1
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Koch D, Alexandrovich A, Funk F, Kho AL, Schmitt JP, Gautel M. Molecular noise filtering in the β-adrenergic signaling network by phospholamban pentamers. Cell Rep 2021; 36:109448. [PMID: 34320358 PMCID: PMC8333238 DOI: 10.1016/j.celrep.2021.109448] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 04/16/2021] [Accepted: 07/05/2021] [Indexed: 02/07/2023] Open
Abstract
Phospholamban (PLN) is an important regulator of cardiac calcium handling due to its ability to inhibit the calcium ATPase SERCA. β-Adrenergic stimulation reverses SERCA inhibition via PLN phosphorylation and facilitates fast calcium reuptake. PLN also forms pentamers whose physiological significance has remained elusive. Using mathematical modeling combined with biochemical and cell biological experiments, we show that pentamers regulate both the dynamics and steady-state levels of monomer phosphorylation. Substrate competition by pentamers and a feed-forward loop involving inhibitor-1 can delay monomer phosphorylation by protein kinase A (PKA), whereas cooperative pentamer dephosphorylation enables bistable PLN steady-state phosphorylation. Simulations show that phosphorylation delay and bistability act as complementary filters that reduce the effect of random fluctuations in PKA activity, thereby ensuring consistent monomer phosphorylation and SERCA activity despite noisy upstream signals. Preliminary analyses suggest that the PLN mutation R14del could impair noise filtering, offering a new perspective on how this mutation causes cardiac arrhythmias.
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Affiliation(s)
- Daniel Koch
- Randall Centre for Cell and Molecular Biophysics, King's College London, SE1 1UL London, UK.
| | | | - Florian Funk
- Institute of Pharmacology and Clinical Pharmacology, and Cardiovascular Research Institute Düsseldorf (CARID), University Hospital Düsseldorf, 40225 Düsseldorf, Germany
| | - Ay Lin Kho
- Randall Centre for Cell and Molecular Biophysics, King's College London, SE1 1UL London, UK
| | - Joachim P Schmitt
- Institute of Pharmacology and Clinical Pharmacology, and Cardiovascular Research Institute Düsseldorf (CARID), University Hospital Düsseldorf, 40225 Düsseldorf, Germany
| | - Mathias Gautel
- Randall Centre for Cell and Molecular Biophysics, King's College London, SE1 1UL London, UK
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2
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Advanced Static and Dynamic Fluorescence Microscopy Techniques to Investigate Drug Delivery Systems. Pharmaceutics 2021; 13:pharmaceutics13060861. [PMID: 34208080 PMCID: PMC8230741 DOI: 10.3390/pharmaceutics13060861] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 06/07/2021] [Accepted: 06/08/2021] [Indexed: 01/01/2023] Open
Abstract
In the past decade(s), fluorescence microscopy and laser scanning confocal microscopy (LSCM) have been widely employed to investigate biological and biomimetic systems for pharmaceutical applications, to determine the localization of drugs in tissues or entire organisms or the extent of their cellular uptake (in vitro). However, the diffraction limit of light, which limits the resolution to hundreds of nanometers, has for long time restricted the extent and quality of information and insight achievable through these techniques. The advent of super-resolution microscopic techniques, recognized with the 2014 Nobel prize in Chemistry, revolutionized the field thanks to the possibility to achieve nanometric resolution, i.e., the typical scale length of chemical and biological phenomena. Since then, fluorescence microscopy-related techniques have acquired renewed interest for the scientific community, both from the perspective of instrument/techniques development and from the perspective of the advanced scientific applications. In this contribution we will review the application of these techniques to the field of drug delivery, discussing how the latest advancements of static and dynamic methodologies have tremendously expanded the experimental opportunities for the characterization of drug delivery systems and for the understanding of their behaviour in biologically relevant environments.
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3
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Glaves JP, Primeau JO, Gorski PA, Espinoza-Fonseca LM, Lemieux MJ, Young HS. Interaction of a Sarcolipin Pentamer and Monomer with the Sarcoplasmic Reticulum Calcium Pump, SERCA. Biophys J 2019; 118:518-531. [PMID: 31858977 DOI: 10.1016/j.bpj.2019.11.3385] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 10/30/2019] [Accepted: 11/18/2019] [Indexed: 11/27/2022] Open
Abstract
The sequential rise and fall of cytosolic calcium underlies the contraction-relaxation cycle of muscle cells. Whereas contraction is initiated by the release of calcium from the sarcoplasmic reticulum, muscle relaxation involves the active transport of calcium back into the sarcoplasmic reticulum. This reuptake of calcium is catalyzed by the sarcoendoplasmic reticulum Ca2+-ATPase (SERCA), which plays a lead role in muscle contractility. The activity of SERCA is regulated by small membrane protein subunits, the most well-known being phospholamban (PLN) and sarcolipin (SLN). SLN physically interacts with SERCA and differentially regulates contractility in skeletal and atrial muscle. SLN has also been implicated in skeletal muscle thermogenesis. Despite these important roles, the structural mechanisms by which SLN modulates SERCA-dependent contractility and thermogenesis remain unclear. Here, we functionally characterized wild-type SLN and a pair of mutants, Asn4-Ala and Thr5-Ala, which yielded gain-of-function behavior comparable to what has been found for PLN. Next, we analyzed two-dimensional crystals of SERCA in the presence of wild-type SLN by electron cryomicroscopy. The fundamental units of the crystals are antiparallel dimer ribbons of SERCA, known for decades as an assembly of calcium-free SERCA molecules induced by the addition of decavanadate. A projection map of the SERCA-SLN complex was determined to a resolution of 8.5 Å, which allowed the direct visualization of an SLN pentamer. The SLN pentamer was found to interact with transmembrane segment M3 of SERCA, although the interaction appeared to be indirect and mediated by an additional density consistent with an SLN monomer. This SERCA-SLN complex correlated with the ability of SLN to decrease the maximal activity of SERCA, which is distinct from the ability of PLN to increase the maximal activity of SLN. Protein-protein docking and molecular dynamics simulations provided models for the SLN pentamer and the novel interaction between SERCA and an SLN monomer.
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Affiliation(s)
- John Paul Glaves
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Joseph O Primeau
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Przemek A Gorski
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - L Michel Espinoza-Fonseca
- Center for Arrhythmia Research, Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, Michigan
| | - M Joanne Lemieux
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Howard S Young
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada.
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4
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Magnani C, Montis C, Mangiapia G, Mingotaud AF, Mingotaud C, Roux C, Joseph P, Berti D, Lonetti B. Hybrid vesicles from lipids and block copolymers: Phase behavior from the micro- to the nano-scale. Colloids Surf B Biointerfaces 2018; 168:18-28. [DOI: 10.1016/j.colsurfb.2018.01.042] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 12/21/2017] [Accepted: 01/20/2018] [Indexed: 12/18/2022]
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5
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The polyplex, protein corona, cell interplay: Tips and drawbacks. Colloids Surf B Biointerfaces 2018; 168:60-67. [DOI: 10.1016/j.colsurfb.2018.01.040] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 11/23/2017] [Accepted: 01/20/2018] [Indexed: 12/12/2022]
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6
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di Gregorio MC, Severoni E, Travaglini L, Gubitosi M, Sennato S, Mura F, Redondo-Gómez C, Jover A, Pavel NV, Galantini L. Bile acid derivative-based catanionic mixtures: versatile tools for superficial charge modulation of supramolecular lamellae and nanotubes. Phys Chem Chem Phys 2018; 20:18957-18968. [PMID: 29972162 DOI: 10.1039/c8cp02745e] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Self-assembled structures formed by mixtures of cationic and anionic surfactants are interesting tools for applications requiring interactions with charged particles and molecules. Nevertheless, they present instability close to the equimolar composition and poor morphological versatility, which is generally restricted to vesicles and micelles. Against this general trend, we report on bile salt derivative based catanionic mixtures assembling in tubules and lamellae depending on the mixture composition. Electrophoretic mobility measurements prove that the composition also dictates their superficial charge, which can be tuned from negative to positive by increasing the positively charged surfactant fraction in the mixtures. The study of the catanionic aggregates was conducted by means of microscopy and spectroscopy techniques and compared to the self-assembly behaviors of the individual building blocks. This study broadens the so far small array of bile salt derivative catanionic systems, confirming their distinctive behavior in the spectrum of catanionic mixtures.
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7
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Montis C, Generini V, Boccalini G, Bergese P, Bani D, Berti D. Model lipid bilayers mimic non-specific interactions of gold nanoparticles with macrophage plasma membranes. J Colloid Interface Sci 2018; 516:284-294. [DOI: 10.1016/j.jcis.2018.01.064] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 01/17/2018] [Accepted: 01/18/2018] [Indexed: 12/31/2022]
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8
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Smeazzetto S, Tadini-Buoninsegni F, Thiel G, Moncelli MR. Selectivity of the phospholamban ion channel investigated by single channel measurements. J Electroanal Chem (Lausanne) 2018. [DOI: 10.1016/j.jelechem.2018.01.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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9
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Montis C, Busatto S, Valle F, Zendrini A, Salvatore A, Gerelli Y, Berti D, Bergese P. Biogenic Supported Lipid Bilayers from Nanosized Extracellular Vesicles. ACTA ACUST UNITED AC 2018. [DOI: 10.1002/adbi.201700200] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Costanza Montis
- Department of Chemistry; University of Florence and CSGI; via della Lastruccia 3 50019 Florence Italy
| | - Sara Busatto
- Department of Molecular and Translational Medicine; University of Brescia; CSGI and INSTM, viale Europa 11 25123 Brescia Italy
| | | | - Andrea Zendrini
- Department of Molecular and Translational Medicine; University of Brescia; CSGI and INSTM, viale Europa 11 25123 Brescia Italy
| | - Annalisa Salvatore
- Department of Chemistry; University of Florence and CSGI; via della Lastruccia 3 50019 Florence Italy
| | - Yuri Gerelli
- Institut Laue-Langevin; 71 Avenue des Martyrs BP 156 F-38000 Grenoble France
| | - Debora Berti
- Department of Chemistry; University of Florence and CSGI; via della Lastruccia 3 50019 Florence Italy
| | - Paolo Bergese
- Department of Molecular and Translational Medicine; University of Brescia; CSGI and INSTM, viale Europa 11 25123 Brescia Italy
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10
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Mendozza M, Montis C, Caselli L, Wolf M, Baglioni P, Berti D. On the thermotropic and magnetotropic phase behavior of lipid liquid crystals containing magnetic nanoparticles. NANOSCALE 2018; 10:3480-3488. [PMID: 29404545 DOI: 10.1039/c7nr08478a] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The inclusion of superparamagnetic iron oxide nanoparticles (SPIONs) in lipid mesophases is a promising strategy for drug-delivery applications, combining the innate biocompatibility of lipid architectures with SPIONs' response to external magnetic fields. Moreover, the organization of SPIONs within the lipid scaffold can lead to locally enhanced SPIONs concentration and improved magnetic response, which is key to overcome the current limitations of hyperthermic treatments. Here we present a Small-Angle X-ray Scattering (SAXS) structural investigation of the thermotropic and magnetotropic behavior of glyceryl monooleate (GMO)/water mesophases, loaded with hydrophobic SPIONs. We prove that even very low amounts of SPIONs deeply alter the phase behavior and thermotropic properties of the mesophases, promoting a cubic to hexagonal phase transition, which is similarly induced upon application of an Alternating Magnetic Field (AMF). Moreover, in the hexagonal phase SPIONs spontaneously self-assemble within the lipid scaffold into a linear supraparticle. This phase behavior is interpreted in the framework of the Helfrich's theory, which shows that SPIONs affect the mesophase both from a viscoelastic and from a structural standpoint. Finally, the dispersion of these cubic phases into stable magnetic colloidal particles, which retain their liquid crystalline internal structure, is addressed as a promising route towards magneto-responsive drug-delivery systems (DDS).
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Affiliation(s)
- Marco Mendozza
- Department of chemistry and CSGI, University of Florence, Via della Lastruccia 3, Sesto Fiorentino, 50019 Florence, Italy.
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11
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Mallardi A, Nuzziello N, Liguori M, Avolio C, Palazzo G. Counting of peripheral extracellular vesicles in Multiple Sclerosis patients by an improved nanoplasmonic assay and dynamic light scattering. Colloids Surf B Biointerfaces 2018; 168:134-142. [PMID: 29428682 DOI: 10.1016/j.colsurfb.2018.02.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 01/27/2018] [Accepted: 02/03/2018] [Indexed: 01/08/2023]
Abstract
Extracellular vesicles (EVs) are vesicles naturally secreted by the majority of human cells. Being composed by a closed phospholipid bilayer secluding proteins and RNAs they are used to transfer molecular information to other cells, thereby influencing the recipient cell functions. Despite the increasingly recognized relevance of EVs, the clarification of their physiological role is hampered by the lack of suitable analytical tools for their quantification and characterization. In this study, we have implemented a nanoplasmonic assay, previously proposed for the purity of the EV fractions, to achieve a robust analytical protocol in order to quantify the total phospholipid concentration (CPL) and the EVs number. We show how the coupling of the nanoplasmonic assay with serial dilutions of the unknown sample allows, by simple visual inspection, to detect deviations from the physiological EVs content. The use of a response that depends on the absorbance values at three wavelengths permits to reduce the limit of detection of CPL to 5 μM (total) and the limit of quantification to 35 μM. We also propose a method that takes into account the spread in EV size when the concentration of phospholipids is turned into a concentration of vesicles. The proposed analytical protocol is successfully applied to a small cohort of Multiple Sclerosis patients examined in different stages of their clinical diseases.
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Affiliation(s)
- Antonia Mallardi
- CNR-IPCF, National Research Council of Italy, Institute for the Chemical Physics Processes, Division of Bari, Bari, Italy
| | - Nicoletta Nuzziello
- National Research Council of Italy, Institute of Biomedical Technologies, Section of Bari, Bari, Italy; Department of Basic Sciences, Neurosciences and Sense Organs, University of Bari, Bari, Italy
| | - Maria Liguori
- National Research Council of Italy, Institute of Biomedical Technologies, Section of Bari, Bari, Italy
| | - Carlo Avolio
- Department of Medical and Surgical Sciences, University of Foggia, Foggia, Italy
| | - Gerardo Palazzo
- Department of Chemistry and Center for colloid and surface science (CSGI), University of Bari, Bari, Italy; CNR-NANOTEC, National Research Council of Italy, Istitute of Nanotechnology, Bari, Italy.
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12
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Smeazzetto S, Armanious GP, Moncelli MR, Bak JJ, Lemieux MJ, Young HS, Tadini-Buoninsegni F. Conformational memory in the association of the transmembrane protein phospholamban with the sarcoplasmic reticulum calcium pump SERCA. J Biol Chem 2017; 292:21330-21339. [PMID: 29081402 DOI: 10.1074/jbc.m117.794453] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 10/19/2017] [Indexed: 11/06/2022] Open
Abstract
The sarcoplasmic reticulum Ca2+-ATPase SERCA promotes muscle relaxation by pumping calcium ions from the cytoplasm into the sarcoplasmic reticulum. SERCA activity is regulated by a variety of small transmembrane peptides, most notably by phospholamban in cardiac muscle and sarcolipin in skeletal muscle. However, how phospholamban and sarcolipin regulate SERCA is not fully understood. In the present study, we evaluated the effects of phospholamban and sarcolipin on calcium translocation and ATP hydrolysis by SERCA under conditions that mimic environments in sarcoplasmic reticulum membranes. For pre-steady-state current measurements, proteoliposomes containing SERCA and phospholamban or sarcolipin were adsorbed to a solid-supported membrane and activated by substrate concentration jumps. We observed that phospholamban altered ATP-dependent calcium translocation by SERCA within the first transport cycle, whereas sarcolipin did not. Using pre-steady-state charge (calcium) translocation and steady-state ATPase activity under substrate conditions (various calcium and/or ATP concentrations) promoting particular conformational states of SERCA, we found that the effect of phospholamban on SERCA depends on substrate preincubation conditions. Our results also indicated that phospholamban can establish an inhibitory interaction with multiple SERCA conformational states with distinct effects on SERCA's kinetic properties. Moreover, we noted multiple modes of interaction between SERCA and phospholamban and observed that once a particular mode of association is engaged it persists throughout the SERCA transport cycle and multiple turnover events. These observations are consistent with conformational memory in the interaction between SERCA and phospholamban, thus providing insights into the physiological role of phospholamban and its regulatory effect on SERCA transport activity.
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Affiliation(s)
- Serena Smeazzetto
- From the Department of Chemistry "Ugo Schiff," University of Florence, 50019 Sesto Fiorentino, Italy and
| | - Gareth P Armanious
- Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Maria Rosa Moncelli
- From the Department of Chemistry "Ugo Schiff," University of Florence, 50019 Sesto Fiorentino, Italy and
| | - Jessi J Bak
- Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - M Joanne Lemieux
- Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Howard S Young
- Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
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13
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Espinoza-Fonseca LM. The Ca 2+-ATPase pump facilitates bidirectional proton transport across the sarco/endoplasmic reticulum. MOLECULAR BIOSYSTEMS 2017; 13:633-637. [PMID: 28290590 DOI: 10.1039/c7mb00065k] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Ca2+ transport across the sarco/endoplasmic reticulum (SR) plays an essential role in intracellular Ca2+ homeostasis, signalling, cell differentiation and muscle contractility. During SR Ca2+ uptake and release, proton fluxes are required to balance the charge deficit generated by the exchange of Ca2+ and other ions across the SR. During Ca2+ uptake by the SR Ca2+-ATPase (SERCA), two protons are countertransported from the SR lumen to the cytosol, thus partially compensating for the charge moved by Ca2+ transport. Studies have shown that protons are also transported from the cytosol to the lumen during Ca2+ release, but a transporter that facilitates proton transport into the SR lumen has not been described. In this article we propose that SERCA forms pores that facilitate bidirectional proton transport across the SR. We describe the location and structure of water-filled pores in SERCA that form cytosolic and luminal pathways for protons to cross the SR membrane. Based on this structural information, we suggest mechanistic models for proton translocation to the cytosol during active Ca2+ transport, and into the SR lumen during SERCA inhibition by endogenous regulatory proteins. Finally, we discuss the physiological consequences of SERCA-mediated bidirectional proton transport across the SR membrane of muscle and non-muscle cells.
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Affiliation(s)
- L Michel Espinoza-Fonseca
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
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14
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Mangiapia G, Gvaramia M, Kuhrts L, Teixeira J, Koutsioubas A, Soltwedel O, Frielinghaus H. Effect of benzocaine and propranolol on phospholipid-based bilayers. Phys Chem Chem Phys 2017; 19:32057-32071. [DOI: 10.1039/c7cp06077g] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Drug/bilayer interactions are fundamental in determining the action mechanism of active ingredients. Neutron techniques represent unique tools for having a clear comprehension of such interactions.
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Affiliation(s)
- G. Mangiapia
- Forschungszentrum Jülich GmbH
- Jülich Centre for Neutron Science Außenstelle am Heinz Maier-Leibnitz Zentrum
- D-85747 Garching
- Germany
| | - M. Gvaramia
- Forschungszentrum Jülich GmbH
- Jülich Centre for Neutron Science Außenstelle am Heinz Maier-Leibnitz Zentrum
- D-85747 Garching
- Germany
- Ivane Javakhishvili Tbilisi State University
| | - L. Kuhrts
- Forschungszentrum Jülich GmbH
- Jülich Centre for Neutron Science Außenstelle am Heinz Maier-Leibnitz Zentrum
- D-85747 Garching
- Germany
| | - J. Teixeira
- Laboratoire Léon Brillouin (CEA-CNRS)
- CEA-Saclay
- F-91191 Gif-sur-Yvette CEDEX
- France
| | - A. Koutsioubas
- Forschungszentrum Jülich GmbH
- Jülich Centre for Neutron Science Außenstelle am Heinz Maier-Leibnitz Zentrum
- D-85747 Garching
- Germany
| | - O. Soltwedel
- Heinz Maier-Leibnitz Zentrum
- Technische Universität München
- D-85747 Garching
- Germany
| | - H. Frielinghaus
- Forschungszentrum Jülich GmbH
- Jülich Centre for Neutron Science Außenstelle am Heinz Maier-Leibnitz Zentrum
- D-85747 Garching
- Germany
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15
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Boccalini G, Conti L, Montis C, Bani D, Bencini A, Berti D, Giorgi C, Mengoni A, Valtancoli B. Methylene blue-containing liposomes as new photodynamic anti-bacterial agents. J Mater Chem B 2017; 5:2788-2797. [DOI: 10.1039/c6tb03367a] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Novel cationic liposomes containing the photo-activatable drug methylene blue (MB) strongly enhance the antibacterial activity of MB towards Gram-negative bacteria and improve biofilm penetration.
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Affiliation(s)
- Giulia Boccalini
- Department of Experimental & Clinical Medicine
- Research Unit of Histology & Embryology
- University of Florence
- Italy
| | - Luca Conti
- Department of Chemistry Ugo Schiff
- University of Florence
- Sesto Fiorentino (FI)
- Italy
| | - Costanza Montis
- Department of Chemistry Ugo Schiff and CSGI
- University of Florence
- Sesto Fiorentino (FI)
- Italy
| | - Daniele Bani
- Department of Experimental & Clinical Medicine
- Research Unit of Histology & Embryology
- University of Florence
- Italy
| | - Andrea Bencini
- Department of Chemistry Ugo Schiff
- University of Florence
- Sesto Fiorentino (FI)
- Italy
| | - Debora Berti
- Department of Chemistry Ugo Schiff and CSGI
- University of Florence
- Sesto Fiorentino (FI)
- Italy
| | - Claudia Giorgi
- Department of Chemistry Ugo Schiff
- University of Florence
- Sesto Fiorentino (FI)
- Italy
| | - Alessio Mengoni
- Department of Biology
- University of Florence
- Sesto Fiorentino (FI)
- Italy
| | - Barbara Valtancoli
- Department of Chemistry Ugo Schiff
- University of Florence
- Sesto Fiorentino (FI)
- Italy
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16
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Bian T, Autry JM, Casemore D, Li J, Thomas DD, He G, Xing C. Direct detection of SERCA calcium transport and small-molecule inhibition in giant unilamellar vesicles. Biochem Biophys Res Commun 2016; 481:206-211. [PMID: 27815070 DOI: 10.1016/j.bbrc.2016.10.096] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 10/12/2016] [Indexed: 10/20/2022]
Abstract
We have developed a charge-mediated fusion method to reconstitute the sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) in giant unilamellar vesicles (GUV). Intracellular Ca2+ transport by SERCA controls key processes in human cells such as proliferation, signaling, and contraction. Small-molecule effectors of SERCA are urgently needed as therapeutics for Ca2+ dysregulation in human diseases including cancer, diabetes, and heart failure. Here we report the development of a method for efficiently reconstituting SERCA in GUV, and we describe a streamlined protocol based on optimized parameters (e.g., lipid components, SERCA preparation, and activity assay requirements). ATP-dependent Ca2+ transport by SERCA in single GUV was detected directly using confocal fluorescence microscopy with the Ca2+ indicator Fluo-5F. The GUV reconstitution system was validated for functional screening of Ca2+ transport using thapsigargin (TG), a small-molecule inhibitor of SERCA currently in clinical trials as a prostate cancer prodrug. The GUV system overcomes the problem of inhibitory Ca2+ accumulation for SERCA in native and reconstituted small unilamellar vesicles (SUV). We propose that charge-mediated fusion provides a widely-applicable method for GUV reconstitution of clinically-important membrane transport proteins. We conclude that GUV reconstitution is a technological advancement for evaluating small-molecule effectors of SERCA.
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Affiliation(s)
- Tengfei Bian
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, 2231 6th St SE, Minneapolis, MN 55455, United States; State Key Laboratory of Fine Chemicals, R&D Center of Membrane Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Joseph M Autry
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, 321 Church St SE, Minneapolis, MN 55455, United States; Biophysical Technology Center, Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, 321 Church St SE, Minneapolis, MN 55455, United States
| | - Denise Casemore
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, 2231 6th St SE, Minneapolis, MN 55455, United States
| | - Ji Li
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, 321 Church St SE, Minneapolis, MN 55455, United States; Biophysical Technology Center, Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, 321 Church St SE, Minneapolis, MN 55455, United States
| | - David D Thomas
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, 321 Church St SE, Minneapolis, MN 55455, United States
| | - Gaohong He
- State Key Laboratory of Fine Chemicals, R&D Center of Membrane Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Chengguo Xing
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, 2231 6th St SE, Minneapolis, MN 55455, United States.
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