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Liashkovich I, Stefanello ST, Vidyadharan R, Haufe G, Erofeev A, Gorelkin PV, Kolmogorov V, Mizdal CR, Dulebo A, Bulk E, Kouzel IU, Shahin V. Pitstop-2 and its novel derivative RVD-127 disrupt global cell dynamics and nuclear pores integrity by direct interaction with small GTPases. Bioeng Transl Med 2023; 8:e10425. [PMID: 37476059 PMCID: PMC10354767 DOI: 10.1002/btm2.10425] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 09/26/2022] [Accepted: 10/03/2022] [Indexed: 07/22/2023] Open
Abstract
Clathrin-mediated endocytosis (CME) is an essential cell physiological process of broad biomedical relevance. Since the recent introduction of Pitstop-2 as a potent CME inhibitor, we and others have reported on substantial clathrin-independent inhibitory effects. Herein, we developed and experimentally validated a novel fluorescent derivative of Pitstop-2, termed RVD-127, to clarify Pitstop-2 diverse effects. Using RVD-127, we were able to trace additional protein targets of Pitstop-2. Besides inhibiting CME, Pitstop-2 and RVD-127 proved to directly and reversibly bind to at least two members of the small GTPase superfamily Ran and Rac1 with particularly high efficacy. Binding locks the GTPases in a guanosine diphosphate (GDP)-like conformation disabling their interaction with their downstream effectors. Consequently, overall cell motility, mechanics and nucleocytoplasmic transport integrity are rapidly disrupted at inhibitor concentrations well below those required to significantly reduce CME. We conclude that Pitstop-2 is a highly potent, reversible inhibitor of small GTPases. The inhibition of these molecular switches of diverse crucial signaling pathways, including nucleocytoplasmic transport and overall cell dynamics and motility, clarifies the diversity of Pitstop-2 activities. Moreover, considering the fundamental importance and broad implications of small GTPases in physiology, pathophysiology and drug development, Pitstop-2 and RVD-127 open up novel avenues.
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Affiliation(s)
| | | | | | - Günter Haufe
- Organic Chemistry Institute, University of MünsterMünsterGermany
| | - Alexander Erofeev
- National University of Science and Technology «MISiS»MoscowRussia
- Department of ChemistryLomonosov Moscow State UniversityMoscowRussia
| | | | | | | | | | - Etmar Bulk
- Institute of Physiology II, University of MünsterMünsterGermany
| | | | - Victor Shahin
- Institute of Physiology II, University of MünsterMünsterGermany
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2
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Kummer D, Steinbacher T, Thölmann S, Schwietzer MF, Hartmann C, Horenkamp S, Demuth S, Peddibhotla SS, Brinkmann F, Kemper B, Schnekenburger J, Brandt M, Betz T, Liashkovich I, Kouzel IU, Shahin V, Corvaia N, Rottner K, Tarbashevich K, Raz E, Greune L, Schmidt MA, Gerke V, Ebnet K. A JAM-A-tetraspanin-αvβ5 integrin complex regulates contact inhibition of locomotion. J Biophys Biochem Cytol 2022; 221:213070. [PMID: 35293964 PMCID: PMC8931538 DOI: 10.1083/jcb.202105147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 12/16/2021] [Accepted: 01/21/2022] [Indexed: 12/30/2022] Open
Abstract
Contact inhibition of locomotion (CIL) is a process that regulates cell motility upon collision with other cells. Improper regulation of CIL has been implicated in cancer cell dissemination. Here, we identify the cell adhesion molecule JAM-A as a central regulator of CIL in tumor cells. JAM-A is part of a multimolecular signaling complex in which tetraspanins CD9 and CD81 link JAM-A to αvβ5 integrin. JAM-A binds Csk and inhibits the activity of αvβ5 integrin-associated Src. Loss of JAM-A results in increased activities of downstream effectors of Src, including Erk1/2, Abi1, and paxillin, as well as increased activity of Rac1 at cell-cell contact sites. As a consequence, JAM-A-depleted cells show increased motility, have a higher cell-matrix turnover, and fail to halt migration when colliding with other cells. We also find that proper regulation of CIL depends on αvβ5 integrin engagement. Our findings identify a molecular mechanism that regulates CIL in tumor cells and have implications on tumor cell dissemination.
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Affiliation(s)
- Daniel Kummer
- Institute-associated Research Group “Cell Adhesion and Cell Polarity”, Münster, Germany,Institute of Medical Biochemistry, ZMBE, University of Münster, Münster, Germany,Interdisciplinary Clinical Research Center (IZKF), University of Münster, Münster, Germany
| | - Tim Steinbacher
- Institute-associated Research Group “Cell Adhesion and Cell Polarity”, Münster, Germany,Institute of Medical Biochemistry, ZMBE, University of Münster, Münster, Germany
| | - Sonja Thölmann
- Institute-associated Research Group “Cell Adhesion and Cell Polarity”, Münster, Germany,Institute of Medical Biochemistry, ZMBE, University of Münster, Münster, Germany
| | - Mariel Flavia Schwietzer
- Institute-associated Research Group “Cell Adhesion and Cell Polarity”, Münster, Germany,Institute of Medical Biochemistry, ZMBE, University of Münster, Münster, Germany
| | - Christian Hartmann
- Institute-associated Research Group “Cell Adhesion and Cell Polarity”, Münster, Germany,Institute of Medical Biochemistry, ZMBE, University of Münster, Münster, Germany
| | - Simone Horenkamp
- Institute-associated Research Group “Cell Adhesion and Cell Polarity”, Münster, Germany,Institute of Medical Biochemistry, ZMBE, University of Münster, Münster, Germany
| | - Sabrina Demuth
- Institute-associated Research Group “Cell Adhesion and Cell Polarity”, Münster, Germany,Institute of Medical Biochemistry, ZMBE, University of Münster, Münster, Germany
| | - Swetha S.D. Peddibhotla
- Institute-associated Research Group “Cell Adhesion and Cell Polarity”, Münster, Germany,Institute of Medical Biochemistry, ZMBE, University of Münster, Münster, Germany
| | - Frauke Brinkmann
- Institute-associated Research Group “Cell Adhesion and Cell Polarity”, Münster, Germany,Institute of Medical Biochemistry, ZMBE, University of Münster, Münster, Germany
| | - Björn Kemper
- Biomedical Technology Center, Medical Faculty, University of Münster, Münster, Germany
| | - Jürgen Schnekenburger
- Biomedical Technology Center, Medical Faculty, University of Münster, Münster, Germany
| | - Matthias Brandt
- Institute-associated Research Group “Mechanics of Cellular Systems”, Institute of Cell Biology, ZMBE, University of Münster, Münster, Germany
| | - Timo Betz
- Institute-associated Research Group “Mechanics of Cellular Systems”, Institute of Cell Biology, ZMBE, University of Münster, Münster, Germany
| | - Ivan Liashkovich
- Institute of Physiology II, University of Münster, Münster, Germany
| | - Ivan U. Kouzel
- Sars International Centre for Marine Molecular Biology University of Bergen Thormøhlensgt, Bergen, Norway
| | - Victor Shahin
- Institute of Physiology II, University of Münster, Münster, Germany
| | - Nathalie Corvaia
- Centre d’Immunologie Pierre Fabre (CIPF), Saint-Julien-en-Genevois, France
| | - Klemens Rottner
- Divison of Molecular Cell Biology, Zoological Institute, Technical University Braunschweig, Braunschweig, Germany,Molecular Cell Biology Group, Department of Cell Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | | | - Erez Raz
- Institute of Cell Biology, ZMBE, University of Münster, Münster, Germany,Cells-in-Motion Cluster of Excellence (EXC 1003—CiM), University of Münster, 48419 Münster, Germany
| | - Lilo Greune
- Institute of Infectiology, ZMBE, University of Münster, Münster, Germany
| | | | - Volker Gerke
- Institute of Medical Biochemistry, ZMBE, University of Münster, Münster, Germany,Cells-in-Motion Cluster of Excellence (EXC 1003—CiM), University of Münster, 48419 Münster, Germany
| | - Klaus Ebnet
- Institute-associated Research Group “Cell Adhesion and Cell Polarity”, Münster, Germany,Institute of Medical Biochemistry, ZMBE, University of Münster, Münster, Germany,Interdisciplinary Clinical Research Center (IZKF), University of Münster, Münster, Germany,Cells-in-Motion Cluster of Excellence (EXC 1003—CiM), University of Münster, 48419 Münster, Germany
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3
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Liashkovich I, Rosso G, Shahin V. Atomic Force Microscopy for Structural and Biophysical Investigations on Nuclear Pore Complexes. Methods Mol Biol 2022; 2502:299-310. [PMID: 35412247 DOI: 10.1007/978-1-0716-2337-4_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Atomic force microscopy (AFM) enables simultaneous generation of topographical and biophysical maps of surfaces of biological samples at nanoresolution in physiologically relevant environments. Here, we describe the application of AFM to study nuclear pore complexes from structural and biophysical aspects.
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Affiliation(s)
- Ivan Liashkovich
- Institute of Physiology II, University of Münster, Münster, Germany
| | - Gonzalo Rosso
- Institute of Physiology II, University of Münster, Münster, Germany
| | - Victor Shahin
- Institute of Physiology II, University of Münster, Münster, Germany.
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4
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Stefanello ST, Luchtefeld I, Liashkovich I, Pethö Z, Azzam I, Bulk E, Rosso G, Döhlinger L, Hesse B, Oeckinghaus A, Shahin V. Impact of the Nuclear Envelope on Malignant Transformation, Motility, and Survival of Lung Cancer Cells. Adv Sci (Weinh) 2021; 8:e2102757. [PMID: 34658143 PMCID: PMC8596107 DOI: 10.1002/advs.202102757] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 08/11/2021] [Indexed: 05/08/2023]
Abstract
Nuclear pore complexes (NPCs) selectively mediate all nucleocytoplasmic transport and engage in fundamental cell-physiological processes. It is hypothesized that NPCs are critical for malignant transformation and survival of lung cancer cells, and test the hypothesis in lowly and highly metastatic non-small human lung cancer cells (NSCLCs). It is shown that malignant transformation is paralleled by an increased NPCs density, and a balanced pathological weakening of the physiological stringency of the NPC barrier. Pharmacological interference using barrier-breaking compounds collapses the stringency. Concomitantly, it induces drastic overall structural changes of NSCLCs, terminating their migration. Moreover, the degree of malignancy is found to be paralleled by substantially decreased lamin A/C levels. The latter provides crucial structural and mechanical stability to the nucleus, and interacts with NPCs, cytoskeleton, and nucleoskeleton for cell maintenance, survival, and motility. The recent study reveals the physiological importance of the NPC barrier stringency for mechanical and structural resilience of normal cell nuclei. Hence, reduced lamin A/C levels in conjunction with controlled pathological weakening of the NPC barrier stringency may facilitate deformability of NSCLCs during the metastasis steps. Modulation of the NPC barrier presents a potential strategy for suppressing the malignant phenotype or enhancing the effectiveness of currently existing chemotherapeutics.
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Affiliation(s)
- Sílvio Terra Stefanello
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, Münster, 48149, Germany
| | - Isabelle Luchtefeld
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, Münster, 48149, Germany
| | - Ivan Liashkovich
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, Münster, 48149, Germany
| | - Zoltan Pethö
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, Münster, 48149, Germany
| | - Ihab Azzam
- Institute of Immunology, University of Münster, Röntgen-Str. 21, Münster, 48149, Germany
| | - Etmar Bulk
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, Münster, 48149, Germany
| | - Gonzalo Rosso
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, Münster, 48149, Germany
| | - Lilly Döhlinger
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, Münster, 48149, Germany
| | - Bettina Hesse
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, Münster, 48149, Germany
| | - Andrea Oeckinghaus
- Institute of Molecular Tumor Biology, University of Münster, Robert-Koch-Str. 43, Münster, 48149, Germany
| | - Victor Shahin
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, Münster, 48149, Germany
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5
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Keurhorst D, Liashkovich I, Frontzek F, Nitzlaff S, Hofschröer V, Dreier R, Stock C. MMP3 activity rather than cortical stiffness determines NHE1-dependent invasiveness of melanoma cells. Cancer Cell Int 2019; 19:285. [PMID: 31728131 PMCID: PMC6842528 DOI: 10.1186/s12935-019-1015-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 11/01/2019] [Indexed: 12/31/2022] Open
Abstract
Background Both cell adhesion and matrix metalloproteinase (MMP) activity depend on pH at the cell surface. By regulating extracellular juxtamembrane pH, the Na+/H+ exchanger NHE1 plays a significant part in human melanoma (MV3) cell migration and invasion. Because NHE1, besides its pH-regulatory transport function, also serves as a structural element tying the cortical actin cytoskeleton to the plasma membrane, we investigated whether NHE1 affects cortical stiffness of MV3 cells, and how this makes an impact on their invasiveness. Methods NHE1 overexpressing MV3 cells were compared to the corresponding mock-transfected control cells. NHE1 expression was verified by Western blotting, cariporide (HOE642) was used to inhibit NHE1 activity, cell stiffness was determined by atomic force microscopy, and F-actin was visualized by phalloidin-staining. Migration on, and invasion of, native and glutaraldehyde-fixed collagen I substrates were analyzed using time-lapse video microscopy and Boyden-chamber assays, respectively. MMP secretion and activity were detected by Western blot and zymography, respectively. MMP activity was inhibited with NNGH. Results The cortical, but not the bulk stiffness, was significantly higher in NHE1 overexpressing cells. This increase in cortical stiffness was accompanied by a reorganization of the cortical cytoskeleton, i.e. a condensation of F-actin underneath and along the plasma membrane. However, it was not affected by NHE1 inhibition. Nevertheless, actin dynamics is required for cell invasion as demonstrated with the application of cytochalasin D. NHE1 overexpression was associated with an elevated MMP3 secretion and an increase in the invasion of a native matrix. This increase in invasiveness could be antagonized by the MMP inhibitor NNGH. Transmigration through a glutaraldehyde-fixed, indigestible substrate was not affected by NHE1 overexpression. Conclusion NHE1, as a structural element and independently of its transport activity, contributes to the organization of the cortical F-actin meshwork and thus impacts cortical stiffness. Since NHE1 overexpression stimulates MMP3 secretion but does not change transmigration through a fixed substrate, MV3 cell invasion of a native substrate depends on MMP activity rather than on a modifiable cortical stiffness.
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Affiliation(s)
- Dennis Keurhorst
- 1Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, 48149 Münster, Germany
| | - Ivan Liashkovich
- 1Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, 48149 Münster, Germany
| | - Fabian Frontzek
- 2Department of Oncology and Hematology, University Hospital of Münster, Albert-Schweitzer-Campus 1, 48149 Münster, Germany
| | - Svenja Nitzlaff
- 3Institute of Animal Physiology, University of Münster, Schlossplatz 8, 48143 Münster, Germany
| | - Verena Hofschröer
- 1Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, 48149 Münster, Germany
| | - Rita Dreier
- 4Institute of Physiological Chemistry and Pathobiochemistry, University of Münster, Waldeyer-Str. 15, 48149 Münster, Germany
| | - Christian Stock
- 1Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, 48149 Münster, Germany.,5Department of Gastroenterology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
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6
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Shahin V, Kouzel IU, Rosso G, Liashkovich I. Nuclear Envelope Permeability Barrier as a Fast-Response Intracellular Mechanostat. Adv Sci (Weinh) 2019; 6:1900709. [PMID: 31728274 PMCID: PMC6839651 DOI: 10.1002/advs.201900709] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 07/26/2019] [Indexed: 05/23/2023]
Abstract
The nuclear envelope is an undisputed component of the intracellular mechanotransduction cascades which collect, process, and respond to mechanical stimuli from the environment. At the same time, the nuclear envelope performs the function of a selective barrier between the nuclear and cytoplasmic compartments. Although the mechanosensing and the barrier functions of the nuclear envelope have both been subjects of intense research, a possible reciprocal relationship between them is only beginning to emerge. In this report, the role of the nucleocytoplasmic permeability barrier is evaluated in nuclear mechanics. Using a combination of atomic force and confocal microscopy, the functional state of the nucleocytoplasmic permeability barrier and the nuclear mechanics is monitored. By modulating the stringency of the barrier and simulating the active transport imbalance across the nuclear envelope, the decisive impact of these parameters on nuclear mechanics is demonstrated. It is concluded that the nucleocytoplasmic barrier is the second essential component of the intracellular mechanostat function performed by the nuclear envelope.
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Affiliation(s)
- Victor Shahin
- Institute of Physiology IIUniversity of MünsterRobert‐Koch‐Str. 27b48149MünsterGermany
| | - Ivan U. Kouzel
- Sars International Centre for Marine Molecular BiologyUniversity of BergenThormøhlensgt. 55N‐5006BergenNorway
| | - Gonzalo Rosso
- Institute of Physiology IIUniversity of MünsterRobert‐Koch‐Str. 27b48149MünsterGermany
- Biotechnology CenterTechnical University DresdenTatzberg 47/4901307DresdenGermany
| | - Ivan Liashkovich
- Institute of Physiology IIUniversity of MünsterRobert‐Koch‐Str. 27b48149MünsterGermany
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7
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Azzam I, Liashkovich I, Luchtefeld I, Kouzel IU, Shahin V. Facilitating plasmid nuclear delivery by interfering with the selective nuclear pore barrier. Bioeng Transl Med 2019; 4:e10136. [PMID: 31572794 PMCID: PMC6764801 DOI: 10.1002/btm2.10136] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 05/22/2019] [Accepted: 06/10/2019] [Indexed: 11/20/2022] Open
Abstract
Nuclear pore complexes (NPCs) are sophisticated transporters assembled from diverse proteins termed nucleoporins (Nups). They control all nucleocytoplasmic transport and form a stringent barrier between the cytosol and the nucleus. While selective receptor-mediated transport enables translocation of macromolecules up to striking sizes approaching megadalton-scale, the upper cutoff for diffusion is at 40 kDa. Raising the cutoff is of particular importance for nuclear delivery of therapeutic nanoparticles, for example, gene and chemotherapy. In this work, we set out to present compounds capable of raising the cutoff to an extent enabling nuclear delivery of 6 kbp pDNA (150 kDa) in cultured human vascular endothelial cells. Of all tested compounds one is singled out, 1,6-hexanediol (1,6-HD). Our observations reveal that 1,6-HD facilitates nuclear delivery of pDNA in up to 10-20% of the tested cells, compared to no delivery at all in control conditions. It acts by interfering with bonds between Nups that occupy the NPC channel and confer transport selectivity. It also largely maintains cell viability even at high concentrations. We envisage that 1,6-HD may serve as a lead substance and usher in the design of potent new strategies to increase nuclear delivery of therapeutic nanoparticles.
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Affiliation(s)
- Ihab Azzam
- Institute of Physiology IIUniversity of MünsterMünsterGermany
| | | | | | | | - Victor Shahin
- Institute of Physiology IIUniversity of MünsterMünsterGermany
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8
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Rosso G, Liashkovich I, Shahin V. In Situ Investigation of Interrelationships Between Morphology and Biomechanics of Endothelial and Glial Cells and their Nuclei. Adv Sci (Weinh) 2019; 6:1801638. [PMID: 30643730 PMCID: PMC6325600 DOI: 10.1002/advs.201801638] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Indexed: 05/22/2023]
Abstract
Morphology and biomechanics of cells and nuclei are interlinked with one another and play key roles in fundamental physiological processes. While powerful approaches are available for performing separate morphological and biomechanical investigations on cells and nuclei, simultaneous investigations in situ are challenging. Here, an appropriate approach is presented based on the simultaneous combination of atomic force microscopy and confocal microscopy in situ. Two cell types with entirely different morphologies, physiological roles, and biomechanical environments are investigated: vascular endothelial cells (ECs) with dense cytoskeletal actin, and nervous system glial cells (Schwann cells (SCs)) with dense vimentin network. Results reveal that ECs and their nuclei show high pliability and tend to undergo deformation only at compression sites. SCs, in contrast, show greater ability to resist mechanical deformation. Likewise, SC nuclei are harder to deform than EC nuclei, despite that SC nuclei have significantly lower amounts of lamins A/C, which reportedly scale with nuclear stiffness. The morphology-biomechanics interrelationships in SCs, ECs, and their nuclei may be a key factor in ensuring their physiological functions. In adult SCs, mechanosensitivity is presumably traded for mechanical strength to protect the neurons they encase, whereas ECs maintain mechanosensitivity to ensure specific local physiological response to mechanical stimuli.
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Affiliation(s)
- Gonzalo Rosso
- Biotechnology CenterTechnische Universität DresdenTatzberg 47/4901307DresdenGermany
| | - Ivan Liashkovich
- Institute of Physiology IIUniversity of MünsterRobert‐Koch Str. 27b48149MünsterGermany
| | - Victor Shahin
- Institute of Physiology IIUniversity of MünsterRobert‐Koch Str. 27b48149MünsterGermany
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9
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Legros N, Pohlentz G, Steil D, Kouzel IU, Liashkovich I, Mellmann A, Karch H, Müthing J. Membrane assembly of Shiga toxin glycosphingolipid receptors and toxin refractiveness of MDCK II epithelial cells. J Lipid Res 2018; 59:1383-1401. [PMID: 29866658 DOI: 10.1194/jlr.m083048] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 05/22/2018] [Indexed: 12/16/2022] Open
Abstract
Shiga toxins (Stxs) are the major virulence factors of Stx-producing Escherichia coli (STEC), which cause hemorrhagic colitis and severe extraintestinal complications due to injury of renal endothelial cells, resulting in kidney failure. Since kidney epithelial cells are suggested additional targets for Stxs, we analyzed Madin-Darby canine kidney (MDCK) II epithelial cells for presence of Stx-binding glycosphingolipids (GSLs), determined their distribution to detergent-resistant membranes (DRMs), and ascertained the lipid composition of DRM and non-DRM preparations. Globotriaosylceramide and globotetraosylceramide, known as receptors for Stx1a, Stx2a, and Stx2e, and Forssman GSL as a specific receptor for Stx2e, were found to cooccur with SM and cholesterol in DRMs of MDCK II cells, which was shown using TLC overlay assay detection combined with mass spectrometry. The various lipoforms of GSLs were found to mainly harbor ceramide moieties composed of sphingosine (d18:1) and C24:1/C24:0 or C16:0 FA. The cells were highly refractory toward Stx1a, Stx2a, and Stx2e, most likely due to the absence of Stx-binding GSLs in the apical plasma membrane determined by immunofluorescence confocal laser scanning microscopy. The results suggest that the cellular content of Stx receptor GSLs and their biochemical detection in DRM preparations alone are inadequate to predict cellular sensitivity toward Stxs.
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Affiliation(s)
- Nadine Legros
- Institute for Hygiene, University of Münster, D-48149 Münster, Germany
| | | | - Daniel Steil
- Institute for Hygiene, University of Münster, D-48149 Münster, Germany
| | - Ivan U Kouzel
- Institute for Hygiene, University of Münster, D-48149 Münster, Germany.,Interdisciplinary Center for Clinical Research, University of Münster, D-48149 Münster, Germany
| | - Ivan Liashkovich
- Institute of Physiology II, University of Münster, D-48149 Münster, Germany
| | - Alexander Mellmann
- Institute for Hygiene, University of Münster, D-48149 Münster, Germany.,Interdisciplinary Center for Clinical Research, University of Münster, D-48149 Münster, Germany
| | - Helge Karch
- Institute for Hygiene, University of Münster, D-48149 Münster, Germany.,Interdisciplinary Center for Clinical Research, University of Münster, D-48149 Münster, Germany
| | - Johannes Müthing
- Institute for Hygiene, University of Münster, D-48149 Münster, Germany .,Interdisciplinary Center for Clinical Research, University of Münster, D-48149 Münster, Germany
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10
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Prystopiuk V, Fels B, Simon CS, Liashkovich I, Pasrednik D, Kronlage C, Wedlich-Söldner R, Oberleithner H, Fels J. A two-phase response of endothelial cells to hydrostatic pressure. J Cell Sci 2018; 131:jcs.206920. [DOI: 10.1242/jcs.206920] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 05/10/2018] [Indexed: 01/15/2023] Open
Abstract
The vascular endothelium is exposed to three types of mechanical forces: blood flow-mediated shear stress, vessel-diameter dependent wall tension and hydrostatic pressure. Despite considerable variations of blood pressure in normal and pathological physiology, little is known about the acute molecular and cellular effects of hydrostatic pressure on endothelial cells. Here, we used a combination of quantitative fluorescence microscopy, atomic force microscopy and molecular perturbations to characterize the specific response of endothelial cells to pressure application. We identified a two-phase response of endothelial cells to acute (1 h) vs. chronic (24 h) pressure application (100 mmHg). While both regimes induce cortical stiffening, the acute response is linked to calcium-mediated myosin activation, whereas the chronic cell response is dominated by increased cortical actin density and a loss in endothelial barrier function. GsMTx-4 and amiloride inhibit the acute pressure response, which suggest the sodium channel ENaC as key player in endothelial pressure sensing. The described two-phase pressure response may participate in the differential effects of transient changes in blood pressure and hypertension.
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Affiliation(s)
- Valeria Prystopiuk
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, 48149 Münster, Germany
- Cells-In-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, 48149, Münster, Germany
- current address: Institute of Life Sciences, Université Catholique de Louvain, Croix du Sud, 4-5, bte L7.07.06, Louvain-la-Neuve B-1348, Belgium
| | - Benedikt Fels
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, 48149 Münster, Germany
- Cells-In-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, 48149, Münster, Germany
| | - Caroline Sophie Simon
- Institute of Cell Dynamics and Imaging, University of Münster, Von-Esmarch-Str. 56, 48149 Münster, Germany
- Cells-In-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, 48149, Münster, Germany
| | - Ivan Liashkovich
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, 48149 Münster, Germany
- Cells-In-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, 48149, Münster, Germany
| | - Dzmitry Pasrednik
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, 48149 Münster, Germany
- Cells-In-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, 48149, Münster, Germany
| | - Cornelius Kronlage
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, 48149 Münster, Germany
- Cells-In-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, 48149, Münster, Germany
| | - Roland Wedlich-Söldner
- Institute of Cell Dynamics and Imaging, University of Münster, Von-Esmarch-Str. 56, 48149 Münster, Germany
- Cells-In-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, 48149, Münster, Germany
| | - Hans Oberleithner
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, 48149 Münster, Germany
- Cells-In-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, 48149, Münster, Germany
| | - Johannes Fels
- Institute of Cell Dynamics and Imaging, University of Münster, Von-Esmarch-Str. 56, 48149 Münster, Germany
- Cells-In-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, 48149, Münster, Germany
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Bulk E, Kramko N, Liashkovich I, Glaser F, Schillers H, Schnittler HJ, Oberleithner H, Schwab A. K Ca3.1 channel inhibition leads to an ICAM-1 dependent increase of cell-cell adhesion between A549 lung cancer and HMEC-1 endothelial cells. Oncotarget 2017; 8:112268-112282. [PMID: 29348824 PMCID: PMC5762509 DOI: 10.18632/oncotarget.22735] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 11/14/2017] [Indexed: 12/14/2022] Open
Abstract
Early metastasis leads to poor prognosis of lung cancer patients, whose 5-year survival rate is only 15%. We could recently show that the Ca2+ sensitive K+ channel KCa3.1 promotes aggressive behavior of non-small cell lung cancer (NSCLC) cells and that it can serve as a prognostic marker in NSCLC. Since NSCLC patients die of metastases, we investigated whether KCa3.1 channels contribute to poor patient prognosis by regulating distinct steps of the metastatic cascade. We investigated the extravasation of NSCLC cells and focused on their adhesion to endothelial cells and on transendothelial migration. We quantified the adhesion forces between NSCLC cells and endothelial cells by applying single cell force spectroscopy, and we monitored transendothelial migration using live-cell imaging. Inhibition of KCa3.1 channels with senicapoc or KCa3.1 silencing increases the adhesion force of A549 lung cancer cells to human microvascular endothelial cells (HMEC-1). Western blotting, immunofluorescence staining and biotinylation assays indicate that the elevated adhesion force is due to increased expression of ICAM-1 in both cell lines when KCa3.1 channels are downregulated. Consistent with this interpretation, an anti-ICAM-1 blocking antibody abolishes the KCa3.1-dependent increase in adhesion. Senicapoc inhibits transendothelial migration of A549 cells by 50%. Selectively silencing KCa3.1 channels in either NSCLC or endothelial cells reveals that transendothelial migration depends predominantly on endothelial KCa3.1 channels. In conclusion, our findings disclose a novel function of KCa3.1 channels in cancer. KCa3.1 channels regulate ICAM-1 dependent cell-cell adhesion between endothelial and cancer cells that affects the transmigration step of the metastatic cascade.
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Affiliation(s)
- Etmar Bulk
- Institute of Physiology II, University of Muenster, Münster, Germany
| | - Nadzeya Kramko
- Institute of Anatomy and Vascular Biology, University of Muenster, Münster, Germany
| | - Ivan Liashkovich
- Institute of Physiology II, University of Muenster, Münster, Germany
| | - Felix Glaser
- Institute of Physiology II, University of Muenster, Münster, Germany
| | - Hermann Schillers
- Institute of Physiology II, University of Muenster, Münster, Germany
| | | | - Hans Oberleithner
- Institute of Physiology II, University of Muenster, Münster, Germany
| | - Albrecht Schwab
- Institute of Physiology II, University of Muenster, Münster, Germany
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12
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Rosso G, Liashkovich I, Young P, Shahin V. Nano-scale Biophysical and Structural Investigations on Intact and Neuropathic Nerve Fibers by Simultaneous Combination of Atomic Force and Confocal Microscopy. Front Mol Neurosci 2017; 10:277. [PMID: 28912683 PMCID: PMC5582161 DOI: 10.3389/fnmol.2017.00277] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 08/17/2017] [Indexed: 11/14/2022] Open
Abstract
The links between neuropathies of the peripheral nervous system (PNS), including Charcot-Marie-Tooth1A and hereditary neuropathy with liability to pressure palsies, and impaired biomechanical and structural integrity of PNS nerves remain poorly understood despite the medical urgency. Here, we present a protocol describing simultaneous structural and biomechanical integrity investigations on isolated nerve fibers, the building blocks of nerves. Nerve fibers are prepared from nerves harvested from wild-type and exemplary PNS neuropathy mouse models. The basic principle of the designed experimental approach is based on the simultaneous combination of atomic force microscopy (AFM) and confocal microscopy. AFM is used to visualize the surface structure of nerve fibers at nano-scale resolution. The simultaneous combination of AFM and confocal microscopy is used to perform biomechanical, structural, and functional integrity measurements at nano- to micro-scale. Isolation of sciatic nerves and subsequent teasing of nerve fibers take ~45 min. Teased fibers can be maintained at 37°C in a culture medium and kept viable for up to 6 h allowing considerable time for all measurements which require 3–4 h. The approach is designed to be widely applicable for nerve fibers from mice of any PNS neuropathy. It can be extended to human nerve biopsies.
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Affiliation(s)
- Gonzalo Rosso
- Institute of Physiology II, WWU MünsterMünster, Germany
| | | | - Peter Young
- Department of Sleep Medicine and Neuromuscular DisordersMünster, Germany
| | - Victor Shahin
- Institute of Physiology II, WWU MünsterMünster, Germany
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13
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Rosso G, Liashkovich I, Young P, Röhr D, Shahin V. Schwann cells and neurite outgrowth from embryonic dorsal root ganglions are highly mechanosensitive. Nanomedicine: Nanotechnology, Biology and Medicine 2017; 13:493-501. [DOI: 10.1016/j.nano.2016.06.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 06/06/2016] [Accepted: 06/24/2016] [Indexed: 02/02/2023]
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14
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Liashkovich I, Pasrednik D, Prystopiuk V, Rosso G, Oberleithner H, Shahin V. Clathrin inhibitor Pitstop-2 disrupts the nuclear pore complex permeability barrier. Sci Rep 2015; 5:9994. [PMID: 25944393 PMCID: PMC4421796 DOI: 10.1038/srep09994] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 03/24/2015] [Indexed: 02/07/2023] Open
Abstract
Existence of a selective nucleocytoplasmic permeability barrier is attributed to Phenylalanine-Glycine rich proteins (FG-nups) within the central channel of the nuclear pore complex (NPC). Limited understanding of the FG-nup structural arrangement hinders development of strategies directed at disrupting the NPC permeability barrier. In this report we explore an alternative approach to enhancing the NPC permeability for exogenous macromolecules. We demonstrate that the recently discovered inhibitor of clathrin coat assembly Pitstop-2 compromises the NPC permeability barrier in a rapid and effective manner. Treatment with Pitstop-2 causes a collapse of the NPC permeability barrier and a reduction of Importin β binding accompanied by alteration of the NPC ultrastructure. Interestingly, the effects are induced by the same chemical agent that is capable of inhibiting clathrin-mediated endocytosis. To our knowledge, this is the first functional indication of the previously postulated evolutionary relation between clathrin and NPC scaffold proteins.
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Affiliation(s)
- Ivan Liashkovich
- Institute of Physiology II, Robert-Koch-Str. 27b, 48149 Münster, Germany
| | - Dzmitry Pasrednik
- Institute of Physiology II, Robert-Koch-Str. 27b, 48149 Münster, Germany
| | - Valeria Prystopiuk
- Institute of Physiology II, Robert-Koch-Str. 27b, 48149 Münster, Germany
| | - Gonzalo Rosso
- Institute of Physiology II, Robert-Koch-Str. 27b, 48149 Münster, Germany
| | - Hans Oberleithner
- Institute of Physiology II, Robert-Koch-Str. 27b, 48149 Münster, Germany
| | - Victor Shahin
- Institute of Physiology II, Robert-Koch-Str. 27b, 48149 Münster, Germany
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15
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Bestembayeva A, Kramer A, Labokha AA, Osmanović D, Liashkovich I, Orlova EV, Ford IJ, Charras G, Fassati A, Hoogenboom BW. Nanoscale stiffness topography reveals structure and mechanics of the transport barrier in intact nuclear pore complexes. Nat Nanotechnol 2015; 10:60-64. [PMID: 25420031 PMCID: PMC4286247 DOI: 10.1038/nnano.2014.262] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 10/13/2014] [Indexed: 05/17/2023]
Abstract
The nuclear pore complex (NPC) is the gate for transport between the cell nucleus and the cytoplasm. Small molecules cross the NPC by passive diffusion, but molecules larger than ∼5 nm must bind to nuclear transport receptors to overcome a selective barrier within the NPC. Although the structure and shape of the cytoplasmic ring of the NPC are relatively well characterized, the selective barrier is situated deep within the central channel of the NPC and depends critically on unstructured nuclear pore proteins, and is therefore not well understood. Here, we show that stiffness topography with sharp atomic force microscopy tips can generate nanoscale cross-sections of the NPC. The cross-sections reveal two distinct structures, a cytoplasmic ring and a central plug structure, which are consistent with the three-dimensional NPC structure derived from electron microscopy. The central plug persists after reactivation of the transport cycle and resultant cargo release, indicating that the plug is an intrinsic part of the NPC barrier. Added nuclear transport receptors accumulate on the intact transport barrier and lead to a homogenization of the barrier stiffness. The observed nanomechanical properties in the NPC indicate the presence of a cohesive barrier to transport and are quantitatively consistent with the presence of a central condensate of nuclear pore proteins in the NPC channel.
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Affiliation(s)
- Aizhan Bestembayeva
- London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London WC1H 0AH, United Kingdom
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Armin Kramer
- London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London WC1H 0AH, United Kingdom
- Institute of Physiology II, University of Münster, Robert-Koch Strasse 27b, 48149 Münster, Germany
| | - Aksana A. Labokha
- Wohl Virion Centre, Division of Infection & Immunity, MRC Centre for Medical Molecular Virology, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Dino Osmanović
- London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London WC1H 0AH, United Kingdom
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Ivan Liashkovich
- Institute of Physiology II, University of Münster, Robert-Koch Strasse 27b, 48149 Münster, Germany
| | - Elena V. Orlova
- Department of Biological Sciences, Birkbeck College, Institute of Structural and Molecular Biology, Malet Street, London WC1E 7HX, United Kingdom
| | - Ian J. Ford
- London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London WC1H 0AH, United Kingdom
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Guillaume Charras
- London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London WC1H 0AH, United Kingdom
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Ariberto Fassati
- Wohl Virion Centre, Division of Infection & Immunity, MRC Centre for Medical Molecular Virology, University College London, Gower Street, London WC1E 6BT, United Kingdom
- Correspondence and requests for materials should be addressed to A.F. () and B.W.H. ()
| | - Bart W. Hoogenboom
- London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London WC1H 0AH, United Kingdom
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
- Correspondence and requests for materials should be addressed to A.F. () and B.W.H. ()
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16
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Rosso G, Liashkovich I, Gess B, Young P, Kun A, Shahin V. Unravelling crucial biomechanical resilience of myelinated peripheral nerve fibres provided by the Schwann cell basal lamina and PMP22. Sci Rep 2014; 4:7286. [PMID: 25446378 PMCID: PMC4250911 DOI: 10.1038/srep07286] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 11/14/2014] [Indexed: 11/09/2022] Open
Abstract
There is an urgent need for the research of the close and enigmatic relationship between nerve biomechanics and the development of neuropathies. Here we present a research strategy based on the application atomic force and confocal microscopy for simultaneous nerve biomechanics and integrity investigations. Using wild-type and hereditary neuropathy mouse models, we reveal surprising mechanical protection of peripheral nerves. Myelinated peripheral wild-type fibres promptly and fully recover from acute enormous local mechanical compression while maintaining functional and structural integrity. The basal lamina which enwraps each myelinated fibre separately is identified as the major contributor to the striking fibre's resilience and integrity. In contrast, neuropathic fibres lacking the peripheral myelin protein 22 (PMP22), which is closely connected with several hereditary human neuropathies, fail to recover from light compression. Interestingly, the structural arrangement of the basal lamina of Pmp22−/− fibres is significantly altered compared to wild-type fibres. In conclusion, the basal lamina and PMP22 act in concert to contribute to a resilience and integrity of peripheral nerves at the single fibre level. Our findings and the presented technology set the stage for a comprehensive research of the links between nerve biomechanics and neuropathies.
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Affiliation(s)
- Gonzalo Rosso
- Institute of Physiology II, WWU Münster, Robert-Koch-Straße 27b 48149 Münster, Germany
| | - Ivan Liashkovich
- Institute of Physiology II, WWU Münster, Robert-Koch-Straße 27b 48149 Münster, Germany
| | - Burkhard Gess
- Department of Sleep Medicine and Neuromuscular Disorders, Albert-Schweitzer Campus 1, Geb. A1, 48149 Münster, Germany
| | - Peter Young
- Department of Sleep Medicine and Neuromuscular Disorders, Albert-Schweitzer Campus 1, Geb. A1, 48149 Münster, Germany
| | - Alejandra Kun
- Department of Proteins and Nucleic Acids, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - Victor Shahin
- Institute of Physiology II, WWU Münster, Robert-Koch-Straße 27b 48149 Münster, Germany
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17
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Meyring-Wösten A, Hafezi W, Kühn J, Liashkovich I, Shahin V. Nano-visualization of viral DNA breaching the nucleocytoplasmic barrier. J Control Release 2014; 173:96-101. [DOI: 10.1016/j.jconrel.2013.10.036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Revised: 10/23/2013] [Accepted: 10/29/2013] [Indexed: 12/13/2022]
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18
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Liashkovich I, Meyring A, Oberleithner H, Shahin V. Structural organization of the nuclear pore permeability barrier. J Control Release 2012; 160:601-8. [PMID: 22386519 DOI: 10.1016/j.jconrel.2012.02.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 02/13/2012] [Accepted: 02/17/2012] [Indexed: 12/26/2022]
Abstract
The efficiency of gene therapy in non-dividing cells is particularly poor due to restricted nuclear delivery rates of exogenously applied macromolecules across the nuclear pore complexes (NPCs). Therefore, improved intranuclear delivery of transgenes requires an ability to modulate the barrier function of the NPC. Despite a large body of experimental evidence accumulated to date, the contribution of individual NPC proteins (nucleoporins) to the formation of the NPC permeability barrier as well as their structural organization within the NPC remains under debate. In the present study, we revisit the view on the spatial arrangement of the Phe-Gly rich domains (FG-domains) of a subset of nucleoporins known as FG-nucleoporins. They are generally believed to be the key constituents of the NPC permeability barrier. Comparison of the binding pattern of a transport receptor importin β fragment, that binds specifically to FG-domains, with the binding pattern of wheat germ agglutinin that binds elsewhere in the NPC, reveals that FG-domains tend to cluster in the very center of the NPC. Furthermore, a controlled sequential release of the barrier-forming nucleoporins results in a gradual breakdown of the NPC permeability barrier. The breakdown is initiated by a dissociation of Nup62 from the NPC. This is accompanied by an increased passive diffusion of small molecules across the NPC. Subsequent dissociation of Nup98 and possibly other nucleoporins results in a collapse of the barrier for larger molecules. We therefore conclude that FG-nucleoporins do not contribute equally to the maintenance of the NPC permeability barrier exclusion limit. This implies that a controlled release of nucleoporins that contribute most to the formation and maintenance of the NPC barrier can facilitate access of therapeutic macromolecules into the nucleus.
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Affiliation(s)
- Ivan Liashkovich
- Institute of Physiology II, WWU Münster, Robert-Koch-Straße 27b, 48149 Münster, Germany.
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Abstract
Herpes simplex virus type 1 (HSV-1) is a widespread human pathogen infecting more than 80% of the population worldwide. Its replication involves an essential, poorly understood multistep process, referred to as uncoating. Uncoating steps are as follows: (1) The incoming capsid pinpoints the nuclear pore complex (NPC). (2) It opens up at the NPC and releases the highly pressurized viral genome. (3) The viral genome translocates through the NPC. In the present review, we highlight recent advances in this field and propose mechanisms underlying the individual steps of uncoating. We presume that the incoming HSV-1 capsid pinpoints the NPC by hydrophobic interactions and opens up upon binding to NPC proteins. Genome translocation is initially pressure-driven.
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Affiliation(s)
- Ivan Liashkovich
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, 48147 Münster, Germany
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20
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Callies C, Fels J, Liashkovich I, Kliche K, Jeggle P, Kusche-Vihrog K, Oberleithner H. Membrane potential depolarization decreases the stiffness of vascular endothelial cells. J Cell Sci 2011; 124:1936-42. [PMID: 21558418 DOI: 10.1242/jcs.084657] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The stiffness of vascular endothelial cells is crucial to mechanically withstand blood flow and, at the same time, to control deformation-dependent nitric oxide release. However, the regulation of mechanical stiffness is not yet understood. There is evidence that a possible regulator is the electrical plasma membrane potential difference. Using a novel technique that combines fluorescence-based membrane potential recordings with atomic force microscopy (AFM)-based stiffness measurements, the present study shows that membrane depolarization is associated with a decrease in the stiffness of endothelial cells. Three different depolarization protocols were applied, all of which led to a similar and significant decrease in cell stiffness, independently of changes in cell volume. Moreover, experiments using the actin-destabilizing agent cytochalasin D indicated that depolarization acts by affecting the cortical actin cytoskeleton. A model is proposed whereby a change of the electrical field across the plasma membrane is directly sensed by the submembranous actin network, regulating the actin polymerization:depolymerization ratio and thus cell stiffness. This depolarization-induced decrease in the stiffness of endothelial cells could play a role in flow-mediated nitric-oxide-dependent vasodilation.
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Affiliation(s)
- Chiara Callies
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, 48149 Münster, Germany.
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21
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Abstract
Nuclear pore complexes (NPCs) mediate all transport between the cytosol and the nucleus and therefore take centre stage in physiology. While transport through NPCs has been extensively investigated little is known about their structural and barley anything about their mechanical flexibility. Structural and mechanical flexibility of NPCs, however, are presumably of key importance. Like the cell and the cell nucleus, NPCs themselves are regularly exposed to physiological mechanical forces. Besides, NPCs reveal striking transport properties which are likely to require fairly high structural flexibility. The NPC transports up to 1,000 molecules per second through a physically 9 nm wide channel which repeatedly opens to accommodate macromolecules significantly larger than its physical diameter. We hypothesised that NPCs possess remarkable structural and mechanical stability. Here, we tested this hypothesis at the single NPC level using the nano-imaging and probing approach atomic force microscopy (AFM). AFM presents the NPC as a highly flexible structure. The NPC channel dilates by striking 35% on exposure to trans-cyclohexane-1,2-diol (TCHD), which is known to transiently collapse the hydrophobic phase in the NPC channel like receptor-cargo complexes do in transit. It constricts again to its initial size after TCHD removal. AFM-based nano-indentation measurements show that the 50 nm long NPC basket can astonishingly be squeezed completely into the NPC channel on exposure to incremental mechanical loads but recovers its original vertical position within the nuclear envelope plane when relieved. We conclude that the NPC possesses exceptional structural and mechanical flexibility which is important to fulfilling its functions.
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Affiliation(s)
- Ivan Liashkovich
- Institute of Physiology II, University of Münster, Münster, Germany
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22
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Kramer A, Liashkovich I, Oberleithner H, Shahin V. Caspase-9-dependent decrease of nuclear pore channel hydrophobicity is accompanied by nuclear envelope leakiness. Nanomedicine: Nanotechnology, Biology and Medicine 2010; 6:605-11. [DOI: 10.1016/j.nano.2010.04.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Revised: 04/15/2010] [Accepted: 04/27/2010] [Indexed: 12/24/2022]
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23
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Lamprecht C, Liashkovich I, Neves V, Danzberger J, Heister E, Rangl M, Coley HM, McFadden J, Flahaut E, Gruber HJ, Hinterdorfer P, Kienberger F, Ebner A. AFM imaging of functionalized carbon nanotubes on biological membranes. Nanotechnology 2009; 20:434001. [PMID: 19801758 DOI: 10.1088/0957-4484/20/43/434001] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Multifunctional carbon nanotubes are promising for biomedical applications as their nano-size, together with their physical stability, gives access into the cell and various cellular compartments including the nucleus. However, the direct and label-free detection of carbon nanotube uptake into cells is a challenging task. The atomic force microscope (AFM) is capable of resolving details of cellular surfaces at the nanometer scale and thus allows following of the docking of carbon nanotubes to biological membranes. Here we present topographical AFM images of non-covalently functionalized single walled (SWNT) and double walled carbon nanotubes (DWNT) immobilized on different biological membranes, such as plasma membranes and nuclear envelopes, as well as on a monolayer of avidin molecules. We were able to visualize DWNT on the nuclear membrane while at the same time resolving individual nuclear pore complexes. Furthermore, we succeeded in localizing individual SWNT at the border of incubated cells and in identifying bundles of DWNT on cell surfaces by AFM imaging.
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Affiliation(s)
- C Lamprecht
- Institute of Biophysics, J Kepler University, Linz, Austria
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24
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Rangl M, Nevo R, Liashkovich I, Shahin V, Reich Z, Ebner A, Hinterdorfer P. Inside Cover: Stable, Non-Destructive Immobilization of Native Nuclear Membranes to Micro-Structured PDMS for Single-Molecule Force Spectroscopy (ChemPhysChem 9-10/2009). Chemphyschem 2009. [DOI: 10.1002/cphc.200990035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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25
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Rangl M, Nevo R, Liashkovich I, Shahin V, Reich Z, Ebner A, Hinterdorfer P. Stable, non-destructive immobilization of native nuclear membranes to micro-structured PDMS for single-molecule force spectroscopy. Chemphyschem 2009; 10:1553-8. [PMID: 19507204 PMCID: PMC3013320 DOI: 10.1002/cphc.200900219] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2009] [Indexed: 11/08/2022]
Abstract
In eukaryotic cells the nucleus is separated from the cytoplasm by a double-membraned nuclear envelope (NE). Exchange of molecules between the two compartments is mediated by nuclear pore complexes (NPCs) that are embedded in the NE membranes. The translocation of molecules such as proteins and RNAs through the nuclear membrane is executed by transport shuttling factors (karyopherines). They thereby dock to particular binding sites located all over the NPC, the so-called phenylalanine-glycin nucleoporines (FG Nups). Molecular recognition force spectroscopy (MRFS) allows investigations of the binding at the single-molecule level. Therefore the AFM tip carries a ligand for example, a particular karyopherin whereas the nuclear membrane with its receptors is mounted on a surface. Hence, one of the first requirements to study the nucleocytoplasmatic transport mechanism using MRFS is the development of an optimized membrane preparation that preserves structure and function of the NPCs. In this study we present a stable non-destructive preparation method of Xenopus laevis nuclear envelopes. We use micro-structured polydimethylsiloxane (PDMS) that provides an ideal platform for immobilization and biological integrity due to its elastic, chemical and mechanical properties. It is a solid basis for studying molecular recognition, transport interactions, and translocation processes through the NPC. As a first recognition system we investigate the interaction between an important transport shuttling factor, importin beta, and its binding sites on the NPC, the FG-domains.
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Affiliation(s)
- Martina Rangl
- Institute for Biophysics, Johannes Kepler University of Linz, Altenbergerstr. 69, 4040 Linz (Austria)
| | - Reinat Nevo
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100 (Israel)
| | - Ivan Liashkovich
- Department of Physiology, University of Münster, Robert-Koch-str. 27b, 48149 Münster (Germany)
| | - Victor Shahin
- Department of Physiology, University of Münster, Robert-Koch-str. 27b, 48149 Münster (Germany)
| | - Ziv Reich
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100 (Israel)
| | - Andreas Ebner
- Institute for Biophysics, Johannes Kepler University of Linz, Altenbergerstr. 69, 4040 Linz (Austria)
| | - Peter Hinterdorfer
- Institute for Biophysics, Johannes Kepler University of Linz, Altenbergerstr. 69, 4040 Linz (Austria)
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Callies C, Schön P, Liashkovich I, Stock C, Kusche-Vihrog K, Fels J, Sträter AS, Oberleithner H. Simultaneous mechanical stiffness and electrical potential measurements of living vascular endothelial cells using combined atomic force and epifluorescence microscopy. Nanotechnology 2009; 20:175104. [PMID: 19420584 DOI: 10.1088/0957-4484/20/17/175104] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The degree of mechanical stiffness of vascular endothelial cells determines the endogenous production of the vasodilating gas nitric oxide (NO). However, the underlying mechanisms are not yet understood. Experiments on vascular endothelial cells suggest that the electrical plasma membrane potential is involved in this regulatory process. To test this hypothesis we developed a technique that simultaneously measures the electrical membrane potential and stiffness of vascular endothelial cells (GM7373 cell line derived from bovine aortic endothelium) under continuous perfusion with physiological electrolyte solution. The cellular stiffness was determined by nano-indentation using an atomic force microscope (AFM) while the electrical membrane potential was measured with bis-oxonol, a voltage-reporting fluorescent dye. These two methods were combined using an AFM attached to an epifluorescence microscope. The electrical membrane potential and mechanical stiffness of the same cell were continuously recorded for a time span of 5 min. Fast fluctuations (in the range of seconds) of both the electrical membrane potential and mechanical stiffness could be observed that were not related to each other. In contrast, slow cell depolarizations (in the range of minutes) were paralleled by significant increases in mechanical stiffness. In conclusion, using the combined AFM-fluorescence technique we monitored for the first time simultaneously the electrical plasma membrane potential and mechanical stiffness in a living cell. Vascular endothelial cells exhibit oscillatory non-synchronized waves of electrical potential and mechanical stiffness. The sustained membrane depolarization, however, is paralleled by a concomitant increase of cell stiffness. The described method is applicable for any fluorophore, which opens new perspectives in biomedical research.
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Affiliation(s)
- Chiara Callies
- Institute of Physiology II, University of Münster, Germany.
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Kramer A, Liashkovich I, Oberleithner H, Ludwig S, Mazur I, Shahin V. Apoptosis leads to a degradation of vital components of active nuclear transport and a dissociation of the nuclear lamina. Proc Natl Acad Sci U S A 2008; 105:11236-41. [PMID: 18678902 PMCID: PMC2516273 DOI: 10.1073/pnas.0801967105] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2008] [Indexed: 02/05/2023] Open
Abstract
Apoptosis, a physiologically critical process, is characterized by a destruction of the cell after sequential degradation of key cellular components. Here, we set out to explore the fate of the physiologically indispensable nuclear envelope (NE) in this process. The NE mediates the critical nucleocytoplasmic transport through nuclear pore complexes (NPCs). In addition, the NE is involved in gene expression and contributes significantly to the overall structure and mechanical stability of the cell nucleus through the nuclear lamina, which underlies the entire nucleoplasmic face of the NE and thereby interconnects the NPCs, the NE, and the genomic material. Using the nano-imaging and mechanical probing approach atomic force microscopy (AFM) and biochemical methods, we unveiled the fate of the NE during apoptosis. The doomed NE sustains a degradation of both the mediators of the critical selective nucleocytoplasmic transport, namely NPC cytoplasmic filaments and basket, and the nuclear lamina. These observations are paralleled by marked softening and destabilization of the NE and the detection of vesicle-like nuclear fragments. We conclude that destruction of the cell nucleus during apoptosis proceeds in a strategic fashion. Degradation of NPC cytoplasmic filaments and basket shuts down the critical selective nucleocytoplasmic cross-talk. Degradation of the nuclear lamina disrupts the pivotal connection between the NE and the chromatin, breaks up the overall nuclear architecture, and softens the NE, thereby enabling the formation of nuclear fragments at later stages of apoptosis.
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Affiliation(s)
- A. Kramer
- *Institute of Physiology II, Westfälische Wilhelms-Universität Münster, Robert-Koch-Strasse 27b, 48149 Münster, Germany; and
| | - I. Liashkovich
- *Institute of Physiology II, Westfälische Wilhelms-Universität Münster, Robert-Koch-Strasse 27b, 48149 Münster, Germany; and
| | - H. Oberleithner
- *Institute of Physiology II, Westfälische Wilhelms-Universität Münster, Robert-Koch-Strasse 27b, 48149 Münster, Germany; and
| | - S. Ludwig
- Molecular Virology, Zentrums für Molekularbiologie der Entzündung, Westfälische Wilhelms-Universität Münster, Von-Esmach-Strasse 56, 48149 Münster, Germany
| | - I. Mazur
- Molecular Virology, Zentrums für Molekularbiologie der Entzündung, Westfälische Wilhelms-Universität Münster, Von-Esmach-Strasse 56, 48149 Münster, Germany
| | - V. Shahin
- *Institute of Physiology II, Westfälische Wilhelms-Universität Münster, Robert-Koch-Strasse 27b, 48149 Münster, Germany; and
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Liashkovich I, Hafezi W, Kühn JE, Oberleithner H, Kramer A, Shahin V. Exceptional mechanical and structural stability of HSV-1 unveiled with fluid atomic force microscopy. J Cell Sci 2008; 121:2287-92. [DOI: 10.1242/jcs.032284] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Evidence is emerging that changes in the structural and mechanical properties of viral particles are closely linked and that such changes are essential to infectivity. Here, applying the nanostructural and nanomechanical approach of atomic force microscopy, we visualised capsids of the ubiquitous human pathogen herpes simplex virus type 1 (HSV-1) at nano-scale resolution in physiologically relevant conditions. Simultaneously performed nano-indentation measurements on genome-containing and genome-free capsids revealed that genome-containing HSV-1 capsids withstand an exceptionally large mechanical force of ∼6 nN, which is three times larger than the highest values previously reported for other viruses. Greater mechanical forces, however, led to a release of the viral genome. The resulting genome-free capsids, which largely retained their overall structure, were found to be utterly elastic. HSV-1 capsids thus exhibit an exceptional structural and mechanical stability, which is largely provided by the densely packaged genome. This stability might be the key determinant for capsid survival over long distances in the axonal cytoplasm where it is exposed to mechanical forces by molecular motors before it reaches the nuclear pore for crucial genome uncoating.
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Affiliation(s)
- Ivan Liashkovich
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, 48149 Münster, Germany
| | - Wali Hafezi
- Institute of Medical Microbiology, University of Münster, Domagkstr. 10, 48149 Münster, Germany
- Interdisciplinary Center of Clinical Research (IZKF), University of Münster, Domagkstr. 3, 48149 Münster, Germany
| | - Joachim E. Kühn
- Institute of Medical Microbiology, University of Münster, Domagkstr. 10, 48149 Münster, Germany
- Interdisciplinary Center of Clinical Research (IZKF), University of Münster, Domagkstr. 3, 48149 Münster, Germany
| | - Hans Oberleithner
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, 48149 Münster, Germany
| | - Armin Kramer
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, 48149 Münster, Germany
| | - Victor Shahin
- Institute of Physiology II, University of Münster, Robert-Koch-Str. 27b, 48149 Münster, Germany
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