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Vámos A, Arianti R, Vinnai BÁ, Alrifai R, Shaw A, Póliska S, Guba A, Csősz É, Csomós I, Mocsár G, Lányi C, Balajthy Z, Fésüs L, Kristóf E. Corrigendum: Human abdominal subcutaneous-derived active beige adipocytes carrying FTO rs1421085 obesity-risk alleles exert lower thermogenic capacity. Front Cell Dev Biol 2023; 11:1249909. [PMID: 37711854 PMCID: PMC10499436 DOI: 10.3389/fcell.2023.1249909] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 07/04/2023] [Indexed: 09/16/2023] Open
Abstract
[This corrects the article DOI: 10.3389/fcell.2023.1155673.].
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Affiliation(s)
- Attila Vámos
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Doctoral School of Molecular Cell and Immune Biology, University of Debrecen, Debrecen, Hungary
| | - Rini Arianti
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Universitas Muhammadiyah Bangka Belitung, Pangkalanbaru, Indonesia
| | - Boglárka Ágnes Vinnai
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Doctoral School of Molecular Cell and Immune Biology, University of Debrecen, Debrecen, Hungary
| | - Rahaf Alrifai
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Doctoral School of Molecular Cell and Immune Biology, University of Debrecen, Debrecen, Hungary
| | - Abhirup Shaw
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Szilárd Póliska
- Genomic Medicine and Bioinformatics Core Facility, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Andrea Guba
- Doctoral School of Molecular Cell and Immune Biology, University of Debrecen, Debrecen, Hungary
- Proteomics Core Facility, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Éva Csősz
- Proteomics Core Facility, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - István Csomós
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Gábor Mocsár
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | | | - Zoltán Balajthy
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - László Fésüs
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Endre Kristóf
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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2
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Vámos A, Arianti R, Vinnai BÁ, Alrifai R, Shaw A, Póliska S, Guba A, Csősz É, Csomós I, Mocsár G, Lányi C, Balajthy Z, Fésüs L, Kristóf E. Human abdominal subcutaneous-derived active beige adipocytes carrying FTO rs1421085 obesity-risk alleles exert lower thermogenic capacity. Front Cell Dev Biol 2023; 11:1155673. [PMID: 37416800 PMCID: PMC10321670 DOI: 10.3389/fcell.2023.1155673] [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] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 05/26/2023] [Indexed: 07/08/2023] Open
Abstract
Introduction: White adipocytes store lipids, have a large lipid droplet and few mitochondria. Brown and beige adipocytes, which produce heat, are characterized by high expression of uncoupling protein (UCP) 1, multilocular lipid droplets, and large amounts of mitochondria. The rs1421085 T-to-C single-nucleotide polymorphism (SNP) of the human FTO gene interrupts a conserved motif for ARID5B repressor, resulting in adipocyte type shift from beige to white. Methods: We obtained abdominal subcutaneous adipose tissue from donors carrying FTO rs1421085 TT (risk-free) or CC (obesity-risk) genotypes, isolated and differentiated their preadipocytes into beige adipocytes (driven by the PPARγ agonist rosiglitazone for 14 days), and activated them with dibutyryl-cAMP for 4 hours. Then, either the same culture conditions were applied for additional 14 days (active beige adipocytes) or it was replaced by a white differentiation medium (inactive beige adipocytes). White adipocytes were differentiated by their medium for 28 days. Results and Discussion: RNA-sequencing was performed to investigate the gene expression pattern of adipocytes carrying different FTO alleles and found that active beige adipocytes had higher brown adipocyte content and browning capacity compared to white or inactive beige ones when the cells were obtained from risk-free TT but not from obesity-risk CC genotype carriers. Active beige adipocytes carrying FTO CC had lower thermogenic gene (e.g., UCP1, PM20D1, CIDEA) expression and thermogenesis measured by proton leak respiration as compared to TT carriers. In addition, active beige adipocytes with CC alleles exerted lower expression of ASC-1 neutral amino acid transporter (encoded by SLC7A10) and less consumption of Ala, Ser, Cys, and Gly as compared to risk-free carriers. We did not observe any influence of the FTO rs1421085 SNP on white and inactive beige adipocytes highlighting its exclusive and critical effect when adipocytes were activated for thermogenesis.
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Affiliation(s)
- Attila Vámos
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Doctoral School of Molecular Cell and Immune Biology, University of Debrecen, Debrecen, Hungary
| | - Rini Arianti
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Universitas Muhammadiyah Bangka Belitung, Pangkalanbaru, Indonesia
| | - Boglárka Ágnes Vinnai
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Doctoral School of Molecular Cell and Immune Biology, University of Debrecen, Debrecen, Hungary
| | - Rahaf Alrifai
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Doctoral School of Molecular Cell and Immune Biology, University of Debrecen, Debrecen, Hungary
| | - Abhirup Shaw
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Szilárd Póliska
- Genomic Medicine and Bioinformatics Core Facility, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Andrea Guba
- Doctoral School of Molecular Cell and Immune Biology, University of Debrecen, Debrecen, Hungary
- Proteomics Core Facility, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Éva Csősz
- Proteomics Core Facility, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - István Csomós
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Gábor Mocsár
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | | | - Zoltán Balajthy
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - László Fésüs
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Endre Kristóf
- Laboratory of Cell Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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Gyöngy Z, Mocsár G, Hegedűs É, Stockner T, Ritter Z, Homolya L, Schamberger A, Orbán TI, Remenyik J, Szakacs G, Goda K. Nucleotide binding is the critical regulator of ABCG2 conformational transitions. eLife 2023; 12:83976. [PMID: 36763413 PMCID: PMC9917445 DOI: 10.7554/elife.83976] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 01/27/2023] [Indexed: 02/11/2023] Open
Abstract
ABCG2 is an exporter-type ABC protein that can expel numerous chemically unrelated xeno- and endobiotics from cells. When expressed in tumor cells or tumor stem cells, ABCG2 confers multidrug resistance, contributing to the failure of chemotherapy. Molecular details orchestrating substrate translocation and ATP hydrolysis remain elusive. Here, we present methods to concomitantly investigate substrate and nucleotide binding by ABCG2 in cells. Using the conformation-sensitive antibody 5D3, we show that the switch from the inward-facing (IF) to the outward-facing (OF) conformation of ABCG2 is induced by nucleotide binding. IF-OF transition is facilitated by substrates, and hindered by the inhibitor Ko143. Direct measurements of 5D3 and substrate binding to ABCG2 indicate that the high-to-low affinity switch of the drug binding site coincides with the transition from the IF to the OF conformation. Low substrate binding persists in the post-hydrolysis state, supporting that dissociation of the ATP hydrolysis products is required to reset the high substrate affinity IF conformation of ABCG2.
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Affiliation(s)
- Zsuzsanna Gyöngy
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of DebrecenDebrecenHungary,Doctoral School of Molecular Cell and Immune Biology, University of DebrecenDebrecenHungary
| | - Gábor Mocsár
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of DebrecenDebrecenHungary
| | - Éva Hegedűs
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of DebrecenDebrecenHungary
| | - Thomas Stockner
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of ViennaViennaAustria
| | - Zsuzsanna Ritter
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of DebrecenDebrecenHungary,Doctoral School of Molecular Cell and Immune Biology, University of DebrecenDebrecenHungary
| | - László Homolya
- Institute of Enzymology, Research Centre for Natural SciencesBudapestHungary
| | - Anita Schamberger
- Institute of Enzymology, Research Centre for Natural SciencesBudapestHungary
| | - Tamás I Orbán
- Institute of Enzymology, Research Centre for Natural SciencesBudapestHungary
| | - Judit Remenyik
- Institute of Food Technology, Faculty of Agricultural and Food Sciences and Environmental Management, University of DebrecenDebrecenHungary
| | - Gergely Szakacs
- Institute of Enzymology, Research Centre for Natural SciencesBudapestHungary,Institute of Cancer Research, Medical University of ViennaViennaAustria
| | - Katalin Goda
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of DebrecenDebrecenHungary
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Wai DCC, Naseem MU, Mocsár G, Babu Reddiar S, Pan Y, Csoti A, Hajdu P, Nowell C, Nicolazzo JA, Panyi G, Norton RS. Fluorescent Peptide Toxin for Selective Visualization of the Voltage-Gated Potassium Channel K V1.3. Bioconjug Chem 2022; 33:2197-2212. [DOI: 10.1021/acs.bioconjchem.2c00436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Dorothy C. C. Wai
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria3052, Australia
| | - Muhammad Umair Naseem
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen4032, Hungary
| | - Gábor Mocsár
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen4032, Hungary
- Damjanovich Cell Analysis Core Facility, Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen4032, Hungary
| | - Sanjeevini Babu Reddiar
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria3052, Australia
| | - Yijun Pan
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria3052, Australia
| | - Agota Csoti
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen4032, Hungary
| | - Peter Hajdu
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen4032, Hungary
- Department of Dental Biochemistry, Faculty of Dentistry, University of Debrecen, Debrecen4032, Hungary
| | - Cameron Nowell
- Imaging, FACS and Analysis Core, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria3052, Australia
| | - Joseph A. Nicolazzo
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria3052, Australia
| | - Gyorgy Panyi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen4032, Hungary
| | - Raymond S. Norton
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria3052, Australia
- ARC Centre for Fragment-Based Design, Monash University, Parkville, Victoria3052, Australia
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5
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Bosire R, Fadel L, Mocsár G, Nánási P, Sen P, Sharma AK, Naseem MU, Kovács A, Kugel J, Kroemer G, Vámosi G, Szabó G. Doxorubicin impacts chromatin binding of HMGB1, Histone H1 and retinoic acid receptor. Sci Rep 2022; 12:8087. [PMID: 35577872 PMCID: PMC9110345 DOI: 10.1038/s41598-022-11994-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 12/25/2021] [Accepted: 05/03/2022] [Indexed: 11/10/2022] Open
Abstract
Doxorubicin (Dox), a widely used anticancer DNA-binding drug, affects chromatin in multiple ways, and these effects contribute to both its efficacy and its dose-limiting side effects, especially cardiotoxicity. Here, we studied the effects of Dox on the chromatin binding of the architectural proteins high mobility group B1 (HMGB1) and the linker histone H1, and the transcription factor retinoic acid receptor (RARα) by fluorescence recovery after photobleaching (FRAP) and fluorescence correlation spectroscopy (FCS) in live cells. At lower doses, Dox increased the binding of HMGB1 to DNA while decreasing the binding of the linker histone H1. At higher doses that correspond to the peak plasma concentrations achieved during chemotherapy, Dox reduced the binding of HMGB1 as well. This biphasic effect is interpreted in terms of a hierarchy of competition between the ligands involved and Dox-induced local conformational changes of nucleosome-free DNA. Combined, FRAP and FCS mobility data suggest that Dox decreases the overall binding of RARα to DNA, an effect that was only partially overcome by agonist binding. The intertwined interactions described are likely to contribute to both the effects and side effects of Dox.
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Affiliation(s)
- Rosevalentine Bosire
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,Doctoral School of Molecular Cell and Immune Biology, University of Debrecen, Debrecen, Hungary
| | - Lina Fadel
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,Doctoral School of Molecular Medicine, University of Debrecen, Debrecen, Hungary
| | - Gábor Mocsár
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Péter Nánási
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Pialy Sen
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,Doctoral School of Molecular Medicine, University of Debrecen, Debrecen, Hungary
| | - Anshu Kumar Sharma
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Muhammad Umair Naseem
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,Doctoral School of Molecular Medicine, University of Debrecen, Debrecen, Hungary
| | - Attila Kovács
- Department of Radiation Therapy, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Jennifer Kugel
- Department of Biochemistry, University of Colorado, Boulder, USA
| | - Guido Kroemer
- Centre de Recherche Des Cordeliers, Equipe Labellisée Par La Ligue Contre Le Cancer, Université de Paris, Sorbonne Université, Inserm U1138, Institut Universitaire de France, Paris, France.,Metabolomics and Cell Biology Platforms, Institut Gustave Roussy, Villejuif, France.,Pôle de Biologie, Hôpital Européen Georges Pompidou, AP-HP, Paris, France
| | - György Vámosi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
| | - Gábor Szabó
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
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6
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Sebestyén V, Nagy É, Mocsár G, Volkó J, Szilágyi O, Kenesei Á, Panyi G, Tóth K, Hajdu P, Vámosi G. Role of C-Terminal Domain and Membrane Potential in the Mobility of Kv1.3 Channels in Immune Synapse Forming T Cells. Int J Mol Sci 2022; 23:ijms23063313. [PMID: 35328733 PMCID: PMC8952507 DOI: 10.3390/ijms23063313] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 03/15/2022] [Accepted: 03/16/2022] [Indexed: 02/01/2023] Open
Abstract
Voltage-gated Kv1.3 potassium channels are essential for maintaining negative membrane potential during T-cell activation. They interact with membrane-associated guanylate kinases (MAGUK-s) via their C-terminus and with TCR/CD3, leading to enrichment at the immunological synapse (IS). Molecular interactions and mobility may impact each other and the function of these proteins. We aimed to identify molecular determinants of Kv1.3 mobility, applying fluorescence correlation spectroscopy on human Jurkat T-cells expressing WT, C-terminally truncated (ΔC), and non-conducting mutants of mGFP-Kv1.3. ΔC cannot interact with MAGUK-s and is not enriched at the IS, whereas cells expressing the non-conducting mutant are depolarized. Here, we found that in standalone cells, mobility of ΔC increased relative to the WT, likely due to abrogation of interactions, whereas mobility of the non-conducting mutant decreased, similar to our previous observations on other membrane proteins in depolarized cells. At the IS formed with Raji B-cells, mobility of WT and non-conducting channels, unlike ΔC, was lower than outside the IS. The Kv1.3 variants possessing an intact C-terminus had lower mobility in standalone cells than in IS-engaged cells. This may be related to the observed segregation of F-actin into a ring-like structure at the periphery of the IS, leaving much of the cell almost void of F-actin. Upon depolarizing treatment, mobility of WT and ΔC channels decreased both in standalone and IS-engaged cells, contrary to non-conducting channels, which themselves caused depolarization. Our results support that Kv1.3 is enriched at the IS via its C-terminal region regardless of conductivity, and that depolarization decreases channel mobility.
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Affiliation(s)
- Veronika Sebestyén
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (V.S.); (É.N.); (G.M.); (J.V.); (O.S.); (Á.K.); (G.P.); (K.T.)
| | - Éva Nagy
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (V.S.); (É.N.); (G.M.); (J.V.); (O.S.); (Á.K.); (G.P.); (K.T.)
| | - Gábor Mocsár
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (V.S.); (É.N.); (G.M.); (J.V.); (O.S.); (Á.K.); (G.P.); (K.T.)
| | - Julianna Volkó
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (V.S.); (É.N.); (G.M.); (J.V.); (O.S.); (Á.K.); (G.P.); (K.T.)
| | - Orsolya Szilágyi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (V.S.); (É.N.); (G.M.); (J.V.); (O.S.); (Á.K.); (G.P.); (K.T.)
| | - Ádám Kenesei
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (V.S.); (É.N.); (G.M.); (J.V.); (O.S.); (Á.K.); (G.P.); (K.T.)
| | - György Panyi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (V.S.); (É.N.); (G.M.); (J.V.); (O.S.); (Á.K.); (G.P.); (K.T.)
| | - Katalin Tóth
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (V.S.); (É.N.); (G.M.); (J.V.); (O.S.); (Á.K.); (G.P.); (K.T.)
- Division Biophysics of Macromolecules, German Cancer Research Center, D-69120 Heidelberg, Germany
| | - Péter Hajdu
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (V.S.); (É.N.); (G.M.); (J.V.); (O.S.); (Á.K.); (G.P.); (K.T.)
- Department of Biophysics and Cell Biology, Faculty of Dentistry, University of Debrecen, H-4032 Debrecen, Hungary
- Correspondence: (P.H.); (G.V.)
| | - György Vámosi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; (V.S.); (É.N.); (G.M.); (J.V.); (O.S.); (Á.K.); (G.P.); (K.T.)
- Correspondence: (P.H.); (G.V.)
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7
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Kenesei Á, Volkó J, Szalóki N, Mocsár G, Jambrovics K, Balajthy Z, Bodnár A, Tóth K, Waldmann TA, Vámosi G. IL-15 Trans-Presentation Is an Autonomous, Antigen-Independent Process. J Immunol 2021; 207:2489-2500. [PMID: 34654688 DOI: 10.4049/jimmunol.2100277] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 09/10/2021] [Indexed: 11/19/2022]
Abstract
IL-15 plays a pivotal role in the long-term survival of T cells and immunological memory. Its receptor consists of three subunits (IL-15Rα, IL-2/15Rβ, and γc). IL-15 functions mainly via trans-presentation (TP), during which an APC expressing IL-15 bound to IL-15Rα presents the ligand to the βγc receptor-heterodimer on a neighboring T/NK cell. To date, no direct biophysical evidence for the intercellular assembly of the IL-15R heterotrimer exists. Ag presentation (AP), the initial step of T cell activation, is also based on APC-T cell interaction. We were compelled to ask whether AP has any effect on IL-15 TP or whether they are independent processes. In our human Raji B cell-Jurkat T cell model system, we monitored inter-/intracellular protein interactions upon formation of IL-15 TP and AP receptor complexes by Förster resonance energy transfer measurements. We detected enrichment of IL-15Rα and IL-2/15Rβ at the synapse and positive Förster resonance energy transfer efficiency if Raji cells were pretreated with IL-15, giving direct biophysical evidence for IL-15 TP. IL-15Rα and MHC class II interacted and translocated jointly to the immunological synapse when either ligand was present, whereas IL-2/15Rβ and CD3 moved independently of each other. IL-15 TP initiated STAT5 phosphorylation in Jurkat cells, which was not further enhanced by AP. Conversely, IL-15 treatment slightly attenuated Ag-induced phosphorylation of the CD3ζ chain. Our studies prove that in our model system, IL-15 TP and AP can occur independently, and although AP enhances IL-15R assembly, it has no significant effect on IL-15 signaling during TP. Thus, IL-15 TP can be considered an autonomous, Ag-independent process.
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Affiliation(s)
- Ádám Kenesei
- Department of Biophysics and Cell Biology, Doctoral School of Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Julianna Volkó
- Department of Biophysics and Cell Biology, Doctoral School of Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Nikoletta Szalóki
- Department of Biophysics and Cell Biology, Doctoral School of Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Gábor Mocsár
- Department of Biophysics and Cell Biology, Doctoral School of Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Károly Jambrovics
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Zoltán Balajthy
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Andrea Bodnár
- Department of Biophysics and Cell Biology, Doctoral School of Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Katalin Tóth
- Division of Biophysics of Macromolecules, German Cancer Research Center, Heidelberg, Germany; and
| | - Thomas A Waldmann
- Lymphoid Malignancies Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD
| | - György Vámosi
- Department of Biophysics and Cell Biology, Doctoral School of Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary;
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8
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Nánási P, Imre L, Firouzi Niaki E, Bosire R, Mocsár G, Türk-Mázló A, Ausio J, Szabó G. Doxorubicin induces large-scale and differential H2A and H2B redistribution in live cells. PLoS One 2020; 15:e0231223. [PMID: 32298286 PMCID: PMC7162453 DOI: 10.1371/journal.pone.0231223] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 03/18/2020] [Indexed: 01/10/2023] Open
Abstract
We observed prominent effects of doxorubicin (Dox), an anthracycline widely used in anti-cancer therapy, on the aggregation and intracellular distribution of both partners of the H2A-H2B dimer, with marked differences between the two histones. Histone aggregation, assessed by Laser Scanning Cytometry via the retention of the aggregates in isolated nuclei, was observed in the case of H2A. The dominant effect of the anthracycline on H2B was its massive accumulation in the cytoplasm of the Jurkat leukemia cells concomitant with its disappearance from the nuclei, detected by confocal microscopy and mass spectrometry. A similar effect of the anthracycline was observed in primary human lymphoid cells, and also in monocyte-derived dendritic cells that harbor an unusually high amount of H2B in their cytoplasm even in the absence of Dox treatment. The nucleo-cytoplasmic translocation of H2B was not affected by inhibitors of major biochemical pathways or the nuclear export inhibitor leptomycin B, but it was completely diminished by PYR-41, an inhibitor with pleiotropic effects on protein degradation pathways. Dox and PYR-41 acted synergistically according to isobologram analyses of cytotoxicity. These large-scale effects were detected already at Dox concentrations that may be reached in the typical clinical settings, therefore they can contribute both to the anti-cancer mechanism and to the side-effects of this anthracycline.
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Affiliation(s)
- Péter Nánási
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Doctoral School of Molecular Cell and Immune Biology, Debrecen, Hungary
| | - László Imre
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Doctoral School of Molecular Cell and Immune Biology, Debrecen, Hungary
| | - Erfaneh Firouzi Niaki
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Doctoral School of Molecular Cell and Immune Biology, Debrecen, Hungary
| | - Rosevalentine Bosire
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Doctoral School of Molecular Cell and Immune Biology, Debrecen, Hungary
| | - Gábor Mocsár
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Doctoral School of Molecular Cell and Immune Biology, Debrecen, Hungary
| | - Anett Türk-Mázló
- Department of Immunology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Juan Ausio
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Gábor Szabó
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Doctoral School of Molecular Cell and Immune Biology, Debrecen, Hungary
- * E-mail:
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9
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Rehó B, Lau L, Mocsár G, Müller G, Fadel L, Brázda P, Nagy L, Tóth K, Vámosi G. Simultaneous Mapping of Molecular Proximity and Comobility Reveals Agonist-Enhanced Dimerization and DNA Binding of Nuclear Receptors. Anal Chem 2020; 92:2207-2215. [PMID: 31870146 DOI: 10.1021/acs.analchem.9b04902] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Single Plane Illumination Microscopy (SPIM) revolutionized time lapse imaging of live cells and organisms due to its high speed and reduced photodamage. Quantitative mapping of molecular (co)mobility by fluorescence (cross-)correlation spectroscopy (F(C)CS) in a SPIM has been introduced to reveal molecular diffusion and binding. A complementary aspect of interactions is proximity, which can be studied by Förster resonance energy transfer (FRET). Here, we extend SPIM-FCCS by alternating laser excitation, which reduces false positive cross-correlation and facilitates comapping of FRET. Thus, different aspects of interacting systems can be studied simultaneously, and molecular subpopulations can be discriminated by multiparameter analysis. After demonstrating the benefits of the method on the AP-1 transcription factor, the dimerization and DNA binding behavior of retinoic acid receptor (RAR) and retinoid X receptor (RXR) is revealed, and an extension of the molecular switch model of the nuclear receptor action is proposed. Our data imply that RAR agonist enhances RAR-RXR heterodimerization, and chromatin binding/dimerization are positively correlated. We also propose a ligand induced conformational change bringing the N-termini of RAR and RXR closer together. The RXR agonist increased homodimerization of RXR suggesting that RXR may act as an autonomous transcription factor.
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Affiliation(s)
- Bálint Rehó
- Department of Biophysics and Cell Biology, Doctoral School of Molecular Medicine, Faculty of Medicine , University of Debrecen , Egyetem tér 1 , H-4032 Debrecen , Hungary
| | - Lukas Lau
- Division Biophysics of Macromolecules , German Cancer Research Center , Im Neuenheimer Feld 280 , D-69120 Heidelberg , Germany
| | - Gábor Mocsár
- Department of Biophysics and Cell Biology, Doctoral School of Molecular Medicine, Faculty of Medicine , University of Debrecen , Egyetem tér 1 , H-4032 Debrecen , Hungary
| | - Gabriele Müller
- Division Biophysics of Macromolecules , German Cancer Research Center , Im Neuenheimer Feld 280 , D-69120 Heidelberg , Germany
| | - Lina Fadel
- Department of Biophysics and Cell Biology, Doctoral School of Molecular Medicine, Faculty of Medicine , University of Debrecen , Egyetem tér 1 , H-4032 Debrecen , Hungary
| | - Péter Brázda
- Department of Biochemistry and Molecular Biology, Faculty of Medicine , University of Debrecen , Egyetem tér 1 , H-4032 Debrecen , Hungary
| | - László Nagy
- Department of Biochemistry and Molecular Biology, Faculty of Medicine , University of Debrecen , Egyetem tér 1 , H-4032 Debrecen , Hungary.,Johns Hopkins University School of Medicine , Department of Medicine and Biological Chemistry, Institute for Fundamental Biomedical Research, Johns Hopkins All Children's Hospital , 600 Fifth Street South Saint Petersburg , Florida 33701-4634 , United States
| | - Katalin Tóth
- Division Biophysics of Macromolecules , German Cancer Research Center , Im Neuenheimer Feld 280 , D-69120 Heidelberg , Germany
| | - György Vámosi
- Department of Biophysics and Cell Biology, Doctoral School of Molecular Medicine, Faculty of Medicine , University of Debrecen , Egyetem tér 1 , H-4032 Debrecen , Hungary
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10
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Nizsalóczki E, Nagy P, Mocsár G, Szabó Á, Csomós I, Waldmann TA, Vámosi G, Mátyus L, Bodnár A. Minimum degree of overlap between IL-9R and IL-2R on human T lymphoma cells: A quantitative CLSM and FRET analysis. Cytometry A 2018; 93:1106-1117. [PMID: 30378727 PMCID: PMC8108070 DOI: 10.1002/cyto.a.23634] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [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: 04/13/2018] [Revised: 07/30/2018] [Accepted: 09/18/2018] [Indexed: 01/15/2023]
Abstract
The heterodimeric receptor complex of IL-9 consists of the cytokine-specific α-subunit and the common γc -chain shared with other cytokines, including IL-2, a central regulator of T cell function. We have shown previously the bipartite spatial relationship of IL-9 and IL-2 receptors at the surface of human T lymphoma cells: in addition to common clusters, expression of the two receptor kinds could also be observed in segregated membrane areas. Here we analyzed further the mutual cell surface organization of IL-9 and IL-2 receptors. Complementing Pearson correlation data with co-occurrence analysis of confocal microscopic images revealed that a minimum degree of IL-9R/IL-2R co-localization exists at the cell surface regardless of the overall spatial correlation of the two receptor kinds. Moreover, our FRET experiments demonstrated molecular scale assemblies of the elements of the IL-9/IL-2R system. Binding of IL-9 altered the structure and/or composition of these clusters. It is hypothesized, that by sequestering receptor subunits in common membrane areas, the overlapping domains of IL-9R and IL-2R provide a platform enabling both the formation of the appropriate receptor complex as well as subunit sharing between related cytokines. © 2018 International Society for Advancement of Cytometry.
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Affiliation(s)
- Enikő Nizsalóczki
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Péter Nagy
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Gábor Mocsár
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Ágnes Szabó
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - István Csomós
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Thomas A. Waldmann
- Lymphoid Malignancies Branch, National Institutes of Health, Bethesda, Maryland
| | - György Vámosi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - László Mátyus
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Andrea Bodnár
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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11
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Nagy É, Mocsár G, Sebestyén V, Volkó J, Papp F, Tóth K, Damjanovich S, Panyi G, Waldmann TA, Bodnár A, Vámosi G. Membrane Potential Distinctly Modulates Mobility and Signaling of IL-2 and IL-15 Receptors in T Cells. Biophys J 2018; 114:2473-2482. [PMID: 29754714 PMCID: PMC6129476 DOI: 10.1016/j.bpj.2018.04.038] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [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: 03/07/2018] [Revised: 04/21/2018] [Accepted: 04/23/2018] [Indexed: 12/11/2022] Open
Abstract
The high electric field across the plasma membrane might influence the conformation and behavior of transmembrane proteins that have uneven charge distributions in or near their transmembrane regions. Membrane depolarization of T cells occurs in the tumor microenvironment and in inflamed tissues because of K+ release from necrotic cells and hypoxia affecting the expression of K+ channels. However, little attention has been given to the effect of membrane potential (MP) changes on membrane receptor function. Therefore, we studied the influence of membrane de- and hyperpolarization on the biophysical properties and signaling of interleukin-2 (IL-2) and interleukin-15 (IL-15) receptors, which play important roles in T cell function. We investigated the mobility, clustering, and signaling of these receptors and major histocompatibility complex (MHC) I/II glycoproteins forming coclusters in lipid rafts of T cells. Depolarization by high K+ buffer or K+ channel blockers resulted in a decrease in the mobility of IL-2Rα and MHC glycoproteins, as shown by fluorescence correlation spectroscopy, whereas hyperpolarization by the K+ ionophore valinomycin increased their mobility. Contrary to this, the mobility of IL-15Rα decreased upon both de- and hyperpolarization. These changes in protein mobility are not due to an alteration of membrane fluidity, as evidenced by fluorescence anisotropy measurements. Förster resonance energy transfer measurements showed that most homo- or heteroassociations of IL-2R, IL-15R, and MHC I did not change considerably, either. MP changes modulated signaling by the two cytokines in distinct ways: depolarization caused a significant increase in the IL-2-induced phosphorylation of signal transducer and activator of transcription 5, whereas hyperpolarization evoked a decrease only in the IL-15-induced signal. Our data imply that the MP may be an important modulator of interleukin receptor signaling and dynamics. Enhanced IL-2 signaling in depolarized Treg cells highly expressing IL-2R may contribute to suppression of antitumor immune surveillance.
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Affiliation(s)
- Éva Nagy
- Department of Biophysics and Cell Biology, Faculty of Medicine
| | - Gábor Mocsár
- Department of Biophysics and Cell Biology, Faculty of Medicine
| | | | - Julianna Volkó
- Department of Biophysics and Cell Biology, Faculty of Medicine
| | - Ferenc Papp
- Department of Biophysics and Cell Biology, Faculty of Medicine; MTA-DE- NAP B Ion Channel Structure-Function Research Group, RCMM, University of Debrecen, Debrecen, Hungary
| | - Katalin Tóth
- Division Biophysics of Macromolecules, German Cancer Research Center, Heidelberg, Germany
| | | | - György Panyi
- Department of Biophysics and Cell Biology, Faculty of Medicine; MTA-DE- NAP B Ion Channel Structure-Function Research Group, RCMM, University of Debrecen, Debrecen, Hungary
| | - Thomas A Waldmann
- Lymphoid Malignancies Branch, National Institutes of Health, Bethesda, Maryland
| | - Andrea Bodnár
- Department of Biophysics and Cell Biology, Faculty of Medicine
| | - György Vámosi
- Department of Biophysics and Cell Biology, Faculty of Medicine.
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12
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Mocsár G, Volkó J, Rönnlund D, Widengren J, Nagy P, Szöllősi J, Tóth K, Goldman CK, Damjanovich S, Waldmann TA, Bodnár A, Vámosi G. MHC I Expression Regulates Co-clustering and Mobility of Interleukin-2 and -15 Receptors in T Cells. Biophys J 2017; 111:100-12. [PMID: 27410738 DOI: 10.1016/j.bpj.2016.05.044] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 05/09/2016] [Accepted: 05/16/2016] [Indexed: 11/28/2022] Open
Abstract
MHC glycoproteins form supramolecular clusters with interleukin-2 and -15 receptors in lipid rafts of T cells. The role of highly expressed MHC I in maintaining these clusters is unknown. We knocked down MHC I in FT7.10 human T cells, and studied protein clustering at two hierarchic levels: molecular aggregations and mobility by Förster resonance energy transfer and fluorescence correlation spectroscopy; and segregation into larger domains or superclusters by superresolution stimulated emission depletion microscopy. Fluorescence correlation spectroscopy-based molecular brightness analysis revealed that the studied molecules diffused as tight aggregates of several proteins of a kind. Knockdown reduced the number of MHC I containing molecular aggregates and their average MHC I content, and decreased the heteroassociation of MHC I with IL-2Rα/IL-15Rα. The mobility of not only MHC I but also that of IL-2Rα/IL-15Rα increased, corroborating the general size decrease of tight aggregates. A multifaceted analysis of stimulated emission depletion images revealed that the diameter of MHC I superclusters diminished from 400-600 to 200-300 nm, whereas those of IL-2Rα/IL-15Rα hardly changed. MHC I and IL-2Rα/IL-15Rα colocalized with GM1 ganglioside-rich lipid rafts, but MHC I clusters retracted to smaller subsets of GM1- and IL-2Rα/IL-15Rα-rich areas upon knockdown. Our results prove that changes in expression level may significantly alter the organization and mobility of interacting membrane proteins.
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Affiliation(s)
- Gábor Mocsár
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Julianna Volkó
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Daniel Rönnlund
- Department of Applied Physics/Experimental Biomolecular Physics, Royal Institute of Technology, Albanova University Center, Stockholm, Sweden
| | - Jerker Widengren
- Department of Applied Physics/Experimental Biomolecular Physics, Royal Institute of Technology, Albanova University Center, Stockholm, Sweden
| | - Péter Nagy
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - János Szöllősi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary; Cell Biology and Signaling Research Group of the Hungarian Academy of Sciences and the University of Debrecen, Debrecen, Hungary
| | - Katalin Tóth
- German Cancer Research Center, Biophysics of Macromolecules, Heidelberg, Germany
| | - Carolyn K Goldman
- Lymphoid Malignancies Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Sándor Damjanovich
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Thomas A Waldmann
- Lymphoid Malignancies Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Andrea Bodnár
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - György Vámosi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
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13
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Buchholz J, Krieger JW, Mocsár G, Kreith B, Charbon E, Vámosi G, Kebschull U, Langowski J. FPGA implementation of a 32x32 autocorrelator array for analysis of fast image series. Opt Express 2012; 20:17767-82. [PMID: 23038328 DOI: 10.1364/oe.20.017767] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
With the evolving technology in CMOS integration, new classes of 2D-imaging detectors have recently become available. In particular, single photon avalanche diode (SPAD) arrays allow detection of single photons at high acquisition rates (≥ 100 kfps), which is about two orders of magnitude higher than with currently available cameras. Here we demonstrate the use of a SPAD array for imaging fluorescence correlation spectroscopy (imFCS), a tool to create 2D maps of the dynamics of fluorescent molecules inside living cells. Time-dependent fluorescence fluctuations, due to fluorophores entering and leaving the observed pixels, are evaluated by means of autocorrelation analysis. The multi-τ correlation algorithm is an appropriate choice, as it does not rely on the full data set to be held in memory. Thus, this algorithm can be efficiently implemented in custom logic. We describe a new implementation for massively parallel multi-τ correlation hardware. Our current implementation can calculate 1024 correlation functions at a resolution of 10 μs in real-time and therefore correlate real-time image streams from high speed single photon cameras with thousands of pixels.
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Affiliation(s)
- Jan Buchholz
- German Cancer Research Center (DKFZ), Biophysics of Macromolecules (B040), Im Neuenheimer Feld 580, D-69120 Heidelberg, Germany
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14
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Mocsár G, Kreith B, Buchholz J, Krieger JW, Langowski J, Vámosi G. Note: multiplexed multiple-tau auto- and cross-correlators on a single field programmable gate array. Rev Sci Instrum 2012; 83:046101. [PMID: 22559587 DOI: 10.1063/1.3700810] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [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
We introduce a new multiple-tau hardware correlator design for computing fluorescence correlation functions (CFs) in real time. Use of hardware resources is minimized by scheduling the computation of different segments of the CFs on a single correlator block. Simultaneous calculation of two multiple-tau autocorrelation (ACFs) and two cross-correlation functions (CCFs) is implemented in LabVIEW on a National Instruments field programmable gate array (FPGA) card with a minimal sampling time of 400 ns. Raw data are stored with a time resolution of 50 ns. The design can be easily adapted to other FPGA cards and extended to more inputs.
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Affiliation(s)
- G Mocsár
- Department of Biophysics and Cell Biology, Medical and Health Science Center, University of Debrecen, Debrecen 4032, Hungary
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15
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Beck Z, Balogh A, Kis A, Izsépi E, Cervenak L, László G, Bíró A, Liliom K, Mocsár G, Vámosi G, Füst G, Matko J. New cholesterol-specific antibodies remodel HIV-1 target cells' surface and inhibit their in vitro virus production. J Lipid Res 2009; 51:286-96. [PMID: 19654424 DOI: 10.1194/jlr.m000372] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [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
The importance of membrane rafts in HIV-1 infection is still in the focus of interest. Here, we report that new monoclonal anticholesterol IgG antibodies (ACHAs), recognizing clustered membrane cholesterol (e.g., in lipid rafts), rearrange the lateral molecular organization of HIV-1 receptors and coreceptors in the plasma membrane of HIV-1 permissive human T-cells and macrophages. This remodeling is accompanied with a substantial inhibition of their infection and HIV-1 production in vitro. ACHAs promote the association of CXCR4 with both CD4 and lipid rafts, consistent with the decreased lateral mobility of CXCR4, while Fab fragments of ACHAs do not show these effects. ACHAs do not directly mask the extracellular domains of either CD4 or CXCR4 nor do they affect CXCR4 internalization. No significant inhibition of HIV production is seen when the virus is preincubated with the antibodies prior to infection. Thus, we propose that the observed inhibition is mainly due to the membrane remodeling induced by cholesterol-specific antibodies on the target cells. This, in turn, may prevent the proper spatio-temporal juxtaposition of HIV-1 glycoproteins with CD4 and chemokine receptors, thus negatively interfering with virus attachment/entry.
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Affiliation(s)
- Zoltán Beck
- Institute of Medical Microbiology, University of Debrecen, H-4012, Debrecen, Hungary
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16
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Erdélyi K, Bai P, Kovács I, Szabó E, Mocsár G, Kakuk A, Szabó C, Gergely P, Virág L. Dual role of poly(ADP-ribose) glycohydrolase in the regulation of cell death in oxidatively stressed A549 cells. FASEB J 2009. [PMID: 19571039 DOI: 10.1096/fj.09-133264+fj.09-133264+[pii]] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Activation of poly(ADP-ribose) polymerase-1 (PARP1) has been shown to mediate cell death induced by genotoxic stimuli. The role of poly(ADP-ribose) glycohydrolase (PARG), the enzyme responsible for polymer degradation, has been largely unexplored in the regulation of cell death. Using lentiviral gene silencing we generated A549 lung adenocarcinoma cell lines with stably suppressed PARG and PARP1 expression (shPARG and shPARP1 cell lines, respectively) and determined parameters of apoptotic and necrotic cell death following hydrogen peroxide exposure. shPARG cells accumulated large amounts of poly(ADP-ribosyl)ated proteins and exhibited reduced PARP activation. Hydrogen peroxide-induced cell death is regulated by PARG in a dual fashion. Whereas the shPARG cell line (similarly to shPARP1 cells) was resistant to the necrotic effect of high concentrations of hydrogen peroxide, these cells exhibited stronger apoptotic response. Both shPARP1 and especially shPARG cells displayed a delayed repair of DNA breaks and exhibited reduced clonogenic survival following hydrogen peroxide treatment. Translocation of apoptosis-inducing factor could not be observed, but cells could be saved by methyl pyruvate and alpha-ketoglutarate, indicating that energy failure may mediate cytotoxicity in our model. These data indicate that PARG is a survival factor at mild oxidative damage but contributes to the apoptosis-necrosis switch in severely damaged cells.
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Affiliation(s)
- Katalin Erdélyi
- Department of Medical Chemistry, Medical and Health Science Center, University of Debrecen, H-4032 Debrecen, Hungary
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17
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Erdélyi K, Bai P, Kovács I, Szabó E, Mocsár G, Kakuk A, Szabó C, Gergely P, Virág L. Dual role of poly(ADP-ribose) glycohydrolase in the regulation of cell death in oxidatively stressed A549 cells. FASEB J 2009; 23:3553-63. [PMID: 19571039 DOI: 10.1096/fj.09-133264] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Activation of poly(ADP-ribose) polymerase-1 (PARP1) has been shown to mediate cell death induced by genotoxic stimuli. The role of poly(ADP-ribose) glycohydrolase (PARG), the enzyme responsible for polymer degradation, has been largely unexplored in the regulation of cell death. Using lentiviral gene silencing we generated A549 lung adenocarcinoma cell lines with stably suppressed PARG and PARP1 expression (shPARG and shPARP1 cell lines, respectively) and determined parameters of apoptotic and necrotic cell death following hydrogen peroxide exposure. shPARG cells accumulated large amounts of poly(ADP-ribosyl)ated proteins and exhibited reduced PARP activation. Hydrogen peroxide-induced cell death is regulated by PARG in a dual fashion. Whereas the shPARG cell line (similarly to shPARP1 cells) was resistant to the necrotic effect of high concentrations of hydrogen peroxide, these cells exhibited stronger apoptotic response. Both shPARP1 and especially shPARG cells displayed a delayed repair of DNA breaks and exhibited reduced clonogenic survival following hydrogen peroxide treatment. Translocation of apoptosis-inducing factor could not be observed, but cells could be saved by methyl pyruvate and alpha-ketoglutarate, indicating that energy failure may mediate cytotoxicity in our model. These data indicate that PARG is a survival factor at mild oxidative damage but contributes to the apoptosis-necrosis switch in severely damaged cells.
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Affiliation(s)
- Katalin Erdélyi
- Department of Medical Chemistry, Medical and Health Science Center, University of Debrecen, H-4032 Debrecen, Hungary
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18
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Erdélyi K, Bai P, Kovács I, Szabó É, Mocsár G, Kakuk A, Szabó C, Gergely P, Virág L. Dual role of poly(ADP‐ribose) glycohydrolase in the regulation of cell death in oxidatively stressed A549 cells. FASEB J 2009. [DOI: 10.1096/fj.09-133264 fj.09-133264 [pii]] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Katalin Erdélyi
- Department of Medical Chemistry Medical and Health Science Center University of Debrecen Debrecen Hungary
- Cell Biology and Signaling Research Group of the Hungarian Academy of Sciences Research Center for Molecular Medicine Debrecen Hungary
| | - Péter Bai
- Department of Medical Chemistry Medical and Health Science Center University of Debrecen Debrecen Hungary
| | - István Kovács
- Department of Medical Chemistry Medical and Health Science Center University of Debrecen Debrecen Hungary
| | - Éva Szabó
- Department of Dermatology Medical and Health Science Center University of Debrecen Debrecen Hungary
| | - Gábor Mocsár
- Department of Biophysics and Cell Biology Medical and Health Science Center University of Debrecen Debrecen Hungary
- Cell Biology and Signaling Research Group of the Hungarian Academy of Sciences Research Center for Molecular Medicine Debrecen Hungary
| | - Annamária Kakuk
- Department of Medical Chemistry Medical and Health Science Center University of Debrecen Debrecen Hungary
| | - Csaba Szabó
- Department of Anesthesiology University of Texas Medical Branch Galveston Texas USA
| | - Pál Gergely
- Department of Medical Chemistry Medical and Health Science Center University of Debrecen Debrecen Hungary
- Cell Biology and Signaling Research Group of the Hungarian Academy of Sciences Research Center for Molecular Medicine Debrecen Hungary
| | - László Virág
- Department of Medical Chemistry Medical and Health Science Center University of Debrecen Debrecen Hungary
- Cell Biology and Signaling Research Group of the Hungarian Academy of Sciences Research Center for Molecular Medicine Debrecen Hungary
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