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Cardiovascular Disease and Oxidative Stress
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2019
Marco Fernandes, Alisha Patel, Holger Husi
In vascular disease, NADPHox isoforms NOX1, NOX2, NOX4 and NOX5 are expressed in cellular components of arteries and veins, with their assembling site being primary in membranes of endothelial cells (ECs) and smooth muscle cells (SMCs), and can also be found in fibroblasts within connective tissue (Giardino et al., 2017). NOX1, NOX2 and NOX4 occur as multimeric protein complexes, thereby the process of electron transfer involves a NOX subunit and different-NOX-type regulatory elements (Drummond and Sobey, 2014). NOX2 regulatory subunits includes cytochrome b-245 light chain (p22phox, CYBA), neutrophil cytosol factor 2 (p67phox, NCF2), p47phox (NCF1), neutrophil cytosol factor 4 (p40phox, NCF4), and ras-related C3 botulinum toxin substrate 1 (RAC1) (Drummond and Sobey, 2014; Konior et al., 2014). NOX1 contains the same regulatory subunits as NOX2, but does not require p40phox to carry on its enzymatic activity (Konior et al., 2014). In vascular smooth muscle cells (VSMCs) an additional enhancer, the polymerase delta-interacting protein 2 (POLDIP2), binds to the NOX4-p22phox complex and increases its catalytic activity by 3-fold (Lyle et al., 2009) whereas NOX5 ability to produce ROS only requires calcium ions for modulation of its catalytic activity (Guzik et al., 2008). Most of the NOX enzymes are characterized by production, from the conversion of diatomic oxygen (O2) using NADPH as electron donors, NOX4 isoform seems to have as main end-product hydrogen peroxide (H2O2) (Konior et al., 2014).
“Clinical Aspects of Chronic Granulomatous Disease in Upper Egypt”
Published in Immunological Investigations, 2021
Mohamed A. El-Mokhtar, Eman H. Salama, Eman Mohamed Fahmy, Mona Embarek Mohamed
CGD is caused by mutations in one of the five genes coding for NADPH oxidase subunits. Approximately 70% of cases are caused by mutations in the CYBB gene leading to X-linked CGD, which often causes a severe form of the disease (Ko et al. 2014; van den Berg et al. 2009). More than 700 pathogenic mutations in the CYBB gene encoding the gp91-phox protein have been documented. Other biallelic mutations in CYBA, NCF1, NCF2, and NCF4 cause autosomal recessive CGD (Boonyawat et al. 2018). In addition to the previously described genes coding for NADPH oxidase, a novel ER-resident transmembrane protein called Eros (essential for reactive oxygen species) that is essential for the regulation of NADPH oxidase and controls the phagocyte respiratory burst was described. EROS is essential for the expression of gp91phox-p22phox heterodimer, which is one of the essential components of the phagocyte NADPH oxidase (Thomas et al. 2019, 2017). A homozygous CYBC1/EROS mutation was associated with the development of CGD (Monies et al. 2017).