Characterization of missense mutations in the NADPH oxidase partner p22 in the A22° subtype of chronic granulomatous disease.

Defective superoxide production by NADPH oxidase 2 (Nox2) in phagocyte cells results in the development of chronic granulomatous disease (CGD), a hereditary disease characterized by recurrent and life-threatening infections. The partner protein p22 is a membrane-spanning protein which forms a stable heterodimer with Nox2 in the endoplasmic reticulum. This interaction ensures the stability of each protein and their accurate trafficking to the cell membrane.

Inhibition of pancreatic cancer-cell growth and metastasis in vivo by a pyrazole compound characterized as a cell-migration inhibitor by an in vitro chemotaxis assay.

Pancreatic cancer is recalcitrant to treatment as it is highly metastatic and rapidly progressive. While observing the behavior of human pancreatic BxPC-3 cells using an optical assay device called TAXIScan, we found that several synthetic pyrazole and pyrimidine derivatives inhibited cell migration. One such compound, 14-100, inhibited metastasis of fluorescence-labeled BxPC-3 cells, which were transplanted into the pancreas of nude mice as a subcutaneously grown cancer fragment.

Regulation of Derlin-1-mediated degradation of NADPH oxidase partner p22 by thiol modification.

The transmembrane protein p22 heterodimerizes with NADPH oxidase (Nox) 1-4 and is essential for the reactive oxygen species-producing capacity of oxidases. Missense mutations in the p22 gene prevent the formation of phagocytic Nox2-based oxidase, which contributes to host defense. This results in chronic granulomatous disease (CGD), a severe primary immunodeficiency syndrome.

The downregulation of NADPH oxidase Nox4 during hypoxia in hemangioendothelioma cells: a possible role of p22 on Nox4 protein stability.

NADPH oxidase (Nox) 4 produces HO by forming a heterodimer with p22 and is involved in hemangioendothelioma development through monocyte chemoattractant protein-1 (MCP-1) upregulation. Here, we show that Nox4 protein levels were maintained by p22 in hemangioendothelioma cells and Nox4 protein stability was dependent on p22 coexpression. Conversely, the degradation of Nox4 monomer was enhanced by p22 knockdown.

Fine definition of the epitopes on the human gp91/NOX2 for the monoclonal antibodies CL-5 and 48.

Superoxide-producing NADPH oxidase, gp91/NOX2, in phagocytes plays a critical role in the host defenses against pathogens. Moreover, gp91/NOX2 contributes to the oxidative stress in endothelial cells. Therefore, investigating the level of gp91/NOX2 with immunoblotting is important for estimating the amount of superoxide produced.

Coculture in vitro with endothelial cells induces cytarabine resistance of acute myeloid leukemia cells in a VEGF-A/VEGFR-2 signaling-independent manner.

An interaction between acute myeloid leukemia (AML) cells and endothelial cells in the bone marrow seems to play a critical role in chemosensitivity on leukemia treatment. The endothelial niche reportedly enhances the paracrine action of the soluble secretory proteins responsible for chemoresistance in a vascular endothelial growth factor A (VEGF-A)/VEGF receptor 2 (VEGFR-2) signaling pathway-dependent manner. To further investigate the contribution of VEGF-A/VEGFR-2 signaling to the chemoresistance of AML cells, a biochemical assay system in which the AML cells were cocultured with human endothelial EA.

Constitutive activity of NADPH oxidase 1 (Nox1) that promotes its own activity suppresses the colon epithelial cell migration.

Superoxide producing NADPH oxidase 1 (Nox1), abundantly expressed in the colon epithelium, plays a crucial role in mucosal host defenses. In this study, we found that pre-treatment of cells with edaravone, a free radical scavenger, inhibited Nox1 constitutive activity even after washout without affecting Nox1 trafficking to the plasma membrane and membrane recruitment of the cytosolic regulators Noxo1 and Noxa1. These results suggest that a Nox1-derived product is involved in the step that initiates the electron transfer reaction after the formation of the Nox1-Noxo1-Noxa1 complex.

The NADPH oxidase NOX4 promotes the directed migration of endothelial cells by stabilizing vascular endothelial growth factor receptor 2 protein.

Directed migration of endothelial cells (ECs) is an important process during both physiological and pathological angiogenesis. The binding of vascular endothelial growth factor (VEGF) to VEGF receptor-2 (VEGFR-2) on the EC surface is necessary for directed migration of these cells. Here, we used TAXIScan, an optically accessible real-time horizontal cell dynamics assay approach, and demonstrate that reactive oxygen species (ROS)-producing NADPH oxidase 4 (NOX4), which is abundantly expressed in ECs, mediates VEGF/VEGFR-2-dependent directed migration.

Monoclonal antibody 7D5 recognizes the R147 epitope on the gp91 , phagocyte flavocytochrome b large subunit.

Human phagocyte flavocytochrome b (Cyt b), the catalytic center of nicotinamide adenine dinucleotide phosphate oxidase, consists of a heavily glycosylated large subunit (gp91 ; Nox2) and a small subunit (p22 ). Cyt b is a membrane-spanning complex enzyme. Chronic granulomatous disease (CGD) is predominantly caused by a mutation in the CYBB gene encoding gp91 on the X-chromosome.

Histone acetyltransferase p300/CBP-associated factor is an effective suppressor of secretory immunoglobulin synthesis in immature B cells.

The histone acetyltransferase p300/CBP-associated factor (PCAF) catalyzes acetylation of core histones and plays important roles in epigenetics by altering the chromatin structure in vertebrates. In this study, PCAF-deficient DT40 mutants were analyzed and it was found that PCAF participates in regulation of secretory IgM heavy chain (H-chain) synthesis. Remarkably, PCAF-deficiency causes an increase in the amount of secretory IgM H-chain mRNA, but not in that of IgM light chain and membrane-bound IgM H-chain mRNAs, resulting in dramatic up-regulation of the amount of secretory IgM protein.

A novel mutation of human liver alanine:glyoxylate aminotransferase causes primary hyperoxaluria type 1: immunohistochemical quantification and subcellular distribution.

A novel alanine:glyoxylate aminotransferase (AGT) mutation involved in primary hyperoxaluria type 1 (PH1) was studied in Japanese patients. Two mutations in exon 7, c.751T>A and c.

A highly sensitive chemiluminescence assay for superoxide detection and chronic granulomatous disease diagnosis.

Reactive oxygen species (ROS) produced by neutrophils are crucial for defense against infectious diseases, and the adequate measurement of ROS levels is an important way to evaluate the possibility of infections. The fluorescent probe dihydrorhodamine 123 has been applied exclusively to the measurement of ROS thus far. We developed a novel method for detecting ROS, which utilizes the chemiluminescent probes Luminol and Diogenes.