Nuclear factor-kappaB regulates the transcription of NADPH oxidase 1 in human alveolar epithelial cells

Abstract

Objective Acute lung injury (ALI) is characterized by inflammation and oxidative stress. Nuclear factor-kappaB (NF-κB) mediates the expression of various inflammation-related genes, including the NADPH oxidase family. This study aimed to identify the potential regulatory role of NF-κB on NADPH oxidases in tumor necrosis factor-α (TNF-α)-induced oxidative stress in human alveolar epithelial cells. Methods A549 cells were treated with TNF-α for 24 h to establish ALI cell models. RT-PCR, western blot, assessment of oxidative stress, Alibaba 2.1 online analysis, electrophoretic mobility shift assays and luciferase reporter analysis were employed to identify the potential regulatory role of NF-κB on NADPH oxidases in TNF-α-induced oxidative stress in human alveolar epithelial cells. Results The expression of NF-κB/p65 was notably upregulated in TNF-α-stimulated A549 cells. NF-κB knockdown by siRNA significantly inhibited the TNF-α-induced oxidative stress. Moreover, NF-κB/p65 siRNA could inhibit the activation of NOX1, NOX2 and NOX4 mRNA and protein expression in TNF-α-stimulated A549 cells. The next study demonstrated that NF-κB activated the transcription of NOX1 by binding to the -261 to -252 bp (NOX1/κB2, TAAAAATCCC) region of NOX1 promoter in TNF-α-stimulated A549 cells. Conclusion Our data demonstrated that NF-κB can aggravate TNF-α-induced ALI by regulating the oxidative stress response and the expression of NOX1, NOX2 and NOX4. Moreover, NF-κB could promote the NOX1 transcriptional activity via binding its promoter in TNF-α-stimulated A549 cells.

NADPH oxidase and endoplasmic reticulum stress is associated with neuronal degeneration in orbitofrontal cortex of individuals with alcohol use disorder

“…Our laboratory and others report upregulation of proinflammatory TLRs, the endogenous TLR agonist HMGB1, and downstream activation of the nuclear transcription factor RELA leading to cytokine and chemokine signalling in the post‐mortem OFC of individuals with AUD 3,7,48–50 . In addition to driving proinflammatory cytokine and chemokine induction, activation and nuclear translocation of RELA induces transcription of NF‐κB subunits and proinflammatory genes, including NADPH oxidases and ROS 15,51,52 . Preclinical models link ethanol‐ and proinflammatory TLR4‐induced activation of NF‐κB to generation of proinflammatory NADPH oxidases (i.e., NOX2) and ROS that is blocked in NOX2 −/− knockout mice as well as by treatment with the NOX inhibitor diphenyliodonium 1,16 .…”

“… 3 , 7 , 48 , 49 , 50 In addition to driving proinflammatory cytokine and chemokine induction, activation and nuclear translocation of RELA induces transcription of NF‐κB subunits and proinflammatory genes, including NADPH oxidases and ROS. 15 , 51 , 52 Preclinical models link ethanol‐ and proinflammatory TLR4‐induced activation of NF‐κB to generation of proinflammatory NADPH oxidases (i.e., NOX2) and ROS that is blocked in NOX2 −/− knockout mice as well as by treatment with the NOX inhibitor diphenyliodonium. 1 , 16 NADPH oxidase‐mediated oxidative stress is implicated in many neurological diseases, 53 , 54 but the role of AUD‐induced oxidative stress in the human central nervous system (CNS), with the exception of NOX2, 1 is largely unknown.…”

Role Of The C-C Motif Chemokine Ligand 5 (CCL5) And Its Receptor, C-C Motif Chemokine Receptor 5 (CCR5) In The Genesis Of Aldosterone-induced Hypertension, Vascular Dysfunction, And End-organ Damage

“…NADPH oxidases are the major source of ROS in the vasculature and have been implicated in vascular dysfunction, inflammation, and remodeling by regulating NFκB, an important redox sensitive transcript factor, which regulates multiple inflammatory genes 59 . Furthermore, others have reported that NFκB can also regulate NADPH oxidase expression 40, 60 indicating positive feedback between NADPH oxidases and NFκB.…”

Differential Effects of Betacyanin and Betaxanthin Pigments on Oxidative Stress and Inflammatory Response in Murine Macrophages

“…Similarly, Tesoriere et al [7] found that 25 μM IDX prevented activation of NOX-1 complex resulting in reduced levels of cytosolic NOX-1 in IL-1𝛽-stimulated intestinal Caco-2 cells. Members of the NOX family, i.e., NOX-2, are modulated by NF-𝜅B transcription factor, [47] which explains the alignment of outcomes with inflammatory markers. Interference with NF-𝜅B signaling has also been shown by Manea et al [48] in TNF-𝛼 stimulated smooth muscle cells which is likely the case for all betalains, and in particular for betacyanins.…”