151
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Zhang X, Tang Q, Wu L, Huang J, Chen Y. AFM visualization of cortical filaments/network under cell-bound membrane vesicles. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:2225-32. [PMID: 26141051 DOI: 10.1016/j.bbamem.2015.06.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 06/16/2015] [Accepted: 06/29/2015] [Indexed: 01/08/2023]
Abstract
While circulating/plasma membrane vesicles have been extensively characterized, due to the lack of effective methods cell-bound membrane vesicles are poorly understood including their shape and correlation with the intracellular cytoskeleton. In this study, we focused on cell-bound membrane vesicles and individual vesicle-derived pits on endothelial cells by using confocal microscopy and atomic force microscopy (AFM). For the first time, we found that cell-bound membrane vesicles are hemisphere-shaped and that the actin cortical filaments/network lies at the cytosolic opening of a vesicle instead of being closely attached to the inner side of the vesicle membrane. This structure of cell-bound membrane vesicles may be beneficial to their movement in, or release from, the plasma membrane of cells due to less membrane-cytoskeleton coupling to be broken therefore probably minimizing energy consumption and time usage. Further study indicates that TNF-α activation induced a significant increase in average number/size of cell-bound vesicles and the local disruption of the actin network at the cytosolic opening of cell-bound vesicles.
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Affiliation(s)
- Xiaojun Zhang
- Nanoscale Science and Technology Laboratory, Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi 330031, P. R. China
| | - Qisheng Tang
- Nanoscale Science and Technology Laboratory, Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi 330031, P. R. China
| | - Li Wu
- School of Basic Medical Sciences, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi 330025, P. R. China
| | - Jie Huang
- The Third Hospital of Jiujiang, Jiujiang, Jiangxi 332000, P. R. China
| | - Yong Chen
- Nanoscale Science and Technology Laboratory, Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi 330031, P. R. China.
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152
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Nanoscale monitoring of drug actions on cell membrane using atomic force microscopy. Acta Pharmacol Sin 2015; 36:769-82. [PMID: 26027658 DOI: 10.1038/aps.2015.28] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Accepted: 03/13/2015] [Indexed: 02/06/2023] Open
Abstract
Knowledge of the nanoscale changes that take place in individual cells in response to a drug is useful for understanding the drug action. However, due to the lack of adequate techniques, such knowledge was scarce until the advent of atomic force microscopy (AFM), which is a multifunctional tool for investigating cellular behavior with nanometer resolution under near-physiological conditions. In the past decade, researchers have applied AFM to monitor the morphological and mechanical dynamics of individual cells following drug stimulation, yielding considerable novel insight into how the drug molecules affect an individual cell at the nanoscale. In this article we summarize the representative applications of AFM in characterization of drug actions on cell membrane, including topographic imaging, elasticity measurements, molecular interaction quantification, native membrane protein imaging and manipulation, etc. The challenges that are hampering the further development of AFM for studies of cellular activities are aslo discussed.
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153
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Formosa C, Herold M, Vidaillac C, Duval RE, Dague E. Unravelling of a mechanism of resistance to colistin inKlebsiella pneumoniaeusing atomic force microscopy. J Antimicrob Chemother 2015; 70:2261-70. [DOI: 10.1093/jac/dkv118] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 04/08/2015] [Indexed: 11/13/2022] Open
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154
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te Riet J, Reinieren-Beeren I, Figdor CG, Cambi A. AFM force spectroscopy reveals how subtle structural differences affect the interaction strength betweenCandida albicansand DC-SIGN. J Mol Recognit 2015; 28:687-98. [DOI: 10.1002/jmr.2481] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 04/24/2015] [Accepted: 04/27/2015] [Indexed: 11/07/2022]
Affiliation(s)
- Joost te Riet
- Department of Tumor Immunology; Radboud Institute for Molecular Life Sciences, Radboud UMC; P.O. Box 9101 6500HB Nijmegen The Netherlands
| | - Inge Reinieren-Beeren
- Department of Tumor Immunology; Radboud Institute for Molecular Life Sciences, Radboud UMC; P.O. Box 9101 6500HB Nijmegen The Netherlands
| | - Carl G. Figdor
- Department of Tumor Immunology; Radboud Institute for Molecular Life Sciences, Radboud UMC; P.O. Box 9101 6500HB Nijmegen The Netherlands
| | - Alessandra Cambi
- Department of Tumor Immunology; Radboud Institute for Molecular Life Sciences, Radboud UMC; P.O. Box 9101 6500HB Nijmegen The Netherlands
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155
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Grant CA, Twigg PC, Baker R, Tobin DJ. Tattoo ink nanoparticles in skin tissue and fibroblasts. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2015; 6:1183-1191. [PMID: 26171294 PMCID: PMC4464189 DOI: 10.3762/bjnano.6.120] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 04/22/2015] [Indexed: 06/04/2023]
Abstract
Tattooing has long been practised in various societies all around the world and is becoming increasingly common and widespread in the West. Tattoo ink suspensions unquestionably contain pigments composed of nanoparticles, i.e., particles of sub-100 nm dimensions. It is widely acknowledged that nanoparticles have higher levels of chemical activity than their larger particle equivalents. However, assessment of the toxicity of tattoo inks has been the subject of little research and ink manufacturers are not obliged to disclose the exact composition of their products. This study examines tattoo ink particles in two fundamental skin components at the nanometre level. We use atomic force microscopy and light microscopy to examine cryosections of tattooed skin, exploring the collagen fibril networks in the dermis that contain ink nanoparticles. Further, we culture fibroblasts in diluted tattoo ink to explore both the immediate impact of ink pigment on cell viability and also to observe the interaction between particles and the cells.
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Affiliation(s)
- Colin A Grant
- Advanced Materials Engineering, Faculty of Engineering and Informatics, University of Bradford, Bradford, BD7 1DP, United Kingdom
| | - Peter C Twigg
- Advanced Materials Engineering, Faculty of Engineering and Informatics, University of Bradford, Bradford, BD7 1DP, United Kingdom
| | - Richard Baker
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Bradford, BD7 1DP, United Kingdom
| | - Desmond J Tobin
- Centre for Skin Sciences, Faculty of Life Sciences, University of Bradford, Bradford, BD7 1DP, United Kingdom
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156
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Bhat SV, Booth SC, McGrath SGK, Dahms TES. Rhizobium leguminosarum bv. viciae 3841 Adapts to 2,4-Dichlorophenoxyacetic Acid with "Auxin-Like" Morphological Changes, Cell Envelope Remodeling and Upregulation of Central Metabolic Pathways. PLoS One 2015; 10:e0123813. [PMID: 25919284 PMCID: PMC4412571 DOI: 10.1371/journal.pone.0123813] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 03/07/2015] [Indexed: 11/18/2022] Open
Abstract
There is a growing need to characterize the effects of environmental stressors at the molecular level on model organisms with the ever increasing number and variety of anthropogenic chemical pollutants. The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), as one of the most widely applied pesticides in the world, is one such example. This herbicide is known to have non-targeted undesirable effects on humans, animals and soil microbes, but specific molecular targets at sublethal levels are unknown. In this study, we have used Rhizobium leguminosarum bv. viciae 3841 (Rlv) as a nitrogen fixing, beneficial model soil organism to characterize the effects of 2,4-D. Using metabolomics and advanced microscopy we determined specific target pathways in the Rlv metabolic network and consequent changes to its phenotype, surface ultrastructure, and physical properties during sublethal 2,4-D exposure. Auxin and 2,4-D, its structural analogue, showed common morphological changes in vitro which were similar to bacteroids isolated from plant nodules, implying that these changes are related to bacteroid differentiation required for nitrogen fixation. Rlv showed remarkable adaptation capabilities in response to the herbicide, with changes to integral pathways of cellular metabolism and the potential to assimilate 2,4-D with consequent changes to its physical and structural properties. This study identifies biomarkers of 2,4-D in Rlv and offers valuable insights into the mode-of-action of 2,4-D in soil bacteria.
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Affiliation(s)
- Supriya V. Bhat
- Department of Chemistry and Biochemistry, University of Regina, 3737 Wascana Parkway, Regina, SK, S4S 0A2 Canada
| | - Sean C. Booth
- Department of Biological Sciences, University of Calgary, 2500 University Dr, NW Calgary, AB, T2N 1N4 Canada
| | - Seamus G. K. McGrath
- Department of Chemistry and Biochemistry, University of Regina, 3737 Wascana Parkway, Regina, SK, S4S 0A2 Canada
| | - Tanya E. S. Dahms
- Department of Chemistry and Biochemistry, University of Regina, 3737 Wascana Parkway, Regina, SK, S4S 0A2 Canada
- * E-mail:
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157
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The Evaluation of Magnetic Polymethacrylate-based Microspheres Used for Solid Phase DNA Micro-Extraction. CHROMATOGRAPHY 2015. [DOI: 10.3390/chromatography2020156] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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158
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Daza R, Cruces J, Arroyo-Hernández M, Marí-Buyé N, De la Fuente M, Plaza GR, Elices M, Pérez-Rigueiro J, Guinea GV. Topographical and mechanical characterization of living eukaryotic cells on opaque substrates: development of a general procedure and its application to the study of non-adherent lymphocytes. Phys Biol 2015; 12:026005. [DOI: 10.1088/1478-3975/12/2/026005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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159
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Analysis of biosurfaces by neutron reflectometry: from simple to complex interfaces. Biointerphases 2015; 10:019014. [PMID: 25779088 DOI: 10.1116/1.4914948] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Because of its high sensitivity for light elements and the scattering contrast manipulation via isotopic substitutions, neutron reflectometry (NR) is an excellent tool for studying the structure of soft-condensed material. These materials include model biophysical systems as well as in situ living tissue at the solid-liquid interface. The penetrability of neutrons makes NR suitable for probing thin films with thicknesses of 5-5000 Å at various buried, for example, solid-liquid, interfaces [J. Daillant and A. Gibaud, Lect. Notes Phys. 770, 133 (2009); G. Fragneto-Cusani, J. Phys.: Condens. Matter 13, 4973 (2001); J. Penfold, Curr. Opin. Colloid Interface Sci. 7, 139 (2002)]. Over the past two decades, NR has evolved to become a key tool in the characterization of biological and biomimetic thin films. In the current report, the authors would like to highlight some of our recent accomplishments in utilizing NR to study highly complex systems, including in-situ experiments. Such studies will result in a much better understanding of complex biological problems, have significant medical impact by suggesting innovative treatment, and advance the development of highly functionalized biomimetic materials.
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160
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Wu Q, Lin WD, Liao GQ, Zhang LG, Wen SQ, Lin JY. Antiproliferative effects of cinobufacini on human hepatocellular carcinoma HepG2 cells detected by atomic force microscopy. World J Gastroenterol 2015; 21:854-861. [PMID: 25624718 PMCID: PMC4299337 DOI: 10.3748/wjg.v21.i3.854] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 07/30/2014] [Accepted: 09/19/2014] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the antiproliferative activity of cinobufacini on human hepatocellular carcinoma HepG2 cells and the possible mechanism of its action.
METHODS: HepG2 cells were treated with different concentrations of cinobufacini. Cell viability was measured by methylthiazolyl tetrazolium (MTT) assay. Cell cycle distribution was analyzed by flow cytometry (FCM). Cytoskeletal and nuclear alterations were observed by fluorescein isothiocyanate-phalloidin and DAPI staining under a laser scanning confocal microscope. Changes in morphology and ultrastructure of cells were detected by atomic force microscopy (AFM) at the nanoscale level.
RESULTS: MTT assay indicated that cinobufacini significantly inhibited the viability of HepG2 cells in a dose-dependent manner. With the concentration of cinobufacini increasing from 0 to 0.10 mg/mL, the cell viability decreased from 74.9% ± 2.7% to 49.41% ± 2.2% and 39.24% ± 2.1% (P < 0.05). FCM analysis demonstrated cell cycle arrest at S phase induced by cinobufacini. The immunofluorescence studies of cytoskeletal and nuclear morphology showed that after cinobufacini treatment, the regular reorganization of actin filaments in HepG2 cells become chaotic, while the nuclei were not damaged seriously. Additionally, high-resolution AFM imaging revealed that cell morphology and ultrastructure changed a lot after treatment with cinobufacini. It appeared as significant shrinkage and deep pores in the cell membrane, with larger particles and a rougher cell surface.
CONCLUSION: Cinobufacini inhibits the viability of HepG2 cells via cytoskeletal destruction and cell membrane toxicity.
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161
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WANG CONGZHOU, STANCIU CRISTINA, EHRHARDT CHRISTOPHERJ, YADAVALLI VAMSIK. Morphological and mechanical imaging of Bacillus cereus
spore formation at the nanoscale. J Microsc 2015; 258:49-58. [DOI: 10.1111/jmi.12214] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 12/11/2014] [Indexed: 11/30/2022]
Affiliation(s)
- CONGZHOU WANG
- Department of Chemical and Life Science Engineering; Virginia Commonwealth University; Richmond Virginia 23284 U.S.A
| | - CRISTINA STANCIU
- Department of Forensic Science; Virginia Commonwealth University; Richmond Virginia 23284 U.S.A
| | - CHRISTOPHER J. EHRHARDT
- Department of Forensic Science; Virginia Commonwealth University; Richmond Virginia 23284 U.S.A
| | - VAMSI K. YADAVALLI
- Department of Chemical and Life Science Engineering; Virginia Commonwealth University; Richmond Virginia 23284 U.S.A
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162
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Multiparametric imaging of adhesive nanodomains at the surface of Candida albicans by atomic force microscopy. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2015; 11:57-65. [DOI: 10.1016/j.nano.2014.07.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 06/25/2014] [Accepted: 07/21/2014] [Indexed: 01/09/2023]
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163
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Hu X, Dinu CZ. Analysis of affinities between specific biological ligands using atomic force microscopy. Analyst 2015; 140:8118-26. [PMID: 26525901 DOI: 10.1039/c5an01748c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We used atomic force microscopy to rank the energetics of biomolecular recognition events of protein–ligand complexes.
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Affiliation(s)
- Xiao Hu
- West Virginia University
- Department of Chemical Engineering
- Morgantown
- USA
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164
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Meireles A, L. Gonçalves A, B. Gomes I, Chaves Simões L, Simões M. Methods to study microbial adhesion on abiotic surfaces. AIMS BIOENGINEERING 2015. [DOI: 10.3934/bioeng.2015.4.297] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
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165
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Analysis of long- and short-range contribution to adhesion work in cardiac fibroblasts: an atomic force microscopy study. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2014; 49:217-224. [PMID: 25686942 DOI: 10.1016/j.msec.2014.12.083] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Revised: 11/28/2014] [Accepted: 12/24/2014] [Indexed: 12/27/2022]
Abstract
Atomic force microscopy (AFM) for single-cell force spectroscopy (SCFS) and Poisson statistic were used to analyze the detachment work recorded during the removal of gold-covered microspheres from cardiac fibroblasts. The effect of Cytochalasin D, a disruptor of the actin cytoskeleton, on cell adhesion was also tested. The adhesion work was assessed using a Poisson analysis also derived from single-cell force spectroscopy retracting curves. The use of Poisson analysis to get adhesion work from AFM curves is quite a novel method, and in this case, proved to be effective to study the short-range and long-range contributions to the adhesion work. This method avoids the difficult identification of minor peaks in the AFM retracting curves by creating what can be considered an average adhesion work. Even though the effect of actin depolymerisation is well documented, its use revealed that control cardiac fibroblasts (CT) exhibit a work of adhesion at least 5 times higher than that of the Cytochalasin treated cells. However, our results indicate that in both cells short-range and long-range contributions to the adhesion work are nearly equal and the same heterogeneity index describes both cells. Therefore, we infer that the different adhesion behaviors might be explained by the presence of fewer membrane adhesion molecules available at the AFM tip-cell interface under circumstances where the actin cytoskeleton has been disrupted.
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166
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Abstract
Recent progress in surface science, nanotechnology and biophysics has cast new light on the correlation between the physicochemical properties of biomaterials and the resulting biological response. One experimental tool that promises to generate an increasingly more sophisticated knowledge of how proteins, cells and bacteria interact with nanostructured surfaces is the atomic force microscope (AFM). This unique instrument permits to close in on interfacial events at the scale at which they occur, the nanoscale. This perspective covers recent developments in the exploitation of the AFM, and suggests insights on future opportunities that can arise from the exploitation of this powerful technique.
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Affiliation(s)
- Fabio Variola
- Faculty of Engineering, Department of Mechanical Engineering, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
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167
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AKAP-dependent modulation of BCAM/Lu adhesion on normal and sickle cell disease RBCs revealed by force nanoscopy. Biophys J 2014; 106:1258-67. [PMID: 24655501 DOI: 10.1016/j.bpj.2014.02.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 01/30/2014] [Accepted: 02/03/2014] [Indexed: 02/02/2023] Open
Abstract
Human normal and sickle red blood cells (RBCs) adhere with high affinity to the alpha5 chain of laminin (LAMA5) via the basal cell adhesion molecule/Lutheran (BCAM/Lu) receptor, which is implicated in vasoocclusive episodes in sickle cell disease and activated through the cyclic adenosine monophosphate (cAMP) signaling pathway. However, the effect of the cAMP pathway on the expression of active BCAM/Lu receptors at the single-molecule level is unknown. We established an in vitro technique, based on atomic force microscopy, which enables detection of single BCAM/Lu proteins on the RBC surface and measures the unbinding force between BCAM/Lu and LAMA5. We showed that the expression of active BCAM/Lu receptors is higher in homozygous sickle RBCs (SS-RBCs) than normal RBCs and that it is critically dependent on the cAMP signaling pathway on both normal and SS-RBCs. Of importance, we illustrated that A-kinase anchoring proteins are crucial for BCAM/Lu receptor activation. Furthermore, we found that SS-RBCs from hydroxyurea-treated patients show a lower expression of active BCAM/Lu receptors, a lower unbinding force to LAMA5, and insignificant stimulation by epinephrine as compared to SS-RBCs from untreated patients. To our knowledge, these findings may lead to novel antiadhesive targets for vasoocclusive episodes in sickle cell disease.
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168
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Stirling J, Lekkas I, Sweetman A, Djuranovic P, Guo Q, Pauw B, Granwehr J, Lévy R, Moriarty P. Critical assessment of the evidence for striped nanoparticles. PLoS One 2014; 9:e108482. [PMID: 25402426 PMCID: PMC4234314 DOI: 10.1371/journal.pone.0108482] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 07/30/2014] [Indexed: 11/18/2022] Open
Abstract
There is now a significant body of literature which reports that stripes form in the ligand shell of suitably functionalised Au nanoparticles. This stripe morphology has been proposed to strongly affect the physicochemical and biochemical properties of the particles. We critique the published evidence for striped nanoparticles in detail, with a particular focus on the interpretation of scanning tunnelling microscopy (STM) data (as this is the only technique which ostensibly provides direct evidence for the presence of stripes). Through a combination of an exhaustive re-analysis of the original data, in addition to new experimental measurements of a simple control sample comprising entirely unfunctionalised particles, we show that all of the STM evidence for striped nanoparticles published to date can instead be explained by a combination of well-known instrumental artefacts, or by issues with data acquisition/analysis protocols. We also critically re-examine the evidence for the presence of ligand stripes which has been claimed to have been found from transmission electron microscopy, nuclear magnetic resonance spectroscopy, small angle neutron scattering experiments, and computer simulations. Although these data can indeed be interpreted in terms of stripe formation, we show that the reported results can alternatively be explained as arising from a combination of instrumental artefacts and inadequate data analysis techniques.
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Affiliation(s)
- Julian Stirling
- School of Physics and Astronomy, The University of Nottingham, Nottingham, United Kingdom
- * E-mail:
| | - Ioannis Lekkas
- School of Physics and Astronomy, The University of Nottingham, Nottingham, United Kingdom
| | - Adam Sweetman
- School of Physics and Astronomy, The University of Nottingham, Nottingham, United Kingdom
| | - Predrag Djuranovic
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States of America
| | - Quanmin Guo
- School of Physics and Astronomy, University of Birmingham, Birmingham, United Kingdom
| | - Brian Pauw
- International Center for Young Scientists (ICYS), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, Japan
| | - Josef Granwehr
- Sir Peter Mansfield Magnetic Resonance Centre, School of Physics and Astronomy, The University of Nottingham, Nottingham, United Kingdom
| | - Raphaël Lévy
- Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Philip Moriarty
- School of Physics and Astronomy, The University of Nottingham, Nottingham, United Kingdom
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169
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Pi J, Jin H, Yang F, Chen ZW, Cai J. In situ single molecule imaging of cell membranes: linking basic nanotechniques to cell biology, immunology and medicine. NANOSCALE 2014; 6:12229-12249. [PMID: 25227707 DOI: 10.1039/c4nr04195j] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The cell membrane, which consists of a viscous phospholipid bilayer, different kinds of proteins and various nano/micrometer-sized domains, plays a very important role in ensuring the stability of the intracellular environment and the order of cellular signal transductions. Exploring the precise cell membrane structure and detailed functions of the biomolecules in a cell membrane would be helpful to understand the underlying mechanisms involved in cell membrane signal transductions, which could further benefit research into cell biology, immunology and medicine. The detection of membrane biomolecules at the single molecule level can provide some subtle information about the molecular structure and the functions of the cell membrane. In particular, information obtained about the molecular mechanisms and other information at the single molecule level are significantly different from that detected from a large amount of biomolecules at the large-scale through traditional techniques, and can thus provide a novel perspective for the study of cell membrane structures and functions. However, the precise investigations of membrane biomolecules prompts researchers to explore cell membranes at the single molecule level by the use of in situ imaging methods, as the exact conformation and functions of biomolecules are highly controlled by the native cellular environment. Recently, the in situ single molecule imaging of cell membranes has attracted increasing attention from cell biologists and immunologists. The size of biomolecules and their clusters on the cell surface are set at the nanoscale, which makes it mandatory to use high- and super-resolution imaging techniques to realize the in situ single molecule imaging of cell membranes. In the past few decades, some amazing imaging techniques and instruments with super resolution have been widely developed for molecule imaging, which can also be further employed for the in situ single molecule imaging of cell membranes. In this review, we attempt to summarize the characteristics of these advanced techniques for use in the in situ single molecule imaging of cell membranes. We believe that this work will help to promote the technological and methodological developments of super-resolution techniques for the single molecule imaging of cell membranes and help researchers better understand which technique is most suitable for their future exploring of membrane biomolecules; ultimately promoting further developments in cell biology, immunology and medicine.
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Affiliation(s)
- Jiang Pi
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technique, Macau, China.
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170
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Burgain J, Scher J, Francius G, Borges F, Corgneau M, Revol-Junelles A, Cailliez-Grimal C, Gaiani C. Lactic acid bacteria in dairy food: surface characterization and interactions with food matrix components. Adv Colloid Interface Sci 2014; 213:21-35. [PMID: 25277266 DOI: 10.1016/j.cis.2014.09.005] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 08/30/2014] [Accepted: 09/01/2014] [Indexed: 02/07/2023]
Abstract
This review gives an overview of the importance of interactions occurring in dairy matrices between Lactic Acid Bacteria and milk components. Dairy products are important sources of biological active compounds of particular relevance to human health. These compounds include immunoglobulins, whey proteins and peptides, polar lipids, and lactic acid bacteria including probiotics. A better understanding of interactions between bioactive components and their delivery matrix may successfully improve their transport to their target site of action. Pioneering research on probiotic lactic acid bacteria has mainly focused on their host effects. However, very little is known about their interaction with dairy ingredients. Such knowledge could contribute to designing new and more efficient dairy food, and to better understand relationships between milk constituents. The purpose of this review is first to provide an overview of the current knowledge about the biomolecules produced on bacterial surface and the composition of the dairy matter. In order to understand how bacteria interact with dairy molecules, adhesion mechanisms are subsequently reviewed with a special focus on the environmental conditions affecting bacterial adhesion. Methods dedicated to investigate the bacterial surface and to decipher interactions between bacteria and abiotic dairy components are also detailed. Finally, relevant industrial implications of these interactions are presented and discussed.
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171
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A novel dog-bone oscillating AFM probe with thermal actuation and piezoresistive detection. SENSORS 2014; 14:20667-86. [PMID: 25365463 PMCID: PMC4279505 DOI: 10.3390/s141120667] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 10/13/2014] [Accepted: 10/14/2014] [Indexed: 11/17/2022]
Abstract
In order to effectively increase the resonance frequency and the quality factor of atomic force microscope (AFM) probes, a novel oscillating probe based on a dog-bone shaped MEMS resonator was conceived, designed, fabricated and evaluated. The novel probe with 400 μm in length, 100 μm in width and 5 μm in thickness was enabled to feature MHz resonance frequencies with integrated thermal actuation and piezoresistive detection. Standard silicon micromachining was employed. Both electrical and optical measurements were carried out in air. The resonance frequency and the quality factor of the novel probe were measured to be 5.4 MHz and 4000 respectively, which are much higher than those (about several hundreds of kHz) of commonly used cantilever probes. The probe was mounted onto a commercial AFM set-up through a dedicated probe-holder and circuit board. Topographic images of patterned resist samples were obtained. It is expected that the resonance frequency and the measurement bandwidth of such probes will be further increased by a proper downscaling, thus leading to a significant increase in the scanning speed capability of AFM instruments.
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173
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Bhattacharya A, Chakraborty M, Raja SO, Ghosh A, Dasgupta M, Dasgupta AK. Static magnetic field (SMF) sensing of the P(723)/P(689) photosynthetic complex. Photochem Photobiol Sci 2014; 13:1719-29. [PMID: 25314902 DOI: 10.1039/c4pp00295d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Moderate intensity SMF have been shown to act as a controller of the protic potential in the coherent milieu of the thylakoid membranes. SMF of the order of 60-500 mT induces memory-like effect in photosystem I (PSI, P723) emission with a correlated oscillation of photosystem II (PSII, P689) fluorescence emission at a temperature of 77 K. The observed magnetic perturbation that affects the thylakoid photon capture circuitry was also found to be associated with the bio-energetic machinery of the thylakoid membranes. At normal pH, SMF causes an enhancement of PSI fluorescence emission intensity (P723/P689 > 1), followed by a slow relaxation on the removal of SMF. The enhancement of the PSI fluorescence intensity also occurs under no-field condition, if either the pH of the medium is lowered, or protonophores, such as carbonyl cyanide chlorophenylhydrazine or nigericin are added (P723/P689≥ 2). If SMF was applied under such a low pH condition or in the presence of protonophore, a reverse effect, particularly, a reduction of the enhanced PSI emission was observed. Because SMF is essentially equivalent to a spin perturbation, the observed effects can be explained in terms of spin re-organization, illustrating a memory effect via membrane re-alignment and assembly. The mimicry of conventional uncouplers by SMF is also notable; the essential difference being the reversibility and manoeuvrability of the latter (SMF). Finally, the effect implies numerous possibilities of externally regulating the photon capture and proton circulation in the thylakoid membranes using controlled SMF.
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Affiliation(s)
- Abhishek Bhattacharya
- Department of Biochemistry, University of Calcutta, 35, Ballygunge Circular Road, Kolkata 700019, India.
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174
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Liao HS, Chen YH, Ding RF, Huang HF, Wang WM, Hwu ET, Huang KY, Chang CS, Hwang IS. High-speed atomic force microscope based on an astigmatic detection system. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:103710. [PMID: 25362406 DOI: 10.1063/1.4898019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
High-speed atomic force microscopy (HS-AFM) enables visualizing dynamic behaviors of biological molecules under physiological conditions at a temporal resolution of 1s or shorter. A small cantilever with a high resonance frequency is crucial in increasing the scan speed. However, detecting mechanical resonances of small cantilevers is technically challenging. In this study, we constructed an atomic force microscope using a digital versatile disc (DVD) pickup head to detect cantilever deflections. In addition, a flexure-guided scanner and a sinusoidal scan method were implemented. In this work, we imaged a grating sample in air by using a regular cantilever and a small cantilever with a resonance frequency of 5.5 MHz. Poor tracking was seen at the scan rate of 50 line/s when a cantilever for regular AFM imaging was used. Using a small cantilever at the scan rate of 100 line/s revealed no significant degradation in the topographic images. The results indicate that a smaller cantilever can achieve a higher scan rate and superior force sensitivity. This work shows the potential for using a DVD pickup head in future HS-AFM technology.
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Affiliation(s)
- H-S Liao
- Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan
| | - Y-H Chen
- Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan
| | - R-F Ding
- Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan
| | - H-F Huang
- Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan
| | - W-M Wang
- Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan
| | - E-T Hwu
- Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan
| | - K-Y Huang
- Department of Mechanical Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - C-S Chang
- Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan
| | - I-S Hwang
- Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan
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175
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Stylianou A, Yova D, Alexandratou E. Investigation of the influence of UV irradiation on collagen thin films by AFM imaging. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2014; 45:455-68. [PMID: 25491851 DOI: 10.1016/j.msec.2014.09.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 08/21/2014] [Accepted: 09/08/2014] [Indexed: 01/06/2023]
Abstract
Collagen is the major fibrous extracellular matrix protein and due to its unique properties, it has been widely used as biomaterial, scaffold and cell-substrate. The aim of the paper was to use Atomic Force Microscopy (AFM) in order to investigate well-characterized collagen thin films after ultraviolet light (UV) irradiation. The films were also used as in vitro culturing substrates in order to investigate the UV-induced alterations to fibroblasts. A special attention was given in the alteration on collagen D-periodicity. For short irradiation times, spectroscopy (fluorescence/absorption) studies demonstrated that photodegradation took place and AFM imaging showed alterations in surface roughness. Also, it was highlighted that UV-irradiation had different effects when it was applied on collagen solution than on films. Concerning fibroblast culturing, it was shown that fibroblast behavior was affected after UV irradiation of both collagen solution and films. Furthermore, after a long irradiation time, collagen fibrils were deformed revealing that collagen fibrils are consisting of multiple shells and D-periodicity occurred on both outer and inner shells. The clarification of the effects of UV light on collagen and the induced modifications of cell behavior on UV-irradiated collagen-based surfaces will contribute to the better understanding of cell-matrix interactions in the nanoscale and will assist in the appropriate use of UV light for sterilizing and photo-cross-linking applications.
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Affiliation(s)
- Andreas Stylianou
- Biomedical Optics and Applied Biophysics Laboratory, Division of Electromagnetics, Electrooptics and Electronic Materials, School of Electrical and Computer Engineering, National Technical University of Athens, 9 Iroon Polytechniou, Athens 15780 Greece.
| | - Dido Yova
- Biomedical Optics and Applied Biophysics Laboratory, Division of Electromagnetics, Electrooptics and Electronic Materials, School of Electrical and Computer Engineering, National Technical University of Athens, 9 Iroon Polytechniou, Athens 15780 Greece
| | - Eleni Alexandratou
- Biomedical Optics and Applied Biophysics Laboratory, Division of Electromagnetics, Electrooptics and Electronic Materials, School of Electrical and Computer Engineering, National Technical University of Athens, 9 Iroon Polytechniou, Athens 15780 Greece
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176
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Malt LM, Perrett CA, Humphrey S, Jepson MA. Applications of microscopy in Salmonella research. Methods Mol Biol 2014; 1225:165-98. [PMID: 25253256 DOI: 10.1007/978-1-4939-1625-2_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Salmonella enterica is a Gram-negative enteropathogen that can cause localized infections, typically resulting in gastroenteritis, or systemic infection, e.g., typhoid fever, in humans and many other animals. Understanding the mechanisms by which Salmonella induces disease has been the focus of intensive research. This has revealed that Salmonella invasion requires dynamic cross-talk between the microbe and host cells, in which bacterial adherence rapidly leads to a complex sequence of cellular responses initiated by proteins translocated into the host cell by a type 3 secretion system. Once these Salmonella-induced responses have resulted in bacterial invasion, proteins translocated by a second type 3 secretion system initiate further modulation of cellular activities to enable survival and replication of the invading pathogen. Elucidation of the complex and highly dynamic pathogen-host interactions ultimately requires analysis at the level of single cells and single infection events. To achieve this goal, researchers have applied a diverse range of microscopy techniques to analyze Salmonella infection in models ranging from whole animal to isolated cells and simple eukaryotic organisms. For example, electron microscopy and high-resolution light microscopy techniques such as confocal microscopy can reveal the precise location of Salmonella and its relationship to cellular components. Widefield light microscopy is a simpler approach with which to study the interaction of bacteria with host cells and often has advantages for live cell imaging, enabling detailed analysis of the dynamics of infection and cellular responses. Here we review the use of imaging techniques in Salmonella research and compare the capabilities of different classes of microscope to address specific types of research question. We also provide protocols and notes on some microscopy techniques used routinely in our own research.
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Affiliation(s)
- Layla M Malt
- Department of Biochemistry, School of Medical Sciences, University of Bristol, Tyndall Avenue, Bristol, BS8 1TD, UK
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177
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Benech JC, Benech N, Zambrana AI, Rauschert I, Bervejillo V, Oddone N, Damián JP. Diabetes increases stiffness of live cardiomyocytes measured by atomic force microscopy nanoindentation. Am J Physiol Cell Physiol 2014; 307:C910-9. [PMID: 25163520 DOI: 10.1152/ajpcell.00192.2013] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Stiffness of live cardiomyocytes isolated from control and diabetic mice was measured using the atomic force microscopy nanoindentation method. Type 1 diabetes was induced in mice by streptozotocin administration. Histological images of myocardium from mice that were diabetic for 3 mo showed disorderly lineup of myocardial cells, irregularly sized cell nuclei, and fragmented and disordered myocardial fibers with interstitial collagen accumulation. Phalloidin-stained cardiomyocytes isolated from diabetic mice showed altered (i.e., more irregular and diffuse) actin filament organization compared with cardiomyocytes from control mice. Sarco/endoplasmic reticulum Ca(2+)-ATPase (SERCA2a) pump expression was reduced in homogenates obtained from the left ventricle of diabetic animals compared with age-matched controls. The apparent elastic modulus (AEM) for live control or diabetic isolated cardiomyocytes was measured using the atomic force microscopy nanoindentation method in Tyrode buffer solution containing 1.8 mM Ca(2+) and 5.4 mM KCl (physiological condition), 100 nM Ca(2+) and 5.4 mM KCl (low extracellular Ca(2+) condition), or 1.8 mM Ca(2+) and 140 mM KCl (contraction condition). In the physiological condition, the mean AEM was 112% higher for live diabetic than control isolated cardiomyocytes (91 ± 14 vs. 43 ± 7 kPa). The AEM was also significantly higher in diabetic than control cardiomyocytes in the low extracellular Ca(2+) and contraction conditions. These findings suggest that the material properties of live cardiomyocytes were affected by diabetes, resulting in stiffer cells, which very likely contribute to high diastolic LV stiffness, which has been observed in vivo in some diabetes mellitus patients.
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Affiliation(s)
- Juan C Benech
- Laboratorio de Señalización Celular y Nanobiología, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay;
| | - Nicolás Benech
- Instituto de Física, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay; and
| | - Ana I Zambrana
- Laboratorio de Señalización Celular y Nanobiología, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - Inés Rauschert
- Laboratorio de Señalización Celular y Nanobiología, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - Verónica Bervejillo
- Laboratorio de Señalización Celular y Nanobiología, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - Natalia Oddone
- Laboratorio de Señalización Celular y Nanobiología, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - Juan P Damián
- Laboratorio de Señalización Celular y Nanobiología, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay; Departamento de Biología Molecular y Celular, Facultad de Veterinaria, Universidad de la República, Montevideo, Uruguay
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178
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Yallapu MM, Katti KS, Katti DR, Mishra SR, Khan S, Jaggi M, Chauhan SC. The roles of cellular nanomechanics in cancer. Med Res Rev 2014; 35:198-223. [PMID: 25137233 DOI: 10.1002/med.21329] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The biomechanical properties of cells and tissues may be instrumental in increasing our understanding of cellular behavior and cellular manifestations of diseases such as cancer. Nanomechanical properties can offer clinical translation of therapies beyond what are currently employed. Nanomechanical properties, often measured by nanoindentation methods using atomic force microscopy, may identify morphological variations, cellular binding forces, and surface adhesion behaviors that efficiently differentiate normal cells and cancer cells. The aim of this review is to examine current research involving the general use of atomic force microscopy/nanoindentation in measuring cellular nanomechanics; various factors and instrumental conditions that influence the nanomechanical properties of cells; and implementation of nanoindentation methods to distinguish cancer cells from normal cells or tissues. Applying these fundamental nanomechanical properties to current discoveries in clinical treatment may result in greater efficiency in diagnosis, treatment, and prevention of cancer, which ultimately can change the lives of patients.
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Affiliation(s)
- Murali M Yallapu
- Department of Pharmaceutical Sciences and Center for Cancer Research, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee, 38163
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179
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Li M, Liu L, Xi N, Wang Y. Research progress in quantifying the mechanical properties of single living cells using atomic force microscopy. ACTA ACUST UNITED AC 2014. [DOI: 10.1007/s11434-014-0581-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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180
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Gold nanoparticles inhibit VEGF165-induced migration and tube formation of endothelial cells via the Akt pathway. BIOMED RESEARCH INTERNATIONAL 2014; 2014:418624. [PMID: 24987682 PMCID: PMC4058682 DOI: 10.1155/2014/418624] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 04/27/2014] [Accepted: 04/28/2014] [Indexed: 02/07/2023]
Abstract
The early stages of angiogenesis can be divided into three steps: endothelial cell proliferation, migration, and tube formation. Vascular endothelial growth factor (VEGF) is considered the most important proangiogenic factor; in particular, VEGF165 plays a critical role in angiogenesis. Here, we evaluated whether gold nanoparticles (AuNPs) could inhibit the VEGF165-induced human umbilical vein endothelial cell (HUVEC) migration and tube formation. AuNPs and VEGF165 were coincubated overnight at 4°C, after which the effects on cell migration and tube formation were assessed. Cell migration was assessed using a modified wound-healing assay and a transwell chamber assay; tube formation was assessed using a capillary-like tube formation assay and a chick chorioallantoic membrane (CAM) assay. We additionally detected the cell surface morphology and ultrastructure using atomic force microscopy (AFM). Furthermore, Akt phosphorylation downstream of VEGFR-2/PI3K in HUVECs was determined in a Western blot analysis. Our study demonstrated that AuNPs significantly inhibited VEGF165-induced HUVEC migration and tube formation by affecting the cell surface ultrastructure, cytoskeleton and might have inhibited angiogenesis via the Akt pathway.
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181
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Bull MS, Sullan RMA, Li H, Perkins TT. Improved single molecule force spectroscopy using micromachined cantilevers. ACS NANO 2014; 8:4984-95. [PMID: 24670198 DOI: 10.1021/nn5010588] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Enhancing the short-term force precision of atomic force microscopy (AFM) while maintaining excellent long-term force stability would result in improved performance across multiple AFM modalities, including single molecule force spectroscopy (SMFS). SMFS is a powerful method to probe the nanometer-scale dynamics and energetics of biomolecules (DNA, RNA, and proteins). The folding and unfolding rates of such macromolecules are sensitive to sub-pN changes in force. Recently, we demonstrated sub-pN stability over a broad bandwidth (Δf = 0.01-16 Hz) by removing the gold coating from a 100 μm long cantilever. However, this stability came at the cost of increased short-term force noise, decreased temporal response, and poor sensitivity. Here, we avoided these compromises while retaining excellent force stability by modifying a short (L = 40 μm) cantilever with a focused ion beam. Our process led to a ∼10-fold reduction in both a cantilever's stiffness and its hydrodynamic drag near a surface. We also preserved the benefits of a highly reflective cantilever while mitigating gold-coating induced long-term drift. As a result, we extended AFM's sub-pN bandwidth by a factor of ∼50 to span five decades of bandwidth (Δf ≈ 0.01-1000 Hz). Measurements of mechanically stretching individual proteins showed improved force precision coupled with state-of-the-art force stability and no significant loss in temporal resolution compared to the stiffer, unmodified cantilever. Finally, these cantilevers were robust and were reused for SFMS over multiple days. Hence, we expect these responsive, yet stable, cantilevers to broadly benefit diverse AFM-based studies.
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Affiliation(s)
- Matthew S Bull
- JILA, National Institute of Standards and Technology and University of Colorado , Boulder, Colorado 80309, United States
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182
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Lamprecht C, Hinterdorfer P, Ebner A. Applications of biosensing atomic force microscopy in monitoring drug and nanoparticle delivery. Expert Opin Drug Deliv 2014; 11:1237-53. [PMID: 24809228 DOI: 10.1517/17425247.2014.917078] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
INTRODUCTION The therapeutic effects of medicinal drugs not only depend on their properties, but also on effective transport to the target receptor. Here we highlight recent developments in this discipline and show applications of atomic force microscopy (AFM) that enable us to track the effects of drugs and the effectiveness of nanoparticle delivery at the single molecule level. AREAS COVERED Physiological AFM imaging enables visualization of topographical changes to cells as a result of drug exposure and allows observation of cellular responses that yield morphological changes. When we upgrade the regular measuring tip to a molecular biosensor, it enables investigation of functional changes at the molecular level via single molecule force spectroscopy. EXPERT OPINION Biosensing AFM techniques have generated powerful tools to monitor drug delivery in (living) cells. While technical developments in actual AFM methods have simplified measurements at relevant physiological conditions, understanding both the biological and technical background is still a crucial factor. However, due to its potential impact, we expect the number of application-based biosensing AFM techniques to further increase in the near future.
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Affiliation(s)
- Constanze Lamprecht
- University of Kiel, Institute of Materials Science Biocompatible Nanomaterials , Kaiserstr.2, 24143 Kiel , Germany
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183
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Ultrastable atomic force microscopy: improved force and positional stability. FEBS Lett 2014; 588:3621-30. [PMID: 24801176 DOI: 10.1016/j.febslet.2014.04.033] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 04/18/2014] [Accepted: 04/23/2014] [Indexed: 11/20/2022]
Abstract
Atomic force microscopy (AFM) is an exciting technique for biophysical studies of single molecules, but its usefulness is limited by instrumental drift. We dramatically reduced positional drift by adding two lasers to track and thereby actively stabilize the tip and the surface. These lasers also enabled label-free optical images that were spatially aligned to the tip position. Finally, sub-pN force stability over 100 s was achieved by removing the gold coating from soft cantilevers. These enhancements to AFM instrumentation can immediately benefit research in biophysics and nanoscience.
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184
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An AFM-based pit-measuring method for indirect measurements of cell-surface membrane vesicles. Biochem Biophys Res Commun 2014; 446:375-9. [PMID: 24607905 DOI: 10.1016/j.bbrc.2014.02.114] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Accepted: 02/25/2014] [Indexed: 12/14/2022]
Abstract
Circulating membrane vesicles, which are shed from many cell types, have multiple functions and have been correlated with many diseases. Although circulating membrane vesicles have been extensively characterized, the status of cell-surface membrane vesicles prior to their release is less understood due to the lack of effective measurement methods. Recently, as a powerful, micro- or nano-scale imaging tool, atomic force microscopy (AFM) has been applied in measuring circulating membrane vesicles. However, it seems very difficult for AFM to directly image/identify and measure cell-bound membrane vesicles due to the similarity of surface morphology between membrane vesicles and cell surfaces. Therefore, until now no AFM studies on cell-surface membrane vesicles have been reported. In this study, we found that air drying can induce the transformation of most cell-surface membrane vesicles into pits that are more readily detectable by AFM. Based on this, we developed an AFM-based pit-measuring method and, for the first time, used AFM to indirectly measure cell-surface membrane vesicles on cultured endothelial cells. Using this approach, we observed and quantitatively measured at least two populations of cell-surface membrane vesicles, a nanoscale population (<500 nm in diameter peaking at ∼250 nm) and a microscale population (from 500 nm to ∼2 μm peaking at ∼0.8 μm), whereas confocal microscopy only detected the microscale population. The AFM-based pit-measuring method is potentially useful for studying cell-surface membrane vesicles and for investigating the mechanisms of membrane vesicle formation/release.
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185
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Xing Y, Li A, Felker DL, Burggraf LW. Nanoscale structural and mechanical analysis of Bacillus anthracis spores inactivated with rapid dry heating. Appl Environ Microbiol 2014; 80:1739-49. [PMID: 24375142 PMCID: PMC3957622 DOI: 10.1128/aem.03483-13] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 12/21/2013] [Indexed: 11/20/2022] Open
Abstract
Effective killing of Bacillus anthracis spores is of paramount importance to antibioterrorism, food safety, environmental protection, and the medical device industry. Thus, a deeper understanding of the mechanisms of spore resistance and inactivation is highly desired for developing new strategies or improving the known methods for spore destruction. Previous studies have shown that spore inactivation mechanisms differ considerably depending upon the killing agents, such as heat (wet heat, dry heat), UV, ionizing radiation, and chemicals. It is believed that wet heat kills spores by inactivating critical enzymes, while dry heat kills spores by damaging their DNA. Many studies have focused on the biochemical aspects of spore inactivation by dry heat; few have investigated structural damages and changes in spore mechanical properties. In this study, we have inactivated Bacillus anthracis spores with rapid dry heating and performed nanoscale topographical and mechanical analysis of inactivated spores using atomic force microscopy (AFM). Our results revealed significant changes in spore morphology and nanomechanical properties after heat inactivation. In addition, we also found that these changes were different under different heating conditions that produced similar inactivation probabilities (high temperature for short exposure time versus low temperature for long exposure time). We attributed the differences to the differential thermal and mechanical stresses in the spore. The buildup of internal thermal and mechanical stresses may become prominent only in ultrafast, high-temperature heat inactivation when the experimental timescale is too short for heat-generated vapor to efficiently escape from the spore. Our results thus provide direct, visual evidences of the importance of thermal stresses and heat and mass transfer to spore inactivation by very rapid dry heating.
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Affiliation(s)
- Yun Xing
- Department of Engineering Physics, Air Force Institute of Technology, Wright-Patterson Air Force Base (WPAFB), Dayton, Ohio, USA
- Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, Tennessee, USA
| | - Alex Li
- Department of Engineering Physics, Air Force Institute of Technology, Wright-Patterson Air Force Base (WPAFB), Dayton, Ohio, USA
| | - Daniel L. Felker
- Department of Systems Engineering & Management, Air Force Institute of Technology, WPAFB, Dayton, Ohio, USA
| | - Larry W. Burggraf
- Department of Engineering Physics, Air Force Institute of Technology, Wright-Patterson Air Force Base (WPAFB), Dayton, Ohio, USA
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186
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Longo G, Kasas S. Effects of antibacterial agents and drugs monitored by atomic force microscopy. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2014; 6:230-44. [PMID: 24616433 DOI: 10.1002/wnan.1258] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 01/06/2014] [Accepted: 01/13/2014] [Indexed: 11/07/2022]
Abstract
Originally invented for topographic imaging, atomic force microscopy (AFM) has evolved into a multifunctional biological toolkit, enabling to measure structural and functional details of cells and molecules. Its versatility and the large scope of information it can yield make it an invaluable tool in any biologically oriented laboratory, where researchers need to perform characterizations of living samples as well as single molecules in quasi-physiological conditions and with nanoscale resolution. In the last 20 years, AFM has revolutionized the characterization of microbial cells by allowing a better understanding of their cell wall and of the mechanism of action of drugs and by becoming itself a powerful diagnostic tool to study bacteria. Indeed, AFM is much more than a high-resolution microscopy technique. It can reconstruct force maps that can be used to explore the nanomechanical properties of microorganisms and probe at the same time the morphological and mechanical modifications induced by external stimuli. Furthermore it can be used to map chemical species or specific receptors with nanometric resolution directly on the membranes of living organisms. In summary, AFM offers new capabilities and a more in-depth insight in the structure and mechanics of biological specimens with an unrivaled spatial and force resolution. Its application to the study of bacteria is extremely significant since it has already delivered important information on the metabolism of these small microorganisms and, through new and exciting technical developments, will shed more light on the real-time interaction of antimicrobial agents and bacteria.
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Affiliation(s)
- Giovanni Longo
- Ecole Polytechnique Fédérale de Lausanne, LPMV, Lausanne, Switzerland; Istituto Superiore di Sanità, Rome, Italy
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187
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Wang C, Yadavalli VK. Investigating biomolecular recognition at the cell surface using atomic force microscopy. Micron 2014; 60:5-17. [PMID: 24602267 DOI: 10.1016/j.micron.2014.01.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Revised: 01/07/2014] [Accepted: 01/07/2014] [Indexed: 10/25/2022]
Abstract
Probing the interaction forces that drive biomolecular recognition on cell surfaces is essential for understanding diverse biological processes. Force spectroscopy has been a widely used dynamic analytical technique, allowing measurement of such interactions at the molecular and cellular level. The capabilities of working under near physiological environments, combined with excellent force and lateral resolution make atomic force microscopy (AFM)-based force spectroscopy a powerful approach to measure biomolecular interaction forces not only on non-biological substrates, but also on soft, dynamic cell surfaces. Over the last few years, AFM-based force spectroscopy has provided biophysical insight into how biomolecules on cell surfaces interact with each other and induce relevant biological processes. In this review, we focus on describing the technique of force spectroscopy using the AFM, specifically in the context of probing cell surfaces. We summarize recent progress in understanding the recognition and interactions between macromolecules that may be found at cell surfaces from a force spectroscopy perspective. We further discuss the challenges and future prospects of the application of this versatile technique.
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Affiliation(s)
- Congzhou Wang
- Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA 23284, USA
| | - Vamsi K Yadavalli
- Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA 23284, USA.
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188
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Sharma S, Das K, Woo J, Gimzewski JK. Nanofilaments on glioblastoma exosomes revealed by peak force microscopy. J R Soc Interface 2014; 11:20131150. [PMID: 24402921 DOI: 10.1098/rsif.2013.1150] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Exosomes are sub-100 nm extracellular vesicles secreted by normal and cancer cells. We present a high-resolution structure of previously unidentified nanofilaments on glioblastoma-derived exosomes, using nanoscale peak force imaging. These stiff, adhesive, trypsin- and RNAse-resistant surface nanofilaments add a new dimension to the current structural knowledge of exosome-mediated intercellular communication.
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Affiliation(s)
- Shivani Sharma
- Department of Chemistry and Biochemistry, University of California, , Los Angeles, CA 90095, USA
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189
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Günther TJ, Suhr M, Raff J, Pollmann K. Immobilization of microorganisms for AFM studies in liquids. RSC Adv 2014. [DOI: 10.1039/c4ra03874f] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Reproducible immobilization method even for living eukaryotes and prokaryotes on polyelectrolyte coated surfaces for high resolution AFM imaging in liquids.
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Affiliation(s)
- Tobias J. Günther
- Helmholtz-Zentrum Dresden-Rossendorf
- Institute for Resource Ecology and Helmholtz Institute Freiberg for Resource Technology
- 01328 Dresden, Germany
| | - Matthias Suhr
- Helmholtz-Zentrum Dresden-Rossendorf
- Institute of Resource Ecology
- 01328 Dresden, Germany
| | - Johannes Raff
- Helmholtz-Zentrum Dresden-Rossendorf
- Institute for Resource Ecology and Helmholtz Institute Freiberg for Resource Technology
- 01328 Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf
- Institute of Resource Ecology
| | - Katrin Pollmann
- Helmholtz-Zentrum Dresden-Rossendorf
- Institute for Resource Ecology and Helmholtz Institute Freiberg for Resource Technology
- 01328 Dresden, Germany
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190
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Tesson B, Charrier B. Brown algal morphogenesis: atomic force microscopy as a tool to study the role of mechanical forces. FRONTIERS IN PLANT SCIENCE 2014; 5:471. [PMID: 25278949 PMCID: PMC4166355 DOI: 10.3389/fpls.2014.00471] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2014] [Accepted: 08/28/2014] [Indexed: 05/17/2023]
Abstract
Over the last few years, a growing interest has been directed toward the use of macroalgae as a source of energy, food and molecules for the cosmetic and pharmaceutical industries. Besides this, macroalgal development remains poorly understood compared to other multicellular organisms. Brown algae (Phaeophyceae) form a monophyletic lineage of usually large multicellular algae which evolved independently from land plants. In their environment, they are subjected to strong mechanical forces (current, waves, and tide), in response to which they modify rapidly and reversibly their morphology. Because of their specific cellular features (cell wall composition, cytoskeleton organization), deciphering how they cope with these forces might help discover new control mechanisms of cell wall softening and cellulose synthesis. Despite the current scarcity in knowledge on brown algal cell wall dynamics and protein composition, we will illustrate, in the light of methods adapted to Ectocarpus siliculosus, to what extent atomic force microscopy can contribute to advance this field of investigation.
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Affiliation(s)
- Benoit Tesson
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San DiegoLa Jolla, CA, USA
- *Correspondence: Benoit Tesson, Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0202, USA e-mail:
| | - Bénédicte Charrier
- Centre National de la Recherche Scientifique-Unités Mixtes de Recherche 8227 Integrative Biology of Marine Models, Station Biologique de RoscoffRoscoff, France
- Sorbonne Universités, Université Pierre-et-Marie-Curie, Unités Mixtes de Recherche 8227 Integrative Biology of Marine ModelsRoscoff, France
- Bénédicte Charrier, CNRS, UMR 8227 Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688 Roscoff cedex, France e-mail:
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191
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Single-cell force spectroscopy of probiotic bacteria. Biophys J 2013; 104:1886-92. [PMID: 23663831 DOI: 10.1016/j.bpj.2013.03.046] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Revised: 03/26/2013] [Accepted: 03/28/2013] [Indexed: 11/22/2022] Open
Abstract
Single-cell force spectroscopy is a powerful atomic force microscopy modality in which a single living cell is attached to the atomic force microscopy cantilever to quantify the forces that drive cell-cell and cell-substrate interactions. Although various single-cell force spectroscopy protocols are well established for animal cells, application of the method to individual bacterial cells remains challenging, mainly owing to the lack of appropriate methods for the controlled attachment of single live cells on cantilevers. We present a nondestructive protocol for single-bacterial cell force spectroscopy, which combines the use of colloidal probe cantilevers and of a bioinspired polydopamine wet adhesive. Living cells from the probiotic species Lactobacillus plantarum are picked up with a polydopamine-coated colloidal probe, enabling us to quantify the adhesion forces between single bacteria and biotic (lectin monolayer) or abiotic (hydrophobic monolayer) surfaces. These minimally invasive single-cell experiments provide novel, to our knowledge, insight into the specific and nonspecific forces driving the adhesion of L. plantarum, and represent a generic platform for studying the molecular mechanisms of cell adhesion in probiotic and pathogenic bacteria.
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192
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Mathé C, Devineau S, Aude JC, Lagniel G, Chédin S, Legros V, Mathon MH, Renault JP, Pin S, Boulard Y, Labarre J. Structural determinants for protein adsorption/non-adsorption to silica surface. PLoS One 2013; 8:e81346. [PMID: 24282583 PMCID: PMC3839912 DOI: 10.1371/journal.pone.0081346] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Accepted: 10/11/2013] [Indexed: 11/18/2022] Open
Abstract
The understanding of the mechanisms involved in the interaction of proteins with inorganic surfaces is of major interest in both fundamental research and applications such as nanotechnology. However, despite intense research, the mechanisms and the structural determinants of protein/surface interactions are still unclear. We developed a strategy consisting in identifying, in a mixture of hundreds of soluble proteins, those proteins that are adsorbed on the surface and those that are not. If the two protein subsets are large enough, their statistical comparative analysis must reveal the physicochemical determinants relevant for adsorption versus non-adsorption. This methodology was tested with silica nanoparticles. We found that the adsorbed proteins contain a higher number of charged amino acids, particularly arginine, which is consistent with involvement of this basic amino acid in electrostatic interactions with silica. The analysis also identified a marked bias toward low aromatic amino acid content (phenylalanine, tryptophan, tyrosine and histidine) in adsorbed proteins. Structural analyses and molecular dynamics simulations of proteins from the two groups indicate that non-adsorbed proteins have twice as many π-π interactions and higher structural rigidity. The data are consistent with the notion that adsorption is correlated with the flexibility of the protein and with its ability to spread on the surface. Our findings led us to propose a refined model of protein adsorption.
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Affiliation(s)
- Christelle Mathé
- Laboratoire de Radiolyse, SIS2M, IRAMIS and UMR3299 CEA-CNRS, Saclay, France
- Service de Biologie Intégrative et Génétique Moléculaire, iBiTec-S, FRE3377 CEA-CNRS-Université Paris-Sud, Saclay, France
- Laboratoire Analyse et Modélisation pour la Biologie et l'Environnement, UMR 8587 CNRS-Université Evry Val d'Essonne, Evry, France
| | - Stéphanie Devineau
- Laboratoire de Radiolyse, SIS2M, IRAMIS and UMR3299 CEA-CNRS, Saclay, France
| | - Jean-Christophe Aude
- Service de Biologie Intégrative et Génétique Moléculaire, iBiTec-S, FRE3377 CEA-CNRS-Université Paris-Sud, Saclay, France
| | - Gilles Lagniel
- Service de Biologie Intégrative et Génétique Moléculaire, iBiTec-S, FRE3377 CEA-CNRS-Université Paris-Sud, Saclay, France
| | - Stéphane Chédin
- Service de Biologie Intégrative et Génétique Moléculaire, iBiTec-S, FRE3377 CEA-CNRS-Université Paris-Sud, Saclay, France
| | - Véronique Legros
- Laboratoire Analyse et Modélisation pour la Biologie et l'Environnement, UMR 8587 CNRS-Université Evry Val d'Essonne, Evry, France
| | | | | | - Serge Pin
- Laboratoire de Radiolyse, SIS2M, IRAMIS and UMR3299 CEA-CNRS, Saclay, France
| | - Yves Boulard
- Service de Biologie Intégrative et Génétique Moléculaire, iBiTec-S, FRE3377 CEA-CNRS-Université Paris-Sud, Saclay, France
- Laboratoire Structure et Dynamique par Résonance Magnétique, SIS2M, IRAMIS and UMR3299 CEA-CNRS, Saclay, France
| | - Jean Labarre
- Service de Biologie Intégrative et Génétique Moléculaire, iBiTec-S, FRE3377 CEA-CNRS-Université Paris-Sud, Saclay, France
- * E-mail:
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193
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Peñuela L, Wolf F, Raiteri R, Wendt D, Martin I, Barbero A. Atomic force microscopy to investigate spatial patterns of response to interleukin-1beta in engineered cartilage tissue elasticity. J Biomech 2013; 47:2157-64. [PMID: 24290139 DOI: 10.1016/j.jbiomech.2013.10.056] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 10/21/2013] [Accepted: 10/26/2013] [Indexed: 01/15/2023]
Abstract
Atomic force microscopy (AFM) has been proposed as a tool to evaluate the structural and mechanical properties of cartilage tissue. Here, we aimed at assessing whether AFM can be employed to quantify spatially resolved elastic response of tissue engineered cartilage (TEC) to short exposure to IL-1β, thus mimicking the initially inflammatory implantation site. TEC generated by 14 days of pellet-culture of expanded human chondrocytes was left untreated (ctr) or exposed to IL-1β for 3 days. TEC pellets were then cut in halves that were glued on a Petri dish. Profiles of elasticity were obtained by sampling with a nanometer sized, pyramidal indenting tip, with 200µm step resolution, the freshly exposed surfaces along selected directions. Replicate TECs were analyzed biochemically and histologically. GAG contents and elasticity of pellets decreased (1.4- and 2.6-fold, respectively, p<0.05) following IL-1β stimulation. Tissue quality was evaluated by scoring histological pictures taken at 200μm intervals, using the Bern-score grading system. At each distance, scores of ctr TEC were higher than those IL-1β treated, with the largest differences between the two groups observed in the central regions. Consistent with the histological results, elasticity of IL-1β-treated TEC was lower than in ctr pellets (up to 3.4-fold at 200μm from the center). IL-1β treated but not ctr TEC was intensely stained for MMP-13 and DIPEN (cryptic fragment of aggrecan) especially in the central regions. The findings indicate the potential of AFM to investigate structure/function relationships in TEC and to perform tests aimed at predicting the functionality of TEC upon implantation.
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Affiliation(s)
- Leonardo Peñuela
- Department of Informatics, Bioengineering, Robotics, and System Engineering, University of Genova, Genova, Italy
| | - Francine Wolf
- Deparments of Surgery and of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Roberto Raiteri
- Department of Informatics, Bioengineering, Robotics, and System Engineering, University of Genova, Genova, Italy
| | - David Wendt
- Deparments of Surgery and of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Ivan Martin
- Deparments of Surgery and of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland.
| | - Andrea Barbero
- Deparments of Surgery and of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland
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194
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Micropattern of antibodies imaged by shear force microscopy: comparison between classical and jumping modes. Ultramicroscopy 2013; 136:176-84. [PMID: 24184681 DOI: 10.1016/j.ultramic.2013.09.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 09/10/2013] [Accepted: 09/16/2013] [Indexed: 12/21/2022]
Abstract
Quartz tuning fork devices are increasingly being used as nanosensors in Scanning Probe Microscopy. They offer some benefits with respect to standard microfabricated cantilevers in certain experimental setups including the study of biomolecules under physiological conditions. In this work, we compare three different working modes for imaging micropatterned antibodies with quartz tuning fork sensors: apart from the classical amplitude and frequency modulation strategies, for first time the jumping mode is implemented using tuning forks. Our results show that the molecules suffer less degradation when working in the jumping mode, due to the reduction of the interaction forces.
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195
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Li M, Xiao X, Liu L, Xi N, Wang Y, Dong Z, Zhang W. Nanoscale mapping and organization analysis of target proteins on cancer cells from B-cell lymphoma patients. Exp Cell Res 2013; 319:2812-21. [DOI: 10.1016/j.yexcr.2013.07.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 07/21/2013] [Accepted: 07/23/2013] [Indexed: 01/20/2023]
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196
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Al-Rekabi Z, Pelling AE. Cross talk between matrix elasticity and mechanical force regulates myoblast traction dynamics. Phys Biol 2013; 10:066003. [PMID: 24164970 DOI: 10.1088/1478-3975/10/6/066003] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Growing evidence suggests that critical cellular processes are profoundly influenced by the cross talk between extracellular nanomechanical forces and the material properties of the cellular microenvironment. Although many studies have examined either the effect of nanomechanical forces or the material properties of the microenvironment on biological processes, few have investigated the influence of both. Here, we performed simultaneous atomic force microscopy and traction force microscopy to demonstrate that muscle precursor cells (myoblasts) rapidly generate a significant increase in traction when stimulated with a local 10 nN force. Cells were cultured and nanomechanically stimulated on hydrogel substrates with controllable local elastic moduli varying from ~16-89 kPa, as confirmed with atomic force microscopy. Importantly, cellular traction dynamics in response to nanomechanical stimulation only occurred on substrates that were similar to the elasticity of working muscle tissue (~64-89 kPa) as opposed to substrates mimicking resting tissue (~16-51 kPa). The traction response was also transient, occurring within 30 s, and dissipating by 60 s, during constant nanomechanical stimulation. The observed biophysical dynamics are very much dependent on rho-kinase and myosin-II activity and likely contribute to the physiology of these cells. Our results demonstrate the fundamental ability of cells to integrate nanoscale information in the cellular microenvironment, such as nanomechanical forces and substrate mechanics, during the process of mechanotransduction.
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Affiliation(s)
- Zeinab Al-Rekabi
- Department of Physics, MacDonald Hall, 150 Louis Pasteur, University of Ottawa, Ottawa, ON K1N 6N5, Canada
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197
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Francois JM, Formosa C, Schiavone M, Pillet F, Martin-Yken H, Dague E. Use of atomic force microscopy (AFM) to explore cell wall properties and response to stress in the yeast Saccharomyces cerevisiae. Curr Genet 2013; 59:187-96. [PMID: 24071902 DOI: 10.1007/s00294-013-0411-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 09/12/2013] [Accepted: 09/18/2013] [Indexed: 11/30/2022]
Abstract
Over the past 20 years, the yeast cell wall has been thoroughly investigated by genetic and biochemical methods, leading to remarkable advances in the understanding of its biogenesis and molecular architecture as well as to the mechanisms by which this organelle is remodeled in response to environmental stresses. Being a dynamic structure that constitutes the frontier between the cell interior and its immediate surroundings, imaging cell surface, measuring mechanical properties of cell wall or probing cell surface proteins for localization or interaction with external biomolecules are among the most burning questions that biologists wished to address in order to better understand the structure-function relationships of yeast cell wall in adhesion, flocculation, aggregation, biofilm formation, interaction with antifungal drugs or toxins, as well as response to environmental stresses, such as temperature changes, osmotic pressure, shearing stress, etc. The atomic force microscopy (AFM) is nowadays the most qualified and developed technique that offers the possibilities to address these questions since it allows working directly on living cells to explore and manipulate cell surface properties at nanometer resolution and to analyze cell wall proteins at the single molecule level. In this minireview, we will summarize the most recent contributions made by AFM in the analysis of the biomechanical and biochemical properties of the yeast cell wall and illustrate the power of this tool to unravel unexpected effects caused by environmental stresses and antifungal agents on the surface of living yeast cells.
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Affiliation(s)
- Jean Marie Francois
- Université de Toulouse, INSA, UPS, INP, 135 avenue de Rangueil, 31077, Toulouse, France,
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198
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Hardij J, Cecchet F, Berquand A, Gheldof D, Chatelain C, Mullier F, Chatelain B, Dogné JM. Characterisation of tissue factor-bearing extracellular vesicles with AFM: comparison of air-tapping-mode AFM and liquid Peak Force AFM. J Extracell Vesicles 2013; 2:21045. [PMID: 24223257 PMCID: PMC3823107 DOI: 10.3402/jev.v2i0.21045] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 07/02/2013] [Accepted: 07/08/2013] [Indexed: 12/31/2022] Open
Abstract
Introduction Extracellular vesicles (EVs) are shed from cells and carry markers of the parent cells. Vesicles derived from cancer cells reach the bloodstream and locally influence important physiological processes. It has been previously shown that procoagulant vesicles are circulating in patients’ fluids. These EVs are therefore considered as promising biomarkers for the thrombotic risk. Because of their small size, classical methods such as flow cytometry suffer from limitation for their characterisation. Atomic force microscopy (AFM) has been proposed as a promising complementary method for the characterisation of EVs. Objectives The objectives of this study are: (a) to develop and validate AFM with specific antibodies (anti-TF) and (b) to compare air and liquid modes for EVs’ size and number determination as potential biomarkers of the prothrombotic risk. Methods AFM multimode nanoscope III was used for air tapping mode (TM). AFM catalyst was used for liquid Peak Force Tapping (PFT) mode. Vesicles are generated according to Davila et al.'s protocol. Substrates are coated with various concentrations of antibodies, thanks to ethanolamine and glutaraldehyde. Results Vesicles were immobilised on antibody-coated surfaces to select tissue factor (TF)-positive vesicles. The size range of vesicles observed in liquid PFT mode is 6–10 times higher than in air mode. This corresponds to the data found in the literature. Conclusion We recommend liquid PFT mode to analyse vesicles on 5 µg/ml antibody-coated substrates.
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Affiliation(s)
- Julie Hardij
- Department of Pharmacy, NARILIS, Namur Thrombosis and Hemostasis Center (NTHC), University of Namur, Namur, Belgium
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199
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Atomic force microscopy imaging of live mammalian cells. SCIENCE CHINA-LIFE SCIENCES 2013; 56:811-7. [DOI: 10.1007/s11427-013-4532-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 07/15/2013] [Indexed: 12/22/2022]
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200
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Jiang J, Jin H, Liu L, Pi J, Yang F, Cai J. Curcumin disturbed cell-cycle distribution of HepG2 cells via cytoskeletal arrangement. SCANNING 2013; 35:253-260. [PMID: 23070725 DOI: 10.1002/sca.21058] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Revised: 09/05/2012] [Accepted: 09/05/2012] [Indexed: 06/01/2023]
Abstract
Due to its extensive antitumor activity, curcumin has been focused on by more researchers. But, its antiproliferative mechanisms are still unknown. Here we studied the antiproliferative activity of curcumin in human liver cancer HepG2 cells. In order to analyze the cytotoxic activity and anticancer mechanisms of curcumin, we carried out cytotoxicity tests using 3-[4,5-dimethyl-2-thiazolyl]-2,5 diphenyltetrazolium bromide (MTT) assay. The HepG2 cell cycle distribution and the expression of tubulin were detected by flow cytometry. Alterations in morphological and cytoskeletal properties of HepG2 cells were investigated using atomic force microscopy (AFM). Simultaneously, the effects of curcumin on the growth and proliferation of HepG2 cells were also assayed by MTT method. Cells were incubated with different doses of curcumin (0-80 μmol/l) for 24 h, the cell viability decreased from 91.10 ± 3.2% to 10.84 ± 4.0%, and the 50% inhibiting concentration (IC50 ) was 23.15 ± 0.37 μmol/l. Moreover, flow cytometry quantitatively detected that curcumin treatment resulted in a dose-dependent accumulation of HepG2 cells in G2/M phase with concomitant losses from G0/G1 phase, so curcumin caused cell-cycle arrest at G2/M phase. Furthermore, we discovered that curcumin was able to upregulate the expression of tubulin in HepG2 cells. In addition, AFM analysis including cell-membrane structure and cytoskeleton networks is helpful to explain the relationship between the changes of cells and external pharmacologic stimulation.
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Affiliation(s)
- Jinhuan Jiang
- Department of Chemistry, College of Life Science and Technology, Jinan University, Guangzhou, China
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