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Chng CP, Dowd A, Mechler A, Hsia KJ. Molecular dynamics simulations reliably identify vibrational modes in far-IR spectra of phospholipids. Phys Chem Chem Phys 2024; 26:18715-18726. [PMID: 38932689 DOI: 10.1039/d4cp00521j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2024]
Abstract
The properties of self-assembled phospholipid membranes are of essential importance in biochemistry and physical chemistry, providing a platform for many cellular life functions. Far-infrared (far-IR) vibrational spectroscopy, on the other hand, is a highly information-rich method to characterize intermolecular interactions and collective behaviour of lipids that can help explain, e.g., chain packing, thermodynamic phase behaviour, and sequestration. However, reliable interpretation of the far-IR spectra is still lacking. Here we present a molecular dynamics (MD) based approach to simulate vibrational modes of individual lipids and in an ensemble. The results are a good match to synchrotron far-IR measurements and enable identification of the molecular motions corresponding to each vibrational mode, thus allowing the correct interpretation of membrane spectra with high accuracy and resolving the longstanding ambiguities in the literature in this regard. Our results demonstrate the feasibility of using MD simulations for interpreting far-IR spectra broadly, opening new avenues for practical use of this powerful method.
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Affiliation(s)
- Choon-Peng Chng
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798, Republic of Singapore.
| | - Annette Dowd
- School of Mathematical and Physical Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Adam Mechler
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria 3086, Australia.
| | - K Jimmy Hsia
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore 639798, Republic of Singapore.
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637459, Republic of Singapore
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2
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Li M, Xing X, Yuan J, Zeng Z. Research progress on the regulatory role of cell membrane surface tension in cell behavior. Heliyon 2024; 10:e29923. [PMID: 38720730 PMCID: PMC11076917 DOI: 10.1016/j.heliyon.2024.e29923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 04/17/2024] [Accepted: 04/17/2024] [Indexed: 05/12/2024] Open
Abstract
Cell membrane surface tension has emerged as a pivotal biophysical factor governing cell behavior and fate. This review systematically delineates recent advances in techniques for cell membrane surface tension quantification, mechanosensing mechanisms, and regulatory roles of cell membrane surface tension in modulating major cellular processes. Micropipette aspiration, tether pulling, and newly developed fluorescent probes enable the measurement of cell membrane surface tension with spatiotemporal precision. Cells perceive cell membrane surface tension via conduits including mechanosensitive ion channels, curvature-sensing proteins (e.g. BAR domain proteins), and cortex-membrane attachment proteins (e.g. ERM proteins). Through membrane receptors like integrins, cells convert mechanical cues into biochemical signals. This conversion triggers cytoskeletal remodeling and extracellular matrix interactions in response to environmental changes. Elevated cell membrane surface tension suppresses cell spreading, migration, and endocytosis while facilitating exocytosis. Moreover, reduced cell membrane surface tension promotes embryonic stem cell differentiation and cancer cell invasion, underscoring cell membrane surface tension as a regulator of cell plasticity. Outstanding questions remain regarding cell membrane surface tension regulatory mechanisms and roles in tissue development/disease in vivo. Emerging tools to manipulate cell membrane surface tension with high spatiotemporal control in combination with omics approaches will facilitate the elucidation of cell membrane surface tension-mediated effects on signaling networks across various cell types/states. This will accelerate the development of cell membrane surface tension-based biomarkers and therapeutics for regenerative medicine and cancer. Overall, this review provides critical insights into cell membrane surface tension as a potent orchestrator of cell function, with broader impacts across mechanobiology.
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Affiliation(s)
- Manqing Li
- School of Public Health, Sun Yat-sen University, Guangzhou, 5180080, China
| | - Xiumei Xing
- School of Public Health, Sun Yat-sen University, Guangzhou, 5180080, China
| | - Jianhui Yuan
- Nanshan District Center for Disease Control and Prevention, Shenzhen, 518054, China
| | - Zhuoying Zeng
- The First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, Shenzhen University, Shenzhen, 518035, China
- Chemical Analysis & Physical Testing Institute, Shenzhen Center for Disease Control and Prevention, Shenzhen, 518055, China
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3
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Hossain MZ, Stroberg W. Bilayer tension-induced clustering of the UPR sensor IRE1. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184262. [PMID: 38081494 DOI: 10.1016/j.bbamem.2023.184262] [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: 05/24/2023] [Revised: 10/19/2023] [Accepted: 12/07/2023] [Indexed: 12/17/2023]
Abstract
The endoplasmic reticulum acts as a protein quality control center where a range of chaperones and foldases facilitates protein folding. IRE1 is a sensory transmembrane protein that transduces signals of proteotoxic stress by forming clusters and activating a cellular program called the unfolded protein response (UPR). Recently, membrane thickness variation due to membrane compositional changes have been shown to drive IRE1 cluster formation, activating the UPR even in the absence of proteotoxic stress. Here, we demonstrate a direct relationship between bilayer tension and UPR activation based on IRE1 dimer stability. The stability of the IRE1 dimer in a (50%DOPC-50%POPC) membrane at different applied bilayer tensions was analyzed via molecular dynamics simulations. The potential of mean force for IRE1 dimerization predicts a higher concentration of IRE1 dimers for both tensed and compressed ER membranes. This study shows that IRE1 may be a mechanosensitive membrane protein and establishes a direct biophysical relationship between bilayer tension and UPR activation.
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Affiliation(s)
- Md Zobayer Hossain
- Department of Mechanical Engineering, University of Alberta, 9211-116 Street NW, Edmonton, T6G 1H9, Alberta, Canada.
| | - Wylie Stroberg
- Department of Mechanical Engineering, University of Alberta, 9211-116 Street NW, Edmonton, T6G 1H9, Alberta, Canada.
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4
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Ahmed M, Billah MM, Tamba Y, Yamazaki M. Estimation of negative membrane tension in lipid bilayers and its effect on antimicrobial peptide magainin 2-induced pore formation. J Chem Phys 2024; 160:011101. [PMID: 38165103 DOI: 10.1063/5.0174288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 12/10/2023] [Indexed: 01/03/2024] Open
Abstract
Positive membrane tension in the stretched plasma membrane of cells and in the stretched lipid bilayer of vesicles has been well analyzed quantitatively, whereas there is limited quantitative information on negative membrane tension in compressed plasma membranes and lipid bilayers. Here, we examined negative membrane tension quantitatively. First, we developed a theory to describe negative membrane tension by analyzing the free energy of lipid bilayers to obtain a theoretical equation for negative membrane tension. This allowed us to obtain an equation describing the negative membrane tension (σosm) for giant unilamellar vesicles (GUVs) in hypertonic solutions due to negative osmotic pressure (Π). Then, we experimentally estimated the negative membrane tension for GUVs in hypertonic solutions by measuring the rate constant (kr) of rupture of the GUVs induced by the constant tension (σex) due to an external force as a function of σex. We found that larger σex values were required to induce the rupture of GUVs under negative Π compared with GUVs in isotonic solution and quantitatively determined the negative membrane tension induced by Π (σosm) by the difference between these σex values. At small negative Π, the experimental values of negative σosm agree with their theoretical values within experimental error, but as negative Π increases, the deviation increases. Negative tension increased the stability of GUVs because higher tensions were required for GUV rupture, and the rate constant of antimicrobial peptide magainin 2-induced pore formation decreased.
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Affiliation(s)
- Marzuk Ahmed
- Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Shizuoka 422-8529, Japan
| | - Md Masum Billah
- Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Shizuoka 422-8529, Japan
| | - Yukihiro Tamba
- General Education, National Institute of Technology, Suzuka College, Suzuka 510-0294, Japan
| | - Masahito Yamazaki
- Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Shizuoka 422-8529, Japan
- Nanomaterials Research Division, Research Institute of Electronics, Shizuoka University, Shizuoka 422-8529, Japan
- Department of Physics, Faculty of Science, Shizuoka University, Shizuoka 422-8529, Japan
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5
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Huang Y, Chandran Suja V, Yang M, Malkovskiy AV, Tandon A, Colom A, Qin J, Fuller GG. Interfacial stresses on droplet interface bilayers using two photon fluorescence lifetime imaging microscopy. J Colloid Interface Sci 2024; 653:1196-1204. [PMID: 37793246 DOI: 10.1016/j.jcis.2023.09.092] [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: 07/23/2023] [Revised: 09/06/2023] [Accepted: 09/14/2023] [Indexed: 10/06/2023]
Abstract
HYPOTHESIS Response of lipid bilayers to external mechanical stimuli is an active area of research with implications for fundamental and synthetic cell biology. Developing novel tools for systematically imposing mechanical strains and non-invasively mapping out interfacial (membrane) stress distributions on lipid bilayers can accelerate research in this field. EXPERIMENTS We report a miniature platform to manipulate model cell membranes in the form of droplet interface bilayers (DIBs), and non-invasively measure spatio-temporally resolved interfacial stresses using two photon fluorescence lifetime imaging of an interfacially active molecular flipper (Flipper-TR). We established the effectiveness of the developed framework by investigating interfacial stresses accompanying three key processes associated with DIBs: thin film drainage between lipid monolayer coated droplets, bilayer formation, and bilayer separation. FINDINGS The measurements revealed fundamental aspects of DIBs including the existence of a radially decaying interfacial stress distribution post bilayer formation, and the simultaneous build up and decay of stress respectively at the bilayer corner and center during bilayer separation. Finally, utilizing interfacial rheology measurements and MD simulations, we also reveal that the tested molecular flipper is sensitive to membrane fluidity that changes with interfacial stress - expanding the scientific understanding of how molecular flippers sense stress.
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Affiliation(s)
- Yaoqi Huang
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Vineeth Chandran Suja
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA; School of Engineering and Applied Sciences, Harvard University, MA - 02138, USA.
| | - Menghao Yang
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Andrey V Malkovskiy
- Carnegie Institute for Science, Department of Plant Biology, Stanford CA 94305, USA
| | - Arnuv Tandon
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Adai Colom
- Biofisika Institute (CSIC, UPV/EHU), 48940 Leioa, Spain; Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, Campus Universitario, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain
| | - Jian Qin
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Gerald G Fuller
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA.
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Singh G, Venkataramaraju Y, Meher G, Sahu BS, Saleem M, Akhter Y. Distinct membrane perturbation effects of Catestatin and its CST-364 S variant: Insights from molecular simulations and anisotropy measurements. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184238. [PMID: 37844772 DOI: 10.1016/j.bbamem.2023.184238] [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: 07/11/2023] [Revised: 09/27/2023] [Accepted: 10/09/2023] [Indexed: 10/18/2023]
Abstract
Catestatin (CST), a versatile 21 amino acid long cationic peptide, is stored in chromaffin granules and exocytosed upon fusion with the plasma membrane. CST, produced by chromaffin cells and neutrophils, is derived from the processing of chromogranin A and induced in the skin after injury. It involves catecholamine inhibition, blood pressure control, inflammation, and innate immunity. It is thought that calcium influx is triggered by CST permeating within neutrophils. It is unknown whether CST can disturb the immediate environment enough to penetrate the cell membrane passively. We used molecular dynamics simulations to examine the behaviour of human CST in its wild-type state (CST WT) and one of its naturally occurring variants, CST-364 S, which has a high allelic frequency in the human population. Both peptides were incorporated into the model eukaryotic cell membrane known as the POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine) lipid bilayer. The molecular modelling and simulations results show that CST WT and CST-364 S have different propensities for membrane disruption. It was shown that CST-364 S has higher membrane permeability than CST WT. In addition, we have used fluorescence anisotropy and leakage assay to study the interaction of peptides with PC membranes. Both peptides interacted with POPC and DOPC membranes, while CST-364 S penetrated the membrane more deeply via disorganizing the membrane interface, which supports our previous findings. According to this study, there is a good possibility that the peptides will passively permeate the cell membrane, distort, and pass through it.
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Affiliation(s)
- Garima Singh
- Department of Biotechnology, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow 226025, Uttar Pradesh, India
| | | | - Geetanjali Meher
- School of Biological Sciences, National Institute of Science Education & Research, Bhubaneshwar, India
| | - Bhavani Shankar Sahu
- National Brain Research Centre, NH-8, Manesar, Gurugram, Haryana 122 052, India.
| | - Mohammed Saleem
- School of Biological Sciences, National Institute of Science Education & Research, Bhubaneshwar, India.
| | - Yusuf Akhter
- Department of Biotechnology, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow 226025, Uttar Pradesh, India.
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7
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Radhakrishnan S, Nair KS, Nandi S, Bajaj H. Engineering semi-permeable giant liposomes. Chem Commun (Camb) 2023; 59:13863-13866. [PMID: 37930322 DOI: 10.1039/d3cc04039a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2023]
Abstract
Giant unilamellar vesicles (GUVs) with a semi-permeable nature are prerequisites for constructing synthetic cells. Here we engineer semi-permeable GUVs by the inclusion of DOTAP lipid in vesicles. Diffusion of molecules of different charge and size across GUVs are reported. Control over size-selective permeability is demonstrated by modulating the DOTAP lipid composition in different lipid systems without reconstituting membrane proteins. Such semi-permeable GUVs have immense applications for constructing synthetic cells.
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Affiliation(s)
- Sreelakshmi Radhakrishnan
- Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (NIIST), Trivandrum 695019, Kerala, India.
| | - Karthika S Nair
- Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (NIIST), Trivandrum 695019, Kerala, India.
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Human Resource Development Centre, Ghaziabad 201002, India
| | - Samir Nandi
- Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (NIIST), Trivandrum 695019, Kerala, India.
| | - Harsha Bajaj
- Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (NIIST), Trivandrum 695019, Kerala, India.
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Human Resource Development Centre, Ghaziabad 201002, India
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8
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Ghorbani M, Dehghan G, Allahverdi A. Insight into the effect of ibuprofen on the permeability of the membrane: a molecular dynamic simulation study. J Biomol Struct Dyn 2023:1-11. [PMID: 37982256 DOI: 10.1080/07391102.2023.2283151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 11/06/2023] [Indexed: 11/21/2023]
Abstract
Studying interactions between drugs and cell membranes is of great interest to designing novel drugs, optimizing drug delivery, and discerning drug mechanism action. In this study, we investigated the physical properties of the bilayer membrane model of POPC upon interaction with ibuprofen (IBU) using molecular dynamics simulations. The area per lipid (APL) was calculated to describe the effect of ibuprofen on the packing properties of the lipid bilayer. The APL was 0.58 nm2 and 0.63 nm2 for the membrane in low and high IBU respectively, and 0.57 nm2 for the membrane without IBU. Our finding showed that the mean square deviation (MSD) increased with increased ibuprofen content. In addition, the order parameter for the hydrocarbon chain of lipids increased with increased ibuprofen content. There was an increment in the transfer free energy after the head group region while it was maximum in the hydrophobic core for hydrogen peroxide (H2O2) (∼6.2 kcal.mol-1) and H2O (∼3.4 kcal.mol-1) which then decreased to respective values of (∼4.6 kcal.mol-1), and (∼2.3 kcal.mol-1) at the center of the bilayer in the presence of IBU. It seems that in the presence of ibuprofen, the free energy profile of the permeability of water and H2O2 significantly decreased. These findings show that ibuprofen significantly influences the physical properties of the bilayer by decreasing the packing and intermolecular interaction in the hydrocarbon chain region and increasing the water permeability of the bilayer. These results may provide insights into the local cytotoxic side effects of ibuprofen and its underlying molecular mechanisms.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
| | | | - Abdollah Allahverdi
- Department of Biophysics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
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9
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Manafirad A, Menendez CA, Perez-Lemus GR, Thayumanavan S, de Pablo JJ, Dinsmore AD. Structural and Mechanical Response of Two-Component Photoswitchable Lipid Bilayer Vesicles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:15932-15941. [PMID: 37922483 DOI: 10.1021/acs.langmuir.3c01764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2023]
Abstract
Optical control of phospholipids is an attractive option for the rapid, reversible, and tunable manipulation of membrane structure and dynamics. Azo-PC, a lipid with an azobenzene group within one acyl chain, undergoes a light-induced trans-to-cis isomerization and thus arises as a powerful tool for manipulating lipid order and dynamics. Here, we report on vesicle-scale micropipette measurements and atomistic simulations to probe the elastic stretching modulus, water permeability, toughness, thickness, and membrane area upon isomerization. We investigated both dynamics and steady-state properties. In pure azo-PC membranes, we found that the molecular area in trans was 16% smaller than that in cis, the membrane's stretching modulus kA was 2.5 ± 0.3 times greater, and the water permeability PW was 3.5 ± 0.5 times smaller. We also studied mixtures of azo-PC with the miscible, unsaturated lipid DOPC. Atomistic molecular dynamics simulations show how the membrane thickness, chain order, and correlations across membrane leaflets explain the experimental data. Together, these data show how one rotating bond changes the molecular- and membrane-scale properties. These results will be useful for photopharmacology and for developing new materials whose permeability, elasticity, and toughness may be switched on demand.
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Affiliation(s)
- Arash Manafirad
- Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003, United States
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Cintia A Menendez
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
- INQUISUR, Departamento de Quimica, Universidad Nacional del Sur (UNS)-CONICET, Avenida Alem 1253, 8000 Bahía Blanca, Argentina
| | - Gustavo R Perez-Lemus
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - S Thayumanavan
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Juan J de Pablo
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Anthony D Dinsmore
- Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003, United States
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10
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Abdelmessih R, Xu J, Hung FR, Auguste DT. Integration of an LPAR1 Antagonist into Liposomes Enhances Their Internalization and Tumor Accumulation in an Animal Model of Human Metastatic Breast Cancer. Mol Pharm 2023; 20:5500-5514. [PMID: 37844135 PMCID: PMC10631474 DOI: 10.1021/acs.molpharmaceut.3c00348] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 09/29/2023] [Accepted: 10/02/2023] [Indexed: 10/18/2023]
Abstract
Lysophosphatidic acid receptor 1 (LPAR1) is elevated in breast cancer. The deregulation of LPAR1, including the function and level of expression, is linked to cancer initiation, progression, and metastasis. LPAR1 antagonists, AM095 or Ki16425, may be effective therapeutic molecules, yet their limited water solubility hinders in vivo delivery. In this study, we report on the synthesis of two liposomal formulations incorporating AM095 or Ki16425, embedded within the lipid bilayer, as targeted nanocarriers for metastatic breast cancer (MBC). The data show that the Ki16425 liposomal formulation exhibited a 50% increase in internalization by MBC mouse epithelial cells (4T1) and a 100% increase in tumor accumulation in a mouse model of MBC compared with that of a blank liposomal formulation (control). At the same time, normal mouse epithelial cells (EpH-4Ev) internalized the Ki16425 liposomal formulation 25% lesser than the control formulation. Molecular dynamics simulations show that the integration of AM095 or Ki16425 modified the physical and mechanical properties of the lipid bilayer, making it more flexible in these liposomal formulations compared with liposomes without drug. The incorporation of an LPAR1 antagonist within a liposomal drug delivery system represents a viable therapeutic approach for targeting the LPA-LPAR1 axis, which may hinder the progression of MBC.
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Affiliation(s)
- Rudolf
G. Abdelmessih
- Department of Chemical Engineering, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115, United States
| | - Jiaming Xu
- Department of Chemical Engineering, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115, United States
| | - Francisco R. Hung
- Department of Chemical Engineering, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115, United States
| | - Debra T. Auguste
- Department of Chemical Engineering, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115, United States
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11
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Xin Y, Li K, Huang M, Liang C, Siemann D, Wu L, Tan Y, Tang X. Biophysics in tumor growth and progression: from single mechano-sensitive molecules to mechanomedicine. Oncogene 2023; 42:3457-3490. [PMID: 37864030 PMCID: PMC10656290 DOI: 10.1038/s41388-023-02844-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 09/08/2023] [Accepted: 09/15/2023] [Indexed: 10/22/2023]
Abstract
Evidence from physical sciences in oncology increasingly suggests that the interplay between the biophysical tumor microenvironment and genetic regulation has significant impact on tumor progression. Especially, tumor cells and the associated stromal cells not only alter their own cytoskeleton and physical properties but also remodel the microenvironment with anomalous physical properties. Together, these altered mechano-omics of tumor tissues and their constituents fundamentally shift the mechanotransduction paradigms in tumorous and stromal cells and activate oncogenic signaling within the neoplastic niche to facilitate tumor progression. However, current findings on tumor biophysics are limited, scattered, and often contradictory in multiple contexts. Systematic understanding of how biophysical cues influence tumor pathophysiology is still lacking. This review discusses recent different schools of findings in tumor biophysics that have arisen from multi-scale mechanobiology and the cutting-edge technologies. These findings range from the molecular and cellular to the whole tissue level and feature functional crosstalk between mechanotransduction and oncogenic signaling. We highlight the potential of these anomalous physical alterations as new therapeutic targets for cancer mechanomedicine. This framework reconciles opposing opinions in the field, proposes new directions for future cancer research, and conceptualizes novel mechanomedicine landscape to overcome the inherent shortcomings of conventional cancer diagnosis and therapies.
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Grants
- R35 GM150812 NIGMS NIH HHS
- This work was financially supported by National Natural Science Foundation of China (Project no. 11972316, Y.T.), Shenzhen Science and Technology Innovation Commission (Project no. JCYJ20200109142001798, SGDX2020110309520303, and JCYJ20220531091002006, Y.T.), General Research Fund of Hong Kong Research Grant Council (PolyU 15214320, Y. T.), Health and Medical Research Fund (HMRF18191421, Y.T.), Hong Kong Polytechnic University (1-CD75, 1-ZE2M, and 1-ZVY1, Y.T.), the Cancer Pilot Research Award from UF Health Cancer Center (X. T.), the National Institute of General Medical Sciences of the National Institutes of Health under award number R35GM150812 (X. T.), the National Science Foundation under grant number 2308574 (X. T.), the Air Force Office of Scientific Research under award number FA9550-23-1-0393 (X. T.), the University Scholar Program (X. T.), UF Research Opportunity Seed Fund (X. T.), the Gatorade Award (X. T.), and the National Science Foundation REU Site at UF: Engineering for Healthcare (Douglas Spearot and Malisa Sarntinoranont). We are deeply grateful for the insightful discussions with and generous support from all members of Tang (UF)’s and Tan (PolyU)’s laboratories and all staff members of the MAE/BME/ECE/Health Cancer Center at UF and BME at PolyU.
- National Natural Science Foundation of China (National Science Foundation of China)
- Shenzhen Science and Technology Innovation Commission
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Affiliation(s)
- Ying Xin
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China
| | - Keming Li
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China
| | - Miao Huang
- Department of Mechanical and Aerospace Engineering, Herbert Wertheim College of Engineering, University of Florida, Gainesville, FL, USA
| | - Chenyu Liang
- Department of Mechanical and Aerospace Engineering, Herbert Wertheim College of Engineering, University of Florida, Gainesville, FL, USA
| | - Dietmar Siemann
- UF Health Cancer Center, University of Florida, Gainesville, FL, USA
| | - Lizi Wu
- UF Health Cancer Center, University of Florida, Gainesville, FL, USA
| | - Youhua Tan
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China.
- Department of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong, China.
- Research Institute of Smart Ageing, The Hong Kong Polytechnic University, Hong Kong, China.
| | - Xin Tang
- Department of Mechanical and Aerospace Engineering, Herbert Wertheim College of Engineering, University of Florida, Gainesville, FL, USA.
- UF Health Cancer Center, University of Florida, Gainesville, FL, USA.
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA.
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, USA.
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12
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Zheng H, Li H, Li M, Zhai T, Xie X, Li C, Jing X, Liang C, Li Q, Zuo X, Li J, Fan J, Shen J, Peng X, Fan C. A Membrane Tension-Responsive Mechanosensitive DNA Nanomachine. Angew Chem Int Ed Engl 2023; 62:e202305896. [PMID: 37438325 DOI: 10.1002/anie.202305896] [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: 04/27/2023] [Revised: 07/11/2023] [Accepted: 07/12/2023] [Indexed: 07/14/2023]
Abstract
Membrane curvature reflects physical forces operating on the lipid membrane, which plays important roles in cellular processes. Here, we design a mechanosensitive DNA (MSD) nanomachine that mimics natural mechanosensitive PIEZO channels to convert the membrane tension changes of lipid vesicles with different sizes into fluorescence signals in real time. The MSD nanomachine consists of an archetypical six-helix-bundle DNA nanopore, cholesterol-based membrane anchors, and a solvatochromic fluorophore, spiropyran (SP). We find that the DNA nanopore effectively amplifies subtle variations of the membrane tension, which effectively induces the isomerization of weakly emissive SP into highly emissive merocyanine isomers for visualizing membrane tension changes. By measuring the membrane tension via the fluorescence of MSD nanomachine, we establish the correlation between the membrane tension and the curvature that follows the Young-Laplace equation. This DNA nanotechnology-enabled strategy opens new routes to studying membrane mechanics in physiological and pathological settings.
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Affiliation(s)
- Haoran Zheng
- School of Chemistry and Chemical Engineering, New Cornerstone Science Laboratory, Frontiers Science Center for Transformative Molecules and National Center for Translational Medicine, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Haidong Li
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, 116024, China
| | - Mingqiang Li
- School of Chemistry and Chemical Engineering, New Cornerstone Science Laboratory, Frontiers Science Center for Transformative Molecules and National Center for Translational Medicine, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Tingting Zhai
- School of Chemistry and Chemical Engineering, New Cornerstone Science Laboratory, Frontiers Science Center for Transformative Molecules and National Center for Translational Medicine, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xiaodong Xie
- School of Chemistry and Chemical Engineering, New Cornerstone Science Laboratory, Frontiers Science Center for Transformative Molecules and National Center for Translational Medicine, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Cong Li
- School of Chemistry and Chemical Engineering, New Cornerstone Science Laboratory, Frontiers Science Center for Transformative Molecules and National Center for Translational Medicine, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xinxin Jing
- School of Chemistry and Chemical Engineering, New Cornerstone Science Laboratory, Frontiers Science Center for Transformative Molecules and National Center for Translational Medicine, Shanghai Jiao Tong University, Shanghai, 200240, China
- Institute of Molecular Medicine, Shanghai Key Laboratory for Nucleic Acids Chemistry and Nanomedicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Chengpin Liang
- School of Chemistry and Chemical Engineering, New Cornerstone Science Laboratory, Frontiers Science Center for Transformative Molecules and National Center for Translational Medicine, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Qian Li
- School of Chemistry and Chemical Engineering, New Cornerstone Science Laboratory, Frontiers Science Center for Transformative Molecules and National Center for Translational Medicine, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xiaolei Zuo
- Institute of Molecular Medicine, Shanghai Key Laboratory for Nucleic Acids Chemistry and Nanomedicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Jiang Li
- Institute of Materiobiology, Department of Chemistry, College of Science, Shanghai University, Shanghai, 200444, China
| | - Jiangli Fan
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, 116024, China
- Ningbo Institute of Dalian University of Technology, Ningbo, 315016, China
| | - Jianlei Shen
- School of Chemistry and Chemical Engineering, New Cornerstone Science Laboratory, Frontiers Science Center for Transformative Molecules and National Center for Translational Medicine, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xiaojun Peng
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, 116024, China
| | - Chunhai Fan
- School of Chemistry and Chemical Engineering, New Cornerstone Science Laboratory, Frontiers Science Center for Transformative Molecules and National Center for Translational Medicine, Shanghai Jiao Tong University, Shanghai, 200240, China
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13
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Whiting R, Stanton S, Kucheriava M, Smith AR, Pitts M, Robertson D, Kammer J, Li Z, Fologea D. Hypo-Osmotic Stress and Pore-Forming Toxins Adjust the Lipid Order in Sheep Red Blood Cell Membranes. MEMBRANES 2023; 13:620. [PMID: 37504986 PMCID: PMC10385129 DOI: 10.3390/membranes13070620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 06/07/2023] [Accepted: 06/22/2023] [Indexed: 07/29/2023]
Abstract
Lipid ordering in cell membranes has been increasingly recognized as an important factor in establishing and regulating a large variety of biological functions. Multiple investigations into lipid organization focused on assessing ordering from temperature-induced phase transitions, which are often well outside the physiological range. However, particular stresses elicited by environmental factors, such as hypo-osmotic stress or protein insertion into membranes, with respect to changes in lipid status and ordering at constant temperature are insufficiently described. To fill these gaps in our knowledge, we exploited the well-established ability of environmentally sensitive membrane probes to detect intramembrane changes at the molecular level. Our steady state fluorescence spectroscopy experiments focused on assessing changes in optical responses of Laurdan and diphenylhexatriene upon exposure of red blood cells to hypo-osmotic stress and pore-forming toxins at room temperature. We verified our utilized experimental systems by a direct comparison of the results with prior reports on artificial membranes and cholesterol-depleted membranes undergoing temperature changes. The significant changes observed in the lipid order after exposure to hypo-osmotic stress or pore-forming toxins resembled phase transitions of lipids in membranes, which we explained by considering the short-range interactions between membrane components and the hydrophobic mismatch between membrane thickness and inserted proteins. Our results suggest that measurements of optical responses from the membrane probes constitute an appropriate method for assessing the status of lipids and phase transitions in target membranes exposed to mechanical stresses or upon the insertion of transmembrane proteins.
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Affiliation(s)
- Rose Whiting
- Department of Physics, Boise State University, Boise, ID 83725, USA
- Biomolecular Sciences Graduate Program, Boise State University, Boise, ID 83725, USA
| | - Sevio Stanton
- Department of Physics, Boise State University, Boise, ID 83725, USA
| | | | - Aviana R Smith
- Department of Physics, Boise State University, Boise, ID 83725, USA
| | - Matt Pitts
- Department of Physics, Boise State University, Boise, ID 83725, USA
- Biomolecular Sciences Graduate Program, Boise State University, Boise, ID 83725, USA
| | - Daniel Robertson
- Department of Physics, Boise State University, Boise, ID 83725, USA
| | - Jacob Kammer
- Department of Physics, Boise State University, Boise, ID 83725, USA
- Department of Family Medicine, Idaho College of Osteopathic Medicine, Meridian, ID 83642, USA
| | - Zhiyu Li
- Department of Physics, Boise State University, Boise, ID 83725, USA
| | - Daniel Fologea
- Department of Physics, Boise State University, Boise, ID 83725, USA
- Biomolecular Sciences Graduate Program, Boise State University, Boise, ID 83725, USA
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14
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Frewein MPK, Piller P, Semeraro EF, Czakkel O, Gerelli Y, Porcar L, Pabst G. Distributing aminophospholipids asymmetrically across leaflets causes anomalous membrane stiffening. Biophys J 2023; 122:2445-2455. [PMID: 37120716 PMCID: PMC10322881 DOI: 10.1016/j.bpj.2023.04.025] [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: 12/22/2022] [Revised: 03/10/2023] [Accepted: 04/25/2023] [Indexed: 05/01/2023] Open
Abstract
We studied the mechanical leaflet coupling of prototypic mammalian plasma membranes using neutron spin-echo spectroscopy. In particular, we examined a series of asymmetric phospholipid vesicles with phosphatidylcholine and sphingomyelin enriched in the outer leaflet and inner leaflets composed of phosphatidylethanolamine/phosphatidylserine mixtures. The bending rigidities of most asymmetric membranes were anomalously high, exceeding even those of symmetric membranes formed from their cognate leaflets. Only asymmetric vesicles with outer leaflets enriched in sphingolipid displayed bending rigidities in conformity with these symmetric controls. We performed complementary small-angle neutron and x-ray experiments on the same vesicles to examine possible links to structural coupling mechanisms, which would show up in corresponding changes in membrane thickness. In addition, we estimated differential stress between leaflets originating either from a mismatch of their lateral areas or spontaneous curvatures. However, no correlation with asymmetry-induced membrane stiffening was observed. To reconcile our findings, we speculate that an asymmetric distribution of charged or H-bond forming lipids may induce an intraleaflet coupling, which increases the weight of hard undulatory modes of membrane fluctuations and hence the overall membrane stiffness.
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Affiliation(s)
- Moritz P K Frewein
- Biophysics, Institute of Molecular Biosciences, University of Graz, NAWI Graz, Graz, Austria; Institut Laue-Langevin, Grenoble, France; BioTechMed Graz, Graz, Austria; Field of Excellence BioHealth, Graz, Austria
| | - Paulina Piller
- Biophysics, Institute of Molecular Biosciences, University of Graz, NAWI Graz, Graz, Austria; BioTechMed Graz, Graz, Austria; Field of Excellence BioHealth, Graz, Austria
| | - Enrico F Semeraro
- Biophysics, Institute of Molecular Biosciences, University of Graz, NAWI Graz, Graz, Austria; BioTechMed Graz, Graz, Austria; Field of Excellence BioHealth, Graz, Austria
| | | | - Yuri Gerelli
- CNR Institute for Complex Systems, Uos Sapienza, Roma, Italy; Department of Physics, Sapienza University of Rome, Roma, Italy
| | | | - Georg Pabst
- Biophysics, Institute of Molecular Biosciences, University of Graz, NAWI Graz, Graz, Austria; BioTechMed Graz, Graz, Austria; Field of Excellence BioHealth, Graz, Austria.
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15
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Baek JM, Jung WH, Yu ES, Ahn DJ, Ryu YS. In Vitro Membrane Platform for the Visualization of Water Impermeability across the Liquid-Ordered Phase under Hypertonic Conditions. J Am Chem Soc 2022; 144:21887-21896. [PMID: 36367984 DOI: 10.1021/jacs.2c06626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Passive water penetration across the cell membrane by osmotic diffusion is essential for the homeostasis of cell volume, in addition to the protein-assisted active transportation of water. Since membrane components can regulate water permeability, controlling compositional variation during the volume regulatory process is a prerequisite for investigating the underlying mechanisms of water permeation and related membrane dynamics. However, the lack of a viable in vitro membrane platform in hypertonic solutions impedes advanced knowledge of cell volume regulation processes, especially cholesterol-enriched lipid domains called lipid rafts. By reconstituting the liquid-ordered (Lo) domain as a likeness of lipid rafts, we verified suppressed water permeation across the Lo domains, which had yet to be confirmed with experimental demonstrations despite a simulation approach. With the help of direct transfer of the Lo domains from vesicles to supported lipid membranes, the biological roles of lipid composition in suppressed water translocation were experimentally confirmed. Additionally, the improvement in membrane stability under hypertonic conditions was demonstrated based on molecular dynamics simulations.
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Affiliation(s)
- Ji Min Baek
- Brain Science Institute, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea.,Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Woo Hyuk Jung
- Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Eui-Sang Yu
- Brain Science Institute, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Dong June Ahn
- Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Republic of Korea.,KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 02841, Republic of Korea
| | - Yong-Sang Ryu
- Brain Science Institute, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea.,KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 02841, Republic of Korea
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16
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Pittman M, Ali AM, Chen Y. How sticky? How Tight? How Hot? Imaging probes for fluid viscosity, membrane tension and temperature measurements at the cellular level. Int J Biochem Cell Biol 2022; 153:106329. [PMID: 36336304 PMCID: PMC10148659 DOI: 10.1016/j.biocel.2022.106329] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 10/22/2022] [Accepted: 10/31/2022] [Indexed: 11/06/2022]
Abstract
We review the progress made in imaging probes for three important physical parameters: viscosity, membrane tension, and temperature, all of which play important roles in many cellular processes. Recent evidences showed that cell migration speed can be modulated by extracellular fluid viscosity; membrane tension contributes to the regulation of cell motility, exo-/endo-cytosis, and cell spread area; and temperature affects neural activity and adipocyte differentiation. We discuss the techniques implementing imaging-based probes to measure viscosity, membrane tension, and temperature at subcellular resolution dynamically. The merits and shortcomings of each technique are examined, and the future applications of the recently developed techniques are also explored.
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17
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Kariuki R, Penman R, Bryant SJ, Orrell-Trigg R, Meftahi N, Crawford RJ, McConville CF, Bryant G, Voïtchovsky K, Conn CE, Christofferson AJ, Elbourne A. Behavior of Citrate-Capped Ultrasmall Gold Nanoparticles on a Supported Lipid Bilayer Interface at Atomic Resolution. ACS NANO 2022; 16:17179-17196. [PMID: 36121776 DOI: 10.1021/acsnano.2c07751] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Nanomaterials have the potential to transform biological and biomedical research, with applications ranging from drug delivery and diagnostics to targeted interference of specific biological processes. Most existing research is aimed at developing nanomaterials for specific tasks such as enhanced biocellular internalization. However, fundamental aspects of the interactions between nanomaterials and biological systems, in particular, membranes, remain poorly understood. In this study, we provide detailed insights into the molecular mechanisms governing the interaction and evolution of one of the most common synthetic nanomaterials in contact with model phospholipid membranes. Using a combination of atomic force microscopy (AFM) and molecular dynamics (MD) simulations, we elucidate the precise mechanisms by which citrate-capped 5 nm gold nanoparticles (AuNPs) interact with supported lipid bilayers (SLBs) of pure fluid (DOPC) and pure gel-phase (DPPC) phospholipids. On fluid-phase DOPC membranes, the AuNPs adsorb and are progressively internalized as the citrate capping of the NPs is displaced by the surrounding lipids. AuNPs also interact with gel-phase DPPC membranes where they partially embed into the outer leaflet, locally disturbing the lipid organization. In both systems, the AuNPs cause holistic perturbations throughout the bilayers. AFM shows that the lateral diffusion of the particles is several orders of magnitude smaller than that of the lipid molecules, which creates some temporary scarring of the membrane surface. Our results reveal how functionalized AuNPs interact with differing biological membranes with mechanisms that could also have implications for cooperative membrane effects with other molecules.
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Affiliation(s)
- Rashad Kariuki
- School of Science, STEM College, RMIT University, Melbourne, VIC 3001, Australia
| | - Rowan Penman
- School of Science, STEM College, RMIT University, Melbourne, VIC 3001, Australia
| | - Saffron J Bryant
- School of Science, STEM College, RMIT University, Melbourne, VIC 3001, Australia
| | - Rebecca Orrell-Trigg
- School of Science, STEM College, RMIT University, Melbourne, VIC 3001, Australia
| | - Nastaran Meftahi
- ARC Centre of Excellence in Exciton Science, School of Science, RMIT University, Melbourne, VIC 3001, Australia
| | - Russell J Crawford
- School of Science, STEM College, RMIT University, Melbourne, VIC 3001, Australia
| | - Chris F McConville
- School of Science, STEM College, RMIT University, Melbourne, VIC 3001, Australia
- Deakin University, Geelong, VIC 3220, Australia
| | - Gary Bryant
- School of Science, STEM College, RMIT University, Melbourne, VIC 3001, Australia
| | - Kislon Voïtchovsky
- University of Durham, Physics Department, Durham DH1 3LE, United Kingdom
| | - Charlotte E Conn
- School of Science, STEM College, RMIT University, Melbourne, VIC 3001, Australia
| | - Andrew J Christofferson
- School of Science, STEM College, RMIT University, Melbourne, VIC 3001, Australia
- ARC Centre of Excellence in Exciton Science, School of Science, RMIT University, Melbourne, VIC 3001, Australia
| | - Aaron Elbourne
- School of Science, STEM College, RMIT University, Melbourne, VIC 3001, Australia
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18
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Recent Advances in Fluorescence Recovery after Photobleaching for Decoupling Transport and Kinetics of Biomacromolecules in Cellular Physiology. Polymers (Basel) 2022; 14:polym14091913. [PMID: 35567083 PMCID: PMC9105003 DOI: 10.3390/polym14091913] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 04/27/2022] [Accepted: 04/29/2022] [Indexed: 12/16/2022] Open
Abstract
Among the new molecular tools available to scientists and engineers, some of the most useful include fluorescently tagged biomolecules. Tools, such as green fluorescence protein (GFP), have been applied to perform semi-quantitative studies on biological signal transduction and cellular structural dynamics involved in the physiology of healthy and disease states. Such studies focus on drug pharmacokinetics, receptor-mediated endocytosis, nuclear mechanobiology, viral infections, and cancer metastasis. In 1976, fluorescence recovery after photobleaching (FRAP), which involves the monitoring of fluorescence emission recovery within a photobleached spot, was developed. FRAP allowed investigators to probe two-dimensional (2D) diffusion of fluorescently-labelled biomolecules. Since then, FRAP has been refined through the advancements of optics, charged-coupled-device (CCD) cameras, confocal microscopes, and molecular probes. FRAP is now a highly quantitative tool used for transport and kinetic studies in the cytosol, organelles, and membrane of a cell. In this work, the authors intend to provide a review of recent advances in FRAP. The authors include epifluorescence spot FRAP, total internal reflection (TIR)/FRAP, and confocal microscope-based FRAP. The underlying mathematical models are also described. Finally, our understanding of coupled transport and kinetics as determined by FRAP will be discussed and the potential for future advances suggested.
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19
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Press-Sandler O, Miller Y. Molecular insights into the primary nucleation of polymorphic amyloid β dimers in DOPC lipid bilayer membrane. Protein Sci 2022; 31:e4283. [PMID: 35129859 PMCID: PMC8994488 DOI: 10.1002/pro.4283] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 02/01/2022] [Accepted: 02/03/2022] [Indexed: 11/29/2022]
Abstract
Alzheimer's disease (AD) pathology is characterized by loss of memory cognitive and behavioral deterioration. One of the hallmarks of AD is amyloid β (Aβ) plaques in the brain that consists of Aβ oligomers and fibrils. It is accepted that oligomers, particularly dimers, are toxic species that are produced extracellularly and intracellularly in membranes. It is believed that the disruption of membranes by polymorphic Aβ oligomers is the key for the pathology of AD. This is a first study that investigate the effect of polymorphic “α‐helix/random coil” and “fibril‐like” Aβ dimers on 1,2‐dioleoyl‐sn‐glycero‐3‐phosphocholine (DOPC) membrane. It has been found that the DOPC membrane promotes Aβ1–42 “fibril‐like” dimers and impedes Aβ1–42 “α‐helix/random coil” dimers. The N‐termini domains within Aβ1–42 dimers play a role in Aβ aggregation in membrane milieus. In addition, the aromatic π–π interactions (involving residues F19 and F20 in Aβ1–42) are the driving forces for the hydrophobic interactions that initiate the primary nucleation of polymorphic Aβ1–42 dimers within DOPC membrane. Finally, the DOPC bilayer membrane thickness is locally decreased, and it is disrupted by an embedded distinct Aβ1–42 dimer, due to relatively large contacts between Aβ1–42 monomers and the DOPC membrane. This study reveals insights into the molecular mechanisms by which polymorphic early‐stage Aβ1–42 dimers have distinct impacts on DOPC membrane.
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Affiliation(s)
- Olga Press-Sandler
- Department of Chemistry, Ben-Gurion University of the Negev, P.O. Box 653, Be'er Sheva, Israel.,Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beér-Sheva, Israel
| | - Yifat Miller
- Department of Chemistry, Ben-Gurion University of the Negev, P.O. Box 653, Be'er Sheva, Israel.,Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beér-Sheva, Israel
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20
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McColman S, Li R, Osman S, Bishop A, Wilkie KP, Cramb DT. Serum proteins on nanoparticles: early stages of the "protein corona". NANOSCALE 2021; 13:20550-20563. [PMID: 34859798 DOI: 10.1039/d1nr06137b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Nanoparticles in biological systems such as the bloodstream are exposed to a complex solution of biomolecules. A "corona" monolayer of proteins has historically been thought to form on nanoparticles upon introduction into such environments. To examine the first steps of protein binding, Fluorescence Correlation/Cross Correlation Spectroscopy and Fluorescence Resonance Energy Transfer were used to directly analyze four different nanoparticle systems. CdSe/ZnS core/shell quantum dots, 100 nm diameter polystyrene fluospheres, 200 nm diameter polystyrene fluospheres, and 200 nm diameter PEG-grafted DOTAP liposomes were studied with respect to serum protein binding, using bovine serum albumin as a model. Surface heterogeneity is found to be a key factor in protein binding to these nanoparticles, and as such we present a novel conceptualization of the early hard corona as low-ratio, non-uniform binding rather than a uniform monolayer.
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Affiliation(s)
- Sarah McColman
- Department of Chemistry and Biology, Faculty of Science, Ryerson University, 350 Victoria Street, Toronto ON M5B 2 K3, Canada.
- Institute for Biomedical Engineering, Science, and Technology (iBEST), Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, 209 Victoria Street, Toronto ON M5B 1 T8, Canada
- Department of Chemistry, Faculty of Science, University of Calgary, 2500 University Dr NW, Calgary, AB T2N 1N4, Canada
| | - Rui Li
- Department of Chemistry, Faculty of Science, University of Calgary, 2500 University Dr NW, Calgary, AB T2N 1N4, Canada
| | - Selena Osman
- Department of Chemistry and Biology, Faculty of Science, Ryerson University, 350 Victoria Street, Toronto ON M5B 2 K3, Canada.
- Institute for Biomedical Engineering, Science, and Technology (iBEST), Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, 209 Victoria Street, Toronto ON M5B 1 T8, Canada
| | - Amanda Bishop
- Department of Chemistry, Faculty of Science, University of Calgary, 2500 University Dr NW, Calgary, AB T2N 1N4, Canada
| | - Kathleen P Wilkie
- Department of Mathematics, Faculty of Science, Ryerson University, 350 Victoria Street, Toronto ON M5B 2 K3, Canada
| | - David T Cramb
- Department of Chemistry and Biology, Faculty of Science, Ryerson University, 350 Victoria Street, Toronto ON M5B 2 K3, Canada.
- Institute for Biomedical Engineering, Science, and Technology (iBEST), Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, 209 Victoria Street, Toronto ON M5B 1 T8, Canada
- Department of Chemistry, Faculty of Science, University of Calgary, 2500 University Dr NW, Calgary, AB T2N 1N4, Canada
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21
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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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22
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Berganza E, Hirtz M. Direct-Write Patterning of Biomimetic Lipid Membranes In Situ with FluidFM. ACS APPLIED MATERIALS & INTERFACES 2021; 13:50774-50784. [PMID: 34677057 DOI: 10.1021/acsami.1c15166] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The creation of biologically inspired artificial membranes on substrates with custom size and in close proximity to each other not only provides a platform to study biological processes in a simplified manner, but they also constitute building blocks for chemical or biological sensors integrated in microfluidic devices. Scanning probe lithography tools such as dip-pen nanolithography (DPN) have opened a new paradigm in this regard, although they possess some inherent drawbacks like the need to operate in air environment or the limited choice of lipids that can be patterned. In this work, we propose the use of the fluid force microscopy (FluidFM) technology to fabricate biomimetic membranes without losing the multiplexing capability of DPN but gaining flexibility in lipid inks and patterning environment. We shed light on the driving mechanisms of the FluidFM-mediated lithography processes in air and liquid. The obtained results should prompt the creation of more realistic biomimetic membranes with arbitrary complex phospholipid mixtures, cholesterol, and potential functional membrane proteins directly patterned in physiological environment.
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Affiliation(s)
- Eider Berganza
- Institute of Nanotechnology (INT) & Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Michael Hirtz
- Institute of Nanotechnology (INT) & Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
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23
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Intertwined and Finely Balanced: Endoplasmic Reticulum Morphology, Dynamics, Function, and Diseases. Cells 2021; 10:cells10092341. [PMID: 34571990 PMCID: PMC8472773 DOI: 10.3390/cells10092341] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/02/2021] [Accepted: 09/04/2021] [Indexed: 02/07/2023] Open
Abstract
The endoplasmic reticulum (ER) is an organelle that is responsible for many essential subcellular processes. Interconnected narrow tubules at the periphery and thicker sheet-like regions in the perinuclear region are linked to the nuclear envelope. It is becoming apparent that the complex morphology and dynamics of the ER are linked to its function. Mutations in the proteins involved in regulating ER structure and movement are implicated in many diseases including neurodegenerative diseases such as Alzheimer’s, Parkinson’s, and amyotrophic lateral sclerosis (ALS). The ER is also hijacked by pathogens to promote their replication. Bacteria such as Legionella pneumophila and Chlamydia trachomatis, as well as the Zika virus, bind to ER morphology and dynamics-regulating proteins to exploit the functions of the ER to their advantage. This review covers our understanding of ER morphology, including the functional subdomains and membrane contact sites that the organelle forms. We also focus on ER dynamics and the current efforts to quantify ER motion and discuss the diseases related to ER morphology and dynamics.
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24
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Ortiz J, Oliva A, Teruel JA, Aranda FJ, Ortiz A. Effect of pH and temperature on the aggregation behaviour of dirhamnolipid biosurfactant. An experimental and molecular dynamics study. J Colloid Interface Sci 2021; 597:160-170. [PMID: 33872875 DOI: 10.1016/j.jcis.2021.03.177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 03/26/2021] [Accepted: 03/31/2021] [Indexed: 11/16/2022]
Abstract
HYPOTHESIS Pseudomonas aeruginosa dirhamnolipid (diRL) has been shown to form aggregates of different size and structure, under various conditions. Due to the presence of a carboxyl group in the molecule, it is expected that pH would strongly affect this aggregation behaviour. In addition, preliminary observations of temperature-induced changes in the states of aggregation of diRL supported the need of further investigation. EXPERIMENTS A systematic experimental study, using differential scanning calorimetry (DSC), small-angle Xray diffraction (SAXD), and Fourier-transform infrared spectroscopy (FTIR), has been carried out to characterize pH and temperature driven changes in the aggregation behavior of diRL biosurfactant. Molecular dynamics (MD) simulations, supported by the experimental results, allowed depicting molecular details on formation of diRL membranes and other aggregated structures under various physicochemical conditions. FINDINGS DiRL could adopt fairly organized multilayered structures (membranes) at low pH and temperature, which became highly disordered upon increasing either of these parameters. The effect of pH on the gauche/all-trans conformer ratio of the diRL acyl chains was not of significance, whereas temperature-induced effects were observed. For the first time it is described that diRL underwent an endothermic thermotropic transition with Tc = 34 °C as observed by DSC, at pH 4.5 (protonated diRL), but not at pH 7.4 (unprotonated diRL). FTIR confirmed these findings, showing a significant additional disordering of the all-trans acyl chains upon increasing temperature around that same value in the protonated form, an effect not observed for the dissociated form of the biosurfactant. In addition, at pH 7.4, changing temperature did not modify the hydration state of the polar moiety of diRL, whereas at pH 4.5 a significant decrease in the hydration state around 34 °C took place. SAXD data showed that protonated diRL formed multilayered structures at 20 °C, which converted into poorly correlated layers at 50 °C. MD simulations supported these findings, showing that the membrane-like structures formed by protonated diRL at 20 °C became unstable at higher temperatures, tending to form other structures, which could be micelles or other type of layered structures, whereas the negatively charged form of diRL organized in micelle-type aggregates in the whole range of temperature under study.
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Affiliation(s)
- Julia Ortiz
- Departamento de Bioquímica y Biología Molecular-A, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, E-30100 Murcia, Spain
| | - Alfonso Oliva
- Departamento de Bioquímica y Biología Molecular-A, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, E-30100 Murcia, Spain
| | - José A Teruel
- Departamento de Bioquímica y Biología Molecular-A, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, E-30100 Murcia, Spain
| | - Francisco J Aranda
- Departamento de Bioquímica y Biología Molecular-A, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, E-30100 Murcia, Spain
| | - Antonio Ortiz
- Departamento de Bioquímica y Biología Molecular-A, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, E-30100 Murcia, Spain.
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Simeral ML, Zhang A, Demers SME, Hughes HJ, Abdul-Moqueet M, Mayer KM, Hafner JH. Effects of Conformational Variation on Structural Insights from Solution-Phase Surface-Enhanced Raman Spectroscopy. J Phys Chem B 2021; 125:2031-2041. [PMID: 33617719 PMCID: PMC8046088 DOI: 10.1021/acs.jpcb.0c10576] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Surface-enhanced Raman scattering (SERS) spectra contain information on the chemical structure on nanoparticle surfaces through the position and alignment of molecules with the electromagnetic near field. Time-dependent density functional theory (TDDFT) can provide the Raman tensors needed for a detailed interpretation of SERS spectra. Here, the impact of molecular conformations on SERS spectra is considered. TDDFT calculations of the surfactant cetyltrimethylammonium bromide with five conformers produced more accurate unenhanced Raman spectra than a simple all-trans structure. The calculations and measurements also demonstrated a loss of structural information in the CH2/CH3 scissor vibration band at 1450 cm-1 in the SERS spectra. To study lipid bilayers, TDDFT calculations on conformers of methyl phosphorylcholine and cis-5-decene served as models for the symmetric choline stretch in the lipid headgroup and the C═C stretch in the acyl chains of 1,2-oleoyl-glycero-3-phosphocholine. Conformer considerations enabled a measurement of the distribution of double-bond orientations with an order parameter of SC═C = 0.53.
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Affiliation(s)
| | - Aobo Zhang
- Department of Physics & Astronomy, Rice University, Houston, TX
| | | | | | | | - Kathryn M. Mayer
- Department of Physics & Astronomy, University of Texas at San Antonio, San Antonio, TX
| | - Jason H. Hafner
- Department of Physics & Astronomy, Rice University, Houston, TX
- Department of Chemistry, Rice University, Houston, TX
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Visualization of the mechanosensitive ion channel MscS under membrane tension. Nature 2021; 590:509-514. [PMID: 33568813 DOI: 10.1038/s41586-021-03196-w] [Citation(s) in RCA: 67] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 01/06/2021] [Indexed: 12/20/2022]
Abstract
Mechanosensitive channels sense mechanical forces in cell membranes and underlie many biological sensing processes1-3. However, how exactly they sense mechanical force remains under investigation4. The bacterial mechanosensitive channel of small conductance, MscS, is one of the most extensively studied mechanosensitive channels4-8, but how it is regulated by membrane tension remains unclear, even though the structures are known for its open and closed states9-11. Here we used cryo-electron microscopy to determine the structure of MscS in different membrane environments, including one that mimics a membrane under tension. We present the structures of MscS in the subconducting and desensitized states, and demonstrate that the conformation of MscS in a lipid bilayer in the open state is dynamic. Several associated lipids have distinct roles in MscS mechanosensation. Pore lipids are necessary to prevent ion conduction in the closed state. Gatekeeper lipids stabilize the closed conformation and dissociate with membrane tension, allowing the channel to open. Pocket lipids in a solvent-exposed pocket between subunits are pulled out under sustained tension, allowing the channel to transition to the subconducting state and then to the desensitized state. Our results provide a mechanistic underpinning and expand on the 'force-from-lipids' model for MscS mechanosensation4,11.
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Abstract
Molecular dynamics (MD) simulations have become increasingly useful in the modern drug development process. In this review, we give a broad overview of the current application possibilities of MD in drug discovery and pharmaceutical development. Starting from the target validation step of the drug development process, we give several examples of how MD studies can give important insights into the dynamics and function of identified drug targets such as sirtuins, RAS proteins, or intrinsically disordered proteins. The role of MD in antibody design is also reviewed. In the lead discovery and lead optimization phases, MD facilitates the evaluation of the binding energetics and kinetics of the ligand-receptor interactions, therefore guiding the choice of the best candidate molecules for further development. The importance of considering the biological lipid bilayer environment in the MD simulations of membrane proteins is also discussed, using G-protein coupled receptors and ion channels as well as the drug-metabolizing cytochrome P450 enzymes as relevant examples. Lastly, we discuss the emerging role of MD simulations in facilitating the pharmaceutical formulation development of drugs and candidate drugs. Specifically, we look at how MD can be used in studying the crystalline and amorphous solids, the stability of amorphous drug or drug-polymer formulations, and drug solubility. Moreover, since nanoparticle drug formulations are of great interest in the field of drug delivery research, different applications of nano-particle simulations are also briefly summarized using multiple recent studies as examples. In the future, the role of MD simulations in facilitating the drug development process is likely to grow substantially with the increasing computer power and advancements in the development of force fields and enhanced MD methodologies.
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Chorlay A, Thiam AR. Neutral lipids regulate amphipathic helix affinity for model lipid droplets. J Cell Biol 2020; 219:133864. [PMID: 32328636 PMCID: PMC7147095 DOI: 10.1083/jcb.201907099] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 12/14/2019] [Accepted: 01/27/2020] [Indexed: 02/07/2023] Open
Abstract
Cellular lipid droplets (LDs) have a neutral lipid core shielded from the aqueous environment by a phospholipid monolayer containing proteins. These proteins define the biological functions of LDs, and most of them bear amphipathic helices (AH), which can selectively target to LDs, or to LD subsets. How such binding preference happens remains poorly understood. Here, we found that artificial LDs made of different neutral lipids but presenting equal phospholipid packing densities differentially recruit AHs. Varying the phospholipid density shifts the binding levels, but the differential recruitment is unchanged. We found that the binding level of AHs is defined by their interaction preference with neutral lipids and ability to decrease surface tension. The phospholipid packing level regulates mainly the amount of neutral lipid accessible. Therefore, it is the hydrophobic nature of the phospholipid packing voids that controls the binding level of AHs. Our data bring us a major step closer to understanding the binding selectivity of AHs to lipid membranes.
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Affiliation(s)
- Aymeric Chorlay
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, Centre National de la Recherche Scientifique, Sorbonne Université, Université de Paris, Paris, France
| | - Abdou Rachid Thiam
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, Centre National de la Recherche Scientifique, Sorbonne Université, Université de Paris, Paris, France
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29
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Drabik D, Gavutis M, Valiokas RN, Ulčinas AR. Determination of the Mechanical Properties of Model Lipid Bilayers Using Atomic Force Microscopy Indentation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:13251-13262. [PMID: 33125251 DOI: 10.1021/acs.langmuir.0c02181] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
By conducting a systematic study of model lipid membranes using the atomic force microscopy (AFM) indentation, we demonstrate the importance of an experimental protocol on the determination of their mechanical parameters. We refine the experimental approach by analyzing the influence of the contact mechanics models used to process the data, substrate preparation, and indenter geometry. We show that both bending rigidity and area compressibility can be determined from a single AFM indentation measurement.
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Affiliation(s)
- Dominik Drabik
- Laboratory of Cytobiochemistry, Faculty of Biotechnology, University of Wrocław, F. Joliot-Curie 14a, Wrocław 50-383, Poland
| | - Martynas Gavutis
- Department of Nanoengineering, Center for Physical Sciences and Technology, Savanoriu̧ 231, Vilnius LT-02300, Lithuania
| | - Ramu Nas Valiokas
- Department of Nanoengineering, Center for Physical Sciences and Technology, Savanoriu̧ 231, Vilnius LT-02300, Lithuania
| | - Artu Ras Ulčinas
- Department of Nanoengineering, Center for Physical Sciences and Technology, Savanoriu̧ 231, Vilnius LT-02300, Lithuania
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30
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George SS, Steele CR, Ricci AJ. Rat Auditory Inner Hair Cell Mechanotransduction and Stereociliary Membrane Diffusivity Are Similarly Modulated by Calcium. iScience 2020; 23:101773. [PMID: 33294782 PMCID: PMC7689183 DOI: 10.1016/j.isci.2020.101773] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 10/03/2020] [Accepted: 11/03/2020] [Indexed: 11/16/2022] Open
Abstract
The lipid bilayer plays a pivotal role in force transmission to many mechanically-gated channels. We developed the technology to monitor membrane diffusivity in order to test the hypothesis positing that Ca2+ regulates open probability (P o) of cochlear hair cell mechanotransduction (MET) channels via the plasma membrane. The stereociliary membrane was more diffusive (9x) than the basolateral membrane. Elevating intracellular Ca2+ buffering or lowering extracellular Ca2+ reduced stereociliary diffusivity and increased MET P o. In contrast, prolonged depolarization increased stereociliary diffusivity and reduced MET P o. No comparable effects were noted for soma measurements. Although MET channels are located in the shorter stereocilia rows, both rows had similar baseline diffusivity and showed similar responses to Ca2+ manipulations and MET channel blocks, suggesting that diffusivity is independent of MET. Together, these data suggest that the stereociliary membrane is a component of a calcium-modulated viscoelastic-like element regulating hair cell mechanotransduction.
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Affiliation(s)
- Shefin S George
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, Stanford University, 240 Pasteur Drive, Stanford, CA 94305, USA
| | - Charles R Steele
- Department of Mechanical Engineering, Building 520, 440 Escondido Mall, Stanford University, CA 94305, USA
| | - Anthony J Ricci
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, Stanford University, 240 Pasteur Drive, Stanford, CA 94305, USA.,Department of Molecular and Cellular Physiology, School of Medicine, Stanford University, 291 Campus Drive, Stanford, CA 94305, USA
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31
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Schäfer AB, Wenzel M. A How-To Guide for Mode of Action Analysis of Antimicrobial Peptides. Front Cell Infect Microbiol 2020; 10:540898. [PMID: 33194788 PMCID: PMC7604286 DOI: 10.3389/fcimb.2020.540898] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 09/18/2020] [Indexed: 12/11/2022] Open
Abstract
Antimicrobial peptides (AMPs) are a promising alternative to classical antibiotics in the fight against multi-resistant bacteria. They are produced by organisms from all domains of life and constitute a nearly universal defense mechanism against infectious agents. No drug can be approved without information about its mechanism of action. In order to use them in a clinical setting, it is pivotal to understand how AMPs work. While many pore-forming AMPs are well-characterized in model membrane systems, non-pore-forming peptides are often poorly understood. Moreover, there is evidence that pore formation may not happen or not play a role in vivo. It is therefore imperative to study how AMPs interact with their targets in vivo and consequently kill microorganisms. This has been difficult in the past, since established methods did not provide much mechanistic detail. Especially, methods to study membrane-active compounds have been scarce. Recent advances, in particular in microscopy technology and cell biological labeling techniques, now allow studying mechanisms of AMPs in unprecedented detail. This review gives an overview of available in vivo methods to investigate the antibacterial mechanisms of AMPs. In addition to classical mode of action classification assays, we discuss global profiling techniques, such as genomic and proteomic approaches, as well as bacterial cytological profiling and other cell biological assays. We cover approaches to determine the effects of AMPs on cell morphology, outer membrane, cell wall, and inner membrane properties, cellular macromolecules, and protein targets. We particularly expand on methods to examine cytoplasmic membrane parameters, such as composition, thickness, organization, fluidity, potential, and the functionality of membrane-associated processes. This review aims to provide a guide for researchers, who seek a broad overview of the available methodology to study the mechanisms of AMPs in living bacteria.
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Affiliation(s)
| | - Michaela Wenzel
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
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32
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Aceves-Luna H, Glossman-Mitnik D, Flores-Holguín N. Oxidation degree of a cell membrane model and its response to structural changes, a coarse-grained molecular dynamics approach. J Biomol Struct Dyn 2020; 40:1930-1941. [PMID: 33063644 DOI: 10.1080/07391102.2020.1833759] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Oxidative stress plays an essential role in the regulation of vital processes in living organisms. Reactive oxygen species can react chemically with the constituents of the cells leading to irreversible damage. The first structure of the cell in contact with the environment that surrounds it is the membrane, which protects it and allows the exchange of substances. Some signals manifest when the components of a bilayer are undergoing oxidation, like an increase in the lipid area, decrease in the thickness of the bilayer, and exchange of the oxidized groups toward the bilayer surface. In this investigation, a molecular dynamics simulation was done on a set of Dioleoylphosphatidylcholine membranes with different percentage of oxidized lipids, in order to observe the effect of the oxidation degree on the membrane structure. It was found that, as higher the concentration of oxidized lipids is, the larger the damage of the membrane. This is reflected in the increase in the lipid area and the decrease in the thickness and membrane packing. Also, it was observed that hydrophobicity inside the membrane decreases as the oxidation percentage increases.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Hugo Aceves-Luna
- Laboratorio Virtual NANOCOSMOS, Departamento de Medio Ambiente y Energía, Centro de Investigación en Materiales Avanzados, Complejo Industrial Chihuahua, Chihuahua, Chih, Mexico
| | - Daniel Glossman-Mitnik
- Laboratorio Virtual NANOCOSMOS, Departamento de Medio Ambiente y Energía, Centro de Investigación en Materiales Avanzados, Complejo Industrial Chihuahua, Chihuahua, Chih, Mexico
| | - Norma Flores-Holguín
- Laboratorio Virtual NANOCOSMOS, Departamento de Medio Ambiente y Energía, Centro de Investigación en Materiales Avanzados, Complejo Industrial Chihuahua, Chihuahua, Chih, Mexico
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33
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Cazzola H, Lemaire L, Acket S, Prost E, Duma L, Erhardt M, Čechová P, Trouillas P, Mohareb F, Rossi C, Rossez Y. The Impact of Plasma Membrane Lipid Composition on Flagellum-Mediated Adhesion of Enterohemorrhagic Escherichia coli. mSphere 2020; 5:e00702-20. [PMID: 32938696 PMCID: PMC7494831 DOI: 10.1128/msphere.00702-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 08/27/2020] [Indexed: 01/07/2023] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a major cause of foodborne gastrointestinal illness. The adhesion of EHEC to host tissues is the first step enabling bacterial colonization. Adhesins such as fimbriae and flagella mediate this process. Here, we studied the interaction of the bacterial flagellum with the host cell's plasma membrane using giant unilamellar vesicles (GUVs) as a biologically relevant model. Cultured cell lines contain many different molecular components, including proteins and glycoproteins. In contrast, with GUVs, we can characterize the bacterial mode of interaction solely with a defined lipid part of the cell membrane. Bacterial adhesion on GUVs was dependent on the presence of the flagellar filament and its motility. By testing different phospholipid head groups, the nature of the fatty acid chains, or the liposome curvature, we found that lipid packing is a key parameter to enable bacterial adhesion. Using HT-29 cells grown in the presence of polyunsaturated fatty acid (α-linolenic acid) or saturated fatty acid (palmitic acid), we found that α-linolenic acid reduced adhesion of wild-type EHEC but not of a nonflagellated mutant. Finally, our results reveal that the presence of flagella is advantageous for the bacteria to bind to lipid rafts. We speculate that polyunsaturated fatty acids prevent flagellar adhesion on membrane bilayers and play a clear role for optimal host colonization. Flagellum-mediated adhesion to plasma membranes has broad implications for host-pathogen interactions.IMPORTANCE Bacterial adhesion is a crucial step to allow bacteria to colonize their hosts, invade tissues, and form biofilm. Enterohemorrhagic Escherichia coli O157:H7 is a human pathogen and the causative agent of diarrhea and hemorrhagic colitis. Here, we use biomimetic membrane models and cell lines to decipher the impact of lipid content of the plasma membrane on enterohemorrhagic E. coli flagellum-mediated adhesion. Our findings provide evidence that polyunsaturated fatty acid (α-linolenic acid) inhibits E. coli flagellar adhesion to the plasma membrane in a mechanism separate from its antimicrobial and anti-inflammatory functions. In addition, we confirm that cholesterol-enriched lipid microdomains, often called lipid rafts, are important in bacterial adhesion. These findings demonstrate that plasma membrane adhesion via bacterial flagella play a significant role for an important human pathogen. This mechanism represents a promising target for the development of novel antiadhesion therapies.
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Affiliation(s)
- Hélène Cazzola
- Université de Technologie de Compiègne, UPJV, UMR CNRS 7025, Enzyme and Cell Engineering, Centre de recherche Royallieu, Compiègne, France
| | - Laurine Lemaire
- Université de Technologie de Compiègne, UPJV, UMR CNRS 7025, Enzyme and Cell Engineering, Centre de recherche Royallieu, Compiègne, France
| | - Sébastien Acket
- Université de Technologie de Compiègne, UPJV, UMR CNRS 7025, Enzyme and Cell Engineering, Centre de recherche Royallieu, Compiègne, France
| | - Elise Prost
- Université de Technologie de Compiègne, UPJV, UMR CNRS 7025, Enzyme and Cell Engineering, Centre de recherche Royallieu, Compiègne, France
| | - Luminita Duma
- Université de Technologie de Compiègne, UPJV, UMR CNRS 7025, Enzyme and Cell Engineering, Centre de recherche Royallieu, Compiègne, France
| | - Marc Erhardt
- Institute for Biology-Bacterial Physiology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Petra Čechová
- RCPTM, Palacký University Olomouc, Olomouc, Czech Republic
| | - Patrick Trouillas
- RCPTM, Palacký University Olomouc, Olomouc, Czech Republic
- INSERM U1248-IPPRITT, University of Limoges, Limoges, France
| | - Fady Mohareb
- The Bioinformatics Group, School of Water, Energy and Environment, Cranfield University, Cranfield, United Kingdom
| | - Claire Rossi
- Université de Technologie de Compiègne, UPJV, UMR CNRS 7025, Enzyme and Cell Engineering, Centre de recherche Royallieu, Compiègne, France
| | - Yannick Rossez
- Université de Technologie de Compiègne, UPJV, UMR CNRS 7025, Enzyme and Cell Engineering, Centre de recherche Royallieu, Compiègne, France
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Oda A, Watanabe C, Aoki N, Yanagisawa M. Liposomal adhesion via electrostatic interactions and osmotic deflation increase membrane tension and lipid diffusion coefficient. SOFT MATTER 2020; 16:4549-4554. [PMID: 32364199 DOI: 10.1039/d0sm00416b] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Membrane adhesion is a ubiquitous phenomenon in cells and is related to various biological events such as migration, morphogenesis, and differentiation. To understand the physicochemical aspects of membrane adhesion, liposome-liposome adhesion and liposome-substrate adhesion have been studied. Although membrane adhesion has been shown to increase membrane tension and inhibit lipid diffusion, the relationship between these changes and the degree of membrane adhesion have not been quantified. Here, we analyzed the dependence of membrane tension and lipid diffusion on the degree of membrane adhesion, i.e., area fraction of the adherent region. For this purpose, we developed a simple method to prepare adhered liposomes by simple electrostatic interactions between the membranes and by osmotic deflation. We found that the membrane tension of the adhered liposomes increases slightly with an increase in the area fraction of the adherent region. In addition, the lipid diffusion coefficient of the adhered liposomes is larger than that of isolated liposomes, which is consistent with the theoretical prediction. The analysis provides a framework to understand the correlation between cell adhesion and bio-membrane properties such as membrane tension and molecular diffusion.
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Affiliation(s)
- Atsushi Oda
- Department of Applied Physics, Tokyo University of Agriculture and Technology, Naka-cho 2-24-16, Koganei, Tokyo 184-8588, Japan
| | - Chiho Watanabe
- Komaba Institute for Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro, Tokyo 153-8902, Japan.
| | - Natsumi Aoki
- Department of Applied Physics, Tokyo University of Agriculture and Technology, Naka-cho 2-24-16, Koganei, Tokyo 184-8588, Japan
| | - Miho Yanagisawa
- Komaba Institute for Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro, Tokyo 153-8902, Japan. and Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro, Tokyo 153-8902, Japan
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35
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Chi Q, Yang Z, Xu K, Wang C, Liang H. DNA Nanostructure as an Efficient Drug Delivery Platform for Immunotherapy. Front Pharmacol 2020; 10:1585. [PMID: 32063844 PMCID: PMC6997790 DOI: 10.3389/fphar.2019.01585] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 12/06/2019] [Indexed: 12/19/2022] Open
Abstract
Immunotherapy has received increasing attention due to its low potential side effects and high specificity. For instance, cancer immunotherapy has achieved great success. CpG is a well-known and commonly used immunotherapeutic and vaccine adjuvant, but it has the disadvantage of being unstable and low in efficacy and needs to be transported through an effective nanocarrier. With perfect structural programmability, permeability, and biocompatibility, DNA nanostructures are one of the most promising candidates to deliver immune components to realize immunotherapy. However, the instability and low capability of the payload of ordinary DNA assemblies limit the relevant applications. Consequently, DNA nanostructure with a firm structure, high drug payloads is highly desirable. In the paper, the latest progress of biostable, high-payload DNA nanoassemblies of various structures, including cage-like DNA nanostructure, DNA particles, DNA polypods, and DNA hydrogel, are reviewed. Cage-like DNA structures hold drug molecules firmly inside the structure and leave a large space within the cavity. These DNA nanostructures use their unique structure to carry abundant CpG, and their biocompatibility and size advantages to enter immune cells to achieve immunotherapy for various diseases. Part of the DNA nanostructures can also achieve more effective treatment in conjunction with other functional components such as aPD1, RNA, TLR ligands.
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Affiliation(s)
- Qingjia Chi
- State Key Laboratory of Trauma, Burns and Combined Injury, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, China
- Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics, Department of Mechanics and Engineering Structure, Wuhan University of Technology, Wuhan, China
| | - Zichang Yang
- Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics, Department of Mechanics and Engineering Structure, Wuhan University of Technology, Wuhan, China
| | - Kang Xu
- Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chunli Wang
- “111” Project Laboratory of Biomechanics and Tissue Repair, Bioengineering College, Chongqing University, Chongqing, China
| | - Huaping Liang
- State Key Laboratory of Trauma, Burns and Combined Injury, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, China
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Maeda E, Kuroyanagi K, Ando Y, Matsumoto T. Effects of Substrate Stiffness on Morphology and MMP-1 Gene Expression in Tenocytes Stimulated With Interleukin-1β. J Orthop Res 2020; 38:150-159. [PMID: 31254408 DOI: 10.1002/jor.24403] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 06/18/2019] [Indexed: 02/04/2023]
Abstract
Tendon cells, tenocytes, are constantly subjected to mechanical stress in vivo, which maintains a level of cellular tension. When a tendon is subjected to overloading, local rupture of collagen fibers are induced, which deprives tenocytes of mechanical stress, lowers their cellular tension level and upregulates their catabolism. In addition, leukocytes are attracted to the rupture sites and produce interleukin-1β (IL-1β), and this exogenous IL-1β also stimulates tenocyte catabolism. We tested a hypothesis that catabolic tenocytes with low cellular tension at the rupture sites excessively respond to the exogenous IL-1β and further upregulate matrix metalloproteinase 1 (MMP-1) gene expression. Tenocytes from rabbit Achilles tendon were cultured on the following substrates: glass or polydimethylsiloxane micropillar substrates with a height of 2, 4, or 8 µm. Following a 3-day IL-1β stimulation at a concentration of 0, 1, 10, or 100 pM, the effects of IL-1β stimulation on cell morphology and MMP-1 gene expression was analysed with fluorescent microscopy and fluorescence in situ hybridization, respectively. In addition, the effects of IL-1β stimulation on cell membrane fluidity were examined. It was demonstrated that the cells on 8-µm-height micropillars exhibited a greater response than those on rigid substrates with flat (glass) and topologically the same surface (2-µm-height micropillars) to IL-1β when supplied at the same concentration. Besides this, membrane fluidity was lower in the cells on micropillars. Therefore, it appears that cellular attachment to softer substrates lowers the cellular actin cortex tension, reducing the membrane fluidity and possibly elevating the sensitivity of IL-1 receptors to ligand binding. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:150-159, 2020.
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Affiliation(s)
- Eijiro Maeda
- Biomechanics Laboratory, Department of Mechanical Systems Engineering, Graduate School of Engineering, Nagoya University, Nagoya, Japan
| | - Kaname Kuroyanagi
- Biomechanics Laboratory, Department of Mechanical Systems Engineering, Graduate School of Engineering, Nagoya University, Nagoya, Japan
| | - Yoriko Ando
- Biomechanics Laboratory, Department of Mechanical Systems Engineering, Graduate School of Engineering, Nagoya University, Nagoya, Japan
| | - Takeo Matsumoto
- Biomechanics Laboratory, Department of Mechanical Systems Engineering, Graduate School of Engineering, Nagoya University, Nagoya, Japan
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Ngo DTN, Nguyen TQ, Huynh HK, Nguyen TT. Thermodynamics of selective serotonin reuptake inhibitors partitioning into 1,2-dioleoyl- sn-glycero-3-phosphocholine bilayers. RSC Adv 2020; 10:39338-39347. [PMID: 35518408 PMCID: PMC9057331 DOI: 10.1039/d0ra07367a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 10/14/2020] [Indexed: 11/28/2022] Open
Abstract
Knowledge of thermodynamics of lipid membrane partitioning of amphiphilic drugs as well as their binding site within the membrane are of great relevance not only for understanding the drugs' pharmacology but also for the development and optimization of more potent drugs. In this study, the interaction between two representatives of selective serotonin reuptake inhibitors, including paroxetine and sertraline, and large unilamellar vesicles (LUVs) composed of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) was investigated by second derivative spectrophotometry and Fourier transform infrared spectroscopy (FTIR) to determine the driving force of the drug partitioning across lipid membranes. It was found that temperature increase from 25 to 42 °C greatly enhanced the partitioning of paroxetine and sertraline into DOPC LUVs, and sertraline intercalated into the lipid vesicles to a greater extent than paroxetine in the temperature range examined. The partitioning of both drugs into DOPC LUVs was a spontaneous, endothermic and entropy-driven process. FTIR measurements suggested that sertraline could penetrate deeply into the acyl tails of DOPC LUVs as shown by the considerable shifts in the lipid's CH2 and C
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O stretching modes induced by the drug. Paroxetine, however, could reside closer to the head groups of the lipid since its presence caused a larger shift in the PO2− bands of DOPC LUVs. The findings reported here provide valuable insights into the influence of small molecules' chemical structure on their molecular interaction with the lipid bilayer namely their possible binding sites within the lipid bilayer and their thermodynamics profiles of partitioning, which could benefit rational drug design and drug delivery systems. Paroxetine and sertraline have the same thermodynamics profile of phospholipid bilayer partitioning but different location within the lipid bilayer.![]()
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Affiliation(s)
- Dat T. N. Ngo
- Department of Biotechnology
- International University
- Ho Chi Minh City
- Vietnam
- Vietnam National University
| | - Trinh Q. Nguyen
- Department of Biotechnology
- International University
- Ho Chi Minh City
- Vietnam
- Vietnam National University
| | - Hieu K. Huynh
- University of Medicine and Pharmacy at Ho Chi Minh City
- Ho Chi Minh City
- Vietnam
| | - Trang T. Nguyen
- Department of Chemical Engineering
- International University
- Ho Chi Minh City
- Vietnam
- Vietnam National University
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38
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Peñaflor Galindo TG, Tagaya M. Interfacial Effect of Hydration Structures of Hydroxyapatite Nanoparticle Films on Protein Adsorption and Cell Adhesion States. ACS APPLIED BIO MATERIALS 2019; 2:5559-5567. [PMID: 35021551 DOI: 10.1021/acsabm.9b00629] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The synthesized elliptical hydroxyapatite (E-HAp) and needle-like HAp (N-HAp) nanoparticles (NPs) were electrophoretically deposited on a gold (Au) substrate. A comparative study of the hydration layers on E-HAp, N-HAp, and Au films was achieved to investigate the interfacial effect of the hydration layers on the conformation of the adsorbed fibrinogen (Fgn) and fibroblast adhesion properties. As a result, the ratios of three types of hydration layer states (free water, intermediate water, nonfreezing water) analyzed by a Fourier transform infrared (FT-IR) spectral deconvolution of the O-H stretching absorption band were investigated. The ratio of the bonding water state (i.e., intermediate and nonfreezing water molecules) is almost the same between two HAp films, and the E-HAp film with an elliptical shape and smaller particle size exhibited the smallest ratio of nonfreezing water, which can suppress the denaturation of the adsorbed protein. Subsequently, FT-IR spectral deconvolution results of the amide I band of the adsorbed Fgn on the E-HAp film indicated the higher proportion of α-helix and β-sheet structures as compared with those on the N-HAp and Au films, suggesting that the smaller proportion of nonfreezing waters would play a significant role in the stereoscopic Fgn conformation. In the culture of fibroblasts, FT-IR spectra of the adhered cells on the E-HAp, N-HAp, and Au films exhibited different absorbance intensities of the amide A, I, II, and III bands, suggesting a different amount of collagen-producing states by the cells, which were also supported by immunostaining results of the collagen type I. Therefore, the different hydration structures on the films clearly influenced the conformation of the adsorbed protein, and the preferential conformation was found at the interfaces between the fibroblasts and the underground E-HAp films.
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Affiliation(s)
- Tania Guadalupe Peñaflor Galindo
- Department of Materials Science and Technology, Nagaoka University of Technology, Kamitomioka 1603-1, Nagaoka, Niigata 940-2188, Japan
| | - Motohiro Tagaya
- Department of Materials Science and Technology, Nagaoka University of Technology, Kamitomioka 1603-1, Nagaoka, Niigata 940-2188, Japan
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39
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Aloi E, Guzzi R, Bartucci R. Unsaturated lipid bilayers at cryogenic temperature: librational dynamics of chain-labeled lipids from pulsed and CW-EPR. Phys Chem Chem Phys 2019; 21:18699-18705. [PMID: 31423504 DOI: 10.1039/c9cp03318a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Fully hydrated bilayers of monounsaturated palmitoyloleoylphosphatidylcholine (POPC) and diunsaturated dioleoylphosphatidylcholine (DOPC) lipids have low main phase transition temperatures (271 K for POPC and 253 K for DOPC). Two-pulse echo detected spectra, combined with continuous wave electron paramagnetic resonance spectroscopy, are employed to study the low-temperature lamellar phases of the POPC and DOPC unsaturated bilayers that are usually studied in the fluid state. Phosphatidylcholine spin-labeled at C-5 and C-16 carbon atom positions along the acyl chain were used and the temperature varied over the range 77-270 K. Segmental chain librational oscillations of small amplitude and with correlation time in the subnanosecond to nanosecond range are found in both membranes. The mean-square angular amplitude, α2, of librations increases with temperature, is larger close to the bilayer midplane than close to the first acyl chain segments, and is larger in diunsaturated than in monounsaturated bilayers. In the inner hydrocarbon region of both lipid matrices, α2 increases first slowly and linearly with temperature and then more rapidly, and a dynamical transition is detected in the range 190-210 K. Compared to dipalmitoylphosphatidylcholine bilayers of fully saturated symmetric chain lipids, the presence of double bonds in the acyl chain enhances the intensity of librational motion which is characterized by larger angular variations at the terminal methyl ends. These findings highlight biophysical properties of unsaturated bilayers in the frozen state, including a detailed characterization of segmental chain dynamics and the evidence of a dynamical transition that appears to be a generic feature in hydrated macromolecular systems. These results can also be relevant in regulating membrane physical properties and function at higher physiological temperatures.
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Affiliation(s)
- Erika Aloi
- Department of Physics, Molecular Biophysics Laboratory, University of Calabria, 87036 Rende, Italy
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40
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Le Roux AL, Quiroga X, Walani N, Arroyo M, Roca-Cusachs P. The plasma membrane as a mechanochemical transducer. Philos Trans R Soc Lond B Biol Sci 2019; 374:20180221. [PMID: 31431176 PMCID: PMC6627014 DOI: 10.1098/rstb.2018.0221] [Citation(s) in RCA: 111] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/22/2019] [Indexed: 12/20/2022] Open
Abstract
Cells are constantly submitted to external mechanical stresses, which they must withstand and respond to. By forming a physical boundary between cells and their environment that is also a biochemical platform, the plasma membrane (PM) is a key interface mediating both cellular response to mechanical stimuli, and subsequent biochemical responses. Here, we review the role of the PM as a mechanosensing structure. We first analyse how the PM responds to mechanical stresses, and then discuss how this mechanical response triggers downstream biochemical responses. The molecular players involved in PM mechanochemical transduction include sensors of membrane unfolding, membrane tension, membrane curvature or membrane domain rearrangement. These sensors trigger signalling cascades fundamental both in healthy scenarios and in diseases such as cancer, which cells harness to maintain integrity, keep or restore homeostasis and adapt to their external environment. This article is part of a discussion meeting issue 'Forces in cancer: interdisciplinary approaches in tumour mechanobiology'.
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Affiliation(s)
- Anabel-Lise Le Roux
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute for Science and Technology (BIST), Barcelona 08028, Spain
| | - Xarxa Quiroga
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute for Science and Technology (BIST), Barcelona 08028, Spain
| | - Nikhil Walani
- LaCàN, Universitat Politècnica de Catalunya-BarcelonaTech, Spain
| | - Marino Arroyo
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute for Science and Technology (BIST), Barcelona 08028, Spain
- LaCàN, Universitat Politècnica de Catalunya-BarcelonaTech, Spain
| | - Pere Roca-Cusachs
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute for Science and Technology (BIST), Barcelona 08028, Spain
- Department of Biomedical Sciences, Universitat de Barcelona, Barcelona 08036, Spain
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41
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Temperature Dependence of the Structure and Dynamics of a Dye-Labeled Lipid in a Planar Phospholipid Bilayer: A Computational Study. J Membr Biol 2019; 252:227-240. [PMID: 31332471 DOI: 10.1007/s00232-019-00081-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 07/11/2019] [Indexed: 10/26/2022]
Abstract
Fluorescent probes are widely employed to label lipids for the investigation of structural and dynamic properties of model and cell membranes through optical microscopy techniques. Although the effect of tagging a lipid with an organic dye is generally assumed to be negligible, optically modified lipids can nonetheless affect the local lipid structure and, in turn, the lipid lateral mobility. To better assess this potential issue, all-atom (MD) molecular dynamics simulations have been performed to study structural and dynamic effects in a model DOPC membrane in the presence of a standard Rhodamine B-labeled DOPE lipid (RHB) as a function of temperature, i.e., 293 K, 303 K, and 320 K. As the temperature is increased, we observe similar changes in the structural properties of both pure DOPC and RHB-DOPC lipid bilayers: an increase of the area per lipid, a reduction of the membrane thickness and a decrease of lipid order parameters. The partial density profile of the RHB headgroups and their orientation within the lipid bilayer confirm the amphiphilic nature of the RHB fluorescent moiety, which mainly partitions in the DOPC glycerol backbone region at each temperature. Moreover, at all temperatures, our results on lipid lateral diffusion support a non-neutral role of the dye with respect to the unlabeled lipid mobility, thus suggesting important implications for optical microscopy studies of lipid membranes.
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42
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Belessiotis-Richards A, Higgins SG, Butterworth B, Stevens MM, Alexander-Katz A. Single-Nanometer Changes in Nanopore Geometry Influence Curvature, Local Properties, and Protein Localization in Membrane Simulations. NANO LETTERS 2019; 19:4770-4778. [PMID: 31241342 DOI: 10.1021/acs.nanolett.9b01990] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Nanoporous surfaces are used in many applications in intracellular sensing and drug delivery. However, the effects of such nanostructures on cell membrane properties are still far from understood. Here, we use coarse-grained molecular dynamics simulations to show that nanoporous substrates can stimulate membrane-curvature effects and that this curvature-sensing effect is much more sensitive than previously thought. We define a series of design parameters for inducing a nanoscale membrane curvature and show that nanopore taper plays a key role in membrane deformation, elucidating a previously unexplored fabrication parameter applicable to many nanostructured biomaterials. We report significant changes in the membrane area per lipid and thickness at regions of curvature. Finally, we demonstrate that regions of the nanopore-induced membrane curvature act as local hotspots for an increased bioactivity. We show spontaneous binding and localization of the epsin N-terminal homology (ENTH) domain to the regions of curvature. Understanding this interplay between the membrane curvature and nanoporosity at the biointerface helps both explain recent biological results and suggests a pathway for developing the next generation of cell-active substrates.
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Affiliation(s)
- Alexis Belessiotis-Richards
- Department of Materials , Imperial College London , Exhibition Road , London SW7 2AZ , United Kingdom
- Department of Bioengineering , Imperial College London , Exhibition Road , London SW7 2AZ , United Kingdom
- Institute of Biomedical Engineering , Imperial College London , Exhibition Road , London SW7 2AZ , United Kingdom
| | - Stuart G Higgins
- Department of Materials , Imperial College London , Exhibition Road , London SW7 2AZ , United Kingdom
- Department of Bioengineering , Imperial College London , Exhibition Road , London SW7 2AZ , United Kingdom
- Institute of Biomedical Engineering , Imperial College London , Exhibition Road , London SW7 2AZ , United Kingdom
| | - Ben Butterworth
- Department of Materials , Imperial College London , Exhibition Road , London SW7 2AZ , United Kingdom
| | - Molly M Stevens
- Department of Materials , Imperial College London , Exhibition Road , London SW7 2AZ , United Kingdom
- Department of Bioengineering , Imperial College London , Exhibition Road , London SW7 2AZ , United Kingdom
- Institute of Biomedical Engineering , Imperial College London , Exhibition Road , London SW7 2AZ , United Kingdom
| | - Alfredo Alexander-Katz
- Department of Materials Science & Engineering , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States
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43
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Losasso V, Hsiao YW, Martelli F, Winn MD, Crain J. Modulation of Antimicrobial Peptide Potency in Stressed Lipid Bilayers. PHYSICAL REVIEW LETTERS 2019; 122:208103. [PMID: 31172786 DOI: 10.1103/physrevlett.122.208103] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Indexed: 06/09/2023]
Abstract
It is shown that the tendency of an archetypal antimicrobial peptide to insert into and perforate a simple lipid bilayer is strongly modulated by tensile stress in the membrane. The results, obtained through molecular dynamics simulations, have been demonstrated with several lipid compositions and appear to be general, although quantitative details differ. The findings imply that the potency of antimicrobial peptides may not be a purely intrinsic chemical property and, instead, depends on the mechanical state of the target membrane.
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Affiliation(s)
- Valeria Losasso
- Daresbury Laboratory, STFC, Daresbury, Warrington, England WA4 4AD, United Kingdom
| | - Ya-Wen Hsiao
- Daresbury Laboratory, STFC, Daresbury, Warrington, England WA4 4AD, United Kingdom
| | - Fausto Martelli
- IBM Research, Hartree Centre, Daresbury, England WA4 4AD, United Kingdom
| | - Martyn D Winn
- Daresbury Laboratory, STFC, Daresbury, Warrington, England WA4 4AD, United Kingdom
| | - Jason Crain
- IBM Research, Hartree Centre, Daresbury, England WA4 4AD, United Kingdom
- Dept. of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, England
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44
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Li S, Yan Z, Luo Z, Xu Y, Huang F, Hu G, Zhang X, Yue T. Directional and Rotational Motions of Nanoparticles on Plasma Membranes as Local Probes of Surface Tension Propagation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:5333-5341. [PMID: 30908057 DOI: 10.1021/acs.langmuir.9b00225] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Mechanical heterogeneity is ubiquitous in plasma membranes and of essential importance to cellular functioning. As a feedback of mechanical stimuli, local surface tension can be readily changed and immediately propagated through the membrane, influencing structures and dynamics of both inclusions and membrane-associated proteins. Using the nonequilibrium coarse-grained membrane simulation, here we investigate the inter-related processes of tension propagation, lipid diffusion, and transport of nanoparticles (NPs) adhering on the membrane of constant tension gradient, mimicking that of migrating cells or cells under prolonged stimulation. Our results demonstrate that the lipid bilayer membrane can by itself propagate surface tension in defined rates and pathways to reach a dynamic equilibrium state where surface tension is linearly distributed along the gradient maintained by the directional flow-like motion of lipids. Such lipid flow exerts shearing forces to transport adhesive NPs toward the region of a larger surface tension. Under certain conditions, the shearing force can generate nonzero torques driving the rotational motion of NPs, with the direction of the NP rotation determined by the NP-membrane interaction state as functions of both NP property and local membrane surface tension. Such features endow NPs with promising applications ranging from biosensing to targeted drug delivery.
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Affiliation(s)
| | | | | | | | | | - Guoqing Hu
- State Key Laboratory of Nonlinear Mechanics (LNM) , Institute of Mechanics, Chinese Academy of Science , Beijing 100190 , China
- School of Engineering Science , University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Xianren Zhang
- State Key Laboratory of Organic-Inorganic Composites , Beijing University of Chemical Technology , Beijing 100029 , China
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45
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Pinto OA, Disalvo EA. A new model for lipid monolayer and bilayers based on thermodynamics of irreversible processes. PLoS One 2019; 14:e0212269. [PMID: 30947264 PMCID: PMC6448890 DOI: 10.1371/journal.pone.0212269] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Accepted: 01/30/2019] [Indexed: 11/29/2022] Open
Abstract
Lipid monolayers are used as experimental model systems to study the physical chemical properties of biomembranes. With this purpose, surface pressure/area per molecule isotherms provide a way to obtain information on packing and compressibility properties of the lipids. These isotherms have been interpreted considering the monolayer as a two dimensional ideal or van der Waals gas without contact with the water phase. These modelistic approaches do not fit the experimental results. Based on Thermodynamics of Irreversible Processes (TIP), the expansion/compression process is interpreted in terms of coupled phenomena between area changes and water fluxes between a bidimensional solution of hydrated head groups in the monolayer and the bulk solution. The formalism obtained can reproduce satisfactorily the surface pressure/area per lipid isotherms of monolayer in different states and also can explain the area expansion and compression produced in particles enclosed by bilayers during osmotic fluxes. This novel approach gives relevance to the lipid-water interaction in restricted media near the membrane and provides a formalism to understand the thermodynamic and kinetic response of biointerphases to biological effectors.
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Affiliation(s)
- O. A. Pinto
- Instituto de Bionanotecnología del NOA (INBIONATEC), Universidad Nacional de Santiago de Estero (UNSE- CONICET), Villa el Zanjón, Santiago del Estero, Argentina
| | - E. A. Disalvo
- Laboratorio de Biointerfases y Sistemas Biomiméticos, Centro de Investigaciones en Biofisica Aplicada y Alimentos (CIBAAL) (UNSE-CONICET), Villa el Zanjón, Santiago del Estero, Argentina
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46
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Shahane G, Ding W, Palaiokostas M, Orsi M. Physical properties of model biological lipid bilayers: insights from all-atom molecular dynamics simulations. J Mol Model 2019; 25:76. [PMID: 30806797 DOI: 10.1007/s00894-019-3964-0] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 02/07/2019] [Indexed: 02/04/2023]
Abstract
The physical properties of lipid bilayers are sensitive to the specific type and composition of the lipids that make up the many different types of cell membranes. Studying model bilayers of representative heterogeneous compositions can provide key insights into membrane functionality. In this work, we use atomistic molecular dynamics simulations to characterize key properties in a number of bilayer membranes of varying composition. We first examine basic properties, such as lipid area, volume, and bilayer thickness, of simple, homogeneous bilayers comprising several lipid types, which are prevalent in biological membranes. Such lipids are then used in simulations of heterogeneous systems representative of bacterial, mammalian, and cancer membranes. Our analysis is especially focused on depth-dependent, transmembrane profiles; in particular, we calculate lateral pressure and dipole potential profiles, two fundamental properties which play key roles in a large number of biological functions.
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Affiliation(s)
- Ganesh Shahane
- Institute of Bioengineering, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Wei Ding
- School of Engineering & Materials Science, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Michail Palaiokostas
- School of Engineering & Materials Science, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Mario Orsi
- Department of Applied Sciences, University of the West of England, Coldharbour Lane, Bristol, BS16 1QY, UK.
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47
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Jan Akhunzada M, D'Autilia F, Chandramouli B, Bhattacharjee N, Catte A, Di Rienzo R, Cardarelli F, Brancato G. Interplay between lipid lateral diffusion, dye concentration and membrane permeability unveiled by a combined spectroscopic and computational study of a model lipid bilayer. Sci Rep 2019; 9:1508. [PMID: 30728410 PMCID: PMC6365552 DOI: 10.1038/s41598-018-37814-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 12/10/2018] [Indexed: 01/08/2023] Open
Abstract
Lipid lateral diffusion in membrane bilayers is a fundamental process exploited by cells to enable complex protein structural and dynamic reorganizations. For its importance, lipid mobility in both cellular and model bilayers has been extensively investigated in recent years, especially through the application of time-resolved, fluorescence-based, optical microscopy techniques. However, one caveat of fluorescence techniques is the need to use dye-labeled variants of the lipid of interest, thus potentially perturbing the structural and dynamic properties of the native species. Generally, the effect of the dye/tracer molecule is implicitly assumed to be negligible. Nevertheless, in view of the widespread use of optically modified lipids for studying lipid bilayer dynamics, it is highly desirable to well assess this point. Here, fluorescence correlation spectroscopy (FCS) and molecular dynamics (MD) simulations have been combined together to uncover subtle structural and dynamic effects in DOPC planar membranes enriched with a standard Rhodamine-labeled lipid. Our findings support a non-neutral role of the dye-labeled lipids in diffusion experiments, quantitatively estimating a decrease in lipid mobility of up to 20% with respect to the unlabeled species. Moreover, results highlight the existing interplay between dye concentration, lipid lateral diffusion and membrane permeability, thus suggesting possible implications for future optical microscopy studies of biophysical processes occurring at the membrane level.
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Affiliation(s)
- Muhammad Jan Akhunzada
- Scuola Normale Superiore, piazza dei Cavalieri 7, I-56126, Pisa, Italy.,Istituto Nazionale di Fisica Nucleare, Largo Pontecorvo 3, I-56100, Pisa, Italy
| | | | - Balasubramanian Chandramouli
- Scuola Normale Superiore, piazza dei Cavalieri 7, I-56126, Pisa, Italy.,Compunet, Istituto Italiano di Tecnologia (IIT), Via Morego 30, I-16163, Genova, Italy
| | - Nicholus Bhattacharjee
- Scuola Normale Superiore, piazza dei Cavalieri 7, I-56126, Pisa, Italy.,Istituto Nazionale di Fisica Nucleare, Largo Pontecorvo 3, I-56100, Pisa, Italy
| | - Andrea Catte
- Scuola Normale Superiore, piazza dei Cavalieri 7, I-56126, Pisa, Italy.,Istituto Nazionale di Fisica Nucleare, Largo Pontecorvo 3, I-56100, Pisa, Italy
| | - Roberto Di Rienzo
- Dipartimento di Ingegneria dell'Informazione, Università di Pisa, Via Girolamo Caruso 16, I-56122 Pisa, Italy
| | - Francesco Cardarelli
- NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, Piazza San Silvestro 12, 56127, Pisa, Italy
| | - Giuseppe Brancato
- Scuola Normale Superiore, piazza dei Cavalieri 7, I-56126, Pisa, Italy. .,Istituto Nazionale di Fisica Nucleare, Largo Pontecorvo 3, I-56100, Pisa, Italy.
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48
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Liu J, Chen C, Lu C, Li W. Different mechanisms on the stabilization of POPC membrane by trehalose upon varied mechanical stress. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2018.10.094] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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49
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Hörning M, Shibata T. Three-Dimensional Cell Geometry Controls Excitable Membrane Signaling in Dictyostelium Cells. Biophys J 2019; 116:372-382. [PMID: 30635124 PMCID: PMC6350023 DOI: 10.1016/j.bpj.2018.12.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 11/16/2018] [Accepted: 12/13/2018] [Indexed: 01/13/2023] Open
Abstract
Phosphatidylinositol (3-5)-trisphosphate (PtdInsP3) is known to propagate as waves on the plasma membrane and is related to the membrane-protrusive activities in Dictyostelium and mammalian cells. Although there have been a few attempts to study the three-dimensional (3D) dynamics of these processes, most studies have focused on the dynamics extracted from single focal planes. However, the relation between the dynamics and 3D cell shape remains elusive because of the lack of signaling information about the unobserved part of the membrane. Here, we show that PtdInsP3 wave dynamics are directly regulated by the 3D geometry (i.e., size and shape) of the plasma membrane. By introducing an analysis method that extracts the 3D spatiotemporal activities on the entire cell membrane, we show that PtdInsP3 waves self-regulate their dynamics within the confined membrane area. This leads to changes in speed, orientation, and pattern evolution, following the underlying excitability of the signal transduction system. Our findings emphasize the role of the plasma membrane topology in reaction-diffusion-driven biological systems and indicate its importance in other mammalian systems.
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Affiliation(s)
- Marcel Hörning
- Laboratory for Physical Biology, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan; Institute of Biomaterials and Biomolecular Systems, University of Stuttgart, Stuttgart, Germany; Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto, Japan.
| | - Tatsuo Shibata
- Laboratory for Physical Biology, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan.
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Mallikarjunaiah KJ, Kinnun JJ, Petrache HI, Brown MF. Flexible lipid nanomaterials studied by NMR spectroscopy. Phys Chem Chem Phys 2019; 21:18422-18457. [DOI: 10.1039/c8cp06179c] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Advances in solid-state nuclear magnetic resonance spectroscopy inform the emergence of material properties from atomistic-level interactions in membrane lipid nanostructures.
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Affiliation(s)
- K. J. Mallikarjunaiah
- Department of Chemistry and Biochemistry
- University of Arizona
- Tucson
- USA
- Department of Physics
| | - Jacob J. Kinnun
- Department of Physics
- Indiana University-Purdue University
- Indianapolis
- USA
| | - Horia I. Petrache
- Department of Physics
- Indiana University-Purdue University
- Indianapolis
- USA
| | - Michael F. Brown
- Department of Chemistry and Biochemistry
- University of Arizona
- Tucson
- USA
- Department of Physics
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