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Hossen F, Geng X, Sun GY, Yao X, Lee JC. Oligomeric Amyloid-β and Tau Alter Cell Adhesion Properties and Induce Inflammatory Responses in Cerebral Endothelial Cells Through the RhoA/ROCK Pathway. Mol Neurobiol 2024:10.1007/s12035-024-04138-z. [PMID: 38561558 DOI: 10.1007/s12035-024-04138-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 03/19/2024] [Indexed: 04/04/2024]
Abstract
Dysfunction of cerebral endothelial cells (CECs) has been implicated in the pathology of Alzheimer's disease (AD). Despite evidence showing cytotoxic effects of oligomeric amyloid-β (oAβ) and Tau (oTau) in the central nervous system, their direct effects on CECs have not been fully investigated. In this study, we examined the direct effects of oAβ, oTau, and their combination on cell adhesion properties and inflammatory responses in CECs. We found that both oAβ and oTau increased cell stiffness, as well as the p-selectin/Sialyl-LewisX (sLeX) bonding-mediated membrane tether force and probability of adhesion in CECs. Consistent with these biomechanical alterations, treatments with oAβ or oTau also increased actin polymerization and the expression of p-selectin at the cell surface. These toxic oligomeric peptides also triggered inflammatory responses, including upregulations of p-NF-kB p65, IL-1β, and TNF-α. In addition, they rapidly activated the RhoA/ROCK pathway. These biochemical and biomechanical changes were further enhanced by the treatment with the combination of oAβ and oTau, which were significantly suppressed by Fasudil, a specific inhibitor for the RhoA/ROCK pathway. In conclusion, our data suggest that oAβ, oTau, and their combination triggered subcellular mechanical alterations and inflammatory responses in CECs through the RhoA/ROCK pathway.
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Affiliation(s)
- Faruk Hossen
- Richard and Loan Hill Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - Xue Geng
- Richard and Loan Hill Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - Grace Y Sun
- Department of Biochemistry, University of Missouri, Columbia, MO, 65211, USA
| | - Xincheng Yao
- Richard and Loan Hill Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - James C Lee
- Richard and Loan Hill Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, 60607, USA.
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2
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Kumar H, Mandal S, Yadav R, Gupta S, Meena H, Kadu M, Kudawla R, Sharma P, Kaur IP, Maiti S, Ipsen JH, Bhatia T. Bottom-up approach to explore alpha-amylase assisted membrane remodelling. Chem Phys Lipids 2024; 259:105374. [PMID: 38176612 DOI: 10.1016/j.chemphyslip.2023.105374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 12/19/2023] [Accepted: 12/27/2023] [Indexed: 01/06/2024]
Abstract
Soluble alpha-amylases play an important role in the catabolism of polysaccharides. In this work, we show that the malt α -amylase can interact with the lipid membrane and further alter its mechanical properties. Vesicle fluctuation spectroscopy is used for quantitative measurement of the membrane bending rigidity of phosphatidylcholines lipid vesicles from the shape fluctuation based on the whole contour of Giant Unilamellar Vesicles (GUVs). The bending rigidity of the 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine lipid vesicles in water increases significantly with the presence of 0.14 micromolar alpha-amylase (AA) in the exterior solution. It appears that the enzyme present in the external solution interacts with the outer layer of the bilayer membrane, leading to an asymmetry of the solution on either side of the bilayer membrane and altering its elasticity. At AA concentration of 1.5 micromolars and above, changes in the morphology of the GUV membrane are observed. The interaction between AA in the external solution and the external leaflet causes the bilayer membrane to curve spontaneously, leading to the formation of outbuds, giving a positive spontaneous curvature of C0 ≤ 0.05 μm-1 at ≈ 1 mg / ml of the AA concentration. We validate and characterize its concentration-dependent role in stabilizing the membrane curvature. Our findings indicate that the involvement of the enzyme, depending on the concentration, can have a considerable effect on the mechanical characteristics of the membrane.
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Affiliation(s)
- Harshit Kumar
- Department of Physical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, Knowledge City, Manauli, SAS Nagar, Punjab 140306, India
| | - Sayar Mandal
- Department of Physical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, Knowledge City, Manauli, SAS Nagar, Punjab 140306, India
| | - Reena Yadav
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, Knowledge City, Manauli, SAS Nagar, Punjab 140306, India
| | - Suhasi Gupta
- Department of Physical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, Knowledge City, Manauli, SAS Nagar, Punjab 140306, India
| | - Hemraj Meena
- Department of Physical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, Knowledge City, Manauli, SAS Nagar, Punjab 140306, India
| | - Mayur Kadu
- Department of Physical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, Knowledge City, Manauli, SAS Nagar, Punjab 140306, India
| | - Rajni Kudawla
- Department of Physical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, Knowledge City, Manauli, SAS Nagar, Punjab 140306, India
| | - Pratibha Sharma
- University Institute of Pharmaceutical Sciences, Punjab University, Sector 14, Chandigarh 160014, Punjab, India
| | - Indu Pal Kaur
- University Institute of Pharmaceutical Sciences, Punjab University, Sector 14, Chandigarh 160014, Punjab, India
| | - Subhabrata Maiti
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, Knowledge City, Manauli, SAS Nagar, Punjab 140306, India
| | - John H Ipsen
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej, Odense, 5230 M, Denmark.
| | - Tripta Bhatia
- Department of Physical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, Knowledge City, Manauli, SAS Nagar, Punjab 140306, India.
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3
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Abstract
The cell membrane serves as a barrier that restricts the rate of exchange of diffusible molecules. Tension in the membrane regulates many crucial cell functions involving shape changes and motility, cell signaling, endocytosis, and mechanosensation. Tension reflects the forces contributed by the lipid bilayer, the cytoskeleton, and the extracellular matrix. With a fluid-like bilayer model, membrane tension is presumed uniform and hence propagated instantaneously. In this review, we discuss techniques to measure the mean membrane tension and how to resolve the stresses in different components and consider the role of bilayer heterogeneity.
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Affiliation(s)
- Pei-Chuan Chao
- Department of Civil, Structural and Environmental Engineering, University at Buffalo, The State University of New York, Buffalo, NY, United States
| | - Frederick Sachs
- Department of Physiology and Biophysics, University at Buffalo, The State University of New York, Buffalo, NY, United States.
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4
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Mahapatra A, Uysalel C, Rangamani P. The Mechanics and Thermodynamics of Tubule Formation in Biological Membranes. J Membr Biol 2021; 254:273-291. [PMID: 33462667 PMCID: PMC8184589 DOI: 10.1007/s00232-020-00164-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 12/11/2020] [Indexed: 02/07/2023]
Abstract
Membrane tubulation is a ubiquitous process that occurs both at the plasma membrane and on the membranes of intracellular organelles. These tubulation events are known to be mediated by forces applied on the membrane either due to motor proteins, by polymerization of the cytoskeleton, or due to the interactions between membrane proteins binding onto the membrane. The numerous experimental observations of tube formation have been amply supported by mathematical modeling of the associated membrane mechanics and have provided insights into the force-displacement relationships of membrane tubes. Recent advances in quantitative biophysical measurements of membrane-protein interactions and tubule formation have necessitated the need for advances in modeling that will account for the interplay of multiple aspects of physics that occur simultaneously. Here, we present a comprehensive review of experimental observations of tubule formation and provide context from the framework of continuum modeling. Finally, we explore the scope for future research in this area with an emphasis on iterative modeling and experimental measurements that will enable us to expand our mechanistic understanding of tubulation processes in cells.
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Affiliation(s)
- Arijit Mahapatra
- Department of Mechanical and Aerospace Engineering, University of California San Diego, 9500 Gilman Dr, La Jolla, CA, 92093, USA
| | - Can Uysalel
- Department of Mechanical and Aerospace Engineering, University of California San Diego, 9500 Gilman Dr, La Jolla, CA, 92093, USA
| | - Padmini Rangamani
- Department of Mechanical and Aerospace Engineering, University of California San Diego, 9500 Gilman Dr, La Jolla, CA, 92093, USA.
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5
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Almendro-Vedia V, Natale P, Valdivieso González D, Lillo MP, Aragones JL, López-Montero I. How rotating ATP synthases can modulate membrane structure. Arch Biochem Biophys 2021; 708:108939. [PMID: 34052190 DOI: 10.1016/j.abb.2021.108939] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 05/19/2021] [Accepted: 05/20/2021] [Indexed: 01/03/2023]
Abstract
F1Fo-ATP synthase (ATP synthase) is a central membrane protein that synthetizes most of the ATP in the cell through a rotational movement driven by a proton gradient across the hosting membrane. In mitochondria, ATP synthases can form dimers through specific interactions between some subunits of the protein. The dimeric form of ATP synthase provides the protein with a spontaneous curvature that sustain their arrangement at the rim of the high-curvature edges of mitochondrial membrane (cristae). Also, a direct interaction with cardiolipin, a lipid present in the inner mitochondrial membrane, induces the dimerization of ATP synthase molecules along cristae. The deletion of those biochemical interactions abolishes the protein dimerization producing an altered mitochondrial function and morphology. Mechanically, membrane bending is one of the key deformation modes by which mitochondrial membranes can be shaped. In particular, bending rigidity and spontaneous curvature are important physical factors for membrane remodelling. Here, we discuss a complementary mechanism whereby the rotatory movement of the ATP synthase might modify the mechanical properties of lipid bilayers and contribute to the formation and regulation of the membrane invaginations.
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Affiliation(s)
- Víctor Almendro-Vedia
- Departamento Química Física, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040, Madrid, Spain; Instituto de Investigación Hospital Doce de Octubre (imas12), Avenida de Córdoba s/n, 28041, Madrid, Spain
| | - Paolo Natale
- Departamento Química Física, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040, Madrid, Spain; Instituto de Investigación Hospital Doce de Octubre (imas12), Avenida de Córdoba s/n, 28041, Madrid, Spain
| | - David Valdivieso González
- Departamento Química Física, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040, Madrid, Spain; Instituto de Investigación Hospital Doce de Octubre (imas12), Avenida de Córdoba s/n, 28041, Madrid, Spain
| | - M Pilar Lillo
- Departamento Química Física Biológica, Instituto de Química-Física "Rocasolano" (CSIC), Serrano 119, 28006, Madrid, Spain
| | - Juan L Aragones
- Departamento de Física Teórica de la Materia Condensada, Instituto Nicolás Cabrera and Condensed Matter Physics Centre (IFIMAC), Universidad Autónoma de Madrid, E-28049, Madrid, Spain
| | - Iván López-Montero
- Departamento Química Física, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040, Madrid, Spain; Instituto de Investigación Hospital Doce de Octubre (imas12), Avenida de Córdoba s/n, 28041, Madrid, Spain.
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6
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Jia R, Chai Y, Xie C, Liu G, Zhu Z, Huang K, Li W, Ou G. The spectrin-based membrane skeleton is asymmetric and remodels during neural development in C. elegans. J Cell Sci 2020; 133:jcs248583. [PMID: 32620698 DOI: 10.1242/jcs.248583] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 06/25/2020] [Indexed: 01/22/2023] Open
Abstract
Perturbation of spectrin-based membrane mechanics causes hereditary elliptocytosis and spinocerebellar ataxia, but the underlying cellular basis of pathogenesis remains unclear. Here, we introduced conserved disease-associated spectrin mutations into the Caenorhabditis elegans genome and studied the contribution of spectrin to neuronal migration and dendrite formation in developing larvae. The loss of spectrin resulted in ectopic actin polymerization outside of the existing front and secondary membrane protrusions, leading to defective neuronal positioning and dendrite morphology in adult animals. Spectrin accumulated in the lateral region and rear of migrating neuroblasts and redistributes from the soma into the newly formed dendrites, indicating that the spectrin-based membrane skeleton is asymmetric and remodels to regulate actin assembly and cell shape during development. We affinity-purified spectrin from C. elegans and showed that its binding partner ankyrin functions with spectrin. Asymmetry and remodeling of the membrane skeleton might enable spatiotemporal modulation of membrane mechanics for distinct developmental events.
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Affiliation(s)
- Ru Jia
- Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, McGovern Institute for Brain Research, School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua University, Beijing 100084, China
| | - Yongping Chai
- Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, McGovern Institute for Brain Research, School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua University, Beijing 100084, China
| | - Chao Xie
- Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, McGovern Institute for Brain Research, School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua University, Beijing 100084, China
| | - Gai Liu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Zhiwen Zhu
- Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, McGovern Institute for Brain Research, School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua University, Beijing 100084, China
| | - Kaiyao Huang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Wei Li
- School of Medicine, Tsinghua University, Beijing 100084, China
| | - Guangshuo Ou
- Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, McGovern Institute for Brain Research, School of Life Sciences and MOE Key Laboratory for Protein Science, Tsinghua University, Beijing 100084, China
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7
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Doskocz J, Dałek P, Foryś A, Trzebicka B, Przybyło M, Mesarec L, Iglič A, Langner M. The effect of lipid phase on liposome stability upon exposure to the mechanical stress. Biochim Biophys Acta Biomembr 2020; 1862:183361. [PMID: 32422137 DOI: 10.1016/j.bbamem.2020.183361] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 03/25/2020] [Accepted: 05/11/2020] [Indexed: 10/24/2022]
Abstract
Mechanical properties of a lipid bilayer are parameters determined mainly for giant unilamellar vesicles (GUVs). It is not clear if values obtained on the GUV model can be directly translated to submicron large unilamellar vesicles (LUVs). This ambiguity is a major obstacle in exploring the effect of lipid bilayer mechanics on membrane associated processes and effectiveness of liposome-based targeted drug delivery systems. In presented work extrusion, which is a common method to prepare LUVs, was used to study liposomes preparation and stability upon exposure to mechanical stress. The effect of parameters of the extrusion process (temperature, membrane pore size, extrusion force and volumetric flux) on the properties of liposome suspension (average liposome size, polydispersity index and lipid recovery ratio) was determined for model liposomes composed of DPPC lipid. The state of the DPPC lipid bilayer depends on temperature, therefore, the effect of lipid bilayer mechanics on the extrusion process can be quantitated without altering membrane composition. The extrusion process was carried out with the automated extruder delivering quantitative data on the extrusion force and volumetric flux. Obtained results have been interpreted in terms of mechanical properties of the lipid bilayer. Determined mechanical properties of the lipid bilayer and its dependence on temperature are in good agreement with the literature results determined for GUVs. This shows that mechanical properties of the lipid bilayer does not depend on the liposome size in the range from 100 nm to hundreds of microns.
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Affiliation(s)
- Joanna Doskocz
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, 50-377, Wrocław, pl. Grunwaldzki, 13, Poland.
| | - Paulina Dałek
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, 50-377, Wrocław, pl. Grunwaldzki, 13, Poland; Lipid Systems sp. z o.o., 54-613 Wrocław, ul. Krzemieniecka 48C, Poland
| | - Aleksander Foryś
- Centre of Polymer and Carbon Materials, Polish Academy of Sciences, 41-819 Zabrze, ul. M. Curie-Skłodowskiej 34, Poland
| | - Barbara Trzebicka
- Centre of Polymer and Carbon Materials, Polish Academy of Sciences, 41-819 Zabrze, ul. M. Curie-Skłodowskiej 34, Poland
| | | | - Luka Mesarec
- Laboratory of Physics, Faculty of Electrical Engineering, University of Ljubljana, SI-1000 Ljubljana, Tržaška 25, Slovenia
| | - Aleš Iglič
- Laboratory of Physics, Faculty of Electrical Engineering, University of Ljubljana, SI-1000 Ljubljana, Tržaška 25, Slovenia.; Laboratory of Mass Spectrometry and Proteomics, Institute of Biosciences and BioResources, National Research Council, 80131 Napoli, Pietro Castellino 111, Italy
| | - Marek Langner
- Lipid Systems sp. z o.o., 54-613 Wrocław, ul. Krzemieniecka 48C, Poland
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8
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Abstract
Here, we describe how to extract tethers or lipid membrane nanotubes from the plasma membrane of cells using optical tweezers. This technique allows measuring the force required to hold the membrane tether at a constant length, which is related to the cell membrane tension. Following the evolution of this force during mechanical or chemical perturbations of the cell gives insight about the regulation of cell membrane tension. By pulling very long membrane tethers, one can also probe the membrane reservoir of a cell and a sudden rise in the tether force is usually due to the depletion of excess membranes stored in membrane folds or invaginations.
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9
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Abstract
Cellular nuclei are bound by two uniformly separated lipid membranes that are fused with each other at numerous donut-shaped pores. These membranes are structurally supported by an array of distinct proteins with distinct mechanical functions. As a result, the nuclear envelope possesses unique mechanical properties, which enables it to resist cytoskeletal forces. Here, we review studies that are beginning to provide quantitative insights into nuclear membrane mechanics. We discuss how the mechanical properties of the fused nuclear membranes mediate their response to mechanical forces exerted on the nucleus and how structural reinforcement by different nuclear proteins protects the nuclear membranes against rupture. We also highlight some open questions in nuclear envelope mechanics, and discuss their relevance in the context of health and disease.
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Affiliation(s)
- Ashutosh Agrawal
- Department of Mechanical Engineering, University of Houston, Houston, TX 77204, USA
| | - Tanmay P Lele
- Department of Chemical Engineering, University of Florida, Gainesville, FL 32611, USA
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10
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Hwang H, Paracini N, Parks JM, Lakey JH, Gumbart JC. Distribution of mechanical stress in the Escherichia coli cell envelope. Biochim Biophys Acta Biomembr 2018; 1860:2566-75. [PMID: 30278180 DOI: 10.1016/j.bbamem.2018.09.020] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Revised: 09/14/2018] [Accepted: 09/26/2018] [Indexed: 01/05/2023]
Abstract
The cell envelope in Gram-negative bacteria comprises two distinct membranes with a cell wall between them. There has been a growing interest in understanding the mechanical adaptation of this cell envelope to the osmotic pressure (or turgor pressure), which is generated by the difference in the concentration of solutes between the cytoplasm and the external environment. However, it remains unexplored how the cell wall, the inner membrane (IM), and the outer membrane (OM) effectively protect the cell from this pressure by bearing the resulting surface tension, thus preventing the formation of inner membrane bulges, abnormal cell morphology, spheroplasts and cell lysis. In this study, we have used molecular dynamics (MD) simulations combined with experiments to resolve how and to what extent models of the IM, OM, and cell wall respond to changes in surface tension. We calculated the area compressibility modulus of all three components in simulations from tension-area isotherms. Experiments on monolayers mimicking individual leaflets of the IM and OM were also used to characterize their compressibility. While the membranes become softer as they expand, the cell wall exhibits significant strain stiffening at moderate to high tensions. We integrate these results into a model of the cell envelope in which the OM and cell wall share the tension at low turgor pressure (0.3 atm) but the tension in the cell wall dominates at high values (>1 atm).
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11
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Doskocz J, Drabik D, Chodaczek G, Przybyło M, Langner M. Statistical Analysis of Bending Rigidity Coefficient Determined Using Fluorescence-Based Flicker-Noise Spectroscopy. J Membr Biol 2018; 251:601-608. [PMID: 29858612 DOI: 10.1007/s00232-018-0037-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 05/29/2018] [Indexed: 10/14/2022]
Abstract
Bending rigidity coefficient describes propensity of a lipid bilayer to deform. In order to measure the parameter experimentally using flickering noise spectroscopy, the microscopic imaging is required, which necessitates the application of giant unilamellar vesicles (GUV) lipid bilayer model. The major difficulty associated with the application of the model is the statistical character of GUV population with respect to their size and the homogeneity of lipid bilayer composition, if a mixture of lipids is used. In the paper, the bending rigidity coefficient was measured using the fluorescence-enhanced flicker-noise spectroscopy. In the paper, the bending rigidity coefficient was determined for large populations of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine and 1,2-dioleoyl-sn-glycero-3-phosphocholine vesicles. The quantity of obtained experimental data allows to perform statistical analysis aiming at the identification of the distribution, which is the most appropriate for the calculation of the value of the membrane bending rigidity coefficient. It has been demonstrated that the bending rigidity coefficient is characterized by an asymmetrical distribution, which is well approximated with the gamma distribution. Since there are no biophysical reasons for that we propose to use the difference between normal and gamma fits as a measure of the homogeneity of vesicle population. In addition, the effect of a fluorescent label and types of instrumental setups on determined values has been tested. Obtained results show that the value of the bending rigidity coefficient does not depend on the type of a fluorescent label nor on the type of microscope used.
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Affiliation(s)
- Joanna Doskocz
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Pl. Grunwaldzki 13, 50-377, Wrocław, Poland.
| | - Dominik Drabik
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Pl. Grunwaldzki 13, 50-377, Wrocław, Poland
| | - Grzegorz Chodaczek
- Wroclaw Research Centre EIT+, ul. Stabłowicka 147, 54-066, Wrocław, Poland
| | - Magdalena Przybyło
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Pl. Grunwaldzki 13, 50-377, Wrocław, Poland.,Lipid Systems sp. z o.o., ul. Krzemieniecka 48C, 54-613, Wrocław, Poland
| | - Marek Langner
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Pl. Grunwaldzki 13, 50-377, Wrocław, Poland.,Lipid Systems sp. z o.o., ul. Krzemieniecka 48C, 54-613, Wrocław, Poland
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12
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Gaio N, Martino A, Toth Z, Watson JT, Nicolaou D, McBride-Gagyi S. Masquelet technique: The effect of altering implant material and topography on membrane matrix composition, mechanical and barrier properties in a rat defect model. J Biomech 2018; 72:53-62. [PMID: 29510858 PMCID: PMC5895482 DOI: 10.1016/j.jbiomech.2018.02.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 02/12/2018] [Accepted: 02/18/2018] [Indexed: 12/26/2022]
Abstract
The Masquelet technique is a surgical procedure to regenerate segmental bone defects. The two-phase treatment relies on the production of a vascularized foreign-body membrane to support bone grafts over three times larger than the traditional maximum. Historically, the procedure has always utilized a bone cement spacer to evoke membrane production. However, membrane formation can easily be effected by implant surface properties such as material and topology. This study sought to determine if the membrane's mechanical or barrier properties are affected by changing the spacer material to titanium or roughening the surface finish. Ten-week-old, male Sprague Dawley rats were given an externally stabilized, 6 mm femur defect which was filled with a pre-made spacer of bone cement (PMMA) or titanium (TI) with a smooth (∼1 μm) or roughened (∼8 μm) finish. After 4 weeks of implantation, the membranes were harvested, and the matrix composition, tensile mechanics, shrinkage, and barrier function was assessed. Roughening the spacers resulted in significantly more compliant membranes. TI spacers created membranes that inhibited solute transport more. There were no differences between groups in collagen or elastin distribution. This suggests that different membrane characteristics can be created by altering the spacer surface properties. Surgeons may unknowingly effecting membrane formation via bone cement preparation techniques.
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Affiliation(s)
- Natalie Gaio
- Department of Orthopaedic Surgery, Saint Louis University School of Medicine, 1402 S. Grand Blvd, Schwitalla Hall M176, St. Louis, MO 63132, USA
| | - Alice Martino
- Department of Orthopaedic Surgery, Saint Louis University School of Medicine, 1402 S. Grand Blvd, Schwitalla Hall M176, St. Louis, MO 63132, USA
| | - Zacharie Toth
- Department of Orthopaedic Surgery, Saint Louis University School of Medicine, 1402 S. Grand Blvd, Schwitalla Hall M176, St. Louis, MO 63132, USA
| | - J Tracy Watson
- Department of Orthopaedic Surgery, Saint Louis University School of Medicine, 1402 S. Grand Blvd, Schwitalla Hall M176, St. Louis, MO 63132, USA
| | - Daemeon Nicolaou
- Department of Orthopaedic Surgery, Saint Louis University School of Medicine, 1402 S. Grand Blvd, Schwitalla Hall M176, St. Louis, MO 63132, USA
| | - Sarah McBride-Gagyi
- Department of Orthopaedic Surgery, Saint Louis University School of Medicine, 1402 S. Grand Blvd, Schwitalla Hall M176, St. Louis, MO 63132, USA.
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13
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Tóth EA, Oszvald Á, Péter M, Balogh G, Osteikoetxea-Molnár A, Bozó T, Szabó-Meleg E, Nyitrai M, Derényi I, Kellermayer M, Yamaji T, Hanada K, Vígh L, Matkó J. Nanotubes connecting B lymphocytes: High impact of differentiation-dependent lipid composition on their growth and mechanics. Biochim Biophys Acta Mol Cell Biol Lipids 2017. [PMID: 28645851 DOI: 10.1016/j.bbalip.2017.06.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Nanotubes (NTs) are thin, long membranous structures forming novel, yet poorly known communication pathways between various cell types. Key mechanisms controlling their growth still remained poorly understood. Since NT-forming capacity of immature and mature B cells was found largely different, we investigated how lipid composition and molecular order of the membrane affect NT-formation. Screening B cell lines with various differentiation stages revealed that NT-growth linearly correlates with membrane ganglioside levels, while it shows maximum as a function of cholesterol level. NT-growth of B lymphocytes is promoted by raftophilic phosphatidylcholine and sphingomyelin species, various glycosphingolipids, and docosahexaenoic acid-containing inner leaflet lipids, through supporting membrane curvature, as demonstrated by comparative lipidomic analysis of mature versus immature B cell membranes. Targeted modification of membrane cholesterol and sphingolipid levels altered NT-forming capacity confirming these findings, and also highlighted that the actual lipid raft number may control NT-growth via defining the number of membrane-F-actin coupling sites. Atomic force microscopic mechano-manipulation experiments further proved that mechanical properties (elasticity or bending stiffness) of B cell NTs also depend on the actual membrane lipid composition. Data presented here highlight importance of the lipid side in controlling intercellular, nanotubular, regulatory communications in the immune system.
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Affiliation(s)
- Eszter A Tóth
- Department of Immunology, Eötvös Lorand University, Budapest, Hungary
| | - Ádám Oszvald
- Department of Immunology, Eötvös Lorand University, Budapest, Hungary
| | - Mária Péter
- Institute of Biochemistry, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, Hungary
| | - Gábor Balogh
- Institute of Biochemistry, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, Hungary.
| | | | - Tamás Bozó
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - Edina Szabó-Meleg
- Department of Biophysics, Medical Faculty, University of Pécs, Pécs, Hungary; Department of Szentágothai Research Center, University of Pécs, Pécs, Hungary
| | - Miklós Nyitrai
- Department of Biophysics, Medical Faculty, University of Pécs, Pécs, Hungary; Department of Szentágothai Research Center, University of Pécs, Pécs, Hungary
| | - Imre Derényi
- Department of Biological Physics, Eötvös Lorand University, Budapest, Hungary
| | - Miklós Kellermayer
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary; MTA-SE Molecular Biophysics Research Group, Semmelweis University, Budapest, Hungary
| | - Toshiyuki Yamaji
- Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Shunjuku-ku, Tokyo, Japan
| | - Kentaro Hanada
- Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Shunjuku-ku, Tokyo, Japan
| | - László Vígh
- Institute of Biochemistry, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, Hungary
| | - János Matkó
- Department of Immunology, Eötvös Lorand University, Budapest, Hungary.
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14
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Mouritsen OG, Bagatolli LA, Duelund L, Garvik O, Ipsen JH, Simonsen AC. Effects of seaweed sterols fucosterol and desmosterol on lipid membranes. Chem Phys Lipids 2017; 205:1-10. [PMID: 28365392 DOI: 10.1016/j.chemphyslip.2017.03.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 03/27/2017] [Accepted: 03/27/2017] [Indexed: 12/14/2022]
Abstract
Higher sterols are universally present in large amounts (20-30%) in the plasma membranes of all eukaryotes whereas they are universally absent in prokaryotes. It is remarkable that each kingdom of the eukaryotes has chosen, during the course of evolution, its preferred sterol: cholesterol in animals, ergosterol in fungi and yeast, phytosterols in higher plants, and e.g., fucosterol and desmosterol in algae. The question arises as to which specific properties do sterols impart to membranes and to which extent do these properties differ among the different sterols. Using a range of biophysical techniques, including calorimetry, fluorescence microscopy, vesicle-fluctuation analysis, and atomic force microscopy, we have found that fucosterol and desmosterol, found in red and brown macroalgae (seaweeds), similar to cholesterol support liquid-ordered membrane phases and induce coexistence between liquid-ordered and liquid-disordered domains in lipid bilayers. Fucosterol and desmosterol induce acyl-chain order in liquid membranes, but less effectively than cholesterol and ergosterol in the order: cholesterol>ergosterol>desmosterol>fucosterol, possibly reflecting the different molecular structure of the sterols at the hydrocarbon tail.
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Affiliation(s)
- Ole G Mouritsen
- MEMPHYS - Center for Biomembrane Physics, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.
| | - Luis A Bagatolli
- MEMPHYS - Center for Biomembrane Physics, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark; Yachay EP and Yachay Tech, Yachay City of Knowledge, Ecuador(1)
| | - Lars Duelund
- MEMPHYS - Center for Biomembrane Physics, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Olav Garvik
- MEMPHYS - Center for Biomembrane Physics, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - John H Ipsen
- MEMPHYS - Center for Biomembrane Physics, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Adam Cohen Simonsen
- MEMPHYS - Center for Biomembrane Physics, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
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15
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Bassereau P, Sorre B, Lévy A. Bending lipid membranes: experiments after W. Helfrich's model. Adv Colloid Interface Sci 2014; 208:47-57. [PMID: 24630341 DOI: 10.1016/j.cis.2014.02.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 02/02/2014] [Accepted: 02/03/2014] [Indexed: 10/25/2022]
Abstract
Current description of biomembrane mechanics originates for a large part from W. Helfrich's model. Based on his continuum theory, many experiments have been performed in the past four decades on simplified membranes in order to characterize the mechanical properties of lipid membranes and the contribution of polymers or proteins. The long-term goal was to develop a better understanding of the mechanical properties of cell membranes. In this paper, we will review representative experimental approaches that were developed during this period and the main results that were obtained.
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16
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Nagle JF, Jablin MS, Tristram-Nagle S, Akabori K. What are the true values of the bending modulus of simple lipid bilayers? Chem Phys Lipids 2014; 185:3-10. [PMID: 24746555 DOI: 10.1016/j.chemphyslip.2014.04.003] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 03/21/2014] [Accepted: 04/05/2014] [Indexed: 01/02/2023]
Abstract
Values of the bending modulus KC are reviewed, and possible causes for the considerable differences are discussed. One possible cause is the use of glucose and sucrose in the classical micromechanical manipulation and shape analysis methods. New data, using the more recent low angle X-ray method, are presented that do not support an effect of glucose or sucrose on KC. Another possible cause is using an incomplete theory to interpret the data. Adding a tilt term to the theory clearly does not affect the value obtained from the shape analysis method. It is shown that a tilt term, using a value of the modulus Kθ indicated by simulations, theory, and estimated from order parameters obtained from NMR and from the wide angle X-ray method, should also not affect the value obtained using the micromechanical manipulation method, although it does require a small correction when determining the value of the area compressibility modulus KA. It is still being studied whether including a tilt term will significantly affect the values of KC obtained using low angle X-ray data. It remains unclear what causes the differences in the experimental values of KC for simple lipid bilayers.
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Affiliation(s)
- John F Nagle
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
| | - Michael S Jablin
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | | | - Kiyotaka Akabori
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213, USA
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17
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Bagatolli LA, Needham D. Quantitative optical microscopy and micromanipulation studies on the lipid bilayer membranes of giant unilamellar vesicles. Chem Phys Lipids 2014; 181:99-120. [PMID: 24632023 DOI: 10.1016/j.chemphyslip.2014.02.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 02/25/2014] [Accepted: 02/26/2014] [Indexed: 12/01/2022]
Abstract
This manuscript discusses basic methodological aspects of optical microscopy and micromanipulation methods to study membranes and reviews methods to generate giant unilamellar vesicles (GUVs). In particular, we focus on the use of fluorescence microscopy and micropipet manipulation techniques to study composition-structure-property materials relationships of free-standing lipid bilayer membranes. Because their size (∼5-100 μm diameter) that is well above the resolution limit of regular light microscopes, GUVs are suitable membrane models for optical microscopy and micromanipulation experimentation. For instance, using different fluorescent reporters, fluorescence microscopy allows strategies to study membrane lateral structure/dynamics at the level of single vesicles of diverse compositions. The micropipet manipulation technique on the other hand, uses Hoffman modulation contrast microscopy and allows studies on the mechanical, thermal, molecular exchange and adhesive-interactive properties of compositionally different membranes under controlled environmental conditions. The goal of this review is to (i) provide a historical perspective for both techniques; (ii) present and discuss some of their most important contributions to our understanding of lipid bilayer membranes; and (iii) outline studies that would utilize both techniques simultaneously on the same vesicle thus bringing the ability to characterize structure and strain responses together with the direct application of well-defined stresses to a single membrane or observe the effects of adhesive spreading. Knowledge gained by these studies has informed several applications of lipid membranes including their use as lung surfactants and drug delivery systems for cancer.
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Affiliation(s)
- Luis A Bagatolli
- Membrane Biophysics and Biophotonics Group/MEMPHYS - Center for Biomembrane Physics, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark.
| | - David Needham
- DNRF Niels Bohr Professorship, Center for Single Particle Science and Engineering, Institute for Physics, Chemistry and Pharmacy, University of Southern Denmark, Odense, Denmark; Department of Mechanical Engineering and Material Science, Duke University, Durham, NC, USA
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