Biochemical and Biophysical Research Communications
Regular ArticleOxidative Stress Induces NFκB DNA Binding and Inducible NOS mRNA in Human Epithelial Cells
Abstract
Free radicals generated by a partial reduction of O2 pose a serious threat to tissues and vital organs and cells. The major site of interaction between the lung and inhaled oxidants is the epithelium. We have examined the effect of pyrogallol, an O2- generator, on the ability of human epithelial cells to produce active DNA binding proteins and inducible nitric oxide synthase (iNOS) mRNA in cultured A549 epithelial cells. NFkB binding in the nuclei of these cells was determined by electrophoretic mobility shift assays. iNOS mRNA was measured using reverse transcription and PCR. There was a time- and concentration-dependent induction of NFkB binding, followed by a time and dose dependent increase in iNOS mRNA levels. These results suggest that in airways the initial response to oxidative stress may be to induce NFkB-responsive genes, such as iNOS, which may play an important role in defending the airway against oxidative stress.
References (0)
Cited by (255)
Fast regulation of the NF-κB signalling pathway in human skeletal muscle revealed by high-intensity exercise and ischaemia at exhaustion: Role of oxygenation and metabolite accumulation
2022, Redox BiologyCitation Excerpt :In contrast, the recovery of ATP, PCr and the abundance of oxygen during recovery with open circulation may have facilitated CaMKII deactivation by the phosphatases, leading to downregulation of part of NF-κB signalling within seconds after the cessation of contractile activity. Cell experiments have shown that NF-κB signalling may be stimulated by RONS [9,10,73–76] and hypoxia [21–23]. RONS are produced in skeletal during exercise depending on exercise characteristics, the energy substrates oxidized, and fitness status [28,77–80].
The NF-κB signalling pathway plays a critical role in inflammation, immunity, cell proliferation, apoptosis, and muscle metabolism. NF-κB is activated by extracellular signals and intracellular changes in Ca2+, Pi, H+, metabolites and reactive oxygen and nitrogen species (RONS). However, it remains unknown how NF-κB signalling is activated during exercise and how metabolite accumulation and PO2 influence this process. Eleven active men performed incremental exercise to exhaustion (IE) in normoxia and hypoxia (PIO2:73 mmHg). Immediately after IE, the circulation of one leg was instantaneously occluded (300 mmHg). Muscle biopsies from m. vastus lateralis were taken before (Pre), and 10s (Post, occluded leg) and 60s after exercise from the occluded (Oc1m) and free circulation (FC1m) legs simultaneously together with femoral vein blood samples. NF-κB signalling was activated by exercise to exhaustion, with similar responses in normoxia and acute hypoxia, as reflected by the increase of p105, p50, IKKα, IκBβ and glutathione reductase (GR) protein levels, and the activation of the main kinases implicated, particularly IKKα and CaMKII δD, while IKKβ remained unchanged. Postexercise ischaemia maintained and stimulated further NF-κB signalling by impeding muscle reoxygenation. These changes were quickly reverted at the end of exercise when the muscles recovered with open circulation. Finally, we have shown that Thioredoxin 1 (Trx1) protein expression was reduced immediately after IE and after 1 min of occlusion while the protein expression levels of glutathione peroxidase 1 (Gpx1) and thioredoxin reductase 1 (TrxR1) remained unchanged. These novel data demonstrate that exercising to exhaustion activates NF-κB signalling in human skeletal muscle and regulates the expression levels of antioxidant enzymes in human skeletal muscle. The fast regulation of NF-κB at exercise cessation has implications for the interpretation of published studies and the design of new experiments.
Phyllanthus emblica: A comprehensive review of its therapeutic benefits
2021, South African Journal of BotanyMedicinal plants are precious gifts of nature, which may serve as a source of food and medicine to humans. Phyllanthus emblica L has held a unique position in the Indian (Ayurvedic), Turkish, Unani, and Tibetan medicinal systems for centuries. Its nutritional, therapeutic and healing potentials have made it a valid research option for the development of novel drug formulations with few side effects. The presence of vitamin C, alkaloids, ellagitannins, gallic acid, emblicanin A and emblicanin B, flavonoids (especially rutin and quercetin), and a variety of biological molecules, makes P. emblica, a valued medicinal plant. This review article summarizes the recent literature relevant to the nutritional, health, and therapeutic benefits of P. emblica, such as potential chemo-preventive, anti-diabetic, anti-microbial, anti-inflammatory, analgesic, anti-mutagenic, antioxidant, diuretic, aphrodisiac, UV protectant, and anti-aging activities. Its applications in memory enhancing, respiratory, skin and ophthalmic disorders, and detoxification including that of snake venom, are also highlighted. It additionally reviews retrospective studies on P. emblica at the molecular level, for disease management and control. P. emblica is an important medicinal plant with many benefits. It has been used for centuries and generations as a source of food because of its unique restorative and rejuvenating potential. Thus, in light of the sum of these investigations, new studies could be designed to explore valuable bioactive compounds present throughout in nature in the form of plants
Bu-Shen-Fang-Chuan formula attenuates cigarette smoke-induced inflammation by modulating the PI3K/Akt-Nrf2 and NF-κB signalling pathways
2020, Journal of EthnopharmacologyChronic obstructive pulmonary disease (COPD) is a respiratory inflammatory disease. Unlike asthma, COPD is insensitive to glucocorticoid treatment; thus, it is of great importance to find alternative medications, including Chinese medicine, to suppress inflammation. Bu-Shen-Fang-Chuan formula (BSFCF) is commonly used for the treatment of COPD in China. However, the mechanisms of BSFCF in COPD treatment are still unclear.
To verify the anti-inflammatory efficacy of BSFCF in COPD and to explore the possible mechanisms underlying its anti-inflammatory efficacy based on the phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt)-Nuclear factor erythroid 2-related factor 2 (Nrf2) and Nuclear factor (NF)-κB signalling pathways.
A rat model of COPD was established by chronic exposure to cigarette smoke (CS) for 6 months. Bronchoalveolar lavage fluid (BALF) and blood were obtained to detect inflammatory cytokines. Lung samples were harvested, and part of each sample was fixed for subsequent H&E staining and immunohistochemical (IHC) analysis. The remaining lung tissues were used for RNA sequencing analysis and western blotting.
BSFCF significantly reduced inflammatory infiltration in the lungs of CS-exposed rats and decreased the concentrations of tumor necrosis factor (TNF)-α and interleukin (IL)-6 in both the BALF and serum. Additionally, BSFCF evidently attenuated NF-κB activation and downregulation of glucocorticoid receptor (GR) caused by CS. Furthermore, BSFCF increased the activation of PI3K/Akt-Nrf2 signalling in response to CS.
BSFCF attenuated CS-induced inflammation in COPD, which was partially achieved through the PI3K/Akt-Nrf2 and NF-κB signalling pathways.
Minocycline reverses IL-17A/TRAF3IP2-mediated p38 MAPK/NF-κB/iNOS/NO-dependent cardiomyocyte contractile depression and death
2020, Cellular SignallingMinocycline, an FDA-approved second-generation semisynthetic tetracycline, exerts antioxidant, anti-apoptotic and anti-inflammatory effects, independent of its antimicrobial properties. Interleukin (IL)-17A is an immune and inflammatory mediator, and its sustained induction is associated with various cardiovascular diseases. Here we investigated (i) whether IL-17A induces cardiomyocyte contractile depression and death, (ii) whether minocycline reverses IL-17A's negative inotropic effects and (iii) investigated the underlying molecular mechanisms. Indeed, treatment with recombinant mouse IL-17A impaired adult cardiomyocyte contractility as evidenced by a 34% inhibition in maximal velocity of shortening and relengthening after 4 h (P < .01). Contractile depression followed iNOS induction at 2 h (2.13-fold, P < .01) and NO generation at 3 h (3.71-fold, P <.01). Further mechanistic investigations revealed that IL-17A-dependent induction of iNOS occurred via TRAF3IP2, TRAF6, TAK1, NF-κB, and p38MAPK signaling. 1400 W, a highly specific iNOS inhibitor, suppressed IL-17A-induced NO generation and contractile depression, where as the NO donors SNAP and PAPA-NONOate both suppressed cardiomyocyte contractility. IL-17A also stimulated cardiomyocyte IL-1β and TNF-α secretion, however, their neutralization failed to modulate IL-17A-mediated contractile depression or viability. Further increases of IL-17A concentration and the duration of exposure enhanced IL-1β and TNF-α secreted levels, buthad no impact on adult cardiomyocyte viability. However, when combined with pathophysiological concentrations of IL-1β or TNF-α, IL-17A promoted adult cardiomyocyte death. Importantly, minocycline blunted IL-17A-mediated deleterious effects, indicating its therapeutic potential in inflammatory cardiac diseases.
Potential role of NF-κB pathway in the immuno-inflammatory responses during human cystic echinococcosis
2020, Acta TropicaCystic echinococcosis (CE) induces in the human host innate and adaptive immune response that plays an important role in controlling the immunopathogenesis. Due to the crucial role of nuclear factor kappa B (NF-κB) in regulating immuno-inflammatory processes, we investigated its potential contribution in systemic and local immuno-inflammatory responses in primary CE patients and relapsed patients. The expression of NF-κB and inducible nitric oxide synthase (iNOS) was analyzed in peripheral blood mononuclear cells (PBMC) as well as in pericystic layer of pulmonary hydatid cysts from Algerian primary CE patients and relapsed patients. Tumor necrosis factor alpha (TNF-α) and nitric oxide (NO) production was evaluated in plasma samples. Our results showed high iNOS and NF-κB expression in both PBMCs and pericystic histiocytes from primary CE patients. In addition, substantial amounts of systemic NO and TNF-α were detected in the same patients. Remarkably, relapsed patients exhibited a low NF-κB and iNOS expression associated with low amounts of plasmatic TNF-α and NO. Collectively, NF-κB/iNOS pathway is involved in the host defense mechanisms at the systemic and local level during primary CE. Our results indicate that the inhibition of this pathway in relapsed patients will attenuate protective immunity and promote parasite escape. This study allowed to identify a novel predictive biomarkers of hydatidosis.
Oxidative stress in the lung – The essential paradox
2018, Current Opinion in ToxicologyAs eukaryotic life evolved, so too did the need for a source of energy that meets the requirements of complex organisms. Oxygen provides this vast potential energy source, but the same chemical reactivity which provides this potential also can have detrimental effects. The lung evolved as an organ that can efficiently promote gas exchange for the entire organism but as such, the lung is highly susceptible to its external environment. Oxygen can be transformed through both enzymatic and non-enzymatic processes into reactive oxygen species (ROS) and reactive nitrogen species (RNS), which can lead to protein, lipid, and DNA damage. Under normal conditions ROS/RNS concentrations are minimized through the activity of antioxidants located both intracellularly and in the epithelial lining fluid of the lung. Oxidative stress in the lung results when the antioxidant capacity is overwhelmed or depleted through external exposures, such as altered oxygen tension or air pollution, or internally. Internal sources of oxidative stress include systemic disease and the activation of resident cells and inflammatory cells recruited in response to an exposure or systemic response. Pulmonary responses to oxidative stress include activation of oxidases, lipid peroxidation, increases in nitric oxide, and autophagy. These internal and external exposures with the subsequent pulmonary responses contribute to development of diseases directly linked to oxidative stress. These include asthma, COPD, and lung cancers. While the vulnerability of the lung to oxidative stress is acknowledged, few effective preventative strategies or therapeutics are currently available.