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Danielewicz N, Rosato F, Dai W, Römer W, Turnbull WB, Mairhofer J. Microbial carbohydrate-binding toxins – From etiology to biotechnological application. Biotechnol Adv 2022; 59:107951. [DOI: 10.1016/j.biotechadv.2022.107951] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 03/22/2022] [Accepted: 04/02/2022] [Indexed: 02/06/2023]
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2
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Smith JM, Chowdhry R, Booth MJ. Controlling Synthetic Cell-Cell Communication. Front Mol Biosci 2022; 8:809945. [PMID: 35071327 PMCID: PMC8766733 DOI: 10.3389/fmolb.2021.809945] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 12/13/2021] [Indexed: 11/28/2022] Open
Abstract
Synthetic cells, which mimic cellular function within a minimal compartment, are finding wide application, for instance in studying cellular communication and as delivery devices to living cells. However, to fully realise the potential of synthetic cells, control of their function is vital. An array of tools has already been developed to control the communication of synthetic cells to neighbouring synthetic cells or living cells. These tools use either chemical inputs, such as small molecules, or physical inputs, such as light. Here, we examine these current methods of controlling synthetic cell communication and consider alternative mechanisms for future use.
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Affiliation(s)
| | | | - Michael J. Booth
- Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
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3
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Rockinger U, Funk M, Winter G. Current Approaches of Preservation of Cells During (freeze-) Drying. J Pharm Sci 2021; 110:2873-2893. [PMID: 33933434 DOI: 10.1016/j.xphs.2021.04.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 03/13/2021] [Accepted: 04/20/2021] [Indexed: 11/20/2022]
Abstract
The widespread application of therapeutic cells requires a successful stabilization of cells for the duration of transport and storage. Cryopreservation is currently considered the gold standard for the storage of active cells; however, (freeze-) drying cells could enable higher shelf life stability at ambient temperatures and facilitate easier transport and storage. During (freeze-) drying, freezing, (primary and secondary) drying and also the reconstitution step pose the risk of potential cell damage. To prevent these damaging processes, a wide range of protecting excipients has emerged, which can be classified, according to their chemical affiliation, into sugars, macromolecules, polyols, antioxidants and chelating agents. As many excipients cannot easily permeate the cell membrane, researchers have established various techniques to introduce especially trehalose intracellularly, prior to drying. This review aims to summarize the main damaging mechanisms during (freeze-) drying and to introduce the most common excipients with further details on their stabilizing properties and process approaches for the intracellular loading of excipients. Additionally, we would like to briefly explain recently discovered advantages of drying microorganisms, sperm, platelets, red blood cells, and eukaryotic cells, paying particular attention to the drying technique and residual moisture content.
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Affiliation(s)
- Ute Rockinger
- Ludwig-Maximilians-Universität München, Department of Pharmacy, Pharmaceutical Technology and Biopharmaceutics, Munich, Germany.
| | - Martin Funk
- QRSKIN GmbH, Friedrich-Bergius-Ring 15, Würzburg, Germany
| | - Gerhard Winter
- Ludwig-Maximilians-Universität München, Department of Pharmacy, Pharmaceutical Technology and Biopharmaceutics, Munich, Germany
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4
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Huang J, Guo J, Zhou L, Zheng G, Cao J, Li Z, Zhou Z, Lei Q, Brinker CJ, Zhu W. Advanced Nanomaterials-Assisted Cell Cryopreservation: A Mini Review. ACS APPLIED BIO MATERIALS 2021; 4:2996-3014. [PMID: 35014388 DOI: 10.1021/acsabm.1c00105] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cell cryopreservation is of vital significance both for transporting and storing cells before experimental/clinical use. Cryoprotectants (CPAs) are necessary additives in the preserving medium in cryopreservation, preventing cells from freeze-thaw injuries. Traditional organic solvents have been widely used in cell cryopreservation for decades. Given the obvious damage to cells due to their undesirable cytotoxicity and the burdensome post-thaw washing cycles before use, traditional CPAs are more and more likely to be replaced by modern ones with lower toxicity, less processing, and higher efficiency. As materials science thrives, nanomaterials are emerging to serve as potent vehicles for delivering nontoxic CPAs or inherent CPAs comparable to or even superior to conventional ones. This review will introduce some advanced nanomaterials (e.g., organic/inorganic nanoCPAs, nanodelivery systems) utilized for cell cryopreservation, providing broader insights into this developing field.
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Affiliation(s)
- Junda Huang
- MOE International Joint Research Laboratory on Synthetic Biology and Medicines, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, P. R. China
| | - Jimin Guo
- Center for Micro-Engineered Materials, Department of Chemical and Biological Engineering, The University of New Mexico, Albuquerque, New Mexico 87131, United States.,Department of Internal Medicine, Molecular Medicine, The University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Liang Zhou
- MOE International Joint Research Laboratory on Synthetic Biology and Medicines, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, P. R. China
| | - Guansheng Zheng
- MOE International Joint Research Laboratory on Synthetic Biology and Medicines, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, P. R. China
| | - Jiangfan Cao
- MOE International Joint Research Laboratory on Synthetic Biology and Medicines, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, P. R. China
| | - Zeyu Li
- MOE International Joint Research Laboratory on Synthetic Biology and Medicines, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, P. R. China
| | - Zhuang Zhou
- MOE International Joint Research Laboratory on Synthetic Biology and Medicines, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, P. R. China
| | - Qi Lei
- MOE International Joint Research Laboratory on Synthetic Biology and Medicines, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, P. R. China
| | - C Jeffrey Brinker
- Center for Micro-Engineered Materials, Department of Chemical and Biological Engineering, The University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Wei Zhu
- MOE International Joint Research Laboratory on Synthetic Biology and Medicines, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, P. R. China
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5
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Temporary Membrane Permeabilization via the Pore-Forming Toxin Lysenin. Toxins (Basel) 2020; 12:toxins12050343. [PMID: 32456013 PMCID: PMC7290483 DOI: 10.3390/toxins12050343] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 05/17/2020] [Accepted: 05/20/2020] [Indexed: 12/19/2022] Open
Abstract
Pore-forming toxins are alluring tools for delivering biologically-active, impermeable cargoes to intracellular environments by introducing large conductance pathways into cell membranes. However, the lack of regulation often leads to the dissipation of electrical and chemical gradients, which might significantly affect the viability of cells under scrutiny. To mitigate these problems, we explored the use of lysenin channels to reversibly control the barrier function of natural and artificial lipid membrane systems by controlling the lysenin's transport properties. We employed artificial membranes and electrophysiology measurements in order to identify the influence of labels and media on the lysenin channel's conductance. Two cell culture models: Jurkat cells in suspension and adherent ATDC5 cells were utilized to demonstrate that lysenin channels may provide temporary cytosol access to membrane non-permeant propidium iodide and phalloidin. Permeability and cell viability were assessed by fluorescence spectroscopy and microscopy. Membrane resealing by chitosan or specific media addition proved to be an effective way of maintaining cellular viability. In addition, we loaded non-permeant dyes into liposomes via lysenin channels by controlling their conducting state with multivalent metal cations. The improved control over membrane permeability might prove fruitful for a large variety of biological or biomedical applications that require only temporary, non-destructive access to the inner environment enclosed by natural and artificial membranes.
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6
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Yang J, Gao L, Liu M, Sui X, Zhu Y, Wen C, Zhang L. Advanced Biotechnology for Cell Cryopreservation. ACTA ACUST UNITED AC 2019. [DOI: 10.1007/s12209-019-00227-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
AbstractCell cryopreservation has evolved as an important technology required for supporting various cell-based applications, such as stem cell therapy, tissue engineering, and assisted reproduction. Recent times have witnessed an increase in the clinical demand of these applications, requiring urgent improvements in cell cryopreservation. However, cryopreservation technology suffers from the issues of low cryopreservation efficiency and cryoprotectant (CPA) toxicity. Application of advanced biotechnology tools can significantly improve post-thaw cell survival and reduce or even eliminate the use of organic solvent CPAs, thus promoting the development of cryopreservation. Herein, based on the different cryopreservation mechanisms available, we provide an overview of the applications and achievements of various biotechnology tools used in cell cryopreservation, including trehalose delivery, hydrogel-based cell encapsulation technique, droplet-based cell printing, and nanowarming, and also discuss the associated challenges and perspectives for future development.
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7
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Controlled deprotection and release of a small molecule from a compartmented synthetic tissue module. Commun Chem 2019. [DOI: 10.1038/s42004-019-0244-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
AbstractSynthetic tissues built from communicating aqueous droplets offer potential applications in biotechnology, however, controlled release of their contents has not been achieved. Here we construct two-droplet synthetic tissue modules that function in an aqueous environment. One droplet contains a cell-free protein synthesis system and a prodrug-activating enzyme and the other a small-molecule prodrug analog. When a Zn2+-sensitive protein pore is made in the first droplet, it allows the prodrug to migrate from the second droplet and become activated by the enzyme. With Zn2+ in the external medium, the activated molecule is retained in the module until it is released on-demand by a divalent cation chelator. The module is constructed in such a manner that one or more, potentially with different properties, might be incorporated into extended synthetic tissues, including patterned materials generated by 3D-printing. Such modules will thereby increase the sophistication of synthetic tissues for applications including controlled multidrug delivery.
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8
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Zhang Y, Wang H, Stewart S, Jiang B, Ou W, Zhao G, He X. Cold-Responsive Nanoparticle Enables Intracellular Delivery and Rapid Release of Trehalose for Organic-Solvent-Free Cryopreservation. NANO LETTERS 2019; 19:9051-9061. [PMID: 31680526 DOI: 10.1021/acs.nanolett.9b04109] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Conventional cryopreservation of mammalian cells requires the use of toxic organic solvents (e.g., dimethyl sulfoxide) as cryoprotectants. Consequently, the cryopreserved cells must undergo a tedious washing procedure to remove the organic solvents for their further applications in cell-based medicine, and many of the precious cells may be lost or killed during the procedure. Trehalose has been explored as a nontoxic alternative to traditional cryoprotectants. However, mammalian cells do not synthesize trehalose or express trehalose transporters in their membranes, and the lack of an approach for the efficient intracellular delivery of trehalose has been a major hurdle for its use in cell cryopreservation. In this study, a cold-responsive polymer (poly(N-isopropylacrylamide-co-butyl acrylate)) is utilized to synthesize nanoparticles for the encapsulation and intracellular delivery of trehalose. The trehalose-laden nanoparticles can be efficiently taken up by mammalian cells. The nanoparticles quickly and irreversibly disassemble upon cold treatment, enabling the controlled and rapid release of trehalose from the nanoparticles inside cells. The latter is confirmed by an evident increase in cell volume upon cold treatment. This rapid cold-triggered intracellular release of trehalose is crucial to developing a fast protocol to cryopreserve cells using trehalose. Cells with intracellular trehalose delivered using the nanoparticles show comparable postcryopreservation viability compared to that of cells treated with DMSO, eliminating the need for the tedious and cell-damaging washing procedure required for using the DMSO-cryopreserved cells in vivo. This cold-responsive nanoparticle may greatly facilitate the use of trehalose as a nontoxic cryoprotectant for banking cells and tissues to meet their high demand by modern cell-based medicine.
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Affiliation(s)
- Yuntian Zhang
- Department of Electronic Science and Technology , University of Science and Technology of China , Hefei , Anhui 230027 , China
| | - Hai Wang
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, CAS Center for Excellence in Nanoscience , National Center for Nanoscience and Technology , Beijing 100190 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | | | | | | | - Gang Zhao
- Department of Electronic Science and Technology , University of Science and Technology of China , Hefei , Anhui 230027 , China
| | - Xiaoming He
- Marlene and Stewart Greenebaum Comprehensive Cancer Center , University of Maryland , Baltimore , Maryland 21201 , United States
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9
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Uchida T, Furukawa M, Kikawada T, Yamazaki K, Gohara K. Trehalose uptake and dehydration effects on the cryoprotection of CHO–K1 cells expressing TRET1. Cryobiology 2019; 90:30-40. [DOI: 10.1016/j.cryobiol.2019.09.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 09/02/2019] [Accepted: 09/03/2019] [Indexed: 10/26/2022]
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10
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Blümel E, Willerslev-Olsen A, Gluud M, Lindahl LM, Fredholm S, Nastasi C, Krejsgaard T, Surewaard BGJ, Koralov SB, Hu T, Persson JL, Bonefeld CM, Geisler C, Iversen L, Becker JC, Andersen MH, Woetmann A, Buus TB, Ødum N. Staphylococcal alpha-toxin tilts the balance between malignant and non-malignant CD4 + T cells in cutaneous T-cell lymphoma. Oncoimmunology 2019; 8:e1641387. [PMID: 31646088 PMCID: PMC6791457 DOI: 10.1080/2162402x.2019.1641387] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 06/03/2019] [Accepted: 07/02/2019] [Indexed: 02/08/2023] Open
Abstract
Staphylococcus aureus is implicated in disease progression in cutaneous T-cell lymphoma (CTCL). Here, we demonstrate that malignant T cell lines derived from CTCL patients as well as primary malignant CD4+ T cells from Sézary syndrome patients are considerably more resistant to alpha-toxin-induced cell death than their non-malignant counterparts. Thus, in a subset of Sézary syndrome patients the ratio between malignant and non-malignant CD4+ T cells increases significantly following exposure to alpha-toxin. Whereas toxin-induced cell death is ADAM10 dependent in healthy CD4+ T cells, resistance to alpha-toxin in malignant T cells involves both downregulation of ADAM10 as well as other resistance mechanisms. In conclusion, we provide first evidence that Staphylococcus aureus derived alpha-toxin can tilt the balance between malignant and non-malignant CD4+ T cells in CTCL patients. Consequently, alpha-toxin may promote disease progression through positive selection of malignant CD4+ T cells, identifying alpha-toxin as a putative drug target in CTCL.
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Affiliation(s)
- Edda Blümel
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Andreas Willerslev-Olsen
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Maria Gluud
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Lise M. Lindahl
- Department of Dermatology, Aarhus University Hospital, Aarhus, Denmark
| | - Simon Fredholm
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Claudia Nastasi
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Thorbjørn Krejsgaard
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Bas G. J. Surewaard
- Department of Physiology and Pharmacology, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Canada
| | - Sergei B. Koralov
- Department of Pathology, New York University School of Medicine, New York, NY, USA
| | - Tengpeng Hu
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Jenny L. Persson
- Clinical Research Center, Lund University, Lund, Sweden
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Charlotte Menné Bonefeld
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Carsten Geisler
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Lars Iversen
- Department of Dermatology, Aarhus University Hospital, Aarhus, Denmark
| | - Jürgen C. Becker
- Translational Skin Cancer Research, German Cancer Consortium (DKTK), University Hospital Essen and Deutsches Krebsforschungszentrum (DKFZ), Essen, Germany
| | - Mads Hald Andersen
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Center for Cancer Immune Therapy (CCIT), Department of Hematology and Oncology, Copenhagen University Hospital, Herlev Hospital, Herlev, Denmark
| | - Anders Woetmann
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Terkild Brink Buus
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Niels Ødum
- LEO Foundation Skin Immunology Research Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
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11
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Stewart S, He X. Intracellular Delivery of Trehalose for Cell Banking. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:7414-7422. [PMID: 30078320 PMCID: PMC6382607 DOI: 10.1021/acs.langmuir.8b02015] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Advances in stem cell technology and regenerative medicine have underscored the need for effective banking of living cells. Cryopreservation, using very low temperatures to achieve suspended animation, is widely used to store or bank cells for later use. This process requires the use of cryoprotective agents (CPAs) to protect cells against damage caused by the cooling and warming process. However, current popular CPAs like DMSO can be toxic to cells and must be thoroughly removed from cells before they can be used for research or clinical applications. Trehalose, a nontoxic sugar found in organisms capable of withstanding extreme cold or desiccation, has been explored as an alternative CPA. The disaccharide must be present on both sides of the cellular membrane to provide cryo-protection. However, trehalose is not synthesized by mammalian cells nor has the capability to diffuse through their plasma membranes. Therefore, it is crucial to achieve intracellular delivery of trehalose for utilizing the full potential of the sugar for cell banking. In this review, various methods that have been explored to deliver trehalose into mammalian cells for their banking at both cryogenic and ambient temperatures are surveyed. Among them, the nanoparticle-mediated approach is particularly exciting. Collectively, studies in the literature demonstrate the great potential of using trehalose as the sole CPA for cell banking, to facilitate the widespread use of living cells in modern medicine.
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Affiliation(s)
| | - Xiaoming He
- Correspondence should be addressed to: Xiaoming He, Ph.D., Fischell Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States.,
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12
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Stewart MP, Langer R, Jensen KF. Intracellular Delivery by Membrane Disruption: Mechanisms, Strategies, and Concepts. Chem Rev 2018; 118:7409-7531. [PMID: 30052023 PMCID: PMC6763210 DOI: 10.1021/acs.chemrev.7b00678] [Citation(s) in RCA: 382] [Impact Index Per Article: 63.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Intracellular delivery is a key step in biological research and has enabled decades of biomedical discoveries. It is also becoming increasingly important in industrial and medical applications ranging from biomanufacture to cell-based therapies. Here, we review techniques for membrane disruption-based intracellular delivery from 1911 until the present. These methods achieve rapid, direct, and universal delivery of almost any cargo molecule or material that can be dispersed in solution. We start by covering the motivations for intracellular delivery and the challenges associated with the different cargo types-small molecules, proteins/peptides, nucleic acids, synthetic nanomaterials, and large cargo. The review then presents a broad comparison of delivery strategies followed by an analysis of membrane disruption mechanisms and the biology of the cell response. We cover mechanical, electrical, thermal, optical, and chemical strategies of membrane disruption with a particular emphasis on their applications and challenges to implementation. Throughout, we highlight specific mechanisms of membrane disruption and suggest areas in need of further experimentation. We hope the concepts discussed in our review inspire scientists and engineers with further ideas to improve intracellular delivery.
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Affiliation(s)
- Martin P. Stewart
- Department of Chemical Engineering, Massachusetts Institute
of Technology, Cambridge, USA
- The Koch Institute for Integrative Cancer Research,
Massachusetts Institute of Technology, Cambridge, USA
| | - Robert Langer
- Department of Chemical Engineering, Massachusetts Institute
of Technology, Cambridge, USA
- The Koch Institute for Integrative Cancer Research,
Massachusetts Institute of Technology, Cambridge, USA
| | - Klavs F. Jensen
- Department of Chemical Engineering, Massachusetts Institute
of Technology, Cambridge, USA
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13
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Yang J, Pan C, Zhang J, Sui X, Zhu Y, Wen C, Zhang L. Exploring the Potential of Biocompatible Osmoprotectants as Highly Efficient Cryoprotectants. ACS APPLIED MATERIALS & INTERFACES 2017; 9:42516-42524. [PMID: 29161015 DOI: 10.1021/acsami.7b12189] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Cryoprotectants (CPAs) are critical to successful cryopreservation because they can protect cells from cryoinjuries. Because of the limitations of current CPAs, especially the toxicity, the search for new effective CPAs is attracting increasing attention. In this work, we reported that natural biocompatible osmoprotectants, which could protect cells from osmotic injury in various biological systems, might also be ideal candidates for CPAs. Three representative biocompatible osmoprotectants (proline, glycine, and taurine) were tested and compared. It was found that, aside from presenting a different ability to prevent osmotic injury, these biocompatible osmoprotectants also possessed a different ability to inhibit ice formation and thus mitigate intra-/extracellular ice injury. Because of the strongest ability to prevent the two types of injuries, we found that proline performed the best in cryopreserving five different types of cells. Moreover, the natural osmoprotectants are intrinsically biocompatible with the cells, superior to the current state-of-the-art CPA, dimethyl sulfoxide (DMSO), which is a toxic organic solvent. This work opens a new window of opportunity for DMSO-free cryopreservation, and sheds light on the applications of osmoprotectants in cryoprotection, which may revolutionize the current cryopreservation technologies.
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Affiliation(s)
- Jing Yang
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Key Laboratory of Systems Bioengineering of the Ministry of Education, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University , Tianjin 300072, P. R. China
| | - Chao Pan
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Key Laboratory of Systems Bioengineering of the Ministry of Education, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University , Tianjin 300072, P. R. China
| | - Jiamin Zhang
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Key Laboratory of Systems Bioengineering of the Ministry of Education, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University , Tianjin 300072, P. R. China
| | - Xiaojie Sui
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Key Laboratory of Systems Bioengineering of the Ministry of Education, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University , Tianjin 300072, P. R. China
| | - Yingnan Zhu
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Key Laboratory of Systems Bioengineering of the Ministry of Education, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University , Tianjin 300072, P. R. China
| | - Chiyu Wen
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Key Laboratory of Systems Bioengineering of the Ministry of Education, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University , Tianjin 300072, P. R. China
| | - Lei Zhang
- Department of Biochemical Engineering, School of Chemical Engineering and Technology, Key Laboratory of Systems Bioengineering of the Ministry of Education, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University , Tianjin 300072, P. R. China
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14
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Uchida T, Furukawa M, Kikawada T, Yamazaki K, Gohara K. Intracellular trehalose via transporter TRET1 as a method to cryoprotect CHO-K1 cells. Cryobiology 2017; 77:50-57. [DOI: 10.1016/j.cryobiol.2017.05.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 05/09/2017] [Accepted: 05/22/2017] [Indexed: 11/30/2022]
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15
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Abazari A, Meimetis LG, Budin G, Bale SS, Weissleder R, Toner M. Engineered Trehalose Permeable to Mammalian Cells. PLoS One 2015; 10:e0130323. [PMID: 26115179 PMCID: PMC4482662 DOI: 10.1371/journal.pone.0130323] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 05/19/2015] [Indexed: 01/09/2023] Open
Abstract
Trehalose is a naturally occurring disaccharide which is associated with extraordinary stress-tolerance capacity in certain species of unicellular and multicellular organisms. In mammalian cells, presence of intra- and extracellular trehalose has been shown to confer improved tolerance against freezing and desiccation. Since mammalian cells do not synthesize nor import trehalose, the development of novel methods for efficient intracellular delivery of trehalose has been an ongoing investigation. Herein, we studied the membrane permeability of engineered lipophilic derivatives of trehalose. Trehalose conjugated with 6 acetyl groups (trehalose hexaacetate or 6-O-Ac-Tre) demonstrated superior permeability in rat hepatocytes compared with regular trehalose, trehalose diacetate (2-O-Ac-Tre) and trehalose tetraacetate (4-O-Ac-Tre). Once in the cell, intracellular esterases hydrolyzed the 6-O-Ac-Tre molecules, releasing free trehalose into the cytoplasm. The total concentration of intracellular trehalose (plus acetylated variants) reached as high as 10 fold the extracellular concentration of 6-O-Ac-Tre, attaining concentrations suitable for applications in biopreservation. To describe this accumulation phenomenon, a diffusion-reaction model was proposed and the permeability and reaction kinetics of 6-O-Ac-Tre were determined by fitting to experimental data. Further studies suggested that the impact of the loading and the presence of intracellular trehalose on cellular viability and function were negligible. Engineering of trehalose chemical structure rather than manipulating the cell, is an innocuous, cell-friendly method for trehalose delivery, with demonstrated potential for trehalose loading in different types of cells and cell lines, and can facilitate the wide-spread application of trehalose as an intracellular protective agent in biopreservation studies.
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Affiliation(s)
- Alireza Abazari
- The Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, and Shriners Hospital for Children, Boston, Massachusetts, United States of America
| | - Labros G. Meimetis
- The Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Ghyslain Budin
- The Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Shyam Sundhar Bale
- The Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, and Shriners Hospital for Children, Boston, Massachusetts, United States of America
| | - Ralph Weissleder
- The Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Mehmet Toner
- The Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, and Shriners Hospital for Children, Boston, Massachusetts, United States of America
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16
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Miller DM, Gulbis JM. Engineering protocells: prospects for self-assembly and nanoscale production-lines. Life (Basel) 2015; 5:1019-53. [PMID: 25815781 PMCID: PMC4500129 DOI: 10.3390/life5021019] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2015] [Revised: 03/09/2015] [Accepted: 03/16/2015] [Indexed: 11/16/2022] Open
Abstract
The increasing ease of producing nucleic acids and proteins to specification offers potential for design and fabrication of artificial synthetic "organisms" with a myriad of possible capabilities. The prospects for these synthetic organisms are significant, with potential applications in diverse fields including synthesis of pharmaceuticals, sources of renewable fuel and environmental cleanup. Until now, artificial cell technology has been largely restricted to the modification and metabolic engineering of living unicellular organisms. This review discusses emerging possibilities for developing synthetic protocell "machines" assembled entirely from individual biological components. We describe a host of recent technological advances that could potentially be harnessed in design and construction of synthetic protocells, some of which have already been utilized toward these ends. More elaborate designs include options for building self-assembling machines by incorporating cellular transport and assembly machinery. We also discuss production in miniature, using microfluidic production lines. While there are still many unknowns in the design, engineering and optimization of protocells, current technologies are now tantalizingly close to the capabilities required to build the first prototype protocells with potential real-world applications.
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Affiliation(s)
- David M Miller
- The Walter and Eliza Hall Institute of Medical Research, Parkville VIC 3052, Australia.
- Department of Medical Biology, The University of Melbourne, Parkville VIC 3052, Australia.
| | - Jacqueline M Gulbis
- The Walter and Eliza Hall Institute of Medical Research, Parkville VIC 3052, Australia.
- Department of Medical Biology, The University of Melbourne, Parkville VIC 3052, Australia.
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17
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Oliver AE. Dry state preservation of nucleated cells: progress and challenges. Biopreserv Biobank 2015; 10:376-85. [PMID: 24849888 DOI: 10.1089/bio.2012.0020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Effective stabilization of nucleated cells for dry storage would be a transformative development in the field of cell-based biosensors and biotechnologic devices, as well as regenerative medicine and other areas in which stem cells have clinical utility. Ultimately, the tremendous promise of cell-based products will only be fully realized when stable long-term storage becomes available without the use of liquid nitrogen and bulky, energetically expensive freezers. Significant progress has been made over the last 10 years toward this goal, but obstacles still remain. Loading cells with the protective disaccharide trehalose has been achieved by several different techniques and has been shown to increase cell survival at low water contents. Likewise, the protective effect of heat shock proteins and other compounds have also been explored alone and in combination with trehalose. In some cases, the benefit of these molecules is seen not initially upon rehydration, but over time during cellular recovery. Other considerations, such as inhibiting apoptosis and utilizing isotonic buffer conditions have also provided stepwise increases in cell viability and function following drying and rehydration. In all these cases, however, a low level of residual water is required to achieve viability after rehydration. The most significant remaining challenge is to protect nucleated cells such that this residual water can be safely removed, thus allowing vitrification of intra- and extracellular trehalose and stable dry state storage at room temperature.
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Affiliation(s)
- Ann E Oliver
- Department of Biomedical Engineering, University of California , Davis, California
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18
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Hildebrandt JP. Pore-forming virulence factors of Staphylococcus aureus destabilize epithelial barriers-effects of alpha-toxin in the early phases of airway infection. AIMS Microbiol 2015. [DOI: 10.3934/microbiol.2015.1.11] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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19
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Cationic polymers inhibit the conductance of lysenin channels. ScientificWorldJournal 2013; 2013:316758. [PMID: 24191139 PMCID: PMC3804441 DOI: 10.1155/2013/316758] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Accepted: 09/12/2013] [Indexed: 11/29/2022] Open
Abstract
The pore-forming toxin lysenin self-assembles large and stable conductance channels in natural and artificial lipid membranes. The lysenin channels exhibit unique regulation capabilities, which open unexplored possibilities to control the transport of ions and molecules through artificial and natural lipid membranes. Our investigations demonstrate that the positively charged polymers polyethyleneimine and chitosan inhibit the conducting properties of lysenin channels inserted into planar lipid membranes. The preservation of the inhibitory effect following addition of charged polymers on either side of the supporting membrane suggests the presence of multiple binding sites within the channel's structure and a multistep inhibition mechanism that involves binding and trapping. Complete blockage of the binding sites with divalent cations prevents further inhibition in conductance induced by the addition of cationic polymers and supports the hypothesis that the binding sites are identical for both multivalent metal cations and charged polymers. The investigation at the single-channel level has shown distinct complete blockages of each of the inserted channels. These findings reveal key structural characteristics which may provide insight into lysenin's functionality while opening innovative approaches for the development of applications such as transient cell permeabilization and advanced drug delivery systems.
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Abstract
Realization of a functional artificial cell, the so-called protocell, is a major challenge posed by synthetic biology. A subsequent goal is to use the protocellular units for the bottom-up assembly of prototissues. There is, however, a looming chasm in our knowledge between protocells and prototissues. In the present paper, we give a brief overview of the work on protocells to date, followed by a discussion on the rational design of key structural elements specific to linking two protocellular bilayers. We propose that designing synthetic parts capable of simultaneous insertion into two bilayers may be crucial in the hierarchical assembly of protocells into a functional prototissue.
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21
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Lechene CP, Lee GY, Poczatek JC, Toner M, Biggers JD. 3D multi-isotope imaging mass spectrometry reveals penetration of 18O-trehalose in mouse sperm nucleus. PLoS One 2012; 7:e42267. [PMID: 22952592 PMCID: PMC3428319 DOI: 10.1371/journal.pone.0042267] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Accepted: 07/02/2012] [Indexed: 11/20/2022] Open
Abstract
The prevalence of genetically engineered mice in medical research has led to ever increasing storage costs. Trehalose has a significant beneficial effect in preserving the developmental potential of mouse sperm following partial desiccation and storage at temperatures above freezing. Using multi-isotope imaging mass spectrometry, we are able to image and measure trehalose in individual spermatozoa. We provide the first evidence that trehalose penetrates the nucleus of a mammalian cell, permitting tolerance to desiccation. These results have broad implications for long-term storage of mammalian cells.
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Affiliation(s)
- Claude P Lechene
- National Resource for Imaging Mass Spectrometry, Division of Genetics, Harvard Medical School, Brigham and Women's Hospital, Cambridge, Massachusetts, United States of America.
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22
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Chakraborty N, Menze MA, Elmoazzen H, Vu H, Yarmush ML, Hand SC, Toner M. Trehalose transporter from African chironomid larvae improves desiccation tolerance of Chinese hamster ovary cells. Cryobiology 2012; 64:91-6. [PMID: 22155480 PMCID: PMC3275667 DOI: 10.1016/j.cryobiol.2011.11.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Revised: 11/23/2011] [Accepted: 11/24/2011] [Indexed: 11/15/2022]
Abstract
Dry preservation has been explored as an energy-efficient alternative to cryopreservation, but the high sensitivity of mammalian cells to desiccation stress has been one of the major hurdles in storing cells in the desiccated state. An important strategy to reduce desiccation sensitivity involves use of the disaccharide trehalose. Trehalose is known to improve desiccation tolerance in mammalian cells when present on both sides of the cell membrane. Because trehalose is membrane impermeant the development of desiccation strategies involving this promising sugar is hindered. We explored the potential of using a high-capacity trehalose transporter (TRET1) from the African chironomid Polypedilum vanderplanki[21] to introduce trehalose into the cytoplasm of mammalian cells and thereby increase desiccation tolerance. When Chinese hamster ovary cells (CHO) were stably transfected with TRET1 (CHO-TRET1 cells) and incubated with 0.4M trehalose for 4h at 37°C, a sevenfold increase in trehalose uptake was observed compared to the wild-type CHO cells. Following trehalose loading, desiccation tolerance was investigated by evaporative drying of cells at 14% relative humidity. After desiccation to 2.60g of water per gram dry weight, a 170% increase in viability and a 400% increase in growth (after 7days) was observed for CHO-TRET1 relative to control CHO cells. Our results demonstrate the beneficial effect of intracellular trehalose for imparting tolerance to partial desiccation.
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Affiliation(s)
- Nilay Chakraborty
- Center for Engineering in Medicine and BioMEMS Resource Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
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23
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Ishitsuka Y, Okumus B, Arslan S, Chen KH, Ha T. Temperature-independent porous nanocontainers for single-molecule fluorescence studies. Anal Chem 2010; 82:9694-701. [PMID: 21038883 DOI: 10.1021/ac101714u] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this work, we demonstrate the capability of using lipid vesicles biofunctionalized with protein channels to perform single-molecule fluorescence measurements over a biologically relevant temperature range. Lipid vesicles can serve as an ideal nanocontainer for single-molecule fluorescence measurements of biomacromolecules. One serious limitation of the vesicle encapsulation method has been that the lipid membrane is practically impermeable to most ions and small molecules, limiting its application to observing reactions in equilibrium with the initial buffer condition. To permeabilize the barrier, Staphylococcus aureus toxin α-hemolysin (aHL) channels have been incorporated into the membrane. These aHL channels have been characterized using single-molecule fluorescence resonance energy transfer signals from vesicle-encapsulated guanine-rich DNA that folds in a G-quadruplex motif as well as from the Rep helicase-DNA system. We show that these aHL channels are permeable to monovalent ions and small molecules, such as ATP, over the biologically relevant temperature range (17-37 °C). Ions can efficiently pass through preformed aHL channels to initiate DNA folding without any detectable delay. With addition of the cholesterol to the membrane, we also report a 35-fold improvement in the aHL channel formation efficiency, making this approach more practical for wider applications. Finally, the temperature-dependent single-molecule enzymatic study inside these nanocontainers is demonstrated by measuring the Rep helicase repetitive shuttling dynamics along a single-stranded DNA at various temperatures. The permeability of the biofriendly nanocontainer over a wide range of temperature would be effectively applied to other surface-based high-throughput measurements and sensors beyond the single-molecule fluorescence measurements.
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Affiliation(s)
- Yuji Ishitsuka
- Department of Physics, Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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24
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Lebeda FJ, Singh BR. Membrane Channel activity and Translocation of Tetanus and Botulinum Neurotoxins. ACTA ACUST UNITED AC 2010. [DOI: 10.3109/15569549909036017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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25
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Preservation of differentiation and clonogenic potential of human hematopoietic stem and progenitor cells during lyophilization and ambient storage. PLoS One 2010; 5. [PMID: 20824143 PMCID: PMC2931707 DOI: 10.1371/journal.pone.0012518] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2010] [Accepted: 07/20/2010] [Indexed: 01/19/2023] Open
Abstract
Progenitor cell therapies show great promise, but their potential for clinical applications requires improved storage and transportation. Desiccated cells stored at ambient temperature would provide economic and practical advantages over approaches employing cell freezing and subzero temperature storage. The objectives of this study were to assess a method for loading the stabilizing sugar, trehalose, into hematopoietic stem and progenitor cells (HPC) and to evaluate the effects of subsequent freeze-drying and storage at ambient temperature on differentiation and clonogenic potential. HPC were isolated from human umbilical cord blood and loaded with trehalose using an endogenous cell surface receptor, termed P2Z. Solution containing trehalose-loaded HPC was placed into vials, which were transferred to a tray freeze-dryer and removed during each step of the freeze-drying process to assess differentiation and clonogenic potential. Control groups for these experiments were freshly isolated HPC. Control cells formed 1450+/-230 CFU-GM, 430+/-140 BFU-E, and 50+/-40 CFU-GEMM per 50 microL. Compared to the values for the control cells, there was no statistical difference observed for cells removed at the end of the freezing step or at the end of primary drying. There was a gradual decrease in the number of CFU-GM and BFU-E for cells removed at different temperatures during secondary drying; however, there were no significant differences in the number of CFU-GEMM. To determine storage stability of lyophilized HPC, cells were stored for 4 weeks at 25 degrees C in the dark. Cells reconstituted immediately after lyophilization produced 580+/-90 CFU-GM ( approximately 40%, relative to unprocessed controls p<0.0001), 170+/-70 BFU-E (approximately 40%, p<0.0001), and 41+/-22 CFU-GEMM (approximately 82%, p = 0.4171), and cells reconstituted after 28 days at room temperature produced 513+/-170 CFU-GM (approximately 35%, relative to unprocessed controls, p<0.0001), 112+/-68 BFU-E (approximately 26%, p<0.0001), and 36+/-17 CFU-GEMM ( approximately 82%, p = 0.2164) These studies are the first to document high level retention of CFU-GEMM following lyophilization and storage for 4 weeks at 25 degrees C. This type of flexible storage stability would potentially permit the ability to ship and store HPC without the need for refrigeration.
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26
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Okumus B, Arslan S, Fengler SM, Myong S, Ha T. Single molecule nanocontainers made porous using a bacterial toxin. J Am Chem Soc 2010; 131:14844-9. [PMID: 19788247 PMCID: PMC2761729 DOI: 10.1021/ja9042356] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
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Encapsulation of a biological molecule or a molecular complex in a vesicle provides a means of biofriendly immobilization for single molecule studies and further enables new types of analysis if the vesicles are permeable. We previously reported on using DMPC (dimyristoylphosphatidylcholine) vesicles for realizing porous bioreactors. Here, we describe a different strategy for making porous vesicles using a bacterial pore-forming toxin, α-hemolysin. Using RNA folding as a test case, we demonstrate that protein-based pores can allow exchange of magnesium ions through the vesicle wall while keeping the RNA molecule inside. Flow measurements indicate that the encapsulated RNA molecules rapidly respond to the change in the outside buffer condition. The approach was further tested by coencapsulating a helicase protein and its single-stranded DNA track. The DNA translocation activity of E. coli Rep helicase inside vesicles was fueled by ATP provided outside the vesicle, and a dramatically higher number of translocation cycles could be observed due to the minuscule vesicle volume that facilitates rapid rebinding after dissociation. These pores are known to be stable over a wide range of experimental conditions, especially at various temperatures, which is not possible with the previous method using DMPC vesicles. Moreover, engineered mutants of the utilized toxin can potentially be exploited in the future applications.
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Affiliation(s)
- Burak Okumus
- Center for Biophysics and Computational Biology, University of Illinois, Urbana, Illinois 61801, USA
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27
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Abstract
Integral membrane proteins are important biological macromolecules with structural features and functionalities that make them attractive targets for nanotechnology. I provide here a broad review of current activity in nanotechnology related to membrane proteins, including their application as nanoscale sensors, switches, components of optical devices and as templates for self-assembled arrays.
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28
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Chakraborty N, Biswas D, Parker W, Moyer P, Elliott GD. A role for microwave processing in the dry preservation of mammalian cells. Biotechnol Bioeng 2008; 100:782-96. [DOI: 10.1002/bit.21801] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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29
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Norris MM, Aksan A, Sugimachi K, Toner M. 3-O-methyl-D-glucose improves desiccation tolerance of keratinocytes. ACTA ACUST UNITED AC 2006; 12:1873-9. [PMID: 16889517 DOI: 10.1089/ten.2006.12.1873] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Transplantation of autologous skin grafts and tissue engineered skin replacements for the treatment of burns, trauma, and ulcerative wounds has been shown to restore a protective barrier to infection and fluid loss, reduce heat loss, provide mechanical strength, diminish pain, and dampen the hypermetabolic stress response to thermal injury. Patencies of these grafts depend mainly on the high viability and sustained function of the enmeshed keratinocytes. With growing demand in tissue replacement therapies, development of successful and economical preservation techniques for skin grafts and replacements becomes essential. In this regard, if attained, desiccated state storage offers an economical solution to availability, storage, and transportation problems. Recent studies indicate that carbohydrates are very efficient in stabilizing mammalian cells against various types of stresses, including those associated with cryopreservation and desiccation. In this study we introduce the use of 3-O-methyl-D-glucose (3-OMG), a nonmetabolizable glucose derivative, as a new means of providing protection for keratinocytes undergoing desiccation. We show that with decreasing water contents, viability of the cells decreases; however, at the same water content the immediate post-rehydration viability and long-term survival of the cells exposed to 3-OMG are much higher than those of controls.
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Affiliation(s)
- Marlaina M Norris
- Surgical Services and Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, and Shriners Hospital for Children, Boston, Massachusetts 02114, USA
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30
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Kohli V, Acker JP, Elezzabi AY. Reversible permeabilization using high-intensity femtosecond laser pulses: applications to biopreservation. Biotechnol Bioeng 2006; 92:889-99. [PMID: 16189821 DOI: 10.1002/bit.20689] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Non-invasive manipulation of live cells is important for cell-based therapeutics. Herein we report on the uniqueness of using high-intensity femtosecond laser pulses for reversibly permeabilizing mammalian cells for biopreservation applications. When mammalian cells were suspended in a impermeable hyperosmotic cryoprotectant sucrose solution, femtosecond laser pulses were used to transiently permeabilize cells for cytoplasmic solute uptake. The kinetics of cells exposed to 0.2, 0.3, 0.4, and 0.5 M sucrose, following permeabilization, were measured using video microscopy, and post-permeabilization survival was determined by a dual fluorescence membrane integrity assay. Using appropriate laser parameters, we observed the highest cell survival for 0.2 M sucrose solution (>90%), with a progressive decline in cell survival towards higher concentrations. Using diffusion equations describing the transport of solutes, the intracellular osmolarity at the inner surface of the membrane (x = 10 nm) and to a diffusive length of x = 10 microm was estimated, and a high loading efficiency (>98% for x = 10 nm and >70% for x = 10 microm) was calculated for cells suspended in 0.2 M sucrose. This is the first report of using femtosecond laser pulses for permeabilizing cells in the presence of cryoprotectants for biopreservation applications.
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Affiliation(s)
- Vikram Kohli
- Ultrafast Photonics and Nano-Optics Laboratory, Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta, Canada
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31
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Elliott GD, Liu XH, Cusick JL, Menze M, Vincent J, Witt T, Hand S, Toner M. Trehalose uptake through P2X7 purinergic channels provides dehydration protection. Cryobiology 2005; 52:114-27. [PMID: 16338230 DOI: 10.1016/j.cryobiol.2005.10.009] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2005] [Revised: 10/17/2005] [Accepted: 10/19/2005] [Indexed: 11/25/2022]
Abstract
The tetra-anionic form of ATP (ATP4-) is known to induce monovalent and divalent ion fluxes in cells that express purinergic P2X7 receptors and with sustained application of ATP it has been shown that dyes as large as 831 Da can permeate the cell membrane. The current study explores the kinetics of loading alpha,alpha-trehalose (342 Da) into ATP stimulated J774.A1 cells, which are known to express the purinergic P2X7 receptor. Cells that were incubated at 37 degrees C in a 50 mM phosphate buffer (pH 7.0) containing 225 mM trehalose and 5 mM ATP, were shown to load trehalose linearly over time. Concentrations of approximately 50 mM were reached within 90 min of incubation. Cells incubated in the same solution at 4 degrees C loaded minimally, consistent with the inactivity of the receptor at low temperatures. However, extended incubation at 37 degrees C (>60 min) resulted in zero next-day survival, with adverse effects appearing even with incubation periods as short as 30 min. By using a two-step protocol with a short time period at 37 degrees C to allow pore formation, followed by an extended loading period on ice, cells could be loaded with up to 50 mM trehalose while maintaining good next day recovery (49 +/- 12% by Trypan blue exclusion, 56 +/- 20% by alamarBlue assay). Cells porated by this method and allowed an overnight recovery period exhibited improved dehydration tolerance suggesting a role for ATP poration in the anhydrous preservation of cells.
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Affiliation(s)
- Gloria D Elliott
- Department of Mechanical Engineering and Engineering Sciences, University of North Carolina at Charlotte, 9201 University City Building, Charlotte, NC 28223-0001, USA.
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Buchanan SS, Menze MA, Hand SC, Pyatt DW, Carpenter JF. Cryopreservation of Human Hematopoietic Stem and Progenitor Cells Loaded with Trehalose: Transient Permeabilization via the Adenosine Triphosphate-Dependent P2Z Receptor Channel. ACTA ACUST UNITED AC 2005. [DOI: 10.1089/cpt.2005.3.212] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Sandhya S. Buchanan
- Center for Pharmaceutical Biotechnology and Department of Pharmaceutical Sciences, University of Colorado at Denver and Health Sciences Center, Denver, Colorado
| | - Michael A. Menze
- Division of Cellular, Developmental and Integrative Biology, Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana
| | - Steven C. Hand
- Division of Cellular, Developmental and Integrative Biology, Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana
| | | | - John F. Carpenter
- Center for Pharmaceutical Biotechnology and Department of Pharmaceutical Sciences, University of Colorado at Denver and Health Sciences Center, Denver, Colorado
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33
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Aksimentiev A, Schulten K. Imaging alpha-hemolysin with molecular dynamics: ionic conductance, osmotic permeability, and the electrostatic potential map. Biophys J 2005; 88:3745-61. [PMID: 15764651 PMCID: PMC1305609 DOI: 10.1529/biophysj.104.058727] [Citation(s) in RCA: 477] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2004] [Accepted: 02/08/2005] [Indexed: 01/28/2023] Open
Abstract
alpha-Hemolysin of Staphylococcus aureus is a self-assembling toxin that forms a water-filled transmembrane channel upon oligomerization in a lipid membrane. Apart from being one of the best-studied toxins of bacterial origin, alpha-hemolysin is the principal component in several biotechnological applications, including systems for controlled delivery of small solutes across lipid membranes, stochastic sensors for small solutes, and an alternative to conventional technology for DNA sequencing. Through large-scale molecular dynamics simulations, we studied the permeability of the alpha-hemolysin/lipid bilayer complex for water and ions. The studied system, composed of approximately 300,000 atoms, included one copy of the protein, a patch of a DPPC lipid bilayer, and a 1 M water solution of KCl. Monitoring the fluctuations of the pore structure revealed an asymmetric, on average, cross section of the alpha-hemolysin stem. Applying external electrostatic fields produced a transmembrane ionic current; repeating simulations at several voltage biases yielded a current/voltage curve of alpha-hemolysin and a set of electrostatic potential maps. The selectivity of alpha-hemolysin to Cl(-) was found to depend on the direction and the magnitude of the applied voltage bias. The results of our simulations are in excellent quantitative agreement with available experimental data. Analyzing trajectories of all water molecule, we computed the alpha-hemolysin's osmotic permeability for water as well as its electroosmotic effect, and characterized the permeability of its seven side channels. The side channels were found to connect seven His-144 residues surrounding the stem of the protein to the bulk solution; the protonation of these residues was observed to affect the ion conductance, suggesting the seven His-144 to comprise the pH sensor that gates conductance of the alpha-hemolysin channel.
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Affiliation(s)
- Aleksij Aksimentiev
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 61801, USA
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Abstract
Significant progress has been made in membrane protein engineering over the last 5 years, based largely on the re-design of existing scaffolds. Engineering techniques that have been employed include direct genetic engineering, both covalent and non-covalent modification, unnatural amino acid mutagenesis and total synthesis aided by chemical ligation of unprotected fragments. Combinatorial mutagenesis and directed evolution remain, by contrast, underemployed. Techniques for assembling and purifying heteromeric multisubunit pores have been improved. Progress in the de novo design of channels and pores has been slower. But, we are at the beginning of a new era in membrane protein engineering based on the accelerating acquisition of structural information, a better understanding of molecular motion in membrane proteins, technical improvements in membrane protein refolding and the application of computational approaches developed for soluble proteins. In addition, the next 5 years should see further advances in the applications of engineered channels and pores, notably in therapeutics and sensor technology.
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Affiliation(s)
- Hagan Bayley
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK.
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35
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36
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Buchanan SS, Gross SA, Acker JP, Toner M, Carpenter JF, Pyatt DW. Cryopreservation of Stem Cells Using Trehalose: Evaluation of the Method Using a Human Hematopoietic Cell Line. Stem Cells Dev 2004; 13:295-305. [PMID: 15186725 DOI: 10.1089/154732804323099226] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
While stem cell cryopreservation methods have been optimized using dimethylsulfoxide (DMSO), the established techniques are not optimal when applied to unfertilized human embryonic cells. In addition, important questions remain regarding the toxicity and characteristics of DMSO for treatment of stem cells for clinical use. The objective of this study was to establish an optimal method for cryopreservation of stem cells using low concentrations (0.2 M) of trehalose, a nontoxic disaccharide of glucose, which possesses excellent protective characteristics, in place of current methods utilizing high concentrations (1-2 M) of DMSO. A human hematopoietic cell line was used in this investigation as a surrogate for human stem cells. Trehalose was loaded into cells using a genetically engineered mutant of the pore-forming protein alpha-hemolysin from Staphylococcus aureus. This method results in a nonselective pore equipped with a metal-actuated switch that is sensitive to extracellular zinc concentrations, thus permitting controlled loading of trehalose. Preliminary experiments characterized the effects of poration on TF-1 cells and established optimal conditions for trehalose loading and cell survival. TF-1 cells were frozen at 1 degrees C/min to -80 degrees C with and without intra- and extracellular trehalose. Following storage at -80 degrees C for 1 week, cells were thawed and evaluated for viability, differentiation capacity, and clonogenic activity in comparison to cells frozen with DMSO. Predictably, cells frozen without any protective agent did not survive freezing. Colony-forming units (CFU) generated from cells frozen with intra- and extracellular trehalose, however, were comparable in size, morphology, and number to those generated by cells frozen in DMSO. There was no observable alteration in phenotypic markers of differentiation in either trehalose- or DMSO-treated cells. These data demonstrate that low concentrations of trehalose can protect hematopoietic progenitors from freezing injury and support the concept that trehalose may be useful for freezing embryonic stem cells and other primitive stem cells for therapeutic and investigational use.
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Affiliation(s)
- Sandhya S Buchanan
- Center for Pharmaceutical Biotechnology and Department of Pharmaceutical Sciences, School of Pharmacy, University of Colorado Health Sciences Center, Denver, CO 80262, USA
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37
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Jiang X, Chen H, Yang W, Liu Y, Liu W, Wei J, Tu H, Xie X, Wang L, Xu A. Functional expression and characterization of an acidic actinoporin from sea anemone Sagartia rosea. Biochem Biophys Res Commun 2004; 312:562-70. [PMID: 14680802 DOI: 10.1016/j.bbrc.2003.10.159] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2003] [Indexed: 11/24/2022]
Abstract
Src I is the first reported acidic actinoporin from sea anemone Sagartia rosea with a pI value of 4.8 and comprises 13.9% alpha-helix, 65.1% beta-sheet, and 18.2% random coil. For structure-function studies, Src I was expressed in Escherichia coli as a cleavable fusion protein. Recombinant Src I exhibited obviously hemolytic activity, but the fusion protein Trx-Src I almost lost its hemolytic activity, suggesting the importance of the N-terminal amphiphilic alpha-helix for its functional activity. The cytotoxic effects of Src I depending on the toxin concentration and incubation time were also observed on cultured cells. Among five cell lines: NIH/3T3, U251, NSCLC, BEL-7402, and BGC-823, NSCLC was the most sensitive cells with ID(50) 2.8 microg/ml and BGC-823 was the least sensitive cells with ID(50) 7.4 microg/ml. After incubated with lipid SUVs, such as SM-SUVs and SM/PC-SUVs, the hemolytic activity of Src I was inhibited to some extent. When incubated with calcein-entrapped lipid LUVs, such as SM-LUVs, SM/PC-LUVs, and SM/PG-LUVs, Src I induced release of entrapped calcein. According to the interaction with lipid vesicles, we proposed that it was the membrane matrix made up of phospholipids, not a particular phospholipid that facilitates Src I to react properly.
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Affiliation(s)
- Xiaoyu Jiang
- The Open Laboratory for Marine Functional Genomics of National High-Tech Development, Department of Biochemistry, College of Life Sciences, Sun Yat-sen (Zhongshan) University, Guangzhou 510275, People's Republic of China
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38
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Acker JP, Lu XM, Young V, Cheley S, Bayley H, Fowler A, Toner M. Measurement of trehalose loading of mammalian cells porated with a metal-actuated switchable pore. Biotechnol Bioeng 2003; 82:525-32. [PMID: 12652476 DOI: 10.1002/bit.10599] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Efforts to improve the tolerance of mammalian cells to desiccation have focused on the role that sugars have in protecting cells from lethal injury. Among the key determinants of desiccation tolerance is the intracellular trehalose concentration, and thus quantifying the amount and rate of trehalose accumulation has now become very critical to the success of these desiccation approaches. We introduced trehalose into 3T3 fibroblasts, human keratinocytes, and rat hepatocytes using a genetically engineered mutant of the pore-forming alpha-hemolysin from Staphylococcus aureus. Manipulating the extracellular Zn(2+) concentration selectively opens and closes this pore ( approximately 2 nm) and enables controlled loading of cells with sugars. We quantified intracellular trehalose using gas chromatography-mass spectroscopy (GC-MS) to examine the trimethylsilyl derivative of intracellular trehalose. Using the GC-MS method, we demonstrate that the switchable characteristics of H5 alpha-hemolysin permit controlled loading of the high concentrations of trehalose (up to 0.5 M) necessary for engineering desiccation tolerance in mammalian cells.
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Affiliation(s)
- Jason P Acker
- The Center for Engineering in Medicine and Surgical Services, Massachusetts General Hospital, Harvard Medical School, and Shriners Hospitals for Children, 51 Blossom Street, Room 266, Boston, Massachusetts 02114, USA
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39
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Eroglu A, Lawitts JA, Toner M, Toth TL. Quantitative microinjection of trehalose into mouse oocytes and zygotes, and its effect on development. Cryobiology 2003; 46:121-34. [PMID: 12686202 DOI: 10.1016/s0011-2240(03)00018-x] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Sugars such as trehalose are effectively used by various organisms as protective agents to undergo anhydrobiosis and cryobiosis. The objective of this study was first to establish a method for quantitative delivery of trehalose as a model sugar into oocytes, and then to evaluate its effect on development of mouse zygotes. To this end, a quantitative microinjection technique was developed using volumetric response of microdroplets suspended in dimethylpolysilaxene. To verify accuracy of this technique, both microdroplets and oocytes were microinjected with fluorophore-labeled dextran. Thereafter, injection volumes were calculated from fluorescence intensity, and volumetric responses of both microdroplets and oocytes. Comparison of calculated injection volumes revealed that this technique reflects microinjection into oocytes with pL-accuracy. The next series of experiments focused on toxicity of injection buffers (i.e., 10mM Tris and 15mM Hepes) and trehalose. Microinjection of Hepes and Tris buffer in the presence of 0.1M trehalose resulted in blastocyst rates of 86 and 72%, respectively, without a significant difference when compared to controls (86%). In subsequent experiments, Hepes was used as the injection buffer, and embryonic development of zygotes was studied as a function of intracellular trehalose concentrations. Microinjection of trehalose up to 0.15M resulted in development to blastocyst stage similar to controls (85 and 87%, respectively) while the blastocyst rate was significantly decreased (43%) in the presence of 0.20M intracellular trehalose. When transferred to foster mothers, trehalose-injected zygotes (0.1M) implanted and developed to day 16 fetuses similar to controls, healthy pups were born. The findings of this study suggest that trehalose at effective intracellular concentrations does not impair development of mouse zygotes.
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Affiliation(s)
- Ali Eroglu
- Center for Engineering in Medicine and Surgical Services, Massachusetts General Hospital and Harvard Medical School, Shriners Burns Hospital, 51 Blossom Street, Boston, MA 02114, USA
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40
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Mally M, Majhenc J, Svetina S, Zeks B. Mechanisms of equinatoxin II-induced transport through the membrane of a giant phospholipid vesicle. Biophys J 2002; 83:944-53. [PMID: 12124276 PMCID: PMC1302198 DOI: 10.1016/s0006-3495(02)75220-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Protein equinatoxin II from sea anemone Actinia equina L. was used to form pores in phospholipid membranes. We studied the effect of these pores on the net transmembrane transport of sucrose and glucose by observing single giant (cell-size) vesicles under the phase contrast microscope. Sugar composition in the vesicle was determined by measuring the width of the halo, which appears around the vesicle in the phase contrast image. The transport of sugars was induced when a vesicle, filled with the sucrose solution, was transferred into the isomolar environment of a glucose solution with added equinatoxin II. Typically, a vesicle grew to a critical size, then the membrane broke by bursting and the vesicle shrank, started to grow again, and the whole process was repeated. The consecutive membrane breaks occurred in the same spot. The observed behavior was interpreted by the diffusion flow of the glucose molecules through the equinatoxin II-induced pores and the consequent increase of the vesicle water content. The burst relaxed the critically strained membrane, which then apparently resealed. A mathematical model of the described behavior was developed and was used to obtain the equinatoxin II-induced membrane permeability for the glucose molecules. Its dependence on the equinatoxin II concentration is in agreement with the previous reports.
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Affiliation(s)
- M Mally
- Institute of Biophysics, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia.
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41
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Acker JP, Fowler A, Lauman B, Cheley S, Toner M. Survival of Desiccated Mammalian Cells: Beneficial Effects of Isotonic Media. ACTA ACUST UNITED AC 2002. [DOI: 10.1089/153834402320882638] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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42
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Gu LQ, Cheley S, Bayley H. Prolonged residence time of a noncovalent molecular adapter, beta-cyclodextrin, within the lumen of mutant alpha-hemolysin pores. J Gen Physiol 2001; 118:481-94. [PMID: 11696607 PMCID: PMC2233842 DOI: 10.1085/jgp.118.5.481] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Noncovalent molecular adapters, such as cyclodextrins, act as binding sites for channel blockers when lodged in the lumen of the alpha-hemolysin (alphaHL) pore, thereby offering a basis for the detection of a variety of organic molecules with alphaHL as a sensor element. beta-Cyclodextrin (betaCD) resides in the wild-type alphaHL pore for several hundred microseconds. The residence time can be extended to several milliseconds by the manipulation of pH and transmembrane potential. Here, we describe mutant homoheptameric alphaHL pores that are capable of accommodating betaCD for tens of seconds. The mutants were obtained by site-directed mutagenesis at position 113, which is a residue that lies near a constriction in the lumen of the transmembrane beta barrel, and fall into two classes. Members of the tight-binding class, M113D, M113N, M113V, M113H, M113F and M113Y, bind betaCD approximately 10(4)-fold more avidly than the remaining alphaHL pores, including WT-alphaHL. The lower K(d) values of these mutants are dominated by reduced values of k(off). The major effect of the mutations is most likely a remodeling of the binding site for betaCD in the vicinity of position 113. In addition, there is a smaller voltage-sensitive component of the binding, which is also affected by the residue at 113 and may result from transport of the neutral betaCD molecule by electroosmotic flow. The mutant pores for which the dwell time of betaCD is prolonged can serve as improved components for stochastic sensors.
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Affiliation(s)
- Li-Qun Gu
- Department of Medical Biochemistry and Genetics, The Texas A&M University System Health Science Center, College Station, TX 77843
| | - Stephen Cheley
- Department of Medical Biochemistry and Genetics, The Texas A&M University System Health Science Center, College Station, TX 77843
| | - Hagan Bayley
- Department of Medical Biochemistry and Genetics, The Texas A&M University System Health Science Center, College Station, TX 77843
- Department of Chemistry, Texas A&M University, College Station, TX 77843
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43
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Menestrina G, Serra MD, Prévost G. Mode of action of beta-barrel pore-forming toxins of the staphylococcal alpha-hemolysin family. Toxicon 2001; 39:1661-72. [PMID: 11595629 DOI: 10.1016/s0041-0101(01)00153-2] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Staphylococcal alpha-hemolysin is the prototype of a family of bacterial exotoxins with membrane-damaging function, which share sequence and structure homology. These toxins are secreted in a soluble form which finally converts into a transmembrane pore by assembling an oligomeric beta-barrel, with hydrophobic residues facing the lipids and hydrophilic residues facing the lumen of the channel. Besides alpha-hemolysin the family includes other single chain toxins forming homo-oligomers, e.g. beta-toxin of Clostridium perfringens, hemolysin II and cytotoxin K of Bacillus cereus, but also the staphylococcal bi-component toxins, like gamma-hemolysins and leucocidins, which are only active as the combination of two similar proteins which form hetero-oligomers. The molecular basis of membrane insertion has become clearer after the determination of the crystal structure of both the oligomeric pore and the soluble monomer. Studies on this family of beta-barrel pore-forming toxins are important for many aspects: (i) they are involved in serious pathologies of humans and farmed animals, (ii) they are a good model system to investigate protein-membrane interaction and (iii) they are the basic elements for the construction of nanopores with biotechnological applications in various fields.
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Affiliation(s)
- G Menestrina
- CNR-ITC Centro Fisica Stati Aggregati, Via Sommarive 18, I-38050 Povo, Trento, Italy.
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44
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Lu Y, Berry SM, Pfister TD. Engineering novel metalloproteins: design of metal-binding sites into native protein scaffolds. Chem Rev 2001; 101:3047-80. [PMID: 11710062 DOI: 10.1021/cr0000574] [Citation(s) in RCA: 280] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Y Lu
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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45
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Chen T, Acker JP, Eroglu A, Cheley S, Bayley H, Fowler A, Toner M. Beneficial effect of intracellular trehalose on the membrane integrity of dried mammalian cells. Cryobiology 2001; 43:168-81. [PMID: 11846471 DOI: 10.1006/cryo.2001.2360] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recently, there has been much interest in using trehalose and other small carbohydrates to preserve mammalian cells in the dried state as an alternative to cryopreservation. Here, we report on the successful preservation of plasma membrane integrity after drying, as a first step toward full preservation of mammalian cells. Trehalose was introduced into cells using a genetically engineered version of alpha-hemolysin, a pore-forming protein; the cells were then dried and stored for weeks at different temperatures with approximately 90% recovery of the intact plasma membrane. We show that protection of the plasma membrane by internal trehalose is dose dependent and estimate the amount of internal trehalose required for adequate protection to be approximately 10(10) molecules/cell. In addition, a minimal amount of water (approximately 15 wt%) appears to be necessary. These results show that a key component of mammalian cells can be preserved in a dried state for weeks under mild conditions (-20 degrees C and 5% relative humidity) and thereby suggest new approaches to preserving mammalian cells.
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Affiliation(s)
- T Chen
- The Center for Engineering in Medicine and Surgical Services, Boston, MA 02114, U.S.A
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46
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Valcarcel CA, Dalla Serra M, Potrich C, Bernhart I, Tejuca M, Martinez D, Pazos F, Lanio ME, Menestrina G. Effects of lipid composition on membrane permeabilization by sticholysin I and II, two cytolysins of the sea anemone Stichodactyla helianthus. Biophys J 2001; 80:2761-74. [PMID: 11371451 PMCID: PMC1301462 DOI: 10.1016/s0006-3495(01)76244-3] [Citation(s) in RCA: 148] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Sticholysin I and II (St I and St II), two basic cytolysins purified from the Caribbean sea anemone Stichodactyla helianthus, efficiently permeabilize lipid vesicles by forming pores in their membranes. A general characteristic of these toxins is their preference for membranes containing sphingomyelin (SM). As a consequence, vesicles formed by equimolar mixtures of SM with phosphatidylcholine (PC) are very good targets for St I and II. To better characterize the lipid dependence of the cytolysin-membrane interaction, we have now evaluated the effect of including different lipids in the composition of the vesicles. We observed that at low doses of either St I or St II vesicles composed of SM and phosphatidic acid (PA) were permeabilized faster and to a higher extent than vesicles of PC and SM. As in the case of PC/SM mixtures, permeabilization was optimal when the molar ratio of PA/SM was ~1. The preference for membranes containing PA was confirmed by inhibition experiments in which the hemolytic activity of St I was diminished by pre-incubation with vesicles of different composition. The inclusion of even small proportions of PA into PC/SM LUVs led to a marked increase in calcein release caused by both St I and St II, reaching maximal effect at ~5 mol % of PA. Inclusion of other negatively charged lipids (phosphatidylserine (PS), phosphatidylglycerol (PG), phosphatidylinositol (PI), or cardiolipin (CL)), all at 5 mol %, also elicited an increase in calcein release, the potency being in the order CL approximately PA >> PG approximately PI approximately PS. However, some boosting effect was also obtained, including the zwitterionic lipid phosphatidylethanolamine (PE) or even, albeit to a lesser extent, the positively charged lipid stearylamine (SA). This indicated that the effect was not mediated by electrostatic interactions between the cytolysin and the negative surface of the vesicles. In fact, increasing the ionic strength of the medium had only a small inhibitory effect on the interaction, but this was actually larger with uncharged vesicles than with negatively charged vesicles. A study of the fluidity of the different vesicles, probed by the environment-sensitive fluorescent dye diphenylhexatriene (DPH), showed that toxin activity was also not correlated to the average membrane fluidity. It is suggested that the insertion of the toxin channel could imply the formation in the bilayer of a nonlamellar structure, a toroidal lipid pore. In this case, the presence of lipids favoring a nonlamellar phase, in particular PA and CL, strong inducers of negative curvature in the bilayer, could help in the formation of the pore. This possibility is confirmed by the fact that the formation of toxin pores strongly promotes the rate of transbilayer movement of lipid molecules, which indicates local disruption of the lamellar structure.
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Affiliation(s)
- C A Valcarcel
- CNR-ITC, Centro di Fisica degli Stati Aggregati, I-38050 Povo, Italy
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47
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Affiliation(s)
- G Prévost
- Institut de Bactériologie de la Faculté de Médecine, Université Louis Pasteur-Hôpitaux Universitaires de Strasbourg, 3, rue Koeberlé, 67000 Strasbourg, France
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48
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Valeva A, Schnabel R, Walev I, Boukhallouk F, Bhakdi S, Palmer M. Membrane insertion of the heptameric staphylococcal alpha-toxin pore. A domino-like structural transition that is allosterically modulated by the target cell membrane. J Biol Chem 2001; 276:14835-41. [PMID: 11279048 DOI: 10.1074/jbc.m100301200] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Staphylococcal alpha-toxin forms heptameric pores on eukaryotic cells. After binding to the cell membrane in its monomeric form, the toxin first assembles into a heptameric pre-pore. Subsequently, the pre-pore transforms into the final pore by membrane insertion of an amphipathic beta-barrel, which comprises the "central loop" domains of all heptamer subunits. The process of membrane insertion was analyzed here using a set of functionally altered toxin mutants. The results show that insertion may be initiated within an individual protomer when its NH2 terminus activates its central loop. The activated state is then shared with the central loops of the residual heptamer subunits, which results in cooperative membrane penetration. This cooperation of the central loops commences while these are still remote from the lipid bilayer. Nevertheless, it is subject to modulation by the target membrane, which therefore acts across a distance much like an allosteric effector. However, while allosteric transitions usually are reversible, membrane insertion of alpha-toxin is an irreversible event, and we show here that it can proceed to completion in a domino-like fashion when triggered by as little as a single foreign atom within the entire heptamer.
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Affiliation(s)
- A Valeva
- Institute of Medical Microbiology and Hygiene, University of Mainz, Obere Zahlbacher Strasse 67, D55101 Mainz, Germany.
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49
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Movileanu L, Howorka S, Braha O, Bayley H. Detecting protein analytes that modulate transmembrane movement of a polymer chain within a single protein pore. Nat Biotechnol 2000; 18:1091-5. [PMID: 11017049 DOI: 10.1038/80295] [Citation(s) in RCA: 251] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Here we describe a new type of biosensor element for detecting proteins in solution at nanomolar concentrations. We tethered a 3.4 kDa polyethylene glycol chain at a defined site within the lumen of the transmembrane protein pore formed by staphylococcal alpha-hemolysin. The free end of the polymer was covalently attached to a biotin molecule. On incorporation of the modified pore into a lipid bilayer, the biotinyl group moves from one side of the membrane to the other, and is detected by reversible capture with a mutant streptavidin. The capture events are observed as changes in ionic current passing through single pores in planar bilayers. Accordingly, the modified pore allows detection of a protein analyte at the single-molecule level, facilitating both quantification and identification through a distinctive current signature. The approach has higher time resolution compared with other kinetic measurements, such as those obtained by surface plasmon resonance.
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Affiliation(s)
- L Movileanu
- Department of Medical Biochemistry and Genetics, The Texas A&M University System Health Science Center, College Station, TX 77843-1114, USA
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50
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Valeva A, Walev I, Gerber A, Klein J, Palmer M, Bhakdi S. Staphylococcal alpha-toxin: repair of a calcium-impermeable pore in the target cell membrane. Mol Microbiol 2000; 36:467-76. [PMID: 10792732 DOI: 10.1046/j.1365-2958.2000.01865.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Staphylococcal alpha-toxin forms heptameric pores that render membranes permeable for monovalent cations. The pore is formed by an amphipathic beta-barrel encompassing amino acid residues 118-140 of each subunit of the oligomer. Human fibroblasts are susceptible to alpha-toxin but are able to repair the membrane lesions. Thereby, toxin oligomers remain embedded in the plasma membrane and exposed to the extracellular medium. In this study, we sought to detect structural changes occurring in the pore-forming sequence during lesion repair. Single cysteine substitution mutants were labelled with the environmentally sensitive fluorochrome acrylodan and, after mixing with wild-type toxin, incorporated into hybrid heptamers on fibroblast membranes. Formation of the lipid-inserted beta-barrel was accompanied by characteristic fluorescence emission shifts. After lesion repair, the environment of the residues at the outer surface of the beta-barrel remained unchanged, indicating continued contact with lipids. However, the labelled residues oriented towards the channel lumen underwent a green to blue shift in fluorescence, indicating reduced exposure to water. Pore closure proceeded in the presence of calmodulin inhibitors and of microtubule disruptors; however, it was prevented by cytochalasin D and by inhibitors of lipid metabolism. Our findings reveal the existence of a novel mechanism of membrane repair that may consist in constriction of the inserted proteinaceous pore within the lipid bilayer.
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Affiliation(s)
- A Valeva
- Institutes of Medical Microbiology and Hygiene, and Pharmacology, University of Mainz, Hochhaus am Augustusplatz, D-55101 Mainz, Germany.
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