Leishmania amazonensis infection may affect the ability of the host macrophage to be activated by altering their outward potassium currents

Camacho, Marcela; Forero, María Elisa; Fajardo, Carolina; Niño, Andrea; Morales, Patrícia; Campos, Héctor Aníbal

doi:10.1016/j.exppara.2008.04.019

Cited by 14 publications

(28 citation statements)

References 40 publications

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“…Differences between some measurements of electrophysiological parameters may be related to cell culture conditions, though some authors argue that they represent genuine innate characteristics of currents expressed by macrophages (Randriamampita & Trautmann, 1987). Several studies support this hypothesis (Randriamampita & Trautmann, 1987;McKinney & Gallin, 1990;Forero et al, 1999;Camacho et al, 2008). In this view, variations in characterization are explained by differences in the ionic solutions used and the corresponding change to the Nernst equilibrium and the electrochemical force imposed on each ion, and of course by differences in the ion channel populations expressed (Vicente et al, 2006;Villalonga et al, 2007;Vicente et al, 2008).…”

Section: Macrophage Passive Membrane Propertiesmentioning

confidence: 75%

“…During classical activation, J774.A1 becomes larger and adds membrane (Camacho et al, 2008), but LPS alone surprisingly reduces this parameter in RAW 264.7 (Villalonga et al, 2010), suggesting reduction of surface area. In the Leishmania-macrophage model, evidence of reduction of endosomal and lysosomal compartments (Barbiéri et al, 1990) has been interpreted as a way to concentrate lysosomal activity into the PV to control the parasite.…”

Section: Macrophage Passive Membrane Propertiesmentioning

confidence: 99%

“…The lipid bilayer of the cell membrane can be modelled as a capacitor of two parallel conducting plates separated by a dielectric, so changes in Cm reflect direct changes in membrane area. Cm varies with postadherence time (McKinney & Gallin, 1990) and Leishmania amazonensis post-infection time (Forero et al, 1999;Camacho et al, 2008;Quintana et al, 2010). J774.A1 cells exposed to cytochrome C to induce apoptosis are smaller than control cells, but have a similar Cm (Clavijo et al, 2009) suggesting loss of volume without decrease in surface area.…”

Section: Macrophage Passive Membrane Propertiesmentioning

confidence: 99%

“…I OUT and I KIR have similar amplitudes after 24 hours post-adherence (Gallin & Sheehy, 1985), but after 48 hours the situation reverses, with predominant I KIR and negligible I OUT (McKinney & Gallin, 1990). We have therefore controlled for time of adherence onto glass in some of our experiments to guarantee similar amplitudes for I OUT and I KIR (Forero et al, 1999;Camacho et al, 2008;Quintana et al, 2010).…”

Section: Macrophage Passive Membrane Propertiesmentioning

confidence: 99%

“…Macrophage passive electrical membrane properties have been recorded in primary macrophages of mouse (Buisman et al, 1988;Vicente et al, 2003), man (Gallin & Gallin, 1977;Holevinsky & Nelson, 1998), various mouse (Randriamampita & Trautmann, 1987;Buisman et al, 1988;Holevinsky & Nelson, 1998;Gallin, 1991;Forero et al, 1999;Camacho et al, 2008;Quintana et al, 2010;Villalonga et al, 2010) and human (McCann et al, 1987) cell lines. Differences between some measurements of electrophysiological parameters may be related to cell culture conditions, though some authors argue that they represent genuine innate characteristics of currents expressed by macrophages (Randriamampita & Trautmann, 1987).…”

Section: Macrophage Passive Membrane Propertiesmentioning

confidence: 99%

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Electrical Membrane Properties in the Model Leishmania-Macrophage

Camacho¹

2012

Patch Clamp Technique

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Section: Macrophage Passive Membrane Propertiesmentioning

confidence: 75%

Section: Macrophage Passive Membrane Propertiesmentioning

confidence: 99%

Section: Macrophage Passive Membrane Propertiesmentioning

confidence: 99%

Section: Macrophage Passive Membrane Propertiesmentioning

confidence: 99%

Section: Macrophage Passive Membrane Propertiesmentioning

confidence: 99%

See 3 more Smart Citations

Electrical Membrane Properties in the Model Leishmania-Macrophage

Camacho¹

2012

Patch Clamp Technique

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Infection by Trypanosoma cruzi Enhances Anion Conductance in Rat Neonatal Ventricular Cardiomyocytes

et al. 2010

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Recent studies on malaria-infected erythrocytes have shown increased anion channel activity in the host cell membrane, increasing the exchange of solutes between the cytoplasm and exterior. In the present work, we addressed the question of whether another intracellular protozoan parasite, Trypanosoma cruzi, alters membrane transport systems in the host cardiac cell. Neonatal rat cardiomyocytes were cultured and infected with T. cruzi in vitro. Ion currents were measured by patch-clamp technique in the whole-cell configuration. Two small-magnitude instantaneous anion currents, outward- and inward-rectifying, were recorded in all noninfected cardiomyocytes. In addition, ~10% of cardiomyocytes expressed a large anion-preferable, time-dependent current activated at positive membrane potentials. Hypotonic (230 mOsm) treatment resulted in the disappearance of the time-dependent current but provoked a dramatic increase of the instantaneous outward-rectifying one. Both instantaneous currents were suppressed by intracellular Mg(2+). T. cruzi infection did not provoke new anion currents in the host cells but caused an increase of the density of intrinsic swelling-activated outward current, up to twice in heavily infected cells. The occurrence of a time-dependent current dramatically increased in infected cells in the presence of Mg(2+) in the intracellular solution, from ~10 to ~80%, without a significant change of the current density. Our findings represent one further, besides the known Plasmodium falciparum, example of an intracellular parasite which upregulates the anionic currents expressed in the host cell.

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Macrophage ion currents are fit by a fractional model and therefore are a time series with memory

2009

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We studied macroscopic ion currents from macrophages and compared their patterns of behavior using classical and fractal analysis. Peak and steady state currents were measured respectively at the beginning and end of a voltage-clamp pulse. Hurst coefficients H and fractional dimensions were calculated for the current fluctuations (I(H)) during the intervening interval; these fluctuations are usually assumed to be white noise. We show that I(H) is different from 0.5 and that the increments are stationary, indicating that the dynamic model has memory and that the intervening current fluctuations cannot be considered as white noise. I(H) is less than 0.5, implying an antipersistent pattern. In addition, we show that the relation between inactivation and I(H) versus voltage V fit an equation I(H)(V) = f(V, alpha, m, d), where alpha is associated with fractional calculus and m and d are free parameters. Fitting by a fractional model confirms that the phenomenon has memory.

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Leishmania amazonensis infection may affect the ability of the host macrophage to be activated by altering their outward potassium currents

Cited by 14 publications

References 40 publications

Electrical Membrane Properties in the Model Leishmania-Macrophage

Electrical Membrane Properties in the Model Leishmania-Macrophage

Infection by Trypanosoma cruzi Enhances Anion Conductance in Rat Neonatal Ventricular Cardiomyocytes

Macrophage ion currents are fit by a fractional model and therefore are a time series with memory

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