Reactive oxygen species modulate HIF-1 mediated PAI-1 expression: involvement of the GTPase Rac1

2003 ◽  
Vol 89 (05) ◽  
pp. 926-935 ◽  
Author(s):  
Utta Berchner-Pfannschmidt ◽  
Christoph Wotzlaw ◽  
Robbert Cool ◽  
Joachim Fandrey ◽  
Helmut Acker ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Plasminogen Activator Inhibitor ◽  
Dominant Negative ◽  
Mrna Levels ◽  
Ros Production ◽  
Oxygen Species ◽  
Plasminogen Activator Inhibitor 1 ◽  
Pai 1

SummaryThe hypoxia-inducible transcription factor HIF-1 mediates upregulation of plasminogen activator inhibitor-1 (PAI-1) expression under hypoxia. Reactive oxygen species (ROS) have also been implicated in PAI-1 gene expression. However, the role of ROS in HIF-1-mediated regulation of PAI-1 is not clear. We therefore investigated the role of the GTPase Rac1 which modulates ROS production in the pathway leading to HIF-1 and PAI-1 induction.Overexpression of constitutively activated (RacG12V) or dominant-negative (RacT17N) Rac1 increased or decreased, respectively, ROS production. In RacG12V-expressing cells, PAI-1 mRNA levels as well as HIF-1α nuclear presence were reduced under normoxia and hypoxia whereas expression of RacT17N resulted in opposite effects. Treatment with the antioxidant pyrrolidinedithiocarbamate or coexpression of the redox factor-1 restored HIF-1 and PAI-1 promoter activity in RacG12V-cells. In contrast, NFκB activation was enhanced in RacG12V-cells, but abolished by RacT17N. Thus, these findings suggest a mechanism explaining modified fibrinolysis and tissue remodeling in an oxidized environment.

scholarly journals Graphene and graphene oxide induce ROS production in human HaCaT skin keratinocytes: the role of xanthine oxidase and NADH dehydrogenase

Nanoscale ◽  
2018 ◽  
Vol 10 (25) ◽  
pp. 11820-11830 ◽  
Author(s):  
Marco Pelin ◽  
Laura Fusco ◽  
Cristina Martín ◽  
Silvio Sosa ◽  
Javier Frontiñán-Rubio ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Graphene Oxide ◽  
Xanthine Oxidase ◽  
Nadh Dehydrogenase ◽  
Reactive Oxygen ◽  
Ros Production ◽  
Oxygen Species ◽  
Mitochondrial Depolarization ◽  
Skin Keratinocytes

Graphene based nanomaterials induce a reactive oxygen species-mediated mitochondrial depolarization, caused by the activation of NADH dehydrogenase and xanthine oxidase.

scholarly journals SPARC Levels Modulate the Capacity of Mitomycin to Inhibit the Proliferation of Human Tenon’s Capsule Fibroblasts

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Yuanyuan Guo ◽  
Shouxiang Ni ◽  
Weiyan Zhou ◽  
Jiangping Hou ◽  
Jiaquan Shen
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Density ◽  
Collagen Gel ◽  
Reactive Oxygen ◽  
Control Group ◽  
Mrna Levels ◽  
Oxygen Species ◽  
Antifibrotic Effect ◽  
Cell Densities

Purpose. To evaluate the role of SPARC in the antiproliferation effect of MMC on human Tenon’s fibroblasts (HTF). Method. Sixteen PACG patients aged 59 ± 10 years (31–72 years), including 6 males and 10 females, were recruited. Tenon tissue was harvested during filtering surgery. Cell density was evaluated after MMC application with different concentrations and application times, by which the optimized MMC application modality was determined. MMC, si-SPARC, or SPARC protein was used when needed to evaluate the cell densities under different conditions, by which the role of SPARC in MMC-mediated antifibrotic process was identified. Results. Considering that the cell densities, as well as SPARC expression on mRNA and protein levels, are relatively stable when the MMC concentration is higher than 0.02% and exposure time longer than 90 s, we chose the MMC application pattern with 0.02% and 90 s as an optimized pattern for the downstream work. Compared to control, the si-SPARC and MMC downregulated the SPARC protein by 91% (P<0.01) and 65% (P<0.01) and mRNA by 96% (P<0.01) and 64% (P<0.01), respectively. MMC decreases the cell densities by 53.50% compared to control. si-SPARC + MMC dramatically deceased the cell density no matter compared to the control group (P<0.01) or MMC group (P<0.01); correspondingly, the relative collagen gel area in the MMC + si-SPARC group was higher than that in the MMC group or si-SPARC group (P<0.05). The reactive oxygen species expression in the MMC + si-SPARC group is higher than that in the MMC group (P<0.05). Conclusion. This study demonstrates that in HTF, (1) MMC downregulates the expression of SPARC in protein and mRNA levels; (2) SPARC depletion has synergistic effect on the antifibrotic effect of MMC; and (3) reactive oxygen species are the possible mediator in the antifibrotic effect of MMC and si-SPARC.

scholarly journals Production, Signaling, and Scavenging Mechanisms of Reactive Oxygen Species in Fruit–Pathogen Interactions

2019 ◽  
Vol 20 (12) ◽  
pp. 2994 ◽  
Author(s):  
Ying Wang ◽  
Dongchao Ji ◽  
Tong Chen ◽  
Boqiang Li ◽  
Zhanquan Zhang ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Pathogenic Fungi ◽  
Ros Production ◽  
Oxygen Species ◽  
Ros Homeostasis ◽  
Molecular Damage ◽  
Different Levels ◽  
In Cells

Reactive oxygen species (ROS) play a dual role in fruit–pathogen interaction, which largely depends on their different levels in cells. Fruit recognition of a pathogen immediately triggers an oxidative burst that is considered an integral part of the fruit defense response. ROS are also necessary for the virulence of pathogenic fungi. However, the accumulation of ROS in cells causes molecular damage and finally leads to cell death. In this review, on the basis of data regarding ROS production and the scavenging systems determining ROS homeostasis, we focus on the role of ROS in fruit defense reactions against pathogens and in fungi pathogenicity during fruit–pathogen interaction.

scholarly journals RNAi-Mediated Down-Regulation of Dicer-Like 2 and 4 Changes the Response of ‘Moneymaker’ Tomato to Potato Spindle Tuber Viroid Infection from Tolerance to Lethal Systemic Necrosis, Accompanied by Up-Regulation of miR398, 398a-3p and Production of Excessive Amount of Reactive Oxygen Species

Viruses ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 344 ◽  
Author(s):  
Takahiro Suzuki ◽  
Sho Ikeda ◽  
Atsushi Kasai ◽  
Akito Taneda ◽  
Misato Fujibayashi ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Potato Spindle Tuber Viroid ◽  
Ros Production ◽  
Oxygen Species ◽  
Superoxide Dismutase 1 ◽  
Systemic Necrosis ◽  
Viroid Infection ◽  
Infected Line

To examine the role of RNA silencing in plant defenses against viroids, a Dicer-like 2 and 4 (DCL2&4)–double knockdown transgenic tomato plant line, 72E, was created. The expression of endogenous SlDCL2s and SlDCL4 in line 72E decreased to about a half that of the empty cassette line, EC. When challenged with potato spindle tuber viroid (PSTVd), line 72E showed significantly higher levels of PSTVd accumulation early in the course of the infection and lethal systemic necrosis late in the infection. The size distribution of PSTVd-derived small RNAs was significantly different with the number of RNAs of 21 and 22 nucleotides (nt) in line 72E, at approximately 66.7% and 5% of those in line EC, respectively. Conversely, the numbers of 24 nt species increased by 1100%. Furthermore, expression of the stress-responsive microRNA species miR398 and miR398a-3p increased 770% and 868% in the PSTVd-infected line 72E compared with the PSTVd-infected EC. At the same time, the expression of cytosolic and chloroplast-localized Cu/Zn-superoxide dismutase 1 and 2 (SOD1 and SOD2) and the copper chaperon for SOD (CCS1) mRNAs, potential targets of miR398 or 398a-3p, decreased significantly in the PSTVd-infected line 72E leaves, showing necrosis. In concert with miR398 and 398a-3p, SODs control the detoxification of reactive oxygen species (ROS) generated in cells. Since high levels of ROS production were observed in PSTVd-infected line 72E plants, it is likely that the lack of full dicer-likes (DCL) activity in these plants made them unable to control excessive ROS production after PSTVd infection, as disruption in the ability of miR398 and miR398a-3p to regulate SODs resulted in the development of lethal systemic necrosis.

scholarly journals Reactive Oxygen Species: A Promising Therapeutic Target for SDHx-Mutated Pheochromocytoma and Paraganglioma

Cancers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 3769
Author(s):  
Katerina Hadrava Hadrava Vanova ◽  
Chunzhang Yang ◽  
Leah Meuter ◽  
Jiri Neuzil ◽  
Karel Pacak
Keyword(s):  
Reactive Oxygen Species ◽  
Tumor Cells ◽  
Reactive Oxygen ◽  
Ros Production ◽  
Oxygen Species ◽  
Ros Scavenging ◽  
Promising Therapeutic Target ◽  
Ros Accumulation ◽  
Intracellular Ros

Pheochromocytoma (PHEO) and paraganglioma (PGL) are rare neuroendocrine tumors derived from neural crest cells. Germline variants in approximately 20 PHEO/PGL susceptibility genes are found in about 40% of patients, half of which are found in the genes that encode succinate dehydrogenase (SDH). Patients with SDH subunit B (SDHB)-mutated PHEO/PGL exhibit a higher likelihood of developing metastatic disease, which can be partially explained by the metabolic cell reprogramming and redox imbalance caused by the mutation. Reactive oxygen species (ROS) are highly reactive molecules involved in a multitude of important signaling pathways. A moderate level of ROS production can help regulate cellular physiology; however, an excessive level of oxidative stress can lead to tumorigenic processes including stimulation of growth factor-dependent pathways and the induction of genetic instability. Tumor cells effectively exploit antioxidant enzymes in order to protect themselves against harmful intracellular ROS accumulation, which highlights the essential balance between ROS production and scavenging. Exploiting ROS accumulation can be used as a possible therapeutic strategy in ROS-scavenging tumor cells. Here, we focus on the role of ROS production in PHEO and PGL, predominantly in SDHB-mutated cases. We discuss potential strategies and approaches to anticancer therapies by enhancing ROS production in these difficult-to-treat tumors.

A crucial role for reactive oxygen species in RANKL-induced osteoclast differentiation

Blood ◽  
2005 ◽  
Vol 106 (3) ◽  
pp. 852-859 ◽  
Author(s):  
Na Kyung Lee ◽  
Young Geum Choi ◽  
Ji Youn Baik ◽  
Song Yi Han ◽  
Dae-won Jeong ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Osteoclast Differentiation ◽  
Tumor Necrosis Factor Receptor ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Reactive Oxygen ◽  
Dominant Negative ◽  
Dominant Negative Mutant ◽  
Ros Production ◽  
Oxygen Species ◽  
Diphenylene Iodonium

Abstract Signaling by receptor activator of NF-κB (nuclear factor-κB) ligand (RANKL) is essential for differentiation of bone marrow monocyte-macrophage lineage (BMM) cells into osteoclasts. Here, we show RANKL stimulation of BMM cells transiently increased the intracellular level of reactive oxygen species (ROS) through a signaling cascade involving TNF (tumor necrosis factor) receptor-associated factor (TRAF) 6, Rac1, and NADPH (nicotinamide adenine dinucleotide phosphate) oxidase (Nox) 1. A deficiency in TRAF6 or expression of a dominant-interfering mutant of TRAF6 blocks RANKL-mediated ROS production. Application of N-acetylcysteine (NAC) or blocking the activity of Nox, a protein leading to the formation of ROS, with diphenylene iodonium (DPI) inhibits the responses of BMM cells to RANKL, including ROS production, activation of c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein (MAP) kinase, and extracellular signal-regulated kinase (ERK), and osteoclast differentiation. Moreover, both RANKL-mediated ROS production and osteoclast differentiation were completely blocked in precursors depleted of Nox1 activity by RNA interference or by expressing a dominant-negative mutant of Rac1. Together, these results indicate that ROSs act as an intracellular signal mediator for osteoclast differentiation.

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