Redox Changes of Cultured Endothelial Cells and Actin Dynamics

Abstract

Abstract-We studied the association between the production of reactive oxygen species, actin organization, and cellular motility. We have used an endothelial cell monolayer-wounding assay to demonstrate that the cells at the margin of the wound thus created produced significantly more free radicals than did cells in distant rows. The rate of incorporation of actin monomers into filaments was fastest at the wound margin, where heightened production of free radicals was detected. We have tested the effect of decreasing reactive oxygen species production on the migration of endothelial cells and on actin polymerization. The NADPH inhibitor diphenylene iodonium and the superoxide dismutase mimetic manganese (III) tetrakis(1-methyl-4-pyridyl)porphyrin (MnTMPyP) virtually abolished cytochalasin D-inhibitable actin monomer incorporation at the fast-growing barbed ends of filaments. Moreover, endothelial cell migration within the wound was significantly retarded in the presence of both diphenylene iodonium and MnTMPyP. We conclude that migration of endothelial cells in response to loss of confluence includes the intracellular production of reactive oxygen species, which contribute to the actin cytoskeleton reorganization required for the migratory behavior of endothelial cells. (Circ Res. 2000;86:549-557.)

Elevated superoxide production by active H-ras enhances human lung WI-38VA-13 cell proliferation, migration and resistance to TNF-α

“…Crawford et al (1996) demonstrated actin polymerization was concurrent with increased superoxide production in post-hypoxic endothelial cells. Moreover, endothelial cell migration in the wound was signi®cantly retarded in the presence of DPI or MnSOD mimetic (Moldovan et al, 2000). Activation of Rac has been shown to participate in actin polymerization and cell proliferation, suggesting that Rac-mediated superoxide production may contribute, at least partially, to cell proliferation and migration (Qiu et al, 1995;Joneson et al, 1996).…”

NADPH oxidases in lung biology and pathology: Host defense enzymes, and more

“…Using in vitro wound models in cultured airway epithelial systems, DUOX1 was found to play a critical role in cell migration as part of the wound repair response (87,108), illustrating an additional function of DUOX1 in maintenance of epithelial integrity. This is not a unique property of DUOX1, as other NOX isoforms have also been linked to proliferation and/or migration in various other cell types (70,71,116,117), pointing to a possible common mechanism by which NOX/DUOX activation promotes these processes.…”

“…Additionally, NOX-mediated effects on e.g. cell proliferation or migration also depend on strict spatial localization of NOX activation in association with the cytoskeleton (70,71) or in membrane rafts (43,72,73), and on direct interactions with target proteins (3,43,55). This allows for effective oxidative signaling in the presence of abundant cytosolic antioxidant mechanisms (Cu/Zn SOD, GSH peroxidase), and assures confined oxidant production and target specificity.…”

Small Rho GTPase-mediated actin dynamics at endothelial adherens junctions

“…89 ROS in turn increases vascular permeability by actin reorganization or by inactivating junction-associated phosphatases. 90,91 Moreover, VEGFinduced Rac1 activation has been demonstrated to be regulated by the GEF Vav2, leading to generation of ROS and VE-cadherin internalization. 25,92,93 We recently showed that the multi-domain GEF Trio interacts with VE-cadherin.…”