Nox1, a homologue of gp91(phox) subunit of the phagocyte NADPH oxidase, is responsible for spontaneous superoxide (O(2)(-)) generation in guinea pig gastric mucosal cells (GMC), but involvement of regulatory components (p67(phox), p47(phox), and Rac) which are essential in phagocytes remains unknown. Here, we aimed to figure out how Nox1 of GMC achieves an active oxidase status. GMC in primary ...

BACKGROUND Reactive oxygen species are involved in many of the angiotensin II signalling pathways. We have thus investigated whether the angiotensin II type 1 (AT1) receptor antagonist, telmisartan, can inhibit the accelerated renal fibrosis and excess oxidative stress, which occurs after unilateral ureteral obstruction (UUO) in acatalasemic mice. METHODS The effect of daily intraperitoneal i...

p67(phox) and gp91(phox) are components of the phagocyte-specific respiratory burst oxidase that are encoded by the NCF2 and CYBB genes, respectively. These genes are transcribed exclusively in myeloid cells that have differentiated beyond the promyelocyte stage. In mature phagocytes, NCF2 and CYBB transcription continues until cell death and further increases in response to IFN-gamma and other...

Hexavalent chromium [Cr(VI)] is a well-known human carcinogen associated with the incidence of lung cancer. Although overproduction of reactive oxygen species (ROS) has been suggested to play a major role in its carcinogenicity, the mechanisms of Cr(VI)-induced ROS production remain unclear. In this study, we investigated the role of NADPH oxidase (NOX), one of the major sources of cellular ROS...

Superoxide produced by the phagocyte reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is essential for host defense. Enzyme activation requires translocation of p67(phox), p47(phox), and Rac-GTP to flavocytochrome b558 in phagocyte membranes. To examine the regulation of phagocytosis-induced superoxide production, flavocytochrome b558, p47(phox), p67(phox), and the FcgammaIIA...

Defining the mechanisms of Mycobacterium tuberculosis (Mtb) persistence in the host macrophage and identifying mycobacterial factors responsible for it are keys to better understand tuberculosis pathogenesis. The emerging picture from ongoing studies of macrophage deactivation by Mtb suggests that ingested bacilli secrete various virulence determinants that alter phagosome biogenesis, leading t...

The role of Leu of Nox2 on the NADPH oxidase activation process was investigated. An X-CGD PLB-985 cell line expressing the Leu505Arg Nox2 mutant was obtained, exactly mimicking the phenotype of a previously published X91 CGD case. In a reconstituted cell-free system (CFS), NADPH oxidase and iodonitrotetrazolium (INT) reductase activities were partially maintained concomitantly with a partial c...