1
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Raykhel I, Ronkainen VP, Myllyharju J, Manninen A. HIF2α-dependent Dock4/Rac1-signaling regulates formation of adherens junctions and cell polarity in normoxia. Sci Rep 2024; 14:12153. [PMID: 38802496 PMCID: PMC11130225 DOI: 10.1038/s41598-024-62955-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 05/23/2024] [Indexed: 05/29/2024] Open
Abstract
Hypoxia-inducible factors (HIF) 1 and 2 regulate similar but distinct sets of target genes. Although HIFs are best known for their roles in mediating the hypoxia response accumulating evidence suggests that under certain conditions HIFs, particularly HIF2, may function also under normoxic conditions. Here we report that HIF2α functions under normoxic conditions in kidney epithelial cells to regulate formation of adherens junctions. HIF2α expression was required to induce Dock4/Rac1/Pak1-signaling mediating stability and compaction of E-cadherin at nascent adherens junctions. Impaired adherens junction formation in HIF2α- or Dock4-deficient cells led to aberrant cyst morphogenesis in 3D kidney epithelial cell cultures. Taken together, we show that HIF2α functions in normoxia to regulate epithelial morphogenesis.
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Affiliation(s)
- I Raykhel
- Disease Networks Research Unit, Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland
- Extracellular Matrix and Hypoxia Research Unit, Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland
| | - V-P Ronkainen
- Extracellular Matrix and Hypoxia Research Unit, Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland
| | - J Myllyharju
- Extracellular Matrix and Hypoxia Research Unit, Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland.
| | - A Manninen
- Disease Networks Research Unit, Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland.
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2
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Cruz SP, Zhang Q, Devarajan R, Paia C, Luo B, Zhang K, Koivusalo S, Qin L, Xia J, Ahtikoski A, Vaarala M, Wenta T, Wei G, Manninen A. Dampened Regulatory Circuitry of TEAD1/ITGA1/ITGA2 Promotes TGFβ1 Signaling to Orchestrate Prostate Cancer Progression. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2305547. [PMID: 38169150 PMCID: PMC10953553 DOI: 10.1002/advs.202305547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 12/18/2023] [Indexed: 01/05/2024]
Abstract
The extracellular matrix (ECM) undergoes substantial changes during prostate cancer (PCa) progression, thereby regulating PCa growth and invasion. Herein, a meta-analysis of multiple PCa cohorts is performed which revealed that downregulation or genomic loss of ITGA1 and ITGA2 integrin genes is associated with tumor progression and worse prognosis. Genomic deletion of both ITGA1 and ITGA2 activated epithelial-to-mesenchymal transition (EMT) in benign prostate epithelial cells, thereby enhancing their invasive potential in vitro and converting them into tumorigenic cells in vivo. Mechanistically, EMT is induced by enhanced secretion and autocrine activation of TGFβ1 and nuclear targeting of YAP1. An unbiased genome-wide co-expression analysis of large PCa cohort datasets identified the transcription factor TEAD1 as a key regulator of ITGA1 and ITGA2 expression in PCa cells while TEAD1 loss phenocopied the dual loss of α1- and α2-integrins in vitro and in vivo. Remarkably, clinical data analysis revealed that TEAD1 downregulation or genomic loss is associated with aggressive PCa and together with low ITGA1 and ITGA2 expression synergistically impacted PCa prognosis and progression. This study thus demonstrated that loss of α1- and α2-integrins, either via deletion/inactivation of the ITGA1/ITGA2 locus or via loss of TEAD1, contributes to PCa progression by inducing TGFβ1-driven EMT.
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Affiliation(s)
- Sara P. Cruz
- Disease Networks Research Unit, Faculty of Biochemistry and Molecular Medicine, Biocenter OuluUniversity of OuluAapistie 5aOulu90220Finland
| | - Qin Zhang
- Disease Networks Research Unit, Faculty of Biochemistry and Molecular Medicine, Biocenter OuluUniversity of OuluAapistie 5aOulu90220Finland
| | - Raman Devarajan
- Disease Networks Research Unit, Faculty of Biochemistry and Molecular Medicine, Biocenter OuluUniversity of OuluAapistie 5aOulu90220Finland
| | - Christos Paia
- Disease Networks Research Unit, Faculty of Biochemistry and Molecular Medicine, Biocenter OuluUniversity of OuluAapistie 5aOulu90220Finland
| | - Binjie Luo
- Disease Networks Research Unit, Faculty of Biochemistry and Molecular Medicine, Biocenter OuluUniversity of OuluAapistie 5aOulu90220Finland
| | - Kai Zhang
- Disease Networks Research Unit, Faculty of Biochemistry and Molecular Medicine, Biocenter OuluUniversity of OuluAapistie 5aOulu90220Finland
| | - Saara Koivusalo
- Disease Networks Research Unit, Faculty of Biochemistry and Molecular Medicine, Biocenter OuluUniversity of OuluAapistie 5aOulu90220Finland
| | - Longguang Qin
- Disease Networks Research Unit, Faculty of Biochemistry and Molecular Medicine, Biocenter OuluUniversity of OuluAapistie 5aOulu90220Finland
| | - Jihan Xia
- Disease Networks Research Unit, Faculty of Biochemistry and Molecular Medicine, Biocenter OuluUniversity of OuluAapistie 5aOulu90220Finland
| | - Anne Ahtikoski
- Departments of Urology, Pathology and Radiology, and Medical Research Center OuluOulu University Hospital and University of OuluAapistie 5aOulu90220Finland
| | - Markku Vaarala
- Departments of Urology, Pathology and Radiology, and Medical Research Center OuluOulu University Hospital and University of OuluAapistie 5aOulu90220Finland
| | - Tomasz Wenta
- Disease Networks Research Unit, Faculty of Biochemistry and Molecular Medicine, Biocenter OuluUniversity of OuluAapistie 5aOulu90220Finland
- Department of General and Medical Biochemistry, Faculty of BiologyUniversity of GdanskJana Bażyńskiego 8Gdańsk80–309Poland
| | - Gong‐Hong Wei
- Disease Networks Research Unit, Faculty of Biochemistry and Molecular Medicine, Biocenter OuluUniversity of OuluAapistie 5aOulu90220Finland
- Fudan University Shanghai Cancer Center & MOE Key Laboratory of Metabolism and Molecular Medicine and Department of Biochemistry and Molecular Biology of School of Basic Medical SciencesShanghai Medical College of Fudan University138 Yi Xue Yuan RoadShanghai200032China
| | - Aki Manninen
- Disease Networks Research Unit, Faculty of Biochemistry and Molecular Medicine, Biocenter OuluUniversity of OuluAapistie 5aOulu90220Finland
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3
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The Lectin LecB Induces Patches with Basolateral Characteristics at the Apical Membrane to Promote Pseudomonas aeruginosa Host Cell Invasion. mBio 2022; 13:e0081922. [PMID: 35491830 PMCID: PMC9239240 DOI: 10.1128/mbio.00819-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The opportunistic bacterium Pseudomonas aeruginosa can infect mucosal tissues of the human body. To persist at the mucosal barrier, this highly adaptable pathogen has evolved many strategies, including invasion of host cells. Here, we show that the P. aeruginosa lectin LecB binds and cross-links fucosylated receptors at the apical plasma membrane of epithelial cells. This triggers a signaling cascade via Src kinases and phosphoinositide 3-kinase (PI3K), leading to the formation of patches enriched with the basolateral marker phosphatidylinositol (3,4,5)-trisphosphate (PIP3) at the apical plasma membrane. This identifies LecB as a causative bacterial factor for activating this well-known host cell response that is elicited upon apical binding of P. aeruginosa. Downstream from PI3K, Rac1 is activated to cause actin rearrangement and the outgrowth of protrusions at the apical plasma membrane. LecB-triggered PI3K activation also results in aberrant recruitment of caveolin-1 to the apical domain. In addition, we reveal a positive feedback loop between PI3K activation and apical caveolin-1 recruitment, which provides a mechanistic explanation for the previously observed implication of caveolin-1 in P. aeruginosa host cell invasion. Interestingly, LecB treatment also reversibly removes primary cilia. To directly prove the role of LecB for bacterial uptake, we coated bacterium-sized beads with LecB, which drastically enhanced their endocytosis. Furthermore, LecB deletion and LecB inhibition with l-fucose diminished the invasion efficiency of P. aeruginosa bacteria. Taken together, the results of our study identify LecB as a missing link that can explain how PI3K signaling and caveolin-1 recruitment are triggered to facilitate invasion of epithelial cells from the apical side by P. aeruginosa.
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4
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Exner T, Beretta CA, Gao Q, Afting C, Romero-Brey I, Bartenschlager R, Fehring L, Poppelreuther M, Füllekrug J. Lipid droplet quantification based on iterative image processing. J Lipid Res 2019; 60:1333-1344. [PMID: 30926625 DOI: 10.1194/jlr.d092841] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 03/28/2019] [Indexed: 12/15/2022] Open
Abstract
Lipid droplets (LDs) are ubiquitous and highly dynamic subcellular organelles required for the storage of neutral lipids. LD number and size distribution are key parameters affected not only by nutrient supply but also by lipotoxic stress and metabolic regulation. Current methods for LD quantification lack general applicability and are either based on time consuming manual evaluation or show limitations if LDs are high in numbers or closely clustered. Here, we present an ImageJ-based approach for the detection and quantification of LDs stained by neutral lipid dyes in images acquired by conventional wide-field fluorescence microscopy. The method features an adjustable preprocessing procedure that resolves LD clusters. LD identification is based on their circular edges and central fluorescence intensity maxima. Adaptation to different cell types is mediated by a set of interactive parameters. Validation was done for three different cell lines using manual evaluation of LD numbers and volume measurement by 3D rendering of confocal datasets. In an application example, we show that overexpression of the acyl-CoA synthetase, FATP4/ACSVL5, in oleate-treated COS7 cells increased the size of LDs but not their number.
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Affiliation(s)
- Tarik Exner
- Molecular Cell Biology Laboratory Internal Medicine IV, Heidelberg University, Heidelberg, Germany
| | - Carlo A Beretta
- CellNetworks Math-Clinic Core Facility, BioQuant Heidelberg University, Heidelberg, Germany
| | - Qi Gao
- CellNetworks Math-Clinic Core Facility, BioQuant Heidelberg University, Heidelberg, Germany
| | - Cassian Afting
- Molecular Cell Biology Laboratory Internal Medicine IV, Heidelberg University, Heidelberg, Germany
| | - Inés Romero-Brey
- Department of Infectious Diseases, Molecular Virology Heidelberg University, Heidelberg, Germany
| | - Ralf Bartenschlager
- Department of Infectious Diseases, Molecular Virology Heidelberg University, Heidelberg, Germany.,Department of Virus-Associated Carcinogenesis, German Cancer Research Center, Heidelberg, Germany
| | - Leonard Fehring
- Molecular Cell Biology Laboratory Internal Medicine IV, Heidelberg University, Heidelberg, Germany
| | - Margarete Poppelreuther
- Molecular Cell Biology Laboratory Internal Medicine IV, Heidelberg University, Heidelberg, Germany
| | - Joachim Füllekrug
- Molecular Cell Biology Laboratory Internal Medicine IV, Heidelberg University, Heidelberg, Germany
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5
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Exner T, Romero-Brey I, Yifrach E, Rivera-Monroy J, Schrul B, Zouboulis CC, Stremmel W, Honsho M, Bartenschlager R, Zalckvar E, Poppelreuther M, Füllekrug J. An alternative membrane topology permits lipid droplet localization of peroxisomal fatty acyl-CoA reductase 1. J Cell Sci 2019; 132:jcs.223016. [PMID: 30745342 DOI: 10.1242/jcs.223016] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 02/01/2019] [Indexed: 01/02/2023] Open
Abstract
Fatty acyl-CoA reductase 1 (Far1) is a ubiquitously expressed peroxisomal membrane protein that generates the fatty alcohols required for the biosynthesis of ether lipids. Lipid droplet localization of exogenously expressed and endogenous human Far1 was observed by fluorescence microscopy under conditions of increased triglyceride synthesis in tissue culture cells. This unexpected finding was supported further by correlative light electron microscopy and subcellular fractionation. Selective permeabilization, protease sensitivity and N-glycosylation tagging suggested that Far1 is able to assume two different membrane topologies, differing in the orientation of the short hydrophilic C-terminus towards the lumen or the cytosol, respectively. Two closely spaced hydrophobic domains are contained within the C-terminal region. When analyzed separately, the second domain was sufficient for the localization of a fluorescent reporter to lipid droplets. Targeting of Far1 to lipid droplets was not impaired in either Pex19 or ASNA1 (also known as TRC40) CRISPR/Cas9 knockout cells. In conclusion, our data suggest that Far1 is a novel member of the rather exclusive group of dual topology membrane proteins. At the same time, Far1 shows lipid metabolism-dependent differential subcellular localizations to peroxisomes and lipid droplets.
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Affiliation(s)
- Tarik Exner
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, 69120 Heidelberg, Germany
| | - Inés Romero-Brey
- Department of Infectious Diseases, Molecular Virology, University of Heidelberg, 69120 Heidelberg, Germany
| | - Eden Yifrach
- Department of Molecular Genetics, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Jhon Rivera-Monroy
- Department of Molecular Biology, University Medical Center Göttingen, 37077 Göttingen, Germany
| | - Bianca Schrul
- Medical Biochemistry and Molecular Biology, Center for Molecular Signaling (PZMS), Saarland University, 66421 Homburg/Saar, Germany
| | - Christos C Zouboulis
- Departments of Dermatology, Venereology, Allergology and Immunology, Dessau Medical Center, Brandenburg Medical School Theodor Fontane, 06847 Dessau, Germany
| | - Wolfgang Stremmel
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, 69120 Heidelberg, Germany
| | - Masanori Honsho
- Medical Institute of Bioregulation, Kyushu University, 812-8582 Fukuoka, Japan
| | - Ralf Bartenschlager
- Department of Infectious Diseases, Molecular Virology, University of Heidelberg, 69120 Heidelberg, Germany
| | - Einat Zalckvar
- Department of Molecular Genetics, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Margarete Poppelreuther
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, 69120 Heidelberg, Germany
| | - Joachim Füllekrug
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, 69120 Heidelberg, Germany
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6
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Raykhel I, Moafi F, Myllymäki SM, Greciano PG, Matlin KS, Moyano JV, Manninen A, Myllyharju J. BAMBI is a novel HIF1-dependent modulator of TGFβ-mediated disruption of cell polarity during hypoxia. J Cell Sci 2018; 131:jcs.210906. [PMID: 29685894 DOI: 10.1242/jcs.210906] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 04/17/2018] [Indexed: 12/19/2022] Open
Abstract
Hypoxia and loss of cell polarity are common features of malignant carcinomas. Hypoxia-inducible factor 1 (HIF1) is the major regulator of cellular hypoxia response and mediates the activation of ∼300 genes. Increased HIF1 signaling is known to be associated with epithelial-mesenchymal transformation. Here, we report that hypoxia disrupts polarized epithelial morphogenesis of MDCK cells in a HIF1α-dependent manner by modulating the transforming growth factor-β (TGFβ) signaling pathway. Analysis of potential HIF1 targets in the TGFβ pathway identified the bone morphogenetic protein and activin membrane-bound inhibitor (BAMBI), a transmembrane glycoprotein related to the type I receptors of the TGFβ family, whose expression was essentially lost in HIF1-depleted cells. Similar to what was observed in HIF1-deficient cells, BAMBI-depleted cells failed to efficiently activate TGFβ signaling and retained epithelial polarity during hypoxia. Taken together, we show that hypoxic conditions promote TGFβ signaling in a HIF1-dependent manner and BAMBI is identified in this pathway as a novel HIF1-regulated gene that contributes to hypoxia-induced loss of epithelial polarity.
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Affiliation(s)
- Irina Raykhel
- Oulu Center for Cell-Matrix Research, Biocenter Oulu, Faculty of Biochemistry and Molecular Medicine, University of Oulu, 90220 Oulu, Finland
| | - Fazeh Moafi
- Oulu Center for Cell-Matrix Research, Biocenter Oulu, Faculty of Biochemistry and Molecular Medicine, University of Oulu, 90220 Oulu, Finland
| | - Satu M Myllymäki
- Oulu Center for Cell-Matrix Research, Biocenter Oulu, Faculty of Biochemistry and Molecular Medicine, University of Oulu, 90220 Oulu, Finland
| | - Patricia G Greciano
- Department of Surgery (Section of Research), University of Chicago, Chicago, IL 60637-1470, USA
| | - Karl S Matlin
- Department of Surgery (Section of Research), University of Chicago, Chicago, IL 60637-1470, USA
| | - Jose V Moyano
- Department of Surgery (Section of Research), University of Chicago, Chicago, IL 60637-1470, USA
| | - Aki Manninen
- Oulu Center for Cell-Matrix Research, Biocenter Oulu, Faculty of Biochemistry and Molecular Medicine, University of Oulu, 90220 Oulu, Finland
| | - Johanna Myllyharju
- Oulu Center for Cell-Matrix Research, Biocenter Oulu, Faculty of Biochemistry and Molecular Medicine, University of Oulu, 90220 Oulu, Finland
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7
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Poppelreuther M, Sander S, Minden F, Dietz MS, Exner T, Du C, Zhang I, Ehehalt F, Knüppel L, Domschke S, Badenhop A, Staudacher S, Ehehalt R, Stremmel W, Thiele C, Heilemann M, Füllekrug J. The metabolic capacity of lipid droplet localized acyl-CoA synthetase 3 is not sufficient to support local triglyceride synthesis independent of the endoplasmic reticulum in A431 cells. Biochim Biophys Acta Mol Cell Biol Lipids 2018. [PMID: 29526665 DOI: 10.1016/j.bbalip.2018.03.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
ACSL3 is the only long chain fatty acyl-CoA synthetase consistently found on growing and mature lipid droplets (LDs), suggesting that this specific localization has biological relevance. Current models for LD growth propose that triglycerides are synthesized by enzymes at the LD surface, with activated fatty acids provided by LD localized ACSL3, thus allowing growth independent of the ER. Here, we tested this hypothesis by quantifying ACSL3 on LDs from human A431 cells. RNAi of ACSL3 reduced the oleoyl-CoA synthetase activity by 83%, suggesting that ACSL3 is by far the dominant enzyme of A431 cells. Molar quantification revealed that there are 1.4 million ACSL3 molecules within a single cell. Metabolic labeling indicated that each ACSL3 molecule contributed a net gain of 3.1 oleoyl-CoA/s. 3D reconstruction of confocal images demonstrated that 530 individual lipid droplets were present in an average oleate fed A431 cell. A representative single lipid droplet with a diameter of 0.66 μm contained 680 ACSL3 molecules on the surface. Subcellular fractionation showed that at least 68% of ACSL3 remain at the ER even during extensive fatty acid supplementation. High resolution single molecule microscopy confirmed the abundance of cytoplasmic ACSL3 outside of LDs. Model calculations for triglyceride synthesis using only LD localized ACSL3 gave significant slower growth of LDs as observed experimentally. In conclusion, although ACSL3 is an abundant enzyme on A431 LDs, the metabolic capacity is not sufficient to account for LD growth solely by the local synthesis of triglycerides.
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Affiliation(s)
| | - Simone Sander
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Fadil Minden
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Marina S Dietz
- Institute for Physical and Theoretical Chemistry, Goethe-University Frankfurt, Germany
| | - Tarik Exner
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Chen Du
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Ingrid Zhang
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Friedrich Ehehalt
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Laura Knüppel
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Susanne Domschke
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Anna Badenhop
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Sarah Staudacher
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Robert Ehehalt
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Wolfgang Stremmel
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany
| | - Christoph Thiele
- Life and Medical Sciences Institute, University of Bonn, Germany
| | - Mike Heilemann
- Institute for Physical and Theoretical Chemistry, Goethe-University Frankfurt, Germany
| | - Joachim Füllekrug
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany.
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8
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Xing X, Pan Y, Yobas L. A Low-Backpressure Single-Cell Point Constriction for Cytosolic Delivery Based on Rapid Membrane Deformations. Anal Chem 2018; 90:1836-1844. [PMID: 29308899 DOI: 10.1021/acs.analchem.7b03864] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Mechanically deforming biological cells through microfluidic constrictions is a recently introduced technique for the intracellular delivery of macromolecules possibly through transient membrane pores induced in the process. The technique is attractive for research and clinical applications mainly because it is simple, fast, and effective while being free of adverse effects often associated with well-known techniques that rely on field- or vector-based delivery. In this nascent approach, an utmost and crucial role is played by the constriction, often in rectangular profile, and it squeezes cells only in one dimension. The results achieved suggest that the longer the constriction is the higher the delivery performance. Contrary to this view, we demonstrate here a unique constriction profile that is highly localized (point) and yet returns comparably effective delivery. Point constrictions are of a semiround geometry, forcing cells in both dimensions while introducing very little backpressure to the system, which is a silicon-glass platform wherein constrictions are arranged in series along an array of channels. The influence of the constriction size and count as well as treatment pressure on delivery performance is presented on the basis of the flow-cytometric analyses of HCT116 cells treated using dextran as model molecules. Delivery performance is also presented for common mammalian cell lines including NIH 3T3, HEK293, and MDCK. Moreover, the versatility of the platform is demonstrated in gene knockdown experiments using synthetic siRNA as well as on the delivery of proteins. Target proteins in some cells exhibit nondiffusive distribution profile raising the plausibility of mechanisms other than transient membrane pores.
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Affiliation(s)
- Xiaoxing Xing
- College of Information Science and Technology, Beijing University of Chemical Technology , Beijing 100029, China
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9
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A conserved mammalian mitochondrial isoform of acetyl-CoA carboxylase ACC1 provides the malonyl-CoA essential for mitochondrial biogenesis in tandem with ACSF3. Biochem J 2017; 474:3783-3797. [PMID: 28986507 DOI: 10.1042/bcj20170416] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 09/29/2017] [Accepted: 10/03/2017] [Indexed: 01/06/2023]
Abstract
Mitochondrial fatty acid synthesis (mtFAS) is a highly conserved pathway essential for mitochondrial biogenesis. The mtFAS process is required for mitochondrial respiratory chain assembly and function, synthesis of the lipoic acid cofactor indispensable for the function of several mitochondrial enzyme complexes and essential for embryonic development in mice. Mutations in human mtFAS have been reported to lead to neurodegenerative disease. The source of malonyl-CoA for mtFAS in mammals has remained unclear. We report the identification of a conserved vertebrate mitochondrial isoform of ACC1 expressed from an ACACA transcript splicing variant. A specific knockdown (KD) of the corresponding transcript in mouse cells, or CRISPR/Cas9-mediated inactivation of the putative mitochondrial targeting sequence in human cells, leads to decreased lipoylation and mitochondrial fragmentation. Simultaneous KD of ACSF3, encoding a mitochondrial malonyl-CoA synthetase previously implicated in the mtFAS process, resulted in almost complete ablation of protein lipoylation, indicating that these enzymes have a redundant function in mtFAS. The discovery of a mitochondrial isoform of ACC1 required for lipoic acid synthesis has intriguing consequences for our understanding of mitochondrial disorders, metabolic regulation of mitochondrial biogenesis and cancer.
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10
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Liu N, Bechinger B, Süss R. The histidine-rich peptide LAH4-L1 strongly promotes PAMAM-mediated transfection at low nitrogen to phosphorus ratios in the presence of serum. Sci Rep 2017; 7:9585. [PMID: 28852016 PMCID: PMC5575053 DOI: 10.1038/s41598-017-10049-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 08/02/2017] [Indexed: 11/09/2022] Open
Abstract
Non-viral vectors are widely used and investigated for the delivery of genetic material into cells. However, gene delivery barriers like lysosomal degradation, serum inhibition and transient gene expression so far still limit their clinical applications. Aiming to overcome these limitations, a pH-sensitive hybrid gene vector (PSL complex) was designed by self-assembly of poly(amidoamine) (PAMAM) dendrimers, the histidine-rich peptide LAH4-L1 and the sleeping beauty transposon system (SB transposon system, a plasmid system capable of efficient and precise genomic insertion). Transfection studies revealed that PSL complexes achieved excellent efficiency in all investigated cell lines (higher than 90% in HeLa cells and over 30% in MDCK cells, a difficult-to-transfect cell line). Additionally, the PSL complexes showed high serum tolerance and exhibited outstanding transfection efficiency even in medium containing 50% serum (higher than 90% in HeLa cells). Moreover, a high level of long-term gene expression (over 30% in HeLa cells) was observed. Furthermore, PSL complexes not only resulted in high endocytosis, but also showed enhanced ability of endosomal escape compared to PAMAM/DNA complexes. These results demonstrate that simple association of PAMAM dendrimers, LAH4-L1 peptides and the SB transposon system by self-assembly is a general and promising strategy for efficient and safe gene delivery.
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Affiliation(s)
- Nan Liu
- Institute of Pharmaceutical Sciences, Department of Pharmaceutical Technology and Biopharmacy and Freiburger Materialforschungszentrum (FMF), Albert Ludwig University Freiburg, Sonnenstr. 5, 79104, Freiburg, Germany.
| | - Burkhard Bechinger
- University of Strasbourg/CNRS, Membrane Biophysics and NMR, Chemistry Institute UMR7177, rue Blaise Pascal 1, 67008, Strasbourg, France
| | - Regine Süss
- Institute of Pharmaceutical Sciences, Department of Pharmaceutical Technology and Biopharmacy and Freiburger Materialforschungszentrum (FMF), Albert Ludwig University Freiburg, Sonnenstr. 5, 79104, Freiburg, Germany.
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11
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Zhang K, Myllymäki SM, Gao P, Devarajan R, Kytölä V, Nykter M, Wei GH, Manninen A. Oncogenic K-Ras upregulates ITGA6 expression via FOSL1 to induce anoikis resistance and synergizes with αV-Class integrins to promote EMT. Oncogene 2017; 36:5681-5694. [PMID: 28604746 PMCID: PMC5658677 DOI: 10.1038/onc.2017.177] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 04/11/2017] [Accepted: 05/04/2017] [Indexed: 12/17/2022]
Abstract
In many cancer types, integrin-mediated signaling regulates proliferation, survival and invasion of tumorigenic cells. However, it is still unclear how integrins crosstalk with oncogenes to regulate tumorigenesis and metastasis. Here we show that oncogenic K-RasV12 upregulates α6-integrin expression in Madin–Darby canine kidney (MDCK) cells via activation of the mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK)/Fos-related antigen 1-signaling cascade. Activated α6-integrins promoted metastatic capacity and anoikis resistance, and led to perturbed growth of MDCK cysts. Transcriptomic analysis of K-RasV12-transformed MDCK cells also revealed robust downregulation of αV-class integrins. Re-expression of αV-integrin in K-RasV12-transformed MDCK cells synergistically upregulated the expression of Zinc finger E-box-binding homeobox 1 and Twist-related protein 1 and triggered epithelial-mesenchymal transition leading to induced cell motility and invasion. These results delineate the signaling cascades connecting oncogenic K-RasV12 with α6- and αV-integrin functions to modulate cancer cell survival and tumorigenesis, and reveal new possible strategies to target highly oncogenic K-RasV12 mutants.
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Affiliation(s)
- K Zhang
- Biocenter Oulu, Centre of Excellence in Cell-Extracellular Matrix Research, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - S-M Myllymäki
- Biocenter Oulu, Centre of Excellence in Cell-Extracellular Matrix Research, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - P Gao
- Biocenter Oulu, Centre of Excellence in Cell-Extracellular Matrix Research, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - R Devarajan
- Biocenter Oulu, Centre of Excellence in Cell-Extracellular Matrix Research, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - V Kytölä
- Prostate Cancer Research Center, Institute of Biomedical Technology and BioMediTech, University of Tampere and Tampere University Hospital, Tampere, Finland
| | - M Nykter
- Prostate Cancer Research Center, Institute of Biomedical Technology and BioMediTech, University of Tampere and Tampere University Hospital, Tampere, Finland
| | - G-H Wei
- Biocenter Oulu, Centre of Excellence in Cell-Extracellular Matrix Research, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - A Manninen
- Biocenter Oulu, Centre of Excellence in Cell-Extracellular Matrix Research, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
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12
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Moilanen JM, Löffek S, Kokkonen N, Salo S, Väyrynen JP, Hurskainen T, Manninen A, Riihilä P, Heljasvaara R, Franzke CW, Kähäri VM, Salo T, Mäkinen MJ, Tasanen K. Significant Role of Collagen XVII And Integrin β4 in Migration and Invasion of The Less Aggressive Squamous Cell Carcinoma Cells. Sci Rep 2017; 7:45057. [PMID: 28327550 PMCID: PMC5361192 DOI: 10.1038/srep45057] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 02/20/2017] [Indexed: 02/07/2023] Open
Abstract
Collagen XVII and integrin α6β4 have well-established roles as epithelial adhesion molecules. Their binding partner laminin 332 as well as integrin α6β4 are largely recognized to promote invasion and metastasis in various cancers, and collagen XVII is essential for the survival of colon and lung cancer stem cells. We have studied the expression of laminin γ2, collagen XVII and integrin β4 in tissue microarray samples of squamous cell carcinoma (SCC) and its precursors, actinic keratosis and Bowen's disease. The expression of laminin γ2 was highest in SCC samples, whereas the expression of collagen XVII and integrin β4 varied greatly in SCC and its precursors. Collagen XVII and integrin β4 were also expressed in SCC cell lines. Virus-mediated RNAi knockdown of collagen XVII and integrin β4 reduced the migration of less aggressive SCC-25 cells in horizontal scratch wound healing assay. Additionally, in a 3D organotypic myoma invasion assay the loss of collagen XVII or integrin β4 suppressed equally the migration and invasion of SCC-25 cells whereas there was no effect on the most aggressive HSC-3 cells. Variable expression patterns and results in migration and invasion assays suggest that collagen XVII and integrin β4 contribute to SCC tumorigenesis.
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Affiliation(s)
- Jyri M. Moilanen
- Department of Dermatology, PEDEGO Research Unit, Oulu Center for Cell-Matrix Research, MRC Oulu, University of Oulu and Oulu University Hospital, Finland
| | - Stefanie Löffek
- Skin Cancer Unit of the Dermatology Department, Medical Faculty, West German Cancer Center, University of Duisburg-Essen, Germany
| | - Nina Kokkonen
- Department of Dermatology, PEDEGO Research Unit, Oulu Center for Cell-Matrix Research, MRC Oulu, University of Oulu and Oulu University Hospital, Finland
| | - Sirpa Salo
- Oulu Center for Cell-Matrix Research, Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Juha P. Väyrynen
- Department of Pathology, Research Unit of Cancer and Translational Medicine, MRC Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland
| | - Tiina Hurskainen
- Department of Dermatology, PEDEGO Research Unit, Oulu Center for Cell-Matrix Research, MRC Oulu, University of Oulu and Oulu University Hospital, Finland
| | - Aki Manninen
- Oulu Center for Cell-Matrix Research, Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Pilvi Riihilä
- Department of Dermatology, Turku University Hospital, MediCity Research Laboratory, University of Turki, Turku, Finland
| | - Ritva Heljasvaara
- Oulu Center for Cell-Matrix Research, Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Claus-Werner Franzke
- Department of Dermatology, Medical Center, University of Freiburg, Freiburg, Germany
| | - Veli-Matti Kähäri
- Department of Dermatology, Turku University Hospital, MediCity Research Laboratory, University of Turki, Turku, Finland
| | - Tuula Salo
- Research Unit of Cancer and Translational Medicine, MRC Oulu, University of Oulu and Oulu University Hospital, Finland
- Department of Oral and Maxillo-facial Diseases, University of Helsinki, Finland
- HUSLAB, Department of Pathology, Helsinki University Central Hospital, Finland
- Department of Oral Diagnosis, Oral Pathology Division, Piracicaba Dental School, University of Campinas, Piracicaba, São Paulo, SP-13414-903, Brazil
| | - Markus J. Mäkinen
- Department of Pathology, Research Unit of Cancer and Translational Medicine, MRC Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland
| | - Kaisa Tasanen
- Department of Dermatology, PEDEGO Research Unit, Oulu Center for Cell-Matrix Research, MRC Oulu, University of Oulu and Oulu University Hospital, Finland
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13
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Jafari A, Qanie D, Andersen TL, Zhang Y, Chen L, Postert B, Parsons S, Ditzel N, Khosla S, Johansen HT, Kjærsgaard-Andersen P, Delaisse JM, Abdallah BM, Hesselson D, Solberg R, Kassem M. Legumain Regulates Differentiation Fate of Human Bone Marrow Stromal Cells and Is Altered in Postmenopausal Osteoporosis. Stem Cell Reports 2017; 8:373-386. [PMID: 28162997 PMCID: PMC5312427 DOI: 10.1016/j.stemcr.2017.01.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 01/03/2017] [Accepted: 01/04/2017] [Indexed: 12/21/2022] Open
Abstract
Secreted factors are a key component of stem cell niche and their dysregulation compromises stem cell function. Legumain is a secreted cysteine protease involved in diverse biological processes. Here, we demonstrate that legumain regulates lineage commitment of human bone marrow stromal cells and that its expression level and cellular localization are altered in postmenopausal osteoporotic patients. As shown by genetic and pharmacological manipulation, legumain inhibited osteoblast (OB) differentiation and in vivo bone formation through degradation of the bone matrix protein fibronectin. In addition, genetic ablation or pharmacological inhibition of legumain activity led to precocious OB differentiation and increased vertebral mineralization in zebrafish. Finally, we show that localized increased expression of legumain in bone marrow adipocytes was inversely correlated with adjacent trabecular bone mass in a cohort of patients with postmenopausal osteoporosis. Our data suggest that altered proteolytic activity of legumain in the bone microenvironment contributes to decreased bone mass in postmenopausal osteoporosis. Legumain determines differentiation fate of BMSCs in vitro and in vivo Legumain regulates BMSC proliferation independent of its enzymatic activity Inhibition of legumain leads to precocious bone formation in zebrafish Legumain is overexpressed in bone marrow adipocytes of osteoporotic patients
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Affiliation(s)
- Abbas Jafari
- Department of Cellular and Molecular Medicine, Danish Stem Cell Center (DanStem), University of Copenhagen, 2200 Copenhagen, Denmark; Molecular Endocrinology & Stem Cell Research Unit (KMEB), Department of Endocrinology and Metabolism, Odense University Hospital & University of Southern Denmark, J.B. Winsloewsvej 25, 1st Floor, 5000 Odense C, Denmark
| | - Diyako Qanie
- Molecular Endocrinology & Stem Cell Research Unit (KMEB), Department of Endocrinology and Metabolism, Odense University Hospital & University of Southern Denmark, J.B. Winsloewsvej 25, 1st Floor, 5000 Odense C, Denmark
| | - Thomas L Andersen
- Department of Clinical Cell Biology, Vejle/ Lillebaelt Hospital, Institute of Regional Health Research, University of Southern Denmark, 7100, Vejle, Denmark
| | - Yuxi Zhang
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, NSW 2010, Australia
| | - Li Chen
- Molecular Endocrinology & Stem Cell Research Unit (KMEB), Department of Endocrinology and Metabolism, Odense University Hospital & University of Southern Denmark, J.B. Winsloewsvej 25, 1st Floor, 5000 Odense C, Denmark
| | - Benno Postert
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, NSW 2010, Australia
| | - Stuart Parsons
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, NSW 2010, Australia
| | - Nicholas Ditzel
- Molecular Endocrinology & Stem Cell Research Unit (KMEB), Department of Endocrinology and Metabolism, Odense University Hospital & University of Southern Denmark, J.B. Winsloewsvej 25, 1st Floor, 5000 Odense C, Denmark
| | - Sundeep Khosla
- Endocrine Research Unit, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | | | | | - Jean-Marie Delaisse
- Department of Clinical Cell Biology, Vejle/ Lillebaelt Hospital, Institute of Regional Health Research, University of Southern Denmark, 7100, Vejle, Denmark
| | - Basem M Abdallah
- Molecular Endocrinology & Stem Cell Research Unit (KMEB), Department of Endocrinology and Metabolism, Odense University Hospital & University of Southern Denmark, J.B. Winsloewsvej 25, 1st Floor, 5000 Odense C, Denmark; Department of Biological Sciences, College of Science, King Faisal University, Hofuf 6996, Saudi Arabia
| | - Daniel Hesselson
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, NSW 2010, Australia; St Vincent's Clinical School, UNSW Australia, Sydney, NSW 2010, Australia
| | - Rigmor Solberg
- Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, 0363 Oslo, Norway
| | - Moustapha Kassem
- Department of Cellular and Molecular Medicine, Danish Stem Cell Center (DanStem), University of Copenhagen, 2200 Copenhagen, Denmark; Molecular Endocrinology & Stem Cell Research Unit (KMEB), Department of Endocrinology and Metabolism, Odense University Hospital & University of Southern Denmark, J.B. Winsloewsvej 25, 1st Floor, 5000 Odense C, Denmark; Stem Cell Unit, Department of Anatomy, Faculty of Medicine, King Saud University, Riyadh 12372, Saudi Arabia.
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14
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Salomon JJ, Spahn S, Wang X, Füllekrug J, Bertrand CA, Mall MA. Generation and functional characterization of epithelial cells with stable expression of SLC26A9 Cl- channels. Am J Physiol Lung Cell Mol Physiol 2016; 310:L593-602. [PMID: 26801567 DOI: 10.1152/ajplung.00321.2015] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 01/16/2016] [Indexed: 01/01/2023] Open
Abstract
Recent studies identified the SLC26A9 Cl(-) channel as a modifier and potential therapeutic target in cystic fibrosis (CF). However, understanding of the regulation of SLC26A9 in epithelia remains limited and cellular models with stable expression for biochemical and functional studies are missing. We, therefore, generated Fisher rat thyroid (FRT) epithelial cells with stable expression of HA-tagged SLC26A9 via retroviral transfection and characterized SLC26A9 expression and function using Western blotting, immunolocalization, whole cell patch-clamp, and transepithelial bioelectric studies in Ussing chambers. We demonstrate stable expression of SLC26A9 in transfected FRT (SLC26A9-FRT) cells on the mRNA and protein level. Immunolocalization and Western blotting detected SLC26A9 in different intracellular compartments and to a lesser extent at the cell surface. Whole cell patch-clamp recordings demonstrated significantly increased constitutive Cl(-) currents in SLC26A9-FRT compared with control-transduced FRT (Control-FRT) cells (P < 0.01). Similar, transepithelial measurements showed that the basal short circuit current was significantly increased in SLC26A9-FRT vs. Control-FRT cell monolayers (P < 0.01). SLC26A9-mediated Cl(-) currents were increased by cAMP-dependent stimulation (IBMX and forskolin) and inhibited by GlyH-101, niflumic acid, DIDS, and 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB), as well as RNAi knockdown of WNK1 implicated in epithelial osmoregulation. Our results support that these novel epithelial cells with stable expression of SLC26A9 will be a useful model for studies of pharmacological regulation including the identification of activators of SLC26A9 Cl(-) channels that may compensate deficient cystic fibrosis transmembrane regulator (CFTR)-mediated Cl(-) secretion and serve as an alternative therapeutic target in patients with CF and potentially other muco-obstructive lung diseases.
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Affiliation(s)
- Johanna J Salomon
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), Member of the German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany
| | - Stephan Spahn
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), Member of the German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany
| | - Xiaohui Wang
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; and
| | - Joachim Füllekrug
- Molecular Cell Biology Laboratory, Department of Internal Medicine IV, University of Heidelberg, Heidelberg, Germany
| | - Carol A Bertrand
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; and
| | - Marcus A Mall
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), Member of the German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany;
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15
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Frisdal E, Le Lay S, Hooton H, Poupel L, Olivier M, Alili R, Plengpanich W, Villard EF, Gilibert S, Lhomme M, Superville A, Miftah-Alkhair L, Chapman MJ, Dallinga-Thie GM, Venteclef N, Poitou C, Tordjman J, Lesnik P, Kontush A, Huby T, Dugail I, Clement K, Guerin M, Le Goff W. Adipocyte ATP-binding cassette G1 promotes triglyceride storage, fat mass growth, and human obesity. Diabetes 2015; 64:840-55. [PMID: 25249572 DOI: 10.2337/db14-0245] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The role of the ATP-binding cassette G1 (ABCG1) transporter in human pathophysiology is still largely unknown. Indeed, beyond its role in mediating free cholesterol efflux to HDL, the ABCG1 transporter equally promotes lipid accumulation in a triglyceride (TG)-rich environment through regulation of the bioavailability of lipoprotein lipase (LPL). Because both ABCG1 and LPL are expressed in adipose tissue, we hypothesized that ABCG1 is implicated in adipocyte TG storage and therefore could be a major actor in adipose tissue fat accumulation. Silencing of Abcg1 expression by RNA interference in 3T3-L1 preadipocytes compromised LPL-dependent TG accumulation during the initial phase of differentiation. Generation of stable Abcg1 knockdown 3T3-L1 adipocytes revealed that Abcg1 deficiency reduces TG storage and diminishes lipid droplet size through inhibition of Pparγ expression. Strikingly, local inhibition of adipocyte Abcg1 in adipose tissue from mice fed a high-fat diet led to a rapid decrease of adiposity and weight gain. Analysis of two frequent ABCG1 single nucleotide polymorphisms (rs1893590 [A/C] and rs1378577 [T/G]) in morbidly obese individuals indicated that elevated ABCG1 expression in adipose tissue was associated with increased PPARγ expression and adiposity concomitant to increased fat mass and BMI (haplotype AT>GC). The critical role of ABCG1 in obesity was further confirmed in independent populations of severe obese and diabetic obese individuals. This study identifies for the first time a major role of adipocyte ABCG1 in adiposity and fat mass growth and suggests that adipose ABCG1 might represent a potential therapeutic target in obesity.
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Affiliation(s)
- Eric Frisdal
- INSERM, UMR_S1166, Team 4, Paris, France Université Pierre et Marie Curie-Paris 6, Paris, France Institute of Cardiometabolism and Nutrition, Pitié-Salpêtrière Hospital, Paris, France
| | | | - Henri Hooton
- Université Pierre et Marie Curie-Paris 6, Paris, France INSERM, U872, Nutriomique Team 7, Cordeliers Research Center, Paris, France
| | - Lucie Poupel
- Institute of Cardiometabolism and Nutrition, Pitié-Salpêtrière Hospital, Paris, France
| | - Maryline Olivier
- INSERM, UMR_S1166, Team 4, Paris, France Université Pierre et Marie Curie-Paris 6, Paris, France
| | - Rohia Alili
- Université Pierre et Marie Curie-Paris 6, Paris, France Institute of Cardiometabolism and Nutrition, Pitié-Salpêtrière Hospital, Paris, France INSERM, U872, Nutriomique Team 7, Cordeliers Research Center, Paris, France
| | - Wanee Plengpanich
- INSERM, UMR_S1166, Team 4, Paris, France King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Patumwan, Bangkok, Thailand
| | - Elise F Villard
- INSERM, UMR_S1166, Team 4, Paris, France Université Pierre et Marie Curie-Paris 6, Paris, France Institute of Cardiometabolism and Nutrition, Pitié-Salpêtrière Hospital, Paris, France
| | - Sophie Gilibert
- INSERM, UMR_S1166, Team 4, Paris, France Université Pierre et Marie Curie-Paris 6, Paris, France Institute of Cardiometabolism and Nutrition, Pitié-Salpêtrière Hospital, Paris, France
| | - Marie Lhomme
- Institute of Cardiometabolism and Nutrition, Pitié-Salpêtrière Hospital, Paris, France
| | - Alexandre Superville
- INSERM, UMR_S1166, Team 4, Paris, France Université Pierre et Marie Curie-Paris 6, Paris, France Institute of Cardiometabolism and Nutrition, Pitié-Salpêtrière Hospital, Paris, France
| | | | - M John Chapman
- INSERM, UMR_S1166, Team 4, Paris, France Université Pierre et Marie Curie-Paris 6, Paris, France
| | | | - Nicolas Venteclef
- Université Pierre et Marie Curie-Paris 6, Paris, France Institute of Cardiometabolism and Nutrition, Pitié-Salpêtrière Hospital, Paris, France INSERM, U872, Nutriomique Team 7, Cordeliers Research Center, Paris, France
| | - Christine Poitou
- Université Pierre et Marie Curie-Paris 6, Paris, France Institute of Cardiometabolism and Nutrition, Pitié-Salpêtrière Hospital, Paris, France INSERM, U872, Nutriomique Team 7, Cordeliers Research Center, Paris, France Heart and Metabolism, Assistance-Publique Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Paris, France
| | - Joan Tordjman
- Université Pierre et Marie Curie-Paris 6, Paris, France Institute of Cardiometabolism and Nutrition, Pitié-Salpêtrière Hospital, Paris, France INSERM, U872, Nutriomique Team 7, Cordeliers Research Center, Paris, France
| | - Philippe Lesnik
- INSERM, UMR_S1166, Team 4, Paris, France Université Pierre et Marie Curie-Paris 6, Paris, France Institute of Cardiometabolism and Nutrition, Pitié-Salpêtrière Hospital, Paris, France
| | - Anatol Kontush
- INSERM, UMR_S1166, Team 4, Paris, France Université Pierre et Marie Curie-Paris 6, Paris, France Institute of Cardiometabolism and Nutrition, Pitié-Salpêtrière Hospital, Paris, France
| | - Thierry Huby
- INSERM, UMR_S1166, Team 4, Paris, France Université Pierre et Marie Curie-Paris 6, Paris, France Institute of Cardiometabolism and Nutrition, Pitié-Salpêtrière Hospital, Paris, France
| | - Isabelle Dugail
- Université Pierre et Marie Curie-Paris 6, Paris, France Institute of Cardiometabolism and Nutrition, Pitié-Salpêtrière Hospital, Paris, France INSERM, U872, Nutriomique Team 7, Cordeliers Research Center, Paris, France
| | - Karine Clement
- Université Pierre et Marie Curie-Paris 6, Paris, France Institute of Cardiometabolism and Nutrition, Pitié-Salpêtrière Hospital, Paris, France INSERM, U872, Nutriomique Team 7, Cordeliers Research Center, Paris, France Heart and Metabolism, Assistance-Publique Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Paris, France
| | - Maryse Guerin
- INSERM, UMR_S1166, Team 4, Paris, France Université Pierre et Marie Curie-Paris 6, Paris, France Institute of Cardiometabolism and Nutrition, Pitié-Salpêtrière Hospital, Paris, France
| | - Wilfried Le Goff
- INSERM, UMR_S1166, Team 4, Paris, France Université Pierre et Marie Curie-Paris 6, Paris, France Institute of Cardiometabolism and Nutrition, Pitié-Salpêtrière Hospital, Paris, France
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16
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Liang W, Chow MYT, Lau PN, Zhou QT, Kwok PCL, Leung GPH, Mason AJ, Chan HK, Poon LLM, Lam JKW. Inhalable dry powder formulations of siRNA and pH-responsive peptides with antiviral activity against H1N1 influenza virus. Mol Pharm 2015; 12:910-21. [PMID: 25599953 DOI: 10.1021/mp500745v] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Pulmonary delivery of siRNA has considerable therapeutic potential for treating viral respiratory infectious diseases including influenza. By introducing siRNA that targets the conserved region of viral genes encoding nucleocapsid protein (NP), viral mRNAs can be degraded and viral replication can be inhibited in mammalian cells. To enable siRNA to be used as an antiviral agent, the nucleic acid delivery barrier must be overcome. Effective local delivery of siRNA to lung tissues is required to reduce the therapeutic dose and minimize systemic adverse effects. To develop a formulation suited for clinical application, complexes of pH-responsive peptides, containing either histidine or 2,3-diaminopropionic acid (Dap), and siRNA were prepared into dry powders by spray drying with mannitol, which was used as a bulking agent. The spray-dried (SD) powders were characterized and found to be suitable for inhalation with good stability, preserving the integrity of the siRNA as well as the biological and antiviral activities. The formulations mediated highly effective in vitro delivery of antiviral siRNA into mammalian lung epithelial cells, leading to significant inhibition of viral replication when the transfected cells were subsequently challenged with H1N1 influenza virus. SD siRNA powders containing pH-responsive peptides are a promising inhalable formulation to deliver antiviral siRNA against influenza and are readily adapted for the treatment of other respiratory diseases.
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Affiliation(s)
- Wanling Liang
- Department of Pharmacology & Pharmacy, ‡School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong , 21 Sassoon Road, Pokfulam, Hong Kong
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17
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Junttila S, Saarela U, Halt K, Manninen A, Pärssinen H, Lecca MR, Brändli AW, Sims-Lucas S, Skovorodkin I, Vainio SJ. Functional genetic targeting of embryonic kidney progenitor cells ex vivo. J Am Soc Nephrol 2014; 26:1126-37. [PMID: 25201883 DOI: 10.1681/asn.2013060584] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Accepted: 07/23/2014] [Indexed: 01/11/2023] Open
Abstract
The embryonic mammalian metanephric mesenchyme (MM) is a unique tissue because it is competent to generate the nephrons in response to Wnt signaling. An ex vivo culture in which the MM is separated from the ureteric bud (UB), the natural inducer, can be used as a classic tubule induction model for studying nephrogenesis. However, technological restrictions currently prevent using this model to study the molecular genetic details before or during tubule induction. Using nephron segment-specific markers, we now show that tubule induction in the MM ex vivo also leads to the assembly of highly segmented nephrons. This induction capacity was reconstituted when MM tissue was dissociated into a cell suspension and then reaggregated (drMM) in the presence of human recombinant bone morphogenetic protein 7/human recombinant fibroblast growth factor 2 for 24 hours before induction. Growth factor-treated drMM also recovered the capacity for organogenesis when recombined with the UB. Cell tracking and time-lapse imaging of chimeric drMM cultures indicated that the nephron is not derived from a single progenitor cell. Furthermore, viral vector-mediated transduction of green fluorescent protein was much more efficient in dissociated MM cells than in intact mesenchyme, and the nephrogenic competence of transduced drMM progenitor cells was preserved. Moreover, drMM cells transduced with viral vectors mediating Lhx1 knockdown were excluded from the nephric tubules, whereas cells transduced with control vectors were incorporated. In summary, these techniques allow reproducible cellular and molecular examinations of the mechanisms behind nephrogenesis and kidney organogenesis in an ex vivo organ culture/organoid setting.
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Affiliation(s)
- Sanna Junttila
- Biocenter Oulu, Infotech Oulu, Center for Cell Matrix Research, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Ulla Saarela
- Biocenter Oulu, Infotech Oulu, Center for Cell Matrix Research, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Kimmo Halt
- Biocenter Oulu, Infotech Oulu, Center for Cell Matrix Research, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Aki Manninen
- Biocenter Oulu, Infotech Oulu, Center for Cell Matrix Research, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Heikki Pärssinen
- Biocenter Oulu, Infotech Oulu, Center for Cell Matrix Research, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - M Rita Lecca
- Functional Genomics Center Zurich, University of Zurich/ETH Zurich, Zurich, Switzerland
| | - André W Brändli
- Walter-Brendel-Centre of Experimental Medicine, Ludwig-Maximilians-University of Munich, Munich, Germany; and
| | - Sunder Sims-Lucas
- Rangos Research Center, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Ilya Skovorodkin
- Biocenter Oulu, Infotech Oulu, Center for Cell Matrix Research, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Seppo J Vainio
- Biocenter Oulu, Infotech Oulu, Center for Cell Matrix Research, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland;
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18
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Bohm K, Sun L, Thakor D, Wirth M. Caveolin-1 limits human influenza A virus (H1N1) propagation in mouse embryo-derived fibroblasts. Virology 2014; 462-463:241-53. [PMID: 24999049 DOI: 10.1016/j.virol.2014.05.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 01/16/2014] [Accepted: 05/23/2014] [Indexed: 02/07/2023]
Abstract
Caveolin expression supports the multiplication of retro-, ortho- and paramyxoviruses in susceptible cells. However, human influenza A virus (IAV), an orthomyxovirus, does not multiply efficiently in mouse embryo fibroblasts (MEFs), which are abundant in caveolin-1 (Cav-1). Surprisingly, the absence of Cav-1 in a MEF cell line removed the block for IAV replication and raised the infectious titer 250-fold, whereas the re-introduction of Cav-1 reversed the effect. The monitoring of cellular pathways revealed that Cav-1 loss considerably increased activities of p53. Furthermore, infection of MEF Cav-1 (-/-) induced reactive oxygen species (ROS) and pronounced apoptosis in the late phase of viral multiplication, but no type I IFN response. Strikingly, pharmacological inactivation showed that the elevated levels of ROS together with apoptosis caused the increase of virus yield. Thus, Cav-1 represents a new negative regulator of IAV infection in MEF that diminishes IAV infectious titer by controlling virus-supportive pathways.
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Affiliation(s)
- Katrin Bohm
- Department of Gene Regulation and Differentiation, Helmholtz Center for Infection Research, D-38124 Braunschweig, Germany.
| | - Lijing Sun
- Department of Gene Regulation and Differentiation, Helmholtz Center for Infection Research, D-38124 Braunschweig, Germany.
| | - Divyeshsinh Thakor
- Department of Gene Regulation and Differentiation, Helmholtz Center for Infection Research, D-38124 Braunschweig, Germany.
| | - Manfred Wirth
- Department of Gene Regulation and Differentiation, Helmholtz Center for Infection Research, D-38124 Braunschweig, Germany.
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19
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Protein mediated fatty acid uptake: Synergy between CD36/FAT-facilitated transport and acyl-CoA synthetase-driven metabolism. Arch Biochem Biophys 2014; 546:8-18. [DOI: 10.1016/j.abb.2014.01.025] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 01/17/2014] [Accepted: 01/23/2014] [Indexed: 11/21/2022]
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20
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Yao J, Li WY, Li SG, Feng XS, Gao SG. Recombinant lentivirus targeting the pleotrophin gene reduces pleotrophin protein expression in pancreatic cancer cells and inhibits neurite outgrowth of dorsal root ganglion neurons. Mol Med Rep 2014; 9:999-1004. [PMID: 24469464 DOI: 10.3892/mmr.2014.1918] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 01/10/2014] [Indexed: 11/06/2022] Open
Abstract
The objectives of the present study were to construct the recombinant primate lentivirus‑short hairpin RNA-pleiotrophin (pLV-shRNA-PTN) vector, to investigate the silencing effect of pLV-shRNA-PTN on PTN expression in MIA PaCa-2 cells and to observe the inhibition efficiency of pLV-shRNA‑PTN on neurite outgrowth from dorsal root ganglion (DRG) neurons in vitro. The construction procedure for recombinant lentivirus pLV-shRNA-PTN has been described previously. In the present study, pLV-shRNA‑PTN was used to infect MIA PaCa-2 pancreatic cancer cells and the efficiency of the knockdown of the PTN gene on day 7 following infection was analyzed using western blotting. The morphological changes in the cultured DRG neurons were observed by monoculture of DRG neurons and co-culture with MIA PaCa-2 cells in vitro. The recombinant lentivirus pLV-shRNA‑PTN was successfully constructed. The western blot analysis showed that the inhibition rates of PTN expression were 46, 80, 20 and 21%, respectively, following pLV-shRNA‑PTN-A, B, C and D infection. pLV-shRNA-PTN‑B showed the highest knockdown efficiency. DRG neurons co-cultured with infected MIA PaCa-2 cells were decreased in size when compared with the control, and there was a significant decrease in the number and length of neurites. The results suggest that efficient and specific knockdown of PTN in MIA PaCa-2 pancreatic cancer cells and the subsequent reduction in PTN expression results in the inhibition of neurite outgrowth from DRG neurons.
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Affiliation(s)
- Jun Yao
- Department of Oncology, First Affiliated Hospital, Henan University of Science and Technology, Luoyang, Henan 471003, P.R. China
| | - Wen-Yao Li
- Department of Oncology, First Affiliated Hospital, Henan University of Science and Technology, Luoyang, Henan 471003, P.R. China
| | - Shuo-Guo Li
- Department of Oncology, First Affiliated Hospital, Henan University of Science and Technology, Luoyang, Henan 471003, P.R. China
| | - Xiao-Shan Feng
- Department of Oncology, First Affiliated Hospital, Henan University of Science and Technology, Luoyang, Henan 471003, P.R. China
| | - She-Gan Gao
- Department of Oncology, First Affiliated Hospital, Henan University of Science and Technology, Luoyang, Henan 471003, P.R. China
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21
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Using replication defective viruses to analyze membrane trafficking in polarized epithelial cells. Methods Cell Biol 2013. [PMID: 24295304 DOI: 10.1016/b978-0-12-417164-0.00008-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Epithelial cells in culture, especially once they are polarized, are extremely hard to manipulate by transient transfection methods. The use of replication defective adenoviruses for gene expression or replication defective retroviruses or lentiviruses to express shRNA for gene knockdown provides efficient tools to manipulate gene expression patterns even in hard-to-transfect cell lines. One of the advantages of using defective adenoviruses for gene expression is that once the virus has been generated, it can easily be applied to a wide variety of cells. In addition, replication defective retro- and lentiviruses are used to stably deplete proteins from cell lines, which subsequently may be used for analyzing the polarized surface delivery of receptors that may be expressed using defective adenoviruses. The latter approach is especially useful if the expressed shRNA also encodes GFP for easy assessment of shRNA-expressing cells. Thus the use of defective viruses in epithelial cell research is convenient. This makes a detailed infection protocol a research tool that would be valuable to many laboratories. Here we describe in detail how cells are infected with defective retro- or lentiviruses and subsequently selected for stable gene knockdown. We then describe how these cells may be used for infection with defective adenoviruses and the subsequent analyses.
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αV-integrins are required for mechanotransduction in MDCK epithelial cells. PLoS One 2013; 8:e71485. [PMID: 23977051 PMCID: PMC3747215 DOI: 10.1371/journal.pone.0071485] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Accepted: 06/29/2013] [Indexed: 01/12/2023] Open
Abstract
The properties of epithelial cells within tissues are regulated by their immediate microenvironment, which consists of neighboring cells and the extracellular matrix (ECM). Integrin heterodimers orchestrate dynamic assembly and disassembly of cell-ECM connections and thereby convey biochemical and mechanical information from the ECM into cells. However, the specific contributions and functional hierarchy between different integrin heterodimers in the regulation of focal adhesion dynamics in epithelial cells are incompletely understood. Here, we have studied the functions of RGD-binding αV-integrins in a Madin Darby Canine Kidney (MDCK) cell model and found that αV-integrins regulate the maturation of focal adhesions (FAs) and cell spreading. αV-integrin-deficient MDCK cells bound collagen I (Col I) substrate via α2β1-integrins but failed to efficiently recruit FA components such as talin, focal adhesion kinase (FAK), vinculin and integrin-linked kinase (ILK). The apparent inability to mature α2β1-integrin-mediated FAs and link them to cellular actin cytoskeleton led to disrupted mechanotransduction in αV-integrin deficient cells seeded onto Col I substrate.
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Pabis M, Neufeld N, Steiner MC, Bojic T, Shav-Tal Y, Neugebauer KM. The nuclear cap-binding complex interacts with the U4/U6·U5 tri-snRNP and promotes spliceosome assembly in mammalian cells. RNA (NEW YORK, N.Y.) 2013; 19:1054-63. [PMID: 23793891 PMCID: PMC3708526 DOI: 10.1261/rna.037069.112] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2012] [Accepted: 04/24/2013] [Indexed: 05/23/2023]
Abstract
The nuclear cap-binding complex (CBC) binds to the 7-methyl guanosine cap present on every RNA polymerase II transcript. CBC has been implicated in many aspects of RNA biogenesis; in addition to roles in miRNA biogenesis, nonsense-mediated decay, 3'-end formation, and snRNA export from the nucleus, CBC promotes pre-mRNA splicing. An unresolved question is how CBC participates in splicing. To investigate CBC's role in splicing, we used mass spectrometry to identify proteins that copurify with mammalian CBC. Numerous components of spliceosomal snRNPs were specifically detected. Among these, three U4/U6·U5 snRNP proteins (hBrr2, hPrp4, and hPrp31) copurified with CBC in an RNA-independent fashion, suggesting that a significant fraction of CBC forms a complex with the U4/U6·U5 snRNP and that the activity of CBC might be associated with snRNP recruitment to pre-mRNA. To test this possibility, CBC was depleted from HeLa cells by RNAi. Chromatin immunoprecipitation and live-cell imaging assays revealed decreased cotranscriptional accumulation of U4/U6·U5 snRNPs on active transcription units, consistent with a requirement for CBC in cotranscriptional spliceosome assembly. Surprisingly, recruitment of U1 and U2 snRNPs was also affected, indicating that RNA-mediated interactions between CBC and snRNPs contribute to splicing. On the other hand, CBC depletion did not impair snRNP biogenesis, ruling out the possibility that decreased snRNP recruitment was due to changes in nuclear snRNP concentration. Taken together, the data support a model whereby CBC promotes pre-mRNA splicing through a network of interactions with and among spliceosomal snRNPs during cotranscriptional spliceosome assembly.
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Affiliation(s)
- Marta Pabis
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Noa Neufeld
- The Mina & Everard Goodman Faculty of Life Sciences, Institute of Nanotechnology, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Michaela C. Steiner
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Teodora Bojic
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Yaron Shav-Tal
- The Mina & Everard Goodman Faculty of Life Sciences, Institute of Nanotechnology, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Karla M. Neugebauer
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
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Chen JW, Zhang Y, Zhang YL, Wei C, Liu X, Zhou NR, Jia Q, Li YS, Zhang XR, Zhang YH. Construction of multiple shRNAs expression vector that inhibits FUT1 gene expression and production of the transgenic SCNT embryos in vitro. Mol Biol Rep 2013; 40:2243-52. [PMID: 23203408 DOI: 10.1007/s11033-012-2287-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Accepted: 11/19/2012] [Indexed: 10/27/2022]
Abstract
Enterotoxigenic Escherichia coli F18 is a major pathogen that causes postweaning diarrhoea and edema disease in piglets. The alpha(1,2)-fucosyltransferase (FUT1) gene has been identified as an ideal candidate gene for controlling the expression of the receptor for ECF18 bacteria. Therefore, the use of RNA interference (RNAi) to study the function of the FUT1 gene and to produce FUT1 knockdown transgenic pig would be highly beneficial. We developed an effective strategy for the expression of multiple small hairpin RNA simultaneously using multiple RNA polymerase III (hU6, hH1, mU6 and h7SK) promoters in a single vector to knockdown the FUT1 gene. Stable FUT1 knockdown transgenic fibroblast lines were generated by transfecting porcine fetal fibroblasts with the constructed vectors. Real-time RT-PCR indicated that the mRNA level of FUT1 in the transgenic fibroblast lines was significantly lower than that in the control, as much as 29 %. Finally, we successfully obtained transgenic SCNT porcine embryos. Overall, the results demonstrated that this vector-based RNAi expression system is an efficient approach to knockdown FUT1 gene expression in porcine fetal fibroblast cells, which could thereby provide donor cells for somatic cell nuclear cloning and the potential production of a marker-free transgenic pig resistant to F18 related diseases. Furthermore, it also provides strong evidence that this approach could be useful both in the production of transgenic livestock resistant to disease, and in the development of effective strategies for the suppression of gene expression in clinical gene therapy.
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Affiliation(s)
- Jian-wen Chen
- Anhui Provincial Laboratory of Local Livestock and Poultry Genetical Resource Conservation and Breeding, College of Animal Science and Technology, Anhui Agricultural University, No.130 of Changjiang West Road, Hefei, 230036, Anhui, China
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25
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Arnold A, Naaldijk YM, Fabian C, Wirth H, Binder H, Nikkhah G, Armstrong L, Stolzing A. Reprogramming of Human Huntington Fibroblasts Using mRNA. ACTA ACUST UNITED AC 2012. [DOI: 10.5402/2012/124878] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The derivation of
induced pluripotent stem cells (iPS) from human
cell sources using transduction based on viral
vectors has been reported by several
laboratories. Viral vector-induced integration
is a potential cause of genetic modification. We
have derived iPS cells from human foreskin,
adult Huntington fibroblasts, and adult skin
fibroblasts of healthy donors using a nonviral
and nonintegrating procedure based on mRNA
transfer. In vitro transcribed mRNA for 5
factors, oct-4, nanog, klf-4, c-myc, sox-2 as
well as for one new factor, hTERT, was used to
induce pluripotency. Reprogramming was analyzed
by qPCR analysis of pluripotency gene
expression, differentiation, gene expression
array, and teratoma assays. iPS cells were shown
to express pluripotency markers and were able to
differentiate towards ecto-, endo-, and
mesodermal lineages. This method may represent a
safer technology for reprogramming and
derivation of iPS cells. Cells produced by this
method can more easily be transferred into the
clinical setting.
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Affiliation(s)
- Antje Arnold
- Fraunhofer Institute for Cell Therapy and Immunology, Perlickstraβe 1, 04103 Leipzig, Germany
| | - Yahaira M. Naaldijk
- Fraunhofer Institute for Cell Therapy and Immunology, Perlickstraβe 1, 04103 Leipzig, Germany
| | - Claire Fabian
- Institute of Virology, University of Leipzig, Johannisallee 30, 04103 Leipzig, Germany
| | - Henry Wirth
- Interdisciplinary Centre for Bioinformatics, University of Leipzig, Härtelstraβe 16-18, 04107 Leipzig, Germany
| | - Hans Binder
- Interdisciplinary Centre for Bioinformatics, University of Leipzig, Härtelstraβe 16-18, 04107 Leipzig, Germany
| | - Guido Nikkhah
- Department Stereotactic and Functional Neurosurgery, University Hospital of Freiburg, Breisacher Straβe 67, 79106 Freiburg, Germany
| | - Lyle Armstrong
- Institute of Human Genetics, Newcastle University, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
| | - Alexandra Stolzing
- Fraunhofer Institute for Cell Therapy and Immunology, Perlickstraβe 1, 04103 Leipzig, Germany
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Valque H, Gouyer V, Gottrand F, Desseyn JL. MUC5B leads to aggressive behavior of breast cancer MCF7 cells. PLoS One 2012; 7:e46699. [PMID: 23056409 PMCID: PMC3462796 DOI: 10.1371/journal.pone.0046699] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Accepted: 09/06/2012] [Indexed: 11/18/2022] Open
Abstract
The mucin MUC5B has a critical protective function in the normal lung, salivary glands, esophagus, and gallbladder, and has been reported to be aberrantly expressed in breast cancer, the second leading cause of cancer-related deaths among women worldwide. To understand better the implication of MUC5B in cancer pathogenesis, the luminal human breast cancer cell line MCF7 was transfected with a vector encoding a recombinant mini-mucin MUC5B and was then infected with a virus to deliver a short hairpin RNA to knock down the mini-mucin. The proliferative and invasive properties in Matrigel of MCF7 subclones and subpopulations were evaluated in vitro. A xenograft model was established by subcutaneous inoculation of MCF7 clones and subpopulations in SCID mice. Tumor growth was measured, and the tumors and metastases were assessed by histological and immunological analysis. The mini-mucin MUC5B promoted MCF7 cell proliferation and invasion in vitro. The xenograft experiments demonstrated that the mini-mucin promoted tumor growth and MCF7 cell dissemination. In conclusion, MUC5B expression is associated with aggressive behavior of MCF7 breast cancer cells. This study suggests that MUC5B may represent a good target for slowing tumor growth and metastasis.
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Affiliation(s)
- Hélène Valque
- Inserm U995, Lille, France
- University Lille 2, Lille, France
| | - Valérie Gouyer
- Inserm U995, Lille, France
- University Lille 2, Lille, France
- CHRU of Lille, Lille, France
| | - Frédéric Gottrand
- Inserm U995, Lille, France
- University Lille 2, Lille, France
- CHRU of Lille, Lille, France
| | - Jean-Luc Desseyn
- Inserm U995, Lille, France
- University Lille 2, Lille, France
- * E-mail:
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27
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Zhan T, Poppelreuther M, Ehehalt R, Füllekrug J. Overexpressed FATP1, ACSVL4/FATP4 and ACSL1 increase the cellular fatty acid uptake of 3T3-L1 adipocytes but are localized on intracellular membranes. PLoS One 2012; 7:e45087. [PMID: 23024797 PMCID: PMC3443241 DOI: 10.1371/journal.pone.0045087] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Accepted: 08/17/2012] [Indexed: 01/23/2023] Open
Abstract
Long chain acyl-CoA synthetases are essential enzymes of lipid metabolism, and have also been implicated in the cellular uptake of fatty acids. It is controversial if some or all of these enzymes have an additional function as fatty acid transporters at the plasma membrane. The most abundant acyl-CoA synthetases in adipocytes are FATP1, ACSVL4/FATP4 and ACSL1. Previous studies have suggested that they increase fatty acid uptake by direct transport across the plasma membrane. Here, we used a gain-of-function approach and established FATP1, ACSVL4/FATP4 and ACSL1 stably expressing 3T3-L1 adipocytes by retroviral transduction. All overexpressing cell lines showed increased acyl-CoA synthetase activity and fatty acid uptake. FATP1 and ACSVL4/FATP4 localized to the endoplasmic reticulum by confocal microscopy and subcellular fractionation whereas ACSL1 was found on mitochondria. Insulin increased fatty acid uptake but without changing the localization of FATP1 or ACSVL4/FATP4. We conclude that overexpressed acyl-CoA synthetases are able to facilitate fatty acid uptake in 3T3-L1 adipocytes. The intracellular localization of FATP1, ACSVL4/FATP4 and ACSL1 indicates that this is an indirect effect. We suggest that metabolic trapping is the mechanism behind the influence of acyl-CoA synthetases on cellular fatty acid uptake.
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Affiliation(s)
- Tianzuo Zhan
- Molecular Cell Biology Laboratory, Internal Medicine IV, University of Heidelberg, Heidelberg, Germany
| | - Margarete Poppelreuther
- Molecular Cell Biology Laboratory, Internal Medicine IV, University of Heidelberg, Heidelberg, Germany
| | - Robert Ehehalt
- Molecular Cell Biology Laboratory, Internal Medicine IV, University of Heidelberg, Heidelberg, Germany
| | - Joachim Füllekrug
- Molecular Cell Biology Laboratory, Internal Medicine IV, University of Heidelberg, Heidelberg, Germany
- * E-mail:
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28
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Gálvez-Santisteban M, Rodriguez-Fraticelli AE, Bryant DM, Vergarajauregui S, Yasuda T, Bañón-Rodríguez I, Bernascone I, Datta A, Spivak N, Young K, Slim CL, Brakeman PR, Fukuda M, Mostov KE, Martín-Belmonte F. Synaptotagmin-like proteins control the formation of a single apical membrane domain in epithelial cells. Nat Cell Biol 2012; 14:838-49. [PMID: 22820376 PMCID: PMC3433678 DOI: 10.1038/ncb2541] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Accepted: 06/14/2012] [Indexed: 12/16/2022]
Abstract
The formation of epithelial tissues requires both the generation of apical-basal polarity and the coordination of this polarity between neighbouring cells to form a central lumen. During de novo lumen formation, vectorial membrane transport contributes to the formation of a singular apical membrane, resulting in the contribution of each cell to only a single lumen. Here, from a functional screen for genes required for three-dimensional epithelial architecture, we identify key roles for synaptotagmin-like proteins 2-a and 4-a (Slp2-a/4-a) in the generation of a single apical surface per cell. Slp2-a localizes to the luminal membrane in a PtdIns(4,5)P(2)-dependent manner, where it targets Rab27-loaded vesicles to initiate a single lumen. Vesicle tethering and fusion is controlled by Slp4-a, in conjunction with Rab27/Rab3/Rab8 and the SNARE syntaxin-3. Together, Slp2-a/4-a coordinate the spatiotemporal organization of vectorial apical transport to ensure that only a single apical surface, and thus the formation of a single lumen, occurs per cell.
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Affiliation(s)
- Manuel Gálvez-Santisteban
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, C/Nicolás Cabrera 1, Madrid 28049, Spain
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29
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Poppelreuther M, Rudolph B, Du C, Großmann R, Becker M, Thiele C, Ehehalt R, Füllekrug J. The N-terminal region of acyl-CoA synthetase 3 is essential for both the localization on lipid droplets and the function in fatty acid uptake. J Lipid Res 2012; 53:888-900. [PMID: 22357706 PMCID: PMC3329388 DOI: 10.1194/jlr.m024562] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Revised: 02/21/2012] [Indexed: 12/19/2022] Open
Abstract
Cytosolic lipid droplets (LDs) are storage organelles for neutral lipids derived from endogenous metabolism. Acyl-CoA synthetase family proteins are essential enzymes in this biosynthetic pathway, contributing activated fatty acids. Fluorescence microscopy showed that ACSL3 is localized to the endoplasmic reticulum (ER) and LDs, with the distribution dependent on the cell type and the supply of fatty acids. The N-terminus of ACSL3 was necessary and sufficient for targeting reporter proteins correctly, as demonstrated by subcellular fractionation and confocal microscopy. The N-terminal region of ACSL3 was also found to be functionally required for the enzyme activity. Selective permeabilization and in silico analysis suggest that ACSL3 assumes a hairpin membrane topology, with the N-terminal hydrophobic amino acids forming an amphipathic helix restricted to the cytosolic leaflet of the ER membrane. ACSL3 was effectively translocated from the ER to nascent LDs when neutral lipid synthesis was stimulated by the external addition of fatty acids. Cellular fatty acid uptake was increased by overexpression and reduced by RNA interference of ACSL3. In conclusion, the structural organization of ACSL3 allows the fast and efficient movement from the ER to emerging LDs. ACSL3 not only esterifies fatty acids with CoA but is also involved in the cellular uptake of fatty acids, presumably indirectly by metabolic trapping. The unique localization of the acyl-CoA synthetase ACSL3 on LDs suggests a function in the local synthesis of lipids.
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Affiliation(s)
- Margarete Poppelreuther
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany; and
| | - Berenice Rudolph
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany; and
| | - Chen Du
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany; and
| | - Regina Großmann
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany; and
| | - Melanie Becker
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany; and
| | | | - Robert Ehehalt
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany; and
| | - Joachim Füllekrug
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Germany; and.
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30
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Qi R, Liu S, Chen J, Xiao H, Yan L, Huang Y, Jing X. Biodegradable copolymers with identical cationic segments and their performance in siRNA delivery. J Control Release 2012; 159:251-60. [DOI: 10.1016/j.jconrel.2012.01.015] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Revised: 12/21/2011] [Accepted: 01/13/2012] [Indexed: 10/14/2022]
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Neuropeptide Y inhibits interleukin-1β-induced phagocytosis by microglial cells. J Neuroinflammation 2011; 8:169. [PMID: 22136135 PMCID: PMC3239417 DOI: 10.1186/1742-2094-8-169] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Accepted: 12/02/2011] [Indexed: 12/18/2022] Open
Abstract
Background Neuropeptide Y (NPY) is emerging as a modulator of communication between the brain and the immune system. However, in spite of increasing evidence that supports a role for NPY in the modulation of microglial cell responses to inflammatory conditions, there is no consistent information regarding the action of NPY on microglial phagocytic activity, a vital component of the inflammatory response in brain injury. Taking this into consideration, we sought to assess a potential new role for NPY as a modulator of phagocytosis by microglial cells. Methods The N9 murine microglial cell line was used to evaluate the role of NPY in phagocytosis. For that purpose, an IgG-opsonized latex bead assay was performed in the presence of lipopolysaccharide (LPS) and an interleukin-1β (IL-1β) challenge, and upon NPY treatment. A pharmacological approach using NPY receptor agonists and antagonists followed to uncover which NPY receptor was involved. Moreover, western blotting and immunocytochemical studies were performed to evaluate expression of p38 mitogen-activated protein kinase (MAPK) and heat shock protein 27 (HSP27), in an inflammatory context, upon NPY treatment. Results Here, we show that NPY inhibits phagocytosis of opsonized latex beads and inhibits actin cytoskeleton reorganization triggered by LPS stimulation. Co-stimulation of microglia with LPS and adenosine triphosphate also resulted in increased phagocytosis, an effect inhibited by an interleukin-1 receptor antagonist, suggesting involvement of IL-1β signaling. Furthermore, direct application of LPS or IL-1β activated downstream signaling molecules, including p38 MAPK and HSP27, and these effects were inhibited by NPY. Moreover, we also observed that the inhibitory effect of NPY on phagocytosis was mediated via Y1 receptor activation. Conclusions Altogether, we have identified a novel role for NPY in the regulation of microglial phagocytic properties, in an inflammatory context.
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Digel M, Staffer S, Ehehalt F, Stremmel W, Ehehalt R, Füllekrug J. FATP4 contributes as an enzyme to the basal and insulin-mediated fatty acid uptake of C₂C₁₂ muscle cells. Am J Physiol Endocrinol Metab 2011; 301:E785-96. [PMID: 21750264 DOI: 10.1152/ajpendo.00079.2011] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The function of membrane proteins in long-chain fatty acid transport is controversial. The acyl-CoA synthetase fatty acid transport protein-4 (FATP4) has been suggested to facilitate fatty acid uptake indirectly by its enzymatic activity, or directly by transport across the plasma membrane. Here, we investigated the function of FATP4 in basal and insulin mediated fatty acid uptake in C(2)C(12) muscle cells, a model system relevant for fatty acid metabolism. Stable expression of exogenous FATP4 resulted in a twofold higher fatty acyl-CoA synthetase activity, and cellular uptake of oleate was enhanced similarly. Kinetic analysis demonstrated that FATP4 allowed the cells to reach apparent saturation of fatty acid uptake at a twofold higher level compared with control. Short-term treatment with insulin increased fatty acid uptake in line with previous reports. Surprisingly, insulin increased the acyl-CoA synthetase activity of C(2)C(12) cells within minutes. This effect was sensitive to inhibition of insulin signaling by wortmannin. Affinity purified FATP4 prepared from insulin-treated cells showed an enhanced enzyme activity, suggesting it constitutes a novel target of short-term metabolic regulation by insulin. This offers a new mechanistic explanation for the concomitantly observed enhanced fatty acid uptake. FATP4 was colocalized to the endoplasmic reticulum by double immunofluorescence and subcellular fractionation, clearly distinct from the plasma membrane. Importantly, neither differentiation into myotubes nor insulin treatment changed the localization of FATP4. We conclude that FATP4 functions by its intrinsic enzymatic activity. This is in line with the concept that intracellular metabolism plays a significant role in cellular fatty acid uptake.
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Affiliation(s)
- Margarete Digel
- Molecular Cell Biology Laboratory Internal Medicine IV, University of Heidelberg, Heidelberg, Germany
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33
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Greciano PG, Moyano JV, Buschmann MM, Tang J, Lu Y, Rudnicki J, Manninen A, Matlin KS. Laminin 511 partners with laminin 332 to mediate directional migration of Madin-Darby canine kidney epithelial cells. Mol Biol Cell 2011; 23:121-36. [PMID: 22031290 PMCID: PMC3248892 DOI: 10.1091/mbc.e11-08-0718] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Sustained directional migration of epithelial cells is essential for regeneration of injured epithelia. Front-rear polarity of migrating cells is determined by local activation of a signaling network involving Cdc42 and other factors in response to spatial cues from the environment, the nature of which are obscure. We examined the roles of laminin (LM)-511 and LM-332, two structurally different laminin isoforms, in the migration of Madin-Darby canine kidney cells by suppressing expression of their α subunits using RNA interference. We determined that knockdown of LM-511 inhibits directional migration and destabilizes cell-cell contacts, in part by disturbing the localization and activity of the polarization machinery. Suppression of integrin α3, a laminin receptor subunit, in cells synthesizing normal amounts of both laminins has a similar effect as knockdown of LM-511. Surprisingly, simultaneous suppression of both laminin α5 and laminin α3 restores directional migration and cell-cell contact stability, suggesting that cells recognize a haptotactic gradient formed by a combination of laminins.
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Affiliation(s)
- Patricia G Greciano
- Department of Surgery and Committee on Molecular Medicine, University of Chicago, Chicago, IL 60637, USA.
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Ward HH, Brown-Glaberman U, Wang J, Morita Y, Alper SL, Bedrick EJ, Gattone VH, Deretic D, Wandinger-Ness A. A conserved signal and GTPase complex are required for the ciliary transport of polycystin-1. Mol Biol Cell 2011; 22:3289-305. [PMID: 21775626 PMCID: PMC3172256 DOI: 10.1091/mbc.e11-01-0082] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Primary cilia regulate epithelial differentiation and organ function. Failure of mutant polycystins to localize to cilia abolishes flow-stimulated calcium signaling and causes autosomal dominant polycystic kidney disease. We identify a conserved amino acid sequence, KVHPSST, in the C-terminus of polycystin-1 (PC1) that serves as a ciliary-targeting signal. PC1 binds a multimeric protein complex consisting of several GTPases (Arf4, Rab6, Rab11) and the GTPase-activating protein (GAP), ArfGAP with SH3 domain, ankyrin repeat and PH domain 1 (ASAP1) in the Golgi, which facilitates vesicle budding and Golgi exocytosis. A related N-terminal ciliary-targeting sequence in polycystin-2 similarly binds Arf4. Deletion of the extreme C-terminus of PC1 ablates Arf4 and ASAP1 binding and prevents ciliary localization of an integral membrane CD16.7-PC1 chimera. Interactions are confirmed for chimeric and endogenous proteins through quantitated in vitro and cell-based approaches. PC1 also complexes with Rab8; knockdown of trafficking regulators Arf4 or Rab8 functionally blocks CD16.7-PC1 trafficking to cilia. Mutations in rhodopsin disrupt a similar signal and cause retinitis pigmentosa, while Bardet-Biedl syndrome, primary open-angle glaucoma, and tumor cell invasiveness are linked to dysregulation of ASAP1 or Rab8 or its effectors. In this paper, we provide evidence for a conserved GTPase-dependent ciliary-trafficking mechanism that is shared between epithelia and neurons, and is essential in ciliary-trafficking and cell homeostasis.
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Affiliation(s)
- Heather H Ward
- Department of Pathology, Harvard Medical School, Boston, MA 02215, USA
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Myllymäki SM, Teräväinen TP, Manninen A. Two distinct integrin-mediated mechanisms contribute to apical lumen formation in epithelial cells. PLoS One 2011; 6:e19453. [PMID: 21573123 PMCID: PMC3089628 DOI: 10.1371/journal.pone.0019453] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2011] [Accepted: 03/29/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Formation of apical compartments underlies the morphogenesis of most epithelial organs during development. The extracellular matrix (ECM), particularly the basement membrane (BM), plays an important role in orienting the apico-basal polarity and thereby the positioning of apical lumens. Integrins have been recognized as essential mediators of matrix-derived polarity signals. The importance of β1-integrins in epithelial polarization is well established but the significance of the accompanying α-subunits have not been analyzed in detail. PRINCIPAL FINDINGS Here we demonstrate that two distinct integrin-dependent pathways regulate formation of apical lumens to ensure robust apical membrane biogenesis under different microenvironmental conditions; 1) α2β1- and α6β4-integrins were required to establish a basal cue that depends on Rac1-activity and guides apico-basal cell polarization. 2) α3β1-integrins were implicated in positioning of mitotic spindles in cysts, a process that is essential for Cdc42-driven epithelial hollowing. SIGNIFICANCE Identification of the separate processes driven by particular integrin receptors clarifies the functional hierarchies between the different integrins co-expressed in epithelial cells and provides valuable insight into the complexity of cell-ECM interactions thereby guiding future studies addressing the molecular basis of epithelial morphogenesis during development and disease.
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Affiliation(s)
- Satu Marja Myllymäki
- Biocenter Oulu, Oulu Center for Cell-Matrix Research, Department of Medical Biochemistry and Molecular Biology, University of Oulu, Oulu, Finland
| | - Terhi Piritta Teräväinen
- Biocenter Oulu, Oulu Center for Cell-Matrix Research, Department of Medical Biochemistry and Molecular Biology, University of Oulu, Oulu, Finland
| | - Aki Manninen
- Biocenter Oulu, Oulu Center for Cell-Matrix Research, Department of Medical Biochemistry and Molecular Biology, University of Oulu, Oulu, Finland
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Mcintyre GJ, Arndt AJ, Gillespie KM, Mak WM, Fanning GC. A comparison of multiple shRNA expression methods for combinatorial RNAi. GENETIC VACCINES AND THERAPY 2011; 9:9. [PMID: 21496330 PMCID: PMC3098768 DOI: 10.1186/1479-0556-9-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Accepted: 04/17/2011] [Indexed: 01/09/2023]
Abstract
RNAi gene therapies for HIV-1 will likely need to employ multiple shRNAs to counter resistant strains. We evaluated 3 shRNA co-expression methods to determine their suitability for present use; multiple expression vectors, multiple expression cassettes and single transcripts comprised of several dsRNA units (aka domains) with each being designed to a different target. Though the multiple vector strategy was effective with 2 shRNAs, the increasing number of vectors required is a major shortcoming. With single transcript configurations we only saw adequate activity from 1 of 10 variants tested, the variants being comprised of 2 - 3 different target domains. Whilst single transcript configurations have the most advantages on paper, these configurations can not yet be rapidly and reliably re-configured for new targets. However, our multiple cassette combinations of 2, 3 and 4 (29 bp) shRNAs were all successful, with suitable activity maintained in all positions and net activities comparable to that of the corresponding single shRNAs. We conclude that the multiple cassette strategy is the most suitably developed for present use as it is easy to design, assemble, is directly compatible with pre-existing shRNA and can be easily expanded.
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Affiliation(s)
- Glen J Mcintyre
- Johnson and Johnson Research Pty Ltd, Level 4 Biomedical Building, 1 Central Avenue, Australian Technology Park, Eveleigh, NSW, 1430, Australia
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Allison J Arndt
- Johnson and Johnson Research Pty Ltd, Level 4 Biomedical Building, 1 Central Avenue, Australian Technology Park, Eveleigh, NSW, 1430, Australia
| | - Kirsten M Gillespie
- Johnson and Johnson Research Pty Ltd, Level 4 Biomedical Building, 1 Central Avenue, Australian Technology Park, Eveleigh, NSW, 1430, Australia
| | - Wendy M Mak
- Johnson and Johnson Research Pty Ltd, Level 4 Biomedical Building, 1 Central Avenue, Australian Technology Park, Eveleigh, NSW, 1430, Australia
| | - Gregory C Fanning
- Johnson and Johnson Research Pty Ltd, Level 4 Biomedical Building, 1 Central Avenue, Australian Technology Park, Eveleigh, NSW, 1430, Australia
- Tibotec BVBA, Gen De Wittelaan L 11 B3, 2800 Mechelen, Belgium
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Zhan T, Digel M, Küch EM, Stremmel W, Füllekrug J. Silybin and dehydrosilybin decrease glucose uptake by inhibiting GLUT proteins. J Cell Biochem 2011; 112:849-59. [DOI: 10.1002/jcb.22984] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Mcintyre GJ, Groneman JL, Yu YH, Tran A, Applegate TL. Multiple shRNA combinations for near-complete coverage of all HIV-1 strains. AIDS Res Ther 2011; 8:1. [PMID: 21226969 PMCID: PMC3033792 DOI: 10.1186/1742-6405-8-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Accepted: 01/13/2011] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Combinatorial RNA interference (co-RNAi) approaches are needed to account for viral variability in treating HIV-1 with RNAi, as single short hairpin RNAs (shRNA) are rapidly rendered ineffective by resistant strains. Current work suggests that 4 simultaneously expressed shRNAs may prevent the emergence of resistant strains. RESULTS In this study we assembled combinations of highly-conserved shRNAs to target as many HIV-1 strains as possible. We analyzed intersecting conservations of 10 shRNAs to find combinations with 4+ matching the maximum number of strains using 1220+ HIV-1 sequences from the Los Alamos National Laboratory (LANL). We built 26 combinations of 2 to 7 shRNAs with up to 87% coverage for all known strains and 100% coverage of clade B subtypes, and characterized their intrinsic suppressive activities in transient expression assays. We found that all combinations had high combined suppressive activities, though there were also large changes in the individual activities of the component shRNAs in our multiple expression cassette configurations. CONCLUSION By considering the intersecting conservations of shRNA combinations we have shown that it is possible to assemble combinations of 6 and 7 highly active, highly conserved shRNAs such that there is always at least 4 shRNAs within each combination covering all currently known variants of entire HIV-1 subtypes. By extension, it may be possible to combine several combinations for complete global coverage of HIV-1 variants.
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Affiliation(s)
- Glen J Mcintyre
- Johnson and Johnson Research Pty Ltd, Level 4 Biomedical Building, 1 Central Avenue, Australian Technology Park, Eveleigh, NSW, 1430, Australia
| | - Jennifer L Groneman
- Johnson and Johnson Research Pty Ltd, Level 4 Biomedical Building, 1 Central Avenue, Australian Technology Park, Eveleigh, NSW, 1430, Australia
| | - Yi-Hsin Yu
- Johnson and Johnson Research Pty Ltd, Level 4 Biomedical Building, 1 Central Avenue, Australian Technology Park, Eveleigh, NSW, 1430, Australia
| | - Anna Tran
- Johnson and Johnson Research Pty Ltd, Level 4 Biomedical Building, 1 Central Avenue, Australian Technology Park, Eveleigh, NSW, 1430, Australia
| | - Tanya L Applegate
- Johnson and Johnson Research Pty Ltd, Level 4 Biomedical Building, 1 Central Avenue, Australian Technology Park, Eveleigh, NSW, 1430, Australia
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Lee SH, Mok H, Jo S, Hong CA, Park TG. Dual gene targeted multimeric siRNA for combinatorial gene silencing. Biomaterials 2010; 32:2359-68. [PMID: 21183215 DOI: 10.1016/j.biomaterials.2010.11.062] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Accepted: 11/26/2010] [Indexed: 11/27/2022]
Abstract
Simultaneous silencing of multiple up-regulated genes is an attractive and viable strategy to treat many incurable diseases including cancer. Herein we report that multimerized siRNA conjugate composed of two different siRNA sequences in the same backbone shows more efficient inhibition of the two corresponding target genes at one time than physically mixed multimerized siRNA conjugates. Two model siRNAs against VEGF and GFP gene were chemically crosslinked via cleavable and noncleavable linkages for the preparation of dual gene targeted multimeric siRNA conjugates (DGT multi-siRNA). Cleavable DGT multi-siRNA with reducible disulfide linkages exhibited significantly higher gene silencing efficiencies at mRNA and protein expression levels than noncleavable DGT multi-siRNA, the physical mixture of naked siRNA, and that of single gene targeted multimeric siRNA (SGT multi-siRNA) with eliciting negligible immune response. DGT multi-siRNAs against two therapeutic siRNAs, anti-survivin and anti-bcl-2 targeted siRNA, also showed greatly enhanced apoptotic effect. This approach for concurrent suppression of combinatorial therapeutic target genes using cleavable multimeric siRNA structure can be potentially used for improved therapeutic efficacy.
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Affiliation(s)
- Soo Hyeon Lee
- Department of Biological Sciences, The Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea
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Herzog M, Storch CH, Gut P, Kotlyar D, Füllekrug J, Ehehalt R, Haefeli WE, Weiss J. Knockdown of caveolin-1 decreases activity of breast cancer resistance protein (BCRP/ABCG2) and increases chemotherapeutic sensitivity. Naunyn Schmiedebergs Arch Pharmacol 2010; 383:1-11. [PMID: 20936466 DOI: 10.1007/s00210-010-0568-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Accepted: 09/22/2010] [Indexed: 12/18/2022]
Abstract
The ATP-binding cassette transporter breast cancer resistance protein (BCRP/ABCG2) is supposed to be a major determinant of the multidrug resistance phenotype of tumors by extruding chemically diverse cytostatic drugs out of tumor cells. BCRP physically and possibly also functionally interacts with caveolin-1 (CAV1, encoded by Cav1), an integral membrane protein of lipid rafts important for signal transduction and membrane trafficking. Moreover, Cav1 is linked to an aggressive phenotype of cancer cells in various tumors. We therefore investigated whether Cav1 plays a functional role in the regulation of BCRP transport activity and in the resistance against chemotherapeutics that are BCRP substrates. As a cell model, we used the BCRP overexpressing cell line MDCKII-BCRP and the corresponding parental cell line MDCKII as a control. Cav1 expression was down-regulated using retrovirus-mediated RNA interference technology. BCRP activity was assessed by pheophorbide A efflux assay and the resistance towards cytostatic drugs was measured by proliferation assays. Efficient knockdown of Cav1 reduced Cav1 expression by 85-95% and BCRP activity by 35%. Concurrently, it reduced resistance towards the BCRP substrate mitoxantrone but not towards vincristine, a chemotherapeutic that is not extruded by BCRP. Western blot analysis of gradient ultracentrifugation fractions and immunofluorescence demonstrates that BCRP localization within the plasma membrane was largely unaltered in Cav1-deficient cells compared to controls. The diminished BCRP function after Cav1 knockdown is, thus, likely mediated by alterations in protein-protein interactions and suggests a positive regulation of BCRP function by CAV1.
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Affiliation(s)
- Melanie Herzog
- Department of Clinical Pharmacology and Pharmacoepidemiology, University of Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
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Bryant DM, Datta A, Rodríguez-Fraticelli AE, Peränen J, Martín-Belmonte F, Mostov KE. A molecular network for de novo generation of the apical surface and lumen. Nat Cell Biol 2010; 12:1035-45. [PMID: 20890297 DOI: 10.1038/ncb2106] [Citation(s) in RCA: 463] [Impact Index Per Article: 33.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2010] [Accepted: 07/30/2010] [Indexed: 12/14/2022]
Abstract
To form epithelial organs cells must polarize and generate de novo an apical domain and lumen. Epithelial polarization is regulated by polarity complexes that are hypothesized to direct downstream events, such as polarized membrane traffic, although this interconnection is not well understood. We have found that Rab11a regulates apical traffic and lumen formation through the Rab guanine nucleotide exchange factor (GEF), Rabin8, and its target, Rab8a. Rab8a and Rab11a function through the exocyst to target Par3 to the apical surface, and control apical Cdc42 activation through the Cdc42 GEF, Tuba. These components assemble at a transient apical membrane initiation site to form the lumen. This Rab11a-directed network directs Cdc42-dependent apical exocytosis during lumen formation, revealing an interaction between the machineries of vesicular transport and polarization.
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Affiliation(s)
- David M Bryant
- Department of Anatomy, University of California, San Francisco, CA 94143-2140, USA
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Li J, Guo H, Shi Z, Tu C. In vitro inhibition of CSFV replication by retroviral vector-mediated RNA interference. J Virol Methods 2010; 169:316-21. [PMID: 20691206 PMCID: PMC7112837 DOI: 10.1016/j.jviromet.2010.07.036] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2010] [Revised: 07/28/2010] [Accepted: 07/29/2010] [Indexed: 11/30/2022]
Abstract
Classical swine fever (CSF) is a highly contagious viral disease of pigs which causes major economic losses worldwide. No specific drug is currently available for the effective treatment of CSFV infection. RNA interference (RNAi) technology depends on effective delivery systems, for which several effective vectors have recently been developed. Three retroviral plasmids containing siRNA genes targeting different regions of Npro and NS4A have been constructed, and 3 replication-incompetent retroviral vectors have been produced in the human embryo kidney cell line GP2-293 by retroviral plasmid transfection. PK-15 cells were then infected with these replication-incompetent retroviral vectors and screened for siRNA stably expressing PK-15 cell clones. Growth of CSFV in such siRNA stably expressing cell clones resulted in a 186-fold reduction in viral genome copies and, at 72 h post-infection, only a small % of cells showed infection by indirect immunofluorescence microscopy, and effective inhibition of virus replication persisted for up to 120 h. Retroviral vector-mediated RNAi can therefore be used to study the specific function of viral genes associated with CSFV replication and may have potential therapeutic application.
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Affiliation(s)
- Jiangnan Li
- College of Animal Science and Veterinary Medicine, Jilin University, 5333 XiAn Da Road, Changchun 130062, China
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Sun L, Hemgård GV, Susanto SA, Wirth M. Caveolin-1 influences human influenza A virus (H1N1) multiplication in cell culture. Virol J 2010; 7:108. [PMID: 20504340 PMCID: PMC2889940 DOI: 10.1186/1743-422x-7-108] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Accepted: 05/26/2010] [Indexed: 11/18/2022] Open
Abstract
Background The threat of recurring influenza pandemics caused by new viral strains and the occurrence of escape mutants necessitate the search for potent therapeutic targets. The dependence of viruses on cellular factors provides a weak-spot in the viral multiplication strategy and a means to interfere with viral multiplication. Results Using a motif-based search strategy for antiviral targets we identified caveolin-1 (Cav-1) as a putative cellular interaction partner of human influenza A viruses, including the pandemic influenza A virus (H1N1) strains of swine origin circulating from spring 2009 on. The influence of Cav-1 on human influenza A/PR/8/34 (H1N1) virus replication was determined in inhibition and competition experiments. RNAi-mediated Cav-1 knock-down as well as transfection of a dominant-negative Cav-1 mutant results in a decrease in virus titre in infected Madin-Darby canine kidney cells (MDCK), a cell line commonly used in basic influenza research as well as in virus vaccine production. To understand the molecular basis of the phenomenon we focussed on the putative caveolin-1 binding domain (CBD) located in the lumenal, juxtamembranal portion of the M2 matrix protein which has been identified in the motif-based search. Pull-down assays and co-immunoprecipitation experiments showed that caveolin-1 binds to M2. The data suggest, that Cav-1 modulates influenza virus A replication presumably based on M2/Cav-1 interaction. Conclusion As Cav-1 is involved in the human influenza A virus life cycle, the multifunctional protein and its interaction with M2 protein of human influenza A viruses represent a promising starting point for the search for antiviral agents.
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Affiliation(s)
- Lijing Sun
- Division of Molecular Biotechnology, Helmholtz-Centre for Infection Research, Inhoffenstr 7, 38124 Braunschweig, Germany
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Verma P, Ostermeyer-Fay AG, Brown DA. Caveolin-1 induces formation of membrane tubules that sense actomyosin tension and are inhibited by polymerase I and transcript release factor/cavin-1. Mol Biol Cell 2010; 21:2226-40. [PMID: 20427576 PMCID: PMC2893987 DOI: 10.1091/mbc.e09-05-0417] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We found that PTRF/cavin-1 is lost coordinately with caveolin-1 in some cancer cells. When reexpressed in these cells, caveolin-1 formed membrane tubules that were under actomyosin-induced tension and recruited Rab8 and EHD proteins. PTRF/cavin-1 inhibited tubule formation by caveolin-1, showing a new function for the protein. Caveolin-1 and caveolae are often lost in cancer. We found that levels of caveolin-1 and polymerase I and transcript release factor (PTRF)/cavin-1 correlated closely in a panel of cancer and normal cells. Caveolin-1 reexpression in cancer cells lacking both proteins induced formation of long membrane tubules rarely seen in normal cells. PTRF/cavin-1 inhibited tubule formation when coexpressed with caveolin-1 in these cells, whereas suppression of PTRF/cavin-1 expression in cells that normally expressed both genes stimulated tubule formation by endogenous caveolin-1. Caveolin-1 tubules shared several features with previously described Rab8 tubules. Coexpressed Rab8 and caveolin-1 labeled the same tubules (as did EHD proteins), and synergized to promote tubule formation, whereas a dominant-interfering Rab8 mutant inhibited caveolin-1 tubule formation. Both overexpression and inhibition of dynamin-2 reduced the abundance of caveolin-1 tubules. Caveolin-1 reexpression in SK-BR-3 breast cancer cells also induced formation of short membrane tubules close to cortical actin filaments, which required actin filaments but not microtubules. Actomyosin-induced tension destabilized both long and short tubules; they often snapped and resolved to small vesicles. Actin filament depolymerization or myosin II inhibition reduced tension and stabilized tubules. These data demonstrate a new function for PTRF/cavin-1, a new functional interaction between caveolin-1 and Rab8 and that actomyosin interactions can induce tension on caveolin-1-containing membranes.
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Affiliation(s)
- Prakhar Verma
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794-5215, USA
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Cardoso CMP, Jordao L, Vieira OV. Rab10 Regulates Phagosome Maturation and Its Overexpression RescuesMycobacterium-Containing Phagosomes Maturation. Traffic 2010; 11:221-35. [DOI: 10.1111/j.1600-0854.2009.01013.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Internalization of coxsackievirus A9 is mediated by {beta}2-microglobulin, dynamin, and Arf6 but not by caveolin-1 or clathrin. J Virol 2010; 84:3666-81. [PMID: 20089652 DOI: 10.1128/jvi.01340-09] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Coxsackievirus A9 (CAV9) is a member of the human enterovirus B species within the Enterovirus genus of the family Picornaviridae. It has been shown to utilize alphaV integrins, particularly alphaVbeta6, as its receptors. The endocytic pathway by which CAV9 enters human cells after the initial attachment to the cell surface has so far been unknown. Here, we present a systematic study concerning the internalization mechanism of CAV9 to A549 human lung carcinoma cells. The small interfering RNA (siRNA) silencing of integrin beta6 subunit inhibited virus proliferation, confirming that alphaVbeta6 mediates the CAV9 infection. However, siRNAs against integrin-linked signaling molecules, such as Src, Fyn, RhoA, phosphatidylinositol 3-kinase, and Akt1, did not reduce CAV9 proliferation, suggesting that the internalization of the virus does not involve integrin-linked signaling events. CAV9 endocytosis was independent of clathrin or caveolin-1 but was restrained by dynasore, an inhibitor of dynamin. The RNA interference silencing of beta2-microglobulin efficiently inhibited virus infection and caused CAV9 to accumulate on the cell surface. Furthermore, CAV9 infection was found to depend on Arf6 as both silencing of this molecule by siRNA and the expression of a dominant negative construct resulted in decreased virus infection. In conclusion, the internalization of CAV9 to A549 cells follows an endocytic pathway that is dependent on integrin alphaVbeta6, beta2-microglobulin, dynamin, and Arf6 but independent of clathrin and caveolin-1.
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Mcintyre GJ, Yu YH, Tran A, Jaramillo AB, Arndt AJ, Millington ML, Boyd MP, Elliott FA, Shen SW, Murray JM, Applegate TL. Cassette deletion in multiple shRNA lentiviral vectors for HIV-1 and its impact on treatment success. Virol J 2009; 6:184. [PMID: 19878571 PMCID: PMC2775741 DOI: 10.1186/1743-422x-6-184] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2009] [Accepted: 10/30/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Multiple short hairpin RNA (shRNA) gene therapy strategies are currently being investigated for treating viral diseases such as HIV-1. It is important to use several different shRNAs to prevent the emergence of treatment-resistant strains. However, there is evidence that repeated expression cassettes delivered via lentiviral vectors may be subject to recombination-mediated repeat deletion of 1 or more cassettes. RESULTS The aim of this study was to determine the frequency of deletion for 2 to 6 repeated shRNA cassettes and mathematically model the outcomes of different frequencies of deletion in gene therapy scenarios. We created 500+ clonal cell lines and found deletion frequencies ranging from 2 to 36% for most combinations. While the central positions were the most frequently deleted, there was no obvious correlation between the frequency or extent of deletion and the number of cassettes per combination. We modeled the progression of infection using combinations of 6 shRNAs with varying degrees of deletion. Our in silico modeling indicated that if at least half of the transduced cells retained 4 or more shRNAs, the percentage of cells harboring multiple-shRNA resistant viral strains could be suppressed to < 0.1% after 13 years. This scenario afforded a similar protection to all transduced cells containing the full complement of 6 shRNAs. CONCLUSION Deletion of repeated expression cassettes within lentiviral vectors of up to 6 shRNAs can be significant. However, our modeling showed that the deletion frequencies observed here for 6x shRNA combinations was low enough that the in vivo suppression of replication and escape mutants will likely still be effective.
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Affiliation(s)
- Glen J Mcintyre
- Johnson and Johnson Research Pty Ltd, Level 4 Biomedical Building, 1 Central Avenue, Australian Technology Park, Eveleigh, NSW, 1430, Australia
| | - Yi-Hsin Yu
- Johnson and Johnson Research Pty Ltd, Level 4 Biomedical Building, 1 Central Avenue, Australian Technology Park, Eveleigh, NSW, 1430, Australia
| | - Anna Tran
- Johnson and Johnson Research Pty Ltd, Level 4 Biomedical Building, 1 Central Avenue, Australian Technology Park, Eveleigh, NSW, 1430, Australia
| | - Angel B Jaramillo
- Johnson and Johnson Research Pty Ltd, Level 4 Biomedical Building, 1 Central Avenue, Australian Technology Park, Eveleigh, NSW, 1430, Australia
| | - Allison J Arndt
- Johnson and Johnson Research Pty Ltd, Level 4 Biomedical Building, 1 Central Avenue, Australian Technology Park, Eveleigh, NSW, 1430, Australia
| | - Michelle L Millington
- Johnson and Johnson Research Pty Ltd, Level 4 Biomedical Building, 1 Central Avenue, Australian Technology Park, Eveleigh, NSW, 1430, Australia
| | - Maureen P Boyd
- Johnson and Johnson Research Pty Ltd, Level 4 Biomedical Building, 1 Central Avenue, Australian Technology Park, Eveleigh, NSW, 1430, Australia
| | - Fiona A Elliott
- Johnson and Johnson Research Pty Ltd, Level 4 Biomedical Building, 1 Central Avenue, Australian Technology Park, Eveleigh, NSW, 1430, Australia
| | - Sylvie W Shen
- Johnson and Johnson Research Pty Ltd, Level 4 Biomedical Building, 1 Central Avenue, Australian Technology Park, Eveleigh, NSW, 1430, Australia
| | - John M Murray
- School of Mathematics and Statistics, The University of New South Wales, Sydney, NSW, 2052, Australia
- The National Center in HIV Epidemiology and Clinical Research, The University of New South Wales, 376 Victoria St. Darlinghurst, NSW, 2010, Australia
| | - Tanya L Applegate
- Johnson and Johnson Research Pty Ltd, Level 4 Biomedical Building, 1 Central Avenue, Australian Technology Park, Eveleigh, NSW, 1430, Australia
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Abstract
RNA interference (RNAi) is an ancient defensive mechanism in eukaryotes to control gene expressing and defend their genomes from foreign invaders. It refers to the phenomenon that double-stranded RNA results in the sequence-specific silencing of target gene expression. Although it was documented in a relatively short time ago, intensive research has facilitated making its mechanism clear. Researchers have found that it was a powerful tool for analyzing the functions of genes and treating tumors, infectious diseases and genetic abnormalities that are associated with a dominant gene defect. However, delivery in vivo, low blood stability and poor intracellular uptake present significant challenges for the development of RNAi reagents in clinical use. Thus, long-term inducible RNAi was designed. There are hundreds of millions of hepatitis B virus (HBV) carriers in the world at present, a portion of whom will lose their lives after several years due to chronic complications such as cirrhosis, hepatocellular carcinomas or both. Although a preventive vaccine is now available, the present therapeutic options for chronically infected patients are limited and of low efficiency. Admittedly, to date most RNAi experiments have been done in vitro, but it is hoped that they may be developed into a therapeutic strategy for HBV in the near future. In this article the principles and construction of long-term RNA are discussed. Its therapeutic potentiality and attention to the potential hazards will also outlined. We conclude that this ancient defensive mechanism can be recruited as a powerful weapon in the fight against HBV.
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Affiliation(s)
- Jin Shui Pan
- Department of Gastroenterology, Zhongshan Hospital Xiamen University, Xiamen, China
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Caveolae are required for protease-selective signaling by protease-activated receptor-1. Proc Natl Acad Sci U S A 2009; 106:6393-7. [PMID: 19332793 DOI: 10.1073/pnas.0810687106] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Protease-activated receptor-1 (PAR(1)) is a G-protein-coupled receptor uniquely activated by proteolysis. Thrombin, a coagulant protease, induces inflammatory responses and endothelial barrier permeability through the activation of PAR(1). Activated protein C (APC), an anti-coagulant protease, also activates PAR(1). However, unlike thrombin, APC elicits anti-inflammatory responses and protects against endothelial barrier dysfunction induced by thrombin. We found that thrombin and APC signaling were lost in PAR(1)-deficient endothelial cells, indicating that PAR(1) is the major effector of protease signaling. To delineate the mechanism responsible for protease-selective signaling by PAR(1), we examined the effect of APC and thrombin on the activation of RhoA and Rac1, small GTPases that differentially regulate endothelial barrier permeability. Thrombin caused robust RhoA signaling but not Rac1 activation, whereas APC stimulated a marked increase in Rac1 activation but not RhoA signaling, consistent with the opposing functions of these proteases on endothelial barrier integrity. Strikingly, APC signaling and endothelial barrier protection effects were abolished in cells lacking caveolin-1, whereas thrombin signaling remained intact. These findings suggest that compartmentalization of PAR(1) in caveolae is critical for APC selective signaling to Rac1 activation and endothelial barrier protection. We further report that APC induces PAR(1) phosphorylation and desensitizes endothelial cells to thrombin signaling but promotes limited receptor cleavage and negligible internalization and degradation even after prolonged APC exposure. Thus, APC selective signaling and endothelial barrier protective effects are mediated through compartmentalization of PAR(1) in caveolae and a novel mechanism of PAR(1) signal regulation.
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Zhang W, Li J, Allen SM, Weiskircher EA, Huang Y, George RA, Fong RG, Owen A, Hidalgo IJ. Silencing the breast cancer resistance protein expression and function in caco-2 cells using lentiviral vector-based short hairpin RNA. Drug Metab Dispos 2009; 37:737-44. [PMID: 19131524 DOI: 10.1124/dmd.108.023309] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A series of stable breast cancer resistance protein (BCRP, ABCG2) knockdown cell lines were produced by transduction of Caco-2 cells with lentiviral vector-based short hairpin RNA (shRNA). Caco-2 cell is a human intestinal-derived cell line widely used to study intestinal drug absorption. Caco-2 expresses three apical drug efflux transporters: BCRP, P-glycoprotein (P-gp; ABCB1), and multidrug resistance protein 2 (MRP2, ABCC2). BCRP and P-gp in particular play a significant role in pharmacokinetics because of their expression at several key interfaces. Overexpression of BCRP in cancer cells may also be a mechanism of tumor resistance to chemotherapeutic drugs. The goal of this study was to engineer and characterize Caco-2 cell clones with stable knockdown of BCRP expression. The shRNA/BCRP lentiviral particles were used to infect a stable clone of Caco-2 cells. Expression of BCRP was monitored using quantitative polymerase chain reaction (qPCR), Western blotting, immunofluorescence microscopy, and bidirectional transport of probe substrates, estrone-3-sulfate (E3S), and pheophorbide A (PhA). Based on qPCR, expression of BCRP mRNA was knocked down in five clones with a maximum of 97% silencing in clone D. Silencing of BCRP gene expression was maintained for at least 25 passages. Expression of BCRP protein was also reduced significantly. Functionally, BCRP knockdown was reflected in significant reduction of the efflux ratio of E3S and PhA. Clone D in particular should be a useful model for identifying and characterizing P-gp substrates and inhibitors without interference from BCRP and/or MRP2. In addition, it can be used in conjunction with wild-type or vector control Caco-2 cells to identify BCRP substrates.
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Affiliation(s)
- Wei Zhang
- Absorption Systems, LP, 436 Creamery Way, Suite 600, Exton, PA 19341, USA
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