Decidualized Human Endometrial Stromal Cells Mediate Hemostasis, Angiogenesis, and Abnormal Uterine Bleeding

PubMed Central

Lockwood, Charles J.; Krikun, Graciela; Hickey, Martha; Huang, S. Joseph; Schatz, Frederick

2011-01-01

Factor VII binds trans-membrane tissue factor to initiate hemostasis by forming thrombin. Tissue factor expression is enhanced in decidualized human endometrial stromal cells during the luteal phase. Long-term progestin only contraceptives elicit: 1) abnormal uterine bleeding from fragile vessels at focal bleeding sites, 2) paradoxically high tissue factor expression at bleeding sites; 3) reduced endometrial blood flow promoting local hypoxia and enhancing reactive oxygen species levels; and 4) aberrant angiogenesis reflecting increased stromal cell-expressed vascular endothelial growth factor, decreased Angiopoietin-1 and increased endothelial cell-expressed Angiopoietin-2. Aberrantly high local vascular permeability enhances circulating factor VII to decidualized stromal cell-expressed tissue factor to generate excess thrombin. Hypoxia-thrombin interactions augment expression of vascular endothelial growth factor and interleukin-8 by stromal cells. Thrombin, vascular endothelial growth factor and interlerukin-8 synergis-tically augment angiogenesis in a milieu of reactive oxygen species-induced endothelial cell activation. The resulting enhanced vessel fragility promotes abnormal uterine bleeding. PMID:19208784

Lipophilic Compound-Mediated Gene Expression and Implication for Intervention in Reactive Oxygen Species (ROS)-Related Diseases: Mini-review

PubMed Central

Nakamura, Yukiko K.; Omaye, Stanley T.

2010-01-01

In addition to exhibiting antioxidant properties, conjugated linoleic acid (CLA) and vitamin E may modulate gene expression of endogenous antioxidant enzymes. Depending on cellular microenvironments, such modulation reflects either antioxidant or prooxidant outcomes. Although epidemiological/experimental studies have indicated that CLA and vitamin E have health promoting properties, recent findings from clinical trials have been inconclusive. Discrepancies between the results found from prospective studies and recent clinical trials might be attributed to concentration-dependent cellular microenvironment alterations. We give a perspective of possible molecular mechanisms of actions of these lipophilic compounds and their implications for interventions of reactive oxygen species (ROS)-related diseases. PMID:22254050

Oxygen delivery, consumption, and conversion to reactive oxygen species in experimental models of diabetic retinopathy

PubMed Central

Eshaq, Randa S.; Wright, William S.; Harris, Norman R.

2014-01-01

Retinal tissue receives its supply of oxygen from two sources – the retinal and choroidal circulations. Decreases in retinal blood flow occur in the early stages of diabetes, with the eventual development of hypoxia thought to contribute to pathological neovascularization. Oxygen consumption in the retina has been found to decrease in diabetes, possibly due to either a reduction in neuronal metabolism or to cell death. Diabetes also enhances the rate of conversion of oxygen to superoxide in the retina, with experimental evidence suggesting that mitochondrial superoxide not only drives the overall production of reactive oxygen species, but also initiates several pathways leading to retinopathy, including the increased activity of the polyol and hexosamine pathways, increased production of advanced glycation end products and expression of their receptors, and activation of protein kinase C. PMID:24936440

Oxygen delivery, consumption, and conversion to reactive oxygen species in experimental models of diabetic retinopathy.

PubMed

Eshaq, Randa S; Wright, William S; Harris, Norman R

2014-01-01

Retinal tissue receives its supply of oxygen from two sources - the retinal and choroidal circulations. Decreases in retinal blood flow occur in the early stages of diabetes, with the eventual development of hypoxia thought to contribute to pathological neovascularization. Oxygen consumption in the retina has been found to decrease in diabetes, possibly due to either a reduction in neuronal metabolism or to cell death. Diabetes also enhances the rate of conversion of oxygen to superoxide in the retina, with experimental evidence suggesting that mitochondrial superoxide not only drives the overall production of reactive oxygen species, but also initiates several pathways leading to retinopathy, including the increased activity of the polyol and hexosamine pathways, increased production of advanced glycation end products and expression of their receptors, and activation of protein kinase C.

Autoamplificatory singlet oxygen generation sensitizes tumor cells for intercellular apoptosis-inducing signaling.

PubMed

Bauer, Georg

2018-06-01

Tumor cells express NADPH oxidase-1 (NOX1) in their membrane and control NOX1-based intercellular reactive oxygen and nitrogen species (ROS/RNS)-dependent apoptosis-inducing signaling through membrane-associated catalase and superoxide dismutase. of tumor cells with high concentrations of H 2 O 2 , peroxnitrite, HOCl, or increasing the concentration of cell-derived NO causes initial generation of singlet oxygen and local inactivation of membrane-associated catalase. As a result, free peroxynitrite and H 2 O 2 interact and generate secondary singlet oxygen. Inactivation of further catalase molecules by secondary singlet oxygen leads to auto-amplification of singlet oxygen generation and catalase inactivation. This allows reactivation of intercellular ROS/RNS-signaling and selective apoptosis induction in tumor cells. The initial singlet oxygen generation seems to be the critical point in this complex biochemical multistep mechanism. Initial singlet oxygen generation requires the interaction between distinct tumor cell-derived ROS and RNS and may also depend on either the induction of NO synthase expression or NOX1 activation through the FAS receptor. FAS receptor activation can be achieved by singlet oxygen. Autoamplificatory generation of singlet oxygen through the interaction between peroxynitrite and hydrogen peroxide inherits a rich potential for the establishment of synergistic effects that may be instrumental for novel approaches of tumor therapy with high selectivity towards malignant cells. Copyright © 2017 Elsevier B.V. All rights reserved.

12-Chloracetyl-PPD, a novel dammarane derivative, shows anti-cancer activity via delay the progression of cell cycle G2/M phase and reactive oxygen species-mediate cell apoptosis.

PubMed

Wang, Xu De; Sun, Yuan Yuan; Zhao, Chen; Qu, Fan Zhi; Zhao, Yu Qing

2017-03-05

(20R)-Dammarane-3β, 12β, 20, 25-tetrol (25-OH-PPD) is a ginsenoside isolated from Panax ginseng (C. A. Meyer). This compound exhibits anti-cancer activities on many human cancer cell lines. In this study, we investigated anti-cancer mechanisms of 12β-O-( L -Chloracetyl)-dammar-20(22)-ene-3β,25-diol(12-Chloracetyl-PPD), a modified 25-OH-PPD. We found that compound 12-Chloracetyl-PPD resulted in a concentration-dependent inhibition of viability in prostate, breast, and gastric cancer cells, without affecting the viability of normal cell (human gastric epithelial cell line-GES-1, hair follicle dermal papilla cell line-HHDPC and rat myocardial cell line-H9C2). In MDA-MB-435 and C4-2B cancer cells, 12-Chloracetyl-PPD induced G2/M cell cycle arrest, down-regulated mouse double minute 2 (MDM2) expression, up-regulated p53 expression, triggered apoptosis, and stimulated reactive oxygen species production. Apoptosis can be attenuated by the reactive oxygen species scavenger N-acetylcysteine. Our results suggested that compound 12-Chloracetyl-PPD showed obvious anti-cancer activity based on delaying cell cycle arrest and inducing cell apoptosis by reactive oxygen species production, which supported development of 12-Chloracetyl-PPD as a potential agent for cancer chemotherapy. Copyright © 2017 Elsevier B.V. All rights reserved.

γ-Oryzanol suppresses COX-2 expression by inhibiting reactive oxygen species-mediated Erk1/2 and Egr-1 signaling in LPS-stimulated RAW264.7 macrophages.

PubMed

Shin, Soon Young; Kim, Heon-Woong; Jang, Hwan-Hee; Hwang, Yu-Jin; Choe, Jeong-Sook; Kim, Jung-Bong; Lim, Yoongho; Lee, Young Han

2017-09-16

Cyclooxygenase (COX)-2 produces prostanoids, which contribute to inflammatory responses. Nuclear factor (NF)-κB is a key transcription factor mediating COX-2 expression. γ-Oryzanol is an active component in rice bran oil, which inhibits lipopolysaccharide (LPS)-mediated COX-2 expression by inhibiting NF-κB. However, the inhibition of COX-2 expression by γ-oryzanol independently of NF-κB is poorly understood. We found that LPS upregulated Egr-1 expression at the transcriptional level. Forced expression of Egr-1 trans-activated the Cox-2 promoter independently of NF-κB. In contrast, silencing of Egr-1 abrogated LPS-mediated COX-2 expression. LPS produced reactive oxygen species (ROS), which, in turn, induced Egr-1 expression via the Erk1/2 MAPK pathway. ROS scavenging activity of γ-oryzanol suppressed Egr-1 expression by inhibiting the Erk1/2 MAPK pathway. Our results suggest that γ-oryzanol inhibits LPS-mediated COX-2 expression by suppressing Erk1/2-mediated Egr-1 expression. This study supports that γ-oryzanol may be useful for ameliorating LPS-mediated inflammatory responses. Copyright © 2017 Elsevier Inc. All rights reserved.

Hydroxychavicol, a Piper betle leaf component, induces apoptosis of CML cells through mitochondrial reactive oxygen species-dependent JNK and endothelial nitric oxide synthase activation and overrides imatinib resistance.

PubMed

Chakraborty, Jayashree B; Mahato, Sanjit K; Joshi, Kalpana; Shinde, Vaibhav; Rakshit, Srabanti; Biswas, Nabendu; Choudhury Mukherjee, Indrani; Mandal, Labanya; Ganguly, Dipyaman; Chowdhury, Avik A; Chaudhuri, Jaydeep; Paul, Kausik; Pal, Bikas C; Vinayagam, Jayaraman; Pal, Churala; Manna, Anirban; Jaisankar, Parasuraman; Chaudhuri, Utpal; Konar, Aditya; Roy, Siddhartha; Bandyopadhyay, Santu

2012-01-01

Alcoholic extract of Piper betle (Piper betle L.) leaves was recently found to induce apoptosis of CML cells expressing wild type and mutated Bcr-Abl with imatinib resistance phenotype. Hydroxy-chavicol (HCH), a constituent of the alcoholic extract of Piper betle leaves, was evaluated for anti-CML activity. Here, we report that HCH and its analogues induce killing of primary cells in CML patients and leukemic cell lines expressing wild type and mutated Bcr-Abl, including the T315I mutation, with minimal toxicity to normal human peripheral blood mononuclear cells. HCH causes early but transient increase of mitochondria-derived reactive oxygen species. Reactive oxygen species-dependent persistent activation of JNK leads to an increase in endothelial nitric oxide synthase-mediated nitric oxide generation. This causes loss of mitochondrial membrane potential, release of cytochrome c from mitochondria, cleavage of caspase 9, 3 and poly-adenosine diphosphate-ribose polymerase leading to apoptosis. One HCH analogue was also effective in vivo in SCID mice against grafts expressing the T315I mutation, although to a lesser extent than grafts expressing wild type Bcr-Abl, without showing significant bodyweight loss. Our data describe the role of JNK-dependent endothelial nitric oxide synthase-mediated nitric oxide for anti-CML activity of HCH and this molecule merits further testing in pre-clinical and clinical settings. © 2011 Japanese Cancer Association.

Antioxidant Activity and Induction of mRNA Expressions of Antioxidant Enzymes in HEK-293 Cells of Moringa oleifera Leaf Extract.

PubMed

Vongsak, Boonyadist; Mangmool, Supachoke; Gritsanapan, Wandee

2015-08-01

The leaves of Moringa oleifera, collected in different provinces in Thailand, were determined for the contents of total phenolics, total flavonoids, major components, and antioxidant activity. The extract and its major active components were investigated for the inhibition of H2O2-induced reactive oxygen species production and the effects on antioxidant enzymes mRNA expression. The extract, crypto-chlorogenic acid, isoquercetin and astragalin, significantly reduced the reactive oxygen species production inducing by H2O2 in HEK-293 cells. Treatment with isoquercetin significantly increased the mRNA expression levels of antioxidant enzymes such as superoxide dismutase, catalase and heme oxygenase 1. These results confirm that M. oleifera leaves are good sources of natural antioxidant with isoquercetin as an active compound. Georg Thieme Verlag KG Stuttgart · New York.

Excess Iodide Induces an Acute Inhibition of the Sodium/Iodide Symporter in Thyroid Male Rat Cells by Increasing Reactive Oxygen Species

PubMed Central

Arriagada, Alejandro A.; Albornoz, Eduardo; Opazo, Ma. Cecilia; Becerra, Alvaro; Vidal, Gonzalo; Fardella, Carlos; Michea, Luis; Carrasco, Nancy; Simon, Felipe; Elorza, Alvaro A.; Bueno, Susan M.; Kalergis, Alexis M.

2015-01-01

Na+/I− symporter (NIS) mediates iodide (I−) uptake in the thyroid gland, the first and rate-limiting step in the biosynthesis of the thyroid hormones. The expression and function of NIS in thyroid cells is mainly regulated by TSH and by the intracellular concentration of I−. High doses of I− for 1 or 2 days inhibit the synthesis of thyroid hormones, a process known as the Wolff-Chaikoff effect. The cellular mechanisms responsible for this physiological response are mediated in part by the inhibition of I− uptake through a reduction of NIS expression. Here we show that inhibition of I− uptake occurs as early as 2 hours or 5 hours after exposure to excess I− in FRTL-5 cells and the rat thyroid gland, respectively. Inhibition of I− uptake was not due to reduced NIS expression or altered localization in thyroid cells. We observed that incubation of FRTL-5 cells with excess I− for 2 hours increased H2O2 generation. Furthermore, the inhibitory effect of excess I− on NIS-mediated I− transport could be recapitulated by H2O2 and reverted by reactive derived oxygen species scavengers. The data shown here support the notion that excess I− inhibits NIS at the cell surface at early times by means of a posttranslational mechanism that involves reactive derived oxygen species. PMID:25594695

[Effects of elevated ozone concentrations on reactive oxygen metabolism and related gene expression in Ginkgo biloba leaves].

PubMed

Ruan, Ya Nan; Xu, Sheng; Guo, Long; Zhu, Ming Zhu; Wang, Cong; Li, Shu Yuan; Wang, Hong Yan

2017-11-01

By using the open top chambers (OTCs) fumigation method, this paper investigated the changes of foliar injury, level of reactive oxygen species (ROS), activities and gene expression of antioxidant enzymes in Ginkgo biloba leaves under different ozone (ambient ozone≈40, 80, 160, 200 nmol·mol -1 ) concentrations, in order to study the effects of elevated ozone (O 3 ) concentrations on reactive metabolism. The results showed that the obvious foliar injuries were observed in 160 and 200 nmol·mol -1 O 3 treatments, while no visible injury was observed in 80 nmol·mol -1 O 3 and ambient O 3 treatments. After 20 d, a significant increase in O 2 -· generation rate was observed in G. biloba leaves exposed to 160, 200 nmol·mol -1 O 3 , compared with ambient ozone and 80 nmol·mol -1 O 3 , and there were no significant differences between ambient O 3 and 80 nmol·mol -1 treatments. After 40 d, H 2 O 2 content of G. biloba leaves in 160 and 200 nmol·mol -1 O 3 was significantly higher than that in 80 nmol·mol -1 and ambient ozone, respectively. The activities of catalase (CAT) in 160 and 200 nmol·mol -1 treatments were also significantly higher than that in 80 nmol·mol -1 and ambient O 3 treatments. The ascorbate peroxidase (APX) activity of leaves for each elevated O 3 treatment was lower than that of ambient ozone. The level of CAT and APX expression increased progressively after 40 d O 3 treatment. The expression intensity of GbD was conspicuously strengthened along with the increase of ozone concentration and fumigation time. Le-vel of reactive oxygen increased, activities of antioxidant enzyme decreased, level of gene expression down-regulated, and foliar visible injury was observed in leaves of G. biloba in elevated ozone stress.

Fullerene (C60) nanoparticles exert photocytotoxicity through modulation of reactive oxygen species and p38 mitogen-activated protein kinase activation in the MCF-7 cancer cell line

NASA Astrophysics Data System (ADS)

Li, Zhi; Zhang, Fei-long; Wang, Zhiyuan; Pan, Li-li; Shen, Ying-ying; Zhang, Zhen-zhong

2013-12-01

The photocytotoxicity of water-dispersed 100-300 nm fullerene amino acid derivatives nanoparticles was studied. The nanoparticle solution of fullerene derivatives, l-phenylalanine (C60-phe) and glycine (C60-gly), suppressed the in vitro growth of MCF-7 cells lines, induced cancer cells apoptosis, and caused a perturbation of the cell cycle. These nanoparticle solutions increased intracellular reactive oxygen species after irradiation. C60-phe or C60-gly upregulated the expression of phosphorylated (p)p38 mitogen-activated protein kinase (MAPK). N-Acetyl- l-cysteine significantly depressed the composite-induced activation of p38MAPK, and the kinase inhibitor SB203580 significantly prevented C60 derivative-induced cell apoptosis. This study revealed that p38MAPK is activated by C60 nanoparticles through triggering reactive oxygen species generation, leading to cancer cell injuries.

Novel roles of folic acid as redox regulator: Modulation of reactive oxygen species sinker protein expression and maintenance of mitochondrial redox homeostasis on hepatocellular carcinoma.

PubMed

Lai, Kun-Goung; Chen, Chi-Fen; Ho, Chun-Te; Liu, Jun-Jen; Liu, Tsan-Zon; Chern, Chi-Liang

2017-06-01

We provide herein several lines of evidence to substantiate that folic acid (or folate) is a micronutrient capable of functioning as a novel redox regulator on hepatocellular carcinoma. First, we uncovered that folate deficiency could profoundly downregulate two prominent anti-apoptotic effectors including survivin and glucose-regulated protein-78. Silencing of either survivin or glucose-regulated protein-78 via small interfering RNA interfering technique established that both effectors could serve as reactive oxygen species sinker proteins. Second, folate deficiency-triggered oxidative-nitrosative stress could strongly induce endoplasmic reticulum stress that in turn could provoke cellular glutathione depletion through the modulation of the following two crucial events: (1) folate deficiency could strongly inhibit Bcl-2 expression leading to severe suppression of the mitochondrial glutathione pool and (2) folate deficiency could also profoundly inhibit two key enzymes that governing cellular glutathione redox regulation including γ-glutamylcysteinyl synthetase heavy chain, a catalytic enzyme for glutathione biosynthesis, and mitochondrial isocitrate dehydrogenase 2, an enzyme responsible for providing nicotinamide adenine dinucleotide phosphate necessary for regenerating oxidized glutathione disulfide back to glutathione via mitochondrial glutathione reductase. Collectively, we add to the literature new data to strengthen the notion that folate is an essential micronutrient that confers a novel role to combat reactive oxygen species insults and thus serves as a redox regulator via upregulating reactive oxygen species sinker proteins and averting mitochondrial glutathione depletion through proper maintenance of redox homeostasis via positively regulating glutathione biosynthesis, glutathione transporting system, and mitochondrial glutathione recycling process.

Prolonged exposure of resveratrol induces reactive superoxide species-independent apoptosis in murine prostate cells.

PubMed

Kumar, Sanjay; Stokes, James; Singh, Udai P; Scissum-Gunn, Karyn; Singh, Rajesh; Manne, Upender; Mishra, Manoj K

2017-10-01

Nitric oxide, a signaling molecule, inhibits mitochondrial respiration by binding with cytochrome c oxidase, resulting in elevated production of reactive superoxide species (reactive oxygen and nitrogen) in the mitochondria and increased susceptibility to cell death. Generation of mitochondrial superoxide species can be suppressed by natural compounds such as resveratrol, a dietary polyphenol found in the skin of red fruits. In various cancer cells, resveratrol shows anti-oxidant and cancer preventive properties. Since, the effect of resveratrol on reactive superoxide species-independent apoptosis in prostate cancer cells is not well illustrated; therefore, we investigated this phenomenon in TRAMP murine prostate cancer cells. To accomplish this, TRAMP cells were incubated with resveratrol, resveratrol + DETA-NONOate, DETA-NONOate (nitric oxide donor), resveratrol + L-NMMA, or L-NMMA (nitric oxide inhibitor) for 48 h, and reactive superoxide species in the mitochondria and culture supernatant were measured. In addition, the mitochondrial membrane potential, cell viability, expression of apoptotic markers (Bax and Bcl2), γ-H2A.x, p53, and caspase-3 was determined. We found that resveratrol suppressed reactive superoxide species such as reactive oxygen species in the mitochondria and nitric oxide in culture supernatant when compared to the DETA-NONOate treatment and disrupted the mitochondrial membrane potential. Resveratrol also reduced cell viability, altered the expression of apoptotic markers (Bax and Bcl2), and increased expression of γ-H2A.x (indicative marker of DNA fragmentation) and p53 (a critical DNA damage response protein). However, there was no appreciable modulation of the caspase-3. Therefore, our data suggest that resveratrol induces superoxide species-independent apoptosis and may act as a therapeutic agent against prostate cancer.

Gene expression profiles of Aspergillus flavus isolates responding to oxidative stress in different culture media

USDA-ARS?s Scientific Manuscript database

Aflatoxin contamination of peanut by Aspergillus flavus is exacerbated by drought stress. Drought also stimulates the production of reactive oxygen species (ROS) in plant tissues implying a correlation between ROS and aflatoxin production. Here, we performed gene expression analysis by RNAseq of tox...

NADPH Oxidase 5 Is a Pro-Contractile Nox Isoform and a Point of Cross-Talk for Calcium and Redox Signaling-Implications in Vascular Function.

PubMed

Montezano, Augusto C; De Lucca Camargo, Livia; Persson, Patrik; Rios, Francisco J; Harvey, Adam P; Anagnostopoulou, Aikaterini; Palacios, Roberto; Gandara, Ana Caroline P; Alves-Lopes, Rheure; Neves, Karla B; Dulak-Lis, Maria; Holterman, Chet E; de Oliveira, Pedro Lagerblad; Graham, Delyth; Kennedy, Christopher; Touyz, Rhian M

2018-06-15

NADPH Oxidase 5 (Nox5) is a calcium-sensitive superoxide-generating Nox. It is present in lower forms and higher mammals, but not in rodents. Nox5 is expressed in vascular cells, but the functional significance remains elusive. Given that contraction is controlled by calcium and reactive oxygen species, both associated with Nox5, we questioned the role of Nox5 in pro-contractile signaling and vascular function. Transgenic mice expressing human Nox5 in a vascular smooth muscle cell-specific manner (Nox5 mice) and Rhodnius prolixus , an arthropod model that expresses Nox5 endogenoulsy, were studied. Reactive oxygen species generation was increased systemically and in the vasculature and heart in Nox5 mice. In Nox5-expressing mice, agonist-induced vasoconstriction was exaggerated and endothelium-dependent vasorelaxation was impaired. Vascular structural and mechanical properties were not influenced by Nox5. Vascular contractile responses in Nox5 mice were normalized by N -acetylcysteine and inhibitors of calcium channels, calmodulin, and endoplasmic reticulum ryanodine receptors, but not by GKT137831 (Nox1/4 inhibitor). At the cellular level, vascular changes in Nox5 mice were associated with increased vascular smooth muscle cell [Ca 2+ ] i , increased reactive oxygen species and nitrotyrosine levels, and hyperphosphorylation of pro-contractile signaling molecules MLC20 (myosin light chain 20) and MYPT1 (myosin phosphatase target subunit 1). Blood pressure was similar in wild-type and Nox5 mice. Nox5 did not amplify angiotensin II effects. In R. prolixus , gastrointestinal smooth muscle contraction was blunted by Nox5 silencing, but not by VAS2870 (Nox1/2/4 inhibitor). Nox5 is a pro-contractile Nox isoform important in redox-sensitive contraction. This involves calcium-calmodulin and endoplasmic reticulum-regulated mechanisms. Our findings define a novel function for vascular Nox5, linking calcium and reactive oxygen species to the pro-contractile molecular machinery in vascular smooth muscle cells. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Reciprocal Regulation of Reactive Oxygen Species and Phospho-CREB Regulates Voltage Gated Calcium Channel Expression during Mycobacterium tuberculosis Infection

PubMed Central

Selvakumar, Arti; Antony, Cecil; Singhal, Jhalak; Tiwari, Brijendra K.; Singh, Yogendra; Natarajan, Krishnamurthy

2014-01-01

Our previous work has demonstrated the roles played by L-type Voltage Gated Calcium Channels (VGCC) in regulating Mycobacterium tuberculosis (M. tb) survival and pathogenesis. Here we decipher mechanisms and pathways engaged by the pathogen to regulate VGCC expression in macrophages. We show that M. tb and its antigen Rv3416 use phospho-CREB (pCREB), Reactive Oxygen Species (ROS), Protein Kinase C (PKC) and Mitogen Activated Protein Kinase (MAPK) to modulate VGCC expression in macrophages. siRNA mediated knockdown of MyD88, IRAK1, IRAK2 or TRAF6 significantly inhibited antigen mediated VGCC expression. Inhibiting Protein Kinase C (PKC) or MEK-ERK1/2 further increased VGCC expression. Interestingly, inhibiting intracellular calcium release upregulated antigen mediated VGCC expression, while inhibiting extracellular calcium influx had no significant effect. siRNA mediated knockdown of transcription factors c-Jun, SOX5 and CREB significantly inhibited Rv3416 mediated VGCC expression. A dynamic reciprocal cross-regulation between ROS and pCREB was observed that in turn governed VGCC expression with ROS playing a limiting role in the process. Further dissection of the mechanisms such as the interplay between ROS and pCREB would improve our understanding of the regulation of VGCC expression during M. tb infection. PMID:24797940

Eckol protects V79-4 lung fibroblast cells against gamma-ray radiation-induced apoptosis via the scavenging of reactive oxygen species and inhibiting of the c-Jun NH(2)-terminal kinase pathway.

PubMed

Zhang, Rui; Kang, Kyoung Ah; Piao, Mei Jing; Ko, Dong Ok; Wang, Zhi Hong; Lee, In Kyung; Kim, Bum Joon; Jeong, Il Yun; Shin, Taekyun; Park, Jae Woo; Lee, Nam Ho; Hyun, Jin Won

2008-09-04

The radioprotective effect of eckol against gamma-ray radiation-induced oxidative stress and its possible protective mechanisms were investigated. Eckol was found to reduce the intracellular reactive oxygen species generated by gamma-ray radiation. Moreover, eckol also protected against radiation-induced cellular DNA damage and membrane lipid peroxidation, which are the main targets of radiation-induced damage. In addition, eckol recovered the cell viability damaged by radiation via the inhibition of apoptosis. Irradiated cells with eckol treatment reduced the expression of bax, the activation of caspase 9 and caspase 3, which were induced by radiation. However, irradiated cells with eckol recovered the expression of bcl-2 and mitochondrial cytochrome c which were decreased by radiation. The anti-apoptotic effect of eckol exerted via the inhibition of mitogen-activated protein kinase kinase-4 (MKK4/SEK1)-c-Jun NH(2)-terminal kinase (JNK)-activator protein 1 (AP-1) cascades induced by radiation. In summary, the results suggest that eckol protects cells against the oxidative stress induced by radiation via the reduction of reactive oxygen species and the attenuation of activation in SEK1-JNK-AP-1 pathway.

The origins of marine bioluminescence: turning oxygen defence mechanisms into deep-sea communication tools.

PubMed

Rees, J F; de Wergifosse, B; Noiset, O; Dubuisson, M; Janssens, B; Thompson, E M

1998-04-01

Bioluminescence, the emission of ecologically functional light by living organisms, emerged independently on several occasions, yet the evolutionary origins of most bioluminescent systems remain obscure. We propose that the luminescent substrates of the luminous reactions (luciferins) are the evolutionary core of most systems, while luciferases, the enzymes catalysing the photogenic oxidation of the luciferin, serve to optimise the expression of the endogenous chemiluminescent properties of the luciferin. Coelenterazine, a luciferin occurring in many marine bioluminescent groups, has strong antioxidative properties as it is highly reactive with reactive oxygen species such as the superoxide anion or peroxides. We suggest that the primary function of coelenterazine was originally the detoxification of the deleterious oxygen derivatives. The functional shift from its antioxidative to its light-emitting function might have occurred when the strength of selection for antioxidative defence mechanisms decreased. This might have been made possible when marine organisms began colonising deeper layers of the oceans, where exposure to oxidative stress is considerably reduced because of reduced light irradiance and lower oxygen levels. A reduction in metabolic activity with increasing depth would also have decreased the endogenous production of reactive oxygen species. Therefore, in these organisms, mechanisms for harnessing the chemiluminescence of coelenterazine in specialised organs could have developed, while the beneficial antioxidative properties were maintained in other tissues. The full range of graded irradiance in the mesopelagic zone, where the majority of organisms are bioluminescent, would have provided a continuum for the selection and improvement of proto-bioluminescence. Although the requirement for oxygen or reactive oxygen species observed in bioluminescent systems reflects the high energy required to produce visible light, it may suggest that oxygen-detoxifying mechanisms provided excellent foundations for the emergence of many bioluminescent systems.

Expression of NADPH Oxidase Isoform 1 (Nox1) in Human Placenta: Involvement in Preeclampsia

PubMed Central

Cui, X.-L.; Brockman, D.; Campos, B.; Myatt, L.

2010-01-01

Increased oxidative stress in the placenta has been associated with preeclampsia (PE), a clinical syndrome involving placental pathology. The enzymatic sources of reactive oxygen species in the human placenta are as yet unidentified. We hypothesized that NADPH oxidase is a main source of reactive oxygen species in the placenta and its expression may change in PE. Employing RTPCR, we have amplified a novel NADPH oxidase isoform Nox1 from human choriocarcinoma BeWo cells. Using polyclonal anti-peptide antiserum recognizing unique Nox1 peptide sequences, we identified by immunohistochemistry and cell fractionation that Nox1 protein localizes in the BeWo cell membrane structures. Immunohistochemistry of normal placental tissues showed that Nox1 was localized in syncytiotrophoblasts, in villous vascular endothelium, and in some stromal cells. At the immunohistochemical level Nox1 expression was significantly increased in syncytiotrophoblast and endothelial cells in placentas from patients with preeclampsia as compared to gestational age-matched controls. Western blot analysis of whole placental homogenate confirmed this increase. Our data suggests that increased Nox1 expression is associated with the increased oxidative stress found in these placentas. PMID:15993942

Expression and characterization of recombinant bifunctional enzymes with glutathione peroxidase and superoxide dismutase activities.

PubMed

Guan, Tuchen; Song, Jian; Wang, Yanan; Guo, Liying; Yuan, Lin; Zhao, Yingding; Gao, Yuan; Lin, Liangru; Wang, Yali; Wei, Jingyan

2017-09-01

To balance the production and decomposition of reactive oxygen species, living organisms have generated antioxidant enzymes and non-enzymatic antioxidant defense systems. Glutathione peroxidase (GPx) and superoxide dismutase (SOD) are two important antioxidant enzymes. Apart from their catalytic functions, they protect each other, resulting in more efficient removal of reactive oxygen species, protection of cells against injury, and maintenance of the normal metabolism of reactive oxygen species. SOD catalyzes the dismutation of the superoxide anion (O 2 •- ) to oxygen (O 2 ) and hydrogen peroxide (H 2 O 2 ). H 2 O 2 is then detoxified to water by GPx. In this study, human GPx1 Ser and the Alvinella pompejana SOD (ApSOD) gene were used to design and generate several recombinant proteins with both GPx and SOD activities by combining traditional fusion protein technology, a cysteine auxotrophic expression system, and a single protein production (SPP) system. Among the fusion proteins, Se-hGPx1 Ser -L-ApSOD exhibited the highest SOD and GPx activities. Additional research was conducted to better understand the properties of Se-hGPx1 Ser -L-ApSOD. The synergism of Se-hGPx1 Ser -L-ApSOD was evaluated by using an in vitro model. This research may facilitate future studies on the cooperation and catalytic mechanisms of GPx and SOD. We believe that the bifunctional enzyme has potential applications as a potent antioxidant. Copyright © 2017 Elsevier Inc. All rights reserved.

Increased expression of matrix metalloproteinase-1 in systemic vessels of preeclamptic women: a critical mediator of vascular dysfunction.

PubMed

Estrada-Gutierrez, Guadalupe; Cappello, Renato E; Mishra, Nikita; Romero, Roberto; Strauss, Jerome F; Walsh, Scott W

2011-01-01

This study was conducted to determine the following: (1) whether matrix metalloproteinase-1 (MMP-1) is increased in systemic vessels of preeclamptic women, (2) whether this increase might be mediated by neutrophils, and (3) whether MMP-1 could be responsible for vascular dysfunction. Omental arteries and plasma were collected from healthy pregnant and preeclamptic women. Omental arteries were evaluated for gene and protein expression of MMP-1, collagen type 1α, tissue inhibitor of metalloproteinase-1, and vascular reactivity to MMP-1. Gene and protein expression levels were also evaluated in human vascular smooth muscle cells (VSMCs) co-cultured with activated neutrophils, reactive oxygen species, or tumor necrosis factor α. Vessel expression of MMP-1 and circulating MMP-1 levels were increased in preeclamptic women, whereas vascular expression of collagen or tissue inhibitor of metalloproteinase-1 were down-regulated or unchanged. In cultured VSMCs, the imbalance in collagen-regulating genes of preeclamptic vessels was reproduced by treatment with neutrophils, tumor necrosis factor α, or reactive oxygen species. Chemotaxis studies with cultured cells revealed that MMP-1 promoted recruitment of neutrophils via vascular smooth muscle release of interleukin-8. Furthermore, MMP-1 induced vasoconstriction via protease-activated receptor-1, whose expression was significantly increased in omental arteries of preeclamptic women and in VSMCs co-cultured with neutrophils. Collectively, these findings disclose a novel role for MMP-1 as a mediator of vasoconstriction and vascular dysfunction in preeclampsia. Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

TMEM16A Contributes to Endothelial Dysfunction by Facilitating Nox2 NADPH Oxidase-Derived Reactive Oxygen Species Generation in Hypertension.

PubMed

Ma, Ming-Ming; Gao, Min; Guo, Kai-Min; Wang, Mi; Li, Xiang-Yu; Zeng, Xue-Lin; Sun, Lu; Lv, Xiao-Fei; Du, Yan-Hua; Wang, Guan-Lei; Zhou, Jia-Guo; Guan, Yong-Yuan

2017-05-01

Ca 2+ -activated Cl - channels play a crucial role in various physiological processes. However, the role of TMEM16A in vascular endothelial dysfunction during hypertension is unclear. In this study, we investigated the specific involvement of TMEM16A in regulating endothelial function and blood pressure and the underlying mechanism. Reverse transcription-polymerase chain reaction, Western blotting, coimmunoprecipitation, confocal imaging, patch-clamp recordings, and TMEM16A endothelial-specific transgenic and knockout mice were used. We found that TMEM16A was expressed abundantly and functioned as a Ca 2+ -activated Cl - channel in endothelial cells. Angiotensin II induced endothelial dysfunction with an increase in TMEM16A expression. The knockout of endothelial-specific TMEM16A significantly lowered the blood pressure and ameliorated endothelial dysfunction in angiotensin II-induced hypertension, whereas the overexpression of endothelial-specific TMEM16A resulted in the opposite effects. These results were related to the increased reactive oxygen species production, Nox2-containing NADPH oxidase activation, and Nox2 and p22phox protein expression that were facilitated by TMEM16A on angiotensin II-induced hypertensive challenge. Moreover, TMEM16A directly bound with Nox2 and reduced the degradation of Nox2 through the proteasome-dependent degradation pathway. Therefore, TMEM16A is a positive regulator of endothelial reactive oxygen species generation via Nox2-containing NADPH oxidase, which induces endothelial dysfunction and hypertension. Modification of TMEM16A may be a novel therapeutic strategy for endothelial dysfunction-associated diseases. © 2017 American Heart Association, Inc.

Pancreatic two P domain K+ channels TALK-1 and TALK-2 are activated by nitric oxide and reactive oxygen species

PubMed Central

Duprat, F; Girard, C; Jarretou, G; Lazdunski, M

2005-01-01

This study firstly shows with in situ hybridization on human pancreas that TALK-1 and TALK-2, two members of the 2P domain potassium channel (K2P) family, are highly and specifically expressed in the exocrine pancreas and absent in Langherans islets. On the contrary, expression of TASK-2 in mouse pancreas is found both in the exocrine pancreas and in the Langherans islets. This study also shows that TALK-1 and TALK-2 channels, expressed in Xenopus oocytes, are strongly and specifically activated by nitric oxide (obtained with a mixture of sodium nitroprussate (SNP) and dithiothreitol (DTT)), superoxide anion (obtained with xanthine and xanthine oxidase) and singlet oxygen (obtained upon photoactivation of rose bengal, and with chloramine T). Other nitric oxide and reactive oxygen species (NOS and ROS) donors, as well as reducing conditions were found to be ineffective on TALK-1, TALK-2 and TASK-2 (sin-1, angeli's salt, SNP alone, tBHP, H2O2, and DTT). These results suggest that, in the exocrine pancreas, specific members of the NOS and ROS families could act as endogenous modulators of TALK channels with a role in normal secretion as well as in disease states such as acute pancreatitis and apoptosis. PMID:15513946

Decreased platelet inhibition by nitric oxide in two brothers with a history of arterial thrombosis.

PubMed Central

Freedman, J E; Loscalzo, J; Benoit, S E; Valeri, C R; Barnard, M R; Michelson, A D

1996-01-01

Highly reactive oxygen species rapidly inactivate nitric oxide (NO), and endothelial product which inhibits platelet activation. We studied platelet inhibition by NO in two brothers with a cerebral thrombotic disorder. Both children had hyperreactive platelets, as determined by whole blood platelet aggregometry and flow cytometric analysis of the platelet surface expression of P-selectin. Mixing experiments showed that the patients'platelets behaved normally in control plasma; however, control platelets suspended in patient plasma were not inhibited by NO. As determined by flow cytometry, in the presence of plasma from either patient there was normal inhibition of the thrombin-induced expression of platelet surface P-selectin by prostacyclin, but not NO. Using a scopoletin assay, we measured a 2.7-fold increase in plasma H2O2 generation in one patient and a 3.4-fold increase in the second patient, both compared woth control plasma. Glutathione peroxidase (GSH-Px) activity was decreased in the patients' plasmas compared with control plasma. The addition of exogenous GSH-Px led to restoration of platelet inhibition by NO. These data show that, in these patients' plasmas, impaired metabolism of reactive oxygen species reduces the bioavailability of NO and impairs normal platelet inhibitory mechanisms. These findings suggest that attenuated NO-mediated platelet inhibition produced by increased reactive oxygen species or impaired antioxidant defense may cause a thrombotic disorder in humans. PMID:8613552

Phenyl-alpha-tert-butyl nitrone reverses mitochondrial decay in acute Chagas' disease.

PubMed

Wen, Jian-Jun; Bhatia, Vandanajay; Popov, Vsevolod L; Garg, Nisha Jain

2006-12-01

In this study, we investigated the mechanism(s) of mitochondrial functional decline in acute Chagas' disease. Our data show a substantial decline in respiratory complex activities (39 to 58%) and ATP (38%) content in Trypanosoma cruzi-infected murine hearts compared with normal controls. These metabolic alterations were associated with an approximately fivefold increase in mitochondrial reactive oxygen species production rate, substantial oxidative insult of mitochondrial membranes and respiratory complex subunits, and >60% inhibition of mtDNA-encoded transcripts for respiratory complex subunits in infected myocardium. The antioxidant phenyl-alpha-tert-butyl nitrone (PBN) arrested the oxidative damage-mediated loss in mitochondrial membrane integrity, preserved redox potential-coupled mitochondrial gene expression, and improved respiratory complex activities (47 to 95% increase) and cardiac ATP level (>or=40% increase) in infected myocardium. Importantly, PBN resulted twofold decline in mitochondrial reactive oxygen species production rate in infected myocardium. Taken together, our data demonstrate the pathological significance of oxidative stress in metabolic decay and energy homeostasis in acute chagasic myocarditis and further suggest that oxidative injuries affecting mitochondrial integrity-dependent expression and activity of the respiratory complexes initiate a feedback cycle of electron transport chain inefficiency, increased reactive oxygen species production, and energy homeostasis in acute chagasic hearts. PBN and other mitochondria-targeted antioxidants may be useful in altering mitochondrial decay and oxidative pathology in Chagas' disease.

Effects of Gingko biloba extract (EGb 761) on vascular smooth muscle cell calcification induced by β-glycerophosphate.

PubMed

Li, En-Gang; Tian, Jun; Xu, Zhong-Hua

2016-01-01

To investigate the effects of Gingko biloba extract (EGb 761) on calcification induced by β-glycerophosphate in rat aortic vascular smooth muscle cells. Rat aortic vascular smooth muscle cells were cultured with various concentrations of EGb 761 and β-glycerophosphate for 7 days. Calcium content in the cells, alkaline phosphatase activity, cell protein content, NF-κB activation, and reactive oxygen species production were assayed, respectively. The calcium depositions of vascular smooth muscle cells of the β-glycerophosphate group were significantly higher than those of the control group (p < 0.01), and were inhibited by EGb 761 in a concentration-dependent manner (p < 0.05). Data showed β-glycerophosphate induced the enhanced expression of alkaline phosphatase, up-regulated the NF-κB activity and increased reactive oxygen species production of vascular smooth muscle cells while these decreased when administrated with EGb 761(p < 0.05). EGb 761 significantly reduced deposition of calcium induced by β-glycerophosphate in rat aortic vascular smooth muscle cells. It not only reduced the deposition of calcium, but also inhibited osteogenic transdifferentiation, which may be associated with decreasing expression of alkaline phosphatase, down-regulating the NF-κB activity, and reducing reactive oxygen species production of vascular smooth muscle cells, and may have the potential to serve as a role for vascular calcification in clinical situations.

The partial pressure of oxygen affects biomarkers of oxidative stress in cultured rainbow trout (Oncorhynchus mykiss) hepatocytes.

PubMed

Finne, E F; Olsvik, P A; Berntssen, M H G; Hylland, K; Tollefsen, K E

2008-09-01

Oxidative stress, the imbalance between production of reactive oxygen species and the cellular detoxification of these reactive compounds, is believed to be involved in the pathology of various diseases. Several biomarkers for oxidative stress have been proposed to serve as tools in toxicological and ecotoxicological research. Not only may exposure to various pro-oxidants create conditions of cellular oxidative stress, but hyperoxic conditions may also increase the production of reactive oxygen species. The objective of the current study was to determine the extent to which differences in oxygen partial pressure would affect biomarkers of oxidative stress in a primary culture of hepatocytes from rainbow trout (Oncorhynchus mykiss). Membrane integrity, metabolic activity, levels of total and oxidized glutathione (tGSH/GSSG) was determined, as well as mRNA expression levels of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GSSG-R), gamma-glutamyl-cystein synthetase (GCS) and thioredoxin (TRX). The results show that different biomarkers of oxidative stress are affected when the cell culture is exposed to atmospheric oxygen, and that changes such as increased GSSG content and induction of GSSG-R and GSH-Px can be reduced by culturing the cells under lower oxygen tension. Oxygen tension may thus influence results of in vitro based cell research and is particularly important when assessing parameters in the antioxidant defence system. Further research is needed to establish the magnitude of this effect in different cellular systems.

Mono-(2-Ethylhexyl) Phthalate Induces Injury in Human Umbilical Vein Endothelial Cells

PubMed Central

Huang, Qi; Li, Bin-Feng; Chen, Chen; Zhang, Hua-Chuan; Xu, Shun-Qing

2014-01-01

Mono-(2-ethylhexyl) phthalate (MEHP), the active metabolite of di-(2-ethylhexyl) phthalate (DEHP), is a widespread environmental contaminant and has been proved to have potential adverse effects on the reproductive system, carcinogenicity, liver, kidney and developmental toxicities. However, the effect of MEHP on vascular system remains unclear. The main purpose of this study was to evaluate the cytotoxic effects of MEHP on human umbilical endothelial cells (HUVEC) and its possible molecular mechanism. HUVEC cells were treated with MEHP (0, 6.25, 12.5, 25,50 and 100 µM), and the cellular apoptosis and mitochondrial membrane potential as well as intracellular reactive oxygen species were determined. In present study, MEHP induced a dose-dependent cell injury in HUVEC cell via an apoptosis pathway as characterized by increased percentage of sub-G1, activation of caspase-3, -8and -9, and increased ratio of Bax/bcl-2 mRNA and protein expression as well as cytochrome C releasing. In addition, there was obvious oxidative stress, represented by decreased glutathione level, increased malondialdehyde level and superoxide dismutase activity. N-Acetylcysteine, as an antioxidant that is a direct reactive oxygen species scavenger, could effectively block MEHP-induced reactive oxygen species generation, mitochondrial membrane potential loss and cell apoptosis. These data indicated that MEHP induced apoptosis in HUVEC cells through a reactive oxygen species-mediated mitochondria-dependent pathway. PMID:24836450

NQO2 Is a Reactive Oxygen Species Generating Off-Target for Acetaminophen

PubMed Central

2014-01-01

The analgesic and antipyretic compound acetaminophen (paracetamol) is one of the most used drugs worldwide. Acetaminophen overdose is also the most common cause for acute liver toxicity. Here we show that acetaminophen and many structurally related compounds bind quinone reductase 2 (NQO2) in vitro and in live cells, establishing NQO2 as a novel off-target. NQO2 modulates the levels of acetaminophen derived reactive oxygen species, more specifically superoxide anions, in cultured cells. In humans, NQO2 is highly expressed in liver and kidney, the main sites of acetaminophen toxicity. We suggest that NQO2 mediated superoxide production may function as a novel mechanism augmenting acetaminophen toxicity. PMID:25313982

Anti-inflammatory effects of Chinese medicinal herbs on cerebral ischemia.

PubMed

Su, Shan-Yu; Hsieh, Ching-Liang

2011-07-09

Recent studies have demonstrated the importance of anti-inflammation, including cellular immunity, inflammatory mediators, reactive oxygen species, nitric oxide and several transcriptional factors, in the treatment of cerebral ischemia. This article reviews the roles of Chinese medicinal herbs as well as their ingredients in the inflammatory cascade induced by cerebral ischemia. Chinese medicinal herbs exert neuroprotective effects on cerebral ischemia. The effects include inhibiting the activation of microglia, decreasing levels of adhesion molecules such as intracellular adhesion molecule-1, attenuating expression of pro-inflammatory cytokines such as interleukin-1β and tumor necrosis factor-α, reducing inducible nitric oxide synthase and reactive oxygen species, and regulating transcription factors such as nuclear factor-κB.

Induction of Sirt1 by Mechanical Stretch of Skeletal Muscle through the Early Response Factor EGR1 Triggers an Antioxidative Response*

PubMed Central

Pardo, Patricia S.; Mohamed, Junaith S.; Lopez, Michael A.; Boriek, Aladin M.

2011-01-01

Mechanical loading of muscles by intrinsic muscle activity or passive stretch leads to an increase in the production of reactive oxygen species (1, 2). The NAD-dependent protein deacetylase SIRT1 is involved in the protection against oxidative stress by enhancing FOXO-driven Sod2 transcription (3–5). In this report, we unravel a mechanism triggered by mechanical stretch of skeletal muscle cells that leads to an EGR1-dependent transcriptional activation of the Sirt1 gene. The resulting transient increase in SIRT1 expression generates an antioxidative response that contributes to reactive oxygen species scavenging. PMID:20971845

Contrasted Reactivity to Oxygen Tensions in Frankia sp. Strain CcI3 throughout Nitrogen Fixation and Assimilation

PubMed Central

Ghodhbane-Gtari, Faten; Hezbri, Karima; Ktari, Amir; Sbissi, Imed; Beauchemin, Nicholas; Gtari, Maher; Tisa, Louis S.

2014-01-01

Reconciling the irreconcilable is a primary struggle in aerobic nitrogen-fixing bacteria. Although nitrogenase is oxygen and reactive oxygen species-labile, oxygen tension is required to sustain respiration. In the nitrogen-fixing Frankia, various strategies have been developed through evolution to control the respiration and nitrogen-fixation balance. Here, we assessed the effect of different oxygen tensions on Frankia sp. strain CcI3 growth, vesicle production, and gene expression under different oxygen tensions. Both biomass and vesicle production were correlated with elevated oxygen levels under both nitrogen-replete and nitrogen-deficient conditions. The mRNA levels for the nitrogenase structural genes (nifHDK) were high under hypoxic and hyperoxic conditions compared to oxic conditions. The mRNA level for the hopanoid biosynthesis genes (sqhC and hpnC) was also elevated under hyperoxic conditions suggesting an increase in the vesicle envelope. Under nitrogen-deficient conditions, the hup2 mRNA levels increased with hyperoxic environment, while hup1 mRNA levels remained relatively constant. Taken together, these results indicate that Frankia protects nitrogenase by the use of multiple mechanisms including the vesicle-hopanoid barrier and increased respiratory protection. PMID:24987692

Comparative effects of conjugated linoleic acid (CLA) and linoleic acid (LA) on the oxidoreduction status in THP-1 macrophages.

PubMed

Rybicka, Marta; Stachowska, Ewa; Gutowska, Izabela; Parczewski, Miłosz; Baśkiewicz, Magdalena; Machaliński, Bogusław; Boroń-Kaczmarska, Anna; Chlubek, Dariusz

2011-04-27

The aim of this study was to investigate the effect of conjugated linoleic acids (CLAs) on macrophage reactive oxygen species synthesis and the activity and expression of antioxidant enzymes, catalase (Cat), glutathione peroxidase (GPx), and superoxide dismutase (SOD). The macrophages were obtained from the THP-1 monocytic cell line. Cells were incubated with the addition of cis-9,trans-11 CLA or trans-10,cis-12 CLA or linoleic acid. Reactive oxygen species (ROS) formation was estimated by flow cytometry. Enzymes activity was measured spectrophotometrically. The antioxidant enzyme mRNA expression was estimated by real-time reverse transcriptase polymerase chain reaction (RT-PCR). Statistical analysis was based on nonparametric statistical tests [Friedman analysis of variation (ANOVA) and Wilcoxon signed-rank test]. cis-9,trans-11 CLA significantly increased the activity of Cat, while trans-10,cis-12 CLA notably influenced GPx activity. Both isomers significantly decreased mRNA expression for Cat. Only trans-10,cis-12 significantly influenced mRNA for SOD-2 expression. The CLAs activate processes of the ROS formation in macrophages. Adverse metabolic effects of each isomer action were observed.

Inverse correlation between reactive oxygen species in unwashed semen and sperm motion parameters as measured by a computer-assisted semen analyzer.

PubMed

Takeshima, Teppei; Yumura, Yasushi; Yasuda, Kengo; Sanjo, Hiroyuki; Kuroda, Shinnosuke; Yamanaka, Hiroyuki; Iwasaki, Akira

2017-01-01

This study investigated the correlation between sperm motion parameters obtained by a computer-assisted semen analyzer and levels of reactive oxygen species in unwashed semen. In total, 847 patients, except for azoospermic patients were investigated. At the time of each patient's first consultation, semen parameters were measured using SMAS™ or CellSoft 3000™, and production of reactive oxygen species was measured using a computer-driven LKB Wallac Luminometer 1251 Analyzer. The patients were divided into two groups: reactive oxygen species - positive and negative. The semen parameters within each group were measured using one of the two computer-assisted semen analyzer systems and then compared. Correlations between reactive oxygen species levels and sperm motion parameters in semen from the reactive oxygen species - positive group were also investigated. Reactive oxygen species were detected in semen samples of 282 cases (33.3%). Sperm concentration (P < 0.01; P < 0.01), motility (P < 0.01; P < 0.05), and progressive motility (P < 0.01; P < 0.01) were markedly lower in the reactive oxygen species - positive group than in the reactive oxygen species - negative group. Among the sperm motion parameters in the reactive oxygen species - positive group, sperm concentration (P < 0.01; P < 0.01), motility (P < 0.05; P < 0.01), mALH (P < 0.05; P < 0.01), and progressive motility (P < 0.05; P < 0.01) also showed inverse correlations with the logarithmic transformed reactive oxygen species levels. Therefore, this study demonstrated that excessive reactive oxygen species in semen damage sperm concentration, motility, and other sperm motion parameters.

NADPH Oxidase as a Therapeutic Target for Oxalate Induced Injury in Kidneys

PubMed Central

Peck, Ammon B.; Khan, Saeed R.

2013-01-01

A major role of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase family of enzymes is to catalyze the production of superoxides and other reactive oxygen species (ROS). These ROS, in turn, play a key role as messengers in cell signal transduction and cell cycling, but when they are produced in excess they can lead to oxidative stress (OS). Oxidative stress in the kidneys is now considered a major cause of renal injury and inflammation, giving rise to a variety of pathological disorders. In this review, we discuss the putative role of oxalate in producing oxidative stress via the production of reactive oxygen species by isoforms of NADPH oxidases expressed in different cellular locations of the kidneys. Most renal cells produce ROS, and recent data indicate a direct correlation between upregulated gene expressions of NADPH oxidase, ROS, and inflammation. Renal tissue expression of multiple NADPH oxidase isoforms most likely will impact the future use of different antioxidants and NADPH oxidase inhibitors to minimize OS and renal tissue injury in hyperoxaluria-induced kidney stone disease. PMID:23840917

Prenatal Nicotine Increases Matrix Metalloproteinase 2 (MMP-2) Expression in Fetal Guinea Pig Hearts

PubMed Central

Thompson, Loren P.; Liu, Hongshan; Evans, LaShauna; Mong, Jessica A.

2011-01-01

This study tested the hypothesis that maternal nicotine ingestion increases matrix metalloproteinase (MMP) expression in fetal hearts, which is mediated by the generation of reactive oxygen species. Timed pregnant guinea pigs were administered either water alone, nicotine (200 μg/mL), N-acetylcysteine (NAC), or nicotine plus NAC in their drinking water for 10 days at 52-day gestation (term = 65 days). Near-term (62 days), anesthetized fetuses were extracted, hearts were excised, and left cardiac ventricles snap frozen for analysis of MMP-2/-9/-13 protein and activity levels. Interstitial collagens were identified by Picrosirius red stain to assess changes in the extracellular matrix. Prenatal nicotine increased active MMP-2 forms and interstitial collagen but had no effect on either pro- or active MMP-9 or MMP-13 forms. In the presence of nicotine, NAC decreased active MMP-2 protein levels and reversed the nicotine-induced increase in collagen staining. We conclude that prenatal nicotine alters MMP-2 expression in fetal hearts that may be mediated by reactive oxygen species generation. PMID:21775771

Tangeretin reduces ultraviolet B (UVB)-induced cyclooxygenase-2 expression in mouse epidermal cells by blocking mitogen-activated protein kinase (MAPK) activation and reactive oxygen species (ROS) generation.

PubMed

Yoon, Ji Hye; Lim, Tae-Gyu; Lee, Kyung Mi; Jeon, Ae Ji; Kim, Su Yeon; Lee, Ki Won

2011-01-12

The present study examined the effects of tangeretin, a polymethoxylated flavonone present in citrus fruits, on ultraviolet B (UVB)-induced cyclooxygenase-2 (COX-2) expression in JB6 P+ mouse skin epidermal cells. Tangeretin suppressed UVB-induced COX-2 expression and transactivation of nuclear factor-κB and activator protein-1 in JB6 P+ cells. Moreover, tangeretin blocked UVB-induced phosphorylation of Akt and mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated protein kinase, c-Jun N-terminal kinase, and p38, and attenuated the phosphorylation of MAPK kinases 1/2, 3/6, and 4. Tangeretin also limited the endogenous generation of reactive oxygen species (ROS), thereby protecting the cells against oxidative stress. However, tangeretin did not scavenge the stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and influence the nicotinamide adenine dinucleotide phosphate oxidase activity. These results suggest that the anti-inflammatory effects of tangeretin stem from its modulation of cell signaling and suppression of intracellular ROS generation. Tangeretin may have a potent chemopreventive effect in skin cancer.

Di-(2-ethylhexyl)-phthalate induces oxidative stress in human endometrial stromal cells in vitro.

PubMed

Cho, Yeon Jean; Park, Seung Bin; Han, Myoungseok

2015-05-15

Di-(2-ethylhexyl)-phthalate (DEHP) accumulates in the environment, and its exposure is possibly associated with endocrine-related disease in women of reproductive age. The effects of DEHP on human endometrial cells are unknown. We treated human endometrial stromal cells with 10, 100, and 1000 pmol of DEHP and measured reactive oxygen species (ROS) generation, expression levels of antioxidant enzymes, alteration of MAPK/NF-κB signaling and hormonal receptors. DEHP increased reactive oxygen species (ROS) generation and decreased expression of superoxide dismutase (SOD), glutathione peroxidase (GPX), heme oxygenase (HO), and catalase (CAT). By DEHP exposure, p-ERK/p-p38 and NF-κB mediated transcription was increased. Additionally, DEHP induced estrogen receptor-α (ER-α) expression in a dose-dependent manner. This study shows the need for future mechanistic studies of oxidative stress, MAPK/NF-κB signaling, and ER-α as molecular mediators of DEHP-associated endometrial stromal cell alterations, which may be associated with the development of endocrine-related disease such as endometriosis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Cytotoxicity and gene expression profiling of polyhexamethylene guanidine hydrochloride in human alveolar A549 cells.

PubMed

Jung, Ha-Na; Zerin, Tamanna; Podder, Biswajit; Song, Ho-Yeon; Kim, Yong-Sik

2014-06-01

In Korea, lung disease of children and pregnant women associated with humidifier disinfectant use has become a major concern. A common sterilizer is polyhexamethylene guanidine (PHMG), a member of the guanidine family of antiseptics. This study was done to elucidate the putative cytotoxic effect of PHMG and the PHMG-mediated altered gene expression in human alveolar epithelial A549 cells in vitro. Cell viability analyses revealed the potent cytotoxicity of PHMG, with cell death evident at as low as 5 μg/mL. Death was dose- and time-dependent, and was associated with formation of intracellular reactive oxygen species, and apoptosis significantly, at even 2 μg/mL concentration. The gene expression profile in A549 cells following 24 h exposure to 5 μg/mL of PHMG was investigated using DNA microarray analysis. Changes in gene expression relevant to the progression of cell death included induction of genes related to apoptosis, autophagy, fibrosis, and cell cycle. However, the expressions of genes encoding antioxidant and detoxifying enzymes were down-regulated or not affected. The altered expression of selected genes was confirmed by quantitative reverse transcription-polymerase chain reaction and Western blot analyses. The collective data suggest that PHMG confers cellular toxicity through the generation of intracellular reactive oxygen species and alteration of gene expression. Copyright © 2014 Elsevier Ltd. All rights reserved.

Overexpression of CaAPX Induces Orchestrated Reactive Oxygen Scavenging and Enhances Cold and Heat Tolerances in Tobacco

PubMed Central

Wang, Jiangying; Wu, Bin; Fan, Zhengqi; Li, Xinlei; Ni, Sui

2017-01-01

Ascorbate peroxidase (APX) acts indispensably in synthesizing L-ascorbate (AsA) which is pivotal to plant stress tolerance by detoxifying reactive oxygen species (ROS). Enhanced activity of APX has been shown to be a key step for genetic engineering of improving plant tolerance. However it needs a deeper understanding on the maintenance of cellular ROS homeostasis in response to stress. In this study, we identified and characterized an APX (CaAPX) gene from Camellia azalea. Quantitative real-time PCR (qRT-PCR) analysis showed that CaAPX was expressed in all tissues and peaked in immature green fruits; the expression levels were significantly upregulated upon cold and hot stresses. Transgenic plants displayed marked enhancements of tolerance under both cold and heat treatments, and plant growth was correlated with CaAPX expression levels. Furthermore, we monitored the activities of several ROS-scavenging enzymes including Cu/Zn-SOD, CAT, DHAR, and MDHAR, and we showed that stress tolerance was synchronized with elevated activities of ROS-scavenging. Moreover, gene expression analysis of ROS-scavenging enzymes revealed a role of CaAPX to orchestrate ROS signaling in response to temperature stresses. Overall, this study presents a comprehensive characterization of cellular response related to CaAPX expression and provides insights to breed crops with high temperature tolerances. PMID:28386551

Overexpression of CaAPX Induces Orchestrated Reactive Oxygen Scavenging and Enhances Cold and Heat Tolerances in Tobacco.

PubMed

Wang, Jiangying; Wu, Bin; Yin, Hengfu; Fan, Zhengqi; Li, Xinlei; Ni, Sui; He, Libo; Li, Jiyuan

2017-01-01

Ascorbate peroxidase (APX) acts indispensably in synthesizing L-ascorbate (AsA) which is pivotal to plant stress tolerance by detoxifying reactive oxygen species (ROS). Enhanced activity of APX has been shown to be a key step for genetic engineering of improving plant tolerance. However it needs a deeper understanding on the maintenance of cellular ROS homeostasis in response to stress. In this study, we identified and characterized an APX ( CaAPX ) gene from Camellia azalea . Quantitative real-time PCR (qRT-PCR) analysis showed that CaAPX was expressed in all tissues and peaked in immature green fruits; the expression levels were significantly upregulated upon cold and hot stresses. Transgenic plants displayed marked enhancements of tolerance under both cold and heat treatments, and plant growth was correlated with CaAPX expression levels. Furthermore, we monitored the activities of several ROS-scavenging enzymes including Cu/Zn-SOD , CAT , DHAR , and MDHAR , and we showed that stress tolerance was synchronized with elevated activities of ROS-scavenging. Moreover, gene expression analysis of ROS-scavenging enzymes revealed a role of CaAPX to orchestrate ROS signaling in response to temperature stresses. Overall, this study presents a comprehensive characterization of cellular response related to CaAPX expression and provides insights to breed crops with high temperature tolerances.

Trophoblast expression of the minor histocompatibility antigen HA-1 is regulated by oxygen and is increased in placentas from preeclamptic women.

PubMed

Linscheid, C; Heitmann, E; Singh, P; Wickstrom, E; Qiu, L; Hodes, H; Nauser, T; Petroff, M G

2015-08-01

Maternal T-cells reactive towards paternally inherited fetal minor histocompatibility antigens are expanded during pregnancy. Placental trophoblast cells express at least four fetal antigens, including human minor histocompatibility antigen 1 (HA-1). We investigated oxygen as a potential regulator of HA-1 and whether HA-1 expression is altered in preeclamptic placentas. Expression and regulation of HA-1 mRNA and protein were examined by qRT-PCR and immunohistochemistry, using first, second, and third trimester placentas, first trimester placental explant cultures, and term purified cytotrophoblast cells. Low oxygen conditions were achieved by varying ambient oxygen, and were mimicked using cobalt chloride. HA-1 mRNA and protein expression levels were evaluated in preeclamptic and control placentas. HA-1 protein expression was higher in the syncytiotrophoblast of first trimester as compared to second trimester and term placentas (P<0.01). HA-1 mRNA was increased in cobalt chloride-treated placental explants and purified cytotrophoblast cells (P = 0.04 and P<0.01, respectively) and in purified cytotrophoblast cells cultured under 2% as compared to 8% and 21% oxygen (P<0.01). HA-1 mRNA expression in preeclamptic vs. control placentas was increased 3.3-fold (P = 0.015). HA-1 protein expression was increased in syncytial nuclear aggregates and the syncytiotrophoblast of preeclamptic vs. control placentas (P = 0.02 and 0.03, respectively). Placental HA-1 expression is regulated by oxygen and is increased in the syncytial nuclear aggregates and syncytiotrophoblast of preeclamptic as compared to control placentas. Increased HA-1 expression, combined with increased preeclamptic syncytiotrophoblast deportation, provides a novel potential mechanism for exposure of the maternal immune system to increased fetal antigenic load during preeclampsia. Published by Elsevier Ltd.

Reactive Oxygen Species and Inhibitors of Inflammatory Enzymes, NADPH Oxidase, and iNOS in Experimental Models of Parkinson's Disease

PubMed Central

Koppula, Sushruta; Kumar, Hemant; Kim, In Su; Choi, Dong-Kug

2012-01-01

Reactive oxygen species (ROSs) are emerging as important players in the etiology of neurodegenerative disorders including Parkinson's disease (PD). Out of several ROS-generating systems, the inflammatory enzymes nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and inducible nitric oxide synthase (iNOS) were believed to play major roles. Mounting evidence suggests that activation of NADPH oxidase and the expression of iNOS are directly linked to the generation of highly reactive ROS which affects various cellular components and preferentially damage midbrain dopaminergic neurons in PD. Therefore, appropriate management or inhibition of ROS generated by these enzymes may represent a therapeutic target to reduce neuronal degeneration seen in PD. Here, we have summarized recently developed agents and patents claimed as inhibitors of NADPH oxidase and iNOS enzymes in experimental models of PD. PMID:22577256

Pitx2 promotes heart repair by activating the antioxidant response after cardiac injury

PubMed Central

Tao, Ge; Kahr, Peter C.; Morikawa, Yuka; Zhang, Min; Rahmani, Mahdis; Heallen, Todd R.; Li, Lele; Sun, Zhao; Olson, Eric N.; Amendt, Brad A.; Martin, James F.

2016-01-01

Summary Myocardial infarction results in compromised myocardial function with heart failure due to insufficient cardiomyocyte self-renewal1. Unlike lower vertebrates, mammalian hearts only have a transient neonatal renewal capacity2. Reactivating primitive reparative ability in the mature heart requires knowledge of the mechanisms promoting early heart repair. By testing an established Hippo-deficient heart regeneration model for renewal promoting factors, we found that Pitx2 expression was induced in injured, Hippo-deficient ventricles. Pitx2-deficient neonatal hearts failed to repair after apex resection while Pitx2-gain-of-function in adult cardiomyocytes conferred reparative ability after myocardial infarction. Genomic analyses indicated that Pitx2 activated genes encoding electron transport chain components and reactive oxygen species scavengers. A subset of Pitx2 target genes was cooperatively regulated with the Hippo effector, Yap. Furthermore, Nrf2, a regulator of antioxidant response3, directly regulated Pitx2 expression and subcellular localization. Pitx2 mutant myocardium had elevated reactive oxygen species levels while antioxidant supplementation suppressed the Pitx2-loss-of-function phenotype. These findings reveal a genetic pathway, activated by tissue damage that is essential for cardiac repair. PMID:27251288

Pitx2 promotes heart repair by activating the antioxidant response after cardiac injury.

PubMed

Tao, Ge; Kahr, Peter C; Morikawa, Yuka; Zhang, Min; Rahmani, Mahdis; Heallen, Todd R; Li, Lele; Sun, Zhao; Olson, Eric N; Amendt, Brad A; Martin, James F

2016-06-02

Myocardial infarction results in compromised myocardial function and heart failure owing to insufficient cardiomyocyte self-renewal. Unlike many vertebrates, mammalian hearts have only a transient neonatal renewal capacity. Reactivating primitive reparative ability in the mature mammalian heart requires knowledge of the mechanisms that promote early heart repair. By testing an established Hippo-deficient heart regeneration mouse model for factors that promote renewal, here we show that the expression of Pitx2 is induced in injured, Hippo-deficient ventricles. Pitx2-deficient neonatal mouse hearts failed to repair after apex resection, whereas adult mouse cardiomyocytes with Pitx2 gain-of-function efficiently regenerated after myocardial infarction. Genomic analyses indicated that Pitx2 activated genes encoding electron transport chain components and reactive oxygen species scavengers. A subset of Pitx2 target genes was cooperatively regulated with the Hippo pathway effector Yap. Furthermore, Nrf2, a regulator of the antioxidant response, directly regulated the expression and subcellular localization of Pitx2. Pitx2 mutant myocardium had increased levels of reactive oxygen species, while antioxidant supplementation suppressed the Pitx2 loss-of-function phenotype. These findings reveal a genetic pathway activated by tissue damage that is essential for cardiac repair.

Attenuation of NADPH oxidase activation and glomerular filtration barrier remodeling with statin treatment.

PubMed

Whaley-Connell, Adam; Habibi, Javad; Nistala, Ravi; Cooper, Shawna A; Karuparthi, Poorna R; Hayden, Melvin R; Rehmer, Nathan; DeMarco, Vincent G; Andresen, Bradley T; Wei, Yongzhong; Ferrario, Carlos; Sowers, James R

2008-02-01

Activation of reduced nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase by angiotensin II is integral to the formation of oxidative stress in the vasculature and the kidney. 3-Hydroxy-3-methylglutaryl-coenzyme A reductase inhibition is associated with reductions of oxidative stress in the vasculature and kidney and associated decreases in albuminuria. Effects of 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibition on oxidative stress in the kidney and filtration barrier integrity are poorly understood. To investigate, we used transgenic TG(mRen2)27 (Ren2) rats, which harbor the mouse renin transgene and renin-angiotensin system activation, and an immortalized murine podocyte cell line. We treated young, male Ren2 and Sprague-Dawley rats with rosuvastatin (20 mg/kg IP) or placebo for 21 days. Compared with controls, we observed increases in systolic blood pressure, albuminuria, renal NADPH oxidase activity, and 3-nitrotryosine staining, with reductions in the rosuvastatin-treated Ren2. Structural changes on light and transmission electron microscopy, consistent with periarteriolar fibrosis and podocyte foot-process effacement, were attenuated with statin treatment. Nephrin expression was diminished in the Ren2 kidney and trended to normalize with statin treatment. Angiotensin II-dependent increases in podocyte NADPH oxidase activity and subunit expression (NOX2, NOX4, Rac, and p22(phox)) and reactive oxygen species generation were decreased after in vitro statin treatment. These data support a role for increased NADPH oxidase activity and subunit expression with resultant reactive oxygen species formation in the kidney and podocyte. Furthermore, statin attenuation of NADPH oxidase activation and reactive oxygen species formation in the kidney/podocyte seems to play roles in the abrogation of oxidative stress-induced filtration barrier injury and consequent albuminuria.

Gelidium elegans, an edible red seaweed, and hesperidin inhibit lipid accumulation and production of reactive oxygen species and reactive nitrogen species in 3T3-L1 and RAW264.7 cells.

PubMed

Jeon, Hui-Jeon; Seo, Min-Jung; Choi, Hyeon-Son; Lee, Ok-Hwan; Lee, Boo-Yong

2014-11-01

Gelidium elegans is an edible red alga native to the intertidal area of northeastern Asia. We investigated the effect of G. elegans extract and its main flavonoids, rutin and hesperidin, on lipid accumulation and the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in 3T3-L1 and RAW264.7 cells. Our data show that G. elegans extract decreased lipid accumulation and ROS/RNS production in a dose-dependent manner. The extract also inhibited the mRNA expression of adipogenic transcription factors, such as peroxisome proliferator-activated receptor gamma and CCAAT/enhancer-binding protein alpha, while enhancing the protein expression of the antioxidant enzymes superoxide dismutases 1 and 2, glutathione peroxidase, and glutathione reductase compared with controls. In addition, lipopolysaccharide-induced nitric oxide production was significantly reduced in G. elegans extract-treated RAW264.7 cells. In analysis of the effects of G. elegans flavonoids on lipid accumulation and ROS/RNS production, only hesperidin showed an inhibitory effect on lipid accumulation and ROS production; rutin did not affect adipogenesis and ROS status. The antiadipogenic effect of hesperidin was evidenced by the downregulation of peroxisome proliferator-activated receptor gamma, CCAAT/enhancer-binding protein alpha, and fatty acid binding protein 4 gene expression. Collectively, our data suggest that G. elegans is a potential food source containing antiobesity and antioxidant constituents. Copyright © 2014 John Wiley & Sons, Ltd.

SIRT2 ameliorates lipopolysaccharide-induced inflammation in macrophages

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Ae Sin; Jung, Yu Jin; Kim, Dal

2014-08-08

Highlights: • Knockout of SIRT2 attenuates lipopolysaccharide-induced iNOS expression. • Lipopolysaccharide-induced NO production is decreased in SIRT2 KO macrophage. • SIRT2 deficiency suppresses lipopolysaccharide-induced ROS production in macrophage. • M1-macrophage related factors are decreased in SIRT2 deficient cells. • SIRT2 deficiency decreases lipopolysaccharide-induced activation of NFκB. - Abstract: Introduction: SIRT2 is a NAD(+)-dependent deacetylases and associated with numerous processes such as infection, carcinogenesis, DNA damage and cell cycle regulation. However, the role of SIRT2 in inflammatory process in macrophage remains unclear. Materials and methods: In the present study, we have evaluated the regulatory effects of SIRT2 in lipopolysaccharide (LPS)-stimulated macrophagesmore » isolated from SIRT2 knockout (KO) and wild type (WT) mice or Raw264.7 macrophage cells. As inflammatory parameters, expression of inducible nitric oxide synthase (iNOS), the productions of nitric oxide, reactive oxygen species (ROS) and M1-macrophage-related factors were evaluated. We also examined the effects of SIRT2 on activation of nuclear factor-kappaB (NFκB) signaling. Results: SIRT2 deficiency inhibits LPS-induced iNOS mRNA and protein expression in bone marrow derived macrophages. SIRT2-siRNA transfection also suppressed LPS-induced iNOS expression in Raw264.7 macrophage cells. Bone marrow derived macrophages isolated from SIRT2 KO mice produced lower nitric oxide and expressed lower levels of M1-macrophage related markers including iNOS and CD86 in response to LPS than WT mice. Decrease of SIRT2 reduced the LPS-induced reactive oxygen species production. Deficiency of SIRT2 resulted in inhibition of NFκB activation through reducing the phosphorylation and degradation of IκBα. The phosphorylation and nuclear translocation of p65 was significantly decreased in SIRT2-deficient macrophages after LPS stimulation. Discussion: Our data suggested that deficiency of SIRT2 ameliorates iNOS, NO expression and reactive oxygen species production with suppressing LPS-induced activation of NFκB in macrophages.« less

NADPH Oxidase Plays a Role on Ethanol-Induced Hypertension and Reactive Oxygen Species Generation in the Vasculature.

PubMed

Marchi, Katia Colombo; Ceron, Carla Speroni; Muniz, Jaqueline J; De Martinis, Bruno S; Tanus-Santos, José E; Tirapelli, Carlos Renato

2016-09-01

Investigate the role of NADPH oxidase on ethanol-induced hypertension and vascular oxidative stress. Male Wistar rats were treated with ethanol (20% v/v). Apocynin (10 mg/kg/day, i.p.) prevented ethanol-induced hypertension. The increased contractility of endothelium-intact and endothelium-denuded aortic rings from ethanol-treated rats to phenylephrine was prevented by apocynin. Ethanol consumption increased superoxide anion (O2 (-)) generation and lipid peroxidation and apocynin prevented these responses. The decrease on plasma and vascular nitrate/nitrite (NOx) levels induced by ethanol was not prevented by apocynin. Treatment with ethanol did not affect aortic levels of hydrogen peroxide (H2O2) or reduced glutathione (GSH). Ethanol did not alter the activities of xanthine oxidase (XO), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Ethanol increased the expression of Nox1, PKCδ, nNOS, SAPK/JNK and SOD2 in the rat aorta and apocynin prevented these responses. No difference on aortic expression of Nox2, Nox4, p47phox, Nox organizer 1 (Noxo1), eNOS and iNOS was detected after treatment with ethanol. Ethanol treatment did not alter the phosphorylation of SAPK/JNK, p38MAPK, c-Src, Rac1 or PKCδ. The major new finding of our study is that the increased vascular generation of reactive oxygen species (ROS) induced by ethanol is related to increased vascular Nox1/NADPH oxidase expression. This mechanism is involved in vascular dysfunction and hypertension induced by ethanol. Additionally, we conclude that ethanol consumption induces the expression of different proteins that regulate vascular contraction and growth and that NADPH oxidase-derived ROS play a role in such response. The key findings of our study are that ethanol-induced hypertension is mediated by NADPH oxidase. Moreover, increased vascular Nox1 expression is related to the generation of reactive oxygen species (ROS) by ethanol. Finally, ROS induced by ethanol increase the expression of the regulatory vascular proteins. © The Author 2016. Medical Council on Alcohol and Oxford University Press. All rights reserved.

Hypoxia promotes Mycobacterium tuberculosis-specific up-regulation of granulysin in human T cells.

PubMed

Zenk, Sebastian F; Vollmer, Michael; Schercher, Esra; Kallert, Stephanie; Kubis, Jan; Stenger, Steffen

2016-06-01

Oxygen tension affects local immune responses in inflammation and infection. In tuberculosis mycobacteria avoid hypoxic areas and preferentially persist and reactivate in the oxygen-rich apex of the lung. Oxygen restriction activates antimicrobial effector mechanisms in macrophages and restricts growth of intracellular Mycobacterium tuberculosis (M.Tb). The effect of oxygen restriction on T cell-mediated antimicrobial effector mechanisms is unknown. Therefore we determined the influence of hypoxia on the expression of granulysin, an antimicrobial peptide of lymphocytes. Hypoxia increased the antigen-specific up-regulation of granulysin mRNA and protein in human CD4(+) and CD8(+) T lymphocytes. This observation was functionally relevant, because oxygen restriction supported the growth-limiting effect of antigen-specific T cells against virulent M.Tb residing in primary human macrophages. Our results provide evidence that oxygen restriction promotes the expression of granulysin and suggest that this effect-in conjunction with additional T cell-mediated immune responses-supports protection against mycobacteria. The therapeutic modulation of oxygen availability may offer a new strategy for the host-directed therapy of infectious diseases with intracellular pathogens.

Anti-skeletal muscle atrophy effect of Oenothera odorata root extract via reactive oxygen species-dependent signaling pathways in cellular and mouse model.

PubMed

Lee, Yong-Hyeon; Kim, Wan-Joong; Lee, Myung-Hun; Kim, Sun-Young; Seo, Dong-Hyun; Kim, Han-Sung; Gelinsky, Michael; Kim, Tack-Joong

2016-01-01

Skeletal muscle atrophy can be defined as a decrease of muscle volume caused by injury or lack of use. This condition is associated with reactive oxygen species (ROS), resulting in various muscular disorders. We acquired 2D and 3D images using micro-computed tomography in gastrocnemius and soleus muscles of sciatic-denervated mice. We confirmed that sciatic denervation-small animal model reduced muscle volume. However, the intraperitoneal injection of Oenothera odorata root extract (EVP) delayed muscle atrophy compared to a control group. We also investigated the mechanism of muscle atrophy's relationship with ROS. EVP suppressed expression of SOD1, and increased expression of HSP70, in both H2O2-treated C2C12 myoblasts and sciatic-denervated mice. Moreover, EVP regulated apoptotic signals, including caspase-3, Bax, Bcl-2, and ceramide. These results indicate that EVP has a positive effect on reducing the effect of ROS on muscle atrophy.

PCI-24781 (abexinostat), a novel histone deacetylase inhibitor, induces reactive oxygen species-dependent apoptosis and is synergistic with bortezomib in neuroblastoma

PubMed Central

Sholler, Giselle Saulnier; Currier, Erika A.; Dutta, Akshita; Slavik, Marni A.; Illenye, Sharon A.; Mendonca, Maria Cecilia F.; Dragon, Julie; Roberts, Stephen S.; Bond, Jeffrey P.

2014-01-01

In this study, we investigated the cytotoxic effects of a broad-spectrum histone deacetylase (HDAC) inhibitor, PCI-24781, alone and in combination with the proteasome inhibitor bortezomib in neuroblastoma cell lines. The combination was shown to induce synergistic cytotoxity involving the formation of reactive oxygen species. The cleavage of caspase-3 and PARP, as determined by western blotting, indicated that cell death was primarily due to apoptosis. Xenograft mouse models indicated increased survival among animals treated with this combination. The Notch signaling pathway and MYCN gene expression were quantified by reverse transcription-polymerase chain reaction (PCR) in cells treated with PCI-24781 and bortezomib, alone and in combination. Notch pathway expression increased in response to an HDAC inhibitor. NFKB1 and MYCN were both significantly down regulated. Our results suggest that PCI-24781 and bortezomib are synergistic in neuroblastoma cell lines and may be a new therapeutic strategy for this disease. PMID:25520806

Protein expression and oxygen consumption rate of early postmortem mitochondria relate to meat tenderness.

PubMed

Grabež, V; Kathri, M; Phung, V; Moe, K M; Slinde, E; Skaugen, M; Saarem, K; Egelandsdal, B

2015-04-01

Oxygen consumption rate (OCR) of muscle fibers from bovine semimembranosus muscle of 41 animals was investigated 3 to 4 h and 3 wk postmortem. Significant relations (P < 0.05) were found between OCR measurements and Warner-Bratzler shear force measurement. Muscles with high mitochondrial OCR after 3 to 4 h and low nonmitochondrial oxygen consumption gave more tender meat. Tender (22.92 ± 2.2 N/cm2) and tough (72.98 ± 7.2 N/cm2) meat samples (4 samples each), separated based on their OCR measurements, were selected for proteomic studies using mitochondria isolated approximately 2.5 h postmortem. Twenty-six differently expressed proteins (P < 0.05) were identified in tender meat and 19 in tough meat. In tender meat, the more prevalent antioxidant and chaperon enzymes may reduce reactive oxygen species and prolong oxygen removal by the electron transport system (ETS). Glycolytic, Krebs cycle, and ETS enzymes were also more abundant in tender meat

Alleviation of Rosup-induced oxidative stress in porcine granulosa cells by anthocyanins from red-fleshed apples.

PubMed

Xiang, Ya; Lai, Fangnong; He, Guifang; Li, Yapeng; Yang, Leilei; Shen, Wei; Huo, Heqiang; Zhu, Jun; Dai, Hongyi; Zhang, Yugang

2017-01-01

Anthocyanins are the polyphenolic phytochemicals which have been shown to scavenge free radicals. In this study, we investigated the effects of anthocyanins extracted from red-fleshed apples (Malus sieversii) on reducing oxidative damage by Rosup in porcine granulosa cells (GCs) by measuring intracellular reactive oxygen species (ROS), content of glutathione (GSH), activities of superoxide dismutase (SOD1), catalase (CAT) and glutathione peroxidase (GPX1) and the gene expression of SOD1, CAT, GPX1. Apoptosis was determined with TdT-mediated dUTP-biotin nick end labeling (TUNEL) and apoptosis-related proteins were quantified with Western blotting. The results indicate that Rosup increases oxidative stress by inducing reactive oxygen species production in porcine GCs and the oxidative stress could be reduced by anthocyanins. The gene expression of SOD1, CAT, GPX1 and the activities of these enzymes were increased when GCs were treated with anthocyanins and Rosup for 6 hours. Anthocyanins inhibit Rosup-induced apoptosis by increasing expression of antiapoptotic protein Bcl-2 and suppressing the expression of pro-apoptotic protein Bax. Collectively, anthocyanins from red-fleshed apples reduce oxidative stress and inhibit apoptosis in porcine GCs in vitro. This approach indicates that antioxidants might be developed from red-fleshed apples.

Alleviation of Rosup-induced oxidative stress in porcine granulosa cells by anthocyanins from red-fleshed apples

PubMed Central

He, Guifang; Li, Yapeng; Yang, Leilei; Shen, Wei; Huo, Heqiang; Zhu, Jun; Dai, Hongyi

2017-01-01

Anthocyanins are the polyphenolic phytochemicals which have been shown to scavenge free radicals. In this study, we investigated the effects of anthocyanins extracted from red-fleshed apples (Malus sieversii) on reducing oxidative damage by Rosup in porcine granulosa cells (GCs) by measuring intracellular reactive oxygen species (ROS), content of glutathione (GSH), activities of superoxide dismutase (SOD1), catalase (CAT) and glutathione peroxidase (GPX1) and the gene expression of SOD1, CAT, GPX1. Apoptosis was determined with TdT-mediated dUTP-biotin nick end labeling (TUNEL) and apoptosis-related proteins were quantified with Western blotting. The results indicate that Rosup increases oxidative stress by inducing reactive oxygen species production in porcine GCs and the oxidative stress could be reduced by anthocyanins. The gene expression of SOD1, CAT, GPX1 and the activities of these enzymes were increased when GCs were treated with anthocyanins and Rosup for 6 hours. Anthocyanins inhibit Rosup-induced apoptosis by increasing expression of antiapoptotic protein Bcl-2 and suppressing the expression of pro-apoptotic protein Bax. Collectively, anthocyanins from red-fleshed apples reduce oxidative stress and inhibit apoptosis in porcine GCs in vitro. This approach indicates that antioxidants might be developed from red-fleshed apples. PMID:28850606

NADPH oxidase 2-derived reactive oxygen species signal contributes to bradykinin-induced matrix metalloproteinase-9 expression and cell migration in brain astrocytes

PubMed Central

2012-01-01

Background Matrix metalloproteinase-9 (MMP-9) plays a crucial role in pathological processes of brain inflammation, injury, and neurodegeneration. Moreover, bradykinin (BK) induces the expression of several inflammatory proteins in brain astrocytes. Recent studies have suggested that increased oxidative stress is implicated in the brain inflammation and injury. However, whether BK induced MMP-9 expression mediated through oxidative stress remains virtually unknown. Herein we investigated the role of redox signals in BK-induced MMP-9 expression in rat brain astrocytes (RBA-1 cells). Results In the study, we first demonstrated that reactive oxygen species (ROS) plays a crucial role in BK-induced MMP-9 expression in cultured brain astrocytes (in vitro) and animal brain tissue (in vivo) models. Next, BK-induced MMP-9 expression is mediated through a Ca2+-mediated PKC-α linking to p47phox/NADPH oxidase 2 (Nox2)/ROS signaling pathway. Nox2-dependent ROS generation led to activation and up-regulation of the downstream transcriptional factor AP-1 (i.e. c-Fos and c-Jun), which bound to MMP-9 promoter region, and thereby turned on transcription of MMP-9 gene. Functionally, BK-induced MMP-9 expression enhanced astrocytic migration. Conclusions These results demonstrated that in RBA-1 cells, activation of AP-1 (c-Fos/c-Jun) by the PKC-α-mediated Nox2/ROS signals is essential for up-regulation of MMP-9 and cell migration enhanced by BK. PMID:23176293

Incorporating Geochemical And Microbial Kinetics In Reactive Transport Models For Generation Of Acid Rock Drainage

NASA Astrophysics Data System (ADS)

Andre, B. J.; Rajaram, H.; Silverstein, J.

2010-12-01

Acid mine drainage, AMD, results from the oxidation of metal sulfide minerals (e.g. pyrite), producing ferrous iron and sulfuric acid. Acidophilic autotrophic bacteria such as Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans obtain energy by oxidizing ferrous iron back to ferric iron, using oxygen as the electron acceptor. Most existing models of AMD do not account for microbial kinetics or iron geochemistry rigorously. Instead they assume that oxygen limitation controls pyrite oxidation and thus focus on oxygen transport. These models have been successfully used for simulating conditions where oxygen availability is a limiting factor (e.g. source prevention by capping), but have not been shown to effectively model acid generation and effluent chemistry under a wider range of conditions. The key reactions, oxidation of pyrite and oxidation of ferrous iron, are both slow kinetic processes. Despite being extensively studied for the last thirty years, there is still not a consensus in the literature about the basic mechanisms, limiting factors or rate expressions for microbially enhanced oxidation of metal sulfides. An indirect leaching mechanism (chemical oxidation of pyrite by ferric iron to produce ferrous iron, with regeneration of ferric iron by microbial oxidation of ferrous iron) is used as the foundation of a conceptual model for microbially enhanced oxidation of pyrite. Using literature data, a rate expression for microbial consumption of ferrous iron is developed that accounts for oxygen, ferrous iron and pH limitation. Reaction rate expressions for oxidation of pyrite and chemical oxidation of ferrous iron are selected from the literature. A completely mixed stirred tank reactor (CSTR) model is implemented coupling the kinetic rate expressions, speciation calculations and flow. The model simulates generation of AMD and effluent chemistry that qualitatively agrees with column reactor and single rock experiments. A one dimensional reaction diffusion model at the scale of a single rock is developed incorporating the proposed kinetic rate expressions. Simulations of initiation, washout and AMD flows are discussed to gain a better understanding of the role of porosity, effective diffusivity and reactive surface area in generating AMD. Simulations indicate that flow boundary conditions control generation of acid rock drainage as porosity increases.

trans-Resveratrol Protects Ischemic PC12 Cells by Inhibiting the Hypoxia Associated Transcription Factors and Increasing the Levels of Antioxidant Defense Enzymes

PubMed Central

2012-01-01

An in vitro model of ischemic cerebral stroke [oxygen-glucose deprivation (OGD) for 6 h followed by 24 h reoxygenation (R)] with PC12 cells increases Ca2+ influx by upregulating native L-type Ca2+ channels and reactive oxygen species (ROS) generation. This reactive oxygen species generation and increase in intracellular Ca2+ triggers the expression of hypoxic homeostasis transcription factors such as hypoxia induced factor-1 alpha (HIF-1α), Cav-beta 3 (Cav β3), signal transducer and activator of transcription 3 (STAT3), heat shock protein 27 (hsp-27), and cationic channel transient receptor potential melastatin 7 (TRPM7). OGD insulted PC12 cells were subjected to biologically safe doses (5, 10, and 25 μM) of trans-resveratrol in three different treatment groups: 24 h prior to OGD (pre-treatment); 24 h post OGD (post-treatment); and from 24 h before OGD to end of reoxygenation period (whole-treatment). Here, we demonstrated that OGD-R-induced neuronal injury/death is by reactive oxygen species generation, increase in intracellular calcium levels, and decrease in antioxidant defense enzymes. trans-Resveratrol increases the viability of OGD-R insulted PC12 cells, which was assessed by using MTT, NRU, and LDH release assay. In addition, trans-resveratrol significantly decreases reactive oxygen species generation, intracellular Ca2+ levels, and hypoxia associated transcription factors and also increases the level of antioxidant defense enzymes. Our data shows that the whole-treatment group of trans-resveratrol is most efficient in decreasing hypoxia induced cell death through its antioxidant properties. PMID:23421680

Release of oxygen radicals by articular chondrocytes: a study of luminol-dependent chemiluminescence and hydrogen peroxide secretion.

PubMed

Rathakrishnan, C; Tiku, K; Raghavan, A; Tiku, M L

1992-10-01

We previously established that normal articular chondrocytes, like macrophages, express class II major histocompatibility antigens, present antigen, and induce mixed and autologous lymphocyte stimulation. In a recent study using the trapped indicator 2',7'-dichlorofluorescein diacetate, we were able to measure levels of intracellular hydrogen peroxide within normal articular chondrocytes (J Immunol 245:690-696, 1990). In the present study, we utilized the technique of chemiluminescence and the biochemical method of quantitating hydrogen peroxide release to measure the production of reactive oxygen intermediates by articular chondrocytes. Chondrocytes, in suspension or adherent to coverslips, showed luminol-dependent chemiluminescence that was dependent on the number and viability of cells. There was a dose-dependent increase in chemiluminescence in response to soluble stimuli, such as phorbol myristate acetate (PMA), concanavalin A (ConA), and f-Met-Leu-Phe (FMLP). Azide inhibited chemiluminescence, suggesting that the light emission in chondrocytes is myeloperoxidase dependent. The antioxidant, catalase, inhibited chemiluminescence but superoxide dismutase had no effect, suggesting that luminol-dependent chemiluminescence in chondrocytes mostly measured hydrogen peroxide. Chemiluminescence was also observed in fragments of live cartilage tissue, indicating that chondrocytes that are cartilage matrix bound can generate the respiratory burst response. Using the scopoletin oxidation assay, we confirmed the release of increasing amounts of hydrogen peroxide by chondrocytes exposed to interleukin-1, rabbit interferon, and tumor necrosis factor alpha. Tumor necrosis factor alpha had both priming and enhancing effects on reactive oxygen intermediate production by chondrocytes. Reactive oxygen intermediates have been shown to play a significant role in matrix degradation. We suggest that reactive oxygen intermediates produced by chondrocytes play an important role in the degradation of matrix in arthritis.

Chemical Looping Combustion Reactions and Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sarofim, Adel; Lighty, JoAnn; Smith, Philip

2014-03-01

Chemical Looping Combustion (CLC) is one promising fuel-combustion technology, which can facilitate economic CO{sub 2} capture in coal-fired power plants. It employs the oxidation/reduction characteristics of a metal, or oxygen carrier, and its oxide, the oxidizing gas (typically air) and the fuel source may be kept separate. This topical report discusses the results of four complementary efforts: (5.1) the development of process and economic models to optimize important design considerations, such as oxygen carrier circulation rate, temperature, residence time; (5.2) the development of high-performance simulation capabilities for fluidized beds and the collection, parameter identification, and preliminary verification/uncertainty quantification; (5.3) themore » exploration of operating characteristics in the laboratoryscale bubbling bed reactor, with a focus on the oxygen carrier performance, including reactivity, oxygen carrying capacity, attrition resistance, resistance to deactivation, cost and availability; and (5.4) the identification of kinetic data for copper-based oxygen carriers as well as the development and analysis of supported copper oxygen carrier material. Subtask 5.1 focused on the development of kinetic expressions for the Chemical Looping with Oxygen Uncoupling (CLOU) process and validating them with reported literature data. The kinetic expressions were incorporated into a process model for determination of reactor size and oxygen carrier circulation for the CLOU process using ASPEN PLUS. An ASPEN PLUS process model was also developed using literature data for the CLC process employing an iron-based oxygen carrier, and the results of the process model have been utilized to perform a relative economic comparison. In Subtask 5.2, the investigators studied the trade-off between modeling approaches and available simulations tools. They quantified uncertainty in the high-performance computing (HPC) simulation tools for CLC bed applications. Furthermore, they performed a sensitivity analysis for velocity, height and polydispersity and compared results against literature data for experimental studies of CLC beds with no reaction. Finally, they present an optimization space using simple non-reactive configurations. In Subtask 5.3, through a series of experimental studies, behavior of a variety of oxygen carriers with different loadings and manufacturing techniques was evaluated under both oxidizing and reducing conditions. The influences of temperature, degree of carrier conversion and thermodynamic driving force resulting from the difference between equilibrium and system O{sub 2} partial pressures were evaluated through several experimental campaigns, and generalized models accounting for these influences were developed to describe oxidation and oxygen release. Conversion of three solid fuels with widely ranging reactivities was studied in a small fluidized bed system, and all but the least reactive fuel (petcoke) were rapidly converted by oxygen liberated from the CLOU carrier. Attrition propensity of a variety of carriers was also studied, and the carriers produced by freeze granulation or impregnation of preformed substrates displayed the lowest rates of attrition. Subtask 5.4 focused on gathering kinetic data for a copper-based oxygen carrier to assist with modeling of a functioning chemical looping reactor. The kinetics team was also responsible for the development and analysis of supported copper oxygen carrier material.« less

Oxidative stress involvement in Physalis angulata-induced apoptosis in human oral cancer cells.

PubMed

Lee, H-Z; Liu, W-Z; Hsieh, W-T; Tang, F-Y; Chung, J-G; Leung, Henry W-C

2009-03-01

In this report, we investigated the role of oxidative stress in Physalis angulata-induced apoptosis of human oral cancer cells. P. angulata-induced apoptosis was characterized by nuclear morphological changes, membrane blebbing and activation of caspase-9. Exposure of HSC-3 cells to P. angulata caused production of reactive oxygen species and up-regulation of oxidative stress markers heme oxygenase-1 (HO-1), superoxide dismutase (SOD), heat shock protein 70 (HSP70) and caspase-4. Down-regulation of HO-1, SOD and HSP70 proteins expression by attenuation of oxidative stress, pretreatment with glutathione or N-acetylcysteine, significantly decreased P. angulata-triggered cell death. The present study also demonstrated that the mitochondria and the endoplasmic reticulum are the targets of P. angulata in HSC-3 cells. Our results revealed that: (1) reactive oxygen species may play a dominant role in this process, (2) P. angulata induces oxidative stress in HSC-3 cells, (3) P. angulata-initiated apoptosis is caused through oxidative stress-dependent induction of heme oxygenase-1, Cu/Zn SOD and HSP70 proteins expression and (4) antioxidants inhibited P. angulata-induced cell death through inhibition of the proteins expression of HO-1, Cu/Zn SOD and HSP70.

Sulforaphane inhibits TGF-β-induced epithelial-mesenchymal transition of hepatocellular carcinoma cells via the reactive oxygen species-dependent pathway.

PubMed

Wu, Jinsheng; Han, Jingli; Hou, Benxin; Deng, Chengwei; Wu, Huanliang; Shen, Liangfang

2016-05-01

Sulforaphane is recognized as a safe antitumor agent derived from various cruciferous vegetables, including broccoli. It has been demonstrated that sulforaphase is a potent antitumor agent in diverse cancers. However, its effect on hepatocellular carcinoma remains largely unknown. Here, we show that sulforaphane inhibits TGF-β-induced epithelial-mesenchymal transition of hepatocellular carcinoma cell via the reactive oxygen species-dependent pathway. We found sulforaphane inhibited hepatocellular carcinoma cell proliferation in a dose- and time-dependent manner. Sulforaphane induced G0/G1 phase cell cycle arrest and promoted cell apoptosis. A set of experiments showed that sulforaphase inhibited hepatocellular carcinoma cell migration and invasion, inhibited the formation of fibroblast like mesenchymal cells and the expression of Vimentin, but increased the expression of E-cadherin, suggesting sulforaphane suppresses epithelial-mesenchymal transition (EMT) process. Cotreatment with N-acetyl-L-cysteine inhibited sulforaphane-inhibited invasion and upregulation of E-cadherin and almost completely abolished the sulforaphane-induced expression of Vimentin. The effect of sulforaphane on the growth of hepatocellular carcinoma cells was confirmed by a xenograft tumor growth model. All our finding indicated that sulforaphane is a promising and safe strategy for treating hepatocellular carcinoma.

RelA-Mediated BECN1 Expression Is Required for Reactive Oxygen Species-Induced Autophagy in Oral Cancer Cells Exposed to Low-Power Laser Irradiation

PubMed Central

Wu, Chieh-Shan; Chen, Chien-Hsun; Wu, Sam; Chang, Hsueh-Wei; Kuo, Soong-Yu; Fu, Earl; Liu, Pei-Feng; Hsieh, Yao-Dung

2016-01-01

Low-power laser irradiation (LPLI) is a non-invasive and safe method for cancer treatment that alters a variety of physiological processes in the cells. Autophagy can play either a cytoprotective role or a detrimental role in cancer cells exposed to stress. The detailed mechanisms of autophagy and its role on cytotoxicity in oral cancer cells exposed to LPLI remain unclear. In this study, we showed that LPLI at 810 nm with energy density 60 J/cm2 increased the number of microtubule associated protein 1 light chain 3 (MAP1LC3) puncta and increased autophagic flux in oral cancer cells. Moreover, reactive oxygen species (ROS) production was induced, which increased RelA transcriptional activity and beclin 1 (BECN1) expression in oral cancer cells irradiated with LPLI. Furthermore, ROS scavenger or knockdown of RelA diminished LPLI-induced BECN1 expression and MAP1LC3-II conversion. In addition, pharmacological and genetic ablation of autophagy significantly enhanced the effects of LPLI-induced apoptosis in oral cancer cells. These results suggest that autophagy may be a resistant mechanism for LPLI-induced apoptosis in oral cancer cells. PMID:27632526

Metal ions induced heat shock protein response by elevating superoxide anion level in HeLa cells transformed by HSE-SEAP reporter gene.

PubMed

Yu, Zhanjiang; Yang, Xiaoda; Wang, Kui

2006-06-01

The aim of this work is to define the relationship between heat shock protein (HSP) and reactive oxygen species (ROS) in the cells exposed to different concentrations of metal ions, and to evaluate a new method for tracing the dynamic levels of cellular reactive oxygen species using a HSE-SEAP reporter gene. The expression of heat shock protein was measured using a secreted alkaline phosphatase (SEAP) reporter gene transformed into HeLa cell strain, the levels of superoxide anion (O(2)(-)) and hydrogen peroxide (H(2)O(2)) were determined by NBT reduction assay and DCFH staining flow cytometry (FCM), respectively. The experimental results demonstrated that the expression of heat shock protein induced by metal ions was linearly related to the cellular superoxide anion level before cytotoxic effects were observed, but not related to the cellular hydrogen peroxide level. The experimental results suggested that metal ions might induce heat shock protein by elevating cellular superoxide anion level, and thus the expression of heat shock protein indicated by the HSE-SEAP reporter gene can be an effective model for monitoring the dynamic level of superoxide anion and early metal-induced oxidative stress/cytotoxicity.

ISA virus regulates the generation of reactive oxygen species and p47phox expression in a p38 MAPK-dependent manner in Salmo salar.

PubMed

Olavarría, Víctor H; Valdivia, Sharin; Salas, Boris; Villalba, Melina; Sandoval, Rodrigo; Oliva, Harold; Valdebenito, Samuel; Yañez, Alejandro

2015-02-01

Several viruses, including Orthomyxovirus, utilize cellular reactive oxygen species (ROS) for viral genomic replication and survival within host cells. However, the role of ROS in early events of viral entry and signal induction has not been elucidated. Here, we show that ISA virus (ISAV) induces ROS production very early during infection of CHSE-214 and SHK-1Ycells, and that production is sustained over the observed 24h post-infection. The mitogen-activated protein kinase (MAPK) family is responsible for important signaling pathways. In this study, we report that ISAV activates ERK and p38 in Salmo salar. In salmonid macrophages, while ERK was required for SOD, GLURED, p47phox expression, p38 regulated the ROS production by the NADPH oxidase complex activation. These results, together with the presence of several consensus target motifs for p38 MAPK in the promoter of the S. salar p47phox gene, suggest that p38 MAPK regulates p47phox gene expression in fish through the activation of this key transcription factor. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of different concentrations of oxygen on expression of sigma 1 receptor and superoxide dismutases in human colon adenocarcinoma cell lines.

PubMed

Skrzycki, Michał; Czeczot, Hanna; Mielczarek-Puta, Magdalena; Otto-Ślusarczyk, Dagmara; Graboń, Wojciech

2017-06-01

Tumor cells due to distance from capillary vessels exist in different oxygenation conditions (anoxia, hypoxia, normoxia). Changes in cell oxygenation lead to reactive oxygen species production and oxidative stress. Sigma 1 receptor (Sig1R) is postulated to be stress responding agent and superoxide dismutases (SOD1 and SOD2) are key antioxidant enzymes. It is possible that they participate in tumor cells adaptation to different concentrations of oxygen. Evaluation of Sig1R, SOD1, and SOD2 expression in different concentrations of oxygen (1%, 10%, 21%) in colon adenocarcinoma cell lines. SW480 (primary adenocarcinoma) and SW620 (metastatic) cell lines were cultured in standard conditions in Dulbecco's modified Eagle's medium for 5 days, and next cultured in Hypoxic Chamber in 1% O 2 , 10% O 2 , 21% O 2 . Number of living cells was determined by trypan blue assay. Level of mRNA for Sig1R, SOD1, and SOD2 was determined by standard PCR method. Statistical analysis was conducted using Statistica 10.1 software. We observed significant changes in expression of Sig1R, SOD1, SOD2 due to different oxygen concentrations. ANOVA analysis revealed significant interactions between studied parameters mainly in hypoxia conditions in SW480 cells and between Sig1R and SOD2 in SW620 cells. It also showed that changes in expression of studied proteins depend significantly on type of the cell line. Changes of Sig1R and SOD2 expression point to mitochondria as main organelle responsible for survival of tumor cells exposed to hypoxia or oxidative stress. Studied proteins are involved in intracellular response to stress related with different concentrations of oxygen.

Low Oxygen Tension Enhances Expression of Myogenic Genes When Human Myoblasts Are Activated from G0 Arrest

PubMed Central

Sellathurai, Jeeva; Nielsen, Joachim; Hejbøl, Eva Kildall; Jørgensen, Louise Helskov; Dhawan, Jyotsna; Nielsen, Michael Friberg Bruun; Schrøder, Henrik Daa

2016-01-01

Objectives Most cell culture studies have been performed at atmospheric oxygen tension of 21%, however the physiological oxygen tension is much lower and is a factor that may affect skeletal muscle myoblasts. In this study we have compared activation of G0 arrested myoblasts in 21% O2 and in 1% O2 in order to see how oxygen tension affects activation and proliferation of human myoblasts. Materials and Methods Human myoblasts were isolated from skeletal muscle tissue and G0 arrested in vitro followed by reactivation at 21% O2 and 1% O2. The effect was assesses by Real-time RT-PCR, immunocytochemistry and western blot. Results and Conclusions We found an increase in proliferation rate of myoblasts when activated at a low oxygen tension (1% O2) compared to 21% O2. In addition, the gene expression studies showed up regulation of the myogenesis related genes PAX3, PAX7, MYOD, MYOG (myogenin), MET, NCAM, DES (desmin), MEF2A, MEF2C and CDH15 (M-cadherin), however, the fraction of DES and MYOD positive cells was not increased by low oxygen tension, indicating that 1% O2 may not have a functional effect on the myogenic response. Furthermore, the expression of genes involved in the TGFβ, Notch and Wnt signaling pathways were also up regulated in low oxygen tension. The differences in gene expression were most pronounced at day one after activation from G0-arrest, thus the initial activation of myoblasts seemed most sensitive to changes in oxygen tension. Protein expression of HES1 and β-catenin indicated that notch signaling may be induced in 21% O2, while the canonical Wnt signaling may be induced in 1% O2 during activation and proliferation of myoblasts. PMID:27442119

Reactive oxygen species promote ovarian cancer progression via the HIF-1α/LOX/E-cadherin pathway.

PubMed

Wang, Yu; Ma, Jun; Shen, Haoran; Wang, Chengjie; Sun, Yueping; Howell, Stephen B; Lin, Xinjian

2014-11-01

Reactive oxygen species (ROS) can drive the de‑differentiation of tumor cells leading to the process of epithelial-to-mesenchymal transition (EMT) to enhance invasion and metastasis. The invasive and metastatic phenotype of malignant cells is often linked to loss of E-cadherin expression, a hallmark of EMT. Recent studies have demonstrated that hypoxic exposure causes HIF-1-dependent repression of E-cadherin. However, the mechanism by which ROS and/or HIF suppresses E-cadherin expression remains less clear. In the present study, we found that ROS accumulation in ovarian carcinoma cells upregulated HIF-1α expression and subsequent transcriptional induction of lysyl oxidase (LOX) which repressed E-cadherin. Loss of E-cadherin facilitated ovarian cancer (OC) cell migration in vitro and promoted tumor growth in vivo. E-cadherin immunoreactivity correlated with International Federation of Gynecology and Obstetrics (FIGO) stage, tumor differentiation and metastasis. Negative E-cadherin expression along with FIGO stage, tumor differentiation and metastasis significantly predicted for a lower 5-year survival rate. These findings suggest that ROS play an important role in the initiation of metastatic growth of OC cells and support a molecular pathway from ROS to aggressive transformation which involves upregulation of HIF-1α and its downstream target LOX to suppress E-cadherin expression leading to an increase in cell motility and invasiveness.

Cotesia vestalis parasitization suppresses expression of a Plutella xylostella thioredoxin

USDA-ARS?s Scientific Manuscript database

Thioredoxins (Trxs) are a family of small, highly conserved and ubiquitous proteins involved in protecting organisms against toxic reactive oxygen species (ROS). In this study, a typical thioredoxin gene, PxTrx, was isolated from Plutella xylostella. The full-length cDNA sequence is composed of 959 ...

ROS/redox signaling regulates bone turnover in an age-specific manner in female mice

USDA-ARS?s Scientific Manuscript database

In bone, oxidant signaling through NADPH oxidase (NOX)-derived reactive oxygen species (ROS) superoxide and/or hydrogen peroxide appears to be an important stimulus for osteoclast differentiation and activity. ROS signaling has been suggested to increase RANKL mRNA and protein expression, thus enha...

Di (2-ethylhexyl) phthalate inhibits growth of mouse ovarian antral follicles through an oxidative stress pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Wei, E-mail: weiwang2@illinois.edu; Craig, Zelieann R., E-mail: zelieann@illinois.edu; Basavarajappa, Mallikarjuna S., E-mail: mbasava2@illinois.edu

2012-01-15

Di (2-ethylhexyl) phthalate (DEHP) is a plasticizer that has been shown to inhibit growth of mouse antral follicles, however, little is known about the mechanisms by which DEHP does so. Oxidative stress has been linked to follicle growth inhibition as well as phthalate-induced toxicity in non-ovarian tissues. Thus, we hypothesized that DEHP causes oxidative stress and that this leads to inhibition of the growth of antral follicles. To test this hypothesis, antral follicles isolated from CD-1 mice (age 31–35 days) were cultured with vehicle control (dimethylsulfoxide [DMSO]) or DEHP (1–100 μg/ml) ± N-acetyl cysteine (NAC, an antioxidant at 0.25–1 mM).more » During culture, follicles were measured daily. At the end of culture, follicles were collected and processed for in vitro reactive oxygen species (ROS) assays to measure the presence of free radicals or for measurement of the expression and activity of various key antioxidant enzymes: Cu/Zn superoxide dismutase (SOD1), glutathione peroxidase (GPX) and catalase (CAT). The results indicate that DEHP inhibits the growth of follicles compared to DMSO control and that NAC (0.25–1 mM) blocks the ability of DEHP to inhibit follicle growth. Furthermore, DEHP (10 μg/ml) significantly increases ROS levels and reduces the expression and activity of SOD1 compared to DMSO controls, whereas NAC (0.5 mM) rescues the effects of DEHP on ROS levels and SOD1. However, the expression and activity of GPX and CAT were not affected by DEHP treatment. Collectively, these data suggest that DEHP inhibits follicle growth by inducing production of ROS and by decreasing the expression and activity of SOD1. -- Highlights: ► DEHP inhibits growth and increases reactive oxygen species in ovarian antral follicles in vitro. ► NAC rescues the effects of DEHP on the growth and reactive oxygen species levels in follicles. ► DEHP decreases the expression and activity of Cu/Zn superoxide dismutase, which can be rescued by NAC, in antral follicles.« less

Glutathione Peroxidase-1 in Health and Disease: From Molecular Mechanisms to Therapeutic Opportunities

PubMed Central

Lubos, Edith; Loscalzo, Joseph

2011-01-01

Abstract Reactive oxygen species, such as superoxide and hydrogen peroxide, are generated in all cells by mitochondrial and enzymatic sources. Left unchecked, these reactive species can cause oxidative damage to DNA, proteins, and membrane lipids. Glutathione peroxidase-1 (GPx-1) is an intracellular antioxidant enzyme that enzymatically reduces hydrogen peroxide to water to limit its harmful effects. Certain reactive oxygen species, such as hydrogen peroxide, are also essential for growth factor-mediated signal transduction, mitochondrial function, and maintenance of normal thiol redox-balance. Thus, by limiting hydrogen peroxide accumulation, GPx-1 also modulates these processes. This review explores the molecular mechanisms involved in regulating the expression and function of GPx-1, with an emphasis on the role of GPx-1 in modulating cellular oxidant stress and redox-mediated responses. As a selenocysteine-containing enzyme, GPx-1 expression is subject to unique forms of regulation involving the trace mineral selenium and selenocysteine incorporation during translation. In addition, GPx-1 has been implicated in the development and prevention of many common and complex diseases, including cancer and cardiovascular disease. This review discusses the role of GPx-1 in these diseases and speculates on potential future therapies to harness the beneficial effects of this ubiquitous antioxidant enzyme. Antioxid. Redox Signal. 15, 1957–1997. PMID:21087145

Mapping of oxidative stress response elements of the caveolin-1 promoter.

PubMed

Bartholomew, Janine N; Galbiati, Ferruccio

2010-01-01

According to the "free radical theory" of aging, normal aging occurs as the result of tissue damages inflicted by reactive oxygen species (ROS). ROS are known to induce cellular senescence, and senescent cells are believed to contribute to organismal aging. The molecular mechanisms that mediate the cellular response to oxidants remain to be fully identified. We have shown that oxidative stress induces cellular senescence through activation of the caveolin-1 promoter and upregulation of caveolin-1 protein expression. Here, we describe how reactive oxygen species activate the caveolin-1 promoter and how the signaling may be assayed. These approaches provide insight into the functional role of caveolin-1 and potentially allow the identification of novel ROS-regulated genes that are part of the signaling machinery regulating cellular senescence/aging.

Effects of Pectic Polysaccharides Isolated from Leek on the Production of Reactive Oxygen and Nitrogen Species by Phagocytes

PubMed Central

Nikolova, Mariana; Ambrozova, Gabriela; Kratchanova, Maria; Denev, Petko; Kussovski, Veselin; Ciz, Milan

2013-01-01

Abstract The current survey investigates the effect of four polysaccharides isolated from fresh leek or alcohol insoluble substances (AIS) of leek on the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS) from phagocytes. The ability of the polysaccharides to activate serum complement was also investigated. Despite the lack of antioxidant activity, the pectic polysaccharides significantly decreased the production of ROS by human neutrophils. Polysaccharides isolated from AIS markedly activated RAW 264.7 macrophages for RNS production in a concentration-dependent manner. The Western blot analysis revealed that this effect was due to the stimulation of the inducible nitric oxide synthase protein expression of macrophages. The polysaccharides extracted from AIS with water showed the ability to fix serum complement, especially through the alternative pathway. It was found that the polysaccharide that has the highest complement-fixing effect is characterized by the highest content of uronic acids and the highest molecular weight. PMID:23905651

Transgenic expression of the dicotyledonous pattern recognition receptor EFR in rice leads to ligand-dependent activation of defense responses.

PubMed

Schwessinger, Benjamin; Bahar, Ofir; Thomas, Nicholas; Thomas, Nicolas; Holton, Nicolas; Nekrasov, Vladimir; Ruan, Deling; Canlas, Patrick E; Daudi, Arsalan; Petzold, Christopher J; Singan, Vasanth R; Kuo, Rita; Chovatia, Mansi; Daum, Christopher; Heazlewood, Joshua L; Zipfel, Cyril; Ronald, Pamela C

2015-03-01

Plant plasma membrane localized pattern recognition receptors (PRRs) detect extracellular pathogen-associated molecules. PRRs such as Arabidopsis EFR and rice XA21 are taxonomically restricted and are absent from most plant genomes. Here we show that rice plants expressing EFR or the chimeric receptor EFR::XA21, containing the EFR ectodomain and the XA21 intracellular domain, sense both Escherichia coli- and Xanthomonas oryzae pv. oryzae (Xoo)-derived elf18 peptides at sub-nanomolar concentrations. Treatment of EFR and EFR::XA21 rice leaf tissue with elf18 leads to MAP kinase activation, reactive oxygen production and defense gene expression. Although expression of EFR does not lead to robust enhanced resistance to fully virulent Xoo isolates, it does lead to quantitatively enhanced resistance to weakly virulent Xoo isolates. EFR interacts with OsSERK2 and the XA21 binding protein 24 (XB24), two key components of the rice XA21-mediated immune response. Rice-EFR plants silenced for OsSERK2, or overexpressing rice XB24 are compromised in elf18-induced reactive oxygen production and defense gene expression indicating that these proteins are also important for EFR-mediated signaling in transgenic rice. Taken together, our results demonstrate the potential feasibility of enhancing disease resistance in rice and possibly other monocotyledonous crop species by expression of dicotyledonous PRRs. Our results also suggest that Arabidopsis EFR utilizes at least a subset of the known endogenous rice XA21 signaling components.

Transgenic Expression of the Dicotyledonous Pattern Recognition Receptor EFR in Rice Leads to Ligand-Dependent Activation of Defense Responses

PubMed Central

Thomas, Nicolas; Holton, Nicolas; Nekrasov, Vladimir; Ruan, Deling; Canlas, Patrick E.; Daudi, Arsalan; Petzold, Christopher J.; Singan, Vasanth R.; Kuo, Rita; Chovatia, Mansi; Daum, Christopher; Heazlewood, Joshua L.; Zipfel, Cyril; Ronald, Pamela C.

2015-01-01

Plant plasma membrane localized pattern recognition receptors (PRRs) detect extracellular pathogen-associated molecules. PRRs such as Arabidopsis EFR and rice XA21 are taxonomically restricted and are absent from most plant genomes. Here we show that rice plants expressing EFR or the chimeric receptor EFR::XA21, containing the EFR ectodomain and the XA21 intracellular domain, sense both Escherichia coli- and Xanthomonas oryzae pv. oryzae (Xoo)-derived elf18 peptides at sub-nanomolar concentrations. Treatment of EFR and EFR::XA21 rice leaf tissue with elf18 leads to MAP kinase activation, reactive oxygen production and defense gene expression. Although expression of EFR does not lead to robust enhanced resistance to fully virulent Xoo isolates, it does lead to quantitatively enhanced resistance to weakly virulent Xoo isolates. EFR interacts with OsSERK2 and the XA21 binding protein 24 (XB24), two key components of the rice XA21-mediated immune response. Rice-EFR plants silenced for OsSERK2, or overexpressing rice XB24 are compromised in elf18-induced reactive oxygen production and defense gene expression indicating that these proteins are also important for EFR-mediated signaling in transgenic rice. Taken together, our results demonstrate the potential feasibility of enhancing disease resistance in rice and possibly other monocotyledonous crop species by expression of dicotyledonous PRRs. Our results also suggest that Arabidopsis EFR utilizes at least a subset of the known endogenous rice XA21 signaling components. PMID:25821973

H2O2 generated from mitochondrial electron transport chain in thoracic perivascular adipose tissue is crucial for modulation of vascular smooth muscle contraction.

PubMed

Costa, Rafael M; Filgueira, Fernando P; Tostes, Rita C; Carvalho, Maria Helena C; Akamine, Eliana H; Lobato, Nubia S

2016-09-01

The perivascular adipose tissue (PVAT) releases a variety of factors that affect vascular function. PVAT in the thoracic aorta shares characteristics with the brown adipose tissue, including a large amount of mitochondria. PVAT-derived factors influence both endothelial and smooth muscle function via several signaling mechanisms including the release/generation of reactive nitrogen and oxygen species. Considering the importance of reactive oxygen species (ROS) on vascular function and that mitochondria are an important source of ROS, we hypothesized that mitochondria-derived ROS in the PVAT modulates vascular reactivity. Vascular reactivity to norephinephrine (NE) was evaluated in thoracic aortic rings, with or without endothelium and/or PVAT, from male Wistar rats. Mitochondrial uncoupling, as well as hydrogen peroxide (H2O2) removal, increased the contraction in vessels surrounded by PVAT. PVAT stimulated with NE exhibited increased protein expression, determined by Western blot analysis, of manganese superoxide dismutase (Mn-SOD) and decreased protein expression of catalase. Ultimately, NE increased superoxide anion (O2(-)) generation in PVAT via increases in intracellular calcium. These results clearly demonstrate that mitochondrial electron transport chain (mETC) in PVAT contributes to modulation of aortic muscle contraction by generating higher amounts of O2(-) that is, in turn, dismutated to hydrogen peroxide, which then acts as a pivotal signaling molecule regulating vascular smooth muscle contraction. Copyright © 2015 Elsevier Inc. All rights reserved.

6-Shogaol induces cell cycle arrest and apoptosis in human hepatoma cells through pleiotropic mechanisms.

PubMed

Wu, Jung-Ju; Omar, Hany A; Lee, Ying-Ray; Teng, Yen-Ni; Chen, Pin-Shern; Chen, Yu-Chung; Huang, Hsiao-Shan; Lee, Kuan-Han; Hung, Jui-Hsiang

2015-09-05

Shogaols are a group of the active constituents of ginger that have been identified to have various biological activities. The aim of the current study was to investigate the antitumor activity of 6-shogaol in hepatocellular carcinoma (HCC) and the possible involvement of reactive oxygen species as a putative mechanism of action. HCC cell lines, HepG2 and Huh-7, were used to study the in vitro anti-cancer activity of 6-shogaol via the application of various molecular biology techniques. Results showed that 6-shogaol effectively inhibited the cell viability, caused cell cycle arrest at G2/M phase and induced apoptosis in HCC cells as indicated by MTT assay, DAPI nuclear staining, annexin V assay, cell cycle analysis, and activation of caspase-3. Western blot analysis revealed the ability of 6-shogaol to target cancer survival signaling pathways mediated by mitogen-activated protein kinase (MAPK), 5' AMP-activated protein kinase (AMPK) and Akt. In addition, 6-Shogaol induced alteration of cyclin proteins expression and caused cleavage of protein kinase C delta. Furthermore, 6-Shogaol was able to induce the production of reactive oxygen species and endoplasmic reticulum (ER) stress-associated proteins and the consequent activation of autophagy in HepG2 cells. Taken together, the current study highlights evidences that 6-shogaol induces apoptosis, modulates cyclins expression and targets cancer survival signaling pathways in HCC cell lines, at least in part, via the production of reactive oxygen species. These findings support 6-shogaol's clinical promise as a potential candidate for HCC therapy. Copyright © 2015 Elsevier B.V. All rights reserved.

Redox and Reactive Oxygen Species Regulation of Mitochondrial Cytochrome c Oxidase Biogenesis

PubMed Central

Bourens, Myriam; Fontanesi, Flavia; Soto, Iliana C.; Liu, Jingjing

2013-01-01

Abstract Significance: Cytochrome c oxidase (COX), the last enzyme of the mitochondrial respiratory chain, is the major oxygen consumer enzyme in the cell. COX biogenesis involves several redox-regulated steps. The process is highly regulated to prevent the formation of pro-oxidant intermediates. Recent Advances: Regulation of COX assembly involves several reactive oxygen species and redox-regulated steps. These include: (i) Intricate redox-controlled machineries coordinate the expression of COX isoenzymes depending on the environmental oxygen concentration. (ii) COX is a heme A-copper metalloenzyme. COX copper metallation involves the copper chaperone Cox17 and several other recently described cysteine-rich proteins, which are oxidatively folded in the mitochondrial intermembrane space. Copper transfer to COX subunits 1 and 2 requires concomitant transfer of redox power. (iii) To avoid the accumulation of reactive assembly intermediates, COX is regulated at the translational level to minimize synthesis of the heme A-containing Cox1 subunit when assembly is impaired. Critical Issues: An increasing number of regulatory pathways converge to facilitate efficient COX assembly, thus preventing oxidative stress. Future Directions: Here we will review on the redox-regulated COX biogenesis steps and will discuss their physiological relevance. Forthcoming insights into the precise regulation of mitochondrial COX biogenesis in normal and stress conditions will likely open future perspectives for understanding mitochondrial redox regulation and prevention of oxidative stress. Antioxid. Redox Signal. 19, 1940–1952. PMID:22937827

Hydrogen sulfide inhibits high glucose-induced NADPH oxidase 4 expression and matrix increase by recruiting inducible nitric oxide synthase in kidney proximal tubular epithelial cells.

PubMed

Lee, Hak Joo; Lee, Doug Yoon; Mariappan, Meenalakshmi M; Feliers, Denis; Ghosh-Choudhury, Goutam; Abboud, Hanna E; Gorin, Yves; Kasinath, Balakuntalam S

2017-04-07

High-glucose increases NADPH oxidase 4 (NOX4) expression, reactive oxygen species generation, and matrix protein synthesis by inhibiting AMP-activated protein kinase (AMPK) in renal cells. Because hydrogen sulfide (H 2 S) inhibits high glucose-induced matrix protein increase by activating AMPK in renal cells, we examined whether H 2 S inhibits high glucose-induced expression of NOX4 and matrix protein and whether H 2 S and NO pathways are integrated. High glucose increased NOX4 expression and activity at 24 h in renal proximal tubular epithelial cells, which was inhibited by sodium hydrosulfide (NaHS), a source of H 2 S. High glucose decreased AMPK phosphorylation and activity, which was restored by NaHS. Compound C, an AMPK inhibitor, prevented NaHS inhibition of high glucose-induced NOX4 expression. NaHS inhibition of high glucose-induced NOX4 expression was abrogated by N (ω)-nitro-l-arginine methyl ester, an inhibitor of NOS. NaHS unexpectedly augmented the expression of inducible NOS (iNOS) but not endothelial NOS. iNOS siRNA and 1400W, a selective iNOS inhibitor, abolished the ameliorative effects of NaHS on high glucose-induced NOX4 expression, reactive oxygen species generation, and, matrix laminin expression. Thus, H 2 S recruits iNOS to generate NO to inhibit high glucose-induced NOX4 expression, oxidative stress, and matrix protein accumulation in renal epithelial cells; the two gasotransmitters H 2 S and NO and their interaction may serve as therapeutic targets in diabetic kidney disease. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

[Hyperoxia induces reactive oxygen species production and promotes SIRT1 nucleocytoplasmic shuttling of peripheral blood mononuclear cells in premature infants in vitro].

PubMed

Yang, Xi; Dong, Wenbin; Li, Qingping; Kang, Lan; Lei, Xiaoping; Zhang, Lianyu; Lu, Youying; Zhai, Xuesong

2015-12-01

To explore the relationship between deacetylase sirtuin 1 (SIRT1) and reactive oxygen species (ROS) after oxygen therapy in the peripheral blood mononuclear cells (PBMCs) of the premature infants. According to the fraction of inspired O2 (FiO2), premature infants diagnosed with respiratory distress syndrome (RDS) (gestational age <32 weeks), were divided into three groups: low dosage oxygen group (FiO2 <300 mL/L), moderate dosage oxygen group (FiO2; 300 mL/L-400 mL/L), high dosage oxygen group (FiO2 >400 mL/L). After 48 hours of oxygen treatment, PBMCs and serum were collected from the peripheral blood. Then the intracellular ROS level was detected by MitoSOX(TM) Red labeling combined with confocal laser scanning microscopy; the malondialdehyde (MDA) content in the serum was determined by the whole spectrum spectrophotometer; the SIRT1 localization was observed by immunofluorescence staining; and the SIRT1 levels in PBMCs were examined by Western blotting. With the increase of FiO2, the ROS, MDA content and the rate of SIRT1 nucleocytoplasmic shuttling of PBMCs gradually increased and SIRT1 protein expression was significantly lowered. Hyperoxia induces ROS production in premature infants, promotes SIRT1 to cross from nucleus to cytoplasm, inhibits the resistant ability of SIRT1 to oxidative stress.

A novel amino acid and metabolomics signature in mice overexpressing muscle uncoupling protein 3

USDA-ARS?s Scientific Manuscript database

Uncoupling protein 3 (UCP3) is highly expressed in skeletal muscle and is known to lower mitochondrial reactive oxygen species and promote fatty acid oxidation; however, the global impact of UCP3 activity on skeletal muscle and whole body metabolism has not been extensively studied. We utilized unt...

Parasitization by Scleroderma guani influences expression of superoxide dismutase genes in Tenebrio molitor

USDA-ARS?s Scientific Manuscript database

Superoxide dismutase (SOD) is an antioxidant enzyme involved in detoxifying reactive oxygen species. In this study, we identified genes encoding the extracellular and intracellular copper-zinc SODs (ecCuZnSOD and icCuZnSOD) and a manganese SOD (MnSOD) in the yellow mealworm beetle, Tenebrio molitor....

Similarities and differences in global gene expression profiles between herbicide- and pathogen-induced PSII inhibition

USDA-ARS?s Scientific Manuscript database

Plant pathogens, and photosynthesis inhibiting herbicides, can both damage photosystem II (PSII), causing it to be highly sensitive to damage by light energy, and to release high levels of reactive oxygen species (ROS). This photoinhibition of PSII could possibly be the source of the strong oxidativ...

Molecular Cloning and Expression of Sequence Variants of Manganese Superoxide Dismutase Genes from Wheat

USDA-ARS?s Scientific Manuscript database

Reactive oxygen species (ROS) are very harmful to living organisms due to the potential oxidation of membrane lipids, DNA, proteins, and carbohydrates. Transformed E.coli strain QC 871, superoxide dismutase (SOD) double-mutant, with three sequence variant MnSOD1, MnSOD2, and MnSOD3 manganese supero...

Cytosolic NADP(+)-dependent isocitrate dehydrogenase protects macrophages from LPS-induced nitric oxide and reactive oxygen species.

PubMed

Maeng, Oky; Kim, Yong Chan; Shin, Han-Jae; Lee, Jie-Oh; Huh, Tae-Lin; Kang, Kwang-il; Kim, Young Sang; Paik, Sang-Gi; Lee, Hayyoung

2004-04-30

Macrophages activated by microbial lipopolysaccharides (LPS) produce bursts of nitric oxide and reactive oxygen species (ROS). Redox protection systems are essential for the survival of the macrophages since the nitric oxide and ROS can be toxic to them as well as to pathogens. Using suppression subtractive hybridization (SSH) we found that cytosolic NADP(+)-dependent isocitrate dehydrogenase (IDPc) is strongly upregulated by nitric oxide in macrophages. The levels of IDPc mRNA and of the corresponding enzymatic activity were markedly increased by treatment of RAW264.7 cells or peritoneal macrophages with LPS or SNAP (a nitric oxide donor). Over-expression of IDPc reduced intracellular peroxide levels and enhanced the survival of H2O2- and SNAP-treated RAW264.7 macrophages. IDPc is known to generate NADPH, a cellular reducing agent, via oxidative decarboxylation of isocitrate. The expression of enzymes implicated in redox protection, superoxide dismutase (SOD) and catalase, was relatively unaffected by LPS and SNAP. We propose that the induction of IDPc is one of the main self-protection mechanisms of macrophages against LPS-induced oxidative stress.

Reactive oxygen species mediates homocysteine-induced mitochondrial biogenesis in human endothelial cells: Modulation by antioxidants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perez-de-Arce, Karen; Departamento de Biologia Celular y Molecular, Facultad de Ciencias Biologicas, Pontificia Universidad Catolica de Chile, Santiago; Foncea, Rocio

2005-12-16

It has been proposed that homocysteine (Hcy)-induces endothelial dysfunction and atherosclerosis by generation of reactive oxygen species (ROS). A previous report has shown that Hcy promotes mitochondrial damage. Considering that oxidative stress can affect mitochondrial biogenesis, we hypothesized that Hcy-induced ROS in endothelial cells may lead to increased mitochondrial biogenesis. We found that Hcy-induced ROS (1.85-fold), leading to a NF-{kappa}B activation and increase the formation of 3-nitrotyrosine. Furthermore, expression of the mitochondrial biogenesis factors, nuclear respiratory factor-1 and mitochondrial transcription factor A, was significantly elevated in Hcy-treated cells. These changes were accompanied by increase in mitochondrial mass and higher mRNAmore » and protein expression of the subunit III of cytochrome c oxidase. These effects were significantly prevented by pretreatment with the antioxidants, catechin and trolox. Taken together, our results suggest that ROS is an important mediator of mitochondrial biogenesis induced by Hcy, and that modulation of oxidative stress by antioxidants may protect against the adverse vascular effects of Hcy.« less

Tretinoin-loaded lipid-core nanocapsules decrease reactive oxygen species levels and improve bovine embryonic development during in vitro oocyte maturation.

PubMed

Lucas, Caroline Gomes; Remião, Mariana Härter; Komninou, Eliza Rossi; Domingues, William Borges; Haas, Cristina; Leon, Priscila Marques Moura de; Campos, Vinicius Farias; Ourique, Aline; Guterres, Silvia S; Pohlmann, Adriana R; Basso, Andrea Cristina; Seixas, Fabiana Kömmling; Beck, Ruy Carlos Ruver; Collares, Tiago

2015-12-01

In vitro oocyte maturation (IVM) protocols can be improved by adding chemical supplements to the culture media. Tretinoin is considered an important retinoid in embryonic development and its association with lipid-core nanocapsules (TTN-LNC) represents an innovative way of improving its solubility, and chemical stability, and reducing its toxicity. The effects of supplementing IVM medium with TTN-LNC was evaluated by analyzing production of reactive oxygen species (ROS), S36-phosphorilated-p66Shc levels and caspase activity in early embryonic development, and expression of apoptosis and pluripotency genes in blastocysts. The lowest concentration tested (0.25μM) of TTN-LNC generated higher blastocyst rate, lower ROS production and S36-p66Shc amount. Additionally, expression of BAX and SHC1 were lower in both non-encapsulated tretinoin (TTN) and TTN-LNC-treated groups. Nanoencapsulation allowed the use of smaller concentrations of tretinoin to supplement IVM medium thus reducing toxic effects related with its use, decreasing ROS levels and apoptose frequency, and improving the blastocyst rates. Copyright © 2015 Elsevier Inc. All rights reserved.

Anti-Neutrophil Cytoplasmic Antibodies Stimulate Release of Neutrophil Microparticles

PubMed Central

Eleftheriou, Despina; Hussain, Abdullah A.K.; Price-Kuehne, Fiona E.; Savage, Caroline O.; Jayne, David; Little, Mark A.; Salama, Alan D.; Klein, Nigel J.; Brogan, Paul A.

2012-01-01

The mechanisms by which anti-neutrophil cytoplasmic antibodies (ANCAs) may contribute to the pathogenesis of ANCA-associated vasculitis are not well understood. In this study, both polyclonal ANCAs isolated from patients and chimeric proteinase 3–ANCA induced the release of neutrophil microparticles from primed neutrophils. These microparticles expressed a variety of markers, including the ANCA autoantigens proteinase 3 and myeloperoxidase. They bound endothelial cells via a CD18-mediated mechanism and induced an increase in endothelial intercellular adhesion molecule-1 expression, production of endothelial reactive oxygen species, and release of endothelial IL-6 and IL-8. Removal of the neutrophil microparticles by filtration or inhibition of reactive oxygen species production with antioxidants abolished microparticle-mediated endothelial activation. In addition, these microparticles promoted the generation of thrombin. In vivo, we detected more neutrophil microparticles in the plasma of children with ANCA-associated vasculitis compared with that in healthy controls or those with inactive vasculitis. Taken together, these results support a role for neutrophil microparticles in the pathogenesis of ANCA-associated vasculitis, potentially providing a target for future therapeutics. PMID:22052057

Mitochondrial electron transport chain identified as a novel molecular target of SPIO nanoparticles mediated cancer-specific cytotoxicity.

PubMed

He, Chengyong; Jiang, Shengwei; Jin, Haijing; Chen, Shuzhen; Lin, Gan; Yao, Huan; Wang, Xiaoyong; Mi, Peng; Ji, Zhiliang; Lin, Yuchun; Lin, Zhongning; Liu, Gang

2016-03-01

Superparamagnetic iron oxide nanoparticles (SPIONs) are highly cytotoxic and target cancer cells with high specificity; however, the mechanism by which SPIONs induce cancer cell-specific cytotoxicity remains unclear. Herein, the molecular mechanism of SPION-induced cancer cell-specific cytotoxicity to cancer cells is clarified through DNA microarray and bioinformatics analyses. SPIONs can interference with the mitochondrial electron transport chain (METC) in cancer cells, which further affects the production of ATP, mitochondrial membrane potential, and microdistribution of calcium, and induces cell apoptosis. Additionally, SPIONs induce the formation of reactive oxygen species in mitochondria; these reactive oxygen species trigger cancer-specific cytotoxicity due to the lower antioxidative capacity of cancer cells. Moreover, the DNA microarray and gene ontology analyses revealed that SPIONs elevate the expression of metallothioneins in both normal and cancer cells but decrease the expression of METC genes in cancer cells. Overall, these results suggest that SPIONs induce cancer cell death by targeting the METC, which is helpful for designing anti-cancer nanotheranostics and evaluating the safety of future nanomedicines. Copyright © 2016 Elsevier Ltd. All rights reserved.

Redox regulation of genome stability by effects on gene expression, epigenetic pathways and DNA damage/repair

PubMed Central

Mikhed, Yuliya; Görlach, Agnes; Knaus, Ulla G.; Daiber, Andreas

2015-01-01

Reactive oxygen and nitrogen species (e.g. H2O2, nitric oxide) confer redox regulation of essential cellular signaling pathways such as cell differentiation, proliferation, migration and apoptosis. In addition, classical regulation of gene expression or activity, including gene transcription to RNA followed by translation to the protein level, by transcription factors (e.g. NF-κB, HIF-1α) and mRNA binding proteins (e.g. GAPDH, HuR) is subject to redox regulation. This review will give an update of recent discoveries in this field, and specifically highlight the impact of reactive oxygen and nitrogen species on DNA repair systems that contribute to genomic stability. Emphasis will be placed on the emerging role of redox mechanisms regulating epigenetic pathways (e.g. miRNA, DNA methylation and histone modifications). By providing clinical correlations we discuss how oxidative stress can impact on gene regulation/activity and vise versa, how epigenetic processes, other gene regulatory mechanisms and DNA repair can influence the cellular redox state and contribute or prevent development or progression of disease. PMID:26079210

Effect of Penicillium mycotoxins on the cytokine gene expression, reactive oxygen species production, and phagocytosis of bovine macrophage (BoMacs) function.

PubMed

Oh, Se-Young; Mead, Philip J; Sharma, Bhawani S; Quinton, V Margaret; Boermans, Herman J; Smith, Trevor K; Swamy, H V L N; Karrow, Niel A

2015-12-25

Bovine macrophages (BoMacs) were exposed to the following Penicillium mycotoxins (PM): citrinin (CIT), ochratoxin A (OTA), patulin (PAT), mycophenolic acid (MPA) and penicillic acid (PA). PM exposure at the concentration that inhibits proliferation by 25% (IC25) differentially for 24h altered the gene expression of various cytokines. OTA significantly induced IL-1α expression (p<0.05), while the expression of IL-6 was suppressed (p<0.01). MPA significantly induced the expression of IL-1α (p<0.05) and reduced the expression of IL-12α (p<0.01) and IL-10 (p<0.01). PAT significantly suppressed the expression of IL-23 (p<0.01), IL-10 (p<0.05) and TGF-β (p<0.05). Some PMs also affected reactive oxygen species (ROS) and phagocytosis of Mycobacterium avium ssp. Paratuberculosis (MAP) at higher concentrations. PAT and PA for example, significantly decreased the percent phagocytosis of MAP at 5.0 (p<0.01) and 15.6 μM (p<0.01), respectively, but only PA significantly suppressed PAM-3-stimulated ROS production at 62.5 (p<0.05) and 250.0 μM (p<0.01). OTA significantly increased the percent phagocytosis of MAP at 6.3 (p<0.05) and 12.5 μM (p<0.01). These findings suggest that exposure to sub-lethal concentrations of PMs can affect macrophage function, which could affect immunoregulation and innate disease resistance to pathogens. Copyright © 2015 Elsevier Ltd. All rights reserved.

NADPH oxidase 1 supports proliferation of colon cancer cells by modulating reactive oxygen species-dependent signal transduction

PubMed Central

Juhasz, Agnes; Markel, Susan; Gaur, Shikha; Liu, Han; Lu, Jiamo; Jiang, Guojian; Wu, Xiwei; Antony, Smitha; Wu, Yongzhong; Melillo, Giovanni; Meitzler, Jennifer L.; Haines, Diana C.; Butcher, Donna; Roy, Krishnendu; Doroshow, James H.

2017-01-01

Reactive oxygen species (ROS) play a critical role in cell signaling and proliferation. NADPH oxidase 1 (NOX1), a membrane-bound flavin dehydrogenase that generates O2˙̄, is highly expressed in colon cancer. To investigate the role that NOX1 plays in colon cancer growth, we used shRNA to decrease NOX1 expression stably in HT-29 human colon cancer cells. The 80–90% decrease in NOX1 expression achieved by RNAi produced a significant decline in ROS production and a G1/S block that translated into a 2–3-fold increase in tumor cell doubling time without increased apoptosis. The block at the G1/S checkpoint was associated with a significant decrease in cyclin D1 expression and profound inhibition of mitogen-activated protein kinase (MAPK) signaling. Decreased steady-state MAPK phosphorylation occurred concomitant with a significant increase in protein phosphatase activity for two colon cancer cell lines in which NOX1 expression was knocked down by RNAi. Diminished NOX1 expression also contributed to decreased growth, blood vessel density, and VEGF and hypoxia-inducible factor 1α (HIF-1α) expression in HT-29 xenografts initiated from NOX1 knockdown cells. Microarray analysis, supplemented by real-time PCR and Western blotting, revealed that the expression of critical regulators of cell proliferation and angiogenesis, including c-MYC, c-MYB, and VEGF, were down-regulated in association with a decline in hypoxic HIF-1α protein expression downstream of silenced NOX1 in both colon cancer cell lines and xenografts. These studies suggest a role for NOX1 in maintaining the proliferative phenotype of some colon cancers and the potential of NOX1 as a therapeutic target in this disease. PMID:28330872

S100A8/A9 Drives Neuroinflammatory Priming and Protects against Anxiety-like Behavior after Sepsis.

PubMed

Denstaedt, Scott J; Spencer-Segal, Joanna L; Newstead, Michael W; Laborc, Klaudia; Zhao, Anne P; Hjelmaas, Alexander; Zeng, Xianying; Akil, Huda; Standiford, Theodore J; Singer, Benjamin H

2018-05-01

Sepsis commonly results in acute and chronic brain dysfunction, which dramatically increases the morbidity associated with this common disease. Chronic brain dysfunction in animal models of sepsis survival is linked to persistent neuroinflammation and expression of multiple cytokines. However, we have found previously that microglia predominantly upregulate the damage associated molecule S100A8/A9 after sepsis. In this article, we show that S100A8/A9 is increased in the brains of patients who died of sepsis and that S100A8 is expressed in astrocytes and myeloid cells. Using a mouse model of sepsis survival, we show that S100A8/A9 is persistently expressed in the brain after sepsis. S100A9 expression is necessary for recruitment of neutrophils to the brain and for priming production of reactive oxygen species and TNF-α secretion in microglia and macrophages. However, despite improving these indices of chronic inflammation, S100A9 deficiency results in worsened anxiety-like behavior 2 wk after sepsis. Taken together, these results indicate that S100A8/A9 contributes to several facets of neuroinflammation in sepsis survivor mice, including granulocyte recruitment and priming of microglial-reactive oxygen species and cytokine production, and that these processes may be protective against anxiety behavior in sepsis survivors. Copyright © 2018 by The American Association of Immunologists, Inc.

ABNORMAL INFLORESCENCE MERISTEM1 Functions in Salicylic Acid Biosynthesis to Maintain Proper Reactive Oxygen Species Levels for Root Meristem Activity in Rice

PubMed Central

Zhao, Hongyu; Ruan, Wenyuan; Deng, Minjuan; Wang, Fang; Peng, Jinrong; Luo, Jie; Chen, Zhixiang

2017-01-01

Root meristem activity determines root growth and root architecture and consequently affects water and nutrient uptake in plants. However, our knowledge about the regulation of root meristem activity in crop plants is very limited. Here, we report the isolation and characterization of a short root mutant in rice (Oryza sativa) with reduced root meristem activity. This root growth defect is caused by a mutation in ABNORMAL INFLORESCENCE MERISTEM1 (AIM1), which encodes a 3-hydroxyacyl-CoA dehydrogenase, an enzyme involved in β-oxidation. The reduced root meristem activity of aim1 results from reduced salicylic acid (SA) levels and can be rescued by SA application. Furthermore, reduced SA levels are associated with reduced levels of reactive oxygen species (ROS) in aim1, likely due to increased expression of redox and ROS-scavenging-related genes, whose increased expression is (at least in part) caused by reduced expression of the SA-inducible transcriptional repressors WRKY62 and WRKY76. Like SA, ROS application substantially increased root length and root meristem activity in aim1. These results suggest that AIM1 is required for root growth in rice due to its critical role in SA biosynthesis: SA maintains root meristem activity through promoting ROS accumulation by inducing the activity of WRKY transcriptional repressors, which repress the expression of redox and ROS-scavenging genes. PMID:28298519

Peptidoglycan and lipoteichoic acid, components of the streptococcal cell wall, have marked and differential effects on adhesion molecule expression and the production of reactive oxygen species in human whole blood leukocytes.

PubMed

Saetre, T; Kähler, H; Foster, S J; Lyberg, T

2000-07-01

To elucidate the pathophysiology of infections with Streptococcus pyogenes we applied flow cytometric techniques to study dose-response and time-related effects of the streptococcal cell-wall-derived components lipoteichoic acid (LTA 0.005 to 50 microg/ml) and peptidoglycan (10 and 100 microg/ml) on the expression of leukocyte adhesion molecules, the CD14 receptor, and the production of leukocyte reactive oxygen species (ROS). LTA (50 microg/ml, 1-2 h) markedly increased the expression of CD11b (approximately 5-fold), CD11c (approximately 2-fold) and CD11a. Concomitantly, CD62L was downregulated (60%). Peptidoglycan alone or in combination with LTA had little effect on adhesion molecules, except for an amplification of the downregulation of CD62L to 90%. Monocyte CD14 expression was doubled by LTA. Leukocyte ROS production was 10-fold and 5-fold increased by peptidoglycan in granulocytes and monocytes, respectively. LTA alone had no effect, while the combination of peptidoglycan with LTA doubled the increase in ROS caused by peptidoglycan. LTA and peptidoglycan had marked and differential effects: LTA caused mainly adhesion molecule modulation, whereas peptidoglycan mainly increased ROS production. These changes are important in inflammatory cell activation and recruitment, intracellular microbial killing and adverse tissue injury.

Glutathione peroxidase 4 overexpression inhibits ROS-induced cell death in diffuse large B-cell lymphoma.

PubMed

Kinowaki, Yuko; Kurata, Morito; Ishibashi, Sachiko; Ikeda, Masumi; Tatsuzawa, Anna; Yamamoto, Masahide; Miura, Osamu; Kitagawa, Masanobu; Yamamoto, Kouhei

2018-02-20

Regulation of oxidative stress and redox systems has important roles in carcinogenesis and cancer progression, and for this reason has attracted much attention as a new area of cancer therapeutic targets. Glutathione peroxidase 4 (GPX4), an antioxidant enzyme, has biological important functions such as signaling cell death by suppressing peroxidation of membrane phospholipids. However, few studies exist on the expression and clinical relevance of GPX4 in malignant lymphomas such as diffuse large B-cell lymphoma. In this study, we assessed the expression of GPX4 immunohistochemically. GPX4 was expressed in 35.5% (33/93) cases of diffuse large B-cell lymphoma. The GPX4-positive group had poor overall survival (P = 0.0032) and progression-free survival (P = 0.0004) compared with those of the GPX4-negative group. In a combined analysis of GPX4 and 8-hydroxydeoxyguanosine (8-OHdG), an oxidative stress marker, there was a negative correlation between GPX4 and 8-hydroxydeoxyguanosine (P = 0.0009). The GPX4-positive and 8-hydroxydeoxyguanosine-negative groups had a significantly worse prognosis than the other groups in both overall survival (P = 0.0170) and progression-free survival (P = 0.0005). These results suggest that the overexpression of GPX4 is an independent prognostic predictor in diffuse large B-cell lymphoma. Furthermore, in vitro analysis demonstrated that GPX4-overexpressing cells were resistant to reactive oxygen species-induced cell death (P = 0.0360). Conversely, GPX4-knockdown cells were sensitive to reactive oxygen species-induced cell death (P = 0.0111). From these data, we conclude that GPX4 regulates reactive oxygen species-induced cell death. Our results suggest a novel therapeutic strategy using the mechanism of ferroptosis, as well as a novel prognostic predictor of diffuse large B-cell lymphoma.

Fundamental roles of reactive oxygen species and protective mechanisms in the female reproductive system.

PubMed

Fujii, Junichi; Iuchi, Yoshihito; Okada, Futoshi

2005-09-02

Controlled oxidation, such as disulfide bond formation in sperm nuclei and during ovulation, plays a fundamental role in mammalian reproduction. Excess oxidation, however, causes oxidative stress, resulting in the dysfunction of the reproductive process. Antioxidation reactions that reduce the levels of reactive oxygen species are of prime importance in reproductive systems in maintaining the quality of gametes and support reproduction. While anti-oxidative enzymes, such as superoxide dismutase and peroxidase, play a central role in eliminating oxidative stress, reduction-oxidation (redox) systems, comprised of mainly glutathione and thioredoxin, function to reduce the levels of oxidized molecules. Aldo-keto reductase, using NADPH as an electron donor, detoxifies carbonyl compounds resulting from the oxidation of lipids and proteins. Thus, many antioxidative and redox enzyme genes are expressed and aggressively protect gametes and embryos in reproductive systems.

Selection of the in vitro culture media influences mRNA expression of Hedgehog genes, Il-6, and important genes regarding reactive oxygen species in single murine preimplantation embryos.

PubMed

Pfeifer, N; Baston-Büst, D M; Hirchenhain, J; Friebe-Hoffmann, U; Rein, D T; Krüssel, J S; Hess, A P

2012-01-01

The aim of this paper was to determine the influence of different in vitro culture media on mRNA expression of Hedgehog genes, il-6, and important genes regarding reactive oxygen species in single mouse embryos. Reverse transcription of single embryos either cultured in vitro from day 0.5 until 3.5 (COOK's Cleavage medium or Vitrolife's G-1 PLUS medium) or in vivo until day 3.5 post coitum. PCR was carried out for β-actin followed by nested-PCR for shh, ihh, il-6, nox, gpx4, gpx1, and prdx2. The number of murine blastocysts cultured in COOK medium which expressed il-6, gpx4, gpx1, and prdx2 mRNA differed significantly compared to the in vivo group. Except for nox, the mRNA profile of the Vitrolife media group embryos varied significantly from the in vivo ones regarding the number of blastocysts expressing the mRNA of shh, ihh, il-6, gpx4, gpx1 and prdx2. The present study shows that different in vitro culture media lead to different mRNA expression profiles during early development. Even the newly developed in vitro culture media are not able to mimic the female reproductive tract. The question of long-term consequences for children due to assisted reproduction techniques needs to be addressed in larger studies.

Selection of the In Vitro Culture Media Influences mRNA Expression of Hedgehog Genes, Il-6, and Important Genes regarding Reactive Oxygen Species in Single Murine Preimplantation Embryos

PubMed Central

Pfeifer, N.; Baston-Büst, D. M.; Hirchenhain, J.; Friebe-Hoffmann, U.; Rein, D. T.; Krüssel, J. S.; Hess, A. P.

2012-01-01

Background. The aim of this paper was to determine the influence of different in vitro culture media on mRNA expression of Hedgehog genes, il-6, and important genes regarding reactive oxygen species in single mouse embryos. Methods. Reverse transcription of single embryos either cultured in vitro from day 0.5 until 3.5 (COOK's Cleavage medium or Vitrolife's G-1 PLUS medium) or in vivo until day 3.5 post coitum. PCR was carried out for β-actin followed by nested-PCR for shh, ihh, il-6, nox, gpx4, gpx1, and prdx2. Results. The number of murine blastocysts cultured in COOK medium which expressed il-6, gpx4, gpx1, and prdx2 mRNA differed significantly compared to the in vivo group. Except for nox, the mRNA profile of the Vitrolife media group embryos varied significantly from the in vivo ones regarding the number of blastocysts expressing the mRNA of shh, ihh, il-6, gpx4, gpx1 and prdx2. Conclusions. The present study shows that different in vitro culture media lead to different mRNA expression profiles during early development. Even the newly developed in vitro culture media are not able to mimic the female reproductive tract. The question of long-term consequences for children due to assisted reproduction techniques needs to be addressed in larger studies. PMID:22919324

Feed gas contaminant removal in ion transport membrane systems

DOEpatents

Underwood, Richard Paul [Allentown, PA; Makitka, III, Alexander; Carolan, Michael Francis [Allentown, PA

2012-04-03

An oxygen ion transport membrane process wherein a heated oxygen-containing gas having one or more contaminants is contacted with a reactive solid material to remove the one or more contaminants. The reactive solid material is provided as a deposit on a support. The one or more contaminant compounds in the heated oxygen-containing gas react with the reactive solid material. The contaminant-depleted oxygen-containing gas is contacted with a membrane, and oxygen is transported through the membrane to provide transported oxygen.

Autophagic cell death induced by reactive oxygen species is involved in hyperthermic sensitization to ionizing radiation in human hepatocellular carcinoma cells.

PubMed

Yuan, Guang-Jin; Deng, Jun-Jian; Cao, De-Dong; Shi, Lei; Chen, Xin; Lei, Jin-Ju; Xu, Xi-Ming

2017-08-14

To investigate whether autophagic cell death is involved in hyperthermic sensitization to ionizing radiation in human hepatocellular carcinoma cells, and to explore the underlying mechanism. Human hepatocellular carcinoma cells were treated with hyperthermia and ionizing radiation. MTT and clonogenic assays were performed to determine cell survival. Cell autophagy was detected using acridine orange staining and flow cytometric analysis, and the expression of autophagy-associated proteins, LC3 and p62, was determined by Western blot analysis. Intracellular reactive oxygen species (ROS) were quantified using the fluorescent probe DCFH-DA. Treatment with hyperthermia and ionizing radiation significantly decreased cell viability and surviving fraction as compared with hyperthermia or ionizing radiation alone. Cell autophagy was significantly increased after ionizing radiation combined with hyperthermia treatment, as evidenced by increased formation of acidic vesicular organelles, increased expression of LC3II and decreased expression of p62. Intracellular ROS were also increased after combined treatment with hyperthermia and ionizing radiation. Pretreatment with N-acetylcysteine, an ROS scavenger, markedly inhibited the cytotoxicity and cell autophagy induced by hyperthermia and ionizing radiation. Autophagic cell death is involved in hyperthermic sensitization of cancer cells to ionizing radiation, and its induction may be due to the increased intracellular ROS.

Advanced glycation end products promote ChREBP expression and cell proliferation in liver cancer cells by increasing reactive oxygen species.

PubMed

Chen, Hanbei; Li, Yakui; Zhu, Yemin; Wu, Lifang; Meng, Jian; Lin, Ning; Yang, Dianqiang; Li, Minle; Ding, WenJin; Tong, Xuemei; Su, Qing

2017-08-01

The aim of the study was to elucidate the mechanism by which advanced glycation end products (AGEs) promote cell proliferation in liver cancer cells.We treated liver cancer HepG2 cells with 200 mg/L AGEs or bovine serum albumin (BSA) and assayed for cell viability, cell cycle, and apoptosis. We performed real-time PCR and Western blot analysis for RNA and protein levels of carbohydrate responsive element-binding protein (ChREBP) in AGEs- or BSA-treated HepG2 cells. We analyzed the level of reactive oxygen species (ROS) in HepG2 cells treated with AGEs or BSA.We found that increased S-phase cell percentage and decreased apoptosis contributed to AGEs-induced liver cancer cell proliferation. Real-time PCR and Western blot analysis showed that AGEs stimulated RNA and protein levels of ChREBP, a transcription factor promoting glycolysis and maintaining cell proliferation in liver cancer cells. Intriguingly, the level of ROS was higher in AGEs-treated liver cancer cells. Treating liver cancer cells with antioxidant N-acetyl cystein (NAC) partly blocked AGEs-induced ChREBP expression and cell proliferation.Our results suggest that the AGEs-ROS-ChREBP pathway plays a critical role in promoting ChREBP expression and liver cancer cell proliferation.

FITNESS, a CCT domain-containing protein, deregulates reactive oxygen species levels and leads to fine-tuning trade-offs between reproductive success and defense responses in Arabidopsis.

PubMed

Osella, Ana Virginia; Mengarelli, Diego Alberto; Mateos, Julieta; Dong, Shuchao; Yanovsky, Marcelo J; Balazadeh, Salma; Valle, Estela Marta; Zanor, María Inés

2018-05-31

Environmental stresses are the major factors that limit productivity in plants. Here, we report on the function of an uncharacterized gene At1g07050, encoding a CCT domain-containing protein, from Arabidopsis thaliana. At1g07050 expression is highly repressed by oxidative stress. We used metabolomics, biochemical and genomic approaches to analyze performance of transgenic lines with altered expression of At1g07050 under normal and oxidative stress conditions. At1g07050 overexpressing lines showed increased levels of reactive oxygen species (ROS) while knock-out mutants exhibited decreased levels of ROS and higher tolerance to oxidative stress generated in the chloroplast. Our results uncover a role for At1g07050 in cellular redox homeostasis controlling H 2 O 2 levels, due to changes in enzymes, metabolites and transcripts related to ROS detoxification. Therefore, we call this gene FITNESS. Additionally, several genes such as ACD6, PCC1, and ICS1 related to SA signalling and defense were found differentially expressed among the lines. Notably, FITNESS absence significantly improved seed yield suggesting an effective fine-tuning trade-off between reproductive success and defense responses. This article is protected by copyright. All rights reserved.

Generation of Reactive Oxygen Species via NOXa Is Important for Development and Pathogenicity of Mycosphaerella graminicola.

PubMed

Choi, Yoon-E; Lee, Changsu; Goodwin, Stephen B

2016-03-01

The ascomycete fungus Mycosphaerella graminicola (synonym Zymoseptoria tritici) is an important pathogen of wheat causing economically significant losses. The primary nutritional mode of this fungus is thought to be hemibiotrophic. This pathogenic lifestyle is associated with an early biotrophic stage of nutrient uptake followed by a necrotrophic stage aided possibly by production of a toxin or reactive oxygen species (ROS). In many other fungi, the genes CREA and AREA are important during the biotrophic stage of infection, while the NOXa gene product is important during necrotrophic growth. To test the hypothesis that these genes are important for pathogenicity of M. graminicola, we employed an over-expression strategy for the selected target genes CREA, AREA, and NOXa, which might function as regulators of nutrient acquisition or ROS generation. Increased expressions of CREA, AREA, and NOXa in M. graminicola were confirmed via quantitative real-time PCR and strains were subsequently assayed for pathogenicity. Among them, the NOXa over-expression strain, NO2, resulted in significantly increased virulence. Moreover, instead of the usual filamentous growth, we observed a predominance of yeast-like growth of NO2 which was correlated with ROS production. Our data indicate that ROS generation via NOXa is important to pathogenicity as well as development in M. graminicola.

Zinc oxide nanoparticles inhibit murine photoreceptor-derived cell proliferation and migration via reducing TGF-β and MMP-9 expression in vitro.

PubMed

Guo, Da Dong; Li, Qing Ning; Li, Chun Min; Bi, Hong Sheng

2015-04-01

To investigate behaviour and expression of transforming growth factor-β (TGF-β) and matrix metalloproteinases (MMP-9) in murine photoreceptor-derived cells (661W) after incubation with zinc oxide (ZnO) nanoparticles. We explored effects of ZnO nanoparticles on 661W cells using a real-time cell electronic sensing system, flow cytometry, multiple function microplate reading, real-time quantitative PCR detection system and enzyme-linked immunosorbent assay respectively. Our results indicate that ZnO nanoparticles induced overload of calcium and reactive oxygen species within cells, causing formation of apoptotic bodies, disruption of cell cycle distribution, and reduction in expression of TGF-β and MMP-9, to suppress cell proliferation and migration. Our findings show that disruption of intracellular calcium homoeostasis and overproduction of reactive oxygen species were closely associated with reduction of TGF-β and MMP-9 in 661W cells under ZnO nanoparticle treatment. Results of our study indicate that ZnO nanoparticles suppressed cell proliferation and migration, and reduced production of TGF-β and MMP-9 at both gene and protein levels. Our findings contribute to the understanding of the molecular mechanisms that reduced TGF-β and MMP-9 levels inhibit cell proliferation and migration under ZnO nanoparticle influence. © 2015 John Wiley & Sons Ltd.

Cellular and molecular mechanisms in the hypoxic tissue: role of HIF-1 and ROS.

PubMed

Zepeda, Andrea B; Pessoa, Adalberto; Castillo, Rodrigo L; Figueroa, Carolina A; Pulgar, Victor M; Farías, Jorge G

2013-08-01

Reactive oxygen species such as superoxide anion radicals (O2 (-) ) and hydrogen peroxide (H2 O2 ) have for long time been recognized as undesirable by-products of the oxidative mitochondrial generation of adenosine triphosphate (ATP). Recently, these highly reactive species have been associated to important signaling pathways in diverse physiological conditions such as those activated in hypoxic microenvironments. The molecular response to hypoxia requires fast-acting mechanisms acting within a wide range of partial pressures of oxygen (O2 ). Intracellular O2 sensing is an evolutionary preserved feature, and the best characterized molecular responses to hypoxia are mediated through transcriptional activation. The transcription factor, hypoxia-inducible factor 1 (HIF-1), is a critical mediator of these adaptive responses, and its activation by hypoxia involves O2 -dependent posttranslational modifications and nuclear translocation. Through the induction of the expression of its target genes, HIF-1 coordinately regulates tissue O2 supply and energetic metabolism. Other transcription factors such as nuclear factor κB are also redox sensitive and are activated in pro-oxidant and hypoxic conditions. The purpose of this review is to summarize new developments in HIF-mediated O2 sensing mechanisms and their interactions with reactive oxygen species-generating pathways in normal and abnormal physiology. Copyright © 2013 John Wiley & Sons, Ltd.

Functional characterization of a reactive oxygen species modulator 1 gene in Litopenaeus vannamei.

PubMed

He, Hong-Hui; Chi, Yi-Miao; Yuan, Kai; Li, Xiao-Yun; Weng, Shao-Ping; He, Jian-Guo; Chen, Yi-Hong

2017-11-01

Reactive oxygen species (ROS) imparts a dual effect on multicellular organisms, wherein high levels are usually harmful, and low levels could facilitate in combating pathogenic microorganisms; therefore, the regulation of ROS production is critical. Previous studies have suggested that ROS contributes to resistance to the white spot syndrome virus (WSSV) or Vibrio alginolyticus in Litopenaeus vannamei. However, the regulation of ROS metabolism in L. vannamei remains elusive. In the present study, we proved that the overexpression of L. vannamei reactive oxygen species modulator 1 (LvROMO1) increases ROS production in Drosophila Schneider 2 (S2) cells. Real-time RT-PCR analysis indicated that LvROMO1 is induced by WSSV or V. alginolyticus infection and β-glucan or microcystin (MC-LR) injection. Further investigation showed that LvROMO1 responding to MC-LR, thereby inducing hemocytes to undergo apoptosis, and ultimately resulting in hepatopancreatic damage. And LvROMO1 downregulation induced an increase in the cumulative mortality of WSSV-infected shrimp by reducing ROS production and suppressing the expression of antimicrobial peptides genes. The findings of present study suggest that LvROMO1 plays an important role in ROS production in L. vannamei and is involved in innate immunity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biochemistry of free radicals: from electrons to tissues.

PubMed

Boveris, A

1998-01-01

Free radicals are chemical species with an unpaired electron in the outer valence orbitals. The unpaired electron makes them paramagnetic (physics) and relatively reactive (chemistry). The free radicals that are normal metabolites in aerobic biological systems have varied reactivities, ranging from the high reactivity of hydroxyl radical (t1/2 = 10(-9) s) to the low reactivity of melanins (t1/2 = days). The univalent reduction of oxygen that takes place in mammalian organs produces superoxide radicals at a rate of about 2% of the total oxygen uptake. The primary production of superoxide radicals sustains a free radical chain reaction involving a series of reactive oxygen species (hydrogen peroxide, hydroxyl and peroxyl radical and singlet oxygen). Nitric oxide is almost unreactive as free radical except for its termination reaction with superoxide radical to yield the strong oxidant peroxynitrite. Nitric oxide also reacts with ubiquinol in a redox reaction, with cytochrome oxidase competitively with oxygen, and oxymyoglobin and oxyhemoglobin displacing oxygen. Septic shock and endotoxemia produce muscle dysfunction and oxidative stress due to increased steady state concentrations of reactive oxygen and nitrogen species.

Aeroallergens Induce Reactive Oxygen Species Production and DNA Damage and Dampen Antioxidant Responses in Bronchial Epithelial Cells.

PubMed

Chan, Tze Khee; Tan, W S Daniel; Peh, Hong Yong; Wong, W S Fred

2017-07-01

Exposure to environmental allergens is a major risk factor for asthma development. Allergens possess proteolytic activity that is capable of disrupting the airway epithelium. Although there is increasing evidence pointing to asthma as an epithelial disease, the underlying mechanism that drives asthma has not been fully elucidated. In this study, we investigated the direct DNA damage potential of aeroallergens on human bronchial epithelial cells and elucidated the mechanisms mediating the damage. Human bronchial epithelial cells, BEAS-2B, directly exposed to house dust mites (HDM) resulted in enhanced DNA damage, as measured by the CometChip and the staining of DNA double-strand break marker, γH2AX. HDM stimulated cellular reactive oxygen species production, increased mitochondrial oxidative stress, and promoted nitrosative stress. Notably, expression of nuclear factor erythroid 2-related factor 2-dependent antioxidant genes was reduced immediately after HDM exposure, suggesting that HDM altered antioxidant responses. HDM exposure also reduced cell proliferation and induced cell death. Importantly, HDM-induced DNA damage can be prevented by the antioxidants glutathione and catalase, suggesting that HDM-induced reactive oxygen and nitrogen species can be neutralized by antioxidants. Mechanistic studies revealed that HDM-induced cellular injury is NADPH oxidase (NOX)-dependent, and apocynin, a NOX inhibitor, protected cells from double-strand breaks induced by HDM. Our results show that direct exposure of bronchial epithelial cells to HDM leads to the production of reactive oxygen and nitrogen species that damage DNA and induce cytotoxicity. Antioxidants and NOX inhibitors can prevent HDM-induced DNA damage, revealing a novel role for antioxidants and NOX inhibitors in mitigating allergic airway disease. Copyright © 2017 by The American Association of Immunologists, Inc.

Decitabine induces delayed reactive oxygen species (ROS) accumulation in leukemia cells and induces the expression of ROS generating enzymes.

PubMed

Fandy, Tamer E; Jiemjit, Anchalee; Thakar, Manjusha; Rhoden, Paulette; Suarez, Lauren; Gore, Steven D

2014-03-01

Azanucleoside DNA methyltransferase (DNMT) inhibitors are currently approved by the U.S. Food and Drug Administration for treatment of myelodysplastic syndrome. The relative contributions of DNMT inhibition and other off-target effects to their clinical efficacy remain unclear. Data correlating DNA methylation reversal and clinical response have been conflicting. Consequently, it is necessary to investigate so-called off-target effects and their impact on cell survival and differentiation. Flow cytometry was used for cell cycle, apoptosis, and reactive oxygen species (ROS) accumulation analysis. Gene expression analysis was performed using real-time PCR. DNA methylation was detected by methylation-specific PCR. Mitochondrial membrane potential was analyzed using JC-1 dye staining. Western blotting was used for quantitative protein expression analysis. 5-Aza-2'-deoxycytidine (DAC) induced cell-cycle arrest and apoptosis in leukemia cells. p53 expression was dispensable for DAC-induced apoptosis. DAC induced delayed ROS accumulation in leukemia cells but not in solid tumor cells and p53 expression was dispensable for ROS increase. ROS increase was deoxycytidine kinase dependent, indicating that incorporation of DAC into nuclear DNA is required for ROS generation. ROS accumulation by DAC was caspase-independent and mediated the dissipation of the mitochondrial membrane potential. Concordantly, ROS scavengers diminished DAC-induced apoptosis. DAC induced the expression of different NADPH oxidase isoforms and upregulated Nox4 protein expression in an ATM-dependent manner, indicating the involvement of DNA damage signaling in Nox4 upregulation. These data highlight the importance of mechanisms other than DNA cytosine demethylation in modulating gene expression and suggest investigating the relevance of ROS accumulation to the clinical activity of DAC. ©2014 AACR

Environmental stress alters genes expression and induces ovule abortion: reactive oxygen species appear as ovules commit to abort.

PubMed

Sun, Kelian; Cui, Yuehua; Hauser, Bernard A

2005-11-01

Environmental stress dramatically reduces plant reproduction. Previous results showed that placing roots in 200 mM NaCl for 12 h caused 90% of the developing Arabidopsis ovules to abort (Sun et al. in Plant Physiol 135:2358-2367, 2004). To discover the molecular responses that occur during ovule abortion, gene expression was monitored using Affymetrix 24k genome arrays. Transcript levels were measured in pistils that were stressed for 6, 12, 18, and 24 h, then compared with the levels in healthy pistils. Over the course of this experiment, a total of 535 salt-responsive genes were identified. Cluster analysis showed that differentially expressed genes exhibited reproducible changes in expression. The expression of 65 transcription factors, some of which are known to be involved in stress responses, were modulated during ovule abortion. In flowers, salt stress led to a 30-fold increase in Na+ ions and modest, but significant, decreases in the accumulation of other ions. The expression of cation exchangers and ion transporters were induced, presumably to reestablish ion homeostasis following salt stress. Genes that encode enzymes that detoxify reactive oxygen species (ROS), including ascorbate peroxidase and peroxidase, were downregulated after ovules committed to abort. These changes in gene expression coincided with the synthesis of ROS in female gametophytes. One day after salt stress, ROS spread from the gametophytes to the maternal chalaza and integuments. In addition, genes encoding proteins that regulate ethylene responses, including ethylene biosynthesis, ethylene signal transduction and ethylene-responsive transcription factors, were upregulated after stress. Hypotheses are proposed on the basis of this expression analysis, which will be evaluated further in future experiments.

Regulation of singlet oxygen-induced apoptosis by cytosolic NADP+-dependent isocitrate dehydrogenase.

PubMed

Kim, Sun Yee; Lee, Su Min; Tak, Jean Kyoung; Choi, Kyeong Sook; Kwon, Taeg Kyu; Park, Jeen-Woo

2007-08-01

Singlet oxygen is a highly reactive form of molecular oxygen that may harm living systems by oxidizing critical cellular macromolecules and it also promotes deleterious processes such as cell death. Recently, we demonstrated that the control of redox balance and the cellular defense against oxidative damage are the primary functions of cytosolic NADP(+)-dependent isocitrate dehydrogenase (IDPc) through supplying NADPH for antioxidant systems. In this report, we demonstrate that modulation of IDPc activity in HL-60 cells regulates singlet oxygen-induced apoptosis. When we examined the protective role of IDPc against singlet oxygen-induced apoptosis with HL-60 cells transfected with the cDNA for mouse IDPc in sense and antisense orientations, a clear inverse relationship was observed between the amount of IDPc expressed in target cells and their susceptibility to apoptosis. The results suggest that IDPc plays an important protective role in apoptosis of HL-60 cells induced by singlet oxygen.

Reactive Oxygen Species Signaling Facilitates FOXO-3a/FBXO-Dependent Vascular BK Channel β1 Subunit Degradation in Diabetic Mice

PubMed Central

Lu, Tong; Chai, Qiang; Yu, Ling; d’Uscio, Livius V.; Katusic, Zvonimir S.; He, Tongrong; Lee, Hon-Chi

2012-01-01

Activity of the vascular large conductance Ca2+-activated K+ (BK) channel is tightly regulated by its accessory β1 subunit (BK-β1). Downregulation of BK-β1 expression in diabetic vessels is associated with upregulation of the forkhead box O subfamily transcription factor-3a (FOXO-3a)–dependent F-box–only protein (FBXO) expression. However, the upstream signaling regulating this process is unclear. Overproduction of reactive oxygen species (ROS) is a common finding in diabetic vasculopathy. We hypothesized that ROS signaling cascade facilitates the FOXO-3a/FBXO-mediated BK-β1 degradation and leads to diabetic BK channel dysfunction. Using cellular biology, patch clamp, and videomicroscopy techniques, we found that reduced BK-β1 expression in streptozotocin (STZ)-induced diabetic mouse arteries and in human coronary smooth muscle cells (SMCs) cultured with high glucose was attributable to an increase in protein kinase C (PKC)-β and NADPH oxidase expressions and accompanied by attenuation of Akt phosphorylation and augmentation of atrogin-1 expression. Treatment with ruboxistaurin (a PKCβ inhibitor) or with GW501516 (a peroxisome proliferator–activated receptor δ activator) reduced atrogin-1 expression and restored BK channel-mediated coronary vasodilation in diabetic mice. Our results suggested that oxidative stress inhibited Akt signaling and facilitated the FOXO-3a/FBXO-dependent BK-β1 degradation in diabetic vessels. Suppression of the FOXO-3a/FBXO pathway prevented vascular BK-β1 degradation and protected coronary function in diabetes. PMID:22586590

Transgenic expression of the dicotyledonous pattern recognition receptor EFR in rice leads to ligand-dependent activation of defense responses

DOE PAGES

Schwessinger, Benjamin; Bahar, Ofir; Thomas, Nicolas; ...

2015-03-30

Plant plasma membrane localized pattern recognition receptors (PRRs) detect extracellular pathogen-associated molecules. PRRs such as Arabidopsis EFR and rice XA21 are taxonomically restricted and are absent from most plant genomes. Here we show that rice plants expressing EFR or the chimeric receptor EFR::XA21, containing the EFR ectodomain and the XA21 intracellular domain, sense both Escherichia coli- and Xanthomonas oryzae pv. oryzae (Xoo)-derived elf18 peptides at sub-nanomolar concentrations. Treatment of EFR and EFR::XA21 rice leaf tissue with elf18 leads to MAP kinase activation, reactive oxygen production and defense gene expression. Although expression of EFR does not lead to robust enhanced resistancemore » to fully virulent Xoo isolates, it does lead to quantitatively enhanced resistance to weakly virulent Xoo isolates. EFR interacts with OsSERK2 and the XA21 binding protein 24 (XB24), two key components of the rice XA21-mediated immune response. Rice-EFR plants silenced for OsSERK2, or overexpressing rice XB24 are compromised in elf18-induced reactive oxygen production and defense gene expression indicating that these proteins are also important for EFR-mediated signaling in transgenic rice. Taken together, our results demonstrate the potential feasibility of enhancing disease resistance in rice and possibly other monocotyledonous crop species by expression of dicotyledonous PRRs. Our results also suggest that Arabidopsis EFR utilizes at least a subset of the known endogenous rice XA21 signaling components.« less

Transgenic expression of the dicotyledonous pattern recognition receptor EFR in rice leads to ligand-dependent activation of defense responses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwessinger, Benjamin; Bahar, Ofir; Thomas, Nicolas

Plant plasma membrane localized pattern recognition receptors (PRRs) detect extracellular pathogen-associated molecules. PRRs such as Arabidopsis EFR and rice XA21 are taxonomically restricted and are absent from most plant genomes. Here we show that rice plants expressing EFR or the chimeric receptor EFR::XA21, containing the EFR ectodomain and the XA21 intracellular domain, sense both Escherichia coli- and Xanthomonas oryzae pv. oryzae (Xoo)-derived elf18 peptides at sub-nanomolar concentrations. Treatment of EFR and EFR::XA21 rice leaf tissue with elf18 leads to MAP kinase activation, reactive oxygen production and defense gene expression. Although expression of EFR does not lead to robust enhanced resistancemore » to fully virulent Xoo isolates, it does lead to quantitatively enhanced resistance to weakly virulent Xoo isolates. EFR interacts with OsSERK2 and the XA21 binding protein 24 (XB24), two key components of the rice XA21-mediated immune response. Rice-EFR plants silenced for OsSERK2, or overexpressing rice XB24 are compromised in elf18-induced reactive oxygen production and defense gene expression indicating that these proteins are also important for EFR-mediated signaling in transgenic rice. Taken together, our results demonstrate the potential feasibility of enhancing disease resistance in rice and possibly other monocotyledonous crop species by expression of dicotyledonous PRRs. Our results also suggest that Arabidopsis EFR utilizes at least a subset of the known endogenous rice XA21 signaling components.« less

Transcriptome Analysis Provides Insights into the Mechanisms Underlying Wheat Plant Resistance to Stripe Rust at the Adult Plant Stage

PubMed Central

Hao, Yingbin; Wang, Ting; Wang, Kang; Wang, Xiaojie; Fu, Yanping; Huang, Lili; Kang, Zhensheng

2016-01-01

Stripe rust (or yellow rust), which is caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most devastating wheat diseases worldwide. The wheat cultivar Xingzi 9104 (XZ) is an elite wheat germplasm that possesses adult plant resistance (APR), which is non–race-specific and durable. Thus, to better understand the mechanism underlying APR, we performed transcriptome sequencing of wheat seedlings and adult plants without Pst infection, and a total of 157,689 unigenes were obtained as a reference. In total, 2,666, 783 and 2,587 differentially expressed genes (DEGs) were found to be up- or down-regulated after Pst infection at 24, 48 and 120 hours post-inoculation (hpi), respectively, based on a comparison of Pst- and mock-infected plants. Among these unigenes, the temporal pattern of the up-regulated unigenes exhibited transient expression patterns during Pst infection, as determined through a Gene Ontology (GO) enrichment analysis. In addition, a Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that many biological processes, including phenylpropanoid biosynthesis, reactive oxygen species, photosynthesis and thiamine metabolism, which mainly control the mechanisms of lignification, reactive oxygen species and sugar, respectively, are involved in APR. In particular, the continuous accumulation of reactive oxygen species may potentially contribute to the ability of the adult plant to inhibit fungal growth and development. To validate the bioinformatics results, 6 candidate genes were selected for further functional identification using the virus-induced gene silencing (VIGS) system, and 4 candidate genes likely contribute to plant resistance against Pst infection. Our study provides new information concerning the transcriptional changes that occur during the Pst-wheat interaction at the adult stage and will help further our understanding of the detailed mechanisms underlying APR to Pst. PMID:26991894

Protective effects of myricitrin against osteoporosis via reducing reactive oxygen species and bone-resorbing cytokines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Qiang; Gao, Bo; Wang, Long

Oxidative stress is a crucial pathogenic factor in the development of osteoporosis. Myricitrin, isolated from Myrica cerifera, is a potent antioxidant. We hypothesized that myricitrin possessed protective effects against osteoporosis by partially reducing reactive oxygen species (ROS) and bone-resorbing cytokines in osteoblastic MC3T3-E1 cells and human bone marrow stromal cells (hBMSCs). We investigated myricitrin on osteogenic differentiation under oxidative stress. Hydrogen peroxide (H{sub 2}O{sub 2}) was used to establish an oxidative cell injury model. Our results revealed that myricitrin significantly improved some osteogenic markers in these cells. Myricitrin decreased lipid production and reduced peroxisome proliferator-activated receptor gamma-2 (PPARγ2) expression inmore » hBMSCs. Moreover, myricitrin reduced the expression of receptor activator of nuclear factor kappa-B ligand (RANKL) and IL-6 and partially suppressed ROS production. In vivo, we established a murine ovariectomized (OVX) osteoporosis model. Our results demonstrated that myricitrin supplementation reduced serum malondialdehyde (MDA) activity and increased reduced glutathione (GSH) activity. Importantly, it ameliorated the micro-architecture of trabecular bones in the 4th lumbar vertebrae (L4) and distal femur. Taken together, these results indicated that the protective effects of myricitrin against osteoporosis are linked to a reduction in ROS and bone-resorbing cytokines, suggesting that myricitrin may be useful in bone metabolism diseases, particularly osteoporosis. - Highlights: • Myricitrin protects MC3T3-E1 cells and hBMSCs from oxidative stress. • It is accompanied by a decrease in oxidative stress and bone-resorbing cytokines. • Myricitrin decreases serum reactive oxygen species to some degree. • Myricitrin partly reverses ovariectomy effects in vivo. • Myricitrin may represent a beneficial anti-osteoporosis treatment method.« less

RNA sequencing supports distinct reactive oxygen species-mediated pathways of apoptosis by high and low size mass fractions of Bay leaf (Lauris nobilis) in HT-29 cells.

PubMed

Rodd, Annabelle L; Ververis, Katherine; Sayakkarage, Dheeshana; Khan, Abdul W; Rafehi, Haloom; Ziemann, Mark; Loveridge, Shanon J; Lazarus, Ross; Kerr, Caroline; Lockett, Trevor; El-Osta, Assam; Karagiannis, Tom C; Bennett, Louise E

2015-08-01

Anti-proliferative and pro-apoptotic effects of Bay leaf (Laurus nobilis) in mammalian cancer and HT-29 adenocarcinoma cells have been previously attributed to effects of polyphenolic and essential oil chemical species. Recently, we demonstrated differentiated growth-regulating effects of high (HFBL) versus low molecular mass (LFBL) aqueous fractions of bay leaf and now confirm by comparative effects on gene expression, that HFBL and LFBL suppress HT-29 growth by distinct mechanisms. Induction of intra-cellular lesions including DNA strand breakage by extra-cellular HFBL, invoked the hypothesis that iron-mediated reactive oxygen species with capacity to penetrate cell membrane, were responsible for HFBL-mediated effects, supported by equivalent effects of HFBL in combination with γ radiation. Activities of HFBL and LFBL were interpreted to reflect differentiated responses to iron-mediated reactive oxygen species (ROS), occurring either outside or inside cells. In the presence of LFBL, apoptotic death was relatively delayed compared with HFBL. ROS production by LFBL mediated p53-dependent apoptosis and recovery was suppressed by promoting G1/S phase arrest and failure of cellular tight junctions. In comparison, intra-cellular anti-oxidant protection exerted by LFBL was absent for extra-cellular HFBL (likely polysaccharide-rich), which potentiated more rapid apoptosis by producing DNA double strand breaks. Differentiated effects on expression of genes regulating ROS defense and chromatic condensation by LFBL versus HFBL, were observed. The results support ferrous iron in cell culture systems and potentially in vivo, can invoke different extra-cellular versus intra-cellular ROS-mediated chemistries, that may be regulated by exogenous, including dietary species.

Anti-oxidative and anti-inflammatory effects of Tagetes minuta essential oil in activated macrophages

PubMed Central

Karimian, Parastoo; Kavoosi, Gholamreza; Amirghofran, Zahra

2014-01-01

Objective To investigate antioxidant and anti-inflammatory effects of Tagetes minuta (T. minuta) essential oil. Methods In the present study T. minuta essential oil was obtained from leaves of T. minuta via hydro-distillation and then was analyzed by gas chromatography-mass spectrometry. The anti-oxidant capacity of T. minuta essential oil was examined by measuring reactive oxygen, reactive nitrogen species and hydrogen peroxide scavenging. The anti-inflammatory activity of T. minuta essential oil was determined through measuring NADH oxidase, inducible nitric oxide synthase and TNF-α mRNA expression in lipopolysacharide-stimulated murine macrophages using real-time PCR. Results Gas chromatography-mass spectrometry analysis indicated that the main components in the T. minuta essential oil were dihydrotagetone (33.86%), E-ocimene (19.92%), tagetone (16.15%), cis-β-ocimene (7.94%), Z-ocimene (5.27%), limonene (3.1%) and epoxyocimene (2.03%). The T. minuta essential oil had the ability to scavenge all reactive oxygen/reactive nitrogen species radicals with IC50 12-15 µg/mL, which indicated a potent radical scavenging activity. In addition, T. minuta essential oil significantly reduced NADH oxidase, inducible nitric oxide synthaseand TNF-α mRNA expression in the cells at concentrations of 50 µg/mL, indicating a capacity of this product to potentially modulate/diminish immune responses. Conclusions T. minuta essential oil has radical scavenging and anti-inflammatory activities and could potentially be used as a safe effective source of natural anti-oxidants in therapy against oxidative damage and stress associated with some inflammatory conditions. PMID:25182441

Increasing the endogenous NO level causes catalase inactivation and reactivation of intercellular apoptosis signaling specifically in tumor cells

PubMed Central

Bauer, Georg

2015-01-01

Tumor cells generate extracellular superoxide anions and are protected against intercellular apoptosis-inducing HOCl- and NO/peroxynitrite signaling through the expression of membrane-associated catalase. This enzyme decomposes H2O2 and thus prevents HOCl synthesis. It efficiently interferes with NO/peroxynitrite signaling through oxidation of NO and decomposition of peroxynitrite. The regulatory potential of catalase at the crosspoint of ROS and RNS chemical biology, as well as its high local concentration on the outside of the cell membrane of tumor cells, establish tight control of intercellular signaling and thus prevent tumor cell apoptosis. Therefore, inhibition of catalase or its inactivation by singlet oxygen reactivate intercellular apoptosis-inducing signaling. Nitric oxide and peroxynitrite are connected with catalase in multiple and meaningful ways, as (i) NO can be oxidated by compound I of catalase, (ii) NO can reversibly inhibit catalase, (iii) peroxynitrite can be decomposed by catalase and (iv) the interaction between peroxynitrite and H2O2 leads to the generation of singlet oxygen that inactivates catalase. Therefore, modulation of the concentration of free NO through addition of arginine, inhibition of arginase, induction of NOS expression or inhibition of NO dioxygenase triggers an autoamplificatory biochemical cascade that is based on initial formation of singlet oxygen, amplification of superoxide anion/H2O2 and NO generation through singlet oxygen dependent stimulation of the FAS receptor and caspase-8. Finally, singlet oxygen is generated at sufficiently high concentration to inactivate protective catalase and to reactivate intercellular apoptosis-inducing ROS signaling. This regulatory network allows to establish several pathways for synergistic interactions, like the combination of modulators of NO metabolism with enhancers of superoxide anion generation, modulators of NO metabolism that act at different targets and between modulators of NO metabolism and direct catalase inhibitors. The latter aspect is explicitely studied for the interaction between catalase inhibiting acetylsalicylic acid and an NO donor. It is also shown that hybrid molecules like NO-aspirin utilize this synergistic potential. Our data open novel approaches for rational tumor therapy based on specific ROS signaling and its control in tumor cells. PMID:26342455

Responses of Aspergillus flavus to oxidative stress are related to fungal development regulator, antioxidant enzyme, and secondary metabolite biosynthetic gene expression

USDA-ARS?s Scientific Manuscript database

The infection of maize and peanut with Aspergillus flavus and subsequent contamination with aflatoxin pose a threat to global food safety and human health, and is exacerbated by drought stress. Drought stress-responding compounds such as reactive oxygen species (ROS) are associated with fungal stres...

Mechanism of superoxide and hydrogen peroxide generation by human electron-transfer flavoprotein and pathological variants.

PubMed

Rodrigues, João V; Gomes, Cláudio M

2012-07-01

Reactive oxygen species production by mitochondrial enzymes plays a fundamental role both in cellular signaling and in the progression of dysfunctional states. However, sources of reactive oxygen species and the mechanisms by which enzymes produce these reactive species still remain elusive. We characterized the generation of reactive oxygen species by purified human electron-transfer flavoprotein (ETF), a mitochondrial enzyme that has a central role in the metabolism of lipids, amino acids, and choline. The results showed that ETF produces significant amounts of both superoxide and hydrogen peroxide in the presence of its partner enzyme medium-chain acyl-CoA dehydrogenase (MCAD). ETF-mediated production of reactive oxygen species is partially inhibited at high MCAD/ETF ratios, whereas it is enhanced at high ionic strength. Determination of the reduction potentials of ETF showed that thermodynamic properties of the FAD cofactor are changed upon formation of a complex between ETF and MCAD, supporting the notion that protein:protein interactions modulate the reactivity of the protein with dioxygen. Two pathogenic ETF variants were also studied to determine which factors modulate the reactivity toward molecular oxygen and promote reactive oxygen species production. The results obtained show that destabilized conformations and defective protein:protein interactions increase the ability of ETF to generate reactive oxygen species. A possible role for these processes in mitochondrial dysfunction in metabolic disorders of fatty acid β-oxidation is discussed. Copyright © 2012 Elsevier Inc. All rights reserved.

Interaction of plant growth regulators and reactive oxygen species to regulate petal senescence in wallflowers (Erysimum linifolium).

PubMed

Salleh, Faezah Mohd; Mariotti, Lorenzo; Spadafora, Natasha D; Price, Anna M; Picciarelli, Piero; Wagstaff, Carol; Lombardi, Lara; Rogers, Hilary

2016-04-02

In many species floral senescence is coordinated by ethylene. Endogenous levels rise, and exogenous application accelerates senescence. Furthermore, floral senescence is often associated with increased reactive oxygen species, and is delayed by exogenously applied cytokinin. However, how these processes are linked remains largely unresolved. Erysimum linifolium (wallflower) provides an excellent model for understanding these interactions due to its easily staged flowers and close taxonomic relationship to Arabidopsis. This has facilitated microarray analysis of gene expression during petal senescence and provided gene markers for following the effects of treatments on different regulatory pathways. In detached Erysimum linifolium (wallflower) flowers ethylene production peaks in open flowers. Furthermore senescence is delayed by treatments with the ethylene signalling inhibitor silver thiosulphate, and accelerated with ethylene released by 2-chloroethylphosphonic acid. Both treatments with exogenous cytokinin, or 6-methyl purine (which is an inhibitor of cytokinin oxidase), delay petal senescence. However, treatment with cytokinin also increases ethylene biosynthesis. Despite the similar effects on senescence, transcript abundance of gene markers is affected differentially by the treatments. A significant rise in transcript abundance of WLS73 (a putative aminocyclopropanecarboxylate oxidase) was abolished by cytokinin or 6-methyl purine treatments. In contrast, WFSAG12 transcript (a senescence marker) continued to accumulate significantly, albeit at a reduced rate. Silver thiosulphate suppressed the increase in transcript abundance both of WFSAG12 and WLS73. Activity of reactive oxygen species scavenging enzymes changed during senescence. Treatments that increased cytokinin levels, or inhibited ethylene action, reduced accumulation of hydrogen peroxide. Furthermore, although auxin levels rose with senescence, treatments that delayed early senescence did not affect transcript abundance of WPS46, an auxin-induced gene. A model for the interaction between cytokinins, ethylene, reactive oxygen species and auxin in the regulation of floral senescence in wallflowers is proposed. The combined increase in ethylene and reduction in cytokinin triggers the initiation of senescence and these two plant growth regulators directly or indirectly result in increased reactive oxygen species levels. A fall in conjugated auxin and/or the total auxin pool eventually triggers abscission.

Cellular defense against singlet oxygen-induced oxidative damage by cytosolic NADP+-dependent isocitrate dehydrogenase.

PubMed

Kim, Sun Yee; Park, Jeen-Woo

2003-03-01

Singlet oxygen (1O2) is a highly reactive form of molecular oxygen that may harm living systems by oxidizing critical cellular macromolecules. Recently, we have shown that NADP+-dependent isocitrate dehydrogenase is involved in the supply of NADPH needed for GSH production against cellular oxidative damage. In this study, we investigated the role of cytosolic form of NADP+-dependent isocitrate dehydrogenase (IDPc) against singlet oxygen-induced cytotoxicity by comparing the relative degree of cellular responses in three different NIH3T3 cells with stable transfection with the cDNA for mouse IDPc in sense and antisense orientations, where IDPc activities were 2.3-fold higher and 39% lower, respectively, than that in the parental cells carrying the vector alone. Upon exposure to singlet oxygen generated from photoactivated dye, the cells with low levels of IDPc became more sensitive to cell killing. Lipid peroxidation, protein oxidation, oxidative DNA damage and intracellular peroxide generation were higher in the cell-line expressing the lower level of IDPc. However, the cells with the highly over-expressed IDPc exhibited enhanced resistance against singlet oxygen, compared to the control cells. The data indicate that IDPc plays an important role in cellular defense against singlet oxygen-induced oxidative injury.

Metabolic Response of Clostridium ljungdahlii to Oxygen Exposure

PubMed Central

Whitham, Jason M.; Tirado-Acevedo, Oscar; Chinn, Mari S.; Pawlak, Joel J.

2015-01-01

Clostridium ljungdahlii is an important synthesis gas-fermenting bacterium used in the biofuels industry, and a preliminary investigation showed that it has some tolerance to oxygen when cultured in rich mixotrophic medium. Batch cultures not only continue to grow and consume H2, CO, and fructose after 8% O2 exposure, but fermentation product analysis revealed an increase in ethanol concentration and decreased acetate concentration compared to non-oxygen-exposed cultures. In this study, the mechanisms for higher ethanol production and oxygen/reactive oxygen species (ROS) detoxification were identified using a combination of fermentation, transcriptome sequencing (RNA-seq) differential expression, and enzyme activity analyses. The results indicate that the higher ethanol and lower acetate concentrations were due to the carboxylic acid reductase activity of a more highly expressed predicted aldehyde oxidoreductase (CLJU_c24130) and that C. ljungdahlii's primary defense upon oxygen exposure is a predicted rubrerythrin (CLJU_c39340). The metabolic responses of higher ethanol production and oxygen/ROS detoxification were found to be linked by cofactor management and substrate and energy metabolism. This study contributes new insights into the physiology and metabolism of C. ljungdahlii and provides new genetic targets to generate C. ljungdahlii strains that produce more ethanol and are more tolerant to syngas contaminants. PMID:26431975

Fe-S Proteins that Regulate Gene Expression

PubMed Central

Mettert, Erin L.; Kiley, Patricia J.

2014-01-01

Iron-sulfur (Fe-S) cluster containing proteins that regulate gene expression are present in most organisms. The innate chemistry of their Fe-S cofactors makes these regulatory proteins ideal for sensing environmental signals, such as gases (e.g. O2 and NO), levels of Fe and Fe-S clusters, reactive oxygen species, and redox cycling compounds, to subsequently mediate an adaptive response. Here we review the recent findings that have provided invaluable insight into the mechanism and function of these highly significant Fe-S regulatory proteins. PMID:25450978

RNAi-Mediated Knockdown of Catalase Causes Cell Cycle Arrest in SL-1 Cells and Results in Low Survival Rate of Spodoptera litura (Fabricius)

PubMed Central

Hu, Meiying; Chen, Shaohua; Muhammad, Rizwan-ul-Haq; Dong, Xiaolin; Gong, Liang

2013-01-01

Deregulated reactive oxygen species (ROS) production can lead to the disruption of structural and functional integrity of cells as a consequence of reactive interaction between ROS and various biological components. Catalase (CAT) is a common enzyme existing in nearly all organisms exposed to oxygen, which decomposes harmful hydrogen peroxide, into water and oxygen. In this study, the full length sequence that encodes CAT-like protein from Spodoptera litura named siltCAT (GenBank accession number: JQ_663444) was cloned and characterized. Amino acid sequence alignment showed siltCAT shared relatively high conservation with other insect, especially the conserved residues which defined heme and NADPH orientation. Expression pattern analysis showed that siltCAT mRNA was mainly expressed in the fat body, midgut, cuticle and malpighian tube, and as well as over last instar larvae, pupa and adult stages. RNA interference was used to silence CAT gene in SL-1 cells and the fourth-instar stage of S. litura larvae respectively. Our results provided evidence that CAT knockdown induced ROS generation, cell cycle arrest and apoptosis in SL-1 cells. It also confirmed the decrease in survival rate because of increased ROS production in experimental groups injected with double-stranded RNA of CAT (dsCAT). This study implied that ROS scavenging by CAT is important for S. litura survival. PMID:23555693

Ecstasy induces reactive oxygen species, kidney water absorption and rhabdomyolysis in normal rats. Effect of N-acetylcysteine and Allopurinol in oxidative stress and muscle fiber damage

PubMed Central

de Bragança, Ana C.; Moreau, Regina L. M.; de Brito, Thales; Shimizu, Maria H. M.; Canale, Daniele; de Jesus, Denise A.; Silva, Ana M. G.; Gois, Pedro H.; Seguro, Antonio C.

2017-01-01

Background Ecstasy (Ec) use produces hyperthermia, excessive sweating, intense thirst, an inappropriate antidiuretic hormone secretion (SIADH) and a multisystemic toxicity due to oxidative stress (OS). Intense thirst induces high intake of pure water, which associated with SIADH, usually develops into acute hyponatremia (Hn). As Hn is induced rapidly, experiments to check if Ec acted directly on the Inner Medullary Collecting Ducts (IMCD) of rats were conducted. Rhabdomyolysis and OS were also studied because Ec is known to induce Reactive Oxygen Species (ROS) and tissue damage. To decrease OS, the antioxidant inhibitors N-acetylcysteine (NAC) and Allopurinol (Allo) were used. Methods Rats were maintained on a lithium (Li) diet to block the Vasopressin action before Ec innoculation. AQP2 (Aquaporin 2), ENaC (Epitheliun Sodium Channel) and NKCC2 (Sodium, Potassium, 2 Chloride) expression were determined by Western Blot in isolated IMCDs. The TBARS (thiobarbituric acid reactive substances) and GSH (reduced form of Glutathione) were determined in the Ec group (6 rats injected with Ec-10mg/kg), in Ec+NAC groups (NAC 100mg/Kg/bw i.p.) and in Allo+Ec groups (Allo 50mg/Kg/i.p.). Results Enhanced AQP2 expression revealed that Ec increased water transporter expression, decreased by Li diet, but the expression of the tubular transporters did not change. The Ec, Ec+NAC and Allo+Ec results showed that Ec increased TBARS and decreased GSH, showing evidence of ROS occurrence, which was protected by NAC and Allo. Rhabdomyolysis was only protected by Allo. Conclusion Results showed that Ec induced an increase in AQP2 expression, evidencing another mechanism that might contribute to cause rapid hyponatremia. In addition, they showed that NAC and Allo protected against OS, but only Allo decreased rhabdomyolysis and hyperthermia. PMID:28678861

Thiol-Based Redox Switches and Gene Regulation

PubMed Central

2011-01-01

Abstract Cysteine is notable among the universal, proteinogenic amino acids for its facile redox chemistry. Cysteine thiolates are readily modified by reactive oxygen species (ROS), reactive electrophilic species (RES), and reactive nitrogen species (RNS). Although thiol switches are commonly triggered by disulfide bond formation, they can also be controlled by S-thiolation, S-alkylation, or modification by RNS. Thiol-based switches are common in both prokaryotic and eukaryotic organisms and activate functions that detoxify reactive species and restore thiol homeostasis while repressing functions that would be deleterious if expressed under oxidizing conditions. Here, we provide an overview of the best-understood examples of thiol-based redox switches that affect gene expression. Intra- or intermolecular disulfide bond formation serves as a direct regulatory switch for several bacterial transcription factors (OxyR, OhrR/2-Cys, Spx, YodB, CrtJ, and CprK) and indirectly regulates others (the RsrA anti-σ factor and RegB sensory histidine kinase). In eukaryotes, thiol-based switches control the yeast Yap1p transcription factor, the Nrf2/Keap1 electrophile and oxidative stress response, and the Chlamydomonas NAB1 translational repressor. Collectively, these regulators reveal a remarkable range of chemical modifications exploited by Cys residues to effect changes in gene expression. Antioxid. Redox Signal. 14, 1049—1063. PMID:20626317

Endosomal NOX2 oxidase exacerbates virus pathogenicity and is a target for antiviral therapy.

PubMed

To, Eunice E; Vlahos, Ross; Luong, Raymond; Halls, Michelle L; Reading, Patrick C; King, Paul T; Chan, Christopher; Drummond, Grant R; Sobey, Christopher G; Broughton, Brad R S; Starkey, Malcolm R; van der Sluis, Renee; Lewin, Sharon R; Bozinovski, Steven; O'Neill, Luke A J; Quach, Tim; Porter, Christopher J H; Brooks, Doug A; O'Leary, John J; Selemidis, Stavros

2017-07-12

The imminent threat of viral epidemics and pandemics dictates a need for therapeutic approaches that target viral pathology irrespective of the infecting strain. Reactive oxygen species are ancient processes that protect plants, fungi and animals against invading pathogens including bacteria. However, in mammals reactive oxygen species production paradoxically promotes virus pathogenicity by mechanisms not yet defined. Here we identify that the primary enzymatic source of reactive oxygen species, NOX2 oxidase, is activated by single stranded RNA and DNA viruses in endocytic compartments resulting in endosomal hydrogen peroxide generation, which suppresses antiviral and humoral signaling networks via modification of a unique, highly conserved cysteine residue (Cys98) on Toll-like receptor-7. Accordingly, targeted inhibition of endosomal reactive oxygen species production abrogates influenza A virus pathogenicity. We conclude that endosomal reactive oxygen species promote fundamental molecular mechanisms of viral pathogenicity, and the specific targeting of this pathogenic process with endosomal-targeted reactive oxygen species inhibitors has implications for the treatment of viral disease.Production of reactive oxygen species is an ancient antimicrobial mechanism, but its role in antiviral defense in mammals is unclear. Here, To et al. show that virus infection activates endosomal NOX2 oxidase and restricts TLR7 signaling, and that an endosomal NOX2 inhibitor decreases viral pathogenicity.

High glucose-induced excessive reactive oxygen species promote apoptosis through mitochondrial damage in rat cartilage endplate cells.

PubMed

Jiang, Zengxin; Lu, Wei; Zeng, Qingmin; Li, Defang; Ding, Lei; Wu, Jingping

2018-04-16

Diabetes mellitus (DM) is an important factor in intervertebral disc degeneration (IDD). Apoptosis of cartilage endplate (CEP) cells is one of the initiators of IDD. However, the effects of high glucose on CEP cells are still unknown. Therefore, we conducted the present study to evaluate the effects of high glucose on CEP cells and to identify the mechanisms of those effects. Rat CEP cells were isolated and cultured in 10% foetal bovine serum (FBS, normal control) or high-glucose medium (10% FBS + 0.1 M glucose or 10% FBS + 0.2 M glucose, experimental conditions) for 1 or 3 days. In addition, CEP cells were treated with 0.2 M glucose for 3 days in the presence or absence of alpha-lipoic acid (ALA, 0.15 M). Flow cytometry was performed to identify and quantify the degree of apoptosis. The expression of reactive oxygen species (ROS) was assessed by flow cytometry, and mitochondrial damage (mitochondrial membrane potential) was assessed by fluorescence microscopy. Furthermore, the expression levels of cleaved caspase-3, cleaved caspase-9, Bcl-2, Bax, and cytochrome c were evaluated by Western blotting. High glucose significantly increased apoptosis and ROS accumulation in CEP cells in a dose- and time-dependent manner. Meanwhile, a disrupted mitochondrial membrane potential was detected in rat CEP cells cultured in the two high glucose concentrations. Incubating in high glucose enhanced the expression levels of cleaved caspase-3, cleaved caspase-9, Bax, and cytochrome c but decreased the level of the anti-apoptotic protein Bcl-2. ALA inhibited the expression of cleaved caspase-3, cleaved caspase-9, Bax, and cytochrome c but enhanced the expression of Bcl-2. ALA also prevented disruption of the mitochondrial membrane potential in CEP cells. This study demonstrates that high glucose-induced excessive reactive oxygen species promote mitochondrial damage, thus causing apoptosis in rat CEP cells in a dose- and time-dependent manner. ALA could prevent mitochondrial damage and apoptosis caused by high glucose in CEP cells. The results suggest that appropriate blood glucose control may be the key to preventing IDD in diabetic patients. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Serum concentrations of the derivatives of reactive oxygen metabolites (d-ROMs) in dogs with leishmaniosis.

PubMed

Paltrinieri, Saverio; Ravicini, Sara; Rossi, Gabriele; Roura, Xavier

2010-12-01

Leishmania infantum interferes with the oxidative metabolism of phagocytes. In order to assess whether derivatives of reactive oxygen metabolites (d-ROMs) decrease due to infection or increase due to inflammation, d-ROMs were measured in serum collected from control dogs (Group 1; n = 12), from dogs seropositive for Leishmania either symptomatic (Group 2; n = 27) or not (Group 3; n = 14), and from dogs with other diseases (Group 4; n = 16). The concentrations of d-ROMs in the four groups, expressed in Carratelli Units (U CARR) were, respectively, 75.4 ± 39.5 (median, 81.6), 108.2 ± 96.3 (73.4), 73.5 ± 62.2 (62.0), 127.7 ± 97.3 (94.3). There were no significant differences between groups, but dogs with values higher than the reference interval were found, mostly in Groups 2 and 4 (which had serum C-reactive protein levels consistent with inflammation), whilst low values were occasionally found in Groups 2 and 3. Inflammation may mask decreases in d-ROMs induced by Leishmania infection. Copyright © 2009 Elsevier Ltd. All rights reserved.

The Expression of Fn14 via Mechanical Stress-activated JNK Contributes to Apoptosis Induction in Osteoblasts*

PubMed Central

Matsui, Hiroyuki; Fukuno, Naoto; Kanda, Yoshiaki; Kantoh, Yusuke; Chida, Toko; Nagaura, Yuko; Suzuki, Osamu; Nishitoh, Hideki; Takeda, Kohsuke; Ichijo, Hidenori; Sawada, Yasuhiro; Sasaki, Keiichi; Kobayashi, Takayasu; Tamura, Shinri

2014-01-01

Bone mass is maintained by the balance between the activities of bone-forming osteoblasts and bone-resorbing osteoclasts. It is well known that adequate mechanical stress is essential for the maintenance of bone mass, whereas excess mechanical stress induces bone resorption. However, it has not been clarified how osteoblasts respond to different magnitudes of mechanical stress. Here we report that large-magnitude (12%) cyclic stretch induced Ca2+ influx, which activated reactive oxygen species generation in MC3T3-E1 osteoblasts. Reactive oxygen species then activated the ASK1-JNK/p38 pathways. The activated JNK led to transiently enhanced expression of FGF-inducible 14 (Fn14, a member of the TNF receptor superfamily) gene. Cells with enhanced expression of Fn14 subsequently acquired sensitivity to the ligand of Fn14, TNF-related weak inducer of apoptosis, and underwent apoptosis. On the other hand, the ASK1-p38 pathway induced expression of the monocyte chemoattractant protein 3 (MCP-3) gene, which promoted chemotaxis of preosteoclasts. In contrast, the ERK pathway was activated by small-magnitude stretching (1%) and induced expression of two osteogenic genes, collagen Ia (Col1a) and osteopontin (OPN). Moreover, activated JNK suppressed Col1a and OPN induction in large-magnitude mechanical stretch-loaded cells. The enhanced expression of Fn14 and MCP-3 by 12% stretch and the enhanced expression of Col1a and OPN by 1% stretch were also observed in mouse primary osteoblasts. These results suggest that differences in the response of osteoblasts to varying magnitudes of mechanical stress play a key role in switching the mode of bone metabolism between formation and resorption. PMID:24446436

Dopamine treatment attenuates acute kidney injury in a rat model of deep hypothermia and rewarming - The role of renal H2S-producing enzymes.

PubMed

Dugbartey, George J; Talaei, Fatemeh; Houwertjes, Martin C; Goris, Maaike; Epema, Anne H; Bouma, Hjalmar R; Henning, Robert H

2015-12-15

Hypothermia and rewarming produces organ injury through the production of reactive oxygen species. We previously found that dopamine prevents hypothermia and rewarming-induced apoptosis in cultured cells through increased expression of the H2S-producing enzyme cystathionine β-Synthase (CBS). Here, we investigate whether dopamine protects the kidney in deep body cooling and explore the role of H2S-producing enzymes in an in vivo rat model of deep hypothermia and rewarming. In anesthetized Wistar rats, body temperature was decreased to 15°C for 3h, followed by rewarming for 1h. Rats (n≥5 per group) were treated throughout the procedure with vehicle or dopamine infusion, and in the presence or absence of a non-specific inhibitor of H2S-producing enzymes, amino-oxyacetic acid (AOAA). Kidney damage and renal expression of three H2S-producing enzymes (CBS, CSE and 3-MST) was quantified and serum H2S level measured. Hypothermia and rewarming induced renal damage, evidenced by increased serum creatinine, renal reactive oxygen species production, KIM-1 expression and influx of immune cells, which was accompanied by substantially lowered renal expression of CBS, CSE, and 3-MST and lowered serum H2S levels. Infusion of dopamine fully attenuated renal damage and maintained expression of H2S-producing enzymes, while normalizing serum H2S. AOAA further decreased the expression of H2S-producing enzymes and serum H2S level, and aggravated renal damage. Hence, dopamine preserves renal integrity during deep hypothermia and rewarming likely by maintaining the expression of renal H2S-producing enzymes and serum H2S. Copyright © 2015 Elsevier B.V. All rights reserved.

[The level of superoxide dismutase expression in primary and metastatic colorectal cancer cells in hypoxia and tissue normoxia].

PubMed

Skrzycki, Michał; Czeczot, Hanna; Chrzanowska, Alicja; Otto-Ślusarczyk, Dagmara

2015-11-01

Superoxide oxidase (SOD) is a key antioxidant enzyme protecting cells against oxidative stress, which might induce cancerogenesis. In tumor cells SOD influences the level of the reactive oxygen species (ROS) allowing for survival and proliferation. High rate of cells proliferation in tumor leads to their temporary hypoxia due to lower rate of angiogenesis. Therefore during tumor development, cancer cells function in conditions of hypoxia or tissue normoxia. The aim of study was to evaluate of SOD isoenzymes (SOD1 and SOD2) expression level in cell lines of primary (SW 480) and metastatic (SW 620) colorectal cancer, cultured in hypoxia (1% oxygen), tissue normoxia (10% oxygen), and atmospheric normoxia (21% oxygen). Cells were cultured in MEM medium in different oxygen concentrations (1%, 10%, 21%) in hypoxic chamber with oxygenation regulator. The number of living cells in lines SW 480 and 620 was determined by trypan blue method. Expression of SOD1 and SOD2 at the mRNA level was determined by RT-PCR and PCR. In both studied cell lines (SW 480 and SW 620), the number of living cells (viability) was increased in hypoxia and atmospheric normoxia. The expression level of SOD1 and SOD2 in studied cell lines was different. The lowest level of expression of both SOD isoenzymes was observed in hypoxia. In conditions of atmospheric normoxia the expression level of SOD1 in SW480 cell line was increased, and similar in SW620 cell line comparing to tissue normoxia. Whereas the SOD2 expression level in atmospheric normoxia conditions in both cell lines was significantly increased. Observed differences were statistically significant (p ≤ 0,05). The profile of expression of SOD1 and SOD2 in cell lines SW480 and SW620 indicates differentiated response of tumor cells depending on access to oxygen. Low level of SOD isoenzymes expression in SW480 and SW620 cells in hypoxia indicates decreased production of ROS. Differences of SOD isoenzymes expression level in tissue normoxia indicate their compensatory action, allowing to maintain the balance between O₂- removal and H₂O₂production in studied tumor cells. In atmospheric normoxia conditions increased expression level of SOD1 and SOD2 observed in studied cell lines points to oxidative stress. © 2015 MEDPRESS.

Increased Interleukin-23 in Hashimoto's Thyroiditis Disease Induces Autophagy Suppression and Reactive Oxygen Species Accumulation.

PubMed

Zheng, Tingting; Xu, Chengcheng; Mao, Chaoming; Mou, Xiao; Wu, Fei; Wang, Xuefeng; Bu, Ling; Zhou, Yuepeng; Luo, Xuan; Lu, Qingyan; Liu, Hongli; Yuan, Guoyue; Wang, Shengjun; Chen, Deyu; Xiao, Yichuan

2018-01-01

Hashimoto's thyroiditis (HT) represents the most common organ-specific autoimmune disease. Inflammatory factors and reactive oxygen species (ROS) play detrimental roles during the pathogenesis of HT. In this study, we found that thyroid follicular cells (TFCs) from HT patients expressed an elevated level of interleukin-23 (IL-23), which contributed to autophagy suppression and ROS accumulation. Additionally, IL-23-induced autophagy suppression and ROS accumulation in human TFCs was attributed to AKT/mTOR/NF-κB signaling pathway activation. Inhibition of either IL-23 by a specific neutralization antibody, or mTOR by rapamycin, or NF-κB by IKK-16, significantly reversed the autophagy suppression and ROS accumulation. These results demonstrate a key role for IL-23 in HT pathogenesis and provide a potential therapeutic strategy against IL-23 or its signaling pathway in HT.

Increased Interleukin-23 in Hashimoto’s Thyroiditis Disease Induces Autophagy Suppression and Reactive Oxygen Species Accumulation

PubMed Central

Zheng, Tingting; Xu, Chengcheng; Mao, Chaoming; Mou, Xiao; Wu, Fei; Wang, Xuefeng; Bu, Ling; Zhou, Yuepeng; Luo, Xuan; Lu, Qingyan; Liu, Hongli; Yuan, Guoyue; Wang, Shengjun; Chen, Deyu; Xiao, Yichuan

2018-01-01

Hashimoto’s thyroiditis (HT) represents the most common organ-specific autoimmune disease. Inflammatory factors and reactive oxygen species (ROS) play detrimental roles during the pathogenesis of HT. In this study, we found that thyroid follicular cells (TFCs) from HT patients expressed an elevated level of interleukin-23 (IL-23), which contributed to autophagy suppression and ROS accumulation. Additionally, IL-23-induced autophagy suppression and ROS accumulation in human TFCs was attributed to AKT/mTOR/NF-κB signaling pathway activation. Inhibition of either IL-23 by a specific neutralization antibody, or mTOR by rapamycin, or NF-κB by IKK-16, significantly reversed the autophagy suppression and ROS accumulation. These results demonstrate a key role for IL-23 in HT pathogenesis and provide a potential therapeutic strategy against IL-23 or its signaling pathway in HT. PMID:29434604

Mitochondrial Dysfunction in Chemotherapy-Induced Peripheral Neuropathy (CIPN)

PubMed Central

Canta, Annalisa; Pozzi, Eleonora; Carozzi, Valentina Alda

2015-01-01

The mitochondrial dysfunction has a critical role in several disorders including chemotherapy-induced peripheral neuropathies (CIPN). This is due to a related dysregulation of pathways involving calcium signalling, reactive oxygen species and apoptosis. Vincristine is able to affect calcium movement through the Dorsal Root Ganglia (DRG) neuronal mitochondrial membrane, altering its homeostasis and leading to abnormal neuronal excitability. Paclitaxel induces the opening of the mitochondrial permeability transition pore in axons followed by mitochondrial membrane potential loss, increased reactive oxygen species generation, ATP level reduction, calcium release and mitochondrial swelling. Cisplatin and oxaliplatin form adducts with mitochondrial DNA producing inhibition of replication, disruption of transcription and morphological abnormalities within mitochondria in DRG neurons, leading to a gradual energy failure. Bortezomib is able to modify mitochondrial calcium homeostasis and mitochondrial respiratory chain. Moreover, the expression of a certain number of genes, including those controlling mitochondrial functions, was altered in patients with bortezomib-induced peripheral neuropathy. PMID:29056658

Reciprocal regulation of TGF-β and reactive oxygen species: A perverse cycle for fibrosis

PubMed Central

Liu, Rui-Ming; Desai, Leena P.

2015-01-01

Transforming growth factor beta (TGF-β) is the most potent pro-fibrogenic cytokine and its expression is increased in almost all of fibrotic diseases. Although signaling through Smad pathway is believed to play a central role in TGF-β's fibrogenesis, emerging evidence indicates that reactive oxygen species (ROS) modulate TGF-β's signaling through different pathways including Smad pathway. TGF-β1 increases ROS production and suppresses antioxidant enzymes, leading to a redox imbalance. ROS, in turn, induce/activate TGF-β1 and mediate many of TGF-β's fibrogenic effects, forming a vicious cycle (see graphic flow chart on the right). Here, we review the current knowledge on the feed-forward mechanisms between TGF-β1 and ROS in the development of fibrosis. Therapeutics targeting TGF-β-induced and ROS-dependent cellular signaling represents a novel approach in the treatment of fibrotic disorders. PMID:26496488

siRNA-based Analysis of the Abrogation of the Protective Function of Membrane-associated Catalase of Tumor Cells.

PubMed

Bauer, Georg

2017-02-01

Tumor cells, in contrast to non-malignant cells, show sustained expression of membrane-associated NADPH oxidase-1 and therefore generate extracellular superoxide anions and their dismutation product H 2 O 2 In order to prevent intercellular reactive oxygen species/reactive nitrogen species (ROS/RNS)-dependent apoptosis-inducing signaling, tumor cells need to express membrane-associated catalase that interferes with HOCl and nitric oxide/peroxynitrite signaling. Catalase is attached to tumor cells through the activity of transglutaminase-2 and is prevented from superoxide anion-dependent inhibition through coexpression of membrane-associated superoxide dismutase. Therefore, specific inhibition of membrane-associated catalase should reactivate intercellular ROS/RNS-dependent apoptosis-inducing signaling. These processes are analyzed here through small interfering RNA-mediated knockdown of essential signaling compounds. This allows to establish a rather comprehensive picture of intercellular ROS/RNS signaling that may be instrumental for future therapeutic approaches. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Flaxseed oil increases aortic reactivity to phenylephrine through reactive oxygen species and the cyclooxygenase-2 pathway in rats

PubMed Central

2014-01-01

Background Flaxseed oil has the highest concentration of omega-3 α-linolenic acid, which has been associated with cardiovascular benefit. However, the mechanism underlying the vascular effects induced through flaxseed oil is not well known. Thus, in the present study, we investigated the effects of flaxseed oil on vascular function in isolated rat aortic rings. Methods Wistar rats were treated daily with flaxseed oil or a control (mineral oil) intramuscular (i.m.) for fifteen days. Isolated aortic segments were used to evaluate cyclooxygenase-2 (COX-2) protein expression, superoxide anion levels and vascular reactivity experiments. Results Flaxseed oil treatment increased the vasoconstrictor response of aortic rings to phenylephrine. Endothelium removal increased the response to phenylephrine in aortic segments isolated from both groups, but the effect was smaller in the treated group. L-NAME incubation similarly increased the phenylephrine response in segments from both groups. The TXA2 synthase inhibitor furegrelate, the selective COX-2 inhibitor NS 398, the TP receptor antagonist SQ 29.548, the reactive oxygen species (ROS) scavenger apocynin, the superoxide anion scavengers tiron and the phospholipase A2 inhibitor dexamethasone partially reversed the flaxseed oil-induced increase in reactivity to phenylephrine. Conclusions These findings suggest that flaxseed oil treatment increased vascular reactivity to phenylephrine through an increase in ROS production and COX-2-derived TXA2 production. The results obtained in the present study provide new insight into the effects of flaxseed oil treatment (i.m.) on vascular function. PMID:24993607

Reactive oxygen species modulator 1, a novel protein, combined with carcinoembryonic antigen in differentiating malignant from benign pleural effusion.

PubMed

Chen, Xianmeng; Zhang, Na; Dong, Jiahui; Sun, Gengyun

2017-05-01

The differential diagnosis of malignant pleural effusion and benign pleural effusion remains a clinical problem. Reactive oxygen species modulator 1 is a novel protein overexpressed in various human tumors. The objective of this study was to evaluate the diagnostic value of joint detection of reactive oxygen species modulator 1 and carcinoembryonic antigen in the differential diagnosis of malignant pleural effusion and benign pleural effusion. One hundred two consecutive patients with pleural effusion (including 52 malignant pleural effusion and 50 benign pleural effusion) were registered in this study. Levels of reactive oxygen species modulator 1 and carcinoembryonic antigen were measured by enzyme-linked immunosorbent assay and radioimmunoassay, respectively. Results showed that the concentrations of reactive oxygen species modulator 1 both in pleural fluid and serum of patients with malignant pleural effusion were significantly higher than those of benign pleural effusion (both p < 0.05). The diagnostic sensitivity and specificity of pleural fluid reactive oxygen species modulator 1 were 61.54% and 82.00%, respectively, with the optimized cutoff value of 589.70 pg/mL. However, the diagnostic sensitivity and specificity of serum reactive oxygen species modulator 1 were only 41.38% and 86.21%, respectively, with the cutoff value of 27.22 ng/mL, indicating that serum reactive oxygen species modulator 1 may not be a good option in the differential diagnosis of malignant pleural effusion and benign pleural effusion. The sensitivity and specificity of pleural fluid carcinoembryonic antigen were 69.23% and 88.00%, respectively, at the cutoff value of 3.05 ng/mL, while serum carcinoembryonic antigen were 80.77% and 72.00% at the cutoff value of 2.60 ng/mL. The sensitivity could be raised to 88.17% in parallel detection of plural fluid reactive oxygen species modulator 1 and carcinoembryonic antigen concentration, and the specificity could be improved to 97.84% in serial detection.

ABNORMAL INFLORESCENCE MERISTEM1 Functions in Salicylic Acid Biosynthesis to Maintain Proper Reactive Oxygen Species Levels for Root Meristem Activity in Rice.

PubMed

Xu, Lei; Zhao, Hongyu; Ruan, Wenyuan; Deng, Minjuan; Wang, Fang; Peng, Jinrong; Luo, Jie; Chen, Zhixiang; Yi, Keke

2017-03-01

Root meristem activity determines root growth and root architecture and consequently affects water and nutrient uptake in plants. However, our knowledge about the regulation of root meristem activity in crop plants is very limited. Here, we report the isolation and characterization of a short root mutant in rice ( Oryza sativa ) with reduced root meristem activity. This root growth defect is caused by a mutation in ABNORMAL INFLORESCENCE MERISTEM1 ( AIM1 ), which encodes a 3-hydroxyacyl-CoA dehydrogenase, an enzyme involved in β-oxidation. The reduced root meristem activity of aim1 results from reduced salicylic acid (SA) levels and can be rescued by SA application. Furthermore, reduced SA levels are associated with reduced levels of reactive oxygen species (ROS) in aim1 , likely due to increased expression of redox and ROS-scavenging-related genes, whose increased expression is (at least in part) caused by reduced expression of the SA-inducible transcriptional repressors WRKY62 and WRKY76. Like SA, ROS application substantially increased root length and root meristem activity in aim1 These results suggest that AIM1 is required for root growth in rice due to its critical role in SA biosynthesis: SA maintains root meristem activity through promoting ROS accumulation by inducing the activity of WRKY transcriptional repressors, which repress the expression of redox and ROS-scavenging genes. © 2017 American Society of Plant Biologists. All rights reserved.

The ketogenic diet reverses gene expression patterns and reduces reactive oxygen species levels when used as an adjuvant therapy for glioma.

PubMed

Stafford, Phillip; Abdelwahab, Mohammed G; Kim, Do Young; Preul, Mark C; Rho, Jong M; Scheck, Adrienne C

2010-09-10

Malignant brain tumors affect people of all ages and are the second leading cause of cancer deaths in children. While current treatments are effective and improve survival, there remains a substantial need for more efficacious therapeutic modalities. The ketogenic diet (KD) - a high-fat, low-carbohydrate treatment for medically refractory epilepsy - has been suggested as an alternative strategy to inhibit tumor growth by altering intrinsic metabolism, especially by inducing glycopenia. Here, we examined the effects of an experimental KD on a mouse model of glioma, and compared patterns of gene expression in tumors vs. normal brain from animals fed either a KD or a standard diet. Animals received intracranial injections of bioluminescent GL261-luc cells and tumor growth was followed in vivo. KD treatment significantly reduced the rate of tumor growth and prolonged survival. Further, the KD reduced reactive oxygen species (ROS) production in tumor cells. Gene expression profiling demonstrated that the KD induces an overall reversion to expression patterns seen in non-tumor specimens. Notably, genes involved in modulating ROS levels and oxidative stress were altered, including those encoding cyclooxygenase 2, glutathione peroxidases 3 and 7, and periredoxin 4. Our data demonstrate that the KD improves survivability in our mouse model of glioma, and suggests that the mechanisms accounting for this protective effect likely involve complex alterations in cellular metabolism beyond simply a reduction in glucose.

Minimal influence of G-protein null mutations on ozone-induced changes in gene expression, foliar injury, gas-exchange and peroxidase activity in Arabidopsis thaliana L

USDA-ARS?s Scientific Manuscript database

Ozone uptake by plants leads to an increase in reactive oxygen species (ROS) in the intercellular space of leaves and induces signalling processes reported to involve the membrane-bound heterotrimeric G-protein complex. Therefore, potential G-protein-mediated response mechanisms to ozone were compar...

Female mice lacking p47phox have altered adipose tissue gene expression and are protected against high fat-induced obesity

USDA-ARS?s Scientific Manuscript database

Oxidative stress in the fat and the liver has been linked to the development of obesity and the metabolic syndrome. However, the molecular origin of reactive oxygen species and the role of these in obesity remain areas of active investigation. The NADPH oxidases (NOX) enzymes are a major source of ...

Antioxidant and anti-ageing activities of citrus-based juice mixture.

PubMed

Kim, Dan-Bi; Shin, Gi-Hae; Kim, Jae-Min; Kim, Young-Hyun; Lee, Jin-Ha; Lee, Jong Seok; Song, Hye-Jin; Choe, Soo Young; Park, In-Jae; Cho, Ju-Hyun; Lee, Ok-Hawn

2016-03-01

The production of excessive reactive oxygen species by exposure to oxidative stress and solar radiation are primary factors in skin damage. We examined the effects of a citrus-based juice mixture and its bioactive compounds on antioxidant and anti-ageing activities in human dermal fibroblasts and hairless mice via the regulation of antioxidant enzymes and the mitogen-activated protein kinase pathway. The citrus-based juice mixture reduced H2O2-induced cell damage and intracellular reactive oxygen species production in human dermal fibroblasts. Citrus-based juice mixture pretreatment suppressed the activation of the H2O2-mediated mitogen-activated protein kinase pathway by activating the expression of activator protein 1 and matrix metalloproteinases. Moreover, it increased the expression levels of antioxidant enzymes such as glutathione reductase, catalase and manganese superoxide dismutase. In addition, oral administration of the citrus-based juice mixture decreased skin thickness and wrinkle formation and increased collagen content on an ultraviolet light B-exposed hairless mouse. These results indicate that the citrus-based juice mixture is a potentially healthy beverage for the prevention of oxidative stress-induced premature skin ageing. Copyright © 2015 Elsevier Ltd. All rights reserved.

Reactive Oxygen Species Play a Role in the Infection of the Necrotrophic Fungi, Rhizoctonia solani in Wheat

PubMed Central

Foley, Rhonda C.; Kidd, Brendan N.; Hane, James K.; Anderson, Jonathan P.; Singh, Karam B.

2016-01-01

Rhizoctonia solani is a nectrotrophic fungal pathogen that causes billions of dollars of damage to agriculture worldwide and infects a broad host range including wheat, rice, potato and legumes. In this study we identify wheat genes that are differentially expressed in response to the R. solani isolate, AG8, using microarray technology. A significant number of wheat genes identified in this screen were involved in reactive oxygen species (ROS) production and redox regulation. Levels of ROS species were increased in wheat root tissue following R. solani infection as determined by Nitro Blue Tetrazolium (NBT), 3,3'-diaminobenzidine (DAB) and titanium sulphate measurements. Pathogen/ROS related genes from R. solani were also tested for expression patterns upon wheat infection. TmpL, a R. solani gene homologous to a gene associated with ROS regulation in Alternaria brassicicola, and OAH, a R. solani gene homologous to oxaloacetate acetylhydrolase which has been shown to produce oxalic acid in Sclerotinia sclerotiorum, were highly induced in R. solani when infecting wheat. We speculate that the interplay between the wheat and R. solani ROS generating proteins may be important for determining the outcome of the wheat/R. solani interaction. PMID:27031952

Paroxetine prevents loss of nigrostriatal dopaminergic neurons by inhibiting brain inflammation and oxidative stress in an experimental model of Parkinson's disease.

PubMed

Chung, Young C; Kim, Sang R; Jin, Byung K

2010-07-15

The present study examined whether the antidepressant paroxetine promotes the survival of nigrostriatal dopaminergic (DA) neurons in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of Parkinson's disease. MPTP induced degeneration of nigrostriatal DA neurons and glial activation as visualized by tyrosine hydroxylase, macrophage Ag complex-1, and/or glial fibrillary acidic protein immunoreactivity. Real-time PCR, Western blotting, and immunohistochemistry showed upregulation of proinflammatory cytokines, activation of microglial NADPH oxidase and astroglial myeloperoxidase, and subsequent reactive oxygen species production and oxidative DNA damage in the MPTP-treated substantia nigra. Treatment with paroxetine prevented degeneration of nigrostriatal DA neurons, increased striatal dopamine levels, and improved motor function. This neuroprotection afforded by paroxetine was associated with the suppression of astroglial myeloperoxidase expression and/or NADPH oxidase-derived reactive oxygen species production and reduced expression of proinflammatory cytokines, including IL-1beta, TNF-alpha, and inducible NO synthase, by activated microglia. The present findings show that paroxetine may possess anti-inflammatory properties and inhibit glial activation-mediated oxidative stress, suggesting that paroxetine and its analogues may have therapeutic value in the treatment of aspects of Parkinson's disease related to neuroinflammation.

Phloretin induces cell cycle arrest and apoptosis of human glioblastoma cells through the generation of reactive oxygen species.

PubMed

Liu, Yuanyuan; Fan, Chenghe; Pu, Lv; Wei, Cui; Jin, Haiqiang; Teng, Yuming; Zhao, Mingming; Yu, Albert Cheung Hoi; Jiang, Feng; Shu, Junlong; Li, Fan; Peng, Qing; Kong, Jian; Pan, Bing; Zheng, Lemin; Huang, Yining

2016-06-01

Phloretin, a flavonoid present in various plants, has been reported to exert anticarcinogenic effects. However, the mechanism of its chemo-preventive effect on human glioblastoma cells is not fully understood. This study aimed to investigate the molecular mechanism of phloretin and its associated chemo-preventive effect in human glioblastoma cells. The results indicate that phloretin inhibited cell proliferation by inducing cell cycle arrest at the G0-G1 phase and induced apoptosis of human glioblastoma cells. Phloretin-induced cell cycle arrest was associated with increased expression of p27 and decreased expression of cdk2, cdk4, cdk6, cyclinD and cyclinE. Moreover, the PI3K/AKT/mTOR signaling cascades were suppressed by phloretin in a dose-dependent manner. In addition, phloretin triggered the mitochondrial apoptosis pathway and generated reactive oxygen species (ROS). This was accompanied by the up-regulation of Bax, Bak and c-PARP and the down-regulation of Bcl-2. The antioxidant agents N-acetyl-L-cysteine and glutathione weakened the effect of phloretin on glioblastoma cells. In conclusion, these results demonstrate that phloretin exerts potent chemo-preventive activity in human glioblastoma cells through the generation of ROS.

Azoxystrobin-induced excessive reactive oxygen species (ROS) production and inhibition of photosynthesis in the unicellular green algae Chlorella vulgaris.

PubMed

Liu, Lei; Zhu, Bin; Wang, Gao-Xue

2015-05-01

This study investigated the short-term toxicity of azoxystrobin (AZ), one of strobilurins used as an effective fungicidal agent to control the Asian soybean rust, on aquatic unicellular algae Chlorella vulgaris. The median percentile inhibition concentration (IC₅₀) of AZ for C. vulgaris was found to be 510 μg L(-1). We showed that the algal cells were obviously depressed or shrunk in 300 and 600 μg L(-1) AZ treatments by using the electron microscopy. Furthermore, 19, 75, and 300 μg L(-1) AZ treatments decreased the soluble protein content and chlorophyll concentrations in C. vulgaris and altered the energy-photosynthesis-related mRNA expression levels in 48- and 96-h exposure periods. Simultaneously, our results showed that AZ could increase the total antioxidant capacity (T-AOC) level and compromise superoxide dismutase (SOD), peroxidase (POD), glutathione S transferase (GST), glutathione peroxidase (GPx) activities, and glutathione (GSH) content. These situations might render C. vulgaris more vulnerable to oxidative damage. Overall, the present study indicated that AZ might be toxic to the growth of C. vulgaris, affect energy-photosynthesis-related mRNA expressions, and induce reactive oxygen species (ROS) overproduction in C. vulgaris.

Pneumolysin induces cellular senescence by increasing ROS production and activation of MAPK/NF-κB signal pathway in glial cells.

PubMed

Kwon, Ii-Seul; Kim, Jinwook; Rhee, Dong-Kwon; Kim, Byung-Oh; Pyo, Suhkneung

2017-04-01

Senescence is an irreversible proliferation arrest that is induced by various stress stimuli including genotoxin. Pneumolysin (PLY) is a pathogenicity factor unique to Streptococcus pneumoniae that is important in pneumococcal-induced diseases such as otitis media, meningitis and pneumonia. However, the cell fate response to the toxin is mechanistically unclear. We investigated the effect of PLY on cellular senescence in BV-2 microglial cells. Exposure to PLY resulted in changes in the expression of phospho-p53, p21, p16, pRb and CDK2 and increased the number of senescence associated β-gal positive cells. PLY-treatment also increased PAI-1 expression and cell proliferation arrest in concentration- and time-dependent manners. PLY induced NF-κB activation and phosphorylation of SIRT-1, ERK1/2, JNK, and p38 MAPK. In addition, PLY increased the production of reactive oxygen species. Overall, the results suggest that PLY regulates microglial cellular senescence by enhancing production of reactive oxygen species, activation of MAPK and NF-κB, and phosphorylation of SIRT-1. Copyright © 2017 Elsevier Ltd. All rights reserved.

Reactive Oxygen Species Play a Role in the Infection of the Necrotrophic Fungi, Rhizoctonia solani in Wheat.

PubMed

Foley, Rhonda C; Kidd, Brendan N; Hane, James K; Anderson, Jonathan P; Singh, Karam B

2016-01-01

Rhizoctonia solani is a nectrotrophic fungal pathogen that causes billions of dollars of damage to agriculture worldwide and infects a broad host range including wheat, rice, potato and legumes. In this study we identify wheat genes that are differentially expressed in response to the R. solani isolate, AG8, using microarray technology. A significant number of wheat genes identified in this screen were involved in reactive oxygen species (ROS) production and redox regulation. Levels of ROS species were increased in wheat root tissue following R. solani infection as determined by Nitro Blue Tetrazolium (NBT), 3,3'-diaminobenzidine (DAB) and titanium sulphate measurements. Pathogen/ROS related genes from R. solani were also tested for expression patterns upon wheat infection. TmpL, a R. solani gene homologous to a gene associated with ROS regulation in Alternaria brassicicola, and OAH, a R. solani gene homologous to oxaloacetate acetylhydrolase which has been shown to produce oxalic acid in Sclerotinia sclerotiorum, were highly induced in R. solani when infecting wheat. We speculate that the interplay between the wheat and R. solani ROS generating proteins may be important for determining the outcome of the wheat/R. solani interaction.

Ascorbic acid and reactive oxygen species are involved in the inhibition of seed germination by abscisic acid in rice seeds

PubMed Central

Ye, Nenghui; Zhu, Guohui; Liu, Yinggao; Liu, Rui; Shi, Lu; Jia, Liguo; Zhang, Jianhua

2012-01-01

The antagonism between abscisic acid (ABA) and gibberellin (GA) plays a key role in controlling seed germination, but the mechanism of antagonism during this process is not known. The possible links among ABA, reactive oxygen species (ROS), ascorbic acid (ASC), and GA during rice seed germination were investigated. Unlike in non-seed tissues where ROS production is increased by ABA, ABA reduced ROS production in imbibed rice seeds, especially in the embryo region. Such reduced ROS also led to an inhibition of ASC production. GA accumulation was also suppressed by a reduced ROS and ASC level, which was indicated by the inhibited expression of GA biosynthesis genes, amylase genes, and enzyme activity. Application of exogenous ASC can partially rescue seed germination from ABA treatment. Production of ASC, which acts as a substrate in GA biosynthesis, was significantly inhibited by lycorine which thus suppressed the accumulation of GA. Consequently, expression of GA biosynthesis genes was suppressed by the low levels of ROS and ASC in ABA-treated seeds. It can be concluded that ABA regulates seed germination in multiple dimensions. ROS and ASC are involved in its inhibition of GA biosynthesis. PMID:22200664

Measurement of Reactive Oxygen Species, Reactive Nitrogen Species, and Redox-Dependent Signaling in the Cardiovascular System

PubMed Central

Griendling, Kathy K.; Touyz, Rhian M.; Zweier, Jay L.; Dikalov, Sergey; Chilian, William; Chen, Yeong-Renn; Harrison, David G.; Bhatnagar, Aruni

2017-01-01

Reactive oxygen species and reactive nitrogen species are biological molecules that play important roles in cardiovascular physiology and contribute to disease initiation, progression, and severity. Because of their ephemeral nature and rapid reactivity, these species are difficult to measure directly with high accuracy and precision. In this statement, we review current methods for measuring these species and the secondary products they generate and suggest approaches for measuring redox status, oxidative stress, and the production of individual reactive oxygen and nitrogen species. We discuss the strengths and limitations of different methods and the relative specificity and suitability of these methods for measuring the concentrations of reactive oxygen and reactive nitrogen species in cells, tissues, and biological fluids. We provide specific guidelines, through expert opinion, for choosing reliable and reproducible assays for different experimental and clinical situations. These guidelines are intended to help investigators and clinical researchers avoid experimental error and ensure high-quality measurements of these important biological species. PMID:27418630

6-Shogaol enhances renal carcinoma Caki cells to TRAIL-induced apoptosis through reactive oxygen species-mediated cytochrome c release and down-regulation of c-FLIP(L) expression.

PubMed

Han, Min Ae; Woo, Seon Min; Min, Kyoung-jin; Kim, Shin; Park, Jong-Wook; Kim, Dong Eun; Kim, Sang Hyun; Choi, Yung Hyun; Kwon, Taeg Kyu

2015-02-25

6-Shogaol, a potent bioactive compound in ginger (Zingiber officinale Roscoe), has been reported for anti-inflammatory and anti-cancer activity. In this study, we investigated the effect of 6-shogaol to enhance tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis. The combined treatment with 6-shogaol and TRAIL markedly induces apoptosis in various cancer cells (renal carcinoma Caki cells, breast carcinoma MDA-MB-231 cells and glioma U118MG cells), but not in normal mesangial cells and normal mouse kidney cells. 6-Shogaol reduced the mitochondrial membrane potential (MMP) and released cytochrome c from mitochondria to cytosol via Bax activation. Furthermore, we found that 6-shogaol induced down-regulation of c-FLIP(L) expression at the post-translational levels and the overexpression of c-FLIP(L) markedly inhibited 6-shogaol plus TRAIL-induced apoptosis. Moreover, 6-shogaol increased reactive oxygen species (ROS) production in Caki cells. Pretreatment with ROS scavengers attenuated 6-shogaol plus TRAIL-induced apoptosis through inhibition of MMP reduction and down-regulation of c-FLIP(L) expression. In addition, 6-gingerol, another phenolic alkanone isolated from ginger, did not enhance TRAIL-induced apoptosis and down-regulate c-FLIP(L) expression. Taken together, our results demonstrated that 6-shogaol enhances TRAIL-mediated apoptosis in renal carcinoma Caki cells via ROS-mediated cytochrome c release and down-regulation of c-FLIP(L) expression. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Reactive oxygen species regulate programmed cell death progress of endosperm in winter wheat (Triticum aestivum L.) under waterlogging.

PubMed

Cheng, Xiang-Xu; Yu, Min; Zhang, Nan; Zhou, Zhu-Qing; Xu, Qiu-Tao; Mei, Fang-Zhu; Qu, Liang-Huan

2016-03-01

Previous studies have proved that waterlogging stress accelerates the programmed cell death (PCD) progress of wheat endosperm cells. A highly waterlogging-tolerant wheat cultivar Hua 8 and a waterlogging susceptible wheat cultivar Hua 9 were treated with different waterlogging durations, and then, dynamic changes of reactive oxygen species (ROS), gene expressions, and activities of antioxidant enzymes in endosperm cells were detected. The accumulation of ROS increased considerably after 7 days of waterlogging treatment (7 DWT) and 12 DWT in both cultivars compared with control group (under non-waterlogged conditions), culminated at 12 DAF (days after flowering) and reduced hereafter. Waterlogging resulted in a great increase of H2O2 and O2 (-) in plasma membranes, cell walls, mitochondrias, and intercellular spaces with ultracytochemical localization. Moreover, the deformation and rupture of cytomembranes as well as the swelling and distortion of mitochondria were obvious. Under waterlogging treatment conditions, catalase (CAT) gene expression increased in endosperm of Hua 8 but activity decreased. In addition, Mn superoxide dismutase (MnSOD) gene expression and superoxide dismutase (SOD) activity increased. Compared with Hua 8, both CAT, MnSOD gene expressions and CAT, SOD activities decreased in Hua 9. Moreover, ascorbic acid and mannitol relieve the intensifying of PCD processes in Hua 8 endosperm cells induced by waterlogging. These results indicate that ROS have important roles in the PCD of endosperm cells, the changes both CAT, MnSOD gene expressions and CAT, SOD activities directly affected the accumulation of ROS in two different wheat cultivars under waterlogging, ultimately led to the PCD acceleration of endosperm.

Emodin Inhibits Homocysteine-Induced C-Reactive Protein Generation in Vascular Smooth Muscle Cells by Regulating PPARγ Expression and ROS-ERK1/2/p38 Signal Pathway

PubMed Central

Pang, Xiaoming; Liu, Juntian; Li, Yuxia; Zhao, Jingjing; Zhang, Xiaolu

2015-01-01

Atherosclerosis is an inflammatory disease. As an inflammatory molecule, C-reactive protein (CRP) plays a direct role in atherogenesis. It is known that the elevated plasma homocysteine (Hcy) level is an independent risk factor for atherosclerosis. We previously reported that Hcy produces a pro-inflammatory effect by inducing CRP expression in vascular smooth muscle cells (VSMCs). In the present study, we observed effect of emodin on Hcy-induced CRP expression in rat VSMCs and molecular mechanisms. The in vitro results showed that pretreatment of VSMCs with emodin inhibited Hcy-induced mRNA and protein expression of CRP in a concentration-dependent manner. The in vivo experiments displayed that emodin not only inhibited CRP expression in the vessel walls in mRNA and protein levels, but also reduced the circulating CRP level in hyperhomocysteinemic rats. Further study revealed that emodin diminished Hcy-stimulated generation of reactive oxygen species (ROS), attenuated Hcy-activated phosphorylation of ERK1/2 and p38, and upregulated Hcy-inhibited expression of peroxisome proliferator-activated receptor gamma (PPARγ) in VSMCs. These demonstrate that emodin is able to inhibit Hcy-induced CRP generation in VSMCs, which is related to interfering with ROS-ERK1/2/p38 signal pathway and upregulating PPARγ expression. The present study provides new evidence for the anti-inflammatory and anti-atherosclerotic effects of emodin. PMID:26131983

Oxidative Stressors Modify the Response of Streptococcus mutans to Its Competence Signal Peptides

PubMed Central

De Furio, Matthew; Ahn, Sang Joon

2017-01-01

ABSTRACT The dental caries pathogen Streptococcus mutans is continually exposed to several types of stress in the oral biofilm environment. Oxidative stress generated by reactive oxygen species has a major impact on the establishment, persistence, and virulence of S. mutans. Here, we combined fluorescent reporter-promoter fusions with single-cell imaging to study the effects of reactive oxygen species on activation of genetic competence in S. mutans. Exposure to paraquat, which generates superoxide anion, produced a qualitatively different effect on activation of expression of the gene for the master competence regulator, ComX, than did treatment with hydrogen peroxide (H2O2), which can yield hydroxyl radical. Paraquat suppressed peptide-mediated induction of comX in a progressive and cumulative fashion, whereas the response to H2O2 displayed a strong threshold behavior. Low concentrations of H2O2 had little effect on induction of comX or the bacteriocin gene cipB, but expression of these genes declined sharply if extracellular H2O2 exceeded a threshold concentration. These effects were not due to decreased reporter gene fluorescence. Two different threshold concentrations were observed in the response to H2O2, depending on the gene promoter that was analyzed and the pathway by which the competence regulon was stimulated. The results show that paraquat and H2O2 affect the S. mutans competence signaling pathway differently, and that some portions of the competence signaling pathway are more sensitive to oxidative stress than others. IMPORTANCE Streptococcus mutans inhabits the oral biofilm, where it plays an important role in the development of dental caries. Environmental stresses such as oxidative stress influence the growth of S. mutans and its important virulence-associated behaviors, such as genetic competence. S. mutans competence development is a complex behavior that involves two different signaling peptides and can exhibit cell-to-cell heterogeneity. Although oxidative stress is known to influence S. mutans competence, it is not understood how oxidative stress interacts with the peptide signaling or affects heterogeneity. In this study, we used fluorescent reporters to probe the effect of reactive oxygen species on competence signaling at the single-cell level. Our data show that different reactive oxygen species have different effects on S. mutans competence, and that some portions of the signaling pathway are more acutely sensitive to oxidative stress than others. PMID:28887419

Cytotoxic and Antitumor Activity of Sulforaphane: The Role of Reactive Oxygen Species

PubMed Central

Sestili, Piero

2015-01-01

According to recent estimates, cancer continues to remain the second leading cause of death and is becoming the leading one in old age. Failure and high systemic toxicity of conventional cancer therapies have accelerated the identification and development of innovative preventive as well as therapeutic strategies to contrast cancer-associated morbidity and mortality. In recent years, increasing body of in vitro and in vivo studies has underscored the cancer preventive and therapeutic efficacy of the isothiocyanate sulforaphane. In this review article, we highlight that sulforaphane cytotoxicity derives from complex, concurring, and multiple mechanisms, among which the generation of reactive oxygen species has been identified as playing a central role in promoting apoptosis and autophagy of target cells. We also discuss the site and the mechanism of reactive oxygen species' formation by sulforaphane, the toxicological relevance of sulforaphane-formed reactive oxygen species, and the death pathways triggered by sulforaphane-derived reactive oxygen species. PMID:26185755

Reactive Oxygen Species in Cardiovascular Disease

PubMed Central

Sugamura, Koichi; Keaney, John F.

2011-01-01

Based on the ‘free-radical theory’ of disease, researchers have been trying to elucidate the role of oxidative stress from free radicals in cardiovascular disease. Considerable data indicate that ROS and oxidative stress are important features of cardiovascular diseases including atherosclerosis, hypertension, and congestive heart failure. However, blanket strategies with antioxidants to ameliorate cardiovascular disease have not generally yielded favorable results. However, our understanding or reactive oxygen species has evolved to the point that we now realize these species have important roles in physiology as well as pathophysiology. Thus, it is overly simplistic to assume a general antioxidant strategy will yield specific effects on cardiovascular disease. Indeed, there are several sources of reactive oxygen species that are known to be active in the cardiovascular system. This review will address our understanding of reactive oxygen species sources in cardiovascular disease and both animal and human data defining how reactive oxygen species contribute to physiology and pathology. PMID:21627987

Steap4 Plays a Critical Role in Osteoclastogenesis in Vitro by Regulating Cellular Iron/Reactive Oxygen Species (ROS) Levels and cAMP Response Element-binding Protein (CREB) Activation*

PubMed Central

Zhou, Jian; Ye, Shiqiao; Fujiwara, Toshifumi; Manolagas, Stavros C.; Zhao, Haibo

2013-01-01

Iron is essential for osteoclast differentiation, and iron overload in a variety of hematologic diseases is associated with excessive bone resorption. Iron uptake by osteoclast precursors via the transferrin cycle increases mitochondrial biogenesis, reactive oxygen species production, and activation of cAMP response element-binding protein, a critical transcription factor downstream of receptor activator of NF-κB-ligand-induced calcium signaling. These changes are required for the differentiation of osteoclast precursors to mature bone-resorbing osteoclasts. However, the molecular mechanisms regulating cellular iron metabolism in osteoclasts remain largely unknown. In this report, we provide evidence that Steap4, a member of the six-transmembrane epithelial antigen of prostate (Steap) family proteins, is an endosomal ferrireductase with a critical role in cellular iron utilization in osteoclasts. Specifically, we show that Steap4 is the only Steap family protein that is up-regulated during osteoclast differentiation. Knocking down Steap4 expression in vitro by lentivirus-mediated short hairpin RNAs inhibits osteoclast formation and decreases cellular ferrous iron, reactive oxygen species, and the activation of cAMP response element-binding protein. These results demonstrate that Steap4 is a critical enzyme for cellular iron uptake and utilization in osteoclasts and, thus, indispensable for osteoclast development and function. PMID:23990467

The role of Hibiscus sabdariffa L. (Roselle) in maintenance of ex vivo murine bone marrow-derived hematopoietic stem cells.

PubMed

Abdul Hamid, Zariyantey; Lin Lin, Winnie Hii; Abdalla, Basma Jibril; Bee Yuen, Ong; Latif, Elda Surhaida; Mohamed, Jamaludin; Rajab, Nor Fadilah; Paik Wah, Chow; Wak Harto, Muhd Khairul Akmal; Budin, Siti Balkis

2014-01-01

Hematopoietic stem cells- (HSCs-) based therapy requires ex vivo expansion of HSCs prior to therapeutic use. However, ex vivo culture was reported to promote excessive production of reactive oxygen species (ROS), exposing HSCs to oxidative damage. Efforts to overcome this limitation include the use of antioxidants. In this study, the role of Hibiscus sabdariffa L. (Roselle) in maintenance of cultured murine bone marrow-derived HSCs was investigated. Aqueous extract of Roselle was added at varying concentrations (0-1000 ng/mL) for 24 hours to the freshly isolated murine bone marrow cells (BMCs) cultures. Effects of Roselle on cell viability, reactive oxygen species (ROS) production, glutathione (GSH) level, superoxide dismutase (SOD) activity, and DNA damage were investigated. Roselle enhanced the survival (P < 0.05) of BMCs at 500 and 1000 ng/mL, increased survival of Sca-1(+) cells (HSCs) at 500 ng/mL, and maintained HSCs phenotype as shown from nonremarkable changes of surface marker antigen (Sca-1) expression in all experimental groups. Roselle increased (P < 0.05) the GSH level and SOD activity but the level of reactive oxygen species (ROS) was unaffected. Moreover, Roselle showed significant cellular genoprotective potency against H2O2-induced DNA damage. Conclusively, Roselle shows novel property as potential supplement and genoprotectant against oxidative damage to cultured HSCs.

Cardiomyocyte hypertrophy induced by Endonuclease G deficiency requires reactive oxygen radicals accumulation and is inhibitable by the micropeptide humanin.

PubMed

Blasco, Natividad; Cámara, Yolanda; Núñez, Estefanía; Beà, Aida; Barés, Gisel; Forné, Carles; Ruíz-Meana, Marisol; Girón, Cristina; Barba, Ignasi; García-Arumí, Elena; García-Dorado, David; Vázquez, Jesús; Martí, Ramon; Llovera, Marta; Sanchis, Daniel

2018-06-01

The endonuclease G gene (Endog), which codes for a mitochondrial nuclease, was identified as a determinant of cardiac hypertrophy. How ENDOG controls cardiomyocyte growth is still unknown. Thus, we aimed at finding the link between ENDOG activity and cardiomyocyte growth. Endog deficiency induced reactive oxygen species (ROS) accumulation and abnormal growth in neonatal rodent cardiomyocytes, altering the AKT-GSK3β and Class-II histone deacethylases (HDAC) signal transduction pathways. These effects were blocked by ROS scavengers. Lack of ENDOG reduced mitochondrial DNA (mtDNA) replication independently of ROS accumulation. Because mtDNA encodes several subunits of the mitochondrial electron transport chain, whose activity is an important source of cellular ROS, we investigated whether Endog deficiency compromised the expression and activity of the respiratory chain complexes but found no changes in these parameters nor in ATP content. MtDNA also codes for humanin, a micropeptide with possible metabolic functions. Nanomolar concentrations of synthetic humanin restored normal ROS levels and cell size in Endog-deficient cardiomyocytes. These results support the involvement of redox signaling in the control of cardiomyocyte growth by ENDOG and suggest a pathway relating mtDNA content to the regulation of cell growth probably involving humanin, which prevents reactive oxygen radicals accumulation and hypertrophy induced by Endog deficiency. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

The Role of Hibiscus sabdariffa L. (Roselle) in Maintenance of Ex Vivo Murine Bone Marrow-Derived Hematopoietic Stem Cells

PubMed Central

Abdul Hamid, Zariyantey; Lin Lin, Winnie Hii; Abdalla, Basma Jibril; Bee Yuen, Ong; Latif, Elda Surhaida; Mohamed, Jamaludin; Rajab, Nor Fadilah; Paik Wah, Chow; Budin, Siti Balkis

2014-01-01

Hematopoietic stem cells- (HSCs-) based therapy requires ex vivo expansion of HSCs prior to therapeutic use. However, ex vivo culture was reported to promote excessive production of reactive oxygen species (ROS), exposing HSCs to oxidative damage. Efforts to overcome this limitation include the use of antioxidants. In this study, the role of Hibiscus sabdariffa L. (Roselle) in maintenance of cultured murine bone marrow-derived HSCs was investigated. Aqueous extract of Roselle was added at varying concentrations (0–1000 ng/mL) for 24 hours to the freshly isolated murine bone marrow cells (BMCs) cultures. Effects of Roselle on cell viability, reactive oxygen species (ROS) production, glutathione (GSH) level, superoxide dismutase (SOD) activity, and DNA damage were investigated. Roselle enhanced the survival (P < 0.05) of BMCs at 500 and 1000 ng/mL, increased survival of Sca-1+ cells (HSCs) at 500 ng/mL, and maintained HSCs phenotype as shown from nonremarkable changes of surface marker antigen (Sca-1) expression in all experimental groups. Roselle increased (P < 0.05) the GSH level and SOD activity but the level of reactive oxygen species (ROS) was unaffected. Moreover, Roselle showed significant cellular genoprotective potency against H2O2-induced DNA damage. Conclusively, Roselle shows novel property as potential supplement and genoprotectant against oxidative damage to cultured HSCs. PMID:25405216

Alternative Splicing Studies of the Reactive Oxygen Species Gene Network in Populus Reveal Two Isoforms of High-Isoelectric-Point Superoxide Dismutase1[C][W

PubMed Central

Srivastava, Vaibhav; Srivastava, Manoj Kumar; Chibani, Kamel; Nilsson, Robert; Rouhier, Nicolas; Melzer, Michael; Wingsle, Gunnar

2009-01-01

Recent evidence has shown that alternative splicing (AS) is widely involved in the regulation of gene expression, substantially extending the diversity of numerous proteins. In this study, a subset of expressed sequence tags representing members of the reactive oxygen species gene network was selected from the PopulusDB database to investigate AS mechanisms in Populus. Examples of all known types of AS were detected, but intron retention was the most common. Interestingly, the closest Arabidopsis (Arabidopsis thaliana) homologs of half of the AS genes identified in Populus are not reportedly alternatively spliced. Two genes encoding the protein of most interest in our study (high-isoelectric-point superoxide dismutase [hipI-SOD]) have been found in black cottonwood (Populus trichocarpa), designated PthipI-SODC1 and PthipI-SODC2. Analysis of the expressed sequence tag libraries has indicated the presence of two transcripts of PthipI-SODC1 (hipI-SODC1b and hipI-SODC1s). Alignment of these sequences with the PthipI-SODC1 gene showed that hipI-SODC1b was 69 bp longer than hipI-SODC1s due to an AS event involving the use of an alternative donor splice site in the sixth intron. Transcript analysis showed that the splice variant hipI-SODC1b was differentially expressed, being clearly expressed in cambial and xylem, but not phloem, regions. In addition, immunolocalization and mass spectrometric data confirmed the presence of hipI-SOD proteins in vascular tissue. The functionalities of the spliced gene products were assessed by expressing recombinant hipI-SOD proteins and in vitro SOD activity assays. PMID:19176719

Alternative splicing studies of the reactive oxygen species gene network in Populus reveal two isoforms of high-isoelectric-point superoxide dismutase.

PubMed

Srivastava, Vaibhav; Srivastava, Manoj Kumar; Chibani, Kamel; Nilsson, Robert; Rouhier, Nicolas; Melzer, Michael; Wingsle, Gunnar

2009-04-01

Recent evidence has shown that alternative splicing (AS) is widely involved in the regulation of gene expression, substantially extending the diversity of numerous proteins. In this study, a subset of expressed sequence tags representing members of the reactive oxygen species gene network was selected from the PopulusDB database to investigate AS mechanisms in Populus. Examples of all known types of AS were detected, but intron retention was the most common. Interestingly, the closest Arabidopsis (Arabidopsis thaliana) homologs of half of the AS genes identified in Populus are not reportedly alternatively spliced. Two genes encoding the protein of most interest in our study (high-isoelectric-point superoxide dismutase [hipI-SOD]) have been found in black cottonwood (Populus trichocarpa), designated PthipI-SODC1 and PthipI-SODC2. Analysis of the expressed sequence tag libraries has indicated the presence of two transcripts of PthipI-SODC1 (hipI-SODC1b and hipI-SODC1s). Alignment of these sequences with the PthipI-SODC1 gene showed that hipI-SODC1b was 69 bp longer than hipI-SODC1s due to an AS event involving the use of an alternative donor splice site in the sixth intron. Transcript analysis showed that the splice variant hipI-SODC1b was differentially expressed, being clearly expressed in cambial and xylem, but not phloem, regions. In addition, immunolocalization and mass spectrometric data confirmed the presence of hipI-SOD proteins in vascular tissue. The functionalities of the spliced gene products were assessed by expressing recombinant hipI-SOD proteins and in vitro SOD activity assays.

AhpA is a peroxidase expressed during biofilm formation in Bacillus subtilis.

PubMed

Zwick, Joelie V; Noble, Sarah; Ellaicy, Yasser K; Coe, Gabrielle Dierker; Hakey, Dylan J; King, Alyssa N; Sadauskas, Alex J; Faulkner, Melinda J

2017-02-01

Organisms growing aerobically generate reactive oxygen species such as hydrogen peroxide. These reactive oxygen molecules damage enzymes and DNA, potentially causing cell death. In response, Bacillus subtilis produces at least nine potential peroxide-scavenging enzymes; two belong to the alkylhydroperoxide reductase (Ahp) class of peroxidases. Here, we explore the role of one of these Ahp homologs, AhpA. While previous studies demonstrated that AhpA can scavenge peroxides and thus defend cells against peroxides, they did not clarify when during growth the cell produces AhpA. The results presented here show that the expression of ahpA is regulated in a manner distinct from that of the other peroxide-scavenging enzymes in B. subtilis. While the primary Ahp, AhpC, is expressed during exponential growth and stationary phase, these studies demonstrate that the expression of ahpA is dependent on the transition-state regulator AbrB and the sporulation and biofilm formation transcription factor Spo0A. Furthermore, these results show that ahpA is specifically expressed during biofilm formation, and not during sporulation or stationary phase, suggesting that derepression of ahpA by AbrB requires a signal other than those present upon entry into stationary phase. Despite this expression pattern, ahpA mutant strains still form and maintain robust biofilms, even in the presence of peroxides. Thus, the role of AhpA with regard to protecting cells within biofilms from environmental stresses is still uncertain. These studies highlight the need to further study the Ahp homologs to better understand how they differ from one another and the unique roles they may play in oxidative stress resistance. © 2016 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Quercetin manipulates the expression of genes involved in the reactive oxygen species (ROS) processin chicken heterophils.

PubMed

Nambooppha, Boondarika; Photichai, Kornravee; Wongsawan, Kanreuthai; Chuammitri, Phongsakorn

2018-06-06

Chicken heterophils generate reactive oxygen species (ROS) molecules to defend against invading pathogens. The present study examined effects of quercetin on chicken heterophils. Heterophils were stimulated with PBS, 50 μM quercetin (QH), PMA or Escherichia coli (EC) and the resulting intracellular ROS molecules were determined. Flow cytometry results showed that cells stimulated with QH, PMA and EC had a higher ROS production. Increases in intracellular ROS molecules were identified in all treatment groups by fluorescence microscopy. Determination of the ability of quercetin to manipulate mRNA expression of ROS subunits was assessed using real-time RT-PCR. Quercetin and other stimulants up-regulated the majority of genes involved in ROS production: CYBB (NOX2), NCF1 (p47 phox ), NCF2 (p67 phox ), NOX1 and RAC2. The antioxidant property of QH was explored by measuring mRNA expression of CAT and SOD1. The data indicate increased levels of CAT with all treatments; however, only QH attenuated the expression ofthe SOD1 gene. To further investigate the effects of ROS-driven inflammation or cell death, IL6, CASP8, and MCL1 genes were preferentially tested. The inflammatory gene (IL6) was profoundly down-regulated in the QH- and PMA-treated groups while EC induced a strikingly high IL6 expression level. Investigation of the known apoptotic (CASP8) and anti-apoptotic (MCL1) genes found down-regulation of CASP8 in the QH- and PMA-treated groups which were contradicted to the MCL1 gene. In conclusion, quercetin can enhance ROS production by regulating the expression of genes involved in ROS production as well as in subsequent processes.

The Mitochondrial Cardiolipin Remodeling Enzyme Lysocardiolipin Acyltransferase Is a Novel Target in Pulmonary Fibrosis

PubMed Central

Huang, Long Shuang; Mathew, Biji; Zhao, Yutong; Noth, Imre; Reddy, Sekhar P.; Harijith, Anantha; Usatyuk, Peter V.; Berdyshev, Evgeny V.; Kaminski, Naftali; Zhou, Tong; Zhang, Wei; Zhang, Yanmin; Rehman, Jalees; Kotha, Sainath R.; Gurney, Travis O.; Parinandi, Narasimham L.; Lussier, Yves A.; Garcia, Joe G. N.

2014-01-01

Rationale: Lysocardiolipin acyltransferase (LYCAT), a cardiolipin-remodeling enzyme regulating the 18:2 linoleic acid pattern of mammalian mitochondrial cardiolipin, is necessary for maintaining normal mitochondrial function and vascular development. We hypothesized that modulation of LYCAT expression in lung epithelium regulates development of pulmonary fibrosis. Objectives: To define a role for LYCAT in human and murine models of pulmonary fibrosis. Methods: We analyzed the correlation of LYCAT expression in peripheral blood mononuclear cells (PBMCs) with the outcomes of pulmonary functions and overall survival, and used the murine models to establish the role of LYCAT in fibrogenesis. We studied the LYCAT action on cardiolipin remodeling, mitochondrial reactive oxygen species generation, and apoptosis of alveolar epithelial cells under bleomycin challenge. Measurements and Main Results: LYCAT expression was significantly altered in PBMCs and lung tissues from patients with idiopathic pulmonary fibrosis (IPF), which was confirmed in two preclinical murine models of IPF, bleomycin- and radiation-induced pulmonary fibrosis. LYCAT mRNA expression in PBMCs directly and significantly correlated with carbon monoxide diffusion capacity, pulmonary function outcomes, and overall survival. In both bleomycin- and radiation-induced pulmonary fibrosis murine models, hLYCAT overexpression reduced several indices of lung fibrosis, whereas down-regulation of native LYCAT expression by siRNA accentuated fibrogenesis. In vitro studies demonstrated that LYCAT modulated bleomycin-induced cardiolipin remodeling, mitochondrial membrane potential, reactive oxygen species generation, and apoptosis of alveolar epithelial cells, potential mechanisms of LYCAT-mediated lung protection. Conclusions: This study is the first to identify modulation of LYCAT expression in fibrotic lungs and offers a novel therapeutic approach for ameliorating lung inflammation and pulmonary fibrosis. PMID:24779708

Spermine reduces reactive oxygen species levels and decreases cryocapacitation in canine sperm cryopreservation.

PubMed

Setyawan, Erif Maha Nugraha; Kim, Min Jung; Oh, Hyun Ju; Kim, Geon A; Jo, Young Kwang; Lee, Seok Hee; Choi, Yoo Bin; Lee, Byeong Chun

2016-10-28

The objective of this study was to determine the ability of spermine to act as an antioxidant in scavenging reactive oxygen species (ROS), maintaining sperm function and decreasing cryocapacitation after cryopreservation. Although motility did not increase with spermine treatment, values for membrane integrity were significantly increased (P < 0.05). Higher percentages of linearity and straightness with a lower amplitude of lateral head displacement (ALH) indicated that spermine inhibits hyperactivation. Concentrations of intracellular and extracellular ROS were decreased in the treatment group (P < 0.05). Higher expression of an anti-apoptotic gene (Bcl-2) and lower expression of a pro-apoptotic gene (Bax), together with decreased expression of the mitochondrial ROS modulator ROMO1, DNA repair due to oxidative damage (OGG1), spermine synthase (SMS), NADPH oxidase associated with motility (NOX5) and spermine amino oxidase (SMOX), all showed that 5.0 mM spermine treatment was beneficial to spermatozoa. Furthermore, the proportion of live spermatozoa with intact acrosomes after thawing in the treatment group was higher than in the control. After incubation in canine capacitating medium, numbers of live capacitated spermatozoa with reacted acrosomes were higher than in the control. Our results indicate that 5.0 mM spermine is an optimal concentration for maintaining sperm function, reducing ROS production, preventing apoptosis and adverse effects of cryocapacitation during canine sperm cryopreservation. Copyright © 2016 Elsevier Inc. All rights reserved.

Loss of SLP-76 expression within myeloid cells confers resistance to neutrophil-mediated tissue damage while maintaining effective bacterial killing.

PubMed

Clemens, Regina A; Lenox, Laurie E; Kambayashi, Taku; Bezman, Natalie; Maltzman, Jonathan S; Nichols, Kim E; Koretzky, Gary A

2007-04-01

The Src homology 2 domain-containing leukocyte phosphoprotein of 76 kDa (SLP-76) is an adaptor molecule critical for immunoreceptor and integrin signaling in multiple hemopoietic lineages. We showed previously that SLP-76 is required for neutrophil function in vitro, including integrin-induced adhesion and production of reactive oxygen intermediates, and to a lesser extent, FcgammaR-induced calcium flux and reactive oxygen intermediate production. It has been difficult to determine whether SLP-76 regulates neutrophil responses in vivo, because Slp-76(-/-) mice exhibit marked defects in thymocyte and vascular development, as well as platelet and mast cell function. To circumvent these issues, we generated mice with targeted loss of SLP-76 expression within myeloid cells. Neutrophils obtained from these animals failed to respond to integrin activation in vitro, similar to Slp-76(-/-) cells. Despite these abnormalities, SLP-76-deficient neutrophils migrated normally in vivo in response to Staphylococcus aureus infection and efficiently cleared micro-organisms. Interestingly, SLP-76-deficient neutrophils did not induce a robust inflammatory response in the localized Shwartzman reaction. Collectively, these data suggest that disruption of integrin signaling via loss of SLP-76 expression differentially impairs neutrophil functions in vivo, with preservation of migration and killing of S. aureus but reduction in LPS-induced tissue damage and vascular injury.

Fibronectin type III domain containing 5 attenuates NLRP3 inflammasome activation and phenotypic transformation of adventitial fibroblasts in spontaneously hypertensive rats.

PubMed

Ling, Li; Chen, Dan; Tong, Ying; Zang, Ying-Hao; Ren, Xing-Sheng; Zhou, Hong; Qi, Xiao-Hong; Chen, Qi; Li, Yue-Hua; Kang, Yu-Ming; Zhu, Guo-Qing

2018-05-01

Phenotypic transformation of adventitial fibroblasts is important in the pathogenesis of hypertension. This study was designed to determine whether fibronectin type III domain containing 5 (FNDC5) alleviates the phenotypic transformation of adventitial fibroblasts in hypertension and the underlying mechanisms. Experiments were carried out in spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) and primary aortic adventitial fibroblasts. FNDC5 was downregulated and NLRP3 inflammasome was activated in aortic adventitia of SHR. FNDC5 overexpression attenuated adventitial fibroblasts phenotypic transformation, excessive synthesis and secretion of matrix components, NLRP3 inflammasome activation and inflammation in adventitial fibroblasts from SHR. Moreover, FNDC5 overexpression reduced NADPH oxidase 2 (NOX2) expression and reactive oxygen species (ROS) production in adventitial fibroblasts from SHR. Similarly, exogenous FNDC5 inhibited adventitial fibroblasts phenotypic transformation, expression of matrix components, NLRP3 inflammasome activation and NOX2 expression in adventitial fibroblasts from SHR. FNDC5 overexpression in rats attenuated phenotypic transformation, inflammation and reactive oxygen species (ROS) production in the aortic adventitia of SHR. Furthermore, FNDC5 overexpression reduced blood pressure and alleviated vascular remodeling in SHR. FNDC5 reduces NOX2-derived ROS production, NLRP3 inflammasome activation and phenotypic transformation in adventitial fibroblasts of SHR. FNDC5 plays a beneficial role in attenuating vascular inflammation, vascular remodeling and hypertension in SHR.

Expression of a truncated human tau protein induces aqueous-phase free radicals in a rat model of tauopathy: implications for targeted antioxidative therapy.

PubMed

Cente, Martin; Filipcik, Peter; Mandakova, Stanislava; Zilka, Norbert; Krajciova, Gabriela; Novak, Michal

2009-01-01

Oxidative stress has been implicated in the pathogenesis of many neurodegenerative diseases including Alzheimer's disease (AD). We investigated the effect of a truncated form of the human tau protein in the neurons of transgenic rats. Using electron paramagnetic resonance we observed significantly increased accumulation of ascorbyl free radicals in brains of transgenic animals (up to 1.5-fold increase; P < 0.01). Examination of an in vitro model of cultured rat corticohippocampal neurons revealed that even relatively low level expression of human truncated tau protein (equal to 50% of endogenous tau) induced oxidative stress that resulted in increased depolarization of mitochondria (approximately 1.2-fold above control, P < 0.01) and increases in reactive oxygen species (approximately 1.3-fold above control, P < 0.001). We show that mitochondrial damage-associated oxidative stress is an early event in neurodegeneration. Furthermore, using two common antioxidants (vitamin C and E), we were able significantly eliminate tau-induced elevation of reactive oxygen species. Interestingly, vitamin C was found to be selective in the scavenging activity, suggesting that expression of truncated tau protein preferentially leads to increases in aqueous phase oxidants and free radicals such as hydrogen peroxide and hydroxyl and superoxide radicals. Our results suggest that antioxidant strategies designed to treat AD should focus on elimination of aqueous phase oxidants and free radicals.

Light irradiation helps magnetotactic bacteria eliminate intracellular reactive oxygen species.

PubMed

Li, Kefeng; Wang, Pingping; Chen, Chuanfang; Chen, Changyou; Li, Lulu; Song, Tao

2017-09-01

Magnetotactic bacteria (MTB) demonstrate photoresponse. However, little is known about the biological significance of this behaviour. Magnetosomes exhibit peroxidase-like activity and can scavenge reactive oxygen species (ROS). Magnetosomes extracted from the Magnetospirillum magneticum strain AMB-1 show enhanced peroxidase-like activity under illumination. The present study investigated the effects of light irradiation on nonmagnetic (without magnetosomes) and magnetic (with magnetosomes) AMB-1 cells. Results showed that light irradiation did not affect the growth of nonmagnetic and magnetic cells but significantly increased magnetosome synthesis and reduced intracellular ROS level in magnetic cells. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed to analyse the expression level of magnetosome formation-associated genes (mamA, mms6, mms13 and mmsF) and stress-related genes (recA, oxyR, SOD, amb0664 and amb2684). Results showed that light irradiation upregulated the expression of mms6, mms13 and mmsF. Furthermore, light irradiation upregulated the expression of stress-related genes in nonmagnetic cells but downregulated them in magnetic cells. Additionally, magnetic cells exhibited stronger phototactic behaviour than nonmagnetic ones. These results suggested that light irradiation could heighten the ability of MTB to eliminate intracellular ROS and help them adapt to lighted environments. This phenomenon may be related to the enhanced peroxidase-like activity of magnetosomes under light irradiation. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

Differential expression of islet glutaredoxin 1 and 5 with high reactive oxygen species production in a mouse model of diabesity.

PubMed

Petry, Sebastian Friedrich; Sharifpanah, Fatemeh; Sauer, Heinrich; Linn, Thomas

2017-01-01

The onset and progression of diabetes mellitus type 2 is highly contingent on the amount of functional beta-cell mass. An underlying cause of beta-cell decay in diabetes is oxidative stress, which markedly affects the insulin producing pancreatic cells due to their poor antioxidant defence capacity. Consequently, disturbances of cellular redox signaling have been implicated to play a major role in beta-cell loss in diabetes mellitus type 2. There is evidence suggesting that the glutaredoxin (Grx) system exerts a protective role for pancreatic islets, but the exact mechanisms have not yet been elucidated. In this study, a mouse model for diabetes mellitus type 2 was used to gain further insight into the significance of Grx for the islets of Langerhans in the diabetic metabolism. We have observed distinct differences in the expression levels of Grx in pancreatic islets between obese, diabetic db mice and lean, non-diabetic controls. This finding is the first report about a decrease of Grx expression levels in pancreatic islets of diabetic mice which was accompanied by declining insulin secretion, increase of reactive oxygen species (ROS) production level, and cell cycle alterations. These data demonstrate the essential role of the Grx system for the beta-cell during metabolic stress which may provide a new target for diabetes mellitus type 2 treatment.

Reduction in ins-7 gene expression in non-neuronal cells of high glucose exposed Caenorhabditis elegans protects from reactive metabolites, preserves neuronal structure and head motility, and prolongs lifespan.

PubMed

Mendler, Michael; Riedinger, Christin; Schlotterer, Andrea; Volk, Nadine; Fleming, Thomas; Herzig, Stephan; Nawroth, Peter P; Morcos, Michael

2017-02-01

Glucose derived metabolism generates reactive metabolites affecting the neuronal system and lifespan in C. elegans. Here, the role of the insulin homologue ins-7 and its downstream effectors in the generation of high glucose induced neuronal damage and shortening of lifespan was studied. In C. elegans high glucose conditions induced the expression of the insulin homologue ins-7. Abrogating ins-7 under high glucose conditions in non-neuronal cells decreased reactive oxygen species (ROS)-formation and accumulation of methylglyoxal derived advanced glycation endproducts (AGEs), prevented structural neuronal damage and normalised head motility and lifespan. The restoration of lifespan by decreased ins-7 expression was dependent on the concerted action of sod-3 and glod-4 coding for the homologues of iron-manganese superoxide dismutase and glyoxalase 1, respectively. Under high glucose conditions mitochondria-mediated oxidative stress and glycation are downstream targets of ins-7. This impairs the neuronal system and longevity via a non-neuronal/neuronal crosstalk by affecting sod-3 and glod-4, thus giving further insight into the pathophysiology of diabetic complications. Copyright © 2017 Elsevier Inc. All rights reserved.

Vacuum ultraviolet radiation/atomic oxygen synergism in materials reactivity

NASA Technical Reports Server (NTRS)

Koontz, Steven; Leger, Lubert; Albyn, Keith; Cross, Jon

1990-01-01

Experimental results are presented which indicate that low fluxes of vacuum UV (VUV) radiation exert a pronounced influence on the atomic oxygen reactivity of such fluorocarbon and fluorocarbon spacecraft materials as the FEP Teflon and PCTFE that are under consideration for the Space Station Freedom. With simultaneous exposure to VUV fluxes comparable to those experienced in LEO, the reactivity of these materials becomes comparable to that of Kapton; VUV radiation has also been shown to increase the reactivity of Kapton with thermal-energy oxygen atoms.

Characterizing Myeloid Cell Activation in NF1 Vasculopathy

DTIC Science & Technology

2017-07-01

stimulation of its receptor (CCR2) and the generation of reactive oxygen species, which are generated in excessive quantities by neurofibromin-deficient...macrophages via monocyte chemotactic peptide-1 (MCP-1) stimulation of its receptor (CCR2) and the generation of reactive oxygen species, which are...neurofibromatosis; stenosis; aneurysm; MCP-1; CCR2; reactive oxygen species; superoxide; macrophages; monocytes; arteries; cardiovascular disease Major

Exogenous heat shock protein HSP70 reduces response of human neuroblastoma cells to lipopolysaccharide.

PubMed

Yurinskaya, M M; Funikov, S Y; Evgen'ev, M B; Vinokurov, M G

2016-07-01

The effect of exogenous heat shock protein HSP70 and lipopolysaccharide (LPS) on the production of reactive oxygen species (ROS), TNFα secretion, and mRNA expression by human neuroblastoma SK-N-SH cells. It was shown that exogenous HSP70 protects neuroblastoma cells from the action of LPS. The protection mechanism of HSP70 includes a reduction in the production of ROS and TNFα and a decrease in the expression of TLR4 and IL-1β mRNA in SK-N-SH cells induced by LPS.

Microcarbon-based facial creams activate aerial oxygen under light to reactive oxygen species damaging cell

NASA Astrophysics Data System (ADS)

Maity, Sheli; Pakhira, Bholanath; Ghosh, Subrata; Saha, Royina; Sarkar, Ripon; Barui, Ananya; Sarkar, Sabyasachi

2017-11-01

Nanosized reduced graphene oxide (rGO) is found in active microcarbon used in popular face cream from the manufacturers like Ponds, Nevia, and Garnier which, under visible light exposure, gets activated by aerial oxygen to generate reactive oxygen species (ROS) harmful to skin.

Antagonistic Basic Helix-Loop-Helix/bZIP Transcription Factors Form Transcriptional Modules That Integrate Light and Reactive Oxygen Species Signaling in Arabidopsis[W

PubMed Central

Chen, Dongqin; Xu, Gang; Tang, Weijiang; Jing, Yanjun; Ji, Qiang; Fei, Zhangjun; Lin, Rongcheng

2013-01-01

The critical developmental switch from heterotrophic to autotrophic growth of plants involves light signaling transduction and the production of reactive oxygen species (ROS). ROS function as signaling molecules that regulate multiple developmental processes, including cell death. However, the relationship between light and ROS signaling remains unclear. Here, we identify transcriptional modules composed of the basic helix-loop-helix and bZIP transcription factors PHYTOCHROME-INTERACTING FACTOR1 (PIF1), PIF3, ELONGATED HYPOCOTYL5 (HY5), and HY5 HOMOLOGY (HYH) that bridge light and ROS signaling to regulate cell death and photooxidative response. We show that pif mutants release more singlet oxygen and exhibit more extensive cell death than the wild type during Arabidopsis thaliana deetiolation. Genome-wide expression profiling indicates that PIF1 represses numerous ROS and stress-related genes. Molecular and biochemical analyses reveal that PIF1/PIF3 and HY5/HYH physically interact and coordinately regulate the expression of five ROS-responsive genes by directly binding to their promoters. Furthermore, PIF1/PIF3 and HY5/HYH function antagonistically during the seedling greening process. In addition, phytochromes, cryptochromes, and CONSTITUTIVE PHOTOMORPHOGENIC1 act upstream to regulate ROS signaling. Together, this study reveals that the PIF1/PIF3-HY5/HYH transcriptional modules mediate crosstalk between light and ROS signaling and sheds light on a new mechanism by which plants adapt to the light environments. PMID:23645630

APR3 modulates oxidative stress and mitochondrial function in ARPE-19 cells.

PubMed

Li, Yuan; Zou, Xuan; Gao, Jing; Cao, Ke; Feng, Zhihui; Liu, Jiankang

2018-05-24

Impairment of retinal pigment epithelial (RPE) cells is considered a key contributor to the development of age-related macular degeneration. Apoptosis-related protein 3 (APR3) was recently discovered after treatment with all- trans retinoic acid, a pivotal molecule in RPE cells. However, the function of APR3 remains poorly understood. In the present study, we found that APR3 could interact with nuclear factor (erythroid-derived 2)-like 2, which is a regulator of phase II enzymes, and that knockdown of APR3 promoted nuclear factor (erythroid-derived 2)-like 2 nuclear translocation and activated expression of phase II enzymes, which was accompanied by improved redox status and mitochondrial activity. Overexpression of APR3 revealed its mitochondrial localization and induced a robust production of reactive oxygen species that was accompanied by impaired mitochondrial oxygen consumption, complex activity, and lower ATP content, resulting in significant changes in mitochondrial structure, which may contribute to cell apoptosis. High doses of all- trans retinoic acid treatment were found to significantly induce APR3 expression, increase reactive oxygen species levels, and decrease ATP content, which were abolished by knockdown of APR3. These results indicate that APR3 plays a vital role in regulating redox status and mitochondrial activity and thus suggest APR3 might be a potential novel target for study of treatment of age-related macular degeneration.-Li, Y., Zou, X., Gao, J., Cao, K., Feng, Z., Liu, J. APR3 modulates oxidative stress and mitochondrial function in ARPE-19 cells.

Impact of sleep quality on amygdala reactivity, negative affect, and perceived stress.

PubMed

Prather, Aric A; Bogdan, Ryan; Hariri, Ahmad R

2013-05-01

Research demonstrates a negative impact of sleep disturbance on mood and affect; however, the biological mechanisms mediating these links are poorly understood. Amygdala reactivity to negative stimuli has emerged as one potential pathway. Here, we investigate the influence of self-reported sleep quality on associations between threat-related amygdala reactivity and measures of negative affect and perceived stress. Analyses on data from 299 participants (125 men, 50.5% white, mean [standard deviation] age = 19.6 [1.3] years) who completed the Duke Neurogenetics Study were conducted. Participants completed several self-report measures of negative affect and perceived stress. Threat-related (i.e., angry and fearful facial expressions) amygdala reactivity was assayed using blood oxygen level-dependent functional magnetic resonance imaging. Global sleep quality was assessed using the Pittsburgh Sleep Quality Index. Amygdala reactivity to fearful facial expressions predicted greater depressive symptoms and higher perceived stress in poor (β values = 0.18-1.86, p values < .05) but not good sleepers (β values = -0.13 to -0.01, p values > .05). In sex-specific analyses, men reporting poorer global sleep quality showed a significant association between amygdala reactivity and levels of depression and perceived stress (β values = 0.29-0.44, p values < .05). In contrast, no significant associations were observed in men reporting good global sleep quality or in women, irrespective of sleep quality. This study provides novel evidence that self-reported sleep quality moderates the relationships between amygdala reactivity, negative affect, and perceived stress, particularly among men.

Proteomic analysis of UVB-induced protein expression- and redox-dependent changes in skin fibroblasts using lysine- and cysteine-labeling two-dimensional difference gel electrophoresis.

PubMed

Wu, Chieh-Lin; Chou, Hsiu-Chuan; Cheng, Chao-Sheng; Li, Ji-Min; Lin, Szu-Ting; Chen, Yi-Wen; Chan, Hong-Lin

2012-04-03

UVB is the most energetic and DNA-damaging to humans in ultraviolet radiation. Previous research has suggested that exposure to UVB causes skin pathologies because of direct DNA damage and the generation of reactive oxygen species (ROS). However, the detailed molecular mechanisms by which UVB leads to skin cancer have yet to be clarified. In the current study, normal skin fibroblast cells (CCD-966SK) were exposed to various doses of UVB, and the changes in protein expression and thiol reactivity were monitored with lysine- and cysteine-labeling 2D-DIGE and MALDI-TOF mass spectrometry. Our proteomic analysis revealed that 89 identified proteins showed significant changes in protein expression, and 37 in thiol reactivity. Many proteins that are known to be involved in protein folding, redox regulation and nucleotide biosynthesis were up-regulated under UVB irradiation. In contrast, proteins responsible for biosynthesis and protein degradation were down-regulated. In addition, the thiol-reactivity of proteins involving cytoskeleton, metabolism, and signal transduction were altered by UVB. In summary, these UVB-modulated cellular proteins and redox-regulated proteins might play important roles in the early stages of skin cancer formation and photoaging induced by UVB-irradiation. Such proteins might provide a potential target for the rational design of drugs to prevent UVB-induced diseases. Copyright © 2011 Elsevier B.V. All rights reserved.

Transcriptome analysis of Lactococcus lactis subsp. lactis during milk acidification as affected by dissolved oxygen and the redox potential.

PubMed

Larsen, Nadja; Moslehi-Jenabian, Saloomeh; Werner, Birgit Brøsted; Jensen, Maiken Lund; Garrigues, Christel; Vogensen, Finn Kvist; Jespersen, Lene

2016-06-02

Performance of Lactococcus lactis as a starter culture in dairy fermentations depends on the levels of dissolved oxygen and the redox state of milk. In this study the microarray analysis was used to investigate the global gene expression of L. lactis subsp. lactis DSM20481(T) during milk acidification as affected by oxygen depletion and the decrease of redox potential. Fermentations were carried out at different initial levels of dissolved oxygen (dO2) obtained by milk sparging with oxygen (high dO2, 63%) or nitrogen (low dO2, 6%). Bacterial exposure to high initial oxygen resulted in overexpression of genes involved in detoxification of reactive oxygen species (ROS), oxidation-reduction processes, biosynthesis of trehalose and down-regulation of genes involved in purine nucleotide biosynthesis, indicating that several factors, among them trehalose and GTP, were implicated in bacterial adaptation to oxidative stress. Generally, transcriptional changes were more pronounced during fermentation of oxygen sparged milk. Genes up-regulated in response to oxygen depletion were implicated in biosynthesis and transport of pyrimidine nucleotides, branched chain amino acids and in arginine catabolic pathways; whereas genes involved in salvage of nucleotides and cysteine pathways were repressed. Expression pattern of genes involved in pyruvate metabolism indicated shifts towards mixed acid fermentation after oxygen depletion with production of specific end-products, depending on milk treatment. Differential expression of genes, involved in amino acid and pyruvate pathways, suggested that initial oxygen might influence the release of flavor compounds and, thereby, flavor development in dairy fermentations. The knowledge of molecular responses involved in adaptation of L. lactis to the shifts of redox state and pH during milk fermentations is important for the dairy industry to ensure better control of cheese production. Copyright © 2016 Elsevier B.V. All rights reserved.

Pneumococcal infection of respiratory cells exposed to welding fumes; Role of oxidative stress and HIF-1 alpha.

PubMed

Grigg, Jonathan; Miyashita, Lisa; Suri, Reetika

2017-01-01

Welders are more susceptible to pneumococcal pneumonia. The mechanisms are yet unclear. Pneumococci co-opt the platelet activating factor receptor (PAFR) to infect respiratory epithelial cells. We previously reported that exposure of respiratory cells to welding fumes (WF), upregulates PAFR-dependent pneumococcal infection. The signaling pathway for this response is unknown, however, in intestinal cells, hypoxia-inducible factor-1 α (HIF 1α) is reported to mediate PAFR-dependent infection. We sought to assess whether oxidative stress plays a role in susceptibility to pneumococcal infection via the platelet activating factor receptor. We also sought to evaluate the suitability of nasal epithelial PAFR expression in welders as a biomarker of susceptibility to infection. Finally, we investigated the generalisability of the effect of welding fumes on pneumococcal infection and growth using a variety of different welding fume samples. Nasal epithelial PAFR expression in welders and controls was analysed by flow cytometry. WF were collected using standard methodology. The effect of WF on respiratory cell reactive oxygen species production, HIF-1α expression, and pneumococcal infection was determined using flow cytometry, HIF-1α knockdown and overexpression, and pneumococcal infection assays. We found that nasal PAFR expression is significantly increased in welders compared with controls and that WF significantly increased reactive oxygen species production, HIF-1α and PAFR expression, and pneumococcal infection of respiratory cells. In unstimulated cells, HIF-1α knockdown decreased PAFR expression and HIF-1α overexpression increased PAFR expression. However, in knockdown cells pneumococcal infection was paradoxically increased and in overexpressing cells infection was unaffected. Nasal epithelial PAFR expression may be used as a biomarker of susceptibility to pneumococcal infection in order to target individuals, particularly those at high risk such as welders, for the pneumococcal vaccine. Expression of HIF-1α in unexposed respiratory cells inhibits basal pneumococcal infection via PAFR-independent mechanisms.

Measurement of Reactive Oxygen Species, Reactive Nitrogen Species, and Redox-Dependent Signaling in the Cardiovascular System: A Scientific Statement From the American Heart Association.

PubMed

Griendling, Kathy K; Touyz, Rhian M; Zweier, Jay L; Dikalov, Sergey; Chilian, William; Chen, Yeong-Renn; Harrison, David G; Bhatnagar, Aruni

2016-08-19

Reactive oxygen species and reactive nitrogen species are biological molecules that play important roles in cardiovascular physiology and contribute to disease initiation, progression, and severity. Because of their ephemeral nature and rapid reactivity, these species are difficult to measure directly with high accuracy and precision. In this statement, we review current methods for measuring these species and the secondary products they generate and suggest approaches for measuring redox status, oxidative stress, and the production of individual reactive oxygen and nitrogen species. We discuss the strengths and limitations of different methods and the relative specificity and suitability of these methods for measuring the concentrations of reactive oxygen and reactive nitrogen species in cells, tissues, and biological fluids. We provide specific guidelines, through expert opinion, for choosing reliable and reproducible assays for different experimental and clinical situations. These guidelines are intended to help investigators and clinical researchers avoid experimental error and ensure high-quality measurements of these important biological species. © 2016 American Heart Association, Inc.

Nitrite produced by Mycobacterium tuberculosis in human macrophages in physiologic oxygen impacts bacterial ATP consumption and gene expression

PubMed Central

Cunningham-Bussel, Amy; Zhang, Tuo; Nathan, Carl F.

2013-01-01

In high enough concentrations, such as produced by inducible nitric oxide synthase (iNOS), reactive nitrogen species (RNS) can kill Mycobacterium tuberculosis (Mtb). Lesional macrophages in macaques and humans with tuberculosis express iNOS, and mice need iNOS to avoid succumbing rapidly to tuberculosis. However, Mtb’s own ability to produce RNS is rarely considered, perhaps because nitrate reduction to nitrite is only prominent in axenic Mtb cultures at oxygen tensions ≤1%. Here we found that cultures of Mtb-infected human macrophages cultured at physiologic oxygen tensions produced copious nitrite. Surprisingly, the nitrite arose from the Mtb, not the macrophages. Mtb responded to nitrite by ceasing growth; elevating levels of ATP through reduced consumption; and altering the expression of 120 genes associated with adaptation to acid, hypoxia, nitric oxide, oxidative stress, and iron deprivation. The transcriptomic effect of endogenous nitrite was distinct from that of nitric oxide. Thus, whether or not Mtb is hypoxic, the host expresses iNOS, or hypoxia impairs the action of iNOS, Mtb in vivo is likely to encounter RNS by producing nitrite. Endogenous nitrite may slow Mtb’s growth and prepare it to resist host stresses while the pathogen waits for immunopathology to promote its transmission. PMID:24145454

Effects of peptides on generation of reactive oxygen species in subcellular fractions of Drosophila melanogaster.

PubMed

Khavinson, V K; Myl'nikov, S V; Oparina, T I; Arutyunyan, A V

2001-07-01

We studied the effects of Epithalon (Ala-Glu-Asp-Gly) and Vilon (Lys-Glu) on free radical processes in highly inbred HA(+)line of Drosophila melanogaster. Vilon inhibited generation of reactive oxygen species in mitochondria, but stimulated this process in the cytosol. We found sex- and age-related differences in the generation of reactive oxygen species and cytosol antioxidant activity.

Dose of 3-methylcholanthrene enhances vitamin C accumulation and mRNA expression of its transporter in the liver of ODS rats and in HepG2 cells.

PubMed

Sone, Yasuko; Ueta, Etsuko; Sannomaru, Yasuko; Miyake, Noriko; Sone, Hirohito; Otsuka, Yuzuru; Kondo, Kazuo; Kurata, Tadao; Suzuki, Emiko

2011-01-01

Polycyclic aromatic hydrocarbon (PAH) compounds including 3-methylcholanthrene induce harmful reactive intermediates and reactive oxygen species. This study reports the effect of 3-methylcholanthrene on the accumulation of vitamin C and the expression of vitamin C transporters. ODS rats were given l-ascorbic acid daily and intraperitoneal injections of 10 mg 3-methylcholanthrene in total. On day 10, vitamin C concentrations and the expression of vitamin C transporter in the tissues were measured. As a result, the levels of sodium-dependent vitamin C transporter (SVCTs) 1 and the l-ascorbic acid concentration in 3-methylcholanthrene-treated livers and hepatocytes have increased significantly. However, the content of vitamin C in the urine and TBARS in the liver have not changed. These results suggest that the administration of 3-methylcholanthrene elevates the requirement for vitamin C via (SVCTs) 1 due to xenobitics-metabolizing, such as the induction of cytochrome P450 family. Copyright © 2011 Wiley Periodicals, Inc.

Plateau Waves of Intracranial Pressure and Partial Pressure of Cerebral Oxygen.

PubMed

Lang, Erhard W; Kasprowicz, Magdalena; Smielewski, Peter; Pickard, John; Czosnyka, Marek

2016-01-01

This study investigates 55 intracranial pressure (ICP) plateau waves recorded in 20 patients after severe traumatic brain injury (TBI) with a focus on a moving correlation coefficient between mean arterial pressure (ABP) and ICP, called PRx, which serves as a marker of cerebrovascular reactivity, and a moving correlation coefficient between ABP and cerebral partial pressure of oxygen (pbtO2), called ORx, which serves as a marker for cerebral oxygen reactivity. ICP and ICPamplitude increased significantly during the plateau waves, whereas CPP and pbtO2 decreased significantly. ABP, ABP amplitude, and heart rate remained unchanged. In 73 % of plateau waves PRx increased during the wave. ORx showed an increase during and a decrease after the plateau waves, which was not statistically significant. Our data show profound cerebral vasoparalysis on top of the wave and, to a lesser extent, impairment of cerebral oxygen reactivity. The different behavior of the indices may be due to the different latencies of the cerebral blood flow and oxygen level control mechanisms. While cerebrovascular reactivity is a rapidly reacting mechanism, cerebral oxygen reactivity is slower.

Hydrogen cyanamide breaks grapevine bud dormancy in the summer through transient activation of gene expression and accumulation of reactive oxygen and nitrogen species.

PubMed

Sudawan, Boonyawat; Chang, Chih-Sheng; Chao, Hsiu-Fung; Ku, Maurice S B; Yen, Yung-Fu

2016-09-15

Hydrogen cyanamide (HC) and pruning (P) have frequently been used to break dormancy in grapevine floral buds. However, the exact underlying mechanism remains elusive. This study aimed to address the early mode of action of these treatments on accumulation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) and expression of related genes in the dormancy breaking buds of grapevine in the summer. The budbreak rates induced by pruning (P), hydrogen cyanamide (HC), pruning plus hydrogen cyanamide (PHC) and water (control) after 8 days were 33, 53, 95, and 0 %, respectively. Clearly, HC was more effective in stimulating grapevine budbreak and P further enhanced its potency. In situ staining of longitudinal bud sections after 12 h of treatments detected high levels of ROS and nitric oxide (NO) accumulated in the buds treated with PHC, compared with HC or P alone. The amounts of ROS and NO accumulated were highly correlated with the rates of budbreak among these treatments, highlighting the importance of a rapid, transient accumulation of sublethal levels of ROS and RNS in dormancy breaking. Microarray analysis revealed specific alterations in gene expression in dormancy breaking buds induced by P, HC and PHC after 24 h of treatment. Relative to control, PHC altered the expression of the largest number of genes, while P affected the expression of the least number of genes. PHC also exerted a greater intensity in transcriptional activation of these genes. Gene ontology (GO) analysis suggests that alteration in expression of ROS related genes is the major factor responsible for budbreak. qRT-PCR analysis revealed the transient expression dynamics of 12 specific genes related to ROS generation and scavenge during the 48 h treatment with PHC. Our results suggest that rapid accumulation of ROS and NO at early stage is important for dormancy release in grapevine in the summer, and the identification of the commonly expressed specific genes among the treatments allowed the construction of the signal transduction pathway related to ROS/RNS metabolism during dormancy release. The rapid accumulation of a sublethal level of ROS/RNS subsequently induces cell wall loosening and expansion for bud sprouting.

Production and Consumption of Reactive Oxygen Species by Fullerenes

EPA Science Inventory

Reactive oxygen species (ROS) are one of the most important intermediates in chemical, photochemical, and biological processes. To understand the environmental exposure and toxicity of fullerenes better, the production and consumption of ROS (singlet oxygen, superoxide, hydrogen ...

SIRT3 opposes reprogramming of cancer cell metabolism through HIF1α destabilization

PubMed Central

Finley, Lydia W.S.; Carracedo, Arkaitz; Lee, Jaewon; Souza, Amanda; Egia, Ainara; Zhang, Jiangwen; Teruya-Feldstein, Julie; Moreira, Paula I.; Cardoso, Sandra M.; Clish, Clary B.; Pandolfi, Pier Paolo; Haigis, Marcia C.

2011-01-01

Summary Tumor cells exhibit aberrant metabolism characterized by high glycolysis even in the presence of oxygen. This metabolic reprogramming, known as the Warburg effect, provides tumor cells with the substrates required for biomass generation. Here, we show that the mitochondrial NAD-dependent deacetylase SIRT3 is a crucial regulator of the Warburg effect. Mechanistically, SIRT3 mediates metabolic reprogramming by destabilizing hypoxia-inducible factor-1α (HIF1α), a transcription factor that controls glycolytic gene expression. SIRT3 loss increases reactive oxygen species production, leading to HIF1α stabilization. SIRT3 expression is reduced in human breast cancers, and its loss correlates with the upregulation of HIF1α target genes. Finally, we find that SIRT3 overexpression represses glycolysis and proliferation in breast cancer cells, providing a metabolic mechanism for tumor suppression. PMID:21397863

Redox-dependent transcriptional regulation.

PubMed

Liu, Hongjun; Colavitti, Renata; Rovira, Ilsa I; Finkel, Toren

2005-11-11

Reactive oxygen species contribute to the pathogenesis of a number of disparate disorders including tissue inflammation, heart failure, hypertension, and atherosclerosis. In response to oxidative stress, cells activate expression of a number of genes, including those required for the detoxification of reactive molecules as well as for the repair and maintenance of cellular homeostasis. In many cases, these induced genes are regulated by transcription factors whose structure, subcellular localization, or affinity for DNA is directly or indirectly regulated by the level of oxidative stress. This review summarizes the recent progress on how cellular redox status can regulate transcription-factor activity and the implications of this regulation for cardiovascular disease.

Increasing the endogenous NO level causes catalase inactivation and reactivation of intercellular apoptosis signaling specifically in tumor cells.

PubMed

Bauer, Georg

2015-12-01

Tumor cells generate extracellular superoxide anions and are protected against intercellular apoptosis-inducing HOCl- and NO/peroxynitrite signaling through the expression of membrane-associated catalase. This enzyme decomposes H2O2 and thus prevents HOCl synthesis. It efficiently interferes with NO/peroxynitrite signaling through oxidation of NO and decomposition of peroxynitrite. The regulatory potential of catalase at the crosspoint of ROS and RNS chemical biology, as well as its high local concentration on the outside of the cell membrane of tumor cells, establish tight control of intercellular signaling and thus prevent tumor cell apoptosis. Therefore, inhibition of catalase or its inactivation by singlet oxygen reactivate intercellular apoptosis-inducing signaling. Nitric oxide and peroxynitrite are connected with catalase in multiple and meaningful ways, as (i) NO can be oxidated by compound I of catalase, (ii) NO can reversibly inhibit catalase, (iii) peroxynitrite can be decomposed by catalase and (iv) the interaction between peroxynitrite and H2O2 leads to the generation of singlet oxygen that inactivates catalase. Therefore, modulation of the concentration of free NO through addition of arginine, inhibition of arginase, induction of NOS expression or inhibition of NO dioxygenase triggers an autoamplificatory biochemical cascade that is based on initial formation of singlet oxygen, amplification of superoxide anion/H2O2 and NO generation through singlet oxygen dependent stimulation of the FAS receptor and caspase-8. Finally, singlet oxygen is generated at sufficiently high concentration to inactivate protective catalase and to reactivate intercellular apoptosis-inducing ROS signaling. This regulatory network allows to establish several pathways for synergistic interactions, like the combination of modulators of NO metabolism with enhancers of superoxide anion generation, modulators of NO metabolism that act at different targets and between modulators of NO metabolism and direct catalase inhibitors. The latter aspect is explicitely studied for the interaction between catalase inhibiting acetylsalicylic acid and an NO donor. It is also shown that hybrid molecules like NO-aspirin utilize this synergistic potential. Our data open novel approaches for rational tumor therapy based on specific ROS signaling and its control in tumor cells. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Oxygen and Oxygen Toxicity: The Birth of Concepts

PubMed Central

Zhu, Hong; Traore, Kassim; Santo, Arben; Trush, Michael A.; Li, Y. Robert

2018-01-01

Molecular dioxygen (O2) is an essential element of aerobic life, yet incomplete reduction or excitation of O2 during aerobic metabolisms generates diverse oxygen-containing reactive species, commonly known as reactive oxygen species (ROS). On the one hand, ROS pose a serious threat to aerobic organisms via inducing oxidative damage to cellular constituents. On the other hand, these reactive species, when their generation is under homeostatic control, also play important physiological roles (e.g., constituting an important component of immunity and participating in redox signaling). This article defines oxygen and the key facts about oxygen, and discusses the relationship between oxygen and the emergence of early animals on Earth. The article then describes the discovery of oxygen by three historical figures and examines the birth of the concepts of oxygen toxicity and the underlying free radical mechanisms. The article ends with a brief introduction to the emerging field of ROS-mediated redox signaling and physiological responses. PMID:29707642

Bio-Physicochemical Interactions of Engineered Nanomaterials in in Vitro Cell Culture Model

DTIC Science & Technology

2014-10-11

are the important factors to study their toxicity . To investigate the potential role of oxidative stress as a mechanism of toxicity , reactive oxygen...of oxidative stress as a mechanism of toxicity , reactive oxygen species (ROS), nitric oxide (NO) lactate dehydrogenase (LDH) level and reduction in...potential role of oxidative stress as a mechanism of toxicity , reactive oxygen species (ROS), nitric oxide (NO), lactate dehydrogenase (LDH) level

Mechanical strain stimulates vasculogenesis and expression of angiogenesis guidance molecules of embryonic stem cells through elevation of intracellular calcium, reactive oxygen species and nitric oxide generation.

PubMed

Sharifpanah, Fatemeh; Behr, Sascha; Wartenberg, Maria; Sauer, Heinrich

2016-12-01

Differentiation of embryonic stem (ES) cells may be regulated by mechanical strain. Herein, signaling molecules underlying mechanical stimulation of vasculogenesis and expression of angiogenesis guidance cues were investigated in ES cell-derived embryoid bodies. Treatment of embryoid bodies with 10% static mechanical strain using a Flexercell strain system significantly increased CD31-positive vascular structures and the angiogenesis guidance molecules plexinB1, ephrin B2, neuropilin1 (NRP1), semaphorin 4D (sem4D) and robo4 as well as vascular endothelial growth factor (VEGF), fibroblast growth factor-2 (FGF-2) and platelet-derived growth factor-BB (PDGF-BB) as evaluated by Western blot and real time RT-PCR. In contrast ephrin type 4 receptor B (EphB4) expression was down-regulated upon mechanical strain, indicating an arterial-type differentiation. Robo1 protein expression was modestly increased with no change in mRNA expression. Mechanical strain increased intracellular calcium as well as reactive oxygen species (ROS) and nitric oxide (NO). Mechanical strain-induced vasculogenesis was abolished by the NOS inhibitor L-NAME, the NADPH oxidase inhibitor VAS2870, upon chelation of intracellular calcium by BAPTA as well as upon siRNA inactivation of ephrin B2, NRP1 and robo4. BAPTA blunted the strain-induced expression of angiogenic growth factors, the increase in NO and ROS as well as the expression of NRP1, sem4D and plexinB1, whereas ephrin B2, EphB4 as well as robo1 and robo4 expression were not impaired. Mechanical strain stimulates vasculogenesis of ES cells by the intracellular messengers ROS, NO and calcium as well as by upregulation of angiogenesis guidance molecules and the angiogenic growth factors VEGF, FGF-2 and PDGF-BB. Copyright © 2016 Elsevier B.V. All rights reserved.

ROLE OF NRF2 IN THE OXIDATIVE STRESS-DEPENDENT HYPERTENSION ASSOCIATED WITH THE DEPLETION OF DJ-1

PubMed Central

Cuevas, Santiago; Yang, Yu; Konkalmatt, Prasad; Asico, Laureano; Feranil, Jun; Jones, John; Villar, Van Anthony; Armando, Ines; Jose, Pedro A.

2015-01-01

Renal dopamine 2 receptor dysfunction is associated with oxidative stress and high blood pressure. We have reported that DJ-1, an oxidative stress response protein, is positively regulated by dopamine 2 receptor in the kidney. The transcription factor Nrf2 regulates the expression of several antioxidant genes. We tested the hypothesis that Nrf2 is involved in the renal DJ-1-mediated inhibition of reactive oxygen species production. We have reported that silencing dopamine 2 receptor in mouse renal proximal tubule cells decreases the expression of DJ-1. We now report that silencing DJ-1 or dopamine 2 receptor in mouse proximal tubule cells and mouse kidneys, decreases Nrf2 expression and activity and increases reactive oxygen species production; blood pressure is also increased in mice in which renal DJ-1 or dopamine 2 receptor is silenced. DJ-1−/− mice have decreased renal Nrf2 expression and activity, and increased nitro-tyrosine levels an dopamine 2 receptor d blood pressure. Silencing Nrf2 in mouse proximal tubule cells does not alter the expression of DJ-1 or dopamine 2 receptor, indicating that Nrf2 is downstream of dopamine 2 receptor and DJ-1. A Nrf2 inducer, bardoxolone, normalizes the systolic blood pressure and renal malondialdehyde levels in DJ-1−/− mice without affecting them in their wild-type littermates. Because Nrf2 ubiquitination is increased in DJ-1−/− mice, we conclude that the protective effect of DJ-1 on renal oxidative stress is mediated, in part, by preventing Nrf2 degradation. Moreover, renal dopamine 2 receptor and DJ-1 are necessary for normal Nrf2 activity to keep a normal redox balance and blood pressure. PMID:25895590

Global Analysis of Gene Expression Profiles in Physic Nut (Jatropha curcas L.) Seedlings Exposed to Salt Stress

PubMed Central

Wu, Pingzhi; Chen, Yaping; Li, Meiru; Jiang, Huawu; Wu, Guojiang

2014-01-01

Background Salt stress interferes with plant growth and production. Plants have evolved a series of molecular and morphological adaptations to cope with this abiotic stress, and overexpression of salt response genes reportedly enhances the productivity of various crops. However, little is known about the salt responsive genes in the energy plant physic nut (Jatropha curcas L.). Thus, excavate salt responsive genes in this plant are informative in uncovering the molecular mechanisms for the salt response in physic nut. Methodology/Principal Findings We applied next-generation Illumina sequencing technology to analyze global gene expression profiles of physic nut plants (roots and leaves) 2 hours, 2 days and 7 days after the onset of salt stress. A total of 1,504 and 1,115 genes were significantly up and down-regulated in roots and leaves, respectively, under salt stress condition. Gene ontology (GO) analysis of physiological process revealed that, in the physic nut, many “biological processes” were affected by salt stress, particular those categories belong to “metabolic process”, such as “primary metabolism process”, “cellular metabolism process” and “macromolecule metabolism process”. The gene expression profiles indicated that the associated genes were responsible for ABA and ethylene signaling, osmotic regulation, the reactive oxygen species scavenging system and the cell structure in physic nut. Conclusions/Significance The major regulated genes detected in this transcriptomic data were related to trehalose synthesis and cell wall structure modification in roots, while related to raffinose synthesis and reactive oxygen scavenger in leaves. The current study shows a comprehensive gene expression profile of physic nut under salt stress. The differential expression genes detected in this study allows the underling the salt responsive mechanism in physic nut with the aim of improving its salt resistance in the future. PMID:24837971

Reactive Oxygen Species Alter Autocrine and Paracrine Signaling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zangar, Richard C.; Bollinger, Nikki; Weber, Thomas J.

2011-12-01

Cytochrome P450 (P450) 3A4 (CYP3A4) is the most abundant P450 protein in human liver and intestine and is highly inducible by a variety of drugs and other compounds. The P450 catalytic cycle is known to uncouple and release reactive oxygen species (ROS), but the effects of ROS from P450 and other enzymes in the endo-plasmic reticulum have been poorly studied from the perspective of effects on cell biology. In this study, we expressed low levels of CYP3A4 in HepG2 cells, a human hepatocarcinoma cell line, and examined effects on intracellular levels of ROS and on the secretion of a varietymore » of growth factors that are important in extracellular communication. Using the redox-sensitive dye RedoxSensor red, we demonstrate that CYP3A4 expression increases levels of ROS in viable cells. A customELISA microarray platform was employed to demonstrate that expression of CYP3A4 increased secretion of amphiregulin, intracellular adhesion molecule 1, matrix metalloprotease 2, platelet-derived growth factor (PDGF), and vascular endothelial growth factor, but suppressed secretion of CD14. The antioxidant N-acetylcysteine suppressed all P450-dependent changes in protein secretion except for CD14. Quantitative RT-PCR demonstrated that changes in protein secretion were consistently associated with corresponding changes in gene expression. Inhibition of the NF-{kappa}B pathway blocked P450 effects on PDGF secretion. CYP3A4 expression also altered protein secretion in human mammary epithelial cells and C10 mouse lung cells. Overall, these results suggest that increased ROS production in the endoplasmic reticulum alters the secretion of proteins that have key roles in paracrine and autocrine signaling.« less

8-Oxo-2'-deoxyguanosine ameliorates UVB-induced skin damage in hairless mice by scavenging reactive oxygen species and inhibiting MMP expression.

PubMed

Lee, Jin-Ku; Ko, Seong-Hee; Ye, Sang-Kyu; Chung, Myung-Hee

2013-04-01

Skin is uniquely vulnerable to damage caused by reactive oxygen species (ROS), which are most commonly produced in response to ultraviolet (UV) light. ROS generated at injury sites play an important role in modulating the inflammatory response. Besides inhibiting Rac, 7,8-dihydro-8-oxo-2'-deoxyguanosine (8-oxo-dG) has also shown notable antioxidant action. We tested whether 8-oxo-dG could protect skin from UVB-induced damage by scavenging ROS. HaCaT cells and hairless mice were irradiated with 15 and 180 mJ/cm(2) narrow-spectrum UVB, respectively. ROS generation was detected through incubation with DCFDA and confocal microscopy. Western blot analyses and immunohistochemistry were performed to verify the activities of ERK, JNK, p38, ATF-2, and c-Jun, and the expression of matrix metalloproteinases (MMPs), in UVB-irradiated HaCaT cells and murine skin. Hydrogen peroxide production and protein carbonyl concentrations were measured in UVB-damaged mouse skin. MMP-1 and MMP-9 expression in UVB-irradiated HaCaT cells was measured by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). In UVB-irradiated HaCaT cells, 8-oxo-dG inhibited ROS production, subsequent activation of mitogen-activated protein kinase (MAPK), ATF-2, and c-Jun, and MMP expression. It also prevented UV-induced skin reactions in hairless mice, inhibiting the increase in protein carbonyl content, activation of MAPKs, ATF-2, and c-Jun, the increases in MMP-9 and -13 expression, and epidermal hyperplasia. 8-oxo-dG can be considered an endogenous antioxidant and its potent antioxidant activity might be a beneficial property that could be exploited to protect skin from ROS-associated photodamage. Copyright © 2013. Published by Elsevier Ireland Ltd.

Global analysis of gene expression profiles in physic nut (Jatropha curcas L.) seedlings exposed to salt stress.

PubMed

Zhang, Lin; Zhang, Chao; Wu, Pingzhi; Chen, Yaping; Li, Meiru; Jiang, Huawu; Wu, Guojiang

2014-01-01

Salt stress interferes with plant growth and production. Plants have evolved a series of molecular and morphological adaptations to cope with this abiotic stress, and overexpression of salt response genes reportedly enhances the productivity of various crops. However, little is known about the salt responsive genes in the energy plant physic nut (Jatropha curcas L.). Thus, excavate salt responsive genes in this plant are informative in uncovering the molecular mechanisms for the salt response in physic nut. We applied next-generation Illumina sequencing technology to analyze global gene expression profiles of physic nut plants (roots and leaves) 2 hours, 2 days and 7 days after the onset of salt stress. A total of 1,504 and 1,115 genes were significantly up and down-regulated in roots and leaves, respectively, under salt stress condition. Gene ontology (GO) analysis of physiological process revealed that, in the physic nut, many "biological processes" were affected by salt stress, particular those categories belong to "metabolic process", such as "primary metabolism process", "cellular metabolism process" and "macromolecule metabolism process". The gene expression profiles indicated that the associated genes were responsible for ABA and ethylene signaling, osmotic regulation, the reactive oxygen species scavenging system and the cell structure in physic nut. The major regulated genes detected in this transcriptomic data were related to trehalose synthesis and cell wall structure modification in roots, while related to raffinose synthesis and reactive oxygen scavenger in leaves. The current study shows a comprehensive gene expression profile of physic nut under salt stress. The differential expression genes detected in this study allows the underling the salt responsive mechanism in physic nut with the aim of improving its salt resistance in the future.

Modulation of IgE-dependent COX-2 gene expression by reactive oxygen species in human neutrophils.

PubMed

Vega, Antonio; Chacón, Pedro; Alba, Gonzalo; El Bekay, Rajaa; Martín-Nieto, José; Sobrino, Francisco

2006-07-01

Cyclooxygenase (COX) is a key enzyme in prostaglandin (PG) synthesis. Up-regulation of its COX-2 isoform is responsible for the increased PG release, taking place under inflammatory conditions, and also, is thought to be involved in allergic and inflammatory diseases. In the present work, we demonstrate that COX-2 expression becomes highly induced by anti-immunoglobulin E (IgE) antibodies and by antigens in human neutrophils from allergic patients. This induction was detected at mRNA and protein levels and was accompanied by a concomitant PGE(2) and thromboxane A(2) release. We also show evidence that inhibitors of reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, such as 4-(2-aminoethyl)benzenesulphonyl fluoride and 4-hydroxy-3-methoxyaceto-phenone, completely cancelled anti-IgE-induced COX-2 protein up-regulation, suggesting that this process is mediated by reactive oxygen species (ROS) derived from NADPH oxidase activity. Moreover, the mitogen-activated protein kinases (MAPKs), p38 and extracellular signal-regulated kinase, and also, the transcription factor, nuclear factor (NF)-kappaB, are involved in the up-regulation of COX-2 expression, as specific chemical inhibitors of these two kinases, such as SB203580 and PD098059, and of the NF-kappaB pathway, such as N(alpha)-benzyloxycarbonyl-l-leucyl-l-leucyl-l-leucinal, abolished IgE-dependent COX-2 induction. Evidence is also presented, using Fe(2)(+)/Cu(2)(+) ions, that hydroxyl radicals generated from hydrogen peroxide through Fenton reactions could constitute candidate modulators able to directly trigger anti-IgE-elicited COX-2 expression through MAPK and NF-kappaB pathways. Present results underscore a new role for ROS as second messengers in the modulation of COX-2 expression by human neutrophils in allergic conditions.

Platelet granule release is associated with reactive oxygen species generation during platelet storage: A direct link between platelet pro-inflammatory and oxidation states.

PubMed

Ghasemzadeh, Mehran; Hosseini, Ehteramolsadat

2017-08-01

Upon platelet stimulation with agonists, reactive oxygen species (ROS) generation enhances platelet activation and granule release. Whether ROS generation during platelet storage could be directly correlated with the expression of proinflammatory molecules and granule release has been investigated in this study. PRP-platelet concentrates were subjected to flowcytometry analysis to assess the expression of platelet activation marker, P-selectin and CD40L during storage. Intracellular ROS generation was also detected in platelet by flowcytometry using dihydrorhodamine (DHR) 123. Through the dual staining, ROS production was analyzed in either P-selectin positive or negative populations. ROS formation in platelet population was significantly increased by either TRAP (a potent agonist that induces granule release) or PMA (a classic inducer of ROS generation), while the effects of each agonists on P-selectin expression and ROS generation in platelets were comparable. Platelet storage was also associated with the increasing levels of ROS (day 0 vs. day 5; p<0.001) while this increasing pattern was directly correlated with the either expressed P-selectin or CD40L. In addition, in 5 day-stored platelets, samples with ROS levels above 40% showed significantly higher levels of P-selectin and CD40L expression. P-selectin negative population of platelet did not show significant amount of ROS. Our data demonstrated decreased levels of important platelet pro-inflammatory molecules in stored platelets with lower levels of intraplatelet ROS. However, whether quenching of ROS generation during platelet storage can attenuate adverse transfusion reactions raised by platelet pro-inflammatory status is required to be further studied. Copyright © 2017 Elsevier Ltd. All rights reserved.

A WRKY transcription factor, PcWRKY33, from Polygonum cuspidatum reduces salt tolerance in transgenic Arabidopsis thaliana.

PubMed

Bao, Wenqi; Wang, Xiaowei; Chen, Mo; Chai, Tuanyao; Wang, Hong

2018-07-01

PcWRKY33 is a transcription factor which can reduce salt tolerance by decreasing the expression of stress-related genes and increasing the cellular levels of reactive oxygen species (ROS). WRKY transcription factors play important roles in the regulation of biotic and abiotic stresses. Here, we report a group I WRKY gene from Polygonum cuspidatum, PcWRKY33, that encodes a nucleoprotein, which specifically binds to the W-box in the promoter of target genes to regulate their expression. The results from qPCR and promoter analysis show that expression of PcWRKY33 can be induced by various abiotic stresses, including NaCl and plant hormones. Overexpression of PcWRKY33 in Arabidopsis thaliana reduced tolerance to salt stress. More specifically, several physiological parameters (such as root length, seed germination rate, seedling survival rate, and chlorophyll concentration) of the transgenic lines were significantly lower than those of the wild type under salt stress. In addition, following exposure to salt stress, transgenic plants showed decreased expression of stress-related genes, a weakened ability to maintain Na + /K + homeostasis, decreased activities of reactive oxygen species- (ROS-) scavenging enzymes, and increased accumulation of ROS. Taken together, these results suggest that PcWRKY33 negatively regulates the salt tolerance in at least two ways: by down-regulating the induction of stress-related genes and by increasing the level of cellular ROS. In sum, our results indicate that PcWRKY33 is a group I WRKY transcription factor involved in abiotic stress regulation.

The calcium sensor GhCaM7 promotes cotton fiber elongation by modulating reactive oxygen species (ROS) production.

PubMed

Tang, Wenxin; Tu, Lili; Yang, Xiyan; Tan, Jiafu; Deng, Fenglin; Hao, Juan; Guo, Kai; Lindsey, Keith; Zhang, Xianlong

2014-04-01

Fiber elongation is the key determinant of fiber quality and output in cotton (Gossypium hirsutum). Although expression profiling and functional genomics provide some data, the mechanism of fiber development is still not well understood. Here, a gene encoding a calcium sensor, GhCaM7, was isolated based on its high expression level relative to other GhCaMs in fiber cells at the fast elongation stage. The level of expression of GhCaM7 in the wild-type and the fuzzless/lintless mutant correspond to the presence and absence, respectively, of fiber initials. Overexpressing GhCaM7 promotes early fiber elongation, whereas GhCaM7 suppression by RNAi delays fiber initiation and inhibits fiber elongation. Reactive oxygen species (ROS) play important roles in early fiber development. ROS induced by exogenous hydrogen peroxide (H2 O2 ) and Ca(2+) starvation promotes early fiber elongation. GhCaM7 overexpression fiber cells show increased ROS concentrations compared with the wild-type, while GhCaM7 RNAi fiber cells have reduced concentrations. Furthermore, we show that H2 O2 enhances Ca(2+) influx into the fiber and feedback-regulates the expression of GhCaM7. We conclude that GhCaM7, Ca(2+) and ROS are three important regulators involved in early fiber elongation. GhCaM7 might modulate ROS production and act as a molecular link between Ca(2+) and ROS signal pathways in early fiber development. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

Beneficial effect of resveratrol on bovine oocyte maturation and subsequent embryonic development after in vitro fertilization.

PubMed

Wang, Feng; Tian, XiuZhi; Zhang, Lu; He, ChangJiu; Ji, PengYun; Li, Yu; Tan, DunXian; Liu, GuoShi

2014-02-01

To analyze the potential beneficial effects and mechanisms of action of resveratrol on the maturation of bovine oocytes that were incubated in different concentrations of resveratrol (0.1, 1.0, or 10.0 μM) as germinal vesicle-stage oocytes. In vitro prospective study. University research laboratory. Animal models for human studies. In vitro culture in the presence of various concentrations of the antioxidant resveratrol. Parameters of hormone levels, oocyte nuclear maturation, cumulus expansion, levels of intracellular glutathione and reactive oxygen species, embryonic cleavage, blastocyst formation, gene expression associated with mature bovine oocytes and cumulus cells, and level of sirtuin 1 gene expression. Resveratrol statistically significantly increased progesterone secretion and decreased estradiol-17β secretion by cumulus cells. The elevated levels of progesterone activated the Mos/MEK/p42 mitogen-activated protein kinase (MAPK) cascade in the oocytes. At a concentration of 1.0 μM, resveratrol statistically significantly improved cumulus expansion, polar body formation, the (hatched) blastocyst rate, and the mean number of cells/blastocysts. Meanwhile, resveratrol statistically significantly reduced the level of reactive oxygen species (ROS) and increased the level of glutathione (GSH). For the first time, the expression of the sirtuin-1 gene was identified in granulosa cells, cumulus cells, oocytes, and blastocysts. Further studies revealed that resveratrol promoted sirtuin-1 gene expression. Resveratrol promoted bovine oocyte maturation and subsequent post-in vitro fertilization embryonic development by inducing progesterone secretion and an antioxidant effect, probably in a manner dependent on sirtuin-1. Copyright © 2014 American Society for Reproductive Medicine. All rights reserved.

Indoxyl sulfate potentiates endothelial dysfunction via reciprocal role for reactive oxygen species and RhoA/ROCK signaling in 5/6 nephrectomized rats.

PubMed

Chu, Shuang; Mao, Xiaodong; Guo, Hengjiang; Wang, Li; Li, Zezheng; Zhang, Yang; Wang, Yunman; Wang, Hao; Zhang, Xuemei; Peng, Wen

2017-03-01

Accumulative indoxyl sulfate (IS) retained in chronic kidney disease (CKD) can potentiate vascular endothelial dysfunction, and herein, we aim at elucidating the underlying mechanisms from the perspective of possible association between reactive oxygen species (ROS) and RhoA/ROCK pathway. IS-treated nephrectomized rats are administered with antioxidants including NADPH oxidase inhibitor apocynin, SOD analog tempol, and mitochondrion-targeted SOD mimetic mito-TEMPO to scavenge ROS, or ROCK inhibitor fasudil to obstruct RhoA/ROCK pathway. First, we find in response to IS stimulation, antioxidants treatments suppress increased aortic ROCK activity and expression levels. Additionally, ROCK blockade prevent IS-induced increased NADPH oxidase expression (mainly p22phox and p47phox), mitochondrial and intracellular ROS (superoxide and hydrogen peroxide) generation, and decreased Cu/Zn-SOD expression in thoracic aortas. Apocynin, mito-TEMPO, and tempol also reverse these markers of oxidative stress. These results suggest that IS induces excessive ROS production and ROCK activation involving a circuitous relationship in which ROS activate ROCK and ROCK promotes ROS overproduction. Finally, ROS and ROCK depletion attenuate IS-induced decrease in nitric oxide (NO) production and eNOS expression levels, and alleviate impaired vasomotor responses including increased vasocontraction to phenylephrine and decreased vasorelaxation to acetylcholine, thereby preventing cardiovascular complications accompanied by CKD. Taken together, excessive ROS derived from NADPH oxidase and mitochondria coordinate with RhoA/ROCK activation in a form of positive reciprocal relationship to induce endothelial dysfunction through disturbing endothelium-dependent NO signaling upon IS stimulation in CKD status.

Vascular Cell Adhesion Molecule-1 Expression and Signaling During Disease: Regulation by Reactive Oxygen Species and Antioxidants

PubMed Central

Marchese, Michelle E.; Abdala-Valencia, Hiam

2011-01-01

Abstract The endothelium is immunoregulatory in that inhibiting the function of vascular adhesion molecules blocks leukocyte recruitment and thus tissue inflammation. The function of endothelial cells during leukocyte recruitment is regulated by reactive oxygen species (ROS) and antioxidants. In inflammatory sites and lymph nodes, the endothelium is stimulated to express adhesion molecules that mediate leukocyte binding. Upon leukocyte binding, these adhesion molecules activate endothelial cell signal transduction that then alters endothelial cell shape for the opening of passageways through which leukocytes can migrate. If the stimulation of this opening is blocked, inflammation is blocked. In this review, we focus on the endothelial cell adhesion molecule, vascular cell adhesion molecule-1 (VCAM-1). Expression of VCAM-1 is induced on endothelial cells during inflammatory diseases by several mediators, including ROS. Then, VCAM-1 on the endothelium functions as both a scaffold for leukocyte migration and a trigger of endothelial signaling through NADPH oxidase-generated ROS. These ROS induce signals for the opening of intercellular passageways through which leukocytes migrate. In several inflammatory diseases, inflammation is blocked by inhibition of leukocyte binding to VCAM-1 or by inhibition of VCAM-1 signal transduction. VCAM-1 signal transduction and VCAM-1-dependent inflammation are blocked by antioxidants. Thus, VCAM-1 signaling is a target for intervention by pharmacological agents and by antioxidants during inflammatory diseases. This review discusses ROS and antioxidant functions during activation of VCAM-1 expression and VCAM-1 signaling in inflammatory diseases. Antioxid. Redox Signal. 15, 1607–1638. PMID:21050132

Alpha lipoic acid selectively inhibits proliferation and adhesion to fibronectin of v-H-ras-transformed 3Y1 cells.

PubMed

Yamasaki, Masao; Iwase, Masahiro; Kawano, Kazuo; Sakakibara, Yoichi; Suiko, Masahito; Nishiyama, Kazuo

2012-05-01

Here, we focused on the effects of racemic α-lipoic acid on proliferation and adhesion properties of 3Y1 rat fibroblasts and the v-H-ras-transformed derivative, HR-3Y1-2 cells. Racemic α-lipoic acid inhibited proliferation of HR-3Y1-2 but not 3Y1 cells at 0.3 and 1.0 mM. R-(+)-α-lipoic acid also inhibited proliferation of HR-3Y1-2 cells equivalent to that of racemic α-lipoic acid. In addition, racemic α-lipoic acid decreased intracellular reactive oxygen species levels in HR-3Y1 cells but not 3Y1 cells. Next, we evaluated the effects of racemic α-lipoic acid on cell adhesion to fibronectin. The results indicated that racemic α-lipoic acid decreased adhesive ability of HR-3Y1-2 cells to fibronectin-coated plates. As blocking antibody experiment revealed that β1-integrin plays a key role in cell adhesion in this experimental system, the effects of racemic α-lipoic acid on the expression of β1-integrin were examined. The results indicated that racemic α-lipoic acid selectively downregulated the expression of cell surface β1-integrin expression in HR-3Y1-2 cells. Intriguingly, exogenous hydrogen peroxide upregulated cell surface β1-integrin expression in 3Y1 cells. Taken together, these data suggest that reduction of intracellular reactive oxygen species levels by α-lipoic acid could be an effective means of ameliorating abnormal growth and adhesive properties in v-H-ras transformed cells.

Convergence of the transcriptional responses to heat shock and singlet oxygen stresses.

PubMed

Dufour, Yann S; Imam, Saheed; Koo, Byoung-Mo; Green, Heather A; Donohue, Timothy J

2012-09-01

Cells often mount transcriptional responses and activate specific sets of genes in response to stress-inducing signals such as heat or reactive oxygen species. Transcription factors in the RpoH family of bacterial alternative σ factors usually control gene expression during a heat shock response. Interestingly, several α-proteobacteria possess two or more paralogs of RpoH, suggesting some functional distinction. We investigated the target promoters of Rhodobacter sphaeroides RpoH(I) and RpoH(II) using genome-scale data derived from gene expression profiling and the direct interactions of each protein with DNA in vivo. We found that the RpoH(I) and RpoH(II) regulons have both distinct and overlapping gene sets. We predicted DNA sequence elements that dictate promoter recognition specificity by each RpoH paralog. We found that several bases in the highly conserved TTG in the -35 element are important for activity with both RpoH homologs; that the T-9 position, which is over-represented in the RpoH(I) promoter sequence logo, is critical for RpoH(I)-dependent transcription; and that several bases in the predicted -10 element were important for activity with either RpoH(II) or both RpoH homologs. Genes that are transcribed by both RpoH(I) and RpoH(II) are predicted to encode for functions involved in general cell maintenance. The functions specific to the RpoH(I) regulon are associated with a classic heat shock response, while those specific to RpoH(II) are associated with the response to the reactive oxygen species, singlet oxygen. We propose that a gene duplication event followed by changes in promoter recognition by RpoH(I) and RpoH(II) allowed convergence of the transcriptional responses to heat and singlet oxygen stress in R. sphaeroides and possibly other bacteria.

An NADPH Oxidase RBOH Functions in Rice Roots during Lysigenous Aerenchyma Formation under Oxygen-Deficient Conditions

PubMed Central

Yoshioka, Miki; Fukazawa, Aya; Nishizawa, Naoko K.

2017-01-01

Reactive oxygen species (ROS) produced by the NADPH oxidase, respiratory burst oxidase homolog (RBOH), trigger signal transduction in diverse biological processes in plants. However, the functions of RBOH homologs in rice (Oryza sativa) and other gramineous plants are poorly understood. Ethylene induces the formation of lysigenous aerenchyma, which consists of internal gas spaces created by programmed cell death of cortical cells, in roots of gramineous plants under oxygen-deficient conditions. Here, we report that, in rice, one RBOH isoform (RBOHH) has a role in ethylene-induced aerenchyma formation in roots. Induction of RBOHH expression under oxygen-deficient conditions was greater in cortical cells than in cells of other root tissues. In addition, genes encoding group I calcium-dependent protein kinases (CDPK5 and CDPK13) were strongly expressed in root cortical cells. Coexpression of RBOHH with CDPK5 or CDPK13 induced ROS production in Nicotiana benthamiana leaves. Inhibitors of RBOH activity or cytosolic calcium influx suppressed ethylene-induced aerenchyma formation. Moreover, knockout of RBOHH by CRISPR/Cas9 reduced ROS accumulation and inducible aerenchyma formation in rice roots. These results suggest that RBOHH-mediated ROS production, which is stimulated by CDPK5 and/or CDPK13, is essential for ethylene-induced aerenchyma formation in rice roots under oxygen-deficient conditions. PMID:28351990

Influence of reactive oxygen species on the sterilization of microbes

USDA-ARS?s Scientific Manuscript database

The influence of reactive oxygen species on living cells, including various microbes, is discussed. A sterilization experiment with bacterial endospores reveals that an argoneoxygen plasma jet very effectively kills endospores of Bacillus atrophaeus (ATCC 9372), thereby indicating that oxygen radic...

A quantum protective mechanism in photosynthesis

NASA Astrophysics Data System (ADS)

Marais, Adriana; Sinayskiy, Ilya; Petruccione, Francesco; van Grondelle, Rienk

2015-03-01

Since the emergence of oxygenic photosynthesis, living systems have developed protective mechanisms against reactive oxygen species. During charge separation in photosynthetic reaction centres, triplet states can react with molecular oxygen generating destructive singlet oxygen. The triplet product yield in bacteria is observed to be reduced by weak magnetic fields. Reaction centres from plants' photosystem II share many features with bacterial reaction centres, including a high-spin iron whose function has remained obscure. To explain observations that the magnetic field effect is reduced by the iron, we propose that its fast-relaxing spin plays a protective role in photosynthesis by generating an effective magnetic field. We consider a simple model of the system, derive an analytical expression for the effective magnetic field and analyse the resulting triplet yield reduction. The protective mechanism is robust for realistic parameter ranges, constituting a clear example of a quantum effect playing a macroscopic role vital for life.

A quantum protective mechanism in photosynthesis.

PubMed

Marais, Adriana; Sinayskiy, Ilya; Petruccione, Francesco; van Grondelle, Rienk

2015-03-03

Since the emergence of oxygenic photosynthesis, living systems have developed protective mechanisms against reactive oxygen species. During charge separation in photosynthetic reaction centres, triplet states can react with molecular oxygen generating destructive singlet oxygen. The triplet product yield in bacteria is observed to be reduced by weak magnetic fields. Reaction centres from plants' photosystem II share many features with bacterial reaction centres, including a high-spin iron whose function has remained obscure. To explain observations that the magnetic field effect is reduced by the iron, we propose that its fast-relaxing spin plays a protective role in photosynthesis by generating an effective magnetic field. We consider a simple model of the system, derive an analytical expression for the effective magnetic field and analyse the resulting triplet yield reduction. The protective mechanism is robust for realistic parameter ranges, constituting a clear example of a quantum effect playing a macroscopic role vital for life.

Catalases Are NAD(P)H-Dependent Tellurite Reductases

PubMed Central

Calderón, Iván L.; Arenas, Felipe A.; Pérez, José Manuel; Fuentes, Derie E.; Araya, Manuel A.; Saavedra, Claudia P.; Tantaleán, Juan C.; Pichuantes, Sergio E.; Youderian, Philip A.; Vásquez, Claudio C.

2006-01-01

Reactive oxygen species damage intracellular targets and are implicated in cancer, genetic disease, mutagenesis, and aging. Catalases are among the key enzymatic defenses against one of the most physiologically abundant reactive oxygen species, hydrogen peroxide. The well-studied, heme-dependent catalases accelerate the rate of the dismutation of peroxide to molecular oxygen and water with near kinetic perfection. Many catalases also bind the cofactors NADPH and NADH tenaciously, but, surprisingly, NAD(P)H is not required for their dismutase activity. Although NAD(P)H protects bovine catalase against oxidative damage by its peroxide substrate, the catalytic role of the nicotinamide cofactor in the function of this enzyme has remained a biochemical mystery to date. Anions formed by heavy metal oxides are among the most highly reactive, natural oxidizing agents. Here, we show that a natural isolate of Staphylococcus epidermidis resistant to tellurite detoxifies this anion thanks to a novel activity of its catalase, and that a subset of both bacterial and mammalian catalases carry out the NAD(P)H-dependent reduction of soluble tellurite ion (TeO3 2−) to the less toxic, insoluble metal, tellurium (Te°), in vitro. An Escherichia coli mutant defective in the KatG catalase/peroxidase is sensitive to tellurite, and expression of the S. epidermidis catalase gene in a heterologous E. coli host confers increased resistance to tellurite as well as to hydrogen peroxide in vivo, arguing that S. epidermidis catalase provides a physiological line of defense against both of these strong oxidizing agents. Kinetic studies reveal that bovine catalase reduces tellurite with a low Michaelis-Menten constant, a result suggesting that tellurite is among the natural substrates of this enzyme. The reduction of tellurite by bovine catalase occurs at the expense of producing the highly reactive superoxide radical. PMID:17183702

Catalases are NAD(P)H-dependent tellurite reductases.

PubMed

Calderón, Iván L; Arenas, Felipe A; Pérez, José Manuel; Fuentes, Derie E; Araya, Manuel A; Saavedra, Claudia P; Tantaleán, Juan C; Pichuantes, Sergio E; Youderian, Philip A; Vásquez, Claudio C

2006-12-20

Reactive oxygen species damage intracellular targets and are implicated in cancer, genetic disease, mutagenesis, and aging. Catalases are among the key enzymatic defenses against one of the most physiologically abundant reactive oxygen species, hydrogen peroxide. The well-studied, heme-dependent catalases accelerate the rate of the dismutation of peroxide to molecular oxygen and water with near kinetic perfection. Many catalases also bind the cofactors NADPH and NADH tenaciously, but, surprisingly, NAD(P)H is not required for their dismutase activity. Although NAD(P)H protects bovine catalase against oxidative damage by its peroxide substrate, the catalytic role of the nicotinamide cofactor in the function of this enzyme has remained a biochemical mystery to date. Anions formed by heavy metal oxides are among the most highly reactive, natural oxidizing agents. Here, we show that a natural isolate of Staphylococcus epidermidis resistant to tellurite detoxifies this anion thanks to a novel activity of its catalase, and that a subset of both bacterial and mammalian catalases carry out the NAD(P)H-dependent reduction of soluble tellurite ion (TeO(3)(2-)) to the less toxic, insoluble metal, tellurium (Te(o)), in vitro. An Escherichia coli mutant defective in the KatG catalase/peroxidase is sensitive to tellurite, and expression of the S. epidermidis catalase gene in a heterologous E. coli host confers increased resistance to tellurite as well as to hydrogen peroxide in vivo, arguing that S. epidermidis catalase provides a physiological line of defense against both of these strong oxidizing agents. Kinetic studies reveal that bovine catalase reduces tellurite with a low Michaelis-Menten constant, a result suggesting that tellurite is among the natural substrates of this enzyme. The reduction of tellurite by bovine catalase occurs at the expense of producing the highly reactive superoxide radical.

Catalase, a remarkable enzyme: targeting the oldest antioxidant enzyme to find a new cancer treatment approach.

PubMed

Glorieux, Christophe; Calderon, Pedro Buc

2017-09-26

This review is centered on the antioxidant enzyme catalase and will present different aspects of this particular protein. Among them: historical discovery, biological functions, types of catalases and recent data with regard to molecular mechanisms regulating its expression. The main goal is to understand the biological consequences of chronic exposure of cells to hydrogen peroxide leading to cellular adaptation. Such issues are of the utmost importance with potential therapeutic extrapolation for various pathologies. Catalase is a key enzyme in the metabolism of H2O2 and reactive nitrogen species, and its expression and localization is markedly altered in tumors. The molecular mechanisms regulating the expression of catalase, the oldest known and first discovered antioxidant enzyme, are not completely elucidated. As cancer cells are characterized by an increased production of reactive oxygen species (ROS) and a rather altered expression of antioxidant enzymes, these characteristics represent an advantage in terms of cell proliferation. Meanwhile, they render cancer cells particularly sensitive to an oxidant insult. In this context, targeting the redox status of cancer cells by modulating catalase expression is emerging as a novel approach to potentiate chemotherapy.

Differences in neural crest sensitivity to ethanol account for the infrequency of anterior segment defects in the eye compared with craniofacial anomalies in a zebrafish model of fetal alcohol syndrome.

PubMed

Eason, Jessica; Williams, Antionette L; Chawla, Bahaar; Apsey, Christian; Bohnsack, Brenda L

2017-09-01

Ethanol (ETOH) exposure during pregnancy is associated with craniofacial and neurologic abnormalities, but infrequently disrupts the anterior segment of the eye. In these studies, we used zebrafish to investigate differences in the teratogenic effect of ETOH on craniofacial, periocular, and ocular neural crest. Zebrafish eye and neural crest development was analyzed by means of live imaging, TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) assay, immunostaining, detection of reactive oxygen species, and in situ hybridization. Our studies demonstrated that foxd3-positive neural crest cells in the periocular mesenchyme and developing eye were less sensitive to ETOH than sox10-positive craniofacial neural crest cells that form the pharyngeal arches and jaw. ETOH increased apoptosis in the retina, but did not affect survival of periocular and ocular neural crest cells. ETOH also did not increase reactive oxygen species within the eye. In contrast, ETOH increased ventral neural crest apoptosis and reactive oxygen species production in the facial mesenchyme. In the eye and craniofacial region, sod2 showed high levels of expression in the anterior segment and in the setting of Sod2 knockdown, low levels of ETOH decreased migration of foxd3-positive neural crest cells into the developing eye. However, ETOH had minimal effect on the periocular and ocular expression of transcription factors (pitx2 and foxc1) that regulate anterior segment development. Neural crest cells contributing to the anterior segment of the eye exhibit increased ability to withstand ETOH-induced oxidative stress and apoptosis. These studies explain the rarity of anterior segment dysgenesis despite the frequent craniofacial abnormalities in fetal alcohol syndrome. Birth Defects Research 109:1212-1227, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Molecular Steps in the Immune Signaling Pathway Evoked by Plant Elicitor Peptides: Ca2+-Dependent Protein Kinases, Nitric Oxide, and Reactive Oxygen Species Are Downstream from the Early Ca2+ Signal1[OPEN

PubMed Central

Ma, Yi; Zhao, Yichen; Walker, Robin K.; Berkowitz, Gerald A.

2013-01-01

Endogenous plant elicitor peptides (Peps) can act to facilitate immune signaling and pathogen defense responses. Binding of these peptides to the Arabidopsis (Arabidopsis thaliana) plasma membrane-localized Pep receptors (PEPRs) leads to cytosolic Ca2+ elevation, an early event in a signaling cascade that activates immune responses. This immune response includes the amplification of signaling evoked by direct perception of pathogen-associated molecular patterns by plant cells under assault. Work included in this report further characterizes the Pep immune response and identifies new molecular steps in the signal transduction cascade. The PEPR coreceptor BRASSINOSTEROID-INSENSITIVE1 Associated Kinase1 contributes to generation of the Pep-activated Ca2+ signal and leads to increased defense gene expression and resistance to a virulent bacterial pathogen. Ca2+-dependent protein kinases (CPKs) decode the Ca2+ signal, also facilitating defense gene expression and enhanced resistance to the pathogen. Nitric oxide and reduced nicotinamide adenine dinucleotide phosphate oxidase-dependent reactive oxygen species generation (due to the function of Respiratory Burst Oxidase Homolog proteins D and F) are also involved downstream from the Ca2+ signal in the Pep immune defense signal transduction cascade, as is the case with BRASSINOSTEROID-INSENSITIVE1 Associated Kinase1 and CPK5, CPK6, and CPK11. These steps of the pathogen defense response are required for maximal Pep immune activation that limits growth of a virulent bacterial pathogen in the plant. We find a synergism between function of the PEPR and Flagellin Sensing2 receptors in terms of both nitric oxide and reactive oxygen species generation. Presented results are also consistent with the involvement of the secondary messenger cyclic GMP and a cyclic GMP-activated Ca2+-conducting channel in the Pep immune signaling pathway. PMID:24019427

Diterpenoid natural compound C4 (Crassin) exerts cytostatic effects on triple-negative breast cancer cells via a pathway involving reactive oxygen species.

PubMed

Richards, Cathy E; Vellanki, Sri H; Smith, Yvonne E; Hopkins, Ann M

2018-02-01

Triple-negative breast cancers (TNBC) lack expression of three common cell surface receptors, i.e., estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER2). Accordingly, TNBCs are associated with fewer treatment options and a relatively poor prognosis. Having screened a National Cancer Institute natural compound library, the purpose of this study was to investigate the bioactivity of compound C4 (Crassin) in TNBC cells. Cell viability assays were performed in two TNBC cell lines, MDA-MB-231 and 4T1, following C4 treatment in the presence or absence of the antioxidant N-acetyl-L-cysteine (NAC). Phosphorylation of Akt and ERK was assessed by Western blotting. Apoptosis, necrosis, autophagy, necroptosis, ferroptosis and cytostasis assays were performed to explain viability deficits resulting from C4 exposure. We found that the viability of the TNBC cells tested decreased in a concentration- and time-dependent fashion following C4 treatment. This decrease coincided with an unexpected increase in the expression of the cell survival effectors pAkt and pERK. In addition, we found that both the decreased cell viability and the increased pAkt/pERK levels could be rescued by the antioxidant NAC, suggesting a central role for reactive oxygen species (ROS) in the mechanism of action of C4. Necrosis, apoptosis, necroptosis and ferroptosis could be ruled out as cell death mechanisms. Instead, we found that C4 induced cytostasis downstream of ROS activation. Finally, we observed a synergistic effect between C4 and the chemotherapeutic drug doxorubicin in TNBC cells. From our in vitro data we conclude that C4 exerts cytostatic effects on triple-negative breast cancer cells via a pathway involving reactive oxygen species. Its potential value in combination with cytotoxic therapies merits deeper investigation in pre-clinical models.

Using Paraquat to Generate Anion Free Radicals and Hydrogen Peroxide in "In Vitro": Antioxidant Effect of Vitamin E--A Procedure to Teach Theoretical and Experimental Principles of Reactive Oxygen Species Biochemistry

ERIC Educational Resources Information Center

Jimenez-Del-Rio, Marlene; Suarez-Cedeno, Gerson; Velez-Pardo, Carlos

2010-01-01

The theoretical basis of reactive oxygen species and their impact on health issues are relatively easy to understand by biomedical students. The detection of reactive oxygen species requires expensive equipment, the procedures are time consuming and costly, and the results are hard to interpret. Moreover, cause-and-effect relationships in the…

Impact of trans-resveratrol-sulfates and -glucuronides on endothelial nitric oxide synthase activity, nitric oxide release and intracellular reactive oxygen species.

PubMed

Ladurner, Angela; Schachner, Daniel; Schueller, Katharina; Pignitter, Marc; Heiss, Elke H; Somoza, Veronika; Dirsch, Verena M

2014-10-17

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a polyphenolic natural product mainly present in grape skin, berries and peanuts. In the vasculature resveratrol is thought to boost endothelial function by increasing endothelial nitric oxide synthase (eNOS) expression, by enhancing eNOS activity, and by reduction of reactive oxygen species (ROS) levels. Recent studies show that dietary resveratrol is metabolized in the liver and intestine into resveratrol-sulfate and -glucuronide derivatives questioning the relevance of multiple reported mechanistic in vitro data on resveratrol. In this study, we compare side by side different physiologically relevant resveratrol metabolites (resveratrol sulfates- and -glucuronides) and their parent compound in their influence on eNOS enzyme activity, endothelial NO release, and intracellular ROS levels. In contrast to resveratrol, none of the tested resveratrol metabolites elevated eNOS enzyme activity and endothelial NO release or affected intracellular ROS levels, leaving the possibility that not tested metabolites are active and able to explain in vivo findings.

Salicin, an extract from white willow bark, inhibits angiogenesis by blocking the ROS-ERK pathways.

PubMed

Kong, Chang-Seok; Kim, Ka-Hyun; Choi, Jae-Sun; Kim, Ja-Eun; Park, Chan; Jeong, Joo-Won

2014-08-01

Salicin has been studied as a potent antiinflammatory agent. Angiogenesis is an essential process for tumor progression, and negative regulation of angiogenesis provides a good strategy for antitumor therapy. However, the potential medicinal value of salicin on antitumorigenic and antiangiogenic effects remain unexplored. In this study, we examined the antitumorigenic and antiangiogenic activity of salicin and its underlying mechanism of action. Salicin suppressed the angiogenic activity of endothelial cells, such as migration, tube formation, and sprouting from an aorta. Moreover, salicin reduced reactive oxygen species production and activation of the extracellular signal-regulated kinase pathway. The expression of vascular endothelial growth factor was also decreased by salicin in endothelial cells. When the salicin was administered to mice, salicin inhibited tumor growth and angiogenesis in a mouse tumor model. Taken together, salicin targets the signaling pathways mediated by reactive oxygen species and extracellular signal-regulated kinase, providing new perspectives into a potent therapeutic agent for hypervascularized tumors. Copyright © 2014 John Wiley & Sons, Ltd.

Improved stress tolerance and productivity in transgenic rice plants constitutively expressing the Oryza sativa glutathione synthetase OsGS under paddy field conditions.

PubMed

Park, Seong-Im; Kim, Young-Saeng; Kim, Jin-Ju; Mok, Ji-Eun; Kim, Yul-Ho; Park, Hyang-Mi; Kim, Il-Sup; Yoon, Ho-Sung

2017-08-01

Reactive oxygen species, which increase under various environmental stresses, have deleterious effects on plants. An important antioxidant, glutathione, is used to detoxify reactive oxygen species in plant cells and is mainly produced by two enzymes: gamma-glutamylcysteine synthetase (γ-ECS) and glutathione synthetase (GS). To evaluate the functional roles of the glutathione synthetase gene (OsGS) in rice, we generated four independent transgenic rice plants (TG1-TG4) that overexpressed OsGS under the control of the constitutively expressed OsCc1 promoter. When grown under natural paddy field conditions, the TG rice plants exhibited greater growth development, higher chlorophyll content, and higher GSH/GSSH ratios than control wild-type (WT) rice plants. Subsequently, the TG rice plants enhanced redox homeostasis by preventing hydroperoxide-mediated membrane damage, which improved their adaptation to environmental stresses. As a result, TG rice plants improved rice grain yield and total biomass following increases in panicle number and number of spikelets per panicle, despite differences in climate during the cultivation periods of 2014 and 2015. Overall, our results indicate that OsGS overexpression improved redox homeostasis by enhancing the glutathione pool, which resulted in greater tolerance to environmental stresses in the paddy fields. Copyright © 2017. Published by Elsevier GmbH.

Shikonin Isolated from Lithospermum erythrorhizon Downregulates Proinflammatory Mediators in Lipopolysaccharide-Stimulated BV2 Microglial Cells by Suppressing Crosstalk between Reactive Oxygen Species and NF-κB.

PubMed

Prasad, Rajapaksha Gedara; Choi, Yung Hyun; Kim, Gi-Young

2015-03-01

According to the expansion of lifespan, neuronal disorder based on inflammation has been social problem. Therefore, we isolated shikonin from Lithospermum erythrorhizon and evaluated anti-inflammatory effects of shikonin in lipopolysaccharide (LSP)-stimulated BV2 microglial cells. Shikonin dose-dependently inhibits the expression of the proinflammatory mediators, nitric oxide (NO), prostaglandin E2 (PGE2), and tumor necrosis factor-α (TNF-α) as well as their main regulatory genes and products such as inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), and TNF-α in LPS-stimulated BV2 microglial cells. Additionally, shikonin suppressed the LPS-induced DNA-binding activity of nuclear factor-κB (NF-κB) to regulate the key regulatory genes of the proinflammatory mediators, such as iNOS, COX-2, and TNF-α, accompanied with downregulation of reactive oxygen species (ROS) generation. The results indicate that shikonin may downregulate the expression of proinflammatory genes involved in the synthesis of NO, PGE2, and TNF-α in LPS-treated BV2 microglial cells by suppressing ROS and NF-κB. Taken together, our results revealed that shikonin exerts downregulation of proinflammatory mediators by interference the ROS and NF-κB signaling pathway.

Shikonin Isolated from Lithospermum erythrorhizon Downregulates Proinflammatory Mediators in Lipopolysaccharide-Stimulated BV2 Microglial Cells by Suppressing Crosstalk between Reactive Oxygen Species and NF-κB

PubMed Central

Prasad, Rajapaksha Gedara; Choi, Yung Hyun; Kim, Gi-Young

2015-01-01

According to the expansion of lifespan, neuronal disorder based on inflammation has been social problem. Therefore, we isolated shikonin from Lithospermum erythrorhizon and evaluated anti-inflammatory effects of shikonin in lipopolysaccharide (LSP)-stimulated BV2 microglial cells. Shikonin dose-dependently inhibits the expression of the proinflammatory mediators, nitric oxide (NO), prostaglandin E2 (PGE2), and tumor necrosis factor-α (TNF-α) as well as their main regulatory genes and products such as inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), and TNF-α in LPS-stimulated BV2 microglial cells. Additionally, shikonin suppressed the LPS-induced DNA-binding activity of nuclear factor-κB (NF-κB) to regulate the key regulatory genes of the proinflammatory mediators, such as iNOS, COX-2, and TNF-α, accompanied with downregulation of reactive oxygen species (ROS) generation. The results indicate that shikonin may downregulate the expression of proinflammatory genes involved in the synthesis of NO, PGE2, and TNF-α in LPS-treated BV2 microglial cells by suppressing ROS and NF-κB. Taken together, our results revealed that shikonin exerts downregulation of proinflammatory mediators by interference the ROS and NF-κB signaling pathway. PMID:25767678

Antioxidant and Anti-Inflammatory Effects in RAW264.7 Macrophages of Malvidin, a Major Red Wine Polyphenol

PubMed Central

Bognar, Eszter; Sarszegi, Zsolt; Szabo, Aliz; Debreceni, Balazs; Kalman, Nikoletta; Tucsek, Zsuzsanna; Sumegi, Balazs; Gallyas, Ferenc

2013-01-01

Background Red wine polyphenols can prevent cardiovascular and inflammatory diseases. Resveratrol, the most extensively studied constituent, is unlikely to solely account for these beneficial effects because of its rather low abundance and bioavailability. Malvidin is far the most abundant polyphenol in red wine; however, very limited data are available about its effect on inflammatory processes and kinase signaling pathways. Methods & Findings The present study was carried out by using RAW 264.7 macrophages stimulated by bacterial lipopolysaccharide in the presence and absence of malvidin. From the cells, activation of nuclear factor-kappaB, mitogen-activated protein kinase, protein kinase B/Akt and poly ADP-ribose polymerase, reactive oxygen species production, mitogen-activated protein kinase phosphatase-1 expression and mitochondrial depolarization were determined. We found that malvidin attenuated lipopolysaccharide-induced nuclear factor-kappaB, poly ADP-ribose polymerase and mitogen-activated protein kinase activation, reactive oxygen species production and mitochondrial depolarization, while upregulated the compensatory processes; mitogen-activated protein kinase phosphatase-1 expression and Akt activation. Conclusions These effects of malvidin may explain the previous findings and at least partially account for the positive effects of moderate red wine consumption on inflammation-mediated chronic maladies such as obesity, diabetes, hypertension and cardiovascular disease. PMID:23755222

Constitutive NF-κB activation and tumor-growth promotion by Romo1-mediated reactive oxygen species production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chung, Jin Sil; Lee, Sora; Yoo, Young Do, E-mail: ydy1130@korea.ac.kr

2014-08-08

Highlights: • Romo1 expression is required for constitutive nuclear DNA-binding activity of NF-κB. • Romo1 depletion suppresses tumor growth in vivo. • Romo1 presents a potential therapeutic target for diseases. - Abstract: Deregulation of nuclear factor-κB (NF-κB) and related pathways contribute to tumor cell proliferation and invasion. Mechanisms for constitutive NF-κB activation are not fully explained; however, the underlying defects appear to generate and maintain pro-oxidative conditions. In hepatocellular carcinoma (HCC) tissues, up-regulation of reactive oxygen species modulator 1 (Romo1) correlates positively with tumor size. In the present study, we showed that Romo1 expression is required to maintain constitutive nuclearmore » DNA-binding activity of NF-κB and transcriptional activity through constitutive IκBα phosphorylation. Overexpression of Romo1 promoted p65 nuclear translocation and DNA-binding activity. We also show that Romo1 depletion suppressed anchorage-independent colony formation by HCC cells and suppressed tumor growth in vivo. Based on these findings, Romo1 may be a principal regulatory factor in the maintenance of constitutive NF-κB activation in tumor cells. In the interest of anti-proliferative treatments for cancer, Romo1 may also present a productive target for drug development.« less

The Effects of New Alibernet Red Wine Extract on Nitric Oxide and Reactive Oxygen Species Production in Spontaneously Hypertensive Rats

PubMed Central

Kondrashov, Alexey; Vranková, Stanislava; Dovinová, Ima; Ševčík, Rudolf; Parohová, Jana; Barta, Andrej; Pecháňová, Olga; Kovacsová, Maria

2012-01-01

We aimed to perform a chemical analysis of both Alibernet red wine and an alcohol-free Alibernet red wine extract (AWE) and to investigate the effects of AWE on nitric oxide and reactive oxygen species production as well as blood pressure development in normotensive Wistar Kyoto (WKY) and spontaneously hypertensive rats (SHRs). Total antioxidant capacity together with total phenolic and selected mineral content was measured in wine and AWE. Young 6-week-old male WKY and SHR were treated with AWE (24,2 mg/kg/day) for 3 weeks. Total NOS and SOD activities, eNOS and SOD1 protein expressions, and superoxide production were determined in the tissues. Both antioxidant capacity and phenolic content were significantly higher in AWE compared to wine. The AWE increased NOS activity in the left ventricle, aorta, and kidney of SHR, while it did not change NOS activity in WKY rats. Similarly, increased SOD activity in the plasma and left ventricle was observed in SHR only. There were no changes in eNOS and SOD1 expressions. In conclusion, phenolics and minerals included in AWE may contribute directly to increased NOS and SOD activities of SHR. Nevertheless, 3 weeks of AWE treatment failed to affect blood pressure of SHR. PMID:22720118

Silymarin attenuated paraquat-induced cytotoxicity in macrophage by regulating Trx/TXNIP complex, inhibiting NLRP3 inflammasome activation and apoptosis.

PubMed

Liu, Zhenning; Sun, Mingli; Wang, Yu; Zhang, Lichun; Zhao, Hang; Zhao, Min

2018-02-01

Oxidative stress and inflammation are involved in paraquat-induced cytotoxicity. Silymarin can exert a potent antioxidative and anti-inflammatory effect in various pathophysiological processes. The aim of this current study is to explore the protective effect and potential mechanism of silymarin in paraquat-induced macrophage injury. Cells were pretreated with different doses of silymarin for 3h before exposure to paraquat. At 24h after exposure to paraquat, the paraquat-induced cytotoxicity to macrophage was measured via the MTT assay and LDH release. The levels of intracellular reactive oxygen species, GSH-Px, SOD, and lipid peroxidation product malondialdehyde were measured to evaluate the oxidative effect of paraquat. NLRP3 inflammasome and cytokines secretion in macrophage exposed to paraquat at 24h were measured via immunofluorescence microscopy, western blot or Elisa. Our results revealed that paraquat could dramatically cause cytotoxicity and reactive oxygen species generation, enhance TXNIP expression, and induce NLRP3 inflammasome activation and cytokines secretion. The pretreatment with silymarin could remarkably reduce the cytotoxicity, promote the expression of Trx and antioxidant enzymes, and suppress the TXNIP and NLRP3 inflammasome activation. In conclusion, silymarin attenuated paraquat-induced cytotoxicity in macrophage by inhibiting oxidative stress, NLRP3 inflammasome activation, cytokines secretion and apoptosis. Copyright © 2017 Elsevier Ltd. All rights reserved.

High salt-induced excess reactive oxygen species production resulted in heart tube malformation during gastrulation.

PubMed

Gao, Lin-Rui; Wang, Guang; Zhang, Jing; Li, Shuai; Chuai, Manli; Bao, Yongping; Hocher, Berthold; Yang, Xuesong

2018-09-01

An association has been proved between high salt consumption and cardiovascular mortality. In vertebrates, the heart is the first functional organ to be formed. However, it is not clear whether high-salt exposure has an adverse impact on cardiogenesis. Here we report high-salt exposure inhibited basement membrane breakdown by affecting RhoA, thus disturbing the expression of Slug/E-cadherin/N-cadherin/Laminin and interfering with mesoderm formation during the epithelial-mesenchymal transition(EMT). Furthermore, the DiI + cell migration trajectory in vivo and scratch wound assays in vitro indicated that high-salt exposure restricted cell migration of cardiac progenitors, which was caused by the weaker cytoskeleton structure and unaltered corresponding adhesion junctions at HH7. Besides, down-regulation of GATA4/5/6, Nkx2.5, TBX5, and Mef2c and up-regulation of Wnt3a/β-catenin caused aberrant cardiomyocyte differentiation at HH7 and HH10. High-salt exposure also inhibited cell proliferation and promoted apoptosis. Most importantly, our study revealed that excessive reactive oxygen species(ROS)generated by high salt disturbed the expression of cardiac-related genes, detrimentally affecting the above process including EMT, cell migration, differentiation, cell proliferation and apoptosis, which is the major cause of malformation of heart tubes. © 2018 Wiley Periodicals, Inc.

Irradiation of skin with visible light induces reactive oxygen species and matrix-degrading enzymes.

PubMed

Liebel, Frank; Kaur, Simarna; Ruvolo, Eduardo; Kollias, Nikiforos; Southall, Michael D

2012-07-01

Daily skin exposure to solar radiation causes cells to produce reactive oxygen species (ROS), which are a primary factor in skin damage. Although the contribution of the UV component to skin damage has been established, few studies have examined the effects of non-UV solar radiation on skin physiology. Solar radiation comprises <10% of UV, and thus the purpose of this study was to examine the physiological response of skin to visible light (400-700 nm). Irradiation of human skin equivalents with visible light induced production of ROS, proinflammatory cytokines, and matrix metalloproteinase (MMP)-1 expression. Commercially available sunscreens were found to have minimal effects on reducing visible light-induced ROS, suggesting that UVA/UVB sunscreens do not protect the skin from visible light-induced responses. Using clinical models to assess the generation of free radicals from oxidative stress, higher levels of free radical activity were found after visible light exposure. Pretreatment with a photostable UVA/UVB sunscreen containing an antioxidant combination significantly reduced the production of ROS, cytokines, and MMP expression in vitro, and decreased oxidative stress in human subjects after visible light irradiation. Taken together, these findings suggest that other portions of the solar spectrum aside from UV, particularly visible light, may also contribute to signs of premature photoaging in skin.

Curcumin enhances the effects of irinotecan on colorectal cancer cells through the generation of reactive oxygen species and activation of the endoplasmic reticulum stress pathway.

PubMed

Huang, Yan-Feng; Zhu, Da-Jian; Chen, Xiao-Wu; Chen, Qi-Kang; Luo, Zhen-Tao; Liu, Chang-Chun; Wang, Guo-Xin; Zhang, Wei-Jie; Liao, Nv-Zhu

2017-06-20

Although initially effective against metastatic colorectal cancer (CRC), irinotecan-based chemotherapy leads to resistance and adverse toxicity. Curcumin is well known for its anti-cancer effects in many cancers, including CRC. Here, we describe reactive oxygen species (ROS) generation and endoplasmic reticulum (ER) stress as important mechanisms by which curcumin enhances irinotecan's effects on CRC cells. CRC cell lines were treated with curcumin and/or irinotecan for 24 h, and then evaluated using cell proliferation assays, cell apoptosis assays, cell cycle analysis, intracellular Ca2+ measurements, ROS measurements and immunoblotting for key ER stress-related proteins. We found that cell viability was inhibited and apoptosis was increased, accompanied by ROS generation and ER stress activation in CRC cells treated with curcumin alone or in combination with irinotecan. Blocking ROS production attenuated the expression of two markers of ER stress: binding of immunoglobulin protein (BIP) and CCAAT/enhancer-binding protein homologous protein (CHOP). Blocking CHOP expression using RNA interference also inhibited ROS generation. These results demonstrated that curcumin could enhance the effects of irinotecan on CRC cells by inhibiting cell viability and inducing cell cycle arrest and apoptosis, and that these effects may be mediated, in part, by ROS generation and activation of the ER stress pathway.

The chemopreventive action of bromelain, from pineapple stem (Ananas comosus L.), on colon carcinogenesis is related to antiproliferative and proapoptotic effects.

PubMed

Romano, Barbara; Fasolino, Ines; Pagano, Ester; Capasso, Raffaele; Pace, Simona; De Rosa, Giuseppe; Milic, Natasa; Orlando, Pierangelo; Izzo, Angelo A; Borrelli, Francesca

2014-03-01

Colorectal cancer is an important health problem across the world. Here, we investigated the possible antiproliferative/proapoptotic effects of bromelain (from the pineapple stem Ananas comosus L., family Bromeliaceae) in a human colorectal carcinoma cell line and its potential chemopreventive effect in a murine model of colon cancer. Proliferation and apoptosis were evaluated in human colon adenocarcinoma (Caco-2) cells by the (3) H-thymidine incorporation assay and caspase 3/7 activity measurement, respectively. Extracellular signal-related kinase (ERK) and Akt expression were evaluated by Western blot analysis, reactive oxygen species production by a fluorimetric method. In vivo, bromelain was evaluated using the azoxymethane murine model of colon carcinogenesis. Bromelain reduced cell proliferation and promoted apoptosis in Caco-2 cells. The effect of bromelain was associated to downregulation of pERK1/2/total, ERK, and pAkt/Akt expression as well as to reduction of reactive oxygen species production. In vivo, bromelain reduced the development of aberrant crypt foci, polyps, and tumors induced by azoxymethane. Bromelain exerts antiproliferative and proapoptotic effects in colorectal carcinoma cells and chemopreventive actions in colon carcinogenesis in vivo. Bromelain-containing foods and/or bromelain itself may represent good candidates for colorectal cancer chemoprevention. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Functional Analysis of the Trichoderma harzianum nox1 Gene, Encoding an NADPH Oxidase, Relates Production of Reactive Oxygen Species to Specific Biocontrol Activity against Pythium ultimum▿†

PubMed Central

Montero-Barrientos, M.; Hermosa, R.; Cardoza, R. E.; Gutiérrez, S.; Monte, E.

2011-01-01

The synthesis of reactive oxygen species (ROS) is one of the first events following pathogenic interactions in eukaryotic cells, and NADPH oxidases are involved in the formation of such ROS. The nox1 gene of Trichoderma harzianum was cloned, and its role in antagonism against phytopathogens was analyzed in nox1-overexpressed transformants. The increased levels of nox1 expression in these transformants were accompanied by an increase in ROS production during their direct confrontation with Pythium ultimum. The transformants displayed an increased hydrolytic pattern, as determined by comparing protease, cellulase, and chitinase activities with those for the wild type. In confrontation assays against P. ultimum the nox1-overexpressed transformants were more effective than the wild type, but not in assays against Botrytis cinerea or Rhizoctonia solani. A transcriptomic analysis using a Trichoderma high-density oligonucleotide (HDO) microarray also showed that, compared to gene expression for the interaction of wild-type T. harzianum and P. ultimum, genes related to protease, cellulase, and chitinase activities were differentially upregulated in the interaction of a nox1-overexpressed transformant with this pathogen. Our results show that nox1 is involved in T. harzianum ROS production and antagonism against P. ultimum. PMID:21421791

The [NiFe]-hydrogenase of the cyanobacterium Synechocystis sp. PCC 6803 works bidirectionally with a bias to H2 production.

PubMed

McIntosh, Chelsea L; Germer, Frauke; Schulz, Rüdiger; Appel, Jens; Jones, Anne K

2011-07-27

Protein film electrochemistry (PFE) was utilized to characterize the catalytic activity and oxidative inactivation of a bidirectional [NiFe]-hydrogenase (HoxEFUYH) from the cyanobacterium Synechocystis sp. PCC 6803. PFE provides precise control of the redox potential of the adsorbed enzyme so that its activity can be monitored under changing experimental conditions as current. The properties of HoxEFUYH are different from those of both the standard uptake and the "oxygen-tolerant" [NiFe]-hydrogenases. First, HoxEFUYH is biased toward proton reduction as opposed to hydrogen oxidation. Second, despite being expressed under aerobic conditions in vivo, HoxEFUYH is clearly not oxygen-tolerant. Aerobic inactivation of catalytic hydrogen oxidation by HoxEFUYH is total and nearly instantaneous, producing two inactive states. However, unlike the Ni-A and Ni-B inactive states of standard [NiFe]-hydrogenases, both of these states are quickly (<90 s) reactivated by removal of oxygen and exposure to reducing conditions. Third, proton reduction continues at 25-50% of the maximal rate in the presence of 1% oxygen. Whereas most previously characterized [NiFe]-hydrogenases seem to be preferential hydrogen oxidizing catalysts, the cyanobacterial enzyme works effectively in both directions. This unusual catalytic bias as well as the ability to be quickly reactivated may be essential to fulfilling the physiological role in cyanobacteria, organisms expected to experience swings in cellular reduction potential as they switch between aerobic conditions in the light and dark anaerobic conditions. Our results suggest that the uptake [NiFe]-hydrogenases alone are not representative of the catalytic diversity of [NiFe]-hydrogenases, and the bidirectional heteromultimeric enzymes may serve as valuable models to understand the diverse mechanisms of tuning the reactivity of the hydrogen activating site.

Systemic GLIPR1-ΔTM protein as a novel therapeutic approach for prostate cancer.

PubMed

Karantanos, Theodoros; Tanimoto, Ryuta; Edamura, Kohei; Hirayama, Takahiro; Yang, Guang; Golstov, Alexei A; Wang, Jianxiang; Kurosaka, Shinji; Park, Sanghee; Thompson, Timothy C

2014-04-15

GLIPR1 is a p53 target gene known to be downregulated in prostate cancer, and increased endogenous GLIPR1 expression has been associated with increased production of reactive oxygen species, increased apoptosis, decreased c-Myc protein levels and increased cell cycle arrest. Recently, we found that upregulation of GLIPR1 in prostate cancer cells increases mitotic catastrophe through interaction with heat shock cognate protein 70 (Hsc70) and downregulation of Aurora kinase A and TPX2. In this study, we evaluated the mechanisms of recombinant GLIPR1 protein (glioma pathogenesis-related protein 1-transmembrane domain deleted [GLIPR1-ΔTM]) uptake by prostate cancer cells and the efficacy of systemic GLIPR1-ΔTM administration in a prostate cancer xenograft mouse model. GLIPR1-ΔTM was selectively internalized by prostate cancer cells, leading to increased apoptosis through reactive oxygen species production and to decreased c-Myc protein levels. Interestingly, GLIPR1-ΔTM was internalized through clathrin-mediated endocytosis in association with Hsc70. Systemic administration of GLIPR1-ΔTM significantly inhibited VCaP xenograft growth. GLIPR1-ΔTM showed no evidence of toxicity following elimination from mouse models 8 hr after injection. Our results demonstrate that GLIPR1-ΔTM is selectively endocytosed by prostate cancer cells, leading to increased reactive oxygen species production and apoptosis, and that systemic GLIPR1-ΔTM significantly inhibits growth of VCaP xenografts without substantial toxicity. © 2013 UICC.

Vitamin K3 induces antiproliferative effect in cervical epithelial cells transformed by HPV 16 (SiHa cells) through the increase in reactive oxygen species production.

PubMed

de Carvalho Scharf Santana, Natália; Lima, Natália Alves; Desoti, Vânia Cristina; Bidóia, Danielle Lazarin; de Souza Bonfim Mendonça, Patrícia; Ratti, Bianca Altrão; Nakamura, Tânia Ueda; Nakamura, Celso Vataru; Consolaro, Marcia Edilaine Lopes; Ximenes, Valdecir Farias; de Oliveira Silva, Sueli

2016-10-01

Cervical cancer is characterized as an important public health problem. According to latest estimates, cancer of the cervix is the fourth most common cancer among women. Due to its high prevalence, the search for new and efficient drugs to treat this infection is continuous. The progression of HPV-associated cervical cancer involves the expression of two viral proteins, E6 and E7, which are rapidly degraded by the ubiquitin-proteasome system through the increase in reactive oxygen species generation. Vitamins are essential to human substances, participate in the regulation of metabolism, and facilitate the process of energy transfer. Some early studies have indicated that vitamin K3 exerts antitumor activity by inducing cell death by apoptosis through an increase in the generation of reactive oxygen species. Thus, we evaluated the antiproliferative effect and a likely mechanism of action of vitamin K3 against cervical epithelial cells transformed by HPV 16 (SiHa cells) assessing the production of total ROS, the mitochondrial membrane potential, the cell morphology, the cell volume, and the cell membrane integrity. Our results show that vitamin K3 induces an increase in ROS production in SiHa cells, triggering biochemical and morphological events, such as depolarization of mitochondrial membrane potential and decreasing cell volume. Our data showed that vitamin K3 generates an oxidative imbalance in SiHa cells, leading to mechanisms that induce cell death by apoptosis.

Effect of ectomycorrhizal colonization and drought on reactive oxygen species metabolism of Nothofagus dombeyi roots.

PubMed

Alvarez, Maricel; Huygens, Dries; Fernandez, Carlos; Gacitúa, Yessy; Olivares, Erick; Saavedra, Isabel; Alberdi, Miren; Valenzuela, Eduardo

2009-08-01

Infection with ectomycorrhizal fungi can increase the ability of plants to resist drought stress through morphophysiological and biochemical mechanisms. However, the metabolism of antioxidative enzyme activities in the ectomycorrhizal symbiosis remains poorly understood. This study investigated biomass production, reactive oxygen metabolism (hydrogen peroxide and malondialdehyde concentration) and antioxidant enzyme activity (superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase) in pure cultures of the ectomycorrhizal fungi Descolea antartica Sing. and Pisolithus tinctorius (Pers.) Coker & Couch, and non-mycorrhizal and mycorrhizal roots of Nothofagus dombeyi (Mirb.) roots under well-watered conditions and drought conditions (DC). The studied ectomycorrhizal fungi regulated their antioxidative enzyme metabolism differentially in response to drought, resulting in cellular damage in D. antartica but not in P. tinctorius. Ectomycorrhizal inoculation and water treatment had a significant effect on all parameters studied, including relative water content of the plant. As such, N. dombeyi plants in symbiosis experienced a lower oxidative stress effect than non-mycorrhizal plants under DC. Additionally, ectomycorrhizal N. dombeyi roots showed a greater antioxidant enzyme activity relative to non-mycorrhizal roots, an effect which was further expressed under DC. The association between the non-specific P. tinctorius and N. dombeyi had a more effective reactive oxygen species (ROS) metabolism than the specific D. antartica-N. dombeyi symbiosis. We conclude that the combination of effective ROS prevention and ROS detoxification by ectomycorrhizal plants resulted in reduced cellular damage and increased plant growth relative to non-mycorrhizal plants under drought.

Icariin attenuates angiotensin II-induced hypertrophy and apoptosis in H9c2 cardiomyocytes by inhibiting reactive oxygen species-dependent JNK and p38 pathways

PubMed Central

ZHOU, HENG; YUAN, YUAN; LIU, YUAN; DENG, WEI; ZONG, JING; BIAN, ZHOU-YAN; DAI, JIA; TANG, QI-ZHU

2014-01-01

Icariin, the major active component isolated from plants of the Epimedium family, has been reported to have potential protective effects on the cardiovascular system. However, it is not known whether icariin has a direct effect on angiotensin II (Ang II)-induced cardiomyocyte enlargement and apoptosis. In the present study, embryonic rat heart-derived H9c2 cells were stimulated by Ang II, with or without icariin administration. Icariin treatment was found to attenuate the Ang II-induced increase in mRNA expression levels of hypertrophic markers, including atrial natriuretic peptide and B-type natriuretic peptide, in a concentration-dependent manner. The cell surface area of Ang II-treated H9c2 cells also decreased with icariin administration. Furthermore, icariin repressed Ang II-induced cell apoptosis and protein expression levels of Bax and cleaved-caspase 3, while the expression of Bcl-2 was increased by icariin. In addition, 2′,7′-dichlorofluorescein diacetate incubation revealed that icariin inhibited the production of intracellular reactive oxygen species (ROS), which were stimulated by Ang II. Phosphorylation of c-Jun N-terminal kinase (JNK) and p38 in Ang II-treated H9c2 cells was blocked by icariin. Therefore, the results of the present study indicated that icariin protected H9c2 cardiomyocytes from Ang II-induced hypertrophy and apoptosis by inhibiting the ROS-dependent JNK and p38 pathways. PMID:24940396

Reactive oxygen species in the presence of high glucose alter ureteric bud morphogenesis.

PubMed

Zhang, Shao-Ling; Chen, Yun-Wen; Tran, Stella; Chenier, Isabelle; Hébert, Marie-Josée; Ingelfinger, Julie R

2007-07-01

Renal malformations are a major cause of childhood renal failure. During the development of the kidney, ureteric bud (UB) branching morphogenesis is critical for normal nephrogenesis. These studies investigated whether renal UB branching morphogenesis is altered by a high ambient glucose environment and studied underlying mechanism(s). Kidney explants that were isolated from different periods of gestation (embryonic days 12 to 18) from Hoxb7-green fluorescence protein mice were cultured for 24 h in either normal d-glucose (5 mM) or high d-glucose (25 mM) medium with or without various inhibitors. Alterations in renal morphogenesis were assessed by fluorescence microscopy. Paired-homeobox 2 (Pax-2) gene expression was determined by real-time quantitative PCR, Western blotting, and immunohistology. The results revealed that high d-glucose (25 mM) specifically stimulates UB branching morphogenesis via Pax-2 gene expression, whereas other glucose analogs, such as d-mannitol, l-glucose, and 2-deoxy-d-glucose, had no effect. The stimulatory effect of high glucose on UB branching was blocked in the presence of catalase and inhibitors of NADPH oxidase, mitochondrial electron transport chain complex I, and Akt signaling. Moreover, in in vivo studies, it seems that high glucose induces, via Pax-2 (mainly localized in UB), acceleration of UB branching but not nephron formation. Taken together, these data demonstrate that high glucose alters UB branching morphogenesis. This occurs, at least in part, via reactive oxygen species generation, activation of Akt signaling, and upregulation of Pax-2 gene expression.

Salicylic acid signaling inhibits apoplastic reactive oxygen species signaling

PubMed Central

2014-01-01

Background Reactive oxygen species (ROS) are used by plants as signaling molecules during stress and development. Given the amount of possible challenges a plant face from their environment, plants need to activate and prioritize between potentially conflicting defense signaling pathways. Until recently, most studies on signal interactions have focused on phytohormone interaction, such as the antagonistic relationship between salicylic acid (SA)-jasmonic acid and cytokinin-auxin. Results In this study, we report an antagonistic interaction between SA signaling and apoplastic ROS signaling. Treatment with ozone (O3) leads to a ROS burst in the apoplast and induces extensive changes in gene expression and elevation of defense hormones. However, Arabidopsis thaliana dnd1 (defense no death1) exhibited an attenuated response to O3. In addition, the dnd1 mutant displayed constitutive expression of defense genes and spontaneous cell death. To determine the exact process which blocks the apoplastic ROS signaling, double and triple mutants involved in various signaling pathway were generated in dnd1 background. Simultaneous elimination of SA-dependent and SA-independent signaling components from dnd1 restored its responsiveness to O3. Conversely, pre-treatment of plants with SA or using mutants that constitutively activate SA signaling led to an attenuation of changes in gene expression elicited by O3. Conclusions Based upon these findings, we conclude that plants are able to prioritize the response between ROS and SA via an antagonistic action of SA and SA signaling on apoplastic ROS signaling. PMID:24898702

Sibutramine provokes apoptosis of aortic endothelial cells through altered production of reactive oxygen and nitrogen species.

PubMed

Morikawa, Yoshifumi; Shibata, Akinobu; Okumura, Naoko; Ikari, Akira; Sasajima, Yasuhide; Suenami, Koichi; Sato, Kiyohito; Takekoshi, Yuji; El-Kabbani, Ossama; Matsunaga, Toshiyuki

2017-01-01

Overdose administration of sibutramine, a serotonin-noradrenalin reuptake inhibitor, is considered to elicit severe side effects including hypertension, whose pathogenic mechanism remains unclear. Here, we found that 48-h incubation with >10μM sibutramine provokes apoptosis of human aortic endothelial (HAE) cells. Treatment with the lethal concentration of sibutramine facilitated production of reactive oxygen species (ROS), altered expression of endoplasmic reticulum stress response genes (heat shock protein 70 and C/EBP homologous protein), and inactivated 26S proteasome-based proteolysis. The treatment also decreased cellular level of nitric oxide (NO) through lowering of expression and activity of endothelial NO synthase. These results suggest that ROS production and depletion of NO are crucial events in the apoptotic mechanism and may be linked to the pathogenesis of vasoconstriction elicited by the drug. Compared to sibutramine, its metabolites (N-desmethylsibutramine and N-didesmethylsibutramine) were much less cytotoxic to HAE cells, which hardly metabolized sibutramine. In contrast, both the drug and metabolites showed low cytotoxicity to hepatic HepG2 cells with high metabolic potency and expression of cytochrome P450 (CYP) 3A4. The cytotoxicity of sibutramine to HepG2 and Chang Liver cells was remarkably augmented by inhibition and knockdown of CYP3A4. This study also suggests an inverse relationship between sibutramine cytotoxicity and CYP3A4-mediated metabolism into the N-desmethyl metabolites. Copyright © 2016 Elsevier Inc. All rights reserved.

Activation of a Ca2+-dependent cation conductance with properties of TRPM2 by reactive oxygen species in lens epithelial cells.

PubMed

Keckeis, Susanne; Wernecke, Laura; Salchow, Daniel J; Reichhart, Nadine; Strauß, Olaf

2017-08-01

Ion channels are crucial for maintenance of ion homeostasis and transparency of the lens. The lens epithelium is the metabolically and electrophysiologically active cell type providing nutrients, ions and water to the lens fiber cells. Ca 2+ -dependent non-selective ion channels seem to play an important role for ion homeostasis. The aim of the study was to identify and characterize Ca 2+ - and reactive oxygen species (ROS)-dependent non-selective cation channels in human lens epithelial cells. RT-PCR revealed gene expression of the Ca 2+ -activated non-selective cation channels TRPC3, TRPM2, TRPM4 and Ano6 in both primary lens epithelial cells and the cell line HLE-B3, whereas TRPM5 mRNA was only found in HLE-B3 cells. Using whole-cell patch-clamp technique, ionomycin evoked non-selective cation currents with linear current-voltage relationship in both cell types. The current was decreased by flufenamic acid (FFA), 2-APB, 9-phenanthrol and miconazole, but insensitive to DIDS, ruthenium red, and intracellularly applied spermine. H 2 O 2 evoked a comparable current, abolished by FFA. TRPM2 protein expression in HLE-B3 cells was confirmed by means of immunocytochemistry and western blot. In summary, we conclude that lens epithelial cells functionally express Ca 2+ - and H 2 O 2 -activated non-selective cation channels with properties of TRPM2. Copyright © 2017. Published by Elsevier Ltd.

Phenethyl isothiocyanate triggers apoptosis in human malignant melanoma A375.S2 cells through reactive oxygen species and the mitochondria-dependent pathways.

PubMed

Huang, S-H; Hsu, M-H; Hsu, S-C; Yang, J-S; Huang, W-W; Huang, A-C; Hsiao, Y-P; Yu, C-C; Chung, J-G

2014-03-01

We have reported previously that phenethyl isothiocyanate (PEITC) induces apoptosis in human osteosarcoma U-2 OS cells. Cytotoxic activity of PEITC towards other cancer cells such as human malignant melanoma and skin cancer cells has not been reported. In this study, the anticancer activity of PEITC towards human malignant melanoma cancer A375.S2 cells was investigated. To determine the mechanisms of PEITC inhibition of cell growth, the following end points were determined in A375.S2 cells: cell morphological changes, cell cycle arrest, DNA damage and fragmentation assays and morphological assessment of nuclear change, reactive oxygen species (ROS) and Ca(2+) generations, mitochondrial membrane potential disruption, and nitric oxide and 10-N-nonyl acridine orange productions, expression and activation of caspase-3 and -9, B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax), Bcl-2, poly (adenosine diphosphate-ribose) polymerase, and cytochrome c release, apoptosis-inducing factor and endonuclease G. PEITC induced morphological changes in time- and dose-dependent manner. PEITC induced G2/M phase arrest and induced apoptosis via endoplasmic reticulum stress-mediated mitochondria-dependent pathway. Western blot analysis showed that PEITC promoted Bax expression and inhibited Bcl-2 expression associated with the disintegration of the outer mitochondrial membrane causing cytochrome c release, and activation of caspase-9 and -3 cascade leading to apoptosis. We conclude that PEITC-triggered apoptotic death in A375.S2 cells occurs through ROS-mediated mitochondria-dependent pathways.

A novel nematode effector suppresses plant immunity by activating host reactive oxygen species-scavenging system.

PubMed

Lin, Borong; Zhuo, Kan; Chen, Shiyan; Hu, Lili; Sun, Longhua; Wang, Xiaohong; Zhang, Lian-Hui; Liao, Jinling

2016-02-01

Evidence is emerging that plant-parasitic nematodes can secrete effectors to interfere with the host immune response, but it remains unknown how these effectors can conquer host immune responses. Here, we depict a novel effector, MjTTL5, that could suppress plant immune response. Immunolocalization and transcriptional analyses showed that MjTTL5 is expressed specifically within the subventral gland of Meloidogyne javanica and up-regulated in the early parasitic stage of the nematode. Transgenic Arabidopsis lines expressing MjTTL5 were significantly more susceptible to M. javanica infection than wild-type plants, and vice versa, in planta silencing of MjTTL5 substantially increased plant resistance to M. javanica. Yeast two-hybrid, coimmunoprecipitation and bimolecular fluorescent complementation assays showed that MjTTL5 interacts specifically with Arabidopsis ferredoxin : thioredoxin reductase catalytic subunit (AtFTRc), a key component of host antioxidant system. The expression of AtFTRc is induced by the infection of M. javanica. Interaction between AtFTRc and MjTTL could drastically increase host reactive oxygen species-scavenging activity, and result in suppression of plant basal defenses and attenuation of host resistance to the nematode infection. Our results demonstrate that the host ferredoxin : thioredoxin system can be exploited cunningly by M. javanica, revealing a novel mechanism utilized by plant-parasitic nematodes to subjugate plant innate immunity and thereby promoting parasitism. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Absence of Dystrophin Disrupts Skeletal Muscle Signaling: Roles of Ca2+, Reactive Oxygen Species, and Nitric Oxide in the Development of Muscular Dystrophy

PubMed Central

Allen, David G.; Whitehead, Nicholas P.; Froehner, Stanley C.

2015-01-01

Dystrophin is a long rod-shaped protein that connects the subsarcolemmal cytoskeleton to a complex of proteins in the surface membrane (dystrophin protein complex, DPC), with further connections via laminin to other extracellular matrix proteins. Initially considered a structural complex that protected the sarcolemma from mechanical damage, the DPC is now known to serve as a scaffold for numerous signaling proteins. Absence or reduced expression of dystrophin or many of the DPC components cause the muscular dystrophies, a group of inherited diseases in which repeated bouts of muscle damage lead to atrophy and fibrosis, and eventually muscle degeneration. The normal function of dystrophin is poorly defined. In its absence a complex series of changes occur with multiple muscle proteins showing reduced or increased expression or being modified in various ways. In this review, we will consider the various proteins whose expression and function is changed in muscular dystrophies, focusing on Ca2+-permeable channels, nitric oxide synthase, NADPH oxidase, and caveolins. Excessive Ca2+ entry, increased membrane permeability, disordered caveolar function, and increased levels of reactive oxygen species are early changes in the disease, and the hypotheses for these phenomena will be critically considered. The aim of the review is to define the early damage pathways in muscular dystrophy which might be appropriate targets for therapy designed to minimize the muscle degeneration and slow the progression of the disease. PMID:26676145

Salicylic acid signaling inhibits apoplastic reactive oxygen species signaling.

PubMed

Xu, Enjun; Brosché, Mikael

2014-06-04

Reactive oxygen species (ROS) are used by plants as signaling molecules during stress and development. Given the amount of possible challenges a plant face from their environment, plants need to activate and prioritize between potentially conflicting defense signaling pathways. Until recently, most studies on signal interactions have focused on phytohormone interaction, such as the antagonistic relationship between salicylic acid (SA)-jasmonic acid and cytokinin-auxin. In this study, we report an antagonistic interaction between SA signaling and apoplastic ROS signaling. Treatment with ozone (O3) leads to a ROS burst in the apoplast and induces extensive changes in gene expression and elevation of defense hormones. However, Arabidopsis thaliana dnd1 (defense no death1) exhibited an attenuated response to O3. In addition, the dnd1 mutant displayed constitutive expression of defense genes and spontaneous cell death. To determine the exact process which blocks the apoplastic ROS signaling, double and triple mutants involved in various signaling pathway were generated in dnd1 background. Simultaneous elimination of SA-dependent and SA-independent signaling components from dnd1 restored its responsiveness to O3. Conversely, pre-treatment of plants with SA or using mutants that constitutively activate SA signaling led to an attenuation of changes in gene expression elicited by O3. Based upon these findings, we conclude that plants are able to prioritize the response between ROS and SA via an antagonistic action of SA and SA signaling on apoplastic ROS signaling.

The Antitumor Effect of Singlet Oxygen.

PubMed

Bauer, Georg

2016-11-01

Tumor cells are protected against intercellular apoptosis-inducing signaling through expression of membrane-associated catalase and superoxide dismutase. Exogenous singlet oxygen derived from activated photosensitizers or from cold atmospheric plasma causes local inactivation of protective catalase which is followed by the generation of secondary extracellular singlet oxygen. This process is specific for tumor cells and is driven by a complex interaction between H 2 O 2 and peroxynitrite. Secondary singlet oxygen has the potential for autoamplification of its generation, resulting in optimal inactivation of protective catalase and reactivation of intercellular apoptosis-inducing signaling. An increase in the endogenous NO concentration also causes inactivation of catalase and autoamplificatory generation of secondary singlet oxygen. This principle is essential for the antitumor activity of secondary plant products, such as cyanidins and other inhibitors of NO dioxygenase. It seems that the action of the established chemotherapeutic taxol and the recently established antitumor effect of certain azoles are based on the same principles. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Scoparone attenuates RANKL-induced osteoclastic differentiation through controlling reactive oxygen species production and scavenging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Sang-Hyun; Jang, Hae-Dong, E-mail: haedong@hnu.kr

Scoparone, one of the bioactive components of Artemisia capillaris Thunb, has various biological properties including immunosuppressive, hepatoprotective, anti-allergic, anti-inflammatory, and antioxidant effects. This study aims at evaluating the anti-osteoporotic effect of scoparone and its underlying mechanism in vitro. Scoparone demonstrated potent cellular antioxidant capacity. It was also found that scoparone inhibited the receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation and suppressed cathepsin K and tartrate-resistant acid phosphatase (TRAP) expression via c-jun N-terminal kinase (JNK)/extracellular signal-regulated kinase (ERK)/p38-mediated c-Fos–nuclear factor of activated T cells, cytoplasmic 1 (NFATc1) signaling pathway. During osteoclast differentiation, the production of general reactive oxygen speciesmore » (ROS) and superoxide anions was dose-dependently attenuated by scoparone. In addition, scoparone diminished NADPH (nicotinamide adenine dinucleotide phosphate) oxidase 1 (Nox1) expression and activation via the tumor necrosis factor receptor-associated factor 6 (TRAF6)–cSrc–phosphatidylinositol 3-kinase (PI3k) signaling pathway and prevented the disruption of mitochondrial electron transport chain system. Furthermore, scoparone augmented the expression of superoxide dismutase 1 (SOD1) and catalase (CAT). The overall results indicate that the inhibitory effect of scoparone on RANKL-induced osteoclast differentiation is attributed to the suppressive effect on ROS and superoxide anion production by inhibiting Nox1 expression and activation and protecting the mitochondrial electron transport chain system and the scavenging effect of ROS resulting from elevated SOD1 and CAT expression. - Highlights: • Scoparone dose-dependently inhibited RANKL-induced osteoclast differentiation. • Scoparone diminished general ROS and superoxide anions in a dose-dependent manner. • Scoparone inhibited Nox1 expression and activation. • Scoparone prevented the disruption of mitochondrial electron transport chain system. • Scoparone augmented superoxide dismutase and catalase expression.« less

High-dose catecholamine treatment decreases polymorphonuclear leukocyte phagocytic capacity and reactive oxygen production.

PubMed Central

Wenisch, C; Parschalk, B; Weiss, A; Zedwitz-Liebenstein, K; Hahsler, B; Wenisch, H; Georgopoulos, A; Graninger, W

1996-01-01

Flow cytometry was used to study phagocytic function (uptake of fluorescein isothiocyanate-labeled bacteria) and release of reactive oxygen products (dihydrorhodamine 123 converted to rhodamine 123) following phagocytosis by neutrophil granulocytes of heparinized whole blood treated with adrenaline, noradrenaline, dopamine, dobutamine, or orciprenaline. Reduced neutrophil phagocytosis and reactive oxygen production were seen at 12 micrograms of adrenaline per liter (72% each compared with control values); at 120 micrograms of noradrenaline (72% each), dobutamine (83 and 80%, respectively), and orciprenaline (81 and 80%, respectively) per liter; and at 100 micrograms of dopamine per liter (66 and 70%) (P < 0.05 for all). At these dosages, neutrophil chemotaxis was reduced to < 50% of control values for all catecholamines. Treatment with catecholamines at lower dosages had no significant effect on phagocytosis or generation of reactive oxygen products or chemotaxis. The phagocytic capacity of granulocytes was related to the generation of reactive oxygen products (r = 0.789; P < 0.05). The results demonstrate that catecholamines have a suppressive effect on the response of phagocytic cells to bacterial pathogens at high therapeutic levels in blood. PMID:8807207

Functional activity and tumor-specific expression of dual oxidase 2 in pancreatic cancer cells and human malignancies characterized with a novel monoclonal antibody.

PubMed

Wu, Yonghzong; Antony, Smitha; Hewitt, Stephen M; Jiang, Guojian; Yang, Sherry X; Meitzler, Jennifer L; Juhasz, Agnes; Lu, Jiamo; Liu, Han; Doroshow, James H; Roy, Krishnendu

2013-04-01

Dual oxidase 2 (Duox2), one of the seven members of the NADPH oxidase gene family, plays a critical role in generating H2O2 for thyroid hormone biosynthesis and as an integral part of the host defense system of the respiratory epithelium and the gastrointestinal tract. Recent evidence suggests that the regulation of Duox2 expression is under the control of pro-inflammatory cytokines and that Duox2-induced reactive oxygen species (ROS) contribute to the inflammation-related tissue injury that occurs in two pre-malignant, inflammatory conditions: chronic pancreatitis and inflammatory bowel disease. Because no reliable Duox antibodies are commercially available, we report the development of a murine monoclonal antibody (MAb) to Duox2 (clone Duox S-12) and its use for the characterization of Duox2 expression in human tumors, tumor cell lines and normal tissues. Duox S-12 specifically detected both endogenously- and ectopically-expressed Duox2 protein by immunoblotting, immunofluorescence microscopy and immunohistochemistry (where both membranous and cytoplasmic staining were present). Duox2 expression detected by Duox S-12 was functionally coupled to the generation of H(2)O(2) in pancreatic cancer cells that expressed Duox2 and its cognate maturation factor DuoxA2. Although Duox S-12 recognizes ectopically expressed Duox1 protein because of the extensive amino acid homology between Duox1 and Duox2, the lack of substantial Duox1 mRNA expression in human tumors (except thyroid cancer) allowed us to evaluate Duox2 expression across a wide range of normal and malignant tissues by immuno-histochemistry. Duox2 was expressed at elevated levels in many human cancers, most notably tumors of the prostate, lung, colon and breast while brain tumors and lymphomas demonstrated the lowest frequency of expression. The Duox-specific monoclonal antibody described here provides a promising tool for the further examination of the role of Duox-dependent reactive oxygen production in inflammation-related carcinogenesis, where alterations in oxidant tone play a critical role in cell growth and proliferation.

Oxidative Stressors Modify the Response of Streptococcus mutans to Its Competence Signal Peptides.

PubMed

De Furio, Matthew; Ahn, Sang Joon; Burne, Robert A; Hagen, Stephen J

2017-11-15

The dental caries pathogen Streptococcus mutans is continually exposed to several types of stress in the oral biofilm environment. Oxidative stress generated by reactive oxygen species has a major impact on the establishment, persistence, and virulence of S. mutans Here, we combined fluorescent reporter-promoter fusions with single-cell imaging to study the effects of reactive oxygen species on activation of genetic competence in S. mutans Exposure to paraquat, which generates superoxide anion, produced a qualitatively different effect on activation of expression of the gene for the master competence regulator, ComX, than did treatment with hydrogen peroxide (H 2 O 2 ), which can yield hydroxyl radical. Paraquat suppressed peptide-mediated induction of comX in a progressive and cumulative fashion, whereas the response to H 2 O 2 displayed a strong threshold behavior. Low concentrations of H 2 O 2 had little effect on induction of comX or the bacteriocin gene cipB , but expression of these genes declined sharply if extracellular H 2 O 2 exceeded a threshold concentration. These effects were not due to decreased reporter gene fluorescence. Two different threshold concentrations were observed in the response to H 2 O 2 , depending on the gene promoter that was analyzed and the pathway by which the competence regulon was stimulated. The results show that paraquat and H 2 O 2 affect the S. mutans competence signaling pathway differently, and that some portions of the competence signaling pathway are more sensitive to oxidative stress than others. IMPORTANCE Streptococcus mutans inhabits the oral biofilm, where it plays an important role in the development of dental caries. Environmental stresses such as oxidative stress influence the growth of S. mutans and its important virulence-associated behaviors, such as genetic competence. S. mutans competence development is a complex behavior that involves two different signaling peptides and can exhibit cell-to-cell heterogeneity. Although oxidative stress is known to influence S. mutans competence, it is not understood how oxidative stress interacts with the peptide signaling or affects heterogeneity. In this study, we used fluorescent reporters to probe the effect of reactive oxygen species on competence signaling at the single-cell level. Our data show that different reactive oxygen species have different effects on S. mutans competence, and that some portions of the signaling pathway are more acutely sensitive to oxidative stress than others. Copyright © 2017 American Society for Microbiology.

GST ( phi) gene from Macrophyte Lemna minor is involved in cadmium exposure responses

NASA Astrophysics Data System (ADS)

Chen, Shihua; Chen, Xin; Dou, Weihong; Wang, Liang; Yin, Haibo; Guo, Shanli

2016-03-01

Reactive oxygen species (ROS) scavengers, including ascorbate peroxidase, superoxide dismutase, catalase and peroxidase, are the most commonly used biomarkers in assessing an organisms' response to many biotic and abiotic stresses. In this study, we cloned an 866 bp GST ( phi) gene in Lemna minor and investigated its characteristics, expression and enzymatic activities under 75 μmol/L cadmium concentrations in comparison with other ROS scavengers. GST ( phi) gene expression patterns were similar to those of other scavengers of ROS. This suggests that GST ( phi) might be involved in responding to heavy metal (cadmium) stress and that its expression level could be used as a bio-indicator in monitoring cadmium pollution.

The metallothionein gene from the white shrimp Litopenaeus vannamei: characterization and expression in response to hypoxia.

PubMed

Felix-Portillo, Monserrath; Martinez-Quintana, José A; Peregrino-Uriarte, Alma B; Yepiz-Plascencia, Gloria

2014-10-01

Aquatic animals encounter variation in oxygen tension that leads to the accumulation of reactive oxygen species (ROS) that can harm the organisms. Under these circumstances some organisms have evolved to tolerate hypoxia. In mammals, metallothioneins (MTs) protect against hypoxia-generated ROS. Here we report the MT gene from the shrimp Litopenaeus vannamei (LvMT). LvMT is differentially expressed in hemocytes, intestine, gills, pleopods, heart, hepatopancreas and muscle, with the highest levels in hepatopancreas and heart. LvMT mRNA increases during hypoxia in hepatopancreas and gills after 3 h at 1.5 mg L(-1) dissolved oxygen (DO). This gene structure resembles the homologs from invertebrates and vertebrates possessing three exons, two introns and response elements for metal response transcription factor 1 (MTF-1), hypoxia-inducible factor 1 (HIF-1) and p53 in the promoter region. During hypoxia, HIF-1/MTF-1 might participate inducing MT to contribute towards the tolerance to ROS toxicity. MT importance in aquatic organisms may include also ROS-detoxifying processes. Copyright © 2014 Elsevier Ltd. All rights reserved.

Oxygen Activation and Radical Transformations in Heme Proteins and Metalloporphyrins

PubMed Central

2017-01-01

As a result of the adaptation of life to an aerobic environment, nature has evolved a panoply of metalloproteins for oxidative metabolism and protection against reactive oxygen species. Despite the diverse structures and functions of these proteins, they share common mechanistic grounds. An open-shell transition metal like iron or copper is employed to interact with O2 and its derived intermediates such as hydrogen peroxide to afford a variety of metal–oxygen intermediates. These reactive intermediates, including metal-superoxo, -(hydro)peroxo, and high-valent metal–oxo species, are the basis for the various biological functions of O2-utilizing metalloproteins. Collectively, these processes are called oxygen activation. Much of our understanding of the reactivity of these reactive intermediates has come from the study of heme-containing proteins and related metalloporphyrin compounds. These studies not only have deepened our understanding of various functions of heme proteins, such as O2 storage and transport, degradation of reactive oxygen species, redox signaling, and biological oxygenation, etc., but also have driven the development of bioinorganic chemistry and biomimetic catalysis. In this review, we survey the range of O2 activation processes mediated by heme proteins and model compounds with a focus on recent progress in the characterization and reactivity of important iron–oxygen intermediates. Representative reactions initiated by these reactive intermediates as well as some context from prior decades will also be presented. We will discuss the fundamental mechanistic features of these transformations and delineate the underlying structural and electronic factors that contribute to the spectrum of reactivities that has been observed in nature as well as those that have been invented using these paradigms. Given the recent developments in biocatalysis for non-natural chemistries and the renaissance of radical chemistry in organic synthesis, we envision that new enzymatic and synthetic transformations will emerge based on the radical processes mediated by metalloproteins and their synthetic analogs. PMID:29286645

Integration of oxygen signaling at the consensus HRE.

PubMed

Wenger, Roland H; Stiehl, Daniel P; Camenisch, Gieri

2005-10-18

The hypoxia-inducible factor 1 (HIF-1) was initially identified as a transcription factor that regulated erythropoietin gene expression in response to a decrease in oxygen availability in kidney tissue. Subsequently, a family of oxygen-dependent protein hydroxylases was found to regulate the abundance and activity of three oxygen-sensitive HIFalpha subunits, which, as part of the HIF heterodimer, regulated the transcription of at least 70 different effector genes. In addition to responding to a decrease in tissue oxygenation, HIF is proactively induced, even under normoxic conditions, in response to stimuli that lead to cell growth, ultimately leading to higher oxygen consumption. The growing cell thus profits from an anticipatory increase in HIF-dependent target gene expression. Growth stimuli-activated signaling pathways that influence the abundance and activity of HIFs include pathways in which kinases are activated and pathways in which reactive oxygen species are liberated. These pathways signal to the HIF protein hydroxylases, as well as to HIF itself, by means of covalent or redox modifications and protein-protein interactions. The final point of integration of all of these pathways is the hypoxia-response element (HRE) of effector genes. Here, we provide comprehensive compilations of the known growth stimuli that promote increases in HIF abundance, of protein-protein interactions involving HIF, and of the known HIF effector genes. The consensus HRE derived from a comparison of the HREs of these HIF effectors will be useful for identification of novel HIF target genes, design of oxygen-regulated gene therapy, and prediction of effects of future drugs targeting the HIF system.

Comparison of two strategies for detection of reactive oxygen species

NASA Astrophysics Data System (ADS)

Gao, Weidong; Zhou, Yuanshu; Gu, Yueqing

2014-09-01

Photodynamic therapy (PDT) is a clinically approved treatment that was applied to oncology , dermatology, and ophthalmology. Reactive oxygen species (ROS) play a important role in the efficacy of PDT. Online monitoring of reactive oxygen species is the key to understand effect of PDT treatment. We used Fluorescence probes DPBF and luminescent probe luminal to measure the ROS in cells. And we revaluate the relationship between the amount of light and cell survival. There is strongly correlated between the amount of light and cell kill.

Neuroprotective effects of angiotensin II type 1 receptor (AT1-R) blocker via modulating AT1-R signaling and decreased extracellular glutamate levels.

PubMed

Fujita, Tomoyoshi; Hirooka, Kazuyuki; Nakamura, Takehiro; Itano, Toshifumi; Nishiyama, Akira; Nagai, Yukiko; Shiraga, Fumio

2012-06-26

To investigate the mechanism of the neuroprotective effects of the angiotensin II type 1 receptor (AT1-R) blocker against retinal ischemia-reperfusion injury in the rat. Retinal ischemia was induced by increasing intraocular pressure. Glutamate release from the rat retina and intravitreal PO(2) (partial pressure of oxygen) profiles were monitored during and after ischemia using a microdialysis biosensor and oxygen-sensitive microelectrodes. ELISA was used to measure changes in the expression of AT1-R. Retinal mRNA expressions of p47phox and p67phox were measured by real-time polymerase chain reaction. Reactive oxygen species (ROS) were measured using dihydroethidium. Administration of candesartan, which is an AT1-R blocker (ARB), suppressed ischemia-induced increases in the extracellular glutamate. Candesartan also attenuated the increase in intravitreal PO(2) during reperfusion. AT1-R expression peaked at 12 hours after reperfusion. Although there was an increase in the retinal mRNA expression of p47phox and p64phox at 12 hours after the reperfusion, administration of candesartan suppressed these expressions. The production of ROS that was detected at 12 hours after reperfusion was also suppressed by the administration of candesartan or apocynin. NADPH oxidase-mediated ROS production increased at 12 hours after reperfusion. Candesartan may protect neurons by decreasing extracellular glutamate immediately after reperfusion and by attenuating oxidative stress via a modulation of the AT1-R signaling that occurs during ischemic insult.

Reactive oxygen metabolites (ROMs) as an index of oxidative stress in obstructive sleep apnea patients.

PubMed

Christou, Kostas; Markoulis, Nikolaos; Moulas, Anargyros N; Pastaka, Chaido; Gourgoulianis, Kostantinos I

2003-09-01

Obstructive sleep apnea syndrome (OSA) is accompanied by oxygen desaturation and arousal from sleep. Free oxygen radicals are highly reactive molecules which could be produced by the OSA phenomenon of hypoxia/reoxygenation: cyclical alterations of arterial oxygen saturation with oxygen desaturation developing in response to apneas followed by resumption of oxygen saturation during hyperventilation. On the basis of these considerations, it was hypothesized that OSA may be linked to increased oxidative stress. Twenty-six participants gave an interview during which a physician asked them about their age, smoking habits, and symptoms such as excessive daytime sleepiness and snoring. Physical examination and polysomnography were performed during their hospitalization. Reactive oxygen metabolites (ROMs) were measured in blood samples by the diacron reactive oxygen metabolites (D-ROM) test. Twenty-one out of 26 subjects had an apnea/hypopnea index greater than 5 (OSA group). The measurement of free radicals was high in OSA patients. Furthermore, ROMs values in OSA patients were linearly correlated with the apnea/hypopnea index (R = 0.426; p = 0.042). The predictive value of a positive D-ROM test is 81%. ROMs were elevated in patients with OSA. When OSA was severe, similarly the value of ROMs in blood samples was enhanced, and the probable underlying mechanism for these events is the hypoxia/reoxygenation phenomenon.

Osimertinib induces autophagy and apoptosis via reactive oxygen species generation in non-small cell lung cancer cells.

PubMed

Tang, Zheng-Hai; Cao, Wen-Xiang; Su, Min-Xia; Chen, Xiuping; Lu, Jin-Jian

2017-04-15

Osimertinib (OSI), also known as AZD9291, is a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor that has been approved for the treatment of non-small cell lung cancer (NSCLC) patients harboring EGFR T790M mutation. Herein, we indicated for the first time that OSI increased the accumulations of cytoplasmic vacuoles, the expression of phosphatidylethanolamine-modified microtubule-associated protein light-chain 3 (LC3-II), and the formation of GFP-LC3 puncta in various cancer cells. The OSI-induced expression of LC3-II was further increased when combined treatment with chloroquine (CQ), an autophagy inhibitor, and the mRFP-EGFP-LC3 plasmid-transfected cells exposed to OSI led to the production of more red-fluorescent puncta than green-fluorescent puncta, indicating OSI induced autophagic flux in the NSCLC cells. Knockdown of EGFR showed no effect on the OSI-induced expression of LC3-II in NCI-H1975 cells. In addition, OSI increased reactive oxygen species (ROS) generation and scavenge of ROS via pretreatment with N-acetyl-l-cysteine (NAC), catalase (CAT), or vitamin E (Vita E) significantly inhibited OSI-induced the accumulations of cytoplasmic vacuoles, the expression of LC3-II, as well as the formation of GFP-LC3 puncta. Combinative treatment with CQ could not remarkably change the OSI-induced cell viability decrease, whereas the OSI-induced cell viability decrease and apoptosis could be reversed through pretreatment with NAC, CAT, and Vita E, respectively. Taken together, this is the first report that OSI induces an accompanied autophagy and the generation of ROS is critical for the OSI-induced autophagy, cell viability decrease, and apoptosis in NSCLC cells. Copyright © 2017 Elsevier Inc. All rights reserved.

TGF-beta-induced early gene-1 overexpression promotes oxidative stress protection and actin cytoskeleton rearrangement in human skin fibroblasts.

PubMed

Leduc, Chloe; Sobilo, Lauren; Toumi, Hechmi; Mondon, Philippe; Lespessailles, Eric; Ossant, Fédéric; Kurfurst, Robin; Pichon, Chantal

2016-06-01

Transforming growth factor beta inducible early gene-1 (TIEG-1), a member of the Krüppel-like factor, was identified as a primary response gene for TGF-β. The role of TIEG-1 in skin repair has been mainly addressed in vivo on TIEG-1 null mice model and the mechanism remains unexplored. We investigated the modulation of TIEG-1 expression in normal human skin fibroblasts by either down-expressing or overexpressing the gene. We evaluated reactive oxygen species production and the cell viability of treated cells. The effect of TIEG-1 overexpression was monitored by wound healing assay and immunofluorescence staining of actin fibers organization and alpha-smooth muscle actin (α-SMA). Western blots were carried out to identify the level of expression or phosphorylation of key proteins such as cofilin, Rho GTPases, and p38 mitogen-activated protein kinase (p38 MAPK). TIEG-1 down-regulation had a deleterious effect on the cell viability. It was significantly reduced (65±5%) and exposure to ultraviolet further increased this effect (47±3%). By contrast, cells overexpressing TIEG-1 had a reduced reactive oxygen species production (75%) compared to control and mock-transfected cells. This overexpression also resulted in formation of actin stress fibers and increased α-SMA expression and an enhanced wound healing feature. RhoB GTPase was upregulated and phosphorylation of cofilin and p38 MAPK was observed. TIEG-1 overexpression in normal human skin fibroblasts results in improved resistance to oxidative stress, myofibroblast-like conversion that involved RhoB signaling pathway with cofilin and p38 MAPK proteins activation. This study enlightens the role of TIEG-1 role in skin biology. Copyright © 2016 Elsevier B.V. All rights reserved.

Cancer stem-like cells of ovarian clear cell carcinoma are enriched in the ALDH-high population associated with an accelerated scavenging system in reactive oxygen species.

PubMed

Mizuno, T; Suzuki, N; Makino, H; Furui, T; Morii, E; Aoki, H; Kunisada, T; Yano, M; Kuji, S; Hirashima, Y; Arakawa, A; Nishio, S; Ushijima, K; Ito, K; Itani, Y; Morishige, K

2015-05-01

In ovarian cancer cases, recurrence after chemotherapy is frequently observed, suggesting the involvement of ovarian cancer stem-like cells (CSCs). The chemoresistance of ovarian clear cell carcinomas is particularly strong in comparison to other epithelial ovarian cancer subtypes. We investigated the relationship between a CSC marker, aldehyde dehydrogenase 1 (ALDH1), and clinical prognosis using ovarian clear cell carcinoma tissue samples. Furthermore, we investigated the antioxidant mechanism by which CSCs maintain a lower reactive oxygen species (ROS) level, which provides protection from chemotherapeutic agents. Immunohistochemical staining was performed to examine the CSC markers (CD133, CD44, ALDH1) using ovarian clear cell carcinoma tissue samples (n=81). Clear cell carcinoma cell lines (KOC-7C, OVTOKO) are separated into the ALDH-high and ALDH-low populations by ALDEFLUOR assay and fluorescence-activated cell sorting (FACS). We compared the intracellular ROS level, mRNA level of the antioxidant enzymes and Nrf2 expression of the two populations. High ALDH1 expression levels are related to advanced stage in clear cell carcinoma cases. ALDH1 expression significantly reduced progression free survival. Other markers are not related to clinical stage and prognosis. ALDH-high cells contained a lower ROS level than ALDH-low cells. Antioxidant enzymes were upregulated in ALDH-high cells. ALDH-high cells showed increased expression of Nrf2, a key transcriptional factor of the antioxidant system. ALDH-positive CSCs might have increased Nrf2-induced antioxidant scavengers, which lower ROS level relevant to chemoresistance in ovarian clear cell carcinoma. Copyright © 2014 Elsevier Inc. All rights reserved.

Induction of reactive oxygen species-stimulated distinctive autophagy by chelerythrine in non-small cell lung cancer cells.

PubMed

Tang, Zheng-Hai; Cao, Wen-Xiang; Wang, Zhao-Yu; Lu, Jia-Hong; Liu, Bo; Chen, Xiuping; Lu, Jin-Jian

2017-08-01

Chelerythrine (CHE), a natural benzo[c]phenanthridine alkaloid, shows anti-cancer effect through a number of mechanisms. Herein, the effect and mechanism of the CHE-induced autophagy, a type II programmed cell death, in non-small cell lung cancer (NSCLC) cells were studied for the first time. CHE induced cell viability decrease, colony formation inhibition, and apoptosis in a concentration-dependent manner in NSCLC A549 and NCI-H1299 cells. In addition, CHE triggered the expression of phosphatidylethanolamine-modified microtubule-associated protein light-chain 3 (LC3-II). The CHE-induced expression of LC3-II was further increased in the combination treatment with chloroquine (CQ), an autophagy inhibitor, and large amounts of red-puncta were observed in the CHE-treated A549 cells with stable expression of mRFP-EGFP-LC3, indicating that CHE induces autophagy flux. Silence of beclin 1 reversed the CHE-induced expression of LC3-II. Inhibition of autophagy remarkably reversed the CHE-induced cell viability decrease and apoptosis in NCI-H1299 cells but not in A549 cells. Furthermore, CHE triggered reactive oxygen species (ROS) generation in both cell lines. A decreased level of ROS through pretreatment with N-acetyl-L-cysteine reversed the CHE-induced cell viability decrease, apoptosis, and autophagy. Taken together, CHE induced distinctive autophagy in A549 (accompanied autophagy) and NCI-H1299 (pro-death autophagy) cells and a decreased level of ROS reversed the effect of CHE in NSCLC cells in terms of cell viability, apoptosis, and autophagy. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Defective Hematopoietic Stem Cell and Lymphoid Progenitor Development in the Ts65Dn Mouse Model of Down Syndrome: Potential Role of Oxidative Stress

PubMed Central

Lorenzo, Laureanne Pilar E.; Chen, Haiyan; Shatynski, Kristen E.; Clark, Sarah; Yuan, Rong; Harrison, David E.; Yarowsky, Paul J.

2011-01-01

Abstract Aims Down Syndrome (DS), a genetic disease caused by a triplication of chromosome 21, is characterized by increased markers of oxidative stress. In addition to cognitive defects, patients with DS also display hematologic disorders and increased incidence of infections and leukemia. Using the Ts65Dn mouse model of DS, the goal of this study was to examine hematopoietic stem and lymphoid progenitor cell function in DS. Results Analysis of hematopoietic progenitor populations showed that Ts65Dn mice possessed fewer functional hematopoietic stem cells and a significantly decreased percentage of bone marrow lymphoid progenitors. Increased reactive oxygen species and markers of oxidative stress were detected in hematopoietic stem cell populations and were associated with a loss of quiescence. Bone marrow progenitor populations expressed diminished levels of the IL-7Rα chain, which was associated with decreased proliferation and increased apoptosis. Modulating oxidative stress in vitro suggested that oxidative stress selectively leads to decreased IL-7Rα expression, and inhibits the survival of IL-7Rα-expressing hematopoietic progenitors, potentially linking increased reactive oxygen species and immunopathology. Innovation The study results identify a link between oxidative stress and diminished IL-7Rα expression and function. Further, the data suggest that this decrease in IL-7Rα is associated with defective hematopoietic development in Down Syndrome. Conclusion The data suggest that hematopoietic stem and lymphoid progenitor cell defects underlie immune dysfunction in DS and that increased oxidative stress and reduced cytokine signaling may alter hematologic development in Ts65Dn mice. Antioxid. Redox Signal. 15, 2083–2094. PMID:21504363

NADPH oxidase 4 is involved in the triethylene glycol dimethacrylate-induced reactive oxygen species and apoptosis in human embryonic palatal mesenchymal and dental pulp cells.

PubMed

Yeh, Cheng-Chang; Chang, Jenny Zwei-Chieng; Yang, Wan-Hsien; Chang, Hao-Hueng; Lai, Eddie Hsiang-Hua; Kuo, Mark Yen-Ping

2015-07-01

Triethylene glycol dimethacrylate (TEGDMA) is a common component of resin-based dental composites and endodontic sealers. TEGDMA induces apoptosis in several types of cells. However, the mechanisms are not completely understood. The aim of this study was to investigate the mechanisms underlying TEGDMA-induced apoptosis in human embryonic palatal mesenchymal (HEPM) pre-osteoblasts and primary human dental pulp (HDP) cells. Cell viability was examined after TEGDMA treatment. Cell cycle progression was checked by flow cytometry. Apoptotic cells were evaluated using terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling assay and visualized by fluorescence microscopy. Western blot analyses were performed to determine expressions of apoptosis-related proteins. The production of reactive oxygen species (ROS) was detected using flow cytometry. NADPH oxidase 4 (NOX4) expression levels were investigated using real-time quantitative polymerase chain reaction and Western blot analyses. TEGDMA increased cytosol cytochrome c levels and activated caspase-9 in HEPM and HDP cells. TEGDMA decreased the expression of anti-apoptotic protein Bcl-XL. TEGDMA-induced apoptosis was inhibited by caspase-9-specific inhibitor, anti-oxidants, NOX inhibitor, NOX4 inhibitor, and NOX4 small interfering RNA (siRNA). TEGDMA increased ROS production and upregulated NOX4 mRNA and protein expression. TEGDMA-induced intracellular ROS production was inhibited by NOX inhibitor and NOX4 inhibitor. We demonstrate significant involvement of NOX4 in the TEGDMA-induced ROS. NOX4-derived ROS subsequently induces mitochondrial cytochrome c release leading to apoptosis through activation of the intrinsic apoptotic pathway. NOX4 may be a potential target for strategies to prevent or ameliorate the TEGDMA-induced toxicity in HEPM and HDP cells.

Genomic evidence of reactive oxygen species elevation in papillary thyroid carcinoma with Hashimoto thyroiditis.

PubMed

Yi, Jin Wook; Park, Ji Yeon; Sung, Ji-Youn; Kwak, Sang Hyuk; Yu, Jihan; Chang, Ji Hyun; Kim, Jo-Heon; Ha, Sang Yun; Paik, Eun Kyung; Lee, Woo Seung; Kim, Su-Jin; Lee, Kyu Eun; Kim, Ju Han

2015-01-01

Elevated levels of reactive oxygen species (ROS) have been proposed as a risk factor for the development of papillary thyroid carcinoma (PTC) in patients with Hashimoto thyroiditis (HT). However, it has yet to be proven that the total levels of ROS are sufficiently increased to contribute to carcinogenesis. We hypothesized that if the ROS levels were increased in HT, ROS-related genes would also be differently expressed in PTC with HT. To find differentially expressed genes (DEGs) we analyzed data from the Cancer Genomic Atlas, gene expression data from RNA sequencing: 33 from normal thyroid tissue, 232 from PTC without HT, and 60 from PTC with HT. We prepared 402 ROS-related genes from three gene sets by genomic database searching. We also analyzed a public microarray data to validate our results. Thirty-three ROS related genes were up-regulated in PTC with HT, whereas there were only nine genes in PTC without HT (Chi-square p-value < 0.001). Mean log2 fold changes of up-regulated genes was 0.562 in HT group and 0.252 in PTC without HT group (t-test p-value = 0.001). In microarray data analysis, 12 of 32 ROS-related genes showed the same differential expression pattern with statistical significance. In gene ontology analysis, up-regulated ROS-related genes were related with ROS metabolism and apoptosis. Immune function-related and carcinogenesis-related gene sets were enriched only in HT group in Gene Set Enrichment Analysis. Our results suggested that ROS levels may be increased in PTC with HT. Increased levels of ROS may contribute to PTC development in patients with HT.

Inhibition of biphasic ethylene production enhances tolerance to abiotic stress by reducing the accumulation of reactive oxygen species in Nicotiana tabacum.

PubMed

Wi, Soo Jin; Jang, Su Jin; Park, Ky Young

2010-07-01

Reactive oxygen species (ROS), such as H(2)O(2), are important plant cell signaling molecules involved in responses to biotic and abiotic stresses and in developmental and physiological processes. Despite the well-known physiological functions of ethylene production and stress signaling via ROS during stresses, whether ethylene acts alone or in conjunction with ROS has not yet been fully elucidated. Therefore, we investigated the relationship between ethylene production and ROS accumulation during the response to abiotic stress. We used three independent transgenic tobacco lines, CAS-AS-2, -3 and -4, in which an antisense transcript of the senescence-related ACC synthase (ACS) gene from carnation flower (CARACC, Gen-Bank accession No. M66619) was expressed heterologously. Biphasic ethylene biosynthesis was reduced significantly in these transgenic plants, with or without H(2)O(2) treatment. These plants exhibited significantly reduced H(2)O(2)-induced gene-specific expression of ACS members, which were regulated in a time-dependent manner. The higher levels of NtACS1 expression in wild-type plants led to a second peak in ethylene production, which resulted in a more severe level of necrosis and cell death, as determined by trypan blue staining. In the transgenic lines, upregulated transcription of CAB, POR1 and RbcS resulted in increased photosynthetic performance following salt stress. This stress tolerance of H(2)O(2)-treated transgenic plants resulted from reduced ethylene biosynthesis, which decreased ROS accumulation via increased gene expression and activity of ROS-detoxifying enzymes, including MnSOD, CuZnSOD, and catalase. Therefore, it is suggested that ethylene plays a potentially critical role as an amplifier for ROS accumulation, implying a synergistic effect between biosynthesis of ROS and ethylene.

JS-K, a GST-activated nitric oxide donor prodrug, enhances chemo-sensitivity in renal carcinoma cells and prevents cardiac myocytes toxicity induced by Doxorubicin.

PubMed

Qiu, Mingning; Ke, Longzhi; Zhang, Sai; Zeng, Xin; Fang, Zesong; Liu, Jianjun

2017-08-01

Doxorubicin, a highly effective and widely used anthracycline antibiotic in multiple chemotherapy regimens, has been limited by its cardiotoxicity. The aim of this study is to investigate the effect of nitric oxide donor prodrug JS-K on proliferation and apoptosis in renal carcinoma cells and cardiac myocytes toxicity induced by Doxorubicin and to explore possible p53-related mechanism in renal carcinoma cells. The effect of JS-K on anti-cancer activity of Doxorubicin was investigated in renal carcinoma cells via detecting cell proliferation, cytotoxicity, cell death and apoptosis and expressions of apoptotic-related proteins. Effect of p53 on the combination of JS-K and Doxorubicin was determined using p53 inhibitor Pifithrin-α and p53 activator III. Furthermore, the effect of JS-K on cardiac myocytes toxicity of Doxorubicin was investigated in H9c2 (2-1) cardiac myocytes via measuring cell growth, cell death and apoptosis, expressions of proteins involved in apoptosis and intracellular reactive oxygen species. We demonstrated that JS-K could increase Doxorubicin-induced renal carcinoma cell growth suppression and apoptosis and could increase expressions of proteins that are involved in apoptosis. Additionally, Pifithrin-α reversed the promoting effect of JS-K on Doxorubicin-induced renal carcinoma cell apoptosis; conversely, the p53 activator III exacerbated the promoting effect of JS-K on Doxorubicin-induced renal carcinoma cell apoptosis. Furthermore, JS-K protected H9c2 (2-1) cardiac myocytes against Doxorubicin-induced toxicity and decreased Doxorubicin-induced reactive oxygen species production. JS-K enhances the anti-cancer activity of Doxorubicin in renal carcinoma cells by upregulating p53 expression and prevents cardiac myocytes toxicity of Doxorubicin by decreasing oxidative stress.

CYCLIN H;1 regulates drought stress responses and blue light-induced stomatal opening by inhibiting reactive oxygen species accumulation in Arabidopsis.

PubMed

Zhou, Xiao Feng; Jin, Yin Hua; Yoo, Chan Yul; Lin, Xiao-Li; Kim, Woe-Yeon; Yun, Dae-Jin; Bressan, Ray A; Hasegawa, Paul M; Jin, Jing Bo

2013-06-01

Arabidopsis (Arabidopsis thaliana) CYCLIN-DEPENDENT KINASE Ds (CDKDs) phosphorylate the C-terminal domain of the largest subunit of RNA polymerase II. Arabidopsis CYCLIN H;1 (CYCH;1) interacts with and activates CDKDs; however, the physiological function of CYCH;1 has not been determined. Here, we report that CYCH;1, which is localized to the nucleus, positively regulates blue light-induced stomatal opening. Reduced-function cych;1 RNA interference (cych;1 RNAi) plants exhibited a drought tolerance phenotype. CYCH;1 is predominantly expressed in guard cells, and its expression was substantially down-regulated by dehydration. Transpiration of intact leaves was reduced in cych;1 RNAi plants compared with the wild-type control in light but not in darkness. CYCH;1 down-regulation impaired blue light-induced stomatal opening but did not affect guard cell development or abscisic acid-mediated stomatal closure. Microarray and real-time polymerase chain reaction analyses indicated that CYCH;1 did not regulate the expression of abscisic acid-responsive genes or light-induced stomatal opening signaling determinants, such as MYB60, MYB61, Hypersensitive to red and blue1, and Protein phosphatase7. CYCH;1 down-regulation induced the expression of redox homeostasis genes, such as LIPOXYGENASE3 (LOX3), LOX4, ARABIDOPSIS GLUTATHIONE PEROXIDASE 7 (ATGPX7), EARLY LIGHT-INDUCIBLE PROTEIN1 (ELIP1), and ELIP2, and increased hydrogen peroxide production in guard cells. Furthermore, loss-of-function mutations in CDKD;2 or CDKD;3 did not affect responsiveness to drought stress, suggesting that CYCH;1 regulates the drought stress response in a CDKD-independent manner. We propose that CYCH;1 regulates blue light-mediated stomatal opening by controlling reactive oxygen species homeostasis.

Copper-Exchanged Zeolite L Traps Oxygen

NASA Technical Reports Server (NTRS)

Sharma, Pramod K.; Seshan, Panchalam K.

1991-01-01

Brief series of simple chemical treatments found to enhance ability of zeolite to remove oxygen from mixture of gases. Thermally stable up to 700 degrees C and has high specific surface area which provides high capacity for adsorption of gases. To increase ability to adsorb oxygen selectively, copper added by ion exchange, and copper-exchanged zeolite reduced with hydrogen. As result, copper dispersed atomically on inner surfaces of zeolite, making it highly reactive to oxygen, even at room temperature. Reactivity to oxygen even greater at higher temperatures.

Hyperactivity and reactivity of peripheral blood neutrophils in chronic periodontitis.

PubMed

Matthews, J B; Wright, H J; Roberts, A; Cooper, P R; Chapple, I L C

2007-02-01

Some evidence exists that peripheral neutrophils from patients with chronic periodontitis generate higher levels of reactive oxygen species (ROS) after Fcgamma-receptor stimulation than those from healthy controls. We hypothesized that peripheral neutrophils in periodontitis also show both hyper-reactivity to plaque organisms and hyperactivity in terms of baseline, unstimulated generation and release of ROS. Peripheral neutrophils from chronic periodontitis patients and age/sex/smoking-matched healthy controls (18 pairs) were assayed for total ROS generation and extracellular ROS release, with and without stimulation (Fcgamma-receptor and Fusobacterium nucleatum), using luminol and isoluminol chemiluminescence. Assays were performed with and without priming with Escherichia coli lipopolysaccharide (LPS) and granulocyte-macrophage colony-stimulating factor (GM-CSF). Phox gene expression (p22, p47, p67, gp91) was investigated using reverse transcription-polymerase chain reaction (RT-PCR). Neutrophils from patients produced higher mean levels of ROS in all assays. Total generation and extracellular release of ROS by patients' cells were significantly greater than those from controls after FcgammaR-stimulation, with (P = 0.023) and without (P < or = 0.023) priming with GM-CSF. Differences in unstimulated total ROS generation were not significant. By contrast, patients' cells demonstrated greater baseline, extracellular ROS release than those from controls (P = 0.004). This difference was maintained after priming with LPS (P = 0.028) but not GM-CSF (P = 0.217). Phox gene expression was similar in patient and control cells at baseline and stimulation with F. nucleatum (3 h) consistently reduced gp91(PHOX) transcripts. Our data demonstrate that peripheral neutrophils from periodontitis patients exhibit hyper-reactivity following stimulation (Fcgamma-receptor and F. nucleatum) and hyperactivity in terms of excess ROS release in the absence of exogenous stimulation. This hyperactive/-reactive neutrophil phenotype is not associated with elevated phox gene expression.

Hyperbaric oxygenation affects the mechanisms of acetylcholine-induced relaxation in diabetic rats.

PubMed

Unfirer, Sanela; Mihalj, Martina; Novak, Sanja; Kibel, Aleksandar; Cavka, Ava; Mijalevic, Zrinka; Gros, Mario; Brizic, Ivica; Budimir, Danijela; Cosic, Anita; Boban, Mladen; Drenjancevic, Ines

2016-01-01

The effects of hyperbaric oxygenation (HBO₂) on acetylcholine-induced vasorelaxation (AChIR) were evaluated in male Sprague-Dawley (SD) rats randomized into four groups: healthy controls (Ctrl), diabetic rats (DM), and control and diabetic rats that underwent hyperbaric oxygenation (Ctrl+HBO₂ and DM+HBO₂). AChIR was measured in aortic rings, with L-NAME, indomethacin, or MS-PPOH and a combination of inhibitors. mRNA expression of eNOS, iNOS, COX-1 and COX-2 was assessed by qPCR, and protein expression of CYP4A(1-3) by Western blot. Plasma antioxidative capacity and systemic oxidative stress were determined with the ferric reducing ability of plasma (FRAP) and thiobarbituric acid-reactive substances (TBARS) assays, respectively. AChIR was preserved in all groups of rats, but mediated with different mechanisms. In all experimental groups of rats, AChIR was mediated mainly by NO, with the contribution of CYP450 vasodilator metabolites. This effect was the most prominent in the DM+HBO₂ group of rats. The TBARS was significantly higher in both DM and DM+HBO₂ groups compared to respective controls. eNOS expression was upregulated in the DM+HBO₂ group compared to other groups, COX-1 expression was upregulated in the DM+HBO₂ group compared to the control. CYP450-4A1 / A2/A3protein expression was significantly higher expressed in both hyperbaric groups compared to their respective controls. In conclusion, HBO₂ affected all three vasodilator pathways and shifted AChIR to CYP450 enzymes pathway. Copyright© Undersea and Hyperbaric Medical Society.

Reactive Oxygen Species Generated by NADPH Oxidases Promote Radicle Protrusion and Root Elongation during Rice Seed Germination

PubMed Central

Li, Wen-Yan; Chen, Bing-Xian; Chen, Zhong-Jian; Gao, Yin-Tao; Chen, Zhuang; Liu, Jun

2017-01-01

Seed germination is a complicated biological process that requires regulation through various enzymatic and non-enzymatic mechanisms. Although it has been recognized that reactive oxygen species (ROS) regulate radicle emergence and root elongation in a non-enzymatic manner during dicot seed germination, the role of ROS in monocot seed germination remains unknown. NADPH oxidases (NOXs) are the major ROS producers in plants; however, whether and how NOXs regulate rice seed germination through ROS generation remains unclear. Here, we report that diphenyleneiodinium (DPI), a specific NOX inhibitor, potently inhibited embryo and seedling growth—especially that of the radicle and of root elongation—in a dose-dependent manner. Notably, the DPI-mediated inhibition of radicle and root growth could be eliminated by transferring seedlings from DPI to water. Furthermore, ROS production/accumulation during rice seed germination was quantified via histochemistry. Superoxide radicals (O2−), hydrogen peroxide (H2O2) and hydroxyl radicals (•OH) accumulated steadily in the coleorhiza, radicle and seedling root of germinating rice seeds. Expression profiles of the nine typical NOX genes were also investigated. According to quantitative PCR, OsNOX5, 7 and 9 were expressed relatively higher. When seeds were incubated in water, OsNOX5 expression progressively increased in the embryo from 12 to 48 h, whereas OsNOX7 and 9 expressions increased from 12 to 24 h and decreased thereafter. As expected, DPI inhibits the expression at predetermined time points for each of these genes. Taken together, these results suggest that ROS produced by NOXs are involved in radicle and root elongation during rice seed germination, and OsNOX5, 7 and 9 could play crucial roles in rice seed germination. These findings will facilitate further studies of the roles of ROS generated by NOXs during seed germination and seedling establishment and also provide valuable information for the regulation of NOX family gene expression in germinating seeds of monocot cereals. PMID:28098759

Pleiotrophin-induced endothelial cell migration is regulated by xanthine oxidase-mediated generation of reactive oxygen species.

PubMed

Tsirmoula, Sotiria; Lamprou, Margarita; Hatziapostolou, Maria; Kieffer, Nelly; Papadimitriou, Evangelia

2015-03-01

Pleiotrophin (PTN) is a heparin-binding growth factor that induces cell migration through binding to its receptor protein tyrosine phosphatase beta/zeta (RPTPβ/ζ) and integrin alpha v beta 3 (ανβ3). In the present work, we studied the effect of PTN on the generation of reactive oxygen species (ROS) in human endothelial cells and the involvement of ROS in PTN-induced cell migration. Exogenous PTN significantly increased ROS levels in a concentration and time-dependent manner in both human endothelial and prostate cancer cells, while knockdown of endogenous PTN expression in prostate cancer cells significantly down-regulated ROS production. Suppression of RPTPβ/ζ through genetic and pharmacological approaches, or inhibition of c-src kinase activity abolished PTN-induced ROS generation. A synthetic peptide that blocks PTN-ανβ3 interaction abolished PTN-induced ROS generation, suggesting that ανβ3 is also involved. The latter was confirmed in CHO cells that do not express β3 or over-express wild-type β3 or mutant β3Y773F/Y785F. PTN increased ROS generation in cells expressing wild-type β3 but not in cells not expressing or expressing mutant β3. Phosphoinositide 3-kinase (PI3K) or Erk1/2 inhibition suppressed PTN-induced ROS production, suggesting that ROS production lays down-stream of PI3K or Erk1/2 activation by PTN. Finally, ROS scavenging and xanthine oxidase inhibition completely abolished both PTN-induced ROS generation and cell migration, while NADPH oxidase inhibition had no effect. Collectively, these data suggest that xanthine oxidase-mediated ROS production is required for PTN-induced cell migration through the cell membrane functional complex of ανβ3 and RPTPβ/ζ and activation of c-src, PI3K and ERK1/2 kinases. Copyright © 2015 Elsevier Inc. All rights reserved.

CYP2E1 induction leads to oxidative stress and cytotoxicity in glutathione-depleted cerebellar granule neurons.

PubMed

Valencia-Olvera, Ana Carolina; Morán, Julio; Camacho-Carranza, Rafael; Prospéro-García, Oscar; Espinosa-Aguirre, Jesús Javier

2014-10-01

Increasing evidence suggests that brain cytochrome P450 (CYP) can contribute to the in situ metabolism of xenobiotics. In the liver, some xenobiotics can be metabolized by CYPs into more reactive products that can damage hepatocytes and induce cell death. In addition, normal CYP activity may produce reactive oxygen species (ROS) that contribute to cell damage through oxidative mechanisms. CYP2E1 is a CYP isoform that can generate ROS leading to cytotoxicity in multiple tissue types. The aim of this study was to determine whether CYP2E1 induction may lead to significant brain cell impairment. Immunological analysis revealed that exposure of primary cerebellar granule neuronal cultures to the CYP inducer isoniazid, increased CYP2E1 expression. In the presence of buthionine sulfoximine, an agent that reduces glutathione levels, isoniazid treatment also resulted in reactive oxygen species (ROS) production, DNA oxidation and cell death. These effects were attenuated by simultaneous exposure to diallyl sulfide, a CYP2E1 inhibitor, or to a mimetic of superoxide dismutase/catalase, (Euka). These results suggest that in cases of reduced antioxidant levels, the induction of brain CYP2E1 could represent a risk of in situ neuronal damage. Copyright © 2014 Elsevier Ltd. All rights reserved.

Antioxidant enzyme expression and reactive oxygen species damage in prostatic intraepithelial neoplasia and cancer.

PubMed

Bostwick, D G; Alexander, E E; Singh, R; Shan, A; Qian, J; Santella, R M; Oberley, L W; Yan, T; Zhong, W; Jiang, X; Oberley, T D

2000-07-01

Oxidative stress results in damage to cellular structures and has been linked to many diseases, including cancer. The authors sought to determine whether the expression of three major antioxidant enzymes, copper-zinc superoxide dismutase (SOD1), manganese superoxide dismutase (SOD2), and catalase, was altered in human prostate carcinoma and its likely precursor, high grade prostatic intraepithelial neoplasia (PIN). The level of reactive oxygen species damage was evaluated by measuring the expression of the DNA adduct 8-hydroxydeoxyguanosine. The authors evaluated the tissue expression of the antioxidant enzymes in prostate carcinoma by immunohistochemistry, immunogold electron microscopy, and enzymatic assay. The polymerase chain reaction was used to amplify and screen tissue specimens for the genes of SOD1, SOD2, and extracellular SOD (SOD3). Matched paraffin embedded tissue sections were evaluated by RNA in situ hybridization for expression of SOD1 and immunohistochemically for the DNA adduct 8-hydroxydeoxyguanosine. All prostatic tissues, including cancer, displayed immunoreactivity for the three antioxidant enzymes in epithelial cells, with no staining of the stroma, inflammatory cells, or endothelial cells. The number of immunoreactive cells was greater in benign epithelium than in PIN and cancer for each enzyme. The mean percentage and intensity of immunoreactive cells was greatest for SOD2, intermediate for SOD1, and lower for catalase. Staining in cancer was heterogeneous. Immunogold ultrasound studies revealed strong mitochondrial labeling for SOD2, which was greater in benign epithelium than in cancer; SOD1 labeling was invariably weaker, with nuclear labeling in benign epithelium and cytoplasmic labeling in cancer cells. There was no difference in enzyme activity for the three antioxidant enzymes between benign epithelium and cancer. No mutations were found in the 5 exons of SOD1, 5 exons of SOD2, and 3 exons of SOD3, except for 3 of 20 cases with polymorphisms for exon 3 of SOD1. Intense nuclear immunoreactivity for 8-hydroxydeoxyguanosine was present in fewer than 3% of epithelial cells, with no apparent differences among benign epithelium, PIN, and cancer. SOD1, SOD2, and catalase had lower expression in PIN and prostate carcinoma than in benign epithelium. The number of immunoreactive cells in PIN was similar to cancer, indicating that these are closely related. Enzyme activities were variable, with no difference between benign epithelial cells and cancer, although this lack of change in enzyme activity could have been due to the presence of contaminating benign cells within the cancer specimens. The results of reactive oxygen species damage were found only in the epithelium and not in the stroma. Expression of the DNA adduct 8-hydroxydeoxyguanosine was present in fewer than 3% of cells, with no apparent differences among benign epithelium, PIN, and cancer. These findings suggest that oxidative stress is an early event in carcinogenesis. Copyright 2000 American Cancer Society.

Khz-cp (crude polysaccharide extract obtained from the fusion of Ganoderma lucidum and Polyporus umbellatus mycelia) induces apoptosis by increasing intracellular calcium levels and activating P38 and NADPH oxidase-dependent generation of reactive oxygen species in SNU-1 cells.

PubMed

Kim, Tae Hwan; Kim, Ju Sung; Kim, Zoo Haye; Huang, Ren Bin; Chae, Young Lye; Wang, Ren Sheng

2014-07-10

Khz-cp is a crude polysaccharide extract that is obtained after nuclear fusion in Ganoderma lucidum and Polyporus umbellatus mycelia (Khz). It inhibits the growth of cancer cells. Khz-cp was extracted by solvent extraction. The anti-proliferative activity of Khz-cp was confirmed by using Annexin-V/PI-flow cytometry analysis. Intracellular calcium increase and measurement of intracellular reactive oxygen species (ROS) were performed by using flow cytometry and inverted microscope. SNU-1 cells were treated with p38, Bcl-2 and Nox family siRNA. siRNA transfected cells was employed to investigate the expression of apoptotic, growth and survival genes in SNU-1 cells. Western blot analysis was performed to confirm the expression of the genes. In the present study, Khz-cp induced apoptosis preferentially in transformed cells and had only minimal effects on non-transformed cells. Furthermore, Khz-cp was found to induce apoptosis by increasing the intracellular Ca2+ concentration ([Ca2+]i) and activating P38 to generate reactive oxygen species (ROS) via NADPH oxidase and the mitochondria. Khz-cp-induced apoptosis was caspase dependent and occurred via a mitochondrial pathway. ROS generation by NADPH oxidase was critical for Khz-cp-induced apoptosis, and although mitochondrial ROS production was also required, it appeared to occur secondary to ROS generation by NADPH oxidase. Activation of NADPH oxidase was shown by the translocation of the regulatory subunits p47phox and p67phox to the cell membrane and was necessary for ROS generation by Khz-cp. Khz-cp triggered a rapid and sustained increase in [Ca2+]i that activated P38. P38 was considered to play a key role in the activation of NADPH oxidase because inhibition of its expression or activity abrogated membrane translocation of the p47phox and p67phox subunits and ROS generation. In summary, these data indicate that Khz-cp preferentially induces apoptosis in cancer cells and that the signaling mechanisms involve an increase in [Ca2+]i, P38 activation, and ROS generation via NADPH oxidase and mitochondria.

Neuroglobin protects astroglial cells from hydrogen peroxide-induced oxidative stress and apoptotic cell death.

PubMed

Amri, Fatma; Ghouili, Ikram; Amri, Mohamed; Carrier, Alice; Masmoudi-Kouki, Olfa

2017-01-01

Oxidative stress, resulting from accumulation of reactive oxygen species, plays a critical role in astroglial cell death occurring in diverse neuropathological conditions. Numerous studies indicate that neuroglobin (Ngb) promotes neuron survival, but nothing is known regarding the action of Ngb in astroglial cell survival. Thus, the purpose of this study was to investigate the potential glioprotective effect of Ngb on hydrogen peroxide (H 2 O 2 )-induced oxidative stress and apoptosis in cultured mouse astrocytes. Incubation of cells with subnanomolar concentrations of Ngb (10 -14 -10 -10  M) was found to prevent both H 2 O 2 -evoked reduction in surviving cells number and accumulation of reactive oxygen species in a concentration-dependent manner. Furthermore, Ngb treatment abolishes H 2 O 2 -induced increase in mitochondrial oxygen consumption rates. Concomitantly, Ngb treatment rescues H 2 O 2 -associated reduced expression of endogenous antioxidant enzymes (superoxide dismutases and catalase) and prevents the stimulation of the expression of pro-inflammatory genes (inducible nitric oxide synthase, cyclooxygenase-2, and interleukin (IL) IL-6 and IL-33). Moreover, Ngb blocks the stimulation of Bax (pro-apoptotic) and the inhibition of Bcl-2 (anti-apoptotic) gene expression induced by H 2 O 2 , which in turn abolishes caspase 3 activation. The protective effect of Ngb upon H 2 O 2 induced activation of caspase 3 activity and cell death can be accounted for by activation of protein kinase A and mitogen-activated protein kinase transduction cascade. Finally, we demonstrate that Ngb increases Akt phosphorylation and prevents H 2 O 2 -provoked inhibition of ERK and Akt phosphorylation. Taken together, these data demonstrate for the first time that Ngb is a glioprotective agent that prevents H 2 O 2 -induced oxidative stress and apoptotic astroglial cell death. Protection of astrocytes from oxidative insult may thus contribute to the neuroprotective effect of Ngb. © 2016 International Society for Neurochemistry.

The Synergistic Effect of Proteins and Reactive Oxygen Species on Electrochemical Behaviour of 316L Stainless Steel for Biomedical Applications

NASA Astrophysics Data System (ADS)

Simionescu, N.; Benea, L.; Dumitrascu, V. M.

2018-06-01

The stainless steels, especially 316L type is the most used metallic biomaterials for biomedical applications due to their good biocompatibility, low price, excellent corrosion resistance, availability, easy processing and high strength. Due to these favorable properties 316L stainless steel has become the most attractive biomaterial for dental implants, stents and orthopedic implants. However an implant material in the human body is exposed to an action effect of other molecules, including proteins (such as albumin) and reactive oxygen species (such as hydrogen peroxide - H2O2 ) produced by bacteria and immune cells. In the literature there are few studies to follow the effect of proteins and reactive oxygen species on 316L stainless steel used as implant material and are still unclear. The degree of corrosion resistance is the first criterion in the use of a metallic biomaterial in the oral or body environment. The aim of this research work is to investigate the influence of proteins (albumin) and reactive oxygen species (H2O2 ) in combination, taking into account the synergistic effect of these two factors on 316L stainless steel. Albumin is present in the body near implants and reactive oxygen species could appear in inflammatory processes as well. The study shows that the presence of albumin and reactive species influences the corrosion resistance of 316L stainless steel in biological solutions. In this research work the corrosion behavior of 316L stainless steel is analyzed by electrochemical methods such as: open circuit potential (OCP), Electrochemical Impedance Spectroscopy (EIS). It was found that, the electrochemical results are in a good agreement with micro photographs taken before and after corrosion assays. The albumin and reactive oxygen species have influence on 316L stainless steel behavior.

Sulforaphane protects against acrolein-induced oxidative stress and inflammatory responses: modulation of Nrf-2 and COX-2 expression.

PubMed

Qin, Wang-Sen; Deng, Yu-Hui; Cui, Fa-Cai

2016-08-01

Acrolein (2-propenal) is a reactive α, β-unsaturated aldehyde which causes a health hazard to humans. The present study focused on determining the protection offered by sulforaphane against acrolein-induced damage in peripheral blood mononuclear cells (PBMC). Acrolein-induced oxidative stress was determined through evaluating the levels of reactive oxygen species, protein carbonyl and sulfhydryl content, thiobarbituric acid reactive species, total oxidant status and antioxidant status (total antioxidant capacity, glutathione, superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase activity). Also, Nrf-2 expression levels were determined using western blot analysis. Acrolein-induced inflammation was determined through analyzing expression of cyclooxygenase-2 by western blot and PGE2 levels by ELISA. The protection offered by sulforaphane against acrolein-induced oxidative stress and inflammation was studied. Acrolein showed a significant (p < 0.001) increase in the levels of oxidative stress parameters and down-regulated Nrf-2 expression. Acrolein-induced inflammation was observed through upregulation (p < 0.001) of COX-2 and PGE2 levels. Pretreatment with sulforaphane enhanced the antioxidant status through upregulating Nrf-2 expression (p < 0.001) in PBMC. Acrolein-induced inflammation was significantly inhibited through suppression of COX-2 (p < 0.001) and PGE2 levels (p < 0.001). The present study provides clear evidence that pre-treatment with sulforaphane completely restored the antioxidant status and prevented inflammatory responses mediated by acrolein. Thus the protection offered by sulforaphane against acrolein-induced damage in PBMC is attributed to its anti-oxidant and anti-inflammatory potential.

Are soluble factors relevant for polymorphonuclear leukocyte dysregulation in septicemia?

PubMed Central

Wenisch, C; Graninger, W

1995-01-01

Polymorphonuclear leukocytes (PMNs) of twelve patients with gram-negative septicemia exhibited a decreased capacity to phagocytize Escherichia coli and generate reactive oxygen products which normalized within 7 days of treatment. Ex vivo exchange of plasma from age-, sex-, and blood-group-identical normal controls resulted in an increase of both phagocytic capacity and reactive oxygen intermediate generation in PMNs of septicemic patients and transiently reduced phagocytosis and reactive oxygen intermediate production in PMNs of normal controls. These results suggest that extrinsic factors are crucial for PMN function. PMID:7697538

Rosacea, Reactive Oxygen Species, and Azelaic Acid

PubMed Central

2009-01-01

Rosacea is a common skin condition thought to be primarily an inflammatory disorder. Neutrophils, in particular, have been implicated in the inflammation associated with rosacea and mediate many of their effects through the release of reactive oxygen species. Recently, the role of reactive oxygen species in the pathophysiology of rosacea has been recognized. Many effective agents for rosacea, including topical azelaic acid and topical metronidazole, have anti-inflammatory properties. in-vitro models have demonstrated the potent antioxidant effects of azelaic acid, providing a potential mechanistic explanation for its efficacy in the treatment of rosacea. PMID:20967185

Rosacea, reactive oxygen species, and azelaic Acid.

PubMed

Jones, David A

2009-01-01

Rosacea is a common skin condition thought to be primarily an inflammatory disorder. Neutrophils, in particular, have been implicated in the inflammation associated with rosacea and mediate many of their effects through the release of reactive oxygen species. Recently, the role of reactive oxygen species in the pathophysiology of rosacea has been recognized. Many effective agents for rosacea, including topical azelaic acid and topical metronidazole, have anti-inflammatory properties. in-vitro models have demonstrated the potent antioxidant effects of azelaic acid, providing a potential mechanistic explanation for its efficacy in the treatment of rosacea.

Roles of oxyanions in promoting the partial oxidation of styrene on Ag(110): nitrate, carbonate, sulfite, and sulfate.

PubMed

Zhou, Ling; Madix, Robert J

2010-11-02

The promotion roles of nitrate, carbonate, sulfite, and sulfate in oxidation of styrene on Ag(110) have been studied by means of temperature-programmed reaction spectroscopy (TPRS) and X-ray photoelectron spectroscopy (XPS). While isolated nitrate leads only to the secondary oxidation of styrene, a surface co-covered by nitrate, oxygen, and 0.1 ML cesium promotes a low-temperature epoxidation pathway. XPS indicates that adsorbed surface oxygen is the oxidant in this selective reaction pathway, and, though it affects the reactivity of the surface oxygen, nitrate is a spectator. Carbonate acts as an oxygen transfer agent and exhibits similar reactivity and selectivity as an oxidant for styrene as does atomic oxygen on Ag(110). The reactivities of sulfite and sulfate are strongly dependent on their surface structures, the c(6 × 2) sulfite showing the capacity to transfer oxygen to styrene.

Induction of apoptosis by N-(4-hydroxyphenyl)retinamide and its association with reactive oxygen species, nuclear retinoic acid receptors, and apoptosis-related genes in human prostate carcinoma cells.

PubMed

Sun, S Y; Yue, P; Lotan, R

1999-03-01

The synthetic retinoid N-(4-hydroxyphenyl)retinamide (4HPR) has been shown to induce apoptosis in various malignant cells including human prostate carcinoma cells (HPC). We examined several possible mechanisms by which 4HPR could induce apoptosis in HPC cells. 4HPR exhibited concentration- and time-dependent decrease in cell number both in androgen-dependent (LNCaP) and -independent (DU145 and PC-3) cells. The 4HPR concentrations causing 50% decrease in cell number in LNCaP, DU145, and PC-3 cultures were 0.9 +/- 0.16, 4.4 +/- 0.45, and 3.0 +/- 1.0 microM, respectively, indicating that LNCaP cells were more sensitive to 4HPR than the other cells. 4HPR-induced apoptosis in all three cell lines was evidenced by increased enzymatic labeling of DNA breaks and formation of a DNA ladder. 4HPR increased the level of reactive oxygen species, especially in LNCaP cells. 4HPR-induced apoptosis could be suppressed in LNCaP cells by antioxidant and in DU145 cells by a nuclear retinoic acid receptor-specific antagonist, suggesting the involvement of reactive oxygen species or retinoic acid receptors in mediating apoptosis induced by 4HPR in the different HPC cells. Furthermore, 4HPR modulated the expression levels of some apoptosis-related gene (p21, c-myc, and c-jun), which may also contribute to the induction of apoptosis by 4HPR in HPC cells.

Antibiotics induce redox-related physiological alterations as part of their lethality

PubMed Central

Dwyer, Daniel J.; Belenky, Peter A.; Yang, Jason H.; MacDonald, I. Cody; Martell, Jeffrey D.; Takahashi, Noriko; Chan, Clement T. Y.; Lobritz, Michael A.; Braff, Dana; Schwarz, Eric G.; Ye, Jonathan D.; Pati, Mekhala; Vercruysse, Maarten; Ralifo, Paul S.; Allison, Kyle R.; Khalil, Ahmad S.; Ting, Alice Y.; Walker, Graham C.; Collins, James J.

2014-01-01

Deeper understanding of antibiotic-induced physiological responses is critical to identifying means for enhancing our current antibiotic arsenal. Bactericidal antibiotics with diverse targets have been hypothesized to kill bacteria, in part by inducing production of damaging reactive species. This notion has been supported by many groups but has been challenged recently. Here we robustly test the hypothesis using biochemical, enzymatic, and biophysical assays along with genetic and phenotypic experiments. We first used a novel intracellular H2O2 sensor, together with a chemically diverse panel of fluorescent dyes sensitive to an array of reactive species to demonstrate that antibiotics broadly induce redox stress. Subsequent gene-expression analyses reveal that complex antibiotic-induced oxidative stress responses are distinct from canonical responses generated by supraphysiological levels of H2O2. We next developed a method to quantify cellular respiration dynamically and found that bactericidal antibiotics elevate oxygen consumption, indicating significant alterations to bacterial redox physiology. We further show that overexpression of catalase or DNA mismatch repair enzyme, MutS, and antioxidant pretreatment limit antibiotic lethality, indicating that reactive oxygen species causatively contribute to antibiotic killing. Critically, the killing efficacy of antibiotics was diminished under strict anaerobic conditions but could be enhanced by exposure to molecular oxygen or by the addition of alternative electron acceptors, indicating that environmental factors play a role in killing cells physiologically primed for death. This work provides direct evidence that, downstream of their target-specific interactions, bactericidal antibiotics induce complex redox alterations that contribute to cellular damage and death, thus supporting an evolving, expanded model of antibiotic lethality. PMID:24803433

Protective Role of Mitochondrial Peroxiredoxin III against UVB-Induced Apoptosis of Epidermal Keratinocytes.

PubMed

Baek, Jin Young; Park, Sujin; Park, Jiyoung; Jang, Ji Yong; Wang, Su Bin; Kim, Sin Ri; Woo, Hyun Ae; Lim, Kyung Min; Chang, Tong-Shin

2017-06-01

UVB light induces generation of reactive oxygen species, ultimately leading to skin cell damage. Mitochondria are a major source of reactive oxygen species in UVB-irradiated skin cells, with increased levels of mitochondrial reactive oxygen species having been implicated in keratinocyte apoptosis. Peroxiredoxin III (PrxIII) is the most abundant and potent H 2 O 2 -removing enzyme in the mitochondria of most cell types. Here, the protective role of PrxIII against UVB-induced apoptosis of epidermal keratinocytes was investigated. Mitochondrial H 2 O 2 levels were differentiated from other types of ROS using mitochondria-specific fluorescent H 2 O 2 indicators. Upon UVB irradiation, PrxIII-knockdown HaCaT human keratinocytes and PrxIII-deficient (PrxIII -/- ) mouse primary keratinocytes exhibited enhanced accumulation of mitochondrial H 2 O 2 compared with PrxIII-expressing controls. Keratinocytes lacking PrxIII were subsequently sensitized to apoptosis through mitochondrial membrane potential loss, cardiolipin oxidation, cytochrome c release, and caspase activation. Increased UVB-induced epidermal tissue damage in PrxIII -/- mice was attributable to increased caspase-dependent keratinocyte apoptosis. Our findings show that mitochondrial H 2 O 2 is a key mediator in UVB-induced apoptosis of keratinocytes and that PrxIII plays a critical role in protecting epidermal keratinocytes against UVB-induced apoptosis through eliminating mitochondrial H 2 O 2 . These findings support the concept that reinforcing mitochondrial PrxIII defenses may help prevent UVB-induced skin damage such as inflammation, sunburn, and photoaging. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Microcystin-LR Induced Reactive Oxygen Species Mediate Cytoskeletal Disruption and Apoptosis of Hepatocytes in Cyprinus carpio L.

PubMed Central

Jiang, Jinlin; Shan, Zhengjun; Xu, Weili; Wang, Xiaorong; Zhou, Junying; Kong, Deyang; Xu, Jing

2013-01-01

Microcystins (MCs) are a group of cyclic hepatotoxic peptides produced by cyanobacteria. Microcystin-LR (MC-LR) contains Leucine (L) and Arginine (R) in the variable positions, and is one of the most common and potently toxic peptides. MC-LR can inhibit protein phosphatase type 1 and type 2A (PP1 and PP2A) activities and induce excessive production of reactive oxygen species (ROS). The underlying mechanism of the inhibition of PP1 and PP2A has been extensively studied. The over-production of ROS is considered to be another main mechanism behind MC-LR toxicity; however, the detailed toxicological mechanism involved in over-production of ROS in carp (Cyprinus carpio L.) remains largely unclear. In our present study, the hydroxyl radical (•OH) was significantly induced in the liver of carp after a relatively short-term exposure to MC-LR. The elevated reactive oxygen species (ROS) production may play an important role in the disruption of microtubule structure. Pre-injection of the antioxidant N-acetyl-cysteine (NAC) provided significant protection to the cytoskeleton, however buthionine sulfoximine (BSO) exacerbated cytoskeletal destruction. In addition, the elevated ROS formation induced the expression of apoptosis-related genes, including p38, JNKa, and bcl-2. A significant increase in apoptotic cells was observed at 12 - 48 hours. Our study further supports evidence that ROS are involved in MC-LR induced damage to liver cells in carp, and indicates the need for further study of the molecular mechanisms behind MC-LR toxicity. PMID:24376844

The neuroprotective role and mechanisms of TERT in neurons with oxygen-glucose deprivation.

PubMed

Li, J; Qu, Y; Chen, D; Zhang, L; Zhao, F; Luo, L; Pan, L; Hua, J; Mu, D

2013-11-12

Telomerase reverse transcriptase (TERT) is reported to protect neurons from apoptosis induced by various stresses including hypoxia-ischemia (HI). However, the mechanisms by which TERT exerts its anti-apoptotic role in neurons with HI injury remain unclear. In this study, we examined the protective role and explored the possible mechanisms of TERT in neurons with HI injury in vitro. Primary cultured neurons were exposed to oxygen and glucose deprivation (OGD) for 3h followed by reperfusion to mimic HI injury in vivo. Plasmids containing TERT antisense, sense nucleotides, or mock were transduced into neurons at 48h before OGD. Expression and distribution of TERT were measured by immunofluorescence labeling and western blot. The expression of cleaved caspase 3 (CC3), Bcl-2 and Bax were detected by western blot. Neuronal apoptosis was measured with terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL). The mitochondrial reactive oxygen species (ROS) were measured by MitoSOX Red staining. Fluorescent probe JC-1 was used to measure the mitochondrial membrane potential (ΔΨm). We found that TERT expression increased at 8h and peaked at 24h in neurons after OGD. CC3 expression and neuronal apoptosis were induced and peaked at 24h after OGD. TERT inhibition significantly increased CC3 expression and neuronal apoptosis after OGD treatment. Additionally, TERT inhibition decreased the expression ratio of Bcl-2/Bax, and enhanced ROS production and ΔΨm dissipation after OGD. These data suggest that TERT plays a neuroprotective role via anti-apoptosis in neurons after OGD. The underlying mechanisms may be associated with regulating Bcl-2/Bax expression ratio, attenuating ROS generation, and increasing mitochondrial membrane potential. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

3-Hydroxybutyrate regulates energy metabolism and induces BDNF expression in cerebral cortical neurons.

PubMed

Marosi, Krisztina; Kim, Sang Woo; Moehl, Keelin; Scheibye-Knudsen, Morten; Cheng, Aiwu; Cutler, Roy; Camandola, Simonetta; Mattson, Mark P

2016-12-01

During fasting and vigorous exercise, a shift of brain cell energy substrate utilization from glucose to the ketone 3-hydroxybutyrate (3OHB) occurs. Studies have shown that 3OHB can protect neurons against excitotoxicity and oxidative stress, but the underlying mechanisms remain unclear. Neurons maintained in the presence of 3OHB exhibited increased oxygen consumption and ATP production, and an elevated NAD + /NADH ratio. We found that 3OHB metabolism increases mitochondrial respiration which drives changes in expression of brain-derived neurotrophic factor (BDNF) in cultured cerebral cortical neurons. The mechanism by which 3OHB induces Bdnf gene expression involves generation of reactive oxygen species, activation of the transcription factor NF-κB, and activity of the histone acetyltransferase p300/EP300. Because BDNF plays important roles in synaptic plasticity and neuronal stress resistance, our findings suggest cellular signaling mechanisms by which 3OHB may mediate adaptive responses of neurons to fasting, exercise, and ketogenic diets. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Lignans from Opuntia ficus-indica seeds protect rat primary hepatocytes and HepG2 cells against ethanol-induced oxidative stress.

PubMed

Kim, Jung Wha; Yang, Heejung; Kim, Hyeon Woo; Kim, Hong Pyo; Sung, Sang Hyun

2017-01-01

Bioactivity-guided isolation of Opuntia ficus-indica (Cactaceae) seeds against ethanol-treated primary rat hepatocytes yielded six lignan compounds. Among the isolates, furofuran lignans 4-6, significantly protected rat hepatocytes against ethanol-induced oxidative stress by reducing intracellular reactive oxygen species levels, preserving antioxidative defense enzyme activities, and maintaining the glutathione content. Moreover, 4 dose-dependently induced the heme oxygenase-1 expression in HepG2 cells.

Aquaporin8 regulates cellular development and reactive oxygen species production, a critical component of virulence in Botrytis cinerea.

PubMed

An, Bang; Li, Boqiang; Li, Hua; Zhang, Zhanquan; Qin, Guozheng; Tian, Shiping

2016-03-01

Aquaporins (AQPs) are ubiquitous in nearly all organisms, mediating selective and rapid flux of water across biological membranes. The role of AQPs in phytopathogenic fungi is poorly understood. Orthologs of AQP genes in Botrytis cinerea were identified and knocked out. The effects of AQPs on hyphal growth and conidiation, formation of infection structures and virulence on plant hosts were examined. The role of AQP8 in reactive oxygen species (ROS) production, distribution and transport were further determined. Among eight AQPs, only AQP8 was essential for the ability of B. cinerea to infect plants. AQP8 was demonstrated to be an intrinsic plasma membrane protein, which may function as a channel and mediate hydrogen peroxide uptake. Deletion of AQP8 in B. cinerea completely inhibited the development of conidia and infection structures, and significantly affected noxR expression. Further observations revealed that both AQP8 and noxR impacted ROS distribution in the hyphal tips of B. cinerea. Moreover, AQP8 affected the expression of a mitochondrial protein, NQO1. A knockout mutant of NQO1 was observed to display reduced virulence. These data lead to a better understanding of the important role of AQP8 in the development and pathogenesis of plant pathogens. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Biologically synthesized silver nanoparticles induce neuronal differentiation of SH-SY5Y cells via modulation of reactive oxygen species, phosphatases, and kinase signaling pathways.

PubMed

Dayem, Ahmed Abdal; Kim, BongWoo; Gurunathan, Sangiliyandi; Choi, Hye Yeon; Yang, Gwangmo; Saha, Subbroto Kumar; Han, Dawoon; Han, Jihae; Kim, Kyeongseok; Kim, Jin-Hoi; Cho, Ssang-Goo

2014-07-01

Nano-scale materials are noted for unique properties, distinct from those of their bulk material equivalents. In this study, we prepared spherical silver nanoparticles (AgNPs) with an average size of about 30 nm and tested their potency to induce neuronal differentiation of SH-SY5Y cells. Human neuroblastoma SH-SY5Y cells are considered an ideal in vitro model for studying neurogenesis, as they can be maintained in an undifferentiated state or be induced to differentiate into neuron-like phenotypes in vitro by several differentiation-inducing agents. Treatment of SH-SY5Y cells by biologically synthesized AgNPs led to cell morphological changes and significant increase in neurite length and enhanced the expression of neuronal differentiation markers such as Map-2, β-tubulin III, synaptophysin, neurogenin-1, Gap-43, and Drd-2. Furthermore, we observed an increase in generation of intracellular reactive oxygen species (ROS), activation of several kinases such as ERK and AKT, and downregulation of expression of dual-specificity phosphatases (DUSPs) in AgNPs-exposed SH-SY5Y cells. Our results suggest that AgNPs modulate the intracellular signaling pathways, leading to neuronal differentiation, and could be applied as promising nanomaterials for stem cell research and therapy. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Net superoxide levels: steeper increase with activity in cooler female and hotter male lizards.

PubMed

Ballen, Cissy; Healey, Mo; Wilson, Mark; Tobler, Michael; Wapstra, Erik; Olsson, Mats

2012-03-01

Ectotherms increase their body temperature in response to ambient heat, thereby elevating their metabolic rate. An often inferred consequence of this is an overall upregulation of gene expression and energetic expenditure, and a concomitant increased production of reactive oxygen species (e.g. superoxide) and, perhaps, a shortened lifespan. However, recent work shows that this may be a superficial interpretation. For example, sometimes a reduced temperature may in fact trigger up-regulation of gene expression. We studied temperature and associated activity effects in male and female Australian painted dragon lizards (Ctenophorus pictus) by allowing the lizards to bask for 4 h versus 12 h, and scoring their associated activity (inactive versus active basking and foraging). As predicted, long-basking lizards (hereafter 'hot') showed heightened activity in both sexes, with a more pronounced effect in females. We then tested for sex-specific effects of basking treatment and activity levels on the increase in net levels of superoxide. In males, short-baskers (hereafter 'cold') had significantly more rapidly decreasing levels of superoxide per unit increasing activity than hot males. In females, however, superoxide levels increased faster with increasing activity in the cold than in the hot basking treatment, and females earlier in the ovarian cycle had lower superoxide levels than females closer to ovulation. In short, males and females differ in how their levels of reactive oxygen species change with temperature-triggered activity.

Caspase 1 activation is protective against hepatocyte cell death by up-regulating beclin 1 protein and mitochondrial autophagy in the setting of redox stress.

PubMed

Sun, Qian; Gao, Wentao; Loughran, Patricia; Shapiro, Rick; Fan, Jie; Billiar, Timothy R; Scott, Melanie J

2013-05-31

Caspase 1 activation can be induced by oxidative stress, which leads to the release of the proinflammatory cytokines IL1β and IL18 in myeloid cells and a potentially damaging inflammatory response. However, little is known about the role of caspase 1 in non-immune cells, such as hepatocytes, that express and activate the inflammasome but do not produce a significant amount of IL1β/IL18. Here we demonstrate that caspase 1 activation protects against cell death after redox stress induced by hypoxia/reoxygenation in hepatocytes. Mechanistically, we show that caspase 1 reduces mitochondrial respiration and reactive oxygen species by increasing mitochondrial autophagy and subsequent clearance of mitochondria in hepatocytes after hypoxia/reoxygenation. Caspase 1 increases autophagic flux through up-regulating autophagy initiator beclin 1 during redox stress and is an important cell survival factor in hepatocytes. We find that during hemorrhagic shock with resuscitation, an in vivo mouse model associated with severe hepatic redox stress, caspase 1 activation is also protective against liver injury and excessive oxidative stress through the up-regulation of beclin 1. Our findings suggest an alternative role for caspase 1 activation in promoting adaptive responses to oxidative stress and, more specifically, in limiting reactive oxygen species production and damage in cells and tissues where IL1β/IL18 are not highly expressed.

Caspase 1 Activation Is Protective against Hepatocyte Cell Death by Up-regulating Beclin 1 Protein and Mitochondrial Autophagy in the Setting of Redox Stress*

PubMed Central

Sun, Qian; Gao, Wentao; Loughran, Patricia; Shapiro, Rick; Fan, Jie; Billiar, Timothy R.; Scott, Melanie J.

2013-01-01

Caspase 1 activation can be induced by oxidative stress, which leads to the release of the proinflammatory cytokines IL1β and IL18 in myeloid cells and a potentially damaging inflammatory response. However, little is known about the role of caspase 1 in non-immune cells, such as hepatocytes, that express and activate the inflammasome but do not produce a significant amount of IL1β/IL18. Here we demonstrate that caspase 1 activation protects against cell death after redox stress induced by hypoxia/reoxygenation in hepatocytes. Mechanistically, we show that caspase 1 reduces mitochondrial respiration and reactive oxygen species by increasing mitochondrial autophagy and subsequent clearance of mitochondria in hepatocytes after hypoxia/reoxygenation. Caspase 1 increases autophagic flux through up-regulating autophagy initiator beclin 1 during redox stress and is an important cell survival factor in hepatocytes. We find that during hemorrhagic shock with resuscitation, an in vivo mouse model associated with severe hepatic redox stress, caspase 1 activation is also protective against liver injury and excessive oxidative stress through the up-regulation of beclin 1. Our findings suggest an alternative role for caspase 1 activation in promoting adaptive responses to oxidative stress and, more specifically, in limiting reactive oxygen species production and damage in cells and tissues where IL1β/IL18 are not highly expressed. PMID:23589298

Autophagy Facilitates IFN-γ-induced Jak2-STAT1 Activation and Cellular Inflammation*

PubMed Central

Chang, Yu-Ping; Tsai, Cheng-Chieh; Huang, Wei-Ching; Wang, Chi-Yun; Chen, Chia-Ling; Lin, Yee-Shin; Kai, Jui-In; Hsieh, Chia-Yuan; Cheng, Yi-Lin; Choi, Pui-Ching; Chen, Shun-Hua; Chang, Shih-Ping; Liu, Hsiao-Sheng; Lin, Chiou-Feng

2010-01-01

Autophagy is regulated for IFN-γ-mediated antimicrobial efficacy; however, its molecular effects for IFN-γ signaling are largely unknown. Here, we show that autophagy facilitates IFN-γ-activated Jak2-STAT1. IFN-γ induces autophagy in wild-type but not in autophagy protein 5 (Atg5−/−)-deficient mouse embryonic fibroblasts (MEFs), and, autophagy-dependently, IFN-γ induces IFN regulatory factor 1 and cellular inflammatory responses. Pharmacologically inhibiting autophagy using 3-methyladenine, a known inhibitor of class III phosphatidylinositol 3-kinase, confirms these effects. Either Atg5−/− or Atg7−/− MEFs are, independent of changes in IFN-γ receptor expression, resistant to IFN-γ-activated Jak2-STAT1, which suggests that autophagy is important for IFN-γ signal transduction. Lentivirus-based short hairpin RNA for Atg5 knockdown confirmed the importance of autophagy for IFN-γ-activated STAT1. Without autophagy, reactive oxygen species increase and cause SHP2 (Src homology-2 domain-containing phosphatase 2)-regulated STAT1 inactivation. Inhibiting SHP2 reversed both cellular inflammation and the IFN-γ-induced activation of STAT1 in Atg5−/− MEFs. Our study provides evidence that there is a link between autophagy and both IFN-γ signaling and cellular inflammation and that autophagy, because it inhibits the expression of reactive oxygen species and SHP2, is pivotal for Jak2-STAT1 activation. PMID:20592027

Sea Buckthorn Leaf Extract Inhibits Glioma Cell Growth by Reducing Reactive Oxygen Species and Promoting Apoptosis.

PubMed

Kim, Sung-Jo; Hwang, Eunmi; Yi, Sun Shin; Song, Ki Duk; Lee, Hak-Kyo; Heo, Tae-Hwe; Park, Sang-Kyu; Jung, Yun Joo; Jun, Hyun Sik

2017-08-01

Hippophae rhamnoides L., also known as sea buckthorn (SBT), possesses a wide range of biological and pharmacological activities. However, the underlying mechanism is largely unknown. The present study examined whether SBT leaf extract could inhibit proliferation and promote apoptosis of rat glioma C6 cells. The results revealed that the treatment with SBT leaf extract inhibited proliferation of rat C6 glioma cells in a dose-dependent manner. SBT-induced reduction of C6 glioma cell proliferation and viability was accompanied by a decrease in production of reactive oxygen species (ROS), which are critical for the proliferation of tumor cells. SBT treatment not only significantly upregulated the expression of the pro-apoptotic protein Bcl-2-associated X (Bax) but also promoted its localization in the nucleus. Although increased expression and nuclear translocation of Bax were observed in SBT-treated C6 glioma cells, the induced nuclear morphological change was distinct from that of typical apoptotic cells in that most of SBT-treated cells were characterized by convoluted nuclei with cavitations and clumps of chromatin. All of these results suggest that SBT leaf extract could inhibit the rapid proliferation of rat C6 glioma cells, possibly by inducing the early events of apoptosis. Thus, SBT may serve as a potential therapeutic candidate for the treatment of glioma.

[Comparative effects of vitamin C on the effects of local anesthetics ropivacaine, bupivacaine, and lidocaine on human chondrocytes].

PubMed

Tian, Jun; Li, Yan

2016-01-01

Intra-articular injections of local anesthetics are commonly used to enhance post-operative analgesia following orthopedic surgery as arthroscopic surgeries. Nevertheless, recent reports of severe complications due to the use of intra-articular local anesthetic have raised concerns. The study aims to assess use of vitamin C in reducing adverse effects of the most commonly employed anesthetics - ropivacaine, bupivacaine and lidocaine - on human chondrocytes. The chondrocyte viability following exposure to 0.5% bupivacaine or 0.75% ropivacaine or 1.0% lidocaine and/or vitamin C at doses 125, 250 and 500μM was determined by Live/Dead assay and annexin V staining. Expression levels of caspases 3 and 9 were assessed using antibodies by Western blotting. Flow cytometry was performed to analyze the generation of reactive oxygen species. On exposure to the local anesthetics, chondrotoxicity was found in the order ropivacaine

Comparative effects of vitamin C on the effects of local anesthetics ropivacaine, bupivacaine, and lidocaine on human chondrocytes.

PubMed

Tian, Jun; Li, Yan

2016-01-01

Intra-articular injections of local anesthetics are commonly used to enhance post-operative analgesia following orthopedic surgery as arthroscopic surgeries. Nevertheless, recent reports of severe complications due to the use of intra-articular local anesthetic have raised concerns. The study aims to assess use of vitamin C in reducing adverse effects of the most commonly employed anesthetics - ropivacaine, bupivacaine and lidocaine - on human chondrocytes. The chondrocyte viability following exposure to 0.5% bupivacaine or 0.75% ropivacaine or 1.0% lidocaine and/or vitamin C at doses 125, 250 and 500 μM was determined by LIVE/DEAD assay and annexin V staining. Expression levels of caspases 3 and 9 were assessed using antibodies by Western blotting. Flow cytometry was performed to analyze the generation of reactive oxygen species. On exposure to the local anesthetics, chondrotoxicity was found in the order ropivacaine

Iron induces bimodal population development by Escherichia coli

PubMed Central

DePas, William H.; Hufnagel, David A.; Lee, John S.; Blanco, Luz P.; Bernstein, Hans C.; Fisher, Steve T.; James, Garth A.; Stewart, Philip S.; Chapman, Matthew R.

2013-01-01

Bacterial biofilm formation is a complex developmental process involving cellular differentiation and the formation of intricate 3D structures. Here we demonstrate that exposure to ferric chloride triggers rugose biofilm formation by the uropathogenic Escherichia coli strain UTI89 and by enteric bacteria Citrobacter koseri and Salmonella enterica serovar typhimurium. Two unique and separable cellular populations emerge in iron-triggered, rugose biofilms. Bacteria at the air–biofilm interface express high levels of the biofilm regulator csgD, the cellulose activator adrA, and the curli subunit operon csgBAC. Bacteria in the interior of rugose biofilms express low levels of csgD and undetectable levels of matrix components curli and cellulose. Iron activation of rugose biofilms is linked to oxidative stress. Superoxide generation, either through addition of phenazine methosulfate or by deletion of sodA and sodB, stimulates rugose biofilm formation in the absence of high iron. Additionally, overexpression of Mn-superoxide dismutase, which can mitigate iron-derived reactive oxygen stress, decreases biofilm formation in a WT strain upon iron exposure. Not only does reactive oxygen stress promote rugose biofilm formation, but bacteria in the rugose biofilms display increased resistance to H2O2 toxicity. Altogether, we demonstrate that iron and superoxide stress trigger rugose biofilm formation in UTI89. Rugose biofilm development involves the elaboration of two distinct bacterial populations and increased resistance to oxidative stress. PMID:23359678

Chlorogenic Acid from Hawthorn Berry (Crataegus pinnatifida Fruit) Prevents Stress Hormone-Induced Depressive Behavior, Through Monoamine Oxidase B-reactive Oxygen Species Signaling in Hippocampal Astrocytes of Mice.

PubMed

Lim, Dong Wook; Han, Taewon; Jung, Jonghoon; Song, Yuri; Um, Min Young; Yoon, Minseok; Kim, Yun Tai; Cho, Seungmok; Kim, In-Ho; Han, Daeseok; Lee, Changho; Lee, Jaekwang

2018-06-12

Oxidative stress has been implicated in mental disorders, including depression. Chlorogenic acid (CGA), a phenolic compound abundant in herbs and fruits, has been reported to have antioxidant and free-radical scavenging properties. In this study, we investigated the antidepressant-like effects and active mechanisms of CGA from the extract of Crataegus pinnatifida (CP) fruit. Depression-like phenotypes were induced in mice by daily injection of stress hormone for 1-2 weeks. The brains of these animals exhibited reduced brain-derived neurotrophic factor (BDNF) expression and increased astrocytic hypertrophy, which are typical markers of depression in animal models. Stress hormone injection 1) upregulated monoamine oxidase B (MAOB) expression and 2) reduced spine numbers along neuronal dendrites, which indicates synaptic depression. The oral administration of CGA (30 mg/kg) or CP (300 mg/kg) prevented MAOB activation following reactive oxygen species (ROS) production and had an ameliorative effect on depressive behavioral tests (e.g., tail suspension and forced swim tests). In vitro assays performed on cultured C8-D1A cells revealed that CGA and CP inhibited MAOB activity and ROS production. Our study indicates that CGA and CP extracts prevented depressive behavior and thereby have potential as natural antidepressants. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

The protective effects of Rhodiola crenulata extracts on Drosophila melanogaster gut immunity induced by bacteria and SDS toxicity.

PubMed

Zhu, Caixia; Guan, Fachun; Wang, Chao; Jin, Li Hua

2014-12-01

The aim of this study was to observe the effect of the Rhodiola crenulata extracts on gut immunity of Drosophila melanogaster. Wild-type flies fed standard cornmeal-yeast medium were used as controls. Experimental groups were supplemented with 2.5% R. crenulata aqueous extracts in standard medium. Survival rate was determined by feeding pathogenic microorganisms and toxic compounds. The levels of reactive oxygen species and dead cells were detected by dihydroethidium and 7-amino-actinomycin D staining, respectively. The expression of antimicrobial peptides was evaluated by quantitative polymerase chain reaction, and morphological change of the intestine was imaged by an Axioskop 2 plus microscope. The results demonstrate that R. crenulata increased the survival rates of adult flies and expression of antimicrobial peptide genes after pathogen or toxic compound ingestion. Moreover, decreased levels of reactive oxygen species and epithelial cell death were associated with results in improved intestinal morphology. The pharmacological action of R. crenulata from Tibet was greater than that from Sichuan. These results indicate that the R. crenulata extracts from Tibet had better pharmacological effect on D. melanogaster gut immunity after ingestion of pathogens and toxic compounds. These results may provide the pharmacological basis for prevention of inflammatory diseases of the intestine. Copyright © 2014 John Wiley & Sons, Ltd.

Chronic restraint stress inhibits hair growth via substance P mediated by reactive oxygen species in mice.

PubMed

Liu, Nan; Wang, Lin-Hui; Guo, Ling-Ling; Wang, Guo-Qing; Zhou, Xi-Ping; Jiang, Yan; Shang, Jing; Murao, Koji; Chen, Jing-Wei; Fu, Wen-Qing; Zhang, Guo-Xing

2013-01-01

Solid evidence has demonstrated that psychoemotional stress induced alteration of hair cycle through neuropeptide substance P (SP) mediated immune response, the role of reactive oxygen species (ROS) in brain-skin-axis regulation system remains unknown. The present study aims to investigate possible mechanisms of ROS in regulation of SP-mast cell signal pathway in chronic restraint stress (CRS, a model of chronic psychoemotional stress) which induced abnormal of hair cycle. Our results have demonstrated that CRS actually altered hair cycle by inhibiting hair follicle growth in vivo, prolonging the telogen stage and delaying subsequent anagen and catagen stage. Up-regulation of SP protein expression in cutaneous peripheral nerve fibers and activation of mast cell were observed accompanied with increase of lipid peroxidation levels and reduction of the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in CRS mice skin. In addition, SP receptor antagonist (RP67580) reduced mast cell activations and lipid peroxidation levels as well as increased GSH-Px activity and normalized hair cycle. Furthermore, antioxidant Tempol (a free radical scavenger) also restored hair cycle, reduced SP protein expression and mast cell activation. Our study provides the first solid evidence for how ROS play a role in regulation of psychoemotional stress induced SP-Mast cell pathway which may provide a convincing rationale for antioxidant application in clinical treatment with psychological stress induced hair loss.

Glycidamide inhibits progesterone production through reactive oxygen species-induced apoptosis in R2C Rat Leydig Cells.

PubMed

Li, Mingwei; Sun, Jianxia; Zou, Feiyan; Bai, Shun; Jiang, Xinwei; Jiao, Rui; Ou, Shiyi; Zhang, Hui; Su, Zhijian; Huang, Yadong; Bai, Weibin

2017-10-01

The food contaminant acrylamide (AA) is usually recognized as a probable human carcinogen. In addition, AA has also been found able to induce male infertility in animals. Interestingly, resent research work revealed that the toxic effect of AA on the ability of male reproduction in vivo may due to glycidamide (GA) which is the metabolite of AA. In this study, R2C Leydig cells was used to investigate the toxic effects of GA on progesterone production. GA caused dose-dependent inhibition on the cell growth, with IC 25 , IC 50, and IC 75 values found at 0.635, 0.872, and 1.198 mM, respectively. The results of single cell gel/Comet assay showed that GA significantly induced early-phase cell apoptosis, reduced progesterone production, as well as decreasing the protein expression of steroidogenic acute regulatory (StAR) in R2C cells. Furthermore, GA induced overproduction of intracellular reactive oxygen species (ROS), upregulated Bax expression, decreased mitochondrial membrane potential, and triggered mitochondria-mediated cell apoptosis. Consequently, the downstream effector caspase-3 was activated, resulting in Leydig cells apoptosis. Overall, our results showed that GA could damage R2C Leydig cells by the lesion of the ability of progesterone genesis and inducing cells apoptosis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ionizing radiation accelerates Drp1-dependent mitochondrial fission, which involves delayed mitochondrial reactive oxygen species production in normal human fibroblast-like cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kobashigawa, Shinko, E-mail: kobashin@nagasaki-u.ac.jp; Suzuki, Keiji; Yamashita, Shunichi

2011-11-04

Highlights: Black-Right-Pointing-Pointer We report first time that ionizing radiation induces mitochondrial dynamic changes. Black-Right-Pointing-Pointer Radiation-induced mitochondrial fission was caused by Drp1 localization. Black-Right-Pointing-Pointer We found that radiation causes delayed ROS from mitochondria. Black-Right-Pointing-Pointer Down regulation of Drp1 rescued mitochondrial dysfunction after radiation exposure. -- Abstract: Ionizing radiation is known to increase intracellular level of reactive oxygen species (ROS) through mitochondrial dysfunction. Although it has been as a basis of radiation-induced genetic instability, the mechanism involving mitochondrial dysfunction remains unclear. Here we studied the dynamics of mitochondrial structure in normal human fibroblast like cells exposed to ionizing radiation. Delayed mitochondrial O{submore » 2}{sup {center_dot}-} production was peaked 3 days after irradiation, which was coupled with accelerated mitochondrial fission. We found that radiation exposure accumulated dynamin-related protein 1 (Drp1) to mitochondria. Knocking down of Drp1 expression prevented radiation induced acceleration of mitochondrial fission. Furthermore, knockdown of Drp1 significantly suppressed delayed production of mitochondrial O{sub 2}{sup {center_dot}-}. Since the loss of mitochondrial membrane potential, which was induced by radiation was prevented in cells knocking down of Drp1 expression, indicating that the excessive mitochondrial fission was involved in delayed mitochondrial dysfunction after irradiation.« less

Ethylene Response Factor TERF1, Regulated by ETHYLENE-INSENSITIVE3-like Factors, Functions in Reactive Oxygen Species (ROS) Scavenging in Tobacco (Nicotiana tabacum L.).

PubMed

Zhang, Hongbo; Li, Ang; Zhang, Zhijin; Huang, Zejun; Lu, Pingli; Zhang, Dingyu; Liu, Xinmin; Zhang, Zhong-Feng; Huang, Rongfeng

2016-07-20

The phytohormone ethylene plays a crucial role in the production and accumulation of reactive oxygen species (ROS) in plants under stress conditions. Ethylene response factors (ERFs) are important ethylene-signaling regulators functioning in plant defense responses against biotic and abiotic stresses. However, the roles of ERFs during plant adapting to ROS stress have not yet been well documented. Our studies previously reported that a tomato ERF transcription factor TERF1 functions in the regulation of plant ethylene responses and stress tolerance. Here, we report our findings regarding the roles of TERF1 in ROS scavenging. In this study, we revealed that the transcription of TERF1 is regulated by upstream EIN3-like (EIN3, ethylene-insensitive 3) regulators LeEIL3 and LeEIL4 in tomato (Solanum lycopersicum), and is also inducible by exogenous applied ROS-generating reagents. Ectopic expression of TERF1 in tobacco promoted the expression of genes involved in oxidative stress responses, including carbonic anhydrase functioning in hypersensitive defense, catalase and glutathione peroxidase catalyzing oxidative reactions, and GDP-D-mannose pyrophosphorylase functioning in ascorbic acid biosynthesis, reduced the ROS content induced by ethylene treatment, and enhanced stress tolerance of tobacco seedlings to hydrogen peroxide (H2O2). Cumulatively, these findings suggest that TERF1 is an ethylene inducible factor regulating ROS scavenging during stress responses.

Resistance-breaking population of Meloidogyne incognita utilizes plant peroxidase to scavenge reactive oxygen species, thereby promoting parasitism on tomato carrying Mi-1 gene.

PubMed

Guan, Tinglong; Shen, Jinhua; Fa, Yang; Su, Yishi; Wang, Xuan; Li, Hongmei

2017-01-01

Resistance conferred by the Mi-1 gene from Solanum peruvianum is effective and widely used for controlling root-knot nematodes (RKNs, Meloidogyne spp.). However, breakdown of resistance by RKNs seriously threatens the durable application of the resistance resource. Here, a resistance-breaking population of M. incognita was selected from an avirulent population by continuously inoculating on Mi-1-carrying tomato. Histological observations showed the resistance-breaking population would not induce hypersensitive response (HR) when infecting Mi-1-carrying tomato, while avirulent population did. A total of 308 differentially expressed genes (DEGs) were identified from Mi-1-carrying tomato upon infection with resistance-breaking versus avirulent populations by RNA-seq. The expression patterns of 23 selected DEGs were validated by quantitative real-time PCR (qRT-PCR). Subsequently, seven out of nine highly up-regulated DEGs were successfully knocked down in Mi-1-carrying tomato by tobacco rattle virus (TRV) mediated RNAi. The TRV line targeting a peroxidase gene showed a much higher magnitude of reactive oxygen species (ROS) and distinct reduction of pathogenicity upon infection of the resistance-breaking population compared with that of TRV::gfp line. Our results suggested that plant peroxidase might be exploited by resistance-breaking population of M. incognita to scavenge ROS, so as to overcome Mi-1-mediated resistance. Copyright © 2016 Elsevier Inc. All rights reserved.

Concurrent suppression of NF-κB, p38 MAPK and reactive oxygen species formation underlies the effect of a novel compound isolated from Curcuma comosa Roxb. in LPS-activated microglia.

PubMed

Jiamvoraphong, Nittaya; Jantaratnotai, Nattinee; Sanvarinda, Pantip; Tuchinda, Patoomratana; Piyachaturawat, Pawinee; Thampithak, Anusorn; Sanvarinda, Pimtip

2017-07-01

We investigated the molecular mechanisms underlying the effect of (3S)-1-(3,4-dihydroxyphenyl)-7-phenyl-(6E)-6-hepten-3-ol, also known as compound 092, isolated from Curcuma comosa Roxb on the production of pro-inflammatory mediators and oxidative stress in lipopolysaccharide (LPS)-activated highly aggressive proliferating immortalized (HAPI) microglial cell lines. Nitric oxide (NO) production was determined using the Griess reaction, and reverse transcription polymerase chain reaction was used to measure the expression of inducible nitric oxide synthase (iNOS) mRNA. Western blotting was used to determine the levels of pro-inflammatory mediators and their related upstream proteins. Compound 092 suppressed NO production and iNOS expression in LPS-stimulated HAPI cells. These effects originated from the ability of compound 092 to attenuate the activation of nuclear factor (NF)-κB as determined by the reduction in p-NF-κB and p-IκB kinase (IKK) protein levels. Compound 092 also significantly lowered LPS-activated intracellular reactive oxygen species production and p38 mitogen-activated protein kinase (MAPK) activation. Compound 092 suppresses microglial activation through attenuation of p38 MAPK and NF-κB activation. Compound 092 thus holds the potential to treat neurodegenerative disorders associated with neuroinflammation and oxidative stress. © 2017 Royal Pharmaceutical Society.

Effect of additive oxygen gas on cellular response of lung cancer cells induced by atmospheric pressure helium plasma jet

PubMed Central

Joh, Hea Min; Choi, Ji Ye; Kim, Sun Ja; Chung, T. H.; Kang, Tae-Hong

2014-01-01

The atmospheric pressure helium plasma jet driven by pulsed dc voltage was utilized to treat human lung cancer cells in vitro. The properties of plasma plume were adjusted by the injection type and flow rate of additive oxygen gas in atmospheric pressure helium plasma jet. The plasma characteristics such as plume length, electric current and optical emission spectra (OES) were measured at different flow rates of additive oxygen to helium. The plasma plume length and total current decreased with an increase in the additive oxygen flow rate. The electron excitation temperature estimated by the Boltzmann plot from several excited helium emission lines increased slightly with the additive oxygen flow. The oxygen atom density in the gas phase estimated by actinometry utilizing argon was observed to increase with the additive oxygen flow. The concentration of intracellular reactive oxygen species (ROS) measured by fluorescence assay was found to be not exactly proportional to that of extracellular ROS (measured by OES), but both correlated considerably. It was also observed that the expression levels of p53 and the phospho-p53 were enhanced in the presence of additive oxygen flow compared with those from the pure helium plasma treatment. PMID:25319447

Reagents that block neuronal death from Huntington's disease also curb oxidative stress.

PubMed

Valencia, Antonio; Sapp, Ellen; Reeves, Patrick B; Alexander, Jonathan; Masso, Nicholas; Li, Xueyi; Kegel, Kimberly B; DiFiglia, Marian

2012-01-04

Patients with Huntington's disease suffer severe neuronal loss and signs of oxidative damage in the brain. Previously we found that primary neurons from embryonic cortex of mice bearing the Huntington's disease mutation (140 glutamines inserted into exon 1 of huntingtin) showed higher levels of reactive oxygen species before cell death. Here, we treated mutant neurons with known neuroprotective agents and determined the effects on neuronal survival and levels of reactive oxygen species. Primary neurons were exposed to the neurotrophin, brain derived neurotrophic factor, the antioxidant N-acetyl-cysteine or a specific inhibitor of glycogen synthase kinase 3-β, SB216763. Each reagent increased the survival of the mutant neurons compared with untreated mutant neurons and also reduced the levels of reactive oxygen species to levels of wild-type neurons. These results suggest that reducing the levels of reactive oxygen species may be necessary to protect neurons with the Huntington's disease mutation from cell death.

Manipulation of arginase expression modulates abiotic stress tolerance in Arabidopsis: effect on arginine metabolism and ROS accumulation

PubMed Central

Chan, Zhulong

2013-01-01

Arginine is an important medium for the transport and storage of nitrogen, and arginase (also known as arginine amidohydrolase, ARGAH) is responsible for catalyse of arginine into ornithine and urea in plants. In this study, the impact of AtARGAHs on abiotic stress response was investigated by manipulating AtARGAHs expression. In the knockout mutants of AtARGAHs, enhanced tolerances were observed to multiple abiotic stresses including water deficit, salt, and freezing stresses, while AtARGAH1- and AtARGAH2-overexpressing lines exhibited reduced abiotic stress tolerances compared to the wild type. Consistently, the enhanced tolerances were confirmed by the changes of physiological parameters including electrolyte leakage, water loss rate, stomatal aperture, and survival rate. Interestingly, the direct downstream products of arginine catabolism including polyamines and nitric oxide (NO) concentrations significantly increased in the AtARGAHs-knockout lines, but decreased in overexpressing lines under control conditions. Additionally, the AtARGAHs-overexpressing and -knockout lines displayed significantly reduced relative arginine (% of total free amino acids) relative to the wild type. Similarly, reactive oxygen species accumulation was remarkably regulated by AtARGAHs under abiotic stress conditions, as shown from hydrogen peroxide (H2O2), superoxide radical () concentrations, and antioxidant enzyme activities. Taken together, this is the first report, as far as is known, to provide evidence that AtARGAHs negatively regulate many abiotic stress tolerances, at least partially, attribute to their roles in modulating arginine metabolism and reactive oxygen species accumulation. Biotechnological strategy based on manipulation of AtARGAHs expression will be valuable for future crop breeding. PMID:23378380

Arsenite induces endothelial cell permeability increase through a reactive oxygen species-vascular endothelial growth factor pathway.

PubMed

Bao, Lingzhi; Shi, Honglian

2010-11-15

As a potent environmental oxidative stressor, arsenic exposure has been reported to exacerbate cardiovascular diseases and increase vascular endothelial cell monolayer permeability. However, the underlying mechanism of this effect is not well understood. In this paper, we test our hypothesis that reactive oxygen species (ROS)-induced vascular endothelial growth factor (VEGF) expression may play an important role in an arsenic-caused increase of endothelial cell monolayer permeability. The mouse brain vascular endothelial cell bEnd3 monolayer was exposed to arsenite for 1, 3, and 6 days. The monolayer permeability, VEGF protein release, and ROS generation were determined. In addition, VE-cadherin and zonula occludens-1 (ZO-1), two membrane structure proteins, were immunostained to elucidate the effects of arsenite on the cell-cell junction. The roles of ROS and VEGF in arsenite-induced permeability was determined by inhibiting ROS with antioxidants and immuno-depleting VEGF with a VEGF antibody. We observed that arsenite increased bEnd3 monolayer permeability, elevated the production of cellular ROS, and increased VEGF release. VE-cadherin and ZO-1 disruptions were also found in cells treated with arsenite. Furthermore, both antioxidant (N-acetyl cysteine and tempol) and the VEGF antibody treatments significantly lowered the arsenite-induced permeability of the bEnd3 monolayer as well as VEGF expression. VE-cadherin and ZO-1 disruptions were also diminished by N-acetyl cysteine and the VEGF antibody. Our data suggest that the increase in VEGF expression caused by ROS may play an important role in the arsenite-induced increase in endothelial cell permeability.

GbTCP, a cotton TCP transcription factor, confers fibre elongation and root hair development by a complex regulating system.

PubMed

Hao, Juan; Tu, Lili; Hu, Haiyan; Tan, Jiafu; Deng, Fenglin; Tang, Wenxin; Nie, Yichun; Zhang, Xianlong

2012-10-01

As the most important natural raw material for textile industry, cotton fibres are an excellent model for studying single-cell development. Although expression profiling and functional genomics have provided some data, the mechanism of fibre development is still not well known. A class I TCP transcription factor (designated GbTCP), encoding 344 amino acids, was isolated from the normalized cDNA library of sea-island cotton fibre (from -2 to 25 days post anthesis). GbTCP was preferentially expressed in the elongating cotton fibre from 5 to 15 days post anthesis. Some expression was also observed in stems, apical buds, and petals. RNAi silencing of GbTCP produced shorter fibre, a reduced lint percentage, and a lower fibre quality than the wild-type plants. Overexpression of GbTCP enhanced root hair initiation and elongation in Arabidopsis and regulated branching. Solexa sequencing and Affymetrix GeneChip analysis indicated that GbTCP positively regulates the level of jasmonic acid (JA) and, as a result, activates downstream genes (reactive oxygen species, calcium signalling, ethylene biosynthesis and response, and several NAC and WRKY transcription factors) necessary for elongation of fibres and root hairs. JA content analysis in cotton also confirmed that GbTCP has a profound effect on JA biosynthesis. In vitro ovule culture showed that an appropriate concentration of JA promoted fibre elongation. The results suggest that GbTCP is an important transcription factor for fibre and root hair development by regulating JA biosynthesis and response and other pathways, including reactive oxygen species, calcium channel and ethylene signalling.

GbTCP, a cotton TCP transcription factor, confers fibre elongation and root hair development by a complex regulating system

PubMed Central

Zhang, Xianlong

2012-01-01

As the most important natural raw material for textile industry, cotton fibres are an excellent model for studying single-cell development. Although expression profiling and functional genomics have provided some data, the mechanism of fibre development is still not well known. A class I TCP transcription factor (designated GbTCP), encoding 344 amino acids, was isolated from the normalized cDNA library of sea-island cotton fibre (from –2 to 25 days post anthesis). GbTCP was preferentially expressed in the elongating cotton fibre from 5 to 15 days post anthesis. Some expression was also observed in stems, apical buds, and petals. RNAi silencing of GbTCP produced shorter fibre, a reduced lint percentage, and a lower fibre quality than the wild-type plants. Overexpression of GbTCP enhanced root hair initiation and elongation in Arabidopsis and regulated branching. Solexa sequencing and Affymetrix GeneChip analysis indicated that GbTCP positively regulates the level of jasmonic acid (JA) and, as a result, activates downstream genes (reactive oxygen species, calcium signalling, ethylene biosynthesis and response, and several NAC and WRKY transcription factors) necessary for elongation of fibres and root hairs. JA content analysis in cotton also confirmed that GbTCP has a profound effect on JA biosynthesis. In vitro ovule culture showed that an appropriate concentration of JA promoted fibre elongation. The results suggest that GbTCP is an important transcription factor for fibre and root hair development by regulating JA biosynthesis and response and other pathways, including reactive oxygen species, calcium channel and ethylene signalling. PMID:23105133

Puerarin ameliorates heat stress-induced oxidative damage and apoptosis in bovine Sertoli cells by suppressing ROS production and upregulating Hsp72 expression.

PubMed

Cong, Xia; Zhang, Qian; Li, Huatao; Jiang, Zhongling; Cao, Rongfeng; Gao, Shansong; Tian, Wenru

2017-01-15

Puerarin, a bioactive isoflavone glucoside extracted from radix Puerariae, has been proven to possess many biological activities. However, the role of puerarin in protecting bovine Sertoli cells (bSCs) under heat stress conditions remains to be clarified. The present study aimed to explore the possible protective mechanism of puerarin for primary cultured bSCs subjected to heat stress. Bovine Sertoli cells were treated with 15 μM of puerarin before they were exposed to 42 °C for 1 hour. The dose of puerarin (15 μM) was determined on the basis of cell viability. The results showed that puerarin treatment suppressed the production of reactive oxygen species and decreased the oxidative damage of the bSCs subjected to heat stress, as indicated by changes in superoxide dismutase, catalase, and glutathione peroxidase activities and malondialdehyde content. Moreover, puerarin treatment also suppressed the initiation of mitochondria-dependent apoptotic pathway, as revealed by changes in Bax to Bcl-2 ratio, mitochondrial membrane potential, cytochrome C release, caspase-3 activation, and apoptotic rate compared with the heat stress group. In addition, puerarin treatment increased Hsp72 expression in the bSCs with no apparent cellular cytotoxicity compared with the control group. Furthermore, increased Hsp72 was detected in the heat stress plus puerarin group compared with the heat stress group. In conclusion, puerarin attenuates heat stress-induced oxidative damage and apoptosis of bSCs by suppressing reactive oxygen species production and upregulating Hsp72 expression. Copyright © 2016 Elsevier Inc. All rights reserved.

Cannabidiol-induced apoptosis in human leukemia cells: A novel role of cannabidiol in the regulation of p22phox and Nox4 expression.

PubMed

McKallip, Robert J; Jia, Wentao; Schlomer, Jerome; Warren, James W; Nagarkatti, Prakash S; Nagarkatti, Mitzi

2006-09-01

In the current study, we examined the effects of the nonpsychoactive cannabinoid, cannabidiol, on the induction of apoptosis in leukemia cells. Exposure of leukemia cells to cannabidiol led to cannabinoid receptor 2 (CB2)-mediated reduction in cell viability and induction in apoptosis. Furthermore, cannabidiol treatment led to a significant decrease in tumor burden and an increase in apoptotic tumors in vivo. From a mechanistic standpoint, cannabidiol exposure resulted in activation of caspase-8, caspase-9, and caspase-3, cleavage of poly(ADP-ribose) polymerase, and a decrease in full-length Bid, suggesting possible cross-talk between the intrinsic and extrinsic apoptotic pathways. The role of the mitochondria was further suggested as exposure to cannabidiol led to loss of mitochondrial membrane potential and release of cytochrome c. It is noteworthy that cannabidiol exposure led to an increase in reactive oxygen species (ROS) production as well as an increase in the expression of the NAD(P)H oxidases Nox4 and p22(phox). Furthermore, cannabidiol-induced apoptosis and reactive oxygen species (ROS) levels could be blocked by treatment with the ROS scavengers or the NAD(P)H oxidase inhibitors. Finally, cannabidiol exposure led to a decrease in the levels of p-p38 mitogen-activated protein kinase, which could be blocked by treatment with a CB2-selective antagonist or ROS scavenger. Together, the results from this study reveal that cannabidiol, acting through CB2 and regulation of Nox4 and p22(phox) expression, may be a novel and highly selective treatment for leukemia.

Hyperglycemia-induced mouse trophoblast spreading is mediated by reactive oxygen species.

PubMed

Sánchez-Santos, Alejandra; Martínez-Hernández, María G; Contreras-Ramos, Alejandra; Ortega-Camarillo, Clara; Baiza-Gutman, Luis A

2018-04-01

During embryo implantation, the outer layer of the blastocyst interacts with the endometrium giving rise to the development of the trophoblast cell lineage. The cells in this lineage participate in the penetration of endometrium due to their motility and invasive properties. The mechanisms that regulate the differentiation and invasive ability of these cells are essential for the establishment and maintenance of an efficient exchange between maternal and fetal tissues during pregnancy. In this context, hyperglycemia can induce oxidative stress causing alterations in the placenta. This study evaluated the role of reactive oxygen species (ROS) in the actions of high glucose concentration (HG) on trophoblast spreading and the expression of extracellular proteases in cultured mouse conceptuses. Blastocysts from gestational day 4 (GD4) were cultured until GD7 in HAM-F10 medium and further treated for 48 hr with HG (25 mM glucose) from GD7 to GD9. This treatment induced larger trophoblast outgrowths and increased ROS concentration, which was associated with increased expression levels of urokinase-type plasminogen activator (PLAU), plasminogen activator inhibitor 1 (PAI-1), and matrix metalloproteinase 9 (MMP-9). These effects were prevented by treatment with the non-specific antioxidant N-acetylcysteine (NAC) or apocynin, an inhibitor of NADPH oxidase. Our data suggest that the HG-induced trophoblast spreading and the expression of PLAU, PAI-1, and MMP-9 were mediated by the production of ROS via NADPH oxidase activity. Our results shed light on placental alterations in gestational diabetes mellitus. © 2018 Wiley Periodicals, Inc.

Transient Transcriptional Regulation of the CYS-C1 Gene and Cyanide Accumulation upon Pathogen Infection in the Plant Immune Response1[C][W

PubMed Central

García, Irene; Rosas, Tábata; Bejarano, Eduardo R.; Gotor, Cecilia; Romero, Luis C.

2013-01-01

Cyanide is produced concomitantly with ethylene biosynthesis. Arabidopsis (Arabidopsis thaliana) detoxifies cyanide primarily through the enzyme β-cyanoalanine synthase, mainly by the mitochondrial CYS-C1. CYS-C1 loss of function is not toxic for the plant and leads to an increased level of cyanide in cys-c1 mutants as well as a root hairless phenotype. The classification of genes differentially expressed in cys-c1 and wild-type plants reveals that the high endogenous cyanide content of the cys-c1 mutant is correlated with the biotic stress response. Cyanide accumulation and CYS-C1 gene expression are negatively correlated during compatible and incompatible plant-bacteria interactions. In addition, cys-c1 plants present an increased susceptibility to the necrotrophic fungus Botrytis cinerea and an increased tolerance to the biotrophic Pseudomonas syringae pv tomato DC3000 bacterium and Beet curly top virus. The cys-c1 mutation produces a reduction in respiration rate in leaves, an accumulation of reactive oxygen species, and an induction of the alternative oxidase AOX1a and pathogenesis-related PR1 expression. We hypothesize that cyanide, which is transiently accumulated during avirulent bacterial infection and constitutively accumulated in the cys-c1 mutant, uncouples the respiratory electron chain dependent on the cytochrome c oxidase, and this uncoupling induces the alternative oxidase activity and the accumulation of reactive oxygen species, which act by stimulating the salicylic acid-dependent signaling pathway of the plant immune system. PMID:23784464

Anti-apoptotic and myocardial protective effects of ethyl pyruvate after regional ischaemia/reperfusion myocardial damage in an in vivo rat model.

PubMed

Shim, Haeng Seon; Lee, Wang Gyu; Kim, Yeon A; Han, Jeong Yeol; Park, Miyeong; Song, Yun Gyu; Kim, Joon Soo; Shin, Il-Woo

2017-09-01

The integration of reactive oxygen species is strongly associated with important pathophysiological mechanisms that mediate myocardial ischaemia/reperfusion (I/R) damage. Pyruvate is an efficacious scavenger of reactive oxygen species and a previous study has shown that ethyl pyruvate (EP) has a myocardial protective effect against regional I/R damage in an in vivo rat model. The purpose of this study was to determine whether the myocardial protective effect of EP is associated with anti-apoptosis. Rats were allocated to receive EP dissolved in lactated Ringer's solution or lactated Ringer's solution alone, via intraperitoneal infusion one hour before ischaemia. They were exposed to 30 minutes of ischaemia followed by reperfusion of the left coronary artery territory over two hours. Anti-apoptotic effects were checked using several biochemical parameters after two hours of reperfusion. Apoptosis was analysed using measured caspase-3 activity, Western blotting of B-cell lymphoma 2 (Bcl-2) family protein cleaved by caspase-3, and assessment of DNA laddering patterns and the terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) staining test. In ischaemic myocardium, EP increased Bcl-2 expression, but reduced Bcl-2-associated X protein and cleaved caspase-3 expressions. EP reduced the expression of DNA laddering and the number of myocardial I/R-damaged TUNEL-positive cells. This study demonstrated that EP has an anti-apoptotic effect after regional I/R damage in an in vivo rat heart model. The myocardial protective effect of EP may be related to its anti-apoptotic effect. Copyright: © Singapore Medical Association

Zinc oxide nanoparticles decrease the expression and activity of plasma membrane calcium ATPase, disrupt the intracellular calcium homeostasis in rat retinal ganglion cells.

PubMed

Guo, Dadong; Bi, Hongsheng; Wang, Daoguang; Wu, Qiuxin

2013-08-01

Zinc oxide nanoparticle is one of the most important materials with diverse applications. However, it has been reported that zinc oxide nanoparticles are toxic to organisms, and that oxidative stress is often hypothesized to be an important factor in cytotoxicity mediated by zinc oxide nanoparticles. Nevertheless, the mechanism of toxicity of zinc oxide nanoparticles has not been completely understood. In this study, we investigated the cytotoxic effect of zinc oxide nanoparticles and the possible molecular mechanism involved in calcium homeostasis mediated by plasma membrane calcium ATPase in rat retinal ganglion cells. Real-time cell electronic sensing assay showed that zinc oxide nanoparticles could exert cytotoxic effect on rat retinal ganglion cells in a concentration-dependent manner; flow cytometric analysis indicated that zinc oxide nanoparticles could lead to cell damage by inducing the overproduction of reactive oxygen species. Furthermore, zinc oxide nanoparticles could also apparently decrease the expression level and their activity of plasma membrane calcium ATPase, which finally disrupt the intracellular calcium homeostasis and result in cell death. Taken together, zinc oxide nanoparticles could apparently decrease the plasma membrane calcium ATPase expression, inhibit their activity, cause the elevated intracellular calcium ion level and disrupt the intracellular calcium homeostasis. Further, the disrupted calcium homeostasis will trigger mitochondrial dysfunction, generate excessive reactive oxygen species, and finally initiate cell death. Thus, the disrupted calcium homeostasis is involved in the zinc oxide nanoparticle-induced rat retinal ganglion cell death. Copyright © 2013 Elsevier Ltd. All rights reserved.

Cytological and Proteomic Analyses of Osmunda cinnamomea Germinating Spores Reveal Characteristics of Fern Spore Germination and Rhizoid Tip Growth.

PubMed

Suo, Jinwei; Zhao, Qi; Zhang, Zhengxiu; Chen, Sixue; Cao, Jian'guo; Liu, Guanjun; Wei, Xing; Wang, Tai; Yang, Chuanping; Dai, Shaojun

2015-09-01

Fern spore is a good single-cell model for studying the sophisticated molecular networks in asymmetric cell division, differentiation, and polar growth. Osmunda cinnamomea L. var. asiatica is one of the oldest fern species with typical separate-growing trophophyll and sporophyll. The chlorophyllous spores generated from sporophyll can germinate without dormancy. In this study, the spore ultrastructure, antioxidant enzyme activities, as well as protein and gene expression patterns were analyzed in the course of spore germination at five typical stages (i.e. mature spores, rehydrated spores, double-celled spores, germinated spores, and spores with protonemal cells). Proteomic analysis revealed 113 differentially expressed proteins, which were mainly involved in photosynthesis, reserve mobilization, energy supplying, protein synthesis and turnover, reactive oxygen species scavenging, signaling, and cell structure modulation. The presence of multiple proteoforms of 25 differentially expressed proteins implies that post-translational modification may play important roles in spore germination. The dynamic patterns of proteins and their encoding genes exhibited specific characteristics in the processes of cell division and rhizoid tip growth, which include heterotrophic and autotrophic metabolisms, de novo protein synthesis and active protein turnover, reactive oxygen species and hormone (brassinosteroid and ethylene) signaling, and vesicle trafficking and cytoskeleton dynamic. In addition, the function skew of proteins in fern spores highlights the unique and common mechanisms when compared with evolutionarily divergent spermatophyte pollen. These findings provide an improved understanding of the typical single-celled asymmetric division and polar growth during fern spore germination. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Branched-chain amino acids reduce hepatic iron accumulation and oxidative stress in hepatitis C virus polyprotein-expressing mice

PubMed Central

Korenaga, Masaaki; Nishina, Sohji; Korenaga, Keiko; Tomiyama, Yasuyuki; Yoshioka, Naoko; Hara, Yuichi; Sasaki, Yusuke; Shimonaka, Yasushi; Hino, Keisuke

2015-01-01

Background & Aims Branched-chain amino acids (BCAA) reduce the incidence of hepatocellular carcinoma (HCC) in patients with cirrhosis. However, the mechanisms that underlie these effects remain unknown. Previously, we reported that oxidative stress in male transgenic mice that expressed hepatitis C virus polyprotein (HCVTgM) caused hepatic iron accumulation by reducing hepcidin transcription, thereby leading to HCC development. This study investigated whether long-term treatment with BCAA reduced hepatic iron accumulation and oxidative stress in iron-overloaded HCVTgM and in patients with HCV-related advanced fibrosis. Methods Male HCVTgM were fed an excess-iron diet that comprised either casein or 3.0% BCAA, or a control diet, for 6 months. Results For HCVTgM, BCAA supplementation increased the serum hepcidin-25 levels and antioxidant status [ratio of biological antioxidant potential (BAP) relative to derivatives of reactive oxygen metabolites (dROM)], decreased the hepatic iron contents, attenuated reactive oxygen species generation, and restored mitochondrial superoxide dismutase expression and mitochondrial complex I activity in the liver compared with mice fed the control diet. After 48 weeks of BCAA supplementation in patients with HCV-related advanced fibrosis, BAP/dROM and serum hepcidin-25 increased and serum ferritin decreased compared with the pretreatment levels. Conclusions BCAA supplementation reduced oxidative stress by restoring mitochondrial function and improved iron metabolism by increasing hepcidin-25 in both iron-overloaded HCVTgM and patients with HCV-related advanced fibrosis. These activities of BCAA may partially account for their inhibitory effects on HCC development in cirrhosis patients. PMID:25156780

Beta-hydroxybutyrate increases reactive oxygen species in late but not in early postimplantation embryonic cells in vitro.

PubMed

Forsberg, H; Eriksson, U J; Melefors, O; Welsh, N

1998-02-01

Embryonic dysmorphogenesis has been blocked by antioxidant treatment in vivo and in vitro, suggesting that embryonic excess of reactive oxygen species (ROS) has a role in the teratogenic process of diabetic pregnancy. We report that the basal levels of ROS in dispersed rat embryonic cells in vitro, as determined by fluorescence of dichlorofluorescein (DCF), were not different in cells from control and diabetic pregnancy at day 10 or 12. Beta-hydroxybutyrate (beta-HB) and succinic acid monomethyl ester both augmented DCF fluorescence in cells from day 12 embryos of normal and diabetic rats but not from day 10 embryos. Cells of day 10 and day 12 embryos from normal and diabetic rats responded to increasing glucose concentrations with a dosage-dependent alleviation of DCF fluorescence. Day 10 embryonic cells exhibited high glucose utilization rates and high pentose phosphate shunt rates, but low mitochondrial oxidation rates. Moreover, in vitro culture of embryos between gestational days 9 and 10 in the presence of 20% oxygen induced an increased and glucose-sensitive oxidation of glucose compared with embryos not cultured in vitro. At gestation day 12, however, pentose phosphate shunt rates showed a decrease, whereas the mitochondrial beta-HB oxidation rates were increased compared with those at gestation day 10. This was paralleled by a lower expression of glucose 6-phosphate dehydrogenase- and phosphofructokinase-mRNA levels at day 12 than at day 10. On the other hand, H-ferritin mRNA expression at day 12 was high compared with day 10. None of the mRNA species investigated were affected by the diabetic state of the mother. It was concluded that beta-HB-induced stimulation of mitochondrial oxidative events may lead to the generation of ROS at gestational day 12, but probably not at day 10, when only a minute amount of mitochondrial activity occurs. Thus our results do not support the notion of diabetes-induced mitochondrial oxidative stress before the development of a placental supply of oxygen.

Plant uncoupling mitochondrial proteins.

PubMed

Vercesi, Aníbal Eugênio; Borecký, Jiri; Maia, Ivan de Godoy; Arruda, Paulo; Cuccovia, Iolanda Midea; Chaimovich, Hernan

2006-01-01

Uncoupling proteins (UCPs) are membrane proteins that mediate purine nucleotide-sensitive free fatty acid-activated H(+) flux through the inner mitochondrial membrane. After the discovery of UCP in higher plants in 1995, it was acknowledged that these proteins are widely distributed in eukaryotic organisms. The widespread presence of UCPs in eukaryotes implies that these proteins may have functions other than thermogenesis. In this review, we describe the current knowledge of plant UCPs, including their discovery, biochemical properties, distribution, gene family, gene expression profiles, regulation of gene expression, and evolutionary aspects. Expression analyses and functional studies on the plant UCPs under normal and stressful conditions suggest that UCPs regulate energy metabolism in the cellular responses to stress through regulation of the electrochemical proton potential (Deltamu(H)+) and production of reactive oxygen species.

[Relationship among the Oxygen Concentration, Reactive Oxygen Species and the Biological Characteristics of Mouse Bone Marrow Hematopoietic Stem Cells].

PubMed

Ren, Si-Hua; He, Yu-Xin; Ma, Yi-Ran; Jin, Jing-Chun; Kang, Dan

2016-02-01

To investigate the effects of oxygen concentration and reactive oxygen species (ROS) on the biological characteristics of hematopoietic stem cells (HSC) and to analyzed the relationship among the oxygen concentration, ROS and the biological characteristics of mouse HSC through simulation of oxygen environment experienced by PB HSC during transplantation. The detection of reactive oxygen species (ROS), in vitro amplification, directional differentiation (BFU-E, CFU-GM, CFU-Mix), homing of adhesion molecules (CXCR4, CD44, VLA4, VLA5, P-selectin), migration rate, CFU-S of NOD/SCID mice irradiated with sublethal dose were performed to study the effect of oxgen concentration and reactive oxygen species on the biological characteristics of mouse BM-HSC and the relationship among them. The oxygen concentrations lower than normal oxygen concentration (especially hypoxic oxygen environment) could reduce ROS level and amplify more Lin(-) c-kit(+) Sca-1(+) BM HSC, which was more helpful to the growth of various colonies (BFU-E, CFU-GM, CFU-Mix) and to maintain the migratory ability of HSC, thus promoting CFU-S growth significantly after the transplantation of HSC in NOD/SCID mice irradiated by a sublethal dose. BM HSC exposed to oxygen environments of normal, inconstant oxygen level and strenuously thanging of oxygen concentration could result in higher level of ROS, at the same time, the above-mentioned features and functional indicators were relatively lower. The ROS levels of BM HSC in PB HSCT are closely related to the concentrations and stability of oxygen surrounding the cells. High oxygen concentration results in an high level of ROS, which is not helpful to maintain the biological characteristics of BM HSC. Before transplantation and in vitro amplification, the application of antioxidancs and constant oxygen level environments may be beneficial for transplantation of BMMSC.

Nicotine stimulates urokinase-type plasminogen activator receptor expression and cell invasiveness through mitogen-activated protein kinase and reactive oxygen species signaling in ECV304 endothelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khoi, Pham Ngoc; Park, Jung Sun; Kim, Nam Ho

Urokinase-type plasminogen activator receptor (uPAR) expression is elevated during inflammation, tissue remodeling and in many human cancers. This study investigated the effect of nicotine, a major alkaloid in tobacco, on uPAR expression and cell invasiveness in ECV304 endothelial cells. Nicotine stimulated uPAR expression in a dose-dependent manner and activated extracellular signal-regulated kinases-1/2 (Erk-1/2), c-Jun amino-terminal kinase (JNK) and p38 mitogen activated protein kinase (MAPK). Specific inhibitors of MEK-1 (PD98059) and JNK (SP600125) inhibited the nicotine-induced uPAR expression, while the p38 MAPK inhibitor SB203580 did not. Expression vectors encoding dominant negative MEK-1 (pMCL-K97M) and JNK (TAM67) also prevented nicotine-induced uPAR promotermore » activity. The intracellular hydrogen peroxide (H{sub 2}O{sub 2}) content was increased by nicotine treatment. The antioxidant N-acetylcysteine prevented nicotine-activated production of reactive oxygen species (ROS) and uPAR expression. Furthermore, exogenous H{sub 2}O{sub 2} increased uPAR mRNA expression. Deleted and site-directed mutagenesis demonstrated the involvement of the binding sites of transcription factor nuclear factor-kappaB (NF-κB) and activator protein (AP)-1 in the nicotine-induced uPAR expression. Studies with expression vectors encoding mutated NF-κB signaling molecules and AP-1 decoy confirmed that NF-κB and AP-1 were essential for the nicotine-stimulated uPAR expression. MAPK (Erk-1/2 and JNK) and ROS functioned as upstream signaling molecules in the activation of AP-1 and NF-κB, respectively. In addition, ECV304 endothelial cells treated with nicotine displayed markedly enhanced invasiveness, which was partially abrogated by uPAR neutralizing antibodies. The data indicate that nicotine induces uPAR expression via the MAPK/AP-1 and ROS/NF-κB signaling pathways and, in turn, stimulates invasiveness in human ECV304 endothelial cells. -- Highlights: ► Endothelial cells treated with nicotine displayed enhanced invasiveness. ► Nicotine induces uPAR expression and, in turn, stimulates invasiveness. ► MAPK/AP-1 and ROS/NF-κB signals are involved in nicotine-induced uPAR.« less

Inhibitory activities of soluble and bound millet seed phenolics on free radicals and reactive oxygen species.

PubMed

Chandrasekara, Anoma; Shahidi, Fereidoon

2011-01-12

Oxidative stress, caused by reactive oxygen species (ROS), is responsible for modulating several pathological conditions and aging. Soluble and bound phenolic extracts of commonly consumed millets, namely, kodo, finger (Ravi), finger (local), foxtail, proso, little, and pearl, were investigated for their phenolic content and inhibition of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and ROS, namely, hydroxyl radical, peroxyl radical, hydrogen peroxide (H(2)O(2)), hypochlorous acid (HOCl), and singlet oxygen ((1)O(2)). Inhibition of DPPH and hydroxyl radicals was detrmined using electron paramagnetic resonance (EPR) spectroscopy. The peroxyl radical inhibitory activity was measured using the oxygen radical absorbance capacity (ORAC) assay. The scavenging of H(2)O(2), HOCl, and (1)O(2) was evaluated using colorimetric methods. The results were expressed as micromoles of ferulic acid equivalents (FAE) per gram of grain on a dry weight basis. In addition, major hydroxycinnamic acids were identified and quantified using high-performance liquid chromatography (HPLC) and HPLC-mass spectrometry (MS). All millet varieties displayed effective radical and ROS inhibition activities, which generally positively correlated with phenolic contents, except for hydroxyl radical. HPLC analysis revealed the presence of ferulic and p-coumaric acids as major hydroxycinnamic acids in phenolic extract and responsible for the observed effects. Bound extracts of millet contributed 38-99% to ROS scavenging, depending on the variety and the test system employed. Hence, bound phenolics must be included in the evaluation of the antioxidant activity of millets and other cereals.

Bartter/Gitelman syndromes as a model to study systemic oxidative stress in humans.

PubMed

Maiolino, Giuseppe; Azzolini, Matteo; Rossi, Gian Paolo; Davis, Paul A; Calò, Lorenzo A

2015-11-01

Reactive oxygen species (ROS) are intermediates in reduction-oxidation reactions that begin with the addition of one electron to molecular oxygen, generating the primary ROS superoxide, which in turn interacts with other molecules to produce secondary ROS, such as hydrogen peroxide, hydroxyl radical, and peroxynitrite. ROS are continuously produced during metabolic processes and are deemed to play an important role in cardiovascular diseases, namely, myocardial hypertrophy and fibrosis and atherosclerosis, via oxidative damage of lipids, proteins, and deoxyribonucleic acid. Angiotensin II (Ang II) is a potent vasoactive agent that also exerts mitogenic, proinflammatory, and profibrotic effects through several signaling pathways, in part involving ROS, particularly superoxide and hydrogen peroxide. Moreover, Ang II stimulates NADPH oxidases, leading to higher ROS generation and oxidative stress. Bartter/Gitelman syndrome patients, despite elevated plasma renin activity, Ang II, and aldosterone levels, exhibit reduced peripheral resistance, normal/low blood pressure, and blunted pressor effect of vasoconstrictors. In addition, notwithstanding the activation of the renin-angiotensin system and the increased plasma levels of Ang II, these patients display decreased production of ROS, reduced oxidative stress, and increased antioxidant defenses. In fact, Bartter/Gitelman syndrome patients are characterized by reduced levels of p22(phox) gene expression and undetectable plasma peroxynitrite levels, while showing increased plasma antioxidant power and expression of antioxidant enzymes, such as heme oxygenase-1. In conclusion, multifarious data suggest that Bartter and Gitelman syndrome patients are a model of low oxidative stress and high antioxidant defenses. The contribution offered by the study of these syndromes in elucidating the molecular mechanisms underlying this favorable status could offer chances for new therapeutic targets in disease characterized by high levels of reactive oxygen species. Copyright © 2015 Elsevier Inc. All rights reserved.

Micro-encapsulated sensors for in vivo assessment of the oxidative stress in aquatic organisms

NASA Astrophysics Data System (ADS)

Sadovoy, Anton; Teh, Cathleen; Escobar, Marco; Meglinski, Igor; Korzh, Vladimir

2011-10-01

Oxidative stress results from an imbalance between the production and detoxification of reactive oxygen spices (ROS). ROS are natural byproducts of normal metabolism of oxygen and have important roles in cell signaling and homeostasis. Many heart related diseases like heart failure and myocardial infarction develop as a result of oxidative stress. Current treatment cannot improve the progressive decline in heart function experienced by all patients. Therefore heart failure is the cause of around 25% of all deaths in the Asia Pacific region. Thus any step taken to address the oxidative stress problem is essential for enhancing human health and improve their quality of life. Current approach is dedicated to develop micron-size oxidation stress-sensor for in-vivo measuring level of ROS in KillerRed expressing transgenic zebrafish larvae. Central to our investigation is the light-inducible heart failure animal model we developed in zebrafish that expressed KillerRed in the heart. By utilizing the photosensitizer properties of KillerRed to produce ROS upon green light illumination, heart failure can be repeatedly induced in a non-invasive manner. Importantly, the use of this biological platform permits the development of physiologically sensitive ROS sensor and identifies efficient antioxidants that improve heart contractility. The biosensor approach is based on utilizing biocompatible polyelectrolyte microcapsules as a carry of fluorescent dyes sensitive to amount of reactive oxygen spices. Microcapsule prevents dye diffusion in tissue that makes use toxic dyes possible. Microcapsule's wall is permeable for environment with size less than 500 Da. The oxidation stress-sensors are injected directly in zebrafish pericardium with further circulation along blood system. Detecting of ROS is obtained by using laser scanning microscopy by illuminating oxidation stress-sensors and detecting changing excitation signal from the fluorescent dye.

Micro-encapsulated sensors for in vivo assessment of the oxidative stress in aquatic organisms

NASA Astrophysics Data System (ADS)

Sadovoy, Anton; Teh, Cathleen; Escobar, Marco; Meglinski, Igor; Korzh, Vladimir

2012-03-01

Oxidative stress results from an imbalance between the production and detoxification of reactive oxygen spices (ROS). ROS are natural byproducts of normal metabolism of oxygen and have important roles in cell signaling and homeostasis. Many heart related diseases like heart failure and myocardial infarction develop as a result of oxidative stress. Current treatment cannot improve the progressive decline in heart function experienced by all patients. Therefore heart failure is the cause of around 25% of all deaths in the Asia Pacific region. Thus any step taken to address the oxidative stress problem is essential for enhancing human health and improve their quality of life. Current approach is dedicated to develop micron-size oxidation stress-sensor for in-vivo measuring level of ROS in KillerRed expressing transgenic zebrafish larvae. Central to our investigation is the light-inducible heart failure animal model we developed in zebrafish that expressed KillerRed in the heart. By utilizing the photosensitizer properties of KillerRed to produce ROS upon green light illumination, heart failure can be repeatedly induced in a non-invasive manner. Importantly, the use of this biological platform permits the development of physiologically sensitive ROS sensor and identifies efficient antioxidants that improve heart contractility. The biosensor approach is based on utilizing biocompatible polyelectrolyte microcapsules as a carry of fluorescent dyes sensitive to amount of reactive oxygen spices. Microcapsule prevents dye diffusion in tissue that makes use toxic dyes possible. Microcapsule's wall is permeable for environment with size less than 500 Da. The oxidation stress-sensors are injected directly in zebrafish pericardium with further circulation along blood system. Detecting of ROS is obtained by using laser scanning microscopy by illuminating oxidation stress-sensors and detecting changing excitation signal from the fluorescent dye.

Contribution of reactive oxygen species to the anticancer activity of aminoalkanol derivatives of xanthone.

PubMed

Sypniewski, Daniel; Szkaradek, Natalia; Loch, Tomasz; Waszkielewicz, Anna M; Gunia-Krzyżak, Agnieszka; Matczyńska, Daria; Sołtysik, Dagna; Marona, Henryk; Bednarek, Ilona

2018-06-01

Reactive oxygen species (ROS) are critically involved in the action of anticancer agents. In this study, we investigated the role of ROS in the anticancer mechanism of new aminoalkanol derivatives of xanthone. Most xanthones used in the study displayed significant pro-oxidant effects similar to those of gambogic acid, one of the most active anticancer xanthones. The pro-oxidant activity of our xanthones was shown both directly (by determination of ROS induction, effects on the levels of intracellular antioxidants, and expression of antioxidant enzymes) and indirectly by demonstrating that the overexpression of manganese superoxide dismutase decreases ROS-mediated cell senescence. We also observed that mitochondrial dysfunction and cellular apoptosis enhancement correlated with xanthone-induced oxidative stress. Finally, we showed that the use of the antioxidant N-acetyl-L-cysteine partly reversed these effects of aminoalkanol xanthones. Our results demonstrated that novel aminoalkanol xanthones mediated their anticancer activity primarily through ROS elevation and enhanced oxidative stress, which led to mitochondrial cell death stimulation; this mechanism was similar to the activity of gambogic acid.

Proline dehydrogenase promotes senescence through the generation of reactive oxygen species.

PubMed

Nagano, Taiki; Nakashima, Akio; Onishi, Kengo; Kawai, Kosuke; Awai, Yuto; Kinugasa, Mizuki; Iwasaki, Tetsushi; Kikkawa, Ushio; Kamada, Shinji

2017-04-15

Cellular senescence is a complex stress response characterized by permanent loss of proliferative capacity and is implicated in age-related disorders. Although the transcriptional activity of p53 (encoded by TP53 ) is known to be vital for senescence induction, the downstream effector genes critical for senescence remain unsolved. Recently, we have identified the proline dehydrogenase gene ( PRODH ) to be upregulated specifically in senescent cells in a p53-dependent manner, and the functional relevance of this to senescence is yet to be defined. Here, we conducted functional analyses to explore the relationship between PRODH and the senescence program. We found that genetic and pharmacological inhibition of PRODH suppressed senescent phenotypes induced by DNA damage. Furthermore, ectopic expression of wild-type PRODH, but not enzymatically inactive forms, induced senescence associated with the increase in reactive oxygen species (ROS) and the accumulation of DNA damage. Treatment with N-acetyl-L-cysteine, a ROS scavenger, prevented senescence induced by PRODH overexpression. These results indicate that PRODH plays a causative role in DNA damage-induced senescence through the enzymatic generation of ROS. © 2017. Published by The Company of Biologists Ltd.

Impact of Trans-Resveratrol-Sulfates and -Glucuronides on Endothelial Nitric Oxide Synthase Activity, Nitric Oxide Release and Intracellular Reactive Oxygen Species

PubMed Central

Ladurner, Angela; Schachner, Daniel; Schueller, Katharina; Pignitter, Marc; Heiss, Elke H.; Somoza, Veronika; Dirsch, Verena M.

2015-01-01

Resveratrol (3,5,4′-trihydroxy-trans-stilbene) is a polyphenolic natural product mainly present in grape skin, berries and peanuts. In the vasculature resveratrol is thought to boost endothelial function by increasing endothelial nitric oxide synthase (eNOS) expression, by enhancing eNOS activity, and by reduction of reactive oxygen species (ROS) levels. Recent studies show that dietary resveratrol is metabolized in the liver and intestine into resveratrol-sulfate and -glucuronide derivatives questioning the relevance of multiple reported mechanistic in vitro data on resveratrol. In this study, we compare side by side different physiologically relevant resveratrol metabolites (resveratrol sulfates- and -glucuronides) and their parent compound in their influence on eNOS enzyme activity, endothelial NO release, and intracellular ROS levels. In contrast to resveratrol, none of the tested resveratrol metabolites elevated eNOS enzyme activity and endothelial NO release or affected intracellular ROS levels, leaving the possibility that not tested metabolites are active and able to explain in vivo findings. PMID:25329867

Ion channels in inflammation.

PubMed

Eisenhut, Michael; Wallace, Helen

2011-04-01

Most physical illness in vertebrates involves inflammation. Inflammation causes disease by fluid shifts across cell membranes and cell layers, changes in muscle function and generation of pain. These disease processes can be explained by changes in numbers or function of ion channels. Changes in ion channels have been detected in diarrhoeal illnesses, pyelonephritis, allergy, acute lung injury and systemic inflammatory response syndromes involving septic shock. The key role played by changes in ion transport is directly evident in inflammation-induced pain. Expression or function of all major categories of ion channels like sodium, chloride, calcium, potassium, transient receptor potential, purinergic receptor and acid-sensing ion channels can be influenced by cyto- and chemokines, prostaglandins, leukotrienes, histamine, ATP, reactive oxygen species and protons released in inflammation. Key pathways in this interaction are cyclic nucleotide, phosphoinositide and mitogen-activated protein kinase-mediated signalling, direct modification by reactive oxygen species like nitric oxide, ATP or protons and disruption of the cytoskeleton. Therapeutic interventions to modulate the adverse and overlapping effects of the numerous different inflammatory mediators on each ion transport system need to target adversely affected ion transport systems directly and locally.

Specific aquaporins facilitate the diffusion of hydrogen peroxide across membranes.

PubMed

Bienert, Gerd P; Møller, Anders L B; Kristiansen, Kim A; Schulz, Alexander; Møller, Ian M; Schjoerring, Jan K; Jahn, Thomas P

2007-01-12

The metabolism of aerobic organisms continuously produces reactive oxygen species. Although potentially toxic, these compounds also function in signaling. One important feature of signaling compounds is their ability to move between different compartments, e.g. to cross membranes. Here we present evidence that aquaporins can channel hydrogen peroxide (H2O2). Twenty-four aquaporins from plants and mammals were screened in five yeast strains differing in sensitivity toward oxidative stress. Expression of human AQP8 and plant Arabidopsis TIP1;1 and TIP1;2 in yeast decreased growth and survival in the presence of H2O2. Further evidence for aquaporin-mediated H2O2 diffusion was obtained by a fluorescence assay with intact yeast cells using an intracellular reactive oxygen species-sensitive fluorescent dye. Application of silver ions (Ag+), which block aquaporin-mediated water diffusion in a fast kinetics swelling assay, also reversed both the aquaporin-dependent growth repression and the H2O2-induced fluorescence. Our results present the first molecular genetic evidence for the diffusion of H2O2 through specific members of the aquaporin family.

Naringin ameliorates diabetic nephropathy by inhibiting NADPH oxidase 4.

PubMed

Zhang, Junwei; Yang, Suxia; Li, Huicong; Chen, Fang; Shi, Jun

2017-06-05

Naringin, a naturally flavanone glycoside, has been previously demonstrated to alleviate diabetic kidney disease by inhibiting oxidative stress and inflammatory reaction. However, the underlying mechanism of naringin in diabetic nephropathy (DN) has not been fully elucidated. Here, the beneficial effect of naringin on DN in streptozotocin (STZ)-induced DN rats and high glucose (HG)-induced podocytes and its underlying mechanism were elaborated. The result revealed that naringin alleviated STZ-induced renal dysfunction and injury in DN rats, relieved STZ-induced oxidative stress in vivo and inhibited HG-induced apoptosis and reactive oxygen species level i20n vitro. More importantly, naringin inhibited NOX4 expression at mRNA and protein levels in STZ-induced DN rats and HG-induced podocytes. Loss of function indicated that NADPH oxidases 4 (NOX4) down-regulation suppressed apoptosis and reactive oxygen species level in HG-treated podocytes. Take together, this study demonstrated that naringin ameliorates diabetic nephropathy by inhibiting NOX4, contributing to a better understanding of the progression of DN. Copyright © 2017 Elsevier B.V. All rights reserved.

The angiotensin II-AT1 receptor stimulates reactive oxygen species within the cell nucleus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pendergrass, Karl D.; Gwathmey, TanYa M.; Michalek, Ryan D.

2009-06-26

We and others have reported significant expression of the Ang II Type 1 receptor (AT1R) on renal nuclei; thus, the present study assessed the functional pathways and distribution of the intracellular AT1R on isolated nuclei. Ang II (1 nM) stimulated DCF fluorescence, an intranuclear indicator of reactive oxygen species (ROS), while the AT1R antagonist losartan or the NADPH oxidase (NOX) inhibitor DPI abolished the increase in ROS. Dual labeling of nuclei with antibodies against nucleoporin 62 (Nup62) and AT1R or the NADPH oxidase isoform NOX4 revealed complete overlap of the Nup62 and AT1R (99%) by flow cytometry, while NOX4 wasmore » present on 65% of nuclei. Treatment of nuclei with a PKC agonist increased ROS while the PKC inhibitor GF109203X or PI3 kinase inhibitor LY294002 abolished Ang II stimulation of ROS. We conclude that the Ang II-AT1R-PKC axis may directly influence nuclear function within the kidney through a redox sensitive pathway.« less

Organ-Protective Effects of Red Wine Extract, Resveratrol, in Oxidative Stress-Mediated Reperfusion Injury

PubMed Central

Liu, Fu-Chao; Tsai, Hsin-I; Yu, Huang-Ping

2015-01-01

Resveratrol, a polyphenol extracted from red wine, possesses potential antioxidative and anti-inflammatory effects, including the reduction of free radicals and proinflammatory mediators overproduction, the alteration of the expression of adhesion molecules, and the inhibition of neutrophil function. A growing body of evidence indicates that resveratrol plays an important role in reducing organ damage following ischemia- and hemorrhage-induced reperfusion injury. Such protective phenomenon is reported to be implicated in decreasing the formation and reaction of reactive oxygen species and pro-nflammatory cytokines, as well as the mediation of a variety of intracellular signaling pathways, including the nitric oxide synthase, nicotinamide adenine dinucleotide phosphate oxidase, deacetylase sirtuin 1, mitogen-activated protein kinase, peroxisome proliferator-activated receptor-gamma coactivator 1 alpha, hemeoxygenase-1, and estrogen receptor-related pathways. Reperfusion injury is a complex pathophysiological process that involves multiple factors and pathways. The resveratrol is an effective reactive oxygen species scavenger that exhibits an antioxidative property. In this review, the organ-protective effects of resveratrol in oxidative stress-related reperfusion injury will be discussed. PMID:26161238

Reactive Oxygen Species and NOX Enzymes Are Emerging as Key Players in Cutaneous Wound Repair

PubMed Central

Modarressi, Ali; Pittet-Cuénod, Brigitte

2017-01-01

Our understanding of the role of oxygen in cell physiology has evolved from its long-recognized importance as an essential factor in oxidative metabolism to its recognition as an important player in cell signaling. With regard to the latter, oxygen is needed for the generation of reactive oxygen species (ROS), which regulate a number of different cellular functions including differentiation, proliferation, apoptosis, migration, and contraction. Data specifically concerning the role of ROS-dependent signaling in cutaneous wound repair are very limited, especially regarding wound contraction. In this review we provide an overview of the current literature on the role of molecular and reactive oxygen in the physiology of wound repair as well as in the pathophysiology and therapy of chronic wounds, especially under ischemic and hyperglycemic conditions. PMID:29036938

Developmentally regulated GTP-binding protein 2 depletion leads to mitochondrial dysfunction through downregulation of dynamin-related protein 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vo, Mai-Tram; Ko, Myoung Seok; Lee, Unn Hwa

Mitochondrial dynamics, including constant fusion and fission, play critical roles in maintaining mitochondrial morphology and function. Here, we report that developmentally regulated GTP-binding protein 2 (DRG2) regulates mitochondrial morphology by modulating the expression of the mitochondrial fission gene dynamin-related protein 1 (Drp1). shRNA-mediated silencing of DRG2 induced mitochondrial swelling, whereas expression of an shRNA-resistant version of DRG2 decreased mitochondrial swelling in DRG2-depleted cells. Analysis of the expression levels of genes involved in mitochondrial fusion and fission revealed that DRG2 depletion significantly decreased the level of Drp1. Overexpression of Drp1 rescued the defect in mitochondrial morphology induced by DRG2 depletion. DRG2more » depletion reduced the mitochondrial membrane potential, oxygen consumption rate (OCR), and amount of mitochondrial DNA (mtDNA), whereas it increased reactive oxygen species (ROS) production and apoptosis. Taken together, our data demonstrate that DRG2 acts as a regulator of mitochondrial fission by controlling the expression of Drp1. - Highlights: • DRG2 depletion increased mitochondrial swelling. • DRG2 depletion inhibited the expression of Drp1. • Overexpression of DRG2 or Drp1 rescued mitochondrial shape in DRG2 depleted cells. • DRG2 depletion induced mitochondrial dysfunction.« less

Isolation and Characterization of Ischemia-Derived Astrocytes (IDAs) with Ability to Transactivate Quiescent Astrocytes

PubMed Central

Villarreal, Alejandro; Rosciszewski, Gerardo; Murta, Veronica; Cadena, Vanesa; Usach, Vanina; Dodes-Traian, Martin M.; Setton-Avruj, Patricia; Barbeito, Luis H.; Ramos, Alberto J.

2016-01-01

Reactive gliosis involving activation and proliferation of astrocytes and microglia, is a widespread but largely complex and graded glial response to brain injury. Astroglial population has a previously underestimated high heterogeneity with cells differing in their morphology, gene expression profile, and response to injury. Here, we identified a subset of reactive astrocytes isolated from brain focal ischemic lesions that show several atypical characteristics. Ischemia-derived astrocytes (IDAs) were isolated from early ischemic penumbra and core. IDA did not originate from myeloid precursors, but rather from pre-existing local progenitors. Isolated IDA markedly differ from primary astrocytes, as they proliferate in vitro with high cell division rate, show increased migratory ability, have reduced replicative senescence and grow in the presence of macrophages within the limits imposed by the glial scar. Remarkably, IDA produce a conditioned medium that strongly induced activation on quiescent primary astrocytes and potentiated the neuronal death triggered by oxygen-glucose deprivation. When re-implanted into normal rat brains, eGFP-IDA migrated around the injection site and induced focal reactive gliosis. Inhibition of gamma secretases or culture on quiescent primary astrocytes monolayers facilitated IDA differentiation to astrocytes. We propose that IDA represent an undifferentiated, pro-inflammatory, highly replicative and migratory astroglial subtype emerging from the ischemic microenvironment that may contribute to the expansion of reactive gliosis. Main Points: Ischemia-derived astrocytes (IDA) were isolated from brain ischemic tissue IDA show reduced replicative senescence, increased cell division and spontaneous migration IDA potentiate death of oxygen-glucose deprived cortical neurons IDA propagate reactive gliosis on quiescent astrocytes in vitro and in vivo Inhibition of gamma secretases facilitates IDA differentiation to astrocytes PMID:27313509

Simulated digestion of Vitis vinifera seed powder: polyphenolic content and antioxidant properties.

PubMed

Janisch, Kerstin M; Olschläger, Carolin; Treutter, Dieter; Elstner, Erich F

2006-06-28

There is increasing evidence that reactive oxygen species arising from several enzymatic reactions are mediators of inflammatory events. Plant preparations have the potential for scavenging such reactive oxygen species. Flavans and procyanidins are bioavailable and stable during the process of cooking. This study used conditions that mimicked digestion of Vitis vinifera seed powder in the stomach (acidic preparation) and small intestine (neutral preparation). The flavonoids of these two preparations were released during simulated digestion and were determined with HPLC analysis. Biochemical model reactions relevant for the formation of reactive oxygen species in vivo at inflammatory sites were used to determine the antioxidant properties of the two preparations. The inhibition of the indicator reaction for the formation of reactive oxygen species represents a potential mechanism of the physiological activity of the corresponding preparation. The results of this work show clearly that the polyphenols released during the simulated digestion of the two preparations have good scavenging potential against superoxide radicals, hydroxyl radicals, and singlet oxygen. They protect low-density lipoprotein against copper-induced oxidation due to the copper-chelating properties and their chain-breaking abilities in lipid peroxidation.

COMPARATIVE ANALYSIS OF REACTIVE OXYGEN SPECIES IN HUMAN PLASMA AND BLOOD

EPA Science Inventory

Reactive oxygen species (ROS) are commonly associated with diseased states (including asthma, cardiovascular disease, cancer) infections, and exposure to various toxicants in humans. It is of interest in epidemiology studies to characterize the association of oxidative stress in...

NEW APPROACHES TO ESTIMATING INDIRECT PHOTOLYSIS RATES IN AQUATIC ENVIRONMENTS

EPA Science Inventory

Indirect photoreactions in aquatic environments are driven by reactive species, most of which are oxygen centered. Humic substances play an important role in photosensitizing the production of these reactive species, which include singlet molecular oxygen, superoxide ions, hydrog...

Measuring reactive oxygen and nitrogen species with fluorescent probes: challenges and limitations

PubMed Central

Kalyanaraman, Balaraman; Darley-Usmar, Victor; Davies, Kelvin J.A.; Dennery, Phyllis A.; Forman, Henry Jay; Grisham, Matthew B.; Mann, Giovanni E.; Moore, Kevin; Roberts, L. Jackson; Ischiropoulos, Harry

2013-01-01

The purpose of this position paper is to present a critical analysis of the challenges and limitations of the most widely used fluorescent probes for detecting and measuring reactive oxygen and nitrogen species. Where feasible, we have made recommendations for the use of alternate probes and appropriate analytical techniques that measure the specific products formed from the reactions between fluorescent probes and reactive oxygen and nitrogen species. We have proposed guidelines that will help present and future researchers with regard to the optimal use of selected fluorescent probes and interpretation of results. PMID:22027063

Benzo(a)pyrene induced cell cycle arrest and apoptosis in human choriocarcinoma cancer cells through reactive oxygen species-induced endoplasmic reticulum-stress pathway.

PubMed

Kim, Soo-Min; Lee, Hae-Miru; Hwang, Kyung-A; Choi, Kyung-Chul

2017-09-01

Cigarette smoke (CS) contains over 60 well established carcinogens. In this study, we examined the effects of benzo(a)pyrene (B(a)P), a main CS component, on the viability and apoptosis of JEG-3 and BeWo human choriocarcinoma cancer cell lines. An MTT assay confirmed that B(a)P decreased the cell viability of JEG-3 and BeWo cells in a dose-dependent manner. Additionally, Western blot (WB) assay revealed that protein expression of cyclin D and cyclin E decreased, while protein expression of p21 and p27 was increased in response to B(a)P treatment for 48 h. The changes in reactive oxygen species (ROS) levels in JEG-3 and BeWo cells exposed to B(a)P were also measured by a dichlorofluorescein diacetate (DCF-DA) assay, which revealed that ROS levels increased in response to B(a)P treatment for 48 h. WB assay also confirmed that each B(a)P treatment of JEG-3 and BeWo cells for 4 h promoted the expression of phosphorylated eukaryotic initiation factor 2 alpha protein (p-eIF2α) and C/EBP homologous protein (CHOP), which are known to be involved in ROS-mediated endoplasmic reticulum stress (ER-stress) related apoptosis. Overall, the protein expression of Bax (a pro-apoptosis marker) increased, while the expression of Bcl-xl (an anti-apoptotic marker) decreased and the number of apoptotic cells increased in response to B(a)P treatment for 48 h. Taken together, these results suggest that B(a)P has the potential to induce apoptosis of JEG-3 and BeWo human choriocarcinoma cancer cells by increasing the ROS level and simultaneously activating ER-stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mono-2-ethylhexyl phthalate induces oxidative stress responses in human placental cells in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tetz, Lauren M., E-mail: ltetz@umich.edu; Cheng, Adrienne A.; Korte, Cassandra S.

Di-2-ethylhexyl phthalate (DEHP) is an environmental contaminant commonly used as a plasticizer in polyvinyl chloride products. Exposure to DEHP has been linked to adverse pregnancy outcomes in humans including preterm birth, low birth-weight, and pregnancy loss. Although oxidative stress is linked to the pathology of adverse pregnancy outcomes, effects of DEHP metabolites, including the active metabolite, mono-2-ethylhexyl phthalate (MEHP), on oxidative stress responses in placental cells have not been previously evaluated. The objective of the current study is to identify MEHP-stimulated oxidative stress responses in human placental cells. We treated a human placental cell line, HTR-8/SVneo, with MEHP and thenmore » measured reactive oxygen species (ROS) generation using the dichlorofluorescein assay, oxidized thymine with mass-spectrometry, redox-sensitive gene expression with qRT-PCR, and apoptosis using a luminescence assay for caspase 3/7 activity. Treatment of HTR-8 cells with 180 μM MEHP increased ROS generation, oxidative DNA damage, and caspase 3/7 activity, and resulted in differential expression of redox-sensitive genes. Notably, 90 and 180 μM MEHP significantly induced mRNA expression of prostaglandin-endoperoxide synthase 2 (PTGS2), an enzyme important for synthesis of prostaglandins implicated in initiation of labor. The results from the present study are the first to demonstrate that MEHP stimulates oxidative stress responses in placental cells. Furthermore, the MEHP concentrations used were within an order of magnitude of the highest concentrations measured previously in human umbilical cord or maternal serum. The findings from the current study warrant future mechanistic studies of oxidative stress, apoptosis, and prostaglandins as molecular mediators of DEHP/MEHP-associated adverse pregnancy outcomes. - Highlights: ► MEHP increased reactive oxygen species, oxidative DNA damage, and caspase activity. ► MEHP induced expression of PTGS2, a gene important in pregnancy and parturition ► MEHP treatment resulted in differential expression of GLRX2, TXNRD1, and DHCR24.« less

Targeted Inhibition of Phosphoinositide 3-Kinase/Mammalian Target of Rapamycin Sensitizes Pancreatic Cancer Cells to Doxorubicin without Exacerbating Cardiac Toxicity.

PubMed

Durrant, David E; Das, Anindita; Dyer, Samya; Tavallai, Seyedmehrad; Dent, Paul; Kukreja, Rakesh C

2015-09-01

Pancreatic cancer has the lowest 5-year survival rate of all major cancers despite decades of effort to design and implement novel, more effective treatment options. In this study, we tested whether the dual phosphoinositide 3-kinase/mechanistic target of rapamycin inhibitor BEZ235 (BEZ) potentiates the antitumor effects of doxorubicin (DOX) against pancreatic cancer. Cotreatment of BEZ235 with DOX resulted in dose-dependent inhibition of the phosphoinositide 3-kinase/mechanistic target of rapamycin survival pathway, which corresponded with an increase in poly ADP ribose polymerase cleavage. Moreover, BEZ cotreatment significantly improved the effects of DOX toward both cell viability and cell death in part through reduced Bcl-2 expression and increased expression of the shorter, more cytotoxic forms of BIM. BEZ also facilitated intracellular accumulation of DOX, which led to enhanced DNA damage and reactive oxygen species generation. Furthermore, BEZ in combination with gemcitabine reduced MiaPaca2 cell proliferation but failed to increase reactive oxygen species generation or BIM expression, resulting in reduced necrosis and apoptosis. Treatment with BEZ and DOX in mice bearing tumor xenographs significantly repressed tumor growth as compared with BEZ, DOX, or gemcitabine. Additionally, in contrast to the enhanced expression seen in MiaPaca2 cells, BEZ and DOX cotreatment reduced BIM expression in H9C2 cardiomyocytes. Also, the Bcl-2/Bax ratio was increased, which was associated with a reduction in cell death. In vivo echocardiography showed decreased cardiac function with DOX treatment, which was not improved by combination treatment with BEZ. Thus, we propose that combining BEZ with DOX would be a better option for patients than current standard of care by providing a more effective tumor response without the associated increase in toxicity. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

Reactive oxygen species upregulate expression of muscle atrophy-associated ubiquitin ligase Cbl-b in rat L6 skeletal muscle cells.

PubMed

Uchida, Takayuki; Sakashita, Yoshihiro; Kitahata, Kanako; Yamashita, Yui; Tomida, Chisato; Kimori, Yuki; Komatsu, Akio; Hirasaka, Katsuya; Ohno, Ayako; Nakao, Reiko; Higashitani, Atsushi; Higashibata, Akira; Ishioka, Noriaki; Shimazu, Toru; Kobayashi, Takeshi; Okumura, Yuushi; Choi, Inho; Oarada, Motoko; Mills, Edward M; Teshima-Kondo, Shigetada; Takeda, Shin'ichi; Tanaka, Eiji; Tanaka, Keiji; Sokabe, Masahiro; Nikawa, Takeshi

2018-06-01

Unloading-mediated muscle atrophy is associated with increased reactive oxygen species (ROS) production. We previously demonstrated that elevated ubiquitin ligase casitas B-lineage lymphoma-b (Cbl-b) resulted in the loss of muscle volume (Nakao R, Hirasaka K, Goto J, Ishidoh K, Yamada C, Ohno A, Okumura Y, Nonaka I, Yasutomo K, Baldwin KM, Kominami E, Higashibata A, Nagano K, Tanaka K, Yasui N, Mills EM, Takeda S, Nikawa T. Mol Cell Biol 29: 4798-4811, 2009). However, the pathological role of ROS production associated with unloading-mediated muscle atrophy still remains unknown. Here, we showed that the ROS-mediated signal transduction caused by microgravity or its simulation contributes to Cbl-b expression. In L6 myotubes, the assessment of redox status revealed that oxidized glutathione was increased under microgravity conditions, and simulated microgravity caused a burst of ROS, implicating ROS as a critical upstream mediator linking to downstream atrophic signaling. ROS generation activated the ERK1/2 early-growth response protein (Egr)1/2-Cbl-b signaling pathway, an established contributing pathway to muscle volume loss. Interestingly, antioxidant treatments such as N-acetylcysteine and TEMPOL, but not catalase, blocked the clinorotation-mediated activation of ERK1/2. The increased ROS induced transcriptional activity of Egr1 and/or Egr2 to stimulate Cbl-b expression through the ERK1/2 pathway in L6 myoblasts, since treatment with Egr1/2 siRNA and an ERK1/2 inhibitor significantly suppressed clinorotation-induced Cbl-b and Egr expression, respectively. Promoter and gel mobility shift assays revealed that Cbl-b was upregulated via an Egr consensus oxidative responsive element at -110 to -60 bp of the Cbl-b promoter. Together, this indicates that under microgravity conditions, elevated ROS may be a crucial mechanotransducer in skeletal muscle cells, regulating muscle mass through Cbl-b expression activated by the ERK-Egr signaling pathway.

NADPH oxidase 4 induces cardiac fibrosis and hypertrophy through activating Akt/mTOR and NFκB signaling pathways.

PubMed

Zhao, Qingwei David; Viswanadhapalli, Suryavathi; Williams, Paul; Shi, Qian; Tan, Chunyan; Yi, Xiaolan; Bhandari, Basant; Abboud, Hanna E

2015-02-17

NADPH oxidase 4 (Nox4) has been implicated in cardiac remodeling, but its precise role in cardiac injury remains controversial. Furthermore, little is known about the downstream effector signaling pathways activated by Nox4-derived reactive oxygen species in the myocardium. We investigated the role of Nox4 and Nox4-associated signaling pathways in the development of cardiac remodeling. Cardiac-specific human Nox4 transgenic mice (c-hNox4Tg) were generated. Four groups of mice were studied: (1) control mice, littermates that are negative for hNox4 transgene but Cre positive; (2) c-hNox4 Tg mice; (3) angiotensin II (AngII)-infused control mice; and (4) c-hNox4Tg mice infused with AngII. The c-hNox4Tg mice exhibited an ≈10-fold increase in Nox4 protein expression and an 8-fold increase in the production of reactive oxygen species, and manifested cardiac interstitial fibrosis. AngII infusion to control mice increased cardiac Nox4 expression and induced fibrosis and hypertrophy. The Tg mice receiving AngII exhibited more advanced cardiac remodeling and robust elevation in Nox4 expression, indicating that AngII worsens cardiac injury, at least in part by enhancing Nox4 expression. Moreover, hNox4 transgene and AngII infusion induced the expression of cardiac fetal genes and activated the Akt-mTOR and NFκB signaling pathways. Treatment of AngII-infused c-hNox4Tg mice with GKT137831, a Nox4/Nox1 inhibitor, abolished the increase in oxidative stress, suppressed the Akt-mTOR and NFκB signaling pathways, and attenuated cardiac remodeling. Upregulation of Nox4 in the myocardium causes cardiac remodeling through activating Akt-mTOR and NFκB signaling pathways. Inhibition of Nox4 has therapeutic potential to treat cardiac remodeling. © 2015 American Heart Association, Inc.

Reactive oxygen species derived from NAD(P)H oxidase play a role on ethanol-induced hypertension and endothelial dysfunction in rat resistance arteries.

PubMed

Simplicio, Janaina A; do Vale, Gabriel T; Gonzaga, Natália A; Leite, Letícia N; Hipólito, Ulisses V; Pereira, Camila A; Tostes, Rita C; Tirapelli, Carlos R

2017-02-01

Chronic ethanol consumption is a risk factor for cardiovascular diseases. We studied whether NAD(P)H oxidase-derived reactive oxygen species (ROS) play a role in ethanol-induced hypertension, vascular dysfunction, and protein expression in resistance arteries. Male Wistar rats were treated with ethanol (20 % v/v) for 6 weeks. Ethanol treatment increased blood pressure and decreased acetylcholine-induced relaxation in the rat mesenteric arterial bed (MAB). These responses were attenuated by apocynin (30 mg/kg/day; p.o. gavage). Ethanol consumption increased superoxide anion (O 2 - ) generation and decreased nitrate/nitrite (NO x ) concentration in the rat MAB and apocynin prevented these responses. Conversely, ethanol did not affect the concentration of hydrogen peroxide (H 2 O 2 ) and reduced glutathione (GSH) or the activity of superoxide dismutase (SOD) and catalase (CAT) in the rat MAB. Ethanol increased interleukin (IL)-10 levels in the rat MAB but did not affect the levels of tumor necrosis factor (TNF)-α, IL-6, or IL-1β. Ethanol increased the expression of Nox2 and the phosphorylation of SAPK/JNK, but reduced eNOS expression in the rat MAB. Apocynin prevented these responses. However, ethanol treatment did not affect the expression of Nox1, Nox4, p38MAPK, ERK1/2, or SAPK/JNK in the rat MAB. Ethanol increased plasma levels of TBARS, TNF-α, IL-6, IL-1β, and IL-10, whereas it decreased NO x levels. The major finding of our study is that NAD(P)H oxidase-derived ROS play a role on ethanol-induced hypertension and endothelial dysfunction in resistance arteries. Moreover, ethanol consumption affects the expression and phosphorylation of proteins that regulate vascular function and NAD(P)H oxidase-derived ROS play a role in such responses.

Epithelial–mesenchymal transition during oncogenic transformation induced by hexavalent chromium involves reactive oxygen species-dependent mechanism in lung epithelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ding, Song-Ze, E-mail: dingsongze@hotmail.com; Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536; Yang, Yu-Xiu

2013-05-15

Hexavalent chromium [Cr(VI)] is an important human carcinogen associated with pulmonary diseases and lung cancer. Exposure to Cr(VI) induces DNA damage, cell morphological change and malignant transformation in human lung epithelial cells. Despite extensive studies, the molecular mechanisms remain elusive, it is also not known if Cr(VI)-induced transformation might accompany with invasive properties to facilitate metastasis. We aimed to study Cr(VI)-induced epithelial–mesenchymal transition (EMT) and invasion during oncogenic transformation in lung epithelial cells. The results showed that Cr(VI) at low doses represses E-cadherin mRNA and protein expression, enhances mesenchymal marker vimentin expression and transforms the epithelial cell into fibroblastoid morphology.more » Cr(VI) also increases cell invasion and promotes colony formation. Further studies indicated that Cr(VI) uses multiple mechanisms to repress E-cadherin expression, including activation of E-cadherin repressors such as Slug, ZEB1, KLF8 and enhancement the binding of HDAC1 in E-cadherin gene promoter, but DNA methylation is not responsible for the loss of E-cadherin. Catalase reduces Cr(VI)-induced E-cadherin and vimentin protein expression, attenuates cell invasion in matrigel and colony formation on soft agar. These results demonstrate that exposure to a common human carcinogen, Cr(VI), induces EMT and invasion during oncogenic transformation in lung epithelial cells and implicate in cancer metastasis and prevention. - Graphical abstract: Epithelial–mesenchymal transition during oncogenic transformation induced by hexavalent chromium involves reactive oxygen species-dependent mechanisms in lung epithelial cells. - Highlights: • We study if Cr(VI) might induce EMT and invasion in epithelial cells. • Cr(VI) induces EMT by altering E-cadherin and vimentin expression. • It also increases cell invasion and promotes oncogenic transformation. • Catalase reduces Cr(VI)-induced EMT, invasion and transformation.« less

Oxidized low-density lipoprotein and β-glycerophosphate synergistically induce endothelial progenitor cell ossification

PubMed Central

Liu, Li; Liu, Zhi-zhong; Chen, Hui; Zhang, Guo-jun; Kong, Yu-hua; Kang, Xi-xiong

2011-01-01

Aim: To investigate the ability of ox-LDL to induce ossification of endothelial progenitor cells (EPCs) in vitro and explored whether oxidative stress, especially hypoxia inducible factor-1α (HIF-1α) and reactive oxygen species (ROS), participate in the ossific process. Methods: Rat bone marrow-derived endothelial progenitor cells (BMEPCs) were cultured in endothelial growth medium supplemented with VEGF (40 ng/mL) and bFGF (10 ng/mL). The cells were treated with oxidized low-density lipoprotein (ox-LDL, 5 μg/mL) and/or β-glycerophosphate (β-GP, 10 mmol/L). Calcium content and Von Kossa staining were used as the measures of calcium deposition. Ossific gene expression was determined using RT-PCR. The expression of osteocalcin (OCN) was detected with immunofluorescence. Alkaline phosphatase (ALP) activity was analyzed using colorimetric assay. Intercellular reactive oxygen species (ROS) were measured with flow cytometry. Results: BMEPCs exhibited a spindle-like shape. The percentage of cells that expressed the cell markers of EPCs CD34, CD133 and kinase insert domain-containing receptor (KDR) were 46.2%±5.8%, 23.5%±4.0% and 74.3%±8.8%, respectively. Among the total cells, 78.3%±4.2% were stained with endothelial-specific fluorescence. Treatment of BMEPCs with ox-LDL significantly promoted calcium deposition, which was further significantly enhanced by co-treatment with β-GP. The same treatments significantly increased the gene expression of core-binding factor a-1 (cbfa-1) and OCN, while decreased the gene expression of osteoprotegerin (OPG). The treatments also significantly enhanced the activity of ALP, but did not affect the number of OCN+ cells. Furthermore, the treatments significantly increased ROS and activated the hypoxia inducible factor-1α (HIF-1α). In all these effects, ox-LDL acted synergistically with β-GP. Conclusion: Ox-LDL and β-GP synergistically induce ossification of BMEPCs, in which an oxidizing mechanism is involved. PMID:22036865

Oxidized low-density lipoprotein and β-glycerophosphate synergistically induce endothelial progenitor cell ossification.

PubMed

Liu, Li; Liu, Zhi-zhong; Chen, Hui; Zhang, Guo-jun; Kong, Yu-hua; Kang, Xi-xiong

2011-12-01

To investigate the ability of ox-LDL to induce ossification of endothelial progenitor cells (EPCs) in vitro and explored whether oxidative stress, especially hypoxia inducible factor-1α (HIF-1α) and reactive oxygen species (ROS), participate in the ossific process. Rat bone marrow-derived endothelial progenitor cells (BMEPCs) were cultured in endothelial growth medium supplemented with VEGF (40 ng/mL) and bFGF (10 ng/mL). The cells were treated with oxidized low-density lipoprotein (ox-LDL, 5 μg/mL) and/or β-glycerophosphate (β-GP, 10 mmol/L). Calcium content and Von Kossa staining were used as the measures of calcium deposition. Ossific gene expression was determined using RT-PCR. The expression of osteocalcin (OCN) was detected with immunofluorescence. Alkaline phosphatase (ALP) activity was analyzed using colorimetric assay. Intercellular reactive oxygen species (ROS) were measured with flow cytometry. BMEPCs exhibited a spindle-like shape. The percentage of cells that expressed the cell markers of EPCs CD34, CD133 and kinase insert domain-containing receptor (KDR) were 46.2%±5.8%, 23.5%±4.0% and 74.3%±8.8%, respectively. Among the total cells, 78.3%±4.2% were stained with endothelial-specific fluorescence. Treatment of BMEPCs with ox-LDL significantly promoted calcium deposition, which was further significantly enhanced by co-treatment with β-GP. The same treatments significantly increased the gene expression of core-binding factor a-1 (cbfa-1) and OCN, while decreased the gene expression of osteoprotegerin (OPG). The treatments also significantly enhanced the activity of ALP, but did not affect the number of OCN(+) cells. Furthermore, the treatments significantly increased ROS and activated the hypoxia inducible factor-1α (HIF-1α). In all these effects, ox-LDL acted synergistically with β-GP. Ox-LDL and β-GP synergistically induce ossification of BMEPCs, in which an oxidizing mechanism is involved.

Mitochondrial stress controls the radiosensitivity of the oxygen effect: Implications for radiotherapy.

PubMed

Richardson, Richard B; Harper, Mary-Ellen

2016-04-19

It has been more than 60 years since the discovery of the oxygen effect that empirically demonstrates the direct association between cell radiosensitivity and oxygen tension, important parameters in radiotherapy. Yet the mechanisms underlying this principal tenet of radiobiology are poorly understood. Better understanding of the oxygen effect may explain difficulty in eliminating hypoxic tumor cells, a major cause of regrowth after therapy. Our analysis utilizes the Howard-Flanders and Alper formula, which describes the relationship of radiosensitivity with oxygen tension. Here, we assign and qualitatively assess the relative contributions of two important mechanisms. The first mechanism involves the emission of reactive oxygen species from the mitochondrial electron transport chain, which increases with oxygen tension. The second mechanism is related to an energy and repair deficit, which increases with hypoxia. Following a radiation exposure, the uncoupling of the oxidative phosphorylation system (proton leak) in mitochondria lowers the emission of reactive oxygen species which has implications for fractionated radiotherapy, particularly of hypoxic tumors. Our analysis shows that, in oxygenated tumor and normal cells, mitochondria, rather than the nucleus, are the primary loci of radiotherapy effects, especially for low linear energy transfer radiation. Therefore, the oxygen effect can be explained by radiation-induced effects in mitochondria that generate reactive oxygen species, which in turn indirectly target nuclear DNA.

The Complex Transcriptional Response of Acaryochloris marina to Different Oxygen Levels.

PubMed

Hernández-Prieto, Miguel A; Lin, Yuankui; Chen, Min

2017-02-09

Ancient oxygenic photosynthetic prokaryotes produced oxygen as a waste product, but existed for a long time under an oxygen-free (anoxic) atmosphere, before an oxic atmosphere emerged. The change in oxygen levels in the atmosphere influenced the chemistry and structure of many enzymes that contained prosthetic groups that were inactivated by oxygen. In the genome of Acaryochloris marina , multiple gene copies exist for proteins that are normally encoded by a single gene copy in other cyanobacteria. Using high throughput RNA sequencing to profile transcriptome responses from cells grown under microoxic and hyperoxic conditions, we detected 8446 transcripts out of the 8462 annotated genes in the Cyanobase database. Two-thirds of the 50 most abundant transcripts are key proteins in photosynthesis. Microoxic conditions negatively affected the levels of expression of genes encoding photosynthetic complexes, with the exception of some subunits. In addition to the known regulation of the multiple copies of psbA , we detected a similar transcriptional pattern for psbJ and psbU , which might play a key role in the altered components of photosystem II. Furthermore, regulation of genes encoding proteins important for reactive oxygen species-scavenging is discussed at genome level, including, for the first time, specific small RNAs having possible regulatory roles under varying oxygen levels. Copyright © 2017 Hernandez-Prieto et al.

The Complex Transcriptional Response of Acaryochloris marina to Different Oxygen Levels

PubMed Central

Hernández-Prieto, Miguel A.; Lin, Yuankui; Chen, Min

2016-01-01

Ancient oxygenic photosynthetic prokaryotes produced oxygen as a waste product, but existed for a long time under an oxygen-free (anoxic) atmosphere, before an oxic atmosphere emerged. The change in oxygen levels in the atmosphere influenced the chemistry and structure of many enzymes that contained prosthetic groups that were inactivated by oxygen. In the genome of Acaryochloris marina, multiple gene copies exist for proteins that are normally encoded by a single gene copy in other cyanobacteria. Using high throughput RNA sequencing to profile transcriptome responses from cells grown under microoxic and hyperoxic conditions, we detected 8446 transcripts out of the 8462 annotated genes in the Cyanobase database. Two-thirds of the 50 most abundant transcripts are key proteins in photosynthesis. Microoxic conditions negatively affected the levels of expression of genes encoding photosynthetic complexes, with the exception of some subunits. In addition to the known regulation of the multiple copies of psbA, we detected a similar transcriptional pattern for psbJ and psbU, which might play a key role in the altered components of photosystem II. Furthermore, regulation of genes encoding proteins important for reactive oxygen species-scavenging is discussed at genome level, including, for the first time, specific small RNAs having possible regulatory roles under varying oxygen levels. PMID:27974439

Role of Hydroalcoholic Extract of Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Agaricomycetes), in Facilitating Cellular Acclimatization in a Low-Oxygen Microenvironment.

PubMed

Koganti, Praveen; Tulsawani, Rajkumar; Sharma, Purva; Sharma, Manish; Arora, Shivani; Misra, Kshipra

2018-01-01

Ganoderma lucidum is known to exert many health benefits including effects to improve oxygen utilization. Therefore, this study was designed to evaluate the role of a hydroalcoholic G. lucidum extract in providing tolerance to HT22 cells grown under hypoxic conditions. HT22 cells were exposed to 0.5% O2 in the presence or absence of the extract for 24 hours. At the end of the exposure period, we performed cell viability assays, cell cycle analysis, and biochemical and protein expression studies. The extract-treated cells revealed less cell death, minimized caspase 3 and reactive oxygen species levels, and relieved G0/G1 cell cycle arrest compared with hypoxic cells cultured without the extract. Further, extract-treated cells showed improved expression of Nrf2, heme oxygenase 1, and metallothionein and stabilized levels of hypoxia-inducible factor 1α. Moreover, lower levels of nuclear factor-κB and tumor necrosis factor a were evident in extract-treated cells. Overall, the G. lucidum extract reduced hypoxia-induced cell death and augmented transcription factors (HIF-1α and Nrf2), conferring tolerance to hypoxia.

Genotype differences in anxiety and fear learning and memory of WT and ApoE4 mice associated with enhanced generation of hippocampal reactive oxygen species.

PubMed

Villasana, Laura E; Weber, Sydney; Akinyeke, Tunde; Raber, Jacob

2016-09-01

Apolipoprotein E (apoE), involved in cholesterol and lipid metabolism, also influences cognitive function and injury repair. In humans, apoE is expressed in three isoforms. E4 is a risk factor for age-related cognitive decline and Alzheimer's disease, particularly in women. E4 might also be a risk factor for developing behavioral and cognitive changes following (56) Fe irradiation, a component of the space environment astronauts are exposed to during missions. These changes might be related to enhanced generation of reactive oxygen species (ROS). In this study, we compared the behavioral and cognitive performance of sham-irradiated and irradiated wild-type (WT) mice and mice expressing the human E3 or E4 isoforms, and assessed the generation of ROS in hippocampal slices from these mice. E4 mice had greater anxiety-like and conditioned fear behaviors than WT mice, and these genotype differences were associated with greater levels of ROS in E4 than WT mice. The greater generation of ROS in the hippocampus of E4 than WT mice might contribute to their higher anxiety levels and enhanced fear conditioning. In E4, but not WT, mice, phorbol-12-myristate-13-acetate-treated hippocampal slices showed more dihydroxy ethidium oxidation in sham-irradiated than irradiated mice and hippocampal heme oxygenase-1 levels were higher in irradiated than sham-irradiated E4 mice. Mice with apolipoprotein E4 (E4), a risk factor for Alzheimer's disease, have greater anxiety-like and conditioned fear behaviors than wild-type (WT) mice. Generation of reactive oxygen species (ROS, in red) 3 months following (56) Fe irradiation, a component of the space environment astronauts are exposed to, is more pronounced in the hippocampus of E4 than WT mice. In E4, but not WT, mice, hippocampal levels of the oxidative stress-relevant marker heme oxygenase-1 are higher in irradiated than sham-irradiated E4 mice. © 2016 International Society for Neurochemistry.

Beta-mangostin from Cratoxylum arborescens activates the intrinsic apoptosis pathway through reactive oxygen species with downregulation of the HSP70 gene in the HL60 cells associated with a G0/G1 cell-cycle arrest.

PubMed

Omer, Fatima Abdelmutaal Ahmed; Hashim, Najihah Binti Mohd; Ibrahim, Mohamed Yousif; Dehghan, Firouzeh; Yahayu, Maizatulakmal; Karimian, Hamed; Salim, Landa Zeenelabdin Ali; Mohan, Syam

2017-11-01

Xanthones are phytochemical compounds found in a number of fruits and vegetables. Characteristically, they are noted to be made of diverse properties based on their biological, biochemical, and pharmacological actions. Accordingly, the apoptosis mechanisms induced by beta-mangostin, a xanthone compound isolated from Cratoxylum arborescens in the human promyelocytic leukemia cell line (HL60) in vitro, were examined in this study. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was done to estimate the cytotoxicity effect of β-mangostin on the HL60 cell line. Acridine orange/propidium iodide and Hoechst 33342 dyes and Annexin V tests were conducted to detect the apoptosis features. Caspase-3 and caspase-9 activities; reactive oxygen species; real-time polymerase chain reaction for Bcl-2, Bax, caspase-3, and caspase-9 Hsp70 genes; and western blot for p53, cytochrome c, and pro- and cleavage-caspase-3 and caspase-9 were assessed to examine the apoptosis mechanism. Cell-cycle analysis conducted revealed that β-mangostin inhibited the growth of HL60 at 58 µM in 24 h. The administration of β-mangostin with HL60 caused cell morphological changes related to apoptosis which increased the number of early and late apoptotic cells. The β-mangostin-catalyzed apoptosis action through caspase-3, caspase-7, and caspase-9 activation overproduced reactive oxygen species which downregulated the expression of antiapoptotic genes Bcl-2 and HSP70. Conversely, the expression of the apoptotic genes Bax, caspase-3, and caspase-9 were upregulated. Meanwhile, at the protein level, β-mangostin activated the formation of cleaved caspase-3 and caspase-9 and also upregulated the p53. β-mangostin arrested the cell cycle at the G 0 /G 1 phase. Overall, the results for β-mangostin showed an antiproliferative effect in HL60 via stopping the cell cycle at the G 0 /G 1 phase and prompted the intrinsic apoptosis pathway.

Heme oxygenase is not involved in the anti-proliferative effects of statins on pancreatic cancer cells.

PubMed

Vanova, K; Boukalova, S; Gbelcova, H; Muchova, L; Neuzil, J; Gurlich, R; Ruml, T; Vitek, L

2016-05-12

Pancreatic cancer is recognized as one of the most fatal tumors due to its aggressiveness and resistance to therapy. Statins were previously shown to inhibit the proliferation of cancer cells via various signaling pathways. In healthy tissues, statins activate the heme oxygenase pathway, nevertheless the role of heme oxygenase in pancreatic cancer is still controversial. The aim of this study was to evaluate, whether anti-proliferative effects of statins in pancreatic cancer cells are mediated via the heme oxygenase pathway. In vitro effects of various statins and hemin, a heme oxygenase inducer, on cell proliferation were evaluated in PA-TU-8902, MiaPaCa-2 and BxPC-3 human pancreatic cancer cell lines. The effect of statins on heme oxygenase activity was assessed and heme oxygenase-silenced cells were used for pancreatic cancer cell proliferation studies. Cell death rate and reactive oxygen species production were measured in PA-TU-8902 cells, followed by evaluation of the effect of cerivastatin on GFP-K-Ras trafficking and expression of markers of invasiveness, osteopontin (SPP1) and SOX2. While simvastatin and cerivastatin displayed major anti-proliferative properties in all cell lines tested, pravastatin did not affect the cell growth at all. Strong anti-proliferative effect was observed also for hemin. Co-treatment of cerivastatin and hemin increased anti-proliferative potential of these agents, via increased production of reactive oxygen species and cell death compared to individual treatment. Heme oxygenase silencing did not prevent pancreatic cancer cells from the tumor-suppressive effect of cerivastatin or hemin. Cerivastatin, but not pravastatin, protected Ras protein from trafficking to the cell membrane and significantly reduced expressions of SPP1 (p < 0.05) and SOX2 (p < 0.01). Anti-proliferative effects of statins and hemin on human pancreatic cancer cell lines do not seem to be related to the heme oxygenase pathway. While hemin triggers reactive oxygen species-induced cell death, cerivastatin targets Ras protein trafficking and affects markers of invasiveness.

Effects of Laser Printer–Emitted Engineered Nanoparticles on Cytotoxicity, Chemokine Expression, Reactive Oxygen Species, DNA Methylation, and DNA Damage: A Comprehensive in Vitro Analysis in Human Small Airway Epithelial Cells, Macrophages, and Lymphoblasts

PubMed Central

Pirela, Sandra V.; Miousse, Isabelle R.; Lu, Xiaoyan; Castranova, Vincent; Thomas, Treye; Qian, Yong; Bello, Dhimiter; Kobzik, Lester; Koturbash, Igor; Demokritou, Philip

2015-01-01

Background Engineered nanomaterials (ENMs) incorporated into toner formulations of printing equipment become airborne during consumer use. Although information on the complex physicochemical and toxicological properties of both toner powders and printer-emitted particles (PEPs) continues to grow, most toxicological studies have not used the actual PEPs but rather have primarily used raw toner powders, which are not representative of current exposures experienced at the consumer level during printing. Objectives We assessed the biological responses of a panel of human cell lines to PEPs. Methods Three physiologically relevant cell lines—small airway epithelial cells (SAECs), macrophages (THP-1 cells), and lymphoblasts (TK6 cells)—were exposed to PEPs at a wide range of doses (0.5–100 μg/mL) corresponding to human inhalation exposure durations at the consumer level of 8 hr or more. Following treatment, toxicological parameters reflecting distinct mechanisms were evaluated. Results PEPs caused significant membrane integrity damage, an increase in reactive oxygen species (ROS) production, and an increase in pro-inflammatory cytokine release in different cell lines at doses equivalent to exposure durations from 7.8 to 1,500 hr. Furthermore, there were differences in methylation patterns that, although not statistically significant, demonstrate the potential effects of PEPs on the overall epigenome following exposure. Conclusions The in vitro findings obtained in this study suggest that laser printer–emitted engineered nanoparticles may be deleterious to lung cells and provide preliminary evidence of epigenetic modifications that might translate to pulmonary disorders. Citation Pirela SV, Miousse IR, Lu X, Castranova V, Thomas T, Qian Y, Bello D, Kobzik L, Koturbash I, Demokritou P. 2016. Effects of laser printer–emitted engineered nanoparticles on cytotoxicity, chemokine expression, reactive oxygen species, DNA methylation, and DNA damage: a comprehensive in vitro analysis in human small airway epithelial cells, macrophages, and lymphoblasts. Environ Health Perspect 124:210–219; http://dx.doi.org/10.1289/ehp.1409582 PMID:26080392

Regulatory Mechanisms Involved in the Expression of Brain-Derived Neurotrophic Factor and Glial Cell Line-Derived Neurotrophic Factor

DTIC Science & Technology

1996-03-01

neurotoxic dopamine analog that is taken up by nigral dopaminergic cells where it is metabolized to highly reactive oxygen free radicals that cause ...brain regions is elevated after other types of brain insults, including ischemia and hypoglycemia (see Lindvall et al. 1994 for review). Lindvall et a1...with kainic acid were also reported. These investigators also reported significant increases in BDNF mRNA levels in cultures of neonatal astrocytes

BIOMONITORING OF REACTIVE OXYGEN SPECIES IN BIOLOGICAL FLUIDS

EPA Science Inventory

Elevated levels of reactive oxygen species (ROS) are associated with several disease processes in humans, including cancer, asthma, diabetes, and cardiac disease. We have explored whether ROS can be measured directly in human fluids, and their value as a biomarker of exposure an...

Investigation of the reactivity of organic materials in liquid oxygen

NASA Technical Reports Server (NTRS)

Chamberlain, D.; Irwin, K.; Kirshen, N.; Mill, T.; Stringham, R.

1970-01-01

Measurements of impact-ignition sensitivity and studies of the relative reactivity of t-butoxy and t-butyl peroxy radicals toward a variety of organic compounds reveal improved methods of selection of materials for safe use in a liquid oxygen environment.

Solar light-induced production of reactive oxygen species by single walled carbon nanotubes in water

EPA Science Inventory

Photosensitizing processes of engineered nanomaterials (ENMs) which include photo-induced production of reactive oxygen species (ROS) convert light energy into oxidizing chemical energy that mediates transformations of nanomaterials. The oxidative stress associated with ROS may p...

Eros is a novel transmembrane protein that controls the phagocyte respiratory burst and is essential for innate immunity

PubMed Central

Thomas, David C.; Clare, Simon; Sowerby, John M.; Juss, Jatinder K.; Goulding, David A.; van der Weyden, Louise; Prakash, Ananth; Harcourt, Katherine; Mukhopadhyay, Subhankar; Antrobus, Robin; Bateman, Alex

2017-01-01

The phagocyte respiratory burst is crucial for innate immunity. The transfer of electrons to oxygen is mediated by a membrane-bound heterodimer, comprising gp91phox and p22phox subunits. Deficiency of either subunit leads to severe immunodeficiency. We describe Eros (essential for reactive oxygen species), a protein encoded by the previously undefined mouse gene bc017643, and show that it is essential for host defense via the phagocyte NAPDH oxidase. Eros is required for expression of the NADPH oxidase components, gp91phox and p22phox. Consequently, Eros-deficient mice quickly succumb to infection. Eros also contributes to the formation of neutrophil extracellular traps (NETS) and impacts on the immune response to melanoma metastases. Eros is an ortholog of the plant protein Ycf4, which is necessary for expression of proteins of the photosynthetic photosystem 1 complex, itself also an NADPH oxio-reductase. We thus describe the key role of the previously uncharacterized protein Eros in host defense. PMID:28351984

Insulin Reverses D-Glucose–Increased Nitric Oxide and Reactive Oxygen Species Generation in Human Umbilical Vein Endothelial Cells

PubMed Central

González, Marcelo; Rojas, Susana; Avila, Pía; Cabrera, Lissette; Villalobos, Roberto; Palma, Carlos; Aguayo, Claudio; Peña, Eduardo; Gallardo, Victoria; Guzmán-Gutiérrez, Enrique; Sáez, Tamara; Salsoso, Rocío; Sanhueza, Carlos; Pardo, Fabián; Leiva, Andrea; Sobrevia, Luis

2015-01-01

Vascular tone is controlled by the L-arginine/nitric oxide (NO) pathway, and NO bioavailability is strongly affected by hyperglycaemia-induced oxidative stress. Insulin leads to high expression and activity of human cationic amino acid transporter 1 (hCAT-1), NO synthesis and vasodilation; thus, a protective role of insulin on high D-glucose–alterations in endothelial function is likely. Vascular reactivity to U46619 (thromboxane A2 mimetic) and calcitonin gene related peptide (CGRP) was measured in KCl preconstricted human umbilical vein rings (wire myography) incubated in normal (5 mmol/L) or high (25 mmol/L) D-glucose. hCAT-1, endothelial NO synthase (eNOS), 42 and 44 kDa mitogen-activated protein kinases (p42/44mapk), protein kinase B/Akt (Akt) expression and activity were determined by western blotting and qRT-PCR, tetrahydrobiopterin (BH4) level was determined by HPLC, and L-arginine transport (0–1000 μmol/L) was measured in response to 5–25 mmol/L D-glucose (0–36 hours) in passage 2 human umbilical vein endothelial cells (HUVECs). Assays were in the absence or presence of insulin and/or apocynin (nicotinamide adenine dinucleotide phosphate-oxidase [NADPH oxidase] inhibitor), tempol or Mn(III)TMPyP (SOD mimetics). High D-glucose increased hCAT-1 expression and activity, which was biphasic (peaks: 6 and 24 hours of incubation). High D-glucose–increased maximal transport velocity was blocked by insulin and correlated with lower hCAT-1 expression and SLC7A1 gene promoter activity. High D-glucose–increased transport parallels higher reactive oxygen species (ROS) and superoxide anion (O2 •–) generation, and increased U46619-contraction and reduced CGRP-dilation of vein rings. Insulin and apocynin attenuate ROS and O2 •– generation, and restored vascular reactivity to U46619 and CGRP. Insulin, but not apocynin or tempol reversed high D-glucose–increased NO synthesis; however, tempol and Mn(III)TMPyP reversed the high D-glucose–reduced BH4 level. Insulin and tempol blocked the high D-glucose–increased p42/44mapk phosphorylation. Vascular dysfunction caused by high D-glucose is likely attenuated by insulin through the L-arginine/NO and O2 •–/NADPH oxidase pathways. These findings are of interest for better understanding vascular dysfunction in states of foetal insulin resistance and hyperglycaemia. PMID:25875935

Exposure to ultrafine particles, intracellular production of reactive oxygen species in leukocytes and altered levels of endothelial progenitor cells.

PubMed

Jantzen, Kim; Møller, Peter; Karottki, Dorina Gabriela; Olsen, Yulia; Bekö, Gabriel; Clausen, Geo; Hersoug, Lars-Georg; Loft, Steffen

2016-06-01

Exposure to particles in the fine and ultrafine size range has been linked to induction of low-grade systemic inflammation, oxidative stress and development of cardiovascular diseases. Declining levels of endothelial progenitor cells within systemic circulation have likewise been linked to progression of cardiovascular diseases. The objective was to determine if exposure to fine and ultrafine particles from indoor and outdoor sources, assessed by personal and residential indoor monitoring, is associated with altered levels of endothelial progenitor cells, and whether such effects are related to leukocyte-mediated oxidative stress. The study utilized a cross sectional design performed in 58 study participants from a larger cohort. Levels of circulating endothelial progenitor cells, defined as either late (CD34(+)KDR(+) cells) or early (CD34(+)CD133(+)KDR(+) cells) subsets were measured using polychromatic flow cytometry. We additionally measured production of reactive oxygen species in leukocyte subsets (lymphocytes, monocytes and granulocytes) by flow cytometry using intracellular 2',7'-dichlorofluoroscein. The measurements encompassed both basal levels of reactive oxygen species production and capacity for reactive oxygen species production for each leukocyte subset. We found that the late endothelial progenitor subset was negatively associated with levels of ultrafine particles measured within the participant residences and with reactive oxygen species production capacity in lymphocytes. Additionally, the early endothelial progenitor cell levels were positively associated with a personalised measure of ultrafine particle exposure and negatively associated with both basal and capacity for reactive oxygen species production in lymphocytes and granulocytes, respectively. Our results indicate that exposure to fine and ultrafine particles derived from indoor sources may have adverse effects on human vascular health. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

A study of the free radical scavenging effects of Piper betle leaf extract in patients with vitiligo.

PubMed

Mitra, Sneha; Pati, Ayan Kumar; Manna, Alak; Ghosh, Arghyaprasun; Sen, Sumit; Chatterjee, Suparna; Chatterjee, Mitali

2017-01-01

Vitiligo is an idiopathic skin disease manifested by depigmented macules. It is characterised by melanocyte destruction, and redox imbalance is proposed to play a contributory role. The aim of this study was to analyze the effects of an ethanolic extract of Piper betle leaves on the generation of reactive oxygen species in erythrocytes sourced from vitiligo patients. The effect of Piper betle on the generation of reactive oxygen species in erythrocytes was measured by flow cytometry in patients with active and stable vitiligo versus healthy controls, using 5-(and-6)-chloromethyl-2'-7'-dichlorodihydrofluorescein diacetate. The generation of reactive oxygen species in erythrocytes was higher in patients with vitiligo (n = 23) compared to healthy controls (n = 18). The geometrical mean fluorescence channel was 23.05 ± 2.11 in patients versus 17.77 ± 1.79 in controls, P = 0.039. The levels of reactive oxygen species were higher in patients with active vitiligo. Treatment of erythrocytes with Piper betle in concentrations of 0.5 and 1.0 μg/ml significantly decreased the baseline levels of reactive oxygen species by 31.7% in healthy controls, and 47.6% and 44.3% in patients with active vitiligo, respectively. Piper betle effectively scavenged hydrogen peroxide, which was evident by a decrease in the geometrical mean fluorescence channel by 52.4% and 62.9% in healthy controls, and 45.0% and 57.0% in patients with active vitiligo. The study had a small sample size. Future studies should focus on evaluation of the antioxidant role of Piper betle at the lesional site. This pilot study indicates that patients with active vitiligo demonstrate enhanced generation of reactive oxygen species in erythrocytes, which was significantly reduced following ex vivo treatment with Piper betle.

Effect of single oral dose of azithromycin, clarithromycin, and roxithromycin on polymorphonuclear leukocyte function assessed ex vivo by flow cytometry.

PubMed Central

Wenisch, C; Parschalk, B; Zedtwitz-Liebenstein, K; Weihs, A; el Menyawi, I; Graninger, W

1996-01-01

Azithromycin was given as a single oral dose (20 mg/kg of body weight) to 12 volunteers in a crossover study with roxithromycin (8 to 12 mg/kg) and clarithromycin (8 to 12 mg/kg). Flow cytometry was used to study the phagocytic functions and the release of reactive oxygen products following phagocytosis by neutrophil granulocytes prior to administration of the three drugs, 16 h after azithromycin administration, and 3 h after clarithromycin and roxithromycin administration. Phagocytic capacity was assessed by measuring the uptake of fluorescein isothiocyanate-labeled bacteria. Reactive oxygen generation after phagocytosis of unlabeled bacteria was estimated by the amount of dihydrorhodamine 123 converted to rhodamine 123 intracellularly. Azithromycin resulted in decreased capacities of the cells to phagocytize Escherichia coli (median [range], 62% [27 to 91%] of the control values; P < 0.01) and generate reactive oxygen products (75% [34 to 26%] of the control values; P < 0.01). Clarithromycin resulted in reduced phagocytosis (82% [75 to 98%] of control values; P < 0.01) but did not alter reactive oxygen production (84% [63 to 113%] of the control values; P > 0.05). Roxithromycin treatment did not affect granulocyte phagocytosis (92% [62 to 118%] of the control values; P > 0.05) or reactive oxygen production (94% [66 to 128%] of the control value; P > 0.05). No relation between intra- and/or extracellular concentrations of azithromycin and/or roxithromycin and the polymorphonuclear phagocyte function and/or reactive oxygen production existed (P > 0.05 for all comparisons). These results demonstrate that the accumulation of macrolides in neutrophils can suppress the response of phagocytic cells to bacterial pathogens after a therapeutic dose. PMID:8878577

Bis is Induced by Oxidative Stress via Activation of HSF1

PubMed Central

Yoo, Hyung Jae; Im, Chang-Nim; Youn, Dong-Ye; Yun, Hye Hyeon

2014-01-01

The Bis protein is known to be involved in a variety of cellular processes including apoptosis, migration, autophagy as well as protein quality control. Bis expression is induced in response to a number of types of stress, such as heat shock or a proteasome inhibitor via the activation of heat shock factor (HSF)1. We report herein that Bis expression is increased at the transcriptional level in HK-2 kidney tubular cells and A172 glioma cells by exposure to oxidative stress such as H2O2 treatment and oxygen-glucose deprivation, respectively. The pretreatment of HK-2 cells with N-acetyl cysteine, suppressed Bis induction. Furthermore, HSF1 silencing attenuated Bis expression that was induced by H2O2, accompaniedby increase in reactive oxygen species (ROS) accumulation. Using a series of deletion constructs of the bis gene promoter, two putative heat shock elements located in the proximal region of the bis gene promoter were found to be essential for the constitutive expression is as well as the inducible expression of Bis. Taken together, our results indicate that oxidative stress induces Bis expression at the transcriptional levels via activation of HSF1, which might confer an expansion of antioxidant capacity against pro-oxidant milieu. However, the possible role of the other cis-element in the induction of Bis remains to be determined. PMID:25352760

[Individual variability of immunological markers, radiosensitivity and oxidative status in blood lymphocytes of Moscow residents].

PubMed

Pelevina, I I; Aleshchenko, A V; Antoshchina, M M; Kudriashova, O M; Nikonova, M F; Riabchenko, N I; Serebrianyĭ, A M; Iarilin, A A

2013-01-01

Expression of activation (CD69) and proliferation (Ki67) markers, their connection with each other, with the oxidative status (reactive oxygen species--ROS) and with radiosensitivity (determined by micronucleus test) have been studied on stimulated blood lymphocytes from Moscow inhabitants. It was shown that the content of T-lymphocytes with the expressed CD69 and the content of T-lymphocytes with the expressed Ki67 markers correlate (r = 0.571; p = 0.0004). We can suppose that expression of the CD69 marker (24 h after PHA stimulation) is needed for the cell cycle progression, but it is not enough for the high expression of Ki67 markers 48 h after stimulation (DNA synthesis phase). It was discovered that T-lymphocytes with the CD69 marker or T-lymphocytes with the Ki67 marker are connected by the negative correlation with the frequency of irradiated cell with micronucleus (MN) r = -0.487; p = 0.010; r = -0.440; p = 0.008, respectively. So we can suppose that lymphocyte radiosensitivity decreased with the increase of expression activation and proliferation markers. It was shown that radiosensitivity determined by MN test is not connected with the oxidative status determined by the reactive oxygen species content including superoxide anion radicals. It is possible to explain by the fact that the ROS concentration has been determined in non-stimulated lymphocytes, but frequencies of cells with MN - in the stimulated cells 48 h after stimulation. Using separate analysis of individual differences by the studied parameters that were determined in the same people, it was shown that individual differences are high enough in the same cases. For example, the radiosensitivity when cells were irradiated 48 h after stimulation, ROS concentration, cell content with activation and proliferation markers. In conclusion, we can say that we failed to find important correlation between the parameters studied. However, the presence of individual differences in the marker expression, the frequency of MN cells, the oxidative status in the usual inhabitants, typical donors in Moscow, is very important.

Proteins associated with critical sperm functions and sperm head shape are differentially expressed in morphologically abnormal bovine sperm induced by scrotal insulation.

PubMed

Shojaei Saadi, Habib A; van Riemsdijk, Evine; Dance, Alysha L; Rajamanickam, Gayathri D; Kastelic, John P; Thundathil, Jacob C

2013-04-26

The objective was to investigate expression patterns of proteins in pyriform sperm, a common morphological abnormality in bull sperm. Ejaculates were collected from sexually mature Holstein bulls (n=3) twice weekly for 10 weeks (pre-thermal insult samples). Testicular temperature was elevated in all bulls by scrotal insulation for 72 consecutive hours during week 2. Total sperm proteins were extracted from pre- and post-thermal insult sperm samples and subjected to two-dimensional gel electrophoresis. Among the protein spots detected, 131 spots were significantly expressed (False Detection Rate <0.01) with ≥ 2 fold changes between normal and pyriform sperm. Among them, 25 spots with ≥ 4 fold difference in expression patterns were identified using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Expression of several proteins involved in sperm capacitation, sperm-egg interaction and sperm cytoskeletal structure was decreased in pyriform sperm, whereas proteins regulating antioxidant activity, apoptosis and metabolic activity were increased. Contents of reactive oxygen species and ubiquitinated proteins were higher in pyriform sperm. In addition to understanding the molecular basis of functional deficiencies in sperm with specific morphological abnormalities, comparing normal versus morphologically abnormal sperm appeared to be a suitable experimental model for identifying important sperm functional proteins. To our knowledge, this study is the first report on differential expression of proteins in pyriform bovine sperm versus morphologically normal sperm. We report that expression of several proteins involved in sperm capacitation, sperm-egg interaction and sperm cytoskeletal structure was decreased in pyriform sperm, whereas proteins which regulate antioxidant activity, apoptosis and metabolic activity were increased. Contents of reactive oxygen species and ubiquitinated proteins were higher in pyriform sperm. In addition to understanding the molecular basis of functional deficiencies in sperm with specific morphological abnormalities, our results suggest that comparing normal versus morphologically abnormal sperm appeared to be a suitable experimental model for identifying important sperm functional proteins. Copyright © 2013 Elsevier B.V. All rights reserved.

Patterns of peroxidative ethane emission from submerged rice seedlings indicate that damage from reactive oxygen species takes place during submergence and is not necessarily a post-anoxic phenomenon.

PubMed

Santosa, I E; Ram, P C; Boamfa, E I; Laarhoven, L J J; Reuss, J; Jackson, M B; Harren, F J M

2007-06-01

Using ethane as a marker for peroxidative damage to membranes by reactive oxygen species (ROS) we examined the injury of rice seedlings during submergence in the dark. It is often expressed that membrane injury from ROS is a post-submergence phenomenon occurring when oxygen is re-introduced after submergence-induced anoxia. We found that ethane production, from rice seedlings submerged for 24-72 h, was stimulated to 4-37 nl gFW(-1), indicating underwater membrane peroxidation. When examined a week later the seedlings were damaged or had died. On de-submergence in air, ethane production rates rose sharply, but fell back to less than 0.1 nl gFW(-1) h(-1) after 2 h. We compared submergence-susceptible and submergence-tolerant cultivars, submergence starting in the morning (more damage) and in the afternoon (less damage) and investigated different submergence durations. The seedlings showed extensive fatality whenever total ethane emission exceeded about 15 nl gFW(-1). Smaller amounts of ethane emission were linked to less extensive injury to leaves. Partial oxygen shortage (O(2) levels <1%) imposed for 2 h in gas phase mixtures also stimulated ethane production. In contrast, seedlings under anaerobic gas phase conditions produced no ethane until re-aerated: then a small peak was observed followed by a low, steady ethane production. We conclude that damage during submergence is not associated with extensive anoxia. Instead, injury is linked to membrane peroxidation in seedlings that are partially oxygen deficient while submerged. On return to air, further peroxidation is suppressed within about 2 h indicating effective control of ROS production not evident during submergence itself.

ARSENIC SPECIES CAUSE RELEASE OF IRON FROM FERRITIN GENERATING REACTIVE OXYGEN SPECIES

EPA Science Inventory

ARSENIC SPECIES CAUSE RELEASE OF IRON FROM FERRITIN GENERATING REACTIVE OXYGEN SPECIES

Arsenic-associated cancer (lung, bladder, skin, liver, kidney) remains a significant world- wide public health problem (e.g., Taiwan, Chile, Bangladesh, India, China and Thailand). Rece...

Oxygen radicals as key mediators in neurological disease: fact or fiction?

PubMed

Halliwell, B

1992-01-01

A free radical is any species capable of independent existence that contains one or more unpaired electrons. Free radicals and other reactive oxygen species are frequently proposed to be involved in the pathology of several neurological disorders. Criteria for establishing such involvement are presented. Development of new methods for measuring oxidative damage should enable elucidation of the precise role of reactive oxygen species in neurological disorders.

Active site densities, oxygen activation and adsorbed reactive oxygen in alcohol activation on npAu catalysts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Lu-Cun; Friend, C. M.; Fushimi, Rebecca

The activation of molecular O 2as well as the reactivity of adsorbed oxygen species is of central importance in aerobic selective oxidation chemistry on Au-based catalysts. Herein, we address the issue of O 2activation on unsupported nanoporous gold (npAu) catalysts by applying a transient pressure technique, a temporal analysis of products (TAP) reactor, to measure the saturation coverage of atomic oxygen, its collisional dissociation probability, the activation barrier for O 2dissociation, and the facility with which adsorbed O species activate methanol, the initial step in the catalytic cycle of esterification. The results from these experiments indicate that molecular O 2dissociationmore » is associated with surface silver, that the density of reactive sites is quite low, that adsorbed oxygen atoms do not spill over from the sites of activation onto the surrounding surface, and that methanol reacts quite facilely with the adsorbed oxygen atoms. In addition, the O species from O 2dissociation exhibits reactivity for the selective oxidation of methanol but not for CO. The TAP experiments also revealed that the surface of the npAu catalyst is saturated with adsorbed O under steady state reaction conditions, at least for the pulse reaction.« less

Active site densities, oxygen activation and adsorbed reactive oxygen in alcohol activation on npAu catalysts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Lu-Cun; Friend, C. M.; Fushimi, Rebecca

2016-01-01

The activation of molecular O 2as well as the reactivity of adsorbed oxygen species is of central importance in aerobic selective oxidation chemistry on Au-based catalysts. Herein, we address the issue of O 2activation on unsupported nanoporous gold (npAu) catalysts by applying a transient pressure technique, a temporal analysis of products (TAP) reactor, to measure the saturation coverage of atomic oxygen, its collisional dissociation probability, the activation barrier for O 2dissociation, and the facility with which adsorbed O species activate methanol, the initial step in the catalytic cycle of esterification. The results from these experiments indicate that molecular O 2dissociationmore » is associated with surface silver, that the density of reactive sites is quite low, that adsorbed oxygen atoms do not spill over from the sites of activation onto the surrounding surface, and that methanol reacts quite facilely with the adsorbed oxygen atoms. In addition, the O species from O 2dissociation exhibits reactivity for the selective oxidation of methanol but not for CO. The TAP experiments also revealed that the surface of the npAu catalyst is saturated with adsorbed O under steady state reaction conditions, at least for the pulse reaction.« less

The Effects of Tempol on Cyclophosphamide-Induced Oxidative Stress in Rat Micturition Reflexes

PubMed Central

Gonzalez, Eric J.; Peterson, Abbey; Malley, Susan; Daniel, Mitchel; Lambert, Daniel; Kosofsky, Michael; Vizzard, Margaret A.

2015-01-01

We hypothesized that cyclophosphamide- (CYP-) induced cystitis results in oxidative stress and contributes to urinary bladder dysfunction. We determined (1) the expression of oxidative stress markers 3-nitrotyrosine (3-NT), reactive oxygen species (ROS)/reactive nitrogen species (RNS), inflammatory modulators, neuropeptides calcitonin gene-related peptide (CGRP), substance P (Sub P), and adenosine triphosphate (ATP) that contribute to the inflammatory process in the urinary tract and (2) the functional role of oxidative stress in urinary bladder dysfunction with an antioxidant, Tempol, (1 mM in drinking water) combined with conscious cystometry. In CYP-treated (4 hr or 48 hr; 150 mg/kg, i.p.) rats, ROS/RNS and 3-NT significantly (P ≤ 0.01) increased in urinary bladder. CYP treatment increased ATP, Sub P, and CGRP expression in the urinary bladder and cystometric fluid. In CYP-treated rats, Tempol significantly (P ≤ 0.01) increased bladder capacity and reduced voiding frequency compared to CYP-treated rats without Tempol. Tempol significantly (P ≤ 0.01) reduced ATP expression, 3-NT, and ROS/RNS expression in the urinary tract of CYP-treated rats. These studies demonstrate that reducing oxidative stress in CYP-induced cystitis improves urinary bladder function and reduces markers of oxidative stress and inflammation. PMID:25973443

Transcriptional upregulation of mitochondrial uncoupling protein 2 protects against oxidative stress-associated neurogenic hypertension.

PubMed

Chan, Samuel H H; Wu, Chiung-Ai; Wu, Kay L H; Ho, Ying-Hao; Chang, Alice Y W; Chan, Julie Y H

2009-10-23

Mitochondrial uncoupling proteins (UCPs) belong to a superfamily of mitochondrial anion transporters that uncouple ATP synthesis from oxidative phosphorylation and mitigates mitochondrial reactive oxygen species production. We assessed the hypothesis that UCP2 participates in central cardiovascular regulation by maintaining reactive oxygen species homeostasis in the rostral ventrolateral medulla (RVLM), where sympathetic premotor neurons that maintain vasomotor tone located. We also elucidated the molecular mechanisms that underlie transcriptional upregulation of UCP2 in response to oxidative stress in RVLM. In Sprague-Dawley rats, transcriptional upregulation of UCP2 in RVLM by rosiglitazone, an activator of its transcription factor peroxisome proliferator-activated receptor (PPAR)gamma, reduced mitochondrial hydrogen peroxide level in RVLM and systemic arterial pressure. Oxidative stress induced by microinjection of angiotensin II into RVLM augmented UCP2 mRNA or protein expression in RVLM, which was antagonized by comicroinjection of NADPH oxidase inhibitor (diphenyleneiodonium chloride), superoxide dismutase mimetic (tempol), or p38 mitogen-activated protein kinase inhibitor (SB203580) but not by extracellular signal-regulated kinase 1/2 inhibitor (U0126). Angiotensin II also induced phosphorylation of the PPARgamma coactivator, PPARgamma coactivator (PGC)-1alpha, and an increase in formation of PGC-1alpha/PPARgamma complexes in a p38 mitogen-activated protein kinase-dependent manner. Intracerebroventricular infusion of angiotensin II promoted an increase in mitochondrial hydrogen peroxide production in RVLM and chronic pressor response, which was potentiated by gene knockdown of UCP2 but blunted by rosiglitazone. These results suggest that transcriptional upregulation of mitochondrial UCP2 in response to an elevation in superoxide plays an active role in feedback regulation of reactive oxygen species production in RVLM and neurogenic hypertension associated with chronic oxidative stress.

SG2NA enhances cancer cell survival by stabilizing DJ-1 and thus activating Akt

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanti, Goutam Kumar, E-mail: goutamjnu@hotmail.com; Pandey, Shweta; Goswami, Shyamal K.

2015-08-07

SG2NA in association with striatin and zinedin forms a striatin family of WD-40 repeat proteins. This family of proteins functions as scaffold in different signal transduction pathways. They also act as a regulatory subunit of protein phosphatase 2A. We have shown that SG2NA which evolved first in the metazoan evolution among the striatin family members expresses different isoforms generated out of alternative splicing. We have also shown that SG2NA protects cells from oxidative stress by recruiting DJ-1 and Akt to mitochondria and membrane in the post-mitotic neuronal cells. DJ-1 is both cancer and Parkinson's disease related protein. In the presentmore » study we have shown that SG2NA protects DJ-1 from proteasomal degradation in cancer cells. Hence, downregulation of SG2NA reduces DJ-1/Akt colocalization in cancer cells resulting in the reduction of anchorage dependent and independent growth. Thus SG2NA enhances cancer cell survival. Reactive oxygen species enhances SG2NA, DJ-1 and Akt trimerization. Removal of the reactive oxygen species by N-acetyl-cysteine thus reduces cancer cell growth. - Highlights: • Reactive oxygen species (ROS) play potential role in cancer cell proliferation. • It enhances the association between DJ-1 and Akt mediated by SG2NA. • In cancer cells SG2NA stabilizes DJ-1 by inhibiting it from proteosomal degradation. • DJ-1 then activates Akt and cancer cells get their property of enhanced proliferation by sustained activation of Akt. • Further study on this field could lead to new target for cancer therapy.« less

Valsartan reduces AT1-AA-induced apoptosis through suppression oxidative stress mediated ER stress in endothelial progenitor cells.

PubMed

Wang, Z-C; Qi, J; Liu, L-M; Li, J; Xu, H-Y; Liang, B; Li, B

2017-03-01

Valsartan has been reported to have the function of treating hypertension and improving the prognosis of patients. Many studies indicated that valsartan can also increase angiotensin II, andosterone and plasma renin activity (PRA). Autoantibodies against the angiotensin II type 1 receptor (AT1-AA) have been showed to increase reactive oxygen species (ROS) and calcium (Ca2+) and result in apoptosis in vascular smooth muscle cells. In this study, we attempted to explore the effect of valsartan on AT1-AA-induced apoptosis in endothelial progenitor cells. Endothelial progenitor cells (EPCs) were cultured. The cytotoxicity was determined by MTT assay. EPCs apoptosis was determined by DAPI staining and flow cytometry. Reactive oxygen species, intracellular calcium concentration and calpain activity were measured using Fluostar Omega Spectrofluorimeter. The expression of p-ERK, p-eIF-2a, CHOP, Bcl-2 and caspase-3 were detected by Western blot. MTT assays showed valsartan significantly inhibited AT1-AA- induced decline of the viability of EPCs. DAPI staining and flow cytometry results indicated valsartan inhibited AT1-AA-induced decline of the viability of EPCs via inhibiting AT1-AA-induced apoptosis. Furthermore, the increasing of reactive oxygen species, intracellular calcium and calpain activity induced by AT1-AA in EPCs were also recovered after pre-treated with valsartan. Meanwhile, the upregulation of p-ERK, p-eIF-2a and CHOP, downregulation of Bcl-2, and activation of Caspase-3 caused by AT1-AA were reversed after pre-incubated with valsartan. Valsartan could inhibit AT1-AA-induced apoptosis through inhibiting oxidative stress mediated ER stress in EPCs.

Roux-en-Y gastric bypass improves glucose homeostasis, reduces oxidative stress and inflammation in livers of obese rats and in Kupffer cells via an AMPK-dependent pathway.

PubMed

Peng, Yanhua; Li, James Zongyu; You, Min; Murr, Michel M

2017-07-01

Oxidative stress and inflammation are implicated in the pathogenesis of steatohepatitis. We hypothesize that Roux-en-Y gastric bypass reduces oxidative stress and inflammation in the liver of obese rats via activation of AMPK-α. Obese Sprague-Dawley male rats underwent either sham operation or Roux-en-Y gastric bypass. Hepatic TNF-α, NF-κB, IRS-2, PI3 kinase, PKC-ζ, NOX2, and AMPK-α were measured. Mechanistic studies were done in a rat Kupffer cell line (RKC1) that was treated with free fatty acids to mimic lipotoxicity and then transfected with AMPK-α siRNA. Reactive oxygen species, TNF-α, NF-κB, AMPK-α, p-AMPK-α, PPAR-γ, and NOX2 were measured. A t test was used. Roux-en-Y gastric bypass lowered nonfasting serum glucose, improved the glucose tolerance test, and induced IRS2/PI3 kinase interaction. Additionally, Roux-en-Y gastric bypass decreased hepatic NOX2, PKC-ζ, TNF-α expression and activation of NF-κB. Free fatty acids increased reactive oxygen species, TNF-α protein, NOX2 protein, and activated NF-κB. Rosiglitazone attenuated the free fatty acids-induced increase in reactive oxygen species, TNF-α, NOX2, and NF-κB; blocking AMPK-α by siRNA abolished the effects of rosiglitazone. Roux-en-Y gastric bypass exhibits antidiabetic properties and is associated with downregulation of proinflammation genes and oxidative stress in the liver and within Kupffer cells via activation of AMPK-α. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of Pseudomonas aeruginosa virulence factor pyocyanin on human urothelial cell function and viability.

PubMed

McDermott, Catherine; Chess-Williams, Russ; Grant, Gary D; Perkins, Anthony V; McFarland, Amelia J; Davey, Andrew K; Anoopkumar-Dukie, Shailendra

2012-03-01

We determined the effects of Pseudomonas aeruginosa virulence factor pyocyanin on human urothelial cell viability and function in vitro. RT4 urothelial cells were treated with pyocyanin (1 to 100 μM) for 24 hours. After exposure the treatment effects were measured according to certain end points, including changes in urothelial cell viability, reactive oxygen species formation, caspase-3 activity, basal and stimulated adenosine triphosphate release, SA-β-gal activity and detection of acidic vesicular organelles. The 24-hour pyocyanin treatment resulted in a concentration dependent decrease in cell viability at concentrations of 25 μM or greater, and increases in reactive oxygen species formation and caspase-3 activity at 25 μM or greater. Basal adenosine triphosphate release was significantly decreased at all tested pyocyanin concentrations while stimulated adenosine triphosphate release was significantly inhibited at pyocyanin concentrations of 12.5 μM or greater with no significant stimulated release at 100 μM. Pyocyanin treated RT4 cells showed morphological characteristics associated with cellular senescence, including SA-β-gal expression. This effect was not evident at 100 μM pyocyanin and may have been due to apoptotic cell death, as indicated by increased caspase-3 activity. An increase in acridine orange stained vesicular-like organelles was observed in RT4 urothelial cells after pyocyanin treatment. Exposure to pyocyanin alters urothelial cell viability, reactive oxygen species production and caspase-3 activity. Treatment also results in cellular senescence, which may affect the ability of urothelium to repair during infection. The virulence factor depressed stimulated adenosine triphosphate release, which to our knowledge is a novel finding with implications for awareness of bladder filling in patients with P. aeruginosa urinary tract infection. Copyright © 2012 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Erythrocyte oxidative stress markers in children with sickle cell disease.

PubMed

Hermann, Priscila Bacarin; Pianovski, Mara Albonei Dudeque; Henneberg, Railson; Nascimento, Aguinaldo José; Leonart, Maria Suely Soares

2016-01-01

To determine eight parameters of oxidative stress markers in erythrocytes from children with sickle cell disease and compare with the same parameters in erythrocytes from healthy children, since oxidative stress plays an important role in the pathophysiology of sickle cell disease and because this disease is a serious public health problem in many countries. Blood samples were obtained from 45 children with sickle cell disease (21 males and 24 females with a mean age of 9 years; range: 3-13 years) and 280 blood samples were obtained from children without hemoglobinopathies (137 males and 143 females with a mean age of 10 years; range: 8-11 years), as a control group. All blood samples were analyzed for methemoglobin, reduced glutathione, thiobarbituric acid reactive substances, percentage of hemolysis, reactive oxygen species, and activity of the enzymes glucose 6-phosphate dehydrogenase, superoxide dismutase, and catalase. Data were analyzed using Student's t-test and were expressed as the mean±standard deviation. A p-value of <0.05 was considered significant. Significant differences were observed between children with sickle cell disease and the control group for the parameters methemoglobin, thiobarbituric acid reactive substances, hemolysis, glucose 6-phosphate dehydrogenase activity, and reactive oxygen species, with higher levels in the patients than in the controls. Oxidative stress parameters in children's erythrocytes were determined using simple laboratory methods with small volumes of blood; these biomarkers can be useful to evaluate disease progression and outcomes in patients. Copyright © 2016 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Enhancement of UVB radiation-mediated apoptosis by knockdown of cytosolic NADP+-dependent isocitrate dehydrogenase in HaCaT cells.

PubMed

Lee, Su Jeong; Park, Jeen-Woo

2014-04-01

Ultraviolet B (UVB) radiation induces the production of reactive oxygen species (ROS) that promote apoptotic cell death. We showed that cytosolic NADP+-dependent isocitrate dehydrogenase (IDPc) plays an essential role in the control of cellular redox balance and defense against oxidative damage, by supplying NADPH for antioxidant systems. In this study, we demonstrated that knockdown of IDPc expression by RNA interference enhances UVB-induced apoptosis of immortalized human HaCaT keratinocytes. This effect manifested as DNA fragmentation, changes in cellular redox status, mitochondrial dysfunction, and modulation of apoptotic marker expression. Based on our findings, we suggest that attenuation of IDPc expression may protect skin from UVB-mediated damage, by inducing the apoptosis of UV-damaged cells.

Redox control of protein-DNA interactions: from molecular mechanisms to significance in signal transduction, gene expression, and DNA replication.

PubMed

Shlomai, Joseph

2010-11-01

Protein-DNA interactions play a key role in the regulation of major cellular metabolic pathways, including gene expression, genome replication, and genomic stability. They are mediated through the interactions of regulatory proteins with their specific DNA-binding sites at promoters, enhancers, and replication origins in the genome. Redox signaling regulates these protein-DNA interactions using reactive oxygen species and reactive nitrogen species that interact with cysteine residues at target proteins and their regulators. This review describes the redox-mediated regulation of several master regulators of gene expression that control the induction and suppression of hundreds of genes in the genome, regulating multiple metabolic pathways, which are involved in cell growth, development, differentiation, and survival, as well as in the function of the immune system and cellular response to intracellular and extracellular stimuli. It also discusses the role of redox signaling in protein-DNA interactions that regulate DNA replication. Specificity of redox regulation is discussed, as well as the mechanisms providing several levels of redox-mediated regulation, from direct control of DNA-binding domains through the indirect control, mediated by release of negative regulators, regulation of redox-sensitive protein kinases, intracellular trafficking, and chromatin remodeling.

MINIMAL ROLE FOR REACTIVE OXYGEN SPECIES IN DICHLOROACETIC ACID-INDUCED DYSMORPHOLOGY IN MOUSE WHOLE EMBRYO CULTURE.

EPA Science Inventory

Administration of dichloroacetate (DCA) to pregnant rats produces craniofacial, heart and other defects in their offspring. Exposure of zebrafish to DCA induces malformations and increases superoxide and nitric oxide production suggesting that reactive oxygen species (ROS) are as...

Edaravone Guards Dopamine Neurons in a Rotenone Model for Parkinson's Disease

PubMed Central

Chen, Chunnuan; Huang, Jinsha; Zhao, Ying; Zhang, Zhentao; Qiao, Xian; Feng, Yuan; Reesaul, Harrish; Zhang, Yongxue; Sun, Shenggang; Lin, Zhicheng; Wang, Tao

2011-01-01

3-methyl-1-phenyl-2-pyrazolin-5-one (edaravone), an effective free radical scavenger, provides neuroprotection in stroke models and patients. In this study, we investigated its neuroprotective effects in a chronic rotenone rat model for Parkinson's disease. Here we showed that a five-week treatment with edaravone abolished rotenone's activity to induce catalepsy, damage mitochondria and degenerate dopamine neurons in the midbrain of rotenone-treated rats. This abolishment was attributable at least partly to edaravone's inhibition of rotenone-induced reactive oxygen species production or apoptotic promoter Bax expression and its up-regulation of the vesicular monoamine transporter 2 (VMAT2) expression. Collectively, edaravone may provide novel clinical therapeutics for PD. PMID:21677777

Transient heat and mass transfer analysis in a porous ceria structure of a novel solar redox reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chandran, RB; Bader, R; Lipinski, W

2015-06-01

Thermal transport processes are numerically analyzed for a porous ceria structure undergoing reduction in a novel redox reactor for solar thermochemical fuel production. The cylindrical reactor cavity is formed by an array of annular reactive elements comprising the porous ceria monolith integrated with gas inlet and outlet channels. Two configurations are considered, with the reactor cavity consisting of 10 and 20 reactive elements, respectively. Temperature dependent boundary heat fluxes are obtained on the irradiated cavity wall by solving for the surface radiative exchange using the net radiation method coupled to the heat and mass transfer model of the reactive element.more » Predicted oxygen production rates are in the range 40-60 mu mol s(-1) for the geometries considered. After an initial rise, the average temperature of the reactive element levels off at 1660 and 1680 K for the two geometries, respectively. For the chosen reduction reaction rate model, oxygen release continues after the temperature has leveled off which indicates that the oxygen release reaction is limited by chemical kinetics and/or mass transfer rather than by the heating rate. For a fixed total mass of ceria, the peak oxygen release rate is doubled for the cavity with 20 reactive elements due to lower local oxygen partial pressure. (C) 2015 Elsevier Masson SAS. All rights reserved.« less

Modified C-reactive protein is expressed by stroke neovessels and is a potent activator of angiogenesis in vitro.

PubMed

Slevin, Mark; Matou-Nasri, Sabine; Turu, Marta; Luque, Ana; Rovira, Norma; Badimon, Lina; Boluda, Susana; Potempa, Lawrence; Sanfeliu, Coral; de Vera, Nuria; Krupinski, Jerzy

2010-01-01

Native C-reactive protein (nCRP) is a pentameric oligo-protein and an acute phase reactant whose serum expression is increased in patients with inflammatory disease. We have identified by immunohistochemistry, significant expression of a tissue-binding insoluble modified version or monomeric form of CRP (mCRP) associated with angiogenic microvessels in peri-infarcted regions of patients studied with acute ischaemic stroke. mCRP, but not nCRP was expressed in the cytoplasm and nucleus of damaged neurons. mCRP co-localized with CD105, a marker of angiogenesis in regions of revascularisation. In vitro investigations demonstrated that mCRP was preferentially expressed in human brain microvessel endothelial cells following oxygen-glucose deprivation and mCRP (but not column purified nCRP) associated with the endothelial cell surface, and was angiogenic to vascular endothelial cells, stimulating migration and tube formation in matrigel more strongly than fibroblast growth factor-2. The mechanism of signal transduction was not through the CD16 receptor. Western blotting showed that mCRP stimulated phosphorylation of the key down-stream mitogenic signalling protein ERK1/2. Pharmacological inhibition of ERK1/2 phosphorylation blocked the angiogenic effects of mCRP. We propose that mCRP may contribute to the neovascularization process and because of its abundant presence, be important in modulating angiogenesis in both acute stroke and later during neuro-recovery.

Melatonin Scavenger Properties against Oxidative and Nitrosative Stress: Impact on Gamete Handling and In Vitro Embryo Production in Humans and Other Mammals

PubMed Central

Loren, Pía; Sánchez, Raúl; Arias, María-Elena; Felmer, Ricardo; Risopatrón, Jennie; Cheuquemán, Carolina

2017-01-01

Oxidative and nitrosative stress are common problems when handling gametes in vitro. In vitro development in mammalian embryos is highly affected by culture conditions, especially by reactive oxygen species (ROS) and reactive nitrogen species (RNS), because their absence or overproduction causes embryo arrest and changes in gene expression. Melatonin in gamete co-incubation during in vitro fertilization (IVF) has deleterious or positive effects, depending on the concentration used in the culture medium, demonstrating the delicate balance between antioxidant and pro-oxidant activity. Further research is needed to better understand the possible impact of melatonin on the different IVP steps in humans and other mammals, especially in seasonal breeds where this neuro-hormone system highly regulates its reproduction physiology. PMID:28613231

Melatonin-induced increase in sensitivity of human hepatocellular carcinoma cells to sorafenib is associated with reactive oxygen species production and mitophagy

PubMed Central

Prieto-Domínguez, Néstor; Ordóñez, Raquel; Fernández, Anna; Méndez-Blanco, Carolina; Baulies, Anna; Garcia-Ruiz, Carmen; Fernández-Checa, José C.; Mauriz, José L.; González-Gallego, Javier

2016-01-01

Effects of sorafenib in hepatocellular carcinoma (HCC) are frequently transient due to tumor-acquired resistance, a phenotype that could be targeted by other molecules to reduce this adaptive response. Because melatonin is known to exert antitumor effects in HCC cells, this study investigated whether and how melatonin reduces resistance to sorafenib. Susceptibility to sorafenib (10 nM to 50 μM) in the presence of melatonin (1 and 2 mM) was assessed in HCC cell lines HepG2, HuH7 and Hep3B. Cell viability was reduced by sorafenib from 1 μM in HepG2 or HuH7 cells, and 2.5 μM in Hep3B cells. Co-administration of melatonin and sorafenib exhibited a synergistic cytotoxic effect on HepG2 and HuH7 cells, while Hep3B cells displayed susceptibility to doses of sorafenib that had no effect when administrated alone. Co-administration of 2.5 μM sorafenib and 1 mM melatonin induced apoptosis in Hep3B cells, increasing PARP hydrolysis and BAX expression. We also observed an early colocalization of mitochondria with lysosomes, correlating with the expression of mitophagy markers PINK1 and Parkin and a reduction of mitofusin-2 and mtDNA compared with sorafenib administration alone. Moreover, increased reactive oxygen species production and mitochondrial membrane depolarization were elicited by drug combination, suggesting their contribution to mitophagy induction. Interestingly, Parkin silencing by siRNA to impair mitophagy significantly reduced cell killing, PARP cleavage and BAX expression. These results demonstrate that the pro-oxidant capacity of melatonin and its impact on mitochondria stability and turnover via mitophagy increase sensitivity to the cytotoxic effect of sorafenib. PMID:27484637

Quinolinic acid induces neuritogenesis in SH-SY5Y neuroblastoma cells independently of NMDA receptor activation.

PubMed

Hernandez-Martinez, Juan-Manuel; Forrest, Caroline M; Darlington, L Gail; Smith, Robert A; Stone, Trevor W

2017-03-01

Glutamate and nicotinamide adenine dinucleotide (NAD + ) have been implicated in neuronal development and several types of cancer. The kynurenine pathway of tryptophan metabolism includes quinolinic acid (QA) which is both a selective agonist at N-methyl-D-aspartate (NMDA) receptors and also a precursor for the formation of NAD + . The effect of QA on cell survival and differentiation has therefore been examined on SH-SY5Y human neuroblastoma cells. Retinoic acid (RA, 10 μm) induced differentiation of SH-SY5Y cells into a neuronal phenotype showing neurite growth. QA (50-150 nm) also caused a concentration-dependent increase in the neurite/soma ratio, indicating differentiation. Both RA and QA increased expression of the neuronal marker β3-tubulin in whole-cell homogenates and in the neuritic fraction assessed using a neurite outgrowth assay. Expression of the neuronal proliferation marker doublecortin revealed that, unlike RA, QA did not decrease the number of mitotic cells. QA-induced neuritogenesis coincided with an increase in the generation of reactive oxygen species. Neuritogenesis was prevented by diphenylene-iodonium (an inhibitor of NADPH oxidase) and superoxide dismutase, supporting the involvement of reactive oxygen species. NMDA itself did not promote neuritogenesis and the NMDA antagonist dizocilpine (MK-801) did not prevent quinolinate-induced neuritogenesis, indicating that the effects of QA were independent of NMDA receptors. Nicotinamide caused a significant increase in the neurite/soma ratio and the expression of β3-tubulin in the neuritic fraction. Taken together, these results suggest that QA induces neuritogenesis by promoting oxidizing conditions and affecting the availability of NAD + , independently of NMDA receptors. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Combination of tolfenamic acid and curcumin induces colon cancer cell growth inhibition through modulating specific transcription factors and reactive oxygen species.

PubMed

Sankpal, Umesh T; Nagaraju, Ganji Purnachandra; Gottipolu, Sriharika R; Hurtado, Myrna; Jordan, Christopher G; Simecka, Jerry W; Shoji, Mamoru; El-Rayes, Bassel; Basha, Riyaz

2016-01-19

Curcumin (Cur) has been extensively studied in several types of malignancies including colorectal cancer (CRC); however its clinical application is greatly affected by low bioavailability. Several strategies to improve the therapeutic response of Cur are being pursued, including its combination with small molecules and drugs. We investigated the therapeutic efficacy of Cur in combination with the small molecule tolfenamic acid (TA) in CRC cell lines. TA has been shown to inhibit the growth of human cancer cells in vitro and in vivo, via targeting the transcription factor specificity protein1 (Sp1) and suppressing survivin expression. CRC cell lines HCT116 and HT29 were treated with TA and/or Cur and cell viability was measured 24-72 hours post-treatment. While both agents caused a steady reduction in cell viability, following a clear dose/ time-dependent response, the combination of TA+Cur showed higher growth inhibition when compared to either single agent. Effects on apoptosis were determined using flow cytometry (JC-1 staining to measure mitochondrial membrane potential), Western blot analysis (c-PARP expression) and caspase 3/7 activity. Reactive oxygen species (ROS) levels were measured by flow cytometry and the translocation of NF-kB into the nucleus was determined using immunofluorescence. Results showed that apoptotic markers and ROS activity were significantly upregulated following combination treatment, when compared to the individual agents. This was accompanied by decreased expression of Sp1, survivin and NF-kB translocation. The combination of TA+Cur was more effective in HCT116 cells than HT29 cells. These results demonstrate that TA may enhance the anti-proliferative efficacy of Cur in CRC cells.

PKCα promotes generation of reactive oxygen species via DUOX2 in hepatocellular carcinoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Jiajun; Shao, Miaomiao; Liu, Min

2015-08-07

Hepatocellular carcinoma (HCC) remains the second leading cause of cancer-related death worldwide, and elevated rates of reactive oxygen species (ROS) have long been considered as a hallmark of almost all types of cancer including HCC. Protein kinase C alpha (PKCα), a serine/threonine kinase among conventional PKC family, is recognized as a major player in signal transduction and tumor progression. Overexpression of PKCα is commonly observed in human HCC and associated with its poor prognosis. However, how PKCα is involved in hepatocellular carcinogenesis remains not fully understood. In this study, we found that among the members of conventional PKC family, PKCα,more » but not PKCβI or βII, promoted ROS production in HCC cells. PKCα stimulated generation of ROS by up-regulating DUOX2 at post-transcriptional level. Depletion of DUOX2 abrogated PKCα-induced activation of AKT/MAPK pathways as well as cell proliferation, migration and invasion in HCC cells. Moreover, the expression of DUOX2 and PKCα was well positively correlated in both HCC cell lines and patient samples. Collectively, our findings demonstrate that PKCα plays a critical role in HCC development by inducing DUOX2 expression and ROS generation, and propose a strategy to target PKCα/DUOX2 as a potential adjuvant therapy for HCC treatment. - Highlights: • PKCα promotes the generation of ROS in hepatocellular carcinoma. • PKCα induces ROS production by up-regulating DUOX2 at post-transcriptional level. • DUOX2 is required for PKCα-induced AKT/MAPK activation and tumor progression in HCC. • The expression of PKCα is positively correlated with DUOX2 in HCC.« less

Central role of endogenous Toll-like receptor-2 activation in regulating inflammation, reactive oxygen species production, and subsequent neointimal formation after vascular injury

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shishido, Tetsuro; Nozaki, Naoki; Takahashi, Hiroki

2006-07-14

Background: It is now evident that inflammation after vascular injury has significant impact on the restenosis after revascularization procedures such as angioplasty, stenting, and bypass grafting. However, the mechanisms that regulate inflammation and repair after vascular injury are incompletely understood. Here, we report that vascular injury-mediated cytokine expression, reactive oxygen species (ROS) production, as well as subsequent neointimal formation requires Toll-like receptor-2 (TLR-2) mediated signaling pathway in vivo. Methods and results: Vascular injury was induced by cuff-placement around the femoral artery in non-transgenic littermates (NLC) and TLR-2 knockout (TLR-2KO) mice. After cuff-placement in NLC mice, expression of TLR-2 was significantlymore » increased in both smooth muscle medial layer and adventitia. Interestingly, we found that inflammatory genes expression such as tumor necrosis factor-{alpha}, interleukin-1{beta} (IL-1{beta}), IL-6, and monocyte chemoattractant protein-1 were markedly decreased in TLR-2KO mice compared with NLC mice. In addition, ROS production after vascular injury was attenuated in TLR-2KO mice compared with NLC mice. Since we observed the significant role of endogenous TLR-2 activation in regulating inflammatory responses and ROS production after vascular injury, we determined whether inhibition of endogenous TLR-2 activation can inhibit neointimal proliferation after vascular injury. Neointimal hyperplasia was markedly suppressed in TLR-2KO mice compared with WT mice at both 2 and 4 weeks after vascular injury. Conclusions: These findings suggested that endogenous TLR-2 activation might play a central role in the regulation of vascular inflammation as well as subsequent neointimal formation in injured vessels.« less

Cysteine oxidation impairs systemic glucocorticoid responsiveness in children with difficult-to-treat asthma.

PubMed

Stephenson, Susan T; Brown, Lou Ann S; Helms, My N; Qu, Hongyan; Brown, Sheena D; Brown, Milton R; Fitzpatrick, Anne M

2015-08-01

The mechanisms underlying glucocorticoid responsiveness are largely unknown. Although redox regulation of the glucocorticoid receptor (GR) has been reported, it has not been studied in asthmatic patients. We characterized systemic cysteine oxidation and its association with inflammatory and clinical features in healthy children and children with difficult-to-treat asthma. We hypothesized that cysteine oxidation would be associated with increased markers of oxidative stress and inflammation, increased features of asthma severity, decreased clinically defined glucocorticoid responsiveness, and impaired GR function. PBMCs were collected from healthy children (n = 16) and children with asthma (n = 118) aged 6 to 17 years. Children with difficult-to-treat asthma underwent glucocorticoid responsiveness testing with intramuscular triamcinolone. Cysteine, cystine, and inflammatory chemokines and reactive oxygen species generation were quantified, and expression and activity of the GR were assessed. Cysteine oxidation was present in children with difficult-to-treat asthma and accompanied by increased reactive oxygen species generation and increased CCL3 and CXCL1 mRNA expression. Children with the greatest extent of cysteine oxidation had more features of asthma severity, including poorer symptom control, greater medication use, and less glucocorticoid responsiveness despite inhaled glucocorticoid therapy. Cysteine oxidation also modified the GR protein by decreasing available sulfhydryl groups and decreasing nuclear GR expression and activity. A highly oxidized cysteine redox state promotes a posttranslational modification of the GR that might inhibit its function. Given that cysteine oxidation is prevalent in children with difficult-to-treat asthma, the cysteine redox state might represent a potential therapeutic target for restoration of glucocorticoid responsiveness in this population. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Regulation of H2O2 stress-responsive genes through a novel transcription factor in the protozoan pathogen Entamoeba histolytica.

PubMed

Pearson, Richard J; Morf, Laura; Singh, Upinder

2013-02-08

Outcome of infection depends upon complex interactions between the invading pathogen and the host. As part of the host's innate immune response, the release of reactive oxygen and nitrogen species by phagocytes represents a major obstacle to the establishment of infection. The ability of the human parasite Entamoeba histolytica to survive reactive oxygen and nitrogen species is central to its pathogenic potential and contributes to disease outcome. In order to define the transcriptional network associated with oxidative stress, we utilized the MEME and MAST programs to analyze the promoter regions of 57 amoebic genes that had increased expression specifically in response to H(2)O(2) exposure. We functionally characterized an H(2)O(2)-regulatory motif (HRM) ((1)AAACCTCAATGAAGA(15)), which was enriched in these promoters and specifically bound amoebic nuclear protein(s). Assays with promoter-luciferase fusions established the importance of key residues and that the HRM motif directly impacted the ability of H(2)O(2)-responsive promoters to drive gene expression. DNA affinity chromatography and mass spectrometry identified EHI_108720 as an HRM DNA-binding protein. Overexpression and down-regulation of EHI_108720 demonstrated the specificity of EHI_108720 protein binding to the HRM, and overexpression increased basal expression from an H(2)O(2)-responsive wild-type promoter but not from its mutant counterpart. Thus, EHI_108720, or HRM-binding protein, represents a new stress-responsive transcription factor in E. histolytica that controls a transcriptional regulatory network associated with oxidative stress. Overexpression of EHI_108720 increased parasite virulence. Insight into how E. histolytica responds to oxidative stress increases our understanding of how this important human pathogen establishes invasive disease.

SNP in TXNRD2 Associated With Radiation-Induced Fibrosis: A Study of Genetic Variation in Reactive Oxygen Species Metabolism and Signaling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edvardsen, Hege, E-mail: hege.edvardsen@rr-research.no; K. G. Jebsen Breast cancer centre, Institute for Clinical Medicine, University of Oslo, Oslo; Landmark-Høyvik, Hege

Purpose: The aim of the study was to identify noninvasive markers of treatment-induced side effects. Reactive oxygen species (ROS) are generated after irradiation, and genetic variation in genes related to ROS metabolism might influence the level of radiation-induced adverse effects (AEs). Methods and Materials: 92 breast cancer (BC) survivors previously treated with hypofractionated radiation therapy were assessed for the AEs subcutaneous atrophy and fibrosis, costal fractures, lung fibrosis, pleural thickening, and telangiectasias (median follow-up time 17.1 years). Single-nucleotide polymorphisms (SNPs) in 203 genes were analyzed for association to AE grade. SNPs associated with subcutaneous fibrosis were validated in an independentmore » BC survivor material (n=283). The influence of the studied genetic variation on messenger ribonucleic acid (mRNA) expression level of 18 genes previously associated with fibrosis was assessed in fibroblast cell lines from BC patients. Results: Subcutaneous fibrosis and atrophy had the highest correlation (r=0.76) of all assessed AEs. The nonsynonymous SNP rs1139793 in TXNRD2 was associated with grade of subcutaneous fibrosis, the reference T-allele being more prevalent in the group experiencing severe levels of fibrosis. This was confirmed in another sample cohort of 283 BC survivors, and rs1139793 was found significantly associated with mRNA expression level of TXNRD2 in blood. Genetic variation in 24 ROS-related genes, including EGFR, CENPE, APEX1, and GSTP1, was associated with mRNA expression of 14 genes previously linked to fibrosis (P≤.005). Conclusion: Development of subcutaneous fibrosis can be associated with genetic variation in the mitochondrial enzyme TXNRD2, critically involved in removal of ROS, and maintenance of the intracellular redox balance.« less

Surgery-derived reactive oxygen species produced by polymorphonuclear leukocytes promote tumor recurrence: studies in an in vitro model.

PubMed

van Grevenstein, Wilhelmina M U; Aalbers, Arend G J; Ten Raa, Sander; Sluiter, Wim; Hofland, Leo J; Jeekel, Hans; van Eijck, Casper H J

2007-06-01

Tissue injury induces the acute phase response, aimed at minimizing damage and starting the healing process. Polymorphonuclear leukocytes (PMNs) respond to the presence of specific chemoattractants and begin to appear in large numbers. The aim of this study was to investigate the influence of reactive oxygen species (ROS) produced by PMNs on the interaction between colon carcinoma cells and mesothelial cells. An experimental human in vitro model was designed using Caco-2 colon carcinoma cells and primary cultures of mesothelial cells. Tumor cell adhesion to a mesothelial monolayer was assessed after preincubation of the mesothelium with stimulated PMNs and unstimulated PMNs. Mesothelial cells were also incubated with xanthine/xanthine oxidase (X/XO) complex producing ROS after which adhesion of Caco-2 cells was investigated and the expression of adhesion molecules (ICAM-1, VCAM-1, and CD44) by means of enzyme immunoassay. In the control situation the average adhesion of Caco-2 cells to the mesothelial monolayers was 23%. Mesothelial monolayers incubated with unstimulated PMNs showed a 25% increase of tumor cell adhesion (P < 0.05). The adhesion of tumor to the monolayers incubated with the N-formyl-methionyl-leucyl-phenylalanine-stimulated PMNs increased with 40% (P < 0.01). Incubation of the mesothelium with X/XO resulted in an enhancement of adhesion of Caco-2 cells of 70% and an up-regulation of expression of ICAM-1, VCAM-1, and CD44. This study reveals an increase of tumor cell adhesion to the mesothelium induced by incubating the mesothelial monolayers with PMNs. PMNs are producing a number of products, like proteolytic enzymes, cytokines, and ROS. These factors up-regulate the expression of adhesion molecules and in that way stimulate the adhesion of tumor to the mesothelium.

Photobiomodulation partially rescues visual cortical neurons from cyanide-induced apoptosis.

PubMed

Liang, H L; Whelan, H T; Eells, J T; Meng, H; Buchmann, E; Lerch-Gaggl, A; Wong-Riley, M

2006-05-12

Near-infrared light via light-emitting diode treatment has documented therapeutic effects on neurons functionally inactivated by tetrodotoxin or methanol intoxication. Light-emitting diode pretreatment also reduced potassium cyanide-induced cell death, but the mode of death via the apoptotic or necrotic pathway was unclear. The current study tested our hypothesis that light-emitting diode rescues neurons from apoptotic cell death. Primary neuronal cultures from postnatal rat visual cortex were pretreated with light-emitting diode for 10 min at a total energy density of 30 J/cm2 before exposing to potassium cyanide for 28 h. With 100 or 300 microM potassium cyanide, neurons died mainly via the apoptotic pathway, as confirmed by electron microscopy, Hoechst 33258, single-stranded DNA, Bax, and active caspase-3. In the presence of caspase inhibitor I, the percentage of apoptotic cells in 300microM potassium cyanide was significantly decreased. Light-emitting diode pretreatment reduced apoptosis from 36% to 17.9% (100 microM potassium cyanide) and from 58.9% to 39.6% (300 microM potassium cyanide), representing a 50.3% and 32.8% reduction, respectively. Light-emitting diode pretreatment significantly decreased the expression of caspase-3 elicited by potassium cyanide. It also reversed the potassium cyanide-induced increased expression of Bax and decreased expression of Bcl-2 to control levels. Moreover, light-emitting diode decreased the intensity of 5-(and -6) chloromethy-2', 7-dichlorodihydrofluorescein diacetate acetyl ester, a marker of reactive oxygen species, in neurons exposed to 300 microM potassium cyanide. These results indicate that light-emitting diode pretreatment partially protects neurons against cyanide-induced caspase-mediated apoptosis, most likely by decreasing reactive oxygen species production, down-regulating pro-apoptotic proteins and activating anti-apoptotic proteins, as well as increasing energy metabolism in neurons as reported previously.

Insufficiency of pro-heparin-binding epidermal growth factor-like growth factor shedding enhances hypoxic cell death in H9c2 cardiomyoblasts via the activation of caspase-3 and c-Jun N-terminal kinase.

PubMed

Uetani, Teruyoshi; Nakayama, Hironao; Okayama, Hideki; Okura, Takafumi; Higaki, Jitsuo; Inoue, Hirofumi; Higashiyama, Shigeki

2009-05-01

Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a cardiogenic and cardiohypertrophic growth factor. ProHB-EGF, a product of the Hb-egf gene and the precursor of HB-EGF, is anchored to the plasma membrane. Its ectodomain region is shed by a disintegrin and metalloproteases (ADAMs) when activated by various stimulations. It has been reported that an uncleavable mutant of Hb-egf, uc-Hb-egf, produces uc-proHB-EGF, which is not cleaved by ADAMs and causes dilation of the heart in knock-in mice. This suggests that the shedding of proHB-EGF is essential for the development and survival of cardiomyocytes: however, the molecular mechanism involved has remained unclear. In this study, we investigated the relationship between uc-proHB-EGF expression and cardiomyocyte survival. Human uc-proHB-EGF was adenovirally introduced into the rat cardiomyoblast cell line H9c2, and the cells were cultured under normoxic and hypoxic conditions. Uc-proHB-EGF-expressing H9c2 cells underwent apoptosis under normoxic conditions, which distinctly increased under hypoxic conditions. Furthermore, we observed an increased Caspase-3 activity, reactive oxygen species accumulation, and an increased c-Jun N-terminal kinase (JNK) activity in the uc-proHB-EGF-expressing H9c2 cells. Treatment of the uc-proHB-EGF transfectants with inhibitors of Caspase-3, reactive oxygen species, and JNK, namely, Z-VAD-fmk, N-acetylcysteine, and SP600125, respectively, significantly reduced hypoxic cell death. These data indicate that insufficiency of proHB-EGF shedding under hypoxic stress leads to cardiomyocyte apoptosis via Caspase-3- and JNK-dependent pathways.

Sibutramine provokes apoptosis of aortic endothelial cells through altered production of reactive oxygen and nitrogen species

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morikawa, Yoshifumi

Overdose administration of sibutramine, a serotonin-noradrenalin reuptake inhibitor, is considered to elicit severe side effects including hypertension, whose pathogenic mechanism remains unclear. Here, we found that 48-h incubation with > 10 μM sibutramine provokes apoptosis of human aortic endothelial (HAE) cells. Treatment with the lethal concentration of sibutramine facilitated production of reactive oxygen species (ROS), altered expression of endoplasmic reticulum stress response genes (heat shock protein 70 and C/EBP homologous protein), and inactivated 26S proteasome-based proteolysis. The treatment also decreased cellular level of nitric oxide (NO) through lowering of expression and activity of endothelial NO synthase. These results suggest thatmore » ROS production and depletion of NO are crucial events in the apoptotic mechanism and may be linked to the pathogenesis of vasoconstriction elicited by the drug. Compared to sibutramine, its metabolites (N-desmethylsibutramine and N-didesmethylsibutramine) were much less cytotoxic to HAE cells, which hardly metabolized sibutramine. In contrast, both the drug and metabolites showed low cytotoxicity to hepatic HepG2 cells with high metabolic potency and expression of cytochrome P450 (CYP) 3A4. The cytotoxicity of sibutramine to HepG2 and Chang Liver cells was remarkably augmented by inhibition and knockdown of CYP3A4. This study also suggests an inverse relationship between sibutramine cytotoxicity and CYP3A4-mediated metabolism into the N-desmethyl metabolites. - Highlights: • Treatment with sibutramine, an anorexiant, induces endothelial cell apoptosis. • The apoptotic mechanism includes induction of ROS and NO depletion. • There is an inverse relationship between sibutramine cytotoxicity and its metabolism.« less

Esculetin-induced protection of human hepatoma HepG2 cells against hydrogen peroxide is associated with the Nrf2-dependent induction of the NAD(P)H: Quinone oxidoreductase 1 gene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Subramaniam, Sudhakar R.; Ellis, Elizabeth M., E-mail: elizabeth.ellis@strath.ac.uk

Esculetin (6,7-dihydroxy coumarin), is a potent antioxidant that is present in several plant species. The aim of this study was to investigate the mechanism of protection of esculetin in human hepatoma HepG2 cells against reactive oxygen species (ROS) induced by hydrogen peroxide. Cell viability, cell integrity, intracellular glutathione levels, generation of reactive oxygen species and expression of antioxidant enzymes were used as markers to measure cellular oxidative stress and response to ROS. The protective effect of esculetin was compared to a well-characterized chemoprotective compound quercetin. Pre-treatment of HepG2 cells with sub-lethal (10-25 {mu}M) esculetin for 8 h prevented cell deathmore » and maintained cell integrity following exposure to 0.9 mM hydrogen peroxide. An increase in the generation of ROS following hydrogen peroxide treatment was significantly attenuated by 8 h pre-treatment with esculetin. In addition, esculetin ameliorated the decrease in intracellular glutathione caused by hydrogen peroxide exposure. Moreover, treatment with 25 {mu}M esculetin for 8 h increased the expression of NAD(P)H: quinone oxidoreductase (NQO1) at both protein and mRNA levels significantly, by 12-fold and 15-fold, respectively. Esculetin treatment also increased nuclear accumulation of Nrf2 by 8-fold indicating that increased NQO1 expression is Nrf2-mediated. These results indicate that esculetin protects human hepatoma HepG2 cells from hydrogen peroxide induced oxidative injury and that this protection is provided through the induction of protective enzymes as part of an adaptive response mediated by Nrf2 nuclear accumulation.« less

Cytokinin-induced cell death is associated with elevated expression of alternative oxidase in tobacco BY-2 cells.

PubMed

Mlejnek, Petr

2013-10-01

N(6)-benzyladenine (BA) and N(6)-benzyladenosine ([9R]BA) induce massive production of reactive oxygen species (ROS) that is eventually followed by a loss of cell viability in tobacco BY-2 cells (Mlejnek et al. Plant Cell Environ 26:1723-1735, 2003, Plant Sci 168:389-395, 2005). Results presented in this work suggest that the main sources of ROS are likely mitochondria and that the maintenance of the mitochondrial transmembrane potential is crucial for ROS production in cytokinin-treaded BY-2 cells. Therefore, the possible involvement of alternative oxidase (AOX) in cell death process induced by BA and [9R]BA was studied. About three- to fourfold increase in mRNA levels of AOX1 was observed a few hours after the BA and [9R]BA addition into the growth medium. The elevated expression of AOX1 mRNA could be prevented by adding adenine and adenosine which simultaneously reduced the cytotoxic effects of BA and [9R]BA, respectively. N(6)-benzyladenine 7-β-D-glucoside ([7G]BA) which is a common non-toxic metabolite of BA and [9R]BA did not affect the AOX1 mRNA expression. Although AOX1 seemed to be involved in protection of BY-2 cells against the abiotic stress induced by BA and [9R]BA, the results do not support the idea that it protects cells from death exclusively by scavenging of reactive oxygen species. Indeed, N-propyl gallate, an inhibitor of AOX, decreased cell survival despite it concomitantly decreased the ROS production. This finding is in contrast to the effect of salicylhydroxamic acid, another well-known inhibitor of AOX, which also increased the number of dying cells while it increased the ROS production.

Enhanced Reactive Oxygen Species Scavenging by Overproduction of Superoxide Dismutase and Catalase Delays Postharvest Physiological Deterioration of Cassava Storage Roots1[C][W][OA

PubMed Central

Xu, Jia; Duan, Xiaoguang; Yang, Jun; Beeching, John R.; Zhang, Peng

2013-01-01

Postharvest physiological deterioration (PPD) of cassava (Manihot esculenta) storage roots is the result of a rapid oxidative burst, which leads to discoloration of the vascular tissues due to the oxidation of phenolic compounds. In this study, coexpression of the reactive oxygen species (ROS)-scavenging enzymes copper/zinc superoxide dismutase (MeCu/ZnSOD) and catalase (MeCAT1) in transgenic cassava was used to explore the intrinsic relationship between ROS scavenging and PPD occurrence. Transgenic cassava plants integrated with the expression cassette p54::MeCu/ZnSOD-35S::MeCAT1 were confirmed by Southern-blot analysis. The expression of MeCu/ZnSOD and MeCAT1 was verified by quantitative reverse transcription-polymerase chain reaction and enzymatic activity analysis both in the leaves and storage roots. Under exposure to the ROS-generating reagent methyl viologen or to hydrogen peroxide (H2O2), the transgenic plants showed higher enzymatic activities of SOD and CAT than the wild-type plants. Levels of malondialdehyde, chlorophyll degradation, lipid peroxidation, and H2O2 accumulation were dramatically reduced in the transgenic lines compared with the wild type. After harvest, the storage roots of transgenic cassava lines show a delay in their PPD response of at least 10 d, accompanied by less mitochondrial oxidation and H2O2 accumulation, compared with those of the wild type. We hypothesize that this is due to the combined ectopic expression of Cu/ZnSOD and CAT leading to an improved synergistic ROS-scavenging capacity of the roots. Our study not only sheds light on the mechanism of the PPD process but also develops an effective approach for delaying the occurrence of PPD in cassava. PMID:23344905

Enhanced reactive oxygen species scavenging by overproduction of superoxide dismutase and catalase delays postharvest physiological deterioration of cassava storage roots.

PubMed

Xu, Jia; Duan, Xiaoguang; Yang, Jun; Beeching, John R; Zhang, Peng

2013-03-01

Postharvest physiological deterioration (PPD) of cassava (Manihot esculenta) storage roots is the result of a rapid oxidative burst, which leads to discoloration of the vascular tissues due to the oxidation of phenolic compounds. In this study, coexpression of the reactive oxygen species (ROS)-scavenging enzymes copper/zinc superoxide dismutase (MeCu/ZnSOD) and catalase (MeCAT1) in transgenic cassava was used to explore the intrinsic relationship between ROS scavenging and PPD occurrence. Transgenic cassava plants integrated with the expression cassette p54::MeCu/ZnSOD-35S::MeCAT1 were confirmed by Southern-blot analysis. The expression of MeCu/ZnSOD and MeCAT1 was verified by quantitative reverse transcription-polymerase chain reaction and enzymatic activity analysis both in the leaves and storage roots. Under exposure to the ROS-generating reagent methyl viologen or to hydrogen peroxide (H2O2), the transgenic plants showed higher enzymatic activities of SOD and CAT than the wild-type plants. Levels of malondialdehyde, chlorophyll degradation, lipid peroxidation, and H2O2 accumulation were dramatically reduced in the transgenic lines compared with the wild type. After harvest, the storage roots of transgenic cassava lines show a delay in their PPD response of at least 10 d, accompanied by less mitochondrial oxidation and H2O2 accumulation, compared with those of the wild type. We hypothesize that this is due to the combined ectopic expression of Cu/ZnSOD and CAT leading to an improved synergistic ROS-scavenging capacity of the roots. Our study not only sheds light on the mechanism of the PPD process but also develops an effective approach for delaying the occurrence of PPD in cassava.

Glucocorticoid Signaling and Bone Biology.

PubMed

Komori, T

2016-11-01

Since glucocorticoids remain an effective therapeutic option for the treatment of many inflammatory and autoimmune diseases, glucocorticoid-induced osteoporosis is the most common form of secondary osteoporosis. Fractures may occur in as many as 30-50% of patients receiving chronic glucocorticoid therapy. Under physiological conditions, glucocorticoids are required for normal bone development due to their regulation of osteoblast differentiation, possibly via the Wnt/β-catenin pathway and TSC22D3. However, serum levels of endogenous corticosterone are elevated in aged mice and glucocorticoids exert negative effects on the survival of osteoblasts and osteocytes as well as angiogenesis. Glucocorticoid treatments impair bone formation and enhance bone resorption. Excess glucocorticoids induce osteoblast and osteocyte apoptosis by increasing pro-apoptotic molecules, reactive oxygen species, and endoplasmic reticulum stress and suppressing the Wnt/β-catenin pathway. Autophagy protects osteocytes from glucocorticoid-induced apoptosis, but passed some threshold, the process of autophagy leads the cells to apoptosis. Excess glucocorticoids impair osteoblastogenesis by inducing Wnt antagonists, including Dkk1, Sost, and sFRP-1. However, the findings are controversial and the involvement of Wnt antagonists requires further study. Excess glucocorticoids reduce the phosphorylation of Akt and GSK3β, which enhances the degradation of β-catenin. Excess glucocorticoids have been shown to modulate the expression of miRNAs, including miR-29a, miR-34a-5p, and miR-199a-5p, which regulate the proliferation and differentiation of osteoblast lineage cells. Excess glucocorticoids also enhance bone resorption by reducing OPG expression, increasing Rankl expression and reactive oxygen species, and prolonging the life span of osteoclasts; however, they also suppress the bone-degrading capacity of osteoclasts by disturbing the organization of the cytoskeleton. © Georg Thieme Verlag KG Stuttgart · New York.

Butein induction of HO-1 by p38 MAPK/Nrf2 pathway in adipocytes attenuates high-fat diet induced adipose hypertrophy in mice.

PubMed

Wang, Zheng; Ka, Sun-O; Lee, Youngyi; Park, Byung-Hyun; Bae, Eun Ju

2017-03-15

Adipose tissue inflammation and oxidative stress are key components in the development of obesity and insulin resistance. Heme oxygenase (HO)-1 in adipocytes protects against obesity and adipose dysfunction. In this study, we report the identification of butein, a flavonoid chalcone, as a novel inducer of HO-1 expression in adipocytes in vitro and in vivo. Butein upregulated HO-1 mRNA and protein expression in 3T3-L1 adipocytes, accompanied by Kelch-Like ECH-Associated Protein (Keap) 1 degradation and increase in the nuclear level of nuclear factor erythroid 2-related factor 2 (Nrf2). Butein modulation of Keap1 and Nrf2 as well as HO-1 upregulation was reversed by pretreatment with p38 MAPK inhibitor SB203580, indicating the involvement of p38 MAPK in butein activation of Nrf2 in adipocytes. In addition, HO-1 activation by butein led to the inhibitions of reactive oxygen species and adipocyte differentiation, as evidenced by the fact that butein repression of reactive oxygen species and adipogenesis was reversed by pretreatment with HO-1 inhibitor SnPP. Induction of HO-1 expression by butein was also demonstrated in the adipose tissue of C57BL/6 mice fed a high-fat diet administered along with butein for three weeks, and correlated with the inhibitions of adiposity and adipose tissue inflammation, which were reversed by co-administration of SnPP. Altogether, our results demonstrate that butein activates the p38 MAPK/Nrf2/HO-1 pathway to act as a potent inhibitor of adipose hypertrophy and inflammation in a diet-induced obesity model and thus has potential for suppressing obesity-linked metabolic syndrome. Copyright © 2017 Elsevier B.V. All rights reserved.

Curcumin interacts with sildenafil to kill GI tumor cells via endoplasmic reticulum stress and reactive oxygen/ nitrogen species

PubMed Central

Roberts, Jane L.; Poklepovic, Andrew; Booth, Laurence

2017-01-01

The present studies focused on the ability of the phosphodiesterase 5 (PDE5) inhibitor sildenafil to enhance the anti-cancer properties of clinically relevant concentrations of the dietary diarylheptanoid curcumin. In gastrointestinal tumor cells, sildenafil and curcumin interacted in a greater than additive fashion to kill. Inhibition of the extrinsic apoptotic pathway suppressed killing by ∼50%, as did blockade of the intrinsic apoptotic pathway. Sildenafil and curcumin reduced mTORC1 and mTORC2 activity and increased Beclin1 levels and the numbers of autophagosomes and autolysosomes in cells in a PERK-eIF2α-dependent fashion. Knock down of Beclin1 or ATG5 partially suppressed killing. In contrast, stable knock out of ATG16-L1 unexpectedly enhanced killing, an effect not altered by Beclin1/ATG5 knock down. Curcumin and sildenafil exposure reduced the expression of MCL-1, BCL-XL, thioredoxin and superoxide dismutase 2 (SOD2) in an eIF2α-dependent fashion. Curcumin and sildenafil interacted in a greater than additive fashion to increase the levels of reactive oxygen species; knock down of thioredoxin or SOD2 enhanced killing and over-expression of thioredoxin or SOD2 suppressed killing. In vivo, curcumin and sildenafil interacted to suppress the growth of colon cancer tumors. Multiplex analyses of plasma taken after drug exposure at animal nadir indicated that the levels of M-CSF, CXCL-9, PDGF and G-CSF were significantly increased by [curcumin + sildenafil] and that expression of CXCL1 and CCL5 were significantly reduced. Cells isolated from in vivo treated [curcumin + sildenafil] tumors were resistant to in vitro [curcumin + sildenafil] exposure, a phenotype that was blocked by the colon cancer therapeutic regorafenib. PMID:29245915

Cytosolic Calcium, hydrogen peroxide, and related gene expression and protein modulation in Arabidopsis thaliana cell cultures respond immediately to altered gravitation: Parabolic flight data

NASA Astrophysics Data System (ADS)

Hampp, Ruediger; Hausmann, Niklas; Neef, Maren; Fengler, Svenja

Callus cell cultures of Arabidopsis thaliana (cv. Columbia) were exposed to parabolic flights in order to assess molecular short-term responses to altered gravity fields. Using transgenic cell lines, hydrogen peroxide and cytosolic Ca2+ were continuously monitored. In parallel, the metabolism of samples was chemically quenched (RNAlater, Ambion, for RNA; acid/base for NADPH, NADP) at typical stages of a parabola (1g before pull up; end of pull up (1.8 g), end of microgravity (µg, 20 sec), and end of pull out (1.8 g)). Cells exhibited an increase of both Ca2+ and hydrogen peroxide with the onset of µg, and a decline thereafter. This behaviour was accompanied by a decrease of the NADPH/NADP redox ratio, indicating a Ca2+-dependent activation of a NADPH oxidase. Microarray analyses revealed concomitant expression profiles. At the end of the microgravity phase, 396 transcripts were specifically up-, while 485 were down-regulated. Up-regulation was dominated by Ca2+- and ROS(reactive oxygen species)-related gene products. The same material was also used for the analysis of phosphopeptides by 2D SDS PAGE. Relevant spots were identified by liquid chromatography-MS. With the exception of a chaperone (HSP 70-3), hypergravity (1.8 g) and microgravity modified different sets of proteins. These are partly involved in primary metabolism (glycolysis, gluconeogenesis, citrate cycle) and detoxification of reactive oxygen species. Taken together, these data show that both gene expression and protein modulation jointly respond within seconds to alterations in the gravity field, with a focus on metabolic adaptation, signalling and control of ROS.

Antihyperglycemic drug Gymnema sylvestre also shows anticancer potentials in human melanoma A375 cells via reactive oxygen species generation and mitochondria-dependent caspase pathway.

PubMed

Chakraborty, Debrup; Ghosh, Samrat; Bishayee, Kausik; Mukherjee, Avinaba; Sikdar, Sourav; Khuda-Bukhsh, Anisur Rahman

2013-09-01

Ethanolic extract of Gymnema sylvestre (GS) leaves is used as a potent antidiabetic drug in various systems of alternative medicine, including homeopathy. The present study was aimed at examining if GS also had anticancer potentials, and if it had, to elucidate its possible mechanism of action. We initially tested possible anticancer potential of GS on A375 cells (human skin melanoma) through MTT assay and determined cytotoxicity levels in A375 and normal liver cells; we then thoroughly studied its apoptotic effects on A375 cells through protocols such as Hoechst 33258, H2DCFDA, and rhodamine 123 staining and conducted ELISA for cytochrome c, caspase 3, and PARP activity levels; we determined the mRNA level expression of cytochrome c, caspase 3, Bcl2, Bax, PARP, ICAD, and EGFR signaling genes through semiquantitative reverse transcriptase polymerase chain reaction and conducted Western blot analysis of caspase 3 and PARP. We also analyzed cell cycle events, determined reactive oxygen species accumulation, measured annexin V-FITC/PI and rhodamine 123 intensity by flow cytometry. Compared with both normal liver cells and drug-untreated A375, the mortality of GS-treated A375 cells increased in a dose-dependent manner. Additionally, GS induced nuclear DNA fragmentation and showed an increased level of mRNA expression of apoptotic signal related genes cytochrome c, caspase 3, PARP, Bax, and reduced expression level of ICAD, EGFR, and the anti-apoptotic gene Bcl2. Overall results indicate GS to have significant anticancer effect on A375 cells apart from its reported antidiabetic effect, indicating possibility of its palliative use in patients with symptoms of both the diseases.

A role for nuclear translocation of tripeptidyl-peptidase II in reactive oxygen species-dependent DNA damage responses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Preta, Giulio; Klark, Rainier de; Glas, Rickard, E-mail: rickard.glas@ki.se

2009-11-27

Responses to DNA damage are influenced by cellular metabolism through the continuous production of reactive oxygen species (ROS), of which most are by-products of mitochondrial respiration. ROS have a strong influence on signaling pathways during responses to DNA damage, by relatively unclear mechanisms. Previous reports have shown conflicting data on a possible role for tripeptidyl-peptidase II (TPPII), a large cytosolic peptidase, within the DNA damage response. Here we show that TPPII translocated into the nucleus in a p160-ROCK-dependent fashion in response to {gamma}-irradiation, and that nuclear expression of TPPII was present in most {gamma}-irradiated transformed cell lines. We used amore » panel of nine cell lines of diverse tissue origin, including four lymphoma cell lines (T, B and Hodgkins lymphoma), a melanoma, a sarcoma, a colon and two breast carcinomas, where seven out of nine cell lines showed nuclear TPPII expression after {gamma}-irradiation. Further, this required cellular production of ROS; treatment with either N-acetyl-Cysteine (anti-oxidant) or Rotenone (inhibitor of mitochondrial respiration) inhibited nuclear accumulation of TPPII. The local density of cells was important for nuclear accumulation of TPPII at early time-points following {gamma}-irradiation (at 1-4 h), indicating a bystander effect. Further, we showed that the peptide-based inhibitor Z-Gly-Leu-Ala-OH, but not its analogue Z-Gly-(D)-Leu-Ala-OH, excluded TPPII from the nucleus. This correlated with reduced nuclear expression of p53 as well as caspase-3 and -9 activation in {gamma}-irradiated lymphoma cells. Our data suggest a role for TPPII in ROS-dependent DNA damage responses, through alteration of its localization from the cytosol into the nucleus.« less

A role for nuclear translocation of tripeptidyl-peptidase II in reactive oxygen species-dependent DNA damage responses.

PubMed

Preta, Giulio; de Klark, Rainier; Glas, Rickard

2009-11-27

Responses to DNA damage are influenced by cellular metabolism through the continuous production of reactive oxygen species (ROS), of which most are by-products of mitochondrial respiration. ROS have a strong influence on signaling pathways during responses to DNA damage, by relatively unclear mechanisms. Previous reports have shown conflicting data on a possible role for tripeptidyl-peptidase II (TPPII), a large cytosolic peptidase, within the DNA damage response. Here we show that TPPII translocated into the nucleus in a p160-ROCK-dependent fashion in response to gamma-irradiation, and that nuclear expression of TPPII was present in most gamma-irradiated transformed cell lines. We used a panel of nine cell lines of diverse tissue origin, including four lymphoma cell lines (T, B and Hodgkins lymphoma), a melanoma, a sarcoma, a colon and two breast carcinomas, where seven out of nine cell lines showed nuclear TPPII expression after gamma-irradiation. Further, this required cellular production of ROS; treatment with either N-acetyl-Cysteine (anti-oxidant) or Rotenone (inhibitor of mitochondrial respiration) inhibited nuclear accumulation of TPPII. The local density of cells was important for nuclear accumulation of TPPII at early time-points following gamma-irradiation (at 1-4h), indicating a bystander effect. Further, we showed that the peptide-based inhibitor Z-Gly-Leu-Ala-OH, but not its analogue Z-Gly-(D)-Leu-Ala-OH, excluded TPPII from the nucleus. This correlated with reduced nuclear expression of p53 as well as caspase-3 and -9 activation in gamma-irradiated lymphoma cells. Our data suggest a role for TPPII in ROS-dependent DNA damage responses, through alteration of its localization from the cytosol into the nucleus.

Regulation of H2O2 Stress-responsive Genes through a Novel Transcription Factor in the Protozoan Pathogen Entamoeba histolytica*

PubMed Central

Pearson, Richard J.; Morf, Laura; Singh, Upinder

2013-01-01

Outcome of infection depends upon complex interactions between the invading pathogen and the host. As part of the host's innate immune response, the release of reactive oxygen and nitrogen species by phagocytes represents a major obstacle to the establishment of infection. The ability of the human parasite Entamoeba histolytica to survive reactive oxygen and nitrogen species is central to its pathogenic potential and contributes to disease outcome. In order to define the transcriptional network associated with oxidative stress, we utilized the MEME and MAST programs to analyze the promoter regions of 57 amoebic genes that had increased expression specifically in response to H2O2 exposure. We functionally characterized an H2O2-regulatory motif (HRM) (1AAACCTCAATGAAGA15), which was enriched in these promoters and specifically bound amoebic nuclear protein(s). Assays with promoter-luciferase fusions established the importance of key residues and that the HRM motif directly impacted the ability of H2O2-responsive promoters to drive gene expression. DNA affinity chromatography and mass spectrometry identified EHI_108720 as an HRM DNA-binding protein. Overexpression and down-regulation of EHI_108720 demonstrated the specificity of EHI_108720 protein binding to the HRM, and overexpression increased basal expression from an H2O2-responsive wild-type promoter but not from its mutant counterpart. Thus, EHI_108720, or HRM-binding protein, represents a new stress-responsive transcription factor in E. histolytica that controls a transcriptional regulatory network associated with oxidative stress. Overexpression of EHI_108720 increased parasite virulence. Insight into how E. histolytica responds to oxidative stress increases our understanding of how this important human pathogen establishes invasive disease. PMID:23250742

Paclitaxel-resistant HeLa cells have up-regulated levels of reactive oxygen species and increased expression of taxol resistance gene 1.

PubMed

Bi, Wenxiang; Wang, Yuxia; Sun, Gaoying; Zhang, Xiaojin; Wei, Yongqing; Li, Lu; Wang, Xiaoyuan

2014-07-01

This study is to establish a paclitaxel (PTX)-resistant human cervical carcinoma HeLa cell line (HeLa/PTX) and to investigate its redox characteristics and the expression of taxol resistance gene 1 (Txr1). HeLa cells were treated with PTX and effects of PTX on cell proliferation were detected through cell counting and the MTT assay. Levels of cellular reactive oxygen species (ROS), reduced glutathione (GSH), and oxidized glutathione (GSSG) as well as the ratio of GSH to GSSG were measured by the 2,7-difluorescein diacetate (DCFH-DA) method and the 5,5'dithiobis(2-nitrobenzoic acid) (DTNB) method. Activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were determined by the nitrite formation method, the molybdate colorimetric method, and the DTNB colorimetric method, respectively. The level of Txr1 mRNA was determined by real-time PCR. Compared with the regular HeLa cells, HeLa/PTX cells were larger in size and had more cytoplasmic granules. The population doubling time for HeLa/PTX cells was 1.32 times of that of HeLa cells (P<0.01). HeLa/PTX cells showed stronger resistance to PTX than HeLa cells with a resistance index of 122.69. HeLa/PTX cells had higher levels of ROS (P<0.01) and Txr1 mRNA (P<0.01), lower level of GSH (P < 0.05), and lower activities of SOD (P<0.01) and GPx (P < 0.05) than HeLa cells. HeLa/PTX cells, with higher levels of ROS and Txr1 mRNA expression, are more resistant to PTX than HeLa cells.

Role of NADP+-dependent isocitrate dehydrogenase (NADP+-ICDH) on cellular defence against oxidative injury by gamma-rays.

PubMed

Lee, S H; Jo, S H; Lee, S M; Koh, H J; Song, H; Park, J W; Lee, W H; Huh, T L

2004-09-01

To investigate the regulation of NADPH-producing isocitrate dehydrogenase (ICDH) in cytosol (IDPc) and mitochondria (IDPm) upon gamma-ray irradiation, and the roles of IDPc and IDPm in the protection against cellular damage induced by gamma-ray irradiation. Changes of IDPc and IDPm proteins upon gamma-ray irradiation to NIH3T3 cells were analysed by immunoblotting. To increase or decrease the expression of IDPc or IDPm, NIH3T3 cells were stably transfected with mouse IDPc or IDPm cDNA in either the sense or the antisense direction. The transfected cells with either increased or decreased IDPc or IDPm were exposed to gamma-rays, and the levels of reactive oxygen species generation, protein oxidation and lipid peroxidation were measured. Both IDPc and IDPm activities were induced by gamma-ray in NIH3T3 cells. Cells with decreased expression of IDPc or IDPm had elevated reactive oxygen species generation, lipid peroxidation and protein oxidation. Conversely, overproduction of IDPc or IDPm protein partially protected the cells from oxidative damage induced by gamma-ray irradiation. The protective role of IDPc and IDPm against gamma-ray-induced cellular damage can be attributed to elevated NADPH, reducing equivalents needed for recycling reduced glutathione in the cytosol and mitochondria. Thus, a primary biological function of the ICDHs may be production of NADPH, which is a prerequisite for some cellular defence systems against oxidative damage.

Opposite effects of statins on mitochondria of cardiac and skeletal muscles: a ‘mitohormesis’ mechanism involving reactive oxygen species and PGC-1

PubMed Central

Bouitbir, Jamal; Charles, Anne-Laure; Echaniz-Laguna, Andoni; Kindo, Michel; Daussin, Frédéric; Auwerx, Johan; Piquard, François; Geny, Bernard; Zoll, Joffrey

2012-01-01

Aims Statins protect against cardiovascular-related mortality but induce skeletal muscle toxicity. To investigate mechanisms of statins, we tested the hypothesis that statins optimized cardiac mitochondrial function but impaired vulnerable skeletal muscle by inducing different level of reactive oxygen species (ROS). Methods and results In atrium of patients treated with statins, ROS production was decreased and oxidative capacities were enhanced together with an extensive augmentation of mRNAs expression of peroxisome proliferator-activated receptor gamma co-activator (PGC-1) family. However, in deltoid biopsies from patients with statin-induced muscular myopathy, oxidative capacities were decreased together with ROS increase and a collapse of PGC-1 mRNA expression. Several animal and cell culture experiments were conducted and showed by using ROS scavengers that ROS production was the triggering factor responsible of atorvastatin-induced activation of mitochondrial biogenesis pathway and improvement of antioxidant capacities in heart. Conversely, in skeletal muscle, the large augmentation of ROS production following treatment induced mitochondrial impairments, and reduced mitochondrial biogenesis mechanisms. Quercetin, an antioxidant molecule, was able to counteract skeletal muscle deleterious effects of atorvastatin in rat. Conclusion Our findings identify statins as a new activating factor of cardiac mitochondrial biogenesis and antioxidant capacities, and suggest the importance of ROS/PGC-1 signalling pathway as a key element in regulation of mitochondrial function in cardiac as well as skeletal muscles. PMID:21775390

Docosahexaenoic acid induces ERK1/2 activation and neuritogenesis via intracellular reactive oxygen species production in human neuroblastoma SH-SY5Y cells.

PubMed

Wu, Haitao; Ichikawa, Sanae; Tani, Chiharu; Zhu, Beiwei; Tada, Mikiro; Shimoishi, Yasuaki; Murata, Yoshiyuki; Nakamura, Yoshimasa

2009-01-01

Docosahexaenoic acid (22: 6n-3; DHA) is a long chain polyunsaturated fatty acid that exists highly enriched in fish oil, and it is one of the low molecular weight food chemicals which can pass a blood brain barrier. A preliminary survey of several fatty acids for expression of growth-associated protein-43 (GAP-43), a marker of axonal growth, identified DHA as one of the most potent inducers. The human neuroblastoma SH-SY5Y cells exposed to DHA showed significant and dose-dependent increases in the percentage of cells with longer neurites. To elucidate signaling mechanisms involved in DHA-enhanced basal neuritogenesis, we examined the role of extracellular signal-regulated kinase (ERK)1/2 and intracellular reactive oxygen species (ROS) production using SH-SY5Y cells. From immunoblotting experiments, we observed that DHA induced the ROS production, protein tyrosine phosphatase inhibition, mitogen-activated protein kinase (MAPK)/ERK kinase (MEK) phosphorylation, and sequentially ERK1/2 phosphorylation, the last of which was significantly reduced by MEK inhibitor U0126. Both antioxidants and MEK inhibitor affected DHA-induced GAP-43 expression, whereas the specific PI3K inhibitor LY294002 did not. We found that total protein tyrosine phosphatase activity was also downregulated by DHA treatment, which was counteracted by antioxidant pretreatment. These results suggest that the ROS-dependent ERK pathway, rather than PI3K, plays an important role during DHA-enhanced neurite outgrowth.

Nickel-induced Epithelial-Mesenchymal Transition by Reactive Oxygen Species Generation and E-cadherin Promoter Hypermethylation*

PubMed Central

Wu, Chih-Hsien; Tang, Sheau-Chung; Wang, Po-Hui; Lee, Huei; Ko, Jiunn-Liang

2012-01-01

Epithelial-mesenchymal transition (EMT) is considered a critical event in the pathogenesis of lung fibrosis and tumor metastasis. During EMT, the expression of differentiation markers switches from cell-cell junction proteins such as E-cadherin to mesenchymal markers such as fibronectin. Although nickel-containing compounds have been shown to be associated with lung carcinogenesis, the role of nickel in the EMT process in bronchial epithelial cells is not clear. The aim of this study was to examine whether nickel contributes to EMT in human bronchial epithelial cells. We also attempted to clarify the mechanisms involved in NiCl2-induced EMT. Our results showed that NiCl2 induced EMT phenotype marker alterations such as up-regulation of fibronectin and down-regulation of E-cadherin. In addition, the potent antioxidant N-acetylcysteine blocked EMT and expression of HIF-1α induced by NiCl2, whereas the DNA methyltransferase inhibitor 5-aza-2′-deoxycytidine restored the down-regulation of E-cadherin induced by NiCl2. Promoter hypermethylation of E-cadherin, determined by quantitative real time methyl-specific PCR and bisulfate sequencing, was also induced by NiCl2. These results shed new light on the contribution of NiCl2 to carcinogenesis. Specifically, NiCl2 induces down-regulation of E-cadherin by reactive oxygen species generation and promoter hypermethylation. This study demonstrates for the first time that nickel induces EMT in bronchial epithelial cells. PMID:22648416

Nitric oxide synthase and oxidative-nitrosative stress play a key role in placental infection by Trypanosoma cruzi.

PubMed

Triquell, María Fernanda; Díaz-Luján, Cintia; Romanini, María Cristina; Ramirez, Juan Carlos; Paglini-Oliva, Patricia; Schijman, Alejandro Gabriel; Fretes, Ricardo Emilio

2018-03-25

The innate immune response of the placenta may participate in the congenital transmission of Chagas disease through releasing reactive oxygen and nitrogen intermediates. Placental explants were cultured with 1 × 10 6 and 1 × 10 5 trypomastigotes of Tulahuen and Lucky strains and controls without parasites, and with the addition of nitric oxide synthase inhibitor Nω-Nitro-l-arginine methyl ester (l-NAME) and N-acetyl cysteine (NAC) as the reactive oxygen species (ROS) scavenger. Detachment of the syncytiotrophoblast (STB) was examined by histological analysis, and the nitric oxide synthase, endothelial (eNOS), and nitrotyrosine expressions were analyzed by immunohistochemistry, as well as the human chorionic gonadotrophin (hCG) levels in the culture supernatant through ELISA assays. Parasite load with qPCR using Taqman primers was quantified. The higher number of T. cruzi (10 6 ) increased placental infection, eNOS expression, nitrosative stress, and STB detachment, with the placental barrier being injured by oxidative stress. The higher number of parasites caused deleterious consequences to the placental barrier, and the inhibitors (l-NAME and NAC) prevented the damage caused by trypomastigotes in placental villi but not that of the infection. Moreover, trophoblast eNOS played a key role in placental infection with the highest inoculum of Lucky, demonstrating the importance of the enzyme and nitrosative-oxidative stress in Chagas congenital transmission. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

SALT-RESPONSIVE ERF1 Regulates Reactive Oxygen Species–Dependent Signaling during the Initial Response to Salt Stress in Rice[W

PubMed Central

Schmidt, Romy; Mieulet, Delphine; Hubberten, Hans-Michael; Obata, Toshihiro; Hoefgen, Rainer; Fernie, Alisdair R.; Fisahn, Joachim; San Segundo, Blanca; Guiderdoni, Emmanuel; Schippers, Jos H.M.; Mueller-Roeber, Bernd

2013-01-01

Early detection of salt stress is vital for plant survival and growth. Still, the molecular processes controlling early salt stress perception and signaling are not fully understood. Here, we identified SALT-RESPONSIVE ERF1 (SERF1), a rice (Oryza sativa) transcription factor (TF) gene that shows a root-specific induction upon salt and hydrogen peroxide (H2O2) treatment. Loss of SERF1 impairs the salt-inducible expression of genes encoding members of a mitogen-activated protein kinase (MAPK) cascade and salt tolerance–mediating TFs. Furthermore, we show that SERF1-dependent genes are H2O2 responsive and demonstrate that SERF1 binds to the promoters of MAPK KINASE KINASE6 (MAP3K6), MAPK5, DEHYDRATION-RESPONSIVE ELEMENT BINDING2A (DREB2A), and ZINC FINGER PROTEIN179 (ZFP179) in vitro and in vivo. SERF1 also directly induces its own gene expression. In addition, SERF1 is a phosphorylation target of MAPK5, resulting in enhanced transcriptional activity of SERF1 toward its direct target genes. In agreement, plants deficient for SERF1 are more sensitive to salt stress compared with the wild type, while constitutive overexpression of SERF1 improves salinity tolerance. We propose that SERF1 amplifies the reactive oxygen species–activated MAPK cascade signal during the initial phase of salt stress and translates the salt-induced signal into an appropriate expressional response resulting in salt tolerance. PMID:23800963

The RING finger E3 ligase STRF1 is involved in membrane trafficking and modulates salt-stress response in Arabidopsis thaliana.

PubMed

Tian, Miaomiao; Lou, Lijuan; Liu, Lijing; Yu, Feifei; Zhao, Qingzhen; Zhang, Huawei; Wu, Yaorong; Tang, Sanyuan; Xia, Ran; Zhu, Baoge; Serino, Giovanna; Xie, Qi

2015-04-01

Salt stress is a detrimental factor for plant growth and development. The response to salt stress has been shown to involve components in the intracellular trafficking system, as well as components of the ubiquitin-proteasome system (UPS). In this article, we have identified in Arabidopsis thaliana a little reported ubiquitin ligase involved in salt-stress response, which we named STRF1 (Salt Tolerance RING Finger 1). STRF1 is a member of RING-H2 finger proteins and we demonstrate that it has ubiquitin ligase activity in vitro. We also show that STRF1 localizes mainly at the plasma membrane and at the intracellular endosomes. strf1-1 loss-of-function mutant seedlings exhibit accelerated endocytosis in roots, and have altered expression of several genes involved in the membrane trafficking system. Moreover, protein trafficking inhibitor, brefeldin A (BFA), treatment has increased BFA bodies in strf1-1 mutant. This mutant also showed increased tolerance to salt, ionic and osmotic stresses, reduced accumulation of reactive oxygen species during salt stress, and increased expression of AtRbohD, which encodes a nicotinamide adenine dinucleotide phosphate (NADPH) oxidase involved in H2 O2 production. We conclude that STRF1 is a membrane trafficking-related ubiquitin ligase, which helps the plant to respond to salt stress by monitoring intracellular membrane trafficking and reactive oxygen species (ROS) production. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

Cortisol Induces Reactive Oxygen Species Through a Membrane Glucocorticoid Receptor in Rainbow Trout Myotubes.

PubMed

Espinoza, Marlen B; Aedo, Jorge E; Zuloaga, Rodrigo; Valenzuela, Cristian; Molina, Alfredo; Valdés, Juan A

2017-04-01

Cortisol is an essential regulator of neuroendocrine stress responses in teleosts. Cortisol predominantly affects target tissues through the genomic pathway, which involves interacting with cytoplasmic glucocorticoid receptors, and thereby, modulating stress-response gene expressions. Cortisol also produces rapid effects via non-genomic pathways, which do not involve gene transcription. Although cortisol-mediated genomic pathways are well documented in teleosts, non-genomic pathways are not fully understood. Moreover, no studies have focused on the contribution of non-genomic cortisol pathways in compensatory stress responses in fish. In this study, rainbow trout (Oncorhynchus mykiss) skeletal myotubes were stimulated with physiological concentrations of cortisol and cortisol-BSA, a membrane-impermeable agent, resulting in an early induction of reactive oxygen species (ROS). This production was not suppressed by transcription or translation inhibitors, suggesting non-genomic pathway involvement. Moreover, myotube preincubation with RU486 and NAC completely suppressed cortisol- and cortisol-BSA-induced ROS production. Subcellular fractionation analysis revealed the presence of cell membrane glucocorticoid receptors. Finally, cortisol-BSA induced a significant increase in ERK1/2 and CREB phosphorylation, as well as in CREB-dependent transcriptional activation of the pgc1a gene expression. The obtained results strongly suggest that cortisol acts through a non-genomic glucocorticoid receptor-mediated pathway to induce ROS production and contribute to ERK/CREB/PGC1-α signaling pathway activation as stress compensation mechanisms. J. Cell. Biochem. 118: 718-725, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Temperature stress effects in Bemisia tabaci (Hemiptera: Aleyrodidae) type B whiteflies

USDA-ARS?s Scientific Manuscript database

Oxidative stress occurs in response to changes in the redox equilibiurm, which may be caused by increases in reactive oxygen species (ROS), a decrease in antioxidant protection or failure of cells to repair oxidative damage. ROS are either free radicals, reactive molecules containing oxygen atoms or...

Response of the ascorbate-glutathione cycle to storage temperature in carambola fruit

USDA-ARS?s Scientific Manuscript database

The generation of reactive oxygen species (ROS) is considered to be a primary event under a variety of stress conditions. It has been generally accepted that reactive oxygen produced under stress is a detrimental factor, which causes lipid peroxidation, enzyme inactivation, and oxidative damage to D...

Eicosanoids up-regulate production of reactive oxygen species by NADPH-dependent oxidase in Spodoptera exigua phagocytic hemocytes

USDA-ARS?s Scientific Manuscript database

Eicosanoids mediate cellular immune responses in insects, including phagocytosis of invading microbes. Phagocytosis entails two major steps, the internalization of microbes and the subsequent killing of them via formation of reactive oxygen species (ROS). Here, we posed the hypothesis that eicosanoi...

An innovative coupling between column leaching and oxygen consumption tests to assess behavior of contaminated marine dredged sediments.

PubMed

Couvidat, Julien; Benzaazoua, Mostafa; Chatain, Vincent; Zhang, Fan; Bouzahzah, Hassan

2015-07-01

Contaminated dredged sediments are often considered hazardous wastes, so they have to be adequately managed to avoid leaching of pollutants. The mobility of inorganic contaminants is a major concern. Metal sulfides (mainly framboïdal pyrite, copper, and zinc sulfides) have been investigated in this study as an important reactive metal-bearing phase sensitive to atmospheric oxygen action. An oxygen consumption test (OC-Test) has been adapted to assess the reactivity of dredged sediments when exposed to atmospheric oxygen. An experimental column set-up has been developed allowing the coupling between leaching and oxygen consumption test to investigate the reactivity of the sediment. This reactivity, which consisted of sulfide oxidation, was found to occur for saturation degree between 60 and 90 % and until the 20th testing week, through significant sulfates releases. These latter were assumed to come from sulfide oxidation in the first step of the test, then probably from gypsum dissolution. Confrontation results of OC-Test and leachate quality shows that Cu was well correlated to sulfates releases, which in turn, leads to Ca and Mg dissolution (buffer effect). Cu, and mostly Zn, was associated to organic matter, phyllosilicates, and other minerals through organo-clay complexes. This research confirmed that the OC-Test, originally developed for mine tailings, could be a useful tool in the dredged sediment field which can allow for intrinsic characterization of reactivity of a material suspected to readily reacting with oxygen and for better understanding of geochemical processes that affect pollutants behavior, conversion, and transfer in the environment.

Quercetin Feeding in Newborn Dairy Calves Cannot Compensate Colostrum Deprivation: Study on Metabolic, Antioxidative and Inflammatory Traits

PubMed Central

Gruse, Jeannine; Kanitz, Ellen; Weitzel, Joachim M.; Tuchscherer, Armin; Stefaniak, Tadeusz; Jawor, Paulina; Wolffram, Siegfried; Hammon, Harald M.

2016-01-01

Immaturity of the neonatal immune system is causative for high morbidity in calves and colostrum intake is crucial for acquiring passive immunity. Pathogenesis is promoted by reactive oxygen species accumulating at birth if counter-regulation is inadequate. The flavonol quercetin exerts antioxidative and anti-inflammatory effects that may enhance neonatal health. The aim of this work was to study effects of quercetin feeding on metabolic, antioxidative and inflammatory parameters in neonatal calves to investigate whether quercetin could compensate for insufficient colostrum supply. Twenty-eight newborn calves were assigned to two dietary groups fed colostrum or milk-based formula on day 1 and 2 and milk replacer thereafter. From day 2 onwards, 7 calves per diet group were additionally fed quercetin aglycone (50 mg/(kg body weight × day)). Blood samples were taken repeatedly to measure plasma concentrations of flavonols, glucose, lactate, total protein, albumin, urea, non-esterified fatty acids, triglycerides, cholesterol, insulin, glucagon, cortisol, immunoglobulins, fibrinogen, haptoglobin and serum amyloid A. Trolox equivalent antioxidative capacity, ferric reducing ability of plasma, thiobarbituric acid reactive species and F2-isoprostanes were analyzed to evaluate plasma antioxidative status. Expression of tumor necrosis factor, interleukin-1α, interleukin-1β, serum amyloid A, haptoglobin, fibrinogen, C-reactive protein, catalase, glutathione peroxidase and superoxide dismutase mRNA were measured in liver tissue on day 8. Plasma flavonol concentrations were detectable only after quercetin-feeding without differences between colostrum and formula feeding. Plasma glucose, lactate, total protein, immunoglobulins, triglycerides, cholesterol, trolox equivalent antioxidative capacity and thiobarbituric acid reactive species were higher after colostrum feeding. Body temperature, fecal fluidity and plasma concentrations of cortisol and haptoglobin were higher in formula- than in colostrum-fed groups. Hepatic mRNA expression of tumor necrosis factor was higher after quercetin feeding and expression of C-reactive protein was higher after formula feeding. Data confirm that colostrum improves neonatal health and indicate that quercetin feeding cannot compensate for insufficient colostrum supply. PMID:26752173

Hyperactivity and reactivity of peripheral blood neutrophils in chronic periodontitis

PubMed Central

Matthews, J B; Wright, H J; Roberts, A; Cooper, P R; Chapple, I L C

2007-01-01

Some evidence exists that peripheral neutrophils from patients with chronic periodontitis generate higher levels of reactive oxygen species (ROS) after Fcγ-receptor stimulation than those from healthy controls. We hypothesized that peripheral neutrophils in periodontitis also show both hyper-reactivity to plaque organisms and hyperactivity in terms of baseline, unstimulated generation and release of ROS. Peripheral neutrophils from chronic periodontitis patients and age/sex/smoking-matched healthy controls (18 pairs) were assayed for total ROS generation and extracellular ROS release, with and without stimulation (Fcγ-receptor and Fusobacterium nucleatum), using luminol and isoluminol chemiluminescence. Assays were performed with and without priming with Escherichia coli lipopolysaccharide (LPS) and granulocyte–macrophage colony-stimulating factor (GM-CSF). Phox gene expression (p22, p47, p67, gp91) was investigated using reverse transcription–polymerase chain reaction (RT–PCR). Neutrophils from patients produced higher mean levels of ROS in all assays. Total generation and extracellular release of ROS by patients' cells were significantly greater than those from controls after FcγR-stimulation, with (P = 0·023) and without (P ≤ 0·023) priming with GM-CSF. Differences in unstimulated total ROS generation were not significant. By contrast, patients' cells demonstrated greater baseline, extracellular ROS release than those from controls (P = 0·004). This difference was maintained after priming with LPS (P = 0·028) but not GM-CSF (P = 0·217). Phox gene expression was similar in patient and control cells at baseline and stimulation with F. nucleatum (3 h) consistently reduced gp91PHOX transcripts. Our data demonstrate that peripheral neutrophils from periodontitis patients exhibit hyper-reactivity following stimulation (Fcγ-receptor and F. nucleatum) and hyperactivity in terms of excess ROS release in the absence of exogenous stimulation. This hyperactive/-reactive neutrophil phenotype is not associated with elevated phox gene expression. PMID:17223966

A study of the oxygen dynamics in a reactive Ar/O2 high power impulse magnetron sputtering discharge using an ionization region model

NASA Astrophysics Data System (ADS)

Lundin, D.; Gudmundsson, J. T.; Brenning, N.; Raadu, M. A.; Minea, T. M.

2017-05-01

The oxygen dynamics in a reactive Ar/O2 high power impulse magnetron sputtering discharge has been studied using a new reactive ionization region model. The aim has been to identify the dominating physical and chemical reactions in the plasma and on the surfaces of the reactor affecting the oxygen plasma chemistry. We explore the temporal evolution of the density of the ground state oxygen molecule O 2 ( X 1 Σg - ) , the singlet metastable oxygen molecules O 2 ( a 1 Δ g ) and O 2 ( b 1 Σ g ) , the oxygen atom in the ground state O(3P), the metastable oxygen atom O(1D), the positive ions O2 + and O+, and the negative ion O-. We furthermore investigate the reaction rates for the gain and loss of these species. The density of atomic oxygen increases significantly as we move from the metal mode to the transition mode, and finally into the compound (poisoned) mode. The main gain rate responsible for the increase is sputtering of atomic oxygen from the oxidized target. Both in the poisoned mode and in the transition mode, sputtering makes up more than 80% of the total gain rate for atomic oxygen. We also investigate the possibility of depositing stoichiometric TiO2 in the transition mode.

A Conformational Change in C-Reactive Protein Enhances Leukocyte Recruitment and Reactive Oxygen Species Generation in Ischemia/Reperfusion Injury.

PubMed

Thiele, Jan R; Zeller, Johannes; Kiefer, Jurij; Braig, David; Kreuzaler, Sheena; Lenz, Yvonne; Potempa, Lawrence A; Grahammer, Florian; Huber, Tobias B; Huber-Lang, M; Bannasch, Holger; Stark, G Björn; Peter, Karlheinz; Eisenhardt, Steffen U

2018-01-01

C-reactive protein circulates as a pentameric protein (pCRP). pCRP is a well-established diagnostic marker as plasma levels rise in response to tissue injury and inflammation. We recently described pro-inflammatory properties of CRP, which are mediated by conformational changes from pCRP to bioactive isoforms expressing pro-inflammatory neo-epitopes [pCRP* and monomeric C-reactive protein (mCRP)]. Here, we investigate the role of CRP isoforms in renal ischemia/reperfusion injury (IRI). Rat kidneys in animals with and without intraperitoneally injected pCRP were subjected to IRI by the time of pCRP exposure and were subsequently analyzed for monocyte infiltration, caspase-3 expression, and tubular damage. Blood urea nitrogen (BUN) was analyzed pre-ischemia and post-reperfusion. CRP effects on leukocyte recruitment were investigated via intravital imaging of rat-striated muscle IRI. Localized conformational CRP changes were analyzed by immunohistochemistry using conformation specific antibodies. 1,6-bis(phosphocholine)-hexane (1,6-bisPC), which stabilizes CRP in its native pentameric form was used to validate CRP effects. Leukocyte activation was assessed by quantification of reactive oxygen species (ROS) induction by CRP isoforms ex vivo and in vitro through electron spin resonance spectroscopy. Signaling pathways were analyzed by disrupting lipid rafts with nystatin and subsequent ROS detection. In order to confirm the translational relevance of our findings, biopsies of microsurgical human free tissue transfers before and after IRI were examined by immunofluorescence for CRP deposition and co-localization of CD68 + leukocytes. The application of pCRP aggravates tissue damage in renal IRI. 1,6-bisPC reverses these effects via inhibition of the conformational change that leads to exposure of pro-inflammatory epitopes in CRP (pCRP* and mCRP). Structurally altered CRP induces leukocyte-endothelial interaction and induces ROS formation in leukocytes, the latter can be abrogated by blocking lipid raft-dependent signaling pathways with Nystatin. Stabilizing pCRP in its native pentameric state abrogates these pro-inflammatory effects. Importantly, these findings are confirmed in human IRI challenged muscle tissue. These results suggest that CRP is a potent modulator of IRI. Stabilizing the native pCRP conformation represents a promising anti-inflammatory therapeutic strategy by attenuation of leukocyte recruitment and ROS formation, the primary pathomechanisms of IRI.

Streptococcus mutans NADH oxidase lies at the intersection of overlapping regulons controlled by oxygen and NAD+ levels.

PubMed

Baker, J L; Derr, A M; Karuppaiah, K; MacGilvray, M E; Kajfasz, J K; Faustoferri, R C; Rivera-Ramos, I; Bitoun, J P; Lemos, J A; Wen, Z T; Quivey, R G

2014-06-01

NADH oxidase (Nox, encoded by nox) is a flavin-containing enzyme used by the oral pathogen Streptococcus mutans to reduce diatomic oxygen to water while oxidizing NADH to NAD(+). The critical nature of Nox is 2-fold: it serves to regenerate NAD(+), a carbon cycle metabolite, and to reduce intracellular oxygen, preventing formation of destructive reactive oxygen species (ROS). As oxygen and NAD(+) have been shown to modulate the activity of the global transcription factors Spx and Rex, respectively, Nox is potentially poised at a critical junction of two stress regulons. In this study, microarray data showed that either addition of oxygen or loss of nox resulted in altered expression of genes involved in energy metabolism and transport and the upregulation of genes encoding ROS-metabolizing enzymes. Loss of nox also resulted in upregulation of several genes encoding transcription factors and signaling molecules, including the redox-sensing regulator gene rex. Characterization of the nox promoter revealed that nox was regulated by oxygen, through SpxA, and by Rex. These data suggest a regulatory loop in which the roles of nox in reduction of oxygen and regeneration of NAD(+) affect the activity levels of Spx and Rex, respectively, and their regulons, which control several genes, including nox, crucial to growth of S. mutans under conditions of oxidative stress. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Suppressive subtractive hybridization approach revealed differential expression of hypersensitive response and reactive oxygen species production genes in tea (Camellia sinensis (L.) O. Kuntze) leaves during Pestalotiopsis thea infection.

PubMed

Senthilkumar, Palanisamy; Thirugnanasambantham, Krishnaraj; Mandal, Abul Kalam Azad

2012-12-01

Tea (Camellia sinensis (L.) O. Kuntze) is an economically important plant cultivated for its leaves. Infection of Pestalotiopsis theae in leaves causes gray blight disease and enormous loss to the tea industry. We used suppressive subtractive hybridization (SSH) technique to unravel the differential gene expression pattern during gray blight disease development in tea. Complementary DNA from P. theae-infected and uninfected leaves of disease tolerant cultivar UPASI-10 was used as tester and driver populations respectively. Subtraction efficiency was confirmed by comparing abundance of β-actin gene. A total of 377 and 720 clones with insert size >250 bp from forward and reverse library respectively were sequenced and analyzed. Basic Local Alignment Search Tool analysis revealed 17 sequences in forward SSH library have high degree of similarity with disease and hypersensitive response related genes and 20 sequences with hypothetical proteins while in reverse SSH library, 23 sequences have high degree of similarity with disease and stress response-related genes and 15 sequences with hypothetical proteins. Functional analysis indicated unknown (61 and 59 %) or hypothetical functions (23 and 18 %) for most of the differentially regulated genes in forward and reverse SSH library, respectively, while others have important role in different cellular activities. Majority of the upregulated genes are related to hypersensitive response and reactive oxygen species production. Based on these expressed sequence tag data, putative role of differentially expressed genes were discussed in relation to disease. We also demonstrated the efficiency of SSH as a tool in enriching gray blight disease related up- and downregulated genes in tea. The present study revealed that many genes related to disease resistance were suppressed during P. theae infection and enhancing these genes by the application of inducers may impart better disease tolerance to the plants.

Reactive oxygen species induced by heat stress during grain filling of rice (Oryza sativa L.) are involved in occurrence of grain chalkiness.

PubMed

Suriyasak, Chetphilin; Harano, Keisuke; Tanamachi, Koichiro; Matsuo, Kazuhiro; Tamada, Aina; Iwaya-Inoue, Mari; Ishibashi, Yushi

2017-09-01

Heat stress during grain filling increases rice grain chalkiness due to increased activity of α-amylase, which hydrolyzes starch. In rice and barley seeds, reactive oxygen species (ROS) produced after imbibition induce α-amylase activity via regulation of gibberellin (GA) and abscisic acid (ABA) levels during seed germination. Here, we examined whether ROS is involved in induction of grain chalkiness by α-amylase in developing rice grains under heat stress. To elucidate the role of ROS in grain chalkiness, we grew post-anthesis rice plants (Oryza sativa L. cv. Koshihikari) under control (25°C) or heat stress (30°C) conditions with or without antioxidant (dithiothreitol) treatment. The developing grains were analyzed for expression of NADPH oxidases, GA biosynthesis genes (OsGA3ox1, OsGA20ox1), ABA catabolism genes (OsABA8'OH1, OsABA8'OH2) and an α-amylase gene (OsAmy3E), endogenous H 2 O 2 content and the grain quality. In grains exposed to heat stress, the expression of NADPH oxidase genes (especially, OsRbohB, OsRbohD, OsRbohF and OsRbohI) and the ROS content increased. Heat stress also increased the expression of OsGA3ox1, OsGA20ox1, OsABA8'OH1, OsABA8'OH2 and OsAmy3E. On the other hand, dithiothreitol treatment reduced the effects of heat stress on the expression of these genes and significantly reduced grain chalkiness induced by heat stress. These results suggest that, similar to cereal seed germination mechanism, ROS produced under heat stress is involved in α-amylase induction in maturating rice grains through GA/ABA metabolism, and consequently caused grain chalkiness. Copyright © 2017 Elsevier GmbH. All rights reserved.

Heterogeneity in c-jun gene expression in normal and malignant cells exposed to either ionizing radiation or hydrogen peroxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Collart, F.R.; Horio, M.; Huberman, E.

1995-05-01

We investigated the role of reactive oxygen intermediates and protein kinase C in the induction of expression of the c-jun gene in human ML-2 leukemic cells and normal human DET-551 fibroblasts by comparing the effects of exposure to either ionizing radiation or H{sub 2}O{sub 2} in the presence or absence of appropriate inhibitors. In these cell types, the radiation-and H{sub 2}O{sub 2}-mediated increase in c-jun mRNA levels could be prevented by pretreatment of the cells with N-acetylcysteine, and antioxidant, or H7, an inhibitor of protein kinase C and protein kinase A, but not by HA1004, a specific inhibitor of proteinmore » kinase A and G. These results suggest a role for protein kinase C and reactive oxygen intermediates in the induction of c-jun gene expression in both normal and tumor cells. We also investigated potential differences in c-jun gene expression induced by radiation or H{sub 2}O{sub 2} in normal and tumor cells by examining steady-state c-jun mRNA levels in a number of human fibroblast, leukemia, melanoma, sarcoma and carcinoma cell types. We observed heterogeneity in the steady-state level of c-jun mRNA in both the untreated normal and tumor cells and in such cells exposed to ionizing radiation or to H{sub 2}O{sub 2}. Exposure to radiation produced a varied response which ranged from little or no induction to an increase in the steady-state level of the c-jun mRNA of more than two orders of magnitude. Exposure to H{sub 2}O{sub 2} gave a pattern similar to that of ionizing radiation. The basis for the differential induction in response to these agents may be attributable to either cell lineage or genetic heterogeneity or a combination of these two parameters. 30 refs., 7 figs., 1 tab.« less

The anthocyanin cyanidin-3-O-β-glucoside, a flavonoid, increases hepatic glutathione synthesis and protects hepatocytes against reactive oxygen species during hyperglycemia: Involvement of a cAMP-PKA-dependent signaling pathway.

PubMed

Zhu, Wei; Jia, Qianju; Wang, Yun; Zhang, Yuhua; Xia, Min

2012-01-15

Enhanced oxidative stress due to high glucose contributes to pathological changes in diabetes-related liver complications. Reducing oxidative stress may alleviate these pathogenic processes. Anthocyanin, a natural antioxidant, has been reported to reduce intracellular reactive oxygen species (ROS) levels but the mechanism of this reduction is not fully understood. The glutathione (GSH) antioxidant system is critical for counteracting oxidative stress-induced intracellular injury. In this study, we evaluated the mechanism of the anthocyanin-mediated regulation of GSH synthesis and reduction in intracellular ROS levels. We observed that treatment of human HepG2 cells with the anthocyanin C3G significantly reduced ROS levels induced by high glucose. C3G incubation increased glutamate-cysteine ligase expression, which in turn mediated the reduction in ROS levels. However, the upregulation of glutamate-cysteine ligase catalytic subunit (Gclc) expression by C3G occurred independent of the Nrf1/2 transcription factors. Notably, the cAMP-response element binding protein (CREB) was identified as the target transcription factor involved in the C3G-mediated upregulation of Gclc expression. C3G increased phosphorylation of CREB through protein kinase A (PKA) activation, which induced a CREB-mediated upregulation of Gclc transcription. In vivo, treatment with C3G increased the GSH synthesis in the liver of diabetic db/db mice through PKA-CREB-dependent induction of Gclc expression. Finally, oxidative stress determined by lipid peroxidation, neutrophil infiltration, and hepatic steatosis was attenuated in C3G-treated db/db mice. Our results demonstrate that the anthocyanin C3G has an effect of activating GSH synthesis through a novel antioxidant defense mechanism against excessive ROS production, contributing to the prevention of hyperglycemia-induced hepatic oxidative damage. Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.

γ-Tocotrienol prevents 5-FU-induced reactive oxygen species production in human oral keratinocytes through the stabilization of 5-FU-induced activation of Nrf2.

PubMed

Takano, Hideyuki; Momota, Yukihiro; Kani, Kouichi; Aota, Keiko; Yamamura, Yoshiko; Yamanoi, Tomoko; Azuma, Masayuki

2015-04-01

Chemotherapy-induced oral mucositis is a common adverse event in patients with oral squamous cell carcinoma, and is initiated through a variety of mechanisms, including the generation of reactive oxygen species (ROS). In this study, we examined the preventive effect of γ-tocotrienol on the 5-FU-induced ROS production in human oral keratinocytes (RT7). We treated RT7 cells with 5-FU and γ-tocotrienol at concentrations of 10 µg/ml and 10 nM, respectively. When cells were treated with 5-FU alone, significant growth inhibition was observed as compared to untreated cells. This inhibition was, in part, due to the ROS gene-rated by 5-FU treatment, because N-acetyl cysteine (NAC), a ROS scavenger, significantly ameliorated the growth of RT7 cells. γ-tocotrienol showed no cytotoxic effect on the growth of RT7 cells. Simultaneous treatment of cells with these agents resulted in the significant recovery of cell growth, owing to the suppression of ROS generation by γ-tocotrienol. Whereas 5-FU stimulated the expression of NF-E2-related factor 2 (Nrf2) protein in the nucleus up to 12 h after treatment of RT7 cells, γ-tocotrienol had no obvious effect on the expression of nuclear Nrf2 protein. Of note, the combined treatment with both agents stabilized the 5-FU-induced nuclear Nrf2 protein expression until 24 h after treatment. In addition, expression of Nrf2-dependent antioxidant genes, such as heme oxygenase-1 (HO-1) and quinone oxidoreductase-1 (NQO-1), was significantly augmented by treatment of cells with both agents. These findings suggest that γ-tocotrienol could prevent 5-FU-induced ROS generation by stabilizing Nrf2 activation, thereby leading to ROS detoxification and cell survival in human oral keratinocytes.

Lithium promotes the production of reactive oxygen species via GSK-3β/TSC2/TOR signaling in the gill of zebrafish (Danio rerio).

PubMed

Liu, Dongwu; Gao, Lili; Zhang, Zhuangzhuang; Tao, Shiyi; Pang, Qiuxiang; Li, Ao; Deng, Hongkuan; Yu, Hairui

2018-03-01

In this study, the mechanism that lithium (Li) promotes the production of reactive oxygen species (ROS) via the glycogen synthase kinase-3β (GSK-3β)/tuberous sclerosis complex 2 (TSC2)/target of rapamycin (TOR) signaling was investigated in the gill of zebrafish (Danio rerio). After the zebrafish were treated by 25 and 50 mg/L Li + , the mRNA expression of GSK-3β and TSC2 was inhibited, but the expression of TOR was induced in the gill of zebrafish. The levels of hydrogen peroxide (H 2 O 2 ), superoxide anion (O 2 ·- ), and hydroxy radical (·OH) as well as the activity of superoxide dismutase (SOD) were increased, while the activities of catalase (CAT), glutathione peroxidase (GSH-PX), and peroxidase (POD) were decreased by 25 and 50 mg/L Li + treatments. In the ZF4 cells, the mRNA expression of GSK-3β and TSC2 was inhibited, but TOR expression was induced by 1, 5, and 10 mmol/L Li + treatments. To further confirm that lithium promoted ROS production via GSK-3β inhibition, GSK-3β RNA was interfered. It was found that the interference of GSK-3β RNA induced the TSC2/TOR signaling. The levels of H 2 O 2 , O 2 ·- , and ·OH were increased, but the activities of CAT, GSH-PX, and POD were decreased by GSK-3β RNA interference. In addition, lithium decreased the mitochondrial membrane potential (MMP) with Rhodamine-123 assay, but increased the levels of ROS by 2',7'-dichlorofluorescein diacetate (DCFH-DA) assay. The present results indicated that lithium promoted the ROS production through the GSK-3β/TSC2/TOR signaling in the gill of zebrafish. Copyright © 2017 Elsevier Ltd. All rights reserved.

A novel biomarker for marine environmental pollution of CAT from Mytilus coruscus.

PubMed

Bao, Miaomiao; Huo, Liping; Wu, Jiong; Ge, Delong; Lv, Zhenming; Chi, Changfeng; Liao, Zhi; Liu, Huihui

2018-02-01

Bivalves use anti-oxidative enzyme systems to defend themselves against excessive reactive oxygen species, which are often catalyzed by environmental pollution. As a key member of anti-oxidative enzyme family, catalase plays a crucial role in scavenging the high level of reactive oxygen species to protect organisms against various oxidative stresses. In this study, a catalase homologue was identified from Mytilus coruscus (named McCAT, KX957929). The open reading frame of McCAT was 1844bp with a 5' untranslated region of 341bp and a 3' untranslated region of 927bp. The deduced amino acid sequence was 512 residues in length with theoretical pI/MW 8.02/57.91kDa. BLASTn and phylogenetic analyses strongly suggested that it was a member of catalase, also known as CAT family for its conserved catalytic site motif and proximal heme-ligand signature motif. Real-time fluorescence quantitative PCR showed that constitutive expression of McCAT was occurred, with increasing order in mantle, adductor, gill, hemocyte, gonad and hepatopancreas. It was observed that bacterial infection and heavy metals stimulation up-regulated McCAT mRNA expression in hepatopancreas with time-dependent manners. The maximum expression appeared at 8h after pathogenic bacteria injecting, with 15-fold in Vibrio parahemolyticus and 60-fold in Aeromonas hydrophila than that of 0h. The highest point of McCAT mRNA appeared at different times for exposure to heavy metals with copper at day 5 (0.1mg/L 30-fold, 0.5mg/L 15-fold, 1.5mg/L 6-fold) and plumbum at day 3 (3.0mg/L 20-fold). The enzymatic activity analysis found that McCAT activity in the gill of M. coruscus was affected by heavy metals concentration. The results suggested that McCAT plays a significant role in antioxidation and the expression of McCAT can be used as a biomarker for detection of marine environmental pollution. Copyright © 2018 Elsevier Ltd. All rights reserved.

γ-tocotrienol prevents 5-FU-induced reactive oxygen species production in human oral keratinocytes through the stabilization of 5-FU-induced activation of Nrf2

PubMed Central

TAKANO, HIDEYUKI; MOMOTA, YUKIHIRO; KANI, KOUICHI; AOTA, KEIKO; YAMAMURA, YOSHIKO; YAMANOI, TOMOKO; AZUMA, MASAYUKI

2015-01-01

Chemotherapy-induced oral mucositis is a common adverse event in patients with oral squamous cell carcinoma, and is initiated through a variety of mechanisms, including the generation of reactive oxygen species (ROS). In this study, we examined the preventive effect of γ-tocotrienol on the 5-FU-induced ROS production in human oral keratinocytes (RT7). We treated RT7 cells with 5-FU and γ-tocotrienol at concentrations of 10 μg/ml and 10 nM, respectively. When cells were treated with 5-FU alone, significant growth inhibition was observed as compared to untreated cells. This inhibition was, in part, due to the ROS generated by 5-FU treatment, because N-acetyl cysteine (NAC), a ROS scavenger, significantly ameliorated the growth of RT7 cells. γ-tocotrienol showed no cytotoxic effect on the growth of RT7 cells. Simultaneous treatment of cells with these agents resulted in the significant recovery of cell growth, owing to the suppression of ROS generation by γ-tocotrienol. Whereas 5-FU stimulated the expression of NF-E2-related factor 2 (Nrf2) protein in the nucleus up to 12 h after treatment of RT7 cells, γ-tocotrienol had no obvious effect on the expression of nuclear Nrf2 protein. Of note, the combined treatment with both agents stabilized the 5-FU-induced nuclear Nrf2 protein expression until 24 h after treatment. In addition, expression of Nrf2-dependent antioxidant genes, such as heme oxygenase-1 (HO-1) and NAD(P)H:quinone oxidoreductase-1 (NQO-1), was significantly augmented by treatment of cells with both agents. These findings suggest that γ-tocotrienol could prevent 5-FU-induced ROS generation by stabilizing Nrf2 activation, thereby leading to ROS detoxification and cell survival in human oral keratinocytes. PMID:25625649

Roles of mitochondrial fragmentation and reactive oxygen species in mitochondrial dysfunction and myocardial insulin resistance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watanabe, Tomoyuki; Saotome, Masao, E-mail: msaotome@hama-med.ac.jp; Nobuhara, Mamoru

Purpose: Evidence suggests an association between aberrant mitochondrial dynamics and cardiac diseases. Because myocardial metabolic deficiency caused by insulin resistance plays a crucial role in heart disease, we investigated the role of dynamin-related protein-1 (DRP1; a mitochondrial fission protein) in the pathogenesis of myocardial insulin resistance. Methods and Results: DRP1-expressing H9c2 myocytes, which had fragmented mitochondria with mitochondrial membrane potential (ΔΨ{sub m}) depolarization, exhibited attenuated insulin signaling and 2-deoxy-D-glucose (2-DG) uptake, indicating insulin resistance. Treatment of the DRP1-expressing myocytes with Mn(III)tetrakis(1-methyl-4-pyridyl)porphyrin pentachloride (TMPyP) significantly improved insulin resistance and mitochondrial dysfunction. When myocytes were exposed to hydrogen peroxide (H{sub 2}O{sub 2}),more » they increased DRP1 expression and mitochondrial fragmentation, resulting in ΔΨ{sub m} depolarization and insulin resistance. When DRP1 was suppressed by siRNA, H{sub 2}O{sub 2}-induced mitochondrial dysfunction and insulin resistance were restored. Our results suggest that a mutual enhancement between DRP1 and reactive oxygen species could induce mitochondrial dysfunction and myocardial insulin resistance. In palmitate-induced insulin-resistant myocytes, neither DRP1-suppression nor TMPyP restored the ΔΨ{sub m} depolarization and impaired 2-DG uptake, however they improved insulin signaling. Conclusions: A mutual enhancement between DRP1 and ROS could promote mitochondrial dysfunction and inhibition of insulin signal transduction. However, other mechanisms, including lipid metabolite-induced mitochondrial dysfunction, may be involved in palmitate-induced insulin resistance. - Highlights: • DRP1 promotes mitochondrial fragmentation and insulin-resistance. • A mutual enhancement between DRP1 and ROS ipromotes insulin-resistance. • Palmitate increases DRP1 expression and induces insulin-resistance. • Inhibition of DRP or ROS failed to improve palmitate-induced insulin-resistance. • Mitochondrial dysfunction by lipid metabolites would induce insulin-resistance.« less

Photo-excitation of carotenoids causes cytotoxicity via singlet oxygen production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoshii, Hiroshi, E-mail: yoshii@nirs.go.jp; Faculty of Medical Sciences, University of Fukui, Eiheiji, Fukui 910-1193; Yoshii, Yukie, E-mail: yukiey@nirs.go.jp

Highlights: Black-Right-Pointing-Pointer Some photo-excited carotenoids have photosensitizing ability. Black-Right-Pointing-Pointer They are able to produce ROS. Black-Right-Pointing-Pointer Photo-excited fucoxanthin can produce singlet oxygen through energy transfer. -- Abstract: Carotenoids, natural pigments widely distributed in algae and plants, have a conjugated double bond system. Their excitation energies are correlated with conjugation length. We hypothesized that carotenoids whose energy states are above the singlet excited state of oxygen (singlet oxygen) would possess photosensitizing properties. Here, we demonstrated that human skin melanoma (A375) cells are damaged through the photo-excitation of several carotenoids (neoxanthin, fucoxanthin and siphonaxanthin). In contrast, photo-excitation of carotenoids that possess energymore » states below that of singlet oxygen, such as {beta}-carotene, lutein, loroxanthin and violaxanthin, did not enhance cell death. Production of reactive oxygen species (ROS) by photo-excited fucoxanthin or neoxanthin was confirmed using a reporter assay for ROS production with HeLa Hyper cells, which express a fluorescent indicator protein for intracellular ROS. Fucoxanthin and neoxanthin also showed high cellular penetration and retention. Electron spin resonance spectra using 2,2,6,6-tetramethil-4-piperidone as a singlet oxygen trapping agent demonstrated that singlet oxygen was produced via energy transfer from photo-excited fucoxanthin to oxygen molecules. These results suggest that carotenoids such as fucoxanthin, which are capable of singlet oxygen production through photo-excitation and show good penetration and retention in target cells, are useful as photosensitizers in photodynamic therapy for skin disease.« less

Increasing dissolved-oxygen disrupts iron homeostasis in production cultures of Escherichia coli.

PubMed

Baez, Antonino; Shiloach, Joseph

2017-01-01

The damaging effect of high oxygen concentration on growth of Escherichia coli is well established. Over-oxygenation increases the intracellular concentration of reactive oxygen species (ROS), causing the destruction of the [4Fe-4S] cluster of dehydratases and limiting the biosynthesis of both branched-chain amino acids and nicotinamide adenine dinucleotide. A key enzyme that reduces the damaging effect of superoxide is superoxide dismutase (SOD). Its transcriptional regulation is controlled by global transcription regulators that respond to changes in oxygen and iron concentrations and pH. Production of biological compounds from E. coli is currently achieved using cultures grown to high cell densities which require oxygen-enriched air supply. It is, therefore, important to study the effect of over-oxygenation on E. coli metabolism and the bacterial protecting mechanism. The effect of over-oxygenation on the superoxide dismutase regulation system was evaluated in cultures grown in a bioreactor by increasing the oxygen concentration from 30 to 300 % air saturation. Following the change in the dissolved oxygen (DO), the expression of sodC, the periplasmic CuZn-containing SOD, and sodA, the cytosolic Mn-containing SOD, was higher in all the tested strains, while the expression of the sodB, the cytosolic Fe-containing SOD, was lower. The down-regulation of the sodB was found to be related to the activation of the small RNA RyhB. It was revealed that iron homeostasis, in particular ferric iron, was involved in the RyhB activation and in sodB regulation but not in sodA. Supplementation of amino acids to the culture medium reduced the intracellular ROS accumulation and reduced the activation of both SodA and SodC following the increase in the oxygen concentration. The study provides evidence that at conditions of over-oxygenation, sodA and sodC are strongly regulated by the amount of ROS, in particular superoxide; and sodB is regulated by iron availability through the small RNA RyhB. In addition, information on the impact of NADH, presence of amino acids and type of iron on SOD regulation, and consequently, on the ROS concentration is provided.

Targeting reactive oxygen species in development and progression of pancreatic cancer

PubMed Central

Durand, Nisha; Storz, Peter

2017-01-01

Introduction Pancreatic ductal adenocarcinoma (PDA) is characterized by expression of oncogenic KRas which drives all aspects of tumorigenesis. Oncogenic KRas induces the formation of reactive oxygen species (ROS) which have been implicated in initiation and progression of PDA. To facilitate tumor promoting levels and to avoid oncogene-induced senescence or cytotoxicity, ROS homeostasis in PDA cells is balanced by additional up-regulation of antioxidant systems. Areas Covered We examine the sources of ROS in PDA, the mechanisms by which ROS homeostasis is maintained, and the biological consequences of ROS in PDA. Additionally, we discuss the potential mechanisms for targeting ROS homoeostasis as a point of therapeutic intervention. An extensive review of the relevant literature as it relates to the topic was conducted using PubMed. Expert Commentary Even though oncogenic mutations in the KRAS gene have been detected in over 95% of human pancreatic adenocarcinoma, targeting its gene product, KRas, has been difficult. The dependency of PDA cells on balancing ROS homeostasis could be an angle for new prevention or treatment strategies. These include use of antioxidants to prevent formation or progression of precancerous lesions, or methods to increase ROS in tumor cells to toxic levels. PMID:27841037

Antimony trichloride induces a loss of cell viability via reactive oxygen species-dependent autophagy in A549 cells.

PubMed

Zhao, Xinyuan; Xing, Fengjun; Cong, Yewen; Zhuang, Yin; Han, Muxi; Wu, Zhiqiang; Yu, Shali; Wei, Haiyan; Wang, Xiaoke; Chen, Gang

2017-12-01

Antimony (Sb) is one of the most prevalent heavy metals and frequently leads to biological toxicity. Although autophagy is believed to be involved in metal-associated cytotoxicity, there is no evidence of its involvement following exposure. Moreover, the underlying mechanism of autophagy remains unclear. In this study, treatment with antimony trichloride caused autophagy in a dose- and time-dependent manner in A549 cells but did not affect the level of Atg5 or Atg7 mRNA expression. Furthermore, Sb enhanced autophagic flux while upregulating p62 gene and protein levels. The classic mechanistic target of rapamycin (mTOR) pathway is not involved in Sb-induced autophagy. However, Sb-induced autophagy and the upregulation of p62 were inhibited by treatment with the antioxidant N-acetylcysteine (NAC). Subsequent analyses demonstrated that the inhibition of autophagy protected A549 cells from a loss of cell viability, while the activation of autophagy by rapamycin had the opposite effect. These data suggest that reactive oxygen species-dependent autophagy mediates Sb-stimulated cell viability loss in A549 cells. Copyright © 2017 Elsevier Ltd. All rights reserved.

Olive Oil Phenolics Prevent Oxysterol‐Induced Proinflammatory Cytokine Secretion and Reactive Oxygen Species Production in Human Peripheral Blood Mononuclear Cells, Through Modulation of p38 and JNK Pathways

PubMed Central

Deiana, Monica; Spencer, Jeremy P. E.; Corona, Giulia

2017-01-01

Scope The aim of the present study was to investigate the ability of extra virgin olive oil (EVOO) polyphenols to counteract the proinflammatory effects induced by dietary and endogenous oxysterols in ex vivo immune cells. Methods and results Peripheral blood mononuclear cells (PBMCs), separated from the whole blood of healthy donors, were utilized and were stimulated with an oxysterols mixture, in the presence of physiologically relevant concentrations of the EVOO polyphenols, hydroxytyrosol, tyrosol, and homovanillic alcohol. Oxysterols significantly increased the production of proinflammatory cytokines, interleukin‐1β, regulated on activation, normal T‐cell expressed and secreted and macrophage migration inhibitory factor in ex vivo cultured PBMCs. Increased levels of reactive oxygen species (ROS) were also detected along with increased phosphorylation of the p38 and JNK. All phenolic compounds significantly reduced cytokine secretion induced by the oxysterols and inhibited ROS production and mitogen activated protein kinase phosphorylation. Conclusions These results suggest that extra virgin olive oil polyphenols modulate the immune response induced by dietary and endogenous cholesterol oxidation products in human immune cells and may hold benefit in controlling chronic immune and/or inflammatory processes. PMID:28815947

Synergistic antitumor activity of withaferin A combined with oxaliplatin triggers reactive oxygen species-mediated inactivation of the PI3K/AKT pathway in human pancreatic cancer cells.

PubMed

Li, Xu; Zhu, Feng; Jiang, Jianxin; Sun, Chengyi; Wang, Xin; Shen, Ming; Tian, Rui; Shi, Chengjian; Xu, Meng; Peng, Feng; Guo, Xingjun; Wang, Min; Qin, Renyi

2015-02-01

Application of oxaliplatin for the treatment of pancreatic cancer (PC) is restricted owing to its toxic side effects and drug resistance. We investigated how withaferin A (WA), a bioactive component isolated from the medicinal plant Withania somnifera, acts synergistically with oxaliplatin on human PC in vitro and in vivo. We found that WA enhanced oxaliplatin-induced growth suppression and apoptosis in PC cells dramatically through a mechanism involving mitochondrial dysfunction and inactivation of the PI3K/AKT pathway. Combination treatment resulted in significant accumulation of intracellular reactive oxygen species (ROS). Pretreatment of cells with the ROS scavenger N-acetylcysteine completely blocked the apoptosis induced by combination treatment, and recovered expression of AKT inactivation, which revealed the important role of ROS in apoptosis and AKT regulation. In vivo, combination therapy showed the strongest anti-tumor effects compared with single agents, without obvious additional toxicity. These results support the notion that combination treatment with oxaliplatin and WA could facilitate development of an effective strategy for PC treatment. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Long-chain bases, phosphatidic acid, MAPKs, and reactive oxygen species as nodal signal transducers in stress responses in Arabidopsis

PubMed Central

Saucedo-García, Mariana; Gavilanes-Ruíz, Marina; Arce-Cervantes, Oscar

2015-01-01

Due to their sessile condition, plants have developed sensitive, fast, and effective ways to contend with environmental changes. These mechanisms operate as informational wires conforming extensive and intricate networks that are connected in several points. The responses are designed as pathways orchestrated by molecules that are transducers of protein and non-protein nature. Their chemical nature imposes selective features such as specificity, formation rate, and generation site to the informational routes. Enzymes such as mitogen-activated protein kinases and non-protein, smaller molecules, such as long-chain bases, phosphatidic acid, and reactive oxygen species are recurrent transducers in the pleiotropic responses to biotic and abiotic stresses in plants. In this review, we considered these four components as nodal points of converging signaling pathways that start from very diverse stimuli and evoke very different responses. These pleiotropic effects may be explained by the potentiality that every one of these four mediators can be expressed from different sources, cellular location, temporality, or magnitude. Here, we review recent advances in our understanding of the interplay of these four specific signaling components in Arabidopsis cells, with an emphasis on drought, cold and pathogen stresses. PMID:25763001

CCL11 enhances excitotoxic neuronal death by producing reactive oxygen species in microglia.

PubMed

Parajuli, Bijay; Horiuchi, Hiroshi; Mizuno, Tetsuya; Takeuchi, Hideyuki; Suzumura, Akio

2015-12-01

The chemokine CCL11 (also known as eotaxin-1) is a potent eosinophil chemoattractant that mediates allergic diseases such as asthma, atopic dermatitis, and inflammatory bowel diseases. Previous studies demonstrated that concentrations of CCL11 are elevated in the sera and cerebrospinal fluids (CSF) of patients with neuroinflammatory disorders, including multiple sclerosis. Moreover, the levels of CCL11 in plasma and CSF increase with age, and CCL11 suppresses adult neurogenesis in the central nervous system (CNS), resulting in memory impairment. However, the precise source and function of CCL11 in the CNS are not fully understood. In this study, we found that activated astrocytes release CCL11, whereas microglia predominantly express the CCL11 receptor. CCL11 significantly promoted the migration of microglia, and induced microglial production of reactive oxygen species by upregulating nicotinamide adenine dinucleotide phosphate-oxidase 1 (NOX1), thereby promoting excitotoxic neuronal death. These effects were reversed by inhibition of NOX1. Our findings suggest that CCL11 released from activated astrocytes triggers oxidative stress via microglial NOX1 activation and potentiates glutamate-mediated neurotoxicity, which may be involved in the pathogenesis of various neurological disorders. © 2015 Wiley Periodicals, Inc.

Reactive oxygen species are required for zoledronic acid-induced apoptosis in osteoclast precursors and mature osteoclast-like cells

PubMed Central

Tai, Ta-Wei; Chen, Ching-Yu; Su, Fong-Chin; Tu, Yuan-Kun; Tsai, Tsung-Ting; Lin, Chiou-Feng; Jou, I.-Ming

2017-01-01

Inhibiting osteoclasts and osteoclast precursors to reduce bone resorption is an important strategy to treat osteoclast-related diseases, such as osteoporosis, inflammatory bone loss, and malignant bone metastasis. However, the mechanism by which apoptosis is induced in the osteoclasts and their precursors are not completely understood. Here, we used nitrogen-containing bisphosphonate zoledronic acid (ZA) to induce cell apoptosis in human and murine osteoclast precursors and mature osteoclast-like cells. Caspase-3-mediated cell apoptosis occurred following the ZA (100 μM) treatment. Reactive oxygen species (ROS) were also generated in a time-dependent manner. Following knock-down of the p47phox expression, which is required for ROS activation, or co-treatment with the ROS inhibitor, N-acetyl-L-cysteine, ZA-induced apoptosis was significantly suppressed in both osteoclast precursors and mature osteoclast-like cells. The ROS-activated mitogen-activated protein kinases pathways did not trigger cell apoptosis. However, a ROS-regulated Mcl-1 decrease simultaneously with glycogen synthase kinase (GSK)-3β promoted cell apoptosis. These findings show that ZA induces apoptosis in osteoclast precursors and mature osteoclast-like cells by triggering ROS- and GSK-3β-mediated Mcl-1 down-regulation. PMID:28281643

Pigment epithelium-derived factor stimulates skeletal muscle glycolytic activity through NADPH oxidase-dependent reactive oxygen species production.

PubMed

Carnagarin, Revathy; Carlessi, Rodrigo; Newsholme, Philip; Dharmarajan, Arun M; Dass, Crispin R

2016-09-01

Pigment epithelium-derived factor is a multifunctional serpin implicated in insulin resistance in metabolic disorders. Recent evidence suggests that exposure of peripheral tissues such as skeletal muscle to PEDF has profound metabolic consequences with predisposition towards chronic conditions such as obesity, type 2 diabetes, metabolic syndrome and polycystic ovarian syndrome. Chronic inflammation shifts muscle metabolism towards increased glycolysis and decreased oxidative metabolism. In the present study, we demonstrate a novel effect of PEDF on cellular metabolism in mouse cell line (C2C12) and human primary skeletal muscle cells. PEDF addition to skeletal muscle cells induced enhanced phospholipase A2 activity. This was accompanied with increased production of reactive oxygen species in a nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-dependent manner that triggered a shift towards a more glycolytic phenotype. Extracellular flux analysis and glucose consumption assays demonstrated that PEDF treatment resulted in enhanced glycolysis but did not change mitochondrial respiration. Our results demonstrate that skeletal muscle cells express a PEDF-inducible oxidant generating system that enhances glycolysis but is sensitive to antioxidants and NADPH oxidase inhibition. Copyright © 2016 Elsevier Ltd. All rights reserved.

Phenylpropanoids isolated from Piper sarmentosum Roxb. induce apoptosis in breast cancer cells through reactive oxygen species and mitochondrial-dependent pathways.

PubMed

Hematpoor, Arshia; Paydar, Mohammadjavad; Liew, Sook Yee; Sivasothy, Yasodha; Mohebali, Nooshin; Looi, Chung Yeng; Wong, Won Fen; Azirun, Mohd Sofian; Awang, Khalijah

2018-01-05

The aim of the present study is to isolate bioactive compounds from the roots of Piper sarmentosum and examine the mechanism of action using human breast cancer cell line (MDA-MB-231). Bioassay guided-fractionation of methanolic extract led to the isolation of asaricin (1) and isoasarone (2). Asaricin (1) and isoasarone (2) had significant cytotoxicity towards MDA-MB-231. MCF-10A (human normal breast epithelial cells) cells are less sensitive than MDA-MB-231, but they respond to the treatment with the same unit of measurement. Both compounds increase reactive oxygen species (ROS), decrease mitochondrial membrane potential (MMP) and enhance cytochrome c release in treated MDA-MB-231 cells. Isoasarone (2) markedly elevated caspase -8 and -3/7 activities and caused a decline in nuclear NF-κB translocation, suggesting extrinsic, death receptor-linked apoptosis pathway. Quantitative PCR results of MDA-MB-231 treated with asaricin (1) and isoasarone (2) showed altered expression of Bcl-2: Bax level. The inhibitory potency of these isolates may support the therapeutic uses of these compounds in breast cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

Proteome analysis of Arabidopsis seedlings exposed to bacterial volatiles.

PubMed

Kwon, Young Sang; Ryu, Choong-Min; Lee, Soohyun; Park, Hyo Bee; Han, Ki Soo; Lee, Jung Han; Lee, Kyunghee; Chung, Woo Sik; Jeong, Mi-Jeong; Kim, Hee Kyu; Bae, Dong-Won

2010-11-01

Plant root-associated bacteria (rhizobacteria) elicit plant basal immunity referred to as induced systemic resistance (ISR) against multiple pathogens. Among multi-bacterial determinants involving such ISR, the induction of ISR and promotion of growth by bacterial volatile compounds was previously reported. To exploit global de novo expression of plant proteins by bacterial volatiles, proteomic analysis was performed after exposure of Arabidopsis plants to the rhizobacterium Bacillus subtilis GB03. Ethylene biosynthesis enzymes were significantly up-regulated. Analysis by quantitative reverse transcriptase polymerase chain reaction confirmed that ethylene biosynthesis-related genes SAM-2, ACS4, ACS12, and ACO2 as well as ethylene response genes, ERF1, GST2, and CHIB were up-regulated by the exposure to bacterial volatiles. More interestingly, the emission of bacterial volatiles significantly up-regulated both key defense mechanisms mediated by jasmonic acid and salicylic acid signaling pathways. In addition, high accumulation of antioxidant proteins also provided evidence of decreased sensitivity to reactive oxygen species during the elicitation of ISR by bacterial volatiles. The present results suggest that the proteomic analysis of plant defense responses in bacterial volatile-mediated ISR can reveal the mechanisms of plant basal defenses orchestrated by endogenous ethylene production pathways and the generation of reactive oxygen species.

Plant Survival in a Changing Environment: The Role of Nitric Oxide in Plant Responses to Abiotic Stress

PubMed Central

Simontacchi, Marcela; Galatro, Andrea; Ramos-Artuso, Facundo; Santa-María, Guillermo E.

2015-01-01

Nitric oxide in plants may originate endogenously or come from surrounding atmosphere and soil. Interestingly, this gaseous free radical is far from having a constant level and varies greatly among tissues depending on a given plant’s ontogeny and environmental fluctuations. Proper plant growth, vegetative development, and reproduction require the integration of plant hormonal activity with the antioxidant network, as well as the maintenance of concentration of reactive oxygen and nitrogen species within a narrow range. Plants are frequently faced with abiotic stress conditions such as low nutrient availability, salinity, drought, high ultraviolet (UV) radiation and extreme temperatures, which can influence developmental processes and lead to growth restriction making adaptive responses the plant’s priority. The ability of plants to respond and survive under environmental-stress conditions involves sensing and signaling events where nitric oxide becomes a critical component mediating hormonal actions, interacting with reactive oxygen species, and modulating gene expression and protein activity. This review focuses on the current knowledge of the role of nitric oxide in adaptive plant responses to some specific abiotic stress conditions, particularly low mineral nutrient supply, drought, salinity and high UV-B radiation. PMID:26617619

Sublethal concentrations of salicylic acid decrease the formation of reactive oxygen species but maintain an increased nitric oxide production in the root apex of the ethylene-insensitive Never ripe tomato mutants

PubMed Central

Poór, Péter; Gémes, Katalin

2011-01-01

The pattern of salicylic acid (SA)-induced production of reactive oxygen species (ROS) and nitric oxide (NO) were different in the apex of adventitious roots in wild-type and in the ethylene-insensitive Never ripe (Nr) mutants of tomato (Solanum lycopersicum L. cv Ailsa Craig). ROS were upregulated, while NO remained at the control level in apical root tissues of wildtype plants exposed to sublethal concentrations of SA. In contrast, Nr plants expressing a defective ethylene receptor displayed a reduced level of ROS and a higher NO content in the apical root cells. In wild-type plants NO production seems to be ROS(H2O2)-dependent at cell death-inducing concentrations of SA, indicating that ROS and NO may interact to trigger oxidative cell death. In the absence of significant ROS accumulation, the increased NO production caused moderate reduction in cell viability in root apex of Nr plants exposed to 10−3 M SA. This suggests that a functional ethylene signaling pathway is necessary for the control of ROS and NO production induced by SA. PMID:21847015

C-phycocyanin protects against low fertility by inhibiting reactive oxygen species in aging mice

PubMed Central

Li, Yan-Jiao; Han, Zhe; Ge, Lei; Zhou, Cheng-Jie; Zhao, Yue-Fang; Wang, Dong-Hui; Ren, Jing; Niu, Xin-Xin; Liang, Cheng-Guang

2016-01-01

Women over 35 have higher rates of infertility, largely due to deterioration of oocyte quality characterized by fragmentation, abnormal meiotic spindle-chromosome complexes, and oxidative stress. C-phycocyanin (PC) is a biliprotein enriched in Spirulina platensis that is known to possess antioxidant, anti-inflammatory, and radical-scavenging properties. D-galactose-induced aging acceleration in mice has been extensively used to study aging mechanisms and for pharmaceutical screening. In this study, adult female B6D2F/1 mice injected with D-galactose were used as a model to test the age-reversing effects of PC on degenerated reproductive ability. Our results show that PC can prevent oocyte fragmentation and aneuploidy by maintaining cytoskeletal integrity. Moreover, PC can reverse the expression of antioxidant genes, increase superoxide dismutase (SOD) activity and decrease methane dicarboxylic aldehyde (MDA) content, and normalize mitochondria distribution. PC exerts its benefit by inhibiting reactive oxygen species (ROS) production, which decreases apoptosis. Finally, we observe a significant increase in litter size after PC administration to D-galactose-induced aging mice. Our study demonstrates for the first time that D-galactose-induced impaired female reproductive capability can be partially rescued by the antioxidant effects of PC. PMID:27008700

Ciclopirox induces autophagy through reactive oxygen species-mediated activation of JNK signaling pathway

PubMed Central

Zhou, Hongyu; Shen, Tao; Shang, Chaowei; Luo, Yan; Liu, Lei; Yan, Juming; Li, Yan; Huang, Shile

2014-01-01

Ciclopirox olamine (CPX), a fungicide, has been demonstrated as a potential anticancer agent. However, the underlying anticancer mechanism is not well understood. Here, we found that CPX induced autophagy in human rhabdomyosarcoma (Rh30 and RD) cells. It appeared that CPX-induced autophagy was attributed to induction of reactive oxygen species (ROS), as N-acetyl-L-cysteine (NAC), a ROS scavenger and antioxidant, prevented this process. Furthermore, we observed that CPX induced activation of mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK) and p38 MAPK, which was also blocked by NAC. However, only inhibition of JNK (with SP600125) or expression of dominant negative c-Jun partially prevented CPX-induced autophagy, indicating that ROS-mediated activation of JNK signaling pathway contributed to CPX-induced autophagy. Of interest, inhibition of autophagy by chloroquine (CQ) enhanced CPX-induced cell death, indicating that CPX-induced autophagy plays a pro-survival role in human rhabdomyosarcoma cells. Our finding suggests that the combination with autophagy inhibitors may be a novel strategy in potentiating the anticancer activity of CPX for treatment of rhabdomyosarcoma. PMID:25294812

Natriuretic peptide receptor A inhibition suppresses gastric cancer development through reactive oxygen species-mediated G2/M cell cycle arrest and cell death.

PubMed

Li, Zheng; Wang, Ji-Wei; Wang, Wei-Zhi; Zhi, Xiao-Fei; Zhang, Qun; Li, Bo-Wen; Wang, Lin-Jun; Xie, Kun-Ling; Tao, Jin-Qiu; Tang, Jie; Wei, Song; Zhu, Yi; Xu, Hao; Zhang, Dian-Cai; Yang, Li; Xu, Ze-Kuan

2016-10-01

Natriuretic peptide receptor A (NPRA), the major receptor for atrial natriuretic peptide (ANP), has been implicated in tumorigenesis; however, the role of ANP-NPRA signaling in the development of gastric cancer remains unclear. Immunohistochemical analyses indicated that NPRA expression was positively associated with gastric tumor size and cancer stage. NPRA inhibition by shRNA induced G2/M cell cycle arrest, cell death, and autophagy in gastric cancer cells, due to accumulation of reactive oxygen species (ROS). Either genetic or pharmacologic inhibition of autophagy led to caspase-dependent cell death. Therefore, autophagy induced by NPRA silencing may represent a cytoprotective mechanism. ROS accumulation activated c-Jun N-terminal kinase (JNK) and AMP-activated protein kinase (AMPK). ROS-mediated activation of JNK inhibited cell proliferation by disturbing cell cycle and decreased cell viability. In addition, AMPK activation promoted autophagy in NPRA-downregulated cancer cells. Overall, our results indicate that the inhibition of NPRA suppresses gastric cancer development and targeting NPRA may represent a promising strategy for the treatment of gastric cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

Carcinogenesis and Reactive Oxygen Species Signaling: Interaction of the NADPH Oxidase NOX1-5 and Superoxide Dismutase 1-3 Signal Transduction Pathways.

PubMed

Parascandolo, Alessia; Laukkanen, Mikko O

2018-04-05

Reduction/oxidation (redox) balance could be defined as an even distribution of reduction and oxidation complementary processes and their reaction end products. There is a consensus that aberrant levels of reactive oxygen species (ROS), commonly observed in cancer, stimulate primary cell immortalization and progression of carcinogenesis. However, the mechanism how different ROS regulate redox balance is not completely understood. Recent Advances: In the current review, we have summarized the main signaling cascades inducing NADPH oxidase NOX1-5 and superoxide dismutase (SOD) 1-3 expression and their connection to cell proliferation, immortalization, transformation, and CD34 + cell differentiation in thyroid, colon, lung, breast, and hematological cancers. Interestingly, many of the signaling pathways activating redox enzymes or mediating the effect of ROS are common, such as pathways initiated from G protein-coupled receptors and tyrosine kinase receptors involving protein kinase A, phospholipase C, calcium, and small GTPase signaling molecules. The clarification of interaction of signal transduction pathways could explain how cells regulate redox balance and may even provide means to inhibit the accumulation of harmful levels of ROS in human pathologies. Antioxid. Redox Signal. 00, 000-000.

Ginger Oleoresin Alleviated γ-Ray Irradiation-Induced Reactive Oxygen Species via the Nrf2 Protective Response in Human Mesenchymal Stem Cells

PubMed Central

Ji, Kaihua; Li, Qing; Shi, Yang; Xu, Chang; Wang, Yan; Du, Liqing

2017-01-01

Unplanned exposure to radiation can cause side effects on high-risk individuals; meanwhile, radiotherapies can also cause injury on normal cells and tissues surrounding the tumor. Besides the direct radiation damage, most of the ionizing radiation- (IR-) induced injuries were caused by generation of reactive oxygen species (ROS). Human mesenchymal stem cells (hMSCs), which possess self-renew and multilineage differentiation capabilities, are a critical population of cells to participate in the regeneration of IR-damaged tissues. Therefore, it is imperative to search effective radioprotectors for hMSCs. This study was to demonstrate whether natural source ginger oleoresin would mitigate IR-induced injuries in human mesenchymal stem cells (hMSCs). We demonstrated that ginger oleoresin could significantly reduce IR-induced cytotoxicity, ROS generation, and DNA strand breaks. In addition, the ROS-scavenging mechanism of ginger oleoresin was also investigated. The results showed that ginger oleoresin could induce the translocation of Nrf2 to cell nucleus and activate the expression of cytoprotective genes encoding for HO-1 and NQO-1. It suggests that ginger oleoresin has a potential role of being an effective antioxidant and radioprotective agent. PMID:29181121

REACTIVE OXYGEN SPECIES IN WHOLE BLOOD, BLOOD PLASMA AND BREAST MILK: VALIDATION OF A POTENTIAL MARKER OF EXPOSURE AND EFFECT

EPA Science Inventory

Reactive oxygen species (ROS) are recognized to contribute to the pathobiology of many diseases. We have applied a simple chemiluminescent (CL) probe to detect ROS in various biological fluids (plasma, whole blood, urine and breast milk) in an environmental arsenic drinking wate...

Herbivore derived fatty acid-amides elicit reactive oxygen species burst in plants

USDA-ARS?s Scientific Manuscript database

The formation of a reactive oxygen species (ROS) burst is a central response of plants to many forms of stress including pathogen attack, several abiotic stresses, damage and insect infestation. These ROS act as a direct defense as well as signaling and regulatory molecules. Perception of microbe or...

Formation and Detoxification of Reactive Oxygen Species

ERIC Educational Resources Information Center

Kuciel, Radoslawa; Mazurkiewicz, Aleksandra

2004-01-01

A model of reactive oxygen species metabolism is proposed as a laboratory exercise for students. The superoxide ion in this model is generated during the reaction of oxidation of xanthine, catalyzed by xanthine oxidase. The effect of catalase, superoxide dismutase, and allopurinol on superoxide ion generation and removal in this system is also…

Size-dependent cytotoxicity of yttrium oxide nanoparticles on primary osteoblasts in vitro

NASA Astrophysics Data System (ADS)

Zhou, Guoqiang; Li, Yunfei; Ma, Yanyan; Liu, Zhu; Cao, Lili; Wang, Da; Liu, Sudan; Xu, Wenshi; Wang, Wenying

2016-05-01

Yttrium oxide nanoparticles are an excellent host material for the rare earth metals and have high luminescence efficiency providing a potential application in photodynamic therapy and biological imaging. In this study, the effects of yttrium oxide nanoparticles with four different sizes were investigated using primary osteoblasts in vitro. The results demonstrated that the cytotoxicity generated by yttrium oxide nanoparticles depended on the particle size, and smaller particles possessed higher toxicological effects. For the purpose to elucidate the relationship between reactive oxygen species generation and cell damage, cytomembrane integrity, intracellular reactive oxygen species level, mitochondrial membrane potential, cell apoptosis rate, and activity of caspase-3 in cells were then measured. Increased reactive oxygen species level was also observed in a size-dependent way. Thus, our data demonstrated that exposure to yttrium oxide nanoparticles resulted in a size-dependent cytotoxicity in cultured primary osteoblasts, and reactive oxygen species generation should be one possible damage pathway for the toxicological effects produced by yttrium oxide particles. The results may provide useful information for more rational applications of yttrium oxide nanoparticles in the future.

Reactive Pendant Mn═O in a Synthetic Structural Model of a Proposed S4 State in the Photosynthetic Oxygen Evolving Complex.

PubMed

Vaddypally, Shivaiah; Kondaveeti, Sandeep K; Karki, Santosh; Van Vliet, Megan M; Levis, Robert J; Zdilla, Michael J

2017-04-05

The molecular mechanism of the Oxygen Evolving Center of photosystem II has been under debate for decades. One frequently cited proposal is the nucleophilic attack by water hydroxide on a pendant Mn═O moiety, though no chemical example of this reactivity at a manganese cubane cluster has been reported. We describe here the preparation, characterization, and a reactivity study of a synthetic manganese cubane cluster with a pendant manganese-oxo moiety. Reaction of this cluster with alkenes results in oxygen and hydrogen atom transfer reactions to form alcohol- and ketone-based oxygen-containing products. Nitrene transfer from core imides is negligible. The inorganic product is a cluster identical to the precursor, but with the pendant Mn═O moiety replaced by a hydrogen abstracted from the organic substrate, and is isolated in quantitative yield. 18 O and 2 H isotopic labeling studies confirm the transfer of atoms between the cluster and the organic substrate. The results suggest that the core cubane structure of this model compound remains intact, and that the pendant Mn═O moiety is preferentially reactive.

Melt containment member

DOEpatents

Rieken, Joel R.; Heidloff, Andrew J.

2014-09-09

A tubular melt containment member for transient containment of molten metals and alloys, especially reactive metals and alloys, includes a melt-contacting layer or region that comprises an oxygen-deficient rare earth oxide material that is less reactive as compared to the counterpart stoichiometric rare earth oxide. The oxygen-deficient (sub-stoichiometric) rare earth oxide can comprise oxygen-deficient yttria represented by Y.sub.2O.sub.3-x wherein x is from 0.01 to 0.1. Use of the oxygen-deficient rare earth oxide as the melt-contacting layer or region material reduces reaction with the melt for a given melt temperature and melt contact time.

Effects of cyanobacterial toxins and cyanobacterial cell-free crude extract on germination of alfalfa (Medicago sativa) and induction of oxidative stress.

PubMed

Pflugmacher, Stephan; Jung, Katharina; Lundvall, Linn; Neumann, Stefanie; Peuthert, Anja

2006-09-01

Cyanobacterial toxins have adverse effects on both terrestrial and aquatic plants. Microcystins are cyclic heptapeptides and an important group of cyanotoxins. When lake water contaminated with cyanobacterial blooms is used for spray irrigation, these toxins can come in contact with agricultural plants. During the exposure to these toxins, reactive oxygen species can form. These reactive oxygen species have a strong reactivity and are able to interact with other cellular compounds (lipids, protein, and DNA). Plants have antioxidative systems that will limit the negative effects caused by reactive oxygen species. These systems consist of enzymes, such as superoxide dismutase, catalase, and ascorbate peroxidase, and nonenzymatic substances, such as reduced glutathione or vitamins. The aim of the present study was to investigate the effects of cyanobacterial toxins (microcystins and anatoxin-a) and cyanobacterial cell-free crude extract on alfalfa (Medicago sativa) seedlings. Inhibition of germination and root growth was observed with toxin concentrations of 5.0 microg/L. Also, oxidative damage, such as lipid peroxidation, was detected after the exposure of alfalfa seedlings to the toxin. Reactive oxygen detoxifying enzymes were elevated, showing a marked response in alfalfa to oxidative stress caused by the exposure to cyanobacterial metabolites that might influence the growth and development of these plants negatively.

Mitochondria-targeted antioxidant MitoQ ameliorates experimental mouse colitis by suppressing NLRP3 inflammasome-mediated inflammatory cytokines.

PubMed

Dashdorj, Amarjargal; Jyothi, K R; Lim, Sangbin; Jo, Ara; Nguyen, Minh Nam; Ha, Joohun; Yoon, Kyung-Sik; Kim, Hyo Jong; Park, Jae-Hoon; Murphy, Michael P; Kim, Sung Soo

2013-08-06

MitoQ is a mitochondria-targeted derivative of the antioxidant ubiquinone, with antioxidant and anti-apoptotic functions. Reactive oxygen species are involved in many inflammatory diseases including inflammatory bowel disease. In this study, we assessed the therapeutic effects of MitoQ in a mouse model of experimental colitis and investigated the possible mechanisms underlying its effects on intestinal inflammation. Reactive oxygen species levels and mitochondrial function were measured in blood mononuclear cells of patients with inflammatory bowel disease. The effects of MitoQ were evaluated in a dextran sulfate sodium-induced colitis mouse model. Clinical and pathological markers of disease severity and oxidative injury, and levels of inflammatory cytokines in mouse colonic tissue were measured. The effect of MitoQ on inflammatory cytokines released in the human macrophage-like cell line THP-1 was also analyzed. Cellular and mitochondrial reactive oxygen species levels in mononuclear cells were significantly higher in patients with inflammatory bowel disease (P <0.003, cellular reactive oxygen species; P <0.001, mitochondrial reactive oxygen species). MitoQ significantly ameliorated colitis in the dextran sulfate sodium-induced mouse model in vivo, reduced the increased oxidative stress response (malondialdehyde and 3-nitrotyrosine formation), and suppressed mitochondrial and histopathological injury by decreasing levels of inflammatory cytokines IL-1 beta and IL-18 (P <0.001 and P <0.01 respectively). By decreasing mitochondrial reactive oxygen species, MitoQ also suppressed activation of the NLRP3 inflammasome that was responsible for maturation of IL-1 beta and IL-18. In vitro studies demonstrated that MitoQ decreases IL-1 beta and IL-18 production in human THP-1 cells. Taken together, our results suggest that MitoQ may have potential as a novel therapeutic agent for the treatment of acute phases of inflammatory bowel disease.

Mitochondria-targeted antioxidant MitoQ ameliorates experimental mouse colitis by suppressing NLRP3 inflammasome-mediated inflammatory cytokines

PubMed Central

2013-01-01

Background MitoQ is a mitochondria-targeted derivative of the antioxidant ubiquinone, with antioxidant and anti-apoptotic functions. Reactive oxygen species are involved in many inflammatory diseases including inflammatory bowel disease. In this study, we assessed the therapeutic effects of MitoQ in a mouse model of experimental colitis and investigated the possible mechanisms underlying its effects on intestinal inflammation. Methods Reactive oxygen species levels and mitochondrial function were measured in blood mononuclear cells of patients with inflammatory bowel disease. The effects of MitoQ were evaluated in a dextran sulfate sodium-induced colitis mouse model. Clinical and pathological markers of disease severity and oxidative injury, and levels of inflammatory cytokines in mouse colonic tissue were measured. The effect of MitoQ on inflammatory cytokines released in the human macrophage-like cell line THP-1 was also analyzed. Results Cellular and mitochondrial reactive oxygen species levels in mononuclear cells were significantly higher in patients with inflammatory bowel disease (P <0.003, cellular reactive oxygen species; P <0.001, mitochondrial reactive oxygen species). MitoQ significantly ameliorated colitis in the dextran sulfate sodium-induced mouse model in vivo, reduced the increased oxidative stress response (malondialdehyde and 3-nitrotyrosine formation), and suppressed mitochondrial and histopathological injury by decreasing levels of inflammatory cytokines IL-1 beta and IL-18 (P <0.001 and P <0.01 respectively). By decreasing mitochondrial reactive oxygen species, MitoQ also suppressed activation of the NLRP3 inflammasome that was responsible for maturation of IL-1 beta and IL-18. In vitro studies demonstrated that MitoQ decreases IL-1 beta and IL-18 production in human THP-1 cells. Conclusion Taken together, our results suggest that MitoQ may have potential as a novel therapeutic agent for the treatment of acute phases of inflammatory bowel disease. PMID:23915129