic optical reconstruction microscopy (dSTORM), combined with confocal microscopy, to solve these problems. We found that YAP is mainly distributed in clusters in the cells, and that both cell contact and pressure on cell surfaces promote the nuclear-to-cytoplasm translocation of YAP and its phosphorylation, but weaken the clustering of nuclear YAP and its transcriptional activity. Moreover, we found that pressure regulation may be more effective on YAP from cancer cells as compared to normal cells, which could help open a door to target YAP for anticancer drug design.
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Affiliation(s)
- Jing Gao
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5626 Renmin Street, Changchun, Jilin 130022, P.R. China.
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12
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Krüger CL, Zeuner MT, Cottrell GS, Widera D, Heilemann M. Quantitative single-molecule imaging of TLR4 reveals ligand-specific receptor dimerization. Sci Signal 2017; 10:10/503/eaan1308. [DOI: 10.1126/scisignal.aan1308] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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13
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Visualising pattern recognition receptor signalling. Biochem Soc Trans 2017; 45:1077-1085. [PMID: 28842530 DOI: 10.1042/bst20160459] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 07/07/2017] [Accepted: 07/11/2017] [Indexed: 01/20/2023]
Abstract
Signalling by pattern recognition receptors (PRRs) is critical for protecting the host against pathogens. Disruption of these signalling pathways has been implicated in many diseases ranging from infection susceptibility to cancer and autoimmune disease. Understanding how PRRs signal is of critical importance due to their potential as therapeutic targets to ameliorate symptoms of inflammatory diseases. The recent advances in microscopy, such as the discovery of fluorescent proteins and the breaking of the diffraction limit of light, offer a unique opportunity to visualise receptor signalling at a single protein level within living cells. Many different microscopy techniques have been developed and used for dissecting different aspects of PRR signalling pathways. This review will provide an overview of the main microscopy techniques used for dissecting these pathways with a focus on Toll-like receptor and NOD-like receptor signalling.
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14
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Gao J, Chen J, Cai M, Xu H, Jiang J, Tong T, Wang H. Clustered localization of STAT3 during the cell cycle detected by super-resolution fluorescence microscopy. Methods Appl Fluoresc 2017; 5:024004. [DOI: 10.1088/2050-6120/aa6ab5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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15
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Zeuner MT, Krüger CL, Volk K, Bieback K, Cottrell GS, Heilemann M, Widera D. Biased signalling is an essential feature of TLR4 in glioma cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:3084-3095. [PMID: 27669113 DOI: 10.1016/j.bbamcr.2016.09.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 09/21/2016] [Accepted: 09/22/2016] [Indexed: 01/19/2023]
Abstract
A distinct feature of the Toll-like receptor 4 (TLR4) is its ability to trigger both MyD88-dependent and MyD88-independent signalling, culminating in activation of pro-inflammatory NF-κB and/or the antiviral IRF3. Although TLR4 agonists (lipopolysaccharides; LPSs) derived from different bacterial species have different endotoxic activity, the impact of LPS chemotype on the downstream signalling is not fully understood. Notably, different TLR4 agonists exhibit anti-tumoural activity in animal models of glioma, but the underlying molecular mechanisms are largely unknown. Thus, we investigated the impact of LPS chemotype on the signalling events in the human glioma cell line U251. We found that LPS of Escherichia coli origin (LPSEC) leads to NF-κB-biased downstream signalling compared to Salmonella minnesota-derived LPS (LPSSM). Exposure of U251 cells to LPSEC resulted in faster nuclear translocation of the NF-κB subunit p65, higher NF-κB-activity and expression of its targets genes, and higher amount of secreted IL-6 compared to LPSSM. Using super-resolution microscopy we showed that the biased agonism of TLR4 in glioma cells is neither a result of differential regulation of receptor density nor of formation of higher order oligomers. Consistent with previous reports, LPSEC-mediated NF-κB activation led to significantly increased U251 proliferation, whereas LPSSM-induced IRF3 activity negatively influenced their invasiveness. Finally, treatment with methyl-β-cyclodextrin (MCD) selectively increased LPSSM-induced nuclear translocation of p65 and NF-κB activity without affecting IRF3. Our data may explain how TLR4 agonists differently affect glioma cell proliferation and migration.
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Affiliation(s)
- Marie-Theres Zeuner
- Stem Cell Biology and Regenerative Medicine, School of Pharmacy, University of Reading, Reading, United Kingdom
| | - Carmen L Krüger
- Institute of Physical and Theoretical Chemistry, Goethe-University, Frankfurt, Germany
| | - Katharina Volk
- Department of Cell Biology, University of Bielefeld, Bielefeld, Germany
| | - Karen Bieback
- Institute of Transfusion Medicine and Immunology, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Graeme S Cottrell
- Cellular and Molecular Neuroscience, School of Pharmacy, University of Reading, Reading, United Kingdom
| | - Mike Heilemann
- Institute of Physical and Theoretical Chemistry, Goethe-University, Frankfurt, Germany
| | - Darius Widera
- Stem Cell Biology and Regenerative Medicine, School of Pharmacy, University of Reading, Reading, United Kingdom.
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16
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Gao J, Wang F, Chen J, Wang J, Cai M, Xu H, Jiang J, Wang H. Super-resolution imaging of STAT3 cellular clustering during nuclear transport. RSC Adv 2016. [DOI: 10.1039/c6ra09591g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
STAT3 cellular clustering revealed by super-resolution fluorescence microscopy.
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Affiliation(s)
- Jing Gao
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun, China
| | - Feng Wang
- Institute of Immunology
- The First Bethune Hospital Academy of Translational Medicine
- Jilin University
- Changchun, China
| | - Junling Chen
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun, China
- University of Chinese Academy of Sciences
| | - Jianzhong Wang
- School of Computer Science and Information Technology
- Northeast Normal University
- Changchun, China
| | - Mingjun Cai
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun, China
| | - Haijiao Xu
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun, China
| | - Junguang Jiang
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun, China
| | - Hongda Wang
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun, China
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17
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Bachmann M, Fiederling F, Bastmeyer M. Practical limitations of superresolution imaging due to conventional sample preparation revealed by a direct comparison of CLSM, SIM and dSTORM. J Microsc 2015; 262:306-15. [PMID: 26694787 DOI: 10.1111/jmi.12365] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 11/06/2015] [Indexed: 12/13/2022]
Abstract
We evaluate the suitability of conventional sample preparation and labelling methods for two superresolution techniques, structured illumination microscopy and direct stochastic optical reconstruction microscopy, by a comparison to established confocal laser scanning microscopy. We show that SIM is compatible with standard fixation procedures and immunofluorescence labelling protocols and improves resolution by a factor of two compared to confocal laser scanning microscopy. With direct stochastic optical reconstruction microscopy, fluorophores can theoretically be localized with much higher precision. However, in practice, with indirect immunofluorescence labelling density can be insufficient due to the bulky probes to reveal biological structures with high resolution. Fine structures like single actin fibres are in fact resolved with direct stochastic optical reconstruction microscopy when using small affinity probes, but require proper adjustment of the fixation protocol. Finally, by a direct comparison of immunofluorescent and genetic labelling with fluorescent proteins, we show that target morphology in direct stochastic optical reconstruction microscopy data sets can differ significantly depending on the labelling method and the molecular environment of the target.
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Affiliation(s)
- Michael Bachmann
- Zoological Institute, Cell- and Neurobiology, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Felix Fiederling
- Zoological Institute, Cell- and Neurobiology, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Martin Bastmeyer
- Zoological Institute, Cell- and Neurobiology, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.,DFG-Center for Functional Nanostructures (CFN), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
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18
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Anthony S, Carroll-Portillo A, Timlin J. Dynamics and Interactions of Individual Proteins in the Membrane of Single, Living Cells. Methods Mol Biol 2015; 1346:185-207. [PMID: 26542723 DOI: 10.1007/978-1-4939-2987-0_13] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
Total internal reflection fluorescence (TIRF) microscopy is a powerful technique for interrogating protein dynamics in the membranes of living single cells. Receptor-ligand interactions are of particular interest for improving our understanding of cell signaling networks in a variety of applications. Here, we describe methods for fluorescently labeling individual receptors and their ligands, conducting single-molecule TIRF microscopy of receptors and ligands in single, living cells, and importantly, performing image analysis on the resulting time sequence of images to extract quantitative dynamics. While we use Toll-like receptor 4 and its ligand lipopolysaccharide as a specific example, the methods are general and readily extendable to other receptor-ligand systems of importance in cellular biology.
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Affiliation(s)
- Stephen Anthony
- Sandia National Laboratories, Bioenergy and Defense Technologies, 5800, Albuquerque, NM, 87185, USA
| | - Amanda Carroll-Portillo
- Sandia National Laboratories, Bioenergy and Defense Technologies, 5800, Albuquerque, NM, 87185, USA
| | - Jerilyn Timlin
- Sandia National Laboratories, Bioenergy and Defense Technologies, 5800, Albuquerque, NM, 87185, USA.
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Klein DCG, Skjesol A, Kers-Rebel ED, Sherstova T, Sporsheim B, Egeberg KW, Stokke BT, Espevik T, Husebye H. CD14, TLR4 and TRAM Show Different Trafficking Dynamics During LPS Stimulation. Traffic 2015; 16:677-90. [PMID: 25707286 DOI: 10.1111/tra.12274] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Revised: 02/19/2015] [Accepted: 02/20/2015] [Indexed: 12/18/2022]
Abstract
Toll-like receptor 4 (TLR4) is responsible for the immediate response to Gram-negative bacteria and signals via two main pathways by recruitment of distinct pairs of adaptor proteins. Mal-MyD88 [Mal (MyD88-adaptor-like) - MYD88 (Myeloid differentiation primary response gene (88))] is recruited to the plasma membrane to initiate the signaling cascade leading to production of pro-inflammatory cytokines while TRAM-TRIF [TRAM (TRIF-related adaptor molecule)-TRIF (TIR-domain-containing adapter-inducing interferon-β)] is recruited to early endosomes to initiate the subsequent production of type I interferons. We have investigated the dynamics of TLR4 and TRAM during lipopolysaccharide (LPS) stimulation. We found that LPS induced a CD14-dependent immobile fraction of TLR4 in the plasma membrane. Total internal reflection fluorescence microscopy (TIRF) revealed that LPS stimulation induced clustering of TLR4 into small punctate structures in the plasma membrane containing CD14/LPS and clathrin, both in HEK293 cells and the macrophage model cell line U373-CD14. These results suggest that laterally immobilized TLR4 receptor complexes are being formed and prepared for endocytosis. RAB11A was found to be involved in localizing TRAM to the endocytic recycling compartment (ERC) and to early sorting endosomes. Moreover, CD14/LPS but not TRAM was immobilized on RAB11A-positive endosomes, which indicates that TRAM and CD14/LPS can independently be recruited to endosomes.
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Affiliation(s)
- Dionne C G Klein
- Department of Cancer Research and Molecular Medicine, Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway
| | - Astrid Skjesol
- Department of Cancer Research and Molecular Medicine, Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway
| | - Esther D Kers-Rebel
- Graduate School of Life Sciences, University of Utrecht, Utrecht, The Netherlands.,Present address: Radboud university medical center, Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Tatyana Sherstova
- Department of Physics, Norwegian University of Science and Technology, Trondheim, Norway
| | - Bjørnar Sporsheim
- Department of Cancer Research and Molecular Medicine, Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway
| | - Kjartan W Egeberg
- Department of Cancer Research and Molecular Medicine, Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway
| | - Bjørn T Stokke
- Department of Physics, Norwegian University of Science and Technology, Trondheim, Norway
| | - Terje Espevik
- Department of Cancer Research and Molecular Medicine, Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway
| | - Harald Husebye
- Department of Cancer Research and Molecular Medicine, Centre of Molecular Inflammation Research, Norwegian University of Science and Technology, Trondheim, Norway
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20
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Gao J, Wang F, Liu Y, Cai M, Xu H, Jiang J, Wang H. Revealing the cellular localization of STAT1 during the cell cycle by super-resolution imaging. Sci Rep 2015; 5:9045. [PMID: 25762114 PMCID: PMC4356954 DOI: 10.1038/srep09045] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 02/16/2015] [Indexed: 01/30/2023] Open
Abstract
Signal transducers and activators of transcription (STATs) can transduce cytokine signals and regulate gene expression. The cellular localization and nuclear trafficking of STAT1, a representative of the STAT family with multiple transcriptional functions, is tightly related with transcription process, which usually happens in the interphase of the cell cycle. However, these priority questions regarding STAT1 distribution and localization at the different cell-cycle stages remain unclear. By using direct stochastic optical reconstruction microscopy (dSTORM), we found that the nuclear expression level of STAT1 increased gradually as the cell cycle carried out, especially after EGF stimulation. Furthermore, STAT1 formed clusters in the whole cell during the cell cycle, with the size and the number of clusters also increasing significantly from G1 to G2 phase, suggesting that transcription and other cell-cycle related activities can promote STAT1 to form more and larger clusters for fast response to signals. Our work reveals that the cellular localization and clustering distribution of STAT1 are associated with the cell cycle, and further provides an insight into the mechanism of cell-cycle regulated STAT1 signal transduction.
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Affiliation(s)
- Jing Gao
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, China
- Graduate University of Chinese Academy of Sciences, Beijing, China
| | - Feng Wang
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, China
| | - Yanhou Liu
- Institute of Immunology, The First Bethune Hospital Academy of Translational Medicine, Jilin University, Changchun, Jilin, China
| | - Mingjun Cai
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, China
| | - Haijiao Xu
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, China
| | - Junguang Jiang
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, China
| | - Hongda Wang
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, China
- Graduate University of Chinese Academy of Sciences, Beijing, China
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21
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Gao J, Wang Y, Cai M, Pan Y, Xu H, Jiang J, Ji H, Wang H. Mechanistic insights into EGFR membrane clustering revealed by super-resolution imaging. NANOSCALE 2015; 7:2511-9. [PMID: 25569174 DOI: 10.1039/c4nr04962d] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The clustering of membrane receptors such as EGFR is critical for various biological processes, for example cell signaling and tumorigenesis. However, the mechanism involved remains poorly understood. Here, we used a super resolution imaging technique, which has shattered the longstanding resolution barrier of light diffraction, to investigate the distribution of membrane EGFR on apical or basal surfaces of COS-7 cells and on the surface of suspended COS-7 cells. Our data show that more and larger EGFR clusters are detected on the apical surface in comparison with those on the basal surface and this difference is not affected by the EGFR activation state, whereas suspended COS-7 cells exhibit a moderate clustering state and a homogeneous distribution pattern, indicating that the external environment surrounding the cell membrane is the decisive factor in the EGFR clustering pattern. A dual-color dSTORM image reveals the significant colocalization of EGFR and lipid rafts; interestingly MβCD treatment leads to a dramatic decrease of the amount and size of EGFR clusters on both apical and basal surfaces, highlighting a key role of lipid rafts in EGFR cluster formation. Altogether, our results illustrate the distribution pattern of EGFR in polarized cells and uncover the essential role of lipid rafts in EGFR cluster maintenance.
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Affiliation(s)
- Jing Gao
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P.R. China.
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22
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Pi J, Jin H, Yang F, Chen ZW, Cai J. In situ single molecule imaging of cell membranes: linking basic nanotechniques to cell biology, immunology and medicine. NANOSCALE 2014; 6:12229-12249. [PMID: 25227707 DOI: 10.1039/c4nr04195j] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The cell membrane, which consists of a viscous phospholipid bilayer, different kinds of proteins and various nano/micrometer-sized domains, plays a very important role in ensuring the stability of the intracellular environment and the order of cellular signal transductions. Exploring the precise cell membrane structure and detailed functions of the biomolecules in a cell membrane would be helpful to understand the underlying mechanisms involved in cell membrane signal transductions, which could further benefit research into cell biology, immunology and medicine. The detection of membrane biomolecules at the single molecule level can provide some subtle information about the molecular structure and the functions of the cell membrane. In particular, information obtained about the molecular mechanisms and other information at the single molecule level are significantly different from that detected from a large amount of biomolecules at the large-scale through traditional techniques, and can thus provide a novel perspective for the study of cell membrane structures and functions. However, the precise investigations of membrane biomolecules prompts researchers to explore cell membranes at the single molecule level by the use of in situ imaging methods, as the exact conformation and functions of biomolecules are highly controlled by the native cellular environment. Recently, the in situ single molecule imaging of cell membranes has attracted increasing attention from cell biologists and immunologists. The size of biomolecules and their clusters on the cell surface are set at the nanoscale, which makes it mandatory to use high- and super-resolution imaging techniques to realize the in situ single molecule imaging of cell membranes. In the past few decades, some amazing imaging techniques and instruments with super resolution have been widely developed for molecule imaging, which can also be further employed for the in situ single molecule imaging of cell membranes. In this review, we attempt to summarize the characteristics of these advanced techniques for use in the in situ single molecule imaging of cell membranes. We believe that this work will help to promote the technological and methodological developments of super-resolution techniques for the single molecule imaging of cell membranes and help researchers better understand which technique is most suitable for their future exploring of membrane biomolecules; ultimately promoting further developments in cell biology, immunology and medicine.
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Affiliation(s)
- Jiang Pi
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technique, Macau, China.
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23
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Wang Y, Gao J, Guo X, Tong T, Shi X, Li L, Qi M, Wang Y, Cai M, Jiang J, Xu C, Ji H, Wang H. Regulation of EGFR nanocluster formation by ionic protein-lipid interaction. Cell Res 2014; 24:959-76. [PMID: 25001389 PMCID: PMC4123299 DOI: 10.1038/cr.2014.89] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 05/06/2014] [Accepted: 06/03/2014] [Indexed: 12/24/2022] Open
Abstract
The abnormal activation of epidermal growth factor receptor (EGFR) is strongly associated with a variety of human cancers but the underlying molecular mechanism is not fully understood. By using direct stochastic optical reconstruction microscopy (dSTORM), we find that EGFR proteins form nanoclusters in the cell membrane of both normal lung epithelial cells and lung cancer cells, but the number and size of clusters significantly increase in lung cancer cells. The formation of EGFR clusters is mediated by the ionic interaction between the anionic lipid phosphatidylinositol-4,5-bisphosphate (PIP2) in the plasma membrane and the juxtamembrane (JM) region of EGFR. Disruption of EGFR clustering by PIP2 depletion or JM region mutation impairs EGFR activation and downstream signaling. Furthermore, JM region mutation in constitutively active EGFR mutant attenuates its capability of cell transformation. Collectively, our findings highlight the key roles of anionic phospholipids in EGFR signaling and function, and reveal a novel mechanism to explain the aberrant activation of EGFR in cancers.
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Affiliation(s)
- Ye Wang
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Jing Gao
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xingdong Guo
- National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Ti Tong
- Department of Thoracic Surgery, The Second Hospital of Jilin University, Changchun, Jilin 130041, China
| | - Xiaoshan Shi
- National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Lunyi Li
- National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Miao Qi
- School of Computer Science and Information Technology, Northeast Normal University, Changchun, Jilin 130117, China
| | - Yajie Wang
- Department of Oncology, Changhai Hospital, Second Military Medical University, Shanghai 200433, China
| | - Mingjun Cai
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China
| | - Junguang Jiang
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China
| | - Chenqi Xu
- National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Hongbin Ji
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Hongda Wang
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China
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Truong-Quang BA, Lenne PF. Membrane microdomains: from seeing to understanding. FRONTIERS IN PLANT SCIENCE 2014; 5:18. [PMID: 24600455 PMCID: PMC3927121 DOI: 10.3389/fpls.2014.00018] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 01/15/2014] [Indexed: 05/08/2023]
Abstract
The plasma membrane is a composite material, which forms a semi-permeable barrier and an interface for communication between the intracellular and extracellular environments. While the existence of membrane microdomains with nanoscale organization has been proved by the application of numerous biochemical and physical methods, direct observation of these heterogeneities using optical microscopy has remained challenging for decades, partly due to the optical diffraction limit, which restricts the resolution to ~200 nm. During the past years, new optical methods which circumvent this fundamental limit have emerged. Not only do these techniques allow direct visualization, but also quantitative characterization of nanoscopic structures. We discuss how these emerging optical methods have refined our knowledge of membrane microdomains and how they may shed light on the basic principles of the mesoscopic membrane organization.
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Affiliation(s)
| | - Pierre-François Lenne
- *Correspondence: Pierre-François Lenne, Developmental Biology Institute of Marseilles, UMR 7288 CNRS, Aix-Marseille Université, 13288 Marseille Cedex 9, France e-mail:
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25
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Wu J, Gao J, Qi M, Wang J, Cai M, Liu S, Hao X, Jiang J, Wang H. High-efficiency localization of Na(+)-K(+) ATPases on the cytoplasmic side by direct stochastic optical reconstruction microscopy. NANOSCALE 2013; 5:11582-6. [PMID: 24113832 DOI: 10.1039/c3nr03665k] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We describe a concise and effective strategy towards precisely mapping Na(+)-K(+) ATPases on the cytoplasmic side of cell membranes by direct stochastic optical reconstruction microscopy (dSTORM). We found that most Na(+)-K(+) ATPases are localized in different sizes of clusters on human red blood cell (hRBC) membranes, revealed by Ripley's K-function analysis. Further evidence that cholesterol depletion causes the dispersion of Na(+)-K(+) ATPase clusters indicates that such clusters could be localized in cholesterol-enriched domains. Our results suggest that Na(+)-K(+) ATPases might aggregate within the lipid rafts to fulfill their functions.
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Affiliation(s)
- Jiazhen Wu
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P.R. China.
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