Mechanism of cell protrusion formation in electrical field: the role of actin

Popov, Sergey; Svitkina, T.M.; Margolis, Leonid; Tsong, Tian Yow

doi:10.1016/0005-2736(91)90181-7

Cited by 18 publications

(13 citation statements)

References 23 publications

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“…The abnormal formation of microvilli, which at very long times of exposure can show lamellar or foamy shape, is in line with what is described by other authors [Popov et al, 1991;Chionna et al, 2003] and with the recently formulated general concept of regulation of ion and substrate pathways by microvilli. The actin-based core of microfilaments in microvilli has been proposed to represent a cellular interaction site for MFs [Gartzke and Lange, 2002].…”

Section: Discussionsupporting

confidence: 66%

“…Indeed, dramatic differences in the morphology of HepG2, U937, HeLa cells and lymphocytes after a short or a long time exposure to 6 mT static MF were described. Since high MFs in vitro promoted cytoskeleton reorganisation by assembling their component and by modulating their orientation [Bras et al, 1998], it is likely that these cytoskeleton modifications induced changes of cell shape [Popov et al, 1991;Santoro et al, 1997;Chionna et al, 2003]. Indeed, modulation of the Ca 2þ influx could also promote modifications of the cell shape, since the mechanism of reorganisation and breakdown of different cytoskeleton elements (polimerisation of F-actin is Ca 2þ dependent) is related to modified Ca 2þ homeostasis or altered phosphorylation/ dephosphorylation.…”

Section: Discussionmentioning

confidence: 99%

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Biological effects of 6 mT static magnetic fields: A comparative study in different cell types

Tenuzzo¹,

Chionna²,

Panzarini³

et al. 2006

Bioelectromagnetics

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The present work was a comparative study of the bio-effects induced by exposure to 6 mT static magnetic field (MF) on several primary cultures and cell lines. Particular attention was dedicated to apoptosis. Cell viability, proliferation, intracellular Ca(2+) concentration and morphology were also examined. Primary cultures of human lymphocytes, mice thymocytes and cultures of 3DO, U937, HeLa, HepG2 and FRTL-5 cells were grown in the presence of 6 mT static MF and different apoptosis-inducing agents (cycloheximide, H(2)O(2), puromycin, heat shock, etoposide). Biological effects of static MF exposure were found in all the different cells examined. They were cell type-dependent but apoptotic inducer-independent. A common effect of the exposure to static MF was the promotion of apoptosis and mitosis, but not of necrosis or modifications of the cell shape. Increase of the intracellular levels of Ca(2+) ions were also observed. When pro-apoptotic drugs were combined with static MF, the majority of cell types rescued from apoptosis. To the contrary, apoptosis of 3DO cells was significantly increased under simultaneous exposure to static MF and incubation with pro-apoptotic drugs. From these data we conclude that 6 mT static MF exposure interfered with apoptosis in a cell type- and exposure time-dependent manner, while the effects of static MF exposure on the apoptotic program were independent of the drugs used.

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Section: Discussionsupporting

confidence: 66%

Section: Discussionmentioning

confidence: 99%

Biological effects of 6 mT static magnetic fields: A comparative study in different cell types

Tenuzzo¹,

Chionna²,

Panzarini³

et al. 2006

Bioelectromagnetics

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“…The first consequence of the interaction of an electric field with a lipid vesicle is its deformation from a quasispherical shape to an ellipsoidal one. Experimentally, shape deformation was observed only in lipid vesicles and never reported in cells, except when repetitive pulses were applied (Chang and Reese, 1990;Popov et al, 1991;Riske and Dimova, 2005;Tekle et al, 2001). In particular, an intense alternating current electric field can induce formation of cell protrusions.…”

Section: Discussionmentioning

confidence: 95%

“…In particular, an intense alternating current electric field can induce formation of cell protrusions. Membrane-applied force is sufficient to produce nativelike cell protrusions: actin microfilaments can be organized into bundles directly under the action of membrane-applied force even in conditions where activity of the cytoskeleton is inhibited (Popov et al, 1991). On the other hand, it is known that electroporation transforms discocytic erythrocytes into echinocytes (Henszen et al, 1997).…”

Section: Discussionmentioning

confidence: 99%

Ultrastructural modifications of cell membranes induced by “electroporation” on melanoma xenografts

Spugnini¹,

Arancia²,

Porrello³

et al. 2007

Microscopy Res & Technique

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Electroporation (EP) has been widely employed in the past years as a safe and effective technique to drive drugs and DNA plasmids into target cells both for experimental and therapeutic purposes. Despite the large bulk of literature on this topic, often describing successful outcomes, there is a lack of knowledge about the intimate mechanism(s) controlling this phenomenon. In this paper, we describe a number of ultrastructural alterations in the cellular membranes following the exposure of orthotopic melanomas and red blood cells to trains of biphasic pulses. Specifically, melanoma xenografts grown in nude mice were subject to trains of eight biphasic pulses using an electric field of 1250 or 2450 V/cm, excised after 5 min and processed for electron microscopy. The freeze-fracturing analysis of both cell types evidenced defects in the dynamic assembly of lipids and proteins, which generate "areas with rough structure" and intensive clustering of intramembrane proteins. Such modifications could be the hallmarks of lipid and protein alterations, of protein cohesion reduction, and of changes in lipid orientation inside cell membranes, as postulated in several mathematical models applied to electroporation, and warrant further investigations.

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“…The modified [Ca 2? ]i homeostasis or the altered phosphorylation/dephosphorylation state of proteins in exposed cells, that leads to the reorganisation and breakdown of different cytoskeleton elements, interfered in turn with its normal morphology [146,176,178,179]. By now, no information are available on the effect of SMF on cell dying with autophagy.…”

Section: Cell Deathmentioning

confidence: 93%

Phagocytosis of dying cells: influence of smoking and static magnetic fields

Dini

2010

Apoptosis

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It is becoming evident that failure in the removal of dying cells causes and/or promotes the onset of chronic diseases. Impairment of phagocytosis of apoptotic cells can be due not only to genetic or molecular malfunctioning but also to external/environmental factors. Two of these environmental factors have been recently reported to down regulate the clearance of apoptotic cells: cigarette smoke and static magnetic fields. Cigarette smoke contains highly reactive carbonyls that modify proteins which directly/indirectly affects cellular function. Human macrophages interacting with carbonyl or cigarette smoke modified extracellular matrix (ECM) proteins dramatically down regulated their ability to phagocytose apoptotic neutrophils. It was postulated that changes in the ECM environment as a result of cigarette smoke affect the ability of macrophages to remove apoptotic cells. This decreased phagocytic activity was as a result of sequestration of receptors involved in the uptake of apoptotic cells towards that of recognition of carbonyl adducts on the modified ECM proteins leading to increased macrophage adhesion. Downregulation of the phagocytosis of apoptotic cells was also described when performed in presence of static magnetic fields (SMFs) of moderate intensity. SMFs have been reported to perturb distribution of membrane proteins and glycoproteins, receptors, cytoskeleton and trans-membrane fluxes of different ions, especially calcium [Ca(2+)]i, that in turn, interfere with many different physiological activities, including phagocytosis. The effects of cigarette smoke and SMF on the phagocytosis of dying cells will be here discussed.

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Mechanism of cell protrusion formation in electrical field: the role of actin

Cited by 18 publications

References 23 publications

Biological effects of 6 mT static magnetic fields: A comparative study in different cell types

Biological effects of 6 mT static magnetic fields: A comparative study in different cell types

Ultrastructural modifications of cell membranes induced by “electroporation” on melanoma xenografts

Phagocytosis of dying cells: influence of smoking and static magnetic fields

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