Activation of the JAK-STAT pathway by reactive oxygen species

1998 ◽  
Vol 275 (6) ◽  
pp. C1640-C1652 ◽  
Author(s):  
Amy R. Simon ◽  
Usha Rai ◽  
Barry L. Fanburg ◽  
Brent H. Cochran

Reactive oxygen species (ROS) play an important role in the pathogenesis of many human diseases, including the acute respiratory distress syndrome, Parkinson’s disease, pulmonary fibrosis, and Alzheimer’s disease. In mammalian cells, several genes known to be induced during the immediate early response to growth factors, including the protooncogenes c- fos and c- myc, have also been shown to be induced by ROS. We show that members of the STAT family of transcription factors, including STAT1 and STAT3, are activated in fibroblasts and A-431 carcinoma cells in response to H2O2. This activation occurs within 5 min, can be inhibited by antioxidants, and does not require protein synthesis. STAT activation in these cell lines is oxidant specific and does not occur in response to superoxide- or nitric oxide-generating stimuli. Buthionine sulfoximine, which depletes intracellular glutathione, also activates the STAT pathway. Moreover, H2O2stimulates the activity of the known STAT kinases JAK2 and TYK2. Activation of STATs by platelet-derived growth factor (PDGF) is significantly inhibited by N-acetyl-l-cysteine and diphenylene iodonium, indicating that ROS production contributes to STAT activation in response to PDGF. These findings indicate that the JAK-STAT pathway responds to intracellular ROS and that PDGF uses ROS as a second messenger to regulate STAT activation.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Feng Gao ◽  
Tianyi Shao ◽  
Yunpeng Yu ◽  
Yujie Xiong ◽  
Lihua Yang

AbstractActing by producing reactive oxygen species (ROS) in situ, nanozymes are promising as antimicrobials. ROS’ intrinsic inability to distinguish bacteria from mammalian cells, however, deprives nanozymes of the selectivity necessary for an ideal antimicrobial. Here we report that nanozymes that generate surface-bound ROS selectively kill bacteria over mammalian cells. This result is robust across three distinct nanozymes that universally generate surface-bound ROS, with an oxidase-like silver-palladium bimetallic alloy nanocage, AgPd0.38, being the lead model. The selectivity is attributable to both the surface-bound nature of ROS these nanozymes generate and an unexpected antidote role of endocytosis. Though surface-bound, the ROS on AgPd0.38 efficiently eliminated antibiotic-resistant bacteria and effectively delayed the onset of bacterial resistance emergence. When used as coating additives, AgPd0.38 enabled an inert substrate to inhibit biofilm formation and suppress infection-related immune responses in mouse models. This work opens an avenue toward biocompatible nanozymes and may have implication in our fight against antimicrobial resistance.


2021 ◽  
Vol 43 (1) ◽  
Author(s):  
Takahito Moriwaki ◽  
Akari Yoshimura ◽  
Yuki Tamari ◽  
Hiroyuki Sasanuma ◽  
Shunichi Takeda ◽  
...  

Abstract Background Peroxiredoxin 1 (PRDX1) is a member of a ubiquitous family of thiol peroxidases that catalyze the reduction of peroxides, including hydrogen peroxide. It functions as an antioxidant enzyme, similar to catalase and glutathione peroxidase. PRDX1 was recently shown act as a sensor of reactive oxygen species (ROS) and play a role in ROS-dependent intracellular signaling pathways. To investigate its physiological functions, PRDX1 was conditionally disrupted in chicken DT40 cells in the present study. Results The depletion of PRDX1 resulted in cell death with increased levels of intracellular ROS. PRDX1-depleted cells did not show the accumulation of chromosomal breaks or sister chromatid exchange (SCE). These results suggest that cell death in PRDX1-depleted cells was not due to DNA damage. 2-Mercaptoethanol protected against cell death in PRDX1-depleted cells and also suppressed elevations in ROS. Conclusions PRDX1 is essential in chicken DT40 cells and plays an important role in maintaining intracellular ROS homeostasis (or in the fine-tuning of cellular ROS levels). Cells deficient in PRDX1 may be used as an endogenously deregulated ROS model to elucidate the physiological roles of ROS in maintaining proper cell growth.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 782.2-782
Author(s):  
C. H. Lee ◽  
C. H. Chung ◽  
Y. J. Choi ◽  
W. H. Yoo ◽  
J. Y. Kim ◽  
...  

Background:Reactive oxygen species (ROS) are one of the significant factors of chemical or physical cell signaling in a wide variety of cell types including skeletal cells. Receptor activator of NF-βB ligand (RANKL) induces generation of intracellular ROS, which act as second messengers in RANKL-mediated osteoclastogenesis. Dual oxidase maturation factor 1 (Duoxa1) was first identified as aDrosophilaNumb-interacting protein (NIP), and has been associated with the maturation of ROS generating enzymes including dual oxidases (Duox1 and Duox2). In the progression of osteoclast differentiation using mouse bone marrow-derived macrophages (BMMs), we identified that only Duoxa1 level showed an effective change upon RANKL stimulation, but not Duox1, Duox2, and Duoxa2.Objectives:we hypothesized that Duoxa1 could independently act as a second messenger for RANKL stimulation and regulate ROS production during osteoclast differentiation.Methods:Using siRNA or retrovirus transduction and knockdown of Duoxa1 via siRNAResults:Duoxa1 level gradually increased during RANKL-induced osteoclast differentiation. We found that Duoxa1 regulated RANKL-stimulated osteoclast formation and bone resorption positively. knockdown of Duoxa1 via siRNA decreased the RANKL-induced ROS production. During Duoxa1-related control of osteoclastogenesis, activation of tumor necrosis factor receptor (TNFR)-associated factor 6 (TRAF6)-mediated early signaling molecules including MAPKs, Akt, IβB, Btk, and PLC 2 was affected, which sequentially modified the mRNA or protein expression levels of key transcription factors in osteoclastogenesis, such as c-Fos and NFATc1, as well as mRNA expression of osteoclast-specific markers including OSCAR, ATP6v0d2, and CtsK.Conclusion:Overall, our data indicate that Duoxa1 plays a crucial role in osteoclastogenesis via regulating RANKL-induced intracellular ROS production and activating TRAF6-mediated signaling.Disclosure of Interests:None declared


2011 ◽  
Vol 45 (4) ◽  
pp. 1638-1644 ◽  
Author(s):  
Guoping Zhao ◽  
Jun Wang ◽  
Xiaofei Wang ◽  
Shaopeng Chen ◽  
Ye Zhao ◽  
...  

2005 ◽  
Vol 289 (1) ◽  
pp. C207-C216 ◽  
Author(s):  
Li Zuo ◽  
Thomas L. Clanton

Many tissues produce reactive oxygen species (ROS) during reoxygenation after hypoxia or ischemia; however, whether ROS are formed during hypoxia is controversial. We tested the hypothesis that ROS are generated in skeletal muscle during exposure to acute hypoxia before reoxygenation. Isolated rat diaphragm strips were loaded with dihydrofluorescein-DA (Hfluor-DA), a probe that is oxidized to fluorescein (Fluor) by intracellular ROS. Changes in fluorescence due to Fluor, NADH, and FAD were measured using a tissue fluorometer. The system had a detection limit of 1 μM H2O2 applied to the muscle superfusate. When the superfusion buffer was changed rapidly from 95% O2 to 0%, 5%, 21%, or 40% O2, transient elevations in Fluor were observed that were proportional to the rise in NADH fluorescence and inversely proportional to the level of O2 exposure. This signal could be inhibited completely with 40 μM ebselen, a glutathione peroxidase mimic. After brief hypoxia exposure (10 min) or exposure to brief periods of H2O2, the fluorescence signal returned to baseline. Furthermore, tissues loaded with the oxidized form of the probe (Fluor-DA) showed a similar pattern of response that could be inhibited with ebselen. These results suggest that Fluor exists in a partially reversible redox state within the tissue. When Hfluor-loaded tissues were contracted with low-frequency twitches, Fluor emission and NADH emission were significantly elevated in a way that resembled the hypoxia-induced signal. We conclude that in the transition to low intracellular Po2, a burst of intracellular ROS is formed that may have functional implications regarding skeletal muscle O2-sensing systems and responses to acute metabolic stress.


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