NADPH oxidase 4
NADPH oxidase 4 gene is mapped on chromosome 11q14.2-q21 upregulated in lungs to non-infectious injury and idiopathic pulmonary fibrosis. It functions as an oxygen sensor regulating the KCNK3 potassium channel and HIF1A activity and regulates insulin signaling cascade as well as role in apoptosis, bone resorption and lipopolysaccharide-mediated activation of NFKB.
NADPH oxidase 4 is highly expressed at the distal tubular cells in kidney cortex with a lower amount in heart, hepatoma, adipocytes, endothelial cells, skeletal muscle, brain, brain tumor cell lines and airway epithelial cells that appear to localized at central adhesion within the nucleus or in the endoplasmic reticulum thus constitutively active to functions in resting cellular homeostasis. It produces superoxide in the nucleus and play in regulating gene expression upon cell stimulation.
NADPH oxidase 4 has been implicated in the differentiation of cardiac fibroblasts to myofibroblasts and of the most induced genes in fetal lung mesenchymal cells stimulated with TGF-beta 1. It is important in tissue fibrogenesis and offers evidence for therapeutic targeting of NOX4 in recalcitrant fibrotic disorders.
Gene name: NOX4
Protein name: NADPH oxidase 4