1
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Khunpetch P, Majee A, Podgornik R. Curvature effects in charge-regulated lipid bilayers. SOFT MATTER 2022; 18:2597-2610. [PMID: 35294512 DOI: 10.1039/d1sm01665b] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
We formulate a theory of electrostatic interactions in lipid bilayer membranes where both monolayer leaflets contain dissociable moieties that are subject to charge regulation. We specifically investigate the coupling between membrane curvature and charge regulation of a lipid bilayer vesicle using both the linear Debye-Hückel (DH) and the non-linear Poisson-Boltzmann (PB) theory. We find that charge regulation of an otherwise symmetric bilayer membrane can induce charge symmetry breaking, non-linear flexoelectricity and anomalous curvature dependence of free energy. The pH effects investigated go beyond the paradigm of electrostatic renormalization of the mechano-elastic properties of membranes.
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Affiliation(s)
- Petch Khunpetch
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China.
| | - Arghya Majee
- Max Planck Institute for Intelligent Systems, Stuttgart, Germany
- IV. Institute for Theoretical Physics, University of Stuttgart, Stuttgart, Germany.
| | - Rudolf Podgornik
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China.
- Kavli Institute for Theoretical Sciences, University of Chinese Academy of Sciences, Beijing, China
- CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.
- Wenzhou Institute of the University of Chinese Academy of Sciences, Wenzhou, Zhejiang, China
- Department of Theoretical Physics, Jožef Stefan Institute, Ljubljana, Slovenia
- Department of Physics, Faculty of Mathematics and Physics, University of Ljubljana, Ljubljana, Slovenia
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2
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Ritter M, Bresgen N, Kerschbaum HH. From Pinocytosis to Methuosis-Fluid Consumption as a Risk Factor for Cell Death. Front Cell Dev Biol 2021; 9:651982. [PMID: 34249909 PMCID: PMC8261248 DOI: 10.3389/fcell.2021.651982] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 04/29/2021] [Indexed: 12/11/2022] Open
Abstract
The volumes of a cell [cell volume (CV)] and its organelles are adjusted by osmoregulatory processes. During pinocytosis, extracellular fluid volume equivalent to its CV is incorporated within an hour and membrane area equivalent to the cell's surface within 30 min. Since neither fluid uptake nor membrane consumption leads to swelling or shrinkage, cells must be equipped with potent volume regulatory mechanisms. Normally, cells respond to outwardly or inwardly directed osmotic gradients by a volume decrease and increase, respectively, i.e., they shrink or swell but then try to recover their CV. However, when a cell death (CD) pathway is triggered, CV persistently decreases in isotonic conditions in apoptosis and it increases in necrosis. One type of CD associated with cell swelling is due to a dysfunctional pinocytosis. Methuosis, a non-apoptotic CD phenotype, occurs when cells accumulate too much fluid by macropinocytosis. In contrast to functional pinocytosis, in methuosis, macropinosomes neither recycle nor fuse with lysosomes but with each other to form giant vacuoles, which finally cause rupture of the plasma membrane (PM). Understanding methuosis longs for the understanding of the ionic mechanisms of cell volume regulation (CVR) and vesicular volume regulation (VVR). In nascent macropinosomes, ion channels and transporters are derived from the PM. Along trafficking from the PM to the perinuclear area, the equipment of channels and transporters of the vesicle membrane changes by retrieval, addition, and recycling from and back to the PM, causing profound changes in vesicular ion concentrations, acidification, and-most importantly-shrinkage of the macropinosome, which is indispensable for its proper targeting and cargo processing. In this review, we discuss ion and water transport mechanisms with respect to CVR and VVR and with special emphasis on pinocytosis and methuosis. We describe various aspects of the complex mutual interplay between extracellular and intracellular ions and ion gradients, the PM and vesicular membrane, phosphoinositides, monomeric G proteins and their targets, as well as the submembranous cytoskeleton. Our aim is to highlight important cellular mechanisms, components, and processes that may lead to methuotic CD upon their derangement.
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Affiliation(s)
- Markus Ritter
- Center for Physiology, Pathophysiology and Biophysics, Institute for Physiology and Pathophysiology, Paracelsus Medical University, Salzburg, Austria
- Institute for Physiology and Pathophysiology, Paracelsus Medical University, Nuremberg, Germany
- Gastein Research Institute, Paracelsus Medical University, Salzburg, Austria
- Ludwig Boltzmann Institute for Arthritis und Rehabilitation, Salzburg, Austria
- Kathmandu University School of Medical Sciences, Dhulikhel, Nepal
| | - Nikolaus Bresgen
- Department of Biosciences, University of Salzburg, Salzburg, Austria
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3
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Potočnik T, Miklavčič D, Maček Lebar A. Effect of electroporation and recovery medium pH on cell membrane permeabilization, cell survival and gene transfer efficiency in vitro. Bioelectrochemistry 2019; 130:107342. [DOI: 10.1016/j.bioelechem.2019.107342] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 07/31/2019] [Accepted: 07/31/2019] [Indexed: 12/12/2022]
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4
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Electric field-responsive nanoparticles and electric fields: physical, chemical, biological mechanisms and therapeutic prospects. Adv Drug Deliv Rev 2019; 138:56-67. [PMID: 30414494 DOI: 10.1016/j.addr.2018.10.017] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 10/05/2018] [Accepted: 10/31/2018] [Indexed: 12/18/2022]
Abstract
Electric fields are among physical stimuli that have revolutionized therapy. Occurring endogenously or exogenously, the electric field can be used as a trigger for controlled drug release from electroresponsive drug delivery systems, can stimulate wound healing and cell proliferation, may enhance endocytosis or guide stem cell differentiation. Electric field pulses may be applied to induce cell fusion, can increase the penetration of therapeutic agents into cells, or can be applied as a standalone therapy to ablate tumors. This review describes the main therapeutic trends and overviews the main physical, chemical and biological mechanisms underlying the actions of electric fields. Overall, the electric field can be used in therapeutic approaches in several ways. The electric field can act on drug carriers, cells and tissues. Understanding the multiple effects of this powerful tool will help harnessing its full therapeutic potential in an efficient and safe way.
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5
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Taneva E, Sinclair S, Mesquita PM, Weinrick B, Cameron SA, Cheshenko N, Reagle K, Frank B, Srinivasan S, Fredricks D, Keller MJ, Herold BC. Vaginal microbiome modulates topical antiretroviral drug pharmacokinetics. JCI Insight 2018; 3:99545. [PMID: 29997295 PMCID: PMC6124523 DOI: 10.1172/jci.insight.99545] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 05/31/2018] [Indexed: 01/04/2023] Open
Abstract
Tenofovir gel and dapivirine ring provided variable HIV protection in clinical trials, reflecting poor adherence and possibly biological factors. We hypothesized that vaginal microbiota modulates pharmacokinetics and tested the effects of pH, individual bacteria, and vaginal swabs from women on pharmacokinetics and antiviral activity. Tenofovir, but not dapivirine, uptake by human cells was reduced as pH increased. Lactobacillus crispatus actively transported tenofovir leading to a loss in drug bioavailability and culture supernatants from Gardnerella vaginalis, but not Atopobium vaginae, blocked tenofovir endocytosis. The inhibition of endocytosis mapped to adenine. Adenine increased from 65.5 μM in broth to 246 μM in Gardnerella, but decreased to 9.5 μM in Atopobium supernatants. This translated into a decrease in anti-HIV activity when Gardnerella supernatants or adenine were added to cultures. Dapivirine was also impacted by microbiota, as drug bound irreversibly to bacteria, resulting in decreased antiviral activity. When drugs were incubated with vaginal swabs, 30.7% ± 5.7% of dapivirine and 63.9% ± 8.8% of tenofovir were recovered in supernatants after centrifugation of the bacterial cell pellet. In contrast, no impact of microbiota on the pharmacokinetics of the prodrugs, tenofovir disoproxil fumarate or tenofovir alafenamide, was observed. Together, these results demonstrate that microbiota may impact pharmacokinetics and contribute to inconsistent efficacy.
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Affiliation(s)
| | | | | | | | - Scott A. Cameron
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, USA
| | | | - Kerry Reagle
- Particle Sciences, Inc., Bethlehem, Pennsylvania, USA
| | - Bruce Frank
- Particle Sciences, Inc., Bethlehem, Pennsylvania, USA
| | - Sujatha Srinivasan
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, University of Washington, Seattle, Washington, USA
| | - David Fredricks
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, University of Washington, Seattle, Washington, USA
| | - Marla J. Keller
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Betsy C. Herold
- Department of Microbiology & Immunology
- Department of Pediatrics, and
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6
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Angelova MI, Bitbol AF, Seigneuret M, Staneva G, Kodama A, Sakuma Y, Kawakatsu T, Imai M, Puff N. pH sensing by lipids in membranes: The fundamentals of pH-driven migration, polarization and deformations of lipid bilayer assemblies. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:2042-2063. [PMID: 29501601 DOI: 10.1016/j.bbamem.2018.02.026] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 02/22/2018] [Accepted: 02/24/2018] [Indexed: 01/27/2023]
Abstract
Most biological molecules contain acido-basic groups that modulate their structure and interactions. A consequence is that pH gradients, local heterogeneities and dynamic variations are used by cells and organisms to drive or regulate specific biological functions including energetic metabolism, vesicular traffic, migration and spatial patterning of tissues in development. While the direct or regulatory role of pH in protein function is well documented, the role of hydrogen and hydroxyl ions in modulating the properties of lipid assemblies such as bilayer membranes is only beginning to be understood. Here, we review approaches using artificial lipid vesicles that have been instrumental in providing an understanding of the influence of pH gradients and local variations on membrane vectorial motional processes: migration, membrane curvature effects promoting global or local deformations, crowding generation by segregative polarization processes. In the case of pH induced local deformations, an extensive theoretical framework is given and an application to a specific biological issue, namely the structure and stability of mitochondrial cristae, is described. This article is part of a Special Issue entitled: Emergence of Complex Behavior in Biomembranes edited by Marjorie Longo.
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Affiliation(s)
- Miglena I Angelova
- Sorbonne University, Faculty of Science and Engineering, UFR 925 Physics, Paris F-75005, France; University Paris Diderot - Paris 7, Sorbonne Paris Cité, Laboratory Matière et Systèmes Complexes (MSC) UMR 7057 CNRS, Paris F-75013, France.
| | - Anne-Florence Bitbol
- Sorbonne University, Faculty of Science and Engineering, Laboratory Jean Perrin, UMR 8237 CNRS, Paris F-75005, France
| | - Michel Seigneuret
- University Paris Diderot - Paris 7, Sorbonne Paris Cité, Laboratory Matière et Systèmes Complexes (MSC) UMR 7057 CNRS, Paris F-75013, France
| | - Galya Staneva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Atsuji Kodama
- Department of Physics, Tohoku University, Aoba, Sendai 980-8578, Japan
| | - Yuka Sakuma
- Department of Physics, Tohoku University, Aoba, Sendai 980-8578, Japan
| | | | - Masayuki Imai
- Department of Physics, Tohoku University, Aoba, Sendai 980-8578, Japan
| | - Nicolas Puff
- Sorbonne University, Faculty of Science and Engineering, UFR 925 Physics, Paris F-75005, France; University Paris Diderot - Paris 7, Sorbonne Paris Cité, Laboratory Matière et Systèmes Complexes (MSC) UMR 7057 CNRS, Paris F-75013, France
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7
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Pepper JT, Maheshwari P, Eudes F. Adsorption of cell-penetrating peptide Tat2 and polycation luviquat FC-370 to triticale microspore exine. Colloids Surf B Biointerfaces 2017; 157:207-214. [PMID: 28599181 DOI: 10.1016/j.colsurfb.2017.05.075] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 05/16/2017] [Accepted: 05/30/2017] [Indexed: 01/01/2023]
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8
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Xiaoyun X, Chaofei H, Weiqi Z, Chen C, Lixia L, Queping L, Cong P, Shuang Z, Juan S, Xiang C. Possible Involvement of F1F0-ATP synthase and Intracellular ATP in Keratinocyte Differentiation in normal skin and skin lesions. Sci Rep 2017; 7:42672. [PMID: 28209970 PMCID: PMC5314331 DOI: 10.1038/srep42672] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 01/11/2017] [Indexed: 12/15/2022] Open
Abstract
The F1F0-ATP synthase, an enzyme complex, is mainly located on the mitochondrial inner membrane or sometimes cytomembrane to generate or hydrolyze ATP, play a role in cell proliferation. This study focused on the role of F1F0-ATP synthase in keratinocyte differentiation, and its relationship with intracellular and extracellular ATP (InATP and ExATP). The F1F0-ATP synthase β subunit (ATP5B) expression in various skin tissues and confluence-dependent HaCaT differentiation models was detected. ATP5B expression increased with keratinocyte and HaCaT cell differentiation in normal skin, some epidermis hyper-proliferative diseases, squamous cell carcinoma, and the HaCaT cell differentiation model. The impact of InATP and ExATP content on HaCaT differentiation was reflected by the expression of the differentiation marker involucrin. Inhibition of F1F0-ATP synthase blocked HaCaT cell differentiation, which was associated with a decrease of InATP content, but not with changes of ExATP. Our results revealed that F1F0-ATP synthase expression is associated with the process of keratinocyte differentiation which may possibly be related to InATP synthesis.
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Affiliation(s)
- Xie Xiaoyun
- Department of Dermatology, XiangYa Hospital, Central South University, Changsha, China.,Department of Rheumatology and Immunology, XiangYa Hospital, Central South University, Changsha, China
| | - Han Chaofei
- Department of Plastic and Reconstructive Surgery, The Third XiangYa Hospital, Central South University, Changsha, China
| | - Zeng Weiqi
- Department of Dermatology, XiangYa Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Skin Cancer and Psoriasis, XiangYa Hospital, Central South University, Changsha, China
| | - Chen Chen
- Department of Dermatology, XiangYa Hospital, Central South University, Changsha, China.,Department of Nephrology, XiangYa Hospital, Central South University, Changsha, China
| | - Lu Lixia
- Department of Dermatology, XiangYa Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Skin Cancer and Psoriasis, XiangYa Hospital, Central South University, Changsha, China
| | - Liu Queping
- Department of Dermatology, XiangYa Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Skin Cancer and Psoriasis, XiangYa Hospital, Central South University, Changsha, China
| | - Peng Cong
- Department of Dermatology, XiangYa Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Skin Cancer and Psoriasis, XiangYa Hospital, Central South University, Changsha, China
| | - Zhao Shuang
- Department of Dermatology, XiangYa Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Skin Cancer and Psoriasis, XiangYa Hospital, Central South University, Changsha, China
| | - Su Juan
- Department of Dermatology, XiangYa Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Skin Cancer and Psoriasis, XiangYa Hospital, Central South University, Changsha, China
| | - Chen Xiang
- Department of Dermatology, XiangYa Hospital, Central South University, Changsha, China.,Hunan Key Laboratory of Skin Cancer and Psoriasis, XiangYa Hospital, Central South University, Changsha, China
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9
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Qian Z, Martyna A, Hard RL, Wang J, Appiah-Kubi G, Coss C, Phelps MA, Rossman JS, Pei D. Discovery and Mechanism of Highly Efficient Cyclic Cell-Penetrating Peptides. Biochemistry 2016; 55:2601-12. [DOI: 10.1021/acs.biochem.6b00226] [Citation(s) in RCA: 185] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Ziqing Qian
- Department
of Chemistry and Biochemistry, The Ohio State University, 484
West 12th Avenue, Columbus, Ohio 43210, United States
| | - Agnieszka Martyna
- School
of Biosciences, University of Kent, Canterbury, CT2 7NJ, United Kingdom
| | - Ryan L. Hard
- Department
of Chemistry and Biochemistry, The Ohio State University, 484
West 12th Avenue, Columbus, Ohio 43210, United States
| | - Jiang Wang
- Division
of Pharmaceutics, College of Pharmacy, The Ohio State University, Columbus, Ohio 43210, United States
| | - George Appiah-Kubi
- Department
of Chemistry and Biochemistry, The Ohio State University, 484
West 12th Avenue, Columbus, Ohio 43210, United States
| | - Christopher Coss
- Division
of Pharmaceutics, College of Pharmacy, The Ohio State University, Columbus, Ohio 43210, United States
| | - Mitch A. Phelps
- Division
of Pharmaceutics, College of Pharmacy, The Ohio State University, Columbus, Ohio 43210, United States
| | - Jeremy S. Rossman
- School
of Biosciences, University of Kent, Canterbury, CT2 7NJ, United Kingdom
| | - Dehua Pei
- Department
of Chemistry and Biochemistry, The Ohio State University, 484
West 12th Avenue, Columbus, Ohio 43210, United States
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10
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Negrini R, Fong WK, Boyd BJ, Mezzenga R. pH-responsive lyotropic liquid crystals and their potential therapeutic role in cancer treatment. Chem Commun (Camb) 2015; 51:6671-4. [PMID: 25783035 DOI: 10.1039/c4cc10274f] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A weak amphiphilic base, pyridinylmethyl linoleate, is blended with monolinolein, yielding mesophases with a pH-induced hexagonal-to-cubic transition at pH ≤ 5.5. We show the potential therapeutic role of this mesophase in treating cancerous tissues exploiting their more acidic pH compared to healthy tissues. In vitro release studies with doxorubicin on HT29 human colon cancer cells show a 10-fold faster release and 3-fold increased efficiency for killing cancer cells at pH 5.5 versus pH 7.4, demonstrating the potential of this strategy in cancer treatment.
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Affiliation(s)
- Renata Negrini
- Department of Health Sciences & Technology, ETH Zürich, 8092 Zürich, Switzerland.
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11
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Shemi A, Khvalevsky EZ, Gabai RM, Domb A, Barenholz Y. Multistep, effective drug distribution within solid tumors. Oncotarget 2015; 6:39564-77. [PMID: 26416413 PMCID: PMC4741846 DOI: 10.18632/oncotarget.5051] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 09/10/2015] [Indexed: 12/18/2022] Open
Abstract
The distribution of drugs within solid tumors presents a long-standing barrier for efficient cancer therapies. Tumors are highly resistant to diffusion, and the lack of blood and lymphatic flows suppresses convection. Prolonged, continuous intratumoral drug delivery from a miniature drug source offers an alternative to both systemic delivery and intratumoral injection. Presented here is a model of drug distribution from such a source, in a multistep process. At delivery onset the drug mainly affects the closest surroundings. Such 'priming' enables drug penetration to successive cell layers. Tumor 'void volume' (volume not occupied by cells) increases, facilitating lymphatic perfusion. The drug is then transported by hydraulic convection downstream along interstitial fluid pressure (IFP) gradients, away from the tumor core. After a week tumor cell death occurs throughout the entire tumor and IFP gradients are flattened. Then, the drug is transported mainly by 'mixing', powered by physiological bulk body movements. Steady state is achieved and the drug covers the entire tumor over several months. Supporting measurements are provided from the LODER system, releasing siRNA against mutated KRAS over months in pancreatic cancer in-vivo models. LODER was also successfully employed in a recent Phase 1/2 clinical trial with pancreatic cancer patients.
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Affiliation(s)
| | | | | | - Abraham Domb
- Faculty of Medicine - School of Pharmacy, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yechezkel Barenholz
- Membrane and Liposome Research Lab, Hebrew University Hadassah Medical School, Jerusalem, Israel
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12
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Ben-Dov N, Korenstein R. The uptake of HIV Tat peptide proceeds via two pathways which differ from macropinocytosis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1848:869-77. [PMID: 25542781 DOI: 10.1016/j.bbamem.2014.12.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 11/16/2014] [Accepted: 12/16/2014] [Indexed: 12/20/2022]
Abstract
Cell penetrating peptides (CPPs) have been extensively studied as vectors for cellular delivery of therapeutic molecules, yet the identity of their uptake routes remained unclear and is still under debate. In this study we provide new insights into CPP entry routes by quantitatively measuring the intracellular uptake of FAM-labeled Tat-peptide under rigorous kinetic and thermal conditions. The uptake of Tat-peptide between 4 and 15°C corresponds to Q10=1.1, proceeding through a prompt (<5 min), temperature-independent process, suggesting direct membrane translocation. At longer durations, Tat rate of uptake shows linear dependence on temperature with Q10=1.44, accompanied by activation energy Ea=4.45 Kcal/mole. These values are significantly lower than those we found for the macropinocytosis probe dextran (Q10=2.2 and Ea=7.2 Kcal/mole) which possesses an exponential dependence on temperature, characteristic of endocytosis processes. Tat-peptide and dextran do not interfere with each other's uptake rate and the ratio of Tat-peptide uptake to its extracellular concentration is ~15 times higher than that for dextran. In addition, Phloretin, a modulator of cell membrane dipole potential, is shown to increase dextran uptake but to reduce that of Tat. We conclude that the uptake of Tat differs from that of dextran in all parameters. Tat uptake proceeds by dual entry routes which differ by their energy dependence.
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Affiliation(s)
- Nadav Ben-Dov
- Department of Physiology and Pharmacology, Faculty of Medicine, Tel-Aviv University, 69978 Tel-Aviv, Israel.
| | - Rafi Korenstein
- Department of Physiology and Pharmacology, Faculty of Medicine, Tel-Aviv University, 69978 Tel-Aviv, Israel.
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13
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Cogger VC, Roessner U, Warren A, Fraser R, Le Couteur DG. A Sieve-Raft Hypothesis for the regulation of endothelial fenestrations. Comput Struct Biotechnol J 2013; 8:e201308003. [PMID: 24688743 PMCID: PMC3962122 DOI: 10.5936/csbj.201308003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 07/31/2013] [Accepted: 08/11/2013] [Indexed: 01/13/2023] Open
Affiliation(s)
- Victoria C Cogger
- Centre for Education and Research on Ageing and ANZAC Research Institute, Concord Hospital and University of Sydney, Sydney NSW, Australia ; Charles Perkins Centre, University of Sydney NSW Australia
| | - Ute Roessner
- Metabolomics Australia and Australian Centre for Plant Functional Genomics, The University of Melbourne, 3010 Victoria, Australia
| | - Alessandra Warren
- Centre for Education and Research on Ageing and ANZAC Research Institute, Concord Hospital and University of Sydney, Sydney NSW, Australia ; Charles Perkins Centre, University of Sydney NSW Australia
| | - Robin Fraser
- Christchurch School of Medicine, University of Otago, Christchurch NZ
| | - David G Le Couteur
- Centre for Education and Research on Ageing and ANZAC Research Institute, Concord Hospital and University of Sydney, Sydney NSW, Australia ; Charles Perkins Centre, University of Sydney NSW Australia
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14
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Ben-Dov N, Korenstein R. Proton-induced endocytosis is dependent on cell membrane fluidity, lipid-phase order and the membrane resting potential. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:2672-81. [PMID: 23911577 DOI: 10.1016/j.bbamem.2013.07.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 07/20/2013] [Accepted: 07/22/2013] [Indexed: 01/13/2023]
Abstract
Recently it has been shown that decreasing the extracellular pH of cells stimulates the formation of inward membrane invaginations and vesicles, accompanied by an enhanced uptake of macromolecules. This type of endocytosis was coined as proton-induced uptake (PIU). Though the initial induction of inward membrane curvature was rationalized in terms of proton-based increase of charge asymmetry across the membrane, the dependence of the phenomenon on plasma membrane characteristics is still unknown. The present study shows that depolarization of the membrane resting potential elevates PIU by 25%, while hyperpolarization attenuates it by 25%. Comparison of uptake in suspended and adherent cells implicates that the resting-potential affects PIU through remodeling the actin-cytoskeleton. The pH at the external interface of the cell membrane rather than the pH gradient across it determines the extent of PIU. PIU increases linearly upon temperature increase in the range of 4-36°C, in correlation with the membrane fluidity. The plasma membrane fluidity and the lipid phase order are modulated by enriching the cell's membrane with cholesterol, tergitol, dimethylsulfoxide, 6-ketocholestanol and phloretin and by cholesterol depletion. These treatments are shown to alter the extent of PIU and are better correlated with membrane fluidity than with the lipid phase order. We suggest that the lipid phase order and fluidity influence PIU by regulating the lipid order gradient across the perimeter of the lipid-condensed microdomains (rafts) and alter the characteristic tension line that separates the higher ordered lipid-domains from the lesser ordered ones.
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Affiliation(s)
- Nadav Ben-Dov
- Department of Physiology and Pharmacology, Faculty of Medicine, Tel-Aviv University, 69978 Tel-Aviv, Israel.
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15
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Vikdal M, Generalov R, Berg K. The photosensitizer disulfonated aluminum phthalocyanine reduces uptake and alters trafficking of fluid phase endocytosed drugs in vascular endothelial cells--impact on efficacy of photochemical internalization. Biochem Pharmacol 2013; 86:748-58. [PMID: 23876343 DOI: 10.1016/j.bcp.2013.07.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Revised: 07/10/2013] [Accepted: 07/11/2013] [Indexed: 01/31/2023]
Abstract
Targeting cancer vasculature is an emerging field in cancer treatment. Photochemical internalization (PCI) is a drug delivery technology based on photochemical lysis of drug-bearing endocytic vesicles originally designed to target cancer cells. Recent investigations have revealed a lower PCI efficacy in vascular endothelial cells (HUVECs) in vitro than in HT1080 fibrosarcoma cells. This manuscript aims to explore the limiting factor for the PCI effect in HUVECs. Cellular uptake of the photosensitizers AlPcS(2a) and TPPS(2a), and a model compound for macromolecular drugs taken up by fluid phase endocytosis, Alexa⁴⁸⁸-dextran, was explored by flow cytometry. The uptake of AlPcS(2a) and TPPS(2a) was 3.8-fold and 37-fold higher in HUVECs than in HT1080 cells, respectively, while the Alexa⁴⁸⁸-dextran uptake was 50% lower. AlPcS(2a) (but not TPPS(2a)) was shown to reduce Alexa⁴⁸⁸-dextran uptake in a concentration-dependent manner, resulting in 66% and 33% attenuation of Alexa⁴⁸⁸-dextran uptake at 20 μg/ml AlPcS(2a) in HUVECs and HT1080 cells respectively. Studies of intracellular localization of Alexa⁴⁸⁸-dextran and AlPcS(2a) by confocal microscopy in HUVECs uncovered a concentration-dependent AlPcS(2a)-induced inhibition of Alexa⁴⁸⁸-dextran trafficking into AlPcS(2a)-stained and acidic vesicles. The localization of Alexa⁴⁸⁸-dextran to AlPcS(2a)-localizing compartments was reduced by 40% when the AlPcS(2a) concentration was increased from 5 to 20 μg/ml. The treatment dose of AlPcS(2a) was found to influence on the efficacy of PCI of saporin, but to a lesser extent than expected considering the data from cellular uptake and intracellular trafficking of Alexa⁴⁸⁸-dextran. The implications of these results for further development of vascular targeting-PCI are discussed.
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Affiliation(s)
- Marie Vikdal
- Department of Radiation Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Montebello, N-0310 Oslo, Norway
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Ben-Dov N, Korenstein R. Actin-cytoskeleton rearrangement modulates proton-induced uptake. Exp Cell Res 2013; 319:946-54. [DOI: 10.1016/j.yexcr.2013.01.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2012] [Revised: 01/21/2013] [Accepted: 01/22/2013] [Indexed: 10/27/2022]
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Staneva G, Puff N, Seigneuret M, Conjeaud H, Angelova MI. Segregative clustering of Lo and Ld membrane microdomains induced by local pH gradients in GM1-containing giant vesicles: a lipid model for cellular polarization. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:16327-37. [PMID: 23121205 DOI: 10.1021/la3031107] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Several cell polarization processes are coupled to local pH gradients at the membrane surface. We have investigated the involvement of a lipid-mediated effect in such coupling. The influence of lateral pH gradients along the membrane surface on lipid microdomain dynamics in giant unilamellar vesicles containing phosphatidylcholine, sphingomyelin, cholesterol, and the ganglioside GM1 was studied. Lo/Ld phase separation was generated by photosensitization. A lateral pH gradient was established along the external membrane surface by acid local microinjection. The gradient promotes the segregation of microdomains: Lo domains within an Ld phase move toward the higher pH side, whereas Ld domains within an Lo phase move toward the lower pH side. This results in a polarization of the vesicle membrane into Lo and Ld phases poles in the axis of the proton source. A secondary effect is inward tubulation in the Ld phase. None of these processes occurs without GM1 or with the analog asialo-GM1. These are therefore related to the acidic character of the GM1 headgroup. LAURDAN fluorescence experiments on large unilamellar vesicles indicated that, with GM1, an increase in lipid packing occurs with decreasing pH, attributed to the lowering of repulsion between GM1 molecules. Packing increase is much higher for Ld phase vesicles than for Lo phase vesicles. It is proposed that the driving forces for domain vectorial segregative clustering and vesicle polarization are related to such differences in packing variations with pH decrease between the Lo and Ld phases. Such pH-driven domain clustering might play a role in cellular membrane polarization processes in which local lateral pH gradients are known to be important, such as migrating cells and epithelial cells.
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Affiliation(s)
- Galya Staneva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria
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Ben-Dov N, Rozman Grinberg I, Korenstein R. Electroendocytosis is driven by the binding of electrochemically produced protons to the cell's surface. PLoS One 2012; 7:e50299. [PMID: 23209699 PMCID: PMC3507776 DOI: 10.1371/journal.pone.0050299] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2012] [Accepted: 10/18/2012] [Indexed: 01/08/2023] Open
Abstract
Electroendocytosis involves the exposure of cells to pulsed low electric field and is emerging as a complementary method to electroporation for the incorporation of macromolecules into cells. The present study explores the underlying mechanism of electroendocytosis and its dependence on electrochemical byproducts formed at the electrode interface. Cell suspensions were exposed to pulsed low electric field in a partitioned device where cells are spatially restricted relative to the electrodes. The cellular uptake of dextran-FITC was analyzed by flow cytometery and visualized by confocal microscopy. We first show that uptake occurs only in cells adjacent to the anode. The enhanced uptake near the anode is found to depend on electric current density rather than on electric field strength, in the range of 5 to 65 V/cm. Electrochemically produced oxidative species that impose intracellular oxidative stress, do not play any role in the stimulated uptake. An inverse dependence is found between electrically induced uptake and the solution’s buffer capacity. Electroendocytosis can be mimicked by chemically acidifying the extracellular solution which promotes the enhanced uptake of dextran polymers and the uptake of plasmid DNA. Electrochemical production of protons at the anode interface is responsible for inducing uptake of macromolecules into cells exposed to a pulsed low electric field. Expanding the understanding of the mechanism involved in electric fields induced drug-delivery into cells, is expected to contribute to clinical therapy applications in the future.
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Affiliation(s)
- Nadav Ben-Dov
- Department of Physiology and Pharmacology, Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Inna Rozman Grinberg
- Department of Physiology and Pharmacology, Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Rafi Korenstein
- Department of Physiology and Pharmacology, Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
- * E-mail:
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