Vessel regions with predilection to atherosclerosis have negative wall shear stress due to flow reversal. The flow reversal causes the production of superoxides (O(2)(-)), which scavenge nitric oxide (NO), leading to a decrease in NO bioavailability and endothelial dysfunction. Here, we implicate NADPH oxidase as the primary source of O(2)(-) during full flow reversal. Nitrite production and th...

Reactive oxygen species (ROS) have been increasingly recognized as important components of cell signaling in addition to their well-established roles in host defense. The formation of ROS in phagocytic and nonphagocytic cells involves membrane-localized and Rac guanosine triphosphatase (GTPase)-regulated reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase(s). We discuss here the...

PURPOSE Cancer cells show higher levels of reactive oxygen species (ROS) than normal cells and increasing intracellular ROS levels are becoming a recognized strategy against tumor cells. Thus, diminishing ROS levels could be also detrimental to cancer cells. We surmise that avoiding ROS generation would be a better option than quenching ROS with antioxidants. Chronic myelogenous leukemia (CML) ...

Recently, we showed that cultured guinea pig gastric pit cells possess a phagocyte NADPH oxidase-like activity, which was up-regulated by Helicobacter pylori lipopolysaccharide. We demonstrate here that these cells express all of the phagocyte NADPH oxidase components (gp91-, p22-, p67-, p47-, and p40-phoxes). Treatment with lipopolysaccharide increased the expression of gp91-, p22-, and p67-ph...

In the hypothalamus, several reports have implied that ROS mediate physiological effects of insulin. In this study, we investigated the mechanisms of insulin-induced ROS production and the effect of ROS on insulin signal transduction in mouse hypothalamic organotypic cultures. Insulin increased intracellular ROS, which were suppressed by NADPH oxidase inhibitor. H2O2 increased phospho-insulin r...

Activity of the oxidative phosphorylation system (OXPHOS) is decreased in humans and mice with nonalcoholic steatohepatitis. Nitro-oxidative stress seems to be involved in its pathogenesis. The aim of this study was to determine whether fatty acids are implicated in the pathogenesis of this mitochondrial defect. In HepG2 cells, we analyzed the effect of saturated (palmitic and stearic acids) an...

We have shown that intracellular superoxide (O2 ) production in CNS neurons plays a key role in the pressor, bradycardic, and dipsogenic actions of Ang II in the brain. In this study, we tested the hypothesis that a Rac1-dependent NADPH oxidase is a key source of O2 in Ang II–sensitive neurons and is involved in these central Ang II–dependent effects. We performed both in vitro and in vivo stud...

Increased expression of cyclooxygenase (COX) 2 and the production of PGs appear to provide a survival advantage to transformed cells through the inhibition of apoptosis, increased attachment to extracellular matrix, increased invasiveness and the stimulation of angiogenesis. The purpose of this study was to determine whether an angiogenic antagonist, SU5416, could inhibit endogenous and phorbol...