1
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Nicolella Z, Okamoto Y, Watanabe NM, Thompson GL, Umakoshi H. Significance of in situ quantitative membrane property-morphology relation (QmPMR) analysis. SOFT MATTER 2024; 20:4935-4949. [PMID: 38873752 DOI: 10.1039/d4sm00253a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2024]
Abstract
Deformation of the cell membrane is well understood from the viewpoint of protein interactions and free energy balance. However, the various dynamic properties of the membrane, such as lipid packing and hydrophobicity, and their relationship with cell membrane deformation are unknown. Therefore, the deformation of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and oleic acid (OA) giant unilamellar vesicles (GUVs) was induced by heating and cooling cycles, and time-lapse analysis was conducted based on the membrane hydrophobicity and physical parameters of "single-parent" and "daughter" vesicles. Fluorescence ratiometric analysis by simultaneous dual-wavelength detection revealed the variation of different hydrophilic GUVs and enabled inferences of the "daughter" vesicle composition and the "parent" membrane's local composition during deformation; the "daughter" vesicle composition of OA was lower than that of the "parents", and lateral movement of OA was the primary contributor to the formation of the "daughter" vesicles. Thus, our findings and the newly developed methodology, named in situ quantitative membrane property-morphology relation (QmPMR) analysis, would provide new insights into cell deformation and accelerate research on both deformation and its related events, such as budding and birthing.
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Affiliation(s)
- Zachary Nicolella
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka 560-8531, Japan.
| | - Yukihiro Okamoto
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka 560-8531, Japan.
| | - Nozomi Morishita Watanabe
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka 560-8531, Japan.
| | - Gary Lee Thompson
- Rowan University, Rowan Hall, Room 333 70 Sewell St., Ste. E Glassboro, NJ 08028, USA
| | - Hiroshi Umakoshi
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka 560-8531, Japan.
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2
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Erazo-Oliveras A, Muñoz-Vega M, Salinas ML, Wang X, Chapkin RS. Dysregulation of cellular membrane homeostasis as a crucial modulator of cancer risk. FEBS J 2024; 291:1299-1352. [PMID: 36282100 PMCID: PMC10126207 DOI: 10.1111/febs.16665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 09/09/2022] [Accepted: 10/24/2022] [Indexed: 11/07/2022]
Abstract
Cellular membranes serve as an epicentre combining extracellular and cytosolic components with membranous effectors, which together support numerous fundamental cellular signalling pathways that mediate biological responses. To execute their functions, membrane proteins, lipids and carbohydrates arrange, in a highly coordinated manner, into well-defined assemblies displaying diverse biological and biophysical characteristics that modulate several signalling events. The loss of membrane homeostasis can trigger oncogenic signalling. More recently, it has been documented that select membrane active dietaries (MADs) can reshape biological membranes and subsequently decrease cancer risk. In this review, we emphasize the significance of membrane domain structure, organization and their signalling functionalities as well as how loss of membrane homeostasis can steer aberrant signalling. Moreover, we describe in detail the complexities associated with the examination of these membrane domains and their association with cancer. Finally, we summarize the current literature on MADs and their effects on cellular membranes, including various mechanisms of dietary chemoprevention/interception and the functional links between nutritional bioactives, membrane homeostasis and cancer biology.
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Affiliation(s)
- Alfredo Erazo-Oliveras
- Program in Integrative Nutrition and Complex Diseases; Texas A&M University; College Station, Texas, 77843; USA
- Department of Nutrition; Texas A&M University; College Station, Texas, 77843; USA
| | - Mónica Muñoz-Vega
- Program in Integrative Nutrition and Complex Diseases; Texas A&M University; College Station, Texas, 77843; USA
- Department of Nutrition; Texas A&M University; College Station, Texas, 77843; USA
| | - Michael L. Salinas
- Program in Integrative Nutrition and Complex Diseases; Texas A&M University; College Station, Texas, 77843; USA
- Department of Nutrition; Texas A&M University; College Station, Texas, 77843; USA
| | - Xiaoli Wang
- Program in Integrative Nutrition and Complex Diseases; Texas A&M University; College Station, Texas, 77843; USA
- Department of Nutrition; Texas A&M University; College Station, Texas, 77843; USA
| | - Robert S. Chapkin
- Program in Integrative Nutrition and Complex Diseases; Texas A&M University; College Station, Texas, 77843; USA
- Department of Nutrition; Texas A&M University; College Station, Texas, 77843; USA
- Center for Environmental Health Research; Texas A&M University; College Station, Texas, 77843; USA
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3
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Bacalum M, Radu M, Osella S, Knippenberg S, Ameloot M. Generalized polarization and time-resolved fluorescence provide evidence for different populations of Laurdan in lipid vesicles. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2024; 250:112833. [PMID: 38141326 DOI: 10.1016/j.jphotobiol.2023.112833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 11/29/2023] [Accepted: 12/18/2023] [Indexed: 12/25/2023]
Abstract
The solvatochromic dye Laurdan is widely used in sensing the lipid packing of both model and biological membranes. The fluorescence emission maximum shifts from about 440 nm (blue channel) in condensed membranes (So) to about 490 nm (green channel) in the liquid-crystalline phase (Lα). Although the fluorescence intensity based generalized polarization (GP) is widely used to characterize lipid membranes, the fluorescence lifetime of Laurdan, in the blue and the green channel, is less used for that purpose. Here we explore the correlation between GP and fluorescence lifetimes by spectroscopic measurements on the So and Lα phases of large unilamellar vesicles of DMPC and DPPC. A positive correlation between GP and the lifetimes is observed in each of the optical channels for the two lipid phases. Microfluorimetric determinations on giant unilamellar vesicles of DPPC and DOPC at room temperature are performed under linearly polarized two-photon excitation to disentangle possible subpopulations of Laurdan at a scale below the optical resolution. Fluorescence intensities, GP and fluorescence lifetimes depend on the angle between the orientation of the linear polarization of the excitation light and the local normal to the membrane of the optical cross-section. This angular variation depends on the lipid phase and the emission channel. GP and fluorescence intensities in the blue and green channel in So and in the blue channel in Lα exhibit a minimum near 90o. Surprisingly, the intensity in the green channel in Lα reaches a maximum near 90o. The fluorescence lifetimes in the two optical channels also reach a pronounced minimum near 90o in So and Lα, apart from the lifetime in the blue channel in Lα where the lifetime is short with minimal angular variation. To our knowledge, these experimental observations are the first to demonstrate the existence of a bent conformation of Laurdan in lipid membranes, as previously suggested by molecular dynamics calculations.
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Affiliation(s)
- Mihaela Bacalum
- Department of Life and Environmental Physics, Horia Hulubei National Institute for Physics and Nuclear Engineering, Reactorului, 30, Măgurele 077125, Romania
| | - Mihai Radu
- Department of Life and Environmental Physics, Horia Hulubei National Institute for Physics and Nuclear Engineering, Reactorului, 30, Măgurele 077125, Romania
| | - Silvio Osella
- Chemical and Biological Systems Simulation Lab, Centre of New Technologies, University of Warsaw, Banacha 2C, 02-097 Warsaw, Poland
| | - Stefan Knippenberg
- Biomedical Research Institute, Hasselt University, Agoralaan Bldg. C, 3590 Diepenbeek, Belgium; Theory Lab, Hasselt University, Agoralaan Bldg. D, 3590 Diepenbeek, Belgium
| | - Marcel Ameloot
- Biomedical Research Institute, Hasselt University, Agoralaan Bldg. C, 3590 Diepenbeek, Belgium.
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4
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Mangiarotti A, Siri M, Tam NW, Zhao Z, Malacrida L, Dimova R. Biomolecular condensates modulate membrane lipid packing and hydration. Nat Commun 2023; 14:6081. [PMID: 37770422 PMCID: PMC10539446 DOI: 10.1038/s41467-023-41709-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 09/15/2023] [Indexed: 09/30/2023] Open
Abstract
Membrane wetting by biomolecular condensates recently emerged as a key phenomenon in cell biology, playing an important role in a diverse range of processes across different organisms. However, an understanding of the molecular mechanisms behind condensate formation and interaction with lipid membranes is still missing. To study this, we exploited the properties of the dyes ACDAN and LAURDAN as nano-environmental sensors in combination with phasor analysis of hyperspectral and lifetime imaging microscopy. Using glycinin as a model condensate-forming protein and giant vesicles as model membranes, we obtained vital information on the process of condensate formation and membrane wetting. Our results reveal that glycinin condensates display differences in water dynamics when changing the salinity of the medium as a consequence of rearrangements in the secondary structure of the protein. Remarkably, analysis of membrane-condensates interaction with protein as well as polymer condensates indicated a correlation between increased wetting affinity and enhanced lipid packing. This is demonstrated by a decrease in the dipolar relaxation of water across all membrane-condensate systems, suggesting a general mechanism to tune membrane packing by condensate wetting.
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Affiliation(s)
- Agustín Mangiarotti
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14476, Potsdam, Germany.
| | - Macarena Siri
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14476, Potsdam, Germany
| | - Nicky W Tam
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14476, Potsdam, Germany
| | - Ziliang Zhao
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14476, Potsdam, Germany
- Leibniz Institute of Photonic Technology e.V., Albert-Einstein-Straße 9, 07745, Jena, Germany
- Institute of Applied Optics and Biophysics, Friedrich-Schiller-University Jena, Max-Wien Platz 1, 07743, Jena, Germany
| | - Leonel Malacrida
- Departamento de Fisiopatología, Hospital de Clínicas, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay.
- Advanced Bioimaging Unit, Institut Pasteur of Montevideo and Universidad de la República, Montevideo, Uruguay.
| | - Rumiana Dimova
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14476, Potsdam, Germany.
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5
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Paez-Perez M, Dent MR, Brooks NJ, Kuimova MK. Viscosity-Sensitive Membrane Dyes as Tools To Estimate the Crystalline Structure of Lipid Bilayers. Anal Chem 2023; 95:12006-12014. [PMID: 37526607 PMCID: PMC10433245 DOI: 10.1021/acs.analchem.3c01747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 07/12/2023] [Indexed: 08/02/2023]
Abstract
Lipid membranes are crucial for cellular integrity and regulation, and tight control of their structural and mechanical properties is vital to ensure that they function properly. Fluorescent probes sensitive to the membrane's microenvironment are useful for investigating lipid membrane properties; however, there is currently a lack of quantitative correlation between the exact parameters of lipid organization and a readout from these dyes. Here, we investigate this relationship for "molecular rotors", or microviscosity sensors, by simultaneously measuring their fluorescence lifetime to determine the membrane viscosity, while using X-ray diffraction to determine the membrane's structural properties. Our results reveal a phase-dependent correlation between the membrane's structural parameters and mechanical properties measured by a BODIPY-based molecular rotor, giving excellent predictive power for the structural descriptors of the lipid bilayer. We also demonstrate that differences in membrane thickness between different lipid phases are not a prerequisite for the formation of lipid microdomains and that this requirement can be disrupted by the presence of line-active molecules. Our results underpin the use of membrane-sensitive dyes as reporters of the structure of lipid membranes.
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Affiliation(s)
- Miguel Paez-Perez
- MSRH, Department of Chemistry, Imperial College London, Wood Lane, London W12 0BZ, U.K.
| | - Michael R. Dent
- MSRH, Department of Chemistry, Imperial College London, Wood Lane, London W12 0BZ, U.K.
| | - Nicholas J. Brooks
- MSRH, Department of Chemistry, Imperial College London, Wood Lane, London W12 0BZ, U.K.
| | - Marina K. Kuimova
- MSRH, Department of Chemistry, Imperial College London, Wood Lane, London W12 0BZ, U.K.
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6
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Färber N, Reitler J, Schäfer J, Westerhausen C. Transport Across Cell Membranes is Modulated by Lipid Order. Adv Biol (Weinh) 2023; 7:e2200282. [PMID: 36651118 DOI: 10.1002/adbi.202200282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/13/2022] [Indexed: 01/19/2023]
Abstract
This study measures the uptake of various dyes into HeLa cells and determines simultaneously the degree of membrane lipid chain order on a single cell level by spectral analysis of the membrane-embedded dye Laurdan. First, this study finds that the mean generalized polarization (GP) value of single cells varies within a population in a range that is equivalent to a temperature variation of 9 K. This study exploits this natural variety of membrane order to examine the uptake as a function of GP at constant temperature. It is shown that transport across the cell membrane correlates with the membrane phase state. Specifically, higher membrane transport with increasing lipid chain order is observed. As a result, hypothermal-adapted cells with reduced lipid membrane order show less transport. Environmental factors influence transport as well. While increasing temperature reduces lipid order, it is found that locally high cell densities increase lipid order and in turn lead to increased dye uptake. To demonstrate the physiological relevance, membrane state and transport during an in vitro wound healing process are analyzed. While the uptake within a confluent cell layer is high, it decreases toward the center where the membrane lipid chain order is lowest.
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Affiliation(s)
- Nicolas Färber
- Experimental Physics I, Institute of Physics, University of Augsburg, Universitätsstraße 1, 86159, Augsburg, Germany
- Physiology, Institute of Theoretical Medicine, University of Augsburg, Universitätsstraße 2, 86159, Augsburg, Germany
| | - Jonas Reitler
- Physiology, Institute of Theoretical Medicine, University of Augsburg, Universitätsstraße 2, 86159, Augsburg, Germany
| | - Julian Schäfer
- Physiology, Institute of Theoretical Medicine, University of Augsburg, Universitätsstraße 2, 86159, Augsburg, Germany
| | - Christoph Westerhausen
- Experimental Physics I, Institute of Physics, University of Augsburg, Universitätsstraße 1, 86159, Augsburg, Germany
- Physiology, Institute of Theoretical Medicine, University of Augsburg, Universitätsstraße 2, 86159, Augsburg, Germany
- Center for NanoScience (CeNS), Ludwig-Maximilians-Universität Munich, 80799, Munich, Germany
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7
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Iachina I, Fiutowski J, Rubahn HG, Vollrath F, Brewer JR. Nanoscale imaging of major and minor ampullate silk from the orb-web spider Nephila Madagascariensis. Sci Rep 2023; 13:6695. [PMID: 37095261 PMCID: PMC10125981 DOI: 10.1038/s41598-023-33839-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Accepted: 04/19/2023] [Indexed: 04/26/2023] Open
Abstract
Spider silk fibres have unique mechanical properties due to their hierarchical structure and the nanoscale organization of their proteins. Novel imaging techniques reveal new insights into the macro- and nanoscopic structure of Major (MAS) and Minor (MiS) Ampullate silk fibres from pristine samples of the orb-web spider Nephila Madagascariensis. Untreated threads were imaged using Coherent Anti-Stokes Raman Scattering and Confocal Microscopy, which revealed an outer lipid layer surrounding an autofluorescent protein core, that is divided into two layers in both fibre types. Helium ion imaging shows the inner fibrils without chemical or mechanical modifications. The fibrils are arranged parallel to the long axis of the fibres with typical spacing between fibrils of 230 nm ± 22 nm in the MAS fibres and 99 nm ± 24 nm in the MiS fibres. Confocal Reflection Fluorescence Depletion (CRFD) microscopy imaged these nano-fibrils through the whole fibre and showed diameters of 145 nm ± 18 nm and 116 nm ± 12 nm for MAS and MiS, respectively. The combined data from HIM and CRFD suggests that the silk fibres consist of multiple nanoscale parallel protein fibrils with crystalline cores oriented along the fibre axes, surrounded by areas with less scattering and more amorphous protein structures.
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Affiliation(s)
- Irina Iachina
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
- Mads Clausen Institute, SDU NanoSYD, University of Southern Denmark, Sønderborg, Denmark
| | - Jacek Fiutowski
- Mads Clausen Institute, SDU NanoSYD, University of Southern Denmark, Sønderborg, Denmark
| | - Horst-Günter Rubahn
- Mads Clausen Institute, SDU NanoSYD, University of Southern Denmark, Sønderborg, Denmark
| | - Fritz Vollrath
- Department of Biology, University of Oxford, South Parks Rd., Oxford, UK
| | - Jonathan R Brewer
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark.
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8
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Gupta A, Kallianpur M, Roy DS, Engberg O, Chakrabarty H, Huster D, Maiti S. Different membrane order measurement techniques are not mutually consistent. Biophys J 2023; 122:964-972. [PMID: 36004780 PMCID: PMC10111216 DOI: 10.1016/j.bpj.2022.08.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 08/10/2022] [Accepted: 08/19/2022] [Indexed: 11/25/2022] Open
Abstract
"Membrane order" is a term commonly used to describe the elastic and mechanical properties of the lipid bilayer, though its exact meaning is somewhat context- and method dependent. These mechanical properties of the membrane control many cellular functions and are measured using various biophysical techniques. Here, we ask if the results obtained from various techniques are mutually consistent. Such consistency cannot be assumed a priori because these techniques probe different spatial locations and different spatial and temporal scales. We evaluate the change of membrane order induced by serotonin using nine different techniques in lipid bilayers of three different compositions. Serotonin is an important neurotransmitter present at 100s of mM concentrations in neurotransmitter vesicles, and therefore its interaction with the lipid bilayer is biologically relevant. Our measurement tools include fluorescence of lipophilic dyes (Nile Red, Laurdan, TMA-DPH, DPH), whose properties are a function of membrane order; atomic force spectroscopy, which provides a measure of the force required to indent the lipid bilayer; 2H solid-state NMR spectroscopy, which measures the molecular order of the lipid acyl chain segments; fluorescence correlation spectroscopy, which provides a measure of the diffusivity of the probe in the membrane; and Raman spectroscopy, where spectral intensity ratios are affected by acyl chain order. We find that different measures often do not correlate with each other and sometimes even yield conflicting results. We conclude that no probe provides a general measure of membrane order and that any inference based on the change of membrane order measured by a particular probe may be unreliable.
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Affiliation(s)
- Ankur Gupta
- Tata Institute of Fundamental Research, Colaba, Mumbai, India
| | | | | | - Oskar Engberg
- Institute of Medical Physics and Biophysics, University of Leipzig, Leipzig, Germany
| | | | - Daniel Huster
- Tata Institute of Fundamental Research, Colaba, Mumbai, India; Institute of Medical Physics and Biophysics, University of Leipzig, Leipzig, Germany.
| | - Sudipta Maiti
- Tata Institute of Fundamental Research, Colaba, Mumbai, India.
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9
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Huang A, Adler J, Parmryd I. Optimised generalized polarisation analysis of C-laurdan reveals clear order differences between T cell membrane compartments. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2023; 1865:184094. [PMID: 36379264 DOI: 10.1016/j.bbamem.2022.184094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 11/09/2022] [Accepted: 11/10/2022] [Indexed: 11/15/2022]
Abstract
Heterogenous packing of plasma membrane lipids is important for cellular processes like signalling, adhesion and sorting of membrane components. Solvatochromic membrane fluorophores that respond to changes from liquid-ordered (lo) phase to liquid-disordered (ld) by red shifts in their emission spectra are often used to assess lipid packing. Their response can be quantified using generalized polarisation (GP) using fluorescence microscopy images from two emission ranges, preferably from a region of interest (ROI) limited to a specific membrane compartment. However, image quality is limited by Poisson noise and convolution by the point spread function of the imaging system. Examining GP-analysis of C-laurdan labelled T cells using the image restoration procedure deconvolution, we demonstrate that deconvolution substantially improves the image resolution by making the plasma membrane clearly discernible and facilitating plasma membrane ROI selection. We conclude that automatic ROI selection has advantages over manual ROI selection when it comes to reproducibility and speed, but reliable GP-measurements can also be obtained by manually demarcated ROIs. We find that deconvolution enhances the difference in GP-values between the plasma and intracellular membranes and demonstrate that moving an intensity defined plasma membrane ROI outwards from the cell further improves this differentiation. By systematically changing the key deconvolution regularization parameter signal to noise, we establish a protocol for deconvolution optimisation applicable to any solvatochromic dye and imaging system. The image processing and ROI selection protocol presented improves both the resolution and precision of GP-measurement and will enable detection of smaller changes in membrane order than is currently achievable.
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Affiliation(s)
- Ainsley Huang
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Jeremy Adler
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Ingela Parmryd
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
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10
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Jakobsen ND, Kaiser K, Ebbesen MF, Lauritsen L, Gjerstorff MF, Kuntsche J, Brewer JR. The ROC skin model: a robust skin equivalent for permeation and live cell imaging studies. Eur J Pharm Sci 2022; 178:106282. [PMID: 35995349 DOI: 10.1016/j.ejps.2022.106282] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 07/27/2022] [Accepted: 08/18/2022] [Indexed: 02/07/2023]
Abstract
Rat Epidermal Keratinocyte (REK) Organotypic Culture (ROC) is an epidermis model that is robust and inexpensive to develop and maintain, and it has in previous studies been shown to have permeability characteristics close to those of human skin. Here, we characterize the model further by structural comparison to native human and rat skin and by investigating functional characteristics of lipid packing, polarity, and permeability coefficients. We show that the ROC model has structural similarities to native human skin and observe human skin-like permeability coefficients for testosterone and mannitol. We develop a transwell device that allows live cell microscopy of the tissue at the air-liquid interface and establish transgenic cell lines expressing different fluorescently tagged proteins. This enables showing the migration of keratinocytes during the first days after seeding, finding that keratinocytes have a higher mean migration rate in the earlier days of development. Collectively, our results show that the ROC model is an inexpensive and robust epidermis model that works reproducibly across laboratories.
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Affiliation(s)
| | - Katharina Kaiser
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5000 Odense, Denmark
| | - Morten Frendø Ebbesen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5000 Odense, Denmark
| | - Line Lauritsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5000 Odense, Denmark
| | - Morten Frier Gjerstorff
- Department of Cancer and Inflammation Research, Institute for Molecular Medicine, University of Southern Denmark, 5000 Odense, Denmark
| | - Judith Kuntsche
- Department of Physics, Chemistry, and Pharmacy, University of Southern Denmark, 5000 Odense, Denmark
| | - Jonathan R Brewer
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5000 Odense, Denmark.
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11
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Calori IR, Pinheiro L, Braga G, de Morais FAP, Caetano W, Tedesco AC, Hioka N. Interaction of triblock copolymers (Pluronic®) with DMPC vesicles: a photophysical and computational study. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 275:121178. [PMID: 35366523 DOI: 10.1016/j.saa.2022.121178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/10/2022] [Accepted: 03/17/2022] [Indexed: 06/14/2023]
Abstract
Pluronic/lipid mix promises stealth liposomes with long circulation time and long-term stability for pharmaceutical applications. However, the influence of Pluronics on several aspects of lipid membranes has not been fully elucidated. Herein it was described the effect of Pluronics on the structured water, alkyl chain conformation, and kinetic stability of dimyristoylphosphatidylcholine (DMPC) liposomes using interfacial and deeper fluorescent probes along with computational molecular modeling data. Interfacial water changed as a function of Pluronics' hydrophobicity with polypropylene oxide (PPO) anchoring the copolymers in the lipid bilayer. Pluronics with more than 30-40 PO units had facilitated penetration at the bilayer while shorter PPO favored a more interfacial interaction. Low Pluronic concentrations provided long-term stability of vesicles by steric effects of polyethylene oxide (PEO), but high amounts destabilized the vesicles as a sum of water-bridge cleavage at the polar head group and the reduced alkyl-alkyl interactions among the lipids. The high kinetic stability of Pluronic/DMPC vesicles is a proof-of-concept of its advantages and applicability in nanotechnology over conventional liposome-based pharmaceutical products for future biomedical applications.
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Affiliation(s)
- Italo Rodrigo Calori
- Department of Chemistry, Center of Nanotechnology and Tissue Engineering, Photobiology and Photomedicine Research Group, Faculty of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo 14040-901, Brazil
| | - Lukas Pinheiro
- Department of Chemistry, Research Nucleus of Photodynamic Therapy, State University of Maringá, Av. Colombo 5790, Maringá, Paraná 97020-900, Brazil
| | - Gustavo Braga
- Department of Chemistry, Research Nucleus of Photodynamic Therapy, State University of Maringá, Av. Colombo 5790, Maringá, Paraná 97020-900, Brazil
| | - Flávia Amanda Pedroso de Morais
- Department of Chemistry, Research Nucleus of Photodynamic Therapy, State University of Maringá, Av. Colombo 5790, Maringá, Paraná 97020-900, Brazil
| | - Wilker Caetano
- Department of Chemistry, Research Nucleus of Photodynamic Therapy, State University of Maringá, Av. Colombo 5790, Maringá, Paraná 97020-900, Brazil
| | - Antonio Claudio Tedesco
- Department of Chemistry, Center of Nanotechnology and Tissue Engineering, Photobiology and Photomedicine Research Group, Faculty of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo 14040-901, Brazil.
| | - Noboru Hioka
- Department of Chemistry, Research Nucleus of Photodynamic Therapy, State University of Maringá, Av. Colombo 5790, Maringá, Paraná 97020-900, Brazil
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12
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Maiti A, Daschakraborty S. Can Urea and Trimethylamine- N-oxide Prevent the Pressure-Induced Phase Transition of Lipid Membrane? J Phys Chem B 2022; 126:1426-1440. [PMID: 35139638 DOI: 10.1021/acs.jpcb.1c08891] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Organisms dwelling in ocean trenches are exposed to the high hydrostatic pressure of ocean water. Increasing pressure can alter the membrane packing density and fluidity and trigger the fluid-to-gel phase transition. To combat environmental stress, the organisms synthesize small polar solutes, which are known as osmolytes. Urea and trimethylamine-N-oxide (TMAO) are two such solutes found in deep-sea creatures. While TMAO stabilizes protein, urea induces protein denaturation. These solutes strongly influence the packing density and membrane fluidity of the lipid bilayer at different conditions. But can these solutes affect the pressure-induced phase transition of the lipid membrane? In the present work, we have studied the effect of these two solutes on pressure-induced fluid-to-gel phase transition based on the all-atom molecular dynamics (MD) simulation approach. A high-pressure-stimulated fluid-to-gel phase transition of the membrane is seen at 800 bar, which is consistent with previous experiments. We have also observed that in the low-pressure region (1-400 bar), urea slightly increases the membrane fluidity where TMAO decreases the same. However, the phase transition pressure remains almost unchanged on the addition of urea while TMAO shifts the phase transition toward a lower pressure. We have found that the hydrogen (H)-bond interaction between lipid and urea plays an important role in preserving the fluidity of the membrane in the low-pressure zone. However, at a higher pressure, both water and urea are excluded from the membrane surface. TMAO is also excluded from the interfacial region of the membrane at all pressures. Exclusion from the membrane surface further triggers the phase transition of the lipid membrane from the fluid to gel phase at a high pressure.
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Affiliation(s)
- Archita Maiti
- Department of Chemistry, Indian Institute of Technology Patna, Bihar 801106, India
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13
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Mangiarotti A, Bagatolli LA. Impact of macromolecular crowding on the mesomorphic behavior of lipid self-assemblies. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1863:183728. [PMID: 34416246 DOI: 10.1016/j.bbamem.2021.183728] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 07/19/2021] [Accepted: 08/06/2021] [Indexed: 11/26/2022]
Abstract
Using LAURDAN fluorescence we observed that water dynamics measured at the interface of DOPC bilayers can be differentially regulated by the presence of crowded suspensions of different proteins (HSA, IgG, Gelatin) and PEG, under conditions where the polymers are not in direct molecular contact with the lipid interface. Specifically, we found that the decrease in water dipolar relaxation at the membrane interface correlates with an increased fraction of randomly oriented (or random coil) configurations in the polymers, as Gelatin > PEG > IgG > HSA. By using the same experimental strategy, we also demonstrated that structural transitions from globular to extended conformations in proteins can induce transitions between lamellar and non-lamellar phases in mixtures of DOPC and monoolein. Independent experiments using Raman spectroscopy showed that aqueous suspensions of polymers exhibiting high proportions of randomly oriented conformations display increased fractions of tetracoordinated water, a configuration that is dominant in ice. This indicates a greater capacity of this type of structure for polarizing water and consequently reducing its chemical activity. This effect is in line with one of the tenets of the Association Induction Hypothesis, which predicts a long-range dynamic structuring of water molecules via their interactions with proteins (or other polymers) showing extended conformations. Overall, our results suggest a crucial role of water in promoting couplings between structural changes in macromolecules and supramolecular arrangements of lipids. This mechanism may be of relevance to cell structure/function when the crowded nature of the intracellular milieu is considered.
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Affiliation(s)
- Agustín Mangiarotti
- Instituto de Investigación Médica Mercedes y Martín Ferreyra - INIMEC (CONICET) - Universidad Nacional de Córdoba, Friuli 2434, 5016 Córdoba, Argentina
| | - Luis A Bagatolli
- Instituto de Investigación Médica Mercedes y Martín Ferreyra - INIMEC (CONICET) - Universidad Nacional de Córdoba, Friuli 2434, 5016 Córdoba, Argentina; Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina.
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14
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Marquezin CA, Lamy MT, de Souza ES. Molecular collisions or resonance energy transfer in lipid vesicles? A methodology to tackle this question. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.117405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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15
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Färber N, Westerhausen C. Broad lipid phase transitions in mammalian cell membranes measured by Laurdan fluorescence spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1864:183794. [PMID: 34627747 DOI: 10.1016/j.bbamem.2021.183794] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/27/2021] [Accepted: 09/30/2021] [Indexed: 11/24/2022]
Abstract
Employing fluorescence spectroscopy and the membrane-embedded dye Laurdan we experimentally show that linear changes of cell membrane order in the physiological temperature regime are part of broad order-disorder-phase transitions which extend over a much broader temperature range. Even though these extreme temperatures are usually not object of live science research due to failure of cellular functions, our findings help to understand and predict cell membrane properties under physiological conditions as they explain the underlying physics of a broad order-disorder phase transition. Therefore, we analyzed the membranes of various cell lines, red blood cell ghosts and lipid vesicles by spectral decomposition in a custom-made setup in a temperature range from -40 °C to +90 °C. While the generalized polarization as a measure for membrane order of artificial lipid membranes like phosphatidylcholine show sharp transitions as known from calorimetry measurements, living cells in a physiological temperature range do only show linear changes. However, extending the temperature range shows the existence of broad transitions and their sensitivity to cholesterol content, pH and anaesthetic. Moreover, adaptation to culture conditions like decreased temperature and morphological changes like detachment of adherent cells or dendrite growth are accompanied by changes in membrane order as well. The observed changes of the generalized polarization are equivalent to temperature changes dT in the range of +12 K < dT < -6 K.
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Affiliation(s)
- Nicolas Färber
- Experimental Physics I, Institute of Physics, University of Augsburg, Universitätsstr. 1, 86159 Augsburg, Germany; Physiology, Institute of Theoretical Medicine, University of Augsburg, Universitätsstraße 2, 86159 Augsburg, Germany
| | - Christoph Westerhausen
- Experimental Physics I, Institute of Physics, University of Augsburg, Universitätsstr. 1, 86159 Augsburg, Germany; Physiology, Institute of Theoretical Medicine, University of Augsburg, Universitätsstraße 2, 86159 Augsburg, Germany; Center for NanoScience (CeNS), Ludwig Maximilians Universität Munich, 80799 Munich, Germany.
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16
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Maiti A, Daschakraborty S. How Do Urea and Trimethylamine N-Oxide Influence the Dehydration-Induced Phase Transition of a Lipid Membrane? J Phys Chem B 2021; 125:10149-10165. [PMID: 34486370 DOI: 10.1021/acs.jpcb.1c05852] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Living organisms are often exposed to extreme dehydration, which is detrimental to the structure and function of the cell membrane. The lipid membrane undergoes fluid-to-gel phase transition due to dehydration and thus loses fluidity and functionality. To protect the fluid phase of the bilayer these organisms adopt several strategies. Enhanced production of small polar organic solutes (also called osmolytes) is one such strategy. Urea and trimethylamine N-oxide (TMAO) are two osmolytes found in different organisms combating osmotic stress. Previous experiments have found that both these osmolytes have strong effects on lipid membrane under different hydration conditions. Urea prevents the dehydration-induced phase transition of the lipid membrane by directly interacting with the lipids, while TMAO does not inhibit the phase transition. To provide atomistic insights, we have carried out all-atom molecular dynamics (MD) simulation of a lipid membrane under varying hydration levels and studied the effect of these osmolytes on different structural and dynamic properties of the membrane. This study suggests that urea significantly inhibits the dehydration-induced fluid-to-gel phase transition by strongly interacting with the lipid membrane via hydrogen bonds, which balances the reduced lipid hydration due to the decreasing water content. In contrast, TMAO is excluded from the membrane surface due to unfavorable interaction with the lipids. This induces further dehydration of the lipids which reinforces the fluid-to-gel phase transition. We have also studied the counteractive role of TMAO on the effect of urea on lipid membrane when both the osmolytes are present. TMAO draws some urea molecules out of the membrane and thereby reduces the effect of urea on the lipid membrane at lower hydration levels. This is similar to the counteraction of urea's deleterious effects on protein by TMAO. All these observations are consistent with the experimental results and thus provide deep molecular insights into the role of these osmolytes in protecting the fluid phase of the membrane, the key survival strategy against osmotic-stress-induced dehydration.
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Affiliation(s)
- Archita Maiti
- Department of Chemistry, Indian Institute of Technology Patna, Bihar 801106, India
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17
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Wu E, Guo X, Teng X, Zhang R, Li F, Cui Y, Zhang D, Liu Q, Luo J, Wang J, Chen R. Discovery of Plasma Membrane-Associated RNAs through APEX-seq. Cell Biochem Biophys 2021; 79:905-917. [PMID: 34028638 DOI: 10.1007/s12013-021-00991-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/03/2021] [Indexed: 02/08/2023]
Abstract
In addition to nucleic acids, a variety of other biomolecules have also been found on the plasma membrane. Although researchers have realized that RNA has the ability to bind to membrane vesicles in vitro, little is known about whether and how RNA connects to the plasma membrane of the cell. The combination of high-throughput sequencing and in situ labeling methods provides an innovative approach for large-scale identification of subcellular RNAs. Here, we applied the recently published method APEX-seq and identified 75 RNAs related to the plasma membrane, in which lncRNA PMAR72 (plasma membrane-associated RNA AL121772.1) has a considerable affinity with sphingomyelin (SM) and localizes within distinct membrane foci. Our findings will provide some new evidence to elaborate the relationship between RNA and the plasma membrane of mammalian cells.
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Affiliation(s)
- Erzhong Wu
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China.,University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Xuzhen Guo
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China.,University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Xueyi Teng
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China.,University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Ruijin Zhang
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China.,University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Fahui Li
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China
| | - Ya Cui
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China
| | - Dongdong Zhang
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China
| | - Qinghua Liu
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China
| | - Jianjun Luo
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China. .,University of Chinese Academy of Sciences, 100049, Beijing, China.
| | - Jiangyun Wang
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China. .,University of Chinese Academy of Sciences, 100049, Beijing, China.
| | - Runsheng Chen
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China. .,University of Chinese Academy of Sciences, 100049, Beijing, China.
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18
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Maiti A, Daschakraborty S. Effect of TMAO on the Structure and Phase Transition of Lipid Membranes: Potential Role of TMAO in Stabilizing Cell Membranes under Osmotic Stress. J Phys Chem B 2021; 125:1167-1180. [PMID: 33481606 DOI: 10.1021/acs.jpcb.0c08335] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Extremophiles adopt strategies to deal with different environmental stresses, some of which are severely damaging to their cell membrane. To combat high osmotic stress, deep-sea organisms synthesize osmolytes, small polar organic molecules, like trimethylamine-N-oxide (TMAO), and incorporate them in the cell. TMAO is known to protect cells from high osmotic or hydrostatic pressure. Several experimental and simulation studies have revealed the roles of such osmolytes on stabilizing proteins. In contrast, the effect of osmolytes on the lipid membrane is poorly understood and broadly debated. A recent experiment has found strong evidence of the possible role of TMAO in stabilizing lipid membranes. Using the molecular dynamics (MD) simulation technique, we have demonstrated the effect of TMAO on two saturated fully hydrated lipid membranes in their fluid and gel phases. We have captured the impact of TMAO's concentration on the membrane's structural properties along with the fluid/gel phase transition temperatures. On increasing the concentration of TMAO, we see a substantial increase in the packing density of the membrane (estimated by area, thickness, and volume) and enhancement in the orientational order of lipid molecules. Having repulsive interaction with the lipid head group, the TMAO molecules are expelled away from the membrane surface, which induces dehydration of the lipid head groups, increasing the packing density. The addition of TMAO also increases the fluid/gel phase transition temperature of the membrane. All of these results are in close agreement with the experimental observations. This study, therefore, provides a molecular-level understanding of how TMAO can influence the cell membrane of deep-sea organisms and help in combating the osmotic stress condition.
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Affiliation(s)
- Archita Maiti
- Department of Chemistry, Indian Institute of Technology Patna, Patna, Bihar 801106, India
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19
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Morandi MI, Kluzek M, Wolff J, Schroder A, Thalmann F, Marques CM. Accumulation of styrene oligomers alters lipid membrane phase order and miscibility. Proc Natl Acad Sci U S A 2021; 118:e2016037118. [PMID: 33468682 PMCID: PMC7848699 DOI: 10.1073/pnas.2016037118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Growth of plastic waste in the natural environment, and in particular in the oceans, has raised the accumulation of polystyrene and other polymeric species in eukyarotic cells to the level of a credible and systemic threat. Oligomers, the smallest products of polymer degradation or incomplete polymerization reactions, are the first species to leach out of macroscopic or nanoscopic plastic materials. However, the fundamental mechanisms of interaction between oligomers and polymers with the different cell components are yet to be elucidated. Simulations performed on lipid bilayers showed changes in membrane mechanical properties induced by polystyrene, but experimental results performed on cell membranes or on cell membrane models are still missing. We focus here on understanding how embedded styrene oligomers affect the phase behavior of model membranes using a combination of scattering, fluorescence, and calorimetric techniques. Our results show that styrene oligomers disrupt the phase behavior of lipid membranes, modifying the thermodynamics of the transition through a spatial modulation of lipid composition.
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Affiliation(s)
- Mattia I Morandi
- Institut Charles Sadron, Université de Strasbourg, CNRS, UPR022, 67034 Strasbourg Cedex, France
| | - Monika Kluzek
- Institut Charles Sadron, Université de Strasbourg, CNRS, UPR022, 67034 Strasbourg Cedex, France
| | - Jean Wolff
- Institut Charles Sadron, Université de Strasbourg, CNRS, UPR022, 67034 Strasbourg Cedex, France
| | - André Schroder
- Institut Charles Sadron, Université de Strasbourg, CNRS, UPR022, 67034 Strasbourg Cedex, France
| | - Fabrice Thalmann
- Institut Charles Sadron, Université de Strasbourg, CNRS, UPR022, 67034 Strasbourg Cedex, France
| | - Carlos M Marques
- Institut Charles Sadron, Université de Strasbourg, CNRS, UPR022, 67034 Strasbourg Cedex, France
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20
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The interaction of a thiosemicarbazone derived from R - (+) - limonene with lipid membranes. Chem Phys Lipids 2020; 234:105018. [PMID: 33232725 DOI: 10.1016/j.chemphyslip.2020.105018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 11/14/2020] [Accepted: 11/16/2020] [Indexed: 11/21/2022]
Abstract
As a potential drug, 2-nitrobenzaldehyde-thiosemicarbazone (2-TSC), a thiosemicarbazone derived from the terpene R-(+)-limonene, was studied through calorimetric and spectroscopic techniques. Differential Scanning Calorimetry (DSC) data showed that 2-TSC causes structural changes in a 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DMPC) membrane, strongly decreasing the cooperativity of the bilayer gel-fluid thermal transition. Optical absorption spectroscopy showed that 2-TSC is more soluble in ethanol and lipids than in water medium, and that the drug displays different structures in the different environments. Though 2-TSC displays no fluorescence, time resolved fluorescence showed that the drug is an effective quencher of the fluorescent probe 6-dodecanoyl-2-dimethylaminonaphthalene (Laurdan). As it is well accepted that Laurdan is positioned into the bilayer close to the membrane surface, that is possibly the localization of 2-TSC in a bilayer. Electron spin resonance (ESR) of the probe 1-palmitoyl-2-stearoyl-(14-doxyl)-sn-glycero-3-phosphocholine (14-PCSL) revealed that 2-TSC is inserted into the hydrocarbon part of the bilayer, fluidizing the lipid bilayer gel phase and rigidifying or organizing the bilayer fluid phase. Similar effects are found for other lipophilic molecules, including cholesterol. These results are useful to improve the understanding of the processes that govern the interaction of thiosemicarbazones with cell membranes, related to the activity of the drugs and their cytotoxicity.
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21
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Frias MA, Disalvo EA. Breakdown of classical paradigms in relation to membrane structure and functions. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1863:183512. [PMID: 33202248 DOI: 10.1016/j.bbamem.2020.183512] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 11/11/2020] [Accepted: 11/12/2020] [Indexed: 01/10/2023]
Abstract
Updates of the mosaic fluid membrane model implicitly sustain the paradigms that bilayers are closed systems conserving a state of fluidity and behaving as a dielectric slab. All of them are a consequence of disregarding water as part of the membrane structure and its essential role in the thermodynamics and kinetics of membrane response to bioeffectors. A correlation of the thermodynamic properties with the structural features of water makes possible to introduce the lipid membrane as a responsive structure due to the relaxation of water rearrangements in the kinetics of bioeffectors' interactions. This analysis concludes that the lipid membranes are open systems and, according to thermodynamic of irreversible formalism, bilayers and monolayers can be reasonable compared under controlled conditions. The inclusion of water in the complex structure makes feasible to reconsider the concept of dielectric slab and fluidity.
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Affiliation(s)
- M A Frias
- Applied Biophysics and Food Research Center, CIBAAL-UNSE-CONICET, Santiago del Estero, Argentina
| | - E A Disalvo
- Applied Biophysics and Food Research Center, CIBAAL-UNSE-CONICET, Santiago del Estero, Argentina.
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22
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Horne JE, Brockwell DJ, Radford SE. Role of the lipid bilayer in outer membrane protein folding in Gram-negative bacteria. J Biol Chem 2020; 295:10340-10367. [PMID: 32499369 PMCID: PMC7383365 DOI: 10.1074/jbc.rev120.011473] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 06/03/2020] [Indexed: 01/09/2023] Open
Abstract
β-Barrel outer membrane proteins (OMPs) represent the major proteinaceous component of the outer membrane (OM) of Gram-negative bacteria. These proteins perform key roles in cell structure and morphology, nutrient acquisition, colonization and invasion, and protection against external toxic threats such as antibiotics. To become functional, OMPs must fold and insert into a crowded and asymmetric OM that lacks much freely accessible lipid. This feat is accomplished in the absence of an external energy source and is thought to be driven by the high thermodynamic stability of folded OMPs in the OM. With such a stable fold, the challenge that bacteria face in assembling OMPs into the OM is how to overcome the initial energy barrier of membrane insertion. In this review, we highlight the roles of the lipid environment and the OM in modulating the OMP-folding landscape and discuss the factors that guide folding in vitro and in vivo We particularly focus on the composition, architecture, and physical properties of the OM and how an understanding of the folding properties of OMPs in vitro can help explain the challenges they encounter during folding in vivo Current models of OMP biogenesis in the cellular environment are still in flux, but the stakes for improving the accuracy of these models are high. OMP folding is an essential process in all Gram-negative bacteria, and considering the looming crisis of widespread microbial drug resistance it is an attractive target. To bring down this vital OMP-supported barrier to antibiotics, we must first understand how bacterial cells build it.
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Affiliation(s)
- Jim E Horne
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - David J Brockwell
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Sheena E Radford
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
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Pérez HA, Cejas JP, Rosa AS, Giménez RE, Disalvo EA, Frías MA. Modulation of Interfacial Hydration by Carbonyl Groups in Lipid Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:2644-2653. [PMID: 32073276 DOI: 10.1021/acs.langmuir.9b03551] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The lack of carbonyl groups and the presence of ether bonds give the lipid interphase a different water organization around the phosphate groups that affects the compressibility and electrical properties of lipid membranes. Generalized polarization of 1,2-di-O-tetradecyl-sn-glycero-3-phosphocholine (14:0 diether PC) in correlation with Fourier transform infrared (FTIR) analysis indicates a higher level of polarizability of water molecules in the membrane phase around the phosphate groups both below and above Tm. This reorganization of water promotes a different response in compressibility and dipole moment of the interphase, which is related to different H bonding of water molecules with phosphates (PO) and carbonyl (CO) groups.
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Affiliation(s)
- H A Pérez
- Applied Biophysics and Food Research Center (Centro de Investigaciones en Biofisica Aplicada y Alimentos, CIBAAL), National University of Santiago del Estero and CONICET, RN 9, Km 1125, 4206 Santiago del Estero, Argentina
| | - J P Cejas
- Applied Biophysics and Food Research Center (Centro de Investigaciones en Biofisica Aplicada y Alimentos, CIBAAL), National University of Santiago del Estero and CONICET, RN 9, Km 1125, 4206 Santiago del Estero, Argentina
| | - A S Rosa
- Applied Biophysics and Food Research Center (Centro de Investigaciones en Biofisica Aplicada y Alimentos, CIBAAL), National University of Santiago del Estero and CONICET, RN 9, Km 1125, 4206 Santiago del Estero, Argentina
| | - R E Giménez
- Applied Biophysics and Food Research Center (Centro de Investigaciones en Biofisica Aplicada y Alimentos, CIBAAL), National University of Santiago del Estero and CONICET, RN 9, Km 1125, 4206 Santiago del Estero, Argentina
| | - E A Disalvo
- Applied Biophysics and Food Research Center (Centro de Investigaciones en Biofisica Aplicada y Alimentos, CIBAAL), National University of Santiago del Estero and CONICET, RN 9, Km 1125, 4206 Santiago del Estero, Argentina
| | - M A Frías
- Applied Biophysics and Food Research Center (Centro de Investigaciones en Biofisica Aplicada y Alimentos, CIBAAL), National University of Santiago del Estero and CONICET, RN 9, Km 1125, 4206 Santiago del Estero, Argentina
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Bagatolli LA, Stock RP, Olsen LF. Coupled Response of Membrane Hydration with Oscillating Metabolism in Live Cells: An Alternative Way to Modulate Structural Aspects of Biological Membranes? Biomolecules 2019; 9:E687. [PMID: 31684090 PMCID: PMC6921054 DOI: 10.3390/biom9110687] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 10/29/2019] [Accepted: 10/30/2019] [Indexed: 12/12/2022] Open
Abstract
We propose that active metabolic processes may regulate structural changes in biological membranes via the physical state of cell water. This proposition is based on recent results obtained from our group in yeast cells displaying glycolytic oscillations, where we demonstrated that there is a tight coupling between the oscillatory behavior of glycolytic metabolites (ATP, NADH) and the extent of the dipolar relaxation of intracellular water, which oscillates synchronously. The mechanism we suggest involves the active participation of a polarized intracellular water network whose degree of polarization is dynamically modulated by temporal ATP fluctuations caused by metabolism with intervention of a functional cytoskeleton, as conceived in the long overlooked association-induction hypothesis (AIH) of Gilbert Ling. Our results show that the polarized state of intracellular water can be propagated from the cytosol to regions containing membranes. Since changes in the extent of the polarization of water impinge on its chemical activity, we hypothesize that metabolism dynamically controls the local structure of cellular membranes via lyotropic effects. This hypothesis offers an alternative way to interpret membrane related phenomena (e.g., changes in local curvature pertinent to endo/exocytosis or dynamical changes in membranous organelle structure, among others) by integrating relevant but mostly overlooked physicochemical characteristics of the cellular milieu.
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Affiliation(s)
- Luis A Bagatolli
- Instituto de Investigación Médica Mercedes y Martín Ferreyra-INIMEC (CONICET)-Universidad Nacional de Córdoba, Friuli 2434, Córdoba 5016, Argentina.
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba 5000, Argentina.
| | - Roberto P Stock
- MEMPHYS-International and Interdisciplinary Research Network, 5230 Odense, Denmark.
| | - Lars F Olsen
- University of Southern Denmark, Institute for Biochemistry and Molecular Biology, Campusvej 55, 5230 Odense, Denmark.
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