Project description:The regulation of protein function by reversible oxidation is increasingly recognized as a key mechanism for the control of cellular signalling, modulating crucial biological processes such cell differentiation. In this scenario, the NADPH oxidases must occupy a prominent position. Our results show that haematopoietic stem and progenitor cells (HSPCs) express three p22phox-dependent NADPH oxidases members (Nox1, Nox2 and Nox4). By deleting the p22phox coding gene (Cyba), here we have analysed the importance of this family of enzymes during in vivo haematopoiesis. Cyba-/- mice show a myeloid bias in detriment of B-cells differentiation, and an enrichment of HSPCs populations. By means of haematopoietic transplant experiments we have also tried to dissect the specific role of the NADPH oxidases. While the absence of Nox1 or Nox2 provides an advantage of reconstitution, the lack of Nox4 rendered the opposite result, what suggests a functional specificity among the different NADPH oxidases. Regarding signalling pathways, the activation of AKT and STAT5 is hampered in Cyba-/- cells, the later due to the downregulation of STAT5 protein. This is in line with the diminished response to IL-7 shown by our results, what could explain defective B-cells development observed in Cyba-/- mice, supporting the requirement of NADPH oxidase activity for terminal B-cell differentiation.
Project description:NADPH oxidases are the only know enzyme family that has reactive oxygen species (ROS, e.g. superoxide and hydrogen peroxide) as their main metabolic product. They are therefore a prima candidate gene family to define a molecular source for ROS in physiology and pathophysiology. The type 4 NADPH oxidase (NOX4) is the most abundant isoform with the highest basal expression levels.The Nox4 knockout mouse was designed using a cre/lox recombination technique which allows to create either constitutive (type III recombination) and conditional (type I recombination) knockout alleles. cDNA microarray experiments of brain, kidney, muscle and pancreas of four male mutant mice versus a RNA pool of four male wild type mice. For each animal two technical replicates were performed including a dye swap experiment. All animals with the same age of 17 weeks on a C57BL/6 background.
Project description:NADPH oxidases are the only know enzyme family that has reactive oxygen species (ROS, e.g. superoxide and hydrogen peroxide) as their main metabolic product. They are therefore a prima candidate gene family to define a molecular source for ROS in physiology and pathophysiology. The type 4 NADPH oxidase (NOX4) is the most abundant isoform with the highest basal expression levels.The Nox4 knockout mouse was designed using a cre/lox recombination technique which allows to create either constitutive (type III recombination) and conditional (type I recombination) knockout alleles.
Project description:Within the family of NADPH oxidases, Nox4 is unique as it is predominantly localized in the endoplasmic reticulum, has constitutive activity and generates H2O2. We hypothesize that these features are consequences of a so far unidentified Nox4-interacting protein. Interacting proteins were screened by quantitative SILAC-Co-immunoprecipitation in HEK293 cells stably overexpressing Nox4. By this technique, several interacting proteins were identified with calnexin showing the most robust interaction.
Project description:Within the family of NADPH oxidases, Nox4 is unique as it is predominantly localized in the endoplasmic reticulum, has constitutive activity and generates H2O2. We hypothesize that these features are consequences of a so far unidentified Nox4-interacting protein. Interacting proteins were screened by quantitative SILAC-Co-immunoprecipitation in HEK293 cells stably overexpressing Nox4. By this technique, several interacting proteins were identified with calnexin showing the most robust interaction.
Project description:Hypoxic stress is a feature of rapidly growing thyroid tumors. Cancer progression is thought to be driven by reactive oxygen species (ROS) induced hypoxia adaptation. NADPH oxidases (NOXs), which produce ROS as their primary and sole function, has become of particular interest in thyroid malignancy. NOX4 was demonstrated to be upregulated in papillary thyroid cancers, functioning as a mitochondrial energetic sensor to modulate ATP levels, mediating overproduction of ROS induced by IL-δ, inversely correlating to thyroid differentiation. In this study, we analyzed hypoxia-treated BCPAP cells transfected with siRNA against NOX4. Results provides insight into the role of NOX4 in hypoxia adaptation.
Project description:Within the family of NADPH oxidases, Nox4 is unique as it is predominantly localized in the endoplasmic reticulum, has constitutive activity and generates H2O2. We hypothesize that these features are consequences of a so far unidentified Nox4-interacting protein. Blue native gel electrophoresis of solubilized membranes from HEK293 cells (overexpressing Nox4) separated macromolecular complexes containing Nox4. The combination of native gel electrophoresis and quantitative mass spectrometry was applied to identify proteins that co-migrate with Nox4. In addition, the data set contains information about macromolecular protein complexes in human cellular membranes that are stable to the solubilization with digitonin.
Project description:NOX1 is a catalytic subunit of nonphagocytic NADPH oxidase, mainly localized to smooth muscle cells in the vasculature. We investigated the pathology underlying the pulmonary arterial hypertension-like phenotype demonstrated in mice deficient in the Nox1 gene (Nox1-KO). Spontaneous enlargement and hypertrophy of the right ventricle, accompanied by hypertrophy of pulmonary vessels, were demonstrated in Nox1-KO at 9-18 weeks of age. Since an increased number of α-smooth muscle actin-positive vessels was observed in Nox1-KO, pulmonary arterial smooth muscle cells (PASMCs) were isolated and characterized by flow cytometry and TUNEL staining. In Nox1-/Y PASMC, the number of apoptotic cells was significantly reduced without any change in the expression of endothelin-1, and hypoxia-inducible factors HIF-1a and HIF-2a, factors implicated in the pathogenesis of PAH. microRNA expression profiling of mouse pulmonary arterial smooth muscle cells in wild-type and NOX1-KO was analyzed.
Project description:NOX1 is a catalytic subunit of nonphagocytic NADPH oxidase, mainly localized to smooth muscle cells in the vasculature. We investigated the pathology underlying the pulmonary arterial hypertension-like phenotype demonstrated in mice deficient in the Nox1 gene (Nox1-KO). Spontaneous enlargement and hypertrophy of the right ventricle, accompanied by hypertrophy of pulmonary vessels, were demonstrated in Nox1-KO at 9-18 weeks of age. Since an increased number of ?-smooth muscle actin-positive vessels was observed in Nox1-KO, pulmonary arterial smooth muscle cells (PASMCs) were isolated and characterized by flow cytometry and TUNEL staining. In Nox1-/Y PASMC, the number of apoptotic cells was significantly reduced without any change in the expression of endothelin-1, and hypoxia-inducible factors HIF-1a and HIF-2a, factors implicated in the pathogenesis of PAH. microRNA expression profiling of mouse pulmonary arterial smooth muscle cells in wild-type and NOX1-KO was analyzed. Pulmonary arterial smooth muscle cells were harvested form 3 mice.