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Shram SI, Shcherbakova TA, Abramova TV, Smirnovskaya MS, Balandina AI, Kulikov AV, Švedas VK, Silnikov VN, Myasoedov NF, Nilov DK. A New Approach for Studying Poly(ADP-Ribose) Polymerase Inhibitors Using Permeabilized Adherent Cells. BIOCHEMISTRY. BIOKHIMIIA 2024; 89:1619-1630. [PMID: 39418520 DOI: 10.1134/s0006297924090086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 05/03/2024] [Accepted: 06/10/2024] [Indexed: 10/19/2024]
Abstract
Poly(ADP-ribose) polymerase (PARP) inhibitors have been proposed as pharmacological agents in the treatment of various diseases. Recently, factors and mechanisms responsible for regulating PARP catalytic activity have been identified, some of which can significantly influence the effectiveness of inhibitors of this enzyme. In this regard, it is important to develop new models and methods that would reflect the cellular context in which PARP functions. We proposed to use digitonin-permeabilized adherent cells to study poly(ADP-ribosyl)ation reaction (PARylation) in order to maintain the nuclear localization of PARP and to control the concentrations of its substrate (NAD+) and tested compounds in the cell. A specific feature of the approach is that before permeabilization, cellular PARP is converted to the DNA-bound state under conditions preventing premature initiation of the PARylation reaction. Experiments were carried out in rat H9c2 cardiomyoblasts. The activity of PARP in permeabilized cells was analyzed by measuring the immunofluorescence of the reaction product poly(ADP-ribose). The method was verified in the studies of PARP inhibition by the classic inhibitor 3-aminobenzamide and a number of new 7-methylguanine derivatives. One of them, 7,8-dimethylguanine, was found to be a stronger inhibitor compared to 7-methylguanine, due to a formation of additional hydrophobic contact with the protein. The proposed approach opens up new prospects for studying the mechanisms of PARP activity regulation in cells and can be used in high-throughput screening of PARP inhibitors.
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Affiliation(s)
- Stanislav I Shram
- National Research Centre "Kurchatov Institute", Moscow, 123182, Russia.
| | - Tatyana A Shcherbakova
- Belozersky Institute of Physicochemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia
| | - Tatyana V Abramova
- Institute of Chemical Biology and Fundamental Medicine, Russian Academy of Sciences, Siberian Branch, Novosibirsk, 630090, Russia
| | | | - Anastasia I Balandina
- National Research Centre "Kurchatov Institute", Moscow, 123182, Russia
- Faculty of Biotechnology and Industrial Ecology, Mendeleev University of Chemical Technology of Russia, Moscow, 125047, Russia
| | - Andrey V Kulikov
- Medical Institute, Peoples' Friendship University of Russia, Moscow, 117198, Russia
| | - Vytas K Švedas
- Belozersky Institute of Physicochemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, 119234, Russia
| | - Vladimir N Silnikov
- Institute of Chemical Biology and Fundamental Medicine, Russian Academy of Sciences, Siberian Branch, Novosibirsk, 630090, Russia
| | | | - Dmitry K Nilov
- Belozersky Institute of Physicochemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia
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Zhang S, Orozco CC, Tang LWT, Racich J, Carlo AA, Chang G, Tess D, Keefer C, Di L. Characterization and Applications of Permeabilized Hepatocytes in Drug Discovery. AAPS J 2024; 26:38. [PMID: 38548986 DOI: 10.1208/s12248-024-00907-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 03/02/2024] [Indexed: 04/02/2024] Open
Abstract
Hepatocytes are one of the most physiologically relevant in vitro liver systems for human translation of clearance and drug-drug interactions (DDI). However, the cell membranes of hepatocytes can limit the entry of certain compounds into the cells for metabolism and DDI. Passive permeability through hepatocytes can be different in vitro and in vivo, which complicates the human translation. Permeabilized hepatocytes offer a useful tool to probe mechanistic understanding of permeability-limited metabolism and DDI. Incubation with saponin of 0.01% at 0.5 million cells/mL and 0.05% at 5 million cells/mL for 5 min at 37°C completely permeabilized the plasma membrane of hepatocytes, while leaving the membranes of subcellular organelles intact. Permeabilized hepatocytes maintained similar enzymatic activity as intact unpermeabilized hepatocytes and can be stored at -80°C for at least 7 months. This approach reduces costs by preserving leftover hepatocytes. The relatively low levels of saponin in permeabilized hepatocytes had no significant impact on the enzymatic activity. As the cytosolic contents leak out from permeabilized hepatocytes, cofactors need to be added to enable metabolic reactions. Cytosolic enzymes will no longer be present if the media are removed after cells are permeabilized. Hence permeabilized hepatocytes with and without media removal may potentially enable reaction phenotyping of cytosolic enzymes. Although permeabilized hepatocytes work similarly as human liver microsomes and S9 fractions experimentally requiring addition of cofactors, they behave more like hepatocytes maintaining enzymatic activities for over 4 h. Permeabilized hepatocytes are a great addition to the drug metabolism toolbox to provide mechanistic insights.
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Affiliation(s)
- Sam Zhang
- Pharmacokinetics, Dynamics and Metabolism, Pfizer Worldwide Research and Development, Groton, Connecticut, 06340, USA
| | - Christine C Orozco
- Pharmacokinetics, Dynamics and Metabolism, Pfizer Worldwide Research and Development, Groton, Connecticut, 06340, USA
| | - Lloyd Wei Tat Tang
- Pharmacokinetics, Dynamics and Metabolism, Pfizer Worldwide Research and Development, Groton, Connecticut, 06340, USA
| | - Jillian Racich
- Pharmacokinetics, Dynamics and Metabolism, Pfizer Worldwide Research and Development, Groton, Connecticut, 06340, USA
| | - Anthony A Carlo
- Pharmacokinetics, Dynamics and Metabolism, Pfizer Worldwide Research and Development, Groton, Connecticut, 06340, USA
| | - George Chang
- Pharmacokinetics, Dynamics and Metabolism, Pfizer Worldwide Research and Development, Groton, Connecticut, 06340, USA
| | - David Tess
- Pharmacokinetics, Dynamics and Metabolism, Pfizer Worldwide Research and Development, Groton, Connecticut, 06340, USA
| | - Christopher Keefer
- Pharmacokinetics, Dynamics and Metabolism, Pfizer Worldwide Research and Development, Groton, Connecticut, 06340, USA
| | - Li Di
- Pharmacokinetics, Dynamics and Metabolism, Pfizer Worldwide Research and Development, Groton, Connecticut, 06340, USA.
- Recursion Pharmaceuticals, Salt Lake City, Utah, 84101, USA.
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Popgeorgiev N, Gil C, Berthenet K, Bertolin G, Ichim G. Shedding light on mitochondrial outer-membrane permeabilization and membrane potential: State of the art methods and biosensors. Semin Cell Dev Biol 2024; 156:58-65. [PMID: 37438211 DOI: 10.1016/j.semcdb.2023.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Revised: 06/21/2023] [Accepted: 07/04/2023] [Indexed: 07/14/2023]
Abstract
Membrane structural integrity is essential for optimal mitochondrial function. These organelles produce the energy needed for all vital processes, provided their outer and inner membranes are intact. This prevents the release of mitochondrial apoptogenic factors into the cytosol and ensures intact mitochondrial membrane potential (ΔΨm) to sustain ATP production. Cell death by apoptosis is generally triggered by outer mitochondrial membrane permeabilization (MOMP), tightly coupled with loss of ΔΨ m. As these two processes are essential for both mitochondrial function and cell death, researchers have devised various techniques to assess them. Here, we discuss current methods and biosensors available for detecting MOMP and measuring ΔΨ m, focusing on their advantages and limitations and discuss what new imaging tools are needed to improve our knowledge of mitochondrial function.
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Affiliation(s)
- Nikolay Popgeorgiev
- Cancer Cell Death laboratory, part of LabEX DEVweCAN, Cancer Initiation and Tumoral Cell Identity Department, CRCL, U1052 INSERM, UMR CNRS 5286, Centre Léon Bérard, Université Lyon I, Institut Convergence PLAsCAN Lyon, France; Institut Universitaire de France (IUF), Paris, France
| | - Clara Gil
- Cancer Cell Death laboratory, part of LabEX DEVweCAN, Cancer Initiation and Tumoral Cell Identity Department, CRCL, U1052 INSERM, UMR CNRS 5286, Centre Léon Bérard, Université Lyon I, Institut Convergence PLAsCAN Lyon, France
| | - Kevin Berthenet
- Cancer Cell Death laboratory, part of LabEX DEVweCAN, Cancer Initiation and Tumoral Cell Identity Department, CRCL, U1052 INSERM, UMR CNRS 5286, Centre Léon Bérard, Université Lyon I, Institut Convergence PLAsCAN Lyon, France
| | - Giulia Bertolin
- CNRS, Univ Rennes, IGDR (Institute of Genetics and Development of Rennes), Rennes, France.
| | - Gabriel Ichim
- Cancer Cell Death laboratory, part of LabEX DEVweCAN, Cancer Initiation and Tumoral Cell Identity Department, CRCL, U1052 INSERM, UMR CNRS 5286, Centre Léon Bérard, Université Lyon I, Institut Convergence PLAsCAN Lyon, France.
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Al-Romaiyan A, Persaud SJ, Jones PM. Identification of Potential Plant-Derived Pancreatic Beta-Cell-Directed Agents Using New Custom-Designed Screening Method: Gymnema sylvestre as an Example. Molecules 2023; 29:194. [PMID: 38202777 PMCID: PMC10780566 DOI: 10.3390/molecules29010194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 12/23/2023] [Accepted: 12/25/2023] [Indexed: 01/12/2024] Open
Abstract
BACKGROUND Folk medicines are attractive therapeutic agents for treating type 2 diabetes mellitus (T2DM). Most plant extracts that have been suggested to restore β-cells function were tested in vivo. Some only have been tested in vitro to determine whether they have a direct effect on β-cells islets of Langerhans. Currently, there are no defined criteria for screening of β-cell-directed plant-based remedies as potential antidiabetic agents. SUMMARY In this review, we have identified certain criteria/characteristics that can be used to generate a "screening portfolio" to identify plant extracts as potential β-cell-directed agents for the treatment of T2DM. To validate our screening method, we studied the potential therapeutic efficacy of a Gymnema sylvestre (GS) extract using the screening criteria detailed in the review. Six criteria have been identified and validated using OSA®, a GS extract. By using this screening method, we show that OSA® fulfilled most of the criteria identified for an effective β-cell-directed antidiabetic therapy, being an effective insulin-releasing agent at nontoxic concentrations; maintaining β-cell insulin content by stimulating a concomitant increase in insulin gene transcription; maintaining β-cell mass by protecting against apoptosis; and being effective at maintaining normoglycemia in vivo in a mouse model and a human cohort with T2DM. KEY MESSAGES The present review has highlighted the importance of having a screening portfolio for plant extracts that have potential antidiabetic effects in the treatment of T2DM. We propose that this screening method should be adopted for future studies to identify new β-cell-directed antidiabetic plant derived agents.
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Affiliation(s)
- Altaf Al-Romaiyan
- Department of Pharmacology and Therapeutics, College of Pharmacy, Kuwait University, Jabriya 046302, Kuwait
| | - Shanta J. Persaud
- Department of Diabetes, School of Cardiovascular Medicine & Sciences, Faculty of Life Sciences and Medicine, King’s College London, London SE1 1UL, UK; (S.J.P.); (P.M.J.)
| | - Peter M. Jones
- Department of Diabetes, School of Cardiovascular Medicine & Sciences, Faculty of Life Sciences and Medicine, King’s College London, London SE1 1UL, UK; (S.J.P.); (P.M.J.)
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Fitzsimons LA, Staurengo-Ferrari L, Bogen O, Araldi D, Bonet IJM, Jordan EE, Levine JD, Tucker KL. The Primary Cilium and its Hedgehog Signaling in Nociceptors Contribute to Inflammatory and Neuropathic Pain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.27.573420. [PMID: 38234719 PMCID: PMC10793418 DOI: 10.1101/2023.12.27.573420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
The primary cilium, a 1-3 μm long hair-like structure protruding from the surface of almost all cells in the vertebrate body, is critical for neuronal development and also functions in the adult. As the migratory neural crest settles into dorsal root ganglia (DRG) sensory neurons elaborate a single primary cilium at their soma that is maintained into adult stages. While it is not known if primary cilia are expressed in nociceptors, or their potential function in the mature DRG neuron, recent studies have shown a role for Hedgehog, whose signaling demonstrates a dependence on primary cilia, in nociceptor sensitization. Here we report the expression of primary cilia in rat and mouse nociceptors, where they modulate mechanical nociceptive threshold, and contribute to inflammatory and neuropathic pain. When siRNA targeting Ift88 , a primary cilium-specific intra-flagellar transport (IFT) protein required for ciliary integrity, was administered by intrathecal injection, in the rat, it resulted in loss of Ift88 mRNA in DRG, and primary cilia in neuronal cell bodies, which was associated with an increase in mechanical nociceptive threshold, and abrogation of hyperalgesia induced by the pronociceptive inflammatory mediator, prostaglandin E 2 , and painful peripheral neuropathy induced by a neurotoxic chemotherapy drug, paclitaxel. To provide further support for the role of the primary cilium in nociceptor function we also administered siRNA for another IFT protein, Ift 52. Ift 52 siRNA results in loss of Ift 52 in DRG and abrogates paclitaxel-induced painful peripheral neuropathy. Attenuation of Hedgehog-induced hyperalgesia by Ift88 knockdown supports a role for the primary cilium in the hyperalgesia induced by Hedgehog, and attenuation of paclitaxel chemotherapy-induced neuropathy (CIPN) by cyclopamine, which attenuates Hedgehog signaling, suggests a role of Hedgehog in CIPN. Our findings support a role of nociceptor primary cilia in the control of mechanical nociceptive threshold and in inflammatory and neuropathic pain, the latter, at least in part, Hedgehog dependent.
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Macromolecular Structure of Linearly Arranged Eukaryotic Chromosomes. Int J Mol Sci 2022; 23:ijms23169503. [PMID: 36012767 PMCID: PMC9409004 DOI: 10.3390/ijms23169503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 08/05/2022] [Accepted: 08/11/2022] [Indexed: 11/22/2022] Open
Abstract
Eukaryotic chromosomes have not been visualized during the interphase. The fact that chromosomes cannot be seen during the interphase of the cell cycle does not mean that there are no means to make them visible. This work provides visual evidence that reversible permeabilization of the cell membrane followed by the regeneration of cell membranes allows getting a glimpse behind the nuclear curtain. Reversibly permeable eukaryotic cells have been used to synthesize nascent DNA, analyze the 5′-end of RNA primers, view individual replicons and visualize interphase chromosomes. Dextran T-150 in a slightly hypotonic buffer prevented cells from disruption. Upon reversal of permeabilization, the nucleus could be opened at any time during the interphase. A broad spectrum of a flexible chromatin folding pattern was revealed through a series of transient geometric forms of chromosomes. Linear attachment of chromosomes was visualized in several mammalian and lower eukaryotic cells. The linear connection of chromosomes is maintained throughout the cell cycle showing that rather than individual chromosomes, a linear array of chromosomes is the functional giant macromolecule. This study proves that not only the prokaryotic genome but also linearly attached eukaryotic chromosomes form a giant macromolecular unit.
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Actis Dato V, Benitez-Amaro A, Garcia E, Claudi L, Lhoëst MTL, Iborra A, Escola-Gil JC, Guerra JM, Samouillan V, Enrich C, Chiabrando G, Llorente-Cortés V. Targeting cholesteryl ester accumulation in the heart improves cardiac insulin response. Biomed Pharmacother 2022; 152:113270. [PMID: 35709652 DOI: 10.1016/j.biopha.2022.113270] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 06/02/2022] [Accepted: 06/06/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Antibodies against the P3 sequence (Gly1127-Cys1140) of LRP1 (anti-P3 Abs) specifically block cholesteryl ester (CE) accumulation in vascular cells. LRP1 is a key regulator of insulin receptor (InsR) trafficking in different cell types. The link between CE accumulation and the insulin response are largely unknown. Here, the effects of P3 peptide immunization on the alterations induced by a high-fat diet (HFD) in cardiac insulin response were evaluated. METHODS Irrelevant (IrP)- or P3 peptide-immunized rabbits were randomized into groups fed either HFD or normal chow. Cardiac lipid content was characterized by thin-layer chromatography, confocal microscopy, and electron microscopy. LRP1, InsR and glucose transporter type 4 (GLUT4) levels were determined in membranes and total lysates from rabbit heart. The interaction between InsR and LRP1 was analyzed by immunoprecipitation and confocal microscopy. Insulin signaling activity and glucose uptake were evaluated in HL-1 cells exposed to rabbit serum from the different groups. FINDINGS HFD reduces cardiac InsR and GLUT4 membrane levels and the interactions between LRP1/InsR. Targeting the P3 sequence on LRP1 through anti-P3 Abs specifically reduces CE accumulation in the heart independently of changes in the circulating lipid profile. This restores InsR and GLUT4 levels in cardiac membranes as well as the LRP1/InsR interactions of HFD-fed rabbits. In addition, anti-P3 Abs restores the insulin signaling cascade and glucose uptake in HL-1 cells exposed to hypercholesterolemic rabbit serum. INTERPRETATION LRP1-immunotargeting can block CE accumulation within the heart with specificity, selectivity, and efficacy, thereby improving the cardiac insulin response; this has important therapeutic implications for a wide range of cardiac diseases. FUNDING Fundació MARATÓ TV3: grant 101521-10, Instiuto de Salud Carlos III (ISCIII) and ERDFPI18/01584, Fundación BBVA Ayudas a Equipos de Investigación 2019. SECyT-UNC grants PROYECTOS CONSOLIDAR 2018-2021; FONCyT, Préstamo BID PICT grant 2015-0807 and grant 2017-4497.
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Affiliation(s)
- Virginia Actis Dato
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Córdoba, Argentina
| | - Aleyda Benitez-Amaro
- Institute of Biomedical Research of Barcelona (IIBB)-Spanish National Research Council (CSIC), Barcelona, Spain; Biomedical Research Institute Sant Pau (IIB Sant Pau), Barcelona, Spain
| | - Eduardo Garcia
- Institute of Biomedical Research of Barcelona (IIBB)-Spanish National Research Council (CSIC), Barcelona, Spain; Biomedical Research Institute Sant Pau (IIB Sant Pau), Barcelona, Spain
| | - Lene Claudi
- Institute of Biomedical Research of Barcelona (IIBB)-Spanish National Research Council (CSIC), Barcelona, Spain; Biomedical Research Institute Sant Pau (IIB Sant Pau), Barcelona, Spain
| | - Maria Teresa LaChica Lhoëst
- Institute of Biomedical Research of Barcelona (IIBB)-Spanish National Research Council (CSIC), Barcelona, Spain; Biomedical Research Institute Sant Pau (IIB Sant Pau), Barcelona, Spain
| | - Antoni Iborra
- SCAC, Universitat Autònoma de Barcelona (UAB), Bellaterra, Spain
| | - Joan Carles Escola-Gil
- Metabolic Basis of Cardiovascular Risk, Biomedical Research Institute Sant Pau (IIB Sant Pau), Hospital de la Santa Creu i Sant Pau. CIBER de Diabetes y enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona. Spain
| | - Jose Maria Guerra
- Department of Cardiology, Hospital de la Santa Creu i Sant Pau, Biomedical Research Institute Sant Pau (IIB Sant Pau), Universitat Autonoma de Barcelona, Barcelona, Spain; CIBERCV, Institute of Health Carlos III, 28029 Madrid, Spain
| | - Valerie Samouillan
- CIRIMAT, Université de Toulouse, Université Paul Sabatier, Equipe PHYPOL, 31062 Toulouse, France
| | - Carlos Enrich
- Unitat de Biologia Cel·lular, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain; Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Gustavo Chiabrando
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Córdoba, Argentina.
| | - Vicenta Llorente-Cortés
- Institute of Biomedical Research of Barcelona (IIBB)-Spanish National Research Council (CSIC), Barcelona, Spain; Biomedical Research Institute Sant Pau (IIB Sant Pau), Barcelona, Spain; CIBERCV, Institute of Health Carlos III, 28029 Madrid, Spain.
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Divakaruni AS, Jastroch M. A practical guide for the analysis, standardization and interpretation of oxygen consumption measurements. Nat Metab 2022; 4:978-994. [PMID: 35971004 PMCID: PMC9618452 DOI: 10.1038/s42255-022-00619-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 06/17/2022] [Indexed: 12/14/2022]
Abstract
Measurement of oxygen consumption is a powerful and uniquely informative experimental technique. It can help identify mitochondrial mechanisms of action following pharmacologic and genetic interventions, and characterize energy metabolism in physiology and disease. The conceptual and practical benefits of respirometry have made it a frontline technique to understand how mitochondrial function can interface with-and in some cases control-cell physiology. Nonetheless, an appreciation of the complexity and challenges involved with such measurements is required to avoid common experimental and analytical pitfalls. Here we provide a practical guide to oxygen consumption measurements covering the selection of experimental models and instrumentation, as well as recommendations for the collection, interpretation and normalization of data. These guidelines are provided with the intention of aiding experimental design and enhancing the overall reputability, transparency and reliability of oxygen consumption measurements.
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Affiliation(s)
- Ajit S Divakaruni
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
| | - Martin Jastroch
- Department of Molecular Biosciences, The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University, Stockholm, Sweden
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Interlaboratory evaluation of a digital holographic microscopy-based assay for label-free in vitro cytotoxicity testing of polymeric nanocarriers. Drug Deliv Transl Res 2022; 12:2207-2224. [PMID: 35799027 PMCID: PMC9263039 DOI: 10.1007/s13346-022-01207-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/25/2022] [Indexed: 01/19/2023]
Abstract
State-of-the-art in vitro test systems for nanomaterial toxicity assessment are based on dyes and several staining steps which can be affected by nanomaterial interference. Digital holographic microscopy (DHM), an interferometry-based variant of quantitative phase imaging (QPI), facilitates reliable proliferation quantification of native cell populations and the extraction of morphological features in a fast and label- and interference-free manner by biophysical parameters. DHM therefore has been identified as versatile tool for cytotoxicity testing in biomedical nanotechnology. In a comparative study performed at two collaborating laboratories, we investigated the interlaboratory variability and performance of DHM in nanomaterial toxicity testing, utilizing complementary standard operating procedures (SOPs). Two identical custom-built off-axis DHM systems, developed for usage in biomedical laboratories, equipped with stage-top incubation chambers were applied at different locations in Europe. Temporal dry mass development, 12-h dry mass increments and morphology changes of A549 human lung epithelial cell populations upon incubation with two variants of poly(alkyl cyanoacrylate) (PACA) nanoparticles were observed in comparison to digitonin and cell culture medium controls. Digitonin as cytotoxicity control, as well as empty and cabazitaxel-loaded PACA nanocarriers, similarly impacted 12-h dry mass development and increments as well as morphology of A549 cells at both participating laboratories. The obtained DHM data reflected the cytotoxic potential of the tested nanomaterials and are in agreement with corresponding literature on biophysical and chemical assays. Our results confirm DHM as label-free cytotoxicity assay for polymeric nanocarriers as well as the repeatability and reproducibility of the technology. In summary, the evaluated DHM assay could be efficiently implemented at different locations and facilitates interlaboratory in vitro toxicity testing of nanoparticles with prospects for application in regulatory science.
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Tang B, Liu BH, Liu ZY, Luo MY, Shi XH, Pang DW. Quantum Dots with a Compact Amphiphilic Zwitterionic Coating. ACS APPLIED MATERIALS & INTERFACES 2022; 14:28097-28104. [PMID: 35686447 DOI: 10.1021/acsami.2c04438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Generally speaking, it is difficult to keep nanomaterials encapsulated in amphiphilic polymers like octylamine-grafted poly(acrylic acid) (OPA) compact in coating-layer, with a small hydrodynamic size. Here, we prepared stable hydrophilic quantum dots (QDs) via encapsulation in ∼3 nm-long amphiphilic and zwitterionic (AZ) molecules. After encapsulation with AZ molecules, the coated QDs are only 2.1 nm thicker in coating, instead of 5.4 nm with OPA. Meanwhile, the hydrodynamic sizes of CdSe/CdS, ZnCdSeS, ZnCdSe/ZnS, and CdSe/ZnS QDs encapsulated in AZ molecules (AZ-QDs) are less than 15 nm, and 6-7 nm smaller than those of QDs in OPA (OPA-QDs). Notably, both extracellular and intracellular nonspecific binding of AZ-QDs is approximately 100-folds lower than that of OPA-QDs.
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Affiliation(s)
- Bo Tang
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China
| | - Bing-Hua Liu
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China
| | - Zhen-Ya Liu
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China
| | - Meng-Yao Luo
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China
| | - Xue-Hui Shi
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Frontiers Science Center for New Organic Matter, Research Center for Analytical Sciences, College of Chemistry, Frontiers Science Center for Cell Responses, Nankai University, Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300071, P. R. China
| | - Dai-Wen Pang
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Frontiers Science Center for New Organic Matter, Research Center for Analytical Sciences, College of Chemistry, Frontiers Science Center for Cell Responses, Nankai University, Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300071, P. R. China
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Van Hoeck J, Braeckmans K, De Smedt SC, Raemdonck K. Non-viral siRNA delivery to T cells: Challenges and opportunities in cancer immunotherapy. Biomaterials 2022; 286:121510. [DOI: 10.1016/j.biomaterials.2022.121510] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 03/17/2022] [Accepted: 04/01/2022] [Indexed: 12/12/2022]
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12
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Lei XH, Bochner BR. Optimization of cell permeabilization in electron flow based mitochondrial function assays. Free Radic Biol Med 2021; 177:48-57. [PMID: 34656699 DOI: 10.1016/j.freeradbiomed.2021.10.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 10/05/2021] [Accepted: 10/13/2021] [Indexed: 12/21/2022]
Abstract
Permeable cell models have contributed much to the progress in mitochondrial research. Optimization of permeabilization is required to make the cell's plasma membrane permeable to small molecules while keeping the intracellular organelles and their membranes intact and fully functional. Here we report our assessment and optimization of commonly used permeabilizing agents including different saponin preparations, digitonin, and recombinant perfringolysin O employing a new electron flow based mitochondrial assay technology that utilizes a colorimetric redox dye. The results of this study provide guidance in optimizing the conditions for mitochondrial function assays with permeabilized cells using the novel redox dye-based format.
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Affiliation(s)
- Xiang-He Lei
- Biolog, Inc., 21124 Cabot Blvd., Hayward, CA, 94545, USA
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Yang K, Doan MT, Stiles L, Divakaruni AS. Measuring CPT-1-mediated respiration in permeabilized cells and isolated mitochondria. STAR Protoc 2021; 2:100687. [PMID: 34401773 PMCID: PMC8348308 DOI: 10.1016/j.xpro.2021.100687] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Carnitine palmitoyltransferase-1 (CPT-1) is a rate-controlling enzyme for long-chain fatty acid oxidation. This manuscript provides protocols for measuring CPT-1-mediated respiration in permeabilized, adherent cell monolayers and mitochondria freshly isolated from tissue, along with examples to assess the potency and specificity of interventions targeting CPT-1. Strengths of the approach include ease, speed, and breadth of analysis, whereas drawbacks include loss of physiological regulation in reductionist systems and indirect assessment of CPT-1 enzymatic activity. For complete details on the use and execution of this protocol, please refer to Divakaruni et al. (2018). Protocol for pathway-specific respiration using Seahorse XF Analyzer Detailed steps for both isolated mitochondria and plasma membrane-permeabilized cells Examples given for specific inhibition of long-chain fatty acid oxidation
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Affiliation(s)
- Krista Yang
- Department of Molecular and Medical Pharmacology, UCLA David Geffen School of Medicine, Los Angeles, CA 90095, USA
| | - Mary T Doan
- Department of Molecular and Medical Pharmacology, UCLA David Geffen School of Medicine, Los Angeles, CA 90095, USA
| | - Linsey Stiles
- Department of Molecular and Medical Pharmacology, UCLA David Geffen School of Medicine, Los Angeles, CA 90095, USA.,Department of Medicine, UCLA David Geffen School of Medicine, Los Angeles, CA 90095, USA
| | - Ajit S Divakaruni
- Department of Molecular and Medical Pharmacology, UCLA David Geffen School of Medicine, Los Angeles, CA 90095, USA
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14
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Pereira Vatanabe I, Peron R, Mantellatto Grigoli M, Pelucchi S, De Cesare G, Magalhães T, Manzine PR, Figueredo Balthazar ML, Di Luca M, Marcello E, Cominetti MR. ADAM10 Plasma and CSF Levels Are Increased in Mild Alzheimer's Disease. Int J Mol Sci 2021; 22:ijms22052416. [PMID: 33670873 PMCID: PMC7957802 DOI: 10.3390/ijms22052416] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 02/24/2021] [Accepted: 02/25/2021] [Indexed: 01/03/2023] Open
Abstract
ADAM10 is the main α-secretase that participates in the non-amyloidogenic cleavage of amyloid precursor protein (APP) in neurons, inhibiting the production of β-amyloid peptide (Aβ) in Alzheimer’s disease (AD). Strong recent evidence indicates the importance of the localization of ADAM10 for its activity as a protease. In this study, we investigated ADAM10 activity in plasma and CSF samples of patients with amnestic mild cognitive impairment (aMCI) and mild AD compared with cognitively healthy controls. Our results indicated that plasma levels of soluble ADAM10 were significantly increased in the mild AD group, and that in these samples the protease was inactive, as determined by activity assays. The same results were observed in CSF samples, indicating that the increased plasma ADAM10 levels reflect the levels found in the central nervous system. In SH-SY5Y neuroblastoma cells, ADAM10 achieves its major protease activity in the fraction obtained from plasma membrane lysis, where the mature form of the enzyme is detected, confirming the importance of ADAM10 localization for its activity. Taken together, our results demonstrate the potential of plasma ADAM10 to act as a biomarker for AD, highlighting its advantages as a less invasive, easier, faster, and lower-cost processing procedure, compared to existing biomarkers.
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Affiliation(s)
- Izabela Pereira Vatanabe
- Department of Gerontology, Federal University of São Carlos, São Carlos 13565-905, Brazil; (I.P.V.); (R.P.); (M.M.G.); (P.R.M.)
| | - Rafaela Peron
- Department of Gerontology, Federal University of São Carlos, São Carlos 13565-905, Brazil; (I.P.V.); (R.P.); (M.M.G.); (P.R.M.)
| | - Marina Mantellatto Grigoli
- Department of Gerontology, Federal University of São Carlos, São Carlos 13565-905, Brazil; (I.P.V.); (R.P.); (M.M.G.); (P.R.M.)
| | - Silvia Pelucchi
- Department of Pharmacological and Biomolecular Sciences, Universitá Degli Studi di Milano, 20133 Milan, Italy; (S.P.); (G.D.C.); (M.D.L.)
| | - Giulia De Cesare
- Department of Pharmacological and Biomolecular Sciences, Universitá Degli Studi di Milano, 20133 Milan, Italy; (S.P.); (G.D.C.); (M.D.L.)
| | - Thamires Magalhães
- Department of Neurology, University of Campinas, Campinas 13083-887, Brazil; (T.M.); (M.L.F.B.)
| | - Patricia Regina Manzine
- Department of Gerontology, Federal University of São Carlos, São Carlos 13565-905, Brazil; (I.P.V.); (R.P.); (M.M.G.); (P.R.M.)
| | | | - Monica Di Luca
- Department of Pharmacological and Biomolecular Sciences, Universitá Degli Studi di Milano, 20133 Milan, Italy; (S.P.); (G.D.C.); (M.D.L.)
| | - Elena Marcello
- Department of Pharmacological and Biomolecular Sciences, Universitá Degli Studi di Milano, 20133 Milan, Italy; (S.P.); (G.D.C.); (M.D.L.)
- Correspondence: (E.M.); (M.R.C.); Tel.: +39-02-5031-8314 (E.M.); +55-16-3306-6663 (M.R.C.)
| | - Marcia Regina Cominetti
- Department of Gerontology, Federal University of São Carlos, São Carlos 13565-905, Brazil; (I.P.V.); (R.P.); (M.M.G.); (P.R.M.)
- Correspondence: (E.M.); (M.R.C.); Tel.: +39-02-5031-8314 (E.M.); +55-16-3306-6663 (M.R.C.)
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15
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Ramalingam N, Dettmer U. Temperature is a key determinant of alpha- and beta-synuclein membrane interactions in neurons. J Biol Chem 2021; 296:100271. [PMID: 33428933 PMCID: PMC7949061 DOI: 10.1016/j.jbc.2021.100271] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 01/06/2021] [Accepted: 01/07/2021] [Indexed: 02/02/2023] Open
Abstract
Aggregation of α-synuclein (αS) leads to the hallmark neuropathology of Parkinson's disease (PD) and related synucleinopathies. αS has been described to exist in both cytosolic and membrane-associated forms, the relative abundance of which has remained unsettled. To study αS under the most relevant conditions by a quantitative method, we cultured and matured rodent primary cortical neurons for >17 days and determined αS cytosol:membrane distribution via centrifugation-free sequential extractions based on the weak ionic detergent digitonin. We noticed that at lower temperatures (4 °C or room temperature), αS was largely membrane-associated. At 37 °C, however, αS solubility was markedly increased. In contrast, the extraction of control proteins (GAPDH, cytosolic; calnexin, membrane) was not affected by temperature. When we compared the relative distribution of the synuclein homologs αS and β-synuclein (βS) under various conditions that differed in temperature and digitonin concentration (200-1200 μg/ml), we consistently found αS to be more membrane-associated than βS. Both proteins, however, exhibited temperature-dependent membrane binding. Under the most relevant conditions (37 °C and 800 μg/ml digitonin, i.e., the lowest digitonin concentration that extracted cytosolic GAPDH to near completion), cytosolic distribution was 49.8% ± 9.0% for αS and 63.6% ± 6.6% for βS. PD-linked αS A30P was found to be largely cytosolic, confirming previous studies that had used different methods. Our work highlights the dynamic nature of cellular synuclein behavior and has important implications for protein-biochemical and cell-biological studies of αS proteostasis, such as testing the effects of genetic and pharmacological manipulations.
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Affiliation(s)
- Nagendran Ramalingam
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA.
| | - Ulf Dettmer
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA.
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16
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Dawid C, Weber D, Musiol E, Janas V, Baur S, Lang R, Fromme T. Comparative assessment of purified saponins as permeabilization agents during respirometry. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1861:148251. [PMID: 32598881 DOI: 10.1016/j.bbabio.2020.148251] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 05/26/2020] [Accepted: 06/12/2020] [Indexed: 01/15/2023]
Abstract
Saponins are a diverse group of secondary plant metabolites, some of which display hemolytic toxicity due to plasma membrane permeabilization. This feature is employed in biological applications for transferring hydrophilic molecules through cell membranes. Widely used commercial saponins include digitonin and saponins from soap tree bark, both of which constitute complex mixtures of little definition. We assessed the permeabilization power of pure saponins towards cellular membranes in an effort to detect novel properties and to improve existing applications. In a respirometric assay, we characterized half-maximal permeabilization of the plasma membrane for different metabolites, of the mitochondrial outer membrane for cytochrome C and the full solubilization of mitochondrial inner membrane protein complexes. Beyond the complete list as repository for the field, we highlight several findings with direct applicability. First, we identified and validated α-chaconine as alternative permeabilization agent in respirometric assays of cultured cells and isolated synaptosomes, superior to digitonin in its tolerability for mitochondria. Second, we identified glycyrrhizic acid to form exceptionally small pores impermeable for adenosine diphosphate. Third, in a concentration dependent manner, tomatine proved to be able to selectively permeabilize the mitochondrial outer, but not inner membrane, allowing for novel states in which to determine cytochrome C oxidase activity. In summary, we provide a list of the permeabilization properties of 18 pure saponins. The identification of two saponins, namely tomatine and chaconine, with direct usability in improved or novel cell biological applications within this small subgroup demonstrates the tremendous potential for further functional screening of pure saponins.
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Affiliation(s)
- Corinna Dawid
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Freising, Germany
| | - Daniela Weber
- Chair of Molecular Nutritional Medicine, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Eva Musiol
- Chair of Molecular Nutritional Medicine, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Vanessa Janas
- Chair of Molecular Nutritional Medicine, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Sebastian Baur
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Freising, Germany
| | - Roman Lang
- Chair of Food Chemistry and Molecular Sensory Science, Technical University of Munich, Freising, Germany
| | - Tobias Fromme
- Chair of Molecular Nutritional Medicine, TUM School of Life Sciences, Technical University of Munich, Freising, Germany; EKFZ - Else Kröner-Fresenius Center for Nutritional Medicine, Technical University of Munich, Freising, Germany.
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17
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Crawford CL, Dalecki AG, Perez MD, Schaaf K, Wolschendorf F, Kutsch O. A copper-dependent compound restores ampicillin sensitivity in multidrug-resistant Staphylococcus aureus. Sci Rep 2020; 10:8955. [PMID: 32488067 PMCID: PMC7265353 DOI: 10.1038/s41598-020-65978-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 03/09/2020] [Indexed: 12/11/2022] Open
Abstract
Multi-drug resistant Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA), has become a worldwide, major health care problem. While initially restricted to clinical settings, drug resistant S. aureus is now one of the key causative agents of community-acquired infections. We have previously demonstrated that copper dependent inhibitors (CDIs), a class of antibiotics that are only active in the presence of copper ions, are effective bactericidal agents against MRSA. A second-generation CDI, APT-6K, exerted bactericidal activity at nanomolar concentrations. At sub-bactericidal concentrations, it effectively synergized with ampicillin to reverse drug resistance in multiple MRSA strains. APT-6K had a favorable therapeutic index when tested on eukaryotic cells (TI: > 30) and, unlike some previously reported CDIs, did not affect mitochondrial activity. These results further establish inhibitors that are activated by the binding of transition metal ions as a promising class of antibiotics, and for the first time, describe their ability to reverse existing drug resistance against clinically relevant antibiotics.
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Affiliation(s)
- Cameron L Crawford
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Alex G Dalecki
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Mildred D Perez
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Kaitlyn Schaaf
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Frank Wolschendorf
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Olaf Kutsch
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA.
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18
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Lerchundi R, Huang N, Rose CR. Quantitative Imaging of Changes in Astrocytic and Neuronal Adenosine Triphosphate Using Two Different Variants of ATeam. Front Cell Neurosci 2020; 14:80. [PMID: 32372916 PMCID: PMC7186936 DOI: 10.3389/fncel.2020.00080] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 03/19/2020] [Indexed: 12/25/2022] Open
Abstract
Genetically encoded nanosensors such as the FRET-based adenosine triphosphate (ATP) sensor ATeam enable the measurement of changes in ATP levels inside cells, promoting our understanding of metabolic interactions between astrocytes and neurons. The sensors are usually well characterized in vitro but display altered properties when expressed inside cells, precluding a meaningful conversion of changes in FRET ratios into changes in intracellular ATP concentrations ([ATP]) on the basis of their in vitro properties. Here, we present an experimental strategy for the intracellular calibration of two different variants of ATeam in organotypic tissue slice culture of the mouse brain. After cell-type-specific expression of the sensors in astrocytes or neurons, slices were first perfused with a saline containing the saponin β-escin to permeabilize plasma membranes for ATP. Next, cells were depleted of ATP by perfusion with ATP-free saline containing metabolic inhibitors. Finally, ATP was re-added at defined concentrations and resulting changes in the FRET ratio recorded. When employing this protocol, ATeam1.03 expressed in astrocytes reliably responds to changes in [ATP], exhibiting an apparent KD of 9.4 mM. The high-affinity sensor ATeam1.03YEMK displayed a significantly lower intracellular KD of 2.7 mM. On the basis of these calibrations, we found that induction of a recurrent neuronal network activity resulted in an initial transient increase in astrocytic [ATP] by ~0.12 mM as detected by ATeam1.03YEMK, a result confirmed using ATeam1.03. In neurons, in contrast, [ATP] immediately started to decline upon initiation of a network activity, amounting to a decrease by an average of 0.29 mM after 2 min. Taken together, our results demonstrate that ATeam1.03YEMK and ATeam1.03 display a significant increase in their apparent KD when expressed inside cells as compared with in vitro. Moreover, they show that both ATeam variants enable the quantitative detection of changes of astrocytic and neuronal [ATP] in the physiological range. ATeam1.03YEMK, however, seems preferable because its KD is close to baseline ATP levels. Finally, our data support the idea that synchronized neuronal activity initially stimulates the generation of ATP in astrocytes, presumably through increased glycolysis, whereas ATP levels in neurons decline.
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Affiliation(s)
- Rodrigo Lerchundi
- Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Na Huang
- Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Christine R Rose
- Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
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19
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Han Z, Sarkar S, Smith AM. Zwitterion and Oligo(ethylene glycol) Synergy Minimizes Nonspecific Binding of Compact Quantum Dots. ACS NANO 2020; 14:3227-3241. [PMID: 32105448 PMCID: PMC7321848 DOI: 10.1021/acsnano.9b08658] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Quantum dots (QDs) are a class of fluorescent nanocrystals in development as labels for molecular imaging in cells and tissues. Recently, coatings for quantum dots based on multidentate polymers have improved labeling performance in a range of bioanalytical applications, primarily due to reduced probe hydrodynamic size. Now, an ongoing challenge is to eliminate nonspecific binding between these small probes and cellular components that mask specifically labeled molecules. Here, we describe insights into controlling and minimizing intermolecular interactions governing nonspecific binding using multidentate polymers with tunable hydrophilic functional groups that are cationic, anionic, zwitterionic (ZW), or nonionic (oligoethylene glycol; OEG). By fixing surface-binding groups and polymer length, coated colloids have similar sizes but diverse physicochemical properties. We measure binding to globular proteins, fixed cells, and living cells and observe a substantial improvement in nonspecific binding resistance when surfaces are functionalized with a combination of ZW and OEG. The independent underlying effects of counterion adsorption and flexibility appear to synergistically resist adsorption when combined, particularly for fixed cells enriched in both charged and hydrophobic moieties. We further show that ZW-OEG QDs are stable under diverse conditions and can be self-assembled with antibodies to specifically label surface antigens on living cells and cytoplasmic proteins in fixed cells. This surface engineering strategy can be adopted across the diverse range of colloidal materials currently in use and in development for biomedical applications to optimize their molecular labeling specificity.
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Affiliation(s)
- Zhiyuan Han
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Holonyak Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Suresh Sarkar
- Holonyak Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Andrew M Smith
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Holonyak Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Cancer Center at Illinois, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Carle Illinois College of Medicine, Urbana, Illinois 61801, United States
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20
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Chen Y, Wang H, Shen J, Deng R, Yao X, Guo Q, Lu A, Sun B, Zhang Y, Meng G. Gasdermin D Drives the Nonexosomal Secretion of Galectin-3, an Insulin Signal Antagonist. THE JOURNAL OF IMMUNOLOGY 2019; 203:2712-2723. [DOI: 10.4049/jimmunol.1900212] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 09/17/2019] [Indexed: 12/14/2022]
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21
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Di Z, Zhao J, Chu H, Xue W, Zhao Y, Li L. An Acidic-Microenvironment-Driven DNA Nanomachine Enables Specific ATP Imaging in the Extracellular Milieu of Tumor. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1901885. [PMID: 31222950 DOI: 10.1002/adma.201901885] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 05/29/2019] [Indexed: 06/09/2023]
Abstract
Extracellular ATP is an emerging target for cancer treatment because it is a key messenger for shaping the tumor microenvironment (TME) and regulating tumor progression. However, it remains a great challenge to design biochemical probes for targeted imaging of extracellular ATP in the TME. A TME-driven DNA nanomachine (Apt-LIP) that permits spatially controlled imaging of ATP in the extracellular milieu of tumors with ultrahigh signal-to-background ratio is reported. It operates in response to the mild acidity in the TME with the pH (low) insertion peptide (pHLIP) module, thus allowing the specific anchoring of the structure-switching signaling aptamer unit to the membrane of tumor cells for "off-on" fluorescence imaging of the extracellular ATP. Apt-LIP allows for acidity driven visualization of different extracellular concentrations of exogenous ATP, as well as the monitoring of endogenous ATP release from cells. Furthermore, it is demonstrated that Apt-LIP represents a promising platform for the specific imaging of the extracellular ATP in both primary and metastatic tumors. Ultimately, since diverse aptamers are obtained through in vitro selection, this design strategy can be further applied for precise detection of various extracellular targets in the TME.
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Affiliation(s)
- Zhenghan Di
- 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
| | - Jian Zhao
- 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
| | - Hongqian Chu
- 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
| | - Wenting Xue
- 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
| | - Yuliang Zhao
- 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
| | - Lele Li
- 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
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22
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Iannotti MJ, MacArthur R, Jones R, Tao D, Singeç I, Michael S, Inglese J. Detecting Secretory Proteins by Acoustic Droplet Ejection in Multiplexed High-Throughput Applications. ACS Chem Biol 2019; 14:497-505. [PMID: 30699290 DOI: 10.1021/acschembio.9b00001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Nearly one-third of the encoded proteome is comprised of secretory proteins that enable communication between cells and organ systems, playing a ubiquitous role in human health and disease. High-throughput detection of secreted proteins would enhance efforts to identify therapies for secretion-related diseases. Using the Z mutant of alpha-1 antitrypsin as a human secretory model, we have developed 1536-well high-throughput screening assays that utilize acoustic droplet ejection to transfer nanoliter volumes of sample for protein quantification. Among them, the acoustic reverse phase protein array (acoustic RPPA) is a multiplexable, low-cost immunodetection technology for native, endogenously secreted proteins from physiologically relevant model systems like stem cells that is compatible with plate-based instrumentation. Parallel assay profiling with the LOPAC1280 chemical library validated performance and orthogonality between a secreted bioluminescent reporter and acoustic RPPA method by consistently identifying secretory modulators with comparable concentration response relationships. Here, we introduce a robust, multiplexed drug discovery platform coupling extracellular protein quantification by acoustic RPPA with intracellular and cytotoxicity analyses from single wells, demonstrating proof-of-principle applications for human induced pluripotent stem cell-derived hepatocytes.
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Affiliation(s)
- Michael J. Iannotti
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20850, United States
| | - Ryan MacArthur
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20850, United States
| | - Richard Jones
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20850, United States
| | - Dingyin Tao
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20850, United States
| | - Ilyas Singeç
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20850, United States
| | - Sam Michael
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20850, United States
| | - James Inglese
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20850, United States
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23
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Rossi AM, Taylor CW. IP3 receptors – lessons from analyses ex cellula. J Cell Sci 2018; 132:132/4/jcs222463. [DOI: 10.1242/jcs.222463] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
ABSTRACT
Inositol 1,4,5-trisphosphate receptors (IP3Rs) are widely expressed intracellular channels that release Ca2+ from the endoplasmic reticulum (ER). We review how studies of IP3Rs removed from their intracellular environment (‘ex cellula’), alongside similar analyses of ryanodine receptors, have contributed to understanding IP3R behaviour. Analyses of permeabilized cells have demonstrated that the ER is the major intracellular Ca2+ store, and that IP3 stimulates Ca2+ release from this store. Radioligand binding confirmed that the 4,5-phosphates of IP3 are essential for activating IP3Rs, and facilitated IP3R purification and cloning, which paved the way for structural analyses. Reconstitution of IP3Rs into lipid bilayers and patch-clamp recording from the nuclear envelope have established that IP3Rs have a large conductance and select weakly between Ca2+ and other cations. Structural analyses are now revealing how IP3 binding to the N-terminus of the tetrameric IP3R opens the pore ∼7 nm away from the IP3-binding core (IBC). Communication between the IBC and pore passes through a nexus of interleaved domains contributed by structures associated with the pore and cytosolic domains, which together contribute to a Ca2+-binding site. These structural analyses provide evidence to support the suggestion that IP3 gates IP3Rs by first stimulating Ca2+ binding, which leads to pore opening and Ca2+ release.
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Affiliation(s)
- Ana M. Rossi
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
| | - Colin W. Taylor
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
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24
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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: 412] [Impact Index Per Article: 68.7] [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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25
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Chen H, McFaul C, Titushkin I, Cho M, Lee R. Surfactant Copolymer Annealing of Chemically Permeabilized Cell Membranes. REGENERATIVE ENGINEERING AND TRANSLATIONAL MEDICINE 2018; 4:1-10. [PMID: 30906849 DOI: 10.1007/s40883-017-0044-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Structural breakdown of the cell membrane is a primary mediator in trauma induced tissue necrosis. When membrane disruption exceeds intrinsic membrane sealing processes, biocompatible multi-block amphiphilic copolymer surfactants such as Poloxamer 188 (P188) have been found to be effective in catalyze or augment sealing. Although in living cells copolymer induced sealing of membrane defects has been detected by changes in membrane transport properties, it has not been directly imaged. In this project we used Atomic force microscopy (AFM) to directly image saponin permeabilized and poloxamer sealed plasma membranes of monolayer cultured MDCK and 3T3 fibroblasts. AFM image analysis resulted in the density and diameter ranges for membrane indentations per 5×5 μm area. For control, saponin lysed, and P188 treatment of saponin lysed membranes, the supra-threshold indentation density was 3.6 ± 2.8, 13.8 ± 6.7, and 4.9 ± 3.3/cell, respectively. These results indicated that P188 catalyzed reduction in size of AFM indentations which correlated with increase cell survival. This evidence confirm that biocompatible surfactant P188 augment natural cell membrane sealing capability when intrinsic processes are incapable alone.
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Affiliation(s)
- Hongfeng Chen
- Department of Surgery, University of Chicago, Chicago, IL, USA, 60637
| | - Colin McFaul
- Department of Surgery, University of Chicago, Chicago, IL, USA, 60637
| | - Igor Titushkin
- Department of Surgery, University of Illinois at Chicago, Chicago IL, USA, 60605
| | - Michael Cho
- Department of Surgery, University of Illinois at Chicago, Chicago IL, USA, 60605
| | - Raphael Lee
- Department of Surgery, University of Chicago, Chicago, IL, USA, 60637
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Biwer LA, Good ME, Hong K, Patel RK, Agrawal N, Looft-Wilson R, Sonkusare SK, Isakson BE. Non-Endoplasmic Reticulum-Based Calr (Calreticulin) Can Coordinate Heterocellular Calcium Signaling and Vascular Function. Arterioscler Thromb Vasc Biol 2018; 38:120-130. [PMID: 29122814 PMCID: PMC5746467 DOI: 10.1161/atvbaha.117.309886] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 10/25/2017] [Indexed: 11/16/2022]
Abstract
OBJECTIVE In resistance arteries, endothelial cell (EC) extensions can make contact with smooth muscle cells, forming myoendothelial junction at holes in the internal elastic lamina (HIEL). At these HIEL, calcium signaling is tightly regulated. Because Calr (calreticulin) can buffer ≈50% of endoplasmic reticulum calcium and is expressed throughout IEL holes in small arteries, the only place where myoendothelial junctions form, we investigated the effect of EC-specific Calr deletion on calcium signaling and vascular function. APPROACH AND RESULTS We found Calr expressed in nearly every IEL hole in third-order mesenteric arteries, but not other ER markers. Because of this, we generated an EC-specific, tamoxifen inducible, Calr knockout mouse (EC Calr Δ/Δ). Using this mouse, we tested third-order mesenteric arteries for changes in calcium events at HIEL and vascular reactivity after application of CCh (carbachol) or PE (phenylephrine). We found that arteries from EC Calr Δ/Δ mice stimulated with CCh had unchanged activity of calcium signals and vasodilation; however, the same arteries were unable to increase calcium events at HIEL in response to PE. This resulted in significantly increased vasoconstriction to PE, presumably because of inhibited negative feedback. In line with these observations, the EC Calr Δ/Δ had increased blood pressure. Comparison of ER calcium in arteries and use of an ER-specific GCaMP indicator in vitro revealed no observable difference in ER calcium with Calr knockout. Using selective detergent permeabilization of the artery and inhibition of Calr translocation, we found that the observed Calr at HIEL may not be within the ER. CONCLUSIONS Our data suggest that Calr specifically at HIEL may act in a non-ER dependent manner to regulate arteriolar heterocellular communication and blood pressure.
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Affiliation(s)
- Lauren A Biwer
- From the Robert M. Berne Cardiovascular Research Center (L.A.B., M.E.G., K.H., R.K.P., S.K.S., B.E.I.) and Department of Molecular Physiology and Biophysics (L.A.B., S.K.S., B.E.I.), University of Virginia School of Medicine, Charlottesville; and Department of Kinesiology, College of William and Mary, Williamsburg, VA (N.A., R.L.-W.)
| | - Miranda E Good
- From the Robert M. Berne Cardiovascular Research Center (L.A.B., M.E.G., K.H., R.K.P., S.K.S., B.E.I.) and Department of Molecular Physiology and Biophysics (L.A.B., S.K.S., B.E.I.), University of Virginia School of Medicine, Charlottesville; and Department of Kinesiology, College of William and Mary, Williamsburg, VA (N.A., R.L.-W.)
| | - Kwangseok Hong
- From the Robert M. Berne Cardiovascular Research Center (L.A.B., M.E.G., K.H., R.K.P., S.K.S., B.E.I.) and Department of Molecular Physiology and Biophysics (L.A.B., S.K.S., B.E.I.), University of Virginia School of Medicine, Charlottesville; and Department of Kinesiology, College of William and Mary, Williamsburg, VA (N.A., R.L.-W.)
| | - Rahul K Patel
- From the Robert M. Berne Cardiovascular Research Center (L.A.B., M.E.G., K.H., R.K.P., S.K.S., B.E.I.) and Department of Molecular Physiology and Biophysics (L.A.B., S.K.S., B.E.I.), University of Virginia School of Medicine, Charlottesville; and Department of Kinesiology, College of William and Mary, Williamsburg, VA (N.A., R.L.-W.)
| | - Neha Agrawal
- From the Robert M. Berne Cardiovascular Research Center (L.A.B., M.E.G., K.H., R.K.P., S.K.S., B.E.I.) and Department of Molecular Physiology and Biophysics (L.A.B., S.K.S., B.E.I.), University of Virginia School of Medicine, Charlottesville; and Department of Kinesiology, College of William and Mary, Williamsburg, VA (N.A., R.L.-W.)
| | - Robin Looft-Wilson
- From the Robert M. Berne Cardiovascular Research Center (L.A.B., M.E.G., K.H., R.K.P., S.K.S., B.E.I.) and Department of Molecular Physiology and Biophysics (L.A.B., S.K.S., B.E.I.), University of Virginia School of Medicine, Charlottesville; and Department of Kinesiology, College of William and Mary, Williamsburg, VA (N.A., R.L.-W.)
| | - Swapnil K Sonkusare
- From the Robert M. Berne Cardiovascular Research Center (L.A.B., M.E.G., K.H., R.K.P., S.K.S., B.E.I.) and Department of Molecular Physiology and Biophysics (L.A.B., S.K.S., B.E.I.), University of Virginia School of Medicine, Charlottesville; and Department of Kinesiology, College of William and Mary, Williamsburg, VA (N.A., R.L.-W.)
| | - Brant E Isakson
- From the Robert M. Berne Cardiovascular Research Center (L.A.B., M.E.G., K.H., R.K.P., S.K.S., B.E.I.) and Department of Molecular Physiology and Biophysics (L.A.B., S.K.S., B.E.I.), University of Virginia School of Medicine, Charlottesville; and Department of Kinesiology, College of William and Mary, Williamsburg, VA (N.A., R.L.-W.).
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27
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Divakaruni AS, Andreyev AY, Rogers GW, Murphy AN. In situ measurements of mitochondrial matrix enzyme activities using plasma and mitochondrial membrane permeabilization agents. Anal Biochem 2017; 552:60-65. [PMID: 28987935 DOI: 10.1016/j.ab.2017.09.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 09/27/2017] [Accepted: 09/29/2017] [Indexed: 12/16/2022]
Abstract
Activities of enzymes localized to the mitochondrial matrix of mammalian cells are often critical regulatory steps in cellular metabolism. As such, measurement of matrix enzyme activities in response to genetic modifications or drug interventions is often desired. However, measurements in intact cells are often hampered by the presence of other isozymes in the cytoplasm as well as the inability to deliver enzyme substrates across cellular membranes. Classic approaches to liberate matrix enzymes utilize harsh treatments that disrupt intracellular architecture or require significant starting material to allow mitochondrial isolation prior to sample extraction. We describe a method using permeabilization reagents for both the plasma and mitochondrial membranes to allow in situ measurement of matrix enzyme activities. It is applied to adherent cell monolayers in 96-well plates treated with perfringolysin O to permeabilize the plasma membrane and alamethicin to permeabilize the mitochondrial inner membrane. We present three examples validated with inhibitor sensitivity: (i) Complex I-mediated oxygen consumption driven by NADH, (ii) ATP hydrolysis by the F1FO complex measuring pH changes in an Agilent Seahorse XF Analyzer, and (iii) Mitochondrial glutaminase (GLS1) activity in a coupled reaction monitoring NADH fluorescence in a plate reader.
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Affiliation(s)
- Ajit S Divakaruni
- University of California, Los Angeles, Department of Molecular and Medical Pharmacology, 650 Charles E. Young Dr. South, 23-305 Center for Health Sciences, Los Angeles, CA 90095-1735, United States.
| | - Alexander Y Andreyev
- University of California, San Diego, Department of Pharmacology, 9500 Gilman Drive #0636, La Jolla, CA 92093, United States
| | - George W Rogers
- Agilent Technologies, 5301 Stevens Creek Blvd, Santa Clara, CA 95051, United States
| | - Anne N Murphy
- University of California, San Diego, Department of Pharmacology, 9500 Gilman Drive #0636, La Jolla, CA 92093, United States
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Analysis of mitochondrial metabolism in situ: Combining stable isotope labeling with selective permeabilization. Metab Eng 2017; 43:147-155. [DOI: 10.1016/j.ymben.2016.12.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 12/08/2016] [Accepted: 12/09/2016] [Indexed: 12/25/2022]
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Bora de Oliveira K, Spencer D, Barton C, Agarwal N. Site-specific monitoring of N-Glycosylation profiles of a CTLA4-Fc-fusion protein from the secretory pathway to the extracellular environment. Biotechnol Bioeng 2017; 114:1550-1560. [PMID: 28186328 DOI: 10.1002/bit.26266] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 01/31/2017] [Accepted: 02/06/2017] [Indexed: 01/18/2023]
Abstract
Glycosylation often plays a key role in the safety and efficacy of therapeutic proteins to patients, thus underlying the need for consistent control of this important post-translational modification during biologics production. In this study, we profiled the site-specific evolution of N-glycans on a CTLA4-Fc-fusion protein, from the intracellular secretory pathway to the conditioned medium (CM) in fed-batch cell culture. For this, we developed an approach that combined sub-cellular fractionation with liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses. The study revealed that there was a significant amount of heterogeneity in the glycans displayed amongst the three distinct N-glycosylation sites. Furthermore, 54-60% of the intracellular protein was characterized by Man8 and Man9 glycans on day 10, when the cell density peaks, indicative of a significant bottleneck between the endoplasmic reticulum (ER) and the cis-Golgi. At longer culture duration, the accumulation of intracellular protein with bi-antennary-fucosylated GlcNAc-terminated residues identified the formation of another bottleneck in the medial and trans-Golgi compartments, which subsequently led to a decrease in sialylated species in the secreted protein. Glucose deprivation caused a reduction in the Man8 and Man9 glycans in favor of Man5 glycans and bi-antennary-fucosylated GlcNAc-terminated residues in the organellar pool of the Fc-fusion protein. However, transient deprivation of glucose did not lead to major differences in the glycan profile of proteins secreted into the CM. The approach developed here allows us to probe the secretory pathway and sheds light on the site-specific intracellular processing of glycans during fed-batch cell culture, thus serving as an initial step towards their rational control. Biotechnol. Bioeng. 2017;114: 1550-1560. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
| | - David Spencer
- MedImmune LLC., One MedImmune Way, Gaithersburg, Maryland 20878
| | | | - Nitin Agarwal
- MedImmune LLC., One MedImmune Way, Gaithersburg, Maryland 20878
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30
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Sarafian TA, Littlejohn K, Yuan S, Fernandez C, Cilluffo M, Koo BK, Whitelegge JP, Watson JB. Stimulation of synaptoneurosome glutamate release by monomeric and fibrillated α-synuclein. J Neurosci Res 2017; 95:1871-1887. [PMID: 28117497 DOI: 10.1002/jnr.24024] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 11/11/2016] [Accepted: 12/28/2016] [Indexed: 12/28/2022]
Abstract
The α-synuclein protein exists in vivo in a variety of covalently modified and aggregated forms associated with Parkinson's disease (PD) pathology. However, the specific proteoform structures involved with neuropathological disease mechanisms are not clearly defined. Since α-synuclein plays a role in presynaptic neurotransmitter release, an in vitro enzyme-based assay was developed to measure glutamate release from mouse forebrain synaptoneurosomes (SNs) enriched in synaptic endings. Glutamate measurements utilizing SNs from various mouse genotypes (WT, over-expressers, knock-outs) suggested a concentration dependence of α-synuclein on calcium/depolarization-dependent presynaptic glutamate release from forebrain terminals. In vitro reconstitution experiments with recombinant human α-synuclein proteoforms including monomers and aggregated forms (fibrils, oligomers) produced further evidence of this functional impact. Notably, brief exogenous applications of fibrillated forms of α-synuclein enhanced SN glutamate release but monomeric forms did not, suggesting preferential membrane penetration and toxicity by the aggregated forms. However, when applied to brain tissue sections just prior to homogenization, both monomeric and fibrillated forms stimulated glutamate release. Immuno-gold and transmission electron microscopy (TEM) detected exogenous fibrillated α-synuclein associated with numerous SN membranous structures including synaptic terminals. Western blots and immuno-gold TEM were consistent with SN internalization of α-synuclein. Additional studies revealed no evidence of gross disruption of SN membrane integrity or glutamate transporter function by exogenous α-synuclein. Overall excitotoxicity, due to enhanced glutamate release in the face of either overexpressed monomeric α-synuclein or extrasynaptic exposure to fibrillated α-synuclein, should be considered as a potential neuropathological pathway during the progression of PD and other synucleinopathies. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Theodore A Sarafian
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Kaitlyn Littlejohn
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Sarah Yuan
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Charlene Fernandez
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | | | - Bon-Kyung Koo
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA, USA
| | - Julian P Whitelegge
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Joseph B Watson
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
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31
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Stewart MP, Sharei A, Ding X, Sahay G, Langer R, Jensen KF. In vitro and ex vivo strategies for intracellular delivery. Nature 2016; 538:183-192. [DOI: 10.1038/nature19764] [Citation(s) in RCA: 537] [Impact Index Per Article: 67.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 07/11/2016] [Indexed: 12/11/2022]
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32
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Sun L, Fang J. Macromolecular crowding effect is critical for maintaining SIRT1's nuclear localization in cancer cells. Cell Cycle 2016; 15:2647-2655. [PMID: 27463693 DOI: 10.1080/15384101.2016.1211214] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
SIRT1 is a principle class III histone deacetylase which exhibits versatile functions in stress response, development, and pathological processes including cancer. Although SIRT1 deacetylates a wide range of nuclear and cytoplasmic proteins, its subcellular localization in cancer cells has been controversial. In this study, we uncovered the inconsistent reports about SIRT1 subcellular localization is partially due to different analysis approaches. While immunofluorescence and live cell imaging reveal a predominant nuclear localization of SIRT1, conventional cell fractionation often results in a severe leaking of SIRT1 into the cytoplasm. Such a leakage is mainly caused by loss of cytoplasmic macromolecular crowding effect as well as hypotonic dwelling during the isolation of the nuclei. We also developed an improved cell fractionation procedure which maintains SIRT1 in its original subcellular localization. Analyzing a variety of human cancer cell lines using this approach and other methods demonstrate that SIRT1 predominantly localizes to the nucleus in cancer cells.
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Affiliation(s)
- Lidong Sun
- a Department of Tumor Biology , H. Lee Moffitt Cancer Center and Research Institute , Tampa , FL , USA
| | - Jia Fang
- a Department of Tumor Biology , H. Lee Moffitt Cancer Center and Research Institute , Tampa , FL , USA
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33
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Singh PP, Hawthorne JL, Davis CA, Quintero OA. Permeabilization activated reduction in fluorescence: A novel method to measure kinetics of protein interactions with intracellular structures. Cytoskeleton (Hoboken) 2016; 73:271-85. [PMID: 27126922 DOI: 10.1002/cm.21306] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 04/26/2016] [Accepted: 04/27/2016] [Indexed: 12/31/2022]
Abstract
Understanding kinetic information is fundamental in understanding biological function. Advanced imaging technologies have fostered the development of kinetic analyses in cells. We have developed Permeabilization Activated Reduction in Fluorescence (PARF) analysis for determination of apparent t1/2 and immobile fraction, describing the dissociation of a protein of interest from intracellular structures. To create conditions where dissociation events are observable, cells expressing a fluorescently-tagged protein are permeabilized with digitonin, diluting the unbound protein into the extracellular media. As the media volume is much larger than the cytosolic volume, the concentration of the unbound pool decreases drastically, shifting the system out of equilibrium, favoring dissociation events. Loss of bound protein is observed as loss of fluorescence from intracellular structures and can be fit to an exponential decay. We compared PARF dissociation kinetics with previously published equilibrium kinetics as determined by FRAP. PARF dissociation rates agreed with the equilibrium-based FRAP analysis predictions of the magnitude of those rates. When used to investigate binding kinetics of a panel of cytoskeletal proteins, PARF analysis revealed that filament stabilization resulted in slower fluorescence loss. Additionally, commonly used "general" F-actin labels display differences in kinetic properties, suggesting that not all fluorescently-tagged actin labels interact with the actin network in the same way. We also observed differential dissociation kinetics for GFP-VASP depending on which cellular structure was being labeled. These results demonstrate that PARF analysis of non-equilibrium systems reveals kinetic information without the infrastructure investment required for other quantitative approaches such as FRAP, photoactivation, or in vitro reconstitution assays. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Pali P Singh
- Department of Biology, University of Richmond, Richmond, Virginia
| | | | - Christie A Davis
- Department of Biology, University of Richmond, Richmond, Virginia
| | - Omar A Quintero
- Department of Biology, University of Richmond, Richmond, Virginia
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34
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Schorpp K, Rothenaigner I, Maier J, Traenkle B, Rothbauer U, Hadian K. A Multiplexed High-Content Screening Approach Using the Chromobody Technology to Identify Cell Cycle Modulators in Living Cells. ACTA ACUST UNITED AC 2016; 21:965-77. [PMID: 27044685 DOI: 10.1177/1087057116641935] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 03/08/2016] [Indexed: 02/05/2023]
Abstract
Many screening hits show relatively poor quality regarding later efficacy and safety. Therefore, small-molecule screening efforts shift toward high-content analysis providing more detailed information. Here, we describe a novel screening approach to identify cell cycle modulators with low toxicity by combining the Cell Cycle Chromobody (CCC) technology with the CytoTox-Glo (CTG) cytotoxicity assay. The CCC technology employs intracellularly functional single-domain antibodies coupled to a fluorescent protein (chromobodies) to visualize the cell cycle-dependent redistribution of the proliferating cell nuclear antigen (PCNA) in living cells. This image-based cell cycle analysis was combined with determination of dead-cell protease activity in cell culture supernatants by the CTG assay. We adopted this multiplex approach to high-throughput format and screened 960 Food and Drug Administration (FDA)-approved drugs. By this, we identified nontoxic compounds, which modulate different cell cycle stages, and validated selected hits in diverse cell lines stably expressing CCC. Additionally, we independently validated these hits by flow cytometry as the current state-of-the-art format for cell cycle analysis. This study demonstrates that CCC imaging is a versatile high-content screening approach to identify cell cycle modulators, which can be multiplexed with cytotoxicity assays for early elimination of toxic compounds during screening.
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Affiliation(s)
- Kenji Schorpp
- Assay Development and Screening Platform, Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Bavaria, Germany
| | - Ina Rothenaigner
- Assay Development and Screening Platform, Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Bavaria, Germany
| | - Julia Maier
- Pharmaceutical Biotechnology, University of Tuebingen, Tuebingen, Germany
| | - Bjoern Traenkle
- Pharmaceutical Biotechnology, University of Tuebingen, Tuebingen, Germany
| | - Ulrich Rothbauer
- Pharmaceutical Biotechnology, University of Tuebingen, Tuebingen, Germany Natural and Medical Sciences Institute at the University of Tuebingen, Reutlingen, Germany
| | - Kamyar Hadian
- Assay Development and Screening Platform, Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Bavaria, Germany
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35
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Han L, Chen Y, Niu J, Peng L, Mao Z, Gao C. Encapsulation of a photosensitizer into cell membrane capsules for photodynamic therapy. RSC Adv 2016. [DOI: 10.1039/c6ra07480d] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
CMCs were used to encapsulate MB (CMCs@MB) using temporary permeation of the plasma membrane and resealing. Encapsulation in the CMCs leads to sustained release of MB with enhanced stability against enzymatic reduction and reduced toxicity.
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Affiliation(s)
- Lijie Han
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization
- Department of Polymer Science and Engineering
- Zhejiang University
- Hangzhou 310027
- China
| | - Ying Chen
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization
- Department of Polymer Science and Engineering
- Zhejiang University
- Hangzhou 310027
- China
| | - Jie Niu
- Institute of Pharmaceutics
- College of Pharmaceutical Sciences
- Zhejiang University
- Hangzhou
- P.R. China
| | - Lihua Peng
- Institute of Pharmaceutics
- College of Pharmaceutical Sciences
- Zhejiang University
- Hangzhou
- P.R. China
| | - Zhengwei Mao
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization
- Department of Polymer Science and Engineering
- Zhejiang University
- Hangzhou 310027
- China
| | - Changyou Gao
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization
- Department of Polymer Science and Engineering
- Zhejiang University
- Hangzhou 310027
- China
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36
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Sequential fractionation and isolation of subcellular proteins from tissue or cultured cells. MethodsX 2015; 2:440-5. [PMID: 26740924 PMCID: PMC4678309 DOI: 10.1016/j.mex.2015.11.001] [Citation(s) in RCA: 124] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 11/02/2015] [Indexed: 12/21/2022] Open
Abstract
Many types of studies require the localization of a protein to, or isolation of enriched protein from a specific cellular compartment. Many protocols in the literature and from commercially available kits claim to yield pure cellular fractions. However, in our hands, the former often do not work effectively and the latter may be prohibitively expensive if a large number of fractionations are required. Furthermore, the largely proprietary composition of reagents in commercial kits means that the user is not able to make adjustments if, for example, a particular component affects the activity of a protein of interest. The method described here allows the isolation of purified proteins from three cellular fractions: the cytosol, membrane-bound organelles, and the nucleus. It uses gentle buffers with increasing detergent strength that sequentially lyse the cell membrane, organelle membranes and finally the nuclear membrane.•Quick, simple to replicate or adjust; this method does not require expensive reagents or use of commercial kits•The protocol can be applied to tissue samples or cultured cells without changing buffer components•Yields purified fractions of cytosolic, membrane bound and nuclear proteins, with the proper distribution of the appropriate subcellular markers: GAPDH, VDAC, SERCA2 and lamin A/C.
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37
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Pauloin A, Adenot P, Hue-Beauvais C, Chanat E. The perilipin-2 (adipophilin) coat of cytosolic lipid droplets is regulated by an Arf1-dependent mechanism in HC11 mouse mammary epithelial cells. Cell Biol Int 2015; 40:143-55. [PMID: 26399370 DOI: 10.1002/cbin.10547] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 09/19/2015] [Indexed: 12/11/2022]
Abstract
The cytosolic lipid droplets (cLDs) store excess intracellular lipids, and perilipin-2 is believed to protect cLDs from degradation. Here, we investigated the role of the small G-protein Arf1 and the proteasome in the fates of perilipin-2 and cLDs. In oleate-loaded cells, upon brefeldin A (BFA) treatment, perilipin-2 remained associated with cLDs for at least 30 min before significant release, and proteasomal degradation-mediated decrease was observed. Interestingly, the cLD population did not mimic the decline in perilipin-2. We tested several chemical modulators of regulators of Arf1 activity on the association of perilipin-2 with cLDs. QS11 and Exo2 accelerated the reduction in perilipin-2, although less than BFA. In contrast, Exo1 unexpectedly slowed down its degradation. Correlatively, BFA, QS11, and Exo2 enhanced the dissociation of perilipin-2 from cLDs, whereas Exo1 inhibited it. There was a synergistic effect of BFA with Exo2 and QS11, and of Exo2 with QS11, whereas Exo1 antagonized the effect of BFA without affecting that of Exo2 or QS11. We concluded that the Arf1 complex regulates the association of perilipin-2 with cLDs. Additionally, MG132 and BFA modified the number of cLDs over a relatively short period.
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Affiliation(s)
- Alain Pauloin
- INRA, UR1196 Génomique et Physiologie de la Lactation, Domaine de Vilvert, F-78352 Jouy-en-Josas, France
| | - Pierre Adenot
- INRA-CRJ MIMA2 Platform, Domaine de Vilvert, UMR1198 Biologie du Développement et Reproduction, Domaine de Vilvert, F-78352 Jouy-en-Josas, France
| | - Catherine Hue-Beauvais
- INRA, UR1196 Génomique et Physiologie de la Lactation, Domaine de Vilvert, F-78352 Jouy-en-Josas, France
| | - Eric Chanat
- INRA, UR1196 Génomique et Physiologie de la Lactation, Domaine de Vilvert, F-78352 Jouy-en-Josas, France
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Peng LH, Zhang YH, Han LJ, Zhang CZ, Wu JH, Wang XR, Gao JQ, Mao ZW. Cell Membrane Capsules for Encapsulation of Chemotherapeutic and Cancer Cell Targeting in Vivo. ACS APPLIED MATERIALS & INTERFACES 2015; 7:18628-37. [PMID: 26262951 DOI: 10.1021/acsami.5b05065] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Systemic administration of chemotherapeutic agents can cause indiscriminate drug distribution and severe toxicity. Until now, encapsulation and targeting of drugs have typically relied on synthetic vehicles, which cannot minimize the clearance by the renal system and may also increase the risk of chemical side effects. Cell membrane capsules (CMCs) provide a generic and far more natural approach to the challenges of drug encapsulation and delivery in vivo. Here aptamer AS1411, which can recognize and bind overexpressed nucleolin on a cancer cell membrane, was chemically conjugated onto CMCs. As a result, AS1411 modified CMCs showed enhanced ingestion in certain cancer cells in vitro and accumulation in mouse cancer xenografts in vivo. Chemotherapeutics and contrast agents with therapeutically significant concentrations can be packaged into CMCs by reversible permeating their plasma membranes. The systematic administration of cancer targeting CMCs loaded with doxorubicin hydrochloride can significantly inhibit tumor growth in mouse xenografts, with significantly reduced toxicity compared to free drug. These findings suggest that cancer targeting CMCs may have considerable benefits in drug delivery and cancer treatment.
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Affiliation(s)
- Li-Hua Peng
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University , Hangzhou 310027, People's Republic of China
| | - Yuan-Hong Zhang
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University , Hangzhou 310027, People's Republic of China
| | - Li-Jie Han
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University , Hangzhou 310027, People's Republic of China
| | - Chen-Zhen Zhang
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University , Hangzhou 310027, People's Republic of China
| | - Jia-He Wu
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University , Hangzhou 310027, People's Republic of China
| | - Xia-Rong Wang
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University , Hangzhou 310027, People's Republic of China
| | - Jian-Qing Gao
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University , Hangzhou 310027, People's Republic of China
| | - Zheng-Wei Mao
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University , Hangzhou 310027, People's Republic of China
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Topography of the Human Papillomavirus Minor Capsid Protein L2 during Vesicular Trafficking of Infectious Entry. J Virol 2015; 89:10442-52. [PMID: 26246568 DOI: 10.1128/jvi.01588-15] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 07/29/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The human papillomavirus (HPV) capsid is composed of the major capsid protein L1 and the minor capsid protein L2. During entry, the HPV capsid undergoes numerous conformational changes that result in endosomal uptake and subsequent trafficking of the L2 protein in complex with the viral DNA to the trans-Golgi network. To facilitate this transport, the L2 protein harbors a number of putative motifs that, if capable of direct interaction, would interact with cytosolic host cell factors. These data imply that a portion of L2 becomes cytosolic during infection. Using a low concentration of digitonin to selectively permeabilize the plasma membrane of infected cells, we mapped the topography of the L2 protein during infection. We observed that epitopes within amino acid residues 64 to 81 and 163 to 170 and a C-terminal tag of HPV16 L2 are exposed on the cytosolic side of intracellular membranes, whereas an epitope within residues 20 to 38, which are upstream of a putative transmembrane region, is luminal. Corroborating these findings, we also found that L2 protein is sensitive to trypsin digestion during infection. These data demonstrate that the majority of the L2 protein becomes accessible on the cytosolic side of intracellular membranes in order to interact with cytosolic factors to facilitate vesicular trafficking. IMPORTANCE In order to complete infectious entry, nonenveloped viruses have to pass cellular membranes. This is often achieved through the viral capsid protein associating with or integrating into intracellular membrane. Here, we determine the topography of HPV L2 protein in the endocytic vesicular compartment, suggesting that L2 becomes a transmembrane protein with a short luminal portion and with the majority facing the cytosolic side for interaction with host cell transport factors.
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Zaidi A, Singh KP, Anwar S, Suman SS, Equbal A, Singh K, Dikhit MR, Bimal S, Pandey K, Das P, Ali V. Interaction of frataxin, an iron binding protein, with IscU of Fe-S clusters biogenesis pathway and its upregulation in AmpB resistant Leishmania donovani. Biochimie 2015; 115:120-35. [PMID: 26032732 DOI: 10.1016/j.biochi.2015.05.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 05/19/2015] [Indexed: 01/10/2023]
Abstract
Leishmania donovani is a unicellular protozoon parasite that causes visceral leishmaniasis (VL), which is a fatal disease if left untreated. Certain Fe-S proteins of the TCA cycle and respiratory chain have been found in the Leishmania parasite but the precise mechanisms for their biogenesis and the maturation of Fe-S clusters remains unknown. Fe-S clusters are ubiquitous cofactors of proteins that perform critical cellular functions. The clusters are biosynthesized by the mitochondrial Iron-Sulphur Cluster (ISC) machinery with core protein components that include the catalytic cysteine desulphurase IscS, the scaffold proteins IscU and IscA, and frataxin as an iron carrier/donor. However, no information regarding frataxin, its regulation, or its role in drug resistance is available for the Leishmania parasite. In this study, we characterized Ld-frataxin to investigate its role in the ISC machinery of L. donovani. We expressed and purified the recombinant Ld-frataxin protein and observed its interaction with Ld-IscU by co-purification and pull-down assay. Furthermore, we observed that the cysteine desulphurase activity of the purified Ld-IscS protein was stimulated in the presence of Ld-frataxin and Ld-IscU, particularly in the presence of iron; neither Ld-frataxin nor Ld-IscU alone had significant effects on Ld-IscS activity. Interestingly, RT-PCR and western blotting showed that Ld-frataxin is upregulated in AmpB-resistant isolates compared to sensitive strains, which may support higher Fe-S protein activity in AmpB-resistant L. donovani. Additionally, Ld-frataxin was localized in the mitochondria, as revealed by digitonin fractionation and indirect immunofluorescence. Thus, our results suggest the role of Ld-frataxin as an iron binding/carrier protein for Fe-S cluster biogenesis that physically interacts with other core components of the ISC machinery within the mitochondria.
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Affiliation(s)
- Amir Zaidi
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Agamkuan, Patna 800007, India
| | - Krishn Pratap Singh
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Agamkuan, Patna 800007, India
| | - Shadab Anwar
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Agamkuan, Patna 800007, India
| | - Shashi S Suman
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Agamkuan, Patna 800007, India
| | - Asif Equbal
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Agamkuan, Patna 800007, India
| | - Kuljit Singh
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Agamkuan, Patna 800007, India
| | - Manas R Dikhit
- Biomedical Informatic Centre, Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Agamkuan, Patna, India
| | - Sanjeeva Bimal
- Department of Immunology, Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Agamkuan, Patna, India
| | - Krishna Pandey
- Department of Clinical Medicine, Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Agamkuan, Patna, India
| | - Pradeep Das
- Department of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Agamkuan, Patna, India
| | - Vahab Ali
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Agamkuan, Patna 800007, India.
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41
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Xu S, Kim A, Jeffries GDM, Jesorka A. A rapid microfluidic technique for integrated viability determination of adherent single cells. Anal Bioanal Chem 2014; 407:1295-301. [PMID: 25542567 DOI: 10.1007/s00216-014-8364-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 11/18/2014] [Accepted: 11/20/2014] [Indexed: 10/24/2022]
Abstract
Here, we report on a novel protocol for determining the viability of individual cells in an adherent cell culture, without adversely affecting the remaining cells in the sample. This is facilitated using a freestanding microfluidic perfusion device, the Multifunctional Pipette (MFP), which generates a virtual flow cell around selected single cells. We investigated the utility on four different cell lines, NG108-15, HEK 293, PC12, and CHO, and combined the assay with a cell poration experiment, in which we apply the pore-forming agent digitonin, followed by fluorescein diphosphate, a pre-fluorescent substrate for alkaline phosphatase, in order to monitor intracellular enzyme activity. The cell viability was instantly assessed through simultaneous perfusion with fluorescein diacetate (FDA) and propidium iodide (PI), both being dispensed through the same superfusion device used to porate and deliver the enzyme substrate. In this fluorescence assay, viable and non-viable cells were distinguished by their green and red emission, respectively, within 10 s. In addition, the enzyme activity was monitored over time as a secondary test for cellular activity. Our findings demonstrate that this microfluidic technology-assisted approach is a facile, rapid, and reliable means to determine the viability in single-cell experiments and that viability studies can be performed routinely alongside typical substrate delivery protocols. This approach would remove the need for global cell viability testing and would enable viability studies of only the cells under experimental analysis.
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Affiliation(s)
- Shijun Xu
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 412 96, Gothenburg, Sweden
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Equbal A, Suman SS, Anwar S, Singh KP, Zaidi A, Sardar AH, Das P, Ali V. Stage-dependent expression and up-regulation of trypanothione synthetase in amphotericin B resistant Leishmania donovani. PLoS One 2014; 9:e97600. [PMID: 24901644 PMCID: PMC4046939 DOI: 10.1371/journal.pone.0097600] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 04/22/2014] [Indexed: 11/27/2022] Open
Abstract
Kinetoplastids differ from other organisms in their ability to conjugate glutathione and spermidine to form trypanothione which is involved in maintaining redox homeostasis and removal of toxic metabolites. It is also involved in drug resistance, antioxidant mechanism, and defense against cellular oxidants. Trypanothione synthetase (TryS) of thiol metabolic pathway is the sole enzyme responsible for the biosynthesis of trypanothione in Leishmania donovani. In this study, TryS gene of L. donovani (LdTryS) was cloned, expressed, and fusion protein purified with affinity column chromatography. The purified protein showed optimum enzymatic activity at pH 8.0–8.5. The TryS amino acids sequences alignment showed that all amino acids involved in catalytic and ligands binding of L. major are conserved in L. donovani. Subcellular localization using digitonin fractionation and immunoblot analysis showed that LdTryS is localized in the cytoplasm. Furthermore, RT-PCR coupled with immunoblot analysis showed that LdTryS is overexpressed in Amp B resistant and stationary phase promastigotes (∼2.0-folds) than in sensitive strain and logarithmic phase, respectively, which suggests its involvement in Amp B resistance. Also, H2O2 treatment upto 150 µM for 8 hrs leads to 2-fold increased expression of LdTryS probably to cope up with oxidative stress generated by H2O2. Therefore, this study demonstrates stage- and Amp B sensitivity-dependent expression of LdTryS in L. donovani and involvement of TryS during oxidative stress to help the parasites survival.
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Affiliation(s)
- Asif Equbal
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, AgamKuan, Patna, India
| | - Shashi Shekhar Suman
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, AgamKuan, Patna, India
| | - Shadab Anwar
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, AgamKuan, Patna, India
| | - Krishn Pratap Singh
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, AgamKuan, Patna, India
| | - Amir Zaidi
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, AgamKuan, Patna, India
| | - Abul Hasan Sardar
- Department of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences, AgamKuan, Patna, India
| | - Pradeep Das
- Department of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences, AgamKuan, Patna, India
| | - Vahab Ali
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, AgamKuan, Patna, India
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Divakaruni AS, Rogers GW, Murphy AN. Measuring Mitochondrial Function in Permeabilized Cells Using the Seahorse XF Analyzer or a Clark-Type Oxygen Electrode. ACTA ACUST UNITED AC 2014; 60:25.2.1-16. [PMID: 24865646 DOI: 10.1002/0471140856.tx2502s60] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Measurements of mitochondrial respiration in intact cells can help define metabolism and its dysregulation in fields such as cancer, metabolic disease, immunology, and neurodegeneration. Although cells can be offered various substrates in the assay medium, many cell types can oxidize stored pools of energy substrates. A general bioenergetic profile can therefore be obtained using intact cells, but the inability to control substrate provision to the mitochondria can restrict an in-depth, mechanistic understanding. Mitochondria can be isolated from intact cells, but the yield and quality of the end product is often poor and prone to subselection during isolation. Plasma membrane permeabilization of cells provides a solution to this challenge, allowing experimental control of the medium surrounding the mitochondria. This unit describes techniques to measure respiration in permeabilized adherent cells using a Seahorse XF Analyzer or permeabilized suspended cells in a Hansatech Oxygraph.
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Affiliation(s)
- Ajit S Divakaruni
- Department of Pharmacology, University of California, San Diego, La Jolla, California
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44
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Hung YP, Yellen G. Live-cell imaging of cytosolic NADH-NAD+ redox state using a genetically encoded fluorescent biosensor. Methods Mol Biol 2014; 1071:83-95. [PMID: 24052382 PMCID: PMC4330558 DOI: 10.1007/978-1-62703-622-1_7] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/23/2023]
Abstract
NADH is an essential redox cofactor in numerous metabolic reactions, and the cytosolic NADH-NAD(+) redox state is a key parameter in glycolysis. Conventional NADH measurements rely on chemical determination or autofluorescence imaging, which cannot assess NADH specifically in the cytosol of individual live cells. By combining a bacterial NADH-binding protein and a fluorescent protein variant, we have created a genetically encoded fluorescent biosensor of the cytosolic NADH-NAD(+) redox state, named Peredox (Hung et al., Cell Metab 14:545-554, 2011). Here, we elaborate on imaging methods and technical considerations of using Peredox to measure cytosolic NADH:NAD(+) ratios in individual live cells.
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Affiliation(s)
- Yin Pun Hung
- Department of Neurobiology, Harvard Medical School, Cambridge, MA, USA
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45
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Mitochondrial toxin betulinic acid induces in vitro eryptosis in human red blood cells through membrane permeabilization. Arch Toxicol 2013; 88:755-68. [PMID: 24241250 DOI: 10.1007/s00204-013-1162-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 11/05/2013] [Indexed: 01/12/2023]
Abstract
Betulinic acid (BA), a compound isolated from the bark of white birch (Betula pubescens), was reported to induce apoptosis in many types of cancer through mitochondrial dysfunction with low side effects in normal cells. Because of these features, BA is regarded as a potential anti-cancer agent. However, the effect of BA on the induction of cell death in human erythrocytes remains unknown. Given that BA is a mitochondrial toxin and mitochondria are the central cell death regulator, we hypothesized that BA is unable to elicit apoptosis (also known as eryptosis or erythroptosis) in human erythrocytes devoid of mitochondria. This study therefore tried to determine the in vitro effect of BA on the induction of eryptosis/erythroptosis. Contrary to our prediction, BA caused phosphatidylserine externalization, increase in cellular Ca(2+) ion concentration ([Ca(2+)]i) and eryptosis/erythroptosis in human erythrocytes with a lethal dose larger than that in cancer lines. Mechanistically, the rise of [Ca(2+)]i seems not to be the only key mediator in the BA-mediated eryptosis/erythroptosis because depletion of external Ca(2+) and use of Ca(2+) channels blockers could not eliminate the BA's effect. Also, BA was able to elicit discocyte-echinocyte transformation and release calcein from the RBC ghosts in a way similar to digitonin through membrane permeabilization. Collectively, we report here for the first time that BA induced eryptosis/erythroptosis in human erythrocytes through Ca(2+) loading and membrane permeabilization.
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46
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Olofsson J, Xu S, Jeffries GDM, Jesorka A, Bridle H, Isaksson I, Weber SG, Orwar O. Probing enzymatic activity inside single cells. Anal Chem 2013; 85:10126-33. [PMID: 24003961 PMCID: PMC3882690 DOI: 10.1021/ac4013122] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report a novel approach for determining the enzymatic activity within a single suspended cell. Using a steady-state microfluidic delivery device and timed exposure to the pore-forming agent digitonin, we controlled the plasma membrane permeation of individual NG108-15 cells. Mildly permeabilized cells (~100 pores) were exposed to a series of concentrations of fluorescein diphosphate (FDP), a fluorogenic alkaline phosphatase substrate, with and without levamisole, an alkaline phosphatase inhibitor. We generated quantitative estimates for intracellular enzyme activity and were able to construct both dose-response and dose-inhibition curves at the single-cell level, resulting in an apparent Michaelis contant Km of 15.3 μM ± 1.02 (mean ± standard error of the mean (SEM), n = 16) and an inhibition constant Ki of 0.59 mM ± 0.07 (mean ± SEM, n = 14). Enzymatic activity could be monitored just 40 s after permeabilization, and five point dose-inhibition curves could be obtained within 150 s. This rapid approach offers a new methodology for characterizing enzyme activity within single cells.
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Affiliation(s)
- Jessica Olofsson
- Department of Chemical and Biological Engineering, Chalmers University of Technology , Kemivägen 10, SE-412 96 Gothenburg, Sweden
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47
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Breslow DK, Koslover EF, Seydel F, Spakowitz AJ, Nachury MV. An in vitro assay for entry into cilia reveals unique properties of the soluble diffusion barrier. ACTA ACUST UNITED AC 2013; 203:129-47. [PMID: 24100294 PMCID: PMC3798247 DOI: 10.1083/jcb.201212024] [Citation(s) in RCA: 138] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The ciliary permeability barrier is mechanistically distinct from other cellular diffusion barriers and allows soluble proteins under ∼100 kD in size to enter cilia in the absence of active transport. Specific proteins are concentrated within primary cilia, whereas others remain excluded. To understand the mechanistic basis of entry into cilia, we developed an in vitro assay using cells in which the plasma membrane was permeabilized, but the ciliary membrane was left intact. Using a diffusion-to-capture system and quantitative analysis, we find that proteins >9 nm in diameter (∼100 kD) are restricted from entering cilia, and we confirm these findings in vivo. Interference with the nuclear pore complex (NPC) or the actin cytoskeleton in permeabilized cells demonstrated that the ciliary diffusion barrier is mechanistically distinct from those of the NPC or the axon initial segment. Moreover, applying a mass transport model to this system revealed diffusion coefficients for soluble and membrane proteins within cilia that are compatible with rapid exploration of the ciliary space in the absence of active transport. Our results indicate that large proteins require active transport for entry into cilia but not necessarily for movement inside cilia.
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Affiliation(s)
- David K Breslow
- Department of Molecular and Cellular Physiology and 2 Department of Chemical Engineering, Stanford University School of Medicine, Stanford, CA 94305
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48
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Gao M, Wong SY, Lau PM, Kong SK. Ferutinin induces in vitro eryptosis/erythroptosis in human erythrocytes through membrane permeabilization and calcium influx. Chem Res Toxicol 2013; 26:1218-28. [PMID: 23848973 DOI: 10.1021/tx400127w] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Ferutinin, isolated from the root of Ferula hermonis and proposed to be used as an antiosteoporosis phytoestrogen, has death promoting activities in a number of cancer cells. However, the effect of ferutinin on the induction of apoptosis in human red blood cells (RBCs), also known as eryptosis or erythroptosis, remains unclear. Given that ferutinin is a small molecule that can induce apoptosis in the cancer cells by opening the mitochondrial permeability transition pores, we therefore hypothesized that the effect of ferutinin to elicit apoptosis in human RBCs devoid of mitochondria would be minimal. This study tried to determine the in vitro effect of ferutinin on the induction of apoptosis in human RBCs. Eryptosis/erythroptosis after ferutinin treatment was examined for phosphatidylserine (PS) externalization, calcein leakage, and other apoptotic feature events by flow cytometry and confocal microscopy. Contrary to our prediction, ferutinin caused eryptosis/erythroptosis in human RBCs and simultaneously increased caspase-3 activity and the cytosolic free Ca(2+) ion level ([Ca(2+)]i). Yet, Ca(2+) seems not to be the sole mediator in ferutinin-mediated eryptosis/erythroptosis because depletion of the external Ca(2+) could not eliminate the apoptotic effect from ferutinin. Subsequent replenishment of the external Ca(2+) was able to promote PS externalization, caspase-3 activation, and rise of [Ca(2+)]i. Also, ferutinin at high dose (40 μM or above) was able to permeabilize the membrane of RBC ghosts in a way similar to that of digitonin. At low dose, ferutinin activated the P- and L-type Ca(2+) channels as the ferutinin-mediated [Ca(2+)]i rise was suppressed by the P-type (ω-agatoxin IVA) and L-type (verapamil and diltiazem) Ca(2+) channel blockers. Taken together, we report here for the first time that ferutinin induces in vitro apoptosis in human RBCs. Mechanistically, eryptosis/erythroptosis is mediated by membrane permeabilization and upregulation of [Ca(2+)]i with the activation of caspase-3.
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Affiliation(s)
- Minghui Gao
- Programme of Biochemistry, School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
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49
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Hagström AK, Walther A, Wendland J, Löfstedt C. Subcellular localization of the fatty acyl reductase involved in pheromone biosynthesis in the tobacco budworm, Heliothis virescens (Noctuidae: Lepidoptera). INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2013; 43:510-521. [PMID: 23537692 DOI: 10.1016/j.ibmb.2013.03.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 03/05/2013] [Accepted: 03/08/2013] [Indexed: 06/02/2023]
Abstract
Sex pheromone components are produced in specialized glands of female moths via well-characterized biosynthetic pathways, where a Fatty Acyl Reductase (FAR) is often essential for producing the specific ratio of the different pheromone components. The subcellular localization and membrane topology of FARs is important for understanding how pheromones are synthesized and exported to the exterior for release. We investigated the subcellular localization of HvFAR from the noctuid moth Heliothis virescens by producing recombinant fusion proteins with green fluorescent protein (GFP) in yeast. A C-terminally tagged construct was localized to the endoplasmic reticulum (ER) and retained full reductive activity on a broad range of saturated and unsaturated fatty acyl precursors. In contrast, an N-terminally-tagged construct was poorly expressed in the cytoplasm and was not enzymatically active, indicating that HvFAR requires a free N-terminal for both proper targeting and catalytic activity. A series of truncations of the N-and C-termini of HvFAR was conducted based on in silico-predicted hydrophobic domains and transmembrane regions. The N-terminally truncated protein was found in the cytoplasm and did not retain activity, emphasizing the importance of the N-terminal for FAR function. In addition, the orientation in the membrane of the C-terminus-tagged HvFAR-GFP construct was analyzed using a fluorescence protease protection (FPP) assay, implying that the C-terminal of HvFAR is orientated towards the cytoplasm. These results, together with previous data on the localization of desaturases, confirm the importance of the ER as a subcellular site of pheromone production.
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Affiliation(s)
- Asa K Hagström
- Pheromone Group, Department of Biology, Lund University, Sölvegatan 37, SE-223 62 Lund, Sweden.
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50
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Thiazolidinediones are acute, specific inhibitors of the mitochondrial pyruvate carrier. Proc Natl Acad Sci U S A 2013; 110:5422-7. [PMID: 23513224 DOI: 10.1073/pnas.1303360110] [Citation(s) in RCA: 220] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Facilitated pyruvate transport across the mitochondrial inner membrane is a critical step in carbohydrate, amino acid, and lipid metabolism. We report that clinically relevant concentrations of thiazolidinediones (TZDs), a widely used class of insulin sensitizers, acutely and specifically inhibit mitochondrial pyruvate carrier (MPC) activity in a variety of cell types. Respiratory inhibition was overcome with methyl pyruvate, localizing the effect to facilitated pyruvate transport, and knockdown of either paralog, MPC1 or MPC2, decreased the EC50 for respiratory inhibition by TZDs. Acute MPC inhibition significantly enhanced glucose uptake in human skeletal muscle myocytes after 2 h. These data (i) report that clinically used TZDs inhibit the MPC, (ii) validate that MPC1 and MPC2 are obligatory components of facilitated pyruvate transport in mammalian cells, (iii) indicate that the acute effect of TZDs may be related to insulin sensitization, and (iv) establish mitochondrial pyruvate uptake as a potential therapeutic target for diseases rooted in metabolic dysfunction.
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