1
|
Koifman N, Nir-Shapira M, Talmon Y. Selective labeling of phosphatidylserine for cryo-TEM by a two-step immunogold method. J Struct Biol 2023; 215:108025. [PMID: 37678713 DOI: 10.1016/j.jsb.2023.108025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 08/14/2023] [Accepted: 09/04/2023] [Indexed: 09/09/2023]
Abstract
Immunogold labeling in transmission electron microscopy (TEM) utilizes the high electron density of gold nanoparticles conjugated to proteins to identify specific antigens in biological samples. In this work we applied the concept of immunogold labeling for the labeling of negatively charged phospholipids, namely phosphatidylserine, by a simple protocol, performed entirely in the liquid-phase, from which cryo-TEM specimens can be directly prepared. Labeling included a two-step process using biotinylated annexin-V and gold-conjugated streptavidin. We initially applied it on liposomal systems, demonstrating its specificity and selectivity, differentiating between 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 1,2-dioleoyl-sn-glycero-3-phospho-l-serine (DOPS) membranes. We also observed specific labeling on extracellular vesicle samples isolated from THP1 cells and from MDA-468 cells, which underwent stimulations. Finally, we compared the levels of annexin-V labeling on the cells vs. on their isolated EVs by flow cytometry and found a good correlation with the cryo-TEM results. This simple, yet effective labeling technique makes it possible to differentiate between negatively charged and non-negatively charged membranes, thus shillucidating their possible EV shedding mechanism.
Collapse
Affiliation(s)
- Na'ama Koifman
- Department of Chemical Engineering and the Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel.
| | - Maayan Nir-Shapira
- Department of Chemical Engineering and the Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel.
| | - Yeshayahu Talmon
- Department of Chemical Engineering and the Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 3200003, Israel.
| |
Collapse
|
2
|
Lamberti G, De Smet CH, Angelova M, Kremser L, Taub N, Herrmann C, Hess MW, Rainer J, Tancevski I, Schweigreiter R, Kofler R, Schmiedinger T, Vietor I, Trajanoski Z, Ejsing CS, Lindner HH, Huber LA, Stasyk T. LAMTOR/Ragulator regulates lipid metabolism in macrophages and foam cell differentiation. FEBS Lett 2019; 594:31-42. [PMID: 31423582 PMCID: PMC7003824 DOI: 10.1002/1873-3468.13579] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 07/30/2019] [Accepted: 07/31/2019] [Indexed: 11/08/2022]
Abstract
Late endosomal/lysosomal adaptor and MAPK and mTOR activator (LAMTOR/Ragulator) is a scaffold protein complex that anchors and regulates multiprotein signaling units on late endosomes/lysosomes. To identify LAMTOR‐modulated endolysosomal proteins, primary macrophages were derived from bone marrow of conditional knockout mice carrying a specific deletion of LAMTOR2 in the monocyte/macrophage cell lineage. Affymetrix‐based transcriptomic analysis and quantitative iTRAQ‐based organelle proteomic analysis of endosomes derived from macrophages were performed. Further analyses showed that LAMTOR could be a novel regulator of foam cell differentiation. The lipid droplet formation phenotype observed in macrophages was additionally confirmed in MEFs, where lipidomic analysis identified cholesterol esters as specifically downregulated in LAMTOR2 knockout cells. The data obtained indicate a function of LAMTOR2 in lipid metabolism.
Collapse
Affiliation(s)
- Giorgia Lamberti
- Division of Cell Biology, Biocenter, Medical University of Innsbruck, Austria
| | - Cedric H De Smet
- Division of Cell Biology, Biocenter, Medical University of Innsbruck, Austria
| | - Mihaela Angelova
- Division of Bioinformatics, Biocenter, Medical University of Innsbruck, Austria
| | - Leopold Kremser
- Division of Clinical Biochemistry, Biocenter, Medical University of Innsbruck, Austria
| | - Nicole Taub
- Division of Cell Biology, Biocenter, Medical University of Innsbruck, Austria
| | - Caroline Herrmann
- Division of Cell Biology, Biocenter, Medical University of Innsbruck, Austria
| | - Michael W Hess
- Division of Histology and Embryology, Medical University of Innsbruck, Austria
| | - Johannes Rainer
- Division of Molecular Pathophysiology, Biocenter, Medical University of Innsbruck, Austria
| | - Ivan Tancevski
- Department of Internal Medicine, Medical University of Innsbruck, Austria
| | | | - Reinhard Kofler
- Division of Molecular Pathophysiology, Biocenter, Medical University of Innsbruck, Austria
| | - Thomas Schmiedinger
- Department of Therapeutic Radiology and Oncology, Medical University of Innsbruck, Austria
| | - Ilja Vietor
- Division of Cell Biology, Biocenter, Medical University of Innsbruck, Austria
| | - Zlatko Trajanoski
- Division of Bioinformatics, Biocenter, Medical University of Innsbruck, Austria
| | - Christer S Ejsing
- Department of Biochemistry and Molecular Biology, Villum Center for Bioanalytical Sciences, University of Southern Denmark, Odense, Denmark
| | - Herbert H Lindner
- Division of Clinical Biochemistry, Biocenter, Medical University of Innsbruck, Austria
| | - Lukas A Huber
- Division of Cell Biology, Biocenter, Medical University of Innsbruck, Austria.,Austrian Drug Screening Institute, ADSI, Innsbruck, Austria
| | - Taras Stasyk
- Division of Cell Biology, Biocenter, Medical University of Innsbruck, Austria
| |
Collapse
|
3
|
Schmidle G, Ebner HL, Klima G, Pfaller K, Fritz J, Hoermann R, Gabl M. Time-dependent changes in bone healing capacity of scaphoid fractures and non-unions. J Anat 2018; 232:908-918. [PMID: 29488208 PMCID: PMC5979627 DOI: 10.1111/joa.12795] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/24/2018] [Indexed: 11/30/2022] Open
Abstract
The scaphoid is the most frequently fractured carpal bone and prone to non‐union due to mechanical and biological factors. Whereas the importance of stability is well documented, the evaluation of biological activity is mostly limited to the assessment of vascularity. The purpose of this study was to select histological and immunocytochemical parameters that could be used to assess healing potential after scaphoid fractures and to correlate these findings with time intervals after fracture for the three parts of the scaphoid (distal, gap and proximal). Samples were taken during operative intervention in 33 patients with delayed or non‐union of the scaphoid. Haematoxylin and Eosin (HE), Azan, Toluidine, von Kossa and Tartrate‐resistant acid phosphatase (TRAP) staining were used to characterise the samples histologically. We determined distribution of collagen 1 and 2 by immunocytochemistry, and scanning electron microscopy (SEM) was used to investigate the ultrastructure. To analyse the samples, parameters for biological healing status were defined and grouped according to healing capacity in parameters with high, partial and little biological activity. These findings allowed scoring of biological healing capacity, and the ensuing results were correlated with different time intervals after fracture. The results showed reduced healing capacity over time, but not all parts of the scaphoid were affected in the same way. For the distal fragment, regression analysis showed a statistically significant correlation between summarised healing activity scores and time from initial fracture (r = −0.427, P = 0.026) and decreasing healing activity for the gap region (r = −0.339, P = 0.090). In contrast, the analyses of the proximal parts for all patients did not show a correlation (r = 0.008, P = 0.969) or a decrease in healing capacity, with reduced healing capacity already at early stages. The histological and immunocytochemical characterisation of scaphoid non‐unions (SNUs) and the scoring of healing parameters make it possible to analyse the healing capacity of SNUs at certain time points. This information is important as it can assist the surgeon in the selection of the most appropriate SNU treatment.
Collapse
Affiliation(s)
- Gernot Schmidle
- Department of Trauma Surgery, Medical University Innsbruck, Innsbruck, Austria
| | | | - Günter Klima
- Division of Histology and Embryology, Medical University Innsbruck, Innsbruck, Austria
| | - Kristian Pfaller
- Division of Histology and Embryology, Medical University Innsbruck, Innsbruck, Austria
| | - Josef Fritz
- Department of Medical Statistics, Informatics and Health Economics, Medical University Innsbruck, Innsbruck, Austria
| | - Romed Hoermann
- Division of Clinical and Functional Anatomy, Medical University Innsbruck, Innsbruck, Austria
| | - Markus Gabl
- Department of Trauma Surgery, Medical University Innsbruck, Innsbruck, Austria
| |
Collapse
|
4
|
Adell MAY, Migliano SM, Upadhyayula S, Bykov YS, Sprenger S, Pakdel M, Vogel GF, Jih G, Skillern W, Behrouzi R, Babst M, Schmidt O, Hess MW, Briggs JA, Kirchhausen T, Teis D. Recruitment dynamics of ESCRT-III and Vps4 to endosomes and implications for reverse membrane budding. eLife 2017; 6:31652. [PMID: 29019322 PMCID: PMC5665648 DOI: 10.7554/elife.31652] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 09/25/2017] [Indexed: 12/18/2022] Open
Abstract
The ESCRT machinery mediates reverse membrane scission. By quantitative fluorescence lattice light-sheet microscopy, we have shown that ESCRT-III subunits polymerize rapidly on yeast endosomes, together with the recruitment of at least two Vps4 hexamers. During their 3–45 s lifetimes, the ESCRT-III assemblies accumulated 75–200 Snf7 and 15–50 Vps24 molecules. Productive budding events required at least two additional Vps4 hexamers. Membrane budding was associated with continuous, stochastic exchange of Vps4 and ESCRT-III components, rather than steady growth of fixed assemblies, and depended on Vps4 ATPase activity. An all-or-none step led to final release of ESCRT-III and Vps4. Tomographic electron microscopy demonstrated that acute disruption of Vps4 recruitment stalled membrane budding. We propose a model in which multiple Vps4 hexamers (four or more) draw together several ESCRT-III filaments. This process induces cargo crowding and inward membrane buckling, followed by constriction of the nascent bud neck and ultimately ILV generation by vesicle fission.
Collapse
Affiliation(s)
- Manuel Alonso Y Adell
- Division of Cell Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Simona M Migliano
- Division of Cell Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Srigokul Upadhyayula
- Department of Pediatrics, Harvard Medical School, Boston, United States.,Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, United States.,Department of Cell Biology, Harvard Medical School, Boston, United States
| | - Yury S Bykov
- Structural and Computational Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Simon Sprenger
- Division of Cell Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Mehrshad Pakdel
- Division of Cell Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria.,Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Georg F Vogel
- Division of Cell Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria.,Division of Histology and Embryology, Medical University of Innsbruck, Innsbruck, Austria
| | - Gloria Jih
- Department of Cell Biology, Harvard Medical School, Boston, United States
| | - Wesley Skillern
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, United States
| | - Reza Behrouzi
- Department of Cell Biology, Harvard Medical School, Boston, United States
| | - Markus Babst
- Department of Biology, University of Utah, Utah, United States.,Center for Cell and Genome Science, University of Utah, Utah, United States
| | - Oliver Schmidt
- Division of Cell Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Michael W Hess
- Division of Histology and Embryology, Medical University of Innsbruck, Innsbruck, Austria
| | - John Ag Briggs
- Structural and Computational Unit, European Molecular Biology Laboratory, Heidelberg, Germany.,Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Tomas Kirchhausen
- Department of Pediatrics, Harvard Medical School, Boston, United States.,Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, United States.,Department of Cell Biology, Harvard Medical School, Boston, United States
| | - David Teis
- Division of Cell Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria.,Austrian Drug Screening Institute, Innsbruck, Austria
| |
Collapse
|
5
|
Cryo-Immuno Electron Microscopy of Peroxisomal Marker Proteins. Methods Mol Biol 2017. [PMID: 28409456 DOI: 10.1007/978-1-4939-6937-1_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Electron microscopy samples processed for cryo-immunogold-labeling need to be gently fixed to keep their antigenicity. Biological material like cultured cells or tissue can be prepared according to the standard Tokuyasu fixation or in a further developed rehydration method based on high-pressure freezing. We will describe here the variant and common steps of both methods in detail and illustrate their potency in the ultrastructural imaging of peroxisomes.
Collapse
|
6
|
Moll CWI, Schmiedinger T, Moll MA, Seppi T, Pfaller K, Hess MW, Gutleben K, Lindtner RA, Blauth M, Krumschnabel G, Ebner HL. Extracellular matrix mimicking scaffold promotes osteogenic stem cell differentiation: A new approach in osteoporosis research. Biomed Mater Eng 2017; 28:87-103. [PMID: 28372263 DOI: 10.3233/bme-171659] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
BACKGROUND Osteoporosis is a common metabolic disease, with mesenchymal stem cells discussed to play an important role in its pathomechanism. For in vitro osteoporosis studies, selection of adequate culture conditions is mandatory so as to preserve cell properties as far as possible. A suitable cell culture surface would ideally provide reproducible experimental conditions by resembling those in-vivo. OBJECTIVE Generating an improved growth surface for osteogenic differentiation of human bone marrow derived mesenchymal stem cells (hBMSCs). METHODS We modified electrospun gelatine meshes with hydroxyapatite nanopowder. The potential beneficial impact of the ensuing culture conditions were evaluated by cultivating and comparing the growth of cells from osteoporotic and non-osteoporotic donors on either hydroxyapatite-gelatine (HA) meshes, pure gelatine meshes, or 2D standard tissue culture surfaces. RESULTS After 21 days of differentiation, cells grown on pure or HA-gelatine meshes showed significantly higher mineralization levels compared to cells cultured in standard conditions. The amount of mineralization varied considerably in hBMSC cultures of individual patients but showed no significant difference between stem cells obtained from osteoporotic or non-osteoporotic donors. CONCLUSIONS Overall, these results indicate that the use of HA-gelatine meshes as growth surfaces may serve as a valuable tool for cultivation and differentiation of mesenchymal stem cells along the osteogenic lineage, facilitating future research on osteoporosis and related issues.
Collapse
Affiliation(s)
- C W I Moll
- Department of Trauma Surgery, Medical University, Anichstrasse 35, Innsbruck, Austria
| | - T Schmiedinger
- Department of Therapeutic Radiology and Oncology, Medical University, Anichstrasse 35, Innsbruck, Austria
| | - M A Moll
- Department of Vascular Surgery, Medical University, Anichstrasse 35, Innsbruck, Austria
| | - T Seppi
- Department of Therapeutic Radiology and Oncology, Medical University, Anichstrasse 35, Innsbruck, Austria
| | - K Pfaller
- Division of Histology and Embryology, Medical University, Müllerstrasse 59, Innsbruck, Austria
| | - M W Hess
- Division of Histology and Embryology, Medical University, Müllerstrasse 59, Innsbruck, Austria
| | - K Gutleben
- Division of Histology and Embryology, Medical University, Müllerstrasse 59, Innsbruck, Austria
| | - R A Lindtner
- Department of Trauma Surgery, Medical University, Anichstrasse 35, Innsbruck, Austria
| | - M Blauth
- Department of Trauma Surgery, Medical University, Anichstrasse 35, Innsbruck, Austria
| | - G Krumschnabel
- OROBOROS® INSTRUMENTS Corporation (GmbH), Schöpfstrasse 18, Innsbruck, Austria
| | - H L Ebner
- Department of Trauma Surgery, Medical University, Anichstrasse 35, Innsbruck, Austria.,MED-EL Medical Electronics (GmbH), Fürstenweg 77a, Innsbruck, Austria
| |
Collapse
|
7
|
Vogel GF, Ebner HL, de Araujo MEG, Schmiedinger T, Eiter O, Pircher H, Gutleben K, Witting B, Teis D, Huber LA, Hess MW. Ultrastructural Morphometry Points to a New Role for LAMTOR2 in Regulating the Endo/Lysosomal System. Traffic 2015; 16:617-34. [DOI: 10.1111/tra.12271] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Revised: 02/09/2015] [Accepted: 02/09/2015] [Indexed: 12/13/2022]
Affiliation(s)
- Georg F. Vogel
- Division of Histology and Embryology; Medical University of Innsbruck; Müllerstrasse 59 A-6020 Innsbruck Austria
- Division of Cell Biology, Biocenter; Medical University of Innsbruck; Innrain 80-82 A-6020 Innsbruck Austria
| | - Hannes L. Ebner
- Division of Histology and Embryology; Medical University of Innsbruck; Müllerstrasse 59 A-6020 Innsbruck Austria
- Current address: Department for Trauma Surgery; Medical University of Innsbruck; Anichstrasse 35 A-6020 Innsbruck Austria
| | - Mariana E. G. de Araujo
- Division of Cell Biology, Biocenter; Medical University of Innsbruck; Innrain 80-82 A-6020 Innsbruck Austria
| | - Thomas Schmiedinger
- Department of Therapeutic Radiology and Oncology; Medical University of Innsbruck; Anichstrasse 35 A-6020 Innsbruck Austria
| | - Oliver Eiter
- Department of Therapeutic Radiology and Oncology; Medical University of Innsbruck; Anichstrasse 35 A-6020 Innsbruck Austria
| | - Haymo Pircher
- Research Institute for Biomedical Aging Research; University of Innsbruck; Rennweg 10 A-6020 Innsbruck Austria
| | - Karin Gutleben
- Division of Histology and Embryology; Medical University of Innsbruck; Müllerstrasse 59 A-6020 Innsbruck Austria
| | - Barbara Witting
- Division of Histology and Embryology; Medical University of Innsbruck; Müllerstrasse 59 A-6020 Innsbruck Austria
| | - David Teis
- Division of Cell Biology, Biocenter; Medical University of Innsbruck; Innrain 80-82 A-6020 Innsbruck Austria
| | - Lukas A. Huber
- Division of Cell Biology, Biocenter; Medical University of Innsbruck; Innrain 80-82 A-6020 Innsbruck Austria
| | - Michael W. Hess
- Division of Histology and Embryology; Medical University of Innsbruck; Müllerstrasse 59 A-6020 Innsbruck Austria
| |
Collapse
|