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Zahr AS, Davis CA, Pishko MV. Macrophage uptake of core-shell nanoparticles surface modified with poly(ethylene glycol). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:8178-85. [PMID: 16952259 DOI: 10.1021/la060951b] [Citation(s) in RCA: 201] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The in vitro uptake of core-shell nanoparticles encapsulated in a bio-macromolecular nanoshell assembled from multilayered polyelectrolytes was studied. Sulfate modified fluorescent polystyrene nanobeads (diameter 200 nm) were used as a solid core upon which charged multilayers of poly-l-lysine, chitosan, and heparin sulfate are electrostatically deposited utilizing a layer-by-layer (LbL) self-assembly process. The nanoshell composed of the multilayered polyelectrolytes was modified with poly(ethylene glycol) (PEG) of varying molecular weights (either MW 2000, 5000, or 20 000 Da) to form a hydrophilic and long-circulating nanoparticle. The assembly of the nanoshell was confirmed by zeta potential, transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The reversal in charge upon the deposition of alternating polyelectrolytes was observed by zeta potential measurements. The nanometer thickness of the nanoshell was confirmed by TEM. The presence of the (C-C-O)(n)() backbone in PEG at the surface of the nanoshell was confirmed by the increase in (C-O,N) peak area concentrations compared to (C-C) peak area, and these results were gathered from XPS. In vitro studies between suspension macrophages and core-shell nanoparticles were performed to determine how the hydrophilicity and the charge on the nanoshell can promote or reduce uptake. Results showed that after 24 h uptake was decreased 3-fold when PEGs of 2000 and 20 000 Da were chemisorbed to the nanoshell, as opposed to a nanoshell with either a positive or highly negative charge. Confocal microscopy aided in verifying that core-shell nanoparticles were internalized within the cell cytoplasm and were not attached to the cell surface. Protein adhesion studies with bovine serum albumin were performed to determine the relationship between surface charge and opsonization of core-shell nanoparticles. It was found that a hydrophilic surface with a low negative charge reduced protein adsorption and uptake. The in vitro uptake of macrophages and protein adsorption onto core-shell nanoparticles formed using layer-by-layer assembly has not been previously studied.
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Affiliation(s)
- Alisar S Zahr
- Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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52
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Fa N, Ronkart S, Schanck A, Deleu M, Gaigneaux A, Goormaghtigh E, Mingeot-Leclercq MP. Effect of the antibiotic azithromycin on thermotropic behavior of DOPC or DPPC bilayers. Chem Phys Lipids 2006; 144:108-16. [PMID: 17007828 DOI: 10.1016/j.chemphyslip.2006.08.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2006] [Accepted: 08/08/2006] [Indexed: 11/18/2022]
Abstract
Azithromycin is a macrolide antibiotic known to bind to lipids and to affect endocytosis probably by interacting with lipid membranes [Tyteca, D., Schanck, A., Dufrene, Y.F., Deleu, M., Courtoy, P.J., Tulkens, P.M., Mingeot-Leclercq, M.P., 2003. The macrolide antibiotic azithromycin interacts with lipids and affects membrane organization and fluidity: studies on Langmuir-Blodgett monolayers, liposomes and J774 macrophages. J. Membr. Biol. 192, 203-215]. In this work, we investigate the effect of azithromycin on lipid model membranes made of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) or 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC). Thermal transitions of both lipids in contact with azithromycin are studied by (31)P NMR and DSC on multilamellar vesicles. Concerning the DPPC, azithromycin induces a suppression of the pretransition whereas a phase separation between the DOPC and the antibiotic is observed. For both lipids, the enthalpy associated with the phase transition is strongly decreased with azithromycin. Such effects may be due to an increase of the available space between hydrophobic chains after insertion of azithromycin in lipids. The findings provide a molecular insight of the phase merging of DPPC gel in DOPC fluid matrix induced by azithromycin [Berquand, A., Mingeot-Leclercq, M.P., Dufrene, Y.F., 2004. Real-time imaging of drug-membrane interactions by atomic force microscopy. Biochim. Biophys. Acta 1664, 198-205] and could help to a better understanding of azithromycin-cell interaction.
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Affiliation(s)
- N Fa
- Unité de Pharmacologie Cellulaire et Moléculaire, Université Catholique de Louvain, 73.70 Avenue E. Mounier 73, B-1200 Brussels, Belgium
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Barcia-Macay M, Seral C, Mingeot-Leclercq MP, Tulkens PM, Van Bambeke F. Pharmacodynamic evaluation of the intracellular activities of antibiotics against Staphylococcus aureus in a model of THP-1 macrophages. Antimicrob Agents Chemother 2006; 50:841-51. [PMID: 16495241 PMCID: PMC1426441 DOI: 10.1128/aac.50.3.841-851.2006] [Citation(s) in RCA: 204] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The pharmacodynamic properties governing the activities of antibiotics against intracellular Staphylococcus aureus are still largely undetermined. Sixteen antibiotics of seven different pharmacological classes (azithromycin and telithromycin [macrolides]; gentamicin [an aminoglycoside]; linezolid [an oxazolidinone]; penicillin V, nafcillin, ampicillin, and oxacillin [beta-lactams]; teicoplanin, vancomycin, and oritavancin [glycopeptides]; rifampin [an ansamycin]; and ciprofloxacin, levofloxacin, garenoxacin, and moxifloxacin [quinolones]) have been examined for their activities against S. aureus (ATCC 25923) in human THP-1 macrophages (intracellular) versus that in culture medium (extracellular) by using a 0- to 24-h exposure time and a wide range of extracellular concentrations (including the range of the MIC to the maximum concentration in serum [C(max); total drug] of humans). All molecules except the macrolides caused a net reduction in bacterial counts that was time and concentration/MIC ratio dependent (four molecules tested in detail [gentamicin, oxacillin, moxifloxacin, and oritavancin] showed typical sigmoidal dose-response curves at 24 h). Maximal intracellular activities remained consistently lower than extracellular activities, irrespective of the level of drug accumulation and of the pharmacological class. Relative potencies (50% effective concentration or at a fixed extracellular concentration/MIC ratio) were also decreased, but to different extents. At an extracellular concentration corresponding to their C(max)s (total drug) in humans, only oxacillin, levofloxacin, garenoxacin, moxifloxacin, and oritavancin had truly intracellular bactericidal effects (2-log decrease or more, as defined by the Clinical and Laboratory Standards Institute guidelines). The intracellular activities of antibiotics against S. aureus (i) are critically dependent upon their extracellular concentrations and the duration of cell exposure (within the 0- to 24-h time frame) to antibiotics and (ii) are always lower than those that can be observed extracellularly. This model may help in rationalizing the choice of antibiotic for the treatment of S. aureus intracellular infections.
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Affiliation(s)
- Maritza Barcia-Macay
- Unité de Pharmacologie Cellulaire et Moléculaire, Université Catholique de Louvain, UCL 7370 Avenue E. Mounier 73, B-1200 Brussels, Belgium
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54
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Van Bambeke F, Saffran J, Mingeot-Leclercq MP, Tulkens PM. Mixed-lipid storage disorder induced in macrophages and fibroblasts by oritavancin (LY333328), a new glycopeptide antibiotic with exceptional cellular accumulation. Antimicrob Agents Chemother 2005; 49:1695-700. [PMID: 15855483 PMCID: PMC1087646 DOI: 10.1128/aac.49.5.1695-1700.2005] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Oritavancin, a semisynthetic derivative of vancomycin endowed with a cationic amphiphilic character, accumulates to large extent in the lysosomes of eukaryotic cells (F. Van Bambeke, S. Carryn, C. Seral, H. Chanteux, D. Tyteca, M. P. Mingeot-Leclercq, and P. M. Tulkens, Antimicrob. Agents Chemother. 48:2853-2860, 2004). In the present study, we examined whether this accumulation could cause cell alterations in phagocytic (J774 mouse macrophages) and nonphagocytic (rat embryo fibroblasts) cells exposed to clinically meaningful (0- to 40-mg/liter) concentrations of oritavancin. Optical and electronic microscopy evidenced conspicuous alterations of the vacuolar apparatus in both cell types, characterized by the deposition of concentric lamellar structures, finely granular material, or other less-defined osmiophilic material, often deposed in giant vesicles. Biochemical studies showed an accumulation of phospholipids (1.5 x control values) and free and esterified cholesterol (3 to 4 x control values for total cholesterol). Accumulation of these lipids was in close relation to that of oritavancin (excess phospholipid/oritavancin and excess cholesterol/oritavancin molar ratios of 2 to 3 and 3 to 5, respectively). Cholesterol accumulation was rapid and reversible, and that of phospholipids was slower and poorly reversible. Vancomycin and teicoplanin, used as controls (50 and 100 mg/liter, respectively), did not cause any significant change in the lipid content of fibroblasts. The data therefore suggest that oritavancin has the potential to cause a mixed-lipid storage disorder in eukaryotic cells.
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Affiliation(s)
- Françoise Van Bambeke
- Unité de Pharmacologie cellulaire et moléculaire, Université catholique de Louvain, Brussels, Belgium.
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55
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Berquand A, Fa N, Dufrêne YF, Mingeot-Leclercq MP. Interaction of the Macrolide Antibiotic Azithromycin with Lipid Bilayers: Effect on Membrane Organization, Fluidity, and Permeability. Pharm Res 2005; 22:465-75. [PMID: 15835753 DOI: 10.1007/s11095-004-1885-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
PURPOSE To investigate the effect of a macrolide antibiotic, azithromycin, on the molecular organization of DPPC:DOPC, DPPE:DOPC, SM:DOPC, and SM:Chol:DOPC lipid vesicles as well as the effect of azithromycin on membrane fluidity and permeability. METHODS The molecular organization of model membranes was characterized by atomic force microscopy (AFM), and the amount of azithromycin bound to lipid membranes was determined by equilibrium dialysis. The membrane fluidity and permeability were analyzed using fluorescence polarization studies and release of calcein-entrapped liposomes, respectively. RESULTS In situ AFM images revealed that azithromycin leads to the erosion and disappearance of DPPC and DPPE gel domains, whereas no effect was noted on SM and SM:cholesterol domains. Although azithromycin did not alter the permeability of DPPC:DOPC, DPPE:DOPC, SM:DOPC, and SM:Chol:DOPC lipid vesicles, it increased the fluidity at the hydrophilic/hydrophobic interface in DPPC:DOPC and DPPE:DOPC models. This effect may be responsible for the ability of azithromycin to erode the DPPC and DPPE gel domains, as observed by AFM. CONCLUSIONS This study shows the interest of both AFM and biophysical methods to characterize the drug-membrane interactions.
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Affiliation(s)
- A Berquand
- Unité de Chimie des Interfaces, Université Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
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56
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Willis MS, Klassen LW, Carlson DL, Brouse CF, Thiele GM. Malondialdehyde-acetaldehyde haptenated protein binds macrophage scavenger receptor(s) and induces lysosomal damage. Int Immunopharmacol 2005; 4:885-99. [PMID: 15182728 DOI: 10.1016/j.intimp.2004.04.004] [Citation(s) in RCA: 211] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2004] [Revised: 03/16/2004] [Accepted: 04/02/2004] [Indexed: 11/24/2022]
Abstract
There is evidence that the chemical modification of proteins (haptens) with malondialdehyde-acetaldehyde (MAA) and the immune response to these haptenated proteins is associated with the initiation and/or progression of alcohol liver disease. Experimentally, proteins modified with MAA induce antibody and T cell responses, which are mediated by scavenger receptor(s). Moreover, macrophages have been shown to play an important role in processing and presenting MAA-haptenated proteins in vitro. In vitro, MAA-modified proteins have been shown to induce both apoptosis and necrosis in a dose- and cell-type-dependent manner. Natural ligands modified by oxidative stress, such as oxidized LDL, similarly initiate not only antibody responses, but also cause cell death by disrupting lysosomes after binding to scavenger receptors and internalization. We therefore investigated the binding, internalization, and lysosomal integrity in a macrophage cell line to a MAA-haptenated protein. We demonstrate for the first time that MAA-haptenated proteins are preferentially bound by scavenger receptors on macrophages, which internalize the ligands and shuttle them to lysosomes. Moreover, MAA-haptenated proteins are demonstrated to be associated with a rapid dose-dependent disruption in lysosomal integrity, resulting in leakage and caspase activation. Similarly, as hen egg lysozyme (HEL)-MAA concentrations increased (>31.3 microg/ml), increased levels of apoptosis and a G1/S cell cycle checkpoint inhibition were identified. This study identifies mechanisms by which MAA-haptenated proteins are taken up by a representative antigen-presenting cell and may delineate steps by which MAA-haptenated proteins induce cell death and induce their immunogenicity to the carrier protein.
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Affiliation(s)
- Monte S Willis
- Department of Internal Medicine, University of Nebraska Medical Center, 983025 Nebraska Medical Center, Omaha, NE 68198-3025, USA.
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57
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Emonard H, Bellon G, Troeberg L, Berton A, Robinet A, Henriet P, Marbaix E, Kirkegaard K, Patthy L, Eeckhout Y, Nagase H, Hornebeck W, Courtoy PJ. Low density lipoprotein receptor-related protein mediates endocytic clearance of pro-MMP-2.TIMP-2 complex through a thrombospondin-independent mechanism. J Biol Chem 2004; 279:54944-51. [PMID: 15489233 DOI: 10.1074/jbc.m406792200] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The low density lipoprotein receptor-related protein (LRP) mediates the endocytic clearance of various proteinases and proteinase.inhibitor complexes, including thrombospondin (TSP)-dependent endocytosis of matrix metalloproteinase (MMP)-2 (or gelatinase A), a key effector of extracellular matrix remodeling and cancer progression. However, the zymogen of MMP-2 (pro-MMP-2) mostly occurs in tissues as a complex with the tissue inhibitor of MMPs (TIMP-2). Here we show that clearance of the pro-MMP-2.TIMP-2 complex is also mediated by LRP, because addition of receptor-associated protein (RAP), a natural LRP ligand antagonist, inhibited endocytosis and lysosomal degradation of (125)I-pro-MMP-2.TIMP-2. Both TIMP-2 and the pro-MMP-2 collagen-binding domain independently competed for endocytosis of (125)I-pro-MMP-2.TIMP-2 complex. Surface plasmon resonance studies indicated that pro-MMP-2, TIMP-2, and pro-MMP-2.TIMP-2 directly interact with LRP in the absence of TSP. LRP-mediated endocytic clearance of (125)I-pro-MMP-2 was inhibited by anti-TSP antibodies and accelerated upon complexing with TSP-1, but these treatments had no effect on (125)I-pro-MMP-2.TIMP-2 uptake. This implies that mechanisms of clearance by LRP of pro-MMP-2 and pro-MMP-2.TIMP-2 complex are different. Interestingly, RAP did not inhibit binding of (125)I-pro-MMP-2.TIMP-2 to the cell surface. We conclude that clearance of pro-MMP-2.TIMP-2 complex is a TSP-independent two-step process, involving (i) initial binding to the cell membrane in a RAP-insensitive manner and (ii) subsequent LRP-dependent (RAP-sensitive) internalization and degradation.
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Affiliation(s)
- Hervé Emonard
- CNRS UMR 6198, IFR 53 Biomolecules, Faculty of Medicine, F-51100 Reims, France
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58
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Van Bambeke F, Carryn S, Seral C, Chanteux H, Tyteca D, Mingeot-Leclercq MP, Tulkens PM. Cellular pharmacokinetics and pharmacodynamics of the glycopeptide antibiotic oritavancin (LY333328) in a model of J774 mouse macrophages. Antimicrob Agents Chemother 2004; 48:2853-60. [PMID: 15273091 PMCID: PMC478544 DOI: 10.1128/aac.48.8.2853-2860.2004] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The intracellular pharmacokinetics and pharmacodynamics of oritavancin (LY333328) were studied in cultured cells. Oritavancin was avidly accumulated by J774 and THP-1 macrophages and rat fibroblasts and to a lesser extent by LLC-PK1 and Caco-2 cells. In J774 macrophages, the level of accumulation reached a plateau (at 370-fold the extracellular concentration) within 24 h and was partly defeated by a rise in serum protein levels. Efflux was incomplete (with a plateau at two-thirds of the original level at 6 h). In short-term kinetic studies, oritavancin uptake was linear for up to 4 h (as was the case for horseradish peroxidase and small latex beads, used as markers of the fluid phase and adsorptive endocytosis, respectively), which was in contrast to azithromycin and chloroquine uptake (which accumulate in cells by diffusion and segregation). The rates of clearance of oritavancin and latex beads were comparable (150 and 120 microl x mg of protein(-1) x h(-1), respectively) and were approximately 200 times higher than that of horseradish peroxidase. Oritavancin accumulation was partially reduced by monensin but was unaffected by acidic pH (these conditions abolished chloroquine accumulation). Cell-associated oritavancin was found in lysosomal fractions after homogenization of J774 macrophages and fractionation by isopycnic centrifugation. Oritavancin was bactericidal against intracellular Staphylococcus aureus (phagolysosomal infection) but was unable to control the intracellular growth of Listeria monocytogenes (cytosolic infection), even though its cellular concentration largely exceeded the MIC (0.02 mg/liter) and minimal bactericidal concentration (2 mg/liter). We conclude that oritavancin enters cells by adsorptive endocytosis (favored by its lipophilic side chain and/or the presence of three protonatable amines), which drives it to lysosomes, where it exerts antibiotic activity.
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Affiliation(s)
- Françoise Van Bambeke
- Unité de Pharmacologie Cellulaire et Moléculaire, Université Catholique de Louvain, Brussels, Belgium.
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59
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Michot JM, Van Bambeke F, Mingeot-Leclercq MP, Tulkens PM. Active efflux of ciprofloxacin from J774 macrophages through an MRP-like transporter. Antimicrob Agents Chemother 2004; 48:2673-82. [PMID: 15215125 PMCID: PMC434197 DOI: 10.1128/aac.48.7.2673-2682.2004] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The accumulation and efflux kinetics of ciprofloxacin have been examined by using murine J774 macrophages. Accumulation (at equilibrium) was increased (three- to fourfold) (i) when cells were incubated with high extracellular drug concentrations (typically 200 mg/liter) as opposed to clinically meaningful concentrations (10 mg/liter or lower), (ii) during ATP- depletion and at acid pH, and (iii) during coincubation with probenecid, gemfibrozil and the preferential multidrug resistance-related protein (MRP) inhibitor MK571. All these conditions were also associated with a marked decrease in ciprofloxacin efflux (half-lives increased from <2 min in controls to up to 10 min). Monensin (a proton ionophore), verapamil, and the preferential P-glycoprotein (P-gp) inhibitor GF120918 had no or only minimal effect, while cyclosporin A, which is not specific for P-gp but also acts on MRP, had an intermediate effect. Short-term uptake studies showed that the influence of the modulators on the apparent drug influx was almost immediate (delay of < or =1 min). Cells made resistant to probenecid and showing a marked overexpression of MRP1 (by Western blot analysis and confocal microscopy) accumulated ciprofloxacin to almost the same extent as did control cells, but efflux was inhibited less by probenecid, gemfibrozil, and MK571. We conclude that ciprofloxacin is subject to constitutive efflux in J774 macrophages through the activity of an MRP-related transporter which is probably distinct from MRP1. We also suggest that the cellular accumulation of ciprofloxacin in wild-type cells is constitutively impaired at therapeutically meaningful concentrations.
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Affiliation(s)
- Jean-Michel Michot
- Unité de Pharmacologie Cellulaire et Moléculaire, Université Catholique de Louvain, UCL 7370, Ave. E. Mounier 73, B-1200 Brussels, Belgium
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Carryn S, Chanteux H, Seral C, Mingeot-Leclercq MP, Van Bambeke F, Tulkens PM. Intracellular pharmacodynamics of antibiotics. Infect Dis Clin North Am 2004; 17:615-34. [PMID: 14711080 DOI: 10.1016/s0891-5520(03)00066-7] [Citation(s) in RCA: 142] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This article establishes the pharmacokinetic-pharmacodynamic parameters that are important when considering the intracellular activity of antibiotics. Generally speaking, the main classes of antibiotics seem to share globally the same properties against extracellular and intracellular organisms. The specific cellular pharmacokinetic properties may modulate those parameters so as to let other ones to become critical. Simple rules, such as equating accumulation and activity, are certainly incorrect, and other determinants need to be added to the equation. Finally, this article emphasizes the fact that much remains to be done in this area before rational therapeutic choices can be made.
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Affiliation(s)
- Stéphane Carryn
- Unité de Pharmacologie Cellulaire et Moléculaire, Université Catholique de Louvain, UCL 73.70 Avenue E. Mourier 73, Brussels B-1200, Belgium
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61
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Christensen EI, Devuyst O, Dom G, Nielsen R, Van Der Smissen P, Verroust P, Leruth M, Guggino WB, Courtoy PJ. Loss of chloride channel ClC-5 impairs endocytosis by defective trafficking of megalin and cubilin in kidney proximal tubules. Proc Natl Acad Sci U S A 2003; 100:8472-7. [PMID: 12815097 PMCID: PMC166253 DOI: 10.1073/pnas.1432873100] [Citation(s) in RCA: 240] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Loss of the renal endosome-associated chloride channel, ClC-5, in Dent's disease and knockout (KO) mice strongly inhibits endocytosis of filtered proteins by kidney proximal tubular cells (PTC). The underlying mechanism remains unknown. We therefore tested whether this endocytic failure could primarily reflect a loss of reabsorption by the multiligand receptors, megalin, and cubilin, caused by a trafficking defect. Impaired protein endocytosis in PTC of ClC-5 KO mice was demonstrated by (i) a major decreased uptake of injected 125I-beta 2-microglobulin, but not of the fluid-phase tracer, FITC-dextran, (ii) reduced labeling of endosomes by injected peroxidase and for the endogenous megalin/cubilin ligands, vitamin D- and retinol-binding proteins, and (iii) urinary appearance of low-molecular-weight proteins and the selective cubilin ligand, transferrin. Contrasting with preserved mRNA levels, megalin and cubilin abundance was significantly decreased in kidney extracts of KO mice. Percoll gradients resolving early and late endosomes (Rab5a, Rab7), brush border (villin, aminopeptidase M), and a dense peak comprising lysosomes (acid hydrolases) showed a disappearance of the brush border component for megalin and cubilin in KO mice. Quantitative ultrastructural immunogold labeling confirmed the overall decrease of megalin and cubilin in PTC and their selective loss at the brush border. In contrast, total contents of the rate-limiting endocytic catalysts, Rab5a and Rab7, were unaffected. Thus, impaired protein endocytosis caused by invalidation of ClC-5 primarily reflects a trafficking defect of megalin and cubilin in PTC.
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Affiliation(s)
- Erik I. Christensen
- Institute of Anatomy, Department of Cell
Biology, University of Aarhus, DK-8000 Aarhus C, Denmark;
Division of Nephrology, Medical School, and
Christian de Duve Institute of Cellular
Pathology, Cell Unit, Université Catholique de Louvain, B-1200
Brussels, Belgium; Institut National de la
Santé et de la Recherche Médicale, U538, Centre
Hospitalo-Universitaire Saint Antoine, F-75012 Paris, France; and
Departments of Physiology and Medicine, The Johns
Hopkins University School of Medicine, Baltimore, MD 21205
| | - Olivier Devuyst
- Institute of Anatomy, Department of Cell
Biology, University of Aarhus, DK-8000 Aarhus C, Denmark;
Division of Nephrology, Medical School, and
Christian de Duve Institute of Cellular
Pathology, Cell Unit, Université Catholique de Louvain, B-1200
Brussels, Belgium; Institut National de la
Santé et de la Recherche Médicale, U538, Centre
Hospitalo-Universitaire Saint Antoine, F-75012 Paris, France; and
Departments of Physiology and Medicine, The Johns
Hopkins University School of Medicine, Baltimore, MD 21205
| | - Geneviève Dom
- Institute of Anatomy, Department of Cell
Biology, University of Aarhus, DK-8000 Aarhus C, Denmark;
Division of Nephrology, Medical School, and
Christian de Duve Institute of Cellular
Pathology, Cell Unit, Université Catholique de Louvain, B-1200
Brussels, Belgium; Institut National de la
Santé et de la Recherche Médicale, U538, Centre
Hospitalo-Universitaire Saint Antoine, F-75012 Paris, France; and
Departments of Physiology and Medicine, The Johns
Hopkins University School of Medicine, Baltimore, MD 21205
| | - Rikke Nielsen
- Institute of Anatomy, Department of Cell
Biology, University of Aarhus, DK-8000 Aarhus C, Denmark;
Division of Nephrology, Medical School, and
Christian de Duve Institute of Cellular
Pathology, Cell Unit, Université Catholique de Louvain, B-1200
Brussels, Belgium; Institut National de la
Santé et de la Recherche Médicale, U538, Centre
Hospitalo-Universitaire Saint Antoine, F-75012 Paris, France; and
Departments of Physiology and Medicine, The Johns
Hopkins University School of Medicine, Baltimore, MD 21205
| | - Patrick Van Der Smissen
- Institute of Anatomy, Department of Cell
Biology, University of Aarhus, DK-8000 Aarhus C, Denmark;
Division of Nephrology, Medical School, and
Christian de Duve Institute of Cellular
Pathology, Cell Unit, Université Catholique de Louvain, B-1200
Brussels, Belgium; Institut National de la
Santé et de la Recherche Médicale, U538, Centre
Hospitalo-Universitaire Saint Antoine, F-75012 Paris, France; and
Departments of Physiology and Medicine, The Johns
Hopkins University School of Medicine, Baltimore, MD 21205
| | - Pierre Verroust
- Institute of Anatomy, Department of Cell
Biology, University of Aarhus, DK-8000 Aarhus C, Denmark;
Division of Nephrology, Medical School, and
Christian de Duve Institute of Cellular
Pathology, Cell Unit, Université Catholique de Louvain, B-1200
Brussels, Belgium; Institut National de la
Santé et de la Recherche Médicale, U538, Centre
Hospitalo-Universitaire Saint Antoine, F-75012 Paris, France; and
Departments of Physiology and Medicine, The Johns
Hopkins University School of Medicine, Baltimore, MD 21205
| | - Michèle Leruth
- Institute of Anatomy, Department of Cell
Biology, University of Aarhus, DK-8000 Aarhus C, Denmark;
Division of Nephrology, Medical School, and
Christian de Duve Institute of Cellular
Pathology, Cell Unit, Université Catholique de Louvain, B-1200
Brussels, Belgium; Institut National de la
Santé et de la Recherche Médicale, U538, Centre
Hospitalo-Universitaire Saint Antoine, F-75012 Paris, France; and
Departments of Physiology and Medicine, The Johns
Hopkins University School of Medicine, Baltimore, MD 21205
| | - William B. Guggino
- Institute of Anatomy, Department of Cell
Biology, University of Aarhus, DK-8000 Aarhus C, Denmark;
Division of Nephrology, Medical School, and
Christian de Duve Institute of Cellular
Pathology, Cell Unit, Université Catholique de Louvain, B-1200
Brussels, Belgium; Institut National de la
Santé et de la Recherche Médicale, U538, Centre
Hospitalo-Universitaire Saint Antoine, F-75012 Paris, France; and
Departments of Physiology and Medicine, The Johns
Hopkins University School of Medicine, Baltimore, MD 21205
| | - Pierre J. Courtoy
- Institute of Anatomy, Department of Cell
Biology, University of Aarhus, DK-8000 Aarhus C, Denmark;
Division of Nephrology, Medical School, and
Christian de Duve Institute of Cellular
Pathology, Cell Unit, Université Catholique de Louvain, B-1200
Brussels, Belgium; Institut National de la
Santé et de la Recherche Médicale, U538, Centre
Hospitalo-Universitaire Saint Antoine, F-75012 Paris, France; and
Departments of Physiology and Medicine, The Johns
Hopkins University School of Medicine, Baltimore, MD 21205
- To whom correspondence should be addressed. E-mail:
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62
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Seral C, Van Bambeke F, Tulkens PM. Quantitative analysis of gentamicin, azithromycin, telithromycin, ciprofloxacin, moxifloxacin, and oritavancin (LY333328) activities against intracellular Staphylococcus aureus in mouse J774 macrophages. Antimicrob Agents Chemother 2003; 47:2283-92. [PMID: 12821480 PMCID: PMC161849 DOI: 10.1128/aac.47.7.2283-2292.2003] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Using J774 macrophages, the intracellular activities of gentamicin, azithromycin, telithromycin, ciprofloxacin, moxifloxacin, and oritavancin (LY333328) against Staphylococcus aureus (strain ATCC 25923) have been quantitatively assessed in a 24-h model. S. aureus was positively localized in phagolysosomes by confocal and electron microscopy, and extracellular growth was prevented with 0.5 mg of gentamicin/liter (1x MIC) in controls. When tested at extracellular concentrations equivalent to their maximum concentrations in human serum, all antibiotics except azithromycin caused a significant reduction of the postphagocytosis inoculum within 24 h, albeit to markedly different extents (telithromycin [2 mg/liter], 0.60 log; ciprofloxacin [4.3 mg/liter], 0.81 log; gentamicin [18 mg/liter], 1.21 log; moxifloxacin [4 mg/liter], 1.51 log; oritavancin [25 mg/liter], 3.49 log). Intracellular activities were not systematically related to drug accumulation (apparent cellular-to-extracellular concentration ratios in infected cells: ciprofloxacin, 3.2; gentamicin, 6.8; telithromycin, 8.7; moxifloxacin, 13.4; azithromycin, 50; oritavancin, 348). Intracellular activity was not directly correlated to extracellular activity as measured in broth. Conditions of pH 5 (i.e., mimicking that of phagolysosomes) markedly reduced the activity of gentamicin, azithromycin, and telithromycin (>or=32 x) and fairly extensively reduced that of ciprofloxacin and moxifloxacin (>or=4 x) but did not affect oritavancin activity. We conclude that the cellular accumulation of antibiotics is not the only parameter to take into account for intracellular activity but that local environmental conditions (such as pH) and other factors can also prove critical.
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Affiliation(s)
- Cristina Seral
- Unité de Pharmacologie Cellulaire et Moléculaire, Université Catholique de Louvain, Brussels, Belgium
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63
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Fuller KM, Arriaga EA. Analysis of individual acidic organelles by capillary electrophoresis with laser-induced fluorescence detection facilitated by the endocytosis of fluorescently labeled microspheres. Anal Chem 2003; 75:2123-30. [PMID: 12720351 DOI: 10.1021/ac026476d] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Submicrometer-sized fluorescent microspheres were loaded into the acidic organelles of NS-1 mouse myeloma cells via endocytosis. Confocal microscopy imaging showed that microspheres colocalized nearly perfectly with LysoTracker Red, a probe that stains acidic organelles. Unlike LysoTracker dyes that seem to leak from acidic organelles upon cell disruption, microspheres are retained within these organelles, facilitating their analysis following isolation. Using capillary electrophoresis (CE) with laser-induced fluorescence detection (LIF), the electrophoretic mobilities of acidic organelles were individually calculated and fluorescence intensities individually measured. When cells were incubated for sufficient time to allow for endocytosis (48 h) with 3.9 x 10(3) microspheres/cell, replicate CE-LIF analyses of the corresponding isolated fraction indicated a dramatic increase in the number of detected events (n = 1990 +/- 234) and in the overall fluorescence intensity of the individual events (0.38 +/- 0.01 RFU; average +/- SD; n = 3) over the corresponding <10-min incubations (n = 60; 0.21 RFU, respectively). In addition, a treatment with 4-fold increase in microsphere density (1.6 x 10(4) microspheres/cell), increased the number of detected individual events (n = 3427 +/- 101) and altered only slightly the fluorescence intensity and electrophoretic mobility distributions. The individual electrophoretic mobility values ranged from -1.45 x 10(-)(4) to -3.0 x 10(-)(4) cm(2) V(-)(1) s(-)(1) while the individual fluorescence values ranged from 0.1 V to over 8 V, demonstrating the benefit of detecting organelles individually rather than averaging their properties over single cells or bulk homogenates.
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Affiliation(s)
- Kathryn M Fuller
- Department of Chemistry, University of Minnesota, Minneapolis 55455, USA
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64
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Tyteca D, Schanck A, Dufrêne YF, Deleu M, Courtoy PJ, Tulkens PM, Mingeot-Leclercq MP. The macrolide antibiotic azithromycin interacts with lipids and affects membrane organization and fluidity: studies on Langmuir-Blodgett monolayers, liposomes and J774 macrophages. J Membr Biol 2003; 192:203-15. [PMID: 12820665 DOI: 10.1007/s00232-002-1076-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The macrolide antibiotic azithromycin was shown to markedly inhibit endocytosis. Here we investigate the interaction of azithromycin with biomembranes and its effects on membrane biophysics in relation to endocytosis. Equilibrium dialysis and 31P NMR revealed that azithromycin binds to lipidic model membranes and decreases the mobility of phospholipid phosphate heads. In contrast, azithromycin had no effect deeper in the bilayer, based on fluorescence polarization of TMA-DPH and DPH, compounds that, respectively, explore the interfacial and hydrophobic domains of bilayers, and it did not induce membrane fusion, a key event of vesicular trafficking. Atomic force microscopy showed that azithromycin perturbed lateral phase separation in Langmuir-Blodgett monolayers, indicating a perturbation of membrane organization in lateral domains. The consequence of azithromycin/ phospholipid interaction on membrane endocytosis was next evaluated in J774 macrophages by using three tracers with different insertion preferences inside the biological membranes and intracellular trafficking: C6-NBD-SM, TMA-DPH and N-Rh-PE. Azithromycin differentially altered their insertion into the plasma membrane, slowed down membrane trafficking towards lysosomes, as evaluated by the rate of N-Rh-PE self-quenching relief, but did not affect bulk membrane internalization of C6-NBD-SM and TMA-DPH. Azithromycin also decreased plasma membrane fluidity, as shown by TMA-DPH fluorescence polarization and confocal microscopy after labeling by fluorescent concanavalin A. We conclude that azithromycin directly interacts with phospholipids, modifies biophysical properties of membrane and affects membrane dynamics in living cells. This antibiotic may therefore help to elucidate the physico-chemical properties underlying endocytosis.
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Affiliation(s)
- D Tyteca
- Unité de Pharmacologie Cellulaire et Moléculaire, Université Catholique de Louvain, Brussels, Belgium
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65
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Seral C, Michot JM, Chanteux H, Mingeot-Leclercq MP, Tulkens PM, Van Bambeke F. Influence of P-glycoprotein inhibitors on accumulation of macrolides in J774 murine macrophages. Antimicrob Agents Chemother 2003; 47:1047-51. [PMID: 12604540 PMCID: PMC149288 DOI: 10.1128/aac.47.3.1047-1051.2003] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The influence of inhibitors of P-glycoprotein (verapamil [VE], cyclosporine [CY], and GF120918 [GF]) on the cell handling of macrolides (erythromycin [ERY], clarithromycin [CLR], roxithromycin [ROX], azithromycin [AZM], and telithromycin [TEL]) was examined in J774 murine macrophages. The net influx rates of AZM and TEL were increased from 2- to 3.5-fold in the presence of these inhibitors, but their efflux was slowed only marginally. At 3 h, the inhibitors increased the levels of AZM, ERY, and TEL accumulation approximately three- to fourfold (the effect of VE, however, was lower) but did not influence CLR accumulation (the inhibitors had an intermediate behavior on ROX accumulation). The effect was concentration dependent (half-maximal increases in the level of accumulation of AZM were obtained with GF, CY, and VE at 0.5, 5, and 10 micro M, respectively). ATP depletion also caused an approximately threefold increase in the level of accumulation of AZM. Two inhibitors of MRP (probenecid [2.5 mM] and gemfibrozil [0.25 mM]) had no effect. Monensin (a proton ionophore) completely suppressed the accumulation of AZM in control cells as well as in cells incubated in the presence of VE, demonstrating that transmembrane proton gradients are the driving force causing the accumulation of AZM in both cases. Yet, VE did not alter the pH of the lysosomes (approximately 5) or of the cytosol (approximately 7.1). P-glycoprotein was detected by immunostaining at the cell surface as well as in intracellular vacuoles (endosomes and lysosomes). The data suggest that the influx of AZM, ERY, TEL, and ROX is adversely influenced by the activity of P-glycoprotein in J774 macrophages, resulting in suboptimal drug accumulation.
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Affiliation(s)
- Cristina Seral
- Unité de Pharmacologie Cellulaire et Moléculaire, Université Catholique de Louvain, Brussels, Belgium
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